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Cachafeiro L, Heiss-Blanquet S, Hudebine D. An experimental and modeling approach to describe the deactivation of cellulases at the air-liquid interface. Biotechnol Bioeng 2024. [PMID: 38501733 DOI: 10.1002/bit.28698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 02/15/2024] [Accepted: 03/02/2024] [Indexed: 03/20/2024]
Abstract
Understanding the reaction mechanisms involved in the enzymatic hydrolysis of cellulose is important because it is kinetically the most limiting step of the bioethanol production process. The present work focuses on the enzymatic deactivation at the air-liquid interface, which is one of the aspects contributing to this global deactivation. This phenomenon has already been experimentally proven, but this is the first time that a model has been proposed to describe it. Experiments were performed by incubating Celluclast cocktail solutions on an orbital stirring system at different enzyme concentrations and different surface-to-volume ratios. A 5-day follow-up was carried out by measuring the global FPase activity of cellulases for each condition tested. The activity loss was proven to depend on both the air-liquid surface area and the enzyme concentration. Both observations suggest that the loss of activity takes place at the air-liquid surface, the total amount of enzymes varying with volume or enzyme concentration. Furthermore, tests performed using five individual enzymes purified from a Trichoderma reesei cocktail showed that the only cellulase that is deactivated at the air-liquid interface is cellobiohydrolase II. From the experimental data collected by varying the initial enzyme concentration and the ratio surface to volume, it was possible to develop, for the first time, a model that describes the loss of activity at the air-liquid interface for this configuration.
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2
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Hill L, Cassidy L, Dixon L, Fitzsimons D, Thylen I, Jaarsma T. An insight into healthcare professionals' perspectives on discussing implantable cardioverter defibrillator deactivation. Eur J Cardiovasc Nurs 2024:zvae032. [PMID: 38445771 DOI: 10.1093/eurjcn/zvae032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 02/28/2024] [Accepted: 03/01/2024] [Indexed: 03/07/2024]
Abstract
BACKGROUND International studies have examined patients' views concerning the discussion of deactivating an implantable cardioverter defibrillator (ICD). Findings reported that many patients were either not informed about the subject or were informed late in their illness trajectory. AIM To explore healthcare professionals' perspectives on discussing ICD deactivation and identify priorities for clinical practice and future research. METHODS Eleven interviews were conducted, involving heart failure nurses, physicians, and an allied professional. All were responsible for the care of patients with an ICD, from the United Kingdom or Sweden. A semi-structured guide was used. All interviews were audio-recorded, transcribed, translated (as applicable) and analysed independently by experienced researchers, using framework analysis. Findings were presented, along with published work at a stakeholder meeting, and a consensus agreement was reached on priorities for clinical practice and future research. FINDINGS Four themes emerged from the exploratory interviews. Healthcare professionals described the discussion about deactivation as challenging, requiring compassion and involvement of family members. They agreed that the topic should be initiated prior to, or shortly after device implantation. This was reflected in the priorities to improve communication, through the increased availability and implementation of prompts and tools, as well as the provision of tailored information to patients and family members. Stakeholders recognised the future potential of digital technology in device education. CONCLUSIONS Discussing deactivation remains challenging. Healthcare professionals recognised the need to initiate the discussion early, with compassion and involvement of family members. Priorities were agreed by stakeholders, which require clinical implementation and further research.
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Affiliation(s)
- Loreena Hill
- School of Nursing & Midwifery, Queen's University, Belfast, Northern Ireland
- College of Nursing and Midwifery, Mohammed Bin Rashid University, Dubai, UAE
| | - Lorna Cassidy
- School of Nursing, Midwifery, and Health Systems, University College Dublin, Belfield, Dublin 4
| | - Lana Dixon
- Belfast Health and Social Care, Grosvenor Road, Belfast, Northern Ireland
| | - Donna Fitzsimons
- School of Nursing & Midwifery, Queen's University, Belfast, Northern Ireland
| | - Ingela Thylen
- Department of Cardiology in Linköping, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Tiny Jaarsma
- Department of Health, Medicine and Health Sciences, Linköping University, Linköping, Sweden
- Julius Center, University Medical Center Utrecht, the Netherlands
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3
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Cordero-Lanzac T, Capel Berdiell I, Airi A, Chung SH, Mancuso JL, Redekop EA, Fabris C, Figueroa-Quintero L, Navarro de Miguel JC, Narciso J, Ramos-Fernandez EV, Svelle S, Van Speybroeck V, Ruiz-Martínez J, Bordiga S, Olsbye U. Transitioning from Methanol to Olefins (MTO) toward a Tandem CO 2 Hydrogenation Process: On the Role and Fate of Heteroatoms (Mg, Si) in MAPO-18 Zeotypes. JACS Au 2024; 4:744-759. [PMID: 38425934 PMCID: PMC10900493 DOI: 10.1021/jacsau.3c00768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 01/26/2024] [Accepted: 01/26/2024] [Indexed: 03/02/2024]
Abstract
The tandem CO2 hydrogenation to hydrocarbons over mixed metal oxide/zeolite catalysts (OXZEO) is an efficient way of producing value-added hydrocarbons (platform chemicals and fuels) directly from CO2via methanol intermediate in a single reactor. In this contribution, two MAPO-18 zeotypes (M = Mg, Si) were tested and their performance was compared under methanol-to-olefins (MTO) conditions (350 °C, PCH3OH = 0.04 bar, 6.5 gCH3OH h-1 g-1), methanol/CO/H2 cofeed conditions (350 °C, PCH3OH/PCO/PH2 = 1:7.3:21.7 bar, 2.5 gCH3OH h-1 g-1), and tandem CO2 hydrogenation-to-olefin conditions (350 °C, PCO2/PH2 = 7.5:22.5 bar, 1.4-12.0 gMAPO-18 h molCO2-1). In the latter case, the zeotypes were mixed with a fixed amount of ZnO:ZrO2 catalyst, well-known for the conversion of CO2/H2 to methanol. Focus was set on the methanol conversion activity, product selectivity, and performance stability with time-on-stream. In situ and ex situ Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), solid-state nuclear magnetic resonance (NMR), sorption experiments, and ab initio molecular dynamics (AIMD) calculations were performed to correlate material performance with material characteristics. The catalytic tests demonstrated the better performance of MgAPO-18 versus SAPO-18 at MTO conditions, the much superior performance of MgAPO-18 under methanol/CO/H2 cofeeds, and yet the increasingly similar performance of the two materials under tandem conditions upon increasing the zeotype-to-oxide ratio in the tandem catalyst bed. In situ FT-IR measurements coupled with AIMD calculations revealed differences in the MTO initiation mechanism between the two materials. SAPO-18 promoted initial CO2 formation, indicative of a formaldehyde-based decarboxylation mechanism, while CO and ketene were the main constituents of the initiation pool in MgAPO-18, suggesting a decarbonylation mechanism. Under tandem CO2 hydrogenation conditions, the presence of high water concentrations and low methanol partial pressure in the reaction medium led to lower, and increasingly similar, methanol turnover frequencies for the zeotypes. Despite both MAPO-18 zeotypes showing signs of activity loss upon storage due to the interaction of the sites with ambient humidity, they presented a remarkable stability after reaching steady state under tandem reaction conditions and after steaming and regeneration cycles at high temperatures. Water adsorption experiments at room temperature confirmed this observation. The faster activity loss observed in the Mg version is assigned to its harder Mg2+-ion character and the higher concentration of CHA defects in the AEI structure, identified by solid-state NMR and XRD. The low stability of a MgAPO-34 zeotype (CHA structure) upon storage corroborated the relationship between CHA defects and instability.
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Affiliation(s)
- Tomás Cordero-Lanzac
- Department
of Chemistry, SMN Centre for Materials Science and Nanotechnology, University of Oslo, 0371 Oslo, Norway
| | - Izar Capel Berdiell
- Department
of Chemistry, SMN Centre for Materials Science and Nanotechnology, University of Oslo, 0371 Oslo, Norway
| | - Alessia Airi
- Department
of Chemistry, NIS Center and INSTM Reference Center, University of Turin, Turin 10125, Italy
| | - Sang-Ho Chung
- KAUST
Catalysis Center (KCC), King Abdullah University
of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Jenna L. Mancuso
- Center
for Molecular Modeling, Ghent University, Technologiepark 46, B-9052 Zwijnaarde, Belgium
| | - Evgeniy A. Redekop
- Department
of Chemistry, SMN Centre for Materials Science and Nanotechnology, University of Oslo, 0371 Oslo, Norway
| | - Claudia Fabris
- Department
of Chemistry, SMN Centre for Materials Science and Nanotechnology, University of Oslo, 0371 Oslo, Norway
| | - Leidy Figueroa-Quintero
- Inorganic
Chemistry Department, Laboratory of Advanced Materials, University Materials Institute of Alicante, University
of Alicante, Apartado 99, Alicante 03080, Spain
| | - Juan C. Navarro de Miguel
- KAUST
Catalysis Center (KCC), King Abdullah University
of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Javier Narciso
- Inorganic
Chemistry Department, Laboratory of Advanced Materials, University Materials Institute of Alicante, University
of Alicante, Apartado 99, Alicante 03080, Spain
| | - Enrique V. Ramos-Fernandez
- Inorganic
Chemistry Department, Laboratory of Advanced Materials, University Materials Institute of Alicante, University
of Alicante, Apartado 99, Alicante 03080, Spain
| | - Stian Svelle
- Department
of Chemistry, SMN Centre for Materials Science and Nanotechnology, University of Oslo, 0371 Oslo, Norway
| | | | - Javier Ruiz-Martínez
- KAUST
Catalysis Center (KCC), King Abdullah University
of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Silvia Bordiga
- Department
of Chemistry, NIS Center and INSTM Reference Center, University of Turin, Turin 10125, Italy
| | - Unni Olsbye
- Department
of Chemistry, SMN Centre for Materials Science and Nanotechnology, University of Oslo, 0371 Oslo, Norway
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Hare B, Garcia Carcamo RA, Daemen LL, Cheng Y, Getman RB, Sievers C. Poisoning of Pt/γ-Al 2O 3 Aqueous Phase Reforming Catalysts by Ketone and Diketone-Derived Surface Species. ACS Catal 2024; 14:1480-1493. [PMID: 38327647 PMCID: PMC10845116 DOI: 10.1021/acscatal.3c04774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 12/18/2023] [Accepted: 12/18/2023] [Indexed: 02/09/2024]
Abstract
Strong adsorption of ketone and diketone byproducts and their fragmentation products during the aqueous phase reforming of biomass derived oxygenates is believed to be responsible for the deactivation of supported Pt catalysts. This study involves a combined experimental and theoretical approach to demonstrate the interactions of several model di/ketone poisons with Pt/γ-Al2O3 catalysts. Particular di/ketones were selected to reveal the effects of hydroxyl groups (acetone, hydroxyacetone), conjugation with C=C bonds (mesityl oxide), intramolecular distance between carbonyls in diketones (2,3-butanedione, 2,4-pentanedione), and length of terminal alkyl chains (3,4-hexanedione). The formation of adsorbed carbon monoxide (1900-2100 cm-1) as a decarbonylation product was probed using infrared spectroscopy and to calculate the extent of poisoning during subsequent methanol dehydrogenation based on the reduction of the ν(C≡O) band integral relative to experiments in which only methanol was dosed. Small Pt particles appeared less active in decarbonylation and were perhaps poisoned by strongly adsorbed di/ketones on undercoordinated metal sites and bulky conjugated species formed on the γ-Al2O3 support from aldol self-condensation. Larger Pt particles were more resistant to di/ketone poisoning due to higher decarbonylation activity yet still fell short of the expected yield of adsorbed CO from subsequent methanol activity. Vibrational spectra acquired using inelastic neutron scattering showed evidence for strongly binding methyl and acyl groups resulting from di/ketone decarbonylation on a Pt sponge at 250 °C. Adsorption energies and molecular configurations were obtained for di/ketones on a Pt(111) slab using density functional theory, revealing potential descriptors for predicting decarbonylation activity on highly coordinated metal sites. Calculated reaction energies suggest it is energetically favorable to reform surface methyl groups into adsorbed CO and H. However, the rate of this surface reaction is limited by a high activation barrier indicating that either improved APR catalyst designs or regeneration procedures may be necessary.
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Affiliation(s)
- Bryan
J. Hare
- School
of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Ricardo A. Garcia Carcamo
- Department
of Chemical and Biomolecular Engineering, Clemson University, Clemson, South Carolina 29634, United States
| | - Luke L. Daemen
- Spallation
Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Yongqiang Cheng
- Spallation
Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Rachel B. Getman
- Department
of Chemical and Biomolecular Engineering, Clemson University, Clemson, South Carolina 29634, United States
| | - Carsten Sievers
- School
of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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5
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Portillo A, Parra O, Aguayo AT, Ereña J, Bilbao J, Ateka A. Kinetic Model for the Direct Conversion of CO 2/CO into Light Olefins over an In 2O 3-ZrO 2/SAPO-34 Tandem Catalyst. ACS Sustain Chem Eng 2024; 12:1616-1624. [PMID: 38303907 PMCID: PMC10828986 DOI: 10.1021/acssuschemeng.3c06914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 01/04/2024] [Accepted: 01/05/2024] [Indexed: 02/03/2024]
Abstract
An original kinetic model is proposed for the direct production of light olefins by hydrogenation of CO2/CO (COx) mixtures over an In2O3-ZrO2/SAPO-34 tandem catalyst, quantifying deactivation by coke. The reaction network comprises 12 individual reactions, and deactivation is quantified with expressions dependent on the concentration of methanol (as coke precursor) and H2O and H2 (as agents attenuating coke formation). The experimental results were obtained in a fixed-bed reactor under the following conditions: In2O3-ZrO2/SAPO-34 mass ratio, 0/1-1/0; 350-425 °C; 20-50 bar; H2/COx ratio, 1-3; CO2/COx ratio, 0-1; space time, 0-10 gIn2O3-ZrO2 h molC-1, 0-20 gSAPO-34 h molC-1; time, up to 500 h; H2O and CH3OH in the feed, up to 5% vol. The utility of the model for further scale-up studies is demonstrated by its application in optimizing the process variables (temperature, pressure, and CO2/COx ratio). The model predicts an olefin yield higher than 7% (selectivity above 60%), a COx conversion of 12% and a CO2 conversion of 16% at 415 °C and 50 bar, for a CO2/COx = 0.5 in the feed. Additionally, an analysis of the effect of In2O3-ZrO2 and SAPO-34 loading in the configuration of the tandem catalyst is conducted, yielding 17% olefins and complete conversion of CO2 under full water removal conditions.
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Affiliation(s)
- Ander Portillo
- Department of Chemical Engineering, University of the Basque Country UPV/EHU, P.O. Box 644, Bilbao 48080, Spain
| | - Onintze Parra
- Department of Chemical Engineering, University of the Basque Country UPV/EHU, P.O. Box 644, Bilbao 48080, Spain
| | - Andres T. Aguayo
- Department of Chemical Engineering, University of the Basque Country UPV/EHU, P.O. Box 644, Bilbao 48080, Spain
| | - Javier Ereña
- Department of Chemical Engineering, University of the Basque Country UPV/EHU, P.O. Box 644, Bilbao 48080, Spain
| | - Javier Bilbao
- Department of Chemical Engineering, University of the Basque Country UPV/EHU, P.O. Box 644, Bilbao 48080, Spain
| | - Ainara Ateka
- Department of Chemical Engineering, University of the Basque Country UPV/EHU, P.O. Box 644, Bilbao 48080, Spain
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Adediwura VA, Miao Y. Mechanistic Insights into Peptide Binding and Deactivation of an Adhesion G Protein-Coupled Receptor. Molecules 2023; 29:164. [PMID: 38202747 PMCID: PMC10780249 DOI: 10.3390/molecules29010164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 12/20/2023] [Accepted: 12/23/2023] [Indexed: 01/12/2024] Open
Abstract
Adhesion G protein-coupled receptors (ADGRGs) play critical roles in the reproductive, neurological, cardiovascular, and endocrine systems. In particular, ADGRG2 plays a significant role in Ewing sarcoma cell proliferation, parathyroid cell function, and male fertility. In 2022, a cryo-EM structure was reported for the active ADGRG2 bound by an optimized peptide agonist IP15 and the Gs protein. The IP15 peptide agonist was also modified to antagonists 4PH-E and 4PH-D with mutations of the 4PH residue to Glu and Asp, respectively. However, experimental structures of inactive antagonist-bound ADGRs remain to be resolved, and the activation mechanism of ADGRs such as ADGRG2 is poorly understood. Here, we applied Gaussian accelerated molecular dynamics (GaMD) simulations to probe conformational dynamics of the agonist- and antagonist-bound ADGRG2. By performing GaMD simulations, we were able to identify important low-energy conformations of ADGRG2 in the active, intermediate, and inactive states, as well as explore the binding conformations of each peptide. Moreover, our simulations revealed critical peptide-receptor residue interactions during the deactivation of ADGRG2. In conclusion, through GaMD simulations, we uncovered mechanistic insights into peptide (agonist and antagonist) binding and deactivation of the ADGRG2. These findings will potentially facilitate rational design of new peptide modulators of ADGRG2 and other ADGRs.
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Affiliation(s)
| | - Yinglong Miao
- Department of Pharmacology and Computational Medicine Program, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA;
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Velinova R, Todorova S, Kovacheva D, Kolev H, Karakirova Y, Markov P, Tumbalova K, Ivanov G, Naydenov A. Effect of TiO 2 on Pd/La 2O 3-CeO 2-Al 2O 3 Systems during Catalytic Oxidation of Methane in the Presence of H 2O and SO 2. Materials (Basel) 2023; 16:6784. [PMID: 37895766 PMCID: PMC10608221 DOI: 10.3390/ma16206784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/10/2023] [Accepted: 10/18/2023] [Indexed: 10/29/2023]
Abstract
New results on the effect of TiO2 on Pd/La2O3-CeO2-Al2O3 systems for catalytic oxidation of methane in the presence of H2O and SO2 have been received. Low-temperature N2-adsorption, XRD, SEM, HRTEM, XPS, EPR and FTIR techniques were used to characterize the catalyst. The presence of Ce3+ on the catalytic surface and in the volume near the lantana was revealed by EPR and XPS. After aging, the following changes are observed: (i) agglomeration of the Pd-clusters (from 8 nm to 12 nm); (ii) transformation of part of the TiO2 from anatase to larger particles of rutile; and (iii)-the increase in PdO/Pd-ratio above its optimum. The modification by Ti of the La2O3-CeO2-Al2O3 system leads to higher resistance towards the presence of SO2 most likely due to the prevailing formation of unstable surface sulfites instead of thermally stable sulfates. Based on kinetic model calculations, the reaction pathway over the Pd/La2O3-CeO2-TiO2-Al2O3 catalyst follows the Mars-van Krevelen mechanism. For evaluation of the possible practical application of the obtained material, a sample of Pd/La2O3-CeO2-TiO2-Al2O3, supported on rolled aluminum-containing stainless steel (Aluchrom VDM®), was prepared and tested. Methane oxidation in an industrial-scale monolithic reactor was simulated using a two-dimensional heterogeneous reactor model.
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Affiliation(s)
- Ralitsa Velinova
- Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 11, 1113 Sofia, Bulgaria
| | - Silviya Todorova
- Institute of Catalysis, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 11, 1113 Sofia, Bulgaria
| | - Daniela Kovacheva
- Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 11, 1113 Sofia, Bulgaria
| | - Hristo Kolev
- Institute of Catalysis, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 11, 1113 Sofia, Bulgaria
| | - Yordanka Karakirova
- Institute of Catalysis, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 11, 1113 Sofia, Bulgaria
| | - Pavel Markov
- Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 11, 1113 Sofia, Bulgaria
| | - Katerina Tumbalova
- Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 11, 1113 Sofia, Bulgaria
| | - Georgi Ivanov
- Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 11, 1113 Sofia, Bulgaria
| | - Anton Naydenov
- Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 11, 1113 Sofia, Bulgaria
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Mao X, Xing D, Liu D, Xu H, Hou L, Lin P, Xia Q, Lin Y, Shen G. Ecdysteroid UDP-Glucosyltransferase Expression in Beauveria bassiana Increases Its Pathogenicity against Early Instar Silkworm Larvae. J Fungi (Basel) 2023; 9:987. [PMID: 37888243 PMCID: PMC10607489 DOI: 10.3390/jof9100987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 09/29/2023] [Accepted: 10/01/2023] [Indexed: 10/28/2023] Open
Abstract
Beauveria bassiana (B. bassiana) is a broad-spectrum entomopathogenic fungus that can control pests in agriculture and forestry. In this study, encoding ecdysteroid uridine diphosphate glucosyltransferase gene (egt) was successfully screened in B. bassiana on the medium containing 500μg/mL G418 sulfate solution through the protoplast transformation method. This enzyme has the function of 20E (20-hydroxyecdysone) inactivation, thus increasing the mortality of the early instar larvae infected with B. bassiana. In this study, we transformed B. bassiana with the egt gene, which deactivates 20-hydroxyecdysone, a key hormone in insect development. The results showed that transgenic B. bassiana killed more silkworms of the 2nd instar larvae than the wild-type with a shorter LT50 time, which was reduced by approximately 20% (day 1 of the 2nd instar silkworm infection of B. bassiana) and 26.4% (day 2 of the 2nd instar silkworm infection of B. bassiana) compared to the wild-type, and also showed a higher mortality number before molting. The transgenic B. bassiana had a higher coverage of the body surface of silkworms compared to the wild type on the 3rd instar. In summary, improving entomopathogenic fungi using biological methods such as genetic engineering is feasible.
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Affiliation(s)
- Xueqin Mao
- Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, Biological Science Research Center, Southwest University, Chongqing 400716, China
| | - Dongxu Xing
- Sericultural & Agri-Food Research Institute Guangdong Academy of Agricultural Sciences, /Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Agricultural Products Processing, Guangzhou 510610, China
| | - Die Liu
- Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, Biological Science Research Center, Southwest University, Chongqing 400716, China
| | - Haoran Xu
- Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, Biological Science Research Center, Southwest University, Chongqing 400716, China
| | - Luyu Hou
- Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, Biological Science Research Center, Southwest University, Chongqing 400716, China
| | - Ping Lin
- Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, Biological Science Research Center, Southwest University, Chongqing 400716, China
| | - Qingyou Xia
- Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, Biological Science Research Center, Southwest University, Chongqing 400716, China
| | - Ying Lin
- Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, Biological Science Research Center, Southwest University, Chongqing 400716, China
| | - Guanwang Shen
- Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, Biological Science Research Center, Southwest University, Chongqing 400716, China
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9
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Chukwu VA, Smith JU, Strachan NJC, Avery LM. Modelling the deactivation of Escherichia coli in Nigerian soils amended with differently treated manures. J Appl Microbiol 2023:7157112. [PMID: 37156529 DOI: 10.1093/jambio/lxad098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
AIM This study aimed to simulate deactivation of E. coli in soils amended with cattle manure after burning, anaerobic digestion, composting or without treatment. METHOD AND RESULTS The Weibull survival function was used to describe deactivation of E. coli. Parameters for each treatment were determined using E. coli measurements from manure-amended soils and evaluated against measurements at different application rates. A statistically significant correlation and high coincidence between the simulated and measured values was obtained. The simulations revealed that although anaerobic digestion or burning of cattle manure effectively reduced the E. coli loads to background levels, burning retained very little nitrogen, so the ash residue was ineffective as an organic fertiliser. Anaerobic digestion was most effective at reducing E. coli levels while retaining a high proportion of N in the bioslurry residue, but the persistence of E. coli was higher than in compost. CONCLUSION The results from this study suggest that the safest method for production of organic fertiliser would involve anaerobic digestion to reduce E. coli followed by composting to reduce its persistence.
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Affiliation(s)
- Vince A Chukwu
- Environmental Sciences, School of Biological Sciences, University of Aberdeen, 23 St.Machar Drive, Aberdeen, AB24 3UU, Scotland, UK
| | - Jo U Smith
- Environmental Sciences, School of Biological Sciences, University of Aberdeen, 23 St.Machar Drive, Aberdeen, AB24 3UU, Scotland, UK
| | - Norval J C Strachan
- Environmental Sciences, School of Biological Sciences, University of Aberdeen, 23 St.Machar Drive, Aberdeen, AB24 3UU, Scotland, UK
| | - Lisa M Avery
- James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, United Kingdom
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10
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Escamilla-Mejía JC, Hidalgo-Carrillo J, Martín-Gómez J, López-Tenllado FJ, Estévez R, Marinas A, Urbano FJ. Biochars from Olive Stones as Carbonaceous Support in Pt/TiO 2-Carbon Photocatalysts and Application in Hydrogen Production from Aqueous Glycerol Photoreforming. Nanomaterials (Basel) 2023; 13:nano13091511. [PMID: 37177056 PMCID: PMC10179866 DOI: 10.3390/nano13091511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/21/2023] [Accepted: 04/27/2023] [Indexed: 05/15/2023]
Abstract
Several biochars were synthesized from olive stones and used as supports for TiO2, as an active semiconductor, and Pt as a co-catalyst (Pt/TiO2-PyCF and Pt/TiO2-AC). A third carbon-supported photocatalyst was prepared from commercial mesoporous carbon (Pt/TiO2-MCF). Moreover, a Pt/TiO2 solid based on Evonik P25 was used as a reference. The biochars used as supports transferred, to a large extent, their physical and chemical properties to the final photocatalysts. The synthesized catalysts were tested for hydrogen production from aqueous glycerol photoreforming. The results indicated that a mesoporous nature and small particle size of the photocatalyst lead to better H2 production. The analysis of the operational reaction conditions revealed that the H2 evolution rate was not proportional to the mass of the photocatalyst used, since, at high photocatalyst loading, the hydrogen production decreased because of the light scattering and reflection phenomena that caused a reduction in the light penetration depth. When expressed per gram of TiO2, the activity of Pt/TiO2-PyCF is almost 4-times higher than that of Pt/TiO2 (1079 and 273 mmol H2/gTiO2, respectively), which points to the positive effect of an adequate dispersion of a TiO2 phase on a carbonaceous support, forming a highly dispersed and homogeneously distributed titanium dioxide phase. Throughout a 12 h reaction period, the H2 production rate progressively decreases, while the CO2 production rate increases continuously. This behavior is compatible with an initial period when glycerol dehydrogenation to glyceraldehyde and/or dihydroxyacetone and hydrogen predominates, followed by a period in which comparatively slower C-C cleavage reactions begin to occur, thus generating both H2 and CO2.
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Affiliation(s)
- Juan Carlos Escamilla-Mejía
- Departamento de Química Orgánica, Instituto Químico para la Energía y el Medioambiente (IQUEMA), Edificio Marie Curie, Campus de Rabanales, Universidad de Córdoba, E-14071 Córdoba, Spain
| | - Jesús Hidalgo-Carrillo
- Departamento de Química Orgánica, Instituto Químico para la Energía y el Medioambiente (IQUEMA), Edificio Marie Curie, Campus de Rabanales, Universidad de Córdoba, E-14071 Córdoba, Spain
| | - Juan Martín-Gómez
- Departamento de Química Orgánica, Instituto Químico para la Energía y el Medioambiente (IQUEMA), Edificio Marie Curie, Campus de Rabanales, Universidad de Córdoba, E-14071 Córdoba, Spain
| | - Francisco J López-Tenllado
- Departamento de Química Orgánica, Instituto Químico para la Energía y el Medioambiente (IQUEMA), Edificio Marie Curie, Campus de Rabanales, Universidad de Córdoba, E-14071 Córdoba, Spain
| | - Rafael Estévez
- Departamento de Química Orgánica, Instituto Químico para la Energía y el Medioambiente (IQUEMA), Edificio Marie Curie, Campus de Rabanales, Universidad de Córdoba, E-14071 Córdoba, Spain
| | - Alberto Marinas
- Departamento de Química Orgánica, Instituto Químico para la Energía y el Medioambiente (IQUEMA), Edificio Marie Curie, Campus de Rabanales, Universidad de Córdoba, E-14071 Córdoba, Spain
| | - Francisco J Urbano
- Departamento de Química Orgánica, Instituto Químico para la Energía y el Medioambiente (IQUEMA), Edificio Marie Curie, Campus de Rabanales, Universidad de Córdoba, E-14071 Córdoba, Spain
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11
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Leonards CA, Harrison BJ, Jamieson AJ, Steward T, Lux S, Philipsen A, Davey CG. A distinct intra-individual suppression subnetwork in the brain's default mode network across cognitive tasks. Cereb Cortex 2023; 33:4553-4561. [PMID: 36130087 PMCID: PMC10110429 DOI: 10.1093/cercor/bhac361] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 08/17/2022] [Accepted: 08/18/2022] [Indexed: 11/13/2022] Open
Abstract
Suppression of the brain's default mode network (DMN) during external goal-directed cognitive tasks has been consistently observed in neuroimaging studies. However, emerging insights suggest the DMN is not a monolithic "task-negative" network but is comprised of subsystems that show functional heterogeneity. Despite considerable research interest, no study has investigated the consistency of DMN activity suppression across multiple cognitive tasks within the same individuals. In this study, 85 healthy 15- to 25-year-olds completed three functional magnetic resonance imaging tasks that were designed to reliably map DMN suppression from a resting baseline. Our findings revealed a distinct suppression subnetwork across the three tasks that comprised traditional DMN and adjacent regions. Specifically, common suppression was observed in the medial prefrontal cortex, the dorsal-to-mid posterior cingulate cortex extending to the precuneus, and the posterior insular cortex and parietal operculum. Further, we found the magnitude of suppression of these regions were significantly correlated within participants across tasks. Overall, our findings indicate that externally oriented cognitive tasks elicit common suppression of a distinct subnetwork of the broader DMN. The consistency to which the DMN is suppressed within individuals suggests a domain-general mechanism that may reflect a stable feature of cognitive function that optimizes external goal-directed behavior.
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Affiliation(s)
- Christine A Leonards
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Ben J Harrison
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Alec J Jamieson
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Trevor Steward
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne, Parkville, Victoria, 3010, Australia
- Melbourne School of Psychological Sciences, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Silke Lux
- Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, 53127, Germany
| | - Alexandra Philipsen
- Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, 53127, Germany
| | - Christopher G Davey
- Department of Psychiatry, The University of Melbourne, Parkville, Victoria, 3010, Australia
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12
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Kungl M, Vrticka P, Heinisch C, Beckmann MW, Fasching PA, Ziegler C, Spangler G. Deactivating attachment strategies associate with early processing of facial emotion and familiarity in middle childhood: an ERP study. Attach Hum Dev 2023; 25:199-217. [PMID: 36222516 DOI: 10.1080/14616734.2022.2132050] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Neurophysiological evidence suggests associations between attachment and the neural processing of emotion expressions. This study asks whether this relationship is also evident in middle childhood, and how it is affected by facial familiarity. Attachment strategies (deactivation, hyperactivation) were assessed in 51 children (9 - 11 years) using a story stem completion task. Event-related potentials (ERPs) were recorded during children's passive viewing of mother and stranger emotional faces (angry/happy). At the stage of facial information encoding (N250), attachment deactivation was associated with a pattern pointing to increased vigilance towards angry faces. Further, the attention-driven LPP was increased to happy mother faces as highly salient stimuli overall, but not in children scoring high on deactivation. These children did not discriminate between mothers' facial emotions and showed a general attentional withdrawal from facial stimuli. While our results on attachment deactivation support a two-stage processing model, no effect of hyperactivation was found.
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Affiliation(s)
- Melanie Kungl
- Department of Developmental Psychology and Developmental Psychopathology, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Pascal Vrticka
- Department of Psychology, Centre for Brain Science, University of Essex, Colchester, UK
| | - Christine Heinisch
- Department of Developmental Psychology and Developmental Psychopathology, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Matthias W Beckmann
- Department of Gynecology and Obstetrics, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Peter A Fasching
- Department of Gynecology and Obstetrics, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Clara Ziegler
- Department of Developmental Psychology and Developmental Psychopathology, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Gottfried Spangler
- Department of Developmental Psychology and Developmental Psychopathology, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
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Solano E, Dendooven J, Deduytsche D, Poonkottil N, Feng JY, Roeffaers MBJ, Detavernier C, Filez M. Metal Nanocatalyst Sintering Interrogated at Complementary Length Scales. Small 2023; 19:e2205217. [PMID: 36445117 DOI: 10.1002/smll.202205217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 10/05/2022] [Indexed: 06/16/2023]
Abstract
Metal nanoparticle (NP) sintering is a prime cause of catalyst degradation, limiting its economic lifetime and viability. To date, sintering phenomena are interrogated either at the bulk scale to probe averaged NP properties or at the level of individual NPs to visualize atomic motion. Yet, "mesoscale" strategies which bridge these worlds can chart NP populations at intermediate length scales but remain elusive due to characterization challenges. Here, a multi-pronged approach is developed to provide complementary information on Pt NP sintering covering multiple length scales. High-resolution scanning electron microscopy (HRSEM) and Monte Carlo simulation show that the size evolution of individual NPs depends on the number of coalescence events they undergo during their lifetime. In its turn, the probability of coalescence is strongly dependent on the NP's mesoscale environment, where local population heterogeneities generate NP-rich "hotspots" and NP-free zones during sintering. Surprisingly, advanced in situ synchrotron X-ray diffraction shows that not all NPs within the small NP sub-population are equally prone to sintering, depending on their crystallographic orientation on the support surface. The demonstrated approach shows that mesoscale heterogeneities in the NP population drive sintering and mitigation strategies demand their maximal elimination via advanced catalyst synthesis strategies.
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Affiliation(s)
- Eduardo Solano
- NCD-SWEET beamline, ALBA synchrotron light source, Cerdanyola del Vallès, 08290, Spain
| | - Jolien Dendooven
- Conformal Coating of Nanomaterials (CoCooN), Ghent University, Krijgslaan 281/S1, Ghent, 9000, Belgium
| | - Davy Deduytsche
- Conformal Coating of Nanomaterials (CoCooN), Ghent University, Krijgslaan 281/S1, Ghent, 9000, Belgium
| | - Nithin Poonkottil
- Conformal Coating of Nanomaterials (CoCooN), Ghent University, Krijgslaan 281/S1, Ghent, 9000, Belgium
| | - Ji-Yu Feng
- Conformal Coating of Nanomaterials (CoCooN), Ghent University, Krijgslaan 281/S1, Ghent, 9000, Belgium
| | - Maarten B J Roeffaers
- Centre for Membrane Separations, Adsorption, Catalysis and Spectroscopy for Sustainable Solutions (cMACS), KU Leuven, Celestijnenlaan, 200F, Leuven, 3001, Belgium
| | - Christophe Detavernier
- Conformal Coating of Nanomaterials (CoCooN), Ghent University, Krijgslaan 281/S1, Ghent, 9000, Belgium
| | - Matthias Filez
- Conformal Coating of Nanomaterials (CoCooN), Ghent University, Krijgslaan 281/S1, Ghent, 9000, Belgium
- Centre for Membrane Separations, Adsorption, Catalysis and Spectroscopy for Sustainable Solutions (cMACS), KU Leuven, Celestijnenlaan, 200F, Leuven, 3001, Belgium
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Bickel E, Gounder R. Hydrocarbon Products Occluded within Zeolite Micropores Impose Transport Barriers that Regulate Brønsted Acid-Catalyzed Propene Oligomerization. JACS Au 2022; 2:2585-2595. [PMID: 36465546 PMCID: PMC9709944 DOI: 10.1021/jacsau.2c00462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/03/2022] [Accepted: 10/06/2022] [Indexed: 06/17/2023]
Abstract
Brønsted acid zeolites catalyze alkene oligomerization to heavier hydrocarbon products of varied size and branching. Propene dimerization rates decrease monotonically with increasing crystallite size for MFI zeolites synthesized with fixed H+-site density, revealing the strong influence of intrazeolite transport limitations on measured rates, which has gone unrecognized in previous studies. Transient changes in dimerization rates upon step-changes in reactant pressure (150-470 kPa C3H6) or temperature (483-523 K) reveal that intrazeolite diffusion limitations become more severe under reaction conditions that favor the formation of heavier products. Together with effectiveness factor formalisms, these data reveal that product and reactant diffusion, and consequently oligomerization rates and selectivity, are governed by the composition of hydrocarbon products that accumulate within zeolitic micropores during alkene oligomerization. This occluded organic phase strongly influences rates and selectivities of alkene oligomerization on medium-pore zeolites (MFI, MEL, TON). Recognizing the coupled influences of kinetic factors and intrazeolite transport limitations imposed by occluded reaction products provides opportunities to competently tailor rates and selectivity in alkene oligomerization and other molecular chain-growth reactions through judicious selection of zeolite topology and reaction conditions.
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15
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Castellano D, Wu K, Keramidas A, Lu W. Shisa7-Dependent Regulation of GABA A Receptor Single-Channel Gating Kinetics. J Neurosci 2022; 42:8758-8766. [PMID: 36216503 PMCID: PMC9698691 DOI: 10.1523/jneurosci.0510-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 08/19/2022] [Accepted: 09/27/2022] [Indexed: 12/29/2022] Open
Abstract
GABAA receptors (GABAARs) mediate the majority of fast inhibitory transmission throughout the brain. Although it is widely known that pore-forming subunits critically determine receptor function, it is unclear whether their single-channel properties are modulated by GABAAR-associated transmembrane proteins. We previously identified Shisa7 as a GABAAR auxiliary subunit that modulates the trafficking, pharmacology, and deactivation properties of these receptors. However, whether Shisa7 also regulates GABAAR single-channel properties has yet to be determined. Here, we performed single-channel recordings of α2β3γ2L GABAARs cotransfected with Shisa7 in HEK293T cells and found that while Shisa7 does not change channel slope conductance, it reduced the frequency of receptor openings. Importantly, Shisa7 modulates GABAAR gating by decreasing the duration and open probability within bursts. Through kinetic analysis of individual dwell time components, activation modeling, and macroscopic simulations, we demonstrate that Shisa7 accelerates GABAAR deactivation by governing the time spent between close and open states during gating. Together, our data provide a mechanistic basis for how Shisa7 controls GABAAR gating and reveal for the first time that GABAAR single-channel properties can be modulated by an auxiliary subunit. These findings shed light on processes that shape the temporal dynamics of GABAergic transmission.SIGNIFICANCE STATEMENT Although GABAA receptor (GABAAR) single-channel properties are largely determined by pore-forming subunits, it remains unknown whether they are also controlled by GABAAR-associated transmembrane proteins. Here, we show that Shisa7, a recently identified GABAAR auxiliary subunit, modulates GABAAR activation by altering single-channel burst kinetics. These results reveal that Shisa7 primarily decreases the duration and open probability of receptor burst activity during gating, leading to accelerated GABAAR deactivation. These experiments are the first to assess the gating properties of GABAARs in the presence of an auxiliary subunit and provides a kinetic basis for how Shisa7 modifies temporal attributes of GABAergic transmission at the single-channel level.
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Affiliation(s)
- David Castellano
- Synapse and Neural Circuit Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892
| | - Kunwei Wu
- Synapse and Neural Circuit Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892
| | - Angelo Keramidas
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Wei Lu
- Synapse and Neural Circuit Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892
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16
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Yigit N, Genest A, Terloev S, Möller J, Rupprechter G. Active sites and deactivation of room temperature CO oxidation on Co 3O 4catalysts: combined experimental and computational investigations. J Phys Condens Matter 2022; 34:354001. [PMID: 35588721 DOI: 10.1088/1361-648x/ac718b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
Co3O4is a well-known low temperature CO oxidation catalyst, but it often suffers from deactivation. We have thus examined room temperature (RT) CO oxidation on Co3O4catalysts by operando DSC, TGA and MS measurements, as well as by pulsed chemisorption to differentiate the contributions of CO adsorption and reaction to CO2. Catalysts pretreated in oxygen at 400 °C are most active, with the initial interaction of CO and Co3O4being strongly exothermic and with maximum amounts of CO adsorption and reaction. The initially high RT activity then levels-off, suggesting that the oxidative pretreatment creates an oxygen-rich reactive Co3O4surface that upon reaction onset loses its most active oxygen. This specific active oxygen is not reestablished by gas phase O2during the RT reaction. When the reaction temperature is increased to 150 °C, full conversion can be maintained for 100 h, and even after cooling back to RT. Apparently, deactivating species are avoided this way, whereas exposing the active surface even briefly to pure CO leads to immediate deactivation. Computational modeling using DFT helped to identify the CO adsorption sites, determine oxygen vacancy formation energies and the origin of deactivation. A new species of CO bonded to oxygen vacancies at RT was identified, which may block a vacancy site from further reaction unless CO is removed at higher temperature. The interaction between oxygen vacancies was found to be small, so that in the active state several lattice oxygen species are available for reaction in parallel.
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Affiliation(s)
- Nevzat Yigit
- Institute of Materials Chemistry, TU Wien, Getreidemarkt 9, 1060 Vienna, Austria
| | - Alexander Genest
- Institute of Materials Chemistry, TU Wien, Getreidemarkt 9, 1060 Vienna, Austria
| | - Schamil Terloev
- Institute of Materials Chemistry, TU Wien, Getreidemarkt 9, 1060 Vienna, Austria
| | - Jury Möller
- Institute of Materials Chemistry, TU Wien, Getreidemarkt 9, 1060 Vienna, Austria
| | - Günther Rupprechter
- Institute of Materials Chemistry, TU Wien, Getreidemarkt 9, 1060 Vienna, Austria
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17
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Romano V, Ruocco MR, Carotenuto P, Barbato A, Venuta A, Acampora V, De Lella S, Vigliar E, Iaccarino A, Troncone G, Calì G, Insabato L, Russo D, Franco B, Masone S, Velotti N, Accurso A, Pellegrino T, Fiume G, Belviso I, Montagnani S, Avagliano A, Arcucci A. Generation and Characterization of a Tumor Stromal Microenvironment and Analysis of Its Interplay with Breast Cancer Cells: An In Vitro Model to Study Breast Cancer-Associated Fibroblast Inactivation. Int J Mol Sci 2022; 23:ijms23126875. [PMID: 35743318 PMCID: PMC9224278 DOI: 10.3390/ijms23126875] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 06/14/2022] [Accepted: 06/17/2022] [Indexed: 02/01/2023] Open
Abstract
Breast cancer-associated fibroblasts (BCAFs), the most abundant non-cancer stromal cells of the breast tumor microenvironment (TME), dramatically sustain breast cancer (BC) progression by interacting with BC cells. BCAFs, as well as myofibroblasts, display an up regulation of activation and inflammation markers represented by α-smooth muscle actin (α-SMA) and cyclooxygenase 2 (COX-2). BCAF aggregates have been identified in the peripheral blood of metastatic BC patients. We generated an in vitro stromal model consisting of human primary BCAFs grown as monolayers or 3D cell aggregates, namely spheroids and reverted BCAFs, obtained from BCAF spheroids reverted to 2D cell adhesion growth after 216 h of 3D culture. We firstly evaluated the state of activation and inflammation and the mesenchymal status of the BCAF monolayers, BCAF spheroids and reverted BCAFs. Then, we analyzed the MCF-7 cell viability and migration following treatment with conditioned media from the different BCAF cultures. After 216 h of 3D culture, the BCAFs acquired an inactivated phenotype, associated with a significant reduction in α-SMA and COX-2 protein expression. The deactivation of the BCAF spheroids at 216 h was further confirmed by the cytostatic effect exerted by their conditioned medium on MCF-7 cells. Interestingly, the reverted BCAFs also retained a less activated phenotype as indicated by α-SMA protein expression reduction. Furthermore, the reverted BCAFs exhibited a reduced pro-tumor phenotype as indicated by the anti-migratory effect exerted by their conditioned medium on MCF-7 cells. The deactivation of BCAFs without drug treatment is possible and leads to a reduced capability of BCAFs to sustain BC progression in vitro. Consequently, this study could be a starting point to develop new therapeutic strategies targeting BCAFs and their interactions with cancer cells.
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Affiliation(s)
- Veronica Romano
- Department of Public Health, University of Naples Federico II, 80131 Naples, Italy; (V.R.); (A.V.); (V.A.); (S.D.L.); (E.V.); (A.I.); (G.T.); (I.B.); (S.M.)
| | - Maria Rosaria Ruocco
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, 80131 Naples, Italy;
| | - Pietro Carotenuto
- TIGEM, Telethon Institute of Genetics and Medicine, 80078 Naples, Italy; (P.C.); (A.B.); (B.F.)
- Medical Genetics, Department of Translational Medical Science, University of Naples Federico II, 80131 Naples, Italy
| | - Anna Barbato
- TIGEM, Telethon Institute of Genetics and Medicine, 80078 Naples, Italy; (P.C.); (A.B.); (B.F.)
| | - Alessandro Venuta
- Department of Public Health, University of Naples Federico II, 80131 Naples, Italy; (V.R.); (A.V.); (V.A.); (S.D.L.); (E.V.); (A.I.); (G.T.); (I.B.); (S.M.)
| | - Vittoria Acampora
- Department of Public Health, University of Naples Federico II, 80131 Naples, Italy; (V.R.); (A.V.); (V.A.); (S.D.L.); (E.V.); (A.I.); (G.T.); (I.B.); (S.M.)
| | - Sabrina De Lella
- Department of Public Health, University of Naples Federico II, 80131 Naples, Italy; (V.R.); (A.V.); (V.A.); (S.D.L.); (E.V.); (A.I.); (G.T.); (I.B.); (S.M.)
| | - Elena Vigliar
- Department of Public Health, University of Naples Federico II, 80131 Naples, Italy; (V.R.); (A.V.); (V.A.); (S.D.L.); (E.V.); (A.I.); (G.T.); (I.B.); (S.M.)
| | - Antonino Iaccarino
- Department of Public Health, University of Naples Federico II, 80131 Naples, Italy; (V.R.); (A.V.); (V.A.); (S.D.L.); (E.V.); (A.I.); (G.T.); (I.B.); (S.M.)
| | - Giancarlo Troncone
- Department of Public Health, University of Naples Federico II, 80131 Naples, Italy; (V.R.); (A.V.); (V.A.); (S.D.L.); (E.V.); (A.I.); (G.T.); (I.B.); (S.M.)
| | - Gaetano Calì
- IEOS Istituto di Endocrinologia e Oncologia Sperimentale ‘G. Salvatore’, National Council of Research, 80131 Naples, Italy;
| | - Luigi Insabato
- Anatomic Pathology Unit, Department of Advanced Biomedical Sciences, School of Medicine, University of Naples Federico II, 80131 Naples, Italy; (L.I.); (D.R.)
| | - Daniela Russo
- Anatomic Pathology Unit, Department of Advanced Biomedical Sciences, School of Medicine, University of Naples Federico II, 80131 Naples, Italy; (L.I.); (D.R.)
| | - Brunella Franco
- TIGEM, Telethon Institute of Genetics and Medicine, 80078 Naples, Italy; (P.C.); (A.B.); (B.F.)
- Medical Genetics, Department of Translational Medical Science, University of Naples Federico II, 80131 Naples, Italy
- Scuola Superiore Meridionale, School for Advanced Studies, 80138 Naples, Italy
| | - Stefania Masone
- Department of Clinical Medicine and Surgery, University of Naples Federico II, 80131 Naples, Italy;
| | - Nunzio Velotti
- Department of Advanced Biochemical Sciences, University of Naples Federico II, 80131 Naples, Italy;
| | - Antonello Accurso
- Department of General, Oncological, Bariatric and Endocrine-Metabolic Surgery, University of Naples Federico II, 80131 Naples, Italy;
| | - Tommaso Pellegrino
- DAI Chirurgia Generale, Endocrinologia, Ortopedia e Riabilitazione, Azienda Ospedaliera Universitaria Federico II, 80131 Naples, Italy;
| | - Giuseppe Fiume
- Department of Experimental and Clinical Medicine, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy;
| | - Immacolata Belviso
- Department of Public Health, University of Naples Federico II, 80131 Naples, Italy; (V.R.); (A.V.); (V.A.); (S.D.L.); (E.V.); (A.I.); (G.T.); (I.B.); (S.M.)
| | - Stefania Montagnani
- Department of Public Health, University of Naples Federico II, 80131 Naples, Italy; (V.R.); (A.V.); (V.A.); (S.D.L.); (E.V.); (A.I.); (G.T.); (I.B.); (S.M.)
| | - Angelica Avagliano
- Department of Public Health, University of Naples Federico II, 80131 Naples, Italy; (V.R.); (A.V.); (V.A.); (S.D.L.); (E.V.); (A.I.); (G.T.); (I.B.); (S.M.)
- Correspondence: (A.A.); (A.A.); Tel.: +39-081-7463422 (A.A. & A.A.)
| | - Alessandro Arcucci
- Department of Public Health, University of Naples Federico II, 80131 Naples, Italy; (V.R.); (A.V.); (V.A.); (S.D.L.); (E.V.); (A.I.); (G.T.); (I.B.); (S.M.)
- Correspondence: (A.A.); (A.A.); Tel.: +39-081-7463422 (A.A. & A.A.)
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Mayhew SD, Coleman SC, Mullinger KJ, Can C. Across the adult lifespan the ipsilateral sensorimotor cortex negative BOLD response exhibits decreases in magnitude and spatial extent suggesting declining inhibitory control. Neuroimage 2022; 253:119081. [PMID: 35278710 PMCID: PMC9130740 DOI: 10.1016/j.neuroimage.2022.119081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 03/07/2022] [Accepted: 03/07/2022] [Indexed: 11/27/2022] Open
Abstract
Ipsilateral sensorimotor (iSM1) cortex negative BOLD responses (NBR) are observed to unilateral tasks and are thought to reflect a functionally relevant component of sensorimotor inhibition. Evidence suggests that sensorimotor inhibitory mechanisms degrade with age, along with aspects of motor ability and dexterity. However, understanding of age-related changes to NBR is restricted by limited comparisons between young vs old adults groups with relatively small samples sizes. Here we analysed a BOLD fMRI dataset (obtained from the CamCAN repository) of 581 healthy subjects, gender-balanced, sampled from the whole adult lifespan performing a motor response task to an audio-visual stimulus. We aimed to investigate how sensorimotor and default-mode NBR characteristics of magnitude, spatial extent and response shape alter at every decade of the aging process. A linear decrease in iSM1 NBR magnitude was observed across the whole lifespan whereas the contralateral sensorimotor (cSM1) PBR magnitude was unchanged. An age-related decrease in the spatial extent of NBR and an increase in the ipsilateral positive BOLD response (PBR) was observed. This occurred alongside an increasing negative correlation between subject's iSM1 NBR and cSM1 PBR magnitude, reflecting a change in the balance between cortical excitation and inhibition. Conventional GLM analysis, using a canonical haemodynamic response (HR) function, showed disappearance of iSM1 NBR in subjects over 50 years of age. However, a deconvolution analysis showed that the shape of the iSM1 HR altered throughout the lifespan, with delayed time-to-peak and decreased magnitude. The most significant decreases in iSM1 HR magnitude occurred in older age (>60 years) but the first changes in shape and timing occurred as early as 30 years, suggesting possibility of separate mechanisms underlying these alterations. Reanalysis using data-driven HRs for each decade detected significant sensorimotor NBR into late older age, showing the importance of taking changes in HR morphology into account in fMRI aging studies. These results may reflect fMRI measures of the age-related decreases in transcollosal inhibition exerted upon ipsilateral sensorimotor cortex and alterations to the excitatory-inhibitory balance in the sensorimotor network.
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Affiliation(s)
- Stephen D Mayhew
- Centre for Human Brain Health (CHBH), School of Psychology, University of Birmingham, Birmingham, UK.
| | - Sebastian C Coleman
- Sir Peter Mansfield Imaging Centre (SPMIC), School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Karen J Mullinger
- Centre for Human Brain Health (CHBH), School of Psychology, University of Birmingham, Birmingham, UK; Sir Peter Mansfield Imaging Centre (SPMIC), School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Cam Can
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
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19
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Kim DJ, Zhu Q, Rigby K, Wu X, Kim JH, Kim JH. A Protocol for Electrocatalyst Stability Evaluation: H 2O 2 Electrosynthesis for Industrial Wastewater Treatment. Environ Sci Technol 2022; 56:1365-1375. [PMID: 34958567 DOI: 10.1021/acs.est.1c06850] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Electrocatalysis has been proposed as a versatile technology for wastewater treatment and reuse. While enormous attention has been centered on material synthesis and design, the practicality of such catalyst materials remains clouded by a lack of both stability assessment protocols and understanding of deactivation mechanisms. In this study, we develop a protocol to identify the wastewater constituents most detrimental to electrocatalyst performance in a timely manner and elucidate the underlying phenomena behind these losses. Synthesized catalysts are electrochemically investigated in various electrolytes based on real industrial effluent characteristics and methodically subjected to a sequence of chronopotentiometric stability tests, in which each stage presents harsher operating conditions. To showcase, oxidized carbon black is chosen as a model catalyst for the electrosynthesis of H2O2, a precursor for advanced oxidation processes. Results illustrate severe losses in catalyst activity and/or selectivity upon the introduction of metal pollutants, namely magnesium and zinc. The insights garnered from this protocol serve to translate lab-scale electrocatalyst developments into practical technologies for industrial water treatment purposes.
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Affiliation(s)
- David J Kim
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States
| | - Qianhong Zhu
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States
| | - Kali Rigby
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States
| | - Xuanhao Wu
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States
| | - Jin Hyun Kim
- Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland
| | - Jae-Hong Kim
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States
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20
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Torres-Liñán J, Ruiz-Rosas R, Rosas JM, Rodríguez-Mirasol J, Cordero T. A Kinetic Model Considering Catalyst Deactivation for Methanol-to-Dimethyl Ether on a Biomass-Derived Zr/P-Carbon Catalyst. Materials (Basel) 2022; 15:596. [PMID: 35057313 DOI: 10.3390/ma15020596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 01/03/2022] [Accepted: 01/10/2022] [Indexed: 12/02/2022]
Abstract
A Zr-loaded P-containing biomass-derived activated carbon (ACPZr) has been tested for methanol dehydration between 450 and 550 °C. At earlier stages, methanol conversion was complete, and the reaction product was mainly dimethyl ether (DME), although coke, methane, hydrogen and CO were also observed to a lesser extent. The catalyst was slowly deactivated with time-on-stream (TOS), but maintained a high selectivity to DME (>80%), with a higher yield to this product than 20% for more than 24 h at 500 °C. A kinetic model was developed for methanol dehydration reaction, which included the effect of the inhibition of water and the deactivation of the catalyst by coke. The study of stoichiometric rates pointed out that coke could be produced through a formaldehyde intermediate, which might, alternatively, decompose into CO and H2. On the other hand, the presence of 10% water in the feed did not affect the rate of coke formation, but produced a reduction of 50% in the DME yield, suggesting a reversible competitive adsorption of water. A Langmuir–Hinshelwood reaction mechanism was used to develop a kinetic model that considered the deactivation of the catalyst. Activation energy values of 65 and 51 kJ/mol were obtained for DME and methane production in the temperature range from 450 °C to 550 °C. On the other hand, coke formation as a function of time on stream (TOS) was also modelled and used as the input for the deactivation function of the model, which allowed for the successful prediction of the DME, CH4 and CO yields in the whole evaluated TOS interval.
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21
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Harrison BJ, Davey CG, Savage HS, Jamieson AJ, Leonards CA, Moffat BA, Glarin RK, Steward T. Dynamic Subcortical Modulators of Human Default Mode Network Function. Cereb Cortex 2021; 32:4345-4355. [PMID: 34974620 PMCID: PMC9528899 DOI: 10.1093/cercor/bhab487] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 11/29/2022] Open
Abstract
The brain’s “default mode network” (DMN) enables flexible switching between internally and externally focused cognition. Precisely how this modulation occurs is not well understood, although it may involve key subcortical mechanisms, including hypothesized influences from the basal forebrain (BF) and mediodorsal thalamus (MD). Here, we used ultra-high field (7 T) functional magnetic resonance imaging to examine the involvement of the BF and MD across states of task-induced DMN activity modulation. Specifically, we mapped DMN activity suppression (“deactivation”) when participants transitioned between rest and externally focused task performance, as well as DMN activity engagement (“activation”) when task performance was internally (i.e., self) focused. Consistent with recent rodent studies, the BF showed overall activity suppression with DMN cortical regions when comparing the rest to external task conditions. Further analyses, including dynamic causal modeling, confirmed that the BF drove changes in DMN cortical activity during these rest-to-task transitions. The MD, by comparison, was specifically engaged during internally focused cognition and demonstrated a broad excitatory influence on DMN cortical activation. These results provide the first direct evidence in humans of distinct BF and thalamic circuit influences on the control of DMN function and suggest novel mechanistic avenues for ongoing translational research.
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Affiliation(s)
- Ben J Harrison
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Christopher G Davey
- Department of Psychiatry, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Hannah S Savage
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Alec J Jamieson
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Christine A Leonards
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Bradford A Moffat
- Melbourne Brain Centre Imaging Unit, Department of Radiology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Rebecca K Glarin
- Melbourne Brain Centre Imaging Unit, Department of Radiology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Trevor Steward
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne, Parkville, Victoria 3010, Australia.,Melbourne School of Psychological Sciences, The University of Melbourne, Parkville, Victoria 3010, Australia
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22
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Lee CS, Guo S, Rho H, Levi J, Garcia-Segura S, Wong MS, Gardea-Torresdey J, Westerhoff P. Unified Metallic Catalyst Aging Strategy and Implications for Water Treatment. Environ Sci Technol 2021; 55:10.1021/acs.est.1c02364. [PMID: 34309365 PMCID: PMC9720895 DOI: 10.1021/acs.est.1c02364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Heterogeneous catalysis holds great promise for oxidizing or reducing a range of pollutants in water. A well-recognized, but understudied, barrier to implement catalytic treatment centers around fouling or aging over time of the catalyst surfaces. To better understand how to study catalyst fouling or aging, we selected a representative bimetallic catalyst (Pd-In supported on Al2O3), which holds promise to reduce nitrate to innocuous nitrogen gas byproducts upon hydrogen addition, and six model solutions (deionized water, sodium hypochlorite, sodium borohydride, acetic acid, sodium sulfide, and tap water). Our novel aging experimental apparatus permitted single passage of each model solution, separately, through a small packed-bed reactor containing replicate bimetallic catalyst "beds" that could be sacrificed weekly for off-line characterization to quantify impacts of fouling or aging. The composition of the model solutions led to the following gradual changes in surface composition, morphology, or catalytic reactivity: (i) formation of passivating species, (ii) decreased catalytic sites due to metal leaching under acid conditions or sulfide poisoning, (iii) dissolution and/or transformation of indium, (iv) formation of new catalytic sites by the introduction of an additional metallic element, and (v) oxidative etching. The model solution water chemistry captured a wide range of conditions likely to be encountered in potable or industrial water treatment. Aging-induced changes altered catalytic activity and provided insights into potential strategies to improve long-term catalyst operations for water treatment.
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Affiliation(s)
- Chung-Seop Lee
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-3005, USA
| | - Sujin Guo
- Department of Civil and Environmental Engineering, Rice University, 6100 S. Main Street, Houston, TX 77005, USA
| | - Hojung Rho
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-3005, USA
| | - Juliana Levi
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-3005, USA
| | - Sergi Garcia-Segura
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-3005, USA
| | - Michael S. Wong
- Department of Civil and Environmental Engineering, Rice University, 6100 S. Main Street, Houston, TX 77005, USA
| | - Jorge Gardea-Torresdey
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, El Paso, TX, 79968, USA
| | - Paul Westerhoff
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-3005, USA
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23
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Naito E, Morita T, Asada M. Importance of the Primary Motor Cortex in Development of Human Hand/Finger Dexterity. Cereb Cortex Commun 2021; 1:tgaa085. [PMID: 34296141 PMCID: PMC8152843 DOI: 10.1093/texcom/tgaa085] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 11/02/2020] [Indexed: 11/18/2022] Open
Abstract
Hand/finger dexterity is well-developed in humans, and the primary motor cortex (M1) is believed to play a particularly important role in it. Here, we show that efficient recruitment of the contralateral M1 and neuronal inhibition of the ipsilateral M1 identified by simple hand motor and proprioceptive tasks are related to hand/finger dexterity and its ontogenetic development. We recruited healthy, right-handed children (n = 21, aged 8–11 years) and adults (n = 23, aged 20–26 years) and measured their brain activity using functional magnetic resonance imaging during active and passive right-hand extension–flexion tasks. We calculated individual active control-related activity (active–passive) to evaluate efficient brain activity recruitment and individual task-related deactivation (neuronal inhibition) during both tasks. Outside the scanner, participants performed 2 right-hand dexterous motor tasks, and we calculated the hand/finger dexterity index (HDI) based on their individual performance. Participants with a higher HDI exhibited less active control-related activity in the contralateral M1 defined by the active and passive tasks, independent of age. Only children with a higher HDI exhibited greater ipsilateral M1 deactivation identified by these tasks. The results imply that hand/finger dexterity can be predicted by recruitment and inhibition styles of the M1 during simple hand sensory–motor tasks.
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Affiliation(s)
- Eiichi Naito
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT), Suita, Osaka 565-0871, Japan
| | - Tomoyo Morita
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT), Suita, Osaka 565-0871, Japan
| | - Minoru Asada
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT), Suita, Osaka 565-0871, Japan
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24
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Álvarez Moreno A, Ramirez-Reina T, Ivanova S, Roger AC, Centeno MÁ, Odriozola JA. Bimetallic Ni-Ru and Ni-Re Catalysts for Dry Reforming of Methane: Understanding the Synergies of the Selected Promoters. Front Chem 2021; 9:694976. [PMID: 34307298 PMCID: PMC8292677 DOI: 10.3389/fchem.2021.694976] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/14/2021] [Indexed: 11/13/2022] Open
Abstract
Designing an economically viable catalyst that maintains high catalytic activity and stability is the key to unlock dry reforming of methane (DRM) as a primary strategy for biogas valorization. Ni/Al2O3 catalysts have been widely used for this purpose; however, several modifications have been reported in the last years in order to prevent coke deposition and deactivation of the samples. Modification of the acidity of the support and the addition of noble metal promoters are between the most reported strategies. Nevertheless, in the task of designing an active and stable catalyst for DRM, the selection of an appropriate noble metal promoter is turning more challenging owing to the lack of homogeneity of the different studies. Therefore, this research aims to compare Ru (0.50 and 2.0%) and Re (0.50 and 2.0%) as noble metal promoters for a Ni/MgAl2O4 catalyst under the same synthesis and reaction conditions. Catalysts were characterized by XRF, BET, XRD, TPR, hydrogen chemisorption (H2-TPD), and dry reforming reaction tests. Results show that both promoters increase Ni reducibility and dispersion. However, Ru seems a better promoter for DRM since 0.50% of Ru increases the catalytic activity in 10% and leads to less coke deposition.
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Affiliation(s)
- Andrea Álvarez Moreno
- Estado Sólido y Catálisis Ambiental, Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia, Ciudad Universitaria, Bogotá, Colombia
| | - Tomás Ramirez-Reina
- Centro Mixto Universidad de Sevilla-CSIC, Instituto de Ciencia de Materiales de Sevilla, Sevilla, Spain.,Department of Chemical and Process Engineering, University of Surrey, Guildford, United Kingdom
| | - Svetlana Ivanova
- Centro Mixto Universidad de Sevilla-CSIC, Instituto de Ciencia de Materiales de Sevilla, Sevilla, Spain
| | - Anne-Cécile Roger
- ICPEES, équipe Energie et Carburants pour un Environnement Durable, UMR CNRS, Strasbourg, France
| | - Miguel Ángel Centeno
- Centro Mixto Universidad de Sevilla-CSIC, Instituto de Ciencia de Materiales de Sevilla, Sevilla, Spain
| | - José Antonio Odriozola
- Centro Mixto Universidad de Sevilla-CSIC, Instituto de Ciencia de Materiales de Sevilla, Sevilla, Spain.,Department of Chemical and Process Engineering, University of Surrey, Guildford, United Kingdom
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25
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Chen G, Xiong S, Chen X, Chu X, Yin R, Liu C, Chen J, Li J. Penetration of Arsenic and Deactivation of a Honeycomb V 2O 5-WO 3/TiO 2 Catalyst in a Glass Furnace. Environ Sci Technol 2021; 55:11368-11374. [PMID: 34137252 DOI: 10.1021/acs.est.1c01314] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Deactivation of honeycomb V2O5-WO3/TiO2 catalysts by arsenic has been studied widely in coal-fired power plants but rarely in glass furnaces. In this paper, deactivated catalysts that had been used for more than 4000 h were analyzed. We maintained the catalysts in their original monolith shape to retain their adhered substance and used appropriate methods to strip the substance layer by layer. With various characterization techniques, it was determined that the adhered substance was composed almost entirely of Na2SO4 and CaSO4. We also quantified the penetration depth of arsenic visually, which was more than 370 μm. A three-stage penetration and deactivation process induced by arsenic was proposed. It was pointed out that molten and volatile As2O3 played a key role in the deactivation process, while substances in the solid state had little impact on the deep bulk of the catalyst. In this study, we proposed an integrated deactivation process consisting of adhesion, penetration, and deactivation in a honeycomb V2O5-WO3/TiO2 catalyst by arsenic in a glass furnace. Finally, we also provided guidance on alleviating the deactivation caused by arsenic. The key is to convert molten and volatile As2O3 to solid-state substances before it contacts the catalyst.
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Affiliation(s)
- Gongda Chen
- State Key Joint Laboratory of Environment Simulation and Pollution Control, National Engineering Laboratory for Multi Flue Gas Pollution Control Technology and Equipment, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Shangchao Xiong
- State Key Joint Laboratory of Environment Simulation and Pollution Control, National Engineering Laboratory for Multi Flue Gas Pollution Control Technology and Equipment, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Xiaoping Chen
- State Key Joint Laboratory of Environment Simulation and Pollution Control, National Engineering Laboratory for Multi Flue Gas Pollution Control Technology and Equipment, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Xuefeng Chu
- Key Laboratory of Architectural Cold Climate Energy Management, Ministry of Education, Jilin Jianzhu University, Changchun 130118, China
| | - Rongqiang Yin
- State Key Joint Laboratory of Environment Simulation and Pollution Control, National Engineering Laboratory for Multi Flue Gas Pollution Control Technology and Equipment, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Changdong Liu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, National Engineering Laboratory for Multi Flue Gas Pollution Control Technology and Equipment, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Jianjun Chen
- State Key Joint Laboratory of Environment Simulation and Pollution Control, National Engineering Laboratory for Multi Flue Gas Pollution Control Technology and Equipment, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Junhua Li
- State Key Joint Laboratory of Environment Simulation and Pollution Control, National Engineering Laboratory for Multi Flue Gas Pollution Control Technology and Equipment, School of Environment, Tsinghua University, Beijing 100084, PR China
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26
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Alkattan HN, Kjellman U, Selimovic N, Alomrani A, Alghamdi AA. Deactivation of left ventricular assist device (LVAD) after recovery of cardiac function: A case report. J Card Surg 2021; 36:2974-2978. [PMID: 33955018 DOI: 10.1111/jocs.15609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 03/05/2021] [Accepted: 04/18/2021] [Indexed: 11/28/2022]
Abstract
Recovery of heart function during support with a durable left ventricular assist device (LVAD) is uncommon. There are few reports of cases that address eliminating the LVAD without the need for a heart transplant. Radical surgical removal of the LVAD may distort the left ventricular cavity and thus affect its function, in addition to the associated risks of the operation. Innovative ways to deactivate the LVAD, relying mainly on vascular plugs implanting in the outflow graft, have been used. Few reports have shown the success of this method. In this case report, we review the story of a young patient with advanced heart failure who underwent LVAD implantation. After six months, there was a dramatic improvement of heart function that enabled successful deactivation of the device.
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Affiliation(s)
- Hani N Alkattan
- Department of Cardiac Sciences, Ministry of the National Guard-Health Affairs, Riyadh, Saudi Arabia.,King Abdullah International Medical Research Centre, Riyadh, Saudi Arabia.,King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Ulf Kjellman
- Department of Cardiac Sciences, Ministry of the National Guard-Health Affairs, Riyadh, Saudi Arabia.,King Abdullah International Medical Research Centre, Riyadh, Saudi Arabia.,King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Nedim Selimovic
- Department of Cardiac Sciences, Ministry of the National Guard-Health Affairs, Riyadh, Saudi Arabia.,King Abdullah International Medical Research Centre, Riyadh, Saudi Arabia.,King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Ahmed Alomrani
- Department of Cardiac Sciences, Ministry of the National Guard-Health Affairs, Riyadh, Saudi Arabia.,King Abdullah International Medical Research Centre, Riyadh, Saudi Arabia.,King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Abdullah A Alghamdi
- Department of Cardiac Sciences, Ministry of the National Guard-Health Affairs, Riyadh, Saudi Arabia.,King Abdullah International Medical Research Centre, Riyadh, Saudi Arabia.,King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
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27
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Zou G, Xu J, Zhou S, Liu J, Su ZH, Zou Q, Gao JH. Functional MRI of arousals in nonrapid eye movement sleep. Sleep 2021; 43:5573984. [PMID: 31555827 DOI: 10.1093/sleep/zsz218] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 07/26/2019] [Indexed: 11/13/2022] Open
Abstract
Arousals commonly occur during human sleep and have been associated with several sleep disorders. Arousals are characterized as an abrupt electroencephalography (EEG) frequency change to higher frequencies during sleep. However, the human brain regions involved in arousal are not yet clear. Simultaneous EEG and functional magnetic resonance imaging (fMRI) data were recorded during the early portion of the sleep period in healthy young adults. Arousals were identified based on the EEG data, and fMRI signal changes associated with 83 arousals from 19 subjects were analyzed. Subcortical regions, including the midbrain, thalamus, basal ganglia, and cerebellum, were activated with arousal. Cortices, including the temporal gyrus, occipital gyrus, and frontal gyrus, were deactivated with arousal. The activations associated with arousal in the subcortical regions were consistent with previous findings of subcortical involvement in behavioral arousal and consciousness. Cortical deactivations may serve as a mechanism to direct incoming sensory stimuli to specific brain regions, thereby monitoring environmental perturbations during sleep.
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Affiliation(s)
- Guangyuan Zou
- Beijing City Key Lab for Medical Physics and Engineering, Institution of Heavy Ion Physics, School of Physics, Peking University, Beijing, China.,Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Jing Xu
- Laboratory of Applied Brain and Cognitive Sciences, College of International Business, Shanghai International Studies University, Shanghai, China
| | - Shuqin Zhou
- Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.,Department of Biomedical Engineering, College of Engineering, Peking University, Beijing, China
| | - Jiayi Liu
- Beijing City Key Lab for Medical Physics and Engineering, Institution of Heavy Ion Physics, School of Physics, Peking University, Beijing, China.,Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Zi Hui Su
- Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.,Nuffield Department of Clinical Neurosciences, Oxford University, Oxford, United Kingdom
| | - Qihong Zou
- Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Jia-Hong Gao
- Beijing City Key Lab for Medical Physics and Engineering, Institution of Heavy Ion Physics, School of Physics, Peking University, Beijing, China.,Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.,McGovern Institute for Brain Research, Peking University, Beijing, China.,Shenzhen Institute of Neuroscience, Shenzhen, China
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28
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Abstract
Precise control of CRISPR-Cas9 would improve its safety and applicability. Controlled CRISPR inhibition is a promising approach but is complicated by separate inhibitor delivery, incomplete deactivation, and slow kinetics. To overcome these obstacles, we engineered photocleavable guide RNAs (pcRNAs) that endow Cas9 nucleases and base editors with a built-in mechanism for light-based deactivation. pcRNA enabled the fastest (<1 min) and most complete (<1% residual indels) approach for Cas9 deactivation. It also exhibited significantly enhanced specificity with wild-type Cas9. Time-resolved deactivation revealed that 12-36 h of Cas9 activity or 2-4 h of base editor activity was sufficient to achieve high editing efficiency. pcRNA is useful for studies of the cellular response to DNA damage by abolishing sustained cycles of damage and repair that would otherwise desynchronize response trajectories. Together, pcRNA expands the CRISPR toolbox for precision genome editing and studies of DNA damage and repair.
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Affiliation(s)
- Roger S Zou
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Yang Liu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Bin Wu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Taekjip Ha
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA; Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD 21205, USA; Department of Biophysics, Johns Hopkins University, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Baltimore, MD 21205, USA.
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29
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Diemant T, Bansmann J. CO Oxidation on Planar Au/TiO 2 Model Catalysts under Realistic Conditions: A Combined Kinetic and IR Study. Chemphyschem 2021; 22:542-552. [PMID: 33411392 PMCID: PMC8048944 DOI: 10.1002/cphc.202000960] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 01/04/2021] [Indexed: 11/24/2022]
Abstract
The oxidation of CO on planar Au/TiO2 model catalysts was investigated under pressure and temperature conditions similar to those for experiments with more realistic Au/TiO2 powder catalysts. The effects of a change of temperature, pressure, and gold coverage on the CO oxidation activity were studied. Additionally, the reasons for the deactivation of the catalysts were examined in long-term experiments. From kinetic measurements, the activation energy and the reaction order for the CO oxidation reaction were derived and a close correspondence with results of powder catalysts was found, although the overall turnover frequency (TOF) measured in our experiments was around one order of magnitude lower compared to results of powder catalysts under similar conditions. Furthermore, long-term experiments at 80 °C showed a decrease of the activity of the model catalysts after some hours. Simultaneous in-situ IR experiments revealed a decrease of the signal intensity of the CO vibration band, while the tendency for the build-up of side products (e. g. carbonates, carboxylates) of the CO oxidation reaction on the surface of the planar model catalysts was rather low.
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Affiliation(s)
- Thomas Diemant
- Institut für Oberflächenchemie und Katalyse, Universität UlmAlbert-Einstein-Allee 4789081UlmGermany
- Helmholtz Institute Ulm (HIU) Electrochemical Energy StorageHelmholtzstraße 1189081UlmGermany
| | - Joachim Bansmann
- Institut für Oberflächenchemie und Katalyse, Universität UlmAlbert-Einstein-Allee 4789081UlmGermany
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30
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Zhang H, Pan J, Zhou Q, Xia F. Nanometal Thermocatalysts: Transformations, Deactivation, and Mitigation. Small 2021; 17:e2005771. [PMID: 33458963 DOI: 10.1002/smll.202005771] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/16/2020] [Indexed: 06/12/2023]
Abstract
Nanometals have been proven to be efficient thermocatalysts in the last decades. Their enhanced catalytic activity and tunable functionalities make them intriguing candidates for a wide range of catalytic applications, such as gaseous reactions and compound synthesis/decomposition. On the other hand, the enhanced specific surface energy and reactivity of nanometals can lead to configuration transformation and thus catalytic deactivation during the synthesis and catalysis, which largely undermines the activity and service time, thereby calling for urgent research effort to understand the deactivating mechanisms and develop efficient mitigating methods. Herein, the recent progress in understanding the configuration transformation-induced catalytic deactivation within nanometals is reviewed. The major pathways of configuration transformations, and their kinetics controlled by the environmental factors are presented. The approaches toward mitigating the transformation-induced deactivation are also presented. Finally, a perspective on the future academic approaches toward in-depth understanding of the kinetics of the deactivation of nanometals is proposed.
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Affiliation(s)
- Hanlei Zhang
- Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, No. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, Hubei, 430078, P. R. China
| | - Jing Pan
- Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, No. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, Hubei, 430078, P. R. China
| | - Qitao Zhou
- Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, No. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, Hubei, 430078, P. R. China
| | - Fan Xia
- Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, No. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, Hubei, 430078, P. R. China
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31
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Nakazawa M, Suzuki T, Shiga T, Suzuki A, Hagiwara N. Deactivation of implantable cardioverter defibrillator in Japanese patients with end-stage heart failure. J Arrhythm 2021; 37:196-202. [PMID: 33664903 PMCID: PMC7896444 DOI: 10.1002/joa3.12465] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/17/2020] [Accepted: 11/03/2020] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Despite the effectiveness of implantable cardioverter defibrillators (ICDs) in the prevention of sudden cardiac death, shock therapy causes patients to experience pain and psychological distress, which contradicts the purpose of palliative care. It is difficult to predict the time course for heart failure (HF) patients, unlike that for cancer patients. The aim of this study was to evaluate the deactivation status of ICD therapy in Japanese patients with end-stage HF. METHODS We retrospectively studied 51 ICD patients who died due to worsening HF at Tokyo Women's Medical University Hospital from 2010 to 2019. The frequency of ICD therapy delivered before death and information about the discussion of deactivation and do not attempt resuscitation (DNAR) decisions were reviewed using medical charts. RESULTS Of 51 patients, 12 (24%) patients deactivated ICD therapy and seven patients underwent deactivation within 24 hours of a DNAR order. The median time from deactivation to death was 3 days (range, 0-56). Of 39 patients with DNAR orders, 27 (69%) did not undergo deactivation. A relatively high proportion of patients (n = 14, 27%) experienced ICD shocks within 1 month of death. The frequency of electrical storms within 1 month of death was also high (n = 12, 24%). CONCLUSIONS Our study showed that only one-fourth of Japanese patients with end-stage HF underwent deactivation of ICD therapy. A relatively high frequency of shock therapy was observed in the last month before death.
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Affiliation(s)
- Mayui Nakazawa
- Department of CardiologyTokyo Women's Medical UniversityTokyoJapan
| | - Tsuyoshi Suzuki
- Department of CardiologyTokyo Women's Medical UniversityTokyoJapan
| | - Tsuyoshi Shiga
- Department of CardiologyTokyo Women's Medical UniversityTokyoJapan
- Department of Clinical Pharmacology and TherapeuticsThe Jikei University School of MedicineTokyoJapan
| | - Atsushi Suzuki
- Department of CardiologyTokyo Women's Medical UniversityTokyoJapan
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32
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Tzourio-Mazoyer N, Labache L, Zago L, Hesling I, Mazoyer B. Neural support of manual preference revealed by BOLD variations during right and left finger-tapping in a sample of 287 healthy adults balanced for handedness. Laterality 2021; 26:398-420. [PMID: 33403938 DOI: 10.1080/1357650x.2020.1862142] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
We have identified the brain areas involved in Manual Preference (MP) in 143 left-handers (LH) and 144 right-handers (RH). First, we selected the pairs of homotopic regions of interest (hROIs) of the AICHA atlas with significant contralateral activation and asymmetry during the right hand and the left hand Finger-Tapping (FT) both in RH and LH. Thirteen hROIs were selected, including the primary and secondary sensorimotor and premotor cortices, thalamus, dorsal putamen, and cerebellar lobule IV. In both groups, contralateral activations and ipsilateral deactivations were seen, with stronger asymmetries when the preferred hand was used. Comparing with different models for the prediction of MP, we found that the differences in activity during preferred hand minus non-preferred hand movement in 11 contralateral and/or ipsilateral hROIS were best at explaining handedness distribution. Two different mechanisms were identified: 1. Stronger contralateral activity of cortical and cerebellar motor areas during right hand movement, seen in both groups but modulated by handedness; 2. Stronger deactivation in ipsilateral areas during dominant hand movement in both groups, LH here mirroring RH. The present study thus demonstrates that handedness neural support is complex and not simply based on a mirrored organization of hand motor areas.
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Affiliation(s)
- N Tzourio-Mazoyer
- Institut des Maladies Neurodégénératives, Université de Bordeaux, Bordeaux, France.,CNRS, Institut des Maladies Neurodégénératives, Bordeaux, France.,CEA, Institut des Maladies Neurodégénératives, Bordeaux, France
| | - L Labache
- Institut des Maladies Neurodégénératives, Université de Bordeaux, Bordeaux, France.,CNRS, Institut des Maladies Neurodégénératives, Bordeaux, France.,CEA, Institut des Maladies Neurodégénératives, Bordeaux, France.,Institut de Mathématiques de Bordeaux, Université de Bordeaux, Bordeaux, France.,Bordeaux INP, Institut de Mathématiques de Bordeaux, Bordeaux, France.,INRIA Bordeaux Sud-Ouest, Institut de Mathématiques de Bordeaux, Talence, France
| | - L Zago
- Institut des Maladies Neurodégénératives, Université de Bordeaux, Bordeaux, France.,CNRS, Institut des Maladies Neurodégénératives, Bordeaux, France.,CEA, Institut des Maladies Neurodégénératives, Bordeaux, France
| | - I Hesling
- Institut des Maladies Neurodégénératives, Université de Bordeaux, Bordeaux, France.,CNRS, Institut des Maladies Neurodégénératives, Bordeaux, France.,CEA, Institut des Maladies Neurodégénératives, Bordeaux, France
| | - B Mazoyer
- Institut des Maladies Neurodégénératives, Université de Bordeaux, Bordeaux, France.,CNRS, Institut des Maladies Neurodégénératives, Bordeaux, France.,CEA, Institut des Maladies Neurodégénératives, Bordeaux, France.,Institut des Maladies Neurodégénératives Clinique, Centre Hospitalier Universitaire, Bordeaux, France
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33
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Rupert M, Bhattacharya A, Stillerova VT, Jindrichova M, Mokdad A, Boué-Grabot E, Zemkova H. Role of Conserved Residues and F322 in the Extracellular Vestibule of the Rat P2X7 Receptor in Its Expression, Function and Dye Uptake Ability. Int J Mol Sci 2020; 21:ijms21228446. [PMID: 33182845 PMCID: PMC7696158 DOI: 10.3390/ijms21228446] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 10/30/2020] [Accepted: 11/05/2020] [Indexed: 12/17/2022] Open
Abstract
Activation of the P2X7 receptor results in the opening of a large pore that plays a role in immune responses, apoptosis, and many other physiological and pathological processes. Here, we investigated the role of conserved and unique residues in the extracellular vestibule connecting the agonist-binding domain with the transmembrane domain of rat P2X7 receptor. We found that all residues that are conserved among the P2X receptor subtypes respond to alanine mutagenesis with an inhibition (Y51, Q52, and G323) or a significant decrease (K49, G326, K327, and F328) of 2',3'-O-(benzoyl-4-benzoyl)-ATP (BzATP)-induced current and permeability to ethidium bromide, while the nonconserved residue (F322), which is also present in P2X4 receptor, responds with a 10-fold higher sensitivity to BzATP, much slower deactivation kinetics, and a higher propensity to form the large dye-permeable pore. We examined the membrane expression of conserved mutants and found that Y51, Q52, G323, and F328 play a role in the trafficking of the receptor to the plasma membrane, while K49 controls receptor responsiveness to agonists. Finally, we studied the importance of the physicochemical properties of these residues and observed that the K49R, F322Y, F322W, and F322L mutants significantly reversed the receptor function, indicating that positively charged and large hydrophobic residues are important at positions 49 and 322, respectively. These results show that clusters of conserved residues above the transmembrane domain 1 (K49-Y51-Q52) and transmembrane domain 2 (G326-K327-F328) are important for receptor structure, membrane expression, and channel gating and that the nonconserved residue (F322) at the top of the extracellular vestibule is involved in hydrophobic inter-subunit interaction which stabilizes the closed state of the P2X7 receptor channel.
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Affiliation(s)
- Marian Rupert
- Institute of Physiology, Czech Academy of Sciences, 14220 Prague, Czech Republic; (M.R.); (A.B.); (V.T.S.); (M.J.); (A.M.)
- 1st Faculty of Medicine, Charles University, 12108 Prague, Czech Republic
| | - Anirban Bhattacharya
- Institute of Physiology, Czech Academy of Sciences, 14220 Prague, Czech Republic; (M.R.); (A.B.); (V.T.S.); (M.J.); (A.M.)
| | - Vendula Tvrdonova Stillerova
- Institute of Physiology, Czech Academy of Sciences, 14220 Prague, Czech Republic; (M.R.); (A.B.); (V.T.S.); (M.J.); (A.M.)
| | - Marie Jindrichova
- Institute of Physiology, Czech Academy of Sciences, 14220 Prague, Czech Republic; (M.R.); (A.B.); (V.T.S.); (M.J.); (A.M.)
| | - Audrey Mokdad
- Institute of Physiology, Czech Academy of Sciences, 14220 Prague, Czech Republic; (M.R.); (A.B.); (V.T.S.); (M.J.); (A.M.)
- Institute des Maladies Neurodégénératives, University de Bordeaux, UMR 5293, F-33000 Bordeaux, France;
- Centre National de la Recherche Scientifique, UMR 5293, F-33000 Bordeaux, France
| | - Eric Boué-Grabot
- Institute des Maladies Neurodégénératives, University de Bordeaux, UMR 5293, F-33000 Bordeaux, France;
- Centre National de la Recherche Scientifique, UMR 5293, F-33000 Bordeaux, France
| | - Hana Zemkova
- Institute of Physiology, Czech Academy of Sciences, 14220 Prague, Czech Republic; (M.R.); (A.B.); (V.T.S.); (M.J.); (A.M.)
- Correspondence:
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Shi YP, Pang Z, Venkateshappa R, Gunawan M, Kemp J, Truong E, Chang C, Lin E, Shafaattalab S, Faizi S, Rayani K, Tibbits GF, Claydon VE, Claydon TW. The hERG channel activator, RPR260243, enhances protective IKr current early in the refractory period reducing arrhythmogenicity in zebrafish hearts. Am J Physiol Heart Circ Physiol 2020; 319:H251-H261. [PMID: 32559136 DOI: 10.1152/ajpheart.00038.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Human ether-à-go-go related gene (hERG) K+ channels are important in cardiac repolarization, and their dysfunction causes prolongation of the ventricular action potential, long QT syndrome, and arrhythmia. As such, approaches to augment hERG channel function, such as activator compounds, have been of significant interest due to their marked therapeutic potential. Activator compounds that hinder channel inactivation abbreviate action potential duration (APD) but carry risk of overcorrection leading to short QT syndrome. Enhanced risk by overcorrection of the APD may be tempered by activator-induced increased refractoriness; however, investigation of the cumulative effect of hERG activator compounds on the balance of these effects in whole organ systems is lacking. Here, we have investigated the antiarrhythmic capability of a hERG activator, RPR260243, which primarily augments channel function by slowing deactivation kinetics in ex vivo zebrafish whole hearts. We show that RPR260243 abbreviates the ventricular APD, reduces triangulation, and steepens the slope of the electrical restitution curve. In addition, RPR260243 increases the post-repolarization refractory period. We provide evidence that this latter effect arises from RPR260243-induced enhancement of hERG channel-protective currents flowing early in the refractory period. Finally, the cumulative effect of RPR260243 on arrhythmogenicity in whole organ zebrafish hearts is demonstrated by the restoration of normal rhythm in hearts presenting dofetilide-induced arrhythmia. These findings in a whole organ model demonstrate the antiarrhythmic benefit of hERG activator compounds that modify both APD and refractoriness. Furthermore, our results demonstrate that targeted slowing of hERG channel deactivation and enhancement of protective currents may provide an effective antiarrhythmic approach.NEW & NOTEWORTHY hERG channel dysfunction causes long QT syndrome and arrhythmia. Activator compounds have been of significant interest due to their therapeutic potential. We used the whole organ zebrafish heart model to demonstrate the antiarrhythmic benefit of the hERG activator, RPR260243. The activator abbreviated APD and increased refractoriness, the combined effect of which rescued induced ventricular arrhythmia. Our findings show that the targeted slowing of hERG channel deactivation and enhancement of protective currents caused by the RPR260243 activator may provide an effective antiarrhythmic approach.
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Affiliation(s)
- Yu Patrick Shi
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, British Columbia, Canada
| | - ZhaoKai Pang
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, British Columbia, Canada
| | - Ravichandra Venkateshappa
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, British Columbia, Canada
| | - Marvin Gunawan
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, British Columbia, Canada
| | - Jacob Kemp
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, British Columbia, Canada
| | - Elson Truong
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, British Columbia, Canada
| | - Cherlene Chang
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, British Columbia, Canada
| | - Eric Lin
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, British Columbia, Canada
| | - Sanam Shafaattalab
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, British Columbia, Canada
| | - Shoaib Faizi
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, British Columbia, Canada
| | - Kaveh Rayani
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, British Columbia, Canada
| | - Glen F Tibbits
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, British Columbia, Canada
| | - Victoria E Claydon
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, British Columbia, Canada
| | - Thomas W Claydon
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, British Columbia, Canada
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35
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Morgan BA, Manser M, Jeyanathan M, Xing Z, Cranston ED, Thompson MR. Effect of Shear Stresses on Adenovirus Activity and Aggregation during Atomization To Produce Thermally Stable Vaccines by Spray Drying. ACS Biomater Sci Eng 2020; 6:4304-4313. [PMID: 33463328 DOI: 10.1021/acsbiomaterials.0c00317] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Considering the substantive potential benefits of thermally stable dry powder vaccines to public health, causes for inactivation of their sensitive viral vectors during preparation require intensive study. The focus of this work was atomization of suspensions containing encapsulating excipients and a human type 5 adenovirus, involving a detailed investigation of shear stresses in the nozzle of a spray dryer. Samples were sprayed at 25 °C into falcon tubes and immediately evaluated for viral activity by in vitro testing, minimizing the confounding of thermal effects on the deactivation of the virus, although interfacial stresses could not be decoupled from shear stresses. Despite the expectations of only virus deactivation with ever-increasing shear stresses in the spray nozzle, some conditions were found to show better activity than the positive control, leading to investigations of viral aggregation. It was found that the adenovirus experienced minor aggregation when mixed with the excipient solutions, which was reversed by subjecting samples to moderate shear conditions in the spray nozzle. At very high shear rates, the activity diminished again because of damage to the viral capsid fibers, which also led to the production of new aggregates after atomization. Despite these findings, activity losses caused by shear were small compared to the overall spray drying process loss. However, formulation composition, solution viscosity, and process conditions should be considered carefully for optimization because of their impact on aggregation. This is the first known report comparing shear, aggregation, and biological activity loss during the atomization step of spray drying viral vaccines.
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Affiliation(s)
- Blair A Morgan
- Department of Chemical Engineering, McMaster University, Hamilton, L8S 4L7 Ontario, Canada
| | - Myla Manser
- Department of Chemical Engineering, McMaster University, Hamilton, L8S 4L7 Ontario, Canada
| | - Mangalakumari Jeyanathan
- McMaster Immunology Research Centre and Department of Pathology and Molecular Medicine, McMaster University, Hamilton, L8S 4L7 Ontario, Canada
| | - Zhou Xing
- McMaster Immunology Research Centre and Department of Pathology and Molecular Medicine, McMaster University, Hamilton, L8S 4L7 Ontario, Canada
| | - Emily D Cranston
- Department of Chemical Engineering, McMaster University, Hamilton, L8S 4L7 Ontario, Canada.,Department of Wood Science, University of British Columbia, 2424 Main Mall, Vancouver, V6T 1Z4 British Columbia, Canada.,Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, V6T 1Z3 British Columbia, Canada
| | - Michael R Thompson
- Department of Chemical Engineering, McMaster University, Hamilton, L8S 4L7 Ontario, Canada
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36
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Steins A, van Mackelenbergh MG, van der Zalm AP, Klaassen R, Serrels B, Goris SG, Kocher HM, Waasdorp C, de Jong JH, Tekin C, Besselink MG, Busch OR, van de Vijver MJ, Verheij J, Dijk F, van Tienhoven G, Wilmink JW, Medema JP, van Laarhoven HWM, Bijlsma MF. High-grade mesenchymal pancreatic ductal adenocarcinoma drives stromal deactivation through CSF-1. EMBO Rep 2020; 21:e48780. [PMID: 32173982 PMCID: PMC7202203 DOI: 10.15252/embr.201948780] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 02/11/2020] [Accepted: 02/18/2020] [Indexed: 01/05/2023] Open
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is characterized by an abundance of stroma. Multiple molecular classification efforts have identified a mesenchymal tumor subtype that is consistently characterized by high-grade growth and poor clinical outcome. The relation between PDAC stroma and tumor subtypes is still unclear. Here, we aimed to identify how PDAC cells instruct the main cellular component of stroma, the pancreatic stellate cells (PSCs). We found in primary tissue that high-grade PDAC had reduced collagen deposition compared to low-grade PDAC. Xenografts and organotypic co-cultures established from mesenchymal-like PDAC cells featured reduced collagen and activated PSC content. Medium transfer experiments using a large set of PDAC cell lines revealed that mesenchymal-like PDAC cells consistently downregulated ACTA2 and COL1A1 expression in PSCs and reduced proliferation. We identified colony-stimulating factor 1 as the mesenchymal PDAC-derived ligand that deactivates PSCs, and inhibition of its receptor CSF1R was able to counteract this effect. In conclusion, high-grade PDAC features stroma that is low in collagen and activated PSC content, and targeting CSF1R offers direct options to maintain a tumor-restricting microenvironment.
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Affiliation(s)
- Anne Steins
- Laboratory for Experimental Oncology and RadiobiologyCenter for Experimental and Molecular MedicineCancer Center AmsterdamAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
- Department of Medical OncologyCancer Center AmsterdamAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
- Oncode InstituteAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Madelaine G van Mackelenbergh
- Laboratory for Experimental Oncology and RadiobiologyCenter for Experimental and Molecular MedicineCancer Center AmsterdamAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
- Department of Medical OncologyCancer Center AmsterdamAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
- Oncode InstituteAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Amber P van der Zalm
- Laboratory for Experimental Oncology and RadiobiologyCenter for Experimental and Molecular MedicineCancer Center AmsterdamAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
- Department of Medical OncologyCancer Center AmsterdamAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
- Oncode InstituteAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Remy Klaassen
- Laboratory for Experimental Oncology and RadiobiologyCenter for Experimental and Molecular MedicineCancer Center AmsterdamAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
- Department of Medical OncologyCancer Center AmsterdamAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Bryan Serrels
- Wolfson Wohl Cancer Research CentreGlasgow Precision Oncology LaboratoryUniversity of GlasgowGlasgowUK
| | - Sandrine G Goris
- Laboratory for Experimental Oncology and RadiobiologyCenter for Experimental and Molecular MedicineCancer Center AmsterdamAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
- Department of Medical OncologyCancer Center AmsterdamAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Hemant M Kocher
- Centre for Tumor BiologyBarts Cancer InstituteQueen Mary University of LondonLondonUK
| | - Cynthia Waasdorp
- Laboratory for Experimental Oncology and RadiobiologyCenter for Experimental and Molecular MedicineCancer Center AmsterdamAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
- Oncode InstituteAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Joan H de Jong
- Laboratory for Experimental Oncology and RadiobiologyCenter for Experimental and Molecular MedicineCancer Center AmsterdamAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
- Oncode InstituteAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Cansu Tekin
- Laboratory for Experimental Oncology and RadiobiologyCenter for Experimental and Molecular MedicineCancer Center AmsterdamAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
- Oncode InstituteAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Marc G Besselink
- Department of SurgeryCancer Center AmsterdamAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Olivier R Busch
- Department of SurgeryCancer Center AmsterdamAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Marc J van de Vijver
- Department of PathologyAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Joanne Verheij
- Department of PathologyAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Frederike Dijk
- Department of PathologyAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Geertjan van Tienhoven
- Department of Radiation OncologyAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Johanna W Wilmink
- Department of Medical OncologyCancer Center AmsterdamAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Jan Paul Medema
- Laboratory for Experimental Oncology and RadiobiologyCenter for Experimental and Molecular MedicineCancer Center AmsterdamAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
- Oncode InstituteAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Hanneke WM van Laarhoven
- Department of Medical OncologyCancer Center AmsterdamAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Maarten F Bijlsma
- Laboratory for Experimental Oncology and RadiobiologyCenter for Experimental and Molecular MedicineCancer Center AmsterdamAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
- Oncode InstituteAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
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Sakaguchi T, Kono Y, Itaba N, Morimoto M, Isomoto H, Shiota G. Identification of a Novel Deactivating Small-Molecule Compound for Fibrogenic Hepatic Stellate Cells. Yonago Acta Med 2020; 63:79-87. [PMID: 32158337 DOI: 10.33160/yam.2020.02.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 02/06/2020] [Indexed: 01/07/2023]
Abstract
Background Liver fibrosis progresses to decompensated liver cirrhosis, for which medical needs remain unmet. We recently developed IC-2, a small-molecule compound that suppresses Wnt/β-catenin signaling, and found that IC-2 also suppresses liver fibrosis. In this study, we performed three-step screening of newly synthesized IC-2 derivatives to identify other small-molecule compounds that suppress liver fibrosis. Methods The screening system consisted of three steps: a cell viability assay, a transcription factor 4 (TCF4) reporter assay, and induction of α-smooth muscle actin (α-SMA) and collagen 1α1 (Col1A1) expression in response to each compound. Screening using human LX-2 hepatic stellate cells (HSCs) was performed to target HSCs, which are the driver cells of liver fibrosis. Results In the first step, since 9b and 9b-CONH2 at 100 μM did not have any effects on cell viability, they were omitted in the next screening. Additionally, the conditions that led to > 40% inhibition of the controls were also excluded in subsequent screening. The second step was performed under 31 conditions for 19 small-molecule compounds. Sixteen small-molecule compounds caused significant reduction of TCF4 activity relative to that of 0.1% DMSO. Of the 16 compounds, the 10 showing the greatest suppression of TCF4 activity were selected for the third step. Expressions of mRNA for α-SMA and Col1A1 were significantly reduced by seven and three small-molecule compounds, respectively. The greatest reductions in the α-SMA and Col1A1 mRNA expressions were observed in the cells treated with IC-2-F. Protein expressions of α-SMA and Col1A1 caused by IC-2-F were also comparable to those caused by IC-2. Conclusion IC-2-F was identified as a novel deactivating small-molecule compound for HSCs in vitro. These data suggest that IC-2-F is a promising medicine for liver fibrosis.
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Affiliation(s)
- Takuki Sakaguchi
- Department of Genetic Medicine and Regenerative Therapeutics, Graduate School of Medical Sciences, Tottori University, Yonago 683-8503, Japan.,Division of Medicine and Clinical Science, Department of Multidisciplinary Internal Medicine, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8503, Japan
| | - Yohei Kono
- Department of Genetic Medicine and Regenerative Therapeutics, Graduate School of Medical Sciences, Tottori University, Yonago 683-8503, Japan
| | - Noriko Itaba
- Department of Genetic Medicine and Regenerative Therapeutics, Graduate School of Medical Sciences, Tottori University, Yonago 683-8503, Japan
| | - Minoru Morimoto
- Research Initiative Center, Tottori University, Tottori 680-8550, Japan
| | - Hajime Isomoto
- Division of Medicine and Clinical Science, Department of Multidisciplinary Internal Medicine, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8503, Japan
| | - Goshi Shiota
- Department of Genetic Medicine and Regenerative Therapeutics, Graduate School of Medical Sciences, Tottori University, Yonago 683-8503, Japan
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Abstract
BACKGROUND In Canada, cardiovascular disease is the second most common cause of death. A subset of these patients will require a cardiovascular implantable electronic device (CIED). An estimated 200 000 Canadians are living with a CIED. CIEDs can improve life and prevent premature death. However, when patients reach the end of their lives, they can pose a challenge. An example of which is a painful shock delivered from an implantable cardioverter defibrillator (ICD) for an arrhythmia in a dying patient. Receiving a shock at the end of life (EOL) is unacceptable in an age when we aim to ease the suffering of the dying and allow for a comfortable death. METHODS As a quality standard of practice, all clinicians are expected to engage in EOL conversations in patients requiring CIED deactivation. Due to the potential discomfort of an ICD shock, specific conversations about deactivation of an ICD are encouraged. A process improvement approach was developed by our hospital that included an advance care planning simulation lab, electronic documentation and a standardized comfort measures order set that includes addressing the need for ICD deactivation at EOL. RESULTS EOL conversations are complex. Health care providers have been equally challenged to have conversations about ICD deactivation. Standardization of the process of ICD deactivation ensures an approach to EOL which respects the individuality of patients and promotes quality dying. CONCLUSION Our hospital is committed to assisting clinicians to provide quality care by improving conversations about EOL care. On the basis of a synthesis of existing literature, we describe the importance of and the ideal process for having EOL conversations in patients about ICD deactivation at the EOL.
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Affiliation(s)
- Suzette Turner
- Schulich Heart Program, Sunnybrook Health Sciences Center, University of Toronto, Toronto, Ontario, Canada.,Lawrence Bloomberg Faculty of Nursing, Toronto, Ontario, Canada
| | - Sarah Torabi
- Division of Palliative Care, Sunnybrook Health Sciences Center, University of Toronto, Toronto, Ontario, Canada.,Department of Family and Community Medicine, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Kalli Stilos
- Lawrence Bloomberg Faculty of Nursing, Toronto, Ontario, Canada.,Division of Palliative Care, Sunnybrook Health Sciences Center, University of Toronto, Toronto, Ontario, Canada
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Abstract
The hERG (human-ether-à-go-go-related gene) channel underlies the rapid delayed rectifier current, Ikr, in the heart, which is essential for normal cardiac electrical activity and rhythm. Slow deactivation is one of the hallmark features of the unusual gating characteristics of hERG channels, and plays a crucial role in providing a robust current that aids repolarization of the cardiac action potential. As such, there is significant interest in elucidating the underlying mechanistic determinants of slow hERG channel deactivation. Recent work has shown that the hERG channel S4 voltage sensor is stabilized following activation in a process termed relaxation. Voltage sensor relaxation results in energetic separation of the activation and deactivation pathways, producing a hysteresis, which modulates the kinetics of deactivation gating. Despite widespread observation of relaxation behaviour in other voltage-gated K+ channels, such as Shaker, Kv1.2 and Kv3.1, as well as the voltage-sensing phosphatase Ci-VSP, the relationship between stabilization of the activated voltage sensor by the open pore and voltage sensor relaxation in the control of deactivation has only recently begun to be explored. In this review, we discuss present knowledge and questions raised related to the voltage sensor relaxation mechanism in hERG channels and compare structure-function aspects of relaxation with those observed in related ion channels. We focus discussion, in particular, on the mechanism of coupling between voltage sensor relaxation and deactivation gating to highlight the insight that these studies provide into the control of hERG channel deactivation gating during their physiological functioning.
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Affiliation(s)
- Yu Patrick Shi
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Samrat Thouta
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Thomas W Claydon
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
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Bai Z, Fong KNK, Zhang J, Hu Z. Cortical mapping of mirror visual feedback training for unilateral upper extremity: A functional near-infrared spectroscopy study. Brain Behav 2020; 10:e01489. [PMID: 31805613 PMCID: PMC6955835 DOI: 10.1002/brb3.1489] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/28/2019] [Accepted: 11/13/2019] [Indexed: 11/23/2022] Open
Abstract
INTRODUCTION Mirror therapy has been shown to be effective in promoting hemiplegic arm recovery in patients with stroke or unilateral cerebral palsy. This study aimed to explore the cortical mapping associated with mirror therapy in a group of healthy adults by using functional near-infrared spectroscopy. METHODS Fifteen right-handed healthy adults were recruited by means of convenience sampling. A 2 × 2 factorial design was used: movement complexity with two levels-task-based (T) and movement-based (M), and visual direction with two levels-mirror visual feedback task (MT) and covered mirror with normal visual feedback task (NoT) as the control, constituting four conditions, namely TMT, MMT, TNoT, and MNoT. The regions of interest were the sensorimotor cortex (SMC), the supplementary motor area (SMA), the superior parietal cortex (SPL), and the precuneus in both the contralateral and ipsilateral hemispheres. RESULTS Our findings showed that in the ipsilateral hemisphere, MT induced a higher activation in the SMA and SPL than NoT. With regard to the activation of the ipsilateral SMC, only one channel was found showing superior effects of MT compared with NoT. In addition, MT can strengthen the functional connectivity between the SMC and SMA. In the contralateral hemisphere, both movement complexity and visual direction showed significant main effects in the SMC, while only movement complexity showed a significant main effect in the SMA and SPL. The precuneus of both sides was deactivated and showed no significant difference among the four conditions. CONCLUSIONS Our experiment implies that the modest activation of ipsilateral SMC during MT is likely to be associated with the enhanced activity of ipsilateral SMA and that the precuneus may not be an essential component of the MT-related neural network.
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Affiliation(s)
- Zhongfei Bai
- Department of Rehabilitation SciencesThe Hong Kong Polytechnic UniversityKowloonHong Kong SAR
- Department of Occupational TherapyShanghai Yangzhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center)ShanghaiChina
- Department of Rehabilitation SciencesTongji University School of MedicineShanghaiChina
| | - Kenneth N. K. Fong
- Department of Rehabilitation SciencesThe Hong Kong Polytechnic UniversityKowloonHong Kong SAR
| | - Jiaqi Zhang
- Department of Rehabilitation SciencesThe Hong Kong Polytechnic UniversityKowloonHong Kong SAR
| | - Zhishan Hu
- Faculty of Health SciencesUniversity of MacauMacau SAR
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Wang Y, Pu Y, Yuan D, Luo J, Li F, Xiao F, Zhao N. Selective Oxidation of Glycerol to Dihydroxyacetone over Au/Cu xZr 1-xO y Catalysts in Base-Free Conditions. ACS Appl Mater Interfaces 2019; 11:44058-44068. [PMID: 31684717 DOI: 10.1021/acsami.9b12886] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In this paper, a series of Cu-Zr mixed metal oxide-supported Au catalysts were prepared by deposition-precipitation and evaluated for selective oxidation of glycerol to dihydroxyacetone (DHA) in base-free conditions. The best catalytic performance was obtained with DHA selectivity of up to 95% and yield of 70% in 4 h, 50 °C and PO2 = 0.2 MPa over the Au/Cu0.95Zr0.05 and Au/Cu0.9Zr0.1 catalysts. Combined with the characterization results of Brunauer-Emmett-Teller, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and CO2 temperature programmed desorption, it was proposed that the content of Au0, the size of Au, and the basicity of the catalyst affected the glycerol conversion and DHA selectivity. After the catalyst was recycled four times, the glycerol conversion decreased by about 14% which might result from the carbon deposition or the byproduct adsorption and the agglomeration of Au particle.
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Affiliation(s)
- Yanxia Wang
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry , Chinese Academy of Sciences , Taoyuan South Road 27 , Taiyuan 030001 , Shanxi , PR China
- University of Chinese Academy of Sciences , Yuquan Road 19 , Beijing 100049 , Beijing , PR China
| | - Yanfeng Pu
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry , Chinese Academy of Sciences , Taoyuan South Road 27 , Taiyuan 030001 , Shanxi , PR China
| | - Danping Yuan
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry , Chinese Academy of Sciences , Taoyuan South Road 27 , Taiyuan 030001 , Shanxi , PR China
- University of Chinese Academy of Sciences , Yuquan Road 19 , Beijing 100049 , Beijing , PR China
| | - Jing Luo
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry , Chinese Academy of Sciences , Taoyuan South Road 27 , Taiyuan 030001 , Shanxi , PR China
- University of Chinese Academy of Sciences , Yuquan Road 19 , Beijing 100049 , Beijing , PR China
| | - Feng Li
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry , Chinese Academy of Sciences , Taoyuan South Road 27 , Taiyuan 030001 , Shanxi , PR China
| | - Fukui Xiao
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry , Chinese Academy of Sciences , Taoyuan South Road 27 , Taiyuan 030001 , Shanxi , PR China
| | - Ning Zhao
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry , Chinese Academy of Sciences , Taoyuan South Road 27 , Taiyuan 030001 , Shanxi , PR China
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Li YJ, Duan GF, Sun JH, Wu D, Ye C, Zang YY, Chen GQ, Shi YY, Wang J, Zhang W, Shi YS. Neto proteins regulate gating of the kainate-type glutamate receptor GluK2 through two binding sites. J Biol Chem 2019; 294:17889-17902. [PMID: 31628192 PMCID: PMC6879349 DOI: 10.1074/jbc.ra119.008631] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 10/15/2019] [Indexed: 12/14/2022] Open
Abstract
The neuropilin and tolloid-like (Neto) proteins Neto1 and Neto2 are auxiliary subunits of kainate-type glutamate receptors (KARs) that regulate KAR trafficking and gating. However, how Netos bind and regulate the biophysical functions of KARs remains unclear. Here, we found that the N-terminal domain (NTD) of glutamate receptor ionotropic kainate 2 (GluK2) binds the first complement C1r/C1s-Uegf-BMP (CUB) domain of Neto proteins (i.e. NTD-CUB1 interaction) and that the core of GluK2 (GluK2ΔNTD) binds Netos through domains other than CUB1s (core-Neto interaction). Using electrophysiological analysis in HEK293T cells, we examined the effects of these interactions on GluK2 gating, including deactivation, desensitization, and recovery from desensitization. We found that NTD deletion does not affect GluK2 fast gating kinetics, the desensitization, and the deactivation. We also observed that Neto1 and Neto2 differentially regulate GluK2 fast gating kinetics, which largely rely on the NTD-CUB1 interactions. NTD removal facilitated GluK2 recovery from desensitization, indicating that the NTD stabilizes the GluK2 desensitization state. Co-expression with Neto1 or Neto2 also accelerated GluK2 recovery from desensitization, which fully relied on the NTD-CUB1 interactions. Moreover, we demonstrate that the NTD-CUB1 interaction involves electric attraction between positively charged residues in the GluK2_NTD and negatively charged ones in the CUB1 domains. Neutralization of these charges eliminated the regulatory effects of the NTD-CUB1 interaction on GluK2 gating. We conclude that KARs bind Netos through at least two sites and that the NTD-CUB1 interaction critically regulates Neto-mediated GluK2 gating.
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Affiliation(s)
- Yan-Jun Li
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, and Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing 210032, China
| | - Gui-Fang Duan
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, and Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing 210032, China
| | - Jia-Hui Sun
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, and Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing 210032, China
| | - Dan Wu
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, and Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing 210032, China
| | - Chang Ye
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, and Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing 210032, China
| | - Yan-Yu Zang
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, and Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing 210032, China
| | - Gui-Quan Chen
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, and Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing 210032, China
- Institute for Brain Sciences, Nanjing University, Nanjing 210032, China
| | - Yong-Yun Shi
- Department of Orthopaedics, Luhe People's Hospital Affiliated to Yangzhou University, Nanjing 211500, China
| | - Jun Wang
- Ministry of Education Key Laboratory of Modern Toxicology, Department of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Wei Zhang
- Institute of Chinese Integrative Medicine, Hebei Medical University, Shijiazhuang 050017, China
| | - Yun Stone Shi
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, and Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing 210032, China
- Institute for Brain Sciences, Nanjing University, Nanjing 210032, China
- Chemistry and Biomedicine Innovation Center, Nanjing University, Nanjing 210032, China
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Bairagya MD, Bujol RJ, Elgrishi N. Fighting Deactivation: Classical and Emerging Strategies for Efficient Stabilization of Molecular Electrocatalysts. Chemistry 2019; 26:3991-4000. [PMID: 31710129 DOI: 10.1002/chem.201904499] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Indexed: 11/12/2022]
Abstract
Development of highly active molecular electrocatalysts for fuel-forming reactions has relied heavily on understanding mechanistic aspects of the electrochemical transformations. Careful fine-tuning of the ligand environment oriented mechanistic pathways towards higher activity and optimal product distribution for several catalysts. Unfortunately, many catalysts deactivate in bulk electrolysis conditions, diminishing the impact of the plethora of highly tuned molecular electrocatalytic systems. This Minireview covers classical and emerging methods developed to circumvent catalyst deactivation and degradation, with an emphasis on successes with molecular electrocatalysts.
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Affiliation(s)
- Monojit Das Bairagya
- Department of Chemistry, Louisiana State University, 232 Choppin Hall, Baton Rouge, LA, 70803, USA
| | - Ryan J Bujol
- Department of Chemistry, Louisiana State University, 232 Choppin Hall, Baton Rouge, LA, 70803, USA
| | - Noémie Elgrishi
- Department of Chemistry, Louisiana State University, 232 Choppin Hall, Baton Rouge, LA, 70803, USA
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Filez M, Redekop EA, Dendooven J, Ramachandran RK, Solano E, Olsbye U, Weckhuysen BM, Galvita VV, Poelman H, Detavernier C, Marin GB. Formation and Functioning of Bimetallic Nanocatalysts: The Power of X-ray Probes. Angew Chem Int Ed Engl 2019; 58:13220-13230. [PMID: 30934165 PMCID: PMC6771619 DOI: 10.1002/anie.201902859] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Indexed: 01/08/2023]
Abstract
Bimetallic nanocatalysts are key enablers of current chemical technologies, including car exhaust converters and fuel cells, and play a crucial role in industry to promote a wide range of chemical reactions. However, owing to significant characterization challenges, insights in the dynamic phenomena that shape and change the working state of the catalyst await further refinement. Herein, we discuss the atomic-scale processes leading to mono- and bimetallic nanoparticle formation and highlight the dynamics and kinetics of lifetime changes in bimetallic catalysts with showcase examples for Pt-based systems. We discuss how in situ and operando X-ray spectroscopy, scattering, and diffraction can be used as a complementary toolbox to interrogate the working principles of today's and tomorrow's bimetallic nanocatalysts.
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Affiliation(s)
- Matthias Filez
- Inorganic Chemistry and Catalysis group, Utrecht University, Universiteitsweg 99, 3584CG, Utrecht, The Netherlands
| | - Evgeniy A Redekop
- Centre for Materials Science and Nanotechnology (SMN), Department of Chemistry, University of Oslo, P.O box 1126 Blindern, C0318, Oslo, Norway
| | - Jolien Dendooven
- Conformal Coatings of Nanomaterials group, Ghent University, Krijgslaan 281/S1, 9000, Ghent, Belgium
| | - Ranjith K Ramachandran
- Conformal Coatings of Nanomaterials group, Ghent University, Krijgslaan 281/S1, 9000, Ghent, Belgium
| | - Eduardo Solano
- Conformal Coatings of Nanomaterials group, Ghent University, Krijgslaan 281/S1, 9000, Ghent, Belgium.,NCD-SWEET beamline, ALBA synchrotron light source, Carrer de la Llum 2-26, 08290, Cerdanyola del Vallès, Barcelona, Spain
| | - Unni Olsbye
- Centre for Materials Science and Nanotechnology (SMN), Department of Chemistry, University of Oslo, P.O box 1126 Blindern, C0318, Oslo, Norway
| | - Bert M Weckhuysen
- Inorganic Chemistry and Catalysis group, Utrecht University, Universiteitsweg 99, 3584CG, Utrecht, The Netherlands
| | - Vladimir V Galvita
- Laboratory for Chemical Technology, Ghent University, Technologiepark 125, 9052, Ghent, Belgium
| | - Hilde Poelman
- Laboratory for Chemical Technology, Ghent University, Technologiepark 125, 9052, Ghent, Belgium
| | - Christophe Detavernier
- Conformal Coatings of Nanomaterials group, Ghent University, Krijgslaan 281/S1, 9000, Ghent, Belgium
| | - Guy B Marin
- Laboratory for Chemical Technology, Ghent University, Technologiepark 125, 9052, Ghent, Belgium
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Dbira S, Bensalah N, Ahmad MI, Bedoui A. Electrochemical Oxidation/Disinfection of Urine Wastewaters with Different Anode Materials. Materials (Basel) 2019; 12:E1254. [PMID: 30995773 DOI: 10.3390/ma12081254] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 04/10/2019] [Accepted: 04/12/2019] [Indexed: 11/26/2022]
Abstract
In the present work, electrochemical technology was used simultaneously for the deactivation of microorganisms and the destruction of micro-pollutants contained in synthetic urine wastewaters. Microorganisms (E. coli) were added to synthetic urine wastewaters to mimic secondary treated sewage wastewaters. Different anode materials were employed including boron-doped diamond (BDD), dimensionally stable anode (DSA: IrO2 and RuO2) and platinum (Pt). The results showed that for the different anode materials, a complete deactivation of E. coli microorganisms at low applied electric charge (1.34 Ah dm−3) was obtained. The complete deactivation of microorganisms in wastewater seems to be directly related to active chlorine and oxygen species electrochemically produced at the surface of the anode material. Complete depletion of COD and TOC can be attained during electrolyses with BDD anode after the consumption of specific electric charges of 4.0 and 8.0 Ah dm−3, respectively. Higher specific electric charges (>25 Ah dm−3) were consumed to removal completely COD and about 75% of TOC during electrolyses with DSA anodes (IrO2 and RuO2). However, the electrolysis using Pt anode can partially remove and even after the consumption of high specific electric charges (>40 Ah dm−3) COD and TOC did not exceed 50 and 25%, respectively. Active chlorine species including hypochlorite ions and chloramines formed during electrolysis contribute not only to deactivate microorganisms but also to degrade organics compounds. High conversion yields of organic nitrogen into nitrates and ammonium were achieved during electrolysis BDD and DSA anodes. The results have confirmed that BDD anode is more efficient than with IrO2, RuO2 and Pt electrodes in terms of COD and TOC removals. However, higher amounts of perchlorates were measured at the end of the electrolysis using BDD anode.
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Kosinov N, Uslamin EA, Meng L, Parastaev A, Liu Y, Hensen EJM. Reversible Nature of Coke Formation on Mo/ZSM-5 Methane Dehydroaromatization Catalysts. Angew Chem Int Ed Engl 2019; 58:7068-7072. [PMID: 30900346 PMCID: PMC6563702 DOI: 10.1002/anie.201902730] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Indexed: 11/18/2022]
Abstract
Non‐oxidative dehydroaromatization of methane over Mo/ZSM‐5 zeolite catalysts is a promising reaction for the direct conversion of abundant natural gas into liquid aromatics. Rapid coking deactivation hinders the practical implementation of this technology. Herein, we show that catalyst productivity can be improved by nearly an order of magnitude by raising the reaction pressure to 15 bar. The beneficial effect of pressure was found for different Mo/ZSM‐5 catalysts and a wide range of reaction temperatures and space velocities. High‐pressure operando X‐ray absorption spectroscopy demonstrated that the structure of the active Mo‐phase was not affected by operation at elevated pressure. Isotope labeling experiments, supported by mass‐spectrometry and 13C nuclear magnetic resonance spectroscopy, indicated the reversible nature of coke formation. The improved performance can be attributed to faster coke hydrogenation at increased pressure, overall resulting in a lower coke selectivity and better utilization of the zeolite micropore space.
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Affiliation(s)
- Nikolay Kosinov
- Laboratory of Inorganic Materials and Catalysis, Eindhoven University of Technology, PO Box 513, 5600, MB, Eindhoven, The Netherlands
| | - Evgeny A Uslamin
- Laboratory of Inorganic Materials and Catalysis, Eindhoven University of Technology, PO Box 513, 5600, MB, Eindhoven, The Netherlands
| | - Lingqian Meng
- Laboratory of Inorganic Materials and Catalysis, Eindhoven University of Technology, PO Box 513, 5600, MB, Eindhoven, The Netherlands
| | - Alexander Parastaev
- Laboratory of Inorganic Materials and Catalysis, Eindhoven University of Technology, PO Box 513, 5600, MB, Eindhoven, The Netherlands
| | - Yujie Liu
- Laboratory of Inorganic Materials and Catalysis, Eindhoven University of Technology, PO Box 513, 5600, MB, Eindhoven, The Netherlands
| | - Emiel J M Hensen
- Laboratory of Inorganic Materials and Catalysis, Eindhoven University of Technology, PO Box 513, 5600, MB, Eindhoven, The Netherlands
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Liu L, Ye XP, Katryniok B, Capron M, Paul S, Dumeignil F. Extending Catalyst Life in Glycerol-to-Acrolein Conversion Using Non-thermal Plasma. Front Chem 2019; 7:108. [PMID: 30881953 PMCID: PMC6405481 DOI: 10.3389/fchem.2019.00108] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 02/11/2019] [Indexed: 11/18/2022] Open
Abstract
Booming biodiesel production worldwide demands valorization of its byproduct of glycerol. Acrolein, an important intermediate chemical, can be produced by gas-phase glycerol dehydration catalyzed by solid acids. Because catalysts that lead to high acrolein selectivity usually deactivate rapidly due to the formation of coke that blocks the active sites on their surface, one major challenge of this method is how to extend the service life of the catalyst. Silica-supported silicotungstic acid (HSiW-Si) is a good example of such a catalyst that shows good activity in glycerol dehydration to acrolein initially, but deactivates quickly. In this study, HSiW-Si was selected to probe the potential of using non-thermal plasma with oxygen-containing gas as the discharge gas (NTP-O2) to solve the catalyst deactivation problem. NTP-O2 was found to be effective in coke removal and catalyst regeneration at low temperatures without damaging the Keggin structure of the HSiW-Si catalyst.
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Affiliation(s)
- Lu Liu
- Department of Biosystems Engineering and Soil Science, The University of Tennessee, Knoxville, TN, United States
| | - Xiaofei Philip Ye
- Department of Biosystems Engineering and Soil Science, The University of Tennessee, Knoxville, TN, United States
| | - Benjamin Katryniok
- Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, Lille, France
| | - Mickaël Capron
- Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, Lille, France
| | - Sébastien Paul
- Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, Lille, France
| | - Franck Dumeignil
- Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, Lille, France
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48
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Cavanagh CE, Rosman L, Lampert R, Chui PW, Johnston ML, Burg MM. Planning ahead: End-of-life decisions for patients with defibrillators. Pacing Clin Electrophysiol 2019; 42:548-552. [PMID: 30779352 DOI: 10.1111/pace.13641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 12/13/2018] [Accepted: 02/13/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Casey E Cavanagh
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut.,Pain, Research, Informatics, Multimorbidities, and Education (PRIME) Center, VA Connecticut Healthcare System, West Haven, Connecticut
| | - Lindsey Rosman
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut.,Pain, Research, Informatics, Multimorbidities, and Education (PRIME) Center, VA Connecticut Healthcare System, West Haven, Connecticut
| | - Rachel Lampert
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
| | - Philip W Chui
- Pain, Research, Informatics, Multimorbidities, and Education (PRIME) Center, VA Connecticut Healthcare System, West Haven, Connecticut.,Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
| | | | - Matthew M Burg
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut.,Department of Anesthesiology, Yale School of Medicine, New Haven, Connecticut
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Abstract
The default network (DN) is a brain network with correlated activities spanning frontal, parietal, and temporal cortical lobes. The DN activates for high-level cognition tasks and deactivates when subjects are actively engaged in perceptual tasks. Despite numerous observations, the role of DN deactivation remains unclear. Using computational neuroimaging applied to a large dataset of the Human Connectome Project (HCP) and to two individual subjects scanned over many repeated runs, we demonstrate that the DN selectively deactivates as a function of the position of a visual stimulus. That is, we show that spatial vision is encoded within the DN by means of deactivation relative to baseline. Our results suggest that the DN functions as a set of high-level visual regions, opening up the possibility of using vision-science tools to understand its putative function in cognition and perception.
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Affiliation(s)
- Martin Szinte
- Department of Cognitive Psychology, Vrije Universiteit Amsterdam, Amsterdam 1081BT, Netherlands.,Spinoza Centre for Neuroimaging, Royal Dutch Academy of Sciences, Amsterdam 1105BK, Netherlands
| | - Tomas Knapen
- Department of Cognitive Psychology, Vrije Universiteit Amsterdam, Amsterdam 1081BT, Netherlands.,Spinoza Centre for Neuroimaging, Royal Dutch Academy of Sciences, Amsterdam 1105BK, Netherlands
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50
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Farooqui AA, Manly T. Hierarchical Cognition Causes Task-Related Deactivations but Not Just in Default Mode Regions. eNeuro 2018; 5:ENEURO. [PMID: 30627658 DOI: 10.1523/ENEURO.0008-18.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 09/25/2018] [Accepted: 10/14/2018] [Indexed: 12/24/2022] Open
Abstract
The well-known deactivation of the default mode network (DMN) during external tasks is usually thought to reflect the suppression of internally directed mental activity during external attention. In three experiments with human participants we organized sequences of task events identical in their attentional and control demands into larger task episodes. We found that DMN deactivation across such sequential events was never constant, but was maximum at the beginning of the episode, then decreased gradually across the episode, reaching baseline towards episode completion, with the final event of the episode eliciting an activation. Crucially, this pattern of activity was not limited to a fixed set of DMN regions but, across experiments, was shown by a variable set of regions expected to be uninvolved in processing the ongoing task. This change in deactivation across sequential but identical events showed that the deactivation cannot be related to attentional/control demands which were constant across the episode, instead, it has to be related to some episode related load that was maximal at the beginning and then decreased gradually as parts of the episode got executed. We argue that this load resulted from cognitive programs through which the entire episode was hierarchically executed as one unit. At the beginning of task episodes, programs related to their entire duration is assembled, causing maximal deactivation. As execution proceeds, elements within the program related to the completed parts of the episode dismantle, thereby decreasing the program load and causing a decrease in deactivation.
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