1
|
Sun X, Wang P, Davey K, Zheng Y, Qiao SZ. Mild Methane Electrochemical Oxidation Boosted via Plasma Pre-Activation. Small 2023; 19:e2303428. [PMID: 37434078 DOI: 10.1002/smll.202303428] [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: 04/24/2023] [Revised: 06/19/2023] [Indexed: 07/13/2023]
Abstract
Obtaining partial methane oxidation reaction (MOR) with various oxygenates via a mild electrochemical method is practically difficult because of activation of stable C─H bond and consequent reaction pathway regulation. Here, a real-time tandem MOR with cascaded plasma and electrocatalysis to activate and convert the methane (CH4 ) synergistically is reported for the first time. Boosted CH4 conversion is demonstrated toward value-added products including, alcohols, carboxylates, and ketone via use of commercial Pd-based electrocatalysts. Compared with hash industrial processes, a mild condition, that is, anode potential < 1.0 V versus RHE (reversible hydrogen electrode) is used that mitigates overoxidation of oxygenates and obviates competing reaction(s). One evidence that Pd(II) sites and surface adsorbed hydroxyls are important in facilitating activated-CH4 species conversion, and establish a reaction mechanism for conversion(s) that involves coupling reactions between adsorbed hydroxyls, carbon monoxide and C1 /C2 alkyls. One conclude that pre-activation is important in boosting electrochemical partial MOR under mild conditions and will be of benefit in the development of sustainable CH4 conversion technology.
Collapse
Affiliation(s)
- Xiaogang Sun
- School of Chemical Engineering, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Pengtang Wang
- School of Chemical Engineering, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Kenneth Davey
- School of Chemical Engineering, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Yao Zheng
- School of Chemical Engineering, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Shi-Zhang Qiao
- School of Chemical Engineering, The University of Adelaide, Adelaide, SA, 5005, Australia
| |
Collapse
|
2
|
Yu H, Wang J, Mao M, Song Q, Zhang C, Fong DTP, Sun W. Muscle co-contraction and pre-activation in knee and ankle joint during a typical Tai Chi brush-knee twist-step. Res Sports Med 2023; 31:628-637. [PMID: 34957881 DOI: 10.1080/15438627.2021.2020788] [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: 10/08/2021] [Accepted: 12/15/2021] [Indexed: 10/19/2022]
Abstract
This study aimed to investigate the co-contraction and pre-activation of agonistic and antagonistic muscles in experienced Tai Chi (TC) practitioners during normal walking (NW) and brush-knee twist-step (BKTS). The electromyographic activities of rectus femoris, biceps femoris, and tibialis anterior and lateral gastrocnemius muscles were collected during BKTS and NW in 28 TC practitioners. The pre-activation of knee and ankle joints before initial landing of left foot, and the co-contraction of knee and ankle joint in double-stance phase I (DSI), single-stance phase (SS), double-stance phase II (DSII), and swing phase (SW) were calculated during BKTS and NW. Ankle co-contraction significantly increased during DSI and SS in BKTS movements than compared with that in NW. For DSI and SW, SS and DSII, and DSII and SW, a significant difference was found in BKTS. The pre-activation of knee joint significantly decreased in BKTS and NW. This study indicated greater ankle joint muscle co-contraction in DSI and SS of stance phase and lower knee joint muscle co-contraction and pre-activation than in NW in BKTS movement. In addition, greater ankle joint muscle co-contraction was observed in the DSI, SS, and DSII of stance phase than those of swing phase in BKTS movement.
Collapse
Affiliation(s)
- Hao Yu
- College of Sports and Health, Shandong Sport University, Jinan, China
| | - JiangNa Wang
- College of Sports and Health, Shandong Sport University, Jinan, China
| | - Min Mao
- School of Nursing and Rehabilitation Shandong University, Jinan, China
| | - QiPeng Song
- College of Sports and Health, Shandong Sport University, Jinan, China
| | - Cui Zhang
- Lab of Biomechanics, Shandong Institute of Sport Science, Jinan, China
| | - Daniel T P Fong
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Wei Sun
- College of Sports and Health, Shandong Sport University, Jinan, China
| |
Collapse
|
3
|
Fukutani A, Isaka T, Herzog W. Evidence for Muscle Cell-Based Mechanisms of Enhanced Performance in Stretch-Shortening Cycle in Skeletal Muscle. Front Physiol 2021; 11:609553. [PMID: 33488399 PMCID: PMC7820781 DOI: 10.3389/fphys.2020.609553] [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: 09/23/2020] [Accepted: 11/30/2020] [Indexed: 12/30/2022] Open
Abstract
Force attained during concentric contraction (active shortening) is transiently enhanced following eccentric contraction (active stretch) in skeletal muscle. This phenomenon is called stretch-shortening cycle (SSC) effect. Since many human movements contain combinations of eccentric and concentric contractions, a better understanding of the mechanisms underlying the SSC effect would be useful for improving physical performance, optimizing human movement efficiency, and providing an understanding of fundamental mechanism of muscle force control. Currently, the most common mechanisms proposed for the SSC effect are (i) stretch-reflex activation and (ii) storage of energy in tendons. However, abundant SSC effects have been observed in single fiber preparations where stretch-reflex activation is eliminated and storage of energy in tendons is minimal at best. Therefore, it seems prudent to hypothesize that factor(s) other than stretch-reflex activation and energy storage in tendons contribute to the SSC effect. In this brief review, we focus on possible candidate mechanisms for the SSC effect, that is, pre-activation, cross-bridge kinetics, and residual force enhancement (RFE) obtained in experimental preparations that exclude/control the influence of stretch-reflex activation and energy storage in tendons. Recent evidence supports the contribution of these factors to the mechanism of SSCs, and suggests that the extent of their contribution varies depending on the contractile conditions. Evidence for and against alternative mechanisms are introduced and discussed, and unresolved problems are mentioned for inspiring future studies in this field of research.
Collapse
Affiliation(s)
- Atsuki Fukutani
- Faculty of Sport and Health Science, Ritsumeikan University, Kusatsu, Japan
- Department of Physiology and Pharmacology, Karolinska Institutet, Solna, Sweden
| | - Tadao Isaka
- Faculty of Sport and Health Science, Ritsumeikan University, Kusatsu, Japan
| | - Walter Herzog
- Faculty of Kinesiology, The University of Calgary, Calgary, AB, Canada
| |
Collapse
|
4
|
Di Giminiani R, Giovannelli A, Capuano L, Izzicupo P, Di Blasio A, Masedu F. Neuromuscular Strategies in Stretch-Shortening Exercises with Increasing Drop Heights: The Role of Muscle Coactivation in Leg Stiffness and Power Propulsion. Int J Environ Res Public Health 2020; 17:ijerph17228647. [PMID: 33233323 PMCID: PMC7700220 DOI: 10.3390/ijerph17228647] [Citation(s) in RCA: 2] [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] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 11/11/2020] [Accepted: 11/19/2020] [Indexed: 05/24/2023]
Abstract
When applying drop jump exercises, knowing the magnitude of the stimulus is fundamental to stabilize the leg joints and to generate movements with the highest power. The effects of different drop heights on leg muscles coactivation, leg stiffness and power propulsion were investigated in fifteen sport science students. Drop jumps from heights of 20, 30, 40, 50, and 60 cm in a random order were performed on a force platform. During each drop jump, the ground reaction force, knee angle displacement, and synchronized surface-electromyography root-mean-square (sEMGRMS) activity (vastus lateralis, VL; vastus medialis, VM; rectus femoris, RF; biceps femoris, BF; tibialis anterior, TA and lateral gastrocnemius, LG) were recorded. The coactivation in the pre-contact phase, between VL and BF, VM and BF as well as RF and BF, was dependent on the drop height (p < 0.01; effect size (ES) ranged from 0.45 to 0.90). Leg stiffness was dependent on the drop height (p < 0.001; ES = 0.27-0.28) and was modulated by the coactivation of VM-BF (p = 0.034) and RF-BF (p = 0.046) during the braking phase. Power propulsion was also dependent on the drop height (p < 0.001; ES = 0.34); however, it was primarily modulated by the coactivation of LG-TA during the braking phase (p = 0.002). The coactivation of thigh muscles explains leg stiffness adjustments at different drop heights. On the contrary, the coactivation of shank muscles is mostly responsible for the power propulsion.
Collapse
Affiliation(s)
- Riccardo Di Giminiani
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy; (A.G.); (L.C.); (F.M.)
| | - Aldo Giovannelli
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy; (A.G.); (L.C.); (F.M.)
| | - Lorenzo Capuano
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy; (A.G.); (L.C.); (F.M.)
| | - Pascal Izzicupo
- Department of Medicine and Aging Sciences, University “G. D’Annunzio” of Chieti-Pescara, 66100 Chieti, Italy; (P.I.); (A.D.B.)
| | - Andrea Di Blasio
- Department of Medicine and Aging Sciences, University “G. D’Annunzio” of Chieti-Pescara, 66100 Chieti, Italy; (P.I.); (A.D.B.)
| | - Francesco Masedu
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy; (A.G.); (L.C.); (F.M.)
| |
Collapse
|
5
|
Grill A, Kiouptsi K, Karwot C, Jurk K, Reinhardt C. Evaluation of blood collection methods and anticoagulants for platelet function analyses on C57BL/6J laboratory mice. Platelets 2019; 31:981-988. [PMID: 31814487 DOI: 10.1080/09537104.2019.1701185] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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: 12/23/2022]
Abstract
The exploration of thrombotic mechanisms relies on the application of blood collection methods from laboratory mice with a minimal pre-activation of platelets and the clotting system. So far, very little is known on how the blood collection method and the anticoagulant used influence pre-activation of mouse platelets and coagulation. To determine the most suitable blood collection method, we systematically compared blood collection by heart puncture, Vena cava puncture, and puncture of the retro-orbital vein plexus and the use of citrate, heparin, and EDTA as frequently used anticoagulants with regard to platelet activation and whole blood clotting parameters. The activation of platelet-rich plasma diluted in Tyrode's buffer was analyzed by flow cytometry, analyzing the exposure of P-selectin and activated integrin αIIbβ3. Clotting of whole blood was profiled by thrombelastometry. Puncture of the retro-orbital vein plexus by plastic capillaries is not superior in terms of blood volume and platelet pre-activation, whereas heart puncture and Vena cava puncture resulted in similarly high blood volumes. Cardiac puncture and Vena cava puncture did not result in pre-activated platelets with citrate as an anticoagulant, but the use of EDTA resulted in increased levels of integrin αIIbβ3 activation. Puncture of the retro-orbital vein plexus by plastic capillaries resulted in increased platelet integrin αIIbβ3 activation, which could be prevented by soaking with citrate or coating with heparin. Further, activation of coagulation in citrated whole blood by puncture of the retro-orbital vein plexus using a blunt plastic capillary was observed by thromboelastometry. The use of citrate is the optimal anticoagulant in mouse platelet assays. Blood collections from the heart or Vena cava represent reliable alternatives to retro-orbital puncture of the vein plexus to avoid pre-activation of platelets and coagulation.
Collapse
Affiliation(s)
- Alexandra Grill
- Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Johannes Gutenberg University of Mainz , Mainz, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site RheinMain , Mainz, Germany
| | - Klytaimnistra Kiouptsi
- Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Johannes Gutenberg University of Mainz , Mainz, Germany
| | - Cornelia Karwot
- Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Johannes Gutenberg University of Mainz , Mainz, Germany
| | - Kerstin Jurk
- Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Johannes Gutenberg University of Mainz , Mainz, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site RheinMain , Mainz, Germany
| | - Christoph Reinhardt
- Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Johannes Gutenberg University of Mainz , Mainz, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site RheinMain , Mainz, Germany
| |
Collapse
|
6
|
Najafi A, van de Locht M, Schuldt M, Schönleitner P, van Willigenburg M, Bollen I, Goebel M, Ottenheijm CAC, van der Velden J, Helmes M, Kuster DWD. End-diastolic force pre-activates cardiomyocytes and determines contractile force: role of titin and calcium. J Physiol 2019; 597:4521-4531. [PMID: 31314138 PMCID: PMC6852589 DOI: 10.1113/jp277985] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [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: 03/11/2019] [Accepted: 07/10/2019] [Indexed: 12/22/2022] Open
Abstract
Titin functions as a molecular spring, and cardiomyocytes are able, through splicing, to control the length of titin. We hypothesized that together with diastolic [Ca2+], titin‐based stretch pre‐activates cardiomyocytes during diastole and is a major determinant of force production in the subsequent contraction. Through this mechanism titin would play an important role in active force development and length‐dependent activation. Mutations in the splicing factor RNA binding motif protein 20 (RBM20) result in expression of large, highly compliant titin isoforms. We measured single cardiomyocyte work loops that mimic the cardiac cycle in wild‐type (WT) and heterozygous (HET) RBM20‐deficient rats. In addition, we studied the role of diastolic [Ca2+] in membrane‐permeabilized WT and HET cardiomyocytes. Intact cardiomyocytes isolated from HET left ventricles were unable to produce normal levels of work (55% of WT) at low pacing frequencies, but this difference disappeared at high pacing frequencies. Length‐dependent activation (force–sarcomere length relationship) was blunted in HET cardiomyocytes, but the force–end‐diastolic force relationship was not different between HET and WT cardiomyocytes. To delineate the effects of diastolic [Ca2+] and titin pre‐activation on force generation, measurements were performed in detergent‐permeabilized cardiomyocytes. Cardiac twitches were simulated by transiently exposing permeabilized cardiomyocytes to 2 µm Ca2+. Increasing diastolic [Ca2+] from 1 to 80 nm increased force development twofold in WT. Higher diastolic [Ca2+] was needed in HET. These findings are consistent with our hypothesis that pre‐activation increases active force development. Highly compliant titin allows cells to function at higher diastolic [Ca2+].
Collapse
Affiliation(s)
- Aref Najafi
- Amsterdam UMC, Vrije Universiteit Amsterdam, Physiology, Amsterdam Cardiovascular Sciences, de Boelelaan 1117, 1081 HZ, Amsterdam, the Netherlands.,Netherlands Heart Institute, PO box 19258, 3501 DG, Utrecht, the Netherlands
| | - Martijn van de Locht
- Amsterdam UMC, Vrije Universiteit Amsterdam, Physiology, Amsterdam Cardiovascular Sciences, de Boelelaan 1117, 1081 HZ, Amsterdam, the Netherlands
| | - Maike Schuldt
- Amsterdam UMC, Vrije Universiteit Amsterdam, Physiology, Amsterdam Cardiovascular Sciences, de Boelelaan 1117, 1081 HZ, Amsterdam, the Netherlands
| | | | | | - Ilse Bollen
- Amsterdam UMC, Vrije Universiteit Amsterdam, Physiology, Amsterdam Cardiovascular Sciences, de Boelelaan 1117, 1081 HZ, Amsterdam, the Netherlands
| | - Max Goebel
- Amsterdam UMC, Vrije Universiteit Amsterdam, Physiology, Amsterdam Cardiovascular Sciences, de Boelelaan 1117, 1081 HZ, Amsterdam, the Netherlands
| | - Coen A C Ottenheijm
- Amsterdam UMC, Vrije Universiteit Amsterdam, Physiology, Amsterdam Cardiovascular Sciences, de Boelelaan 1117, 1081 HZ, Amsterdam, the Netherlands
| | - Jolanda van der Velden
- Amsterdam UMC, Vrije Universiteit Amsterdam, Physiology, Amsterdam Cardiovascular Sciences, de Boelelaan 1117, 1081 HZ, Amsterdam, the Netherlands.,Netherlands Heart Institute, PO box 19258, 3501 DG, Utrecht, the Netherlands
| | - Michiel Helmes
- Amsterdam UMC, Vrije Universiteit Amsterdam, Physiology, Amsterdam Cardiovascular Sciences, de Boelelaan 1117, 1081 HZ, Amsterdam, the Netherlands.,Ionoptix, de Boelelaan 1108, 1081 HV, Amsterdam, the Netherlands.,CytoCypher, de Boelelaan 1108, 1081 HV, Amsterdam, the Netherlands
| | - Diederik W D Kuster
- Amsterdam UMC, Vrije Universiteit Amsterdam, Physiology, Amsterdam Cardiovascular Sciences, de Boelelaan 1117, 1081 HZ, Amsterdam, the Netherlands
| |
Collapse
|
7
|
Cuenca-Fernández F, López-Contreras G, Mourão L, de Jesus K, de Jesus K, Zacca R, Vilas-Boas JP, Fernandes RJ, Arellano R. Eccentric flywheel post-activation potentiation influences swimming start performance kinetics. J Sports Sci 2018; 37:443-451. [PMID: 30070620 DOI: 10.1080/02640414.2018.1505183] [Citation(s) in RCA: 23] [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: 01/24/2023]
Abstract
This study aimed to assess the effects of post-activation potentiation in the strength related variables of a kick start. Thirteen competitive swimmers performed three kick starts after a standardized warm up (denoted USUAL) and another after inducing post-activation through five isotonic repetitions on an eccentric flywheel (denoted PAP). A T-test was used to quantify differences between USUAL and PAP warm up. The best trial of each subject achieved by natural conditions (denoted PEAK) was compared with data obtained after PAP. An instrumented starting block with independent triaxial force plates, collected the strength variables related with the impulse at take off. Improvements in the vertical components of force were observed after PAP compared with USUAL, meanwhile no differences were detected on the horizontal components of it. The velocity at take off was higher after PAP compared with USUAL (4.32 ± 0.88 vs 3.93 ± 0.60 m*s-1; p = 0.02). No differences in force or velocity were detected comparing PAP with PEAK (4.13 ± 0.62 m*s-1, p = 0.11). The PAP warm-up increased vertical force and it was transferred to a higher resultant velocity at take-off. This improvement would equal the best result possible obtained in natural conditions after some trials.
Collapse
Affiliation(s)
- Francisco Cuenca-Fernández
- a Physical Activity and Sports Department. Faculty of Sport Sciences , University of Granada , Granada , ( Spain
| | - Gracia López-Contreras
- a Physical Activity and Sports Department. Faculty of Sport Sciences , University of Granada , Granada , ( Spain
| | - Luis Mourão
- b Centre of Research, Education, Innovation and Intervention in Sport, Faculty f Sport , University of Porto , Porto , Portugal.,c Porto Biomechanics Laboratory , University of Porto , Porto , Portugal
| | - Karla de Jesus
- b Centre of Research, Education, Innovation and Intervention in Sport, Faculty f Sport , University of Porto , Porto , Portugal.,c Porto Biomechanics Laboratory , University of Porto , Porto , Portugal.,d Ministry of Education of Brazil , CAPES Foundation , Brasília , Brazil.,e Human Performance Studies Laboratory, Faculty of Physical Education and Physiotherapy , Federal University of Amazon , Manaus, Amazon , Brazil
| | - Kelly de Jesus
- b Centre of Research, Education, Innovation and Intervention in Sport, Faculty f Sport , University of Porto , Porto , Portugal.,c Porto Biomechanics Laboratory , University of Porto , Porto , Portugal.,d Ministry of Education of Brazil , CAPES Foundation , Brasília , Brazil.,e Human Performance Studies Laboratory, Faculty of Physical Education and Physiotherapy , Federal University of Amazon , Manaus, Amazon , Brazil
| | - Rodrigo Zacca
- b Centre of Research, Education, Innovation and Intervention in Sport, Faculty f Sport , University of Porto , Porto , Portugal.,c Porto Biomechanics Laboratory , University of Porto , Porto , Portugal.,d Ministry of Education of Brazil , CAPES Foundation , Brasília , Brazil
| | - J Paulo Vilas-Boas
- b Centre of Research, Education, Innovation and Intervention in Sport, Faculty f Sport , University of Porto , Porto , Portugal.,c Porto Biomechanics Laboratory , University of Porto , Porto , Portugal
| | - Ricardo J Fernandes
- b Centre of Research, Education, Innovation and Intervention in Sport, Faculty f Sport , University of Porto , Porto , Portugal.,c Porto Biomechanics Laboratory , University of Porto , Porto , Portugal
| | - Raúl Arellano
- a Physical Activity and Sports Department. Faculty of Sport Sciences , University of Granada , Granada , ( Spain
| |
Collapse
|
8
|
Abstract
Due to the wide presence of carbohydrates in nature and their crucial roles in numerous important biological processes, oligosaccharides have attracted a lot of attention in synthetic organic chemistry community. Many innovative synthetic methods have been developed for oligosaccharide synthesis, among which the pre-activation based glycosylation is particularly noteworthy. Traditionally, glycosylation reactions are carried out when the glycosyl donor and the acceptor are both present when the promoter is added. In comparison, the pre-activation based glycosylation is unique, where the glycosyl donor is activated by the promoter in the absence of the acceptor. Upon complete donor activation, the acceptor is added to the reaction mixture enabling glycosylation. The key step in any oligosaccharide synthesis is the stereoselective formation of the glycosidic bond. As donor activation and acceptor glycosylation are temporally separated, pre-activation based glycosylation can bestow unique stereochemical control. This review systematically discusses factors impacting the stereochemical outcome of a pre-activation based glycosylation reaction including substituents on the glycosyl donor, reaction solvent, and additives. Applications of pre-activation based stereoselective glycosylation in assembly of complex oligosaccharides are also discussed.
Collapse
Affiliation(s)
- Bo Yang
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, MI 48824 USA
| | - Weizhun Yang
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, MI 48824 USA
| | - Sherif Ramadan
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, MI 48824 USA
- Chemistry Department, Faculty of Science, Benha University, Benha, Qaliobiya 13518, Egypt
| | - Xuefei Huang
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, MI 48824 USA
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI 48824 USA
- Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI 48824 USA
| |
Collapse
|
9
|
Söderström P, Horne M, Frid J, Roll M. Pre-Activation Negativity (PrAN) in Brain Potentials to Unfolding Words. Front Hum Neurosci 2016; 10:512. [PMID: 27777558 PMCID: PMC5056166 DOI: 10.3389/fnhum.2016.00512] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [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: 07/20/2016] [Accepted: 09/27/2016] [Indexed: 11/25/2022] Open
Abstract
We describe an event-related potential (ERP) effect termed the “pre-activation negativity” (PrAN), which is proposed to index the degree of pre-activation of upcoming word-internal morphemes in speech processing. Using lexical competition measures based on word-initial speech fragments (WIFs), as well as statistical analyses of ERP data from three experiments, it is shown that the PrAN is sensitive to lexical competition and that it reflects the degree of predictive certainty: the negativity is larger when there are fewer upcoming lexical competitors.
Collapse
Affiliation(s)
- Pelle Söderström
- Centre for Languages and Literature, Lund University Lund, Sweden
| | - Merle Horne
- Centre for Languages and Literature, Lund University Lund, Sweden
| | - Johan Frid
- Humanities Laboratory, Lund University Lund, Sweden
| | - Mikael Roll
- Centre for Languages and Literature, Lund University Lund, Sweden
| |
Collapse
|
10
|
Ylostalo JH, Bartosh TJ, Tiblow A, Prockop DJ. Unique characteristics of human mesenchymal stromal/progenitor cells pre-activated in 3-dimensional cultures under different conditions. Cytotherapy 2014; 16:1486-1500. [PMID: 25231893 DOI: 10.1016/j.jcyt.2014.07.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [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: 06/24/2014] [Revised: 07/28/2014] [Accepted: 07/28/2014] [Indexed: 02/06/2023]
Abstract
BACKGROUND AIMS Human mesenchymal stromal cells (MSCs) are being used in clinical trials, but the best protocol to prepare the cells for administration to patients remains unclear. We previously demonstrated that MSCs could be pre-activated to express therapeutic factors by culturing the cells in 3 dimensions (3D). We compared the activation of MSCs in 3D in fetal bovine serum containing medium and in multiple xeno-free media formulations. METHODS MSC aggregation and sphere formation was studied with the use of hanging drop cultures with medium containing fetal bovine serum or with various commercially available stem cell media with or without human serum albumin (HSA). Activation of MSCs was studied with the use of gene expression and protein secretion measurements and with functional studies with the use of macrophages and cancer cells. RESULTS MSCs did not condense into tight spheroids and express a full complement of therapeutic genes in α-minimum essential medium or several commercial stem-cell media. However, we identified a chemically defined xeno-free media, which, when supplemented with HSA from blood or recombinant HSA, resulted in compact spheres with high cell viability, together with high expression of anti-inflammatory (prostaglandin E2, TSG-6 TNF-alpha induced gene/protein 6) and anti-cancer molecules (TRAIL TNF-related apoptosis-inducing ligand, interleukin-24). Furthermore, spheres cultured in this medium showed potent anti-inflammatory effects in a lipopolysaccharide-stimulated macrophage system and suppressed the growth of prostate cancer cells by promoting cell-cycle arrest and cell death. CONCLUSIONS We demonstrated that cell activation in 3D depends critically on the culture medium. The conditions developed in the present study for 3D culture of MSCs should be useful in further research on MSCs and their potential therapeutic applications.
Collapse
Affiliation(s)
- Joni H Ylostalo
- Institute for Regenerative Medicine, Texas A&M University Health Science Center College of Medicine at Scott & White, Temple, TX, USA
| | - Thomas J Bartosh
- Institute for Regenerative Medicine, Texas A&M University Health Science Center College of Medicine at Scott & White, Temple, TX, USA
| | - April Tiblow
- Institute for Regenerative Medicine, Texas A&M University Health Science Center College of Medicine at Scott & White, Temple, TX, USA
| | - Darwin J Prockop
- Institute for Regenerative Medicine, Texas A&M University Health Science Center College of Medicine at Scott & White, Temple, TX, USA.
| |
Collapse
|