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Iesalnieks M, Vanags M, Alsiņa LL, Eglītis R, Grīnberga L, Sherrell PC, Šutka A. Efficient Decoupled Electrolytic Water Splitting in Acid through Pseudocapacitive TiO 2. Adv Sci (Weinh) 2024:e2401261. [PMID: 38742588 DOI: 10.1002/advs.202401261] [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: 02/02/2024] [Revised: 04/30/2024] [Indexed: 05/16/2024]
Abstract
Water electrolysis remains a key component in the societal transition to green energy. Membrane electrolyzers are the state-of-the-art technology for water electrolysis, relying on 80 °C operation in highly alkaline electrolytes, which is undesirable for many of the myriad end-use cases for electrolytic water splitting. Herein, an alternative water electrolysis process, decoupled electrolysis, is described which performed in mild acidic conditions with excellent efficiencies. Decoupled electrolysis sequentially performs the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER), at the same catalyst. Here, H+ ions generated from the OER are stored through pseudocapacitive (redox) charge storage, and released to drive the HER. Here, decoupled electrolysis is demonstrated using cheap, abundant, TiO2 for the first time. To achieve decoupled acid electrolysis, ultra-small anatase TiO2 particles (4.5 nm diameter) are prepared. These ultra-small TiO2 particles supported on a carbon felt electrode show a highly electrochemical surface area with a capacitance of 375 F g-1. When these electrodes are tested for decoupled water splitting an overall energy efficiency of 52.4% is observed, with excellent stability over 3000 cycles of testing. This technology can provide a viable alternative to membrane electrolyzers-eliminating the need for highly alkaline electrolytes and elevated temperatures.
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Affiliation(s)
- Mairis Iesalnieks
- Institute of Materials and Surface Engineering, Faculty of Natural Sciences and Technology, Riga Technical University, P. Valdena Street 3/7, Riga, LV-1048, Latvia
| | - Mārtiņš Vanags
- Institute of Materials and Surface Engineering, Faculty of Natural Sciences and Technology, Riga Technical University, P. Valdena Street 3/7, Riga, LV-1048, Latvia
| | - Linda Laima Alsiņa
- Institute of Materials and Surface Engineering, Faculty of Natural Sciences and Technology, Riga Technical University, P. Valdena Street 3/7, Riga, LV-1048, Latvia
| | - Raivis Eglītis
- Institute of Materials and Surface Engineering, Faculty of Natural Sciences and Technology, Riga Technical University, P. Valdena Street 3/7, Riga, LV-1048, Latvia
| | - Līga Grīnberga
- Institute of Solid State Physics, University of Latvia, Riga, LV-1063, Latvia
| | - Peter C Sherrell
- Applied Chemistry & Environmental Science, School of Science, RMIT University, 124 La Trobe St, Melbourne, 3000, Australia
| | - Andris Šutka
- Institute of Materials and Surface Engineering, Faculty of Natural Sciences and Technology, Riga Technical University, P. Valdena Street 3/7, Riga, LV-1048, Latvia
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2
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Liepinsh E, Zvejniece L, Clemensson L, Ozola M, Vavers E, Cirule H, Korzh S, Skuja S, Groma V, Briviba M, Grinberga S, Liu W, Olszewski P, Gentreau M, Fredriksson R, Dambrova M, Schiöth HB. Hydroxymethylglutaryl-CoA reductase activity is essential for mitochondrial β-oxidation of fatty acids to prevent lethal accumulation of long-chain acylcarnitines in the mouse liver. Br J Pharmacol 2024. [PMID: 38641905 DOI: 10.1111/bph.16363] [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: 09/04/2023] [Revised: 01/16/2024] [Accepted: 01/30/2024] [Indexed: 04/21/2024] Open
Abstract
BACKGROUND AND PURPOSE Statins are competitive inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (HMGCR), and exert adverse effects on mitochondrial function, although the mechanisms underlying these effects remain unclear. We used a tamoxifen-induced Hmgcr-knockout (KO) mouse model, a multi-omics approach and mitochondrial function assessments to investigate whether decreased HMGCR activity impacts key liver energy metabolism pathways. EXPERIMENTAL APPROACH We established a new mouse strain using the Cre/loxP system, which enabled whole-body deletion of Hmgcr expression. These mice were crossed with Rosa26Cre mice and treated with tamoxifen to delete Hmgcr in all cells. We performed transcriptomic and metabolomic analyses and thus evaluated time-dependent changes in metabolic functions to identify the pathways leading to cell death in Hmgcr-KO mice. KEY RESULTS Lack of Hmgcr expression resulted in lethality, due to acute liver damage caused by rapid disruption of mitochondrial fatty acid β-oxidation and very high accumulation of long-chain (LC) acylcarnitines in both male and female mice. Gene expression and KO-related phenotype changes were not observed in other tissues. The progression to liver failure was driven by diminished peroxisome formation, which resulted in impaired mitochondrial and peroxisomal fatty acid metabolism, enhanced glucose utilization and whole-body hypoglycaemia. CONCLUSION AND IMPLICATIONS Our findings suggest that HMGCR is crucial for maintaining energy metabolism balance, and its activity is necessary for functional mitochondrial β-oxidation. Moreover, statin-induced adverse reactions might be rescued by the prevention of LC acylcarnitine accumulation.
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Affiliation(s)
- Edgars Liepinsh
- Latvian Institute of Organic Synthesis, Riga, Latvia
- Riga Stradins University, Riga, Latvia
| | | | | | - Melita Ozola
- Latvian Institute of Organic Synthesis, Riga, Latvia
- Riga Stradins University, Riga, Latvia
| | - Edijs Vavers
- Latvian Institute of Organic Synthesis, Riga, Latvia
| | - Helena Cirule
- Latvian Institute of Organic Synthesis, Riga, Latvia
| | | | | | | | - Monta Briviba
- Latvian Biomedical Research and Study Centre, Riga, Latvia
| | | | - Wen Liu
- Uppsala University, Uppsala, Sweden
| | | | | | | | - Maija Dambrova
- Latvian Institute of Organic Synthesis, Riga, Latvia
- Riga Stradins University, Riga, Latvia
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3
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Uribe SE, Maldupa I, Kavadella A, El Tantawi M, Chaurasia A, Fontana M, Marino R, Innes N, Schwendicke F. Artificial intelligence chatbots and large language models in dental education: Worldwide survey of educators. Eur J Dent Educ 2024. [PMID: 38586899 DOI: 10.1111/eje.13009] [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: 07/25/2023] [Revised: 02/15/2024] [Accepted: 03/18/2024] [Indexed: 04/09/2024]
Abstract
INTRODUCTION Interest is growing in the potential of artificial intelligence (AI) chatbots and large language models like OpenAI's ChatGPT and Google's Gemini, particularly in dental education. To explore dental educators' perceptions of AI chatbots and large language models, specifically their potential benefits and challenges for dental education. MATERIALS AND METHODS A global cross-sectional survey was conducted in May-June 2023 using a 31-item online-questionnaire to assess dental educators' perceptions of AI chatbots like ChatGPT and their influence on dental education. Dental educators, representing diverse backgrounds, were asked about their use of AI, its perceived impact, barriers to using chatbots, and the future role of AI in this field. RESULTS 428 dental educators (survey views = 1516; response rate = 28%) with a median [25/75th percentiles] age of 45 [37, 56] and 16 [8, 25] years of experience participated, with the majority from the Americas (54%), followed by Europe (26%) and Asia (10%). Thirty-one percent of respondents already use AI tools, with 64% recognising their potential in dental education. Perception of AI's potential impact on dental education varied by region, with Africa (4[4-5]), Asia (4[4-5]), and the Americas (4[3-5]) perceiving more potential than Europe (3[3-4]). Educators stated that AI chatbots could enhance knowledge acquisition (74.3%), research (68.5%), and clinical decision-making (63.6%) but expressed concern about AI's potential to reduce human interaction (53.9%). Dental educators' chief concerns centred around the absence of clear guidelines and training for using AI chatbots. CONCLUSION A positive yet cautious view towards AI chatbot integration in dental curricula is prevalent, underscoring the need for clear implementation guidelines.
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Affiliation(s)
- Sergio E Uribe
- Department of Conservative Dentistry and Oral Health, Riga Stradins University, Riga, Latvia
- Faculty of Dentistry, Universidad de Valparaiso, Valparaíso, Chile
- Baltic Biomaterials Centre of Excellence, Headquarters at Riga Technical University, Riga, Latvia
- ITU/WHO Focus Group AI on Health, Topic Group Dental, Geneva, Switzerland
| | - Ilze Maldupa
- Department of Conservative Dentistry and Oral Health, Riga Stradins University, Riga, Latvia
| | - Argyro Kavadella
- School of Dentistry, European University Cyprus, Nicosia, Cyprus
| | - Maha El Tantawi
- Faculty of Dentistry, Alexandria University, Alexandria, Egypt
| | - Akhilanand Chaurasia
- ITU/WHO Focus Group AI on Health, Topic Group Dental, Geneva, Switzerland
- Department of Oral Medicine & Radiology, King George's Medical University, Lucknow, Uttar Pradesh, India
| | - Margherita Fontana
- Department of Cariology, Restorative Sciences and Endodontics, School of Dentistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Rodrigo Marino
- Melbourne Dental School, The University of Melbourne, Melbourne, Victoria, Australia
| | - Nicola Innes
- School of Dentistry, College of Biomedical & Life Sciences, Cardiff University, Cardiff, UK
| | - Falk Schwendicke
- ITU/WHO Focus Group AI on Health, Topic Group Dental, Geneva, Switzerland
- Department of Conservative Dentistry and Periodontology, Ludwig-Maximilians-University Munich, Munich, Germany
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Tedersoo L, Drenkhan R, Abarenkov K, Anslan S, Bahram M, Bitenieks K, Buegger F, Gohar D, Hagh‐Doust N, Klavina D, Makovskis K, Zusevica A, Pritsch K, Padari A, Põlme S, Rahimlou S, Rungis D, Mikryukov V. The influence of tree genus, phylogeny, and richness on the specificity, rarity, and diversity of ectomycorrhizal fungi. Environ Microbiol Rep 2024; 16:e13253. [PMID: 38575147 PMCID: PMC10994715 DOI: 10.1111/1758-2229.13253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 03/13/2024] [Indexed: 04/06/2024]
Abstract
Partner specificity is a well-documented phenomenon in biotic interactions, yet the factors that determine specificity in plant-fungal associations remain largely unknown. By utilizing composite soil samples, we identified the predictors that drive partner specificity in both plants and fungi, with a particular focus on ectomycorrhizal associations. Fungal guilds exhibited significant differences in overall partner preference and avoidance, richness, and specificity to specific tree genera. The highest level of specificity was observed in root endophytic and ectomycorrhizal associations, while the lowest was found in arbuscular mycorrhizal associations. The majority of ectomycorrhizal fungal species showed a preference for one of their partner trees, primarily at the plant genus level. Specialist ectomycorrhizal fungi were dominant in belowground communities in terms of species richness and relative abundance. Moreover, all tree genera (and occasionally species) demonstrated a preference for certain fungal groups. Partner specificity was not related to the rarity of fungi or plants or environmental conditions, except for soil pH. Depending on the partner tree genus, specific fungi became more prevalent and relatively more abundant with increasing stand age, tree dominance, and soil pH conditions optimal for the partner tree genus. The richness of partner tree species and increased evenness of ectomycorrhizal fungi in multi-host communities enhanced the species richness of ectomycorrhizal fungi. However, it was primarily the partner-generalist fungi that contributed to the high diversity of ectomycorrhizal fungi in mixed forests.
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Affiliation(s)
- Leho Tedersoo
- Mycology and Microbiology CenterUniversity of TartuTartuEstonia
- Institute of Ecology and Earth SciencesUniversity of TartuTartuEstonia
- College of ScienceKing Saud UniversityRiyadhSaudi Arabia
| | - Rein Drenkhan
- Institute of Forestry and EngineeringEstonian University of Life SciencesTartuEstonia
| | | | - Sten Anslan
- Institute of Ecology and Earth SciencesUniversity of TartuTartuEstonia
| | - Mohammad Bahram
- Mycology and Microbiology CenterUniversity of TartuTartuEstonia
- Department of EcologySwedish University of Agricultural SciencesUppsalaSweden
| | - Kriss Bitenieks
- Latvian State Forest Research Institute ‘Silava’ (LSFRI Silava)SalaspilsLatvia
| | - Franz Buegger
- Helmholtz Zentrum München – German Research Center for Environmental Health (GmbH), Research Unit Environmental SimulationNeuherbergGermany
| | - Daniyal Gohar
- Mycology and Microbiology CenterUniversity of TartuTartuEstonia
- Institute of Ecology and Earth SciencesUniversity of TartuTartuEstonia
| | - Niloufar Hagh‐Doust
- Mycology and Microbiology CenterUniversity of TartuTartuEstonia
- Institute of Ecology and Earth SciencesUniversity of TartuTartuEstonia
| | - Darta Klavina
- Latvian State Forest Research Institute ‘Silava’ (LSFRI Silava)SalaspilsLatvia
| | - Kristaps Makovskis
- Latvian State Forest Research Institute ‘Silava’ (LSFRI Silava)SalaspilsLatvia
| | - Austra Zusevica
- Latvian State Forest Research Institute ‘Silava’ (LSFRI Silava)SalaspilsLatvia
| | - Karin Pritsch
- Helmholtz Zentrum München – German Research Center for Environmental Health (GmbH), Research Unit Environmental SimulationNeuherbergGermany
| | - Allar Padari
- Institute of Forestry and EngineeringEstonian University of Life SciencesTartuEstonia
| | - Sergei Põlme
- Mycology and Microbiology CenterUniversity of TartuTartuEstonia
- Natural History MuseumUniversity of TartuTartuEstonia
| | - Saleh Rahimlou
- Mycology and Microbiology CenterUniversity of TartuTartuEstonia
| | - Dainis Rungis
- Latvian State Forest Research Institute ‘Silava’ (LSFRI Silava)SalaspilsLatvia
| | - Vladimir Mikryukov
- Mycology and Microbiology CenterUniversity of TartuTartuEstonia
- Institute of Ecology and Earth SciencesUniversity of TartuTartuEstonia
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Rozevska M, Kanepa A, Purina S, Gailite L, Nartisa I, Farkas H, Rots D, Kurjane N. Hereditary or acquired? Comprehensive genetic testing assists in stratifying angioedema patients. Allergy Asthma Clin Immunol 2024; 20:28. [PMID: 38555427 PMCID: PMC10981324 DOI: 10.1186/s13223-024-00889-5] [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: 01/26/2024] [Accepted: 03/14/2024] [Indexed: 04/02/2024]
Abstract
Hereditary angioedema (HAE) poses diagnostic challenges due to its episodic, non-specific symptoms and overlapping conditions. This study focuses on the genetic basis of HAE, particularly focusing on unresolved cases and those with normal C1-inhibitor levels (nC1-INH HAE). This study reveals that conventional testing identified pathogenic variants in only 10 patients (n = 32), emphasizing the necessity for an integrative approach using genome, exome, and transcriptome sequencing. Despite extensive genetic analyses, the diagnostic yield for nC1-INH HAE remains low in our study, the pathogenic variant for nC1-INH HAE was identified in only 1 patient (n = 21). Investigation into candidate genes yielded no pathogenic variants, prompting a re-evaluation of patients' diagnoses. This study advocates for a nuanced approach to genetic testing, recognizing its limitations and emphasizing the need for continuous clinical assessment. The complex genetic landscape of nC1-INH HAE necessitates further research for a more comprehensive understanding. In conclusion, this study contributes valuable insights into the genetic intricacies of HAE, highlighting the challenges in diagnosis and the evolving nature of the disease. The findings underscore the importance of advanced sequencing techniques and an integrated diagnostic strategy in unravelling the complexities of HAE, particularly in nС1-INH HAE cases.
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Affiliation(s)
- Marija Rozevska
- Riga Stradiņš University, Riga, Latvia
- Children's clinical university hospital, Riga, Latvia
| | | | - Signe Purina
- Center of Diagnostics and Treatment of Allergic Diseases, Riga, Latvia
| | | | - Inga Nartisa
- Riga Stradiņš University, Riga, Latvia
- Children's clinical university hospital, Riga, Latvia
| | - Henriette Farkas
- Department of Internal Medicine and Haematology, Hungarian Angioedema Center of Reference and Excellence, Semmelweis University, Budapest, Hungary
| | - Dmitrijs Rots
- Riga Stradiņš University, Riga, Latvia
- Children's clinical university hospital, Riga, Latvia
| | - Natalja Kurjane
- Riga Stradiņš University, Riga, Latvia.
- Children's clinical university hospital, Riga, Latvia.
- Pauls Stradiņš Clinical University Hospital, Riga, Latvia.
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6
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Līpiņš DD, Jeminejs A, Ušacka U, Mishnev A, Turks M, Novosjolova I. Regioselective quinazoline C2 modifications through the azide-tetrazole tautomeric equilibrium. Beilstein J Org Chem 2024; 20:675-683. [PMID: 38590535 PMCID: PMC10999978 DOI: 10.3762/bjoc.20.61] [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: 12/15/2023] [Accepted: 03/18/2024] [Indexed: 04/10/2024] Open
Abstract
2-Chloro-4-sulfonylquinazolines undergo functional group swap when treated with an azide nucleophile: 1) the azide replaces the sulfonyl group at the C4 position; 2) the intrinsic azide-tetrazole tautomeric equilibrium directs the nucleofugal sulfinate from the first step to replace chloride at the C2 position. This transformation is effective with quinazolines bearing electron-rich substituents. Therefore, the title transformations are demonstrated on the 6,7-dimethoxyquinazoline core, which is present in pharmaceutically active substances. The methodology application is showcased by transforming the obtained 4-azido-6,7-dimethoxy-2-sulfonylquinazolines into the α1-adrenoceptor blockers terazosin and prazosin by further C2-selective SNAr reaction and azide reduction.
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Affiliation(s)
- Dāgs Dāvis Līpiņš
- Faculty of Natural Sciences and Technology, Riga Technical University, P. Valdena Str. 3, Riga, LV-1048, Latvia
| | - Andris Jeminejs
- Faculty of Natural Sciences and Technology, Riga Technical University, P. Valdena Str. 3, Riga, LV-1048, Latvia
| | - Una Ušacka
- Faculty of Natural Sciences and Technology, Riga Technical University, P. Valdena Str. 3, Riga, LV-1048, Latvia
- Ķekava Secondary School, Gaismas Str. 9, Ķekava, Ķekava Parish, Ķekava Municipality, LV-2123, Latvia
| | - Anatoly Mishnev
- Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, Riga, LV-1006, Latvia
| | - Māris Turks
- Faculty of Natural Sciences and Technology, Riga Technical University, P. Valdena Str. 3, Riga, LV-1048, Latvia
| | - Irina Novosjolova
- Faculty of Natural Sciences and Technology, Riga Technical University, P. Valdena Str. 3, Riga, LV-1048, Latvia
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7
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Briedis M, Hahn S, Bauer S. Duration and variability of spring green-up mediate population consequences of climate change. Ecol Lett 2024; 27:e14380. [PMID: 38348625 DOI: 10.1111/ele.14380] [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: 05/10/2023] [Revised: 01/09/2024] [Accepted: 01/19/2024] [Indexed: 02/15/2024]
Abstract
Single phenological measures, like the average rate of phenological advancement, may be insufficient to explain how climate change is driving trends in animal populations. Here, we develop a multifactorial concept of spring phenology-including the onset of spring, spring duration, interannual variability, and their temporal changes-as a driver for population dynamics of migratory terrestrial species in seasonal environments. Using this conceptual model, we found that effects of advancing spring phenology on animal populations may be buffered or amplified depending on the duration and interannual variability of spring green-up, and those effects are modified by evolutionary and plastic adaptations of species. Furthermore, we compared our modelling results with empirical data on normalized difference vegetation index-based spring green-up phenology and population trends of 106 European landbird finding similar associations. We conclude how phenological changes are expected to affect migratory bird populations across Europe and identify regions that are particularly prone to suffer population declines.
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Affiliation(s)
- Martins Briedis
- Swiss Ornithological Institute, Sempach, Switzerland
- Lab of Ornithology, Institute of Biology, University of Latvia, Riga, Latvia
| | - Steffen Hahn
- Swiss Ornithological Institute, Sempach, Switzerland
| | - Silke Bauer
- Swiss Ornithological Institute, Sempach, Switzerland
- Institute of Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
- Department of Environmental Systems Science, Federal Institute of Technology (ETH) Zürich, Zürich, Switzerland
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8
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Dutovs A, Popļausks R, Putāns O, Perkanuks V, Jurkevičiūtė A, Tamulevičius T, Malinovskis U, Olyshevets I, Erts D, Prikulis J. In situ optical sub-wavelength thickness control of porous anodic aluminum oxide. Beilstein J Nanotechnol 2024; 15:126-133. [PMID: 38317824 PMCID: PMC10840541 DOI: 10.3762/bjnano.15.12] [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: 11/07/2023] [Accepted: 01/11/2024] [Indexed: 02/07/2024]
Abstract
Porous anodic aluminum oxide (PAAO), sometimes referred to as nanoporous anodic alumina, serves as a cost-effective template for nanofabrication in many fields of science and engineering. However, production of ultrathin PAAO membranes with precise thickness in the optical sub-wavelength range remains challenging because of difficulties regarding process control at the initial stage of anodic oxidation. In this study, we demonstrate a technique for consistently manufacturing PAAO with the targeted thickness. An electrochemical cell with an optical window was designed for reflectance spectroscopy of PAAO during anodization. Real-time fitting of spectra to a transfer-matrix model enabled continuous monitoring of the thickness growth of the PAAO layer. Automation software was designed to terminate the anodization process at preset PAAO thickness values. While the concept was illustrated using the widely used method of anodization in a 0.3 M oxalic acid electrolyte with a 40 V potential, it can be readily customized for other protocols. PAAO layers with effective thickness below 300 nm could be produced with a few nanometers accuracy using single-crystal aluminum substrates. The results were confirmed using spectroscopic ellipsometry. The method for controlling the thickness during anodization eliminates the necessity of sample sectioning for electron microscopy and is particularly valuable for the small-scale production of PAAO-based functional optical coatings.
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Affiliation(s)
- Aleksandrs Dutovs
- Institute of Chemical Physics, University of Latvia, 19 Raina Blvd., Riga LV-1586, Latvia
| | - Raimonds Popļausks
- Institute of Chemical Physics, University of Latvia, 19 Raina Blvd., Riga LV-1586, Latvia
| | - Oskars Putāns
- Institute of Chemical Physics, University of Latvia, 19 Raina Blvd., Riga LV-1586, Latvia
| | - Vladislavs Perkanuks
- Institute of Chemical Physics, University of Latvia, 19 Raina Blvd., Riga LV-1586, Latvia
| | - Aušrinė Jurkevičiūtė
- Institute of Chemical Physics, University of Latvia, 19 Raina Blvd., Riga LV-1586, Latvia
- Institute of Materials Science of Kaunas University of Technology, K. Baršausko St. 59, Kaunas LT-51423, Lithuania
| | - Tomas Tamulevičius
- Institute of Materials Science of Kaunas University of Technology, K. Baršausko St. 59, Kaunas LT-51423, Lithuania
- Department of Physics, Faculty of Mathematics and Natural Sciences, Kaunas University of Technology, Studentų St. 50, Kaunas LT-51368, Lithuania
| | - Uldis Malinovskis
- Institute of Chemical Physics, University of Latvia, 19 Raina Blvd., Riga LV-1586, Latvia
| | - Iryna Olyshevets
- Institute of Chemical Physics, University of Latvia, 19 Raina Blvd., Riga LV-1586, Latvia
| | - Donats Erts
- Institute of Chemical Physics, University of Latvia, 19 Raina Blvd., Riga LV-1586, Latvia
- Faculty of Chemistry, University of Latvia, 1 Jelgavas Str., Riga LV-1004, Latvia
| | - Juris Prikulis
- Institute of Chemical Physics, University of Latvia, 19 Raina Blvd., Riga LV-1586, Latvia
- Faculty of Physics, Mathematics and Optometry, University of Latvia, 3 Jelgavas Str., Riga LV-1004, Latvia
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9
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Estiri H, Bhattacharya S, Buitrago JAR, Castagna R, Legzdiņa L, Casucci G, Ricci A, Parisini E, Gautieri A. Tailoring FPOX enzymes for enhanced stability and expanded substrate recognition. Sci Rep 2023; 13:18610. [PMID: 37903872 PMCID: PMC10616090 DOI: 10.1038/s41598-023-45428-1] [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: 07/13/2023] [Accepted: 10/19/2023] [Indexed: 11/01/2023] Open
Abstract
Fructosyl peptide oxidases (FPOX) are deglycating enzymes that find application as key enzymatic components in diabetes monitoring devices. Indeed, their use with blood samples can provide a measurement of the concentration of glycated hemoglobin and glycated albumin, two well-known diabetes markers. However, the FPOX currently employed in enzymatic assays cannot directly detect whole glycated proteins, making it necessary to perform a preliminary proteolytic treatment of the target protein to generate small glycated peptides that can act as viable substrates for the enzyme. This is a costly and time consuming step. In this work, we used an in silico protein engineering approach to enhance the overall thermal stability of the enzyme and to improve its catalytic activity toward large substrates. The final design shows a marked improvement in thermal stability relative to the wild type enzyme, a distinct widening of its access tunnel and significant enzymatic activity towards a range of glycated substrates.
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Affiliation(s)
- Hajar Estiri
- Department of Biotechnology, Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, 1006, Latvia
| | - Shapla Bhattacharya
- Department of Biotechnology, Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, 1006, Latvia
- Faculty of Materials Science and Applied Chemistry, Riga Technical University, Paula Valdena 3, Riga, 1048, Latvia
| | | | - Rossella Castagna
- Department of Biotechnology, Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, 1006, Latvia
- Dipartimento di Chimica, Materiali e Ingegneria Chimica "Giulio Natta", Politecnico di Milano, Piazza L. da Vinci 32, 20133, Milano, Italy
| | - Linda Legzdiņa
- Department of Biotechnology, Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, 1006, Latvia
| | - Giorgia Casucci
- Department of Biotechnology, Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, 1006, Latvia
| | - Andrea Ricci
- Biomolecular Engineering Lab, Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milano, Italy
| | - Emilio Parisini
- Department of Biotechnology, Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, 1006, Latvia.
- Department of Chemistry "G. Ciamician", University of Bologna, Via Selmi 2, 40126, Bologna, Italy.
| | - Alfonso Gautieri
- Biomolecular Engineering Lab, Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milano, Italy.
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10
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Sperga A, Veliks J. Recent Advances in Monofluorinated Carbenes, Carbenoids, Ylides, and Related Species. Chemistry 2023:e202301851. [PMID: 37902650 DOI: 10.1002/chem.202301851] [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: 06/15/2023] [Indexed: 10/31/2023]
Abstract
The synthesis of monofluorinated compounds is of great interest because of the vast applications of organofluorine compounds. Recently, the introduction of monofluorocarbene synthons has emerged as an important strategy for the synthesis of fluorine-containing products. In contrast to direct fluorination, in which C-F bonds are formed, the use of monofluorinated carbenes and related reactive species involves C-C or C-X bond formation while delivering valuable fluorine atoms into the target structure. Owing to increased knowledge on carbon-carbon and carbon-heteroatom bond formations, monofluorinated carbenes have enormous potential for the synthesis of organofluorine compounds, which, in our opinion, has not yet been fully exploited. This review summarizes the recent advances in the synthetic applications of monofluorinated carbenes, carbenoids, ylides, and related species.
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Affiliation(s)
- Arturs Sperga
- Latvian Institute of OrganicSynthesis, Aizkrauklesiela 21, 1006, Riga, Latvia
| | - Janis Veliks
- Latvian Institute of OrganicSynthesis, Aizkrauklesiela 21, 1006, Riga, Latvia
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11
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Liepinsh E, Svalbe B, Stelfa G, Grinberga S, Zvejniece L, Schiöth HB, Dambrova M. Knockout of Tmlhe in mice is not associated with autism spectrum disorder phenotypes or motor dysfunction despite low carnitine levels. Mol Autism 2023; 14:29. [PMID: 37553674 PMCID: PMC10410785 DOI: 10.1186/s13229-023-00560-7] [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: 03/20/2023] [Accepted: 07/12/2023] [Indexed: 08/10/2023] Open
Abstract
Deletion of exon 2 of the trimethyllysine hydroxylase epsilon (TMLHE) gene was identified in probands with autism spectrum disorder (ASD). TMLHE encodes the first enzyme in carnitine biosynthesis, N6-trimethyllysine dioxygenase (TMLD). Researchers have suggested that carnitine depletion could be important for the development of ASD and cognitive, locomotor and social dysfunctions, but previous findings have been inconclusive regarding the specific role of endogenous carnitine. We developed a mouse knockout model with constitutive TMLD enzyme inactivation that exhibited a significant decrease in the carnitine by more than 90% compared to wild-type (WT) mice. However, we did not observe any significant social, cognitive, or repetitive-behavior changes associated with ASD in the knockout mice; muscle strength and coordination were also not affected. In addition, the life expectancy of knockout mice was similar to that of WT mice. In conclusion, knockout of Tmlh in mice does not induce an ASD phenotype or motor dysfunction despite extremely low carnitine and gamma-butyrobetaine concentrations. Moreover, inactivation of TMLD does not induce a phenotype similar to previously described primary carnitine deficiency; indeed, our results showed that low levels of carnitine sustained adequate energy production, muscle function and social behavior in mice.
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Affiliation(s)
- Edgars Liepinsh
- Latvian Institute of Organic Synthesis, Riga, Latvia.
- Riga Stradins University, Riga, Latvia.
| | - Baiba Svalbe
- Latvian Institute of Organic Synthesis, Riga, Latvia
| | - Gundega Stelfa
- Latvian Institute of Organic Synthesis, Riga, Latvia
- Latvia University of Life Sciences and Technologies, Jelgava, Latvia
| | | | | | | | - Maija Dambrova
- Latvian Institute of Organic Synthesis, Riga, Latvia
- Riga Stradins University, Riga, Latvia
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12
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Beauchamp G, Krams I. Flock size increases with the diversity and abundance of local predators in an avian family. Oecologia 2023:10.1007/s00442-023-05425-7. [PMID: 37493857 DOI: 10.1007/s00442-023-05425-7] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 07/17/2023] [Indexed: 07/27/2023]
Abstract
Group living has long been viewed as an adaptation to reduce predation risk. Earlier comparative analyses provided support for the hypothesis but typically ignored variation in group size at the local scale and included proxies of predation risk rather than more direct estimates. Here, we related variation in group size at the scale of a study site in various species with the diversity and abundance of local predators. If larger groups provide protection against predators, we expected larger groups to evolve in species facing locally more diverse and abundant predators. We examined this hypothesis in one avian family, the Paridae, which are small arboreal birds that include some of the better studied species in ecology. From the literature, we gathered 275 flock size estimates from 34 species. In a phylogenetic framework and controlling for the potential confounding effect of latitude, we found that flock size increased with predation risk but only in flocks that included more than one species. We suggest that competition sets an upper limit to the size of flocks including conspecifics only. Joining flocks with other species, thus, allows individuals to increase flock size in response to higher predation risk without a substantial increase in competition. Overall, our results based on more direct estimates of predation risk provide further comparative evidence for an association between predation and the evolution of flocking in birds.
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Affiliation(s)
| | - Indrikis Krams
- Department of Biotechnology, Daugavpils University, Daugavpils, 5404, Latvia
- Department of Zoology and Animal Ecology, Faculty of Biology, University of Latvia, Riga, 1004, Latvia
- Institute of Ecology and Earth Sciences, University of Tartu, 50409, Tartu, Estonia
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13
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Krama T, Munkevics M, Krams R, Grigorjeva T, Trakimas G, Jõers P, Popovs S, Zants K, Elferts D, Rantala MJ, Sledevskis E, Contreras-Garduño J, de Bivort BL, Krams IA. Development under predation risk increases serotonin-signaling, variability of turning behavior and survival in adult fruit flies Drosophila melanogaster. Front Behav Neurosci 2023; 17:1189301. [PMID: 37304760 PMCID: PMC10248140 DOI: 10.3389/fnbeh.2023.1189301] [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: 03/18/2023] [Accepted: 05/09/2023] [Indexed: 06/13/2023] Open
Abstract
The development of high-throughput behavioral assays, where numerous individual animals can be analyzed in various experimental conditions, has facilitated the study of animal personality. Previous research showed that isogenic Drosophila melanogaster flies exhibit striking individual non-heritable locomotor handedness. The variability of this trait, i.e., the predictability of left-right turn biases, varies across genotypes and under the influence of neural activity in specific circuits. This suggests that the brain can dynamically regulate the extent of animal personality. It has been recently shown that predators can induce changes in prey phenotypes via lethal or non-lethal effects affecting the serotonergic signaling system. In this study, we tested whether fruit flies grown with predators exhibit higher variability/lower predictability in their turning behavior and higher survival than those grown with no predators in their environment. We confirmed these predictions and found that both effects were blocked when flies were fed an inhibitor (αMW) of serotonin synthesis. The results of this study demonstrate a negative association between the unpredictability of turning behavior of fruit flies and the hunting success of their predators. We also show that the neurotransmitter serotonin controls predator-induced changes in the turning variability of fruit flies, regulating the dynamic control of behavioral predictability.
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Affiliation(s)
- Tatjana Krama
- Department of Biotechnology, Institute of Life Sciences and Technologies, Daugavpils University, Daugavpils, Latvia
- Chair of Plant Health, Estonian University of Life Sciences, Tartu, Estonia
| | - Māris Munkevics
- Department of Biotechnology, Institute of Life Sciences and Technologies, Daugavpils University, Daugavpils, Latvia
- Department of Zoology and Animal Ecology, Faculty of Biology, University of Latvia, Riga, Latvia
| | - Ronalds Krams
- Department of Biotechnology, Institute of Life Sciences and Technologies, Daugavpils University, Daugavpils, Latvia
- Chair of Plant Health, Estonian University of Life Sciences, Tartu, Estonia
| | - Tatjana Grigorjeva
- Department of Biotechnology, Institute of Life Sciences and Technologies, Daugavpils University, Daugavpils, Latvia
| | - Giedrius Trakimas
- Department of Biotechnology, Institute of Life Sciences and Technologies, Daugavpils University, Daugavpils, Latvia
- Institute of Biosciences, Vilnius University, Vilnius, Lithuania
| | - Priit Jõers
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Sergejs Popovs
- Department of Biotechnology, Institute of Life Sciences and Technologies, Daugavpils University, Daugavpils, Latvia
| | - Krists Zants
- Department of Zoology and Animal Ecology, Faculty of Biology, University of Latvia, Riga, Latvia
| | - Didzis Elferts
- Department of Botany and Ecology, Faculty of Biology, University of Latvia, Riga, Latvia
| | - Markus J. Rantala
- Department of Biology, Turku Brain and Mind Center, University of Turku, Turku, Finland
| | - Eriks Sledevskis
- Department of Technology, Institute of Life Sciences and Technologies, Daugavpils University, Daugavpils, Latvia
| | - Jorge Contreras-Garduño
- Escuela Nacional de Estudios Superiores, Universidad Nacional Autónoma de México, Morelia, Mexico
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Benjamin L. de Bivort
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, United States
| | - Indrikis A. Krams
- Department of Zoology and Animal Ecology, Faculty of Biology, University of Latvia, Riga, Latvia
- Latvian Biomedical Research and Study Centre, Riga, Latvia
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
- Department of Psychology, University of Tennessee, Knoxville, Knoxville, TN, United States
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14
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Kuznetsov AV, Canós Valero A, Shamkhi HK, Terekhov P, Ni X, Bobrovs V, Rybin MV, Shalin AS. Special scattering regimes for conical all-dielectric nanoparticles. Sci Rep 2022; 12:21904. [PMID: 36535983 PMCID: PMC9763421 DOI: 10.1038/s41598-022-25542-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [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: 09/14/2022] [Accepted: 11/30/2022] [Indexed: 12/23/2022] Open
Abstract
All-dielectric nanophotonics opens a venue for a variety of novel phenomena and scattering regimes driven by unique optical effects in semiconductor and dielectric nanoresonators. Their peculiar optical signatures enabled by simultaneous electric and magnetic responses in the visible range pave a way for a plenty of new applications in nano-optics, biology, sensing, etc. In this work, we investigate fabrication-friendly truncated cone resonators and achieve several important scattering regimes due to the inherent property of cones-broken symmetry along the main axis without involving complex geometries or structured beams. We show this symmetry breaking to deliver various kinds of Kerker effects (generalized and transverse Kerker effects), non-scattering hybrid anapole regime (simultaneous anapole conditions for all the multipoles in a particle leading to the nearly full scattering suppression) and, vice versa, superscattering regime. Being governed by the same straightforward geometrical paradigm, discussed effects could greatly simplify the manufacturing process of photonic devices with different functionalities. Moreover, the additional degrees of freedom driven by the conicity open new horizons to tailor light-matter interactions at the nanoscale.
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Affiliation(s)
- Alexey V Kuznetsov
- Center for Photonics and 2D Materials, Moscow Institute of Physics and Technology, Dolgoprudny, Russia, 141700.
- Institute of Telecommunications, Riga Technical University, Riga, 1048, Latvia.
- Faculty of Physics, ITMO University, St. Petersburg, Russia, 197101.
| | - Adrià Canós Valero
- Faculty of Physics, ITMO University, St. Petersburg, Russia, 197101
- Institute of Physics, University of Graz, and NAWI Graz, 8010, Graz, Austria
| | - Hadi K Shamkhi
- Faculty of Physics, ITMO University, St. Petersburg, Russia, 197101
- A*STAR (Agency for Science, Technology and Research), Singapore, 138634, Singapore
| | - Pavel Terekhov
- Department of Electrical Engineering, The Pennsylvania State University, State College, Pennsylvania, 16802, USA
| | - Xingjie Ni
- Department of Electrical Engineering, The Pennsylvania State University, State College, Pennsylvania, 16802, USA
| | - Vjaceslavs Bobrovs
- Institute of Telecommunications, Riga Technical University, Riga, 1048, Latvia
| | - Mikhail V Rybin
- Faculty of Physics, ITMO University, St. Petersburg, Russia, 197101
| | - Alexander S Shalin
- Center for Photonics and 2D Materials, Moscow Institute of Physics and Technology, Dolgoprudny, Russia, 141700.
- Institute of Telecommunications, Riga Technical University, Riga, 1048, Latvia.
- Faculty of Physics, Moscow State University, Moscow, Russia, 119991.
- School of Optical and Electronic Information, Suzhou City University, Suzhou, 215104, China.
- Kotelnikov Institute of Radio Engineering and Electronics, 432000, Ulyanovsk, Russia.
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15
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Roge I, Smane L, Kivite-Urtane A, Pucuka Z, Racko I, Klavina L, Pavare J. Comparison of Persistent Symptoms After COVID-19 and Other Non-SARS-CoV-2 Infections in Children. Front Pediatr 2021; 9:752385. [PMID: 34778143 PMCID: PMC8586002 DOI: 10.3389/fped.2021.752385] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 09/29/2021] [Indexed: 11/13/2022] Open
Abstract
Introduction: The data on long COVID in children is scarce since children and adolescents are typically less severely affected by acute COVID-19. This study aimed to identify the long-term consequences of SARS-CoV-2 infection in children, and to compare the persistent symptom spectrum between COVID-19 and community-acquired infections of other etiologies. Methods: This was an ambidirectional cohort study conducted at the Children's Clinical University Hospital in Latvia. The study population of pediatric COVID-19 patients and children with other non-SARS-CoV-2-community-acquired infections were invited to participate between July 1, 2020, and April 30, 2021. Results: In total, 236 pediatric COVID-19 patients were enrolled in the study. Additionally, 142 comparison group patients were also enrolled. Median follow-up time from acute symptom onset was 73.5 days (IQR; 43-110 days) in the COVID-19 patient group and 69 days (IQR, 58-84 days) in the comparison group. Most pediatric COVID-19 survivors (70%, N = 152) reported at least one persistent symptom, but more than half of the patients (53%, N = 117) noted two or more long-lasting symptoms. The most commonly reported complaints among COVID-19 patients included persistent fatigue (25.2%), cognitive sequelae, such as irritability (24.3%), and mood changes (23.3%), as well as headaches (16.9%), rhinorrhea (16.1%), coughing (14.4%), and anosmia/dysgeusia (12.3%). In addition, 105 (44.5%) COVID patients had persistent symptoms after the 12-week cut-off point, with irritability (27.6%, N = 29), mood changes (26.7%, N = 28), and fatigue (19.2%, N = 20) being the most commonly reported ones. Differences in symptom spectrum among the various age groups were seen. Logistic regression analysis showed that long-term persistent symptoms as fever, fatigue, rhinorrhea, loss of taste and/or smell, headaches, cognitive sequelae, and nocturnal sweating were significantly associated with the COVID-19 experience when compared with the controls. Conclusions: We found that at the time of interview almost three-quarters of children reported at least one persistent symptom, but the majority of patients (53%) had two or more concurrent symptoms. The comparison group's inclusion in the study allowed us to identify that symptom persistence is more apparent with COVID-19 than any other non-SARS-CoV-2 infection. More research is needed to distinguish the symptoms of long COVID from pandemic-associated complaints. Each persistent symptom is important in terms of child well-being during COVID-19 recovery.
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Affiliation(s)
- Ieva Roge
- Department of Continuing Education, Riga Stradins University, Children's Clinical University Hospital, Riga, Latvia
| | - Liene Smane
- Department of Pediatrics, Children's Clinical University Hospital, Riga Stradins University, Riga, Latvia
| | - Anda Kivite-Urtane
- Department of Public Health and Epidemiology, Institute of Public Health, Riga Stradins University, Riga, Latvia
| | - Zanda Pucuka
- Department of Pediatrics, Children's Clinical University Hospital, Riga Stradins University, Riga, Latvia
| | - Iveta Racko
- Department of Continuing Education, Riga Stradins University, Children's Clinical University Hospital, Riga, Latvia
| | - Lizete Klavina
- Department of Continuing Education, Riga Stradins University, Children's Clinical University Hospital, Riga, Latvia
| | - Jana Pavare
- Department of Pediatrics, Children's Clinical University Hospital, Riga Stradins University, Riga, Latvia
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16
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Fedorenko V, Damberga D, Grundsteins K, Ramanavicius A, Ramanavicius S, Coy E, Iatsunskyi I, Viter R. Application of Polydopamine Functionalized Zinc Oxide for Glucose Biosensor Design. Polymers (Basel) 2021; 13:2918. [PMID: 34502958 PMCID: PMC8433701 DOI: 10.3390/polym13172918] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [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: 07/18/2021] [Revised: 08/26/2021] [Accepted: 08/27/2021] [Indexed: 12/29/2022] Open
Abstract
Zinc oxide (ZnO) nanostructures are widely used in optical sensors and biosensors. Functionalization of these nanostructures with polymers enables optical properties of ZnO to be tailored. Polydopamine (PDA) is a highly biocompatible polymer, which can be used as a versatile coating suitable for application in sensor and biosensor design. In this research, we have grown ZnO-based nanorods on the surface of ITO-modified glass-plated optically transparent electrodes (glass/ITO). Then the deposition of the PDA polymer layer on the surface of ZnO nanorods was performed from an aqueous PDA solution in such a way glass/ITO/ZnO-PDA structure was formed. The ZnO-PDA composite was characterized by SEM, TEM, and FTIR spectroscopy. Then glucose oxidase (GOx) was immobilized using crosslinking by glutaraldehyde on the surface of the ZnO-PDA composite, and glass/ITO/ZnO-PDA/GOx-based biosensing structure was designed. This structure was applied for the photo-electrochemical determination of glucose (Glc) in aqueous solutions. Photo-electrochemical determination of glucose by cyclic voltammetry and amperometry has been performed by glass/ITO/ZnO-PDA/GOx-based biosensor. Here reported modification/functionalization of ZnO nanorods with PDA enhances the photo-electrochemical performance of ZnO nanorods, which is well suited for the design of photo-electrochemical sensors and biosensors.
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Affiliation(s)
- Viktoriia Fedorenko
- Institute of Atomic Physics and Spectroscopy, University of Latvia, Jelgavas 3, LV-1004 Riga, Latvia; (V.F.); (D.D.); (K.G.); (A.R.)
| | - Daina Damberga
- Institute of Atomic Physics and Spectroscopy, University of Latvia, Jelgavas 3, LV-1004 Riga, Latvia; (V.F.); (D.D.); (K.G.); (A.R.)
| | - Karlis Grundsteins
- Institute of Atomic Physics and Spectroscopy, University of Latvia, Jelgavas 3, LV-1004 Riga, Latvia; (V.F.); (D.D.); (K.G.); (A.R.)
| | - Arunas Ramanavicius
- Institute of Atomic Physics and Spectroscopy, University of Latvia, Jelgavas 3, LV-1004 Riga, Latvia; (V.F.); (D.D.); (K.G.); (A.R.)
- Institute of Chemistry, Department of Physical Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko Str. 24, LT-03225 Vilnius, Lithuania;
| | - Simonas Ramanavicius
- Institute of Chemistry, Department of Physical Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko Str. 24, LT-03225 Vilnius, Lithuania;
| | - Emerson Coy
- NanoBioMedical Centre, Adam Mickiewicz University in Poznan, Wszechnicy Piastowskiej Str. 3, 61-614 Poznan, Poland; (E.C.); (I.I.)
| | - Igor Iatsunskyi
- NanoBioMedical Centre, Adam Mickiewicz University in Poznan, Wszechnicy Piastowskiej Str. 3, 61-614 Poznan, Poland; (E.C.); (I.I.)
| | - Roman Viter
- Institute of Atomic Physics and Spectroscopy, University of Latvia, Jelgavas 3, LV-1004 Riga, Latvia; (V.F.); (D.D.); (K.G.); (A.R.)
- Center for Collective Use of Scientific Equipment, Sumy State University, 31, Sanatornaya Str., 40000 Sumy, Ukraine
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17
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Zrelovs N, Dislers A, Kazaks A. Genome Characterization of Nocturne116, Novel Lactococcus lactis-Infecting Phage Isolated from Moth. Microorganisms 2021; 9:1540. [PMID: 34361975 PMCID: PMC8306868 DOI: 10.3390/microorganisms9071540] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 07/16/2021] [Accepted: 07/17/2021] [Indexed: 12/04/2022] Open
Abstract
While looking for novel insect-associated phages, a unique siphophage, Nocturne116, was isolated from a deceased local moth specimen along with its host, which was identified by 16S rRNA gene sequencing as a strain of Lactococcus lactis. Next-generation sequencing and the subsequent genome annotation elaborated on herein revealed that the genome of Nocturne116 is a 25,554 bp long dsDNA molecule with 10 bp long 3' cos overhangs and a GC content of 37.99%, comprising 52 predicted open reading frames. The complete nucleotide sequence of phage Nocturne116 genome is dissimilar to any of the already sequenced phages, save for a distant link with Lactococcus phage Q54. Functions for only 15/52 of Nocturne116 gene products could be reliably predicted using contemporary comparative genomics approaches, while 22 of its gene products do not yet have any homologous entries in the public biological sequence repositories. Despite the public availability of nearly 350 elucidated Lactococcus phage complete genomes as of now, Nocturne116 firmly stands out as a sole representative of novel phage genus.
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Affiliation(s)
| | - Andris Dislers
- Latvian Biomedical Research and Study Centre, Ratsupites 1 k-1, LV-1067 Riga, Latvia;
| | - Andris Kazaks
- Latvian Biomedical Research and Study Centre, Ratsupites 1 k-1, LV-1067 Riga, Latvia;
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18
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Krams R, Krama T, Brūmelis G, Elferts D, Strode L, Dauškane I, Luoto S, Šmits A, Krams IA. Ecological traps: evidence of a fitness cost in a cavity-nesting bird. Oecologia 2021; 196:735-745. [PMID: 34155528 PMCID: PMC8292250 DOI: 10.1007/s00442-021-04969-w] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 06/10/2021] [Indexed: 11/26/2022]
Abstract
Habitat quality has direct effects on the evolutionary fitness of breeding organisms, which is why it is believed that animals tend to have an evolved preference for the best possible habitats. However, some animals may mistakenly choose to reproduce in habitats that decrease their fitness, resulting in 'ecological traps'. In this study, we tested whether great tits (Parus major) attracted to areas affected by outbreaks of the great web-spinning sawfly (Acantholyda posticalis) had fitness detriments characteristic of ecological traps. Sawfly larvae consume pine needles, which decreases resource availability for birds co-habiting the forest. Using artificial nesting sites, we found that great tits inhabiting areas of sawfly outbreaks had similar clutch sizes as tits breeding in healthy forest patches; however, the fledgling number was significantly lower, and fledgling condition was worse in the damaged forests. While moth larvae are the most important food for bird nestlings, the forest patches damaged by sawflies had lower larval biomass. Although most ecological traps occur in environments altered by humans, this study shows that pest insects can lower habitat quality, forming ecological traps. Our results indicate that attracting cavity-nesting birds should be done with caution because it may negatively impact birds' nutritional status and reproductive fitness.
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Affiliation(s)
- Ronalds Krams
- Department of Biotechnology, Daugavpils University, Daugavpils, 5401, Latvia
- Chair of Plant Health, Estonian University of Life Sciences, 51006, Tartu, Estonia
| | - Tatjana Krama
- Department of Biotechnology, Daugavpils University, Daugavpils, 5401, Latvia
- Chair of Plant Health, Estonian University of Life Sciences, 51006, Tartu, Estonia
| | - Guntis Brūmelis
- Department of Botany and Ecology, Faculty of Biology, University of Latvia, Riga, 1004, Latvia
| | - Didzis Elferts
- Department of Botany and Ecology, Faculty of Biology, University of Latvia, Riga, 1004, Latvia
| | - Linda Strode
- Department of Botany and Ecology, Faculty of Biology, University of Latvia, Riga, 1004, Latvia
| | - Iluta Dauškane
- Department of Botany and Ecology, Faculty of Biology, University of Latvia, Riga, 1004, Latvia
| | - Severi Luoto
- English, Drama and Writing Studies, University of Auckland, Auckland, 1010, New Zealand
- School of Psychology, University of Auckland, Auckland, 1010, New Zealand
| | - Agnis Šmits
- Latvian State Forest Research Institute "Silava", Salaspils, 2169, Latvia
| | - Indrikis A Krams
- Department of Biotechnology, Daugavpils University, Daugavpils, 5401, Latvia.
- Department of Zoology and Animal Ecology, Faculty of Biology, University of Latvia, Riga, 1004, Latvia.
- Institute of Ecology and Earth Science, University of Tartu, Vanemuise 46, 51014, Tartu, Estonia.
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19
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Krams IA, Jõers P, Luoto S, Trakimas G, Lietuvietis V, Krams R, Kaminska I, Rantala MJ, Krama T. The Obesity Paradox Predicts the Second Wave of COVID-19 to Be Severe in Western Countries. Int J Environ Res Public Health 2021; 18:ijerph18031029. [PMID: 33503828 PMCID: PMC7908102 DOI: 10.3390/ijerph18031029] [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] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/12/2021] [Accepted: 01/22/2021] [Indexed: 12/31/2022]
Abstract
While COVID-19 infection and mortality rates are soaring in Western countries, Southeast Asian countries have successfully avoided the second wave of the SARS-CoV-2 pandemic despite high population density. We provide a biochemical hypothesis for the connection between low COVID-19 incidence, mortality rates, and high visceral adiposity in Southeast Asian populations. The SARS-CoV-2 virus uses angiotensin-converting enzyme 2 (ACE2) as a gateway into the human body. Although the highest expression levels of ACE2 are found in people’s visceral adipose tissue in Southeast Asia, this does not necessarily make them vulnerable to COVID-19. Hypothetically, high levels of visceral adiposity cause systemic inflammation, thus decreasing the ACE2 amount on the surface of both visceral adipocytes and alveolar epithelial type 2 cells in the lungs. Extra weight gained during the pandemic is expected to increase visceral adipose tissue in Southeast Asians, further decreasing the ACE2 pool. In contrast, weight gain can increase local inflammation in fat depots in Western people, leading to worse COVID-related outcomes. Because of the biological mechanisms associated with fat accumulation, inflammation, and their differential expression in Southeast Asian and Western populations, the second wave of the pandemic may be more severe in Western countries, while Southeast Asians may benefit from their higher visceral fat depots.
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Affiliation(s)
- Indrikis A. Krams
- Department of Biotechnology, Daugavpils University, LV5401 Daugavpils, Latvia; (R.K.); (T.K.)
- Institute of Ecology and Earth Sciences, University of Tartu, EE51014 Tartu, Estonia
- Department of Zoology and Animal Ecology, Faculty of Biology, University of Latvia, LV1004 Riga, Latvia
- Correspondence:
| | - Priit Jõers
- Institute of Molecular and Cell Biology, University of Tartu, EE51010 Tartu, Estonia;
| | - Severi Luoto
- School of Psychology, University of Auckland, 1142 Auckland, New Zealand;
| | - Giedrius Trakimas
- Institute of Biosciences, Vilnius University, 10257 Vilnius, Lithuania;
| | - Vilnis Lietuvietis
- Department of Surgery, Riga Stradins University, LV1007 Riga, Latvia;
- Riga East Clinical University Hospital, LV1010 Riga, Latvia
| | - Ronalds Krams
- Department of Biotechnology, Daugavpils University, LV5401 Daugavpils, Latvia; (R.K.); (T.K.)
- Department of Anatomy and Physiology, Daugavpils University, LV5401 Daugavpils, Latvia;
| | - Irena Kaminska
- Department of Anatomy and Physiology, Daugavpils University, LV5401 Daugavpils, Latvia;
| | - Markus J. Rantala
- Department of Biology, Section of Ecology, University of Turku, FI-20014 Turku, Finland;
| | - Tatjana Krama
- Department of Biotechnology, Daugavpils University, LV5401 Daugavpils, Latvia; (R.K.); (T.K.)
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Isaguliants M, Bayurova E, Avdoshina D, Kondrashova A, Chiodi F, Palefsky JM. Oncogenic Effects of HIV-1 Proteins, Mechanisms Behind. Cancers (Basel) 2021; 13:305. [PMID: 33467638 PMCID: PMC7830613 DOI: 10.3390/cancers13020305] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [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: 12/01/2020] [Revised: 12/28/2020] [Accepted: 01/04/2021] [Indexed: 02/08/2023] Open
Abstract
People living with human immunodeficiency virus (HIV-1) are at increased risk of developing cancer, such as Kaposi sarcoma (KS), non-Hodgkin lymphoma (NHL), cervical cancer, and other cancers associated with chronic viral infections. Traditionally, this is linked to HIV-1-induced immune suppression with depletion of CD4+ T-helper cells, exhaustion of lymphopoiesis and lymphocyte dysfunction. However, the long-term successful implementation of antiretroviral therapy (ART) with an early start did not preclude the oncological complications, implying that HIV-1 and its antigens are directly involved in carcinogenesis and may exert their effects on the background of restored immune system even when present at extremely low levels. Experimental data indicate that HIV-1 virions and single viral antigens can enter a wide variety of cells, including epithelial. This review is focused on the effects of five viral proteins: envelope protein gp120, accessory protein negative factor Nef, matrix protein p17, transactivator of transcription Tat and reverse transcriptase RT. Gp120, Nef, p17, Tat, and RT cause oxidative stress, can be released from HIV-1-infected cells and are oncogenic. All five are in a position to affect "innocent" bystander cells, specifically, to cause the propagation of (pre)existing malignant and malignant transformation of normal epithelial cells, giving grounds to the direct carcinogenic effects of HIV-1.
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Affiliation(s)
- Maria Isaguliants
- Gamaleya Research Center for Epidemiology and Microbiology, 123098 Moscow, Russia; (E.B.); (D.A.)
- M.P. Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, 108819 Moscow, Russia;
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 17177 Stockholm, Sweden;
- Department of Research, Riga Stradins University, LV-1007 Riga, Latvia
| | - Ekaterina Bayurova
- Gamaleya Research Center for Epidemiology and Microbiology, 123098 Moscow, Russia; (E.B.); (D.A.)
- M.P. Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, 108819 Moscow, Russia;
| | - Darya Avdoshina
- Gamaleya Research Center for Epidemiology and Microbiology, 123098 Moscow, Russia; (E.B.); (D.A.)
- M.P. Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, 108819 Moscow, Russia;
| | - Alla Kondrashova
- M.P. Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, 108819 Moscow, Russia;
| | - Francesca Chiodi
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 17177 Stockholm, Sweden;
| | - Joel M. Palefsky
- Department of Medicine, University of California, San Francisco, CA 94117, USA;
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Mezinska S, Kaleja J, Mileiko I. Becoming and being a biobank donor: The role of relationships and ethics. PLoS One 2020; 15:e0242828. [PMID: 33227030 PMCID: PMC7682884 DOI: 10.1371/journal.pone.0242828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 11/10/2020] [Indexed: 12/01/2022] Open
Abstract
Relational aspects, such as involvement of donor's relatives or friends in the decision-making on participation in a research biobank, providing relatives' health data to researchers, or sharing research findings with relatives should be considered when reflecting on ethical aspects of research biobanks. The aim of this paper is to explore what the role of donor's relatives and friends is in the process of becoming and being a biobank donor and which ethical issues arise in this context. We performed qualitative analysis of 40 qualitative semi-structured interviews with biobank donors and researchers. The results show that relatedness to relatives or other types of close relationships played a significant role in the donors' motivation to be involved in a biobank, risk-benefit assessment, and decisions on sharing information on research and its results. Interviewees mentioned ethical issues in the context of sharing relatives' health-related data for research purposes and returning research findings that may affect their relatives. We conclude that the question of what information on family members may be shared with a biobank by research participants without informed consent of those relatives, and when family members become research subjects, lacks a clear answer and detailed guidelines, especially in the context of the introduction of the European Union's (EU) General Data Protection Regulation. Researchers in Latvia and EU face ethical questions and dilemmas about returning research results and incidental findings to donors' relatives, and donors need more information on sharing research results with relatives in the informed consent process.
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Affiliation(s)
- Signe Mezinska
- Institute of Clinical and Preventive Medicine, University of Latvia, Riga, Latvia
| | - Jekaterina Kaleja
- Institute of Clinical and Preventive Medicine, University of Latvia, Riga, Latvia
| | - Ilze Mileiko
- Institute of Clinical and Preventive Medicine, University of Latvia, Riga, Latvia
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Mezinska S, Kaleja J, Mileiko I, Santare D, Rovite V, Tzivian L. Public awareness of and attitudes towards research biobanks in Latvia. BMC Med Ethics 2020; 21:65. [PMID: 32736554 PMCID: PMC7393882 DOI: 10.1186/s12910-020-00506-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [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: 04/01/2020] [Accepted: 07/16/2020] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Public awareness and engagement are among the main prerequisites for protecting the rights of research participants and for successful and sustainable functioning of research biobanks. The aim of our study was to analyse public awareness and attitudes towards research biobanks in Latvia, and to compare these data with the results of the 2010 Eurobarometer study. We also analysed the influence of awareness and attitudes towards biobanks on willingness to participate in biobank studies and on preferred type of informed consent. METHODS We developed a 12-question survey repeating seven questions about biobanks from the 2010 Eurobarometer questionnaire and adding five others. After describing the study variables, we performed a two-stage analysis of the results. In the first stage we analysed differences between the answers from 2010 and 2019 and conducted univariate analyses of relationships among particular variables, and between those variables and the socio-demographic characteristics of participants. In the second stage we investigated multivariable associations of willingness to participate and type of consent with awareness, trust and the socio-economic characteristics of participants. RESULTS According to our study, the general public in Latvia is still not well informed about research biobanks. Fewer respondents have heard about research biobanks than in 2010. At the same time, the number of respondents who are willing to donate biological samples and personal data to a biobank has increased, e.g. the number of respondents who would definitely or probably be willing to provide information about themselves has increased from 25.8.% to 40.7 since 2010. Overall, concerns about the donation of different types of biological samples and data to a biobank have slightly decreased. CONCLUSIONS Public awareness about biobanks is important for their sustainability. It needs to be increased not only by traditional methods of informing the public, but also by more innovative and participatory approaches, e.g. by citizen science projects. There is a need to strengthen the public visibility and trustworthiness of ethics committees in Latvia in the field of biobanking.
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Affiliation(s)
- S. Mezinska
- Institute of Clinical and Preventive Medicine, University of Latvia, Rainis Boulevard 19, Riga, LV-1586 Latvia
| | - J. Kaleja
- Institute of Clinical and Preventive Medicine, University of Latvia, Rainis Boulevard 19, Riga, LV-1586 Latvia
| | - I. Mileiko
- Institute of Clinical and Preventive Medicine, University of Latvia, Rainis Boulevard 19, Riga, LV-1586 Latvia
| | - D. Santare
- Institute of Clinical and Preventive Medicine, University of Latvia, Rainis Boulevard 19, Riga, LV-1586 Latvia
| | - V. Rovite
- Latvian Biomedical Research and Study Centre, Ratsupites Str. 1-k1, Riga, LV-1067 Latvia
| | - L. Tzivian
- Institute of Clinical and Preventive Medicine, University of Latvia, Rainis Boulevard 19, Riga, LV-1586 Latvia
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Kholodnyuk I, Rivkina A, Hippe L, Svirskis S, Kozireva S, Ventina I, Spaka I, Soloveichika M, Pavlova J, Murovska M, Lejniece S. Chemokine Receptors CCR1 and CCR2 on Peripheral Blood Mononuclear Cells of Newly Diagnosed Patients with the CD38-Positive Chronic Lymphocytic Leukemia. J Clin Med 2020; 9:E2312. [PMID: 32708233 PMCID: PMC7408836 DOI: 10.3390/jcm9072312] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/08/2020] [Accepted: 07/17/2020] [Indexed: 01/29/2023] Open
Abstract
Chemokines and their receptors direct migration and infiltration of immune cells. CCR1 and CCR2 maintain sequence similarity and respond to a number of the same chemokines secreted in lymphoid organs. Expression of CD38 on leukemic cells has been associated with poor clinical outcomes in patients with chronic lymphocytic leukemia (CLL) and is considered as the negative predictor of progression. In our study of newly diagnosed CLL patients, which included 39 CD38-positive and 22 CD38-negative patients, CCR1 and/or CCR2 were always detected, using flow cytometry, on the peripheral blood (PB) CD19+CD5+ lymphocytes in patients with >30% of the CD38+ CD19+CD5+ lymphocytes (n = 16). Spearman's rank correlation analysis determined correlations between the frequency of the CCR1- and CCR2-expressing PB CD19+CD5+ lymphocytes and the frequency of the CD38-positive CD19+CD5+ lymphocytes (rs = 0.50 and rs = 0.38, respectively). No significant correlations were observed between ZAP70 mRNA expression levels in PB mononuclear cells and the frequency of the circulating CCR1+ or CCR2+ CD19+CD5+ lymphocytes. Further association studies are needed to verify prognostic relevance of the CCR1/CCR2 expression on leukemic cells in CLL patients at diagnosis. We suggest that CCR1/CCR2 signaling pathways could represent attractive targets for development of CLL anti-progression therapeutics.
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Affiliation(s)
- Irina Kholodnyuk
- Institute of Microbiology and Virology, Riga Stradins University, Riga LV-1067, Latvia; (L.H.); (S.S.); (S.K.); (I.V.); (I.S.); (J.P.); (M.M.)
| | - Alla Rivkina
- Department of Internal Diseases, Riga Stradins University, Riga LV-1038, Latvia; (A.R.); (S.L.)
- Riga East University Hospital, Clinic of Chemotherapy and Hematology, Riga LV-1038, Latvia;
| | - Laura Hippe
- Institute of Microbiology and Virology, Riga Stradins University, Riga LV-1067, Latvia; (L.H.); (S.S.); (S.K.); (I.V.); (I.S.); (J.P.); (M.M.)
| | - Simons Svirskis
- Institute of Microbiology and Virology, Riga Stradins University, Riga LV-1067, Latvia; (L.H.); (S.S.); (S.K.); (I.V.); (I.S.); (J.P.); (M.M.)
| | - Svetlana Kozireva
- Institute of Microbiology and Virology, Riga Stradins University, Riga LV-1067, Latvia; (L.H.); (S.S.); (S.K.); (I.V.); (I.S.); (J.P.); (M.M.)
| | - Ildze Ventina
- Institute of Microbiology and Virology, Riga Stradins University, Riga LV-1067, Latvia; (L.H.); (S.S.); (S.K.); (I.V.); (I.S.); (J.P.); (M.M.)
| | - Irina Spaka
- Institute of Microbiology and Virology, Riga Stradins University, Riga LV-1067, Latvia; (L.H.); (S.S.); (S.K.); (I.V.); (I.S.); (J.P.); (M.M.)
| | - Marina Soloveichika
- Riga East University Hospital, Clinic of Chemotherapy and Hematology, Riga LV-1038, Latvia;
| | - Jelena Pavlova
- Institute of Microbiology and Virology, Riga Stradins University, Riga LV-1067, Latvia; (L.H.); (S.S.); (S.K.); (I.V.); (I.S.); (J.P.); (M.M.)
| | - Modra Murovska
- Institute of Microbiology and Virology, Riga Stradins University, Riga LV-1067, Latvia; (L.H.); (S.S.); (S.K.); (I.V.); (I.S.); (J.P.); (M.M.)
| | - Sandra Lejniece
- Department of Internal Diseases, Riga Stradins University, Riga LV-1038, Latvia; (A.R.); (S.L.)
- Riga East University Hospital, Clinic of Chemotherapy and Hematology, Riga LV-1038, Latvia;
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Tsuchiya M, Giuliani A, Hashimoto M, Erenpreisa J, Yoshikawa K. Self-Organizing Global Gene Expression Regulated through Criticality: Mechanism of the Cell-Fate Change. PLoS One 2016; 11:e0167912. [PMID: 27997556 PMCID: PMC5173342 DOI: 10.1371/journal.pone.0167912] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 11/22/2016] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND A fundamental issue in bioscience is to understand the mechanism that underlies the dynamic control of genome-wide expression through the complex temporal-spatial self-organization of the genome to regulate the change in cell fate. We address this issue by elucidating a physically motivated mechanism of self-organization. PRINCIPAL FINDINGS Building upon transcriptome experimental data for seven distinct cell fates, including early embryonic development, we demonstrate that self-organized criticality (SOC) plays an essential role in the dynamic control of global gene expression regulation at both the population and single-cell levels. The novel findings are as follows: i) Mechanism of cell-fate changes: A sandpile-type critical transition self-organizes overall expression into a few transcription response domains (critical states). A cell-fate change occurs by means of a dissipative pulse-like global perturbation in self-organization through the erasure of initial-state critical behaviors (criticality). Most notably, the reprogramming of early embryo cells destroys the zygote SOC control to initiate self-organization in the new embryonal genome, which passes through a stochastic overall expression pattern. ii) Mechanism of perturbation of SOC controls: Global perturbations in self-organization involve the temporal regulation of critical states. Quantitative evaluation of this perturbation in terminal cell fates reveals that dynamic interactions between critical states determine the critical-state coherent regulation. The occurrence of a temporal change in criticality perturbs this between-states interaction, which directly affects the entire genomic system. Surprisingly, a sub-critical state, corresponding to an ensemble of genes that shows only marginal changes in expression and consequently are considered to be devoid of any interest, plays an essential role in generating a global perturbation in self-organization directed toward the cell-fate change. CONCLUSION AND SIGNIFICANCE 'Whole-genome' regulation of gene expression through self-regulatory SOC control complements gene-by-gene fine tuning and represents a still largely unexplored non-equilibrium statistical mechanism that is responsible for the massive reprogramming of genome expression.
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Affiliation(s)
- Masa Tsuchiya
- Systems Biology Program, School of Media and Governance, Keio University, Fujisawa, Japan
| | - Alessandro Giuliani
- Environment and Health Department, Istituto Superiore di Sanitá, Rome, Italy
| | - Midori Hashimoto
- Graduate School of Frontier Science, the University of Tokyo, Kashiwa, Japan
| | | | - Kenichi Yoshikawa
- Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan
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Rutkis R, Strazdina I, Balodite E, Lasa Z, Galinina N, Kalnenieks U. The Low Energy-Coupling Respiration in Zymomonas mobilis Accelerates Flux in the Entner-Doudoroff Pathway. PLoS One 2016; 11:e0153866. [PMID: 27100889 PMCID: PMC4839697 DOI: 10.1371/journal.pone.0153866] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 04/05/2016] [Indexed: 11/18/2022] Open
Abstract
Performing oxidative phosphorylation is the primary role of respiratory chain both in bacteria and eukaryotes. Yet, the branched respiratory chains of prokaryotes contain alternative, low energy-coupling electron pathways, which serve for functions other than oxidative ATP generation (like those of respiratory protection, adaptation to low-oxygen media, redox balancing, etc.), some of which are still poorly understood. We here demonstrate that withdrawal of reducing equivalents by the energetically uncoupled respiratory chain of the bacterium Zymomonas mobilis accelerates its fermentative catabolism, increasing the glucose consumption rate. This is in contrast to what has been observed in other respiring bacteria and yeast. This effect takes place after air is introduced to glucose-consuming anaerobic cell suspension, and can be simulated using a kinetic model of the Entner-Doudoroff pathway in combination with a simple net reaction of NADH oxidation that does not involve oxidative phosphorylation. Although aeration hampers batch growth of respiring Z. mobilis culture due to accumulation of toxic byproducts, nevertheless under non-growing conditions respiration is shown to confer an adaptive advantage for the wild type over the non-respiring Ndh knock-out mutant. If cells get occasional access to limited amount of glucose for short periods of time, the elevated glucose uptake rate selectively improves survival of the respiring Z. mobilis phenotype.
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Affiliation(s)
- Reinis Rutkis
- Institute of Microbiology and Biotechnology, University of Latvia, Jelgavas Street 1, Riga, LV-1004, Latvia
| | - Inese Strazdina
- Institute of Microbiology and Biotechnology, University of Latvia, Jelgavas Street 1, Riga, LV-1004, Latvia
| | - Elina Balodite
- Institute of Microbiology and Biotechnology, University of Latvia, Jelgavas Street 1, Riga, LV-1004, Latvia
| | - Zane Lasa
- Institute of Microbiology and Biotechnology, University of Latvia, Jelgavas Street 1, Riga, LV-1004, Latvia
| | - Nina Galinina
- Institute of Microbiology and Biotechnology, University of Latvia, Jelgavas Street 1, Riga, LV-1004, Latvia
| | - Uldis Kalnenieks
- Institute of Microbiology and Biotechnology, University of Latvia, Jelgavas Street 1, Riga, LV-1004, Latvia
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