Flexible cross-linked anion exchange membranes (AEMs) based on poly (-phenylene oxide) grafted with -spirocyclic quaternary ammonium cations were synthesized via UV-induced free-radical polymerization by using diallylpiperidinium chloride as an ionic monomer. Five membranes with ion exchange capacity (IEC) varying between 1.5 to 2.8 mmol Cl·g polymer were obtained and the correlation between IEC, water uptake, state of water in the membrane and ionic conductivity was studied. In the second part of this study, the influence of properties of four of these membranes on cell cycling stability and performance was investigated in an aqueous organic redox flow battery (AORFB) employing dimethyl viologen (MV) and ,,-2,2,6,6-heptamethylpiperidinyl oxy-4-ammonium chloride (TMA-TEMPO). The influence of membrane properties on cell cycling stability and performance was studied. At low-current density (20 mA·cm), the best capacity retention was obtained with lower IEC membranes for which the water uptake, freezable water and TMA-TEMPO and MV crossover are low. However, at a high current density (80 mA·cm), membrane resistance plays an important role and a membrane with moderate IEC, more precisely, moderate ion conductivity and water uptake was found to maintain the best overall cell performance. The results in this work contribute to the basic understanding of the relationship between membrane properties and cell performance, providing insights guiding the development of advanced membranes to improve the efficiency and power capability for AORFB systems.
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http://dx.doi.org/10.3390/membranes11050367 | DOI Listing |
Chem Rev
January 2025
Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York 14853, United States.
Cells contain thousands of different lipids. Their rapid and redundant metabolism, dynamic movement, and many interactions with other biomolecules have justly earned lipids a reputation as a vexing class of molecules to understand. Further, as the cell's hydrophobic metabolites, lipids assemble into supramolecular structures─most commonly bilayers, or membranes─from which they carry out myriad biological functions.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Institute for Regenerative Medicine, State Key Laboratory of Cardiology and Medical Innovation Center, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, 200123, P. R. China.
Human amniotic epithelial cells (hAECs) have shown excellent efficacy in clinical research and have prospective applications in the treatment of many diseases. However, the properties of the hAECs and their proliferative mechanisms remain unclear. Here, single-cell RNA sequencing (scRNA-seq) is performed on hAECs obtained from amniotic tissues at different gestational ages and passages during in vitro culture.
View Article and Find Full Text PDFMicrosc Microanal
January 2025
Cellular and Molecular Biotechnology Research Institute, Department of Life Science and Biotechnology, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central-6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan.
There is still room for improvement in the isolation and purification techniques for extracellular vesicles (EVs), particularly in the separation of exosomes (small EVs) from other membrane vesicles such as microvesicles and apoptotic bodies. Furthermore, it is crucial to establish preparation methods that preserve the intrinsic properties of EVs in this context. In this study, we focus on the isolation and preparation of small EVs, exosomes, from the culture supernatant of a human cell line.
View Article and Find Full Text PDFNanoscale
January 2025
James Watt School of Engineering, University of Glasgow, Glasgow G12 8QQ, UK.
Neurodegenerative diseases, characterized by the progressive deterioration of neuronal function and structure, pose significant global public health and economic challenges. Brain-Derived Neurotrophic Factor (BDNF), a key regulator of neuroplasticity and neuronal survival, has emerged as a critical biomarker for various neurodegenerative and psychiatric disorders, including Alzheimer's disease. Traditional diagnostic methods, such as Enzyme-Linked Immunosorbent Assay (ELISA) and electrochemiluminescence (ECL) assays, face limitations in terms of sensitivity, stability, reproducibility, and cost-effectiveness.
View Article and Find Full Text PDFActa Physiol (Oxf)
February 2025
Faculty of Medicine, University of Maribor, Maribor, Slovenia.
Background: The crucial steps in beta cell stimulus-secretion coupling upon stimulation with glucose are oscillatory changes in metabolism, membrane potential, intracellular calcium concentration, and exocytosis. The changes in membrane potential consist of bursts of spikes, with silent phases between them being dominated by membrane repolarization and absence of spikes. Assessing intra- and intercellular coupling at the multicellular level is possible with ever-increasing detail, but our current ability to simultaneously resolve spikes from many beta cells remains limited to double-impalement electrophysiological recordings.
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