Effects of temperature and Na0+ on the relaxation of guinea-pig ureter smooth muscle were studied. Relaxation of phasic contraction was found to be highly temperature-dependent, practically independent of Na0+ and Ca02+, and resistant to vanadate. The relaxation of the tonic tension of both high-K and low-Na contracture was less temperature-dependent and affected by Na0+. The relaxation of tonic tension produced by introduction of Na0+ was about 3-5 times faster than that produced by Ca-free solution. La3+ ions were found to block the relaxation of the tonic component of the Na+-free contracture initiated by removal of Ca02+. Three systems of regulation of cell calcium are suggested to be operative in the ureter muscle: a fast one which is highly temperature-dependent and responsible for the relaxation of the phasic contraction (probably the sarcoplasmic reticulum), and two slow membrane-linked carriers, one of which is dependent on Na0+ (probably Na-Ca exchange) and another one which is independent of Na0+ and inhibited by La3+ (probably Ca-pump).
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January 2025
Astronomical Observatory, Jagiellonian University, Orla 171, Krakow, 30-244, Poland.
The single crystals of lead-free NaBiTiO were grown using the Czochralski method. The energy gaps determined from X-ray photoelectron spectroscopy (XPS) and optical measurements were approximately 2.92 eV.
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January 2025
MOE Key Laboratory for UV Light-Emitting Materials and Technology, Department of Physics, Northeast Normal University, Changchun, Jilin 130024, PR China; Faculty of Chemistry, Northeast Normal University, Changchun, Jilin 130024, PR China. Electronic address:
Considering factors such as crustal reserves, atomic mass, redox potential and energy density, sodium-ion batteries (SIBs) are regarded as the most promising alternative to lithium-ion batteries (LIBs). Transition metal-based layered oxides, especially typical NaMnO, stand out among cathode materials due to their low cost and high energy density. However, NaMnO cathodes face several challenges, including Jahn-Teller distortion, manganese dissolution, structural collapse, irreversible phase transition and significant capacity loss.
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July 2024
Applied Physics and Radiation Technologies Group, CCDCU, School of Engineering and Technology, Sunway University, Bandar Sunway, 47500, Selangor, Malaysia.
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View Article and Find Full Text PDFSmall
November 2023
Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
Lead-free dielectric ceramics with excellent energy-storage performance are crucial to the development of the next-generation advanced pulse power capacitors. However, low energy-storage density limits the evolution of capacitors toward lightweight, miniaturization, and integration. Here, an effective strategy of constructing highly dynamic polarization heterogeneous nanoregions is proposed in lead-free relaxors to realize an ultrahigh energy-storage density of ≈8.
View Article and Find Full Text PDFACS Omega
July 2023
Department of Physics, Guru Nanak Dev University, Amritsar 143005, Punjab, India.
This research study examines the high-temperature dielectric relaxation and electric conduction mechanisms in ()LaCoO-(1 - )NaBiTiO samples, where is 0.05, 0.10, and 0.
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