Structural and functional characteristics of sarcoplasmic reticulum vesicles (SRV) from skeletal muscle of normal and hypothyroid rabbits were investigated. The rate of Ca2+ absorption was decreased in hypothyroid animals and Ca2-ATPase activity in SRV of these animals was lower than that of control rabbits. The transport ratio (Ca2+/ATP) in hypothyroid rabbits was higher by 20% than in controls. In SRV of hypothyroid animals a decrease in the protein/lipid interaction and higher fluidity of membrane lipids were observed. Administration of L-thyroxine (300 mg/kg of body mass, intraperitoneally) normalized the SR lipids fluidity within about 40 hrs after the injection but did not affect significantly the patterns of protein/lipid interaction. Normal and hypothyroid SRV were similar in their protein spectrum as shown by electrophoresis in polyacrylamide gel. These alterations observed in the SRV structure and function are apparently related to modifications of membrane lipids.
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Biochemistry
January 2025
Department of Microbiology, Cornell University, Ithaca, New York 14853-8101, United States.
Metal ions are essential for all life. In microbial cells, potassium (K) is the most abundant cation and plays a key role in maintaining osmotic balance. Magnesium (Mg) is the dominant divalent cation and is required for nucleic acid structure and as an enzyme cofactor.
View Article and Find Full Text PDFAm J Sports Med
January 2025
Department of Orthopaedic Surgery, Samsung Medical Center, School of Medicine, Sungkyunkwan University, Seoul, South Korea.
Background: Studies are still limited on the isolated effect of retear after arthroscopic rotator cuff repair (ARCR) on functional outcomes after the midterm period.
Purpose: To assess the effect of retear at midterm follow-up after ARCR and to identify factors associated with the need for revision surgery.
Study Design: Cohort study; Level of evidence, 3.
Biophys J
January 2025
Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Center for Physics and Chemistry of Living Systems, Tel Aviv University, Tel Aviv, Israel. Electronic address:
Migrasomes, the vesicle-like membrane micro-structures, arise on the retraction fibers (RFs), the branched nano-tubules pulled out of cell plasma membranes during cell migration and shaped by membrane tension. Migrasomes form in two steps: a local RF bulging is followed by a protein-dependent stabilization of the emerging spherical bulge. Here we addressed theoretically and experimentally the previously unexplored mechanism of bulging of membrane tubular systems.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Information Materials and Intelligent Sensing Laboratory of Anhui Province, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, 111 Jiu Long Road, Hefei, 230601, China.
Unipolar barrier architecture is designed to enhance the photodetector's sensitivity by inducing highly asymmetrical barriers, a higher barrier for blocking majority carriers to depressing dark current, and a low minority carrier barrier without impeding the photocurrent flow through the channel. Depressed dark current without block photocurrent is highly desired for uncooled Long-wave infrared (LWIR) photodetection, which can enhance the sensitivity of the photodetector. Here, an excellent unipolar barrier photodetector based on multi-layer (ML) graphene (G) is developed, WSe, and PtSe (G-WSe-PtSe) van der Waals (vdW) heterostructure, in which extremely low dark current of 1.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Tissue Engineering and Organ Manufacturing (TEOM) Lab, Department of Biomedical Engineering, Wuhan University TaiKang Medical School (School of Basic Medical Sciences), Wuhan, 430071, China.
Liver organoids have been increasingly adopted as a critical in vitro model to study liver development and diseases. However, the pre-vascularization of liver organoids without affecting liver parenchymal specification remains a long-lasting challenge, which is essential for their application in regenerative medicine. Here, the large-scale formation of pre-vascularized human hepatobiliary organoids (vhHBOs) is presented without affecting liver epithelial specification via a novel strategy, namely nonparenchymal cell grafting (NCG).
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