At the Drosophila melanogaster larval neuromuscular junction (NMJ), a motor neuron releases glutamate from 30-100 boutons onto the muscle it innervates. How transmission strength is distributed among the boutons of the NMJ is unknown. To address this, we created synapcam, a version of the Ca2+ reporter Cameleon. Synapcam localizes to the postsynaptic terminal and selectively reports Ca2+ influx through glutamate receptors (GluRs) with single-impulse and single-bouton resolution. GluR-based Ca2+ signals were uniform within a given connection (that is, a given bouton/postsynaptic terminal pair) but differed considerably among connections of an NMJ. A steep gradient of transmission strength was observed along axonal branches, from weak proximal connections to strong distal ones. Presynaptic imaging showed a matching axonal gradient, with higher Ca2+ influx and exocytosis at distal boutons. The results suggest that transmission strength is mainly determined presynaptically at the level of individual boutons, possibly by one or more factors existing in a gradient.
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http://dx.doi.org/10.1038/nn1526 | DOI Listing |
Micron
December 2024
Department of Chemical and Materials Engineering, The University of Auckland, New Zealand. Electronic address:
This study investigates the effect of pre-deformation by cold rolling after solution annealing on the microstructure and properties of the fine-grained Al-Li alloy 2A97. Electron backscatter diffraction (EBSD), X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to characterize grain boundaries, dislocations, precipitates and calculate their contribution to strength. It is found that the changes in precipitation behavior predominantly account for the enhanced tensile properties observed in the deformed alloys, where yield and tensile strengths are increased by 85 MPa and 63 MPa, respectively.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
Hebei Provincial Key Laboratory of Power Transmission Equipment Security Defense, North China Electric Power University, Baoding 071003, China.
Epoxy resin (EP) is an outstanding polymer material known for its low cost, ease of preparation, excellent electrical insulation properties, mechanical strength, and chemical stability. It is widely used in high- and ultra-high-voltage power transmission and transformation equipment. However, as voltage levels continue to increase, EP materials are gradually failing to meet the performance demands of operational environments.
View Article and Find Full Text PDFJ Funct Biomater
November 2024
Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Department of Biomedical Engineering, College of Chemistry and Life Sciences, Beijing University of Technology, Beijing 100124, China.
The cross-linking process of collagen is one of the more important ways to improve the mineralization ability of collagen. However, the regulatory effect of dynamic cross-linking on biomineralization in vitro remains unclear. Dynamic-cross-linked mineralized collagen under different cross-linking processes, according to the process of cross-linking and mineralization of natural bone, was prepared in this study.
View Article and Find Full Text PDFGels
December 2024
College of Pharmacy and Inje Institute of Pharmaceutical Sciences and Research, Inje University, 197 Inje-ro, Gimhae 50834, Republic of Korea.
The objective of this work was to develop a supersaturated gel formulation (SGF) loaded with the maximum atorvastatin calcium trihydrate (ATR) dose. The maximum dose strength of ATR needs to be reduced through improving solubility and dissolution rate to mitigate side effects due to the necessity of taking high doses. ATR has highly pH-dependent solubility at 37 °C, leading to poor solubility (<10 μg/mL) in stomach acid (pH 1.
View Article and Find Full Text PDFPharm Dev Technol
December 2024
Nanomedicine Research Group, Department of Pharmacy, Quaid-i-Azam University, Islamabad 45320, Pakistan.
This study aims to develop a thermoresponsive biomaterial system of irinotecan (IRT) and curcumin (CUR) nano-transferosomal gel (IRT-CUR-NTG) for targeting colorectal cancer (CRC). The IRT-CUR-NTs were statistically optimized and loaded into poloxamer-based thermosensitive gel. Transmission electron microscopy (TEM), Differential scanning calorimetry (DSC) and Fourier-transform infrared spectroscopy (FTIR) of the IRT-CUR-NTs were performed, whereas pH, gelation time, gelation temperature, gel and mucoadhesive strength of the IRT-CUR-NTG were investigated.
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