Laser-induced breakdown spectroscopy (LIBS) has been applied mainly to bulk analysis of solids, liquids, and gases and less frequently for elemental microanalysis of solid surfaces. A micro-LIBS device devoted to analysis of the distribution of elements on surfaces is described. This device offers rapid access with a 3-microm spatial resolution to the microchemical structures of both conductive and nonconductive samples. Quantitative microchemical results of applications to ceramics are reported. By the use of a time-resolved acquisition spectrum, cerium in a uranium matrix was characterized with a cerium detection limit of 1.14%. Calibration curves obtained with manipulations during 1 year facilitated evaluations of reproducibility and repeatability. A 2% single-shot repeatability with a calibration reproducibility of approximately 7% is reported.
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http://dx.doi.org/10.1364/ao.42.006063 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390.
Neurotransmitter release is triggered in microseconds by Ca-binding to the Synaptotagmin-1 C-domains and by SNARE complexes that form four-helix bundles between synaptic vesicles and plasma membranes, but the coupling mechanism between Ca-sensing and membrane fusion is unknown. Release requires extension of SNARE helices into juxtamembrane linkers that precede transmembrane regions (linker zippering) and binding of the Synaptotagmin-1 CB domain to SNARE complexes through a "primary interface" comprising two regions (I and II). The Synaptotagmin-1 Ca-binding loops were believed to accelerate membrane fusion by inducing membrane curvature, perturbing lipid bilayers, or helping bridge the membranes, but SNARE complex binding through the primary interface orients the Ca-binding loops away from the fusion site, hindering these putative activities.
View Article and Find Full Text PDFPLoS One
January 2025
College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China.
Background: As an opportunistic bacterial pathogen, Klebsiella pneumoniae (KP) is prone to causing a spectrum of diseases in rabbits when their immune system is compromised, which poses a threat to rabbit breeding industry. Bacillus coagulans (BC), recognized as an effective probiotic, confers a variety of benefits including anti-inflammatory and antioxidant properties.
Aim: The purpose of this study was to investigate whether dietary BC can effectively alleviate hepatic injury caused by KP.
Clin J Am Soc Nephrol
January 2025
Post-graduate Program in Medical Sciences: Endocrinology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Cells
December 2024
Biotechnology Research and Innovation Council-National Institute of Biomedical Genomics, Kalyani 741251, West Bengal, India.
Breast cancer is a cancer with global prevalence and a surge in the number of cases with each passing year. With the advancement in science and technology, significant progress has been achieved in the prevention and treatment of breast cancer to make ends meet. The scientific intradisciplinary subject of "metabolomics" examines every metabolite found in a cell, tissue, system, or organism from different sources of samples.
View Article and Find Full Text PDFAnal Methods
January 2025
Department of Health Technology, Technical University of Denmark, 2800 Kgs, Lyngby, Denmark.
Antibiotic tolerance presents a significant challenge in eradicating bacterial infections, as tolerant strains can survive antibiotic treatment, contributing to the recurrence of infections and the development of resistance. However, unlike antibiotic resistance, tolerance is not detectable by standard susceptibility assays such as minimal inhibitory concentration (MIC) tests. Consequently, antibiotic tolerance often goes unnoticed in clinical settings.
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