Spectral measurements of the H(α) Balmer series line and the continuum radiation are applied to draw inferences of electron density, temperature, and the level of self-absorption in laser ablation of a solid ice target in ambient air. Electron densities of 17 to 3.2×10(24) m(-3) are determined from absolute calibrated emission coefficients for time delays of 100-650 ns after generation of laser plasma using Q-switched Nd:YAG radiation. The corresponding temperatures of 4.5-0.95 eV were evaluated from the absolute spectral radiance of the continuum at the longer wavelengths. The redshifted, Stark-broadened hydrogen alpha line emerges from the continuum radiation after a time delay of 300 ns. The electron densities inferred from power law formulas agree with the values obtained from the plasma emission coefficients.
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http://dx.doi.org/10.1364/OL.40.003436 | DOI Listing |
Sci Rep
January 2025
Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization, Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains, College of Biology and Agricultural Resources, Hubei Zhongke Research Institute of Industrial Technology, Huanggang Normal University, Huanggang, 438000, Hubei, China.
Yutangba, situated in Enshi City, Hubei Province, is globally noted for its high selenium (Se) content. Soil invertebrates are essential to the functionality and services of terrestrial ecosystems, yet their community composition in this region remains under-explored. This study utilized environmental DNA metabarcoding to investigate the interrelations among environmental factors, soil invertebrate diversity, and community characteristics concerning soil Se content, pH, and moisture content in the region.
View Article and Find Full Text PDFNature
January 2025
Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA, USA.
Carbon-hydrogen (C-H) bonds are the foundation of essentially every organic molecule, making them an ideal place to do chemical synthesis. The key challenge is achieving selectivity for one particular C(sp)-H bond. In recent years, metalloenzymes have been found to perform C(sp)-H bond functionalization.
View Article and Find Full Text PDFBiochim Biophys Acta Mol Cell Res
January 2025
Graduate School of Semiconductor and Chemical Engineering, Jeonbuk National University, 567 Baekje-daero, Deokjin-Gu, Jeonju, Jeonbuk 54896, South Korea. Electronic address:
Senescence significantly contributes to aging in various tissues, influenced by factors such as lysosomal alkalinization, which disrupts autophagic flux and accumulates toxic substances. This disruption leads to oxidative stress, increased lysosomal permeability, cellular senescence, and apoptosis. Similar to mammalian lysosomes, S.
View Article and Find Full Text PDFJ Biol Chem
January 2025
Department of Chemistry, The University of Texas at San Antonio, Texas 78249, United States. Electronic address:
MarE, a heme-dependent enzyme, catalyzes a unique 2-oxindole-forming monooxygenation reaction from tryptophan metabolites. To elucidate its enzyme-substrate interaction mode, we present the first X-ray crystal structures of MarE in complex with its prime substrate, (2S,3S)-β-methyl-L-tryptophan and cyanide at 1.89 Å resolution as well as a truncated yet catalytically active version in complex with the substrate at 2.
View Article and Find Full Text PDFBioorg Chem
January 2025
Department of Chemistry, St Berchmans College (Autonomous), Changanassery, Kerala 686101, India; Centre for Theoretical and Computational Chemistry, St Berchmans College (Autonomous), Changanassery, Kerala 686101, India. Electronic address:
In this study, three novel derivatives of benzo[b]thiophene-2-carbaldehyde (BTAP1, BTAP2, and BTAP3) were successfully synthesized and comprehensively characterized using spectroscopic techniques including FTIR, UV-VIS, HNMR, and CNMR. Thermal analysis through TGA and DTA demonstrated remarkable thermal stability with a maximum threshold at 270 °C. Spectroscopic investigations revealed π → π* transitions in all compounds, attributed to the conjugated system comprising benzothiophene rings connected to bromophenyl/ aminophenyl/phenol rings via α, β-unsaturated ketone bridges.
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