In this work, an investigation of supercritical water is presented combining inelastic and deep inelastic neutron scattering experiments and molecular dynamics simulations based on a machine-learned potential of quality. The local hydrogen dynamics is investigated at 250 bar and in the temperature range of 553-823 K, covering the evolution from subcritical liquid to supercritical gas-like water. The evolution of libration, bending, and stretching motions in the vibrational density of states is studied, analyzing the spectral features by a mode decomposition. Moreover, the hydrogen nuclear momentum distribution is measured, and its anisotropy is probed experimentally. It is shown that hydrogen bonds survive up to the higher temperatures investigated, and we discuss our results in the framework of the coupling between intramolecular modes and intermolecular librations. Results show that the local potential affecting hydrogen becomes less anisotropic within the molecular plane in the supercritical phase, and we attribute this result to the presence of more distorted hydrogen bonds.
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http://dx.doi.org/10.1021/acs.jpclett.0c02547 | DOI Listing |
Curr Pharm Des
January 2025
Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Erciyes University, Kayseri 38039, Turkey.
Background: Psychosis, marked by detachment from reality, includes symptoms like hallucinations and delusions. Traditional herbal remedies like kratom are gaining attention for psychiatric conditions. This was aimed at comprehending the molecular mechanisms of Kratom's antipsychotic effects utilizing a multi-modal computational approach.
View Article and Find Full Text PDFBioresour Bioprocess
January 2025
Qingdao Innovation Institute of East China University of Science and Technology, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China.
Cephalosporin C (CPC) is a critical raw material for cephalosporin antibiotics produced by Acremonium chrysogenum. During fermentation, the oxygen supply is a crucial factor limiting the efficient biosynthesis of CPC. This study demonstrated that the addition of exogenous surfactants significantly increased the dissolved oxygen (DO) level, extracellular catalase content, and final CPC titer.
View Article and Find Full Text PDFNat Microbiol
January 2025
Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA.
As freshwater lakes undergo rapid anthropogenic change, long-term studies reveal key microbial dynamics, evolutionary shifts and biogeochemical interactions, yet the vital role of viruses remains overlooked. Here, leveraging a 20 year time series from Lake Mendota, WI, USA, we characterized 1.3 million viral genomes across time, seasonality and environmental factors.
View Article and Find Full Text PDFTalanta
December 2024
Department of Pathology, College of Medicine, King Khalid University, Asir, 61421, Saudi Arabia; Forensic Medicine and Clinical Toxicology Department, Mansoura University, Egypt. Electronic address:
Complexing medications with cyclodextrins can enhance their solubility and stability. In this study, we investigated the host-guest complexation between Tetrahydrocurcumin (THC) and Hydroxypropyl-β-Cyclodextrin (HP-β-CD) using density functional theory (DFT) at the B3LYP-D3/TPZ level of theory in two possible orientations. To determine the reactive sites in both complexes for electrophilic and nucleophilic attacks, we calculated and interpreted the binding energy, HOMO and LUMO orbitals, global chemical reactivity descriptors, natural bond orbital (NBO) analysis, and Fukui indices.
View Article and Find Full Text PDFJ Proteome Res
January 2025
Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States.
Proteo-SAFARI is a shiny application for fragment assignment by relative isotopes, an R-based software application designed for identification of protein fragment ions directly in the / domain. This program provides an open-source, user-friendly application for identification of fragment ions from a candidate protein sequence with support for custom covalent modifications and various visualizations of identified fragments. Additionally, Proteo-SAFARI includes a nonnegative least-squares fitting approach to determine the contributions of various hydrogen shifted fragment ions ( + 1, + 1, - 1, - 2) observed in UVPD mass spectra which exhibit overlapping isotopic distributions.
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