Recent experimental results for covalent glasses suggest the existence of an intermediate phase attributed to the self-organization of the glass network resulting from the tendency to minimize its internal stress. However, the exact nature of this experimentally measured phase remains unclear. We modified a previously proposed model of self-organization by generating a uniform sampling of stress-free networks. In our model, studied on a diluted triangular lattice, an unusual intermediate phase appears, in which both rigid and floppy networks have a chance to occur, a result also observed in a related model on a Bethe lattice by Barré et al[Phys. Rev. Lett. 94, 208701 (2005)]. Our results for the bond-configurational entropy of self-organized networks, which turns out to be only about 2% lower than that of random networks, suggest that a self-organized intermediate phase could be common in systems near the rigidity percolation threshold.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevE.74.016116 | DOI Listing |
J Chromatogr A
December 2024
Downstream Processing, Bioprocessing Technology Institute (BTI), Agency for Science, Technology and Research (A*STAR), 20 Biopolis Way, Centros #06-01 138668, Singapore. Electronic address:
Given the complexities of continuous bioprocessing, it is critical to thoroughly investigate the process parameters unique to multi-column chromatography (MCC) and their potential impacts. However, existing studies have focused on either loading densities or residence time at steady states only, and their combined impact on critical quality attributes (CQAs) especially during transient phases were less known. In this study, we investigated the impact of critical process parameters during both steady-state and transient phases (start-up, close-down, and intermediate perturbation) through full factorial design.
View Article and Find Full Text PDFArch Toxicol
January 2025
Department of Pharmacy and Pharmaceutical Sciences, National University of Singapore, 18 Science Drive 4, Singapore, 117543, Singapore.
Psilocin is a well-studied controlled substance with potential psychotherapeutic applications. However, research gaps remain regarding its metabolism. Our objective was to elucidate a comprehensive Phase I metabolic profile of psilocin to support its forensic management and clinical development.
View Article and Find Full Text PDFJ Mol Model
January 2025
Laboratorio de Química Teórica Computacional (QTC), Facultad de Química y de Farmacia, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, 7820436, Santiago de Chile, Chile.
Context: Dopamine -monooxygenase (D M) is an essential enzyme in the organism that regioselectively converts dopamine into R-norepinephrine, the key step of the reaction, studied in this paper, is a hydrogen atom transfer (HAT) from dopamine to a superoxo complex on D M, forming a hydroperoxo intermediate and dopamine radical. It was found that the formation of a hydrogen bond between dopamine and the D M catalyst strengthens the substrate-enzyme interaction and facilitates the HAT which takes place selectively to give the desired enantiomeric form of the product. Six reactions leading to the hydroperoxo intermediate were analyzed in detail using theoretical and computational tools in order to identify the most probable reaction mechanism.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Seoul National University, School of Medicine, Seoul, Korea, Republic of (South).
Background: We herein introduce a case that was pathologically confirmed as an advanced stage of LATE.
Method: (case presentation) An 81-year-old woman visited a memory clinic complaining of memory impairment in the past few years. She had no psychiatric history and a history of significant hyperlipidemia and hypertension.
J Chem Phys
January 2025
Department of Chemistry, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati, Andhra Pradesh 517619, India.
Although impurities are unavoidable in real-world and experimental systems, most numerical studies on nucleation focus on pure (impurity-free) systems. As a result, the role of impurities in phase transitions remains poorly understood, especially for systems with complex free energy landscapes featuring one or more intermediate metastable phases. In this study, we employed Monte Carlo simulations to investigate the effects of static impurities (quenched disorder) of varying length scales and surface morphologies on the crystal nucleation mechanism and kinetics in the Gaussian core model system-a representative model for soft colloidal systems.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!