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We propose a simple approach to investigate the structural relaxation time and glass transition of amorphous drugs. Amorphous materials are modeled as a set of equal sized hard spheres. The structural relaxation time over many decades in hard-sphere fluids is theoretically calculated using the elastically collective nonlinear Langevin equation theory associated with Kramer's theory. Then, new thermal mapping from a real material to an effective hard-sphere fluid provides temperature-dependent relaxation time, which can be compared to experiments. Numerical results quantitatively agree with previous experiments for pharmaceutical binary mixtures having different weight ratios. We carry out experiments to test our calculations for an ezetimibe-simvastatin-Kollidon VA64 mixture. Our approach would provide a simple but comprehensive description of glassy dynamics in amorphous composites.
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http://dx.doi.org/10.1021/acs.molpharmaceut.9b00230 | DOI Listing |
Event-based sensors (EBS), with their low latency and high dynamic range, are a promising means for tracking unresolved point-objects. Conventional EBS centroiding methods assume the generated events follow a Gaussian distribution and require long event streams ($\gt 1$s) for accurate localization. However, these assumptions are inadequate for centroiding unresolved objects, since the EBS circuitry causes non-Gaussian event distributions, and because using long event streams negates the low-latency advantage of EBS.
View Article and Find Full Text PDFAppl Psychophysiol Biofeedback
September 2025
Florida State University, Tallahassee, USA.
The explanation for how acutely stressful experiences could result in proximal health outcomes has been lacking in occupational health research. Although scholars have argued that individual personality and affect could worsen health behaviors, we believe that these qualities also could intensify the experience of acute stressors, potentially explaining why acutely stress encounters result in poor health outcomes for some people, but not others. Our study examines three individual differences - worry, negative affect, and positive affect - that are relevant to differential stress anticipation, reactivity, and recovery.
View Article and Find Full Text PDFJ Chem Phys
September 2025
Jülich Centre for Neutron Science (JCNS-1), Forschungszentrum Jülich GmbH, 52428 Jülich, Germany.
The static and dynamic properties of a cyclic Rouse chain modified by the introduction of an effective, spherically symmetric, attracting potential of entropic nature are studied. It is shown that a relatively weak potential can lead to a strong contraction of the polymer chain: the radius of gyration becomes much smaller compared to the size of the free cyclic chain. The pronounced decrease in the terminal relaxation time of cyclic macromolecules in the presence of a harmonic potential compared to the Rouse relaxation time leads to a lengthening of the time interval for the transition to the normal, i.
View Article and Find Full Text PDFJ Chem Phys
September 2025
Department of Chemistry, University of Rochester, Rochester, New York 14627, USA.
We introduce an efficient method, TTN-HEOM, for exactly calculating the open quantum dynamics for driven quantum systems interacting with highly structured bosonic baths by combining the tree tensor network (TTN) decomposition scheme with the bexcitonic generalization of the numerically exact hierarchical equations of motion (HEOM). The method yields a series of quantum master equations for all core tensors in the TTN that efficiently and accurately capture the open quantum dynamics for non-Markovian environments to all orders in the system-bath interaction. These master equations are constructed based on the time-dependent Dirac-Frenkel variational principle, which isolates the optimal dynamics for the core tensors given the TTN ansatz.
View Article and Find Full Text PDFFront Hum Neurosci
August 2025
Signal Processing Laboratory (LTS5), École Polytechnique Féderale de Lausanne (EPFL), Lausanne, Switzerland.
Introduction: Absence of language development is a condition encountered across a large range of neurodevelopmental disorders, including a significant proportion of children with autism spectrum disorder. The neurobiological underpinnings of non-verbal ASD (nvASD) remain poorly understood.
Methods: This study employed multimodal MRI to investigate white matter (WM) microstructural abnormalities in nvASD, focusing on language-related pathways.