Search results for "dynamics"

AM1 prediction of the equilibrium geometry of Si60

1993

Abstract AM1 calculations have been carried out to determine the equilibrium geometry of Si 60 . The predicted I h geometry shows that bonds may be clearly identified as single (2.297 A) or aromatic (2.092 A). Several analogies and differences between Si 60 and C 60 are pointed out. Especially remarkable is the bigger size of the Si 60 cluster, which is predicted to have a radius 2 A larger than that of the C 60 cluster. Results are compared to other levels of theory.

Comparison of various CI treatments for the description of potential curves for the lowest three states of O2

1972

Abstract Various ab initio CI treatments are reported for the 3 Σ − g , 1 Δ g and 1 Σ + g states of O 2 with particular emphasis on the agreement obtained between calculated and experimental results for binding energies and bond distances of these species and also for transition energies between them. The utility of off-center s and p gaussians in describing the bonding process is stressed and the possibility of optimizing the configurations used in the calculations at each internuclear distance is considered.

Resolving Binding Events on the Multifunctional Human Serum Albumin

2020

Abstract Physiological processes rely on initial recognition events between cellular components and other molecules or modalities. Biomolecules can have multiple sites or mode of interaction with other molecular entities, so that a resolution of the individual binding events in terms of spatial localization as well as association and dissociation kinetics is required for a meaningful description. Here we describe a trichromatic fluorescent binding‐ and displacement assay for simultaneous monitoring of three individual binding sites in the important transporter and binding protein human serum albumin. Independent investigations of binding events by X‐ray crystallography and time‐resolved dyn…

Encapsulation capacity and natural payload delivery of an anticancer drug from boron nitride nanotube.

2016

The behavior of confined anticancer carboplatin (CPT) molecules in a single (10, 10) boron nitride nanotube (BNNT) was studied by means of molecular dynamics simulations. Our study revealed a very large storage capacity of BNNT. Analysis of the energy profiles depending on the number of confined molecules, and on their spatial organization allowed us to quantify the ability of BNNT to vectorize CPT. Indeed, BNNT despite its small radius presented a large inner volume that favored stable encapsulation of multiple active anticancer molecules. Moreover, in our molecular dynamics simulations, the empty BNNT and the BNNT filled with CPT diffused spontaneously to the cell membrane and were able t…

Boundary Element Formulation for Unified Analysis of High-Speed Trains

2007

Progressive Development of Renal Vascular Dysfunction in Brain Death Implicates Reversible Alterations of Nitric Oxide Metabolism

2011

Vascular endothelial dysfunction occurs in the kidney graft from marginal brain death (BD) donors and may be responsible for a low success rate after transplantation.BD was induced in 16 dogs for 6 hours. Immediately after the inflation of the intracranial balloon, the treated group (n = 8) received 40 mg/kg bolus followed by 3 mg/kg/min infusion of L-arginine for 30 minutes. Renal vascular function and hemodynamic and biochemical parameters were determined.BD caused vasoconstriction, increase in renal venous nitrite (4.9 ± 0.8 versus 2.6 ± 0.1, P.05) and myeloperoxidase levels (1.43 ± 0.04 versus 2.43 ± 0.23, P.001), and reduced vasodilatation of renal artery to acetylcholine. Larginine di…

The selective estrogen receptor modulator, bazedoxifene, reduces ischemic brain damage in male rat

2014

While the estrogen treatment of stroke is under debate, selective estrogen receptor modulators (SERMs) arise as a promising alternative. We hypothesize that bazedoxifene (acetate, BZA), a third generation SERM approved for the treatment of postmenopausal osteoporosis, reduces ischemic brain damage in a rat model of transient focal cerebral ischemia. For comparative purposes, the neuroprotective effect of 17β-estradiol (E2) has also been assessed. Male Wistar rats underwent 60min middle cerebral artery occlusion (intraluminal thread technique), and grouped according to treatment: vehicle-, E2- and BZA-treated rats. Optimal plasma concentrations of E2 (45.6±7.8pg/ml) and BZA (20.7±2.1ng/ml) w…

Measuring High-Order Interactions in Rhythmic Processes Through Multivariate Spectral Information Decomposition

2021

Many complex systems in physics, biology and engineering are modeled as dynamical networks and described using multivariate time series analysis. Recent developments have shown that the emergent dynamics of a network system are significantly affected by interactions involving multiple network nodes which cannot be described using pairwise links. While these higher-order interactions can be probed using information-theoretic measures, a rigorous framework to describe them in the frequency domain is still lacking. This work presents an approach for the spectral decomposition of multivariate information measures, capable of identifying higher-order synergistic and redundant interactions betwee…

Biowaiver Monograph for Immediate-Release Solid Oral Dosage Forms: Moxifloxacin Hydrochloride.

2020

Abstract In this monograph, literature data is reviewed to evaluate the feasibility of waiving in vivo bioequivalence testing and instead applying the Biopharmaceutics Classification System (BCS) based methods to the approval of immediate-release solid oral dosage forms containing moxifloxacin hydrochloride as the sole active pharmaceutical ingredient. To facilitate the feasibility decision, solubility and permeability and dissolution characteristics in the context of the BCS, therapeutic index, therapeutic use, pharmacokinetic parameters, bioequivalence/bioavailability issues, drug-excipient interactions and other relevant data were taken into consideration. Moxifloxacin is a BCS class I d…

The Catalytic Mechanism of Steroidogenic Cytochromes P450 from All-Atom Simulations: Entwinement with Membrane Environment, Redox Partners, and Post-…

2019

Cytochromes P450 (CYP450s) promote the biosynthesis of steroid hormones with major impact on the onset of diseases such as breast and prostate cancers. By merging distinct functions into the same catalytic scaffold, steroidogenic CYP450s enhance complex chemical transformations with extreme efficiency and selectivity. Mammalian CYP450s and their redox partners are membrane-anchored proteins, dynamically associating to form functional machineries. Mounting evidence signifies that environmental factors are strictly intertwined with CYP450s catalysis. Atomic-level simulations have the potential to provide insights into the catalytic mechanism of steroidogenic CYP450s and on its regulation by e…