Hermansenknox4240

A multifaceted study involving focused ion beam scanning electron microscopy techniques, mechanical analysis, water adsorption measurements, and molecular simulations is employed to rationalize the nitric oxide release performance of polyurethane films containing 5, 10, 20, and 40 wt % of the metal-organic framework (MOF) CPO-27-Ni. The polymer and the MOF are first demonstrated to exhibit excellent compatibility. This is reflected in the even distribution and encapsulation of large wt % MOF loadings throughout the full thickness of the films and by the rather minimal influence of the MOF on the mechanical properties of the polymer at low wt %. The NO release efficiency of the MOF is attenuated by the polymer and found to depend on wt % of MOF loading. The formation of a fully connected network of MOF agglomerates within the films at higher wt % is proposed to contribute to a more complex guest transport in these formulations, resulting in a reduction of NO release efficiency and film ductility. An optimum MOF loading of 10 wt % is identified for maximizing NO release without adversely impacting the polymer properties. Bactericidal efficacy of released NO from the films is demonstrated against Pseudomonas aeruginosa, with a >8 log10 reduction in cell density observed after a contact period of 24 h.The respiratory complex I is a gigantic (1 MDa) redox-driven proton pump that reduces the ubiquinone pool and generates proton motive force to power ATP synthesis in mitochondria. Despite resolved molecular structures and biochemical characterization of the enzyme from multiple organisms, its long-range (∼300 Å) proton-coupled electron transfer (PCET) mechanism remains unsolved. We employ here microsecond molecular dynamics simulations to probe the dynamics of the mammalian complex I in combination with hybrid quantum/classical (QM/MM) free energy calculations to explore how proton pumping reactions are triggered within its 200 Å wide membrane domain. Our simulations predict extensive hydration dynamics of the antiporter-like subunits in complex I that enable lateral proton transfer reactions on a microsecond time scale. We further show how the coupling between conserved ion pairs and charged residues modulate the proton transfer dynamics, and how transmembrane helices and gating residues control the hydration process. Our findings suggest that the mammalian complex I pumps protons by tightly linked conformational and electrostatic coupling principles.Eight new diterpenoids (1-8) with varied structures were isolated from the aerial parts of Isodon xerophilus. Among them, xerophilsin A (1) was found to be an unusual meroditerpenoid representing a hybrid of an ent-kauranoid and a long-chain aliphatic ester, xerophilsins B-D (2-4) are dimeric ent-kauranoids, while xerophilsins E-H (5-8) are new ent-kauranoids. The structures of 1-8 were elucidated mainly through the analyses of their spectroscopic data. The absolute configurations of 2, 6, and 8 were confirmed by single-crystal X-ray diffraction, and the configuration of C-16 in 7 was established through quantum chemical calculation of NMR chemical shifts, as well as modeling of key interproton distances. Bioactivity evaluation of all isolated compounds revealed that 2, 3, and 5 inhibited NO production in LPS-stimulated RAW264.7 cells.Rovibrationally excited ephemeral complexes AB**, formed from the association of two molecules A + B, are generally considered to undergo collisions only with an inert bath gas M that transfer energy-inducing termolecular association reactions A + B (+M) → AB (+M). Recent studies have demonstrated that reactive collisions of AB** with a third molecule C-inducing chemically termolecular reactions A + B + C → products-can also be significant in combustion and planetary atmospheres. Previous studies on systems with reactive collisions have primarily focused on limited ranges of reactive collider mole fraction, XC, and pressure, P, specific to the chosen application. Yet, it remains to be established how such systems, and the rate constants of their emergent phenomenological reactions, behave over the wide XC and P ranges of potential interest-a gap in the present understanding that has impeded the development of broadly applicable rate laws and general treatment of such systems in kinetic modeling. Here, we present results from master equation calculations for HO2** formed from H + O2 and its reactions with H to advance understanding and explore representations of systems with reactive colliders across wide ranges of XC and P. With regard to understanding, we demonstrate that reactive collisions can both (1) increase the overall rate of conversion of reactants to products and (2) alter the branching ratio among final products. With regard to representations in kinetic models, we find that rate constants of all emergent phenomenological reactions-termolecular association A + B (+M), chemically termolecular A + B + C, and bimolecular AB + C-exhibit a rich XC and P dependence. We also present analyses to explore the existence of a unique phenomenological representation (or lack thereof) and assess ways for the distinct effects of reactive collisions to be represented in kinetic models.Although metal-phenolic species have emerged as one of the versatile material-independent-coating materials, providing attractive tools for interface engineering, mechanistic understanding of their film formation and growth still remains largely unexplored. Especially, the anions have been overlooked despite their high concentration in the coating solution. Considering that the anions are critical in the reactivity of metal-organic complex and the formation and/or property of functional materials, we investigated the anionic effects on the characteristics of film formation, such as film thickness and properties, in the Fe3+-tannic acid coating. We found that the film characteristics were strongly dictated by the counteranions (e.g., SO42-, Cl-, and Br-) of the Fe3+ ion. Specifically, the film thickness and properties (i.e., mechanical modulus, permeability, and stability) followed the reversed anionic Hofmeister series (Br- > Cl- > SO42-). see more Mechanistic studies suggested that more chaotropic anions, such as Br-, might induce a more widely extended structure of the Fe3+-TA complexes in the coating solution, leading to thicker, harder, but more porous films.