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INTRODUCTION: A revision of several experimental results on cells shows that electromagnetic radiation, either produced by biofield therapy (BFT) or laser, induced an increase in intracellular free calcium concentration. An explanation of this phenomenon is proposed. METHODS: Quantum chemistry calculations were performed on Ca2+ with different degrees of hydration with the DFT/r2SCAN-3c method together with the implicit solvation model SMD. RESULTS: Ca2+ dehydration energy by quantum calculations, in an aqueous medium, coincides with the experimental results of the energy of the photon emitted in biofield therapies and lasers. This strongly suggests that the increased intracellular free calcium concentration is because of calcium ion dehydration upon the application of radiation. The Ca2+ dehydration increases the membrane potential due to an augment of the net charge on Ca2+ and it moves near the membrane by the attraction of its negative ions. The voltage-dependent channels are also activated by this membrane potential. CONCLUSION: The increased intracellular Ca2+ concentration occurs with biofield therapy (BFT) or laser. A novel explanation is given based on resonance-induced Ca2+ dehydration with applied radiation, supported by experimental data and theoretical calculations.

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Magnesium sulfate (MgSO4) has been used as a protector agent for many diseases related to oxidative stress. The effect of MgSO4 on the oxidized lipid bilayer has not yet been studied using molecular dynamics calculations. In this work, the effects of oxidation were evaluated by using a POPC membrane model at different concentrations of its aldehyde (-CHO) and hydroperoxide (-OOH) derivatives with and without MgSO4. Several quantitative and qualitative properties were evaluated, such as membrane thickness, area per lipid, area compressibility modulus, snapshots after simulation finish, density distributions, time evolutions of oxidized group positions, and radial distributions of oxidized group concerning Mg. Results indicate that in the absence of MgSO4 the mobility of oxidized groups, particularly -CHO, toward the surface interface is high. At a low oxidation level of the bilayer there is an increase in the compressibility modulus as compared to the unoxidized bilayer. MgSO4, at a low oxidation level, tends to lessen the oxidation effects by lowering the dispersion in the distribution of oxidized species toward the membrane surface and the water region. However, MgSO4 does not change the trends of decreasing membrane thickness and area compressibility modulus and increasing area per lipid upon oxidation. In this regard, MgSO4 diminishes the electrostatic long-distance attractive interactions between the oxidized groups and the charged headgroups of the interface, owing to the Mg+2 and SO4 -2 screening effects and an electrostatic stabilization of the headgroups, preventing the pore formation, which is well-known to occur in oxidized membranes.

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Aging processes of black carbon (BC) particles require knowledge of their chemical reactivities, which have impact on cloud condensation nuclei (CCN) activities, radiant properties and health problems related to air pollutions. In the present work, interactions between several OH radicals with BC (modeled with a coronene molecule) were calculated by using DFT and PM6 codes as described by Mysak et al. Water interaction with BC was also included. Results show that OH radical adsorption is preferred on border sites, independent of the theoretical method employed. Potential energy curves using DFT(TPSS-D3) approach for OH chemisorption showed small-energy barriers, as reported in previous work with PM6. A dipole moment has been created, and the hydrophobic coronene surface is transformed to hydrophilic after the first OH chemisorption. Several stages were found in the BC aging by OH radicals, thus (a) Hydroxylation of coronene by several OH radical would lead to H abstractions directly from the substrate. (b) Abstraction of H from adsorbed OH (at the border sites) drives a C-C bond breaking and the formation of carboxyl groups. (c) Hydrogen abstraction from carboxyl group produces decarboxylation (CO2 plus water) as experimentally obtained. Potential energy curves of one of the reactive path were calculated with the PM6 method. The formation of products was confirmed using DFT. Coronene interaction with O2 was also considered to have a realistic atmospheric environment.

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The role of entropic effects in methane distribution and transport in silicalite zeolites is studied using molecular dynamics in the limit of infinite dilution or small loading. Diffusive behavior and its anisotropy is assessed as a function of temperature where we find both an Arrhenius regime above 250 K and deviations thereof below such temperature. Using a previous probabilistic model, geometrical correlations or memory effects are evidenced and are shown to be enhanced as temperature is reduced. Deviations from Arrhenius behavior are concomitant with entropic effects. We find that, the preference of methane towards presence at intersections or channel centers changes at a threshold temperature. A discrete transition is found from a channel-center preferred phase, at low temperatures, versus an intersection preferred phase at high temperatures with evidence of hysteresis effects. Such entropic effects are also reflected, in diffusive transport, as non-Arrhenius-type behavior. A model based on accessible volume as a function of energy agrees with the simulated transition lending new insight into zeolite cavity design.