An ab initio density functional theory method (DFT) with D3 dispersion corrections (DFT-D3) was employed to study the 64 possible models of structure hectorite intercalated tetramethylammonium (TMA) cations aim find additional information about for energetically most suitable mutual arrangement TMA cations. The complex analysis total energies showed small differences among structural lowest (L ...

The effect of interactions of various Ia and IIa cations with two positions of the adenine-thymine (A-T) and guanine-cytosine (G-C) base pairs on the geometries and individual hydrogen bond (HB) energies have been investigated by using the atoms in molecules (AIM) method at the B3LYP/6-311++G(d,p) level of theory. The cations that possess higher charge/radius (q/rad) ratio make higher changes o...

The in vitro cytotoxicity of nine metal cations common in dental casting alloys was evaluated using Balb/c 3T3 fibroblasts and four toxicity parameters: total protein production, 3H-leucine incorporation, 3H-thymidine incorporation, and MTT-formazan production. Concentrations causing 50% toxicity compared to controls (TC50's) and reversibility of these effects were determined. The range of pote...

We have studied the properties of the prototype hybrid organic-inorganic perovskite CH3NH3PbI3 using relativistic density functional theory (DFT). For our analysis we introduce the concept of CH3NH + 3 “pair modes”, that is, characteristic relative orientations of two neighboring CH3NH + 3 cations. In our previous work [Phys. Rev. B 94, 045201(2016)] we identified two preferential orientations ...

in this study, we assessed the relative contribution of organic and inorganic solutes to osmotic adjustment (oa) in three almond rootstocks subjected to four levels of soil salinity. the results showed that leaf water and osmotic potentials were affected by salinity in gf677 and bitter almond, but less so in gn15, suggesting a higher selectivity for k+ and ca2+ against na+ in this latter rootst...

increasing urbanisation and industrialisation have led to a dramatic reduction in forest area, and now only culturally protected remnants of natural forests and some new plantations remain in most areas of the north of iran. to investigate the status of the chemical and physical characteristics of soil under these remnant forests and assess the possible impacts of reforestation on soil properti...

The mechanism by which bi-and trivalent cations affect human liver phosphatidatephosphohydrolase (PAP) activity was investigated. Bivalent cations up to 1 mM increased PAP activity whereas at higher concentrations the activity of the enzyme decreased. The stimulatory concentration for trivalent cations such as Al3+ and Cr3+, however, was much lower being 2 m M and 1 m M, respectively. All catio...