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In addition to its biological importance, DPhPC lipid bilayers are widely used in droplet bilayers, study of integral membrane proteins, drug delivery systems as well as patch-clamp electrophysiology of ion channels, yet their mechanical properties are not fully measured. Herein, we examined the effect of the ether linkage on the mechanical properties of ester- and ether-DPhPC lipid bilayers using all-atom molecular dynamics simulation. The values of area per lipid, thickness, intrinsic lateral pressure profile, order parameter, and elasticity moduli were estimated using various computational frameworks and were compared with available experimental values. Overall, a good agreement was observed between the two. The global properties of the two lipid bilayers are vastly different, with ether bilayer being stiffer, less ordered, and thicker than ester bilayer. Moreover, ether linkage decreased the area per lipid in the ether lipid bilayer. Our computational framework and output demonstrate how ether modification changes the mechano-chemical properties of DPhPC bilayers. [ABSTRACT FROM AUTHOR]

Abstract The magnetic properties of tetragonal structure of stoichiometric NiMn alloy is investigated using density functional theory within the local spin density approximation. The system studied here, is a free standing film. The effect of thickness and epitaxial strain on the magnetic and structural properties is examined. It is found that while the magnetic moments of Mn surface atoms vary depending on the number of layers being odd (3.60 μ B) or even (3.55 μ B) the magnitude of the magnetic moment for surface Ni atoms is constant (0.11 μ B). By applying epitaxial strain on the slabs, it was observed, for the first time, that the magnetic phase of NiMn films changes from "A-type-like" ferrimagnetic for compressive strains to "G-type-like" ferrimagnetic for tensile strains. Highlights • Effect of thickness and epitaxial strain on the magnetic structure of NiMn films are investigated. • Surface buckling phenomenon for different thicknesses is studied. • A magnetic phase transition from A-type-like ferrimagnetic to G-type-like ferrimagnetic was observed by applying epitaxial strain. [ABSTRACT FROM AUTHOR]

Through this research, functionalized graphene nanopores are used to verify how effective such an apparatus for DNA sequencing is. The circular symmetric pores are functionalized with hydrogen and a hydroxyl group bonded with carbon atoms of the pore rim. Plus, two adenine bases are also put at the rim perimeter to verify whether such a combination would lead to base detection. A homopolymer of single-stranded DNA (ssDNA) is pulled through a nanopore using steered molecular dynamics (SMD) simulation. Pulling force profile, moving fashion of ssDNA in irreversible DNA pulling as well as the base orientation during translocation relative to the graphene plane, called beta angle, are assessed. Based on the studied parameters, SMD force, and base orientation, the hydrogenated and hydroxylated pores do not show a clear distinction between bases, while the adenine-functionalized pore can distinguish between adenine and cytosine. Therefore, there may be some hope for achieving single-base sequencing, while further research is needed. [Display omitted] • A single-strand DNA was pulled through the functionalized nanopores using steered molecular dynamics simulation. • The functionalized graphene nanopores were used to verify how effective such an apparatus for DNA sequencing is. • Solid-state circular symmetric hydrogenated/hydroxylated/adenine-decorated nanopores lead to base detection. • Our results show that the adenine-functionalized pore can distinguish between adenine and cytosine. [ABSTRACT FROM AUTHOR]

The martensitic phase transformation in stoichiometric NiMn alloy and its shape memory effect is investigated using first principles method based on Density Functional Theory (DFT). The elastic properties of the B2 austenite and the L1 0 martensite phases were compared and the results indicated that the B2 phase has a low elastic shear modulus along the [110] direction giving rise to the formation of L1 0. Electronic density of states (DOS) calculations showed that the existence of the pseudo-gap appearing at the Fermi level which stabilizes the martensite phase against the austenite depends on both magnetism and the tetragonality ratio. Using geometrically nonlinear theory of martensite it was found that large volume change and twinning shear, and the low value of middle eigenvalue of the transformation stretch tensor (λ 2 = 0.8766) are some of the properties of the martensitic transformation in NiMn which inhibit the shape memory effect in this system despite being structurally similar to other shape memory alloys such as NiAl. The effect of the addition of 8 alloying elements on the martensitic transformation and shape memory effect is investigated. The results showed, in agreement with the experimental findings, that addition of Ti and Al can improve the shape memory effect. Also, it was found that among the 8 elements considered here, Al, Ti, and Ge are the most effective alloying elements in enhancing the shape memory properties of NiMn by lowering the transformation temperature, decreasing the volume change, and increasing the value of λ 2.. • The dependence of the pseudogap on both magnetic structure and tetragonality was examined. • Large variation of the lattice parameters with temperature hinders the complete shape memory effect. • The effect of ternary alloying elements on the martensitic transformation is studied. [ABSTRACT FROM AUTHOR]