In this study a total of 186 complex halide systems were collected; the formabilities of ABX3 (X = F, Cl, Br and I) halide perovskites were investigated using the empirical structure map, which was constructed by Goldschmidt's tolerance factor and the octahedral factor. A model for halide perovskite formability was built up. In this model obtained, for all 186 complex halides systems, only one system (CsF-MnF2) without perovskite structure and six systems (RbF-PbF2, CsF-BeF2, KCl-FeCl2, TlI-MnI2, RbI-SnI2, TlI-PbI2) with perovskite structure were wrongly classified, so its predicting accuracy reaches 96%. It is also indicated that both the tolerance factor and the octahedral factor are a necessary but not sufficient condition for ABX3 halide perovskite formability, and a lowest limit of the octahedral factor exists for halide perovskite formation. This result is consistent with our previous report for ABO3 oxide perovskite, and may be helpful to design novel halide materials with the perovskite structure.

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The physical properties of lipid bilayers are sensitive to the specific type and composition of the lipids that make up the many different types of cell membranes. Studying model bilayers of representative heterogeneous compositions can provide key insights into membrane functionality. In this work, we use atomistic molecular dynamics simulations to characterize key properties in a number of bilayer membranes of varying composition. We first examine basic properties, such as lipid area, volume, and bilayer thickness, of simple, homogeneous bilayers comprising several lipid types, which are prevalent in biological membranes. Such lipids are then used in simulations of heterogeneous systems representative of bacterial, mammalian, and cancer membranes. Our analysis is especially focused on depth-dependent, transmembrane profiles; in particular, we calculate lateral pressure and dipole potential profiles, two fundamental properties which play key roles in a large number of biological functions.

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In recent years, biodegradable magnesium alloys emerge as a new class of biomaterials for tissue engineering and medical devices. Deploying biodegradable magnesium-based materials not only avoids a second surgical intervention for implant removal but also circumvents the long-term foreign body effect of permanent implants. However, these materials are often subjected to an uncontrolled and fast degradation, acute toxic responses and rapid structural failure presumably due to a localized, too rapid corrosion process. The patented Mg–Nd–Zn–based alloys (JiaoDa BioMg [JDBM]) have been developed in Shanghai Jiao Tong University in recent years. The alloy series exhibit lower biodegradation rate and homogeneous nanophasic degradation patterns as compared with other biodegradable Mg alloys. The in vitro cytotoxicity tests using various types of cells indicate excellent biocompatibility of JDBM. Finally, bone implants using JDBM-1 alloy and cardiovascular stents using JDBM-2 alloy have been successfully fabricated and in vivo long-term assessment via implantation in animal model have been performed. The results confirmed the reduced degradation rate in vivo, excellent tissue compatibility and long-term structural and mechanical durability. Thus, this novel Mg-alloy series with highly uniform nanophasic biodegradation represent a major breakthrough in the field and a promising candidate for manufacturing the next generation biodegradable implants.

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We present a new dual-resolution approach for coupling atomistic and coarse-grained models in molecular dynamics simulations of hydrated systems. In particular, a coarse-grained point dipolar water model is used to solvate molecules represented with standard all-atom force fields. A unique characteristic of our methodology is that the mixing of resolutions is direct, meaning that no additional or ad hoc scaling factors, intermediate regions, or extra sites are required. To validate the methodology, we compute the hydration free energy of 14 atomistic small molecules (analogs of amino acid side chains) solvated by the coarse-grained water. Remarkably, our predictions reproduce the experimental data as accurately as the predictions from state-of-the-art fully atomistic simulations. We also show that the hydration free energy of the coarse-grained water itself is in comparable or better agreement with the experimental value than the predictions from all but one of the most common multisite atomistic models. The coarse-grained water is then applied to solvate a typical atomistic protein containing both α-helix and β-strand elements. Moreover, parallel tempering simulations are performed to investigate the folding free energy landscape of a representative α helical and a β hairpin structure. For the simulations considered in this work, our dual-resolution method is found to be 3 to 6 times more computationally efficient than corresponding fully atomistic approaches.