Supercharged Proteins and Polypeptides

Electrostatic interactions play a vital role in nature. Biomacromolecules such as proteins are orchestrated by electrostatics, among other intermolecular forces, to assemble and organize biochemistry. Natural proteins with a high net charge exist in a folded state or are unstructured and can be an inspiration for scientists to artificially supercharge other protein entities. Recent findings show that supercharging proteins allows for control of their properties such as temperature resistance and catalytic activity. One elegant method to transfer the favorable properties of supercharged proteins to other proteins is the fabrication of fusions. Genetically engineered, supercharged unstructured polypeptides (SUPs) are just one promising fusion tool. SUPs can also be complexed with artificial entities to yield thermotropic and lyotropic liquid crystals and liquids. These architectures represent novel bulk materials that are sensitive to external stimuli. Interestingly, SUPs undergo fluid–fluid phase separation to form coacervates. These coacervates can even be directly generated in living cells or can be combined with dissipative fiber assemblies that induce life-like features. Supercharged proteins and SUPs are developed into exciting classes of materials. Their synthesis, structures, and properties are summarized. Moreover, potential applications are highlighted and challenges are discussed.     

Theoretical investigation of anisotropic mechanical and thermal properties of ABO3 (A=Sr,Ba; B=Ti,Zr, Hf) perovskites

As promising TBC (thermal barrier coating) candidates, perovskite oxides own designable properties for their various options of cations and structural diversity, but limited comprehensions of structure‐property relationship delay their engineering applications. In this work, mechanical/thermal properties of ABO₃ (A=Sr, Ba; B=Ti, Zr, Hf) perovskites and their anisotropic nature are predicted employing density functional theory. Their theoretical minimum thermal conductivities range from 1.09 to 1.74 W·m^?1·K^?1, being lower than Y₂O₃ partially stabilized ZrO₂. Reduced thermal conductivities up to 16% along particular directions are reached after considering thermal conductivity anisotropy. All compounds own high hardness while SrZrO₃, SrHfO₃, and BaHfO₃ possess well damage tolerance. We found that small electronegativity discrepancy leads to big anisotropy of chemical bond, Young's/shear moduli and thermal conductivities, together with good damage tolerance. These results suggest that the next generation TBCs with extra low thermal conductivity should be achieved through combining material design and orientation‐growth tailoring.     

Possible origin of ferromagnetism in antiferromagnetic orthorhombic-YFeO3: A first-principles study

Rare-earth orthoferrites (RFeO₃) are well-known for the antiferromagnetic ground state. However, some of the recent experimental results suggest that the few members of RFeO₃ family possess ferromagnetism. In the present investigation we report the possible origin of ferromagnetism in antiferromagnetic YFeO₃ using density functional theory. For this purpose, we have considered pure as well as self-doping in YFeO₃ i.e. by considering the point defect at Y, Fe and O sites. Our finding suggests that the point defects in YFeO₃ results in the mixed-valence state of Fe, which may result in ferromagnetism through Zener double exchange mechanism.     

蔓越莓中膳食纤维的结构性质和功能性质研究

目的 考察蔓越莓中膳食纤维的结构性质和功能性质。方法 利用酶解法提取蔓越莓总膳食纤维、不溶性膳食纤维和可溶性膳食纤维, 并采用红外光谱和高效液相色谱测定其官能团结构和分子量, 采用质构仪和粘度计测定其凝胶性质和粘度, 同时对膳食纤维吸附亚硝酸根离子、交换阳离子、胆固醇、重金属和葡萄糖的能力进行研究。结果 总膳食纤维和不溶性膳食纤维的提取率较高, 分别为54.67%和38.70%, 膳食纤维具有凝胶和粘度的性质, 同时在功能上有吸附亚硝酸根离子, 交换阳离子, 吸收胆固醇, 重金属离子和葡萄糖的性能。结论 蔓越莓膳食纤维具有特殊的结构性质和很好的功能活性, 可以开发蔓越莓新功能食品。     

Functional Causality between Oil Prices and GDP Based on Big Data

This paper examines the causal relationship between oil prices and the Gross Domestic Product (GDP) in the Kingdom of Saudi Arabia. The study is carried out by a data set collected quarterly, by Saudi Arabian Monetary Authority, over a period from 1974 to 2016. We seek how a change in real crude oil price affects the GDP of KSA. Based on a new technique, we treat this data in its continuous path. Precisely, we analyze the causality between these two variables, i.e., oil prices and GDP, by using their yearly curves observed in the four quarters of each year. We discuss the causality in the sense of Granger, which requires the stationarity of the data. Thus, in the first Step, we test the stationarity by using the Monte Carlo test of a functional time series stationarity. Our main goal is treated in the second step, where we use the functional causality idea to model the co-variability between these variables. We show that the two series are not integrated; there is one causality between these two variables. All the statistical analyzes were performed using R software.     

回收废旧电池制备功能材料研究进展

废旧电池中含有大量的金属物质，如果不妥善处理，会造成严重的环境污染和资源浪费。而将废旧电池回收之后用于制备功能材料，既能有效解决废旧电池难处置、危害大的问题，又可以减少功能材料的制备成本。文章首先概述了电池的组成及种类、废旧电池的回收意义与回收和处理现状；其次重点介绍了回收废旧电池制备功能材料的研究现状和最新进展，根据废旧电池制备功能材料所采用回收工艺的不同对废旧电池的回收利用进行了分类；最后探讨了目前回收废旧电池制备功能材料所存在的一些问题，并指出简单处理废旧电池制备功能材料将会是未来的主要发展趋势。     

Direct Growth of Germanene at Interfaces between Van der Waals Materials and Ag(111)

Germanene, a 2D honeycomb germanium crystal, is grown at graphene/Ag(111) and hexagonal boron nitride (h-BN)/Ag(111) interfaces by segregating germanium atoms. A simple annealing process in N₂ or H₂/Ar at ambient pressure leads to the formation of germanene, indicating that an ultrahigh-vacuum condition is not necessary. The grown germanene is stable in air and uniform over the entire area covered with a van der Waals (vdW) material. As an important finding, it is necessary to use a vdW material as a cap layer for the present germanene growth method since the use of an Al₂O₃ cap layer results in no germanene formation. The present study also proves that Raman spectroscopy in air is a powerful tool for characterizing germanene at the interfaces, which is concluded by multiple analyses including first-principles density functional theory calculations. The direct growth of h-BN-capped germanene on Ag(111), which is demonstrated in the present study, is considered to be a promising technique for the fabrication of future germanene-based electronic devices.