Hong Liu

Bio: Hong Liu is an academic researcher from Shandong University. The author has contributed to research in topics: Medicine & Materials science. The author has an hindex of 100, co-authored 1905 publications receiving 57561 citations. Previous affiliations of Hong Liu include Shanghai University & Guangzhou University.

Engineering mammalian cytochrome P450 2B1 by directed evolution for enhanced catalytic tolerance to temperature and dimethyl sulfoxide

Abstract: The previously laboratory-evolved cytochrome P450 2B1 quadruple mutant V183L/F202L/L209A/S334P (QM), which showed enhanced H(2)O(2)-mediated substrate oxidation, has now been shown to exhibit a >3.0-fold decrease in K(m,HOOH) for 7-ethoxy-4-trifluoromethylcoumarin (7-EFC) O-deethylation compared with the parental enzyme L209A. Subsequently, a streamlined random mutagenesis and a high-throughput screening method were developed using QM to screen and select mutants with enhanced tolerance of catalytic activity to temperature and dimethyl sulfoxide (DMSO). Upon screening >3000 colonies, we identified QM/L295H and QM/K236I/D257N with enhanced catalytic tolerance to temperature and DMSO. QM/L295H exhibited higher activity than QM at a broad range of temperatures (35-55 degrees C) and maintained approximately 1.4-fold higher activity than QM at 45 degrees C for 6 h. In addition, QM/L295H showed a significant increase in T(m,app) compared with L209A. QM/L295H and QM/K236I/D257N exhibited higher activity than QM at a broad range of DMSO concentrations (2.5-15%). Furthermore, QM/K236I/D257N/L295H was constructed by combining QM/K236I/D257N with L295H using site-directed mutagenesis and exhibited a >2-fold higher activity than QM at nearly the entire range of DMSO concentrations. In conclusion, in addition to engineering mammalian cytochromes P450 for enhanced activity, directed evolution can also be used to optimize catalytic tolerance to temperature and organic solvent.

Highly efficient and stable perovskite solar cells via bilateral passivation layers

Abstract: NiOx-based perovskite solar cells (PSCs) have drawn tremendous attention and achieved significant improvement in recent years. Interfacial engineering is a promising route for enhancing performances of PSCs with larger open-circuit voltage (VOC) and short-circuit current density (JSC). Herein, we report a simple method for improving the performance of PSCs by applying bilateral polystyrene layers between the perovskite absorber and charge transport layers, respectively. The top and bottom surfaces of the perovskite layer are passivated and protected by ultrathin bilateral polystyrene layers, which results in highly efficient devices with a larger perovskite grain size, fewer interfacial defects and suppressed charge recombination. As a result, a power conversion efficiency (PCE) of 19.99% is achieved without hysteresis and the VOC is as high as 1.149 V, which is so far the best result for p–i–n PSCs based on pure CH3NH3PbI3. Moreover, the devices also show improved long-term stability. This study provides a powerful strategy to design and prepare highly efficient and stable perovskite solar cells.

Nanostructured titanate with different metal ions on the surface of metallic titanium: a facile approach for regulation of rBMSCs fate on titanium implants.

Abstract: Titanium (Ti) is widely used for load-bearing bio-implants, however, it is bio-inert and exhibits poor osteo-inductive properties. Calcium and magnesium ions are considered to be involved in bone metabolism and play a physiological role in the angiogenesis, growth, and mineralization of bone tissue. In this study, a facile synthesis approach to the in situ construction of a nanostructure enriched with Ca(2+) and Mg(2+) on the surface of titanium foil is proposed by inserting Ca(2+) and Mg(2+) into the interlayers of sodium titanate nanostructures through an ion-substitution process. The characteriz 0.67, and 0.73 nm ation results validate that cations can be inserted into the interlayer regions of the layered nanostructure without any obvious change of morphology. The cation content is positively correlated to the concentration of the solutions employed. The biological assessments indicate that the type and the amount of cations in the titanate nanostructure can alter the bioactivity of titanium implants. Compared with a Na(+) filled titanate nanostructure, the incorporation of divalent ions (Mg(2+) , Ca(2+) ) can effectively enhance protein adsorption, and thus also enhance the adhesion and differentiation ability of rat bone-marrow stem cells (rBMSCs). The Mg(2+) /Ca(2+) -titanate nanostructure is a promising implantable material that will be widely applicable in artificial bones, joints, and dental implants.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

The chemistry of two-dimensional layered transition metal dichalcogenide nanosheets

Abstract: Ultrathin two-dimensional nanosheets of layered transition metal dichalcogenides (TMDs) are fundamentally and technologically intriguing. In contrast to the graphene sheet, they are chemically versatile. Mono- or few-layered TMDs - obtained either through exfoliation of bulk materials or bottom-up syntheses - are direct-gap semiconductors whose bandgap energy, as well as carrier type (n- or p-type), varies between compounds depending on their composition, structure and dimensionality. In this Review, we describe how the tunable electronic structure of TMDs makes them attractive for a variety of applications. They have been investigated as chemically active electrocatalysts for hydrogen evolution and hydrosulfurization, as well as electrically active materials in opto-electronics. Their morphologies and properties are also useful for energy storage applications such as electrodes for Li-ion batteries and supercapacitors.