Hua Zhang

Bio: Hua Zhang is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Medicine & Graphene. The author has an hindex of 163, co-authored 1503 publications receiving 116769 citations. Previous affiliations of Hua Zhang include Shenzhen University & Zhengzhou University.

In Situ Synthesis of Metal Sulfide Nanoparticles Based on 2D Metal-Organic Framework Nanosheets

Abstract: A facile in situ synthetic method is developed to synthesize metal sulfide nanoparticles based on 2D M-TCPP (M = Cu, Cd, or Co, TCPP = tetrakis(4-carboxyphenyl)porphyrin)) metal-organic framework nanosheets. The obtained CuS/Cu-TCPP composite nanosheet is used as the active material in photoelectrochemical cells, showing notably increased photocurrent due to the improved exciton separation and charge carrier transport.

Expanding the Genetic Code for Photoclick Chemistry in E. coli, Mammalian Cells, and A. thaliana

Abstract: Bioorthogonal chemical reactions together with techniques to expand the genetic code have provided exciting new means for protein labeling and visualization in living systems, as well as for optimizing the efficacy of therapeutic proteins. Toward these goals, amino acids with small bioorthogonal functional groups, such as azide, alkyne, or cyclopropene moieties, as well as larger reactive bioorthogonal groups, such as cyclooctyne, norbornene, trans-cyclooctene, aryltetrazole, or aryltetrazine, have been site-specifically incorporated into proteins, allowing for selective conjugation of biophysical probes through azide–alkyne click chemistry (AAC), tetrazole–alkene photoclick chemistry (TAP), and reverse-electron demand Diels–Alder reactions. The main advantages of the photoclick reaction (Supporting Information, Scheme S1) are: 1) its fast rate (up to 50m 1 s ); 2) that spatiotemporal control is initiated by a photo-induced reaction; 3) that the photoclick reaction is fluorogenic, allowing for high-contrast fluorescence imaging without tedious washing steps. In previous studies, we reported the site-specific incorporation of p-(2-tetrazole)phenylalanine (p-Tpa) and N-e-(1-methylcycloprop-2-enecarboxamido)lysine (CpK) in E. coli and mammalian cells. Subsequent photoirradiation of labeled proteins with UV light facilitates selective conjugation with dimethyl fumarate or diaryltetrazole, respectively. By expanding the genetic code and introducing photoclick chemistry to plants, important problems in plant chemical biology can be addressed, such as photosynthesis and stress response, which can only be studied at the organismal level. Recently, expansion of the genetic code has been used to optimize therapeutic proteins produced in bacteria and mammalian cells. Because plants offer an attractive alternative to microbial fermentation and animal cell cultures for high-yield production of recombinant proteins on an agricultural scale, expanding the genetic code in plants would be useful for producing recombinant therapeutic proteins and enzymes with enhanced properties, better safety, and lower costs. To fully realize the potential of photoclick reaction for tracking fast cellular processes, it is desirable that the unnatural amino acid (UAA) used has a small functional group such that there is minimal perturbation of the target protein, and a very brief exposure to long-wavelength UV light or violet-blue light is used to drive the photoclick reaction to minimize damage to cells and plants. Herein, we addressed these issues by genetically incorporating N-eacryllysine (AcrK, Figure 1A), in response to an amber stop codon (TAG) in bacterial cells, mammalian cells, and plants. This new strategy was then used to efficiently label proteins both in vitro and in vivo. In comparison to lysine, AcrK has only four extra non-hydrogen atoms, which is significantly less than other UAAs. Replacing one lysine residue with AcrK should cause only minimal perturbation to the target protein. In addition, the electron-withdrawing amido group should activate the terminal alkene group to achieve a higher photoclick reaction rate. Indeed, the photoclick reaction between tetrazole and acrylamide was found to proceed nearly one hundred times faster than that of allylphenylether and 1.5 times faster than that of cyclopropene. AcrK was synthesized by reacting N-a-Boc-lysine with acryloyl chloride in a basic ethyl acetate/water solution at 0 8C (Figure 1A), followed by deprotection with HCl gas with an overall yield of 72%, without the need for metal catalysts. AcrK was found to be relatively stable in the presence of glutathione, an abundant biomolecule both amine and thiol groups; greater than 95% of AcrK remained following incubation with 5 mm reduced glutathione in a buffer at pH 7 for 24 hours (Figure S1). At neutral pH, most primary amines are protonated and most thiols are neutral. Therefore, glutathione could react slowly with the acrylamido group through a Michael addition reaction. While AcrK has comparable stability to CpK under physiological conditions, the synthetic route for CpK requires six steps, expensive heavy metal catalysis, with an overall yield of 15%. Because a large amount of the UAA is required for modifying plant proteins on an agricultural scale, it is essential that the UAA is synthesized in an economically, without the use of toxic heavy-metal catalysts. We chose diaryltetrazole 2 (Figure 1B) because it is highly reactive for photoclick reactions and is soluble in water. Because the molar extinction coefficients of 2 at 365 nm and 405 nm are around 100m 1 cm 1 (Figure S2) and the quantum yields for the photolysis of diaryltetrazoles are very high (0.5– 0.9), 2 should be efficiently activated by long-wavelength UV light or violet light. An amine functional group provides a convenient handle for further derivatization. Upon irradi[*] F. H. Li, H. Zhang, Y. Sun, Y. C. Pan, J. Z. Zhou, Prof. Dr. J. Y. Wang Laboratory of Non-coding RNA, Institute of Biophysics Chinese Academy of Sciences 15 Datun Road, Chaoyang District, Beijing, 100101 (China) E-mail: jwang@ibp.ac.cn [] These authors contributed equally to this work.

Liquid-phase growth of platinum nanoparticles on molybdenum trioxide nanosheets: an enhanced catalyst with intrinsic peroxidase-like catalytic activity

Abstract: A facile method for the synthesis of metal nanostructure-decorated two-dimensional (2D) semiconductor nanosheets was developed. The solution-processable molybdenum trioxide (MoO3) nanosheet was used as a template for direct liquid-phase growth of platinum nanoparticles (Pt NPs) under ambient conditions. Results show that the Pt NPs with sizes of 1-3 nm were uniformly grown on the MoO3 surface. Importantly, the Pt-MoO3 hybrid nanomaterial exhibits an enhanced peroxidase-like catalytic activity compared to the MoO3 nanosheet, Pt NPs, and their physical mixture under the same conditions. As a proof-of-concept application, the Pt-MoO3 hybrid nanomaterial was used as a high-efficiency peroxidase-mimic for ultrasensitive colorimetric detection of glucose in serum samples. This work provides a promising strategy for design and development of biomimetic catalysts by smart assembly of different dimensional nanomaterials.

MoS2-coated vertical graphene nanosheet for high-performance rechargeable lithium-ion batteries and hydrogen production

Abstract: Hybrid nanostructures composed of vertical graphene nanosheet (VGNS) and MoS2 nano-leaves are synthesized by the chemical vapor deposition method followed by a solvothermal process. The unique three-dimensional nanostructures of MoS2/VGNS arranged in a vertically aligned manner can be easily constructed on various substrates, including Ni foam and graphite paper. Compared with MoS2/carbon black, MoS2/VGNS nanocomposites grown on Ni foam exhibit enhanced electrochemical performance as the anode material of lithium-ion batteries, delivering a specific capacity of 1277[thinsp]mAh[thinsp]g-1 at a current density of 100[thinsp]mA[thinsp]g-1 and a high first-cycle coulombic efficiency of 76.6%. Moreover, the MoS2/VGNS nanostructures also retain a capacity of 1109[thinsp]mAh[thinsp]g-1 after 100 cycles at a current density of 200[thinsp]mA[thinsp]g-1, suggesting excellent cycling stability. In addition, when the MoS2/VGNS nanocomposites grown on graphite paper are applied in the hydrogen evolution reaction, a small Tafel slope of 41.3[thinsp]mV dec-1 and a large double-layer capacitance of 7.96[thinsp]mF[thinsp]cm-2 are obtained, which are among the best values achievable by MoS2-based hybrid structures. These results demonstrate the potential applications of MoS2/VGNS hybrid materials for energy conversion and storage and may open up a new avenue for the development of vertically aligned, multifunctional nanoarchitectures.

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 …

Fast parallel algorithms for short-range molecular dynamics

Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

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。

Electronics and optoelectronics of two-dimensional transition metal dichalcogenides.

Abstract: Single-layer metal dichalcogenides are two-dimensional semiconductors that present strong potential for electronic and sensing applications complementary to that of graphene.