载体仿真设备的设计与实现

针对目前光电实验室各项目在研制阶段对载体信息的要求,研究并实现了一种载体仿真设备。该设备采用光电载体平台(舰艇、战斗机、战车)物理运动特性为仿真模型,以该仿真模型为核心,通过模拟和数字2种接口输出光电载体的运动轨迹和姿态等信息,通过仿真软件可在线修改振幅和周期等姿态和振动参数。实验表明各项功能与技术指标均满足实验室使用要求。

Impaired suppressive activities of human MUTYH variant proteins against oxidative mutagenesis

AIM:To investigate the suppressive activity of MUTYH variant proteins against mutations caused by oxidative lesion,8-hydroxyguanine(8OHG),in human cells.METHODS:p.R154H,p.M255V,p.L360P,and p.P377L MUTYH variants,which were previously found in patients with colorectal polyposis and cancer,were selected for use in this study.Human H1299 cancer cell lines inducibly expressing wild-type(WT) MUTYH(type 2) or one of the 4 above-mentioned MUTYH variants were established using the piggyBac transposon vector system,enabling the genomic integration of the transposon sequence for MUTYH expression.MUTYH expression was examined after cumate induction using Western blotting analysis and immunofluorescence analysis.The intracellular localization of MUTYH variants tagged with FLAG was also immunofluorescently examined.Next,the mutation frequency in the supF of the shuttle plasmid pMY189 containing a single 8OHG residue at position 159 of the supF was compared between empty vector cells and cells expressing WT MUTYH or one of the 4 MUTYH variants using a supF forward mutation assay.RESULTS:The successful establishment of human cell lines inducibly expressing WT MUTYH or one of the 4 MUTYH variants was concluded based on the detection of MUTYH expression in these cell lines after treatment with cumate.All of the MUTYH variants and WT MUTYH were localized in the nucleus,and nuclear localization was also observed for FLAG-tagged MUTYH.The mutation frequency of supF was 2.2 × 10-2 in the 8OHG-containing pMY189 plasmid and 2.5 × 10-4 in WT pMY189 in empty vector cells,which was an 86-fold increase with the introduction of 8OHG.The mutation frequency(4.7 × 10-3) of supF in the 8OHG-containing pMY189 plasmid in cells overexpressing WT MUTYH was significantly lower than in the empty vector cells(P < 0.01).However,the mutation frequencies of the supF in the 8OHG-containing pMY189 plasmid in cells overexpressing the p.R154H,p.M255V,p.L360P,or p.P377L MUTYH variant were 1.84 × 10-2,1.55 × 10-2,1.91 × 10-2,and 1.96 × 10-2,respectively,meaning that no significant difference was observed in the mutation frequency between the empty vector cells and cells overexpressing MUTYH mutants.CONCLUSION:The suppressive activities of p.R154H,p.M255V,p.L360P,and p.P377L MUTYH variants against mutations caused by 8OHG are thought to be severely impaired in human cells.

Preparation and characterization of CuO-CoO-MnO/SiO_2 nanocomposite aerogels as catalyst carriers

CuO-CoO-MnO/SiO2 nanocomposite aerogels were prepared by using tetraethyl orthosilicate(TEOS) as Si source,and aqueous solution of Cu,Co and Mn acetates as the precursors via sol-gel process and ethanol supercritical drying technique.The gelatination mechanism was investigated by nuclear magnetic resonance(NMR) and X-ray photoelectron spectroscopy(XPS).The microstructure and composition of the CuO-CoO-MnO/SiO2 nanocomposite aerogels were characterized by field emission scanning electron microscopy(FE-SEM),transmission electron microscopy(TEM),electron dispersive spectroscopy(EDS) and XPS.The specific surface area,pore size and pore size distribution of the nanocomposite aerogels were determined by the Brunauer–Emmett–Teller(BET) method.The products were analyzed by gas chromatography(GC).The results show that the CuO-CoO-MnO/SiO2 nanocomposite aerogels are porous,with a particle size distribution of 10–150 nm,a pore size distribution of 2–16 nm,an average pore size of 7.68 nm,and a specific surface area of 664.4-695.8 m2/g.The molar fraction of transition metals in the nanocomposite aerogels is 0.71%-13.77%.This kind of structure is favorable not only to increase the loading of catalysts,but also to make full use of the effect of transition metal oxides as cocatalysts;CuO-CoO-MnO/SiO2 nanocomposite aerogels can be used as a novel catalyst carrier in the safer and environment-friendly synthesis of diphenyl carbonate and other fields of catalysis.

Surface photovoltage phase spectroscopy study of the photo-induced charge carrier properties of TiO_(2) nanotube arrays

By using the surface photovoltage (SPV) technique based on a lock-in amplifier, surface states located 3.1 eV below the conduction band of TiO_(2) have been detected in TiO_(2) nanotube arrays prepared by anodization of titanium foil in fluoride-based ethylene glycol solution. The photo-induced charge transportation behavior of TiO_(2) nanotube arrays was also studied by quali- tatively analyzing their SPV phase spectra measured under different external bias. When a negative bias was applied, carriers excited from surface states have the same transportation properties as those excited from the valence band; in contrast, when a positive bias was applied, these two kinds of photo-excited carriers exhibit different transportation behavior..

5 nm NiCoP nanoparticles coupled with g-C3N4 as high-performance photocatalyst for hydrogen evolution

Graphitic carbon nitride(g-C3N4) coupled with NiCoP nanoparticles with sizes around 5 nm have been fabricated via a controllable alcohothermal process. NiCoP is an excellent electron conductor and cocatalyst in photocatalytic reactions. The coupling between tiny NiCoP nanoparticles and g-C3N4 through in-situ fabrication strategy could be a promising way to eliminate the light screening effect, hinder the recombination of photo-induced charge carriers, and improve the charge transfer. The NiCoP/g-C3N4 nanohybrids exhibit an excellent photocatalytic activity in the hydrogen generation, with a significantly improved performance compared with original g-C3N4, CoP/g-C3N4 and Ni2P/g-C3N4, respectively. This study paves a new way to design transition metal phosphides-based photocatalysts for hydrogen production.