SNAP-tag蛋白标签技术与荧光分析法在蛋白原位分析中的联合应用

为将生物体内微观的蛋白行为可视化并以宏观信号呈现出来对蛋白进行实时、动态分析，借助SNAP-tag蛋白标签技术与有机小分子荧光染料，构建了一系列用于活细胞内实时监测目标蛋白的免洗荧光探针。标签蛋白SNAP-tag能够特异性识别探针中的苄基鸟嘌呤，从而使目标蛋白共价连接上荧光团（萘酰亚胺），携带上荧光信使。此外，由于萘酰亚胺从水环境中被牵引至SNAP-tag蛋白的疏水空腔，其荧光信号呈现出2~13倍的增强。通过SNAP-tag标签蛋白与目标蛋白的融合，该荧光探针实现了对活细胞内线粒体蛋白CoX8A及核内蛋白H2B特异性识别，在免洗条件下完成了对目标蛋白的实时追踪及原位分析。     

Ubiquitous strategy for probing ATR surface-enhanced infrared absorption at platinum group metal-electrolyte interfaces

A versatile two-step wet process to fabricate Pt, Pd, Rh, and Ru nanoparticle films (simplified as nanofilms hereafter) for in situ attenuated total reflection Fourier transform infrared (ATR-FTIR) study of electrochemical interfaces is presented, which incorporates an initial chemical deposition of a gold nanofilm on the basal plane of a silicon prism with the subsequent electrodepostion of desired platinum group metal overlayers. Galvanostatic electrodeposition of Pt, Rh, and Pd from phosphate or perchloric acid electrolytes, or potentiostatic electrodeposition of Ru from a sulfuric acid electrolyte, yields sufficiently "pinhole-free" overlayers as evidenced by electrochemical and spectroscopic characterizations. The Pt group metal nanofilms thus obtained exhibit strongly enhanced IR absorption. In contrast to the corresponding metal films electrochemically deposited directly on glassy carbon and bulk metal electrodes, the observed enhanced absorption for the probe molecule CO exhibits normal unipolar band shapes. Scanning tunneling microscopic (STM) images reveal that fine nanoparticles of Pt group metals are deposited around wavy and stepped bunches of Au nanoparticles of relatively large sizes. This ubiquitous strategy is expected to open a wide avenue for extending ATR surface-enhanced IR absorption spectroscopy to explore molecular adsorption and reactions on technologically important transition metals, as exemplified by successful real-time spectroscopic and electrochemical monitoring of the oxidation of CO at Pd and that of methanol at Pt nanofilm electrodes. The spectral features of free water molecules coadsorbed with CO on Pt, Pd, Rh, and Ru are also discussed.     

CrOx/ SBA-15介孔催化剂上丙烷在二氧化碳气氛中脱氢反应的研究

The structure and catalytic properties based on Chromium Oxide supported on mesoporous SBA-15 for oxidative dehydrogenation of propane by CO₂ have been studied by using X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance spectra (UV-Vis DRS), electron spin resonance (ESR), X-ray photoelectron spectroscopy (XPS) and propane pulsing experiments in the absence of gas-phase O₂. It has been shown that propane conversion and propene yield increase with Cr loadings. The propane conversion and propene yield on CrO_x(Cr: 10wt%)/SBA-15 catalyst for oxidative dehydrogenation of propane by CO₂ at 550 ℃ reach 24.8% and 21.8%, respectively .The results of ESR, UV-Vis DRS and propane pulsing experiments indicate that Cr^Ⅲ in the CrO_x/ SBA-15 catalyst is the main active species in oxidative dehydrogenation of propane by CO₂ and Cr^Ⅵ, Cr^Ⅴ is inactive in dehydrogenation.     

1-烷（苯）氧基-3-（3，4-亚甲基二氧）苯基-2-丙醇的合成与生物活性研究

黄樟素氧化物与烷氧基钠和苯氧基钠反应，区域选择性地开环加成，生成1-烷 （苯）氧基-3-（3，4-亚甲基二氧）苯基-2-丙醇。该系列化合物具有诱导细胞凋 亡与分化的生物活性。     

Synthesis and Electrospray Ionization Mass Spectra of N-（1,3, 2-Dioxaphosphorinan-2-ylmethyl）thiophosphoramidates

N-（1,3,2-Dioxaphosphorinan-2-ylmethyl）thiophosphoramidates were synthesized and determined by NMR spectra and positive ion electrospray ionization mass spectrometry （ESI-MS） in conjunction with tandem mass spectrometry （MS/MS）. The fragmentation pathways were investigated. The results show that these characteristic ions in ESI mass spectra are useful in the structural determination of N-（1,3,2-dioxaphosphorinan-2-ylmethyl）- thiophosphoramidates.     

Laser-assisted electron capture by a fast proton from a hydrogen atom

The first Born approximation is used to study the laser-assisted electron capture by a fast proton from a hydrogen atom. The laser modification on differential cross section peaks sharply in the forward direction. With the impact energy increasing, the change in integral cross section becomes notable. The more intense the laser, the greater the cross section is; the lower the frequency, the greater the cross section.     

SrTi0.9M0.1O3-δ钙钛矿型氧化物催化剂甲烷氧化偶联反应性能的研究

The structure and catalytic properties of SrTi_0.9M_0.1O_3-δ (M=Mg，Al， Zr) perovskite-type catalysts for ox-idative coupling of methane (OCM) have been studied by using X-ray diffraction (XRD)，X-ray photoelectron spectroscopy (XPS) and temperature-programmed desorption of oxygen(O₂-TPD) methods. It has been shown that doping the cations of lower valence (e.g. Mg²⁺， Al³⁺) to the B site of SrTi_0.9M_0.1O_3-δ perovskite-type catalysts results in the higher content of adsorbed oxygen species on the surface of catalysts and thus higher C₂-selectivity for OCM reaction. It is suggested that the oxygen vacancies of SrTi_0.9M_0.1O_3-δ (M=Mg， Al， Zr) perovskite-type catalysts are the sites responsible for oxygen activation， and the adsorbed oxygen species on the surface of SrTi_0.9M_0.1O_3-δ catalysts are the main active species for OCM reaction.     

Enantioselective Addition of Phenylacetylene to Aldehydes Catalyzed by Polymer-Supported Sulfonamide

Enantioselective formation of C-C bonds is an area of intense research. Among them, the asymmetric addition of alkynyl reagents to aldehydes is very useful for the synthesis of chiral secondary propargyl alcohols.[1] Recently, many significant homogeneous chiral ligands have been disclosed,[2,3] but very few efficient heterogeneous catalysts have been reported. Herein, we report our research results in the asymmetric addition of phenylacetylene to aldehydes catalyzed by polymer-supported chiral sulfonamide.     

选择性远程DEPT NMR技术用于萜类生物碱的结构测定

从中草药勒党根茎中分离出二个化合物, 其一为已知的萜类生物碱culamtraramine, 其二为它的差向立体异构体, 为新化合物, 定名为isoculantraramine。用选择性远程核磁共振技术测定了它们的结构。     

Tunable surface-enhanced infrared absorption on au nanofilms on si fabricated by self-assembly and growth of colloidal particles

Au colloids were used to fabricate nanoscale-tunable Au nanofilms on silicon for surface-enhanced IR absorption bases in both ambient and electrochemical environments. This wet process incorporates the self-assembly of colloidal Au monolayer using 3-aminopropyl trimethoxysilane as the organic coupler with subsequent chemical plating in an Au(III)/hydroxylamine solution. FTIR spectroscopy in transmission mode of the probe species SCN- was used to evaluate the apparent surface enhancement in IR absorption of 2D Au colloid arrays and chemically plated Au particles. The nanostructure of Au films was examined by atomic force microscopy. The IR and AFM results show that the apparent surface enhancement factor (1-2 orders of magnitude) increases with increasing sizes and/or contact, and the severe aggregation of Au nanoparticles may cause the bipolar band shape. Cyclic voltammetry on the Au nanofilm obtained by the above nucleation and growth strategy exhibits a feasible electrochemical stability and behavior. In situ ATR-FTIR measurement of p-nitrobenzoic acid adsorption demonstrates that the as-grown Au film yields rather promising surface enhancement as well.