Cu(ii)/SPDO complex catalyzed asymmetric Baeyer–Villiger oxidation of 2-arylcyclobutanones and its application for the total synthesis of eupomatilones 5 and 6

A novel classical kinetic resolution of 2-aryl-substituted or 2,3-disubstituted cyclobutanones of Baeyer–Villiger oxidation catalyzed by a Cu(ii)/SPDO complex is reported for the first time, producing normal lactones in excellent enantioselectivities (up to 96% ee) and regioselectivities (up to >20/1), along with unreacted ketones in excellent enantioselectivities (up to 99% ee). The current transformation features a wide substrate scope. Moreover, catalytic asymmetric total syntheses of natural eupomatilones 5 and 6 are achieved in nine steps from commercially available 3-methylcyclobutan-1-one.

A novel classical kinetic resolution of Baeyer–Villiger oxidation catalyzed by a Cu(ii)/SPDO complex with excellent enantioselectivity, regioselectivity and wide substrate scope is reported for the first time and explore the synthetic application.     

分形维数的多尺度形态估计与目标提取

本文研究了Minkowrki－Bouligand维数估计的数学形态学方法实现，给出了一种基于多尺度灰度形态运算的图像维数估计算法。将分形特征用于目标的检测，提出了一种具有较好稳健性的基于多分辨率分形特征的目标提取方法。     

Spherical distribution structure of the semiconductor laser diode stack for pumping

A semiconductor laser diode stack is used for pumping and 8 semiconductor laser diode arrays of the stack are put on a sphere,and the output of every bar is specially off-axis compressed to realize high coupling efficiency.The output beam of this semiconductor laser diode stack is shaped by a hollow duct to the laser active medium.The efficiency of the hollow light pipe,which is used for semiconductor laser diode stack coupling,is analyzed by geometric optics and ray tracing.Geometric optics analysis diagnoses the reasons for coupling loss and guides the design of the structure.Ray tracing analyzes the relation between the structural parameters and the output characteristics of this pumping system,and guides parameter optimization.Simulation and analysis results show that putting the semiconductor laser diode arrays on a spherical surface can increase coupling efficiency, reduce the optimum duct length and improve the output energy field distribution.     

基于精确模型的毫米波单片集成电路设计

介绍了毫米波单片集成电路设计中的两个关键技术，有源器件（如ＰＨＥＭＴ）等效电路模型的建立和无源元件（如微带Ｔ形结、十字结、转角等）精确电磁场模型的建立，同时介绍了毫米波单片放大器的ＣＡＤ设计过程。     

纳秒脉冲治疗裸鼠皮下移植瘤抗癌机制研究

本研究探讨了纳秒级陡脉冲(nsPEF)对人恶性黑色素瘤A375细胞裸鼠皮下移植瘤模型可能的抗癌机制.通过用游标卡尺测量裸鼠皮下瘤大小,估算抑瘤率.用琼脂糖凝胶电泳、TUNEL法检测肿瘤细胞在纳秒脉冲电场下的细胞凋亡情况,并用HE染色观察细胞形态变化.通过免疫组化法检测瘤体内微血管密度MVD、微血管形态、血管生长因子VEGF和增殖细胞核抗原PCNA的表达.结果发现nsPEF治疗后4d肿瘤生长抑制率达42.6％,琼脂糖凝胶电泳显示治疗后2h组出现阶梯状分布,治疗后4d组阶梯状分布较之明显,对照组未见阶梯状分布;TUNEL法显示治疗组凋亡率均高于对照组,治疗后4d组凋亡率明显高于2h组(p＜0.01).脉冲处理后见肿瘤区即刻变为灰白色;HE染色发现治疗后2h组肿瘤见少许坏死区域、4d组肿瘤坏死区域增多;免疫组化检测发现治疗后4d组微血管腔闭塞状态、MVD、VEGF及PCNA表达较对照组及治疗后2h组明显增多(P＜0.01),而对照组与治疗后2h组比较差异无统计学意义(P＞0.05).结果表明纳秒级陡脉冲可能通过诱导细胞大量凋亡,短时间内降低肿瘤血流量,降低细胞增殖能力并降低肿瘤血管形成和重塑以防止肿瘤再生等方面发挥其抗癌效应.     

Structural and Functional Analysis of the Pyridoxal Phosphate Homeostasis Protein YggS from Fusobacterium nucleatum

Pyridoxal 5′-phosphate (PLP) is the active form of vitamin B6, but it is highly reactive and poisonous in its free form. YggS is a PLP-binding protein found in bacteria and humans that mediates PLP homeostasis by delivering PLP to target enzymes or by performing a protective function. Several biochemical and structural studies of YggS have been reported, but the mechanism by which YggS recognizes PLP has not been fully elucidated. Here, we report a functional and structural analysis of YggS from Fusobacterium nucleatum (FnYggS). The PLP molecule could bind to native FnYggS, but no PLP binding was observed for selenomethionine (SeMet)-derivatized FnYggS. The crystal structure of FnYggS showed a type III TIM barrel fold, exhibiting structural homology with several other PLP-dependent enzymes. Although FnYggS exhibited low (<35%) amino acid sequence similarity with previously studied YggS proteins, its overall structure and PLP-binding site were highly conserved. In the PLP-binding site of FnYggS, the sulfate ion was coordinated by the conserved residues Ser201, Gly218, and Thr219, which were positioned to provide the binding moiety for the phosphate group of PLP. The mutagenesis study showed that the conserved Ser201 residue in FnYggS was the key residue for PLP binding. These results will expand the knowledge of the molecular properties and function of the YggS family.     

毛细管区带电泳法测定霍香正气胶囊中和厚朴酚的含量

目的:建立霍香正气胶囊中和厚朴酚含量测定的毛细管区带电泳(CZE)法.方法:采用甲醇溶解样品超声制备供试液;运行缓冲液为40mmol/L硼砂溶液,检测波长254nm.结果:和厚朴酚线性范围0.013-0.20mg/mL,r=0.9917(n=5),厚霍香正气胶囊中和厚朴酚的含量为0.1479mg/粒.结论:此方法快速简便,可用于评价霍香正气胶囊的质量.     

微波烧结Al_2O_3陶瓷的研究

简要介绍了微波烧结的特点,对 Ａｌ２ Ｏ３ 陶瓷的微波烧结过程进行了介绍和分析,并同常规烧结进行了对比实验,在此基础上得出了一些结论,为陶瓷微波烧结提供了实验依据