大黄素联合5AzA-cdR对胰腺癌抑癌基因p16、RASSF1A去甲基化作用研究

目的研究大黄素是否可增强5AzA-cdR对胰腺癌Panc1细胞抑癌基因p16、RASSF1A的去甲基化作用。方法采用细胞增殖实验检测不同浓度大黄素对Panc1细胞的生长抑制情况，焦磷酸盐测序PCR（BSP）分别检测大黄素、5AzA-cdR及大黄素联合5AzA-cdR对Panc1细胞抑癌基因p16、RASSF1A甲基化状态的影响，并用荧光定量PCR（FQ-PCR）和Westernblot分别检测p16、RASSF1A及甲基转移酶DNMT1、DNMT3a在mRNA和蛋白水平的表达情况。结果大黄素以时间和浓度梯度依赖性抑制Panc1细胞生长。BSP结果显示大黄素具有微弱的去甲基化作用，5AzA-cdR具有一定程度的去甲基化作用，当两者联用时，去甲基化作用更加显著；FQ-PCR和Westernblot结果显示大黄素与5AzA-cdR联用时，p16、RASSF1A的表达水平均较空白对照明显增高（均P＜0.05），DNMT1、DNMT3a的表达水平均较空白对照明显降低（均P＜0.05）。结论大黄素与5AzA-cdR联用可通过降低DNMT1和DNMT3a的表达水平来增强5AzA-cdR对胰腺癌抑癌基因p16、RASSF1A的去甲基化作用。     

新型丹皮酚衍生物的合成

根据拼合原理,将丹皮酚和非甾体抗炎药通过连接臂[(CH2)n或NCH2CH2]偶联合成了8个新型的丹皮酚衍生物,其结构经1H NMR和HR-MS表征。     

Structure Analysis of Needle-like Copper Tantalum Trisulfide Crystals by XPS and Raman Spectroscopy

High-quality needle-like CuTaS3 single crystals have been synthesized through a chemical vapor transport(CVT)process.Crystallographic data show the special double chains of edge-sharing TaS6 octahedra....     

Re（CO）3（L）系列配合物的成键和结构

借助于G03W程序包,对系列氨基羧酸分子的羰基铼配合物进行了结构优化,并对其中的相关能量、键长、键角、布局数等进行了研究.计算结果表明:各配合物相对于羰基铼中间体均具有一定的稳定性;配体分子结构中含有杂环或者较多数目杂原子时,有形成相对更稳定配合物的趋势;配体分子结构中应含有适宜的间隔体,否则需经较大的结构扭转或局部原子的拥挤方可形成相应配合物.     

Topotactic Conversion of Alkali-Treated Intergrown Germanosilicate CIT-13 into Single-Crystalline ECNU-21 Zeolite as Shape-Selective Catalyst for Ethylene Oxide Hydration

The conversion of the alkali-treated intergrowth germanosilicate CIT-13 into the single-crystalline high-silica ECNU-21 (named after East China Normal University) zeolite, with a novel topology and a highly crystalline zeolite framework, has been realized through a creative top-down strategy involving a mild alkaline-induced multistep process consisting of structural degradation and reconstruction. Instead of acid treatment, hydrolysis in aqueous ammonia solution not only readily cleaved the chemically weak Ge(Si)−O−Ge bonds located within the interlayer double four ring (D4R) units of CIT-13, but also cleaved the metastable Si−O−Si bonds therein. This led to extensive removal of the D4R units, and also generated silanol groups on adjacent silica-rich layers, which then condensed to form a novel daughter structure upon calcination. Individual oxygen bridges in the reassembled ECNU-21 replaced the germanium-rich D4R units in CIT-13, thereby eliminating the original intergrowth phenomenon along the b axis. With an ordered crystalline structure of 10-ring (R) channels as well as suitable germanium-related Lewis acid sites, ECNU-21 serves as a stable solid Lewis acid catalyst for the shape-selective hydration of ethylene oxide (EO) to ethylene glycol (EG) at greatly reduced H₂O/EO ratios and reaction temperature in comparison with the noncatalytic industrial process.     

Microwave‐Enhanced Ferrier Reaction: A Facile Synthesis of 2,3‐Unsaturated‐O‐Glycosides Under Solvent‐Free Conditions

A variety of 2,3‐unsaturated‐O‐glycosides have been prepared by the Ferrier rearrangement of acetyl protected glycals under microwave irradiation using silica gel as an acid catalyst. Environmental friendliness, high yields, and short reaction times are the key features of this method. Furthermore, the method was applicable not only to the Ferrier reaction of 3,4,6‐tri‐O‐acetyl glucal and 3,4,6‐tri‐O‐acetyl galactal but also to the Ferrier reaction of 3,4‐di‐O‐acetyl arabinal.     

多项式环中单项式理想的分解

利用单项式理想生成元的性质,给出了一类特殊单项式理想(生成元是变量的纯幂)的幂的分解表达式,这不仅拓宽了我们对多项式理论内容的认识,而且这样的分解表达式提供了这类单项式理想正则度(Castelnuovo-Mumford regularity)计算的方法.     

对数平均和双参数广义Muirhead平均之间的比较

本文讨论了两个不同正实数x和y的对数平均L(x,y)=(x-y)/(logx-logy)与双参数广义Muirhead平均M(a,b;x,y)=[(x~ay~b+x~by~a)/2]~(1/(a+b))之间的比较,得到了如下三个结论:(11)若(a,b)∈D_1∪E_1∪L_0,则M(a,b;x,y)L(x,y);(2)若(a,b)∈D_2∪E_2,则M(a,b;x,y)L(x,y);(3)若(a,b)∈D_3∪E_3,则存在x_1,y_1,x_2,y_2,使得M(a,b;x_1;y_1)L(x_1,y_1)和M(a,b;x_2,y_2)L(x_2,y_2).其中D_1={(a,b)∈R~2:a+b≠0,ba,ω_1(a,b)≤0,ω_2(a,b)≤0},E_1={(a,b)∈R~2:a+b≠0,ba,ω_1(a,b)≤0,ω_2(a,b)≤0},D_2={(a,b)∈R~2:ab≤0,ba,ω_1(a,b)≥0},E_2={(a,b)∈R~2:ab≤0,ba,ω_1(a,b)≥0},D_3={(a,b)∈R~2:ba0,ω_1(a,b)0)∪{(a,b)∈R~2:ba0,ω_1(a,b)=0,ω_2(a,b)0}∪{(a,b)∈R~2:ba,ab≤0,ω_1(a,b)0,ω_2(a,b)0},E_3={(a,b)∈R~2:ab0,ω_1(a,b)0}∪{(a,b)∈R~2:ab0,ω_1(a,b)=0,ω_2(a,b)0}∪{(a,b)∈R~2:ab,ab≤0,ω_1(a,b)0,ω_2(a,b)0},L_0={(a,b)∈R~2:a=b≠0},ω_1(a,b)=(a+b)[3(a-b)~2-(a+b)],ω_2(a,b)=(a+b)[2(a-b)~2+1]-3(a~2+b~2).     

钯纳米粒子的形貌可控合成与催化性能

借助于一种全新的表面活性剂N,N-dimethyloctadecylammonium bromide acetate sodium（OTAB-Na）,成功实现了对小尺寸钯纳米粒子微结构的控制。通过对合成条件的微扰,高度均匀且分散性良好的枝化结构和凹面体结构的钯纳米粒子被成功地制备。催化测试（利用氨硼烷作为氢化试剂来还原4-硝基苯酚为4-胺基苯酚）发现,钯纳米粒子的催化活性与其微观纳米结构相关,其中枝化结构的钯纳米粒子表现出了更为突出的催化性能。     

电喷雾电离源测定印刷线路板阵列离子阱的分析性能

电喷雾电离源(ESI)测定了印刷线路板材料制成的四通道PCB矩形离子阱中一个通道的的分析性能。结果表明,质谱峰检测到的离子信号的种类和强度明显受到离子动能的影响。当离子动能低于18 eV,则得到的质谱峰主要为精氨酸Arg离子(m/z 175.2),增加其离子动能则Arg离子(m/z 175.2)易碎裂,发生脱胍基、脱水等反应。在正弦波的射频模式下测定了离子质量隔离和离子质量选择激发,以SWIFT缺口频率为50～60 kHz,75～85 kHz和130～145 kHz分别隔离了m/z 175.2,117.3和71.8的离子;用频率为55、80和135 kHz的正弦波(振幅为1.0 V)选择激发弹出了m/z 175.2,117.3和71.8的离子。在氦气气氛下,频率为102 kHz正弦波可以使得Arg离子(m/z 175.2)发生碎裂,得到m/z 157.2,130.3和117.3碎片离子。电流积分法的测定结果表明,在256 kHz共振激发时离子测定效率为46.3%,在边界弹出时,离子测定效率约为9.7%。