Micellar Solubilization and In Vitro Release of Silymarin in the self-Aggregates of an Amphiphilic Derivative of Chitosan

Summary: The amphiphilic derivatives of chitosan, (2-hydroxyl-3-butoxyl)-propylcarboxymethyl-chitosan (HBP-CMCHS), can form micelles with the inner core of hydrophobic segments and the outer shell of hydrophilic segments. The typical poor water-soluble drug silymarin was solubilized in the HBP-CMCHS micellar by physical entrapped method. Results showed that the solubilizing capacity was enhanced by increasing the concentration of HBP-CMCHS with the same dosage of silymarin. Silymarin-loaded micellar system of HBP-CMCHS was characterized by TEM and DLS. TEM photograph revealed that the micelles were spherical and silymarin was solubilized in the cores of the spherical polymeric micelles. DLS showed that after solubilization the size of the micelles became bigger. In vitro tests showed that silymarin was slowly released from micellar solution and the release lasted up to 40 h by means of the dialysis method.     

Synthesis of High Quality CuInSe2 Films with Oxygen Precursor by Non-vacuum Process

The CuInSe₂ absorber was synthesized by non-vacuum process with a simple and low-cost method, which fabricated absorber layer of thin-film solar cell. The extra amount of Se was added into the ink to help reduction of the oxide and solid Se fountain was used to provide Se atmosphere during the selenization progress. The influence of same factors was investigated, such as the time of reduction in H₂, the time of selenization and the Se vapor pressure. The selenizaion, processed at 550 °C for 60 min with the Se vapor pressure at 1.90 kPa, resulted in high quality CuInSe₂ layer with very good chemical composition.     

基于核酸切割酶与脱氧核酶的荧光循环放大系统检测铅(Ⅱ)

利用核酸切割酶(Nicking endonuclease)识别特定DNA双链并切割其中某条单链的性质,构建了基于8-17E脱氧核酶(8-17E DNAzyme)的pb2+荧光循环放大检测方法.pb2+可激活8-17E脱氧核酶水解RNA底物,产生并释放出的单链与分子信标探针( Molecular beacon,MB)杂交,导致其茎环结构被破坏,荧光信号恢复;同时形成含有核酸切割酶Nt.BbvCI识别位点的双链区域.在核酸切割酶Nt.BbvCI的作用下,分子信标探针被切割释放,游离出来的单链可与其它分子信标重新杂交,从而触发下一轮酶切,引起荧光检测信号的循环放大.本方法避免了8-17E脱氧核酶与底物链的修饰,最低可以检测出水溶液中1.0×10-10 mol/L Pb2+,并在2倍浓度的Zn2+,以及5倍浓度的其它干扰金属离子存在的情况下对pb2+显示出良好的选择性.本方法对环境水样中pb2+的标准加样回收率为96.1％～108.0％.     

单分散交联聚苯乙烯微球HPLC固定相的合成

用分散聚合物合成了单分散聚苯乙烯微球种子，然后用种子聚合法合成了交联的聚苯乙烯向球，其粒径范围可控制在２μｍ～４μｍ，考察了反应条件对微球粒径和粒径分布的影响，确定了最佳合成条件，初步考察了交联微球的ＨＰＬＣ性能。     

火花源质谱法定量分析高纯氧化钬和氧化镥中痕量元素

本文采用相对灵敏度因子，研究了９９．９９９％－９９．９９９９％的Ｈｏ２Ｏ３和Ｌｕ２Ｏ３中４０余种杂质元素的火花源定量分析方法，讨论了谱线干扰。做了加入回收及生理性实验，大多数元素的相对标准偏差在３０％以内，检测下限为０．００ｘμｇ／ｇ。     

相对论赝势的从头计算法研究铀酰离子电子结构

用相对论赝势的从头算法研究了铀酰离子的几何构型和电子结构.得到了与实验数据较一致的键长、键角和IR振动频率.铀氧间以U5f与O2p相互作用为主,U6d与O2p间的键合较小;同时,U6p、U7s、U6d和Usd杂化轨道与O2s间也有强的相互作用.不同自旋多重度时对铀酰离子总能量计算结果表明,UO22+的基态为1∑g+的可能性更大.     

Bonded excimer in stacked adenines:Semiclassical simulations

The nonradiative decay of a π-stacked pair of adenine molecules,one of which was excited by an ultrafast laser pulse,is studied by semiclassical dynamics simulations.This simulation investigation is focused on the effect of the formation of bonded excimer in stacked adenines on the mechanism of ultrafast decay.The simulation finds that the formation of the bonded excimer significantly lowers the energy gap between the LUMO and HOMO and consequently facilitates the deactivation of the electronically excited molecule.On the other hand,the formation of the chemical bond between two stacked adenines restricts the deformation vibration of the pyrimidine of the excited molecule due to the steric effect.This slows down the formation of the coupling between the HOMO and LUMO energy levels and therefore delays the deactivation process of the excited adenine molecule to the electronic ground state.     

1-羟基异喹啉及羟基Fasudil的合成

首先以异喹啉为原料,经氧化生成氮氧化物后与苯甲酰氯和水作用,得到1-羟基异喹啉,收率为73.3%.以Fasudil为原料,经氨基保护、氧化,在相转移催化剂的存在下,于二氯甲烷和水的两相体系中与苯甲酰氯和水作用,合成羟基Fasudil,HPLC纯度大于99%,总收率为46.8%,从而建立了一条条件温和、操作简便的羟基Fasudil的合成工艺路线.     

A preliminary investigation on the determination of lanthanoids, thorium and uranium in brine and deposit of a salt lake in China

A brine sample and two deposit samples of a salt lake in China were analyzed for their contents of lanthanoids (Ln's), thorium and uranium by neutron activation analysis. Five Ln's were determined at sub ppb levels. Th and U contents were at about the same levels as those of Ln's. The lanthanoid abundance patterns (Ln pattern) of the three samples are similar to each other, each having a negative slope in the light Ln region. There seems no substantial difference in distribution between the solution (brine) and solid (deposit) phases among Ln's.     

A Surface Rheological Study of Polyoxyethylene Alkyl Ether Carboxylic Salts and the Stability of Corresponding Foam

The dynamic dilational viscoelastic properties of polyoxyethylene alkyl ether carboxylic salts at the air-water interface were investigated by drop shape analysis method and their foam stability were measured by Bikerman Method. The influences of time, dilational frequency, and bulk concentration on surface dilational modulus and phase angle were expounded. The results show that the surfactant with the longest straight-chain shows the highest dilational modulus, which in agreement with the best foam stability. However, the foam stability of branched-alkyl chain surfactant cannot be explained in terms of film elasticity alone.