苯乙烯/丙烯酸正丁酯乳液聚合反应过程中残余单体含量的实时监测

采用近红外光谱分析技术在线测量苯乙烯(St)/丙烯酸正丁酯(BA)乳液聚合体系中残余单体的含量. 共设计9个半连续方式的St/BA乳液共聚反应, 在反应过程中实时取样测量其残余单体含量, 并记录取样时刻对应的聚合体系的近红外光谱. 采用多元散射校正法(MSC)处理光谱, 有效地克服了乳胶粒子散射效应对近红外光谱分析的影响. 采用主成分分析法(PCA)对乳液体系的近红外光谱数据进行了解析. 选取6个聚合反应对应不同反应时间的72个样品, 用于建立校正模型, 另外3个聚合反应共取36个样品用于校正模型的验证, 并在反应设计上体现了乳化剂用量的变化, 从而使校正模型对乳化剂用量的变化具有一定的适应性. 研究结果表明, 所得模型对残余单体St和BA含量的预测结果标准差(SEP)分别为0.08026和0.05305.     

用生物质谱方法研究抗肿瘤双β-咔啉与DNA及核苷酸的非共价结合

利用电喷雾傅里叶变换离子回旋共振质谱研究一系列双β-咔啉化合物与DNA的非共价结合. 发现化合物1—5与5种不同序列的12-mer双链DNA均有明显的非共价结合, 并且有两个β-咔啉环之间连接碳链的长度对此类化合物与双链DNA的非共价结合活性有明显影响. 同时对此类化合物对于DNA非共价结合的序列选择性进行了讨论. 另外还利用电喷雾离子阱质谱研究了双β-咔啉化合物2和4与4种单核苷酸的非共价结合.     

2-(2-甲基烯丙基)-3-(3-甲基-1,2-丁二烯基)环己-2-烯酮重排生成八元环化合物反应机理的理论研究

采用密度泛函理论B3LYP/6-31G(d,p)方法研究了2-(2-甲基丙烯基)-3-(3-甲基-1,2-丁二烯基)环己-2-烯酮重排生成八元环化合物在气相中的反应机理. 考虑了两条可能的反应途径: 途径1包含5个过程, 途径2包含两个过程. 从能量上看, 两条途径的决定速度步均是[1,5]氢迁移. 采用自洽反应场极化连续模型(PCM模型)和极化导体模型(CPCM模型)研究了反应体系在甲苯溶液中的溶剂效应. 结果表明, 气相和溶液中途径2均是较优途径, 并且甲苯对该反应的溶剂化效应不明显. 理论研究结果与实验观察结果一致, 并很好地解释了有关实验现象.     

2-甲基-1-(4-芳基噻唑-2-基)-苯并咪唑-6-甲酸乙酯的合成、表征及生物活性

以4-乙酰氨基苯甲酸乙酯为原料设计合成了14 种2-甲基-1-(4-芳基噻唑-2-基)-苯并咪唑-6-甲酸乙酯新化合物. 化合物结构经质谱、1H NMR、红外光谱和元素分析等确证, 并用单晶X射线衍射仪测定了化合物5a的晶体结构. 生物活性实验结果表明, 化合物5c(500 mg/L)对小麦白粉病菌抑制率达到95%; 化合物5e对辣椒疫霉病菌(25 mg/L)的抑制率为61.9%, 对油菜菌核病菌(500 mg/L) 抑制率高达97.2%; 化合物5k(25 mg/L) 对小麦赤霉病菌抑制率为55.1%.     

n(Mg)/n(Al)=3的水滑石层板结构及层间距的阴离子调控

利用密度泛函理论(DFT)的B3PW91方法在Lanl2dz水平上研究了镁铝摩尔比为3的水滑石层板分子簇模型[Mg30Al7(OH)72]9+的几何构型, 优化得到的结构参数和采用Reflex模块模拟得到的XRD图谱分别与实验观测结果相符, 由此确定了水滑石层板沿第三维方向的有序堆积, 该结构符合空间群R3m(166), 其晶胞参数a=1.2552 nm, c=2.3400 nm. 进一步构造了具有R3m空间群对称性的Mg-Al-CO32--LDH晶体结构模型, 选取其中的簇模型, 经优化得到了一种稳定构型, 脱除结晶水的水滑石层间距为0.7260 nm, 键参数的变化表明碳酸根离子与层板间存在较强的超分子作用.     

Synthesis and Herbicidal Activity of Novel Sulfonylureas Containing Thiadiazol Moiety

Thirteen novel sulfonylureas containing thiadiazole moiety were synthesized in a two-step reaction. Their structures were determined using IR, ^1H NMR, HRFTMS, and elemental analysis. Herbicidal activities of these compounds were determined in the green house bio-assay. The results show that four compounds among them exhibit some activity toward four tested herbs.     

Isolation of Trichoderma reesei pyrG Negative Mutant by UV Mutagenesis and Its Application in Transformation

Two uridine auxotrophic mutants of Trichoderma reesei were isolated by resistance to 5-fluoroorotic acid after UV mutagenesis. One mutant, called M23, was complemented with the Aspergillus niger pyrG gene carried by plasmid pAB4-1. A mutated pyrG gene of M23 was cloned and DNA sequencing analysis indicated that a cytosine was inserted into the 934―939 oligo dC position of the pyrG coding region, resulted in a frameshift mutation. Transformation efficiency was approximately 200―300 transformants per microgram of DNA with plasmid pAB4-1. Stable transformants were obtained by monosporic culture and showed to be prototroph after successive propagation. Vitreoscilla hemoglobin expression plasmid pUCVHb was cotransformed with plasmid pAB4-1 and attained a transformation efficiency of 71.8% or of 26.1% with pAN7-1. Southern blot analysis of the transformants demonstrated that plasmid pUCVHb was integrated into the chromosomal DNA. The experimental results demonstrated that the pyrG-based system was more efficient and timesaving than the conventional hygromycin B resistance-based transformation system.     

Effect of Ultrasonication on Optical Properties and Electronic States of Conjugated Polymer MEH-PPV

Poly[2-methoxy-5-（2＇-ethyl-hexyloxy）-1,4-phenylene vinylene]（MEH-PPV）solutions with different concen-trations were prepared in chloroform for different ultrasonication times.The ultraviolet absorption and photoluminescence（PL）spectra of the MEH-PPV solutions were measured,and the electronic states of the polymer chains under different experimental conditions were studied.The results showed that the effects of ultrasonication on the dilute and concentrated solutions were different.After ultrasonication,the intensity of the absorption peak at 280 nm significantly decreased,relative to the absorption peak at 500 nm for both dilute and concentrated solutions,indicating that the proportion of the two excited states in the polymer chains had changed.For dilute MEH-PPV solutions,the blue-shifted absorption（at about 500 nm）and PL spectra show that ultrasonication also led to polymer chain degradation and thus shortened the effective conjugation length.For concentrated solutions,however,the peak positions of the absorption spectra remained unchanged.In addition,the effects of the solution temperatures on the optical spectra for the MEH-PPV solutions were also discussed.     

Preparation and Characterization of Biodegradable Polylactide（PLA） Microspheres Encapsulating Ginsenoside Rg3

In this study, the process of a biodegradable polylactide（PLA） microsphere encapsulating ginsenoside Rg3 was first studied by the emulsion solvent evaporation method, for enhancing solubility and stability of ginsenoside Rg3. Alabum was also first used as a modifier in this method. The mean diameter of the prepared PLA microspheres containing Rg3 was 40 μm. Ginsenoside Rg3 released from the microspheres was studied by HPLC and detected by UV. It was found that the drug release curve fitted the Model Heller-Baker best.     

Isolation and Purification of Polysaccharides from Cordyceps minlitaris and Its Inhibition on the Proliferation of Rat Glomerular Mesangial Cells

The crude polysaccharide was obtained by means of the decolorization of porphyrized Cordyceps minlitaris stroma with organic solvent, extraction with hot water, precipitation in 80% ethanol, and protein removal with the Sevag method. After purification with Sephadex G-75, two of its components, CMP-1 and CMP-2, were obtained. Through the assay of gel chromatography and polarimetry, CMP-1 was identified as pure polysaccharide. The results demonstrated that CMP-1 had favorable oxidation resistance activity, which could scavenge not only oxygen-free radicals in the self-oxidation system of pyrogallic acid, but also the hydroxide-free radicals in the Fenton system. The study focused on the effects of low, medium, and high dosages of CMP-1 in rat blood serum on the proliferation of glomerular mesangial cells in vitro. Through MTT Colorimetric analysis, the activities were compared among the blank control group and the Niaoduqing positive control group CMP-1 and CMP-2. The results shows that CMP-1 was able to inhibit the proliferation of rat glomerular mesangial cells effectively. Therefore, CMP-1, one component of polysaccharides of Cordyceps minlitaris, was certainly a potential remedy for hyperplastic glomerular nephritis, whose antioxidant activity could slow down the process of chronic renal failure（CRF） to some extent.