Purification and partial characterization ofRhizomucor miehei lipase for ester synthesis

A commercialRhizomucor miehei lipase was purified by ammonium sulfate precipitation. Phenyl Sepharose 6 Fast Row hydrophobic interaction chromatography, and DEAE Sepharose Fast Flow anion-exchange chromatography. The recovery of lipase activity was 32% with a 42-fold purification. The molecular size of the purified enzyme was 31,600 Dalton and the pI 3.8. The enzyme was stable for at least 24 h within a pH range of 7.0-10.0, and 96.8% of the enzyme activity remained when kept at 30‡C for 24 h. Further, about 10–30% of the lipase activity was inhibited by K⁺, Li⁺, Ni⁺, Co²⁺, Zn²⁺, Mg²⁺, Sn²⁺, Cu²⁺, Ba²⁺, Ca²⁺, and Fe²⁺ ions and by SDS, but EDTA had no effect. Under the experimental conditions, the optimum temperature for the hydrolysis of olive oil was 50‡C (pH 8.0), and for the synthesis of 1-butyl oleate, 37‡C. It was concluded that hydrolytic activity of lipase alone is not a sufficient criterion for its synthetic potential. The optimal molar ratio of oleic acid and 1-butanol was 2:1 for 1-butyl oleate synthesis. The 1-butyl oleate yield was unaffected by purification of the enzyme after 12 h.     

三核簇合物(Et4N)2[(CO)4MoS2MoS2Mo(CO)4]和(Et4N)2[(CO)4MoS2WS2Mo(CO)4]的合成及晶体结构

合成了含Mo(0)的三核化合物(Et₄N)₂[(CO)₄Mo(μ-S)₂Mo(μ-S)₂Mo(CO)₄](Ⅰ)和(Et₄N)₂[(CO)₄Mo(μ-S)₂W(μ-S)₂Mo(CO)₄](Ⅱ),测定了(Ⅰ)的晶体结构.Ⅰ属单斜晶系,空间群P2相似文献   

Fe-Co-Ni合金纳米线有序阵列的模板合成与磁性

以二次阳极氧化的氧化铝膜为模板，用电化学沉积的方法成功地合成了Fe-Co-Ni三组份有序纳米线阵列.扫描电子显微镜（SEM）和透射电子显微镜(TEM)观察表明纳米线表面光滑、有序、高长径比；磁性测量表明,其矫顽力较同组份的膜材料有较大的提高.将样品在惰性气体氛围中不同温度下退火，随着退火温度增加，其纵向矫顽力有一个极值，而对应的横向矫顽力没有类似的变化，关于这一现象的机理,本文进行了初步的讨论. 图5参15     

Photocurrent generation in multilayer self-assembly films fabricated from water-soluble poly(phenylene vinylene)

A novel, water-soluble, cationic PPV derivative poly[(2,5-bis(3-bromotrimethylammoniopropoxy)-phenylene-1,4-divinylene)-alt-1,4-(2,5-bis(2-(2-hydroxyethoxy)ethoxy))phenylene vinylene] (BH-PPV) has been synthesized by a Heck coupling reaction. Multilayered assemblies of the BH-PPV and the sodium salt of hexa(sulfobutyl)fullerenes (C(60)-HS) were fabricated successfully by an alternate deposition technique. The multilayer structures were studied by UV/Vis spectroscopy, small angle X-ray diffraction, and atomic force microscopy. The photoinduced charge transfer property of the self-assembled multilayer film was also measured by a three-electrode cell technique. A steady and rapid cathodic 5.5 microA cm(-2) photocurrent response was measured as the irradiation of the multilayer film was switched on and off. Importantly, the response of on/off cycling is prompt and reproducible. A possible mechanism for the electron-transfer process is proposed.     

源内裂解液相色谱-质谱鉴别人参皂甙砒和拟人参皂甙F11

研究了利用源内碰撞诱导解离（in-source collision—induced dissociation）的高效液相色谱-大气压化学电离质谱（HPLC—APCI／MS）获取人参和西洋参的化学标志物——人参皂甙Rf和拟人参皂甙F11的特征结构信息及鉴别人参和西洋参的方法。在乙腈-水梯度洗脱反相液相色谱及源内碰撞诱导解离条件下，能获得人参皂甙Rf和拟人参皂甙F11的母核离子及去糖基离子的源内碰撞诱导解离谱，从其差别能清楚区分这对同分异构体。本方法对人参皂甙Rf和拟人参皂甙F11的检出限能达到10^-7g柱上样量，简单、快速，单次质谱实验就能鉴别人参和西洋参。     

含芳硫基的新三唑类化合物的合成及生物活性研究

许多三唑类化合物具有优良的杀菌和植物生长调节活性 ,如三唑酮、三唑醇、烯效唑、烯唑醇等 ,对常见真菌病害具有很好的防治效果 ,并具有增产、抗倒和生长调节作用 ,已成为重要的杀菌剂类型 [1] .为筛选新型高活性三唑类杀菌剂和探讨其活性与结构间的关系 ,我们利用生物等排体理论以常规三唑类杀菌剂三唑酮为先导物设计合成了 1 6个含芳硫基的新三唑类化合物 ,其合成路线如下 :RCCH2 BrO+HNNNB NRCCH2O NNHAC-Na ACBr2NRCCHOBrNN(1 ) (2 ) (3 )3 +SH 　R′B NRCCHOS　R′NN　 (4 )RCCH2 CH2 NMe2 .HClO+HNNNH2 O…     

GC-MS法测定粮谷及油料中55种有机磷农药残留量

采用ASE-300快速溶剂萃取仪提取样品中农药残留量,提取液经二氯甲烷液-液分配、凝胶色谱柱（GPC）净化,固相萃取柱（活性炭）再净化,浓缩定容后,用气相色谱-质谱仪（GC-MS）测定,外标法定量.采用选择离子检测进行阳性确证.选择玉米、糙米、大豆、花生为实验样品、敌敌畏等55种农药添加水平在0.5～2.00 mg/kg时,该方法回收率为68%～117%;精密度为4.04%～11.76%;方法测定低限为0.005～0.100 mg/kg,各项指标均满足有关要求.     

Extended applications of electric cell-substrate impedance sensing for assessment of the structure-function of α2β1 integrin

Electric cell-substrate impedance sensing (ECIS) was applied to assess the structure-function of α2β1 integrin, receptor for collagen and laminin. On collagen-coated gold electrodes, expression of this integrin on human rhabdomyosarcoma (RD) cells (RDX2C2) yielded a five-fold increase in resistance when compared with mock transfected RD (RDpF) cells (34.5±5.2 versus 6.5±0.8 Ω/cell). An intermediate level of 16±2 Ω/cell was measured upon expression of an α2β1 mutant that lacked the α2 cytoplasmic domain (RDX2CO). On laminin, the resistance measured for RDX2C2 cells was also higher but only twice that of RDpF cells at 71±4 and 37±4 Ω/cell, respectively. In comparison, RDX2CO cells (38±4 Ω/cell), exhibiting no enhanced adhesive function, yielded a similar result to that of RDpF cells. On fibronectin, RDX2C2 and RDpF cells, exhibiting comparable levels of adhesion, were similar in resistance measurements at 85±5and 89±7 Ω/cell, respectively. It has been shown that deletion of α2 cytoplasmic domain results in dysregulated recruitment of the α2β1 mutant to focal adhesion complexes that mediate binding of fibronectin. RDX2CO cells on fibronectin, exhibiting reduced adhesive function, was associated with noticeably lower resistance (60±4 Ω/cell). Monitoring electroporation of the RD plasma membrane also indirectly validated cell attachment as reflected by the resistance measured. Results from this study demonstrated the potential of ECIS for study of the structure-function of βl integrin adhesion receptors.     

磁化作用对汽油动态挥发性影响的研究

用热重（TG）分析和自行设计的原位动态挥发实验，研究了在不同条件下汽油的挥发性，结果表明，磁化空气或磁化汽油都可提高汽油的挥发性，而汽油和空气共同磁化，可更大幅度地提高汽油的挥发性。     

超临界NaCl水溶液的分子动力学模拟

采用分子动力学模拟的方法对超临界NaCl水溶液的微观结构进行了研究.模拟发现在所研究超临界条件下,密度的变化比温度的变化对超临界NaCl水溶液的微观结构影响更大.温度及密度对Cl－ H2O径向分布函数的影响比对Na＋ H2O径向分布函数的影响要大.超临界条件下,各gNa＋－Cl－在0.261 nm处出现峰值,表明Na＋、Cl－之间发生了离子的缔合.超临界条件下,随温度增加,缔合作用增强；随密度增加,缔合作用减弱.本文工作为建立可适用于超临界条件下的电解质热力学模型提供了依据.