Isolation and characterization of cellulose from date palm tree spathe sheath

This study deals with a series of operations to isolate the micro-cellulose from the palm tree spathe sheath by using a modified chemical method to take into account the low cost and the completion speed and its characterization using X-ray diffraction technique (XRD), infrared spectroscopy (FTIR) and scanning electron microscope coupled with element analyzer (SEM/EDX). The results showed that the extraction method succeeded in obtaining very pure microscopic fibers with a width of 2–10 μm with a crystallinity index equal to 79.21%, containing the two cellulose features Iβ and II, that, the conversion ratio of the first to the second was estimated at 32, 87%.     

Isolation impairs place preference conditioning to morphine but not aversive learning in mice

Morphine (8–100 mg/kg IP) induces place preference conditioning in mice. The effect of two different periods of isolation (15 and 30 days) was examined. Mice isolated for 15 days but not 30 days exhibited place preference conditioning to morphine (8 mg/kg). After 30 days of isolation morphine could not induce place preference conditioning with the following doses (8, 16, 64, 100 mg/kg). Social regrouping of male mice previously isolated for 30 days with naive female mice for 15 or 30 days resulted in a reappearance of the conditioned place preference to morphine (16 mg/kg). The specificity of this associative deficit was examined by testing learning in isolated compared to non-isolated mice in two distinct settings: escape learning in the Morris water maze and passive avoidance acquisition and retention. On the Morris water maze isolated mice did not differ from non-isolated mice regarding place learning, the probe trial or extinction. Isolated mice were unimpaired in passive avoidance acquisition and retention. It was concluded that the deficits in place preference conditioning were not the result of a global learning impairment in isolated mice. Received: 10 April 1996 /Final version: 20 September 1996     

一种较好的RNA分离制备方法及其在人胚RNA提取中的应用

以钒基核苷酸复合物为核酸酶抑制剂,从人胚组织中制备总RNA,所得产品几乎不含DNA和蛋白质,经过分离Poly(A)~ mRNA,证明制品有合成cDNA的完整功能,方法比较简捷,适于大量制备以满足分离mRNA 之需,并讨论了此法的优缺点。     

电气隔离在医疗设备控制系统上的应用

对医疗设备电气控制线路的各种隔离进行了详尽的分析讨论，提出了抑制干扰而采取的电气隔离的技术措施，从而保证医疗设备的正常工作。     

藤茶多糖AGP-3的分离纯化与结构的初步鉴定

目的 对藤茶水溶性多糖进行分离纯化得到AGP-3组分,并对其结构进行初步的鉴定,为藤茶多糖结构与生物活性关系的研究奠定基础.方法 采用DEAE-Sephadex A-25、Sephadex G-200和HPLC对藤茶多糖分离纯化,并通过IR、GC、1HNMR和13CNMR分析对藤茶多糖AGP-3组分的结构进行了初步鉴定.结果 AGP-3重均分子量(Mw)为1.02×105 Da,含中性糖质量分数57.6%、糖醛酸32.3%、蛋白质3.5%.结论 藤茶多糖分离组分AGP-3为一种含蛋白质的复合多糖.     

竹叶柴胡化学成分的研究

目的：为了开发利用竹叶柴胡(Bupleurum marginatum Wall.ex DC.)天然资源，阐明其有效成分，对竹叶柴胡根进行了化学成分研究。方法：运用层析手段和波谱方法分离并鉴定化合物。结果：分离并鉴定13个化合物，它们的结构分别被鉴定为( )-anomalin(Ⅰ)，白花前胡丙素(( )-praeruptorin A)(Ⅱ)，(4)，( )3’-angeloyloxy-4’-keto-3’，4’-dihydroseselin(Ⅲ)，木糖醇(xyhtol)(Ⅳ)，柴胡色原酮A(saikoehromone A)(Ⅴ)，6”-O-乙酰基柴胡皂苷d(6”-O-acetylsaikosaponin d)(Ⅵ)，柴胡皂苷b4(saikosaponin b4)(Ⅶ)，柴胡皂苷a(saikosaponina)(Ⅷ)，柴胡皂苷d(saikosaponin d)(Ⅸ)，柴胡皂苷b2(saikosaponin b2)(Ⅹ)，柴胡皂苷c(saikosaponin c)(Ⅺ)，此外还有β-谷甾醇，β-胡萝卜甙。结论：化合物Ⅰ，Ⅱ，Ⅲ，Ⅳ，Ⅴ，Ⅵ，Ⅷ，Ⅹ均为首次从竹叶柴胡中分得，其中化合物Ⅱ和Ⅲ为首次从该属植物中分得。     

利用主客体分子包结现象选择分离蛇床子有效成分的方法

利用1,1,6-四苯基-2,4-已二炔-1,6-二醇(I)的包结能力,可简单而迅速地从蛇床子中选择分离出有效成分欧前胡素(2)和花椒毒素(3),收率分别为0.054%(2)和0.002%(3)。本文用UV,IR,¹HNMR和¹³CNMR验证了2和3的化学结构,并用HPLC检验了2和3的纯度。X-射线衍射晶体结构分析表明主体分子I与组分2靠氢键形成包结物,它们的摩尔比为1:2,氢键长为2.8612A。包结物晶体属单斜晶系,空间群为已P₂₁/C,晶胞参数:a=15.468(5)A,b=8.595(3)A,c=18.663(7)A,β=93.64(5)°,Z=4和R=0.088。     

不同培养基对肠球菌检出率的影响

用pH9.6葡萄糖肉汤、6.5％NaCl琼脂平板、3％—5％羊血琼脂平板三种不同培养基,从同一份样品中分离肠球菌,检出率有显著差别。pH9.6葡萄糖肉汤对检样选择性增菌后,再用6.5％NaCl琼脂平板分离肠球菌,其检出率明显高于现正普遍用于肠球菌初代分离的3％～5％血琼脂平板(P<0.05),也高于单纯使用6.5％NaCl琼脂平板(P<0.05);后两者间无显著差别(P>O.05)。属中种的构成在不同培养基上检出情况也不同。 关键词:培养基 肠球菌 检出率 肠球菌广泛存在于自然界,是水、空气、尘     

细菌素产生菌的筛选及其细菌素的分离纯化

从香肠中分离得到一株产细菌素的乳酸片球菌，其发酵液经硫酸铵沉淀，CM—Sephadex C50阳离子交换柱层析后，得到的细菌素样品通过SDS—PAGE证明是一条带，分子量约20．83ku，该细菌素对热及酸碱稳定，易被酶降解而失去活性，对许多革兰氏阳性茵有较强的抑制作用，而对革兰氏阴性茵、酵母和霉没有作用。