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1.
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%. 相似文献
2.
J.-P. Coudereau Marcel Debray Claire Monier Jean-Marie Bourre Henriette Frances 《Psychopharmacology》1997,130(2):117-123
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 相似文献
3.
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。 相似文献
4.
5.
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 总被引:2,自引:0,他引:2
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。 相似文献
6.
不同培养基对肠球菌检出率的影响 总被引:3,自引:1,他引:2
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 相似文献
7.
8.
表皮干细胞的快速高效分离 总被引:2,自引:0,他引:2
目的 寻找一种快递高效分离组织工程化皮肤种子细胞-皮肤干细胞的方法.方法 取成人手术切除之包皮,利用Ⅰ型胶原酶结合胰蛋白酶消化法,快速分离表皮干细胞,并对其进行鉴定及相关的生物学特性的研究.结果 应用Ⅰ型胶原酶结合胰蛋白酶,可在3小时内快速分离到表皮干细胞及成纤维细胞,经流式细胞仪及细胞免疫荧光鉴定,表皮细胞群体中角蛋白19(K19)阳性表达的细胞即表皮干细胞约占18%,但是其体外短期扩增仍较困难.结论 利用胶原酶消化法可在短期内高效分离到用于构建组织工程化皮肤的种子细胞,这为快速构建组织工程化皮肤提供了可能. 相似文献
9.
10.
A One–Step, Operator–Independent Method for Isolating Islets of Langerhans from the Porcine Pancreas
Christophe Arbet–Engels Sylviane Darquy Frédérique Capron Maria E. Pueyo Sophie Dimaria Vincent Poitout Gérard Reach 《Artificial organs》1994,18(8):570-575
Abstract: Large–scale isolation of islets of Langerhans is one of the major obstacles in islet transplantation. Until now, isolation methods relied on enzymatic digestion, the duration of which relies on a decision dictated by the operator's experience. This approach has always hindered development of an automated method. The aim of this study was to develop a one–step method based on complete digestion of the pancreas. The original aspect of the technique (derived from the Ricordi method) is use of the University of Wisconsin (UW) solution in the digestion medium and a continuous flow collagenase processing circuit with local cooling and rewarming to allow tissue digestion to proceed at 37°C while settling of the cell suspension takes place at 4°C. A stopcock system permits the alternate use of two settling chambers so that while one is in the circuit, the other can be removed for cen–trifugation, resuspension of the crude islet preparation in collagenase in free UW solution, and further purification in a density gradient system. Ten experiments were performed, and 545, 750 ± 48, 670 purified pig islets were obtained per totally digested pancreas. Histological studies showed cell integrity. Insulin secretion in response to double glucose stimulation under perfusion conditions demonstrated the functional viability of the isolated islets. In conclusion, this one–step method makes it possible to obtain a high number of viable islets of Langerhans in the absence of any decision by an operator, and it should therefore provide basis for an automated method. 相似文献