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排序方式: 共有340条查询结果,搜索用时 31 毫秒
1.
Isolation and subfractionation of human peripheral blood mononuclear cells (PBMC) by density gradient centrifugation on Percoll 总被引:7,自引:0,他引:7
The use of Percoll for isolation and subfractionation of PBMC and T-lymphocytes by discontinuous and continuous density gradient centrifugation is described: PBMC were isolated from human peripheral blood by discontinuous density gradient centrifugation on Percoll. The use of Percoll instead of Ficoll-Isopaque has the advantage that Percoll, in contrast to Ficoll-Isopaque, does not alter the density of monocytes. Therefore, a better separation of lymphocytes and monocytes was achieved after subsequent continuous density gradient centrifugation on Percoll. E-RFC were isolated by discontinuous density gradient centrifugation after a first low speed centrifugation step banding lymphocytes and SRBC on a Percoll-Ficoll cushion, and a subsequent high speed centrifugation step separating high density rosettes and SRBC from low density non-E-RFC. The advantage of this procedure is the short time of performance and that there is no need to resuspend the lymphocyte/SRBC pellet. PBMC, nph.PBMC T-lymphocytes were further subfractionated by continuous density gradient centrifugation on Percoll. The method described here resulted in a good separation of lymphocytes and monocytes. However, to obtain lymphocyte fractions with minute numbers of contaminating monocytes, a depletion of monocytes prior to further subfractionation of the lymphocytes by continuous density gradient centrifugation is recommended. A marker analysis of T-lymphocytes subfractionated by continuous density gradient centrifugation on Percoll shows that high density T-lymphocytes are enriched in ANAE positive lymphocytes of type 1 and depleted of ANAE positive lymphocytes of type 2. Low density T-lymphocytes are enriched in ANAE type 2 cells and depleted of ANAE type 1 cells. On the other hand, no considerable differences were found when analyzing the T-cells from different fractions for differentiation antigens by means of monoclonal antibodies (anti Lyt 3, OKT4, and OKT8). The results may indicate that subfractionation of T-lymphocytes by continuous density gradient centrifugation on Percoll provided T-cells in different functional states rather than T-cells of distinct subclasses. 相似文献
2.
PVP K30对葛根黄豆苷元增溶的研究 总被引:1,自引:0,他引:1
研究了葛根黄豆苷元(1)在不同温度、不同浓度的PVP K30—磷酸盐缓冲液中的溶解度,1溶解度随辅料浓度的增大而明显增大。溶解度数据经热力学方法处理,表明这是个自发过程。采用溶剂法,以PVP K30为载体制备1固体分散体,考察固体分散体中1的溶解度和溶出度。与其本身相比,固体分散体中1溶解度显著提高,溶出速度明显增大。 相似文献
3.
目的将五仁醇制成固体分散体,提高五仁醇中有效成分的体外溶出度。方法采用直接将载体材料溶于五仁醇提取液,然后除去溶剂的方法制备了多种五仁醇固体分散体,以五味子甲素为指标成分,研究并比较了它们的表观溶解度和体外溶出度。结果配比为1∶3的五仁醇-聚乙烯吡咯烷酮K 30(PVP K 30)固体分散体中有效成分的表观溶解度比五仁醇胶囊内容物显著提高,达到5.06μg/mL(水);溶出介质(水)中分散(包括溶解)的小于0.22μm的药物高达43.2%。结论五仁醇-PVP K 30固体分散体能明显提高五仁醇中有效成分的表观溶解度和体外溶出度。 相似文献
4.
《Drug testing and analysis》2017,9(5):778-787
This article reports on the analytical properties of five pyrrolidinyl substituted cathinones: α ‐pyrrolidinononaphenone (α ‐PNP, 1 ), 4‐chloro‐α ‐pyrrolidinopropiophenone (4‐Cl‐α ‐PPP, 2 ), 4‐chloro‐α ‐pyrrolidinovalerophenone (4‐Cl‐α ‐PVP, 3 ), 5‐dihydrobenzofuranpyrovalerone (5‐DBFPV, 4 ), and 2‐(pyrrolidin‐1‐yl)‐1‐(5,6,7,8‐tetrahydronaphthalen‐2‐yl)hexan‐1‐one (β ‐THNPH, 5 ). These identifications were based on liquid chromatography–quadrupole time‐of‐flight‐mass spectrometry (LC–QTOF–MS), gas chromatography–mass spectrometry (GC–MS) and nuclear magnetic resonance spectroscopy (NMR). To our knowledge, no analytical data about α ‐PNP, 4‐Cl‐α ‐PPP, 4‐Cl‐α ‐PVP, and β ‐THNPH have appeared until now, making this the first report on these compounds. Moreover, in order to study the collision‐induced dissociation (CID) characteristic fragmentation routes of pyrrolidinyl substituted cathinones, a total number of 13 pyrrolidinyl substituted cathinones were selected and discussed. The major fragmentation pathways under CID mode are produced, leading to the formation of characteristic ions. Product ions of [M‐C4H9N]+ and CnH2nN+ indicate the presence of pyrrolidinyl substitution. Characteristic fragments are also produced via the cleavages of the CH–N(CH2)4 bond and the CO‐CHN bond. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
5.
目的探讨单侧与双侧椎弓根入路经皮穿刺椎体成形术治疗骨质疏松性椎体压缩性骨折的临床疗效及价值。方法回顾分析2007年12月~2011年2月我院56例获得6个月以上随访的女性骨质疏松性单个椎体压缩性骨折的临床资料,其中采用单侧椎弓根t入路经皮穿刺椎体成形术治疗30例,双侧椎弓根入路经皮穿刺椎体成形术治疗26例,比较2组患者手术时间、骨水泥填充量、X线照射次数及术后VAS评分。结果单侧组手术时间(25±6)min显著少于双侧组(45±5)rain(t=-13.426,P=0.011)。单侧组骨水泥渗漏率10.0%(3/30),与双侧组3.8%(1/26)无显著差异(X^2=0.138,P=0.710)。单侧组术中X线曝光(10.5±2.5)次,显著少于双侧组(19.4±3.0)次(t=-12.110,P=0.000)。2组术后24h、术后6、12个月VAS评分无统计学差异(P〉0.05)。结论单侧与双侧椎弓根入路经皮穿刺椎体成形术治疗骨质疏松性椎体压缩性骨折均能取得良好效果。单侧穿刺方法手术时间短,X线暴露次数少;双侧入路穿刺方法手术操作相对简单。 相似文献
6.
开发了一种稳定的阿戈美拉汀晶型I的制备方法。该方法采用在无水乙醇-正庚烷溶剂体系下添加PVP或在无水乙醇-水体系下添加HPMC的抗溶剂结晶法来实现。通过不同溶剂体系下高分子材料种类的筛选、不同浓度高分子材料的影响及溶剂体系中良溶剂和抗溶剂比例的影响的研究,确定了制备阿戈美拉汀晶型I的工艺。通过加速稳定性实验和长期稳定性实验对比表明,采用加高分子材料制备方法得到的阿戈美拉汀晶型I,具有较好的稳定性。 相似文献
7.
Lizhen Cheng Ting Li Ling Dong Xiaoyu Wang Qiye Huo Haoyu Wang Zhujun Jiang Xinyu Shan Weisan Pan Xinggang Yang 《Journal of pharmaceutical sciences》2018,107(5):1434-1442
In this study, a bilayer osmotic pump tablet of flurbiprofen (FP) solid dispersions (SDs) was developed to increase the solubility of the poorly soluble drug and controlled drug release at a constant rate. Based on the investigation of thermodynamic properties the drug, the carrier, and the calculation of the solubility parameters, the FP-SD was prepared by hot-melt extrusion technique with the povidone (PVP) VA64 carrier. Then, central composite design-response surface methodology was used to evaluate the influence of factors on the responses. Consequently, PVP VA64 was selected as the carrier for preparing FP-SD. The results of differential scanning calorimetry and X-ray confirmed that FP in FP-SD was in an amorphous state. FTIR indicated that the intermolecular hydrogen bond probably formed between FP and PVP VA64 in FP-SD. Correlation of release profiles to zero-order kinetics was significant (R2 = 0.9939). The mathematical models had good predictability because the deviation was less than 1% between the predicted value and measured value. These results demonstrated that FP-SD osmotic pump tablets successfully increased the solubility of FP and controlled the release of FP at a constant rate. 相似文献
8.
目的探讨帕金森病(Parkinson's disease,PD)苍白球腹后部毁损术(posteroventral pallidotomy,PVP)后再行丘脑底核(subthalamic nucleus,STN)脑深部电刺激术(deep brain stimulation,DBS)的可行性、术中电生理学特点和治疗结果。方法应用MR和微电极记录技术进行靶点定位,对12例单侧PVP术后症状再次加重的PD患者实施STN-DBS手术,其中4例行毁损灶对侧的STN-DBS,8例行双侧STN-DBS。结果STN-DBS对本组12例PD患者症状有不同程度的改善,双侧STN-DBS的效果尤为明显,术后3个月的UPDRS运动及ADL评分较术前明显减少(P<0.05或0.01),美多巴的用量明显减少(P<0.01),无明显术后并发症。术中电生理记录显示毁损灶同侧的细胞放电明显低于正常情况。结论曾行单侧PVP的PD患者如面临二次手术,可以选择DBS手术,以双侧STN的DBS效果最好,可减少药物用量。 相似文献
9.
目的从分子微观角度研究复合材料的力学性能及其单组份间发生相互作用的本质。方法用分子动力学(molecular dynamics,MD)方法模拟研究聚乙烯毗咯烷酮(PVP)、聚乙烯醇(PVA)以及其混合体系PVP/PVA的力学性能、径向分布函数等性质。结果 PVP与PVA有机结合之后的混合体系PVP/PVA较纯PVP体系力学性能有了明显的提高,且复合材料的力学性能不受温度的影响;混合体系两单组份间的相互作用主要是通过PVP分子单元中的氧原子与PVA中的羟基形成较强的氢键作用。结论 MD分析结果从分子层面揭示PVP/PVA复合水凝胶组份间相互作用机理,其力学性能较单组份PVP水凝胶有较大提高且不受温度影响;为临床制备水凝胶假体组织及其理化性能研究提供了一种可靠的理论研究方法。 相似文献
10.