共查询到20条相似文献，搜索用时 265 毫秒
1.
采用乳化-交联法研究了左氧氟沙星磁性明胶微球的制备及其缓释性能.选取左氧氟沙星与明胶的比例、水油比、明胶浓度、戊二醛用量四个因素进行正交实验,优化最佳合成工艺.采用动态透析法测定载药微球的体外释放特性,同时对载药微球的形态、粒径、磁性及包覆情况进行表征.结果表明,载药微球最佳制备工艺为:明胶浓度15%,左氧氟沙星明胶比1∶2,水油比1∶5,戊二醛用量3.6mL;包封率为8.89%,载药量为51.36%;微球5h体外累积释药百分率人工肠液中达到64%,人工胃液中达到72%,具有较好的缓释性能,体外释放符合一级动力学方程;磁性明胶微球成球性良好,分布均匀,Fe3O4及左氧氟沙星被明胶包覆. 相似文献
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目的:探索白藜芦醇羧甲基壳聚糖微球的最优处方。方法:采用乳化交联法制备微球,以成球性、载药量、包封率为评价指标,应用单因素和正交设计试验优化工艺处方。结果:优化所得处方为:白藜芦醇与羧甲基壳聚糖质量比为1∶1,羧甲基壳聚糖浓度3.5%,溶液p H 7,司盘-80用量6%,固化剂用量为1m L。优化处方制备的微球近似呈球形,表面较光滑,载药量、包封率分别为22.7%和45.4%,微球粒径在10~100μm范围内。结论 :该处方制备出的微球具有较好的载药量和包封率。 相似文献
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PLGA载多柔比星磁性纳米微球的制备与表征 总被引：2，自引：0，他引：2
董鑫 《常熟理工学院学报》2008,22(10):43-45
采用复乳法制备了PLGA载多柔比星磁性纳米微球,并对其形貌、粒径、磁性、包封率、载药量等特性进行了表征．实验结果证明,微球形貌良好,粒径分布在20±5nm范围内,在乳液中分散均匀,具有一定的磁性,微球包封率为41．2％,载药量为0．4％．微球制备方法简便易行,效果良好,各项特性指标符合药物载体要求,在生物活体癌症靶向治疗中具有潜在应用价值． 相似文献
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采用乳化溶剂挥发法、基因重组和蛋白纯化技术，制备了穿膜肽修饰的3-羟基丁酸-3-羟基己酸共聚酯(PHBHHx)负载紫杉醇(PTX)递药系统。通过调控乳化剂的种类、用量、包封材料与药物比例优化了纳米微球的尺寸、药物包封率及载药量，并对递药系统的尺寸、形貌进行了表征。结果表明：水包油型乳化剂选用0.5 mL的吐温-20、水相乳化剂选用60 mL(1%)聚乙烯醇，微球尺寸达到150 nm左右时，均匀性良好；PTX与PHBHHx比例为1∶50时，药物包封率及载药量达到最优，分别为81.02%和50.9 mg/g;递药系统分散度好，表面略显粗糙，基本呈球形，粒径约为150 nm。在最优条件下制备的PTX载药系统粒径较小，包封率较高，易实现功能化蛋白修饰，为PTX纳米药物提供了一种新的设计思路。 相似文献
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探索滁菊挥发油微囊的最佳制备工艺。采用复凝聚法制备滁菊挥发油微囊,以外观形态、粒径、包封率、载药量为指标,正交设计优选工艺条件。滁菊挥发油微囊的最佳制备工艺条件为:复合胶与挥发油的比例为1∶1,温度为55℃,p H为4.0,固化剂量为1.5m L。制得的滁菊挥发油微囊形态呈圆形、光滑,粒径分布在80~120μm,平均包封率为(48.89±5.93)%,平均载药量为(13.11±2.30)%,TLC法显示供试品溶液与对照品溶液在相同的位置出现相同斑点。该制备方法操作简单易行,处方合理,制得微囊外观圆整,载药量和包封率较高。 相似文献
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《赤峰学院学报(自然科学版)》2017,(3)
恶性肿瘤是近代威胁人类健康的重大疾病之一,改变给药方式是目前抗肿瘤药研究的一个发展趋势,多孔微球作为一种药物新剂型,在药物新制剂的研发以及新剂型的改造方面应用广泛.本文以抗肿瘤药物紫杉醇为模型药物,聚乳酸羟基乙酸(PLGA)为载体,采用复乳溶剂挥发法(W/O/W)法制备载紫杉醇PLGA多孔微球.实验采用扫描电子显微镜、体外释放等方法评价载药多孔微球的性能;采用MTT法评价该载药微球体外对A549人肺癌细胞的抗肿瘤活性.实验显示,载紫杉醇PLGA多孔微球对A549人肺癌细胞生长具有明显的抑制作用.上述结果表明实验所得载药多孔微球具有良好的药物缓释特性及抗肿瘤效应,是一种具有良好应用前景的肺部给药载体. 相似文献
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以壳聚糖为载体、盐酸左氧氟沙星为目标药物,采用乳液聚合法制备出壳聚糖盐酸左氧氟沙星载药微球;考察了载药微球的体外释放性能并将该载药微球进行小鼠灌胃给药研究.结果表明:该制备方法简单可行,且小鼠急性毒性较低. 相似文献
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冷冻干燥法制备隐丹参酮纳米脂质体 总被引：1，自引：0，他引：1
张晓伟 《忻州师范学院学报》2008,24(5)
目的：用大豆卵磷脂作为载体,以隐丹参酮作为模型药。制备隐丹参酮纳米脂质体。方法：用超声一匀浆一冷冻干燥法制备隐丹参酮纳米脂质体。采用透射电镜测试隐丹参酮脂质体的粒径,用激光粒度分布仪测试平均粒径及粒度分布。结果：冷冻干燥法制备隐丹参酮纳米脂质体的粒径20—80nm之间。随着大豆卵磷脂与隐丹参酮配比的减小,粒径逐渐减小,包封率逐渐减小。体外释药表现为零级动力学释药特征。结论：用超声一匀浆一冷冻干燥法制备隐丹参酮纳米脂质体的方法可行。 相似文献
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以液体石蜡作连续相,Span-80作乳化剂,以戊二醛为交联剂,在W/O型乳化体系中制备一种新型微球—卡铂壳聚糖/葡甘聚糖复合微球,探讨了制备工艺条件对微球形状性能的影响;通过显微镜观察,药物包裹率测定,药物释放量检测等分析了微球特性,评价了微球中卡铂的缓释性能.结果表明:制备的复合微球球形良好,球体表面光滑,微球中卡铂的包封率为39.13%,微球中的卡铂在生理盐水中具有一定缓释性能. 相似文献
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Wilfrid Bilodeau 《Interchange》1993,24(3):241-270
Résumé Cet essai évoque les contextes pédagogiques de l'écriture au-delà des formes d'écriture convenues en recherche, et questionne les usages scolaires de l'écriture. J'y suggère d'autres usages inspirés d'une approche qui inverse les rapports usuels entre communication et représentation, entre kinésis et mimésis. Cette approche vise une démystification du pouvoir de l'écriture à représenter le réel, à dominer la communication, et une promotion d'une écriture expressive et métaphorique, favorisant l'appropriation de cette technologie virtuellement libérante.Université Laval 相似文献
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Mother's Day--母亲节 Mother's Day falls on the second Sunday in May every year. This is the occasion we show appreciation to our mothers and to people who have worked so hard to take care of us. Today, I'm sharing thoughts from a friend about mother, love,and the study of English. When we were young students, a teacher touched our heart,and we all miss her very much on this special day in May. 相似文献
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邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
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Kate Lorenz 《海外英语》2007,(12):40-41
Whether your preferred destination is the executive suite or simply the nearest exit from your current position, don't let your job take you aimlessly down any path. In fact when it comes to career planning, don't think in terms of "jobs" at all, says corporate transitions expert William Bridges, Ph.D. Instead he suggests building your career plan on "doing the work you're best at for the employers who need it." 相似文献
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Rachel Zupek 《海外英语》2007,(11):40-41
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了 相似文献
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YANGShiguo 《重庆大学学报(英文版)》2004,3(1):86-88
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex. 相似文献
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GUO Bao-feng Xiao Da-wei 《重庆大学学报(英文版)》2005,4(3):129-133
Using virtual reality for interactive design gives a designer an intuitive vision of a design and allows the designer to achieve a viable, optimal solution in a timely manner. The article discusses the process of making the Virtual Reality System of the Humble Administrator＇s Garden. Translating building data to the Virtual Reality Modeling Language （VRML） is by far unsatisfactory. This creates a challenge for computer designers to do optimization to meet requirements. Five different approaches to optimize models have been presented in this paper. The other methods are to optimize VRML and to reduce the file size. This is done by keeping polygon counts to a minimum and by applying such techniques as object culling and level-ofdetail switching. 相似文献
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The awareness of individualism can be traced back to the period of American Revolution when the Declaration of Independence was produced.It expressed basic beliefs concerning freedom,equality,democracy,privacy and the relationship between people and government,which were exactly what the philosophy of individualism mostly dealt with at that time.This paper is to exploit the essence of individualism by analyzing the Declaration .The analysis enables us to reconsider its significance to the issue of America human rights and foreign policies. 相似文献
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李晓劲 《读与写:教育教学刊》2008,5(6)
Public speaking, as one kind of speech act, the speaker uses some pragmatic strategies, for example,the use of personal pronoun, in order to achieve effective communication. Speakers use the first personal pro-noun we and the second personal pronoun you conventionally, also there are some deviations in the use of person-al pronouns. However, theses kinds of uses have to be explained and understood in such a specific context. 相似文献