首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 93 毫秒
1.
以醋酸乙烯酯(VAc)为主单体,二乙烯基苯(DVB)为交联剂,聚乙烯醇(PVA)为分散剂,采用悬浮聚合法制备了交联微球VAe/DVB.重点考察了分散剂用量、搅拌速率、油水两相比例、NaCl用量等因素对交联微球的形成及其粒度的影响.使用甲醇对微球VAc/DVB进行醇解反应,制得了聚乙烯醇交联微球VA/DVB.结果表明:交联微球VA/DVB的物理形态决定于前驱体微球VAc/DVB的形貌与粒径.在悬浮聚合体系中,分散剂用量、搅拌速率与油水两相比是影响交联微球制备的主要因素,当分散剂用量太少(<0.3%)、搅拌速率太慢(<200 r/min)与油水两相体积比太大(>l:4)时,共聚合体系中均不能发生成球过程.控制悬浮聚合的反应条件,可以制备出球形度好、粒径可调控的交联微球VA/DVB.影响醇解反应的主要因素是反应温度,适宜的温度是40℃,反应15 h醇解度可达92%.  相似文献   

2.
目的 探讨制备水溶性L-半胱氨酸的分子印迹微球的方法.方法 以L-半胱氨酸为模板分子,2-丙烯酰胺-2-甲基丙磺酸为功能单体,三羟甲基丙烷三甲基丙烯酸酯为交联剂,在水相中采用悬浮聚合法制备分子印迹聚合物微球.对聚合反应中温度和分散剂的用量进行研究.结果 分子印迹微球对L-半胱氨酸具有一定的吸附性能,温度和分散剂用量影响微球粒径.结论 悬浮聚合法合成的分子印迹聚合物微球粒径可控、均匀,随着分散剂的浓度或者温度升高,粒径越小.  相似文献   

3.
采用苯乙烯(St)、甲基丙烯酸甲酯(MMA)、偶氮二异丁腈(AIBN)为引发剂,聚乙烯基吡咯烷酮(PVPK30)为分散剂,无水乙醇和去离子水混合溶液为分散介质,三羟甲基丙烷三甲基丙烯酸酯(TMPTMA)为交联剂,以饥饿态加料方式加入第2种单体,用单分散聚合法制备了粒径分布窄、平均粒径为3~4 μm的聚苯乙烯甲基丙烯酸甲酯(P(StMMA))交联微球,并对微球表面进行化学镀镍,成功获得了磁性微球。采用扫描电镜,结合X射线能谱仪等仪器对化学镀镍前后微球的形貌和成分进行分析,探讨了最佳化学镀镍工艺条件为:胶体钯活化液活化,酸性镀液配方B、pH=6.0,镀液注入速率0.5 mL/min,此时获得的镀球表面平整度好,包覆完全,且Ni与基材结合力强,在离心和超声条件下镀层不易脱落或开裂。最佳工艺条件下获得的镀球NiP(StMMA)的平均密度为2.3~2.5 g/cm3,同时具有高分子微球质量轻和镍的磁性优点。  相似文献   

4.
通过无皂乳液聚合方法制备了单分散性好的丙烯酸甲酯(MA)-二乙烯苯(DVB)交联微球。研究了引发剂、单体、交联剂的用量、温度、搅拌速率、离子强度对聚合反应速率和微球粒径的影响。得到了外形较规则、粒径为730nm左右、分布均匀的交联丙烯酸甲酯-二乙烯苯微球,其制备条件是:以双蒸馏水为反应体系,C(MA)0=0.871mol/L,C(DVB)=0.067mol/L,T=70℃,转速为300r/min,  相似文献   

5.
交联共聚淀粉微球对阿司匹林吸附性能的研究   总被引:2,自引:0,他引:2  
目的:研究交联淀粉微球CSMs对阿司匹林的吸附性能,探讨引发剂用量、交联剂用量、反应温度和反应时间等因素对吸附量的影响规律.方法:以可溶性淀粉为原料,K2S2O8-Na2SO3为引发剂,N,N'-亚甲基双丙烯酰胺为交联剂,在反相悬浮体系中合成交联共聚淀粉微球CSMs;以CSMs为吸附载体,在阿司匹林乙醇溶液中进行吸附实...  相似文献   

6.
以苯乙烯为单体、二乙烯基苯为交联剂,通过优化反应条件,制备了平均粒径为3.28~9.04 μm的单分散聚苯乙烯微球和平均粒径为6.60 μm的单分散交联聚苯乙烯微球.探讨了单体浓度、引发剂含量、分散稳定剂用量对微球粒径和分散性的影响.热稳定性分析表明:交联聚苯乙烯微球耐热性明显优于线性聚苯乙烯.  相似文献   

7.
本文用溶剂蒸发法制备了月桂醇缓释微小球。阐述了微球粒径与搅拌速度、温度、核心材料与基质材料比例以及乳化剂浓度、油水相体积比等制备条件的关系。测定了它在乙醇介质与空气中的释放速率;证明了它的释放机制属于整体型扩散渗透体系并用扫描电镜(SEM)观察了微球表现形态。  相似文献   

8.
目的:制备甲磺酸帕珠沙星缓释微球,探索制备工艺对微球性能的影响。方法:以壳聚糖、明胶为缓释载体材料,采用正交设计,以药物与辅料比、水油相比、交联剂用量及搅拌速率为考察因素,以载药量、包封率、外表形态及平均粒径为指标,筛选最佳工艺条件。结果:优选工艺为A2B3C3D2,即药物与辅料比为25%、水油相比为10%、交联剂用量为15%、搅拌速率为800 r/min。结论:所得微球外表形态良好,包封率高,工艺稳定。  相似文献   

9.
以乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,采用悬浮聚合法制备了平均粒径为100 μm的交联聚甲基丙烯酸缩水甘油酯(CPGMA)微球,然后通过胺基与环氧键之间的开环反应,将聚乙烯亚胺(PEI)偶合接枝在微球表面,制得了表面接枝PEI的功能微球PEI-CPGMA.研究了功能微球对胆红素的吸附性能,考察了接枝度、介质pH、离子强度等因素对微球吸附性能的影响.静态吸附实验结果表明:功能微球对胆红素具有强吸附能力,等温吸附满足Freundlich吸附方程,饱和吸附量可达14.1 mg/g;介质的pH对微球吸附性能有很大的影响,在近中性(pH=6)溶液中,接枝微球对胆红素的吸附能力最强,而在酸性与碱性溶液中吸附能力都比较弱;离子强度对吸附作用表现出微弱的增效作用;微球表面PEI的接枝度越高,吸附能力越强.  相似文献   

10.
单分散,大粒径聚苯乙烯微球的研制   总被引:1,自引:0,他引:1  
制备可用于清除骨髓中癌细胞的磁性微球。以苯乙烯为单体,二乙烯苯为交联剂,采用二步溶胀法合成单分散,大粒径的聚苯乙烯高分子微球。合成了粒径为3.57μm分散度为0.077的聚苯乙烯微球,并可方便地得到多孔和交联微球。活性溶胀乳剂乳滴的大小、丙酮的含量对活性溶胀效果有较显著的影响、活性溶胀乳剂的种类搅拌速度,单体加入量是影响微球性质的主要因素。  相似文献   

11.
Objective: To evaluatel the value of D-dimers in patients with acute aortic dissection (AAD). Methods: This study consisted of 16 patients with AAD and 27 non-AAD patients. Serum D-dimets were measured by Sta-Liatest D-DI immunoturbidimetric assay. Results: D-dimer level was higher (P < 0.001) in patients with AAD(7.91 ± 5.52 μg/ml) than that in non- AAD group(1.57±1.24 μg/ml). D-dimer was positive (>0.4 μg/ml) in all patients with AAD and in 10 control group patients (37%). Among patients with acute AAD, D-dimers tended to be higher in Stanford A than in Stanford B (8.67 ± 4.31 μg/ml vs. 3.24±1.27 μg/ml, P <0.01). D-dimer values tended to be higher in more extended disease(3.84 ± 1.65 μg/ml, 8.57 ± 3.58 μg/ml and 11.87 ± 5.69 μg/ml in thoracic aorta, thoracic and abdominal aorta, thoracic and abdominal aorta and iliacal arteries, respectively, P < 0.05 for both 8.57 ± 3.58 and 11.87 ± 5.69 vs. 3.84 ± 1.65 ). Including the control group into the analysis, we found a sensitivity of 100%, a negative predictive value of 100%, and a specificity of 66% and a positive predictive value of 64% for D-dimer in diagnosis of AAD in our patients with suspected AAD. Conclusion: D-dimer was elevated in patients with AAD. A negative D-dimer test result could be useful in excluding AAD.  相似文献   

12.
Objective: To set up a simple and reliable rat model of combined liver-kidney transplantation. Methods: SD rats served as both donors and recipients. 4℃ sodium lactate Ringer's was infused from portal veins to donated livers,and from abdominal aorta to donated kidneys, respectively. Anastomosis of the portal vein and the inferior vena cava (IVC) inferior to the right kidney between the graft and the recipient was performed by a double cuff method, then the superior hepatic vena cava with suture. A patch of donated renal artery was anastomosed to the recipient abdominal aorta. The urethra and bile duct were reconstructed with a simple inside bracket. Results: Among 65 cases of combined liver-kidney transplantation, the success rate in the late 40 cases was 77.5%. The function of the grafted liver and kidney remained normal. Conclusion: This rat model of combined liver-kidney transplantation can be established in common laboratory conditions with high success rate and meet the needs of renal transplantation experiment.  相似文献   

13.
FOR anesthesiologis s ,treatingpostoperativepainhas alwaysbeen a problem.Althoughopioidshave been provedtobe effective,theirsideeffectscouldnotbeignored.With thedevelopmentofscienceand pharmacology,many drugs with aspectsof satisfactoryanalgesicefficacyand couldbe welltoleratedby patientshave been developed.And lornoxicamisone of them, which isa non-steroidalanti-inflammatorydrug (NSAID ), with analgesic, anti-infl-ammatory,andantipyreticproperties.Itseliminationhalf-time(3 to 5 hours) isle…  相似文献   

14.
Shock wave lithotripsy (SWL) is a treatment of choice for upper urinary stones. However, this procedure is inappropriate for obese patients because the focus is often unable to reach the target owing to the limited focal distance in shock wave source. Although treating such patients in a blast path may increase the application length of shock wave source, it's difficult to find this path on the lithotripter monitor. For this reason, we invented an adjustable calibration marker in order to set an effective focus in the shock wave hath.  相似文献   

15.
Excess production of reactive oxygen species(ROS)of mitochondrion mediated by hyperglycemia is the common pathogenesis of angiopathic complications of diabetes.TCM holds that the damp from the dysfunction of spleen.kidney and liver is the causative factor of complications of diabetes.This is similar to the mechanism of Ros resulting in angiopathic complications of diabetes.When the angiopathic complications of type II diabetes mellitus(T2DM)are difierentiated as caused by turbid damp in TCM can be explained as ROS.Since the obstruction of pathogenic damp in channels and collaterals is said to be the main pathogenesis,the treating principle should be dissolving the damp to remove the obstruction.  相似文献   

16.
INTRODUCTION Obesity is a complex emergent problem, which can be possibly solved not only by the diet but also by the life style and promotion of a constant physical exercise. 1, 2 No doubt careful attentions must be given to the nutritional condition of obese people, the dietary habits, the somatic build (i.e. distribution of fat mass) and the organic functions linked to formation of the fat mass. All the parameters should be constantly monitored before, during and after a diet treatment. 3, 4, 5  相似文献   

17.
People with dysglycemia are at high risk for atherosclerotic diseases. This study aims at investigating the atherosclerotic vascular damage in dysglycemia and its metabolic origin in Tibetan population.  相似文献   

18.
Objective: To observe the therapeutic effects in acupunture treatment of primary dysmenorrhea combined with spinal Tui Na, and study its mechanism. Methods: Thirty cases of the treatment group were treated by acupuncture combined with spinal Tui Na, and thirty cases in the control group were treated by routine acupuncture. Results: The total effective rate was 93.3% in the treatment group, and 73.3% in the control group, with a significant difference between the two groups (P<0.05). Conclusions: Acupuncture combined with spinal Tui Na has good prospects for treatment of primary dysmenorrhea.  相似文献   

19.
In treating chronic nephropathy,Luo Lingjie,a chief physician,pays attention to regulating the balance between yin and yang,treating infection if present,and removing pathogenic factors.He prescribes gentle drugs and uses carefully strongly warming-tonifying ones,emphasizes the importance of persuading the patient to persist in treatment with medication and nurse one's health for recuperation,and is good at combined use of TCM and western medicine therapy and brings the merits of various therapies into full play,with obvious theraoeutic effects.  相似文献   

20.
Dr.Zhang Ren,the chief physician,is the chairman of Shanghai Acupuncture and Moxibustion Association.Having been engaged in medicine for about 40 years,he is experienced in treating various intractable diseases.In his long years of clinical practice,he advocates taking the TCM differentiation as the basis to seek for the acupuncture method for treatment of modern intractable diseases.The author of this essay had the fortune to follow Dr.Zhang in study.The following is a summary of Dr.Zhang's experience in the acupuncture treatment for different intractable diseases with the same therapeutic principle.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号