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1.
在左旋聚乳酸(PLLA)膜上采用朗格缪尔布洛杰特(LB)技术、浇铸和化学接枝的方法制备了左旋聚乳酸甲基端聚乙二醇(PLLAMPEG)共聚物微绒毛膜。通过原子力显微镜(AFM)和水接触角测量等方法考察了制备方法及条件对绒毛层性能的影响,对绒毛层的亲水性、稳定性和抗蛋白吸附性能进行了对比分析。结果表明:通过这3种方法均能获得较亲水的抗蛋白吸附表面。PLLAMPEG单分子LB微绒毛必须在热水中处理后才能牢固地黏附于PLLA膜上;浇铸的PLLAMPEG成膜性好,但遇水易脱落,稳定性差;紫外光催化接枝的微绒毛制备简便、铆接牢固,可用于医疗器械或生物埋置材料的表面修饰。  相似文献   

2.
以乙烯-丙烯酸(EAA)共聚物及聚乙二醇单甲醚(MPEG)为主要原料,通过酯化反应制备了一系列接枝共聚物EAA-g-MPEG,并将其与高密度聚乙烯(HDPE)共混制得改性薄膜。研究了反应条件对接枝反应的影响,通过FT-IR、TG、DSC等方法研究了接枝产物的结构及其热性能。结果表明,随着侧链MPEG分子量的提高,产物接枝率逐渐下降;随接枝率的提高及侧链长度的增长,产物热稳定性下降;随接枝率的提高,产物的结晶熔融峰向高温方向移动,结晶性变好;EAA-g-MPEG可有效改善HDPE的表面亲水性能,当其质量分数为10%时,可使改性HDPE薄膜的水接触角由105°降至59°。  相似文献   

3.
[摘要]目的 优化制备粒径小、稳定性好的靶向微泡前体-生物素化微泡,并评价其理化性质及显影效果. 方法 选用不同膜材料配比制备生物素化脂质微泡,进行分组(A-E组)对照研究,粒径分析仪、Malvern表面电位仪评价各组理化性质;选用不同溶酶液,分组(1~3组)评价对微泡稳定性的差异;超声诊断仪下观察各组生物素化微泡的显影效果.结果 在A-E组中,A、C、E 3组有较明显的差异(P<0.05):(1)西林瓶中可见脂质呈不同分层状态;(2)随DPPC的摩尔比不断增加,MPEG200、DPPA摩尔比不断减小,微泡的平均粒径逐渐减小,粒径分布逐渐均一,浓度逐渐增高,Zeta电位逐渐变小且更加稳定;(3)使用三羟甲基氨基甲烷,甘油,丙二醇复合溶酶液制备的微泡微相互融合慢、粒径变化小、破裂少、浓度降低少.结论 按DPPC:MPEG200:DPPA:DSPE-PEG2000-Biotin 90:5:5:10且选用复合溶酶液优化制备的生物素化脂质微泡是最佳的淋巴系统靶向脂质微泡制作前体.  相似文献   

4.
采用热压成型工艺制备了玻纤网格布增强聚碳酸酯(PC)复合片材,考察了铺层结构、铺层角、增强纤维面密度及基体薄膜厚度对复合片材拉伸性能的影响。结果表明,增强玻纤网格布与基体膜的交替叠层为适宜的铺层结构;拉伸性能随铺层角增大而下降;低面密度的玻纤网格布适宜制备低面密度的“薄型”复合片材;采用厚度较小的基体膜可以制得拉伸性能较好的复合片材。扫描电子显微镜(SEM)分析表明交替的铺层结构有利于基体对低面密度增强纤维的束内浸渍,从而提高片材的拉伸性能。  相似文献   

5.
[目的] 对开心散(KXS)粉碎过程中的温度变化及粉末粒径进行考察,比较由不同粉碎方式处理后KXS中成分的含量差异。[方法] 采用高效液相-二极管阵列检测器法(HPLC-PDA)定量分析5种非挥发性成分,顶空固相微萃取-气质联用技术(HS-SPME/GC-MS)定性定量分析挥发性成分。[结果] 在现代机器粉碎过程中所测温度最高(55 ℃),粉末粒径最小(973.74 nm),传统碾碎较传统捣碎制得的散剂粒径更小,两种方式在温度方面差异不大;HPLC-PDA研究结果表明:5种非挥发性成分中,传统碾碎制得的KXS含量最高,现代机器粉碎制得的KXS含量最低;HS-SPME/GC-MS技术从KXS中共鉴定出56种共有化合物,其中传统捣碎占比93.19%,传统碾碎占比94.16%,现代机器粉碎占比94.04%,可分为8类,其中醚类占比最高(80.38%),萜类种类最多(36种)。[结论] KXS经不同粉碎方式制得后,在成分含量上存在一定差异,其中传统碾碎制备的KXS可较大程度保留其成分。两种检测方法操作简便,实用可靠,为KXS的质量控制研究提供参考。  相似文献   

6.
采用界面聚合法制备了聚苯胺纳米纤维,详细研究了不同氧化剂/单体摩尔比和盐酸浓度对制得聚苯胺的形貌、分子结构和电导率的影响。结果表明:界面聚合过程中,较低的氧化剂/单体摩尔比(≤1:4)和较高的盐酸浓度(≥1mol/L)有利于生成结构规整和较高电导率的聚苯胺纤维;而在氧化剂用量较高和盐酸浓度较低时,聚苯胺纤维形成的同时,伴随着吩嗪类物质和苯胺齐聚物的生成,产物呈现聚集结构,其电导率也较低。  相似文献   

7.
刘艳华  周成铭  杨彤 《医学教育探索》2018,31(3):255-260,272
首先以脱氧胆酸(DOCA)和三苯甲基组氨酸甲酯盐酸盐(H-His(Trt)-OMe·HCl)为反应物,经催化剂缩合制得DOCA-His(Trt)中间体。然后将透明质酸(HA)经N-羟基琥珀酰亚胺(NHS)和1-乙基-(3-二甲基氨基丙基)碳酰二亚胺盐酸盐(EDC·HCl)活化形成活性酯。最后将活性酯接枝DOCA-His(Trt)中间体,制得HA-DOCA-His(Trt)聚合物,脱Trt保护,制得HA-DOCA-His聚合物。采用FT-IR鉴定HA-DOCA-His的化学结构,并评价其溶血性和pH敏感性,通过超声法制备载紫杉醇的HA-DOCA-His胶束,并以透析法考察其体外释药行为。采用MTT法考察胶束的细胞毒性。结果表明,HA-DOCA-His溶血性与聚氧乙烯蓖麻油(Cremophor EL)相当,远远低于Tween 80;载紫杉醇的HA-DCA-His胶束在模拟内涵体环境中具有触发释药行为;相比于紫杉醇溶液,HA-DOCA-His载药胶束在模拟内涵体pH环境下表现出高效抑制MCF-7肿瘤细胞的增殖作用;HA-DOCA-His胶束可作为CD44受体和内涵体pH敏感的多靶向胶束载药系统,用于难溶性抗肿瘤药物的肿瘤靶向递药和胞内靶向释药。  相似文献   

8.
采用4,4'-二苯基甲烷二异氰酸酯(MDI)和聚乙二醇(PEG)为原料,制备端异氰酸酯基聚氨酯(PU)预聚体,用该预聚体对已合成的三官能度环氧树脂(TEP)进行改性。通过红外光谱分析(FT-IR)、扫描电镜(SEM)、热重分析(TG)和动态热力学分析(DMA)表征了交联物(TEP-PU)的基团变化、断面形貌、热性能和动态性能。研究表明:PU链段成功连接到TEP分子链上;当m(PU)∶m(TEP)=5%时,TEP-PU固化物的巴氏硬度为41.4 HBa,冲击强度为23.32 kJ/m2,玻璃化转变温度有明显提升,改性的TEP断面呈现韧性断裂。  相似文献   

9.
讲授法的教育心理学辨析──奥苏伯尔的有意义言语学习理论简介杨善发(安徽医科大学卫生管理学院230032)在世界范围的教育改革浪潮中,具有悠久历史的讲授法受到了严厉批判。这样的教学被贬为“填鸭式”、“注入式”和“鹦鹉式”教学;是“封闭型”教学方法的典型...  相似文献   

10.
以六水合氯化镁(MgCl2·6H2O)和氢氧化钠(NaOH)为原料,硬脂酸为改性剂,采用“一步法”制备改性氢氧化镁阻燃剂,研究了反应温度、反应时间和陈化时间对其活化指数和吸油率的影响;采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、激光粒度仪(LPSA)和热重分析仪(TGA)对其特性进行了表征,并在聚丙烯(PP)中进行了初步应用研究。结果显示其最佳制备工艺为:在反应温度80 ℃、反应时间90 min、陈化时间90 min下,制得的改性氢氧化镁阻燃剂分散性高,与聚丙烯(PP)的相容性好,其填充量为50%的PP混合物的热学性能优良,氧指数达到28.5,垂直燃烧等级为V 0级。  相似文献   

11.
Objective To observe blood pressure change with age in salt-sensitive teenagers whose salt sensitivity were determined by repeated testing.Methods Salt sensitivity was determined through intravenous infusion of normal saline combined with volume-depletion by oral diuretic furosemide in 55 teenagers. After five years, salt sensitivity was re-examined and subject blood pressure was followed up. Blood pressure changes in salt-sensitive teenagers were compared to that of non-salt sensitive teenagers over five years.Results After 5 years, the repetition rate of salt sensitivity determined by intravenous saline loading is 92.7%. In teenagers with salt sensitivity on the baseline, both the systolic blood pressure increments and increment rates were much higher than non-salt sensitive teenagers (12.7±12.1 mmHg vs. 2.8±5.2 mmHg, P< 0.01; 12.2%± 12.0% vs. 2.5% ±4.4%, P< 0.001,respectively). There was a similar trend for diastolic blood pressure (8.4 ± 6.4 mmHg vs. 3.7 ± 6.4 mmHg, P = 0.052; 13.2% ±10.6 % vs. 6.8%± 10.1%, P = 0.053, respectively).Conclusions Salt sensitivity determined by intravenous saline loading showed good reproducibility. Blood pressure increments with age were much higher in salt-sensitive teenagers than non-salt sensitive teenagers, especially in terms of systolic blood pressure.  相似文献   

12.
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   

13.
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   

14.
Increasing maternal age is the only etiological factor unequivocally linked to Down's syndrome in humans. The occurrence rate of newborns with Down's syndrome is about 1/220 in women over 35 years old. However, the occurrence rate in embryos fertilized in vitro, of the elder woman is unclear. Using FISH we screened the number of chromosome 21 in preimplanted embryos of 5 elderly women (average age, 38.4 years) to study the feasibility and necessity of screening trisomy 21 in embryos in patients over 35 years old at the in vitro fertilization (IVF) center.  相似文献   

15.
Real-time three-dimensional echocardiography (RT3DE)is a new ultrasound technique that enables dynamic threedimensional visualization and quantification of the heart in real time. Investigation of feasibility and methodology of RT3DE in determining left ventricular (LV) and right ventricular (RV) volumes, RT3DE was performed in 35 normal adults using Philips SONOS 7500 system with a 2-4 MHz matrix array transducer. The 60°×60° "pyramid" volume database was obtained and analyzed on a TomTec echo workstation. Both LV and RV volumes were calculated with four 3DE methods (i.e. apical 2, 4, 8, and 16-plane) through manually tracing ventricular endocardial borders in end diastole and end systole. Stroke volumes were then calculated. LV volume was also measured by 2DE Simpson's rule using GE VIVID 7 ultrasound machine.  相似文献   

16.
A clinical guideline for the therapeutic interventions of integrative medicine may be defined as a written document which states a series of recommendations on therapeutic interventions of integrative medicine for a special disease or condition. The guideline may provide assistance to medical professionals in making clinical decisions aimed at improving the clinical outcome of patients and reducing the costs of medical care(~'4~. Recommendations issued by a guideline should be based on the best available evidence in both Western and Chinese medicine. For fulfilling this purpose, the development of clinical guidelines for therapeutic interventions in the field of integrative medicine should follow scientific principles and undergo a rigorous processes.  相似文献   

17.
Objective:To probe into the influence of changes of ovarian hormones on the pathogenesis of the specific sub-type premenstrual syndrome(PMS)and reveal partial microcosmic mechanisms of adverse flow of liver-qi.Methods:Estradiol(E2)and progesterone(P)levels in serum were determined at different phases of menstrual cycle by radioimmunoassay.Results:In the group of PMS with adverse flow of liver-qi.the secretive peak value Of E2 and P at the follicular phase significantly decreased,and the secretive peak value at the luteal phase did not come into being.Conclusions:Low E2 and P secretive peak at the follicular phase and absence of secretive peak at the luteal phase is one of the microcosmic mechanisms of PMS with adverse flow of liver-qi.One of the pathophysiologic mechanisms of specific sub-type PMS is probably the continuous low level of E2and P.  相似文献   

18.
Journal of Nanjing Medical University (English Edition) JNMU, sponsored by Nanjing Medical University, was established in 1987. It is a bimonthly comprehensive English medical journal published locally and abroad.Since 2007, Journal of Nanjing Medical University (English Edition )was granted Elsevier the full publishing and distribution rights worldwide for the Electronic Edition, excluding the People's Republic of China.  相似文献   

19.
目的:评价使用安心颗粒对急诊经皮冠状动脉介入术(PPCI)术后生活质量的影响.方法:将160例接受PPCI的急性ST段抬高型心肌梗死患者随机分为安心颗粒组(术前顿服安心颗粒8.8g,术后安心颗粒4.4 g/次,每日2次)和对照组(仅接受基础药物治疗).所有患者均服用阿司匹林、氯吡格雷和阿托伐他汀.分别在入院时、出院前1d、出院后180 d时,应用心肌梗死多维度量表(MIDAS)、中文版SF-36评价量表对患者生活质量评分.并观察术后30 d以内的出血并发症、血小板减少症发生情况.结果:入院时和出院前1d,两组患者的心肌梗死MIDAS、SF-36量表评分比较无差异(P>0.05);出院后180 d时,与对照组比较,安心颗粒组MIDAS、SF-36评分明显减低(P<0.05);组内与入院时比较,两组出院前1d、出院后180 d时,MIDAS、SF-36评分均降低(P<0.05).两组患者在随访期间均无大量出血、少量出血、重度和极重度血小板减少症发生,安心颗粒组有4例、对照组有7例发生不明显出血(P>0.05).两组发生轻度血小板减少症的患者数比较无差异(P>0.05).结论:PPCI使用安心颗粒,能改善急性ST段抬高型心肌梗死患者的生活质量,且不增加出血风险.  相似文献   

20.
Objective To measure Derpl and Blot5 allergen levels in asthmatics' homes in Hongkong.Methods Seventy houses were enrolled for a mite indoor environment study. Dust samples were obtained from two sites of each patients' house: bed and floor. Derpl and Blot5 levels were quantified by a two-site monoclonal antibody-based ELISA technique.Results The levels of Derpl allergens found in bed (geometric mean (GM) 3.43 μg/g of dust; 95%CI, 1.89-4.96 μg/g)and on the floor (GM 1.12 μg/g of dust; 95%CI, 0.71-1.53 μg/g) indicated significant differences (P=0.005). However, the levels of Blot5 allergens found in bed (GM 19.00 μg/g of dust; 95%CI, 0.89-38.90 μg/g) and on the floor (GM 6.14 μg/g of dust; 95%CI, 0.40-11.90 μg/g) showed no statistically significant difference. In addition, in regards to the exposure index for Derpl and Blot5 allergens found in bed and on the floor, 17.6% in bed and 8.6% on the floor had levels of Blot5 ≥ 10 μg/g of dust, higher than those obtained for Derp1 (7.2% and 0% in bed and on the floor respectively, P< 0.05); higher percentages in bed and on the floor (25.0% and 35.7%) were observed for levels of Blot5 =0 μg/g of dust as compared with Derpl in bed and on the floor (4.3% and 14.5% respectively, P< 0.05).Conclusions Derpl and Blot5 are the major allergens found in this regional study, Blot5 is a more potent allergen in Hongkong, probably reflecting the high level of exposure to Blomia tropicalis (Bt). Bt and Dermatophagoides pteronyssinus (Dp) allergens should be included for precise diagnosis and effective immuno-therapeutic treatment of mite allergy in Hongkong.  相似文献   

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