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1.
采用溶液聚合的方法合成聚马来酸酐,考察不同聚合条件对聚马来酸酐产率的影响。将所合成的聚马来酸酐与十八醇、十六醇和十四醇进行酯化反应合成了三种两亲性的大分子表面改性荆聚马来酸酐十八醇酯(PMAO)、聚马来酸酐十六醇酯(PMAH)和聚马来酸酐十四醇酯(PMAT)。对这三种聚马来酸酐高级醇酯/聚乙烯共混体系的表面亲水性进行了研究,采用全反射红外光谱对聚马来酸酐高级醇酯共混体系薄膜进行表征,发现聚马来酸酐高级醇酯可以在聚乙烯薄膜表面富集,接触角测量表明聚马来酸酐高级醇酯的加入可以有效降低聚乙烯薄膜的水接触角。  相似文献   

2.
聚酸酐管桥接修复神经缺损和聚酸酐管降解时相研究   总被引:2,自引:0,他引:2  
目的 研究聚酸酐管桥接神经缺损的再生和聚酸酐管生物降解时相。方法 96只SD大鼠于坐骨神经股中部切断,缺损间隙10mm,用聚酸酐管套接缺损神经两端形成神经再生室。分别于术后第3、7、14、21、28、35、42和63d时取再生室中组织,将其切成长1mm段的10个组织块,各段分别制备切片。用透射电镜观察,并记录各时间段聚酸酐管的外观变化。结果 聚酸酐管神经再生室中的神经再生过程可分为:术后3~7d的液体充盈和细胞聚集期;7~28d神经生长期;28~63d神经纤维成熟期。聚酸酐管周围无结缔组织疤痕形成。术后3~28d聚酸酐管出现裂纹,裂隙并逐渐增大呈网状;28~63d聚酸酐管逐渐降解被吸收;术后63d完全降解吸收,再生神经表面光滑完整。结论 再生室形成的微环境有利于缺损神经的再生和修复;聚酸酐管是生物降解材料,经过63d完全被机体降解吸收,再生神经周围无疤痕和异物形成。  相似文献   

3.
聚酸酐一类新型合成生物可降解高分子材料,由于具有良好的生物相容性、表面融蚀降解性以及降解速度可调等优良性能,本文综述了聚酸酐的结构性质、发展概况、合成研究进展及医药学上的应用进行了总结,并对其研究开发前景提出展望.  相似文献   

4.
采用甲基丙烯酸酐(或甲基丙烯酰氯)与无毒二元酸反应合成了混合酸酐:甲基丙烯酸酐化癸二酸(MSA)和甲基丙烯酸酐化的1,6-二(对羧基苯氧基)己烷(MCPH)。并用1H-NMR、IR表征其结构,结果表明:直接酸酐法制得的MSA,酰氯法制得的MCPH符合聚酸酐单体的结构特征。MSA和MCPH可以在紫外光照射下生成高度交联的聚酸酐网络,通过改变MSA与MCPH的共聚比例,可以将该网络的降解时间控制在4~70d之间。  相似文献   

5.
本文以L-谷氨酸为原料,经γ-羧基的苄基保护.与光气-甲苯液反应制备谷氨酸苄酯的N-羧酸酐(NCA).均聚得聚谷氨酸节酯(PBLG),然后由2-氨基乙醇胺解得水溶性的聚[N-(2-羟乙基)-L-谷酰胺](PHEG),并对其进行了UV、IR、分子量、羟基含量的表征。  相似文献   

6.
酸酐—酰亚胺共聚物的合成   总被引:1,自引:0,他引:1  
熔融缩聚法合成了酸酐-酰亚胺共聚物并研究了基性质。酸酐-酰亚胺共聚物是一种新型的生物可降解高分子材料,它是在以癸二酸(SA)和1,3-双(对羧基苯氧基)己烷(CPH)为单体的聚酸酐骨架中插入含有酪氨酸的单体(TMA-Tyr)而形成的。酪氨酸作为免疫佐剂可显著提高机体对吸收抗原的免疫应答,从而使酸酐-酰亚胺共聚物有可能成为一种极佳的免疫抗原载体。  相似文献   

7.
目的:以L-苯丙氨酸和L-天冬氨酸为原料,合成得到不同相对分子质量的聚苯丙氨酸-聚天冬氨酸两亲性氨基酸嵌段共聚物。方法以L-苯丙氨酸、L-天冬氨酸为原料,合成N-羧基-L-苯丙氨酸-环内酸酐、N-羧基-L-天冬氨酸苄酯-环内酸酐,采用开环聚合反应,得到目标化合物聚苯丙氨酸-聚天冬氨酸嵌段共聚物;利用芘荧光探针法对共聚物临界胶束浓度进行了测定。结果合成得到了疏水链段相对分子质量为500、2000、4000的两亲性嵌段共聚物,结构经氢核磁和红外光谱法确认;随着共聚物聚苯丙氨酸与聚天冬氨酸比例不同得到的聚合物的临界胶束浓度也发生了变化。结论疏水性链段聚苯丙氨酸链越长聚合物的临界胶束浓度越小。这为进一步研究不同性质的聚合物对药物纳米粒的稳定作用奠定了基础。  相似文献   

8.
【目的】采用嵌段共聚法将聚乙二醇(PEG)引入聚谷氨酸苄酯(PBLG)得到聚谷氨酸苄酯-聚乙二醇-聚谷氨酸苄酯两亲嵌段共聚物(PBLG-PEG-PBLG,缩写为GEG),研究引入PEG对GEG膜表面细菌黏附性的影响。【方法】以端氨基聚乙二醇引发谷氨酸苄酯N-羧酸酐开环聚合得到GEG,用凝胶渗透色谱、红外光谱、核磁共振谱和表面接触角对共聚物的结构和物理化学性质进行表征;将聚合物膜悬浮在金黄色葡萄球菌的菌悬液孵育24h.用扫描电镜观察细菌在聚合物表面黏附的情况。【结果】端氨基聚乙二醇能引发谷氨酸苄酯N-羧酸酐开环聚合形成嵌段共聚物;引入PEG不同程度地降低了材料表面的接触角.减少了细菌在共聚物表面的黏附:PEG嵌段在共聚物中的含量越高,材料表面接触角越小,黏附的细菌越少。【结论】将PEG引入PBLG能在某种程度上抑制细菌黏附。这种嵌段共聚物在组织工程和药学领域有潜在应用前景。  相似文献   

9.
 【目的】采用嵌段共聚法将聚乙二醇(PEG)引入聚谷氨酸苄酯(PBLG)得到聚谷氨酸苄酯-聚乙二醇-聚谷氨酸苄酯两亲嵌段共聚物(PBLG-PEG-PBLG,缩写为GEG),研究引入PEG对GEG膜表面细菌黏附性的影响。【方法】以端氨基聚乙二醇引发谷氨酸苄酯N-羧酸酐开环聚合得到GEG,用凝胶渗透色谱、红外光谱、核磁共振谱和表面接触角对共聚物的结构和物理化学性质进行表征;将聚合物膜悬浮在金黄色葡萄球菌的菌悬液孵育24h.用扫描电镜观察细菌在聚合物表面黏附的情况。【结果】端氨基聚乙二醇能引发谷氨酸苄酯N-羧酸酐开环聚合形成嵌段共聚物;引入PEG不同程度地降低了材料表面的接触角.减少了细菌在共聚物表面的黏附:PEG嵌段在共聚物中的含量越高,材料表面接触角越小,黏附的细菌越少。【结论】将PEG引入PBLG能在某种程度上抑制细菌黏附。这种嵌段共聚物在组织工程和药学领域有潜在应用前景。  相似文献   

10.
通过力学性能、热性能以及扫描电镜等方法研究了聚醚多元醇对环氧树脂酸酐体系的增韧效果。结果表明:聚醚多元醇在环氧固化过程中分相析出,呈现出较好的增韧效果;在环氧酸酐体系中,大分子量聚醚多元醇的增韧效果不如小分子量的;而由环氧乙烷封端的聚醚多元醇,由于含有与环氧树脂相容的聚环氧乙烷(PEO)链段,分散相与环氧母体间能够形成良好的界面作用,也体现出良好的增韧效果。  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.
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   

14.
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   

15.
Objective:To investigate the influences of urapidil and nicardipine on rabbit sinus function,atrio-ventricular node function and hemodynamics.Methods:Thirty-two Angora's rabbits were selected and randomly divided into four groups.U1 group:urapidil 0.25 mg/kg;U2 group:urapidil 0.5 mg/kg;N1 group:nicardipine 10 μg/kg;N2 group:nicardipine 20 μg/kg.All these medicine were administrated within 30 seconds.Measurements were taken before and after the administration of urapidil or nicardipine for the following data:mean blood pressure(MAP),heart rate(HR),sino-atrial conduction time(SACT),maximal sinoatrial recovery time(SNRTmax)corrected sinus node recovery time(CSNRT),index of sinus node recovery time(SNRTI),Wenckebach A-V conduction frequency (WB),and P-R interval.Results:Significant MAP and HR changes were identified in all of the four groups before and after administration of both urapidil and nicardipine.No significant changes could be found in the rest of the parameters.Intergroup analysis showed that SACT and CSNRT of N1 and N2 groups were shorter than those of the U2 group(P<0.01);the MAP decreased(P<0.01)and the HR increased drastically(P<0.01).Conclusions:Neither urapidil(0.25 mg/kg,0.5 mg/kg)nor nicardipine(10μg/kg,20μg/kg)has any significant influence on rabbit sinus function or rabbit atrio-ventricular node function.Nicardipine could be a better choice than urapidil for parafunctional sinus node patients.  相似文献   

16.
Objective:To investigate the gene expression of osteoprotegerin(OPG) and osteoclast differentiation factor(ODF) in the bone tissue of patients with hip fracture due to osteoporosis. Methods:OPGmRNA and ODFmRNA in the bone tissue in 50 cases of osteoporosis sufferers(over 50 years old) with hip fracture(Observer Group) and 30 cases of hip facture sufferers with no osteoporosis(Control group) were analyzed with the Semi-Quantitative RT-PCR method. Results:The mRNA expressed of ODF, OPG were both high in the patients with hip fracture. In the control group, the expression of OPG mRNA was observed, while the expression of ODF mRNA was very slight. Conclusion:Aged patients contained all signals including OPG, ODF that are essential for inducing osteoclastogenesis and promoting bone resorption.  相似文献   

17.
Objective:To investigate the clinical features, pathological characteristics and immunophenotype of solid-pseudopapillary tumor of the pancreas(SPTP). Methods:Nine surgically treated cases of SPTP were retrospectively reviewed. Hematoxylin and Eosin(HE) staining and immunohistochemical staining were used to analyze all cases, and the general clinical data was collected. Results:Six patients were asymptomatic except for a palpable mass. Two patients complained of vague-epigastric pain. One patient appeared jaundice. The tumor was encapsulated and solid tissues alternately with cystic tissues. Histologically, the histological structure of solid portion was pseudopapillary with a fibrovascular core. Tumor cells were uniform and medium-sized which were arranged in sheets ets or nests or pseudopapillary patterns. Immunohistochemical studies demonstrated that SPTP proved positive in vimentin(9/9 cases), AAT(9/9 cases), NSE(9/9 cases), ACT(7/9 cases), CK20(2/9 cases), CgA(1/9 cases), S-100(3/gcases), PR(4/gcases), Syn(3/9 cases) and CD56(5/9cases), negative in CEA and ER. Conclusion:SPTP is a tumor predominantly occurring in young women frequently without special symptoms. This tumor has various characteristical histological patterns with different immunophenotype.  相似文献   

18.
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   

19.
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   

20.
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   

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