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1.
合成了5种具有不同分子量、不同亲疏水链段比例的两亲性嵌段共聚物——甲氧基聚乙二醇-b-聚己内酯(mPEG-b-PCL),并以其为表面活性剂,采用瞬时纳米沉淀(Flash Nano Precipitation,FNP)法制备出一系列包裹模型药物β-胡萝卜素的纳米粒子。通过改变两亲性共聚物的结构、分子量、浓度及溶剂体积比(V(H2O):V(THF)),成功实现了对纳米粒子尺寸的调控。实验结果表明:聚合物亲水链段分子量比例增大,则纳米粒子尺寸减小;当亲水链段分子量比例相同时,聚合物分子量越大,则纳米粒子尺寸越小;当聚合物质量浓度较高(10.0 g/L)时,制备的纳米粒子粒径分布较窄,粒子性能较稳定。  相似文献   

2.
纳米金催化剂由于具有条件温和、专一性强等特点而广泛用于多相绿色催化过程中,但它易团聚、难分离、难回收的特点使其应用受到限制。受到聚多巴胺(PDA)具有黏附性和还原性的启发,本文利用PDA原位还原四氯金酸制备了一种多层负载型SiO2@PDA@Au催化剂颗粒。PDA可以紧密且连续地包覆在SiO2表面,并可实现金纳米颗粒的原位还原和负载;金含量随着PDA层厚的增加而增加,金颗粒粒径较均一、无团聚,粒径约为30 nm;当Au负载量(质量分数)为1.59%时,对亚甲基蓝(MB)的还原反应的催化活性最好(表观反应速率常数Kapp=1.613 4 min-1),且具有良好的循环稳定性。  相似文献   

3.
以铁蛋白(FTH1)为基础,围绕系统纳米粒子的肿瘤靶向性、高载性和纳米粒子间的靶向性识别等关键点,构建了具有"靶向/聚集"特性的系统纳米粒子,并对其关键特性进行了详细研究。实验结果表明, "靶向纳米粒子" RGD/HSA-FTH1-biotin不仅具备靶向整合素αvβ3的特性,还能够高载生物素(Biotin)分子(纳米粒子与载有的生物素的物质的量之比为40);同时"聚集纳米粒子"mSA-FTH1/FTH1能特异性识别生物素并与之结合。这些研究显示了"靶向/聚集"纳米粒子的成功构建为该系统纳米粒子策略在微小肿瘤的诊断治疗方面的应用打下了重要基础。  相似文献   

4.
目的 通过检测给药后血浆中白藜芦醇的量,比较纳米级白藜芦醇和白藜芦醇β-环糊精包合物生物利用度的差异。方法 采用高效液相色谱法,测定给药后不同时间段大鼠血浆中白藜芦醇的质量浓度,使用3p97软件进行药动学参数模拟。结果 纳米级白藜芦醇药动学参数:AUC=315.89 μg?min/mL,tmax=21.71 min,Cmax=3.23 μg/mL;白藜芦醇β-环糊精包物药动学参数:AUC=185.83 μg?min/mL,tmax=40.44 min,Cmax=1.69 μg/mL。结论 纳米级白藜芦醇达峰时间短,且生物利用度明显高于白藜芦醇β-环糊精包合物。  相似文献   

5.
提出了锂离子电池中苯衍生物氧化还原穿梭分子的一种稳定性模型。此模型同时考虑了电池中氧化还原穿梭分子的成键/断键反应和还原反应,在100%穿梭分子保护充电次数的实验值(用对数表示)和组合反应指数(Eb(ER)+0.3Eb(Li))之间得到了很好的线性关系,其中Eb(ER)和Eb(Li)分别是氧化还原穿梭分子阳离子在模型反应中与乙基(ER)、Li原子团中单个Li原子的结合能。  相似文献   

6.
结合耗散粒子动力学模拟和时域有限差分方法,研究了A(BC)n多嵌段共聚物和纳米粒子共混体系的自组装行为及其光学性能,分析了纳米粒子体积分数和嵌段间相互作用强度对自组装形貌及其光学性能的影响。结果表明,A(BC)n多嵌段共聚物/纳米粒子共混体系可形成有机/无机杂化的多级结构,改变纳米粒子的体积分数和嵌段间相互作用强度可以调控纳米粒子的分布及其相应的多级结构。不同尺度的结构对不同频率光的反射作用有明显区别,而纳米粒子的加入显著增大了反射峰的强度和宽度。改变纳米粒子的分布可调控反射峰的强度和宽度。  相似文献   

7.
目的 研究载天冬酰胺酶(asparaginase, AAS)自组装透明质酸-聚乙二醇(hyaluronic acid-graft-poly ethylene glycol, HA-g-PEG)/羟丙基-β-环糊精(hydroxypropyl-beta-cyclodextrin, HPCD)纳米微球(self-assembly HA-g-PEG/HPCD hollow nanospheres loaded with AAS, AHHPs)在雄性SD大鼠体内的药代动力学和生物等效性。方法 采用自组装方法制备AHHPs, 考察AHHPs的透射电镜、粒径、Zeta电位、包封率,分别测定大鼠静脉注射给予AHHPs和游离AAS后,不同时间点大鼠血浆样品中AAS的活性。采用DAS 2.1.1软件计算药动学参数,对AHHPs和游离AAS进行生物等效性评价。结果 制得的AHHPs平均粒径为(367.43±2.72) nm,Zeta电位为(-15.70±1.25)mV,平均包封率为(66.03 ± 3.81)%。AHHPs和游离AAS大鼠静脉注射给药后,AHHPs和游离AAS的主要药动学参数:药时曲线下面积AUC(0-48 h)分别为(162.06±4.01) U/mL·h和(46.38±1.98) U/mL·h,AUC(0-∞)分别为(203.74±12.91) U/mL·h和(51.44 ±3.01) U/mL·h,平均驻留时间MRT(0-72 h)分别为(4.35±0.06) h和(1.76±0.06) h, MRT(0-∞)分别为(7.53±1.05) h和(2.44±0.29) h,药峰浓度Cmax分别为(30.37±0.43) U/mL和(26.06±0.88) U/mL,达峰时间Tmax分别为(0.75±0.00) h和(0.08±0.00) h。与游离AAS比较,AHHPs的AUC(0-48 h)AUC(0-∞)MRT(0-72 h)MRT(0-∞)CmaxTmax分别提高了3.5倍、4.0倍、2.5倍、3.1倍、1.2倍和9.4倍。AUC(0-48 h)AUC(0-∞)Cmax的90%置信区间分别为72.6%~74.0%、72.3%~73.7%、94.7%~96.3%。结论 AHHPs延长了AAS在大鼠体内的生物半衰期,提高了AAS在大鼠体内的生物利用度,且AHHPs与游离AAS不具有生物等效性。  相似文献   

8.
以葡萄糖基-β-环糊精(Glu-β-CD)作为手性选择剂,N-丁基-N-甲基吡咯烷十二烷基硫酸盐([C4MP][C12SO4])离子液体表面活性剂形成胶束作为准固定相,在低pH条件下构建胶束电动毛细管色谱(MEKC)用于4种酸性药物萘普生、华法令、酮洛芬和布洛芬的手性拆分。在相同条件下,与基于传统表面活性剂十二烷基硫酸钠(SDS)的MEKC体系相比,[C4MP][C12SO4]体系能大大提高药物的分离度,且使得一些原本不能拆分的药物得到部分分离。本研究考察了有机溶剂种类和比例、运行缓冲溶液浓度与pH、手性选择剂浓度、离子液体表面活性剂浓度、运行电压等影响手性拆分的因素,探索了离子液体表面活性剂在MEKC体系中的分离潜能,为手性药物的分离提供参考。  相似文献   

9.
地塞米松纳米立方液晶眼用制剂家兔房水药代动力学   总被引:1,自引:0,他引:1  
目的: 以地塞米松(DEX)为模型药物制备眼用纳米立方液晶眼用制剂,并对其家兔房水药代动力学进行了考察。方法: 采用高压均质法制备DEX纳米立方液晶,激光粒度测定仪测定粒径,低温透射电镜观察粒子的微观形态;Draize评分法评价制剂的眼部刺激性;采用微渗析法评价家兔的房水药代动力学。结果: DEX纳米立方液晶平均粒径约200 nm,低温透射电镜可见其清晰的立方体结构。Draize评分结果显示,该制剂对家兔眼部无刺激性。房水药代动力学结果显示,DEX纳米立方液晶制剂组AUC0→240,c max 均显著高于市售溶液剂组,且处方1(F1,10%脂质含量)和处方2(F2,20%脂质含量)的AUC0→240分别是市售溶液剂的1.8倍和2.9倍(P<0.05)。结论: DEX纳米立方液晶眼用制剂能够显著提高房水药物浓度,改善药物在眼部组织的生物利用度。  相似文献   

10.
建立检查盐酸度洛西汀中左旋异构体的HPLC手性流动相添加剂法,为本品的质量控制提供有效的分析方法。通过优化手性添加剂环糊精种类和浓度、流动相pH和甲醇比例,确定实验条件为Diamonsil C18柱(150 mm×4.6 mm,5 μm),10 mg/mL磺丁基醚-β-环糊精(SBE-β-CD)溶液(磷酸调pH至2.5)-甲醇(73∶27)为流动相,流速为1.0 mL/ min,柱温40 ℃,检测波长为230 nm。在选定的色谱条件下盐酸度洛西汀对映体之间的分离度为2.3。左旋异构体在1.0~50 μg/mL范围内,峰面积与浓度线性关系良好(r=0.999 9),左旋异构体平均回收率为100.8 %(RSD=1.0 %),定量限为0.02 μg。本研究建立的方法简便、准确、专属性强,可用于盐酸度洛西汀中左旋异构体的检查。  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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