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1.
合成了一类具有高水合常数(q)的钆类造影剂,该类配合物由金属钆与含有2个氮氧化基团和4个羧酸基团的有机配体组成,具有高水合常数的特点。通过核磁氢谱、碳谱以及高分辨质谱对配体及配合物的结构进行了表征。通过荧光寿命分析检测配合物的q值在3左右。该类配合物的纵向弛豫率(r1)为8.5~10.1 (mM)-1·s-1,约为商用造影剂二乙三胺五乙酸合钆(Gd-DTPA)的3倍。细胞实验证实该类造影剂具有很低的细胞毒性,这在临床应用中是非常关键的。该类配合物具有合成简便、弛豫率高以及毒性低等特点,为制备更低成本、更高性能的造影剂打下基础。  相似文献   

2.
以3-叔丁基-5-甲氧基水杨醛和邻取代苯胺为原料,合成了两个水杨醛亚胺配体(1,2)及相应的锆络合物(3,4)。用质谱(MS)、核磁共振氢谱(1H-NMR)和核磁共振碳谱(13C-NMR)等方法表征了配体及络合物的结构,采用流变仪、差示扫描量热仪(DSC)对聚合物进行了分析。研究了乙烯压力、聚合温度、时间、溶剂、铝锆物质的量之比(nAlnZr)等对络合物催化性能和聚乙烯分子量的影响。结果表明,在甲基铝氧烷(MAO)的助催化下,锆络合物在甲苯中对乙烯聚合具有较好的催化活性,所得聚合物为超高分子量聚乙烯。在30℃、0.9 MPa下,络合物4在正己烷中的催化活性达到60.2 kg/(mmol·h),聚乙烯的黏均分子量最高可达6.6×106,分子量分布为2.4,聚合过程具有良好的可控性。  相似文献   

3.
苏媚  刘涛 《医学教育探索》2015,28(3):294-301
以二硫化二异丙基黄原酸酯(DIP)为链转移剂前驱体,偶氮二异丁腈(AIBN)为引发剂,采用可逆加成断裂链转移(RAFT)溶液聚合合成了低数均分子量(Mn < 1.0×104)和窄分子量分布(Mw/Mn < 1.5)的聚醋酸乙烯酯(PVAc)。用核磁共振(1H-NMR)、凝胶渗透色谱(GPC)表征了PVAc的结构与分子量。结果表明:溶剂类型、引发剂浓度、链转移剂浓度和聚合反应温度对醋酸乙烯酯RAFT自由基聚合的转化率及可控/"活性"特征有重要影响。在相同条件下,溶剂极性较大的四氢呋喃对PVAc的分子量及其分布的可控性要优于极性较小的苯溶剂;聚合速率及产物分子量分布均随着引发剂浓度的增加而增大;增大DIP的浓度,聚合速率降低,聚合过程的可控性变好;温度升高聚合速率加快,分子量分布指数(PDI)增大。  相似文献   

4.
通过将三(2-氨基乙基)胺(TREN)、6-羧基荧光素与溴乙酸苄酯结合而合成出多胺多羧型配体,并赋予化合物荧光成像的功能。进一步与顺磁性的六水合氯化钆(Ⅲ)反应获得兼具核磁共振成像(Magnetic Resonance Imaging,MRI)和光学成像功能的双模式核磁共振成像造影剂。通过核磁氢谱、碳谱、高分辨质谱和ICP-AES表征了配体和金属配合物的结构。研究结果表明,该配合物的纵向弛豫率(r1)为3.46 mM-1·s-1,与小分子型商用造影剂如马根维显®(Gd-DTPA)接近。该配合物同时拥有66%的荧光量子产率,在紫外光照射下显示明亮的绿色荧光,为以后进行生物体内研究打下坚实基础。  相似文献   

5.
研究了3个在苯胺基邻位含有不同位阻效应的双(水杨醛亚胺)镍配合物C1~C3的合成及其结构的分析与表征。在助催化剂甲基铝氧烷(MAO)作用下,以C3为主催化剂,考察了Al与Ni物质的量之比(nAl/nNi)、催化剂用量、反应温度、压力、甲基丙烯酸甲酯(MMA)浓度、时间等对乙烯与甲基丙烯酸甲酯共聚的影响,得到最佳聚合条件为:nAl/nNi为150,温度25℃,压力2 MPa,反应时间2 h。在此条件下评价了C1C2C3催化剂结构对聚合反应的影响,发现在苯胺基邻位的取代基位阻较小时,催化活性较好,但所得聚合物分子量较低,并对共聚物结构进行了1H-NMR、13C-NMR、FT-IR等分析和表征。  相似文献   

6.
PSGL-1缺失导致MDSCs上调   总被引:1,自引:1,他引:0       下载免费PDF全文
目的 P-选凝素糖蛋白配体1(P-selectin glycoprotein ligand 1, PSGL-1)主要特异性表达在白细胞上, 我们的研究PSGL-1缺失在小鼠体内脾脏、骨髓中MDSCs的变化。方法 利用我们实验室现有的PSGL-1-/-小鼠进行试验, 经过鉴定后, PSGL-1-/-后代小鼠;利用流式细胞术检测C57和PSGL-1-/-小鼠脾脏、骨髓中Gr-1和CD11b阳性细胞的变化。结果 与对照组C57小鼠相比, PSGL-1-/-基因工程小鼠MDSCs在脾脏、骨髓中显著上调(P<0.001), 结论 PSGL-1的缺失导致小鼠脾脏、骨髓中MDSCs升高。  相似文献   

7.
以蛇床子素为先导化合物,合成了6个目标化合物(1-5 、Ⅵ7),其结构经MS及1H NMR确证;通过抗人脐静脉内皮细胞(HUVEC)体外增殖的实验,测定了目标物抑制微管蛋白聚合的活性。结果表明,所合成的化合物多数具有一定的抑制微管蛋白聚合的作用,其中化合物Ⅵ7 的活性最强,值得进一步深入研究。  相似文献   

8.
为有效控制合成润滑油基础油的性能,以tBuNC(Me)2η5-C5H5)ZrCl2/MAO催化剂催化1-癸烯齐聚,建立了排除扩散影响的动力学模型,考察温度和单体质量浓度对聚合速率的影响,以及温度对相对分子质量及其分布的影响。结果表明:聚合速率随着反应温度的升高而升高,计算得到表观活化能为4.86 kJ/mol,聚合反应速率对单体质量浓度呈1.47级依赖;随着温度的升高产物分子质量减小,相对分子质量分布变宽,选择最佳聚合温度为80℃;产物相对分子质量分布接近2,符合茂金属催化剂作为单一活性中心的动力学模型假设。  相似文献   

9.
钛改性硅胶负载Cr-Mo复合乙烯聚合Phillips催化剂   总被引:1,自引:1,他引:0  
Phillips催化剂(CrOx/SiO2)是一种重要的高密度聚乙烯工业催化剂。以钛改性硅胶作载体,制备钛改性铬钼复合Phillips催化剂(CrMo/TiSi),并考察其对乙烯聚合的催化性能。对比铬钼复合催化剂(CrMo/Si),运用程序升温还原(TPR)、X射线光电子能谱(XPS)和密度泛函理论(DFT)计算等方法考察钛改性对铬钼双金属相互作用的影响。乙烯聚合活性和产品性能表征结果表明,钛改性后催化剂活性提高,聚乙烯分子量增大,分子量分布变宽。乙烯/1-己烯共聚产物的高温凝胶渗透色谱、高温13C-NMR、升温淋洗分级和连续自成核退火热分级(TREF+SSA)结果表明,钛改性复合催化剂有利于1-己烯插入,产物中高分子量部分支链含量减少。  相似文献   

10.
首先,通过苯甲醛(BA)改性的聚砜(BA-PSF)与氨基吡嗪(AP)发生席夫碱反应,制得了侧链含氨基吡嗪型双齿席夫碱配基(APSB)的功能化聚砜APSB-PSF。使用核磁共振氢谱(1H-NMR)、红外光谱(FT-IR)表征其化学结构。然后,以APSB-PSF为大分子配体,邻菲罗啉(Phen)为第二配体,使它们与Tb(Ⅲ)离子进行配位螯合反应,分别制备了二元高分子-稀土配合物Tb(Ⅲ)-(APSB)3-PSF与三元配合物(Phen)1-Tb(Ⅲ)-(APSB)3-PSF,研究了配合物Tb(Ⅲ)-(APSB)3-PSF和(Phen)1-Tb(Ⅲ)-(APSB)3-PSF的荧光发射特性与发光机理。实验结果表明,大分子配体APSB-PSF不但能够强烈地吸收紫外光,且其本身荧光强度很高;当APSB-PSF与Tb(Ⅲ)离子配位生成新的二元配合物后,其自身的吸光强度基本不变,但荧光强度却大为削弱,即能量发生了转移,该配合物同时发射出Tb(Ⅲ)离子的特征荧光,且由于接受了APSB-PSF转移的能量使其发光强度大大增强,即APSB-PSF对Tb(Ⅲ)离子发生了敏化作用。而配体APSB-PSF的三线态与Eu(Ⅲ)离子的共振能级不匹配,使APSB-PSF与Eu(Ⅲ)离子的配合物几乎不发射荧光。三元配合物不仅发射出Tb(Ⅲ)离子的特征荧光,且其发光强度高于二元配合物。  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 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.
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   

19.
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   

20.
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   

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