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1.
采用硬模板法,以间位碳硼烷为硼源、3-氨基苯基乙炔树脂为氮源和碳源、介孔二氧化硅(SBA-15)为硬模板,成功制备了氮硼共掺杂的有序介孔碳材料(NBC)。采用X射线衍射(XRD)、N2吸附-脱附测试、透射电镜(TEM)和X射线光电子能谱(XPS)研究了前驱体中B与N的物质的量之比(nB/nN)对NBC结构的影响。采用紫外-可见分光光度计(UV-Vis)研究了NBC对甲基橙染料的吸附性能。结果表明:NBC具有二维六方的有序结构,孔径可调且分布集中在3~6 nm。其中,NBC-1.0样品(nB/nN=1.0)具有最高的比表面积(1 560 m2/g)、最大比孔容(1.92 cm3/g)及高度有序性。相比于传统的活性炭吸附剂(吸附量61 mg/g),NBC-1.0可以实现对甲基橙染料的快速、有效吸附,其吸附量可达214 mg/g。  相似文献   

2.
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   

3.
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   

4.
以聚乙二醇单甲醚(mPEG)为原料,制备大分子引发剂mPEG-Gn-OH2nn=1,2,3,4),以异辛酸亚锡为催化剂,引发L-丙交酯开环聚合,通过控制丙交酯和大分子引发剂的投料比,合成1~4代线性-树枝状两亲聚合物。基于聚合物自组装特性,通过透析法制备聚合物胶束,采用核磁氢谱、渗透凝胶色谱对聚合物结构进行表征,使用动态激光光散射技术、电子扫描显微镜和透射电镜对其聚集体进行观测。研究表明,胶束流体力学直径主要受代数影响,并随PEG链段增加而增大,胶束粒径为200~300 nm。胶束形状反映聚合物分子中亲水、亲油比,当聚合物分子中亲水链段EO体积分数φEO<0.35时,线性-树枝状两亲聚合物才能形成空心胶束。  相似文献   

5.
采用无规聚醚多元醇对木质素进行了化学改性,在木质素分子结构中引入柔性多元醇分子链,通过热压法制备了聚醚多元醇改性木质素的高分子薄膜。采用傅里叶变换红外光谱(FT-IR)、热重(TG)和动态热机械分析(DMA)等手段表征了聚醚多元醇改性木质素的结构和热力学性能。考察了木质素的质量分数、无规聚醚多元醇的数均分子量以及异氰酸官能团与体系总羟基的物质的量之比(nNCO:nOH)对木质素薄膜力学性能的影响。结果表明:聚醚多元醇通过氨基甲酸酯化学键接到木质素分子上,改性之后其热稳定性明显提高,玻璃化转变温度为72℃;当nNCO:nOH为1.5:1,无规聚醚多元醇的数均分子量为1 500以及木质素质量含量为33%时,薄膜的综合力学性能最佳。  相似文献   

6.
n阶(n≥6)简单连通无向图G的谱半径记为ρG)。依G的谱半径从大到小进行了排序,得到如下结果:ρKn)>ρKnK2)>ρKnP3)>ρKn-2K2)>ρKnK1,3)>ρKn-C3)>ρKnP4)>ρKnP3K2)。  相似文献   

7.
采用固定床反应器,研究了复合载体镍基催化剂上的CO甲烷化反应。在温度为250~440℃,压力为0.1~2.5 MPa,原料气配比(nH2/nCO)为1.0~4.5的情况下,考察了操作条件对复合载体镍基催化剂甲烷化反应的影响。实验结果表明:CO转化率、CH4的选择性均随着反应温度、反应压力的升高而增加;当反应温度达到340℃时,CO转化率最高;当nH2/nCO=3.0时,具有较高的CO转化率和CH4的选择性。通过正交法设计实验,测定了甲烷化反应动力学数据。以双曲型动力学方程建立了以各组分逸度表示的CH4和CO2反应动力学模型,并用最大继承法对参数进行估值,获得动力学参数。残差分析及统计检验表明动力学模型是适宜的。  相似文献   

8.
以过硫酸钾(K2S2O8)为氧化剂、γ-氨丙基三乙氧基硅烷(KH550)为偶联剂、氨基硅油乳液(ASOE)为接枝改性液,对聚砜(PSF)膜进行疏水改性研究。考察了KH550 溶液的质量分数、处理温度、处理时间和ASOE的接枝时间、接枝温度对膜疏水性的影响。采用全反射-傅里叶红外光谱(ATR-FTIR)对接枝前后的膜进行表征,采用扫描电子显微镜(SEM)观察改性前后膜的表面形貌变化。结果表明,疏水性基团被接枝到PSF膜表面,改性后PSF膜的水接触角从87°提高到116°,疏水性得到提高。  相似文献   

9.
首先,将偶联剂γ-巯丙基三甲氧基硅烷(MPMS)上的巯基(-SH)键合在微米级硅胶(SiO2)微粒表面,得到了改性微粒MPMS-SiO2。在非水溶剂N,N-二甲基甲酰胺(DMF)中,使溶液中的过氧化苯甲酰(BPO)与改性微粒MPMS-SiO2表面的巯基构成表面引发体系(-SH/BPO),于非水介质中在硅胶微粒表面实现了甲基丙烯酸羟乙酯(HEMA)的接枝聚合,成功制备出接枝微粒PHEMA-SiO2,接枝度高达28 g/100 g。采用红外光谱(FT-IR)、热重分析(TG)及扫描电子显微镜(SEM)等手段对PHEMA-SiO2进行了表征,研究了主要因素对HEMA表面引发接枝聚合的影响规律。在此基础上探索研究了PHEMA-SiO2对槲皮素(Quercetin)的氢键吸附作用。研究结果表明:-SH/BPO引发体系可以顺利地引发HEMA在非水介质中的接枝聚合,适宜的温度为65℃,适宜的BPO用量为单体质量的1.0%。PHEMA-SiO2与槲皮素分子之间会产生多位点普通氢键与π型氢键两种氢键相互作用,使PHEMA-SiO2对槲皮素具有强吸附能力。溶剂分子对槲皮素的竞争吸附以及温度的升高均可使槲皮素在极性溶剂或质子性溶剂中吸附容量下降。  相似文献   

10.
多硫化氢(hydrogen polysulfides, H2Sn, n ≥ 2)作为硫化氢(hydrogen sulfide, H2S)所衍生的活性硫物质,在生理调节及信号转导过程中扮演着不可或缺的角色。H2Sn与H2S互为氧化还原对,一般经氧化或酶促作用从H2S转化生成,通过调节蛋白质相互作用及改变酶活力等方式发挥其生理作用。随着研究的深入,发现一些原本被认为是H2S发挥的生理学功能可能是由H2Sn所发挥的,并且H2Sn具有更高的蛋白质巯基化效率。因此,实时检测生物体内的H2Sn对于研究其生理活性及与H2S之间的联系具有十分重要的意义。传统的质谱光谱等检测方法需要破碎组织细胞,不适用于生物体内的实时检测。而荧光探针因其具有高灵敏度及特异性,同时生物毒性低常被选作H2Sn原位实时检测工具。本文概述了H2Sn的生理调节活性,着重基于响应机制的反应类型的介绍H2Sn检测荧光探针的设计策略、荧光性能、检测特点及生物成像应用等方面,并对这一领域所面临的挑战与发展进行了展望。  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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