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1.
目的:研究异烟肼在电化学预处理玻碳电极上的电化学响应。方法:采用三电极系统,以电化学预处理玻碳电极为工作电极,饱和甘汞电极为参比电极,铂电极为对电极,用循环伏安法研究异烟肼的电化学行为。结果:异烟肼在预处理的玻碳电极上产生两个不可逆的还原峰,电位分别为-0.80V和-0.90V,其过程是一个表面吸附过程。发现在-0.90V出现的还原峰的峰电流与异烟肼的浓度在1.2×10-10~1.3×10-3mol/L的范围内成线性关系。异烟肼的检测限低达1.2×10-11mol/L(ta=40 s,S/N=3),平行8次测定1.2×10-6mol/L异烟肼的相对标准偏差为4.5%。在B ritton-Rob inson(B-R)缓冲溶液和在模拟尿样中的回收率分别为(101.7±3.8)%和(96.3±3.3)%。结论:该方法可灵敏测定微量异烟肼,可用于临床结核病患者药物浓度的监测。  相似文献   

2.
目的探讨利用微分脉冲伏安技术测定全血中尿酸的电化学分析方法。方法玻碳电极在1mol/LNaOH溶液中活化,用循环伏安法研究尿酸在活化玻碳电极上的氧化还原特性,用微分脉冲伏安法直接测定尿酸的含量。结果在0.1mol/L的醋酸缓冲溶液中(pH5.0),尿酸在活化玻碳电极上于0.484V处产生一个灵敏的氧化峰。微分脉冲伏安法测定其氧化峰电流与尿酸的浓度在5.0×10-6~2.0×10-4mol/L范围内呈良好的线性关系,相关系数为0.9989,检出限为1.0×10-6mol/L。能在抗坏血酸存在下同时测定尿酸。结论方法操作简单方便,重现性较好,用于人血中尿酸的测定,结果令人满意。  相似文献   

3.
目的:探讨槐定碱在玻碳电极上的电化学反应机制及分析方法.方法:在硼酸-氯化钾-碳酸钠(A-P)缓冲溶液(pH 7.4)中,采用循环伏安、计时电量、恒电位电解并结合紫外光谱法研究槐定碱在玻碳电极上的电化学反应机制,利用差示脉冲伏安法建立槐定碱的电化学分析方法.结果:槐定碱在玻碳电极上产生一不可逆的氧化峰,峰电位为0.875 V,是两电子两质子的不可逆扩散氧化波,电荷转移系数为0.44,电极表观电子传递速率常数为7.12 × 10-3s-1;扩散系数为2.16 × 10-5 cm2/s;其峰电流与槐定碱浓度在8.0 × 10-6~3.0 × 10-4 mol/L范围内呈线性关系,检出限为2.0 × 10-6mol/L.结论:推导出了槐定碱的电极反应机制,可用于模拟生物样品中槐定碱的含量测定,结果满意.  相似文献   

4.
目的:探索羟苯磺酸钙(CD)在裸玻碳(GC)电极上的电化学行为,并考察该电极测定CD的最优条件及对实际样品的分析应用.方法:采用循环伏安法研究裸GC电极上CD的氧化还原性质.结果:在0.5 mol·L-1的H3 PO4(pH 1.1)溶液中,CD的伏安曲线表现出一对明显的氧化峰(Epa为0.74 V)和还原峰(Epc为...  相似文献   

5.
目的:研究一种新型的电化学方法测定痕量奥硝唑(ONZ)。方法:用阳极氧化及循环伏安法得到预处理玻碳电极,并测定痕量ONZ。结果:预处理玻碳电极对ONZ具有灵敏的电化学响应,还原峰电位为-0.66V(vsSCE),还原电流与ONZ的量成正比,其线性范围为1.9×10-6~2.0×10-4mol/L(r=0.999),检测限为7.6×10-7mol/L(3倍的信噪比)。结论:该方法灵敏度高,稳定性好,干扰少,操作简单,可用于ONZ的痕量测定。  相似文献   

6.
维生素B6在电化学活化玻碳电极上电化学行为的研究   总被引:3,自引:0,他引:3  
玻碳电极(GCE)经阳极氧化(+1.8V)和循环扫描(-1.5V-+1.6V)的方法预处理得到的电化学活化玻碳电极(PGCE),在0.2mol/L PBS(pH6.0)中,循环伏安图有一对氧化还原峰。用循环伏安法、线性扫描伏安法和示差脉冲伏安法研究了VB6在PGCE上的电化学行为;这种PGCE亦可用来研究VB6的代谢产物,并同时测定VB6及吡哆喹的两种异构体。  相似文献   

7.
目的为了研究多巴胺的测定,并有效排除抗坏血酸的干扰,制备了聚L-半胱氨酸修饰电极。方法通过电化学方法将L-半胱氨酸修饰到玻碳电极表面,采用线性扫描溶出伏安法对多巴胺进行定量分析。结果实验表明,该修饰电极对神经递质多巴胺的电化学氧化有显著的催化作用,峰电流明显增大,线性范围为2.0×10-7~1.0×10-4mol/L,检出限为2.0×10-8mol/L。结论该聚合物修饰电极具有良好的选择性,用于多巴胺的测定,能有效地排除抗坏血酸的干扰,结果令人满意。  相似文献   

8.
目的:建立同时测定己烯雌酚(diethylstilbestrol,DES)和辛基酚(octylphenol,OP)的电化学方法。方法:通过自组装技术将氧化石墨烯(graphene oxide,GO)组装到壳聚糖修饰的玻碳电极表面,构建GO-壳聚糖修饰玻碳电极,用循环伏安法和差分脉冲伏安法研究DES和OP在该修饰电极上的电化学行为及其测定,利用Origin8软件多峰曲线拟合分析实验数据。结果:在p H 7.0磷酸盐缓冲溶液中,同时测定DES和OP的线性范围分别为3.31×10-7~1.24×10-5 mol/L和2.89×10-7~9.50×10-6mol/L,检测限为7.56×10-8 mol/L。且该修饰电极具有良好的重复性和稳定性。结论:GO/壳聚糖修饰玻碳电极测定酚类环境刺激素具有简单、快速等优点,可同时测定DES和OP的混合样品。  相似文献   

9.
目的:制备羧基功能化石墨烯修饰玻碳电极,研究芦丁在该电极上的电化学行为,建立芦丁测定的新方法。方法:分别采用循环伏安法和差示脉冲伏安法研究了芦丁在修饰电极上的电化学行为,优化了包括支持电解质、缓冲液pH、修饰剂用量等测定条件。结果:在10mmol/LpH=7.5的Tris-Hcl缓冲溶液中,还原峰电流与芦丁的浓度对数在4.0×10-7-8.0×10-5mol/L范围内呈良好的线性关系,检出限为1.0×10-7mol/L(S/N=3),加样回收率在97.60%-106.30%。结论:该方法灵敏度高、检测范围宽,已用于复方芦丁片中芦丁的测定,结果令人满意。  相似文献   

10.
目的 建立聚脯氨酸修饰电极测定去甲肾上腺素的新方法,并有效排除肾上腺素与抗坏血酸干扰.方法 在pH 9.0的磷酸盐缓冲溶液中.用循环伏安法制备了聚脯氨酸修饰电极,研究去甲肾上腺索在聚合物薄膜上的电化学行为,建立测定去甲肾上腺素的电化学分析新方法.结果 在pH 7.0的磷酸盐缓冲溶液中,去甲肾上腺素在修饰电极上呈现一对灵敏的氧化还原峰,利用循环伏安法测定其还原峰电流可排除肾上腺素与抗坏血酸干扰.去甲肾上腺素检测的线性范围是7.0×10-7~1.1×10-4mol/L:检出限为6.0×10-8mol/L.结论 该修饰电极具有良好的灵敏度、选择性和稳定性,用于药剂样品分析,结果满意.  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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