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1.
TBP从盐酸溶液中萃取Sn~(4+)时,其稀释剂的影响不仅与稀释剂的性质有关,而且与盐酸浓度,萃取剂浓度,初始水相中锡的浓度等有关。只有[HCl]<6mol/L,[TBP]<40%,[Sn~(4+)]_(in)<1.5g/L时,才能排除这些因素的影响,因为这时各种稀释剂对Sn~(4+)的分配比D_(Sn~(4+))随这些因素的变化趋势相一致。在TBP-SnCl_4-HCl体系中,对于非极性类稀释剂,若按D_(Sn~(4+))的大小来排列,则烷烃类(环己烷、正己烷、正庚烷)>芳烃类(苯)>卤代烃类(四氯化碳),且可用稀释剂的极化率与摩尔体积等因素来解释;对于极性类有接受电子基团的稀释剂,则硝基苯>1,2-二氯乙烷>氯苯>氯仿,可用稀释剂的偶极矩、介电常数、溶解度参数或粘度等物性参数来解释其规律。  相似文献   

2.
目的以杏仁为原料,研究超临界CO2萃取杏仁油的工艺条件。方法在对萃取压力、萃取温度、分离压力、萃取时间的单因素考察试验的基础上,设立L9(34)正交试验,考察上述各因素对杏仁油萃取率的影响。结果各因素对杏仁油萃取率的影响为分离温度(B)〉萃取温度(A)〉萃取时间(D)〉萃取压力(C),并得出最优工艺条件为A2B2C1D2,即萃取温度为50℃,分离温度为40℃,萃取压力为350Bar,萃取时间为3.5h。结论利用超临界CO2萃取杏仁油,提取率高、产品纯度好,工艺简单、稳定、可行。  相似文献   

3.
目的 采用超临界萃取技术从冬凌草中萃取冬凌草甲素。方法 以冬凌草甲素的提取率为指标,通过正交试验考察萃取工艺条件,得到冬凌草甲素的超临界CO2适宜的萃取工艺条件,采用HPLC法对萃取物进行定量分析。结果 冬凌草甲素的超临界CO2适宜的萃取工艺条件为:压力35 MPa,温度328.15 K,夹带剂流量4 mL/min,CO2流量25 g/min,各影响因素对萃取收率的影响程度:夹带剂流量>压力>温度>CO2流量。冬凌草甲素的提取率为0.402%,优于文献中报道的039%的提取率。结论 采用超临界萃取技术从冬凌草中萃取冬凌草甲素实用可行。  相似文献   

4.
目的对比观察病人不同药物配伍自控静脉镇痛(patient controlled intravenous analgesia, PCIA)对显微手外科术后的镇痛效果与副反应。方法3 200例四肢创作需皮瓣修复住院病人根据PCIA泵使用镇痛药物不同随机分为A吗啡0.300~0.500 mg/kg、B芬太尼0.010~0.015 mg/kg、C曲马多0.010~0.015 mg/kg、D芬太尼0.005~0.008 mg/kg+曲马多0.005~0.008 mg/kg4类,每类又根据复合氟哌利多、氟哌利多+咪唑安定、恩丹西酮、恩丹西酮+咪唑安定不同分为4组,每组200例。重点观察术后48h内出现的副反应。结果4类16组术后副反应发生率A类(A1>A2>A3≥A4)>B类(B1>B2>B3≥B4)>C类(C1>C2>C3≥C4)>D类(D1>D2>D3≤D4),D类非常显著低于A、B和C 3类(P<0.01)、D1组显著高于D2~D4组(P<0.05)。结论所有自控镇痛PCA配方均可安全用于静脉给药,但就其术后副反应发生率低而言,D类优于A、B和C 3类。芬太尼、曲马多、恩丹西酮和咪唑安定4药联用更适用于显微手外科的术后镇痛。  相似文献   

5.
超临界流体萃取技术在中药分离、精制领域有着重要的作用,目前已初步形成一个新的产业。介绍了超临界流体的萃取原理,超临界流体的种类,影响超临界流体萃取的主要因素,以及该技术在挥发油类、生物碱类、黄酮类、醌类、香豆素与木脂素类、皂苷类中药提取物中的应用。  相似文献   

6.
通过对系列破乳剂D5356、D5456在红霉素萃取时破乳化效果和萃取收率、溶媒收率等的对比,选择最适宜红霉素提炼萃取的破乳剂。  相似文献   

7.
合成了疏水性胍类离子液体,考察室温下离子液体对水溶液中金属离子(Fe3+、Cu2+、Co2+、Ni2+、Zn2+)的萃取能力。实验结果表明该离子液体对Fe3+萃取具有高选择性,萃取率为90%;对其他金属离子萃取率仅为40%左右。为了进一步研究离子液体对Fe3+的萃取性能,分别从两相体积比、萃取时间、金属离子起始浓度及溶液pH等因素研究了其对Fe3+的捕集效果。结果表明:室温下,0.2 mL离子液体与5 mL的FeCl3溶液超声混合5 min后,溶液中Fe3+萃取率为90%;且溶液中金属离子的起始浓度对萃取效果影响较小,但溶液pH对其影响较大。通过实验与理论计算发现,离子液体对Fe3+的萃取过程存在阳离子交换与离子对的共同作用机制,但离子对作用占主导地位。  相似文献   

8.
研究了磷氧类萃取剂对稀水溶液中衣康酸的萃取行为,考察了溶剂配比、料酸浓度、操作温度等因素的影响。测定并关联了相平衡数据,证实萃合物为H_2Ita·(TBP)_2·H_2O。对于浓度约为40g/L的衣康酸发酵液,建议用50%TBP-ker为萃取剂,在室温(298 K)下萃取,反萃取用353 K热水。  相似文献   

9.
三十年来,多巴胺功能亢进假说是解释精神分裂症病因机制的主要生化假说.近年对精神分裂症患者脑中多巴胺受体的研究日益深入.多巴胺受体根据其对腺苷酸环化醇(AC)活力的不同影响被分成D1类受体和D2类受体,即D1类受体被激动时可激活AC的活性,而D2类受体被激动时则可抑制或不影响AC的活性.随后又根据这些受体对不同多巴胺(DA)受体激动剂或拮抗刑选择性、亲和力的不同,将D1类、D2类受体分别分成D1、D5受体和D2、D3、D4受体.本文着重介绍D4受体.一、关于D4受体:1.D4受体的结构特征:D4受体属于G蛋白们联的受体族,其肽…  相似文献   

10.
江苏是全国医药产业的重要集聚区域,在全国医药产业占据着举足轻重的地位,产业集群知识溢出效应的发挥对于江苏医药产业的发展具有重大影响。运用R&D投入、知识势差、知识溢出壁垒和接收方学习能力等指标对江苏医药产业集群知识溢出效应进行实证分析,得出知识势差和知识接收方的学习能力对知识溢出效应有显著正向影响,R&D投入和知识溢出方设置的壁垒对知识溢出效应有影响但不显著的结论,并基于结论提出了强化创新人才战略、推动骨干企业与中小企业合作模式创新等促进江苏医药产业集群知识溢出的建议。  相似文献   

11.
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   

12.
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   

13.
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   

14.
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   

15.
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   

16.
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   

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.
Journal of Nanjing Medical University (English Edition) JNMU, sponsored by Nanjing Medical University, was established in 1987. It is a bimonthly comprehensive English medical journal published locally and abroad.Since 2007, Journal of Nanjing Medical University (English Edition )was granted Elsevier the full publishing and distribution rights worldwide for the Electronic Edition, excluding the People's Republic of China.  相似文献   

19.
Objective To measure Derpl and Blot5 allergen levels in asthmatics' homes in Hongkong.Methods Seventy houses were enrolled for a mite indoor environment study. Dust samples were obtained from two sites of each patients' house: bed and floor. Derpl and Blot5 levels were quantified by a two-site monoclonal antibody-based ELISA technique.Results The levels of Derpl allergens found in bed (geometric mean (GM) 3.43 μg/g of dust; 95%CI, 1.89-4.96 μg/g)and on the floor (GM 1.12 μg/g of dust; 95%CI, 0.71-1.53 μg/g) indicated significant differences (P=0.005). However, the levels of Blot5 allergens found in bed (GM 19.00 μg/g of dust; 95%CI, 0.89-38.90 μg/g) and on the floor (GM 6.14 μg/g of dust; 95%CI, 0.40-11.90 μg/g) showed no statistically significant difference. In addition, in regards to the exposure index for Derpl and Blot5 allergens found in bed and on the floor, 17.6% in bed and 8.6% on the floor had levels of Blot5 ≥ 10 μg/g of dust, higher than those obtained for Derp1 (7.2% and 0% in bed and on the floor respectively, P< 0.05); higher percentages in bed and on the floor (25.0% and 35.7%) were observed for levels of Blot5 =0 μg/g of dust as compared with Derpl in bed and on the floor (4.3% and 14.5% respectively, P< 0.05).Conclusions Derpl and Blot5 are the major allergens found in this regional study, Blot5 is a more potent allergen in Hongkong, probably reflecting the high level of exposure to Blomia tropicalis (Bt). Bt and Dermatophagoides pteronyssinus (Dp) allergens should be included for precise diagnosis and effective immuno-therapeutic treatment of mite allergy in Hongkong.  相似文献   

20.
ANTI-PROLIFERATION EFFECT OF ORIDONIN ON HL-60 CELLS AND ITS MECHANISM   总被引:4,自引:0,他引:4  
Objcetive To investigate the anti-proliferation effect of oridonin on leukemic HL-60 cells and its mechanism. Methods HL-60 cells in vitro in culture medium were given different concentrations of oridonin. The inhibitory rate of cells were measured by microculture tetrazolium (MTT) assay, cell apoptotic rate was detected by flow cytometry (FCM), morphology of cell apoptosis was observed by hoechst 33258 fluorescence staining, and the activity of telomerase was detected using telomere repeat amplification protocol (TRAP) PCR-ELISA before and after apoptosis occurred. Results Oridonin could decrease telomerase activity, inhibit growth of HL-60 cells, and cause apoptosis significantly. The suppression was both in time- and dose-dependent manner. Marked morphological changes of cell apoptosis including condensation of chromatin and nuclear fragmentation were observed clearly by hoechst 33258 fluorescence staining especially after cells were treated 48-60 hours by oridonin. Conclusions Oridonin has apparent anti-proliferation and apoptotic effects on HL-60 cells in vitro, decreasing telomerase activity of HL-60 cells may be one of its most important mechanisms. These results will provide strong laboratory evidence of oridonin for clinical treatment of acute leukemia.  相似文献   

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