首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 60 毫秒
1.
搅拌反应器是进行气液吸收动力学研究的常用设备。近年来,它广泛地用于吸收剂筛选和化学吸收模型的研究。本文所用的搅拌反应器与Danckwerts和Gillham以前使用过的反也器相似。对搅拌反应器的特性我们采用CO_2-H_2O系统和CO_2-无机盐溶液系统进行校正。获得液相传质系数k(?)与R_e,S_c的关联式如下。K_lL/D=6.81×10~(-2)×R_c~(0.79)×S_c~(0.48)  相似文献   

2.
目的 以药理效应法研究超细粉体技术对马钱子药物动力学的影响。方法 以热板法镇痛效应为指标 ,测定了 2种不同粒径马钱子粉末药物动力学参数。结果  2种马钱子粉末给药后体存量的表观动力学过程符合一室开放模型 ,主要药物动力学参数普通马钱子粉为 :Ke =0 .10 94h 1 ,Ka =0 .85 45h 1 ,t1 / 2 (Ka) =0 .8112h ,t1 / 2 (Ke) =6.3 3 5h ,T(peak) =2 .75 86h ,C(max) =2 9.7179mg/kg ,AUC =3 67.3 0 74(mg/kg)·h ,Cl/F(S) =0 .163 4(mg·kg- 1 ) / [h·(mg·kg- 1 ) - 1 ] ;超细马钱子粉为 :Ke =0 .163 7h 1 ,Ka =2 .40 49h 1 ,t1 / 2 (Ka) =0 .2 882h ,t1 / 2 (Ke) =4.2 3 3 9h ,T(peak) =1.1989h ,C(max) =3 0 .415 8mg/kg ,AUC =2 2 6.0 779(mg/kg)·h ,Cl/F(S) =0 .2 65 4(mg·kg- 1 ) / [h·(mg·kg- 1 ) - 1 ]。结论 超细粉体技术既可加快马钱子在体内的吸收 ,使其迅速发挥疗效 ,又可加速马钱子在体内的清除  相似文献   

3.
使用磁钢传动搅拌反应器,在反应温度70—110℃、乙炔压力2 kgf/cm~2和甲醛初始浓度3.3—4.0mol/l的条件下,研究了甲醛水溶液和乙炔在W—1型乙炔铜催化剂上合成丁炔二醇的本征动力学。实验表明,甲醛初始浓度对反应速率有明显的影响。甲醛初始浓度越低,反应速率越大。按並-串联复合反应的经验模型,将实验数据用非线性最小二乘法回归得到的模型表达式如下: r_F=dC_F/dt·V_1/Wcat=2.03×10~2 exp(14024/R_gT)C_F~(1.1) 2.96×10~2 exp(13992/R_gT)C_F~(1.6)C_P~(0.8) r_P=dC_P/dt·V_1/Wact=2.03×10~2 exp (14024/R_gT)C_F~(1.1)-2.96×10~2 exp(13992/R_gT)C_F~(1.6)C_P~(0.8) r_B=dC_B/dt·V_1/Wact=2.96×10~2 exp(13992/R_gT)C_F~(1.6)C_P~(0.8)式中r_E、r_P和r_B分别是甲醛消耗速率、丙炔醇和丁炔二醇生成速率,mol/sec·g,cat。  相似文献   

4.
研究了100℃、120℃、140℃、160℃热引发苯乙烯聚合反应速率在0~95%转化率范围的变化规律,建立聚合反应动力学模型:R_p=A[M],A=(I/(k_1/k_p~2))~(1/2)=A_0+A_1x+A_2x~2+A_3x~3,(x为转化率,A_0,A_1,A_2,A_3不随x变化,与温度有一定函数关系)。发现链引发反应速率常数的变化规律:二级反应的K_(I2)=0.5390×10~7e~(-13 910/T);三级反应的K_(I3)=1.102 4×10~6e~(-14 094/T)。  相似文献   

5.
本文在流体变质量流动动量微分方程的基础上,建立了描述Z型流动径向反应器内流体流动规律的数学模型。该模型为二阶微分方程的边值问题: Au′u″+Buu′+Cu′+Eu~2+F(1-u)~2=0其边界条件为:y=0,u=1;y=1,u=0。式中模型参数A、B、C、E、F决定于Z型流动径向反应器分布流道结构尺寸、穿孔阻力系数和床层空隙率等因素。该数学模型应用于φ600mm径向氨合成塔工况的模拟,验证了模型的适用性。  相似文献   

6.
一次口服芎芍胶囊后犬血清中阿魏酸药代动力学的研究   总被引:14,自引:0,他引:14  
采用反相高效液相色谱法测定犬口服芎芍胶囊后阿魏酸的血药浓度 ,以 3P87药代动力学软件拟合药动学模型。结果表明犬灌胃芎芍胶囊后阿魏酸的体内过程符合开放性一室模型 ,测得药代参数为Ⅰ级吸收速度常数 =0 0 74 9± 0 0 2 0 2 (min- 1) ,Ⅰ级消除速度常数 =0 0 159± 0 0 0 2 0(min- 1) ,半吸收期 =9 73± 2 38(min) ,半衰期 =4 4 2 5± 5 52 (min) ,达峰时间 =2 9 39± 4 10(min) ,血药峰浓度 =150 9 52± 2 75 81(μg/L)。为临床合理用药提供了实验依据。  相似文献   

7.
对气相含氟单体四氟乙烯 ( TFE) /偏氟乙烯 ( VDF) /全氟甲基乙烯基醚 ( PMVE)的乳液共聚反应动力学进行了研究。实验结果表明 ,搅拌速率对共聚反应速率有较大影响 ,搅拌速率在550 r/ min~ 850 r/ min范围内反应速率随搅拌速率增加而增大 ;当搅拌速率大于 850 r/ min时 ,反应速率随搅拌速率的变化趋缓。实验测得 60°C下该三元乳液共聚合反应速率对初始乳化剂浓度、初始引发剂浓度和反应总压力分别呈 0 .0 58级、0 .40 6级和 1 .540级反应 ,由此推导得乳液共聚合的反应速率表达式为 rp=k S0 .0 58I0 .4 0 6p1.54 0 ,其中速率常数 k为 5.78× 1 0 -3 g-0 .4 64 · dm1.3 92 ·( MPa) -0 .54 0·min-1。由上述动力学方程式计算得到的补加单体乳液共聚合反应速率与实验结果一致  相似文献   

8.
采用液体闪烁计数技术研究[~3H]冬凌草乙素在小鼠体内的吸收、分布和排泄。给小鼠经口灌胃(ig)或尾静脉注射(iv)[~3H]冬凌草乙素后,很快被吸收并广泛分布到各组织中。其中以肺、胆囊和肝脏中放射性为最高;其次为肠、胃、胰腺等,肌肉、胸腺和骨中含量最少。iv[~3H]冬凌草乙素3.7×10~7Bq(1.23mg)/kg24h放射性自粪和尿中排泄占总注入量的58.3%。血中放射性—时间曲线表明药代动力学模型似符合二室开放模型。其各时相半衰期分别为T 1/2α=17.9min,T 1?2β=12.7h,其它动力学参数分别为K_(12)=1.38h~(-1),K_(21)=0.84h~(-1),K_(10)=0.15V_c=1.4L kg,V_d=3.9 L kg;ig[~3H]冬凌草乙素3.7×10~7Bq(1.23mg)kg,很快被吸收,其血中放射性—时间曲线似符合二室开放模型,其药代动力学参数分别为T_1 2Ka=17.0min,T_1 2K_e=11.3h.K_a=2.48h~(-1).K_e=0.001min~(-1).以ig和iv[~3H]冬凌草乙素血中放射性—时间曲线下面积计算生物利用度(F)为65%。  相似文献   

9.
为给复方药效成分动力学假说提供实验依据 ,证明方剂的配伍可明显影响彼此在体内化学成分的动力学参数 ,以川芎单煎汤和川芎芍药汤为工具进行了临床药物动力学研究。方法 :采用文献方法 ,测定健康自愿者 1次口服川芎汤(1g/ kg)、川芎芍药 (1∶ 1)汤 (2 g/ kg)后血清中阿魏酸 (FA)的药动学。结果 :2组的血药一时曲线均表现为双峰现象 ,属开放性一室模型。川芎汤和川芎芍药汤组 FA的主要药动学参数分别为 :Ka(L/ m in) =0 .2 816± 0 .132 7和 0 .12 0 6±0 .0 6 2 1;Cmax(ng/ m L) =10 0 .0 844± 34.6 95 5和 47.5 6 76± 2 8.2 35 8;AU…  相似文献   

10.
葛根黄酮缓释胶囊家兔体内药代动力学研究   总被引:20,自引:0,他引:20  
目的 :测定两种自制葛根黄酮缓释胶囊中主要有效成分葛根素在兔体内的药 时曲线 ,测算其体内代谢动力学参数 ,检测其缓释效果。方法 :采用高效毛细管电泳色谱法 ,以愈风宁心片作参比制剂 ,测定不同时间点兔血浆葛根素的量 ,用 3P87程序计算药动学参数。结果 :愈风宁心片及样品制剂在兔体内过程均符合二室开放模型。主要动力学参数参比制剂与样品制剂分别是t1/2 =75 .5 1min ,t11/ 2 =5 0 3.84min ,t2 1/ 2 =4 99.4 8min ,AUC =93.2 7μg/min·ml-1,AUC1=312 .4 0 μg/min·ml-1,AUC2 =318.6 6 μg/min·ml-1,Tp =2 7.6 8min ,T1p =4 8.2 8min ,T2 p =5 5 .90min。结论 :葛根黄酮缓释胶囊呈现一定的缓释效果。  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.
FOR anesthesiologis s ,treatingpostoperativepainhas alwaysbeen a problem.Althoughopioidshave been provedtobe effective,theirsideeffectscouldnotbeignored.With thedevelopmentofscienceand pharmacology,many drugs with aspectsof satisfactoryanalgesicefficacyand couldbe welltoleratedby patientshave been developed.And lornoxicamisone of them, which isa non-steroidalanti-inflammatorydrug (NSAID ), with analgesic, anti-infl-ammatory,andantipyreticproperties.Itseliminationhalf-time(3 to 5 hours) isle…  相似文献   

20.
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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号