顶烧型转化炉的数学模拟——烟气流型对传热的影响

在区域法计算转化炉中辐射传热的基础上,研究了三种烟气流型(活塞流、抛物流、射流)对转化炉中的传热与转化工艺过程的影响。数学模拟结果表明:不同烟气流型时,炉内的温度场和管壁热流量分布的差别是明显的,但对转化过程计算的总结果影响不大;结果均能与工业实测值相吻合。在此基础上定量分析了转化炉管内、管外传热热阻。     

钢水流动与型筒振动耦合对离心铸造炉管壁厚的影响

建立了离心铸造炉管时的钢水流动与型筒振动的耦合模型,结合传递矩阵法,利用MATLAB编程对模型进行求解,得到了各个时刻型筒的振动和内部的钢水分布情况。计算结果表明,离心铸造时的钢水分布与型筒振动相互影响。钢水倒入型筒之后,整个系统的振动性能受到影响,包括振幅和共振转速等。型筒振动会使炉管壁厚产生不均现象：型筒的偏心量越大,炉管壁厚不均程度越严重;倒入的钢水量越大,炉管壁厚不均程度越严重。     

远志属4种药用植物不同干燥方法叶材料DNA提取方法研究

目的:以远志属药用植物为例,对经过不同干燥方法的叶片材料进行DNA提取方法优化研究。方法:在改良CTAB法的基础上,对水浴时间、水浴温度、沉淀时间进行优化。结果:降低水浴温度为45℃,延长水浴时间为5 h,延长沉淀时间为1 h,可以从常温干燥并保存1年的叶片材料和腊叶标本叶材料中提取到用于PCR反应的DNA。结论:硅胶干燥叶片用改良CTAB法可以得到满足后续PCR反应的DNA;对常温干燥并保存1年的干叶片和腊叶标本叶材料,一定时间的低温水浴是提取到满足后续PCR实验DNA的关键。     

携载VEGF基因的聚四氟乙烯血管材料对内皮细胞生长的促进作用

目的:研究聚四氟乙烯(PTFE)血管材料携载血管内皮生长因子(VEGF)基因并促进内皮细胞生长的可行性. 方法:将pCDI-hVEGF121/pCDI质粒溶液处理过的PTFE人工血管修剪成圆片,置于生理盐水中并于0.5, 1, 2, 4, 8, 16,24, 48和72 h测定溶液的吸光度,计算出溶液的DNA浓度,绘出体外释放曲线. 分离和培养人脐静脉内皮细胞,将内皮细胞种植到携带基因质粒的PTFE材料表面,在6, 24, 72和120 h检测细胞增殖情况并用ELISA法检测培养液中VEGF蛋白的表达量. 结果:体外释放曲线提示在0.5～4 h的这段时间内,质粒释放较快,随后进入缓慢增长期,直至72 h仍有质粒的释放. 在24, 72和120 h时间点,VEGF质粒组PTFE材料上的内皮细胞数和增长倍率都明显高于空质粒组材料(P<0.05),在6, 24, 72和120 h时间点,VEGF质粒组培养液的VEGF蛋白水平和增长倍率也明显高于空质粒组(P<0.01). 结论:证实了PTFE材料携带VEGF基因转染内皮细胞并具有促进其生长的可能性.     

白色念珠菌在四种义齿软衬材料表面发育的比较研究

目的比较研究不同义齿软衬材料对白色念珠菌发育的影响。方法将四种不同软衬材料标准试件,用标准白色念珠菌株悬液进行表面黏附后置入沙氏培养液中,通过测定培养液pH值变化研究白色念珠菌在试件表面发育情况。结果各种材料培养液pH均呈时间相关性下降趋势,24h后发育曲线快速下降,到达90-120h后渐趋平缓。结论白色念珠菌软衬材料表面生长呈现早期发育期、快速发育期、稳定期等特点,不同材料其快速发育期持续时间有差异,提示各种软衬材料均有一定抑菌效应并有一定程度的差异,抑菌作用随时间变化显著降低。提示临床上应慎重选择软衬材料。     

兔的顺铂血浆浓度测定及药代动力学研究

顺铂血浆浓度用石墨炉原子吸光谱法测定，检出限为10ng/ml；线性范围为100－800ng/ml；样品加入tritonX-100后可直接进样测定，燕进行6只家兔静脉血顺铂药代动力学研究，2mg/ml剂量快速静脉给药，不同时间取静脉血进行顺铂血浆浓度测定，计算药代动力学参数得：t α/2=0.22h,tβ/2=23.4h,k12=0.34h^-1,K21=0.39h^-1,k10=0.30h^-1,CL=0.098L/kg/h,AUC31.22mg/h／L。     

钛材料在人工唾液中抗腐蚀性能的体外研究

目的 了解钛材料在人工唾液中的抗腐蚀性,为临床选择合适的口腔修复材料提供实验依据和理论基础.方法 选择钛材料,配制不同pH值的人工唾液分别为2.0、3.0、5.0、7.4,检测钛材料在不同人工唾液中24、48、72h钛离子的析出量;此外,检测钛材料与镍不同接触面积对钛离子析出量的影响.结果 钛离子的析出量pH2.0＞pH3.0＞pH5.0＞pH7.4,而钛离子析出量在浸泡时间72h ＞48h ＞24h,pH值为2.0、3.0、5.0时差异有统计学意义（P＜0.05）;而pH值7.4条件下不同时间点的钛离子析出量差异无统计学意义（P＞0.05）.此外,钛与异种金属镍接触面积50mm2相比较,钛镍接触面积100mm2的钛离子析出量较大,差异有统计学意义（P＜0.05）.结论 酸性环境可加速钛离子析出量,影响钛材料的抗腐蚀性.镍钛结合面积的增加会加速钛离子的析出,建议镍过敏的患者慎用钦镍口腔修复材料.     

溶蚀分散型盐酸地尔硫卓艹脉冲控释片的体内外研究

目的：以盐酸地尔硫为模型药物研制溶蚀分散型脉冲控释片并考察其体内外脉冲释药特性。方法：以巴西棕榈蜡、蜂蜡和亲水性纤维素为主要包衣材料,采用干包衣法制备脉冲控释片;通过释放度实验考察处方及工艺因素对脉冲控释片体外释放的影响规律;通过溶蚀实验考察脉冲释药的机制;以高效液相色谱法测定4名受试者的体内血药浓度,研究脉冲控释片的体内药物动力学。结果：该制剂在体外延迟释放时间 t 10为2.1 h,释放至最大的时间 t rm为4.0 h,脉冲释放时间 t 10-90为1.7 h;其体内的延迟释放时间 t lag为5.7 h,达峰时间 t max为8.5 h,从开始释放到达峰的时间 t psi为2.6 h。结论：溶蚀分散型盐酸地尔硫脉冲控释片在体外和体内都具有脉冲释放特性。     

人工合成材料腹膜前修补法在复发性腹股沟疝修补术中的应用(附75例报告)

目的 探讨应用人工合成材料行腹膜前修补法治疗复发性腹股沟疝的疗效,以期寻找治疗复发性腹股沟疝简单有效而又安全的手术方式.方法 回顾性分析2003年2月至2005年2月收治的75例使用合成材料进行腹膜前修补治疗的复发性腹股沟疝患者的临床资料,观察手术时间、术后并发症、留院时间及近期随访的情况.结果 所有患者均治愈出院,均未出现尿潴留,术后1例患者因切口皮下出血而继发感染,5例出现阴囊积液.手术时间平均为35min,术后留院观察2～48h(平均24h),随访6～30个月,无明显异物感,无复发.结论 应用人工合成材料腹膜前修补治疗复发性腹股沟疝操作简便,并发症少,效果良好.     

滚轮与型筒外圆几何误差对离心铸造型筒振动性能的影响

滚轮支承卧式炉管离心铸造机型筒的振动对炉管最终质量有较大影响,而滚轮与型筒外圆的几何误差是形成铸造型筒振动的主要因素之一。本文通过对铸造机型筒的力学分析,建立了描述滚轮与型筒几何误差的数学模型,给出了计算滚轮与型筒接触点坐标的计算方法,进而得到型筒转子受到支承滚轮的激励力随时间变化的计算模型,再应用传递矩阵法,构建了能够在考虑支承滚轮与型筒外圆几何误差的情况下对型筒振动性能进行计算的方法。通过一个具体的算例进行了计算研究,结果表明滚轮与型筒表面几何误差对型筒转子振动性能有显著的影响。     

Value of D-Dimers in patients with acute aortic dissection

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.     

Research of combined liver-kidney transplantation model in rats

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.     

BLOOD PRESSURE CHANGE WITH AGE IN SALT-SENSITIVE TEENAGERS

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.     

安心颗粒对急诊经皮冠状动脉介入术后生活质量影响的研究

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.     

The comparative studies of the influences of Urapidil and Nicardipine on sino-atrial node function, atrio-ventricular node function and hemodynamics

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.     

Expression of OPGmRNA and ODFmRNA in the patients of hip fracture due to osteoporosis

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.     

The clinicopathological and immuohistochemical analysis of solid-pseudopapillary tumor of the pancreas： report of 9 cases

Objective：To investigate the clinical features, pathological characteristics and immunophenotype of solid-pseudopapillary tumor of the pancreas（SPTP）. Methods：Nine surgically treated cases of SPTP were retrospectively reviewed. Hematoxylin and Eosin（HE） staining and immunohistochemical staining were used to analyze all cases, and the general clinical data was collected. Results：Six patients were asymptomatic except for a palpable mass. Two patients complained of vague-epigastric pain. One patient appeared jaundice. The tumor was encapsulated and solid tissues alternately with cystic tissues. Histologically, the histological structure of solid portion was pseudopapillary with a fibrovascular core. Tumor cells were uniform and medium-sized which were arranged in sheets ets or nests or pseudopapillary patterns. Immunohistochemical studies demonstrated that SPTP proved positive in vimentin（9/9 cases）, AAT（9/9 cases）, NSE（9/9 cases）, ACT（7/9 cases）, CK20（2/9 cases）, CgA（1/9 cases）, S-100（3/gcases）, PR（4/gcases）, Syn（3/9 cases） and CD56（5/9cases）, negative in CEA and ER. Conclusion：SPTP is a tumor predominantly occurring in young women frequently without special symptoms. This tumor has various characteristical histological patterns with different immunophenotype.     

Dynamic Changes in Serum Estradiol and Progesterone levels in Patients of Premenstrual Syndrome with Adverse Flow of Liver-qi

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.     

Real-time Three-dimensional Echocardiography in Assessment of Left Ventricular and Right Ventricular Volumes

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.     

SCREENING FOR A 21-CHROMOSOME ABNORMALITY IN PREIMPLANTED EMBRYOS OF ELDERLY WOMEN

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.