叶轮机械颤振稳定性工程预测方法在跨音风扇中的进一步探讨

通过求解雷诺平均NS方程并采用影响系数法,对三个基本正交模态的三维振荡跨音风扇叶片绕流问题进行了研究,并基于刚体运动假设和模态叠加法,得到了可用于叶轮机械设计阶段颤振稳定性评估的稳定性参数图。结果表明,跨音风扇内部,激波对非定常气动力的分布具有主导作用;通过对稳定性参数图的分析表明,在一定情况下振型对颤振稳定性有重要影响,应将其作为颤振稳定性设计的重要参数之一;跨音风扇和亚音低压涡轮的稳定性参数图对比分析表明,二者稳定性参数分布形式具有相似性。     

压气机转子叶片的气动弹性数值模拟

采用了交替迭代算法，对某压气机转子叶片进行了气动弹性数值模拟。自行开发了基于有限元的结构求解器用于结构动力学求解，引用他人开发的非定常流体求解器用于气动力的求解。结构求解器提供叶片的表面位移给流体求解器以改变流场，流体求解器提供气动载荷给结构求解器来计算叶片的变形，界面处理系统在这两个求解器之间进行信息传递。算例表明，这种交替迭代算法在气动弹性数值模拟中是可行的，可以得到叶片的瞬态响应，从而判断叶片是否发生颤振。     

应用Delphi法构建城乡结合部药品安全综合评价指标体系研究

目的构建城乡结合部药品安全状况综合评价指标体系。方法通过两轮德尔菲法专家咨询,确定一、二级指标项及各自权重。结果两轮咨询专家的积极系数分别为90%和100%,专家权威系数为0.78,专家意见协调系数高于0.5,最终确定了包含3个子系统,12个一级指标及37个二级指标的城乡结合部药品安全状况综合评价指标体系。结论本研究构建的城乡结合部药品安全状况综合评价指标体系具有科学性、合理性及现实指导意义。     

拉西地平软胶囊研制

目的：制备拉西地平软胶囊,解决现有剂型生物利用低的问题。方法：筛选处方制备拉西地平软胶囊,并参照中国药典进行崩解时限、含量测定、均匀度检测。结果：确定了软胶囊处方及工艺,经检测各项指标均符合规定。结论：采用本试验处方,旋转模法制备拉西地平软胶囊可行,各项指标符合规定。     

评价诊断试剂试验的标准

评价诊断试剂试验标准应包括两方面:真实性(Validity)和可靠性(reliability).1.真实性(Validity):真实性指测量值与实际值符合的程度.(诊断试验应能提供哪些人确实有病(真阳性)和哪些人确实无病(真阴性)的指标,这是试验的真实性).评价真实性的两个指标:灵敏度(Sensitivity)及特异度(Specificity).(在考核一种试验标准时,通常用同一试验方法分别对一组已知有病(真阳性)和另一组已知无病(真阴性)的人进行检查,然后比较二者的结果而确定这两个指标).     

用综合评价方法构建医院药学人员绩效考核体系

目的:探索构建医院药学人员绩效考核体系。方法:通过德尔菲法咨询院内、外9位专家,确定绩效考核体系构建方法,即采用综合评价方法,包括平衡计分卡法、关键绩效指标法和360度考评法等方法,形成初步的考核指标及权重,再通过问卷方式调查北京市9家三级甲等综合医院360名药学工作人员(占药学工作人员总数的37%),确定最终的考核体系。结果:根据医院药学不同岗位的职责,确定了各岗位的绩效考核指标及权重,指标包括日常工作、顾客评价、内部流程和学习与成长4个维度,赋予日常工作指标总分100分,后3个维度的指标采用在第1个指标得分基础上加减分的方式,以分值占总分的比重来体现指标的权重,从而构建了一套绩效考核体系。结论:通过综合评价方法构建的医院药学人员绩效考核体系较为全面、客观,为实施有效的绩效管理打下基础。     

乙酰化代谢表型与膀胱癌关系的研究

以咖啡因为代谢探针，对２０３例中国健康志愿者和６７例膀胱癌患者的Ｎ－乙酰化代谢表型进行了对比研究。根据人尿液中咖啡因代谢物５－乙酰氨基－６－甲酰氨基－３－甲基尿嘧啶和甲磺嘌呤的峰高比值绘制概率分布直方图和概率单位图，寻找区分快慢乙酰化代谢表型的临界点，确定人的乙酰化代谢表型。     

基于德尔菲法确定《心脏外科人血白蛋白合理使用快速建议指南》的临床问题及结局指标

摘要：目的:人血白蛋白广泛用于心脏外科围手术期患者的综合管理中,但国内外缺乏相关指南及共识,课题组严格遵循指南制定规范,制定《心脏外科人血白蛋白合理使用快速建议指南》,旨在促进人血白蛋白的合理使用。方法:项目专家组各位专家通过三轮德尔菲法完成本指南临床问题及结局指标的确定。结果:第一轮共有3个临床问题与14个结局指标达成共识,补充了6个临床问题与1个结局指标;第三轮有10个临床问题与1个结局指标进一步达成共识。最终共有13个临床问题在本指南中必须形成推荐意见或说明（纳入）,4个临床问题需根据证据质量与专家共识决定是否形成推荐意见（待定）,形成14个关键结局,1个重要结局。结论:本研究通过三轮德尔菲法调查确定了需要纳入《心脏外科人血白蛋白合理使用快速建议指南》的临床问题与结局指标,为指南的后续制定工作奠定了良好的基础。     

唇裂鼻畸形患儿术后鼻模矫正的临床效果

目的 探讨唇裂鼻畸形患儿在术后佩戴鼻膜对鼻畸形矫正的效果.方法 30例单侧完全性唇裂患儿随机分为观察组与对照组,其中术后佩戴鼻模的观察组15例,未佩戴鼻模的对照组15例.两组患儿在性别、年龄上无明显差异;术后一周及一年分别拍摄两组患儿安静状态下鼻部照片,测量出每位患儿鼻孔正常侧与患侧的高度与宽度,求出两侧高度与宽度的差值,同时测量出每位患儿鼻小柱的倾斜度,算出每组各项指标的均数及标准差,两组进行比较.结果 测量数据显示在术后一周时,两组患儿各项指标对比无明显差异,在术后一年观察组的每项指标患侧与健侧差异更小,与对照组比较,均有明显差异.结论 单侧完全性唇裂鼻畸形患儿在术后坚持佩戴鼻模可以有效改善鼻外形,在改善患儿外貌的同时,为鼻畸形二期修复创造条件.     

DNA序列分析中混沌图的应用

<正> 混沌理论不但是数学和物理学的研究前沿之一,而且对生物学、医学乃至经济学研究都产生了重大影响。利用该理论在微机上编制相应的程序,对DNA序列分析可提供一种直观的、有效的方法。这是由分子生物学,概率统计和计算机科学交缘而形成的研究工作。它显示了微机在医学、生物学科研中具有强大的生命力,具有广阔的前景。 我们根据混沌理论用BASIC语言在IBM微机上编制了两个实用程序,由数据模     

Clinical Decision Analysis Modeling: Short-Term Control of Ventricular Response Rate in Atrial Fibrillation or Atrial Flutter—Digoxin versus Diltiazem

Objective . To develop a clinical decision model to compare the outcome of therapy with digoxin versus diltiazem for short-term control of ventricular response rate (VRR) in patients with atrial fibrillation or atrial flutter. Design . Review of data from two studies that examined the percentages of response and frequency of adverse reactions in patients treated with intravenous digoxin or diltiazem to control VRR in atrial fibrillation or flutter. We constructed a clinical decision model and performed sensitivity analysis to determine if the model's predictions could be altered. Setting . Large teaching, university hospitals. Participants . Adults age 18 years or older treated with intravenous digoxin or intravenous diltiazem for atrial fibrillation or flutter (VRR > 120 beats/min). Patients with severe heart failure New York Heart Association class III or IV, a surgical procedure prior to the exacerbation, or an acute myocardial infarction were excluded. Measurements and Main Results . We measured VRR control after 1 and 24 hours of therapy (VRR < 100 beats/min or decrease of ≥ 20%) and assessed the likelihood that a patient would suffer an adverse drug reaction. Initial assumptions were that the probability digoxin would achieve VRR control was 0.10 (95% confidence interval 0.04–0.20) at 1 hour and 0.70 (95% CI 0.56–0.80) at 24 hours; the probability that diltiazem would achieve VRR control was 0.94 (95% CI 0.82–0.99) at 1 hour and 0.83 (95% CI 0.68–0.94) at 24 hours; and the probability of no serious adverse drug reaction would be 0.90 (95% CI 0.80–0.96) for digoxin and 0.96 (95% CI 0.86–0.98) for diltiazem. Results . Diltiazem was superior to digoxin with respect to the composite end point score at 1 hour (91.20 vs 17.29) and 24 hours (81.65 vs 66.43). Digoxin was superior to diltiazem at 24 hours only if the VRR was assumed to be at the highest 95% CI limit for digoxin and simultaneously at the lowest 95% CI for diltiazem (74.62 vs 68.63). Conclusions . Clinical decision analysis suggests that intravenous diltiazem is superior to intravenous digoxin in controlling VRR in patients with atrial fibrillation or flutter.     

决奈达隆治疗房颤/房扑临床试验荟萃分析

目的:评价决奈达隆治疗房颤/房扑的疗效和安全性。方法:采用荟萃分析方法,检索公开发表的决奈达隆治疗房颤/房扑的临床试验,由2名评价者独立评价纳入研究质量、提取资料并交叉核对。采用RevMan5.0软件进行效应指标异质性检验和汇总分析,评估其安全性。结果:共纳入5个随机对照试验。各指标汇总分析显示,决奈达隆较安慰剂降低房颤/房扑患者因心血管事件住院或全因死亡率[相对危险度(RR)=0.76,95%CI(0.72,0.79),P<0.00001],能减慢房颤/房扑发作时的心室率[加权均数差(WMD)=-14.60,95%CI(-15.06,-14.14),P<0.00001],但并不降低房颤/房扑的复发率[RR=0.96,95%CI(0.80,1.16),P=0.68]。决奈达隆有较好的耐受性。结论:决奈达隆治疗房颤/房扑安全、有效,尚需高质量、大规模随机对照试验进一步研究证实。     

The Impact of Dose and Solubility of Additives on the Release from HPMC Matrix Tablets—Identifying Critical Conditions

Purpose  The dissolution of HPMC matrix tablets containing different amounts of highly soluble (mannitol) or poorly soluble (dicalcium phosphate, DCP) was studied to deduce the parameters critical to release robustness. Methods  The release of HPMC and additives was studied using a modified USP II method at two paddle stirring rates, 50 and 125 rpm, at HPMC content varying from 15% to 100%. Results  At HPMC contents between 30% and 35% a critical point was identified and found crucial to the release from the HPMC/mannitol tablets. Below this point the matrix rapidly disintegrated in a non robust manner. At higher HPMC contents the mannitol release became increasingly diffusion controlled with maintained matrix integrity. The release robustness was lower for HPMC/DCP than HPMC/mannitol tablets at high HPMC contents, however, lacking critical points. The critical point was interpreted as the percolation threshold for HPMC and differences explained in terms of water transport into the matrix. Conclusion  The release robustness was lower for formulations with additives of low solubility having an erosion controlled release than for additives with higher solubility and a diffusion controlled release. However, for additives creating a steep osmotic pressure gradient, an HPMC content above the percolation threshold becomes vital for maintaining the release robustness.     

Altered Protein Binding of Quinidine in Patients with Atrial Fibrillation and Flutter

Study Objectives . To determine if α₁-acid glycoprotein (AAG) concentrations are altered in patients with atrial fibrillation and flutter (AFF), and to establish if fluctuations in AAG change the free fraction of quinidine. Design . Prospective, controlled, nonrandomized. Setting . Tertiary care medical center and outpatient clinics. Patients . Thirty patients with AFF and 16 matched controls. Interventions . Serial blood samples were collected from patients with AFF at baseline and for 28 days after cardioversion. The control group received no treatment and a single blood sample was obtained. Measurements and Main Results . Concentrations of AAG were measured by Laurell-Rocket immunoelectrophoresis. Quinidine concentrations were determined by fluorescence polarization immunoassay using the Abbott TDx system. Baseline AAG concentrations in patients with AFF (122 ± 55 mg/dl) were significantly increased compared with the control group (62 ± 28 mg/dl, p<0.0005). Concentrations of AAG remained elevated after conversion to sinus rhythm and did not significantly change over the study period, regardless of method of cardioversion (p>0.2). In patients with AFF, the free fraction of quinidine at the highest AAG concentration was 8.5 ± 2.3%. This was significantly reduced compared with the value in the control group (12.5 ± 3.0%, p<0.05) as well as that in patients with AFF at the lowest AAG concentration (11.0 ± 2.5%, p<0.05). Overall at the highest AAG concentration, patients with AFF had a relative reduction in the quinidine free fraction by 32% compared with controls. Regression analysis showed an indirect relationship between serum AAG concentration and the unbound fraction of quinidine (r=0.56) Conclusions . Concentrations of AAG are increased in patients with AFF and remain elevated for at least 28 days after cardioversion. Elevated AAG concentrations significantly reduce the free fraction of quinidine.     

Analysis of Antithrombotic Therapy After Cardioembolic Stroke Due to Atrial Fibrillation or Flutter

Background:

Guidelines recommend that all patients with atrial fibrillation and a history of ischemic stroke should receive an anticoagulant. Prior analyses show that warfarin is underutilized in most populations.

Objective:

To examine the use of antithrombotic and anticoagulant therapy in patients with atrial fibrillation or flutter during the index hospitalization for acute, ischemic stroke.

Methods:

Retrospective electronic medical record review of 200 patients treated at a tertiary care hospital with a primary ICD-9 code for ischemic stroke and a secondary ICD-9 code for atrial fibrillation or flutter. Exclusion criteria were active bleeding, pregnancy, age less than 18, pre-existing warfarin allergy, or dabigatran use.

Results:

Fifty-two percent of patients received at least one dose of warfarin during the index hospitalization. There was no relationship between CHADS₂ score and likelihood of receiving warfarin (P > .05). There was no significant difference in adverse event rate in patients receiving warfarin compared to those receiving aspirin (3.8% vs 9.1%; P = .14), but the rate of hemorrhagic transformation was lower in patients receiving warfarin (1% vs 7%; P = .03). The composite of hemorrhagic stroke or hemorrhagic transformation was significantly lower in patients receiving bridging therapy (0% vs 11%; P = .03). Sixteen patients were readmitted for stroke within 3 months of discharge. Ten were readmitted for ischemic stroke, 3 for hemorrhagic stroke or hemorrhagic transformation, and 3 for systemic bleeding. Ten patients (62.5%) were receiving warfarin at readmission, but only one of these patients had a therapeutic INR.

Conclusions:

Warfarin was underutilized as secondary stroke prophylaxis in these high-risk patients. Bridging therapy appeared to be safe and was not associated with an increase in adverse events.     

Selection of test series by a modified multidimensional mapping method

Maintaining a realistic minimum distance between compounds in a defined multidimensional parameter space ensures well-spread sets of parameter values. It has been suggested, however, that the use of this multidimensional mapping method may lead to series of compounds with high multicollinearities of parameter values. An alternative method, multidimensional mapping by distance and determinant, is discussed here. This method maximizes the determinant of the interparameter correlation matrix as well as maintaining the minimum distance criterion. Its performance is compared with other methods, and it is shown that collinearities may be overcome or maintained at low levels when this method is used.     

三维标测系统Carto指导下标测、消融典型心房扑动

目的评价Carto三维标测系统标测、消融典型心房扑动的临床疗效。方法 14例典型心房扑动患者,采用Carto指导下右心房电解剖重建和激动顺序标测,冷盐水灌注导管消融三尖瓣峡部终止心房扑动,并通过起搏刺激验证消融线双向阻滞。观察消融即刻成功率、手术时间、消融时间和X线曝光时间以及并发症情况。通过随访,评价导管消融后远期疗效。结果 Carto指导下右房激动顺序标测证实10例为I型房扑、4例为Ⅱ型房扑。所有患者均在消融中终止心房扑动,平均手术时间（2.5±0.5）h,X线曝光时间（15±5.5）min。所有患者术中即刻均实现消融线两侧双向传导阻滞,S-A间期平均（120±15）ms。平均随访6个月,无心房扑动复发。结论 Carto指导下标测、消融典型心房扑动疗效肯定,同时可显著减少X线暴露及消融手术时间。     

Comparison of Intravenous Diltiazem and Verapamil for the Acute Treatment of Atrial Fibrillation and Atrial Flutter

Study Objectives . To compare the efficacy and safety of intravenous diltiazem and verapamil in controlling ventricular rate in patients with atrial fibrillation or flutter, and to evaluate the effects of these agents on left ventricular systolic function. Design . Prospective, randomized, double-blind, crossover study. Setting . University-affiliated hospital and Veterans Administration hospital. Patients . Seventeen men with atrial fibrillation or flutter with a ventricular rate of 120 beats/minute or higher and a systolic blood pressure of 100 mm Hg or greater. Interventions . Patients received up to two intravenous boluses of either diltiazem or verapamil, followed by an 8-hour continuous infusion if a therapeutic response was achieved (phase I). After a washout period, patients who responded were crossed over to receive the other drug in a similar fashion (phase II). Measurements and Main Results . At the end of each infusion, the patient's ejection fraction was assessed by gated angiography. Of the 17 men initially randomized, 8 successfully completed both phases I and II. In these patients, baseline mean (± SD) ventricular rates before treatment with intravenous diltiazem and verapamil were 138 ± 15 and 132 ± 9 beats/minute, respectively (NS). At 2 minutes after the initial bolus dose, the mean ventricular rate decreased to 100 ± 13 beats/minute in the diltiazem group compared with 114 ± 17 beats/minute in those receiving verapamil (p<0.05). Mean ventricular rates of 96 ± 11 and 97 ± 9 beats/minute were maintained during the 8-hour continuous infusion of diltiazem and verapamil, respectively (NS). On completion of the bolus dose(s) and during continuous infusions, there were no significant differences in blood pressures between the groups. Mean ejection fractions were 35.6 ± 13.6% and 35.5 ± 15.4% in the diltiazem and verapamil groups, respectively (NS). For the 17 patients, the mean maximum percentage decreases in blood pressure were not significantly different between groups. However, three patients developed symptomatic hypotension all of whom were randomized to receive verapamil initially. Conclusion . Intravenous diltiazem and verapamil are comparable in terms of efficacy and effect on systolic function in patients with rapid atrial fibrillation and flutter. However, hypotension may limit therapy with verapamil in some patients.     

Interplay of formulation and process methodology on the extent of nifedipine molecular dispersion in polymers

The aim of this study is to evaluate effects of formulation and process technology on drug molecular dispersibility in solid dispersions (SDs). Nifedipine solid dispersions with ethylcellulose (EC) and/or Eudragit RL (RL) prepared by co-precipitation, co-evaporation, and fusion methods were characterized with FTIR, DSC, and XRPD for the content of nifedipine as molecular dispersion, amorphous and/or crystalline suspensions. A method was developed based on regular solution and Flory-Huggins theories to calculate drug-polymer interaction parameter in solid dispersion systems. A synergic effect of RL and EC on nifedipine molecular dispersibility in solid dispersions was observed. Increasing RL/EC ratio resulted in a higher degree of drug-polymer interaction that thermodynamically favored molecular dispersion, which, however, was counteracted by a corresponding decrease in the matrix glass transition point that kinetically favored phase-separation. Process methodology was found to play an important role in the formation of amorphous SD. The ranking of technologies with respect to the extent of molecular dispersion from high to low is fusion > co-evaporation > co-precipitation, wherein the solidification rate of polymeric solution and non-solvent effects were linked to kinetic entrapment of drug molecules in polymeric networks. Since nifedipine molecular dispersibility in EC/RL polymer(s) is a result of interplay between thermodynamic and kinetic factors, nifedipine molecular dispersions prepared for this study are thermodynamically metastable systems. To explore those supersaturation systems for use in drug delivery of poorly water soluble drugs, it is critical to balance drug-polymer interactions and matrix glass transition point and to consider a process technology with a fast solidification rate during formulation and process development of amorphous SD.     

Behaviour of HPMC compacts investigated using UV-imaging

The aim of the study was to visualize the behaviour of the hydroxypropyl methylcellulose (HPMC) in a buffer solution using UV imaging. The obtained results were related to rheological measurements in order to gain insight into critical polymer properties affecting drug release. Two viscosity grades of HPMC, 15cP and 50 cP, were used. The behaviour of the polymer at the surface of the compact was observed by UV-imaging at 214 nm for 90 min in a stagnant buffer solution and in presence of flow. Steady shear and oscillatory shear measurements were conducted to determine the rheological characteristics. Three distinctive phases could be detected by real-time UV-imaging of the HPMC; gel formation due to water penetration, further expansion of the gel into solution and finally steady conditions, where a critical polymer concentration that can withstand the shear forces without eroding was observed. The critical concentration corresponded to the rheologically determined gel point, which is the lowest concentration where a 3D-network is obtained. Higher viscosity grade HPMC swelled more rapidly and lead to a thicker gel layer, which was more resistant towards the shear forces due to the applied flow. The results showed that UV imaging is suitable for obtaining both qualitative and quantitative information on polymer behaviour.