波浪式生物反应器温度控制系统模糊PID算法设计及simulink仿真

目的：设计一种波浪式生物反应器温度控制策略。方法根据波浪式生物反应器温度控制精度及响应速度要求,将传统的比例积分微分（ PID）控制方法与模糊控制方法结合,利用模糊控制方法实时在线调节PID控制的参数,增强温度控制策略对温度的调节性能。结果设计出模糊PID控制器,并与传统PID控制器进行仿真比较。结论模糊PID控制法较传统PID控制法有较小的超调以及较短的稳定时间,说明模糊PID控制具有更高的温度控制调节性能。     

基于HPLC-PDA分析丹参-红花药对配伍的化学物质变化规律

目的采用HPLC-PDA技术和"化学模糊识别"策略对丹参-红花药对不同制法、不同配比的活性物质变化规律进行了系统研究。方法通过建立丹参与红花的化学物质库,并经过对照品峰的紫外信息,建立了4类活性物质的紫外信号网络,并通过网络将丹参-红花中的成分进行快速鉴别与归类,进而通过对称配比设计对这些化合物进行定量分析。结果在丹参-红花配伍的水、50%甲醇水和甲醇煎液中,通过"化学模糊识别"策略分别鉴定出47、57和43个成分。3种不同制法中,丹参酮类成分在甲醇提取液中的相对溶出度最高,其他3类成分在50%甲醇水提取液中的相对溶出度最高。相同制法、不同配比中,所测成分总的相对溶出度的优化范围皆为5∶1~5∶2,总的相对溶出度的最高比例皆为5∶2。结论丹参-红花不同配比与不同制法的化学成分的配伍变化规律有所不同,且存在优化配比,为丹参-红花药对临床配伍合理应用提供了参考,为药对现代基础研究提供了思路与方法。     

基于模糊层次分析法优选红花通络方最佳提取工艺路线

目的构建多层次指标评价模型以优选红花通络方(HTP)最佳提取工艺路线。方法选取有效成分、杂质控制、行为学、组织病理学、免疫监测作为准则层,方中代表性成分羟基红花黄色素A、淫羊藿苷的提取率,出膏率,大鼠机械性刺激痛觉超敏反应、机械性刺激痛觉过敏反应的缩足百分率,背根神经节细胞偏心核比率,足底P物质量作为指标层,运用模糊层次分析法(FAHP)为各指标赋权,综合评价HTP各提取工艺路线。结果准则层指标权重(ω)由高到低为免疫监测(ω=0.245)、组织病理学(ω=0.23)、有效成分和行为学(ω=0.20)、杂质控制(ω=0.125)。最佳工艺路线为红花60℃温浸、淫羊藿等水回流提取、桂枝80%乙醇回流提取。结论以FAHP为赋权方法,有效成分指标结合药效学指标和杂质控制作为评价指标来优选提取工艺路线的方法,既能保留复方有效合理的本质,又能满足现代制剂研发的要求。     

模糊综合评价法在清降口腔崩解片处方优化中的应用

目的:采用模糊综合评价法对清降口腔崩解片的主、客观指标同时评价,优化清降口腔崩解片处方,为相关制剂服药顺应性的改善提供参考。方法:采用星点设计法优化清降口腔崩解片的处方,设定3种崩解剂微晶纤维素(MCC),低取代羟丙基纤维素(L-HPC),交联聚乙烯吡咯烷酮(PVPP)和矫味剂(三氯蔗糖+苹果酸)的用量为自变量,在优化过程中,应用模糊综合评价法同时评价该制剂的主观指标(酸甜度、沙砾感程度)和客观指标(崩解时限)。结果:最优处方为清降掩味粉末2 g,MCC 1.472 g,L-HPC 0.398 g,PVPP 0.252 g,矫味剂0.301 g,润滑剂0.06 g。制备的清降口腔崩解片酸甜适口,无沙砾感,崩解时限48.8 s,总评分平均值4.48与预测值4.51的偏差很小。结论:模糊综合评价法可同时评价清降口腔崩解片的主、客观指标,所得结果准确性高、重复性好。     

Inference on cancer screening exam accuracy using population‐level administrative data

This paper develops a model for cancer screening and cancer incidence data, accommodating the partially unobserved disease status, clustered data structures, general covariate effects, and dependence between exams. The true unobserved cancer and detection status of screening participants are treated as latent variables, and a Markov Chain Monte Carlo algorithm is used to estimate the Bayesian posterior distributions of the diagnostic error rates and disease prevalence. We show how the Bayesian approach can be used to draw inferences about screening exam properties and disease prevalence while allowing for the possibility of conditional dependence between two exams. The techniques are applied to the estimation of the diagnostic accuracy of mammography and clinical breast examination using data from the Ontario Breast Screening Program in Canada. Copyright © 2015 John Wiley & Sons, Ltd.     

A Bayesian approach to sequential meta‐analysis

As evidence accumulates within a meta‐analysis, it is desirable to determine when the results could be considered conclusive to guide systematic review updates and future trial designs. Adapting sequential testing methodology from clinical trials for application to pooled meta‐analytic effect size estimates appears well suited for this objective. In this paper, we describe a Bayesian sequential meta‐analysis method, in which an informative heterogeneity prior is employed and stopping rule criteria are applied directly to the posterior distribution for the treatment effect parameter. Using simulation studies, we examine how well this approach performs under different parameter combinations by monitoring the proportion of sequential meta‐analyses that reach incorrect conclusions (to yield error rates), the number of studies required to reach conclusion, and the resulting parameter estimates. By adjusting the stopping rule thresholds, the overall error rates can be controlled within the target levels and are no higher than those of alternative frequentist and semi‐Bayes methods for the majority of the simulation scenarios. To illustrate the potential application of this method, we consider two contrasting meta‐analyses using data from the Cochrane Library and compare the results of employing different sequential methods while examining the effect of the heterogeneity prior in the proposed Bayesian approach. Copyright © 2016 John Wiley & Sons, Ltd.     

Profitability analysis of a femtosecond laser system for cataract surgery using a fuzzy logic approach

AIM: To define the financial and management conditions required to introduce a femtosecond laser system for cataract surgery in a clinic using a fuzzy logic approach. METHODS: In the simulation performed in the current study, the costs associated to the acquisition and use of a commercially available femtosecond laser platform for cataract surgery (VICTUS, TECHNOLAS Perfect Vision GmbH, Bausch & Lomb, Munich, Germany) during a period of 5y were considered. A sensitivity analysis was performed considering such costs and the countable amortization of the system during this 5y period. Furthermore, a fuzzy logic analysis was used to obtain an estimation of the money income associated to each femtosecond laser-assisted cataract surgery (G). RESULTS: According to the sensitivity analysis, the femtosecond laser system under evaluation can be profitable if 1400 cataract surgeries are performed per year and if each surgery can be invoiced more than $500. In contrast, the fuzzy logic analysis confirmed that the patient had to pay more per surgery, between $661.8 and $667.4 per surgery, without considering the cost of the intraocular lens (IOL). CONCLUSION: A profitability of femtosecond laser systems for cataract surgery can be obtained after a detailed financial analysis, especially in those centers with large volumes of patients. The cost of the surgery for patients should be adapted to the real flow of patients with the ability of paying a reasonable range of cost.     

改进的熵最小方法用于MRI偏差场的校正

灰度不均匀性分布是磁共振成像中经常发生的一种病态混扰,它给医生读片诊断和磁共振图像(MRI)计算机自动化处理带来很大困难。针对偏差场平滑、渐变的特性,本研究提出了一种改进的基于图像信息熵最小化的自动校正算法.该方法是一种全自动的无需先验知识的校正方法。在实验过程中,采用模糊C-均值聚类算法来提取反映偏差场变化趋势的同类特征点;通过二次曲面拟合特征点曲面的方法,提取初始化曲面参数;应用具有学习能力的粒子群寻优算法提高信息熵搜索的优化速度。最后,在对Brain-Web数据库仿真MRI和实际采集到的MRI校正中,获得了更适合人眼观看的校正图片,为临床诊断提供了准确可信的图像数据。     

一种基于概率配分和最大模糊熵的CT图像分割方法

为了从CT图像中提取到多个组织的解剖特征,克服运算速度快与运算结果不稳定的矛盾,提出了一种基于概率分布和模糊熵的CT图像分割方法。为了找到分割灰度图象的最佳阈值,根据模糊聚类和概率配分之间的关系,以及模糊熵有最大值的必要条件,从而得到各类的概率配分,因此在搜索阈值组合时,先搜索满足各类概率配分的阈值,然后从这些阈值中搜索使模糊熵最大的阈值。实验结果表明该方法能很好地完成CT图象的分割。此算法运算速度较快;与用遗传算法、模拟退火算法相比较,运算结果稳定,分割更准确。