Simultaneous genetic analysis of longitudinal means and covariance structure in the simplex model using twin data

A longitudinal model based on the simplex model is presented to analyze simultaneously means and covariance structure using univariate longitudinal twin data. The objective of the model is to decompose the mean trend into components which can be attributed to those genetic and environmental factors which give rise to phenotypic individual differences and a component of unknown constitution which does not involve individual differences. Illustrations are given using simulated data and repeatedly measured weight obtained in a sample of 82 female twin pairs on six occasions.     

Open mesh versus non-mesh repair of groin hernia meta-analysis of randomized trials leased on individual patient data

Abstract Background. The EU Hernia Trialists Collaboration was established to provide reliable evaluation of newer methods of groin hernia repair. It involved 70 investigators in 20 countries. Materials and methods. Twenty eligible trials (5016 participants) of open mesh vs. non-mesh groin hernia repair were identified. Meta-analysis was performed using raw individual patient data where possible. Results. Fewer hernia recurrences were reported after mesh repair. There were no clear differences between mesh and non-mesh groups in complications. Overall, those in the mesh groups had a shorter hospital stay, quicker return to usual activities and less frequent persisting pain, but individual trial results varied. Conclusions. The review provides strong evidence that open mesh repair is associated with a reduction in the risk of recurrence of between 50% and 75%. There is also some evidence of quicker recovery and of lower rates of persisting pain following open mesh repair. Electronic Publication     

云纹技术在断裂分析中的应用

改进了传统的云纹数据处理方法,提出用曲面拟合方法处理云纹数据,提高了计算机处理云纹数据的效率与质量。又提出用云纹法测量J积分的技术,可望解决实际工程构件的J积分测量问题。     

ROBUST GUARANTEED COST CONTROL OF UNCERTAIN NON-LINEAR ROBOTIC SYSTEM USING MIXED MINIMUM TIME AND QUADRATIC PERFORMANCE INDEX

To provide better transient performance in controlling robots, a mixed minimum time and quadratic performance index is used. For known and uncertain revolute robot manipulators a conventional optimal control and a robust guaranteed cost control are proposed respectively. Asymptotic stability is also discussed based on the Lyapunov direct method. The proposed robust control is continuous and requires no knowledge of the uncertain system except for bounding functions.     

Cross-calibration of liquid and solid QCT calibration standards: Corrections to the UCSF normative data

Quantitative computed tomography (QCT) has been shown to be a precise and sensitive method for evaluating spinal bone mineral density (BMD) and skeletal response to aging and therapy. Precise and accurate determination of BMD using QCT requires a calibration standard to compensate for and reduce the effects of beam-hardening artifacts and scanner drift. The first standards were based on dipotassium hydrogen phosphate (K₂HPO₄) solutions. Recently, several manufacturers have developed stable solid calibration standards based on calcium hydroxyapatite (CHA) in water-equivalent plastic. Due to differences in attenuating properties of the liquid and solid standards, the calibrated BMD values obtained with each system do not agree. In order to compare and interpret the results obtained on both systems, cross-calibration measurements were performed in phantoms and patients using the University of California San Francisco (UCSF) liquid standard and the Image Analysis (IA) solid standard on the UCSF GE 9800 CT scanner. From the phantom measurements, a highly linear relationship was found between the liquid- and solid-calibrated BMD values. No influence on the cross-calibration due to simulated variations in body size or vertebral fat content was seen, though a significant difference in the cross-calibration was observed between scans acquired at 80 and 140 kVp. From the patient measurements, a linear relationship between the liquid (UCSF) and solid (IA) calibrated values was derived for GE 9800 CT scanners at 80 kVp (IA=[1.15×UCSF]-7.32). The UCSF normative database for women and men obtained with the liquid standard was corrected for use with the solid standard. Proper procedures for cross-calibrating QCT measurements and the appropriate uses of normative data are discussed.     

针灸治疗慢性非特异性腰痛随机对照试验结局指标的现状研究

背景 针灸是治疗慢性非特异性腰痛(CNSLBP)的重要方法。随着研究的发展,大量针灸治疗CNSLBP的随机对照试验(RCT)已经发表,但由于在结局指标选择方面存在一定的问题,严重限制了高质量临床证据的产生。目的 评价针灸治疗CNSLBP RCT选用的结局指标情况,为针灸治疗CNSLBP相关研究提供参考依据。方法 系统检索4个中文数据库(中国知网、维普网、万方数据知识服务平台、中国生物医学文献服务系统)、3个英文数据库(PubMed、Embase、Cochrane Library)2017-01-01至2022-03-15发布的针灸治疗CNSLBP的文献,以及自建库以来至2022-03-15发表的非特异性腰痛(NSLBP)的核心结局指标集(COS)。对纳入的针灸治疗CNSLBP的文献基本特征进行分析,对文献的临床结局指标进行归类,对文献中的结局指标及《中医病证诊断疗效标准》的应用现状进行分析。分析NSLBP研究的COS现状,比较其与现有针灸治疗CNSLBP文献结局指标的异同。结果 本研究纳入的针灸治疗CNSLBP的49篇文献均为RCT,共包含4篇英文文献和45篇中文文献。共包含4 272...     

达格列净对2型糖尿病合并慢性心力衰竭患者微小RNA-423-5p的调控作用及心功能的影响研究

背景 糖尿病合并心力衰竭的患者数量庞大,达格列净作为新型降糖药物,目前已被指南推荐用于心力衰竭的治疗,但其改善心功能的作用机制还未完全明确。目的 研究达格列净对2型糖尿病（T2DM）合并慢性心力衰竭（CHF）患者血浆微小RNA-423-5p(miRNA-423-5p)表达的影响及其与心功能之间的相关性。方法 纳入2021-04-01至2021-11-30就诊于解放军第九六〇医院的T2DM合并CHF患者50例为研究对象,分为达格列净组（n=25）和对照组（n=25）,达格列净组给予达格列净10 mg/d,对照组给予其他降糖药物,余治疗原则相同,治疗6个月。另纳入同一时期于本院健康体检的心功能正常者为健康人群组（n=25）。通过数字病历系统收集患者的基本资料,包括年龄、性别、吸烟史、高血压史、血压水平、体质指数（BMI）、血脂、血糖、肌酐（Cr）、氨基末端脑钠肽前体（NT-proBNP）、丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）、纽约心脏病协会（NYHA）心功能分级、心脏彩超、合并用药情况,并留取血液标本进行miRNA-423-5p的检测。治疗4周进行门诊随访,收集患者心功...     

基于图像的微阵列生物芯片分析

利用生物芯片的高通量特性，系统地研究生物体基因和蛋白质表达及其相互作用，在最近十几年迅速发展。以图像为基础的生物芯片分析是生物芯片技术的重要组成部分，对其方法进行研究已成为当前的热点之一。目前很多针对生物芯片的分析方法不断涌现，这些方法涉及网格定位、靶点分割、数据提取和表达、几何校正、噪声消除等生物芯片分析子过程。本研究对以上各类分析方法进行了综述，分析了各类方法的不同应用，比较了多种算法的分析结果，并提出当前在生物芯片分析研究领域需要解决的关键问题。     

Comparing non-hierarchical models: Application to non-linear mixed effects modeling

There is no method available to compare the fit of two non-hierarchical non-linear mixed effects models, although the common practice is to select the model with the lower objective function. Bootstrapping the log-likelihood differences (LLDs) of non-hierarchical models and constructing a bootstrap confidence interval on the LLDs is proposed for comparing the goodness-of-fit of such models. This is illustrated with different parameterizations of clearance models for an anti-infective agent in a longitudinal pharmacokinetic study which are compared. Additive and exponential models of creatinine clearance as a predictor of clearance are used as examples.