HCV高变区合成多肽的抗原性研究

目的：通过计算机同源模建，寻找丙型肝炎病毒高变区（HCV HVR1）中保护性多肽抗原表位。方法：计算机同源模建，预测多肽的抗原性，然后用淋巴细胞转化的方法验证其抗原性，结果：同源模建与实验结果一致，多肽抗原性有待进一步的提高。结论：同源模建是一种高效寻找具有保护性抗原多肽的经济快速方法。     

丙型肝炎高变区多肽的同源模建与抗原性研究

目的通过计算机同源模建,寻找丙型肝炎高变区中保护性多肽抗原表位.方法用计算机同源模建预测多肽的抗原性,然后用淋巴细胞转化试验验证其抗原性.结果同源模建与实验结果相一致.结论同源模建是一种高效寻找具有保护性的抗原多肽的经济快速的方法.     

人体运动的生物力学建模与计算机仿真进展

人体运动的生物力学建模与仿真,广泛应用于阐明不同运动的生理机理、探讨运动损伤机制、提高运动员运动成绩和降低损伤等诸多研究领域。他涉及人体骨骼、关节、肌肉和神经等组织的生理、解剖和力学特征的数学建模。利用数学模型,可以采用相关算法求解运动过程中不同肌肉的收缩力,同时还可通过计算机软件进行仿真实验并将仿真结果可视化。本文对人体运动的生物力学建模与仿真及其应用进行了综述。     

心血管循环系统建模和仿真研究中的功率键合图方法

建立一种心血管循环系统的计算机仿真模型,即描述心血管循环系统内血流动力学变量变化规律的状态方程。该仿真模型可用于生理医学研究及医学辅助教学．文中提出的功率键合图建模方法能够较好地完成对人体循环系统建立仿真模型的工作,并对一个简化的循环系统生理模型进行了计算机仿真研究,仿真结果表明,功率键合图建模方法在生理医学的系统仿真中具有良好的可行性和有效性,作为一种易于理解和统一的建模方法在生理系统仿真领域有     

试论生物医学数学建模中的若干问题

生物医学中的数学建模已受到研究人员的普遍关注。然而,由于生物医学中研究对象与研究方法有着自身的工作特点,它和传统的物理工程系统相比有较大的差异,如对这些特点没有明晰的认识,对于要想利用数学模型研究生伞现象的土物医学工作者和数理工作者的工作都会有所妨碍。人们已就数学方法在生物医学中的作用、生物医学数学模型的构造、运用的原则与方法作过方法学的探讨。本文拟着重从方法论的角度论述生物医学数学建模中的若干问题。     

Computer simulations of lung airway structures using data-driven surface modeling techniques

Knowledge of human lung morphology is a subject critical to many areas of medicine. The visualization of lung structures naturally lends itself to computer graphics modeling due to the large number of airways involved and the complexities of the branching systems. In this study, a method of generating three-dimensional computer simulations of human lung airway networks using data-driven, surface modeling techniques is presented. By simulating the tubular airway structures and realistic bifurcation shapes, anatomically accurate representations of human lungs are obtained. These computer models are designed for use in computational fluid dynamic applications and particle trajectory analyses, and to be complimentary to medical imaging (gamma scintigraphy) protocols.     

数字仿真技术在手术治疗骶髂关节损伤中的相关研究

目的:研究计算机仿真技术对于骶髂关节损伤进行闭合手术治疗的临床指导作用。方法:选12个骶髂关节,行平片和螺旋CT扫描后进行三维重建及仿真建模,建立起具有个性化伤情的数字化仿真系统,分析损伤的情况和周围骨性结构的毗邻,并利用软件MEDCAD工具模拟出置入的“内固定”,进行仿真手术模拟;评价不同进针点、进针角度及进针深度的生物力学和解剖学效果;并按照模拟手术中测得的个体化数据在尸体标本上进行模拟手术及临床解剖学对比验证。结果:仿真模拟手术中测得的数据通过尸体标本模拟手术的临床解剖学验证,12侧骶髂关节均未发现进入椎管或穿越骶孔等现象。结论:可利用计算机仿真技术和临床手术治疗相结合,使骶髂关节损伤情况得到充分显示,并可根据模拟手术制定最佳的手术方案;数字化仿真技术可以很好的指导临床骶髂关节损伤的手术治疗。     

Expression library immunization confers protection against Mycobacterium avium subsp. paratuberculosis infection

Currently, paratuberculosis vaccines are comprised of crude whole-cell preparations of Mycobacterium avium subsp. paratuberculosis. Although effective in reducing clinical disease and fecal shedding, these vaccines have severe disadvantages as well, including seroconversion of vaccinated animals and granulomatous lesions at the site of vaccination. DNA vaccines can offer an alternative approach that may be safer and elicit more protective responses. In an effort to identify protective M. avium subsp. paratuberculosis sequences, a genomic DNA expression library was generated and subdivided into pools of clones (approximately 1,500 clones/pool). The clone pools were evaluated to determine DNA vaccine efficacy by immunizing mice via gene gun delivery and challenging them with live, virulent M. avium subsp. paratuberculosis. Four clone pools resulted in a significant reduction in the amount of M. avium subsp. paratuberculosis recovered from mouse tissues compared to mice immunized with other clone pools and nonvaccinated, infected control mice. One of the protective clone pools was further partitioned into 10 clone arrays of 108 clones each, and four clone arrays provided significant protection from both spleen and mesenteric lymph node colonization by M. avium subsp. paratuberculosis. The nucleotide sequence of each clone present in the protective pools was determined, and coding region functions were predicted by computer analysis. Comparison of the protective clone array sequences implicated 26 antigens that may be responsible for protection in mice. This study is the first study to demonstrate protection against M. avium subsp. paratuberculosis infection with expression library immunization.     

Humanization of an anti-human TNF-alpha antibody by variable region resurfacing with the aid of molecular modeling

The murine monoclonal antibody Z12 is of therapeutic interest for its neutralizing biological activity against human tumor necrosis factor-alpha (hTNF-alpha). We attempted to humanize Z12 with variable domain resurfacing guided by computer modeling. First, the genes of heavy and light chain variable region (VH, VL) of Z12 were cloned and the whole three-dimensional structure of Fv fragment was constructed by using homology-based modeling and molecular docking methods. Then the complex model of Fv interacting with hTNF-alpha whose crystal structure derived from PDB database was gained with computer-guided docking program. Based on this model, a humanized version was designed. The humanized Fab antibody was constructed, expressed and purified in the pComb3H vector system and it showed unaltered binding affinity to the antigen as determined by ELISA and atomic force microscopy (AFM). The method described here can be used to humanize other anti-hTNF-alpha antibodies.     

Risky and Protective Contexts and Exposure to Violence in Urban African American Young Adolescents

Contexts of risk for and protection from exposure to violence were identified and the relation of exposure to violence to delinquent behaviors and symptoms of trauma was examined. Using the Experience Sampling Method (ESM), the immediate daily experience of risky and protective contexts was examined. One hundred sixty-seven African American 6th-, 7th-, and 8th-grade children from urban neighborhoods carried watches and booklets for 1 week. Structural equation modeling supported the hypotheses that more time in risky contexts and less time in protective contexts was related to more exposure to violence. Exposure to violence partially mediated the relation of time in protective and risky contexts to delinquent behaviors, assessed with the Juvenile Delinquency Scale and the Child Behavior Checklist, and distress levels, assessed by a posttraumatic stress disorder (PTSD) score.     

AR模型在远程心电诊断中的应用

在远程心电诊断中 ,计算机辅助ECG诊断通常是在接收到ECG信号、进而解压重建后进行的 ,这样便造成诊断工作的延误。本研究提出了一种基于AR模型的ECG直接分类方法 ,利用AR模型系数及其建模误差作为特征对ECG信号进行压缩 ,并采用非线性二次判别函数形式进行特征分类。通过对MIT BIH标准数据库中的NSR、APC、PVC、SVT、VT和VF各 2 0 0个样本信号进行测试 ,获得了 93.5 %～ 97.86 %的分类精度。该方法的特点是 :诊断迅速方便 ,能同时对多类ECG信号进行有效分类 ,特别适于远程诊断应用     

基于软件OpenSim的人体运动建模理论及其应用领域概述

红外捕捉系统、高速摄像、平面摄影、表面肌电测试等现行实验室测试手段不能显示人体运动时肌肉产生肌力的具体信息以及准确阐释神经-肌肉协调机制。因此,计算机模拟与仿真应运而生。目前,国内用来进行人体动作仿真的软件主要有Life MOD、Any Body、ANSYS等,这些软件有其自身的缺陷,如肌肉控制不够精确、价钱昂贵等。为了更好解决肌肉模拟问题,斯坦福大学团队研发了一款免费软件Open Sim,它是基于C++和JAVA语言开发的一款应用于肌肉模型开发、模拟仿真与分析神经肌肉系统的开放性软件。以计算机建模与数学理论推导为基础,对Open Sim建模理论和步骤进行详细介绍,为国内从事运动生物力学研究学者提供一些理论参考;同时,探讨未来利用Open Sim建模仿真研究的主要方向,例如通过Open Sim的模拟研究可以探求偏瘫步态、帕金森步态等异常步态的神经-肌肉机制,为异常步态康复手段的改进和完善提供依据。     

The Effects of the Safe-sun Program on Patrons' and Lifeguards' Skin Cancer Risk-reduction Behaviors at Swimming Pools

The 'Safe Sun' program had the goal of increasing patrons' and lifeguards' skin-protective behaviors and involved informational, prompting, feedback and goal-setting and incentive components coupled with pool lifeguards modeling protective behaviors such as wearing shirts, hats and sunglasses or staying in shaded areas. During two phases of a project involving 27 pools, it was found that while the program increased patrons' and lifeguards' protective behaviors, the largest changes were found at one pool where lifeguards were required to participate in the program. Patrons' protective behaviors at this pool increased from 30.7 percent to 52 percent, and lifeguards' protective behaviors increased from 40.8 percent to 95.7 percent. Social marketing, environmental change and institutionalization processes are needed to make skin-cancer prevention programs more effective.     

Feasibility of Using a Computer Modeling Approach to Study SUI Induced by Landing a Jump

Stress urinary incontinence (SUI) occurs due to anatomic and/or neurologic factors involving connective tissues, muscles and nerves. Although SUI is more common in post-menopausal and multiparous women, studies have also shown a high prevalence of SUI in young, physically fit female athletes. With a goal toward dynamic subject-specific mechanical characterization of the interaction between anatomical structures during physical activities that elicit SUI in females during physical or daily activities, a computer aided design (CAD)-based computer model of the female pelvis has been developed to test the feasibility of the computer modeling approach in understanding the measurable differences between stress-continent and stress-incontinent women. In the present study, a fluid–structure interaction analysis was conducted by using the finite element (FE) analysis technique based on the CAD-based computer model of the female pelvis to investigate the urine leakage in females during jumping. To the best of our knowledge, this is the first application of a fluid–structure interaction FE analysis approach in understanding the mechanisms of SUI in females. Through a series of computer simulations, the effects of varying impact forces determined by jumping height and bladder volume were investigated. The dynamic computer simulation results revealed that jumping heights have a significant influence on the volume of urine leakage caused by the landing impact of jumping. Bladder volume did not have a significant influence on leakage when the jumping heights were smaller than 1 ft, which indicates that normal walking (corresponds to a jumping height smaller than 0.1 ft) is not the primary cause of urine leakage for healthy females. The computer simulation results also showed that the deformation difference between the anterior and posterior portion of the female pelvis causes opening of the urethra and resultant urine leakage. The present study demonstrates the feasibility of using a computer modeling approach to study female SUI during physical and daily activities.     

手指解剖结构的三维建模及临床意义

目的:应用计算机辅助模拟技术(CAD)建立手指解剖结构的三维模型.在计算机上实现手指解剖结构的三维演示.方法:根据手部解剖图谱及相关资料,应用3ds max的放样、多边形等算法建立三维模型.结果:应用上述方法成功地建立了手指解剖结构及指固有动脉逆行岛状瓣的三维模型.该模型可在电脑屏幕上自由旋转,隐藏不感兴趣结构.结论:应用三维建模软件进行手指解剖结构的三维演示是可行的,它有助于人们更好的理解和记忆解剖结构,进行手指手术设计.     

Biomorphometric analysis of human prostatic carcinoma by using three-dimensional computer models

Advances in the detection of carcinoma of the prostate during the last 15 years have accounted for a sharp increase and then an abrupt decrease in the incidence of the disease. A more recent decline in its mortality rates has been variously interpreted as either the success of early detection and improved treatment or lead-time bias. The recently reported Prostate Cancer Prevention Trial had an overall detection rate that approached the 30%-40% prevalence rates reported in autopsy series in which men died of other causes. However, the prognostic information that can be obtained from prostate cancer found on biopsy is limited. Three-dimensional computer modeling is one technique that allows multiple studies on "immortal" prostates to test methods of biopsy sampling accuracy and to assist in the determination of the disease's severity. Computer modeling can assess detection rates and assesses tumor multifocality and heterogeneity. It can provide a more accurate representation of tumor volume, aiding in therapeutic decision making, and can assess sampling errors of various biopsy methods. It has been shown to be superior to wire-frame technique by immortalizing the original shape and dimensions of the surgically excised prostate gland. Moreover, our 3-dimensional computer modeling system improves upon other systems: It is more than a simple extension of the planimetric technique, and it is able to demarcate clearly the boundaries of Gleason grades just 1 grade apart.     

Community involvement and victimization at school: an analysis through family,personal and social adjustment

The present study analyzes the impact of adolescents' community involvement on victimization by peers at school through various indicators of family, personal and social adjustment (openness of communication with mother and father, life satisfaction, social self‐esteem, and loneliness). Participating in the project were 565 adolescents aged 11 to 18 (51% male) drawn from secondary schools in Spain. Statistical analyses were conducted using bivariate correlations, the t test and structural equation modeling. Results indicated an indirect and protective influence of community involvement, openness of communication with parents and life satisfaction on victimization by peers. There was also a direct protective effect of social self‐esteem and a direct risk effect of loneliness on victimization at school. Findings are discussed in light of the consideration that community involvement is a key factor in the promotion of other protective factors related to adolescent victimization at school. © 2009 Wiley Periodicals, Inc.     

介入器械放置与血流影响的仿真分析

心血管介入器械的使用越来越广泛,而综合考虑血流、器械和血管的作用情况,研究器械的放置和设计问题,有助于减少器械诱发的并发症,提高其使用的效果.本文以腔静脉滤器为例,采用计算机建模,有限体积法生成网格,通过计算流场来分析器械与血流的相互作用.结果表明介入器械的结构(如器械的支腿类型、附着方式)和放置对血管及血流有显著的影响,而器械的放置位置也可依据血管流场的情况来进行优化选择.     

Interactive computer simulations of knee-replacement surgery.

OBJECTIVE: Current surgical training programs in the United States are based on an apprenticeship model. This model is outdated because it does not provide conceptual scaffolding, promote collaborative learning, or offer constructive reinforcement. Our objective was to create a more useful approach by preparing students and residents for operative cases using interactive computer simulations of surgery. Total-knee-replacement surgery (TKR) is an ideal procedure to model on the computer because there is a systematic protocol for the procedure. Also, this protocol is difficult to learn by the apprenticeship model because of the multiple instruments that must be used in a specific order. We designed an interactive computer tutorial to teach medical students and residents how to perform knee-replacement surgery. We also aimed to reinforce the specific protocol of the operative procedure. Our final goal was to provide immediate, constructive feedback. DESCRIPTION: We created a computer tutorial by generating three-dimensional wire-frame models of the surgical instruments. Next, we applied a surface to the wire-frame models using three-dimensional modeling. Finally, the three-dimensional models were animated to simulate the motions of an actual TKR. The tutorial is a step-by-step tutorial that teaches and tests the correct sequence of steps in a TKR. The student or resident must select the correct instruments in the correct order. The learner is encouraged to learn the stepwise surgical protocol through repetitive use of the computer simulation. Constructive feedback is acquired through a grading system, which rates the student's or resident's ability to perform the task in the correct order. The grading system also accounts for the time required to perform the simulated procedure. We evaluated the efficacy of this teaching technique by testing medical students who learned by the computer simulation and those who learned by reading the surgical protocol manual. Both groups then performed TKR on manufactured bone models using real instruments. Their technique was graded with the standard protocol. The students who learned on the computer simulation performed the task in a shorter time and with fewer errors than the control group. They were also more engaged in the learning process. DISCUSSION: Surgical training programs generally lack a consistent approach to preoperative education related to surgical procedures. This interactive computer tutorial has allowed us to make a quantum leap in medical student and resident teaching in our orthopedic department because the students actually participate in the entire process. Our technique provides a linear, sequential method of skill acquisition and direct feedback, which is ideally suited for learning stepwise surgical protocols. Since our initial evaluation has shown the efficacy of this program, we have implemented this teaching tool into our orthopedic curriculum. Our plans for future work with this simulator include modeling procedures involving other anatomic areas of interest, such as the hip and shoulder.     

扶肾降浊方含药血清对肾小管间质损害大鼠成纤维细胞抗纤维化因子HGF和BMP-7的影响

目的:探讨扶肾降浊方对系膜增生性肾小球肾炎(Ms PGN)大鼠肾小管间质损害的疗效及机制。方法:采用扶肾降浊方水溶液灌胃Wistar大鼠常规制备含药血清,在Ms PGN动物模型的基础上,延长造模时间至20周,使其自然发展为肾小管间质损害模型,体外培养造模12、16和20周末大鼠间质成纤维细胞,采用real-time PCR和Western blotting法检测扶肾降浊方含药血清对病理状态间质成纤维细胞中抗纤维化因子肝细胞生长因子(HGF)、骨形态发生蛋白-7(BMP-7)mRNA及蛋白表达的影响。结果:病理状态间质成纤维细胞中抗纤维化因子HGF、BMP-7 mRNA和蛋白表达下调,扶肾降浊方含药血清随着给药周期的延长可部分逆转间质损害造成的上述mRNA和蛋白表达异常。结论:扶肾降浊方含药血清对Ms PGN大鼠间质成纤维细胞的保护作用可能与调节抗纤维化因子HGF、BMP-7 mRNA和蛋白表达有关。