An atomistic modelling and statistical analysis study of crack–void interaction in Aluminum

The interaction between a brittle crack and pre-existing void in front of the crack tip was studied in the realm of molecular dynamics simulations at the nanoscale in face centred cubic Al within the framework of embedded-atom method. The results provide corroborative evidence of the fact that presence of a void in front of a running crack deters further crack growth. By performing an extensive series of simulations with different void sizes and crack-void distances coupled with statistical analysis, it has been found that (1) major role of voids is to decrease the fracture stress with increasing void size, in addition to slight increase in strain at which the crack growth occurs and the consequent strain to fracture, (2) fracture stress for a constant void size follows a sinusoidal distribution by varying the crack-void distance and (3) it is the void size that is most crucial in dictating the fracture properties of the material, rather than the void placement.     

Reminiscence functions over time: consistency of self functions and variation of prosocial functions

The current study examines the temporal stability of the tripartite model of reminiscence functions in which eight separate reminiscence functions map onto three second-order factors which contribute significantly to measurement of an overarching reminiscence latent construct. We collected online responses from 411 adults 50+ years of age. Confirmatory factor analytic models were computed at three points of data collection over 16 months. Invariance analyses were next undertaken to simultaneously compare the measurement properties to assess within-person stability of reminiscence functions over time. The tripartite structure of reminiscence functions was replicated at each point of data collection. As hypothesised, self-positive and self-negative functions are consistent across points of data collection, whereas prosocial functions vary over time. The temporal stability of the self functions may be attributed to enduring characteristics of the individual such as personality traits and life attitudes, as well as their solitary nature. Previous research indicates that consistency of self-positive reminiscence functions has ensuing benefits for physical health and psychological well-being; the opposite is true for self-negative functions. The temporal variation of prosocial functions may be due to the varying availability of others to share memories and their responsiveness to the emotional context.     

药价“虚高”:成因、结果分析与对策探讨

药品价格“虚高”已成为近年来药品市场中的一个突出问题。通过考量药价“虚高”的成因,并从实证的角度分析药价“虚高”的结果———“有效需求人数”和“消费者剩余”的减少,提出一些建议。     

Scientific Peer Review: A Case Study From Local And Global Analyses.

The dialog between Staddon (2001, 2004) and Baum (2004) raises general questions about the nature of scientific peer review. Their dialog displays effects on peer review of differences of opinion about the relative merits of local and global analyses. Baum (1995, 1997, 2001, 2002) favors global analyses as a paradigm different, newer, and better than the local, dynamic, real‐time approach that plays a significant role in Staddon (2001). According to the Kuhnian perspective (Kuhn, 1996) Baum advocates, we can better understand his review of Staddon (2001) by considering the implications for it of his commitment to the idea that a global analysis is a superior scientific paradigm. This commentary examines some characteristics of local and global analyses, as well as some of their possible implications for peer review in the context of a reviewer's belief in the Kuhnian idea of incommensurability: According to this idea, a reviewer who either is, or who believes he is, from one paradigm is unlikely, for better or worse, to understand or perhaps even tolerate work from a different paradigm. It is recommended that a process be developed to encourage “truth in peer reviewing” to reduce possible conflicts of interest embedded in the current conception of scientific peer review.     

结核病诊治进展与科技革命

现代科技革命极大地促进了结核病各方面的发展.微生物学和免疫学的发展,揭示了结核病的病因、发病机制、病理生理的本质,分子生物学技术使结核病的基础研究不仅停留在器官、细胞水平,而是深入到蛋白质、核酸、基因的水平;基因治疗的方法可望从根本上治疗结核病.高新技术的产物如X线照片、电子计算机断层扫描、纤维支气管镜检查和新药的出现等极大地提高了临床诊治的能力.借助于各种先进的医疗设备而进行精确的诊断,基因治疗将成为一种崭新的治疗手段.     

反社会行为潜在遗传因素的全基因组关联分析

反社会行为是一种受基因和环境共同影响的复杂性行为, 但单个基因如单胺氧化酶基因(MAOA)、5-羟色胺转运体启动因子基因(5-HTT)、儿茶酚-o-甲基转移酶(COMT)基因的影响并不能全面解释其产生的分子遗传机制。来自分子遗传学研究取向的方法—— 全基因组关联分析(genome-wide association study, GWAS), 把人类基因组中数以百万计的单核苷酸(SNPs)和复制数变异(CNVs)作为遗传标记, 在全基因组层面上, 开展多中心、大样本的关联研究, 经过反复验证来发现与外在表型相关的基因位点, 为进一步了解反社会行为复杂分子遗传机制提供了重要的线索。未来的研究应该通过科学的实验设计将精确的基因分型技术与心理、环境因素相结合, 实现对复杂性行为或特质的基因-心理-环境模型的成因性分析。     

Genetics Education for Health Professionals: Strategies and Outcomes from a National Initiative in the United Kingdom

The National Health Service (NHS) National Genetics Education and Development Centre was established by the Department of Health in 2004 to help drive and co-ordinate genetics education for health professionals working outside specialist genetic services. This paper reviews the experiences and lessons learned to date. At the outset, it was clear that understanding the learning ethos, preferred delivery methods and attitudes towards genetics of different NHS healthcare groups was vital. We collected evidence by undertaking needs assessments with educators, practitioners and patients. We have determined the genetics knowledge, skills and attitudes which they said were needed and translated these into learning outcomes and workforce competences in a continuum of education. Beginning with core concepts introduced (and examined) pre-registration, the continuum continues with development of concepts post-registration as appropriate for role, leading to practical application and assessment of competences in the workplace. These are supported by a portfolio of resources which draw heavily on patient based scenarios to demonstrate to staff that genetics is relevant to their work, and to convince educators and policy makers that genetic education is likely to result in real clinical benefit. A long term educational policy, inclusive of learners, educationalists and their institutions must be evidence based, flexible and responsive to changes in workforce structure, provision of clinical services and conceptual and financial commitments to education. The engagement of national policy, regulatory and professional bodies is vital ().     

精子介导转基因技术的进展与争论

随着生物医学的不断发展,精子介导转基因技术正成为有希望的转基因方法。与其他基因转移方法相比,精子介导具有简单、高效、低廉、安全的特点。我们探讨精子结合外源DNA和DNA内化的分子模型,介绍精子介导转基因技术的改进方法,并指出存在的问题和伦理学争论,旨在推动该技术在生物技术领域的进一步发展。     

肿瘤分子生物学行为与其影像表现关系的探讨

肿瘤基因表达与其影像表现有一定的相关性,为我们用无创的影像学方法显示肿瘤的生物学特征提供了可能。探寻肿瘤分子生物学特性与其影像表现的内在联系,以期对肿瘤浸润和转移做出正确的诊断,从而为临床选择治疗方案、判断疗效和评估预后等提供更多、更有价值的信息。     

Between-measure consistency in social-skills assessment

The purpose of the present study was to assess the between-measure consistency of general and specific social-skills assessment strategies. Nineteen mentally retarded adults were assessed using both common and newly devised measures of social skills: (1) specific (molecular) behavior ratings from role-play assessments, (2) general (molar) ratings based on the role plays, staff (3) molar and (4) molecular predictions of client social skills use in the described role-play situations, (5) peer sociometric ratings, and molecular in vivoobservations conducted in (6) cafeteria and (7) party settings. For all molecular measures, the subjects were assessed on eye contact, response relevance, response latency, voice volume, and appropriate affect, which allowed for direct comparisons to be made between each of these assessment modalities. In addition, the role-play assessment was conducted under two distinct conditions to determine whether role-play performance varied between standard and reinforced administrations; however, multivariate analyses (MANOVA) revealed no differences between the two assessments. Correlations between the molar and the molecular measures suggested a substantial overlap between the measures, with staff ratings having the highest consistency with the other measures. Furthermore, MANOVAs calculated between role-play ratings and those of staff revealed little difference between the two. The limitations on and practical significance of these findings are discussed.