衰老机制的思考

衰老原因和机制极为复杂,是一具有累积性、普遍性、渐进性、内生性和危害性的生命过程.衰老的本质是渐进性的功能减退,各种因素通过引起功能减退加速衰老,减慢功能损害则能延缓衰老.本文笔者认为:衰老机制是非特异性的;理论上,能引起功能减退的因素应能加速衰老.     

认知年老化和老年心理健康

认知功能和心理健康是健康老龄化的两个基本要素。认知功能随年老而加速减退,其机制的探讨表明,加工速度、工作记忆和执行功能在认知年老过程中均起重要的中介作用。大多数老年人的心理健康状况较好、生活满意度较高,其心态随年龄的增高而更趋于平静满足,但独居和绝对空巢老人的某些心理健康问题不容忽视。认知年老化过程和老年人的心理健康状况分别受诸多因素的影响,研究结果为延缓认知功能的年老减退和保持老年人的心理健康,以及实现健康老龄化和积极老龄化提供了有益的启示     

衰老与学习记忆

本文从行为和神经生物学方面重点讨论了动物和人的衰老对学习记忆的影响。大量实验证明,短时记忆和长时记忆都因衰老受到损害,并表现出明显地作业依赖性。乙酰胆碱能系统和去甲肾上腺素能系统对年龄性记忆能力衰减有重要作用。阿片样物质及其他神经递质的作用也不能排除在外。因此衰老引起记忆下降的机制和临床治疗都不能简单地只考虑某一种递质或活性物质的变化。     

人体衰老与社会活动功能的关系研究

介绍了社会功能的定义、特征、作用、理论机制及评估方法,概括了社会活动功能的影响因素及其与衰老的关系。诸多研究提示,生理、心理、生活方式、个人习惯、宗教、种族以及社会紧张状态等因素与社会活动功能有关。随着时序年龄增加,人体生理功能衰老的同时也伴随社会活动功能的降低,如组织能力、社会参与功能等。同时,社会活动功能也反作用于衰老,表现为社会活动功能良好者其衰老程度及老化速度更低,反之,则衰老更甚。总之,年龄与社会活动功能呈负相关,且两者相互作用。     

轻度认知功能障碍患者工作记忆中 脑电能量及皮质联络功能的变化特征

探讨轻度认知功能障碍患者（MCI）工作记忆状态下脑电能量及皮质联络功能的变化特征。被试为从社区选取的35名轻度认知功能障碍患者和34名健康志愿者。采用简单计算回忆方法,结果发现工作记忆加工过程中会引起4.0~18.0Hz范围内功率值的改变,且MCI组高于正常对照组;MCI患者在中央、顶、颞叶的半球间相干系数均显著高于正常对照组。研究结果提示MCI患者可能存在中央、顶、颞叶皮层的功能减退,工作记忆状态下通过代偿机制仍能维持加工的有效性     

亚临床甲状腺功能减退与冠状动脉粥样硬化性心脏病

对冠心病高危因素积极地预防及治疗,可降低冠心病的患病率和病死率。已经得到公认的临床甲状腺功能减退通过引起代谢及血流动力学紊乱而参与了冠状动脉粥样硬化的发生与发展。目前,国内外许多临床研究显示亚临床甲状腺功能减退通过多种途径参与冠心病的发生和发展,是冠心病的重要危险因素之一。     

亚临床甲状腺功能减退与冠状动脉粥样硬化性心脏病

对冠心病高危因素积极地预防及治疗,可降低冠心痛的患病率和病死率.已经得到公认的临床甲状腺功能减退通过引起代谢及血流动力学紊乱而参与了冠状动脉粥样硬化的发生与发展.目前,国内外许多临床研究显示亚临床甲状腺功能减退通过多种途径参与冠心病的发生和发展,是冠心病的重要危险因素之一.     

几种金属元素与老年痴呆症

有一些金属元素参与多种生命活动过程,这是身体必要的成份．另一些金属元素（尤其是重金属）则对身体有害。因此,金属元素在营养、生理、病理等方面的意义已日益引起重视．目前,人们已将某些神经－精神疾病的病因和发病机制与体内一些金属元素的含量水平对应起来进行了多方面的研究。本文简要介绍了钙、铝、锌等若干种金属元素与衰老性脑功能障碍（尤其是ＡＩｚｈｅｉｍｅｒ型痴呆症）相关性及其机理的研究概况。     

足月胎儿对声音刺激反应的探讨

通过观察声音刺激引起胎儿产生的胎动和胎心率反应,初步探讨声音刺激能否引起胎儿的感觉和相应的反射机制。选择正常足月孕妇94例,分别接受95、100、105、110、115分贝的声音刺激,观察胎儿的胎动和胎心率反应。95分贝声音能引起胎心率轻度下降且不引起胎动,而声强在100分贝以上的声音刺激能引起胎心率加速并伴有胎动,提示95分贝声音可以引起胎儿的定向反射,和胎儿的选择性的注意有关;而100~115分贝的声音能引起胎儿的防卫反应。婴儿与生俱来的无条件反射在胎儿期就已存在。     

心理因素与心脏衰老关系之探索

当前 ,人口结构正逐步向老龄化发展 ,对人体衰老机制的探讨因而日益受到重视。心脏是生命的重要器官 ,是伴随增龄衰老表现突出的器官之一。近年来 ,随着医学模式从生物医学模式向生物心理社会模式的转换及心身医学的发展 ,心理因素与某些心脏疾病如冠心病、高血压的关系已得到公认。心理因素对心脏衰老的影响也引起了研究者的关注。心血管系统随着增龄也会发生衰老改变 ,主要有以下几方面 :(1)主动脉进行性扩张和延长 ,管壁僵硬度增加。这是由于管壁弹性组织减少 ,胶原数量增多造成的。超声心动图表现为主动脉增宽 ,运动幅度下降。 (2 )左室…     

Proverb interpretation changes in aging

Recent investigations have emphasized the involvement of fronto-subcortical networks to proverb comprehension. Although the prefrontal cortex is thought to be affected by normal aging, relatively little work has been carried out to investigate potential effects of aging on proverb comprehension. In the present investigation participants in three age groups were assessed on a proverb comprehension task and a range of executive function tasks. The older group showed impairment in selecting correct interpretations from alternatives. They also showed executive function deficits, as reflected by reduced working memory and deficient set shifting and inhibition abilities. The findings of the present investigation showed proverb comprehension deficits in normal aging which appeared to be related to reduced executive skills.     

童年贫困与晚年认知老化：加速还是延缓?

童年贫困与晚年认知老化的关系尚存争议。有的研究表明, 童年贫困会加速个体的认知老化, 但是也有研究发现童年贫困会延缓个体的认知老化, 这与社会流动性起到的调节作用有关。对于童年贫困个体, 低稳定或者社会经济地位的向下流动(即长期贫困)会使逆境产生的消极影响不断累积, 从而加速个体的认知老化; 而心理韧性高的童年贫困个体, 可能会促使社会经济地位向上流动, 这会增加个体的认知储备, 并提升特定认知能力, 进而延缓认知老化。今后该领域的研究应该探讨童年主观贫困与认知老化之间的关系以及童年贫困对不同认知能力老化的影响, 也应关注童年贫困与晚年认知老化关系研究中的幸存者偏差效应。     

Modeling memory decline in older adults: the importance of preclinical dementia, attrition, and chronological age

This longitudinal study examined memory loss in a sample of 391 initially nondemented older adults. Analyses decomposed observed memory loss into decline associated with preclinical dementia, study attrition, terminal decline, and chronological age. Measuring memory as a function of only chronological age failed to provide an adequate representation of cognitive change. Disease progression accounted for virtually all of the memory loss in the 25% of the sample that developed diagnosable dementia. In the remainder of the sample, both chronological age and study attrition contributed to observed memory loss. These results suggest that much of memory loss in aging adults may be attributable to the progression of preclinical dementia and other nonnormative aging processes that are not captured by chronological age.     

汉语普通话声调T2-T4范畴化感知的老化效应

本研究考察了50~80岁说普通话的中老年人对普通话声调T2—T4的范畴化感知表现,探究影响声调范畴化感知老化的因素。采用经典范畴感知范式。结果显示,(1)中老年组所有年龄段(50~60岁、60~70岁、70~80岁)的范畴边界宽度都显著大于年轻组,但中老年组间差异不显著。(2)中老年人范畴边界宽度与记忆广度测试得分呈显著负相关,而与年龄的相关性不显著。(3)和年轻组相比,中老年组范畴内识别函数的斜率差异显著,而范畴间差异不显著。结果表明,中老年人声调感知范畴化程度下降,音系层面的加工能力发生衰退,记忆广度的衰退与声调范畴化感知老年化之间存在关联。此外,50到80岁间,年龄不会直接影响声调感知范畴化程度。     

基因-大脑-行为框架下的抑制控制与老化

抑制控制能力是认知功能的重要成分。神经影像研究表明, 老年人抑制控制能力改变与前额叶皮层萎缩、神经元丧失有着密切关系, 抑制过程中前额叶需要以更高水平的激活达到代偿目的。遗传学研究表明, 抑制控制相关认知老化具有个体差异性, 大脑结构功能对个体差异的作用会出现衰退, 而遗传变异作用逐渐增加, 并使之成为认知老化个体差异性的主要原因之一。未来研究应利用遗传影像学, 结合影像学和遗传学优势, 在基因、大脑和行为框架下探索抑制控制与老化。     

Phase transformation of Cu precipitate in Fe–Cu alloy studied using self-guided molecular dynamics

The self-guided molecular dynamics (SGMD) method, which can enhance the conformational sampling efficiency in MD simulations, was applied in investigating the phase transformation of Cu precipitate in α-iron that took place during thermal aging. It was shown that the SGMD method can accelerate calculating the bcc to 9R structure transformation of a small precipitate (even 4.0 nm in size), enabling the transformation without introducing any excess vacancies. The size dependence of the transformation also agreed with that seen in previous experimental studies.     

The nonconvergence of factals: A nonmetric common factor analysis

FACTALS is a nonmetric common factor analysis model for multivariate data whose variables may be nominal, ordinal or interval. In FACTALS an Alternating Least Squares algorithm is utilized which is claimed to be monotonically convergent.In this paper it is shown that this algorithm is based upon an erroneous assumption, namely that the least squares loss function (which is in this case a nonscale free loss function) can be transformed into a scalefree loss function. A consequence of this is that monotonical convergence of the algorithm can not be guaranteed.     

Coping With Losses and Past Trauma In Old Age: The Separation-Individuation Perspective

Abstract

Old age is a stage in life in which numerous changes associated with loss can be expected to occur in major life domains. Deterioration of health; retirement; relocation; occupational and financial loss; loss of social roles, identity, status, and support; and the loss of spouse and significant others (siblings, friends) pose an ongoing threat to everyday functioning, forcing the individual to adapt. Thus, effective functioning in daily life represents a major developmental task for the aging (Bakes & Carstensen, 1996; Marsiske, Lang, Bakes, & Bakes, 1995). There is marked variability in adjustment among the elderly, and despite the numerous losses associated with aging, many elderly people are well adjusted and report experiencing high levels of well-being (George & Clipp, 1991;Wetle, 1990).     

Cognition through the lifespan: mechanisms of change

Cognitive abilities rise steeply from infancy to young adulthood and then are either maintained or decline to old age, depending on the specific ability. This pattern suggests corresponding continuities of mechanism and process, but it is striking that the fields of cognitive development and cognitive aging make little contact with each other's methods and theories. In this review we examine reasons for this cultural separation, and show how recent findings from both areas fit a framework couched in terms of cognitive representation and control. These two broad factors have very different lifespan trajectories; consideration of their relative growth and decline makes it clear that cognitive aging is not simply 'development in reverse'. This framework is offered in light of recent interest in finding greater continuity throughout the lifespan and creating a more comprehensive explanation of cognitive function and cognitive change.     

老年夫妻的老化刻板印象对死亡焦虑的行动者效应和对象效应

目的：考察老年人的老化刻板印象对自身及配偶的死亡焦虑的影响。方法：145对老年夫妻完成老化印象量表和死亡焦虑量表,并运用行动者-对象互依模型进行数据分析。结果：（1）老化刻板印象和死亡焦虑在夫妻内部分别具有一致性;（2）老化刻板印象对自身死亡焦虑的行动者效应显著;（3）丈夫的积极老化刻板印象对妻子死亡焦虑的对象效应显著,妻子的消极老化刻板印象对丈夫死亡焦虑的对象效应显著。结论：老年人的老化刻板印象不仅影响自身而且影响配偶的死亡焦虑,但夫妻之间的影响存在性别差异。