Molecular inflammation hypothesis of aging based on the anti-aging mechanism of calorie restriction

Accumulating evidence strongly suggests that oxidative stress underlies aging processes. Research provides consistent evidence that calorie restriction (CR) reduces age-related oxidative stress and has anti-inflammatory properties. However, information is lacking on the molecular mechanism that would better define the interrelation of reactive oxygen species and nitrogen species and the pro-inflammatory states of the aging process. In this review, the biochemical and molecular bases of the inflammatory process in the aging process are analyzed to delineate the molecular inflammation hypothesis of aging. The key players involved in the proposed hypothesis are the age-related upregulation of NF-kappa B, IL-1 beta, IL-6, TNFalpha, cyclooxygenase-2, and inducible NO synthase, all of which are attenuated by CR. Furthermore, age-related NF kappa B activation is associated with phosphorylation by I kappa B kinase/NIK and MAPKs, while CR blocked these activation processes. The modulation of these factors provides molecular insights of the anti-inflammatory action of CR in relation to the aging process. Based on available finding and our recent supporting evidence, we prefer to use "molecular inflammation" to emphasize the importance of the molecular reaction mechanisms and their aberrance, predisposing to fully expressed chronic inflammatory phenomena. It was further proposed that CR's major force of the regulation of redox-sensitive inflammation may well be its life-prolonging action.     

Behavioral Inhibition and Amplification During Emotional Arousal: A Comparison of Two Age Groups.

This study investigated age differences in the ability to suppress and amplify expressive behavior during emotional arousal. Young and old participants viewed 3 film clips about medical procedures while their behavioral, autonomic, and subjective responses were recorded. Half of the participants viewed all 3 films without additional instructions; the other half was asked to suppress and amplify their behavioral expression during the 2nd and 3rd films. Except for heart rate, suppression and amplification produced similar patterns of autonomic activation. Neither suppression nor amplification had effects on self-reported emotion. There were no age differences in the ability to suppress or amplify emotional expression or in their physiological or subjective consequences. Considering that older people's unregulated reactivity was lower than that of young adults, suppression may have been easier and amplification more difficult for older adults. Voluntary emotion regulation might be one domain of human performance that is spared from age-related losses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stability, Growth, and Decline in Adult Life Span Development of Declarative Memory: Cross-Sectional and Longitudinal Data From a Population-Based Study.

Five-year changes in episodic and semantic memory were examined in a sample of 829 participants (35-80 years). A cohort-matched sample (N=967) was assessed to control for practice effects. For episodic memory, cross-sectional analyses indicated gradual age-related decrements, whereas the longitudinal data revealed no decrements before age 60, even when practice effects were adjusted for. Longitudinally, semantic memory showed minor increments until age 55, with smaller decrements in old age as compared with episodic memory. Cohort differences in educational attainment appear to account for the discrepancies between cross-sectional and longitudinal data. Collectively, the results show that age trajectories for episodic and semantic memory differ and underscore the need to control for cohort and retest effects in cross-sectional and longitudinal studies, respectively. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Divergent trajectories in the aging mind: Changes in working memory for affective versus visual information with age.

Working memory mediates the short-term maintenance of information. Virtually all empirical research on working memory involves investigations of working memory for verbal and visual information. Whereas aging is typically associated with a deficit in working memory for these types of information, recent findings suggestive of relatively well-preserved long-term memory for emotional information in older adults raise questions about working memory for emotional material. This study examined age differences in working memory for emotional versus visual information. Findings demonstrate that, despite an age-related deficit for the latter, working memory for emotion was unimpaired. Further, older adults exhibited superior performance on positive relative to negative emotion trials, whereas their younger counterparts exhibited the opposite pattern. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

17-4PH马氏体不锈钢350℃长期时效脆化研究

采用光学显微镜(OM)、扫描电镜(SEM)、硬度测定以及示波冲击试验(instrumental impact test)研究了17-4PH马氏体不锈钢在350％：长期时效过程中显微组织、硬度、冲击韧性以及断口形貌的变化规律。结果表明：该马氏体不锈钢在350℃长期时效的过程中，随着时效时间的延长．其硬度升高，并在时效9000h时达到最大值；其裂纹萌生功(Ei)，裂纹扩展功(Ep)和总冲击功(Et)都随时效时间的延长而逐渐下降。根据示波冲击曲线获得了17-4PH马氏体不锈钢的动态断裂韧性Ktd，其动态断裂韧性也表现出和Ei，Ep及Et相类似的变化规律。该不锈钢的夏氏V型缺口(Charpy V-notch)冲击试样断口形貌随着时效时间的延长由韧窝断裂为主向准解理断裂和沿晶断裂为主变化。     

多级时效处理对7175铝合金组织和性能的影响

采用拉伸试验、电导率测试及电镜观察等方法,研究了重固溶后再经低温-高温-低温(LHL)多级时效处理对7175铝合金组织与性能的影响。结果表明,经过LHL处理以后,材料的性能有所提高。经过480℃×2h+85℃×12h+160℃×90m+130℃×9h处理后,能得到最佳的综合性能。当7175铝合金晶内析出相为更多更细小的GP区和小尺寸的η′相,晶界析出相尺寸较大且间距越大时,材料将对应着良好地综合性能。     

超高强钢23Co14Ni12Cr3强韧性的优化配合

主要考察了双时效工艺对超高强钢23Co14Ni12Cr3显微组织与力学性能的影响。在抗张强度没有明显降低的条件下，新创立的双时效比正常时效的冲击疲劳寿命与动态断裂韧性分别延长和提高了35．5％与22．6％。结果表明：双时效工艺在改善高强钢的强韧性优化配合方面是一新的突破。基于显微组织的观察结果，深入地分析了逆转变奥氏体AR稳定性提高和疲劳寿命延长的物理机制，不仅双时效的高温保温阶段所形成的AR韧性得到大幅度提高，而且在双时效的低温处理过程中，从马氏体铁素体中析出的间隙碳原子会扩散到逆转变奥氏体中，造成马氏体的脆性降低和奥氏体的稳定性进一步提高。     

金属注射成形冷作工具钢的超声疲劳性能

用超声疲劳试验研究了金属注射成形(MIM)冷作工具钢和锻轧钢(JIS SKD11)的高周疲劳性能。锻轧钢试样于423K回火1h。另一方面，为了评估回火温度对疲劳性能的影响，将MIM钢试样于不同温度下进行了回火。在N=103～108疲劳寿命范围内进行了超声疲劳试验。MIM钢试样的疲劳强度和锻轧钢试样相同。MIM钢试样的疲劳强度随着回火温度升高而减低。显微组织的观察结果表明，MIM钢试样的碳化物的直径与形状比锻轧钢试样的均一。     

并联干式电抗器故障原因分析

针对干式低抗多次在运行中起火烧毁和表面出现严重的树枝状放电故障,进行了绝缘材料的热老化性能试验、电抗器运行中温度测量、投切电抗器过电压测量以及运行电抗器解体分析试验和材料的漏电起痕等试验,揭示了干式电抗器故障的原因,并提出了反事故措施.