巧用VE对抗多种肌肤问题

随着年龄的增长，各种肌肤问题逐渐显现出来。特别是过了25岁，褐斑、干燥、松弛和细纹等肌肤常见问题，更是成为女人们的心头之恨!问题肌肤的根源——自由基许多肌肤问题是由自由基引起的。人体在新陈代谢的过程中，容易产生自由基，它具有很强的氧化反应能力，可损害细胞功能，促使人体衰老。而环境污染、工作压力、不良的生活习惯（如吸烟、经常服用避孕药等）、强紫外线和辐射等，都会使体内生成过多的自由基。     

自由基致衰老的研究进展

1954年Harman首次提出的自由基致衰老理论(free radical theory of aging, FRTA)认为,环境和内部代谢产生的自由基会对细胞成分造成损害,进而造成人体功能的损害,加速衰老。人体衰老研究发展迅速,学说众多,争论较大,但自由基理论一直受到广泛关注,多数文献肯定了自由基在致衰老、诱导某些慢性病发生方面的作用。本文从生物医学、分子病理学、流行病学等层面概括性地阐述了自由基的内涵与致病机制,重点介绍了近些年自由基研究的新进展以及与传统认识的差距。同时,本文提出了自由基致衰老的可能路径:自由基持续、动态、循环的作用于机体,当打破某种循环平衡时,衰老才可能发生。该路径为人群预防衰老、延缓衰老减少慢性病等工作带来了机遇与思考。     

专家提示人体衰老密码

自由基加速人体衰老 英国长寿协会凯拉扎伊讲座《世界抗衰老医学最新揭示》，指出自由基是衰老五大原因之一。自由基是新陈代谢副产品，是氧化剂。它具有重度破坏性，是细胞杀手。自由基参与糖基化等多种老化过程，例如：皮肤老化，动脉硬化，脑细胞凋亡等。     

浅议运用中医药理论指导抗衰老药物的研制及开发

浅议运用中医药理论指导抗衰老药物的研制及开发云南省医学情报研究所李其光衰老是一个极为复杂的过程，关于衰老的理论有许多学说，其中仅有关于自由基产生过氧化物致衰老的学说为大家所公认。由于衰老的本质尚未十分清楚，因而真正能干扰这一规律而达到延长自然寿命的抗...     

衰老的自由基学说与抗氧化食物

人类对衰老的研究已经有2000年的历史，有100多种不同的学说。其中美国哈尔曼教授提出的自由基学说认为，人体内自由基积累的毒害作用，是衰老的主要原因。抗氧化食物具有对抗自由基的作用。     

白血病患者血清脂质过氧化物及红细胞硒谷胱甘肽过氧化物酶活性变化

自由基是一种十分活跃的中间代谢产物，它可以使生物膜不饱和脂肪酸氧化而影响膜结构与功能，攻击蛋白，使之产生交联，从而改变酶的活性，损伤ＤＮＡ，引起突变和肿瘤。目前认为，自由基反应是衰老、肿瘤、休克、氧中毒及免疫损伤等病理过程的基础［１］。本文对白血病患...     

营养素与衰老标志物相关研究概述

衰老受遗传因素和环境因素的共同作用,其中营养素摄入在衰老的进程中起重要作用。在流行病学研究中,营养素摄入与衰老关系的研究主要集中在端粒-端粒酶学说、自由基学说和衰老的表观遗传学机制等衰老学说上。本文就营养素摄入与端粒长度、氧化损伤标志物及DNA甲基化水平等衰老标志物的关系进行综述,为延缓衰老对策的提出提供一定依据。     

衰老的原因与对策

关于衰老的理论有多种,但证据最充分、最实用并被学术界公认和接受的是自由基理论。专家的研究,在所有的疾病中,有80%～90%的疾病涉及自由基对肌体的损伤。损伤的根源在于抗氧化剂缺乏,从而引起衰老、疾病和死亡。因此,将由抗氧化剂缺乏所引起的损伤而     

知识改变生命——衰老与慢性疾病的关系

提到衰老，许多女性都会感到恐惧，从而与其抗争，来为自己的青春美丽争取更多的时间。其实衰老最可怕的并非容貌的改变，而是它引发的一系列慢性病的发生，其中对人类健康最具威胁性的是心脑血管疾病。而人类衰老的原因是多方面的，目前国际学术界公认的是自由基学说，就是机体细胞正常代谢过程中产生的自由基（具有强氧化性的有害化合物）失衡。损害了机体的组织和细胞．进而引起慢性疾病及衰老效应。     

番茄红素在肿瘤预防中的作用

番茄中含有较高含量的番茄红素，番茄红素是一种类胡萝卜素，它广泛存在于人体组织和血液中。人体在代谢的过程中，不可避免地产生一些自由基。自由基的氧化能力很强，会不断地攻击人体组织细胞，损伤DNA，导致免疫力下降、衰老、皮肤老化、色斑、肿瘤及多种疾病发生。目前已知由自由基造成或参与的疾病有100多种，如肿瘤、心脑血管硬化、心肌梗死、糖尿病、老年痴呆等。     

Calcium intake in the elderly: validation of a dietary questionnaire

Epidemiological studies of calcium and osteoporosis have been hampered by the lack of a suitable tool for assessing calcium intake. This report describes a new frequency and amount questionnaire for measuring present and past calcium intake in the elderly. The validity of the questionnaire was tested against two commonly used standards of dietary assessment, five-day duplicate diets and seven-day weighed dietary inventories. The resulting correlation coefficients were, respectively, r = 0.76 and r = 0.69, while that for repeatability was r = 0.84. Furthermore, the questionnaire categorized subjects into thirds of the distribution of intake with almost no gross misclassification. It is suggested that the present findings may be extended to the majority of normal, healthy elderly subjects, implying wide application for the questionnaire in the assessment of calcium intake in the elderly.     

The human drama of genetics: 'hard' and 'soft' media representations of inherited breast cancer

This paper examines media coverage of 'breast cancer genetics', and explores its implications for public understanding. We present a content analysis of coverage in British newspapers and look at a variety of popular forms, including women's magazines, television soap opera and radio drama. Genetic/inherited risk receives a great deal of coverage across a wide range of media formats and outlets. Much of this attention has focused on individuals from 'high risk families' and dilemmas around prophylactic mastectomies. Through examining media coverage, combined with interviews with media personnel and their sources, we show why this story proved so attractive to the media and highlight the different production values which influence coverage. Finally, we introduce preliminary findings from focus group discussions to demonstrate how such 'human interest' framing has engaged audience attention and influenced public understandings. The paper concludes by highlighting the implications for analysing, predicting, and engaging with, media representations of science.     

Self-reported health problems among Swedish miners one year after unemployment

Unemployment is considered to be a public health concern sincedeterioration in the health of the unemployed is often anticipated.However, for some groups, such as miners, unemployment mightimprove health due to a cessation of potentially harmful occupationalexposures. This study evaluates the health of 79 miners in oneSwedish iron-ore mine, and 226 age-matched controls from thegeneral population, during one year after the closure of themine. The participants received a questionnaire regarding medicalhistory and subjective symptoms at the beginning of the studyperiod, and after one year. Statistically significant negativeeffects on self-reported health attributable to unemploymentwere not found, although neuropsychiatric symptoms were morecommon among the unemployed miners. The miners reported a statisticallysignificant improvement in grip force (p=0.031). They had asignificantly higher prevalence of symptoms associated withmining related exposures when compared with the population controls;pain in the upper extremities [relative risk (RR)=2.27, 95%confidence interval (Cl)=1.44–3.59), back pain (RR=1.84;Cl=1.237–2.75), vasospastic disease of the fingers (RR=2.05;Cl=1.18–3.57) and obstructive respiratory symptoms (attacksof dyspnea and wheezing: RR=3.67; Cl=1.167–11.6).     

Excès de cas humains et animaux de tularémie en France au cours de l’hiver 2007–2008 : émergence ou phénomène isolé ?

Context

Tularemia is a zoonosis affecting humans and hares in France. We describe the results of surveillance in both species, in 2007 and 2008.

Methods

Human tularemia cases are mandatorily notifiable in France since 2003. In hares, surveillance relies on volunteer hunter associations in all districts of the country. Data from mandatory reports and volunteer surveillance in 2007/2008 were analyzed and compared with previous results.

Results

In 2007/2008, 144 cases were reported in humans and 117 cases in hares. This was a 100% increase compared to previous years. Human cases differed from those of previous years only by the frequency of contact with breeding animals. Human cases without any documented risk exposure were also more frequent.

Conclusion

An increase of tularemia cases occurred in 2007/2008 in both species. Complementary studies are needed to identify the species reservoir in France to understand the causes of this peak of cases.     

深圳公立医院管理体制改革制度设计

深圳公立医院管理体制改革实行政事分开、管办分开,在理事会架构下按法定机构模式组建市医管中心,落实公立医院运营管理自主权.作者从当前公立医院管理体制的弊端入手,介绍了深圳市进行公立医院管理体制改革的基本思路及改革方案设计的主要举措,深入剖析了的改革方案的特点,并对改革效果进行了预测.     

Effects of nitrogen dioxide on red blood cells of rats: Changes in components of red cell membranes during in vivo exposure to NO2

Red cell membranes, prepared from red blood cells of rats exposed to 4, 10, or 20 ppm nitrogen dioxide (NO₂) for 1 to 10 days, were examined for evidence of changes in membrane components. Appreciable changes were not found in contents of phospholipid and cholesterol during exposure to 10 ppm NO₂. By contrast, protein content altered with the time of exposure. Moreover, changes in protein composition were observed by employing sodium dodecyl sulfate — polyacrylamide gel electrophoresis. Twenty-four-hour exposure to NO₂ at the concentration above 10 ppm resulted in a marked increase in the percentage of lysophosphatidylethanolamine (LysoPE) to the total phospholipids. The prolonged exposure to 10 ppm NO₂ gave rise to a further increase in LysoPE, whereas the percentage of phosphatidylethanolamine (PE) showed a gradual decrease. A 1-day exposure to 4.0 ppm NO₂ also caused an increase in sialic acid content and decreases in those of PE and hexose. In addition to contents of these components the percentage of LysoPE increased 5 days after exposure and the elevated values were maintained up to the end of exposure period. These results demonstrate that red blood cells in circulation exhibit different membrane properties in terms of lipid and carbohydrate composition during 10 days of exposure to 4.0 ppm NO₂.     

Occupational health hazards in mining: an overview

This review article outlines the physical, chemical, biological, ergonomic and psychosocial occupational health hazards of mining and associated metallurgical processes. Mining remains an important industrial sector in many parts of the world and although substantial progress has been made in the control of occupational health hazards, there remains room for further risk reduction. This applies particularly to traumatic injury hazards, ergonomic hazards and noise. Vigilance is also required to ensure exposures to coal dust and crystalline silica remain effectively controlled.     

Manufacture and use of nanomaterials: current status in the UK and global trends

This paper provides an overview of the production and use of nanomaterials (NMs), particularly in the UK. Currently, relatively few companies in the UK are identifiable as NM manufacturers, the main emphasis being the bulk markets in metals and metal oxides, and some niche markets such as carbon nanotubes and quantum dots. NM manufacturing in the UK does not reflect the global emphasis on fullerenes, nanotubes and fibres. Some assumptions have been made about the types of NM that are likely to be imported into the UK, which currently include fullerenes, modified fullerenes and other carbon-based NMs including nanotubes. Many university departments, spin-offs and private companies have developed processes for the manufacture of NMs but may only be producing small quantities for research and development (R&D) purposes. However, some have the potential to scale up to produce large quantities. The nanotechnology industry in the UK has strong R&D backup from universities and related institutions. This review has covered R&D trends at such institutions, and appropriate information has been added to a searchable database. While several companies are including NMs in their products, only a few (e.g. manufacturers of paints, coatings, cosmetics, catalysts, polymer composites) are using nanoparticles (NPs) in any significant quantities. However, this situation is likely to change rapidly. There is a need to collect more information about exposure to NPs in both manufacturing and user scenarios. As the market grows, and as manufacturers switch from the micro- to the nanoscale, the potential for exposure will increase. More research is required to quantify any risks to workers and consumers.     

The risk of heat exhaustion at a deep underground metalliferous mine in relation to surface temperatures

The risk of heat exhaustion at a deep underground metalliferous mine was assessed in relation to thermal conditions prevailing on the surface. For each day of a 1-year prospective case series of heat exhaustion, surface 24-h mean wet and dry bulb temperatures were recorded. From this data, 24-h mean wet bulb globe temperatures were derived using certain assumptions. The three surface temperature variables were significantly higher on those days on which heat exhaustion occurred, compared to those days on which it did not occur (P < 0.001). The relative risk of heat exhaustion on days when the 24-h mean wet bulb globe temperature was in the range 26.0-28.0 degrees C was 4.82 (95% confidence interval 2.12-10.96). Surface temperature data could be used at this mine to warn miners about the risk of heat exhaustion.