<tt id="6hsgl"><pre id="6hsgl"><pre id="6hsgl"></pre></pre></tt>
          <nav id="6hsgl"><th id="6hsgl"></th></nav>
          国产免费网站看v片元遮挡,一亚洲一区二区中文字幕,波多野结衣一区二区免费视频,天天色综网,久久综合给合久久狠狠狠,男人的天堂av一二三区,午夜福利看片在线观看,亚洲中文字幕在线无码一区二区
          US EUROPE AFRICA ASIA 中文
          Opinion / Op-Ed Contributors

          Odds must deter the fight against doping

          By Maléne Lindholm (chinadaily.com.cn) Updated: 2016-08-25 10:20

          Odds must deter the fight against doping

          Technicians Ilya Podolsky and Natalia Bochkaryova work at the Russian anti-doping laboratory in Moscow, Russia, May 24, 2016. [Photo/Agencies]

          Elite sports and doping have long been deeply interlinked. Reaching an elite level in sports requires a tremendous amount of hard work, dedication and focus. By definition, few succeed, but those who do may enjoy great personal and financial rewards. Using performance-enhancing substances can seem like an easy way to boost one’s chances of reaching — or remaining at — that top level.

          Doping in sports has most likely been going on for centuries. But the successful isolation of androgenic anabolic steroids brought a surge in the practice in the 1930s. The effects on performance can be seen in the extraordinary results of East German athletes in the 1970s and 1980s, some of whose records have yet to be broken. But the drawbacks of anabolic steroids were no less obvious: those same athletes often experienced infertility, cardiovascular problems, tumors and other adverse effects.

          After a doping test for these steroids became mandatory in 1975, numerous athletes have been caught and sanctioned. Yet these substances remain the most commonly abused in elite sports.

          Another common doping substance is recombinant erythropoietin (EPO), a protein that increases endurance by stimulating production of oxygen-carrying red blood cells. The downside is increased risk of stroke and myocardial infarction. In one of the greatest doping scandals of the 21st century, Lance Armstrong, seven-time Tour de France winner, was found to have used it after years of denial. Some athletes also resort to so-called blood doping — transfusions of oxygenated blood before an event, which achieves a similar result as EPO.

          Since its establishment in 1999, World Anti-Doping Agency has been leading the charge to curb doping by improving detection and testing. Researchers have continually developed new, more accurate methods for detecting a wider variety of substances.

          One recent innovation is a testing method that detects long-term metabolites left behind by anabolic steroids. Re-analysis of test samples from the 2008 and 2012 Olympic Games using these techniques shows up to 8 percent were positive for doping, compared with the 1 percent previously detected. To maximize the impact of this technology, doping tests are now required more frequently, not only during competitions, but also between them.

          But just as the technology for detecting substances improves, new methods of artificial performance enhancement emerge. In particular, the rise of gene therapy has raised the possibility of introducing genes or genetically modified cells into the body to boost athletic performance.

          Clinical trials are ongoing for several genes of interest for enhancing athletic performance, including EPO. Experience suggests that the many known and unknown risks associated with gene therapy will do little to deter its use for doping purposes.

          With “gene doping” close to becoming a reality, WADA is already working to counter it. Gene doping has been prohibited since 2003, and the first detection method, based on EPO’s gene sequence, was implemented this year.

          The key to that method is distinguishing between normal genes, which contain both coding and non-coding elements, and artificial genes, which contain only the coding elements. DNA without non-coding elements that has leaked into plasma is evidence of gene doping. Other potential detection methods, likely to be implemented in the near future, could identify traces of the viral vector or detect activating substances used to enhance activity of the newly introduced gene.

          The battle against doping in elite sports can sometimes feel interminable. Advances in detection, however impressive, seem to be continually outpaced by innovations in doping. But giving up is not an option. Doping deeply undermines the integrity of elite sports, which are supposed to be a demonstration of what the human body can achieve — not how far extreme pharmaceutical manipulation of the human body can take us.

          The author is a researcher at Karolinska Institute in Solna, Sweden.

          Project Syndicate

          Most Viewed Today's Top News
          Brexit tells world to change path of globalization
          ...
          主站蜘蛛池模板: 免费国产va在线观看| 精品在免费线中文字幕久久| 亚洲国产成人无码网站| 成人午夜免费无码视频在线观看 | 免费国产午夜理论片不卡| 亚洲一区二区乱码精品| 午夜福利国产精品视频| 亚洲国产熟女一区二区三区| 成人无码午夜在线观看| 无遮无挡爽爽免费视频| 黄页网址大全免费观看| 久在线视频播放免费视频| 一本大道无码av天堂| 国产精品毛片va一区二区三区| 欧美色丁香| 亚洲www永久成人网站| 特级做a爰片毛片免费看无码 | 国产成AV人片久青草影院| 中文字幕日韩精品亚洲一区| 少妇 人妻 欧美| 少妇精品视频一码二码三| 亚洲精品自拍区在线观看| 人妻丰满熟妇av无码区乱| 国内熟女中文字幕第一页| 欧美怡春院一区二区三区| 天天躁日日躁狠狠躁| 国产国语一级毛片| 欧洲中文字幕一区二区| 人妻在线无码一区二区三区| 久久久这里只有精品10| 国产情侣激情在线对白| 日本亚洲欧洲无免费码在线| a级黄色毛片免费播放视频| 九九热精品视频在线免费| 成人免费无码视频在线网站| 亚洲女同精品一区二区久久| 国产乱人伦真实精品视频| 国产精品自拍午夜福利| 国产伦精品一区二区三区| 中文字幕久久精品波多野结| 99热精品毛片全部国产无缓冲|