长期暴露于二氧化氮中将降低体外受精成功几率-凯发k8官网

长期暴露于二氧化氮中将降低体外受精成功几率
文章来源:未知 文章作者:meng 发布时间:2010-04-13 03:10 字体: [ ] 
(单词翻译:双击或拖选)

exposure to an increased level of air 2(空气污染物) , especially nitrogen dioxide(二氧化氮) , has been associated with lower likelihoods(可能性) of successful 3 among women undergoing in vitro fertilization(体外受精) , according to a team of fertility researchers. the team examined the outcomes of the first pregnancy attempt of 7,403 women undergoing ivf at penn state milton s. hershey medical center, hershey, pa.; shady 4 fertility, rockville, md.; and columbia university college of physicians and surgeons, new york, n.y. they conducted their observations over a seven-year period from 2000 to 2007.

"numerous studies have consistently shown a relationship between air pollution and human health, ranging from mortality, cardiovascular disease(心血管疾病) and other 5 conditions," said duanping liao, ph.d., professor of epidemiology(流行病学,传染病学) and 6 chair department of public health sciences, penn state college of medicine. "in the process of searching for the 7 responsible for the above associations, we, and others, have reported significant links between air pollution and inflammation and increased blood 8(血液凝结) . these intermediate factors are also associated with reproductive health."

the ivf population was chosen, as it is a well-controlled and timed process to investigate the association of air pollution and human reproductive effects.

burning of fossil fuels and 9 engine(柴油机) 10 produces nitrogen dioxide and fine particles. researchers looked at those pollutants along with 11, the gas involved in smog formation. while the effects of declining air quality on ivf success are variable and 1-dependent, elevated exposures to nitrogen dioxide and fine particles were consistently associated with lower success rates of pregnancy.

researchers looked at the effects of pollution particles both individually -- single pollutant model, and with other particles -- multi-pollutant model. for the single pollutant model, exposure to ozone appeared to have a positive association with a successful birth if the exposure was before the 12(胚胎,胚芽) culture or embryo transfer. researchers theorize(推理) that higher ozone levels indicate lower nitrogen dioxide levels, which would show better pregnancy outcomes. in addition, for the multi-pollutant model, the "positive" effects of ozone were diminished(减少,削弱) with the addition of nitrogen dioxide. in contrast, after adjusting for ozone, higher nitrogen dioxide exposures consistently associated with the lower success rate, regardless of which indictor was used -- positive pregnancy test, clinically confirmed intrauterine(子宫内的) pregnancy or live birth.

these findings may be useful in studying the 13 effects of air pollution on human reproduction in general.

"since ivf is a well controlled and highly timed process, we have a much better handle on the 14 of the time of exposures to elevated(提高) air pollutants in relationship to fertilization, pregnancy, and delivery," liao said. "therefore, the ivf population coupled with 15 assessment of air pollution exposures may provide us an ideal situation to investigate the potential health effects of air quality on human reproduction."

air pollutant concentration data for the study period came from the u.s. environmental protection agency. the researchers calculated daily pollution concentrations for each patient during the entire in vitro cycle and pregnancy. they calculated varying periods of air quality exposure for average daily concentrations at the patient's home during four stages of ivf and at the ivf clinic during fertilization and embryo transfer.



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1 n1zzy     
n.污染物质,散布污染物质者
参考例句:
  • coal itself is a heavy pollutant.煤本身就是一种严重的污染物。
  • carbon dioxide may not be a typical air pollutant.二氧化碳可能不是一种典型的污染物。
2 694861490fe64672170a0da250a277c7     
污染物质(尤指工业废物)( pollutant的名词复数 )
参考例句:
  • pollutants are constantly being released into the atmosphere. 污染物质正在不断地被排放到大气中去。
  • the 1987 amendments limit 301(g) discharges to a few well-studied nonconventional pollutants. 1987年的修正案把第301条(g)的普通排放限制施加在一些认真研究过的几种非常规污染物上。 来自英汉非文学 - 环境法 - 环境法
3 lpwxp     
n.怀孕,怀孕期
参考例句:
  • early pregnancy is often accompanied by nausea.怀孕早期常有恶心的现象。
  • smoking during pregnancy increases the risk of miscarriage.怀孕期吸烟会增加流产的危险。
4 v5wyy     
n.林子,小树林,园林
参考例句:
  • on top of the hill was a grove of tall trees.山顶上一片高大的树林。
  • the scent of lemons filled the grove.柠檬香味充满了小树林。
5 bo9zl     
adj.(疾病)长期未愈的,慢性的;极坏的
参考例句:
  • famine differs from chronic malnutrition.饥荒不同于慢性营养不良。
  • chronic poisoning may lead to death from inanition.慢性中毒也可能由虚弱导致死亡。
6 nu0zq     
n.坏事;恶习;[pl.]台钳,老虎钳;adj.副的
参考例句:
  • he guarded himself against vice.他避免染上坏习惯。
  • they are sunk in the depth of vice.他们堕入了罪恶的深渊。
7 d0db71d70348ef1c49f05f59097917b8     
n.机械( mechanism的名词复数 );机械装置;[生物学] 机制;机械作用
参考例句:
  • the research will provide direct insight into molecular mechanisms. 这项研究将使人能够直接地了解分子的机理。 来自《简明英汉词典》
  • he explained how the two mechanisms worked. 他解释这两台机械装置是如何工作的。 来自《简明英汉词典》
8 9eca3747f25ae6f0d50d00d5b71d5d7d     
v.凝固( clot的现在分词 );烧结
参考例句:
  • the study was also based only on the one anti-clotting drug. 所用抗血栓药物也仅限于一种。 来自互联网
  • a plasma protein that is converted into thrombin during blood clotting. 凝血原酶一种血浆蛋白质,在血液凝聚时转化成凝血''。'酵'。''''。'素'。''。 来自互联网
9 ql6zo     
n.柴油发动机,内燃机
参考例句:
  • we experimented with diesel engines to drive the pumps.我们试着用柴油机来带动水泵。
  • my tractor operates on diesel oil.我的那台拖拉机用柴油开动。
10 4qkzs     
n.燃烧;氧化;骚动
参考例句:
  • we might be tempted to think of combustion.我们也许会联想到氧化。
  • the smoke formed by their combustion is negligible.由它燃烧所生成的烟是可忽略的。
11 omqzbe     
n.臭氧,新鲜空气
参考例句:
  • the ozone layer is a protective layer around the planet earth.臭氧层是地球的保护层。
  • the capacity of ozone can adjust according of requirement.臭氧的产量可根据需要或调节。
12 upaxt     
n.胚胎,萌芽的事物
参考例句:
  • they are engaging in an embryo research.他们正在进行一项胚胎研究。
  • the project was barely in embryo.该计划只是个雏形。
13 5xbzs     
adj.不利的;有害的;敌对的,不友好的
参考例句:
  • he is adverse to going abroad.他反对出国。
  • the improper use of medicine could lead to severe adverse reactions.用药不当会产生严重的不良反应。
14 vo7yu     
n.评价;评估;对财产的估价,被估定的金额
参考例句:
  • this is a very perceptive assessment of the situation.这是一个对该情况的极富洞察力的评价。
  • what is your assessment of the situation?你对时局的看法如何?
15 xunzms     
adj.详细的,详尽的,极注意细节的,完全的
参考例句:
  • he had made a detailed study of the terrain.他对地形作了缜密的研究。
  • a detailed list of our publications is available on request.我们的出版物有一份详细的目录备索。
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tag标签: air population pregnancy
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