首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   49篇
  免费   4篇
  国内免费   17篇
安全科学   6篇
综合类   44篇
基础理论   13篇
污染及防治   4篇
评价与监测   3篇
  2022年   2篇
  2021年   3篇
  2020年   2篇
  2019年   2篇
  2018年   3篇
  2017年   3篇
  2016年   1篇
  2015年   2篇
  2014年   1篇
  2013年   10篇
  2012年   2篇
  2011年   5篇
  2010年   1篇
  2009年   5篇
  2008年   2篇
  2007年   2篇
  2006年   5篇
  2005年   2篇
  2004年   1篇
  2003年   2篇
  2002年   2篇
  2001年   6篇
  1999年   1篇
  1996年   1篇
  1994年   2篇
  1992年   1篇
  1985年   1篇
排序方式: 共有70条查询结果,搜索用时 16 毫秒
1.
2.
Non-mosaic trisomy 20 is rare in fetuses surviving beyond the first trimester. We report a case of a fetus with non-mosaic trisomy 20 in amniotic fluid cultures obtained during the prenatal evaluation of an unusual thoraco-abdominal mass which was found at autopsy to be pulmonary sequestration. Gross inspection and autopsy of the fetus revealed multiple anomalies. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
3.
The present study describes an association between adverse outcome in the twin-to-twin transfusion syndrome (TTTS) and pulmonary stenosis or reactive right ventricular hypertrophy. Six discordant monozygotic twin pregnancies with TTTS are described. Ventricular hypertrophy and atrioventricular valvular regurgitation occurred in all the recipient twins with pulmonary valvular stenosis in three cases and infundibular stenosis in one case. The recipient twin in one pair and both twins in another pregnancy died as a consequence of immaturity but the remaining twins all survived. Surgical intervention was required in one baby for valvular pulmonary stenosis. Our observations suggest that elevated blood pressure in the transfusion recipient may play an important role in pathogenesis. We hypothesise that both pulmonary stenosis and right chamber hypertrophy are secondary to hemodynamic changes. Although we have found valvular pulmonary stenosis in three recipients and infundibular stenosis in only one, this (obstruction to outflow) could be due to right chamber hypertrophy. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
4.
流行病学研究表明,空气细颗粒污染物(PM_(2.5))的暴露与过敏性疾病有一定的联系;然而,PM_(2.5)暴露与过敏性疾病之间的关系尚未完全阐明,特别是室内环境中PM_(2.5)涉及到过敏或非过敏的作用不详.为了比较研究过敏与非过敏儿童室内PM_(2.5)的细胞毒性,在武汉市洪山区10户家庭室内进行了为期3个月的采样,分别收集过敏与非过敏儿童的室内PM_(2.5).采用有机/元素碳测定仪对二者PM_(2.5)成分中的含碳组分进行了分析,并通过检测昆明小鼠巨噬细胞的形态及吞噬功能影响、细胞活力、乳酸脱氢酶(LDH)漏出率等指标,来检测PM_(2.5)暴露所致的细胞毒性.结果表明,高剂量(200μg·mL~(-1))PM_(2.5)暴露对小鼠巨噬细胞的形态及吞噬功能会产生不利的影响;与非过敏儿童的室内PM_(2.5)暴露组相比,过敏儿童的室内PM_(2.5)暴露组诱导巨噬细胞产生的毒性作用更明显.细胞体外测试结果提示:在相同PM_(2.5)暴露剂量下,引起儿童过敏症的室内PM_(2.5)成分具有重要影响.  相似文献   
5.
6.
A pleural effusion associated with congenital pulmonary lymphangiectasia was detected in a fetus in utero but was absent at the time of delivery. The pleural effusion was unilateral although the disease involved both lungs. In this case there was an association between polyhydramnios and congenital pulmonary lymphangiectasia.  相似文献   
7.
Bisphenol A (BPA) is the monomer component of polycarbonate plastics and classified as an endocrine disrupting chemical (EDC). The reproductive toxicity of BPA has been extensively studied in mammals; however, relatively little information is available on the immunotoxic responses of fish to BPA. In this study, we investigated the effects of BPA on the immune functions of lymphocytes and macrophages in Carassius auratus. The effects of BPA were compared with those of two natural steroid hormones, estradiol and hydrocortisone. Proliferation of the two types of cells in response to PHA was measured using colorimetric MTT assay. Macrophage respiratory burst stimulated by Con A was measured using chemiluminescence assay. Results showed that BPA (0.054-5.4 mg/L), estradiol (0.0002-2.0 mg/L) and hydrocortisone (5-50 mg/L) significantly induced Carassius auratus lymphocyte proliferation while higher doses of hydrocortisone (500-5000 mg/L) appeared to be inhibitory. BPA (0.005-50 mg/L), estradiol (0.005-800 mg/L) and hydrocortisone (0.005-500 mg/L) markedly enhanced macrophage proliferation, whereas higher doses of BPA (500-1000 mg/L) appeared to inhibit cell proliferation. Furthermore, higher dosage of BPA (50 mg/L) and hydrocortisone (50 and 500 mg/L) suppressed the macrophages respiratory burst while estradiol is stimulative all the doses tested (0.05-500 mg/L). In conclusion, BPA could have immunotoxicity to Carassius auratus and functional changes of lymphocyte and macrophage in Carassius auratus may be different between low and high dosages.  相似文献   
8.
虽然人类社会不断进步发展,但大量工业和自然排放也导致了严重的空气污染。大气颗粒物是大气污染物的主要成分之一,黑碳是其中的重要组成成分,被国际癌症研究机构(IARC)归类为2B类致癌物。黑碳可以吸附其他致癌物质,会对环境和人体健康产生不利影响,因此黑碳暴露对人类的危害得到越来越多的重视。空气中黑碳的水平与心血管、呼吸和神经系统疾病的发生都有关系;黑碳主要通过引起氧化应激和炎症反应,诱发基因突变等一系列损伤。虽然现今对于黑碳健康效应的研究已取得了一些进展,但研究多数处于起步阶段,且仅针对黑碳本身进行单独研究,未来还需要加强开展对黑碳和其他污染物联合毒性效应及机制的研究。本综述主要针对近年来已开展的研究进行了总结归纳。  相似文献   
9.
This study evaluated the influence of welding on pulmonary functions in welders. Spirometry tests were performed before and after work shift in 91 welders and 25 clerks (control group). We examined forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC ratio and forced expiratory flow 25%-75% (FEF 25–75). Significant differences were found for FVC and FEV1/FVC between welders and the control group in pre- and post-shift measurements (p < .001). In welders, smoking and nonsmoking habit had no significant effects on any pulmonary indices before or after shift. Work experience and fume concentrations also had no significant effects on the majority of spirometric indices (p > .05). Most welders had at least 1 of the respiratory symptoms. Significant differences were found between pre- and post-shift indices (as percentage of predicted values calculated with spirometer) and between the welders engaged in some welding tasks and the control group before work shift. This study documented work-related changes in pulmonary functions in the welders and marked drops in these functions without symptoms in some welders.  相似文献   
10.
2004年3月采集甘肃省武威市和内蒙古包头市正常良好天气、局地扬沙天气和沙尘暴天气的大气细颗粒物(PM2.5)样品,以不同浓度的细颗粒物悬液体外处理大鼠肺泡巨噬细胞后测定细胞内丙二醛(MDA)、谷胱甘肽(IgSH)及胞质游离Ca^2 含量,并观察不同处理时间的细胞存活率.研究结果表明:(1)沙尘暴与非沙尘暴PM2.5均使细胞内MDA和Ca^2 含量升高、GSH含量下降,且对细胞毒性存在时间.效应和剂量.效应关系,(2)PM2.5对各指标的影响仅与处理剂量有关,而与样品种类无关.沙尘暴期间大气PM2.5浓度很高,因而沙尘暴PM2.5的危害作用不可忽视。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号