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   259篇
  免费   55篇
  国内免费   1篇
基础医学   42篇
临床医学   9篇
内科学   5篇
神经病学   3篇
特种医学   102篇
外科学   3篇
综合类   11篇
预防医学   116篇
药学   14篇
肿瘤学   10篇
  2023年   3篇
  2022年   12篇
  2021年   7篇
  2020年   8篇
  2019年   4篇
  2018年   10篇
  2017年   5篇
  2016年   9篇
  2015年   11篇
  2014年   21篇
  2013年   22篇
  2012年   16篇
  2011年   12篇
  2010年   8篇
  2009年   12篇
  2008年   16篇
  2007年   15篇
  2006年   16篇
  2005年   11篇
  2004年   18篇
  2003年   12篇
  2002年   10篇
  2001年   7篇
  2000年   4篇
  1999年   6篇
  1998年   5篇
  1997年   4篇
  1996年   2篇
  1995年   3篇
  1994年   2篇
  1992年   3篇
  1991年   4篇
  1990年   1篇
  1989年   2篇
  1988年   1篇
  1987年   2篇
  1984年   2篇
  1982年   2篇
  1980年   1篇
  1978年   2篇
  1976年   3篇
  1975年   1篇
排序方式: 共有315条查询结果,搜索用时 291 毫秒
1.
Using two-stage clonal expansion model with data-base provided by Lubin, WD Hazehon et al indicated the high risk of arsenic, but not radon, in the etiology of Yunnan tin miner' s lung cancer. The author of this review iterated the problems in the data-base of Lubin,and considered that it may result in low estimate for the risk of radon in paper of Hazehon et al. Attributable risk was estimated by them with changing exposure patterns of each individual, but the efficacy of this two-stage model will be violated by the invariability of appointed radon/arsenic exposures. Risk comparison was used to distinguish the contribution from radon/arsenic, which was hampered by the high correlation between their joint exposures. As Lubin, Hazehon et al neglected the confounding from environmental arsenic pollution in early years. From all of above, their viewpoint is worth to be deliberated.  相似文献   
2.
3.
The risk estimates for individual carriers of ten different familial reciprocal translocations detected among 500 couples with reproductive failures are presented. These were established by application of the empirical data analysed by Stengel-Rutkowski et al. (1988) and the guidelines given in Stene & Stengel-Rutkowski (1988). Different risks were estimated for unbalanced offspring at birth or at second trimester prenatal diagnosis for abortions, or stillbirths/early deaths. These risk estimates varied considerably from translocation to translocation. Carriers of five translocations had risks for offspring with single-segment imbalances. The birth risk figures ranged from 0.1% to 13.8%. Carriers of five other translocations had risks for double-segment imbalances with birth risks ranging from 0% to 3.2%. The estimated risk figures were independent of the method of ascertainment. Among the parents of the index cases we found nine maternal carriers and only one paternal carrier. This presentation illustrates the need for individual risk counselling of each carrier with reciprocal translocation regarding further family planning.  相似文献   
4.
The purpose of the present study was to reduce background tracks by removing a given surface layer of the 250 μm thick lexan polycarbonate foils before exposure to alpha particles. Ethylenediamine solution was used for taking layers from the surface of the foils.  相似文献   
5.
Genomic in-situ hybridization (GISH) was applied to study the behaviour of addition chromosomes in first and second backcross (BC) progenies of hybrids between Brassica napus ssp. napus L. (AACC, 2n = 38) and Sinapis alba L. (SS, 2n = 24) produced by electrofusion. With GISH using genomic DNA of S. alba was used as probe it was possible to clearly distinguish both of the parental genomes and effectively monitor the fate of S. alba chromosomes in the BC1 and BC2 progenies. GISH analysis confirmed the sesquidiploid genome composition (AACCS) of the BC1 progenies, which contained 38 chromosomes from B. napus and 12 chromosomes from S. alba. Genome painting in the pollen mother cells (PMCs) of the BC1 plants revealed intergenomic association between B. napus and S. alba chromosomes, whereby a maximum of 4 trivalents between AC and S chromosomes were identified at metaphase I. In the BC2 progenies, aneuploids with different numbers of additional chromosomes from S. alba, ranging from 1 to 7, were confirmed. Three putative monosomic alien addition lines were characterized, and the results are discussed with respect to the potential for intergenomic chromosome recombination.  相似文献   
6.
目的 了解江西省某典型非铀矿山高氡暴露矿工的健康效应现状。方法 采用普查的方法,对≥40岁井下一线工人进行基本情况、氡知晓率的调查,并开展井下一线矿工职业健康检查和肺部低剂量 CT 筛查。结果 井下一线矿工对氡的知晓率仅为3.70%,外周血淋巴细胞染色体畸变分析发现100个细胞畸变率为0%、外周血淋巴细胞微核试验的异常率为0.02‰,眼科检查(晶体裂隙灯检查、玻璃体、眼底)均未见异常,白细胞数异常率为3.70%,肺部小结节检出率为48.15%。结论 高氡暴露井下一线矿工肺部小结节检出率较高,矿工对氡缺乏认知,亟需加强矿工关于氡的危害宣传教育及井下一线矿工的职业病预防控制。  相似文献   
7.
Quercetin has been shown to have anti-obesity effects, but it is unknown whether these effects can be transmitted from mothers to their progeny. In this study, we investigated whether maternal quercetin consumption during pregnancy has a protective effect on high-fat diet–induced hyper lipid levels and overweight in progeny. Female mice consumed a control diet or a diet containing 1.0% quercetin during breeding. The male progeny were then divided into four groups that were (1) sacrificed at postnatal day 3; (2) born to dams fed the control diet and also fed the control diet (C-C), (3) born to dams fed the control diet and then fed a 30% high-fat diet (C-HF), or (4) born to dams fed the Q-diet and then fed the HF diet (Q-HF). Maternal consumption of quercetin did not affect body weight or blood lipid parameters in either dams or neonates at postnatal day 3. After 13 weeks, the Q-HF group exhibited greater body and liver weights, and higher blood cholesterol levels than the C-HF group. However, the total cholesterol/ high density lipoprotein (HDL)-cholesterol ratios in the Q-HF and C-C groups remained similar. In conclusion, maternal quercetin consumption does not appear to protect the next generation from high-fat diet–induced hyper cholesterol level in the blood and liver, and consequently overweight, but may help regulate the total cholesterol/HDL-cholesterol ratio.  相似文献   
8.
ObjectiveTo assess the association between exposure to radon and genitourinary cancer in a mining population through a systematic review of the scientific literature.MethodA systematic review of the scientific literature was carried out in MEDLINE (PubMed), combining MeSH (Medical Subject Heading) terms and free terms. We applied a specific scale to assess the quality of the included studies.ResultsWe included 17 studies; all were cohort studies with the exception of one which was a pooling of data. All studies included analysed the relationship between exposure to radon and genitourinary cancer. While some studies point towards an association between radon exposure and genitourinary cancer, especially kidney cancer, others do not find such association.ConclusionsThe included studies showed great heterogeneity. It cannot be concluded that there is an association between exposure to radon and genitourinary cancer. More research is needed on this topic, designing studies with higher statistical power, better control of confounders, and preferably prospective.  相似文献   
9.
目的了解室内空气中氡的本底水平,找出氡的不同来源对室内的相对贡献。方法 REM-2型氡析出率仪对地面和墙壁表面进行氡析出的测量,利用FD-125氡钍分析仪对室内用水和煤气中氡的含量作了分析,探讨了太原市居室内空气中氡本底水平。结果室内氡主要是由土壤、建材中析出的,其次才是室外空气中氡的渗入,室内用水和煤气中氡贡献很小。结论根据调查结果,进行室内空气中氡对人体健康危害分析和剂量评价,建立了室内氡本底水平的数据库,为以后研究室内氡的防护措施提供了依据。  相似文献   
10.
A large volume transfer standard has been developed to calibrate commercial radon measurement devices in a homogeneous Rn-222 reference atmosphere. The transfer standard serves for the realization, maintenance and dissemination of the unit Bq/m3 below 1 kBq/m3.The transfer standard consists of a multi-wire impulse ionization chamber, electronic measurement equipment and the corresponding software. The multi-wire impulse ionization chamber is composed of two parallel printed boards. Between the boards, 478 vertical electrode wires are soldered in to include a volume of 10 L. In the dependency of the energy, the α-particles of Rn-222 and the decay products are detected in the active volume of the multi-wire impulse ionization chamber. By means of the measurement software an α-energy spectrum is produced. Via different algorithms, the activity concentration of the Rn-222 reference atmosphere is determined.  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