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   5796篇
  免费   487篇
  国内免费   9篇
耳鼻咽喉   58篇
儿科学   185篇
妇产科学   126篇
基础医学   842篇
口腔科学   168篇
临床医学   631篇
内科学   1092篇
皮肤病学   71篇
神经病学   655篇
特种医学   126篇
外科学   673篇
综合类   107篇
一般理论   7篇
预防医学   731篇
眼科学   129篇
药学   288篇
中国医学   9篇
肿瘤学   394篇
  2023年   69篇
  2022年   105篇
  2021年   224篇
  2020年   114篇
  2019年   198篇
  2018年   210篇
  2017年   142篇
  2016年   167篇
  2015年   180篇
  2014年   273篇
  2013年   299篇
  2012年   438篇
  2011年   447篇
  2010年   243篇
  2009年   222篇
  2008年   333篇
  2007年   345篇
  2006年   336篇
  2005年   285篇
  2004年   268篇
  2003年   227篇
  2002年   186篇
  2001年   76篇
  2000年   63篇
  1999年   63篇
  1998年   39篇
  1997年   30篇
  1996年   25篇
  1995年   20篇
  1994年   19篇
  1993年   21篇
  1992年   39篇
  1991年   34篇
  1990年   47篇
  1989年   41篇
  1988年   28篇
  1987年   35篇
  1986年   30篇
  1985年   25篇
  1984年   32篇
  1983年   13篇
  1982年   15篇
  1981年   14篇
  1979年   20篇
  1976年   12篇
  1974年   12篇
  1973年   14篇
  1972年   12篇
  1967年   13篇
  1966年   20篇
排序方式: 共有6292条查询结果,搜索用时 15 毫秒
1.
2.
Glutathione-S-transferase (GST) genes encode a family of detoxification enzymes that offer protection against endogenous and exogenous sources of reactive oxygen species (ROS). Germline variations in GST genes may alter the catalytic efficiency of GST isoenzymes leading to a potential increase in susceptibility to the genotoxic effects of ROS and electrophilic substances. A nested case-control study design was used to examine the association between the polymorphic GST genes and prostate cancer risk among Finnish male smokers of the ATBC Cancer Prevention Study. A case-case analysis was used to determine the association between these genetic polymorphisms and prostate cancer progression. Germline DNA was obtained from 206 prostate cancer cases and 194 controls frequency matched on age, intervention group and study clinic. Cases and controls were genotyped for three GST genes using MALDI-TOF mass spectrometry or multiplex polymerase chain reaction (PCR). Relative to the wild-type genotype, we observed a 36% reduction in prostate cancer risk associated with the GST-M1-null genotype (odds ratio (OR) 0.64, 95% confidence interval (CI) 0.43, 0.95). Unlike GST-M1, GST-T1-null (OR 0.74, 95% CI 0.42, 1.33) and GST-P1*B (OR 1.10, 95% CI 0.72, 1.69) were not strongly associated with prostate cancer risk. We did not observe any significant associations between the selected polymorphic GST genes and tumour grade or stage. In conclusion, we did not observe a direct association between polymorphic GST-T1 or GST-P1 and prostate cancer risk. Our observation of a relatively strong inverse association between the GST-M1-null genotype and prostate cancer risk needs to be confirmed in larger association studies.  相似文献   
3.
4.
5.
OBJECTIVES: To assess the attitudes and practices of contraceptive behaviors of Western Ukraine women. METHODS: A survey of 500 women in the Oblast was conducted to assess their knowledge, attitudes and practices on a variety of health topics. Convenience sampling was used to access the subjects in 16 different towns/villages in nine rayons throughout the Oblast. Respondents were asked more than 100 questions pertaining to their knowledge, attitudes and practices on a variety of health topics, including stress, contraception, breast health, sexually transmitted diseases, parity, abortion, nutrition, alcohol and tobacco use, domestic violence, and depression and mental health. RESULTS: Of married women, 44% (112/256) would terminate their pregnancy while 56% (144/256) said they would keep their baby. Of unmarried women, 35% (31/88) would abort while 65% (57/88) would keep their baby. A large proportion of married women (82%; 222/271) and unmarried women (70%; 52/74) did not use condoms at all. CONCLUSION: These results suggest lack of birth control education and contribution to poor protection from sexually transmitted infections. Higher abortion practices may also play a role in the infertility issues that Ukrainian women currently face.  相似文献   
6.
7.
This study examined the use and effectiveness of the Alert assessment form. The form is part of the Alert system, used by one large acute care hospital to identify patients with a propensity for violence. All reported incidents of patient violence from August 1, 2003, through December 31, 2004, were included in patient charts. One hundred seventeen violent patient charts were reviewed and compared with 161 non-violent patient charts, randomly chosen from the same time period. Overall use of the Alert assessment form for violent and non-violent patients was 75.7% and 35.4%, respectively. The assessment form was found to have moderate sensitivity (71%) and high specificity (94%). It is reasonably effective in identifying potentially violent or aggressive patients when it is used according to protocol. Efforts to improve the tool are warranted, as is evaluation of its benefit in settings with low prevalence of violence. Also, greater effort must be taken to prevent violence once an aggressive patient has been identified.  相似文献   
8.
OBJECTIVE--To assess sensory function in skin overlying the joints of patients with rheumatoid arthritis, in relation to the pain and tenderness which commonly arises in structures not directly involved in the inflammatory process. METHODS--An intradermal injection of capsaicin 0.05 microgram in 10 microliters was made over the wrists and forearms of 40 patients with rheumatoid arthritis and 46 control subjects. Axon reflex vasodilatation was measured using laser Doppler flowmetry. Cholinergic sympathetic function was assessed by measuring axon reflex sweating induced by a single intradermal injection of nicotine 0.5 microgram in 0.1 ml. RESULTS--Capsaicin induced axon reflex vasodilation over the wrists was found to decrease with age in normal subjects (r = -0.62, p < 0.001). In patients with rheumatoid arthritis, capsaicin induced axon reflex vasodilatation was significantly greater over the wrists, but not the forearms, when compared with age matched normal controls (p < 0.01). A minimal correlation between axon reflex vasodilatation and visual analogue pain score was apparent in the rheumatoid group (r = -0.37, p < 0.05). Nicotine induced sweating responses were similar in the rheumatoid and normal groups, and both showed a linear age related decline. CONCLUSIONS--The results show a selective increase of capsaicin induced vasodilatation in skin overlying joints in patients with rheumatoid arthritis. This suggests that the activity of a sub-population of periarticular small sensory fibres is altered, which may explain, at least in part, some of the clinical findings in this disorder.  相似文献   
9.
This article describes some of the factors to be considered by the practitioner when prescribing bitewing radiographs in the diagnosis and management of dental caries and draws on the literature of a number of disciplines including restorative dentistry, cariology, epidemiology and oral radiology. It seems appropriate to re-assess current practice in the light of information on changes in the disease of dental caries, its behaviour and the way this behaviour may vary in high and low caries risk groups. The diagnostic potential of the bitewing examination appears, at present, to be unrivalled, but other diagnostic methods, such as fibreoptic transillumination and tooth separation, must also be considered. Some methods to minimize radiation doses and increase diagnostic yield are discussed. Current knowledge of prescribing patterns is reviewed and areas of ignorance are mentioned as findings from future research in these areas may influence decisions about when to use and re-use bitewing radiographs.  相似文献   
10.
This study provides an overview of the papers emanating from the experimental trial that evaluated a new cognitive rehabilitation program in older adults who were experiencing normal cognitive decline. The main features of the design are summarized, along with evidence that the training produced long-lasting improvement in memory performance, goal management, and psychosocial status. The benefits were attributed to several factors, including the program's emphasis on techniques that promoted efficient strategic processing. Limitations of the program and directions for future research are discussed.  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