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   11255篇
  免费   663篇
  国内免费   40篇
耳鼻咽喉   176篇
儿科学   413篇
妇产科学   267篇
基础医学   1474篇
口腔科学   235篇
临床医学   832篇
内科学   2751篇
皮肤病学   488篇
神经病学   829篇
特种医学   382篇
外科学   1543篇
综合类   47篇
一般理论   3篇
预防医学   1055篇
眼科学   161篇
药学   598篇
中国医学   46篇
肿瘤学   658篇
  2023年   63篇
  2022年   153篇
  2021年   360篇
  2020年   135篇
  2019年   307篇
  2018年   404篇
  2017年   208篇
  2016年   206篇
  2015年   256篇
  2014年   409篇
  2013年   478篇
  2012年   549篇
  2011年   618篇
  2010年   368篇
  2009年   395篇
  2008年   531篇
  2007年   535篇
  2006年   527篇
  2005年   558篇
  2004年   557篇
  2003年   556篇
  2002年   517篇
  2001年   382篇
  2000年   433篇
  1999年   331篇
  1998年   91篇
  1997年   77篇
  1996年   93篇
  1995年   66篇
  1994年   59篇
  1993年   50篇
  1992年   191篇
  1991年   150篇
  1990年   163篇
  1989年   139篇
  1988年   135篇
  1987年   120篇
  1986年   106篇
  1985年   90篇
  1984年   72篇
  1983年   45篇
  1982年   26篇
  1979年   49篇
  1978年   26篇
  1977年   28篇
  1976年   30篇
  1975年   41篇
  1974年   42篇
  1972年   29篇
  1969年   25篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Summary Nonmelanoma skin cancer (NMSC) is the most common malignancy occurring in white populations. It is currently becoming an important challenge in terms of public health management as the increasing incidence rates will probably have a tremendous impact on healthcare costs. Possible factors driving this rise in NMSC numbers are increases in both acute and prolonged UV exposure together with increasing numbers of older people in the population. A better understanding of NMSC epidemiology in Europe is essential if an evidence-based European-wide public health policy is to be developed. It is obvious this can only be achieved by recording and analysing comparative epidemiological data. Finally, by improving the skin examination training for physicians, developing guidelines and exchanging best practices, a high level of healthcare could be provided for NMSC.  相似文献   
32.
OBJECTIVE: Several studies have shown that repetitive transcranial magnetic stimulation (rTMS) over the dorsolateral prefrontal cortex (DLPFC) is effective in the treatment of depression in patients with Parkinson disease (PD). However, since research into the effect of this type of rTMS regime on motor function is limited, we studied the effect of rTMS over the DLPFC on the motor functions in PD patients. METHODS: Thirteen patients were randomly assigned into 2 groups, one receiving real-rTMS (90% of resting motor threshold, 10 Hz, 450 pulses-day for 10 consecutive days) over the DLPFC contralateral to the more affected side, and the other group receiving sham-rTMS. Assessment included a clinical motor evaluation using part III of the Unified Parkinson's Disease Rating Scale (UPDRS), and several motor tasks. The UPDRS was applied before and after 10 days of rTMS. Finger tapping, reach movement, grip movement and gait were measured in each session before and after the rTMS over the 10 day period. RESULTS: Statistical analysis (ANOVA for repeated measures; group *day *side *rTMS) only showed a significant effect for finger tapping, reach movement and gait for the factor day. No significant change was reported for the UPDRS in any group. CONCLUSIONS: Application of rTMS over the DLPFC as a 10 day course had no significant effect on motor functions and clinical motor status, and the improvement in performance of motor tasks can be attributed to the effects of practice. SIGNIFICANCE: rTMS over the DLPFC did not lead to any motor improvement in PD patients.  相似文献   
33.
Summary The RPS5 gene has been characterised through its ability to reduce invertase production by the SUC5 gene. In this paper we show that RPS5 acts by maintaining low levels of SUC5 mRNA. We also show that RPS5 acts on the SUC1 and SUC4 genes but not on SUC2 and SUC3, which are members of the SUC family. RPS5 also shows a pleiotropic effect on the amount of mitochondrial cytochromes.  相似文献   
34.
35.
Melatonin reduces nitric oxide synthase activity in rat hypothalamus   总被引:2,自引:0,他引:2  
Abstract: In this report, rat hypothalamic nitric oxide synthase (NOS) activity is shown to be partially inhibited by physiological concentrations of the pineal hormone melatonin. In vitro studies demonstrate that 1 nM melatonin, which approximates the physiological concentration of the hormone at night, significantly inhibited NOS activity. In vivo studies show that administering melatonin or collecting the hypothalamus from animals at night, when endogenous melatonin levels are elevated, results in a significant decrease of NOS activity. Results also show that calmodulin may be involved in this process since its presence in the incubation medium prevents the inhibitory effect of melatonin on NOS activity.  相似文献   
36.
Two patients underwent bilateral radial keratotomy procedures and developed epithelial inclusion cysts as a postoperative complication. Metal blades were used for the corneal incisions; this might be related to the development of the cysts.  相似文献   
37.
38.
A survey was conducted in early 1985 among 366 new mothers at 3 hospitals in Pinar del Rio, Cuba, to assess their level of health information regarding the care of newborns. The 11 study variables included breastfeeding, weaning, bathing the newborn, care of clothing and equipment for the baby, well baby visits, vaccination, accidents and safety, parent-child relations, sex education, and the puerperium. The level of information on these topics was generally low and was adequate only for breastfeeding. The information deficit was not related to urban or rural residence, parity, or educational level. The lack of knowledge of new mothers was attributed to the lack of motivation of health personnel at all levels to provide health education, inadequate use of existing information channels, and a lack of emphasis on health education within the general educational system.  相似文献   
39.
STUDY OBJECTIVE--To assess the impact of a breast clinic on a specific target population and evaluate early diagnosis performance indicators for breast cancer in the presence of a self referral policy. DESIGN--Women living in Florence between 1980 and 1989 who had undergone mammography at a self referral breast clinic were studied. Main outcome measures were the use of mammography in relation to age, symptoms, and the interval between two subsequent tests, and early diagnosis performance indicators were the detection rate (DR), the prevalence/incidence ratio, and the proportion of early detected cancers. Performance indicators were compared with those from formal screening programmes. SETTING--Florence, Italy. PATIENTS--All mammograms performed at the clinic from 1980-89 in 40-69 year old women living in Florence were examined (n = 42,226). Records included the date of birth and of the examination, the reason for testing (asymptomatic/presence of pain/presence of symptoms other than pain), and the TNM classification for breast cancer cases. MAIN RESULTS--The total number of mammograms performed per annum increased by 70% over the decade, but much of this was routine repeat mammography (54.1% in 1989). Rates of first examinations in asymptomatic women increased in the second half of the decade from 17 per 1000 in 1985 to 31 per 1000 in 1989. Mammographic coverage decreased with increasing age from 12.6% in 40-49 year olds to 6.0% in 60-69 years old. Performance indicators of the activity in asymptomatic women were comparable with those expected in service screening. The proportion of not advanced cancers detected in asymptomatic women was 62.3% with a DR of 5.3 per 1000, and the average prevalence/incidence ratio was 2.9. CONCLUSIONS--High quality mammography performed in a breast clinic in self referred asymptomatic women can achieve as good results as a formal invitation screening service. Only a few of these women will benefit, but those who do are likely to be younger (40-49 year old women).  相似文献   
40.
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