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   10288篇
  免费   559篇
  国内免费   40篇
耳鼻咽喉   171篇
儿科学   353篇
妇产科学   247篇
基础医学   1374篇
口腔科学   222篇
临床医学   759篇
内科学   2550篇
皮肤病学   429篇
神经病学   770篇
特种医学   359篇
外科学   1454篇
综合类   41篇
一般理论   2篇
预防医学   804篇
眼科学   149篇
药学   526篇
中国医学   46篇
肿瘤学   631篇
  2023年   60篇
  2022年   143篇
  2021年   336篇
  2020年   124篇
  2019年   288篇
  2018年   375篇
  2017年   194篇
  2016年   183篇
  2015年   232篇
  2014年   384篇
  2013年   454篇
  2012年   488篇
  2011年   556篇
  2010年   330篇
  2009年   357篇
  2008年   456篇
  2007年   485篇
  2006年   470篇
  2005年   491篇
  2004年   504篇
  2003年   506篇
  2002年   474篇
  2001年   349篇
  2000年   393篇
  1999年   308篇
  1998年   84篇
  1997年   66篇
  1996年   80篇
  1995年   58篇
  1994年   53篇
  1993年   49篇
  1992年   175篇
  1991年   142篇
  1990年   146篇
  1989年   129篇
  1988年   126篇
  1987年   109篇
  1986年   93篇
  1985年   85篇
  1984年   66篇
  1983年   41篇
  1982年   23篇
  1979年   48篇
  1978年   24篇
  1977年   24篇
  1976年   28篇
  1975年   36篇
  1974年   41篇
  1972年   28篇
  1969年   23篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
Recombinant human alpha lymphotoxin (rLT) administered intravenously to Lewis rats induces peripheral neutrophilia and lymphopenia in a dose-response dependent fashion. A dose of 30,000 units of rLT induced a neutrophilia (1589 +/- 326 to 5554 +/- 1050 neutrophils/cu mm) and lymphopenia (10,368 +/- 992 to 4636 +/- 878 lymphocytes/cu mm) at 2 hours after injection that was highly significant (P less than 0.001 and P less than 0.001, respectively) in comparison with vehicle controls. The kinetics of the neutrophilia that peaked at 2 hours as well as of the lymphopenia were highly reminiscent of the neutrophilia and lymphopenia following intravenous administration of either recombinant human interleukin-1 (IL-1) alpha or beta to rats. The peripheral neutrophilia was accompanied by a significant depletion of bone marrow neutrophils (P less than 0.001), as is also known to occur after administration of IL-1. Systemic blood pressure was not affected by rLT, which suggested that the changes in circulating leukocyte subsets were not attributable to hemodynamic changes nor to the hemodynamic-change-related release of adrenal hormones. Adrenalectomy did not alter the rLT-induced neutrophilia or lymphopenia, which suggested that rLT does not mediate its hematologic effects on peripheral blood leukocytes via the release of adrenal hormones. Pretreatment of rats with dexamethasone, indomethacin, or aspirin also did not alter rLT-induced neutrophilia or lymphopenia, which suggested that rLT-induced hematologic effects were not mediated via arachidonic acid metabolites, in stark contrast to IL-1 induced neutrophilia, which is inhibited by both dexamethasone and indomethacin.  相似文献   
22.
23.
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   
24.
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   
25.
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   
26.
27.
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   
28.
29.
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   
30.
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