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   9061篇
  免费   680篇
  国内免费   31篇
耳鼻咽喉   91篇
儿科学   248篇
妇产科学   151篇
基础医学   1587篇
口腔科学   347篇
临床医学   747篇
内科学   1791篇
皮肤病学   110篇
神经病学   670篇
特种医学   297篇
外科学   1410篇
综合类   49篇
一般理论   3篇
预防医学   607篇
眼科学   57篇
药学   1010篇
中国医学   9篇
肿瘤学   588篇
  2021年   96篇
  2020年   104篇
  2019年   109篇
  2018年   133篇
  2017年   144篇
  2016年   123篇
  2015年   171篇
  2014年   197篇
  2013年   326篇
  2012年   421篇
  2011年   473篇
  2010年   262篇
  2009年   255篇
  2008年   413篇
  2007年   436篇
  2006年   445篇
  2005年   397篇
  2004年   353篇
  2003年   401篇
  2002年   389篇
  2001年   268篇
  2000年   309篇
  1999年   278篇
  1998年   133篇
  1997年   125篇
  1996年   92篇
  1995年   110篇
  1994年   102篇
  1993年   90篇
  1992年   238篇
  1991年   226篇
  1990年   215篇
  1989年   200篇
  1988年   162篇
  1987年   188篇
  1986年   148篇
  1985年   146篇
  1984年   134篇
  1983年   111篇
  1982年   80篇
  1981年   64篇
  1980年   54篇
  1979年   98篇
  1978年   95篇
  1977年   61篇
  1976年   52篇
  1975年   39篇
  1974年   57篇
  1973年   42篇
  1972年   41篇
排序方式: 共有9772条查询结果,搜索用时 15 毫秒
1.
BackgroundLittle is known of possible gender differences in treatment of periampullary tumours and outcome after pancreatoduodenectomy (PD), and the aim of this study was therefore to investigate any variances from national multicentre perspective.MethodsData from the Swedish National Registry for Pancreatic and Periampullary Cancer for all patients diagnosed with a periampullary tumour from 2012 throughout 2017 was collected. The material was analysed in two groups, men and women, for palliative treatment and curative intended resection.ResultsA total of 5677 patients were included, 2906 (51%) men and 2771 (49%) women. Women were older than men, 72 (65–78) years vs. 70 (64–76), p < 0.001. A lesser proportion of women were planned for resection (1131 (41%) vs. 1288 (44%), p = 0.008), but after adjusting for age and tumour location no difference was seen. Postoperative morbidity was equal, but women had significantly better long-term survival than men. The survival was equal for palliative men and women.ConclusionNo gender bias could be established when analysing treatment for periampullary tumours in Sweden, even though less women were offered surgery. Data suggest that even though women were older they tolerate surgery well and hence offering PD at a higher age for women could be suggested.  相似文献   
2.
3.
Peacekeeping missions involve experiences that may impact the mental health of participating soldiers. However, research on the long-term mental health consequences of peacekeeping is sparse. The present study aimed to find the prevalence of mental health problems (MHPs), possible MHP predictors, and associations between predictors and MHPs in Norwegian peacekeepers 18–38 years after deployment to a United Nations peacekeeping mission. We used data from a cross-sectional, postdeployment survey of Norwegian peacekeepers who served in Lebanon between 1978 and 1998 (N = 10,605). Participants were assessed for posttraumatic stress disorder (PTSD); anxiety; depression; insomnia; alcohol misuse; drug misuse; and exposure to pre-, peri-, and postdeployment stressors. Logistic regressions were executed to explore key variables associated with MHPs. Total MHP prevalence was 15.1%, 95% CI [14.4, 15.8]. The estimates for specific disorders were 0.1% for drug misuse, 3.4% for alcohol misuse, 4.0% for depression, 6.2% for PTSD, 6.4% for anxiety, and 9.3% for insomnia. Postdeployment stressors, OR = 1.91, 95% CI [1.79, 2.04]; employment status, OR = 1.41, 95% CI [1.33, 1.48]; and traumatic exposure during deployment, OR = 1.11, 95% CI [1.09, 1.12], were positively related to PTSD, χ2(17, N = 8,568) = 1,791.299, p < .001. Similar patterns were found for the other MHPs. Considering that most participants (84.9%) reported low symptom levels, our findings challenge the widespread public perception that most peacekeepers have MHPs. Moreover, our results indicate that future peacekeepers should be prepared for challenges they may face not only during deployment but also in the years following their homecoming.  相似文献   
4.
5.
Increased expression of GLI1, the main Hedgehog signalling pathway effector, is related to unfavourable prognosis and progressive disease of certain breast cancer subtypes. We used conditional transgenic mice induced to overexpress GLI1 in the mammary epithelium either alone or in combination with deletion of one Trp53 allele to address the role of elevated GLI1 expression in breast tumour initiation and progression. Induced GLI1 expression facilitates mammary gland tumour formation and this was further increased upon heterozygous deletion of Trp53. The GLI1-induced primary tumours were of different murine molecular subtypes, including Normal-likeEx, Class8Ex, Claudin-LowEx and Erbb2-likeEx. The gene expression profiles of some of the tumours correlated well with the PAM50 subtypes for human breast cancer. Whole-exome sequencing revealed somatic mutation profiles with only little overlap between the primary tumours. Orthotopically serially transplanted GLI1-induced tumours maintained the main morphological characteristics of the primary tumours for ≥10 generations. Independent of Trp53 status and molecular subtype, the serially transplanted GLI1-induced tumours were able to grow both in the absence of transgenic GLI1 expression and in the presence of the GLI1 inhibitor GANT61. These data suggest that elevated GLI1 expression has a determinant role in tumour initiation; however, additional genetic events are required for tumour progression.  相似文献   
6.
Abstract The aim of the present clinical trial was to test tolerability during 2 treatments with EMDOGAIN® in a large number of patients. An open, controlled study design in 10 Swedish specialist clinics was chosen, with a test group of 107 patients treated with EMDOGAIN® in connection with periodontal surgery at 2 surgical test sites per patient. The procedures were performed 2 to 6 weeks apart on one-rooted teeth with at least 4 mm deep intraosseous lesions. A control group of 33 patients underwent flap surgery without EMDOGAIN® at I comparable site. In total 214 test and 33 control surgeries were performed. Serum samples were obtained from test patients for analysis of total and specific antibody levels. 10 of the patients had samples taken before and after the first surgery. 56 other samples were taken after one treatment with EMDOGAIN®, and 63 after 2 treatments. None of the samples, not even from allergy-prone patients after 2 treatments, indicated deviations from established baseline ranges. This indicates that the immunogenic potential of EMDOGAIN® is extremely low when applied in conjunction with periodontal surgery. Comparison between the test and control groups demonstrated the same type and frequency of post-surgical experiences, i.e., reactions caused by the surgical procedure itself. Clinical probing and radiographic evaluation was performed at baseline and 8 months postsurgery. About half of the patients (44 test and 21 control) were also evaluated after 3 years. There was a significant difference between the test and control results at 8 months post surgery. and this difference had increased further at the 3 year follow-up. The 2.5–3 mm increase in attachment and bone level after treatment with EMDOGAIN® was of the same magnitude as seen in the studies with split-mouth design aiming for lest of effectiveness of EMDOGAIN®.  相似文献   
7.
8.
Different psychotropic drugs were investigated in order to determine their effect on the release of prolactin and corticosterone and their influence on the tuberoinfundibular dopamine (TIDA) neuron activity. The results were used in a principal component analysis, which grouped the psychotropic drugs into different clusters. In the plot showing these clusters the anxiolytic drugs were found to be grouped together and differ from the antidepressant drugs by their potent ability to increase plasma corticosterone. The antipsychotic drugs formed a separate group being clustered together. Typical neuroleptic and atypical antipsychotic drugs could be separated within the cluster by their different effects on plasma prolactin and corticosterone and on TIDA neuron activity. The results indicate that the neuroendocrine profiles of antidepressant and anxiolytic drugs are different from those of antipsychotic drugs and that the neuroendocrine measurements could be a useful tool in the early classification of psychotropic drugs. © 1993 Wiley-Liss, Inc.  相似文献   
9.
Compromise of immune function in obstructive jaundice.   总被引:5,自引:0,他引:5  
  相似文献   
10.

Background  

A standardised suction technique has been used to sample plasma proteins in dermal interstitial fluid (IF) serially for 5 to 6 days from a suction-induced skin mini-erosion. Increased protein concentrations ascribed to inflammation have been shown from day 1 onward. In this study, we assessed the effect of two different extraction pressures on IF sample composition.  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