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   69504篇
  免费   5087篇
  国内免费   256篇
耳鼻咽喉   853篇
儿科学   1958篇
妇产科学   1599篇
基础医学   9066篇
口腔科学   1425篇
临床医学   9034篇
内科学   14149篇
皮肤病学   926篇
神经病学   6326篇
特种医学   1738篇
外科学   8886篇
综合类   1103篇
一般理论   78篇
预防医学   7125篇
眼科学   1318篇
药学   4349篇
中国医学   144篇
肿瘤学   4770篇
  2023年   316篇
  2022年   573篇
  2021年   1344篇
  2020年   781篇
  2019年   1351篇
  2018年   1559篇
  2017年   1163篇
  2016年   1184篇
  2015年   1422篇
  2014年   2171篇
  2013年   3201篇
  2012年   4798篇
  2011年   4966篇
  2010年   2733篇
  2009年   2433篇
  2008年   4559篇
  2007年   4699篇
  2006年   4857篇
  2005年   4670篇
  2004年   4445篇
  2003年   4351篇
  2002年   4051篇
  2001年   606篇
  2000年   540篇
  1999年   742篇
  1998年   910篇
  1997年   756篇
  1996年   690篇
  1995年   582篇
  1994年   545篇
  1993年   489篇
  1992年   465篇
  1991年   408篇
  1990年   384篇
  1989年   364篇
  1988年   328篇
  1987年   308篇
  1986年   291篇
  1985年   301篇
  1984年   380篇
  1983年   347篇
  1982年   406篇
  1981年   369篇
  1980年   318篇
  1979年   239篇
  1978年   224篇
  1977年   220篇
  1976年   168篇
  1974年   190篇
  1973年   166篇
排序方式: 共有10000条查询结果,搜索用时 21 毫秒
1.
2.
Introduction: The landscape of poly (ADP-ribose) polymerase (PARP) inhibition in ovarian cancer is rapidly evolving and becoming increasingly complex. Ovarian cancer is leading therapeutic innovation by providing the proof of concept for DNA repair as a target. Three different PARP inhibitors have now received approvals in the US and Europe in different indications. Subtle but crucial differences can be found among the licensed indications for each PARP inhibitor in terms of histology, type of BRCA mutation (germline and/or somatic), number of prior lines of chemotherapy and whether the indication is in the treatment or maintenance settings.

Areas covered: We review the latest clinical data regarding the PARP inhibitor rucaparib in ovarian cancer, provide an update on the evolving landscape of PARP inhibition in ovarian cancer, and summarize avenues of ongoing and future research.

Expert opinion: All eligible patients should be offered a PARP inhibitor. SOLO1 trial results demonstrated an unprecedented benefit maintenance with PARP inhibitors in first line. Results from trials evaluating PARP inhibitors as maintenance in first line regardless of BRCA status and from trials evaluating combinatorial strategies are eagerly awaited.  相似文献   

3.
Prevalence of osteoporosis is more than 50% in older adults, yet current clinical methods for diagnosis that rely on areal bone mineral density (aBMD) fail to detect most individuals who have a fragility fracture. Bone fragility can manifest in different forms, and a “one-size-fits-all” approach to diagnosis and management of osteoporosis may not be suitable. High-resolution peripheral quantitative computed tomography (HR-pQCT) provides additive information by capturing information about volumetric density and microarchitecture, but interpretation is challenging because of the complex interactions between the numerous properties measured. In this study, we propose that there are common combinations of bone properties, referred to as phenotypes, that are predisposed to different levels of fracture risk. Using HR-pQCT data from a multinational cohort (n = 5873, 71% female) between 40 and 96 years of age, we employed fuzzy c-means clustering, an unsupervised machine-learning method, to identify phenotypes of bone microarchitecture. Three clusters were identified, and using partial correlation analysis of HR-pQCT parameters, we characterized the clusters as low density, low volume, and healthy bone phenotypes. Most males were associated with the healthy bone phenotype, whereas females were more often associated with the low volume or low density bone phenotypes. Each phenotype had a significantly different cumulative hazard of major osteoporotic fracture (MOF) and of any incident osteoporotic fracture (p < 0.05). After adjustment for covariates (cohort, sex, and age), the low density followed by the low volume phenotype had the highest association with MOF (hazard ratio = 2.96 and 2.35, respectively), and significant associations were maintained when additionally adjusted for femoral neck aBMD (hazard ratio = 1.69 and 1.90, respectively). Further, within each phenotype, different imaging biomarkers of fracture were identified. These findings suggest that osteoporotic fracture risk is associated with bone phenotypes that capture key features of bone deterioration that are not distinguishable by aBMD. © 2021 American Society for Bone and Mineral Research (ASBMR).  相似文献   
4.
5.
6.
7.
8.
9.

Background

The purpose of this study was to compare the outcomes of trauma patients who were injured in a motor vehicle crash and tested positive for alcohol upon hospital arrival versus those who tested negative.

Methods

Study data came from the US National Trauma Data Bank (2007–2010). Any blood alcohol concentration (BAC) found at or above the legal limit (≥0.08?g/dL) was considered “alcohol positive”, and if no alcohol was identified through testing, the patient was considered “alcohol negative”. Patients’ demographics including age >?=?14, race, gender, drug test results, systolic blood pressure, heart rate, injury severity score (ISS), and Glasgow Coma Scale (GCS) were included in the study. Propensity score and exact pair matching were performed between the groups using baseline characteristics.

Results

From a total of 88,794 patients, 30.9% tested positive and 69.1% tested negative for alcohol. There were significant differences found between the groups regarding age, gender, race, and GCS (all p?<?0.001) as well as a significantly higher in-hospital mortality rate (3.5% vs. 2.7%, p?<?0.001) and median time to patient expiration (4 vs. 3 days, p?<?0.001) in the alcohol negative group. After running both matching scenarios, there was no evidence of a significant difference seen in the rates of in-hospital mortality or the median time to patient expiration between the alcohol groups in either matched comparison.

Conclusion

Patients who tested positive for alcohol following a traumatic motor vehicle crash showed no significant increase in in-hospital mortality or time to expiration when compared to propensity score and exact matched patients who tested negative for alcohol.  相似文献   
10.
Tuberculosis (TB) remains one of a major health problem worldwide. Tuberculosis vaccine research has made an extraordinary progress over the past few years. However, there is still no replacement for the Bacillus Calmette‐Guérin vaccine, the only TB vaccine licensed for human use. Therefore, the discovery and development of new TB vaccines remains a priority. This article discusses current strategies used to diversify TB vaccines and includes discussion of the status of efforts to improve protection against Mycobacterium tuberculosis (M tb) infection or TB disease by developing new and safe TB vaccines. This article also highlights the current research efforts in immune‐enhancing approaches to improve vaccination efficacy. The development of more effective TB vaccines might have significant impact on global TB control.  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