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   144703篇
  免费   11215篇
  国内免费   552篇
耳鼻咽喉   1492篇
儿科学   3963篇
妇产科学   2826篇
基础医学   20504篇
口腔科学   2768篇
临床医学   15079篇
内科学   30289篇
皮肤病学   2649篇
神经病学   16048篇
特种医学   5267篇
外国民族医学   6篇
外科学   18514篇
综合类   1617篇
一般理论   131篇
预防医学   13013篇
眼科学   2303篇
药学   9730篇
中国医学   194篇
肿瘤学   10077篇
  2023年   1105篇
  2022年   832篇
  2021年   3734篇
  2020年   2584篇
  2019年   3708篇
  2018年   4409篇
  2017年   3116篇
  2016年   3609篇
  2015年   4099篇
  2014年   5251篇
  2013年   6862篇
  2012年   10756篇
  2011年   10754篇
  2010年   6024篇
  2009年   5415篇
  2008年   8803篇
  2007年   9248篇
  2006年   8673篇
  2005年   8401篇
  2004年   7748篇
  2003年   6888篇
  2002年   6536篇
  2001年   2032篇
  2000年   1887篇
  1999年   1772篇
  1998年   1308篇
  1997年   1055篇
  1996年   815篇
  1995年   974篇
  1994年   802篇
  1993年   742篇
  1992年   1205篇
  1991年   1129篇
  1990年   1055篇
  1989年   1023篇
  1988年   904篇
  1987年   836篇
  1986年   863篇
  1985年   856篇
  1984年   706篇
  1983年   618篇
  1982年   581篇
  1981年   487篇
  1980年   413篇
  1979年   531篇
  1978年   411篇
  1977年   381篇
  1975年   334篇
  1974年   358篇
  1973年   350篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
5.
Patients admitted to intensive care after cardiac arrest are at risk of circulatory shock and early mortality due to cardiovascular failure. The aim of this study was to evaluate the ability of the veno-arterial pCO2 difference (∆pCO2; central venous CO2 – arterial CO2) and lactate to predict early mortality in postcardiac arrest patients. This was a pre-planned prospective observational sub-study of the target temperature management 2 trial. The sub-study patients were included at five Swedish sites. Repeated measurements of ∆pCO2 and lactate were conducted at 4, 8, 12, 16, 24, 48, and 72 h after randomization. We assessed the association between each marker and 96-h mortality and their prognostic value for 96-h mortality. One hundred sixty-three patients were included in the analysis. Mortality at 96 h was 17%. During the initial 24 h, there was no difference in ∆pCO2 levels between 96-h survivors and non-survivors. ∆pCO2 measured at 4 h was associated with an increased risk of death within 96 h (adjusted odds ratio: 1.15; 95% confidence interval [CI]: 1.02–1.29; p = .018). Lactate levels were associated with poor outcome over multiple measurements. The area under the receiving operating curve to predict death within 96 h was 0.59 (95% CI: 0.48–0.74) and 0.82 (95% CI: 0.72–0.92) for ∆pCO2 and lactate, respectively. Our results do not support the use of ∆pCO2 to identify patients with early mortality in the postresuscitation phase. In contrast, non-survivors demonstrated higher lactate levels in the initial phase and lactate identified patients with early mortality with moderate accuracy.  相似文献   
6.
Surgery smiles     
  相似文献   
7.
8.
Journal of Thrombosis and Thrombolysis - The ongoing controversy regarding optimal reversal agent for factor Xa-inhibitors is mainly due to lack of comparative data of andexanet alfa (AA) to...  相似文献   
9.
The authors define molecular imaging, according to the Society of Nuclear Medicine and Molecular Imaging, as the visualization, characterization, and measurement of biological processes at the molecular and cellular levels in humans and other living systems. Although practiced for many years clinically in nuclear medicine, expansion to other imaging modalities began roughly 25 years ago and has accelerated since. That acceleration derives from the continual appearance of new and highly relevant animal models of human disease, increasingly sensitive imaging devices, high-throughput methods to discover and optimize affinity agents to key cellular targets, new ways to manipulate genetic material, and expanded use of cloud computing. Greater interest by scientists in allied fields, such as chemistry, biomedical engineering, and immunology, as well as increased attention by the pharmaceutical industry, have likewise contributed to the boom in activity in recent years. Whereas researchers and clinicians have applied molecular imaging to a variety of physiologic processes and disease states, here, the authors focus on oncology, arguably where it has made its greatest impact. The main purpose of imaging in oncology is early detection to enable interception if not prevention of full-blown disease, such as the appearance of metastases. Because biochemical changes occur before changes in anatomy, molecular imaging—particularly when combined with liquid biopsy for screening purposes—promises especially early localization of disease for optimum management. Here, the authors introduce the ways and indications in which molecular imaging can be undertaken, the tools used and under development, and near-term challenges and opportunities in oncology.  相似文献   
10.
Hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer is defined by the presence of the estrogen receptor and/or the progesterone receptor and the absence of HER2 gene amplification. HR-positive/HER2-negative breast cancer accounts for 65%–70% of all breast cancers, and incidence increases with increasing age. Treatment varies by stage, and endocrine therapy is the mainstay of treatment in both early stage and late-stage disease. Combinations with cyclin-dependent kinase 4/6 inhibitors have reduced distant recurrence in the early stage setting and improved overall survival in the metastatic setting. Chemotherapy is used based on stage and tumor biology in the early stage setting and after endocrine resistance for advanced disease. New therapies, including novel endocrine agents and antibody-drug conjugates, are now changing the treatment landscape. With the availability of new treatment options, it is important to define the optimal sequence of treatment to maximize clinical benefit while minimizing toxicity. In this review, the authors first discuss the pathologic and molecular features of HR-positive/HER2-negative breast cancer and mechanisms of endocrine resistance. Then, they discuss current and emerging therapies for both early stage and metastatic HR-positive/HER2-negative breast cancer, including treatment algorithms based on current data.  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