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   24777篇
  免费   1817篇
  国内免费   109篇
耳鼻咽喉   228篇
儿科学   709篇
妇产科学   554篇
基础医学   3710篇
口腔科学   898篇
临床医学   2218篇
内科学   5565篇
皮肤病学   488篇
神经病学   2788篇
特种医学   691篇
外国民族医学   2篇
外科学   2627篇
综合类   113篇
一般理论   6篇
预防医学   1752篇
眼科学   426篇
药学   1816篇
中国医学   111篇
肿瘤学   2001篇
  2023年   214篇
  2022年   469篇
  2021年   810篇
  2020年   462篇
  2019年   743篇
  2018年   869篇
  2017年   664篇
  2016年   715篇
  2015年   884篇
  2014年   1026篇
  2013年   1316篇
  2012年   1935篇
  2011年   2035篇
  2010年   1063篇
  2009年   985篇
  2008年   1537篇
  2007年   1504篇
  2006年   1408篇
  2005年   1293篇
  2004年   1120篇
  2003年   1056篇
  2002年   957篇
  2001年   298篇
  2000年   309篇
  1999年   285篇
  1998年   178篇
  1997年   166篇
  1996年   121篇
  1995年   118篇
  1994年   99篇
  1993年   75篇
  1992年   192篇
  1991年   202篇
  1990年   158篇
  1989年   161篇
  1988年   153篇
  1987年   137篇
  1986年   134篇
  1985年   103篇
  1984年   81篇
  1983年   74篇
  1982年   38篇
  1981年   40篇
  1980年   32篇
  1979年   62篇
  1978年   31篇
  1977年   32篇
  1976年   38篇
  1973年   43篇
  1972年   31篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Introduction: Pharmacovigilance is essential to monitoring the safety profiles of authorized medicines. Compared with small-molecule drugs, biological drugs are more complex, more susceptible to structural variability due to manufacturing processes, and have the potential to induce immune-related reactions, underscoring the importance of safety monitoring for these products. Although highly similar to reference products, biosimilars are not expected to be structurally identical. For these reasons, proper reporting of potential adverse drug reactions (ADRs) using distinguishable names and batch numbers is essential for accurate tracing of all biological drugs. To address the need for robust pharmacovigilance, the European Parliament and Council of the European Union provided legislation regarding pharmacovigilance of biologics in 2010.

Areas covered: This narrative review examines the current state of pharmacovigilance for biologics in the European Union (EU) and discusses relevant information on pharmacovigilance of biosimilars, the current EU pharmacovigilance system, and areas that could be improved.

Expert opinion: Although steps have been taken to improve pharmacovigilance of biologics in the EU, several enhancements can still be made, including additional training for healthcare professionals on ADR reporting, the use of 2D barcodes that enhance traceability, and an open discussion of potentially missed opportunities in the pharmacovigilance of biosimilars.  相似文献   

2.

Objective

Comparative survival between neoadjuvant chemotherapy and adjuvant chemotherapy for patients with cT2-4N0-1M0 non–small cell lung cancer has not been extensively studied.

Methods

Patients with cT2-4N0-1M0 non–small cell lung cancer who received platinum-based chemotherapy were retrospectively identified. Exclusion criteria included stage IV disease, induction radiotherapy, and targeted therapy. The primary end point was disease-free survival. Secondary end points were overall survival, chemotherapy tolerance, and ability of Response Evaluation Criteria In Solid Tumors response to predict survival. Survival was estimated using the Kaplan–Meier method, compared using the log-rank test and Cox proportional hazards models, and stratified using matched pairs after propensity score matching.

Results

In total, 330 patients met the inclusion criteria (n = 92/group after propensity-score matching; median follow-up, 42 months). Five-year disease-free survival was 49% (95% confidence interval, 39-61) for neoadjuvant chemotherapy versus 48% (95% confidence interval, 38-61) for adjuvant chemotherapy (P = .70). On multivariable analysis, disease-free survival was not associated with neoadjuvant chemotherapy or adjuvant chemotherapy (hazard ratio, 1.1; 95% confidence interval, 0.64-1.90; P = .737), nor was overall survival (hazard ratio, 1.21; 95% confidence interval, 0.63-2.30; P = .572). The neoadjuvant chemotherapy group was more likely to receive full doses and cycles of chemotherapy (P = .014/0.005) and had fewer grade 3 or greater toxicities (P = .001). Response Evaluation Criteria In Solid Tumors response to neoadjuvant chemotherapy was associated with disease-free survival (P = .035); 15% of patients receiving neoadjuvant chemotherapy (14/92) had a major pathologic response.

Conclusions

Timing of chemotherapy, before or after surgery, is not associated with an improvement in overall or disease-free survival among patients with cT2-4N0-1M0 non–small cell lung cancer who undergo complete surgical resection.  相似文献   
3.
ABSTRACT

Introduction

Glucocorticoid (GC) induced osteoporosis (GIOP) is the most common form of secondary osteoporosis. It develops in a dose and time dependent manner, due to a rapid and transient increase in bone resorption, followed by the inhibition of bone formation.  相似文献   
4.
Ana Lopez Alonso 《Platelets》2015,26(4):317-323
Abstract

While the interactions between Gram-positive bacteria and platelets have been well characterized, there is a paucity of data on the interaction between other pathogens and platelets. However, thrombocytopenia is a common feature with many infections especially viral hemorrhagic fever. The little available data on these interactions indicate a similarity with bacteria-platelet interactions with receptors such as FcγRIIa and Toll-Like Receptors (TLR) playing key roles with many pathogens. This review summarizes the known interactions between platelets and pathogens such as viruses, fungi and parasites.  相似文献   
5.
6.
7.
8.
In the work described here, our aim was to determine, in an elderly population, changes in muscle thickness (MT), cross-sectional area (CSA) and echo intensity (EI) of the quadriceps muscles at four time points (0, 5, 10 and 15 min; i.e., T0, T5, T10 and T15, respectively) after changing from a standing to supine position. Twenty-one elderly participants (14 men: 68.1 ± 4.6 y; 8 women: 66.8 ± 4.1 y) were evaluated at four time points. Rectus femoris CSA (RFCSA), MT and EI of the quadriceps femoris (QF) muscles were assessed. EI significantly increased from T0 to T5, T10 and T15 (p < 0.001), whereas no differences were observed between T5 and T15 in the rectus femoris (RFEI), vastus intermedius (VIEI) and quadriceps femoris (QFEI). No differences were observed between any time points in the RFCSA and MT of QF muscles. In summary, these results suggest that periods >5 min are not necessary to obtain consistent MT and EI measurements of quadriceps femoris muscles in the elderly population.  相似文献   
9.
10.
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