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   378436篇
  免费   34860篇
  国内免费   14989篇
耳鼻咽喉   3483篇
儿科学   8568篇
妇产科学   4983篇
基础医学   67120篇
口腔科学   9186篇
临床医学   26640篇
内科学   55122篇
皮肤病学   7614篇
神经病学   25247篇
特种医学   7828篇
外国民族医学   370篇
外科学   35078篇
综合类   54031篇
现状与发展   76篇
预防医学   14736篇
眼科学   6541篇
药学   40397篇
  53篇
中国医学   13290篇
肿瘤学   47922篇
  2024年   582篇
  2023年   5115篇
  2022年   7369篇
  2021年   13866篇
  2020年   12008篇
  2019年   12935篇
  2018年   12796篇
  2017年   13033篇
  2016年   13131篇
  2015年   15264篇
  2014年   25295篇
  2013年   26674篇
  2012年   23338篇
  2011年   26627篇
  2010年   24083篇
  2009年   22756篇
  2008年   21008篇
  2007年   19191篇
  2006年   17540篇
  2005年   15434篇
  2004年   13619篇
  2003年   11672篇
  2002年   9381篇
  2001年   8046篇
  2000年   6660篇
  1999年   5938篇
  1998年   5372篇
  1997年   4885篇
  1996年   4276篇
  1995年   3710篇
  1994年   3268篇
  1993年   2745篇
  1992年   2270篇
  1991年   2099篇
  1990年   1690篇
  1989年   1499篇
  1988年   1373篇
  1987年   1111篇
  1986年   1042篇
  1985年   1633篇
  1984年   1548篇
  1983年   1088篇
  1982年   1179篇
  1981年   932篇
  1980年   795篇
  1979年   653篇
  1978年   492篇
  1977年   370篇
  1976年   320篇
  1975年   192篇
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
11.
12.
《Cancer cell》2022,40(8):835-849.e8
  1. Download : Download high-res image (220KB)
  2. Download : Download full-size image
  相似文献   
13.
14.
15.
The endothelium is a single-layered structure that responds to physical and chemical signals with various factors it synthesizes. In the early days of its discovery, as the inner wall of the vessels, the endothelium was thought to be a simple barrier that lays on the surface. Over time it is discovered that endothelium maintains body homeostasis with the molecules it synthesizes, despite its simple single-layer structure. It has been accepted as an important organ that contributes to the maintenance of vascular tone, cell adhesion, inflammation, vascular permeability and coagulation. Any imbalance in these physiological and pathological events causes endothelial dysfunction. This can cause many diseases such as atherosclerosis, hypertension, diabetes, or it can occur because of these. Endothelial related disorders may also complicate hematopoietic stem cell transplantation (HSCT), which is used to treat various hematologic and neoplastic diseases. These life-threatening complications include graft-versus-host disease, hepatic veno-occlussive disease, transplant-associated thrombotic microangiopathy and diffuse alveolar hemorrhage. They share a similar pathophysiology involving endothelial cells with different clinical presentations. Therefore, current researche on the issue is putting the endothelium under the spotlight for novel markers and treatment options that should be used to monitor or treat at least some of these complications following HSCT.  相似文献   
16.
17.
18.
Patients undergoing sentinel node biopsy (SLNB) for early oral squamous cell carcinoma (OSCC) who harbour occult metastases (pN+ve) may be at greater risk of mortality due to prolonged overall treatment times than those identified as pN+ve on elective neck dissection (ELND). A retrospective comparative survival analysis was therefore undertaken to test this hypothesis. Patients were identified from the South Glasgow multidisciplinary team (MDT) database. Group 1 comprised 38 patients identified as pN+ve, or who were false negative, on sentinel lymph node biopsy (SLNB). Group 2 comprised 146 patients staged pN+ve on ELND. The groups were compared with the Kaplan Meier method and Cox proportional hazards model. In addition, a matched-pair analysis was performed. A unique and specifically designed algorithm was deployed to optimise the pairings. No difference in disease-specific or overall survival was found between the groups. Patients undergoing SLNB as the initial neck staging modality in early OSCC and are identified as pN+ve do not appear to be at a survival disadvantage compared with those staged with ELND.  相似文献   
19.
Transfusion transmissible infections (TTIs) have been a public health challenge for the accessibility, quality and safety of blood transfusion. The present study aimed to consider the prevalence and the trends of hepatitis B virus (HBV), hepatitis C virus (HCV), Human T-cell leukemia virus type 1 (HTLV-1), human immunodeficiency virus (HIV) and syphilis across the ten years among retrospective blood donors. A retrospective investigation of blood donors’ data covering the period from 22 May 2009 to 22 May 2019 was done. Data was accumulated and analyzed from Blood Transfusion Center records, pertaining to all donors who were screened for various TTIs using respective immunological techniques. Out of the 682,171 screened donors in the 2009–2019 study period, 2470 (0.36 %) were infected with at least one infectious agent. The overall prevalence of HBV, HCV, HTLV-1, HIV and syphilis were 1700 (0.25 %), 184 (0.027 %), 335 (0.05 %), 4 (0.0.05 %) and 247 (0.036 %), respectively. The study showed male dominated donor pool (96.79 %) with higher prevalence (0.34 %) of TTIs compared to female donors (0.02 %) with 3.21 % population. Despite the low prevalence of TTIs in our study, HBV, HCV, syphilis and HIV have remained a big threat to safe blood transfusion in Iran. Strict adherence to selection criteria, algorithm of donor screening, use of highly sensitive and specific methods for detection of TTIs, regular consultation and health education programs, prevention and sanitization strategies to reduce the risk of TTIs are recommended to reduce the risk of TTIs and ensure the safety of blood transfusion for recipient.  相似文献   
20.
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