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   2560526篇
  免费   212760篇
  国内免费   7651篇
耳鼻咽喉   34470篇
儿科学   84652篇
妇产科学   72147篇
基础医学   357551篇
口腔科学   74514篇
临床医学   229870篇
内科学   508445篇
皮肤病学   58452篇
神经病学   209845篇
特种医学   104212篇
外国民族医学   720篇
外科学   394903篇
综合类   63428篇
现状与发展   5篇
一般理论   911篇
预防医学   203947篇
眼科学   57179篇
药学   187334篇
  7篇
中国医学   4441篇
肿瘤学   133904篇
  2018年   25037篇
  2016年   22785篇
  2015年   26005篇
  2014年   36141篇
  2013年   54746篇
  2012年   70209篇
  2011年   74746篇
  2010年   45550篇
  2009年   43916篇
  2008年   70798篇
  2007年   75105篇
  2006年   76619篇
  2005年   74285篇
  2004年   72177篇
  2003年   69571篇
  2002年   67003篇
  2001年   119983篇
  2000年   123544篇
  1999年   103672篇
  1998年   28778篇
  1997年   25826篇
  1996年   26456篇
  1995年   27676篇
  1994年   26005篇
  1993年   24432篇
  1992年   86852篇
  1991年   84721篇
  1990年   82021篇
  1989年   78918篇
  1988年   73398篇
  1987年   72302篇
  1986年   68477篇
  1985年   66220篇
  1984年   50143篇
  1983年   42700篇
  1982年   25966篇
  1981年   23320篇
  1980年   21942篇
  1979年   46811篇
  1978年   33226篇
  1977年   28076篇
  1976年   26136篇
  1975年   27569篇
  1974年   33240篇
  1973年   31964篇
  1972年   29461篇
  1971年   27537篇
  1970年   25267篇
  1969年   23743篇
  1968年   21832篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
Modified-release opioids are often prescribed for the management of moderate to severe acute pain following total hip and knee arthroplasty, despite recommendations against their use due to increasing concerns regarding harm. The primary objective of this multicentre study was to examine the impact of modified-release opioid use on the incidence of opioid-related adverse events compared with immediate-release opioid use, among adult inpatients following total hip or knee arthroplasty. Data for total hip and knee arthroplasty inpatients receiving an opioid analgesic for postoperative analgesia during hospitalisation were collected from electronic medical records of three tertiary metropolitan hospitals in Australia. The primary outcome was the incidence of opioid-related adverse events during hospital admission. Patients who received modified with or without immediate-release opioids were matched to those receiving immediate-release opioids only (1:1) using nearest neighbour propensity score matching with patient and clinical characteristics as covariates. This included total opioid dose received. In the matched cohorts, patients given modified-release opioids (n = 347) experienced a higher incidence of opioid-related adverse events overall, compared with those given immediate-release opioids only (20.5%, 71/347 vs. 12.7%, 44/347; difference in proportions 7.8% [95%CI 2.3–13.3%]). Modified-release opioid use was associated with an increased risk of harm when used for acute pain during hospitalisation after total hip or knee arthroplasty.  相似文献   
3.
4.
5.
Oral squamous cell carcinomas (OSCCs) develop in genetically altered epithelium in the mucosal lining, also coined as fields, which are mostly not visible but occasionally present as white oral leukoplakia (OL) lesions. We developed a noninvasive genetic assay using next-generation sequencing (NGS) on brushed cells to detect the presence of genetically altered fields, including those that are not macroscopically visible. The assay demonstrated high accuracy in OL patients when brush samples were compared with biopsies as gold standard. In a cohort of Fanconi anemia patients, detection of mutations in prospectively collected oral brushes predicted oral cancer also when visible abnormalities were absent. We further provide insight in the molecular landscape of OL with frequent changes of TP53, FAT1 and NOTCH1. NGS analysis of noninvasively collected samples offers a highly accurate method to detect genetically altered fields in the oral cavity, and predicts development of OSCC in high-risk individuals. Noninvasive genetic screening can be employed to screen high-risk populations for cancer and precancer, map the extension of OL lesions beyond what is visible, map the oral cavity for precancerous changes even when visible abnormalities are absent, test accuracy of promising imaging modalities, monitor interventions and determine genetic progression as well as the natural history of the disease in the human patient.  相似文献   
6.
7.
8.
Cyclotron-produced copper-64 radioisotope tracers offer the possibility to perform both diagnostic investigation by positron emission tomography (PET) and radiotherapy by a theranostic approach with bifunctional chelators. The versatile chemical properties of copper add to the importance of this isotope in medicinal investigation. [64Cu][Cu (ATSM)] has shown to be a viable candidate for imaging of tumor hypoxia; a critical tumor microenvironment characteristic that typically signifies tumor progression and resistance to chemo-radiotherapy. Various production and radiosynthesis methods of [64Cu][Cu (ATSM)] exist in labs, but usually involved non-standardized equipment with varying production qualities and may not be easily implemented in wider hospital settings. [64Cu][Cu (ATSM)] was synthesized on a modified GE TRACERlab FXN automated synthesis module. End-of-synthesis (EOS) molar activity of [64Cu][Cu (ATSM)] was 2.2–5.5 Ci/μmol (HPLC), 2.2–2.6 Ci/μmol (ATSM-titration), and 3.0–4.4 Ci/μmol (ICP-MS). Radiochemical purity was determined to be >99% based on radio-HPLC. The final product maintained radiochemical purity after 20 h. We demonstrated a simple and feasible process development and quality control protocols for automated cyclotron production and synthesis of [64Cu][Cu (ATSM)] based on commercially distributed standardized synthesis modules suitable for PET imaging and theranostic studies.  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