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   1622059篇
  免费   134993篇
  国内免费   2694篇
耳鼻咽喉   22081篇
儿科学   53396篇
妇产科学   46596篇
基础医学   229865篇
口腔科学   48216篇
临床医学   142224篇
内科学   318965篇
皮肤病学   34767篇
神经病学   132239篇
特种医学   66319篇
外国民族医学   475篇
外科学   248202篇
综合类   39768篇
现状与发展   3篇
一般理论   550篇
预防医学   122990篇
眼科学   37009篇
药学   122910篇
  2篇
中国医学   2939篇
肿瘤学   90230篇
  2018年   15295篇
  2016年   13477篇
  2015年   15570篇
  2014年   21354篇
  2013年   32232篇
  2012年   44003篇
  2011年   46240篇
  2010年   27242篇
  2009年   26070篇
  2008年   44326篇
  2007年   46771篇
  2006年   47418篇
  2005年   45996篇
  2004年   45438篇
  2003年   43379篇
  2002年   42558篇
  2001年   76731篇
  2000年   79366篇
  1999年   67089篇
  1998年   17088篇
  1997年   15667篇
  1996年   15578篇
  1995年   16220篇
  1994年   15266篇
  1993年   14411篇
  1992年   56230篇
  1991年   54508篇
  1990年   53271篇
  1989年   51514篇
  1988年   47875篇
  1987年   47196篇
  1986年   44837篇
  1985年   43395篇
  1984年   32367篇
  1983年   27822篇
  1982年   16214篇
  1981年   14499篇
  1980年   13589篇
  1979年   30676篇
  1978年   21195篇
  1977年   17860篇
  1976年   16782篇
  1975年   17650篇
  1974年   21629篇
  1973年   20799篇
  1972年   18985篇
  1971年   17916篇
  1970年   16409篇
  1969年   15405篇
  1968年   14068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.
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   
5.
6.
7.
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   
8.
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