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   2304380篇
  免费   181245篇
  国内免费   3654篇
耳鼻咽喉   31987篇
儿科学   71452篇
妇产科学   64176篇
基础医学   327196篇
口腔科学   70022篇
临床医学   202604篇
内科学   447997篇
皮肤病学   49228篇
神经病学   183636篇
特种医学   92255篇
外国民族医学   541篇
外科学   359710篇
综合类   53733篇
现状与发展   3篇
一般理论   754篇
预防医学   170253篇
眼科学   53305篇
药学   176853篇
  5篇
中国医学   4576篇
肿瘤学   128993篇
  2018年   21551篇
  2016年   18748篇
  2015年   21661篇
  2014年   29820篇
  2013年   44956篇
  2012年   61099篇
  2011年   64236篇
  2010年   37950篇
  2009年   36332篇
  2008年   61955篇
  2007年   65308篇
  2006年   66538篇
  2005年   64576篇
  2004年   63273篇
  2003年   60484篇
  2002年   59299篇
  2001年   115645篇
  2000年   119780篇
  1999年   100796篇
  1998年   24693篇
  1997年   22166篇
  1996年   22133篇
  1995年   22524篇
  1994年   21025篇
  1993年   19708篇
  1992年   81731篇
  1991年   79122篇
  1990年   77051篇
  1989年   74775篇
  1988年   68982篇
  1987年   67817篇
  1986年   64127篇
  1985年   61964篇
  1984年   45431篇
  1983年   38984篇
  1982年   21994篇
  1981年   19515篇
  1980年   18159篇
  1979年   42501篇
  1978年   29101篇
  1977年   24712篇
  1976年   22726篇
  1975年   24391篇
  1974年   29720篇
  1973年   28492篇
  1972年   26472篇
  1971年   24935篇
  1970年   23253篇
  1969年   21845篇
  1968年   19914篇
排序方式: 共有10000条查询结果,搜索用时 15 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