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   1391922篇
  免费   104450篇
  国内免费   1937篇
耳鼻咽喉   18259篇
儿科学   45366篇
妇产科学   37945篇
基础医学   205960篇
口腔科学   41548篇
临床医学   127419篇
内科学   275299篇
皮肤病学   30771篇
神经病学   112691篇
特种医学   51014篇
外国民族医学   288篇
外科学   195067篇
综合类   26939篇
现状与发展   4篇
一般理论   620篇
预防医学   118556篇
眼科学   30597篇
药学   100764篇
  6篇
中国医学   2545篇
肿瘤学   76651篇
  2021年   11312篇
  2019年   12952篇
  2018年   17671篇
  2017年   13441篇
  2016年   14203篇
  2015年   16489篇
  2014年   22649篇
  2013年   33329篇
  2012年   46699篇
  2011年   49639篇
  2010年   27910篇
  2009年   26593篇
  2008年   45081篇
  2007年   48225篇
  2006年   47202篇
  2005年   46566篇
  2004年   44562篇
  2003年   42221篇
  2002年   39415篇
  2001年   59309篇
  2000年   60283篇
  1999年   50745篇
  1998年   13538篇
  1997年   12181篇
  1996年   12586篇
  1995年   12652篇
  1994年   11833篇
  1992年   40053篇
  1991年   39512篇
  1990年   38110篇
  1989年   36956篇
  1988年   34207篇
  1987年   33465篇
  1986年   31861篇
  1985年   30093篇
  1984年   22867篇
  1983年   19879篇
  1982年   11760篇
  1979年   21597篇
  1978年   15823篇
  1977年   13105篇
  1976年   12105篇
  1975年   13216篇
  1974年   15979篇
  1973年   15747篇
  1972年   14859篇
  1971年   13874篇
  1970年   13138篇
  1969年   12410篇
  1968年   11564篇
排序方式: 共有10000条查询结果,搜索用时 46 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.
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   
4.
In 2019, the scientists who discovered how cells sense and adapt to oxygen availability were awarded the Nobel Prize. This elegant sensing pathway is conserved throughout evolution, and it underpins the physiology and pathology that we, as clinicians in anaesthesia and critical care, encounter on a daily basis. The purpose of this review is to bring hypoxia-inducible factor, and the oxygen-sensing pathway as a whole, to the wider clinical community. We describe how this unifying mechanism was discovered, and how it orchestrates diverse changes such as erythropoiesis, ventilatory acclimatisation, pulmonary vascular remodelling and altered metabolism. We explore the lessons learnt from genetic disorders of oxygen sensing, and the wider implications in evolution of all animal species, including our own. Finally, we explain how this pathway is relevant to our clinical practice, and how it is being manipulated in new treatments for conditions such as cancer, anaemia and pulmonary hypertension.  相似文献   
5.
Journal of Neuro-Oncology - Adjuvant radiation is often used in patients with low grade gliomas with high-risk characteristics with a recommended dose of 45–54 Gy. We used the...  相似文献   
6.
7.
8.
Fu  Xiaoxue  Richards  John E. 《Brain topography》2022,35(4):398-415
Brain Topography - Accurate cortical source localization of event-related potentials (ERPs) requires using realistic head models constructed from the participant’s structural magnetic...  相似文献   
9.
Odontology - The purpose of this study was to investigate whether the root perforation repair with mineral aggregate-based cements affects the retention of customized fiberglass posts to bovine...  相似文献   
10.
Postbariatric loss of muscle tissue could negatively affect long-term health due to its role in various bodily processes, such as metabolism and functional capacity. This meta-analysis aimed to unravel time-dependent changes in the magnitude and progress of lean body mass (LBM), fat-free mass (FFM), and skeletal muscle mass (SMM) loss following bariatric surgery. A systematic literature search was conducted in Pubmed, Embase, and Web of Science. Fifty-nine studies assessed LBM (n = 37), FFM (n = 20), or SMM (n = 3) preoperatively and ≥1 time points postsurgery. Random-effects meta-analyses were performed to determine pooled loss per outcome parameter and follow-up time point. At 12-month postsurgery, pooled LBM loss was ?8.13 kg [95%CI ?9.01; ?7.26]. FFM loss and SMM loss were ?8.23 kg [95%CI ?10.74; ?5.73] and ?3.18 kg [95%CI ?5.64; ?0.71], respectively. About 55% of 12-month LBM loss occurred within 3-month postsurgery, followed by a more gradual decrease up to 12 months. Similar patterns were seen for FFM and SMM. In conclusion, >8 kg of LBM and FFM loss was observed within 1-year postsurgery. LBM, FFM, and SMM were predominantly lost within 3-month postsurgery, highlighting that interventions to mitigate such losses should be implemented perioperatively.  相似文献   
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