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   68454篇
  免费   2508篇
  国内免费   512篇
耳鼻咽喉   411篇
儿科学   810篇
妇产科学   658篇
基础医学   7358篇
口腔科学   3556篇
临床医学   5059篇
内科学   12601篇
皮肤病学   1403篇
神经病学   5347篇
特种医学   1894篇
外国民族医学   2篇
外科学   12420篇
综合类   3597篇
现状与发展   1篇
一般理论   6篇
预防医学   6293篇
眼科学   1195篇
药学   4245篇
  24篇
中国医学   2448篇
肿瘤学   2146篇
  2023年   593篇
  2022年   865篇
  2021年   2059篇
  2020年   1395篇
  2019年   5235篇
  2018年   5434篇
  2017年   3482篇
  2016年   1062篇
  2015年   1031篇
  2014年   1930篇
  2013年   2060篇
  2012年   1501篇
  2011年   1791篇
  2010年   1526篇
  2009年   1279篇
  2008年   1278篇
  2007年   1278篇
  2006年   1095篇
  2005年   898篇
  2004年   716篇
  2003年   709篇
  2002年   496篇
  2001年   557篇
  2000年   451篇
  1999年   421篇
  1998年   277篇
  1997年   268篇
  1996年   231篇
  1995年   222篇
  1994年   195篇
  1993年   157篇
  1992年   150篇
  1991年   137篇
  1990年   93篇
  1989年   93篇
  1987年   96篇
  1986年   88篇
  1985年   2835篇
  1984年   3382篇
  1983年   2860篇
  1982年   3328篇
  1981年   3020篇
  1980年   2513篇
  1979年   2500篇
  1978年   2062篇
  1977年   1535篇
  1976年   1995篇
  1975年   1513篇
  1974年   1325篇
  1973年   1272篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
Introduction: Effective treatment of rheumatoid arthritis (RA) requires suppression of the underlying inflammation. Measurement of such inflammation, the disease activity, is mandatory to target treatment and maximize outcomes. However, this is not as straightforward as it may seem.

Areas covered: The many tools developed to measure disease activity in RA, from composite scores and patient-reported outcomes, to laboratory markers and imaging are discussed, with a focus on their utility in guiding therapy and assessing response. The complex issues in measuring disease activity in RA, whether in clinical trials or normal clinical practice, and in the context of national guidelines and recommendations, available time, and resources are considered.

Expert commentary: The key to effective management of RA is the rapid suppression of inflammation, ideally to remission, with maintenance of such remission. The aim is to prevent disability and maximize quality of life. Central to this is the ability to determine disease activity (potentially open to suppression) as opposed to damage (irreversible). A variety of measures are currently available, allowing better assessment of response to treatment. In the future, the development of predictive biomarkers allowing targeting of drugs may revolutionize this field and render the tools of today redundant.  相似文献   

23.
24.
《Drug discovery today》2022,27(6):1733-1742
Compounds that exhibit assay interference or undesirable mechanisms of bioactivity are routinely encountered in assays at various stages of drug discovery. We observed that assays for the investigation of thiol-reactive and redox-active compounds have not been collected in a comprehensive review. Here, we review these assays and subject them to experimental optimization to improve their reliability. We demonstrate the usefulness of our assay cascade by assaying a library of bioactive compounds, chemical probes, and a set of approved drugs. These high-throughput assays should complement the array of wet-lab and in silico assays during the initial stages of hit discovery campaigns to pursue only hit compounds with tractable mechanisms of action.  相似文献   
25.
This study evaluated the genetic variation of 17 autosomal short tandem repeat (STR) loci included in the PowerPlex® 18D Kit. Samples of 562 unrelated healthy Lahu individuals living in Yunnan Province in southwestern China were investigated. The data were analyzed to provide information on allele frequencies and other statistical parameters relevant to the forensic population. Of the 17 loci, 16 reached the Hardy–Weinberg equilibrium after Bonferroni correction. A total of 176 alleles were identified in 17 STR loci, and allele frequencies ranged from 0.000 890 to 0.578 292. The combined discrimination power (CPD) and probability of excluding paternity (CPE) of the 17 STR loci were 0.999 999 999 999 999 999 489 and 0.999 998 301 753 122. The genetic relationships among 28 populations were also estimated.  相似文献   
26.
IntroductionThe immunosuppressant agents in kidney transplantation (KT) may lead to various complications such as opportunistic infections and malignancies. BK virus associated nephropathy is a significant complication following KT, and it can result in graft failure. BK virus causes tubulointerstitial nephritis, ureter stenosis, and even graft failure in KT recipients with impaired immune system. We described a 63-year-old woman, who was a hepatitis C carrier and on dialysis for 22 years before KT, who received cadaveric-donor KT 2 years previously. She reported decreasing urine output and general weakness. The serum creatinine level was slightly increased from 2.94 to 4.38 mg/dL.MethodsImmunosuppressant medications including prednisolone, everolimus, cyclosporin, and mycophenolate sodium were continued as maintenance therapy post KT. Kidney biopsy was performed due to deterioration of graft function.ResultsThe kidney biopsy showed consistent results with early-stage polyomavirus nephropathy, characterized by focal viral cytopathic changes with positive immunohistochemical signals and mesangial proliferative glomerulonephritis, immune-complex-mediated (Fig 1 and Fig 2). Negative C4d staining at peritubular capillary was reported. The dosage of mycophenolate sodium was tapered from 720 to 360 mg daily and that of everolimus increased from 0.5 to 1.0 mg daily due to BK viral infection with BK nephropathy. The serum creatinine level was 2.75 mg/dL after treatment.ConclusionEarly detection of BK nephropathy and decreasing immunosuppressant agents are the mainstay of treatment. Substituting leflunomide for mycophenolate sodium and increasing dosage of everolimus has been proposed to solve BK nephropathy. We presented that the use of leflunomide in such situation is in a timely manner.  相似文献   
27.
28.
<正>机体的血钾参与并维持细胞代谢,保持细胞内液渗透压及酸碱平衡,并可维持神经肌肉组织兴奋及心肌功能~([1-2])。中重度低血钾主要表现为肌无力,可延及机体的躯干和呼吸肌,造成呼吸困难,还可引发腱反射减弱或消失、肠麻痹及心脏传导阻滞、节律异  相似文献   
29.
30.
《Injury》2019,50(5):1105-1110
IntroductionGetting the right patient, to the right place, at the right time is dependent on a multitude of modifiable and non-modifiable factors. One potentially modifiable factor is the number and location of trauma centres (TC). Overabundance of TC dilutes volumes and could be associated with worse outcomes. We describe a methodology that evaluates trauma system reconfiguration without reductions in potential access to care. We used the mature trauma system of New South Wales (NSW) as a model given the perceived overabundance of urban major trauma centres (MTC).MethodsWe first evaluated potential access to TC care via ground and air transport through the use of geographic information systems (GIS) network analysis. Potential access was defined as the proportion of the population living within 60-min transport time from a potential scene of injury to a TC by ground or rotary-wing aircraft. Sensitivity analyses were carried out in order to account for potential pre-hospital interventions and/or transport delays; travel times of 15-, 30-, 45-, 60-, and 90-min were also analyzed. We then evaluated if the current configuration of the system (number of urban MTS in the Sydney basin) could be optimized without reductions in potential access to care using two GIS methodologies: location-allocation and individual removal of MTC.Results86% of the NSW population has potential access to a TC within 60 min ground travel time; potential access improves to 99% with rotary-wing transport. The 1% of the population without potential TC access lives in 48% of the land area (>384,000km2). Utilizing two different methodologies we identified that there was no change in potential access by ground transport after removing 1 or 2 MTC in the Sydney basin at the 30-, 45-, and 60-min transport times. However, 0.02% and 0.5% of the population would not have potential access to MTC care at 15 min after removing one and two MTC respectively.DiscussionRedistribution of the number of MTC in the Sydney basin could be achieved without a significant impact on potential access to care. Our approach can be utilized as an initial tool to evaluate a trauma system where overabundance of coverage is present.  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