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   5799766篇
  免费   435689篇
  国内免费   16427篇
耳鼻咽喉   83887篇
儿科学   188705篇
妇产科学   157962篇
基础医学   850012篇
口腔科学   164896篇
临床医学   536766篇
内科学   1056908篇
皮肤病学   135530篇
神经病学   474734篇
特种医学   225272篇
外国民族医学   1433篇
外科学   870994篇
综合类   159002篇
现状与发展   24篇
一般理论   3146篇
预防医学   482195篇
眼科学   141172篇
药学   417794篇
  26篇
中国医学   14751篇
肿瘤学   286673篇
  2021年   57955篇
  2019年   60126篇
  2018年   79030篇
  2017年   60319篇
  2016年   67236篇
  2015年   78692篇
  2014年   113455篇
  2013年   179567篇
  2012年   168273篇
  2011年   181620篇
  2010年   140101篇
  2009年   136735篇
  2008年   166307篇
  2007年   180373篇
  2006年   186235篇
  2005年   180274篇
  2004年   179999篇
  2003年   169162篇
  2002年   157974篇
  2001年   231314篇
  2000年   229726篇
  1999年   203239篇
  1998年   80424篇
  1997年   73436篇
  1996年   71539篇
  1995年   66793篇
  1994年   60785篇
  1993年   56119篇
  1992年   152591篇
  1991年   147894篇
  1990年   143730篇
  1989年   140005篇
  1988年   129577篇
  1987年   127150篇
  1986年   120574篇
  1985年   117224篇
  1984年   92464篇
  1983年   81157篇
  1982年   56676篇
  1981年   52162篇
  1979年   84106篇
  1978年   63680篇
  1977年   55478篇
  1976年   51939篇
  1975年   54735篇
  1974年   62558篇
  1973年   60140篇
  1972年   56791篇
  1971年   53016篇
  1970年   49494篇
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
901.
902.
903.
In December 2019, a new type of coronavirus was detected for the first time in Wuhan, Hubei Province, China. According to the reported data, the emerging coronavirus has spread worldwide, infecting more than fifty-seven million individuals, leading to more than one million deaths. The current study aimed to review and discuss the hematological findings of COVID-19. Laboratory changes and hematologic abnormalities have been reported repeatedly in COVID-19 patients. WBC count and peripheral blood lymphocytes are normal or slightly reduced while these indicators may change with the progression of the disease. In addition, several studies demonstrated that decreased hemoglobin levels in COVID-19 patients were associated with the severity of the disease. Moreover, thrombocytopenia, which is reported in 5%-40% of patients, is known to be associated with poor prognosis of the disease. COVID-19 can present with various hematologic manifestations. In this regard, accurate evaluation of laboratory indicators at the beginning and during COVID-19 can help physicians to adjust appropriate treatment and provide special and prompt care for those in need.  相似文献   
904.
905.
906.
907.
The special interest group on sensitive skin of the International Forum for the Study of Itch previously defined sensitive skin as a syndrome defined by the occurrence of unpleasant sensations (stinging, burning, pain, pruritus and tingling sensations) in response to stimuli that normally should not provoke such sensations. This additional paper focuses on the pathophysiology and the management of sensitive skin. Sensitive skin is not an immunological disorder but is related to alterations of the skin nervous system. Skin barrier abnormalities are frequently associated, but there is no cause and direct relationship. Further studies are needed to better understand the pathophysiology of sensitive skin – as well as the inducing factors. Avoidance of possible triggering factors and the use of well-tolerated cosmetics, especially those containing inhibitors of unpleasant sensations, might be suggested for patients with sensitive skin. The role of psychosocial factors, such as stress or negative expectations, might be relevant for subgroups of patients. To date, there is no clinical trial supporting the use of topical or systemic drugs in sensitive skin. The published data are not sufficient to reach a consensus on sensitive skin management. In general, patients with sensitive skin require a personalized approach, taking into account various biomedical, neural and psychosocial factors affecting sensitive skin.  相似文献   
908.
909.
Osteogenesis imperfecta (OI) is a collagen-related bone disorder characterized by fragile osteopenic bone and muscle weakness. We have previously shown that the soluble activin receptor type IIB decoy (sActRIIB) molecule increases muscle mass and improves bone strength in the mild to moderate G610C mouse model of OI. The sActRIIB molecule binds multiple transforming growth factor-β (TGF-β) ligands, including myostatin and activin A. Here, we investigate the musculoskeletal effects of inhibiting activin A alone, myostatin alone, or both myostatin and activin A in wild-type (Wt) and heterozygous G610C (+/G610C) mice using specific monoclonal antibodies. Male and female Wt and +/G610C mice were treated twice weekly with intraperitoneal injections of monoclonal control antibody (Ctrl-Ab, Regn1945), anti-activin A antibody (ActA-Ab, Regn2476), anti-myostatin antibody (Mstn-Ab, Regn647), or both ActA-Ab and Mstn-Ab (Combo, Regn2476, and Regn647) from 5 to 16 weeks of age. Prior to euthanasia, whole body composition, metabolism and muscle force generation assessments were performed. Post euthanasia, hindlimb muscles were evaluated for mass, and femurs were evaluated for changes in microarchitecture and biomechanical strength using micro–computed tomography (μCT) and three-point bend analyses. ActA-Ab treatment minimally impacted the +/G610C musculoskeleton, and was detrimental to bone strength in male +/G610C mice. Mstn-Ab treatment, as previously reported, resulted in substantial increases in hindlimb muscle weights and overall body weights in Wt and male +/G610C mice, but had minimal skeletal impact in +/G610C mice. Conversely, the Combo treatment outperformed ActA-Ab alone or Mstn-Ab alone, consistently increasing hindlimb muscle and body weights regardless of sex or genotype and improving bone microarchitecture and strength in both male and female +/G610C and Wt mice. Combinatorial inhibition of activin A and myostatin more potently increased muscle mass and bone microarchitecture and strength than either antibody alone, recapturing most of the observed benefits of sActRIIB treatment in +/G610C mice. © 2022 American Society for Bone and Mineral Research (ASBMR).  相似文献   
910.
Treatment decisions in patients with metastatic bone disease rely on accurate survival estimation. We developed the original PATHFx models using expensive, proprietary software and now seek to provide a more cost-effective solution. Using open-source machine learning software to create PATHFx version 2.0, we asked whether PATHFx 2.0 could be created using open-source methods and externally validated in two unique patient populations. The training set of a well-characterized, database records of 189 patients and the bnlearn package within R Version 3.5.1 (R Foundation for Statistical Computing), was used to establish a series of Bayesian belief network models designed to predict survival at 1, 3, 6, 12, 18, and 24 months. Each was externally validated in both a Scandinavian (n = 815 patients) and a Japanese (n = 261 patients) data set. Brier scores and receiver operating characteristic curves to assessed discriminatory ability. Decision curve analysis (DCA) evaluated whether models should be used clinically. DCA showed that the model should be used clinically at all time points in the Scandinavian data set. For the 1-month time point, DCA of the Japanese data set suggested to expect better outcomes assuming all patients will survive greater than 1 month. Brier scores for each curve demonstrate that the models are accurate at each time point. Statement of Clinical Significance: we successfully transitioned to PATHFx 2.0 using open-source software and externally validated it in two unique patient populations, which can be used as a cost-effective option to guide surgical decisions in patients with metastatic bone disease.  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