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   1409276篇
  免费   115854篇
  国内免费   3334篇
耳鼻咽喉   18382篇
儿科学   46595篇
妇产科学   41069篇
基础医学   200954篇
口腔科学   37721篇
临床医学   126085篇
内科学   284416篇
皮肤病学   33371篇
神经病学   116981篇
特种医学   53923篇
外国民族医学   464篇
外科学   210695篇
综合类   32762篇
现状与发展   3篇
一般理论   488篇
预防医学   109961篇
眼科学   31552篇
药学   98593篇
  1篇
中国医学   3348篇
肿瘤学   81100篇
  2021年   10886篇
  2019年   11696篇
  2018年   16596篇
  2017年   12704篇
  2016年   14292篇
  2015年   16031篇
  2014年   22594篇
  2013年   33430篇
  2012年   45459篇
  2011年   47998篇
  2010年   28210篇
  2009年   27083篇
  2008年   44384篇
  2007年   46904篇
  2006年   47470篇
  2005年   45938篇
  2004年   43840篇
  2003年   41763篇
  2002年   40267篇
  2001年   73067篇
  2000年   74573篇
  1999年   61596篇
  1998年   17014篇
  1997年   15452篇
  1996年   15599篇
  1995年   14802篇
  1994年   13404篇
  1993年   12594篇
  1992年   45869篇
  1991年   43507篇
  1990年   41512篇
  1989年   39578篇
  1988年   36209篇
  1987年   35381篇
  1986年   32885篇
  1985年   31306篇
  1984年   23845篇
  1983年   20051篇
  1982年   12224篇
  1981年   10784篇
  1979年   20717篇
  1978年   14590篇
  1977年   12095篇
  1976年   11370篇
  1975年   11627篇
  1974年   14003篇
  1973年   13545篇
  1972年   12642篇
  1971年   11487篇
  1970年   10917篇
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
81.
82.
83.
Guidelines and consensus on the management of patients with acne aim to give evidence-based, expert-group recommendations. This review compares current guidelines and consensus articles to provide a compilation of recommendations on the treatment of acne with oral isotretinoin. Ten common, relevant, clinical questions are addressed, based on published recommendations, including the indications of isotretinoin, the proposed daily dose, the cumulative isotretinoin dose and the laboratory monitoring needed. Recommendations on special considerations are also addressed, including the timing of procedures and the question of an association of depression or inflammatory bowel disease with isotretinoin. A major limitation is the use of different classification systems for acne across guidelines. The recommended daily dose ranges from 0.3 to 0.5 mg/kg in the European guidelines to up to 1 mg/kg in the US guidelines. A specific duration of treatment of at least 6 months is only recommended in the European guidelines. All guidelines report the need of strict pregnancy prevention measures. The European, French and US guidelines recommend to monitor for symptoms of depression. Important clinical questions that are inconsistently addressed in guidelines include the age indication, the recommendation for a cumulative dose, the timing of procedures, the association of isotretinoin with IBD, the recommendation for preventing acne flares and for appropriate laboratory monitoring. These topics should be clearly included in the recommendations of guidelines as they are often raised in everyday clinical practice.  相似文献   
84.
85.
86.
87.
88.
89.
Mitochondria are known primarily as the location of the electron transport chain and energy production in cells. More recently, mitochondria have been shown to be signaling centers for apoptosis and inflammation. Reactive oxygen species (ROS) generated as by-products of the electron transport chain within mitochondria significantly impact cellular signaling pathways. Because of the toxic nature of ROS, mitochondria possess an antioxidant enzyme, superoxide dismutase 2 (SOD2), to neutralize ROS. If mitochondrial antioxidant enzymes are overwhelmed during severe infections, mitochondrial dysfunction can occur and lead to multiorgan failure or death. Pseudomonas aeruginosa is an opportunistic pathogen that can infect immunocompromised patients. Infochemicals and exotoxins associated with P. aeruginosa are capable of causing mitochondrial dysfunction. In this work, we describe the roles of SOD2 and mitochondrial ROS regulation in the zebrafish innate immune response to P. aeruginosa infection. sod2 is upregulated in mammalian macrophages and neutrophils in response to lipopolysaccharide in vitro, and sod2 knockdown in zebrafish results in an increased bacterial burden. Further investigation revealed that phagocyte numbers are compromised in Sod2-deficient zebrafish. Addition of the mitochondrion-targeted ROS-scavenging chemical MitoTEMPO rescues neutrophil numbers and reduces the bacterial burden in Sod2-deficient zebrafish. Our work highlights the importance of mitochondrial ROS regulation by SOD2 in the context of innate immunity and supports the use of mitochondrion-targeted ROS scavengers as potential adjuvant therapies during severe infections.  相似文献   
90.
Pancreatic ductal adenocarcinoma (PDAC) is predicted to become the second leading cause of cancer-related mortality within the next decade, with limited effective treatment options and a dismal long-term prognosis for patients. Genomic profiling has not yet manifested clinical benefits for diagnosis, treatment or prognosis in PDAC, due to the lack of available tissues for sequencing and the confounding effects of low tumour cellularity in many biopsy specimens. Increasing focus is now turning to the use of minimally invasive liquid biopsies to enhance the characterisation of actionable PDAC tumour genomes. Circulating tumour DNA (ctDNA) is the most comprehensively studied liquid biopsy analyte in blood and can provide insight into the molecular profile and biological characteristics of individual PDAC tumours, in real-time and in advance of traditional imaging modalities. This can pave the way for identification of new therapeutic targets, novel risk variants and markers of tumour response, to supplement diagnostic screening and provide enhanced scrutiny in treatment stratification. In the roadmap towards the application of precision medicine for clinical management in PDAC, ctDNA analyses may serve a leading role in streamlining candidate biomarkers for clinical integration. In this review, we highlight recent developments in the use of ctDNA-based liquid biopsies for PDAC and provide new insights into the technical, analytical and biological challenges that must be overcome for this potential to be realised.  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