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   19307篇
  免费   1279篇
  国内免费   83篇
耳鼻咽喉   189篇
儿科学   516篇
妇产科学   389篇
基础医学   2240篇
口腔科学   329篇
临床医学   1570篇
内科学   4033篇
皮肤病学   245篇
神经病学   1086篇
特种医学   541篇
外国民族医学   1篇
外科学   3451篇
综合类   646篇
一般理论   18篇
预防医学   1457篇
眼科学   517篇
药学   1992篇
中国医学   222篇
肿瘤学   1227篇
  2023年   151篇
  2022年   428篇
  2021年   692篇
  2020年   441篇
  2019年   563篇
  2018年   661篇
  2017年   461篇
  2016年   379篇
  2015年   526篇
  2014年   722篇
  2013年   896篇
  2012年   1354篇
  2011年   1334篇
  2010年   775篇
  2009年   601篇
  2008年   1056篇
  2007年   1050篇
  2006年   982篇
  2005年   896篇
  2004年   823篇
  2003年   732篇
  2002年   604篇
  2001年   553篇
  2000年   493篇
  1999年   402篇
  1998年   151篇
  1997年   114篇
  1996年   115篇
  1995年   123篇
  1994年   63篇
  1993年   85篇
  1992年   210篇
  1991年   188篇
  1990年   166篇
  1989年   176篇
  1988年   138篇
  1987年   156篇
  1986年   127篇
  1985年   138篇
  1984年   118篇
  1983年   91篇
  1982年   63篇
  1981年   61篇
  1979年   98篇
  1978年   65篇
  1977年   68篇
  1975年   60篇
  1974年   52篇
  1973年   57篇
  1972年   51篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
1.
Anaplastic thyroid carcinoma (ATC) is an aggressive thyroid malignancy with high mortality rate. This malignancy arises in thyroid follicular cells either denovo or with an associated differentiated thyroid carcinoma component. Clinically, it usually presents as a rapidly enlarging mass, pain and locally compressive symptoms. Histopathologic variability and heterogeneity often pose diagnostic challenges, especially in scant and paucicellular specimens. This article describes the clinical, histopathologic and molecular features of ATC and also addresses the associated diagnostic limitations and challenges.  相似文献   
2.
BACKGROUND Approximately 20% of patients with neuroendocrine tumours(NETs) develop carcinoid syndrome(CS),characterised by flushing and diarrhoea.Somatostatin analogues or telotristat can be used to control symptoms of CS through inhibition of serotonin secretion.Although CS is often the cause of diarrhoea among patients with gastroenteropancreatic NETs(GEP-NETs),other causes to consider include pancreatic enzyme insufficiency(PEI),bile acid malabsorption and small intestinal bacterial overgrowth.If other causes of diarrhoea unrelated to serotonin secretion are mistaken for CS diarrhoea,these treatments may be ineffective against the diarrhoea,risking detrimental effects to patient quality of life.AIM To identify and synthesise qualitative and quantitative evidence relating to the differential diagnosis of diarrhoea in patients with GEP-NETs.METHODS Electronic databases(MEDLINE,Embase and the Cochrane Library) were searched from inception to September 12,2018 using terms for NETs and diarrhoea.Congresses,systematic literature review bibliographies and included articles were also hand-searched.Any study designs and publication types were eligible for inclusion if relevant data on a cause(s) of diarrhoea in patients with GEP-NETs were reported.Studies were screened by two independent reviewers at abstract and full-text stages.Framework synthesis was adapted to synthesise quantitative and qualitative data.The definition of qualitative data was expanded to include all textual data in any section of relevant publications.RESULTS Forty-seven publications(44 studies) were included,comprising a variety of publication types,including observational studies,reviews,guidelines,case reports,interventional studies,and opinion pieces.Most reported on PEI on/after treatment with somatostatin analogs;9.5%-84% of patients with GEP-NETs had experienced steatorrhoea or confirmed PEI.Where reported,14.3%–50.7% of patients received pancreatic enzyme replacement therapy.Other causes of diarrhoea reported in patients with GEP-NETs included bile acid malabsorption(80%),small intestinal bacterial overgrowth(23.6%-62%),colitis(20%) and infection(7.1%).Diagnostic approaches included faecal elastase,breath tests,tauroselcholic(selenium-75) acid(Se HCAT) scan and stool culture,although evidence on the effectiveness or diagnostic accuracy of these approaches was limited.Assessment of patient history or diarrhoea characteristics was also reported as initial approaches for investigation.From the identified evidence,if diarrhoea is assumed to be CS diarrhoea,consequences include uncontrolled diarrhoea,malnutrition,and perceived ineffectiveness of CS treatment.Approaches for facilitating differential diagnosis of diarrhoea include improving patient and clinician awareness of non-CS causes and involvement of a multidisciplinary clinical team,including gastroenterologists.CONCLUSION Diarrhoea in GEP-NETs can be multifactorial with misdiagnosis leading to delayed patient recovery and inefficient resource use.This systematic literature review highlights gaps for further research on prevalence of non-CS diarrhoea and suitability of diagnostic approaches,to determine an effective algorithm for differential diagnosis of GEP-NET diarrhoea.  相似文献   
3.
4.
Dosage form is a mean used for the delivery of drug to a living body. In order to get the desired effect the drug should be delivered to its site of action at such rate and concentration to achieve the maximum therapeutic effect and minimum adverse effect. Since oral route is still widely accepted route but having a common drawback of difficulty in swallowing of tablets and capsules. Therefore a lot of research has been done on novel drug delivery systems. This review is about oral dispersible tablets a novel approach in drug delivery systems that are now a day''s more focused in formulation world, and laid a new path that, helped the patients to build their compliance level with the therapy, also reduced the cost and ease the administration especially in case of pediatrics and geriatrics. Quick absorption, rapid onset of action and reduction in drug loss properties are the basic advantages of this dosage form.  相似文献   
5.
6.
7.
8.
The antigenic heterogeneity of Orientia in India is still unknown in many disease endemic areas. The present study aims to characterize the strains of O. tsutsugamushi circulating in Nagaland, Northeast India. Two patients clinically diagnosed with ST and hospitalized in Mon district hospital, Nagaland were identified from whom eschar tissues were collected. Both patients demonstrated antibodies against O. tsutsugamushi along with positive PCR amplification for 56 ?kDa gene. The prototype strain TA763 shared 90.4% homology with the sequences. Both the sequences formed a distinctive cluster demonstrating 100% similarity with strains identified from Thailand, Vietnam, China and southern parts of India.  相似文献   
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