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   3508篇
  免费   195篇
  国内免费   77篇
耳鼻咽喉   8篇
儿科学   338篇
妇产科学   104篇
基础医学   550篇
口腔科学   8篇
临床医学   233篇
内科学   495篇
皮肤病学   28篇
神经病学   452篇
特种医学   139篇
外科学   447篇
综合类   433篇
预防医学   51篇
眼科学   5篇
药学   287篇
  1篇
中国医学   53篇
肿瘤学   148篇
  2023年   32篇
  2022年   70篇
  2021年   91篇
  2020年   111篇
  2019年   91篇
  2018年   88篇
  2017年   84篇
  2016年   86篇
  2015年   86篇
  2014年   153篇
  2013年   190篇
  2012年   134篇
  2011年   189篇
  2010年   151篇
  2009年   148篇
  2008年   147篇
  2007年   158篇
  2006年   158篇
  2005年   121篇
  2004年   126篇
  2003年   102篇
  2002年   102篇
  2001年   114篇
  2000年   67篇
  1999年   93篇
  1998年   66篇
  1997年   60篇
  1996年   48篇
  1995年   48篇
  1994年   54篇
  1993年   46篇
  1992年   50篇
  1991年   40篇
  1990年   46篇
  1989年   44篇
  1988年   44篇
  1987年   36篇
  1986年   30篇
  1985年   48篇
  1984年   35篇
  1983年   21篇
  1982年   32篇
  1981年   26篇
  1980年   29篇
  1979年   13篇
  1978年   15篇
  1977年   13篇
  1976年   12篇
  1974年   9篇
  1973年   6篇
排序方式: 共有3780条查询结果,搜索用时 0 毫秒
71.
Agouti related protein (AgRP) is a recently discovered melanocortin receptors (MCR) antagonist implicated in the control of feeding behaviour. Expression of AgRP has been shown to be localized by in situ hybridization to the arcuate nucleus and median eminence of the brain, where it acts as an antagonist to the MC3 and MC4 receptors, while in the periphery the only significant expression was located in the adrenal medulla. As AgRP is only a weak antagonist of the MC2 and MC5 receptors, which are expressed principally by adipocytes and in the adrenal cortex, the question arizes as to the function of peripheral AgRP. In this study, we investigated the expression of AgRP in the rat adrenal and suggest that it is expressed in the adrenal cortex and not as previously described in the medulla. We also show that AgRP mRNA expression is upregulated in the adrenal during fasting and in the contralateral gland following unilateral adrenalectomy but not during chronic stress. These results indicate an as yet undefined role for AgRP in the periphery and are supportive of the suggestion that a further melanocortin receptor exists.  相似文献   
72.
The clinical manifestations of chronic disseminated histoplasmosis are non-specific and resemble those of other chronic infections and malignancies. We report the radiographic, sonographic and contrast-enhanced CT appearances of histoplasmosis in an adult male with non-insulin dependent diabetes mellitus, who was HIV negative and presented with weight loss and pyrexia. Imaging studies simulated tuberculosis with mediastinal lymphadenopathy, bilateral fibrotic lung lesions, hepatomegaly and bilateral hypoattenuating adrenal enlargement, without clinical or laboratory evidence of hypoadrenalism. Computed tomography-guided fine-needle aspiration biopsy of adrenal glands revealed Histoplasma capsulatum. We report our experience to increase awareness of the imaging spectrum of disseminated histoplasmosis and its similarity to tuberculosis as, with increasing incidence of AIDS, the chances of these infections are likely to increase. Moreover, awareness of this entity is important because it is known that untreated disseminated histoplasmosis is fatal.  相似文献   
73.
74.
Autoimmune Addison’s disease (AAD) is a complex genetic disease that results from the interaction of a predisposing genetic background with as yet unknown environmental factors. The disease is marked by the appearance of circulating autoantibodies against steroid 21-hydroxylase. Mutations of the autoimmune regulator gene are responsible for the so-called autoimmune polyendocrine syndrome type I (APS I), of which AAD is a major disease component. Among genetic factors for isolated AAD and APS II, a major role is played by HLA class II genes: HLA-DRB1*0301-DQA1*0501-DQB1*0201 and DRB1*04-DQA1*0301-DQB1*0302 are positively, and RB1*0403 is negatively, associated with a genetic risk for AAD. The MHC class I chain-related gene A allele 5.1 is strongly and positively associated with AAD. Other gene polymorphisms contributing to genetic risk for AAD are MHC2TA, the gene coding for class II transactivator, the master regulator of class II expression, cytotoxic T lymphocyte antigen-4, PTPN22 and the vitamin D receptor.  相似文献   
75.
BackgroundDopamine-secreting pheochromocytomas are exceedingly rare.Case presentationA 28-year-old woman, who was admitted due to 4 hours of acute-onset abdominal pain, detected an adrenal mass incidentally. She was almost asymptomatic without a known family history. Laboratory assessments showed significant increases in dopamine levels of serum and 24-h urinary. By using preoperative a-adrenergic receptor blockers, she developed orthostatic hypotension and palpitations. When she underwent laparoscopic left adrenalectomy, she experienced rapid cyclic fluctuations in systolic blood pressure from 90 mmHg to 200 mmHg. Postoperatively, she exhibited prolonged hypotension, requiring vasopressor therapy and fluid replacement. According to histopathological diagnosis, it was a pheochromocytoma. Dopamine levels in 24-h urine and serum decreased to normal after operation. Analysis of specific gene SDHB, SDHD, RET, VHL and NF1 detected no pathogenic mutations.ConclusionPatients with dopamine-secreting pheochromocytomas are mostly asymptomatic, leading to a significant delay in diagnosis. There is a large possibility for dopamine-secreting pheochromocytomas to show a malignant tendency than the adrenergic and noradrenergic phenotypes. The a-adrenergic receptor blocker is not indicated for preoperative medical treatment because it can cause hypotension and cardiovascular failure. Calcium channel blockers or metyrosine may be better alternatives. All patients with pheochromocytomas should receive targeted genetic testing based on specific clinical features. SDHB, SDHD, RET, VHL and NF1 mutations are suggested for genetic testing of adrenal dopamine-secreting pheochromocytomas.  相似文献   
76.
77.
78.
79.
《Annales d'endocrinologie》2018,79(3):153-156
Treatment of Cushing's disease remains a challenge. Whereas pituitary surgery can “cure” the patient and restore a completely normal pituitary adrenal axis, there are immediate failures and late recurrences which ultimately require alternate therapeutic approaches. These are numerous, but so are their drawbacks, and all appear to be “default options”. For the future, pituitary adenoma has to remain the “reasonable obsession” of efficient and optimistic therapists…  相似文献   
80.
DSD (Disorders or Differences in Sex Development) and Intersex are terms used to describe a diverse group of congenital conditions where the development of the reproductive system is different from what is usually expected. These conditions usually present at birth or adolescence and the health implications are wide ranging and often life-long. Given the complexity of many of the conditions, health care input when required should be provided by a multidisciplinary team who have appropriate expertise. Holistic care should include the consideration of the risk of cancer, prevention of osteoporosis, advice on hormones, sexual health and fertility options, and ongoing support in order to optimise quality of life and wellbeing. There is little evidence on the health of this group of individuals beyond middle age. Research in this field is essential to guide clinicians in providing high-quality care but also to allow affected individuals to make informed decisions about their own health care. This review will focus on the gynaecological aspects of multidisciplinary management.  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