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   918850篇
  免费   57775篇
  国内免费   1853篇
耳鼻咽喉   12007篇
儿科学   29614篇
妇产科学   23001篇
基础医学   140721篇
口腔科学   26911篇
临床医学   77281篇
内科学   181864篇
皮肤病学   22684篇
神经病学   66847篇
特种医学   31050篇
外国民族医学   106篇
外科学   130041篇
综合类   15962篇
现状与发展   2篇
一般理论   198篇
预防医学   74621篇
眼科学   21289篇
药学   69710篇
  3篇
中国医学   3140篇
肿瘤学   51426篇
  2021年   9513篇
  2019年   9558篇
  2018年   13809篇
  2017年   9905篇
  2016年   10713篇
  2015年   11816篇
  2014年   15710篇
  2013年   23392篇
  2012年   33175篇
  2011年   34707篇
  2010年   19755篇
  2009年   17740篇
  2008年   30908篇
  2007年   33032篇
  2006年   33073篇
  2005年   31343篇
  2004年   30058篇
  2003年   28325篇
  2002年   27496篇
  2001年   42528篇
  2000年   43562篇
  1999年   35768篇
  1998年   9288篇
  1997年   7659篇
  1996年   7901篇
  1995年   7439篇
  1994年   6774篇
  1992年   25848篇
  1991年   25634篇
  1990年   24916篇
  1989年   24361篇
  1988年   22166篇
  1987年   21397篇
  1986年   20480篇
  1985年   19162篇
  1984年   14073篇
  1983年   11941篇
  1982年   6638篇
  1979年   13012篇
  1978年   9123篇
  1977年   7780篇
  1976年   7477篇
  1975年   8353篇
  1974年   9859篇
  1973年   9534篇
  1972年   8963篇
  1971年   8391篇
  1970年   8077篇
  1969年   7558篇
  1968年   7030篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
A case of generalized eruptive histiocytoma (GEH) was evaluated and examined histopathologically and ultrastructurally. A 24-year-old male had an episode of high fever and drug-induced eruption prior to the appearance of multiple skin lesions. Uniform, red to dark-red papular lesions appeared on his cheeks and then became generalized. The lesions were composed of a massive dermal infiltrate of histiocytes, which had oval nuclei and amphophilic cytoplasm. The cytoplasm contained unique annular structures, myeloid bodies and vacuoles. The specificity of these structures is as yet unknown. Reactive stimulation rather than neoplastic proliferation may be a causative factor in GEH.  相似文献   
992.
993.
Bipolar disorder (manic depressive disease) affects 1% of the United States population. These persons suffer from prolonged episodes of extreme elation and depression. There is a significant incidence of dental pathosis and a need for dental care among these patients. The medications used for the treatment of this disease, their physiologic effects, and their interactions with the drugs used in dentistry are reviewed.  相似文献   
994.
The activity of enterokinase and some dipeptidases (glycylalanine, glycylleucine, glycylvaline and glycylglycine) was studied in the intestinal mucosa biopsy specimens of 52 patients with chronic enteritis. Hydroxyproline excretion in the urine was defined before and after gelatin tolerance testing which showed a decrease in hydrolysis and protein absorption in the small intestine in chronic enteritis. A decrease in the level of dipeptidases and enterokinase involved in membranous digestion was noted whereas the level of glycylglycine acting intracellularly was practically unchanged. A decrease in the enzymatic activity correlated with a degree of gravity of disease and a degree of change in a morphological picture of the intestinal mucosa.  相似文献   
995.
During the intervening years since metoprolol was first reviewed in the Journal (1977), it has become widely used in the treatment of mild to moderate hypertension and angina pectoris. Although much data have accumulated, its precise mechanisms of action in these diseases remain largely uncertain. Optimum treatment of hypertension and angina pectoris with metoprolol is achieved through dose titration within the therapeutic range. It has been clearly demonstrated that metoprolol is at least as effective as other beta-blockers, diuretics and certain calcium antagonists in the majority of patients. Although a twice daily dosage regimen is normally used, satisfactory control can be maintained in many patients with single daily doses of conventional or, more frequently, slow release formulations. Addition of a diuretic may improve the overall response rate in hypertension. Several controlled trials have studied the effects of metoprolol administered during the acute phase and after myocardial infarction. In early intervention trials a reduction in total mortality was achieved in one moderately large trial of prolonged treatment, but in another, which excluded patients already being treated with beta-blockers or certain calcium antagonists and where treatment was only short term, mortality was significantly reduced only in 'high risk' patients. Overall results with metoprolol have not demonstrated that early intervention treatment in all patients produces clinically important improvement in short term mortality. Thus, the use of metoprolol during the early stages of myocardial infarction is controversial, largely because of the requirement to treat all patients to save a small number at 'high risk'. This blanket coverage approach to treatment may be more justified during the post-infarction follow-up phase since it has been shown that metoprolol slightly, but significantly, reduces the mortality rate for periods of up to 3 years. Metoprolol is generally well tolerated and its beta 1-selectivity may facilitate its administration to certain patients (e.g. asthmatics and diabetics) in whom non-selective beta-blockers are contraindicated. Temporary fatigue, dizziness and headache are among the most frequently reported side effects. After a decade of use, metoprolol is well established as a first choice drug in mild to moderate hypertension and stable angina, and is beneficial in post-infarction patients. Further study is needed in less well established areas of treatment such as cardiac arrhythmias, idiopathic dilated cardiomyopathy and hypertensive cardiomegaly.  相似文献   
996.
Advances in the treatment of childhood cancer have produced dramatic changes in survival. Unfortunately, many of the advances associated with this improvement have been accompanied by delayed sequelae induced by treatments such as surgery, radiotherapy, and chemotherapy. This article reviews published reports of treatment sequelae and examines their impact on the design of current forms of treatment. Recognition of the delayed effects of these treatment modalities has resulted in alterations in established therapies. This alteration is an ongoing process and demonstrates the concern of physicians with improving quality of life for long-term survivors of childhood cancer.  相似文献   
997.
998.
The number of cases of Reye syndrome reported annually to the Centers for Disease Control declined markedly between 1980 and 1985. In this article, we present pharmaceutical marketing research data that suggest sharp decreases in the use and purchase of children's aspirin between 1980 and 1985. These trends appear to correspond to the decrease in reporting of Reye syndrome cases. Additionally, analysis of physician mentions of aspiring and acetaminophen for treating flu and chickenpox showed statistically significant trends toward decreasing recommendations for the use of aspirin and significant trends toward increasing recommendations for use of acetaminophen. Trends in wholesale purchases of aspirin and acetaminophen by drug stores from 1979 through 1985 demonstrated a significant decline for the 81-mg children's aspirin tablet and an increase in purchases of children's acetaminophen products. Many factors may influence physician and parents' choice of analgesic/antipyretic medication, including information about Reye syndrome. Data suggest that a continuing decline in the use of aspirin for children may be accompanied by a continuing decline in the reported number of Reye syndrome cases.  相似文献   
999.
1000.
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