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   43735篇
  免费   7080篇
  国内免费   209篇
耳鼻咽喉   924篇
儿科学   1217篇
妇产科学   1356篇
基础医学   3924篇
口腔科学   2960篇
临床医学   6260篇
内科学   9371篇
皮肤病学   1041篇
神经病学   4064篇
特种医学   2154篇
外国民族医学   8篇
外科学   6970篇
综合类   226篇
现状与发展   12篇
一般理论   11篇
预防医学   4194篇
眼科学   856篇
药学   1737篇
中国医学   64篇
肿瘤学   3675篇
  2023年   1183篇
  2022年   520篇
  2021年   950篇
  2020年   1434篇
  2019年   778篇
  2018年   1699篇
  2017年   1593篇
  2016年   1917篇
  2015年   1975篇
  2014年   2471篇
  2013年   2986篇
  2012年   1797篇
  2011年   1811篇
  2010年   1928篇
  2009年   2498篇
  2008年   1612篇
  2007年   1448篇
  2006年   1606篇
  2005年   1402篇
  2004年   1191篇
  2003年   1108篇
  2002年   1058篇
  2001年   1164篇
  2000年   976篇
  1999年   1036篇
  1998年   765篇
  1997年   701篇
  1996年   722篇
  1995年   573篇
  1994年   455篇
  1993年   425篇
  1992年   560篇
  1991年   524篇
  1990年   541篇
  1989年   508篇
  1988年   463篇
  1987年   505篇
  1986年   442篇
  1985年   427篇
  1984年   330篇
  1983年   295篇
  1982年   225篇
  1979年   283篇
  1978年   232篇
  1977年   220篇
  1975年   190篇
  1974年   209篇
  1973年   197篇
  1972年   226篇
  1971年   197篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
Identification of Alcohol Abuse and Alcoholism with Biological Parameters   总被引:3,自引:0,他引:3  
The prevalence and incidence of heavy alcohol consumption are major problems which have been increasing in many countries in recent years. It is crucial for physicians to consistently identify early drinking problems as well as the various end disease states in order to minimize suffering and maximize recovery. This paper reviews the evolutionary development of clinical tools for detection of alcohol abuse. The focus is primarily on clinical/biochemical indicators of alcohol abuse, emphasizing but not limited to changes in hematological characteristics, liver enzyme activity, lipids, immune function factors, hormones, neurological factors, and some physically based tests. Use of test combinations and sophisticated statistical analysis of pattern changes in test batteries evidence increased diagnostic efficiency.  相似文献   
93.
Using an experimental model of continuous endotoxin infusion, the effects of castration, testosterone and estrogen substitution on disseminated intravascular coagulation in male rats were investigated. Male rats which are not pretreated react in the same way to an endotoxin infusion as female animals, with an increase in free plasma hemoglobin, decrease of fibrinogen level, decrease of hematocrit and platelets and glomerular fibrin depositions. Different experimental groups of testectomized rats were pretreated with (i) 0.3 micrograms (pregnancy-conserving dose) or (ii) 30 micrograms ethinylestradiol (ovulation-suppression dose) or (iii) 250 mg testosterone. They were then compared to groups of animals treated with sesame oil as well as untreated group of rats. The pretreatment with testosterone and estrogens in the small-dose group had only an insignificant effect on the shock sequence. Only those animals which were treated with a high dose of estrogens showed a dramatic enhancement of their endotoxin sensitivity. It was also shown that in male animals an increased estrogen level might mediate a state of 'preparation', but testosterone does not 'prepare' castrated rats for the generalized Schwartzman reaction. The possible significance of enhancement of endotoxin toxicity by estrogens in explaining some pathophysiological characteristics of disseminated intravascular coagulation in pregnancy is discussed.  相似文献   
94.
95.
In the sick sinus syndrome, in sinu-atrial conduction defects or in atrial flutter or fibrillation a stress-adapted, frequency-adapted stimulation cannot be obtained by the processing of the atrial potential. Here one depends on partly extracardiac parameters which contain informations about the metabolic and stress situation, respectively. A survey of the parameters for a frequency-adapted stimulation discussed at present is given and a critical valuation of them is carried out. It is shown that all parameters up to now experimentally and clinically, respectively, tested are more or less problematic and that the way out of the difficulty most consist in deriving the controlled variable for a stress adapted stimulation rate from several parameters.  相似文献   
96.
BACKGROUND: Improved prognosis can be achieved in selected patients with peritoneal carcinomatosis (PC) by major surgery and hyperthermic intraperitoneal chemotherapy (HIPEC). METHOD: Sixty seven patients with PC were operated with the aim of complete macroscopical cytoreduction followed by HIPEC (using cisplatin, mitomycin or mitoxantrone). Quality of life was assessed with the EORTC QLQ-C30 questionnaire. RESULTS: The patients had a variety of primary tumours, including appendix carcinomas (22/67). Mean operating time was 7 hours and complete cytoreduction was achieved in 58% of the patients. Overall morbidity was 34%. Post-operative mortality was 4.5%. The mean score for global health status of long-term survivors (20 questionnaires/25 patients) was 62.6 (73.3 for the control population, p=0.07). Functional status, particularly the role (56.4) and the social functioning (53.9) were impaired. CONCLUSION: Cytoreductive surgery combined with HIPEC is associated with an increased morbidity and mortality. Complications are predominantly related to major surgery. Following this aggressive treatment, survivors may achieve a satisfactory quality of life.  相似文献   
97.
98.
This is a case report of a 13-year-old girl who developed clinical symptoms of primary pulmonary hypertension (PPH). The prognosis is determined by progressive overloading of the right heart. Tissue from both the right and the left atria was examined using immunohistochemical methods. Cardiodilatin/alpha-ANP (atrial natriuretic peptide)-producing myoendocrine cells were analysed. As recent investigations have shown, the atrium and especially the atrial appendages of the heart function as an endocrine organ which is stimulated by pressure and volume overload, and which produces a natriuretic and vasodilatory peptide hormone from myoendocrine cells. In our case we found a general hyperplasia of the myoendocrine cells of the right atrium which is interpreted as a secondary reaction towards an increasing overload. This also means a temporary compensation of the progressive obstruction of the small pulmonary arteries, initiated by vasodilatory heart peptides. These investigations are in agreement with those of other groups who found an increased production of cardiac hormones in atrial overload. In the perinuclear area, electron microscopy shows zones of autophagolysis and the typical specific atrial granules which account for a dysfunction of atrial myoendocrine cells, as seen in other cardiac diseases. Our results may contribute to a better understanding of the pathogenesis of PPH and may help in diagnosis and therapy.  相似文献   
99.
100.
The rate of glucose consumption in cultured epithelium, endothelium, and keratocytes was measured; and the effect of reduced glucose availability on the consumption rate of these three cell lines was delineated. All three cell types exhibited an asymptotic decrease of glucose over time while being incubated in Krebs-Ringers solutions of varying glucose concentrations. At a concentration resembling that of the aqueous, epithelium (EPI), endothelium (ENDO), and keratocytes (K) consumed 6.7, 7.4, and 9.0 micrograms/cm2/hr respectively. Each cell type consumed glucose at a rate that was related to the amount of available glucose. As glucose concentration was reduced from 90 to 30 mg%, which was a 66% reduction in available glucose, the consumption of EPI, ENDO, and K dropped 74%, 61%, and 44% respectively.  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