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   898018篇
  免费   63523篇
  国内免费   2323篇
耳鼻咽喉   12474篇
儿科学   28666篇
妇产科学   26141篇
基础医学   126553篇
口腔科学   24680篇
临床医学   74699篇
内科学   182970篇
皮肤病学   18981篇
神经病学   71347篇
特种医学   36444篇
外国民族医学   336篇
外科学   142088篇
综合类   19020篇
一般理论   247篇
预防医学   64501篇
眼科学   20078篇
药学   63785篇
中国医学   1798篇
肿瘤学   49056篇
  2018年   9047篇
  2017年   7159篇
  2016年   7673篇
  2015年   8722篇
  2014年   12367篇
  2013年   19207篇
  2012年   25647篇
  2011年   27256篇
  2010年   16572篇
  2009年   15780篇
  2008年   26124篇
  2007年   27731篇
  2006年   27913篇
  2005年   27444篇
  2004年   26291篇
  2003年   25461篇
  2002年   25051篇
  2001年   41356篇
  2000年   42552篇
  1999年   36265篇
  1998年   9966篇
  1997年   9148篇
  1996年   9082篇
  1995年   8445篇
  1994年   8081篇
  1993年   7584篇
  1992年   28198篇
  1991年   26979篇
  1990年   26408篇
  1989年   25345篇
  1988年   23553篇
  1987年   23170篇
  1986年   22250篇
  1985年   21151篇
  1984年   15806篇
  1983年   13477篇
  1982年   8088篇
  1979年   14589篇
  1978年   10208篇
  1977年   8627篇
  1976年   8147篇
  1975年   8959篇
  1974年   10697篇
  1973年   10182篇
  1972年   9661篇
  1971年   8917篇
  1970年   8584篇
  1969年   8025篇
  1968年   7684篇
  1967年   7086篇
排序方式: 共有10000条查询结果,搜索用时 453 毫秒
861.
862.
The development of the artificial pancreas represents an important step forward in modern diabetology. The practical and theoretical findings obtained by its application to Type 1 (insulin-dependent) diabetic patients has given new insights into modes of insulin secretion, pathophysiology of diabetes mellitus, and new forms of treatment, i.e. the development of portable insulin pumps and intensified conventional insulin therapy. All of these therapies provided better results than conventional insulin administration. However, there is no doubt that the restoration of normoglycaemia in a real sense is obtainable only by an implantable artificial pancreas or pancreas transplantation. The development of the implantable artificial pancreas, on the other hand, is dependent upon the development of a reliably working permanently implantable glucose sensor. The first attempts in that direction have opened new vistas as to the differences between blood and interstitial tissue glucose measurements, displaying different modes of regulation under normal and pathologic conditions. A number of barriers have to be overcome until the final goal has been attained: to obtain, by automated blood glucose control, narrow glycaemic fluctuations of the normal subject, and to prevent, hopefully, relentless diabetic complications.  相似文献   
863.
A sample consisting of 1135 edentulous patients with clinically healthy denture bearing areas, was examined radiologically. It appears that the diagnostic yield is high whereas the expected radiation induced risk is low. Patients should therefore be examined radiologically prior to full denture construction.  相似文献   
864.
865.
Zusammenfassung In einem pulsatil mit Kochsalz durchströmten Modell der Femoralisgabel wurden Flussmessungen und Druckgradienten für Flussmengen von 170 bis 860 ml/min bei peripheren Widerständen von 232 bis 25 792 dyn s cm–5 über dem Superficialis- und Profundaabgang bei Stenosen von 1 cm Länge und Querschnittsverminderungen von 0% bis 100% gemessen. Bei grossen Flussmengen (800–860 ml/min) und kleinem peripheren Widerstand (<640 dyn s cm–5) lag die kritische Stenose am Profundaabgang bei 4,1 mm Durchmesser, für hohe periphere Widerstände (> 5 072 dyn s cm–5) bei 2,6 mm; bei kleinen Flussmengen (<400 ml/min) betrug der kritische Durchmesser 1,8 mm. Der nicht stenosierte Profundaabgang stellte für keine der Versuchsbedingungen ein strömungsdynamisches Hindernis dar.  相似文献   
866.
867.
The effect of long-term treatment with the calcium antagonist nisoldipine on development of hypertension, cardiac hypertrophy, and plasma levels of atrial natriuretic peptides (ANP) was determined in spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) of the same age. Measurement of immunoreactive ANP in plasma provided a sensitive marker for the severity of hypertension and the associated cardiac overload. Long-term treatment with nisoldipine prevented the development of hypertension, the associated heart failure, and the increase of plasma levels of ANP in SHR but had no effect on systolic blood pressure, heart weight, and plasma levels of ANP in WKY. In addition, nisoldipine had a therapeutic effect in old SHR with manifest cardiac failure in end-stage hypertension, as evidenced not only by the reduction of blood pressure but also by the reduction of cardiac hypertrophy, of elevated immunoreactive ANP in plasma, and of increased plasma renin activity.  相似文献   
868.
869.
We examined several possible causes for the high incidence of poor sensory acuity in the limbs of 176 patients with moderate to severe peripheral vascular insufficiency. We investigated the relationships of diabetes, alcoholism, and smoking, as well as the severity of peripheral vascular disease, to the integrity of basic sensory modalities such as two-point discrimination and perception of light touch. The presence or absence of diabetes exerted the strongest effect on peripheral sensation. In patients who did not have diabetes, sensation in the limbs was most strongly affected by whether the patient was an alcoholic. Smoking did not have a significant effect on limb sensation. Among nondiabetic, nonalcoholic patients, there was a weak residual effect related to the severity of the peripheral vascular insufficiency. Even among these patients, however, systemic factors predominated in determining the loss of sensation. We also examined the extent to which loss of sensation might be related to the development of ulcers. Among patients who were not diabetic, there was a highly significant relationship between loss of sensation and the presence of limb ulceration. Surprisingly, however, there was no discernable relationship between the presence of ulcers in diabetic patients and the degree of loss of peripheral sensation. This result suggests that a large percentage of ulcers seen in diabetic patients are not of neurogenic origin.  相似文献   
870.
The purpose of the study presented here was to assess medical students' perceptions of the weight given to scientific and humanistic values in their learning environment and to determine whether students' perceptions in a given school vary according to their level of medical training and personal characteristics. The study was conducted in 1979 via a mail questionnaire sent to a sample of 713 freshmen, juniors, and graduates from three U.S. medical schools; 82.2 percent responded. The results indicated that the students' perceptions of school values varied little according to the students' personal characteristics, such as sociodemographic and educational background, interests before medical training, and expected specialty choice. However, important differences were observed in students' perceptions of values emphasized to them at different schools. Preclinical and clinical students' perceptions of the importance given to scientific values were similar. As for humanistic values, significantly lower ratings were given by clinical students than preclinical students in two of the schools.  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