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   1046055篇
  免费   80120篇
  国内免费   2707篇
耳鼻咽喉   13383篇
儿科学   35841篇
妇产科学   29332篇
基础医学   151994篇
口腔科学   28909篇
临床医学   96095篇
内科学   202947篇
皮肤病学   23667篇
神经病学   83350篇
特种医学   40440篇
外国民族医学   306篇
外科学   156061篇
综合类   24810篇
一般理论   411篇
预防医学   83178篇
眼科学   23582篇
药学   75962篇
  3篇
中国医学   2136篇
肿瘤学   56475篇
  2018年   11427篇
  2017年   8852篇
  2016年   10082篇
  2015年   11432篇
  2014年   15534篇
  2013年   23673篇
  2012年   31400篇
  2011年   33293篇
  2010年   19916篇
  2009年   18813篇
  2008年   31136篇
  2007年   32973篇
  2006年   33432篇
  2005年   32048篇
  2004年   31146篇
  2003年   29871篇
  2002年   28830篇
  2001年   48249篇
  2000年   49255篇
  1999年   41553篇
  1998年   11842篇
  1997年   10622篇
  1996年   10654篇
  1995年   10257篇
  1994年   9518篇
  1993年   8950篇
  1992年   33263篇
  1991年   32410篇
  1990年   31906篇
  1989年   30761篇
  1988年   27973篇
  1987年   28142篇
  1986年   26281篇
  1985年   25357篇
  1984年   19072篇
  1983年   16093篇
  1982年   9696篇
  1981年   8719篇
  1979年   17336篇
  1978年   12630篇
  1977年   10639篇
  1976年   10095篇
  1975年   10471篇
  1974年   12683篇
  1973年   12186篇
  1972年   11236篇
  1971年   10437篇
  1970年   9669篇
  1969年   9035篇
  1968年   8369篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
Three hundred and twenty samples of subgingival plaque were obtained from 80 caucasian girls, ranging from 10 to 13 years of age. The samples were analyzed to verify the influence of age upon colonization of the gingival sulcus by microorganisms potentially pathogenic to the periodontal tissues. The gingival and plaque status were evaluated through the gingival index (GI) and plaque index (PlI) and the microflora was assessed by the enzymatic method benzoyl-arginine-naphthylamide (BANA). The results of the BANA test were positive for 62.50% of the tested individuals and 40% of the examined sites. The influence of age was statistically significant on BANA reactivity, and the number of positive sites was greater at 11 (57.5%) than at 12 years (28.8%).  相似文献   
73.
Cerebral function in normoxia and its reactions to standard periods of hypoxia of increasing severity were studied in 30 newborn guinea pigs less than 3 days old. Intrauterine growth retardation was induced either by uterine artery ligation at midgestation or by feeding the female in late gestation with khat leaves, an amphetamine-like stimulant chewed by men and women in several countries in eastern Africa and Arabia. After spontaneous delivery, the neonates were anesthetized and ventilated. Cardiovascular, metabolic, and neurophysiologic (somatosensory evoked potentials) parameters were monitored. Under normoxia, the khat-exposed group showed prolonged latency of the primary response of the somatosensory evoked potentials and a reduced amount of secondary components. Under hypoxia, this group also has a greater reduction of amplitude of the somatosensory evoked potentials. It is concluded that khat exposure during fetal life has an impact on the cerebral function during the neonatal period (at least up to 3 days of age) which is not solely explained by the concomitantly produced growth retardation.  相似文献   
74.
Facial reanimation after acoustic neuroma excision is currently accomplished using a variety of surgical techniques. A multi-institutional survey of patient perceptions of facial reanimation success was accomplished by mailing a questionnaire to 809 randomly selected members of the Acoustic Neuroma Association. Four hundred sixty patients who underwent 296 reanimation procedures responded. Facial to hypoglossal nerve anastomosis, tarsorrhaphy, and upper eyelid implants were most frequently performed. The patient's estimations of initial deficit, spontaneous recovery, and overall satisfaction with the reanimation procedures are discussed.  相似文献   
75.
76.
77.
The epidemiologic correlation of chronic dietary salt intake among populations with the prevalence of hypertension has resulted in the concept that sodium plays an etiologic role in the development of essential hypertension (EH). However, the association of sodium intake with blood pressure in individuals within populations has been difficult to demonstrate. The differing human responses to sodium intake are dependent upon the individual level of sodium sensitivity or sodium resistance. Factors associated with sodium sensitivity are race, age, and other dietary factors. More recent investigations have pursued the interaction of sodium intake with other physiologic parameters including neurogenic activity, vascular structure, renal function, and other cations such as potassium and calcium. The observations that some humans demonstrate very little increase in blood pressure despite high levels of sodium intake supports the concept that a high sodium intake alone is not a single causal factor in hypertension. Sodium intake appears to interact with renal excretory capacity and vascular compliance. These varying physiologic functions must be delineated to characterize sodium sensitivity.  相似文献   
78.
In transmitting the body's weight, the ankle is subject to frequent static and dynamic injury due to concentrated stresses during standing and movement. The frequency of athletic ankle injuries ranges from 10 to 90 percent, with the highest rate occurring in basketball players. There is prolonged disability and recurrent instability for months to years for 25 to 40 per cent of these patients. Because most of this trauma is handled by primary care physicians, this review presents the mechanism of injury, relevant anatomy, physical examination, and appropriate therapeutic intervention in the acute and rehabilitative phases.  相似文献   
79.
Recurrent erosion   总被引:1,自引:0,他引:1  
  相似文献   
80.
Chorioretinal folds have been reported as a result of many intraocular and extraocular inflammatory processes or tumors. Visual loss is usually secondary to a combination of the underlying process and chorioretinal folds involving the macula. We report a patient who developed decreased vision, metamorphopsia, chorioretinal folds, and a lamellar macular hole secondary to global compression by a bone fragment. The chorioretinal folds regressed and his vision stabilized following surgical decompression. Chorioretinal folds and lamellar macular hold formation are previously unrecognized complications of reconstructive craniofacial surgery.  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