全文获取类型
收费全文 | 1595576篇 |
免费 | 115732篇 |
国内免费 | 3643篇 |
专业分类
耳鼻咽喉 | 20989篇 |
儿科学 | 53696篇 |
妇产科学 | 43408篇 |
基础医学 | 238126篇 |
口腔科学 | 45334篇 |
临床医学 | 144711篇 |
内科学 | 305577篇 |
皮肤病学 | 36439篇 |
神经病学 | 121064篇 |
特种医学 | 60299篇 |
外国民族医学 | 376篇 |
外科学 | 238155篇 |
综合类 | 36363篇 |
现状与发展 | 2篇 |
一般理论 | 522篇 |
预防医学 | 121892篇 |
眼科学 | 36894篇 |
药学 | 117867篇 |
6篇 | |
中国医学 | 4117篇 |
肿瘤学 | 89114篇 |
出版年
2018年 | 17099篇 |
2017年 | 13302篇 |
2016年 | 14997篇 |
2015年 | 16790篇 |
2014年 | 22927篇 |
2013年 | 34874篇 |
2012年 | 46100篇 |
2011年 | 48870篇 |
2010年 | 29158篇 |
2009年 | 27466篇 |
2008年 | 45567篇 |
2007年 | 48657篇 |
2006年 | 49378篇 |
2005年 | 46904篇 |
2004年 | 45798篇 |
2003年 | 43898篇 |
2002年 | 42528篇 |
2001年 | 76922篇 |
2000年 | 78804篇 |
1999年 | 65518篇 |
1998年 | 17927篇 |
1997年 | 15681篇 |
1996年 | 16000篇 |
1995年 | 15246篇 |
1994年 | 14098篇 |
1993年 | 13147篇 |
1992年 | 51539篇 |
1991年 | 50597篇 |
1990年 | 49651篇 |
1989年 | 48498篇 |
1988年 | 44135篇 |
1987年 | 43662篇 |
1986年 | 41025篇 |
1985年 | 39379篇 |
1984年 | 29169篇 |
1983年 | 24652篇 |
1982年 | 14299篇 |
1981年 | 12826篇 |
1979年 | 26761篇 |
1978年 | 19161篇 |
1977年 | 16134篇 |
1976年 | 15398篇 |
1975年 | 16481篇 |
1974年 | 19682篇 |
1973年 | 18891篇 |
1972年 | 17582篇 |
1971年 | 16304篇 |
1970年 | 15397篇 |
1969年 | 14303篇 |
1968年 | 13203篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
102.
103.
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
104.
105.
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
106.
107.
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
108.
109.
110.
B Falkner 《Journal of the American College of Nutrition》1988,7(1):35-41
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