全文获取类型
收费全文 | 925554篇 |
免费 | 74844篇 |
国内免费 | 2012篇 |
专业分类
耳鼻咽喉 | 13274篇 |
儿科学 | 26562篇 |
妇产科学 | 26181篇 |
基础医学 | 132729篇 |
口腔科学 | 26799篇 |
临床医学 | 82006篇 |
内科学 | 178003篇 |
皮肤病学 | 17867篇 |
神经病学 | 76164篇 |
特种医学 | 37187篇 |
外国民族医学 | 172篇 |
外科学 | 144882篇 |
综合类 | 25379篇 |
现状与发展 | 2篇 |
一般理论 | 328篇 |
预防医学 | 72664篇 |
眼科学 | 22124篇 |
药学 | 68997篇 |
1篇 | |
中国医学 | 1662篇 |
肿瘤学 | 49427篇 |
出版年
2018年 | 8824篇 |
2016年 | 7758篇 |
2015年 | 9103篇 |
2014年 | 13181篇 |
2013年 | 19641篇 |
2012年 | 27332篇 |
2011年 | 28530篇 |
2010年 | 16523篇 |
2009年 | 15450篇 |
2008年 | 26853篇 |
2007年 | 29307篇 |
2006年 | 29112篇 |
2005年 | 28534篇 |
2004年 | 27921篇 |
2003年 | 26665篇 |
2002年 | 25603篇 |
2001年 | 36333篇 |
2000年 | 36834篇 |
1999年 | 31475篇 |
1998年 | 10001篇 |
1997年 | 9205篇 |
1996年 | 9035篇 |
1995年 | 8551篇 |
1994年 | 8149篇 |
1992年 | 26969篇 |
1991年 | 26379篇 |
1990年 | 25838篇 |
1989年 | 24911篇 |
1988年 | 23466篇 |
1987年 | 23056篇 |
1986年 | 21948篇 |
1985年 | 21310篇 |
1984年 | 16672篇 |
1983年 | 14293篇 |
1982年 | 9188篇 |
1981年 | 8525篇 |
1980年 | 7984篇 |
1979年 | 16917篇 |
1978年 | 12319篇 |
1977年 | 10348篇 |
1976年 | 9445篇 |
1975年 | 10237篇 |
1974年 | 12729篇 |
1973年 | 12213篇 |
1972年 | 11606篇 |
1971年 | 10742篇 |
1970年 | 10274篇 |
1969年 | 9945篇 |
1968年 | 8924篇 |
1967年 | 8247篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
T W Mattox R O Brown B A Boucher E A Buonpane T C Fabian R W Luther 《JPEN. Journal of parenteral and enteral nutrition》1988,12(6):592-596
The purpose of this study was to evaluate the use of serum fibronectin and serum somatomedin-C as nutritional markers during enteral nutrition support (ENS) of critically ill, traumatized patients using an enteral product containing high concentrations of branched-chain amino acids. Twelve critically injured patients received a standard enteral formula with 30 g of a 44% branched-chain amino acid supplement added to each liter of formula. Fibronectin concentration, somatomedin-C concentration, and nitrogen balance were measured on study days 1, 4, 7, 14, 21, 28 or until adequate oral intake began. Both fibronectin and somatomedin-C concentrations increased significantly from baseline by day 7 of ENS. Nitrogen balance increased significantly from baseline by day 4. On days 14 and 21, only somatomedin-C and nitrogen balance increased significantly from baseline. Nitrogen balance was significantly correlated with somatomedin-C concentration (r = 0.53, p less than 0.01), cumulative caloric intake (r = 0.68, p less than 0.01), and cumulative nitrogen intake (r = 0.72, p less than 0.01). The results of this study suggest that serum somatomedin-C is useful and serum fibronectin has potential in monitoring nutrition support response in critically ill, traumatized patients. 相似文献
993.
W B Pittard K M Geddes T A Picone 《JPEN. Journal of parenteral and enteral nutrition》1988,12(2):167-169
Amino acid concentrations were measured in the cord blood serum from neonates following 23-41 weeks gestation. These values were then correlated with the gestational age of the newborns. A significant (p less than 0.05) correlation was observed with the concentrations of six amino acids, and five of these correlations were negative. The significance of these normative data are discussed and compared with currently available cord blood aminogram data. 相似文献
994.
Elevation of prostaglandins and protein in the aqueous humor is an immediate response to Yag-laser anterior capsulotomy. There was a significant correlation between prostaglandins and thromboxane to the elevation of intraocular pressure. The elevation of protein concentration was proportional to the elevation of prostaglandin F1, but not to thromboxane. The biochemical changes in the aqueous humor were more severe as laser power was increased above 3 mj. While the role of prostaglandins in the elevation of intraocular pressure is uncertain, the present data recommend the selection of laser power below 3 mj to avoid pressure rise instead of inhibition of all prostaglandin synthesis by medication. 相似文献
995.
S E Wilson W M Bourne P C O'Brien R F Brubaker 《American journal of ophthalmology》1988,106(3):270-278
Using a two-dimensional scanning fluorophotometer, we studied 50 subjects with symmetric ocular involvement of Fuchs' dystrophy without epithelial edema. Twenty-six subjects with confluent or nearly confluent cornea gutata with increased corneal thickness and 24 subjects with mild to moderate cornea guttata with normal corneal thickness were compared to normal control subjects. There were no statistically significant differences in endothelial permeability between the three groups. Corneal thickness was significantly increased in the subjects with confluent to nearly confluent guttae, however. These results suggest that endothelial pump function may be affected in subjects with advanced cornea guttata with stromal edema. 相似文献
996.
We present three cases of Lyme disease, complicated by ocular manifestations. These included optic nerve abnormalities and corneal opacities. 相似文献
997.
998.
999.
1000.
Deborah Bray Preston Anthony R D'Augelli Cathy D Kassab Richard E Cain Frederick W Schulze Michael T Starks 《AIDS education and prevention》2004,16(4):291-303
Research investigating predictors of risky sexual behavior of rural MSM is sparse, even though the prevalence of HIV in rural areas has increased. This study explored two sets of predictors of 93 rural MSM's levels of risky sexual behavior: mental health variables and stigma emanating from men's family members, health care professionals, and people in the rural communities in which they live. Over 47% of the men were found to be at modified high to high risk. Logistic regression using a continuation logit model was used to test the relationship of the predictor variables and the four levels of risk. Findings indicate that self-esteem was predictive of the highest sexual risk behavior but not lower levels of risk. Stigma was predictive of modified high sexual risk when compared to low and no risk categories. No variables differentiated men at low risk from men at no risk. 相似文献