全文获取类型
收费全文 | 13366篇 |
免费 | 1192篇 |
国内免费 | 41篇 |
专业分类
耳鼻咽喉 | 204篇 |
儿科学 | 453篇 |
妇产科学 | 274篇 |
基础医学 | 2009篇 |
口腔科学 | 316篇 |
临床医学 | 1108篇 |
内科学 | 2723篇 |
皮肤病学 | 180篇 |
神经病学 | 1449篇 |
特种医学 | 461篇 |
外科学 | 2094篇 |
综合类 | 295篇 |
一般理论 | 12篇 |
预防医学 | 1132篇 |
眼科学 | 317篇 |
药学 | 874篇 |
中国医学 | 9篇 |
肿瘤学 | 689篇 |
出版年
2021年 | 170篇 |
2020年 | 98篇 |
2019年 | 175篇 |
2018年 | 194篇 |
2017年 | 139篇 |
2016年 | 135篇 |
2015年 | 168篇 |
2014年 | 266篇 |
2013年 | 485篇 |
2012年 | 596篇 |
2011年 | 647篇 |
2010年 | 407篇 |
2009年 | 332篇 |
2008年 | 702篇 |
2007年 | 710篇 |
2006年 | 724篇 |
2005年 | 742篇 |
2004年 | 765篇 |
2003年 | 769篇 |
2002年 | 727篇 |
2001年 | 216篇 |
2000年 | 183篇 |
1999年 | 216篇 |
1998年 | 188篇 |
1997年 | 167篇 |
1996年 | 154篇 |
1995年 | 156篇 |
1994年 | 161篇 |
1993年 | 145篇 |
1992年 | 213篇 |
1991年 | 182篇 |
1990年 | 173篇 |
1989年 | 191篇 |
1988年 | 187篇 |
1987年 | 138篇 |
1986年 | 190篇 |
1985年 | 197篇 |
1984年 | 192篇 |
1983年 | 179篇 |
1982年 | 174篇 |
1981年 | 191篇 |
1980年 | 169篇 |
1979年 | 115篇 |
1978年 | 152篇 |
1977年 | 102篇 |
1976年 | 124篇 |
1975年 | 129篇 |
1974年 | 101篇 |
1973年 | 108篇 |
1972年 | 75篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
62.
63.
64.
Infiltration is a frequent complication of intravenous therapy using peripheral venous lines in neonatal patients. In a randomized trial of two catheter materials, Vialon (Becton Dickinson) and Teflon (DuPont), we studied 19 putative risk factors for infiltration, including 11 infusates, in 772 peripheral venous lines in patients aged 1 to 67 days. The best-fit Cox regression model identified six significant predictors of infiltration (P less than .05): catheter material, age, anatomic insertion site, hyperalimentation, and use of furosemide and dopamine. For the subsample of patients weighing less than or equal to 1500 g, a second Cox regression model identified time spent inserting the catheter and the number of insertion attempts as additional significant predictors. These multivariate models showed that Vialon catheter material reduced the risk of infiltration by 18% (95% CI, 1% to 32% reduction) in the total sample and by 35% (95% CI, 15% to 50% reduction) in the higher risk low-weight (less than or equal to 1500 g) subsample. 相似文献
65.
R. M. Charnley W. M. Thomas J. Stanley D. L. Morris 《Annals of the Royal College of Surgeons of England》1992,74(2):138-141
Fasting serum gastrin concentrations were shown to be elevated in colorectal cancer patients compared with controls (P = 0.0037), which was mainly accounted for by a subgroup of patients who had significantly elevated levels. In cancer patients there was no difference in gastrin concentrations in blood taken from a tumour-draining mesenteric vein and from a peripheral vein at the time of colonic resection. Serum gastrin concentrations were significantly lower after apparently curative resection for colorectal cancer (P = 0.028), suggesting that the elevated serum gastrin seen in these patients may be due, at least in part, to secretion of gastrin by the tumour. 相似文献
66.
D Simeon B Stanley A Frances J J Mann R Winchel M Stanley 《The American journal of psychiatry》1992,149(2):221-226
OBJECTIVE: The goal of this study was to determine whether self-mutilators with personality disorders differ from nonmutilators with personality disorders in impulsivity, aggression, and other psychopathology and whether serotonergic dysfunction contributes to self-mutilation. METHOD: Twenty-six self-mutilators with personality disorders were matched to 26 control subjects with personality disorders for gender, age, education, axis I diagnosis of affective disorder, and axis II diagnosis of personality disorder. Numerous indexes of psychopathology as well as CSF 5-hydroxyindoleacetic acid (5-HIAA) levels and platelet imipramine binding sites (Bmax) and affinity (Kd) were determined. RESULTS: Self-mutilators had significantly more severe character pathology, had greater lifetime aggression, and were more antisocial than the control subjects. The self-mutilators scored higher on the Hamilton Rating Scale for Depression but not on the Beck Depression Inventory or the Beck Hopelessness Scale. The two groups did not differ on the Buss-Durkee Hostility and Guilt Inventory or on the Sensation Seeking Scale. The degree of self-mutilation was significantly correlated with impulsivity, chronic anger, and somatic anxiety. Both self-mutilation and impulsivity showed significant negative correlations with Bmax, although the two groups did not differ in CSF 5-HIAA levels or in platelet imipramine binding. CONCLUSIONS: The results demonstrate the contribution of severe character pathology, aggression, impulsivity, anxiety, and anger to self-mutilation and provide preliminary support for the hypothesis of underlying serotonergic dysfunction facilitating self-mutilation. 相似文献
67.
68.
69.
70.
J Miller J Bligh I Stanley A al Shehri 《The British journal of general practice》1998,48(432):1429-1432
Variations in levels of motivation to learn among established general practitioners (GPs) have received scant attention. Building on previous work, we present an analysis of factors contributing to the development of motivation to learn in those who are entering and already established in practice. This approach suggests that individual motivation is both complex and unstable in response to external factors. We draw attention to the possibility of motivational immaturity in recruits to general practice, the contribution of values, and the presence of demotivators. The implications of our analysis are explored in relation to individual professional development and continuing education provision. We suggest that motivational audit will identify individual and contextual factors that are reducing the capacity of GPs to continue learning. A number of approaches addressing these factors are proposed. 相似文献