全文获取类型
收费全文 | 31509篇 |
免费 | 2647篇 |
国内免费 | 272篇 |
专业分类
耳鼻咽喉 | 320篇 |
儿科学 | 1110篇 |
妇产科学 | 704篇 |
基础医学 | 3654篇 |
口腔科学 | 659篇 |
临床医学 | 3021篇 |
内科学 | 6737篇 |
皮肤病学 | 552篇 |
神经病学 | 2410篇 |
特种医学 | 1111篇 |
外科学 | 4695篇 |
综合类 | 839篇 |
一般理论 | 14篇 |
预防医学 | 2082篇 |
眼科学 | 1312篇 |
药学 | 2402篇 |
1篇 | |
中国医学 | 131篇 |
肿瘤学 | 2674篇 |
出版年
2023年 | 220篇 |
2022年 | 344篇 |
2021年 | 742篇 |
2020年 | 473篇 |
2019年 | 701篇 |
2018年 | 802篇 |
2017年 | 571篇 |
2016年 | 661篇 |
2015年 | 753篇 |
2014年 | 1035篇 |
2013年 | 1227篇 |
2012年 | 1991篇 |
2011年 | 2047篇 |
2010年 | 1204篇 |
2009年 | 1049篇 |
2008年 | 1797篇 |
2007年 | 1793篇 |
2006年 | 1627篇 |
2005年 | 1564篇 |
2004年 | 1551篇 |
2003年 | 1374篇 |
2002年 | 1226篇 |
2001年 | 1144篇 |
2000年 | 1029篇 |
1999年 | 886篇 |
1998年 | 348篇 |
1997年 | 275篇 |
1996年 | 241篇 |
1995年 | 242篇 |
1994年 | 216篇 |
1993年 | 206篇 |
1992年 | 519篇 |
1991年 | 486篇 |
1990年 | 450篇 |
1989年 | 427篇 |
1988年 | 386篇 |
1987年 | 351篇 |
1986年 | 347篇 |
1985年 | 340篇 |
1984年 | 231篇 |
1983年 | 209篇 |
1982年 | 147篇 |
1981年 | 109篇 |
1980年 | 121篇 |
1979年 | 163篇 |
1978年 | 96篇 |
1977年 | 110篇 |
1976年 | 71篇 |
1974年 | 85篇 |
1973年 | 71篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
171.
172.
Despite improvements in surgical techniques, some complex bile duct strictures continue to present difficult management problems. Strictures recurring after previous biliary-enteric bypass, those associated with established biliary cirrhosis or coexistent malignancy, and those that follow hepatic resection may pose almost insuperable technical and physiological problems. Percutaneous transhepatic balloon dilatation will not solve all problems, but can help in some instances. Six patients are presented in whom this technique has been used in attempts to overcome particular problems. The strengths and weaknesses of the method are discussed. 相似文献
173.
174.
175.
176.
177.
A double-blinded study was conducted to compare the effects of mupirocin and tetracycline ointments in the treatment of skin infections. 111 patients were available for clinical assessment, of which 53 were treated with mupirocin and 58 treated with tetracycline. Clinically, both groups were improved, and there was no significant difference. Bacteriological assessment however revealed a better response to mupirocin. Staphylococcus aureus and Streptococcus pyogenes were the most common organisms isolated. 99% of Staphylococci were sensitive to mupirocin compared with 61% to tetracycline and 29% to penicillin G. 57% of Group A beta haemolytic Streptococci were resistant to tetracycline compared to 14% to mupirocin. Gram-negative organisms were mostly resistant to both preparations. No side effects were observed in both treatment groups. This study suggests that mupirocin is a safe and effective topical preparation for treating most of our common skin infections. 相似文献
178.
179.
IS Park H Kiyomoto F Alvarez YC Xu HE Abboud SL Abboud 《American journal of kidney diseases》1998,32(6):1000-1010
The renal insulin-like growth factor-I (IGF-I) system has been implicated in the pathogenesis of renal hypertrophy, altered hemodynamics, and extracellular matrix expansion associated with early diabetes. The relative abundance of IGF binding proteins (IGFBPs) in the renal microenvironment may modulate IGF-I actions. However, the precise IGFBPs expressed in the glomerular and tubulointerstitial compartments during diabetic renal growth have not been characterized. In the present study, in situ hybridization studies were performed to examine the expression of IGFBP-1 to -6 messenger RNAs (mRNAs) 3, 7, and 14 days after streptozotocin (STZ) injection in rats. In control, nondiabetic kidneys, all six IGFBP mRNAs were differentially expressed with a predominance of IGFBP-5. The onset of renal hypertrophy in STZ-induced diabetes was associated with a rapid and site-specific induction of IGFBP-1, -3, and -5 mRNAs. In contrast, basal expression of IGFBP-2, -4, and -6 mRNAs was not altered in diabetic rats. IGFBP-5 mRNA expression increased in diabetic glomeruli, cortical, and inner medullary peritubular interstitial cells at days 3, 7, and 14. Although normal glomeruli failed to express IGFBP-3, it was induced concomitantly with IGFBP-5 in diabetic glomeruli and cortical peritubular interstitial cells. IGFBP-1 mRNA levels also increased in cortical tubular cells at each time point tested. Peak induction of IGFBP-3 and -5 was observed at day 3, whereas IGFBP-1 was delayed until day 7. IGFBP-1, -3, and -5 mRNA levels declined by day 14, but remained persistently elevated above control. By immunoperoxidase staining, similar alterations in the pattern of IGFBP-3 and -5 protein expression were observed at each time point. The preferential and site-specific increase in IGFBP-1, -3, and -5 suggest that these IGFBPs may regulate the local autocrine and/or paracrine actions of IGF-I and contribute to the pathogenesis of the early manifestations of diabetic nephropathy. 相似文献
180.
X. Liu R. L. Phillips S. M. Resnick V. L. Villemagne D. F. Wong J. M. Stapleton E. D. London 《Acta neurologica Scandinavica》1995,92(1):83-90
Previous studies of cerebral structure in substance abusers yielded controversial results, largely due to issues of subject selection and/or limitations of experimental techniques. The purpose of the present study was to assess whether the ventricle-to-brain ratio (VBR), determined volumetrically by magnetic resonance imaging (MRI), differed in polysubstance abusers (n = 10), as compared with age-matched controls (n = 10). Subjects were male volunteers 21–39 years of age. The values of VBR in the polydrug abuse group were not larger than those in control group, nor was there any tendency toward relative ventriculomegaly in the substance abusers. Therefore, the present findings provide no evidence that polysubstance abuse produces abnormalities of gross brain structure in relatively young and physically healthy men. 相似文献