全文获取类型
收费全文 | 124925篇 |
免费 | 10466篇 |
国内免费 | 5786篇 |
专业分类
耳鼻咽喉 | 881篇 |
儿科学 | 4199篇 |
妇产科学 | 3008篇 |
基础医学 | 14992篇 |
口腔科学 | 3121篇 |
临床医学 | 11595篇 |
内科学 | 19357篇 |
皮肤病学 | 1800篇 |
神经病学 | 9282篇 |
特种医学 | 2334篇 |
外国民族医学 | 38篇 |
外科学 | 10178篇 |
综合类 | 19926篇 |
现状与发展 | 20篇 |
预防医学 | 10795篇 |
眼科学 | 3327篇 |
药学 | 11870篇 |
39篇 | |
中国医学 | 4410篇 |
肿瘤学 | 10005篇 |
出版年
2024年 | 325篇 |
2023年 | 1512篇 |
2022年 | 3316篇 |
2021年 | 4382篇 |
2020年 | 3844篇 |
2019年 | 3609篇 |
2018年 | 3463篇 |
2017年 | 4018篇 |
2016年 | 4245篇 |
2015年 | 4321篇 |
2014年 | 7653篇 |
2013年 | 8914篇 |
2012年 | 7757篇 |
2011年 | 8728篇 |
2010年 | 7292篇 |
2009年 | 6855篇 |
2008年 | 7069篇 |
2007年 | 7060篇 |
2006年 | 6324篇 |
2005年 | 5665篇 |
2004年 | 4780篇 |
2003年 | 4156篇 |
2002年 | 3438篇 |
2001年 | 2997篇 |
2000年 | 2563篇 |
1999年 | 2174篇 |
1998年 | 1880篇 |
1997年 | 1672篇 |
1996年 | 1546篇 |
1995年 | 1371篇 |
1994年 | 1163篇 |
1993年 | 946篇 |
1992年 | 844篇 |
1991年 | 687篇 |
1990年 | 657篇 |
1989年 | 504篇 |
1988年 | 382篇 |
1987年 | 343篇 |
1986年 | 295篇 |
1985年 | 439篇 |
1984年 | 365篇 |
1983年 | 255篇 |
1982年 | 333篇 |
1981年 | 212篇 |
1980年 | 192篇 |
1979年 | 136篇 |
1978年 | 112篇 |
1977年 | 93篇 |
1976年 | 83篇 |
1975年 | 58篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
经临床鉴定静脉内注射小儿氨基酸对治疗胎儿宫内发育迟缓具有肯定效果。在B超监视下,使用小儿氨基酸的孕妇组于用药期间,胎儿生长参数BPD和HC显著高于使用成人氨基酸的孕妇组。10例足月娩出胎儿体重均达到甚至超过2.5kg。由此得出结论:使用小儿氨基酸注射液对于改善胎儿宫内发育迟缓优于成人氨基酸。 相似文献
52.
53.
H. Sonnenberg 《Pediatric nephrology (Berlin, Germany)》1990,4(4):354-357
The greater than 40-fold range of voluntary salt intake in humans requires corresponding adjustments in renal excretion to maintain balance. Although many mechanisms have been implicated in the regulation of salt output by the kidney, surprisingly little consideration has been given to their quantitative significance and possible interaction. This survey summarizes the effects of changes in glomerular filtration rate, proximal peritubular physical factors, and plasma concentrations of aldosterone and atrial natriuretic factor (ANF), singly and in combination, on the level of salt excretion. Contrary to expectation, even large increases in filtration or decreases in proximal reabsorption have only minor natriuretic effects, due to constancy of fractional reabsorption in downstream nephron segments. Lack of aldosterone release increases salt excretion as much or more than the upstream mechanisms, whereas ANF-induced inhibition of reabsorption in the medullary collccting duct has the largest effect. It may be concluded, therefore, that the potency of these natriuretic factors increases with distance along the nephron, even though each is operating on a progressively small tubular load. However, none of the mechanisms, in isolation, is sufficient to explain salt balance over the range of voluntary intake. Combination of factors demonstrates synergism rather than simple additivity, resulting in more than enough reserve capacity for salt excretion. 相似文献
54.
Estil Y. Strawn Jr. MD Miles J. Novy MD Kenneth A. Burry MD Cynthia L. Bethea PhD 《American journal of obstetrics and gynecology》1995,172(6):1837-1844
Objective: Our purpose was to determine whether insulin-like growth factors I and II preferentially stimulate uterine leiomyoma cells versus myometrial cells in monolayer culture.Study design: Leiomyomas and normal myometrium were obtained at hysterectomy from five premenopausal women. Specimens were enzymatically digested for use in primary monolayer cell cultures. By use of serum-free media, insulin-like growth factor I or II was added in 1, 10, and 100 ng/ml concentrations to both cell types with the patient serving as her own control. Cell number, prolactin production, and proliferative index values were measured on day 15 of cell culture.Results: Significant increases in cell number were found in the leiomyoma cultures (p < 0.05) treated with 10 and 100 ng/ml insulin-like growth factors I but not with insulin-like growth factos II. Neither factor exerted a stimulatory effect on myometrial cells.Conclusion: Insulin-like growth factor sI preferentially stimulates leiomyoma cells in monolayer culture. These results suggest an autocrine-paracine role in vivo for this factor in conjuction with gonadal steroids in promoting leiomyoma growth. 相似文献
55.
Association of Vascular Endothelial Growth Factor Expression with Tumor Angiogenesis and with Early Relapse in Primary Breast Cancer 总被引:10,自引:0,他引:10
Masakazu Toi Seigo Hoshina Toshiaki Takayanagi Takeshi Tominaga 《Cancer science》1994,85(10):1045-1049
Angiogenesis is an independent prognostic indicator in breast cancer. In this report, the relationship between expression of vascular endothclial growth factor (VEGF; a selective mitogen for endothelial cells) and the microvessel density was examined in 103 primary breast cancers. The expression of VEGF was evaluated by immunocytochemical staining using anti-VEGF antibody. The microvessel density, which was determined by immunostaining for factor VIII antigen, in VEGF-rich tumors was clearly higher than that in VEGF-poor tumors ( P <0.01). There was a good correlation between VEGF expression and the increment of microvessel density. Furthermore, postoperative survey demonstrated that the relapse-free survival rate of VEGF-rich tumors was significantly worse than that of VEGF-poor tumors. It was suggested that the expression of VEGF is closely associated with the promotion of angiogenesis and with early relapse in primary breast cancer. 相似文献
56.
57.
Anthropometric data on 110 myelomeningocele (MMC) subjects in relation to age, sex, level of lesion and ambulation were studied to investigate growth and the occurrence of obesity in MMC. In 52 subjects, indices of obesity were validated against body composition analysis of total body fat (%BF) using body potassium and body water techniques. Most subjects were short and light compared to reference data and became relatively shorter and heavier with age. Overall trunk growth was not affected by the level of lesion, but sitting height was affected by kyphoscoliosis. Arm spans were similar to reference data, but were significantly greater in wheelchair users. Leg length was greatest in those who walked. Body composition data showed excess adipose in many MMC subjects, this tendency increasing with age. When correlated with %BF determined from body composition analysis, common clinical indices of obesity had variable r values (wt/ht2 0.78; wt/sitting ht2 0.77; upper arm fat area 0.75; triceps skinfold 0.74; wt/arm span2 0.68, with the 4 skinfold method correlating best, 0.82). Anthropometric measures, taken with cognizance of level of disability and mobility, can accurately assess body growth and the occurrence of obesity in MMC. The influence of ambulatory activity in promoting normal growth is emphasized. 相似文献
58.
KILL AND CURE THE HOPE AND REALITY OF VIRUS INACTIVATION 总被引:2,自引:0,他引:2
CHRISTOPHER PROWSE 《Vox sanguinis》1994,67(S3):191-196
59.
60.