全文获取类型
收费全文 | 4432篇 |
免费 | 279篇 |
国内免费 | 113篇 |
专业分类
耳鼻咽喉 | 131篇 |
儿科学 | 120篇 |
妇产科学 | 101篇 |
基础医学 | 596篇 |
口腔科学 | 100篇 |
临床医学 | 407篇 |
内科学 | 892篇 |
皮肤病学 | 201篇 |
神经病学 | 290篇 |
特种医学 | 620篇 |
外国民族医学 | 1篇 |
外科学 | 579篇 |
综合类 | 59篇 |
预防医学 | 224篇 |
眼科学 | 28篇 |
药学 | 298篇 |
中国医学 | 2篇 |
肿瘤学 | 175篇 |
出版年
2023年 | 29篇 |
2021年 | 53篇 |
2020年 | 43篇 |
2019年 | 60篇 |
2018年 | 72篇 |
2017年 | 66篇 |
2016年 | 78篇 |
2015年 | 81篇 |
2014年 | 95篇 |
2013年 | 140篇 |
2012年 | 122篇 |
2011年 | 173篇 |
2010年 | 107篇 |
2009年 | 122篇 |
2008年 | 130篇 |
2007年 | 200篇 |
2006年 | 178篇 |
2005年 | 200篇 |
2004年 | 134篇 |
2003年 | 133篇 |
2002年 | 98篇 |
2001年 | 90篇 |
2000年 | 118篇 |
1999年 | 111篇 |
1998年 | 122篇 |
1997年 | 126篇 |
1996年 | 138篇 |
1995年 | 105篇 |
1994年 | 93篇 |
1993年 | 91篇 |
1992年 | 66篇 |
1991年 | 99篇 |
1990年 | 91篇 |
1989年 | 100篇 |
1988年 | 93篇 |
1987年 | 130篇 |
1986年 | 103篇 |
1985年 | 105篇 |
1984年 | 68篇 |
1983年 | 59篇 |
1982年 | 46篇 |
1981年 | 47篇 |
1980年 | 53篇 |
1979年 | 52篇 |
1978年 | 43篇 |
1977年 | 35篇 |
1976年 | 59篇 |
1975年 | 43篇 |
1974年 | 28篇 |
1973年 | 28篇 |
排序方式: 共有4824条查询结果,搜索用时 15 毫秒
1.
2.
Kragh Thomsen M. Rasmussen M. Fuursted K. 《世界核心医学期刊文摘》2006,2(9):2-22
2000年11月,作者得知从Aarhus大学医院皮肤科患者分离到的金黄色葡萄球菌对苯唑西林出现界线耐药(BORSA)。本文旨在描述其表型和基因型,并评估可能的传播途径以干预和阻止进一步蔓延。菌株由脉冲场凝胶电泳鉴定。几个感染控制方案的缺口显示患者间可直接或间接传播。皮肤屏障缺陷、皮肤病患者金黄色葡萄球菌的高携带率和院内双氯西林的高消耗率可促使传播。改善普通感染控制措施和重新评价院内抗生素政策后,该菌的暴发感染消失。 相似文献
3.
K Thomsen B J Riis J S Johansen C Christiansen P R?dbro 《Gynecological endocrinology》1987,1(2):169-175
Bone turnover before and after withdrawal of estrogen/gestagen treatment was studied in a randomized trial with 110 healthy female volunteers, who had passed a natural menopause 6 months to 3 years before the start of the study. Urinary excretion of intravenously injected 99m-technetium diphosphonate was measured as an index of bone turnover; plasma bone Gla protein and serum alkaline phosphatase were measured as indices of bone formation; and fasting urinary excretion of hydroxyproline and calcium were measured as estimates of bone resorption. During 2 years of hormone treatment, all variables decreased highly significantly (p less than 0.001) to a constant low level. Three months after withdrawal all variables increased highly significantly (p less than 0.001) towards, but not above, pretreatment and placebo levels. We conclude that withdrawal of estrogen/gestagen replacement therapy in postmenopausal women increases bone turnover, but not in excess of pretreatment values. This indicates that bone loss (after withdrawal) is similar to that seen in the placebo group and that a rebound phenomenon is unlikely. 相似文献
4.
U. Tage-Jensen P. Schlichting H. F. Thomsen G. Hybye Aa. C. Thomsen 《Liver international》1987,7(2):81-83
ABSTRACT— One hundred and fifty-four patients with histologically verified nonalcoholic chronic liver disease were randomized to azathioprine or prednisone treatment. After a median of 91 months observation time, the cause of death was assessed retrospectively. Autopsy was performed in 82% of 71 deaths. In the azathioprine group 33% (13/39) died from malignant neoplasia, and in the prednisone group (13%) (4/32) (p = 0.08). Considering a possible fatal outcome as a consequence of treatment, this finding urges caution in the long-term application of azathioprine at the usual dose level. 相似文献
5.
6.
Summary— To investigate if the functional alterations observed in resistance arteries of spontaneously hypertensive rats (SHRs) were also present at the coronary level, in vitro experiments were performed in mesenteric resistance arteries (MRA) and in right (RIC) and left interventricular coronary (LIC) arteries taken from 15–25-week-old SHR and age-matched Wistar Kyoto rats WKYs. Using a passive extension protocol, internal diameters corresponding to 100 mmHg intraluminal pressure (D100) were determined and vessels were set up to a normalized internal diameter (0.9 D100). SHR mesenteric resistance arteries had a significantly smaller diameter compared to WKY arteries, whereas both types of SHR coronary arteries had a greater diameter compared to those of WKY rats. In arteries in the absence of contracting agonist, nitro-L-arginine (NOLA, 100 μM) induced a progressive rise in basal tone, which could be reversed by subsequent addition of L-arginine (100 μM) but not D-arginine (100 μM). When expressed as percent of maximal contractions induced by agonists (noradrenaline, NA [10 μM] in MRA; serotonin, 5-HT [10 μM], in RIC and LIC), these contractions were significantly stronger in WKY compared to SHR coronary and mesenteric resistance arteries. In NA-precontracted MRA and 5HT-precontracted coronary arteries in the presence of indomethacin (10 μM), the magnitude of acetylcholine-induced maximal relaxations (expressed as percent of maximal contractions induced by agonists) was greater in WKY compared to SHR arteries. After a 30-min incubation period, NOLA (100 μM) completely inhibited relaxations induced by acetylcholine (0.01–10 μM) in all types of precontracted arteries. Subsequent additions of sodium nitroprusside, (SNP, 10 μM) induced complete relaxations in all preparations. These results show that a basal release of NO or NO-like compound by endothelial cells is present in isolated mesenteric resistance and coronary arteries of WKY rats and SHRs. The contribution of endothelium-derived relaxing factor-nitric oxide (EDRF-NO) to arterial tone was lower in MRA compared to coronary arteries in both strains and in SHR compared to WKY arteries. In the SHR preparations, the impaired relaxation induced by acetylcholine appeared to be due to a functional alteration of the endothelium in the presence of normal reactivity of the smooth muscle cells. 相似文献
7.
8.
9.
表小檗碱对α受体的作用 总被引:2,自引:0,他引:2
表小檗碱(epiberberine,EB)是从湖北产黄连(Coptis chinensis Franch)中提取的一种生物碱,属苯喹嗪类原小檗碱,对其药理作用的研究资料甚少,未见其对α肾上腺素体作用的报道。资料表明,许多原小檗碱类化合物有α受体阻滞作用,为从该类化合物中选择 相似文献
10.
Pyelography is superior to all other imaging techniques for the demonstration of fine detail in the pelveocalyceal system and the ureter. For almost 90 years it has been performed through a retrogradely inserted catheter, but during the recent 30 years antegrade injection via a transparenchymally inserted needle or catheter has become an accepted alternative, especially in case of a dilated upper urinary tract. Both methods have their advantages and their disadvantages. This article presents a review of indications, techniques, and complications. Furthermore, interventional procedures on the upper urinary tract--such as stent placement and balloon dilatation--are now handled by the radiologist, mainly through an antegrade approach. These therapeutic procedures are also reviewed. 相似文献