全文获取类型
收费全文 | 188005篇 |
免费 | 5583篇 |
国内免费 | 2253篇 |
专业分类
耳鼻咽喉 | 1836篇 |
儿科学 | 6885篇 |
妇产科学 | 3083篇 |
基础医学 | 22862篇 |
口腔科学 | 5281篇 |
临床医学 | 12770篇 |
内科学 | 35660篇 |
皮肤病学 | 3406篇 |
神经病学 | 11541篇 |
特种医学 | 4708篇 |
外国民族医学 | 5篇 |
外科学 | 28777篇 |
综合类 | 11457篇 |
现状与发展 | 3篇 |
一般理论 | 4篇 |
预防医学 | 11087篇 |
眼科学 | 3549篇 |
药学 | 19925篇 |
35篇 | |
中国医学 | 6541篇 |
肿瘤学 | 6426篇 |
出版年
2023年 | 1031篇 |
2022年 | 2398篇 |
2021年 | 3726篇 |
2020年 | 2345篇 |
2019年 | 13822篇 |
2018年 | 13544篇 |
2017年 | 6496篇 |
2016年 | 2017篇 |
2015年 | 2065篇 |
2014年 | 4248篇 |
2013年 | 5944篇 |
2012年 | 3753篇 |
2011年 | 3883篇 |
2010年 | 3287篇 |
2009年 | 3385篇 |
2008年 | 3704篇 |
2007年 | 4673篇 |
2006年 | 4920篇 |
2005年 | 4673篇 |
2004年 | 3732篇 |
2003年 | 3841篇 |
2002年 | 3567篇 |
2001年 | 3507篇 |
2000年 | 3725篇 |
1999年 | 3365篇 |
1998年 | 3345篇 |
1997年 | 2664篇 |
1996年 | 2497篇 |
1995年 | 2782篇 |
1994年 | 2584篇 |
1993年 | 2001篇 |
1992年 | 1584篇 |
1991年 | 1590篇 |
1990年 | 1316篇 |
1989年 | 1059篇 |
1988年 | 1096篇 |
1987年 | 1038篇 |
1985年 | 5469篇 |
1984年 | 7337篇 |
1983年 | 5876篇 |
1982年 | 6312篇 |
1981年 | 5753篇 |
1980年 | 4939篇 |
1979年 | 5002篇 |
1978年 | 4088篇 |
1977年 | 3074篇 |
1976年 | 3547篇 |
1975年 | 2749篇 |
1974年 | 2533篇 |
1973年 | 2242篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
S B Wieslander B T Mortensen L Binderup N I Nissen 《European journal of haematology》1987,39(1):35-38
10 patients with CLL and 2 with CML were treated with gradually increasing doses of 1 alpha(OH)D3, up to 4 micrograms daily during 6 wk. 3 patients with preleukemia and 1 with myelofibrosis were treated with 2 micrograms daily of 1 alpha(OH)D3 for a prolonged period up to 17 wk. The treatment with 1 alpha (OH)D3 did not result in changes of disease parameters in any of the patients under study. Receptor studies for 1,25(OH)2D3 were performed in 8 CLL patients and revealed only 1 patient with increased specific receptor binding capacity. The maximum tolerable dose of 1 alpha(OH)D3 varied individually, but was in the range of 2-4 micrograms daily. 相似文献
32.
目的:优选散结消肿贴中大黄、重楼的渗漉提取工艺。方法:以总固体物得率和总蒽醌得率为指标,用正交实验优选。结果:工艺中影响最大的因素是乙醇浓度,其次是乙醇用量,浸泡时间影响较小。最佳工艺条件为乙醇浓度65%,乙醇用量8倍量。浸泡时间24h。结论:渗漉法操作简单,成份破坏少,用优选所得条件进行提取,总蒽醌和总固体物得率均较高,优选结果可用于散结消肿贴中大黄、重楼的提取。 相似文献
33.
蛇床子水提取液抑瘤作用的实验研究 总被引:13,自引:0,他引:13
目的 :研究蛇床子水提取液的体内抗肿瘤作用。方法 :通过 S180 肉瘤移植建立荷瘤小鼠模型 ,给予不同剂量蛇床子水提取液后观察 S180 荷瘤小鼠肿瘤生长曲线、血清唾液酸 (SA)、瘤重及小鼠生存天数的变化。结果 :蛇床子水提取液能明显抑制肿瘤生长 ,降低荷瘤小鼠血清 SA水平 ,0 .0 6mg/(g· d) ,0 .1 1 mg/(g· d)、0 .2 1 mg/(g· d)剂量组平均瘤重低于肿瘤对照组 (P<0 .0 5 ) ,抑瘤率依次为 2 3 .2 %、2 9.1 %和 2 4 .8%,且能延长荷瘤小鼠生存天数 (P<0 .0 1 ) ,动物生命延长率依次为 :2 6 .9%、3 4 .8%和 2 6 .6 %。结论 :蛇床子水提取液具有较强的抗肿瘤效应 ,有很好的利用前景 ,值得对其进行深入研究。 相似文献
34.
护理工作中院内感染相关问题与对策 总被引:5,自引:2,他引:3
目的 :提出护理工作与院内感染相关问题与对策。方法 :通过监测 ,找出护理工作引起院内感染存在的问题及薄弱环节 ,并制定相应对策。结果 :建立严格的控制感染的管理制度 ,层层落实把关 ,主动和独立地判断出行之有效的预防措施。结论 :在感染管理工作中严格认真执行消毒、灭菌、无菌操作 ,最大限度地避免因护理工作失误而引起的医院内感染 相似文献
35.
36.
研究亚硫酸氢钠和氯化钠配伍使用的增敏性,建立了NaHSO3—NaCl—KIO3—KI四元无机体系测定碘盐中碘含量的新方法。测定碘的最佳条件:磷酸介质,pH 3~4,最大吸收波长479 nm,ε479=1.5×105L/(mol/cm),碘含量(以KIO3中I计)在0~2.24mg/L内符合比尔定律。用于测定食盐中碘的含量,回收率为99.49%~101.3%,结果满意。 相似文献
37.
P. Nowakowski K. Ziaja T. Ludyga W. Kuczmik G. Biolik P. wik D. Ziaja 《Diseases of the esophagus》2007,20(4):358-360
Esophageus or gaster resection in patients with malignant disease is still a treatment of choice. It is obvious that each surgical procedure in these patients carries some possibility of complications. Esophageo-gastric or esophageo-jejuno anastomosis has a 4-27% frequency of fistula occurrence. All these result in 65% mortality in cases of poorer prognosis. The aim of this paper is not to present all types of complications but to objectively analyse the usefulness of the covered stent placement in the treatment of anastomotic fistulas. We present six patients who were treated for postoperative fistula of esophageo-gastric anastomosis (1 case) or esophageo-jejuno anastomosis (5 cases). All patients were treated with stapler suture for digestive tract reconstruction after malignancy removal during the primary surgical procedure. Signs and symptoms of suture leak between 5-8 days post-surgery were observed. Conservative therapy was not effective. Thus a new method of treatment was employed - covered stent placement. The procedure was performed under X-ray control. In all treated patients there was change for the better and quick reduction of secretion from the fistulas was observed. All patients were discharged from the department after several days and all had survived at 30 days follow-up. Covered esophageal stent placement seems to be a safe and promising method of treatment for patients with anastomotic fistula which significantly reduces mortality and improves quality of live. Our experiences confirms that of other investigators. 相似文献
38.
39.
目的观察中西医结合治疗慢性鼻窦炎的疗效.方法:对76例慢性鼻窦炎病人采用阿奇霉素,每次1粒(0.25g),替硝唑片每次1g口服,二者均一日1次,首剂量加倍,中成药藿胆丸每次服6克,一日两次,7天为一疗程,服药最长者2周。结果:显效56例(占73.7%),有效18例(占23.7%),无效2例(占2.6%),总有效率97.4%。结论:中西医结合治疗慢性鼻窦炎具有良好疗效。 相似文献
40.
Bodo Lehmann 《Experimental dermatology》2009,18(2):97-108
Abstract: Irradiation of human keratinocytes with UVB (280–320 nm) in vitro and in vivo activates the metabolism of 7‐dehydrocholesterol to hormonally active calcitriol. The production of calcitriol in the skin strongly depends on the photosynthesis of vitamin D3 which is biologically inactive in the first instance. Vitamin D3 serves as the starting substrate for two subsequent enzymatic hydroxylation steps in epidermal keratinocytes. Both the amount of vitamin D3 and the activity of anabolic and catabolic vitamin D hydroxylases determine the cutaneous level of calcitriol. The hormonally active metabolite of vitamin D3 regulates a huge number of genes in keratinocytes, and thus acts in an autocrine and/or paracrine manner. This local pathway of vitamin D3 is unique, but its relevance for healthy and diseased skin is widely unknown, yet. Experimental findings implicate several questions: ( 1 ) Is UVB‐induced formation of calcitriol involved in regulation of growth and differentaition of epidermal cells as well as immunological and skin protective processes? ( 2 ) What endogenous and exogenous factors including drugs affect the cutaneous vitamin D3 pathway? From a therapeutical point of view, it has been known for a long time that topical application of calcitriol and its analogs can improve hyperproliferative skin diseases like psoriasis. In spite of many encouraging studies in recent years, the fields of the routinely therapeutical application of calcitriol or vitamin D analogs in dermatology (e.g. treatment of immunological, inflammatory, malignancies and infectious skin diseases) have not been intensified. Why is that? 相似文献