全文获取类型
收费全文 | 52864篇 |
免费 | 4323篇 |
国内免费 | 1604篇 |
专业分类
耳鼻咽喉 | 623篇 |
儿科学 | 635篇 |
妇产科学 | 1086篇 |
基础医学 | 8176篇 |
口腔科学 | 1419篇 |
临床医学 | 4443篇 |
内科学 | 10098篇 |
皮肤病学 | 1006篇 |
神经病学 | 3795篇 |
特种医学 | 1725篇 |
外国民族医学 | 7篇 |
外科学 | 7356篇 |
综合类 | 4080篇 |
现状与发展 | 1篇 |
一般理论 | 5篇 |
预防医学 | 3022篇 |
眼科学 | 1373篇 |
药学 | 4765篇 |
中国医学 | 785篇 |
肿瘤学 | 4391篇 |
出版年
2023年 | 206篇 |
2022年 | 350篇 |
2021年 | 594篇 |
2020年 | 379篇 |
2019年 | 648篇 |
2018年 | 1148篇 |
2017年 | 884篇 |
2016年 | 878篇 |
2015年 | 1011篇 |
2014年 | 1316篇 |
2013年 | 1599篇 |
2012年 | 2180篇 |
2011年 | 2119篇 |
2010年 | 1277篇 |
2009年 | 1287篇 |
2008年 | 1880篇 |
2007年 | 1968篇 |
2006年 | 1839篇 |
2005年 | 1503篇 |
2004年 | 1365篇 |
2003年 | 1341篇 |
2002年 | 1279篇 |
2001年 | 4640篇 |
2000年 | 4552篇 |
1999年 | 3913篇 |
1998年 | 1384篇 |
1997年 | 999篇 |
1996年 | 611篇 |
1995年 | 501篇 |
1994年 | 453篇 |
1993年 | 414篇 |
1992年 | 1932篇 |
1991年 | 1675篇 |
1990年 | 1528篇 |
1989年 | 1488篇 |
1988年 | 1296篇 |
1987年 | 1190篇 |
1986年 | 1063篇 |
1985年 | 899篇 |
1984年 | 588篇 |
1983年 | 467篇 |
1982年 | 249篇 |
1981年 | 180篇 |
1980年 | 141篇 |
1979年 | 280篇 |
1978年 | 77篇 |
1974年 | 75篇 |
1973年 | 95篇 |
1972年 | 71篇 |
1969年 | 66篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
J. R. Zahar M. Lecuit E. Carbonnelle F. Ribadeau-Dumas X. Nassif O. Lortholary 《Clinical microbiology and infection》2007,13(3):219-221
Until recently, most reported cases of bacteraemia caused by multidrug-resistant strains of Enterobacteriacae producing an extended-spectrum beta-lactamase (ESBL) in Europe have been nosocomial in origin. However, increasing numbers of reports of community-acquired bacteraemia and urinary tract infection caused by ESBL-producing microorganisms suggest that the geographical origin of patients should be taken into account as a risk-factor for possible ESBL production. Early identification of patients at high-risk of infection with ESBL-producing microorganisms, based on their geographical origin and travel history, should help to optimise initial antibiotic treatment strategies for severe urinary tract infections in Europe. 相似文献
92.
93.
J P Gérard J D Grange P Romestaing I Sentenac G De Laroche X Montbarbon M Mahe N Salerno J P Baude M Bonnet 《Annales de radiologie》1989,32(2):107-111
Following the experience of the German authors, the treatment of choroidal melanoma with ruthenium 106 disk was introduced in Lyon. Between 1983 and 1988, 127 patients were treated. Results are analysed on a group of 84 patients followed 18 months and more. In 72 cases a reduction of thickness was noted. It was complete in 33 cases. Enucleation was performed in 10 patients due to no response or regrowth. In 3 cases the tumor was sterilized. Five patients died of metastases, and 73 are alive, 3 of them with liver metastases. An afterloading iridium template disk was used in 8 patients. 4 of them with a tumor thickness between 6.5 and 8 mm had a good response. Edema of the fovea was observed in 21% of cases, while cataracts were very unusual with Ru 106. An enucleation was performed in 6 patients because of a complication. A useful vision may be preserved in 60% of cases. The scleral tolerance dose is close to 1,500 Gy. These results are in agreement with those of the literature and are considered to be satisfactory for tumors not exceeding 5 to 6 mm in thickness. If the tumor is located close to the fovea or the papilla, and/or if the thickness is 8 mm or more, proton beam could be a good alternative. 相似文献
94.
Analysis of 223 cases of hereditary deafness 总被引:1,自引:0,他引:1
95.
The xanthine oxidase catalysed release of superoxide free radicals (O2-) from endogenous hypoxanthine was determined in homogenates of synovium obtained from three groups of patients, those undergoing primary or revision total hip replacement (THR) for osteoarthritis and those undergoing arthroscopy of the knee for semilunar disc injuries. The concentrations of hypoxanthine in homogenates obtained during THR were found to be significantly higher than those in the group with semilunar disc injuries. The results suggest that there is a greater predisposition to free radical release and tissue damage in osteoarthritis. 相似文献
96.
97.
98.
M Robaszkiewicz E Hardy A Volant J B Nousbaum J M Cauvin G Calament F X Robert J P Saleun H Gouerou 《Gastroentérologie clinique et biologique》1991,15(10):703-710
Dysplasia is the only marker for malignant potential in Barrett's esophagus. The histologic interpretation of dysplasia is sometimes difficult, particularly when attempting to distinguish dysplastic changes from those of a regenerating and inflammatory mucosa. In order to find an objective marker to identify patients with high risk of malignant transformation, the authors evaluated 497 biopsies from 66 patients with Barrett's esophagus with flow cytometry. The aim of the study was to correlate DNA content and proliferative abnormalities with histology. All biopsies classified histologically as negative for dysplasia had a diploid DNA content. The percentage of biopsies with an aneuploid DNA content increased with the histologic grade of dysplasia: 2 percent of indefinite dysplasia, 11 percent of low grade dysplasia, 44 percent of high grade dysplasia and 78 percent of biopsy specimens with cancer biopsies were aneuploid. Mean S and G2M fractions of diploid biopsy specimens increased with the severity of histologic changes. The S and G2M fraction threshold values that could differentiate patients that were negative for dysplasia from those with high grade dysplasia or cancer were 9 percent and 6 percent, respectively. Aneuploidy or G2M fraction greater than 6 percent was the best discriminating criteria between those two distinct groups of patients. All 6 patients with high grade dysplasia or cancer had aneuploid cell populations or increased G2M fraction, whereas none of the 35 patients whose biopsies were histologically negative for dysplasia had evidence of genomic instability or increased G2M fraction. Flow cytometric abnormalities were found in 10 out of 25 patients whose biopsies were classified as indefinite for dysplasia or low grade dysplasia.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
99.
血液尿素氮是肾功能最重要的观测指标之一,是临床常规和急诊不可缺少的检验项目.尿素氮的测定方法,长期以来采用湿化学分析。如二乙酰—肟法,脲酶—吲哚酚法、脲酶—谷氨酸脱氢酶偶联法等.这些方法有足够的精确性和准确性,但需昂贵的仪器设备和专业技术人员,且操作繁琐又不能应急.干化学试剂以其用血微量、操作简便、快速、易于掌握和无需特殊仪器设备等优点有效地补充了湿试剂法之不足.国外已有尿素氮试纸法报道.50-93494专利技术是以脲酶、pH指示剂和屏障体组成的尿素氮试纸.此技术的特点是不用pH缓冲剂,而用多种高分子物质组成的屏障体来控制血液pH的影响.缺点是在试纸表面形成一坚硬的甲膜,使血样不易渗入试剂层,反应产生的颜色较浅,肉眼不易分辨. 相似文献
100.