全文获取类型
收费全文 | 580篇 |
免费 | 26篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 9篇 |
妇产科学 | 27篇 |
基础医学 | 77篇 |
口腔科学 | 2篇 |
临床医学 | 61篇 |
内科学 | 123篇 |
皮肤病学 | 2篇 |
神经病学 | 38篇 |
特种医学 | 21篇 |
外国民族医学 | 1篇 |
外科学 | 67篇 |
综合类 | 4篇 |
预防医学 | 94篇 |
眼科学 | 8篇 |
药学 | 48篇 |
肿瘤学 | 22篇 |
出版年
2022年 | 5篇 |
2021年 | 8篇 |
2020年 | 5篇 |
2019年 | 10篇 |
2018年 | 14篇 |
2017年 | 15篇 |
2016年 | 10篇 |
2015年 | 10篇 |
2014年 | 28篇 |
2013年 | 28篇 |
2012年 | 48篇 |
2011年 | 58篇 |
2010年 | 19篇 |
2009年 | 11篇 |
2008年 | 47篇 |
2007年 | 43篇 |
2006年 | 44篇 |
2005年 | 42篇 |
2004年 | 35篇 |
2003年 | 47篇 |
2002年 | 39篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1984年 | 2篇 |
1980年 | 3篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有606条查询结果,搜索用时 15 毫秒
1.
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
2.
Effects of vitamin D and calcium supplementation on falls: a randomized controlled trial. 总被引:21,自引:0,他引:21
Heike A Bischoff Hannes B St?helin Walter Dick Regula Akos Margrith Knecht Christian Salis Matthias Nebiker Robert Theiler Michael Pfeifer Bettina Begerow Robert A Lew Martin Conzelmann 《Journal of bone and mineral research》2003,18(2):343-351
Specific receptors for vitamin D have been identified in human muscle tissue. Cross-sectional studies show that elderly persons with higher vitamin D serum levels have increased muscle strength and a lower number of falls. We hypothesized that vitamin D and calcium supplementation would improve musculoskeletal function and decrease falls. In a double-blind randomized controlled trial, we studied 122 elderly women (mean age, 85.3 years; range, 63-99 years) in long-stay geriatric care. Participants received 1200 mg calcium plus 800 IU cholecalciferol (Cal+D-group; n = 62) or 1200 mg calcium (Cal-group; n = 60) per day over a 12-week treatment period. The number of falls per person (0, 1, 2-5, 6-7, >7 falls) was compared between the treatment groups. In an intention to treat analysis, a Poisson regression model was used to compare falls after controlling for age, number of falls in a 6-week pretreatment period, and baseline 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D serum concentrations. Among fallers in the treatment period, crude excessive fall rate (treatment - pretreatment falls) was compared between treatment groups. Change in musculoskeletal function (summed score of knee flexor and extensor strength, grip strength, and the timed up&go test) was measured as a secondary outcome. Among subjects in the Cal+D-group, there were significant increases in median serum 25-hydroxyvitamin D (+71%) and 1,25-dihydroxyvitamin D (+8%). Before treatment, mean observed number of falls per person per week was 0.059 in the Cal+D-group and 0.056 in the Cal-group. In the 12-week treatment period, mean number of falls per person per week was 0.034 in the Cal+D-group and 0.076 in the Cal-group. After adjustment, Cal+D-treatment accounted for a 49% reduction of falls (95% CI, 14-71%; p < 0.01) based on the fall categories stated above. Among fallers of the treatment period, the crude average number of excessive falls was significantly higher in the Cal-group (p = 0.045). Musculoskeletal function improved significantly in the Cal+D-group (p = 0.0094). A single intervention with vitamin D plus calcium over a 3-month period reduced the risk of falling by 49% compared with calcium alone. Over this short-term intervention, recurrent fallers seem to benefit most by the treatment. The impact of vitamin D on falls might be explained by the observed improvement in musculoskeletal function. 相似文献
3.
4.
The fibre gene of the bovine adenovirus type 2 (BAdV2) subtype B was prepared for sequencing by using cloning, sub-cloning and PCR amplification techniques. The nucleotide sequence of the total fibre gene was determined, and it was found to consist of 1,647 nucleotides, coding for a polypeptide of 549 amino acids. The fibre gene regions of BAdV2 A and B subtypes were aligned. The nucleotide identity of the total fibre gene was found to be 60.5%; however, the homology showed great differences in the different subregions coding for the shaft and knob part of the fibre, and the two subtypes were almost identical in the tail subregion. Remarkable changes indicating deletion, insertion and point mutations were found in the shaft subregion when BAdV2/A and B subtypes were compared. We concluded that the differences found in the haemagglutinating activity of the two subtypes of BAdV2 can mostly be explained by the changes in the polypeptide structure of the fibre shaft. 相似文献
5.
6.
7.
8.
9.
10.
François Barbier Sébastien Bailly Carole Schwebel Laurent Papazian Élie Azoulay Hatem Kallel Shidasp Siami Laurent Argaud Guillaume Marcotte Benoît Misset Jean Reignier Michaël Darmon Jean-Ralph Zahar Dany Goldgran-Toledano Étienne de Montmollin Bertrand Souweine Bruno Mourvillier Jean-François Timsit for the OUTCOMEREA Study Group 《Intensive care medicine》2018,44(5):616-626