全文获取类型
收费全文 | 8527篇 |
免费 | 508篇 |
国内免费 | 36篇 |
专业分类
耳鼻咽喉 | 80篇 |
儿科学 | 191篇 |
妇产科学 | 219篇 |
基础医学 | 1208篇 |
口腔科学 | 588篇 |
临床医学 | 561篇 |
内科学 | 2052篇 |
皮肤病学 | 151篇 |
神经病学 | 841篇 |
特种医学 | 182篇 |
外科学 | 1144篇 |
综合类 | 45篇 |
一般理论 | 3篇 |
预防医学 | 653篇 |
眼科学 | 196篇 |
药学 | 476篇 |
中国医学 | 50篇 |
肿瘤学 | 431篇 |
出版年
2023年 | 67篇 |
2022年 | 182篇 |
2021年 | 376篇 |
2020年 | 212篇 |
2019年 | 283篇 |
2018年 | 325篇 |
2017年 | 198篇 |
2016年 | 213篇 |
2015年 | 302篇 |
2014年 | 407篇 |
2013年 | 515篇 |
2012年 | 701篇 |
2011年 | 806篇 |
2010年 | 388篇 |
2009年 | 340篇 |
2008年 | 576篇 |
2007年 | 527篇 |
2006年 | 531篇 |
2005年 | 440篇 |
2004年 | 381篇 |
2003年 | 338篇 |
2002年 | 307篇 |
2001年 | 56篇 |
2000年 | 58篇 |
1999年 | 52篇 |
1998年 | 49篇 |
1997年 | 33篇 |
1996年 | 29篇 |
1995年 | 20篇 |
1994年 | 19篇 |
1993年 | 19篇 |
1992年 | 34篇 |
1991年 | 24篇 |
1990年 | 14篇 |
1989年 | 29篇 |
1988年 | 18篇 |
1987年 | 21篇 |
1986年 | 8篇 |
1985年 | 18篇 |
1984年 | 10篇 |
1983年 | 19篇 |
1982年 | 12篇 |
1981年 | 10篇 |
1980年 | 9篇 |
1979年 | 10篇 |
1977年 | 6篇 |
1975年 | 9篇 |
1974年 | 6篇 |
1971年 | 7篇 |
1968年 | 7篇 |
排序方式: 共有9071条查询结果,搜索用时 15 毫秒
41.
42.
43.
44.
Marta L. Tamayo Cesar Maldonado Silvia L. Plaza Gustavo M. Alvira Gustavo E. Tamayo Marta Zambrano Jaime L. Frias Jaime E. Bernal 《Clinical genetics》1996,50(3):126-132
We describe the neurological evaluation and MRI analysis of 30 patients, belonging to 16 families with Usher syndrome (US) type I and type II (US1 and US2). In addition to the classic visual and audiological abnormalities seen in these patients, we observed abnormal gait in 88.9% of US1 and in 66.7% of US2 patients and abnormal coordination in 33.4% of US1, and in 58.3% of US2. Borderline mental retardation, depression or bipolar affective disorder were observed in 16.7% of US1 and 33.3% of US2 patients. MRI analysis showed cerebellar abnormalities in 50% of US 1 and 75% of US2 patients, but no clear correlation was observed between structural abnormalities and clinical findings. A pattern for the MRI classification of US patients is suggested. 相似文献
45.
Enteropathogenic Escherichia coli strains carrying genes encoding the PER-2 and TEM-116 extended-spectrum beta-lactamases isolated from children with diarrhea in Uruguay 总被引:2,自引:0,他引:2
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Vignoli R Varela G Mota MI Cordeiro NF Power P Ingold E Gadea P Sirok A Schelotto F Ayala JA Gutkind G 《Journal of clinical microbiology》2005,43(6):2940-2943
We studied 13 extended-spectrum beta-lactamase (ESBL)-producing enteropathogenic Escherichia coli isolates from children suffering acute diarrhea in Uruguay. ESBL characterization in crude extracts showed a single band at pI 5.4. PCR amplification and sequencing data allowed identification of blaPER-2 and blaTEM-116. Retrospective analysis suggests that these strains were disseminated in the community, even if unnoticed, prior to their access to the hospital environment more than a decade ago. 相似文献
46.
New microsatellite multiplex PCR for Candida albicans strain typing reveals microevolutionary changes 总被引:4,自引:0,他引:4
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Sampaio P Gusmão L Correia A Alves C Rodrigues AG Pina-Vaz C Amorim A Pais C 《Journal of clinical microbiology》2005,43(8):3869-3876
Five new microsatellite loci were described and characterized for use as molecular markers for the identification and genetic differentiation of Candida albicans strains. Following the typing of 72 unrelated clinical isolates, the analysis revealed that they were all polymorphic, presenting from 5 to 30 alleles and 8 to 46 different genotypes. The discriminatory power obtained by combining the information generated by three microsatellites used in a multiplex PCR amplification strategy was 0.99, the highest ever reported. The multiplex PCR was later used to test a total of 114 C. albicans strains, including multiple isolates from the same patient collected from different body locations and along episodes of vulvovaginal infections. Three different scenarios for strain relatedness were identified: (i) different isolates that were revealed to be the same strain, (ii) isolates that were the same strain but that apparently underwent a process of microevolution, and (iii) isolates that corresponded to different strains. Analysis of the microevolutionary changes between isolates from recurrent infections indicated that the genotype alterations observed could be the result of events that lead to the loss of heterozygosity (LOH). In one case of recurrent infection, LOH was observed at the CAI locus, and this could have been related to exposure to fluconazole, since such strains were exposed to this antifungal during treatment. The analysis of microsatellites by a multiplex PCR strategy was found to be a highly efficient tool for the rapid and accurate differentiation of C. albicans strains and adequate for the identification of fine microevolutionary events that could be related to strain microevolution in response to environmental stress conditions. 相似文献
47.
Under various clinical situations, it is desirable to modify the original treatment plan to better suit the clinical goals. In this work, a method to help physicians modify treatment plans based on their clinical preferences is proposed. The method uses a weighted quadratic dose objective function. The commonly used organ-/ROI-based weighting factors are expanded to a set of voxel-based weighting factors in order to obtain greater flexibility in treatment plan modification. Two different but equivalent modification schemes based on Rustem's quadratic programming algorithms--modification of a weighting matrix and modification of prescribed doses--are presented. Case studies demonstrated the effectiveness of the two methods with regard to their capability to fine-tune treatment plans. 相似文献
48.
49.
50.
Hamilton R. Correia Sandra C. Balseiro Elisabete R. Correia Paulo G. Mota Manuel L. De Areia 《American journal of human biology》2004,16(1):24-30
The plumpness of the human newborn has long been recognized as a trait in need of explanation among researchers. Using a linear regression analysis, we find that head circumference is significantly and positively associated with BMI at birth, after gestational age and birthlength were controlled for, in a sample of 1,069 healthy liveborn routinely delivered at the University Hospital of Coimbra (partial correlation r = 0.409, P < 0.0001). This significant association is consistent with the idea that newborn fatness is related to the higher need of lipids in newborn humans as an energetic and plastic substrate during its accelerated brain growth period. As birthweight and birth head size are associated with head size and cognitive abilities in childhood and adult life, it could be postulated that these cognitive abilities could have acted as selective pressure responsible for the newborn fatness increase in our lineage. Am. J. Hum. Biol. 16:24–30, 2004. © 2003 Wiley‐Liss, Inc. 相似文献