全文获取类型
收费全文 | 1977篇 |
免费 | 144篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 48篇 |
妇产科学 | 46篇 |
基础医学 | 311篇 |
口腔科学 | 38篇 |
临床医学 | 127篇 |
内科学 | 430篇 |
皮肤病学 | 70篇 |
神经病学 | 101篇 |
特种医学 | 68篇 |
外科学 | 259篇 |
综合类 | 107篇 |
一般理论 | 1篇 |
预防医学 | 105篇 |
眼科学 | 54篇 |
药学 | 145篇 |
中国医学 | 6篇 |
肿瘤学 | 191篇 |
出版年
2023年 | 11篇 |
2022年 | 28篇 |
2021年 | 58篇 |
2020年 | 40篇 |
2019年 | 48篇 |
2018年 | 55篇 |
2017年 | 28篇 |
2016年 | 39篇 |
2015年 | 61篇 |
2014年 | 88篇 |
2013年 | 88篇 |
2012年 | 109篇 |
2011年 | 139篇 |
2010年 | 80篇 |
2009年 | 67篇 |
2008年 | 92篇 |
2007年 | 98篇 |
2006年 | 98篇 |
2005年 | 100篇 |
2004年 | 79篇 |
2003年 | 70篇 |
2002年 | 55篇 |
2001年 | 55篇 |
2000年 | 48篇 |
1999年 | 38篇 |
1998年 | 16篇 |
1997年 | 17篇 |
1996年 | 13篇 |
1995年 | 7篇 |
1994年 | 12篇 |
1993年 | 9篇 |
1992年 | 24篇 |
1991年 | 31篇 |
1990年 | 24篇 |
1989年 | 21篇 |
1988年 | 18篇 |
1987年 | 18篇 |
1986年 | 20篇 |
1985年 | 24篇 |
1984年 | 14篇 |
1983年 | 12篇 |
1982年 | 11篇 |
1981年 | 8篇 |
1979年 | 15篇 |
1978年 | 14篇 |
1977年 | 9篇 |
1976年 | 18篇 |
1975年 | 25篇 |
1974年 | 18篇 |
1973年 | 12篇 |
排序方式: 共有2125条查询结果,搜索用时 15 毫秒
101.
102.
103.
Dilip K Sengupta SMH Mehdian Robert C Mulholland John K Webb Donna D Ohnmeiss 《BMC musculoskeletal disorders》2002,3(1):23-11
Background
Recent cadaver studies show stability against axial rotation with a cylindrical cage is marginally superior to a rectangular cage. The purpose of this biomechanical study in cadaver spine was to evaluate the stability of a new rectangular titanium cage design, which has teeth similar to the threads of cylindrical cages to engage the endplates.Methods
Ten motion segments (five L2-3, five L4-5) were tested. From each cadaver spine, one motion segment was fixed with a pair of cylindrical cages (BAK, Sulzer Medica) and the other with paired rectangular cages (Rotafix, Corin Spinal). Each specimen was tested in an unconstrained state, after cage introduction and after additional posterior translaminar screw fixation. The range of motion (ROM) in flexion-extension, lateral bending, and rotation was tested in a materials testing machine, with +/- 5 Nm cyclical load over 10 sec per cycle; data from the third cycle was captured for analysis.Results
ROM in all directions was significantly reduced (p < 0.05) with both types of cages. There was no significant difference in reduction of ROM in flexion-extension (p = 0.6) and rotation (p = 0.92) between the two cage groups, but stability in lateral bending was marginally superior with the rectangular cages (p = 0.11). Additional posterior fixation further reduced the ROM significantly (p < 0.05) in most directions in both cage groups, but did not show any difference between the cage groups.Conclusions
There was no significant difference in immediate stability in any direction between the threaded cylindrical cage and the new design of the rectangular cage with endplate teeth. 相似文献104.
105.
Genes involved in DNA repair and nitrosamine metabolism and those located on chromosome 14q32 are dysregulated in nasopharyngeal carcinoma. 总被引:2,自引:0,他引:2
Lori E Dodd Srikumar Sengupta I-How Chen Johan A den Boon Yu-Juen Cheng William Westra Michael A Newton Beth F Mittl Lisa McShane Chien-Jen Chen Paul Ahlquist Allan Hildesheim 《Cancer epidemiology, biomarkers & prevention》2006,15(11):2216-2225
Polymorphisms in nitrosamine metabolism, DNA repair, and immune response genes have been associated with nasopharyngeal carcinoma (NPC). Studies have suggested chromosomal regions involved in NPC. To shed light on NPC etiology, we evaluated host gene expression patterns in 31 NPC and 10 normal nasopharyngeal tissue specimens using the Affymetrix Human Genome U133 Plus 2.0 Array. We focused on genes in five a priori biological pathways and chromosomal locations. Rates of differential expression within these prespecified lists and overall were tested using a bootstrap method. Differential expression was observed for 7.6% of probe sets overall. Elevations in rate of differential expression were observed within the DNA repair (13.7%; P = 0.01) and nitrosamine metabolism (17.5%; P = 0.04) pathways. Differentially expressed probe sets within the DNA repair pathway were consistently overexpressed (93%), with strong effects observed for PRKDC, PCNA, and CHEK1. Differentially expressed probe sets within the nitrosamine metabolism pathway were consistently underexpressed (100%), with strong effects observed for NQ01, CYP2B6, and CYP2E1. No significant evidence of increases in rate of differential expression was seen within the immune/inflammatory pathway. A significant elevation in rate of differential expression was noted for chromosome 4p15.1-4q12 (13.0%; P = 0.04); both overexpression and underexpression were evident (38% and 62%, respectively). An elevation in the rate of differential expression on chromosome 14q32 was observed (11.3%; P = 0.06) with a consistent pattern of gene underexpression (100%; P < 0.0001). These effects were similar when excluding late-stage tumors. Our results suggest that nitrosamine activation and DNA repair are important in NPC. The consistent down-regulation of expression on chromosome 14q32 suggests loss of heterozygosity in this region. 相似文献
106.
107.
Sengupta S Jagadishchandra K Murty R Shivananda PG 《Indian journal of medical sciences》2000,54(4):149-150
A 25 year old male student presented with a discharging sinus and swelling over right forearm, which on culture yielded S. typhi, sensitive to Ciprofloxacin. Predisposing factors were absent but there was a history of surgery for chronic osteomyelitis of right ulna and injury with cricket ball at same site. Pus obtained during surgery was sterile. Patient responded to oral Ciprofloxacin. Soft tissue infections are uncommon manifestation of salmonellosis. This case is an unusual presentation of post-operative Salmonella typhi wound infection. 相似文献
108.
Somnath Saha Saibal Mishra D. D. Chakraborty Subhabrata Sengupta A. R. Mondal 《Indian journal of otolaryngology and head and neck surgery》2008,60(1):37-40
Foreign body impaction in aero digestive tract in infancy is difficult to diagnose sometimes. In this review of five unusual
cases of occult foreign body impaction in aero digestive tract has been presented and their management discussed 相似文献
109.
110.