全文获取类型
收费全文 | 38328篇 |
免费 | 3045篇 |
国内免费 | 81篇 |
专业分类
耳鼻咽喉 | 291篇 |
儿科学 | 1706篇 |
妇产科学 | 1184篇 |
基础医学 | 5186篇 |
口腔科学 | 401篇 |
临床医学 | 4651篇 |
内科学 | 7011篇 |
皮肤病学 | 681篇 |
神经病学 | 4514篇 |
特种医学 | 722篇 |
外科学 | 3710篇 |
综合类 | 354篇 |
现状与发展 | 1篇 |
一般理论 | 74篇 |
预防医学 | 5222篇 |
眼科学 | 596篇 |
药学 | 2504篇 |
中国医学 | 35篇 |
肿瘤学 | 2611篇 |
出版年
2024年 | 81篇 |
2023年 | 618篇 |
2022年 | 989篇 |
2021年 | 1952篇 |
2020年 | 1156篇 |
2019年 | 1674篇 |
2018年 | 1880篇 |
2017年 | 1271篇 |
2016年 | 1438篇 |
2015年 | 1494篇 |
2014年 | 1961篇 |
2013年 | 2459篇 |
2012年 | 3565篇 |
2011年 | 3448篇 |
2010年 | 1726篇 |
2009年 | 1483篇 |
2008年 | 2275篇 |
2007年 | 2364篇 |
2006年 | 1998篇 |
2005年 | 1832篇 |
2004年 | 1566篇 |
2003年 | 1293篇 |
2002年 | 1164篇 |
2001年 | 146篇 |
2000年 | 107篇 |
1999年 | 176篇 |
1998年 | 230篇 |
1997年 | 136篇 |
1996年 | 114篇 |
1995年 | 114篇 |
1994年 | 106篇 |
1993年 | 96篇 |
1992年 | 53篇 |
1991年 | 45篇 |
1990年 | 40篇 |
1989年 | 29篇 |
1988年 | 24篇 |
1987年 | 23篇 |
1986年 | 28篇 |
1985年 | 31篇 |
1984年 | 30篇 |
1983年 | 24篇 |
1982年 | 25篇 |
1981年 | 26篇 |
1980年 | 29篇 |
1979年 | 17篇 |
1978年 | 15篇 |
1977年 | 10篇 |
1974年 | 8篇 |
1972年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Monica Conciatori Christopher J Stodgell Susan L Hyman Melanie O'Bara Roberto Militerni Carmela Bravaccio Simona Trillo Francesco Montecchi Cindy Schneider Raun Melmed Maurizio Elia Lori Crawford Sarah J Spence Lucianna Muscarella Vito Guarnieri Leonardo D'Agruma Alessandro Quattrone Leopoldo Zelante Daniel Rabinowitz Tiziana Pascucci Stefano Puglisi-Allegra Karl-Ludvig Reichelt Patricia M Rodier Antonio M Persico 《Neuropsychopharmacology》2004,55(4):413-419
BACKGROUND: The HOXA1 gene plays a major role in brainstem and cranial morphogenesis. The G allele of the HOXA1 A218G polymorphism has been previously found associated with autism. METHODS: We performed case-control and family-based association analyses, contrasting 127 autistic patients with 174 ethnically matched controls, and assessing for allelic transmission disequilibrium in 189 complete trios. RESULTS: A, and not G, alleles were associated with autism using both case-control (chi(2) = 8.96 and 5.71, 1 df, p <.005 and <.025 for genotypes and alleles, respectively), and family-based (transmission/disequilibrium test chi(2) = 8.80, 1 df, p <.005) association analyses. The head circumference of 31 patients carrying one or two copies of the G allele displayed significantly larger median values (95.0th vs. 82.5th percentile, p <.05) and dramatically reduced interindividual variability (p <.0001), compared with 166 patients carrying the A/A genotype. CONCLUSIONS: The HOXA1 A218G polymorphism explains approximately 5% of the variance in the head circumference of autistic patients and represents to our knowledge the first known gene variant providing sizable contributions to cranial morphology. The disease specificity of this finding is currently being investigated. Nonreplications in genetic linkage/association studies could partly stem from the dyshomogeneous distribution of an endophenotype morphologically defined by cranial circumference. 相似文献
22.
23.
David G Hicks Brian J Yoder Sarah Short Shannon Tarr Nichole Prescott Joseph P Crowe Andrea E Dawson G Thomas Budd Steven Sizemore Muzaffer Cicek Toni K Choueiri Raymond R Tubbs Daniel Gaile Norma Nowak Mary Ann Accavitti-Loper Andra R Frost Danny R Welch Graham Casey 《Clinical cancer research》2006,12(22):6702-6708
PURPOSE: This study aims to determine the effect of loss of breast cancer metastasis suppressor 1 (BRMS1) protein expression on disease-free survival in breast cancer patients stratified by estrogen receptor (ER), progesterone receptor (PR), or HER2 status, and to determine whether loss of BRMS1 protein expression correlated with genomic copy number changes. EXPERIMENTAL DESIGN: A tissue microarray immunohistochemical analysis was done on tumors of 238 newly diagnosed breast cancer patients who underwent surgery at the Cleveland Clinic between January 1, 1995 and December 31, 1996, and a comparison was made with 5-year clinical follow-up data. Genomic copy number changes were determined by array-based comparative genomic hybridization in 47 breast cancer cases from this population and compared with BRMS1 staining. RESULTS: BRMS1 protein expression was lost in nearly 25% of cases. Patients with tumors that were PR negative (P=0.006) or HER2 positive (P=0.039) and <50 years old at diagnosis (P=0.02) were more likely to be BRMS1 negative. No overall correlation between BRMS1 staining and disease-free survival was observed. A significant correlation, however, was seen between loss of BRMS1 protein expression and reduced disease-free survival when stratified by either loss of ER (P=0.008) or PR (P=0.029) or HER2 overexpression (P=0.026). Overall, there was poor correlation between BRMS1 protein staining and copy number status. CONCLUSIONS: These data suggest a mechanistic relationship between BRMS1 expression, hormone receptor status, and HER2 growth factor. BRMS1 staining could potentially be used in patient stratification in conjunction with other prognostic markers. Further, mechanisms other than genomic deletion account for loss of BRMS1 gene expression in breast tumors. 相似文献
24.
Scarlett Lin Gomez Cynthia D O'Malley Antoinette Stroup Sarah J Shema William A Satariano 《BMC cancer》2007,7(1):193
Background
Colorectal cancer, if detected early, has greater than 90% 5-year survival. However, survival has been shown to vary across racial/ethnic groups in the United States, despite the availability of early detection methods. 相似文献25.
26.
27.
28.
29.
HYPOTHESIS: Irrigation of the mastoid with a quinolone antibiotic-steroid solution may mitigate hearing loss caused by iatrogenic semicircular canal injury in the presence of Pseudomonas aeruginosa (PA) otitis media (OM). BACKGROUND: Studies have shown the cochlea to be more vulnerable to semicircular canal transection (SCT)-related hearing loss in the presence of PA OM. Prophylactic systemic antibiotics and steroids may decrease this hearing loss, but SCT is usually not planned. The aim of this study was to determine if irrigation with ciprofloxacin-dexamethasone (cipro-dex) could improve hearing outcomes following SCT in PA OM. METHODS: PA OM was induced in 28 animals. After three to five days, unilateral SCT was performed in each animal, with sham SCT on the contralateral ear. At surgery, half of the animals (n = 14) underwent irrigation of the both mastoid bullae with cipro-dex; the second group of animals (n = 14) underwent irrigation of the bullae with sterile saline. Auditory thresholds were obtained immediately prior to SCT and 7-10 days after SCT. RESULTS: SCT ears treated with cipro-dex showed a mean click threshold improvement of 4.6 dB from pre-transection to 7-10 days post-transection, whereas thresholds in the SCT ears treated with saline worsened by 7.5 dB (p = 0.15). CONCLUSION: Irrigation of the guinea pig bulla with cipro-dex following SCT in the setting of PA OM appears safe and may yield beneficial effects on hearing. 相似文献
30.