全文获取类型
收费全文 | 11466篇 |
免费 | 720篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 61篇 |
儿科学 | 482篇 |
妇产科学 | 323篇 |
基础医学 | 1056篇 |
口腔科学 | 75篇 |
临床医学 | 1847篇 |
内科学 | 1705篇 |
皮肤病学 | 184篇 |
神经病学 | 1086篇 |
特种医学 | 768篇 |
外科学 | 1335篇 |
综合类 | 106篇 |
一般理论 | 10篇 |
预防医学 | 1642篇 |
眼科学 | 90篇 |
药学 | 499篇 |
中国医学 | 3篇 |
肿瘤学 | 921篇 |
出版年
2023年 | 93篇 |
2022年 | 92篇 |
2021年 | 200篇 |
2020年 | 133篇 |
2019年 | 283篇 |
2018年 | 265篇 |
2017年 | 197篇 |
2016年 | 213篇 |
2015年 | 237篇 |
2014年 | 360篇 |
2013年 | 534篇 |
2012年 | 778篇 |
2011年 | 863篇 |
2010年 | 474篇 |
2009年 | 407篇 |
2008年 | 750篇 |
2007年 | 797篇 |
2006年 | 723篇 |
2005年 | 737篇 |
2004年 | 674篇 |
2003年 | 614篇 |
2002年 | 564篇 |
2001年 | 143篇 |
2000年 | 131篇 |
1999年 | 128篇 |
1998年 | 134篇 |
1997年 | 99篇 |
1996年 | 100篇 |
1995年 | 93篇 |
1994年 | 61篇 |
1993年 | 71篇 |
1992年 | 116篇 |
1991年 | 94篇 |
1990年 | 96篇 |
1989年 | 91篇 |
1988年 | 87篇 |
1987年 | 90篇 |
1986年 | 95篇 |
1985年 | 79篇 |
1984年 | 63篇 |
1983年 | 43篇 |
1982年 | 31篇 |
1981年 | 31篇 |
1980年 | 31篇 |
1979年 | 30篇 |
1978年 | 45篇 |
1977年 | 36篇 |
1976年 | 24篇 |
1975年 | 26篇 |
1974年 | 25篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
Anthony R. Flores Brittany E. Jewell Erika M. Versalovic Randall J. Olsen Beth A. Bachert Slawomir Lukomski James M. Musser 《Infection and immunity》2015,83(3):1122-1129
Group A Streptococcus (GAS) predominantly exists as a colonizer of the human oropharynx that occasionally breaches epithelial barriers to cause invasive diseases. Despite the frequency of GAS carriage, few investigations into the contributory molecular mechanisms exist. To this end, we identified a naturally occurring polymorphism in the gene encoding the streptococcal collagen-like protein A (SclA) in GAS carrier strains. All previously sequenced invasive serotype M3 GAS possess a premature stop codon in the sclA gene truncating the protein. The carrier polymorphism is predicted to restore SclA function and was infrequently identified by targeted DNA sequencing in invasive strains of the same serotype. We demonstrate that a strain with the carrier sclA allele expressed a full-length SclA protein, while the strain with the invasive sclA allele expressed a truncated variant. An isoallelic mutant invasive strain with the carrier sclA allele exhibited decreased virulence in a mouse model of invasive disease and decreased multiplication in human blood. Further, the isoallelic invasive strain with the carrier sclA allele persisted in the mouse nasopharynx and had increased adherence to cultured epithelial cells. Repair of the premature stop codon in the invasive sclA allele restored the ability to bind the extracellular matrix proteins laminin and cellular fibronectin. These data demonstrate that a mutation in GAS carrier strains increases adherence and decreases virulence and suggest selection against increased adherence in GAS invasive isolates. 相似文献
7.
John P. Sundberg Kathleen A. Silva Victoria E. Kennedy John J. Wilson Nicholas E. Gott Beth A. Sundberg Derry C. Roopenian 《Experimental dermatology》2019,28(9):1091-1093
2‐deoxy D‐glucose (2DG) was tested for efficacy in treating alopecia areata using the C3H/HeJ skin graft model. 2DG has proven to be efficacious in treatment of various mouse models of autoimmunity with minimal serious side effects noted. This agent has been shown to normalize abnormally activated T‐cell populations while also preventing cell surface expression of NKG2D; key factors defining alopecia areata disease progression. Daily oral ingestion of 2DG via drinking water to mice with patchy or diffuse alopecia areata for 16 weeks failed to prevent expansion of alopecia or cause regrowth of hair in treated mice. Histologically, there were no differences between treated and control groups. These results indicate that, while 2DG is effective for some autoimmune diseases, it was not efficacious for the cell‐mediated autoimmune mouse disease, alopecia areata. 相似文献
8.
9.
Beth Sundstrom 《Health communication》2016,31(1):91-101
This study employed qualitative methods, conducting 44 in-depth interviews with biological mothers of newborns to understand women’s perceptions and use of new media, mass media, and interpersonal communication channels in relation to health issues. Findings contribute to theoretical and practical understandings of the role of communication channels in diffusion of innovations theory. In particular, this study provides a foundation for the use of qualitative research to advance applications of diffusion of innovations theory. Results suggest that participants resisted mass media portrayals of women’s health. When faced with a health question, participants uniformly started with the Internet to “Google it up.” Findings suggest new media comprise a new communication channel with new rules, serving the functions of both personal and impersonal influence. In particular, pregnancy and the postpartum period emerged as a time when campaign planners can access women in new ways online. As a result, campaign planners could benefit from introducing new ideas online and capitalizing on the strength of weak ties favored in new media. Results expand the innovativeness/needs paradox in diffusion of innovations theory by elaborating on the role of new media to reach underserved populations. These findings provide an opportunity to better understand patient information seeking through the lens of diffusion of innovations theory. 相似文献
10.
Marlene L Hauck Susan M LaRue William P Petros Jean M Poulson Daohai Yu Ivan Spasojevic Amy F Pruitt Allison Klein Beth Case Donald E Thrall David Needham Mark W Dewhirst 《Clinical cancer research》2006,12(13):4004-4010
PURPOSE: To determine the maximum tolerated dose, dose-limiting toxicities, and pharmacokinetic characteristics of doxorubicin encapsulated in a low temperature sensitive liposome (LTSL) when given concurrently with local hyperthermia to canine solid tumors. EXPERIMENTAL DESIGN: Privately owned dogs with solid tumors (carcinomas or sarcomas) were treated. The tumors did not involve bone and were located at sites amenable to local hyperthermia. LTSL-doxorubicin was given (0.7-1.0 mg/kg i.v.) over 30 minutes during local tumor hyperthermia in a standard phase I dose escalation study. Three treatments, given 3 weeks apart, were scheduled. Toxicity was monitored for an additional month. Pharmacokinetics were evaluated during the first treatment cycle. RESULTS: Twenty-one patients were enrolled: 18 with sarcomas and 3 with carcinomas. Grade 4 neutropenia and acute death secondary to liver failure, possibly drug related, were the dose-limiting toxicities. The maximum tolerated dose was 0.93 mg/kg. Other toxicities, with the possible exception of renal damage, were consistent with those observed following free doxorubicin administration. Of the 20 dogs that received > or = 2 doses of LTSL-doxorubicin, 12 had stable disease, and 6 had a partial response to treatment. Pharmacokinetic variables were more similar to those of free doxorubicin than the marketed liposomal product. Tumor drug concentrations at a dose of 1.0 mg/kg averaged 9.12 +/- 6.17 ng/mg tissue. CONCLUSION: LTSL-doxorubicin offers a novel approach to improving drug delivery to solid tumors. It was well tolerated and resulted in favorable response profiles in these patients. Additional evaluation in human patients is warranted. 相似文献