全文获取类型
收费全文 | 2577篇 |
免费 | 161篇 |
国内免费 | 35篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 72篇 |
妇产科学 | 36篇 |
基础医学 | 294篇 |
口腔科学 | 31篇 |
临床医学 | 216篇 |
内科学 | 569篇 |
皮肤病学 | 27篇 |
神经病学 | 194篇 |
特种医学 | 81篇 |
外科学 | 294篇 |
综合类 | 90篇 |
一般理论 | 4篇 |
预防医学 | 178篇 |
眼科学 | 164篇 |
药学 | 162篇 |
中国医学 | 7篇 |
肿瘤学 | 328篇 |
出版年
2023年 | 14篇 |
2022年 | 18篇 |
2021年 | 62篇 |
2020年 | 33篇 |
2019年 | 56篇 |
2018年 | 50篇 |
2017年 | 55篇 |
2016年 | 44篇 |
2015年 | 53篇 |
2014年 | 83篇 |
2013年 | 120篇 |
2012年 | 130篇 |
2011年 | 170篇 |
2010年 | 92篇 |
2009年 | 86篇 |
2008年 | 127篇 |
2007年 | 149篇 |
2006年 | 119篇 |
2005年 | 145篇 |
2004年 | 141篇 |
2003年 | 133篇 |
2002年 | 107篇 |
2001年 | 119篇 |
2000年 | 73篇 |
1999年 | 58篇 |
1998年 | 34篇 |
1997年 | 42篇 |
1996年 | 37篇 |
1995年 | 19篇 |
1994年 | 33篇 |
1993年 | 21篇 |
1992年 | 34篇 |
1991年 | 37篇 |
1990年 | 12篇 |
1989年 | 31篇 |
1988年 | 35篇 |
1987年 | 24篇 |
1986年 | 29篇 |
1985年 | 19篇 |
1984年 | 17篇 |
1983年 | 9篇 |
1982年 | 12篇 |
1981年 | 16篇 |
1980年 | 9篇 |
1979年 | 12篇 |
1978年 | 8篇 |
1977年 | 7篇 |
1975年 | 5篇 |
1970年 | 5篇 |
1965年 | 3篇 |
排序方式: 共有2773条查询结果,搜索用时 0 毫秒
31.
Kenneth W Yip Joseph D Mocanu P Y Billie Au Gillian T Sleep Dolly Huang Pierre Busson Wen-Chen Yeh Ralph Gilbert Brian O'Sullivan Patrick Gullane Carlo Bastianutto Fei-Fei Liu 《Clinical cancer research》2005,11(22):8131-8144
PURPOSE: A wide variety of tumors depend on the dysregulation of Bcl-2 family proteins for survival. The resulting apoptotic block can often provide a mechanism for resistance to anticancer treatments, such as chemotherapy and radiation. This current study evaluates the efficacy of combining systemically delivered Bcl-2 phosphorothioate antisense (Bcl-2 ASO) and radiation for nasopharyngeal cancer therapy. RESULTS: Antisense uptake was unaffected by 0, 3, or 6 Gy radiation. Radiation decreased the fraction of viable C666-1 cells to 60%, with a further decrease to 40% in combination with Bcl-2 ASO. Despite a modest in vitro effect, Bcl-2 ASO alone caused the regression of established xenograft tumors in mice, extending survival by 15 days in a C666-1 and by 6 days in a C15 model. The survival times for mice treated with both Bcl-2 ASO and radiation increased by 52 days in C666-1 and by 20 days in C15 tumors. This combination resulted in a more-than-additive effect in C666-1 tumors. Less impressive gains observed in C15 tumors might be attributable to higher expression of antiapoptotic Bcl-2 family proteins and limited drug distribution in the tumor. Retreatment of C666-1 tumors with the Bcl-2 ASO-radiation combination, however, was effective, resulting in mice surviving for >80 days relative to untreated controls. CONCLUSIONS: Our results show that the Bcl-2 ASO and radiation combination is a highly potent therapy for nasopharyngeal cancer. Further examination of combination therapy with radiation and other Bcl-2 family-targeted anticancer agents in both preclinical and clinical settings is definitely warranted. 相似文献
32.
33.
Yong VK Netto PA Heng WJ Yap EY Lee HM Ng MM Au Eong KG 《European journal of ophthalmology》2003,13(2):147-150
PURPOSE: To describe the clinic-pathological analysis of the visually significant opacification of the Cirrus International Hydroflex foldable hydrophilic acrylic intraocular lens (IOL) (model SC600-2, Medical Developmental Research Inc., Clearwater, Florida) and to highlight that this IOL is the same model as the Acryflex SC600-2 IOL, by the same manufacturer. METHODS: Retrospective review of five eyes of four patients with opacification of their Cirrus International Hydroflex foldable hydrophilic acrylic IOLs (model SC600-2) after uncomplicated phacoemulsification and IOL implantation. Two IOLs were explanted from two patients 14 to 24 months after initial implantation. Each explanted lens was divided into equal halves, one half for scanning electron microscopy (SEM) study and the other half for transmission electron microscopy (TEM) examination. SEM and TEM samples were also subjected to energy dispersive X-ray analysis (EDX). RESULTS: The IOL opacification was detected 14 to 24 months after uncomplicated phacoemulsification and IOL implantation. EDX analysis showed that the crystals contained calcium and phosphorus, presumably calcium phosphate. CONCLUSIONS: The Cirrus International Hydroflex foldable hydrophilic acrylic IOL (model SC600-2) is associated with opacification, that appeared worse centrally than peripherally. This is the same model as the Acryflex SC600-2 IOL, made by the same manufacturer. The opacification consists of calcium and phosphate. 相似文献
34.
Immunomodulatory and anti-SARS activities of Houttuynia cordata 总被引:1,自引:0,他引:1
Lau KM Lee KM Koon CM Cheung CS Lau CP Ho HM Lee MY Au SW Cheng CH Lau CB Tsui SK Wan DC Waye MM Wong KB Wong CK Lam CW Leung PC Fung KP 《Journal of ethnopharmacology》2008,118(1):79-85
BACKGROUND: Severe acute respiratory syndrome (SARS) is a life-threatening form of pneumonia caused by SARS coronavirus (SARS-CoV). From late 2002 to mid 2003, it infected more than 8000 people worldwide, of which a majority of cases were found in China. Owing to the absence of definitive therapeutic Western medicines, Houttuynia cordata Thunb. (Saururaceae)(HC) was shortlisted by Chinese scientists to tackle SARS problem as it is conventionally used to treat pneumonia. AIM OF THE STUDY: The present study aimed to explore the SARS-preventing mechanisms of HC in the immunological and anti-viral aspects. RESULTS: Results showed that HC water extract could stimulate the proliferation of mouse splenic lymphocytes significantly and dose-dependently. By flow cytometry, it was revealed that HC increased the proportion of CD4(+) and CD8(+) T cells. Moreover, it caused a significant increase in the secretion of IL-2 and IL-10 by mouse splenic lymphocytes. In the anti-viral aspect, HC exhibited significant inhibitory effects on SARS-CoV 3C-like protease (3CL(pro)) and RNA-dependent RNA polymerase (RdRp). On the other hand, oral acute toxicity test demonstrated that HC was non-toxic to laboratory animals following oral administration at 16 g/kg. CONCLUSION: The results of this study provided scientific data to support the efficient and safe use of HC to combat SARS. 相似文献
35.
Effects of Cadmium and Phenol on Motility and Ultrastructure of Sea Urchin and Mussel Spermatozoa 总被引:8,自引:0,他引:8
Computer-assisted sperm analysis (CASA) was used to study the effects of Cd(II) and phenol on sperm motility of sea urchin
and mussel. In parallel, ultrastructural changes of sperm induced by these two toxicants were also investigated and related
to motility impairment. Spermatozoa of sea urchin were more sensitive than mussel spermatozoa to both toxicants. Sea urchin
sperm motility showed a good dose-response relationship to Cd(II) levels as well as exposure time. Exposure to the two toxicants
changed the size and shape of the midpiece, which might affect the balance of spermatozoa in their swimming. The plasma membrane
became more convoluted, and such a change might affect the streamlining and integrity of spermatozoa and hinder their normal
movement patterns. Most important, disorganization of mitochondrial membranes and cristae was observed, suggesting disruption
of ATP supply for sperm movement. Cadmium also induced greater ultrastructural damages in sea urchin spermatozoa.
Received: 8 March 1999/Accepted: 29 September 1999 相似文献
36.
37.
A recent wave of pharmacologic and technologic innovations has revolutionized our management of retinal diseases. Many of these advancements have demonstrated efficacy and can increase the quality of life while potentially reducing complications and decreasing the burden of care for patients. Some advances, such as longer-acting anti-vascular endothelial growth factor agents, port delivery systems, gene therapy, and retinal prosthetics have been approved by the US Food and Drug Administration, and are available for clinical use. Countless other therapeutics are in various stages of development, promising a bright future for further improvements in the management of the retinal disease. Herein, we have highlighted several important novel therapies and therapeutic approaches and examine the opportunities and limitations offered by these innovations at the new frontier.
KEY MESSAGES
- Numerous pharmacologic and technologic advancements have been emerging, providing a higher treatment efficacy while decreasing the burden and associated side effects.
- Anti-vascular endothelial growth factor (anti-VEGF) and its longer-acting agents have dramatically improved visual outcomes and have become a mainstay treatment in various retinal diseases.
- Gene therapy and retinal prosthesis implantation in the treatment of congenital retinal dystrophy can accomplish the partial restoration of vision and improved daily function in patients with blindness, an unprecedented success in the field of retina.
38.
39.
40.
Au R Seshadri S Wolf PA Elias M Elias P Sullivan L Beiser A D'Agostino RB 《Experimental aging research》2004,30(4):333-358
A previous publication presented normative data on neuropsychological tests stratified by age, gender, and education based on the Original Cohort of the Framingham Heart Study. Many contemporary investigations include subject samples with higher levels of education, a factor known to affect cognitive performance. Secular change in education prompted the reexamination of norms in the children of the Original Cohort. The study population consisted of 853 men and 988 women from the Offspring Study, free of clinical neurological disease, who underwent a neuropsychological examination, which included tests given to their parents in 1974 to 1976 as well as additional newer tests to provide a more comprehensive battery. The Offspring population overall was more evenly distributed by gender and better educated. Their performance on cognitive tests was superior to that of the Original Cohort. Multivariable analyses revealed that more years of education explained only a part of the cohort differences. These findings suggest that continued surveillance of each generation is necessary to document the impact that unique social and economic variables have on cognitive function. Here, the authors provide updated normative data. 相似文献