全文获取类型
收费全文 | 8773篇 |
免费 | 928篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 124篇 |
儿科学 | 407篇 |
妇产科学 | 177篇 |
基础医学 | 1300篇 |
口腔科学 | 170篇 |
临床医学 | 959篇 |
内科学 | 1301篇 |
皮肤病学 | 119篇 |
神经病学 | 792篇 |
特种医学 | 331篇 |
外科学 | 1357篇 |
综合类 | 327篇 |
一般理论 | 8篇 |
预防医学 | 964篇 |
眼科学 | 245篇 |
药学 | 606篇 |
中国医学 | 23篇 |
肿瘤学 | 525篇 |
出版年
2021年 | 134篇 |
2019年 | 128篇 |
2018年 | 170篇 |
2017年 | 106篇 |
2016年 | 97篇 |
2015年 | 127篇 |
2014年 | 175篇 |
2013年 | 259篇 |
2012年 | 372篇 |
2011年 | 389篇 |
2010年 | 227篇 |
2009年 | 202篇 |
2008年 | 321篇 |
2007年 | 394篇 |
2006年 | 392篇 |
2005年 | 376篇 |
2004年 | 344篇 |
2003年 | 316篇 |
2002年 | 315篇 |
2001年 | 262篇 |
2000年 | 295篇 |
1999年 | 249篇 |
1998年 | 121篇 |
1997年 | 122篇 |
1996年 | 137篇 |
1995年 | 121篇 |
1994年 | 97篇 |
1993年 | 88篇 |
1992年 | 217篇 |
1991年 | 199篇 |
1990年 | 197篇 |
1989年 | 209篇 |
1988年 | 185篇 |
1987年 | 181篇 |
1986年 | 154篇 |
1985年 | 160篇 |
1984年 | 111篇 |
1983年 | 104篇 |
1982年 | 72篇 |
1981年 | 88篇 |
1980年 | 87篇 |
1979年 | 128篇 |
1978年 | 79篇 |
1977年 | 77篇 |
1975年 | 77篇 |
1974年 | 81篇 |
1973年 | 98篇 |
1972年 | 83篇 |
1971年 | 81篇 |
1970年 | 76篇 |
排序方式: 共有9735条查询结果,搜索用时 203 毫秒
11.
Ramona A. Cole Anita Bansal Debra M. Moriarity William A. Haber William N. Setzer 《Journal of natural medicines》2007,61(4):414-417
The leaf essential oil of Eugenia zuchowskiae from Monteverde, Costa Rica, has been obtained by hydrodistillation and analyzed by GC–MS. The principal constituents of
E. zuchowskiae leaf oil were α-pinene (28.3%), β-caryophyllene (13.2%), α-humulene (13.1%), and α-copaene (8.1%). The leaf essential oil
of E. zuchowskiae showed pronounced in-vitro cytotoxic activity against MCF-7, MDA-MB-468, and UACC-257 human tumor cell lines. The major components
showed cytotoxic activities comparable to doxorubicin (LC50 14–70 μg/ml). 相似文献
12.
A LONG PERSPECTIVE ON CHILDHOOD MULTIPLE SCLEROSIS 总被引:5,自引:1,他引:4
13.
14.
15.
D K Williams D R Carlton S H Green K Pearman T R Cole 《Journal of medical genetics》1997,34(10):842-845
We report a child of 3 years 9 months with the Marshall-Smith syndrome (MSS), characterised by the typical facial features, developmental delay, and advanced bone age. After the diagnosis was made at 5 months of age, careful observation for respiratory complications and failure to thrive was initiated. By 3 1/2 years of age, although our patient had no life threatening respiratory complications, investigation showed significant upper airway obstruction, which has been successfully treated. Aggressive treatment for failure to thrive has also allowed her to maintain a weight on the 50th centile. The purpose of this report is to suggest that early diagnosis and aggressive management may improve the ultimate prognosis with respect to the respiratory and feeding difficulties seen in this rare syndrome. 相似文献
16.
Manoussos M. Konstadoulakis MD Michael Vezeridis MD Emi Hatziyianni MD Constantine P. Karakousis MD PhD Bernard Cole PhD Kirby I. Bland MD Harold J. Wanebo MD 《Annals of surgical oncology》1998,5(3):253-260
Background: Oncogenes and other molecular tumor markers that predict tumor aggressiveness may allow individualization and optimization of surgical therapy of intermediate-thickness malignant melanoma. We examined the expression of selected markers, including the HLA-DR antigen, the heat shock protein-70 (HSP-70), and the c-myc oncogene in primary melanoma and regional nodes and related these findings to metastatic potential and survival.
Methods: Forty patients with primary melanoma (1.5–4.0 mm) were studied, all of whom had prophylactic lymph node dissection and were followed for 18 months to 7 years. The primary tissue and nodes were examined using immunohistochemical techniques for the presence of HLA-DR antigen and HSP-70 protein and the expression of the c-myc oncogene.
Results: Of 40 patients, there were 23 with lesions 1 to 2.9 mm thick and 17 with lesions 3 to 4 mm thick. Nodal metastases were present in 25 of the 40 patients who had elective node dissection. HLA-DR antibody stained the primary tumor in 10 patients (25%), but there was no correlation with survival in this group. HLA-DR antibody stained the stroma and cellular infiltrates surrounding the primary tumor in 28 of 40 patients; in this group there was a correlation of HLA-DR staining of the peritumoral stroma with improved survival overall. HLA-DR staining of the peritumoral stroma also influenced survival when patients were stratified by tumor thickness groups 1 to 2.9 mm and 3 to 4 mm and presence of nodal metastases. HSP-70 was demonstrated in the primary tumor in 25% of patients, who were also shown to have significantly improved survival when compared with those whose primary tumor did not stain with HSP-70. C-myc was expressed in the primary tumor in 25%, but showed no correlation with survival. None of these proteins correlated with or predicted the presence of nodal metastases.
Conclusion: We conclude that the use of specific molecular-oncogene markers in intermediate-thickness primary melanoma may identify patients at high risk for conventional treatment failure and reduced survival who may profit from more aggressive surgery, adjuvant therapy, or both.Presented at the 48th Annual Cancer Symposium of The Society of Surgical Oncology, Boston, Massachusetts, March 23–26, 1995. 相似文献
17.
Biosynthesis of the antibiotic actinorhodin. Analysis of blocked mutants of Streptomyces coelicolor 总被引:6,自引:0,他引:6
From two types of class V act mutants of Streptomyces coelicolor two monomeric precursors of actinorhodin have been isolated and their structures determined. One is the known antibiotic kalafungin and the other a new compound. Their relationship to actinorhodin biosynthesis is discussed. 相似文献
18.
Interleukin 1 mediated acceleration of type II collagen-induced arthritis: effects of anti-inflammatory or anti-arthritic drugs 总被引:1,自引:0,他引:1
We previously demonstrated that treatments with rIL-1 beta accelerated the onset and progression of CIA in mice. In the present study, it was observed that IL-1 also enhanced the development of CIA in rats. Like the mouse model, maximal incidence (80-100%) of arthritis occurred within 7 days after the first treatment with IL-1 in rats. Thus, the acceleration of CIA by IL-1 (IL-1 CIA) may be an improved model for the rapid screening of anti-inflammatory and/or anti-arthritic drugs. As a first step to determining the utility of the IL-1 CIA model as a drug screen, we examined the ability of various known anti-inflammatory and anti-arthritic drugs to modify the IL-1 mediated enhancement of CIA in both rats and mice. The results of these studies showed that when analyzed in the IL-1 CIA model, rats and mice exhibited differences in their responses to several of these drugs. For example, dexamethasone, cyclophosphamide, azathioprine, various non-steroidal anti-inflammatory drugs (NSAIDs) as well as methotrexate were found active in the IL-1 CIA of rats. By contrast, the NSAIDs were found to be less effective in suppressing the IL-1 accelerated disease in mice. In both rats and mice, cyclosporine A and several disease modifying anti-arthritic drugs failed to the prevent the development of CIA that was potentiated by IL-1. Thus, in the IL-1 CIA model NSAIDs appeared to be less active in mice than rats. In conclusion, because of the shorter latent period required for the development of arthritis in the IL-1 treated animals, the IL-1 accelerated CIA model in both mice and rats may be useful for screening anti-inflammatory or anti-arthritic compounds. 相似文献
19.
20.