全文获取类型
收费全文 | 110011篇 |
免费 | 42389篇 |
国内免费 | 432篇 |
专业分类
耳鼻咽喉 | 2059篇 |
儿科学 | 4616篇 |
妇产科学 | 991篇 |
基础医学 | 20986篇 |
口腔科学 | 5818篇 |
临床医学 | 15294篇 |
内科学 | 29008篇 |
皮肤病学 | 8521篇 |
神经病学 | 15556篇 |
特种医学 | 4353篇 |
外国民族医学 | 2篇 |
外科学 | 17648篇 |
综合类 | 296篇 |
现状与发展 | 3篇 |
一般理论 | 29篇 |
预防医学 | 5683篇 |
眼科学 | 1967篇 |
药学 | 8755篇 |
1篇 | |
中国医学 | 1498篇 |
肿瘤学 | 9748篇 |
出版年
2023年 | 300篇 |
2022年 | 1026篇 |
2021年 | 2625篇 |
2020年 | 5615篇 |
2019年 | 11518篇 |
2018年 | 10949篇 |
2017年 | 12031篇 |
2016年 | 13109篇 |
2015年 | 13402篇 |
2014年 | 13494篇 |
2013年 | 14317篇 |
2012年 | 7399篇 |
2011年 | 7041篇 |
2010年 | 10520篇 |
2009年 | 6616篇 |
2008年 | 4033篇 |
2007年 | 2660篇 |
2006年 | 2499篇 |
2005年 | 2139篇 |
2004年 | 1879篇 |
2003年 | 1763篇 |
2002年 | 1650篇 |
2001年 | 1317篇 |
2000年 | 1213篇 |
1999年 | 691篇 |
1998年 | 243篇 |
1997年 | 189篇 |
1996年 | 143篇 |
1995年 | 116篇 |
1994年 | 108篇 |
1993年 | 101篇 |
1992年 | 157篇 |
1991年 | 178篇 |
1990年 | 141篇 |
1989年 | 130篇 |
1988年 | 123篇 |
1987年 | 105篇 |
1986年 | 107篇 |
1985年 | 90篇 |
1984年 | 60篇 |
1983年 | 60篇 |
1982年 | 47篇 |
1979年 | 70篇 |
1978年 | 49篇 |
1975年 | 60篇 |
1974年 | 39篇 |
1972年 | 45篇 |
1971年 | 60篇 |
1970年 | 46篇 |
1968年 | 41篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
Critical size defect in the canine mandible. 总被引:3,自引:0,他引:3
Jin-Young Huh Byung-Ho Choi Byung-Young Kim Seoung-Ho Lee Shi-Jiang Zhu Jae-Hyung Jung 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2005,100(3):296-301
OBJECTIVE: The purpose of this study was to determine the minimum size defect in a canine mandible that would not spontaneously heal during the dog's natural life (the critical size defect). STUDY DESIGN: Sixteen adult female mongrel dogs underwent continuity resection on both sides of the mandible to create bilateral defects. In 8 dogs, mandibular defects ranging from 5 to 20 mm were created with periosteal resection. In the other 8 dogs, mandibular defects ranging from 30 to 60 mm were created preserving the periosteum. The dogs were then killed at 6 months and the defects examined using radiographs and histologic analysis. RESULTS: When the periosteum was removed, mandibular defects greater than 15 mm failed to heal across the entire defect. However, when the periosteum was preserved, mandibular defects needed to be greater than 50 mm in order to fail to heal. CONCLUSION: The critical size defect in a canine mandible model is 15 mm when the periosteum is removed and 50 mm when the periosteum is preserved. 相似文献
23.
Dry skin (xerosis) is a common dermatosis affecting people of varying skin types and ages and various areas of the body. It is associated with both skin thickening and skin thinning and is triggered by both exogenous (e.g. climate, environment, lifestyle) and endogenous (e.g. medication, hormone fluctuations, organ diseases) factors. Skin requires a water content of 10–15% to remain supple and intact. This water is either ‘static’ (i.e. bound) or ‘dynamic’. The predominance of hydrophobic substances in intercellular constituents is a means of regulating the humidity of the skin. Emollients, highly effective treatment adjuncts in the management of all dry skin disorders, help to restore damaged intercorneocyte lipid structures and increase the water content of the skin, helping to reduce scaling and improving its barrier function. 相似文献
24.
25.
26.
27.
28.
Seunghan Ha Minhee Lee Onseok Lee Gunwoo Lee Jeayoung Kim Jongsub Moon Mingi Kim Chilhwan Oh 《Skin research and technology》2009,15(2):200-213
Background/aims: The objective and quantitative assessment of the skin is important in medical and cosmeceutical research. Assessment of color is an important element for analyzing the surface of the skin, which is usually determined subjectively by a doctor or using color analysis devices. These devices, however, cannot provide correct color information because color is construed from the mean value of the observation region, and analysis of color distribution is impossible. The purpose of this paper is to develop an objective analysis method to permit skin color measurement of each pixel unit of an image and analyze the distribution of skin surface color. Methods: The Skin Color Distribution Analyzer (SCDA) is an analysis method newly developed at the Research Institute for Skin Image at Korea University. The SCDA system presented in this paper performed a novel form of quantitative and objective analysis of skin color distribution using each pixel color model parameter found in image wavelength information. In this paper, distribution analysis was conducted on normal skin and skin lesions and skin affected by artificially induced irritant contact dermatitis and pigmented nevous. The method selected a grade using a color model parameter. Twenty healthy Korean males participated in this study. A comparative study of the eight anatomical areas was performed, including the exposure and non‐exposure parts and the medial aspect and the lateral aspect of the forearm. A reliability test for the SCDA system was also conducted with a spectrometer (SPEC) using the color analysis method. Results: Each skin lesion was precisely segmented by grade and each parameter hada different statistical significance for results of analysis of distribution in pigmented nevous and the artificially induced irritant contact dermatitis. Parameters L*, b*, a*, and EI showed salient traits. Showed resemble measured result in the SCDA system and the SPEC of normal skin. The exposed site, in comparison with the non‐exposed site, showed a notable difference in the L* parameter and a significant statistical difference in the x and z parameters, except b*. The comparison of the medial and lateral aspects of the forearm showed a notable difference in the L* parameter and a significant statistical difference in the parameters except y and b*. In the reliability test result using the SCDA system and the SPEC, the SCDA system was highly reliabile in terms of the CV value in all color model parameters. Conclusions: The color distribution analysis method using the SCDA system has revealed an aspect that the existent method of medical research has not shown, and is considered to be more reliable than other methods. This method can provide better study findings because it can be applied to other fields in addition to the medical science field and the ripple effect is thought to be bigger in other science field too. 相似文献
29.
Jing‐Ping Zhang Limin Zheng Jiang‐Hai Wang Karl‐Eric Magnusson Xin Liu 《Phytotherapy research : PTR》2009,23(6):844-850
Ganoderma sinensis has been used widely in Oriental countries for the prevention and treatment of various diseases including cancer. Previous studies have shown that the lipid extract from Ganoderma exhibits direct cytotoxicity against tumor cells. Here, it is reported that the lipid extract from germinating G. sinensis spores, at lower concentrations that have no direct tumoricidal activity, induce potent antitumor immune responses in human monocytes/macrophages. Upon stimulation with the lipid extract, monocytes/macrophages exhibited markedly increased production of proinflammatory cytokines and surface expression of costimulatory molecules. Conditioned medium from stimulated cells effectively suppressed the growth of tumor cells. Apparently, the lipid extract triggered macrophage activation via a mechanism different from that associated with LPS. Moreover, it was observed that the lipid extract could partially re‐establish the antitumor activity of the immunosuppressive tumor‐associated macrophages. These results indicated that in addition to its direct tumoricidal activity, the lipid extract from G. sinensis spores could exert antitumor activity by stimulating the activation of human monocytes/macrophages. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
30.