全文获取类型
收费全文 | 4575篇 |
免费 | 209篇 |
国内免费 | 31篇 |
专业分类
耳鼻咽喉 | 93篇 |
儿科学 | 60篇 |
妇产科学 | 44篇 |
基础医学 | 558篇 |
口腔科学 | 77篇 |
临床医学 | 266篇 |
内科学 | 1334篇 |
皮肤病学 | 74篇 |
神经病学 | 374篇 |
特种医学 | 122篇 |
外科学 | 685篇 |
综合类 | 26篇 |
一般理论 | 1篇 |
预防医学 | 186篇 |
眼科学 | 162篇 |
药学 | 266篇 |
中国医学 | 15篇 |
肿瘤学 | 472篇 |
出版年
2023年 | 28篇 |
2022年 | 52篇 |
2021年 | 98篇 |
2020年 | 42篇 |
2019年 | 72篇 |
2018年 | 89篇 |
2017年 | 82篇 |
2016年 | 84篇 |
2015年 | 69篇 |
2014年 | 125篇 |
2013年 | 159篇 |
2012年 | 199篇 |
2011年 | 210篇 |
2010年 | 149篇 |
2009年 | 104篇 |
2008年 | 262篇 |
2007年 | 230篇 |
2006年 | 194篇 |
2005年 | 217篇 |
2004年 | 185篇 |
2003年 | 214篇 |
2002年 | 189篇 |
2001年 | 164篇 |
2000年 | 175篇 |
1999年 | 152篇 |
1998年 | 58篇 |
1997年 | 33篇 |
1996年 | 31篇 |
1995年 | 30篇 |
1994年 | 25篇 |
1992年 | 97篇 |
1991年 | 76篇 |
1990年 | 86篇 |
1989年 | 78篇 |
1988年 | 66篇 |
1987年 | 52篇 |
1986年 | 61篇 |
1985年 | 46篇 |
1984年 | 45篇 |
1983年 | 34篇 |
1979年 | 29篇 |
1975年 | 23篇 |
1974年 | 22篇 |
1973年 | 34篇 |
1971年 | 24篇 |
1970年 | 25篇 |
1969年 | 35篇 |
1968年 | 35篇 |
1967年 | 30篇 |
1966年 | 25篇 |
排序方式: 共有4815条查询结果,搜索用时 0 毫秒
111.
112.
Hidenori Arai Yasuyoshi Ouchi Masayuki Yokode Hideki Ito Hiroshi Uematsu Fumio Eto Shinichi Oshima Kikuko Ota Yasushi Saito Hidetada Sasaki Kazuo Tsubota Hidenao Fukuyama Yoshihito Honda Akihisa Iguchi Kenji Toba Takayuki Hosoi Toru Kita for the Members of the Subcommittee for Aging 《Geriatrics & Gerontology International》2012,12(1):16-22
113.
The concept of mimicking structural colour in nature as an alternative to traditional textile coloration techniques would reduce dependency on dyes, pigments and vast quantities of water in the textile supply chain. Structural colours originate from the physical interaction of light with nanoscale structures. This is exhibited in the bodies and wings of certain species of butterfly, beetles and plants. The angular optical effects of the Chrysina gloriosa beetle result from the periodicity due to the cholesteric liquid crystal (CLC) structure adopted by the cells in their exoskeleton. The optical properties of CLCs makes promising applications for optical sensors and anti-counterfeit materials. Application using inkjet printing technology enables designs to be tuned to meet product requirements, and with a hydrophobic treatment challenges associated with a rough surface such as textiles are overcome. Here we report inkjet printing CLC solutions onto hydrophobic pre-treated textiles. CIE L*a*b* values demonstrate the resultant colourful films display a greater degree of colour compared to those on untreated textiles.The concept of mimicking structural colour in nature as an alternative to traditional textile coloration techniques would reduce dependency on dyes, pigments and vast quantities of water in the textile supply chain. 相似文献
114.
Takenaka Akinori Inui Yoshitaka Kimura Yuichi Miyake Chikara Fujiyama Yoichi Yamada Takashi Hashizume Nobuya Kato Takashi Ito Kengo Toyama Hiroshi 《Annals of nuclear medicine》2019,33(8):586-593
Annals of Nuclear Medicine - The objective of the present study was to develop a fully automated blood sampling system for kinetic analysis in mice positron emission tomography (PET) studies.... 相似文献
115.
116.
117.
Naohiro Oshima Tomofumi Shimizu Yuji Narukawa Noriyasu Hada Fumiyuki Kiuchi 《Journal of natural medicines》2018,72(3):706-714
Orengedokuto is a Kampo formula that has been used for removing “heat” and “poison” to treat inflammation, hypertension, gastrointestinal disorders, and liver and cerebrovascular diseases. We report here our analysis of the anti-inflammatory effect of the component crude drugs of orengedokuto and their constituents using the inhibition of nitric oxide (NO) production in the murine macrophage-like cell line J774.1. An initial comparison of NO production inhibitory activities of the extracts of the component crude drugs and their combinations revealed that the activity could be attributed to Phellodendron Bark and Coptis Rhizome. Berberine (1), the major constituent of these crude drugs, showed potent activity (IC50 4.73?±?1.46 μM). Quantitative analysis of 1 in the extracts of all combinations of component crude drugs revealed that the amount of 1 in each extract of the combination of Scutellaria Root with either Phellodendron Bark and/or Coptis Rhizome was lower than that in the corresponding mixtures of the extracts of the individual crude drugs and that 1 was present in the precipitates formed during the decoction process. To the contrary, the differences in the amounts of 1 were smaller in the extracts containing Gardenia Fruit. These results indicated that the constituents of Scutellaria Root precipitated with 1 and that the constituents of Gardenia Fruit dissolved the precipitates. To identify the constituents affecting the solubility of 1, we fractionated the hot-water extracts of Scutellaria Root based on solubility tests of 1 to give baicalin (2), wogonin (3) and oroxyloside (4), which formed precipitates with 1. 相似文献
118.
Shimizu Tomofumi Shibuya Nobuhiko Narukawa Yuji Oshima Naohiro Hada Noriyasu Kiuchi Fumiyuki 《Journal of natural medicines》2018,72(1):181-191
Journal of Natural Medicines - Scutellaria root, the root of Scutellaria baicalensis Georgi, is a crude drug used for inflammatory diseases. In our previous report, the combination of flavonoids... 相似文献
119.
do Prado RF Lima CF Pontes HA Almeida JD Cabral LA Carvalho YR 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(5):e40-e44
The aim of this study was to report an unusual case of mucoepidermoid carcinoma (MEC) in a 39-year-old woman. The tumor showed a prominent population of clear and intermediate basal cells. Clear cells rarely predominate over other cell types. Such cases are called clear cell variant of MEC. The case also revealed a variable amount of calcified material in the tumor mass. Calcifications are rare in clear cell MEC. These structures were periodic acid-Schiff positive and diastase resistant, excluding glycogen origin. Immunohistochemistry was performed, and the epidermoid component was positive for cytokeratin (CK)7, CK13, CK14, and CK19. The mucous and clear cells presented mild staining for CK7. Cytokeratins 7, 13, and 19 stained luminal cells, and intermediate cells exhibited positivity for CK7, CK14, and vimentin. The origin of the calcifications is speculated to be the result of dystrophic calcification of the amorphous eosinophilic material secreted by intermediate basal cells. 相似文献
120.
Etidronate inhibits human osteoblast apoptosis by inhibition of pro-apoptotic factor(s) produced by activated T cells 总被引:4,自引:0,他引:4
Abe Y Kawakami A Nakashima T Ejima E Fujiyama K Kiriyama T Ide A Sera N Usa T Tominaga T Ashizawa K Yokoyama N Eguchi K 《The Journal of laboratory and clinical medicine》2000,136(5):344-354
Humoral factors produced by activated T cells are thought to be important in the development of bone loss in patients with rheumatoid arthritis (RA). We investigated the inhibitory effect of etidronate disodium (EHDP) on apoptosis of human osteoblasts induced by supernatants from in vitro activated T cell cultures. Human osteoblastic cell line MG63 cells and human primary osteoblast-like cells were used in the present study as human osteoblasts. T cells were incubated with interleukin-2 and further activated with 1 2-o-tetradecanoyl-phorbol 13-acetate and ionomycin, either in the presence or absence of EHDP. After we carried out the cultivation, we examined the cytotoxicity of cultured T cell supernatants toward MG63 cells and human primary osteoblast-like cells. Supernatants from activated but not resting T cell cultures efficiently induced apoptosis of MG63 cells and primary osteoblast-like cells. Supernatants from activated T cell cultures, incubated with EHDP, exhibited significantly less cytotoxicity than did supernatants incubated in the absence of EHDP. In contrast, the cytotoxicity of activated T cell culture supernatants was not affected by direct treatment of human osteoblasts with EHDP. The concentration of soluble Fas ligand in activated T cell culture supernatants was actually increased by EHDP. However, EHDP did not influence soluble Fas and tumor necrosis factor-alpha concentrations in the supernatant. Furthermore, treatment of human osteoblasts with EHDP did not alter their expression of Bcl-2/Bcl-xL or their sensitivity to anti-Fas immunoglobulin M-induced apoptosis. Our results suggest that EHDP inhibits the production of soluble factor that induces apoptosis of human osteoblasts and thus exhibits a protective action toward human osteoblast apoptosis induced by activated T cell culture supernatants. Although the exact EHDP-regulated molecule that induces apoptosis of human osteoblasts is unknown at present, our study may explain part of the therapeutic action of bisphosphonates in RA complicated by bone loss. 相似文献