全文获取类型
收费全文 | 1834篇 |
免费 | 128篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 101篇 |
妇产科学 | 35篇 |
基础医学 | 180篇 |
口腔科学 | 84篇 |
临床医学 | 224篇 |
内科学 | 408篇 |
皮肤病学 | 61篇 |
神经病学 | 68篇 |
特种医学 | 103篇 |
外国民族医学 | 1篇 |
外科学 | 338篇 |
综合类 | 45篇 |
预防医学 | 117篇 |
眼科学 | 23篇 |
药学 | 86篇 |
中国医学 | 3篇 |
肿瘤学 | 65篇 |
出版年
2022年 | 39篇 |
2021年 | 58篇 |
2020年 | 28篇 |
2019年 | 43篇 |
2018年 | 34篇 |
2017年 | 30篇 |
2016年 | 28篇 |
2015年 | 41篇 |
2014年 | 54篇 |
2013年 | 61篇 |
2012年 | 66篇 |
2011年 | 82篇 |
2010年 | 76篇 |
2009年 | 57篇 |
2008年 | 65篇 |
2007年 | 69篇 |
2006年 | 67篇 |
2005年 | 58篇 |
2004年 | 58篇 |
2003年 | 52篇 |
2002年 | 48篇 |
2001年 | 32篇 |
2000年 | 33篇 |
1999年 | 41篇 |
1998年 | 32篇 |
1997年 | 22篇 |
1996年 | 36篇 |
1995年 | 24篇 |
1994年 | 35篇 |
1993年 | 32篇 |
1992年 | 29篇 |
1991年 | 27篇 |
1990年 | 33篇 |
1989年 | 29篇 |
1988年 | 33篇 |
1987年 | 27篇 |
1986年 | 25篇 |
1985年 | 24篇 |
1984年 | 18篇 |
1983年 | 19篇 |
1982年 | 14篇 |
1981年 | 15篇 |
1980年 | 16篇 |
1979年 | 29篇 |
1978年 | 17篇 |
1977年 | 14篇 |
1976年 | 15篇 |
1975年 | 14篇 |
1974年 | 14篇 |
1969年 | 15篇 |
排序方式: 共有1965条查询结果,搜索用时 15 毫秒
41.
Khadija EL. Mouaden D.S. Chauhan M.A. Quraishi Lahcen Bazzi 《Sustainable Chemistry and Pharmacy》2020
A facile single-step synthesis was performed to cross-link chitosan with thiocarbohydrazide to yield thiocarbohydrazide-chitosan (TC-Cht) which was for the first time evaluated as an inhibitor for corrosion of stainless steel in 3.5% NaCl solution. A comprehensive electrochemical analysis employing electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and cyclic voltammetry (CV) was undertaken and showed that the TC-Cht acts by adsorption on the steel surface and exhibits mixed type behavior with predominantly cathodic nature. The adsorption of TC-Cht molecules on the surface of stainless steel followed the Langmuir isotherm. The TC-Cht showed a high inhibition efficiency of >94% at 500 mg L?1 concentration. Surface investigation using SEM and EDX supported the inhibitor adsorption on the steel surface. 相似文献
42.
Pyae Hein Htun Arata Ebihara Keiichiro Maki Shunsuke Kimura Miki Nishijo Moe Sandar Kyaw Takashi Okiji 《Journal of endodontics》2021,47(1):94-99
IntroductionThis study aimed to analyze torque/force generation and transportation in double-curved canals instrumented with 3 types of glide path files using optimum glide path (OGP) motion in comparison with continuous rotation.MethodsSixty simulated double-curved canals were prepared with #10/0.05 or #15/0.03 HyFlex EDM Glidepath files (Coltene/Whaledent, Altstätten, Switzerland) or a #13/0.04 prototype MANI Glidepath file (Tochigi, Japan) using OGP motion or continuous rotation (n = 10 each). Canals were sequentially prepared to 20 mm and 22 mm (full working length) using automated root canal instrumentation and a torque/force analyzing device. Transportation was calculated at 1–9 mm from the apex. Data were compared using 2-way analysis of variance followed by a post hoc simple main effect test with Bonferroni correction and a Kruskal-Wallis test (α = 5%).ResultsAll #10/0.05 instruments fractured. In the 22-mm preparation, the OGP motion resulted in lower clockwise torque and screw-in force than did continuous rotation (P < .05). In the 20-mm preparation, #15/0.03 instruments recorded a lower screw-in force for OGP motion than for continuous rotation (P < .05). Comparing the 2 preparation phases, OGP motion generated no significant differences; however, continuous rotation developed higher clockwise torque and screw-in force in the 22-mm preparation than in the 20-mm preparation (P < .05). There was no significant difference among the tested groups for transportation values.ConclusionsCompared with continuous rotation, OGP motion generated less screw-in force, lower clockwise torque, and similar transportation. The #15/0.03 HyFlex EDM instrument and the #13/0.04 prototype MANI instrument performed similarly well. 相似文献
43.
44.
45.
46.
Hideki Ogura Toru Atsumi Hidenori Bando Lavannya Sabharwal Moe Yamada Jing-Jing Jiang Akihiro Nakamura Yasunobu Arima Daisuke Kamimura Masaaki Murakami 《Archivum immunologiae et therapiae experimentalis》2014,62(1):41-45
Genome-wide analyses such as DNA microarray, RNA sequencing and RNA interference-based high-throughput screening are prevalent to decipher a biological process of interest, and provide a large quantity of data to be processed. An ultimate goal for researchers must be extrapolation of their data to human diseases. We have conducted functional genome-wide screenings to elucidate molecular mechanisms of the inflammation amplifier, a NFκB/STAT3-dependent machinery that potently drives recruitment of immune cells to promote inflammation. Using a public database of genome-wide association studies (GWAS), we recently reported the reverse-direction method by which our mass screening data were successfully linked to many human diseases. As an example, the epiregulin–epidermal growth factor receptor pathway was identified as a regulator of the inflammation amplifier, and associated with human diseases by GWAS. In fact, serum epiregulin levels were higher in patients with chronic inflammatory disorders. The reverse-direction method can be a useful tool to narrow mass data down to focus on human disease-related genes. 相似文献
47.
Soneela Ankam Mona Suryana Lesley Y. Chan Aung Aung Kywe Moe Benjamin K.K. Teo Jaslyn B.K. Law Michael P. Sheetz Hong Yee Low Evelyn K.F. Yim 《Acta biomaterialia》2013,9(1):4535-4545
Efficient derivation of neural cells from human embryonic stem cells (hESCs) remains an unmet need for the treatment of neurological disorders. The limiting factors for current methods include being labor-intensive, time-consuming and expensive. In this study, we hypothesize that the substrate topography, with optimal geometry and dimension, can modulate the neural fate of hESCs and enhance the efficiency of differentiation. A multi-architectural chip (MARC) containing fields of topographies varying in geometry and dimension was developed to facilitate high-throughput analysis of topography-induced neural differentiation in vitro. The hESCs were subjected to “direct differentiation”, in which small clumps of undifferentiated hESCs were cultured directly without going through the stage of embryoid body formation, on the MARC with N2 and B27 supplements for 7 days. The gene and protein expression analysis indicated that the anisotropic patterns like gratings promoted neuronal differentiation of hESCs while the isotropic patterns like pillars and wells promoted the glial differentiation of hESCs. This study showed that optimal combination of topography and biochemical cues could shorten the differentiation period and allowed derivation of neurons bearing longer neurites that were aligned along the grating axis. The MARC platform would enable high-throughput screening of topographical substrates that could maximize the efficiency of neuronal differentiation from pluripotent stem cells. 相似文献
48.
49.
Enomoto Hiroko Kato Kumiko Sugawara Asako Itabashi Moe Kondo Mineo 《Documenta ophthalmologica. Advances in ophthalmology》2021,142(3):353-360
Documenta Ophthalmologica - The study reports a case with metastatic cutaneous malignant melanoma that developed Vogt–Koyanagi–Harada-like uveitis during pembrolizumab treatment. The... 相似文献
50.