全文获取类型
收费全文 | 5183篇 |
免费 | 368篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 44篇 |
儿科学 | 101篇 |
妇产科学 | 91篇 |
基础医学 | 830篇 |
口腔科学 | 103篇 |
临床医学 | 474篇 |
内科学 | 1209篇 |
皮肤病学 | 201篇 |
神经病学 | 646篇 |
特种医学 | 218篇 |
外科学 | 441篇 |
综合类 | 26篇 |
一般理论 | 6篇 |
预防医学 | 367篇 |
眼科学 | 61篇 |
药学 | 378篇 |
中国医学 | 8篇 |
肿瘤学 | 375篇 |
出版年
2023年 | 57篇 |
2022年 | 95篇 |
2021年 | 197篇 |
2020年 | 143篇 |
2019年 | 183篇 |
2018年 | 206篇 |
2017年 | 167篇 |
2016年 | 183篇 |
2015年 | 201篇 |
2014年 | 218篇 |
2013年 | 291篇 |
2012年 | 432篇 |
2011年 | 436篇 |
2010年 | 268篇 |
2009年 | 227篇 |
2008年 | 350篇 |
2007年 | 290篇 |
2006年 | 290篇 |
2005年 | 242篇 |
2004年 | 190篇 |
2003年 | 194篇 |
2002年 | 140篇 |
2001年 | 39篇 |
2000年 | 39篇 |
1999年 | 44篇 |
1998年 | 51篇 |
1997年 | 37篇 |
1996年 | 30篇 |
1995年 | 23篇 |
1994年 | 16篇 |
1993年 | 16篇 |
1992年 | 18篇 |
1991年 | 15篇 |
1990年 | 10篇 |
1989年 | 15篇 |
1988年 | 17篇 |
1982年 | 10篇 |
1980年 | 15篇 |
1979年 | 9篇 |
1978年 | 8篇 |
1976年 | 8篇 |
1975年 | 8篇 |
1974年 | 15篇 |
1973年 | 11篇 |
1972年 | 8篇 |
1971年 | 11篇 |
1970年 | 12篇 |
1968年 | 10篇 |
1967年 | 9篇 |
1966年 | 8篇 |
排序方式: 共有5579条查询结果,搜索用时 46 毫秒
51.
Human cornea construct HCC-an alternative for in vitro permeation studies? A comparison with human donor corneas. 总被引:1,自引:0,他引:1
Stephan Reichl Stefanie D?hring Jürgen Bednarz Christel C Müller-Goymann 《European journal of pharmaceutics and biopharmaceutics》2005,60(2):305-308
Transcorneal in vitro permeation studies of ophthalmic drugs are normally performed with either excised animal corneas or latterly corneal cell culture models. A good correlation between these models and excised animal corneas regarding permeation behaviour of drugs has already been shown. However, comparisons between corneal in vitro models containing human cells and excised human corneas do not exist yet. Therefore in the present study the transcorneal permeation of six different model drugs (pilocarpine hydrochloride, befunolol hydrochloride, hydrocortisone, diclofenac sodium, clindamycin hydrochloride and timolol maleate) across our previously described three-dimensional organotypic human cornea construct (HCC) was tested using Franz diffusion cells and compared with permeation data obtained from human donor corneas. The HCC showed a similar permeation behaviour compared with human donor cornea for all substances. The permeabilities (permeation coefficients P) of the human cornea equivalent versus the human donor cornea were the same in the case of diclofenac, clindamycin, timolol, but marginally decreased for hydrocortisone and slightly increased for pilocarpine and befunolol. These small differences of permeation coefficients were expressed as factors and only varied from 0.8 to 1.4. The results indicate that the HCC may be an alternative for in vitro permeation studies and appropriate for predicting drug absorption into the human eye. 相似文献
52.
53.
Johannes Hohenberger Anton Friesen Stefanie Wieck Klaus Kümmerer 《Sustainable Chemistry and Pharmacy》2022
The field of chemical rodent control has seen no major developments in the last decades, even though anticoagulant rodenticides (AR), the mainly used substances to manage mice and rats, are known environmental pollutants and candidates for substitution under the European Biocidal Products Regulation 528/2012. Moreover, recent political developments in Europe and the USA demand more safety and sustainability in the management of chemicals, reinforcing the need for environmentally friendly substances. In this concept study, we present a step-by-step approach to improve the environmental properties of rodenticides. Repurposing of existing pharmaceuticals, the use of enantiomerically pure rodenticides, or the improvement of the formulation by microencapsulation can help to alleviate environmental problems caused by AR in the short term. Modification of the chemical structures or the development of prodrugs as medium-term strategies can further improve environmental properties of existing compounds. Ultimately, the development of new substances from scratch enables the utilisation of so far ignored modes of actions and the application of modern safe and sustainable-by-design principles to improve target specificity and reduce the negative impact on non-target organisms and the environment. Overall, our concept study illustrates the great potential for improvement in the field of chemical rodent control when applying available techniques of green and sustainable chemistry to known or potential rodenticides. Most promising in the medium term is microencapsulation that would allow for the use of acutely acting substances as it could circumvent bait shyness. On a longer timescale the de novo design of new rodenticides, which is the only method that can combine a high target specificity with good environmental properties, is the most promising approach. 相似文献
54.
55.
Stefanie Enriquez‐Geppert Tom Eichele Karsten Specht Harald Kugel Christo Pantev Ren J. Huster 《Human brain mapping》2013,34(7):1501-1514
Conflict monitoring and motor inhibition are engaged in the performance of complex tasks. The midcingulate cortex (MCC) has been suggested to detect conflicts, whereas the right inferior frontal cortex (IFC) seems to be of relevance for the inhibition process. The current experiment investigates the neural underpinnings of their interplay via a modified flanker paradigm. Conflict was manipulated by the congruency of flanking stimuli relative to a target (congruent vs. incongruent) and motor inhibition by a within‐trial response change of the initiated response (keep response vs. stop‐change). We used event‐related functional magnetic resonance imaging, decomposition with high model order ICA, and single trial analysis to derive a functional parcellation of the whole‐brain data. Results demonstrate the segmentation of the MCC into anterior and posterior subregions, and of the IFC into the pars opercularis, pars triangularis, and pars orbitalis. The pars opercularis and pars triangularis of the right IFC constituted the foundation of inhibition‐related networks. With high conflict on incongruent trials, activity in the posterior MCC network, as well as in one right IFC network was observed. Stop‐change trials modulated both the MCC as well as networks covering extended parts of the IFC. Whereas conflict processing and inhibition most often are studied separately, this study provides a synopsis of functionally coupled brain regions acting in concert to enable an optimal performance in situations involving interference and inhibition. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
56.
57.
58.
Miroslava Herbstová Stefanie Tietz Christopher Kinzel Maria V. Turkina Helmut Kirchhoff 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(49):20130-20135
Unavoidable side reactions of photosynthetic energy conversion can damage the water-splitting photosystem II (PSII) holocomplex embedded in the thylakoid membrane system inside chloroplasts. Plant survival is crucially dependent on an efficient molecular repair of damaged PSII realized by a multistep repair cycle. The PSII repair cycle requires a brisk lateral protein traffic between stacked grana thylakoids and unstacked stroma lamellae that is challenged by the tight stacking and low protein mobility in grana. We demonstrated that high light stress induced two main structural changes that work synergistically to improve the accessibility between damaged PSII in grana and its repair machinery in stroma lamellae: lateral shrinkage of grana diameter and increased protein mobility in grana thylakoids. It follows that high light stress triggers an architectural switch of the thylakoid network that is advantageous for swift protein repair. Studies of the thylakoid kinase mutant stn8 and the double mutant stn7/8 demonstrate the central role of protein phosphorylation for the structural alterations. These findings are based on the elaboration of mathematical tools for analyzing confocal laser-scanning microscopic images to study changes in the sophisticated thylakoid architecture in intact protoplasts. 相似文献
59.
Coordes Stefanie Louise Jost-Brinkmann Paul-Georg Präger Thomas Michael Bartzela Theodosia Visel Dominik Jäcker Theresa Müller-Hartwich Ralf 《Journal of orofacial orthopedics》2018,79(1):49-56
Journal of Orofacial Orthopedics / Fortschritte der Kieferorthopädie - Aim of the study was to compare how six different sealants resisted thermal, mechanical, and chemical loading in vitro.... 相似文献
60.
Oral health‐related quality of life changes after placement of immediately loaded single implants in healed alveolar ridges or extraction sockets: a 5‐year prospective follow‐up study
下载免费PDF全文
![点击此处可从《Clinical oral implants research》网站下载免费的PDF全文](/ch/ext_images/free.gif)