全文获取类型
收费全文 | 1028篇 |
免费 | 70篇 |
出版年
2023年 | 14篇 |
2022年 | 7篇 |
2021年 | 12篇 |
2020年 | 10篇 |
2019年 | 13篇 |
2018年 | 34篇 |
2017年 | 18篇 |
2016年 | 39篇 |
2015年 | 40篇 |
2014年 | 41篇 |
2013年 | 72篇 |
2012年 | 87篇 |
2011年 | 84篇 |
2010年 | 50篇 |
2009年 | 37篇 |
2008年 | 56篇 |
2007年 | 70篇 |
2006年 | 63篇 |
2005年 | 62篇 |
2004年 | 58篇 |
2003年 | 43篇 |
2002年 | 42篇 |
2001年 | 9篇 |
2000年 | 3篇 |
1999年 | 7篇 |
1998年 | 12篇 |
1997年 | 7篇 |
1996年 | 10篇 |
1995年 | 6篇 |
1994年 | 9篇 |
1993年 | 15篇 |
1992年 | 2篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1982年 | 7篇 |
1981年 | 3篇 |
1979年 | 3篇 |
1977年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1966年 | 2篇 |
1965年 | 2篇 |
1961年 | 1篇 |
1960年 | 2篇 |
1914年 | 1篇 |
排序方式: 共有1098条查询结果,搜索用时 187 毫秒
51.
52.
Irena Pastar Aron G. Nusbaum Joel Gil Shailee B. Patel Juan Chen Jose Valdes Olivera Stojadinovic Lisa R. Plano Marjana Tomic-Canic Stephen C. Davis 《PloS one》2013,8(2)
Understanding the pathology resulting from Staphylococcus aureus and Pseudomonas aeruginosa polymicrobial wound infections is of great importance due to their ubiquitous nature, increasing prevalence, growing resistance to antimicrobial agents, and ability to delay healing. Methicillin-resistant S. aureus USA300 is the leading cause of community-associated bacterial infections resulting in increased morbidity and mortality. We utilized a well-established porcine partial thickness wound healing model to study the synergistic effects of USA300 and P. aeruginosa on wound healing. Wound re-epithelialization was significantly delayed by mixed-species biofilms through suppression of keratinocyte growth factor 1. Pseudomonas showed an inhibitory effect on USA300 growth in vitro while both species co-existed in cutaneous wounds in vivo. Polymicrobial wound infection in the presence of P. aeruginosa resulted in induced expression of USA300 virulence factors Panton-Valentine leukocidin and α-hemolysin. These results provide evidence for the interaction of bacterial species within mixed-species biofilms in vivo and for the first time, the contribution of virulence factors to the severity of polymicrobial wound infections. 相似文献
53.
54.
55.
Aleksandra Kładna Paweł Berczyński Irena Kruk Teresa Piechowska Hassan Y. Aboul‐Enein 《Luminescence》2016,31(6):1201-1206
Isoflavones genistein and daidzein are nonsteroidal phytoestrogens occurring mainly in soybean foods. These phytoestrogens possess estrogenic properties and show a variety of health benefits as anti‐inflammatory agents. However, the mechanism of their action has not been identified in detail. The aim of this study is to characterize the antioxidant powers of genistein, daidzein and daidzein metabolite–equol through their activities to scavenge superoxide anion radical (O?2?), hydroxyl radical (HO?), 2,2–diphenyl–1‐picrylhydrazyl radical (DPPH?) and hydrogen peroxide (H2O2) using chemiluminescence and spectrophotometry techniques. Potassium superoxide in dimethyl sulphoxide (DMSO) and 18‐crown‐6 ether were used as a source of O?2?. Hydroxyl radicals were produced using the Fenton reaction. In free radical assays, genistein had the IC50 values (an amount of antioxidant concentration required to decrease the initial radical concentration by 50%) 0.391 ± 0.012 mM for O?2?, 0.621 ± 0.028 mM for HO? and 1.89 ± 0.16 mM for DPPH?. The IC50 values for daidzein for these free radicals were 1.924 ± 0.011 mM, 0.702 ± 0.012 mM and 2.81 ± 0.03 mM, respectively. Equol was the most active the free radical scavenger with IC50 = 0.451 ± 0.018 mM for HO? and IC50 = 1.36 ± 0.11 mM for DPPH?. All tested compounds exerted a significant effect on the H2O2: IC50 = 18.1 ± 1.1 μM for genistein, IC50 = 2.1 ± 0.5 μM for daidzein, and IC50 = 1.06 ± 0.2 μM for equol. These findings show that genistein, daidzein and equol are effective free radical scavengers and possess high antioxidant power in vitro. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
56.
57.
Norkus E Prusinskas K Vaskelis A Jaciauskiene J Stalnioniene I Macalady DL 《Carbohydrate research》2007,342(1):71-78
Saccharose, forming sufficiently stable complexes with copper(II) ions in alkaline solutions, was found to be a suitable ligand for copper(II) chelating in alkaline (pH>12) electroless copper deposition solutions. Reduction of copper(II)-saccharose complexes by hydrated formaldehyde was investigated and the copper deposits formed were characterized. The thickness of the compact copper coatings obtained under optimal operating conditions in 1h reaches ca. 2 microm at ambient temperature. The plating solutions were stable and no signs of Cu(II) reduction in the bulk solution were observed. Results were compared with those systems operating with other copper(II) ligands. 相似文献
58.
Susanna-Assunta Sansone Daniel Schober Helen J. Atherton Oliver Fiehn Helen Jenkins Philippe Rocca-Serra Denis V. Rubtsov Irena Spasic Larisa Soldatova Chris Taylor Andy Tseng Mark R. Viant 《Metabolomics : Official journal of the Metabolomic Society》2007,3(3):249-256
In this article we present the activities of the Ontology Working Group (OWG) under the Metabolomics Standards Initiative
(MSI) umbrella. Our endeavour aims to synergise the work of several communities, where independent activities are underway
to develop terminologies and databases for metabolomics investigations. We have joined forces to rise to the challenges associated
with interpreting and integrating experimental process and data across disparate sources (software and databases, private
and public). Our focus is to support the activities of the other MSI working groups by developing a common semantic framework
to enable metabolomics-user communities to consistently annotate the experimental process and to enable meaningful exchange
of datasets. Our work is accessible via a public webpage and a draft ontology has been posted under the Open Biological Ontology
umbrella. At the very outset, we have agreed to minimize duplications across omics domains through extensive liaisons with
other communities under the OBO Foundry. This is work in progress and we welcome new participants willing to volunteer their
time and expertise to this open effort.
See the MSI Ontology Working Group website for a complete list of members and contributors. Web URL: 相似文献
59.
60.
Max M. Tilzer Anna Hillbricht-Ilkowska Andrzej Kowalczewski Irena Spodniewska Joanna Turczyska 《International Review of Hydrobiology》1977,62(2):279-289
Photosynthetic rates as measured by the oxygen light and dark bottle method were highly correlated with estimates using the 14C technique. The high O2/14C ratios found are explained by algal respiration and extracellular release which are included in photosynthetic measurements by the oxygen technique, while the 14C method yields values close to net photosynthesis. Separation of net- and nannoplankton using a 50 μm plankton net for filtration was not comparable to distinctions made by microscopic examination. Separation of both by filtration caused a significant decrease in the photosynthetic activity of nannoplankton in 24-hour incubations, but had no detectable effect after 4 hours of exposure. “Bottle effects” in 24-hour measurements of photosynthesis were similar using both methods. Asymmetric photosynthetic time-curves as well as vertical phytoplankton migrations were the main reasons for errors in estimates of daily photosynthetic rates from part-day incubations which were extrapolated to the entire day. 相似文献