全文获取类型
收费全文 | 767篇 |
免费 | 11篇 |
国内免费 | 2篇 |
专业分类
780篇 |
出版年
2024年 | 15篇 |
2023年 | 14篇 |
2022年 | 41篇 |
2021年 | 44篇 |
2020年 | 17篇 |
2019年 | 26篇 |
2018年 | 36篇 |
2017年 | 31篇 |
2016年 | 35篇 |
2015年 | 29篇 |
2014年 | 41篇 |
2013年 | 50篇 |
2012年 | 50篇 |
2011年 | 61篇 |
2010年 | 25篇 |
2009年 | 21篇 |
2008年 | 25篇 |
2007年 | 23篇 |
2006年 | 19篇 |
2005年 | 19篇 |
2004年 | 11篇 |
2003年 | 19篇 |
2002年 | 21篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 13篇 |
1993年 | 10篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1967年 | 2篇 |
1964年 | 3篇 |
1960年 | 1篇 |
1959年 | 4篇 |
1954年 | 1篇 |
1936年 | 1篇 |
排序方式: 共有780条查询结果,搜索用时 15 毫秒
1.
Biosurfactant production by Pseudomonas aeruginosa EBN-8 mutant was studied in shake flasks on separate wastes from canola, soybean and corn oil refineries. Of the substrates
tested, canola oil refinery waste (COD=20 g l−1) supplemented with sodium nitrate (at COD/N=20) showed the best microbial growth (4.50 g l−1) and rhamnolipid production (8.50 g l−1), at 10 d of incubation with the specific growth rate of 0.316 h−1 and specific product yield of 0.597 g g−1 h. Its cell-free supernatant showed the critical micelle dilution (CMD) of 150 and surface tension (ST) of 28.5 mN m−1. 相似文献
2.
Jacqueline A. Sullivan Julie R. Dumont Sara Memar Miguel Skirzewski Jinxia Wan Maryam H. Mofrad Hassam Zafar Ansari Yulong Li Lyle Muller Vania F. Prado Marco A. M. Prado Lisa M. Saksida Timothy J. Bussey 《Genes, Brain & Behavior》2021,20(1):e12705
Many neurodegenerative and neuropsychiatric diseases and other brain disorders are accompanied by impairments in high-level cognitive functions including memory, attention, motivation, and decision-making. Despite several decades of extensive research, neuroscience is little closer to discovering new treatments. Key impediments include the absence of validated and robust cognitive assessment tools for facilitating translation from animal models to humans. In this review, we describe a state-of-the-art platform poised to overcome these impediments and improve the success of translational research, the Mouse Translational Research Accelerator Platform (MouseTRAP), which is centered on the touchscreen cognitive testing system for rodents. It integrates touchscreen-based tests of high-level cognitive assessment with state-of-the art neurotechnology to record and manipulate molecular and circuit level activity in vivo in animal models during human-relevant cognitive performance. The platform also is integrated with two Open Science platforms designed to facilitate knowledge and data-sharing practices within the rodent touchscreen community, touchscreencognition.org and mousebytes.ca. Touchscreencognition.org includes the Wall, showcasing touchscreen news and publications, the Forum, for community discussion, and Training, which includes courses, videos, SOPs, and symposia. To get started, interested researchers simply create user accounts. We describe the origins of the touchscreen testing system, the novel lines of research it has facilitated, and its increasingly widespread use in translational research, which is attributable in part to knowledge-sharing efforts over the past decade. We then identify the unique features of MouseTRAP that stand to potentially revolutionize translational research, and describe new initiatives to partner with similar platforms such as McGill's M3 platform (m3platform.org). 相似文献
3.
The economic loss due to pest attack in stored commodities is a serious problem worldwide. About 200 insect species attack stored commodities. These insect pests are responsible for quantitative and qualitative losses in cereal grains. Among the stored grain pests, Angoumois grain moth, Sitotroga cerealella is considered as common, top of the list and most destructive pest of cereal grains. Its infestation starts in the standing crop and continues in storage. Although there are many control strategies, our need is some effective, cheap and readily available strategy for safe storage. This review presents different ways by which S. cerealella can be controlled. In this paper, a list of approaches is given which are used to improve the protection of stored grains against S. cerealella attack. These approaches include use of edible oils, containers, synthetic chemicals, agricultural waste materials, plant derivatives, bacterial protoxins, biopesticides, biocontrol enhancers and semiochemicals. If these tactics are followed as combined strategies in a compatible manner, they can provide us an integrated pest management programme for the efficient control of S. cerealella in cereal grains. 相似文献
4.
5.
6.
7.
Sobia Nisa Mubarra Shoukat Yamin Bibi Samha Al Ayoubi Waqas Shah Saadia Masood Maimoona Sabir Syeda Asma Bano Abdul Qayyum 《Saudi Journal of Biological Sciences》2022,29(1):287-295
Endophytes are microorganisms residing within plant tissues. Bacterial endophytes are important sources for production of pharmaceutically important metabolites. Berberis lycium is an important medicinal plant and there exist no report regarding isolation and determination of bioactive potential of its bacterial endophytes. Therefore the present study was aimed to isolate and identify bacterial endophytes from Berberis lycium. The study resulted in isolation of 20 strains of bacterial endophytes. Based on their antibacterial activity three strains were identified as Bacillus cereus (LBL6), Bacillus thuringiensis (SBL3) and Bacillus anthracis (SBL4) on basis of 16SrRNA gene using universal primers. Crude ethyl acetate extracts of LBL6, SBL3 and SBL4 were further evaluated for antioxidant and antifungal activities. Moderate antioxidant activity (56 %) at a concentration of 1000 µg/mL was observed for LBL6 followed by 45 and 43 % activity by SBL4 and SBL3 respectively. Significant antifungal activity was observed against Aspergillus niger (60 %) and Aspergillus flavus (56 %) at concentration of 4 mg/mL of SBL3 and SBL4 respectively. GCMS analysis of extract (LBL6) exhibited presence of 12 bioactive secondary metabolites corresponding to antimicrobial, antifungal, antioxidant, antitumor and anticancer activities. In conclusion, present study highlighted the importance of Berberis lycium to host diverse bacterial endophytes of pharmaceutical importance. 相似文献
8.
Gaurav Kailash Sonkar Kumar Gaurav Atul Kumar Rai Sitaram Taigor Zafar Beg 《Ecohydrology》2023,16(2):e2497
9.
10.
Meloidogyne sasseri n. sp. is described and illustrated from American beachgrass (Ammophila breviliffulata) originally collected from Henlopen State Park and Fenwick Island near the Maryland state line in Delaware, United States (6). Its relationship to M. graminis, M. spartinae, and M. californiensis is discussed. Primary distinctive characters of the female perineal pattern were a high to rounded arch with shoulders, widely spaced lateral lines interrupting transverse striations, a sunken vulva and anus, and coarse broken striae around the anal area. Second-stage juvenile body length was 554 μm (470-550), stylet length 14 μm (13-14.5), tail length 93 μm (83-115), tapering to a finely rounded terminus. Male stylet length 20 μm (19-21.5), spicule length 33 μm (30-36). Scanning electron microscope observations provided additional details of perineal patterns and face views of the female, male, and J2 head. Wheat, rice, oat, Ammophila sp., Panicum sp., bermudagrass, zoysiagrass and St. Augustinegrass were tested as hosts. Distribution of the species was the coasts of Delaware and Maryland. The common name "beachgrass root-knot" is proposed for M. sasseri n. sp. 相似文献