全文获取类型
收费全文 | 497篇 |
免费 | 51篇 |
出版年
2023年 | 6篇 |
2022年 | 6篇 |
2021年 | 11篇 |
2020年 | 4篇 |
2019年 | 20篇 |
2018年 | 17篇 |
2017年 | 14篇 |
2016年 | 15篇 |
2015年 | 36篇 |
2014年 | 31篇 |
2013年 | 33篇 |
2012年 | 43篇 |
2011年 | 29篇 |
2010年 | 30篇 |
2009年 | 17篇 |
2008年 | 22篇 |
2007年 | 31篇 |
2006年 | 21篇 |
2005年 | 21篇 |
2004年 | 25篇 |
2003年 | 27篇 |
2002年 | 19篇 |
2001年 | 7篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 4篇 |
1993年 | 2篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1978年 | 1篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1968年 | 1篇 |
1955年 | 1篇 |
1943年 | 1篇 |
1942年 | 1篇 |
排序方式: 共有548条查询结果,搜索用时 15 毫秒
511.
M. A. Line 《Plant and Soil》1990,125(1):149-152
Nitrogen-fixing enterobacteria (Enterobacter agglomerans and Citrobacter freundii) were commonly found associated with the microflora of stained Sassafras (Atherosperma moschatum Labill.) in forests of SE Tasmania. However, their populations never exceeded 3× 104 cells g−1 dry wood and comprised at most 3% of the total bacterial flora. Bacterial colonization of the wood appeared to coincide with
that by non-hymenocetous fungi: bacteria were never isolated in significant numbers from wood not infected with fungi. The
contribution of the N2-fixing flora to the N economy of the habitat is considered to be negligible. 相似文献
512.
Attenuation of cGAS‐STING signaling is mediated by a p62/SQSTM1‐dependent autophagy pathway activated by TBK1
下载免费PDF全文
![点击此处可从《The EMBO journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Thaneas Prabakaran Chiranjeevi Bodda Christian Krapp Bao‐cun Zhang Maria H Christensen Chenglong Sun Line Reinert Yujia Cai Søren B Jensen Morten K Skouboe Jens R Nyengaard Craig B Thompson Robert Jan Lebbink Ganes C Sen Geert van Loo Rikke Nielsen Masaaki Komatsu Lene N Nejsum Martin R Jakobsen Mads Gyrd‐Hansen Søren R Paludan 《The EMBO journal》2018,37(8)
Negative regulation of immune pathways is essential to achieve resolution of immune responses and to avoid excess inflammation. DNA stimulates type I IFN expression through the DNA sensor cGAS, the second messenger cGAMP, and the adaptor molecule STING. Here, we report that STING degradation following activation of the pathway occurs through autophagy and is mediated by p62/SQSTM1, which is phosphorylated by TBK1 to direct ubiquitinated STING to autophagosomes. Degradation of STING was impaired in p62‐deficient cells, which responded with elevated IFN production to foreign DNA and DNA pathogens. In the absence of p62, STING failed to traffic to autophagy‐associated vesicles. Thus, DNA sensing induces the cGAS‐STING pathway to activate TBK1, which phosphorylates IRF3 to induce IFN expression, but also phosphorylates p62 to stimulate STING degradation and attenuation of the response. 相似文献
513.
Delphine Lariviere Emma Holmström Lisa Petersson Line Djupström Jan Weslien 《Agricultural and Forest Entomology》2023,25(3):416-426
- It is often suggested to release oaks (Quercus robur) from competition, to ensure their survival and boost their conservational value. However, few studies have explored how long-lasting this effect is and how it affects saproxylic beetles.
- Ten years after cutting, we investigated effects of different release cutting levels (high, medium, and no release) around 140-year-old retained oaks in a commercial forest with Norway spruce (Picea abies).
- We evaluated oak vitality using crown and dead wood measurements. Saproxylic beetles were caught in window traps, identified to species level, and grouped according to their association with oak and/or Norway spruce.
- Released oaks had more light, higher temperatures, greater crown growth, and less dead wood in the crown compared to the no-release control.
- After 10 years we still found a higher abundance of oak-associated beetles and higher overall species richness of saproxylic beetles in the released oaks. Beetle species composition significantly differed between released oaks and control.
- We suggest avoiding planting trees beneath retained oaks when regenerating conifer forests and to proceed with conservation management during subsequent thinning by removing regeneration under the oak crowns. We emphasize the benefits of monitoring the retained oaks to maintain tree vitality, habitat quality, and insolation.
514.
Valentina Rosu Mark S Chadfield Antonella Santona Jens P Christensen Line E Thomsen Salvatore Rubino John E Olsen 《Acta veterinaria Scandinavica》2007,49(1):14
Background
Salmonella enterica serotype Gallinarum (S. Gallinarum) remains an important pathogen of poultry, especially in developing countries. There is a need to develop effective and safe vaccines. In the current study, the effect of crp deletion was investigated with respect to virulence and biochemical properties and the possible use of a deletion mutant as vaccine candidate was preliminarily tested. 相似文献515.
516.
Mendes Cândida Dias Eduardo Rochefort Line Azevedo José 《Wetlands Ecology and Management》2020,28(1):177-190
Wetlands Ecology and Management - The study central goal was to analyze secondary succession in a degraded peatland: (1) Sphagnum distribution trends and (2) successional patterns. Main study sites... 相似文献
517.
Environmental enrichment devices are a potential way to enhance psychological well-being in laboratory animals. The effects of such devices need to be systematically evaluated before they are recommended for widespread use. The purpose of this research was to monitor the behavioural and physiological responses of adult female rhesus macaques to a simple enrichment device. The apparatus consisted of a box attached to the monkey's home cage that contained a radio and a food dispenser, which could be controlled by the monkeys via contact detectors. Radio and food dispenser use were automatically recorded. Whole blood serotonin (WBS), plasma cortisol and abnormal behaviour were measured in 5 monkeys before, during and after a 20-week period in which the monkey's cages were equipped with the device. All monkeys used the device (3 of the 5 subjects earned an average of more than 200 food pellets per day). Mean plasma cortisol and whole blood serotonin did not differ across sampling times, suggesting that the apparatus had no effect on basal stress levels. There was an inverse relationship between apparatus use and cortisol levels in 76% of the samples, but only 3 of 17 coefficients were significant. There was a significant but small negative correlation between apparatus use and self-abusive behaviour. This enrichment device was readily used by adult rhesus monkeys and could be adapted for use in a wide variety of laboratory settings. 相似文献
518.
Scott W. Line Kathleen N. Morgan Hal Markowitz Sharon Strong 《American journal of primatology》1990,20(2):107-113
Newly proposed federal regulations will mandate that singly caged non-human primates be kept in cages larger than the current minimum standard, or be given 4 hours in an exercise cage per week. In order to evaluate the effectiveness of increasing cage size in improving well-being, the behavioral and heart rate responses of 10 female rhesus monkeys (Macaca mulatta) to three different cage sizes were measured. With the exception of vocalizations, no significant differences in behavior were obtained. Grunts increased in the largest cage, following the birth of an infant in a cage within view of the test cages. No differences with respect to cage size were found in heart rate or activity level, although there were significant variations at different times of day. We conclude that modest increases in cage size are less likely to enrich the environment of singly caged laboratory primates than are changes in social opportunities or increases in environmental complexity. 相似文献
519.