全文获取类型
收费全文 | 2148篇 |
免费 | 226篇 |
专业分类
2374篇 |
出版年
2023年 | 10篇 |
2022年 | 33篇 |
2021年 | 43篇 |
2020年 | 29篇 |
2019年 | 61篇 |
2018年 | 73篇 |
2017年 | 65篇 |
2016年 | 73篇 |
2015年 | 120篇 |
2014年 | 135篇 |
2013年 | 162篇 |
2012年 | 150篇 |
2011年 | 200篇 |
2010年 | 122篇 |
2009年 | 68篇 |
2008年 | 133篇 |
2007年 | 117篇 |
2006年 | 141篇 |
2005年 | 117篇 |
2004年 | 89篇 |
2003年 | 91篇 |
2002年 | 65篇 |
2001年 | 15篇 |
2000年 | 8篇 |
1999年 | 11篇 |
1998年 | 5篇 |
1997年 | 9篇 |
1996年 | 10篇 |
1995年 | 9篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 10篇 |
1990年 | 11篇 |
1988年 | 12篇 |
1987年 | 6篇 |
1986年 | 9篇 |
1985年 | 7篇 |
1984年 | 9篇 |
1983年 | 12篇 |
1982年 | 9篇 |
1981年 | 6篇 |
1980年 | 9篇 |
1979年 | 4篇 |
1978年 | 7篇 |
1977年 | 10篇 |
1976年 | 8篇 |
1975年 | 18篇 |
1974年 | 7篇 |
1973年 | 7篇 |
1970年 | 6篇 |
排序方式: 共有2374条查询结果,搜索用时 15 毫秒
71.
Angelika Noga Edyta Skrzypek Marzena Warchoł Ilona Czyczyło-Mysza Kinga Dziurka Izabela Marcińska Katarzyna Juzoń Tomasz Warzecha Agnieszka Sutkowska Zygmunt Nita Krystyna Werwińska 《In vitro cellular & developmental biology. Plant》2016,52(6):590-597
Obtaining oat DH lines is only effective via wide crossing with maize. Seven hundred haploid embryos from 21 single F1 progeny obtained from wide crosses with maize were isolated, divided into four groups according to their size (<0.5 mm, 0.5–0.9 mm, 1.0–1.4 mm, and ≥1.5 mm), and transferred into 190–2 regeneration medium with different growth regulators: 0.5 mg L?1 kinetin (KIN) and 0.5 mg L?1 1-naphthaleneacetic acid (NAA); 1 mg L?1 zeatin (ZEA) and 0.5 mg L?1 NAA; or 1 mg L?1 dicamba (DIC), 1 mg L?1 picloram (PIC), and 0.5 mg L?1 kinetin (KIN). Among all isolated embryos, approximately 46.1% were between 1.0–1.4 mm, while the smallest group of embryos (7.1%) were those <0.5 mm. The ability of haploid embryos to germinate varied depending on oat genotypes and the size of embryos. Haploid embryos <0.5 mm were globular and did not germinate, whereas embryos ≥1.5 mm had clearly visible coleoptiles, radicles, and scutella, and were able to germinate. Germination of oat haploid embryos varied depending on growth regulators in the regeneration medium. Most haploid embryos germinated on medium with 0.5 mg L?1 NAA and 0.5 mg L?1 KIN, while the fewest germinated on medium with 1 mg L?1 DIC, 1 mg L?1 PIC, and 0.5 mg L?1 KIN. One hundred thirty germinated haploid embryos converted into haploid plants. Fifty oat DH lines were obtained after colchicine treatment. 相似文献
72.
Journal of Physiology and Biochemistry - AMP-activated protein kinase (AMPK) is present in different kinds of metabolically active cells. AMPK is an important intracellular energy sensor and plays... 相似文献
73.
Emilia Hofman‐Kamiska Herv Bocherens Dorothe G. Drucker Ralph M. Fyfe Witold Gumiski Daniel Makowiecki Martina Pacher Giedr Pili
iauskien Tomasz Samojlik Jessie Woodbridge Rafa Kowalczyk 《Global Change Biology》2019,25(9):2915-2930
Climate warming and human landscape transformation during the Holocene resulted in environmental changes for wild animals. The last remnants of the European Pleistocene megafauna that survived into the Holocene were particularly vulnerable to changes in habitat. To track the response of habitat use and foraging of large herbivores to natural and anthropogenic changes in environmental conditions during the Holocene, we investigated carbon (δ13C) and nitrogen (δ15N) stable isotope composition in bone collagen of moose (Alces alces), European bison (Bison bonasus) and aurochs (Bos primigenius) in Central and Eastern Europe. We found strong variations in isotope compositions in the studied species throughout the Holocene and diverse responses to changing environmental conditions. All three species showed significant changes in their δ13C values reflecting a shift of foraging habitats from more open in the Early and pre‐Neolithic Holocene to more forest during the Neolithic and Late Holocene. This shift was strongest in European bison, suggesting higher plasticity, more limited in moose, and the least in aurochs. Significant increases of δ15N values in European bison and moose are evidence of a diet change towards more grazing, but may also reflect increased nitrogen in soils following deglaciation and global temperature increases. Among the factors explaining the observed isotope variations were time (age of samples), longitude and elevation in European bison, and time, longitude and forest cover in aurochs. None of the analysed factors explained isotope variations in moose. Our results demonstrate the strong influence of natural (forest expansion) and anthropogenic (deforestation and human pressure) changes on the foraging ecology of large herbivores, with forests playing a major role as a refugial habitat since the Neolithic, particularly for European bison and aurochs. We propose that high flexibility in foraging strategy was the key for survival of large herbivores in the changing environmental conditions of the Holocene. 相似文献
74.
75.
76.
77.
Jieyan He Tianshu Li Tomasz Próchnicki Gabor Horvath Eicke Latz Shinji Takeoka 《Biochemistry and Biophysics Reports》2019
Lysine (K) type cationic lipid with a propyl spacer and ditetradecyl hydrophobic moieties composing liposomes, K3C14, previously studied for gene delivery, were reported to activate the NLRP3 inflammasomes in human macrophages via the conventional phagolysosomal pathway. In this study, K3C16, a propyl spacer bearing lysine type lipids with dihexadecyl moieties (an extension of two hydrocarbon tail length) were compared with K3C14 as liposomes. Such a small change in tail length did not alter the physical properties such as size distribution, zeta potential and polydispersity index (PDI). The NLRP3 activation potency of K3C16 was shown to be 1.5-fold higher. Yet, the toxicity was minimal, whereas K3C14 has shown to cause significant cell death after 24 h incubation. Even in the presence of endocytosis inhibitors, cytochalasin D or dynasore, K3C16 continued to activate the NLRP3 inflammasomes and to induce IL-1β release. To our surprise, K3C16 liposomes were confirmed to fuse with the plasma membrane of human macrophages and CHO-K1 cells. It is demonstrated that the change in hydrophobic tail length by two hydrocarbons drastically changed a cellular entry route and potency in activating the NLRP3 inflammasomes. 相似文献
78.
79.
80.