全文获取类型
收费全文 | 692篇 |
免费 | 59篇 |
专业分类
751篇 |
出版年
2023年 | 6篇 |
2022年 | 13篇 |
2021年 | 25篇 |
2020年 | 14篇 |
2019年 | 17篇 |
2018年 | 16篇 |
2017年 | 19篇 |
2016年 | 33篇 |
2015年 | 37篇 |
2014年 | 51篇 |
2013年 | 60篇 |
2012年 | 64篇 |
2011年 | 64篇 |
2010年 | 27篇 |
2009年 | 30篇 |
2008年 | 51篇 |
2007年 | 35篇 |
2006年 | 35篇 |
2005年 | 29篇 |
2004年 | 28篇 |
2003年 | 30篇 |
2002年 | 27篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1991年 | 2篇 |
1986年 | 1篇 |
1984年 | 2篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1973年 | 3篇 |
1968年 | 2篇 |
排序方式: 共有751条查询结果,搜索用时 0 毫秒
741.
Ricardo N. Martínez Cecilia Apaldetti Carina E. Colombi Angel Praderio Eliana Fernandez Paula Santi Malnis Gustavo A. Correa Diego Abelin Oscar Alcober 《Proceedings. Biological sciences / The Royal Society》2013,280(1772)
Sphenodontians were a successful group of rhynchocephalian reptiles that dominated the fossil record of Lepidosauria during the Triassic and Jurassic. Although evidence of extinction is seen at the end of the Laurasian Early Cretaceous, they appeared to remain numerically abundant in South America until the end of the period. Most of the known Late Cretaceous record in South America is composed of opisthodontians, the herbivorous branch of Sphenodontia, whose oldest members were until recently reported to be from the Kimmeridgian–Tithonian (Late Jurassic). Here, we report a new sphenodontian, Sphenotitan leyesi gen. et sp. nov., collected from the Upper Triassic Quebrada del Barro Formation of northwestern Argentina. Phylogenetic analysis identifies Sphenotitan as a basal member of Opisthodontia, extending the known record of opisthodontians and the origin of herbivory in this group by 50 Myr. 相似文献
742.
Kap‐Hoon Han Yoon‐Hee Chun Bárbara De Castro Pimentel Figueiredo Frederico Marianetti Soriani Marcela Savoldi Agostinho Almeida Fernando Rodrigues Charlie Timothy Cairns Elaine Bignell Jaqueline Moisés Tobal Maria Helena S. Goldman Jong‐Hwan Kim Yong‐Sun Bahn Gustavo Henrique Goldman Márcia Eliana Da Silva Ferreira 《Molecular microbiology》2010,76(3):802-802
743.
744.
745.
Fuoco Natalia Langenfeld de Oliveira Rafael Guilen Marcelino Monica Yonashiro Stessuk Talita Sakalem Marna Eliana Medina Denis Aloisio Lopes Modotti Waldir Pereira Forte Andresa Ribeiro-Paes João Tadeu 《Molecular biology reports》2020,47(4):2475-2486
Molecular Biology Reports - Classical methods used for culture of adipose-derived mesenchymal stromal cells (ADSCs) use xenobiotic components, which may present a potential risk for biological... 相似文献
746.
747.
Camilla A. S. Valença Ana A. T. Barbosa Eliana B. Souto Elina B. Caramão Sona Jain 《化学与生物多样性》2021,18(11):e2100549
Bacteria can produce nitrogenous compounds via both primary and secondary metabolic processes. Many bacterial volatile nitrogenous compounds produced during the secondary metabolism have been identified and reported for their antioxidant, antibacterial, antifungal, algicidal and antitumor activities. The production of these nitrogenous compounds depends on several factors, including the composition of culture media, growth conditions, and even the organic solvent used for their extraction, thus requiring their identification in specific conditions. In this review, we describe the volatile nitrogenous compounds produced by bacteria especially focusing on their antimicrobial activity. We concentrate on azo-compounds mainly pyrazines and pyrrolo-pyridines reported for their activity against several microorganisms. Whenever significant, extraction and identification methods of these compounds are also mentioned and discussed. To the best of our knowledge, this is first review describing volatile nitrogenous compounds from bacteria focusing on their biological activity. 相似文献
748.
Larissa Mayumi Bueno Dianelli Lisboa Caun Manuela Tosi Comelis Mateus Rodrigues Beguelini Sebastião Roberto Taboga Eliana Morielle-Versute 《Acta zoologica》2019,100(3):245-256
The Neotropical bat species Artibeus planirostris and Eptesicus furinalis present a different morphology of the female reproductive organs: the first presents a simplex uterus, while the second presents a bicornuate uterus, but there is no information about their ovaries. Our aim was to compare the general ovary morphology and the folliculogenesis process in these species to increase the knowledge about the reproductive diversity of tropical bats. We observed a morphological distinction between the ovaries of both species: A. planirostris presents the primordial follicles located in a cranial portion of the ovary and the interstitial gland cells are not distinctive, while in E. furinalis, the primordial follicles are located throughout the cortex, and there is an abundance of interstitial gland cells. Both species present binovular or triovular follicles. Artibeus planirostris is a monovular species, with a preferential ovulation in the left side. Some females of E. furinalis exhibited two corpora lutea in the same ovary, and others presented a corpus luteum in both right and left ovaries at the same time; thus, E. furinalis is a polyovular species. Our results express the variation between two Neotropical species, reflecting the great variation in the reproductive aspects in Chiroptera. 相似文献
749.
750.