全文获取类型
收费全文 | 16933篇 |
免费 | 1303篇 |
国内免费 | 5篇 |
出版年
2023年 | 144篇 |
2022年 | 110篇 |
2021年 | 320篇 |
2020年 | 269篇 |
2019年 | 261篇 |
2018年 | 528篇 |
2017年 | 496篇 |
2016年 | 535篇 |
2015年 | 616篇 |
2014年 | 669篇 |
2013年 | 954篇 |
2012年 | 1420篇 |
2011年 | 1522篇 |
2010年 | 764篇 |
2009年 | 572篇 |
2008年 | 1179篇 |
2007年 | 1204篇 |
2006年 | 1151篇 |
2005年 | 1025篇 |
2004年 | 951篇 |
2003年 | 910篇 |
2002年 | 763篇 |
2001年 | 163篇 |
2000年 | 244篇 |
1999年 | 151篇 |
1998年 | 96篇 |
1997年 | 76篇 |
1996年 | 69篇 |
1995年 | 77篇 |
1994年 | 69篇 |
1993年 | 63篇 |
1992年 | 81篇 |
1991年 | 63篇 |
1990年 | 51篇 |
1989年 | 39篇 |
1988年 | 35篇 |
1987年 | 39篇 |
1986年 | 27篇 |
1985年 | 31篇 |
1984年 | 55篇 |
1983年 | 29篇 |
1982年 | 45篇 |
1981年 | 47篇 |
1980年 | 52篇 |
1979年 | 32篇 |
1978年 | 33篇 |
1977年 | 36篇 |
1976年 | 33篇 |
1975年 | 32篇 |
1974年 | 25篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Janne Alahuhta Sarian Kosten Munemitsu Akasaka Dominique Auderset Mattia M. Azzella Rossano Bolpagni Claudia P. Bove Patricia A. Chambers Eglantine Chappuis John Clayton Mary de Winton Frauke Ecke Esperança Gacia Gana Gecheva Patrick Grillas Jennifer Hauxwell Seppo Hellsten Jan Hjort Mark V. Hoyer Christiane Ilg Agnieszka Kolada Minna Kuoppala Torben Lauridsen En Hua Li Balázs A. Lukács Marit Mjelde Alison Mikulyuk Roger P. Mormul Jun Nishihiro Beat Oertli Laila Rhazi Mouhssine Rhazi Laura Sass Christine Schranz Martin Søndergaard Takashi Yamanouchi Qing Yu Haijun Wang Nigel Willby Xiao Ke Zhang Jani Heino 《Journal of Biogeography》2017,44(8):1758-1769
3.
A.C. Gonçalves T.D. Matos H.R. Simões-Teixeira M. Pimenta Machado M. Simão Ó.P. Dias M. Andrea G. Fialho H. Caria 《Gene》2014
Low-frequency sensorineural hearing loss (LFSNHL) is an unusual type of HL in which frequencies at 2000 Hz and below are predominantly affected. Most of the families with LFSNHL carry missense mutations in WFS1 gene, coding for wolframin. 相似文献
4.
Franciele Martini Marlon Régis Leite Suzan Gonçalves Rosa Isabella Pregardier Klann Cristina Wayne Nogueira 《Cell biochemistry and function》2020,38(2):213-221
Alzheimer's disease (AD) is a progressive neurodegenerative disorder that has generated scientific interest because of its prevalence in the population. Studies indicate that physical exercise promotes neuroplasticity and improves cognitive function in animal models and in human beings. The aim of the present study was to investigate the effects of strength exercise on the hippocampal protein contents and memory performance in mice subjected to a model of sporadic AD induced by streptozotocin (STZ). Swiss mice received two injections of STZ (3 mg/kg, intracerebroventricular). After 21 days, they began physical training using a ladde. Mice performed this protocol for 4 weeks. After the last exercise training session, mice performed the Morris Water Maze test. The samples of hippocampus were excised and used to determine protein contents of brain-derived neurotrophic factor (BDNF), extracellular signal-regulated kinase-Ca2+ (ERK), calmodulin-dependent protein kinase (CAMKII) and cAMP-response element-binding protein (CREB) signalling pathway. Strength exercise was effective against the decrease in the time spent and distance travelled in the target quadrant by STZ-injected mice. Strength exercise was also effective against the reduction of mature BDNF, tropomyosin receptor kinase B and neuronal nuclear antigen (NeuN) hippocampal protein levels in STZ mice. The decrease in the hippocampal ratio of pERK/ERK, pCAMKII/CAMKII and pCREB/CREB induced by STZ was reversed by strength exercise. Strength exercise decreased Bax/Bcl2 ratio in the hippocampus of STZ-injected mice. The present study demonstrates that strength exercise modulated the hippocampal BDNF/ERK-CAMKII/CREB signalling pathway and suppressed STZ-induced spatial memory impairment in mice. 相似文献
5.
Thaís P. Mello Ana Carolina Aor Diego S. Gonçalves Sergio H. Seabra Marta H. Branquinha 《Biofouling》2016,32(7):737-749
Reported herein is the ability of Scedosporium apiospermum, S. aurantiacum, S. minutisporum and Lomentospora prolificans conidia to adhere, differentiate into hyphae and form biofilms on both polystyrene and lung epithelial cells. To different degrees, all of the fungi adhered to polystyrene after 4 h, with a predominance of those with germinated conidia. Prolonged fungi–polystyrene contact resulted in the formation of a monolayer of intertwined mycelia, which was identified as a typical biofilm structure due to the presence of a viable mycelial biomass, extracellular matrix and enhanced antifungal resistance. Ultrastructural details were revealed by SEM and CLSM, showing the dense compaction of the mycelial biomass and the presence of channels within the organized biofilm. A similar biofilm structure was observed following the co-culture of each fungus with A549 cells, revealing a mycelial trap covering all of the lung epithelial monolayer. Collectively, these results highlight the potential for biofilm formation by these clinically relevant fungal pathogens. 相似文献
6.
Alessandra Bertassoni Guilherme Mourão Rullian César Ribeiro Clarice Silva Cesário Juliana Paula de Oliveira Rita de Cassia Bianchi 《Studies on Neotropical Fauna and Environment》2017,52(1):68-74
This study analyzes a giant anteater’s (Myrmecophaga tridactyla) movement patterns and space use in São Paulo, Brazil. It is the first study to track a giant anteater with Iridium-GPS. The anteater traveled an average distance of 1326 m day–1 with an average speed of 1.04 m min–1. Home range by Kernel was 2.46 km2 while the core area was 0.75 km2, and estimates by Brownian bridge and minimum convex polygon were also provided. The anteater used shrub savanna, open savanna, and water habitats more than expected. Monitoring ended just after 10 days when the female giant anteater’s GPS was found on an illegal trail. 相似文献
7.
8.
R. F. Oliveira V. C. Almada E. J. Gonçalves E. Forsgren A. V. M. Canario† 《Journal of fish biology》2001,58(4):897-908
Nest-holder male Salaria pavo have lower circulating concentrations of 11-ketotestosterone (KT) at the beginning of the breeding season than at its peak. At that peak density of nesting males was higher as were the number of visits of sneaker males to nests and of agonistic interactions between nest-holders and sneaker males. There was no difference between the two dates either in the frequency of male-male interactions or in the frequency of courtship episodes. Thus, higher plasma levels in nest-holders might be explained by a more intense sneaking pressure at the peak of the breeding season. At that peak, nest-holders had higher plasma levels of KT and a higher testosterone (T) to KT metabolization index in the gonads than did floater males. Both nest-holders and floaters had higher levels of KT and T in the testicular gland than in the testis. The levels of both androgens in the testicular gland, but not in the testis, were correlated with circulating concentrations of KT. These results suggest that the testicular gland is the major source of circulating KT in blenniids. Nest-holders had higher metabolization indexes than floaters both in the testis and in the testicular gland, which suggests that nest holding status promotes the conversion of T into KT. 相似文献
9.