全文获取类型
收费全文 | 734篇 |
免费 | 43篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 14篇 |
2021年 | 32篇 |
2020年 | 19篇 |
2019年 | 20篇 |
2018年 | 30篇 |
2017年 | 32篇 |
2016年 | 34篇 |
2015年 | 48篇 |
2014年 | 32篇 |
2013年 | 48篇 |
2012年 | 52篇 |
2011年 | 71篇 |
2010年 | 40篇 |
2009年 | 33篇 |
2008年 | 35篇 |
2007年 | 35篇 |
2006年 | 36篇 |
2005年 | 25篇 |
2004年 | 15篇 |
2003年 | 19篇 |
2002年 | 13篇 |
2001年 | 18篇 |
2000年 | 8篇 |
1999年 | 12篇 |
1998年 | 3篇 |
1997年 | 6篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1978年 | 2篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1966年 | 2篇 |
1965年 | 3篇 |
1961年 | 1篇 |
1960年 | 2篇 |
1959年 | 1篇 |
1957年 | 3篇 |
1951年 | 1篇 |
排序方式: 共有777条查询结果,搜索用时 250 毫秒
111.
112.
Soares Mayara Sandrielly Pereira Luduvico Karina Pereira Chaves Vitor Clasen Spohr Luiza Meine Bernardo de Moraes Lencina Claiton Leoneti Reginatto Flávio Henrique Spanevello Roselia Maria Simões Cláudia Maria Oliveira Stefanello Francieli Moro 《Neurochemical research》2021,46(5):1129-1140
Neurochemical Research - Neuroinflammation is an event that occurs in several pathologies of brain. Rubus sp. (blackberry) is a powerful antioxidant fruit, and its extract has neuroprotective... 相似文献
113.
114.
Camila Marques-da-Silva Mariana M. Chaves Maria Luiza Thorstenberg Vanessa R. Figliuolo Flávia S. Vieira Suzana P. Chaves José Roberto Meyer-Fernandes Bartira Rossi-Bergmann Luiz Eduardo Baggio Savio Robson Coutinho-Silva 《Purinergic signalling》2018,14(2):201-211
Leishmania amazonensis is the etiologic agent of cutaneous leishmaniasis, an immune-driven disease causing a range of clinical symptoms. Infections caused by L. amazonensis suppress the activation and function of immune cells, including macrophages, dendritic cells, and CD4+ T cells. In this study, we analyzed the course of infection as well as the leishmanicidal effect of intralesional UTP treatment in L. amazonensis-infected BALB/c mice. We found that UTP treatment reduced the parasitic load in both footpad and lymph node sites of infection. UTP also boosted Th1 immune responses, increasing CD4+ T cell recruitment and production of IFN-γ, IL-1β, IL-12, and TNF-α. In addition, the role of UTP during innate immune response against L. amazonensis was evaluated using the air pouch model. We observed that UTP augmented neutrophil chemoattraction and activated microbicidal mechanisms, including ROS production. In conclusion, our data suggested an important role for this physiological nucleotide in controlling L. amazonensis infection, and its possible use as a therapeutic agent for shifting immune responses to Th1 and increasing host resistance against L. amazonensis infection. 相似文献
115.
Boldness related to size in the hermit crab Coenobita compressus at undisturbed,but not disturbed beach 下载免费PDF全文
Mackenzie E. Hewes Johel Chaves‐Campos 《Ethology : formerly Zeitschrift fur Tierpsychologie》2018,124(8):570-578
There is growing interest in the consequences of consistent individual behavioral differences within and between populations. We compared the magnitude, repeatability, and plasticity of boldness in the terrestrial hermit crab Coenobita compressus in three habitats with different degrees of disturbance in Costa Rica. We encourage researchers to test additional sites to assess the generality of our results. Boldness decreased with crab size at the less disturbed sites, while no relationship between size and boldness was found at the disturbed site. Boldness increased with habitat disturbance, perhaps because bolder crabs succeed in exploiting food around people. Repeatability and plasticity were similar across sites. We hypothesize that population differences may be the result of developmental plasticity when aquatic larvae settle on a beach or selection for boldness at the disturbed site acting on each new generation. 相似文献
116.
Martins Paola Chaves Bastos Cibele Garcia Granjeiro Paulo Afonso Martins Vilásia Guimarães 《Bioprocess and biosystems engineering》2018,41(8):1177-1183
Bioprocess and Biosystems Engineering - Conventional biosurfactants have high production costs. Therefore, the use of low-cost carbon sources for their production is attractive for industry. The... 相似文献
117.
Carolina R. D. Boaventura-Novaes Evandro Novaes Elias E. S. Mota Mariana P. C. Telles Alexandre S. G. Coelho Lázaro J. Chaves 《Tree Genetics & Genomes》2018,14(5):76
Knowing how microevolutionary processes, such as genetic drift and natural selection, shape variation in adaptive traits is strategic for conservation measures. One way to estimate local adaptation is to compare divergences in quantitative traits (QST) and neutral loci (FST). Therefore, we have assessed the pattern of phenotypic and molecular genetic divergence among natural subpopulations of the fruit tree Eugenia dysenterica DC. A provenance and progeny test was performed to assess the quantitative traits of the subpopulations collected in a wide distribution area of the species in the Brazilian Cerrado. The sampled environments are in a biodiversity hotspot with heterogeneous soil and climate conditions. By associating quantitative trait variation in initial seedling development with neutral microsatellite marker variation, we tested the local adaptation of the traits by the QST–FST contrast. Genetic drift was prevalent in the phenotypic differentiation among the subpopulations, although the traits seedling emergence time and root green mass, which are relevant for adaptation to the Cerrado climate, showed signs of uniform selection. Our results suggest that E. dysenterica has a spatial genetic structure divided into two large groups, separated by a line that divides the Cerrado biome in a southwestern to northeastern direction. This structure must be taken into account for managing E. dysenterica genetic resources both for conservation and breeding purposes. 相似文献
118.
119.
José Cavalcante Souza Vieira Camila Pereira Braga Grasieli de Oliveira Cilene do Carmo Federici Padilha Paula Martin de Moraes Luiz Fabricio Zara Aline de Lima Leite Marília Afonso Rabelo Buzalaf Pedro de Magalhães Padilha 《Biological trace element research》2018,181(1):164-172
Poly-trans-[(2-carboxyethyl)germasesquioxane] (Ge-132) is a water-soluble organogermanium compound that exerts various physiological effects, including anti-inflammatory activity and pain relief. In water, Ge-132 is hydrolyzed to 3-(trihydroxygermyl)propanoic acid (THGP), which in turn is capable of interacting with cis-diol compounds through its trihydroxy group, indicating that this compound could also interact with diol-containing nucleic acid constituents. In this study, we evaluated the ability of THGP to interact with nucleosides or nucleotides via nuclear magnetic resonance (NMR) analysis. In addition, we evaluated the effect of added THGP on the enzymatic activity of adenosine deaminase (ADA) when using adenosine or 2′-deoxyadenosine as a substrate. In solution, THGP indeed formed complexes with nucleotides or nucleosides through their cis-diol group. Moreover, the ability of THGP to form complexes with nucleotides was influenced by the number of phosphate groups present on the ribose moiety. Notably, THGP also inhibited the catalysis of adenosine by ADA in a concentration-dependent manner. Thus, interactions between THGP and important biological nucleic acid constituents might be implicated in the physiological effects of Ge-132. 相似文献
120.
Evaluation of cDNA Libraries from Different Developmental Stages of Schistosoma mansoni for Production of Expressed Sequence Tags (ESTs) 总被引:9,自引:0,他引:9
Franco Gloria R.; Rabelo Elida M. L.; Azevedo Vasco; Pena Heloisa B.; Ortega J. Miguel; Santos Tulio M.; Meira Wendell S. F.; Rodrigues Neuza A.; Dias Carlos M. M.; Harrop Richard; Wilson Alan; Saber Mohamed; Abdel-Hamid Hannan; Faria Michelyne S. C.; Margutti Maria Elizabeth B.; Parra Jucara C.; Pena Seergio D. J. 《DNA research》1997,4(3):231-240
A comparative study of the gene expression profile in differentdevelopmental stages of Schistosoma mansoni has been initiatedbased on the expressed sequence tag(EST) approach. A total of1401 ESTs were generated from seven different cDNA librariesconstructed from four distinct stages of the parasite life cycle.The libraries were first evaluated for their quality for a large-scalecDNA sequencing program. Most of them were shown to have lessthan 20% useless clones and more than 50% new genes. The redundancyof each library was also analyzed, showing that one adult wormcDNA library was composed of a small number of highly frequentgenes. When comparing ESTs from distinct libraries, we coulddetect that most genes were present only in a single library,but others were expressed in more than one developmental stageand may represent housekeeping genes in the parasite. When consideringonly once the genes present in more than one library, a totalof 466 unique genes were obtained, corresponding to 427 newS. mansoni genes. From the total of unique genes, 20.2% wereidentified based on homology with genes from other organisms,8.3% matched S. mansoni characterized genes and 71.5% representunknown genes. 相似文献