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91.
92.
Crottini A Marotta R Barbuto M Casiraghi M Ferraguti M 《Molecular phylogenetics and evolution》2008,48(3):1189-1203
Tubifex tubifex Müller, 1774 is a cosmopolitan freshwater tubificid widely used as a model in ecotoxicology, population dynamics and developmental biology. It is traditionally recognized as a polytypic species and in Lambro River (Milano, Northern Italy) it occurs in two of the three recognized forms, named "tubifex" and "blanchardi", alternatively considered as ecological forms or distinct species. To investigate the genetic differentiation of the populations occurring in the Lambro River we sequenced a fragment of the 16S rDNA mitochondrial gene. T. blanchardi, characterized by a low genetic diversity, was genetically segregated from the other sympatric T. tubifex. The ancestral state reconstruction was used to define the morphological traits that support its distinctness. On the contrary, the other T. tubifex from the Lambro community, although morphologically indistinguishable, revealed an astonishing degree of genetic variability, both between and within the three identified clades that proved to be genetically isolated. Using samples from the mixed Lambro River community and from other countries around the world we present an overview of the species complex' 16S rDNA variability. Our results show that the genetic variability did not sensibly increase widening the data set, suggesting that the Lambro River populations meet the species' worldwide genetic variability. 相似文献
93.
The non-indigenous perennial grass, Arundo donax, is an aggressive invader of riparian areas throughout California and many sub-tropical regions of the world, and is hypothesized to provide poorer quality habitat for native wildlife in riparian systems. We sampled aerial and ground-dwelling insects and other terrestrial arthropods associated with Arundo, native willow vegetation (Salix spp.), and mixtures of the two vegetation types during two seasons to determine how Arundo influences invertebrate composition in a low gradient stream in central California. The total number of organisms, total biomass and taxonomic richness of aerial invertebrates associated with native vegetation was approximately twice that associated with Arundo vegetation, while mixed vegetation supported intermediate arthropod levels. Shannon-Weaver (Weiner) diversity associated with native vegetation stands was also higher than that of Arundo vegetation. Ground-dwelling assemblages did not show differences as great as aerial assemblages which are more critical to foraging avian species. These results indicate that vegetation type is a significant factor reducing the abundance and diversity of invertebrates in this, and presumably in many other riparian ecosystems where this invasive species has become a dominant component. Arundo invasion changes the vegetation structure of riparian zones and in turn, may increasingly jeopardize its habitat value for birds and other wildlife whose diets are largely composed of insects found in native riparian vegetation. 相似文献
94.
Angelica Crottini Janina Dordel Jrn Khler Frank Glaw Andreas Schmitz Miguel Vences 《Molecular phylogenetics and evolution》2009,53(1):345-350
A phylogeny for 29 species of scincine lizards from Madagascar, based on 3693 bp of six mitochondrial and five nuclear genes, revealed multiple parallel evolution of adaptations for a burrowing life, and unexpected relationships of the monotypic genera Androngo and Cryptoscincus. Androngo trivittatus was sister to Pygomeles braconnieri, and Cryptoscincus minimus was deeply nested within the genus Paracontias, all of these being fossorial taxa of elongated bodies and partly or fully reduced limbs. To account for these results, we place Cryptoscincus as a junior synonym of Paracontias, and discuss possible taxonomic consequences that may affect the status of Androngo, once additional data become available. 相似文献
95.
Ryan Tewhey Masakazu Nakano Xiaoyun Wang Carlos Pabón-Peña Barbara Novak Angelica Giuffre Eric Lin Scott Happe Doug N Roberts Emily M LeProust Eric J Topol Olivier Harismendy Kelly A Frazer 《Genome biology》2009,10(10):1-13
Background
Genome sequences, now available for most pathogens, hold promise for the rational design of new therapies. However, biological resources for genome-scale identification of gene function (notably genes involved in pathogenesis) and/or genes essential for cell viability, which are necessary to achieve this goal, are often sorely lacking. This holds true for Neisseria meningitidis, one of the most feared human bacterial pathogens that causes meningitis and septicemia.Results
By determining and manually annotating the complete genome sequence of a serogroup C clinical isolate of N. meningitidis (strain 8013) and assembling a library of defined mutants in up to 60% of its non-essential genes, we have created NeMeSys, a biological resource for Neisseria meningitidis systematic functional analysis. To further enhance the versatility of this toolbox, we have manually (re)annotated eight publicly available Neisseria genome sequences and stored all these data in a publicly accessible online database. The potential of NeMeSys for narrowing the gap between sequence and function is illustrated in several ways, notably by performing a functional genomics analysis of the biogenesis of type IV pili, one of the most widespread virulence factors in bacteria, and by identifying through comparative genomics a complete biochemical pathway (for sulfur metabolism) that may potentially be important for nasopharyngeal colonization.Conclusions
By improving our capacity to understand gene function in an important human pathogen, NeMeSys is expected to contribute to the ongoing efforts aimed at understanding a prokaryotic cell comprehensively and eventually to the design of new therapies. 相似文献96.
Claudia Kanashiro Tatiana C Santos Angelica Maria Miglino Andrea M Mess Anthony M Carter 《Reproductive biology and endocrinology : RB&E》2009,7(1):57-13
Background
The guinea pig is an attractive model for human pregnancy and placentation, mainly because of its haemomonochorial placental type, but is rather small in size. Therefore, to better understand the impact of body mass, we studied placental development in the capybara which has a body mass around 50 kg and a gestation period of around 150 days. We paid attention to the development of the lobulated arrangement of the placenta, the growth of the labyrinth in the course of gestation, the differentiation of the subplacenta, and the pattern of invasion by extraplacental trophoblast. 相似文献97.
Martin Montes Cesar Sanchez Kristien Verdonck Jordan E. Lake Elsa Gonzalez Giovanni Lopez Angelica Terashima Thomas Nolan Dorothy E. Lewis Eduardo Gotuzzo A. Clinton White Jr 《PLoS neglected tropical diseases》2009,3(6)
Background
Human strongyloidiasis varies from a chronic but limited infection in normal hosts to hyperinfection in patients treated with corticosteroids or with HTLV-1 co-infection. Regulatory T cells dampen immune responses to infections. How human strongyloidiasis is controlled and how HTLV-1 infection affects this control are not clear. We hypothesize that HTLV-1 leads to dissemination of Strongyloides stercoralis infection by augmenting regulatory T cell numbers, which in turn down regulate the immune response to the parasite.Objective
To measure peripheral blood T regulatory cells and Strongyloides stercoralis larval antigen-specific cytokine responses in strongyloidiasis patients with or without HTLV-1 co-infection.Methods
Peripheral blood mononuclear cells (PBMCs) were isolated from newly diagnosed strongyloidiasis patients with or without HTLV-1 co-infection. Regulatory T cells were characterized by flow cytometry using intracellular staining for CD4, CD25 and FoxP3. PBMCs were also cultured with and without Strongyloides larval antigens. Supernatants were analyzed for IL-5 production.Results
Patients with HTLV-1 and Strongyloides co-infection had higher parasite burdens. Eosinophil counts were decreased in the HTLV-1 and Strongyloides co-infected subjects compared to strongyloidiasis-only patients (70.0 vs. 502.5 cells/mm3, p = 0.09, Mann-Whitney test). The proportion of regulatory T cells was increased in HTLV-1 positive subjects co-infected with strongyloidiasis compared to patients with only strongyloidiasis or asymptomatic HTLV-1 carriers (median = 17.9% vs. 4.3% vs. 5.9 p<0.05, One-way ANOVA). Strongyloides antigen-specific IL-5 responses were reduced in strongyloidiasis/HTLV-1 co-infected patients (5.0 vs. 187.5 pg/ml, p = 0.03, Mann-Whitney test). Reduced IL-5 responses and eosinophil counts were inversely correlated to the number of CD4+CD25+FoxP3+ cells.Conclusions
Regulatory T cell counts are increased in patients with HTLV-1 and Strongyloides stercoralis co-infection and correlate with both low circulating eosinophil counts and reduced antigen-driven IL-5 production. These findings suggest a role for regulatory T cells in susceptibility to Strongyloides hyperinfection. 相似文献98.
Heiko Wurdak Shoutian Zhu Angelica Romero Mihaela Lorger James Watson Chih-yuan Chiang Jay Zhang Vanita S. Natu Luke L. Lairson John R. Walker Christopher M. Trussell Griffith R. Harsh Hannes Vogel Brunhilde Felding-Habermann Anthony P. Orth Loren J. Miraglia Daniel R. Rines Stephen L. Skirboll Peter G. Schultz 《Cell Stem Cell》2010,6(1):37-47
99.
Watanabe MA Nunes SO Nunes SO Amarante MK Guembarovski RL Oda JM Lima KW Fungaro MH 《Journal of genetics》2011,90(1):179-185
Data suggest that the serotonin (5-hydroxytryptamine, 5-HT) system is implicated in the pathogenesis of multiple neuropsychiatric
disorders and may also be involved in smoking behaviour since nicotine increases brain serotonin secretion. It is known that
smoking behaviour is influenced by both genetic and environmental factors. The present review examines the role of the serotonin
transporter gene (5-HTT) in smoking behaviour and investigating studies that showed association of 5-HTT gene with smoking.
This study discusses a polymorphism which has been investigated by many researchers, as the bi-allelic insertion/deletion
polymorphism in the 5′- flanking promoter region (5-HTTLPR). This gene has received considerable attention in attempts to understand the molecular
determinants of smoking. Therefore, in the present study, the relationship between genetic polymorphism of serotonin transporter
in smoking behaviour is reviewed considering the interactive effect of genetic factors. 相似文献
100.
Nicholas J Boddicker Angelica Bjorkquist Raymond RR Rowland Joan K Lunney James M Reecy Jack CM Dekkers 《遗传、选种与进化》2014,46(1):18