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21.
Altered Na+ and Li+ Homeostasis in Saccharomyces cerevisiae Cells Expressing the Bacterial Cation Antiporter NhaA 下载免费PDF全文
Roc Ros Consuelo Montesinos Abraham Rimon Etana Padan Ramn Serrano 《Journal of bacteriology》1998,180(12):3131-3136
The bacterial Na+(Li+)/H+ antiporter NhaA has been expressed in the yeast Saccharomyces cerevisiae. NhaA was present in both the plasma membrane and internal membranes, and it conferred lithium but not sodium tolerance. In cells containing the yeast Ena1-4 (Na+, Li+) extrusion ATPase, the extra lithium tolerance conferred by NhaA was dependent on a functional vacuolar H+ ATPase and correlated with an increase of lithium in an intracellular pool which exhibited slow efflux of cations. In yeast mutants without (Na+, Li+) ATPase, lithium tolerance conferred by NhaA was not dependent on a functional vacuolar H+ ATPase and correlated with a decrease of intracellular lithium. NhaA was able to confer sodium tolerance and to decrease intracellular sodium accumulation in a double mutant devoid of both plasma membrane (Na+, Li+) ATPase and vacuolar H+ ATPase. These results indicate that the bacterial antiporter NhaA expressed in yeast is functional at both the plasma membrane and the vacuolar membrane. The phenotypes conferred by its expression depend on the functionality of plasma membrane (Na+, Li+) ATPase and vacuolar H+ ATPase. 相似文献
22.
Leticia Ruiz Garcia Consuelo Díaz de la Guardia Juan Francisco Mota 《Aerobiologia》1998,14(2-3):281-284
The first results are presented of an aerobiological analysis of the atmosphere of the town of Almería, carried out between
November 1995 and October 1996. A Lanzoni volumetric spore trap was used for sample collection. The composition and seasonal
evolution of the pollen spectrum were determined over a 1-year period in relation to the vegetation and climatic conditions
of the study area. Twenty-six pollen types were identified as accounting for >0.05% of the total pollen collected. The main
sources of airborne pollen were Palmae (17.76%),Olea (16.10%), Chenopodiaceae/Amaranthaceae (13.99%), Urticaceae (10.18%) and Poaceae (8.64%). The annual pollen variation presented
a period of maximum emission from March to June, with a subsequent, less intensive period from August to November. The minimum
pollen values were obtained from December to February. The highest concentrations occurred in May, which was also the month
which presented the highest pollen diversity, whereas the lowest values were observed in January. 相似文献
23.
Consuelo Latorre Fortes-Dias Roberta Márcia Marques dos Santos Angelo José Magro Marcos Roberto de Mattos Fontes Carlos Chávez-Olórtegui Claude Granier 《Biochimie》2009,91(11-12):1482-1492
Crotoxin (CA.CB) is a β-neurotoxin from Crotalus durissus terrificus snake venom that is responsible for main envenomation effects upon biting by this snake. It is a heterodimer of an acidic protein (CA) devoid of any biological activity per se and a basic, enzymatically active, PLA2 counterpart (CB). Both lethal and enzymatic activities of crotoxin have been shown to be inhibited by CNF, a protein from the blood of C. d. terrificus snakes. CNF replaces CA in the CA.CB complex, forming a stable, non-toxic complex CNF.CB. The molecular sites involved in the tight interfacial protein–protein interactions in these PLA2-based complexes have not been clearly determined. To help address this question, we used the peptide arrays approach to map possible interfacial interaction sites in CA.CB and CNF.CB. Amino acid stretches putatively involved in these interactions were firstly identified in the primary structure of CB. Further analysis of the interfacial availability of these stretches in the presumed biologically active structure of CB, suggested two interaction main sites, located at the amino-terminus and β-wing regions. Peptide segments at the carboxyl-terminus of CB were also suggested to play a secondary role in the binding of both CA and CNF. 相似文献
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25.
Antonia Monardes Safina Khan Christine Zalejski Juan Orellana László Szabados Consuelo de la Torre Csaba Koncz László Bögre 《The EMBO journal》2010,29(17):2979-2993
The 40S ribosomal protein S6 kinase (S6K) is a conserved component of signalling pathways controlling growth in eukaryotes. To study S6K function in plants, we isolated single‐ and double‐knockout mutations and RNA‐interference (RNAi)‐silencing lines in the linked Arabidopsis S6K1 and S6K2 genes. Hemizygous s6k1s6k2/++ mutant and S6K1 RNAi lines show high phenotypic instability with variation in size, increased trichome branching, produce non‐viable pollen and high levels of aborted seeds. Analysis of their DNA content by flow cytometry, as well as chromosome counting using DAPI staining and fluorescence in situ hybridization, revealed an increase in ploidy and aneuploidy. In agreement with this data, we found that S6K1 associates with the Retinoblastoma‐related 1 (RBR1)–E2FB complex and this is partly mediated by its N‐terminal LVxCxE motif. Moreover, the S6K1–RBR1 association regulates RBR1 nuclear localization, as well as E2F‐dependent expression of cell cycle genes. Arabidopsis cells grown under nutrient‐limiting conditions require S6K for repression of cell proliferation. The data suggest a new function for plant S6K as a repressor of cell proliferation and required for maintenance of chromosome stability and ploidy levels. 相似文献
26.
Consuelo Borrás Juan Gambini Raúl López-Grueso Federico V. Pallardó Jose Viña 《生物化学与生物物理学报:疾病的分子基础》2010,1802(1):205-211
Estrogens have antioxidant properties which are due to their ability to bind to estrogen receptors and to up-regulate the expression of antioxidant enzymes via intracellular signalling pathways. Mitochondria are key organelles in the development of age-associated cellular damage. Recently, estrogen receptors were identified in mitochondria. The aim of this paper was to test whether estradiol directly affects mitochondria by preventing oxidative stress and protecting frail mitochondria. Incubation with estradiol at normal intracellular concentrations prevents the formation of reactive oxygen species by mitochondria in a saturable manner. Moreover, estradiol protects mitochondrial integrity as indicated by an increase in mitochondrial membrane potential. It also prevents the apoptogenic leakage of cytochrome c from mitochondria and as a result the mitochondrial content of this cytochrome c is maintained high. Thus, estradiol prevents the onset of the mitochondrial pathway of apoptosis by a direct effect on the organelle. Genistein, a phytoestrogen present at high concentration in soy, mimics the protective effect of estradiol by both decreasing the rate of formation of reactive oxygen species and preventing the release of cytochrome c from mitochondria. 相似文献
27.
Pilar Caro José Gómez Alessandro Arduini Mónica González-Sánchez Miriam González-García Consuelo Borrás José Viña María J. Puertas Juan Sastre Gustavo Barja 《Mitochondrion》2010,10(5):479-486
Mitochondrial DNA (mtDNA) mutations increase with age. However, the number of cells with predominantly mutated mtDNA is small in old animals. Here a new hypothesis is proposed: mtDNA fragments may insert into nuclear DNA contributing to aging and related diseases by alterations in the nucleus. Real-time PCR quantification shows that sequences of cytochrome oxidase III and 16S rRNA from mtDNA are present in highly purified nuclei from liver and brain in young and old rats. The sequences of these insertions revealed that they contain single nucleotide polymorphisms identical to those present in mtDNA of the same animal. Interestingly, the amount of mitochondrial sequences in nuclear DNA increases with age in both tissues. In situ hybridization of mtDNA to nuclear DNA confirms the presence of mtDNA sequences inside nuclear DNA in rat hepatocytes. Bone marrow metaphase cells from both young and old rats show mtDNA at centromeric regions in 20 out of the 2n = 40 chromosomes. Consequently, mitochondria can be a major trigger of aging but the final target could also be the nucleus. 相似文献
28.
Angel Casacó Irene Beausoleil Bárbara Gonzalez Patricia Luaces Avelina León María E. Arteaga Pavel Prado Valia Rodríguez Aylén Pérez Grisel Guevara Ana M. Bada Nuris Ledón Dasha Fuentes Consuelo González Osvaldo Hernandez Romy Orphee Diuris Blanco Miriam García‐Osuma Alcides Ballester‐Labrada 《Journal of medical primatology》2010,39(3):177-186
Background The purpose of this study is to better characterize the hematological, biochemical, respiratory, cardiovascular and electroneurophysiological parameters in young adult Cercopithecus aethiops sabaeus of both sexes. The rhesus and cynomolgus monkeys are widely used as experimental primate models. However, only few articles have been published testing toxicological effects of pharmaceuticals on African green monkey. Methods The present study was carried out with the recompilation of all parameters recorded before the first drug administration in five sub‐chronic or chronic toxicological studies performed on 66 Cercopithecus aethiops sabaeus, born in Cuba. Results This study provides hematological, biochemical, respiratory, cardiovascular and electroneurophysiological data for both choosing animals to be included into experiments and monitoring these parameters during the study. Conclusions We conclude that this study provides valuable integrated data for determining the health status, including electroneurophysiological parameters, data not previously reported for this species, of the African green monkey. 相似文献
29.
Loganathan Ponnusamy Dawn M. Wesson Consuelo Arellano Coby Schal Charles S. Apperson 《Microbial ecology》2010,59(1):158-173
In the container habitats of immature mosquitoes, catabolism of plant matter and other organic detritus by microbial organisms
produces metabolites that mediate the oviposition behavior of Aedes aegypti and Aedes albopictus. Public health agencies commonly use oviposition traps containing plant infusions for monitoring populations of these mosquito
species, which are global vectors of dengue viruses. In laboratory experiments, gravid females exhibited significantly diminished
responses to experimental infusions made with sterilized white oak leaves, showing that attractive odorants were produced
through microbial metabolic activity. We evaluated effects of infusion concentration and fermentation time on attraction of
gravid females to infusions made from senescent bamboo or white oak leaves. We used plate counts of heterotrophic bacteria,
total counts of 4′,6-diamidino-2-phenylindole-stained bacterial cells, and 16S ribosomal DNA (rDNA) polymerase chain reaction–denaturing
gradient gel electrophoresis (DGGE) to show that changes in the relative abundance of bacteria and the species composition
of bacterial communities influenced attraction of gravid A. aegypti and A. albopictus mosquitoes to infusions. DGGE profiles showed that bacterial species composition in infusions changed over time. Principal
components analysis indicated that oviposition responses to plant infusions were in general most affected by bacterial diversity
and abundance. Analysis of bacterial 16S rDNA sequences derived from DGGE bands revealed that Proteobacteria (Alpha-, Beta-,
Delta-, and Gamma-) were the predominant bacteria detected in both types of plant infusions. Gravid A. aegypti were significantly attracted to a mix of 14 bacterial species cultured from bamboo leaf infusion. The oviposition response
of gravid mosquitoes to plant infusions is strongly influenced by abundance and diversity of bacterial species, which in turn
is affected by plant species, leaf biomass, and fermentation time. 相似文献
30.