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91.
Irene Ramos Elena Carnero Dabeiba Bernal-Rubio Christopher W. Seibert Liset Westera Adolfo García-Sastre Ana Fernandez-Sesma 《Journal of virology》2013,87(5):2430-2440
The influenza virus nonstructural protein 1 (NS1) inhibits innate immunity by multiple mechanisms. We previously reported that NS1 is able to inhibit the production of type I interferon (IFN) and proinflammatory cytokines in human primary dendritic cells (DCs). Here, we used recombinant viruses expressing mutant NS1 from the A/Texas/36/91 and A/Puerto Rico/08/34 strains in order to analyze the contribution of different NS1 domains to its antagonist functions. We show that the polyadenylation stimulating factor 30 (CPSF30) binding function of the NS1 protein from A/Texas/36/91 influenza virus, which is absent in the A/Puerto Rico/08/34 strain, is essential for counteracting these innate immune events in DCs. However, the double-stranded RNA (dsRNA) binding domain, present in both strains, specifically inhibits the induction of type I IFN genes in infected DCs, while it is essential only for inhibition of type I IFN proteins and proinflammatory cytokine production in cells infected with influenza viruses lacking a functional CPSF30 binding domain, such as A/Puerto Rico/08/34. 相似文献
92.
Leticia Ramos de Arvelos Vanessa Custódio Afonso Rocha Gabriela Pereira Felix Cleine Chagas da Cunha Morun Bernardino Neto Mario da Silva Garrote Filho Conceição de Fátima Pinheiro Elmiro Santos Resende Nilson Penha-Silva 《The Journal of membrane biology》2013,246(3):231-242
The stability of the erythrocyte membrane, which is essential for the maintenance of cell functions, occurs in a critical region of fluidity, which depends largely on its composition and the composition and characteristics of the medium. As the composition of the erythrocyte membrane is influenced by several blood variables, the stability of the erythrocyte membrane must have relations with them. The present study aimed to evaluate, by bivariate and multivariate statistical analyses, the correlations and causal relationships between hematologic and biochemical variables and the stability of the erythrocyte membrane against the chaotropic action of ethanol. The validity of this type of analysis depends on the homogeneity of the population and on the variability of the studied parameters, conditions that can be filled by patients who undergo bariatric surgery by the technique of Roux-en-Y gastric bypass since they will suffer feeding restrictions that have great impact on their blood composition. Pathway analysis revealed that an increase in hemoglobin leads to decreased stability of the cell, probably through a process mediated by an increase in mean corpuscular volume. Furthermore, an increase in the mean corpuscular hemoglobin (MCH) leads to an increase in erythrocyte membrane stability, probably because higher values of MCH are associated with smaller quantities of red blood cells and a larger contact area between the cell membrane and ethanol present in the medium. 相似文献
93.
Cleoni Alves Mendes de Lima Harrison Magdinier Gomes Maraníbia Aparecida Cardoso Oelemann Jesus Pais Ramos Paulo Cezar Caldas Carlos Eduardo Dias Campos Márcia Aparecida da Silva Pereira Fátima Fandinho Onofre Montes Maria do Socorro Calixto de Oliveira Philip Noel Suffys Maria Manuela da Fonseca Moura 《Memórias do Instituto Oswaldo Cruz》2013,108(4):457-462
The main cause of pulmonary tuberculosis (TB) is infection with
Mycobacterium tuberculosis (MTB). We aimed to evaluate the
contribution of nontuberculous mycobacteria (NTM) to pulmonary disease in
patients from the state of Rondônia using respiratory samples and
epidemiological data from TB cases. Mycobacterium isolates were identified using
a combination of conventional tests, polymerase chain reaction-based restriction
enzyme analysis of hsp65 gene and hsp65 gene
sequencing. Among the 1,812 cases suspected of having pulmonary TB, 444 yielded
bacterial cultures, including 369 cases positive for MTB and 75 cases positive
for NTM. Within the latter group, 14 species were identified as
Mycobacterium abscessus, Mycobacterium
avium, Mycobacterium fortuitum,
Mycobacterium intracellulare, Mycobacterium
gilvum, Mycobacterium gordonae,
Mycobacterium asiaticum, Mycobacterium
tusciae, Mycobacterium porcinum,
Mycobacterium novocastrense, Mycobacterium
simiae, Mycobacterium szulgai,
Mycobacterium phlei and Mycobacterium
holsaticum and 13 isolates could not be identified at the species
level. The majority of NTM cases were observed in Porto Velho and the relative
frequency of NTM compared with MTB was highest in Ji-Paraná. In approximately
half of the TB subjects with NTM, a second sample containing NTM was obtained,
confirming this as the disease-causing agent. The most frequently observed NTM
species were M. abscessus and M. avium and
because the former species is resistant to many antibiotics and displays
unsatisfactory cure rates, the implementation of rapid identification of
mycobacterium species is of considerable importance. 相似文献
94.
Huaiwei Liu Kristine Rose M. Ramos Kris Niño G. Valdehuesa Grace M. Nisola Won-Keun Lee Wook-Jin Chung 《Applied microbiology and biotechnology》2013,97(8):3409-3417
Ethylene glycol (EG) is an important platform chemical with steadily expanding global demand. Its commercial production is currently limited to fossil resources; no biosynthesis route has been delineated. Herein, a biosynthesis route for EG production from d-xylose is reported. This route consists of four steps: d-xylose?→?d-xylonate?→?2-dehydro-3-deoxy-d-pentonate?→?glycoaldehyde?→?EG. Respective enzymes, d-xylose dehydrogenase, d-xylonate dehydratase, 2-dehydro-3-deoxy-d-pentonate aldolase, and glycoaldehyde reductase, were assembled. The route was implemented in a metabolically engineered Escherichia coli, in which the d-xylose?→?d-xylulose reaction was prevented by disrupting the d-xylose isomerase gene. The most efficient construct produced 11.7 g?L?1 of EG from 40.0 g?L?1 of d-xylose. Glycolate is a carbon-competing by-product during EG production in E. coli; blockage of glycoaldehyde?→?glycolate reaction was also performed by disrupting the gene encoding aldehyde dehydrogenase, but from this approach, EG productivity was not improved but rather led to d-xylonate accumulation. To channel more carbon flux towards EG than the glycolate pathway, further systematic metabolic engineering and fermentation optimization studies are still required to improve EG productivity. 相似文献
95.
96.
Capsule Timing of breeding influenced wing-length at fledging, and egg size may be an indicator of fledging weight and the amount of food received by chicks. Aims To investigate chick growth, temporal patterns of chick food provisioning and the importance of indices of parental condition or quality, egg size and hatching date, to predict nestling body mass and wing-length at fledging, and compare breeding and chick feeding characteristics between colonies in the northeast Atlantic. Methods A survey of Cory's Shearwater nests was carried out at Vila islet. A sample of 52 chicks, ringed and weighed at hatching, was selected to study chick growth and food provisioning. Results Hatching success (51%) was much lower than fledging success (87%). Both hatching date and egg size contributed to explain wing-length at fledging, but hatching date, which was negatively correlated with wing-length at fledging, had the most important contribution (22%). There was some indication that egg size may explain variation in fledging weight and the amount of food received by chicks. Food delivery and feeding frequency of chicks varied throughout the chick development stage and three phases were distinguished: (1) 0–29 days, the highest feeding frequency values and a linear increase in food delivery; (2) 30–69 days, an oscillation in food delivery and medium feeding frequencies; (3) 70–90+ days, a sharp decrease in both food delivery and feeding frequency. Conclusion Variation in food availability did not seem sufficient to override the overall importance of indices of parental quality in determining reproductive measures and chick provisioning. Breeding and feeding characteristics were similar between colonies in the northeast Atlantic, with variability in chick provisioning higher further south. 相似文献
97.
Steven A. Nadler Eugene T. Lyons Christopher Pagan Derek Hyman Edwin E. Lewis Kimberlee Beckmen Cameron M. Bell Aurelie Castinel Robert L. DeLong Padraig J. Duignan Cher Farinpour Kathy Burek Huntington Thijs Kuiken Diana Morgades Soraya Naem Richard Norman Corwin Parker Paul Ramos Terry R. Spraker Bárbara Berón-Vera 《International journal for parasitology》2013
Hookworms of the genus Uncinaria have been widely reported from juvenile pinnipeds, however investigations of their systematics has been limited, with only two species described, Uncinaria lucasi from northern fur seals (Callorhinus ursinus) and Uncinaria hamiltoni from South American sea lions (Otaria flavescens). Hookworms were sampled from these hosts and seven additional species including Steller sea lions (Eumetopias jubatus), California sea lions (Zalophus californianus), South American fur seals (Arctocephalus australis), Australian fur seals (Arctocephalus pusillus), New Zealand sea lions (Phocarctos hookeri), southern elephant seals (Mirounga leonina), and the Mediterranean monk seal (Monachus monachus). One hundred and thirteen individual hookworms, including an outgroup species, were sequenced for four genes representing two loci (nuclear ribosomal DNA and mitochondrial DNA). Phylogenetic analyses of these sequences recovered seven independent evolutionary lineages or species, including the described species and five undescribed species. The molecular evidence shows that U. lucasi parasitises both C. ursinus and E. jubatus, whereas U. hamiltoni parasitises O. flavescens and A. australis. The five undescribed hookworm species were each associated with single host species (Z. californianus, A. pusillus, P. hookeri, M. leonina and M. monachus). For parasites of otarids, patterns of Uncinaria host-sharing and phylogenetic relationships had a strong biogeographic component with separate clades of parasites from northern versus southern hemisphere hosts. Comparison of phylogenies for these hookworms and their hosts suggests that the association of U. lucasi with northern fur seals results from a host-switch from Steller sea lions. Morphometric data for U. lucasi shows marked host-associated size differences for both sexes, with U. lucasi individuals from E. jubatus significantly larger. This result suggests that adult growth of U. lucasi is reduced within the host species representing the more recent host–parasite association. Intraspecific host-induced size differences are inconsistent with the exclusive use of morphometrics to delimit and diagnose species of Uncinaria from pinnipeds. 相似文献
98.
Luca Ferretti Sebastián E. Ramos‐Onsins Miguel Pérez‐Enciso 《Molecular ecology》2013,22(22):5561-5576
Next generation sequencing of pooled samples is an effective approach for studies of variability and differentiation in populations. In this paper we provide a comprehensive set of estimators of the most common statistics in population genetics based on the frequency spectrum, namely the Watterson estimator , nucleotide pairwise diversity Π, Tajima's D, Fu and Li's D and F, Fay and Wu's H, McDonald‐Kreitman and HKA tests and , corrected for sequencing errors and ascertainment bias. In a simulation study, we show that pool and individual θ estimates are highly correlated and discuss how the performance of the statistics vary with read depth and sample size in different evolutionary scenarios. As an application, we reanalyse sequences from Drosophila mauritiana and from an evolution experiment in Drosophila melanogaster. These methods are useful for population genetic projects with limited budget, study of communities of individuals that are hard to isolate, or autopolyploid species. 相似文献
99.
Vijay M. Shahani Daniel P. Ball Allan V. Ramos Zhihua Li Paul A. Spagnuolo Sina Haftchenary Aaron D. Schimmer Suzanne Trudel Patrick T. Gunning 《Bioorganic & medicinal chemistry》2013,21(17):5618-5628
A focused library of hetero-trisubstituted purines was developed for improving the cell penetrating and biological efficacy of a series of anti-Stat3 protein inhibitors. From this SAR study, lead agent 22e was identified as being a promising inhibitor of MM tumour cells (IC50’s <5 μM). Surprisingly, biophysical and biochemical characterization proved that 22e was not a Stat3 inhibitor. Initial screening against the kinome, prompted by the purine scaffold’s history for targeting ATP binding pockets, suggests possible targeting of the JAK family kinases, as well for ABL1 (nonphosphorylated F317L) and AAK1. 相似文献
100.
Davi Rodrigo Rossatto William Arthur Hoffmann Lucas de Carvalho Ramos Silva Mundayatan Haridasan Leonel S. L. Sternberg Augusto César Franco 《Trees - Structure and Function》2013,27(4):1139-1150
The ecology of forest and savanna trees species will largely determine the structure and dynamics of the forest–savanna boundaries, but little is known about the constraints to leaf trait variation imposed by selective forces and evolutionary history during the process of savanna invasion by forest species. We compared seasonal patterns in leaf traits related to leaf structure, carbon assimilation, water, and nutrient relations in 10 congeneric species pairs, each containing one savanna species and one forest species. All individuals were growing in dystrophic oxisols in a fire-protected savanna of Central Brazil. We tested the hypothesis that forest species would be more constrained by seasonal drought and nutrient-poor soils than their savanna congeners. We also hypothesized that habitat, rather than phylogeny, would explain more of the interspecific variance in leaf traits of the studied species. We found that throughout the year forest trees had higher specific leaf area (SLA) but lower integrated water use efficiency than savanna trees. Forest and savanna species maintained similar values of predawn and midday leaf water potential along the year. Lower values were measured in the dry season. However, this was achieved by a stronger regulation of stomatal conductance and of CO2 assimilation on an area basis (A area) in forest trees, particularly toward the end of the dry season. Relative to savanna trees, forest trees maintained similar (P, K, Ca, and Mg) or slightly higher (N) leaf nutrient concentrations. For the majority of traits, more variance was explained by phylogeny, than by habitat of origin, with the exception of SLA, leaf N concentration, and A area, which were apparently subjected to different selective pressures in the savanna and forest environments. In conclusion, water shortage during extended droughts would be more limiting for forest trees than nutrient-poor soils. 相似文献