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51.
52.
Salting Potency and Time‐Intensity Profile of Microparticulated Sodium Chloride in Shoestring Potatoes 下载免费PDF全文
53.
Targeting Ergosterol Biosynthesis in Leishmania donovani: Essentiality of Sterol 14alpha-demethylase
Laura-Isobel McCall Amale El Aroussi Jun Yong Choi Debora F. Vieira Geraldine De Muylder Jonathan B. Johnston Steven Chen Danielle Kellar Jair L. Siqueira-Neto William R. Roush Larissa M. Podust James H. McKerrow 《PLoS neglected tropical diseases》2015,9(3)
Leishmania protozoan parasites (Trypanosomatidae family) are the causative agents of cutaneous, mucocutaneous and visceral leishmaniasis worldwide. While these diseases are associated with significant morbidity and mortality, there are few adequate treatments available. Sterol 14alpha-demethylase (CYP51) in the parasite sterol biosynthesis pathway has been the focus of considerable interest as a novel drug target in Leishmania. However, its essentiality in Leishmania donovani has yet to be determined. Here, we use a dual biological and pharmacological approach to demonstrate that CYP51 is indispensable in L. donovani. We show via a facilitated knockout approach that chromosomal CYP51 genes can only be knocked out in the presence of episomal complementation and that this episome cannot be lost from the parasite even under negative selection. In addition, we treated wild-type L. donovani and CYP51-deficient strains with 4-aminopyridyl-based inhibitors designed specifically for Trypanosoma cruzi CYP51. While potency was lower than in T. cruzi, these inhibitors had increased efficacy in parasites lacking a CYP51 allele compared to complemented parasites, indicating inhibition of parasite growth via a CYP51-specific mechanism and confirming essentiality of CYP51 in L. donovani. Overall, these results provide support for further development of CYP51 inhibitors for the treatment of visceral leishmaniasis. 相似文献
54.
55.
Marcos A. L. Teixeira Pedro E. Vieira Fredrik Pleijel Bruno R. Sampieri Ascensão Ravara Filipe O. Costa Arne Nygren 《Zoologica scripta》2020,49(2):222-235
We report on two new lineages of the Eumida sanguinea complex from Great Britain and describe one of them as a new species using a multilocus approach, including the mitochondrial DNA COI-5P and the nuclear markers ITS (ITS1, 5.8S rRNA and ITS2) and 28S rRNA. The molecular analysis placed Eumida mackiei sp. nov. in a monophyletic clade with 19.1% (COI), 10.1% (ITS) and 1.7% (28S) mean distance to its nearest neighbour. Molecular diagnoses were also applied to nine lineages within the E. sanguinea complex. This was complemented with morphometric data employing multivariate statistical analysis and the incorporation of statistical dissimilarities against three other described species from the complex. Eumida mackiei sp. nov. can be distinguished from E. notata and E. maia by the larger distance between the eyes and differences in morphometric proportions mainly in the dorsal and ventral cirri as well as in the prostomial appendages. E. sanguinea sensu stricto failed to produce a cluster of its own in the morphometric analysis, probably due to juvenile bias. Integrative taxonomy provided strong evidence to formally describe a new cryptic species that can now be used in biomonitoring or other relevant ecological research. 相似文献
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57.
Valéria Cristina Rodrigues Iran José Oliveira da Silva Frederico Márcio Corrêa Vieira Sheila Tavares Nascimento 《International journal of biometeorology》2011,55(3):455-459
Researchers working with thermal comfort have been using enthalpy to measure thermal energy inside rural facilities, establishing
indicator values for many situations of thermal comfort and heat stress. This variable turned out to be helpful in analyzing
thermal exchange in livestock systems. The animals are exposed to an environment which is decisive for the thermoregulatory
process, and, consequently, the reactions reflect states of thermal comfort or heat stress, the last being responsable for
problems of sanity, behavior and productivity. There are researchers using enthalpy as a qualitative indicator of thermal
environment of livestock such as poultry, cattle and hogs in tropical regions. This preliminary work intends to check different
enthalpy equations using information from classical thermodynamics, and proposes a direct equation as thermal comfort index
for livestock systems. 相似文献
58.
Cristina Branquinho Paula MatosAna Rute Vieira Maria Margarida Prestello Ramos 《Environmental and Experimental Botany》2011,72(1):84-92
The relative impact of lichen photobiont and mycobiont was evaluated by submitting nine lichen species with: (i) different photobiont types; (ii) different lichen growth forms; and (iii) different nutrients, pH, humidity preferences; to a range of Cu concentrations (μM) supplied in repeated cycles to simulate the natural process of uptake under field conditions. The physiological performance of the photosystem II photochemical reactions was measured using Fv/Fm and the metabolic activity of the mycobiont was evaluated using ergosterol and intracellular K-loss as indicators. Lichens with higher cation exchange capacity showed higher intracellular Cu uptake and their ecology seemed to be associated with low-nutrient environments. Thus the wall and external matrix, mainly characteristic of the mycobiont partner, cannot be ignored as the first site of interaction of metals with lichens. No common intracellular Cu concentration threshold was found for the physiological impacts observed in the different species. Most physiological effects of Cu uptake in sensitive lichens occurred for intracellular Cu below 200 μg/g dw whereas more tolerant species were able to cope with intracellular Cu at least 3 times higher. Cyanobacterial lichens showed to be more sensitive to Cu uptake than green-algal lichens. Within the Trebouxia lichens, different species showed different sensitivities to Cu uptake, suggesting that the mycobiont may change the microenvironment close to the photobiont partner providing different degrees of protection. Despite the fact that the photobiont is the productive partner, the metabolic activity of the mycobiont of lichen species adapted to environments rich in nutrients, showed to be more sensitive to Cu uptake than the photochemical performance of the photobiont. 相似文献
59.
Eriston Vieira Gomes Lucas Breseguello
Do Nascimento Marcos Augusto
De Freitas Luiz Carlos Bhering Nasser Silvana Petrofeza 《Journal of Phytopathology》2011,159(2):94-99
Microsatellites are powerful markers to infer population genetic parameters. We used 10 microsatellite loci to characterize the genetic diversity and structure of 79 samples of Sclerotinia sclerotiorum isolated from four Brazilian dry bean populations and observed that eight of them were polymorphic within populations. We identified 102 different haplotypes ranging from 6 to 18 per locus. Analyses based on genetic diversity and fixation indices indicated variability among and within populations of 28.79% (FST = 28793) and 71.21%, respectively. To examine genetic relatedness among S. sclerotiorum isolates, we used internal spacer (ITS1‐5.8S‐ITS2) restriction fragment length polymorphism (PCR‐RFLP) and sequencing analysis. PCR‐RFLP analysis of these regions failed to show any genetic differences among isolates. However, we detected variability within the sequence, which does not support the hypothesis of clonal populations within each population. High variability within and among populations may indicate the introduction of new genotypes in the areas analysed, in addition to the occurrence of clonal and sexual reproduction in the populations of S. sclerotiorum in the Brazilian Cerrado. 相似文献
60.
Juliana Pereira Lyon Fábio Vieira dos Santos Pedro Claudio Guaranho de Moraes Leonardo Marmo Moreira 《Mycopathologia》2011,171(2):93-101
Candida yeasts are opportunistic pathogens responsible for infections in immunocompromised individuals. Among the virulence factors
present in these yeasts we can mention the ability to adhere to host cells, exoenzyme production and germ tube formation.
Several compounds, such as antifungal agents, plants extracts, protein inhibitors and surfactants, have been tested regarding
their capacity in inhibit Candida spp. virulence factors. Among these compounds, a significant lower number of works are focused on the inhibition action caused
by different types of surfactant. The present work aimed to evaluate the effect generated by the surfactants cetyltrimethylammonium
chloride (CTAC), sodium dodecyl sulfate (SDS), N-hexadecyl-N–N′-dimethyl-3-ammonio-1-propane-sulfonate (HPS) and octylphenoxypolyethoxyethanol (Triton X-100) on the viability, adhesion
ability and exoenzyme production by Candida species. CTAC and HPS were capable to inhibit Candida spp. growth at very low concentrations. All surfactants demonstrated to be capable to inhibit the adhesion of Candida species to buccal epithelial cells (BEC) and the proteinase production. On the other hand, the phospholipase production remained
unaltered after the treatment with these compounds. The present data denote that cationic and zwitterionic surfactants are
interesting prototypes of inhibitory agents against Candida spp., which is probably associated with the cationic punctual charge of both surfactants. The results are discussed in details
in agreement with recent reports from literature. 相似文献