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171.
Nicolli Bellotti de Souza Isabel M de Andrade Paula F Carneiro Guilherme AM Jardim Isadora MM de Melo Eufranio N da Silva Júnior Antoniana Ursine Krettli 《Memórias do Instituto Oswaldo Cruz》2014,109(5):546-552
Due to the recent advances of atovaquone, a naphthoquinone, through clinical trials
as treatment for malarial infection, 19 quinone derivatives with previously reported
structures were also evaluated for blood schizonticide activity against the malaria
parasite Plasmodium falciparum. These compounds include 2-hydroxy-3-methylamino
naphthoquinones (2-9), lapachol (10), nor-lapachol (11), iso-lapachol (12), phthiocol
(13) and phenazines (12-20). Their cytotoxicities were also evaluated against human
hepatoma and normal monkey kidney cell lines. Compounds 2 and 5 showed the highest
activity against P. falciparum chloroquine-resistant blood-stage parasites (clone
W2), indicated by their low inhibitory concentration for 50% (IC50) of
parasite growth. The therapeutic potential of the active compounds was evaluated
according to the selectivity index, which is a ratio of the cytotoxicity minimum
lethal dose which eliminates 50% of cells and the in vitro IC50.
Naphthoquinones 2 and 5, with activities similar to the reference antimalarial
chloroquine, were also active against malaria in mice and suppressed parasitaemia by
more than 60% in contrast to compound 11 which was inactive. Based on their in vitro
and in vivo activities, compounds 2 and 5 are considered promising molecules for
antimalarial treatment and warrant further study. 相似文献
172.
Camila Carlos Mathias M Pires Nancy C Stoppe Elayse M Hachich Maria IZ Sato Tânia AT Gomes Luiz A Amaral Laura MM Ottoboni 《BMC microbiology》2010,10(1):161
Background
Escherichia coli strains are commonly found in the gut microflora of warm-blooded animals. These strains can be assigned to one of the four main phylogenetic groups, A, B1, B2 and D, which can be divided into seven subgroups (A0, A1, B1, B22, B23, D1 and D2), according to the combination of the three genetic markers chuA, yjaA and DNA fragment TspE4.C2. Distinct studies have demonstrated that these phylo-groups differ in the presence of virulence factors, ecological niches and life-history. Therefore, the aim of this work was to analyze the distribution of these E. coli phylo-groups in 94 human strains, 13 chicken strains, 50 cow strains, 16 goat strains, 39 pig strains and 29 sheep strains and to verify the potential of this analysis to investigate the source of fecal contamination. 相似文献173.
The anti-algal activity of five macrophyte extracts on the cyanobacterium Microcystis aeruginosa in Egypt was investigated in 2013. Extract activity varied according to plant type, extracting solvent and its concentration. The highest inhibitory activity was achieved with ethanol extract at a concentration of 80 mg l?1, followed by chloroformic extracts, at 60 mg l?1. Methanolic extracts of Eichhornia crassipes and Polygonum tomentosum inhibited growth of Microcystis aeruginosa at all concentrations. Acetonic extracts inhibited algal growth at 60 mg l?1, except for the extract of Ceratophyllum subdemersum, which showed stimulation of M. aeruginosa growth. Eichhornia crassipes ethanolic extract exerted the most powerful inhibition by more than five-fold, 570.17%, followed by those of P. tomentosum, Saccharum spontaneum, Ceratophyllum demersum and C. subdemersum, 559.48, 553.99, 544.11 and 366.51%, respectively. Phytochemical screening for the tested plant extracts revealed the presence of biologically active substances of different concentrations, with P. tomentosum having the highest polyphenols, 1.95% of dry weight. 相似文献
174.
175.
176.
Diverse stakeholders and multiple management options pose challenges to restoration planning and management. Analytic hierarchy process (AHP), a multicriteria decision‐making tool, can be effectively used for incorporating stakeholders' perceptions in planning. By using Red sanders (Pterocarpus santalinus L.) restoration as a case study, we demonstrate its suitability in eliciting stakeholders' perceptions about the most suitable management option, and their expectations from it. Four key stakeholder groups, Administrators, Field Officers, Community, and Knowledgeable Sources, were used to identify the most suitable management option from Government Management (GM), Quasi‐Government Management, Community Forest Management (CFM), and Private Management. Results indicate that stakeholders' preferences for management options were not homogeneous. Consolidated priorities across all the stakeholder groups indicated the CFM (34%) as the most preferred option followed by the GM (31%). With an average weight of 56%, the ecological criterion was considered as the most important. The ability of the managements in reducing disturbances (23%), improving Red sanders density (18%), improving ecosystem services (15%), and in improving rural livelihoods (15%) were considered important. The preferences of the Administrators and the Field Officers for the GM indicated their support for the top‐down management approach, and skepticism toward the CFM, a bottom‐up approach. Compared to the Administrators, the Field Officers' lack of support for the CFM was surprisingly more pronounced. Results indicate the usefulness of the AHP technique in identifying common grounds between the diverse stakeholders, and the management, in identifying a suitable management alternative and in prioritizing preferences. 相似文献
177.
178.
Hygrocybe rubida, a new species in subsection Squamulosae of section Coccinea, collected from tropical evergreen forests of Western Ghats of Kerala is formally described. The species is characterized by a bright red, dry pileus and stipe; ovoid to subamygdaliform spores; a distinctly sterile lamella-edge with crowded cheilocystidia and a trichodermial pileipellis. 相似文献
179.
This paper unfolds the events, the people and the times that led up to the
founding of AChemS and fashioned its character during its early formative
years. It describes the path over which AChemS came, going from the
original assertions and denials for the need of such an organization to its
later inception and nascent development. This narration highlights such
topics as the debate over the need for AChemS, the role of National Science
Foundation in the founding of AChemS, the derivation of the Association's
name, the choice of Sarasota and the Hyatt House as the meeting site, the
generation of the programs for the early annual meetings, the adoption of
the bylaws, the process of incorporation and tax deferment, and the birth
of the Givaudan Lectureship. Most emphatically highlighted, however, is the
enthusiasm, commitment and hard work that the members of the chemosensory
research community displayed in bringing AChemS to fruition.
相似文献
180.
The role of species richness, functional diversity and species identity of native Florida sandhill understory species were
tested with Imperata cylindrica, an exotic rhizomatous grass, in mesocosms. I. cylindrica was introduced 1 year after the following treatments were established: a control with no native species, five monocultures,
a grass mix treatment, a forb mix treatment, and a 3-species treatment and a 5-species treatment. Monthly cover, final biomass,
root length, root length density (RLD) and specific root length (SRL) of all species were determined for one full growing
season. There was a significant negative linear relationship between the cover of native species and I. cylindrica (r
2 = 0.59, P = 0.01) and a negative logarithmic relationship between the biomass of native species and I. cylindrica (r
2 = 0.70, P = 0.003). There was no diversity–invasibility relationship. Grasses proved to be the most resistant functional group providing
resistance alone and in mixed functional communities. Repeated measures analysis demonstrated that treatments including Andropogon virginicus were the most resistant to invasion over time (P < 0.001). Significantly greater root length (P = 0.002), RLD (P = 0.011) and SRL (P < 0.001) than all of the native species and I. cylindrica in monocultures and in mixed communities made A. virginicus successful. The root morphology characteristics allowed it to be a great competitor belowground where I. cylindrica was most aggressive. The results suggest that species identity could be more important than species or functional richness
in determining community resistance to invasion. 相似文献