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821.
Isolates of entomopathogenic fungus Metarhizium anisopliae var. anisopliae were characterized using internal transcribed spacer-RFLP, ISSR and intron splice site primers. Thirty-seven isolates were studied, most of which were obtained from the sugar cane pest, Mahanarva fimbriolata (Hemiptera: Cercopidae) from Tangará da Serra, Southwest Mato Grosso State, Brazil. Internal transcribed spacer-RFLP did not differentiate the isolates of M. anisopliae var. anisopliae, while ISSR and intron primers identified three distinct groups. Variability among these groups was 96% for (GTG)(5) and 100% for the other primers. We found considerable genetic variability, even among isolates from the same geographical origin and host.  相似文献   
822.
A new genus of Tabanidae mimetic of flies is described: Muscotabanus new genus, Muscotabanus rafaeli new species, based on 12 females collected in the state of Amazonas, Brazil. It is presented a discussion for separating the new genus from Diachlorini species which resemblance with sarcophagids flies. It is characterised by striped thorax, banded abdomen, long slender palpus subequal antenna length, labella predominantly membranous, except for a narrow sclerotised plate, basicosta bare, wing hyaline and stigma brown.  相似文献   
823.
Brazil is one of the leading producers of soybeans and other annual crops, and in several regions landowners are required by law to maintain 20 % of their lands with natural vegetation (i.e. as “legal reserves”). However, there is a growing concern that some of these reserves will be subject to increased levels of disturbance or even be lost as a result of the ongoing legislation reforms. In this sense, studies that evaluate the conservation potential of retaining natural habitats within agricultural areas are of great importance. We assessed the efficiency with which remnants of natural vegetation conserve the native ant fauna in a context of intensive agriculture. We compared the structure of ground-dwelling ant assemblages between crop fields and reserves located in different farms. Ant species richness was much higher in the reserves than in the crops, and this pattern was consistent in spite of variations in the type of crop planted in each field, and in the size (39–149 ha) and vegetation (open or closed savanna) of the reserves. From 41.4 to 76.4 % of all species recorded within each farm were exclusively found in the reserves. Differences in species composition were strong not only because the reserves had much more species, but also because the species that were present in both habitats showed contrasting patterns of abundance in each habitat. Overall, our results highlight that even small remnants of natural vegetation can have a significant potential to maintain a higher diversity of ants within an agriculturally dominated landscape.  相似文献   
824.
Parkinson's disease (PD) is a chronic progressive motor disorder that may present with a spectrum of symptoms and disease severity. Therapy is frequently associated with motor fluctuations and dyskinesias; therefore, monitoring of motor fluctuations and daily abilities is important for adequate management. The Social Rhythm Metric (SRM) is a diary‐like questionnaire that quantifies the extent to which a person's life is regular vs. irregular on a daily basis with respect to event timing. Lifestyle regularity has been assessed by the SRM in other clinical situations. The aim of this study was to evaluate lifestyle regularity in a population with PD using the SRM and its relationship to clinical and therapeutic factors. Twenty‐eight consecutive patients with PD and 14 control subjects were studied. Severity of motor dysfunction was evaluated with the Unified Parkinson's Disease Rating Scale (UPDRS). Depressive symptoms were assessed with the Montgomery Asberg Depressive Rating Scale (MADRS), sleep quality with the Pittsburgh Sleep Quality Index (PSQI), and subjective daytime sleepiness with the Epworth sleepiness scale. Daily lifestyle regularity was assessed by the SRM for 2 weeks. Patients with PD had lower SRM scores than controls, and those with motor fluctuations had even lower scores (p=0.04). Patients with motor fluctuations showed more clinical disability (p=0.01), a worse quality of sleep (p=0.02), and more depressive symptoms (p=0.02). SRM results were correlated with PSQI values (p=0.016). Our findings show that the regularity of daily activities as measured by the SRM is disorganized in patients with PD and that this irregularity is related to sleep quality.  相似文献   
825.
Recent studies suggest that roads can significantly impact bat populations. Though bats are one of the most threatened groups of European vertebrates, studies aiming to quantify bat mortality and determine the main factors driving it remain scarce. Between March 16 and October 31 of 2009, we surveyed road-killed bats daily along a 51-km-long transect that incorporates different types of roads in southern Portugal. We found 154 road-killed bats of 11 species. The two most common species in the study area, Pipistrellus kuhlii and P. pygmaeus, were also the most commonly identified road-kill, representing 72 % of the total specimens collected. About two-thirds of the total mortality occurred between mid July and late September, peaking in the second half of August. We also recorded casualties of threatened and rare species, including Miniopterus schreibersii, Rhinolophus ferrumequinum, R. hipposideros, Barbastella barbastellus, and Nyctalus leisleri. These species were found mostly in early autumn, corresponding to the mating and swarming periods. Landscape features were the most important variable subset for explaining bat casualties. Road stretches crossing or in the vicinity of high-quality habitats for bats—including dense Mediterranean woodland (“montado”) areas, water courses with riparian gallery, and water reservoirs—yielded a significantly higher number of casualties. Additionally, more road-killed bats were recorded on high-traffic road stretches with viaducts, in areas of higher bat activity and near known roosts.  相似文献   
826.
827.

Background

Protein aggregation in the brain is a central hallmark in many neurodegenerative diseases. In Parkinson's disease, α-synuclein (α-Syn) is the major component of the intraneuronal inclusions found in the brains of patients. Current therapeutics is merely symptomatic, and there is a pressing need for developing novel therapies. Previously we showed that mannosylglycerate (MG), a compatible solute typical of marine microorganisms thriving in hot environments, is highly effective in protecting a variety of model proteins against thermal denaturation and aggregation in vitro.

Methods

Saccharomyces cerevisiae cells expressing eGFP-tagged α-Syn, were further engineered to synthesize MG. The number of cells with fluorescent foci was assessed by fluorescence microscopy. Fluorescence spectroscopy and transmission electron microscopy were used to monitor fibril formation in vitro.

Results

We observed a 3.3-fold reduction in the number of cells with α-Syn foci and mild attenuation of α-Syn-induced toxicity. Accordingly, sucrose gradient analysis confirmed a clear reduction in the size-range of α-Syn species in the cells. MG did not affect the expression levels of α-Syn or its degradation rate. Moreover, MG did not induce molecular chaperones (Hsp104, Hsp70 and Hsp40), suggesting the implication of other mechanisms for α-Syn stabilization. MG also inhibited α-Syn fibrillation in vitro.

Conclusions

MG acts as a chemical chaperone and the stabilization mechanism involves direct solute/protein interactions.

General significance

This is the first demonstration of the anti-aggregating ability of MG in the intracellular milieu. The work shows that MG is a good candidate to inspire the development of new drugs for protein-misfolding diseases.  相似文献   
828.
We describe for the first time the food web of insects associated with fruits and seed of Piptadenia gonoacantha (Fabaceae), and analyze their relationships with resource traits, such as biomass and fruit area. A total of 440 fruits of P. Gonoacantha were sampled in the city of Lavras, Minas Gerais, Brazil. We found twenty-one species of insects distributed in three trophic levels. The most widely sampled species was Acanthoscelides clitellarius (Coleoptera, Chrysomelidae, Bruchinae), the main consumer species of seeds. It was also verified the presence of Lepidoptera larvae consuming both seeds and the internal fruit tissue. Other species of herbivorous insects were found in low numbers. The food web was subdivided into one sub-web of 10 parasitoid species and one hyperparasitoid species associated to A. clitellarius and another one sub-web of four parasitoid species associated with Lepidoptera. For the parasitism rates, we obtained the following: 19.11% for the total food web, 17.93% for the A. clitellarius parasitism, and 36% for the Lepidoptera parasitism. The resource traits had influence on the oviposition behavior of A. clitellarius, where fruits with larger area showed more eggs of this species. Fruits with higher biomass showed greater abundance and richness of insects as well as more interactions. Seeds with higher biomass were more often used by herbivorous insects. The larval forms of Lepidoptera caused the greatest damage in seed biomass among herbivores. Seeds with parasitoids did not show a significant difference in biomass when compared to predated seeds.  相似文献   
829.
Mangroves of the semiarid Caatinga region of northeastern Brazil are being rapidly converted to shrimp pond aquaculture. To determine ecosystem carbon stocks and potential greenhouse gas emissions from this widespread land use, we measured carbon stocks of eight mangrove forests and three shrimp ponds in the Acaraú and Jaguaribe watersheds in Ceará state, Brazil. The shrimp ponds were paired with adjacent intact mangroves to ascertain carbon losses and potential emissions from land conversion. The mean total ecosystem carbon stock of mangroves in this semiarid tropical landscape was 413 ± 94 Mg C/ha. There were highly significant differences in the ecosystem carbon stocks between the two sampled estuaries suggesting caution when extrapolating carbon stock across different estuaries even in the same landscape. Conversion of mangroves to shrimp ponds resulted in losses of 58%–82% of the ecosystem carbon stocks. The mean potential emissions arising from mangrove conversion to shrimp ponds was 1,390 Mg CO2e/ha. Carbon losses were largely from soils which accounted for 81% of the total emission. Losses from soils >100 cm in depth accounted for 33% of the total ecosystem carbon loss. Soil carbon losses from shrimp pond conversion are equivalent to about 182 years of soil carbon accumulation. Losses from mangrove conversion are about 10‐fold greater than emissions from conversion of upland tropical dry forest in the Brazilian Caatinga underscoring the potential value for their inclusion in climate change mitigation activities.  相似文献   
830.
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