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931.
Caroline Spitz dos Santos Bruno Pereira Berto Bruno do Bomfim Lopes Matheus Dias Cordeiro Adivaldo Henrique da Fonseca Walter Leira Teixeira Filho Carlos Wilson Gomes Lopes 《Systematic parasitology》2014,89(1):83-89
Klossiella tejerai Scorza, Torrealba & Dagert, 1957 is a primitive coccidian parasite reported from the New World marsupials Didelphis marsupialis (Linnaeus) and Marmosa demerarae (Thomas). The current work describes K. tejerai from the Brazilian common opossum Didelphis aurita (Wied-Neuwied) in Southeastern Brazil, evidencing the coccidial dispersion across opossums of the same family. The sporocysts recovered from urine samples were ellipsoidal, 20.4 × 12.7 µm, with sporocyst residuum composed of scattered spherules and c.13 sporozoites per sporocyst, with refractile bodies and nucleus. Macrogametes, microgametes, sporonts, sporoblasts/sporocysts were identified within parasitophorous vacuoles of epithelial cells located near the renal corticomedullary junction. Didelphis marsupialis should not have transmitted K. tejerai to D. aurita because they are not sympatric; however M. demerarae is sympatric with D. marsupialis and D. aurita. Therefore, D. aurita becomes the third host species for K. tejerai in South America. 相似文献
932.
Mrcia Gonalves Dias Brbara Baêsso Moura Giselle da Silva Pedrosa Silvia Ribeiro de Souza Poliana Cardoso‐Gustavson 《Nordic Journal of Botany》2019,37(11)
A role of non‐glandular emergences in avoiding ozone (O3) damages by preventing its entrance into leaf tissues has been suggested in the O3‐tolerant species Croton floribundus (Euphorbiaceae). However, this function against O3 damage has been underestimated due to the covering wax layer, mostly composed of saturated hydrocarbon, which has low O3 reactivity. To evaluate the role of these emergences in conferring tolerance to O3, we mechanically removed the non‐glandular emergences from leaf blades of C. floribundus, submitted the plants to acute O3 fumigation, and assessed morphological and microscopic alterations. Plants with intact leaves treated with O3 showed the same phenotype as control samples but showed microscopic indicators of accelerated senescence. These alterations indicated a whole‐plant response to O3. In contrast, plants whose leaves had got their emergences removed exhibited specific morphological symptoms as well as microscopic O3 damage. We thus conclude that the leaf emergences constitute a barrier for volatile contention, preventing O3 damage to leaf tissues in C. floribundus. When these structures have been removed, defense volatiles are possibly quickly dispersed, makes this species vulnerable to O3. This study highlights the relevance of surface structures for plant resistance to O3 damages, complementing biochemical defenses. 相似文献
933.
The 3-amino-1,2,4-triazole-modified silsesquioxane nanoplatforms have been prepared and characterized. The silsesquioxane nanocages readily react with CuX2 in aqueous solution to form copper complex-substituted silsesquioxanes. Adsorption isotherms of CuX2 from aqueous solution were studied at 25 °C. The electronic and ESR spectral parameters indicated that the copper ion is in a distorted-tetragonal symmetry field. 相似文献
934.
935.
Ana Luiza da R. F. Saraiva Aline da S. Bhering Margarida G. F. do Carmo Fernando D. Andreote Armando C.F. Dias Irene da S. Coelho 《Journal of Phytopathology》2020,168(11-12):613-619
The natural bacterial communities of the soil–plant system are relevant in the process of suppressing diseases caused by soilborne plant pathogens. However, little is known regarding the structure of these communities in soils cultivated with brassica vegetables and their relationship with clubroot severity, a disease caused by Plasmodiophora brassicae. In the present study, the composition of bacterial communities in soils cultivated with cauliflower with distinct levels of disease severity was compared. The bacterial composition in soils with lower and higher clubroot severity differs in phylum and genera levels. Soils associated with plants with lower disease severity showed predominance of Kaistobacter, Flavisolibacter, Sphingobacterium, Koribacter, Nitrospira, Bradyrhizobium and Bacillus. Our study reinforces the importance of management strategies that promote improving the physical–chemical characteristics of soil, which are essential to modulate bacterial populations correlated with plant disease suppression. 相似文献
936.
Apoptosis as a mechanism for removal of mutated cells of Saccharomyces cerevisiae: the role of Grx2 under cadmium exposure 总被引:1,自引:0,他引:1
Gomes DS Pereira MD Panek AD Andrade LR Eleutherio EC 《Biochimica et biophysica acta》2008,1780(2):160-166
Cadmium is a strong mutagen that acts by inhibiting DNA mismatch repair, while its toxic effect seems to be related to an indirect oxidative stress that involves glutathione (GSH) mobilization. Among the roles of GSH is the protection of proteins against oxidative damage, by forming reversible mixed disulfides with cysteine residues, a process known as protein glutathionylation and catalyzed by glutaredoxins (Grx). In this current study, Saccharomyces cerevisiae cells deficient in GRX2, growing in 80 muM CdSO(4), showed high mitochondrial mutagenic rate, determined by frequency of mutants that had lost mitochondrial function (petite mutants), high tolerance and lower apoptosis induction. The mutant strain also showed decreased levels of glutathionylated-protein after cadmium exposure, which might difficult the signaling to apoptosis, leading to increased mutagenic rates. Taken together, these results suggest that Grx2 is involved with the apoptotic death induced by cadmium, a form of cellular suicide that might lead of removal of mutated cells. 相似文献
937.
The structure of the zooplankton community in an estuary adjacent to the Admiral álvaro Alberto Nuclear Power Plant at Angra
dos Reis, state of Rio de Janeiro, Brazil was studied from 2001 through 2005. At that time, the power plant had been operating
for 20 years. The results were compared with a previous study in 1991–1993. The zooplankton was sampled 4 times a year, in
vertical hauls using a 150 μm net, at two fixed points near the plant’s intake and discharge sites. Temperature, salinity,
and chlorophyll a were measured. The water of Ribeira Bay is warm, with salinities typical of Coastal Water and more saline waters. Zooplankton
density at the discharge site (Mean: 245,434 ind m−3, SD: 335,358 ind m−3) was higher than that at the intake site (Mean: 84,634 ind m−3, SD: 101,409 ind m−3). A total of 121 mesozooplankton taxa were recorded from 2001 to 2005. Copepoda constituted the most common taxon and comprised
more than 57% of the total zooplankton, followed by cladocers and gastropod larvae. A seasonal zooplankton cycle was observed
only during 2004; in other years, the plankton varied only between years. Overall mesozooplankton abundance at the discharge
site was similar to levels reported from the inner zone of this estuary in 1991–1993. Surface temperature was the important
factor structuring the zooplankton community at the discharge site. No effect on the mesozooplankton by passage through the
condensers could be discerned, and no permanent negative influence on the plankton populations could be detected.
Guest editors: U. M. Azeiteiro, I. Jenkinson & M. J. Pereira
Plankton Studies 相似文献
938.
Ragozo AM Yai RL Oliveira LN Dias RA Dubey JP Gennari SM 《The Journal of parasitology》2008,94(6):1259-1263
Sheep are important in the epidemiology of Toxoplasma gondii infection but little is known of ovine toxoplasmosis in Brazil. Antibodies to T. gondii were assayed in sera of 495 sheep from 36 counties of S?o Paulo State, Brazil, using the modified agglutination test (MAT titer > or =1:25) and found in 120 (24.2%). Samples of brain, heart, and diaphragm of 82 seropositive sheep were pooled, digested in pepsin, and bioassayed in mice. Toxoplasma gondii was isolated from tissue homogenates of 16 sheep and the isolates were designated TgShBr1-16. Six of the 16 T. gondii isolates killed 100% of infected mice. Results indicate that asymptomatic sheep can harbor mouse-virulent T. gondii, and hence they can serve as a source of infection for humans. 相似文献
939.
940.
Dias Albino A. Bezerra Rui M. Lemos Paula M. Nazaré Pereira A. 《World journal of microbiology & biotechnology》2003,19(9):969-975
Bioremediation is considered a promising eco-efficient alternative for industrial wastewater treatment. Particular attention is currently being given to biological degradation of synthetic dyes and more specifically to colour removal by fungi. This work looks at the extracellular enzymatic system of strain Euc-1. Its ability to decolourize 14 xenobiotic azo dyes was evaluated and compared with the well-known species Phanerochaete chrysosporium. Strain Euc-1 is a mesophilic white-rot basidiomycete, the main secreted ligninolytic enzyme being laccase (0.38 U ml–1). Although low manganese-dependent peroxidase activity (0.05 U ml–1) was also detected, neither lignin peroxidase nor aryl alcohol oxidase could be found in batch culture. Optimum pH values of 4.0 and 5.0 were obtained in the laccase-catalysed oxidation of guaiacol and syringaldazine, respectively. Laccase activity increased with the temperature rise up to 50–60 °C and remarkable thermal stability was observed at 50 °C with a half-life of 12 h and no deactivation within the first 2 h. Solid-plate decolourization studies showed that basidiomycete Euc-1 decolourized 11 azo dyes whereas P. chrysosporium only two. Moreover, it is shown that purified laccase from basidiomycete Euc-1 efficiently decolourizes the azo dye acid red 88. 相似文献