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排序方式: 共有415条查询结果,搜索用时 31 毫秒
71.
Daniela Leles Paula Cascardo Elisa Pucu Beatriz Brener Adriana Sudré Elizabeth Alves Flávia Uchoa Priscilla Fajardo Patrícia Millar Danuza Mattos Márcia Chame Castor Cartelle 《Parasitology international》2018,67(6):776-780
The use of diagnostic methods that prevent irreplaceable samples (from museum collections, archaeological and paleontological samples) of being consumed or that increase their yield is relevant. For museum collections, archaeological and paleontological samples it is essential to conserve samples, subsamples or portions for future research. We are addressing methods for conservation of irreplaceable samples that could be fully consumed. Innovations in methodologies that are used in studies of Paleoparasitology and Paleomicrobiology will contribute to the preservation of collections. Therefore, to the development of archaeology and paleontology in the future, we evaluated whether the discarded material of the immunochromatography test could be used for molecular diagnosis and vice versa. We used a genotyped experimental coprolite positive for Giardia duodenalis. The diagnosis was positive for giardiasis in both cases. This methodology can be corroborated with the coprolite of a Paleolama maior (extinct llama) previously diagnosed for G. duodenalis with an immunoenzymatic test. The residue of the pre-digestion step of the DNA extraction before adding Proteinase K was confirmed positive with the immunochromatographic test. Also, the DNA extraction residue from a coprolite of Nothrotherium maquinense (ground sloth) was tested positive with immunochromatographic test for G. duodenalis. These are the oldest findings for G. duodenalis confirming that this intestinal parasite occurred among Northeastern Brazilian Megafauna animals from the late Pleistocene period, correlated to human occupation. The relevance of these results will allow the study by different methodological approaches from a small amount of material, reusing discarded materials. 相似文献
72.
Streptomyces coelicolor was grown in variously limited chemostat cultures and the specific rate of extracellular actinorhodin production (q(actinorhodin)) was measured. The highest q(actinorhodin) values were observed in glucose- or ammonia-limited cultures, whereas almost no actinorhodin was produced in sulfate-, phosphate-, potassium-, or magnesium-limited cultures. The effect of the dilution rate on actinorhodin production was studied in glucose-limited cultures. It was found that q(actinorhodin) was highest at D = 0.06h(-1), which was well below the maximal D value tested (0.14 h(-1)). This explains why, in batch cultures, actinorhodin production starts at the onset of the stationary phase. It was also found that the use of nitrilotriacetate instead of citrate as a chelating agent had a negative effect on actinorhodin production. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 53: 577-582, 1997. 相似文献
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Daniel Cunha Passos Paulo Cesar Mattos Dourado Mesquita Diva Maria Borges-Nojosa 《Studies on Neotropical Fauna and Environment》2016,51(1):19-28
We assessed the lizard assemblage from a priority conservation Caatinga area from northeastern Brazil, through a pluriannual ecological approach, to expand the understanding on biodiversity patterns of Neotropical semiarid habitats. The studied area presented one of the richest lizard faunas among Caatinga sites, being composed primarily by species typical from open landscapes. The local species composition was more similar to assemblages from adjacent Caatinga ecoregions than to those from other areas within the same ecoregion. The inventoried lizard assemblage consisted of a few common species and a majority of low abundance ones, and its overall richness and abundance did not differ between rainy and dry months. Our findings demonstrated that the composition of lizard assemblages did not match with the current proposed Caatinga ecoregions, and revealed that the studied assemblage followed a lognormal species-abundance distribution, showing no significant seasonal fluctuation in richness and abundance. 相似文献
75.
Denise Silva Nogueira Pedro Henrique Gazzinelli-Guimar?es Fernando Sérgio Barbosa Nathália Maria Resende Caroline Cavalcanti Silva Luciana Maria de Oliveira Chiara Cássia Oliveira Amorim Fabrício Marcus Silva Oliveira Matheus Silvério Mattos Lucas Rocha Kraemer Marcelo Vidigal Caliari Soraya Gaze Lilian Lacerda Bueno Remo Castro Russo Ricardo Toshio Fujiwara 《PLoS neglected tropical diseases》2016,10(1)
Ascaris spp. infection affects 800 million people worldwide, and half of the world population is currently at risk of infection. Recurrent reinfection in humans is mostly due to the simplicity of the parasite life cycle, but the impact of multiple exposures to the biology of the infection and the consequences to the host’s homeostasis are poorly understood. In this context, single and multiple exposures in mice were performed in order to characterize the parasitological, histopathological, tissue functional and immunological aspects of experimental larval ascariasis. The most important findings revealed that reinfected mice presented a significant reduction of parasite burden in the lung and an increase in the cellularity in the bronchoalveolar lavage (BAL) associated with a robust granulocytic pulmonary inflammation, leading to a severe impairment of respiratory function. Moreover, the multiple exposures to Ascaris elicited an increased number of circulating inflammatory cells as well as production of higher levels of systemic cytokines, mainly IL-4, IL-5, IL-6, IL-10, IL-17A and TNF-α when compared to single-infected animals. Taken together, our results suggest the intense pulmonary inflammation associated with a polarized systemic Th2/Th17 immune response are crucial to control larval migration after multiple exposures to Ascaris. 相似文献
76.
Ed T. Buurman José L. Boiardi M. Joost Teixeira de Mattos Oense M. Neijssel 《Archives of microbiology》1990,153(5):502-505
Magnesium-limited chemostat cultures of Klebsiella pneumoniae NCTC 418 with 20 M CaCl2 in the medium showed a low rate of gluconate plus 2-ketogluconate production relative to potassium- or phosphate-limited cultures. However, when the medium concentration of CaCl2 was increased to 1 mM, the glucose dehydrogenase (GDH) activities also increased and became similar to those observed in potassium- or phosphate limited cultures. It is concluded that this is due to Mg2+ and Ca2+ ions being involved in the binding of pyrroloquinoline quinone (PQQ) to the GDH apoenzyme. There seems to be an absolute requirement of divalent cations for proper enzyme functioning and in this respect Ca2+ ions could replace Mg2+ ions. The high GDH activity which has been found in cells grown under Mg2–-limited conditions in the presence of higher concentrations of Ca2+ ions, is compatible with the earlier proposal that GDH functions as an auxiliary energy generating system involved in the maintenance of high transmembrane ion gradients.Abbreviations PQQ
pyrroloquinoline quinone
- GDH
glucose dehydrogenase (EC 1.1.99.17)
- GaDH
gluconate dehydrogenase (EC 1.1.99.3)
- CAP
chloramphenicol
- WB
Wurster's Blue [1,4-bis-(dimethylamino)-benzene perchlorate] 相似文献
77.
Establishment of the steady state in glucose-limited chemostat cultures of Klebsiella pneumoniae 总被引:3,自引:0,他引:3
M Rutgers M J Teixeira de Mattos P W Postma K Van Dam 《Journal of general microbiology》1987,133(2):445-451
To investigate the relationship between growth rate and concentration of the nutrient that limits growth, 'Klebsiella aerogenes' NCTC 418 (K. pneumoniae) was grown in a glucose-limited chemostat. The actual time required to establish a steady-state glucose concentration exceeded that expected theoretically. Apparently, there is a long-term adaptation of the cells to nutrient limitation. As yet, it is not clear whether this has a phenotypic or genetic origin. In the final steady state, the dependence of the growth rate on glucose concentration could be mathematically described equally well by a hyperbolic and by a logarithmic function. 相似文献
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80.
Erica J Reschly Afonso Celso Dias Bainy Jaco Joaquim Mattos Lee R Hagey Nathan Bahary Sripal R Mada Junhai Ou Raman Venkataramanan Matthew D Krasowski 《BMC evolutionary biology》2007,7(1):222