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排序方式: 共有3062条查询结果,搜索用时 15 毫秒
31.
F.J. Rodriguez L.A. García de la Rosa A. Alatorre J. Ibaez L. Godinez S. Gutierrez P. Herrasti 《Progress in Organic Coatings》2007,60(4):297-302
This paper reports the capacity of polypyrrole to reduce toxic hexavalent chromium (Cr(VI)). The influence of using different electrolytes during the polymer's synthesis has been studied. To improve the reduction of Cr(VI), the parameters considered were the polypyrrole morphology and the amount of conducting polymer. Polypyrrole obtained by cyclic voltammetry at a low sweep rate using KBr as supporting electrolyte showed better performance for Cr(VI) reduction compared to coatings obtained by constant potential or cyclic voltammetry at high sweep rates. 相似文献
32.
Castagna Claudia; Absil Philippe; Foidart Agnès; Balthazart Jacques 《Canadian Metallurgical Quarterly》1998,112(1):233
The authors investigated the behavioral actions of vasotocin (VT) in castrated testosterone-treated male Japanese quail. The appetitive and consummatory components of sexual behavior as well as the occurrence frequency of crows were inhibited, in a dose-dependent manner, by injections of VT. The authors observed opposite effects after injection of the V1 receptor antagonist, dPTyr(Me)AVP. Lower doses of VT were more active after central than after systemic injection, and effects of systemic injections of VT were blocked by a central injection of dPTyr(Me)AVP. The behavioral inhibition was associated with a modified diuresis after systemic but not central injection. These results provide direct evidence that VT affects male sexual behavior in quail by a direct action on the brain independent of its peripheral action on diuresis. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
33.
SF Brenière W Morochi MF Bosseno J Ordo?ez T Gutierrez F Vargas N Yaksic F Noireau 《Canadian Metallurgical Quarterly》1998,71(3):269-283
Triatoma sordida is the second species of Triatominae considered of epidemiological significance in Bolivia. Associated with Triatoma infestans in various regions, it is as yet the only triatomine species established in human dwellings in localities of Velasco province, Department of Santa Cruz. This domestication is considered as primary. Flagellate parasites were detected in 16.2% of domiciliary T. sordida and the kDNA-PCR confirmed the presence of Trypanosoma cruzi. Frequencies of T. cruzi clonets 20 and 39, common clonets in Bolivian domestic cycle (T. infestans), were established by their direct detection in feces using PCR and hybridization. These clonets present low frequencies in T. sordida and synanthropic mammals. Forty-six stocks were isolated and analysed by multilocus enzyme electrophoresis (MLEE). The MLEE showed a higher clonal diversity than in T. infestans domestic cycle and the genotypes were clustered in the two principal lineages of T. cruzi. Within each lineage, a broad variability was observed. Mixture of genotypes was mostly observed in mammals. The large diversity of T. cruzi in this cycle should be related to its sylvatic origin. Moreover, the current limited sample of stocks suggests a lineage association with specific hosts. 相似文献
34.
The influence of several sinter-HIP variables on the densification behaviour of silicon nitride-based ceramics has been investigated. The processing conditions were studied for Si3N4 powder mixtures containing controlled amounts of Y2O3+Al2O3 or Y2O3+MgO. The specimens were subjected to sinter-HIP cycles under argon or nitrogen atmospheres at various temperatures and pressures. The final density of the powder compacts exhibited a strong dependence not only on the applied pressure, the composition and the processing temperature, but also on the pressurization rate and the initial pressurization time. The microstructural changes induced by the application of high pressure were followed by transmission electron microscopy. On examination by TEM, large concentrations of dislocations, generated inside some-Si3N4 grains, were observed. Characterization of these dislocations showed thatb=0001 is their most frequently found Burgers vector. Also, two relaxation mechanisms, tending to release the stored energy of deformation in the-Si3N4 grains, namely grain penetration (a form of strain-induced boundary migration) and grain fragmentation (the formation of subgrains due to rearrangement of dislocations into low energy configurations), have been identified. The intergranular phases formed were characterized by energy dispersive X-ray spectroscopic analysis, X-ray diffraction and electron diffraction. The influence of different sinter-HIP cycles on the transformation of silicon nitride without additives was also investigated by X-ray diffractometry. 相似文献
35.
36.
Claudia Penna Saveria Femmin Fabrizio Caldera Alberto Rubin Pedrazzo Claudio Cecone Edoardo Alfì Stefano Comit Takanobu Higashiyama Francesco Trotta Pasquale Pagliaro Roberta Cavalli 《International journal of molecular sciences》2021,22(8)
Heart failure (HF) prevalence is increasing among the aging population, and the mortality rate remains unacceptably high despite improvements in therapy. Myocardial ischemia (MI) and, consequently, ischemia/reperfusion injury (IRI), are frequently the basis of HF development. Therefore, cardioprotective strategies to limit IRI are mandatory. Nanocarriers have been proposed as alternative therapy for cardiovascular disease. Controlled reoxygenation may be a promising strategy. Novel nanocarriers, such as cyclic nigerosyl-nigerose (CNN), can be innovative tools for oxygen delivery in a controlled manner. In this study we analyzed new CNN-based formulations as oxygen nanocarriers (O2-CNN), and compared them with nitrogen CNN (N2-CNN). These different CNN-based formulations were tested using two cellular models, namely, cardiomyoblasts (H9c2), and endothelial (HMEC) cell lines, at different concentrations. The effects on the growth curve during normoxia (21% O2, 5% CO2 and 74% N2) and their protective effects during hypoxia (1% O2, 5% CO2 and 94% N2) and reoxygenation (21% O2, 5% CO2 and 74% N2) were studied. Neither O2-CNN nor N2-CNN has any effect on the growth curve during normoxia. However, O2-CNN applied before hypoxia induces a 15–30% reduction in cell mortality after hypoxia/re-oxygenation when compared to N2-CNN. O2-CNN showed a marked efficacy in controlled oxygenation, which suggests an interesting potential for the future medical application of soluble nanocarrier systems for MI treatment. 相似文献
37.
Serena Montalbano Francesca Degola Jennifer Bartoli Franco Bisceglie Annamaria Buschini Mauro Carcelli Donatella Feretti Serena Galati Laura Marchi Nicol Orsoni Giorgio Pelosi Marianna Pioli Francesco M. Restivo Dominga Rogolino Mirco Scaccaglia Olga Serra Giorgio Spadola Gaia C. V. Viola Ilaria Zerbini Claudia Zani 《International journal of molecular sciences》2021,22(9)
The control of the fungal contamination on crops is considered a priority by the sanitary authorities of an increasing number of countries, and this is also due to the fact that the geographic areas interested in mycotoxin outbreaks are widening. Among the different pre- and post-harvest strategies that may be applied to prevent fungal and/or aflatoxin contamination, fungicides still play a prominent role; however, despite of countless efforts, to date the problem of food and feed contamination remains unsolved, since the essential factors that affect aflatoxins production are various and hardly to handle as a whole. In this scenario, the exploitation of bioactive natural sources to obtain new agents presenting novel mechanisms of action may represent a successful strategy to minimize, at the same time, aflatoxin contamination and the use of toxic pesticides. The Aflatox® Project was aimed at the development of new-generation inhibitors of aflatoxigenic Aspergillus spp. proliferation and toxin production, through the modification of naturally occurring molecules: a panel of 177 compounds, belonging to the thiosemicarbazones class, have been synthesized and screened for their antifungal and anti-aflatoxigenic potential. The most effective compounds, selected as the best candidates as aflatoxin containment agents, were also evaluated in terms of cytotoxicity, genotoxicity and epi-genotoxicity to exclude potential harmful effect on the human health, the plants on which fungi grow and the whole ecosystem. 相似文献
38.
39.
Elizabeth?Gutierrez Tong?WangEmail author 《Journal of the American Oil Chemists' Society》2004,81(10):971-977
Soybeans are believed to be a rich source of sphingolipids, a class of polar lipids that has received attention for their
possible cancer-inhibiting activities. The effect of processing on the sphingolipid content of various soybean products has
not been determined. Glucosylceramide (GlcCer), the major sphingolipid type in soybeans, was measured in several processed
soybean products to illustrate which product(s) GlcCer is partitioned into during processing and where it is lost. Whole soybeans
were processed into full-fat flakes, from which crude oil was extracted. Crude oil was refined by conventional methods, and
defatted soy flakes were further processed into alcohol-washed and acid-washed soy protein concentrates (SPC) and soy protein
isolates (SPI) by laboratory-scale methods that simulated industrial practices. GlcCer was isolated from the samples by solvent
extraction, solvent partition, and TLC and was quantified by HPLC. GlcCer remained mostly within the defatted soy flakes (91%)
rather than in the oil (9%) after oil extraction. Only 52, 42, and 26% of GlcCer from defatted soy flakes was recovered in
the acid-washed SPC, alcohol-washed SPC, and SPI products, respectively. All protein products had a similar GlcCer concentration
of about 281 nmol/g (dry wt basis). The minor quantity of GlcCer in the crude oil was almost completely removed by water degumming. 相似文献
40.
Riccardo Carli Raymond Le Van Mao Claudia L. Blanchi Vittorio Ragaini 《Catalysis Letters》1993,21(3-4):265-274
Gallium species which were incorporated initially in the oxide form, were all in the (+3) oxidation state in the hybrid catalyst and exhibited two types of hydrogen chemisorption sites, shw and shs. The stronger sorption sites shs which predominated at higher gallium dispersion, corresponded probably to the most effective surface configuration for gallium in the aromatization ofn-butane. 相似文献