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31.
Eliane Gonçalves Gomes João Carlos Correia Baptista Soares de Mello Geraldo da Silva e Souza Lidia Angulo Meza João Alfredo de Carvalho Mangabeira 《Annals of Operations Research》2009,169(1):167-181
The aim of this paper is to use DEA models to evaluate sustainability in agriculture. Several variables are taken into account
and the resulting efficiency is measured by comparison. The performance of family farms is analysed here (variables: farmed
area, work force, and production). As agricultural sustainability depends on the maintenance of systems of production for
long periods of time, the models were run for the years of 1986 and 2002. Tiered DEA models were used to group farmers in
sustainability categories. Non-parametric regression models were used to identify the factors affecting the efficiency measurements.
All the results indicate that the majority of the farmers increased their efficiency along the time. These improvements may
support the existence of sustainability. 相似文献
32.
Laís Peres Silva Ivanilson Pimenta Santos Dahara Keyse Carvalho Silva Bruna Padilha Zurita Claro dos Reis Cssio Santana Meira Marcos Venícius Batista de Souza Castro Jos Maurício dos Santos Filho Joo Honorato de Araujo-Neto Javier Alcides Ellena Rafael Gomes da Silveira Milena Botelho Pereira Soares 《Molecules (Basel, Switzerland)》2022,27(23)
Immunomodulatory agents are widely used for the treatment of immune-mediated diseases, but the range of side effects of the available drugs makes necessary the search for new immunomodulatory drugs. Here, we investigated the immunomodulatory activity of new ferrocenyl-N-acyl hydrazones derivatives (SintMed(141–156). The evaluated N-acyl hydrazones did not show cytotoxicity at the tested concentrations, presenting CC50 values greater than 50 µM. In addition, all ferrocenyl-N-acyl hydrazones modulated nitrite production in immortalized macrophages, showing inhibition values between 14.4% and 74.2%. By presenting a better activity profile, the ferrocenyl-N-acyl hydrazones SintMed149 and SintMed150 also had their cytotoxicity and anti-inflammatory effect evaluated in cultures of peritoneal macrophages. The molecules were not cytotoxic at any of the concentrations tested in peritoneal macrophages and were able to significantly reduce (p < 0.05) the production of nitrite, TNF-α, and IL-1β. Interestingly, both molecules significantly reduced the production of IL-2 and IFN-γ in cultured splenocytes activated with concanavalin A. Moreover, SintMed150 did not show signs of acute toxicity in animals treated with 50 or 100 mg/kg. Finally, we observed that ferrocenyl-N-acyl hydrazone SintMed150 at 100 mg/kg reduced the migration of neutrophils (44.6%) in an acute peritonitis model and increased animal survival by 20% in an LPS-induced endotoxic shock model. These findings suggest that such compounds have therapeutic potential to be used to treat diseases of inflammatory origin. 相似文献
33.
Fernando P. Carvalho Jean-Pierre Villeneuve Chantal Cattini 《Trends in analytical chemistry : TRAC》1999,18(11):1005-664
A seaweed sample (Fucus sp.) was prepared, homogenised and distributed to laboratories worldwide as the IAEA-140 intercomparison material for the analysis of organochlorine compounds and petroleum hydrocarbons. A total of 80 laboratories from 51 countries reported results for this sample. The data sets reported by laboratories were evaluated statistically and the mean concentration values could be computed with 95% confidence limits for a large number of analytes. The accuracy of the analytical performance of each laboratory has been introduced by using Z-scores. The spread of results reported generally indicates that the accurate determination of many persistent organic pollutants, such as hexachlorobenzene, lindane, Aroclors or fluoranthene, is still difficult for many laboratories. The final results of this intercomparison exercise enable individual participants to assess their performance and, where necessary, to introduce appropriate modifications in their analytical procedures. Furthermore, as a series of statistical criteria was fulfilled for a number of compounds, the sample IAEA-140 can now be used as a reference material for quality control in the determination of chlorinated compounds and petroleum hydrocarbons in environmental samples. 相似文献
34.
Pereira C Patrício S Silva AR Magalhães AL Carvalho AP Pires J Freire C 《Journal of colloid and interface science》2007,316(2):570-579
Copper (II) acetylacetonate was immobilised directly onto two clays, laponite (Lap) and K10-montmorillonite (K10), and after their amine functionalisation with (3-aminopropyl)triethoxysilane (APTES). All the materials were characterised by nitrogen adsorption isotherms at -196 degrees C, elemental analysis, TG-DSC, XRD, and IR spectroscopy. The K10-based materials were also characterised by XPS. The APTES-functionalised K10 showed higher copper loading than K10, indicating that the clay functionalisation enhanced the complex immobilisation; on the contrary, in Lap-based materials higher metal content was obtained by direct complex anchoring, probably due to the delaminated nature of Lap which induced the particles aggregation on functionalisation with APTES. All the results pointed out that the Cu complex was anchored onto the amine-functionalised clays by Schiff condensation between the amine groups of anchored APTES and the carbonyl groups of the acetylacetonate ligand, whereas direct immobilisation proceeded mostly through interaction between the metal centre and the clay surface hydroxyl groups. 相似文献
35.
Celso Santi Junior Adriane Maria Ferreira Milagres André Ferraz Walter Carvalho 《Cellulose (London, England)》2013,20(6):3165-3177
The porosity of lignocellulosic materials is a key feature for the enzymatic hydrolysis of the constituent polysaccharides, being affected by its drying and lignin content. Here we evaluated the influence of both parameters in the porosity of sugarcane bagasse, using raw and chlorite-delignified samples. A fraction of these samples was air dried at room temperature and the remainder one was kept wet. All the samples were subjected to porometry (solute exclusion technique), determination of water retention value and assessment of enzymatic saccharification of polysaccharides. Samples with higher lignin contents had lower porosities and exhibited worse enzymatic conversions of polysaccharides. Mild drying collapsed only the smaller pores, which already were inaccessible to enzymes, and therefore did not affect the efficiencies of saccharification. Our results show that the lignin content plays an important role in the porosity of the material and that its removal improves the enzymatic saccharification of the constituent polysaccharides. 相似文献
36.
37.
Vivian?Regina?Trist?o Fernando?Felippe?de?Carvalho Cinthia?Zanini?Gomes Adriana?Regina?Miranda Cíntia?C.?Vequi-Suplicy Maria?Teresa?Lamy Nestor?Schor Maria?Helena?Bellini 《Journal of fluorescence》2010,20(3):665-669
The progression to end-stage renal failure is independent of the initial pathogenic mechanism. Metabolic acidosis is a common consequence of chronic renal failure that results from inadequate ammonium excretion and decreased tubular bicarbonate reabsorption. Protoporphyrin IX (PpIX) is the immediate metabolic precursor of the heme molecule. The purpose of this study was to evaluate the levels of erythrocytes protoporphyrin IX at an animal model during progressive renal disease. A total of 36 eight-week-old male Wistar rats were divided into six groups: Normal, 4 and 8 weeks after 5/6 nephrectomy (NX). Renal function was evaluated by creatinine clearance and plasma creatinine levels. The autofluorescence of erythrocytes porphyrin of healthy and NX rats was analyzed using fluorescence spectroscopy. Emission spectra were obtained by exciting the samples at 405 nm. Significant differences between normal and NX rats autofluorescence shape occurred in the 600–700 nm spectral region. A correlation was observed between emission band intensity at 635 nm and progression of renal disease. 相似文献
38.
39.
Sofia Pessanha Maria Luisa Carvalho Maria Becker Alex von Bohlen 《Spectrochimica Acta Part B: Atomic Spectroscopy》2010
The purpose of this study is to determine the elemental content, namely heavy metals, of samples of vine-leaves, grapes must and wine. In order to assess the influence of the vineyard age on the elemental content throughout the several stages of wine production, elemental determinations of trace elements were made on products obtained from two vineyards aged 6 and 14 years from Douro region. The elemental content of vine-leaves and grapes was determined by Energy Dispersive X-Ray Fluorescence (EDXRF), while analysis of the must and wine was performed by Total Reflection X-ray Fluorescence (TXRF). 相似文献
40.
Sorption and desorption of molybdenum in alumina microspheres 总被引:4,自引:0,他引:4
The behavior of minor amount of molybdenum(VI) in the presence of large quantity of aluminum nitrate and separation of Mo(VI) from Al(III) with the aid of a chromatographic process onto an alumina column has been studied. The separation of both elements is in favor of the selective uptake of molybdenum by the alumina. The solution containing both elements is an acidified aluminum nitrate of high concentration in aluminum. The work envisage a future separation and purification of radiomolybdenum for the milking of tecnetium-99m. 相似文献