Adsorption of Cr(VI) from aqueous solution by hydrous zirconium oxide

A type of ZrO(2)center dot nH(2)O Was synthesized and its Cr(VI) removal potential was investigated in this study. The kinetic study, adsorption isotherm, pH effect, thermodynamic study and desorption were examined in batch experiments. The kinetic process was described by a pseudo-second-order rate model very well. The Cr(VI) adsorption tended to increase with a decrease of pH. The adsorption data fitted well to the Langmuir model. The adsorption capacity increased from 61 to 66 mg g(-1) when the temperature was increased from 298 to 338 K. The positive values of both Delta H degrees and Delta S degrees suggest an endothermic reaction and increase in randomness at the solid-liquid interface during the adsorption. Delta G degrees values obtained were negative indicating a spontaneous adsorption process. The effective desorption of Cr(VI) on ZrO(2)center dot nH(2)O could be achieved using distilled water at pH 12. (C) 2009 Elsevier B.V. All rights reserved.

Reliability and validity of the Impact of Event Scale (IES): version for Brazilian burn victims

Aims. The aims of this study were to assess the internal reliability (internal consistency), construct validity, sensitivity and ceiling and floor effects of the Brazilian-Portuguese version of the Impact of Event Scale (IES). Design. Methodological research design. Method. The Brazilian-Portuguese version of the IES was applied to a group of 91 burned patients at three times: the first week after the burn injury (time one), between the fourth and the sixth months (time two) and between the ninth and the 12th months (time three). The internal consistency, construct validity (convergent and dimensionality), sensitivity and ceiling and floor effects were tested. Results. Cronbach`s alpha coefficients showed high internal consistency for the total scale (0 center dot 87) and for the domains intrusive thoughts (0 center dot 87) and avoidance responses (0 center dot 76). During the hospitalisation (time one), the scale showed low and positive correlations with pain measures immediately before (r = 0 center dot 22; p < 0 center dot 05) and immediately after baths and dressings (r = 0 center dot 21; p < 0 center dot 05). After the discharge, we found strong and negative correlations with self-esteem (r = -0 center dot 52; p < 0 center dot 01), strong and positive with depression (r = 0 center dot 63; p < 0 center dot 01) and low and negative with the Bodily pain (r = -0 center dot 24; p < 0 center dot 05), Social functioning (r = -0 center dot 34; p < 0 center dot 01) and Mental health (r = -0 center dot 27; p < 0 center dot 05) domains of the SF-36 at time two. Regarding the sensitivity, no statistically significant differences were observed between mean scale scores according to burned body surface (p = 0 center dot 21). The floor effect was observed in most of the IES items. Conclusion. The adapted version of the scale showed to be reliable and valid to assess postburn reactions on the impact of the event in the group of patients under analysis. Relevance to clinical practice. The Impact of Event Scale can be used in research and clinical practice to assess nursing interventions aimed at decreasing stress during rehabilitation.

Sorption aspects for unconsolidated materials of the Sao Carlos region (SP), Brazil

The transport of liquid and gaseous pollutants through porous geological media depends on the physical and chemical characteristics of the unconsolidated material, rocks and water associated with the characteristics of the pollutants. Of these characteristics, the sorption aspect is of fundamental importance and is a function of the mineral proportions, pH, Eh and void aspects encountered in the porous media. In the Sao Carlos region, located in the eastern-central part of the 9 ate of Sao Paulo, Brazil, there are basically two types of unconsolidated materials: the first is a residual from sandstones cemented with fines and the secondarily composed of claystones, siltstones and conglomerates from the Cretaceous Period that constitute the Itaqueri Formation; the second is a sandy sediment of the Tertiary Period. These geological conditions are found in areas where chemical products are disposed of characterized as either diffuse or point pollutions sources. Because of this situation, a study was developed to evaluate the sorption aspects of some inorganic cations that are frequently found in these sources, in varied concentrations. Taken into consideration were their physical/chemical properties, such as: specific weight, grain size, mineralogy, cationic exchange capacity, pH, hydraulic conductivity. Batch tests were run using solutions of KCl, ZnCl(2) and CuCl center dot H(2)O at three different pH values, and then with a combined solution (KCl + ZnCl(2) + CuCl center dot H(2)O), also at three different pH values.

Porous alumina-spinel ceramics for high temperature applications

In order to reduce energy costs, high-temperature insulation porous refractory ceramics have been subjected to increasing demands. Among the techniques used to produce these materials (such as the addition of foaming agents and organic compounds), the pore generation via phase transformation presents key aspects, such as easy processing and the absence of toxic volatiles. In this study, this technique was applied to produce porous ceramics by decomposing an aluminum magnesium hydro-carbonate known as hydrotalcite (Mg(6)Al(2)(CO(3))(OH)(16)center dot 4H(2)O). It was found out that by using this complex compound, a large fraction of pores can be generated and kept at high temperatures (above 1300 degrees C) due to the in situ formation of spinel-like phases (MgAl(2)O(4)). (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

Thermally activated peroxydisulfate in the presence of additives: A clean method for the degradation of pollutants

The kinetics and mechanism of the thermal activation of peroxydisulfate, in the temperature range from 60 to 80 degrees C, was investigated in the presence and absence of sodium formate as an additive to turn the oxidizing capacity of the reaction mixture into a reductive one. Trichloroacetic acid, TCA, whose degradation by a reductive mechanism is well reported in the literature, was used as a probe. The chemistry of thermally activated peroxydisulfate is described by a reaction scheme involving free radical generation. The proposed mechanism is evaluated by a computer simulation of the concentration profiles obtained under different experimental conditions. In the presence of formate, SO(4)(center dot-) radicals yield CO(2)(center dot-), which are the main species available for degrading TCA. Under the latter conditions, TCA is more efficiently depleted than in the absence of formate, but otherwise identical conditions of temperature and [S(2)O(8)(2-)]. We therefore conclude that activated peroxydisulfate in the presence of formate as an additive is a convenient method for the mineralization of substrates that are refractory to oxidation. such as perchlorinated hydrocarbons and TCA. This method has the advantage that leaves no toxic residues. (C) 2009 Elsevier Ltd. All rights reserved.

Meat quality of broilers from different rearing systems

Color, pH, shear force, water-holding capacity, chemical composition, cholesterol content, and fatty acid profile from conventional, free-range and alternative broiler breast meat were determined in order to evaluate differences in the quality of broiler meat produced under different systems. Broilers reared in a conventional system had the highest lipid content (1.3%) but lower proportions of polyunsaturated (17.3%) and omega-3 fatty acids (0.3%) (p<0.05) compared to free-range and alternative broilers. On the other hand, free-range broilers had a lower cholesterol content (48.6 mg center dot 100 g(-1)) and lower pH (5.7 1) while broilers raised in an alternative system had a higher shear force (2.33 kgf) and lower yellowness value (b* value = 3.15) when compared to the other rearing systems (p<0.05).

Use of Sugar Cane Vinasse to Mitigate Aluminum Toxicity to Saccharomyces cerevisiae

Owing to its toxicity, aluminum (Al), which is one of the most abundant metals, inhibits the productivity of many cultures and affects the microbial metabolism. The aim of this work was to investigate the capacity of sugar cane vinasse to mitigate the adverse effects of Al on cell growth, viability, and budding, as the likely result of possible chelating action. For this purpose, Fleischmann`s yeast (Saccharomyces cerevisiae) was used in growth tests performed in 125-mL Erlenmeyer flasks containing 30 mL of YED medium (5.0 g/L yeast extract plus 20 g/L glucose) supplemented with the selected amounts of either vinasse or Al in the form of AlCl(3) center dot A H(2)O. Without vinasse, the addition of increasing levels of Al up to 54 mg/L reduced the specific growth rate by 18%, whereas no significant reduction was observed in its presence. The toxic effect of Al on S. cerevisiae growth and the mitigating effect of sugar cane vinasse were quantified by the exponential model of Ciftci et al. (Biotechnol Bioeng 25:2007-2023, 1983). The cell viability decreased from 97.7% at the start to 84.0% at the end of runs without vinasse and to 92.3% with vinasse. On the other hand, the cell budding increased from 7.62% at the start to 8.84% at the end of runs without vinasse and to 17.8% with vinasse. These results demonstrate the ability of this raw material to stimulate cell growth and mitigate the toxic effect of Al.

Annual and polyetic progression of citrus canker on trees protected with copper sprays

The effects of copper sprays on annual and polyetic progress of citrus canker, caused by Xanthomonas citri subsp. citri, in the presence of the Asian citrus leafminer (Phyllocnistis citrella), were evaluated in a study conducted in a commercial orchard in northwest Parana state, Brazil, where citrus canker is endemic. Nonlinear monomolecular, logistic and Gompertz models were fitted to monthly disease incidence data (proportion of leaves with symptoms) for each treatment for three seasons. The logistic model provided the best estimate of disease progress for all years and treatments evaluated and logistic parameter estimates were used to describe polyetic disease dynamics. Although citrus canker incidence increased during each of the seasons studied, it decreased over the whole study period, more so in copper-treated trees than in water-sprayed controls. Copper treatment reduced disease incidence compared with controls in every year, especially 2004-2005, when incidence was ca. 10-fold higher in controls than in treated plots (estimated asymptote values 0 center dot 82 and 0 center dot 07, respectively). Copper treatment also reduced estimated initial disease incidence and epidemic growth rates every year.

Liberibacters associated with orange jasmine in Brazil: incidence in urban areas and relatedness to citrus liberibacters

Two surveys (2005/2006 and 2009) were conducted in the state of Sao Paulo, Brazil, to investigate the incidence of `Candidatus Liberibacter asiaticus` and `Ca. L. americanus`, two liberibacters associated with citrus huanglongbing (HLB) disease and both transmitted by Diaphorina citri, in orange jasmine (Murraya exotica), a widespread ornamental tree in cities and villages. The graft-transmissibility of the two species, and their DNA relatedness to citrus-associated liberibacters, were also investigated. Quantitative PCR was applied to PCR-positive orange jasmine and HLB-positive citrus growing in backyards and orchards to assess their inoculum source potentials. Liberibacters were detected in 91 of 786 sampled orange jasmine plants in 10 of 76 sampled locations. PCR-positive trees exhibited yellow shoots and/or dieback symptoms indistinguishable from those on PCR-negative trees. `Candidatus Liberibacter americanus` was more common in 2005/2006 (96 center dot 6%) and `Ca. L. asiaticus` in 2009 (84 center dot 8%). rplJ nucleotide sequences were identical within all populations of either species. Graft transmission succeeded only in homologous host combinations, including `Ca. L. americanus` (2/10) from/to orange jasmine and `Ca. L. americanus` (5/18) and `Ca. L. asiaticus` (5/9) from/to citrus. Symptoms were mild and developed less rapidly in orange jasmine than in citrus, probably as a result of lower liberibacter multiplication rates. Respective titres of `Ca. L. americanus` and `Ca. L. asiaticus` in orange jasmine averaged 4 center dot 3 and 3 center dot 0 log cells g-1 tissue, compared with 5 center dot 5 and 7 center dot 3 in citrus. The results indicate that orange jasmine does not favour liberibacter multiplication as much as citrus. However, its importance in HLB epidemics should not be underestimated as it is a preferred host of D. citri and is not under any strict tree-eradication programme or measures for insect control.

Nitrogen and Sulfur Fertilization and Dynamics in a Brazilian Entisol under Pasture

Nutrient dynamics in tropical soils sustaining forage grasses are still poorly understood. We conducted a study to evaluate the effect of combined N and S fertilizer rates on the growth of `Marandu` palisade grass [Brachiaria brizantha (Hochst. ex A. Rich.) Stapf], uptake of these elements from the soil by plants, soil organic matter concentration, soil pH, and the mineral and organic fractions of N and S in an Entisol. Combinations of five N rates (0, 100, 200, 300, and 400 g N m(-3)) with five S rates (0, 10, 20, 30, and 40 g S m(-3)) were evaluated in a partial 5 x 5 factorial in a pot experiment, with and without plants. Nitrogen and S were supplied as NH(4)NO(3) and CaSO(4)center dot 2H(2)O, respectively. The N addition in excess did not enhance the palisade grass production due to low plant-available Sin the soil. The supply of low rates of S with N greatly improved the overall N uptake efficiency by the forage plant. The contents of total N, NO(3)(-)-N, and NH(4)(+)-N in the soil varied with N rate and with N uptake by the plants. The association of palisade grass with S fertilization increased the ester-bonded S fraction in the soil. The results suggest that soil residual S could be a potential source of S for plants. Proper N and S fertilizer rates promoted increased grass production due to increased uptake of these nutrients and the dynamics of the organic N and S fractions and mineral fractions in this tropical soil.

Potential beneficial properties of bacteriocin-producing lactic acid bacteria isolated from smoked salmon

Aims: To evaluate the probiotic properties of strains isolated from smoked salmon and previously identified as bacteriocin producers. Methods and Results: Strains Lactobacillus curvatus ET06, ET30 and ET31, Lactobacillus fermentum ET35, Lactobacillus delbrueckii ET32, Pediococcus acidilactici ET34 and Enterococcus faecium ET05, ET12 and ET88 survived conditions simulating the gastrointestinal tract (GIT) and produced bacteriocins active against several strains of Listeria monocytogenes, but presented very low activity against other lactic acid bacteria (LAB). Cell-free supernatants containing bacteriocins, added to 3-h-old cultures of L. monocytogenes 603, suppressed growth over 12 h. Auto-aggregation was strain-specific, and values ranged from 7 center dot 2% for ET35 to 12 center dot 1% for ET05. Various degrees of co-aggregation with L. monocytogenes 603, Lactobacillus sakei ATCC 15521 and Enterococcus faecalis ATCC 19443 were observed. Adherence of the bacteriocinogenic strains to Caco-2 cells was within the range reported for Lactobacillus rhamnosus GG, a well-known probiotic. The highest levels of hydrophobicity were recorded for Lact. curvatus (61 center dot 9-64 center dot 6%), Lact. fermentum (78 center dot 9%), Lact. delbrueckii (43 center dot 7%) and Ped. acidilactici (51 center dot 3%), which are higher than the one recorded for Lact. rhamnosus GG (53 center dot 3%). These strains were highly sensitive to several antibiotics and affected by several drugs from different generic groups in a strain-dependent manner. Conclusions: Smoked salmon is a rich source of probiotic LAB. All strains survived conditions simulating the GIT and produced bacteriocins active against various pathogens. Adherence to Caco-2 cells was within the range reported for Lact. rhamnosus GG, a well-known probiotic. In addition, the high hydrophobicity readings recorded define the strains as good probiotics. Significance and Impact of the Study: Smoked salmon contains a number of different probiotic LAB and could be marketed as having a potential beneficial effect.

Iron deficiency and frequency of HFE C282Y gene mutation in Brazilian blood donors

Limited data are available about iron deficiency (ID) in Brazilian blood donors. This study evaluated the frequencies of ID and iron-deficiency anaemia (IDA) separately and according to frequency of blood donations. The protective effect of the heterozygous genotype for HFE C282Y mutation against ID and IDA in female blood donors was also determined. Five hundred and eight blood donors were recruited at the Blood Bank of Santa Casa in Sao Paulo, Brazil. Haemoglobin and serum ferritin concentrations were measured. The genotype for HFE C282Y mutation was determined by polymerase chain reaction followed by restriction fragment length polymorphism analysis. The ID was found in 21 center dot 1% of the women and 2 center dot 6% of the men whereas the IDA was found in 6 center dot 8 and 0 center dot 3%, respectively. The ID was found in 11 center dot 9% of the women in group 1 (first-time blood donors) and the frequency increased to 38 center dot 9% in women of the group 3 (blood donors donating once or more times in the last 12 months). No ID was found in men from group 1; however the ID frequency increased to 0 center dot 9% in group 2 (who had donated blood before but not in the last 12 months) and 5 center dot 0% in group 3. In summary, the heterozygous genotype was not associated with reduction of ID or IDA frequencies in both genders, but in male blood donors it was associated with a trend to elevated ferritin levels (P = 0 center dot 060). ID is most frequent in Brazilian women but was also found in men of group 3.

Leptospiral glycolipoprotein as a candidate antigen for serodiagnosis of human leptospirosis

Aims: Development of a simple, specific, rapid and inexpensive Dot-ELISA test for early diagnosis of human leptospirosis. Methods and Results: Serum samples from 90 patients diagnosed with leptospirosis were analysed by Dot-ELISA test incorporating Glycolipoprotein (GLP) antigen from serovars Copenhageni and Patoc. Results were compared with those obtained with microscopic agglutination test, currently, the gold standard reference serological method. Serum samples from healthy blood bank donors and patients diagnosed with diseases other than leptospirosis were used as negative controls. The specificities of both GLP-based assays were 97 center dot 1% and 100% with serum samples from patients with other diseases and with serum samples from healthy control group, respectively. With serum samples from patients with acute leptospirosis, sensitivity was 76 center dot 6% with Dot-ELISA Copenhageni and 90 center dot 0% with Dot-ELISA Patoc. With serum samples from patients in convalescence, sensitivity was 100% with both GLP-based assays. Conclusions: This Dot-ELISA provides a candidate antigen for serodiagnosis of leptospirosis during all phases of illness and could be a good alternative method for the early diagnosis of leptospirosis. Significance and Impact of the Study: The Dot-ELISA test is simple, specific, rapid and inexpensive. It is suitable for identifying a large number of samples and, hence, reducing the death rate of patients with leptospirosis.

Biomarkers of oxidative stress and endothelial dysfunction in glucose intolerance and diabetes mellitus

Objectives: To evaluate biomarkers of endothelial dysfunction and oxidative stress in glucose intolerance (GI) compared to overt diabetes (DM2). Design and methods: 140 volunteers including 96 with DM2, 32 with GI and 12 controls (C) were Studied. NO metabolites, NO synthase inhibitors. thiols and N-acetyl-beta-glucosaminidase (NAGase) activity were analyzed by chemiluminescence, capillary electrophoresis, ELISA and colorimetric assay, respectively. Results: (center dot)NO metabolites were higher in GI (NOx: P=0.03 S-nitrosothiols: p=0.001) and DM2 (p=0.006; p=0.0006) groups in relation to group C, while nitrotyrosine was higher only in the DM2 group in comparison 10 the other groups. NAGase activity was elevated in GI (p=0.003) and DM2 (p=0.0004) groups in relation to group C, as well as, ADMA (p=0.01: p=0.003) and GSSG (p=0.01 p=0.002). Conclusions: (center dot)NO metabolites. (center dot)NO synthase inhibitors. thiols and NAGase are biomarkers Suitable to indicate endothelial dysfunction and oxidative stress in the early stages of impaired response to insulin. (c) 2008 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Expanding cyclitol structural diversity by biocatalysis and metalocatalysis. A click chemistry approach

The palladium catalyzed cross-coupling reaction of phenyltrifluoroborate with a chemoenzymatically derived bromoazidoconduritol, combined with 1,3-dipolar cycloaddition, with a variety of alkynes is described. Fourteen new compounds were synthesized in moderate to good yields. The click chemistry reaction can be effected by using sodium ascorbate and CuSO(4) center dot 5H(2)O as catalyst in toluene-H(2)O at room temperature.