Maternal Th17 Profile after Zika Virus Infection Is Involved in Congenital Zika Syndrome Development in Children.

Brazil is one of the countries that experienced an epidemic of microcephaly and other congenital manifestations related to maternal Zika virus infection which can result in Congenital Zika Syndrome (CZS). Since the Zika virus can modulate the immune system, studying mothers' and children's immune profiles become essential to better understanding CZS development. Therefore, we investigated the lymphocyte population profile of children who developed CZS and their mothers' immune response in this study. The study groups were formed from the Plaque Reduction Neutralization Test (PRNT) (CZS+ group) result. To evaluate the lymphocyte population profile, we performed phenotyping of peripheral lymphocytes and quantification of serum cytokine levels. The immunophenotyping and cytokine profile was correlated between CSZ+ children and their mothers. Both groups exhibited increased interleukin-17 levels and a reduction in the subpopulation of CD4+ T lymphocytes. In contrast, the maternal group showed a reduction in the population of B lymphocytes. Thus, the development of CZS is related to the presence of an inflammatory immune profile in children and their mothers characterized by Th17 activation.

Comparison and convergent validity of five Mediterranean dietary indexes applied to Brazilian adults and older adults: data from a population-based study (2015 ISA-Nutrition).

Different dietary indexes are proposed to investigate adherence to the Mediterranean diet (MD). However, they are based on different methodologies, and limited research has compared them to each other, particularly in non-Mediterranean populations. We aimed to compare five indexes intended to measure adherence to the MD. The sample was composed of adults and older adults (n 1187) from 2015 ISA-Nutrition, a cross-sectional population-based study in São Paulo, SP, Brazil. Dietary data obtained through two 24-h dietary recalls (24HDR) from which the Mediterranean diet scale (MDS), Mediterranean diet Score (MedDietscore), Mediterranean dietary pattern (MDP), Mediterranean Adequacy Index (MAI) and Mediterranean-Style Dietary Pattern Score (MSDPS) were calculated. The correlations and agreements between them were analysed by Spearman's correlation and linearly weighted Cohen's Kappa coefficients, respectively. Confirmatory factor analyses (CFAs) were applied to investigate their convergent validity. The highest correlations were found between MDP and MAI (r = 0⋅76; 95% CI 0⋅74-0⋅79) and between MDP and MDS (r = 0⋅72; 95% CI 0⋅69-0⋅75). The greatest agreements observed were moderate, between MDP v. MAI (κ = 0⋅57, P < 0⋅001) and MDP v. MDS (κ = 0⋅48, P < 0⋅001). The goodness-of-fit of CFA for MedDietscore (RMSEA = 0⋅033, 90% CI 0⋅02-0⋅042; SRMR = 0⋅042) and MSDPS (RMSEA = 0⋅028, 90% CI 0⋅019-0⋅037; SRMR = 0⋅031) had acceptable values for absolute fit indices. Vegetables, olive oil, MUFA:SFA ratio and cereals with legumes were more relevant to characterise the MD (factor loadings ≥0⋅50). The MDS, MAI and MDP classified the population similarly, but the MedDietscore showed better performances in evaluating adherence to the MD. These results provided guidance for the most appropriate Mediterranean dietary index to be applied in non-Mediterranean populations.

Maternal Immune Response to ZIKV Triggers High-Inflammatory Profile in Congenital Zika Syndrome.

The immunological mechanisms involved in the development of congenital Zika syndrome (CZS) have yet to be fully clarified. This study aims to assess the immuno-inflammatory profile of mothers and their children who have been diagnosed with CZS. Blood samples, which were confirmed clinically using the plaque reduction neutralization test (PRNT), were collected from children with CZS and their mothers (CZS+ group). Samples were also collected from children who did not develop CZS and had a negative PRNT result and from their mothers (CZS- group). The data demonstrated a correlation between the leukocyte profile of CZS+ children and their mothers, more evident in monocytes. Monocytes from mothers of CZS+ children showed low expression of HLA and elevated hydrogen peroxide production. CZS+ children presented standard HLA expression and a higher hydrogen peroxide concentration than CZS- children. Monocyte superoxide dismutase activity remained functional. Moreover, when assessing the monocyte polarization, it was observed that there was no difference in nitrite concentrations; however, there was a decrease in arginase activity in CZS+ children. These data suggest that ZIKV infection induces a maternal immuno-inflammatory background related to the child's inflammatory response after birth, possibly affecting the development and progression of congenital Zika syndrome.

Dietary pattern changes, obesity and excess body fat in adults of a Brazilian birth cohort.

BACKGROUND: Few studies have assessed dietary patterns (DPs) and the changes in these patterns over time in adults. The present study aimed to investigate whether possible changes in DPs in two assessments are associated with obesity and excess body fat. METHODS: A prospective study was conducted in which data were collected from 1082 adults of a Brazilian birth cohort during two periods 15 years apart (T1: 2002-2004; T2: 2016-2017). Food consumption was assessed in both periods using validated food frequency questionnaires. Three similar DPs were found in the two assessments, and adherence to these patterns was classified as prudent, risk or mixed. Nine DPs changes were defined. At T2, subjects with a body mass index ≥ 30.0 kg m- ² were classified as obese, and men and women with a body fat (BF) percentage ≥ 25.0 and ≥ 35.0, respectively, were classified as having excess BF. A directed acyclic graph was built to adjust the association for confounding variables. RESULTS: At T2, 34.4% of the subjects were obese and 61.4% had excess BF. In the adjusted analysis, the changes associated with obesity and excess BF were prudent-mixed (prevalence ratio [PR] 1.55; 95% confidence interval [CI] = 1.04-2.29 and PR = 1.35; 95% CI = 1.10-1.65), risk-risk (PR = 1.49; 95% CI = 1.03-2.13 and PR = 1.27; 95% CI = 1.04-1.53), risk-mixed (PR = 1.56; 95% CI = 1.05-2.31 and PR = 1.33; 95% CI = 1.07-1.63) and mixed-risk (PR = 1.61; 95% CI = 1.10-2.35 and PR = 1.29; 95% CI = 1.04-1.58). CONCLUSIONS: A decline in food quality over time or stagnation in an unhealthy DP can lead to obesity and excess BF.

Passive Attenuation of Mechanical Vibrations with a Superelastic SMA Bending Springs: An Experimental Investigation.

This work presents an experimental study related to the mechanical performance of a special design spring fabricated with a superelastic shape memory alloy (SMA-SE). For the experimental testing, the spring was coupled in a rotor machine, aiming to attenuate the mechanical vibration when the system went through a natural frequency without any external power source. It was verified that the reduction in instabilities stemmed from the better distribution of vibration force in the proposed device, as well as the damping capacity of the spring material. These findings showed that the application of the M-Shape device of SMA-SE for three different cases could reduce vibration up to 23 dB when compared to the situations without, and with, 1.5 mm of preload. The M-Shape device was shown to be efficient in reducing the mechanical vibration in a rotor system. This was due to the damping capacity of the SMA-SE material, and because the application did not require any external source of energy to generate phase transformation.

Phytotoxic property of metabolites isolated from Garcinia gardneriana.

Garcinia gardneriana is a medicinal tree species used in Brazil in the treatment of hepatitis and gastritis. This use is attributed to phenolic compounds, mainly 7-epiclusianone, guttiferone-A and fukugetin, which present several proven biological activities. However, to the best of our knowledge, no study on the phytotoxic activity of G. gardneriana extracts has been conducted until now. This research proposed to isolate and quantify by high-performance liquid chromatography (HPLC) the major compounds from G. gardneriana seed extracts in ethyl acetate and to evaluate their phytotoxic activities. The natural products 7-epiclusianone, guttiferone-A and fukugetin were quantified at concentrations varying from 0.46 to 1.13 mg mL-1 and were isolated with yields ranging from 7% to 23% (w/w). The phytotoxic assay indicated that the crude extract showed no action on the dry matter of Sorghum bicolor plants, but the isolated compounds fukugetin and 7-epiclusianone had moderate activity. On the other hand, guttiferone-A displayed a greater herbicide activity than glyphosate, a positive control, even in almost three times lower concentrations, causing severe intoxication in the plants. This work is the first report on this activity by the extract of G. gardneriana and its isolated compounds. Besides that, guttiferone-A showed up as a scaffold for the development of new agrochemicals. Complementing these findings, computational studies suggested that this benzophenone can interact effectively with transferase enzymes type, in special caffeic acid O-methyltransferase from S. bicolor (PDB code: 4PGH), indicating a possible mechanism of action in this plant.

Higher sugar intake is associated with periodontal disease in adolescents.

OBJECTIVES: Analyze the association between higher added sugar exposure and periodontal disease in adolescents (18-19 years old). MATERIALS AND METHODS: This was a cross-sectional study nested to RPS Cohorts Consortium, São Luís, Brazil (n = 2515). The exposure was percentage of daily calories from added sugar (≥ 10%), estimated from a quantitative food frequency. The outcome was periodontal disease estimated by the number of teeth affected by bleeding on probing, periodontal probing depth ≥ 4 mm, and clinical attachment level ≥ 4 mm at the same site. A theoretical model was depicted in a directed acyclic graph to identify the minimal sufficient adjustment set: household income, adolescent's educational level, sex, alcohol use, and smoking. Periodontal disease was categorized into < 2 teeth affected, 2 to 3 teeth affected, and ≥ 4 teeth affected to estimate prevalence ratios (PR) by multinomial logistic regression. To test for consistency, means ratio (MR) were estimated using zero-inflated Poisson. RESULTS: High sugar intake was associated with ≥ 4 teeth affected by periodontal disease (PR = 1.42; 95% confidence interval (CI) = 1.03-1.94; p = 0.030); consistency Poisson analysis reinforced these results (MR = 1.15; 95% CI = 1.03-1.29; p = 0.011). CONCLUSION: High level of added sugar intake was associated with greater extent of periodontal disease in adolescents. CLINICAL RELEVANCE: High sugar intake was associated with periodontal disease in adolescents, supporting the integrated hypothesis of dental caries and periodontal disease and giving impetus to future clinical investigation on the effect of restriction of added sugar consumption in periodontal parameters, which potentially may change traditional treatment protocols of periodontal disease.

Plaque Reduction Neutralization Test (PRNT) in the Congenital Zika Syndrome: Positivity and Associations with Laboratory, Clinical, and Imaging Characteristics.

The short duration of viremia, low blood viral load, inaccessibility to timely specific diagnostic tests, and cross-reactions with other flaviviruses have hindered laboratory confirmation of Congenital Zika Syndrome (CZS). This study analyzes the positivity of the plaque reduction neutralization test (PRNT) in children with clinical or imaging characteristics of CZS and its association with laboratory, clinical, and imaging characteristics. The 94 clinical cases of CZS submitted to the ZIKV PRNT90 test were followed from 2016 to 2018. The mean age of children at PRNT90 collection was 22 ± 6 months Standard Deviation. The ZIKV PRNT90 was positive (titer ≥ 10) in 40 (42.5%) children. ZIKV PRNT90 positivity was associated with severe microcephaly in newborns (p = 0.016), lower head circumference z-score at birth (p = 0.043) and 24 months of age (p = 0.031), and severe reduction of the cerebral parenchyma volume (p = 0.021), expressing greater disease severity. Negative PRNT90 in children with characteristic signs of CZS may be due to false-negative results, indicating that the diagnosis of CZS should be primarily syndromic.

Author Correction: Changes in Infant and Neonatal Mortality and Associated Factors in Eight Cohorts from Three Brazilian Cities.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Changes in Infant and Neonatal Mortality and Associated Factors in Eight Cohorts from Three Brazilian Cities.

Stillbirth (SBR), perinatal (PMR), neonatal (NMR) and infant mortality rates (IMR) are declining in Brazil and the factors associated with these falls are still being investigated. The objective of the present study was to assess changes in SBR, PMR, NMR and IMR over time and to determine the factors associated with changes in NMR and IMR in eight Brazilian cohorts. All cohorts are population-based (Ribeirão Preto in 1978/79, 1994 and 2010; Pelotas in 1982, 1993 and 2004; and São Luís in 1997/98 and 2010). Were included data on 41440 children. All indicators were decreased, except in the city of Pelotas, from 1993 to 2004, and except SBR in São Luís. Sociodemographic variables seem to be able to explain reductions of NMR and IMR in Ribeirão Preto, from 1978/79 to 1994, and in São Luís. In Ribeirão Preto, from 1994 to 2010 declines in NMR and IMR seem to be explained by reductions in intrauterine growth restriction (IUGR). Newborn's gestational age had diminished in all cohorts, preventing even greater reductions of NMR and IMR. Improved sociodemographic variables and reduction of IUGR, seem to be able to explain part of the decrease observed. NMR and IMR could have been reduced even more, were it not for the worsening in gestational age distribution.

Does height catch-up in schoolchildren have an effect on bone mass in adolescents? Analysis in a Brazilian birth cohort / Catch-up de estatura em escolares tem efeito sobre massa óssea em adolescentes? Análise em uma coorte brasileira de nascimento

Abstract Objective: To analyze the effect of height catch-up at school age on the bone mass of adolescents of a Brazilian birth cohort. Methods: A cohort study using data obtained from the three moments (birth, 7/9 years and 18/19 years of age) of the Cohorts-RPS study. Height catch-up was defined based on the difference between the schoolchild's z-score and birth z-score. The adolescents' bone mineral mass was analyzed using the z-score index for the lumbar spine measured by dual emission X-ray absorptiometry. A theoretical model was developed for the proposed analysis using directed acyclic graphs paired through the nearest-neighbor matching propensity score using the STATA software, version 14.0. The level of significance was set at 5%. Results: Of the 297 studied children, 24.5% achieved height catch-up. The bone mass below the expected for age was observed in 5.39% of the subjects. The mean lumbar spine z-score was −0.34 (±1.01). After the adjustment, no effect was observed between height catch-up at school age and bone mass in adolescents (Coeff = 0.598; 95% CI −0.117 to 1.313; p = 0.101). Conclusion: Even using the directed acyclic graphs and the causal inference method by adjusting the propensity score, the height catch-up did not seem to affect bone mass in adolescents, a result perhaps related to the sample size.

Resumo: Objetivo: Analisar o efeito do catch-up de estatura na idade escolar na massa óssea em adolescentes em uma coorte brasileira de nascimento. Métodos: Estudo de coorte, utilizando dados dos três momentos (nascimento, aos 7/9 anos e 18/19 anos) da pesquisa Coortes-RPS. Catch-up de estatura foi definida a partir da diferença entre o Z-score do escolar e Z-score do nascimento. Para a análise da massa óssea em adolescentes foi utilizado o índice Z-score da coluna lombar medido pela densitometria por dupla emissão de raio X. Para análise proposta, foi construído modelo teórico usando os gráficos acíclicos direcionados e pareado por escore de propensão do tipo vizinho mais próximo utilizando o software STATA versão 14.0. O nível de significância adotado foi de 5%. Resultados: Das 297 crianças, 24,58% realizaram o catch-up estatural. Massa óssea abaixo do esperado para a idade foi de 5,39%. O Z-score médio da coluna lombar foi −0,34 (± 1,01). Após ajuste, não foi observado efeito entre catch-up de estatura na idade escolar e massa óssea no adolescente (Coef = 0,598; IC 95% −0,117-1,313; p = 0,101). Conclusão: Mesmo com os gráficos acíclicos direcionados e o método de inferência causal por ajuste do escore de propensão, o catch-up de estatura parece não afetar a massa óssea em adolescentes, resultado talvez relacionado ao tamanho da amostra.

Does height catch-up in schoolchildren have an effect on bone mass in adolescents? Analysis in a Brazilian birth cohort.

OBJECTIVE: To analyze the effect of height catch-up at school age on the bone mass of adolescents of a Brazilian birth cohort. METHODS: A cohort study using data obtained from the three moments (birth, 7/9 years and 18/19 years of age) of the Cohorts-RPS study. Height catch-up was defined based on the difference between the schoolchild's z-score and birth z-score. The adolescents' bone mineral mass was analyzed using the z-score index for the lumbar spine measured by dual emission X-ray absorptiometry. A theoretical model was developed for the proposed analysis using directed acyclic graphs paired through the nearest-neighbor matching propensity score using the STATA software, version 14.0. The level of significance was set at 5%. RESULTS: Of the 297 studied children, 24.5% achieved height catch-up. The bone mass below the expected for age was observed in 5.39% of the subjects. The mean lumbar spine z-score was -0.34 (±1.01). After the adjustment, no effect was observed between height catch-up at school age and bone mass in adolescents (Coeff=0.598; 95% CI -0.117 to 1.313; p=0.101). CONCLUSION: Even using the directed acyclic graphs and the causal inference method by adjusting the propensity score, the height catch-up did not seem to affect bone mass in adolescents, a result perhaps related to the sample size.

Stress Intensity Factor of Semielliptical Surface Crack in Internally Pressurized Hollow Cylinder-A Comparison between BS 7910 and API 579/ASME FFS-1 Solutions.

The purpose of this research is to compare both British standard BS 7910 (2013) and American standard API 579/ASME FFS-1 (2016) stress intensity factor (SIF) solutions by considering a series of semielliptical surface cracks located in the external surface of a pressurized hollow cylinder in the axial direction. Finite element analysis was used as a comparison basis for both standards' SIF results. The solution from the British standard provided consistent results compared to Finite Element (FE) results for crack depth not much higher than half the thickness in the deepest and surface-breaking points. Above those limits, the British standard's solutions diverged quite a lot from the American standard, whose results followed FE values for every crack depth/thickness ratio tested with a maximum percentage difference of 1.83%.

Alcohol use and associated factors among physicians and nurses in northeast Brazil.

The consequences of alcohol use are closely related to its pattern of intake. The aim of this study is to analyze the pattern of alcohol use by doctors and nurses. Associated co-factors have also been considered. We calculated a representative sample of doctors and nurses from two hospitals in Maranhão, Northeastern Brazil. The Alcohol Use Disorders Identification Test (AUDIT) was employed to assess patterns of alcohol consumption. A score ≥8 was defined as alcohol misuse, and an answer to question number 3 > 1 was indicative of heavy episodic drinking (HED). In order to identify factors associated with HED and alcohol misuse, bivariate and multiple logistic regression analyses were performed with SPSS v20.0. A sample of 510 professionals was examined and 25% of those were abstainers; among those who had drinks containing alcohol, 86% were classified as low-risk alcohol use, scoring lower than 8, while 10.6% of the whole sample was categorized as alcohol misusers, scoring more than 8. The habit of smoking (OR = 6.02; CI: 1.71-21.16), following the Catholic religion (OR = 3.55; CI: 2.47-8.58), and also gender (OR = 3.09; CI: 1.68-5.71) were independently associated with alcohol misuse. HED was found in 14.3%. Younger age (OR = 0.96; CI: 0.92-0.98), male gender (OR = 5.13; CI: 2.55-10.30), the Catholic religion (OR = 3.22; CI: 1.44-7.21), and smoking habits (OR = 5.25; CI: 1.26-21.75) were associated with HED. Therefore, physicians and nurses have a lesser prevalence of abstainers, similar rates of alcohol misuse, and greater prevalence of HED when compared to the general Brazilian adult population. More studies involving these professionals need to be carried out in other Brazilian states in order to determine whether the results can be understood as widespread throughout the country.

Soft drink consumption and periodontal status in pregnant women.

BACKGROUND: Periodontal disease is associated with metabolic syndrome, and during pregnancy, it is linked to preeclampsia and preterm birth. We hypothesized that soft drink consumption, which has also been associated with metabolic disorders, may also be linked to periodontal disease. The purpose of this study was to evaluate the association between soft drink consumption and periodontal status in pregnancy. METHODS: This was a cross-sectional study nested in BRISA (Brazilian Ribeirão Preto and São Luís Birth Cohort Studies). Pregnant women (n = 1,185) completed a questionnaire and underwent periodontal examination from the 22nd to 25th week of pregnancy. The explanatory variable was the frequency of soft drink consumption (times per week). The outcome was periodontal status measured as the number of teeth with probing depth ≥4 mm with bleeding on probing (PD/BOP) or with clinical attachment level ≥4 mm (CAL). Means ratio (MR) was estimated using zero-inflated Poisson, adjusted for maternal age and income. RESULTS: The higher tertile of consumption of soft drinks during pregnancy was associated with PD/BOP (MR = 1.34; 95% confidence interval (CI): 1.03 to 1.75); while the highest tertile of diastolic blood pressure was also associated to CAL (MR = 1.21; 95% CI 1:07 to 1.35). CONCLUSION: High soft drink consumption was associated with the number of teeth with PD/BOP in pregnant women, suggesting that beverage consumption is a factor that contributes to the systemic inflammatory burden, which is common to periodontal disease, metabolic syndrome, and adverse pregnancy outcomes.

Impact of percentage and particle size of sugarcane biochar on the sorption behavior of clomazone in Red Latosol.

Biochar is a carbonaceous material that has excellent potential as a fertilizer and soil conditioner. However, there is a lack of information concerning the effects of the amount and particle size of this pyrogenic material on the soil sorption capacity. In this work, evaluation was made of changes in clomazone (CMZ) sorption in a Red Latosol following soil conditioning using different percentages (0.25, 0.5, and 1% w/w) of sugarcane biochar in three particle sizes (<106, 106-508, and 508-610 µm). The conditioned soils presented apparent sorption coefficients (Kd) up to 1300 times higher than that of pure soil, besides changes in the behavior of CMZ sorption. The biochar particle size and percentage influenced sorption of the herbicide as well as its retention in the amended soil during desorption processes. Both sorption and desorption Freundlich constants were linearly correlated with the external surface area of the biochar present in the soil.

Effects of glyphosate on the non-target leaf beetle Cerotoma arcuata (Coleoptera: Chrysomelidae) in field and laboratory conditions.

This study aimed to assess the glyphosate application effects on the Cerotoma arcuata Oliver (Coleoptera: Chrysomelidae) population in glyphosate-resistant soybean crops. Field studies were conducted with glyphosate and the insecticide endosulfan to observe the effects of these pesticides on C. arcuata, on its damages in the crop and on the populations of natural enemies in glyphosate-resistant soybean crops. Moreover, the lethal and behavioral sublethal response of C. arcuata to glyphosate and endosulfan was conducted in the laboratory. The results of the field and laboratory experiments showed that glyphosate caused moderate toxicity and high irritability in C. arcuata and that endosulfan caused high toxicity and irritability. Therefore, the direct effect of glyphosate on C. arcuata was negative and does not explain the population increases of this pest in glyphosate-resistant soybean. However, the glyphosate also decreased the density of predators. Thus, the negative effect of glyphosate on the predators may be related to population increases of C. arcuata in glyphosate-resistant soybean crops, however, more studies are needed to better evidence this relationship. This study suggests that glyphosate can impact other non-target organisms, such as herbivorous insects and natural enemies and that the use of this herbicide will need to be carefully stewarded to prevent potential disturbances in beneficial insect communities in agricultural systems.

Prevalence and Risk Factors for Microcephaly at Birth in Brazil in 2010.

OBJECTIVES: To estimate the baseline prevalence and risk factors for microcephaly at birth before the Zika virus epidemic in 2 Brazilian cities. METHODS: We used population-based data from the Brazilian Ribeirão Preto (RP) and São Luís (SL) birth cohort studies of 2010 that included hospital deliveries by resident mothers. The final sample was 7376 live births in RP and 4220 in SL. Gestational age was based on the date of the mother's last normal menstrual period or obstetric ultrasonography, if available. Microcephaly at birth was classified according to the criteria of the International Fetal and Newborn Growth Consortium for the 21st Century and the Brazilian Ministry of Health. Risk factors for microcephaly, proportionate and disproportionate microcephaly, and severe microcephaly were estimated in a hierarchized logistic regression model. RESULTS: According to the International Fetal and Newborn Growth Consortium for the 21st Century definition, the prevalence of microcephaly (>2 SDs below the mean for gestational age and sex) was higher in SL (3.5%) than in RP (2.5%). The prevalence of severe microcephaly (>3 SDs below the mean) was higher in SL (0.7%) than in RP (0.5%). Low maternal schooling, living in consensual union or without a companion, maternal smoking during pregnancy, primiparity, vaginal delivery, and intrauterine growth restriction were consistently associated with microcephaly. The number of cases of microcephaly is grossly underestimated, with an underreporting rate of ∼90%. CONCLUSIONS: The prevalence of severe microcephaly was much higher than expected in both cities. Our findings suggest that microcephaly was endemic in both municipalities before the circulation of the Zika virus.

Nutrient intake variability and the number of days needed to estimate usual intake in children aged 13-32 months.

The number of days of data required to accurately estimate usual nutrient intake of children is not well established. This study aims to calculate the variability and the number of days required to estimate usual nutrient intake in children aged 13-32 months. This cross-sectional study, which is part of the BRISA Project in São Luís, Maranhão, Brazil, involved 231 children from April 2011 to January 2013. Socio-economic and demographic data were collected using a questionnaire, and 3 non-consecutive days of food consumption were collected using a 24-h dietary recall (24HDR) survey. Intrapersonal and interpersonal variability and variance ratio (VR) were obtained for each nutrient using the Multiple Source Method® program (version 1.0.1). The number of days (d) needed was calculated using the formula proposed by Black et al. for different correlation coefficients (r) (i.e. 0·7, 0·8 or 0·9). For the vast majority of nutrients, intrapersonal and interpersonal variability values of <1 were observed, with even smaller intrapersonal variabilities, resulting in low VR (<1). More days were needed to estimate intakes of soluble fibre (12), insoluble fibre (11), total fibre (10), vitamin C (9) and PUFA (7), while fewer days were needed for energy, carbohydrate, SFA, Ca, Fe, P and Zn (all had 2 d for r 0·9). However, most nutrients required one, two or three 24HDR for r 0·7, 0·8 or 0·9.

Sulfentrazone dechlorination by iron-nickel bimetallic nanoparticles.

The sulfentrazone dechlorination using bimetallic nanoparticles of Fe/Ni was studied. Different variables that could influence the sulfentrazone conversion were investigated, such as nitrogen atmosphere, pH and dosage of the nanoparticles and initial concentration of sulfentrazone. The best results were obtained using controlled pH (pH 4.0) and 1.0 g L(-1) of nanomaterials, resulting in 100 % conversion in only 30 min. Kinetic studies were also conducted, evaluating the influence of different nanoparticle dosages (1.0 to 4.0 g L(-1)), system temperatures (20 to 35 °C) and nickel levels in the composition of the nanomaterials (0.025 to 0.10 gNi/gFe). The mechanism of sulfentrazone conversion has changed due a direct reduction on the catalytic activity sites and indirect reduction by atomic hydrogen. Both mechanisms have followed pseudo-first order models. The conversion rate improved when the dosage of the nanomaterials, system temperature and nickel content in the composition of the nanocomposites were increased. Finally, the conversion products were elucidated by mass spectrometry and toxicity assays were performed using Daphnia Similis. The results showed that the dechlorination product is less toxic than sulfentrazone.