RESUMO
This research describes the proportion of children in four low- and middle-income countries with adequate dietary practices at 6, 12, 18 and 24 months of age and how these practices changed over time using the World Health Organisation and UNICEF's infant young child feeding (IYCF) indicators. The associations between the IYCF indicators and anthropometric z-scores from 6 to 24 months, and between the IYCF indicators and the family care indicators (FCIs) at 24 months are described. This was a longitudinal study of offspring from participants in the Women First Preconception Maternal Nutrition Trial conducted in Sud-Ubangi, Democratic Republic of Congo; Chimaltenango, Guatemala; Belagavi, North Karnataka, India; and Thatta, Sindh Province, Pakistan. The frequency of the minimum dietary diversity (MDD), minimum meal frequency (MMF), and minimum adequate diet (MAD) increased between 6 and 24 months, but even at 24 months MAD remained below 50% at all sites. MDD (ß = 0.12; 95% CI = 0.04-0.22) and MMF (ß = 0.10; 95% CI = 0.03-0.17) were positively associated with length-for-age z-score at 24 months. All IYCF indicators were positively associated with mean total FCI score: MDD (proportion ratio [PR] = 1.04; 95% CI = 1.02-1.07), MMF (PR = 1.02; 95% CI = 1.01-1.04), MAD (PR = 1.05; 95% CI = 1.02-1.08). Although there are multiple barriers to young children having an adequate diet, our results support a positive association between familial interactions and improved IYCF feeding practices.
Assuntos
Aleitamento Materno , Fenômenos Fisiológicos da Nutrição do Lactente , Lactente , Criança , Humanos , Feminino , Pré-Escolar , Estudos Longitudinais , Índia , Dieta , Comportamento AlimentarRESUMO
Vanadium-based catalysts have shown activity and selectivity in ring-opening metathesis polymerization of strained cyclic olefins comparable to those of Ru, Mo, and W catalysts. However, the application of V alkylidenes in routine organic synthesis is limited. Here, we present the first example of ring-closing olefin metathesis catalyzed by well-defined V chloride alkylidene phosphine complexes. The developed catalysts exhibit tolerance to various functional groups, such as an ether, an ester, a tertiary amide, a tertiary amine, and a sulfonamide. The size and electron-donating properties of the imido group and the phosphine play a crucial role in the stability of active intermediates. Reactions with ethylene and olefins suggest that both ß-hydride elimination of the metallacyclobutene and bimolecular decomposition are responsible for catalyst degradation.
RESUMO
Catalytic olefin metathesis based on the second- and third-row transition metals has become one of the most powerful transformations in modern organic chemistry. The shift to first-row metals to produce fine and commodity chemicals would be an important achievement to complement existing methods with inexpensive and greener alternatives. In addition, those systems can offer unusual reactivity based on the unique electronic structure of the base metals. In this Minireview, we summarize the progress of the development of alkylidenes and metallacycles of first-row transition metals from scandium to nickel capable of performing cycloaddition and cycloreversion steps, crucial reactions in olefin metathesis. In addition, we will discuss systems capable of performing olefin metathesis; however, the nature of active species is not yet known.
RESUMO
BACKGROUND: Up-to-date dietary data are required to understand the diverse nutritional challenges of pregnant women living in low-middle income countries (LMIC). To that end, dietary data were collected from 1st trimester pregnant women in rural areas of Guatemala, India, Pakistan, and Democratic Republic of the Congo (DRC) participating in a maternal lipid-based nutrient supplement (LNS) Randomized Controlled Trial to examine dietary diversity (DD), usual group energy and nutrient intakes, and prevalence of inadequate dietary intakes. METHODS: Two 24-h dietary recalls were conducted in ~240 pregnant women/site (total n = 966) prior to 12-week gestation. Adequate DD was assessed, i.e., ≥5 major food groups consumed within the past 24 h. Median, Q1, Q3 intakes (without LNS) of energy, macronutrients, 12 micronutrients, and phytate were examined. The "at risk" prevalence of inadequate intakes were based on international guidelines for pregnant women. RESULTS: Dietary patterns varied widely among sites, with adequate DD reported: 20% (Pakistan), 25% (DRC), 50% (Guatemala), and 70% (India). Significantly higher intakes of most key nutrients were observed in participants with adequate DD. More than 80% of women in all sites had inadequate intakes of folate, vitamin B12, and choline, and >80% of women in India and DRC also had inadequate intakes of calcium, thiamine, riboflavin, and vitamin B6. CONCLUSIONS: Our data highlight the likely need for micronutrient supplementation in pregnancy, specifically multi-micronutrient interventions, and support the value of increasing DD as part of sustainable long-term nutrition programs for women of reproductive age in these poor rural settings in LMIC.
Assuntos
Dieta , Desnutrição , Estado Nutricional , Complicações na Gravidez , Adulto , República Democrática do Congo , Países em Desenvolvimento , Dieta/métodos , Dieta/estatística & dados numéricos , Suplementos Nutricionais , Feminino , Guatemala , Humanos , Índia , Desnutrição/dietoterapia , Desnutrição/epidemiologia , Paquistão , Pobreza , Gravidez , Complicações na Gravidez/dietoterapia , Complicações na Gravidez/epidemiologia , Prevalência , Adulto JovemRESUMO
Background: Our aim was to utilize a feasible quantitative methodology to estimate the dietary adequacy of >900 first-trimester pregnant women in poor rural areas of the Democratic Republic of the Congo, Guatemala, India and Pakistan. This paper outlines the dietary methods used. Methods: Local nutritionists were trained at the sites by the lead study nutritionist and received ongoing mentoring throughout the study. Training topics focused on the standardized conduct of repeat multiple-pass 24-hr dietary recalls, including interview techniques, estimation of portion sizes, and construction of a unique site-specific food composition database (FCDB). Each FCDB was based on 13 food groups and included values for moisture, energy, 20 nutrients (i.e. macro- and micronutrients), and phytate (an anti-nutrient). Nutrient values for individual foods or beverages were taken from recently developed FAO-supported regional food composition tables or the USDA national nutrient database. Appropriate adjustments for differences in moisture and application of nutrient retention and yield factors after cooking were applied, as needed. Generic recipes for mixed dishes consumed by the study population were compiled at each site, followed by calculation of a median recipe per 100 g. Each recipe's nutrient values were included in the FCDB. Final site FCDB checks were planned according to FAO/INFOODS guidelines. Discussion: This dietary strategy provides the opportunity to assess estimated mean group usual energy and nutrient intakes and estimated prevalence of the population 'at risk' of inadequate intakes in first-trimester pregnant women living in four low- and middle-income countries. While challenges and limitations exist, this methodology demonstrates the practical application of a quantitative dietary strategy for a large international multi-site nutrition trial, providing within- and between-site comparisons. Moreover, it provides an excellent opportunity for local capacity building and each site FCDB can be easily modified for additional research activities conducted in other populations living in the same area.