RESUMO
Young children in resource-constrained settings are susceptible to zinc deficiency and its deleterious health effects. The objective of this secondary analysis was to evaluate the effects of the following six interventions on biomarkers of iron and zinc status among a subgroup of young children in Dhaka, Bangladesh, who participated in the Zinc in Powders Trial (ZiPT): (1) standard micronutrient powders (MNPs) containing 4.1 mg zinc and 10 mg iron, daily; (2) high-zinc (10 mg) and low-iron (6 mg) (HiZn LoFe) MNP, daily; (3) HiZn (10 mg) and LoFe (6 mg)/HiZn (10 mg) and no-iron MNPs on alternating days; (4) dispersible zinc tablet (10 mg), daily; (5) dispersible zinc tablet (10 mg), daily for 2 weeks at enrollment and at 12 weeks; (6) placebo powder, daily. At the end of the 24 week intervention period, children in the daily dispersible zinc tablet group exhibited a mean serum zinc concentration (SZC) of 92.5 µg/dL, which was significantly higher than all other groups except the HiZn LoFe MNP alternating group (81.3 µg/dL). MNPs containing 10 mg and 6 mg of iron had a similar impact on biomarkers of iron status, with no evidence of an adverse interaction with zinc.
Assuntos
Anemia Ferropriva , Oligoelementos , Humanos , Criança , Lactente , Pré-Escolar , Zinco , Suplementos Nutricionais , Bangladesh , Micronutrientes , Biomarcadores , Pós , ComprimidosRESUMO
The deployment of two-dimensional (2D) materials for solar energy conversion requires scalable large-area devices. Here, we present the design, modeling, fabrication, and characterization of monolayer MoS2-based lateral Schottky-junction photovoltaic (PV) devices grown by using chemical vapor deposition (CVD). The device design consists of asymmetric Ti and Pt metal contacts with a work function offset to enable charge separation. These early stage devices show repeatable performance under 1 sun illumination, with VOC of 160 mV, JSC of 0.01 mA/cm2, power conversion efficiency of 0.0005%, and specific power of 1.58 kW/kg. An optoelectronic model for this device is developed and validated with experimental results. This model is used to understand loss mechanisms and project optimized device designs. The model predicts that a 2D PV device with â¼70 kW/kg of specific power can be achieved with minimum optimization to the current devices. By increasing the thickness of the absorber layer, we can achieve even higher performance devices. Finally, a 25 mm2 area solar cell made with a 0.65 nm thick MoS2 monolayer is demonstrated, showing VOC of 210 mV under 1 sun illumination. This is the first demonstration of a large-area PV device made with CVD-grown scalable 2D materials.
RESUMO
A library of 17 novel estrogen analogues 3 and 4 containing different substituents at rings A and D (steroid nomenclature) was prepared in a five- to seven-step synthesis. The key transformation is a Sonogashira-coupling of cyclic vinyl iodides of type 7 or 8 with phenylacetylenes of type 9. Reduction of the keto function in 3 led to the estradiol analogue 5.