Representative levels of blood lead, mercury, and urinary cadmium in youth: Korean Environmental Health Survey in Children and Adolescents (KorEHS-C), 2012–2014

AbstractBackgroundThis study examined levels of blood lead and mercury, and urinary cadmium, and associated sociodemographic factors in 3–18 year-old Korean children and adolescents.Materials and methodsWe used the nationally representative Korean Environmental Health Survey in Children and Adolescents data for 2012–2014 and identified 2388 children and adolescents aged 3–18 years. The median and 95th percentile exposure biomarker levels with 95% confidence intervals (CIs) were calculated. Multivariate regression analyses were performed on log transformed exposure biomarker levels adjusted for age, sex, area, household income, and father’s education level. The median exposure biomarker levels were compared with data from Germany, the US, and Canada, as well as the levels of Korean children measured at different times.ResultsThe median levels of blood lead and mercury, as well as urinary cadmium were 1.23μg/dL, 1.80μg/L, and 0.40μg/L (95% CIs, 1.21–1.25, 1.77–1.83, and 0.39–0.41, respectively). The blood lead levels were significantly higher in boys and younger children (p<0.0001) and children with less educated fathers (p=0.004) after adjusting for covariates. Urinary cadmium level increased with age (p<0.0001). The median levels of blood mercury and urinary cadmium were much higher in Korean children and adolescents than those in their peers in Germany, the US, and Canada. Blood lead levels tended to decrease with increasing age and divergence between the sexes, particularly in the early teen years. Median levels of blood lead and urinary cadmium decreased since 2010.ConclusionSociodemographic factors, including age, sex, and father’s education level were associated with environmental exposure to heavy metals in Korean children and adolescents. These biomonitoring data are valuable for ongoing surveillance of environmental exposure in this vulnerable population

Ordered mesoporous WO3-x Possessing electronically conductive framework comparable to carbon framework toward long-term stable cathode supports for fuel cells

We report on the successful synthesis of ordered mesoporous WO3-X with a high conductivity comparable to a mesoporous carbon framework. Ordered mesoporous WO3-X was prepared using KIT-6 as a hard template. Some WO3-X particles have negative replica structures of KIT-6 template and the other particles are generated by asymmetric incorporation of phosphotungstic acid inside channels of KIT-6 template. The wall of this mesostructured WO3-X has a single crystalline structure, which might be responsible for its high conductivity (1.76 S cm(-1)) comparable to ordered mesoporous carbons (3.0 S cm(-1)). Pt/mesoporous WO3-X exhibits a significant tolerance to cycling between 0.6 and 1.3 V-NHE in 0.5 M H2SO4 solution, preserving 87% of its initial electrochemical surface area (ECSA) after 1000 cycles. On the contrary, the ECSA of the Pt/C decreased significantly with the number of cycles, resulting in loss of 74% of its initial ECSA.X1155sciescopu

Facile synthesis of various phosphine-stabilized monodisperse palladium nanoparticles through the understanding of coordination chemistry of the nanoparticles

We developed facile synthetic procedures to produce monodisperse palladium nanoparticles stabilized with various phosphine ligands by a better understanding of their coordination chemistry. Compared to small sized phosphines such as triphenylphosphine (TPP), trioctylphosphine (TOP) showed weaker coordination ability to palladium nanoparticles. This result was ascertained based on the P-31 NMR spectroscopic results of in situ generated molecular palladium complexes. Since TOP acts as a more efficient surfactant in the preparation of high quality monodisperse palladium nanoparticles than smaller sized phosphines, we conducted surfactant exchange reactions of TOP-stabilized palladium nanoparticles in order to produce monodisperse palladium nanoparticles stabilized with various other phosphines. These monodisperse nanoparticles include monodisperse Pd nanoparticles stabilized with chiral ligands and water-dispersable Pd nanoparticles.

PIL5, a Phytochrome-Interacting Basic Helix-Loop-Helix Protein, Is a Key Negative Regulator of Seed Germination in Arabidopsis thaliana

The first decision made by an angiosperm seed, whether to germinate or not, is based on integration of various environmental signals such as water and light. The phytochromes (Phys) act as red and far-red light (Pfr) photoreceptors to mediate light signaling through yet uncharacterized pathways. We report here that the PIF3-like 5 (PIL5) protein, a basic helix-loop-helix transcription factor, is a key negative regulator of phytochrome-mediated seed germination. PIL5 preferentially interacts with the Pfr forms of Phytochrome A (PhyA) and Phytochrome B (PhyB). Analyses of a pil5 mutant in conjunction with phyA and phyB mutants, a pif3 pil5 double mutant, and PIL5 overexpression lines indicate that PIL5 is a negative factor in Phy-mediated promotion of seed germination, inhibition of hypocotyl negative gravitropism, and inhibition of hypocotyl elongation. Our data identify PIL5 as the first Phy-interacting protein that regulates seed germination

Shape-Encoded Chitosan–Polyacrylamide Hybrid Hydrogel Microparticles with Controlled Macroporous Structures via Replica Molding for Programmable Biomacromolecular Conjugation

Polymeric hydrogel microparticle-based suspension arrays with shape-based encoding offer powerful alternatives to planar and bead-based arrays toward high throughput biosensing and medical diagnostics. We report a simple and robust micromolding technique for polyacrylamide- (PAAm-) based biopolymeric–synthetic hybrid microparticles with controlled 2D shapes containing a potent aminopolysaccharide chitosan as an efficient conjugation handle uniformly incorporated in PAAm matrix. A postfabrication conjugation approach utilizing amine-reactive chemistries on the chitosan shows stable incorporation and retained chemical reactivity of chitosan, readily tunable macroporous structures via simple addition of low content long-chain PEG porogens for improved conjugation capacity and kinetics, and one-pot biomacromolecular assembly via bioorthogonal click reactions with minimal nonspecific binding. We believe that the integrated fabrication-conjugation approach reported here could offer promising routes to programmable manufacture of hydrogel microparticle-based biomacromolecular conjugation and biofunctionalization platforms for a large range of applications