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Low- and medium-C steel powders were additively deposited on gray cast iron using a directed energy deposition (DED) process to identify the effect of the carbon content in the steel powder on the soundness of DED-processed cast iron in terms of the mechanical and microstructural properties. As a representative mechanical property, impact toughness tests of DED-processed cast iron specimens were performed, and then fractography was employed to understand the microstructure-dependent crack propagation resistance. Microstructural changes and chemical variations were investigated using multi-scale microstructure characterization as the layer-dependent properties. In particular, the microstructural characteristics across the interface were intensively analyzed to understand the effect of laser-heated low- and medium-C steel powders on a (high C) cast iron substrate. Elucidating the microstructural changes and the resulting mechanical properties of the deposits necessitated understanding the variations caused by the chemistry of the deposited powder and the effect of dilution with the substrate material. These layer-dependent properties and the resultant compatibility at the interface should be considered when selecting the feedstock material and designing the DED repair process.

Appropriate adjustment of various microclimatic and nutrient conditions can improve crop productivity under greenhouse cultivation. Here, we performed non-targeted profiling to investigate metabolite variation in tomato fruits following different supplementary LED lighting (SL) (red: R; blue: B; and a combination of red and blue light: RB, for 1 h/day and 6 h/day per condition) and mineral nutrient supply (N, K, Mg). The different SL treatments affected metabolite variation in tomato fruits more significantly than mineral nutrients. Importantly, regulating the SL period induced a more distinct metabolite composition in tomato fruits than that induced by varying the SL sources. Tomato fruits cultivated under RB for 6 h/day had a relatively higher content of sugar derivatives, especially sucrose, thus influencing the gustatory characteristics of the fruit. In contrast, fruit from tomatoes cultivated under RB for 1 h/day showed a distinctive increase in the abundance of amino acids, organic acids, and several secondary metabolites, adding to its nutritional quality. Intriguingly, the different mineral supplements elicited discriminant metabolic variation in tomato fruits cultivated under reduced levels of mineral supply; however, the effects were insignificant under enhanced levels of mineral supply. Specifically, reduced level in nitrogen supply resulted in a lower abundance of amino acids, whereas reduced level in potassium supply increased metabolite levels including amino acids, sugars, and fatty acids in tomato fruits. In the present study, we employed a non-targeted metabolomics approach to unravel the effects of microclimatic parameters and mineral nutrients on fruit quality parameters of tomato plants, by which regulating the period of SL and reducing the potassium concentration were suggested to improve different nutritional qualities.

The COVID-19 pandemic substantially disrupted healthcare utilization patterns, globally. South Korea had been praised widely in its efforts to contain the spread of the pandemic, which may have contributed to a significantly smaller reduction in healthcare utilization compared to neighboring countries. However, it remains unknown how the COVID-19 pandemic impacted utilization patterns across population sub-groups, particularly vulnerable patient groups in South Korea. This paper quantifies the changes in healthcare utilization attributable to COVID-19 and the COVID-19 vaccination by sub-groups.

We analyzed the contents of 38 primary metabolites and 9 minerals in the leaves and roots of bell pepper (Capsicum annuumL. var. angulosum) to study metabolic responses to deficiency in nitrogen, phosphorus, potassium, calcium, or magnesium. Induced deficiencies of individual cations reduced the abundance of the other cations in both leaves and roots. Each nutrient-deficient condition was clearly grouped by principal component analysis, which also showed that leaves under cation-deficiency treatments were separated from those under non-cation-deficiency treatments. This was consistent with that a single cation deficiency decreased the levels of the other cations in leaves. Specifically, N deficiency reduced amino acids and organic acids in both tissues. The common response to P-, K-, Ca- or Mg-deficient conditions showed significant increases in the levels of amino acids in both tissues and organic acids in the roots. In the leaves, P- or Mg-deficient conditions reduced organic acids. Soluble carbohydrates were significantly increased under N-, K-, Ca- or Mg-deficient conditions in the leaves, whereas in roots under K deficiency. Notably, the level of γ-aminobutyric acid, an amino acid that helps protect against biotic and abiotic stresses, was increased threefold in leaves under K-deficient conditions and sixfold in roots under P-, K-, Ca-, or Mg-deficient conditions. These findings provide additional information about variations in metabolite and mineral abundance in bell pepper leaves and roots in response to mineral shortage.

Although conventional topical approaches for treating psoriasis have been offered as an alternative, there are still unmet medical needs such as low skin-penetrating efficacy and off-target adverse effects. A hyaluronic acid nanoparticle (HA-NP) formed by self-assembly of HA-hydrophobic moiety conjugates has been broadly studied as a nanocarrier for long-term and target-specific delivery of drugs, owing to their excellent physicochemical and biological characteristics. Here, we identify HA-NPs as topical therapeutics for treating psoriasis using in vivoskin penetration studies and psoriasis animal models. Transcutaneously administered HA-NPs were found to be accumulated and associated with pro-inflammatory macrophages in the inflamed dermis of a psoriasis mouse model. Importantly, HA-NP exerted potent therapeutic efficacy against psoriasis-like skin dermatitis in a size-dependent manner by suppressing innate immune responses and restoring skin barrier function without overt toxicity signs. The therapeutic efficacy of HA-NPs on psoriasis-like skin dermatitis was due to the outermost hydrophilic HA shell layer of HA-NPs, independent of the molecular weight of HA and hydrophobic moiety, and comparable with that of other conventional psoriasis therapeutics widely used in the clinical settings. Overall, HA-NPs have the potential as a topical nanomedicine for treating psoriasis effectively and safely.