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Background: Obesity and diabetes are known risk factors for severe dengue. Therefore, we sought to investigate the association of obesity with increased risk of hospitalization, as there is limited information., Methods and Findings: Children aged 10 to 18 years (n = 4782), were recruited from 9 districts in Sri Lanka using a stratified multi-stage cluster sampling method. Details of previous admissions to hospital due to dengue and anthropometric measurements were recorded and seropositivity rates for dengue were assessed. The body mass index (BMI) centile in children aged 10 to 18, was derived by plotting the values on the WHO BMI-for-age growth charts, to acquire the percentile ranking., Results: Although the dengue seropositivity rates were similar in children of the different BMI centiles, 12/66 (18.2%) seropositive children with a BMI centile >97th, had been hospitalized for dengue, compared to 103/1086 (9.48%) of children with a BMI centile of <97th. The logistic regression model suggested that BMI centiles 50th to 85th (OR = 1.06, 95% CI, 1.00 to 1.11, p = 0.048) and BMI centile of >97th (OR 2.33, 95% CI, 1.47 to 3.67, p = 0.0003) was significantly associated with hospitalization when compared to children in other BMI categories., Conclusions: Obesity appears to be associated with an increased risk of hospitalization in dengue, which should be further investigated in longitudinal prospective studies. With the increase in obesity in many countries, it would be important to create awareness regarding obesity and risk of severe disease and hospitalization in dengue., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Jeewandara et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Photocatalytic nanofibers of TiO 2 decorated with 2% metal (Pt, Pd, and Cu) and metal alloys (Pt 2 Pd and PtCu) were synthesized by the polymer-assisted electrospinning method, followed by microwave-assisted ethylene glycol reduction. Structurally, nanofibers calcined at 500 °C adopted an anatase phase along with a remnant rutile phase. Morphological, structural, and photocatalytic studies were carried out using scanning and transmission electron microscopy equipped with an energy dispersive spectroscopy attachment, X-ray powder diffraction, X-ray photoelectron spectroscopy, and photocatalytic hydrogen generation under UV-Vis irradiation. The calcined nanofibers were found to have a diameter of 60.0 ± 5.0 nm and length of up to several microns. High resolution TEM imaging suggests that the nanofibers are composed of agglomerated individual TiO 2 nanoparticles, which are tightly packed and stacked along the axial direction of the nanofibers. PXRD studies suggest alloy formation, as evident from peak shifting towards higher two-theta values. Surface modification with co-catalysts is shown to contribute considerably to the rate of photocatalytic H 2 generation. The amount of H 2 generated gradually increases as a function of time. The 2%Pt 2 Pd/TiO 2 catalyst shows the highest rate of H 2 generation (4 mmol h -1 gram catalyst ), even higher than that of 2%Pt/TiO 2 nanofiber photocatalyst (2.3 mmol h -1 gram catalyst ), while 2%Cu/TiO 2 nanofiber photocatalyst shows the least activity among the decorated catalysts (0.04 mmol h -1 gram catalyst )., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Due to their unique catalytic, electronic, and redox processes, Ni5P4 and NiP2 nanoparticles are of interest for a wide-range of applications from the hydrogen evolution reaction to energy storage (batteries); yet synthetic approaches to these materials are limited. In the present work, a phase-control strategy enabling the arrested-precipitation synthesis of nanoparticles of Ni5P4 and NiP2 as phase-pure samples using different Ni organometallic precursors and trioctylphosphine (TOP) is described. The composition and purity of the product can be tuned by changing key synthetic levers, including the Ni precursor, the oleylamine (OAm) coordinating solvent and TOP concentrations, temperature, time, and the presence or absence of a moderate temperature soak step to facilitate formation of Ni and/or Ni-P amorphous nanoparticle intermediates. Notably, the 230 °C intermediate step favors the ultimate formation of Ni2P and hinders further phosphidation to form Ni5P4 or NiP2 as phase-pure products. In the absence of this step, increasing the P/Ni ratio (13-20), reaction temperature (350-385 °C), and time (10-48 h) favors more P-rich phases, and these parameters can be adjusted to generate either Ni5P4 or NiP2. The phase of the obtained particles can also be tuned between pure Ni2P to Ni5P4 and NiP2 by simply decreasing the OAm/TOP ratio and/or changing the nickel precursor (nickel(II)acetylacetonate, nickel(II)acetate tetrahydrate, or bis(cyclooctadiene)nickel(0)). However, at high concentrations of OAm, the product formed is the same regardless of Ni precursor, suggesting the formation of a uniform Ni intermediate (an Ni-oleylamine complex) under these conditions that is responsible for product distribution. Intriguingly, under the extreme phosphidation conditions required to favor Ni5P4 and NiP2 over Ni2P (large excess of TOP), the 20-30 nm crystallites assemble into supraparticles with diameters of 100-500 nm. These factors are discussed in light of a comprehensive synthetic scheme utilized to control P incorporation in nickel phosphides.

The applicability of sol-gel nanoparticle assembly routes, previously employed for metal chalcogenides, to phosphides is reported for the case of InP. Two different sizes (3.5 and 6.0 nm) of InP nanoparticles were synthesized by solution-phase arrested precipitation, capped with thiolate ligands, and oxidized with H₂O₂ or O₂/light to induce gel formation. The gels were aged, solvent-exchanged, and then supercritically dried to obtain aerogels with both meso- (2-50 nm) and macropores (>50 nm) and accessible surface areas of ∼200 m²/g. Aerogels showed higher band gap values relative to precursor nanoparticles, suggesting that during the process of assembling nanoparticles into 3D architectures, particle size reduction may have taken place. In contrast to metal chalcogenide gelation, InP gels did not form using tetranitromethane, a non-oxygen-transferring oxidant. The requirement of an oxygen-transferring oxidant, combined with X-ray photoelectron spectroscopy data showing oxidized phosphorus, suggests gelation is occurring due to condensation of phosphorus oxoanionic moieties generated at the interfaces. The ability to link discrete InP nanoparticles into a 3D porous network while maintaining quantum confinement is expected to facilitate exploitation of nanostructured InP in solid-state devices.

Discrete nanoparticles of MnAs with distinct magnetostructural properties have been prepared by small modifications of solution-phase arrested precipitation reactions. Rietveld and X-ray atomic pair distribution function based approaches were used to explore the evolution of the structure of the samples with temperature, and these data were compared to the magnetic response measured with ac susceptibility. Relative to a bulk standard, one type of MnAs nanoparticles was found to demonstrate similar but smaller structural transitions and corresponding magnetic changes. However, both magnetic and structural transitions in the second type of nanoparticles are strongly suppressed.

Nanocrystals of thermodynamically stable alpha-MnAs (hexagonal NiAs-type) and metastable beta-MnAs (orthorhombic MnP-type) have been synthesized by the reaction of triphenylarsine oxide (Ph(3)AsO) and dimanganesedecacarbonyl (Mn(2)CO(10)) at temperatures ranging from 250 to 330 degrees C in the presence of the coordinating solvent trioctylphosphine oxide (TOPO). Morphologically, both alpha- and beta-MnAs nanoparticles adopt a core-shell type structure with a crystalline core and low-contrast noncrystalline shell. In contrast to prior studies on MnAs particles, disks, and films, the present bottom-up synthesis yields discrete, dispersible MnAs nanoparticles without a structural support. Even in the absence of epitaxial strain, the lattice parameters of the nanocrystals are decreased relative to bulk MnAs, resulting in a volume decrease of 0.35% in alpha-MnAs and 0.38% in beta-MnAs nanoparticles. In contrast to bulk MnAs, where the ferromagnetic phase transition upon warming through 313-317 K is concomitant with a structure change from ferromagnetic alpha- to paramagnetic beta-MnAs, powder X-ray diffraction studies suggest there is no conversion of alpha-MnAs to beta over the temperature range 298-343 K. Moreover, magnetic measurements suggest that both alpha- and beta-MnAs are ferromagnetic with T(C) approximately 315 K. Partial phase transformation of beta-MnAs nanoparticles into thermodynamically stable alpha-MnAs occurs slowly over time (i.e., months) at room temperature. However, there is no associated change in magnetization, suggesting the ferromagnetism observed in beta-MnAs is intrinsic and cannot be attributed to alpha-MnAs impurities.