'Getting control of Corona takes many angles': COVID-19 vaccine knowledge, attitudes and beliefs among refugee/immigrant/migrant communities in four US cities.

The objectives of the study were to (i) document refugee, immigrant and migrant (RIM) communities' knowledge, attitudes and beliefs (KABs) related to the Coronavirus disease (COVID-19) vaccine and (ii) identify best practices for developing and disseminating culturally and linguistically responsive health messaging addressing those KABs. Thirteen online focus groups (OFGs) in 10 languages were conducted. Each OFG was conducted in the participants' native language. OFGs were recorded, transcribed, translated and uploaded to qualitative software for coding. A thematic analysis was conducted. Results suggest that while there was some variation between different language groups (e.g. whether religious leaders were seen as trusted sources of information about COVID), there were also important commonalities. Most language groups (i) alluded to hearing about or having gaps in knowledge about COVID-19/the COVID-19 vaccine, (ii) reported hearing negative or conflicting stories about the vaccine and (iii) shared concerns about the negative side effects of the vaccine. There continues to be a need for health messaging in RIM communities that is culturally and linguistically concordant and follows health literacy guidelines. Message content about the COVID-19 vaccine should focus on vaccine importance, effectiveness and safety, should be multimodal and should be primarily delivered by healthcare professionals and community members who have already been vaccinated.

Trivalent rare-earth-codoped silicate phosphor materials (Ba1.3Ca0.7-x-ySiO4:xDy3+/yEu3+) for solid-state lighting.

Trivalent dysprosium/europium-codoped silicate phosphors (Ba1.3Ca0.7x-ySiO4:xDy3+/yEu3+) were prepared as a function of Eu3+concentration (x= 0.03 andy= 0.01-0.05). The phosphors showed the averaged crystallite size of ∼37.2 ± 1.3 nm and displayed nano-/micro-scale grains with some void defects. The energy bandgap is about 4.3 eV for co-doped samples and 3.2 eV for the silicate host. The photoluminescence spectra indicated that the presence of Eu3+ions enhanced the red light emission, and the emission peaks located at the versatile wavelengths of 482, 577, 592, 614, 652, and 703 nm. Then, the internal quantum efficiencies were estimated by using the Judd-Ofelt model. Resultantly, the best quantum efficiency was ∼74% when the doping concentrations were 3 mol% Dy3+and 4 mol% Eu3+ions. Finally, the CIE coordinate data exhibited that the emission color could be tuned from white to reddish-orange by changing the Eu3+contents, proposing the applicability of Ba1.3Ca0.7-x-ySiO4:xDy3+/yEu3+phosphors to the solid-state lighting.

Photoluminescence processes in τ-phase Ba1.3Ca0.7-x-y SiO4:xDy 3+/yTb3+ phosphors for solid-state lighting.

The τ-phase Ba1.3Ca0.7-x-y SiO4:xDy 3+/yTb3+ phosphors co-doped with Dy 3+ (x = 0.03) and Tb3+ (y = 0.01-0.05) trivalent rare-earth ions were prepared by the gel-combustion method. The structure-property relation of the samples was examined by X-ray diffraction, scanning electron microscopy and spectrophotometer. Here, the effect of Tb3+'s concentration on the spectroscopic properties of Ba1.3Ca0.7-x-y SiO4:xDy 3+/yTb3+ phosphors was explored by using the photoluminescence excitation, emission and decay curves. Importantly, the photonic energy transfer from (Dy 3+:4F9/2 + Tb3+:7F6) to (Dy 3+:6H15/2 + Tb3+:5D4) was observed, in which the Dy 3+ ions act as a light-emitting donor whereas the Tb3+ ions as a light-absorbing acceptor, resulting in an enhanced emission from the co-doped Ba1.3Ca0.7-x-y SiO4:xDy 3+/yTb3+ (x = 0.03 and y = 0.01-0.05) phosphors. Finally, the chromaticity coordinates were determined from the measured emission spectra, locating at the green and white light regions. This observation indicates that the characteristic emission colour could be tuned from white to green by varying Tb3+ concentrations under ultraviolet light.