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In recent years, compounds with a cryolite structure have become excellent hosts for luminescent materials. In this paper, Tb 3+ doped and Tb 3+ /Eu 3+ co-doped K 3 LuF 6 phosphors were prepared via a high temperature solid phase sintering method. The XRD, SEM, as well as photoluminescence excitation (PLE) and emission (PL) spectra were measured to investigate the structure and luminescence properties of the as-prepared samples. In the Tb 3+ /Eu 3+ co-doped K 3 LuF 6 samples, both characteristic emission spectra of Tb 3+ and Eu 3+ could be observed and the emission color of the K 3 LuF 6 :0.12Tb 3+ , x Eu 3+ phosphors could be adjusted from green to yellowish pink and the corresponding CIE values could be regulated from (0.2781, 0.5407) in the green area to (0.4331, 0.3556) in the yellowish pink area by controlling the concentration ratio of Eu 3+ /Tb 3+ . In addition, the energy transfer mechanism in Tb 3+ /Eu 3+ co-doped K 3 LuF 6 was calculated to be a quadrupole-quadrupole interaction from Tb 3+ to Eu 3+ based on the Dexter's equation., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

A novel, contactless optical sensor of pressure based on the luminescence red-shift and bandwidth (full width at half-maximum, fwhm) of the Ce 3+ -doped fluorapatite-Y 6 Ba 4 (SiO 4 ) 6 F 2 powder has been successfully synthesized via a facile solid-state method. The obtained material exhibits a bright blue emission under UV light excitation. It was characterized using powder X-ray diffraction, scanning electron microscopy and luminescence spectroscopy, including high-pressure measurements of excitation and emission spectra, up to above ∼30 GPa. Compression of the material resulted in a significant red-shift of the allowed 4f → 5d and 5d → 4f transitions of Ce 3+ in the excitation and emission spectra, respectively. The pressure-induced monotonic shift of the emission band, as well as changes in the excitation/emission band widths, have been correlated with pressure for sensing purposes. The material exhibits a high pressure sensitivity (dλ/d P ≈ 0.63 nm/GPa) and outstanding signal intensity at high-pressure conditions (∼90% of the initial intensity at around 20 GPa) with minimal pressure-induced quenching of luminescence.

In this study, we investigated the structure, luminescence properties and morphology of La 6 Ba 4 (SiO 4 ) 6 F 2 :Dy 3+ in detail using X-ray diffraction (XRD), photoluminescence spectroscopy, scanning electron microscopy (SEM) and decay kinetics measurements. The results indicate that La 6 Ba 4 (SiO 4 ) 6 F 2 :Dy 3+ was well crystallized, and its structure is of apatite-type and belongs to the hexagonal system. The prepared samples exhibit two intense characteristic bands in the blue (484 nm) and yellow (579 nm) spectral ranges corresponding to the Dy 3+ transitions 4 F 9/2 → 6 H 15/2 and 4 F 9/2 → 6 H 13/2 , respectively. These dominant photoluminescence bands are accompanied by a weak red band (670 nm) due to the 4 F 9/2 → 6 H 11/2 transition. The emission color of La 6 Ba 4 (SiO 4 ) 6 F 2 :Dy 3+ phosphors are found to fall in the white light region. The Dy 3+ optimal dopant concentration in the La 6 Ba 4 (SiO 4 ) 6 F 2 host was found to be 0.12 (mol). In addition, the phosphors have high thermal stability. Hence, La 6 Ba 4 (SiO 4 ) 6 F 2 :Dy 3+ may have an application in white light-emitting diodes., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The Ba 2 La 2.85- x Tb 0.15 Eu x (SiO 4 ) 3 F (BLSOF:0.15Tb 3+ , x Eu 3+ ) multicolor phosphors with apatite structure were synthesized via the solid-state pathway. The crystal structure and luminescence properties of the phosphors were investigated by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), Rietveld refinement, photoluminescence excitation (PLE) and photoluminescence (PL). The luminescence performance of the phosphor was optimum when the concentration of Tb 3+ was set to be 0.15 mol and the concentration of Eu 3+ was set to be 0.22 mol. Under the accurate excitation of 373 nm near ultraviolet (n-UV) light, the emitting color of the phosphors can be tuned from green to red with increasing Eu 3+ /Tb 3+ ratio. It was further proved that the quadrupole-quadrupole (q-q) interaction is responsible for the energy transfer (ET) in the BLSOF:0.15Tb 3+ , 0.22Eu 3+ phosphor. Owing to the excellent thermal quenching luminescence property, the BLSOF:0.15Tb 3+ , x Eu 3+ phosphor can be applied in n-UV white light emitting diodes (w-LEDs) and serve as the warm part of warm white light., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Objective: The purpose of this study was to investigate the relationship between urinary nickel and methylation of p15, p16 in workers exposed to nickel., Methods: In this study, 165 nickel-exposed workers and 67 workers without exposure were recruited. The levels of urinary nickel were analyzed using dimethylglyoxime spectrophotometric method. Methylation-specific polymerase chain reaction was used to detect the methylation of p15 and p16., Results: The median concentration of urinary nickel in the exposed group (4.58 μg/L) was significantly higher than that in the control group (1.78 μg/L; P < 0.01). The rate of methylation of p15 in the exposed group was significantly higher than that in the control group (P = 0.023). The multiple logistic analysis showed that workers having higher urinary nickel were at the higher risk of methylation of p15 (P = 0.024)., Conclusions: The levels of urinary nickel were significantly associated with the methylation of p15.