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Rare-earth doped oxysulfides have gained considerable attention as a luminescence host material owing to its good chemical stability and high efficiency. In this study, Er3+-sensitized La2O2S nanoparticles are prepared by the high-temperature co-precipitation method. La2O2S:2%Er3+ is selected to construct La2O2S:Er3+@La2O2S core/shell structures through epitaxial growth, and the luminescence properties are studied. The surface defects of La2O2S:Er3+ are repaired by the inert protective shell, and the luminescence intensity of the core/shell nanocrystals is increased by 9.6 times. Finally, MAPbI3 is spin-coated over the La2O2S:Er3+@La2O2S film to construct narrow band near-infrared photodetectors. Under 1550 nm excitation, the response rate is 23 mA W−1, detection rate is 2.57 × 108 Jones, and response time is 220 ms. [ABSTRACT FROM AUTHOR]

Lanthanide ion-doped up-conversion (UC) luminescent materials are highly coveted for their utility in diverse applications such as anti-counterfeiting, fluorescence labeling, and temperature sensing. Here, we attempt to adopt SrY2S4 as a novel host lattice for UC luminescence and high-sensitive optical thermometry under near-infrared irradiation. The results show that the single Er3+-doped SrY2S4 samples present their main emissions in green and red regions under 1550 and 980 nm excitations, which correspond to the H11/2/4S3/2 → 4I15/2 and 4F9/2 → 4I15/2 transitions of Er3+ ions, respectively. The green to red intensity ratio increases with the Er3+ concentration under both 980 and 1550 nm excitations. The mechanisms of UC luminescence and energy transfer are further systematically investigated by UC spectra and fluorescence decay dynamics. Furthermore, the non-contact temperature sensing performance of the SrY2S4:10%Er3+ sample is explored via employing fluorescence intensity ratio (FIR) technology. At an excitation of 980 nm, the maximum absolute sensitivity (SA) reaches 7.5 × 10−3 K−1 at 480 K. By utilizing a much safer excitation laser of 1550 nm, the maximum SA achieves 8.4 × 10−3 K−1 at 450 K, with a high and stable SA of more than 7.9 × 10−3 K−1 over a broad temperature range of 360–570 K. The relative sensitivity is 1.06% and 1.01% K−1 under 980 and 1550 nm excitations, respectively. These results indicate that the ternary sulfide SrY2S4 can be adopted as a novel host to achieve promising UC luminescence and thermal sensing performance. [ABSTRACT FROM AUTHOR]

Local optical field modulation using plasmonic materials or photonic crystals provides a powerful strategy for enhancing upconversion emission of lanthanide-doped upconversion nanocrystals (UCNPs). However, it is restricted to static UC enhancement and the corresponding dynamic modulation of UC is yet to be reported, limiting its practical applications in information devices. Here, a dynamic UC modulation system is reported through electric stimulation by integrating UCNPs with electrically sensitive WO3_x plasmonic photonic crystals (PPCs). The tunable emission enhancement of UCNPs varying from five to 26 folds is achieved in WO3_x PPCs/UCNPs hybrids through external electric stimulation within +1.6 and _1.6 V. It stems from the reversible control of the photonic bandgaps and localized surface plasmon resonance of WO3_x PPCs, ascribed to the variation of refractive index and oxygen vacancy of WO3_x, induced by the reversible change of atomic ratio of W5+ to W6+ under different applied voltages. Moreover, the electrically triggered information encryption devices are developed, employing a programmable logic gate array based on WO3_x PPCs/UCNPs with the ability to convert information-encrypted electrical signals into visible patterns. These observations offer a new attempt to manipulate the UC and will simulate the new applications in the display and optical storage devices. [ABSTRACT FROM AUTHOR]

The development of phosphors with color-tunable luminescence including white emission is at the forefront of lighting and display technologies. Herein, Dy3+,Tm3+ single-doped or co-doped K3Y(PO4)2 phosphors are synthesized through the solid-state reaction method. By properly adjusting the ratio of Dy3+,Tm3+ co-doping concentrations, color-tunable luminescence from blue to yellow, including white luminescence, is realized under 359 nm excitation. The mechanism of energy transfer between Tm3+ and Dy3+ is further investigated via measuring the luminescence decay curve. Based on efficient energy transfer from Tm3+ to Dy3+, the emission of Dy3+ exhibits an abnormal thermal enhancement phenomenon as the temperature increases. The optical thermometry behaviors of various emission combinations for the Dy3+,Tm3+ co-doped system are analyzed. The maximum sensitivity can be obtained as a constant of 4.8 × 10−3 K−1, which is conducive to improve the measurement accuracy of optical temperature sensing at high temperatures. Furthermore, we also demonstrate the applicability of K3Y(PO4)2:Tm3+,Dy3+ phosphors in white LEDs, providing proof-of-concept for the lighting and display fields. [ABSTRACT FROM AUTHOR]

In order to reveal the community characteristics and trophic structure of oribatid mites in different moss habitats in karst caves, the oribatid mites in the moss habitats of ground (GD), understory (US), cave wall (CW), surface shrub (SB) and farmland (FL) outside the cave were collected in October 2021. Through the identification and data analysis of oribatid mites, 2352 oribatid mites were found, belonging to 45 families and 72 genera, most of which were Gymnonota. The family number, genus number, individual number, individual density, dominant genus composition, community diversity, community similarity, MGP (Analysis methods for ecological groups of oribatid mites) ecological group of oribatid mites and trophic structure of oribatid mites in different moss were analyzed. The results showed that: (1) The number of families, genera, individuals, and individual density of SB and FL are higher than those of the other three habitats; (2) Platyliodes, Oppiella, Tectocepheus, Scutovertex, Scheloribates and Trichogalumna are the dominant genera of the oribatid mites in the cave moss habitat, among them, Tectocepheus and Trichogaluna have the most obvious advantages; (3) The diversity index of shrub (SB) was higher than that of other four habitats; Similarity between ground and cave wall, shrub and farmland is high; (4) The MGP ecological group of oribatid mites in different habitats is dominated by O type (Overall type belongs to MGP analysis results, 20%≤M,G,P≤50%), and a total of 42 genera of oribatid mites preliminarily constitute the trophic structure of oribatid mites in the cave moss habitat. Based on the above results, it can be concluded that there are differences in the community structure of oribatid mites in different moss habitats in the study area, and the use of dominant genera of mites can preliminarily indicate the environmental conditions of different moss habitats. This study enriches the study of mites in karst cave mosses, and can provide theoretical significance for the protection of cave biodiversity in karst areas. [ABSTRACT FROM AUTHOR]

Red up-conversion luminescence with both emission and excitation peaks within the "tissue transparency window" makes for ideal fluorescent labels for deep tissue penetration and low-background biological imaging. In this work, an efficient strategy is proposed to realize bright red up-conversion luminescence based on interfacial energy transfer (IET), and the luminescence centers (Er3+ and Tm3+) and sensitizers (Yb3+) are doped in separate layers to avoid deleterious cross-relaxation. The IET process between Yb3+ and Er3+ can enable bright red photon up-conversion under 980 nm excitation via fine control and manipulation of the lanthanide ion concentration and shell thickness. By appropriately employing the fluorescence intensity ratio technique, an optical thermometer based on non-thermally coupled energy levels demonstrates a superior relative sensitivity of 2.02% K−1 across the whole temperature region. NaYF4:Er3+,Tm3+@NaYF4:Yb3+ with strong red UC luminescence and highly sensitive performance exhibits potential for application in the field of non-contact temperature sensing. [ABSTRACT FROM AUTHOR]

This research has been undertaken to reveal the changes in the community structure of epilithic moss mites and the response of these mites to environmental factors under different grades of rocky desertification environment. In this study, epilithic moss mites were collected in a demonstration area for rocky desertification management in Bijie Salaxi, with the following rocky desertification grades as habitat gradients: without rocky desertification, potential rocky desertification, light rocky desertification, moderate rocky desertification, and severe rocky desertification. The differences in the number of individuals, taxa, diversity index, dominance index, richness index, evenness index, and the effects of environmental factors on moss mite communities were revealed by one-way ANOVA, correlation analysis, and redundancy analysis for different grades of these mites. The results show that a total of 11,563 epilithic moss mites were captured in the study area, belonging to three orders, 100 families, and 171 genera, with Nanorchestes and Trichogalumna as the dominant taxa. With the deepening of rocky desertification, the dominant number of Nanorchestes and Trichogalumna increased. Still, the percentage of very rare genera also decreased, and there were differences in the composition of the dominant genus taxa in different grades of rocky desertification. Different grades of rocky desertification habitats had significant effects on the diversity index and richness index of moss mite species but not on the number of taxa, individuals, dominance index, and evenness index. The overall epilithic moss mite communities in different habitats were moderately dissimilar. Air temperature and rock temperature had strong effects on each index of moss mite diversity, whereas light factors and air humidity had a weak impact on these indices. Amongst the communities, those of Scheloribates are more sensitive to rock temperature variation, while Blattisocius, Ledermuelleria and Camerobia correlate more with a light variation. Parholaspulus, Blattisocius, Camerobia, Haplochthonius, Gymnodamaeus, etc. were more sensitive to changes in air humidity. The research shows that there are differences in moss mite community structure under different rocky desertification grades, rocky desertification has caused some effects on moss mite community structure, and the use of mite dominant taxa genera can give preliminary indications of the rocky desertification environment; meanwhile, there is a specific correlation between mite taxa and habitat environment changes. [ABSTRACT FROM AUTHOR]

The second near-infrared (NIR II) response photon up-conversion (UC) materials show great application prospects in the fields of biology and optical communication. However, it is still an enormous challenge to obtain efficient NIR II response materials. Herein, we develop a series of Er3+ doped ternary sulfides phosphors with highly efficient UC emissions under 1532 nm irradiation. β-NaYS2:Er3+ achieves a visible UC efficiency as high as 2.6%, along with high brightness, spectral stability of lights illumination and temperature. Such efficient UC is dominated by excited state absorption, accompanied by the advantage of long lifetimes (4I9/2, 9.24 ms; 4I13/2, 30.27 ms) of excited state levels of Er3+, instead of the well-recognized energy transfer UC between sensitizer and activator. NaYS2:Er3+ phosphors are further developed for high-performance underwater communication and narrowband NIR photodetectors. Our findings suggest a novel approach for developing NIR II response UC materials, and simulate new applications, eg., simultaneous NIR and visible optical communication. Development of efficient upconversion (UC) phosphors that emit under irradiation in the NIR II region is challenging - most UC materials rely on the presence of sensitizers absorbing at shorter wavelengths. Here, authors synthesize Er3+ doped ternary sulfides phosphors with visible UC efficiency up to 2.6% and long emission lifetimes under 1532 nm irradiation, via an excited state absorption mechanism. [ABSTRACT FROM AUTHOR]

Background and Purpose: Dopamine agonists targeting D2 receptor have been used for decades in treating pituitary adenomas. There has been little clear evidence implicating the canonical G protein signalling as the mechanism by which D2 receptor suppresses the growth of pituitary tumours. We hypothesize that β-arrestin2-dependent signalling is the molecular mechanism dictating D2 receptor inhibitory effects on pituitary tumour growth.Experimental Approach: The involvement of G protein and β-arrestin2 in bromocriptine-mediated growth suppression in rat MMQ and GH3 tumour cells was assessed. The anti-growth effect of a β-arrestin2-biased agonist, UNC9994, was tested in cultured cells, tumour-bearing nude mice and primary cultured human pituitary adenomas. The effect of G protein signalling on tumour growth was also analysed by using a G protein-biased agonist, MLS1547, and a Gβγ inhibitor, gallein, in vitro.Key Results: β-arrestin2 signalling but not G protein pathways mediated the suppressive effect of bromocriptine on pituitary tumour growth. UNC9994 inhibited pituitary tumour cell growth in vitro and in vivo. The suppressive function of UNC9994 was obtained by inducing intracellular reactive oxygen species generation through downregulating mitochondrial complex I subunit NDUFA1. The effects of Gαi/o signalling and Gβγ signalling via D2 receptor on pituitary tumour growth were cell-type-dependent.Conclusion and Implications: Given the very low expression of Gαi/o proteins in pituitary tumours and the complexity of the responses of pituitary tumours to G protein signalling pathways, our study reveals D2 receptor β-arrestin2-biased ligand may be a more promising choice to treat pituitary tumours with improved therapeutic selectivity. [ABSTRACT FROM AUTHOR]

Multicolor upconversion luminescence materials show significantly applications in materials science. In this paper, the novel Yb3+‐sensitized Na3La(VO4)2 upconversion luminescence crystals are synthesized by the solid‐state reaction method. Three primary colors upconversion luminescence are successfully achieved in Na3La(VO4)2:Yb3+,Tm3+, Na3La(VO4)2:Yb3+,Er3+, and Na3La(VO4)2:Yb3+,Ho3+ crystals excited by the single 980 nm LD. Multicolor upconversion luminescence can be obtained by simply adjusting the combination ratios of these three samples. Luminescence mechanisms of the Yb3+‐sensitized system are discussed in detail. In the Na3La(VO4)2 host material, the Yb3+/Ho3+ codoped system exhibits unusual red upconversion luminescence based on the short decay time of Ho3+ ion 5I6 level, which provides the possibility of three primary color luminescence under 980 nm excitation. [ABSTRACT FROM AUTHOR]

The development of noncontact thermal probe based on stable inorganic materials of trivalent lanthanide (Ln3+) doped phosphors with nontoxicity is of vital importance for their promising applications in bio‐medical fields. Here we explore the upconversion luminescence and thermal sensing properties of Er3+, Yb3+ co‐doped oxysulfide in a broad temperature range of 300‐583 K. It was found that constructing an active shell with an optimum concentration of sensitizers is an efficient way to improve both the luminescent intensities and thermal sensitivity. Compared with the core‐only sample, the luminescent intensity of the Y2O2S: Er3+, Yb3+@ Y2O2S: 5%Yb3+ sample is significantly enhanced by 12‐fold at excitation of 980 nm. While further increasing the Yb3+ concentration in the shell activates new quenching pathways of Er3+ → Yb3+ → quencher from the core to the shell. Similar quenching mechanisms are also observed at excitation of 1550 nm. These energy transfer processes and luminescence mechanisms are verified in the fluorescence decay measurements. Furthermore, coating the core sample with an active shell doped by 10% Yb3+ enhances the thermal sensitivity by 30%, holding a high and stable sensitivity more than 50 × 10−4 K−1 in a broad temperature range of 423‐573 K at 980 nm excitation. In addition, at the much safer excitation wavelength of 1550 nm, this sample achieved the maximum sensitivity of 45 × 10−4 K−1 at 503 K. Our work contributes a feasible and versatile way to promote the luminescence and thermal sensing properties of Ln3+‐based materials, combining with the nontoxic oxysulfide host, indicating their potential applications as safe fluorescent and temperature nano‐probes in bio‐field. [ABSTRACT FROM AUTHOR]

Uniform spindle‐like micro‐rods NaLa(WO4)2:Yb3+,Er3+ phosphors are prepared by the solvothermal method in the text. Controllable morphology of NaLa(WO4)2 crystal can be obtained by adjusting the prepared temperature, PH value, complexing agent content, and solvent ratio. Uniform NaLa(WO4)2:Yb3+,Er3+ micro‐rods of 1.8 μm in length and 0.5 μm in width are synthesized at a low temperature of 120°C. The prepared NaLa(WO4)2:Yb3+,Er3+ phosphors present green upconversion luminescence under 980 nm excitation, luminescence intensity reaches to maximum at the Yb3+ and Er3+ concentration of 6 and 2 mol%. The temperature performance of the NaLa(WO4)2:Yb3+,Er3+ phosphors are evaluated based on thermal coupling technology. Temperature dependence of the two green emissions ratio of Er3+ ion is obtained, and the sensitivity of the sample can be calculated, the maximum sensitivity of NaLa(WO4)2:Yb3+,Er3+ is up to 0.019 K−1 at the sample temperature of 564 K. [ABSTRACT FROM AUTHOR]

High color purity red emission with single band successfully achieved in a new Er 3+ , Tm 3+ co-doped Y 2 Ti 2 O 7 system under 1550 nm excitation, value of red to green emission ratio of the samples is more than 10 3 . Efficient up-conversion luminescence can be obtained while the 4 I 13/2 level of Er 3+ pumped by 1500 nm directly based on the large absorption section and long luminescence lifetime, and red emission composition will greatly enhanced by co-doping with Tm 3+ ions, color purity of red emission under 1550 nm excitation is much higher than that of 980 nm. The quenching concentration of Er 3+ ions is up to 28 mol% in Y 2 Ti 2 O 7 rely on the layer distribution of cations, which can further improve the red emission color purity. [ABSTRACT FROM AUTHOR]

The thermal effects of Er/Yb-doped NaYF4 phosphor induced by 980/1510 nm laser diode irradiation were intuitively and contrastively investigated using an infrared thermal imaging technology with real-time online monitoring. The Yb3+/Er3+ codoped materials have strong thermal effects and high-temperature elevation under 980 nm irradiation. However, the severe thermal effects of materials with higher Er3+ ion doping concentration are remarkably attributed to the cross relaxation between the Er3+ ions under 980 nm irradiation. The energy transfer between Er3+ and Yb3+ ions in Er3+/Yb3+-codoped materials also contributes to the thermal effects under 1510 nm laser diode irradiation. Under the same testing conditions, the temperature elevation ∆T of samples induced by 1510 nm laser diode irradiation is lower than that induced by 980 nm laser diode irradiation. The temperature rising rate and elevation ∆T value of samples depend on the ion doping concentration and power density of the laser diode excitation. The internal temperature of the samples exhibits deep temperature gradient under 980/1510 nm laser diode irradiation. By comparing the two kinds of thermometry methods, the temperature value calculated by fluorescence intensity ratio is almost similar to that obtained through infrared thermal imaging technology under higher excitation power pumping. [ABSTRACT FROM AUTHOR]

The thermal effects of NaYF4:Er microcrystals under 1550 nm laser diode irradiation were investigated using an infrared thermal imaging method. The results revealed that the temperature of the LD irradiation beam area was non-uniform. The NaYF4:Er sample exhibits a rapid temperature increase within 5–10 s, and the heating process reaches its steady state after 60 s of irradiation when exposed to 1550 nm LD. The response time, temperature increase, and emission intensity of the samples depend on the excitation power density and concentration of doped Er3+ ions. Low excitation power density is required to avoid the influence of thermal effects on the up-conversion emission spectra measurement. Rapid scanning in up-conversion emission spectra measurement is not effective in preventing the heating effect under high excitation power pumping. In addition, a relative deviation of temperature, existing in fluorescence intensity ratio technique, decreased with the increasing irradiation time. [ABSTRACT FROM AUTHOR]