Accordingly, phosphor-converted (pc) NIR light-emitting diodes (LEDs) have received extensive scientific attention as lighting sources, owing to their conspicuous characteristics and range of applications. [8] The integration of blue InGaN LED chips with NIR phosphors is considered a promising strategy for yielding novel high-performance NIR light sources with broadband spectra. [9][10][11][12] Since NIR phosphors are key parts of these devices, affecting their overall luminescence performance and emission spectrum, selecting the appropriate phosphor is paramount. In this regard, for the design of efficient broadband NIR phosphors, applying a suitable activator as an ideal luminescence center is of vital importance.Chromium (Cr) exhibits a broadband absorption in the visible spectral range stemming from its distinctive 3d 3 electronic configuration. Besides, Cr 3+ ions can display a tunable narrowband or broadband spectrum (from deep red to the NIR region) depending on whether they are in a strong or weak crystal field environment, respectively. [9][10][11] Correspondingly, garnets possess a stable cubic crystal structure with a complex arrangement of different cations in the unit cell and exhibit several advantages, including a high thermal stability and long distances between alkali ions. The specific physicochemical Broadband near-infrared (NIR) luminescent materials have received notable attention due to their distinct photophysical properties for designing NIR light-emitting diodes (NIR LEDs). Here, a series of Ca 3−x Lu x Ga 2+x Ge 3−x O 12 :Cr 3+ (CLGGG:Cr 3+ ) (x = 0-1) NIR-emitting garnet phosphors with an emission range of 660-1200 nm are successfully developed and their lattice parameters are structurally analyzed. Upon 460 nm blue light excitation, the NIR phosphors exhibit both a substantial spectral broadening (FWHM: 129→267 nm) and a redshift of 37 nm (766→803 nm) with cosubstitution of [Lu 3+ -Ga 3+ ] pairs for [Ca 2+ -Ge 4+ ] sites. Furthermore, their luminescence thermal stability is substantially improved, maintaining ≈90% of the original photoluminescence intensity at 150 °C, owing to shrinkage of the second coordination sphere and rigid lattice, which are strongly associated with Cr 3+ trade-off occupancy and local structure evolutions. The relation between the trade-off site occupation of Cr 3+ in GaO 6 /CaO 8 polyhedrons and the NIR emission is also clarified by evaluating the decay and electron paramagnetic resonance behavior of Cr 3+ at different sites. The broadband NIR phosphors investigated here can serve as auspicious luminescent converters for phosphor-converted NIR LEDs and can provide an inspiring platform for future studies.
Dynamic regulation of intestinal epithelial cell (IEC) differentiation is crucial for both homeostasis and the response to helminth infection. SIRT6 belongs to the NAD+-dependent deacetylases and has established diverse roles in aging, metabolism and disease. Here, we report that IEC Sirt6 deletion leads to impaired tuft cell development and type 2 immunity in response to helminth infection, thereby resulting in compromised worm expulsion. Conversely, after helminth infection, IEC SIRT6 transgenic mice exhibit enhanced epithelial remodeling process and more efficient worm clearance. Mechanistically, Sirt6 ablation causes elevated Socs3 expression, and subsequently attenuated tyrosine 641 phosphorylation of STAT6 in IECs. Notably, intestinal epithelial overexpression of constitutively activated STAT6 (STAT6vt) in mice is sufficient to induce the expansion of tuft and goblet cell linage. Furthermore, epithelial STAT6vt overexpression remarkedly reverses the defects in intestinal epithelial remodeling caused by Sirt6 ablation. Our results reveal a novel function of SIRT6 in regulating intestinal epithelial remodeling and mucosal type 2 immunity in response to helminth infection.
Avian reovirus (ARV) is the primary pathogen responsible for viral arthritis. In this study, 2340 samples with suspected viral arthritis were collected from 2019 to 2020 in 16 provinces of China to investigate the prevalence of ARV in China and to characterize the molecular genetic evolution of epidemic strains. From 113 samples analyzed by RT-PCR, 46 strains of avian reovirus were successfully isolated and identified. The genetic evolution of the σC gene showed that 46 strains were distributed in 1–5 branches, with the largest number of strains in branches 1 and 2. The σC gene homology among the strains was low, with approximately 62% homology in branches 4 and 5 and about 55% in the remaining branches. The strains circulating during the ARV epidemic in different provinces were distributed in different branches. The SPF chickens were immunized with inactivated vaccines containing strains from branches 1 and 4 to analyze the cross-immune protection elicited by different branches of ARV strains. A challenge protection test was performed using strains in branches 1, 2, 4, and 5. Our results showed that inactivated vaccines containing strains from branches 1 and 4 could fully protect from strains in branches 1, 4, and 5. The results of this study revealed the genetic diversity among the endemic strains of ARV in China from 2019 to 2020. Each genotype strain elicited partial cross-protection, providing a scientific basis for the prevention and control of ARV.
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