Red Intensity Research Articles

Development of Plant-Based Burgers with Partial Replacement of Texturized Soy Protein by Agaricus bisporus: Effects on Physicochemical and Sensory Properties

This study aims to develop plant-based burgers with partial replacement of texturized soy protein (TSP) by Agaricus bisporus mushrooms at proportions of 5%, 10%, 15%, and 20%. The substitution was evaluated regarding its impact on the burgers’ chemical composition, texture, color, cooking performance, and sensory properties. Chemical analyses showed a significant increase in moisture content starting from the 10% substitution level, contributing to improved juiciness. Protein content remained similar to the control until the 15% substitution level, while the fat content showed no significant variation among treatments. The texture profile indicated reduced hardness in burgers with mushroom enrichment, particularly at 5% and 10%, leading to a more tender product. Color analysis revealed a reduction in lightness (L*) and red intensity (a*) with increased mushroom levels. Sensory analysis showed that burgers with up to a 15% substitution level maintained consumer acceptance comparable to the control, with attributes such as “softness”, “pleasant color”, and “good appearance” positively correlated with consumer acceptance. The findings indicate that Agaricus bisporus mushrooms can be effectively used as a partial substitute for TSP in plant-based burgers, enhancing sensory properties without compromising quality. This substitution offers a promising approach to diversifying ingredients in plant-based products while maintaining desirable characteristics for consumers.

Antibacterial Effects of Black Cumin Seed Oil on Oral Microcosm Biofilms.

Interest in natural extracts for managing oral biofilms is increasing, with black cumin seed oil (BCSO) demonstrating efficacy against Streptococcus mutans. The effectiveness of antibacterial agents should be evaluated using multi-species oral biofilm models that closely mimic actual conditions. This study aimed to compare the antibacterial effects of BCSO and chlorhexidine gluconate (CHX) on oral microcosm biofilms. Biofilms using human saliva as the inoculum were cultured for 2 days and subsequently treated with 0.5% dimethyl sulfoxide, 0.5% BCSO, or 0.12% CHX once daily for 6 days. Following treatment, the red fluorescence intensity (RatioR/G) of the oral biofilm; biomass, including extracellular polymeric substance (EPS) levels and live bacteria counts; and colony-forming units (CFUs) of aciduric bacteria were evaluated. RatioR/G after BCSO treatment (1.26 ± 0.03) was not significantly different from that after CHX treatment (p = 0.552). The EPS levels were also not significantly different between the two groups (p = 0.743). The live bacteria count was 0.55 times lower in the BCSO-treated group than in the CHX-treated group (p = 0.018). No significant between-group difference was observed in the CFUs of aciduric bacteria (p = 0.935). These results suggest that BCSO exhibits antibacterial effects similar to those of CHX, highlighting its potential as an effective alternative.

Pterin-Based Red Coloration Predicts the Outcome of Male-Male Competition in Guinan Toad-Headed Lizard.

Animal coloration offers a unique opportunity to explore the evolutionary mechanisms underlying phenotypic diversity. Conspicuous coloration caused by pigments plays a crucial role in social signaling across multiple species by conveying information about individual quality, social ranks, or reproductive condition. Nevertheless, most previous studies have focused predominantly on colors produced by the exogenous pigments-carotenoids. Pterins are another prevalent group of conspicuous pigments, which can be produced endogenously and have received comparatively little attention. Whether pterin-based colors represent reliable signals remains elusive. The remarkable red ventrolateral coloration exhibited by males of the Guinan toad-headed lizard (Phrynocephalus guinanensis) in the Mugetan Desert presents an ideal model for investigating pterin-based coloration. Through electron microscopy and metabolomic identification, we discovered three types of pterin pigments within xanthophores. Integrating a series of morphological measurements and behavioral experiments, we found that this red coloration was not correlated with body size, bite force, and testosterone level, nor did females show a preference bias toward it. However, the red intensity predicted male-male competition outcomes, with deeper red males being more likely to emerge as winners. Our results indicated that the pterin-based coloration could convey information about male quality, suggesting its potential role in honest signaling, given the vital importance of pterin metabolism in physiological processes. This study provides a novel case into the understanding of pterin-based colors in animals.

Preparation and significant enhancement of upconversion luminescence of α-Ba2ScAlO5:Yb3+/Er3+ phosphors by Ca2+ ions doping

The intensity of upconversion luminescence (UCL) poses a significant challenge for oxides characterized by high phonon energy. Herein, a significant enhancement of red UCL is achieved through the introduction of an intermediate band (IB) in α-Ba2ScAlO5: Yb3+/Er3+ by Ca2+ ions doping. The absorption spectra verify the existence of the IB. The IB of α-Ba2ScAlO5: Yb3+/Er3+/Ca2+ increases the host's absorption of excited photons, provides more electrons for the excitation of Er3+, and realizes the enhancement of UCL emission. The optimal concentration of Ca2+ in α-Ba2ScAlO5: 0.2Yb3+, 0.03Er3+ is 0.15. Compared with undoped Ca2+ samples, the red and green UCL intensity of α-Ba2ScAlO5: Yb3+, Er3+, 0.15Ca2+ increased by 48.2 and 10.6 times, respectively. The mechanism of Ca2+ enhanced UCL was investigated by analyzing the UCL spectra, absorption spectra and lifetime decay curves of α-Ba2ScAlO5: Yb3+/Er3+/Ca2+. The temperature-dependent UCL properties of α-Ba2ScAlO5: Yb3+/Er3+/Ca2+ were also studied by the 2H11/2 (525 nm) and 4F9/2 (667 nm) energy level radiation transitions. The observed linear correlation between luminescence intensity and temperature, coupled with its high sensitivity, indicates the promising potential for temperature sensing applications. This study not only opens a new avenue for enhancing UCL but also holds significant implications for sparking widespread interest in non-contact temperature sensing applications leveraging UCL.

Modulation of AIE and Intramolecular Charge Transfer of a Pyrene-Based Probe for Discriminatory Detection and Imaging of Oligomers and Amyloid Fibrils.

Oligomers and amyloid fibrils formed at different stages of protein aggregation are important biomarkers for a variety of neurodegenerative diseases including Alzheimer's and Parkinson's diseases. The development of probes for the sensitive detection of oligomeric species is important for early stage diagnosis of amyloidogenic diseases. Many small molecular dyes have been developed to probe the dynamic growth of amyloid fibrils. However, there is a lack of discriminatory detection strategies to monitor the dynamics of both oligomers and amyloid fibrils based on the differential modulation of the photophysical properties of a single dye. Here we report a pyrene-based intramolecular charge transfer (ICT) dye with large Stokes shifted red-emitting aggregation induced emission (AIE) for monitoring the dynamic populations of both oligomers and fibrils during the aggregation of hen egg white lysozyme (HEWL) protein. At the early stage of protein aggregation, the accumulation of HEWL oligomers results in a rapid and substantial increase in the red AIE intensity at 660 nm. Later, as the oligomers transform into mature fibrils, the dye exhibits a distinct photophysical change. Binding of the dye to HEWL fibrils strongly suppresses the red AIE and enhances ICT emission. This is evidenced by a gradual decrease in the AIE intensity (∼660 nm) and an increase in LE (∼490 nm) and ICT (∼540 nm) emission intensities during the later stages of protein aggregation. Thus, the dye provides simultaneous measurements of the population dynamics of both HEWL oligomers and fibrils during protein aggregation based on the discriminatory modulation of AIE and ICT of the dye. The dye also enables imaging of both HEWL oligomers and fibrils simultaneously using different emission channels in super-resolution confocal fluorescence microscopy.

Unveiling dynamic alterations of lipid droplet polarity during NAFLD-triggered lipophagy utilizing a far-red fluorescent probe with large stokes shift

Lipophagy as a form of autophagy, can degrade lipid droplets, thereby acting as a critical regulator of cellular lipid metabolism, helping maintain the intracellular lipid homeostasis. In this study, we developed LP-SCUN, a far-red fluorescent probe for pinpointing lipid droplets with high sensitivity to solvent polarity. This probe allows for in situ imaging of lipophagy, tracking how lipid droplets move from non-polar to polar environments within lysosomes, leading to noticeable changes in fluorescence signals. The triphenylamine and triethylene glycol monomethyl ether groups of LP-SCUN facilitated its selective binding toward lipid droplets. Significantly, lipophagy and subsequent formation of autolysosomes decreased the environmental polarity, leading to a significant decrease in red fluorescence intensity (λex = 500 nm and λem = 643 nm). As such LP-SCUN was suitable for the in situ and real-time tracking of the cellular lipophagic processes. With this research we used LP-SCUN to elucidate the mechanism of lipid metabolism in liver cells of palmitate-induced hyperlipidemia cell models and high-fat diet-induced hyperlipidemia animal models. The results indicated that non-alcoholic fatty liver disease (NAFLD) can trigger an increase in cell lipophagy levels, while the inhibition of cell lipophagy can effectively alleviate the damage caused by NAFLD to cells and liver tissue in mice.

Evaluating Osteogenic Cell Differentiation Efficacy in the Presence of Polylactide Samples With Varied Compositions for Bone Grafting: In Vitro Study.

In oral implantology, surgeons often confront the need to improve alveolar bone quality and volume before implantation in patients with bone defects. Whereas guided bone regeneration with titanium meshes is a clinical gold standard for bone augmentation, mesh removal pre-implantation presents a drawback. This study explores biodegradable scaffolds as an alternative. The research investigates the impact of various compositions of customized bone-grafting scaffolds on proliferation and osteogenic differentiation processes in vitro. Plates (10 × 10 × 0.5 mm) were fabricated from polylactide (PLA), PLA with 15% hydroxyapatite nanoparticles (PLA/HA), and polylactide with glycolic acid copolymers (PLGA 60:40 and 85:15). Gingival fibroblasts assessed the influence of experimental samples on proliferation and osteogenic differentiation in a low-glucose medium. Osteogenic differentiation was induced, and alizarin red staining measured extracellular matrix calcification via spectrophotometry. Active proliferation of gingival fibroblasts occurred along scaffold edges during cultivation. Although cells proliferated with experimental samples, rates were lower than control cells. PLA/HA showed higher alizarin red staining intensity, indicating enhanced matrix calcification. Experimental samples (PLA, PLA/HA, PLGA 85:15, PLGA 60:40) supported cell proliferation at lower rates than control. PLA/HA demonstrated increased matrix calcification. Biodegradable membranes were nontoxic, suggesting potential for bone augmentation.

Analyzing Medicago spp. seed morphology using GWAS and machine learning

Alfalfa is widely recognized as an important forage crop. To understand the morphological characteristics and genetic basis of seed morphology in alfalfa, we screened 318 Medicago spp., including 244 Medicago sativa subsp. sativa (alfalfa) and 23 other Medicago spp., for seed area size, length, width, length-to-width ratio, perimeter, circularity, the distance between the intersection of length & width (IS) and center of gravity (CG), and seed darkness & red–green–blue (RGB) intensities. The results revealed phenotypic diversity and correlations among the tested accessions. Based on the phenotypic data of M. sativa subsp. sativa, a genome-wide association study (GWAS) was conducted using single nucleotide polymorphisms (SNPs) called against the Medicago truncatula genome. Genes in proximity to associated markers were detected, including CPR1, MON1, a PPR protein, and Wun1(threshold of 1E−04). Machine learning models were utilized to validate GWAS, and identify additional marker-trait associations for potentially complex traits. Marker S7_33375673, upstream of Wun1, was the most important predictor variable for red color intensity and highly important for brightness. Fifty-two markers were identified in coding regions. Along with strong correlations observed between seed morphology traits, these genes will facilitate the process of understanding the genetic basis of seed morphology in Medicago spp.

Development and characterization of innovative bio-based edible films supplemented with cell-free supernatant and whole-cell postbiotic of Lactobacillus gasseri

More recently, the concepts of cell-free supernatants (CFS, so-called postbiotics) and whole-cell postbiotics (WCP) of probiotics have gained increasing attention for the development of bio-based films. However, reports on CFS and WCP of Lactobacillus gasseri remain scarce. In this study, pea protein isolate/psyllium mucilage was incorporated with CFS and WCP of L. gasseri to produce bio-based edible films. pH, total soluble solid content, antioxidant activity, total phenolic content, antimicrobial activity, and structural analyses were conducted to characterize the CFS and WCP of L. gasseri. Furthermore, the effects of CFS (10% and 20%, v/v) and WCP (10% and 20%, v/v) on the physicochemical, mechanical, barrier, optical, microstructural, and antimicrobial properties of the bio-based films were investigated. The results showed that CFS and WCP exhibited antioxidant and antibacterial activities and were significant sources of phenolic compounds. The incorporation of 20% WCP caused a significant increase in the thickness and water vapor permeability of films, while a significant increase in moisture content was observed with 10% WCP. The control and 10% WCP films had the highest tensile strength values. Furthermore, the addition of 10% WCP resulted in a significant increase in elasticity. Films incorporating CFS and WCP exhibited lower opacity values and darker, yellow, and red color intensities. The addition of CFS and WCP caused a rough texture and cracked structure on the surface of the film. In conclusion, pea protein/psyllium mucilage-based films containing CFS and WCP of L. gasseri can be considered as a new alternative for environmentally friendly bio-based films.

Preparation and anti-counterfeiting application of Sr3Y2Ge3O12:Bi2+ red long afterglow luminescent

Red, as one of the three primary colors, is crucial for blending the luminescent color of long-lasting materials. This project selected Sr3Y2Ge3O12 as the substrate and Bi2+ as the activator. A solid-state method at high temperature was used to prepare a new type of visible red long-afterglow luminescent material, by adjusting the doping concentration of Bi2+ and changing the calcination temperature. When the doping concentration of Bi2+ was 0.50mol% and the calcination temperature was 1150 °C, the prepared Sr3Y2Ge3O12:Bi2+ had the best luminescent properties. After being excited by 254 nm ultraviolet light, the material shows the red afterglow luminous intensity, duration and stability that meet the practical application requirements. Through thermoluminescence, photoluminescence and fluorescence spectra, the trap characteristics and internal mechanism of long afterglow were studied comprehensively. Finally, the film and printing ink were prepared by using the Sr3Y2Ge3O12:Bi2+ long afterglow luminescent powder with the best luminescent performance, and the pattern anti-counterfeiting was successfully realized.

Synthesis, infra red and nmr intensities of amphiphilic adamantane derivatives: Impact of hydroxylation, acetylation and chlorination

Novel chloro substituted adamantanamide was designed to have better supramolecular sites and accordingly synthesized via hydroxylation, acetylation and chlorination. Due to the specific electronic properties of chlorine atom it imparts better applications. Functionalization of highly unreactive adamantane was achieved with an overall yield of 80% under milder reaction conditions. Hydroxylation of adamantamine was carried out using urea as catalyst (10mol%) with an yield of 97%. Acetylation was optimized using acylating reagent (acetyl chloride, 1.1 equivalents) and DIPEA (1.5 equivalents) which resulted 97% yield. Finally, chlorination was carried out with thionyl chloride (2.0 equivalents) at 65 °C (84% yield). IR and NMR (including D2O exchanded) spectra were analyzed along with ESI-MS data of all the products. DFT studies were carried using B3LYP level {6–311++G (d, p) basis set}out for all the products to predict the stability, reactivity and other global descriptors.

Ultrasensitive and selective colorimetric and smartphone-based detection of arsenic ions in aqueous solution using alliin-chitosan-AgNPs.

In this study, we developed a highly selective and sensitive colorimetric sensor for arsenic [As(iii)] detection using alliin-chitosan-stabilized silver nanoparticles (AC-AgNPs). The AC-AgNPs were synthesized using a complex prepared by mixing aqueous garlic extract containing alliin and chitosan extracted from shrimp. The synthesis of AC-AgNPs was confirmed by UV-vis spectroscopy, which showed a surface plasmon resonance (SPR) band at 403 nm, and TEM analysis revealing spherical nanoparticles with a mean diameter of 7.57 ± 3.52 nm. Upon the addition of As3+ ions, the brownish-coloured solution of AC-AgNPs became colourless. Moreover, the computational study revealed that among all the metal ions, only As3+ was able to form a stable complex with AC-AgNPs, with a binding energy of 8.7 kcal mol-1. The sensor exhibited a linear response to As(iii) concentrations ranging from 0.02 to 1.4 fM, with a detection limit of 0.023 fM. The highest activity was observed at pH 7 and temperature 25 °C. Interference studies demonstrated high selectivity against common metal ions. The study also demonstrated that the concentration of As3+ ions can be estimated by the decrease in red intensity and increase in green intensity in smartphone optical transduction signals. These results indicate the potential of the AC-AgNP-based sensor for reliable and efficient arsenic detection in environmental monitoring.

Self-Internal Standard Fluorescence for Ultrasensitive Detecting of mtDNA to Evaluate Matrilineal Genetic Defect Levels.

Mitochondrial DNA (mtDNA) is a unique genetic material characterized by maternal inheritance. It possesses a circular structure devoid of histone protection and exhibits low cellular abundance, which poses great challenges for its sensitive and selective detection at the living cell level. Herein, we have designed three bis-naphthylimide probes with varying linker lengths (NANn-OH, n = 0, 2, 6), facilitating the formation of distinct twisted or folded molecular conformations in the free state. These probes emit the red fluorescence around 627 nm with different fluorescence quantum yields (ΦNAN0-OH = 0.0016, ΦNAN2-OH = 0.0136, and ΦNAN6-OH = 0.0125). When encountering mtDNA (0.4-3.4 μg/mL), these probes undergo conformational changes depending on the length of the attached C-strand and exhibit a gradually increasing fluorescence signal around 453 nm. The fluorescence intensity increased to 13.5-fold, 1.9-fold, and 8.2-fold, respectively. Notably, the red fluorescence intensities around 627 nm remain constant throughout this process, thus serving as an inherent correction mechanism for proportional fluorescence signal enhancement to improve selectivity and sensitivity. NAN0-OH, NAN2-OH, and NAN6-OH showed good linearity for mtDNA in the range of 0.4-3.4 μg/mL with detection limits of LODNAN0-OH = 1.04 μg/mL, LODNAN2-OH = 1.10 μg/mL, and LODNAN6-OH = 1.15 μg/mL. Cellular experiments reveal that NAN6-OH effectively monitors curcumin-induced mtDNA damage in HepG-2 cells while enabling monitoring of genetic mtDNA damage. We anticipate that this tool holds significant potential for the precise evaluation of maternal genetic defects, thereby enhancing hypersensitive assessment in clinical medicine.

Cation Occupation Engineering Realizes Valence Modulation of Manganese-Activated ZnGa2O4.

Herein, a series of Mn-activated ZnGa2O4 (ZGO) phosphors have been developed for multifunctional applications. The characteristic green and red emission at 503 and 668 nm of Mn-activated ZGO phosphors can be observed under excitation of 247 and 375 nm, respectively, attributed to the partial oxidation of Mn2+ ions resulting in the coexistence of Mn2+ and Mn4+ ions in the host lattice. The valence modulation of Mn content not only realizes the adjustment of red and green luminescence intensity but also achieves the management of persistent luminescence time and thermo-luminescence time. Further, the codoping of Mg2+ could transform the position occupancy preference of Mn and effectively facilitate the conversion of Mn2+ to Mn4+, leading to the regulation of the valence state of manganese ions. Surprisingly, the existence of Mg2+ ions broadens the emission band of Mn4+ and enhances the photoluminescence intensity to 3.8 times, which can be ascribed to the weakened crystal field leading to the downward shift of the 4T2 energy level and the increase of Mn4+ concentration. For this valence modulation behavior, two different hypotheses about the occupancy of Mg2+ have been proposed to explain the corresponding phenomenon. Finally, the potential applications of the synthesized phosphors have been explored in advanced anticounterfeiting strategies, information storage, and plant lighting field.

Distinguishing discolored caries lesions using biofluorescence and dental bleaching: An in vitro simulation model study

BackgroundDistinguishing between discoloration caused by caries and organic stains is challenging for dentists in clinical settings. Biofluorescence (BF)-bleaching assesses caries lesions by evaluating BF changes after removing organic stains through dental bleaching, leaving cariogenic discoloration. This study aimed to apply BF-bleaching to a simulation model mimicking cariogenic discoloration and compare the BF color changes between organic staining and cariogenic discoloration. MethodsThirty artificial caries lesions in bovine incisors were equally divided into three groups: non-stained (NS), organic-stained (OS), and cariogenic-stained (CS) groups. The specimens were treated with bleaching agent, then BF color of each specimen was evaluated using red BF intensity (ΔR), BF hue angle (h°), and hyperspectral BF spectrum. ResultsThe ΔR of CS was approximately 2.74 and 1.73 times higher than that of OS, at baseline and after bleaching for 20 min, respectively. After 20 min of bleaching, the h° of CS increased by approximately 8.1° compared to the baseline, while maintaining the red BF hue range (345‒15°). In contrast, the BF hue of OS shifted from orange (15‒45°) to yellow (45‒75°) simultaneously, and the h° change was approximately 21.9°. Both CS and OS exhibited first emission peaks near 515 nm, and CS showed second peaks in the red range (620‒780 nm). After bleaching, the first peaks were restored to the sound enamel direction (peak at 486 nm), whereas the second peaks of red BF in CS were maintained. ConclusionApplying BF-bleaching to discolored caries lesions allowed differentiation between cariogenic discoloration and organic staining based on BF color changes.

Quantification and visualization of penicillin G residues in milk using a ratiometric fluorescent nanoprobe based on carbon dots and gold nanoclusters

Developing an effective assay for monitoring penicillin G (PNG) is important for safeguarding ensuring public health and food safety. This work details the application of carbon dots (CDs) emitting blue light and gold nanoclusters (GNCs) with red emission as ratiometric fluorescence (RF) probes for the sensitive detection of PNG. The RF probe under a single excitation of 360 nm wavelength displayed two discrete emission peaks at 444 and 660 nm related to CDs and GNCs, respectively. Following the introduction of PNG, the red fluorescence intensity of GNCs was found to be reduced through the inner filter effect (IFE); meanwhile, the blue fluorescence of CDs remained unchanged under optimal conditions. The quantification of PNG can be achieved by this RF nanoprobe by following the I660/I444 ratio in two ranges of 0.1–0.8 ppm and 0.8–30.0 ppm and with a limit of detection (LOD) as low as 30 ppb. Furthermore, the RF probe has been successfully employed to determine PNG in milk samples with acceptable recoveries and results were validated by HPLC. Finally, the visual capability of this RF probe can greatly enhance and facilitate on-site determination process of PNG.

Non-contact leaf wetness measurement with laser-induced light reflection and RGB imaging

Leaf wetness duration is a crucial factor in plant disease management. Current optical methods use standard RGB images to classify leaf wetness as a binary problem, i.e., wet or dry. Green leaves absorb red light, whereas water reflects it. Based on this difference, an experimental platform was built to semi-automatically measure droplet deposition on grape leaves while capturing red laser images using an RGB camera. The setup measured changes in leaf mass and area of scanned leaves to determine the water mass per leaf area as a measure of leaf wetness. A sprayer was used to apply water droplets to the leaves. As the amount of deposited water increased, the mean red channel intensity decreased, with more bright spots in the images. These bright spots were more distinguishable as droplets in the green channel. Segmented leaf area, mean red channel intensity, and the number of identified droplets were used as image features. A generalised additive model was employed to predict the leaf wetness value with extracted features. The R-squared value for the prediction of the validation dataset was 0.71. Image resolution and leaf orientation were identified as factors that influenced the model accuracy. The measurement method introduced in this study shows potential for accurately quantifying leaf wetness, and implies that in practice detecting leaf wetness can be integrated into a multi-classification problem, thereby broadening the potential applications of optical methods.

Clove essential oil decreases antemortem stress and acts as an antioxidant in Nile tilapia

ABSTRACT This study investigated the effect of clove essential oil used prior to stunning by cranial percussion and hypothermia on Nile tilapia (Oreochromis niloticus) welfare and fillet quality. A total of 100 tilapias were divided into four groups in a 2 × 2 factorial design, exploring two stunning methods with and without clove essential oil. Behavioral responses, glucose, lactate, pH, water holding capacity, color parameters, lipid and protein oxidation, and oxidative stress were analyzed. The application of clove essential oil resulted in 100% numbing in swimming and stimulus response behaviors, and 96% in balance and eye vestibule reflex variables. Significant reductions in glucose (12.12 mg dL−1) for hypothermia group (p = 0.001) and lactate (3.36 mmol L−1) for cranial percussion (p = 0.004), 0.028 nmol lipid oxidation in hypothermia treatment (p = 0.009), and 0.134 nmol carbonyls/mg protein (p = 0.001) were observed. There was a reduction in luminosity (p = 0.010) and red intensity (p = 0.001) in the group of fish fillet that received cranial percussion, however, there was no difference in the group stunned by hypothermia. Clove essential oil demonstrates effectiveness in pre-slaughter stress mitigation, influencing the antioxidant system positively. Its usage in pre-slaughter protocols could contribute to improved fillet quality, presenting a promising alternative for enhancing tilapia welfare during slaughter.

Significantly enhanced upconversion luminescence intensity and tailorable chromaticity of Sn4+-doped NaYF4:Yb3+/Er3+

The internal modification with rare earth ion doping proved to be a very effective strategy for improving the luminescent properties of NaYF4-based upconversion materials. However, greatly enhancing the luminescence efficiency of NaYF4:Yb3+/Er3+ remains a major challenge. Herein, the effects of Sn4+ doping on the structure and luminescent performance of such material were explored. The hydrothermal molten-salt method was applied to synthesize the Sn4+-doped NaYF4:Yb3+/Er3+ upconversion materials, and their crystal structures, morphologies, surface chemical composition and element states, and luminescence performance were characterized. It was found that Sn4+ doping can significantly enhance the luminescence intensity and tailor the chromaticity of NaYF4:Yb3+/Er3+. In particular, the green (G) and red (R) luminescence intensity levels of the 30 mol% Sn4+ doped material were increased by factors of 26.97 and 38.91, respectively. The R/G ratio was incremented from 0.34 for the undoped material to 0.83 for the 40 mol% Sn4+ doped counterpart. The Sn4+ doping led to the change of lattice distortion and crystal growth pattern of NaYF4:Yb3+/Er3+. The mechanism for Sn4+ doping to affect the luminescence properties of the prepared upconversion material was also explored. The changes in luminescence intensity levels and R/G ratios could be attributed to the highly asymmetric distorted lattice and crystal field resulting from Sn4+ doping.

Evolutionary lability of food caching behaviour in mammals.

Food hoarding provides animals access to resources during periods of scarcity. Studies on mammalian caching indicate associations with brain size, seasonality and diet but are biased to a subset of rodents. Whether the behaviour is generalizable at other taxonomic scales and/or is influenced by other ecological factors is less understood. Population density may influence food caching due to food competition or pilferage, but this remains untested in a comparative framework. Using phylogenetic analyses, we assessed the role of morphology (body and brain size), climate, diet breadth and population density on food caching behaviour evolution at multiple taxonomic scales. We also used a long-term dataset on caching behaviour of red squirrels (Tamiasciurus fremonti) to test key factors (climate and population density) on hoarding intensity. Consistent with previous smaller scale studies, we found the mammalian ancestral state for food caching was larderhoarding, and scatterhoarding was derived. Caching strategy was strongly associated with brain size, population density and climate. Mammals with larger brains and hippocampal volumes were more likely to scatterhoard, and species living at higher population densities and in colder climates were more likely to larderhoard. Finer-scale analyses within families, sub-families and tribes indicated that the behaviour is evolutionary labile. Brain size in family Sciuridae and tribe Marmotini was larger in scatterhoarders, but not in other tribes. Scatterhoarding in tribe Marmotini was more likely in species with lower population densities while scatterhoarding in tribe Sciurini was associated with warmer climates. Red squirrel larderhoarding intensity was positively related to population density but not climate, implicating food competition or pilferage as an important mechanism mediating caching behaviour. Our results are consistent with previous smaller-scale studies on food caching and indicate the evolutionary patterns of mammalian food caching are broadly generalizable. Given the lability of caching behaviour as evidenced by the variability of our results at finer phylogenetic scales, comparative analyses must consider taxonomic scale. Applying our results to conservation could prove useful as changes in population density or climate may select for different food caching strategies and thus can inform management of threatened and endangered species and their habitats.