Blue Research Articles

Blue Boys: Maurice Pialat, Nicolas Poussin and the Work of Art

Maurice Pialat (1925–2003) in his Libération article “Éloge de Poussin” (1987) tells us that cinema has made no progress since the Lumière brothers’ first projected images. Provocatively, he informs his readers that only painting has progressed and, as such, remains the far more innovative art form. For all the pointed remarks directed with some force towards French film critics and filmmakers, Pialat’s short notes in Libé offer us something more. It is one of the few opportunities to consider the auteur’s critical and aesthetic approaches to filmmaking. While Pialat emphasises the failure of critics and filmmakers to elevate cinema to the level of art, the article more saliently invites us to analyse Pialat’s understanding of cinematic practice as an intricate enfolding of painterly and cinematic concepts. In this article I contend that, through a reading of the theoretical dimensions Pialat introduces in his “elegy” to the Classicist painter Nicolas Poussin (1594–1665), along with an analysis of a selection of the director’s films, we not only discover Pialat’s film-philosophy; moreover, we discover new ways to study Pialat’s acute rendering of fraught manhood. Significantly, I argue, Pialat’s wrestling with masculinity (fatherhood, sexual desire, boyhood, and so on) reveals itself through a key element critical to Poussin’s aesthetic palette: the colour blue.

Cautery excision of oral mucocele in pediatric children: A case report

Introduction: Oral mucocele is a common, oral lesions that mostly present as painless, clear, or bluish cysts on the lower lip of children and young adults. These are harmless, mucus-filled growths usually resulting from a little salivary gland or duct injury. Mucus can leak into surrounding subepithelial tissue when the salivary glands are injured by lip biting, sucking, or trauma. This is known as a mucus extravasation cyst, and it is the most frequent variety of mucoceles. This report presents two cases of mucocele. Case History: Two case studies of oral mucoceles reported that almost all included lip mucoceles were clinically bullous lesions, it was soft, fluctuant, and palpable, which corroborates the hypothesis that lip mucoceles are commonly incited by traumatic injury such as tooth impingement and lip-biting habit. All cases were treated with a simple excision using an electrocautery. Two lesion diagnosis was confirmed by Histopathology anatomy (HPA). Discussion: Mucoceles are common oral lesions often seen in children and adolescents, typically caused by lip biting due to psychological stress. Diagnosis is based on clinical features such as rapid appearance, size variations, and bluish color. Treatments include scalpel excision and electrocautery, with electrocautery providing minimal bleeding and painless wounds. Conclusion: One of the typical salivary gland lesions in the oral cavity is mucocele. The use of electrocautery is known to be beneficial for wound healing. Awareness education for children and parents is necessary to eliminate a lip-biting habit.

Anthocyanins as Natural Food Colorings: The Chemistry Behind and Challenges Still Ahead.

Anthocyanins are polyphenolic O-glycosides widely responsible for the bright red, purple, and blue colors in the plant kingdom, including a great variety of fruits and vegetables. Hence, they have attracted considerable scientific and industrial interest as potential natural food colorings. However, individual anthocyanins are intrinsically reactive molecules combining electrophilic, nucleophilic, and electron-donating properties. This reactivity may be not only a source of color diversity with, for instance, the formation of new pigments upon winemaking and storage but also a cause of great color instability involving a combination of reversible and irreversible mechanisms (e.g., water addition, autoxidation) leading to colorless products. Hence, using anthocyanin-rich plant extracts as food colorings requires a deep understanding of these color-damaging mechanisms and, no less importantly, of the color-stabilizing mechanisms developed by plants, including π-stacking interactions (self-association, copigmentation), metal binding, and a combination of both. The potential of anthocyanins from deeply colored vegetables, typically acylated by hydroxycinnamic acid residues, will be emphasized in that respect. Moreover, food-grade biopolymers (proteins, polysaccharides) may provide suitable matrices for ready-to-use formulations of anthocyanins as food colorings. In this short review, the mechanisms of color loss and color stabilization are discussed as a function of anthocyanin structure and environment, and some challenges still ahead are outlined.

Extraction and characterization of anthocyanin pigments from Iris flowers and metal complex formation

Exploring the chemical processes and factors influencing the stability of the blue color derived from anthocyanins is a crucial objective in agricultural and food chemistry research. The ability of these compounds to bind with metals could potentially stabilize anthocyanins extracted from plant-based foods or enable modifying their hues for application as natural food colorants. This study had two core objectives - first, to extract and identify the major anthocyanin pigments responsible for iris flower coloration. Second, to selectively complex purified iris anthocyanins with aluminum (Al3+) and copper (Cu2+) ions, probing the coordination chemistry underlying synthetic metalloanthocyanin formation. Fresh iris flowers were collected and anthocyanins extracted using an optimized acidic solution. After separation, anthocyanins were complexed with metals Al3+ and Cu2+ at pH 5–6 to understand better the evolution of blue and green colors in anthocyanin-metal chelates. Characterization of anthocyanins and their metal complexes utilized UV–visible spectrometry, colorimetry (L\\* a\\*b\\* values), FTIR spectroscopy, and LC-MS. Metal complexation of anthocyanins exhibited bathochromic shifts of visible absorption maxima from 538 to 584 nm for Al-complex and 538–700 nm for Cu-complex. Color changes were accompanied by decreased lightness (L\\*, from 87 to 81) and color coefficients a\\* (+5.4 to −6.8) and b\\* (−12.2 to −4.8). LC-MS analysis identified five major anthocyanin aglycones: cyanidin (Cyd, m/z 289), delphinidin (Dpd, m/z 305), petunidin (Ptd, m/z 229), malvidin (Mv, m/z 329) and pelargonidin (m/z 273), along with various glycosylated derivatives. This work successfully isolated key iris anthocyanin pigments and elucidated their metal chelation interactions underlying expanded floral color production, bridging knowledge gaps about this underexplored genus.

New H I observations toward the NGC 5055 Galaxy Group with FAST

Abstract We report a new high-sensitivity H\,{\sc i} mapping observation of the NGC~5055 galaxy group over an area of $1.5^\circ\times0.75^\circ$ with the Five-hundred-meter Aperture Spherical radio Telescope (FAST). Our observation reveals that the warped H\,{\sc i} disk of NGC~5055 is more extended than what previously observed by WSRT, out to $ 23.9$ arcmin (61.7 kpc). 
The total \HI\ mass of NGC~5055 is determined to be $\rm\sim 1.1\times10^{10}\,M_\odot$.
We identified three H\,{\sc i} clouds with H\,{\sc i} masses of the order of $\rm \sim 10^7\,M_\odot$ at the southeastern edge of the H\,{\sc i} disk, as well as a candidate high-velocity cloud with an H\,{\sc i} mass of \textcolor{blue}{$\rm (1.2\pm0.5) \times10^6\,M_\odot$} to the north of NGC~5055.
The HI content of UGCA 337 is robustly detected for the first time by the FAST observations. It has a narrow HI linewidth of \textcolor{blue}{$W_{50}=17.4\pm3.8$ km s$^{-1}$} with a total \HI\ mass of \textcolor{blue}{($\rm 3.5\pm0.3)\times10^6\,M_\odot$}. Comparing the gas content and g-r color of UGCA~337 with typical low-mass dwarf galaxies, UGCA~337 appears relatively gas-poor despite its blue colour. This suggests that UGCA~337 may have undergone gas stripping in the past. 
We also analyzed the possible origin of the diffuse \HI\ clouds located at the outskirts of NGC~5055, and speculate that they might be the remnant features of a merger event in the past.

Colorimetric Detection of Fentanyl Powder on Surfaces Using a Supramolecular Displacement Assay.

Fentanyl is a potent synthetic opioid with an alarmingly low lethal dosage of 2 mg. The equipment necessary to detect fentanyl in field settings (e.g., hand-held spectrometers) is restricted to highly trained, well-funded, and specialized personnel. Established point-of-need technologies, such as lateral flow immunochromatographic strips, are available; however, they often involve multiple contact-based steps (e.g., collection, mixing) that pose a higher risk to users handling unknown substances. Herein, we developed a colorimetric displacement assay capable of contactless detection of fentanyl in liquid or solid samples. The basis of our assay relies on the presence of fentanyl to displace a redox mediator, ferrocene carboxylic acid, inclusively bound in the cavity of a supramolecular host, CB[7]. The displacement is only possible in the presence of high affinity binding guests, like fentanyl (KA ∼ 106 M-1). The liberated redox guest can then react with indicator reagents that are free in solution, producing either: (i) a distinct blue color to indicate the presence of fentanyl or (ii) a pale blue tint in the absence of fentanyl. We demonstrate rapid and specific detection of fentanyl free base and fentanyl derivatives (e.g., acetyl fentanyl and furanyl fentanyl) against a panel of 9 other common drugs of abuse (e.g., morphine, cocaine, and heroin). Furthermore, we highlight the intended use of this assay by testing grains of fentanyl derivatives on a surface with a drop (i.e., 25 μL) of the assay reagent. We anticipate that this approach can be applied broadly to identify the presence of fentanyl at the point of need.

Application of anthocyanins from blue pea flower in yoghurt and fermented milk: An alternate natural blue colour to spirulina

Studies investigating the application of blue pea flower anthocyanins in fermented dairy products are limited. In this study, the application of anthocyanin extracts from blue pea flower (Clitoria ternatea) in yoghurt and fermented milk at 1 and 2% (w/v) concentrations was investigated and compared to a commercial blue colourant from spirulina. The total anthocyanin content (TAC), antioxidant activity (DPPH free radical and ferric reducing antioxidant power assays), pH, titratable acidity, syneresis, colour, and viable cell count were measured at 6 days intervals for 30 days at 4 °C storage. The TAC of yoghurt with blue pea flower anthocyanin extract demonstrated high stability, but the TAC of fermented milk with blue pea flower anthocyanin extract decreased significantly. The yoghurt and fermented milk with blue pea flower anthocyanin extract demonstrated higher antioxidant activity than the negative control and samples containing spirulina. The total colour change (ΔE) of yoghurt with blue pea flower anthocyanin extract was less than that of yoghurt containing spirulina during storage. However, the colour of fermented milk with blue pea flower anthocyanin extract was less stable than samples containing spirulina. The average colour acceptability of yoghurt and fermented milk containing 2% (w/v) blue pea flower anthocyanin extracts and those containing spirulina colourant was not significantly different. Therefore, an anthocyanin extract from blue pea flowers at 2% (w/v) concentration was a better blue colourant than spirulina in yoghurt. Spirulina was a better colourant compared to blue pea flower anthocyanins for fermented milk.

Characterization of Polyphenol Composition and Starch and Protein Structure in Brown Rice Flour, Black Rice Flour and Their Mixtures

The study investigates the structural and chemical properties of brown rice flour (WRF), black rice flour (BRF) and their mixtures in ratios of 25%, 50% and 75% to provide reference information for the gluten-free bakery industry. BRF contains higher concentrations of proteins, lipids, total minerals, crude fiber, total polyphenols, proanthocyanidins and flavonoids than WRF. A higher amylose content in BRF than in WRF resulted in flour mixtures with slower starch digestion and a lower glycemic response depending on the BRF ratio added. Differences in the chemical composition of WRF and BRF led to improved composition of the flour mixtures depending on the BRF ratio. The presence of anthocyanidins and phenolic acids in higher concentrations in the BRF resulted in a red–blue color shift within the flour mixtures. The deconvoluted FTIR spectra showed a higher proportion of α-helixes in the amide I band of BRF proteins, indicating their tighter folding. An analysis of the FTIR spectra revealed a more compact starch structure in BRF than in WRF. By processing reflection spectra, nine optically active compound groups were distinguished in rice flour, the proportion in BRF being 83.02% higher than in WRF. Due to co-pigmentation, the bathochromic shift to higher wavelengths was expressed by the proanthocyanins and phenolic acids associated with the wavelengths 380 nm to 590 nm and at 695 nm. Anthocyanins, protein–tannin complexes, methylated anthocyanins and acylated anthocyanins, associated with wavelengths 619, 644 and 668 nm, exhibited a hypsochromic effect by shifting the wavelengths to lower values. This research represents a first step in the development of rice-based products with increased nutritional value and a lower glycemic index.

The Role of WO3 Nanoparticles on the Properties of Gelatin Films

Gelatin films are very versatile materials whose properties can be tuned through functionalization with different systems. This work investigates the influence of WO3 nanoparticles on the swelling, barrier, mechanical, and photochromic properties of gelatin films. To this purpose, polyvinylpirrolidone (PVP)-stabilized WO3 nanoparticles were loaded on gelatin films at two different pH values, namely, 4 and 7. The values of swelling and solubility of functionalized films displayed a reduction of around 50% in comparison to those of pristine, unloaded films. In agreement, WO3 nanoparticles provoked a significant decrease in water vapor permeability, whereas the decrease in the values of elastic modulus (from about 2.0 to 0.7 MPa) and stress at break (from about 2.5 to 1.4 MPa) can be ascribed to the discontinuity created by the nanoparticles inside the films. The results of differential scanning calorimetry and X-ray diffraction analysis suggest that interaction of PVP with gelatin reduce gelatin renaturation. No significant differences were found between the samples prepared at pH 4 and 7, whereas crosslinking with glutaraldehyde greatly influenced the properties of gelatin films. Moreover, the incorporation of WO3 nanoparticles in gelatin films, especially in the absence of glutaraldehyde, conferred excellent photochromic properties, inducing the appearance of an intense blue color after a few seconds of light irradiation and providing good resistance to several irradiation cycles.

Origin of bluish pectolite aka larimar from the Dominican Republic: Constraints from mineralogy and geochemistry

The commonly known larimar is usually a gem-quality, bluish pectolite (NaCa2Si3O8OH), intergrown with other associated minerals such as natrolite, prehnite, calcite, chlorite, found only in the Dominican Republic. Less frequently it shows consecutive and/or sequential green, blue, and white coloration within single amygdales/veins developed in altered (chloritized, serpentinized) Cretaceous basalts of the Dumisseau Formation. The origin of larimar is linked to the circulation of low-temperature (<170 °C) alkali-rich deuteric fluids that were later mixed with meteoric waters. Variations of CL colors, ranging from weak brown in green pectolite to strong yellow (Mn2+-activated) in blue and white species, were ascribed to the transition from oxic to suboxic crystallization environment within the single larimar bodies. These changes could be induced by the burial of magmatic rocks and resulted in the emergence of early zeolite (natrolite), and subsequent formation of native copper in a sulphur-deficient hydrothermal environment. Pectolite-forming elements (e.g. Ca and Na), followed by such transition metals as Cu, Cr, Co, and Ni, were released via the alterations of magmatic minerals (diopside, aegirine-augite, and chromite-magnetite) and/or leached from basaltic groundmass. Decoupling between δ18O values of blue (up to 10.67‰), green (up to 9.66‰), and white pectolite (up to 15‰) was maintained by a progressive temperature drop during ongoing pectolitization and/or presence of the boiling-related environment. Meanwhile, anomalously low δD values (from −390.51‰ to −294.02‰) indicate that the crystal structure of pectolite tends to incorporate light hydrogen isotope regardless of the original δD values in mineralizing fluids.

Stomach content analysis in ariids: Insights of three catfish species from a marine protected area

Stomach content analysis in fish provides information about the diet, different trophic groups in the ichthyofauna and concerning the transfer and energy obtaining. The aquatic environment become receptacle for emerging pollutant such as plastic, that become available to the biota. The goal of this study was to describe the feeding of the three catfish species A. luniscutis, C. spixii and G. genidens, in a sexual and spatial approach, considering that are important catfish from a Marine Protected Area in Brazil (Cananeia-Iguape Estuarine-Lagoon Complex – CIELC), subjected to differential anthropogenic disturbances. The analyzed species had a diverse diet, with the occurrence of Crustacea fragments of several groups (e.i.: amphipoda, decapods, mysidae, palinura, caridea, penaeidae, stomatopoda and brachyura), Algae, Polychaeta, Ophiuroidea, Mollusca, vegetable matter, and fish fragments (e.i. otoliths, eggs, scale, fins, and fish debris). The food items of Cathorops spixii were composed mainly of Polychaeta, vegetable matter, and Crustacea. On the other hand, the main food items of Aspistor luniscutis were fish fragments, algae, and vegetable matter and in Genidens genidens predominated Crustacea and vegetable matter. Possible plastic fragments were found and had filamentous format with blue, red, and black color variations. The data of this research contribute to the promotion of knowledge about feeding in three species of catfish. Furthermore, it highlights the pollution of an environmental marine protection area.

CHRONICLES OF HEALING: UNVEILING THE SECRETS OF ABRASION AND LACERATION DATING IN FORENSIC PATHOLOGY

Objective: In the field of forensic pathology, understanding the timeline of injury occurrence is of paramount importance. This study, titled "Chronicles of Healing: Unveiling the Secrets of Abrasion and Laceration Dating in Forensic Pathology," conducted a postmortem investigation to assess wound dating by gross and histopathological examination of blunt injuries. Methods: A total of 195 case samples from 119 cases were scrutinized to establish the timing of various gross changes and microscopic alterations that transpire following blunt trauma. The study encompassed abrasions, contusions, and lacerations occurring within a time frame ranging from 0 h to a maximum of 45 d. Results: The findings revealed that the gross changes in abrasions closely correlated with the corresponding microscopic changes, while contusions exhibited a similar correlation, except for a variation in the appearance of bluish color. In lacerations, the correlation was primarily evident during the early stages of injury. Conclusion: Importantly, the study emphasized the substantial impact of comorbid conditions on the healing process, highlighting the need for cautious evaluation in such cases. The study concludes that naked eye examination alone is insufficient for precise injury dating, underscoring the importance of histopathological examination to ensure accurate conclusions regarding injury age.

Assessing Aluminum Stress Resilience in Common Bean Roots: Phenotypic, Histochemical, and PvGST/PvPOD Gene Expression Analysis

Common bean (Phaseolus vulgaris L.) is grown in various parts of the world. Aluminum (Al) toxicity poses a significant and widespread challenge in marginal areas with unfavorable soil qualities where common bean is grown. In acidic soils, stable forms of Al dissolve into the soil solution and inhibit root growth and function by injuring the root apex with phytotoxic ions. This leads to the development of a smaller root system, adversely affecting crop yield. In this study, the phenotypic evaluation for relative root elongation of 10 common bean genotypes/cultivars under Al stress (50 µM), the impact of Al toxicity using different histochemical dyes (Evan’s blue and Schiff’s reagent) and the expression levels of PvGST (Glutathione S-transferases) and PvPOD (peroxidase) genes in the root tissues of the most resistant/sensitive common beans under Al stress (50 µM) and control conditions (0 µM) were investigated. The maximum relative root elongation value (71.9%) was found in Önceler-98 cultivar, while the lowest value (14.1%) was obtained from Blksr-19 genotype. Histochemical applications used in the study supported phenotypic results. The cracks at the root tip and high blue color intensity were detected in Schiff’s reagent and Evan’s blue dyes in the Blksr-19, respectively. The expression levels of PvGST and PvPOD genes in the root tissue of the Blksr-19 (Al-sensitive) were highly upregulated at 24 h of Al stress treatment. The results revealed that these genes might be involved in the common bean root tissue's defense mechanism against Al stress for the first time. The findings herein will help plant breeders develop common bean cultivars tolerant to Al toxicity.

EPOCHS Paper – VIII. An insight into MIRI-selected galaxies in SMACS-0723 and the benefits of deep MIRI photometry in revealing AGN and the dusty universe

ABSTRACT We present the analysis of the stellar population and star formation history of 181 MIRI selected galaxies at z = 0 − 3.5 in the massive galaxy cluster field SMACS J0723.3–7327, commonly referred to as SMACS0723, using the JWST Mid-Infrared Instrument (MIRI). We combine the data with the JWST Near Infrared Camera (NIRCam) catalogue, in conjunction with the Hubble Space Telescope (HST) WFC3/IR and ACS imaging. We find that the MIRI bands capture PAH features and dust emission, significantly enhancing the accuracy of photometric redshift and measurements of the physical properties of these galaxies. The median photo-z’s of galaxies with MIRI data are found to have a small 0.1 per cent difference from spectroscopic redshifts and reducing the error by 20 per cent. With MIRI data included in SED fits, we find that the measured stellar masses are unchanged, while the star formation rate is slightly lower by 0.1 dex. We also fit the median SED of active galactic nuclei (AGNs) and star-forming galaxies (SFG) separately. MIRI data provides tighter constraints on the AGN contribution, reducing the typical AGN contributions by ∼15 per cent. In addition, we also compare the median SED obtained with and without MIRI, and we find that including MIRI data yields steeper optical and UV slopes, indicating bluer colours, lower dust attenuation, and younger stellar populations. In the future, MIRI/MRS will enhance our understanding by providing more detailed spectral information and allowing for the study of specific emission features and diagnostics associated with AGN.

Hexagonal Boron Nitride Quantum Dots Embedded on Layer-by-Layer Films for Peroxidase-Assisted Colorimetric Detection of β-Galactosidase Producing Pathogens.

Pathogen detection has become a major research area all over the world for water quality surveillance and microbial risk assessment. Therefore, designing simple and sensitive detection kits plays a key role in envisaging and evaluating the risk of disease outbreaks and providing quality healthcare settings. Herein, we have designed a facile and low-cost colorimetric sensing strategy for the selective and sensitive determination of β-galactosidase producing pathogens. The hexagonal boron nitride quantum dots (h-BN QDs) were established as a nanozyme that showed prominent peroxidase-like activity, which catalyzes 3,3',5,5'-tetramethylbenzidine (TMB) oxidation by H2O2. The h-BN QDs were embedded on a layer-by-layer assembled agarose biopolymer. The β-galactosidase enzyme partially degrades β-1,4 glycosidic bonds of agarose polymer, resulting in accessibility of h-BN QDs on the solid surface. This assay can be conveniently conducted and analyzed by monitoring the blue color formation due to TMB oxidation within 30 min. The nanocomposite was stable for more than 90 days and was showing TMB oxidation after incubating it with Escherichia coli (E. coli). The limit of detection was calculated to be 1.8 × 106 and 1.5 × 106 CFU/mL for E. coli and Klebsiella pneumonia (K. pneumonia), respectively. Furthermore, this novel sensing approach is an attractive platform that was successfully applied to detect E. coli in spiked water samples and other food products with good accuracy, indicating its practical applicability for the detection of pathogens in real samples.

Versatile preparation of jellyfish-inspired color transition hydrogels via polymerization induced supramolecular geletion (PISG)

Supramolecular hydrogels based on host–guest interactions constitute a class of intriguing soft matter and have attracted great attention due to their unique properties, etc. In this study, we successfully synthesized 4-methylene-7-diethylaminocoumarin methacrylate (DEACMMA) monomer and carried out reversible addition-fragmentation chain transfer (RAFT) polymerization using methylated β-cyclodextrin via a host-guest encapsulation mechanism. This process led to the formation of ternary copolymer hydrogel supramolecular photoresponsive hydrogels through polymerization induced supramolecular gelation (PISG). The encapsulation of coumarin monomers by methylated cyclodextrins was confirmed using 2D ROESY NMR and fluorescence spectroscopy. We have carefully analyzed the microstructure of these supramolecular hydrogels by rheological profiles and scanning electron microscopy (SEM). Stimulated by UV light, the copolymers transition from non-luminescence to a bright fluorescent blue color, which is reminiscent of the self-transforming colors observed in jellyfish. The development of photostimuli-responsive hydrogels based on methylated β-cyclodextrin-coated coumarin esters opens new avenues in the fields of smart materials and clinical medicine.

An Unknown 18th-Century Flemish Dyers Manuscript from Antwerp (1778–1802)

This paper presents a historical analysis of a rare dyer’s manuscript, preserved within the Museum of Industry in Ghent, Belgium. The manuscript, originating from a dyer in late 18th-century Antwerp, includes an extensive collection of recipes. The study will enable researchers to better grasp the practices of traditional dyeing techniques and materials in the region during that time. The manuscript focuses primarily on the dyeing of woolen fabrics. Approximately 90 of the 132 recipes utilize red dyes. Recipes for dying orange, brown, black, blue, and green colors are also described. The document mentions the use of madder, brazilwood, redwood, and cochineal. To create a variety of red shades, the dyer describes how fabrics were treated with different mordanting compounds, with alum and tin as the main ingredients, and how the dyeing solutions were prepared. The resulting colors include ‘madder red’, ‘formal red’, ‘crimson’, ‘scarlet’, ‘Turkish red’, ‘fire color’ and ‘flesh color’. In addition to the dyeing recipes, the manuscript contains various accounting documents and correspondences between the dyer, customers, and suppliers. Lastly, over 100 original, colored samples are attached to the described recipes. In this paper, the artifact’s contents will be disclosed, comprising recipes with attached samples and correspondence. Findings resulting from archive research will be included, contextualizing and placing the dyer in their urban and social context. The paper concludes by discussing its potential limitations and provides avenues for possible future research.

Visible emission studies by UV light conversion in (Dy3+/Tb3+) ions pair activated zinc-bismuth-barium borotellurite glasses for achieving intense green and white light

Both white light and green emission properties of (Dy3+/Tb3+) ions pair activated zinc-bismuth-barium borotellurite glasses were studied by ultraviolet light (UV:388 and 366 nm) conversion with a focus on down-conversion process. On the dependences of Tb3+ amounts with co-doping of Dy3+, densities of glasses, excitation, emission, area of the integration in percent, decay times, multipolar interactions, and most responsible photometric parameters are investigated in the current work. These co-activated glasses show a broad color production range (450–700 nm) covering of red (∼622 nm), green (∼545 nm), and blue (∼488 nm) colors under the stimulation of UV light wavelengths. The ratio from Yellow to blue emission was analyzed to study the site symmetry of Dy3+ surrounds. With 388 nm of UV radiation, the area of the integrated intensity under the green (Tb3+:545 nm) peak reaches a maximum of 87 %, while it falls under the yellow (Dy3+:575 nm) peak at about 13 %. The decay times of co-activated glasses were found in decreasing order, followed by fitting with a double-exponential function. The Reisfeld and Dexter's energy transfer mechanism confirmed the reduction in Dy3+ emission and its lifetime values through quadrupole-quadrupole interaction (f = 10). Moreover, photometric properties such as relative color temperatures, color coordinates, and color purity were also discussed and compared to discriminate the potentiality of the present fabricated glasses for use in both white light and green-emitting devices.

Physicochemical characterization of a composite flour: Blending purple sweet potato and rice flours

In this study, the physicochemical characterization of different ratios of purple sweet potato flour (PSPF) and rice flour was investigated to improve the nutritional value and enrich the variety of rice-based staple food. The results showed that adding PSPF increased total dietary fiber and anthocyanin content whereas decreased amylose content of the composite flours. Additionally, the composite flours exhibited lower thermodynamic parameters and displayed darker, redder, and bluer colors. There were no noticeable changes in the functional group structure of the composite flours. The addition of PSPF decreased the crystallinity and water-holding capacity of the composite flours, whereas increased the average particle size and iodine blue value. PSPF increased the pasting temperature of the flours whereas decreased the breakdown and setback values. Overall, the addition of PSPF significantly affects the nutrition, color and physicochemical properties of the composite flours.

Using urea-shifting to create a natural blue, antioxidant emulsifier from phycocyanin

Phycocyanin (PC) is an algae-derived blue protein that can serve as an antioxidant emulsifier and colorant. Urea was used as an emulsification aid by balancing PC’s hydrophilic-lipophilic character and was removed by dialysis after emulsification processes. With increasing concentration, urea gradually dissociated and denatured the PC polymers. By using spectroscopic methods, the aromatic amino acids and chromophores appeared to fold inward, and the secondary helix structure devolved into the unordered structure. Structural changes caused the hydrophilic PC to become more hydrophobic, resulting in an increase of its emulsifying capacity with a concomitant cost to PC’s natural blue color. The partially denatured PC increased the amount of PC surface adsorption at the O/W interface by 39.89% of adsorbing percentage and the O/W interfacial protein concentration was 1.56 mg m-2, resulting in finer and more dispersed emulsion droplets. Therefore, although the denaturation resulted in a partial weakening of the protein’s antioxidant properties (from 7.70 to 5.54 nmol L-1 Trolox equivalent), the stabilized droplets allowed the emulsions to exhibit higher apparent antioxidant properties (from 7.80 to 7.87 nmol L-1 Trolox equivalent). In the 37 °C storage stability evaluation, emulsions with lower starting urea concentrations remained blue longer, while those with higher starting urea concentrations remained more stable to long-term storage and showed lower oxidation levels. The urea concentration of 5 M was chosen because it maintained a relatively stronger blue color while keeping the emulsion more stable and protecting the oils from further oxidation.