Dark Blue Research Articles

Transformative personalized oxalate biomarker analysis through a wrist-worn microneedle device integrated with duplex nanozyme toolbox

The interstitial fluid (ISF) is valuable for disease diagnosis due to its unique biomarkers. Microneedles (MNs) offer a painless method for ISF sampling, facilitating primary diagnostics. This study introduces a minimally invasive, biocompatible MN patch made from a swellable hydrogel of polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP), which effectively extracts ISF. The hydrogel selectively permits small molecules like oxalate, a kidney disease biomarker, while blocking large biomolecules. The MN patch is integrated with a multilayer sensor via microfluidic channels, featuring cotton fiber, agarose, and Mn3[Fe(CN)6]2, alongside Fe3[Fe(CN)6]3 (AGH-CP/MnFeCN/FeFeCN). These nanozymes exhibit oxidase-like activity, reacting with 3,3′,5,5′-tetramethylbenzidine (TMB) to indicate oxalate levels through a color change from green (no oxalate) to light or dark blue, based on concentration. The designed sensor demonstrates high performance with a detection limit of 0.897 μM and an RSD of 1.22 %, enabling accurate quantification via smartphone image analysis as readout platforms for more accessibility and user-friendliness which helps to reach personalized healthcare goals. This integration facilitates real-time, remote, precise disease detection, biochemical analysis and forsooth miniaturization, leading to the development of portable, flexible, and wearable sensors. The MN patch and integrated sensor show excellent stability, selectivity, sensitivity, reliability, and long-term durability. This minimally invasive sensing system, designed for wristband integration, opens new avenues for precision point-of-care monitoring, enhancing personal healthcare.

Rapid detection of guttae area using aniline blue staining in Fuchs endothelial corneal dystrophy mouse model.

Fuchs endothelial corneal dystrophy (FECD) is a leading cause of corneal endothelial degeneration resulting in impaired visual acuity. Excessive deposition of extracellular matrix (guttae) on Descemet's membrane (DM) is the hallmark of FECD. We sought to detect the guttae area rapidly using aniline blue (AB) staining in FECD mouse model. FECD mouse model was established via ultraviolet A (UVA) exposure. Masson's trichrome staining was utilized to stain the corneal sections. AB staining was utilized to stain both whole cornea tissues and stripped Descemet's membrane-endothelium complex (DMEC) flat mounts, while immunofluorescence staining of collagen I was employed to stain guttae areas. In Masson's trichrome staining, corneal collagen fibrils were stained blue with AB. The DMEC flat mounts were stained into relative dark blue areas and relative light blue areas using 2% AB staining. The areas of dark blue could almost overlap with collagen I-positive areas, and have an acellular centre and a moderately distinct boundary line with the surrounding corneal endothelial cells. In conclusion, AB staining is a rapid and effective method for the evaluation of the guttae areas in the FECD mouse model.

Intelligent locust bean gum-k-carrageenan nanofibrous mats with Rosa canina petal anthocyanins and chitosan nanoparticles: Preparation, characterization, and application for monitoring of beef meat freshness

The objectives of the present experiment were to add Rosa canina petal extract (RCE, 3.5%) and chitosan nanoparticles (CNP, 1.5%) into the locust bean gum-kappa-carrageenan (LBG-KC) nanofiber mats and to examine their utilization for the freshness tracking of beef meat during the 6-day storage period. The surface morphology analysis of nanofibers using the scanning electron microscope showed that all developed nanofibers were cylindrical, uniformly disordered network structures with smooth surfaces. The tensile strength, elongation at break, water vapor permeability, water solubility, and moisture content of RCE/CNP-loaded nanofiber mats were recorded to be 10.00–31.77 MPa, 16.55%–22.98%, 5.04–9.18 × 10‾5 g mm/m2 h Pa, 3.80%–10.08%, and 2.10%–4.89%, respectively. The LBG-KC + RCE 3.5% and LBG-KC + RCE 3.5% + CNP 1.5% nanofibers were red, dark blue, green, and brown at pH values 1–6, 7–8, 9, and 10–12, respectively. After 4 days of beef meat storage at refrigerated conditions, the total viable count, pH, and total volatile basic nitrogen were 7.24 log CFU/g, 7.11, and 28.89 mg N/100 g, respectively. Moreover, on the 0th day, the pH-sensitive indicators presented a white color and after 4 days of meat storage, the indicator color changed to dark blue, which could indicate beef meat spoilage.

High-contrast electrochromic coatings and devices for health assurance, visual comfort and energy-saving in buildings

High-contrast electrochromic coatings and devices reduce the ultraviolet-radiation from sunlight, ensure human health and visual comfort, save the electricity consumption of the heater in winter, and save electricity consumption of air conditioners in summer. Anodically coloring polymer coatings (P(CDBP), P(CDBP-co-BTPH), P(CDBP-co-TFU), P(CDBP-co-CDT) and P(CDBP-co-CDTK)) based on 4,4′-bis(carbazol-9-yl)-2,2′-dimethylbiphenyl (CDBP) and four different dithiophene derivatives (2,2′-bithiophene (BTPH), 2-(2-thienyl)furan (TFU), 4H-cyclopenta[2,1-b:3,4-b’]dithiophene (CDT), and cyclopentadithiophene ketone (CDTK)) are polymerized electrochemically on ITO electrode. The P(CDBP-co-BTPH) electrochromic coating has high transmittance change (ΔT = 71.1 %) and coloration efficiency (160.6 cm2 C−1). P(CDBP-co-BTPH) film reveals yellow-gray and dark blue in neutral and oxidation states, respectively. Electrochromic energy saving devices (ECDs) are assembled using P(CDBP), P(CDBP-co-BTPH), P(CDBP-co-TFU), P(CDBP-co-CDT) and P(CDBP-co-CDTK) films as the anodic layers and poly(3,4-(2,2-dimethylpropylenedioxy)thiophene) (PPD-M2) film as the cathodic layer. P(CDBP-co-BTPH)/PPD-M2 ECD shows a high transmittance change (ΔT = 30.3 %) and a rapid response time (≤0.3 s). Moreover, P(CDBP-co-BTPH)/PPD-M2 ECD also has sufficient optical memory and redox cycling stability. These findings provide us new insights for the useful design of polymer coatings in rapid switching electrochromic energy-saving devices and switchable architectural windows.

A facile route to fabricate transparent and mechanically robust glass-fabric reinforced composites via refractive index matching and tow-spreading technique

There are challenges to fabricate GFRPs with high optical clarity and mechanical performance due to the inevitable chromatic dispersion and yarn crimp in the fabric. Herein, a facile route to fabricate transparent glass-fabric reinforced composites is reported using refractive index matching and tow-spreading technique. By introducing different amount of BMA, the epoxy matrix could match the refractive index of glass fibers at different wavelength. The fabricated composites exhibit intriguing pale blue/blue, dark blue/ purple, purple-pink/pink chromatic dispersion, respectively. Among them, the 0.2 mm-thick GFRP with 4 % BMA (fiber volume fraction ≈ 50.4 %) exhibits the highest total transmittance (89.5 %) and lowest haze (3.4 %). Compared with commercial standard-tow fabric, composites with spread-tow fabrics exhibits less chromatic dispersion and transparency loss. Moreover, simultaneously reinforcing and toughening effect could be observed in the composites with BMA modified matrix. The optimized composites possess tensile strength of 289 MPa and flexural strength of 416 MPa.

Formation and Cycling of Microscale Silicon Anodes at Elevated Temperatures with FEC-Based and EC-Based Electrolytes

Silicon is a promising candidate to replace graphite (372 mAh g-1) as anode material in lithium-ion batteries (LIBs) due to its high theoretical gravimetric capacity of 3589 mAh g-1.1 Graphite is already partially substituted by silicon in commercial battery applications in order to increase the energy density of LIBs.2 However, a complete transition to silicon is still hindered by the extreme volume expansion of up to 300% upon complete electrochemical lithiation to Li15Si4.3 This causes particle cracking, electrical contact loss of active material, and the continuous (re-)formation of the solid electrolyte interphase (SEI) on the newly formed surface, leading to a continuous loss of cyclable lithium and a fast capacity fading of the cell.One approach to mitigate Si particle cracking is the partial lithiation of microscale silicon, limiting the capacity to ~1200 mAh g-1, i.e., one-third of the theoretical capacity, enabling a cycle-life of more than 200 cycles before reaching 80% state-of-health (SOH).4 While electronic disconnection of lithiated silicon contributes to the overall cyclable lithium losses, the continuous formation of the SEI remains one of the major challenges that limit the lifetime.5 Fluoroethylene carbonate (FEC) has been shown to be one of the most suitable additives for silicon-containing cells to ensure the formation of a suitable SEI and comparably stable cycling performance.6,7 However, especially at elevated temperatures, FEC decomposes to form vinylene carbonate and hydrogen fluoride, which is detrimental to the SEI.8 This study investigated temperature-dependent cycle-life stability of microscale-silicon dominant anodes with EC-based and FEC-based electrolytes at room and elevated temperature. The electrodes consist of 70% silicon (Wacker Chemie AG) with an LiPAA binder (8%) and conductive carbon (2%). Additionally, graphite (8% KS6L, Imerys) was added to enhance the electronic conductivity, whereby within the operating voltage range of the anode, only a minor capacity of the graphite is used. As electrolytes, either 1 M LiPF6 in EC:DEC 1:2 v:v (EC-based) or 1 M LiPF6 in FEC:DEC 2:8 v:v (FEC-based) were used. Full-cells were cycled with a nickel-rich transition metal oxide cathode active material (LiNi0.83Co0.12Mn0.05O2 (NCM831205), BASF SE) based cathode at 25 °C and 45 °C. As shown in Figure 1, cycling in coin cells revealed the expected decreased cycle-life of cells with the FEC-based electrolyte at 45 °C (light blue) compared to 25 °C (dark blue).8 However, cycling cells with the FEC-free, EC-based electrolyte (green) at elevated temperatures, showed the opposite trend. The cycle-life until 80% SOH increased by 110 cycles (+100%), surpassing that of the cells with the FEC-based electrolyte at 45 °C. The charge-averaged mean voltages for both charge and discharge were investigated to identify the main failure mechanisms. This allowed us to differentiate between the loss of cyclable lithium and internal cell resistance build-up.To better understand the contributions of anode and cathode to capacity fading, we assembled Swagelok® T-Cells with the same cell chemistry and cycled them analogously. While the resistance of the cathode remained nearly constant over the whole course of cycling, the resistance of the anode showed an increase with decreasing cell capacity. Furthermore, online electrochemical mass spectrometry (OEMS) was performed to determine the gases evolved during formation with the EC-based electrolyte at 25 °C and 45 °C. This allowed us to gain insights into the overall SEI formation mechanism and to differentiate the formation of suitable SEI components.

Utilization of Butterfly Pea Flower as Shelf-Life Colour Indicator for Keropok Lekor Smart Packaging

Studying the feasibility of using Clitoria ternatea or butterfly pea extract (BPE) as a colorimetric indicator to determine the shelf life of Keropok Lekor would aid in monitoring storage conditions, emphasizing its potential contribution to the smart packaging industry. The objective of this research is to develop pH-sensitive packaging using gelatine film infused with butterfly pea extract (BPE) along with ultrasonic-assisted extraction methods. The investigation involves quantifying the physicochemical attributes of the extracted butterfly pea and ascertaining the colour alterations during the storage of Keropok Lekor over a duration of six days. The determination of total anthocyanin content in BPE, conducted through a pH differential assay, yielded a value of 1.08 mg/g. Texture analysis revealed that the film with 10% BPE exhibited elevated tensile strength (0.11±0.01) and toughness (0.03±0.01). Total phenolic compound analysis indicated that the film containing 30% BPE possessed the highest value at 0.16±0.02. Notably, the film with 30% BPE demonstrated the highest colour change in Keropok Lekor storage from dark blue (-22.5±80.95) to dark green (6.34±1.85) over the course of six days. The film incorporated with 30% BPE stands as a viable colour indicator, demonstrating the potential for monitoring the freshness and quality of Keropok Lekor.

Towards a Wearable Feminine Hygiene Platform for Detection of Invasive Fungal Pathogens via Gold Nanoparticle Aggregation.

Candida albicans is an opportunistic fungus that becomes pathogenic and problematic under certain biological conditions. C. albicans may cause painful and uncomfortable symptoms, as well as deaths in immunocompromised patients. Therefore, early detection of C. albicans is essential. However, conventional detection methods are costly, slow, and inaccessible to women in remote or developing areas. To address these concerns, we have developed a wearable and discrete naked-eye detectable colorimetric platform for C. albicans detection. With some modification, this platform is designed to be directly adhered to existing feminine hygiene pads. Our platform is rapid, inexpensive, user-friendly, and disposable and only requires three steps: (i) the addition of vaginal fluid onto sample pads; (ii) the addition of gold nanoparticle gel and running buffer, and (iii) naked eye detection. Our platform is underpinned by selective thiolated aptamer-based recognition of 1,3-β-D glucan molecules-a hallmark of C. albicans cell walls. In the absence of C. albicans, wearable sample pads turn bright pink. In the presence of C. albicans, the wearable pads turn dark blue due to significant nanoparticle target-induced aggregation. We demonstrate naked-eye colorimetric detection of 4.4 × 106C. albicans cells per ml and nanoparticle stability over a pH range of 3.0-8.0. We believe that this proof-of-concept platform has the potential to have a significant impact on women's health globally.

Radical cations of chalcogenanthrenes with halogenido metalate anions. Part I: tetramethoxythianthrene

Abstract The electron-rich molecule tetramethoxythianthrene TMO-TA can readily be oxidized to the radical cation using various transition metal halides in acetonitrile as solvent. Reactions with CuBr2, FeCl3, AuCl3, NbCl5, and CuCl2 yield dark blue or black crystals of [TMO-TA]2[CuBr4] (2), [TMO-TA][FeCl4] · CH3CN (3), [TMO-TA][AuCl4] (4), [TMO-TA][NbCl6] · CH3CN (6), and [TMO-TA]5[Cu2Cl6]2 · 2 CH3CN (7). [TMO-TA]2[Ta2OF10] (5) was obtained by anodic oxidation of TMO-TA in the presence of (Nbu4)2[Ta2OF10] as electrolyte. Using mercury(II) bromide, no redox reaction occurs. Instead, the colorless complex [HgBr2(TMO-TA)] (1) is formed. In the crystal structures of the compounds 2–7, the almost planar radical cations show different types of arrangements. Pair formation of the [TMO-TA]•+ radicals to [TMO-TA]2 2+ dimers with the typical intra-pair S⋯S bonds of 3.1–3.2 Å lengths is predominant. Compounds 6 and 7 contain stacks of planar TMO-TA molecules in equidistant arrangement without pair formation and the unique feature of rotation of each adjacent cation by about 30°. Compounds 2, 5, and 7 are electrical semiconductors with band gaps between 0.62 and 1.4 eV, reflecting the arrangement of the radical cations. While 5 is diamagnetic, the magnetic momenta of 2 and 7 correspond only to the expected paramagnetic momenta of magnetically dilute Cu2+ ions. Electrons on the organic radicals are strongly paired in all compounds.

VACCINIUM OVALIFOLIUM SMITH. IN NATURAL CENOPOPULATIONS OF SAKHALIN

Background. Identification and study of selected forms of oval-leaved blueberry in natural coenopopulations of Sakhalin Island will create a favorable basis for modern breeding work. Purpose. The goal was to isolate and study selected forms of Vaccinium ovalifolium Smith. in natural coenopopulations of Sakhalin Island. Material and methods. The object of research was natural populations of Vaccinium ovalifolium growing on Sakhalin Island. The study of blueberries in natural habitats was carried out during expeditionary trips to the central and southern regions of Sakhalin in the period 2020-2022. Plants from 2 cenopopulations were studied for the distribution of blueberries in hard-to-reach places. Geobotanical descriptions of the vegetation of phytocenoses were carried out according to the generally accepted method of A.A. Poniatovskaya “Taking into account the abundance and nature of the distribution of plants in communities” (1964). The species composition of plant communities was determined within the detection area. The total projective cover (TPC) of the grass stand and the projective cover of the dominant species were determined by eye method, in %. We studied the endogenous variability of the following traits: the number of berries, the weight and size of one berry, the length and width of the leaf blade, the height and age of the bushes. A correlation analysis was carried out between morphological characteristics and yield characteristics in the trial plots. Height, age, maximum and minimum crown diameter, degree of fruiting, and number of berries were analyzed. Mathematical and statistical processing of research results was carried out according to generally accepted methods using Excel software. Results. The article is devoted to a new promising shrub for Russia, Vaccinium ovalifolium - a species of deciduous shrub from the genus Vaccinium of the Ericaceae family, a shrub up to 1.5-2 m tall. It blooms in May–June, the flowers are pink, up to 6 mm in size, the fruits are dark blue, often black with a waxy coating, ripen in August–September, the juice in the berries is clear, the taste is sweet and sour. The leaves are oblong - round or ovate, entire-marginal or with small ciliated teeth 2-5 cm long and 1-2.5 cm wide, matte, light green. Polymorphism of natural cenopopulations of V. ovalifolium during expeditionary surveys made it possible to identify several promising forms with economically valuable traits. In the process of phylogenesis of V. ovalifolium, ecologically resistant populations to the unfavorable environmental factors of Sakhalin Island were formed. Selected samples of V. ovalifolium with valuable pomological traits are currently propagated and grown on the territory of the Botanical Garden of the city of Yuzhno-Sakhalinsk at the site of primary variety testing, to compare the resource value of local natural eco-genetic lines with the introduced, most common modern varieties of V. corymbosum. Experience has been laid in assessing selected forms of oval-leaved blueberries for agrotechnical techniques and agricultural conditions, with the subsequent development of technological recommendations for cultivation in an industrial garden in the conditions of Sakhalin Island. Conclusion. The polymorphism of natural cenopopulations of V. ovalifolium on Sakhalin Island was studied with the selection of promising forms that can be used for breeding purposes.

Estimation of Imatinib Mesylate by Extractive Colorimetric Methods in Bulk and Pharmaceutical Dosage Form

Simple sensitive and accurate extractive spectrophotometric methods have developed for the estimation of Imatinib mesylate in pharmaceutical dosage form. The methods are based on the formation of coloured complexes by the drug with reagents like bromophenol blue, solochrome dark blue and bromocresol green in acidic medium. The ion associated complexes were formed and quantitatively extracted under the experimental condition in chloroform. The absorbance values were measured at 420 nm, 495 nm and 430 nm respectively. The proposed methods were validated statistically. Recoveries of methods were carried out by standard addition methods. The linearity was found to be 1-8 μg/ml, 2 -16μg/ml, 1-16 μg/ ml for methods 1, 2 and 3 respectively. The low values of standard deviation and percentage RSD indicate high precision of methods. Hence these methods are useful for routine estimation of Imatinib mesylate in tablets.

Carbon nanotube-grid infrared transparent electrodes for flexible electrochromic devices with visible to mid-infrared dual-band modulation

Flexible mid-infrared electrochromic devices (MIR-ECDs) have attracted wide attention due to the growing demands for thermal camouflage and body comfort. However, the normal conductive films (e.g., indium tin oxide/polyethylene terephthalate (ITO/PET) films) are unsuitable for MIR-ECDs due to low infrared transmittance. Herein, the infrared transparent carbon nanotube (CNT) grid films were prepared by designing the grid structure. The infrared transmittance of CNT grid film could reach 72 %; meanwhile, the visible transmittance could reach 75 %. The CNTs exhibited infrared modulation under different voltages due to the doping/de-doping of ions in electrolytes into the CNT network. The flexible electrochromic devices with visible to mid-infrared dual-band modulation were prepared by using CNT grid film as the electrode and poly (3,4 ethylenedioxythiophene):poly (styrene sulfonate) (PEDOT:PSS) as the electrochromic layer, which could realize the infrared synergistic modulation of PEDOT:PSS and CNT grid in the mid-infrared range and reversible color changes between light blue and dark blue in the visible range, showing promising applications in adaptive camouflage and thermal management.

Recording thermal history of pork meat by self-coloration gel

For real-time dynamic quality evaluation of pork meat, the thermal accumulation monitoring for the entire period is essential. The research aims to develop a novel covalent organic framework (COF) gel capable of recording such information. The COF with self-responsive irreversible color change property was synthesized using benzene-1,3,5-tricarboxaldehyde, 2,5-diamino-1,4-benzenedithiol dihydrochloride and p-phthalaldehyde as monomers. The thermal accumulation was monitored based on the COF over a broad temperature range (−22 °C–55 °C), which covered the storage temperatures of the pork meat. The results were easily readable by series visible color variations (yellow, green, blue and dark blue) displayed by COF during the thermal accumulation monitoring in the temperature range (25 °C–55 °C) of study. At the lower temperature (−22 °C–4 °C), small variation of the thermal information can be effectively represented by quantitative analysis. The color change rates were in the order of k-22 °C < k4°C < k25 °C < k35 °C < k55 °C. The activation energy of reaction was 65.31 kJ mol−1. The indicator gel was prepared by the COF combining with carrageenan in pure aqueous medium. The potential application of the COF gel for real-time monitoring the dynamic quality change of pork samples was investigated. The response signals of the COF gel were well matched with the growth rate of microbe in pork meat. The proposed COF gel based thermal history indicator is promising for real-time monitoring dynamic quality changes of pork meat during the cold supply chain.

Co-occurrence of posterior chest wall pilonidal sinus with melanocytic nevus: a challenging presentation: a case report

IntroductionTo date, only a limited number of case reports have documented the co-occurrence of PNS and melanocytic nevus in the medical literature. This study aims to report an exceptionally rare case of posterior chest wall PNS in conjunction with a melanocytic nevus.Case presentationA 46-year-old female presented with a long-standing black lesion on her left upper posterior chest wall, that had become painful in the two months prior to presentation. There was a painful, dark blue, non-erythematous, and non-tender nodule on the left upper posterior chest wall. Based on the patient’s desire for cosmetic purposes, the lesion was excised totally with primary closure under local anaesthesia. Histopathological examination revealed intradermal melanocytic nevus with inflamed pilonidal sinus.DiscussionThe rarity of posterior chest wall PNS associated with nevi poses unique diagnostic and therapeutic challenges for clinicians. The distinct anatomical location, different from the conventional region, and the rare association between the two conditions may delay accurate diagnosis and result in mismanagement or inappropriate interventions.ConclusionThe posterior chest wall PNS is another type of atypical PNS that is extremely rare. The association between PNS and blue nevus is a fascinating medical finding that deserves further investigation.

Softness indicator made from tapioca and ammonium molybdate for avocado

Abstract A softness indicator made from tapioca and ammonium molybdate was used to detect the ripeness of fruit. The indicator in the form of a tablet was attached inside the package of avocado and it was analyzed for its changing color. The results show that there was a suitability between indicator color changes and avocado quality degradation. The tablet indicator showed different colors before and after avocado has been ripped. The color of the indicator from the 1st day until the 2nd day of storage was bright yellow with the °Hue value ranging from 99 – 100. The tablet color then turned into dark blue on the 5th day of storage with °Hue value of of 114 – 178 when the avocado was rotten. The color change was not evenly distributed over the entire surface of the tablet due to being less moisture absorbed by the tablet indicator. In the meantime, fruit quality degradation during the storage was indicated by the increased percentage of weight loss of 20.1% after six days of storage. The firmness decreased and it was confirmed by a texture value of 12.55+1.48 mm/3s on the 1st day of storage became 15.9 + 0.07 mm/3s on the last day of storage. The total soluble solid was recorded to increase from 11°Brix to 14°Brix.

Retrospective Study Regarding the Correlation between Dental Anxiety and Color Preferences in Children with Severe Early Childhood Caries.

Severe early childhood caries (S-ECC) is recognized as a significant chronic disease which affects the quality of life starting at very young ages and has a very rapid evolution towards pulp complication and loss of dental tissue. Children with a high caries index DMFT are more likely to develop high levels of dental anxiety, which will influence the degree of cooperation during dental procedures. Emotions play an important role in the psychosomatic development of children, and all the factors that contribute to the modeling of these emotional states must be known and taken into consideration. The aim of this study was to assess the association between dental anxiety in children with S-ECC and the color preferences for the components of the dental environment to reduce the levels of dental anxiety during medical visits. For this study, 91 children between 3 and 6 years of age diagnosed with S-ECC were selected from the Pediatric Dentistry Department of UMFST from Targu Mures and from a private dental office. The level of dental anxiety was determined by measuring the pulse rate, and a questionnaire was completed to establish the color preferences for the dental office environment and the dentist's attire. For this purpose, six different colors and their variants with three shades less intensity were chosen by using RGB (Red, Green, and Blue) identification codes for each color. The results showed that there was a statistically significant difference between the age of the subjects and dental anxiety levels, but there was no significant correlation between the DMFT score and dental anxiety. Also, the results showed that there was no significant difference between girls and boys when choosing the colors preferred by them for the dental office, but when comparing the colors that represented happiness, significant statistical difference was found between the girls' and boys' groups (p = 0.0039). For all the subjects, the colors associated with happiness were light yellow and pink, while the colors associated with anxiety were red and dark blue. The data obtained showed that dental anxiety is strongly influenced by age, and an important role in inducing positive emotions is played by the dental environment if dressed in specific colors in order to reduce dental anxiety and create familiar conditions, especially for young children with S-ECC.

Tunable Chemochromism and Elastic Properties in Intercalated MoO3: Au-, Cr-, Fe-, Ge-, Mn-, and Ni-MoO3.

Chemical tunability of the elastic constants of α-MoO3, a two-dimensional layered oxide, is demonstrated with mutability on the order of tens of GPa, simply by choice of a metal intercalant including Au, Cr, Fe, Ge, Mn, and Ni. Using Brillouin laser light scattering from confined acoustic phonons in nanometer-thick materials, the in-plane angular dispersion of the quantized acoustic phonon branches of 2D layered, intercalated MoO3 is measured and used to determine the bulk modulus (K), Young's moduli (E11, E22, and E33), each of the nine independent elastic tensor elements (cij), and the thickness. Intercalation of metals generally reduces the anisotropy in MoO3 except in Ge-MoO3, for which the in-plane longitudinal elastic anisotropy is unaffected. Chemochromism from transparent white (MoO3 and Fe-MoO3) to near black (Ni-MoO3) to brilliant dark blue (Ge-MoO3) is demonstrated and is associated with a reduction in electronic band gap with intercalation and an increase in absorption >600 nm for some intercalants (Cr-, Ge-, and Mn-MoO3).

Active Language Modulates Color Perception in Bilinguals

AbstractColor terms divide the color spectrum differently across languages. Previous studies have reported that speakers of languages that have different words for light and dark blue (e.g., Russian siniy and goluboy) discriminate color chips sampled from these two linguistic categories faster than speakers of languages that use one basic color term for blue (e.g., English blue). This effect has been reported to be disrupted when participants engaged in a verbal interference task, suggesting that active language use can modulate the linguistic category effect. The current study provided a stringent test of this hypothesis by examining color discrimination under verbal interference in bilinguals speaking Lithuanian (two blue categories) and Norwegian (one blue category). The results revealed that the language activated during verbal interference had a significant impact on bilinguals’ color discrimination. Specifically, Lithuanian–Norwegian bilinguals exhibited a color category effect only when performing the task under verbal interference in Lithuanian but not in Norwegian. This demonstrated, within the same individuals, the momentary effect of active language processing on color perception.

Near-infrared reflective Mg0.5Co0.5-xMnxAl2O4 black pigment synthesized by spray pyrolysis: Optimization of composition and calcination temperature

Co/Mn co-substituted MgAl2O4 pigments were spray pyrolysis, and their crystal structure and optical properties were characterized with changing the Co/Mn ratio and synthesis temperature. Regardless of the Co/Mn ratio, the resulting pigments showed spinel structured MgAl2O4 phase without any impurity phase. The synthesized Mg0.5Co0.5Al2O4 and Mg0.5Mn0.5Al2O4 showed a dark blue and brown color due to the visible light absorption by the 4A2(F) → 4T1(P) transition of Co2+ and the d-d transition of Mn2+, respectively. The black colored pigment was achieved by simultaneous substituting Co2+ and Mn2+ in the Mg2+ tetrahedral site in MgAl2O4. The optical band gap of the Mg0.5Co0.5-xMnxAl2O4 pigment decreased linearly from 3.08 eV (x = 0) to 2.46 eV (x = 0.4) as the Mn2+ content increased. As a result, Mg0.5Co0.1Mn0.4Al2O4 uniformly absorbed the entire visible light and had a black color (L* = 28.10, C* = 1.68). In terms of obtaining high near-infrared reflectance and good blackness, the optimal calcination temperature of Mg0.5Co0.1Mn0.4Al2O4 was determined to be 900 °C. The optimized Mg0.5Co0.1Mn0.4Al2O4 black pigment had a good LiDAR reflectance (38 % at 905 nm) and excellent chemical stability, and showed improved heat shielding performance compared to carbon black using in black vehicles.

Synchronous Electrochromism and Electrofluorochromism in a Zirconium Pyrenetetrabenzoate Metal–Organic Framework

AbstractRedox‐active materials that exhibit both electrochromism and electrofluorochromism have great potential as multifunctional elements in optoelectronics. Here, in situ spectroelectrochemistry is presented on NU‐1000, a zirconium pyrenetetrabenzoate metal–organic framework. A thin film of NU‐1000 exhibits reversible color changes between light yellow and dark blue when subjected to an alternating electrochemical potential. In situ fluorescence excitation‐emission spectral mapping elucidates a dominant blue emission of highly fluorescent electrochromic NU‐1000 that is being quenched via an oxidation reaction. Density‐functional theory calculations reveal the forbidden optical transition between the singly occupied molecular orbital (SOMO) and the lowest unoccupied molecular orbital (LUMO) in the oxidized linker as the cause of the quenching. Double potential step chronoamperometry measures response times as fast as a dozen seconds and excellent switching stability over 500 cycles without noticeable attenuation of the color contrast. These findings provide valuable insight into the electrochromism and electrofluorochromism in metal–organic frameworks, offering exciting opportunities for developing advanced multifunctional porous materials with potential applications in optoelectronics and sensing.