Search Results (37)

In this work, methyl viologen (MV) was adsorbed into the nanopores of Si/Al H-β-zeolite via cation exchange. The resulting MV@β-zeolite possessed absorption/fluorescence dual-mode and photo/chemical synergistic stimuli-responsive chromism. Owing to the acidic surrounding provided by β-zeolite, the chromism of MV required the synergistic stimuli of UV irradiation and a chemical reductant (such as Na₂SO₃). UV irradiation induced single electron transfer from the chemical reductant to MV@β-zeolite, leading to enhanced absorption at 610 nm together with a daylight color change from pale yellow to blue. Meanwhile, the nanopores of β-zeolite inhibited aggregation-caused quenching of MV, enabling MV to emit cyan fluorescence at 500 nm. After the single electron transfer of the chemical reductant under UV irradiation, the cyan fluorescence of MV@β-zeolite was quenched. Additionally, MV@β-zeolite exhibited a short stimulus response time (250 s) and good color change reversibility. These findings in this work provide valuable insights into the design of multi-mode and synergistic stimuli-responsive viologen-based chromic materials, particularly for applications in secure high-throughput information storage, high-level anti-counterfeiting and multi-target multi-mode sensing. Full article

Fluorescence tracing effectively identifies asphalt stripping on aggregate surfaces, showing promise for characterizing asphalt–aggregate adhesion in pavement performance detection. However, this method’s effectiveness depends on sensor parameters and ambient conditions. This study developed a fluorescence tracing image acquisition system and employed a five-factor, six-level orthogonal experiment to optimize sensor parameters. We compared multilayer perceptron (MLP) regression, Kolmogorov–Arnold networks regression, and Laplacian sharpening for image quality assessment, with MLP proving superior. The results indicate that (1) image quality is primarily influenced by camera aperture, followed by focal length, exposure time, UV light–camera distance, and object–camera distance; (2) the optimal parameters were 100,000 ms exposure time, 8 mm focal length, 44 cm object–camera distance, aperture of 6, and 30 cm UV light–camera distance; (3) a green background with combined UV and daylight illumination in a glass box yielded the highest image quality score (0.7084); and (4) images acquired under these optimized conditions displayed fluorescence tracing and asphalt regions with superior clarity. This study optimizes the fluorescence tracing method for quantifying the adhesion between asphalt and aggregate and promotes an intellectual approach to material performance detection in pavement engineering. Full article

A novel method for the development of fingerprints in environmentally friendlier conditions and on porous surfaces with 1,8-diazafluoren-9-one (DFO) is reported herein. DFO, a fluorescent dye was formulated in glacial acetic acid, methanol, and a minimum amount of methylene chloride. The DFO reacted with amino acid components of latent prints, resulting in a fluorescent species that was visualized under daylight, UV light at 254 nm, 365 nm, and LED at 395–405 nm. The developed prints were photographed using iPhone 11 and IOS 17.4.1. The fluorescent spectra of the species resulting from DFO’s reaction with the amino acid glycine and the wavelengths of maximum excitation (λ_ex = 470 nm) and emission (λ_em = 585 nm) were also reported. The method is suitable for forensic laboratories. Full article

Background/Objectives: Cetuximab, formulated in Erbitux^® (5 mg/mL), is a therapeutic monoclonal antibody (mAb) widely used in several cancer treatments. Currently, there is insufficient knowledge about the behavior of cetuximab with regard to the risk associated with its routine handling or unintentional mishandling in hospitals. Forced degradation studies can simulate these conditions and provide insights into the biophysical and biochemical properties of mAbs. Methods: In this study, we conducted a deep physicochemical and functional characterization of the critical quality attributes of cetuximab in control samples and under controlled degraded conditions, including freeze–thaw cycles, heat, agitation, and light exposure. To achieve this purpose, we used a set of proper analytical techniques, including CD, IT-FS, DLS, SE/UHPLC-UV, UHPLC-MS/MS, and ELISA, to check functionality based on antigen–antibody binding. Results: The results revealed that light exposure was the stress stimuli with the greatest impact on the drug product, leading to the formation of non-natural oligomers, fragmentation, and oxidation of methionine residues. Additionally, cetuximab (Erbitux^®, 5 mg/mL) showed a tendency to aggregate when submitted to 60 °C for 1 h. In terms of functionality, cetuximab (Erbitux^®, 5 mg/mL) samples were found to be affected when subjected to freeze–thaw cycles, 60 °C (1 h), and when exposed to light (daylight with room temperature excursion and accelerated light exposure). Conclusions: Thus, we suggest that Erbitux^® (5 mg/mL) should be shielded from these environmental conditions, as they compromise both the safety and efficacy of the drug product. Full article

Since individuals with severe and profound Intellectual Disabilities (IDs) have no concept of time, it is difficult for them to autonomously maintain daily structures. Those affected are dependent throughout their lives on external care structures. Even though research suggests that individuals with IDs should live in smaller facilities, individuals with higher support needs are more likely to be placed in large institutions and clustered group homes. The aim of this study was to define design criteria and test their applicability to a residential building design whose architecture enables individuals with IDs to develop autonomy through spatially experienced temporality. Qualitative data was collected in a mixed method evidence-based design approach: systematic behavioural observations, structured interviews, focus groups, and the UV-index method. Four design criteria could be described that contribute to an autonomy-promoting temporality: (a) spatial sequencing and repetition, (b) privacy-related variation of spatial dimensions, (c) spatial orchestration of daylight, and (d) constant emotional proximity to the caregiver. The hypothesis of using architecture to promote temporality in clients with IDs and Challenging Behaviour (CB) has proven to be potentially effective in designing a therapeutic environment. Our findings provide valuable data on how long-stay facilities should be designed in the future. Full article

The present work investigates the physicochemical stability of spray paints when irradiated with artificial solar light (at spectral range 300–800 nm). This research highlights the importance of understanding the materials used in street art and public murals, recognising them as a significant component of contemporary cultural heritage. By examining the stability and degradation of spray paints toward solar light exposure, the study aims to contribute to the preservation of contemporary murals, which reflect current social and cultural narratives. A physicochemical approach was employed for the study of spray paints’ physical and thermal properties, as well as the effect of specific photochemical ageing reactions/processes. The photochemical ageing results were compared with reference (unaged) samples. Specifically, a multi-technique approach was applied using stereo microscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle measurement, colorimetry, glossimetry, differential scanning calorimetry (DSC), UV-Vis spectroscopy, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and pyrolysis-GC/MS (Py-GC/MS). The photodegradation of the spray paints occurred from the first 144 h of solar light irradiation, resulting in changes in morphology, colour, gloss, roughness, and wettability. Regarding photochemical stability, ageing seems to affect the binders more than the synthetic organic pigments and the inorganic fillers. In particular, acrylic binders showed small chemical changes, whereas the alkyd, nitrocellulose, and styrene binders underwent severe chemical modification. The results suggest that simulated daylight irradiation prompts the migration of additives toward the surface of the spray paint films. In addition, the results of the analyses on the white spray paints in comparison with the coloured paints (from the same manufacturer) showed that there seems to be an active distinct photoageing mechanism involving titanium dioxide, but the whole issue needs further investigation. Full article

Incorporating Internet of Things (IoT) technology into indoor kale cultivation holds significant promise for revolutionizing organic farming methodologies. While numerous studies have investigated the impact of environmental factors on kale growth in IoT-based smart agricultural systems, such as temperature, humidity, and nutrient levels, indoor ultraviolet (UV) LED light’s operational efficiencies and advantages in organic farming still need to be explored. This study assessed the efficacy of 15 UV light-controlling indoor experiments in three distinct lighting groups: kale cultivated using conventional household LED lights, kale cultivated using specialized indoor UV lights designed for plant cultivation, and kale cultivated using hybrid household and LED grow lights. The real-time IoT-based monitoring of light, soil, humidity, and air conditions, as well as automated irrigation using a water droplet system, was employed throughout the experiment. The experimental setup for air conditioning maintained temperatures at a constant 26 degrees Celsius over the 45-day study period. The results revealed that a combination of daylight household lights and indoor 4000 K grow lights scored the highest, indicating optimal growth conditions. The second group exposed to warm white household and indoor grow red light exhibited slightly lower scores but larger leaf size than the third group grown under indoor grow red light, likely attributable to reduced light intensity or suboptimal nutrient levels. This study highlights the potential of indoor UV LED light farming to address challenges posed by urbanization and climate change, thereby contributing to efforts to mitigate agricultural carbon emissions and enhance food security in urban environments. This research contributes to positioning kale as a sustainable organic superfood by optimizing kale cultivation. Full article

The homomorphic substitution of the garnet group is common in nature. Two rare color-changing andradite garnets are studied in this paper. One color changes from yellowish-green in the presence of daylight to maroon under incandescent light; the other color changes from brownish yellow to brownish red. In this study, conventional gemological instruments, infrared (IR) spectroscopy, ultraviolet–visible–near infrared (UV–Vis–NIR) spectroscopy, Raman spectroscopy, and electron probe microanalysis (EPMA) were used to explore the gemology and coloration mechanisms of color-changing garnets. Experiments revealed that the color-changing gemstones in the study are andradite garnets. There are two transmission windows in the UV–Vis spectrum: the red region (above 650 nm) and the green region (centered at 525 nm). The chemical compositional analysis indicates that the samples are very low in Cr (<1 ppm) and high in Fe²⁺ (from 2.31 wt.% to 4.66 wt.%). The combined spectra and chemical compositional analysis show that Fe²⁺ is the main cause of the color change. Based on the IR spectrum (complex water peaks), UV–Vis–NIR spectrum (similar to that of Namibian andradite garnet), and chemical compositional analysis (low Cr content), it is concluded that color-changing andradite may be related to skarn rock genesis. Full article

In this work, two stilbene derivatives with different substituents on the phenolic core (phenyl and dimethoxyphenyl) were prepared. The fluorosolvatochromic response of their N-propylated derivatives was studied in a solution of twelve different solvents using UV–Vis absorption and fluorescence emission spectra. Both stilbazolium dyes showed a significant negative solvatochromic effect, with a hypsochromic shift in the visible absorption band of approximately 232 nm and 265 nm for phenyl and the dimethoxyphenyl derivative, respectively, when the solvent was changed from water to pyridine. The stilbene derivatives were subsequently N-alkylated with (3-iodopropyl)trimethoxysilane and covalently anchored to the silica surface. The fluorosolvatochromic response of the prepared silicas compared to N-propylated dyes was then evaluated colorimetrically under daylight and UV illumination. The fluorosolvatochromic behaviour of the anchored dyes was preserved on the silica surface; therefore, the modified silicas could be used for the visual detection of colourless liquids. Full article

In this study, doxorubicin was loaded in a chitosan–albumin nanogel with the aim of improving its stability and exploring the potential of the system in the treatment of skin cancer. Infrared spectroscopy and X-ray diffraction confirmed the encapsulation of the drug. Transmission electron microscopy revealed the spherical shape of the nanogel particles. The drug-loaded nanogel was characterized with a small diameter of 29 nm, narrow polydispersity (0.223) and positive zeta potential (+34 mV). The exposure of encapsulated doxorubicin to light (including UV irradiation and daylight) did not provoke any degradation, whereas the nonencapsulated drug was significantly degraded. In vitro studies on keratinocytes (HaCaT) and epidermoid squamous skin carcinoma cells (A-431) disclosed that the encapsulated doxorubicin was more cytotoxic on both cell lines than the pure drug was. More importantly, the cytotoxic concentration of encapsulated doxorubicin in carcinoma cells was approximately two times lower than that in keratinocytes, indicating that it would not affect them. Thus, the loading of doxorubicin into the developed chitosan–albumin nanogel definitely stabilized the drug against photodegradation and increased its antineoplastic effect on the skin cancer cell line. Full article

The development of smart color-changing wood could facilitate its functional application. Herein, photochromic wood films (PWFs) were synthesized by grafting 1-(2-hydroxyethyl)-3,3-dimethylindolino-6’-nitrobenzopyrylospiran onto the cellulosic skeleton structure of delignified wood using hexamethylene diisocyanate as a bridging linker, followed by the densification process. The microstructural morphology, chemical composition, photochromic properties, and mechanical properties of the prepared PWFs were characterized by scanning electron microscope, Fourier transform infrared spectroscopy, colorimeter, and universal mechanical testing machine. The photochromic capability of the wood film was positively correlated with the grafting amount of spiropyran; the color change is evident when the grafting amount is high. Furthermore, the photochromic and recovery capability of the wood film weakened after sequentially irradiating 40 times using a UV lamp and daylight lamp, which could be partially recovered after a period of rest. However, the wood film strength was negatively correlated with the grafting amount of spiropyran. The grafted spiropyran affected the hydrogen bonding between cellulose nanofibers of the wood film during densification, which caused a reduction in the film strength. However, the strength was still >120 MPa. Meanwhile, temperature and humidity affected the photochromic capability of the wood film. Thus, the developed high-strength PWF has potential applications in various fields, such as intelligent sensing, personalized design, indoor and outdoor architecture, and optoelectronics. Full article

The alexandrite effect is a pivotal optical phenomenon in gemmology, evident in several notable gemstones. However, the manifestation of this effect in apatite from Kazakhstan stands out as both rare and highly sought after. This apatite displays a yellowish-green hue in daylight and transitions to a pinkish-orange shade under incandescent lighting. This research involved analyzing the apatite’s chemical composition using LA-ICP-MS, in addition to obtaining its infrared, Raman, UV-Vis, and fluorescence spectra. From the elemental assessment results, the primary trace elements in the apatite were identified as Na, Mn, and Fe, along with rare-earth elements including Gd, Dy, Ce, Nd, and Sm. The infrared and Raman spectra showcased peaks corresponding to phosphate and hydroxyl groups. The apatite’s alexandrite effect predominantly stems from absorption peaks at 748, 738, 583, 578, and 526 nm in the visible spectrum, all of which are attributed to the rare-earth element, Nd. The fluorescence peaks of the apatite are primarily influenced by elements such as Ce, Eu, Nd, and Mn. Through this research, a theoretical foundation has been laid for the non-destructive identification of apatite exhibiting the alexandrite effect. Full article

Carbon dots (C-dots) are fluorescent nanomaterials, exhibiting excellent structure-dependent optical properties for various types of optical and electrical applications. Although many precursors were used for C-dots production, it is still a challenge to produce high-quality C-dots using environmentally-friendly natural precursors. In this work, multiple-colored colloidal C-dots were synthesized via a heating reaction using natural plant dyes as precursors, for example, Indigo, Carcuma longa, and Sophora japonica L. The as-prepared C-dots have absorption in the UV range of 220 to 450 nm with the typical emission ranging from 350 to 600 nm. The as-obtained C-dots have a quantum yield as high as 3.8% in an aqueous solution. As a proof-of-concept, we used the as-prepared C-dots as fluorescence inks for textile secure printing. The printed patterns are almost invisible under daylight and have distinct and clear patterns under 365 and 395 nm light, proving the great potential in optical anti-counterfeiting. This work demonstrates the advanced strategy for high-performance C-dots production from natural dyes and their potential application in flexible secure printing systems. Full article

Diamond particles have great potential to enhance the mechanical, optical, and thermal properties of diamond–polymer composites. However, the improved properties of diamond–polymer composites depend on the size, dispersibility, and concentration of diamond particles. In the present study, diamond–polymer composites were prepared by adding the microdiamond particles (MDPs) with different concentrations (0.2–1 wt.%) into polymers (acrylate resins) and then subjected to a photocuring process. The surface morphology and topography of the MDPs–polymer composites demonstrated a uniform high-density distribution of MDPs for one wt.% MPDs. Thermogravimetric analysis was employed to investigate the thermal stability of the MDPs–polymer composites. The addition of MDPs has significantly influenced the polymers’ thermal degradation. Absorption and emission spectra of thin layers were recorded through UV/Vis spectrophotometry and spectrofluorimetry. The obtained results revealed a significant increase in the fluorescence intensity of MDPs–polymer composites (at 1 wt.% of MDPs, a 1.5×, 2×, and 5× increase in fluorescence was observed for MDPs–green, MDPs–amber daylight, and MDPs–red resin, respectively) compared with the reference polymer resins. The obtained results of this work show the new pathways in producing effective and active 3D-printed optical elements. Full article

Herein, we report a feasible method for forming barrel-like hybrid Cu(OH)₂-ZnO structures on α-brass substrate via low-potential electro-oxidation in 1 M NaOH solution. The presented study was conducted to investigate the electrochemical behavior of CuZn in a passive range (−0.2 V–0.5 V) and its morphological changes that occur under these conditions. As found, morphology and phase composition of the grown layer strongly depend on the applied potential, and those material characteristics can be tuned by varying the operating conditions. To the best of our knowledge, the yielded morphology of barrel-like structure has not been previously observed for brass anodizing. Additionally, photoactivity under both UV and daylight irradiation-induced degradation of organic dye (methyl orange) using Cu(OH)₂-ZnO composite was explored. Obtained results proved photocatalytic activity of the material that led to degradation of 43% and 36% of the compound in UV and visible light, respectively. The role of Cu(OH)₂ in improving ZnO photoactivity was recognized and discussed. As implied by both the undertaken research and the literature on the subject, cupric hydroxide can act as a trap for photoexcited electrons, and thus contributes to stabilizing electron-hole recombination. This resulted in improved light-absorbing properties of the photoactive component, ZnO. Full article