Search Results (1,048)

This work presents a comprehensive study of the structural, luminescent, and photoconversion properties of epitaxial composite phosphor converters based on single crystalline films of Ce³⁺-activated Ca_2−xY_1+xMg_1+xSc_1−xSi₃O₁₂:Ce (x = 0–0.25) (CYMSSG:Ce) garnet, grown using the liquid phase epitaxy (LPE) method on single-crystal Y₃Al₅O₁₂ (YAG) and YAG:Ce substrates. The main goal of this study is to elucidate the structure–composition–property relationships that influence the photoluminescence and photoconversion efficiency of these film–substrate composite converters, aiming to optimize their performance in high-power white light-emitting diode (WLED) applications. Systematic variation in the Y³⁺/Sc³⁺/Mg²⁺ cationic ratios within the garnet structure, combined with the controlled tuning of film thickness (ranging from 19 to 67 µm for CYMSSG:Ce/YAG and 10–22 µm for CYMSSG:Ce/YAG:Ce structures), enabled the precise modulation of their photoconversion properties. Prototypes of phosphor-converted WLEDs (pc-WLEDs) were developed based on these epitaxial structures to assess their performance and investigate how the content and thickness of SCFs affect the colorimetric properties of SCFs and composite converters. Clear trends were observed in the Ce³⁺ emission peak position, intensity, and color rendering, induced by the Y³⁺/Sc³⁺/Mg²⁺ cation substitution in the film converter, film thickness, and activator concentrations in the substrate and film. These results may be useful for the design of epitaxial phosphor converters with tunable emission spectra based on the epitaxially grown structures of garnet compounds. Full article

We have conducted a first-time investigation into the multiferroic properties and band gap behavior of ${\mathrm{CuFeO}}_2$ doped with Al, Ga, and In ions at the Fe site, employing a microscopic model and Green’s function formalism. The tunability of the band gap across a broad energy spectrum highlights the potential of perovskite materials for advanced applications, including photovoltaics, photodetectors, lasers, light-emitting diodes, and high-energy particle sensors. The disparity in ionic radii between the dopant and host ions introduces local lattice distortions, leading to modifications in the exchange interaction parameters. As a result, the influence of ion doping on various properties of ${\mathrm{CuFeO}}_2$ has been elucidated at microscopic level. Our findings indicate that Al doping enhances magnetization and reduces the band gap energy. In contrast, doping with Ga or In results in a decrease in magnetization and an increase in band gap energy. Additionally, it is demonstrated that ferroelectric polarization can be induced either via external magnetic fields or by Al substitution at the Fe site. The theoretical results show good qualitative agreement with experimental data, confirming the validity of the proposed model and method. Full article

The transport properties of one-dimensional van der Waals nanodevices composed of carbon nanotubes (CNTs), hexagonal boron nitride (hBN) nanotubes, and molybdenum dichalcogenide (MoX₂) nanotubes were investigated within the framework of density functional theory (DFT). It was found that in nanodevices based on MoS₂(24,24) and MoTe₂(24,24), the effect of resonant tunneling is suppressed due to electron–phonon scattering. This suppression arises from the fact that these materials are semiconductors with an indirect band gap, where phonon participation is required to conserve momentum during transitions between the valence and conduction bands. In contrast, nanodevices incorporating MoSe₂(24,24), which possesses a direct band gap, exhibit resonant tunneling, as quasiparticles can tunnel between the valence and conduction bands without a change in momentum. It was demonstrated that the presence of vacancy defects in the CNT segment significantly degrades quasiparticle transport compared to Stone–Wales (SW) defects. Furthermore, it was revealed that resonant interactions between SW defects in MoTe₂(24,24)–hBN(27,27)–CNT(24,24) nanodevices can enhance the differential conductance under certain voltages. These findings may be beneficial for the design and development of nanoscale diodes, back nanodiodes, and tunneling nanodiodes. Full article

Ginger (Zingiber officinale Roscoe) has been widely recognized for its antioxidant properties, primarily attributed to its phenolic compounds such as gingerols and shogaols. However, limited data exist regarding how different pharmaceutical forms influence the bioaccessibility and antioxidant efficacy of these compounds. This study aimed to evaluate the antioxidant capacity and bioaccessibility of ginger in different pharmaceutical forms—capsules (20 mg, 40 mg, and 80 mg), a pure powdered extract, and a liquid formulation—standardized to ≥6% gingerols. The phenolic profile of each formulation was characterized using HPLC-DAD (High-Performance Liquid Chromatography with Diode Array Detection), followed by the evaluation of antioxidant capacity through DPPH (2,2-Diphenyl-1-picrylhydrazyl) and ORAC (Oxygen Radical Absorbance Capacity) assays, and the assessment of bioaccessibility via an in vitro digestion model. The results demonstrated that antioxidant activity was positively correlated with extract concentration and was highest in the liquid formulation (426.0 ± 0.05 µmol Trolox equivalents (TE) and 11,336.7 ± 0.20 µmol TE in the DPPH and ORAC assays, respectively). The bioaccessibility of 6-gingerol and 6-shogaol significantly increased in the liquid form, reaching 23.44% and 11.31%, respectively, compared to ≤4% in the pure extract. These findings highlight the influence of the formulation matrix on compound release and support the use of liquid preparations to enhance the functional efficacy of ginger-derived nutraceuticals. This standardized comparative approach, using formulations derived from the same extract, offers new insights into how the delivery matrix influences the functional performance of ginger compounds, providing guidance for the development of more effective nutraceutical strategies. Full article

The design of nanoscale electronic components remains a major challenge because we have limited control over the chemical and physical properties of their molecular constituents. Even subtle structural or compositional modifications can significantly alter their electronic behavior. Consequently, updating a molecular component often necessitates developing a new model from scratch. In this study, we present a comprehensive analysis of the rectification properties of a promising molecular diode initially proposed by Aviram and Van Dyck. The model has been systematically decomposed into fundamental building blocks, enabling the electron transport process to be examined both as an integrated event and as a sum of cooperative interactions. Our findings reveal that certain motifs—such as the D-σ-A architecture—play a significant role in rectification. However, achieving high-performance molecular rectifiers also requires cooperative interplay with other structural elements that contribute to rectification, such as asymmetric molecule–metal contacts. In this study, we conduct a detailed investigation of the roles these elements play in shaping the rectifying characteristics, and we further interpret their effects by analyzing the dominant transport channels under forward and backward bias conditions. This deeper understanding of the transport mechanism offers greater control over the system and opens the door for rational design strategies for improving rectification efficiency in future molecular devices. Full article

Apricot is one of the most important Mediterranean fruits with high diversity and fruit quality properties, being an excellent raw material for polyphenol compounds. This study aimed to determine the anthocyanin, quercetin glycoside and phenolic acid contents in new apricot genotypes from the breeding program at the Instituto Valenciano de Investigaciones Agrarias, confirming the potential of the ‘Goldrich’ cultivar to be a parental donor for increasing the antioxidant content, which would, in turn, enhance fruit quality. Phenolic composition of the apricot accessions is strongly genotype-dependent, with the concentrations of overall total phenolic compounds ranging from 770 to 260 mg 100 g⁻¹ DW, reflecting significant genetic diversity. ‘Goldrich’ contributed to the polyphenol content; however, its influence varied across derived varieties, with ‘GG9310’ and ‘GG979’ enhancing the shikimic acid pathway and accumulating high levels of total phenolics. In contrast, ‘Mitger’ and ‘HG9850’ stood out for high anthocyanin synthesis, despite their lower levels of flavonols and phenolic acids. The predominant anthocyanin was cyanidin-3-O-rutinoside, followed by cyanidin-3-O-glucoside and peonidin-3-O-rutinoside in smaller amounts. Other phenolics were rutin and quercetin-3-O-glucuronide, as well as neochlorogenic and chlorogenic acids. The PCA model was applied to all data to identify the most attractive cultivars, and chromatographic analysis was performed in a short time using Ultra-High-Performance Liquid Chromatography (UHPLC) with diode array and mass spectrometric detection. Apricot peel is an excellent source of nutraceutical compounds with a chemical composition strongly determined by the cultivar. Results can help establish authenticity markers for apricot cultivars. Full article

Natural colorants, with their sustainable origins, offer a promising alternative for various applications. Advanced studies have unveiled the remarkable properties, resilience, and durability of these ancient dyes, which our ancestors developed through sustainable material processing. This serves as a testament to the potential of sustainable solutions in our field. As part of our research, we prepared three medieval temperas using gum arabic, parchment glue, and casein glue. These tempera were explicitly designed to protect the purples obtained from Chrozophora tinctoria extracts. A comprehensive multi-analytical approach guides our research on natural colorants. Central to this approach is the use of molecular fluorescence by microspectrofluorimetry, a key tool in our study. By analyzing the emission and excitation spectra in the visible range, we can identify specific formulations. This method is further supported by fingerprinting techniques, including Fourier Transform Infrared Spectroscopy (FTIR) and High-Performance Liquid Chromatography with Diode Array Detection (HPLC-DAD). These are further complemented by Fiber Optics Reflectance Spectroscopy (FORS) and colorimetry. Building on our understanding of orcein purples, we have extended our research to purples derived from Chrozophora tinctoria extracts. Our findings reveal the unique properties of Chrozophora tinctoria, which can be accurately distinguished from orcein purples, highlighting the distinctiveness of each. Full article

Transparent conductive electrodes (TCEs) are essential components in modern optoelectronic devices, including organic light-emitting diodes and solar cells, sensors, and flexible displays. Indium tin oxide has been the dominant material for TCEs due to its high transparency and conductivity. However, its brittleness, high cost, and increasingly limited availability pose significant challenges for electronics. Crack-template (CT)-assisted fabrication has emerged as a promising technique to develop metal mesh-based TCEs with superior mechanical flexibility, high conductivity, and excellent optical transmittance. This technique leverages the spontaneous formation of random and continuous microcrack networks in sacrificial templates, followed by metal deposition (e.g., Cu, Ag, Al, etc.), to produce highly conductive, scalable, and low-cost electrodes. Various crack formation strategies, including controlled drying of polymer suspensions, mechanical strain engineering, and thermal processing, have been explored to tailor electrode properties. Recent studies have demonstrated that crack-templated TCEs can achieve transmittance values exceeding 85% and sheet resistances below 10 Ω/sq, with mesh line widths as low as ~40 nm. Moreover, these electrodes exhibit enhanced stretchability and robustness under mechanical deformation, outperforming ITO in bend and fatigue tests. This review aims to explore recent advancements in CT engineering, highlighting key fabrication methods, performance metrics across different metals and substrates, and presenting examples of its applications in optoelectronic devices. Additionally, it will examine current challenges and future prospects for the widespread adoption of this emerging technology. Full article

Titanium dioxide (TiO₂) is a wide-bandgap semiconductor material with broad application potential, known for its excellent photocatalytic performance, high chemical stability, low cost, and non-toxicity. These properties make it highly attractive for applications in photovoltaic energy, environmental remediation, and optoelectronic devices. For instance, TiO₂ is widely used as a photocatalyst for hydrogen production via water splitting and for degrading organic pollutants, thanks to its efficient photo-generated electron–hole separation. Additionally, TiO₂ exhibits remarkable performance in dye-sensitized solar cells and photodetectors, providing critical support for advancements in green energy and photoelectric conversion technologies. Boron-doped diamond (BDD) is renowned for its exceptional electrical conductivity, high hardness, wide electrochemical window, and outstanding chemical inertness. These unique characteristics enable its extensive use in fields such as electrochemical analysis, electrocatalysis, sensors, and biomedicine. For example, BDD electrodes exhibit high sensitivity and stability in detecting trace chemicals and pollutants, while also demonstrating excellent performance in electrocatalytic water splitting and industrial wastewater treatment. Its chemical stability and biocompatibility make it an ideal material for biosensors and implantable devices. Research indicates that the combination of TiO₂ nanostructures and BDD into heterostructures can exhibit unexpected optical and electrical performance and transport behavior, opening up new possibilities for photoluminescence and rectifier diode devices. However, applications based on this heterostructure still face challenges, particularly in terms of photodetector, photoelectric emitter, optical modulator, and optical fiber devices under high-temperature conditions. This article explores the potential and prospects of their combined heterostructures in the field of optoelectronic devices such as photodetector, light emitting diode (LED), memory, field effect transistor (FET) and sensing. TiO₂/BDD heterojunction can enhance photoresponsivity and extend the spectral detection range which enables stability in high-temperature and harsh environments due to BDD’s thermal conductivity. This article proposes future research directions and prospects to facilitate the development of TiO₂ nanostructured materials and BDD-based heterostructures, providing a foundation for enhancing photoresponsivity and extending the spectral detection range enables stability in high-temperature and high-frequency optoelectronic devices field. Further research and exploration of optoelectronic devices based on TiO₂-BDD heterostructures hold significant importance, offering new breakthroughs and innovations for the future development of optoelectronic technology. Full article

Skin aging is a complex process influenced by several factors, including UV exposure, environmental stressors, and lifestyle choices. The demand for effective, natural skincare products has driven research into plant-based oils rich in bioactive compounds. Rosehip oil has garnered attention for its high content of carotenoids, phenolics, and antioxidants, which are known for their anti-aging, photoprotective, and skin-rejuvenating properties. Despite the growing interest in rosehip oil, limited studies have investigated its efficacy on human skin using advanced imaging technologies. This study aims to fill this gap by evaluating the efficacy of cold-pressed Rosa canina seed oil on facial skin characteristics, specifically wrinkles, ultraviolet (UV) spot reduction, and erythema mitigation, using imaging technologies (the VISIA analysis system). Seed oil pressed from R. canina collected from the Băișoara area of Cluj County has been selected for this study due to its high carotenoid, phenolic, and antioxidant contents. The oil has also been analyzed for the content of individual carotenoids (i.e., lutein, lycopene, β Carotene, and zeaxanthin) using HPLC-DAD (High-Performance Liquid Chromatography—Diode Array Detector), along with lutein and zeaxanthin esters and diesters. After the preliminary screening of multiple Rosa species for carotenoid, phenolic, and antioxidant contents, the R. canina sample with the highest therapeutic potential was selected. A cohort of 27 volunteers (aged 30–65) underwent a five-week treatment protocol, wherein three drops of the selected rosehip oil were topically applied to the face daily. The VISIA imaging was conducted before and after the treatment to evaluate changes in skin parameters, including the wrinkle depth, UV-induced spots, porphyrins, and texture. Regarding the bioactivities, rosehip oil showed a significant total carotenoids content (28.398 μg/mL), with the highest levels in the case of the β-carotene (4.49 μg/mL), lutein (4.33 μg/mL), and zexanthin (10.88 μg/mL) contents. Results indicated a significant reduction in mean wrinkle scores across several age groups, with notable improvements in individuals with deeper baseline wrinkles. UV spots also showed visible declines, suggesting ideal photoprotective and anti-pigmentary effects attributable to the oil’s high vitamin A and carotenoid content. Porphyrin levels, often correlated with bacterial activity, decreased in most subjects, hinting at an additional antimicrobial or microbiome-modulatory property. However, skin responses varied, possibly due to individual differences in skin sensitivity, environmental factors, or compliance with sun protection. Overall, the topical application of R. canina oil appeared to improve the facial skin quality, reduce the appearance of age-related markers, and support skin health. These findings reinforce the potential use of rosehip oil in anti-aging skincare formulations. Further long-term, large-scale studies are warranted to refine dosing regimens, investigate mechanisms of action, and explore synergistic effects with other bioactive compounds. Full article

Background: Diode lasers are valuable in oral surgery due to their excellent hemostasis, minimum post-operative pain, and minimally invasive procedures. A dual-wavelength diode laser in dentistry combines two distinct wavelengths, typically 450 nm and 808 nm, to provide a versatile approach to soft tissue procedures. This ex vivo study investigated the quantity of thermal effects of a dual-wavelength diode laser on porcine lingual mucosa to determine the optimal laser parameters for oral soft tissue biopsies and to improve the reliability of histological evaluation. The presence of thermal damage in the prelesional margins may compromise the diagnostic accuracy, particularly in cases of suspected malignancy. Methods: Thirty-six porcine lingual mucosa samples were excised using a diode laser (Wiser 3, Doctor Smile) in continuous wave (CW) and pulsed wave (PW) modes at average powers of 2, 3, and 4 W. The samples, preserved in 5% buffered formalin, underwent histological evaluation to measure epithelial and connective tissue damage. Results: The study demonstrated variable thermal effects depending on the laser mode and power settings. Minimal epithelial damage (0.62 mm) was observed at 2 W CW, while maximum damage (3.12 mm) occurred at 4 W pulsed wave (PW). Connective tissue exhibited slightly greater damage than epithelial tissue, with minimal damage (0.53 mm) at 4 W CW and maximum damage (3.19 mm) at 4 W pulsed wave (PW). Statistical analyses were performed using t-tests and ANOVA and revealed significant differences in tissue damage between certain groups, highlighting the impact of laser parameters on thermal effects. Conclusions: The dual-wavelength diode laser seems to have good surgical properties and is suitable for managing complex clinical cases. Although the low power average showed minimal thermal damage, for the importance of the diagnosis of suspected lesions of malignancy, a 2 mm prelesional margin should be maintained. Full article

Background: Diabetic foot ulcers (DFUs) affect 25% of diabetes patients, with high risks of amputation (70%), recurrence (65% within 3–5 years), and mortality (50–70% at 5-years). Current treatments are limited by persistent inflammation, oxidative stress, and cost barriers. This study evaluates a bioactive dressing combining a natural latex-based (NLB) biomembrane (Hevea brasiliensis) with curcumin-loaded liposomes, exhibiting angiogenic and antimicrobial properties, and red LED (light-emitting diode) phototherapy (635–640 nm) to address these challenges. Methods: A pilot clinical trial randomized 15 DFU participants into three groups: Control (CG, n = 5, standard care); Experimental Group 1 (EG1, n = 5, NLB + LED, daily treatment); and Experimental Group 2 (EG2, n = 5, NLB-curcumin liposomes + LED, daily treatment). Outcomes included wound closure, inflammatory/oxidative markers, and therapy feasibility. Assessments at D0, D22, and D45 included hematological/biochemical profiling, reactive oxygen species (ROS), and wound area measures. Results: On day 45, GE2 showed an average ulcer contraction of 89.8%, while CG showed 32.8%, and GE1 showed 9.7%. Systemic ROS and biomarkers (C-reactive protein, leukocytes) showed no significant changes (p > 0.05), though transient inflammatory spikes occurred. The combined therapy (EG2) accelerated healing without direct biomarker correlations. Conclusions: These findings highlight the potential of this combined therapy as an accessible, cost-effective DFU treatment, warranting larger studies to optimize home-based protocols and elucidate mechanisms. Full article

4H-silicon carbide (4H-SiC) is a cornerstone for next-generation optoelectronic and power devices owing to its unparalleled thermal, electrical, and optical properties. However, its chemical inertness and low dopant diffusivity for most dopants have historically impeded effective doping. This study unveils a transformative laser-assisted boron doping technique for n-type 4H-SiC, employing a pulsed Nd:YAG laser (λ = 1064 nm) with a liquid-phase boron precursor. By leveraging a heat-transfer model to optimize laser process parameters, we achieved dopant incorporation while preserving the crystalline integrity of the substrate. A novel optical characterization framework was developed to probe laser-induced alterations in the optical constants—refraction index ($\mathrm{n}$) and attenuation index ($\mathrm{k}$)—across the MIDIR spectrum (λ = 3–5 µm). The optical properties pre- and post-laser doping were measured using Fourier-transform infrared spectrometry, and the corresponding complex refraction indices were extracted by solving a coupled system of nonlinear equations derived from single- and multi-layer absorption models. These models accounted for the angular dependence in the incident beam, enabling a more accurate determination of $\mathrm{n}$ and $\mathrm{k}$ values than conventional normal-incidence methods. Our findings indicate the formation of a boron-acceptor energy level at 0.29 eV above the 4H-SiC valence band, which corresponds to λ = 4.3 µm. This impurity level modulated the optical response of 4H-SiC, revealing a reduction in the refraction index from 2.857 (as-received) to 2.485 (doped) at λ = 4.3 µm. Structural characterization using Raman spectroscopy confirmed the retention of crystalline integrity post-doping, while secondary ion mass spectrometry exhibited a peak boron concentration of 1.29 × 10¹⁹ cm⁻³ and a junction depth of 450 nm. The laser-fabricated p–n junction diode demonstrated a reverse-breakdown voltage of 1668 V. These results validate the efficacy of laser doping in enabling MIDIR tunability through optical modulation and functional device fabrication in 4H-SiC. The absorption models and doping methodology together offer a comprehensive platform for paving the way for transformative advances in optoelectronics and infrared materials engineering. Full article

Recent advancements in thermally activated delayed fluorescence (TADF) materials and mechanochromic materials have significantly enhanced the efficiency and versatility of light-emitting electrochemical cells (LECs) and organic light-emitting diodes (OLEDs). TADF materials have enabled efficiency improvements, achieving an internal quantum efficiency (IQE) of nearly 100% by utilizing both singlet and triplet excitons. Meanwhile, mechanochromic materials exhibit reversible optical changes upon mechanical stimuli, making them promising for stress sensing, encryption, and flexible electronics. The synergistic integration of TADF and mechanochromic materials in OLEDs and LECs has led to enhanced efficiency, stability, and multifunctionality in next-generation lighting and display technologies. This narrative review explores recent breakthroughs in devices that incorporate both TADF and mechanochromic materials as emitters. Particular attention is given to the molecular design that enable both TADF and mechanochromic properties, as well as optimal device structures and performance parameters. Moreover, this review discusses the only LEC fabricated so far using a TADF-mechanochromic emitter, highlighting its performance and potential. Finally, the report concludes with an outlook on the future commercial applications of these materials, particularly in wearable electronics and smart display technologies. Full article

Lead halide perovskites (LHPs) have superior luminescent properties, but their toxicity hinders their commercialization, arousing interests in tin halide perovskites as environmentally friendly substitutes for LHPs. Herein, we synthesized a series of two-dimensional tin halide perovskite ODASnBr_4-xI_x (ODA denotes 1,8-octanediammonium, X = 0, 1, 2, 3, 4) microcrystals via an aqueous-phase method. The differences between ODASnI₄ and ODASnBr₄ in luminescent properties and morphological characteristics were systematically discussed for the first time and attributed to light-driven ligand-to-metal charge transfer. The prepared ODASnBr₄ has a PL peak at 567 nm and a PL QY of 99%, and the white light-emitting diodes fabricated with ODASnBr₄ and commercial blue phosphors realized a luminous efficacy of up to 96.27 lm/W, which demonstrated the remarkable potential of ODASnBr₄ microcrystals for high-efficiency white light-emitting diode applications. Full article