Effect of blue light emitting diode therapy on recurrent vulvovaginal candidiasis: A randomized assessor-blinded controlled trial.

OBJECTIVE: Vulvovaginal Candidiasis (VVC) is a prevalent genital infection in women of reproductive age and requires effective non-drug therapies. Therefore, this study aimed to investigate the effect of blue light emitting diode (LED) therapy as an alternative treatment for recurrent VVC due to its proven antimicrobial properties. The safety and non-invasiveness of LED therapy make it a promising option for sensitive tissue applications. MATERIALS AND METHODS: This randomized controlled trial recruited 60 women with culture-confirmed VVC. Participants were randomly allocated to two groups. Group A (control group) received standard antifungal treatment with Gynoconazol 0.8% vaginal cream for three consecutive nights (n = 30). Group B (study group) received the same antifungal treatment plus two 60-min sessions of blue LED therapy directed at the vagina and vulva, with the sessions separated by two days (n = 30). Candida count (via CHROMagar™ Candida) and vaginal pH (via AD110-AD111 m) were assessed at baseline and one week after initiating treatment. RESULTS: Post-treatment, group (B) demonstrated a significantly greater reduction in Candida count compared to group (A) (mean difference (MD) 8.267; 95% Confidence Interval (CI) 6.723-9.811; p = 0.0001). However, there was no statistically significant difference in vaginal pH between the groups (MD -0.03; 95% CI -0.244-0.178; p = 0.749). CONCLUSION: Blue LED therapy effectively reduces Candida count in women with recurrent VVC without adversely affecting the vaginal pH, highlighting its safety and efficacy as a treatment modality.

Synthesis and photoluminescent spectroscopic analysis of lanthanum (III) coordinated with 1,10-Phenanthroline: A study of its thermally stable behavior.

A blue-emitting phosphor designed by lanthanum (III) coordinated with two 1,10-Phenanthroline and three nitrate ligands, [La(Phen)2(NO3)3], was obtained by an effective and simple precipitation method. Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (PXRD) revealed the coordination modes in the compound and the chemical structure, crystallizing in a monoclinic system in the C2/c space group. The luminescence properties, absolute quantum yield (ϕ), and luminescence lifetime decay (τ) were determined by photoluminescence spectroscopy. Under a 350 nm excitation, the sample presents three emission bands corresponding to the π* → π transitions belonging to the organic ligand. The luminescence lifetime (τ) was determined through a monoexponentially fit, obtaining a value of 5616 ns. The [La(Phen)2(NO3)3] complex exhibits an absolute quantum yield of 3 % with the same excitation conditions. In addition, the photometric analysis shows that the luminescent response to a 350 nm excitation is that of a blue-emitting high-purity phosphor with 96 % and chromatic coordinates of 0.15, 0.05. The temperature-dependent luminescence properties revealed considerable thermal stability in the 20-150 °C range with a signal loss of 47 % and an activation energy of thermal quenching (ΔE) of 0.13 eV, the first value reported for a lanthanum complex based on 1,10-Phenanthroline.

The Pigmentation of Blue Light is Mediated by Both Melanogenesis Activation and Autophagy Inhibition through OPN3-TRPV1.

Blue light, a high-energy radiation in the visible light spectrum, was recently reported to induce skin pigmentation. In this study, we investigated the involvement of TRPV1-mediated signaling along with OPN3 in blue light-induced melanogenesis, as well as its signaling pathway. Operating downstream target of OPN3 in blue light-induced melanogenesis, blue light activated TRPV1 and upregulated its expression, resulting in calcium influx. [Ca2+] induced activation of CaMKII and MAPK. It also downregulated clusterin expression, leading to the nuclear translocation of PAX3, ultimately affecting melanin synthesis. In addition, blue light interfered with autophagy-mediated regulation of melanosomes by decreasing not only the interaction between CLU and LC3B but the expression of ATF family. These findings demonstrate that the pigmenting effects of blue light are mediated by CaMKII- and MAPK-mediated signaling, as well as CLU-dependent inhibition of autophagy through OPN3-TRPV1-calcium influx, suggesting a new signaling pathway by which blue light regulates melanocyte biology. Furthermore, these results suggest that TRPV1 and CLU could be potential therapeutic targets for blue light-induced pigmentation due to prolonged exposure to blue light.

[Effect of blue range light-emitting diode radiation on platelets and blood coagulation factors in patients with chronic ischemia of lower limbs]. / Vliyanie svetodiodnogo izlucheniya sinego diapazona na trombotsity i faktory svertyvaniya krovi u bol'nykh s khronicheskoi ishemiei nizhnikh konechnostei.

Chronic arterial insufficiency of lower limbs (CAILL) is a common cardiovascular disease that affects 200 million subjects worldwide: from 4 to 12% of people aged 55-70 years and 20% - over 70 years. The cause of blood circulation disorder in this disease is usually a complex of pathological changes including abnormality of vessel walls' anatomical structure or integrity, disorder of blood rheological properties and alterations of its thrombotic potential. Thus, the therapy of patients with CAILL aiming at hemostasis and, in particular, platelets' aggregation is one of the most urgent problems of medicine. OBJECTIVE: To study the effectiveness of blue range visible radiation combined with basic therapy to improve hemostasis in patients with CAILL. MATERIAL AND METHODS: The number of male patients with CAILL equal 63 aged 43-57 years was examined. Blood flow parameters on a fixed part of femoral artery outside the occlusion area were registered based on subjective criteria, number of painless steps and ultrasound doppler flowmetry according to the Fontaine-Pokrovsky classification. The second degree of ischemia was diagnosed in 38 patients, the third degree - in 25 patients. All patients received basic pharmacotherapy. Patients were divided into 2 groups by simple randomization method: control group included 18 patients with II degree of ischemia and 12 patients with III degree of ischemia who received basic pharmacotherapy combined with photohemotherapy (PHT). A set of commonly used laboratory methods for examination of blood coagulation system was applied to assess the effectiveness of PHT. The number of apparently healthy people equal 26 was examined to evaluate normal value of hemostasiological parameters. RESULTS: Basic pharmacological treatment had a certain positive effect on studied hemostasis parameters and its thrombotic component. However, they did not differ statistically significantly from similar parameters before treatment on the 14th day after treatment. As a result of comprehensive therapy the changes in hemostasis system had identical and statistically significant in percentage terms changes compared to norm and baseline in patients' subgroups of study group with II and III degrees of ischemia. In addition, most hemostasis parameters in patients with II degree of ischemia were close to those of apparently healthy volunteers. Hemostasis parameters in patients with III degree of ischemia decreased to the levels of patients with II degree of ischemia before treatment. CONCLUSION: The use of basic pharmacological therapy with optical exposure to blood by blue light allows to correct hemostasis and its thrombotic component in patients with CAILL.

Antimicrobial blue light inactivation of Pseudomonas aeruginosa: Unraveling the multifaceted impact of wavelength, growth stage, and medium composition.

Pseudomonas aeruginosa, a notable pathogen frequently associated with hospital-acquired infections, displays diverse intrinsic and acquired antibiotic resistance mechanisms, posing a significant challenge in infection management. Antimicrobial blue light (aBL) has been demonstrated as a potential alternative for treating P. aeruginosa infections. In this study, we investigated the impact of blue light wavelength, bacterial growth stage, and growth medium composition on the efficacy of aBL. First, we compared the efficacy of light wavelengths 405 nm, 415 nm, and 470 nm in killing three multidrug resistant clinical strains of P. aeruginosa. The findings indicated considerably higher antibacterial efficacy for 405 nm and 415 nm wavelength compared to 470 nm. We then evaluated the impact of the bacterial growth stage on the efficacy of 405 nm light in killing P. aeruginosa using a reference strain PAO1 in exponential, transitional, or stationary phase. We found that bacteria in the exponential phase were the most susceptible to aBL, followed by the transitional phase, while those in the stationary phase exhibited the highest tolerance. Additionally, we quantified the production of reactive oxygen species (ROS) in bacteria using the 2',7'-dichlorofluorescein diacetate (DCFH-DA) probe and flow cytometry, and observed a positive correlation between aBL efficacy and ROS production. Finally, we determined the influence of growth medium on aBL efficacy. PAO1 was cultivated in brain heart infusion (BHI), Luria-Bertani (LB) broth or Casamino acids (CAA) medium, before being irradiated with aBL at 405 nm. The CAA-grown bacteria exhibited the highest sensitivity to aBL, followed by those grown in LB broth, and the BHI-grown bacteria demonstrated the lowest sensitivity. By incorporating FeCl3, MnCl2, ZnCl2, or the iron chelator 2,2'-bipyridine (BIP) into specific media, we discovered that aBL efficacy was affected by the iron levels in culture media.

A prospective, randomized, controlled, double-blind, multi-center study to evaluate the efficacy and safety of a blue light device for the treatment of chronic back pain.

Introduction: Chronic back pain is one of the most prevalent conditions and has a large socio-economic impact. The lack of routine use of non-pharmacological options and issues associated with pharmacological treatments underscore high unmet needs in the treatment of back pain. Although blue light phototherapy has proven efficacy in dermatology, limited information is available about its use in back pain. Methods: In this proof-of-concept, randomized controlled trial, a pain relief patch (PRP) delivered blue light at the site of back pain for 30 min during five treatment sessions. The comparator device delivered green light for 5 s but was worn for 30 min. A follow-up visit took place after the last treatment. The primary objective was to demonstrate the superiority of treatment by PRP, compared to the control device, in reducing pain intensity at the end of the treatment period. The post-treatment visual analog scale (VAS) pain intensity score for each group was calculated across the five treatment sessions and compared to the baseline. Secondary objectives included the disability score (Roland-Morris Disability Questionnaire) and safety. Results: The full analysis set included 171 patients. A statistically significant reduction in pain intensity occurred after the use of PRP (p < 0.02), but the study did not meet its primary objective of a superiority trial aimed at demonstrating a 0.6 cm difference in favor of PRP on the VAS scale. There was no significant change in the disability scores. Subgroup analyses were performed to identify the treatment response by patient characteristics such as pain intensity at baseline and skin type. As expected, safety data showed erythema and skin discoloration in the PRP group but not in the control group. Discussion/conclusion: This trial had multiple limitations that need to be addressed in future research. Although the primary objective was not achieved, this proof-of-concept study provides important efficacy and safety data in relation to the use of blue light in the treatment of chronic back pain and key insights that may support further research on similar devices. Clinical Trial Registration: ClinicalTrials.gov, identifier NCT01528332.

A Comprehensive Systematic Review of the Effects of Photobiomodulation Therapy in Different Light Wavelength Ranges (Blue, Green, Red, and Near-Infrared) on Sperm Cell Characteristics in Vitro and in Vivo.

Around 7% of the male population in the world are entangle with considerable situation which is known as male infertility. Photobiomodulation therapy (PBMT) is the application of low-level laser radiation, that recently used to increase or promote the various cell functions including, proliferation, differentiation, ATP production, gene expressions, regulation of reactive oxygen spices (ROS), and also boost the tissue healing and reduction of inflammation. This systematic review's main idea is a comprehensive appraisal of the literatures on subjects of PBMT consequences in four light ranges wavelength (blue, green, red, near-infrared (NIR)) on sperm cell characteristics, in vitro and in vivo. In this study, PubMed, Google Scholar, and Scopus databases were used for abstracts and full-text scientific papers published from 2003-2023 that reported the application of PBM on sperm cells. Criteria's for inclusion and exclusion to review were applied. Finally, the studies that matched with our goals were included, classified, and reported in detail. Also, searched studies were subdivided into the effects of four ranges of light irradiation, including the blue light range (400-500 nm), green light range (500-600 nm), red light range (600-780 nm), and NIR light range (780-3000 nm) of laser irradiation on human or animal sperm cells, in situations of in vitro or in vivo. Searches with our keywords results in 137 papers. After primary analysis, some articles were excluded because they were review articles or incomplete and unrelated studies. Finally, we use the 63 articles for this systematic review. Our category tables were based on the light range of irradiation, source of sperm cells (human or animal cells) and being in vitro or in vivo. Six% of publications reported the effects of blue, 10% green, 53% red and 31% NIR, light on sperm cell. In general, most of these studies showed that PBMT exerted a positive effect on the sperm cell motility. The various effects of PBMT in different wavelength ranges, as mentioned in this review, provide more insights for its potential applications in improving sperm characteristics. PBMT as a treatment method has significant effectiveness for treatment of different medical problems. Due to the lack of reporting data in this field, there is a need for future studies to assessment the biochemical and molecular effects of PBMT on sperm cells for the possible application of this treatment to the human sperm cells before the ART process.

Exploration of the Graphene Quantum Dots-Blue Light Combination: A Promising Treatment against Bacterial Infection.

Graphene Quantum Dots (GQDs) have shown the potential for antimicrobial photodynamic treatment, due to their particular physicochemical properties. Here, we investigated the activity of three differently functionalized GQDs-Blue Luminescent GQDs (L-GQDs), Aminated GQDs (NH2-GQDs), and Carboxylated GQDs (COOH-GQDs)-against E. coli. GQDs were administrated to bacterial suspensions that were treated with blue light. Antibacterial activity was evaluated by measuring colony forming units (CFUs) and metabolic activities, as well as reactive oxygen species stimulation (ROS). GQD cytotoxicity was then assessed on human colorectal adenocarcinoma cells (Caco-2), before setting in an in vitro infection model. Each GQD exhibits antibacterial activity inducing ROS and impairing bacterial metabolism without significantly affecting cell morphology. GQD activity was dependent on time of exposure to blue light. Finally, GQDs were able to reduce E. coli burden in infected Caco-2 cells, acting not only in the extracellular milieu but perturbating the eukaryotic cell membrane, enhancing antibiotic internalization. Our findings demonstrate that GQDs combined with blue light stimulation, due to photodynamic properties, have a promising antibacterial activity against E. coli. Nevertheless, we explored their action mechanism and toxicity on epithelial cells, fixing and standardizing these infection models.

Performance comparison of flip-chip blue-light microLEDs with various passivation.

In this study, arrays of µLEDs in four different sizes (5 × 5 µm2, 10 × 10 µm2, 25 × 25 µm2, 50 × 50 µm2) were fabricated using a flip-chip bonding process. Two passivation processes were investigated with one involving a single layer of SiO2 deposited using plasma-enhanced chemical vapor deposition (PECVD) and the other incorporating Al2O3 deposited by atomic layer deposition (ALD) beneath the SiO2 layer. Owing to superior coverage and protection, the double-layers passivation process resulted in a three-order lower leakage current of µLEDs in the 5 µm chip-sized µLED arrays. Furthermore, higher light output power of µLEDs was observed in each chip-sized µLED array with double layers passivation. Particularly, the highest EQE value 21.9% of µLEDs array with 5 µm × 5 µm chip size was achieved with the double-layers passivation. The EQE value of µLEDs array was improved by 4.4 times by introducing the double-layers passivation as compared with that of µLEDs array with single layer passivation. Finally, more uniform light emission patterns were observed in the µLEDs with 5 µm × 5 µm chip size fabricated by double-layer passivation process using ImageJ software.

Low blue-hazard white-light emission based on color-tunable triplet-triplet annihilation upconversion.

The commonly used artificial light sources, such as fluorescent lamps and white light-emitting diodes, often have a high ratio of blue light emission, which poses potential blue light hazards, especially one of the main culprits leading to eye diseases. Therefore, developing novel white lighting sources with low blue-hazard is highly appreciated. In this work, an air-stable and color-tunable triplet-triplet annihilation upconversion (TTA-UC) mechanism was proposed to realize the low blue-hazard white-light emission. The proposed design was composed of three primary RGB colors from the annihilator (9,10-diphenylanthracene, DPA), the laser excitation source, and the photosensitizer (palladium (II) octaetylporphyrin, PdOEP), respectively. The introduction of oil-in-water (o/w) microemulsion can effectively block the potential oxygen-induced triplet-quenching and benefit high UC efficiency. Moreover, either raising ambient temperatures or adding isobutanol can activate the UC process to yield white-light emission. Notably, the white-light emission with a Commission Internationale de l'Eclairage (CIE) coordinate of (0.33, 0.33) as well as a low ratio of blue emission (14.2 %) was achieved at an ambient temperature of 42 °C. Therefore, the proposed air-stable TTA-UC mechanism can significantly lower the blue-hazard and provide a novel solution for applications in lighting and display.

The role of the SIRT1/NF-κB/NLRP3 pathway in the pyroptosis of lens epithelial cells under shortwave blue light radiation.

Cataracts are the world's number one blinding eye disease. Cataracts can only be effectively treated surgically, although there is a chance of surgical complications. One of the pathogenic processes of cataracts is oxidative stress, which closely correlated with pyroptosis. SIRT1 is essential for the regulation of pyroptosis. Nevertheless, the role of SIRT1 in formation of cataracts is unclear. In this work, we developed an in vitro model of shortwave blue light (SWBL)-induced scotomization in human lens epithelial cells (HLECs) and an in vivo model of SWBL-induced cataracts in rats. The study aimed to understand how the SIRT1/NF-κB/NLRP3 pathway functions. Additionally, the evaluation included cell death and the release of lactate dehydrogenase (LDH), a cytotoxicity marker, from injured cells. First, we discovered that SWBL exposure resulted in lens clouding in Sprague- Dawley (SD) rats and that the degree of clouding was positively linked to the duration of irradiation. Second, we discovered that SIRT1 exhibited antioxidant properties and was connected to the NF-κB/NLRP3 pathway. SWBL irradiation inhibited SIRT1 expression, exacerbated oxidative stress, and promoted nuclear translocation of NF-κB and the activation of the NLRP3 inflammasome, which caused LEC pyroptosis and ultimately led to cataract formation. Transient transfection to increase the expression of SIRT1 decreased the protein expression levels of NF-κB, NLRP3, caspase-1, and GSDMD, inhibited HLEC pyroptosis, and reduced the release of LDH, providing a potential method for cataract prevention and treatment.

Blue light photobiomodulation induced osteosarcoma cell death by facilitating ferroptosis and eliciting an incomplete tumor cell stress response.

To investigate the potential of blue light photobiomodulation (PBM) in inducing ferroptosis, a novel form of regulated cell death, in OS cells, considering its known effectiveness in various cancer models. In this investigation, we exposed human OS cell lines, HOS and MG63, to different wavelengths (420, 460 and 480 nm) of blue light at varying irradiances, and examined cellular responses such as viability, apoptosis, levels of reactive oxygen species (ROS), and mitochondrial membrane potential (MMP). Transcriptome sequencing was employed to unravel the molecular mechanisms underlying blue light-induced effects, with validation via quantitative real-time PCR (qRT-PCR). Our findings revealed a wavelength- and time-dependent decrease in cell viability, accompanied by increased apoptosis and oxidative stress. Transcriptomic analysis identified differential expression of genes associated with ferroptosis, oxidative stress, and iron metabolism, further validated by qRT-PCR. These results implicated ferroptosis as a significant mechanism in the blue light-induced death of OS cells, potentially mediated by ROS generation and disruption of iron homeostasis. Also, An incomplete stress response was observed in MG63 cells induced by blue light exposure. Hence, blue light PBM holds promise as a therapeutic approach in OS clinical investigations; however, additional exploration of its underlying mechanisms remains imperative.

Shedding Light on Iron Nutrition: Exploring Intersections of transcription factor cascades in light and iron deficiency signaling.

In the dynamic environment of plants, the interplay between light-dependent growth and iron nutrition is a recurring challenge. Plants respond to low iron levels by adjusting growth and physiology through enhanced iron acquisition from the rhizosphere and internal iron pool reallocation. Iron deficiency response assays and gene co-expression networks aid in documenting physiological reactions and unraveling gene regulatory cascades, offering insight into the interplay between hormonal and external signaling pathways. However, research directly exploring the significance of light in iron nutrition remains limited. This review provides an overview on iron deficiency regulation and its cross-connection with distinct light signals, focusing on transcription factor cascades and long-distance signaling. The circadian clock and retrograde signaling influence iron uptake and allocation. The light-activated shoot-to-root mobile transcription factor ELONGATED HYPOCOTYL5 (HY5) affects iron homeostasis responses in roots. Blue light triggers the formation of biomolecular condensates containing iron deficiency-induced protein complexes. The potential of exploiting the connection between light and iron signaling remains underutilized. With climate change and soil alkalinity on the rise, there is a need to develop crops with improved nutrient use efficiency and modified light dependencies. More research is needed to understand and leverage the interplay between light signaling and iron nutrition.

Protective Effects of 7S,15R-Dihydroxy-16S,17S-Epoxy-Docosapentaenoic Acid (diHEP-DPA) against Blue Light-Induced Retinal Damages in A2E-Laden ARPE-19 Cells.

The purpose of this study was to investigate the protective effects of 7S,15R-dihydroxy-16S,17S-epoxy-docosapentaenoic acid (diHEP-DPA) in retinal pigment epithelial (RPE) cell damage. ARPE-19 cells, a human RPE cell line, were cultured with diHEP-DPA and Bis-retinoid N-retinyl-N-retinylidene ethanolamine (A2E), followed by exposure to BL. Cell viability and cell death rates were determined. Western blotting was performed to determine changes in apoptotic factors, mitogen-activated protein kinase (MAPK) family proteins, inflammatory proteins, and oxidative and carbonyl stresses. The levels of pro-inflammatory cytokines in the culture medium supernatants were also measured. Exposure to A2E and BL increased the ARPE-19 cell death rate, which was alleviated by diHEP-DPA in a concentration-dependent manner. A2E and BL treatments induced apoptosis in ARPE-19 cells, which was also alleviated by diHEP-DPA. Analysis of the relationship with MAPK proteins revealed that the expression of p-JNK and p-P38 increased after A2E and BL treatments and decreased with exposure to diHEP-DPA in a concentration-dependent manner. DiHEP-DPA also affected the inflammatory response by suppressing the expression of inflammatory proteins and the production of pro-inflammatory cytokines. Furthermore, it was shown that diHEP-DPA regulated the proteins related to oxidative and carbonyl stresses. Taken together, our results provide evidence that diHEP-DPA can inhibit cell damage caused by A2E and BL exposure at the cellular level by controlling various pathways involved in apoptosis and inflammatory responses.

A cellulose-based light-management film incorporated with benzoxazine resin/tannic acid exhibiting UV/blue light double blocking and enhanced mechanical property.

Cellulose, as a biomass resource, has attracted increasingly attention and extensive research by virtue of its widely sources, ideal degradability, good mechanical properties and easy modification due to its rich hydroxyl groups. Nevertheless, it is still a challenge to attain high performance cellulose-based composite film materials with diverse functional combinations. In this work, we developed a multifunctional cellulose-based film via a facile impregnation-curing strategy. Here, benzoxazine resin (BR) is used as an optically functional component to endow the microfibrillated cellulose (MFC) film with powerful light management capabilities including UV and blue light double shielding, high transmittance, and high haze. Meanwhile, the introduction of tannic acid (TA) substantially enhanced the mechanical properties of the film, including tensile strength and toughness, by constructing energy-sacrificial bonds. An effective self-healing of the film was achieved by controlling the degree of BR curing. The final films exhibited 98.24 % UV shielding and 89.98 % blue light blocking, good mechanical properties including a tensile strength of 202.21 MPa and tensile strain of 7.1 %, as well as desirable thermal healing properties supported by incompletely cured BR. This work may provide new insights into the high-value utilization of biomass resources.

The structure of Chlamydomonas LOV1 as revealed by time-resolved serial synchrotron crystallography.

The photo-reaction of the LOV1 domain of the Chlamydomonas reinhardtii phototropin is investigated by room-temperature time-resolved serial crystallography. A covalent adduct forms between the C4a atom of the central flavin-mononucleotide chromophore and a protein cysteine. The structure of the adduct is very similar to that of LOV2 determined 23 years ago from the maidenhair fern Phy3.

Induction of Endoplasmic Reticulum Stress and Aryl Hydrocarbon Receptor Pathway Expression by Blue LED Irradiation in Oral Squamous Cell Carcinoma.

Photobiomodulation therapy, as an emerging treatment modality, has been widely used in dentistry. However, reports on blue light therapy for oral cancer are scarce. This study investigated the effects of 457 and 475 nm LED irradiation on SCC-25 cells and explored the potential mechanisms underlying the impact of blue light. Both wavelengths were found to inhibit cell viability, induce oxidative stress, and cause cell cycle arrest without leading to cell death. Notably, the inhibitory effect of 457 nm blue light on cell proliferation was more sustained. Transcriptome sequencing was performed to explore the underlying mechanisms, revealing that blue light induced endoplasmic reticulum stress in SCC-25 cells, with 457 nm light showing a more pronounced effect. Moreover, 457 nm blue light upregulated the expression of the aryl hydrocarbon receptor pathway, indicating potential therapeutic prospects for the combined use of blue light and pharmacological agents.

Enhancing Blue Polymer Light-Emitting Diode Performance by Optimizing the Layer Thickness and the Insertion of a Hole-Transporting Layer.

Polymer light-emitting diodes (PLEDs) hold immense promise for energy-efficient lighting and full-color display technologies. In particular, blue PLEDs play a pivotal role in achieving color balance and reducing energy consumption. The optimization of layer thickness in these devices is critical for enhancing their efficiency. PLED layer thickness control impacts exciton recombination probability, charge transport efficiency, and optical resonance, influencing light emission properties. However, experimental variations in layer thickness are complex and costly. This study employed simulations to explore the impact of layer thickness variations on the optical and electrical properties of blue light-emitting diodes. Comparing the simulation results with experimental data achieves valuable insights for optimizing the device's performance. Our findings revealed that controlling the insertion of a layer that works as a hole-transporting and electron-blocking layer (EBL) could greatly enhance the performance of PLEDs. In addition, changing the active layer thickness could optimize device performance. The obtained results in this work contribute to the development of advanced PLED technology and organic light-emitting diodes (OLEDs).

Prospective Clinical Study: Full-Body Blue Irradiation in the Treatment of Atopic Dermatitis.

INTRODUCTION: Ultraviolet-free (UV-free) blue light phototherapy has emerged as a promising option due to its reported efficacy and minimal adverse effects. This study aims to evaluate the effectiveness of full-body blue light irradiation in both adult and pediatric patients with atopic dermatitis (AD), assessing its impact on skin condition and mood regulation by investigating serum concentrations of serotonin and kynurenine pathway metabolites. METHODS: 20 patients (age 9-45) with moderate and severe AD were included in the study. Treatment consisted of 10 irradiations with Full Body Blue device (453 nm). Serum concentrations of serotonin, quinolinic acid, kynurenic acid, tryptophan, and kynurenine were measured before and after irradiations. RESULTS: After 10 sessions of full blue light therapy (453 nm) statistically significant improvements were observed in Eczema Area Severity Index (EASI 13.16 vs. 8.65; p = 0.00016), SCORing Atopic Dermatitis (SCORAD 44.99 vs. 23.73; p < 0.00001), Visual Analogue Scale (VAS 6.53 vs. 3.95; p = 0.00251), 10-item pruritus severity scale (13.32 vs. 7.05; p < 0.00001). Moreover, statistically significant decrease in Dermatology Life Quality Index (DLQI) was noted (14.37 vs. 7.42; p = 0.00351). Additionally, increase in the serum concentration of serotonin was observed after completing 10 irradiation sessions (median 139.77 mg/ml vs. 274.92 mg/ml; p < 0.00001). CONCLUSION: Blue light may be a promising and safe treatment in patients with AD. It might also positively influence mood. Further investigations are needed to confirm those findings. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT06516783.

Betahistine mesylate reduces the damage of blue light exposure in Drosophila model.

Previous studies have demonstrated the efficacy of betahistine mesylate in treating vertigo and angioneurotic headache, enhancing microcirculation, and facilitating histamine release. However, limited research has been conducted on the drug's potential in mitigating blue light-induced damage. Thus, this study utilized Drosophila as the model organism and employed the Siler model to investigate the impact of various concentrations of betahistine mesylate on the lifespan, under 3000 lx blue light irradiation. At the same time we measure food intake, spontaneous activity, and sleep duration of Drosophila. The findings of this study indicate that a high concentration of betahistine mesylate can decrease the initial mortality (b0) in male flies, mitigating the damage of blue light to Drosophila. Consequently, this delays the aging process in male Drosophila and extends their average lifespan. After betahistine mesylate ingestion, locomotor activity upon blue light exposure decreased significantly in male Drosophila. In conclusion, this study offers initial evidence supporting the investigation of the regulatory mechanisms of betahistine mesylate on lifespan and its potential anti-blue light effects.