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Neuromorphic vision systems, particularly those stimulated by ultraviolet (UV) light, hold great potential applications in portable electronics, wearable technology, biological analysis, military surveillance, etc. Organic artificial synaptic devices hold immense potential in this field due to their ease of processing, flexibility, and biocompatibility. In this work, we have fabricated a flexible organic field-effect transistor (OFET) that utilizes chitosan-silver nanoparticles (AgNPs) composite material as the active dielectric material. During UV light illumination, both silver nanoparticles and the pentacene layer generate a large number of charge carriers. The photogenerated carriers lead to a more significant hole accumulation at the pentacene interface, resulting in a current rise. In the absence of light, the trapped electron in the silver nanoparticles persists for a longer duration, preventing the instant recombination with holes. This extended retention of electrons leads to the observed synaptic performance of the transistor. The use of aluminum oxide (Al2O3) as one of the dielectric layers enables the device to operate effectively at low voltage (<1 V). The device mimics various crucial synaptic properties of the brain, including short-term potentiation and long-term potentiation (STP and LTP), paired-pulse facilitation (PPF), spike-duration dependent plasticity (SDDP), spike-number dependent plasticity (SNDP), and spike-rate dependent plasticity (SRDP), etc. This work introduces an approach to develop flexible organic synaptic transistors that operate efficiently at low voltages, paving the way toward high-performance, UV light-driven neuromorphic vision systems.
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Aluminum (Al) may be beneficial to crops, but in excess becomes detrimental to the germination and initial development of seedlings. The main determining indicators are the type of crop and exposure duration. The aim of this study was to examine the influence of Al and of UV-C light on the germination and initial growth of white oats. Seeds were sown on germitest paper in a solution of 100, 200, 300, 400, or 500 mg/L of aluminum chloride and kept in a germination chamber at 20°C for a 12-hr photoperiod. Germination and seedling growth parameters were determined after 5 and 10 days. The seeds were also exposed to two doses of UV-C (0.85 and 3.42 kJ m-2) under aluminum chloride stress (200 mg/L). Data demonstrated that treatment with aluminum chloride significantly decrease in germination at 200 mg/L and total seedling length at 100 mg/L. Exposure of seeds to UV-C light under excess Al (200 mg/L) did not show a significant effect on germination and growth compared to control (non-irradiated). Results indicated that exposure to high concentration of Al in the medium adversely altered germination and initial growth of white oat seedlings. Although UV-C light alone was not detrimental to the germination process, treatment with UV-C light also failed to mitigate the toxic effects of Al.
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Persistent luminescent nanoparticles (PLNPs) are promising for many bioapplications due to their unique afterglow luminescence following the stoppage of light excitation. However, PLNPs are prone to surface quenching that results in weak afterglow luminescence. Although some efforts have been made to reduce surface quenching through designing homogeneous core-shell PLNPs, the enhancement in afterglow luminescence was insignificant. We hypothesize that the independent absorption and emission of the shell caused less energy to reach the activator ions in the core. Hence, a heterogeneous core-shell PLNP where the shell has a higher band gap than the core would reduce the absorption and emission of the shell. In this work, ZnGa2O4 and Zn2GeO4 were coated on Zn1.2Ga1.6Ge0.2O4:Cr and Zn3Ga2Ge2O10:Eu nanocrystals, respectively, to form heterogeneous core-shell PLNPs and significant luminescence enhancement was achieved compared to their traditional homogeneous core-shell nanostructures.
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Indoor farming systems enable plant production in precisely controlled environments. However, implementing stable growth conditions and the absence of stress stimulants can weaken plants' defense responses and limit the accumulation of bioactive, health-beneficial phytochemicals. A potential solution is the controlled application of stressors, such as supplemental ultraviolet (UV) light. To this end, we analyzed the efficiency of short-term pre-harvest supplementation of the red-green-blue (RGB, LED) spectrum with ultraviolet B (UV-B) or C (UV-C) light to boost phytochemical synthesis. Additionally, given the biological harm of UV radiation due to high-energy photons, we monitored plants' photosynthetic activity during treatment and their morphology as well as sensory attributes after the treatment. Our analyses showed that UV-B radiation did not negatively impact photosynthetic activity while significantly increasing the overall antioxidant potential of lettuce through enhanced levels of secondary metabolites (total phenolics, flavonoids, anthocyanins), carotenoids, and ascorbic acid. On the contrary, UV-C radiation-induced anthocyanin accumulation in the green leaf cultivar significantly harmed the photosynthetic apparatus and limited plant growth. Taken together, we showed that short-term UV-B light supplementation is an efficient method for lettuce biofortification with healthy phytochemicals, while UV-C treatment is not recommended due to the negative impact on the quality (morphology, sensory properties) of the obtained leafy products. These results are crucial for understanding the potential of UV light supplementation for producing functional plants.
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Antioxidantes , Lactuca , Fotosíntesis , Rayos Ultravioleta , Lactuca/metabolismo , Lactuca/efectos de la radiación , Lactuca/efectos de los fármacos , Lactuca/crecimiento & desarrollo , Fotosíntesis/efectos de los fármacos , Fotosíntesis/efectos de la radiación , Antioxidantes/metabolismo , Hojas de la Planta/metabolismo , Hojas de la Planta/efectos de la radiación , Hojas de la Planta/efectos de los fármacos , Flavonoides/metabolismo , Fitoquímicos/metabolismo , Carotenoides/metabolismo , Antocianinas/metabolismo , Ácido Ascórbico/metabolismo , Fenoles/metabolismoRESUMEN
Though the exact causes of systemic lupus erythematosus (SLE) remain unknown, exposure to ultraviolet (UV) light is one of the few well-known triggers of cutaneous inflammation in SLE. However, the precise cell types which contribute to the early cutaneous inflammatory response in lupus, and the ways that UV dosing and interferons modulate these findings, have not been thoroughly dissected. Here, we explore these questions using the NZM2328 spontaneous murine model of lupus. In addition, we use iNZM mice, which share the NZM2328 background but harbor a whole-body knockout of the type I interferon (IFN) receptor, and wild-type BALB/c mice. 10-13-week-old female mice of each strain were treated with acute (300 mJ/cm2 x1), chronic (100 mJ/cm2 daily x5 days), or no UVB, and skin was harvested and processed for bulk RNA sequencing and flow cytometry. We identify that inflammatory pathways and gene signatures related to myeloid cells - namely neutrophils and monocyte-derived dendritic cells - are a shared feature of the acute and chronic UVB response in NZM skin greater than iNZM and wild-type skin. We also verify recruitment and activation of these cells by flow cytometry in both acutely and chronically irradiated NZM and WT mice and demonstrate that these processes are dependent on type I IFN signaling. Taken together, these data indicate a skewed IFN-driven inflammatory response to both acute and chronic UVB exposure in lupus-prone skin dominated by myeloid cells, suggesting both the importance of type I IFNs and myeloid cells as therapeutic targets for photosensitive patients and highlighting the risks of even moderate UV exposure in this patient population.
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Megalurothrips usitatus Bagnall, an important pest of bean plants, is primarily managed with synthetic insecticides. M. usitatus has developed considerable resistance to various insecticides in multiple cowpea-growing areas in Hainan Province, China, posing challenges to its control in the field. Light control technology is a potentially effective physical control method for M. usitatus. The vision of thrips is highly sensitive to UV light, whereas other biological characteristics remain unknown. Therefore, this study evaluated the effects of ultraviolet light on the biological characteristics of M. usitatus. Results showed that the egg, larval, and pupal stages of M. usitatus were significantly shortened, and the emergence rate (79.59%) and adult survival rate (77.95%) were reduced under a devoid of UV light environment (UV-), compared with the full-spectrum light (control treatment group, CK) (p < 0.05). However, the single spawning quantity and total amount of spawning were significantly higher, and the sex ratio (57%) was the highest under UV- (p < 0.05). Single UV light (UV+) only affected the pupation rate. Also, the antioxidant enzymes, polyphenol oxidase, superoxide dismutase (SOD), and peroxidase activities were significantly and negatively correlated with the progression of generations under UV-, whereas catalase and SOD activities were significantly and positively correlated with the progression of generations under UV+. The UV- light conditions significantly interfered with the behavior selection of M. usitatus. The results of this study showed that the adaptability of M. usitatus populations would be greatly reduced in the absence of ultraviolet light, providing a theoretical basis for the control of M. usitatus populations.
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Thysanoptera , Rayos Ultravioleta , Animales , Thysanoptera/fisiología , Larva/crecimiento & desarrollo , Larva/efectos de la radiación , Femenino , Pupa/efectos de la radiación , Pupa/crecimiento & desarrollo , Masculino , Adaptación FisiológicaRESUMEN
The problem of antimicrobial resistance (AMR) is not limited to the medical field but is also becoming prevalent on a global scale in the environmental field. Environmental water pollution caused by the discharge of wastewater into aquatic environments has caused concern in the context of the sustainable development of modern society. However, there have been few studies focused on the treatment of hospital wastewater, and the potential consequences of this remain unknown. This study evaluated the efficacy of the inactivation of antimicrobial-resistant bacteria (AMRB) and antimicrobial resistance genes (AMRGs) in model wastewater treatment plant (WWTP) wastewater and hospital effluent based on direct ultraviolet (UV) light irradiation provided by a conventional mercury lamp with a peak wavelength of 254 nm and an ultraviolet light-emitting diode (UV-LED) with a peak emission of 280 nm under test conditions in which the irradiance of both was adjusted to the same intensity. The overall results indicated that both UV- and UV-LED-mediated disinfection effectively inactivated the AMRB in both wastewater types (>99.9% after 1-3 min of UV and 3 min of UV-LED treatment). Additionally, AMRGs were also removed (0.2-1.4 log10 for UV 254 nm and 0.1-1.3 log10 for UV 280 nm), and notably, there was no statistically significant decrease (p < 0.05) in the AMRGs between the UV and UV-LED treatments. The results of this study highlight the importance of utilizing a local inactivation treatment directly for wastewater generated by a hospital prior to its flow into a WWTP as sewage. Although additional disinfection treatment at the WWTP is likely necessary to remove the entire quantity of AMRB and AMRGs, the present study contributes to a significant reduction in the loads of WWTP and urgent prevention of the spread of infectious diseases, thus alleviating the potential threat to the environment and human health risks associated with AMR problems.
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Germicidal UV light (UV-C) has been shown to effectively suppress several plant pathogens as well as some arthropod pests. Recent reports describe the efficacy of nighttime applications of UV-C at doses from 100 to 200 J/m2 in vineyards to reduce grape powdery mildew (Erysiphe necator). Our in vitro studies confirmed the efficacy of UV-C to inhibit germination of E. necator and Botrytis cinerea conidia, demonstrated a range of tolerances to UV-C within a collection of E. necator isolates, and showed growth stage-specific effects of UV-C on B. cinerea. Nighttime use of UV-C was evaluated at 48 to 96 J/m2 in small plot trials (<1,000 vines) from 2020 to 2023. Once- or twice-weekly UV-C applications significantly reduced the incidence of foliar powdery mildew compared with non-UV-C-treated controls (P < 0.02). Suppression of powdery mildew on fruit was less consistent, where once or twice weekly UV-C exposure reduced powdery mildew disease severity in 2020 (P = 0.04), 2021 (P = 0.02), and 2023 (P = 0.003) but less so in 2022 (P = 0.07). Bunch rot severity was not significantly reduced with UV-C treatment in any year of the study. Application of UV-C until the onset of fruit color change (veraison) also had a minimal effect on the fruit-soluble solids, pH, anthocyanins, or phenolics in harvested fruit at any UV-C dose or frequency (P > 0.10). Suppression of powdery mildew by nighttime application of UV-C at lower doses in small plots suggests that such treatments merit further evaluation in larger-scale studies in Western Oregon.
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In this study, we propose a polarized electron blocking layer (EBL) structure using AlxGa1-xN/AlxGa1-xN to enhance the internal quantum efficiency (IQE) of AlGaN-based ultraviolet light-emitting diodes (UV LEDs). Our findings indicate that this polarized EBL structure significantly improves IQE compared to conventional EBLs. Additionally, we introduce an electric-field reservoir (EFR) optimization method to maximize IQE. Specifically, optimizing the polarized EBL structure of AlxGa1-xN/AlxGa1-xN enhances the hole drift rate, resulting in an IQE improvement of 19% and an optical output power increase of 186 mW at a current of 210 mA.
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Meat is highly susceptible to contamination with harmful microorganisms throughout the production, processing, and storage chain, posing a significant public health risk. Traditional decontamination methods like chemical sanitizers and heat treatments often compromise meat quality, generate harmful residues, and require high energy inputs. This necessitates the exploration of alternative non-ionizing technologies for ensuring meat safety and quality. This review provides a comprehensive analysis of the latest advancements, limitations, and future prospects of non-ionizing technologies for meat decontamination, with a specific focus on ultrasonication. It further investigates the comparative advantages and disadvantages of ultrasonication against other prominent non-ionizing technologies such as microwaves, ultraviolet (UV) light, and pulsed light. Additionally, it explores the potential of integrating these technologies within a multi-hurdle strategy to achieve enhanced decontamination across the meat surface and within the matrix. While non-ionizing technologies have demonstrated promising results in reducing microbial populations while preserving meat quality attributes, challenges remain. These include optimizing processing parameters, addressing regulatory considerations, and ensuring cost-effectiveness for large-scale adoption. Combining these technologies with other methods like antimicrobial agents, packaging, and hurdle technology holds promise for further enhancing pathogen elimination while safeguarding meat quality.
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Descontaminación , Carne , Carne/microbiología , Descontaminación/métodos , Sonicación/métodos , Ondas UltrasónicasRESUMEN
Enzymatic browning in fruits and vegetables, driven by polyphenol oxidase (PPO) activity, results in color changes and loss of bioactive compounds. Emerging technologies are being explored to prevent this browning and ensure microbial safety in foods. This study assessed the effectiveness of pulsed light (PL) and ultraviolet light-emitting diodes (UV-LED) in inhibiting PPO and inactivating Escherichia coli ATTC 25922 in fresh apple juice (Malus domestica var. Red Delicious). Both treatments' effects on juice quality, including bioactive compounds, color changes, and microbial inactivation, were examined. At similar doses, PL-treated samples (126 J/cm2) showed higher 2,2- diphenyl-1-picrylhydrazyl inhibition (9.5%) compared to UV-LED-treated samples (132 J/cm2), which showed 1.06%. For microbial inactivation, UV-LED achieved greater E. coli reduction (>3 log cycles) and less ascorbic acid degradation (9.4% ± 0.05) than PL. However, increasing PL doses to 176 J/cm2 resulted in more than 5 log cycles reduction of E. coli, showing a synergistic effect with the final temperature reached (55 °C). The Weibull model analyzed survival curves to evaluate inactivation kinetics. UV-LED was superior in preserving thermosensitive compounds, while PL excelled in deactivating more PPO and achieving maximal microbial inactivation more quickly.
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Catecol Oxidasa , Escherichia coli , Jugos de Frutas y Vegetales , Malus , Viabilidad Microbiana , Rayos Ultravioleta , Catecol Oxidasa/metabolismo , Malus/química , Escherichia coli/efectos de la radiación , Jugos de Frutas y Vegetales/análisis , Jugos de Frutas y Vegetales/microbiología , Viabilidad Microbiana/efectos de la radiación , Irradiación de Alimentos/métodosRESUMEN
Cutaneous field cancerization (CFC) refers to a skin region containing mutated cells' clones, predominantly arising from chronic exposure to ultraviolet radiation (UVR), which exhibits an elevated risk of developing precancerous and neoplastic lesions. Despite extensive research, many molecular aspects of CFC still need to be better understood. In this study, we conducted ex vivo assessment of cell differentiation, oxidative stress, inflammation, and DNA damage in CFC samples. We collected perilesional skin from 41 patients with skin cancer and non-photoexposed skin from 25 healthy control individuals. These biopsies were either paraffin-embedded for indirect immunofluorescence and immunohistochemistry stain or processed for proteins and mRNA extraction from the epidermidis. Our findings indicate a downregulation of p53 expression and an upregulation of Ki67 and p16 in CFC tissues. Additionally, there were alterations in keratinocyte differentiation markers, disrupted cell differentiation, increased expression of iNOS and proinflammatory cytokines IL-6 and IL-8, along with evidence of oxidative DNA damage. Collectively, our results suggest that despite its outwardly normal appearance, CFC tissue shows early signs of DNA damage, an active inflammatory state, oxidative stress, abnormal cell proliferation and differentiation.
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Diferenciación Celular , Daño del ADN , Inflamación , Estrés Oxidativo , Neoplasias Cutáneas , Rayos Ultravioleta , Humanos , Neoplasias Cutáneas/metabolismo , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/genética , Inflamación/metabolismo , Inflamación/genética , Inflamación/patología , Masculino , Femenino , Persona de Mediana Edad , Rayos Ultravioleta/efectos adversos , Anciano , Queratinocitos/metabolismo , Queratinocitos/patología , Óxido Nítrico Sintasa de Tipo II/metabolismo , Óxido Nítrico Sintasa de Tipo II/genética , Adulto , Proteína p53 Supresora de Tumor/metabolismo , Proteína p53 Supresora de Tumor/genética , Piel/metabolismo , Piel/patología , Piel/efectos de la radiación , Antígeno Ki-67/metabolismo , Antígeno Ki-67/genética , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Interleucina-6/metabolismo , Interleucina-6/genéticaRESUMEN
OBJECTIVE: To analyze the effects and tolerability of physiotherapeutic methods with optical radiation (phototherapy) in acute respiratory diseases (ARD) on the basis of the modern scientific literature data and the results of doctors and patients survey. MATERIAL AND METHODS: An analysis of regulatory sources and modern scientific literature on the subject of research, survey of 200 patients with ARD and 100 primary care physicians of the Central Federal District on their sociomedical status and awareness of phototherapeutic treatment methods were conducted. RESULTS: Phototherapy in ARD have demonstrated chromogenic, immunostimulating, photosensitizing, vitamin-forming, trophostimulating, anti-inflammatory, analgesic, desensitizing, bactericidal and mycocidal, metabolic, coagulo-correcting therapeutic effects. Patients and doctors have been insufficiently aware of phototherapy methods and used them in practice relatively rare. A significant proportion of patients had ARD risk factors, namely teamwork, tobacco smoking and chronic diseases. CONCLUSION: 1. The therapeutic effects of all types of phototherapy in acute respiratory infections are interrelated with their etiopathogenesis. 2. Patients and doctors are insufficiently informed and relatively rarely use phototherapy methods. 3. A significant proportion of patients have risk factors for acute respiratory infections: teamwork (88%), tobacco smoking (68%) and chronic diseases (52%).
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Fototerapia , Humanos , Fototerapia/métodos , Enfermedad Aguda , Masculino , Femenino , Adulto , Enfermedades Respiratorias/terapia , Infecciones del Sistema Respiratorio/terapia , Persona de Mediana EdadRESUMEN
Ultraviolet (UV) light is the most pervasive environmental mutagen and the primary cause of skin cancer. Genome sequencing of melanomas and other skin cancers has revealed that the vast majority of somatic mutations in these tumors are cytosine-to-thymine (C>T) substitutions in dipyrimidine sequences, which, together with tandem CC>TT substitutions, comprise the canonical UV mutation "signature". These mutation classes are caused by DNA damage directly induced by UV absorption, namely cyclobutane pyrimidine dimers (CPDs) or 6-4 pyrimidine-pyrimidone photoproducts (6-4PP), which form between neighboring pyrimidine bases. However, many of the key driver mutations in melanoma do not fit this mutation signature, but instead are caused by T>A, T>C, C>A, or AC>TT substitutions, frequently occurring in non-dipyrimidine sequence contexts. This article describes recent studies indicating that UV light causes a more diverse spectrum of mutations than previously appreciated, including many of the mutation classes observed in melanoma driver mutations. Potential mechanisms for these diverse mutation signatures are discussed, including UV-induced pyrimidine-purine photoproducts and indirect DNA damage induced by UVA light. Finally, the article reviews recent findings indicating that human DNA polymerase eta normally suppresses these non-canonical UV mutation classes, which can potentially explain why canonical C>T substitutions predominate in human skin cancers.
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INTRODUCTION: Healthcare-associated infections (HCAIs) in neonates are frequent and highly lethal, in particular those caused by extended spectrum beta-lactamase (ESBL) producing bacteria. We evaluated the beneficial effects of ultraviolet C (UV-C) disinfection and copper adhesive plating on HCAIs in the Neonatal Intensive Care Unit (NICU) of a third level paediatric hospital in Mexico City, both in combination of hand-hygiene (HH) and prevention bundles. METHODS: All NICU patients were included. There were 4 periods (P): P1: HH monitoring and prevention bundles; P2: P1+UV-C disinfection; P3: P2+Copper adhesive plating on frequent-contact surfaces and P4: Monitoring of P3 actions. RESULTS: 552 neonates were monitored during 15,467 patient days (PD). HCAI rates decreased from 11.03/1000 PD in P1 to 5.35/1000 PD in P4 (p=0.006). HCAIs with bacterial isolates dropped from 5.39/1000 PD in PI to 1.79/1000 PD in P4 (p=0.011). UV-C and copper were associated with significant HCAI prevention (RR 0.49, CI95% 0.30-0.81, p=0.005) and with lesser HCAIs with bacterial isolates (RR 0.33, CI95% 0.14-0.77, p=0.011). CONCLUSIONS: Copper adhesive plating combined with UV-C disinfection were associated with a drop in HCAI rates and with the elimination of ESBL-caused HCAIs. Hence, we propose that these strategies be considered in MDRO proliferation preventions.
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As our knowledge of the harmful effects of ultraviolet radiation continues to evolve, sunscreen remains an integral part of a comprehensive photoprotection strategy against multiple endpoints of ultraviolet-mediated damage. Part 1 of this review covers sunscreen active and additive ingredient properties, mechanisms of action and gaps in coverage. Following an overview of sunscreen's efficacy in protecting against sunburn, photocarcinogenesis, photoaging, pigmentary disorders, and idiopathic photodermatoses, we highlight considerations for product use and selection in children and individuals with skin of color.
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Background: Measurement of light intensity reaching a point of interest in complex systems is a challenge faced by academia and industry. This study analyzes an optical ray tracing method to predict the radiant intensity reaching a point of interest in a germicidal system. Methods: Implementation was performed by analyzing how the method compares with the discrete ordinate method, radiometry, and actinometry. This study further quantified the effect of the photoreactor quartz tube on the measured intensity for multiple wavelengths. Results: Light intensity losses were estimated to be 10 ± 0.5% for the FX-1 265 source. In contrast, the simulation in a water medium showed an increase of up to 64% in the light intensity delivered to the central part of the tube owing to internal reflections and scattering. Model predictions from ray tracing were successfully compared with the discrete ordinate method (DOM) and experimental data (within ± 6%), ensuring the accurate design of complex systems for water disinfection. Conclusions: The data from simulations address the challenges faced in complex radiation modeling and demonstrate that the method can be utilized as a useful tool for optimization and prediction.
The following study explores a new way to measure the strength of light in complex systems, particularly in water treatment type setups. We used a method called optical ray tracing to predict how much light reaches a specific point in the system and have compared it with other techniques like radiometry and discrete ordinate method to make sure it is valid and accurate. An interesting finding was that the type of tube material, in this case, a quartz tube, affects the intensity of the light. For a specific light source with 265 nm light emitting diodes, we estimate a 10% reduction in light intensity due to the quartz tube (transporter of water through the system) in air. But when the simulation was done in a water medium, we found a 64% increase in light intensity in the center of the tube because of how light bounces around and scatters in water. The optical ray tracing method's predictions closely matched other techniques (within about 6% of error), making it a useful tool for designing systems for water disinfection. The study also builds a complex system and predicts the amount of light reaching certain points of interest. This research helps tackle challenges in modeling complex radiation systems and offers insights into how to optimize and predict the behavior of light in such systems.
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PURPOSE: The formation of a biological seal between implant abutments and the surrounding soft tissue is a preventive strategy against peri-implantitis. The aim of this study is to test the hypothesis that surfaces of prosthetic implant abutments treated with vacuum ultraviolet (VUV) light enhance the growth and function of human gingival fibroblasts. MATERIALS AND METHODS: Implant abutments were treated with 172 nm VUV light for one minute. Untreated abutments were subjected as controls. Their surface properties were characterized using SEM, contact angle measurements, and chemical composition analysis. Human gingival fibroblasts were cultured on both untreated and VUV-treated abutments to evaluate cell attachment, proliferation, distribution, and collagen production. Cell detachment assays were also performed under various mechanical and chemical stimuli. RESULTS: After VUV treatment, implant abutments demonstrated a notable transition from hydrophobic to hydrophilic wettability. Surface element analysis revealed a considerable reduction in surface carbon and increases in oxygen and titanium elements on the VUV-treated surfaces. On day 1 of culture, 3.9 times more fibroblasts attached on VUV-treated abutments than on untreated control abutments. Fibroblastic proliferation increased 1.9-3.1 times on VUV-treated abutments, along with a significant improvement in the distribution of populating cells. Collagen production on VUV-treated abutments increased by 1.5-1.7 times. While untreated abutment surfaces showed voids and limited spread of collagen deposition, dense and full coverage of collagen was observed on VUV-treated abutments, with a great contrast in the challenging axial surface zone. Cell retention against mechanical and chemical detaching stimuli was increased 11.3 and 4.3 times, respectively, by VUV treatment. CONCLUSION: Treatment of implant abutments with VUV light for one minute resulted in a reduction of surface carbon and a transformation of the surface from hydrophobic to hydrophilic. This led to enhanced attachment, proliferation, and retention of human gingival fibroblasts, along with nearly complete collagen coverage on implant abutments. These in vitro results indicate the promising potential of utilizing VUV photofunctionalized implant abutments to enhance soft tissue reaction and sealing mechanisms.
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Mammalian melanin is produced in melanocytes and accumulated in melanosomes. Melanogenesis is supported by many factors derived from the surrounding tissue environment, such as the epidermis, dermis, and subcutaneous tissue, in addition to numerous melanogenesis-related genes. The roles of these genes have been fully investigated and the molecular analysis has been performed. Moreover, the role of paracrine factors derived from epidermis has also been studied. However, the role of dermis has not been fully studied. Thus, in this review, dermis-derived factors including soluble and insoluble components were overviewed and discussed in normal and abnormal circumstances. Dermal factors play an important role in the regulation of melanogenesis in the normal and abnormal mammalian skin.
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Melaninas , Melanocitos , Melaninas/metabolismo , Melanocitos/metabolismo , Humanos , Animales , Piel/metabolismo , Dermis/metabolismo , Epidermis/metabolismo , MelanogénesisRESUMEN
The use of Meliponini for crop pollination in protected environments is practically non-existent. One of the reasons is the difficulty of acclimatizing Meliponini to the temperature and light conditions inside greenhouses. We investigated how covering materials used in greenhouses, which filter different intensities of ultraviolet (UV) light, affect the foraging behaviors, flight orientation, attraction to walls and ceilings, and mortality of Scaptotrigona cf. postica (Letreille), Frieseomelitta varia (Lepeletier), and Melipona quadrifasciata (Lepeletier). The experiments were conducted in 5.3 m3 arenas covered with four types of plastic films that do not polarize sunlight, with UV transmittance levels ranging from 0.1 to 54%, compared to a transparent glass control. The temperature inside the arenas varied between treatments, from 27 ± 3°C to 31 ± 2°C. All three species collected resources and returned to the colony, regardless of the covering material. However, the proportion of this behavior, the number of bees attracted to the ceiling and wall, and mortality varied among treatments and/or throughout the confinement days for each species. Melipona quadrifasciata and F. varia acclimatized better to the confined environments than S. cf. postica and showed consistent resource collection behavior throughout the confinement days in all tested materials, except for the one that filtered around 90% of UV. In all three species, the mortality gradually decreased throughout the confinement days. The results indicate that the choice of covering material, considering its optical characteristics, can be crucial to ensure greater effectiveness of the pollination services provided by stingless bees in protected systems.