RESUMO
In recent years, the biodegradable plastics has extensively used in industry, agriculture, and daily life. Herein, the effects of two biodegradable microplastics (BMPs), poly(butyleneadipate-co-terephthalate) (PBAT) and polyhydroxyalkanoate (PHA), on soil sulfamethoxazole (SMX) degradation and sul genes development were comparatively studied based on the type, dosage, and state. The addition of virgin BMPs significantly increased soil DOC following a sequential order PBAT > PHA and high dose > low dose. Meanwhile virgin PBAT significantly reduced soil pH. In general, the addition of BMPs not only promoted soil SMX degradation but also increased the abundance of sul genes, with an exception that pH reduction in virgin PBAT inhibited the proliferation of sul genes. The driving effects of BMPs on soil microbial diversity following the same order as that on DOC. Specific bacteria stimulated by BMPs, such as Arthrobacter and two genera affiliated with phylum TM7, accounted for the accelerated degradation of SMX. Intriguingly, UV-aging hindered the release of DOC from BMPs and the reduction in pH, mitigated the stimulation of microbial communities, and ultimately reduced the promotion effect of BMPs on SMX degradation and sul genes proliferation. Our results suggest that more attention should be paid to the proliferation risk of ARGs in the environment affected by BMPs and UV-aging can be employed sometimes to reduce this risk.
Assuntos
Biodegradação Ambiental , Microbiologia do Solo , Poluentes do Solo , Solo , Sulfametoxazol , Sulfametoxazol/toxicidade , Solo/química , Microplásticos/toxicidade , Raios Ultravioleta , Plásticos BiodegradáveisRESUMO
During the water treatment process, chlorination and ultraviolet (UV) sterilization can modify microplastics (MPs) and alter their physicochemical properties, causing various changes between MPs and other pollutants. In this study, the impact of chlorination and UV modification on the physicochemical properties of polystyrene (PS) and polyvinyl chloride (PVC) were investigated, and the adsorption behavior of pefloxacin (PEF) before and after modification was examined. The effect of pH, ionic strength, dissolved organic matter, heavy metal ions and other water environmental conditions on adsorption behavior was revealed. The results showed that PS had a higher adsorption capacity of PEF than PVC, and the modification increased the presence of O-containing functional groups in the MPs, thereby enhancing the adsorption capacity of both materials. Chlorination had a more significant impact on the physicochemical properties of MPs compared to UV irradiation within the same time period, leading to better adsorption performance of chlorination. The optimal pH for adsorption was found to be 6, and NaCl, sodium alginate and Cu2+ would inhibit adsorption to varying degrees, among which the inhibition caused by pH was the strongest. Chlorination and UV modification would weaken the inhibitory effect of environmental factors on the adsorption of PEF by MPs. The main mechanisms of adsorption involved electrostatic interaction and hydrogen bonding. The study clarified the effects of modification on the physicochemical properties of MPs, providing reference for subsequent biotoxicity analysis and environmental protection studies.
Assuntos
Halogenação , Pefloxacina , Poliestirenos , Cloreto de Polivinila , Raios Ultravioleta , Poluentes Químicos da Água , Purificação da Água , Adsorção , Cloreto de Polivinila/química , Poluentes Químicos da Água/química , Poliestirenos/química , Purificação da Água/métodos , Pefloxacina/química , Concentração de Íons de HidrogênioRESUMO
Formic and acetic acids are the most abundant gaseous organic acids and play the key role in the atmospheric chemistry. In iodine-adduct chemical ionization mass spectrometry (CIMS), the low utilization efficiency of methyl iodide and humidity interference are two major issues of the vacuum ultraviolet (VUV) lamp initiated CIMS for on-line gaseous formic and acetic acids analysis. In this work, we present a new CIMS based on VUV lamp, and the ion-molecular reactor is separated into photoionization and chemical ionization zones by a reducer electrode. Acetone was added to the photoionization zone, and the VUV photoionization acetone provided low-energy electrons for methyl iodide to generate I-, and the addition of acetone reduced the amount of methyl iodide by 2/3. In the chemical ionization zone, a headspace vial containing ultrapure water was added for humidity calibration, and the vial changes the sensitivity as a function of humidity from ambiguity to well linear correlation (R2 > 0.95). With humidity calibration, the CIMS can quantitatively measure formic and acetic acids in the humidity range of 0%-88% RH. In this mode, limits of detection of 10 and 50 pptv are obtained for formic and acetic acids, respectively. And the relative standard deviation (RSD) of quantitation stability for 6 days were less than 10.5%. This CIMS was successfully used to determine the formic and acetic acids in the underground parking and ambient environment of the Shandong University campus (Qingdao, China). In addition, we developed a simple model based formic acid concentration to assess vehicular emissions.
Assuntos
Espectrometria de Massas , Espectrometria de Massas/métodos , Poluentes Atmosféricos/análise , Iodetos/análise , Iodetos/química , Raios Ultravioleta , Formiatos/análise , Formiatos/química , Atmosfera/química , Monitoramento Ambiental/métodos , Processos Fotoquímicos , Ácido Acético/análise , Ácido Acético/química , Hidrocarbonetos Iodados/análise , Hidrocarbonetos Iodados/químicaRESUMO
A mixed oxidant of chlorine dioxide (ClO2) and NaClO was often used in water treatment. A novel UVA-LED (365 nm)-activated mixed ClO2/NaClO process was proposed for the degradation of micropollutants in this study. Carbamazepine (CBZ) was selected as the target pollutant. Compared with the UVA365/ClO2 process, the UVA365/ClO2/NaClO process can improve the degradation of CBZ, with the rate constant increasing from 2.11×10-4 sec-1 to 2.74×10-4 sec-1. In addition, the consumption of oxidants in the UVA365/ClO2/NaClO process (73.67%) can also be lower than that of UVA365/NaClO (86.42%). When the NaClO ratio increased, both the degradation efficiency of CBZ and the consumption of oxidants can increase in the UVA365/ClO2/NaClO process. The solution pH can affect the contribution of NaClO in the total oxidant ratio. When the pH range of 6.0-8.0, the combination process can generate more active species to promote the degradation of CBZ. The change of active species with oxidant molar ratio was investigated in the UVA365/ClO2/NaClO process. When ClO2 acted as the main oxidant, HO⢠and Cl⢠were the main active species, while when NaClO was the main oxidant, ClO⢠played a role in the system. Both chloride ion (Cl-), bicarbonate ion (HCO3-), and nitrate ion (NO3-) can promote the reaction system. As the concentration of NaClO in the reaction solution increased, the generation of chlorates will decrease. The UVA365/ClO2/NaClO process can effectively control the formation of volatile disinfection by-products (DBPs), and with the increase of ClO2 dosage, the formation of DBPs can also decrease.
Assuntos
Carbamazepina , Compostos Clorados , Óxidos , Raios Ultravioleta , Poluentes Químicos da Água , Purificação da Água , Carbamazepina/química , Poluentes Químicos da Água/química , Compostos Clorados/química , Purificação da Água/métodos , Óxidos/química , Cinética , Hipoclorito de Sódio/química , Modelos QuímicosRESUMO
Because of the recent widespread usage of antibiotics, the acquisition and dissemination of antibiotic-resistance genes (ARGs) were prevalent in the majority of habitats. Generally, the biological wastewater treatment processes used in wastewater treatment plants have a limited efficiencies of antibiotics resistant bacteria (ARB) disinfection and ARGs degradation and even promote the proliferation of ARGs. Problematically, ARB and ARGs in effluent pose potential risks if they are not further treated. Photocatalytic oxidation is considered a promising disinfection technology, where the photocatalytic process generates many free radicals that enhance the interaction between light and deoxyribonucleic acid (DNA) for ARB elimination and subsequent degradation of ARGs. This review aims to illustrate the progress of photocatalytic oxidation technology for removing antibiotics resistant (AR) from wastewater in recent years. We discuss the sources and transfer of ARGs in wastewater. The overall removal efficiencies of ultraviolet radiation (UV)/chlorination, UV/ozone, UV/H2O2, and UV/sulfate-radical based system for ARB and ARGs, as well as the experimental parameters and removal mechanisms, are systematically discussed. The contribution of photocatalytic materials based on TiO2 and g-C3N4 to the inactivation of ARB and degradation of ARGs is highlighted, producing many free radicals to attack ARB and ARGs while effectively limiting the horizontal gene transfer (HGT) in wastewater. Finally, based on the reviewed studies, future research directions are proposed to realize specific photocatalytic oxidation technology applications and overcome current challenges.
Assuntos
Eliminação de Resíduos Líquidos , Águas Residuárias , Águas Residuárias/química , Eliminação de Resíduos Líquidos/métodos , Bactérias , Desinfecção/métodos , Farmacorresistência Bacteriana/genética , Raios Ultravioleta , Purificação da Água/métodosRESUMO
BACKGROUND AND RATIONALE: Ultraviolet-B (UVB) light induces dermal inflammation, although it is mostly absorbed in the epidermis. Recent reports suggest extracellular vesicles (EVs) act as a mediator of photodamage signaling. Melatonin is reported to be a protective factor against UV-induced damage. We hypothesized that EVs derived from UVB-irradiated keratinocytes might trigger proinflammatory responses in dermal cells and tested whether melatonin can ameliorate UVB-induced inflammation. METHODS: We used UVB-irradiated HaCaT cells, primary keratinocytes and STING knock-out mice to model production of EVs under photodamaging conditions and performed immunoblotting and ELISA to measure their effect on dermal macrophages. RESULTS: UVB-irradiated keratinocytes produce an increased number of EVs that contain higher concentrations of DNA and protein compared with controls. KC-derived EVs (KEVs) induced a STING- and inflammasome-mediated proinflammatory response in macrophages in vitro, and a pronounced inflammatory infiltrate in mouse dermis in vivo. Melatonin ameliorated KEVs inflammatory effect both in vitro and in vivo. CONCLUSIONS: This data suggests EVs are mediators in a crosstalk that takes place between keratinocytes and their neighboring cells as a result of photodamage. Further studies exploring EVs induced by damaging doses of UVB, and their impact on other cells will provide insight into photodamage and may help develop targeted therapeutic approaches.
Assuntos
Derme , Epiderme , Vesículas Extracelulares , Queratinócitos , Raios Ultravioleta , Vesículas Extracelulares/metabolismo , Queratinócitos/metabolismo , Queratinócitos/efeitos da radiação , Animais , Humanos , Epiderme/efeitos da radiação , Epiderme/metabolismo , Epiderme/patologia , Camundongos , Derme/patologia , Derme/metabolismo , Inflamação/metabolismo , Inflamação/patologia , Melatonina/farmacologia , Melatonina/metabolismo , Macrófagos/metabolismo , Macrófagos/efeitos da radiação , Camundongos Knockout , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Camundongos Endogâmicos C57BL , Células HaCaTRESUMO
Since the COVID-19 pandemic, there has been persistent emphasis on the importance of indoor air disinfection and ventilation in isolation units in the hospital environment. Nevertheless, no optimal and concrete disinfection protocol has been proposed to inactivate the viruses as quickly as possible. In this study, we experimentally evaluated various ventilation and disinfection protocols based on the combination of negative-pressure ventilation, ultraviolet (UV) light illumination, and Hypochlorous acid (HOCl) spray against three active virus species in a 3.5 cubic meters isolation unit. This small-size unit has gained attention during the pandemic due to the high demand for compact mobile laboratory systems capable of rapid disease diagnosis. In accordance with the WHO laboratory biosafety guidance, which states that all enclosed units where diagnostic work is conducted must ensure proper ventilation and disinfection activities, we aim to propose virus removal protocols for units compact enough to be installed within a van or deployed outdoor. The results confirmed the superiority (in terms of virus removal rate and time required) of the virus removal methods in the order of UV light, ventilation, and HOCl spray. Ultimately, we propose two optimal protocols: (i) UV light alone for three minutes, and (ii) UV light with ventilation for three minutes, followed by one-minute ventilation only. The time span of three minutes in the latter protocol is based on the clinical practice such that the medical staffs have a sufficient time to process the samples taken in transition to next patient to care.
Assuntos
Poluição do Ar em Ambientes Fechados , COVID-19 , Desinfecção , Raios Ultravioleta , Ventilação , Desinfecção/métodos , Desinfecção/instrumentação , Ventilação/métodos , Humanos , COVID-19/prevenção & controle , COVID-19/transmissão , Poluição do Ar em Ambientes Fechados/prevenção & controle , Poluição do Ar em Ambientes Fechados/análise , SARS-CoV-2 , Microbiologia do Ar , Ácido Hipocloroso , Inativação de Vírus/efeitos da radiaçãoRESUMO
The requirement to improve the efficiency of pesticide utilization has led to the development of sustainable and smart stimuli-responsive pesticide delivery systems. Herein, a novel avermectin nano/micro spheres (AVM@HPMC-Oxalate) with sensitive stimuli-response function target to the Lepidoptera pests midgut microenvironment (pH 8.0-9.5) was constructed using hydroxypropyl methylcellulose (HPMC) as the cost-effective and biodegradable material. The avermectin (AVM) loaded nano/micro sphere was achieved with high AVM loading capacity (up to 66.8 %). The simulated release experiment proved the rapid stimuli-responsive and pesticides release function in weak alkaline (pH 9) or cellulase environment, and the release kinetics were explained through release models and SEM characterization. Besides, the nano/micro sphere size made AVM@HPMC-Oxalate has higher foliar retention rate (1.6-2.1-fold higher than commercial formulation) which is beneficial for improving the utilization of pesticides. The in vivo bioassay proved that AVM@HPMC-Oxalate could achieve the long-term control of Plutella xylostella by extending UV shielding performance (9 fold higher than commercial formulation). After 3 h of irradiation, the mortality rate of P. xylostella treated by AVM@HPMC-Oxalate still up to 56.7 % ± 5.8 %. Moreover, AVM@HPMC-Oxalate was less toxic to non-target organisms, and the acute toxicity to zebrafish was reduced by 2-fold compared with AVM technical.
Assuntos
Ivermectina , Mariposas , Raios Ultravioleta , Ivermectina/análogos & derivados , Ivermectina/química , Ivermectina/farmacologia , Ivermectina/toxicidade , Animais , Mariposas/efeitos dos fármacos , Inseticidas/química , Inseticidas/farmacologia , Inseticidas/toxicidade , Celulose/química , Celulose/análogos & derivados , Derivados da Hipromelose/química , Concentração de Íons de Hidrogênio , Liberação Controlada de FármacosRESUMO
BACKGROUND: N6-Methyladenosine (m6A) methylation, a common form of RNA modification, play an important role in the pathogenesis of various diseases and in the ontogeny of organisms. Nevertheless, the precise function of m6A methylation in photoaging remains unknown. OBJECTIVES: This study aims to investigate the biological role and underlying mechanism of m6A methylation in photoaging. METHODS: m6A dot blot, Real-time quantitative PCR (RT-qPCR), western blot and immunohistochemical (IHC) assays were employed to detect the m6A level and specific m6A methylase in ultraviolet ray (UVR)-induced photoaging tissue. The profile of m6A-tagged mRNA was identified by methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA-seq analysis. Finally, we investigated the regulatory mechanism of KIAA1429 by MeRIP-qPCR, RNA knockdown and immunofluorescence assay. RESULTS: m6A levels were increased in photoaging and were closely associated with the upregulation of KIAA1429 expression. 1331 differentially m6A methylated genes were identified in the UVR group compared with the control group, of which 1192 (90%) were hypermethylated. Gene ontology analysis showed that genes with m6A hypermethylation and mRNA downregulation were mainly involved in extracellular matrix metabolism and collagen metabolism-related processes. Furthermore, KIAA1429 knockdown abolished the downregulation of TGF-bRII and upregulation of MMP1 in UVR-irradiated human dermal fibroblasts (HDFs). Mechanically, we identified MFAP4 as a target of KIAA1429-mediated m6A modification and KIAA1429 might suppress collagen synthesis through an m6A-MFAP4-mediated process. CONCLUSIONS: The increased expression of KIAA1429 hinders collagen synthesis during UVR-induced photoaging, suggesting that KIAA1429 represents a potential candidate for targeted therapy to mitigate UVR-driven photoaging.
Assuntos
Colágeno , Envelhecimento da Pele , Envelhecimento da Pele/efeitos da radiação , Envelhecimento da Pele/genética , Colágeno/metabolismo , Animais , Adenosina/análogos & derivados , Adenosina/metabolismo , Camundongos , Humanos , Raios Ultravioleta , Metilação , Fibroblastos/metabolismo , Fibroblastos/efeitos da radiaçãoRESUMO
Introduction: Photoaging-induced skin damage leads to appearance issues and dermatoma. Selenium nanoparticles (SeNPs) possess high antioxidant properties but are prone to inactivation. In this study, human serum albumin/SeNPs (HSA-SeNPs) were synthesized for enhanced stability. Methods: HSA-SeNPs were prepared by self-assembling denatured human serum albumin and inorganic selenite. The cytotoxicity of HSA-SeNPs was assessed using the MTT method. Cell survival and proliferation rates were tested to observe the protective effect of HSA-SeNPs on human skin keratinocytes against photoaging. Simultaneously, ICR mice were used for animal experiments. H&E and Masson trichromatic staining were employed to observe morphological changes in skin structure and collagen fiber disorders after UVB irradiation. Quantitative RT-PCR was utilized to measure changes in mRNA expression levels of factors related to collagen metabolism, inflammation, oxidative stress regulation, and senescence markers. Results: The HSA-SeNPs group exhibited significantly higher survival and proliferation rates of UVB-irradiated keratinocytes than the control group. Following UVB irradiation, the back skin of ICR mice displayed severe sunburn with disrupted collagen fibers. However, HSA-SeNPs demonstrated superior efficacy in alleviating these symptoms compared to SeNPs alone. In a UVB-irradiated mice model, mRNA expression of collagen type I and III was dysregulated while MMP1, inflammatory factors, and p21 mRNA expression were upregulated; concurrently Nrf2 and Gpx1 mRNA expression were downregulated. In contrast, HSA-SeNPs maintained the mRNA expression of those factors to be stable In addition, the level of SOD decreased, and MDA elevated significantly in the skin after UVB irradiation, but no significant differences in SOD and MDA levels between the HSA-SeNPs group with UVB irradiation and the UVB-free untreated group. Discussion: HSA-SeNPs have more anti-photoaging effects on the skin than SeNPs, including the protective effects on skin cell proliferation, cell survival, and structure under photoaging conditions. HSA-SeNPs can be used to protect skin from photoaging and repair skin injury caused by UVB exposure.
Assuntos
Proliferação de Células , Sobrevivência Celular , Queratinócitos , Camundongos Endogâmicos ICR , Nanopartículas , Selênio , Envelhecimento da Pele , Pele , Raios Ultravioleta , Animais , Humanos , Envelhecimento da Pele/efeitos dos fármacos , Envelhecimento da Pele/efeitos da radiação , Selênio/química , Selênio/farmacologia , Selênio/administração & dosagem , Raios Ultravioleta/efeitos adversos , Pele/efeitos dos fármacos , Pele/efeitos da radiação , Nanopartículas/química , Queratinócitos/efeitos dos fármacos , Queratinócitos/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Camundongos , Albumina Sérica Humana/química , Estresse Oxidativo/efeitos dos fármacos , Antioxidantes/farmacologia , Antioxidantes/químicaRESUMO
SIGNIFICANCE: High-energy visible (HEV) light-filtering spectacle lenses are being widely promoted despite limited evidence to support their use. The spectral transmission properties of commercially available lenses varied, particularly in the HEV light region, and they do not perform in the same way for transmission of ultraviolet (UV)-A and HEV light. PURPOSE: Although HEV light is important for several visual and nonvisual functions, there are concerns over the potential adverse effects of increased HEV light exposure. High-energy visible light-filtering spectacle lenses are being widely marketed to promote ocular health and improve sleep by reducing exposure to HEV light. This study reports on the spectral transmission characteristics of commercially available HEV light-filtering spectacle lenses based on the recommendations of the Spectral Bands Task Force technical report. METHODS: The spectral transmission of light through nine afocal plastic lenses, including eight commercially available HEV light-filtering lenses and one clear uncoated control lens, was evaluated using a Cary 5000 UV-Vis-NIR spectrophotometer (Agilent Technologies, Johannesburg, South Africa) for wavelengths 250 to 780 nm. The percentage transmission values are reported for UV radiation and visible light, with emphasis for HEV light (380 to 500 nm) and the three subbands therein. RESULTS: All lenses blocked UV-C and UV-B radiation (250 to 315 nm). For UV-A radiation (315 to 380 nm), six lenses showed optimal 100% absorption, whereas three lenses allowed ≤12%. The transmission values for the HEV light-filtering lenses ranged from 55 to 90% and 75 to 95% for HEV light of wavelengths 400 to 455 nm and 455 to 500 nm, respectively. In contrast, the control lens showed 92 (400 to 455 nm) and 93% (455 to 500 nm) transmission. CONCLUSIONS: The HEV light-filtering spectacle lenses varied in their transmission properties and do not necessarily perform in the same way for transmission of UV-A and HEV light. Optometric personnel should consider these transmission properties, particularly for HEV light, when making recommendations to patients about HEV light-filtering spectacle lenses.
Assuntos
Desenho de Equipamento , Óculos , Luz , Humanos , Raios UltravioletaRESUMO
Objectives: This study evaluates the feasibility and impact of conveying personalized sun protection message supported by a UV photograph of the face in Switzerland. Methods: 440 adults from 14 private and public sites associated with high sun exposure received a skin cancer prevention intervention composed of a facial UV-filtered photograph and individual counselling by a trained registered nurse. Pre-/post intervention surveys assessed sun protection of participants, their skin cancer risk and reasons for behavioural change. Results: The range of facial UV spots' count per individual was very broad (0-590) and mainly determined by phototype, followed by age. Three months after the intervention, 61% of participants positively changed their sun protection habit both during leisure and at work. Use of all sun protection means increased. No factor could be specifically associated to that propension for change. The individualized message was perceived as the main motivation for change. Conclusion: Personalized sun protection messages supported by a facial UV photograph led to significant favourable behavioural change in a highly sun-exposed population of adults.
Assuntos
Estudos de Viabilidade , Fotografação , Neoplasias Cutâneas , Protetores Solares , Raios Ultravioleta , Humanos , Suíça , Masculino , Feminino , Adulto , Neoplasias Cutâneas/prevenção & controle , Pessoa de Meia-Idade , Raios Ultravioleta/efeitos adversos , Protetores Solares/administração & dosagem , Comportamentos Relacionados com a Saúde , Adulto Jovem , Idoso , Queimadura Solar/prevenção & controle , Adolescente , FaceRESUMO
PURPOSE: This study aimed to identify preoperative factors that predict visual acuity and Kmax 3 years after corneal cross-linking (CXL) in patients with keratoconus (KC), and to develop a prediction model. METHODS: We enrolled 68 patients with KC and followed up on 100 eyes that received CXL for at least 3 years. Preoperative data, including age, UDVA, CDVA, cylinder, SE, and the parameters of tomography including Kmax were collected as predictors. The primary outcomes were changes in CDVA (Delta CDVA) and Kmax (Delta Kmax) postoperatively. Univariate and multivariate linear regression were used to identify the correlation between the primary outcomes and predictors and establish prediction models. RESULTS: Both CDVA and Kmax remained stable from baseline to 3 years after CXL: from 0.25 ± 0.18 to 0.22 ± 0.20 (P = 0.308) and from 58.70 ± 9.52 D to 57.02 ± 8.83 D (P = 0.187), respectively. Multivariate analysis showed that worse preoperative CDVA (ß coefficient - 0.668, P < 0.001) and lower preoperative Kmean (ß coefficient 0.018,P < 0.001) were associated with greater improvement in CDVA after CXL. A smaller preoperative eccentricity (ß coefficient 8.896, P = 0.01) and a higher preoperative Kmean (ß coefficient - 1.264, P < 0.001) predicted a more flattening of postoperative Kmax. The prediction model for CDVA (R2 = 0.43) and Kmax (R2 = 0.37) could accurately estimate treatment outcomes. CONCLUSIONS: CXL is highly effective in halting or preventing further progression of KC. The preoperative factors CDVA and Kmean were able to predict visual acuity changes 3 years after CXL. And preoperative eccentricity and Kmean could predict Kmax changes 3 years after CXL.
Assuntos
Colágeno , Topografia da Córnea , Reagentes de Ligações Cruzadas , Ceratocone , Fotoquimioterapia , Fármacos Fotossensibilizantes , Riboflavina , Raios Ultravioleta , Acuidade Visual , Humanos , Ceratocone/tratamento farmacológico , Ceratocone/diagnóstico , Ceratocone/metabolismo , Reagentes de Ligações Cruzadas/uso terapêutico , Feminino , Masculino , Fármacos Fotossensibilizantes/uso terapêutico , Adulto , Colágeno/metabolismo , Riboflavina/uso terapêutico , Fotoquimioterapia/métodos , Adulto Jovem , Seguimentos , Estudos Retrospectivos , Resultado do Tratamento , Adolescente , Refração Ocular/fisiologia , Córnea/patologia , Córnea/diagnóstico por imagem , Fatores de Tempo , Substância Própria/metabolismo , Substância Própria/efeitos dos fármacos , Crosslinking CorneanoRESUMO
Glomalin-related soil protein (GRSP) has demonstrated significant potential for water purification and remediation of heavy metals in soils; however, its redox reactivity for As(III) sequestration and the corresponding redox-active component are still poorly understood. This study investigated the photochemical properties of GRSP and its mechanism of oxidation/adsorption of As(III). The results showed that UV irradiation triggered electron transfer and the production of reactive oxygen species (ROS) in GRSP, thereby facilitating As(III) oxidation with promotion rates ranging from 43.34 % to 111.1 %. The oxidation of As(III) occurred both on the GRSP photoforming holes and in the ROS reaction from the oxygen reduction products of the photoforming electrons. OH⢠and H2O2 played an important role in the oxidation of As(III) by GRSP, especially under alkaline conditions. Moreover, the presence of Fe(III) in GRSP facilitated the formation of OH⢠and its the oxidation capacity towards As(III). The binding of As(III) to the -COOH, -OH, and -FeO groups on the GRSP surface occurred through surface complexation. Overall, these findings provided new insights into the roles of the redox-active moieties and Fe(III) on GRSP in the promoted oxidation of As(III), which would help to deepen our understanding of the migration and transformation of As(III) in soils.
Assuntos
Arsênio , Oxirredução , Poluentes do Solo , Arsênio/química , Poluentes do Solo/química , Adsorção , Ferro/química , Raios Ultravioleta , Espécies Reativas de Oxigênio/química , Proteínas Fúngicas/química , Peróxido de Hidrogênio/química , Compostos Férricos/química , Solo/química , GlicoproteínasRESUMO
The genome of living cells is constantly challenged by DNA lesions that interfere with cellular processes such as transcription and replication. A manifold of mechanisms act in concert to ensure adequate DNA repair, gene expression, and genome stability. Bulky DNA lesions, such as those induced by UV light or the DNA-damaging agent 4-nitroquinoline oxide, act as transcriptional and replicational roadblocks and thus represent a major threat to cell metabolism. When located on the transcribed strand of active genes, these lesions are handled by transcription-coupled nucleotide excision repair (TC-NER), a yet incompletely understood NER sub-pathway. Here, using a genetic screen in the yeast Saccharomyces cerevisiae, we identified histone variant H2A.Z as an important component to safeguard transcription and DNA integrity following UV irradiation. In the absence of H2A.Z, repair by TC-NER is severely impaired and RNA polymerase II clearance reduced, leading to an increase in double-strand breaks. Thus, H2A.Z is needed for proficient TC-NER and plays a major role in the maintenance of genome stability upon UV irradiation.
Assuntos
Dano ao DNA , Reparo do DNA , Instabilidade Genômica , Histonas , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Transcrição Gênica , Raios Ultravioleta , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/efeitos da radiação , Reparo do DNA/genética , Histonas/metabolismo , Histonas/genética , Instabilidade Genômica/efeitos da radiação , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Dano ao DNA/genética , RNA Polimerase II/metabolismo , RNA Polimerase II/genética , Genoma Fúngico , Quebras de DNA de Cadeia Dupla/efeitos da radiação , 4-Nitroquinolina-1-Óxido/farmacologia , Regulação Fúngica da Expressão Gênica/efeitos da radiaçãoRESUMO
The skin is constantly exposed to a variety of environmental stressors, including ultraviolet (UV) radiation. Exposure of the skin to UV radiation causes a number of detrimental biological damages such as endoplasmic reticulum (ER) stress. The ER stress response is a cytoprotective mechanism that maintains homeostasis of the ER by increasing the capacity of the ER against the accumulation of unfolded proteins in the ER. Carvacrol (CRV) is a monoterpenoid phenol found in essential oils with antimicrobial and anti-inflammatory activities. We investigated for the first time in the literature the potential protective role of CRV against combined UVA and UVB-induced skin damage by targeting the ER stress pathway in a rat model. For this purpose, expressions of Grp78, Perk, Atf6, Ire-1, Chop, Xbp1, Casp12, elF2α, and Traf2 genes related to ER stress were analyzed by RT-PCR and protein expression levels of GRP78, ATF6, CHOP, and XBP1 were determined by ELISA assay in tissue sections taken from the back of the rats. As a result of analysis, it was seen that the expression levels of aforementioned ER stress genes increased significantly in the UVA + UVB irradiated group compared to the control group, while their expression levels decreased markedly by supplementation of CRV in UVA + UVB + CRV group. With regard to expressions of foregoing proteins, their levels escalated notably with UVA + UVB application and decreased markedly by CRV supplementation. In conclusion, present study revealed that CRV ameliorates UVA + UVB-induced ER stress via reducing the expression of mRNA as well as proteins involved in the unfolded protein response (UPR) pathway and inducing apoptosis as evidenced from high Caspase12 level.
Assuntos
Cimenos , Estresse do Retículo Endoplasmático , Raios Ultravioleta , Animais , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Raios Ultravioleta/efeitos adversos , Cimenos/farmacologia , Ratos , Pele/efeitos dos fármacos , Pele/patologia , Pele/efeitos da radiação , Pele/metabolismo , Monoterpenos/farmacologia , Monoterpenos/química , Masculino , Ratos WistarRESUMO
Fungal contamination poses a serious threat to public health and food safety because molds can grow under stressful conditions through melanin accumulation. Although ultraviolet (UV) irradiation is popular for inhibiting microorganisms, its effectiveness is limited by our insufficient knowledge about UV tolerance in melanin-accumulating molds. In this study, we first confirmed the protective effect of melanin by evaluating the UV sensitivity of young and mature spores. Additionally, we compared UV sensitivity between spores with accumulated melanin and spores prepared with melanin biosynthesis inhibitors. We found that mature spores were less UV-sensitive than young spores, and that reduced melanin accumulation by inhibitors led to reduced UV sensitivity. These results suggest that melanin protects cells against UV irradiation. To determine the most effective wavelength for inhibition, we evaluated the wavelength dependence of UV tolerance in a yeast (Rhodotorula mucilaginosa) and in molds (Aspergillus fumigatus, Cladosporium halotolerans, Cladosporium sphaerospermum, Aspergillus brasiliensis, Penicillium roqueforti, and Botrytis cinerea). We assessed UV tolerance using a UV-light emitting diode (LED) irradiation system with 13 wavelength-ranked LEDs between 250 and 365 nm, a krypton chlorine (KrCl) excimer lamp device, and a low pressure (LP) Hg lamp device. The inhibition of fungi peaked at around 270 nm, and most molds showed reduced UV sensitivity at shorter wavelengths as they accumulated pigment. Absorption spectra of the pigments showed greater absorption at shorter wavelengths, suggesting greater UV protection at these wavelengths. These results will assist in the development of fungal disinfection systems using UV, such as closed systems of air and water purification.
Assuntos
Melaninas , Raios Ultravioleta , Melaninas/metabolismo , Melaninas/química , Melaninas/biossíntese , Esporos Fúngicos/efeitos da radiação , Esporos Fúngicos/metabolismo , Esporos Fúngicos/efeitos dos fármacos , Fungos/metabolismo , Fungos/efeitos da radiação , Fungos/efeitos dos fármacos , Rhodotorula/metabolismo , Rhodotorula/efeitos da radiação , Cladosporium/metabolismo , Cladosporium/químicaRESUMO
Background: Repeated acute exposure to ultraviolet B (UVB) rays can cause photoaging. Musa balbisiana peel contains flavonoid compounds which act as antioxidants. However, the physicochemicals of flavonoids are unstable, have high molecular weight, and are easily oxidized, causing their use is still limited and transdermal delivery to be inefficient. Aim: To investigate the ameliorative effect of transfersome gel of M. balbisiana peels against photoaging in Wistar rat skin. Methods: Transfersome gel was characterized by transmission electron microscopy (TEM). In vivo research was used to determine the ameliorative effects of M. balbisiana peel. The composition of transfersome consists of ethanol extracts of M. balbisiana peel, soybean phosphatidylcholine, and tween 80. The gel was applied three times a week for 4 weeks with a total UVB radiation dose of 840 mJ/cm2. To evaluate the repair mechanism by measuring the degree of wrinkles, epidermal thickening, dermal thinning, collagen fiber irregularity, matrix metalloproteinase 1 (MMP-1), and transforming growth factor-ß (TGF-ß) expression, malondialdehyde (MDA) and tumor necrosis factor-α (TNFα) levels. Results: TEM results show that gel transfersome M. balbisiana peel has a round morphology with a diameter of ±50 nm and no aggregation, which are defined as nanoparticles. Transfersome gel ameliorated the degree of wrinkle, epidermal thickening, dermal thinning, and irregularity of collagen fibers caused by UVB exposure, suppresses lipid peroxidation by decreasing MDA and TNFα level, also collagen imbalance by inhibiting MMP-1 expression and activating TGF-ß expression, which was found statistically significantly different from non-transfersome gel group. Conclusion: Transfersome gel of M. balbisiana peel can act as an alternative medicine to ameliorate clinical photoaging due to exposure to UVB.
Assuntos
Musa , Extratos Vegetais , Ratos Wistar , Envelhecimento da Pele , Raios Ultravioleta , Animais , Envelhecimento da Pele/efeitos dos fármacos , Envelhecimento da Pele/efeitos da radiação , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Extratos Vegetais/administração & dosagem , Ratos , Musa/química , Raios Ultravioleta/efeitos adversos , Pele/efeitos dos fármacos , Pele/efeitos da radiação , Géis/química , FemininoRESUMO
Oxidative damage contributes to age-related macular degeneration. Irigenin possesses diverse pharmacologic properties, including antioxidative and antiapoptotic effects. Our in vivo experiments indicated that irigenin mitigates UVB-induced histopathologic changes and oxidative DNA damage. Histologic analyses and TUNEL staining revealed that this compound dose-dependently ameliorated UVB-induced retinal damage and apoptosis. Furthermore, irigenin substantially reduced the level of 8-hydroxyguanosine, a biomarker of UVB-induced oxidative DNA damage. We further explored the molecular mechanisms that mediate the protective effects of irigenin. Our findings suggested that UVB-induced generation of ROS disrupts the stability of the mitochondrial membrane, activating intrinsic apoptotic pathways; the underlying mechanisms include the release of cytochrome c, activation of caspase-9 and caspase-3, and subsequent degradation of PARP-1. Notably, irigenin reversed mitochondrial disruption and apoptosis. It also modulated the Bax and Bcl-2 expression but influenced the mitochondrial apoptotic pathways. Our study highlights the role of the Nrf2 pathway in mitigating the effects of oxidative stress. We found that UVB exposure downregulated, but irigenin treatment upregulated the expression of Nrf2 and antioxidant enzymes. Therefore, irigenin activates the Nrf2 pathway to address oxidative stress. In conclusion, irigenin exhibits protective effects against UVB-induced ocular damage, evidenced by the diminution of histological alterations. It mitigates oxidative DNA damage and apoptosis in the retinal tissues by modulating the intrinsic apoptotic pathways and the AIF mechanisms. Furthermore, irigenin effectively reduces lipid peroxidation, enhancing the activity of antioxidant enzymes by stimulating the Nrf2 pathway. This protective mechanism underscores the potential benefit of irigenin in combating UVB-mediated ocular damage.