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1.
Artigo em Inglês | MEDLINE | ID: mdl-38432774

RESUMO

The ultraviolet (UV) component of sunlight can damage DNA. Although most solar UV is absorbed by the ozone layer, wavelengths > 300 nm (UVA and UVB bands) can reach the Earth's surface. It is essential to understand the genotoxic effects of UV light, particularly in natural environments. Caulobacter crescentus, a bacterium widely employed as a model for cell cycle studies, was selected for this study. Strains proficient and deficient in DNA repair (uvrA-) were used to concurrently investigate three genotoxic endpoints: cytotoxicity, SOS induction, and gene mutation, using colony-formation, the SOS chromotest, and RifR mutagenesis, respectively. Our findings underscore the distinct impacts of individual UV bands and the full spectrum of sunlight itself in C. crescentus. UVC light was highly genotoxic, especially for the repair-deficient strain. A UVB dose equivalent to 20 min sunlight exposure also affected the cells. UVA exposure caused a significant response only at high doses, likely due to activation of photorepair. Exposure to solar irradiation resulted in reduced levels of SOS induction, possibly due to decreased cell survival. However, mutagenicity is increased, particularly in uvrA- deficient cells.


Assuntos
Caulobacter crescentus , Raios Ultravioleta , Raios Ultravioleta/efeitos adversos , Caulobacter crescentus/genética , Dano ao DNA , Reparo do DNA , Mutação
2.
J Refract Surg ; 40(3): e148-e155, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38466760

RESUMO

PURPOSE: To assess the safety and efficacy of treatment and secondarily determine the topographic changes, visual outcomes, and demarcation line depth after high-fluence pulsed light accelerated cross-linking (ACXL) in pediatric patients (younger than 18 years) with progressive keratoconus. METHODS: This retrospective analysis included 32 eyes (25 children, aged 11 to 18 years), with progressive keratoconus treated with high-energy epithelium-off pulsed light ACXL (7.2 J/cm2, 15 mW/cm2, 12 minutes, 2 seconds on/1 second off). Corrected distance visual acuity (CDVA), Scheimpflug tomography, and anterior optical coherence tomography measurements were recorded preoperatively and 1, 2, and 3 years postoperatively. RESULTS: A total of 32 eyes were included. Significant CDVA improvement, pachymetry, and maximum keratometry reduction were found at all follow-up visits. Mean keratometric values remained stable, and astigmatism showed a mild worsening (< 0.25 D) with statistical significance at 1 and 3 years. Total aberration showed discordant results and coma aberration had a slight improvement without statistical significance. The demarcation line depth was 265 ± 26 µm. Three patients developed mild haze without visual acuity loss. None of the patients underwent a second CXL procedure. CONCLUSIONS: In pediatric patients, high-fluence epithelium-off pulsed light ACXL appears to be a safe and effective procedure to halt the progression of keratoconus, slightly improving the CDVA and keratometric values. [J Refract Surg. 2024;40(3):e148-e155.].


Assuntos
Ceratocone , Fotoquimioterapia , Humanos , Criança , Ceratocone/tratamento farmacológico , Fármacos Fotossensibilizantes/uso terapêutico , Crosslinking Corneano , Riboflavina/uso terapêutico , Estudos Retrospectivos , Raios Ultravioleta , Topografia da Córnea , Reagentes de Ligações Cruzadas/uso terapêutico , Colágeno/uso terapêutico , Fotoquimioterapia/métodos , Epitélio
3.
Huan Jing Ke Xue ; 45(3): 1553-1560, 2024 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-38471869

RESUMO

In this study, the degradation efficiency and mechanism of carbamazepine (CBZ), a typical emerging contaminant in water, in the UV/sulfite process were investigated. The effects of different concentrations of dissolved oxygen [ρ(DO)] on the degradation of CBZ by UV-activated sulfite were investigated. Additionally, under a simulated natural water environment-controlled initial ρ(DO) of (8.0 ±0.2) mg·L-1, the effects of different process parameters (sulfite dosages and reaction pH) and water environmental factors (the presence of HCO3-, Cl-, and humic acids) on the degradation of CBZ were comprehensively analyzed. The results showed that the UV/sulfite process efficiently degraded CBZ with a degradation rate of 85.3% during the 30 min reaction time and followed the pseudo-first order kinetic model with the constant of 0.055 7 min-1. Using the electron spin resonance detection, reactive species quenching tests, and the competition kinetics, the sulfate radicals (SO4-·) and hydroxyl radicals (·OH) in the UV/sulfite process were determined to be the main reactive species and were responsible for the degradation of CBZ with contribution rates of 43.9% and 56.1%, respectively. In addition, the degradation efficiency of CBZ decreased with the increasing concentration of HCO3-, and the presence of Cl- had little effect on the degradation of CBZ, whereas the presence of humic acids significantly inhibited the degradation of CBZ. Moreover, the accumulation of sulfate during the reaction was significantly lower than the limit of the Standard for Drinking Water (GB5749-2022). Additionally, the sulfite consumption rate constant was 0.004 4 min-1, which was significantly lower than the degradation rate constant of CBZ, indicating that sulfite could be activated efficiently by UV light to degrade CBZ in water.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Água , Raios Ultravioleta , Substâncias Húmicas , Poluentes Químicos da Água/análise , Carbamazepina/análise , Cinética , Sulfitos , Sulfatos , Purificação da Água/métodos , Oxirredução
4.
Sci Rep ; 14(1): 5997, 2024 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-38472290

RESUMO

When analyzing health data in relation to environmental stressors, it is crucial to identify which variables to include in the statistical model to exclude dependencies among the variables. Four meteorological parameters: temperature, ultraviolet radiation, precipitation, and vapor pressure and four outdoor air pollution parameters: ozone ( O 3 ), nitrogen dioxide ( NO 2 ), particulate matter ( P M 2.5 , P M 10 ) were studied on a daily basis for Baden-Württemberg (Germany). This federal state covers urban and rural compartments including mountainous and river areas. A temporal and spatial analysis of the internal relationships was performed among the variables using (a) cross-correlations, both on the grand ensemble of data as well as within subsets, and (b) the Local Indications of Spatial Association (LISA) method. Meteorological and air pollution variables were strongly correlated within and among themselves in time and space. We found a strong interaction between nitrogen dioxide and ozone, with correlation coefficients varying over time. The coefficients ranged from negative correlations in January (-0.84), April (-0.47), and October (-0.54) to a positive correlation in July (0.45). The cross-correlation plot showed a noticeable change in the correlation direction for O 3 and NO 2 . Spatially, NO 2 , P M 2.5 , and P M 10 concentrations were significantly higher in urban than rural regions. For O 3 , this effect was reversed. A LISA analysis confirmed distinct hot and cold spots of environmental stressors. This work examined and quantified the spatio-temporal relationship between air pollution and meteorological conditions and recommended which variables to prioritize for future health impact analyses. The results found are in line with the underlying physico-chemical atmospheric processes. It also identified postal code areas with dominant environmental stressors for further studies.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Ozônio , Poluentes Atmosféricos/análise , Dióxido de Nitrogênio/análise , Raios Ultravioleta , Poluição do Ar/análise , Material Particulado/análise , Ozônio/análise , Monitoramento Ambiental/métodos
5.
Int J Mol Sci ; 25(5)2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38473996

RESUMO

With the continuous development of space station construction, space ecosystem research has attracted increasing attention. However, the complicated responses of different candidate plants and algae to radiation stress remain unclear. The present study, using integrated physiologic and proteomic analyses, was carried out to reveal the molecular mechanism of Navicula sp. in response to ultraviolet (UV) irradiation stress. Under 12~24 h of high-dose UV irradiation conditions, the contents of chlorophyll and soluble proteins in Navicula sp. cells were significantly higher than those in the control and 4~8 h of low-dose UV irradiation groups. The activity of catalase (CAT) increased with the extension of irradiation time, and the activity of superoxide dismutase (SOD) decreased first and then increased. Furthermore, differential volcano plot analysis of the proteomic data of Navicula sp. samples found only one protein with a significant difference. Differential protein GO analysis unveiled that UV irradiation can activate the antioxidant system of Navicula sp. and further impact photosynthesis by affecting the photoreaction and chlorophyll synthesis of Navicula sp. The most significant differences in KEGG pathway analysis were also associated with photosynthesis. The above results indicate that Navicula sp. has good UV radiation resistance ability by regulating its photosynthetic pigment content, photosynthetic activity, and antioxidant system, making it a potential candidate for the future development of space ecosystems.


Assuntos
Antioxidantes , Raios Ultravioleta , Antioxidantes/metabolismo , Ecossistema , Proteômica , Clorofila/metabolismo , Fotossíntese , Plantas/metabolismo
6.
Phys Chem Chem Phys ; 26(11): 8879-8890, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38426309

RESUMO

Radiation therapy uses ionizing radiation to break chemical bonds in cancer cells, thereby causing DNA damage and leading to cell death. The therapeutic effectiveness can be further increased by making the tumor cells more sensitive to radiation. Here, we investigate the role of the initial halogen atom core hole on the photofragmentation dynamics of 2-bromo-5-iodo-4-nitroimidazole, a potential bifunctional radiosensitizer. Bromine and iodine atoms were included in the molecule to increase the photoionization cross-section of the radiosensitizer at higher photon energies. The fragmentation dynamics of the molecule was studied experimentally in the gas phase using photoelectron-photoion-photoion coincidence spectroscopy and computationally using Born-Oppenheimer molecular dynamics. We observed significant changes between shallow core (I 4d, Br 3d) and deep core (I 3d) ionization in fragment formation and their kinetic energies. Despite the fact, that the ions ejected after deep core ionization have higher kinetic energies, we show that in a cellular environment, the ion spread is not much larger, keeping the damage well-localized.


Assuntos
Iodo , Nitroimidazóis , Raios Ultravioleta , Fótons , Radiação Ionizante
7.
Exp Dermatol ; 33(3): e15044, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38465766

RESUMO

Polycyclic aromatic hydrocarbons with the key substance benzo[a]pyrene (B[a]P) are widespread pollutants in the environment and at working places. Nonetheless, the exact underlying mechanisms of toxicological effects caused by B[a]P especially in absence and presence of UV irradiation remain uncertain. This study examines variations in exposure conditions: low B[a]P (4 nM), low B[a]P + UV and high B[a]P (4 µM), selected based on pertinent cytotoxicity assessments. Following cell viability evaluations post-treatment with varied B[a]P concentrations and UV irradiation, the identified concentrations underwent detailed metabolomic analysis via gas chromatography-mass spectrometry. Subsequently, resulting changes in metabolic profiles across these distinct exposure groups are comprehensively compared. Chemometric analyses showed modest regulation of metabolites after low B[a]P exposure compared to control conditions. High B[a]P and low B[a]P + UV exposure significantly increased regulation of metabolic pathways, indicating that additional UV irradiation plus low B[a]P is as demanding for the cells as higher B[a]P treatment alone. Further analysis revealed exposure-dependent regulation of glutathione-important for oxidative defence-and purine metabolism-important for DNA base synthesis. Only after low B[a]P, oxidative defence appeared to be able to compensate for B[a]P-induced perturbations of the oxidative homeostasis. In contrast, purine metabolism already responded towards adversity at low B[a]P. The metabolomic results give an insight into the mechanisms leading to the toxic response and confirm the strong effects of co-exposure on oxidative defence and DNA repair in the model studied.


Assuntos
Benzo(a)pireno , Hidrocarbonetos Policíclicos Aromáticos , Benzo(a)pireno/toxicidade , Benzo(a)pireno/metabolismo , Queratinócitos/metabolismo , Raios Ultravioleta , Glutationa/metabolismo , Purinas/farmacologia
8.
Exp Dermatol ; 33(3): e15034, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38459631

RESUMO

Polymorphic light eruption (PLE) has been mechanistically linked to cytokine abnormalities. Emerging preclinical evidence posits the skin microbiome as a critical modulator of ultraviolet (UV)-induced cytokine expression, thereby influencing subsequent immune responses. This intricate relationship remains underexplored in the context of PLE. Hence, we investigated the differential responses between disinfected and non-disinfected skin following both single and repetitive exposures to solar-simulated UV radiation in patients with PLE. An experimental, half-body pilot study was conducted involving six PLE patients and 15 healthy controls. Participants' skin was exposed to single and multiple doses of solar-simulated UV radiation, both in disinfected and in non-disinfected skin areas. The co-primary outcomes were PLE score and cytokine expression in blister fluid analysed through OLINK proteomic profiling. Secondary outcomes were erythema, pigmentation, induction of apoptotic cells in vacuum-generated suction blisters, and density of infiltrate in skin biopsies of PLE patients. Among the 71 cytokines analysed, baseline expression levels of 20 specific cytokines-integral to processes such as apoptosis, inflammation, immune cell recruitment, cellular growth, and differentiation-were significantly impaired in PLE patients compared with healthy controls. Notably, skin disinfection reversed the observed cytokine imbalances following a single UV exposure at the minimal erythema dose (MED) level and exhibited even more pronounced effects after multiple UV exposures. However, no significant differences were evident in PLE score, erythema, pigmentation, or rates of apoptotic cell induction upon UV radiation. These findings provide evidence for UV-driven cytokine regulation by the skin microbiota and imply microbiome involvement in the PLE immune response.


Assuntos
Dermatite de Contato , Transtornos de Fotossensibilidade , Humanos , Transtornos de Fotossensibilidade/metabolismo , Projetos Piloto , Proteômica , Pele/patologia , Raios Ultravioleta , Citocinas , Eritema
9.
J Cancer Res Clin Oncol ; 150(3): 130, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38489072

RESUMO

Psoralen is a family of naturally occurring photoactive compounds found in plants that acquire potential cytotoxicity when activated by specific frequencies of electromagnetic waves. Psoralens penetrate the phospholipid cellular membranes and insert themselves between the pyrimidines of deoxyribonucleic acid (DNA). Psoralens are initially biologically inert and acquire photoreactivity when exposed to certain classes of electromagnetic radiation, such as ultraviolet light. Once activated, psoralens form mono- and di-adducts with DNA, leading to marked cell apoptosis. This apoptotic effect is more pronounced in tumor cells due to their high rate of cell division. Moreover, photoactivated psoralen can inhibit tyrosine kinase signaling and influence the immunogenic properties of cells. Thus, the cytotoxicity of photoactivated psoralen holds promising clinical applications from its immunogenic properties to potential anti-cancer treatments. This narrative review aims to provide an overview of the current understanding and research on psoralen and to explore its potential future pharmacotherapeutic benefits in specific diseases.


Assuntos
Ficusina , Furocumarinas , Humanos , Ficusina/farmacologia , Ficusina/uso terapêutico , Furocumarinas/farmacologia , Raios Ultravioleta , DNA
10.
Proc Natl Acad Sci U S A ; 121(14): e2308374121, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38489380

RESUMO

Ultraviolet radiation (UVR) is primarily recognized for its detrimental effects such as cancerogenesis, skin aging, eye damage, and autoimmune disorders. With exception of ultraviolet B (UVB) requirement in the production of vitamin D3, the positive role of UVR in modulation of homeostasis is underappreciated. Skin exposure to UVR triggers local responses secondary to the induction of chemical, hormonal, immune, and neural signals that are defined by the chromophores and extent of UVR penetration into skin compartments. These responses are not random and are coordinated by the cutaneous neuro-immuno-endocrine system, which counteracts the action of external stressors and accommodates local homeostasis to the changing environment. The UVR induces electrical, chemical, and biological signals to be sent to the brain, endocrine and immune systems, as well as other central organs, which in concert regulate body homeostasis. To achieve its central homeostatic goal, the UVR-induced signals are precisely computed locally with transmission through nerves or humoral signals release into the circulation to activate and/or modulate coordinating central centers or organs. Such modulatory effects will be dependent on UVA and UVB wavelengths. This leads to immunosuppression, the activation of brain and endocrine coordinating centers, and the modification of different organ functions. Therefore, it is imperative to understand the underlying mechanisms of UVR electromagnetic energy penetration deep into the body, with its impact on the brain and internal organs. Photo-neuro-immuno-endocrinology can offer novel therapeutic approaches in addiction and mood disorders; autoimmune, neurodegenerative, and chronic pain-generating disorders; or pathologies involving endocrine, cardiovascular, gastrointestinal, or reproductive systems.


Assuntos
Pele , Raios Ultravioleta , Sistema Imunitário , Encéfalo , Sistemas Neurossecretores
11.
Sci Total Environ ; 922: 171339, 2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38428595

RESUMO

Inappropriate sterilization strategies inhibit microalgal growth when culturing microalgae with anaerobic digestate. This study aimed to scientifically select a low-cost disinfection pretreatment of anaerobic digestate for large-scale microalgae cultivations. In this work, three different methods, including autoclaving, ultraviolet or NaClO treatments, were employed to sterilize the municipal anaerobic digestate. Scenedesmus quadricauda was then cultured in diluted liquid digestate for the simultaneous lipid production and nutrient removal. The results indicated that the growth of S. quadricauda was inhibited after NaClO treatment due to the residual free chlorine. The 15-min ultraviolet effectively mitigated microbial contamination and increasing nutrient availability, enhancing the electron transport of microalgal photosynthesis. After 6-days cultivation, the microalgal biomass concentration of the ultraviolet group was 1.09 g/L, comparable to that of the autoclaving group (1.15 g/L). High nutrient removal efficiency was observed: COD (93.30 %), NH4+-N (92.56 %), TN (85.82 %) and TP (95.12 %). Moreover, S. quadricauda outcompeted the indigenous microorganisms, contributing to its dominance in the culture system of ultraviolet group. The facultative anaerobe Comamonadaceae and aerobes Moraxellaceae, rather than strict anaerobe Paludibacteraceae and Bacteroidetes_vadinHA17, played vital roles in synergistic removal of contaminants by bacteria and algae. The potential competition for nitrogen and phosphorus by bacteria contributed to the ultraviolet group having the greatest lipid content (48.19 %). Therefore, this work suggested using 15-min ultraviolet treatment for anaerobic digestate in large-scale microalgae cultivation.


Assuntos
Microalgas , Scenedesmus , Raios Ultravioleta , Anaerobiose , Bactérias , Biomassa , Nitrogênio , Bacteroidetes , Lipídeos
12.
Sci Total Environ ; 922: 171317, 2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38428610

RESUMO

Sequential utilization of ozone (O3) and biological activated carbon (BAC) followed by UV/chlor(am)ine advanced oxidation process (AOP) has drawn attention in water reuse. However, the formation of disinfection by-products (DBPs) in this process is less evaluated. This study investigated the DBP formation and the relevant toxicity during the O3-BAC-UV/chlor(am)ine treatment of sand-filtered municipal secondary effluent. DBP formation in UV/chlorine and UV/dichloramine (NHCl2) processes were compared, where the impact of key operational parameters (e.g., UV wavelength, pH) on DBP formation were comprehensively evaluated. O3-BAC significantly reduced DBP formation potential (DBPFP) (58.2 %). Compared to UV/chlorine AOP, UV/NHCl2 AOP reduced DBP formation by 29.7 % in short-time treatment, while insignificantly impacting on DBPFP (p > 0.05). UV/NHCl2 AOP also led to lower calculated cytotoxicity (67.7 %) and genotoxicity (55.9 %) of DBPs compared to UV/chlorine AOP. Compared to 254 nm UV light, the utilization of 285 nm UV light decreased the formation of DBPs in wastewater treated with the UV/chlorine AOP and UV/NHCl2 AOP by 31.3 % and 19.2 %, respectively. However, the cytotoxicity and genotoxicity in UV/NHCl2 AOP using 285 nm UV light increased by 83.4 % and 58.5 %, respectively, compared to 254 nm. The concentration of DBPs formed in the UV/NHCl2 AOP at pH 8 was 54.3 % lower than that at pH 7, suggesting a better control of DBPs at alkaline condition. In the presence of bromide, UV/NHCl2 AOP tended to generate more brominated DBPs than UV/chlorine AOP. Overall, UV/NHCl2 AOP resulted in lower concentration and toxicity of DBPs compared to UV/chlorine AOP.


Assuntos
Desinfetantes , Ozônio , Poluentes Químicos da Água , Purificação da Água , Desinfecção/métodos , Carvão Vegetal , Águas Residuárias , Cloro , Raios Ultravioleta , Purificação da Água/métodos , Halogenação , Poluentes Químicos da Água/análise
13.
Int Ophthalmol ; 44(1): 145, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38498219

RESUMO

PURPOSE: To compare the visual, refractive, and topographic outcomes of a high irradiance accelerated corneal crosslinking (ACXL) protocol after a 12-month follow-up between pediatric and adult patients with progressive keratoconus (KC). METHODS: Retrospective, comparative, cohort study. Patients with KC were divided into two groups: pediatric (≤ 18 years) and adult (> 18 years). All of them were managed with epi-OFF ACXL (30 mW/cm2, 8 min, pulsed 1:1 on and off = 7.2 J/cm2). Visual, refractive, and topographic values were measured preoperatively and at 1, 3, 6, and 12 months postoperative. KC progression, defined as a Kmax increase of ≥ 1D during follow-up, was recorded. RESULTS: Eighty-nine eyes (53 patients) were included for analysis; 45 (50.6%) eyes were from pediatric patients and 44 (49.4%) from adults. At one-year follow-up, pediatric patients experienced significantly higher rates of progression (22.2% vs. 4.5%, p = .014). Contrariwise, female gender (Beta = - 3.62, p = .018), a baseline uncorrected visual acuity of Snellen ≥ 20/60 (Beta = - 5.96, p = .007), and being ≥ 15 years at ACXL treatment (Beta = - 0.31, p = .021) were associated with non-progressive disease. A significant improvement in best-corrected visual acuity, Kmin, Km, and Kmax was recorded in both groups. Overall, 86.5% of eyes from both groups showed Kmax stabilization or improvement. CONCLUSIONS: Despite the similarity in visual, refractive, and topographic outcomes in both groups, younger age was associated with KC progression after ACXL at one year of follow-up.


Assuntos
Ceratocone , Fotoquimioterapia , Adulto , Humanos , Feminino , Criança , Ceratocone/diagnóstico , Ceratocone/tratamento farmacológico , Fármacos Fotossensibilizantes/uso terapêutico , Fotoquimioterapia/métodos , Crosslinking Corneano , Estudos Retrospectivos , Estudos de Coortes , Riboflavina/uso terapêutico , Raios Ultravioleta , Topografia da Córnea/métodos , Seguimentos , Reagentes de Ligações Cruzadas/uso terapêutico , Colágeno/uso terapêutico
14.
Int Ophthalmol ; 44(1): 146, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38499839

RESUMO

PURPOSE: To evaluate the effect of transepithelial corneal collagen crosslinking (CXL) treatment on the optical performance of the cornea at 12-month follow-up after CXL in patients with progressive keratoconus. METHODS: One hundred and ten eyes of 67 patients were included. The following corneal optical aberrations over the 4-mm-diameter pupil were recorded via Sirius dual-scanning corneal tomography: total, anterior and posterior amount of corneal higher order aberrations [HOAs], vertical coma, horizontal coma, vertical trefoil, oblique trefoil, and spherical aberration, and Strehl ratio of point spread function (PSF). RESULTS: There were significant improvements in mean root mean square error values for corneal total HOA, total coma, anterior HOA, anterior coma, and vertical coma following CXL (P > 0.05, for all). No significant changes were found in the posterior aberometric parameters. PSF value did not change after CXL (P > 0.05). The corneal topographic measurements not revealed a change in the mean simulated keratometry-1, simulated keratometry-2, and maximum keratometry compared with the baseline measurements (P > 0.05, for all). At 12 months, there was a significant improvement in the uncorrected (UCVA) and best corrected (BCVA) visual acuity (P < 0.001, both). Most corneal aberrations correlated significantly with postoperative BCVA, but changes in HOAs were not statistically associated with improvements in visual acuity. CONCLUSIONS: Transepithelial CXL was effective in stabilizing the keratometric indices and improving the most corneal aberrations in keratoconic eyes 1 year after the procedure. While the healing effect on aberrations after CXL was in total and anterior parameters, no significant changes were observed in the posterior surface. In addition, it was observed that transepithelial CXL treatment did not cause a significant change in PSF distribution data.


Assuntos
Ceratocone , Fotoquimioterapia , Humanos , Ceratocone/diagnóstico , Ceratocone/tratamento farmacológico , Crosslinking Corneano , Coma , Fármacos Fotossensibilizantes/uso terapêutico , Riboflavina/uso terapêutico , Córnea , Topografia da Córnea , Fotoquimioterapia/métodos , Colágeno/uso terapêutico , Reagentes de Ligações Cruzadas/uso terapêutico , Raios Ultravioleta
15.
Sci Rep ; 14(1): 6476, 2024 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-38499606

RESUMO

Ordered, quasi-ordered, and even disordered nanostructures can be identified as constituent components of several protists, plants and animals, making possible an efficient manipulation of light for intra- and inter- species communication, camouflage, or for the enhancement of primary production. Diatoms are ubiquitous unicellular microalgae inhabiting all the aquatic environments on Earth. They developed, through tens of millions of years of evolution, ultrastructured silica cell walls, the frustules, able to handle optical radiation through multiple diffractive, refractive, and wave-guiding processes, possibly at the basis of their high photosynthetic efficiency. In this study, we employed a range of imaging, spectroscopic and numerical techniques (including transmission imaging, digital holography, photoluminescence spectroscopy, and numerical simulations based on wide-angle beam propagation method) to identify and describe different mechanisms by which Pleurosigma strigosum frustules can modulate optical radiation of different spectral content. Finally, we correlated the optical response of the frustule to the interaction with light in living, individual cells within their aquatic environment following various irradiation treatments. The obtained results demonstrate the favorable transmission of photosynthetic active radiation inside the cell compared to potentially detrimental ultraviolet radiation.


Assuntos
Diatomáceas , Nanoestruturas , Animais , Diatomáceas/fisiologia , Raios Ultravioleta , Nanoestruturas/química , Fotossíntese , Dióxido de Silício/química
16.
Int J Food Microbiol ; 415: 110632, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38428167

RESUMO

The objectives of this research were to study the effect of UV irradiation on quality characteristics of mango juice during cold storage. Mango juice exposed to UV radiation was also used to determine zero-order and first-order kinetic models of microbial (total plate count, yeast and mold count, and Escherichia coli) reduction. According to the microbiological results, UV light at 120 J/cm2 caused a 5.19 log reduction. It was found that microbial inactivation of all tested microorganisms followed first-order kinetic model. The treatments did not differ significantly in terms of the quality metrics. L*, b*, pH, total soluble solid, total phenolic compound, total flavonoid content, and antioxidant activity as measured by the DPPH and FRAP assay all tended to decline during storage at 4 °C, whereas a*, ∆E, titratable acidity, total plate count, yeast and mold count, as well as the total plate count, had an increasing trend. During storage at 4 °C, UV irradiation increased the shelf life of mango juice by about 14 days compared to the control sample. In conclusion, this study demonstrated the potential of UV treatment as an alternative to thermal pasteurization for preserving mango juice quality and safety while also prolonging shelf life.


Assuntos
Mangifera , Pasteurização , Pasteurização/métodos , Raios Ultravioleta , Saccharomyces cerevisiae/efeitos da radiação , Antioxidantes/análise
17.
J Am Chem Soc ; 146(11): 7222-7232, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38469853

RESUMO

Defect centers in a nanodiamond (ND) allow the detection of tiny magnetic fields in their direct surroundings, rendering them as an emerging tool for nanoscale sensing applications. Eumelanin, an abundant pigment, plays an important role in biology and material science. Here, for the first time, we evaluate the comproportionation reaction in eumelanin by detecting and quantifying semiquinone radicals through the nitrogen-vacancy color center. A thin layer of eumelanin is polymerized on the surface of nanodiamonds (NDs), and depending on the environmental conditions, such as the local pH value, near-infrared, and ultraviolet light irradiation, the radicals form and react in situ. By combining experiments and theoretical simulations, we quantify the local number and kinetics of free radicals in the eumelanin layer. Next, the ND sensor enters the cells via endosomal vesicles. We quantify the number of radicals formed within the eumelanin layer in these acidic compartments by applying optical relaxometry measurements. In the future, we believe that the ND quantum sensor could provide valuable insights into the chemistry of eumelanin, which could contribute to the understanding and treatment of eumelanin- and melanin-related diseases.


Assuntos
Melaninas , Nanodiamantes , Raios Ultravioleta , Radicais Livres
18.
Sci Rep ; 14(1): 6604, 2024 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-38503785

RESUMO

The media and even the specialized literature report that the ultraviolet (UV) protection for sunglasses is critical, on the grounds that sunglasses can have a counter effect if the lenses do not provide adequate UV protection. They reason that the primary and natural mechanism is that the pupil of the eye contracts to attenuate radiation and protect the inner eye under sun exposure. Therefore, if dark lenses do not provide appropriate UV protection, there is an increased UV incidence in the inner eye due to pupil dilation, which enhances the adverse effects and impacts the ocular tissues more severely than in situations without UV protection. However, no existing literature properly quantified or supported this argument. In this work, the influx of solar UV throughout the pupil of the eye was calculated in two situations: when a person wear sunglasses and when he/she does not. In both situations, the pupil dilation and the field of view (squint) were considered with their dependence on the brightness of the ambient, calculated by modeling the solar irradiation. Finally, it was assessed whether sunglasses with poor UV protection actually increase the UV influx throughout the dilated pupil compared to the non-dilated pupil. A set of 214 sunglasses lenses were tested and the results show that pupil dilation does not play an important role in the UV influx throughout the pupil. It was observed that the FOV is the main player, surpassing the pupil size contribution by up to 314.3%, disproving the common explanation. Because of the major role of the FOV, our results show that sunglasses with UV-A protection below 86% may have a slight potential to increase hazards to the eye compared to not wearing sunglasses at all. These results can have direct impact on sunglasses standards regarding the UV protection linked to the category of the lenses.


Assuntos
Luz Solar , Raios Ultravioleta , Feminino , Humanos , Raios Ultravioleta/efeitos adversos , Dilatação , Procedimentos Cirúrgicos Oftalmológicos , Óculos
19.
Sci Rep ; 14(1): 6722, 2024 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-38509265

RESUMO

An emerging intervention for control of airborne-mediated pandemics and epidemics is whole-room far-UVC (200-235 nm). Laboratory studies have shown that 222-nm light inactivates airborne pathogens, potentially without harm to exposed occupants. While encouraging results have been reported in benchtop studies and in room-sized bioaerosol chambers, there is a need for quantitative studies of airborne pathogen reduction in occupied rooms. We quantified far-UVC mediated reduction of aerosolized murine norovirus (MNV) in an occupied mouse-cage cleaning room within an animal-care facility. Benchtop studies suggest that MNV is a conservative surrogate for airborne viruses such as influenza and coronavirus. Using four 222-nm fixtures installed in the ceiling, and staying well within current recommended regulatory limits, far-UVC reduced airborne infectious MNV by 99.8% (95% CI: 98.2-99.9%). Similar to previous room-sized bioaerosol chamber studies on far-UVC efficacy, these results suggest that aerosolized virus susceptibility is significantly higher in room-scale tests than in bench-scale laboratory studies. That said, as opposed to controlled laboratory studies, uncertainties in this study related to airflow patterns, virus residence time, and dose to the collected virus introduce uncertainty into the inactivation estimates. This study is the first to directly demonstrate far-UVC anti-microbial efficacy against airborne pathogens in an occupied indoor location.


Assuntos
Doenças Transmissíveis , Infecções por Coronavirus , Norovirus , Vírus , Animais , Camundongos , Raios Ultravioleta , Ambiente Controlado , Desinfecção/métodos
20.
World J Microbiol Biotechnol ; 40(4): 126, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38446232

RESUMO

Lactic acid bacteria (LAB) hold significant importance in diverse fields, including food technology, industrial biotechnology, and medicine. As basic components of starter cultures, probiotics, immunomodulators, and live vaccines, LAB cells resist a variety of stressors, including temperature fluctuations, osmotic and pH shocks, exposure to oxidants and ultraviolet radiation, substrate deprivation, mechanical damage, and more. To stay alive in these adversities, LAB employ a wide range of stress response strategies supported by various mechanisms, for example rearrangement of metabolism, expression of specialized biomolecules (e.g., chaperones and antioxidants), exopolysaccharide synthesis, and complex repair and regulatory systems. LAB can coordinate responses to various stressors using global regulators. In this review, we summarize current knowledge about stress response strategies used by LAB and consider mechanisms of response to specific stressful factors, supported by illustrative examples. In addition, we discuss technical approaches to increase the stress resistance of LAB, including pre-adaptation, genetic modification of strains, and adjustment of cultivation conditions. A critical analysis of the recent findings in this field augments comprehension of stress tolerance mechanisms in LAB, paving the way for prospective research directions with implications in fundamental and practical areas.


Assuntos
Lactobacillales , Raios Ultravioleta , Estudos Prospectivos , Antioxidantes , Biotecnologia , Lactobacillales/genética
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