Degradation behaviors of Nabumetone and its metabolite during UV/monochloramine process: Experimental and theoretical study

This study investigated degradation behaviors of a nonsteroidal anti-inflammatory drug Nabumetone (NMT) and its major metabolite 6-methoxy-2-naphthylacetic acid (MNA) in the coupling process of ultraviolet and monochloramine (UV/NH2Cl). The second-order rate constants of the contaminants reacting with reactive radicals (HO•, Cl•, Cl2•⁻, and CO3•⁻) were determined by laser flash photolysis experiments. HO• and Cl• contributed predominantly with 52.3% and 21.7% for NMT degradation and 60.8% and 22.3% for MNA degradation. The presence of chlorides retarded the degradation of NMT, while promoted the destruction of MNA, which was ascribed to the photosensitization effects of MNA under UV irradiation. Density functional theory (DFT) calculations revealed that radical adduct formation (RAF) was dominant pathway for both HO• and Cl• reacting with the contaminants, and hydrogen atom transfer (HAT) preferred to occur on side chains of NMT and MNA. NMT reacted with NO2• through single electron transfer (SET) with the second-order rate constant calculated to be 5.35 × 107 (mol/L)-1 sec-1, and the contribution of NO2• was predicted to be 13.0% of the total rate constant of NMT in pure water, which indicated that NO2• played a non-negligible role in the degradation of NMT. The acute toxicity and developmental toxicity of NMT were enhanced after UV/NH2Cl treatment, while those of MNA were alleviated. The transformation products of both NMT and MNA exhibited higher mutagenicity than their parent compounds. This study provides a deep understanding of the mechanism of radical degradation of NMT and MNA in the treatment of UV/NH2Cl.

Enhanced hepatic metabolic perturbation of polystyrene nanoplastics by UV irradiation-induced hydroxyl radical generation

The environmental behavior of and risks associated with nanoplastics (NPs) have attracted considerable attention. However, compared to pristine NPs, environmental factors such as ultraviolet (UV) irradiation that lead to changes in the toxicity of NPs have rarely been studied. We evaluated the changes in morphology and physicochemical properties of polystyrene (PS) NPs before and after UV irradiation, and compared their hepatotoxicity in mice. The results showed that UV irradiation caused particle size reduction and increased the carbonyl index (CI) and negative charge on the particle surface. UV-aged PS NPs (aPS NPs) could induce the generation of hydroxyl radicals (·OH), but also further promoted the generation of ·OH in the Fenton reaction system. Hepatic pathological damage was more severe in mice exposed to aPS NPs, accompanied by a large number of vacuoles and hepatocyte balloon-like changes and more marked perturbations in blood glucose and serum lipoprotein, alanine aminotransferase and aspartate aminotransferase levels. In addition, exposure to PS NPs and aPS NPs, especially aPS NPs, triggered oxidative stress and significantly damaged the antioxidant capacity of mice liver. Compared with PS NPs, exposure to aPS NPs increased the number of altered metabolites in hepatic and corresponding metabolic pathways, especially glutathione metabolism. Our research suggests that UV irradiation can disrupt the redox balance in organisms by promoting the production of ·OH, enhancing PS NPs-induced liver damage and metabolic disorders. This study will help us understand the health risks of NPs and to avoid underestimation of the risks of NPs in nature.

Comparing resistance of bacterial spores and fungal conidia to pulsed light and UVC radiation at a wavelength of 254 nm

Pulsed light (PL) inactivates microorganisms by UV-rich, high-irradiance and short time pulses (250 μs) of white light with wavelengths from 200 nm to 1100 nm. PL is applied for disinfection of food packaging material and food-contact equipment. Spores of seven Bacillus ssp. strains and one Geobacillus stearothermophilus strain and conidia of filamentous fungi (One strain of Aspergillus brasiliensis, A. carbonarius and Penicillium rubens) were submitted to PL (fluence from 0.23 J/cm2 to 4.0 J/cm2) and UVC (at λ = 254 nm; fluence from 0.01 J/cm2 to 3.0 J/cm2). One PL flash at 3 J/cm2 allowed at least 3 log-reduction of all tested microorganisms. The emetic B. cereus strain F4810/72 was the most resistant of the tested spore-forming bacteria. The PL fluence to 3 log-reduction (F3 PL) of its spores suspended in water was 2.9 J/cm2 and F3 UVC was 0.21 J/cm2, higher than F3 PL and F3 UVC of spores of B. pumilus SAFR-032 2.0 J/cm2 and 0.15 J/cm2, respectively), yet reported as a highly UV-resistant spore-forming bacterium. PL and UVC sensitivity of bacterial spores was correlated. Aspergillus spp. conidia suspended in water were poorly sensitive to PL. In contrast, PL inactivated Aspergillus spp. conidia spread on a dry surface more efficiently than UVC. The F2 PL of A. brasiliensis DSM1988 was 0.39 J/cm2 and F2 UVC was 0.83 J/cm2. The resistance of spore-forming bacteria to PL could be reasonably predicted from the knowledge of their UVC resistance. In contrast, the sensitivity of fungal conidia to PL must be specifically explored.

Arabidopsis ERD15 regulated by BBX24 plays a positive role in UV-B signaling

Ultraviolet-B (UV-B, 280-315 nm) is a minor component of solar radiation, but it has a major regulatory impact on plant growth and development. Solar UV-B regulates numerous aspects of plant metabolism, morphology and physiology through altering the expression of hundreds of genes. EARLY RESPONSIVE TO DEHYDRATION 15 (ERD15) is a drought-induced rapid response gene, formerly known as a negative regulator of the abscisic acid (ABA) signaling pathway. It is unclear whether ERD15 is involved in UV-B-induced photomorphogenesis. Previously, we reported that the BBX24 transcriptional factor negatively regulated UV-B signaling. In the present study, we identified that ERD15 is involved in UV-B photomorphogenesis as a positive regulator at phenotypic, physiological and molecular levels. Our results indicated that ERD15 expression is suppressed by UV-B, inhibited the elongation of Arabidopsis hypocotyls in a UV-B-dependent manner, promoted the expression of related UV-B signaling genes and increased the total antioxidant capacity of Arabidopsis under UV-B. Genetic hybridization results show that ERD15 acts downstream of BBX24, and BBX24 protein mediated the expression of ERD15 by binding to its promoter. Thus, ERD15 is a novel positive regulator of the UV-B signaling pathway, which is downstream of BBX24 and regulated by BBX24 protein to participate in UV-B photomorphogenesis.

Plasmid expression of Deinococcus radiodurans RecA confers UV-A protection to Escherichia coli with an inverse protein dose dependence, which does not exceed conspecific RecA protection

Low level expression in Escherichia coli of the RecA protein from the radiation resistant bacterium Deinococcus radiodurans protects a RecA deficient strain of E. coli from UV-A irradiation by up to ∼160% over basal UV-A resistance. The protection effect is inverse protein dose dependent: increasing the expression level of the D. radiodurans RecA (DrRecA) protein decreases the protection factor. This inverse protein dose dependence effect helps resolve previously conflicting reports of whether DrRecA expression is protective or toxic for E. coli. In contrast to the D. radiodurans protein effect, conspecific plasmid expression of E. coli RecA protein in RecA deficient E. coli is consistently protective over several protein expression levels, as well as consistently more protective to higher levels of UV-A exposure than that provided by the D. radiodurans protein. The results indicate that plasmid expression of D. radiodurans RecA can modestly enhance the UV resistance of living E. coli, but that the heterospecific protein shifts from protective to toxic as expression is increased.

Climate, litter quality and radiation duration jointly regulate the net effect of UV radiation on litter decomposition

Photodegradation via ultraviolet (UV) radiation is an important factor driving plant litter decomposition. Despite increasing attention to the role of UV photodegradation in litter decomposition, the specific impact of UV radiation on the plant litter decomposition stage within biogeochemical cycles remains unclear at regional and global scales. To clarify the variation rules of magnitude of UV effect on plant litter decomposition and their regulatory factors, we conducted a meta-analysis based on 54 published papers. Our results indicated that UV significantly promoted the mass loss of litter by facilitating decay of carbonaceous fractions and release of nitrogen and phosphorus. The promotion effect varied linearly or non-linearly with the time that litter exposed to UV, and with climatic factors. The UV effect on litter decomposition decreased first than increased on precipitation and temperature gradients, reaching its minimum in the area with a precipitation of 400-600 mm, and a temperature of 15-20 °C. This trend might be attributed to a potential equilibrium between the photofacilitation and photo-inhibition effects of UV under this condition. This variation in UV effect on precipitation gradient was in agreement with the fact that UV photodegradation effect was weakest in grassland ecosystems compared to that in forest and desert ecosystems. In addition, initial litter quality significantly influenced the magnitude of UV effect, but had no influence on the correlation between UV effect and climate gradient. Litter with lower initial nitrogen and lignin content shown a greater photodegradation effect, whereas those with higher hemicellulose and cellulose content had a greater photodegradation effect. Our study provides a comprehensive understanding of photodegradation effect on plant litter decomposition, indicates potentially substantial impacts of global enhancements of litter decomposition by UV, and highlights the necessity to quantify the contribution of photochemical minerallization pathway and microbial degradation pathway in litter decomposition.

Using UV/peracetic acid as pretreatment for subsequent bio-treatment of antibiotic-containing wastewater treatment: Mitigating microbial inhibition and antibiotic resistance genes proliferation

UV/peracetic acid (PAA) treatment presents a promising approach for antibiotic removal, but its effects on microbial community and proliferation of antibiotic resistance genes (ARGs) during the subsequent bio-treatment remain unclear. Thus, we evaluated the effects of the UV/PAA on tetracycline (TTC) degradation, followed by introduction of the treated wastewater into the bio-treatment system to monitor changes in ARG expression and biodegradability. Results demonstrated effective TTC elimination by the UV/PAA system, with carbon-centered radicals playing a significant role. Crucially, the UV/PAA system not only eliminated antibacterial activity but also inhibited potential ARG host growth, thereby minimizing the emergence and dissemination of ARGs during subsequent bio-treatment. Additionally, the UV/PAA system efficiently removed multi-antibiotic resistant bacteria and ARGs from the bio-treatment effluent, preventing ARGs from being released into the environment. Hence, we propose a multi-barrier strategy for treating antibiotic-containing wastewater, integrating UV/PAA pre-treatment and post-disinfection with bio-treatment. The inhibition of ARGs transmission by the integrated system was verified through actual soil testing, confirming its effectiveness in preventing ARGs dissemination in the surrounding natural ecosystem. Overall, the UV/PAA treatment system offers a promising solution for tackling ARGs challenges by controlling ARGs proliferation at the source and minimizing their release at the end of the treatment process.

Application of electron paramagnetic resonance spectroscopy to examine free radicals formed in indapamide and torasemide storage under UV irradiation and at the higher temperatures which appear under light exposition

Free radical formation in two diuretics: indapamide and torasemide was examined during UV irradiation and storage at higher temperatures using X-band (9.3 GHz) electron paramagnetic resonance spectroscopy (EPR). The aim of this study was to investigate the possibility of storing indapamide and torasemide under UV irradiation and at higher temperatures, which may occur during exposure to light. The diuretic samples were exposed to UVA irradiation for 15, 30 and 45 minutes, and stored at temperatures of 40 °C and 50 °C by 30 minutes. The EPR spectra were analyzed to determine the amplitudes (A), linewidths (ΔBpp), and integral intensities (I) and g factors. The concentrations of free radical (N) in the diuretic samples were also determined. The influence of microwave power on amplitudes, linewidths and the asymmetry parameter were evaluated. The result showed that the tested indapamide and torasemide samples exhibited high free radical concentrations in the range of 1018-1019 spin/g after UV irradiation and heat treatment. Therefore, due to the significant free radical formation indapamide and torasemide should not be stored under UV light and at temperatures of 40 °C and 50 °C. The complex character of free radical systems in the diuretic samples was proved as evidenced by the changes of the asymmetry parameters of the EPR lines with increasing microwave power. Fast spin-lattice relaxation processes were observed in all tested diuretic samples, regardless of the storage conditions. Electron paramagnetic resonance spectroscopy is proposed as a useful method in pharmacy to determine the appropriate storage conditions for diuretics.

Distinct induction pathways of heat shock protein 27 in human keratinocytes: Heat stimulation or capsaicin through phosphorylation of heat shock factor 1 at serine 326 and/or suppression of ΔNp63

Epidermal keratinocytes, forming the outermost layer of the human body, serve as a crucial barrier against diverse external stressors such as ultraviolet radiation. Proper keratinocyte differentiation and effective responses to external stimuli are pivotal for maintaining barrier integrity. Heat is one such stimulus that triggers the synthesis of heat shock proteins (HSPs) when cells are exposed to temperatures above 42 °C. Additionally, activation of the transient receptor potential cation channel subfamily V member 1 (TRPV1) occurs at 42 °C. Here, we explore the interplay between TRPV1 signaling and HSP induction in human keratinocytes. Both heat and capsaicin, a TRPV1 agonist, induce expression of HSP27, HSP70, and HSP90 in keratinocytes. Interestingly, pharmacological inhibition of TRPV1 attenuates heat-induced HSP27 expression, but not that of HSP70 or HSP90. Furthermore, both heat and capsaicin stimulation result in distinct phosphorylation patterns of heat shock factor 1 (HSF1), with phosphorylation at serine 326 being a common feature. Notably, genetic manipulation to mimic dephosphorylation of HSF1 at serine 326 reduces HSP27 levels. Additionally, ΔNp63, a key regulator of epidermal differentiation, negatively modulates HSP27 expression independently of HSF1 phosphorylation status. While heat stimulation has no effect on ΔNp63 expression, capsaicin reduces its levels. The precise role of TRPV1 signaling in keratinocytes warrants further investigation for a comprehensive understanding of its impact on barrier function.

Photoreactivity of polycyclic aromatic hydrocarbons (PAHs) and their mechanisms of phototoxicity against human immortalized keratinocytes (HaCaT)

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous organic compounds in the environment. They are produced by many anthropogenic sources of different origins and are known for their toxicity, carcinogenicity, and mutagenicity. Sixteen PAHs have been identified as Priority Pollutants by the US EPA, which are often associated with particulate matter, facilitating their dispersion through air and water. When human skin is exposed to PAHs, it might occur simultaneously with solar radiation, potentially leading to phototoxic effects. Phototoxic mechanisms involve the generation of singlet oxygen and reactive oxygen species, DNA damage under specific light wavelengths, and the formation of charge transfer complexes. Despite predictions of phototoxic properties for some PAHs, there remains a paucity of experimental data. This study examined the photoreactive and phototoxic properties of the 16 PAHs enlisted in the Priority Pollutants list. Examined PAHs efficiently photogenerated singlet oxygen and superoxide anion in simple solutions. Furthermore, singlet oxygen phosphorescence was detected in PAH-loaded HaCaT cells. Phototoxicity against human keratinocytes was evaluated using various assays. At 5 nM concentration, examined PAHs significantly reduced viability and mitochondrial membrane potential of HaCaT cells following the exposure to solar simulated light. Analyzed compounds induced a substantial peroxidation of cellular proteins after light treatment. The results revealed that a majority of the examined PAHs exhibited substantial reactive oxygen species photoproduction under UVA and violet-blue light, with their phototoxicity corresponding to their photoreactive properties. These findings improve our comprehension of the interactions between PAHs and human skin cells under environmental conditions, particularly when exposed to solar radiation.

Influence of UV light, ultrasound, and heat treatment on the migration of bisphenol A from polyethylene terephthalate bottle into the food simulant

This research examined the impacts of ultrasound, UV light, storage time, and temperature on the leaching of bisphenol A (BPA) from polyethylene terephthalate (PET) drinking water bottles in Turkey. The initial phase of the investigation encompassed the quantification of BPA in two distinct brands of bottled water. Samples were extracted by solid- phase extraction (SPE) and analyzed by high performance liquid chromatography with fluorescence detection (HPLC-FLD). According to the results in the first part, the highest BPA levels were found in bottled water. In the second part of the study, 10 to 30 min of ultrasound treatment increased the BPA migration with increased time in simulants. In the first and second weeks of storage at 25 °C, the effect of storage on BPA migration was below the detection limit ( Collapse

Key Words

• Bisphenol A
• Food Simulants
• HPLC-FLD
• PET bottles
• UV light
• Ultrasound

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MESH Headings

• Polyethylene Terephthalates/chemistry
• Hot Temperature
• Drinking Water/analysis
• Ultraviolet Rays
• Food Contamination/analysis
• Benzhydryl Compounds/analysis
• Food Packaging

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Grants Collapse

Affiliation(s)

Zana M Abdulazeez Department of Food Science and Quality Control, Faculty of Agricultural Engineering Sciences, University of Sulaimani, Iraq.
Fehmi Yazici Department of Food Engineering, Faculty of Engineering, Ondokuz Mayis University, Samsun, Turkey
Abdurrahman Aksoy Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Ondokuz Mayis University, Samsun, Turkey

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Bowman Layer Onlay Grafting as a Minimally Invasive Treatment for the Most Challenging Cases in Keratoconus

PURPOSE

To analyze the clinical outcomes after Bowman layer (BL) onlay grafting for the treatment of progressive, advanced keratoconus.

DESIGN

Prospective, interventional case series.

METHODS

Twenty-one eyes underwent BL onlay grafting. After removing the epithelium, a single or double BL graft was "stretched" onto the corneal surface, allowed to dry-in, and a soft bandage lens was placed until the graft was re-epithelialized. Best spectacle- and/or best contact lens-corrected visual acuity (BSCVA/BCLVA), corneal tomography, and postoperative complication rates were analyzed for the total group and 2 subgroups (group 1: preoperative maximum keratometry [Kmax] <69 diopters [D; n = 7); group 2: preoperative Kmax ≥69 D [n = 14]). Follow-up ranged from 6 to 36 months (mean 21 ± 11 months).

RESULTS

All 21 surgeries were uneventful. Overall, Kmax changed from 76 ± 12 D preoperatively to 72 ± 9 D at 6 to 36 months postoperatively (P = .015). Kmax decreased by 6 D in group 2 (P = .002) but did not change in group 1. Average BSCVA remained stable for group 1 and improved from preoperatively 0.8 ± 0.4 to 0.4 ± 0.2 logarithm of the minimum angle of resolution postoperatively in group 2 (P = .032); BCLVA remained stable (P > .05). Within the first postoperative weeks, 2 eyes required BL graft repositioning after inadvertent bandage lens removal and 4 eyes underwent BL retransplantation for incomplete re-epithelialization. One eye underwent BL regrafting 12 months postoperatively after traumatic corneal erosion. All eyes showed a completely re-epithelialized graft at the last available follow-up.

CONCLUSIONS

BL onlay grafting is a completely extraocular, minimally invasive surgical technique, providing up to -6 D of corneal flattening in eyes with advanced progressive keratoconus, allowing for continued (scleral) contact lens wear and therefore preserving the BCLVA.

Kinetics of chlorine and chloramine reactions in reverse osmosis permeate and their impact on radical formation during UV/chlorine advanced oxidation for potable reuse

Knowledge of the speciation of chlorine and chloramines in reverse osmosis (RO) permeate is needed to estimate the performance (i.e., pollutant log reduction) of subsequent UV/chlorine advanced oxidation processes (AOPs). To accurately predict the speciation, a previously reported breakpoint chlorination kinetic model was experimentally validated for pH 5.5 and reaction times < 3 min and used to predict the kinetics of breakpoint chlorination in RO permeate. The predictions showed that eliminating chloramines by adding chlorine at a dose beyond the chlorine-to-nitrogen (Cl/N) breakpoint ratio is not practical due to the high breakpoint Cl/N ratio for RO permeate (∼3.0 molar ratio) and an estimated > 40 min reaction time. The conversion from monochloramine (NH2Cl) to dichloramine (NHCl2) is the major process involved, and either or both free chlorine and chloramines may be the major species present, depending on the Cl/N ratio. Model simulations showed that increasing the oxidant dose may not always enhance the performance of UV/chlor(am)ine in RO permeate, due to the need for a low free chlorine dose for optimal •OH exposure in RO permeate. Further UV/AOPs modelling showed that it is important to control the NH2Cl concentration to improve the UV/AOP performance in RO permeate, which may be achieved by extending the reaction time after chlorine is added or increasing the applied Cl/N ratio (e.g., increasing chlorine dose). However, these measures only enhance the pollutant percentage removal by about 5 % under the conditions modelled. A simulation tool was developed and is provided to predict the speciation of chlor(am)ine in RO permeate.

Refinement of kinetic model and understanding the role of dichloride radical (Cl2•-) in radical transformation in the UV/NH2Cl process

The ultraviolet/monochloramine (UV/NH2Cl) process is an emerging advanced oxidation process with promising prospects in water treatment. Previous studies developed kinetic models of UV/NH2Cl for simulating radical concentrations and pollutant degradation. However, the reaction rate constants of Cl2•- with bicarbonate and carbonate (kCl2•-, HCO3- and kCl2•-, CO32-) were overestimated in literature. Consequently, when dosing 1 mM chloride and 1 mM bicarbonate, the current models of UV/NH2Cl severely under-predicted the experimental concentrations of three important radicals (i.e., hydroxyl radical (HO•), chlorine radical (Cl•), and dichloride radical (Cl2•-)) with great deviations (> 90 %). To investigate this issue, the transformation reactions among these three radicals in UV/NH2Cl were systematically studied. For the first time, it was found that in addition to Cl•, Cl2•- was also an important parent radical of HO• in the presence of chloride, and chloride could effectively compensate the inhibitory effect of bicarbonate on HO• generation in the system. Moreover, reactions and rate constants in current models were scrutinized from corresponding literature, and the reaction rate constants of Cl2•- with bicarbonate and carbonate (kCl2•-, HCO3- and kCl2•-, CO32-) were reevaluated to be 1.47 × 105 and 3.78 × 106 M-1s-1, respectively, by laser flash photolysis. With the newly obtained rate constants, the refined model could accurately simulate concentrations of all three radicals under different chloride and bicarbonate dosages with satisfactory deviations (< 30 %). Meanwhile, the refined model performed much better in predicting pollutant degradation and radical contribution compared with the unrefined model (with the previously estimated kCl2•-, HCO3- and kCl2•-, CO32-). The results of this study enhanced the accuracy and applicability of the kinetic model of UV/NH2Cl, and deepened the understanding of radical transformation in the process.

Experimental and theoretical insight into carbamazepine degradation by chlorine-based advanced oxidation processes: Efficiency, energy consumption, mechanism and DBPs formation

Chlorine has been widely used in different advanced oxidation processes (AOPs) for micropollutants removal. In this study, different chlorine-based AOPs, namely medium pressure (MP) UV/chlorine, low pressure (LP) UV/chlorine, and in-situ chlorination, were compared for carbamazepine (CBZ) removal efficiency, energy consumption, and disinfection by-products (DBPs) formation. All three processes could achieve nearly 100% CBZ removal, while the reaction time needed by in-situ chlorination was double the time required by UV/chlorine processes. The energy consumed per magnitude of CBZ removed (EE/O) of MP UV/chlorine was 13 times higher than that of LP UV/chlorine, and relative to that of in-situ chlorination process. Accordingly, MP and LP UV/chlorine processes generated one to two orders of magnitude more hydroxyl radicals (•OH) and reactive chlorine species (RCS) than in-situ chlorination. Besides, RCS were the dominant reactive species, contributing to 78.3%, 75.6%, and 71.6% of CBZ removal in MP, LP UV/chlorine, and in-situ chlorination, respectively. According to the Gibbs free energy barriers between CBZ and RCS/•OH calculated based on density functional theory (DFT), RCS had more reaction routes with CBZ and showed lower energy barrier in the main CBZ degradation pathways like epoxidation and formation of iminostilbene. When applied to secondary wastewater effluent, UV/chlorine and in-situ chlorination produced overall DBPs ranging from 104.77 to 135.41 µg/L. However, the production of chlorate during UV/chlorine processes was 15 times higher than that during in-situ chlorination.

Updates for Reptile Pediatric Medicine

The health of hatchling, juvenile, and young adult reptiles continues to be plagued by historic nutritional deficiencies, old and emerging infectious diseases, and more recent phenotype-selective congenital abnormalities that impact welfare. Knowledge of mating seasonality, average egg counts, gestation times, and age and/or size for sexual maturity is necessary to help guide best practices for care of pediatric reptiles. Calcium, vitamin D3, and ultraviolet B (UVB) lighting recommendations vary in effectiveness amongst different species and can change with age. Phenotype-selective color patterns for spider ball pythons and scalation pattern for bearded dragons have resulted in vestibular disease, and increased evaporative water loss, respectively. Salmonellosis remains the most reported zoonotic disease for captive reptiles in the United States, despite improvements in client education and improvements in captive reptile husbandry.

Quantitation of total vitamin D2 and D4 in UV-exposed mushrooms using HPLC with UV detection after novel two-step solid phase extraction

A robust method for quantitation of total vitamin D2 and D4 in mushrooms by high performance liquid chromatography with UV detection (HPLC-UV) was developed to analyze mushrooms exposed to UV light. A two-step solid phase extraction (SPE) (silica, carbon black) removed chromatographic interferences typically resolved only with mass spectrometric detection (LC-MS) and allowed quantitation of all vitamin D and pre-D analytes. The vitamin and pre-vitamin forms of D2, D4 and D3 (internal standard), as well as other photoisomers and sterols were resolved. Results for six types of UV-exposed mushrooms were comparable to LC-MS. Screening of ten additional types of UV-exposed mushrooms without the IS confirmed lack of interference with the IS. The limit of quantification (µg/100 g fresh weight) was 0.4 for vitamin D and 0.9 for pre-vitamin D. Mushrooms do not have to be dried, and separatory funnels and large solvent volumes were also eliminated from sample preparation.

Unravelling the neglected role of ultraviolet radiation on stomata: A meta-analysis with implications for modelling ecosystem-climate interactions

Stomata play a pivotal role in regulating gas exchange between plants and the atmosphere controlling water and carbon cycles. Accordingly, we investigated the impact of ultraviolet-B radiation, a neglected environmental factor varying with ongoing global change, on stomatal morphology and function by a Comprehensive Meta-Analysis. The overall UV effect at the leaf level is to decrease stomatal conductance, stomatal aperture and stomatal size, although stomatal density was increased. The significant decline in stomatal conductance is marked (6% in trees and >10% in grasses and herbs) in short-term experiments, with more modest decreases noted in long-term UV studies. Short-term experiments in growth chambers are not representative of long-term field UV effects on stomatal conductance. Important consequences of altered stomatal function are hypothesized. In the short term, UV-mediated stomatal closure may reduce carbon uptake but also water loss through transpiration, thereby alleviating deleterious effects of drought. However, in the long term, complex changes in stomatal aperture, size, and density may reduce the carbon sequestration capacity of plants and increase vegetation and land surface temperatures, potentially exacerbating negative effects of drought and/or heatwaves. Therefore, the expected future strength of carbon sink capacity in high-UV regions is likely overestimated.

The combined effects of azoxystrobin and different aged polyethylene microplastics on earthworms (Eisenia fetida): A systematic evaluation based on oxidative damage and intestinal function

Pesticides and microplastics are common pollutants in soil environments, adversely affecting soil organisms. However, the combined toxicological effects of aged microplastics and pesticides on soil organisms are still unclear. In this study, we systematically studied the toxicological effects of azoxystrobin and four different aged polyethylene (PE) microplastics on earthworms (Eisenia fetida). The purpose was to evaluate the effects of aging microplastics on the toxicity of microplastics-pesticides combinations on earthworms. The results showed that different-aged PE microplastics promoted azoxystrobin accumulation in earthworms. Meanwhile, combined exposure to azoxystrobin and aged PE microplastics decreased the body weight of earthworms. Besides, both single and combined exposure to azoxystrobin and aged PE microplastics could lead to oxidative damage in earthworms. Further studies revealed that azoxystrobin and aged PE microplastics damage the intestinal structure and function of earthworms. Additionally, the combination of different aged PE microplastics and azoxystrobin was more toxic on earthworms than single exposures. The PE microplastics subjected to mechanical wear, ultraviolet radiation, and acid aging exhibited the strongest toxicity enhancement effects on earthworms. This high toxicity may be related to the modification of PE microplastics caused by aging. In summary, these results demonstrated the enhancing effects of aged PE microplastics on the toxicity of pesticides to earthworms. More importantly, aged PE microplastics exhibited stronger toxicity-enhancing effects in the early exposure stages. This study provides important data supporting the impact of different aged PE microplastics on the environmental risks of pesticides.

Low UV radiation influenced DNA methylation, gene regulation, cell proliferation, viability, and biochemical differentiation in the cell suspension cultures of Cannabis indica

The effect of low artificial Ultraviolet (UV) on the DNA methylation remains controversial. This study addresses how differential photoperiods of UV radiation affect the biochemical and molecular behaviors of Cannabis indica cell suspension cultures. The cell suspensions were illuminated with the compact fluorescent lamps (CFL), emitting a combination of 10% UVB, 30% UVA, and the rest visible wavelengths for 0, 4, 8, and 16 h. The applied photoperiods influenced cell morphological characteristics. The 4 h photoperiod was the most effective treatment for improving biomass, growth index and cell viability percentage while these indices remained non-significant in the 16 h treatment. The methylation-sensitive amplified polymorphism (MASP) assay revealed that the UV radiation was epigenetically accompanied by DNA hypermethylation. The light-treated cells significantly displayed higher relative expression of the cannabidiolic‌ acid synthase (CBDAS) and delta9-tetrahydrocannabinolic acid synthase (THCAS) genes about 4-fold. The expression of the olivetolic acid cyclase (OAC) and olivetol synthase (OLS) genes exhibited an upward trend in response to the UV radiation. The light treatments also enhanced the proline content and protein concentration. The 4 h illumination was significantly capable of improving the cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC) concentrations, in contrast with 16 h. By increasing the illumination exposure time, the activity of the phenylalanine ammonia-lyase (PAL) enzyme linearly upregulated. The highest amounts of the phenylpropanoid derivatives were observed in the cells cultured under the radiation for 4 h. Taken collective, artificial UV radiation can induce DNA methylation modifications and impact biochemical and molecular differentiation in the cell suspensions in a photoperiod-dependent manner.

Human CST complex restricts excessive PrimPol repriming upon UV induced replication stress by suppressing p21

DNA replication stress, caused by various endogenous and exogenous agents, halt or stall DNA replication progression. Cells have developed diverse mechanisms to tolerate and overcome replication stress, enabling them to continue replication. One effective strategy to overcome stalled replication involves skipping the DNA lesion using a specialized polymerase known as PrimPol, which reinitiates DNA synthesis downstream of the damage. However, the mechanism regulating PrimPol repriming is largely unclear. In this study, we observe that knockdown of STN1 or CTC1, components of the CTC1/STN1/TEN1 complex, leads to enhanced replication progression following UV exposure. We find that such increased replication is dependent on PrimPol, and PrimPol recruitment to stalled forks increases upon CST depletion. Moreover, we find that p21 is upregulated in STN1-depleted cells in a p53-independent manner, and p21 depletion restores normal replication rates caused by STN1 deficiency. We identify that p21 interacts with PrimPol, and STN1 depletion stimulates p21-PrimPol interaction and facilitates PrimPol recruitment to stalled forks. Our findings reveal a previously undescribed interplay between CST, PrimPol and p21 in promoting repriming in response to stalled replication, and shed light on the regulation of PrimPol repriming at stalled forks.

Improved microalgae growth and lipid production in anaerobic digestate with ultraviolet radiation pretreatment

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.

Disinfection by-products control in wastewater effluents treated with ozone and biological activated carbon followed by UV/Chlor(am)ine processes

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.

Selective enhancement of (6-4) photoproduct formation in dithymine dinucleotides driven by specific sugar puckering

Four dinucleotide analogs of thymidylyl(3'-5')thymidine (TpT) have been designed and synthesized with a view to increase the selectivity, with respect to CPD, of efficient UV-induced (6-4) photoproduct formation. The deoxyribose residues of these analogs have been modified to increase north and south conformer populations at 5'- and 3'-ends, respectively. Dinucleotides whose 5'-end north population exceeds ca. 60% and whose 3'-end population is almost completely south display a three-fold selective enhancement in (6-4) adduct production when exposed to UV radiation, compared to TpT. These experimental results undoubtedly provide robust foundations for studying the singular ground-state proreactive species involved in the (6-4) photoproduct formation mechanism.

Shedding light on the problem: Influence of the radiator power, source-sample distance, and exposure time on the performance of UV-C lamps in laboratory and real-world conditions

Effective surface disinfection is crucial for preventing the spread of pathogens in hospitals. Standard UltraViolet-C (UV-C) lamps have been widely used for this purpose, but their disinfection efficiency under real-world conditions is not well understood. To fill this gap, the influence of the power of the ultraviolet radiator, source-sample distance, and exposure time on the performance of UV-C lamps against Escherichia coli and Staphylococcus epidermidis were experimentally determined in the laboratory and hospital. The obtained results showed that the UV irradiance and, thus, the UV-C disinfection efficiency decreased significantly at distances greater than 100 cm from the UV-C lamp. Moreover, increasing the total power of the radiators does not improve the performance of UV-C lamps under real conditions. The UV-C disinfection efficiency greater than 90% was achieved only under laboratory conditions at a close distance from the UV-C lamp, i.e., 10 cm. These findings provide novel insights into the limitations of UV-C lamps in real-world conditions and highlight the need for more effective disinfection strategies in hospitals.

Ultraviolet irradiation as alternative non-thermal cold pasteurization to improve quality and microbiological parameters of mango juice during cold storage

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.

How data on transformation products can support the redesign of sulfonamides towards better biodegradability in the environment

Sulfonamide antibiotics (SUAs) released into the environment can affect environmental und human health, e.g., by accelerating the development and selection of antimicrobial resistant bacteria. Benign by Design (BbD) of SUAs is an effective risk prevention approach. BbD principles aim for fast and complete mineralization or at least deactivation of the SUA after release into the aquatic environment. Main objective was to test if mixtures of transformation products (TPs) generated via photolysis of SUAs can be used as an efficient way to screen for similarly effective but better biodegradable SUA alternatives. Six SUAs were photolyzed (Hg ultraviolet (UV) light), and generated UV-mixtures analysed by high performance liquid chromatography coupled to an UV and tandem mass spectrometry detector. UV-mixtures were screened for antibiotic activity (luminescence bacteria test, LBT, on luminescence and growth inhibition of Aliivibrio Fischeri) and environmental biodegradability (manometric respirometry test, MRT, OECD 301F) using untreated parent SUAs in comparison. Additionally, ready environmental biodegradability of three commercially available hydroxylated sulfanilamide derivatives was investigated. SUA-TPs contributed to acute and chronic bacterial luminescence inhibition by UV-mixtures. LBT's third endpoint, growth inhibition, was not significant for UV-mixtures. However, it cannot be excluded for tested TPs as concentrations were lower than parents' concentrations and inhibition by most parental concentrations tested was also not significant. HPLC analysis of MRT samples revealed that one third of SUA-TPs was reduced during incubation. Three of these TPs, likely OH-SIX, OH-SMX and OH-STZ, were of interest for BbD because the sulfonamide moiety is still present. However, hydroxylated sulfanilamide derivatives, tested to investigate the effect of hydroxylation on biodegradability, were not readily biodegraded. Thus, improving mineralization through hydroxylation as a general rule couldn't be confirmed, and no BbD candidate could be identified. This study fills data gaps on bioactivity and environmental biodegradability of SUAs' TP-mixtures. Findings may support new redesign approaches.

Uncovering the impact of UV radiation on mitochondria in dermal cells: a STED nanoscopy study

Mitochondria are essential organelles in cellular energy metabolism and other cellular functions. Mitochondrial dysfunction is closely linked to cellular damage and can potentially contribute to the aging process. The purpose of this study was to investigate the subcellular structure of mitochondria and their activities in various cellular environments using super-resolution stimulated emission depletion (STED) nanoscopy. We examined the morphological dispersion of mitochondria below the diffraction limit in sub-cultured human primary skin fibroblasts and mouse skin tissues. Confocal microscopy provides only the overall morphology of the mitochondrial membrane and an indiscerptible location of nucleoids within the diffraction limit. Conversely, super-resolution STED nanoscopy allowed us to resolve the nanoscale distribution of translocase clusters on the mitochondrial outer membrane and accurately quantify the number of nucleoids per cell in each sample. Comparable results were obtained by analyzing the translocase distribution in the mouse tissues. Furthermore, we precisely and quantitatively analyzed biomolecular distribution in nucleoids, such as the mitochondrial transcription factor A (TFAM), using STED nanoscopy. Our findings highlight the efficacy of super-resolution fluorescence imaging in quantifying aging-related changes on the mitochondrial sub-structure in cells and tissues.

Removal of tetracycline by ultraviolet/sodium percarbonate (UV/SPC)advanced oxidation process in water

Tetracycline (TC) was widely used and frequently detected in various water bodies, where the presence of TC posed a significant threat to the health of aquatic organisms. Furthermore, antibiotics were hardly degraded by biological treatment. Thus, in order to enhance the removal of TC, we proposed the use of a novel ultraviolet/sodium percarbonate (UV/SPC) advanced oxidation process and initiated an in-depth study. The study investigated the influence of oxidant dosage, initial pH, UV intensity, and TC concentration on the removal of TC. The results demonstrated that the UV/SPC system efficiently removed TC, with removal efficiency increasing as the SPC concentration increased. Within the pH range of 3-11, TC degradation exhibited minimal variation, indicating the UV/SPC system's strong adaptability to pH variations. The research on the impact of the water matrix on TC removal revealed that HCO3- had an inhibitory effect on TC degradation, while NO3- promoted TC degradation. Additionally, the presence of free radical species (·OH, ·CO3-, ·O2-) were detected and rate constants for the secondary reactions (k·OH,TC = 6.3 × 109 L mol-1·s-1, k·CO3-,TC = 3.4 × 108 L mol-1·s-1) were calculated, indicating that ·OH exhibited a stronger oxidative performance compared to ·CO3-. This study did not only present a novel strategy via UV/SPC to remove TC but also uncovered the unique role of ·CO3- for contaminant removal.

Fenton-like system of UV/Glucose-oxidase@Kaolin coupled with organic green rust: UV-enhanced enzyme activity and the mechanism of UV synergistic degradation of photosensitive pollutants

This study introduces the UV/glucose-oxidase@Kaolin (GOD@Kaolin) coupled organic green rust (OGR) system (UV/OGR/GOD@Kaolin) to investigate the promotion of glucose oxidase activity by UV light and its synergistic degradation mechanism for photosensitive pollutants, specifically targeting the efficient degradation of 4-chlorophenol (4-CP). The enzyme system demonstrates its ability to overcome drawbacks associated with traditional Fenton systems, including a narrow pH range and high localized concentration of H2O2, by gradually releasing hydrogen peroxide in situ within a neutral environment. In the presence of UV radiation under specific conditions, enhanced enzyme activity is observed, resulting in increased efficiency in pollutant removal. The gradual release of hydrogen peroxide plays a crucial role in preventing unwanted reactions among active substances. These unique features facilitate the generation of highly reactive species, such as Fe(IV)O, •OH, and •O2-, tailored to efficiently target the organic components of interest. Additionally, the system establishes a positive iron cycle, ensuring a sustained reactive capability throughout the degradation process. The results highlight the UV/OGR/GOD@Kaolin system as an effective and environmentally friendly approach for the degradation of 4-CP, and the resilience of the enzyme extends the system's applicability to a broader range of scenarios.

Photocatalytic degradation process of antibiotic sulfamethoxazole by ZnO in aquatic systems: a dynamic kinetic model based on contributions of OH radical, oxygenated radical intermediates and dissolved oxygen

The photocatalytic degradation process of sulfamethoxazole (SMX) using ZnO in aquatic systems has been systematically studied by varying initial SMX concentration from 0 to 15 mgL-1, ZnO dosage from 0 to 4 gL-1 and UV light intensity at the light source from 0 to 18 W(m-lamp length)-1 at natural pH. Almost complete degradations of SMX were achieved within 120 min for the initial SMX concentration ≤15 mgL-1 with ZnO dosage of 3 gL-1 and UV light intensity of 18 W(m-lamp length)-1. The photocatalytic degradation process was found to be interacted with the dissolved oxygen (DO) consumption. With oxygen supply through the gas-liquid free-surface, the DO concentration decreased significantly in the initial SMX degradation phase and increased asymptotically to the saturated DO concentration after achieving about 80% SMX degradation. The change in DO concentration was probably controlled by the oxygen consumption in the formation of oxygenated radical intermediates. A novel dynamic kinetic model based on the fundamental reactions of photocatalysis and the formation of oxygenated radical intermediates was developed. In the modeling the dynamic concentration profiles of OH radical and DO are considered. The dynamics of SMX degradation process by ZnO was simulated reasonably by the proposed model.

Proportion of cancer cases and deaths attributable to potentially modifiable risk factors in Peru

BACKGROUND

Limited evidence exists on the population attributable fraction (PAF) of cancer cases and deaths in Latin America. In Peru several studies have been published regarding the PAF of various risk factors and their associated diseases. The objective of this study was to estimate the fraction of cancer cases and deaths attributable to potentially modifiable risk factors in Peru in 2018, before the COVID-19 pandemic in the population of 15 years old and older.

METHODS

An ecological study was conducted using the prevalence of exposure of the Peruvian population to modifiable risk factors for cancer, the relative risk associated with each factor, and the number of cancer cases and deaths in 2018 as inputs. We used the Parkin formula with a Montecarlo statistical simulation model to calculate the PAF and confidence intervals. The number of new cancer cases and deaths attributed to each risk factor was determined by multiplying the number of cases and deaths in each gender by the PAF of each risk factor.

FINDINGS

In Peru, 38.5% of new cases (34.5% in men and 42% in women) and 43.4% of cancer-related deaths (43.4% in men and 43.4% in women) were attributable to modifiable risk factors. The number of cancers attributable was 25,308 (10,439 in men and 14,869 in women) and the number of deaths attributable to cancer was 14,839 (6,953 in men and 7,886 in women). The predominant modifiable risk factors contributing to the highest number of cases and deaths were HPV infection (4,563 cases, 2,409 deaths), current tobacco use (3,348 cases, 2,180 deaths), and helicobacter pylori infection (2,677 cases, 1,873 deaths). Among the risk factors, oncogenic infections constituted the group with the highest PAF (16.6% for cases, 19.2% for deaths) followed by other unhealthy lifestyle factors (14.2% for cases, 16.7% for deaths), tobacco (7.2% for cases, 7.2% for deaths) and ultraviolet radiation (0.5% for cases, 0.3% for deaths).

CONCLUSIONS

Prior to the COVID-19 pandemic, 38.5% of cancer cases and 43.4% of cancer-related deaths in Peru were linked to modifiable risk factors in the population of 15 years old and older. Most preventable cancer cases and deaths were related to oncogenic infections, primarily caused by HPV and helicobacter pylori, followed by tobacco and obesity.

X-ray-activated polymerization expanding the frontiers of deep-tissue hydrogel formation

Photo-crosslinking polymerization stands as a fundamental pillar in the domains of chemistry, biology, and medicine. Yet, prevailing strategies heavily rely on ultraviolet/visible (UV/Vis) light to elicit in situ crosslinking. The inherent perils associated with UV radiation, namely the potential for DNA damage, coupled with the limited depth of tissue penetration exhibited by UV/Vis light, severely restrict the scope of photo-crosslinking within living organisms. Although near-infrared light has been explored as an external excitation source, enabling partial mitigation of these constraints, its penetration depth remains insufficient, particularly within bone tissues. In this study, we introduce an approach employing X-ray activation for deep-tissue hydrogel formation, surpassing all previous boundaries. Our approach harnesses a low-dose X-ray-activated persistent luminescent phosphor, triggering on demand in situ photo-crosslinking reactions and enabling the formation of hydrogels in male rats. A breakthrough of our method lies in its capability to penetrate deep even within thick bovine bone, demonstrating unmatched potential for bone penetration. By extending the reach of hydrogel formation within such formidable depths, our study represents an advancement in the field. This application of X-ray-activated polymerization enables precise and safe deep-tissue photo-crosslinking hydrogel formation, with profound implications for a multitude of disciplines.

Spectral sensitivity of click beetles (Coleoptera: Elateridae) and their responses to light stimuli in laboratory and field experiments

With increasingly fewer insecticides registered to control the larvae of pest click beetles (Coleoptera: Elateridae), integrative beetle management, including pheromone- and light-based trapping of adult beetles, must be explored as an alternative strategy. Here, we analyzed the spectral sensitivity and color preference of 9 elaterids across 6 genera in electrophysiological recordings and in behavioral bioassays. In electroretinogram recordings (ERGs), dark-adapted beetles were exposed to narrow wavebands of light in 10-nm increments from 330 to 650 nm. All beetles proved most sensitive to green (515-538 nm) and ultraviolet (UV) light (~360 nm). In 4-choice bioassay arenas with 3 light emitting diodes (LEDs; green [525 nm], blue [470 nm], red [655 nm]) and a dark control as test stimuli, beetles discriminated between test stimuli, being preferentially attracted to green and blue LEDs. In field experiments, Vernon pitfall traps fitted with a green, blue or white LED captured significantly more male and female Agriotes lineatus and A. obscurus than dark control traps. When traps were baited with green or blue LEDs at light intensities that differed by 10-fold, the traps baited with higher light intensity lures captured numerically more beetles but trap catch data in accordance with light intensity did not differ statistically. Light-based trapping may be a viable tool for monitoring elaterid species known not to have pheromones.

Kinetic Model for Predicting Perfluoroalkyl Acid Degradation During UV-Sulfite Treatment

Hydrated electron (eaq-) treatment processes show great potential in remediating recalcitrant water contaminants, including perfluoroalkyl and polyfluoroalkyl substances (PFAS). However, treatment efficacy depends upon many factors relating to source water composition, UV light source characteristics, and contaminant reactivity. Here, we provide critical insights into the complex roles of solution parameters on contaminant abatement through application of a UV-sulfite kinetic model that incorporates first-principles information on eaq- photogeneration and reactivity. The model accurately predicts decay profiles of short-chain perfluoroalkyl acids (PFAAs) during UV-sulfite treatment and facilitates quantitative interpretation of the effects of changing solution composition on PFAS degradation rates. Model results also confirm that the enhanced degradation of PFAAs observed under highly alkaline pH conditions results from changes in speciation of nontarget eaq- scavengers. Reverse application of the model to UV-sulfite data collected for longer chain PFAAs enabled estimation of bimolecular rate constants (k2, M-1 s-1), providing an alternative to laser flash photolysis (LFP) measurements that are not feasible due to the water solubility limitations of these compounds. The proposed model links the disparate means of investigating eaq- processes, namely, UV photolysis and LFP, and provides a framework to estimate UV-sulfite treatment efficacy of PFAS in diverse water sources.

Intensified degradation of tartrazine dye present in effluent using ultrasound combined with ultraviolet irradiation and oxidants

Effluent containing tartrazine can affect the environment and human health significantly prompting the current study into degradation using a sonochemical reactor operated individually and combined with advanced oxidation processes. The optimum conditions for ultrasound treatment were established as dye concentration of 10 ppm, pH of 3, temperature as 35 °C, and power as 90 W. The combination approach of H2O2/UV, H2O2/US, and H2O2/UV/US resulted in higher degradation of 25.44%, 57.4%, and 74.36% respectively. Use of ZnO/UV/US approach increased the degradation significantly to 85.31% whereas maximum degradation as 93.11% was obtained for the US/UV/Fenton combination. COD reduction was found maximum as 83.78% for the US/UV/Fenton combination. The kinetic analysis showed that tartrazine dye degradation follows pseudo first-order kinetics for all the studied processes. Combination of Fenton with UV and US was elucidated as the best approach for degradation of tartrazine.

Hazards associated with blue light emitted during gas metal arc welding of mild steel using various shielding gases and currents

Blue light emitted during arc welding is known to potentially cause photoretinopathy. To help prevent retinal injury, it is important to identify the hazards associated with various welding conditions. The present work conducted experiments involving gas metal arc welding of mild steel under various conditions, and measured the spectral radiance of the arcs. The effective radiance values, as used by the American Conference of Governmental Industrial Hygienists (ACGIH) to quantify exposure level of blue light, were subsequently calculated from the data. The resulting values were in the range of 5.0-118 W/cm2/sr, corresponding to hazardous levels according to ACGIH guidelines. The effective radiance was increased at higher welding currents and when pulsed currents were used rather than steady currents. The blue light hazard was also affected by the type of shielding gas employed. These data confirm that it is very hazardous to stare at arcs during gas metal arc welding of mild steel. As such, appropriate eye protection is necessary during arc welding, and directly staring at the arc should be avoided.

Additional HONO and OH Generation from Photoexcited Phenyl Organic Nitrates in the Photoreaction of Aromatics and NOx

HONO acts as a major OH source, playing a vital role in secondary pollutant formation to deteriorate regional air quality. Strong unknown sources of daytime HONO have been widely reported, which significantly limit our understanding of radical cycling and atmospheric oxidation capacity. Here, we identify a potential daytime HONO and OH source originating from photoexcited phenyl organic nitrates formed during the photoreaction of aromatics and NOx. Significant HONO (1.56-4.52 ppb) and OH production is observed during the photoreaction of different kinds of aromatics with NOx (18.1-242.3 ppb). We propose an additional mechanism involving photoexcited phenyl organic nitrates (RONO2) reacting with water vapor to account for the higher levels of measured HONO and OH than the model prediction. The proposed HONO formation mechanism was evidenced directly by photolysis experiments using typical RONO2 under UV irradiation conditions, during which HONO formation was enhanced by relative humidity. The 0-D box model incorporated in this mechanism accurately reproduced the evolution of HONO and aromatic. The proposed mechanism contributes 5.9-36.6% of HONO formation as the NOx concentration increased in the photoreaction of aromatics and NOx. Our study implies that photoexcited phenyl organic nitrates are an important source of atmospheric HONO and OH that contributes significantly to atmospheric oxidation capacity.

Photo-neuro-immuno-endocrinology: How the ultraviolet radiation regulates the body, brain, and immune system

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.

Far-UVC Photolysis of Peroxydisulfate for Micropollutant Degradation in Water

Increasing radical yields to reduce UV fluence requirement for achieving targeted removal of micropollutants in water would make UV-based advanced oxidation processes (AOPs) less energy demanding in the context of United Nations' Sustainable Development Goals and carbon neutrality. We herein demonstrate that, by switching the UV radiation source from conventional low-pressure UV at 254 nm (UV254) to emerging Far-UVC at 222 nm (UV222), the fluence-based concentration of HO• in the UV/peroxydisulfate (UV/PDS) AOP increases by 6.40, 2.89, and 6.00 times in deionized water, tap water, and surface water, respectively, with increases in the fluence-based concentration of SO4•- also by 5.06, 5.81, and 55.47 times, respectively. The enhancement to radical generation is confirmed using a kinetic model. The pseudo-first-order degradation rate constants of 16 micropollutants by the UV222/PDS AOP in surface water are predicted to be 1.94-13.71 times higher than those by the UV254/PDS AOP. Among the tested water matrix components, chloride and nitrate decrease SO4•- but increase HO• concentration in the UV222/PDS AOP. Compared to the UV254/PDS AOP, the UV222/PDS AOP decreases the formation potentials of carbonaceous disinfection byproducts (DBPs) but increases the formation potentials of nitrogenous DBPs.

The aggregation characteristics of Aspergillus spores under various conditions and the impact on LPUV inactivation: Comparisons with chlorine-based disinfection

Aggregation is the primary step prior to fungal biofilm development. Understanding the attributes of aggregation is of great significance to better control the emergence of waterborne fungi. In this study, the aggregation of Aspergills spores (A. flavus and A. fumigatus) under various salt, culture medium, and humic acid (HA) conditions was investigated for the first time, and the inactivation via low-pressure ultraviolet (LPUV) upon aggregated Aspergillus spores was also presented. The aggregation efficiency and size of aggregates increased over time and at low salt (NaCl and CaCl2) concentration (10 mM) while decreasing with the continuous increase of salt concentration (100 and 200 mM). Increasing the concentration of culture medium and HA promoted the aggregation of fungal spores. Spores became hydrated, swelled, and secreted more viscous substances during the growth period, which accelerated the aggregation process. Results also suggested that fungal spores aggregated more easily in actual water, posing a high risk of biohazard in real-life scenarios. Inactivation efficiency by LPUV decreased with higher aggregation degrees due to the protection from the damaged spores on the outer layer and the shielding of pigments in the cell wall. Compared to chlorine-based disinfection, the aggregation resulted in the extension of shoulder length yet neglectable change of inactivation rate constant under LPUV treatment. Further investigation of cell membrane integrity and intracellular reactive oxygen species was conducted to elucidate the difference in mechanisms between various techniques. This study provides insight into the understanding and controlling of the aggregation of fungal spores.

Central Toxic Keratopathy After Collagen Cross-Linking: A Case Series

PURPOSE

The aim of this study was to report a case series of central toxic keratopathy (CTK) after collagen cross-linking (CXL) in keratoconus.

METHODS

This is a retrospective case series between January 2020 and September 2021. In this period, CXL was performed for progressive keratoconus in 964 eyes. CXL was performed using the epithelium-off accelerated protocol in all patients with a riboflavin soak time of 20 minutes and a UVA light exposure of 9 mW for 10 minutes using the Avedro KXL (Glaukos Inc, Aliso Viejo, CA) cross-linking system.

RESULTS

Twelve of 964 eyes (1.2%) developed CTK within 1 week of CXL. All patients presented with well-circumscribed, central disciform haze that was broader in the anterior stroma and narrower in the posterior stroma. We noted initial flattening in keratometry up to 3 months post-CXL in these patients, which gradually steepened over 12 months, but did not reach preoperative levels. We also noted exuberant flattening in pachymetry in the first 3 months, which improved over 12 months. There was a statistically significant decrease in pachymetry in patients who developed CTK at 3 and 12 months postoperatively when compared to patients who underwent CXL but did not develop CTK.

CONCLUSIONS

Several reports of CTK postrefractive surgery have been described previously. However, the association of CXL in the development of CTK has not been described previously. Here, we elucidated the clinical features of CTK after CXL and how it differs from corneal scarring or haze that occurs post-CXL.

Microwave-assisted UV digestion of starch and skimmed milk powder: Environmentally friendly protocol for essential and toxic elements determination

The present work evaluated a microwave-assisted wet digestion method using diluted HNO3 with in situ UV radiation for the digestion of starch and skimmed milk powder for further metals determination by spectrometric plasma-based techniques. The sample digestion was conducted using an in situ UV lamp (electrodeless discharge lamp), and the digestion efficiency was improved by employing O2 (20 bar) and 2 mL 30 % H2O2 as auxiliary reagents. The accuracy of the proposed digestion method was evaluated by metals determination (Ca, Cd, Cu, Fe, K, Mg, Mo, Mn, Na, Pb, and Zn) in certificated reference material, which agreed with certified values (Student t-test <0,05). With the use of a UV lamp an environmentally friendly protocol was developed for starch and skimmed milk powder digestion using 0.1 mol L-1 HNO3 with auxiliary reagents (H2O2 or O2). The RCC value ranged from 0.9 to 1.2 % (starch and skimmed milk powder, respectively). The simultaneous cooling approach further improved the digestion efficiency (RCC <0,3 % for both samples), allowing to use milder digestion conditions, or even just water, being environmentally friendly, reducing the waste generation and reagents consumption, allowing food quality control through a greener approach.

Incidence of ocular surface squamous neoplasia in pterygium specimens

OBJECTIVE

Pterygium and ocular surface squamous neoplasia (OSSN) have been recognized as likely related conditions and share similar risk factors such as ultraviolet radiation and chronic inflammation. The purpose of this study is to review the incidence of OSSN in pathology specimens sent as pterygium at a single tertiary centre between 2010 and 2022.

METHODS

This is a retrospective chart review of patients operated on for pterygium between 2010 and 2022 at the University of Montreal Health Centre. Data collected include baseline demographics, results of pathology specimen, and clinical information for cases diagnosed as OSSN on pathology.

RESULTS

A total of 1559 patients were operated on for a clinical diagnosis of pterygium between 2010 and 2022, of which 854 patients (55%) were male. A total of 1142 specimens had available pathology reports, and most of the specimens were consistent with pterygium on pathology (1105 of 1142; 97%). There was an unexpected finding of 3 cases of OSSN (3 of 1142; 0.3%). Other diagnosis besides pterygium were seen in 3% of specimens (34 of 1142), including nevus (n = 12), spheroidal degeneration (n = 3), pyogenic granuloma (n = 3), and lymphangiectasia (n = 2). The 3 cases of OSSN included an 81-year-old male of French-Canadian background, a 52-year-old male of South Asian background, and a 59-year-old female of French-Canadian background. The pathology was diagnosed as conjunctival intraepithelial neoplasia (CIN) grade 3, CIN grade 2, and CIN grade 2, respectively.

CONCLUSION

The finding of OSSN in pterygium is rare in our population but can be clinically difficult to distinguish. It is important to send all pterygium specimens for pathology.

Dynamic responses of Fusarium mangiferae to ultra-violet radiation

The repair capacity of ultra-violet (UV) light DNA damage is important for adaptation of fungi to different ecological niches. We previously showed that in the soil-borne pathogen Fusarium oxysporum photo-reactivation dependent UV repair is induced at the germling stage and reduced at the filament stage. Here, we tested the developmental control of the transcription of photolyase, UV survival, UV repair capacity, and UV induced mutagenesis in the foliar pathogen Fusarium mangiferae. Unlike F. oxysporum, neither did we observe developmental control over photo-reactivation dependent repair nor the changes in gene expression of photolyase throughout the experiment. Similarly, photo-reactivation assisted reduction in UV induced mutagenesis was similar throughout the development of F. mangiferae but fluctuated during the development of F. oxysporum. To generate hypotheses regarding the recovery of F. mangiferae after UV exposure, an RNAseq analysis was performed after irradiation at different timepoints. The most striking effect of UV on F. mangiferae was developmental-dependent induction of translation related genes. We further report a complex response that changes during recovery time and involves translation, cell cycle and lipid biology related genes.

Degrading surface-water-based natural organic matter and mitigating haloacetonitrile formation during chlorination: Comparison of UV/persulfate and UV/hydrogen peroxide pre-treatments

Haloacetonitriles (HANs) are unregulated disinfection by-products that are more toxic than regulated species. Therefore, efficient decomposition of HAN precursors prior to disinfection is crucial for allaying the potential HAN-induced health risks. This study investigated the key roles of ultraviolet-activated persulfate (UV/PS) treatment in alleviating HAN formation. The effects of UV/PS treatment were evaluated by correlating with the characteristics of organic matter in surface water and comparing with conventional UV/H2O2 treatment. Upon irradiating raw water samples and a Suwannee River humic acid solution spiked with 10 mM PS or H2O2 with 254 nm UV light, UV/PS treatment was found to be more potent than UV/H2O2 in mitigating the HAN production and degrading organic substances; moreover, UV/PS treatment effectively decreased the dissolved organic nitrogen (DON) content. In contrast, UV/H2O2 treatment did not induce any noticeable reduction in DON level. Furthermore, both UV/PS and UV/H2O2 treatments reduced the dichloroacetonitrile (DCAN) formation potential (FP), leading to strong correlations with the degradation of aromatic and humic-acid-like compounds. Notably, UV/PS treatment efficiently decreased the FP of bromochloroacetonitrile (BCAN) and dramatically reduced that of dibromoacetonitrile (DBAN) after a sharp increase; however, UV/H2O2 treatment gradually increased the DBAN-FP. Bromide was activated by sulfate radicals during UV/PS treatment, negatively correlating with the BCAN-FP and DBAN-FP, indicating that the formation of reactive bromine species increased the DBAN-FP; however, excessive oxidation possibly led to the recovery of inorganic bromine for decreasing the BCAN-FP and DBAN-FP. Additionally, UV/PS treatment effectively suppressed toxicity owing to its high reduction rate for brominated HANs; in contrast, UV/H2O2 treatment resulted in less significant BCAN and DBAN reductions, leading to minimal net reduction in toxicity. Overall, UV/PS treatment was remarkably effective at diminishing the toxicity of brominated HANs, underscoring its potential to mitigate drinking-water-related health risks.

Electrospinning of poly(ethylene oxide)/glass hybrid nanofibres for anticounterfeiting encoding

The use of photochromism to increase the credibility of consumer goods has shown great promise. To provide mechanically dependable anticounterfeiting nanofibres, it has also been critical to improve the engineering processes of authentication patterns. Mechanically robust and photoluminescent electrospun poly(ethylene oxide)/glass (PGLS) nanofibres (150-350 nm) immobilized with nanoparticles of lanthanide-doped aluminate (NLA; 8-15 nm) were developed using electrospinning technology for anticounterfeiting purposes. The provided nanofibrous membranes changed colour from transparent to green when irradiated with ultraviolet light. By delivering NLA with homogeneous distribution without aggregations, we were able to keep the nanofibrous membrane transparent. When excited at 365 nm, NLA@PGLS nanofibres showed an emission intensity at 517 nm. The hydrophobicity of NLA@PGLS nanofibres improved by raising the pigment concentration as the contact angle was increased from 146.4° to 160.3°. After being triggered by ultraviolet light, NLA@PGLS showed quick and reversible photochromism without fatigue. It was shown that the suggested method can be applied to reliably produce various anticounterfeiting materials.

Improving ultraviolet protection properties of cotton textiles using Zinc oxide (ZnO) nanomaterials: an approach for controlling occupational and environmental exposures

Ultraviolet (UV) radiation exposure is one of the most important risk factor among workers. it may stimulate health outcomes such as multiple skin injuries and blinding eye diseases. So, UV protection is mainly important for people who expose to it. Modification of cotton textiles by nanomaterials is a new approach to overcome this problem. So, the aim of this study is to review studies conducted on using ZnO nanoparticles for improving ultraviolet protection of cotton textiles. The search strategy was provided by cochrane guideline. 45 studies were regarded as appropriate. The results show that UPF for textiles has improved by coated ZnO. However, UPF was depended on the physicochemical characteristics of ZnO and textiles such as yarn structure, effect of woven fabric construction, fabric porosity, and impurity of textiles and laundering conditions. Also, plasma technology has improved UPF, it is recommended that more studies be done to achieve better results.

Enhanced 2-MIB degradation by UV-LED/chlorine process: reaction kinetics, wavelength dependence, influencing factors and degradation pathways

The efficient removal of 2-Methylisoborneol (2-MIB), a typical odour component, in water treatment plants (WTPs), poses a great challenge to conventional water treatment technology due to its chemical stability. In this study, the combination of ultraviolet light-emitting diode (UV-LED) and chlorine (UV-LED/chlorine) was exploited for 2-MIB removal, and the role of ultraviolet (UV) wavelength was investigated systematically. The results showed that UV or chlorination alone did not degrade 2-MIB effectively, and the UV/chlorine process could degrade 2-MIB efficiently, following the pseudo-first-order kinetic model. The 275 nm UV exhibited higher 2-MIB degradation efficiency in this UV-LED/chlorine system than 254 nm UV, 265 nm UV and 285 nm UV due to the highest mole adsorption coefficient and quantum yield of chlorine in 275 nm UV. ·OH and ·Cl produced in the 275 nm UV/chlorine system played major roles in 2-MIB degradation. HCO3- and Natural organic matter (NOM), prevalent in water, consumed ·OH and ·Cl, thus inhibiting the 2-MIB degradation by UV-LED/chlorine. In addition, NOM and 2-MIB could form a photonic competition effect. The degradation of 2-MIB by UV-LED/chlorine was done mainly through dehydration and demethylation, and odorous intermediates, such as camphor, were produced. 2-MIB was degraded through the α bond fracture and six-membered ring opening to form saturated or unsaturated hydrocarbons and aldehydes. Four DBPs, chloroform (CF), trichloroacetaldehyde (TCE), trichloroacetone (TCP) and dichloroacetone (DCP), were mainly generated, and CF was the most significant by-product.

Comparison of ozone-based AOPs on the removal of organic matter from the secondary biochemical effluent of coking wastewater

Advanced oxidation processes (AOPs) based on ozone are gaining continuously growing popularity in wastewater treatment. This study explored the treatment of coking wastewater using a combination of ozonation (O3), ultraviolet (UV), and hydrogen peroxide (H2O2) process expressed by % chemical oxygen demand (COD) removal, % total organic carbon (TOC), % UV254, % fluorescence intensity removal and its electrical energy consumption. The obtained results demonstrated that, the combination of O3, UV, and H2O2 which is denoted by O3/UV/H2O2 in this study achieved great success in COD removal (92.08%), TOC removal (78.25%), and reduction of fluorescence intensity (99.82%). Compared with the O3 and O3/UV processes, O3/UV/H2O2 improved the COD removal by approximately 54-69% and 38-51%, respectively. In addition, the energy consumption was reduced by 53-67%. The TOC removal rate in the effluent ranged 71% and 83%, while the UV254 removal rate was up to 90%. The fluorescence spectroscopy showed that the O3/UV/H2O2 combination process reduced the fluorescence intensity by almost 97% within 10 min. Furthermore, the total polycyclic aromatic hydrocarbons (PAHs) concentration in the effluent was less than 10μg/L (removal efficiency > 80%) and the most toxic benzo(a)pyrene (BaP) was less than 0.03 μg/L (0.018μg/L). In addition, the energy consumption of the O3/UV/H2O2 process was 53-67% lower than those of O3 and O3/UV processes. Furthermore, the energy consumption was 80.26 kWh m-3 after 60 min of reaction time when the COD (69.3 mg/L) met the standard discharge. Finally, the O3/UV/H2O2 process could be an effective method for improving the mineralisation of refractory organic matter.