UVA Irradiation Research Articles

H16 Arsenic to biologics: psoriasis treatment through the ages

Abstract In the 19th century when arsenic was the recommended treatment for psoriasis, little consideration was given to the toxic side-effects of the potent carcinogen. Thomas Girdlestone, an English physician, is said to have been the first to advocate for the use of arsenic to treat psoriasis. Girdlestone prescribed Fowler’s solution, a solution of potassium arsenite 1%. In 1876, Alexander John Balmanno Squire inadvertently discovered dithranol, a known treatment for ringworm, to be efficacious in treating psoriasis. However, it was Eugen Galewsky, in 1916, who then went on to synthesize anthralin, a synthetic form of dithranol, to target psoriasis. A key historical figure was William H. Geockerman, an American dermatologist, who developed Goekerman therapy—a regimen that combined the use of coal tar and ultraviolet (UV) light to treat moderate-to-severe plaque psoriasis. In 1953, John Ingram, an English dermatologist, discovered that the beneficial effects of dithranol paste could be enhanced by adding it to coal tar and UV light—later coined the ‘Ingram regimen’. Philip Showalter Hench, Edward Calvin Kendall and Tadeus Reichstein received the Nobel Prize in Medicine and Physiology for the development of cortisone; it proved to be useful in topically treating many skin diseases, but it had a limited effect on psoriasis. The production of synthetic corticosteroids soon followed, which, conversely, proved to be successful in treating psoriasis. However, the daunting side-effects of corticosteroids limited their long-term use. In 1951, a patient with rheumatoid arthritis showed dramatic improvement in their psoriasis when treated with aminopterin, as recorded by Richard Gubner, a New York cardiologist. PUVA was developed in the 1970s—a photochemotherapy for psoriasis that combined psoralen with UVA radiation to clear skin lesions. Interestingly, in 1500 Bc, the ancient Egyptians were known to use a combination of psoralen and sunlight to treat vitiligo. Furthermore, in the 1980s, researchers noted complete clearance of psoriasis in a patient with osteoporosis who was prescribed an oral form of vitamin D. This chance observation then led to the development of topical vitamin D analogues for the treatment of psoriasis that work by encouraging normal skin growth and slowing down overproduction of skin cells. Finally, in 2003, the first biologic treatments were approved for psoriasis by the US Food and Drug Administration—a significantly safer and more efficacious alternative to the controversial arsenic treatments that were used over 200 years ago.

Biocomposites based on poly(lactic acid)/Aloe Vera/Priplast. Effects of UVA radiation on the crystallization

AbstractBiocomposites based on poly(lactic acid) (PLA), Aloe Vera (AV), and Priplast (Pr), were produced with AV and Pr levels of 5% and 10%, and submitted to UVA radiation for a time interval up to 28 days. Chemical changes were investigated using Fourier transform infrared spectroscopy (FTIR) and the thermal behavior was elucidated using differential scanning calorimetry (DSC); the non‐isothermal crystallization kinetics was modeled using the Pseudo‐Avrami model. FTIR spectra evidenced the formation of chromophore groups resulting from the photodegradation, which it was less intense in biocomposites with 10% Pr. AV addition promoted the cold crystallization, whereas the crystallization rate () displayed higher values for PLA/10%AV, with slight increases in the degree of crystallinity (Xc); while Pr addition decreased the Xc and of PLA, and protected it more intensely against the photodegradation effects. Pseudo‐Avrami model presented R2 ≥ 0.9909 and a low discrepancy between experimental and theoretical data, being adequate to describe the cold crystallization of PLA biocomposites. Summing up, AV and Pr addition protect PLA against the harmful effects of photodegradation, with AV subtly interfering in the crystalline parameters while Pr provides greater amorphicity to PLA biocomposites.

Propolis as a Cariostatic Agent in Lozenges and Impact of Storage Conditions on the Stability of Propolis.

Propolis is known as a source of compounds with strong antibacterial activity. Due to the antibacterial effect against streptococci of the oral cavity, it seems to be a useful agent in decreasing the accumulation of dental plaque. It is rich in polyphenols which are responsible for a beneficial impact on the oral microbiota and antibacterial effect. The aim of the study was to evaluate the antibacterial effect of Polish propolis against cariogenic bacteria. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined on cariogenic streptococci related to the occurrence of dental caries. Lozenges based on xylitol, glycerin, gelatin, water, and ethanol extract of propolis (EEP) were prepared. The effect of prepared lozenges on cariogenic bacteria was assessed. Propolis was compared to chlorhexidine which is used in dentistry as the gold standard. In addition, the prepared propolis formulation was stored under stress conditions to assess the influence of physical conditions (i.e., temperature, relative humidity, and UV radiation). In the experiment, thermal analyses were also performed to evaluate the compatibility of propolis with the substrate used to create the base of lozenges. The observed antibacterial effect of propolis and prepared lozenges with EEP may suggest directing subsequent research on prophylactic and therapeutic properties decreasing the accumulation of dental plaque. Therefore, it is worth highlighting that propolis may play an important role in the management of dental health and bring advantages in preventing periodontal diseases and caries as well as dental plaque. The colorimetric analyses carried out in the CIE L*a*b* system, microscopic examinations, and TGA/DTG/c-DTA measurements indicate the unfavorable effect of the tested storage conditions on the lozenges with propolis. This fact is particularly evident for lozenges stored under stress conditions, i.e., 40 °C/75% RH/14 days, and lozenges exposed to UVA radiation for 60 min. In addition, the obtained thermograms of the tested samples indicate the thermal compatibility of the ingredients used to create the formulation of lozenges.

Lanthanum hydroxychloride/anatase composite and its application for effective UV-light driven oxidation of the emergent water contaminant cetirizine

This work reports on the successful synthesis of a new composite named TiO2@La(OH)2Cl using a sol-gel and hydrothermal route. This method is considered an inexpensive and environmentally friendly synthetic method to produce materials with controllable size and morphology. A combination of X-Ray powder diffraction, X-Ray photoelectron spectrometry and Scanning Electron Microscopy revealed that the composite is made of micrometric platelets of La(OH)2Cl covered by c.a. 10 nm TiO2 anatase nanoparticles. The activity in photocatalytic reactions was examined through cetirizine degradation under UV-A irradiation. Results of the screening studies confirmed the excellent photocatalytic activity of the as-synthesized composite compared to pure anatase and pure La(OH)2Cl, highlighting the positive role of the synergy between the two solids. The composite was further explored in detail in terms of catalyst load, pollutant concentration, water matrix and mechanism of the reaction. The target molecule was completely removed from the aqueous suspension at 2.5 mg/L of pollutant and 0.2 g/L of catalyst load. Also, reaction mechanism evaluation showed the active role of hydroxyl radicals in the degradation of cetirizine by the TiO2@La(OH)2Cl composite. Additionally, phytotoxicity investigations were performed to study the germination of cress seeds for treated and raw solutions. Data revealed that the degradation reaction products for cetirizine were scarcely toxic compared to the untreated sample confirming the usefulness of the photocatalytic treatment with the TiO2@La(OH)2Cl composite. Lastly, all these data demonstrate the excellent catalytic efficiency of the new synthesized material, opening new ways for its use for future applications for water purification.

Accelerated aging of polymer composite from Pennisetum purpureum fibers with recycled low-density polyethylene

The use of natural fibers (NF) as reinforcement in polymer composites have been an interesting option to improve their mechanical properties and to decrease production costs since several crops can produce large amounts of NF with low cost. This is particularly attractive for polymer waste recycling that depends of the production of cheap materials to be economically viable. Elephant grass ( Pennisetum purpureum schum) is a tropical climate plant of fast growth with high potential for production of NF. However, studies on the use of P. purpureum fibers as reinforcement in polymers, mainly for recycled polymers, have been restricted. The aims of this study was to evaluate the action of the P. purpureum fibers on the properties of composites using matrix of low-density polyethylene waste (LDPE-w) as well as to verify the behavior of recycled polymer when submitted to the accelerated photochemical aging using UVA radiation. LDPE-w and LDPE-w composite with P. purpureum fibers (LDPE-composite) were analyzed at different aging times by tensile and impact tests, melt flow rate, scanning electron microscopy and Fourier transform infrared. It was verified that P. purpureum fibers induce defects in matrix of LDPE-w, decreasing the performance of mechanical properties. Similar effect also occurs when LDPE-w is submitted to the first hours of accelerated aging. On the other hand, effects of stabilization of the degradation on the polymer matrix can be attributed to the P. purpureum fibers at high aging times. Thus, P. purpureum presents high potential for use as reinforcement in recycled thermoplastic waste.

Improving indoor air quality by using photocatalytic paints. Real scale study at the Technical University of Madrid

People spend more than 90% of their time in indoor spaces, and, therefore, exposure to pollutants is high when inhabiting infrastructures with poor air quality. The pollutants present inside a building come either from inside the building itself (inhabitants, activity developed, etc), or from the outside (traffic, nearby industrial activity, etc). Among air cleaning techniques, building materials that incorporate a photocatalyst are considered to be a promising alternative. Photocatalysis is an Advanced Oxidation Process consisting of the oxidation/mineralization of pollutants in contact with a photocatalytic surface and the presence of UVA and sunlight irradiation. In this work, a photocatalytic paint based on TiO2 and active under indoor illumination conditions (ProCleanAir®, by PROQUICESA S.L.) was tested in a lecture room, evaluating the concentration of NO2 monitored by Palmes passive samplers. There was a decrease in the concentration of pollution after the application of the paint, with the depolluting effect remaining for one year, but also being dependent on atmospheric conditions. The statistical significance of the results was confirmed by t-student analyses.

Supplementary UV-A and UV-B radiation differentially regulate morphology in Ocimum basilicum.

UV-A- or UV-B-enriched growth light was given to basil plants at non-stress-inducing intensities. UV-A-enriched growth light gave rise to a sharp rise in the expression of PAL and CHS genes in leaves, an effect that rapidly declined after 1-2days of exposure. On the other hand, leaves of plants grown in UV-B-enriched light had a more stable and long-lasting increase in the expression of these genes and also showed a stronger increase in leaf epidermal flavonol content. UV supplementation of growth light also led to shorter more compact plants with a stronger UV effect the younger the tissue. The effect was more prominent in plants grown under UV-B-enriched light than in those grown under UV-A. Parameters particularly affected were internode lengths, petiole lengths and stem stiffness. In fact, the bending angle of the 2nd internode was found to increase as much as 67% and 162% for plants grown in the UV-A- and UV-B-enriched treatments, respectively. The decreased stem stiffness was probably caused by both an observed smaller internode diameter and a lower specific stem weight, as well as a possible decline in lignin biosynthesis due to competition for precursors by the increased flavonoid biosynthesis. Overall, at the intensities used, UV-B wavelengths are stronger regulators of morphology, gene expression and flavonoid biosynthesis than UV-A wavelengths.

Lipidome Investigation of Carnosine Effect on Nude Mice Skin to Prevent UV-A Damage.

The lipid profile of skin is fundamental in the maintenance of the protective barrier against the external environment. Signaling and constitutive lipids of this large organ are involved in inflammation, metabolism, aging, and wound healing, such as phospholipids, triglycerides, FFA, and sphingomyelin. Skin exposure to ultraviolet (UV) radiation results in a photoaging process that is an accelerated form of aging. UV-A radiation deeply penetrates the dermis and promotes damage to DNA, lipids, and proteins by increasing the generation of reactive oxygen species (ROS). Carnosine, an endogenous β-alanyl-L-histidine dipeptide, demonstrated antioxidant properties that prevent photoaging and modification of skin protein profiling, making carnosine a compelling ingredient to consider for use in dermatology. The aim of this research was to investigate the modification of skin lipidome after UV-A treatment in presence or not of topic administration of carnosine. Quantitative analyses based on high-resolution mass spectrometry of nude mice skin-extracted lipids resulted in several modifications of barrier composition after UV-A radiation, with or without carnosine treatment. In total, 328 out of 683 molecules showed significant alteration-262 after UV-A radiation and 126 after UV-A and carnosine treatment versus controls. Importantly, the increased oxidized TGs after UV-A radiation, responsible of dermis photoaging, were completely reverted by carnosine application to prevent the UV-A damage. Network analyses also showed that the production of ROS and the calcium and TNF signaling were modulated by UV-A and carnosine. In conclusion, lipidome analyses attested the carnosine activity to prevent the UV-A damage, reducing the lipid oxidation, the inflammation, and the dysregulation of lipid skin barrier.

Hyperoside as a UV Photoprotective or Photostimulating Compound-Evaluation of the Effect of UV Radiation with Selected UV-Absorbing Organic Compounds on Skin Cells.

Ultraviolet (UV) radiation is a non-ionizing radiation, which has a cytotoxic potential, and it is therefore necessary to protect against it. Human skin is exposed to the longer-wavelength components of UV radiation (UVA and UVB) from the sun. In the present paper, we focused on the study of eight organic UV-absorbing compounds: astragalin, beta-carotene, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, hyperoside, 3-(4-methylbenzylidene)camphor, pachypodol, and trans-urocanic acid, as possible protectives of skin cells against UVA and UVB radiation. Their protective effects on skin cell viability, ROS production, mitochondrial membrane potential, liposomal permeability, and DNA integrity were investigated. Only some of the compounds studied, such as trans-urocanic acid and hyperoside, had a significant effect on the examined hallmarks of UV-induced cell damage. This was also confirmed by an atomic force microscopy study of morphological changes in HaCaT cells or a study conducted on a 3D skin model. In conclusion, hyperoside was found to be a very effective UV-protective compound, especially against UVA radiation. Commonly used sunscreen compounds such as 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, and 3-(4-methylbenzylidene)camphor turned out to be only physical UV filters, and pachypodol with a relatively high absorption in the UVA region was shown to be more phototoxic than photoprotective.

A comparison of endosulfan removal by photocatalysis process under UV-A and visible light irradiation: optimization, degradation byproducts and reuse.

The online version contains supplementary material available at 10.1007/s40201-023-00864-z.

Impact of ultraviolet radiation on the skin and the role of photoprotection – the review of the literature

Introduction and objective: 
 The sun emits ultraviolet radiation in the UV-A, UV-B and UV-C ranges. Photoprotection is used to prevent the impact of this radiation on the skin. It effectively counteracts photoaging, photodermatoses and photocarcinogenesis.
 The aim of the study is to discuss the impact of UV radiation on the skin and the role of sun protection, also in special groups of patients - children and non-immunocompetent people. The article also presents a summary of data on the effect of sunscreens on vitamin D synthesis.
 Materials and methods: 
 The literature was reviewed in the Pubmed, Google Scholar database and in the recommendations of the Polish Dermatological Society with the use of keywords.
 State of knowledge: 
 Erythema is the most visible effect of sunburn, but exposure to UV radiation is primarily photocarcinogenesis or photoimmunosuppression. The SPF factor is the main determinant of the effectiveness of sunscreens, but effective protection against both UVB and UVA radiation is essential. Daily use of sunscreen reduces skin damage associated with exposure to light and does not negatively affect vitamin D synthesis.
 Conclusions:
 The basis of skin protection is using sunscreens, avoiding excessive exposure to solar radiation and using protective clothing, hats and sunglasses. Thanks to these activities, we can significantly reduce the number of cases of certain skin cancers. It is also important to remember that sun protection applies to everyone, especially children and non-immunocompetent people.

Physiological and molecular effects of TiO2 nanoparticle application on UV-A radiation stress responses in Solanum lycopersicum L.

Nanoparticles (NPs) of titanium dioxide (TiO2) alter photosynthetic and biochemical parameters in Solanum lycopersicum L., possibly due to their photocatalytic properties given by energy absorption in the UV-A range; however, the joint effects TiO2 NPs and UV-A radiation are not well understood. This work evaluates the combined responses of TiO2 NPs and UV-A radiation at the physiological and molecular levels in S. lycopersicum. In a split growth chamber, the presence (UV-A +) and absence (UV-A -) of UV-A were combined with 0 (water as a control), and 1000 and 2000mg L-1 of TiO2 NPs applied at sowing. At the end of exposure (day 30 after sowing), the photosynthetic performance was determined, and biochemical and molecular parameters were evaluated in leaf tissues. Better photochemical performance in UV-A + than UV-A - in control plants was observed, but these effects decreased in 1000 and 2000mg TiO2 L-1, similar to net CO2 assimilation. A clear increase in photosynthetic pigment levels was recorded under UV-A + compared to UV-A - that was positively correlated with photosynthetic parameters. A concomitant increase in total phenols was observed on adding TiO2 in UV-A - conditions, while a decreasing trend in lipid peroxidation was observed for the same treatments. There was an increase in psbB gene expression under TiO2/UV-A + treatments, and a reduced expression of rbcS and rbcL under UV-A - . These results suggest that the reduction in photosynthetic performance on applying high doses of TiO2 NPs is probably due to biochemical limitation, while UV-A achieves the same result via the photochemical component.

Toward a better understanding of peroxymonosulfate and peroxydisulfate activation using a nano zero-valent iron catalyst supported on graphitized carbon: Mechanisms and application to the degradation of estrogenic compounds in different water matrix

In this study, we employed nano zero-valent iron catalysts supported on graphitized carbon (GC-nZVI) catalyst to efficiently degrade BPA under circumneutral pH conditions in both dark and UVA radiation. The GC-nZVI catalyst was characterized using specific techniques (XPS, FTIR, BET, etc.), and was used to activate both PS and PMS in solution. Although no significant BPA degradation constant (kBPA) was determined using PS/PMS or GC-nZVI alone, a significant synergistic effect was observed in the system. Under dark conditions, kBPA increased from 0.01 min−1 to 0.17 when PS was used, both in the dark and under UVA. Notably, when PMS was present in the system, the improvement was even higher with kBPA reaching 0.18 and 0.26 min−1 under dark and UVA conditions, respectively. To further support the synergistic effect, it was found that 80% of mineralization was achieved within 2 h of UVA exposure.Chemical quenching experiments were conducted using selective probes and kinetic modelling showed that the activation of PS/PMS produced sulfate radicals (SO4•−), hydroxyl radicals (•OH) and ferryl ions (FeIVO2+) in both systems. Additionally, GC-nZVI/PMS system demonstrated good stability in recycling experiments, with up to 70% of BPA still being degraded after 3 cycled in 1 h under UVA.In conclusion, the degradation efficiencies of GC-nZVI/PMS and GC-nZVI/PS systems under dark and UVA radiation were assessed for three different EDCs (BPA, E2, and EE2) in both tap and sewage treatment plant waters.This study has demonstrated that the highly efficient GC-nZVI/PS/UVA or GC-nZVI/PMS/UVA system has significant potential for application in different water matrix, and our findings provide insights into the design of heterogeneous Fenton-like and photo-Fenton-like catalysts.

Stone Endurance: A Comparative Analysis of Natural and Artificial Weathering on Stone Longevity

The long-term endurance of building stones must be assured since their longevity has repercussions for their economic and social value. Frequently, slabs for flooring and cladding are installed with polished finishing in outdoor environments for technical and ornamental purposes in cultural heritage sites and modern civil architecture. Compared to any other finishing, glossy surfaces are rather vulnerable to wear, particularly when they interact with slightly acidic rainwater. Several hydrophobic treatments are applied to prevent this damage by preventing contact between rain and stone; such treatments are efficient but sometimes non-durable. Stakeholders and conservation scientists need better methods to anticipate the future behaviour of this building material and hydrophobic solutions. Complying with this demand, a comparison is made between outdoor natural ageing and artificial weathering, reproduced by UVA radiation, moisture and spray accelerated weathering. Artificial weathering is applied to predict the behaviour of stones over time in the real environment. Data obtained through the measurement of gloss and colour parameters, the detection of micro-textures through SEM, and the calculation of micro-roughness using a digital rugosimeter demonstrate that weakly acidic rainwater is the main cause of superficial decay of stone finishing over just six months of outdoor exposure. This period corresponds to 7–14 days of artificial weathering. Furthermore, the loss of efficiency and durability of the hydrophobic coatings is detected by measuring the static contact angle. This highlights that even if a protective treatment was proficient, it could easily deteriorate in normal weathering conditions if applied on polished, low-porosity stone. Additionally, water vapour permeability indicates variations of regular vapour transmission through the stones due to ageing. The first solution to threats is the prevention of pathologies, including aesthetic ones. A careful choice of the most suitable lithotype finish and an environmental study represent an existing solution to the problem. It must be highlighted that aesthetic requirements should not be prioritised to detriment of the technical requirements of architectural quality, performance, durability, and safety.

Pilot-scale regeneration of wastewater through intensified sulfate radical-based advanced oxidation processes (PMS/UV-A, PMS/H2O2/UV-A, and PMS/O3): Inactivation of bacteria and mechanistic considerations

This research addresses the application of advanced oxidation processes (AOPs) for wastewater reclamation at pilot scale, one of the main limitations usually observed in this type of technology. Although interest in sulfate radical-based AOPs (SR-AOPs) has increased considerably in recent years, pilot-scale application studies are very scarce. The generation of free radicals by activation of peroxymonosulfate (PMS) can be enhanced by the introduction of UV-A radiation, or other oxidants such as hydrogen peroxide (H2O2) or ozone (O3), increasing the efficiency of the processes with lower reagent consumption.The combination of 0.5 mM PMS and 0.25 g·h−1 O3 was the fastest process in inactivation of Enterococcus faecalis, achieving inactivation in less than 45 min. Significant synergies were also observed for the combination of PMS, H2O2 and UV-A radiation, achieving total inactivation in less than 120 min, a performance significantly lower than that of the PMS/O3 system. Mechanistic studies showed that the sulfate radical (SO4•-) was responsible for bacterial inactivation in the PMS/O3 system, while in the PMS/H2O2/UV-A system the predominant species varies according to the molar ratio of the oxidants. Thus, the hydroxyl radical (•OH) is predominant in a 1:1 ratio, and SO4•- is predominant in a 1:3 ratio. This phenomenon occurs because an excess of PMS acts as a sink for radicals, preventing their interaction with bacteria.The treatments studied have been shown to be effective in the simultaneous elimination of several pathogenic microorganisms such as Enterococcus faecalis, Escherichia coli, and Staphylococcus aureus, making this technology an alternative to conventional disinfection treatments.

Photochemoprevention of topical formulation containing purified fraction of Inga edulis leaves extract.

Natural antioxidants have attracted attention for their therapeutic use as photochemopreventive agents. Inga edulis leaves extract and its purified fraction have high polyphenolic content and high antioxidant capacity. In addition, they presented UV photostability and low citotoxicity in fibroblast cells. In this context, this study first aimed at development of topical formulation containing purified fraction of I. edulis extract and the evaluation of skin penetration of the compounds. Moreover, the photoprotective/photochemopreventive potential of the formulation containing I. edulis purified fraction were investigated in vitro and in vivo. The topical formulation containing 1% of the purified fraction of I. edulis increased the endogenous antioxidant potential of the skin, and vicenin-2 and myricetin compounds were able to penetrate the epidermis and dermis. Additionally, the purified fraction (25 and 50 mg/mL) showed a photoprotective effect against UVA and UVB radiation in L929 fibroblast cells. In vivo studies have shown that the formulation added with purified fraction provided an anti-inflammatory effect on the skin of animals after UVB exposure, since it was observed a reduction in MPO activity, IL-1β and TNF-α cytokines, and CXCL1/KC chemokine concentrations. In conclusion, the purified fraction of I. edulis, rich in phenolic compounds, when incorporated in topical formulation, appears as an alternative to prevent skin damages induced by UV radiation, due to its antioxidant and anti-inflammatory properties.

Predicting corneal cross-linking treatment efficacy with real-time assessment of corneal riboflavin concentration.

To assess predictability of tissue biomechanical stiffening induced by UV-A light-mediated real-time assessment of riboflavin concentration during corneal crosslinking (CXL) of human donor tissues. Studio Italiano di Oftalmologia, Rome, Italy. Laboratory study. 20 sclerocorneal tissues were randomly stratified to undergo CXL with either the epithelium intact (n = 12) or removed (n = 8). Samples underwent corneal soaking with 0.22% riboflavin formulation (RitSight) with dosing time of t = 10 minutes and t = 20 minutes in epithelium-off and epithelium-on protocols, respectively. All tissues underwent 9-minute UV-A irradiance at 10 mW/cm 2 using theranostic device (C4V CHROMO4VIS). The device used controlled UV-A light irradiation to induce both imaging and treatment of the cornea, providing a real-time measure of corneal riboflavin concentration and treatment efficacy (ie, theranostic score) during surgery. Tissue biomechanics were assessed with an air-puff device (Corvis), which was performed before and after treatment. A 3-element viscoelastic model was developed to fit the corneal deformation response to air-puff excitation and to calculate the mean corneal stiffness parameter (k c ). Significant corneal tissue stiffening ( P < .05) was induced by the theranostic UV-A device in either CXL treatment protocol. Significant correlation was found between the theranostic score and the increase in k c ( R = 0.75; P = .003). The score showed high accuracy (94%) and precision (94%) to predict correctly samples that had improved tissue biomechanical strengthening. Real-time assessment of corneal riboflavin concentration provided a predictive and precise approach for significant improvement of tissue strength on individual corneas, regardless of CXL treatment protocol.

FentonSims®: A novel interactive simulation tool for computational kinetics of microcontaminant removal by the solar photo-Fenton process

This work presents, for the first time, a simulation app for the mechanistic understanding of the solar photo-Fenton process applied to the removal of microcontaminants contained in wastewater treatment plant secondary effluents. FentonSims® incorporates three mechanistic kinetic models previously developed for the process at acidic and neutral pH with different iron chelators (nitrilotriacetic acid and ethylenediamine-N,N’-disuccinic acid). The end-user can simulate the operation of perfect mixing raceway pond reactors in batch and continuous mode as a function of environmental (UVA radiation and water liquid temperature) and operating conditions (hydraulic residence time, liquid depth and reagent concentrations). Furthermore, this tool allows the assessment of different levels of water contamination, and estimations for reagent conversion, microcontaminant removal yield and water treatment capacity are shown in the graphical user interface. Simulations are conducted in an intuitive and easy-to-use app, so no programming skills are required, and all data are saved, allowing the user to analyse a wide range of operating scenarios. Therefore, FentonSims® is a valuable didactic tool for graduate students and water treatment professionals interested in the applicability of the solar photo-Fenton process and its phenomenological understanding.

Fabrication of eco-friendly transparent wood for UV-shielding functionality

Recently, transparent wood (TW) has been considered for many applications, such as windows, energy storage, and electronic devices. This study presents the fabrication of eco-friendly TW using waste lignin as a resource to enhance the TW’s performance by providing UV-shielding functionality. Three different pretreatment methods were explored for TW fabrication, including solar-assisted bleaching, steam bleaching, and NaOH delignification. The average size of the lignin nanoparticles (LNs) characterized using a scanning electron microscope and nanoparticle analyzer and was found to be around 100 nm. The LNs had zeta potentials of − 44.2 mV to − 34.9 mV for the first and sixth months, respectively. The transmittance of TW ranged from 20% to 80%, depending on the pretreatment and additional LNs content. By incorporating just 1% of LN, the TW composites were found to effectively block all UV-C, UV-B, and UV-A radiation while maintaining adequate visible light transmittance. The thermal stability, crystallinity index, and mechanical properties of wood and TW were investigated and compared. The NaOH delignification TW (Na-TW) has shown the highest transmittance, tensile strength, UV-shielding functionality, and comparable thermal stability with solar transparent wood (SL-TW) and steam transparent wood (ST-TW) methods. These findings indicate that TW LNs nanocomposite is a promising candidate for UV-shielding window applications.

Photocatalytic degradation of organic micropollutants under UV-A and visible light irradiation by exfoliated g-C3N4 catalysts

In the present study, the photocatalytic performance of exfoliated graphitic carbon nitride (g-C3N4) catalysts, with enhanced properties and response in UV and visible light irradiation, was evaluated for the removal of selected contaminants i.e., diuron, bisphenol A and ethyl paraben. Commercial TiO2 Degussa P25 was also used as a reference photocatalyst. The g-C3N4 catalysts demonstrated good photocatalytic activity which in some cases is comparable to TiO2 Degussa P25 leading to high removal percentages of the studied micropollutants under UV-A light irradiation. In contrast to TiO2 Degussa P25, g-C3N4 catalysts were also able to degrade the studied micropollutants under visible light irradiation. For all the studied g-C3N4 catalysts under both UV-A and visible light irradiation, the overall degradation rate decreases in the order of bisphenol A > diuron > ethyl paraben. Among the studied g-C3N4, the chemically exfoliated catalyst (g-C3N4-CHEM) showed superior photocatalytic activity under UV-A light irradiation due to its enhanced characteristics, such as pore volume and specific surface area and ~ 82.0 % in 6 min, ~75.7 % in 15 min and ~ 96.3 % in 40 min removals were achieved for BPA, DIU and EP, respectively. Under visible light irradiation, the thermally exfoliated catalyst (g-C3N4-THERM) demonstrated the best photocatalytic performance and the degradation ranged from ~29.5 to 59.4 % after 120 min. EPR data revealed that the three g-C3N4 semiconductors generate mainly O2•−, whereas TiO2 Degussa P25 generates both HO• and O2•−, the latter only under UV-A light irradiation. Nevertheless, the indirect formation of HO• in the case of g-C3N4 should also be considered. Hydroxylation, oxidation, dealkylation, dechlorination and ring opening were the main degradation pathways. The process proceeded without significant alterations in toxicity levels. Based on the results, heterogeneous photocatalysis using g-C3N4 catalysts is a promising method for the removal of organic micropollutants without the formation of harmful transformation products.