Comparison of UVA vs UVB Photoaging Rat Models in Short-term Exposure.

Background: Prolonged exposure to sunlight is known to induce photoaging of the skin, leading to various skin changes and disorders, such as dryness, wrinkles, irregular pigmentation, and even cancer. Ultraviolet A (UVA) and ultraviolet B (UVB) radiation are particularly responsible for causing photoaging. Objective: This study aims to identify and compare photoaging rat models exposed to UVA and UVB. Methods: This research method compared macroscopic (scoring degree of wrinkling) and microscopic (histology) signs and symptoms on skin samples of rat exposed to UVA and UVB for 4 weeks at a radiation dose of 840mJ/cm2. Results: The results of this study indicated that the degree of wrinkling was highest in rat skin exposed to UVB rays by 51% (p<0.05). UVB histological results showed that the epidermis layer (40 µm, p<0.05) was thickened and the dermis layer (283 µm, p<0.05) was thinned in the skin of mice exposed to UVB light. The UVB group, showed the density of collagen in the dermis with a mean value of 55% (p<0.05). Conclusion: Our results suggest that short-term exposure to UVB radiation (in the acute, subacute or subchronic phase) induces more rapid and pronounced damage to rat skin when compared to UVA radiation exposure.

Innovative approaches to neonatal jaundice diagnosis and management in low-resourced settings.

Persistent challenges in addressing severe neonatal hyperbilirubinaemia in resource-constrained settings have led to ongoing and often unacceptable rates of morbidity, disability and mortality. These challenges stem from limitations such as inadequate, inefficient or financially inaccessible diagnostic and therapeutic options. However, over the past decade, noteworthy innovations have emerged to address some of these hurdles, and these innovations are increasingly poised for broader implementation. This review provides a concise summary of these novel, economically viable diagnostic solutions, encompassing point-of-care assays and smartphone applications, as well as treatment modalities, notably more effective phototherapy and filtered sunlight. These advancements hold promise and have the potential to meaningfully reduce the burden of neonatal hyperbilirubinaemia, signifying a promising shift in the landscape of neonatal healthcare.

Sunlight-triggered prebiotic nanomotors for inhibition and elimination of pathogen and biofilm in aquatic environment.

Pathogen contamination in drinking water sources causes waterborne infectious diseases, seriously threatening human health. Nowadays, stimuli-responsive self-propelled nanomotors are appealing therapeutic agents for antibacterial therapy in vivo. However, achieving water disinfection using these nanobots is still a great challenge. Herein, we report on prebiotic galactooligosaccharide-based nanomotors for sunlight-regulated water disinfection. The nanomotors can utilize galactooligosaccharide-based N-nitrosamines as sunlight-responsive fuels for the spontaneous production of antibacterial nitric oxide. Such a solar-to-chemical energy conversion would power the nanomotors for self-diffusiophoresis, which could promote the diffusion of the nanomotors in water and their penetration in the biofilm, significantly enhancing the inhibition and elimination of the pathogens and their biofilms in aquatic environments. After water treatments, the prebiotic-based residual disinfectants can be selectively utilized by beneficial bacteria to effectively relieve safety risks to the environment and human health. The low-energy-cost, green and potent antibacterial nanobots show promising potential in water disinfection.

Safe Viewing of Solar Eclipses.

This JAMA Patient Page describes solar eclipses and how to view them safely.

Enhanced photocatalytic ammonia oxidation over WO3@TiO2 heterostructures by constructing an interfacial electric field.

WO3 nanorods and xWO3@TiO2 (WO3/TiO2 mass ratio (x) = 1-5) photocatalysts were synthesized using the hydrothermal and sol-gel methods, respectively. The photocatalytic activities of xWO3@TiO2 for NH3 oxidation first increased and then decreased with a rise in TiO2 content. Among them, the heterostructured 3WO3@TiO2 photocatalyst showed the highest NH3 conversion (58 %) under the simulated sunlight irradiation, which was about two times higher than those of WO3 and TiO2. Furthermore, the smallest amounts of by-products (i.e., NO and NO2) were produced over 3WO3@TiO2. The enhancement in photocatalytic performance (i.e., NH3 conversion and N2 selectivity) of 3WO3@TiO2 was mainly attributed to the formed interfacial electric field between WO3 and TiO2, which promoted efficient separation and transfer of photogenerated charge carriers. Based on the results of reactive species trapping and active radical detection, photocatalytic oxidation of NH3 over 3WO3@TiO2 was governed by the photogenerated holes and superoxide radicals. This work combines two strategies of morphological regulation and interfacial electric field construction to simultaneously improve light utilization and photogenerated charge separation efficiency, which promotes the development of full-spectrum photocatalysts for the removal of ammonia.

Sunlight-Driven Photochemical Removal of Polypropylene Microplastics from Surface Waters Follows Linear Kinetics and Does Not Result in Fragmentation.

Floating microplastics are susceptible to sunlight-driven photodegradation, which can convert plastic carbon to dissolved organic carbon (DOC) and can facilitate microplastic fragmentation by mechanical forces. To understand the photochemical fate of sub-millimeter buoyant plastics, ∼0.6 mm polypropylene microplastics were photodegraded while tracking plastic mass, carbon, and particle size distributions. Plastic mass loss and carbon loss followed linear kinetics. At most time points DOC accumulation accounted for under 50% of the total plastic carbon lost. DOC accumulation followed sigmoidal kinetics, not the exponential kinetics previously reported for shorter irradiations. Thus, we suggest that estimates of plastic lifespan based on exponential DOC accumulation are inaccurate. Instead, linear plastic-C mass and plastic mass loss kinetics should be used, and these methods result in longer estimates of photochemical lifetimes for plastics in surface waters. Scanning electron microscopy revealed that photoirradiation produced two distinct patterns of cracking on the particles. However, size distribution analyses indicated that fragmentation was minimal. Instead, the initial population of microplastics shrank in size during irradiations, indicating photoirradiation in tranquil waters (i.e., without mechanical forcing) dissolved sub-millimeter plastics without fragmentation.

Reliability and validity of the Chinese version of the sunlight exposure questionnaire.

Objective: This study aimed to translate and validate the reliability and validity of the Chinese version of the Philippines Sunlight Exposure Questionnaire. Methods: A total of 392 Chinese individuals aged at least 18 years, residing in various cities in Sichuan province for at least 1 year, were recruited. The reliability of the Chinese version of the questionnaire was measured through internal consistency, split-half reliability, and retest reliability, while validity was determined using the content validity index and the structure validity index. Results: The Chinese version of the Sunlight Exposure Questionnaire, which includes 19 items covering 5 factors, demonstrated McDonald's omega coefficient of 0.788. The split-half reliability of the questionnaire was 0.823, and the retest reliability was 0.940. The content validity index (S-CVI) was 0.952. The five-factor structure, supported by eigenvalues, explained 66.2% of the total variance. Confirmatory factor analysis indicated favorable model fit. Results: The chi-square value degrees of freedom ratio (χ2/df) = 1.852, the goodness-of-fit index (GFI) = 0.938, the normed fit index (NFI) = 0.922, the incremental fit index (IFI) = 0.962, the comparative fit index (CFI) = 0.962, the Tucker-Lewis index (TLI) = 0.952, and root mean square error of approximation (RMSEA) = 0.047. The indicators of the fit of the model were within reasonable bounds. Conclusion: The Chinese version of the Sunlight Exposure Questionnaire shows validity and good reliability for assessing sun exposure among adults in a Chinese cultural context.

Green Synthesis of Uncoated and Olive Leaf Extract-Coated Silver Nanoparticles: Sunlight Photocatalytic, Antiparasitic, and Antifungal Activities.

The circular economy, which attempts to decrease agricultural waste while also improving sustainable development through the production of sustainable products from waste and by-products, is currently one of the main objectives of environmental research. Taking this view, this study used a green approach to synthesize two forms of silver nanoparticles: coated silver nanoparticles with olive leaf extract (Ag-olive) and uncoated pure silver nanoparticles (Ag-pure), which were produced by the calcination of Ag-olive at 550 °C. The extract and the fabricated nanoparticles were characterized by a variety of physicochemical techniques, including high-performance liquid chromatography (HPLC), thermal gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Adult ticks (Hyalomma dromedarii) (Acari: Ixodidae) were used in this study to evaluate the antiparasitic activity of synthesized nanoparticles and extract. Furthermore, the antifungal activity was evaluated against Aspergillus aculeatus strain N (MW958085), Fuserium oxysporum (MT550034), and Alternaria tenuissiuma (MT550036). In both antiparasitic and antifungal tests, the as-synthesized Ag-olive showed higher inhibition activity than Ag-pure and olive leaf extract. The findings of this research suggest that Ag-olive may be a powerful and eco-friendly antiparasitic and antifungal agent. Ag-pure was also evaluated as a photocatalyst under sunlight for the detoxification of Eri-chrome-black T (EBT), methylene blue (MB), methyl orange (MO), and rhodamine B (RhB).

A modified particle swarm optimization rat search algorithm and its engineering application.

Solar energy generation requires photovoltaic (PV) systems to be optimised, regulated, and simulated with efficiency. The performance of PV systems is greatly impacted by the fluctuation and occasionally restricted accessibility of model parameters, which makes it difficult to identify these characteristics over time. To extract the features of solar modules and build highly accurate models for PV system modelling, control, and optimisation, current-voltage data collecting is essential. To overcome these difficulties, the modified particle swarm optimization rat search algorithm is presented in this manuscript. The modified rat search algorithm is incorporated to increase the PSO algorithm's accuracy and efficiency, which leads to better outcomes. The RSA mechanism increases both the population's diversity and the quality of exploration. For triple diode model of both monocrystalline and polycrystalline, PSORSA has showed exceptional performance in comparison to other algorithm i.e. RMSE for monocrystalline is 3.21E-11 and for polycrystalline is 1.86E-11. Similar performance can be observed from the PSORSA for four diode model i.e. RMSE for monocrystalline is 4.14E-09 and for polycrystalline is 4.72E-09. The findings show that PSORSA outperforms the most advanced techniques in terms of output, accuracy, and dependability. As a result, PSORSA proves to be a trustworthy instrument for assessing solar cell and PV module data.

Photo-induced processes in photosynthesis-from femtoseconds to seconds.

Photosynthesis nourishes nearly all life on Earth. Therefore, a deeper understanding of the processes by which sunlight is converted into stored chemical energy presents an important and continuing challenge for fundamental scientific research. This Special Issue is dedicated to academician Vladimir A. Shuvalov (1943-2022). We are delighted to present 15 manuscripts in the Special Issue, including two review articles and 13 research papers. These papers are contributed by 67 authors from 8 countries, including China (9), Germany (8), Hungary (4), Italy (6), Japan (2), Russia (24), Taiwan (9), and USA (5). This Special Issue provides some of the recent updates on the dynamical aspects of the initial steps of photosynthesis, including excitation energy transfer, electron transport, and dissipation of energy across time domains from femtoseconds to seconds. We hope that the readers will benefit from the work presented in this Special Issue in honor of Prof. Shuvalov in many ways. We hope that the Special Issue will provide a valued resource to stimulate research efforts, initiate potential collaboration, and promote new directions in the photosynthesis community.

Calculation of solar ultraviolet influx in the eye considering the field of view and pupillary dilation due to sunglasses.

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

Erupción fija por luz solar, una serie de 13 casos en Bogotá, Colombia / Fixed Sunlight Eruption: A Series of 13 Cases in Bogotá, Columbia

Desde 1975 se han publicado algunos casos que asocian la radiación ultravioleta como un desencadenante de erupciones cutáneas fijas (erupción o exantema fijo por luz solar o síndrome de fotosensibilidad localizada de amplio espectro). Describimos los casos de 13 pacientes con esta dermatosis, 4 varones (30,8%) y 9 mujeres (69,2%), con edades comprendidas entre los 28 y los 56 años, atendidos en un centro de referencia en dermatología en Bogotá, Colombia. Las lesiones se localizaron en la cara interna de los muslos, los glúteos, la región poplítea, la axilar anterior y posterior y el dorso de los pies. La prueba de fotoprovocación logró la reproducción de las lesiones en todos los casos en las áreas afectadas y la histopatología reveló cambios similares a los descritos en los eritemas fijos por medicamentos. Esta enfermedad podría corresponder a un subtipo de erupción fija, aunque no se descarta que sea una dermatosis diferente con una patogenia común.(AU)

Few reports describing an association between UV radiation and fixed skin eruptions have been published since 1975. These reactions have received various names, including fixed sunlight eruption, fixed exanthema due to UV radiation, and broad-spectrum abnormal localized photosensitivity syndrome. We present a series of 13 patients (4 men [30.8%] and 9 women [69.2%]) aged between 28 and 56 years who were evaluated for fixed eruptions induced by UV radiation at a dermatology referral hospital in Bogotá, Colombia. The lesions were located on the inner thighs, buttocks, popliteal region, anterior and posterior axilla, and dorsum of the feet. Photoprovocation reproduced lesions in all the affected areas, and histopathology showed changes similar to those seen in fixed drug eruptions. While these UV-provoked reactions may be a type of fixed skin eruption, we cannot rule out that they may also be a distinct condition that simply shares a pathogenic mechanism with fixed eruptions.(AU)

[Translated article] Fixed Sunlight Eruption: A Series of 13 Cases in Bogotá, Colombia / Erupción fija por luz solar, una serie de 13 casos en Bogotá, Colombia

Desde 1975 se han publicado algunos casos que asocian la radiación ultravioleta como un desencadenante de erupciones cutáneas fijas (erupción o exantema fijo por luz solar o síndrome de fotosensibilidad localizada de amplio espectro). Describimos los casos de 13 pacientes con esta dermatosis, 4 varones (30,8%) y 9 mujeres (69,2%), con edades comprendidas entre los 28 y los 56 años, atendidos en un centro de referencia en dermatología en Bogotá, Colombia. Las lesiones se localizaron en la cara interna de los muslos, los glúteos, la región poplítea, la axilar anterior y posterior y el dorso de los pies. La prueba de fotoprovocación logró la reproducción de las lesiones en todos los casos en las áreas afectadas y la histopatología reveló cambios similares a los descritos en los eritemas fijos por medicamentos. Esta enfermedad podría corresponder a un subtipo de erupción fija, aunque no se descarta que sea una dermatosis diferente con una patogenia común.(AU)

Few reports describing an association between UV radiation and fixed skin eruptions have been published since 1975. These reactions have received various names, including fixed sunlight eruption, fixed exanthema due to UV radiation, and broad-spectrum abnormal localized photosensitivity syndrome. We present a series of 13 patients (4 men [30.8%] and 9 women [69.2%]) aged between 28 and 56 years who were evaluated for fixed eruptions induced by UV radiation at a dermatology referral hospital in Bogotá, Colombia. The lesions were located on the inner thighs, buttocks, popliteal region, anterior and posterior axilla, and dorsum of the feet. Photoprovocation reproduced lesions in all the affected areas, and histopathology showed changes similar to those seen in fixed drug eruptions. While these UV-provoked reactions may be a type of fixed skin eruption, we cannot rule out that they may also be a distinct condition that simply shares a pathogenic mechanism with fixed eruptions.(AU)

Current insights and future perspectives of ultraviolet radiation (UV) exposure: Friends and foes to the skin and beyond the skin.

Ultraviolet (UV) radiation is ubiquitous in the environment, which has been classified as an established human carcinogen. As the largest and outermost organ of the body, direct exposure of skin to sunlight or UV radiation can result in sunburn, inflammation, photo-immunosuppression, photoaging and even skin cancers. To date, there are tactics to protect the skin by preventing UV radiation and reducing the amount of UV radiation to the skin. Nevertheless, deciphering the essential regulatory mechanisms may pave the way for therapeutic interventions against UV-induced skin disorders. Additionally, UV light is considered beneficial for specific skin-related conditions in medical UV therapy. Recent evidence indicates that the biological effects of UV exposure extend beyond the skin and include the treatment of inflammatory diseases, solid tumors and certain abnormal behaviors. This review mainly focuses on the effects of UV on the skin. Moreover, novel findings of the biological effects of UV in other organs and systems are also summarized. Nevertheless, the mechanisms through which UV affects the human organism remain to be fully elucidated to achieve a more comprehensive understanding of its biological effects.

Simulated sunlight/periodate-triggered formation of toxic halogenated bisphenols in highly saline water.

Periodate (PI)-based oxidation using the activators, such as metal ions and light irradiation, has emerged as a feasible treatment strategy for the effective remediation of contaminated water and wastewater. Given the pervasive nature of PI residues and solar exposure during application, the role of solar light in remediating the challenging highly saline water matrices needs to be elucidated. In this study, bisphenol A (BPA) was selected as the targeted micropollutant, which can be efficiently eliminated by the simulated sunlight (SSL)/PI system in the presence of high-level Cl- (up to 846.0 mM) at pH 7.0. The presence of different background constituents of water, such as halides, nitrate, and dissolved organic matter, had no effect, or even accelerated BPA abatement. Particularly, the ubiquitous Br- or I- appreciably enhanced the BPA transformation efficiency, which may be ascribed to the generation of high-selective reactive HOBr or HOI. The in silico predictions suggested that the transformation products generated by halide-mediated SSL/PI systems via halogen substitutions showed greater persistence, bioaccumulation, and aquatic toxicity than BPA itself. These findings highlighted a widespread phenomenon during PI-based oxidative treatment of highly saline water, which needs special attention under solar light illumination.

Exploring effective light spectral conversion techniques for enhanced production of Spirulina-derived blue pigment protein, c-phycocyanin.

Spirulina is a promising feedstock for c-phycocyanin, a blue pigment-protein, commercially incorporated in many food products for its desirable bright blue attributes, exceptional bioavailability, and inherent therapeutic properties. Remarkably, enhancing c-phycocyanin synthesis in Spirulina would facilitate economic viability and sustainability at large-scale production, as the forecasted market value is $ 409.8 million by 2030. Notably, the lighting source plays a key role in enhancing c-phycocyanin in Spirulina, and thus, strategies to filter/concentrate the photons of respective wavelengths, influencing light spectra, are beneficial. Enveloping open raceway ponds and greenhouses by luminescent solar concentrators and light filtering sheets enables solar spectral conversion of the sunlight at desirable wavelengths, emerges as a promising strategy to enhance synthesis of c-phycocyanin in Spirulina. Nevertheless, the conduction of techno-economic assessments and evaluation of scalability at large-scale cultivation of Spirulina are essential for the real-time implementation of lighting strategies.

Effective-diode-based analysis of industrial solar photovoltaic panel by utilizing novel three-diode solar cell model against conventional single and double solar cell.

Currently, the majority of the country has moved to renewable energy sources for electricity generation, and power companies are concentrating their efforts on renewable resources. Solar, wind, hydropower, and biomass are examples of renewable resources; of these, due to a lack of non-renewable resources, the solar industry is expanding. All year long, solar electricity is available, and it creates a calm, quiet atmosphere. The majority of large and small companies, as well as individual consumers, have shifted to PV solar cells for electricity generation. A trustworthy and precise simulation design of a photovoltaic system prior to installation is required to predict a photovoltaic system's performance. The current research aims to build models for solar PV systems with one, two, and three diodes and determine which model is most appropriate for each environmental circumstance to forecast performance accurately. By contrasting the experimental data of solar panel with simulated results of single-, double-, and triple-diode models, this study examines the accuracy of each model. These models' comparative performance study has been done using the MATLAB/Simulink, taking into account the influence of changing model parameters and the performance of the models under varying climatic circumstances. These models, despite their simplicity, are quite sensitive and react to even a little change in temperature and irradiance. Under conditions of low solar irradiance or shading conditions, three-diode photovoltaic models are shown to be more accurate. We can forecast the power output of solar photovoltaic systems under changeable input circumstances by understanding the I-V curves with the help of the performance assessment of the models used in this work.

Understanding microplastic aging driven by photosensitization of algal extracellular polymeric substances.

The aging of microplastics (MPs) is extremely influenced by photochemically-produced reactive intermediates (PPRIs), which are mediated by natural photosensitive substances. Algal extracellular polymeric substances (EPS) can produce PPRIs when exposed to sunlight. Nonetheless, the specific role of EPS in the aging process of MPs remains unclear. This work systematically explored the aging process of polystyrene (PS) MPs in the EPS secreted by Chlorella vulgaris under simulated sunlight irradiation. The results revealed that the existence of EPS accelerated the degradation of PS MPs into particles with sizes less than 1 µm, while also facilitating the formation of hydroxy groups on the surface. The release rate of dissolved organic matter (DOM) from PS MPs was elevated from 0.120 mg·L-1·day-1 to 0.577 mg·L-1·day-1. The primary factor contributing to the elevated levels of DOM was humic acid-like compounds generated through the breakdown of PS. EPS accelerated the aging process of PS MPs by primarily mediating the formation of triplet excited states (3EPS*), singlet oxygen (1O2), and superoxide radicals (O2∙-), resulting in indirect degradation. 3EPS* was found to have the most substantial impact. This study makes a significant contribution to advance understanding of the environmental fate of MPs in aquatic environments impacted by algal blooms.

Beyond the Tropics: Unraveling the Complex Relationship between Sun Exposure, Dietary Intake, and Vitamin D Deficiency in Coastal Malaysians.

Despite Malaysia's year-round sunny climate, vitamin D deficiency is surprisingly common among Malaysians. However, we hypothesise that vitamin D levels among coastal populations are above average. Thus, we aim to investigate vitamin D levels and correlate them with the potential contributing factors from three selected coastal villages in Johor, Melaka, and Negeri Sembilan. Convenient sampling was employed to recruit 120 Malay male and female participants, and dried blood spots (DBS) were obtained to measure 25 (OH) vitamin D3 levels via immunoassay. Participants also completed two questionnaires: the Sun Exposure and Protection Index (SEPI) and a validated food frequency questionnaire for Malaysians. The participant pool comprised 35.20% males and 64.80% females who completed all questionnaires and underwent DBS sampling. Our analysis revealed a significant difference (p < 0.05) based on skin tones, impacting various facets of the SEPI, including sunscreen usage, protective clothing utilisation, and the adoption of protective headwear. Furthermore, gender emerged as another pivotal factor, demonstrating significant distinctions in these SEPI components. Nevertheless, there is a weak correlation between SEPI scores and vitamin D levels. Subsequent regression analysis did produce statistically significant results (p = 0.018), yet the associated low R2 value indicated a weak correlation between dietary vitamin D intake that impacts vitamin D levels. In conclusion, our preliminary findings indicate that sun exposure and dietary factors are not the sole determinants of 25-OH vitamin D3 levels. However, we require more samples from various coastal locations for a definitive justification.