Search

ABSTRACT The marine microalga Emiliania huxleyi is widely distributed in the surface oceans and is prone to infection by coccolithoviruses that can terminate its blooms. However, little is known about how global change factors like solar UV radiation (UVR) and ocean warming affect the host‐virus interaction. We grew the microalga at 2 temperature levels with or without the virus in the presence or absence of UVR and investigated the physiological and transcriptional responses. We showed that viral infection noticeably reduced photosynthesis and growth of the alga but was less harmful to its physiology under conditions where UVR influenced viral DNA expression. In the virus‐infected cells, the combination of UVR and warming (+4°C) led to a 13‐fold increase in photosynthetic carbon fixation rate, with warming alone contributing a change of about 5–7‐fold. This was attributed to upregulated expression of genes related to carboxylation and light‐harvesting proteins under the influence of UVR, and to warming‐reduced infectivity. In the absence of UVR, viral infection downregulated the metabolic pathways of photosynthesis and fatty acid degradation. Our results suggest that solar UV exposure in a warming ocean can reduce the severity of viral attack on this ecologically important microalga, potentially prolonging its blooms. [ABSTRACT FROM AUTHOR]

The article discusses the results of an international survey on sun exposure behaviors and knowledge among outdoor workers in 17 countries. The study reveals that outdoor workers are at a higher risk of skin health issues due to sun exposure, with a significant disparity between their risk level and actual sun protection practices. Factors influencing sun protection measures among outdoor workers include awareness, attitudes, workplace policies, and access to resources. The findings emphasize the importance of public health measures and workplace policies to address UV-related risks for outdoor workers. [Extracted from the article]

Summary: The first step in carbon (C) turnover, where senesced plant biomass is converted through various pathways into compounds that are released to the atmosphere or incorporated into the soil, is termed litter decomposition. This review is focused on recent advances of how solar radiation can affect this important process in terrestrial ecosystems. We explore the photochemical degradation of plant litter and its consequences for biotic decomposition and C cycling. The ubiquitous presence of lignin in plant tissues poses an important challenge for enzymatic litter decomposition due to its biological recalcitrance, creating a substantial bottleneck for decomposer organisms. The recognition that lignin is also photolabile and can be rapidly altered by natural doses of sunlight to increase access to cell wall carbohydrates and even bolster the activity of cell wall degrading enzymes highlights a novel role for lignin in modulating rates of litter decomposition. Lignin represents a key functional connector between photochemistry and biochemistry with important consequences for our understanding of how sunlight exposure may affect litter decomposition in a wide range of terrestrial ecosystems. A mechanistic understanding of how sunlight controls litter decomposition and C turnover can help inform management and other decisions related to mitigating human impact on the planet. [ABSTRACT FROM AUTHOR]

The study examined the photo-stability of the thermal control coating (TCC), a class of "Optical Solar Reflectors", used in spacecrafts. This TCC is achieved by applying a layer of dielectric ceramic paste (DCP) onto the substrate using a printer (PCB printing). The DCP was prepared from filler (ground Al 2 O 3 ceramic) and solvent with thickener (terpineol with ethylcellulose). The coating obtained by high-temperature firing (T = 850 оC, 2 h) has high reflectivity in the solar range of the spectrum (0.2–2.5 μm) with the solar absorptance (α s) of DCP equal to 0.143. It has high adhesion and photo-stability that exceeds photo-stability parameters of ZnO, TiO 2 , BaSO 4 , and CaSiO 3 pigments. The developed coating can be recommended not only as a TCC for spacecrafts, but also as a protective or dielectric layer in manufacturing of printed circuit boards in various fields of technology, where increased resistance to solar radiation or its ultraviolet region is required. [ABSTRACT FROM AUTHOR]

Ultraviolet solar radiation at the Earth's surface significantly impacts both human health and ecosystems. A biologically effective daily radiant exposure (BEDRE) model is proposed for various biological processes with an analytical formula for its action spectrum. The following processes are considered: erythema formation, previtamin D3 synthesis, psoriasis clearance, and inactivation of SARS-CoV-2 virions. The BEDRE model is constructed by multiplying the synthetic BEDRE value under cloudless conditions by a cloud modification factor (CMF) parameterizing the attenuation of radiation via clouds. The CMF is an empirical function of the solar zenith angle (SZA) at midday and the daily clearness index from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) measurements on board the second-generation Meteosat satellites. Total column ozone, from MERRA-2 reanalysis, is used in calculations of clear-sky BEDRE values. The proposed model was trained and validated using data from several European ground-based spectrophotometers and biometers for the periods 2014–2023 and 2004–2013, respectively. The model provides reliable estimates of BEDRE for all biological processes considered. Under snow-free conditions and SZA < 45° at midday, bias and standard deviation of observation-model differences are approximately ±5% and 15%, respectively. The BEDRE model can be used as an initial validation tool for ground-based UV data. [ABSTRACT FROM AUTHOR]

Melatonin, a product of tryptophan metabolism via serotonin, is a molecule with an indole backbone that is widely produced by bacteria, unicellular eukaryotic organisms, plants, fungi and all animal taxa. Aside from its role in the regulation of circadian rhythms, it has diverse biological actions including regulation of cytoprotective responses and other functions crucial for survival across different species. The latter properties are also shared by its metabolites including kynuric products generated by reactive oxygen species or phototransfomation induced by ultraviolet radiation. Vitamins D and related photoproducts originate from phototransformation of ∆5,7 sterols, of which 7‐dehydrocholesterol and ergosterol are examples. Their ∆5,7 bonds in the B ring absorb solar ultraviolet radiation [290–315 nm, ultraviolet B (UVB) radiation] resulting in B ring opening to produce previtamin D, also referred to as a secosteroid. Once formed, previtamin D can either undergo thermal‐induced isomerization to vitamin D or absorb UVB radiation to be transformed into photoproducts including lumisterol and tachysterol. Vitamin D, as well as the previtamin D photoproducts lumisterol and tachysterol, are hydroxylated by cyochrome P450 (CYP) enzymes to produce biologically active hydroxyderivatives. The best known of these is 1,25‐dihydroxyvitamin D (1,25(OH)2D) for which the major function in vertebrates is regulation of calcium and phosphorus metabolism. Herein we review data on melatonin production and metabolism and discuss their functions in insects. We discuss production of previtamin D and vitamin D, and their photoproducts in fungi, plants and insects, as well as mechanisms for their enzymatic activation and suggest possible biological functions for them in these groups of organisms. For the detection of these secosteroids and their precursors and photoderivatives, as well as melatonin metabolites, we focus on honey produced by bees and on body extracts of Drosophila melanogaster. Common biological functions for melatonin derivatives and secosteroids such as cytoprotective and photoprotective actions in insects are discussed. We provide hypotheses for the photoproduction of other secosteroids and of kynuric metabolites of melatonin, based on the known photobiology of ∆5,7 sterols and of the indole ring, respectively. We also offer possible mechanisms of actions for these unique molecules and summarise differences and similarities of melatoninergic and secosteroidogenic pathways in diverse organisms including insects. [ABSTRACT FROM AUTHOR]

Unlike stratospheric ozone (O3), which is beneficial for Earth due to its capacity to screen the surface from solar ultraviolet radiation, tropospheric ozone poses a number of health and environmental issues. It has multiple effects that drive anthropogenic climate change, ranging from pure radiative forcing to a reduction of carbon sequestration potential in plants. In the central Mediterranean, which itself represents a hotspot for climate studies, multi-year data on surface ozone were analyzed at the Lamezia Terme (LMT) WMO/GAW coastal observation site, located in Calabria, Southern Italy. The site is characterized by a local wind circulation pattern that results in a clear differentiation between Western-seaside winds, which are normally depleted in pollutants and GHGs, and Northeastern-continental winds, which are enriched in these compounds. This study is the first detailed attempt at evaluating ozone concentrations at LMT and their correlations with meteorological parameters, providing new insights into the source of locally observed tropospheric ozone mole fractions. This research shows that surface ozone daily and seasonal patterns at LMT are "reversed" compared to the patterns observed by comparable studies applied to other parameters and compounds, thus confirming the general complexity of anthropogenic emissions into the atmosphere and their numerous effects on atmospheric chemistry. These observations could contribute to the monitoring and verification of new regulations and policies on environmental protection, cultural heritage preservation, and the mitigation of human health hazards in Calabria. [ABSTRACT FROM AUTHOR]

Recent years have received huge attention towards monitoring solar ultraviolet radiation due to ozone depletion caused by industrialization and urbanization. Ozone layer is a main significant constituent of the stratosphere and makes life possible on the earth's surface by absorbing the hazardous UV radiation. Adverse effects of UV radiations can be seen in different chemical and biological processes of plants and animals, it damages aquatic life, effects conservation and durability of materials and even human health and also shows its impact on global energy balance and climate change. Light-exposed tissues effected by photo oxidative stress causes and promotes diseases, including skin cancer, cataract and age-related macular degeneration. Ultraviolet (UV) radiation potentially damages the skin, the immune system and structures of the eye. Chronic UV exposure affects the cornea and lens, making effective UV protection crucial for all age groups. Monitoring of solar UV-B and UV-E radiations were performed by measuring the intensities of solar UV radiations using Kipps & Zonen radiometer sensors having spectral sensitivity. In this piece of work, three sites of Uttarakhand were selected for measurement of solar UVB and UV-E radiation and average summer peak of ultraviolet (ASPUV) and average winter peak ultraviolet (AWPUV) were calculated. Altitudinal, monthly and diurnal variations were observed and average summer and winter peak value were calculated. Natural solar UV-B level was minimum in January and maximum in months of June to September. It was found that the intensity of UV-B increases with increase in altitude and also sun's position, altitude, latitude, climate, pollution, dust and cloud affect the solar UV radiation. [ABSTRACT FROM AUTHOR]

Information on the detection of the presence and potential for degradation of synthetic polymers (SPs) under various environmental conditions is of increasing interest and concern to a wide range of specialists. At this stage, there is a need to understand the relationship between the main participants in the processes of (bio)degradation of SPs in various ecosystems (reservoirs with fresh and sea water, soils, etc.), namely the polymers themselves, the cells of microorganisms (MOs) participating in their degradation, and humic substances (HSs). HSs constitute a macrocomponent of natural non-living organic matter of aquatic and soil ecosystems, formed and transformed in the processes of mineralization of bio-organic substances in environmental conditions. Analysis of the main mechanisms of their influence on each other and the effects produced that accelerate or inhibit polymer degradation can create the basis for scientifically based approaches to the most effective solution to the problem of degradation of SPs, including in the form of microplastics. This review is aimed at comparing various aspects of interactions of SPs, MOs, and HSs in laboratory experiments (in vitro) and environmental investigations (in situ) aimed at the biodegradation of polymers, as well as pollutants (antibiotics and pesticides) that they absorb. Comparative calculations of the degradation velocity of different SPs in different environments are presented. A special place in the analysis is given to the elemental chemical composition of HSs, which are most successfully involved in the biodegradation of SPs. In addition, the role of photo-oxidation and photoaging of polymers under the influence of the ultraviolet spectrum of solar radiation under environmental conditions on the (bio)degradation of SPs in the presence of HSs is discussed. [ABSTRACT FROM AUTHOR]

Objective: More than 95% of melanomas in Australia are caused by UV radiation from the sun. Young adults are particularly at risk, with 18–24-yearolds spending more time in the sun and protecting their skin less than older adults. A new mass media campaign was delivered in New South Wales, Australia, to motivate this hard-to-reach group to protect their skin from harmful UV radiation. This paper shares learnings from this campaign for public health educators working across diverse fields. Program: Guided by audience research and testing, the campaign combined fear-based and self-efficacy messaging. UV radiation was portrayed as arrows descending from the sky, transforming it into a visible and ever-present threat. High-reach channels such as cinema, outdoor advertising, online videos, audio apps and social media were used to reach the audience. Methods: The campaign was evaluated through an online tracking survey (n = 750, 18–24-year-olds) measuring prompted recognition, message take-out, key diagnostics, and self-reported sun protection intentions and behaviours. Results: The evaluation found that 57% of survey participants recognised the campaign when prompted. Among those that recognised the campaign, 76% said they had used sun protection when outdoors over the summer campaign period (vs 64% of non-recognisers, p < 0.05), and 45% said they had adopted at least three of the five sun protection behaviours (Slip, Slop, Slap, Seek and Slide) ‘always’ or ‘often’ (vs. 36% of non-recognisers, p < 0.05). Lessons learnt: A mass-media campaign that aimed to elicit emotional (fear) and cognitive (perceived efficacy) responses and which drew upon social and heuristic cues was associated with greater self-reported sun protection among the target audience. Delivering a combination of message strategies simultaneously within a campaign tailored to young adults may be more effective than adopting a more singular focus. [ABSTRACT FROM AUTHOR]

Context. On 2022 May 4, an M5.7 flare erupted in the active region NOAA 13004, which was the target of a coordinated campaign between GREGOR, IRIS, Hinode, and ground-based instruments at the Ondřejov observatory. A flare kernel located at the edge of a pore was co-observed by the IRIS slit and GREGOR HiFI+ imagers. Aims. We investigated the flare continuum enhancement at different wavelength ranges in order to derive the temperature of the chromospheric layer heated during the flare. Methods. All datasets were aligned to IRIS slit-jaw images. We selected a pixel along the IRIS slit where the flare kernel was captured and evaluated multi-wavelength light curves within it. We defined a narrow IRIS near-UV band that comprises only continuum emission. The method, which assumes that the flare continuum enhancement is due to optically thin emission from hydrogen recombination processes, was applied to obtain a lower limit on the temperature in the layer where the continuum enhancement was formed. Results. We determined a lower limit for the temperature and its time evolution in the chromospheric layer heated during the flare in the range of (3–15) ×103 K. The mean electron density in that layer was estimated to be ∼1 × 1013 cm−3. Conlcusions. Multi-wavelength flare co-observations are a rich source of diagnostics. Due to the rapidly evolving nature of flares, the sit-and-stare mode is key to achieving a high temporal cadence that allows one to thoroughly analyse the same flare structure. [ABSTRACT FROM AUTHOR]

Context. Solar active regions (ARs) are often surrounded by dark large areas of reduced emission compared to the quiet Sun, observed at various wavelengths corresponding to the chromosphere, transition region (TR), and corona, known as dark halos (DHs). The mechanisms behind the darker emission of DHs remain unclear and merit a wider scope of study. Aims. This study aims to investigate for the first time the fine structure of a DH observed by the EUV High Resolution Imager (HRIEUV) on board the ESA's Solar Orbiter (SO) mission and its appearance in the TR. Aims. We utilized the extensive 1 hour dataset from SO on 19 March 2022, which includes high-resolution observations of NOAA 12967 and part of the surrounding DH. We analyzed the dynamics of the HRIEUV DH fine structure and its appearance in the HRILyα image. We also analyzed the Spectral Imaging of the Coronal Environment (SPICE) Lyβ, C III, N VI, O VI, and Ne VIII lines, which sample the TR in the log T(K) ∼ 4.0–5.8 range. This analysis was complemented with a simultaneous BLOS magnetogram taken by the High Resolution Telescope (HRT). Methods. We report the presence of a peculiar fine structure that has not been observed for the quiet Sun. It is characterized by combined bright EUV bundles and dark regions, arranged and interconnected in such a way that they cannot be clearly separated. They form a spatial continuum extending approximately radially from the AR core, suggesting a deep connection between the DH and the AR. Additionally, we find that the bright EUV bundles are observed in all the SPICE TR lines and the HRILyα band and present photospheric BLOS footprints in the HRT magnetogram. This spatial correlation indicates that the origin of the 174 Å DH may lie in the low atmosphere: the photosphere and chromosphere. [ABSTRACT FROM AUTHOR]

Context. The relation between the intensity of chromospheric emissions and the photospheric magnetic field strength has been examined in several studies, but the effect of the magnetic field inclination on chromospheric emissions remains almost unexplored. Aims. We study how the inclination of the photospheric magnetic field, as measured by the full 3D magnetic vector from the Helioseismic and Magnetic Imager (HMI), affects the relationship between the magnetic field strength and the far-ultraviolet emission at around 1600 Å observed by the Atmospheric Imaging Assembly (AIA). We also study how these parameters change spatially close to the active region perimeter. Methods. We analyzed the mutual dependence of 1168 co-temporal AIA and HMI observations from 2014 to 2017. We focused on magnetically active regions outside sunspots (e.g., plages and network) close to the solar disk center. We studied how the AIA and HMI parameters change with distance from the active region perimeter. Results. The AIA 1600 emission typically decreases with increasing (more horizontal) inclination. For all inclinations, AIA 1600 emission increases with increasing magnetic field strength until saturating at some peak intensity, which depends on the cosine of the inclination, with horizontal regions saturating at lower intensities. In addition, we find that activity clusters have a narrow boundary (< 2 arcsec) in which the AIA 1600 intensity, magnetic field strength, and inclination distributions and relations differ significantly from those in the inner layers. Conclusions. This study demonstrates the significant effect that magnetic field inclination and activity cluster border regions have on chromospheric emissions. Although the observed effects are likely reduced in low-resolution observations where different regions are averaged together, a detailed study is needed to examine the emission–magnetic field relation at different resolutions. [ABSTRACT FROM AUTHOR]

Context. The slowly positively drifting bursts (SPDBs) are rarely observed in radio emission of solar flares. Aims. To understand how the SPDBs are generated, we studied the radio observations at 600–5000 MHz together with the imaging observations made in ultraviolet (UV) and extreme ultraviolet (EUV) during the SPDB-rich C8.7 flare of 2014 May 10 (SOL2014-05-10T0702). Methods. Because the SPDBs propagate towards locations of higher plasma density, we studied their associations with individual flare kernels, located either within the flare core itself, or distributed at longer distances, but connected to the flaring region by large-scale hot loops. For each kernel we constructed light curves using 1600 Å and 304 Å observations and compared these light curves with the temporal evolution of radio flux at 1190 MHz, representing all observed groups of SPDBs. We also analysed the UV/EUV observations to understand the evolution of magnetic connectivity during the flare. Results. The flare starts with a growing hot sigmoid observed in 131 Å. As the sigmoid evolves, it extends to and interacts with a half dome present within the active region. The evolving sigmoid reconnects at the respective hyperbolic flux tube, producing large-scale magnetic connections and an EUV swirl. Three groups of SPDBs are observed during this large-scale magnetic reconnection, along with a group of narrow-band type III bursts. The light curves of a kernel corresponding to the footpoint of spine line analogue show good agreement with the radio flux at 1190 MHz, indicating that the SPDBs are produced by the large-scale magnetic reconnection at the half dome. In addition, one of the kernels appeared in the neighbouring active region and also showed a similar evolution to the radio flux, implying that beams of accelerated particles can synchronize radio and UV/EUV light curves across relatively large distances. [ABSTRACT FROM AUTHOR]

Context. The study of quasi-periodic pulsations (QPPs) is a key diagnostic of intermittent or periodic energy releases during solar flares. Aims. We investigated the intermittent energy-releasing processes by analyzing the long-period pulsations during a C2.8 flare on 2023 June 3. Methods. The solar flare was simultaneously observed by the solar X-ray detector on board the Macau Science Satellite-1B, the Geostationary Operational Environmental Satellite, the Chinese Hα Solar Explorer, the Expanded Owens Valley Solar Array, the Atmospheric Imaging Assembly, and the Extreme Ultraviolet Variability Experiment for the Solar Dynamics Observatory. Results. The C2.8 flare shows three successive and repetitive pulsations in soft X-ray (SXR) and high-temperature extreme ultraviolet (EUV) emissions, which may imply three episodes of energy releases during the solar flare. The QPP period is estimated to be as long as ∼7.5 minutes. EUV imaging observations suggest that these three pulsations come from the same flare area dominated by the hot loop system. Conversely, the flare radiation in wavelengths of radio/microwave, low-temperature EUV, ultraviolet (UV), and Hα only reveals the first pulsation, which may be associated with nonthermal electrons accelerated by magnetic reconnection. The other two pulsations in wavelengths of SXR and high-temperature EUV might be caused by the loop-loop interaction. Conclusions. Our observations indicate that the three episodes of energy releases during the C2.8 flare are triggered by different mechanisms, namely the accelerated electron via magnetic reconnection, and the loop-loop interaction in a complicated magnetic configuration. [ABSTRACT FROM AUTHOR]

The behavior of ozone gas (O 3) in the atmosphere varies according to the region of the globe. Its formation occurs mainly in the tropical stratosphere through the photodissociation of molecular oxygen with the aid of the incidence of ultraviolet solar radiation. Still, the highest concentrations of O 3 content are found in high-latitude regions (poles) due to the Brewer–Dobson circulation, a large-scale circulation that takes place from the tropics to the pole in the winter hemisphere. This work presents a multi-instrumental analysis at two Brazilian sites, a subtropical one (Santa Maria – 29.72° S, 53.41° W) and an equatorial one (Natal – 5.4° S, 35.4° W), to investigate ozone distributions in terms of vertical profiles (2002–2020) and total abundance in terms of total columns of ozone (1979–2020). The study is based on the use of ground-based and satellite observations. Ozone profiles over Natal, from the ground up to the mesosphere, are obtained by radiosonde experiments (0–30 km) in the framework of the SHADOZ program and by satellite measurements from the SABER instrument (15–60 km). This enabled the construction of a continuous time series for ozone, including monthly values and climatological trends. There is a good agreement between the two measurements in the common observation layer, mainly for altitudes above 20 km. Below 20 km, SABER ozone profiles showed high variability and overestimated ozone mixing ratios by over 50 %. Dynamic and photochemical effects can interfere with O 3 formation and distribution along higher latitudes through the Brewer–Dobson circulation. The measurements of the total ozone columns used are in good agreement with each other (TOMS/OMI × Dobson for Natal and TOMS/OMI × Brewer for Santa Maria) in time and space, in line with previous studies for these latitudes. Wavelet analysis was used over 42 years. The investigation revealed a significant annual cycle in both data series for both sites. The study highlighted that the quasi-biennial oscillation (QBO) plays a significant role in the variability of stratospheric ozone at the two study sites – Natal and Santa Maria. The QBO's contribution was found to be stronger at the Equator (Natal) than at the subtropics (Santa Maria). Additionally, the study showed that the 11-year solar cycle also has a significant impact on ozone variability at both locations. Given the study latitudes, the ozone variations observed at the two sites showed different patterns and amounts. Only a limited number of studies have been conducted on stratospheric ozone in South America, particularly in the region between the Equator and the subtropics. The primary aim of this work is to investigate the behavior of stratospheric ozone at various altitudes and latitudes using ground-based and satellite measurements in terms of vertical profiles and total columns of ozone. [ABSTRACT FROM AUTHOR]

Waves play an important role in the heating of solar atmosphere; however, observations of wave propagation and damping from the solar photosphere to corona through chromosphere and transition region are very rare. Recent observations have shown propagation of 3-min slow magnetoacoustic waves (SMAWs) along fan loops from the solar photosphere to corona. In this work, we investigate the role of area divergence and frequencies on the damping of SMAWs propagating from the photosphere to the corona along several fan loops rooted in the sunspot umbra. We study the Fourier power spectra of oscillations along fan loops at each atmospheric height which showed significant enhancements in 1–2, 2.3–3.6, and 4.2–6 min period bands. Amplitude of intensity oscillations in different period bands and heights are extracted after normalizing the filtered light curves with low-frequency background. We find damping of SMAW energy flux propagating along the fan loop 6 with damping lengths |$\approx 170$| and |$\approx 208$| km for 1.5- and 3-min period bands. We also show the decay of total wave energy content with height after incorporating area divergence effect, and present actual damping of SMAWs from photosphere to corona. Actual damping lengths in this case increases to |$\approx 172$| and |$\approx 303$| km for 1.5- and 3-min period bands. All the fan loops show such increase in actual damping lengths, and thus highlight the importance of area divergence effect. Results also show some frequency-dependent damping of SMAW energy fluxes with height where high-frequency waves are damped faster than low-frequency waves. [ABSTRACT FROM AUTHOR]

Background: Protection from solar ultraviolet radiation (UVR) is paramount in light‐skinned pig breeds such as Yorkshire or Landrace to avoid sunburn. Objectives: Determination of the UVR exposure of a pig and the sun protection abilities of shade cloths with different shade rates. Animals: Life‐sized plastic model of a Landrace pig. Materials and Methods: The model was equipped with 20 UVR meters at various anatomical positions that recorded the erythemal effective solar irradiance. A turntable enabled irradiation from different directions. Solar irradiance was measured in direct sunlight as well as under three shade cloths with different shade rates (50%, 75% and 90%) and a camouflage net. The sun protection factors (SPF) were determined as the ratio of unshaded‐to‐shaded measurements at the same solar elevation. The exposure ratio to ambient (ERTA) was calculated for each body site with respect to ambient irradiance. It allows determination of when pigs are at risk of sunburn and protection is needed. Results: The calculated ERTA values show that some body parts may receive higher values than ambient UVR. Measurements showed that the SPF of shade cloths depends on textile denseness. Selected shade cloths reached values of 3.5 (shade rate 50%), 4.2 (75%) and 5.8 (90%). Protection by the camouflage net was poor. The highest SPF was gained on body sides where ERTA was highest. Conclusions and Clinical Relevance: Shade cloths can protect all body sites effectively and vulnerable sites in particular. The results of our study enable an estimation of when pigs are at risk of sunburn and provide quantitative metrics for sun protection. This allows effective prevention of UVR‐caused skin damage and secondary disorders. [ABSTRACT FROM AUTHOR]

The explosive release of energy in the solar atmosphere is driven magnetically, but the mechanisms that trigger the onset of the eruption remain controversial. In the case of flares and coronal mass ejections (CMEs), ideal or non-ideal instabilities usually occur in the corona, but it is difficult to obtain direct observations and diagnostics there. To overcome this difficulty, we analyze observational signatures in the upper chromosphere or transition region, particularly brightening and dimming at the base of coronal magnetic structures. In this paper, we examine the time evolution of spatially resolved light curves in two eruptive flares and identify a variety of tempo-spatial sequences of brightening and dimming, such as dimming followed by brightening and dimming preceded by brightening. These brightening--dimming sequences are indicative of the configuration of energy release in the form of plasma heating or bulk motion. We demonstrate the potential of using these analyses to diagnose the properties of magnetic reconnection and plasma expansion in the corona during the early stages of the eruption. [ABSTRACT FROM AUTHOR]

The district of Perus, located in the city of São Paulo, Brazil, is renowned for its weathered granitic-pegmatitic masses, which harbor a significant number of uraniferous minerals that contribute to ionizing radiation levels up to 20 times higher than the background levels. In this study, aseptically collected mineral samples from the area were utilized to isolate 15 microorganisms, which were subjected to pre-screening tests involving UV-C and UV-B radiation. The microorganisms that exhibited the highest resistance to ultraviolet (UV) radiation were selected for the construction of survival curves for UV-C, broad-band UV-B, and solar simulation resistance testing. Subsequently, the four strains that demonstrated superior survival capabilities under UV radiation exposure were chosen for 16S rRNA gene sequencing. Among these, Nocardioides sp. O4R and Nocardioides sp. MA2R demonstrated the most promising outcomes in the UV radiation resistance assessments, showcasing comparable performance to the well-established radioresistant model organism Deinococcus radiodurans. These findings underscore the potential of naturally occurring high-radiation environments as valuable resources for the investigation of UV-resistant microorganisms. Astrobiology 24, 783–794. [ABSTRACT FROM AUTHOR]

Background: Photoageing describes complex cutaneous changes that occur due to chronic exposure to solar ultraviolet radiation (UVR). The 'gold standard' for the treatment of photoaged white skin is all‐trans retinoic acid (ATRA); however, cosmetic retinol (ROL) has also proven efficacious. Recent work has identified that black skin is susceptible to photoageing, characterized by disintegration of fibrillin‐rich microfibrils (FRMs) at the dermal–epidermal junction (DEJ). However, the impact of topical retinoids for repair of black skin has not been well investigated. Objectives: To determine the potential of retinoids to repair photoaged black skin. Methods: An exploratory intervention study was performed using an in vivo, short‐term patch test protocol. Healthy but photoaged black volunteers (>45 years) were recruited to the study, and participant extensor forearms were occluded with either 0.025% ATRA (n = 6; 4‐day application due to irritancy) or ROL (12‐day treatment protocol for a cosmetic) at concentrations of 0.3% (n = 6) or 1% (n = 6). Punch biopsies from occluded but untreated control sites and retinoid‐treated sites were processed for histological analyses of epidermal characteristics, melanin distribution and dermal remodelling. Results: Treatment with ATRA and ROL induced significant acanthosis (all p < 0.001) accompanied by a significant increase in keratinocyte proliferation (Ki67; all p < 0.01), dispersal of epidermal melanin and restoration of the FRMs at the DEJ (all p < 0.01), compared to untreated control. Conclusions: This study confirms that topical ATRA has utility for the repair of photoaged black skin and that ROL induces comparable effects on epidermal and dermal remodelling, albeit over a longer timeframe. The effects of topical retinoids on black photoaged skin are similar to those reported for white photoaged skin and suggest conserved biology in relation to repair of UVR‐induced damage. Further investigation of topical retinoid efficacy in daily use is warranted for black skin. [ABSTRACT FROM AUTHOR]

The analytical study of the two-stream instability (TSI) generation is carried out in the lunar ionosphere. The solar wind is considered an electron beam, which interacts with the lunar ionosphere, generated due to the photoionization of the lunar neutrals by the extreme ultraviolet component of the solar radiation. In this interaction process, the lunar electrons constitute the background plasma as the ion population is considerably low in the lunar plasma environment. In the present study along with the non-energetic ("cold") electrons, which are in the majority, a fraction of energetic electrons ("hot") of the total lunar electron population are also considered and the fraction of energetic electrons is taken in the range of 1%–25% of the total lunar electron count. The particle-in-cell simulations suggest that the presence of energetic electrons in the lunar plasma environment hastens the electron bunching during the interaction with the incoming solar wind electrons during the TSI. The energetic electrons in the lunar plasma environment are capable of triggering non-linear phenomena, such as the generation of lunar plasma waves. The inclusion of hot electrons in the lunar plasma ambiance changes the scenario for the TSI to occur in the lunar ionosphere, and the analysis shows that it modifies the TSI dispersion relation and can have a significant impact on the growth and decay of the TSI and its threshold for generation in a lunar plasma environment. [ABSTRACT FROM AUTHOR]

Background: Skin is an important barrier of the human body, which offers protection from pathogens, UV radiation, and chemical and mechanical injury. Solar UV radiation is the major cause of extrinsic skin aging and it leads to many acute and chronic cutaneous reactions. Dermoscope is an instrument that helps to visualize the morphological features unseen to the naked eye, using the principle of transillumination and magnification of skin. Aim and Objective: The aim of the study was to study the skin changes associated with sun exposure on the lateral and medial aspects of the forearm using dermoscope. Materials and Methods: A cross-sectional descriptive study of 82 1st-year MBBS students belonging to 18-25 years of age was conducted at Government Medical College, Thrissur, after getting ethics committee approval. Sample size calculated was 76. With the help of a questionnaire, personal details and details related to the sun exposure habits of the subjects were obtained. Dermoscopic photographs of the lateral and medial side of the forearm were taken after informed consent. Results: Chi-square test showed significant changes in pigmentation pattern and hair pattern on the lateral side of the forearm among subjects who had sun exposure for more than half an hour which was not found on the medial side. Conclusion: Photoaged skin appears coarse with uneven pigmentation. Dermoscopy allows the assessment of subtle morphological features of skin aging. Monitoring skin changes due to sun exposure among our population helps in the early identification of abnormal patterns with sun exposure which needs immediate medical attention. [ABSTRACT FROM AUTHOR]

A comprehensive statistical study is conducted on O+ and H+ outflows obtained from the TEAMS/FAST data during the 23rd solar cycle (1996–2007). The study investigates interhemispheric asymmetry in ionospheric outflows during local summer, winter, and equinox seasons. Data are classified into two distinct periods: the pre‐storm and geomagnetic storm phases. Numerous statistical asymmetries are identified. The findings indicate that the dayside cusp consistently demonstrates more outflow rates of O+ and H+ in the northern hemisphere than southern hemisphere during geomagnetic storms in all seasons as well as during the pre‐storm period in the summer season with the exception of H+ during summer storms. Conversely, the nightside O+ and H+ outflow rates are higher in the southern hemisphere during pre‐storm and storm periods in the summer season. Additionally, the dawnside and duskside outflow rates of O+ and H+ are predominantly stronger in the southern hemisphere. Plain Language Summary: The Earth's hemispheres receive different solar extreme ultraviolet radiation levels in different local seasons. In addition, there is a displacement between Earth's magnetic and geographic poles. Both mentioned factors cause interhemispheric asymmetries in ionospheric parameters. For the first time, this study investigates asymmetry in O+ and H+ ionospheric outflows between the northern and southern hemispheres by focusing on similar local seasons with comparable solar radiation levels. Data from the FAST/Time‐of‐flight Energy Angle Mass Spectrograph (TEAMS) instrument (1996–2007) are used for storms and pre‐storms. Hemispherical ionospheric outflows are categorized into summer, winter, and equinox and are spatially averaged in the polar regions. Findings reveal asymmetric ion outflows between hemispheres. The dayside cusp outflows are higher in the northern hemisphere than in the southern hemisphere during geomagnetic storms in all seasons except for H+ in summer. Conversely, nightside O+ and H+ outflows are more in the southern hemisphere than in the northern hemisphere during pre‐storm and storm periods in summer. Additionally, in dawnside and duskside, O+ and H+ outflows are predominantly stronger in the southern hemisphere than in the northern hemisphere. Key Points: 11‐year statistics find the northern and southern hemispheres exhibit asymmetric ion outflow even during similar local seasonsDuring storms, the cusp dayside exhibits higher O+ and H+ outflow rates in the northern hemisphere compared to the southern hemisphereThe dawnside and duskside O+ and H+ outflow rates are stronger in the southern hemisphere than in the northern hemisphere [ABSTRACT FROM AUTHOR]

Context. Spectral inversions are used to analyse spectroscopic observations with the aim of deriving the physical properties of the observed plasma, such as the kinetic temperature, density, pressure, degree of ionisation, or macroscopic velocities. One of the key factors ensuring the high precision of the derived plasma properties is having accurately defined input parameters of the models on which spectral inversions rely. The illumination, which chromospheric and coronal structures receive from the solar surface (and corona), is one of the most crucial input parameters of these models. Aims. We do not perform spectral inversions in this work. Our aim is to study two important factors that contribute to the accurate definition of the incident radiation boundary conditions: the altitude above the solar surface and the dynamics of the illuminated plasma. This investigation takes into account a diverse range of solar structures from the high-rising eruptive prominences to low-lying spicules. Methods. To study the influence of the altitude and dynamics of the observed plasma on the incident radiation boundary conditions, we used geometrical principles valid for any spectral line. However, to demonstrate the strong impact of dynamics, we considered the specific case of narrow spectral lines of Mg II H&K, which are highly sensitive to the presence of velocities. Results. We argue that the altitude of the illuminated plasma strongly influences the way we need to define the incident radiation boundary conditions to achieve the most accurate results. For low-lying structures, generally below 50 000 km, the incident radiation may need to be specified directly from the composition of the portion of the solar disc that illuminates them. For high-altitude structures, generally above 300 000 km, the fraction of the solar disc illuminating the analysed plasma is large enough to be realistically approximated by the composition of the entire disc. We also show that for the narrow spectral lines, such as the Mg II H&K lines, the impact of dynamics on the incident radiation intensity and profile shapes starts from radial velocities of 30 km s−1. Such velocities are even exhibited by the fine structures of quiescent prominences and are easily exceeded in spicules or eruptive prominences. Conclusions. The two aspects of the incident radiation definition studied here are relevant for spectral inversions based on any kind of modelling approach. However, their impact on the precision of the results of spectral inversions is likely less significant than the impact of the choice of the complexity of the model geometry, for example. [ABSTRACT FROM AUTHOR]

Simple Summary: In recent decades, the use of plastic has increased exponentially. If discarded improperly, plastic waste can harm the environment and biodiversity. Under the influence of solar UV radiation, wind, currents, and other natural factors, plastic breaks down into small particles known as microplastics (MPs, <5 mm in one dimension) or nanoplastics (NPs, <100 nm). These tiny particles, which are characterized by various forms such as fragments, sheets, filaments, foam, granules, and pellets, have become a major factor in environmental pollution. Birds play an important role in the global trophic network system and are widely used as indicators of biodiversity, pollution, and environmental change. The present study aims to investigate the number of microplastics bioaccumulated in specimens of Song Thrushes (Turdus philomelos), which are migratory birds wintering in Apulia, Italy. The specimens (n = 360) were hunted in the Bari countryside and donated for research purposes by hunters. Plastic debris was detected in the stomachs of 129 and 128 birds shot in December and January. The majority of ingested MPs were fibers, followed by films, fragments, and pellets. As for color, among all the MPs found, 31.75% were red, 30.13% were black, and 25.91% were blue, while the other colors were less represented. The high contamination of thrushes confirmed the ubiquity of MPs in terrestrial ecosystems. The term microplastics (MPs) describes a heterogeneous mixture of particles that can vary in size, color, and shape. Once released into the environment, MPs have various toxicological and physical effects on wildlife. The Song Thrush (Turdus philomelos) is a migratory species, staying in Italy in late autumn and winter. The aim of this study is to assess, quantify, and characterize the presence of microplastics in Song Thrushes hunted in the Apulia region of Italy. The birds (n = 360) were hunted in the Bari countryside and donated for research purposes by hunters. MPs were classified in relation to their shape in fibers, films, fragments, and pellets; then, they were divided according to their color and the length of the particles was measured. Nikon image analysis software was applied to the litter size measurements. Of the total of 360 birds, MPs were detected in the stomachs of 129 birds shot in December and 128 birds shot in January. The majority of ingested MPs were fibers that were observed in all contaminated birds. Film fragments were observed in every contaminated specimen. Among all the MPs found, 31.75% were red, 30.13% were black, and 25.91% were blue, while the other colors were less represented. This study provides the first analysis of MPs bioaccumulation in Song Thrushes wintering in the Apulia region, and the high contamination of thrushes confirmed the ubiquity of MPs in terrestrial ecosystems. [ABSTRACT FROM AUTHOR]

The article in the Journal of Pakistan Association of Dermatologists explores the debate on whether sunlight exposure is the primary cause of skin cancers. It discusses the historical significance of sunlight, its effects on human health, and the role of sunlight in vitamin D synthesis. The article presents various perspectives on the relationship between sunlight exposure and skin cancers, highlighting factors such as melanin protection, genetic diseases, and the locations of different types of skin tumors. It concludes by suggesting the need for further research to better understand the mechanisms behind skin tumors and the role of sunlight exposure. [Extracted from the article]

Guarana seeds are typically processed using one of three drying methods: traditional sun exposure, greenhouse drying, or the alguidar oven technique. In our research, we evaluated the contents of methylxanthines and flavan‐3‐ols in sun‐ and alguidar‐dried guarana seeds from Bahia State's Low Sul Identity Territory. Caffeine, theobromine, catechin, and epicatechin were determined by high‐performance liquid chromatography with UV‐visible detection (HPLC/UV‐vis). Statistical tools, including analysis of variance (ANOVA), Tukey's test, and exploratory analysis, were employed to analyze the obtained data. Our findings indicated that the flavan‐3‐ols content in sun‐dried guarana samples was lower compared to those dried using the alguidar oven, possibly due to exposure to ultraviolet radiation from solar energy. Conversely, we observed no significant differences (p > 0.05) in the average contents of methylxanthines between the two drying methods. Our supplementary experiments involving UV‐A and UV‐C radiation lamps revealed a decreasing trend in methylxanthines and flavan‐3‐ols contents with increasing duration of UV radiation exposure. [ABSTRACT FROM AUTHOR]

Tree shade, particularly shade that obscures direct sunlight near peak periods of midday solar exposure can have a pronounced effect on potentially harmful ultraviolet radiation, and in turn, strongly influence the maximum daily UV index (UVI). In this study, the seasonal influence of tree shade on the UVI is evaluated from 210 hemispherical sky view images collected alongside public walkways and footpaths from 10 residential Brisbane suburbs. The effective sidewalk UV index is calculated underneath planted tree canopies, adjacent residential gardens, buildings and background tree species. Results are presented with respect to seasonal variations in the diurnal solar elevation for each month of the year at Brisbane's latitude. The research also examines the total reduction in UVI due to the presence of individual tree species, showing reductions in the midday UVI of up to 91% of an equivalent unimpeded sky hemisphere when overhead tree canopies are present. Important footpath tree species for peak midday UVI mitigation include Pongamia pinnata, Xanthostemon chrysanthus, Senna siamea, and Libidibia ferrea. The planting and maintenance of existing tree species already growing alongside residential Brisbane streets will improve the shade characteristics of suburbs and enhance UV protection for local residents. [ABSTRACT FROM AUTHOR]

Composite analyses of NOAA satellite‐based outgoing longwave radiation data and ERA5 reanalysis data for nearly six solar maximum periods support the existence of a response of tropical convection and precipitation to short‐term (∼27‐day) solar ultraviolet variations. Following solar UV peaks, the response consists of an increase in average convection and precipitation in the equatorial Indian Ocean and a decrease in the western and central tropical Pacific, with maximum amplitude at a lag of 4 to 8 days. The opposite occurs following short‐term solar UV minima. The observed responses are most detectable when the Madden‐Julian oscillation (MJO) is active and appear to be related to a reduced ability of the MJO to propagate across the Maritime Continent barrier following solar UV peaks relative to UV minima. A similar behavior has previously been found when the stratospheric quasi‐biennial oscillation is in its westerly phase relative to its easterly phase. Plain Language Summary: Under solar maximum conditions, active regions on the sun produce strong variations of solar ultraviolet radiation on the solar rotational time scale (∼27 days). We have analyzed data from NOAA satellites and ERA5 reanalysis for almost six solar maximum periods. The results indicate that these short‐term solar ultraviolet variations affect tropical convection and precipitation. Following a peak in solar UV radiation, there is an increase in convection and precipitation in the equatorial Indian Ocean, and a decrease in the western and central tropical Pacific, with the most significant changes occurring 4 to 8 days later. The opposite happens after solar UV minima. These effects are most noticeable when the Madden‐Julian Oscillation is active and seem linked to its inability to move across the Maritime Continent barrier after solar peaks compared to solar minima. Similar patterns have been observed with the stratospheric quasi‐biennial oscillation in its westerly phase versus its easterly phase. Key Points: Evidence of lagged responses of tropical convection and precipitation to short‐term solar UV variations is found over six solar cyclesThe responses are due to solar effects on eastward propagation of the Madden‐Julian oscillation across the Maritime Continent barrierAverage precipitation rate differences following solar peaks and minima can be more than 20% of mean daily rates [ABSTRACT FROM AUTHOR]

In budding yeast, Rad5 and Rad7-Rad16 play respective roles in the error-free post-replication repair and nucleotide excision repair of ultraviolet-induced DNA damage; however, their homologs have not yet been studied in non-yeast fungi. In the fungus Beauveria bassiana, a deficiency in the Rad7 homolog, Rad5 ortholog and two Rad16 paralogs (Rad16A/B) instituted an ability to help the insect-pathogenic fungus to recover from solar UVB damage through photoreactivation. The fungal lifecycle-related phenotypes were not altered in the absence of rad5, rad16A or rad16B, while severe defects in growth and conidiation were caused by the double deletion of rad16A and rad16B. Compared with the wild-type and complemented strains, the mutants showed differentially reduced activities regarding the resilience of UVB-impaired conidia at 25 °C through a 12-h incubation in a regime of visible light plus dark (L/D 3:9 h or 5:7 h for photoreactivation) or of full darkness (dark reactivation) mimicking a natural nighttime. The estimates of the median lethal UVB dose LD50 from the dark and L/D treatments revealed greater activities of Rad5 and Rad16B than of Rad16A and additive activities of Rad16A and Rad16B in either NER-dependent dark reactivation or photorepair-dependent photoreactivation. However, their dark reactivation activities were limited to recovering low UVB dose-impaired conidia but were unable to recover conidia impaired by sublethal and lethal UVB doses as did their photoreactivation activities at L/D 3:9 or 5:7, unless the night/dark time was doubled or further prolonged. Therefore, the anti-UV effects of Rad5, Rad16A and Rad16B in B. bassiana depend primarily on photoreactivation and are mechanistically distinct from those for their yeast homologs. [ABSTRACT FROM AUTHOR]

Melanoma, primarily caused by solar ultraviolet (UV) radiation, can be prevented by the use of sunscreens. However, the use of synthetic sunscreens raises environmental concerns. Natural compounds with antioxidant photoprotective properties and cytotoxic effects against cancer cells can be promising for the prevention and treatment of melanoma with less environmental effect. This study focuses on Melaleuca leucadendron essential oil (EO) for photoprotection and antitumor applications. EO was hydrodistilled from M. leucadendron leaves with a 0.59% yield. Gas chromatography–mass spectrometry detected monoterpenes and sesquiterpenes. Nanoemulsions were prepared with (NE-EO) and without EO (NE-B) using the phase inversion method, showing good stability, spherical or oval morphology, and a pseudoplastic profile. Photoprotective activity assessed spectrophotometrically showed that the NE-EO was more effective than NE-B and free EO. Antioxidant activity evaluated by DPPH and ABTS methods indicated that pure and nanoemulsified EO mainly inhibited the ABTS radical, showing IC50 40.72 and 5.30 µg/mL, respectively. Cytotoxicity tests on L-929 mouse fibroblasts, NGM human melanocyte, B16-F10 melanoma, and MeWo human melanoma revealed that EO and NE-EO were more cytotoxic to melanoma cells than to non-tumor cells. The stable NE-EO demonstrates potential for melanoma prevention and treatment. Further research is required to gain a better understanding of these activities. [ABSTRACT FROM AUTHOR]

Passive daytime radiative coolers (PDRCs) with exceptionally high solar reflectance and emissivity in the atmospheric window can provide sub-ambient cooling while reducing buildings' cooling energy demand. However, glare and esthetic issues limit their application to high-rise buildings while may increase the building's heating energy needs. Passive colored radiative coolers (PCRCs), based on fluorescent materials, convert part of the absorbed UV and visible solar radiation into emitted light, providing color and reducing the thermal balance of the materials and the potential visual annoyance. This article investigates the state of the art on the PCRC based on fluorescent technologies. Seven articles presenting different combinations of PDRC technologies with fluorescent components to create PCRCs of various colors are presented and analyzed in detail. Quantum dots and phosphors embedded in polymer matrices and combined with reflecting and emitting layers were used as the fluorescent layer of the seven developed green, red, yellow, and yellow–green films. The proposed PCRCs are characterized by very significant differences in cooling performance, although most presented sub-ambient surface temperatures. Their cooling potential is comparatively investigated in terms of the testing climatic conditions and their optical characteristics. The potential increase of their surface temperature, caused by the addition of the fluorescent component, is analyzed through comparisons between the proposed PCRCs and the corresponding white PDRCs without the fluorescent component. The average temperature difference of the green, red, yellow, and yellow–green films against the reference PDRCs is found to be 0.66 °C, 2.6 °C, 1.7 °C and 1.4 °C, respectively. A relevant decreasing trend, but not statistically significant, is observed between the temperature increase caused by the fluorescent additives and the corresponding photoluminescence quantum yield. [ABSTRACT FROM AUTHOR]

Early in history, societies utilize renewable energy sources in response to technical developments and external factors, which resulted in the development of hydropower, wind turbines, and solar PV, as well as their support through policies and agreements. The double ring covered disk resonator solar absorber (DRCDRSA) structures are examined over the spectral range of wavelength 0.2 µm to 2.5 µm (UV-FIR) with the help of finite element method (FEM) in this study. This design achieved effective solar absorption, surpassing 99% over the 0.46 µm band, 95% over 2.05 µm wideband, and 90% over the entire observed spectral range, with an overall average absorbance of 96.38%. In addition, the maximum absorbance is 99.9% with three pick values at the wavelengths of 0.34 µm, 1.35 µm, and 1.51 µm. This research includes a parameter optimization as well as the electric field strength and magnetic field intensity distribution over a three-dimensional solar absorber construction. The structure's angle-polarization study shows it is polarization independent, handles diverse angles, and maintains even absorption up to 60° across all wavelengths. This study explores effective solar heaters for air and water systems, offering promising prospects for maximizing solar energy utilization. [ABSTRACT FROM AUTHOR]

The inheritance of historic human-induced disruption and the fierceness of its impact change aquatic ecosystems. This work reviews some of the main stressors on freshwater ecosystems, focusing on their effects, threats, risks, protection, conservation, and management elements. An overview is provided on the water protection linked to freshwater stressors: solar ultraviolet radiation, thermal pollution, nanoparticles, radioactive pollution, salinization, nutrients, sedimentation, drought, extreme floods, fragmentation, pesticides, war and terrorism, algal blooms, invasive aquatic plants, riparian vegetation, and invasive aquatic fish. Altogether, these stressors build an exceptionally composite background of stressors that are continuously changing freshwater ecosystems and diminishing or even destroying their capability to create and maintain ongoing natural healthy products and essential services to humans. Environmental and human civilization sustainability cannot exist without the proper management of freshwater ecosystems all over the planet; this specific management is impossible if the widespread studied stressors are not deeply understood structurally and functionally. Without considering each of these stressors and their synergisms, the Earth's freshwater is doomed in terms of both quantitative and qualitative aspects. [ABSTRACT FROM AUTHOR]

One of the most crucial considerations for practical applications of organic photovoltaics (OPV) is the stability under sunlight irradiation. It is necessary to translate the small device stability to the module level. Herein, the photostability of the OPV module with three cells connected in series with a total effective area of 10.8 cm2 is presented. The stability of the OPV module is studied under continuous irradiation by a UV light‐emitting diode (LED) with integrated UV intensity the same as AM1.5 solar irradiations. As a result, the OPV module achieves good stability under UV light with a half‐lifetime of about 1300 h without a UV filter. The lifetime is similar to the small device with the same materials. The series resistance and the encapsulation must be optimized simultaneously. The suitable metal of the external electrode greatly improves the OPV module's performance. In addition, the UV stability of the normal structure is shown to be better than the inverted structure because of the photoinstability of the ZnO layer. Moreover, the UV stability of semitransparent OPV modules is shown to be‐ similar to the opaque ones. [ABSTRACT FROM AUTHOR]

Solar ultraviolet radiations induced DNA damages in human skin cells with cyclobutane pyrimidine dimers (CPD) and (6–4) photoproducts (6–4PPs) as the most frequent lesions. CPDs are repaired much slower than 6–4PPs by the nucleotide excision repair pathway, which are thus the major lesions that interfere with key cellular processes and give rise to gene mutations, possibly resulting in skin cancer. In prokaryotes and multicellular eukaryotes other than placental mammals, CPDs can be rapidly repaired by CPD photolyases in one simple enzymatic reaction using the energy of blue light. In this study, we aim to construct recombinant CPD photolyases that can autonomously enter human cell nuclei to fix UV-induced CPDs. A fly cell penetration peptide and a viral nucleus localization signal peptide were recombined with a fungal CPD photolyase to construct a recombinant protein. This engineered CPD photolyase autonomously crosses cytoplasm and nuclear membrane of human cell nuclei, which then efficiently photo-repairs UV-induced CPD lesions in the genomic DNA. This further protects the cells by increasing SOD activity, and decreasing cellular ROSs, malondialdehyde and apoptosis. [ABSTRACT FROM AUTHOR]

Sunscreens are essential in protecting the skin from harmful effects of ultraviolet radiation (UVR). These formulations, designed to absorb, block, or scatter UVR, offer vital protection against skin aging, sunburns, and the development of skin cancers like melanomas. However, some sunscreens, especially those containing organic/chemical compounds, can cause allergic reactions. To address this, researchers are extensively investigating formulations that incorporate plant extracts rich in polyphenols, such as flavonoids and carotenoids, which can be considered safer alternatives. Products derived from plants are commonly used in cosmetics to counteract skin aging due to their antioxidant activity that combat harmful free radicals. This review focuses on evaluating the advancements in chemical and natural sunscreens, exploring the integration of polyphenolic nanocarriers within sunscreen formulas, their interaction with UVR, and utilizing nanotechnology to enhance their effectiveness. An attempt has been made to highlight the concerns related to toxicity associated with their use and notable advancements in the regulatory aspects governing their utilization. [ABSTRACT FROM AUTHOR]

The article discusses the prevalence of melanoma in Australia, highlighting the need for evidence-based approaches to skin cancer detection. It emphasizes the importance of organized screening programs to improve early detection and reduce mortality rates. The text also addresses the challenges of accurate melanoma screening, the use of diagnostic technologies, and the necessity of tailored screening intervals based on individual risk factors. Additionally, it calls for increased investment in education, workforce upskilling, and equitable access to quality skin checks to enhance skin cancer prevention and detection. [Extracted from the article]

As the demand for highly efficient UV‐protective sunscreens continues to rise, the exploration of advanced materials becomes imperative. This paper introduces a novel approach to synthesizing zinc oxide (ZnO) nanomaterials through one‐step solvothermal (ZnO−A) and sonochemical (ZnO−B) methods, eliminating the need for stabilizers or capping agents. The materials have undergone rigorous characterization, focusing on structural and optical properties, and are subsequently evaluated for their UV shielding efficacy. The synthesized ZnO nanomaterials are seamlessly incorporated into a pure cream matrix at varying concentrations (5, 10 and 15 wt. %), offering a versatile application for skin protection against UVA/UVB irradiation. Remarkably, the cream with 15 wt. % ZnO−A emerges as a standout performer, demonstrating immense UV blocking efficacy with 96.44 % for UVA and 97.22 % for UVB. The in vitro sun protection factor (SPF) value of 30.76 further underscores its exceptional performance. This research not only establishes a comprehensive comparative analysis of ZnO−A and ZnO−B nanomaterials but also emphasizes their potential as active ingredients in next‐generation skin care sunscreen formulations. The findings contribute to the ongoing efforts in advancing UV protection technologies, addressing both efficacy and safety considerations. [ABSTRACT FROM AUTHOR]

Pollen, the male gametophyte of seed plants, is extremely sensitive to UV light, which may prevent fertilization. As a result, strategies to improve plant resistance to solar ultraviolet (UV) radiation are required. The tardigrade damage suppressor protein (Dsup) is a putative DNA-binding protein that enables tardigrades to tolerate harsh environmental conditions, including UV radiation, and was therefore considered as a candidate for reducing the effects of UV exposure on pollen. Tobacco pollen was genetically engineered to express Dsup and then exposed to UV-B radiation to determine the effectiveness of the protein in increasing pollen resistance. To establish the preventive role of Dsup against UV-B stress, we carried out extensive investigations into pollen viability, germination rate, pollen tube length, male germ unit position, callose plug development, marker protein content, and antioxidant capacity. The results indicated that UV-B stress has a significant negative impact on both pollen grain and pollen tube growth. However, Dsup expression increased the antioxidant levels and reversed some of the UV-B-induced changes to pollen, restoring the proper distance between the tip and the last callose plug formed, as well as pollen tube length, tubulin, and HSP70 levels. Therefore, the expression of heterologous Dsup in pollen may provide the plant male gametophyte with enhanced responses to UV-B stress and protection against harmful environmental radiation. [ABSTRACT FROM AUTHOR]

Solar ultraviolet (sUV) exposure is known to cause skin damage. However, the pathological mechanisms of sUV on hair follicles have not been extensively explored. Here, we established a model of sUV-exposed skin and its appendages using human induced pluripotent stem cell-derived skin organoids with planar morphology containing hair follicles. Our model closely recapitulated several symptoms of photodamage, including skin barrier disruption, extracellular matrix degradation, and inflammatory response. Specifically, sUV induced structural damage and catagenic transition in hair follicles. As a potential therapeutic agent for hair follicles, we applied exosomes isolated from human umbilical cord blood-derived mesenchymal stem cells to sUV-exposed organoids. As a result, exosomes effectively alleviated inflammatory responses by inhibiting NF-κB activation, thereby suppressing structural damage and promoting hair follicle regeneration. Ultimately, our model provided a valuable platform to mimic skin diseases, particularly those involving hair follicles, and to evaluate the efficacy and underlying mechanisms of potential therapeutics. [ABSTRACT FROM AUTHOR]

Sunlight, and more specifically the UV component, induces several skin damages, including sunburns, erythema and photoaging. The purpose of this work is to set up an ex vivo human skin model to assess the capacity of active principles in protecting skin from the deleterious effects of solar radiation. Ex vivo human skin biopsies were cultured in an air–liquid interface and exposed to solar‐simulated radiation (SSR, 300–750 nm). L‐Carnosine (0.2% and 2%) was applied topically to be tested as photoprotective compound. The effect on oxidative stress induction, photoaging and skin transcriptional profile was assessed by evaluating reactive oxygen species, advanced glycosylation end products formation and gene expression changes. In our model, SSR increases ROS production and AGE accumulation and affects the expression of genes related to oxidative stress, pigmentation, immunity, inflammation and photoaging. Among these pathways, 11 genes were selected as biomarkers to evaluate the skin solar radiation response. Results showed that L‐Carnosine provides effective prevention against solar radiation damages reducing ROS, AGEs and mitigating the modulation of the selected biomarker genes. In conclusion, we report that our ex vivo skin model is a valuable system to assess the consequences of solar light exposure and the capacity of topically applied L‐Carnosine to counteract them. [ABSTRACT FROM AUTHOR]

Beach holidays in areas of strong sunlight are popular and sunscreen is often the primary means of photoprotection favored by many people. The object of this study was to estimate how effective sunscreen is in preventing sunburn under high ultraviolet (UV) levels. We used a computational model to determine how the quantity, frequency, substantivity, and labeled SPF of applied sunscreens impact on the predicted erythemal response in unacclimatized skin over the course of a 7‐day holiday in a high‐solar environment. Our results indicated that sunscreen on its own may be insufficient to prevent sunburn in white skin on a sun‐seeking holiday that combines prolonged exposure with high UV levels. Nevertheless, sunscreens have a valuable role to play on a beach holiday especially if an SPF30 or higher is chosen, the product is applied liberally and uniformly, application is started early into the sun exposure period and repeated at 2‐hourly intervals throughout the day, and the product binds well to the skin. The main limitation of our investigation is that it is not an observational study but rather a computational model and while all models are wrong, some, including this one, are useful. [ABSTRACT FROM AUTHOR]

Background: Organ transplant recipients (OTR) are more likely to develop skin cancer than the general population. One of the main components of the exposome that triggers the development of skin tumours is solar ultraviolet (UV) radiation. To reduce the incidence of harmful consequences of sun exposure, sun protection education is needed for patients taking long‐term immunosuppressive drugs. Methods: In a previous study, we assessed the sun‐safe behaviour of 221 OTR using a questionnaire before and after transplantation and personally educated the patients about proper sun protection. After the education, there were no further reminder presentations. Presently, the sun protection and sun seeking habits of the available 176 of these patients were questioned to assess the long‐term effect of the previous sun protection education. Results: Two‐four years after the education, more patients wore hats and protected their skin with long‐sleeved clothing than before the education. In terms of sun seeking habits, both occupational and recreational sun exposure decreased significantly. Significantly fewer people went on holiday after transplantation, but those who went on holiday spent significantly less time in the sun. Conclusion: The long‐term positive effects of education can be seen both in the patients' sun protection and in their sun seeking habits. However, the long‐term goal is to maintain these results and thereby reduce the likelihood of skin tumours and consequently the associated tumour death. [ABSTRACT FROM AUTHOR]

Background/Purpose: Nowadays, there are emerging trends in customized and personalized photoprotection, focusing on the innovative approaches to enhance sun protection efficacy tailored to individual needs. Methods: We conducted an electronic search of the following databases: MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Skin Group Specialised Skin Register, and TESEO. Specific search terms related to personalized photoprotection and the variables of age, genetic predisposition, skin phototype, photodermatosis, and physiological conditions such as pregnancy, as well as lifestyle habits were used. Results/Conclusion: The article highlights the challenges and opportunities in adopting personalized photoprotection strategies, aiming to promote skin health and prevent the harmful effects of UV radiation in the era of precision medicine. [ABSTRACT FROM AUTHOR]

Although the benefits of sugarcane polyphenol (SP) are well documented, its function in preventing photoaging has not yet been investigated. This study aimed to investigate the protective effects of SP in preventing ultraviolet (UV)‐B‐induced skin photoaging in Balb/c mice, as well as the underlying mechanism. Chlorogenic acid was determined to be the primary component of SP by using high‐performance liquid chromatography‐mass spectrometry. SP and chlorogenic acid were orally administrated to mice for 56 days, and UV‐B radiation exposure was administered 14 days after SP and chlorogenic acid administration and lasted 42 days to cause photoaging. SP and chlorogenic acid administrations significantly alleviated the UV‐B‐induced mouse skin photoaging, as indicated by the decrease in epidermal thickness, increase in the collagen (COL) volume fraction, and elevation in type 1 and type 3 COL contents. Notably, both SP and chlorogenic acid effectively reversed the overexpression of matrix metalloproteinase induced by UV‐B exposure in the mouse skin. Furthermore, SP and chlorogenic acid reduced the expression of receptor for advanced glycosylation end products in the mice; amplified the activities of antioxidant enzymes superoxide dismutase and catalase; reduced malondialdehyde levels; and decreased inflammatory cytokines interleukin 1β, interleukin 6, and tumor necrosis factor α levels. SP could be a prospective dietary supplement for anti‐photoaging applications due to its antioxidant, anti‐inflammatory, and anti‐glycosylation attributes, and chlorogenic acid might play a major role in these effects. Practical Application: This study can provide a scientific basis for the practical application of sugarcane polyphenols. We expect that sugarcane polyphenols can be used in food and beverage products to provide flavor while combating skin aging. [ABSTRACT FROM AUTHOR]

High-resolution thermospheric mass density low Earth orbit (LEO)-based measurements are valuable for accurately estimating short-term atmospheric abrupt disturbances triggered by solar flux forcing. To investigate the enhancing status of solar cycle 25 between August 29 and December 31, 2020, we processed Gravity Recovery and Climate Experiment Follow-on (GRACE-FO) 10-s accelerometer-derived thermospheric mass density (TMD) measurements normalized at 500 km altitude by the NRLMSIS-2.0 empirical model. These 4-month enhancing disturbance observations suggest a shift from relative quiescence to a much more active solar phase, revealing unexpected dependencies on temporal and spatial characteristics. The results indicated that the dominant driver is solar extreme ultraviolet radiation (EUV) during this ascending phase. Density enhancement was symmetric in both hemispheres around the autumn equinox. After the equinox, the neutral density enhancement intensity in the Southern Hemisphere surpasses that in the Northern Hemisphere. Density maxima occurred from high to low latitudes, accompanied by a 2–3 h time lag. The Wygant function was applied to model the response to solar wind geomagnetic field changes and quantify the impact of geomagnetic activities on upper atmosphere density, verifying the time lag of density disturbances. All these findings could potentially improve our understanding of the solar cycle and LEO orbital drag. [ABSTRACT FROM AUTHOR]

Photoaging is the premature aging of the skin caused by prolonged exposure to solar radiation. The visual alterations manifest as wrinkles, reduced skin elasticity, uneven skin tone, as well as other signs that surpass the expected outcomes of natural aging. Beyond these surface changes, there is a complex interplay of molecular alterations, encompassing shifts in cellular function, DNA damage, and protein composition disruptions. This data descriptor introduces a unique dataset derived from ten individuals, each with a minimum of 18 years of professional experience as a driver, who are asymmetrically and chronically exposed to solar radiation due to their driving orientation. Skin samples were independently collected from each side of the face using a microdermabrasion-like procedure and analyzed on an Exploris 240 mass spectrometer. Our adapted proteomic statistical framework leverages the sample pairing to provide robust insights. This dataset delves into the molecular differences in exposed skin and serves as a foundational resource for interdisciplinary research in photodermatology, targeted skincare treatments, and computational modelling of skin health. [ABSTRACT FROM AUTHOR]

Copyright of Farmacia is the property of Societatea de Stiinte Farmaceutice Romania and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)