UVB Light Research Articles

#2153 Difelikefalin: a new solution against itching in CKD-aP patients

Abstract Background and Aims Chronic kidney disease-associated pruritus (CKD-aP) is one of the most common and burdensome symptom affecting patients with advanced chronic kidney disease, with an estimated prevalence of 53.3%. The clinical presentation is extremely variable, from minor lesions to true scratch injuries, and significantly affects the patient's quality of life (QoL), sleep quality and mood, as well as being associated with increased mortality. At present, high-quality evidence on which to base treatment is limited. Currently proposed first-line therapeutic options include optimization of dialysis treatment, emollient agents, UVB light, antihistamines, gabapentin and pregabalin. Recently difelikefalin, a k-opioid receptor agonist, has been the first Food and Drug Administration (FDA) approved drug for moderate-severe CKD-aP treatment. The aim of our study is to demonstrate the efficacy of this drug in relieving symptoms in CKD-aP patients. Method For this preliminary retrospective observational study, 19 patients (9 females, 10 males) with CKD-aP performing dialysis at our Dialysis Center were recruited. All of them had appropriate Kt/V values and had previously been treated with first-line medications. The other main demographic and clinical characteristics of our population, such as calcium-phosphate metabolism and inflammation's indexes, can be seen in Table 1. Our population underwent the Worst Itch Numeric Rating Scale (WI-NRS) by which the presence, intensity, and impact on sleep of this symptom were investigated. They also were subjected to questions that investigate their quality of life (SF-PCS12, SF-MCS12). All patients completed those questionnaires before starting Difelikefalin treatment (t0) and after one month of treatment (t1), 15 of them were evaluated also after three months (t3) and 10 patients, those who first started therapy, reached the assessment at six months (t6). Results Statistical analysis of our preliminary study shows very encouraging data regarding the efficacy of difelikefalin on CKD-aP and sleep quality. As shown in Table 2, we recorded a significant decrease (p value <.001, ƞ2 0.552) in the intensity of itching, most noticeable in the first month, confirming that the effect of this drug is evident and considerable already after four weeks. Our data also demonstrate a significant and lasting positive effect of difelikefalin on sleep quality (p value 0.006, ƞ2 0.592), as shown in Table 3. We found no significant data on the improvement in the QoL of the patients in the study, probably due to the difficulty in standardising this complex feature and due to the limited size of the statistical sample. Furthermore, it should be considered that 3 of the patients enrolled in the study had to discontinue the medication due to the onset of side effects such as diarrhea and headache. Conclusion The most influential limitation of this retrospective observational study is the small number of recruited patients, in addition to the fact that not all of them reached a 6-months treatment evaluation. Our aim is to complete the study by enrolling a larger number of patients from our Dialysis Centre and to monitor the effect of difelikefalin during a longer treatment period, in order to achieve a more accurate analysis and significative results applicable on a larger scale. As far as we can currently evaluate, this drug is significantly effective in reducing CKD-aP and thus in improving the quality of sleep.

Response surface methodology of subcritical water-reactive extraction of gingerol to shogaol ginger dregs through ultraviolet light pretreatment

The increase of shogaol production through reactive extraction of subcritical water depends on the stages of the pretreatment process in destroying the cellular cells of ginger pulp. Pretreatment using ultraviolet B (UVB) is predicted to be able to damage cellular cell walls and outer cell membranes (plasmalemma). In addition, to initiate the degradation of gingerols to shogaols, the reaction conversion and selectivity of shogaols are increased. This study aimed to examine the optimum process conditions for the subcritical water-reactive extraction of gingerol to shogaol from the ginger pulp by utilizing UVB pretreatment: reactive extraction temperature (110 – 130oC), ratio solvent/feed (22:1 – 32:1 b/b), and time (10 – 30 minutes). The extract of shogaol in solvent was separated from the raffinate with a separator funnel and analysed using HPLC-MS. Interpretation of experimental data to optimize the reactive extraction process used the Response Surface Methodology (RSM). The study results show that at 120°C, solvent:inlet ratio 27:1 for 20 minutes through ultraviolet B-light pretreatment for 10 minutes, the yield of shogaol increased from 177 µg/L (without UV) to 18646 µg/L. Moreover, the RSM model was very good at predicting shogaol acquisition responses with a determination coefficient of R2 to be 0.8554. The optimum condition for reactive extraction through UV-B light pretreatment was reached at a temperature of 121.46°C and an inlet solvent ratio of 27.96 at 18.36 minutes, with a shogaol concentration of 18567.1 µg /L.

Two-dimensional Keitz method for the radiant power measurement of planar ultraviolet excilamps

Planar XeBr∗ and XeCl∗ excilamps emitting noncoherent narrowband UVB light (280–315 nm) are now widely used to cure psoriasis and vitiligo as well as to improve vitamin D synthesis. The two-dimensional integral formula has been deducted in this study, which is a good method and has great practical significance to calculate the total radiant power and assess the energy efficiency of a planar UV lamp. The measured radiant power of planar white LED lamps through a two-dimensional Keitz formula has been compared to that of gonio-photometer, verifying the applicability of the formula. The optimum measurement distance is dependent on the lamp length (1.5L≤D≤3.5L) for which the derivation from the two methods can be controlled within 10%. The planar XeBr∗ excilamps have been measured and compared to coaxial excilamps, which show similar patterns of change for the radiant characteristics. Since the planar radiant power formula only needs to measure normal illuminance at a certain distance from the symmetric center of the lamp, it is more convenient to use and is a low-cost method to promote the development of large-sized planar ultraviolet lamps.

Differential fluorescence features and recovery speeds of different scorpion exoskeleton parts during the molting process

Scorpion fluorescence under ultraviolet light is a well-known phenomenon, but its features under excitation in the UVA, UVB and UVC bands have not been characterized. Systematic fluorescence characterization revealed indistinguishable fluorescence spectra with a peak wavelength of 475 nm for whole exuviae from second-, third- and fifth-instar scorpions under different ultraviolet light ranges. In-depth investigations of the chelae, mesosoma, metasoma and telson of adult scorpions further indicated heterogeneity in the typical fluorescence spectrum within the visible light range and in the newly reported fluorescence spectrum with a peak wavelength of 320 nm within the ultraviolet light range, which both showed excitation wavelength-independent features. Dynamic fluorescence changes during the molting process of third-instar scorpions revealed the fluorescence heterogeneity-dependent recovery speed of scorpion exoskeletons. The typical fluorescence spectra of the molted chelae and telson rapidly recovered approximately 6 h after ecdysis under UVA light and approximately 36 h after ecdysis under UVB and UVC light. However, it took approximately 12 h and 24 h to obtain the typical fluorescence spectra of the molted metasoma and mesosoma, respectively, under UVA irradiation and 72 h to obtain the typical fluorescence spectra under UVB and UVC irradiation. The fluorescence heterogeneity-dependent fluorescence recovery of the scorpion exoskeleton was further confirmed by tissue section analysis of different segments from molting third-instar scorpions. These findings reveal novel scorpion fluorescence features and provide potential clues on the biological function of scorpion fluorescence.

Interferon alpha promotes caspase-8 dependent ultraviolet light-mediated keratinocyte apoptosis via interferon regulatory factor 1.

Ultraviolet (UV) light is a known trigger of both cutaneous and systemic disease manifestations in lupus patients. Lupus skin has elevated expression of type I interferons (IFNs) that promote increased keratinocyte (KC) death after UV exposure. The mechanisms by which KC cell death is increased by type I IFNs are unknown. Here, we examine the specific cell death pathways that are activated in KCs by type I IFN priming and UVB exposure using a variety of pharmacological and genetic approaches. Mice that overexpress Ifnk in the epidermis were exposed to UVB light and cell death was measured. RNA-sequencing from IFN-treated KCs was analyzed to identify candidate genes for further analysis that could drive enhanced cell death responses after UVB exposure. We identify enhanced activation of caspase-8 dependent apoptosis, but not other cell death pathways, in type I IFN and UVB-exposed KCs. In vivo, overexpression of epidermal Ifnk resulted in increased apoptosis in murine skin after UVB treatment. This increase in KC apoptosis was not dependent on known death ligands but rather dependent on type I IFN-upregulation of interferon regulatory factor 1 (IRF1). These data suggest that enhanced sensitivity to UV light exhibited by lupus patients results from type I IFN priming of KCs that drives IRF1 expression resulting in caspase-8 activation and increased apoptosis after minimal exposures to UVB.

Stimuli-Responsive Control over Self-Assembled Nanostructures in Sequence-Specific Functional Block Copolymers.

The precise sequence of a protein's primary structure is essential in determining its folding pathways. To emulate the complexity of these biomolecules, functional block copolymers consisting of segmented triblocks with distinct functionalities positioned in a sequence-specific manner are designed to control the polymer chain compaction. Triblock polymers P- b -C- b -F and P- b -F- b -C and random diblock copolymer P- b -C- r -F consist of a hydrophilic poly(ethylene oxide) (PEO) block and a hydrophobic block with coumarin (C) and ferrocene (F) moieties that are grafted in a sequence-specific or random manner onto the hydrophilic block. External stimuli such as UVB light, redox, and chemical cues influence the functional hydrophobic block to alter the packing parameters that are monitored with spectroscopic and scattering techniques. Interestingly, the positioning of the stimuli-responsive moiety within the hydrophobic block of P- b -C- b -F, P- b -F- b -C, and P- b -C- r -F affects the extent of the hydrophobic-hydrophilic balance in block copolymers that renders orthogonal control in stimuli-responsive transformation of self-assembled vesicles to micelles.

Proline accumulation and antioxidant response are crucial for citrus tolerance to UV-B light-induced stress.

Plants face a wide range of biotic and abiotic stress conditions, which are further intensified by climate change. Among these stressors, increased irradiation in terms of intensity and wavelength range can lead to detrimental effects, such as chlorophyll degradation, destruction of the PSII reaction center, generation of ROS, alterations to plant metabolism, and even plant death. Here, we investigated the responses of two citrus genotypes, Citrus macrophylla (CM), and Troyer citrange (TC) to UV-B light-induced stress, by growing plants of both genotypes under control and UV-B stress conditions for 5 days to evaluate their tolerance mechanisms. TC seedlings had higher sensitivity to UV-B light than CM seedlings, as they showed more damage and increased levels of oxidative harm (indicated by the accumulation of MDA). In contrast, CM seedlings exhibited specific adaptive mechanisms, including accumulation of higher levels of proline under stressful conditions, and enhanced antioxidant capacity, as evidenced by increased ascorbate peroxidase activity and upregulation of the CsAPX2 gene. Phytohormone accumulation patterns were similar in both genotypes, with a decrease in ABA content in response to UV-B light. Furthermore, expression of genes involved in light perception and response was specifically affected in the tolerant CM seedlings, which exhibited higher expression of CsHYH/CsHY5 and CsRUP1-2 genes. These findings underscore the importance of the antioxidant system in citrus plants subjected to UV-B light-induced stress and suggest that CsHYH/CsHY5 and CsRUP1-2 could be considered genes associated with tolerance to such challenging conditions.

Does the Symbiotic Relationship Between Hydra Viridissima and Photoautotrophic Alga Provide an Evolutionary Advantage in Protecting DNA against Damage by the Cytotoxic or Genotoxic Mode of Action of Environmental Stressors?

The aim of this paper was to evaluate whether symbiotic cooperation between green hydra (Hydra viridissima) and photoautotrophic alga gives higher resistance of the preservation of DNA integrity compared to brown hydra (Hydra oligactis). Norflurazon concentrations were 0.061 or 0.61mg/L and UV-B light 254nm, 0.023mWcm- 2 applied separately or simultaneously. By alkaline comet assay primary DNA damage was assessed and cytotoxicity by fluorescent staining. Norflurazon at 0.61 mg L- 1 significantly increased DNA damage in brown hydras compared to the control (6.17 ± 0.6μm, 5.2 ± 1.7% vs. 2.9 ± 0.2μm, 1.2 ± 0.2%). Cytotoxicity was significantly elevated, being higher in brown hydras (25.7 ± 3.5% vs. 8.2 ± 0.2%). UV-B irradiation induced significant DNA damage in brown hydras (13.5 ± 1.0μm, 4.1 ± 1.0%). Simultaneous exposure to UV-B and norflurazon led to a synergistic DNA damaging. The frequency of cytotoxicity and hedgehog nucleoids was more pronounced in brown (78.3 ± 9.4%; 56.4 ± 6.0%) than in green hydras (34.7 ± 2.5%; 24.2 ± 0.6%). Evolutionary established symbiotic cooperation proved to provide resistance against cyto/genotoxicity.

An Overview of Contemporary and Future Therapeutic Strategies for Scalp Psoriasis.

Scalp psoriasis is a common manifestation of psoriasis that significantly impacts a patient's quality of life. About 80% of cases of psoriasis involve the scalp, making it the most frequently affected area of the body. The treatment of scalp psoriasis is particularly crucial because of its hard-to-treat nature and substantial adverse impacts on overall well-being. Along with the physical symptoms of discomfort and itching, psoriasis, especially when it affects the scalp, can cause severe psychological damage. Treating scalp psoriasis can be challenging due to its location and associated symptoms, such as scaling and pruritus, which is why various drugs have become widely used for refractory cases. Topical treatments like corticosteroids and vitamin D analogs manage scalp psoriasis by reducing inflammation and regulating skin cell growth. Tar-based shampoos, salicylic acid solutions, and moisturizers control scaling. Phototherapy with UVB light reduces inflammation. Severe cases may require systemic medications such as oral retinoids and immunosuppressants. While various therapies are accessible for scalp psoriasis, concerns arise due to their limited advantages and the absence of controlled studies assessing their effectiveness. Considering these challenges, there is a clear demand for innovative approaches to address this condition effectively. Recent advancements in topical therapies, phototherapy, systemic agents, and complementary therapies have shown promising results in managing scalp psoriasis. Also, the advent of biologics, specifically anti-IL-17 and anti-IL-23 drugs for scalp psoriasis, has seen significant improvements. The review highlights the lack of well-tolerated and effective treatments for scalp psoriasis and underscores the importance of further research in this area. The objective of this review is to clarify the different treatment options currently available or being investigated in clinical trials for managing scalp psoriasis.

Recent advances in UV-B signalling: interaction of proteins with the UVR8 photoreceptor.

The photoreceptor UVR8 mediates many plant responses to UV-B and short wavelength UV-A light. UVR8 functions through interactions with other proteins which lead to extensive changes in gene expression. Interactions with particular proteins determine the nature of the response to UV-B. It is therefore important to understand the molecular basis of these interactions: how are different proteins able to bind to UVR8 and how is differential binding regulated? This concise review highlights recent developments in addressing these questions. Key advances are discussed with regard to: identification of proteins that interact with UVR8; the mechanism of UVR8 accumulation in the nucleus; the photoactivation of UVR8 monomer; the structural basis of interaction between UVR8 and CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1) and REPRESSOR OF UV-B PHOTOMORPHOGENESIS (RUP) proteins; the role of UVR8 phosphorylation in modulating interactions and responses to UV-B. Nevertheless, much remains to be understood and the need to extend future research to the growing list of interactors is emphasised.

Effects of ambient UVB light on Pacific oyster Crassostrea gigas mantle tissue based on multivariate data

Ambient ultraviolet radiation (UVB) from solar and artificial light presents serious environmental risks to aquatic ecosystems. The Pacific oyster, Crassostrea gigas, perceives changes in the external environment primarily through its mantle tissue, which contains many nerve fibers and tentacles. Changes within the mantles can typically illustrate the injury of ambient UVB. In this study, a comprehensive analysis of phenotypic, behavioral, and physiological changes demonstrated that extreme UVB radiation (10 W/m²) directly suppressed the behavioral activities of C. gigas. Conversely, under ambient UVB radiation (5 W/m²), various physiological processes exhibited significant alterations in C. gigas, despite the behavior remaining relatively unaffected. Using mathematical model analysis, the integrated analysis of the full-length transcriptome, proteome, and metabolome showed that ambient UVB significantly affected the metabolic processes (saccharide, lipid, and protein metabolism) and cellular biology processes (autophagy, apoptosis, oxidative stress) of the C. gigas mantle. Subsequently, using Procrustes analysis and Pearson correlation analysis, the association between multi-omics data and physiological changes, as well as their biomarkers, revealed the effect of UVB on three crucial biological processes: activation of autophagy signaling (key factors: Ca2+, LC3B, BECN1, caspase-7), response to oxidative stress (reactive oxygen species, heat shock 70, cytochrome c oxidase), and recalibration of energy metabolism (saccharide, succinic acid, translation initiation factor IF-2). These findings offer a fresh perspective on the integration of multi-data from non-model animals in ambient UVB risk assessment.

The Effect of Sapodilla Leaf Extract (Manilkara Zapota L.P Royen) on IL-1 and TNF- α Expression in Male White Rats Wistar Strain Induced with UVB Light

Excessive UVB exposure causes health problems in humans, the effect on the skin is molecular and cellular changes. Sunburn is the most obvious acute clinical effect, resulting in the production of TNF-α by keratinocytes, IL-1 is a cytokine that influences TNF-α. Skin wounds release various damage associated molecular patterns (DAMPs) which will activate inflammatory signaling pathways such as NLRP3 inflammasomes and toll-like receptors (TLRs) which cause increased production of inflammatory cytokines. The aim of this study was to examine the anti-inflammatory effect of Manilkara zapota leaf extract which was assessed based on the expression of IL-1 and TNF-α in Wistar rats exposed to UVB. Post-test only control group design experimental research using rats (Rattus norvegicus) as research objects, divided into 4 groups, namely (K1) control rats without treatment, (K2) rats exposed to UVB light then given placebo cream, (K3) rat group exposed to UVB light then given 25% sapodilla leaf extract cream, and (K4) mice were exposed to UVB light then given 50% sapodilla leaf extract cream. The average expression of IL-1 using the One-Way ANOVA test was 0.197 (p0.05), which means there was no significant difference in the average expression of IL-1 between groups. Meanwhile, the average TNF-α expression between groups was 0.036 (p0.05), the results showed that there was a significant difference in the average TNF-α expression between groups, TNF-α expression using the Post Hoc LSD test of sapodilla leaf extract cream 50% dose (K4) reduced TNF-α expression to a lesser extent than K1 or K2. Administration of leaf extract cream (Manilkara zapota) affected the expression of TNF-α, but did not affect the expression of IL-1 in a mouse model experiencing sunburn.

Effect of Petai Bark Extract Gel on Tyrosinase and TRP1 Gene Expression (In Vivo Experimental Study on Hyperpigmented Wistar Mice Exposed to UVB Model)

UVB irradiation can induce the formation of Reactive Oxygen Species (ROS) which causes activation of melanin synthesis through activation of tyrosinase and tyrosinase related protein-1 (TRP1). Secondary metabolites contained in petai peel extract are known to play a role in inhibiting ROS production due to exposure to UVB rays. This study aims to determine the effect of administering petai peel extract gel on the expression of the tyrosinase and TRp1 genes in mouse skin tissue exposed to UVB. The research design was posttest only control group with a completely randomized design method. The samples studied were 24 mice exposed to UVB light with a wavelength of 302 nm and an energy of 390mJ/cm2/day 3 times a week for 2 weeks. This research was carried out in four groups, namely the healthy group (K1), the negative control group (K2), treatment 1 (K3) with 10% petai peel extract gel and treatment 2 (K4) with 20% petai peel extract gel. Tyrosinase and TRP1 gene expression was analyzed using qRT-PCR. qRT-PCR analysis showed that there was a significant decrease in tyrosinase and TRP1 gene expression between groups K3 (tyrosinase 3,19±2,12 and TRP1 4,96±3,42) and K4 (tyrosinase 0,65±0,44 and TRP1 2,22±1,18) compared to group K2 (tyrosinase 17,92±3,77 and TRP1 35,91±4,52). Administration of petai peel extract gel can reduce the expression of tyrosinase and TRP1 genes in hyperpigmentation mice exposed to UVB light.

Effect of Soybean Extract Cream on Matrix Metalloproteinase-1 (MMP-1) and Interleukin-6 (IL-6) Levels (In Vivo Experimental Study on UVB-Induced Balb/c Mice)

UV radiation causes skin disorders that start from the formation of reactive oxygen species (ROS) and the synthesis of MMP-1 by dermal fibroblasts which plays a role in skin aging, resulting in an increase in IL-6 levels which correlates with tissue damage and inflammation that occurs. The compounds contained in soybean extract are known to act as anti-inflammatory and antioxidants which can reduce inflammation and reduce the negative impact of UV rays on the skin. This study aims to determine the effect of giving soybean extract cream on MMP-1 levels and IL-6 levels in the skin tissue of bablb/c mice induced by UVB light. This research design was a posttest only control group with a completely randomized design method. The samples studied were 36 female balb/c mice with UVB light induction with a wavelength of 302 nm and an energy of 1 MED 5 times a week for 2 weeks. This research was carried out in five groups, namely the healthy group (K1), negative control group (K2), positive control group (K3), with treatment group 1 (K4) with 10% soybean extract cream and treatment group 2 (K5) with extract cream. soybeans 20%. MMP-1 levels and IL-6 levels were analyzed using ELISA. ELISA analysis showed that there was a significant decrease in the mean MMP-1 concentration between K2 (6488 ± 805) compared to K5 (5396 ± 522) with a p value 0.05. Analysis of IL-6 concentration also showed that there was a significant decrease in the mean IL-6 concentration in K4 (270±50) and k5 (242±54) compared to K2 (661±90) with a p value 0.05. Giving soybean extract cream can reduce MMP-1 and IL-6 levels in female Balb/c mice induced by UVB light.

The Addition of Astaxanthin 0.5% in Sunscreen SPF 50 Inhibits the Increase of Sunburn Cells in Rats Induced By Ultraviolet Light B

Long-term exposure to ultraviolet light can cause chronic inflammation that can damage collagen and increase sunburn cells known as photoaging. There is a prevalence of up to 69% in female students in Jakarta aged 18–21 years who experience aging of the skin due to not using sunscreen. One of the signs of photoaging measured in this study is sunburn cells. This study wants to prove that the addition of astaxanthin 0.5% contained in SPF 50 sunscreen can inhibit the increase in sunburn cells in mice induced by ultraviolet B-light. Sunscreen also has protection limits, for example, SPF 30 has 97% protection, which means there is still 3% of radiation entering the skin so there is still a small portion that can cause free radicals. Additional ingredients are needed so that sunscreen can optimally protect the skin. An experimental study with a post-test-only design was used in this study comparing rats given SPF 50 sunscreen containing no astaxanthin (P1) and rats given SPF 50 sunscreen containing 0.5% astaxanthin (P2) to assess the inhibition of increased sunburn cells. 36 rats (Rattus Norvegicus) were divided into 2 groups and then shaved and exposed to UVB light with a total of 3100 mJ for 5 weeks. After the last exposure in the fifth week, skin tissue was taken fixed and stained using Hematoxylin Eosin to count sunburn cells. Sunburn Cells in group P1 had a value of 0.47 Å} 0.27 cells per high power field (hpf), and group P2 had a value of 0.16 Å} 0.18 cells per hpf. According to the Mann-Whitney test, there is a significant difference in the number of sunburn cells between groups (p < 0.05). From the results of this study, it can be concluded that astaxanthin 0.5% added to SPF 50 sunscreen products can inhibit the increase in sunburn cells.

Template assisted hydrothermal synthesis of bismuth vanadate for Rhodamine B photodegradation

Developmental and technological activities result in uncontrollable release of synthetic dyes into water reservoirs posing potential threat to flora and fauna. Thus, the development of suitable process to treat these waste effluents is urgently needed. Herein, a facile technique was employed to synthesize bismuth vanadate (BiVO4) by incorporating Chitosan (Cs) and Triblock pluronic 123 (P) as directing agents through the hydrothermal process and its efficacy as a photocatalyst was tested for Rhodamine B (RhB) photodegradation. It is noteworthy that the use of Cs as template during the synthesis of BiVO4 had not been previously documented. The synthesized materials were subject to a comprehensive array of characterization techniques, including XRD, FTIR, UV–visible diffuse reflection, SEM, TEM, N2 adsorption isotherm, and XPS analyses. The outcomes revealed that the synthesized catalysts have a monoclinic scheelite structure and displayed an irregular morphology. In addition, the particle size decreased remarkably with the use of Cs. The XPS revealed that the templates have a major influence on the surface charge of the material, as revealed by point of zero charge (pHPZC) analysis. Notably, BiVO4-Cs exhibited the highest specific surface area (SSA: 12.27 m2/g) among them. The synthesized photocatalysts exhibited high catalytic stability. Additionally, the photocatalysts showed excellent RhB photodegradation performance of 94.2 and 64.4 % under UV-B and visible light illumination, respectively.

Ultraviolet Light-Assisted Decontamination of Chemical Warfare Agent Simulant 2-Chloroethyl Phenyl Sulfide on Metal-Loaded TiO2/Ti Surfaces.

The application of ultraviolet (UV) light for the decontamination of chemical warfare agents (CWAs) has gained recognition as an effective method, especially for treating hard-to-reach areas where wet chemical methods are impractical. In this study, TiO2/Ti was employed as a model catalyst, which was contaminated with 2-chloroethyl phenyl sulfide (CEPS), and subjected to photocatalytic decontamination using both UVB and UVC light. Additionally, photocatalytic decontamination efficiency by introducing Au, Pt, and Cu onto the TiO2/Ti surface was explored. During the photodecomposition process under UVC light, at least eight distinct secondary byproducts were identified. It was observed that the introduction of overlayer metals did not significantly enhance the photodecomposition under UVC light instead overlaid Au exhibited substantially improved activity under UVB light. Whereas, photodecomposition process under UVB light, only five secondary products were detected, including novel compounds with sulfoxide and sulfone functional groups. This novel study offers valuable insights into the generation of secondary products and sheds light on the roles of overlayer metals and photon wavelength in the photodecontamination process of CWA.

Mechanisms and Comparative Treatments of Allergic Rhinitis including Phototherapy

The treatment of allergic conditions presents a challenge for both seasonal allergic rhinitis and perennial rhinitis sufferers. The increasing prevalence of both of these types of allergic responses requires the use of a range of treatments which can provide relief. The treatment of allergic rhinitis has been considered under the ARIA (Allergic Rhinitis and its Impact on Asthma) guidelines. Current treatment options include medication and avoidance for those with reduced responses, but more expensive treatments include immunotherapy and the use of monoclonal antibodies (mAb). All treatments target specific parts of the inflammatory response which includes mast cells, eosinophils and basophils. Phototherapy can be a useful addition to these treatments, and combinations of UV-B (5%), UV-A (25%) and visible light (70%) in phototherapy treatments have been shown to reduce the severity of symptoms. Phototherapy consisting of visible wavelengths and infrared light (660 nm 940 nm) was shown to be particularly effective in treating perennial rhinitis. The use of a range of wavelengths in the control of allergic responses is described in this paper. Phototherapy can form part of an effective treatment regime for allergic rhinitis sufferers which can exploit synergies in the control of the condition elicited through several pathways.

Transcriptional regulation of flavonol biosynthesis in plants.

Flavonols are a class of flavonoids that play a crucial role in regulating plant growth and promoting stress resistance. They are also important dietary components in horticultural crops due to their benefits for human health. In past decades, research on the transcriptional regulation of flavonol biosynthesis in plants has increased rapidly. This review summarizes recent progress in flavonol-specific transcriptional regulation in plants, encompassing characterization of different categories of transcription factors (TFs) and microRNAs as well as elucidation of different transcriptional mechanisms, including direct and cascade transcriptional regulation. Direct transcriptional regulation involves TFs, such as MYB, AP2/ERF, and WRKY, which can directly target the key flavonol synthase gene or other early genes in flavonoid biosynthesis. In addition, different regulation modules in cascade transcriptional regulation involve microRNAs targeting TFs, regulation between activators, interaction between activators and repressors, and degradation of activators or repressors induced by UV-B light or plant hormones. Such sophisticated regulation of the flavonol biosynthetic pathway in response to UV-B radiation or hormones may allow plants to fine-tune flavonol homeostasis, thereby balancing plant growth and stress responses in a timely manner. Based on orchestrated regulation, molecular design strategies will be applied to breed horticultural crops with excellent health-promoting effects and high resistance.

A2 UVB ON SKIN EXPOSURE MODULATES INTESTINAL HOMEOSTASIS IN MICE

Abstract Background Inflammatory diseases, like IBD, are on the rise in Western societies, in concert with changes in the environment, such as reduced sun exposure. Ultraviolet light (UV) B's effects on the skin include upregulating vitamin D and Aryl hydrocarbon receptor (Ahr) signalling, but its potential influence on distant sites, like the gut, are not well-studied. The gut and skin share a strong link, with some GI patients also experiencing skin diseases (O’Neill et al., 2016). We sought to understand how UVB exposure affects gut health, gut microbiota and its metabolic by-products. We hypothesize that UVB will have a significant impact on gut health. Aims Test the effect of UVB light using vitamin D deficient (-) and sufficient (+) diets. Elucidate Ahr activation in the small intestine and colon after UVB exposure. Explore the gut metabolome after UVB exposure. Methods Female C57BL/6 mice were fed vit D (+) or (-) diets, anaesthetized, and then 8 cm2 of their dorsal skin was shaved and exposed to UVB (250 mJ/cm2, 234 sec, 311 nm). One single dose (sample collection after 4 or 10 h) or chronic dosage (9 days every other day). Mice were euthanized to collect serum, cecal content, and stool samples (HILIC negative profile and 16S sequencing). EROD assay was used to test Ahr activation of CYP1A1. Results UVB exposure did not cause skin inflammation, but instead induced photoadaptation. When mice with vit D (-) diets were exposed to UVB, their vit D levels rose to match those on vit D (+) diets. Intestinal luminal contents induced a significant 3X increase in Ahr activation at 10 h post-exposure. After chronic UVB exposure, Ahr/CYP1A1 activity increased in Peyer’s patches (p=0.0012) and colon (p=0.01). Serum levels of AhR agonist metabolites post-UVB exposure showed significant increases in kynurenine and indole-3-acetic acid (IAA) at 10 h, while in the feces, Tryptophan levels decreased (p=0.042), but IAA significantly increased (p=0.006). IAA is a known Ahr ligand and produced by gut microbiota when they metabolize Tryptophan, indicating a microbiota response to UVB skin exposure. This was accompanied by an increase in the short chain fatty acids (butyrate, propionate, acetic acid) as well as other metabolites, despite no overt changes in microbiota composition. After 9 days of UVB, significantly increased numbers of goblet cells/crypt in both the ileum and colon. Conclusions Our study demonstrates that UVB exposure on the skin leads to increased vitamin D serum levels and Ahr activation along the gastrointestinal tract. It also induces potentially beneficial metabolic changes in the gut microbiota and differentiation of the gut epithelium, highlighting sun exposure's potential intestinal health benefits. Funding Agencies CCC, CIHR, None