Harmful Ultraviolet Radiation Research Articles

Potential Beneficial Effects of Mineral Sunscreens on Acne-Prone Skin

Background: Sunscreens are critical products used against harmful ultraviolet (UV) radiation. However, beyond the effect of sun protection, the inorganic UV filters zinc oxide and titanium dioxide have shown antimicrobial activity. Objective: This study aimed to evaluate the potential additional beneficial effects of mineral sunscreens containing zinc oxide and titanium dioxide as antimicrobial agents on acne-prone skin. Methods: Transepidermal water loss, skin hydration, and skin pH of twelve volunteers were measured before and 2 h after the application of three mineral sunscreens. The antimicrobial activity of the mineral sunscreens was determined against Cutibacterium acnes, Staphylococcus aureus, and Staphylococcus epidermidis in a time-kill test. Results and Discussion: The studied mineral sunscreens did not affect either the stratum corneum hydration or its integrity, but they increased the skin pH from 4 to 6, which could impact the skin microbiota balance. At the same time, the tested mineral sunscreens inhibited Cutibacterium acnes, Staphylococcus epidermidis, and Staphylococcus aureus. Conclusion: This study suggests that the two UV filters can have positive effects on acne-prone skin and, thus, extend the benefits of photoprotective formulations. Nevertheless, further research is currently being conducted.

Development of Highly Ultraviolet-Protective Polypropylene/TiO2 Nonwoven Fiber

In recent decades, there has been a rise in public consciousness of the adverse effects of expanded skin contact with sunlight, particularly the ultraviolet (UV) spectrum. UV radiation causes serious health problems like skin cancer, early aging, erythema, pigmentation, etc., due to contact with the skin. Therefore, the highly efficient UV-protection materials were manufactured using polypropylene and TiO2 (PPTO) through cost-effective and easy methods. The designated 7.5 PPTO and 15 PPTO were prepared, varying the amount of TiO2, as well as without using TiO2 (PPNF), which was also manufactured as a control material. All the as-synthesized nonwoven fibers were carefully characterized employing a variety of microscopic and spectroscopic methods, such as X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy, and contact angle measurements. In conclusion, 15 PPTO showed the highest UV-protection ability (87.5%) compared to 7.5 PPTO and PPNF. In addition, 15 PPTO exhibited 1.76 and 1.32 times higher protection than 7.5 PPTO and PPNF, respectively, when exposed to UB-B radiation. The enhanced activity may be due to the amount of TiO2 because TiO2 increased the product’s absorption and reflection capability. Overall, the PPTO nonwoven fibers can be applied to block harmful UV radiation.

An Updated Review on the Role of Phytoconstituents in Modulating Signalling Pathways to Combat Skin Ageing: Nature’s Own Weapons and Approaches

Abstract: Various geographical areas exhibit varying degrees of prevalence and severity of dermatological issues. The most commonly observed skin issues among adolescents during their growth period on a global scale encompass dry skin, dyspigmentation, wrinkles, fungal infections, as well as benign and malignant tumors. These conditions arise as a consequence of diminished functional capacity and heightened skin susceptibility. The primary manifestation of the whole process of skin ageing is its visual presentation, which encompasses changes in both the structure and function of the skin. The look and function of human skin exhibit particular variations as individuals age, representing a time-dependent phenomenon. This review article primarily examines the discussion surrounding the diverse phytoconstituents and their impact on signalling pathways in cellular metabolism, as well as their interaction with environmental factors and xenobiotic agents that contribute to skin aging. Ultraviolet (UV) light induces the rapid formation and subsequent accumulation of reactive oxygen species (ROS) within skin cells, hence accelerating oxidative stress and the ageing process of the skin. One effective approach to addressing age-related skin disorders entails the utilization of exogenous supplementation through the consumption of dietary antioxidants, as well as the application of antioxidant-based lotions to the skin prior to sun exposure. Several plant species include phenolic components, including ascorbic acid, ellagitannins, and carotenoids, which have the ability to protect the skin from harmful UV radiation, reduce inflammation and oxidative stress, and influence several survival signalling pathways. This comprehensive study elucidated multiple processes by which phytoconstituents exert their effects for intervention purposes. Additionally, it highlighted the ability of these phytoconstituents to modulate the NF-κB signalling pathway, MAPK signalling, Nrf2 signalling, and other pathways, hence demonstrating their potential anti-aging properties.

Preliminary Evaluation of Photoprotective Potential in Flowers of Osbeckia octandra (L.) DC. for Development of Herbal Sunscreen Formulations

Introduction: Excessive exposure to ultraviolet (UV) radiation of the solar spectrum is often linked with the onset of conditions like inflammation, photoaging, immunosuppression, hyperpigmentation, and photocarcinogenesis. Although synthetic sunscreens have emerged as protectants against this harmful UV radiation, there is an increasing demand for sunscreens of herbal origin, which are believed to have low side-effect profiles in comparison to their synthetic counterparts. In order to cater for this need, the present study aimed at developing herbal sunscreen formulations from flowers of Osbeckia octandra DC, a purple-coloured wildflower widely distributed across different geographical regions in Sri Lanka. Methodology: The UV filtering potency and subsequently, the sun protection factor (SPF) in the methanolic extract of O. octandra was initially determined. Thereafter this extract was incorporated into the aqueous cream base at 25%, 50%, and 75% (w/w) and the SPF values and photostability of the prepared formulations were evaluated. Results: The initial SPF value of the crude extract (39.91 ± 1.93) had hardly changed even after incorporating it at 75% into the aqueous cream base. This 75% formulation surpassed the other two formulations and the commercial sunscreen (positive control) in terms of the higher SPF and broader spectrum of UV absorption. Its SPF value altered only slightly during the storage for 21 days in light or dark conditions and was photostable. Conclusion: Our preliminary observations demonstrated the appropriateness of O. octandra for the formulation of herbal sunscreens at the commercial stage. Keywords: Herbal sunscreens, Osbeckia octandra, Photoprotection, Sun protection factor, UV radiation

The Comparison of Titanium Dioxide and Zinc Oxide Used in Sunscreen Based on Their Enhanced Absorption

Nanomaterials have become increasingly popular in the cosmetic industry, especially in sunscreen production. These tiny particles can improve the performance of sunscreen products by enhancing their capacity to reflect and absorb ultraviolet (UV) radiation. This paper introduces two typical metal oxide nanoparticles (NPs), TiO2 NPs and ZnO NPs, in sunscreen and cosmetic products. Because of their propensity to absorb and deflect harmful UV radiation, they are frequently utilised. However, there is rising worry regarding the safe use of nanoparticles in these products especially the potential negative impact on human health. Moreover, the environmental risks associated with them, particularly in terms of their enhanced absorption properties also make their use an ongoing debate. In fact, studies have suggested that while they can result in more effective sun protection, they may also lead to unintended consequences. This paper also compares their sun protection effects, environmental impacts and health risks. It is crucial for customers to weigh the benefits and risks of nanomaterials in cosmetics and for both manufacturers and governments to adopt appropriate and detailed measures to ensure their safe and responsible use.

Isolation and Structure Elucidation of Novel Mycosporine-like Amino Acids from the Two Intertidal Red Macroalgae Bostrychia scorpioides and Catenella caespitosa.

This study presents a phytochemical survey of two common intertidal red algal species, Bostrychia scorpioides and Catenella caespitosa, regarding their MAA (mycosporine-like amino acid) composition, which are known as biogenic sunscreen compounds. Six novel MAAs from Bostrychia scorpioides named bostrychines and two novel MAAs from Catenella caespitosa named catenellines were isolated using a protocol which included silica gel column chromatography, flash chromatography on reversed phase material and semipreparative HPLC (High-Performance Liquid Chromatography). The structure of the novel MAAs was elucidated using NMR (Nuclear Magnetic Resonance) and HR-MS (High-Resolution Mass Spectrometry), and their absolute configuration was confirmed by ECD (Electronic Circular Dichroism). All isolated MAAs possess a cyclohexenimine scaffold, and the metabolites from B. scorpioides are related to the known MAAs bostrychines A-F, which contain glutamine, glutamic acid and/or threonine in their side chains. The new MAAs from C. caespitosa contain taurine, an amino sulfonic acid that is also present in another MAA isolated from this species, namely, catenelline. Previous and new data confirm that intertidal red algae are chemically rich in MAAs, which explains their high tolerance against biologically harmful ultraviolet radiation.

Photoprotective Cosmetic Emulsions Based on Brazilian Smectite Clays

Photoprotective cosmetic emulsions have gained significant attention in the cosmetic industry due to their ability to protect against harmful ultraviolet radiation (UV). In this work, photoprotective cosmetic emulsions were prepared by adding 5% natural (Branca and Verde Inferior) and commercial (Brasgel and Cloisite) Brazilian clays to different photoprotective emulsions with and without UVA and UVB chemical filters (EB, EB1 and EB2). All clays were benefited (crushed, milled and sieved) and characterized (X ray fluorescence and X ray diffraction). Additionally, a thermal treatment (120 °C by 24 h) was accomplished in the natural clays, aimed at decontamination. The emulsions were characterized for their organoleptic properties, centrifugation test, viscous behavior, pH values and in vitro sun protection factor (SPF). The cosmetic emulsions prepared without any addition of UV chemical filters presented the lowest in vitro and UVB absorption values because the clays used (Cloisite and Branca) did not have the potential to absorb UV radiation. Although some of the cosmetic emulsions prepared from EB1 and EB2 photoprotective emulsions presented phase separation, all of them presented in vitro SPF values according to the Brazilian standard (above 6), indicating that they have the potential to be used in the cosmetic industry.

Stratospheric dynamics modulates ozone layer response to molecular oxygen variations

Photolysis of molecular oxygen (O2) sustains the stratospheric ozone layer and is thereby protecting living organisms on Earth by absorbing harmful ultraviolet radiation. In the past, atmospheric O2 levels were not constant, and their variations are thought to be responsible for the extinction of some species due to the thinning of the ozone layer. Over the Phanerozoic Eon (last ∼500 Mio years), the O2 volume mixing ratio ranged between 10% and 35% depending on the level of photosynthetic activity of plants and oceans. Previous estimates, mostly performed by simplified 1-D models, showed different ozone (O3) responses to atmospheric O2 changes within this range, such as monotonically positive or negative correlations, or displaying a maximum in the O3 column around a certain O2 level. Here, we assess the ozone layer sensitivity to atmospheric O2 varying between 5% and 40% with a state-of-the-art 3-D chemistry-climate model (CCM). Our findings show that the O3 layer thickness maximizes around the current mixing ratio of O2, 21% ± 5%, while lower or higher levels of O2 result globally in a reduction of total column O3. At low latitudes, the total column O3 is less sensitive to O2 variations, because of the “self-healing” effect, namely, a vertical dipole in the tropical ozone response. Mid- and high-latitude O3 columns that are largely affected by transport of O3 from the tropics, however, are much more sensitive to O2 with changes up to 20 DU even for small (±5%) O2 perturbations. We show that these variations are largely driven by the radiative impact of O3 on stratospheric temperatures and on the strength of the Brewer-Dobson circulation (BDC), indicating chemistry-radiation-transport feedback. High O2 cases result in an acceleration of the BDC and vice versa, which always works in favor of the negative part of the O3 anomaly dipole in the tropics being more effectively transported to the mid- and high-latitudes than the positive one. Although there are other factors strongly influencing O3/O2 relationship on the Phanerozoic Eon timescales that have not been considered here, our results and the presented mechanism bring useful insights for other studies focusing on the long-term O3/O2 relationship.

Assessing the Knowledge, Attitude, Practice towards the Sun Exposure and the use of Sunscreen by the General Population in Makkah, Saudi Arabia

Context: Sunlight exposure is a major cause of melanoma and non-melanoma skin cancer (NMSC). The sunscreen use can reduce the risk of developing melanoma and NMSC. Purpose: To assess the knowledge, attitude, and practice of the general population of Makkah city, Saudi Arabia related to sun exposure and the use of sun protection. Methods and Material: The present study is a descriptive cross-sectional study including 577 participants from the general population of Makkah city, Saudi Arabia using an online pretested Arabic questionnaire designed via Google Forms. Results: More than three-quarters of the respondents (78.4%) stated that sun exposure is harmful; of these, 61.9% stated that tanning, pigmentation, burns, skin cancer, and aging are potential risks that result from sun exposure. Further, 39.5% of the participants sometimes used sunscreen, while 23.9% of them regularly used sunscreen when exposed to the sun; the majority (75.1%) was unaware of the different forms of sunscreens. The factors associated with the regular use of sunscreen were female gender, aged between 18-25 years, and single. The majority of the respondents admitted that sunscreen use is necessary for protection against harmful ultraviolet radiation (88.9%); however, only 34.7% of them used other protective methods such as avoiding exposure to the sun (84.0%) and seeking shade (72.0%). Conclusions: According to the results, various attitudes toward the usage of sunscreen were found. Most of the respondents believed that exposure to the sun are harmful. However, the rate of sunscreen use by our population was average despite their reasonable awareness of the effects of sun exposure. This implies the need for health education campaigns and programs.

Inhibitory Effects of Polyphenol- and Flavonoid-Enriched Rice Seed Extract on Melanogenesis in Melan-a Cells via MAPK Signaling-Mediated MITF Downregulation.

Melanin production is an important process that prevents the host skin from harmful ultraviolet radiation; however, an overproduction of melanin results in skin diseases. In the present study, we determined the antioxidative and anti-melanogenic activities of polyphenol- and flavonoid-enriched rice seed extracts in melan-a cells. The polyphenol and flavonoid content of Hopum (HP) and Sebok (SB) rice seed extracts was measured. The antioxidant capacity was determined using the ABTS radical scavenging method. SB contained high amounts of polyphenols and flavonoids, which significantly increased antioxidative activity compared with HP. Various concentrations of these extracts were evaluated in a cytotoxicity using melan-a cells. At 100 µg/mL, there was no significant difference for all treatments compared with untreated cells. Therefore, 100 µg/mL was selected as a concentration for the further experiments. SB significantly suppressed the phosphorylation/activation of p-38 MAPK, increased the expression of phosphorylated ERK 1/2 and Akt, and downregulated the microphthalmia-associated transcription factor (MITF). This resulted in decreased levels of tyrosinase and tyrosinase-related protein-1 and -2. These results indicate the potential of polyphenol- and flavonoid-enriched rice seed as a treatment for hyperpigmentation.

Ultraviolet Radiation Transmission in Buildings’ Fenestration: Part I, Detection Methods and Approaches Using Spectrophotometer and Radiometer

Fenestration, comprising windows and other openings in a building, influences occupant health and well-being while also enhancing energy efficiency through optimized design and placement. Selecting glazing materials that block or filter harmful UV radiation is crucial, as is having reliable methods to measure their UV transmission. This research paper, which comprises Part I of II, conducts an exhaustive analysis of the predominant methodologies and associated challenges inherent in assessing ultraviolet (UV) radiation transmission and deterioration status in fenestration, with particular emphasis on the usage of spectrophotometers and radiometers. It details the economic and operational challenges associated with these instruments and the limitations they pose in terms of sample size and the impact of glazing material degradation over time. Additionally, the paper provides a comparative analysis of UV radiation transmission characteristics across different glazing configurations such as green or yellow patterned glass, laminate glass, clear glass treated with UV protection film, and float glass. The review identifies laminated glass material as offering the best protection. Although spectrophotometers and radiometers offer high levels of accuracy in transmission data detection, their adoption is hindered by considerable financial and operational challenges. The paper underscores the need for developing alternative methodologies that are economically viable, operationally less complex, and are capable of overcoming the limitations of the traditional methods of detection, which will facilitate optimal fenestration configurations for UV protection and energy efficiency in buildings. The proposed Part II paper will explore UV imaging, image processing, and computer vision techniques as potential alternative approaches.

Knowledge and practice of sunscreen use among medical students at Patan Academy of Health Sciences, Nepal

Introduction: (259 words) Sunscreen is essential in preventing skin damage caused by harmful ultraviolet radiation. Regular and appropriate sunscreen application delays photoaging and reduces skin cancer risk. This study aims to assess the general knowledge and practice of sunscreen among medical undergraduates in Nepal.

Metal-rich stars are less suitable for the evolution of life on their planets

Atmospheric ozone and oxygen protect the terrestrial biosphere against harmful ultraviolet (UV) radiation. Here, we model atmospheres of Earth-like planets hosted by stars with near-solar effective temperatures (5300 to 6300 K) and a broad range of metallicities covering known exoplanet host stars. We show that paradoxically, although metal-rich stars emit substantially less ultraviolet radiation than metal-poor stars, the surface of their planets is exposed to more intense ultraviolet radiation. For the stellar types considered, metallicity has a larger impact than stellar temperature. During the evolution of the universe, newly formed stars have progressively become more metal-rich, exposing organisms to increasingly intense ultraviolet radiation. Our findings imply that planets hosted by stars with low metallicity are the best targets to search for complex life on land.

Genetic and phenotype recovery of Ananas comosus var. MD2 in response to ionizing radiation

Due to their sessile nature, plants are exposed to various environmental stressors such as exposure to high levels of harmful ultraviolet (UV), ionizing, and non-ionizing radiations. This exposure may result in various damages, ranging from DNA and chromosomal aberrations to phenotypic abnormalities. As an adaptation, plants have evolved efficient DNA repair mechanisms to detect and repair any damage caused by exposure to these harmful stressors to ensure their survival. In this study, the effects of gamma radiation (as a source of ionizing radiation) on clonal Ananas comosus var. MD2 was evaluated. The morphology and physiology of the clonal plantlets before and after exposure to gamma radiation were monitored at specific time intervals. The degree of genetic variation between the samples pre- and post-irradiation was also analyzed by using inter-simple sequence repeat (ISSR) markers. The resulting data revealed that the heights of the irradiated plantlets were significantly reduced (compared to control), but improved with the recovery period. Irradiated samples also exhibited relatively good photosynthetic efficiency that further improved as the plantlets recover. These observations were supported by the ISSR analysis, where the genetic dissimilarities between the irradiated samples and control were reduced by 0.1017, after 4 weeks of recovery. Overall, our findings suggested that the phenotype recovery of the clonal A. comosus var. MD2 plantlets was contributed by their ability to detect and repair the DNA lesions (as exemplified by the reduction in genetic dissimilarity after 4 weeks) and hence allow the plantlets to undergo phenotype reversion to normal plant stature.

Perception, knowledge and attitude of solar radiation diseases and use of sun screen among Al Zawia Medical University Students in Libya

Human exposure to solar radiation has significant public health implications. Warning of harm associated with overexposure to UV has been demonstrated in numerous Studies. The harmful ultraviolet radiation of sunlight can damage skin cells and affect the skin’s normal appearance. The short term effects associated with sun exposure include acute skin damage associated with changes such as sunburn, and the long term effects are delayed pigmentation, impaired vitamin D synthesis, altered immunological responses of the skin, and others. Sun protection is a key primary preventive strategy against skin cancer and skin damage induced by sun exposure. Sunscreens are cosmetic formulations withthe function of blocking ultraviolet (UV) radiation from penetrating the skin when it is exposed to it. Actually, they absorb or reflect the UV radiation on the skin exposed to sunlight and also help protect against sunburn or any other dangerous effect. The aim of the studywas to determine, evaluate the awareness and knowledge of UV radiation diseases,also the prevalence of sunscreen, attitudes and perceptions toward their use among University Medical Students in Zawia (Libya) were indicated. Data collection was done with the help of aspecial-designed, self-structured questionnaire, which was distributed among 100 samples. The majority (74%) of the sample participants were Pharmacy students, while 16% were Medicine students, and only 10% were Dentistry students. The results showed that 93% of participants had awareness or knowledge, of sun diseases, but only 7% lacked information of aboutradiation diseases. 71% of participants applied sunscreen, whereas 29% of participants did not apply sunscreen. The students at Zawia Medical University have adequate knowledge and were aware of the harmful effects of solar radiation exposure. Sunscreens are an important part of sun protective habits.Our study spotted that the need for future health education programs for our society that emphasis on the significant importance of sunscreen, in addition to the correct methods of application.

Extracts from European Propolises as Potent Tyrosinase Inhibitors.

Tyrosinase is a key enzyme in the melanogenesis pathway. Melanin, the product of this process, is the main pigment of the human skin and a major protection factor against harmful ultraviolet radiation (UVR). Increased melanin synthesis due to tyrosinase hyperactivity can cause hyperpigmentation disorders, which in consequence causes freckles, age spots, melasma, or postinflammatory hyperpigmentation. Tyrosinase overproduction and hyperactivity are triggered by the ageing processes and skin inflammation as a result of oxidative stress. Therefore, the control of tyrosinase activity is the main goal of the prevention and treatment of pigmentation disorders. Natural products, especially propolis, according to their phytochemical profile abundant in polyphenols, is a very rich resource of new potential tyrosinase inhibitors. Therefore, this study focused on the assessment of the tyrosinase inhibitory potential of six extracts obtained from the European propolis samples of various origins. The results showed the potent inhibitory activity of all tested propolis extracts towards commercially available mushroom tyrosinase. The four most active propolis extracts showed inhibitory activity in the range of 86.66-93.25%. Apart from the evaluation of the tyrosinase inhibition, the performed research included UHPLC-DAD-MS/MS (ultra high performance liquid chromatography coupled with diode array detection and tandem mass spectrometry) phytochemical profiling as well as antioxidant activity assessment using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the 2,2"-azino-bis(3-ethylbenzothiazoline-6-sulfuric acid (ABTS) radical scavenging tests. Moreover, statistical analysis was used to correlate the tyrosinase inhibitory and antioxidant activities of propolis extracts with their phytochemical composition. To summarise, the results of our research showed that tested propolis extracts could be used for skin cosmeceutical and medical applications.

Formulation and evaluation of cost effective herbal sunscreen gel from aqueous extracts of different fruits of Mizoram, India

Background: Herbal cosmetics have been in tremendous demand in the market due to their unique properties and minimal side effects. The popularity of herbal cosmetics is mainly due to the effect produced by the herbal extract used and its inherent suitability for routine use in daily life. Herbal cosmetics also avoid adverse effects compared to synthetic products.
 Herbal extracts show remarkable photo protection owing to their ability to absorb ultraviolet (UV) rays, and antioxidant, anti-inflammatory, and immunomodulatory properties. Moreover, herbal cosmetics offer the means of less costly products compared to synthetic ones. Therefore, the aim of the present study was to formulate and evaluate cost-effective herbal sunscreen gel containing aqueous fruit extract of Emblica Officinalis (Indian gooseberry) belonging to the family Euphorbiaceae, Daucus carota (Carrot), family- Apiaceae, Carica papaya (Papaya), family-Caricaceae, Punica granatum (pomegranate), family-Punicaceae and latex of leaves of Aloe barbadensis, family-Liliaceae. 
 Methods: The fruits were grinded with a mixer grinder, extracted with distilled water, and then filtered. The Sun protection factor (SPF) of the extracts was determined using a UV visible spectrophotometer followed by different formulations (F1, F2, F3) of sunscreen gel. 
 Results: The SPF value of the herbal extract of Indian gooseberry, Carrot, Aloe Vera, Papaya, and Pomegranate were found to be 0.779±0.616, 2.527±2.213, 0.349±0.318, 2.794±2.976, 2.468±2.313 respectively. The SPF values of formulated gel F1, F2, and F3 are 5.293 ± 0.680, 3.537 ± 0.494, and 3.914± 0.501 respectively. Among the formulations, F1 showed the highest SPF value and better physicochemical properties. After accelerated stability studies, formulated sunscreen did not loss its potency. 
 Conclusions: We can conclude that formulated herbal sunscreen gel may protect skin from harmful UV radiation and can be used as an alternative source of cost-effective sunscreen formulations.

BaTiO3 Nanoparticles Embedded Antibacterial Cotton Fabric with UV Protection Characteristics

ABSTRACT Barium Titanate (BaTiO3) nanoparticles were mixed with a stock paste containing an acrylate-based binder to prepare pigment paste. The formulated paste was applied to the cotton fabric by utilizing screen printing followed by drying and curing. The coated fabric was characterized for surface and elemental composition and uniform deposition of BaTiO3 nanoparticles was observed with minimal agglomeration. The resultant fabric showed an effective bacterial reduction greater than 99% against Escherichia coli and Staphylococcus aureus, and after 15 laundering cycles, the modified fabric showed a bacterial reduction of over 98%. The loaded fabric is capable of blocking harmful ultraviolet (UV) radiations. The modification of the cotton surface did not significantly change its intrinsic properties like water vapor permeability, air permeability, fabric stiffness, and other mechanical properties. The developed product has considerable possibilities and provides a good substitute for antibiotic materials for use in medical products and everyday apparel.

Skin Cancer Lesions Classification Using Probabilistic Neural Network

One of the most frequent types of cancer is skin cancer. Skin cancer is one of a deadly disease caused due to the abnormal skin cell proliferation in the epidermis resulting in the formation of mass called as Tumor. The formed tumor can be cancerous known as Malignant, that is it can raise and can open out to the rest of the body and the other is non-cancerous tumor known as benign which can raise but it does not open out to the rest of the parts. Skin cancer is mainly caused because of exposure of skin to the harmful UV(Ultraviolet) radiation. If skin cancer is detected in early stage then there are high chances for successful skin cancer treatment. In this paper we are describing a model which uses deep learning technique and some Image processing techniques for distinguishing of skin cancer as benign tumor or malignant tumor. The proposed model gives results in less time and eliminates the cost compared to the formal strategy that is Biopsy which is used for skin cancer recognition. The proposed model uses image processing techniques like Pre-processing, different Segmentation techniques, Feature Extraction and deep learning technique PNN (Probabilistic Neural Network) is used for classification of the skin image.

Sulfur-isotope anomalies recorded in Antarctic ice cores as a potential proxy for tracing past ozone layer depletion events.

Changes in the cosmic-ray background of the Earth can impact the ozone layer. High-energy cosmic events [e.g. supernova (SN)] or rapid changes in the Earth's magnetic field [e.g. geomagnetic Excursion (GE)] can lead to a cascade of cosmic rays. Ensuing chemical reactions can then cause thinning/destruction of the ozone layer-leading to enhanced penetration of harmful ultraviolet (UV) radiation toward the Earth's surface. However, observational evidence for such UV "windows" is still lacking. Here, we conduct a pilot study and investigate this notion during two well-known events: the multiple SN event (≈10 kBP) and the Laschamp GE event (≈41 kBP). We hypothesize that ice-core-Δ33S records-originally used as volcanic fingerprints-can reveal UV-induced background-tropospheric-photochemical imprints during such events. Indeed, we find nonvolcanic S-isotopic anomalies (Δ33S ≠ 0‰) in background Antarctic ice-core sulfate during GE/SN periods, thereby confirming our hypothesis. This suggests that ice-core-Δ33S records can serve as a proxy for past ozone-layer-depletion events.