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https://www.readbyqxmd.com/read/27875881/communication-position-does-matter-the-photofragmentation-of-the-nitroimidazole-isomers
#1
P Bolognesi, A R Casavola, A Cartoni, R Richter, P Markus, S Borocci, J Chiarinelli, S Tošić, H Sa'adeh, M Masič, B P Marinković, K C Prince, L Avaldi
A combined experimental and theoretical approach has been used to disentangle the fundamental mechanisms of the fragmentation of the three isomers of nitroimidazole induced by vacuum ultra-violet (VUV) radiation, namely, 4-, 5-, and 2-nitroimidazole. The results of mass spectrometry as well as photoelectron-photoion coincidence spectroscopy display striking differences in the radiation-induced decomposition of the different nitroimidazole radical cations. Based on density functional theory (DFT) calculations, a model is proposed which fully explains such differences, and reveals the subtle fragmentation mechanisms leading to the release of neutral species like NO, CO, and HCN...
November 21, 2016: Journal of Chemical Physics
https://www.readbyqxmd.com/read/27818724/surface-degradation-and-nanoparticle-release-of-a-commercial-nanosilica-polyurethane-coating-under-uv-exposure
#2
Deborah S Jacobs, Sin-Ru Huang, Yu-Lun Cheng, Savelas A Rabb, Justin M Gorham, Peter J Krommenhoek, Lee L Yu, Tinh Nguyen, Lipiin Sung
Many coatings properties such as mechanical, electrical, and ultra violet (UV) resistance are greatly enhanced by the addition of nanoparticles, which can potentially increase the use of nanocoatings for many outdoor applications. However, because polymers used in all coatings are susceptible to degradation by weathering, nanoparticles in a coating may be brought to the surface and released into the environment during the life cycle of a nanocoating. Therefore, the goal of this study is to investigate the process and mechanism of surface degradation and potential particle release from a commercial nanosilica/polyurethane coating under accelerated UV exposure...
September 2016: Journal of Coatings Technology and Research
https://www.readbyqxmd.com/read/27783061/uv-indices-what-do-they-indicate
#3
REVIEW
Hanns Moshammer, Stana Simic, Daniela Haluza
Ultra-Violet (UV) radiation covers the spectrum of wavelengths from 100 to 400 nm. The potency and biological activity for a variety of endpoints differ by wavelength. For monitoring and communication purposes, different UV action spectra have been developed. These spectra use different weighting functions. The action spectrum for erythemal dose is the most widely used one. This erythemal dose per time or dose-rate has been further simplified into a "UV index". Following this example, in our review we use the term "index" or (plural) "indices" in a more general description for all simplified single-value measures for any biologically effective UV dose, e...
October 24, 2016: International Journal of Environmental Research and Public Health
https://www.readbyqxmd.com/read/27713170/gremlin-inhibits-uv-induced-skin-cell-damages-via-activating-vegfr2-nrf2-signaling
#4
Chao Ji, Jin-Wen Huang, Qiu-Yun Xu, Jing Zhang, Meng-Ting Lin, Ying Tu, Li He, Zhi-Gang Bi, Bo Cheng
Ultra Violet (UV) radiation induces reactive oxygen species (ROS) production, DNA oxidation and single strand breaks (SSBs), which will eventually lead to skin cell damages or even skin cancer. Here, we tested the potential activity of gremlin, a novel vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) agonist, against UV-induced skin cell damages. We show that gremlin activated VEGFR2 and significantly inhibited UV-induced death and apoptosis of skin keratinocytes and fibroblasts. Pharmacological inhibition or shRNA-mediated knockdown of VEGFR2 almost abolished gremlin-mediated cytoprotection against UV in the skin cells...
October 4, 2016: Oncotarget
https://www.readbyqxmd.com/read/27521253/skin-aging-and-oxidative-stress-equol-s-anti-aging-effects-via-biochemical-and-molecular-mechanisms
#5
REVIEW
Edwin D Lephart
Oxygen in biology is essential for life. It comes at a cost during normal cellular function, where reactive oxygen species (ROS) are generated by oxidative metabolism. Human skin exposed to solar ultra-violet radiation (UVR) dramatically increases ROS production/oxidative stress. It is important to understand the characteristics of human skin and how chronological (intrinsic) aging and photo-aging (extrinsic aging) occur via the impact of ROS production by cascade signaling pathways. The goal is to oppose or neutralize ROS insults to maintain good dermal health...
November 2016: Ageing Research Reviews
https://www.readbyqxmd.com/read/27517753/sc79-protects-retinal-pigment-epithelium-cells-from-uv-radiation-via-activating-akt-nrf2-signaling
#6
Yi-Qing Gong, Wei Huang, Ke-Ran Li, Yuan-Yuan Liu, Guo-Fan Cao, C Cao, Qin Jiang
Excessive Ultra-violet (UV) radiation causes oxidative damages and apoptosis in retinal pigment epithelium (RPE) cells. Here we tested the potential activity of SC79, a novel small molecule activator of Akt, against the process. We showed that SC79 activated Akt in primary and established (ARPE-19 line) RPE cells. It protected RPE cells from UV damages possibly via inhibiting cell apoptosis. Akt inhibition, via an Akt specific inhibitor (MK-2206) or Akt1 shRNA silence, almost abolished SC79-induced RPE cytoprotection...
August 9, 2016: Oncotarget
https://www.readbyqxmd.com/read/27504344/changing-trends-of-skin-cancer-a-tertiary-care-hospital-study-in-malwa-region-of-punjab
#7
Sonal Tina Lal, Raja Paramjeet Singh Banipal, Deepak John Bhatti, Hanuman Prasad Yadav
INTRODUCTION: Skin cancer constitutes a small but significant proportion of patients with cancer. Although the presence of eumelanin in dark skin is protective against the development of skin cancer, it is increasingly being diagnosed in the Indian population. AIM: To study the profile of skin cancer patients presenting to a tertiary hospital in Malwa area of Punjab, India. MATERIALS AND METHODS: Retrospective study was done to analyse the profile of skin cancer patients who attended the institution over one year from 1(st) December 2013 to 30(th) November 2014...
June 2016: Journal of Clinical and Diagnostic Research: JCDR
https://www.readbyqxmd.com/read/27433654/manipulation-of-tio2-nanotubes-in-a-transparent-dielectrophoretic-device
#8
Ji-Yun Seon, Young Joon Yoon, Chang-Yeoul Kim, Hyo Tae Kim
A DEP device with a transparent oxide thin film electrode was fabricated by a photolithography process and sputtering deposition with indium tin oxide (ITO). In order to form a fine ITO electrode pattern, we manipulated the negative slope using a photoresist by controlling the intensity of the ultra-violet radiation and the exposure time. In this study, the motions of a 1 microm polystyrene sphere and TiO2 nanotube were observed as a function of the applied voltage and the frequency. The findings confirm that TiO2 nanotubes can be manipulated by a p-DEP force and that they can be effectively aligned under conditions of 10 V(p-p) at 750 Hz...
February 2016: Journal of Nanoscience and Nanotechnology
https://www.readbyqxmd.com/read/27232425/lifetime-prevalence-of-non-melanoma-and-melanoma-skin-cancer-in-australian-recreational-and-competitive-surfers
#9
Mike Climstein, James Furness, Wayne Hing, Joe Walsh
BACKGROUND/PURPOSE: Surfing is one of the most popular outdoor aquatic activities in Australia with an estimated 2.7 million recreational surfers; however, Australia has long been recognized as having the highest incidence of melanoma in the world, and it is the most common type of cancer in young Australians. The aim of this study was to investigate the lifetime prevalence of non-melanoma [basal cell carcinoma (BCC), squamous cell carcinoma (SCC)] and melanoma skin cancers in Australian recreational and competitive surfers...
July 2016: Photodermatology, Photoimmunology & Photomedicine
https://www.readbyqxmd.com/read/27215947/mitochondrial-damage-and-ageing-using-skin-as-a-model-organ
#10
Laura Hudson, Amy Bowman, Eyman Rashdan, Mark A Birch-Machin
Ageing describes the progressive functional decline of an organism over time, leading to an increase in susceptibility to age-related diseases and eventually to death, and it is a phenomenon observed across a wide range of organisms. Despite a vast repertoire of ageing studies performed over the past century, the exact causes of ageing remain unknown. For over 50 years it has been speculated that mitochondria play a key role in the ageing process, due mainly to correlative data showing an increase in mitochondrial dysfunction, mitochondrial DNA (mtDNA) damage, and reactive oxygen species (ROS) with age...
May 7, 2016: Maturitas
https://www.readbyqxmd.com/read/27166545/skin-cancer-etiology-and-management
#11
REVIEW
Muhammad Imran Qadir
Nowadays, occurrence of skin cancer is very common in humans. It is reported that the most common cause of the skin cancer is excessive exposure to sunlight as it contains harmful radiations; the ultra violet rays. Different management strategies are used for different types of skin cancers, which are chemotherapy, radiation therapy.
May 2016: Pakistan Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/27164422/wedelolactone-mitigates-uvb-induced-oxidative-stress-inflammation-and-early-tumor-promotion-events-in-murine-skin-plausible-role-of-nfkb-pathway
#12
Farrah Ali, Bilal Azhar Khan, Sarwat Sultana
UVB (Ultra-violet B) radiation is one of the major etiological factors in various dermal pathology viz. dermatitis, actinic folliculitis, solar urticaria, psoriasis and cancer among many others. UVB causes toxic manifestation in tissues by inciting inflammatory and tumor promoting events. We have designed this study to assess the anti-inflammatory and anti-tumor promotion effect of Wedelolactone (WDL) a specific IKK inhibitor. Results indicate significant restoration of anti-oxidative enzymes due to WDL treatments...
September 5, 2016: European Journal of Pharmacology
https://www.readbyqxmd.com/read/27151674/3h-1-2-dithiole-3-thione-protects-retinal-pigment-epithelium-cells-against-ultra-violet-radiation-via-activation-of-akt-mtorc1-dependent-nrf2-ho-1-signaling
#13
Ke-Ran Li, Su-Qing Yang, Yi-Qing Gong, Hong Yang, Xiu-Miao Li, Yu-Xia Zhao, Jin Yao, Qin Jiang, Cong Cao
Excessive UV radiation and reactive oxygen species (ROS) cause retinal pigment epithelium (RPE) cell injuries. Nrf2 regulates transcriptional activation of many anti-oxidant genes. Here, we tested the potential role of 3H-1,2-dithiole-3-thione (D3T) against UV or ROS damages in cultured RPE cells (both primary cells and ARPE-19 line). We showed that D3T significantly inhibited UV-/H2O2-induced RPE cell death and apoptosis. UV-stimulated ROS production was dramatically inhibited by D3T pretreatment. D3T induced Nrf2 phosphorylation in cultured RPE cells, causing Nrf2 disassociation with KEAP1 and its subsequent nuclear accumulation...
2016: Scientific Reports
https://www.readbyqxmd.com/read/27081309/removal-of-4-nitrophenol-from-water-using-ag-n-p-tridoped-tio2-by-photocatalytic-oxidation-technique
#14
Temesgen Achamo, O P Yadav
Photocatalytic oxidation using semiconductor nanoparticles is an efficient, eco-friendly, and cost-effective process for the removal of organic pollutants, such as dyes, pesticides, phenols, and their derivatives in water. In the present study, nanosize Ag-N-P-tridoped titanium(IV) oxide (TiO2) was prepared by using sol-gel-synthesized Ag-doped TiO2 and soybean (Glycine max) or chickpea (Cicer arietinum) seeds as nonmetallic bioprecursors. As-synthesized photocatalysts were characterized using X-ray diffraction, Fourier transform infrared, and ultra violet (UV)-visible spectroscopic techniques...
2016: Analytical Chemistry Insights
https://www.readbyqxmd.com/read/26963841/varicella-zoster-virus-in-perth-western-australia-seasonality-and-reactivation
#15
Igor A Korostil, David G Regan
BACKGROUND: Identification of the factors affecting reactivation of varicella-zoster virus (VZV) largely remains an open question. Exposure to solar ultra violet (UV) radiation is speculated to facilitate reactivation. Should the role of UV in reactivation be significant, VZV reactivation patterns would generally be expected to be synchronous with seasonal UV profiles in temperate climates. METHODS: We analysed age and gender specific VZV notification time series data from Perth, Western Australia (WA)...
2016: PloS One
https://www.readbyqxmd.com/read/26699040/resonant-enhanced-full-color-emission-of-quantum-dot-based-micro-led-display-technology
#16
Hau-Vei Han, Huang-Yu Lin, Chien-Chung Lin, Wing-Cheung Chong, Jie-Ru Li, Kuo-Ju Chen, Peichen Yu, Teng-Ming Chen, Huang-Ming Chen, Kei-May Lau, Hao-Chung Kuo
Colloidal quantum dots which can emit red, green, and blue colors are incorporated with a micro-LED array to demonstrate a feasible choice for future display technology. The pitch of the micro-LED array is 40 μm, which is sufficient for high-resolution screen applications. The method that was used to spray the quantum dots in such tight space is called Aerosol Jet technology which uses atomizer and gas flow control to obtain uniform and controlled narrow spots. The ultra-violet LEDs are used in the array to excite the red, green and blue quantum dots on the top surface...
December 14, 2015: Optics Express
https://www.readbyqxmd.com/read/26690131/phenolic-phytoalexins-in-rice-biological-functions-and-biosynthesis
#17
REVIEW
Man-Ho Cho, Sang-Won Lee
Phytoalexins are inducible secondary metabolites possessing antimicrobial activity against phytopathogens. Rice produces a wide array of phytoalexins in response to pathogen attacks and environmental stresses. With few exceptions, most phytoalexins identified in rice are diterpenoid compounds. Until very recently, flavonoid sakuranetin was the only known phenolic phytoalexin in rice. However, recent studies have shown that phenylamides are involved in defense against pathogen attacks in rice. Phenylamides are amine-conjugated phenolic acids that are induced by pathogen infections and abiotic stresses including ultra violet (UV) radiation in rice...
December 7, 2015: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/26688710/laboratory-photo-chemistry-of-pahs-ionization-versus-fragmentation
#18
Junfeng Zhen, Pablo Castellanos, Daniel M Paardekooper, Niels Ligterink, Harold Linnartz, Laurent Nahon, Christine Joblin, Alexander G G M Tielens
Interstellar Polycyclic Aromatic Hydrocarbons (PAH) are expected to be strongly processed by Vacuum Ultra-Violet (VUV) photons. Here, we report experimental studies on the ionization and fragmentation of coronene (C24H12), ovalene (C32H14) and hexa-peri-hexabenzocoronene (HBC; C42H18) cations by exposure to synchrotron radiation in the range of 8-40 eV. The results show that for small PAH cations such as coronene, fragmentation (H-loss) is more important than ionization. However, as the size increases, ionization becomes more and more important and for the HBC cation, ionization dominates...
May 1, 2015: Astrophysical Journal. Letters
https://www.readbyqxmd.com/read/26646736/forensic-aspects-of-the-weathering-and-ageing-of-spray-paints
#19
Cédric Jost, Cyril Muehlethaler, Geneviève Massonnet
This paper presents a preliminary study on the degradation of spray paint samples, illustrated by Optical, FTIR and Raman measurements. As opposed to automotive paints which are specifically designed for improved outdoor exposure and protected using hindered amine light absorbers (HALS) and ultra-violet absorbers (UVA), the spray paints on their side are much simpler in composition and very likely to suffer more from joint effects of solar radiation, temperature and humidity. Six different spray paint were exposed to outdoor UV-radiation for a total period of three months and both FTIR and Raman measurements were taken systematically during this time...
January 2016: Forensic Science International
https://www.readbyqxmd.com/read/26641669/changes-of-25-oh-vitamin-d-during-overwintering-at-the-german-antarctic-stations-neumayer-ii-and-iii
#20
Mathias Steinach, Eberhard Kohlberg, Martina Anna Maggioni, Stefan Mendt, Oliver Opatz, Alexander Stahn, Josefine Tiedemann, Hanns-Christian Gunga
PURPOSE: Humans in Antarctica face different environmental challenges, such as low ultra-violet radiation, which is crucial for vitamin D production in humans. Therefore we assessed changes in 25-OH-vitamin D serum concentration during 13 months of overwintering at the German Stations Neumayer II and III (2007-2012). We hypothesized that (i) 25-OH-vitamin D serum concentration would significantly decrease, (ii) changes would be affected by age, gender, baseline (i.e. pre-overwintering) fat mass, baseline 25-OH-vitamin D serum concentration, and station residence, and (iii) our results would not differ from similar previous studies in comparable high latitudes...
2015: PloS One
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