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UV radiation

Ang Li, Xiang Li, Xujiang Yu, Wei Li, Ruyi Zhao, Xiao An, Daxiang Cui, Xiaoyuan Chen, Wanwan Li
In this work, we report a successful synthesis of copper bismuth sulfide nanorods (NRs) with broad and strong photoabsorption ranging from ultraviolet (UV) to near-infrared (NIR) wavelengths, which can be used as a 1064 nm-laser-driven photothermal agent with the photothermal conversion efficiency of 40.7%, noticeably higher than most of the reported PTT agents working in NIR-II window. The as-prepared PEGylated Cu3BiS3 NRs were used as photoacoustic imaging (PAI) and CT imaging agents due to their strong NIR absorption and large X-ray attenuation coefficient of bismuth...
October 12, 2016: Biomaterials
Caifeng Jiao, Pei Wang, Runqiang Yang, Lu Tian, Zhenxin Gu
In this study, in order to investigate the role of inositol 1,4,5-trisphosphate (IP3) in nitric oxide-guanosine 3',5'-cyclic monophosphate (NO-cGMP)-induced isoflavone accumulation in soybean sprouts under UV-B radiation, the sprouts were treated with donors and inhibitors of NO and cGMP as well as IP3 inhibitor. Results show that NO, with cGMP as a second messenger, stimulates IP3 accumulation under UV-B radiation. Consistent with the increase in IP3 content, the up-regulation of gene and protein expression of phosphoinositide-specific phospholipase C (PI-PLC) in response to sodium nitroprusside (SNP) (exogenous NO donor) and 8-Br-cGMP (cGMP analog) was also observed...
October 21, 2016: Journal of Agricultural and Food Chemistry
Bice S Martincigh, Moses A Ollengo
The photostabilizing ability of grape seed extract on three common sunscreen absorbers: 2-ethylhexyl-p-methoxcinnamate (EHMC), benzophenone-3 (BP3) and tert-butylmethoxy dibenzoylmethane (BMDBM), was investigated. Samples were exposed to simulated solar radiation and monitored by spectrophotometric and chromatographic methods. The chemical composition of the grape seed extract was determined by GC-MS and HPLC-MS and the major secondary metabolites were found to be epicatechin and catechin. Exposure of the extract to UV radiation increased the UV absorption capacity of the extract...
October 19, 2016: Photochemistry and Photobiology
Angela Privat-Maldonado, Deborah O'Connell, Emma Welch, Roddy Vann, Marjan W van der Woude
Low temperature plasmas (LTPs) generate a cocktail of reactive nitrogen and oxygen species (RNOS) with bactericidal activity. The RNOS however are spatially unevenly distributed in the plasma. Here we test the hypothesis that this distribution will affect the mechanisms underpinning plasma bactericidal activity focussing on the level of DNA damage in situ. For the first time, a quantitative, single cell approach was applied to assess the level of DNA damage in bacteria as a function of the radial distance from the centre of the plasma jet...
October 19, 2016: Scientific Reports
Svatopluk Binder, Adéla Hanáková, Kristína Tománková, Klára Pížová, Robert Bajgar, Barbora Manišová, Kristina Kejlová, Hana Bendová, Dagmar Jírová, Hana Kolářová
AIM: Natural or artificial substances have become an inseparable part of our lives. It is questionable whether adequate testing has been performed in order to ensure these substances do not pose a serious health risk. The principal aim of our research was to clarify the potential risk of adding essential oils to food, beverages and cosmetic products. METHODS: The toxicity of substances frequently employed in cosmetics, aromatherapy and food industry (bergamot oil, Litsea cubeba oil, orange oil, citral) were investigated using cell line NIH3T3 (mouse fibroblasts) with/without UV irradiation...
September 2016: Central European Journal of Public Health
Anders Sandell, Davide Ragazzon, Andreas Schaefer, Mari Helene Farstad, Anne Borg
We present a dedicated synchrotron radiation photoelectron spectroscopy (SR-PES) study of a photochemical reaction on the surface of rutile TiO2(110). The photoreaction kinetics of carboxylate species (trimethyl acetate, TMA) upon irradiation by UV and soft x-rays were monitored and we show that it is possible to control the reaction rates from UV light and soft x-rays independently. We directly observe Ti4+ → Ti3+ conversion upon irradiation, attributed to electron trapping at Ti sites close to surface OH groups formed by deprotonation of the parent molecule, trimethyl acetic acid (TMAA)...
October 18, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
Masaatsu Miyauchi, Hideaki Nakajima
UV radiation contains erythemally-weighted UV, as well as UV that synthesizes vitamin D3 . Here, we attempted to determine the relationship between these factors by numerical simulation of atmospheric parameters, such as total ozone, using a simplified "SMART2″ model for radiative transfer. Both forms of UV were almost linearly correlated with each other for a comparably large UV radiation exposure, larger than UV Index ~ 1.6. If erythemally-weighted UV, which carries a risk of sunburn, is known, the amount of UV exposure needed for vitamin D synthesis in the epidermis can be estimated using this relationship...
October 18, 2016: Photochemistry and Photobiology
Olaf Gefeller, Wolfgang Uter, Annette B Pfahlberg
During childhood, parents play a vital role in sun protection of their children. Their guidance is essential for avoiding excessive exposure to ultraviolet (UV) radiation, a risk factor for developing skin cancer in later life. In a population-based cross-sectional study conducted between October 2011 and February 2012, we assessed how 3281 parents implemented sun protection for their three- to six-year-old children in practice. In particular, clothing, shade-seeking behavior, wearing of sunhats and sunglasses, use of sunscreens and the amount of time spent outdoors were ascertained in two settings (beach, garden/playground)...
October 14, 2016: International Journal of Environmental Research and Public Health
Hua Yao, Xuwen Li, Ying Liu, Qian Wu, Yongri Jin
BACKGROUND: Rare ginsenosides in Panax quinquefolius L. have strong bioactivities. The fact that it is hard to obtain large amounts of rare ginsenosides seriously restricts further research on these compounds. An easy, fast, and efficient method to obtain different kinds of rare ginsenosides simultaneously and to quantify each one precisely is urgently needed. METHODS: Microwave-assisted extraction (MAE) was used to extract nine kinds of rare ginsenosides from P...
October 2016: Journal of Ginseng Research
Nicole Regier, Rebecca Beauvais-Flück, Vera I Slaveykova, Claudia Cosio
The hypothesis that increased UV radiation result in co-tolerance to Hg toxicity in aquatic plants was studied at the physiological and transcriptomic level in Elodea nuttallii. At the transcriptomic level, combined exposure to UV+Hg enhanced the stress response in comparison with single treatments, affecting the expression level of transcripts involved in energy metabolism, lipid metabolism, nutrition, and redox homeostasis. Single and combined UV and Hg treatments dysregulated different genes but with similar functions, suggesting a fine regulation of the plant to stresses triggered by Hg, UV and their combination but lack of co-tolerance...
October 6, 2016: Aquatic Toxicology
Taeko Mizutani, Hijiri Sumida, Yuki Sagawa, Yuri Okano, Hitoshi Masaki
BACKGROUND: Carbonylated proteins (CPs) are generated by the reaction of basic amino acid residues in proteins with aldehyde compounds produced during lipid peroxidation. CPs in the stratum corneum (SC) impact skin conditions such as skin moisture functions including water content and transepidermal water loss (TEWL). In addition, CPs can be frequently seen in the SC from sun-exposed sites compared with sun-protected sites. OBJECTIVE: The aim of this study was to reveal whether CPs could be a generation source of reactive oxygen species (ROS) in the SC following exposure to ultraviolet (UV) radiation and to identify the type of ROS and its generation mechanism...
September 28, 2016: Journal of Dermatological Science
Shulin Zhuang, Xuan Lv, Liumeng Pan, Liping Lu, Zhiwei Ge, Jiaying Wang, Jingpeng Wang, Jinsong Liu, Weiping Liu, Chunlong Zhang
Benzotriazole ultraviolet stabilizers (BUVSs) are prominent chemicals widely used in industrial and consumer products to protect against ultraviolet radiation. They are becoming contaminants of emerging concern since their residues are frequently detected in multiple environmental matrices and their toxicological implications are increasingly reported. We herein investigated the antiandrogenic activities of eight BUVSs prior to and after human CYP3A4-mediated metabolic activation/deactivation by the two-hybrid recombinant human androgen receptor yeast bioassay and the in vitro metabolism assay...
October 12, 2016: Environmental Pollution
Petr Porcal, Kristýna Frejlachová, Jiří Kopáček, Jiří Nedoma, Tereza Šavrdová
The photochemical transformation of terrestrial dissolved organic carbon (DOC) in surface waters exposed to UV radiation causes the precipitation of metal (Al and Fe) bearing complexes with high phosphorus sorption capacities. To better elucidate this process, a series of laboratory experiments was performed with stream and river waters with pH range from 3.5 to 8.2 and concentrations of dissolved reactive phosphorus from 2 to 142 μg L(-1). Samples were filtered (0.4 μm) and UV (350 nm) irradiated for 24 h at 68 W m(-2), i...
October 12, 2016: Chemosphere
Timothy A Johnson, Elisa A Rehak, Sushant P Sahu, David A Ladner, Ezra L Cates
Germicidal UVC radiation is a highly effective, chemical-free tool for bacteria inactivation, but its application is limited to reactors and open areas that can accommodate lamps/LEDs and wiring. A relevant example of problematic bacterial colonization within UV-inaccessible confines where chemical techniques have found only limited success is biofouling of feed channels in high-pressure membrane elements for water treatment. Herein we demonstrate a unique method of generating UV internally using embedded radioluminescent (RL) particles excited by an external X-ray source...
October 14, 2016: Environmental Science & Technology
Roger M Pallares, Yusong Wang, Suo H Lim, Nguy N T K Thanh, Xiaodi Su
AIM: To develop a novel plasmonic nanosensing technique to monitor the exposure levels of UV light for sunlight disease prevention. METHODS: Anisotropic gold nanoparticles were grown inside a UV photoresponsive fluid, which was previously exposed to UV radiation from different sources. The morphology and optical properties of the obtained nanoparticles were monitored by spectroscopy and microscopy. RESULTS: The morphological and optical properties of the nanoparticles were dependent on the UV dose...
October 14, 2016: Nanomedicine
Izaskun Jiménez-Serra, Anton I Vasyunin, Paola Caselli, Nuria Marcelino, Nicolas Billot, Serena Viti, Leonardo Testi, Charlotte Vastel, Bertrand Lefloch, Rafael Bachiller
The detection of complex organic molecules (COMs) toward cold sources such as pre-stellar cores (with T<10 K), has challenged our understanding of the formation processes of COMs in the interstellar medium. Recent modelling on COM chemistry at low temperatures has provided new insight into these processes predicting that COM formation depends strongly on parameters such as visual extinction and the level of CO freeze out. We report deep observations of COMs toward two positions in the L1544 pre-stellar core: the dense, highly-extinguished continuum peak with A V ≥30 mag within the inner 2700 au; and a low-density shell with average A V ~7...
October 10, 2016: Astrophysical Journal. Letters
Alexandra Pontefract, Gordon R Osinski, Charles S Cockell, Gordon Southam, Phil J A McCausland, Joseph Umoh, David W Holdsworth
Impact-generated lithologies have recently been identified as viable and important microbial habitats, especially within cold and arid regions such as the polar deserts on Earth. These unique habitats provide protection from environmental stressors, such as freeze-thaw events, desiccation, and UV radiation, and act to trap aerially deposited detritus within the fissures and pore spaces, providing necessary nutrients for endoliths. This study provides the first culture-independent analysis of the microbial community structure within impact-generated lithologies in a Mars analog environment, involving the analysis of 44,534 16S rRNA sequences from an assemblage of 21 rock samples that comprises three shock metamorphism categories...
October 2016: Astrobiology
Daniel A Thomas, Matthew M Coggon, Hanna Lignell, Katherine Ann Schilling, Xuan Zhang, Rebecca H Schwantes, Richard C Flagan, John H Seinfeld, Jesse Lee Beauchamp
The complexation of iron (III) with oxalic acid in aqueous solution yields a strongly absorbing chromophore that undergoes efficient photodissociation to give iron (II) and the carbon dioxide anion radical. Importantly, iron (III) oxalate complexes absorb near-UV radiation (λ > 350 nm), providing a potentially powerful source of oxidants in aqueous tropospheric chemistry. Although this photochemical system has been studied extensively, the mechanistic details associated with its role in the oxidation of dissolved organic matter within aqueous aerosol remain largely unknown...
October 12, 2016: Environmental Science & Technology
A C Weihermann, M Lorencini, C A Brohem, C M de Carvalho
Skin aging is a complex process that may be caused by factors that are intrinsic and extrinsic to the body. Ultraviolet (UV) radiation represents one of the main sources of skin damage over the years and characterizes a process known as photoaging. Among the changes that affect cutaneous tissue with age, the loss of elastic properties caused by changes in elastin production, increased degradation and/or processing produces a substantial impact on tissue esthetics and health. The occurrence of solar elastosis is one of the main markers of cutaneous photoaging and is characterized by disorganized and non-functional deposition of elastic fibers...
October 12, 2016: International Journal of Cosmetic Science
Kang Song, Xiaohong Wang, Qun Xiang, Jiaqiang Xu
Herein, we demonstrate experimentally the coexistence of photocatalytic dual opposite roles of Au nanoparticles in a UV-vis light irradiated Au/TiO2 system. We have investigated that the photocatalytic performance curves of Au/TiO2 and CdS/Au/TiO2 for degradation of methylene blue (MB) all present a V-shape with different radiation power ratios. However, through the comparison of photocatalytic activities of Au/TiO2 and CdS/Au/TiO2 by statistics and mathematical simulation, we propose qualitatively that the deposition of CdS used as a photosensitizer could extend the Au/TiO2 light absorption range and weaken the negative effect of Au/TiO2...
October 12, 2016: Physical Chemistry Chemical Physics: PCCP
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