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https://www.readbyqxmd.com/read/28646736/cell-damage-caused-by-ultraviolet-b-radiation-in-the-desert-cyanobacterium-phormidium-tenue-and-its-recovery-process
#1
Gaohong Wang, Songqiang Deng, Jiafeng Liu, Chaoran Ye, Xiangjun Zhou, Lanzhou Chen
Phormidium tenue, a cyanobacterium that grows in the topsoil of biological soil crusts (BSCs), has the highest recovery rate among desert crust cyanobacteria after exposure to ultraviolet B (UV-B) radiation. However, the mechanism underlying its recovery process is unclear. To address this issue, we measured chlorophyll a fluorescence, generation of reactive oxygen species (ROS), lipid peroxidation, and repair of DNA breakage in P. tenue following exposure to UV-B. We found that UV-B radiation at all doses tested reduced photosynthesis and induced cell damage in P...
June 21, 2017: Ecotoxicology and Environmental Safety
https://www.readbyqxmd.com/read/28646308/photochemical-generation-of-reactive-intermediates-from-urban-waste-bio-organic-substances-under-uv-and-solar-irradiation
#2
Marcela Prado Silva, Arlen Mabel Lastre-Acosta, Simón Mostafa, Garrett McKay, Karl G Linden, Fernando L Rosario-Ortiz, Antonio Carlos Silva Costa Teixeira
Singlet oxygen ((1)O2), hydroxyl radicals ((•)OH), and excited triplet states of organic matter ((3)OM(*)) play a key role in the degradation of pollutants in aquatic environments. The formation rates and quantum yields (Φ) of these reactive intermediates (RI) through photosensitized reactions of dissolved organic matter (DOM) have been reported in the literature for decades. Urban biowaste-derived substances (UW-BOS), a form of organic matter derived from vegetative and urban waste, have recently been shown to be efficient sensitizers in the photo-degradation of different contaminants...
June 23, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28646133/effects-of-energetic-ion-irradiation-on-wse2-sic-heterostructures
#3
Tan Shi, Roger C Walker, Igor Jovanovic, Joshua A Robinson
The remarkable electronic properties of layered semiconducting transition metal dichalcogenides (TMDs) make them promising candidates for next-generation ultrathin, low-power, high-speed electronics. It has been suggested that electronics based upon ultra-thin TMDs may be appropriate for use in high radiation environments such as space. Here, we present the effects of irradiation by protons, iron, and silver ions at MeV-level energies on a WSe2/6H-SiC vertical heterostructure studied using XPS and UV-Vis-NIR spectroscopy...
June 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28644497/novel-tunable-green-red-emitting-oxynitride-phosphors-co-activated-with-ce-3-tb-3-and-eu-3-photoluminescence-and-energy-transfer
#4
Jiansheng Huo, Langping Dong, Wei Lü, Baiqi Shao, Hongpeng You
A series of novel Ce(3+), Tb(3+) and Eu(3+) ion doped Y4SiAlO8N-based oxynitride phosphors were synthesized by the solid-state method and characterized by X-ray powder diffraction, scanning electron microscopy, photoluminescence, lifetimes and thermo-luminescence. The excitation of the Ce(3+)/Tb(3+) co-doped and Ce(3+)/Tb(3+)/Eu(3+) tri-doped phosphor with near-UV radiation results in strong linear Tb(3+) green and Eu(3+) red emission. The occurrence of Ce(3+)-Tb(3+) and Ce(3+)-Tb(3+)-Eu(3+) energy transfer processes is responsible for the bright green or red luminescence...
June 23, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28643834/understanding-the-remarkable-luminescence-enhancement-via-sio2-coating-on-tio2-eu-3-nanofibers
#5
Meiqi Chang, Yanhua Song, Ye Sheng, Jie Chen, Haifeng Zou
TiO2:Eu(3+) nanofibers diameters can be tuned by changing the mixed solvent ratio are synthesized via the electrospinning technique. Concentration quenching phenomena and the relationship of the PL intensity ratio I((5)D0-(7)F2)/I((5)D0-(7)F1) with the Eu doping concentration are discussed. Notably, the luminescence intensity is enhanced by about 7.8 fold by coating SiO2 gel layer on the TiO2:Eu(3+) nanofibers, which is successfully performed via a sol-gel process followed by calcination. Furthermore, these fibers are characterized systematically via X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), Fourier transform infrared spectroscopy (FT-IR), and photoluminescence (PL) spectroscopy...
June 23, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28643284/hydroxyl-radical-mediated-degradation-of-diclofenac-revisited-a-computational-approach-to-assessment-of-reaction-mechanisms-and-by-products
#6
Sesil Agopcan Cinar, Asu Ziylan-Yavaş, Saron Catak, Nilsun H Ince, Viktorya Aviyente
Advanced oxidation processes (AOPs) are based on the in situ production of hydroxyl radicals (•OH) and reactive oxygen species (ROS) in water upon irradiation of the sample by UV light, ultrasound, electromagnetic radiation, and/or the addition of ozone or a semiconductor. Diclofenac (DCF), one of the emerging organic contaminants (EOC), is of environmental concern due to its abundancy in water and is known to be subjected to AOPs. The current study uses density functional theory (DFT) to elucidate the mechanisms of the reactions between •OH and DCF leading to degradation by-products, P1-P9...
June 23, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28641207/ros-and-calcium-signaling-mediated-pathways-involved-in-stress-responses-of-the-marine-microalgae-dunaliella-salina-to-enhanced-uv-b-radiation
#7
Xinxin Zhang, Xuexi Tang, Ming Wang, Wei Zhang, Bin Zhou, You Wang
UV-B ray has been addressed to trigger common metabolic responses on marine microalgae, however, the upstream events responsible for these changes in marine microalgae are poorly understood. In the present study, a species of marine green microalgae Dunaliella salina was exposed to a series of enhanced UV-B radiation ranging from 0.25 to 1.00 KJ·m(-2) per day. The role of ROS and calcium signaling in the D. salina responses to UV-B was discussed. Results showed that enhanced UV-B radiation markedly decreased the cell density in a dose-dependent manner, but the contents of protein and glycerol that were essential for cell growth increased...
May 28, 2017: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/28636977/long-term-trend-of-o3-in-a-mega-city-shanghai-china-characteristics-causes-and-interactions-with-precursors
#8
Wei Gao, Xuexi Tie, Jianming Xu, Rujin Huang, Xiaoqing Mao, Guangqiang Zhou, Luyu Chang
In recent years, ozone (O3) is often the major pollutant during summertime in China. In order to better understand this problem, a long-term measurement of ozone (from 2006 to 2015) and its precursors (NOx and VOCs) as well as the photochemical parameter (UV radiation) in a mega city of China (Shanghai) is analyzed. The focus of this study is to investigate the trend of O3 and the causes of the O3 trend in large cities in China. In order to understand the relationship between the O3 precursors and O3 formation, two distinguished different sites of measurements are selected in the study, including an urbanization site (XJH-Xujiahui) and a remote site (DT-Dongtan)...
June 18, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28634159/a-role-for-the-nonsense-mediated-mrna-decay-pathway-in-maintaining-genome-stability-in-caenorhabditis-elegans
#9
Víctor González-Huici, Bin Wang, Anton Gartner
Ionizing radiation (IR) is commonly used in cancer therapy and is a main source of DNA double-strand-breaks (DSBs), one of the most toxic forms of DNA damage. We have used Caenorhabditis elegans as an invertebrate model to identify novel factors required for repair of DNA damage inflicted by IR. We have performed an unbiased genetic screen, finding that smg-1 mutations confer strong hypersensitivity to IR. SMG-1 is a phosphoinositide-3 kinase (PI3K) kinase involved in mediating nonsense-mediated mRNA decay (NMD) of transcripts containing premature stop codons and related to the ATM and ATR kinases which are at the apex of DNA damage signalling pathways...
June 20, 2017: Genetics
https://www.readbyqxmd.com/read/28633754/total-body-skin-examination-adherence-among-young-adults-with-an-increased-risk-for-skin-cancer
#10
Julie Williams Merten, Jessica L King, Erin Largo-Wight
Although ultraviolent radiation exposure and skin cancer rates are rising in the US, there is not a consistent national message calling for routine total body skin examinations (TBSE) by a healthcare provider. This pilot study examined TBSE rates among adults at an increased risk for skin cancer (history of sunburn, indoor tanning use, excessive UV exposure, poor sunscreen use). Overall skin cancer prevention behaviors were insufficient among respondents (n=953) and only a quarter of respondents considered at an increased risk for skin cancer reported a TBSE...
June 15, 2017: Dermatology Online Journal
https://www.readbyqxmd.com/read/28632797/approach-to-management-of-giant-basal-cell-carcinomas
#11
Sarah E Mott, William J Hunter, Edibaldo Silva, Christopher J Huerter
Basal cell carcinoma (BCC) is a common nonmelanoma skin cancer with increasing incidence in the United States and worldwide. It is strongly linked to UV radiation exposure and typically is slow growing. Malignancy in BCCs is due to local growth and invasion rather than metastasis, and the prognosis is generally favorable. We report the case of a 60-year-old man with a large, locally destructive giant BCC on the right side of the upper back that was successfully treated via complete surgical excision (SE) and did not recur in the subsequent 36 months...
May 2017: Cutis; Cutaneous Medicine for the Practitioner
https://www.readbyqxmd.com/read/28630441/overcoming-the-biological-aging-of-titanium-using-a-wet-storage-method-after-ultraviolet-treatment
#12
Sung-Hwan Choi, Won-Seok Jeong, Jung-Yul Cha, Jae-Hoon Lee, Kee-Joon Lee, Hyung-Seog Yu, Eun-Ha Choi, Kwang-Mahn Kim, Chung-Ju Hwang
We evaluated whether the biological activity of the surface of titanium, when stored in an aqueous solution after ultraviolet (UV) treatment, is comparable to that of the surface immediately after UV treatment. We subjected Grade IV titanium discs with machined surfaces to UV radiation for 15 min and then tested them immediately and after storage for 28 days, with and without distilled H2O (dH2O). We evaluated the surface characteristics using surface profiling, contact angle analysis, X-ray photoelectron spectroscopy, and in terms of the surface zeta-potential...
June 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28629073/in-vitro-and-in-vivo-anti-inflammatory-properties-of-green-synthesized-silver-nanoparticles-using-viburnum-opulus-l-fruits-extract
#13
Bianca Moldovan, Luminita David, Adriana Vulcu, Liliana Olenic, Maria Perde-Schrepler, Eva Fischer-Fodor, Ioana Baldea, Simona Clichici, Gabriela Adriana Filip
A green, rapid and cost effective method for the bio-synthesis of silver nanoparticles (AgNPs), using polyphenols present in European cranberry bush fruit extracts was developed. The obtained AgNPs were characterized by ultra-violet visible spectroscopy (UV-VIS), Fourier transform - infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and X-ray diffraction patterns (XRD). The average size of the spherical AgNPs was found to be 25nm. The anti-inflammatory effect of the biomaterials was investigated, both in vitro (on HaCaT cell line, exposed to UVB radiation) and in vivo (on acute inflammation model in Wistar rats)...
October 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28628879/development-of-a-method-for-the-characterization-and-operation-of-uv-led-for-water-treatment
#14
Ataollah Kheyrandish, Madjid Mohseni, Fariborz Taghipour
Tremendous improvements in semiconductor technology have made ultraviolet light-emitting diodes (UV-LEDs) a viable alternative to conventional UV sources for water treatment. A robust and validated experimental protocol for studying the kinetics of microorganism inactivation is key to the further development of UV-LEDs for water treatment. This study proposes a protocol to operate UV-LEDs and control their output as a polychromatic radiation source. In order to systematically develop this protocol, the results of spectral power distribution, radiation profile, and radiant power measurements of a variety of UV-LEDs are presented...
June 6, 2017: Water Research
https://www.readbyqxmd.com/read/28628874/a-building-blocks-strategy-for-preparing-photocatalytically-active-anatase-tio2-rutile-sno2-heterostructures-by-hydrothermal-annealing
#15
Vagner Romito de Mendonça, Waldir Avansi, Raul Arenal, Caue Ribeiro
Effective heterostructures for photocatalysis need to present good electron-hole mobility among phases, a feature that is only attained with satisfactory interface quality. For very small sizes and with a stable colloidal state, the oriented attachment mechanism can be used to prepare suitable structures by means of a building blocks strategy, whereby preformed nanoparticles are used to control the desired amount of each phase in the heterostructure. Here, we show the success of this strategy for anatase TiO2/rutile SnO2 heterostructures, applying conventional hydrothermal annealing, where successive collisions among particles increase the probability of oriented attachment...
June 9, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28628693/understanding-the-role-of-photolyases-photoprotection-and-beyond
#16
Neal Bhatia, Brian Berman, Roger I Ceilley, Leon H Kircik
<p>The limitations of photoprotection modalities have been the inability to arrest the progression of photodamage. Chemoprevention strategies involving a sunscreen has been incomplete because of the need to induce sustained repair of mutations and slow carcinogenesis. Photolyases, or photoreactivation enzymes, serve the role of repairing mutations and damage to DNA induced by ultraviolet (UV) radiation and therefore influence the initiation phases of carcinogenesis. As these enzymes are absent in humans, exogenous forms have been manufactured and are now utilized in topical agents to supplement and augment the innate repair mechanisms that are mostly inefficient...
May 1, 2017: Journal of Drugs in Dermatology: JDD
https://www.readbyqxmd.com/read/28624737/optical-properties-of-the-human-lens-constituents
#17
Ekaterina A Zelentsova, Lyudmila V Yanshole, Anjella Zh Fursova, Yuri P Tsentalovich
The absorption and fluorescence properties of the metabolomic (MET), water-soluble and urea-soluble protein fractions from the middle-age, aged, and cataractous human lenses have been measured. At 280nm and 300nm the major lens absorbers are crystallins, which absorb more than 90% of light in the UV-B region (280-315nm). In middle-aged lenses, the absorption at 360nm is mostly provided by UV filters contained in the MET fraction. With aging, and especially with the cataract development, the absorption of MET fraction in UV-A region (315-400nm) decreases due to the drop of the UV filter concentration, while the absorption of protein fractions increases due to the accumulation of post-translational modifications...
June 3, 2017: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/28624334/seasonality-and-autoimmune-diseases-the-contribution-of-the-four-seasons-to-the-mosaic-of-autoimmunity
#18
REVIEW
Abdulla Watad, Shir Azrielant, Nicola Luigi Bragazzi, Kassem Sharif, Paula David, Itay Katz, Gali Aljadeff, Mariana Quaresma, Galya Tanay, Mohammad Adawi, Howard Amital, Yehuda Shoenfeld
Autoimmune diseases (ADs) are a heterogeneous groups of diseases that occur as a results of loss of tolerance to self antigens. While the etiopathogeneis remain obscure, different environmental factors were suggested to have a role in the development of autoimmunity, including infections, low vitamin D levels, UV radiation, and melatonin. Interestingly, such factors possess seasonal variation patterns that could influence disease development, severity and progression. Vitamin D levels which reach a nadir during late winter and early spring is correlated with increased disease activity, clinical severity as well as relapse rates in several disease entities including multiple sclerosis (MS), non-cutaneous flares of systemic lupus erythematosus (SLE), psoriasis, and rheumatoid arthritis (RA)...
June 14, 2017: Journal of Autoimmunity
https://www.readbyqxmd.com/read/28624246/uv-c-irradiation-accelerates-neutral-lipid-synthesis-in-the-marine-oleaginous-diatom-fistulifera-solaris
#19
Atsushi Arakaki, Takuya Matsumoto, Takuma Tateishi, Mitsufumi Matsumoto, Daisuke Nojima, Yoshino Tomoko, Tsuyoshi Tanaka
This study investigated the induction of oil synthesis in the oleaginous diatom, Fistulifera solaris, following irradiation with small doses of UV-C. A rapid induction of oil accumulation was confirmed within 6h following UV-C radiation of the diatom cells, with increases in cell oil body volumes after 24h of approximately 4- to 6-fold from the initial volume. Reactive oxygen species (ROS), which can be generated by a UV-C-mediated reaction, were detected in irradiated cells and the correlation between ROS generation and oil accumulation was confirmed...
June 1, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28623234/a-ciliary-opsin-in-the-brain-of-a-marine-annelid-zooplankton-is-uv-sensitive-and-the-sensitivity-is-tuned-by-a-single-amino-acid-residue
#20
Hisao Tsukamoto, I-Shan Chen, Yoshihiro Kubo, Yuji Furutani
Ciliary opsins were classically thought to function only in vertebrates for vision, but they have been recently identified also in invertebrates for non-visual photoreception. Larvae of the annelid Platynereis dumerilii are used as a zooplankton model, and this zooplankton species possesses a "vertebrate-type" ciliary opsin (named c-opsin) in the brain. Platynereis c-opsin is suggested to relay light signals to melatonin production and circadian behaviors. Thus, the spectral and biochemical characteristics of this c-opsin would be directly related to non-visual photoreception in this zooplankton model...
June 16, 2017: Journal of Biological Chemistry
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