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https://www.readbyqxmd.com/read/29911712/light-mediated-iodoperfluoroalkylation-of-alkenes-alkynes-catalyzed-by-chloride-ions-role-of-halogen-bonding
#1
Redouane Beniazza, Lionel Remisse, Damien Jardel, Dominique Lastécouères, Jean-Marc Vincent
An innovative procedure for the iodoperfluoroalkylation of alkenes/alkynes is described. These reactions, including iodotrifluoromethylations of alkenes, proceed very efficiently under low intensity UVA irradiation in deoxygenated methanol solutions containing catalytic amounts of NaCl or Bu4NCl. Preliminary mechanistic studies indicate that the light-promoted homolytic cleavage of the Rf-I bond that initiates the reaction is facilitated by the halogen bonding interaction between RfI and chloride ions.
June 18, 2018: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/29907840/enhanced-near-surface-ozone-under-heatwave-conditions-in-a-mediterranean-island
#2
Andri Pyrgou, Panos Hadjinicolaou, Mat Santamouris
Near-surface ozone is enhanced under particular chemical reactions and physical processes. This study showed the seasonal variation of near-surface ozone in Nicosia, Cyprus and focused in summers when the highest ozone levels were noted using a seven year hourly dataset from 2007 to 2014. The originality of this study is that it examines how ozone levels changed under heatwave conditions (defined as 4 consecutive days with daily maximum temperature over 39 °C) with emphasis on specific air quality and meteorological parameters with respect to non-heatwave summer conditions...
June 15, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29904757/are-current-guidelines-for-sun-protection-optimal-for-health-exploring-the-evidence
#3
Robyn M Lucas, Rachel E Neale, Sasha Madronich, Richard L McKenzie
Exposure of the skin to ultraviolet (UV) radiation is the main risk factor for skin cancer, and a major source of vitamin D, in many regions of the world. Sun protection messages to minimize skin cancer risks but avoid vitamin D deficiency are challenging, partly because levels of UV radiation vary by location, season, time of day, and atmospheric conditions. The UV Index provides information on levels of UV radiation and is a cornerstone of sun protection guidelines. Current guidelines from the World Health Organization are that sun protection is required only when the UV Index is 3 or greater...
June 15, 2018: Photochemical & Photobiological Sciences
https://www.readbyqxmd.com/read/29904739/internal-dose-escalation-is-associated-with-increased-local-control-for-non-small-cell-lung-cancer-nsclc-brain-metastases-treated-with-stereotactic-radiosurgery-srs
#4
Christopher Abraham, Adam Garsa, Shahed N Badiyan, Robert Drzymala, Deshan Yang, Todd DeWees, Christina Tsien, Joshua L Dowling, Keith M Rich, Michael R Chicoine, Albert H Kim, Eric C Leuthardt, Cliff Robinson
Objective: To identify potentially actionable dosimetric predictors of local control (LC) for non-small cell lung cancer (NSCLC) brain metastases treated with single-fraction stereotactic radiosurgery (SRS). Methods and materials: Patients with NSCLC brain metastases treated with single-fraction SRS were identified. Eligible patients had at least 1 follow-up magnetic resonance imaging scan and were without prior metastasectomy or SRS to the same lesion. LC and overall survival (OS) were estimated using the Kaplan-Meier method...
April 2018: Advances in Radiation Oncology
https://www.readbyqxmd.com/read/29899534/ocean-acidification-conditions-increase-resilience-of-marine-diatoms
#5
Jacob J Valenzuela, Adrián López García de Lomana, Allison Lee, E V Armbrust, Mónica V Orellana, Nitin S Baliga
The fate of diatoms in future acidified oceans could have dramatic implications on marine ecosystems, because they account for ~40% of marine primary production. Here, we quantify resilience of Thalassiosira pseudonana in mid-20th century (300 ppm CO2 ) and future (1000 ppm CO2 ) conditions that cause ocean acidification, using a stress test that probes its ability to recover from incrementally higher amount of low-dose ultraviolet A (UVA) and B (UVB) radiation and re-initiate growth in day-night cycles, limited by nitrogen...
June 13, 2018: Nature Communications
https://www.readbyqxmd.com/read/29898357/particle-phase-photosensitized-radical-production-and-aerosol-aging
#6
Pablo Corral-Arroyo, Thorsten Bartels-Rausch, Peter Aaron Alpert, Stephane Dumas, Sebastien Perrier, Christian George, Markus Ammann
Atmospheric aerosol particles may contain light absorbing (brown carbon, BrC), triplet forming organic compounds that can sustain catalytic radical reactions and thus contribute to oxidative aerosol aging. We quantify UVA induced radical production initiated by imidazole-2-carboxaldehyde (IC), benzophenone (BPh) and 4-Benzoylbenzoic acid (BBA) in the presence of the non-absorbing organics citric acid (CA), shikimic acid (SA) and syringol (Syr) at varying mixing ratios. We observed a maximum HO2 release of 1013 molecules min-1 cm-2 at a mole ratio ΧBPh <0...
June 13, 2018: Environmental Science & Technology
https://www.readbyqxmd.com/read/29895115/-the-clinical-study-of-corneal-cross-linking-with-preserved-corneal-epithelial-flap-in-thin-keratoconic-corneas
#7
J J Sun, X J Huang, W Y Shi, T Wang
Objective: To evaluate the therapeutic effect of corneal collagen cross-linking (CXL) with preserved corneal epithelial flap and isotonic riboflavin for treatment of keratoconus eyes with thin corneas. Methods: Prospective case-control study. Twenty two eyes of 20 patients (16 males and 4 females, with age of 23.5±4.9), who have been diagnosed with progressive keratoeonus and the comeal stroma thickness of whom were less than 400μm (without the epithelium), were included in this study. Corneal collagen crosslinking was performed under preserved corneal epithelial flap (8...
June 11, 2018: [Zhonghua Yan Ke za Zhi] Chinese Journal of Ophthalmology
https://www.readbyqxmd.com/read/29893408/crocin-a-natural-molecule-with-potentially-beneficial-effects-against-skin-aging
#8
D Fagot, D M Pham, J Laboureau, E Planel, L Guerin, C Nègre, M Donovan, B A Bernard
OBJECTIVE: Oxidative stress and low grade chronic inflammation stand out as key features of physiological skin aging. The aim of this study was to examine in normal human epidermal keratinocytes (NHEK) and human dermal fibroblasts (HDF) grown in vitro, the antioxidant and anti-inflammatory properties of crocin, a carotenoid glycoside responsible for the color of saffron. Moreover, considering the newly emerging field of skin glycobiology and the presence of two gentiobiosyl moieties in crocin, the effect of crocin on NHEK glycosylation pathways was for the first time investigated...
June 12, 2018: International Journal of Cosmetic Science
https://www.readbyqxmd.com/read/29885761/erratum-to-the-uva-induced-long-non-coding-rna-gs1-600g8-5-regulates-the-expression-of-il-8-j-dermatol-sci-90-june-3-2018-363-366
#9
Kazuyuki Yo, Thomas M Rünger
No abstract text is available yet for this article.
June 6, 2018: Journal of Dermatological Science
https://www.readbyqxmd.com/read/29882991/potential-cutaneous-carcinogenic-risk-of-exposure-to-uv-nail-lamp-a-review
#10
REVIEW
Nahla Shihab, Henry W Lim
The increased use of ultraviolet (UV) nail lamps in recent years has generated safety concerns of this device. A UV nail lamp is a source of artificial UVA radiation, often used to dry, harden, and cure the nails at home and in the salon. UVA radiation is a known to be mutagenic and can cause damage to the DNA, resulting in cutaneous malignancy. Currently, there are only a few studies that have evaluated UV nail lamp irradiation and its potential carcinogenic risk. We review the literature on UV nail lamps, its safety, effect on nails and hands, and the potential role in increasing the risk of cutaneous malignancy...
June 8, 2018: Photodermatology, Photoimmunology & Photomedicine
https://www.readbyqxmd.com/read/29880745/keratinocyte-motility-is-affected-by-uva-radiation-a-comparison-between-normal-and-dysplastic-cells
#11
Cristina M Niculiţe, Marina T Nechifor, Andreea O Urs, Laura Olariu, Laura C Ceafalan, Mircea Leabu
UVA radiation induces multiple and complex changes in the skin, affecting epidermal cell behavior. This study reports the effects of UVA exposure on normal (HaCaT) and dysplastic (DOK) keratinocytes. The adherence, spreading and proliferation were investigated by time-lapse measurement of cell layer impedance on different matrix proteins. Prior to UVA exposure, the time required for adherence and spreading did not differ significantly for HaCaT and DOK cells, while spreading areas were larger for HaCaT cells...
June 7, 2018: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/29878376/evaluated-uva-irradiances-over-a-twelve-year-period-at-a-sub-tropical-site-from-ozone-monitoring-instrument-data-including-the-influence-of-cloud
#12
Mustapha A A Jebar, Alfio V Parisi, Nathan J Downs, Joanna F Turner
This research investigated the influence of cloud on the broadband UVA solar noon irradiances evaluated from the solar noon satellite based OMI spectral UV data that were compared to the irradiances of a ground-based radiometer from 1 October 2004 to 31 December 2016. The correlation between ground-based radiometer data and the evaluated OMI broadband UVA data evaluated with a model were dependent on whether or not the solar disc was obscured by the presence of cloud and the total sky cloud fraction. For conditions when the sun was not obscured by cloud, the evaluated satellite and the ground-based UVA irradiance correlation was best for cloud cover between 0-2 octa (R2 = 0...
June 7, 2018: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/29864725/ferulic-acid-photoprotective-properties-in-association-with-uv-filters-multifunctional-sunscreen-with-improved-spf-and-uva-pf
#13
Daniela D'Almeida Peres, Fernanda Daud Sarruf, Camila Areias de Oliveira, Maria Valéria Robles Velasco, André Rolim Baby
Ultraviolet (UV) radiation stimulates several injurious biological effects on cutaneous tissue, causing, for instance, photocarcinogenesis. Sunscreens are topical products designed to protect the skin against these harmful effects and their use must be encouraged. The addition of antioxidants, as ferulic acid (FA), a phenolic compound from the class of the hydroxycinnamic acids, in sunscreens could improve their sun protection factor (SPF) and prevent inflammatory reactions. Here, the clinical safety and efficacy of an association of ethylhexyl triazone and bis-ethylhexyloxyphenol methoxyphenyl triazine (UV filters) with ferulic acid were assessed...
May 26, 2018: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/29863843/mesoporous-silica-and-organosilica-nanomaterials-as-uv-blocking-agents
#14
Nikola Knezevic, Nebojsa Ilic, Veljko R Djokić, Rada Petrovic, Djordje Janackovic
Mesoporous silica nanoparticles (MSN) and periodic mesoporous organosilica nanoparticles containing bridging benzene (PMOBTB) and ethane (PMOBTE) moieties are synthesized, characterized and evaluated for application in skin protection from UVA/UVB sun irradiation. Furthermore, the influence of surface functionalization with chelating 3-(2-aminoethylamino)propylsilane and Zn2+ ions on the UV-blocking ability of MSN is evaluated, along with the photostability and capability of the synthesized nanomaterials to carry avobenzone, a known UV-absorbing agent...
June 4, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29850669/mechanistic-considerations-on-the-wavelength-dependent-variations-of-uvr-genotoxicity-and-mutagenesis-in-skin-the-discrimination-of-uva-signature-from-uv-signature-mutation
#15
Hironobu Ikehata
Ultraviolet radiation (UVR) predominantly induces UV-signature mutations, C → T and CC → TT base substitutions at dipyrimidine sites, in the cellular and skin genome. I observed in our in vivo mutation studies of mouse skin that these UVR-specific mutations show a wavelength-dependent variation in their sequence-context preference. The C → T mutation occurs most frequently in the 5'-TCG-3' sequence regardless of the UVR wavelength, but is recovered more preferentially there as the wavelength increases, resulting in prominent occurrences exclusively in the TCG sequence in the UVA wavelength range, which I will designate as a "UVA signature" in this review...
May 31, 2018: Photochemical & Photobiological Sciences
https://www.readbyqxmd.com/read/29848104/in-silico-assessment-of-literature-insulin-bolus-calculation-methods-accounting-for-glucose-rate-of-change
#16
Giacomo Cappon, Francesca Marturano, Martina Vettoretti, Andrea Facchinetti, Giovanni Sparacino
BACKGROUND: The standard formula (SF) used in bolus calculators (BCs) determines meal insulin bolus using "static" measurement of blood glucose concentration (BG) obtained by self-monitoring of blood glucose (SMBG) fingerprick device. Some methods have been proposed to improve efficacy of SF using "dynamic" information provided by continuous glucose monitoring (CGM), and, in particular, glucose rate of change (ROC). This article compares, in silico and in an ideal framework limiting the exposition to possibly confounding factors (such as CGM noise), the performance of three popular techniques devised for such a scope, that is, the methods of Buckingham et al (BU), Scheiner (SC), and Pettus and Edelman (PE)...
May 1, 2018: Journal of Diabetes Science and Technology
https://www.readbyqxmd.com/read/29807859/impact-of-an-ultraviolet-air-sterilizer-on-cardiac-surgery-patients-a-randomized-clinical-trial
#17
María Heredia-Rodríguez, Elisa Álvarez-Fuente, Juan Bustamante-Munguira, Rodrigo Poves-Alvarez, Inmaculada Fierro, Esther Gómez-Sánchez, Estefanía Gómez-Pesquera, Mario Lorenzo-López, José María Eiros, Francisco Javier Álvarez, Eduardo Tamayo
BACKGROUND: Numerous studies have evaluated the use of ultraviolet-C devices for terminal disinfection in hospitals, however, to date there is little information about the device's final impact on patients. We investigated the effect of an ultraviolet air sterilizer (UVAS) on the clinical outcomes of cardiac surgery patients. MATERIALS AND METHODS: This random, prospective and non-interventional study included 1097 adult patients undergoing elective cardiac surgery: 522 stayed in an ICU room with UVAS (Medixair® ) and 575 patients ICU room without UVAS and were used as a control...
May 25, 2018: Medicina Clínica
https://www.readbyqxmd.com/read/29803879/efficient-photocatalytic-oxidation-of-arsenite-from-contaminated-water-by-fe-2-o-3-mn-2-o-3-nanocomposite-under-uva-radiation-and-process-optimization-with-experimental-design
#18
Hadi Eslami, Mohammad Hassan Ehrampoush, Abbas Esmaeili, Ali Asghar Ebrahimi, Mohammad Hossein Salmani, Mohammad Taghi Ghaneian, Hossein Falahzadeh
The efficiency of photocatalytic oxidation process in arsenite (As(III)) removal from contaminated water by a new Fe2 O3 -Mn2 O3 nanocomposite under UVA radiation was investigated. The effect of nanocomposite dosage, pH and initial As(III) concentration on the photocatalytic oxidation of As(III) were studied by experimental design. The synthesized nanocomposite had a uniform and spherical morphological structure and contained 49.83% of Fe2 O3 and 29.36% of Mn2 O3 . Based on the experimental design model, in photocatalytic oxidation process, the effect of pH was higher than other parameters...
May 18, 2018: Chemosphere
https://www.readbyqxmd.com/read/29800836/impact-of-uva-pre-radiation-on-uvc-disinfection-performance-inactivation-repair-and-mechanism-study
#19
Y Xiao, X N Chu, M He, X C Liu, J Y Hu
Ultraviolet (UV) light emission diode (LED), which is mercury free and theoretically more energy efficient, has now become an alternative to conventional UV lamps in water disinfection industry. In this research, the disinfection performance of a novel sequential process, UVA365nm LED followed by UVC265nm LED (UVA-UVC), was evaluated. The results revealed that the responses of different bacterial strains to UVA-UVC varied. Coupled with appropriate dosages of UVC, a 20 min UVA pre-radiation provided higher inactivations (log inactivation) of E...
May 15, 2018: Water Research
https://www.readbyqxmd.com/read/29799473/antibacterial-hydrophilic-effect-and-mechanical-properties-of-orthodontic-resin-coated-with-uv-responsive-photocatalyst
#20
Akira Kuroiwa, Yoshiaki Nomura, Tsuyoshi Ochiai, Tomomi Sudo, Rie Nomoto, Tohru Hayakawa, Hiroyuki Kanzaki, Yoshiki Nakamura, Nobuhiro Hanada
Photocatalysts have multiple applications in air purifiers, paints, and self-cleaning coatings for medical devices such as catheters, as well as in the elimination of xenobiotics. In this study, a coating of a UV-responsive photocatalyst, titanium dioxide (TiO₂), was applied to an orthodontic resin. The antibacterial activity on oral bacteria as well as hydrophilic properties and mechanical properties of the TiO₂-coated resin were investigated. ultraviolet A (UVA) (352 nm) light was used as the light source...
May 25, 2018: Materials
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