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https://www.readbyqxmd.com/read/28723895/visible-light-driven-methane-formation-from-co2-with-a-molecular-iron-catalyst
#1
Heng Rao, Luciana C Schmidt, Julien Bonin, Marc Robert
Converting CO2 into fuel or chemical feedstock compounds could in principle reduce fossil fuel consumption and climate-changing CO2 emissions. One strategy aims for electrochemical conversions powered by electricity from renewable sources, but photochemical approaches driven by sunlight are also conceivable. A considerable challenge in both approaches is the development of efficient and selective catalysts, ideally based on cheap and Earth-abundant elements rather than expensive precious metals. Of the molecular photo- and electrocatalysts reported, only a few catalysts are stable and selective for CO2 reduction; moreover, these catalysts produce primarily CO or HCOOH, and catalysts capable of generating even low to moderate yields of highly reduced hydrocarbons remain rare...
July 17, 2017: Nature
https://www.readbyqxmd.com/read/28722632/pilot-intervention-study-of-household-ventilation-and-fine-particulate-matter-concentrations-in-a-low-income-urban-area-dhaka-bangladesh
#2
Anne M Weaver, Shahana Parveen, Doli Goswami, Christina Crabtree-Ide, Carole Rudra, Jihnhee Yu, Lina Mu, Alicia M Fry, Iffat Sharmin, Stephen P Luby, Pavani K Ram
Fine particulate matter (PM2.5) is a risk factor for pneumonia; ventilation may be protective. We tested behavioral and structural ventilation interventions on indoor PM2.5 in Dhaka, Bangladesh. We recruited 59 good ventilation (window or door in ≥ 3 walls) and 29 poor ventilation (no window, one door) homes. We monitored baseline indoor and outdoor PM2.5 for 48 hours. We asked all participants to increase ventilation behavior, including opening windows and doors, and operating fans. Where permitted, we installed windows in nine poor ventilation homes, then repeated PM2...
May 30, 2017: American Journal of Tropical Medicine and Hygiene
https://www.readbyqxmd.com/read/28722451/-basal-cell-carcinoma-and-the-modalities-of-its-therapy
#3
Petr Arenberger, Jiří Ettler
Basal cell carcinoma (BCC) also known as basalioma or basal cell cancer, is the most common skin cancer. BCC has a very low metastatic risk. This tumor can cause significant disfigurement by invading surrounding tissues. It occurs mainly in fair-skinned patients with a family history of this cancer. Sunlight is a factor in about two-thirds of these cancers. Standard surgical excision is the treatment of choice. Mohs micrographic surgery is an outpatient or inpatient procedure in which the tumor is surgically excised and then immediately examined under a microscope...
2017: Casopís Lékar̆ů C̆eských
https://www.readbyqxmd.com/read/28718467/how-to-make-an-efficient-and-robust-molecular-catalyst-for-water-oxidation
#4
Pablo Garrido-Barros, Carolina Gimbert-Suriñach, Roc Matheu, Xavier Sala, Antoni Llobet
Energy has been a central subject for human development from Homo erectus to date. The massive use of fossil fuels during the last 50 years has generated a large CO2 concentration in the atmosphere that has led to the so-called global warming. It is very urgent to come up with C-neutral energy schemes to be able to preserve Planet Earth for future generations to come and still preserve our modern societies' life style. One of the potential solutions is water splitting with sunlight (hν-WS) that is also associated with "artificial photosynthesis", since its working mode consists of light capture followed by water oxidation and proton reduction processes...
July 18, 2017: Chemical Society Reviews
https://www.readbyqxmd.com/read/28718028/predicting-attenuation-of-solar-radiation-uv-b-uv-a-and-par-in-waste-stabilization-ponds-under-sahelian-climatic-conditions
#5
Ynoussa Maiga, Joseph Wethé, Aboubakar Sidiki Ouattara, Alfred S Traoré
Because of its importance in pathogen removal and algal productivity in waste stabilization ponds, sunlight penetration was measured in microcosms and in situ under Sahelian climatic conditions. The different wavelengths were detected using a submersible radiometer equipped with three sensors: UV-B (311 nm), UV-A (369 nm) and photosynthetically available radiation (PAR, 400-700 nm). UV-B was more attenuated than UV-A and PAR. Facultative pond was more light-attenuating than maturation pond. The mean euphotic depths for UV-B were 0...
July 17, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28717014/investigating-mixotrophic-metabolism-in-the-model-diatom-phaeodactylum-tricornutum
#6
Valeria Villanova, Antonio Emidio Fortunato, Dipali Singh, Davide Dal Bo, Melissa Conte, Toshihiro Obata, Juliette Jouhet, Alisdair R Fernie, Eric Marechal, Angela Falciatore, Julien Pagliardini, Adeline Le Monnier, Mark Poolman, Gilles Curien, Dimitris Petroutsos, Giovanni Finazzi
Diatoms are prominent marine microalgae, interesting not only from an ecological point of view, but also for their possible use in biotechnology applications. They can be cultivated in phototrophic conditions, using sunlight as the sole energy source. Some diatoms, however, can also grow in a mixotrophic mode, wherein both light and external reduced carbon contribute to biomass accumulation. In this study, we investigated the consequences of mixotrophy on the growth and metabolism of the pennate diatom Phaeodactylum tricornutum, using glycerol as the source of reduced carbon...
September 5, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28716759/vitamin-d-levels-in-childhood-and-adolescence-and-cardiovascular-risk-factors-in-a-cohort-of-healthy-australian-children
#7
Larry Ke, Rebecca S Mason, Louise A Baur, Chris T Cowell, Xiaoying Liu, Sarah P Garnett, Kaye E Brock
As the prevalence of obesity appears to be increasing in Australia's youth the overall objective of this study was to examine serum 25-hydroxyvitamin D (25OHD) concentrations in a cohort of 8-year-olds (n=249) followed up at age 15 (n=162) and explore associations between 25OHD with cardiovascular disease (CVD) risk factors in these populations. This was done in two stages: the first, two cross-sectional analyses (at ages 8 and 15); and the second, a prospective analysis from age 8 to 15. At both ages data on 25OHD, blood lipids, and anthropometry were measured...
July 14, 2017: Journal of Steroid Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/28715582/iris-freckles-a-potential-biomarker-for-chronic-sun-damage
#8
Christoph Schwab, Christoph Mayer, Iris Zalaudek, Regina Riedl, Markus Richtig, Werner Wackernagel, Rainer Hofmann-Wellenhof, Georg Richtig, Gerald Langmann, Lisa Tarmann, Andreas Wedrich, Erika Richtig
Purpose: To investigate the role of sunlight exposure in iris freckles formation. Methods: We prospectively examined volunteers attending a skin cancer screening program conducted by ophthalmologists and dermatologists. Frequency and topographical variability of iris freckles were noted and associated with behavioral and dermatologic characteristics indicating high sun exposure. Results: Six hundred thirty-two participants (n = 360; 57% female) were examined...
May 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28715145/the-autophagy-receptor-adaptor-p62-is-up-regulated-by-uva-radiation-in-melanocytes-and-in-melanoma-cells
#9
Ashley Sample, Baozhong Zhao, Chunli Wu, Steven Qian, Xianglin Shi, Andrew Aplin, Yu-Ying He
UVA (315-400 nm) is the most abundant in sunlight and is used in indoor tanning beds. However, much remains to be understood about the regulation of the UVA damage response in melanocytes and melanoma. Here we show that UVA, but not the shorter waveband UVB (280-315 nm), up-regulates adaptor protein p62 in an Nrf2- and ROS-dependent manner, suggesting a UVA-specific effect on p62 regulation. UVA-induced p62 up-regulation was inhibited by a mitochondria-targeted antioxidant or Nrf2 knockdown. In addition, p62 knockdown inhibited UVA-induced ROS production and Nrf2 up-regulation...
July 17, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28713725/orange-and-sunlight-a-recipe-for-blisters
#10
Stephanie Au, Ali Yousif, Suresh Anandan
No abstract text is available yet for this article.
May 2017: World Journal of Plastic Surgery
https://www.readbyqxmd.com/read/28712879/comet-assay-on-thawed-embryos-an-optimized-technique-to-evaluate-dna-damage-in-mouse-embryos
#11
L Rolland, B Courbiere, V Tassistro, A Sansoni, T Orsière, W Liu, C Di Giorgio, J Perrin
Our objective was to optimize the CA technique on mammal embryos. MATERIALS AND METHODS: 1000 frozen 2-cell embryos from B6CBA mice were used. Based on a literature review, and after checking post-thaw embryo viability, the main outcome measures included: 1) comparison of the embryo recovery rate between 2 CA protocols (2 agarose layers and 3 agarose layers); 2) comparison of DNA damage by the CA on embryos with (ZP+) and without (ZP-) zona pellucida; and 3) comparison of DNA damage in embryos exposed to 2 genotoxic agents (H2O2 and simulated sunlight irradiation (SSI))...
July 13, 2017: Toxicology in Vitro: An International Journal Published in Association with BIBRA
https://www.readbyqxmd.com/read/28711840/a-promising-protected-ascorbic-acid-hydroxyapatite-nanocomposite-as-a-skin-anti-ager-a-detailed-photo-and-thermal-stability-study
#12
Mahmoud A Sliem, Rania A Karas, M A Harith
A new ascorbic acid (AA) nanocomposite with low toxicity and high photo and thermal stability is constructed for certain dermatological applications in humans. The presented nanocomposite consists of AA, nano-hydroxyapatite (nHAp) and carboxymethyl cellulose (CMC). The physicochemical properties of such CMC-nHAp-AA nanocomposite were characterized using X-Ray diffractometery (XRD), Fourier Transform Infra-Red (FTIR), Energy Dispersive X-ray (EDX) and UV-VIS spectroscopies. The size and morphology of the synthesized nanocomposites were characterized by TEM/SEM techniques...
July 8, 2017: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/28711348/impact-of-molecular-flexibility-on-the-site-energy-shift-of-chlorophylls-in-photosystem-ii
#13
Daniele Narzi, Emanuele Coccia, Marco Manzoli, Leonardo Guidoni
Light harvesting from the Sun by antenna complexes surrounding the reaction center of Photosystem II represents the first step of the natural oxygenic photosynthesis performed by plants, algae and cyanobacteria. The excitation energy derived from the sunlight is absorbed by the chlorophylls of the antenna and subsequently conveyed to the reaction center of Photosystem II through resonant energy transfer mechanisms. In the special pair of chlorophylls of the reaction center the charge separation occurs, eventually leading to the oxidation of water molecules into protons, electrons and molecular oxygen...
July 8, 2017: Biophysical Chemistry
https://www.readbyqxmd.com/read/28710358/latitudinal-cline-of-chronotype
#14
Mario André Leocadio-Miguel, Fernando Mazzili Louzada, Leandro Lourenção Duarte, Roberta Peixoto Areas, Marilene Alam, Marcelo Ventura Freire, John Fontenele-Araujo, Luiz Menna-Barreto, Mario Pedrazzoli
The rotation of the Earth around its own axis and around the sun determines the characteristics of the light/dark cycle, the most stable and ancient 24 h temporal cue for all organisms. Due to the tilt in the earth's axis in relation to the plane of the earth's orbit around the sun, sunlight reaches the Earth differentially depending on the latitude. The timing of circadian rhythms varies among individuals of a given population and biological and environmental factors underlie this variability. In the present study, we tested the hypothesis that latitude is associated to the regulation of circadian rhythm in humans...
July 14, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28706230/semiconductor-based-multilayer-selective-solar-absorber-for-unconcentrated-solar-thermal-energy-conversion
#15
Nathan H Thomas, Zhen Chen, Shanhui Fan, Austin J Minnich
Solar thermal energy conversion has attracted substantial renewed interest due to its applications in industrial heating, air conditioning, and electricity generation. Achieving stagnation temperatures exceeding 200 °C, pertinent to these technologies, with unconcentrated sunlight requires spectrally selective absorbers with exceptionally low emissivity in the thermal wavelength range and high visible absorptivity for the solar spectrum. In this Communication, we report a semiconductor-based multilayer selective absorber that exploits the sharp drop in optical absorption at the bandgap energy to achieve a measured absorptance of 76% at solar wavelengths and a low emittance of approximately 5% at thermal wavelengths...
July 13, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28704661/direct-and-indirect-photolysis-of-seven-micropollutants-in-secondary-effluent-from-a-wastewater-lagoon
#16
Yufei Wang, Felicity A Roddick, Linhua Fan
The photodegradation of seven micropollutants commonly found in municipal wastewater, namely caffeine, carbamazepine, diuron, simazine, sulfamethoxazole, triclosan and 2,4-D, was investigated in pure water and secondary effluent to understand the direct and indirect photolysis of these compounds under natural sunlight irradiation. Sulfamethoxazole and triclosan were readily photodegraded with half-lives of 5.8 and 1.8 h, respectively, whilst the others were relatively resistant towards sunlight irradiation...
June 29, 2017: Chemosphere
https://www.readbyqxmd.com/read/28703311/mechanisms-and-prevention-of-uv-induced-melanoma
#17
REVIEW
Ashley Sample, Yu-Ying He
Melanoma is the deadliest form of skin cancer and its incidence is rising, creating a costly and significant clinical problem. Exposure to ultraviolet (UV) radiation, namely UVA (315-400 nm) and UVB (280-315 nm), is a major risk factor for melanoma development. Cumulative UV radiation exposure from sunlight or tanning beds contributes to UV-induced DNA damage, oxidative stress, and inflammation in the skin. A number of factors, including hair color, skin type, genetic background, location, and history of tanning, determine the skin's response to UV radiation...
July 13, 2017: Photodermatology, Photoimmunology & Photomedicine
https://www.readbyqxmd.com/read/28702744/plant-extracts-and-natural-compounds-used-against-uvb-induced-photoaging
#18
REVIEW
Maria Cavinato, Birgit Waltenberger, Giorgia Baraldo, Carla V C Grade, Hermann Stuppner, Pidder Jansen-Dürr
Skin is continuously exposed to a variety of environmental stresses, including ultraviolet (UV) radiation. UVB is an inherent component of sunlight that crosses the epidermis and reaches the upper dermis, leading to increased oxidative stress, activation of inflammatory response and accumulation of DNA damage among other effects. The increase in UVB radiation on earth due to the destruction of stratospheric ozone poses a major environmental threat to the skin, increasing the risk of damage with long-term consequences, such as photoaging and photocarcinogenesis...
July 12, 2017: Biogerontology
https://www.readbyqxmd.com/read/28700216/accelerated-lifetime-testing-of-organic-inorganic-perovskite-solar-cells-encapsulated-by-low-cost-polyisobutylene
#19
Lei Shi, Trevor L Young, Jincheol Kim, Yun Sheng, Lei Wang, Yifeng Chen, Zhiqiang Feng, Mark Keevers, Xiaojing Hao, Pierre Verlinden, Martin A Green, Anita W Y Ho-Baillie
Metal halide perovskite solar cells (PSCs) have undergone rapid progress. However, unstable performance caused by sensitivity to environmental moisture and high temperature is a major impediment to commercialisation of PSCs. In the present work, a low temperature, glass-glass encapsulation technique using polyisobutylene (PIB) as the moisture barrier is investigated on planar glass/FTO/TiO2/FAPbI3/PTAA/gold perovskite solar cells. PIB was applied as either an edge seal or blanket layer. Electrical connections to the encapsulated PSCs were provided by either the FTO or Au layers...
July 12, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28697649/enhanced-photocatalytic-degradation-of-sulfamethoxazole-by-deposition-of-au-ag-and-cu-metallic-nanoparticles-on-tio2
#20
Rodolfo Zanella, Edwin Avella, Rosa María Ramírez Zamora, Felipe Castillón Barraza, Juan C Durán-Álvarez
Mono- (Au, Ag and Cu) and bi-metallic (Au-Ag and Au-Cu) nanoparticles were deposited on TiO2 and tested for the photocatalytic degradation of sulfamethoxazole using either UV-C or simulated sunlight. The optimal loading of metallic nanoparticles was determined as 1.5 wt. % for Au and Ag, and 1.0 wt. % for Cu. In the case of bi-metallic nanoparticles only the ratio 1:0.5 wt. % for both Au-Ag and Au-Cu was tested. In experiments using UV-C light, the highest degradation performance was found for Ag/TiO2, while bi-metallic nanoparticles supported on TiO2 also showed increased photocatalytic activity compared with unmodified TiO2...
July 12, 2017: Environmental Technology
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