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Chemical evolution

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https://www.readbyqxmd.com/read/27921384/a-robust-molecular-catalyst-generated-in-situ-for-photo-and-electrochemical-water-oxidation
#1
Hussein A Younus, Nazir Ahmad, Adeel H Chughtai, Matthias Vandichel, Michael Busch, Kristof Van Hecke, Mekhman Yusubov, Shaoxian Song, Francis Verpoort
Water splitting is the key step towards artificial photosystems for solar energy conversion and storage in the form of chemical bonding. The oxidation of water is the bottle-neck of this process that hampers its practical utility and hence efficient, robust, and also easy to make catalytic systems based on cheap and earth abundant materials are of exceptional importance. Here, we present an in-situ generated cobalt catalyst [Co(II)(TCA)2(H2O)2] (TCA = 1-Mesityl-1,2,3-1H-triazole-4-carboxylate) efficiently conducting photochemical water oxidation at near-neutral conditions...
December 5, 2016: ChemSusChem
https://www.readbyqxmd.com/read/27920435/evolution-of-the-intrinsic-electronic-phase-separation-in-la0-6er0-1sr0-3mno3-perovskite
#2
Lili Chen, Jiyu Fan, Wei Tong, Dazhi Hu, Yanda Ji, Jindong Liu, Lei Zhang, Li Pi, Yuheng Zhang, Hao Yang
Magnetic and electronic transport properties of perovskite manganite La0.6Er0.1Sr0.3MnO3 have been thoroughly examined through the measurements of magnetization, electron paramagnetic resonance(EPR), and resistivity. It was found that the substitution of Er(3+) for La(3+) ions introduced the chemical disorder and additional strain in this sample. An extra resonance signal occurred in EPR spectra at high temperatures well above T C gives a strong evidence of electronic phase separation(EPS). The analysis of resistivity enable us to identify the polaronic transport mechanism in the paramagnetic region...
December 2016: Scientific Reports
https://www.readbyqxmd.com/read/27920387/adaptive-capabilities-and-fitness-consequences-associated-with-pollution-exposure-in-fish
#3
REVIEW
Patrick B Hamilton, Gregor Rolshausen, Tamsyn M Uren Webster, Charles R Tyler
Many fish populations are exposed to harmful levels of chemical pollution and selection pressures associated with these exposures have led to the evolution of tolerance. Our understanding of the physiological basis for these adaptations is limited, but they are likely to include processes involved with the absorption, distribution, metabolism and/or excretion of the target chemical. Other potential adaptive mechanisms include enhancements in antioxidant responses, an increased capacity for DNA and/or tissue repair and alterations to the life cycle of fish that enable earlier reproduction...
January 19, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/27920386/does-eutrophication-driven-evolution-change-aquatic-ecosystems
#4
REVIEW
Timothy J Alexander, Pascal Vonlanthen, Ole Seehausen
Eutrophication increases primary production and changes the relative abundance, taxonomic composition and spatial distribution of primary producers within an aquatic ecosystem. The changes in composition and location of resources alter the distribution and flow of energy and biomass throughout the food web. Changes in productivity also alter the physico-chemical environment, which has further effects on the biota. Such ecological changes influence the direction and strength of natural and sexual selection experienced by populations...
January 19, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/27919640/the-french-human-biomonitoring-program-first-lessons-from-the-perinatal-component-and-future-needs
#5
Clémentine Dereumeaux, Clémence Fillol, Marie-Aline Charles, Sébastien Denys
This paper presents a progress report of the French human biomonitoring (HBM) program established in 2010. This program has been designed to provide a national representative estimation of the French population's exposure to various environmental chemicals and to study the determinants of exposure. This program currently consists in two surveys: a perinatal component related to a selection of 4145 pregnant women who have been enrolled in the Elfe cohort (the French Longitudinal Study since Childhood) in 2011, and a general population survey related to adults aged 18-74 years and children as from 6 years (Esteban)...
November 17, 2016: International Journal of Hygiene and Environmental Health
https://www.readbyqxmd.com/read/27919163/isotopes-to-assess-sustainability-of-overexploited-groundwater-in-the-souss-massa-system-morocco
#6
Mohammed Hssaisoune, Lhoussaine Bouchaou, Baudelaire N'da, Mouna Malki, Houria Abahous, Alan E Fryar
Groundwater depletion and changes in isotopic and chemical contents constitute the main indicators of overexploitation, recharge, and flow paths in the Souss-Massa aquifer. These indicators highlight processes concerning sustainability of water resources in the aquifer (e.g. surface/groundwater interaction, recharge processes, and marine intrusion). The spatial variation of stable and radioactive isotopic contents indicates a mixing of modern and old water within the system. Recent recharge was observed mainly along the Souss River (the major surface-water drainage in the study area) and in the irrigated areas...
December 5, 2016: Isotopes in Environmental and Health Studies
https://www.readbyqxmd.com/read/27913828/engineering-and-evolution-of-saccharomyces-cerevisiae-to-produce-biofuels-and-chemicals
#7
Timothy L Turner, Heejin Kim, In Iok Kong, Jing-Jing Liu, Guo-Chang Zhang, Yong-Su Jin
To mitigate global climate change caused partly by the use of fossil fuels, the production of fuels and chemicals from renewable biomass has been attempted. The conversion of various sugars from renewable biomass into biofuels by engineered baker's yeast (Saccharomyces cerevisiae) is one major direction which has grown dramatically in recent years. As well as shifting away from fossil fuels, the production of commodity chemicals by engineered S. cerevisiae has also increased significantly. The traditional approaches of biochemical and metabolic engineering to develop economic bioconversion processes in laboratory and industrial settings have been accelerated by rapid advancements in the areas of yeast genomics, synthetic biology, and systems biology...
December 3, 2016: Advances in Biochemical Engineering/biotechnology
https://www.readbyqxmd.com/read/27912243/vomeronasal-receptors-in-vertebrates-and-the-evolution-of-pheromone-detection
#8
Liliana Silva, Agostinho Antunes
Pheromones were identified as chemical signals used for intraspecific communication in insects (e.g., sexual attraction) in the 1950s. However, only almost 40 years later the vomeronasal receptors type-1 (V1R) and type-2 (V2R) were identified, usually associated with the presence of a vomeronasal organ (VNO). VRs are widespread in amphibians, reptiles, and mammals, but birds lost the VNO. Similarly, fishes lack VRs and a VNO but can still detect pheromones, instead using the olfactory receptors related to class A and class C G protein-coupled receptors...
November 28, 2016: Annual Review of Animal Biosciences
https://www.readbyqxmd.com/read/27911792/transcriptomics-and-neuroanatomy-of-the-clonal-raider-ant-implicate-an-expanded-clade-of-odorant-receptors-in-chemical-communication
#9
Sean K McKenzie, Ingrid Fetter-Pruneda, Vanessa Ruta, Daniel J C Kronauer
A major aim of sociogenomic research is to uncover common principles in the molecular evolution of sociality. This endeavor has been hampered by the small number of specific genes currently known to function in social behavior. Here we provide several lines of evidence suggesting that ants have evolved a large and novel clade of odorant receptor (OR) genes to perceive hydrocarbon-based pheromones, arguably the most important signals in ant communication. This genomic expansion is also mirrored in the ant brain via a corresponding expansion of a specific cluster of glomeruli in the antennal lobe...
December 6, 2016: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/27911498/solvothermally-prepared-cu2o-electrocatalysts-for-co2-reduction-with-tunable-selectivity-by-the-introduction-of-p-block-elements
#10
Gastón O Larrazábal, Antonio J Martín, Frank Krumeich, Roland Hauert, Javier Pérez-Ramírez
The electroreduction of CO2 to fuels and chemicals is an attractive strategy for valorizing CO2 emissions. In this study, we show that a Cu2O electrocatalyst prepared by a simple and potentially scalable solvothermal route effectively targeted CO evolution at low to moderate overpotentials (CECO ca. 60% after 12 h at -0.6 V vs. RHE), and that the introduction of p-block elements (In, Sn, Ga, Al) into the catalyst can be employed to tune its selectivity. SEM, HRTEM, and voltammetric analyses revealed that the Cu2O catalyst undergoes extensive surface restructuring (favorable for CO evolution) under reaction conditions...
December 2, 2016: ChemSusChem
https://www.readbyqxmd.com/read/27911097/performance-of-an-anaerobic-membrane-bioreactor-in-which-granular-sludge-and-dynamic-filtration-are-integrated
#11
Jixiang Yang, Xin Ji, Lunhui Lu, Hua Ma, Youpeng Chen, Jinsong Guo, Fang Fang
To alleviate the fouling of a filter, simple substrates, dynamic filtration, and granular sludge were applied in an anaerobic membrane bioreactor (AnMBR). The results showed that under a transmembrane pressure < 20 kPa, the filter flux ranged between 15 and 20 l (m(-2) h)(-1) for a period of 30 days. The flux was higher than the typical flux of AnMBRs with conventional membranes and most current dynamic filters. In addition, the low cost of the filter avoided the need for a higher flux. Moreover, a stable granular sludge bed, which consumed all volatile fatty acids, was maintained...
December 2, 2016: Biofouling
https://www.readbyqxmd.com/read/27910987/on-the-formation-of-nitrogen-substituted-polycyclic-aromatic-hydrocarbons-npahs-in-circumstellar-and-interstellar-environments
#12
REVIEW
Dorian S N Parker, Ralf I Kaiser
The chemical evolution of extraterrestrial environments leads to the formation of polycyclic aromatic hydrocarbons (PAHs) via gas phase radical mediated aromatization reactions. We review that these de facto barrierless reactions are capable of forming prebiotic molecules such as nitrogen substituted PAHs (NPAHs), which represent the missing link between nitrogen bearing acyclic molecules and prebiotic nucleobases along with vitamins found in meteorites. Crucial routes leading to the incorporation of nitrogen atoms into the aromatic ring have been exposed...
December 2, 2016: Chemical Society Reviews
https://www.readbyqxmd.com/read/27910555/unraveling-wall-conditioning-effects-on-plasma-facing-components-in-nstx-u-with-the-materials-analysis-particle-probe-mapp
#13
F Bedoya, J P Allain, R Kaita, C H Skinner, L Buzi, B E Koel
A novel Plasma Facing Components (PFCs) diagnostic, the Materials Analysis Particle Probe (MAPP), has been recently commissioned in the National Spherical Torus Experiment Upgrade (NSTX-U). MAPP is currently monitoring the chemical evolution of the PFCs in the NSTX-U lower divertor at 107 cm from the tokamak axis on a day-to-day basis. In this work, we summarize the methodology that was adopted to obtain qualitative and quantitative descriptions of the samples chemistry. Using this methodology, we were able to describe all the features in all our spectra to within a standard deviation of ±0...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27908461/the-vato-project-an-original-methodology-to-study-the-transfer-of-tritium-as-ht-and-hto-in-grassland-ecosystem
#14
D Maro, F Vermorel, M Rozet, C Aulagnier, D Hébert, S Le Dizès, C Voiseux, L Solier, C Cossonnet, C Godinot, B Fiévet, P Laguionie, O Connan, O Cazimajou, M Morillon, M Lamotte
Tritium ((3)H) is mainly released into the environment by nuclear power plants, military nuclear facilities and nuclear reprocessing plants. The construction of new nuclear facilities in the world as well as the evolution of nuclear fuel management might lead to an increase of (3)H discharges from the nuclear industry. The VATO project was set up by IRSN (Institut de Radioprotection et de Sûreté Nucléaire) and EDF (Electricité de France) to reduce the uncertainties in the knowledge about transfers of (3)H from an atmospheric source (currently releasing HT and HTO) to a grassland ecosystem...
November 29, 2016: Journal of Environmental Radioactivity
https://www.readbyqxmd.com/read/27907822/a-comparison-study-the-different-impacts-of-sodium-hypochlorite-on-pvdf-and-psf-ultrafiltration-uf-membranes
#15
Yang Zhang, Jie Wang, Fei Gao, Yongsheng Chen, Hongwei Zhang
Chemical ageing of ultrafiltration membranes related to drinking water operation is not a new problem, but literature documenting sieving properties and fouling behaviors of aged membranes are scarce. This paper shows how the surface chemistry evolution of polysulfone (PSF) and polyvinylidene fluoride (PVDF) membranes can lead to the formation of distinct membrane properties when exposed to sodium hypochlorite solutions. The surface physicochemical evolutions of aged membranes are characterized based on chemical composition (ATR-FTIR and XPS), water contact angle analysis, and surface zeta potential test...
November 7, 2016: Water Research
https://www.readbyqxmd.com/read/27906966/archival-isolates-confirm-a-single-topotype-of-west-nile-virus-in-australia
#16
Bixing Huang, Natalie A Prow, Andrew F van den Hurk, Richard J N Allcock, Peter R Moore, Stephen L Doggett, David Warrilow
West Nile virus is globally wide-spread and causes significant disease in humans and animals. The evolution of West Nile virus Kunjin subtype in Australia (WNVKUN) was investigated using archival samples collected over a period of 50 years. Based on the pattern of fixed amino acid substitutions and time-stamped molecular clock analyses, a single long-term lineage (or topotype) was inferred. This implies that a bottleneck exists such that regional strains eventually die out and are replaced with strains from a single source...
December 2016: PLoS Neglected Tropical Diseases
https://www.readbyqxmd.com/read/27902924/simple-mechanisms-of-early-life-simulation-model-on-the-origin-of-semi-cells
#17
Adrian Klein, Martin Bock, Wolfgang Alt
The development of first cellular structures played an important role in the early evolution of life. Early evolution of life probably took place on a molecular level in a reactive environment. The iron-sulfur theory postulates the formation of cell-like structures on catalytic surfaces. Experiments show that H2S together with FeS and other metallic centers drive auto-catalytic surface reactions, in which organic molecules such as pyruvic and amino acids occur. It is questionable which mechanisms are needed to form cell-like structures under these conditions...
November 27, 2016: Bio Systems
https://www.readbyqxmd.com/read/27902757/evidence-of-facilitation-cascade-processes-as-drivers-of-successional-patterns-of-ecosystem-engineers-at-the-upper-altitudinal-limit-of-the-dry-puna
#18
Luca Malatesta, Federico Maria Tardella, Karina Piermarteri, Andrea Catorci
Facilitation processes constitute basic elements of vegetation dynamics in harsh systems. Recent studies in tropical alpine environments demonstrated how pioneer plant species defined as "ecosystem engineers" are capable of enhancing landscape-level richness by adding new species to the community through the modification of microhabitats, and also provided hints about the alternation of different ecosystem engineers over time. Nevertheless, most of the existing works analysed different ecosystem engineers separately, without considering the interaction of different ecosystem engineers...
2016: PloS One
https://www.readbyqxmd.com/read/27899717/optimization-of-waste-combinations-during-in-vessel-composting-of-agricultural-waste
#19
V Sudharsan Varma, Ajay S Kalamdhad, Bimlesh Kumar
In-vessel composting of agricultural waste is a well-described approach for stabilization of compost within a short time period. Although composting studies have shown the different combinations of waste materials for producing good quality compost, studies of the particular ratio of the waste materials in the mix are still limited. In the present study, composting was conducted with a combination of vegetable waste, cow dung, sawdust and dry leaves using a 550 L rotary drum composter. Application of a radial basis functional neural network was used to simulate the composting process...
November 28, 2016: Waste Management & Research
https://www.readbyqxmd.com/read/27895820/sleep-circadian-dysrhythmia-obesity-and-diabetes
#20
REVIEW
Gumpeny Ramachandra Sridhar, Narasimhadevara Santhi Nirmala Sanjana
Synchrony of biological processes with environmental cues developed over millennia to match growth, reproduction and senescence. This entails a complex interplay of genetic, metabolic, chemical, light, hormonal and hedonistic factors across life forms. Sleep is one of the most prominent rhythms where such a match is established. Over the past 100 years or so, it has been possible to disturb the synchrony between sleep-wake cycle and environmental cues. Development of electric lights, shift work and continual accessibility of the internet has disrupted this match...
November 15, 2016: World Journal of Diabetes
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