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https://www.readbyqxmd.com/read/27915227/prenatal-and-postnatal-polybrominated-diphenyl-ether-exposure-and-visual-spatial-abilities-in-children
#1
Ann M Vuong, Joseph M Braun, Kimberly Yolton, Changchun Xie, Glenys M Webster, Andreas Sjödin, Kim N Dietrich, Bruce P Lanphear, Aimin Chen
Polybrominated diphenyl ethers (PBDEs) are associated with impaired visual spatial abilities in toxicological studies, but no epidemiologic study has investigated PBDEs and visual spatial abilities in children. The Health Outcomes and Measures of the Environment Study, a prospective birth cohort (2003-2006, Cincinnati, OH), was used to examine prenatal and childhood PBDEs and visual spatial abilities in 199 children. PBDEs were measured at 16±3 weeks gestation and at 1, 2, 3, 5, and 8 years using gas chromatography/isotope dilution high-resolution mass spectrometry...
December 1, 2016: Environmental Research
https://www.readbyqxmd.com/read/27915188/combined-cluster-and-discriminant-analysis-an-efficient-chemometric-approach-in-diesel-fuel-characterization
#2
Márton Novák, Dóra Palya, Zsolt Bodai, Zoltán Nyiri, Norbert Magyar, József Kovács, Zsuzsanna Eke
Combined cluster and discriminant analysis (CCDA) as a chemometric tool in compound specific isotope analysis of diesel fuels was studied. The stable carbon isotope ratios (δ(13)C) of n-alkanes in diesel fuel can be used to characterize or differentiate diesels originating from different sources. We investigated 25 diesel fuel samples representing 20 different brands. The samples were collected from 25 different service stations in 11 European countries over a 2 year period. The n-alkane fraction of diesel fuels was separated using solid-state urea clathrate formation combined with silica gel fractionation...
November 23, 2016: Forensic Science International
https://www.readbyqxmd.com/read/27915170/optimization-of-substituted-imidazobenzodiazepines-as-novel-asthma-treatments
#3
Rajwana Jahan, Michael Rajesh Stephen, Gloria S Forkuo, Revathi Kodali, Margaret L Guthrie, Amanda N Nieman, Nina Y Yuan, Nicolas M Zahn, Michael M Poe, Guanguan Li, Olivia B Yu, Gene T Yocum, Charles W Emala, Douglas C Stafford, James M Cook, Leggy A Arnold
We describe the synthesis of analogs of XHE-III-74, a selective α4β3γ2 GABAAR ligand, shown to relax airway smooth muscle ex vivo and reduce airway hyperresponsiveness in a murine asthma model. To improve properties of this compound as an asthma therapeutic, a series of analogs with a deuterated methoxy group in place of methoxy group at C-8 position was evaluated for isotope effects in preclinical assays; including microsomal stability, cytotoxicity, and sensorimotor impairment. The deuterated compounds were equally or more metabolically stable than the corresponding non-deuterated analogs and increased sensorimotor impairment was observed for some deuterated compounds...
November 24, 2016: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/27915112/a-wavelet-filtering-method-for-cumulative-gamma-spectroscopy-used-in-wear-measurements
#4
Davide Bianchi, Claudia Lenauer, Gerhard Betz, András Vernes
Continuous ultra-mild wear quantification using radioactive isotopes involves measuring very low amounts of activity in limited time intervals. This results in gamma spectra with poor signal-to-noise ratio and hence very scattered wear data, especially during running-in, where wear is intrinsically low. Therefore, advanced filtering methods reducing the wear data scattering and making the calculation of the main peak area more accurate are mandatory. An energy-time dependent threshold for wavelet detail coefficients based on Poisson statistics and using a combined Barwell law for the estimation of the average photon counting rate is then introduced...
November 26, 2016: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/27914737/targeted-proteomics-of-cannabinoid-receptor-cb1-and-the-cb1b-isoform
#5
Soumita Ghosh, Isabel González-Mariscal, Josephine M Egan, Ruin Moaddel
Cannabinoid receptors (CBR), including CB1 and CB2 have been therapeutic targets for a number of conditions. Recently, splice variants of the CB1R have been identified in humans. The isoforms differ in their N-terminus sequence and pharmacological activity relative to the CB1R, as a result, the differentiation between the CB1 receptor and its isoform is required. As a result, a selected reaction monitoring mass spectrometry (SRM-MS) method was developed for the quantitation of CB1 and the CB1b isoform in CHO cells transduced with CB1 and CB1b...
November 11, 2016: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/27914640/assessing-the-fugitive-emission-of-ch4-via-migration-along-fault-zones-comparing-potential-shale-gas-basins-to-non-shale-basins-in-the-uk
#6
I M Boothroyd, S Almond, F Worrall, R J Davies
This study considered whether faults bounding hydrocarbon-bearing basins could be conduits for methane release to the atmosphere. Five basin bounding faults in the UK were considered: two which bounded potential shale gas basins; two faults that bounded coal basins; and one that bounded a basin with no known hydrocarbon deposits. In each basin, two mobile methane surveys were conducted, one along the surface expression of the basin bounding fault and one along a line of similar length but not intersecting the fault...
September 24, 2016: Science of the Total Environment
https://www.readbyqxmd.com/read/27914280/trace-isotope-analysis-of-ricinus-communis-seed-core-for-provenance-determination-by-laser-ablation-icp-ms
#7
Christina K Bagas, Rachel L Scadding, Cameron J Scadding, R John Watling, Warren Roberts, Simon P B Ovenden
The castor bean plant, Ricinus communis, grows wild throughout many regions of Australia. The seeds of the plant contain the schedule 1 chemical agent ricin, a type II ribosomal inhibiting protein. Currently there are limited analytical techniques that can be applied in analysis of the seeds to establish attribution. In this study, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used for the analysis of seeds collected from 68 plants across 38 locations around Australia. Of the 92 elemental isotopes measured, fifteen ((24)Mg, (27)Al, (44)Ca, (53)Cr, (55)Mn, (57)Fe, (60)Ni, (65)Cu, (66)Zn, (75)As, (85)Rb, (88)Sr, (98)Mo, (138)Ba and (202)Hg) yielded data that were relevant to all collection sites...
November 25, 2016: Forensic Science International
https://www.readbyqxmd.com/read/27913891/biotransformation-of-2-4-dinitroanisole-by-a-fungal-penicillium-sp
#8
Hunter W Schroer, Kathryn L Langenfeld, Xueshu Li, Hans-Joachim Lehmler, Craig L Just
Insensitive munitions explosives are new formulations that are less prone to unintended detonation compared to traditional explosives. While these formulations have safety benefits, the individual constituents, such as 2,4-dinitroanisole (DNAN), have an unknown ecosystem fate with potentially toxic impacts to flora and fauna exposed to DNAN and/or its metabolites. Fungi may be useful in remediation and have been shown to degrade traditional nitroaromatic explosives, such as 2,4,6-trinitrotoluene and 2,4-dinitrotoluene, that are structurally similar to DNAN...
December 2, 2016: Biodegradation
https://www.readbyqxmd.com/read/27913865/nitrogen-dynamics-in-subtropical-fringe-and-basin-mangrove-forests-inferred-from-stable-isotopes
#9
Carla Roberta Gonçalves Reis, Gabriela Bielefeld Nardoto, André Luis Casarin Rochelle, Simone Aparecida Vieira, Rafael Silva Oliveira
Mangroves exhibit low species richness compared to other tropical forests, but great structural and functional diversity. Aiming to contribute to a better understanding of the functioning of mangrove forests, we investigated nitrogen (N) dynamics in two physiographic types of mangroves (fringe and basin forests) in southeastern Brazil. Because fringe forests are under great influence of tidal flushing we hypothesized that these forests would exhibit higher N cycling rates in sediment and higher N losses to the atmosphere compared to basin forests...
December 2, 2016: Oecologia
https://www.readbyqxmd.com/read/27913581/a-proteomic-approach-to-analyse-the-aspirin-mediated-lysine-acetylome
#10
Michael H Tatham, Christian Cole, Paul Scullion, Ross Wilkie, Nicholas J Westwood, Lesley A Stark, Ronald T Hay
Aspirin, or acetylsalicylic acid is widely used to control pain, inflammation and fever. Important to this function is its ability to irreversibly acetylate cyclooxygenases at active site serines. Aspirin has the potential to acetylate other amino-acid side-chains, leading to the possibility that aspirin-mediated lysine acetylation could explain some of its as-yet unexplained drug actions or side-effects. Using isotopically labeled aspirin-d3, in combination with acetylated lysine purification and LC-MS/MS, we identified over 12000 sites of lysine acetylation from cultured human cells...
December 2, 2016: Molecular & Cellular Proteomics: MCP
https://www.readbyqxmd.com/read/27913419/benzene-degradation-by-variovorax-sp-within-a-coal-tar-contaminated-groundwater-microbial-community
#11
Kevin M Posman, Christopher M DeRito, Eugene L Madsen
: Investigations of environmental microbial communities are crucial for the discovery of populations capable of degrading hazardous compounds and may lead to improved bioremediation strategies. The goal of this study was to identify microorganisms responsible for aerobic benzene degradation in coal-tar contaminated groundwater. Benzene degradation was monitored in laboratory incubations of well waters using gas chromatography mass spectrometry (GC/MS). Stable isotope probing (SIP) experiments using (13)C-benzene allowed us to obtain (13)C-labled community DNA; from this, 16S rRNA clone libraries identified γ- and β-Proteobacteria as the active benzene metabolizing microbial populations...
December 2, 2016: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/27913414/distinct-anaerobic-bacterial-consumers-of-cellobiose-derived-carbon-in-boreal-fens-differing-in-ch4-vs-co2-production-ratio
#12
Heli Juottonen, Alexander Eiler, Christina Biasi, Eeva-Stiina Tuittila, Kim Yrjälä, Hannu Fritze
: Northern peatlands in general have high methane (CH4) emissions, but individual peatlands show considerable variation as CH4 sources. Particularly in nutrient poor peatlands, CH4 production can be low and exceeded by carbon dioxide (CO2) production from unresolved anaerobic processes. To clarify the role anaerobic bacterial degraders play in this variation, we compared consumers of cellobiose-derived carbon in two fens differing in nutrient status and the ratio of CH4 and CO2 produced...
December 2, 2016: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/27913290/early-and-brain-region-specific-decrease-of-de-novo-cholesterol-biosynthesis-in-huntington-s-disease-a-cross-validation-study-in-q175-knock-in-mice
#13
Mahalakshmi Shankaran, Eleonora Di Paolo, Valerio Leoni, Claudio Caccia, Costanza Ferrari Bardile, Hussein Mohammed, Stefano Di Donato, Seung Kwak, Deanna Marchionini, Scott Turner, Elena Cattaneo, Marta Valenza
Cholesterol precursors and cholesterol levels are reduced in brain regions of Huntington's disease (HD) mice. Here we quantified the rate of in vivo de novo cholesterol biosynthesis in the HD brain. Samples from different brain regions and blood of the heterozygous knock-in mouse model carrying 175 CAG repeats (Q175) at different phenotypic stages were processed independently by two research units to quantify cholesterol synthesis rate by (2)H2O labeling and measure the concentrations of lathosterol, cholesterol and its brain-specific cholesterol catabolite 24-hydroxy-cholesterol (24OHC) by isotope dilution mass spectrometry...
November 29, 2016: Neurobiology of Disease
https://www.readbyqxmd.com/read/27911811/the-structure-of-the-catechin-binding-site-of-human-sulfotransferase-1a1
#14
Ian Cook, Ting Wang, Mark Girvin, Thomas S Leyh
We are just beginning to understand the allosteric regulation of the human cytosolic sulfotransferase (SULTs) family-13 disease-relevant enzymes that regulate the activities of hundreds, if not thousands, of signaling small molecules. SULT1A1, the predominant isoform in adult liver, harbors two noninteracting allosteric sites, each of which binds a different molecular family: the catechins (naturally occurring flavonols) and nonsteroidal antiinflammatory drugs (NSAIDs). Here, we present the structure of an SULT allosteric binding site-the catechin-binding site of SULT1A1 bound to epigallocatechin gallate (EGCG)...
November 23, 2016: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/27911799/mechanism-of-the-intrinsic-arginine-finger-in-heterotrimeric-g-proteins
#15
Daniel Mann, Christian Teuber, Stefan A Tennigkeit, Grit Schröter, Klaus Gerwert, Carsten Kötting
Heterotrimeric G proteins are crucial molecular switches that maintain a large number of physiological processes in cells. The signal is encoded into surface alterations of the Gα subunit that carries GTP in its active state and GDP in its inactive state. The ability of the Gα subunit to hydrolyze GTP is essential for signal termination. Regulator of G protein signaling (RGS) proteins accelerates this process. A key player in this catalyzed reaction is an arginine residue, Arg178 in Gαi1, which is already an intrinsic part of the catalytic center in Gα in contrast to small GTPases, at which the corresponding GTPase-activating protein (GAP) provides the arginine "finger...
November 28, 2016: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/27911783/deglacial-temperature-history-of-west-antarctica
#16
Kurt M Cuffey, Gary D Clow, Eric J Steig, Christo Buizert, T J Fudge, Michelle Koutnik, Edwin D Waddington, Richard B Alley, Jeffrey P Severinghaus
The most recent glacial to interglacial transition constitutes a remarkable natural experiment for learning how Earth's climate responds to various forcings, including a rise in atmospheric CO2 This transition has left a direct thermal remnant in the polar ice sheets, where the exceptional purity and continual accumulation of ice permit analyses not possible in other settings. For Antarctica, the deglacial warming has previously been constrained only by the water isotopic composition in ice cores, without an absolute thermometric assessment of the isotopes' sensitivity to temperature...
November 28, 2016: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/27911042/orderly-layered-zr-benzylphosphonate-nanohybrids-for-efficient-acid-base-mediated-bifunctional-cascade-catalysis
#17
Hu Li, Zhen Fang, Jian He, Song Yang
The development of functional metal-organic materials being robust and active for bifunctional/cascade catalysis is of great significance. Herein, a series of mesoporous and orderly layered nanohybrids were synthesized for the first time via simple and template-free assembly of ortho-, meta-, or para-xylylenediphosphonates (o-, p-, or m-PhP) with zirconium. It was found that m-PhPZr nanoparticles (20-50 nm) with mesopores centered at 7.9 nm and high Lewis acid/base site ratio (1:0.7) showed prominent performance under mild conditions (as low as 82 ºC) in transfer hydrogenation of carbonyl compounds including bio-aldehydes to alcohols with near quantative yields and little Zr leaching...
December 2, 2016: ChemSusChem
https://www.readbyqxmd.com/read/27910642/novel-xenon-calibration-scheme-for-two-photon-absorption-laser-induced-fluorescence-of-hydrogen
#18
Drew Elliott, Earl Scime, Zachary Short
Two photon absorption laser induced fluorescence (TALIF) measurements of neutral hydrogen and its isotopes are typically calibrated by performing TALIF measurements on krypton with the same diagnostic system and using the known ratio of the absorption cross sections [K. Niemi et al., J. Phys. D 34, 2330 (2001)]. Here we present the measurements of a new calibration method based on a ground state xenon scheme for which the fluorescent emission wavelength is nearly identical to that of hydrogen, thereby eliminating chromatic effects in the collection optics and simplifying detector calibration...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910632/recent-advances-and-results-from-the-solid-radiochemistry-nuclear-diagnostic-at-the-national-ignition-facility
#19
N Gharibyan, D A Shaughnessy, K J Moody, P M Grant, J D Despotopulos, S A Faye, D R Jedlovec, C B Yeamans
The solid debris collection capability at the National Ignition Facility has been expanded to include a third line-of-sight assembly. The solid radiochemistry nuclear diagnostic measurement of the ratio of gold isotopes is dependent on the efficient collection of neutron-activated hohlraum debris by passive metal disks. The collection of target debris at this new location is more reliable in comparison to the historic locations, and it appears to be independent of collector surface ablation.
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910554/a-libs-method-for-simultaneous-monitoring-of-the-impurities-and-the-hydrogenic-composition-present-in-the-wall-of-the-tj-ii-stellarator
#20
B López-Miranda, B Zurro, A Baciero, M Martínez
The study of plasma-wall interactions and impurity transport in the plasma fusion devices is critical for the development of future fusion reactors. An experiment to perform laser induced breakdown spectroscopy, using minor modifications of our existing laser blow-off impurity injection system, has been set up thus making both experiments compatible. The radiation produced by the laser pulse focused at the TJ-II wall evaporates a surface layer of deposited impurities and the subsequent radiation produced by the laser-produced plasma is collected by two separate lens and fiber combinations into two spectrometers...
November 2016: Review of Scientific Instruments
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