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https://www.readbyqxmd.com/read/28545217/a-miniature-bird-borne-passive-air-sampler-for-monitoring-halogenated-flame-retardants
#1
Manon Sorais, Ali Rezaei, Joseph O Okeme, Miriam L Diamond, Ricardo Izquierdo, Jean-François Giroux, Jonathan Verreault
Birds have been used intensively as biomonitors of halogenated flame retardants (HFRs), and several studies have reported elevated tissue concentrations and inter-individual variability for these contaminants. While diet is known to be an important exposure pathway for HFRs in birds, it has been suggested that exposure through air may represent an underestimated source of HFRs for certain species. However, a method was not available for measuring the atmospheric exposure of individual birds to HFRs or other semi-volatile contaminants...
May 21, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28545205/organic-composition-and-multiphase-stable-isotope-analysis-of-active-degrading-and-restored-blanket-bog
#2
Laura McAnallen, Rory Doherty, Neil Ogle
Here we used organic composition and stable isotopic analysis to evaluate the effects of drainage and restoration at an ombrotrophic peatland, to assess whether rewetting of blanket bogs will reverse degradation. The organic composition of the peat and the isotopic fractionation between the solid (peat), liquid (pore water) and gas (soil gas) phases on actively accumulating, degrading and restored locations are compared. Fourier Transform Infrared Spectroscopy (FTIR) analysis of the organic material has shown a high level of humification (low decomposition) in the active peat...
May 20, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28545105/research-on-calibrating-rock-mechanical-parameters-with-a-statistical-method
#3
Zhen Liu, Ye Guo, Shuheng Du, Gengyu Wu, Mao Pan
Research on the modeling of rock mechanics parameters is of great significance to the exploration of oil and gas. The use of logging data with the Kriging interpolation to study rock mechanics parameters has been proven to be effective in reservoir prediction and other oilfield applications and can provide additional data. However, there will sometimes be a great deviation due to the limited samples and the strong heterogeneity of a layer. To solve this problem, a new approach was proposed to calibrate rock mechanical models through the statistical analysis of logging data...
2017: PloS One
https://www.readbyqxmd.com/read/28545045/differences-in-speb-protease-activity-among-group-a-streptococci-associated-with-superficial-invasive-and-autoimmune-disease
#4
Anhphan T Ly, John P Noto, Odaelys L Walwyn, Robert R Tanz, Stanford T Shulman, William Kabat, Debra E Bessen
The secreted cysteine proteinase SpeB is an important virulence factor of group A streptococci (GAS), whereby SpeB activity varies widely among strains. To establish the degree to which SpeB activity correlates with disease, GAS organisms were recovered from patients with pharyngitis, impetigo, invasive disease or acute rheumatic fever (ARF), and selected for analysis using rigorous sampling criteria; >300 GAS isolates were tested for SpeB activity by casein digestion assays, and each GAS isolate was scored as a SpeB-producer or non-producer...
2017: PloS One
https://www.readbyqxmd.com/read/28544980/what-we-authors-reviewers-and-editors-of-scientific-work-can-learn-from-the-analytical-history-of-biological-3-nitrotyrosine
#5
REVIEW
Dimitrios Tsikas
Tyrosine and tyrosine residues in proteins are attacked by the reactive oxygen and nitrogen species peroxynitrite (O=N-OO(-)) to generate 3-nitrotyrosine (3-NT) and 3-nitrotyrosine-proteins (3-NTProt), respectively. 3-NT and 3-NTProt are widely accepted as biomarkers of nitr(os)ative stress. Over the years many different analytical methods have been reported for 3-NT and 3-NTProt. Reported concentrations often differ by more than three orders of magnitude, indicative of serious analytical problems. Strategies to overcome pre-analytical and analytical shortcomings and pitfalls have been proposed...
May 13, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28544927/estuarine-sediment-resuspension-and-acidification-release-behaviour-of-contaminants-under-different-oxidation-levels-and-acid-sources
#6
M Camino Martín-Torre, Eva Cifrian, Gema Ruiz, Berta Galán, Javier R Viguri
Carbon dioxide (CO2) Capture and Storage (CCS) is a technology to reduce the emissions of this gas to the atmosphere by sequestering it in geological formations. In the case of offshore storage, unexpected CO2 leakages will acidify the marine environment. Reductions of the pH might be also caused by anthropogenic activities or natural events such as acid spills and dredging operations or storms and floods. Changes in the pH of the marine environment will trigger the mobilisation of elements trapped in contaminated shallow sediments with unclear redox boundary...
May 22, 2017: Journal of Environmental Management
https://www.readbyqxmd.com/read/28544895/vibrational-spectroscopy-of-the-mass-selected-tetrahydrofurfuryl-alcohol-monomers-and-its-dimers-in-gas-phase-using-ir-depletion-and-vuv-single-photon-ionization
#7
Pengchao Wang, Yongjun Hu, Huaqi Zhan, Jiaxin Chen, Shan Jin, Wentao Song, Yujian Li
Tetrahydrofurfuryl alcohol (THFA, C5H10O2) is a close chemical analog of the sugar rings present in the phosphate-deoxyribose backbone structure of the nucleic acids. In present report, the infrared (IR) spectra of the size-selected THFA monomer and its dimer have been investigated in a pulsed supersonic jet using infrared-vacuum ultraviolet (VUV) ionization. Herein, the laser light at 118nm wavelength served as the source of "soft" ionization in a time-of-flight mass spectrometer. The IR features for the monomers located at 3622cm(-1) can be assigned to the intramolecular hydrogen bonding stretch vibrations mainly referring to A and C conformers...
May 1, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28544803/hollow-mesoporous-carbon-microparticles-and-micromotors-with-single-holes-templated-by-colloidal-silica-assisted-gas-bubbles
#8
Xiaoxi Huang, Tao Zhang, Tewodros Asefa
A simple, new synthetic method that produces hollow, mesoporous carbon microparticles, each with a single hole on its surface, is reported. The synthesis involves unique templates, which are composed of gaseous bubbles and colloidal silica, and poly(furfuryl alcohol) as a carbon precursor. The conditions that give these morphologically unique carbon microparticles are investigated, and the mechanisms that result in their unique structures are proposed. Notably, the amount of colloidal silica and the type of polymer are found to hugely dictate whether or not the synthesis results in hollow asymmetrical microparticles, each with a single hole...
May 19, 2017: Small
https://www.readbyqxmd.com/read/28544800/reinforced-microextraction-of-polycyclic-aromatic-hydrocarbons-from-polluted-soil-samples-using-an-in-needle-coated-fiber-with-polypyrrole-graphene-oxide-nanocomposite
#9
Mina Behfar, Ali Reza Ghiasvand, Fatemeh Yazdankhah
The surface of a stainless-steel wire was platinized using electrophoretic deposition method to create a high-surface-area, porous and cohesive substrate. The platinized fiber was coated by the polypyrrole/graphene oxide nanocomposite by electropolymerization and accommodated into a stainless-steel needle to fabricate an in-needle coated fiber. The developed setup was coupled to gas chromatography with flame ionization detection and applied to extract and determine polycyclic aromatic hydrocarbons (naphthalene, fluorene, phenanthrene, fluoranthene and pyrene) in complicated solid matrices, along with reinforcement of the extraction by cooling the sorbent, using liquid carbon dioxide...
May 25, 2017: Journal of Separation Science
https://www.readbyqxmd.com/read/28544649/activation-of-co2-by-vanadium-nitrogenase
#10
Nathaniel Sickerman, Yilin Hu, Markus Walter Ribbe
The reduction of CO2 into useful products, including hydrocarbon fuels, is an ongoing area of particular interest due to efforts to mitigate buildup of this greenhouse gas. While the industrial Fischer-Tropsch process can facilitate the hydrogenation of CO2 with H2 to form short-chain hydrocarbon products under high temperatures and pressures, a desire to perform these reactions under ambient conditions has inspired the use of biological approaches. Particularly, enzymes offer insight into how to activate and reduce CO2, but only one enzyme, nitrogenase, can perform the multielectron, multiproton reduction of CO¬2 into hydrocarbons...
May 22, 2017: Chemistry, An Asian Journal
https://www.readbyqxmd.com/read/28544571/reactivity-of-copper-iii-oxo-complexes-in-the-gas-phase
#11
Ghazaleh Yassaghi, Erik Andris, Jana Roithová
We show an efficient way to generate [(L)CuO]+ complexes with a number of monodentate and bidentate ligands L from their [(L)Cu(ClO3)]+ precursors by electrospray ionization. Further, we studied [(L)CuO]+ with L = 9,10-phenanthraquinone, 1,10-phenanthroline and acetonitrile in detail. The signature of these terminal copper-oxo complexes is elimination of the oxygen atom upon collisional activation. We have investigated and compared their reactions with water, ethane, ethylene and 1,4-cyclohexadiene. The [(CH3CN)CuO]+ complex can oxidize water and perform C-H activation and hydroxylation of ethane...
May 22, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/28544488/obstructive-sleep-apnea-in-down-syndrome-benefits-of-surgery-and-noninvasive-respiratory-support
#12
Benjamin Dudoignon, Alessandro Amaddeo, Annick Frapin, Briac Thierry, Livio de Sanctis, Jorge Olmo Arroyo, Sonia Khirani, Brigitte Fauroux
Children with Down syndrome are at increased risk of obstructive sleep apnea (OSA). The aim of the study was to describe the management of OSA in a large cohort of children with Down syndrome. A retrospective analysis of sleep studies and consequent management was performed for all consecutive Down syndrome patients evaluated between September 2013 and April 2016. The data of 57 patients were analyzed: 51/53 had an interpretable overnight polygraphy and 4 the recording of nocturnal gas exchange. Mean age at baseline sleep study was 6...
May 24, 2017: American Journal of Medical Genetics. Part A
https://www.readbyqxmd.com/read/28544371/high-loading-crystals-of-tetraaryladamantanes-and-the-uptake-and-release-of-aromatic-hydrocarbons-from-the-gas-phase
#13
Clemens Richert, Pierre-Emmanuel Alexandre, Alexander Schwenger, Wolfgang Frey
Recently, a tetraphenyladamantane octamethylether was shown to encapsulate a wide range of small molecules in its crystals. Uptake and release from the liquid phase were demonstrated, and crystalline inclusion complexes were prepared that act as formulation for obnoxious reagents. Less than two equivalents of guest molecules were found in the crystal structures, though. Here we report the synthesis of 1,3,5,7-tetrakis(2,4-diethoxyphenyl)-adamantane (TEO) and twelve X-ray crystal structures that contain up to 3...
May 23, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28544127/control-of-product-distribution-and-mechanism-by-ligation-and-electric-field-in-the-thermal-activation-of-methane
#14
Lei Yue, Jilai Li, Shaodong Zhou, Xiaoyan Sun, Maria Schlangen, Sason Shaik, Helmut Schwarz
Selective oxidative coupling of methane using metal-oxide-based catalysts constitutes one of the central challenges in the valorization of this inert hydrocarbon. Ligands have been known for decades to profoundly affect the electronic character of metal centers with the benefit to fine-tune the chemical features of, for example, cationic metal oxides. A well-studied case concerns the axial-ligand effect exerted in iron-oxo complexes, wherein by changing the electronic structure, the axial ligand fine-tunes the reactivity...
May 24, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28544043/identification-of-v-type-nerve-agents-in-vapor-samples-using-a-field-portable-capillary-gas-chromatography-membrane-interfaced-electron-ionization-quadrupole-mass-spectrometry-instrument-with-tri-bed-concentrator-and-fluoridating-conversion-tube
#15
Yasuhiko Ohrui, Tomoki Nagoya, Naoko Kurimata, Manabu Sodeyama, Yasuo Seto
A field-portable gas chromatography-mass spectrometry (GC-MS) system (Hapsite ER) was evaluated for the detection of nonvolatile V-type nerve agents (VX and Russian VX (RVX)) in the vapor phase. The Hapsite ER system consists of a Tri-Bed concentrator gas sampler, a nonpolar low thermal-mass capillary gas chromatography column and a hydrophobic membrane-interfaced electron ionization quadrupole mass spectrometer evacuated by a non-evaporative getter pump. The GC-MS system was attached to a VX-G fluoridating conversion tube containing silver nitrate and potassium fluoride...
May 25, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28543518/green-discolouration-of-urine-following-propofol-infusion-in-a-dog
#16
D Flaherty, A Auckburally
A three-year-old, female neutered Weimaraner was presented with a history of neck pain and tetraparesis. MRI revealed an extradural mass at the level of C3 vertebra, which was thought to be a spinal abscess, and the dog was scheduled for surgical exploration the following morning. Overnight the dog developed an exaggerated ventilatory pattern, with paradoxical inward movement of the thorax on inspiration. Arterial blood gas analysis revealed respiratory acidosis and ventilator support was initiated to prevent excessive respiratory fatigue...
May 25, 2017: Journal of Small Animal Practice
https://www.readbyqxmd.com/read/28543309/adenovirus-vector-expressing-keratinocyte-growth-factor-using-cag-promoter-impaired-pulmonary-function-of-elastase-induced-emphysema
#17
Hiroshi Oki, Takuya Yazawa, Yasuko Baba, Yumi Kanegae, Hanako Sato, Seiko Sakamoto, Takahisa Goto, Izumu Saito, Kiyoyasu Kurahashi
Pulmonary emphysema impairs quality of life and increases mortality. Previous studies demonstrated that administration of KGF before elastase instillation prevented pulmonary emphysema in mice. We hypothesized that KGF could improve pulmonary function, and that the therapeutic administration of KGF would restore damaged lungs caused by elastase instillation in an animal model. We constructed KGF expressing adenovirus vector, which prevented bleomycin induced pulmonary fibrosis in the previous study. Adenovirus vector (1...
May 24, 2017: Microbiology and Immunology
https://www.readbyqxmd.com/read/28543285/changes-in-monosaccharides-organic-acids-and-amino-acids-during-cabernet-sauvignon-wine-aging-based-on-a-simultaneous-analysis-using-gas-chromatography-mass-spectrometry
#18
Xin-Ke Zhang, Yi-Bin Lan, Bao-Qing Zhu, Xiao-Feng Xiang, Chang-Qing Duan, Ying Shi
BACKGROUND: Monosaccharides, organic acids and amino acids are the important flavor-related components in wines. The aim of this article is to develop and validate a method that could simultaneously analyze these compounds in wine based on silylation derivatization and gas chromatography-mass spectrometry (GC-MS), and apply this method on the investigation of the changes of these compounds and speculate their related influences on Cabernet Sauvignon wine flavor during wine aging. This work presented a new approach for wine analysis and provided more information concerning red wine aging...
May 25, 2017: Journal of the Science of Food and Agriculture
https://www.readbyqxmd.com/read/28543090/association-of-pulse-pressure-with-left-ventricular-geometry-and-function-in-elderly-nonhypertensive-patients-with-diabetes-a-3d-speckle-tracking-echocardiography-study
#19
Qingqing Wang, Kaibin Tan, Hongmei Xia, Yunhua Gao
PURPOSE: The aims of this study were to investigate and compare the left ventricular (LV) geometry and function in elderly nonhypertensive type 2 diabetic patients with normal (NPP, <60 mm Hg) and with high (HPP, ≥60 mmHg) 24-hour pulse pressure, and to explore the independent predictors of LV strain values in these patients. METHODS: A total of 76 elderly nonhypertensive type 2 diabetic patients with normal (≥55%) LV ejection fraction (LVEF) were included, 36 of whom had HPP...
May 22, 2017: Journal of Clinical Ultrasound: JCU
https://www.readbyqxmd.com/read/28542645/co2-insufflation-versus-air-insufflation-for-endoscopic-submucosal-dissection-a-meta-analysis-of-randomized-controlled-trials
#20
Xuan Li, Hao Dong, Yifeng Zhang, Guoxin Zhang
BACKGROUND: Carbon dioxide (CO2) insufflation is increasingly used for endoscopic submucosal dissection (ESD) owing to the faster absorption of CO2 as compared to that of air. Studies comparing CO2 insufflation and air insufflation have reported conflicting results. OBJECTIVES: This meta-analysis is aimed to assess the efficacy and safety of use of CO2 insufflation for ESD. METHODS: Clinical trials of CO2 insufflation versus air insufflation for ESD were searched in PubMed, Embase, the Cochrane Library and Chinese Biomedical Literature Database...
2017: PloS One
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