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https://www.readbyqxmd.com/read/28641196/c1-c2-alkyl-aminiums-in-urban-aerosols-insights-from-ambient-and-fuel-combustion-emission-measurements-in-the-yangtze-river-delta-region-of-china
#1
Wenchao Shen, Lili Ren, Yi Zhao, Luyu Zhou, Liang Dai, Xinlei Ge, Shaofei Kong, Qin Yan, Honghui Xu, Yujun Jiang, Jun He, Mindong Chen, Huan Yu
We measured low molar-mass alkyl aminiums (methylaminium, dimethylaminium, ethylaminium and diethylaminium) in urban aerosols in the Yangtze River Delta region of eastern China in August 2014 and from November 2015 to May 2016. After examining artifact formation on sample filters, methylaminium, dimethylaminium and ethylaminium concentrations were quantified. The three C1-C2 aminiums exhibited a unimodal size distribution that maximized between 0.56 and 1.0 μm. Their concentrations in PM2.5 were 5.7 ± 3...
June 19, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28641175/atmospheric-dust-deposition-on-soils-around-an-abandoned-fluorite-mine-hammam-zriba-ne-tunisia
#2
Chaima Djebbi, Fredj Chaabani, Oriol Font, Ignasi Queralt, Xavier Querol
The present study focuses on the eolian dispersion and dust deposition, of major and trace elements in soils in a semi-arid climate, around an old fluorite (CaF2) and barite (BaSO4) mine, located in Hammam Zriba in Northern Tunisia. Ore deposits from this site contain a high amount of metal sulphides constituting heavy metal pollution in the surrounding environment. Samples of waste from the surface of mine tailings and agricultural topsoil samples in the vicinity of the mine were collected. The soil samples and a control sample from unpolluted area, were taken in the direction of prevailing northwest and west winds...
June 19, 2017: Environmental Research
https://www.readbyqxmd.com/read/28640639/alkaline-earth-centered-co-homologation-reduction-and-amine-carbonylation
#3
Mathew D Anker, Christos E Kefalidis, Yan Yang, Jian Fang, Michael S Hill, Mary F Mahon, Laurent Maron
Reactions of -diketiminato magnesium and calcium hydrides with 1 atmosphere of CO result in a reductive coupling process to produce the corresponding derivatives of the cis-ethenediolate dianion. Computational (DFT) analysis of this processes mediated by Ca, Sr and Ba highlight a common mechanism and a facility for the reaction that increases with increasing alkaline earth (Ae) atomic weight. Reaction of CO with PhSiH3 in the presence of the magnesium or calcium hydrides results in catalytic reduction to methylsilane and methylene silylether products respectively...
June 22, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28640607/primary-and-photochemically-aged-aerosol-emissions-from-biomass-cookstoves-chemical-and-physical-characterization
#4
Stephen M Reece, Aditya Sinha, Andrew P Grieshop
Secondary organic aerosol (SOA) formation during photo-oxidation of primary emissions from cookstoves used in developing countries may make important contributions to their climate and air quality impacts. We present results from laboratory experiments with a field portable oxidation flow reactor (F-OFR) to study the evolution of emissions over hours to weeks of equivalent atmospheric aging. Lab tests, using dry red oak, measured fresh and aged emissions from a 3 stone fire (TSF), a "rocket" natural draft stove (NDS) and a forced draft gasifier stove (FDGS), in order of increasing modified combustion efficiency (MCE) and decreasing particulate matter emission factors (EF)...
June 22, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28640603/changes-in-light-absorptivity-of-molecular-weight-separated-brown-carbon-due-to-photolytic-aging
#5
Jenny Pui Shan Wong, Athanasios Nenes, Rodney J Weber
Brown carbon (BrC) are those organic compounds in atmospheric aerosols that absorb solar radiation and may play an important role on planetary radiative forcing and climate. However, little is known about the production and loss mechanisms of BrC in the atmosphere. Here, we study how the light absorptivity of BrC from wood smoke and secondary BrC generated from reaction of ammonium sulfate with methylglyoxal changes under photolytic aging by UVA radiation in the aqueous phase. Owing to its chemical complexity, BrC is separated by molecular weight using size exclusion chromatography and the response of each molecular weight fraction to aging is studied...
June 22, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28640598/structural-and-light-absorption-characteristics-of-complex-water-insoluble-organic-mixtures-in-urban-submicron-aerosols
#6
Qingcai Chen, Fumikazu Ikemori, Yuua Nakamura, Petr Vodicka, Kimitaka Kawamura, Michihiro Mochida
Submicrometer aerosols in the urban atmosphere of Nagoya, Japan, were collected in late winter and early spring, and the water-insoluble organic matter (WISOM) in the samples were fractionated into six subfractions based on their polarities by using solvent and normal-phase solid-phase extractions: non-polar (F1), low-polar (F2 and F3), and medium-polar (F4, F5, and F6) fractions. The overall structural characteristics of these subfractions were then analyzed using Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and high-resolution aerosol mass spectrometry...
June 22, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28637270/in-planta-recapitulation-of-isoprene-synthases-evolution-from-ocimene-synthases
#7
Mingai Li, Jia Xu, Alberto Algarra Alarcon, Silvia Carlin, Enrico Barbaro, Luca Cappellin, Violeta Velikova, Urska Vrhovsek, Francesco Loreto, Claudio Varotto
Isoprene is the most abundant biogenic volatile hydrocarbon compound naturally emitted by plants and plays a major role in atmospheric chemistry. It has been proposed that isoprene synthases (IspS) may readily evolve from other terpene synthases, but this hypothesis has not been experimentally investigated.We isolated and functionally validated in Arabidopsis the first isoprene synthase gene, AdoIspS, from a monocotyledonous species (Arundo donax L., Poaceae). Phylogenetic reconstruction indicates that AdoIspS and dicots isoprene synthases most likely originated by parallel evolution from TPS-b monoterpene synthases...
June 16, 2017: Molecular Biology and Evolution
https://www.readbyqxmd.com/read/28636976/improving-soil-nutrient-availability-increases-carbon-rhizodeposition-under-maize-and-soybean-in-mollisols
#8
Yunfa Qiao, Shujie Miao, Xiaozeng Han, Shuping Yue, Caixian Tang
Rhizodeposited carbon (C) is an important source of soil organic C, and plays an important role in the C cycle in the soil-plant-atmosphere continuum. However, interactive effects of plant species and soil nutrient availability on C rhizodeposition remain unclear. This experiment examined the effect of soil nutrient availability on C rhizodeposition of C4 maize and C3 soybean with contrasting photosynthetic capacity. The soils (Mollisols) were collected from three treatments of no fertilizer (Control), inorganic fertilizer only (NPK), and NPK plus organic manure (NPKM) in a 24-year fertilization field trial...
June 18, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28636438/oxidative-stress-mediated-by-nitrogen-at-elevated-pressure-inhibits-non-small-cell-lung-cancer-growth
#9
Stephen R Thom, Mark Ma, Veena M Bhopale, Cindy Zhou, Li Mao
Purpose/Aim: High pressures of gases such as nitrogen enhance production of singlet oxygen. Therefore, we hypothesized that growth of non-small cell lung cancer (NSCLC) A549 cells and a human-derived NSCLC explant could be inhibited by an oxidative stress mechanism using high-pressure nitrogen. MATERIALS AND METHODS: Growth of human NSCLC explants and A549 cells in Matrigel were assessed after implantation into nude mice who were exposed to elevated pressures. RESULTS: Subcutaneous implant growth of NSCLC in nude mice was inhibited by a daily 78-minute protocol using nitrogen/oxygen breathing mixture such that at the maximum pressure of 2...
June 21, 2017: Experimental Lung Research
https://www.readbyqxmd.com/read/28636383/gene-expression-profiling-in-human-lung-cells-exposed-to-isoprene-derived-secondary-organic-aerosol
#10
Ying-Hsuan Lin, Maiko Arashiro, Phillip W Clapp, Tianqu Cui, Kenneth G Sexton, William Vizuete, Avram Gold, Ilona Jaspers, Rebecca C Fry, Jason Douglas Surratt
Secondary organic aerosol (SOA) derived from the photochemical oxidation of isoprene contributes a substantial mass fraction to atmospheric fine particulate matter (PM2.5). The formation of isoprene SOA is influenced largely by anthropogenic emissions through multiphase chemistry of its multi-generational oxidation products. Considering the abundance of isoprene SOA in the troposphere, understanding mechanisms of adverse health effects through inhalation exposure is critical to mitigating its potential impact on public health...
June 21, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28636366/oxygenation-via-c-h-c-c-bond-activation-with-molecular-oxygen
#11
Yu-Feng Liang, Ning Jiao
The selective oxidation of organic molecules is a fundamentally important component of modern synthetic chemistry. In the past decades, direct oxidative C-H and C-C bond functionalization has proved to be one of the most efficient and straightforward methods to synthesize complex products from simple and readily available starting materials. Among these oxidative processes, the use of molecular oxygen as a green and sustainable oxidant has attracted considerable attention because of its highly atom-economical, abundant, and environmentally friendly characteristics...
June 21, 2017: Accounts of Chemical Research
https://www.readbyqxmd.com/read/28636316/a-novel-melamine-o-phthalaldehyde-covalent-organic-frameworks-nanaosheets-enhancement-flame-retardant-and-mechanical-performances-of-thermoplastic-polyurethanes
#12
Xiaowei Mu, Jing Zhan, Xiaming Feng, Bihe Yuan, Shuilai Qiu, Lei Song, Yuan Hu
Covalent organic frameworks (COFs) nanosheets prepared from condensation reaction between melamine and o-phthalaldehyde are firstly prepared through ball milling and then incorporated into thermoplastic polyurethanes (TPU) by solution mixing. Transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectrometer are applied to characterize COFs nanosheets. It is observed apparently from TEM image that COFs nanosheets are obtained...
June 21, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28636035/development-of-air-stable-hydrogen-evolution-catalysts
#13
Biswajit Mondal, Abhishek Dey
Obtaining abundant pure hydrogen by reduction of water has an important implication in the development of clean and renewable energy. Hence research focused on the development of non-noble metal based facile and energy efficient catalysts for proton reduction is on the rise. However, for practical utilization, it is necessary that these complexes function unabated in the presence of atmospheric oxygen and other common contaminants in abundant water sources. There has been very little activity towards the development of oxygen-tolerant hydrogen producing catalysts...
June 21, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28635552/temporal-variation-of-fine-and-coarse-particulate-matter-sources-in-jeddah-saudi-arabia
#14
Chris C Lim, George D Thurston, Magdy Shamy, Mansour Alghamdi, Mamdouh Khoder, Abdullah M Mohorjy, Abdulrahman K Alkhalaf, Jason Brocato, Lung Chi Chen, Max Costa
This study provides the first comprehensive analysis of the seasonal variations and weekday/weekend differences in fine (PM2.5) and coarse (PM2.5-10) particulate matter mass concentrations, elemental constituents, and potential source origins in Jeddah, Saudi Arabia. Air quality samples were collected over one year, from June 2011 to May 2012 at a frequency of three times per week, and analyzed. The average mass concentrations of PM2.5 (21.9 μg/m(3)) and PM10 (107.8 μg/m(3)) during the sampling period exceeded the recommended annual average levels by the World Health Organization (WHO) for PM2...
June 21, 2017: Journal of the Air & Waste Management Association
https://www.readbyqxmd.com/read/28635281/reactions-of-criegee-intermediates-with-alcohols-at-air-aqueous-interfaces
#15
Shinichi Enami, Agustin J Colussi
The fate of Criegee intermediates (CIs) from the gas-phase ozonolysis of unsaturated organic compounds in the troposphere is largely controlled by their reactions with water vapor. We recently found that against all expectations carboxylic acids compete at millimolar concentrations with water for CIs at the air-liquid interface of aqueous organic media. This outcome is consistent with both the low water concentration in the outermost interfacial layers and the enrichment of the competing acids therein. Here we show, via on-line electrospray mass spectrometric detection, that CIs generated in situ in the fast ozonolysis of sesquiterpenes (C15H24) on the surface of water:acetonitrile microjets react with n ≥ 4 linear alcohols CnH2n+1OH to produce high molecular weight Cn+15 ethers in one-step...
June 21, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28635192/incidence-of-primary-spontaneous-pneumothorax-is-not-associated-with-microclimatic-variations-results-of-a-seven-year-survey-in-a-temperate-climate-area
#16
Ivan Comelli, Alessandra Bologna, Andrea Ticinesi, Andrea Magnacavallo, Denis Comelli, Tiziana Meschi, Gianfranco Cervellin
Some diseases, such as renal colic and atrial fibrillation, display an association with microclimatic variations. In particular, despite a correlation has been reported between incidence of primary spontaneous pneumothorax (PSP) and meteorological variations, the evidence remains poor and conflictual. The aim of this study was to assess the influence of day-by-day meteorological variations on the number of visits for PSP in the Emergency Department (ED). All PSP cases were retrieved from the hospital database from January 2008 to December 2014...
May 18, 2017: Monaldi Archives for Chest Disease, Archivio Monaldi Per le Malattie del Torace
https://www.readbyqxmd.com/read/28634410/climate-response-to-the-8-2-ka-event-in-coastal-california
#17
Jessica L Oster, Warren D Sharp, Aaron K Covey, Jansen Gibson, Bruce Rogers, Hari Mix
A fast-growing stalagmite from the central California coast provides a high-resolution record of climatic changes synchronous with global perturbations resulting from the catastrophic drainage of proglacial Lake Agassiz at ca. 8.2 ka. High frequency, large amplitude variations in carbon isotopes during the 8.2 ka event, coupled with pulsed increases in phosphorus concentrations, indicate more frequent or intense winter storms on the California coast. Decreased magnesium-calcium ratios point toward a sustained increase in effective moisture during the event, however the magnitude of change in Mg/Ca suggests this event was not as pronounced on the western North American coast as anomalies seen in the high northern latitudes and monsoon-influenced areas...
June 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28634331/genotoxicity-and-cytotoxicity-of-the-plasma-jet-treated-medium-on-lymphoblastoid-wil2-ns-cell-line-using-the-cytokinesis-block-micronucleus-cytome-assay
#18
Sung-Ha Hong, Endre J Szili, Michael Fenech, Nishtha Gaur, Robert D Short
Despite growing interest in the application of atmospheric plasma jets as medical treatment strategies, there has been comparatively little research on the potential genotoxic and cytotoxic effects of plasma jet treatment. In this study, we have employed the cytokinesis block micronucleus cytome (CBMN-Cyt) assay with WIL2-NS B lymphoblastoid cells to test the potential genotoxicity, as well as the cytotoxicity, of toxic species generated in cell culture media by an argon (Ar) plasma jet. Elevated levels of cell death (necrosis) and occurrence of chromosomal damage (micronuclei MN, nculeoplasmic bridge NPBs and nuclear bus, Nbuds) were observed when cells were exposed to plasma jet-treated media...
June 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28633835/influence-of-increase-in-static-pressure-on-bulk-nanobubbles
#19
Toru Tuziuti, Kyuichi Yasui, Wataru Kanematsu
The concentration and size distribution of bulk nanobubbles (ultrafine bubbles) of air in liquid was measured before and after increasing the static pressure. It was found that, after pressurization, the number concentration decreased and the size increased. The effect of pressurization is to compress the bubbles and decrease the distance between solids on the bubble surface, which act as nucleation sites for bubble growth and coalescence when the static pressure is returned to atmospheric pressure.
September 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28633812/sonochemical-synthesis-of-a-new-cobalt-ii-complex-crystal-structure-thermal-behavior-hirshfeld-surface-analysis-and-its-usage-as-precursor-for-preparation-of-coo-co3o4-nanoparticles
#20
Morteza Montazerozohori, Ardavan Masoudiasl, Sara Farokhiyani, Shiva Joohari, Patrick McArdle
A bidentate Schiff base ligand and its nano-structured cobalt(II) complex were synthesized under ultrasound irradiation and then their structures were identified by physical and spectral techniques SEM and XRD techniques were used to confirm the nanostructure character of the complex. Single crystal X-ray diffraction analysis showed that the complex crystallizes in the triclinic system with space group of P1¯ and two crystallographically independent molecules participate in its asymmetric unit. In the structure of complex, cobalt center is four-coordinated by two iminic nitrogens of bidentate Schiff base ligand and two bromide anions in a distorted tetrahedral geometry...
September 2017: Ultrasonics Sonochemistry
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