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https://www.readbyqxmd.com/read/28190686/role-of-snow-in-the-fate-of-gaseous-and-particulate-exhaust-pollutants-from-gasoline-powered-vehicles
#1
Yevgen Nazarenko, Sébastien Fournier, Uday Kurien, Rodrigo Benjamin Rangel-Alvarado, Oleg Nepotchatykh, Patrice Seers, Parisa A Ariya
Little is known about pollution in urban snow and how aerosol and gaseous air pollutants interact with the urban snowpack. Here we investigate interactions of exhaust pollution with snow at low ambient temperature using fresh snow in a temperature-controlled chamber. A gasoline-powered engine from a modern light duty vehicle generated the exhaust and was operated in homogeneous and stratified engine regimes. We determined that, within a timescale of 30 min, snow takes up from the exhaust a large mass of organic pollutants and aerosol particles, which were observed by electron microscopy, mass spectrometry and aerosol sizers...
February 9, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28181364/a-naphtho-fused-double-7-helicene-from-a-maleate-bridged-chrysene-trimer
#2
Marli Ferreira, Guillaume Naulet, Hugo Gallardo, Pierre Dechambenoit, Harald Bock, Fabien Durola
Perkin condensation of chrysenyl-6-acetic acid with chrysenylene-6,12-diglyoxylic acid followed by in situ esterification gives a bismaleate, whose conjugated stilbene moieties are efficiently shielded against intermolecular condensations and undergo iodine-catalyzed oxidative photocyclization in toluene without the need for high dilution. The concentration is limited by the low solubility of the flexible bismaleate at room temperature. The so-obtained double [7]helicene crystallizes in a nonchiral meso form...
February 9, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28148980/simultaneous-biodegradation-of-polyaromatic-hydrocarbons-by-a-stenotrophomonas-sp-characterization-of-nid-genes-and-effect-of-surfactants-on-degradation
#3
Smita Kumari, Raj Kumar Regar, Abhay Bajaj, Ratnasekhar Ch, Gubbala Naga Venkata Satyanarayana, Mohana Krishna Reddy Mudiam, Natesan Manickam
A polyaromatic hydrocarbon degrading bacterium was isolated from a petroleum contaminated site and designated as Stenotrophomonas sp. strain IITR87. It was found to utilize pyrene, phenanthrene and benzo(a)pyrene as sole carbon source, but not anthracene, chrysene and fluoranthene. Gas chromatography and mass spectroscopy analysis resulted in identification of pyrene metabolites namely monohydroxypyrene, 4-oxa-pyrene-5-one, dimethoxypyrene and monohydroxyphenanthrene. Southern hybridization using naphthalene dioxygenase gene (nidA) as probe against the DNA of strain IITR87 revealed the presence of nidA gene...
March 2017: Indian Journal of Microbiology
https://www.readbyqxmd.com/read/28119020/in-vitro-metabolism-of-benzo-a-pyrene-7-8-dihydrodiol-and-dibenzo-def-p-chrysene-11-12-diol-in-rodent-and-human-hepatic-microsomes
#4
Jordan N Smith, Denis Mehinagic, Subhasree Nag, Susan R Crowell, Richard A Corley
Polycyclic aromatic hydrocarbons (PAHs) are contaminants that are ubiquitously found in the environment, produced through combustion of organic matter or petrochemicals, and many of which are procarcinogens. The prototypic PAH, benzo[a]pyrene (B[a]P) and the highly carcinogenic dibenzo[def,p]chrysene (DBC) are metabolically activated by isoforms of the P450 enzyme superfamily producing benzo[a]pyrene-7,8-dihydrodiol (B[a]P diol), dibenzo[def,p]chrysene-11,12 diol (DBC diol). Each of these diols can be further metabolized by cytochrome P450 enzymes to highly reactive diol-epoxide metabolites that readily react with DNA or by phase II conjugation facilitating excretion...
January 21, 2017: Toxicology Letters
https://www.readbyqxmd.com/read/28117860/an-atom-and-pot-economical-consecutive-multi-step-reaction-approach-to-polycyclic-aromatic-hydrocarbons-pahs
#5
Chada Raji Reddy, Uredi Dilipkumar, Ravula Shravya
A novel one-pot benzannulation reaction has been developed for the synthesis of substituted polycyclic aromatic hydrocarbons (PAHs) from the direct coupling of propargylic aldehydes/alcohols with 1,1-diarylethanol through an atom-economical uninterrupted three/four-step reaction sequence under mild and metal-free reaction conditions. The strategy involves an acid-catalyzed dehydration and carbon-carbon bond formation followed by DBU-promoted cycloisomerization. Naphthalene and phenanthrene were obtained via mono-benzannulation, and chrysene, picene and benzopicene were obtained involving consecutive di-benzannulation reactions in good yields starting from easily accessible starting materials...
January 24, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28104439/up-regulation-of-cyp1a1-and-phase-ii-enzymes-by-5-ring-isomeric-polycyclic-aromatic-hydrocarbons-in-precision-cut-rat-hepatic-slices-importance-of-molecular-shape
#6
Daphnee Pushparajah, Dfv Lewis, Costas Ioannides
The objectives of the present study were two-fold: (a) to evaluate the role of molecular shape on the interaction of polycyclic aromatic hydrocarbons (PAHs) with the Ah receptor and CYP1A1 upregulation, and (b) to evaluate the potential of PAHs to induce epoxide hydrolase and glutathione S-transferase, two major enzymes involved in their metabolism. In order to achieve these objectives, precision-cut rat liver slices were incubated with a range of concentrations of seven 5-ring isomeric PAHs, namely benzo[c]chrysene, benzo[b]chrysene, benzo[g]chrysene, dibenzo[a,j]anthracene, dibenzo[a,c]anthracene, picene and pentacene, for 24h...
January 16, 2017: Toxicology in Vitro: An International Journal Published in Association with BIBRA
https://www.readbyqxmd.com/read/28100150/polycyclic-aromatic-hydrocarbon-levels-and-risk-assessment-for-food-from-service-facilities-in-korea
#7
Shin-Woong Park, Jun-Hyun Jeong, Jae-Young Her, Mina K Kim, Kwang-Geun Lee
In this study levels of benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene and indeno[1,2,3-c,d]pyrene in 412 food items collected from food service facilities in Korea were analyzed. The concentrations of the 8 polycyclic aromatic hydrocarbons (PAHs) ranged 0.13-0.48 μg/kg. The concentrations of benzo[a]pyrene in all food samples were <1 μg/kg, which is the lowest maximum limit in foods regulated by EU legislation. PAH contents were employed to conduct exposure and risk assessment...
January 19, 2017: Food Additives & Contaminants. Part B, Surveillance
https://www.readbyqxmd.com/read/28058760/fluorescence-based-logic-gate-for-sensing-of-ca-2-and-f-ions-using-pvp-crowned-chrysene-nanoparticles-in-aqueous-medium
#8
Prasad G Mahajan, G B Kolekar, Shivajirao R Patil
Polyvinyl pyrrolidone (PVP) crowned chrysene nanoparticles (CHYNPs) were prepared by using a reprecipitation method. Dynamic light scattering (DLS) and scanning electron microscope (SEM) studies indicate that the monodispersed spherical nanoparticles bear a negative charge on their surfaces. The bathochromic spectral shift in the UV-visible and fluorescence spectrum of CHYNPs from chrysene (CHY) in acetone solution supports the J- type aggregation of nanoparticles. The aggregation-induced enhanced emission of CHYNPs at 486 and 522 nm decreases by increasing the concentration of the Ca(2)(+) ion solution...
January 5, 2017: Luminescence: the Journal of Biological and Chemical Luminescence
https://www.readbyqxmd.com/read/27979277/optimization-and-validation-of-a-method-using-uhplc-fluorescence-for-the-analysis-of-polycyclic-aromatic-hydrocarbons-in-cold-pressed-vegetable-oils
#9
Simone Alves da Silva, Geni Rodrigues Sampaio, Elizabeth Aparecida Ferraz da Silva Torres
Among the different food categories, the oils and fats are important sources of exposure to polycyclic aromatic hydrocarbons (PAHs), a group of organic chemical contaminants. The use of a validated method is essential to obtain reliable analytical results since the legislation establishes maximum limits in different foods. The objective of this study was to optimize and validate a method for the quantification of four PAHs [benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(a)pyrene] in vegetable oils...
April 15, 2017: Food Chemistry
https://www.readbyqxmd.com/read/27865658/characterization-of-particulate-phase-polycyclic-aromatic-hydrocarbons-emitted-from-incense-burning-and-their-bioreactivity-in-raw264-7-macrophage
#10
Tzu-Ting Yang, Su-Chen Ho, Lu-Te Chuang, Hsiao-Chi Chuang, Ya-Ting Li, Jyun-Jie Wu
This study investigated the effects of particle-bound polycyclic aromatic hydrocarbons (PAHs) produced from burning three incense types on and their bioreactivity in the RAW 264.7 murine macrophage cell line. Gas chromatography/mass spectrometry was used to determine the levels of 16 identified PAHs. Macrophages were exposed to incense particle extracts at concentrations of 0, 3.125, 6.25, 12.5, 25, 50, and 100 μg/mL for 24 h. After exposure, cell viability and nitric oxide (NO) and inflammatory mediator [tumor necrosis factor (TNF)-α] production of the cells were examined...
January 2017: Environmental Pollution
https://www.readbyqxmd.com/read/27864777/bioaccumulation-and-cancer-risk-of-polycyclic-aromatic-hydrocarbons-in-leafy-vegetables-grown-in-soils-within-automobile-repair-complex-and-environ-in-uyo-nigeria
#11
Edu Inam, Felicia Ibanga, Joseph Essien
Using gas chromatography-mass spectrometry and an incremental lifetime cancer risks (ILCRs) assessment model, the bioaccumulation and cancer risk of 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs) in leafy vegetables (Vernonia amygdalina and Lasianthera africanum) grown in soils within an automobile repair complex environment in Uyo, Nigeria was studied. The total PAHs concentrations recorded for soils ranged from 0.02 to 1.77 mg/kg. The highest level of 1.77 mg/kg was recorded for soils from the main automobile repair complex (site 1)...
December 2016: Environmental Monitoring and Assessment
https://www.readbyqxmd.com/read/27859494/how-reliable-is-dft-in-predicting-relative-energies-of-polycyclic-aromatic-hydrocarbon-isomers-comparison-of-functionals-from-different-rungs-of-jacob-s-ladder
#12
Amir Karton
Density functional theory (DFT) is the only quantum-chemical avenue for calculating thermochemical/kinetic properties of large polycyclic aromatic hydrocarbons (PAHs) such as graphene nanoflakes. Using CCSD(T)/CBS PAH isomerization energies, we find that all generalized gradient approximation (GGA) and meta GGA DFT functionals have severe difficulties in describing isomerization energies in PAHs. The poor performance of these functionals is demonstrated by the following root-mean-square deviations (RMSDs) obtained for a database of C14 H10 and C18 H12 isomerization energies...
March 5, 2017: Journal of Computational Chemistry
https://www.readbyqxmd.com/read/27782400/regioselectivity-in-the-controversial-scholl-reaction-of-1-benzoylpyrene-formation-of-a-five-member-ring-is-not-unexpected
#13
Yaacov Netanel Oded, Sergey Pogodin, Israel Agranat
Intramolecular Scholl reaction of 1-benzoylpyrene (1) gave 8H-dibenzo[def,qr]chrysen-8-one (2) and 11H-indeno[2,1-a]pyren-11-one (3) in a 1:2 ratio. The structures of 2 and 3 were determined, using (1)H NMR, (13)C NMR, and IR spectroscopies. A DFT B3LYP/6-311G(d,p) study of the reaction's arenium-cation mechanism of (E)-1 and (Z)-1 giving 2 and 3, respectively, indicated the reaction's regioselectivity and kinetic control. The analogous reaction of 1-(1'-naphthoyl)pyrene gave exclusively 13H-benz[4,5]indeno[2,1-a]pyren-13-one...
November 18, 2016: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/27743326/characteristics-identification-and-potential-risk-of-polycyclic-aromatic-hydrocarbons-in-road-dusts-and-agricultural-soils-from-industrial-sites-in-shanghai-china
#14
Jinpu Jia, Chunjuan Bi, Xue Guo, Xueping Wang, Xiaoxiao Zhou, Zhenlou Chen
Road dusts and agricultural soil samples were collected from eight sites close to steel mills, chemical plants, and municipal solid waste incinerator in suburban Shanghai. Sixteen polycyclic aromatic hydrocarbons (PAHs) in the United States Environmental Protection Agency (US EPA) priority controlled list were analyzed quantitatively using GC-MS. The total PAH concentrations ranged from 0.79 to 6.2 μg g(-1) in road dust samples with a mean value of 2.38 μg g(-1) and 0.26 to 0.54 μg g(-1) in agricultural soils with an average of 0...
January 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/27722478/aluminium-mediated-aromatic-c-f-bond-activation-regioswitchable-construction-of-benzene-fused-triphenylene-frameworks
#15
Naoto Suzuki, Takeshi Fujita, Konstantin Yu Amsharov, Junji Ichikawa
Selective synthesis of benzo[f]tetraphenes or benzo[g]chrysenes was achieved via aromatic C-F bond cleavage and unprecedented regioselective C-C bond formation depending upon the choice of aluminium reagents. On treatment with AlCl3, 2-(biphenyl-2-yl)-1-fluoronaphthalenes afforded exclusively benzo[f]tetraphenes via C-C bond formation on the carbon atom γ to the original position of the fluorine substituent. In contrast, α-selective C-C bond formation was promoted by treatment with γ-Al2O3 to give benzo[g]chrysenes...
October 7, 2016: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/27717286/combination-of-liquid-chromatography-with-multivariate-curve-resolution-alternating-least-squares-mcr-als-in-the-quantitation-of-polycyclic-aromatic-hydrocarbons-present-in-paprika-samples
#16
Olga Monago-Maraña, Rocío L Pérez, Graciela M Escandar, Arsenio Muñoz de la Peña, Teresa Galeano-Díaz
This work presents a strategy for quantitating polycyclic aromatic hydrocarbons (PAHs) in smoked paprika samples. For this, a liquid chromatographic method with fluorimetric detection (HPLC-FLD) was optimized. To resolve some interference co-eluting with the target analytes, the second-order multivariate curve resolution-alternating least-squares (MCR-ALS) algorithm has been employed combined with this liquid chromatographic method. Among the eight PAHs quantified (fluorene, phenanthrene, anthracene, pyrene, chrysene, benzo[a]anthracene, benzo[b]fluoranthene, and benzo[a]pyrene) by HPLC-FLD, only in the case of fluorene, pyrene, and benzo[b]fluoranthene was it necessary to apply the second-order algorithm for their resolution...
November 2, 2016: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/27712071/tetraazacalix-2-arence-2-triazine-coated-fe3o4-sio2-magnetic-nanoparticles-for-simultaneous-dispersive-solid-phase-extraction-and-determination-of-trace-multi-target-analytes
#17
Wenfen Zhang, Yanhao Zhang, Qiong Jiang, Wenjie Zhao, Ajuan Yu, Hong Chang, Ximei Lu, Fuwei Xie, Baoxian Ye, Shusheng Zhang
To satisfy the requirement of simultaneous extraction and characterization of diverse kinds of multi-target analytes, the preparation, characterization and application of a novel tetraazacalix[2]arene[2]triazine (TCT) coated magnetic nanoparticular (TCT MNP) adsorbent are presented in this paper. TCT assembles two benzene rings and two triazines with nitrogen cross-bridging links, which exhibits a unique structural framework and versatile recognition features based on the multiple recognition sites. These include π electron stacking, charge transfer, hydrogen bonding and ion-exchange...
October 7, 2016: Analytical Chemistry
https://www.readbyqxmd.com/read/27710179/polycyclic-aromatic-hydrocarbons-in-commercial-brands-of-dry-whole-soybeans-for-direct-human-consumption
#18
Laura Pereira Garcia, Fernanda M L Gomes, Silvia Tfouni, Eduardo Vicente, Geovana D Savi, Karolina Santos, Vildes M Scussel
A total of 13 polycyclic aromatic hydrocarbons (PAHs) were surveyed in dry whole soybeans (Glycine max L.) sold for human consumption. The analysed samples were commercialised in vegetarian shops and food stores in Southern Brazil regions. The determination of PAHs levels was carried out by high performance liquid chromatography (HPLC)with fluorescence detection. PAHs were present in 89.7% of the samples. Chrysene (Chy) and 5 methyl chrysene (5MeChy) were the main PAHs detected (76.9% and 71.8%, respectively) followed by dibenzo(ai)pyrene (DaiP), however in a much less percentage of samples (23...
October 6, 2016: Food Additives & Contaminants. Part B, Surveillance
https://www.readbyqxmd.com/read/27679456/polycyclic-aromatic-hydrocarbons-pahs-around-tea-processing-industries-using-high-sulfur-coals
#19
Jyotilima Saikia, Puja Khare, Prasenjit Saikia, Binoy K Saikia
In the present investigation, the concentrations of polycyclic aromatic hydrocarbons (PAHs) associated with PM2.5, PM10 and dust particles emitted from two tea processing industrial units were studied that uses high-sulfur coal as their energy source. A total of 16 PAHs (viz. naphthalene (Nap), acenaphthene (Ace), acenaphthylene (Acen), phenanthrene (Phe), fluorene (Flu), anthracene (Ant), fluoranthene (Fluo), pyrene (Pyr), benz[a]anthracene (BaA), chrysene (Chry), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a]pyrene (BaP), dibenz[a,h]anthracene (DBahA), indeno[1,2,3-cd]pyrene (IP) and benzo[ghi]perylene (BghiP) were measured...
September 27, 2016: Environmental Geochemistry and Health
https://www.readbyqxmd.com/read/27627846/the-detoxification-responses-damage-effects-and-bioaccumulation-in-the-scallop-chlamys-farreri-exposed-to-single-and-mixtures-of-benzo-a-pyrene-and-chrysene
#20
Ruiming Guo, Luqing Pan, Pengfei Lin, Lei Zheng
This study aimed to investigate the detoxification responses, damage effects and biotransformation in scallop Chlamys farreri exposed to benzo[a]pyrene (BaP) (0.1, 1μg/L), chrysene (CHR) (0.1, 1μg/L) and BaP+CHR (0.1+0.1, 1+1μg/L) for 15days. Results demonstrated that BaP and CHR concentration (BaP<CHR) in tissues increased rapidly in a time and dose effect. The mRNA expression of aryl hydrocarbon receptor (AhR), cytochrome P450 1A1 (CYP1A1), CYP1B1, multidrug resistance protein 1 (MRP1/ABCC1), breast cancer resistance protein (BCRP/ABCG2) and P-glycoprotein (P-gp) were induced especially in the mixtures of BaP and CHR...
January 2017: Comparative Biochemistry and Physiology. Toxicology & Pharmacology: CBP
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