Sediments from four inshore industrial sites and a reference site in the Great Lakes were extracted with solvents and characterized chemically for polycyclic aromatic compounds (PACs). An aqueous phase and a crude organic extract were obtained. The crude organic extract was further resolved into fractions A-2 (polycyclic aromatic hydrocarbons) and A-3 (nitrogen-containing polycyclic aromatic compounds), which were analyzed for PACs by gas chromatography and gas chromatography-mass spectrometry. The extracts and fractions were tested for mutagenicity in three assays: Ames, rat hepatocyte unscheduled DNA synthesis, and Chinese hamster ovary hypoxanthine-guanine phosphoribosyl transferase (CHO/HGPRT). Sediments from the industrial sites contained 27 to 363 μg/g total PACs; the reference site, less than 1 μg/g. Qualitative differences in the residue profiles among the sites were attributable to the probable sources of the PACs (petroleum versus combustion). Only one industrial site yielded measurable (0.1
TY - JOUR. T1 - The air pollutant 2-nitrofluorene as initiator and promoter in a liver model for chemical carcinogenesis. AU - Möller, L.. AU - Torndal, U. B.. AU - Eriksson, L. C.. AU - Gustafsson, J. Å. PY - 1989/3. Y1 - 1989/3. N2 - 2-Nitrofluorene (NF), a model substance for nitrated polycyclic aromatic hydrocarbons, is present in exhaust from diesel- and petrol-driven vehicles, in exhaust from kerosene heaters, and in urban air and river sediments. Therefore the possible consequences of human exposure are important to elucidate. In the present study the initiating and promoting activity of NF was studied in a liver model for chemical carcinogenesis in the rat. Furthermore, the in vivo metabolism and formation of genotoxic metabolites of NF were investigated. NF was found to be a moderate initiator and a weak promoter when compared to diethylnitrosamine (DEN) and 2-acetylamino-fluorene (AAF) respectively, both of which are potent carcinogens. Animals given NF excreted more urinary ...
TY - JOUR. T1 - Phosphorus-Containing Polycyclic Aromatic Hydrocarbons. AU - Szűcs, Rózsa. AU - Bouit, Pierre Antoine. AU - Nyulászi, L.. AU - Hissler, Muriel. PY - 2017/10/6. Y1 - 2017/10/6. N2 - Polycyclic aromatic hydrocarbons (PAHs) are highly appealing functional materials in the field of molecular electronics. In particular, molecular engineering of these derivatives by using organic chemistry is a powerful method to tune their properties from the point of view of the band gap and supramolecular assemblies. Another way to achieve such control is to take advantage of the specific reactivity of heteroatoms placed within the sp2-carbon framework. This strategy has been successfully applied to nitrogen, sulfur and boron. In this review, examples of phosphorus-containing PAHs and the effect of the phosphorus environment on the electronic properties from both experimental and theoretical points of view are discussed.. AB - Polycyclic aromatic hydrocarbons (PAHs) are highly appealing ...
Author: Panda, S. K. et al.; Genre: Journal Article; Published in Print: 2006; Keywords: beta-cyclodextrin stationary phase; FT-ICR-mass spectrometry; polycyclic aromatic sulfur heterocycles; fossil fuel; vacuum gas oil; Title: β-cyclodextrin as a stationary phase for the group separation of polycyclic aromatic compounds in normal-phase liquid chromatography
Polynuclear aromatic hydrocarbons (PAHs) are a class of contaminants commonly found in bottom sediments near highly industrialized areas. Resuspension of these sediments can make these contaminants more available for dispersal into the marine environment. The process will also cause the oxidation-reduction characteristics of the sediments to change from anaerobic to aerobic. Bacteria in these sediments have been shown capable of degrading 2 and 3 ring PAHs under aerobic conditions. This research examined the relationship between resuspension and biodegradation of PAHs in laboratory scale slurry reactors. Phenanthrene was used as the model compound. Radiolabeled compound was used to monitor mineralization, and mass balances were performed to determine final partitioning of carbon from degraded phenanthrene. Sediments were kept anaerobic from collection, through the contamination process, and through the loading of test reactors. Aeration of and contaminant release in sediment/water slurries was ...
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The fate of six polynuclear aromatic hydrocarbons during anaerobic digestion of municipal sludges was investigated in a two-stage pilot-scale digester system. Primary digester removal efficiencies ranged from 23% for acenaphthene to 62% for acenaphthylene; secondary digester removal efficiencies ranged from 22% for acenaphthylene to 42% for phenanthrene. Most of the remaining mass of candidate compounds was present in the secondary digester waste sludge stream. Less than 2.5% of the candidate compounds entering the digestion system was present in the secondary digester supernatant. A dynamic model of the primary digester incorporating mixed first-order biodegradation kinetics was calibrated for each of the candidate compounds. The biodegradation rate coefficients that were estimated for the primary digester ranged from 0.004 L/g·d for acenaphthene to 0.16 L/g·d for acenaphthylene. The biodegradation rate coefficient for acenaphthene did not significantly differ from zero ...
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TY - JOUR. T1 - Central role of radical cations in metabolic activation of polycyclic aromatic hydrocarbons. AU - Cavalieri, E. L.. AU - Rogan, E. G.. PY - 1995/1/1. Y1 - 1995/1/1. N2 - 1. Development of the chemistry of polycyclic aromatic hydrocarbon (PAH) radical cations has provided evidence that these intermediates play a major role in the metabolism of PAHs by P450 and in their binding to DNA. 2. Fluoro substitution of benzo[a]pyrene (BP) represents a suitable probe for studying mechanisms of oxygen transfer in the P450-catalysed formation of quinones and phenols from BP. Formation of BP-1,6-, -3,6- and -6,12-dione from the metabolism of 6-fluoroBP (6-FBP) is mediated by the intermediate 6-FBP+. Similarly, metabolism of 1-FBP and 3-FBP by rat liver microsomes produces BP-1,6-dione and BP-3,6-dione respectively. These results demonstrate that formation of quinones and phenols occurs via an initial electron transfer from BP to P450 and subsequent transfer of oxygen from the iron-oxo complex ...
TY - JOUR. T1 - The Characerization and Sources of Polycyclic Aromatic Hydrocarbons in PM10 in Rural, China. AU - Ye, Bixiong. AU - Krafft, Thomas. AU - Yang, Linsheng. AU - Li, Yonghua. AU - Li, Hairong. AU - Wang, Wuyi. AU - Pilot, Eva. PY - 2015. Y1 - 2015. N2 - Polycyclic aromatic hydrocarbon (PAH) samples in particles were collected with a PM10 sampler in rural areas of Beijing. PAH samples collected on quartz fiber filters were first extracted using dichloromethane with ultrasonic methods, and then were fractionated on an alumina-silica column. Finally, the aromatic and n-alkane fractions were analyzed by gas chromatography with mass spectrometry and gas chromatography- combustion-isotope ratio mass spectrometry. The level of PAHs showed distinctly seasonal changes throughout the year, with the highest concentrations in January and lowest concentration in July. Σ16PAH concentrations ranged from 153.23 to 867.41 ng·m-3 in January, from 21.53 to 527.42 ng·m-3 in April, from 1.84 to 32.02 ...
TY - JOUR. T1 - Orbital views of the electron transport through polycyclic aromatic hydrocarbons with different molecular sizes and edge type structures. AU - Li, Xinqian. AU - Staykov, Aleksandar Tsekov. AU - Yoshizawa, Kazunari. PY - 2010/6/3. Y1 - 2010/6/3. N2 - In this work electron-transport properties of π-conjugated polycyclic aromatic hydrocarbons with different molecular sizes and edge type structures are investigated. The applicability of a derived concept for orbital control of electron transport (J. Am. Chem. Soc. 2008, 130, 9406) is tested on larger hydrocarbons in order to estimate its predictive power for different types of compounds. Favorable connections for effective electron transport in π-conjugated systems with weak coupling between the molecules and electrodes are predicted on the basis of the orbital symmetry rule by looking at the phase and amplitude of the frontier orbitals. Qualitative predictions based on frontier orbital analysis are compared with density functional ...
Article Adsorption of polycyclic aromatic hydrocarbons from wastewater by using silica-based organic–inorganic nanohybrid material. Polycyclic aromatic hydrocarbons (PAHs) are a group of priority pollutants, which are classified as persistent ...
The fluorescence lifetimes of a number of aromatic hydrocarbons are shortened by 15-40% when the matrix is compressed by 30 kbar pressure. The causes of environmentally-induced lifetime shortening may be further illuminated by a detailed study of one solute under a variety of conditions. The document reports on such a study of pyrene and in addition, compares the pressure-enhanced electronic relaxation for the monomeric and excimeric forms of pyrene. The work established the magnitude of environmental influences on the singlet lifetime of pyrene and demonstrated a remarkable insensitivity of the emitting species to the nature of the microscopic surroundings, be it monomer or excimer.(*POLYCYCLIC COMPOUNDS
0048] The electron injection layer or electron transport layer may be formed using, for example, an electron accepting organic compound. Here, as the electron accepting organic compound, a known optional compound can be used without particular limitation. As such an organic compound, a polycyclic compound such as p-terphenyl or quaterphenyl, or a derivative thereof, a polycyclic hydrocarbon compound such as naphthalene, tetracene, pyrene, coronene, chrysene, anthracene, diphenylanthracene, naphthacene, or phenanthrene, or a derivative thereof, or a heterocyclic compound such as phenanthroline, bathophenanthroline, phenanthridine, acridine, quinoline, quinoxaline, or phenazine or a derivative thereof. In addition, fluoroceine, perylene, phthaloperylene, naphthaloperylene, perynone, phthaloperynone, naphthaloperynone, diphenylbutadiene, tetraphenylbutadiene, oxadiazole, aldazine, bisbenzoxazoline, bisstyryl, pyrazine, cyclopentadiene, oxine, aminoquinoline, imine, diphenylethylene, ...
Owing to the lack of detailed analysis in the C10+ fraction and scarcity of reliable thermodynamic properties on polycyclic compounds, it is usually not feasible to relate crude oil properties with the chemical structure of heavy fractions. Over the last decades, the description of C10-C36 fractions has mostly relied on average Cn properties determined from observations. We propose an alternative approach in two major steps. In the first step, we use Monte Carlo simulation methods to generate vapor-liquid equilibrium (VLE) data on representative hydrocarbons between C10 and C30, from ambient to near-critical temperature. Based on these results, standard liquid density and saturation pressure are correlated for naphthenic hydrocarbons (mono- and polycyclic), aromatic hydrocarbons (monocyclic, polycyclic, and naphthenoaromatic), and thiophenic compounds up to C36. In the second step, we apply the predicted properties on C10-C36 families to model nine real crude oils. The Cn fractions (n = 10-36) ...
An investigation for the analysis of polycyclic aromatic hydrocarbons in airborne particulates using thermal desorption and gas chromatography-mass spectrometry is described. Samples are obtained from ambient air using fibreglass filters and the volatile material from the filter is thermally desorbed to gas chromatograph. A 30 meter capillary column is used to separate the hydrocarbons and eight polyaromatic hydrocarbons are used to test the method and recovery is >95%. The eight polycyclic aromatic hydrocarbons anthracene, phenanthrene, fluoranthrene, pyrene, benzo (a) anthracene, chrysene, benzo (a) pyrene and benzo (e) pyrene were the most abundant PAHs found in the samples of ambient air with current method at Uxbridge-London. Application of the measurement of polycyclic aromatic hydrocarbons in ambient air samples shows that the hydrocarbons trapped in the particle phase to a lesser degree at higher ambient temperature. In conclusion a method has been developed to transfer the PAHs in ...
Worker exposures to 23 individual or groups of polyaromatic hydrocarbons (PAH) and azo heterocyclic compounds were determined at Chevron U.S.A. Inc. Refinery, El Segundo, California, on January 18 and 19, 1980. Area and personal samples were collected in the fluid catalytic cracker (FCC) and delayed coker units using a silver membrane filter followed by Chromosorb 102. Upwind samples at the refine
The rates of interactions of polycyclic aromatic hydrocarbons (PAHs) with biological cells studied with fluorescence appear to be different for cells from different origins. The monomer emission of benzo[,i,a,/i,]pyrene (BaP) is enhanced as in liposomes, but more significantly in normal liver cells than in liver cancer cells or kidney cells, and that enhancement is proportional to the amount of cells added. When PAHs are allowed to interact with cells for a certain period of time, metabolism appears to occur. The excimer emission is seen to dissipate continuously as reactions proceed, whereas the monomer emission increases, passes through a maximum, then starts to decrease when excimer emission becomes exhausted. The time plot of the BaP excimer emission in semilogarithmic coordinates indicates that the decrease or the mass transfer of microcrystalline BaP to the cell membrane is a first-order process. Metabolism has been investigated by monitoring the monomer emission. Liver cells have higher ...
The present invention relates to organic chemistry, in particular, to synthesis of sulfoderivatives of the polycyclic compounds and fabrication of optically anisotropic coatings on their base. The indanthrone sulfoderivatives of the general structural formulas I or II capable of forming LLC phase are disclosed. The disclosed compounds could be used, in particular, for producing optically isotropic or anisotropic and at least partially crystalline films. The application also includes the liquid crystal systems based on the disclosed compounds, and anisotropic films. wherein n is 3 or 4, R═CH3, C2H5, OCH3, OC2H5, Cl, Br, OH, NH2, z is the value selected from the list including 0, 1, 2, 3, and 4, M-counterion, and j-number of counterions in a dye molecule, and which can be fractional in case of one counterion belonging to several molecules, and in case n|1, counterions may be different.
A diverse set of 3-aminopyrazolo[3,4-d]pyrimidinones was designed and synthesized. The structure-activity relationships of these polycyclic compounds as phosphodiesterase 1 (PDE1) inhibitors were studied along with their physicochemical and pharmacokinetic properties. Systematic optimizations of this novel scaffold culminated in the identification of a clinical candidate, (6aR,9aS)-2-(4-(6-fluoropyridin-2-yl)benzyl)-5-methyl-3-(phenylamino)-5,6a,7,8,9,9a-hexahydrocyclopenta[4,5]imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4-(2H)-one phosphate (ITI-214), which exhibited picomolar inhibitory potency for PDE1, demonstrated excellent selectivity against all other PDE families and showed good efficacy in vivo. Currently, this investigational new drug is in Phase I clinical development and being considered for the treatment of several indications including cognitive deficits associated with schizophrenia and Alzheimers disease, movement disorders, attention deficit and hyperactivity disorders, and other central
TY - JOUR AU - Milić, Jelena AU - Avdalović, Jelena AU - Šolević Knudsen, Tatjana AU - Gojgić-Cvijović, Gordana AU - Jednak, Tanja AU - Vrvić, Miroslav PY - 2016 UR - http://cer.ihtm.bg.ac.rs/handle/123456789/1937 AB - The group of polycyclic aromatic hydrocarbons (PAHs) are very hazardous environmental pollutants because of their mutagenic, carcinogenic and toxic effects on living systems. The aim of this study was to examine and compare the ability and efficiency of selected bacterial isolates obtained from oil-con-taminated areas to biodegrade PAHs. The potential of the bacteria to biodeg-rade various aromatic hydrocarbons was assessed using the 2,6-dichlorophe-nolindophenol assay. Further biodegradation of PAHs was monitored by gra-vimetric and gas-chromatographic analysis. Among the eight bacterial isolates, identified on the basis of 16S rDNA sequences, two isolates, Planomicrobium sp. RNP01 and Rhodococcus sp. RNP05, had the ability to grow on and utilize almost all examined ...
BACKGROUND: The negative health effects of polycyclic aromatic hydrocarbons (PAHs) are well established for modern human populations but have so far not been studied in prehistoric contexts. PAHs are the main component of fossil bitumen, a naturally occurring material used by past societies such as the Chumash Indians in California as an adhesive, as a waterproofing agent, and for medicinal purposes. The rich archaeological and ethnohistoric record of the coastal Chumash suggests that they were exposed to multiple uptake pathways of bituminous PAHs, including direct contact, fume inhalation, and oral uptake from contaminated water and seafood. OBJECTIVES: We investigated the possibility that PAHs from natural bitumen compromised the health of the prehistoric Chumash Indians in California. CONCLUSIONS: Exposure of the ancient Chumash Indians to toxic PAHs appears to have gradually increased across a period of 7,500 years because of an increased use of bitumen in the Chumash technology, together ...
PAH is the short name for Polycyclic aromatic hydrocarbons. Thank goodness this molecule has a short name! These are long strings of carbon atoms which form a ring. (That accounts for the cyclic and hydrocarbon part of its name). An aromatic molecule is one which forms a benzene ring. Polycyclic means the molecule forms many rings. The only PAH which non-scientists may be familiar with is napthalene, the chemical in mothballs. PAHs form easily. PAH is very abundant in the solar system as well as in space. The red color in many interstellar clouds, such as this one comes from radiation in red wavelengths of PAH chemicals in the clouds. PAH is found in comets and in meteorites, even ones which come from Mars. This was especially important when scientists thought there might be fossils of ancient life in a Martian rock. Trees and other sophisticated plant life emit PAH as part of their photosynthesis/respiratory cycle. But the chief source of terrestrial PAH today is automobile emissions. ...
Several industries entailing exposure to polycyclic aromatic hydrocarbons (PAHs) are known or suspected carcinogens. A handful of studies have assessed the role of PAHs exposure in prostate cancer risk, but none has examined tumor aggressiveness or the influence of screening practices and detection issues. We aimed to examine the association between lifetime occupational exposure to PAHs and prostate cancer risk. Detailed work histories were collected from 1,929 prostate cancer cases (436 aggressive) and 1,994 controls from Montreal, Canada (2005-2012). Industrial hygienists applied the hybrid expert approach to assign intensity, frequency and certainty of exposure to benzo[a]pyrene, PAHs from wood, coal, petroleum, other sources, and any source, in each job held. Odds ratios (ORs) for prostate cancer risk associated with lifetime PAHs exposure, adjusted for age, ancestry, education, lifestyle and occupational factors, and 95% confidence intervals (CI), were estimated using unconditional logistic
The synthesis of TG in humans mainly involves exogenous and endogenous pathways. The exogenous pathway starts with the intestinal absorption of TG from dietary sources in the form CM [23]. In the endogenous pathway, TG is synthesized using fatty acids in the liver and it is carried by TG-rich VLDL into bloodstream [24]. Therefore, TG in the blood mainly exists in the form of CM and/or VLDL. In the present study, Sch B treatment increased serum TG levels in a time-/dose-dependent manner from 6 to 96 h post-dosing. However, the serum TC level was elevated between 24 and 48 h after Sch B treatment. Scotts plot analysis showed that the potency of Sch B-induced elevation in serum TG is about 15.8-fold higher than that of TC. Moreover, no significant changes were detected in serum HDL and LDL levels at all time points following the administration of Sch B (data not shown). High blood TG levels in both animals and humans result from either the suppression of TG catabolic pathway or promotion of TG ...
Polycyclic aromatic hydrocarbons (PAHs), including benzo[a]pyrene (BaP), are among the most prominent toxic air pollutants, posing a threat to human health because their metabolites and oxidation products are carcinogenic and mutagenic (1). PAHs are emitted into the atmosphere from incomplete combustion and biomass burning and by smoking and cooking in indoor environments. Due to its low vapor pressure, BaP resides mostly in the condensed phase, and heterogeneous oxidation of BaP by oxidants such as OH and O3 is a major atmospheric loss pathway (2). Laboratory measurements show rapid degradation of BaP against ozone when adsorbed to a variety of substrates such as water, ammonium sulfate, soot, and organic compounds (3⇓⇓-6).. Upon chemical aging in the atmosphere, PAH-containing particles are likely coated by semi- or low-volatile organic compounds, which are formed by multigenerational gas-phase oxidation of volatile organic compounds. Laboratory experiments have shown that organic coatings ...
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants in urban atmospheres. Several PAHs are known carcinogens or are the precursors to carcinogenic daughter compounds. Understanding the contributions of the various emission sources is critical to appropriately managing PAH levels in the environment. The sources of PAHs to ambient air in Baltimore, MD, were determined by using three source apportionment methods, principal component analysis with multiple linear regression, UNMIX, and positive matrix factorization. Determining the source apportionment through multiple techniques mitigates weaknesses in individual methods and strengthens the overlapping conclusions. Overall source contributions compare well among methods. Vehicles, both diesel and gasoline, contribute on average 16-26%, coal 28-36%, oil 15-23%, and wood/other having the greatest disparity of 23-35% of the total (gas- plus particle-phase) PAHs. Seasonal trends were found for both coal and oil. Coal was the dominate PAH source
Atmospheric bulk (wet and dry) samples were monthly collected in Masan and Heangam areas of Korea, to assess the deposition flux and seasonal variation of polycyclic aromatic hydrocarbons (PAHs). Deposition fluxes of PAHs in bulk samples were determined using gas chromatography coupled to mass spectrometer detector (GC/MSD). Particle deposition fluxes from Masan and Haengam areas varied from 13 to |TEX|$87\;g/m^2/year$|/TEX| and from 5 to |TEX|$52\;g/m^2/year$|/TEX|, respectively. PAHs deposition fluxes in atmospheric bulk samples in Masan and Haengam areas ranged from 135 to |TEX|$464\;{\mu}g/m^2/year$|/TEX| and from 62.2 to |TEX|$194\;{\mu}g/m^2/year$|/TEX|, respectively. Atmospheric deposition fluxes of particles and PAHs in this study were comparable to or slightly lower values than those from different locations in Korea and other countries. PAHs profiles of atmospheric deposition bulk samples showed slightly different from two sampling areas, however the predominant species of PAHs were
The activation, hydrogenation, and covalent coupling of polycyclic aromatic hydrocarbons (PAHs) are processes of great importance in fields like chemistry, energy, biology, or health, among others. So far, they are based on the use of catalysts which drive and increase the efficiency of the thermally- or light-induced reaction. Here, we report on the catalyst-free covalent coupling of nonfunctionalized PAHs adsorbed on a relatively inert surface in the presence of atomic hydrogen. The underlying mechanism has been characterized by high-resolution scanning tunnelling microscopy and rationalized by density functional theory calculations. It is based on the formation of intermediate radical-like species upon hydrogen-induced molecular superhydrogenation which favors the covalent binding of PAHs in a thermally activated process, resulting in large coupled molecular nanostructures. The mechanism proposed in this work opens a door toward the direct formation of covalent, PAH-based, bottom-up ...
Epidemiologic evidence suggests that automobile and truck mechanics are at increased risk of bladder cancer. For mechanics, used gasoline engine oil (UGEO) is a major occupational exposure. UGEOs contain polycyclic aromatic hydrocarbons (PAHs) formed during combustion in engine operation. Because these PAHs have low volatility, mechanics have potential dermal exposure. Many PAHs found in UGEO are
Polycyclic aromatic hydrocarbons (PAHs) were measured in airborne particles (PM10) collected in an urban site of São Paulo City, Brazil. Samples were Soxhlet extracted sequentially with dichloromethane and acetone, followed by solid phase fractionation. Increasing polar fractions (A-K) of dichloromethane and acetone extracts were obtained. Fractionated extracts were analyzed by gas chromatography/mass spectrometry and Salmonella microsuspension bioassay. Sixteen PAH compounds were quantified in dichloromethane B and C fractions, nevertheless the D and E fractions presented higher mutagenic activities. Concentrations of the individual PAHs ranged from 0.8 ng m−3 (perylene) to 12.8 ng m−3 (benzofluranthene), reaching a total concentration of 95.5 ng m−3. BaP/BgP and Pyr/BaP ratios indicated the presence of vehicular emissions and BghiP/Ind and Chr/BeP ratios suggested a contribution of wood combustion emissions. Further investigation is still necessary for a better understanding of the PAH ...
Polycyclic aromatic hydrocarbons (PAHs) are potential carcinogenic and hazardous compounds having raised appreciable environmental concerns around the world in recent decades. This research investigates the effect of soil washing on removal of PAHs in contaminated soil. The study was conducted by collecting soil samples from a petrochemical complex in south of Iran. Testing was carried out at three temperatures of 20°C, 40°C, and 80°C and washing periods of 30 min and 60 min. Moreover, two different concentrations of Triton X-100 and Brij 35 surfactants were used throughout the experiments. The results of this research indicated that the maximum removal efficiency of PAHs was obtained using Brij 35 at concentration of 5 g/L, temperature of 80°C and washing duration of 60 min. The highest removal efficacies for anthracene, naphthalene, fluorene, and benzo(a)pyrene in coarse and fine fractions of the samples occurred at 76.24%, 86.32%, 78.54%, 85.81% and 57.50%, 63.39%, 60.87%, 79.94%, ...
Abstract. In order to better understand the particle size distribution of polycyclic aromatic hydrocarbons (PAHs) and their source contribution to human respiratory system, size-resolved PAHs have been studied in ambient aerosols at a megacity Shanghai site during a 1-year period (2012-2013). The results showed the PAHs had a bimodal distribution with one mode peak in the fine-particle size range (0.4-2.1 µm) and another mode peak in the coarse-particle size range (3.3-9.0 µm). Along with the increase in ring number of PAHs, the intensity of the fine-mode peak increased, while the coarse-mode peak decreased. Plotting of log(PAH / PM) against log(Dp) showed that all slope values were above −1, suggesting that multiple mechanisms (adsorption and absorption) controlled the particle size distribution of PAHs. The total deposition flux of PAHs in the respiratory tract was calculated as being 8.8 ± 2.0 ng h−1. The highest lifetime cancer risk (LCR) was estimated at 1.5 × 10−6, which exceeded ...
Concentrations of polynuclear aromatic hydrocarbons in oysters were determined seasonally by sampling three stations at four sites in Galveston Bay (Texas). The four sites were Houston Yacht Club, Todds Dump, Confederate Reef, and Hanna Reef. The individual polynuclear aromatic hydrocarbons measured were naphthalene, 2-methylnaphthalene, 1-methylnaphthalene, biphenyl, 2,6-dimethylnaphthalene, acenaphthene, fluorene, phenanthrene, anthracene, 1-methylphenanthrene, fluoranthrene, pyrene, benz(a)anthracene, chrysene, benzo(e)pyrene, benzo(a)pyrene, perylene, and dibenz(a,h)anthracene. Pyrene had the single highest value at 537 ppb, while dibenz(a,h)anthracene was never above the limit of the quantitation (LOQ = 20 ppb). Each analyte was below the LOQ in at least one sample. Fluoranthrene had the highest mean concentration over the entire study at 129 ppb. The mean concentration of 1-methylnaphthalene, biphenyl, 2,6-dimethyl-naphthalene, acenaphthene, fluorene, anthracene, benz(a)anthracene, ...
Polycyclic aromatic hydrocarbons (PAHs) are present in both gaseous and particulate phases. These compounds are considered to be atmospheric contaminants and are human carcinogens. Many studies have monitored atmospheric particulate and gaseous phase
Fingerprint Dive into the research topics of Distribution patterns of polycyclic aromatic hydrocarbons (PAHs) in the sediments and fish at Mai Po Marshes Nature Reserve, Hong Kong. Together they form a unique fingerprint. ...
Mathematical chemistry is the area of research engaged in new application of Mathematics in Chemistry. Major areas of research in mathematical chemistry include chemical graph theory. Chemical graph theory applies graph theory to mathematical modeling of chemical phenomena. If G=(V(G),E(G)) is a connected graph,where V(G) is a non-empty set of vertices and E(G) is a set of edges, then the eccentric connectivity index of G (denoted by ξ(G)) was defined as ζ(G)= where dv is the degree of a vertex v and ε(v) is its eccentricity. In this study, we investigated the eccentric connectivity index of polycyclic aromatic hydrocarbons (PAHs).
PAHs in SD:Polycyclic aromatic hydrocarbons levels in street dust in the central area of Niterói City, RJ, Brazil 的翻译是:多环芳烃在SD:多环芳烃的含量在街道尘埃硝石ó我市,RJ的中心区,巴西 是什么意思?英文翻译中文,中文翻译英文,怎么说?-我要翻译网
Some biotic and abiotic aspects of the environmental chemistry of PAHs (polycyclic aromatic hydrocarbons) and PCDD/Fs (polycychlorinated dibenzodioxins and dibenzofurans) ...
Environmental fate of polycyclic aromatic hydrocarbons (PAHs) is a significant issue raising interest in bioremediation. Soil microorganism plays a vital role in degradat..
Trzesicka Mlynarz, D.; Ward, O.P., 1995: Degradation of polycyclic aromatic hydrocarbons (PAHs) by a mixed culture and its component pure cultures, obtained from PAH-contaminated soil
Effect of fatty acid on the formation of polycyclic aromatic hydrocarbons (PAHs) and the proposed formation mechanism during electric roasting - Author: Congcong Liu, Chong Wang, Keping Ye, Yun Bai, Xiaobo Yu, Chunbao Li, Guanghong Zhou
Polycyclic aromatic hydrocarbons (PAHs), benzene and toluene (BT) are ubiquitous toxic pollutants in the environment. Children are sensitive and susceptible to exposure to these contaminants. To investigate the potential oxidative DNA damage from the co-exposure of PAHs and BT in children, 87 children (aged 3-6) from a kindergarten in Guangzhou, China, were recruited. Ten urinary PAHs and four BT ...
There are two more issues that make barbecued meat unsafe for consumption:. 1. Another cancer-causing compound - polycyclic aromatic hydrocarbon (PAH) - also forms on barbecued meat when fat from the meat, drips off into the fire and causes a flare up of flames and smoke. PAHs have been classified as cancer causing agents by various organizations such as the Environmental Protection Agency and the International Agency for Research on Cancer. According to the Center for Disease Control in Atlanta, GA, we are exposed to PAHs through breathing air contaminated by wild fire or coal OR eating meat or foods that have been grilled.. 2. Hot dogs. Wow, do I even need to tell you how unhealthy hot dogs are? Research has shown that processed meat, such as that found in hot dogs or other smoked meats, increases ones risk of colorectal cancer, on average, by 21 percent for every 50 grams consumed daily! (A 50-gram serving is approximately the size of a typical hot dog.) A 2002 international study ...
ANALYSIS OF POLYCYCLIC AROMATIC HYDROCARBONS (PAH) COMPOUNDS FROM SEDIMENT IN THE WATERS KAYU BANGKOA PORT AND DEGRADATION OF PHENANTHRENE IN SEDIMENT BY USING KMNO4 OXIDIZER
The objective of this research project is to focus on the central hypothesis of the Southern California Particle Center and Supersite, which is that organic constituents associated with particulate matter-including quinones, other organic compounds (polycyclic aromatic hydrocarbons [PAHs], nitro-PAHs, and aldehydes/ketones), and metals-are capable of generating reactive oxygen species and acting as electrophilic agents. They have a central role in allergic airway disease such as asthma and cardiovascular effects through their ability to generate oxidative stress, inflammation, and immunomodulating effects in the lungs and airways. The specific objective of this research project is to extend our current knowledge of the size distribution of atmospheric PAHs present near freeways-located in the Los Angeles Basin and at an urban site-down to 10 nm aerodynamic diameter. ...
The purpose of this project is to better understand the interactions between two potentially hazardous, common contaminants; the prototype polycyclic aromatic hydrocarbon (PAH), benzo(a)pyrene (BP), and the heavy metal, cadmium (Cd). This is particularly important since cadmium was found to alter the level and activity of several enzyme systems that catalyze the conversion of BP to its reactive metabolites, and the detoxification and excretion of these metabolites. Experiments are designed to investigate the extent to which Cd, in environmentally realistic concentrations, is capable of altering: 1) the level and activity of some phase I and phase II enzymes involved in the breakdown and excretion of BP; 2) the BP metabolic profile (i.e., increases or decreases in the generation of carcinogenic/mutagenic metabolites); 3) immunocompetence; 4) the formation of stable BP-DNA adducts; 5) development of hepatic preneoplastic lesions; and 6) the development of liver cancers in the mummichog (Fundulus ...
A review is given of measurements of polycyclic aromatic hydrocarbons (PAH) in the work environment in general with emphasis upon Swedish measurements of benzo[a]pyrene not previously published in international literature. Finally, epidemiologic investigations on PAH exposed workers, as well as threshold limit values for PAH, are discussed.. ...
W13Z2 is a halotolerant polycyclic aromatic hydrocarbon (PAH)-degrading bacterium isolated from petroleum-contaminated drill cuttings in the Bohai Ocean. (4), V SSPACE. 2.0 (5), GapFiller v. 1.10 (6), and bwa v. 0.7.4 (7). Last assembly contains 69 contigs with an family members dominated the insertion series (IS) components as exposed by ISFinder (10). A complete of 695 secreted proteins were identified by SignalP v potentially. 4.0 (11). One clustered frequently interspaced brief palindromic do it again (CRISPR) component with 20 spacers was determined by CRISPRFinder (12). Typical nucleotide identification (ANI) evaluation (13) exposed that W13Z2 can be phylogenetically linked to PAO1 (70.5%) (14), NFM421 (69.55%) (15), ATCC 13867 (70.7%) (16), L48 (70.2%) (17), NK01 1110813-31-4 (70.5%) (18), SB3078 (70.0%) (19), RE*1/1/14 (69.7%) (20), KT2440 (69.8%) (21), NBRC106553 (70.8%) (22), A1501 (70.8%) (23), and pv. tomato DC3000 (69.2%) (24). Thirteen genes in charge of the degradation of PAHs and ...
Bioreclamation of Chlorinated Compounds & Polycyclic Aromatic Hydrocarbon Compounds 2(1) by Battelle Memorial Institute available in Hardcover on Powells.com, also read synopsis and reviews. This timely reference presents the state of the art of the emerging and rapidly changing field of...