Looking for online definition of polycyclic aromatic hydrocarbon in the Medical Dictionary? polycyclic aromatic hydrocarbon explanation free. What is polycyclic aromatic hydrocarbon? Meaning of polycyclic aromatic hydrocarbon medical term. What does polycyclic aromatic hydrocarbon mean?

TY - JOUR. T1 - Association between polycyclic aromatic hydrocarbon exposure and peripheral blood mononuclear cell DNA damage in human volunteers during fire extinction exercises. AU - Andersen, Maria Helena Guerra. AU - Saber, Anne Thoustrup. AU - Clausen, Per Axel. AU - Pedersen, Julie Elbæk. AU - Løhr, Mille. AU - Kermanizadeh, Ali. AU - Loft, Steffen. AU - Ebbehøj, Niels. AU - Hansen, Åse Marie. AU - Pedersen, Peter Bøgh. AU - Koponen, Ismo Kalevi. AU - Nørskov, Eva-Carina. AU - Møller, Peter. AU - Vogel, Ulla Birgitte. PY - 2018. Y1 - 2018. N2 - This study investigated a number of biomarkers, associated with systemic inflammation as well as genotoxicity, in 53 young and healthy subjects participating in a course to become firefighters, while wearing personal protective equipment (PPE). The exposure period consisted of a 3-day training course where the subjects participated in various live-fire training exercises. The subjects were instructed to extinguish fires of either wood or wood ...

The Koggala lagoon is a coastal wetland affected by a major oil spill and other anthropogenic pollution sources. In this study, gill and liver histological alterations and polycyclic aromatic hydrocarbon (PAH) exposure indicative bile fluorescence patterns of the fish species inhabiting the lagoon were examined in order to explore the potential biological impacts. Fixed wavelength fluorescence patterns in the bile of Mugil cephalus, Lutjanus russellii and Etroplus suratensis showed bioavailability of naphthalene type-, phenanthrene type-, pyrene type- and benzo(a)pyrene type- metabolites indicating recent exposure of the fishes to petrogenic and pyrogenic PAHs. Histological analysis revealed the occurrence of prominent gill and liver lesions, especially in the tissues of M. cephalus and L. russellii. Of the fish species examined, which included 43 individual fishes, the liver tissues of M. cephalus (two fish) and L. russellii (one fish) displayed foci of hepatocellular alterations with nodular ...

Zhigacheva I.. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, street Kosygin, 4, Moscow, 119334 Russia 1 pp. (accepted). The consequences of long-term exposure to polycyclic aromatic hydrocarbons (PAHs) and nitrosamines (NA) on the body began to be studied in detail more than 100-150 years ago [Proctor R. N., 2004; Scanlan R. A., 2004]. The researchers interest in these toxicants is associated with the high carcinogenic properties of PAHs and NAs. The bulk of PAHs in the environment is of anthropogenic origin. The main sources of PAHs are: household, industrial discharges, wash-outs, transport, accidents. The anthropogenic flux of PAHs, in particular benzo(a)pyrene (BP) is approximately 30 tons a year [Larin S. A. and co-authors, 2005]. Currently, the contamination by polycyclic aromatic hydrocarbons (PAHs) is global. Their presence is found in all elements of the natural environment (air, soil, water, biota) from the Arctic to Antarctica. Not less toxic nitrosamines ...

Our findings suggest that the association between PAH exposure and a cytokine storm may be mediated by AhR and NLRP3 expression among preschoolers.

AZEVEDO, Débora de A.; GERCHON, Elaine and REIS, Ederson O. dos. Monitoring of pesticides and polycyclic aromatic hydrocarbons in water from Paraíba do Sul River, Brazil. J. Braz. Chem. Soc. [online]. 2004, vol.15, n.2, pp.292-299. ISSN 0103-5053. http://dx.doi.org/10.1590/S0103-50532004000200021.. The Paraíba do Sul River, in the State of Rio de Janeiro, was studied for its water quality, by determining the levels of selected polycyclic aromatic hydrocarbons (PAHs) and pesticides from six sites in two cities, Resende and Campos dos Goytacazes, as they have industrial and agricultural activities. This study was carried out between July 2001 and March 2002. The method involved 200 mL samples taken by off-line, solid phase extraction by OASIS polymeric cartridges followed by gas chromatography-mass spectrometry (GC-MS). Recoveries and standard deviation of pesticides in non polluted real water sample spiked with a standard mixture were 82-119% and less then 20%. For PAH, recoveries and standard ...

The morphologies of heterogeneous clusters of polycyclic aromatic hydrocarbons (PAHs) are investigated using molecular modelling. Clusters of up to 100 molecules containing combinations of the different sized PAHs circumcoronene, coronene, ovalene, or pyrene are evaluated. Replica exchange molecular dynamics simulations using an all-atom force field parameterised for PAHs sample many configurations at high and low temperatures to determine stable low energy structures. The resulting cluster structures are evaluated using molecular radial distances and coordination numbers, and are found to be independent of initial configuration and the cluster sizes studied. Stable clusters consist of stacked PAHs in a core-shell structure, where the larger PAHs are found closer to the cluster core and the smaller PAHs are located on the cluster surface. This work provides novel insight into the molecular partitioning of heterogeneous aromatic clusters, with particular relevance to the structure of nascent soot ...

Bufadienolide is a chemical compound with steroid structure. Its derivatives are collectively known as bufadienolides, including many in the form of bufadienolide glycosides (bufadienolides that contain structural groups derived from sugars). These are a type of cardiac glycoside, the other being the cardenolide glycosides. Both bufadienolides and their glycosides are toxic; specifically, they can cause an atrioventricular block, bradycardia (slow heartbeat), ventricular tachycardia (a type of rapid heartbeat), and possibly lethal cardiac arrest. The term derives from the toad genus Bufo that contains bufadienolide glycosides, the suffix -adien- that refers to the two double bonds in the lactone ring, and the ending -olide that denotes the lactone structure. Consequently, related structures with only one double bond are called bufenolides,[citation needed] and the saturated equivalent is bufanolide. According to MeSH, bufadienolides and bufanolides are classified as follows: Polycyclic compounds ...

Resonantly stabilized radicals, such as propargyl, cyclopentadienyl, benzyl, and indenyl, play a vital role in the formation and growth of polycyclic aromatic hydrocarbons (PAHs) that are soot precursors in engines and flames. Pyrene is considered to be an important PAH, as it is thought to nucleate soot particles, but its formation pathways are not well known. This paper presents a reaction mechanism for the formation of four-ring aromatics, pyrene and fluoranthene, through the combination of benzyl and indenyl radicals. The intermediate species and transition structures involved in the elementary reactions of the mechanism were studied using density functional theory, and the reaction kinetics were evaluated using transition state theory. The barrierless addition of benzyl and indenyl to form the adduct, 1-benzyl-1H-indene, was found to be exothermic with a reaction energy of 204.2 kJ mol-1. The decomposition of this adduct through H-abstraction and H2-loss was studied to determine the ...

Despite the considerable knowledge of bacterial high-molecular-weight (HMW) polycyclic aromatic hydrocarbon (PAH) metabolism, the key enzyme(s) and its pleiotropic and epistatic behavior(s) responsible for low-molecular-weight (LMW) PAHs in HMW PAH-metabolic networks remain poorly understood. In this study, a phenotype-based strategy, coupled with a spray plate method, selected a Mycobacterium vanbaalenii PYR-1 mutant (6G11) that degrades HMW PAHs but not LMW PAHs. Sequence analysis determined that the mutant was defective in pdoA2, encoding an aromatic ring-hydroxylating oxygenase (RHO). A series of metabolic comparisons using high-performance liquid chromatography (HPLC) analysis revealed that the mutant had a lower rate of degradation of fluorene, anthracene, and pyrene. Unlike the wild type, the mutant did not produce a color change in culture media containing fluorene, phenanthrene, and fluoranthene. An Escherichia coli expression experiment confirmed the ability of the Pdo system to oxidize

Fluorene, a polycyclic aromatic hydrocarbon (PAH), is a precursor to other fluorene compounds. Fluorene and its derivative can be used as a precursor to fluorene-based dyes. - Mechanism of Action & Protocol.

The economy of the state of Tabasco is based on oil extraction. However, this imposes major effects to the environment and communities. Examples are the Polycyclic Aromatic Hydrocarbons (PAHs) that may be found in the soil, water and sediment of the region. Their volatility makes them available to living beings and results in genotoxic activity. The purpose of this study was to quantify the levels of PAHs in the air at several points in the state, and to analyze their relationship with possible damage to DNA on local inhabitants. Single Cell Gel Electrophoresis Assay (Comet Assay) was applied to peripheral blood lymphocytes of five groups of children between six and 15 years of age. PAH samples were analyzed following US/EPA TO-13-A method. Results indicated the presence in the air of most of the 16 PAHs considered as high priority by EPA, some of which have been reported with carcinogenic activity. Differences (p

Polycyclic aromatic hydrocarbons (PAHs) have garnered much attention due to their bioaccumulation, carcinogenic properties, and persistence in the environment. Investigation of the spatial distribution, composition, and sources of PAHs in sediments of three recreational marinas in San Diego Bay, California revealed significant differences among marinas, with concentrations in one site exceeding 16,000 ng g− 1. Hotspots of PAH concentration suggest an association with stormwater outfalls draining into the basins. High-molecular weight PAHs (4-6 rings) were dominant (, 86%); the average percentage of potentially carcinogenic PAHs was high in all sites (61.4-70%) but ecotoxicological risks varied among marinas. Highly toxic benzo(a)pyrene (BaP) was the main contributor (, 90%) to the total toxic equivalent quantity (TEQ) in marinas. PAHs in San Diego Bay marina sediments appear to be derived largely from pyrogenic sources, potentially from combustion products that reach the basins by aerial ...

Metallurgy is an industrial activity that is one of the largest contributors to soil contamination by metals. This contamination is often associated with organic compound contamination; however, little research has been aimed at the development of simultaneous processes for decontamination as opposed to treatments to heavy metals or organic compounds alone. This paper presents an efficient process to decontaminate the soils polluted with smelting by-products rich in Cu, Zn and polycyclic aromatic hydrocarbons (PAHs). A simultaneous treatment for metals and PAHs was also tested. The process is mainly based on physical techniques, such as crushing, gravimetric separation and attrition. For the finest particle size fractions, an acid extraction with H2SO4 was used to remove metals. The PAH removal was enhanced by adding surfactant during attrition. The total metal removals varied from 49% to 73% for Cu and from 43% to 63% for Zn, whereas a removal yield of 92% was measured for total PAHs. Finally, ...

In this application note it is shown that polycyclic aromatic hydrocarbon compounds (PAHs) can be effectively extracted from water samples using Strata PAH. In addition it is shown that humic acids, which often interfere with chromatographic separation, can be removed from the sample using the SPE sorbent, Strata® PAH. The Strata PAH provides consistent, high recoveries of all 16 analytes listed under EPA Method 550.1.

The mutagenicity of crude extracts and subfractions of two samples of a reference sewage sludge material and two sewage sludges from two wastewater treatment plants (WWTP), one urban and the other one urban mixed with industrial, was assessed using an Ames fluctuation assay based on 384-well microtiter plates with liquid cultures. Crude extracts of sludges were obtained by ultrasonic extraction with dichloromethane/methanol, and further column fractionation yielded two fractions, one of which containing mutagenic polycyclic aromatic hydrocarbons (PAHs). Quantitative analysis performed by gas chromatography-mass spectrometry gave sum concentrations of the 16 PAHs listed as priority pollutants by the U.S. Environmental Protection Agency at levels between 1,305 and 2,442 μg/kg. Subjecting crude extracts and column fractions to the mutagenicity assay with Salmonella strains TA98 and TA100 provided good qualitative correlation between the presence of mutagenic PAH and the induction of gene ...

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Sorption is a key factor in determining the fate of polycyclic aromatic hydrocarbons (PAHs) in the environment. Here, PAH sorption is proposed as the sum of two mechanisms: absorption into a biogenic, organic carbon (OC) fraction and adsorption onto a combustion-derived, black carbon (BC) fraction. To study BC adsorption, a 375ʻC thermal oxidation method was employed to remove OC and isolate the BC fraction. Test studies showed that nitrogen-containing macromolecules charred during this pretreatment causing a positive bias to the BC measurement. Meanwhile, the oxidation of relatively small BC particles underestimated the total BC content in non-charring samples. Models based on carbon oxidation were then proposed to estimate reasonably the total BC and OC contents of sediment samples. The adsorption of pyrene onto isolated BC particles was then studied by constructing a nonlinear isotherm, which was characterized with a BC-normalized distribution coefficient and a Freundlich exponent. Pyrene ...

The possibility that condensation reactions, leading to polycyclic aromatic hydrocarbon (PAH) formation in protoplanetary atmospheres, could occur with negative aromatic species, such as stabilized anionic ortho-benzyne (o-C6H−4), is analysed through accurate quantum dynamical modelling of the initial steps. Once the primary electron attachment on the neutral o-C6H−4 has taken place, producing the corresponding metastable negative ion, the evolution of this resonant anionic intermediate in terms of its energy locations and lifetimes suggests the possibility of a radiationless stabilization by a very rapid intramolecular vibrational redistribution of the excess energy carried by the attached electron. The possible involvement of this stabilized highly reactive molecular anion in an ensuing PAH synthesis is also qualitatively discussed. ...

Apart from widely known anthropogenic pollutants as SO2, NOx, CO2, CO, there are another dangerous substances emitted to the air named polycyclic aromatic hydrocarbons (PAH). In the air they occur in a form of vapours and aerosols deposited on dust particles of 10 μm (PM 10) and 2.5 μm (PM 2.5) in diameter. In cities, the air polluted by gases and atmospheric particulate was analysed using special automatic or semi-automatic equipment or analytic procedures. That is why a powerful development of bioanalytical techniques based on using organisms as bioindicators is observed in recent years. The lichens are the most frequently used organisms in bioindication. The purpose of this research is to evaluate air pollution by PAHs in urban agglomeration with the use of Hypogymnia physodes (L.)Nyl. The research was performed in two hundred thousand occupants in south-east Poland in 2004-2007. The lichens placed on tree branches of 30 cm on 4 crossroads, and the 3 branches were put in each research ...

It has previously been demonstrated that [14C]-labeled polycyclic aromatic hydrocarbons (PAHs) can be oxidized to 14CO2 in anoxic, PAH-contaminated, marine harbor sediments in which sulfate reduction is the terminal electron-accepting process. However, it has not previously been determined whether t …

The effect of flavonoids (flavone, morin hydrate and 3-hydroxyflavone)on the microbial mineralisation of polycyclic aromatic hydrocarbons (PAHs) in soil slurry by the indigenous microbial communities has been investigated. The rates and extents of 14C-PAHs (14C-naphthalene, 14C-phenanthrene and 14C-pyrene)mineralisation in artificially spiked soils were monitored in the absence and presence of flavonoids applied at three different concentrations (50, 100 and 200 µg kg-1) either as single compounds or as a mixture of flavonoids (flavone, morin hydrate and 3-hydroxyflavone at a 1:1:1 ratio). Respirometric and microbial assays were monitored in fresh (0 d) and pre-incubated (28 d) artificially spiked soils following amendment with flavonoids. The highest extents of14C-naphthalene, 14C-phenanthrene and 14C-pyrenemineralisation (P< 0.001) were obtained in fresh artificially spiked soils amended with 100 µg kg

Polycyclic aromatic hydrocarbons (PAH) are naturally occurring compounds found in the environment. They result from natural events such as volcanic activity and bush fires, and are also produced by industrial processes. PAH can also be produced by some cooking processes, such as barbequing, smoking, roasting and frying. In 2004, Food Standards Australia New Zealand (FSANZ) undertook an analytical survey of PAH in 35 foods available in Australia and consumed in a typical diet. Foods analysed were taken from those collected as part of the 22nd Australian Total Diet Study (ATDS). As such, not all foods known to contain PAH were included in the survey. This is a limitation of the survey in estimating exposure to PAH from Australian foods.. The results of this study have been used in a dietary exposure estimate for a number of age groups in the Australian population. Dietary exposure of the general population was determined for benzo[a]pyrene, a representative PAH known to be genotoxic and ...

Polycyclic aromatic hydrocarbons in edible grain: A pilot study of agricultural crops as a human exposure pathway for environmental contaminants using wheat as a model crop ...

A tandem-cartridge system was established for studying colloid formation and physical state distribution of trace polycyclic aromatic hydrocarbons (PAHS) in water. The effectiveness of the method for measuring the trace PAH colloids was demonstrated. With aqueous samples prepared by adding the PAH solutes with a small amount of organic solvent carrier, the potential of colloid formation increased with the hydrophobicity and concentration of the solute, but the incipient concentration for the colloid formation may be far lower than the aqueous solubility of the solute. After formation in water, the colloids showed remarkable stability at room temperature, and the stability was greatly reduced by elevated temperature and the presence of a small amount of inorganic electrolytes. The possible mechanism of destabilization of the colloids was discussed, and the mechanism might be of utility in providing insights into the physical state distribution of the solutes in various water samples. However, ...

Download Free Full-Text of an article BIODEGRADATION OF POLYCYCLIC AROMATIC HYDROCARBON BY A HALOTOLERANT BACTERIAL CONSORTIUM ISOLATED FROM MARINE ENVIRONMENT

Isotopic dilution gas chromatography combined with high resolution mass spectrometry (GC/HRMS) has overwhelming advantages with respect to the accuracy of congener-specific ultratrace analysis of complex persistent organic pollutants (POPs) in environmental matrices. However, an isotopic dilution GC/HRMS method for analysis of chlorinated and brominated polycyclic aromatic hydrocarbons (Cl-PAHs and Br-PAHs) using 13C-labelled congeners as internal standards has not been established. In this study, a method for identification and quantification of 38 congeners of Cl-PAHs and Br-PAHs in atmosphere and stack gas samples from waste incinerators was developed using the isotopic dilution GC/HRMS technique. The instrumental detection limits of the GC/HRMS method ranged from 0.2pg to 1.8pg for Cl-PAH congeners, and 0.7pg to 2.7pg for Br-PAH congeners, which were about three orders of magnitude lower than those of the GC/quadrupole MS method. This new method developed was also the first to enable ...

Read Peroxidases from alfalfa roots: Catalytic properties and participation in degradation of polycyclic aromatic hydrocarbons, Russian Journal of Plant Physiology on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.

Strata™-PAH from Phenomenex Inc. is a new sorbent designed for the isolation of polycyclic aromatic hydrocarbons (PAH) in environmental samples. Strata-PAH solid phase extraction (SPE) sorbents target these analytes while simultaneously removing humic acids that can interfere with chromatographic separation of environmental samples such as soil and water.

Clark, B.W.; Cooper, E.M.; Stapleton, H.M.; Di Giulio, R.T., 2013: Compound- and mixture-specific differences in resistance to polycyclic aromatic hydrocarbons and PCB-126 among Fundulus heteroclitus subpopulations throughout the Elizabeth River estuary (Virginia, USA)

Hydrocarbons are toxic To Pets. Hydrocarbons are liquids that are commonly found in your garage. Examples are, engine oil, gasoline, diesel fuels, wood stains.

Two important limitations of our study were the small sample size and the lack of PAH exposure data. Because of the small sample size, single observations in this study may have large potential influence on our findings. Our results need to be interpreted cautiously until consistent findings are observed in similar studies with larger populations. We observed an increase in PAH metabolite levels during work, but we could not determine the relative contribution of occupational exposure sources for this increase. A future study with personal exposure measures would allow us to identify different sources of variation of PAH exposures and possibly strengthen the association between occupational exposure and DNA damage. Despite these important limitations, we were able to observe statistically significant associations between 8-OHdG and 1-OHPyr after 6 h of work. 1-OHPyr is the main metabolite of pyrene and has been widely accepted as the gold standard of biomarkers of exposure to PAHs.55 ,56 In this ...

Environmental exposure to carcinogens may contribute to increasing breast cancer rates and geographic variation in breast cancer incidence in the United States. One class of chemicals that has received much attention are the polyaromatic hydrocarbons that are ubiquitous in the environment and occur in cigarette smoke. The cytochrome P450 1A1 (CYP1A1) gene codes for an enzyme that contributes to aryl hydrocarbon hydroxylase activity, which is involved in the metabolism of polyaromatic hydrocarbons. Genotypic variants of CYP1A1 have been associated with increased aryl hydrocarbon hydroxylase activity, and some epidemiological studies suggest that women with the variant genotype(s) are at increased risk for breast cancer.. We prospectively evaluated the associations between the CYP1A1 polymorphisms and breast cancer risk, as well as the potential modification of these associations by cigarette smoking, in a case-control study nested within the Nurses Health Study. We analyzed the T→C transition ...

1.0 Polycyclic Aromatic Hydrocarbons. Polycyclic Aromatic Hydrocarbons (PAHs) are a class of chemicals that occur naturally in coal, crude oil and petrol. They are also produced when coal, oil gas, wood, garbage, and tobacco are burned. PAHs generated from these sources can bind to or form small particles in the air.. 1.1 Adverse health effects of PAHs. The health effects from environmental exposure to low levels of PAHs are presently not fully known. Several of the PAHs and some specific mixtures of PAHs are considered to be cancer-causing chemicals.. DWER considers that short term exposure to PAHs may cause minor health impacts such as skin irritation while long term health effects include impacts on immunity, respiratory problems and cancer. Toxicity of PAHs is influenced by the nature of PAHs, dose and exposure.. The National Pollution Inventory website that states:. Exposure can irritate the eyes, nose, throat, and bronchial tubes. Skin contact can cause irritation or a skin allergy. ...

abstracts re toxicity of polycyclic aromatic carbohydrates: Hubner: Murray 2004.05.15 From: R. Hubner ,roland.hubner at health.fgov.be, Subject: degradation of polycyclic aromatic carbohydrates... Date: Friday, May 14, 2004 7:22 PM Dear bionetters, I would be very grateful if a kind soul could point out to me any comprehensive review paper, book chap, web publication or report that has detailed information about how inhaled PACs are metabolized by a human body and how many different (good?) methods are available to monitor such products... Presumably, such information might have been compiled to evaluate the impact on public health of, e.g., NYs burning Twin Towers and similar exposures to smoke... Thank you so much for your goodwill. With kindest regards, R. Hübner ************************************************************** Cancer Res. 2000 Jul 15; 60(14): 3749-52. Cigarette smoking, CYP1A1 MspI and GSTM1 genotypes, and colorectal adenomas. [ 21 references ] Inoue H, Kiyohara C, Marugame ...

in Accreditation and Quality Assurance (2006), 11(1-2), 38-43. In the determination of contaminants (dioxins, polychlorinated biphenyls, polyaromatic hydrocarbons), cell-based assays are useful methods for screening purposes: they are mainly characterized by high ... [more ▼]. In the determination of contaminants (dioxins, polychlorinated biphenyls, polyaromatic hydrocarbons), cell-based assays are useful methods for screening purposes: they are mainly characterized by high sample throughput and lower costs than the Mass Spectrometry (MS)-based methods. Although cell-based assays can be sensitive enough for the determination of dioxins and related substances in agreement with the presently tolerable limits in food and feed (Regulation No. 2375/2001/EC and Directive 2003/57/EC respectively), their lack of specificity make their use rather questionable in control laboratories. In this paper, we present and compare results obtained from the analysis of a limited number of feed samples by both gas ...

The structure of a PAH influences whether and how the individual compound is carcinogenic.[72][76] Some carcinogenic PAHs are genotoxic and induce mutations that initiate cancer; others are not genotoxic and instead affect cancer promotion or progression.[76][77]. PAHs that affect cancer initiation are typically first chemically modified by enzymes into metabolites that react with DNA, leading to mutations. When the DNA sequence is altered in genes that regulate cell replication, cancer can result. Mutagenic PAHs, such as benzo[a]pyrene, usually have four or more aromatic rings as well as a bay region, a structural pocket that increases reactivity of the molecule to the metabolizing enzymes.[78] Mutagenic metabolites of PAHs include diol epoxides, quinones, and radical PAH cations.[78][79][80] These metabolites can bind to DNA at specific sites, forming bulky complexes called DNA adducts that can be stable or unstable.[74][81] Stable adducts may lead to DNA replication errors, while unstable ...

Soil quality standards are based on partitioning and toxicity data for laboratory-spiked reference soils, instead of real world, historically contaminated soils, which would be more representative. Here 21 diverse historically contaminated soils from Sweden, Belgium, and France were obtained, and the soil-porewater partitioning along with the bioaccumulation in exposed worms (Enchytraeus crypticus) of native polycyclic aromatic compounds (PACs) were quantified. The native PACs investigated were polycyclic aromatic hydrocarbons (PAHs) and, for the first time to be included in such a study, oxygenated-PAHs (oxy-PAHs) and nitrogen containing heterocyclic PACs (N-PACs). The passive sampler polyoxymethylene (POM) was used to measure the equilibrium freely dissolved porewater concentration, C-pw, of all PACs. The obtained organic carbon normalized partitioning coefficients, K-TOC, show that sorption of these native PACs is much stronger than observed in laboratory-spiked soils (typically by factors 10 ...

Polycyclic aromatic hydrocarbon (PAH) content and Ames test mutagenic activity of exhaust particulate matter from a diesel engine burning fuel containing the barium (7440393) based additive Lubrizol-565 were evaluated. A heavy duty air cooled engine commonly used in underground mining equipment was used for the test. The additive was tested at concentrations of 0.75, 1.5 and 3.0 grams per liter in

Article Effect of activated carbon or biochars on toxicity of different soils contaminated by mixture of native polycyclic aromatic hydrocarbons and heavy metals. Activated carbon (AC) and biochars (BCS and BCW) were added to the soils sampled from a...

Background. The capital city of Prague becomes one of the most polluted localities of the Czech Republic. The effect of exposure to carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) adsorbed onto respirable air particles (PM2.5, ,2.5 \#956;m) on DNA adducts and chromosomal aberrations was repeatedly studied in the groups of policemen working in the downtown area as well as in bus drivers. Methods. Ambient air particles (PM10, PM2.5) and (c-PAHs) were monitored using VAPS sampler, personal exposure to c-PAHs was evaluated using personal samplers during working shift. DNA adducts were analysed in lymphocytes by 32P-postlabeling assay, chromosomal aberrations by conventional cytogenetic analysis and fluorescent in situ hybridization (FISH), cotinine in urine, plasma levels of vitamins A, E and C by HPLC, , cholesterol and triglycerids using commercial kits. Polymorphisms of metabolic genotypes (GSTM1, GSTP1, GSTT1, EPHX1, CYP1A1-MspI) and DNA repair genotypes (XRCC1 and XPD) were determined by ...

This section needs work. Why are we degrading catechol? What part did we use? What is the number?. Catechol is another toxic compound found in tailings ponds that is a by-product of polyaromatic hydrocarbon metabolism (Vaillancourt et al., 2006, Schweigert et al., 2001)). The chemical properties of catechol allow it to react with biomolecules like DNA, proteins and membranes (Schweigert et al., 2001). These interactions can cause serious damage including DNA breakage, enzyme inactivation and membrane uncoupling (Schweigert et al., 2001). Catechol is characterized as having a benzene ring with two hydroxyl groups emanating from adjacent carbons. It can be converted to 2-hydroxymuconic acid by the enzyme catechol 2,3-dioxygenase, encoded by the xylE gene on the Tol plasmid of Pseudomonas putida (Nakai et al., 1983). This product can then be further metabolized to pyruvate and acetaldehyde; products which can then be routed into the fatty acid biosynthesis pathway and converted to alkanes with the ...

Catechol is a toxic compound found in tailings ponds that is a by-product of polyaromatic hydrocarbon metabolism (Vaillancourt et al., 2006, Schweigert et al., 2001)). The chemical properties of catechol allow it to react with biomolecules, causing cellular damage including DNA damage, enzyme inactivation and membrane uncoupling (Schweigert et al., 2001). Catechol is characterized as having a benzene ring with two hydroxyl groups at the 2,3 position. It can be converted to 2-hydroxymuconic acid by the enzyme catechol 2,3-dioxygenase, encoded by the xylE gene on the Tol plasmid of Pseudomonas putida (Nakai et al., 1983).. Currently the registry has two BioBricks available of xylE. One contained xylE with its native ribosome-binding site (BBa_J33204), while the other part contained xylE under the glucose-repressible promoter cstA (BBa_K118021). Given that E. coli is grown in the presence of glucose, we designed a new construct to keep xylE repressed by using the TetR promoter (BBa_R0040).. ...

Polycyclic aromatic hydrocarbons (PAHs) are by-products of combustion. There are a large number of compounds that are classified as PAHs; some, such as benzo(a)pyrene, are carcinogenic. We have published research showing that pyrene is a good generic marker of PAH exposure and that urinary 1-hydroxypyrene is a suitable biomarker. HSE has set a GB guidance value for 1-hydroxypyrene in urine (4 µmol/mol creatinine).. Product Code: PE11630. Price: £58.00 (VAT free). ...

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Lipidomic-based investigation into the regulatory effect of Schisandrin B on palmitic acid level in non-alcoholic steatotic livers, Hiu Yee Kwan, Xuyan Niu, Wenlin Dai, Tiejun Tong, Xiaojuan Chao, Tao Su, Chi Leung Chan, Kim Chung Lee, Xiuqiong Fu, Hua Yi, Hua Yu, Ting Li, Anfernee Kai Wing Tse, Wang Fun Fong, Si-Yuan Pan, Aiping Lu, and Zhi-Ling Yu. ...

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Humans spend most of their lives in indoor environments; hence, indoor exposure to air pollution may constitute a large part of the total exposure to air pollution. Polycyclic aromatic hydrocarbons are well known for their mutagenicity and carcinogenicity and are ubiquitous in urban environments as a result of combustion from e.g. vehicular traffic. Polycyclic aromatic hydrocarbons associated to air particulate matter in indoor environments originates from several sources including: cooking and heating, outdoor sources, smoking, candle and incense burning. Infiltration has been suspected to be one major source of indoor polycyclic aromatic hydrocarbons. In this study, four different air filter materials intended for mechanical ventilation were tested for their capability to remove particle bound polycyclic aromatic hydrocarbons and other genotoxic compounds from a real urban aerosol. Particles were sampled at two highly trafficked locations in Stockholm using a sampling system capable of sample ...

The invention discloses a method for brewing schisandra chinensis fruit wine. The method is characterized by being carried out according to the following steps: a first stage of fermentation, namely mixing fresh schisandra chinensis fruits and white granulated sugar into a ceramic jar to ferment according to the mass ratio of (3-5):1 until lixivium is carmine, the schisandra chinensis becomes yellow-green, shriveled and wizened schisandra chinensis is generated and acerb wine taste exists; a second stage of fermentation, namely weighing a corn liquor which is 48-52% of total mass of the fresh schisandra chinensis fruits and the white granulated sugar, pouring into the ceramic jar to stand for 90-150 days, weighing 4-6% of medlar, 4-6% of acanthopanax skin, 4-6% of radix curcumae, 4-6% of root of kudzu vine and 4-6% of pine needle, containing in another container to soak for 30-50 days by using the corn liquor, and filtering out traditional Chinese medicine soaking liquid; a third stage of

TY - JOUR. T1 - Identification of Polycyclic Aromatic Hydrocarbons (PAHs) in the black crusts of Sicilian stone monuments: distribution and sources. AU - Gianguzza, Antonio. AU - Orecchio, Santino. AU - Piazzese, Daniela. PY - 2004. Y1 - 2004. N2 - Polycyclic Aromatic Hydrocarbons are a family of compounds with known carcinogenic potential; their properties of lipophilicity, low water solubility and adsorption to particles and sediments make them a potentially dangerous group of chemicals and a threat to the environment and its bio-resources. The concentrations of total Polycyclic Aromatic Hydrocarbons (PAHs) and 19 individual compounds in 8 black crusts sampled from historical building of Palermo (Italy) were analyzed, by gas chromatography/mass spectrometry (GC/MS) in selected ion monitoring (SIM) mode. PAH concentrations ranged from 78 to 9798 g/Kg of dry matrix. The resulting distributions and molecular ratios of specific compounds have been discussed in terms of sample location and ...

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div class=citation vocab=http://schema.org/,,i class=fa fa-external-link-square fa-fw,,/i, Data from ,span resource=http://link.library.missouri.edu/portal/Concentrations-of-polynuclear-aromatic/UXw8S2rAHqs/ typeof=Book http://bibfra.me/vocab/lite/Item,,span property=name http://bibfra.me/vocab/lite/label,,a href=http://link.library.missouri.edu/portal/Concentrations-of-polynuclear-aromatic/UXw8S2rAHqs/,Concentrations of polynuclear aromatic hydrocarbons and inorganic constituents in ambient surface soils, Chicago, Illinois, 2001-02, Robert T. Kay [and others] ; in cooperation with the Chicago Department of Environment,/a,,/span, - ,span property=potentialAction typeOf=OrganizeAction,,span property=agent typeof=LibrarySystem http://library.link/vocab/LibrarySystem resource=http://link.library.missouri.edu/,,span property=name http://bibfra.me/vocab/lite/label,,a property=url href=http://link.library.missouri.edu/,University of Missouri ...

Twelve workers from a coke plant in The Netherlands participated in an intensive skin monitoring programme combined with personal air sampling and biological monitoring during five consecutive eight hour workshifts. The purpose of the study was to make a quantitative assessment of both the dermal and respiratory intake of polycyclic aromatic hydrocarbons (PAHs). Pyrene was used as a marker compound for both dermal and respiratory exposure to PAHs. The biological measure for the internal exposure to PAHs was urinary 1-OH-pyrene concentration. Measurements on exposure pads at six skin sites showed that mean total skin contamination of the 12 workers ranged between 21 and 166 micrograms pyrene a day. The dermal uptake of pyrene ranged between 4 and 34 micrograms/day, which was about 20% of the pyrene contamination on skin. The mean concentration of total pyrene in the breathing zone air of the 12 coke oven workers ranged from 0.1 to 5.4 micrograms/m3. The mean respiratory uptake of pyrene varied ...

The separation of different ring numbered polyaromatic hydrocarbons (PAHs) was accomplished by using cetyltrimethylammonium bromide (CTAB) in capillary electrokinetic chromatography. In order to increase the solubilities and selectivities of PAHs, acetonitrile (ACN) was used as an organic modifier. Under the optimised conditions, 11 aromatic compounds were separated within 14.5 min in a running electrolyte containing 10 mM phosphate, 30 mM CTAB, and 40% ACN at pH 6.0. The effects of CTAB and ACN concentrations, voltage and pH on the resolution were investigated. Reproducibilities of migration times range between 0.55 and 1.27 R.S.D.% and peak areas between 1.02 and 7.23 R.S.D.%. Limit of detections (LODs) range between 0.09 and 2.24 mu g ml(-1). This new and fast separation method of PAHs was applied to cooked oil sample. (c) 2005 Elsevier B.V. All rights reserved. ...

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Tar and nicotine levels have been made to conform to EU standards as of 1 July 2004, but data on tobacco-derived carcinogenic compounds, such as PAH, in Chinese cigarettes are lacking in the literature. Levels of tar, nicotine, carbon monoxide and PAH were measured in 20 cigarette brands purchased in China between 2003 and 2004. Higher nicotine and tar levels were found in Chinese cigarettes than in European brands just 3 months before the above deadline; carcinogenic PAH levels were about 1.5 fold higher than in European cigarettes, but analysed singly, the mean value of benzo(a)pyrene (B(a)P) and dibenzo(a,h)anthracene (DBA), the most potent carcinogenic PAH yields, were 2.4 and 4.4 fold higher, respectively. Tar levels were well correlated with carcinogenic PAH (r = 0.53, P , 0.01), thus providing an easily measurable parameter for ranking various cigarette brands in developing countries where more sophisticated techniques might not be feasible for lack of funds and expertise.. ...

Polycyclic Aromatic Hydrocarbons (PAHs) are environmental pollutants that have received considerable attention because of their carcinogenic and mutagenic effects. Due to the extensive amount of data suggesting the hazards of these compounds, 16 PAHs are on the Environmental Protection Agency (EPA) Priority Pollutant List. These compounds are often emitted into the atmosphere by way of combustion processes. Thus, analysis of these compounds during coal combustion is an important task. Three 1000-hour coal combustion burns were performed using the 0.1 MW (0.3 m) bench-scale Fluidized Bed Combustor (FBC) in the Combustion Laboratory at Western Kentucky University. The data for this thesis were collected from the second and third 1000-hour experiments. An in-situ sampling system was designed for 16 PAHs specified by EPA, which consisted of a glass wool filter, condenser, glass fiber filter, Teflon filter, and Tenax. The filters and Tenax were extracted by methylene chloride and hexane, respectively,

The effect of ultra-high temperature (UHT) on production of polycyclic aromatic hydrocarbons (PAHs) on the surface of beef steaks was determined. Beef steaks were treated with five treatments, raw, UHT, UHT/grill marks, UHT/grill marks/microwave, and charcoal grilled. Four PAHs, benzo[a]pyrene, benz[a]anthracene, benzo[b]fluoranthene, and benzo[k]fluoranthene, were quantified. High performance liquid chromatography (HPLC) and gas chromatography (GC) were used to purify and analyze the PAH extracts, respectively. Levels of PAH found on charcoal-grilled steaks were higher than those observed in the literature. A balanced incomplete block design was used to analyze the data. There were no significant differences among the treatments in the production of the benzofluoranthenes. There were significant increases in production of benzo[a]pyrene and benz[a]anthracene when grill marks were applied to the UHT steak. Microwaving significantly decreased the levels of benzo[a]pyrene and benz[a]anthracene. The

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants, known human lung carcinogens, and potent mammary carcinogens in animal models. However, the association between PAHs and breast cancer in women is unclear. Vehicular traffic is a major source of ambient PAH exposure. This study evaluates the association between residential exposure to vehicular traffic-related PAHs and risk of breast cancer, overall and by tumor subtype, and within strata of nucleotide excision repair and base excision repair genotypes and fruit/vegetable intake. For this population-based study, residential histories, dietary intake, and other factors were assessed in 1996-1997 for 1,508 newly diagnosed breast cancer cases and 1,556 controls. Residential traffic exposure estimates were reconstructed using a validated model for the years 1960 through 1995. The following single nucleotide polymorphisms were genotyped: ERCC1 8092C/A, OGG1 Ser326Cys, XPA -4A/G, XPD Lys751Gln and Asp312Asn, XPF ...

One hundred and twenty (120) fingerlings of Clarias gariepinus (mean weight: 0.96 ± 0.1g) were randomly exposed to 4 experimental treatments of petroleum, based on LC50 values (6.4mg/L of crude oil, 8.7mg/L of petrol, 8.0mg/L of kerosene and 7.8mg/L of diesel oil) and replicated thrice, to determine polycyclic aromatic hydrocarbons (PAH) in exposed fish for 96 h. There was no significant difference (P > 0.05) in total (PAHs) between crude oil (97.1 ng/uL) and diesel (97.2 ng/uL) exposed fish and also between petrol (53.2 ng/uL) and kerosene (49.6 ng/uL) exposed fish, but there was a significant difference (P < 0.05) in PAH levels of the crude oil/diesel exposed -groups of fish compared to petrol/kerosene exposed -groups of fish (97.1/97.2 and 53.2/49.6 ng/uL). Naphthalene correlated positively to benzo a anthracene (r=0.672, (P < 0.05), benzo b fluoranthene (r=0.681, P < 0.05) and chrysene (r=0.615, P < 0.05) but did not correlate to fluorene. Benzo a anthracene correlated

The successful application of forensic geology to contamination studies involving natural systems requires identification of appropriate endmembers and an understanding of the geologic setting and processes affecting the systems. Studies attempting to delineate the background, or natural, source for hydrocarbon contamination in Gulf of Alaska (GOA) benthic sediments have invoked a number of potential sources, including seep oils, source rocks, and coal. Oil seeps have subsequently been questioned as significant sources of hydrocarbons present in benthic sediments of the GOA in part because the pattern of relative polycyclic aromatic hydrocarbon (PAH) abundance characteristic of benthic GOA sediments is inconsistent with patterns typical of weathered seep oils. Likewise, native coal has been dismissed in part because ratios of labile hydrocarbons to total organic carbon (e.g. PAH:TOC) for Bering River coal field (BRCF) sources are too low - i.e. the coals are over mature - to be consistent with GOA

heptane lifted flames using various soot inception species has been conducted. In a recent study by the authors, it was found that the soot formation and growth regions in lifted flames were not adequately represented by using acetylene alone as the soot inception species. Comparisons with a conceptual model and available experimental data suggested that the location of soot formation regions could be better represented if polycyclic aromatic hydrocarbon (PAH) species were considered as alternatives to acetylene for soot formation processes. Since the local temperatures are much lower under low temperature combustion conditions, it is believed that significant soot mass contribution can be attributed to PAH rather than to acetylene. To quantify and validate the above observations, a reduced ...

Produced water constitutes the largest volume of waste from offshore oil and gas operations and is composed of a wide range of organic and inorganic compounds. Although treatment processes have to meet strict oil in water regulations, the definition of oil is a function of the analysis process and may include aliphatic hydrocarbons which have limited environmental impact due to degradability whilst ignoring problematic dissolved petroleum species. This thesis presents the partitioning behavior of oil in produced water as a function of temperature and salinity to identify compounds of environmental concern. Phenol, p-cresol, and 4-tert-butylphenol were studied because of their xenoestrogenic power; other compounds studied are polycyclic aromatic hydrocarbon PAHs which include naphthalene, fluorene, phenanthrene, and pyrene. Partitioning experiments were carried out in an Innova incubator for 48 hours, temperature was varied from 4ﾟC to 70ﾟC, and two salinity levels of 46.8‰ and 66.8‰ ...

The intertidal zone-a transitional boundary between terrestrial and marine environments-has important ecological functions, and receives polycyclic aromatic hydrocarbons (PAHs) from human activities, but how and to what extent anthropogenic factors influence the distribution of PAHs in this important niche remain largely unknown. Here we measured the distribution of United States Environmental Protection Agency priority PAHs in samples of intertidal sediments from across more than 4,500 km of Chinas coastline. The total PAH concentrations ranged from 2.3 to 1,031.7 ng g−1 sediment (dry weight) and all PAHs showed positive correlations with total organic carbon (TOC). TOC-normalized high-molecular-weight (HMW) PAH concentrations, but not TOC-normalized low-molecular-weight (LMW) PAHs, were positively correlated with TOC. Moreover, population size and economic development influenced TOC-normalized HMW PAH concentrations, whereas urbanization had a major influence on TOC-normalized LMW PAHs. Human

A review of airborne polycyclic aromatic hydrocarbons (PAHs) in EgyptAssmaa M. El-Mekawy1, Atef M.F. Mohammed1, Salwa K. M. Hassan11Air Pollution Depa...

The clustering of polycyclic aromatic hydrocarbon (PAH) molecules is investigated in the context of soot particle inception and growth using an isotropic potential developed from the benchmark PAHAP potential. This potential is used to estimate equilibrium constants of dimerisation for five representative PA

Dive into the research topics of Occupational exposure to polycyclic aromatic hydrocarbons: A cross-sectional study in bars and restaurants in Santiago, Chile. Together they form a unique fingerprint. ...

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Sigma-Aldrich offers abstracts and full-text articles by [Di Hu, Yunfeng Cao, Rongrong He, Na Han, Zhihui Liu, Lijing Miao, Jun Yin].

Reactive oxygen species (ROS)-mediated activation of inflammasome is involved in the development of a wide spectrum of diseases. We aimed to investigate whether (-)schisandrin B [(-)Sch B], a phytochemical that can induce cellular antioxidant response, can suppress the inflammasome activation. Results showed that (-)Sch B can induce an nuclear factor erythroid 2-related factor 2-driven thioredoxin expression in primary peritoneal macrophages and cultured RAW264.7 macrophages. A 4-h priming of peritoneal macrophages with LPS followed by a 30-min incubation with ATP caused the activation of caspase 1 and the release of IL-1β, indicative of inflammasome activation. Although LPS/ATP did not activate inflammasome in RAW264.7 macrophages, it caused the ROS-dependent c-Jun N-terminal kinase1/2 (JNK1/2) activation and an associated lactate dehydrogenase (LDH) release in RAW264.7 macrophages, an indication of cytotoxicity. (-)Sch B suppressed the LPS/ATP-induced activation of caspase 1 and release of ...

Rhodococcus sp. 124 is a Gram-positive soil bacterium being developed for the manufacture of (-)cis-(1S,2R)-1-aminoindan-2-ol, a key precursor in the production of the HIV-1 protease inhibitor CrixivanTM, from the aromatic hydrocarbon indene. Rhodococcus sp. 124 was grown by batch fermentation in the presence of naphthalene and indene to measure changes in gene expression and aromatic hydrocarbon metabolism with DNA microarray technology. Genes were selected for microarray analysis based on functional annotation assignments made by the Consensus Annotation by Phylogeny Anchored Sequence Alignment (CAPASA) program, a high throughput system for automated functional annotation assignment of DNA sequence similarity search results. CAPASA was validated by comparison to several methods of annotation, and the agreement to other methods ranged from 75-94%. Microarray results were analyzed by the newly described method of trigonometric deconvolution, a mathematical system for the measurement of changes ...

Some polycyclic aromatic hydrocarbons (PAH) are known carcinogens and workplace PAH exposure may increase the risk of cancer. Monitoring early cancer-related changes can indicate whether the exposure is carcinogenic. Here, we enrolled 151 chimney sweeps, 152 controls, and 19 creosote-exposed male workers from Sweden. We measured urinary PAH metabolites using LC/MS/MS, the cancer-related markers telomere length (TL) and mitochondrial DNA copy number (mtDNAcn) using qPCR, and DNA methylation of lung cancer-related genes F2RL3 and AHRR using pyrosequencing. The median 1-hydroxypyrene (PAH metabolite) concentrations were highest in creosote-exposed workers (8.0 μg/g creatinine) followed by chimney sweeps (0.34 μg/g creatinine) and controls (0.05 μg/g creatinine). TL and mtDNAcn did not differ between study groups. Chimney sweeps and creosote-exposed workers had significantly lower methylation of AHRR CpG site cg05575921 (88.1% and 84.9%, respectively) than controls (90%). Creosote-exposed workers ...

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This thesis is an effort to understand electronic structure and optical properties of low-dimensional conjugated molecules such as polyatomic aromatic hydrocarbons and nanoribbons composed of perylene monomers in addition to transport and magnetic properties of model conjugated systems such as ladders and junctions. we carry out a systematic study of the electronic states of several PAHs using the PPP model which incorporates long-range electron correlations. In all the molecules studied by us, we find that the 2A state is below the 1B state and hence none of them will be fluorescent in the gaseous phase. The singlet-triplet gap is more than one-half of the singlet-singlet gap in all cases and hence none of these PAHs can be candidates for improved solar cell efficiencies in a singlet fission. We discuss in detail the properties of the electronic states which include bond orders and spin densities (in triplets) of these ...

Benzene Aromatic hydrocarbons are carbon and hydrogen compounds in the molecule of which there is a benzene ring. The most important representatives of aromatic hydrocarbons are benzene and its homologs… ...

A method for the determination of polycyclic aromatic hydrocarbons (PAH) in carbonaceous materials and on particulate Batter produced in the atmosphere during the electrolytic reduction by various methods in the metallurgical industry is presented. The PAH are extracted into hexane with the aid of ultrasound, which is shown to be more efficient than the conventional Soxhlet thimble technique. Cyclohexane and hexane are shown to be more selective extractants for PAH than benzene or acetone. Hexane is preferred because it has a lower boiling point than cyclohexane. Three metnods of identification were investigated. These included thin-layer chromatography (TLCJ, gas chromatography (GO using retention times and indices and mass spectrometry (GC-MS). Hexane containing 2 % by volume of N.N -dimethylformaoide was used for the development of a thin-layer chromatograa. This resolved only ten of the twenty PAH investigated adequately. The non-polar OV-101 capillary column used in the GC-MS work did not ...

Quantification of European Union (EU)-priority polycyclic aromatic hydrocarbons (PAHs) in plant matrices is a crucial task. Various methods for enrichment and preconcentration, such as the preloaded-pipette tip solid‑phase extraction (SPE) (1), are available. Nevertheless, analyte recovery as a result of homogenization, sample preparation, and extraction are rarely discussed in the field of phytopharmacy. This study deals with the recovery in dry plant extracts, which are typically used in phytopharmaceuticals and reflect the actual polycyclic aromatic hydrocarbon content in the commercially available end product (2). The aim of this study was to monitor benzo[a]pyrene, benzo[a]anthracene, chrysene, and benzo[b]fluoranthene loss of spiked samples as a result of commonly-used sample pretreatment, extraction, filtering, and evaporating techniques in 1:1 (v/v) cyclohexane-ethyl acetate primulae flos and sambuci flos dry extracts. Results showed that improper sample preparation can lead to false ...

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Nucleation is an important, yet poorly understood step in soot formation. Here, the importance of reactive PAH dimerization in reducing soot nucleation reversibility is investigated by simulating soot formation in a so-called

adshelp[at]cfa.harvard.edu The ADS is operated by the Smithsonian Astrophysical Observatory under NASA Cooperative Agreement NNX16AC86A ...

Understanding the kinetics of aromatic-DNA adducts in target tissues and white blood cells (WBC) would enhance the applicability of DNA adducts in WBC as surrogate source of DNA in biomonitoring studies. In the present study, rats were acutely exposed to benzo[a]pyrene (B[a]P; 10 mg/kg body wt) via intratracheal (i.t.), dermal and oral administration. DNA adducts were analyzed in relevant target organs and WBC by nuclease P1 enriched 32P-post-labeling at 1, 2, 4, 11 and 21 days after exposure. Additionally, the internal dose was assessed by measurement of urinary excretion of 3-hydroxy-B[a]P (3-OH-B[a]P). Total B[a]P-DNA adduct levels in WBC were highest after i.t. and oral administration, whereas DNA adducts were hardly detectable after dermal exposure. Highest adduct levels were reached at 2 days after exposure. In lung tissue, DNA adduct levels reached maximal values at 2 days and were highest after i.t., oral and dermal exposure, respectively. DNA adduct levels were significantly lower in ...

PAH concentrations were determined in a dated sediment core collected from Esthwaite Water (EW), a seasonally anoxic lake in the English Lake District. The most dramatic variations are associated with increased PAH fluxes from 1900 and a sub-surface maximum (29 mg m−2 year−1) in the late 1960s to early 1970s, followed by a fivefold decrease in fluxes to the sediment-water interface. This trend is believed to reflect enhanced fossil fuel burning, followed by general improvements in combustion technologies, shifts in the fuels used for domestic space heating and the implementation of various emission controls on releases from certain known PAH sources. When the relative contributions from individual compounds to the ∑PAH were plotted as vertical profiles, coherent time trends emerged. Perylene dominated the pre-1900 sedimentary PAH composition, contributing ,75% to the ∑PAH mixture. The perylene profile provides good evidence for both natural and anthropogenic sources to EW. The ratios of ...

The ultraviolet, visible, and near-infrared absorption spectra of naphthalene (C10H8) and its radical ion (C10H8/+/), formed by vacuum ultraviolet irradiation, were measured in argon and neon matrices at 4.2 K. The associated vibronic band systems and their spectroscopic assignments are discussed together with the physical and chemical conditions governing ion production in the solid phase. The absorption coefficients were calculated for the ion and found lower than previous values, presumably due to the low polarizability of the neon matrix.

Copyright © 2020 by The Trustees of Columbia University in the City of New York, Lamont -Doherty Earth Observatory. All rights reserved ...

Das Institut für Produktqualität mit Sitz in Berlin führt nach dem neusten Stand der Wissenschaft und Technik mit den modernsten Geräten und Reagenzien Lebensmittel- und Futtermittelanalysen durch und erstellt Prüfberichte und Gutachten.

The Linked Data Service provides access to commonly found standards and vocabularies promulgated by the Library of Congress. This includes data values and the controlled vocabularies that house them. Datasets available include LCSH, BIBFRAME, LC Name Authorities, LC Classification, MARC codes, PREMIS vocabularies, ISO language codes, and more.

Polycyclic aromatic hydrocarbon (PAH) samples in particles were collected with a PM 10 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....

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Estimating impacts of wood combustion on ambient levels of PAHs is challenging. In this study effect of residential wood combustion on the benzo[a]pyrene concentrations in the air of Helsinki metropolitan area was studied, using ambient air measurements, emission estimates and dispersion modeling. Combining all this information enabled a quantitative characterization of the influence of residential wood combustion, which was found to be the main local source and more important than for PM2.5 ...

2-Methylnaphthalene is a polycyclic aromatic hydrocarbon (PAH). On February 22, 2014, NASA announced a greatly upgraded database for detecting and monitoring PAHs, including 2-methylnaphthalene, in the universe. According to NASA scientists, over 20% of the carbon in the universe may be associated with PAHs, possible starting materials for the formation of life ...

Norbornadiene is a bicyclic hydrocarbon and an organic compound. Norbornadiene is of interest as a metal-binding ligand, whose complexes are useful for homogeneous catalysis. It has been intensively studied owing to its high reactivity and distinctive structural property of being a diene that cannot isomerize (isomers would be anti-Bredt olefins ...

We have applied the method of optical detection of magnetic resonance (ODMR) to a number of polycyclic aromatic hydrocarbons for the purpose of measuring the rates of intersystem crossing for the individual spin sub-levels of the triplet state. These findings, along with other data from the literature will be examined in an attempt Co offer a qualitative explanation of the triplet state dynamics observed. Our approach will be to utilize the descriptive framework proposed by Henry and $Siebrand^{1}$ and Metz, et $al.^{2}$ and recently employed by Antheunis, Schmidt and van der $Waals^{3}$ to explain their results on nonradiative transitions in a series of nitrogen containing derivatives of anthracene. Our study suggests that nonradiative inter-system crossing may be qualitatively understood and predicted on the basin of spin orbit coupling interactions, energy levels, and the symmetry of the molecule. This analysis will be presented along with conclusions applicable to planar organic systems in ...

Its that time of year again! The grills are coming out and the steaks, burgers, and brats are plentiful. Its enough to send any vegan off the deep end. Unfortunately, as it seems with all good things, grilling comes with a serious health risk - cancer. How can something as innocent as chowing on a freshly grilled, grassfed rib-eye be a health hazard? Rest assured, the meat is NOT to blame!!. Grilling creates two types of potentially cancer causing agents; polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HCAs). PAHs are a product of the smoke that is generated from the meats fat drippings. The smoke surrounds the food and the PAHs are transferred from the smoke to the surface of the meat. HCAs are formed when meats are grilled at high temperatures for a long time. Studies have demonstrated a link between HCAs and the development of breast, colon, stomach and prostate tumors. Yes Arnold, Its a tumor.. I know exactly what youre thinking… EVERYTHING causes cancer these days, ...