Bibliografías temáticas / Pyrene

Índice

Artículos de revistas
Tesis
Libros
Capítulos de libros
Actas de conferencias
Informes

Literatura académica sobre el tema "Pyrene"

Autor: Grafiati

Publicado: 4 de junio de 2021

Última modificación: 7 de septiembre de 2023

Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros

Elija tipo de fuente:

Consulte las listas temáticas de artículos, libros, tesis, actas de conferencias y otras fuentes académicas sobre el tema "Pyrene".

Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.

También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.

Artículos de revistas sobre el tema "Pyrene"

Babu, Srinivasarao Arulananda y Arup Dalal. "Pd(II)-Catalyzed Directing-Group-Aided C–H Arylation and Alkylation of Pyrene Core: Synthesis of C1,C2- and C1,C10-Disubstituted Pyrene Motifs". Synthesis 53, n.º 18 (31 de marzo de 2021): 3307–24. http://dx.doi.org/10.1055/a-1472-0881.

Texto completo

Resumen

AbstractWe report the application of the Pd(II)-catalyzed, directing-group-aided C–H arylation/alkylation tactics to functionalize the pyrene core, especially, the relatively inaccessible C2 and K-region C10 positions of the pyrene core and augmentation of the library of pyrene derivatives with C1,C2- and C1,C10-disubstituted pyrene motifs. The Pd(II)-catalyzed β-C–H arylation/alkylation of the C2-position of pyrene-1-carboxamide possessing an 8-aminoquinoline directing group yielded various C1,C2-disubstituted pyrenes. Similarly, the Pd(II)-catalyzed selective γ-C–H arylation/alkylation of the C10-position of N-(pyren-1-yl)picolinamide, possessing a picolinamide directing group, yielded various C1,C10-disubstituted pyrenes. Examples of C(9)–H arylation of pyrene-1-carboxamide and the removal of the directing group after the C–H arylation/alkylation reactions were also shown. The structures of representative pyrene derivatives were confirmed by the X-ray structure analysis. Given the importance of the pyrene derivatives in various fields of chemical sciences, this report is a contribution towards augmentation of the library of pyrene derivatives with C1,C2- and C1,C10-disubstituted pyrene amide motifs.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Silva, Beatriz E. Ruiz, Edward K. Koepf, Leslie D. Burtnick y Nicholas J. Turro. "Monomer and excimer fluorescence of horse plasma gelsolin labelled with N-(1-pyrenyl)iodoacetamide". Biochemistry and Cell Biology 70, n.º 7 (1 de julio de 1992): 573–78. http://dx.doi.org/10.1139/o92-088.

Texto completo

Resumen

Horse plasma gelsolin was labelled with the sulfhydryl-specific fluorescent reagent N-(1-pyrenyl)iodoacetamide. The level of incorporation of probe was 1.6 ± 0.3 mol pyrene/mol gelsolin. The circular dichroism spectrum of pyrenyl-gelsolin and its ability to interact with muscle actin were not different from that found for unmodified gelsolin. The emission from pyrenyl-gelsolin was dominated by a broad emission band centred near 483 nm, characteristic of the presence of pyrene excimers. Analysis of excitation spectra for the monomer and excimer-type fluorescence suggested that ground-state interactions may occur between adjacent pyrenes in the gelsolin structure. In the case either of excimer formation or of ground-state pyrene–pyrene interactions in doubly labelled gelsolin molecules, the modified Cys residues must be in close proximity in the folded protein structure. Thermal denaturation of gelsolin could be monitored by observing the decrease in excimer emission that accompanied heating and unfolding of the tertiary structure. While heat treatment alone did not eliminate excimer fluorescence, digestion of gelsolin with chymotrypsin completely abolished such emission. Also, pyrenyl-gelsolin prepared and studied in 6 M guanidine-HCl exhibited fluorescence characteristic of pyrene monomers exclusively.Key words: gelsolin, pyrene excimer fluorescence, fluorescence lifetime, thermal denaturation.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Ashley, David L., Elizabeth R. Barnhart, Donald G. Patterson y Robert H. Hill. "Identification of Polychlorinated Pyrenes and Pyrene-Addition Products Using Proton Nuclear Magnetic Resonance Techniques". Applied Spectroscopy 41, n.º 7 (septiembre de 1987): 1194–99. http://dx.doi.org/10.1366/0003702874447428.

Texto completo

Resumen

Nuclear magnetic resonance (NMR) techniques are used to determine the chlorination pattern on a number of chlorinated pyrenes and pyrene-addition products. Determining chemical shifts, couplings, and longitudinal relaxation rates makes the unequivocal assignment of these molecules possible. Chlorination under the conditions described here were found to follow the normal orientation rules for pyrene. Spectral parameters obtained from these molecules are consistent enough to allow further application to unknown compounds. This should simplify assigning NMR spectra to other chlorinated pyrene standards.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Orehovec, Iva, Marija Matković, Isabela Pehar, Dragomira Majhen y Ivo Piantanida. "Bis-Pyrene Photo-Switch Open- and Closed-Form Differently Bind to ds-DNA, ds-RNA and Serum Albumin and Reveal Light-Induced Bioactivity". International Journal of Molecular Sciences 22, n.º 9 (6 de mayo de 2021): 4916. http://dx.doi.org/10.3390/ijms22094916.

Texto completo

Resumen

Newly designed and synthesized diarylethene (DAE) derivatives with aliphatic amine sidearms and one with two pyrenes, revealed excellent photo-switching property of central DAE core in MeOH and water. The only exception was bis-pyrene analogue, its DAE core very readily photochemically closed, but reversible opening completely hampered by aromatic stacking interaction of pyrene(s) with cyclic DAE. In this process, pyrene fluorescence showed to be a reliable monitoring method, an open form characterized by strong emission at 480 nm (typical for pyrene-aggregate), while closed form emitted weakly at 400 nm (typical for pyrene-DAE quenching). Only open DAE-bis-pyrene form interacted measurably with ds-DNA/RNA by flexible insertion in polynucleotide grooves, while self-stacked closed form did not bind to DNA/RNA. For the same steric reasons, flexible open DAE-bis-pyrene form was bound to at least three different binding sites at bovine serum albumin (BSA), while rigid, self-stacked closed form interacted dominantly with only one BSA site. Preliminary screening of antiproliferative activity against human lung carcinoma cell line A549 revealed that all DAE-derivatives are non-toxic. However, bis-pyrene analogue efficiently entered cells and located in the cytoplasm, whereby irradiation by light (315–400 nm) resulted in a strong, photo-induced cytotoxic effect, typical for pyrene-related singlet oxygen species production.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Launen, Loren, Linda Pinto, Christine Wiebe, Eberhard Kiehlmann y Margo Moore. "The oxidation of pyrene and benzo[a]pyrene by nonbasidiomycete soil fungi". Canadian Journal of Microbiology 41, n.º 6 (1 de junio de 1995): 477–88. http://dx.doi.org/10.1139/m95-064.

Texto completo

Resumen

The purpose of this study was to determine the ability of nonbasidiomycete soil fungi to oxidize pyrene (four rings) and benzo[a]pyrene (BaP) (five rings). Fungi were isolated from five different soils in which the polycyclic aromatic hydrocarbon content ranged from 0.8 to 80 μg/g dry soil. Approximately 50% of the isolates in all sites were able to oxidize pyrene. The pyrene-oxidizing species belonged to all fungal divisions except basidiomycetes. The most common were Penicillium spp. of the subgenus Furcatum and these dominated the more contaminated soils. Penicillium janthinellum and Syncephalastrum racemosum exhibited the most rapid rates of pyrene oxidation. The major pyrene metabolites were identified by proton NMR and mass spectrometry as 1-pyrenol, 1,6- and 1,8-pyrenediol, and the 1,6- and 1,8-pyrenequinones. A high correlation was found between the ability to oxidize pyrene and BaP. As with pyrene, approximately 50% of the fungal isolates tested oxidized BaP to 9-hydroxy-BaP. Eighty percent of the pyrene-oxidizing strains were also able to metabolize BaP.Key words: fungi, polycyclic aromatic hydrocarbons, biotransformation, bioremediation, cytochrome P-450.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Babu, B. Ravindra, Mads D. Sørensen, Patrick J. Hrdlicka, Smriti Trikha, Ashok K. Prasad, Virinder S. Parmar y Jesper Wengel. "Novel nucleic acid architectures involving locked nucleic acid (LNA) and pyrene residues: Results from an Indo-Danish collaboration". Pure and Applied Chemistry 77, n.º 1 (1 de enero de 2005): 319–26. http://dx.doi.org/10.1351/pac200577010319.

Texto completo

Resumen

We report herein our results for locked nucleic acid (LNA)-type oligonucleotides containing pyrene residues. Pyrene has a large hydrophobic and planar surface area and is therefore a potential intercalating unit; furthermore, it is interesting as a fluorescent tag when covalently bound to DNA. Synthesis and hybridization of conformationally locked universal base surrogates are described together with efficient interstrand communication as shown by the formation of pyrene excimer bands for duplexes containing 2'-N-(pyren-1-yl)methyl-2'-amino-LNA monomers positioned in a zipper-like manner within a DNA duplex.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Mimura, Yuki, Tomoki Nishikawa, Ryo Fuchino, Shiho Nakai, Nobuo Tajima, Mizuki Kitamatsu, Michiya Fujiki y Yoshitane Imai. "Circularly polarised luminescence of pyrenyl di- and tri-peptides with mixed d- and l-amino acid residues". Organic & Biomolecular Chemistry 15, n.º 21 (2017): 4548–53. http://dx.doi.org/10.1039/c7ob00503b.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Winnik, Françoise M., Alexander Adronov y Hiromi Kitano. "Pyrene-labeled amphiphilic poly-(N-isopropylacrylamides) prepared by using a lipophilic radical initiator: synthesis, solution properties in water, and interactions with liposomes". Canadian Journal of Chemistry 73, n.º 11 (1 de noviembre de 1995): 2030–40. http://dx.doi.org/10.1139/v95-251.

Texto completo

Resumen

Fluorescently labeled amphiphilic poly-(N-isopropylacrylamides) (PNIPAM) substituted with a N-[4-(1-pyrenyl)butyl]-N-n-octadecyl group at the chain end were prepared by free-radical polymerization in dioxane of N-isopropylacrylamide (NIPAM) using 4,4′-azobis{4-cyano-N,N-[4-(1-pyrenyl)butyl]-n-octadecyl}pentanamide as the initiator. The solution properties of the polymers in water were studied as a function of polymer concentration and temperature. Quasi-elastic light-scattering measurements and fluorescence experiments monitoring the pyrene excimer and pyrene monomer emissions revealed the presence of multimolecular polymeric micelles below the lower critical solution temperature (LCST) of PNIPAM. These underwent partial, reversible reorganization as they were heated above the LCST. The interactions of the pyrene-labeled amphiphilic PNIPAM with dimyristoylphosphatidylcholine (DMPC) liposomes have been examined in water at 25 °C. From fluorescence experiments it was established that the polymeric micelles are disrupted irreversibly upon contact with the liposomes. The anchoring of the polymer chains occurs by insertion of their hydrophobic tail within the phospholipidic bilayer, as evidenced from a large decrease of the pyrene excimer emission relative to pyrene monomer emission. The copolymers remained anchored within the bilayer as the temperature of the copolymer–liposome suspension was raised above the LCST of PNIPAM. Keywords: liposome, poly-(N-isopropylacrylamide), fluorescence, micelles.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Ruiu, Andrea, Mireille Vonlanthen, Sandra M. Rojas-Montoya, Israel González-Méndez y Ernesto Rivera. "Unusual Fluorescence Behavior of Pyrene-Amine Containing Dendrimers". Molecules 24, n.º 22 (12 de noviembre de 2019): 4083. http://dx.doi.org/10.3390/molecules24224083.

Texto completo

Resumen

A new class of pyrene-based dendrimers, characterized by the presence of a 1,4,7,10-Tetraazacyclododecane (cyclen) unit as the core, was studied by SSF (steady-state fluorescence) and SPC (single-photon counting fluorescence). The photophysical behavior of these dendrimers was studied in THF, DMF and DMSO solution. The typical signals for pyrene-labeled molecules were recorded in each solvent, showing the representative fluorescence spectra: the corresponding emissions of monomer and excimer of the pyrene chromophore are observed. Unexpectedly, the typical quenching of tertiary amine on the pyrene emission was not observed in these dendrimers. Quenching studies were performed by adding up to 3 equivalents of trifluoroacetic acid (TFA). To our knowledge, this is the first report of pyrene’s unquenching behavior by a tertiary amine.

Los estilos APA, Harvard, Vancouver, ISO, etc.

de Robillard, Guillaume, Oumayma Makni, Hélène Cattey, Jacques Andrieu y Charles H. Devillers. "Towards sustainable synthesis of pyren-1-yl azoliums via electrochemical oxidative C–N coupling". Green Chemistry 17, n.º 9 (2015): 4669–79. http://dx.doi.org/10.1039/c5gc01142f.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Más fuentes

Tesis sobre el tema "Pyrene"

Melidonie, Jason, Junzhi Liu, Yubin Fu, Jan J. Weigand, Reinhard Berger y Xinliang Feng. "Pyrene-Fused s-Indacene". ACS Publications, 2018. https://tud.qucosa.de/id/qucosa%3A36576.

Texto completo

Resumen

One antiaromatic polycyclic hydrocarbon (PH) with and without solubilizing tert-butyl substituents, namely s-indaceno[2,1-a:6,5-a′]dipyrene (IDPs), has been synthesized by a four-step protocol. The IDPs represent the longitudinal, peri-extension of the indeno[1,2-b]fluorene skeleton towards a planar 40 π-electron system. Their structures were unambiguously confirmed by X-ray crystallographic analysis. The optoelectronic properties were studied by UV/vis absorption spectroscopy and cyclic voltammetry. These studies revealed that peri-fusion renders the IDP derivatives with a narrow optical energy gap of 1.8 eV. The maximum absorption of IDPs is shifted by 160 nm compared to the parent indenofluorene. Two quasi-reversible oxidation as well as reduction steps indicate an excellent redox behavior attributed to the antiaromatic core. Formation of the radical cation and the dication was monitored by UV/vis absorption spectroscopy during titration experiments. Notably, the fusion of s-indacene with two pyrene moieties lead to IDPs with absorption maxima approaching the near infrared (NIR) regime.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Mangnall, T. I. "Pyrene based Metal Organic Frameworks". Thesis, University of Liverpool, 2016. http://livrepository.liverpool.ac.uk/3000462/.

Texto completo

Resumen

Metal Organic Frameworks (MOFs) are a type of multifunctional porous material. Comprised of metal centres or metal clusters known as Secondary Building Units (SBUs) linked together into an extended 1, 2 or 3 dimensional structure by bridging organic ligands coordinated to the metal SBUs. MOFs offer the opportunity to customise the pore size and chemical functionality of the fra mework. The degree of customisation possible from the wide array of different metal clusters and organic ligands MOFs have been proposed for many applications such as gas storage, separation, catalysis, photocatalysis, sensing and drug delivery. In this thesis the synthesis and characterisation of pyrene based MOFs is presented and the hydrogen evolution photocatalytic applications are tested. This thesis contains details on three different MOFs. Firstly a new aluminium pyrene MOF which was characterised and tested for photocatalysis and CO 2 and CH 4 storage applications; which also had platinum nanoparticles successfully incorporated within the pores. Secondly a very recently reported zirconium pyrene MOF was made, had its photocatalytic applications exp lored for the first time and had platinum deposited within the pores. Thirdly a new Europium Pyrene MOF was developed using high throughput techniques and its new structure was calculated from single crystal XRD.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Launen, Loren A. "Pyrene biodegradation by Penicillium janthinellum SFU403". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0022/NQ51887.pdf.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

TEIXEIRA, SILVIO CESAR GODINHO. "PYRENE ADSORPTION IN BRAZILIAN SOILS STUDY". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2008. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=12309@1.

Texto completo

Resumen

PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
A maioria dos estudos envolvendo adsorção de hidrocarbonetos policíclicos aromáticos (HPA) é realizada em solos de regiões de clima frio. Como em países tropicais as características dos processos pedológicos e os solos resultantes são diferentes há necessidade desses estudos em solos brasileiros. Com esse objetivo, este trabalho estudou a adsorção de pireno em sete categorias representativas de solos brasileiros: Argissolo, Latossolo Amarelo, Latossolo Vermelho acriférrico, Latossolo Vermelho Amarelo distrófico, Neossolo Quartzarênico, Organossolo e Vertissolo. Foram realizados ensaios de adsorção usando massa de amostra dos solos de 2,5 g e 5,0 g. Para todas as categorias de solos estudados observou-se diferentes tempos de equilíbrio tanto nos estudos feitos com 2,5 g de solo quanto naqueles com 5,0 g. Nos experimentos realizados com a menor massa (2,5 g), observou-se que os perfis das curvas de adsorção para o Latossolo Vermelho acriférrico e para o Vertissolo apresentaram diferenças significativas sugerindo maiores competições pelos sítios de sorção. Para as demais categorias não foi observada diferença significativa no perfil das curvas de adsorção. Verificou-se ainda que não foi somente o teor de matéria orgânica responsável pelo equilíbrio do processo de adsorção como esperado. A presença de argilas expansivas pode ter contribuição para o aumento da quantidade de pireno adsorvida no solo (Q), como foi verificado para o Vertissolo. Foi observado que as categorias de solos estudadas apresentam características físico-químicas e Koc muito diferentes indicando que o processo de adsorção de pireno nestes solos não pode ser considerado como um modelo único. Neste trabalho o processo de adsorção de pireno foi descrito pelas isotermas de Langmuir (Argissolo e Latossolo Vermelho acriférrico), de Langmuir com linearização (Latossolo Vermelho Amarelo distrófico), de BET (Neossolo Quartzarênico) e isoterma linear (Vertissolo). Os resultados obtidos para o Latossolo Amarelo não se ajustam aos modelos de isotermas testados.
Since most of the studies that involve polycyclic aromatic hydrocarbons (PAH) adsorption in soils are make in regions of temperate or cold climate. In tropical countries, the characteristics of the pedological processes and the resultant soils are quite different there is the necessity of working on new studies in the Brazilian soils. In this dissertation, the pyrene adsorption in seven differents Brazilian soils was studied: Clays soils, Yellow Latosoil, Red Anionic Latosoil, Red Yellow Latosoil, Neosoil Quartzarenic, Organic soil and Vertisoil. Two groups of adsorption tests were carried out, in the first one we used samples of 2.5g of soil and in the second one the soil mass was increased to 5.0g. To all soils, it was possible to observe that, when the initial mass of soil was changed, different times of reaction were needed so that the sorption process could reach the thermodynamic equilibrium. And yet because of this bigger competition, the profile of the Red Anionic Latosoil and Vertisoil curves, obtained by the usage of different pyrene/soil relations, presented meaningful differences when compared. The presence of the swelling clays may contribute to the increase of the quantity of pyrene adsorpted in the soil (Q), such as happened in the Vertisoil. In this work, was found the Langmuir`s isotherms to Clays soils and Red Yellow Latosoil, BET to Neosoil Quartzarenic and linear isotherm to Vertisoil.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Karabaeva, Kanykey E. "Photochemistry of Masked Pyrene-4,5-Dione". Bowling Green State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1371083757.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Castle, Saffron Jane. "Sensing bilayer pressures with pyrene-labelled probes". Thesis, Imperial College London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.281742.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Carter, Tom Scott. "Synthetic lectins with pyrene at the core". Thesis, University of Bristol, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.702443.

Texto completo

Resumen

Carbohydrates are displayed on the outer layer of cells by glycoproteins and glycolipids, forming the glycocalyx. These carbohydrates hold a huge amount of information, acting as a cell 'barcode', facilitating communication and acting as targets for pathogens. The proteins which recognise carbohydrates in nature are called lectins. Synthetic mimics of these proteins, binding through noncovalent interactions in water, are termed 'synthetic lectins'. The design and synthesis of these synthetic lectins could allow reading of parts of the cell barcode and give a greater understanding of the operation of natural lectins. Furthermore, robust selective synthetic lectins could act as sensors for important sugars such as N-acetylglucosamine (important in protein regulation) or blood glucose levels (for surgery or diabetics). However the design of synthetic lectins that are able to overcome the hydromimetic nature of carbohydrates and show selectivity between carbohydrates is very difficult. Within this body of work a variety of synthetic lectin architectures are presented, with their design, synthesis and binding properties reported. Two designs within are of particular note. Firstly, a highly cationic pyrene based platform shaped receptor (PyPlat-Guan) was prepared to target α-sialosides (components of important antigens such as Sialyl Lewis X). This resulted in strong selective binding of methyla α-sialoside and both the first non-macrocyclic synthetic lectin and the first synthetic lectin with divalency by design. Secondly, a pyrene based four-pillared cage receptor was prepared (Py4P) to target O-linked N-acetylglucosamine (O-GlcNAc). This resulted in a pair of receptor isomers, which demonstrate the highest binding affinities ever obtained by a synthetic lectin for a monosaccharide. It was then also possible to test the interaction of these synthetic lectins with a glycopeptide, which was bound with unprecedented affinity.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Fagla-Amoussou, Akouavi Balbine. "Etude des interactions polluants aromatiques polycycliques (HAP)-récepteurs adrénergiques-phospholipides membranaires dans le tissu adipeux". Thesis, Vandoeuvre-les-Nancy, INPL, 2010. http://www.theses.fr/2010INPL080N/document.

Texto completo

Resumen

L'obésité est une maladie définie par une accumulation de masse grasse dans le tissu adipeux ayant des conséquences néfastes pour la santé. Les causes de l’obésité sont multiples. Dans un travail récent, il y a été démontré le rôle de la pollution environnementale dans la prise de poids. Dans ce travail, les hypothèses selon lesquelles les récepteurs adrénergiques situés à la surface des cellules adipeuses seraient le siège de l’action des polluants aromatiques polycycliques ont été vérifiées par le dosage de plusieurs agonistes et antagonistes spécifiques et non spécifiques en présence ou non du benzo[a]pyrène sur des récepteurs humains et de cellules d’hamster chinois (CHO). Les quantités d’AMPc obtenues montrent que les HAP ne se déposent pas sur les récepteurs β1, β2, β3 adrénergiques.Cette accumulation se fait au niveau des phospholipides de la membrane cytoplasmique des cellules. Ce qui cause une rigidité des membranes.Cette observation tend à renforcer l'hypothèse selon laquelle le benzo[a]pyrène induirait une inhibition de la lipolyse par l'accumulation au niveau de la bicouche de phospholipides et des changements de conformation de la bicouche de phospholipides dans les environs des récepteurs à sept domaines transmembranaires qui sont β-adrénergiques.La liaison de la bicouche phospholipidique avec les HAP utilisés est une réaction exothermi-que avec un faible dégagement de chaleur
Obesity is a disease defined by an accumulation of fat in adipose tissue with adverse consequences for health. The causes of obesity are many.In recent work, there was demonstrated the role of environmental pollution in weight gain.In this work, the assumptions that the adrenergic receptors on the surface of fat cells would home to the accumulation of polycyclic aromatic pollutants have been verified by measurement of several agonists and antagonists specific and non-specific in the presence or absence of benzo[a]pyrene receptors on human cells and Chinese hamster (CHO). The amounts of cAMP obtained showed that PAHs are not deposited on β-receptors, β1, β2, β3 adrenergic receptors.This accumulation occurs at the cytoplasmic membrane phospholipids of the cells. What cau-ses stiffness of the membranes. This observation tends to reinforce the hypothesis that benzo [a]pyrene induce an inhibition of lipolysis by the accumulation in the phospholipid bilayer and conformational changes of the bilayer phospholipids in the vicinity of receptors seven transmembrane domains which are β-adrenergic receptors

Los estilos APA, Harvard, Vancouver, ISO, etc.

Boateng, Stephen. "Photophysical properties of pyrene, 2,7 diazapyrene and 1,3-bis(β-naphthyl)propane". Thesis, University of North Texas, 2007. https://digital.library.unt.edu/ark:/67531/metadc3999/.

Texto completo

Resumen

The luminescence properties of Van Der Waals' dimers and clusters of pyrene and diazapyrene have been investigated. Excimers, dimeric species which are associative in an excited electronic state and dissociative in their ground state, have long been established and play an important role in many areas of photochemistry. My work here focuses on the luminescence and absorption properties of ground state dimers/aggregates, which are less understood, and allows further characterization of the ground state and excited state association of these aromatic molecules.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Chercka, Dennis [Verfasser]. "Pyrene derivatives as donors and acceptors / Dennis Chercka". Mainz : Universitätsbibliothek Mainz, 2015. http://d-nb.info/1069521256/34.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Más fuentes

Libros sobre el tema "Pyrene"

Associates, Clement. Toxicological profile for benzo[a]pyrene. [Atlanta, Ga.]: U.S. Department of Health & Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry, 1990.

Buscar texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Brady, Carolyn. Uptake and metabolism of benzo (a) pyrene by Plantago Lanceolata. [Derby: University of Derby], 2002.

Buscar texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

T, Crosby N., ed. Benzopyrenes. Cambridge [Cambridgeshire]: Cambridge University Press, 1987.

Buscar texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

White, Jerry D. Emission rates of carbon monoxide, particulate matter, and benzo(a)pyrene from prescribed burning of fine southern fuels. [Asheville, N.C.]: U.S. Dept. of Agriculture, Forest Service, Southeastern Forest Experiment Station, 1987.

Buscar texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Britain), Energy Institute (Great y Great Britain Environment Agency, eds. Ambient monitoring of benzo-a-pyrene (B[a]P) emissions at two oil refineries: Energy Institute research report. London: Energy Institute Press, 2008.

Buscar texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Buscar texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Kasapinovic, Sonja. Evaluation of phenytoin and benzo[a]pyrene embryotoxicity using inducible nitric oxide synthase (iNOS) knockout mice in embryo culture. Ottawa: National Library of Canada, 2001.

Buscar texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

The Pyrenean trail GR10: Coast to coast across the French Pyrenees. Milnthorpe: Cicerone Press, 1990.

Buscar texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Marchal, Michel. Les Jardins de Pyrène. Tarbes: Bibliothèque centrale de prêt, 1986.

Buscar texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Greig, David. Pyrenees. London: Faber and Faber, 2005.

Buscar texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Más fuentes

Capítulos de libros sobre el tema "Pyrene"

Lehrer, S. S. y Y. Ishii. "Intramolecular Excimer Fluorescence of Pyrene Maleimide-Labeled Dithiothreitol (Pyrene-DTT)". En Fluorescent Biomolecules, 423–25. Boston, MA: Springer US, 1989. http://dx.doi.org/10.1007/978-1-4684-5619-6_40.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Winkelmann, J. "Diffusion of pyrene (1); air (2)". En Gases in Gases, Liquids and their Mixtures, 1253. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-49718-9_930.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Winkelmann, Jochen. "Diffusion coefficient of pyrene in hexane". En Diffusion in Gases, Liquids and Electrolytes, 1080. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-540-73735-3_856.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Winkelmann, Jochen. "Diffusion coefficient of pyrene in hexadecane". En Diffusion in Gases, Liquids and Electrolytes, 1081. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-540-73735-3_857.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Winkelmann, Jochen. "Diffusion coefficient of pyrene in water". En Diffusion in Gases, Liquids and Electrolytes, 1083. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-540-73735-3_859.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Winkelmann, Jochen. "Diffusion coefficient of pyrene in hexane". En Diffusion in Gases, Liquids and Electrolytes, 1565. Berlin, Heidelberg: Springer Berlin Heidelberg, 2018. http://dx.doi.org/10.1007/978-3-662-54089-3_1074.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Ross, David S., Georgina P. Hum y Robert J. Schmitt. "Nitration of Pyrene by NO2and N2O4". En Advances in Chemistry, 155–68. Washington, DC: American Chemical Society, 1987. http://dx.doi.org/10.1021/ba-1988-0217.ch009.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Vekshin, Nikolai L. "Pyrene Monomers and Excimers in Membranes". En Photonics of Biopolymers, 165–71. Berlin, Heidelberg: Springer Berlin Heidelberg, 2002. http://dx.doi.org/10.1007/978-3-662-04947-1_16.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Noordkamp, E. R., J. T. C. Grotenhuis y W. H. Rulkens. "Optimal Process Conditions for Extraction of Pyrene and Benzo(A)Pyrene from Soil with Organic Solvents". En Contaminated Soil ’95, 1317–18. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-0421-0_131.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Winkelmann, J. "Diffusion of pyrene (1); carbon dioxide (2)". En Gases in Gases, Liquids and their Mixtures, 1756. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-49718-9_1332.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Actas de conferencias sobre el tema "Pyrene"

Ariese, Freek, S. J. Kok, M. Verkaik, Gerard P. Hoornweg, Cees Gooijer, Nel H. Velthorst y Johannes W. Hofstraat. "Monitoring benzo(a)pyrene exposure using laser-excited Shpol'skii spectroscopy of benzo(a)pyrene metabolites". En Environmental Sensing '92, editado por Tuan Vo-Dinh y Karl Cammann. SPIE, 1993. http://dx.doi.org/10.1117/12.140258.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Talaska, G., B. Schumann y K. LaDow. "53.1. Kerosene and Pyrene Alter Dna Adduct Levels in Mice Treated Topically with Benzo(A)Pyrene". En AIHce 2002. AIHA, 2002. http://dx.doi.org/10.3320/1.2766404.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Salazar, V., J. E. Gonza´lez y L. A. Rivera. "Measurement of Temperatures on In-Flight Water Droplets by Laser Induced Fluorescence Thermometry". En ASME 2003 Heat Transfer Summer Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/ht2003-47100.

Texto completo

Resumen

This work presents the use of laser induced fluorescence for instantaneous temperature measurements of a 200μm diameter water droplets monodispersed stream traveling downward in a standard stagnant atmosphere. The droplets are doped with small concentrations of a natural fluorescence dye (Pyrene), and with a surfactant substance, cetyldimetylbenzylammoniumchloride (CDBAC) to improve the fluorescence emission. The rate of the two-band pyreme emission (excimer to monomer) is used to determine the temperature. The temperature distribution along the stream of droplets determined for different initial temperatures: (30°C, 40°C and 50°C) at the exit of the nozzle compared very favorably with numerical results.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Sutherland, R. L., V. P. Tondiglia y D. M. Brandelik. "Photochromic Properties Of A Pyrene/Methanol Solution". En 31st Annual Technical Symposium, editado por Carl M. Lampert. SPIE, 1987. http://dx.doi.org/10.1117/12.941887.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Webster, Ian y Michael Duncan. "LASER SYNTHESIS AND SPECTROSCOPY OF PYRENE DIMERS". En 2021 International Symposium on Molecular Spectroscopy. Urbana, Illinois: University of Illinois at Urbana-Champaign, 2021. http://dx.doi.org/10.15278/isms.2021.ff08.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Ribou, Anne-Cecile, Jean Vigo, Pierre M. Viallet y Jean-Marie Salmon. "Oxygen measurement in living cells: comparison between a new vital fluorescent pyrene probe labeling mitochondria and pyrene butyric acid". En International Symposium on Biomedical Optics, editado por Daniel L. Farkas y Robert C. Leif. SPIE, 2002. http://dx.doi.org/10.1117/12.468330.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Shirdel, J., A. Penzkofer, R. Procházka, Z. Shen y J. Daub. "Photodynamics of pyrene-flavin and phenothiazine-flavin dyads". En The International Conference on Coherent and Nonlinear Optics, editado por Sergey A. Tikhomirov, Thomas Udem, Valery Yudin, Maxim Pshenichnikov y Oleg M. Sarkisov. SPIE, 2007. http://dx.doi.org/10.1117/12.752443.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Andrianov, Sergei N., Vitaly V. Samartsev, Nataliya B. Silaeva y Pyotr V. Zinoviev. "Optical superradiance in a crystal of biphenyl with pyrene". En Eighth International Readings on Quantum Optics: IRQO '99, editado por Vitaly V. Samartsev. SPIE, 2000. http://dx.doi.org/10.1117/12.375336.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Qin, Wei, Junfeng Dou, Yi Zhu, Aizhong Ding, Xiang Liu y Jing Yuan. "Characteristics of Anaerobic Benzo(a)pyrene Biodegradation byC. cellulansCWS2". En World Environmental and Water Resources Congress 2016. Reston, VA: American Society of Civil Engineers, 2016. http://dx.doi.org/10.1061/9780784479865.010.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Marinho, P. H. Campos, P. Mendes de Souza, M. A. Barbosa de Lima, A. Elesbão do Nascimento y G. M. Campos Takaki. "Effect of Pyrene on the growth of Rhodotorula sp". En Proceedings of the II International Conference on Environmental, Industrial and Applied Microbiology (BioMicroWorld2007). WORLD SCIENTIFIC, 2009. http://dx.doi.org/10.1142/9789812837554_0046.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Informes sobre el tema "Pyrene"

Netzel, T. L. An exploration of sequence specific DNA-duplex/pyrene interactions for intercalated and surface-associated pyrene species. Technical progress report. Office of Scientific and Technical Information (OSTI), enero de 1994. http://dx.doi.org/10.2172/10145812.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Netzel, T. L. An exploration of sequence specific DNA-duplex/pyrene interactions for intercalated and surface-associated pyrene species. Final report, May 1, 1993--December 31, 1996. Office of Scientific and Technical Information (OSTI), marzo de 1997. http://dx.doi.org/10.2172/548674.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Kaizen Matsumoto, Kaizen Matsumoto. Can perfluorocarbon liquids remove benzo(a)pyrene, a model carcinogen from cells? Experiment, junio de 2015. http://dx.doi.org/10.18258/5352.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Rasmussen, R. E. y A. T. Fong. Metabolism of Benzo(A)Pyrene and Diethylnitrosamine by Lung Cells of Rats, Mice, and Hamsters. Fort Belvoir, VA: Defense Technical Information Center, julio de 1985. http://dx.doi.org/10.21236/ada159383.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Haugen, D. y S. Myers. Reaction of benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide with human hemoglobin and chromatographic resolution of the covalent adducts. Office of Scientific and Technical Information (OSTI), enero de 1990. http://dx.doi.org/10.2172/7244688.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Carlson, E. A., Y. Li y J. T. Zelikoff. Inhibition of CYP1A-Mediated Metabolism of Benzo(A)Pyrene (BAP): Effects Upon BAP-Induced Immunotoxicity in Japanese Medaka (Oryzias Latipes). Fort Belvoir, VA: Defense Technical Information Center, marzo de 2001. http://dx.doi.org/10.21236/ada402076.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Pelletier, Austin, Amanda Hohner, Idil Deniz Akin, Indranil Chowdhury, Richard Watts, Xianming Shi, Brendan Dutmer y James Mueller. Bench-scale Electrochemical Treatment of Co-contaminated Clayey Soil. Illinois Center for Transportation, junio de 2021. http://dx.doi.org/10.36501/0197-9191/21-018.

Texto completo

Resumen

Industrial soil contamination is frequently unearthed by transportation agencies during construction within the right-of-way. As a result, transportation agencies may experience construction delays. Soils co-contaminated with high-molecular-weight polycyclic aromatic hydrocarbons (HMW-PAHs) and metals are commonly encountered in Illinois and exhibit recalcitrance towards conventional treatment technologies. This issue is exacerbated in the fine-grained soils common to Illinois, where low-permeability and immense sorption capacity increase treatment complexity, cost, and duration. Contaminated sites are spatially and temporally restrictive and require rapid in situ treatments, whereas conventional soil remediation requires 1 to 3 years on average. Consequently, transportation agencies typically pursue excavation and off-site disposal for expediency. However, this solution is expensive, so a comparatively expeditious and affordable treatment alternative is needed to combat the increasing cost of hazardous waste disposal. The objective of this work was to develop an accelerated in situ treatment approach adaptable for use at any construction site to cost-effectively remove HMW-PAHs and metals from clayey soil. It was hypothesized that an in situ electrochemical treatment which augments electrokinetics with H2O2 could remediate both HMW-PAHs and metals in less than a month. Bench-scale reactors resemblant of field-scale in situ electrokinetic systems were designed and fabricated to assess the electrochemical treatment of clayey soils contaminated with HMW-PAHs and metals. Pyrene, chromium, and manganese were used as model contaminants, spiked into kaolinite as a model clay. Electrokinetics were imposed by a low-intensity electrical field distributed by graphite rods. Electrolytic H2O2 systems were leveraged to distribute electrical current and facilitate contaminant removal. Average contaminant removals of 100%, 42.3%, and 4.5% were achieved for pyrene, manganese, and chromium, respectively. Successful development of this bench-scale treatment approach will serve to guide transportation agencies in field-scale implementation. The results from this work signify that electrochemical systems that leverage eco-friendly oxidant addition can replace excavation and disposal as a means of addressing clayey soils co-contaminated with HMW-PAHs and metals.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Komppula, Birgitta, Tomi Karppinen, Henrik Virta, Anu-Maija Sundström, Iolanda Ialongo, Kaisa Korpi, Pia Anttila, Jatta Salmi, Johanna Tamminen y Katja Lovén. Air quality in Finland according to air quality measurements and satellite observations. Finnish Meteorological Institute, septiembre de 2021. http://dx.doi.org/10.35614/isbn.9789523361409.

Texto completo

Resumen

In this report the current air quality in Finland has been assessed with air quality measurement data and satellite observations. The assessment of ambient air concentrations included following air impurities: NO2, NOx, PM10, PM2,5, SO2, CO, O3, benzo(a)pyrene, benzene, Pb, As, Cd ja Ni. For these pollutants air quality assessment thresholds are given in air quality legislation (2008/50/EY, 2004/107/EY). Assessment has been performed for air quality zones. The main data set included air quality measurements performed in Finland during 2015–2019. Satellite observations were used as an objective assessment tool in analysis of the spatial variation of NO2 and CO concentrations. Air quality measurements show that air quality has improved in Finland in many respects. Especially the need to monitor NO2 and PM10 with continuous measurements has decreased. Growing understanding of national benzo(a)pyrene concentrations has increased the monitoring needs. Efforts to decrease ozone levels still requires international actions. SO2, CO, benzene and heavy metal concentrations are on a low level in Finland outside industrial areas and other assessment methods than continuous monitoring can be used, and the number of continuous monitoring sites has already decreased. Satellite-based concentrations of nitrogen dioxide and carbon monoxide as well as their spatial variation in Finland were analyzed using observations from the TROPOsperic Monitoring Instrument (TROPOMI). The analysis of CO over Finland was carried out for the first time in this project. Results show that overall annual CO concentrations over Finland are low and spatial variability is small. Also, NO2 concentrations over Finland are rather low, but spatial patterns are more clearly visible. The highest NO2 concentrations are observed over the largest cities. By establishing a relationship between ground-based and satellite total column concentrations, surface concentrations of NO2 and CO were estimated from the satellite data for the zones. The satellite-based estimate for annual NO2 surface concentration over Helsinki metropolitan area is 28 μg/m3, and for the rest of Finland mostly between 10–15 μg/m3. For CO the differences between monitoring areas are small, with estimates varying between 160–164 μg/m3 or in other words about 0,16 mg/m3.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Padget, C. D. W., D. R. M. Pattison, D. P. Moynihan y O. Beyssac. Pyrite and pyrrhotite in a prograde metamorphic sequence, Hyland River region, SE Yukon: implications for orogenic gold. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/328987.

Texto completo

Resumen

The distribution of pyrite and pyrrhotite is documented within an andalusite-sillimanite type (high-temperature, low-pressure) metasedimentary succession exposed in the Hyland River region of southeastern Yukon, Canada. The following metamorphic zones are recognized: chlorite, biotite, cordierite/staurolite (porphyroblast-in), andalusite, sillimanite, and K-feldspar + sillimanite. Pyrite occurs in the chlorite zone through the biotite zone, while pyrrhotite occurs from the chlorite zone to K-feldspar + sillimanite zone. The pyrite-pyrrhotite transition, therefore, occupies an interval in the chlorite and lower biotite zones that is terminated upgrade by a pyrite-out isograd in the upper part of the biotite zone or lowest grade part of the cordierite/staurolite zone. Pressure and temperature conditions of the rocks were estimated from phase equilibrium modelling and from Raman spectroscopy of carbonaceous material (RSCM) thermometry. Modelling indicates pressures of 3.7-4.1 kbar with temperatures of ~425 °C at the biotite isograd, 560-570 °C for chlorite-out/porphyroblast-in, ~575 °C for andalusite-in, 575-600 °C for the sillimanite isograd, and 645-660 °C at the K-feldspar + sillimanite isograd. RSCM temperatures are greater than or equal to 420 °C in the Chl zone, 500 °C at the Bt isograd, 525-550 °C for porphyroblast-in isograd, ~550 °C at the And isograd, and 580 °C at the Sil isograd. These results suggest the pyrite-pyrrhotite transition occurs from less than or equal to 420°C to ~560 °C. Thermodynamic modelling shows 0.6 wt. % H2O is released during metamorphism over the ~140 °C interval of the pyrite-pyrrhotite transition. The gradual release of fluid in the biotite zone is interpreted to have broadened the pyrite-pyrrhotite transition compared to other studies that predict a small interval of vigorous fluid release associated with volumetric chlorite consumption. Samples from the pyrite-pyrrhotite transition zone contain lower whole rock and pyrite Au values than samples from unmetamorphosed/lower rocks, suggesting that Au was removed from the rock at conditions below the pyrite-pyrrhotite transition (&lt;420 °C). The chlorite zone and higher-grade metamorphic rocks of the Hyland River area do not appear to be a plausible source region for orogenic gold.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Neyedley, K., J. J. Hanley, P. Mercier-Langevin y M. Fayek. Ore mineralogy, pyrite chemistry, and S isotope systematics of magmatic-hydrothermal Au mineralization associated with the Mooshla Intrusive Complex (MIC), Doyon-Bousquet-LaRonde mining camp, Abitibi greenstone belt, Québec. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/328985.

Texto completo

Resumen

The Mooshla Intrusive Complex (MIC) is an Archean polyphase magmatic body located in the Doyon-Bousquet-LaRonde (DBL) mining camp of the Abitibi greenstone belt, Québec. The MIC is spatially associated with numerous gold (Au)-rich VMS, epizonal 'intrusion-related' Au-Cu vein systems, and shear zone-hosted (orogenic?) Au deposits. To elucidate genetic links between deposits and the MIC, mineralized samples from two of the epizonal 'intrusion-related' Au-Cu vein systems (Doyon and Grand Duc Au-Cu) have been characterized using a variety of analytical techniques. Preliminary results indicate gold (as electrum) from both deposits occurs relatively late in the systems as it is primarily observed along fractures in pyrite and gangue minerals. At Grand Duc gold appears to have formed syn- to post-crystallization relative to base metal sulphides (e.g. chalcopyrite, sphalerite, pyrrhotite), whereas base metal sulphides at Doyon are relatively rare. The accessory ore mineral assemblage at Doyon is relatively simple compared to Grand Duc, consisting of petzite (Ag3AuTe2), calaverite (AuTe2), and hessite (Ag2Te), while accessory ore minerals at Grand Duc are comprised of tellurobismuthite (Bi2Te3), volynskite (AgBiTe2), native Te, tsumoite (BiTe) or tetradymite (Bi2Te2S), altaite (PbTe), petzite, calaverite, and hessite. Pyrite trace element distribution maps from representative pyrite grains from Doyon and Grand Duc were collected and confirm petrographic observations that Au occurs relatively late. Pyrite from Doyon appears to have been initially trace-element poor, then became enriched in As, followed by the ore metal stage consisting of Au-Ag-Te-Bi-Pb-Cu enrichment and lastly a Co-Ni-Se(?) stage enrichment. Grand Duc pyrite is more complex with initial enrichments in Co-Se-As (Stage 1) followed by an increase in As-Co(?) concentrations (Stage 2). The ore metal stage (Stage 3) is indicated by another increase in As coupled with Au-Ag-Bi-Te-Sb-Pb-Ni-Cu-Zn-Sn-Cd-In enrichment. The final stage of pyrite growth (Stage 4) is represented by the same element assemblage as Stage 3 but at lower concentrations. Preliminary sulphur isotope data from Grand Duc indicates pyrite, pyrrhotite, and chalcopyrite all have similar delta-34S values (~1.5 � 1 permille) with no core-to-rim variations. Pyrite from Doyon has slightly higher delta-34S values (~2.5 � 1 permille) compared to Grand Duc but similarly does not show much core-to-rim variation. At Grand Duc, the occurrence of Au concentrating along the rim of pyrite grains and associated with an enrichment in As and other metals (Sb-Ag-Bi-Te) shares similarities with porphyry and epithermal deposits, and the overall metal association of Au with Te and Bi is a hallmark of other intrusion-related gold systems. The occurrence of the ore metal-rich rims on pyrite from Grand Duc could be related to fluid boiling which results in the destabilization of gold-bearing aqueous complexes. Pyrite from Doyon does not show this inferred boiling texture but shares characteristics of dissolution-reprecipitation processes, where metals in the pyrite lattice are dissolved and then reconcentrated into discrete mineral phases that commonly precipitate in voids and fractures created during pyrite dissolution.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Ofrecemos descuentos en todos los planes premium para autores cuyas obras están incluidas en selecciones literarias temáticas. ¡Contáctenos para obtener un código promocional único!