Journal articles on the topic 'Milieux sulfurés'
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1
THILL, C., E. MONTELESCAUT, P. ARIES, J. SAPIN-LORY, M. OULD-AHMED, and I. DROUILLARD. "Intoxication à l’hydrogène sulfuré : revue de la littérature et implications en milieu militaire." Médecine et Armées Vol. 42 No. 2, Volume 42, Numéro 2 (April 1, 2014): 185–92. http://dx.doi.org/10.17184/eac.6993.
Abstract:
L’intoxication à l’hydrogène sulfuré (H2S) constitue un risque réel au sein des forces armées et notamment de la Marine, qui se doit d’être connu par les praticiens. L’objectif de cet article est de passer en revue les caractéristiques physicochimiques d’H2S, les différentes formes cliniques de l’intoxication et les prises en charge para-cliniques et thérapeutiques. Enfin, les aspects propres au milieu militaire en matière de détection et de prévention sont exposés ainsi que les situations à risque.
2
Nfissi, Samiha, Saida Alikouss, Youssef Zerhouni, Zouhir Baroudi, and Mohamed Samir. "Alkaline amendment based of sludge pulp of sweets and clays: application to the tailings of the abandoned kettara mine (Morocco)." Annales de la Société Géologique du Nord, no. 25 (December 1, 2018): 75–81. http://dx.doi.org/10.54563/asgn.637.
Abstract:
Les rejets miniers sulfurés de la mine de Kettara (région de Marrakech) sont entreposés sur un socle schisteux très fracturé sur une superficie d’environ 16 hectares. Dans ce site, plus de 3 millions de tonnes de résidus sont stockés sur le sol sans aucune contrariété de leurs impacts sur l’environnement. Les minéraux acidogènes composant ces rejets, sous l’action de l’eau et de l’oxygène, génèrent du Drainage Minier Acide (DMA). Ce phénomène entraîne une acidité du milieu qui provoque la destruction de la flore et de la faune ainsi que la contamination des eaux souterraines. Ces rejets solides à fortes concentrations en métaux (As, Pb, Fe, Cu…), produisent des lixiviats très acides (pH ≤ 3) entrainant la solubilisation des sulfures et la libération des métaux toxiques qui polluent les ressources hydriques de la région. Afin d’atténuer le DMA à Kettara, un protocole d’amendement alcalin a été testé au laboratoire en utilisant les boues de pâte de sucrerie (Sludge Pulp of Sweets : SPS) et des argiles (Clays : Clys). Les matériaux choisis ont fait l’objet d’une caractérisation physico-chimique et minéralogique puis d’une série d’essais de lixiviation en mini-cellules d’altération. Ces essais ont montré que les pH des SPS et des Clys varient respectivement entre 6,1 et 8,5 et entre 6,7 et 9. Le potentiel neutralisant de ces matériaux, déterminé par la méthode Acid-Base Accounting, est de l’ordre de 878,5 Kg CaCO3/t pour les SPS et de 299 Kg CaCO3/t pour les Clys. Ces matériaux fins et alcalins ont donc un potentiel neutralisant assez élevé susceptible de réduire considérablement le DMA. Les SPS et des Clys, au vue de leur potentiel de neutralisation et leurs propriétés physico-chimiques, constitueraient d’excellents matériaux de base pour un amendement visant l’atténuation du DMA dans la mine abandonnée de Kettara.
3
Duffó, G. S., and J. R. Collet-Lacoste. "Effet du sulfure d’hydrogène sur l’entrée de l’hydrogène dans les aciers ferritiques en milieux acide." Revue de Métallurgie 94, no. 2 (February 1997): 249–58. http://dx.doi.org/10.1051/metal/199794020249.
4
Kua, Jeremy, and Nicole A. Miller. "Preliminary Free Energy Map of Prebiotic Compounds Formed from CO2, H2 and H2S." Life 12, no. 11 (November 2, 2022): 1763. http://dx.doi.org/10.3390/life12111763.
Abstract:
What kinds of CHOS compounds might be formed in a prebiotic milieu by reducing CO2 in the presence of H2 and H2S? How might the presence of sulfur influence the chemical composition of the mixture? We explore these questions by using first-principles quantum chemistry to calculate the free energies of CHOS compounds in aqueous solution, by first generating a thermodynamic map of one- and two-carbon species. We find that while thiols are thermodynamically favored, thioesters, thioacids, and thiones are less favorable than their non-sulfur counterparts. We then focus on the key role played by mercaptoacetaldehyde in sulfur analogs of the autocatalytic formose reaction, whereby the thiol group introduces asymmetry and potential thermodynamic selectivity of some compounds over others.
5
Aboulhassan, Moulay Abdelazize, Salah Souabi, Abdelrani Yaacoubi, Nourredine Zaim, and Fatima Zohra Bouthir. "Les effluents de tannerie caractérisation et impact sur le milieu marin." Revue des sciences de l'eau 21, no. 4 (October 20, 2008): 463–73. http://dx.doi.org/10.7202/019168ar.
Abstract:
Résumé Dans ce travail, nous avons caractérisé et évalué l’impact sur le milieu marin des rejets industriels de tannerie. Les résultats montrent que la qualité des eaux usées varie considérablement d’une étape de production à l’autre. Les opérations de prétannage (travail de rivière) sont les plus polluantes avec des teneurs en DCO qui peuvent atteindre 30 000 mg/L. L’analyse des eaux usées au niveau du bassin de collecte, où s’achemine l’ensemble des effluents de l’usine, montre une charge polluante importante et variable avec le temps. La DCO fluctue entre 700 et 3 400 mg/L et les matières en suspension entre 500 et 8 000 mg/L avec des charges polluantes moyennes de 114 et 358 kg/jour respectivement. Ces eaux sont aussi chargées en chrome avec des teneurs qui se situent entre 40 et 115 mg/L, soit une charge de 6,5 kg/jour. La teneur en sulfures varie entre 65 et 160 mg/L. En outre, l’indice de biodégradabilité (DBO5/DCO : 0.1 – 0.2) indique que ce rejet n’est pas facilement biodégradable. L’examen des teneurs en chrome chez des espèces bioindicatrices, la moule Mytilus galloprovincialis et les algues Ulva lactuca et Corallina officinalis, montre l’ampleur des apports en polluants causée par ce type de rejets au niveau de la mer. Les teneurs en chrome au niveau de ces espèces à proximité de point du déversement de ces eaux usées, sont élevées comparées à d’autres points plus éloignés.
6
Ader, Magali, and Marc Javoy. "Diagenese précoce en milieu sulfuré réducteur une étude isotopique dans le Jurassique basai du Bassin parisien." Comptes Rendus de l'Académie des Sciences - Series IIA - Earth and Planetary Science 327, no. 12 (December 1998): 803–9. http://dx.doi.org/10.1016/s1251-8050(99)80054-8.
7
Bellaouchou, A., A. Guenbour, A. Ben Bachir, L. Aries, and F. Dabosi. "Alliage 904 L : comportement électrochimique en milieux phosphoriques pollués par les ions sulfures et fluorures en condition de corrosion-abrasion." Matériaux & Techniques 86, no. 9-10 (1998): 21–29. http://dx.doi.org/10.1051/mattech/199886090021.
8
Teigen, Levi M., Zhuo Geng, Michael J. Sadowsky, Byron P. Vaughn, Matthew J. Hamilton, and Alexander Khoruts. "Dietary Factors in Sulfur Metabolism and Pathogenesis of Ulcerative Colitis." Nutrients 11, no. 4 (April 25, 2019): 931. http://dx.doi.org/10.3390/nu11040931.
Abstract:
The biogeography of inflammation in ulcerative colitis (UC) suggests a proximal to distal concentration gradient of a toxin. Hydrogen sulfide (H2S) has long been considered one such toxin candidate, and dietary sulfur along with the abundance of sulfate reducing bacteria (SRB) were considered the primary determinants of H2S production and clinical course of UC. The metabolic milieu in the lumen of the colon, however, is the result of a multitude of factors beyond dietary sulfur intake and SRB abundance. Here we present an updated formulation of the H2S toxin hypothesis for UC pathogenesis, which strives to incorporate the interdependency of diet composition and the metabolic activity of the entire colon microbial community. Specifically, we suggest that the increasing severity of inflammation along the proximal-to-distal axis in UC is due to the dilution of beneficial factors, concentration of toxic factors, and changing detoxification capacity of the host, all of which are intimately linked to the nutrient flow from the diet.
9
Maujean, Alain. "The chemistry of sulphur in musts and wines." OENO One 35, no. 4 (December 31, 2001): 171. http://dx.doi.org/10.20870/oeno-one.2001.35.4.1698.
Abstract:
<p style="text-align: justify;">L'auteur de cet article de synthèse sur les origines et le comportement chimique du soufre et de ses principaux dérivés dans le milieu du vin a voulu montrer que la « chimie » peut être un outil utile pour une meilleure compréhension de phénomènes physico-chimiques s'opérant dans les vins. Une telle démarche permet de mieux en prévoir leur évolution.</p><p style="text-align: justify;">Il ressort de cette étude que la réactivité chimique des deux dérivés principaux de l'atome de soufre, à savoir l'anhydride sulfureux et le sulfure d'hydrogène à eux seuls, explique, en partie au moins, l'origine et la présence de nombreux autres produits soufrés ainsi que les caractéristiques organoleptiques d'un vin selon leurs concentrations.</p>
10
Ferdinand, Yao Diby, Assale Fori Jean Paul, Alla Amani Jonas, and Digbehi Zeli Bruno. "Caracterisasion Geochimique des Deblais du Substratum de la Baie du Banco, Abidjan, Basse Cote d‘Ivoire." European Scientific Journal, ESJ 19, no. 36 (December 31, 2023): 124. http://dx.doi.org/10.19044/esj.2023.v19n36p124.
Abstract:
L’étude géochimique réalisée s’est éffectuée sur les déblais du substratum de la baie du Banco situé au Sud-est du bassin sédimentaire côtier de la Côte d’Ivoire. Cette étude vise à caractériser le substratum de la baie du Banco à partir des éléments chimiques ainsi que la détermination des paléoconditions des environnements de dépôt. La spectrométrie par fluorescence à rayon x (XRF) a permis de déterminer les éléments majeurs ainsi que des éléments traces présents dans les lutites noirâtres du substratum de la baie. Les éléments majeurs identifiés sont par ordre décroissant le Silicium (45,33 %), le Fer (35,56 %), l’Aluminium (9,24 %), le Potassium (2,31 %), le Calcium (2,22 %), le Titane (2 ,15 %), le Chlore (2,04 %) et le Phosphore (1,12 %). L’analyse géostatistique a permis de mettre en évidence de fortes corrélations entre la matière organique et le fer réduit (Fe 2+), l’étain (Sn), l’arsenic (As) et le soufre (S). Le substratum de la baie du Banco est caractérisé par une forte concentration en soufre variant de 12475 à 75752 ppm et une bioproductivité primaire plus importante en profondeur qu’en surface. Les éléments traces U, V et Mo ont permis d’identifier un milieu euxinique à interface eau-sédiment en subsurface du substratum (0- 32 m) tandis qu’en fin de forage (78-80 m), on distingue un milieu suboxique à anoxique. Ces différents résultats ont permis de caractériser le substratum de la baie du Banco.
The geochemical study was carried out on cuttings from the Banco Bay bedrock in the southeastern part of the Côte d'Ivoire coastal sedimentary basin. The study aimed to characterize the Banco Bay bedrock based on chemical elements and to determine the paleo conditions of the depositional environments. X-ray fluorescence spectrometry (XRF) was used to determine the major and trace elements present in the blackish lutites of the bay bedrock. The major elements identified were, in descending order, Silicon (45.33%), Iron (35.56%), Aluminium (9.24%), Potassium (2.31%), Calcium (2.22%), Titanium (2.15%), Chlorine (2.04%) and Phosphorus (1.12%). Geostatistical analysis revealed strong correlations between organic matter and reduced iron (Fe 2+), tin (Sn), arsenic (As), and sulfur (S). The Banco Bay bedrock is characterized by high sulfur concentrations ranging from 12475 to 75752 ppm, and higher primary bioproductivity at depth than at the surface. Trace elements U, V, and Mo identified an euxinic environment at the water-sediment interface in the subsurface of the bedrock (0-32 m), while at the end of the borehole (78-80 m), a suboxic to anoxic environment was distinguished. These results have enabled us to characterize the bedrock of the Banco Bay.
11
Biaise, C., and G. Costan. "La toxicité léthale aiguë des effluents industriels au Québec vis-à-vis de la truite arc-en-ciel." Water Quality Research Journal 22, no. 3 (August 1, 1987): 385–402. http://dx.doi.org/10.2166/wqrj.1987.030.
Abstract:
Abstract De 1975 à 1984, plus de 300 échantillons d’effluents industriels provenant de 160 sites industriels de la province de Québec ont été bioanalysés afin d’évaluer leur toxicité létale aiguë envers la truite arc-en-ciel. Six secteurs industriels étaient représentés par ces prélèvements: Pâtes et Papiers (PP) , Minier (M), Chimique (C), Alimentaire (A), Raffineries (R), Textiles (T). Diverses façons d’analyser les données ont permis de dégager d’intéressantes informations liées à leurs toxicités respectives. Tout d’abord, le groupe PP, A et T est apparu globalement plus toxique que le groupe C, M et R. De plus, quatre secteurs ont démontré une ressemblance marquée au niveau de leur expression toxique (i.e. CL50-96 h), soit le secteur PP avec le secteur A et le secteur M avec le secteur R. Par ailleurs, l’étude des données de TL50 a indiqué que de 6 S 20% de ceux-ci (selon le secteur) sont atteints au delà de 24 h d’exposition. Ce constat plaide en faveur de la réalisation de CL50 de 96 h afin de ne pas sous-estimer les effets toxiques. D’autre part, des CL50 aussi basses que 1 v/v % (nos données) et 0,1 v/v % (données rapportées ailleurs) ont été obtenues pour des effluents finaux rejetés dans le milieu aquatique. Enfin, une analyse plus poussée de 23 effluents finaux du secteur PP n’ayant subi aucun traitement a permis de relier leur toxicité à certains paramètres physico-chimiques (sulfures, Mn, DCO, solides totaux, phénols) analysés en support aux bioanalyses.
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Dohou, Alfred Dèdonougbo, Koto Gabin N’Gobi, Clément Adéyèmi Kouchade, and Basile Bruno Kounouhewa. "Evaluation du pouvoir methanogene de la jacinthe d’eau sur le Lac Nokoue à Ganvie au Benin." Journal de Physique de la SOAPHYS 2, no. 2 (May 12, 2021): C20A23–1—C20A23–5. http://dx.doi.org/10.46411/jpsoaphys.2020.02.23.
Abstract:
La jacinthe d’eau (Eichornia crassipes) est une plante aquatique invasive. Elle est devenue un véritable fléau dans les eaux du monde entier en générale et dans les eaux du lac Nokoué en particulier rendant difficile la navigation aux usagers locaux de la plus grande cité lacustre du Bénin. Devant cette urgence, nous pensons que la biomasse lignocellulosique issue de l’exploitation de la jacinthe peut constituer une voie prometteuse permettant son utilisation comme matière première pour la production du bio méthane. De plus, l’urgence de trouver d’autres sources d’énergie énergies renouvelables suite à l’amenuisement des énergies fossiles n’est plus à démontrer. L’objectif de notre travail est d’évaluer le pouvoir méthanogène de la jacinthe d’eau prélevée sur le lac Nokoué à Ganvié dans la commune de So-Ava au Bénin. Ainsi, nous avons introduit à titre expérimental, dans un bidon de 25litres, 150g de jacinthe d’eau hachée avec 1litre d’inoculum. Après 40 jours de fermentation, il a été produit 5169,025 ml de méthane ou 34,46 ml/g CH4 soit 58% du volume total de biogaz produit. Le taux du sulfure d’hydrogène remarqué dans le biogaz produit permet de conclure que la concentration en soufre ou en ses dérivés dans l’eau du lac Nokoué est importante. La jacinthe d’eau (Eichornia crassipes) peut être un bon substrat pour la bio méthanisation anaérobie en milieu lacustre.
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Lion, Claude, Louis da Conceição, Gerard Hecquet, Christian Pralus, Jean-Pierre Schirmann, and Benoît Requieme. "OXYDATION ALCALINE PAR L'ACIDE PERPROPIONIQUE D'ARYL MÉTHYL SULFURES EN SULFOXYDES. ETUDES EXPÉRIMENTALES ET THÉORIQUES DE L'OXYDATION NUCLÉOPHILE DE DÉRIVÉSP-SUBSTITUÉS DU THIOANISOLE PAR L'ANION PERPROPIONATE EN MILIEU MICELLAIRE." Phosphorus, Sulfur, and Silicon and the Related Elements 179, no. 6 (June 2004): 1131–52. http://dx.doi.org/10.1080/10426500490459740.
14
Hajji, M. "Influence des chlorures et des sulfures sur la corrosion des alliages inoxydables en milieu phosphoriqueInfluence of chlorides and sulfides on the corrosion of stainless alloys in a phosphoric medium." Annales de Chimie Science des Matériaux 27, no. 4 (August 2002): 27–38. http://dx.doi.org/10.1016/s0151-9107(02)80016-2.
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Tolbatov, Iogann, Alessandro Marrone, Cecilia Coletti, and Nazzareno Re. "Computational Studies of Au(I) and Au(III) Anticancer MetalLodrugs: A Survey." Molecules 26, no. 24 (December 15, 2021): 7600. http://dx.doi.org/10.3390/molecules26247600.
Abstract:
Owing to the growing hardware capabilities and the enhancing efficacy of computational methodologies, computational chemistry approaches have constantly become more important in the development of novel anticancer metallodrugs. Besides traditional Pt-based drugs, inorganic and organometallic complexes of other transition metals are showing increasing potential in the treatment of cancer. Among them, Au(I)- and Au(III)-based compounds are promising candidates due to the strong affinity of Au(I) cations to cysteine and selenocysteine side chains of the protein residues and to Au(III) complexes being more labile and prone to the reduction to either Au(I) or Au(0) in the physiological milieu. A correct prediction of metal complexes’ properties and of their bonding interactions with potential ligands requires QM computations, usually at the ab initio or DFT level. However, MM, MD, and docking approaches can also give useful information on their binding site on large biomolecular targets, such as proteins or DNA, provided a careful parametrization of the metal force field is employed. In this review, we provide an overview of the recent computational studies of Au(I) and Au(III) antitumor compounds and of their interactions with biomolecular targets, such as sulfur- and selenium-containing enzymes, like glutathione reductases, glutathione peroxidase, glutathione-S-transferase, cysteine protease, thioredoxin reductase and poly (ADP-ribose) polymerase 1.
16
Fujii, Junichi, Tsukasa Osaki, Yuya Soma, and Yumi Matsuda. "Critical Roles of the Cysteine–Glutathione Axis in the Production of γ-Glutamyl Peptides in the Nervous System." International Journal of Molecular Sciences 24, no. 9 (April 28, 2023): 8044. http://dx.doi.org/10.3390/ijms24098044.
Abstract:
γ-Glutamyl moiety that is attached to the cysteine (Cys) residue in glutathione (GSH) protects it from peptidase-mediated degradation. The sulfhydryl group of the Cys residue represents most of the functions of GSH, which include electron donation to peroxidases, protection of reactive sulfhydryl in proteins via glutaredoxin, and glutathione conjugation of xenobiotics, whereas Cys-derived sulfur is also a pivotal component of some redox-responsive molecules. The amount of Cys that is available tends to restrict the capacity of GSH synthesis. In in vitro systems, cystine is the major form in the extracellular milieu, and a specific cystine transporter, xCT, is essential for survival in most lines of cells and in many primary cultivated cells as well. A reduction in the supply of Cys causes GPX4 to be inhibited due to insufficient GSH synthesis, which leads to iron-dependent necrotic cell death, ferroptosis. Cells generally cannot take up GSH without the removal of γ-glutamyl moiety by γ-glutamyl transferase (GGT) on the cell surface. Meanwhile, the Cys–GSH axis is essentially common to certain types of cells; primarily, neuronal cells that contain a unique metabolic system for intercellular communication concerning γ-glutamyl peptides. After a general description of metabolic processes concerning the Cys–GSH axis, we provide an overview and discuss the significance of GSH-related compounds in the nervous system.
17
Martineu, Pascale, and S. Kim Juniper. "Comparison of the benzyl viologen and bimane HPLC assays for the determination of sulfide-oxidizing capability in the tissues of hydrothermal vent and non-vent polychaetes." Canadian Journal of Zoology 75, no. 10 (October 1, 1997): 1618–27. http://dx.doi.org/10.1139/z97-788.
Abstract:
Two commonly used methods for in vitro measurement of tissue-level sulfide oxidation in animals were compared using homogenates of hydrothermal vent (Paralvinella sulfincola and P. palmiformis) and non-vent (Nereis virens and Nephtys caeca) polychaetes. All examined worms showed heat-labile sulfide-oxidizing ability and rates were slightly higher in the two vent species. A previously observed discrepancy between the results of the spectrophotometric benzyl viologen (BV) and bimane high-performance liquid chromatography (HPLC) assays was confirmed. We explain this discrepancy firstly by the fact that H2S removal measured by the bimane HPLC assay is only the first step in a cascade of several possible sulfur-oxidation steps recorded by BV. Secondly, we show that the low H2S/protein ratio used in the bimane HPLC assay can result in undersaturation of the catalyst responsible for H2S oxidation. The latter can lead to underestimation of potential oxidation rates and may be as important as the nonspecificity of BV in explaining differences between assay results. Tissue-level sulfide oxidation is clearly widespread in marine invertebrates, but the catalyst(s) responsible remain(s) unidentified. The fact that sulfide-oxidation rates in vent polychaete tissues are similar to rates in non-vent species and appear to reflect a common basal level of sulfide-oxidizing activity in many animal tissues suggests that other defense mechanisms may be more important in the adaptation of these worms to the hydrothermal milieu.
18
Pagliai, F. A., and Carlos A. Jerez. "The Secretome of the Extremophilic Acidithiobacillus Ferrooxidans ATCC 23270." Advanced Materials Research 71-73 (May 2009): 183–86. http://dx.doi.org/10.4028/www.scientific.net/amr.71-73.183.
Abstract:
Acidithiobacillus ferrooxidans is a chemolithoautotrophic acidophile capable of catalyzing the oxidation of ferrous iron and sulfur reducing compounds. During the dissolution of ores A. ferrooxidans adheres to the solid substrate by hydrophobic and hydrophilic interactions and also extracellular polymeric substances may be involved. Nevertheless, many of these agents that participate in the process are unknown. Therefore, the identification and characterization of the extracellular proteome of A. ferrooxidans was addressed during this work. First, by searching the genome of A. ferrooxidans ATCC 23270 the putative genes coding for proteins present in most of the different secretion systems (type I, II, IV, V systems and the Usher pathway) were found. Second, when the secretion signal prediction server SubCel 1.0 was used, 26.7 % of the total open reading frames showed possible signals that would allow these proteins to leave the cytoplasm towards the internal and outer membranes, the periplasm, or the extracellular milieu. By using 2D-NEPHGE and MS sequencing we identified the eleven most abundant proteins present in the extracellular fraction. Proteins related to the transport and binding of solutes and the folding of proteins, among others were identified. Along with the non-classical pathway, the protein secretion systems identified could constitute the secretion machinery for the proteins found in the extracellular sub-proteome of A. ferrooxidans that as a whole constitute its secretome. Further studies of the extracellular proteins from this biomining microorganism will be important to find out their possible role if any, during bacteria-mineral interactions.
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Percy, Kevin E. "Geoscience of Climate and Energy 11. Ambient Air Quality and Linkage to Ecosystems in the Athabasca Oil Sands, Alberta." Geoscience Canada 40, no. 3 (October 31, 2013): 182. http://dx.doi.org/10.12789/geocanj.2013.40.014.
Abstract:
In 2010, there were 91 active oil sands projects in the Athabasca Oil Sands, Alberta where the Wood Buffalo Environmental Association monitors air quality and related environmental impacts. In 2012, ambient air concentrations of sulphur dioxide, nitrogen dioxide, and ammonia did not exceed the Alberta Ambient Air Quality Objectives. There was one exceedance of these objectives for ground-level ozone, and 62 exceedances for fine particulate matter with aerodynamic diameter ≤ 2.5 microns. There were 170 exceedances of the 1-hour hydrogen sulphide / total reduced sulphur odour threshold. The number of hourly exceedances has decreased since 2009, yet odours remain a serious concern in some communities. Based on the Air Quality Health Index (ozone, nitrogen dioxide, fine particulate matter), the risk from ambient air quality to human health from some pollutants was calculated to be low 96% to 98% of the time depending upon monitoring location, moderate 1% to 3.4%, high ≤ 0.4%, and very high ≤ 0.2% of the year. In a highly regulated setting like the Alberta oil sands, it is critical for stakeholders to quantify the spatial influences of emission source types to explain any consequential environmental effects. Source apportionment studies successfully matched source chemical fingerprints with those measured in terrestrial lichens throughout the region. Forensic receptor modeling showed source types contributing to elemental concentrations in the lichens included combustion processes (~23%), tailing sand (~19%), haul roads and limestone (~15%), oil sand and processed materials (~15%), and a general anthropogenic urban source (~15%). Re-suspended fugitive dust from operations, tailings dikes, quarrying, on-road transportation, and land clearing was found to contribute enrichment to a much greater degree than the hitherto assumed combustion source type.SOMMAIREEn 2010, il y avait 91 projets d’extraction en cours dans les sables bitumineux de l’Athabasca en Alberta, soit dans le secteur où la Wood Buffalo Environmental Association mesure la qualité de l'air et les répercussions sur les milieux de vie. En 2012, les concentrations dans l'air ambiant de dioxyde de soufre, le dioxyde d'azote et d'ammoniac n’ont pas dépassé les niveaux fixés par l’Alberta Ambient Air Quality Objectives. Il y a eu 1 dépassement de ces objectifs pour la concentration de l'ozone au niveau du sol, et 62 dépassements pour la concentration des particules fines d'un diamètre aérodynamique ≤ 2,5 micromètres. Il y a eu 170 dépassements pour la concentration du sulfure d’hydrogène pendant 1 heure / du seuil de l’odeur total de soufre réduit. Le nombre des dépassements horaires a diminué depuis 2009, mais les odeurs demeurent un grave problème dans certaines communautés. En fonction de la Cote air santé (ozone, dioxyde d'azote, particules fines), le risque de la qualité de l'air ambiant pour la santé humaine de certains polluants a été qualifiée de faible pour 96 % à 98 % des cas selon lieu de la mesure, de modérée dans 1 % à 3,4 %, plus élevé dans ≤ 0,4% des cas, et de très élevé dans ≤ 0,2% de l’année. Dans un cadre très réglementé comme celui des sables bitumineux de l'Alberta, il est essentiel pour les parties prenantes de quantifier spatialement les répercussions des divers types de sources d'émissions dans le but d’expliquer les conséquences sur les milieux de vie. Les études d’attribution des sources ont très bien recoupé celles des empreintes chimiques des sources mesurées dans les lichens terrestres dans toute la région. La modélisation par récepteurs forensiques a montré que les types de sources qui contribuent aux concentrations élémentaires dans les lichens proviennent des procédés de combustion (~ 23%), des sables résiduels (~ 19%), des routes de transport et du calcaire (~ 15%), des sables bitumineux et des matériaux transformés (~ 15%) et d’une source urbaine anthropique générale (~ 15%). On a établi que les poussières diffuses remises en suspension provenant de l'exploitation, les digues de résidus, les carrières, le transport routier et le défrichement contribuent à l’augmentation de la concentration à un degré beaucoup plus élevé que la combustion, qu’on ne l’avait estimé jusqu’à présent.DOI: http://dx.doi.org/10.12789/geocanj.2013.40.014
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Bullock, Grant C., Lorrie L. Delehanty, Sara L. Gonais, and Adam N. Goldfarb. "Iron Control of Erythropoiesis: A Novel Pathway in Which Aconitase Enzymes Couple Metabolic Flux with Cellular Development." Blood 110, no. 11 (November 16, 2007): 707. http://dx.doi.org/10.1182/blood.v110.11.707.707.
Abstract:
Abstract Erythroid iron deficiency, whether due to dimished body stores or histiocytic retention, diminishes marrow responsiveness to erythropoietin (Epo). Conversely, intravenous iron infusion augments marrow responsiveness to Epo, even in anemia patients with adequate pre-existing iron stores. Iron regulation of Epo-driven erythropoiesis affects proliferation and differentiation of early progenitors, prior to the commitment to heme production. Thus, while iron is essential for all cells, erythroid precursors manifest an exquisite sensitivity to iron deficiency, most likely as a rationing mechanism to protect other, more vital iron-dependent functions. Using primary human hematopoietic cultures with defined levels of transferrin saturation, we have confirmed the existence of a critical threshold of iron deprivation, at which erythroid progenitors display proliferative and maturation blockade while granulopoiesis and megakaryopoiesis remain unaffected. Extensive pharmacologic and genetic screening for components of this erythroid iron response pathway have identified the iron-sulfur cluster containing aconitase enzymes as a critical signaling node. Mitochondrial and cytosolic aconitase (mAcon & cAcon) interconvert citrate and isocitrate as a key step in the Krebs cycle. Firstly, treatment of iron deprived erythroid cultures with exogenous isocitrate, but not citrate, completely restored differentiation, as judged by glycophorin A (GPA) expression and hemoglobinization. By contrast, both citrate and isocitrate enhanced erythroid differentiation under iron replete conditions. Secondly, treatment of iron replete erythroid cultures with a specific aconitase inhibitor, fluorocitrate, induced a lineage-selective maturation blockade identical to that seen with iron deprivation. Thirdly, enzymography showed erythroid-lineage specific inactivation of both cAcon and mAcon in response to iron deprivation; immunoblotting showed no change mAcon protein levels as a function of either lineage or iron status. Fourthly, a retroviral genetic screen identified HBLD2, an iron-sulfur cluster assembly factor, as a protein whose overexpression reversed the erythroid maturation blockade associated with iron deprivation. Enzymography confirmed that overexpression of HBLD2 enhanced both cAcon and mAcon activities. Fifthly, administration to wild type, iron replete C57BL/6 mice of isocitrate at 200 mg/kg/day for 5 days caused a significant increase in peripheral red cell hemoglobinization, reflected by MCHC and Hb levels. Taken together, these results identify isocitrate as a positive regulator of Epo-mediated erythroid differentiation. In Epo-independent CD34+ cell culture systems, isocitrate did not enhance erythropoiesis. Therefore aconitase enzymes serve as a critical nexus in iron and Epo regulation of erythropoiesis, integrating cellular metabolism with developmental programming. The unique sensitivity of the erythroid lineage to iron deprivation appears to derive from a cellular milieu effect on the aconitase enzymes, promoting their inactivation under iron deprivation. Notably, IRP repression of mAcon translation does not contribute to the erythroid iron deprivation response pathway. This pathway may have relevance for future clinical approaches to Epo-refractory chronic anemias and polycythemia vera.
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Chehab, Rana, Adrienne Kwok, Oliver Fiehn, Ines Thiele, Amanda Ngo, Dinesh Barupal, Charles Quesenberry, Assiamira Ferrara, and Yeyi Zhu. "Maternal Microbial Metabolites and Risk of Fetal Growth Extremes: A Longitudinal Multi-Racial/Ethnic Cohort Study." Current Developments in Nutrition 6, Supplement_1 (June 2022): 628. http://dx.doi.org/10.1093/cdn/nzac061.012.
Abstract:
Abstract Objectives Fetal growth extremes [small- and large-for-gestational age (SGA and LGA)] represent high-risk phenotypes for cardiometabolic disorders. Metabolomic profiling of the in-utero milieu may elucidate pathophysiology of fetal growth extremes and inform dietary recommendations and upstream risk factors. We aimed to identify microbiome-derived metabolites associated with SGA and LGA. Methods A random sample of 140 SGA, 134 LGA and 140 appropriate for gestational age (AGA) was drawn from the Pregnancy Environment and Lifestyle Study cohort. Using fasting serum at gestational weeks (GW) 10–13 and 16–19,1167 known metabolites were measured by gas and liquid chromatography (LC)/time-of-flight mass spectrometry (TOF-MS) and hydrophilic interaction LC/quadrupole TOF-MS, of which 165 microbial metabolites were linked with the Virtual Metabolic Human Database. After adjusting for sociodemographic, lifestyle, reproductive history, and clinical factors, we identified significant pathways associated with risk of SGA and LGA vs. AGA using chemical similarity enrichment analysis, controlling for the false discovery rate (PFDR). Results At GW 10–13, branched-chain amino acids (AA), dicarboxylic acids (DA) and medium-chain hydroxy acids were positively, while phosphatidylcholines, saturated fatty acids (FA) and glucogenic AA were inversely associated with SGA risk (all PFDR < 0.01). At GW 16–19, positive associations of branched-chain AA and DA and inverse associations of saturated FA with SGA risk persisted, while unsaturated triglycerides (TG) were inversely associated with SGA risk (all PFDR < 0.01). At GW 10–13, glucogenic AA, DA, hippurates, phenylacetylglutamine and cresols were positively, whereas phosphatidylcholine and unsaturated TG were inversely associated with LGA risk (all PFDR < 0.04). At GW 16–19, carnitine, saturated TG, cyclic AA, DA, glyceric acids, phenylacetylglutamine and cresols were positively, while aromatic, basic and sulfur AA, sugar alcohols, phosphatidylcholines and unsaturated TG were inversely associated with LGA risk (all PFDR < 0.05). Conclusions Distinct microbial metabolites in early to mid-pregnancy are associated with SGA and LGA risk, calling for further investigation into microbiome-metabolome-host interactions. Funding Sources The research was supported by NIDDK, NIEHS, and NIH Office of Directors.
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Laville-Timsit, Liliane. "Néoformations de sulfures de fer et de zinc en milieu réducteur en aval du gisement Pb, Zn, Cu, Ag de Porte-aux-Moines (Côtes-du-Nord) : l'anomalie géochimique Pb-Zn des sols de Kérouaran. Neoformation of Fe and Zn sulphides, under reducing supergene conditions downstream of the Porte-aux-Moines (Côtes-du-NJOsd, France) Pb, Zn, Cu, Ag deposit : the Pb-Zn soil anomaly at Kerouaran." Sciences Géologiques. Bulletin 39, no. 3 (1986): 263–75. http://dx.doi.org/10.3406/sgeol.1986.1730.
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Sun, Wenyue, Jiao Sun, Qihang Ding, Manlin Qi, Jing Zhou, Yujia Shi, Jia Liu, et al. "Breaking Iron Homeostasis: Iron Capturing Nanocomposites for Combating Bacterial Biofilm." Angewandte Chemie, February 6, 2024. http://dx.doi.org/10.1002/ange.202319690.
Abstract:
Given the scarcity of novel antibiotics, the eradication of bacterial biofilm infections poses formidable challenges. Upon bacterial infection, the host restricts Fe ions, which are crucial for bacterial growth and maintenance. Having coevolved with the host, bacteria developed adaptive pathways like the hemin‐uptake system to avoid iron deficiency. Inspired by this, we propose a novel strategy, termed iron nutritional immunity therapy (INIT), utilizing Ga‐CT@P nanocomposites constructed with gallium, copper‐doped tetrakis (4‐carboxyphenyl) porphyrin (TCPP) metal‐organic framework, and polyamine‐amine polymer dots, to target bacterial iron intakes and starve them. Owing to the similarity between iron/hemin and gallium/TCPP, gallium‐incorporated porphyrin potentially deceives bacteria into uptaking gallium ions and concurrently extracts iron ions from the surrounding bacteria milieu through the porphyrin ring. This strategy orchestrates a "give and take" approach for Ga3+/Fe3+ exchange. Simultaneously, polymer dots can impede bacterial iron metabolism and serve as real‐time fluorescent iron‐sensing probes to continuously monitor dynamic iron restriction status. INIT based on Ga‐CT@P nanocomposites induced long‐term iron starvation, which affected iron‐sulfur cluster biogenesis and carbohydrate metabolism, ultimately facilitating biofilm eradication and tissue regeneration. Therefore, this study presents an innovative antibacterial strategy from a nutritional perspective that sheds light on refractory bacterial infection treatment and its future clinical application.
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Sun, Wenyue, Jiao Sun, Qihang Ding, Manlin Qi, Jing Zhou, Yujia Shi, Jia Liu, et al. "Breaking Iron Homeostasis: Iron Capturing Nanocomposites for Combating Bacterial Biofilm." Angewandte Chemie International Edition, February 6, 2024. http://dx.doi.org/10.1002/anie.202319690.
Abstract:
Given the scarcity of novel antibiotics, the eradication of bacterial biofilm infections poses formidable challenges. Upon bacterial infection, the host restricts Fe ions, which are crucial for bacterial growth and maintenance. Having coevolved with the host, bacteria developed adaptive pathways like the hemin‐uptake system to avoid iron deficiency. Inspired by this, we propose a novel strategy, termed iron nutritional immunity therapy (INIT), utilizing Ga‐CT@P nanocomposites constructed with gallium, copper‐doped tetrakis (4‐carboxyphenyl) porphyrin (TCPP) metal‐organic framework, and polyamine‐amine polymer dots, to target bacterial iron intakes and starve them. Owing to the similarity between iron/hemin and gallium/TCPP, gallium‐incorporated porphyrin potentially deceives bacteria into uptaking gallium ions and concurrently extracts iron ions from the surrounding bacteria milieu through the porphyrin ring. This strategy orchestrates a "give and take" approach for Ga3+/Fe3+ exchange. Simultaneously, polymer dots can impede bacterial iron metabolism and serve as real‐time fluorescent iron‐sensing probes to continuously monitor dynamic iron restriction status. INIT based on Ga‐CT@P nanocomposites induced long‐term iron starvation, which affected iron‐sulfur cluster biogenesis and carbohydrate metabolism, ultimately facilitating biofilm eradication and tissue regeneration. Therefore, this study presents an innovative antibacterial strategy from a nutritional perspective that sheds light on refractory bacterial infection treatment and its future clinical application.
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Chan, Nai-Ju, Yueh-Yin Chen, Chun-Chun Hsu, You Shuei Lin, Maxwell Zakeri, Seonwook Kim, Mehdi Khosravi, and Lu-Yuan Lee. "Release of ATP in the Lung Evoked by Inhalation of Irritant Gases in Rats." Journal of Applied Physiology, June 27, 2024. http://dx.doi.org/10.1152/japplphysiol.00137.2024.
Abstract:
Adenosine triphosphate (ATP) can be released into the extracellular milieu from various types of cells in response to a wide range of physical or chemical stresses. In the respiratory tract, extracellular ATP is recognized as an important signal molecule and trigger of airway inflammation. Chlorine (Cl2), sulfur dioxide (SO2), and ammonia (NH3) are potent irritant gases and common industrial air pollutants due to their widespread uses as chemical agents. This study was carried out to determine if acute inhalation challenges of these irritant gases, at the concentration and duration simulating the accidental exposures to these chemical gases in industrial operations, triggered the release of ATP in the rat respiratory tract; and if so, whether the level of ATP in bronchoalveolar lavage fluid (BALF) evoked by inhalation challenge of a given irritant gas was elevated by chronic allergic airway inflammation. Our results showed: 1) Inhalation of these irritant gases caused significant increases in the ATP level in BALF, and the magnitude of evoked ATP release was in the order of Cl2 > SO2 > NH3. 2) Chronic airway inflammation induced by ovalbumin-sensitization markedly elevated the ATP level in BALF during baseline (breathing room air) but did not potentiate the release of ATP in the lung triggered by inhalation challenges of these irritant gases. These findings suggested a possible involvement of the ATP release in the lung in the regulation of overall airway responses to acute inhalation of irritant gases and the pathogenesis of chronic allergic airway inflammation.