Petrological and geochemical characterization of Ge-bearing coals from the eastern Rhodopes, Bulgaria

The coals from Pchelarovo and Vulce Pole are perhydrogenated coals showing high sulphur content (3.2 - 6.2 wt%) and significant Ga and Ge contents (0 - 480 ppm) in organic matter (OM). The coals from Medenbuk could be perhydrogenated coals modified by weathering processes. They show low sulphur content (1.5 wt%), high homogeneous Ge contents in OM (~2500 ppm) and an unusual enrichment in Ge (up to 0.8 wt%) and V (2.8 wt%) in weathered zones of framboïdal pyrite. Sulphur isotopic study of pyrite and organic sulphur provides evidence of bacterial reduction of dominantly seawater sulphates. However taking account the geological context of the three basins, the introduction of volcanic fluids in the basins of Pchelarovo and Vulce Pole during their forma-tion cannot be excluded

Prolonged dialysis during ex vivo lung perfusion promotes inflammatory responses

Ex-vivo lung perfusion (EVLP) has extended the number of transplantable lungs by reconditioning marginal organs. However, EVLP is performed at 37°C without homeostatic regulation leading to metabolic wastes’ accumulation in the perfusate and, as a corrective measure, the costly perfusate is repeatedly replaced during the standard of care procedure. As an interesting alternative, a hemodialyzer could be placed on the EVLP circuit, which was previously shown to rebalance the perfusate composition and to maintain lung function and viability without appearing to impact the global gene expression in the lung. Here, we assessed the biological effects of a hemodialyzer during EVLP by performing biochemical and refined functional genomic analyses over a 12h procedure in a pig model. We found that dialysis stabilized electrolytic and metabolic parameters of the perfusate but enhanced the gene expression and protein accumulation of several inflammatory cytokines and promoted a genomic profile predicting higher endothelial activation already at 6h and higher immune cytokine signaling at 12h. Therefore, epuration of EVLP with a dialyzer, while correcting features of the perfusate composition and maintaining the respiratory function, promotes inflammatory responses in the tissue. This finding suggests that modifying the metabolite composition of the perfusate by dialysis during EVLP can have detrimental effects on the tissue response and that this strategy should not be transferred as such to the clinic

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Synthesis and properties of dimethoxychromenoacridinium ions

Des composés azaoxa[4]helicenes cationiques possédant une structure non-symétrique et hélicoïdale ont été synthétisés. Deux différentes approches mettant en jeu deux étapes de synthèse à partir d'un même précurseur ont été explorées. Afin de rendre possible la purification de l'azaoxa[4]helicenes, une nouvelle méthode impliquant une réaction de réduction sélective suivi d'une simple filtration sur gel de silice a été développée. Une étape d'oxydation avec rétention de configuration permet de récupérer l'espèce cationique. L'azaoxa[4]helicene a finalement pu être dédoublé à partir de l'adduit neutre en employant une technique de chromatographie en phase mobile liquide équipée d'une phase stationnaire chiral. Les propriétés optiques, chiroptiques, ainsi qu'électroniques ont été étudiées et comparées aux dioxo et diaza [4]helicenes cationiques et la configuration absolue des deux énantiomères a été déterminée. L'isolation d'un intermédiaire pendant l'étude a permis de proposer un mécanisme vers la formation de l'azaoxa[4]helicenes cationic

Mode de genèse et valorisation des minerais de type black shales : cas du Kupferschiefer (Pologne) et des schistes noirs de Talvivaara (Finlande)

This thesis was carried out in the frame of an EU-FP6 project (Bioshale) and has, as main objective a better understanding of metal concentration processes in black shale ores and their beneficiation by hydro-and biotechnologies. The low mature organic matter (OM) of the Lubin ore (Kupferschiefer) played a role during syn-, dia- and epigenetic metal enrichment processes. The ore contains 7% of Cu as well as Ag, Co, Ni, Pb, Zn, as sulphides (chalcocite, covellite, bornite, chalcopyrite...). The concentration of some elements (Cu-Fe-Co-Ni-V) is low into the OM (=0.2%). The more mature OM from Polkowice (Kupferschiefer) contains less associated elements (Fe- V-S). Base metal contents are lower (90%) than during heap leaching (7%) ainsi que Ag, Co, Ni, Pb, Zn,... y sont principalement présents sous forme de chalcocite, covellite, bornite, chalcopyrite... Certains éléments (Cu, Fe, Co, Ni, V) se retrouvent à de faibles teneurs dans la MO (=0,2%). La MO plus mature de Polkowice (Kupferschiefer), contient moins d'éléments associés (Fe, V, S). Les teneurs en métaux de base y sont plus faibles (90%) que par lixiviation en tas (<75% à Talvivaara). Ces taux dépendent peu voir pas de la présence de la MO. Quelque soit le traitement, la chalcocite, la digénite, la bornite et la pyrrhotite sont plus facilement lixiviables que la pyrite et la chalcopyrite. Le biotraitement du minerai de Lubin ne permet pas la récupération de Ag et Pb. Cependant, plus de 92% de ces éléments sont solubilisés par un traitement additionnel du résidu de biolixiviation

Cationic triangulenes and helicenes: synthesis, chemical stability, optical properties and extended applications of these unusual dyes

Cationic triangulenes and helicenes are highly stable carbocations with planar and helical conformations respectively. These moieties are effective dyes with original absorption and emission properties. Over the last decade, they have received greater attention and are considered as valuable tools for the development of innovative applications. In this review, the synthesis of these unique compounds is presented together with their core chemical and physical properties. Representative applications spanning from surface sciences to biology and chemistry are presented

Convergent Synthesis, Resolution, and Chiroptical Properties of Dimethoxychromenoacridinium Ions

Cationic azaoxa[4]helicenes can be prepared in a single step from a common xanthenium precursor by addition of nucleophilic amines under monitored conditions (160 °C, 2 min, MW). The (−)-(M) and (+)-(P) enantiomers can be separated by chiral stationary-phase chromatography. Determination of the absolute configuration and racemization barrier (ΔG(433 K) 33.3 ± 1.3 kcal·mol–1) was achieved by VCD and ECD spectroscopy, respectively.Cationic azaoxa[4]helicenes can be prepared in a single step from a common xanthenium precursor by addition of nucleophilic amines under monitored conditions (160 °C, 2 min, MW). The (−)-(M) and (+)-(P) enantiomers can be separated by chiral stationary-phase chromatography. Determination of the absolute configuration and racemization barrier (ΔG(433 K) 33.3 ± 1.3 kcal·mol–1) was achieved by VCD and ECD spectroscopy, respectively

Organic and mineral characteristics of Kupferschiefer ore from Lubin mine (Poland): implications for bioleaching of the ore.

International audienceThe ore mineral and organic matter content of the Lubin black shale (LBS) are compared with copper concentrate (LC) obtained by flotation. Study of a mineralized profile shows a good correlation between the S, TOC and Cu, Co and Ag content, suggesting syngenetic bacterial sulfate reduction (BSR) accumulation. The presence of disseminated and fracture filling rather than framboidal Cu-minerals, suggests formation via diagenetic processes. Compared to the black shale, the LC shows a lower HI and a higher OI, and a much more diverse ore mineral content. The black shale ore is composed of 15 vol. % sulfide, this proportion reaches 27 % in the LC whereas the TOC is similar in the LC and LBS. The ore mineral diversity in the LC is due to the contribution of mineralized sandstone and dolomite adjacent the black shale ore

Mode de genèse et valorisation des minerais de type black shales (cas du Kupferschiefer (Pologne) et des schistes noirs de Talvivaara (Finlande))

Réalisée dans le cadre du projet UE Bioshale, cette thèse vise à comprendre les processus de concentration des métaux dans les gisements de black shale, et à valoriser ces minerais par voies hydro- et biotechnologiques.La matière organique (MO), peu mature, du minerai de Lubin (Kupferschiefer) est intervenue dans les processus syn-, dia- et épigénétiques de concentration des métaux. Le cuivre (>7%) ainsi que Ag, Co, Ni, Pb, Zn, y sont principalement présents sous forme de chalcocite, covellite, bornite, chalcopyrite Certains éléments (Cu, Fe, Co, Ni, V) se retrouvent à de faibles teneurs dans la MO (£0,2%). La MO plus mature de Polkowice (Kupferschiefer), contient moins d éléments associés (Fe, V, S). Les teneurs en métaux de base y sont plus faibles (90%) que par lixiviation en tas (<75% à Talvivaara). Ces taux dépendent peu voir pas de la présence de la MO. Quelque soit le traitement, la chalcocite, la digénite, la bornite et la pyrrhotite sont plus facilement lixiviables que la pyrite et la chalcopyrite. Le biotraitement du minerai de Lubin ne permet pas la récupération de Ag et Pb. Cependant, plus de 92% de ces éléments sont solubilisés par un traitement additionnel du résidu de biolixiviation.ORLEANS-BU Sciences (452342104) / SudocORLEANS-ISTO (452342307) / SudocSudocFranceF