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Chronic low back pain (CLBP) is one of the most common diagnoses encountered when considering years lived with disability. The degenerative changes of the lumbar spine include a wide spectrum of morphological modifications visible on imaging, some of them often asymptomatic or not consistent with symptoms. Phenotyping by considering both clinical and imaging biomarkers can improve the management of CLBP. Depending on the clinical presentation, imaging helps determine the most likely anatomical nociceptive source, thereby enhancing the therapeutic approach by targeting a specific lesion. Three pathologic conditions with an approach based on our experience can be described: (1) pure painful syndromes related to single nociceptive sources (e.g., disk pain, active disk pain, and facet joint osteoarthritis pain), (2) multifactorial painful syndromes, representing a combination of several nociceptive sources (such as lumbar spinal stenosis pain, foraminal stenosis pain, and instability pain), and (3) nonspecific CLBP, often explained by postural (muscular) syndromes.

Resume Introduction La formation procedurale de l’interne comprend l’apprentissage des nœuds arthroscopiques. Les maquettes comprennent des modules de formation en arthroscopie de complexite croissante, mais il n’existe pas de guide de formation procedurale pour l’acquisition des competences en nœuds arthroscopiques. Peu d’etudes s’interessent a l’apprentissage des nœuds arthroscopiques chez des internes en formation. L’objectif de l’etude etait de determiner le type de nœud arthroscopique qui associe la plus grande facilite et fiabilite d’apprentissage et la meilleure reussite de realisation chez des internes en formation. Materiel et methode Chaque participant devait executer 5 nœuds avec un ordre d’apprentissage tire au sort : nœuds de Tennesse, de Duncan, de chirurgien (RevoKnot), de Nicky et le SMC (Samsung Medical Center). Le support de travail mis a disposition etait la FAST Workstation (Sawbones, Vashon Island, WA). Chaque participant avait a sa disposition un testeur de nœuds (Sawbones®, FAST Knot Tester™, Vashon Island, WA) permettant une auto-evaluation de la qualite biomecanique des nœuds afin d’optimiser l’apprentissage. Chaque participant devait noter la facilite d’apprentissage de ce nœud sur une echelle visuelle allant de 0 a 10. Il devait egalement noter la fiabilite des nœuds realises sur une echelle visuelle allant de 0 a 10. Un evaluateur independant evaluait la reussite des nœuds realises ; un nœud etait considere comme reussi si apres application d’une charge de 60N il presentait un glissement inferieur a 3 mm. Resultats Dix participants ont ete inclus dans cette etude. 250 nœuds ont ete realises et evalues. La facilite d’apprentissage base sur l’echelle visuelle etait du plus simple au plus complique le nœud de chirurgien, de Pecheur, de Tennesse, de Nicky et le nœud SMC (p Conclusion Le nœud de chirurgien presente la plus grande facilite d’apprentissage. Le nœud de Nicky presente le meilleur de taux de reussite chez des internes en formation. Niveau de preuve II, prospectif randomise de faible puissance.

3D Project, standing for DMX™ Demonstration Dunkirk, is a European funded project to demonstrate an innovative CO2 capture process at semi-industrial scale: DMX™. The 11 partners of this project gathered their forces to demonstrate the capture process and to study the CCS chain (capture, transport and Storage) allowing to decrease the CO2 emissions from industries (steel mills, refineries, waste-to-energy plants etc). Objectives/Scope Carbon capture is due to play a fundamental rote in achieving Net Zero Emissions scenario in 2050. Amine scrubbing is considered nowadays a suitable technology for the sectors with large-fixed CO2 emissions due to its robustness, adaptability, and capability of producing a highly concentrated CO2 stream, suitable to be transported. Four main challenges need to be addressed for the industrial deployment of this technology: process footprint reduction, process energy penalty reduction, solvent and VOC emission limitation and long-term process stability. Some challenges can be addressed through solvent formulation and process configuration. IFPEN has developed a novel solvent and process configuration, the DMX™ process, showing promising results in terms of energy consumption and process stability. This work aims at the demonstration of the DMX™ process by means of a set of experimental campaigns with a demonstration plant treating real gases in the frame of H2020 funded project called 3D (grant agreement n° 838031). The demonstration plant is installed in the Steel Mill of ArcelorMittal Dunkirk and will absorb CO2 present in the blast furnaces gases. The design and construction of the unit is realized under the supervision of Axens. The demonstration plant is operated by a mixed team from IFPEN and TotalEnergies. Methods, Procedures, Process The DMXTM technology is a CO2 chemical absorption process involving a demixing solvent. This process consists in the continuous operation of two sections: 1) the absorption section, in which the CO2 is captured by the lean solvent, and 2) the regeneration section, in which the rich solvent is thermally stripped from the CO2 and recirculated to the absorption section. The particularity of this process is the solvent demixing in the regeneration section. Only the CO2 rich aqueous stream is thermally stripped. In addition, since the regeneration of the solvent can be performed at a relative high temperature (150-160 °C), the DMX process produces a relatively high-pressure CO2 effluent (5-6 bara). Hence, energy and investment cost savings are expected to be obtained.

Artificial intelligence (AI) is increasingly being studied in musculoskeletal oncology imaging. AI has been applied to both primary and secondary bone tumors and assessed for various predictive tasks that include detection, segmentation, classification, and prognosis. Still, in the field of clinical research, further efforts are needed to improve AI reproducibility and reach an acceptable level of evidence in musculoskeletal oncology. This review describes the basic principles of the most common AI techniques, including machine learning, deep learning and radiomics. Then, recent developments and current results of AI in the field of musculoskeletal oncology are presented. Finally, limitations and future perspectives of AI in this field are discussed.

Resume Introduction Il n’existe pas de consensus sur les solutions de rattrapage en cas d’echec apres arthroplastie trapezometacarpienne. La preservation du trapeze et la mise en place d’une prothese en pyrocarbone de type CMI® sont des solutions permettant d’eviter le raccourcissement et de preserver la cinematique du pouce. Le but de cette etude etait d’evaluer les resultats cliniques et radiographiques de 28 reprises d’arthroplastie trapezometacarpienne par implant en pyrocarbone CMI® a moyen terme. Materiel et methode Il s’agit d’une etude retrospective d’une serie continue de 28 patients de 63,5 ans d’âge moyen. Le delai moyen apres l’arthroplastie initiale etait de 6,1 ans. Le cote opere etait le cote dominant dans 70 % des cas. La chirurgie comprenait l’ablation de la prothese, une reconstruction trapezienne par greffe osseuse et la mise en place d’un implant en pyrocarbone CMI®. Le suivi consistait en une evaluation fonctionnelle (echelle visuelle analogique de douleur, score Quick DASH, satisfaction), physique (Kapandji, Grip test, Key pinch, Tip pinch) et radiologique (recherche de complication, mesure du lisere radiotransparent, de la hauteur scapho-metacarpienne, du centrage de l’implant et du remodelage osseux). Resultats Au recul moyen de 7,5 ans, aucune reprise chirurgicale n’a ete realisee. Le score moyen de douleur etait de 1,07 et le score Quick DASH moyen de 13 %. Vingt-cinq patients (89 %) etaient satisfaits apres la chirurgie. L’indice de Kapandji a ete significativement ameliore de 7,50 a 9,46 en moyenne. Le Grip test a ete significativement ameliore de 16,68 kg a 21,50 kg en moyenne. Le Key pinch moyen postoperatoire etait par rapport au cote oppose de 93 %. Le Tip pinch moyen postoperatoire etait par rapport au cote oppose de 88 %. Sur le plan radiographique, on ne rapporte aucune luxation ni fracture. Nous avons observe un remodelage du trapeze lie a l’empreinte du pyrocarbone avec une bonne tolerance a moyen terme. Conclusion Dans les cas de reprise de prothese totale trapezometacarpienne, la mise en place d’un implant en pyrocarbone CMI® associee a une reconstruction du trapeze semble etre une bonne alternative a la trapezectomie generalement proposee. La reconstruction du trapeze, et la mise en place de cette hemi-arthroplastie preserve la projection, la longueur et la stabilite du pouce. L’amelioration fonctionnelle apportee au patient par cette solution en fait une perspective therapeutique interessante. Niveau de preuve IV ; etude retrospective sans groupe controle.

Resume Introduction L’acromioplastie est un geste controverse. Techniquement, il s’agit d’une resection osseuse. Neanmoins, il n’y a pas de technique de reference et la resection n’est souvent pas quantifiee. Nos objectifs etaient : 1/Evaluer la qualite methodologique des etudes concernant l’acromioplastie ; 2/Identifier les series quantifiant l’acromioplastie ; 3/Rechercher une association statistique entre resultats cliniques et quantification de la resection acromiale. Materiel et methodes La revue systematique a ete realisee selon les criteres PRISMA avec les moteurs de recherche PubMed, Springer et Ovid. Nous avons inclus tous les articles faisant reference a l’acromioplastie en franccedil;ais ou anglais. Les articles ont ete analyses par 2 chirurgiens et ceux avec description complete de la technique operatoire ont ete selectionnes. 1/Nous avons evalue la methodologie des articles selon une echelle de qualite a 3 niveaux et basees sur les criteres suivants : objectif de l’acromioplastie, evaluation peroperatoire de la resection, evaluation postoperatoire radiographique. 2/Nous avons identifie les resultats des articles ayant une methodologie robuste et disposant de donnees quantitatives. 3/Nous avons cherche une association statistique entre resultats cliniques et quantification de la resection acromiale. Resultats Parmi les 250 articles trouves, nous avons selectionne 94 articles. Parmi les articles, 1/44 (47 %, n = 94) precisaient l’objectif, 53 (56 %, n = 94) comportaient un critere d’evaluation clinique peroperatoire, 13 (14 %, n = 94) comportaient une evaluation postoperatoire radiographique. La qualite de la methodologie etait insuffisante pour 33 articles (35 %, n = 94), faible pour 23 articles (24 %, n = 94) et robuste pour 38 articles (40 %, n = 94). 2/7 articles (7,5 %, n = 94) disposaient de resultats quantitatifs. 3/3 series permettaient par leur methodologie la recherche d’une association statistique entre resultats cliniques et quantification de l’acromioplastie, mais seule 1 utilisait une evaluation radiographique reproductible par la mesure du Critical shoulder angle (CSA). Cette etude mettait en evidence une association statistique positive entre resultats cliniques et diminution du CSA. Conclusion La methodologie utilisee dans les etudes sur l’acromioplastie est en grande majorite insuffisante et la resection acromiale est le plus souvent non quantifiee. Les donnees actuelles sont limitees pour evaluer l’interet du geste. Nous recommandons l’utilisation d’une " Check List for Acromioplasty Studies " a inclure a la methodologie des etudes futures. Il n’existe actuellement pas de methode de reference pour l’evaluation et la quantification de l’acromion reseque. L’utilisation de l’angle CSA semble recommandable mais d’autres methodes d’evaluation sont peut-etre a developper. Niveau de preuve IV ; Revue systematique de preuves de niveau 1 a 4.

Purpose The identification of pathological mediastinal lymph nodes is an important step in the staging of lung cancer, with the presence of metastases significantly affecting survival rates. Nodes are currently identified by a physician, but this process is time-consuming and prone to errors. In this paper, we investigate the use of artificial intelligence–based methods to increase the accuracy and consistency of this process. Methods Whole-body 18F-labelled fluoro-2-deoxyglucose ([18F]FDG) positron emission tomography/computed tomography ([18F]FDG-PET/CT) scans (Philips Gemini TF) from 134 patients were retrospectively analysed. The thorax was automatically located, and then slices were fed into a U-Net to identify candidate regions. These regions were split into overlapping 3D cubes, which were individually predicted as positive or negative using a 3D CNN. From these predictions, pathological mediastinal nodes could be identified. A second cohort of 71 patients was then acquired from a different, newer scanner (GE Discovery MI), and the performance of the model on this dataset was tested with and without transfer learning. Results On the test set from the first scanner, our model achieved a sensitivity of 0.87 (95% confidence intervals [0.74, 0.94]) with 0.41 [0.22, 0.71] false positives/patient. This was comparable to the performance of an expert. Without transfer learning, on the test set from the second scanner, the corresponding results were 0.53 [0.35, 0.70] and 0.24 [0.10, 0.49], respectively. With transfer learning, these metrics were 0.88 [0.73, 0.97] and 0.69 [0.43, 1.04], respectively. Conclusion Model performance was comparable to that of an expert on data from the same scanner. With transfer learning, the model can be applied to data from a different scanner. To our knowledge it is the first study of its kind to go directly from whole-body [18F]FDG-PET/CT scans to pathological mediastinal lymph node localisation.

International audience; Objectives: To evaluate the reliability of attenuation values of the liver parenchyma and focal liver lesions on virtual unenhanced images from arterial (VUEart) and portal venous phases (VUEport) compared to native unenhanced (NU) attenuation values in patients referred for assessment of malignant liver lesions.Methods: Seventy-three patients with confirmed primary or metastatic liver tumors who underwent a multiphase contrast-enhanced rapid-switching kVp dual-energy CT (rsDECT) were included in this IRB-approved retrospective study. Both qualitative and quantitative analyses - including the lesion-to-liver contrast-to-noise ratio (LL-CNR) - were performed and compared between NU and both VUEart and VUEport images.Results: The mean liver attenuation values were significantly lower in VUEart images (56.7 ± 6.7 HU) than in NU images (59.6 ± 7.5 HU, p = 0.008), and were comparable between VUEart and VUEport images (57.9 ± 6 UH, p = 0.38) and between VUEport and NU images (p = 0.051). The mean liver lesions attenuation values were comparable between NU, VUEart and VUEport images (p = 0.60). Strong and significant correlations values were found both in liver lesions and tumor-free parenchyma (r = 0.82-0.91, p < 0.01). The mean LL-CNR was significantly higher in VUEart and VUEport images than in NU images (1.7 ± 1 and 1.6 ± 1.1 vs 0.9 ± 0.6; p < 0.001), but was comparable between VUEart and VUEport images (p > 0.9). Lesion conspicuity was significantly higher in VUEport images than in NU images (p < 0.001).Conclusion: VUEport images derived from 3rd generation rsDECT could confidently replace NU images in patients undergoing assessment for malignant liver lesions. These images provide comparable attenuation values in both liver lesions and liver parenchyma while reducing the radiation dose and scanning time.

Slurry phase hydroconversion is a developing technology with the potential to completely upgrade Vacuum Residues (VR). In this work we use data from a continuous pilot plant with recycle to test and extend an existing distributed lumped kinetic model. The new data includes results from 134 steady state experiments with a Heavy Iran VR, including some at very high conversion, and allows sediment production rates to be quantified as well as sulphur removal in the form of H2S. The purpose of the work is to study the impact of the deep conversion reaction conditions and feedstock on the reaction kinetics. The model uses nineteen distributed lumps to represent the heavy hydrocarbons undergoing hydroconversion and hydrodesulphurisation with VR defined as the boiling range > 525°C. Reaction rates are based on molar concentrations. Hydrogen consumption and sediment production are taken into account in the model, as well as vapour liquid mass transfer resistances and vapour-liquid equilibrium. Parameter estimation has been carried out and the model provides a good fit with the experimental data. The modelling exercise found that, at very high conversions, thermal reactions give way to a cascade of catalytic reactions. The model gave a moderate fit for hydrogen consumption rates, which are strongly dependent on feedstock. Accumulation of sediment at high conversions was identified and well represented and the description of hydrodesulfurisation rates as proportional to cracking rates was validated.

Introduction Pulmonary fibrosing sarcoidosis is associated with increased mortality. This study was aimed to explore the prognosis value of a panel of parameters for predicting mortality. Methods This retrospective study included 216 patients with confirmed stage 4 pulmonary sarcoidosis. Stage 4 diagnosis date served as baseline. The following information was systematically present at baseline: epidemiological characteristics; treatments; pulmonary function; composite physiologic index (CPI); systolic pulmonary artery pressure at echocardiography; pulmonary fibrosis extent, main pulmonary artery/ascending aorta diameters ratio (MPAD/AAD) and MPAD/body surface area (BSA) measured and calculated using computed tomography, Walsh's algorithm based on CPI, lung fibrosis extent and MPAD/AAD ratio, and modified Walsh's algorithm with MPAD/BSA replacing MPAD/AAD allowed to estimate good or bad prognosis profiles. The primary outcome of the study was all cause mortality and lung transplantation. The value of baseline parameters was tested as predictors of mortality using univariate and multivariate analyses. Results Median follow-up was 105 months. There were 41 deaths and 5 transplantations. At multivariate analysis, survival was independently predicted by several parameters including CPI, lung fibrosis extent, pulmonary hypertension at echography or MPAD/BSA ratio, Walsh's algorithm, and geographic origin. The modified Walsh's algorithm was most highly predictive. Conclusion Survival was best predicted by geographic origin, lung fibrosis extent, PH at echography or MPAD/BSA ratio, as well as by various scores among them the modified Walsh's algorithm had very high predictive value thanks to MPAD/BSA ratio which accurately predicted mortality.

Introduction There is no consensus on the best salvage option after a failed trapeziometacarpal prothesis. Conserving the trapezium and inserting a pyrocarbon hemiarthroplasty implant will prevent thumb shortening and preserve the thumb's motion. The aim of this study was to evaluate the clinical and radiological outcomes in the medium term of trapeziometacarpal prothesis revisions done using the CMI pyrocarbon implant. Patients and methods This was a retrospective study of 28 patients with a mean age of 63.5 years. The mean time to revision was 6.1 years after the initial arthroplasty. The dominant side was operated in 70% of patients. The surgery consisted of removing the existing prosthesis, reconstructing the trapezium with a bone graft, and inserting the CMI pyrocarbon implant. The review consisted of a functional assessment (visual analog scale for pain, QuickDASH score, patient satisfaction), physical assessment (Kapandji, grip strength, key pinch strength, tip pinch strength) and radiological assessment (complications, radiolucent lines, scaphometacarpal height, implant centering, bone remodeling). Results At a mean follow-up of 7.5 years, no further surgical revisions were needed. The mean QuickDASH score was 1.1 and the mean QuickDASH was 13%. Twenty-five patients (89%) were satisfied with the outcome. The Kapandji score improved significantly from 7.5 to 9.5 on average. Grip strength improved significantly from 16.7 kg to 21.5 kg on average. The mean postoperative key pinch strength was 93% of the contralateral side. The mean postoperative tip pinch strength was 88% of the contralateral side. There were no fractures or dislocations visible on the radiographs. However, there was bone remodeling in the trapezium related to the pyrocarbon implant's indentation that was well tolerated by patients in the medium term. Conclusion For revision of failed trapeziometacarpal prothesis, inserting the CMI pyrocarbon implant combined with trapezium reconstruction appears to be a good alternative to the more commonly used trapeziectomy procedure. Reconstructing the trapezium and inserting this hemiarthroplasty implant preserves the thumb's projection, length, and stability. The functional improvement experienced by patients makes this a relevant treatment option. Level of evidence IV; retrospective study without control group.

The impact of recycling unconverted residue on slurry-phase hydroconversion performance was investigated in a continuous microscale pilot unit operated in once-through (OTOM) and recycling (ROM) op...

Objectives: In thrower’s shoulder pathology, scapulothoracic (S) dyskinesia (D) is classified by Kibler in 3 stages. However, the clinical or radiological diagnosis of SD is difficult and not very reproducible. The objective of this study was to evaluate scapular positioning on dry bones using low-dose 3D EOS imaging. Methods: A full-scale dry-bone S model (MODEL) was created which included the 2 scapulae and the thorax. A system of wedges enables adjustment of the right scapula to simulate the 3 stages of SD (MODEL0, MODEL1, MODEL2, MODEL3). Each MODEL was imaged in 7 random positions. The following points were identified by 2 observers: C7, T12, the xiphoid process, the inferomedial angle, the coracoid and the fulcrum. 28 S positioning measurements were taken. Inter- and intra-observer reproducibility were evaluated. Results: The thoracic and scapular points of interest are easily identified except for the fulcrum. The inter- and intra-observer reproducibility of the measurements were 94% and 94% for superior translation, 90% and 87% for protraction, 96% and 96% for anterior tilt, 75% and 86% for internal rotation, and 91% and 91% for lateral rotation. The average difference between the measurements of the 2 observers was -0.1 cm for distances (-3.3; 0.5; +/- 0.5) and -0.3° for angles (-8; 13; +/- 2.8). Conclusion: Bi-planar EOS imaging allows simple reproducible measurement of S positioning on dry bone. It could be used for diagnostic evaluation and quantification of SD. Low irradiation could play a role in the therapeutic follow-up. The potential in clinical use is yet to be confirmed.

Procedural training of orthopedic surgery residents includes learning arthroscopic knot-tying. The models used comprise arthroscopy training modules of increasing complexity, although there is no procedural training guide for the acquisition of arthroscopic knot-tying skills. Few studies have focused on how residents learn arthroscopic knot-tying. The aim of our study was to determine the type of arthroscopic knot that is the easiest to perform and learn and that can be done the most successfully by orthopedic surgery residents.Each participant had to learn five knots in a random order: Tennessee slider, Duncan loop, Revo knot (Surgeon's knot), Nicky knot, and the SMC (Samsung Medical Center) knot. The FAST Arthroscopy Workstation™ (Sawbones, Vashon Island, WA) was used for this study. Each participant could use a FAST Knot Tester™ (Sawbones®, Vashon Island, WA) to evaluate by themselves the biomechanical properties of the knots to optimize learning. Each participant had to rank how easy it was to learn this knot on a visual scale from 0 to 10. They also had to rank the reliability of the knots done on a visual scale from 0 to 10. Then, an independent rater assessed whether the knots were completed successfully; a knot was considered successful if it stretched by less than 3 mm when 60 N of load was applied.Ten participants were included in the study; 250 knots were done and evaluated. When ranked from simplest to most complicated, the easiest knot to learn was the Surgeon's knot, followed by the Duncan loop, Tennessee slider, Nicky knot and SMC knot (p0.0001). The overall success rate for the knots was 80%. There was a statistical trend for the Nicky being done better than the other arthroscopic knots (88% success rate).For orthopedics surgery residents, the surgeon's knot (Revo knot) was the easiest to learn, while the Nicky knot had the highest success rate.II; prospective, randomized study with low power.

International audience; A detailed distributed lumped kinetic model for slurry phase Vacuum Residue hydroconversion process (boiling range 525 + °C) has been constructed. Simulated distillation and Gel Permeation Chromatography analysis results were combined to estimate feedstock and product compositions over the whole boiling range. The model uses 21 distributed lumps to represent the hydrocarbons, takes hydrogen consumption into account and calculates reaction rates using molar concentrations. Vapour liquid mass transfer resistances and vapour-liquid equilibrium are also accounted for. The resulting model represents the evolution of the reaction mixture physical properties well and provides a good fit with the experimental data. From estimated parameters, it is deduced that thermally activated and catalytic reactions in cascade occur simultaneously and also that material boiling above 750 °C is converted in a different manner to lighter material.

International audience; In this work, Arabian light atmospheric residue and Safaniya vacuum residue were hydroconverted in a slurry phase semi-batch stirred tank reactor at 15 MPa for a wide range of temperatures (420–440 °C) and reaction times up to 4 h. Experimental data was used to develop a semi-batch reactor model including vapor-liquid equilibrium, gas-liquid mass transfer and gas phase hydrodynamics. Mass transfer and kinetic parameters were estimated by minimizing not only the total masses of products but also the outlet gas flow dynamics. Mass transfer and hydrogen consumption were compared against former studies using a batch reactor, a continuous stirred tank reactor and work by other authors, reported in the literature. Higher hydrogen consumption was achieved with the semi-batch reactor and no hydrogen mass transfer limitation was observed. Therefore, it was concluded that this setup is more suited and reliable for studying the chemical kinetics of slurry-phase hydroconversion of petroleum residues and permits improved representation of the role of hydrogen compared with current models.

Activity and stability of cobalt nanoparticles supported on mesoporous oxides is of extreme importance for the design of efficient catalysts for low-temperature Fischer–Tropsch synthesis. Catalyst deactivation is a major challenge of this reaction. The identification of mechanisms of catalyst deactivation is indispensable for optimizing the catalyst lifetime and hydrocarbon productivity. Most of the previous reports have addressed the modification of the bulk catalyst structure during Fischer–Tropsch synthesis. The present paper provides the first direct experimental evidence of surface oxidation of supported cobalt metal nanoparticles in the Fischer–Tropsch reaction. In addition to other deactivation phenomena, the uncovered surface oxidation of cobalt nanoparticles is likely to be a major reason for catalyst deactivation at higher reaction temperatures and carbon monoxide conversions.

SSCI-VIDE+ECI2D+TJA:DGU:ELE:MLA:CGE:MTF; International audience; The kinetics of atmospheric petroleum residue hydroconversion with a dispersed catalyst was studied. A methodology has been developed in order to transpose the chemical kinetics (reaction network, stoichiometry, and kinetic constants) obtained with a batch reactor by Nguyen et al. to a continuous reactor [Nguyen, T. S.; Tayakout-Fayolle, M.; Ropars, M.; Geantet, C. Chem. Eng. Sci. 2013, 94, 214]. Their five-lump kinetic model takes into account vaporliquid mass transfer, vaporliquid equilibriums, and hydrogen consumption. Consequently, hydrodynamics and vaporliquid mass transfer of the micropilot unit's reactor were studied in a cold mock-up by tracer experiments. The same thermodynamic model given by Nguyen et al. was used, and the flash calculations were performed using ProSimPlus software. Experimental data were obtained in the micropilot unit at 420, 430, and 440 degrees C with a dispersed catalyst for residence times of 1 and 2 h. The catalyst precursor, an oil-soluble molybdenum naphthenate, was added to obtain a molybdenum concentration of 600 wt ppm in the feedstock. The total pressure was 12 MPa with a hydrogen-to-feed ratio of 500 N m(3)/m(3). The methodology was validated by comparing the model's output with the experimental results.

The Fischer–Tropsch synthesis was evaluated on cobalt based catalyst supported on a medium surface area SiC foam ceramic in a fixed-bed configuration. The catalytic results were compared with those obtained on a Co/Al2O3 foam catalyst. At medium conversion (

Introduction Le test d’hyper-abduction (HA) a ete decrit en 2001. Sur epaule saine, l’HA serait inferieure a 90° dans 95 % des cas. Sur epaule instable, l’HA serait superieure a 105° ou declencherait une apprehension. Cependant, les patients hyperlaxes etaient exclus de l’etude originale. L’objectif de notre etude etait d’evaluer le test d’HA dans l’instabilite anterieure avec ou sans hyperlaxite. Notre hypothese principale etait que l’HA est souvent superieure a 90° sur epaule saine et qu’il n’y a pas de difference significative entre les 2 epaules. Notre hypothese secondaire etait que l’HA n’est pas un test satisfaisant d’instabilite mais une mesure de laxite. Methodologie Serie continue prospective de patients avec instabilite anterieure. Le test etait systematise avec maintien des scapulas par sangle, mise en abduction maximale et mesure informatisee. Sur l’epaule atteinte, nous avons defini le test d’HA comme un test d’instabilite (HAI) : positif s’il declenche une apprehension ou si la mesure est superieure de 15° par rapport au cote sain. Sur epaule saine, nous l’avons defini comme un test de laxite (HAL) mesurant une amplitude et nous avons cherche une correlation avec le score de Beighton de laxite constitutionnelle et la laxite anterieure (RE1 ?85°). Resultats Trente-neuf patients ont ete inclus : 35 hommes, 4 femmes, moyenne d’âge 22 ans. Cinquante et un pour cent pratiquaient un sport a risque et 54 % en competition. Le score ISIS moyen etait de 4,6 (± 2,9 ; 1 ; 10). Le score de Beighton moyen etait de 2,3 (± 2,4 ; 0 ; 8). La rotation externe RE1 moyenne etait de 86° (± 12 ; 60 ; 130), 24 patients (62 %) avaient une RE1 ?85° et 15 (38 %) une RE1 > 85°. Le test d’HA a declenche une apprehension pour 11 cas (28 %). Pour les patients sans apprehension, l’HA moyenne cote atteint etait de 116,8° (± 10,9 ; 100 ; 140) et de 118,4° (± 7,7 ; 110 ; 130) cote sain. La difference moyenne etait de 1,6° (± 7,6 ; −20 ; 15) et non significative (p = 0,36). Le test HAI avait une sensibilite de 31 %. Cote sain, la mesure HAL etait correlee au score de Beighton (p = 0,003) et plus eleve pour les patients avec laxite anterieure (121,5°) que sans (116,0° ; p = 0,04). Conclusion En pratique courante sur patients instables, le test d’HA est superieur a 115° en moyenne et il n’existe pas de difference significative entre le cote sain et le cote atteint. Le test d’HA presente un interet limite comme test d’instabilite. Le test d’HA permet d’evaluer la laxite de l’epaule et est correle aux principaux tests de laxite connus.

Unsupported sulfided CoMo, NiMo, CoW and NiW catalysts prepared by comaceration (CM) method and homogeneous sulfide precipitation (HSP) method have been studied in hydrodesulfurization of dibenzothiophene and hydrogenation of biphenyl. Comparison of intrinsic rates shows that, for both reactions, the HSP catalysts are more efficient than the corresponding CM samples. Moreover, the promoting effect of Ni in hydrogenation is substantially higher than that of Co. From decomposition of the precursors, followed by differential thermal analysis, a parallelism appeared between all mixed catalysts prepared by the same procedure. For CM precursors, the decomposition features show the persistence of the character of Mo and W compounds and confirm the limited interaction existing between Co (or Ni) and Mo (or W) in the precursor state. On the contrary, for HSP precursors the exothermic peak is always recorded at a much lower temperature and a comparison with previous results obtained on CoMo (CM) and CoMo (HSP) catalysts suggests that a mixed phase probably exists in all the HSP samples.

Alumina supported NiW catalysts with components concentrations varying in a wide range were systematically studied in order to optimize a catalyst for further industrial uses. The genesis of the active phase was examined by using several physicochemical techniques and the catalytic properties were determined in different reactions characteristic of the hydrotreating process i. e. dibenzothiophene and thiophene HDS, biphenyl and pyridine hydrogenation as well as piperidine HDN. The promoting effect of Ni is always observed but the synergy is greatly dependent on the nature of the molecule to be treated. In addition to these activity determinations, the differences in behaviour towards sulfiding conditions and relationships with probe molecules adsorptions suggest that hydrogenation and hydrogenolysis reactions take place on different catalytic sites. The nature of these sites is discussed in terms of the mixed phase model. The selected most active catalyst for performing HDN reactions was studied for real feedstock conversion. Its activity is compared to the properties of conventional nickel molybdenum and nickel tungsten catalysts.

Unsupported MoS2 (WS2) were prepared by decomposition of ammonium thio-salts, under a flow of H2 + 15 % H2S at 673 K. Samples with surface area ranging from 5 to 80 m2g−1 were tested in hydro-desulfurization of dibenzothiophene and hydrogenation of biphenyl, at moderate temperature (523 - 573 K) and medium high pressure (pT = 22.5 105Pa) conditions. The activity, measured at the pseudo steady state, expressed in mole g−1 sec−1 was found directly proportional to the surface area of the tested catalysts, for both reactions and both types of catalysts. Therefore the preceding reactions appear as “texture insensitive” for both WS2 and MoS2 catalysts.

During the last decade there has been a growing interest in catalytic reactor engineering based on structured catalytic beds. Compared to traditional packed bed reactors, structured catalytic beds provide improved hydrodynamics and catalytic performance. In this context, silicon carbide (SiC) foam materials seems to be a good candidate for use as catalyst support due to their high geometrical surface area (m −1 ) and open porosity leading to low pressure drop. However, foam structures have a relatively low specific surface area (m 2 /g) for performing good anchorage and dispersion of the active phase which is one of the crucial points in catalysis. This study proposes a new type of material which combined the advantage of foam (high porosity) with nanofiber of SiC (high specific surface (m 2 /g)). The knowledge of pressure drop characteristics of foam with nanofiber is necessary for the future process design. However, due to the complexity of the geometric shape of new foam materials, up to date, no general relationship exists for the calculation of the pressure drop through different foam matrix and generally, empirical equation with modified parameters of the Ergun's equation were needed to fit the data. This study show that a simple model can be used for the prediction of the pressure drop in the SiC foam with nanofiber through Ergun's equation without using any fitting in order to reconcile experimental data with theory.

Solid foam matrices have been recently introduced and present a highly permeable porous structure with a high porosity (0.60–0.95), which enables a considerably reduction of the pressure drops along the catalyst bed even with a high specific surface area. It appears today that despite the hydrodynamics of trickle-bed reactors operating with conventional packings (spheres, extrudates, monoliths, etc.) has become largely documented in the recent literature, trickle-bed hydrodynamic behaviour with solid foam packings, on the contrary, largely remains terra incognita. In this context, two phases flows (air–water) in solid foams under cocurrent trickle flow conditions were analyzed in a fixed-bed at ambient conditions. From Residence Time Distribution (RTD) curves, a new set of experimental data based on the hydrodynamics parameters (pressure drop and liquid holdup) of solid foams are presented. A model based on a cubic lattice approach developed in previous work is used to calculate the equivalent diameter for solid foam packings. Finally, through the modified Eotvos number and the relative permeability concept, the two-phase pressure drop and liquid holdup are well estimated. These news results are important parameters for the design of new process in trickle flow conditions with solid foam packing. © 2008 American Institute of Chemical Engineers AIChE J, 2008

In the field of hydrotreating (HDT) catalysis, density functional theory (DFT) calculations are of great help to explore new active phases on the basis of volcano curve relationships correlating HDT activities and the sulfur–metal (S–M) bond energy chemical descriptor, calculated in transition metal sulfides catalysts. In the present study, we synthesize Mo 1− x W x S 2 solid solutions supported on γ-alumina. For non-promoted systems, the catalytic tests reveal that a continuous and linear evolution of the catalytic activity is obtained for solid solutions for x varying between 0 and 1. As expected from the calculated S–M bond energy values, no synergy effect is observed in that case. For Ni and Co promoted Mo 1− x W x S 2 active phases (ternary metal sulfides), the S–M bond energy values determined with an interpolation model of the binary sulfides predict that NiMo 1− x W x S 2 phases should be more active than NiMoS and NiWS ones. In contrast, CoMo 1− x W x S 2 phases are expected to develop weak synergetical effect with respect to CoMoS and CoWS ones. Experiments performed on Co and Ni promoted Mo 1− x W x S 2 active phases confirmed the DFT-volcano curve prediction and an increment of about 30% in HDS catalytic activity is obtained for NiMo 0.5 W 0.5 S catalysts in both model molecule conversion and gas oil treatment.

MICROSCOPIE+ECI2D+MTF:MLA:DGO:MAO:RBA:PAF:CGE; International audience; Hydroconversion of an atmospheric residue (AR) was performed in an autoclave with Mo, Ni, V compounds applied as precursors of the dispersed sulfide catalysts. The reaction was conducted at 450 degrees C, residence time 1 h and the catalyst concentration in the range of 300-900 ppm. AR conversions were compared for the reaction carried out in the presence of sole metals and for the mixtures of two metals. By mixing of the Ni and Mo precursor salts together, improvement in the total conversion and hydrodesulfurization (HDS) degree of the AR was observed, indicating on a significant synergy between Ni and Mo dispersed sulfides. By contrast, in the case of V and Mo precursors mixture the total activity was just a sum of the contributions from two respective metals. With the support provides by high resolution microscopy (HRTEM) and core-hole X-ray absorption spectroscopy (XAS) it was concluded that in the case of mixed Ni-Mo catalyst, MoS2 slabs were deposited on the surface of Ni3S2 crystallites, providing a reverse synergistic effect. (C) 2015 Elsevier Ltd. All rights reserved.

Chronic pulmonary aspergillosis (CPA) complicating sarcoidosis (SA) is associated with high mortality, and there is a lack of clarity regarding the relative contributions of SA or CPA.This was a retrospective single-centre study on CPA-SA.In total, 65 patients (44 men), aged 41.4±13.5 and 48.3±11.9 years at the time of SA and CPA diagnoses, respectively, were included between 1980 and 2015. Of these, 64 had fibrocystic SA, most often advanced, with composite physiological index (CPI) >40 (65% of patients) and pulmonary hypertension (PH) (31%), and 41 patients (63%) were treated for SA (corticosteroids or immunosuppressive drugs). Chronic cavitary pulmonary aspergillosis (CCPA) was the most frequent CPA pattern. Regarding treatment, 55 patients required long-term antifungals, 14 interventional radiology, 11 resection surgery and two transplantation. Nearly half of the patients (27; 41.5%) died (mean age 55.8 years); 73% of the patients achieved 5-year survival and 61% 10-year survival. Death most often resulted from advanced SA and rarely from haemoptysis. CPI, fibrosis extent and PH predicted survival. Comparison with paired healthy controls without CPA did not show any difference in survival, but a higher percentage of patients had high-risk mould exposure.CPA occurs in advanced pulmonary SA. CPA-SA is associated with high mortality due to the underlying advanced SA rather than to the CPA. CPI, fibrosis extent and PH best predict outcome.

The influence of Co on the acidic properties (Lewis and Bronsted) of molybdenum sulfide catalyst were determined by infrared studies of adsorbed pyridine or 2,6-dimethylpyridine. These studies show that the promoter addition increases the strength of the Lewis sites and the number of Bronsted sites. These results are correlated to those obtained for dibenzothiophene conversion. For this reaction, it was observed that the influence of the promoter is very different for the two different routes involved in the reaction scheme. Consequently, the role of the promoter is not only to increase the number of sulfur vacancies but also to modify the acid–base properties of the catalyst.

An oxidic CoMo catalyst presulfided by the SULFICAT® process has been studied by XPS. Results indicate that the strong interaction of the alkylpolysulfide with the solid provokes a partial reduction of both the sulfur and molybdenum ions. Treated under hydrogen, the adsorbed species decompose at temperatures as low as 160–220°C converting the initial Mo 6+ species into sulfided Mo 4+ . The sulfidation state of the active phase increases with the hydrogen pressure. Comparison with the conventional sulfiding procedure indicates that the SULFICAT® process results in a higher dispersion of the sulfided active phase.

The interaction of ammonia with the surface of a model ruthenium sulfide catalyst has been investigated using conventional adsorption measurements, temperature programmed desorption and inelastic neutron scattering. This work has provided evidence that the amount and also the nature of adsorbed species vary with the sulfur to metal ratio of the solid. On the unreduced sample, ammonia interacts weakly with the solid and ammonium ions are not observed. On the partially desulfurized catalyst, the chemisorption of ammonia is dissociative. The NH 2 fragment is bonded to a coordinatively unsaturated ruthenium ion formed upon reduction of the solid while the proton is trapped by a sulfur anion leading to the formation of SH groups. It was previously shown that hydrogen adsorption also involves unsaturated sites. Adsorption of ND 3 , on a hydrogen-covered surface provokes a desorption of HD indicating that a competition of adsorption occurs between hydrogen and ammonia. This result explains why ammonia generally acts as a poison for hydrogenation, hydrodenitrogenation, and hydrodesulfurization reactions.

An in situ time-resolved XRD/XANES/EXAFS investigation combined with on-line evaluation of catalytic performance indicates considerable structural transformations of the conventional Pt-promoted alumina supported cobalt catalyst under the realistic conditions of Fischer–Tropsch synthesis. Cobalt and platinum are reduced into metallic states after pre-treatment in hydrogen at 623 K and form Co–Pt bimetallic nanoparticles. Depending on catalyst and reaction conditions, the metallic nanoparticles can undergo sintering, carbidisation, and fcc–hcp phase transformations. The observed changes in the catalyst structure significantly affect the performance in the Fischer–Tropsch reaction. Cobalt hcp phase seems more active in Fischer–Tropsch synthesis than cobalt fcc metal phase.

The structure of alumina-supported cobalt catalysts promoted with platinum and their catalytic performance in Fischer–Tropsch synthesis were investigated under realistic reaction conditions ( P = 20 bar, T = 493 K) using in situ time-resolved X-ray diffraction with simultaneous analysis of reaction products. The catalysts were prepared via incipient wetness impregnation and characterized by a wide range of ex situ techniques. Direct in situ measurements were indicative of considerable versatility of alumina-supported cobalt catalysts during Fischer–Tropsch synthesis. Cobalt sintering occurred at the first hours of the reaction and resulted in a significant drop of the catalytic activity. In addition to sintering, partially oxidized catalysts containing smaller cobalt particles (mean particle size 2 C cobalt carbide. Cobalt carbidization followed by hydrogenation selectively led to cobalt hcp metallic phase, which seems to be more active in Fischer–Tropsch synthesis than cobalt fcc phase. Cobalt oxidation by water was not significant in the catalysts with metal particles larger than 5 nm even at high water concentrations.

The structure–activity relations in the alumina-supported cobalt catalysts are studied at the realistic conditions of Fischer-Tropsch synthesis using in situ time-resolved XRD and catalytic measurements. Cobalt sintering during the first 3–5 h of the reaction and cobalt carbidisation at a longer time on stream (>8 h) coincide with catalyst deactivation.

Hydrotreating of light and crude petroleum feedstocks involves hydrogenation of unsaturated materials and sulfur, nitrogen, or oxygen heteroatom removals. These main reactions are catalyzed by Co or Ni-promoted molybdenum or tungsten sulfides supported on alumina. Such catalysts may also be required for treating heavier feedstocks containing organically combined metals. Among the different metals present in the feed, Ni and V are the most important ones, which are mainly associated with naphtenates and porphyrins complexes. Sulfide catalysts can break up these organic complexes but unlike the heteroatom removals, the Ni and V are deposited on the catalyst surface. The hydrodesulfurization (HDS), cracking (CK), and hydrodemetallation (HDM) activities decrease as a function of the extra metal loading. This work has shown that the vanadium concentration may reach 50 wt% and despite this high metal level, the catalyst retains a non-negligible activity. Studies tend to show that the residual activity of spent hydrotreating catalyst may be related to the presence of a mixture of vanadium and molybdenum sulfides with a possible influence of a sublayer of Co or Ni chalcogenides. The aim of this work was to investigate the catalytic properties of molybdenum-promoted vanadium sulfide. Special attention was devoted to the preparation andmore » the characterization of the precursor, as well as of the resulting catalysts.« less

International audience; A 2D G-S pseudo-homogeneous steady-state plug flow, non-isobaric and non-isothermal model is used to investigate the effects of operating conditions and catalyst thermal properties on the behaviour of a multi-tubular fixed bed for Fischer–Tropsch synthesis. This simulator allows observing, quantifying and discussing the influences of the gas velocity, the tube diameter, the type of catalyst used (monolithic foam or extrudates) and the heat conductivity of the support (alumina or silicon carbide). The observed responses are the effective thermal parameters of the catalytic bed, the radial and axial temperature profiles and the global performances of the reactor (yield, productivity and selectivity). Thermal properties of the support exhibit a strong influence when low fluid velocities and/or large tube diameters are employed. Because of the high void fraction of a foam structure these effects are less pronounced than with packed beds. This structural difference allows a wider range of operating conditions in terms of fluid velocity and tube diameter but underlines the necessity to tune the void fraction of a foam bed to obtain the best compromise between its volumetric catalytic activity and a good thermal behaviour.