Literatura académica sobre el tema "Interaction air-roche"

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

Elija tipo de fuente:

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

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

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

Artículos de revistas sobre el tema "Interaction air-roche"

1

Ingegnoli, F., T. Ubiali, T. Schioppo, V. Longo, S. Iodice, E. G. Favalli, O. De Lucia, A. Murgo, V. Bollati y R. Caporali. "AB0229 SHORT-TERM EXPOSURE TO OUTDOOR AIR POLLUTANTS AND RHEUMATOID ARTHRITIS ACTIVITY IN METROPOLITAN AREAS IN THE NORTH OF ITALY". Annals of the Rheumatic Diseases 79, Suppl 1 (junio de 2020): 1415.1–1415. http://dx.doi.org/10.1136/annrheumdis-2020-eular.2757.

Texto completo
Resumen
Background:Air pollution is believed to cause oxidative stress and systemic inflammation, that could trigger autoimmunity in rheumatoid arthritis (RA). Several epidemiological studies investigated the possible role of air pollution in the outbreak of RA with controversial results. As far as we know, studies on the effects on disease activity of short-term exposure have not been published.Objectives:To evaluate the impact of short-term exposure to air pollutants (daily mean PM10, PM2.5, NO2and O3) on disease activity in patients with RA.Methods:Consecutive patients with RA (ACR/EULAR Criteria 2010) resident in Lombardy (Italy) were enrolled. In each patient Disease Activity Score on 28 joints (DAS28), Simple Disease Activity Index (SDAI) were assessed. Daily PM10, PM2.5, NO2and O3concentrations, estimated by Regional Environmental Protection Agency at municipality resolution, were used to assign short-term exposure from day of visit back to 14 days. Multivariable linear regression models were performed to identify the day of the pollutants independently associated with disease activity indices, adjusting for the variables significant at the univariate analysis. β coefficients were reported for 1 μg/m3increments of pollutants’ concentrations.Results:422 RA patients were enrolled in the study between January and June 2018: 81.5% females, mean age 58.2±13.3 years, mean disease duration 16.1±11.5 years, 27.3% current smokers, 59.5% RF positivity, 54.5% ACPA positivity. Sparse punctual statistically significant negative associations emerged at the multivariate analysis between PM10, PM2.5, NO2and the outcomes, although with very low estimates, whereas positive associations resulted for O3.Afterwards patients were stratified in 3 subgroups according to their ongoing treatment (no therapy, n=25, conventional synthetic Disease Modifying anti-Rheumatic Drugs -DMARDs-, n=108 and biological or targeted synthetic DMARDs, n=289). A statistical significance was found by analysing the influence of therapy on the interaction between PM2.5and DAS28 (Figure below): a positive trend between PM2.5and DAS28 appeared in the first two groups (no therapy, 0.013±0.007, p=0.06 and csDMARDs, 0.006±0.004, p=0.17), whereas a statistically significant inverse association was seen in the b/tsDMARDs group (-0.005±0.002, p=0.01). Therapy interaction was particularly evident in several days before the visit also for O3.Conclusion:The changes of the outcome measures related to the increase of the pollutants’ levels did not reach the minimal clinically important difference, therefore air pollution seems barely relevant on disease activity once the loss of tolerance is established in RA. O3and PM/NO2always exhibit an opposite performance having inversely proportional atmospheric concentrations, whereas the biological role of this substance is still matter of debate and will need further understanding. Therapy seems to be able to interact with the relation between air pollutants and the parameters considered.Disclosure of Interests:Francesca Ingegnoli: None declared, Tania Ubiali: None declared, Tommaso Schioppo: None declared, Valentina Longo: None declared, Simona Iodice: None declared, Ennio Giulio Favalli Consultant of: Consultant and/or speaker for BMS, Eli-Lilly, MSD, UCB, Pfizer, Sanofi-Genzyme, Novartis, and Abbvie, Speakers bureau: Consultant and/or speaker for BMS, Eli-Lilly, MSD, UCB, Pfizer, Sanofi-Genzyme, Novartis, and Abbvie, Orazio De Lucia: None declared, Antonella Murgo: None declared, Valentina Bollati: None declared, Roberto Caporali Consultant of: AbbVie; Gilead Sciences, Inc.; Lilly; Merck Sharp & Dohme; Celgene; Bristol-Myers Squibb; Pfizer; UCB, Speakers bureau: Abbvie; Bristol-Myers Squibb; Celgene; Lilly; Gilead Sciences, Inc; MSD; Pfizer; Roche; UCB
Los estilos APA, Harvard, Vancouver, ISO, etc.
2

Villasboas, Jose C., Patrizia Mondello, Angelo Fama, Melissa C. Larson, Andrew L. Feldman, Zhi-Zhang Yang, Ilia Galkin et al. "High Dimensional Tissue-Based Spatial Analysis of the Tumor Microenvironment of Follicular Lymphoma Reveals Unique Immune Niches inside Malignant Follicles". Blood 136, Supplement 1 (5 de noviembre de 2020): 17–18. http://dx.doi.org/10.1182/blood-2020-134941.

Texto completo
Resumen
Background The importance of the immune system in modulating the trajectory of lymphoma outcomes has been increasingly recognized. We recently showed that CD4+ cells are associated with clinical outcomes in a prospective cohort of almost 500 patients with follicular lymphoma (FL). Specifically, we showed that the absence of CD4+ cells inside follicles was independently associated with increased risk of early clinical failure. These data suggest that the composition, as well as the spatial distribution of immune cells within the tumor microenvironment (TME), play an important role in FL. To further define the architecture of the TME in FL we analyzed a FL tumor section using the Co-Detection by Indexing (CODEX) multiplex immunofluorescence system. Methods An 8-micron section from a formalin-fixed paraffin-embedded block containing a lymph node specimen from a patient with FL was stained with a cocktail of 15 CODEX antibodies. Five regions of interest (ROIs) were imaged using a 20X air objective. Images underwent single-cell segmentation using a Unet neural network, trained on manually segmented cells (Fig 1A). Cell type assignment was done after scaling marker expression and clustering using Phenograph. Each ROI was manually masked to indicate areas inside follicles (IF) and outside follicles (OF). Relative and absolute frequencies of cell types were calculated for each region. Cellular contacts were measured as number and types of cell-cell contacts within two cellular diameters. To identify proximity communities, we clustered cells based on number and type of neighboring masks using Phenograph. The number of cell types and cellular communities were calculated inside and outside follicles after adjustment for total IF and OF areas. The significance of cell contact was measured using a random permutation test. Results We identified 13 unique cell subsets (11 immune, 1 endothelial, 1 unclassified) in the TME of our FL section (Fig. 1A). The unique phenotype of each subset was confirmed using a dimensionality reduction tool (t-SNE). The global composition of the TME varied minimally across ROIs and consisted primarily of B cells, T cells, and macrophages subsets - in decreasing order of frequency. Higher spatial heterogeneity across ROIs was observed in the frequency of T cell subsets in comparison to B cells subsets. Inspecting the spatial distribution of T cell subsets (Fig. 1B), we observed that cytotoxic T cells were primarily located in OF areas, whereas CD4+ T cells were found in both IF and OF areas. Notably, the majority of CD4+ T cells inside the follicles expressed CD45RO (memory phenotype), while most of the CD4+ T cells outside the follicles did not. Statistical analysis of the spatial distribution of CD4+ memory T cell subsets confirmed a significant increase in their frequency inside follicles compared to outside (20.4% vs 11.2%, p < 0.001; Fig. 1D). Cell-cell contact analysis (Fig 1C) showed increased homotypic contact for all cell types. We also found a higher frequency of heterotypic contact between Ki-67+CD4+ memory T cells and Ki-67+ B cells. Pairwise analysis showed these findings were statistically significant, indicating these cells are organized in niches rather than randomly distributed across image. Analysis of cellular communities (Fig. 1C) identified 13 niches, named according to the most frequent type of cell-cell contact. All CD4+ memory T cell subsets were found to belong to the same neighborhood (CD4 Memory community). Analysis of the spatial distribution of this community confirmed that these niches were more frequently located inside follicles rather than outside (26.3±4% vs 0.004%, p < 0.001, Fig. 1D). Conclusions Analysis of the TME using CODEX provides insights on the complex composition and unique architecture of this FL case. Cells were organized in a pattern characterized by (1) high degree of homotypic contact and (2) increased heterotypic interaction between activated B cells and activated CD4+ memory T cells. Spatial analysis of both individual cell subsets and cellular neighborhoods demonstrate a statistically significant increase in CD4+ memory T cells inside malignant follicles. This emerging knowledge about the specific immune-architecture of FL adds mechanistic details to our initial observation around the prognostic value of the TME in this disease. These data support future studies using modulation of the TME as a therapeutic target in FL. Figure 1 Disclosures Galkin: BostonGene: Current Employment, Patents & Royalties. Svekolkin:BostonGene: Current Employment, Current equity holder in private company, Patents & Royalties. Postovalova:BostonGene: Current Employment, Current equity holder in private company. Bagaev:BostonGene: Current Employment, Current equity holder in private company, Patents & Royalties. Ovcharov:BostonGene: Current Employment, Current equity holder in private company, Patents & Royalties. Varlamova:BostonGene: Current Employment, Current equity holder in private company, Patents & Royalties. Novak:Celgene/BMS: Research Funding. Witzig:AbbVie: Consultancy; MorphSys: Consultancy; Incyte: Consultancy; Acerta: Research Funding; Karyopharm Therapeutics: Research Funding; Immune Design: Research Funding; Spectrum: Consultancy; Celgene: Consultancy, Research Funding. Nowakowski:Nanostrings: Research Funding; Seattle Genetics: Consultancy; Curis: Consultancy; Ryvu: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other; Kymera: Consultancy; Denovo: Consultancy; Kite: Consultancy; Celgene/BMS: Consultancy, Research Funding; Roche: Consultancy, Research Funding; MorphoSys: Consultancy, Research Funding. Cerhan:BMS/Celgene: Research Funding; NanoString: Research Funding. Ansell:Trillium: Research Funding; Takeda: Research Funding; Regeneron: Research Funding; Affimed: Research Funding; Seattle Genetics: Research Funding; Bristol Myers Squibb: Research Funding; AI Therapeutics: Research Funding; ADC Therapeutics: Research Funding.
Los estilos APA, Harvard, Vancouver, ISO, etc.
3

Vignon, Christine, Marie-Thérèse Georget, Yves Levern, Elfi Ducrocq, Marie-Christine Bernard, Marie-Hélène Estienne, Dominique Kerboeuf et al. "Bone Marrow Mesenchymal Stromal Cells Regulate the Metabolism of H2O2 In Human Leukemic Cells." Blood 116, n.º 21 (19 de noviembre de 2010): 1058. http://dx.doi.org/10.1182/blood.v116.21.1058.1058.

Texto completo
Resumen
Abstract Abstract 1058 Redox metabolism plays an important role in self-renewal and differentiation of hematopoietic cells and it has been recently established by the Guy Sauvageau's group (Institute for Research in Immunology and Cancer, Montréal, QC) that glutathione peroxydase 3 (GPx-3) promotes competitiveness of Hoxa9-Meis1 induced leukemic stem cells in which Gpx3 overexpression is concomitant of a decrease in H2O2 level and inactivation of p38 MAPK (Herault O et al, ASH annual meeting, 2010 - submitted). Leukemic cells located in the bone marrow (BM) are interacting with a microenvironment which plays a crucial role in the development and progression of leukemia. Mesenchymal stromal cells (MSCs) constitute a population of multipotential cells giving rise to the different hematopoietic microenvironmental cells (adipocytes, osteoblasts, chondrocytes, and vascular-smooth muscle-like hematopoietic supportive stromal cells). The aim of our study was to evaluate the effects of MSC-contact on the GPx-3/H2O2/p38 MAPK axis in human leukemic cells and to assess the cell cycle changes associated with the modification of H2O2 metabolism. BM MSCs were obtained from informed and consenting patients undergoing orthopedic surgery, following a procedure approved by the local ethical committee. Nucleated cells harvested from the iliac crest were seeded (5.104 cells per cm2) in α-MEM supplemented with 10% fetal calf serum (FCS), 20 mmol/l L-glutamine, and 100 units/mL penicillin G. Cells were incubated at 37°C in 95% humidified air and 5% CO2. When fully confluent, the layer of adherent cells was trypsinized (0.25% trypsin-EDTA), and the cells were resuspended in culture medium and seeded at 103 cells per cm2 (passage 1 - P1). BM MSCs were used at P2 in all experiments. The three-lineage mesenchymal differentiation of the BM MSCs used was systematically checked by culturing cells in adipogenic, chondrogenic, and osteogenic induction media as previously described (Delorme et al, Blood 2008, 111:2631). The human KG1a leukemic cell line (FAB M0/M1 CD34+ leukemic cells) was cultured in RPMI 1640 with 20 mmoL/L L-glutamine supplemented with 10% FCS, 100 units/mL penicillin G, and 100 mg/mL streptomycin. KG1a cells were seeded at 1.5 105 cells/cm2 and cocultured with MSCs for 72 h. We have defined two distinct localizations of leukemic cells relative to MSC layer: those in supernatant (non-adherent cells) and cells adhering on the surface of MSCs. The expression of antioxydative enzymes, H2O2 level, p38 MAPK activation (T180/Y182), cell cycle, proliferation and immunophenotype of these two cell fractions were evaluated at day 0 and day 3. The expression of SOD1, SOD2, SOD3, CAT, TXN, TXN2, GLRX, GLRX2, GLRX3, GLRX5, PRDX, PRDX2, PDRX3, PRDX4, PRDX5, PRDX6, GPX1, GPX2, GPX3, GPX4, GPX5, GPX6, GPX7 and GSR antioxydative genes and CDKN1A (p21CIP1) gene was quantified by qRT-PCR (Universal ProbeLibrary, Roche). SDS-PAGE and western-blot experiments were realized to quantify GPx-3 expression and p38 MAPK activation. Flow cytometry studies were performed: (a) to quantify H2O2 level by dichlorodihydrofluorescein diacetate (DCF-DA) staining; (b) to analyze the cell cycle by staining with 7-aminoactinomycin D (7AAD), Alexa Fluor®488-conjugated anti-human Ki67 and Alexa Fluor®488-conjugated anti-phospho-histone H3 (ser10) antibodies; (c) to track the cell divisions with carboxyfluorescein diacetate N-succinimidyl ester (CFSE). Supernatant of MSCs did not modify the GPx-3/H2O2/p38 MAPK axis in KG1a cells. Conversely, when compared with cells in the supernatant of MSCs, adhering KG1a cells were characterized by the exclusive overexpression of GPX3 antioxydative gene, the induction of GPx-3 production, a major decrease in H2O2 concentration and the inactivation of p38 MAPK. These effects were concomitant of cell cycle inhibition: increase in G0 phase, decrease in S and M phase, overexpression of CDKN1A and reduced mitotic activity (CFSE). Altogether these findings suggest that the bone marrow microenvironment plays a key role in the regulation of the oxidative metabolism of leukemic cells by promoting the inhibition of the H2O2/p38 MAPK axis via the induction of GPx-3. Modulation of the GPx-3/H2O2/p38 MAPK pathway by targeting of microenvironmental interactions in leukemia may have clinical relevance and it will be important to verify if these results can be extended in vivo to other models of human leukemias. Disclosures: No relevant conflicts of interest to declare.
Los estilos APA, Harvard, Vancouver, ISO, etc.
4

Wagar, Lisa E., Brian Sworder, Michael S. Khodadoust, Mark M. Davis y Ash A. Alizadeh. "Follicular Lymphoma Organoids for Investigating the Tumor Microenvironment". Blood 134, Supplement_1 (13 de noviembre de 2019): 2799. http://dx.doi.org/10.1182/blood-2019-131192.

Texto completo
Resumen
Background: Current in vitro lymphoma models, including three-dimensional organoids, generally contain exclusively neoplastic lymphocytes and require artificial reconstitution to recapitulate the tumor microenvironment (TME). The co-culture of syngeneic tumor-infiltrating lymphocytes (TILs) alongside endogenous primary malignant lymphocytes could be useful for modeling complex interactions in the TME, and for immunological maneuvers and therapies relying on TILs. However, such conditions for maintaining lymphomas in their syngeneic TME as a cohesive unit have remained elusive. Methods: We adapted an air-liquid interface (ALI) method that we previously described (Neal JT et al 2019 Cell) for propagating patient-derived organoids (PDOs) from primary human follicular lymphomas. Surgically excised lymphoma samples were tested for the ability to maintain lymphoma cell viability in vitro using a lymph node organoid technique. Lymph nodes containing lymphoma cells (and in one case, a PBMC sample including circulating lymphoma cells) were processed into a single cell suspension and frozen until use. Samples were thawed and prepared into immune organoids (see figure). We assessed cell composition by flow cytometry on day 7, and in a subset of samples, up to 21 days post-thaw. Results: A total of 6 patients were profiled for PDO formation, PDO composition and stability, and PDO longevity. 4 of 6 samples showed good cell viability at day 7 post-culture and in a subset of samples, up to 21 days post-culture. Cell composition was well-maintained over time, with presence of lymphoma cells (CD19+ CD10+ CD5-) easily detectable and maintenance of supporting cells of the lymph node such as T follicular helper cells (CD3+ CD4+ CXCR5+ PD-1+) and non-B, non-T cells. Supporting lymph node cells were not detected in the PBMC sample, suggesting the cell composition is related to the initial composition and not due to differentiation in vitro. Genotyping, gene expression phenotyping, and T-cell/B-cell receptor profiling data will be presented at the meeting, including accuracy of PDOs for preserving the original spectrum of these indices. Conclusions: Propagation of PDOs of primary lymphomas with endogenous immune stroma is feasible and maintains cohesive elements of the TME. This system should allow immunoncology investigations within the TME and to facilitate personalized immunotherapy testing. Fig 1: Human lymphoma organoid cultures as a model to study tumor microenvironments and immune responses in vitro. (A) Experimental schema for preparing lymphoma organoids from tumor explants. In an adapted workflow optimized for ex vivo culture of human tonsillar germinal centers (Wagar L et al, submitted), we subject cryopreserved FL samples to organoid culture. (B) An example of follicular lymphoma organoid reorganization in vitro after four days in culture. (C) Total cell viability in FL organoids for up to 21 days in culture. Six samples were tested. (D) Frequency of major cell types in FL samples after organoid culture. Although there is variation among donors' samples, an individual's cell composition is well maintained for at least 14 days in most organoids. Figure 1 Disclosures Khodadoust: Corvus Pharmaceuticals: Research Funding. Davis:Vir Biotechnology: Consultancy, Equity Ownership, Honoraria; PACT Bio: Consultancy, Equity Ownership, Honoraria; Adicet Inc: Consultancy, Equity Ownership, Honoraria; Chuga Pharmabody: Consultancy, Honoraria; Amgen: Consultancy, Research Funding; Atreca: Consultancy, Equity Ownership, Honoraria; Juno: Consultancy, Equity Ownership, Honoraria. Alizadeh:Pfizer: Research Funding; Chugai: Consultancy; Celgene: Consultancy; Gilead: Consultancy; Pharmacyclics: Consultancy; Janssen: Consultancy; Genentech: Consultancy; Roche: Consultancy.
Los estilos APA, Harvard, Vancouver, ISO, etc.
5

Vilor‐Tejedor, Natalia, Armand González Escalante, Blanca Rodríguez‐Fernández, Patricia Genius, Marta Milà‐Alomà, Paula Ortiz‐Romero, Marta Cirach et al. "Sex‐dependent effects on the association between air pollution and longitudinal changes in CSF and plasma biomarkers of Alzheimer’s disease". Alzheimer's & Dementia 19, S22 (diciembre de 2023). http://dx.doi.org/10.1002/alz.078184.

Texto completo
Resumen
AbstractBackgroundA growing body of research links environmental factors with neurodegeneration and premature mortality. However, the biological mechanisms through which the different pollutants may be affecting Alzheimer’s disease (AD) pathology in the early asymptomatic stages of AD and the downstream consequences are unknown. We aimed to evaluate the association between air pollution and longitudinal change rates of cerebrospinal fluid (CSF) and plasma biomarkers of AD in cognitively unimpaired individuals.MethodThe study included 195 middle‐aged cognitively unimpaired participants from the ALFA+ study, many within the Alzheimer’s continuum, with baseline and one follow‐up measurement of biomarkers of primary pathology of AD such as cerebrospinal fluid (CSF) β‐amyloid (Aβ) Aβ42/40 ratio (exploratory Roche NeuroToolKit assays [Roche Diagnostics International Ltd, Rotkreux, Switzerland]), plasma Aβ42/40 (Quanterix Simoa Neurology 4‐Plex E Advantage Kit), and CSF phosphorylated tau181 (p‐tau181) (Roche Elecsys® Phospho‐Tau [181P] CSF assay). Land use regression models were used to estimate individual levels of air pollution, including nitrogen oxide (NO2) and particulate matter (PM2.5, PM10), at the participants’ residential area. General linear models corrected by age, sex, APOE‐ε4 status, and time between measurements were conducted to assess the association between environmental exposures and biomarker changes. Sex‐specific effects were also investigated by including an interaction term.ResultHigher levels of exposure to PM2.5 were significantly associated with greater longitudinal reduction in plasma Aβ42/40 (β = ‐0.188, padjusted = 0.024). In addition, significant interactions between sex and NO2 (padj = 0.016), PM2.5 (padjusted = 0.008), and PM10 (padjusted = 0.007) on longitudinal change rates of plasma Aβ42/40 were found. Results showed that as the level of exposure increased, men presented reductions in plasma Aβ42/40 levels while women did not show significant changes (Figure 1). No significant results were found for longitudinal change rates of CSF biomarkers.ConclusionThese results reinforce the role of air pollution as a sex‐dependent environmental risk factor for AD pathology in asymptomatic individuals. Although more research is needed to elucidate the mechanisms involved in these associations, our results may inform better personalized prediction and prevention practices.
Los estilos APA, Harvard, Vancouver, ISO, etc.
6

Giovanni, Nadia De y Nadia Fucci. "Hypothesis on interferences in kinetic interaction of microparticles in solution (KIMS) technology". Clinical Chemistry and Laboratory Medicine (CCLM) 44, n.º 7 (1 de enero de 2006). http://dx.doi.org/10.1515/cclm.2006.142.

Texto completo
Resumen
AbstractThe present paper describes an evaluation of the interferences found with an immunochemical drug test performed during a workplace control. During the period 1993–2003 more than 200,000 urine samples from workers were examined by the Italian Air Force. Samples were screened for drugs of abuse (opiates, cocaine, cannabinoids, amphetamines, methadone) using an immunochemical technique (Roche, kinetic interaction of microparticles in solution, KIMS). A total of 520 positive samples were sent to the Forensic Toxicology Laboratory for confirmation by gas chromatography/mass spectrometry (GC/MS). Approximately 39% of these were found to be true positives. For the remaining samples, pharmacological therapy in subjects was estimated to evaluate possible interferences due to medicine intake. Our study showed a high frequency of false-positive results with this immunochemical technique, mainly for the cannabinoid and amphetamine groups. Recurrent references to some medicines during subject anamnesis were noted.Clin Chem Lab Med 2006;44;894–7.
Los estilos APA, Harvard, Vancouver, ISO, etc.

Tesis sobre el tema "Interaction air-roche"

1

Sun, Yufeng. "Time-dependent hydromechanical behaviour of callovo-oxfordian claystone by anatytical and multiscale numerical methods". Electronic Thesis or Diss., Vaulx-en-Velin, École nationale des travaux publics de l’État, 2023. http://www.theses.fr/2023ENTP0009.

Texto completo
Resumen
Dans le contexte du stockage géologique profond des déchets radioactifs, le comportement hydromécanique différé de l’argilite du Callovo-Oxfordien (COx) est étudié afin d’assurer les conditions de sûreté requises pour un stockage à long terme de déchets radioactifs. La première partie de l'étude s'appuie sur une approche phénoménologique menée directement à l'échelle macroscopique du matériaux rocheux et des ouvrages souterrains. Dans un premier temps, un modèle quasi-analytique du comportement hydromécanique d'une cavité sphérique profonde creusée dans un massif rocheux dilatant poro-viscoplastique est présenté. Cette modélisation considère trois étapes d'un cycle de vie simplifié de l’ouvrage souterrain : excavation, convergence libre et comportement post-fermeture. Ensuite, le développement, l’extension et l’évolution de la zone rocheuse endommagée par l'excavation (EDZ, Excavation Damaged Zone) sont étudiés à l'aide d’un code aux éléments finis. Cette zone endommagée fait référence à une région caractérisée par des changements importants et pour la plupart irréversibles des propriétés géochimiques et hydromécaniques de la roche. Des analyses de sensibilité et de probabilité sont aussi effectuées pour étudier l’évolution de l'étendue au cours du temps de l’EDZ. Dans la deuxième partie de l'étude, une approche numérique multi-échelles est utilisée pour étudier les effets de fluage et d'endommagement sur le comportement mécanique. Tout d'abord, un modèle basé sur la micromécanique, dans le cadre de modélisation de type éléments finis au carré (EF²), est développé pour modéliser le comportement à long terme de l'argilite du Callovo-Oxfordien. Pour simuler les effets visqueux de la matrice argileuse, deux mécanismes à l’échelle microscopique ont été introduits : la viscoplasticité des agrégats d'argile et la viscoélasticité de leurs contacts. Ensuite, le modèle de comportement de l’argilite du Callovo-Oxfordien développé à petite échelle est appliqué pour modéliser le comportement de fluage à grande échelle, c’est-à-dire à l'échelle du laboratoire et des galeries souterraines. À partir des résultats de simulations à l'échelle du laboratoire, un processus de fluage en trois étapes est reproduit. Il comprend les étapes de fluage primaire, secondaire et tertiaire. A l’échelle des galeries souterraines, l'effet à long terme de la viscosité est étudié sur l'évolution des convergences des galeries et de l'EDZ. Le drainage à long terme et l’évolution de la pression d’eau interstitielle autour d'une galerie sont aussi étudiés. Enfin, le modèle de fluage à double échelle qui a été développé et utilisé pour simuler le comportement de fluage d'une roche fissurée saturée en eau est étendu au cas partiellement saturé. L’objectif est d’étudier l'interaction hydrique entre la roche autour des galeries souterraines et l'air à l’intérieur de celles-ci qui se produit lorsqu’il y a une circulation d’air humide dans les galeries. Les prédictions du modèle reproduisent la cinétique de drainage et de désaturation des roches saines et endommagées
In the context of radioactive waste repository, the time-dependent hydromechanical behaviour of the Callovo-Oxfordian (COx) claystone is investigated to ensure the safety conditions required for long-term repository of radioactive wastes.The first two parts of the study are based on the phenomenological approach carried out directly at the macroscale. Firstly, a quasi-analytical model for the hydromechanical behaviour of a deep spherical cavity excavated in a dilatant poro-viscoplastic rock mass is presented, considering three stages of a simplified life cycle: excavation, free convergence and post-closure. Subsequently, the sensitive and probability analyses are carried out using the finite element code Cast3M toinvestigate the time-dependent extent of the Excavation Damaged Zone (EDZ) which refers to a region characterized by significant and mainly irreversible changes in geochemical and hydromechanical properties. In the following, a multiscale numerical approach is employed to investigate its creep and damage behaviour under mechanical condition. Firstly, a micromechanics-based model within the finite element square (FE2) framework is developed to model the short-term and long-term behaviours of saturated COx claystone. For the viscous behaviour, two microscale mechanisms have been introduced: the viscoplasticity of the clay aggregates and the viscoelasticity of their contacts. Then, the creep model of COx claystones developed at small scale is applied to model the large-scale creep behaviour at laboratory and gallery scales. From simulation results of laboratory scale, a clear three-stage creep process is reproduced, including the primary creep stage, second creep stage and tertiary creep stage. At the gallery scale, the long-term effect of viscosity on the gallery convergences, the evolution of EDZ, and the long-term drainage and pore pressure around a gallery are investigated. Finally, the above developed double-scale creep model used to simulate saturated cracked medium is extend to partial saturated case to study the interaction between rock and the atmosphere occurs through air circulation within underground galleries. The emphasis is to study the effect of the gallery air ventilation on hydromechanical behaviour of host rock. The model predictions reproduce the drainage and desaturation kinetics of undisturbed and damaged rock
Los estilos APA, Harvard, Vancouver, ISO, etc.
Ofrecemos descuentos en todos los planes premium para autores cuyas obras están incluidas en selecciones literarias temáticas. ¡Contáctenos para obtener un código promocional único!

Pasar a la bibliografía