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Дисертації з теми "Analyse radiostéréométrique – Dissertation universitaire":
Khalifé, Marc. "Contribution à l’étude de l’alignement postural global : Analyse du corps entier avec abaques normatifs par la stéréoradiographie et la barycentremétrie." Electronic Thesis or Diss., Paris, HESAM, 2023. http://www.theses.fr/2023HESAE100.
Adult spinal deformities are common pathologies, but their surgical treatment is associated with a high rate of mechanical complications. The aims of this article-based thesis were to identify new anatomical parameters associated with postural alignment, and to redefine reference values for alignment parameters used in clinical practice using stereoradiography and barycentremetry. A cohort of 879 healthy subjects with bi-planar whole-body radiographs was set up. The aim will then be to apply these findings to a population of patients undergoing surgery for adult spinal deformity, and to assess their impact on mechanical complications.The first study showed a correlation between the angle of the upper ribs and the thoracic spine, and between the lower ribs and the lumbar spine. Greater thoracic kyphosis was associated with a greater anteroposterior diameter of the rib cage, and less penetration of the spine, resulting in greater rib cage volume. More interestingly, with regard to global alignment, a compensatory increase in pelvic tilt was found in association with an increase in ribcage width in the sagittal plane.The second study showed a significant correlation between femoral neck version angle and pelvic tilt. This relationship was non-linear, as neck version was comparable in the low and medium pelvic tilt groups, while the group with the highest pelvic tilt had a significantly greater femoral neck version. The findings of this study may suggest that implant orientation in hip replacement surgery should be adapted to the patient's pelvic tilt. Moreover, an association was previously demonstrated between increased femoral version and the risk of hip osteoarthritis and ischiofemoral impingement.Many alignment parameters (pelvic tilt, TPA, SFA, SSA) are physiologically correlated with age, and with pelvic incidence (PI) due to their anatomical definitions. The third study proposes formulas for estimating these four parameters as a function of age and PI. The overall cohort was divided into five groups according to PI, making it possible to provide reference values for all alignment parameters for each group. This study also found that thoracic kyphosis and cervical curvature were not significantly correlated with PI. These results enable a more precise study of postural alignment, taking into account individual patient specificities, for a more patient-specific correction and thus bring a reduction in the risk of postoperative mechanical complications in adult spinal deformity surgery.The barycentremetric study showed that a higher lumbar lordosis was associated with a posterior translation of the body's center of mass above the apex of the thoracic kyphosis. Center of mass analysis also validated the role of the lower limbs in postural alignment. Greater hip extension, pelvic tilt and knee flexion were associated with a posterior translation of the whole-body center of mass. The strong correlation of ODHA with the different centers of mass makes it a good surrogate parameter for estimating the body's line of gravity. A significant association was found between postural alignment and the distance between the spine and the body envelope at the level of lumbar lordosis: a greater distance was associated with pelvic retroversion, as well as an increase in cervical lordosis
Cuffaro, Bernardo. "Analyse fonctionnelle de bactéries du microbiote intestinal humain et évaluation de leurs propriétés bénéfiques contre l’obésité et l’inflammation intestinale." Thesis, Lille 2, 2021. http://www.theses.fr/2021LIL2S007.
Alterations in the gut microbiota composition are suggested to play a role in the development of chronic diseases, including obesity and inflammatory bowel disease (IBD). This dysbiosis leads to the disruption of several key biological processes known to regulate the host physiology, notably the gut barrier integrity and the immune responses leading to a pro-inflammatory state. There is also an alteration in the production of Short Chain Fatty Acids (SCFA), key bacterial metabolites that regulate host metabolism by stimulating the secretion of endocrine peptides. Microbiota-targeting interventions therefore represent interesting tools in the management of chronic diseases. The knowledge on the composition and functions of the gut microbiota has extended the range of microorganisms with potential health benefits. These microorganisms are likely to be fully adapted to the gastrointestinal tract environment and to have important interactions with the host and for these reasons they are being evaluated as next generation probiotics (NGPs). We selected dominant bacteria from the gut microbiota and we checked their robustness to environmental conditions such as oxygen-tolerance and their capacity to survive to gastric stress and observed a strain-dependent capacity. We further characterized their potential beneficial activities using different in vitro models. Most of them were able to induce the release of SCFA in the culture supernatants, mainly acetate and to a lower extend propionate or butyrate. Among the screened strains, a majority was able to restore the gut barrier in an in vitro gut epithelial (Caco-2) barrier model and several strains exhibited an anti-inflammatory potential after human immune cells (PBMC) stimulation and/or were good inducers of GLP-1 after STC-1 endocrine cell line stimulation. Interestingly some ofthem combined several properties. We then evaluated in vivo the most promising strains in different murine models of diet-induced obesity and colitis. We identified three strains exhibited promising abilities against obesity. We also showed a strain-dependent effect of Parabacteroides distasonis strains against colitis and selected three effective strains. These studies provide us better insights on the functionality of commensal bacteria and crucial clues to select next-generation probiotics able to target inflammatory chronic diseases such as obesity and related disorders or IBD
Cuvelliez, Marie. "Analyse des réseaux moléculaires impliqués dans le remodelage ventriculaire gauche post-infarctus du myocarde et dans l’insuffisance cardiaque." Thesis, Lille 2, 2019. http://www.theses.fr/2019LIL2S027.
Nowadays, cardiovascular diseases remain a main public health issue in developed countries.Following a myocardial infarction (MI), at least 30% of patients developed a left ventricularremodeling (LVR), that can lead to heart failure (HF) and to death. The aims of this project were tostudy the mechanisms involved in LVR post-MI and HF and to identify new biomarkers allowing theprediction of a deleterious evolution after MI and early death of HF patients by systems biology andstatistical approaches.First, we built a molecular network based on experimental data obtained in the plasma of post-MI patients of the REVE-2 study at 4 time-points (baseline, 1 month, 3 months and 1 year). An activemodule analysis, extracted at each time-point between patients with LVR and patients without LVR,and a betweenness centrality analysis allowed the selection of 6 molecules potentially involved inLVR : 2 transcription factors, EP300 and ESR1, and 4 microRNAs, miR-335-5p, miR-26b-5p, miR-375 and miR-17-5p. We showed that ESR1 mRNA was significantly increased at 2 months post-MI inthe LV a model of post-MI rats, miR-26b-5p was significantly decreased at 7 days post-MI and miR-335-5p had a trend to increase at 7 days post-MI.Secondly, we built a molecular network using the experimental data obtained by SOMAscanassay, in the plasma of patients diagnosed for systolic HF from the INCA study and followed during 3years. A topological and betweenness centrality analysis allowed the study of the mechanismsinvolved in HF. In parallel, a penalised regression analysis, performed in collaboration with the Bililleplatform, allowed the selection of 6 proteins (C3, MAPKAPK5, Cathepsin S, MMP-1, MMP-7 andFAM107B) that allowed the prediction of early death of HF patients. The quantification of C3, MMP-1 and MMP-7 by conventional assays (ELISA, Luminex) in a subset of the INCA population gaveconsisting results with the SOMAscan assay, but not for cathepsin S
Loisel, François. "Analyse cinématique et biomécanique de la main et du poignet par modélisation personnalisée. Effet de lésions et d’instrumentations." Electronic Thesis or Diss., Paris, HESAM, 2023. http://www.theses.fr/2023HESAE097.
The architecture of the hand and wrist is a complex set of articulations enabling the efficient execution of all the gestures of daily life.Precision of movement and transmission of effector forces require optimal joint congruence and bone cohesion ensured by an organized ligament system.Any trauma resulting in articular step off (fracture) or loss of bone cohesion (ligament rupture) is likely to produce pathological kinematics within these joints. The result is pain, decrease range of motion and impaired overall function. Knowledge of the pathophysiological mechanisms leading to these disorders is essential on several levels: firstly, in a diagnostic context, to be able to identify and treat any injury, even a partial one. Secondly, to improve overall knowledge of the physiological and pathological kinematics of the hand and wrist. And lastly, as part of an innovation drive to propose new solutions (implants) to unresolved problems.The design of customized geometric and biomechanical models in the general context of the study of human joints provides answers to these types of questions. In preliminary work, linked to my Master's research and Stan Durand's thesis, biomechanical tests were carried out on anatomical parts to analyze the effect of a specific implant on the kinematic behavior of the wrist, and to design a method for personalized modeling of the hand and wrist using low-dose biplane X-rays.Following on from this project, this thesis has several objectives.The first objective is to validate our method of personalized hand and wrist modeling in living subjects, by comparing it with the reference technique of TDM segmentation.Secondly, we will apply this method to create a corridor of physiological displacement of certain carpal bones of interest (scaphoid, lunate, triquetrum), between two reference positions (wrist in neutral position or closed fist) among a population of volunteers free of ligament lesions. This corridor of normality is useful for comparing physiological and pathological displacements in clinical practice.Indeed, the third objective is to compare carpal kinematic data from patients with infra-radiological ligament lesions with this corridor of normality. The aim is to assess the diagnostic capabilities of the customized model. By analyzing pre- and post-operative data, a feasibility study will also investigate the field of objective follow-up of surgical restoration by suture or ligament re-anchoring.The aim of such a study is therefore to use geometric, kinematic and biomechanical models of the hand and wrist to assess normal and pathological kinematics (diagnosis), and to analyze current surgical implants in order to propose areas for improvement
Jourdain, Marie-Laure. "Analyse phénotypique et fonctionnelle des ostéoclastes et de leurs précurseurs dans la maladie osseuse liée à la mucoviscidose Inflammation and CFTR-related bone remodeling in patients in cystic fibrosis CFTR-deficient pigs display alterations of bone microarchitecture and composition at birth Overexpression of RANKL in osteoblasts: a possible mechanism of susceptibility to bone disease in cystic fibrosis." Thesis, Reims, 2019. http://www.theses.fr/2019REIMO201.
The increasing life expectancy of patients with cystic fibrosis (CF) is associated with extra-pulmonary complications which prevalence increases with age, such as bone disease or diabetes, that impact the quality of life of CF patients. The bone deficit related to cystic fibrosis is still incompletely characterized and the understanding of the impact of CFTR (Cystic Fibrosis Transmembrane conductance Regulator) defect on bone physiology is essential to propose new therapeutic strategies. The most common mutation of CFTR, (F508del) in osteoblasts is associated with a high RANK-L/OPG ratio that may stimulate osteoclastogenesis. The aim of this work was to study the impact of CFTR defective activity on osteoclast precursors and their differentiation as well as the functional activity of CF osteoclasts. We have demonstrated that there is an overexpression of the RANK and M-CSF receptors on the surface of osteoclastic precursors derived from patients carrying the CFTR G551D mutation. Furthermore, we have revealed that the osteoclasts phenotype is strongly impacted by the F508del mutation as well as the S1P pathway, a prominent mediator for the circulation of osteoclastic precursors between blood and bone compartments. All of these data and the demonstration of a disturbed resorptive osteoclasts profile when CFTR activity is deficient suggest that there is a dysregulation of resorption and more widely of bone remodeling in CF patients
Georgel, Anne-France. "Analyse des réponses anti-bactériennes et anti-virales respiratoires induites par les agonistes des récepteurs de l’immunité innée." Thesis, Lille 2, 2018. http://www.theses.fr/2018LIL2S053.
Viral and bacterial infections remain a burden for health care systems. The current therapeutic approaches by antibiotic have shown their effectiveness but also their limit especially in cases of multidrug-resistant microorganisms or in the treatment of patients with aggravating pathologies. Stimulation of innate immunity could be a complementary therapeutic approach to current treatments. Indeed, the activation of the innate immune system induces local production of antimicrobial molecules and the recruitment of effector cells involved in controlling infection.The Toll-like Receptors (TLRs) are innate sensors that trigger signaling cascades and promotes the archetypal pro-inflammatory responses involved in antimicrobial defense. TLR5 recognizes flagellin, the structural protein of bacterial flagella. TLR5 is expressed on the surface of macrophages, dendritic cells and epithelial cells.In the first part of the work, we assessed the ability of flagellin to control the replication of influenza A virus H3N2. We first showed that intranasal or systemic administration of flagellin activated transcription of anti-viral genes in lung tissue. Administration of flagellin reduced viral replication in the lung of mice infected with H3N2 IAV. This effect is also observed in Il22-/- and Ifnar-/- mice suggesting a mechanism independent of type I interferon and interleukin 22 signaling. Finally, we also showed that the combination of flagellin with oseltamivir (neuraminidase inhibitor) was more efficacious than standalone treatments.The second part of this work is the ASTRAL clinical study, which assesses the ability of blood mononuclear cells to respond to different TLR agonists in patients with acute lobar pneumonia. This study started in October 2017 and plans to include 38 patients. The objective is to observe the response after TLR agonist stimulation by transcriptional analysis and cytokine assays. The first results (analysis of 7 patients) show that blood mononuclear cells can be activated by TLR agonists in the context of pneumonia
Lespagnol, Elodie. "Impact du diabète de type 1 sur la vasoréactivité et la variabilité de la fréquence cardiaque au repos et en réponse à l’exercice aigu." Thesis, Lille 2, 2020. http://www.theses.fr/2020LIL2S003.
Despite intensive insulin treatment and advanced techniques of glucose self-monitoring, hyperglycemia and hypoglycemia are frequent complications in type 1 diabetes. Chronic hyperglycemia may contribute to early alterations in endothelial function and in cardiac autonomic activity. The literature about endothelial dysfunction is very large and sometimes contradictory but suggests that endothelial dysfunction can be evidenced during exercise. The underlying mechanisms of the altered vasoreactivity to exercise remain to be explored but may involve a decrease in the bioavailability of the main vasodilating molecule: nitric oxide (NO). In addition, chronic hyperglycemia but also acute hyper or hypoglycemic excursions may alter cardiac autonomic activity, even in patients with still uncomplicated type 1 diabetes. This manifests by a decrease in heart rate variability and in one of its components, the parasympathetic tone. Although regular exercise is recognized in non-diabetic populations to improve heart rate variability, the challenge for people with T1D may lie in the occurrence of exercise-induced hypoglycemic episodes, with a possible negative impact on parasympathetic tone. The objectives of this PhD were : 1) a systematic analysis of the literature throughout a meta-analysis, to study the presence or not of endothelial dysfunction in persons with type 1 diabetes compared to persons without diabetes, 2) investigating some molecular mechanisms underlying exercise-induced impairment in muscle vasoreactivity and finally, 3) studying the impact of a multi-day sustained cycling exercise on cardiac autonomic activity in athletes with type 1 diabetes, while considering glycemic excursions. The results show that 1) people with type 1 diabetes, albeit still free from overt micro- and macrovascular complications, have indeed an early endothelial dysfunction but also an alteration in the vascular smooth muscles function. The endothelial dysfunction was evidenced in response to various stimuli (exercise, occlusion-reperfusion, pharmacological substances or heat). Nevertheless, standardisation of methods would make the results less heterogeneous and help in the follow-up of endothelial dysfunction. 2) Alteration in muscle vasoreactivity to maximal exercise might be the consequence of a decrease in the availability of L-Arginine, the exclusive substrate of enzymatic NO synthesis. In addition, a decrease in the major circulating antioxidant, uric acid, is possibly involved, while vitamins, total free thiols and erythrocyte enzymatic antioxidant defences appear normal. 3) amateur athletes with type 1 diabetes show an increase in the time spent in hyperglycemia, but not hypoglycemia, in response to the unusual multi-day moderate-to-intense exercise, with possible deleterious impact on their nocturnal parasympathetic cardiac tone. In view of all these results, it appears therefore crucial to find non-pharmacological alternatives in an attempt to improve early endothelial and cardiac autonomic activity disorders
Vuillod, Bruno. "Stratégie de modélisation multi-fidélité via une approche système incluant des métamodèles basés sur les entités NURBS." Electronic Thesis or Diss., Paris, HESAM, 2024. http://www.theses.fr/2024HESAE003.
The more complex the problem, the greater the amount of computational resources needed to simulate it. On the other hand, the need for accuracy in the results of a system will not be the same depending on its design phase and the domain studied. The goal of this thesis is to propose a fast, low-cost multi-fidelity modeling strategy. To meet this need, a hybrid modeling approach is developed that combines Model-Based System Engineering (MBSE) and a metamodel based on Non-Uniform Rational Basis-Spline (NURBS) hypersurfaces. More specifically, the scientific challenge of this work is to develop a metamodel based on NURBS entities to simulate the behavior of highly nonlinear systems that require high fidelity modeling but are capable of providing results in real time to be compatible with the MBSE approach. In this context, the NURBS entity-based metamodel is obtained as a solution to an optimization problem solved with a gradient algorithm. In addition, a smoothing term is included in the problem formulation, not only to reduce the influence of any spurious nonlinearities in the training database, but also to limit the phenomenon of overfitting. The technical and scientific challenge of this work is to couple the general MBSE approach with the NURBS-based metamodel
Houzé, de l'Aulnoit Agathe. "Acquisition du rythme cardiaque fœtal et analyse de données pour la recherche de facteurs prédictifs de l’acidose fœtale." Thesis, Lille, 2019. http://www.theses.fr/2019LIL2S007.
Visual analysis of the fetal heart rate FHR is a good method for screening for fetal hypoxia but is not sufficiently specific. The visual morphological analysis of the FHR during labor is subject to inter- and intra-observer variability – particularly when the FHR is abnormal. Underestimating the severity of an FHR leads to undue risk-taking for the fetus with an increase in morbidity and mortality and overvaluation leads to unnecessary obstetric intervention with an increased rate of caesarean section. This last point also induces a French public health problem.FHR automated analysis reduces inter and intra-individual variability and accesses other calculated parameters aimed at increasing the diagnostic value. The FHR morphological analysis parameters (baseline, number of accelerations, number and typing of decelerations, long-term variability (LTV)) were described as well as others such as the decelerations surfaces, short-term variability (STV) and frequency analyzes. Nevertheless, when attempting to analyze the FHR automatically, the main problem is computation of the baseline against which all the other parameters are determined.Automatic analysis provides information on parameters that cannot be derived in a visual analysis and that are likely to improve screening for fetal acidosis during labor.The main objective of the thesis is to establish a predictive model of fetal acidosis from a FHR automated analysis. The secondary objective is to determine the relevance of the classical basic parameters (CNGOF 2007) (baseline, variability, accelerations, decelerations) and that of other parameters inaccessible to the eye (indices of short-term variability, surfaces of decelerations, frequency analysis ...). Later, we want to identify decision criteria that will help in the obstetric care management.We propose to validate FHR automated analysis during labor through a case-control study; cases were FHR recordings of neonatal acidosis (arterial cord pH less than or equal to 7.15) and controls, FHR recordings of neonatal without acidosis (arterial cord pH upper than or equal to 7.25). This is a monocentric study at the maternity hospital of Saint Vincent de Paul Hospital, GHICL - Lille, on our « Well Born » database (digital archiving of RCF plots since 2011), with a sufficient number of cases on this only center. Since 2011, the Saint Vincent de Paul hospital (GHICL) has had about 70 cases per year of neonatal acidosis (pHa less than or equal to 7.10) (3.41%). The R software will be used for statistical analysis
Poissenot, arrigoni Corentin. "Identification inverse du comportement thermomécanique à partir des champs cinématiques et thermique mesurés dans la zone de cisaillement primaire en rabotage : application à l'Inconel 718." Electronic Thesis or Diss., Paris, HESAM, 2023. http://www.theses.fr/2023HESAE089.
The shaping process through machining involves severe thermomechanical loading, potentially leading to deformations and local changes in the properties of the machined material. These undesired consequences of cutting are quite common in nickel-based alloys, as this material family exhibits good mechanical properties at high temperatures. Currently, simulation tools could potentially predict the consequences of machining on the integrity of the finished piece; however, no test or methodology allows for the complete determination of material behavior laws with gradients and thermomechanical kinetics representative of those induced by a machining operation. In the overall perspective of strengthening confidence in machining process simulations, the objective of this thesis is to develop an innovative methodology for the inverse identification of thermomechanical behavior and damage laws of nickel-based alloy materials under machining conditions.To achieve this, in a first step, preparatory work for the deployment of measurements through infrared thermography is proposed. An innovative method for calibration insensitive to integration times for sensors cooled in indium antimonide has been developed. Additionally, to convert radiometric temperatures of the observed scene into absolute temperatures, a method for the direct measurement of emissivity based on the use of a multispectral camera has been developed. Subsequently, an image processing method has been developed, allowing for obtaining comprehensive thermal information about the cut for low and high magnification objectives. Finally, a study of measurement errors induced by thermography, based on a radiometric model, has been proposed.In a second step, an extensively instrumented planing experiment allowing the observation of kinematic and thermal fields has been designed. A triaxial dynamometric plate enables the acquisition of cutting forces, and an optical system, based on wavelength separation, allows simultaneous observation of the cut through visible and infrared cameras through a single lens. An analysis of images from the visible camera using digital image correlation provides access to kinematic fields, and a specific treatment of images from the infrared camera provides a mapping of the thermal field during cutting. With the collected data, an analysis of the characteristics of the primary shear zone could be conducted, including an estimation of the dimensions of the deformed material zone and the temperatures reached.In a third step, a numerical model simulating the thermomechanical field induced by an orthogonal cutting operation has been developed. To optimize computation time, a sensitivity study of mesh size and the number of cores allocated to the calculation has been conducted. Finally, a sensitivity study of input parameters for the simulation has highlighted the most influential parameters on the thermomechanical field.Ultimately, leveraging experimental and simulated kinematic and thermal behaviors within the primary shear zone induced by cutting, an inverse identification algorithm has been developed. This algorithm aims to determine the constants of the Johnson-Cook plasticity and damage behavior laws (the chosen thermomechanical behavior model for this study) of the machined material under cutting conditions. The algorithm also incorporates indicators of the discrepancy between experimental and simulated results for each measured quantity, providing a confidence indicator for the identified material constants.In conclusion, through precise instrumentation, the kinematic and thermal fields applied to the workpiece during planing have been observed and quantified. These experimental data have subsequently fueled an inverse identification algorithm, enabling the determination of material constants for Johnson-Cook behavior and damage laws under cutting conditions