53 research outputs found
Why And How Do Students Need To Have Their Mental Health Considered In Engineering Schools?
This paper addresses the students’ mental health in higher education and more specifically in engineering schools. Several studies have shown student mental health and wellbeing can affect students’ academic performance. We investigate how student’s mental health is considered in engineering schools as well as how it should be and study the case of our engineering school. First, we present several research and studies conducted on how mental health is considered in higher education and its impact on academic performance. In the second part, we study the case of our engineering school with the implementation of a survey among students and teachers to collect their feedback. We add to this survey a collection of testimonies from students. We will analyse how mental health is considered and the impact of addressing mental health on student success in an engineering school. Finally, we present possible solutions to improve the consideration of mental health. These solutions are aimed at administrations, teaching staff and engineering school students. Indeed, the consideration of mental health must be global and concern the entire educational organisation
Trunk Growth in Early-Onset Idiopathic Scoliosis Measured With Biplanar Radiography
Study Design Cross-sectional and longitudinal retrospective study. Objectives To measure thoracic dimensions and volume during growth in early-onset idiopathic scoliosis (EOIS) patients and to compare them to a population of asymptomatic adults and to the previous literature. Summary of Background Data Data on trunk growth for scoliotic children between 6 and 14 years of age is sparse in the literature. Methods Thirty-six patients (29 girls and 7 boys, between 3 and 14 years old, average Cobb angle 33°±15°) were included, all with a minimum two-year follow-up. Sixty-one asymptomatic girls and 54 asymptomatic adults were included as control groups. All subjects underwent biplanar radiography and 3D reconstruction of the spine, pelvis, and rib cage. EOIS patients repeated their radiologic examination every six months. Cobb angle, rib cage volume, anteroposterior and transverse diameters, thoracic index, thoracic perimeter, pelvic incidence, and T1–T12 and T1–S1 distance were calculated. Reproducibility of measurement was assessed. Results Measurement reliability in such young patients was comparable to previous studies in adolescents and adults. Geometrical parameters of EOIS patients increased linearly with age. For instance, rib cage volume in girls with EOIS increased from 2200 cm3 at six to seven years of age to 4100 cm3 at 13–14 years (65% of adult values, 294 cm3/y). Comparison with asymptomatic girls showed that EOIS could affect growth spurt. Longitudinal analysis on a cohort of six girls who had a follow-up of six years confirmed the cross-sectional data. Conclusions In this longitudinal and cross-sectional study, trunk growth between 3 and 14 years of age was characterized, for the first time, with biplanar radiography and 3D reconstruction. The results can be useful to estimate patient growth and thus have potential application in the surgical planning of EOIS patients. Level of Evidence Level II, retrospective study
Theoretical and Experimental Studies of the human Neuroglobin
Le but de cette thèse est de mettre en relation les propriétés structurale, dynamique et fonctionnelle de la forme humaine d’une nouvelle protéine découverte dans le cerveau des vertébrés en 2000 : la Neuroglobine. Dans un premier temps, j’ai réalisé une étude théorique dans laquelle un mécanisme à deux voies menant à la forme pentacoordinée avec cystéines oxydées a été mis en avant. A travers ce mécanisme, un conformère de la Neuroglobine au sein duquel le groupe prosthétique hème a basculé au cœur de la structure protéique a été déterminé. A partir des structures de ce mécanisme, une étude sur la diffusion de petits ligands au sein des cavités internes de la protéine à l’aide de la méthode de métadynamique a mis en évidence que la formation du pont disufure intramoléculaire favorisait la poche de ligation. De plus un certain nombre de voies de sortie pour les ligands a pu être obtenu. Pour compléter ce premier aspect de la thèse, une étude des propriétés mécaniques, communes avec les autres globines, a montré l’importance de quatre résidus centraux, dit mécaniquement sensibles, qui régulent les canaux d’accès aux différentes poches internes de la protéine, appelé phénomène de respiration. Dans un second temps, je me suis intéressé à l’interaction de la Neuroglobine avec un petit ligand via une étude expérimentale par ITC. La première conclusion importante est que la cinétique de ligation est plus importante lorsque le pont disulfure est formé. De plus j’ai observé une diminution de la cinétique lors du passage Wild Type vers C120S puis réaugmentation de la cinétique lors du passage C120S vers C46G/C55S/C120. Afin de comprendre ce phénomène, une simulation de la Neuroglobine triplement mutée a été réalisée au cours de laquelle un réseau de deux liaisons hydrogènes a été mis en avant. Ce réseau change considérablement les voies d’entrée/sortie pour les ligands. Ainsi la mutation 120 ferme une/ou plusieurs voies de sortie alors que la mutation 46 ouvre la voie naturelle des globines. Le changement observé étant important, une étude par RMN de Ngb TM et WT cystéines réduites a montré qu’il y avait une différence de structure entre ces formes pas seulement au niveau des points de mutation mais sur l’ensemble de la structure. Ces nouveaux résultats mettent ainsi en évidence le rôle important des trois cystéines chez la Neuroglobine humaine.In this PhD work, I tried to link together the different structural, dynamic and fonctional properties of a new human protein discovered in the mamals brain in 2000: the Neuroglobin. First of all, I established a new two ways mecanism in order to get the pentacoodinated oxydized cysteins state using theoritical method. One of this mecanism’s conformer shows an important heme sliding inside of the proteic structure. Furthermore with help of metadynamic method, I studied the small ligand diffusion and migration in the internal cavity network. I showed the higher ligand affinity when the disulfide bridge is bond and we proposed an important number of exit pathways. Then we developed a method to understand the mechanical properties of the globins and we found four residues mechanically sensitive which form together a control access pathway between internal cavities, called breath phenomenon. Secondly I used ITC method in order to characterize the interaction between the Neuroglobin and a small ligand. From this experiment we highlighted that the kinetic ligation is faster when the disulfide bridge is formed. Then I noticed a relative decrease of the velocity when the mutation C120S is operated followed by a relative increase of the velocity for the triple mutation C46G/C55S/C120 compared to the Wild Type data. To understand these results, I performed a molecular simulation of the triple mutation Neuroglobin form. During this trajectory, I discovered a structure with a two hydrogen bonds network, which significantly changes the ligand entry/exit pathways. The 120 mutation closes one/several exit pathways while the 46 mutation opens the natural globin exit pathway. Because of the considerable structural change observed in the triple mutation Neuroglobin form, I decided to produce NMR results. These last points reveal a relative structure difference between the Wild Type oxidized cysteins form and the triple mutation form not only on the mutation points but also on the global structure. All these new results highlight the essential role of the three cysteins in the human Neuroglobin
A propos d'une étude de la dimension verticale à l'aide d'une analyse céphalométrique architecturale et orthodontique
LILLE2-BU Santé-Recherche (593502101) / SudocLILLE2-UFR Odontologie (593502202) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF
Etudes theoriques et experimentales de la neuroglobine humaine
Le but de cette thèse est de mettre en relation les propriétés structurale, dynamique et fonctionnelle de la forme humaine d une nouvelle protéine découverte dans le cerveau des vertébrés en 2000 : la Neuroglobine. Dans un premier temps, j ai réalisé une étude théorique dans laquelle un mécanisme à deux voies menant à la forme pentacoordinée avec cystéines oxydées a été mis en avant. A travers ce mécanisme, un conformère de la Neuroglobine au sein duquel le groupe prosthétique hème a basculé au cœur de la structure protéique a été déterminé. A partir des structures de ce mécanisme, une étude sur la diffusion de petits ligands au sein des cavités internes de la protéine à l aide de la méthode de métadynamique a mis en évidence que la formation du pont disufure intramoléculaire favorisait la poche de ligation. De plus un certain nombre de voies de sortie pour les ligands a pu être obtenu. Pour compléter ce premier aspect de la thèse, une étude des propriétés mécaniques, communes avec les autres globines, a montré l importance de quatre résidus centraux, dit mécaniquement sensibles, qui régulent les canaux d accès aux différentes poches internes de la protéine, appelé phénomène de respiration. Dans un second temps, je me suis intéressé à l interaction de la Neuroglobine avec un petit ligand via une étude expérimentale par ITC. La première conclusion importante est que la cinétique de ligation est plus importante lorsque le pont disulfure est formé. De plus j ai observé une diminution de la cinétique lors du passage Wild Type vers C120S puis réaugmentation de la cinétique lors du passage C120S vers C46G/C55S/C120. Afin de comprendre ce phénomène, une simulation de la Neuroglobine triplement mutée a été réalisée au cours de laquelle un réseau de deux liaisons hydrogènes a été mis en avant. Ce réseau change considérablement les voies d entrée/sortie pour les ligands. Ainsi la mutation 120 ferme une/ou plusieurs voies de sortie alors que la mutation 46 ouvre la voie naturelle des globines. Le changement observé étant important, une étude par RMN de Ngb TM et WT cystéines réduites a montré qu il y avait une différence de structure entre ces formes pas seulement au niveau des points de mutation mais sur l ensemble de la structure. Ces nouveaux résultats mettent ainsi en évidence le rôle important des trois cystéines chez la Neuroglobine humaine.In this PhD work, I tried to link together the different structural, dynamic and fonctional properties of a new human protein discovered in the mamals brain in 2000: the Neuroglobin. First of all, I established a new two ways mecanism in order to get the pentacoodinated oxydized cysteins state using theoritical method. One of this mecanism s conformer shows an important heme sliding inside of the proteic structure. Furthermore with help of metadynamic method, I studied the small ligand diffusion and migration in the internal cavity network. I showed the higher ligand affinity when the disulfide bridge is bond and we proposed an important number of exit pathways. Then we developed a method to understand the mechanical properties of the globins and we found four residues mechanically sensitive which form together a control access pathway between internal cavities, called breath phenomenon. Secondly I used ITC method in order to characterize the interaction between the Neuroglobin and a small ligand. From this experiment we highlighted that the kinetic ligation is faster when the disulfide bridge is formed. Then I noticed a relative decrease of the velocity when the mutation C120S is operated followed by a relative increase of the velocity for the triple mutation C46G/C55S/C120 compared to the Wild Type data. To understand these results, I performed a molecular simulation of the triple mutation Neuroglobin form. During this trajectory, I discovered a structure with a two hydrogen bonds network, which significantly changes the ligand entry/exit pathways. The 120 mutation closes one/several exit pathways while the 46 mutation opens the natural globin exit pathway. Because of the considerable structural change observed in the triple mutation Neuroglobin form, I decided to produce NMR results. These last points reveal a relative structure difference between the Wild Type oxidized cysteins form and the triple mutation form not only on the mutation points but also on the global structure. All these new results highlight the essential role of the three cysteins in the human Neuroglobin.PARIS11-SCD-Bib. électronique (914719901) / SudocSudocFranceF
Hypersensibilité dentinaire et agents désensibilisants
TOULOUSE3-BU Santé-Centrale (315552105) / SudocSudocFranceF
Mechanical properties of amorphous and semi-crystalline semi-aromatic polyamides
International audienceWe investigate the mechanical properties of amorphous and semi-crystalline semi-aromatic polyamides, polyphthalamides (PPA). Three relaxation processes have been identified by DMTA which is consistent with literature for polyamide. PPA exhibit a brittle-to-ductile transition from a low impact strength to a high impact strength. At room temperature, all the studied PPA are brittle. During both tensile and compression experiments, a strain hardening behavior is observed for all the studied samples and is more pronounced in compression. The testing temperature has an influence on the strain hardening modulus, contrary to the crystallinity. Strain hardening gives properties of stability and resistance to damage
Effect of intermolecular interactions on the viscoelastic behavior of unentangled polyamide melts
International audienc
Thermoset modified with polyethersulfone: characterization and control of the morphology
International audienceThermoset (TS) epoxy resins can be toughened with a thermoplastic (TP) for high‐performance applications. The final structure morphology has to be controlled to achieve high mechanical properties and high impact resistance. Four polyethersulfone‐modified epoxy resins are considered. They consist of different epoxy monomer structure (TGAP, triglycidyl‐p‐aminophenol and TGDDM, tetraglycidyl diaminodiphenylmethane) and a fixed amount of thermoplastic, and they are cured with two different amounts of curing agent. A reaction‐induced phase separation occurs for all formulations generating morphologies, different in shapes and scales. The aim is to control the final morphology and in particular its dominant length scale. This morphology depends on the phase separation process, from the initiation to its final stage. The initiation relies on the relative miscibility of the components and on the stoichiometry between epoxy and curing agent. The kinetics depends on the viscosity of the systems. The different morphologies are characterized by electron microscopy or neutron scattering. Dynamic mechanical analysis allows confirming the presence of a phase separation even when it is not observable by electron microscopy. Vermicular morphologies with few hundreds nanometer width are obtained for the systems containing the TGAP as epoxy monomer. Systems formulated with TGDDM presents morphologies on much smaller scale of order a few tens of nanometers. We interpret the different sizes of the morphologies as a consequence of a larger viscosity for the TGDDM systems as compared to the TGAP ones rather than by a latter initiation of phase separatio
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