Spelling suggestions: "subject:"hydrodynamic stress"" "subject:"ydrodynamic stress""
1 |
Hydrodynamic stress stimulates growth of cell clusters via the ANXA1/PI3K/AKT axis in colorectal cancer / 流体力学的ストレスはANXA1を誘導し、PI3K/AKTシグナル活性化を介して大腸癌細胞塊の成長を促進するHagihara, Takeshi 23 March 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22374号 / 医博第4615号 / 新制||医||1043(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 武藤 学, 教授 松田 道行, 教授 小西 靖彦 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
|
2 |
Stress response of continued intensification of industrial production processesPlencner, Eric Michael 24 October 2022 (has links)
No description available.
|
3 |
Quantifying the Sensitivity of Land-Surface Models to Hydrodynamic Stress Limitations on TranspirationMatheny, Ashley Michelle 05 July 2013 (has links)
No description available.
|
4 |
Cell Damage Mechanisms and Stress Response in Animal Cell CultureBerdugo, Claudia 25 August 2010 (has links)
No description available.
|
5 |
The effect of hydrodynamic stress on plant embryo developmentSun, Hong 31 March 2010 (has links)
The effect of steady shear stress on somatic embryos were investigated in a flow chamber and evaluated at different time intervals using microscopy technique. The development of meristematic cell clusters, i.e. the immature embryos, into a polarized somatic embryo, and the effect on the localization of the suspensor cells that form during development of the immature embryos, were studied as a function of shear stresses. With the distribution and growth rate of the meristematic and suspensor cells, the effect of stress on the embryo development was established. Furthermore, the effect of shear stress on the cells at molecular level, the reaction of integrin-like proteins, the production of reactive oxygen species and the pore size of the cell walls involved in the shear stress responses, were investigated with molecular techniques.
In general, shear stress inhibits meristematic cells growth. Meristematic cells grow fastest at shear rate of 86 s-1 among all the tested shear stress conditions. By combining the results of meristematic cells growth and suspensor cells formation, it suggests that there is a critical shear rate between 86 and 140 s-1, at which no suspensor cells form. The unidirectional flow with different shear stresses helps the polarized growth and the unidirectional alignment of suspensor cells. Reactive oxygen species and integrin-like protein are detected in the stressed cells as cellular responses to shear stresses. By monitoring the pore size and uptake time of cells to macromolecules with solute-exclusive experiments, it suggests that the stressed cells expedite the response to plasmolyzing components that are used to induce maturation treatment thus affect the response to maturation stimuli.
|
6 |
Investigation of the effect of agricultural spray application equipment on damage to entomopathogenic nematodes - a biological pest control agentFife, Jane Patterson 21 November 2003 (has links)
No description available.
|
7 |
Réponse biologique de cellules animales à des contraintes hydrodynamiques : simulation numérique, expérimentation et modélisation en bioréacteurs de laboratoire / Biological response of animal cell to hydrodynamic stresses : numerical simulation, experimentation and modelling in bench-scale bioreactorsBarbouche, Naziha 13 November 2008 (has links)
La réponse globale de cellules animales à des contraintes hydrodynamiques lors de leur culture en suspension dans des réacteurs agités a été étudiée grâce à une approche intégrative couplant les outils du génie biochimique à ceux de la mécanique des fluides numérique. En premier lieu, la description de l’hydrodynamique moyenne et locale de deux systèmes de culture agités de laboratoire, spinner et bioréacteur, a été réalisée. Puis, l'étude des cinétiques macroscopiques de cellules CHO cultivées en suspension, en milieu sans sérum et sans protéine, a été réalisée avec différentes vitesses d’agitation, pour évaluer l'impact de l'agitation sur les vitesses de croissance et de mort cellulaires, ainsi que de consommation des substrats et de production des métabolites et de l'interféron-gamma recombinant. Des caractérisations supplémentaires des cellules (apoptose, protéines intracellulaires) et de l'interféron ont également été réalisées. Les effets de l'intensification de l'agitation ont été représentés avec plusieurs corrélations globales reliant : (i) en milieu contenant du pluronic, l'intégrale des cellules viables au nombre de Reynolds, et la proportion de cellules lysées à la valeur moyenne de l'énergie de dissipation, <[epsilon]? (ii) en milieu sans pluronic, les vitesses spécifiques de croissance et de mort cellulaires à <[epsilon]. De plus, l'analyse par CFD de la distribution spatio-temporelle des contraintes indique que la lyse cellulaire, observée dans le réacteur aux conditions extrêmes d'agitation, serait plutôt liée à des valeurs locales très élevées de [epsilon], ainsi qu’à la fréquence d'exposition des cellules dans ces zones énergétiques. Un modèle hydro-cinétique original, couplant l’hydrodynamique locale aux cinétiques cellulaires de croissance et de mort, et basé sur l’intermittence de la turbulence permet la prédiction de la lyse massive observée en réacteur sous certaines conditions. Pour confirmer le fait que les effets liés à l'intensification de l'agitation sont bien le résultat d'une augmentation des contraintes hydrodynamiques, et non d'une amélioration du transfert d'oxygène, ce dernier a été mesuré et modélisé par couplage avec une simulation numérique de type Volume Of Fluid , concluant en une absence de limitation d'oxygène. Enfin, la conception, le dimensionnement et la caractérisation hydrodynamique d'un réacteur innovant de type Couette-Taylor, sont proposées pour la mise en œuvre de cultures perfusées dans un environnement hydrodynamique mieux contrôlé / The global response of animal cells to hydrodynamic stress when cultivated in suspension in stirred tank reactors was studied. To do this, an integrative approach coupling biochemical engineering and fluid mechanics tools were used. First, the description of the global and local hydrodynamics of two bench-scale agitated reactors, a spinner flask and a bioreactor, was carried out. Then, macroscopic kinetics of CHO cells cultivated in a serum and protein-free medium were obtained at various agitation rates, in order to evaluate the impact of agitation on cellular growth and death, as well as substrates consumption and metabolites and recombining IFN-[gamma] production. IFN-[gamma] and cells physiological state were more precisely characterised by glycosylation, apoptosis state and intracellular proteins measurements. The effects of the agitation increase were represented by several global correlations that related: (i) in a medium containing Pluronic F68, the Integral of the Viable Cells Density to the Reynolds number, and the proportion of lysed cells with the average value of energy dissipation rate <[epsilon]? (ii) in a medium without pluronic, specific cell growth and death rates to <[epsilon]. Moreover, CFD analysis of the stress distribution indicated that the cellular lysis observed in the bioreactor at the highest agitation rate, would be related to very high local values of [epsilon], and to the exposure frequency of the cells in these energetic zones. An original hydro-kinetic model based on the intermittency of turbulence and coupling the local hydrodynamics with cell growth and death kinetics, allowed the prediction of the massive cell lysis observed in the bioreactor under some mixing conditions. To decouple shear stress effects from oxygen transfer improvement, the oxygen transfer coefficient was experimentally measured and modelled using a Volume Of Fluid numerical simulation. Our results indicated the absence of an oxygen limitation, which confirmed that this cell response resulted from the hydrodynamic stress increase alone. Lastly, an innovative continuous and perfused Couette-Taylor reactor, allowing a better-controlled hydrodynamic environment was designed and sized. Its hydrodynamic description was carried out using CFD calculations
|
Page generated in 0.0765 seconds