Dissertations / Theses on the topic 'Fats modification'
To see the other types of publications on this topic, follow the link: Fats modification.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 34 dissertations / theses for your research on the topic 'Fats modification.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
BARLETTA, LUCA. "Random enzymatic interesterification of Palm Olein for future industrial applications." Doctoral thesis, Politecnico di Torino, 2014. http://hdl.handle.net/11583/2528299.
Full textAbstract:
This thesis has been focused on random enzymatic interesterification of Palm Olein, in order to obtain a material equivalent to chemically interesterified one, operating in milder conditions of temperature, and at sustainable price.
The research project has been started with the study of state of art of enzymatic interesterification and properties of enzymes; preliminary tests (conducted in laboratory batch
reactor) have been allowed the evaluation of the features of random enzymatically interesterified Palm Olein, the study of the kinetics of the reaction and the choice of operating parameters for subsequent tests in continuous laboratory reactor. Last step of the research activity, in order to apply in future the process on industrial scale, was the transfer to bench scale to pilot
scale. In order to do this, a design of pilot plant has been realized, scaling up the bench continuous reactor.
2
Smith, Leanna Marie. "Fast Corn Grading System Verification and Modification." OpenSIUC, 2012. https://opensiuc.lib.siu.edu/theses/795.
Full textAbstract:
A fast corn grading system can replace the traditional method in unofficial corn grading locations. The initial design of the system proved that it can classify corn kernels with a high success rate. This study tested the robustness of the system against samples from different locations with different moisture contents. The experimental results were compared with the official grading results for 3 out of the 6 samples. This study also tested the limitations of the segmentation algorithm. The results showed that 60 to 70 kernels in a 100 cm2 could be correctly segmented in a relatively short running time. Classification accuracy would improve with modifications to the system, including increased training samples of damaged kernels, uniform illumination, color calibration, and improved weight approximation of the kernels.
3
Rajah, Kanes K. "Fractionation of milk fat." Thesis, University of Reading, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233844.
Full text
4
Shi, Chuan. "Protein Modification and Catabolic Fates of Lipid Peroxidation Products." Case Western Reserve University School of Graduate Studies / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=case1481231287497328.
Full text
5
Campbell, Pearl. "Pou5f1 Post-translational Modifications Modulate Gene Expression and Cell Fate." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23607.
Full textAbstract:
Embryonic stem cells (ESCs) are characterized by their unlimited capacity for self-renewal and the ability to contribute to every lineage of the developing embryo. The promoters of developmentally regulated loci within these cells are marked by coincident epigenetic modifications of gene activation and repression, termed bivalent domains. Trithorax group (TrxG) and Polycomb Group (PcG) proteins respectively place these epigenetic marks on chromatin and extensively colocalize with Oct4 in ESCs. Although it appears that these cells are poised and ready for differentiation, the switch that permits this transition is critically held in check. The derepression of bivalent domains upon knockdown of Oct4 or PcG underscores their respective roles in maintaining the pluripotent state through epigenetic regulation of chromatin structure. The mechanisms that facilitate the recruitment and retention of Oct4, TrxG, and PcG proteins at developmentally regulated loci to maintain the pluripotent state, however, remain unknown. Oct4 may function as either a transcriptional activator or repressor. Prevailing thought holds that both of these activities are required to maintain the pluripotent state through activation of genes implicated in pluripotency and cell-cycle control with concomitant repression of genes required for differentiation and lineage-specific differentiation. More recent evidence however, suggests that the activator function of Oct4 may play a more critical role in maintaining the pluripotent state (Hammachi et al., 2012). The purpose of the studies described in this dissertation was to clarify the underlying mechanisms by which Oct4 functions in transcriptional activation and repression. By so doing, we wished to contextualize its role in pluripotent cells, and to provide insight into how changes in Oct4 function might account for its ability to facilitate cell fate transitions. As a result of our studies we find that Oct4 function is dependent upon post-translational modifications (PTMs). We find through a combination of experimental approaches, including genome-wide microarray analysis, bioinformatics, chromatin immunoprecipitation, functional molecular, and biochemical analyses, that in the pluripotent state Oct4, Akt, and Hmgb2 participate in a regulatory feedback loop. Akt-mediated phosphorylation of Oct4 facilitates interaction with PcG recruiter Hmgb2. Consequently, Hmgb2 functions as a context dependent modulator of Akt and Oct4 function, promoting transcriptional poise at Oct4 bound loci. Sumoylation of Oct4 is then required to maintain Hmgb2 enrichment at repressed loci and to transmit the H3K27me3 mark in daughter progeny. The expression of Oct4 phosphorylation mutants however, leads to Akt inactivation and initiates the DNA Damage Checkpoint response. Our results suggest that this may subsequently facilitate chromatin reorganization and cell fate transitions. In summary, our results suggest that controlled modulation of Oct4, Akt, and Hmgb2 function is required to maintain pluripotency and for the faithful induction of transcriptional programs required for lineage specific differentiation.
6
Hudson, Oliver Thomas. "Polymer modification of fast growing woods for improved mechanical response and sustainable architecture." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610241.
Full text
7
Pugsley, Gustavo de Revorêdo. "O efeito modificativo do fato jurídico sobre a relação jurídica obrigacional." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/2/2131/tde-12042015-180612/.
Full textAbstract:
A doutrina costuma apontar como efeitos dos fatos jurídicos a criação, a modificação ou a extinção de relações jurídicas. Os textos doutrinários normalmente desenvolvem o estudo dos fatos jurídicos que criam relações jurídicas; o presente trabalho, porém, se dedica aos fatos jurídicos tendentes a modificar relações jurídicas anteriormente criadas, restringindo-se ao campo das obrigações. Primeiramente, deve-se buscar um critério: modificação do direito isolado ou da relação jurídica? Como nas relações jurídicas complexas há diversos direitos e deveres recíprocos, a extinção de um direito pode levar apenas à modificação da relação jurídica integralmente considerada. Se Savigny já entendia que um juízo acerca do direito só pode ser verdadeiro quando fundado na compreensão completa da relação jurídica, hoje há renovadas razões para que se adote um critério relacional: a relação obrigacional tem sido vista como um processo, o que leva a um reforço de sua identidade com a inclusão de um elemento finalístico. As ideias de modificação e identidade estão vinculadas, pois, se a \"modificação\" leva à perda da identidade, a relação jurídica na verdade foi extinta. Quanto ao tema das modificações, a maior parte da doutrina parece tratar apenas da \"transmissão das obrigações\". Outros, ao lado dessas modificações subjetivas, tratam de modificações objetivas, normalmente restringindo-se às efetuadas por negócio jurídico. A classificação de Pontes de Miranda, porém, parece servir de referencial para o presente trabalho: quanto às modificações \"sem quebra da identidade da relação jurídica\", o autor aponta modificações negociais, alterações por dolo e culpa, por força maior e caso fortuito, por impossibilidade de adimplemento e, por fim, por mora do devedor e do credor.Current legal theory generally considers the effects of legal facts (those resulting from the correlation between facts and norms) on the creation, modification or termination of legal relationships. While most authors addresses how legal facts create these relationships, the present study is devoted to legal facts tending to modify the legal relationship, particularly in the field of the Law of Obligations (duty to perform). At first, a criterion must be determined: modification of the isolated right or modification of the Obligation? In \"complex\" obligational relationships, there are many mutual rights and duties, such that the extinction of a right can result only in the modification of the relationship fully considered. Long ago, Savigny asserted that a reasonable analysis of a right must be based on a thorough understanding of the legal relationship at issue. There are now renewed reasons to adopt these relational criteria when analyzing legal relationships. The obligational relationship may be seen as a process, which leads to the reinforcement of its identity with the inclusion of a finalistic element. The ideas of modification and identity are linked, because if a \"change\" leads to the loss of identity, the legal relationship may, in fact, have been terminated. Most of the authors on the subject of modifications addresses the \"transfer of obligations\". Some other studies, beside these subjective modifications, addresses objective modifications, usually restricted to those made by agreement. The \"Pontes de Miranda\" classification, may serve as a useful reference when analyzing the issue of modifications. The author points to modifications by agreement, changes by dolus and culpa (fault, tort law and breach of contract), by force majeure or unforeseeable circumstances, impossibility of performance, and, ultimately, by the mora debitoris and mora creditoris/accipiendi (default, delay of performance) as modifications \"without breaking the identity of the legal relationship\".
8
Christopher, Bridgette A. "The Influence of Myofilament Protein Modification and Myocardial Insulin Resistance on Pathologic Left Ventricular Function." Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1296007529.
Full text
9
Stoilova, Bilyana. "Structural plasticity and post-translational modifications of C/EBP beta direct distinct myeloid cell fates." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2013. http://dx.doi.org/10.18452/16742.
Full textAbstract:
Der CCAAT enhancer binding protein beta (C/EBPβ) Transkriptionsfaktor reguliert die Differenzierung, Proliferation und Funktion vieler Zelltypen, einschließlich verschiedener Zellen des Immunsystems. Eine detaillierte molekulare Analyse des Mechanismus, wie C/EBPβ alternative Zellschicksale steuert, wurde jedoch bisher noch nicht unternommen. Es wurde gezeigt, dass die ektopische Expression von C/EBPβ in determinierten B- Vorläuferzellen diese zu inflammatorischen Makrophagen reprogrammieren kann. Wir haben dieses Reprogrammierungsystem verwendet, um die Strukturelemente in C/EBPβ, die für die Regulation der (Trans)Differenzierung durch C/EBPβ wichtig sind, zu untersuchen. Um die maßgeblichen C/EBPβ Proteinmodule für die Reprogrammierung zu bestimmen, wurden entweder C/EBPβ Wildtyp Isoformen oder Mutanten in primären murinen B-Vorläuferzellen ektopisch exprimiert. Die Analysen ergaben, dass die translational regulierten langen Isoformen LAP* and LAP, jedoch nicht die kurze Isoform LIP lymphoide Zellen zu myeloischen Zellen reprogrammieren können. Des weiteren haben wir gezeigt, dass die konservierten Regionen 2, 3 und 4 der C/EBPβ Transaktivierungsdomäne essentiell und ausreichend für die Konvertierung von B Zellen zu myeloischen Zellen sind. Die reprogrammierten myeloischen Zellen setzten sich aus einer heterogenen Population verschiedener myeloischer Zelltypen zusammen. Detaillierte Analysen von CD11b+ reprogrammierten Zellen zeigten, dass diskrete konservierte Regionen von C/EBPβ verschiedene pro- und anti-inflammatorische Gene und divergente Entwicklungsprogramme aktivierten. Des Weiteren führten nicht nur strukturelle C/EBPβ Mutanten sondern auch Puktmutationen an Stellen, die posttranslationalen Modifikationen (PTM) unterliegen, zu verschiedenen Reprogrammierungsergebnissen. Diese Daten zeigen, dass die C/EBPβ abhängige myeloische Diversifikation durch die Integration von strukturellen C/EBPβ Proteinmodulen und deren signalabhängigen PTMs erreicht wird.The CCAAT enhancer binding protein beta (C/EBPβ) transcription factor regulates differentiation, proliferation, and functionality of many cell types, including various cells of the immune system. A detailed molecular understanding of how C/EBPβ directs alternative cell fates remains largely elusive. Ectopic expression of C/EBPβ has been previously shown to reprogram committed B cell progenitors into inflammatory macrophages. We took advantage of this reprogramming system in order to examine how C/EBPβ regulates (trans)differentiation. To determine which C/EBPβ protein modules are important for reprogramming, C/EBPβ wild type isoforms and mutants were ectopically expressed in primary mouse B cell progenitors. The data showed that the translationally regulated long isoforms LAP* and LAP, but not the N-terminally truncated isoform LIP can reprogram lymphoid cells into myeloid cells. Furthermore, we found that conserved regions 2,3 and 4 in the C/EBPβ protein transactivation domain are necessary and sufficient for B-to-myeloid cell conversion. Interestingly, the reprogrammed myeloid cells were found to represent a heterogeneous mixture of different myeloid cell types. Detailed analyses of the reprogrammed CD11b+ cells revealed that discrete conserved regions in C/EBPβ activated distinct pro- and anti-inflammatory genes and triggered divergent differentiation programs. Moreover, not only structural C/EBPβ mutants, but also post-translational modification (PTM) site mutations led to different reprogramming outcomes. These data suggest that C/EBPβ orchestrates myeloid diversification by integrating PTMs with structural plasticity as signal dependent adaptable modular properties to determine cell fate.
10
Guecha, Lopez Carlos Alfonso. "La modification du contrat administratif en droit colombien." Thesis, Paris 2, 2015. http://www.theses.fr/2015PA020037/document.
Full textAbstract:
Bien que la modification du contrat administratif soit par principe libre, elle ne peut s’exercer que dans le cadre de certaines limites. En France, les règles de publicité et mise en concurrence imposent des conditions de fond, de forme et de procédure qui déterminent la légalité de l’instrument modificatif. L’interdiction d’un objet nouveau, les restrictions au bouleversement de l’économie du contrat, la fixation des seuils par le juge, etc. révèlent un contrôle rigoureux des modifications. En Colombie, par contre, il semble que la liberté des parties est beaucoup plus étendue. Un seuil général de cinquante pour cent du montant initial, la possibilité des parties de bouleverser l’économie du contrat et même la modification fondamentale de l’objet, font partie d’un système juridique qui tend à supprimer toutes les restrictions à la volonté des parties à l’égard de la modification. S’il est même de l’essence du contrat administratif d’admettre des modifications aux conditions fixées initialement, un sujet d’une grande importance sera celui de la nature de la modification en droit colombien pour dévoiler tous les défis de sa mise en oeuvreAlthough the modification of the public contract is in principle free, it can only take place under certain limitations. In France, the rules of advertising and competition impose substantive conditions of form and procedure to determine the legality of the modifying instrument. The prohibition of agreeing to a new object, restrictions on altering the economic balance, setting financial thresholds, etc., reveal a rigorous control for any modifications. In Colombia, however, it appears that the freedom of the parties is much broader. A general threshold of fifty percent of the initial price, the possibility of altering the economics of the contract and even the fundamental modification of the object, are part of a legal system that tends to abolish all restrictions to the will of the parties regarding modification. Although it is of the essence of contract modifications to disclose the conditions initially established, a major theme is that of the nature of the change in Colombian law to reveal all the challenges of its implementation
11
Jarymowycz, Virginia A. "Studies of the influence of structural modifications or binding on the fast time scale dynamics of proteins." [Bloomington, Ind.] : Indiana University, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3322532.
Full textAbstract:
Thesis (Ph. D.)--Indiana University, Dept. of Interdisciplinary Biochemistry Program, 2007.Title from PDF t.p. (viewed May 8, 2009). Source: Dissertation Abstracts International, Volume: 69-07, Section: B, page: 4156. Adviser: Martin J. Stone.
12
Чобіт, М. Р., В. П. Васильєв, and Ю. В. Панченко. "Модифікація поверхні крейди відпрацьованими рослинними жирами." Thesis, Cумський державний університет, 2016. http://essuir.sumdu.edu.ua/handle/123456789/46388.
Full textAbstract:
Розвиток промисловості вимагає створення нових полімерних матеріалів з наперед
заданими властивостями. Необхідні властивості найбільш легко досягаються
створенням наповнених полімерних (композиційних) матеріалів. Значною перевагою
полімерних композиційних матеріалів перед традиційно використовуваними
матеріалами є: застосування дешевої сировини, яка має потужну базу, економія
полімерного зв´язуючого, покращення технологічних і споживчих властивостей
матеріалів.
13
Alan, Salih. "Development Of A Fast Analytical Method For Prediction Of Part Dynamics In Machining Stability Analysis." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/2/12611096/index.pdf.
Full textAbstract:
The objective of this study is to develop and implement practical and accurate methods for prediction of the workpiece dynamics during a complete machining cycle of the workpiece, so that FRFs of the workpiece can be used in chatter stability analysis. For this purpose, a structural modification method is used since it is an efficient tool for updating FRFs due to structural modifications. The removed mass is considered as a structural modification to the finished workpiece in order to determine the FRFs at different stages of the process. The method is implemented in a computer code and demonstrated on representative parts such as turbine blades. The predictions are compared and verified with the data obtained using FEA. The FRFs are used in chatter stability analyses, and the effect of part dynamics on stability is studied.
14
Reeves, Valerie Lynn. "A DIET ENRICHED IN STEARIC ACID PROTECTS AGAINST THE PROGRESSION OF TYPE 2 DIABETES IN LEPTIN RECEPTOR DEFICIENT MICE (DB/DB)." UKnowledge, 2012. http://uknowledge.uky.edu/physiology_etds/3.
Full textAbstract:
Dietary saturated fat intake contributes to diabetes and cardiovascular disease, as shown in numerous animal and human studies. However, the hypothesis that stearic acid, a saturated fat, has beneficial effects on these conditions has not been adequately tested. Leptin receptor deficient mice (db/db) and wild-type mice were fed either chow or a high fat diet enriched in either stearic acid or oleic acid for ten weeks. The progression of diabetes was evaluated with blood glucose, insulin, and metabolic parameter measurements. At the conclusion of the study, pancreatic islet organization was examined, and blood, liver and feces were assayed for fatty acid content.
The stearic acid enriched diet prevented increases in blood glucose levels independently of weight loss in db/db mice compared to an oleic acid or chow diet. Diabetic mice fed stearic acid maintained insulin responsiveness and pancreatic islet organization compared to the db/db mice fed chow and oleic diets. The islet organization of the stearic acid fed mice did not change over the course of the study and was similar to that of wild-type mice fed the same diet. Conversely, diabetic mice fed oleic acid and chow diets had decreased insulin responsiveness and disorganized islets. Stearic acid fed db/db mice had high fecal fat content and caloric intake calculations indicated low absorption of this fat.
Switching to stearic acid after prolonged hyperglycemia had a rescue effect on blood glucose levels. After feeding diabetic and wild-type mice standard chow diets for 6, 8, and 10 weeks to establish hyperglycemia, mice switched to a high fat diet enriched in stearic acid, but not one enriched in oleic acid diet, had significant reductions in blood glucose levels.
The ability of a stearic acid enriched high fat diet to slow the progression of diabetes and reverse hyperglycemia in db/db mice argues that risks and benefits of fats in the diet depend on the chemical structure, rather than the chemical class, of fats ingested. The beneficial effect of stearic acid appears to be associated with a decreased absorption of dietary fat.
15
Lou, Ruding. "Modification of semantically enriched FE mesh models : Application to the fast prototyping of alternative solutions in the context of industrial maintenance." Paris, ENSAM, 2010. http://www.theses.fr/2010ENAMA017.
Full textAbstract:
La simulation numérique de comportement des futurs produits est largement utilisée sur les modèles virtuels de produits avant leur fabrication physique. Cependant, le processus pourrait encore être optimisé en particulier pendant la phase d'optimisation du comportement de produit. Ce processus implique la répétition de quatre étapes principales de traitement : conception de CAO, création de maillage, enrichissement de sémantique par la modélisation du comportement physique et enfin calcul par éléments finis (EF). L'analyse de comportement de produit est effectuée à partir de la première solution de conception puis sur les nombreuses boucles successives d'optimisation de produit. Chaque évaluation de solution nécessite le même volume de temps que celui nécessaire pour la première conception de produit, cela est particulièrement crucial dans le contexte de maintenance de produit et d'évaluation de cycle de vie de produit. Cette thèse propose un nouveau cadre de travail pour l'optimisation de produit à partir de simulation par EF menées successivement sans retour à la CAO initiale du produit, ce qui réduit les activités de préparation de maillages et d'enrichissement sémantique E. F. Plus concrètement, l'idée est d'opérer directement le maillage enrichi par la sémantique E. F pour optimiser le produit. Dans cette thèse, les concepts sous-jacents et les composants conçus pour le développement de ces opérateurs de modification sont présentés et analysés. Une spécification d'opérateur de haut niveau est proposée selon une structure modulaire qui permet ensuite une réalisation facile des différents opérateurs de modification de maillage. Enfin, quatre déclinaisons de cet opérateur de maillage de haut niveau sont présentées: la fusion, la fissuration, le perçage et le congé d'arête. Ces opérateurs ont été prototypés et validés sur des modèles E. F. Académiques et industriels, permettant de démontrer leur efficacité et la pertinence de l'approche proposéeBehaviour analysis is largely performed on the virtual model of the product before its physical manufacturing. Anyhow, the process could be further optimised especially during the product behaviour optimisation phase. This process involves repetition of four main processing steps: CAD design, mesh creation, enrichment of physical semantics and Finite Element Analysis (FEA). The product behaviour analysis is performed on the first design solution as well as on the numerous successive product optimisation loops. Each design solution evaluation necessitates the same time as required for the first product design and it is particularly crucial in the context of maintenance and lifecycle assessment. This thesis proposes a new framework for CAD-less product optimisation through FEA, which reduces the mesh preparation and semantics enrichment activities. More concretely, the idea is to directly operate the firstly created FE mesh, enriched with semantics, to perform the product modifications required to achieve its optimised version. In this thesis, the underlying concepts and the devised components for the development of such CAD-less operator are discussed. A high-level operator specification is proposed according to a modular structure that allows an easy realisation of different mesh modification operators. Finally, four instances of this high-level operator are described: merging, cracking, drilling and filleting. These operators are prototyped and validated on academic and industrial FE mesh models, thus clearly showing the feasibility of our approach
16
Adam, Mohammed A. "Fate of the transferrin receptor during in vitro maturation of sheep reticulocytes and post-translational modifications of the transferrin receptor." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=70354.
Full textAbstract:
The transferrin receptor is a membrane protein which is involved in the binding and endocytosis of transferrin, the main Fe$ sp{3+}$ carrying protein. The receptor and transferrin function to provide cells with iron, an essential nutrient. As red cells mature and lose their ability to make hemoglobin, they also lose their capacity to bind transferrin and take up iron. The transferrin receptor in sheep reticulocytes has been shown to undergo externalization in vesicular form during maturation of sheep reticulocytes in vitro. Microscopic studies show that the receptor is internalized into endosomes and externalization, in vesicular form, occurs via formation of multivesicular elements (or bodies), which ultimately fuse with plasma membranes releasing the inclusion vesicles bearing the transferrin receptor. The released receptor seems intact, having the same molecular weight and $ sp{125}$I-iodo-tyrosyl tryptic peptide map as the native receptor. The externalized receptor can also bind transferrin and the anti-receptor antibody.The transferrin receptor can be fatty acylated and phosphorylated in intact cells and in isolated plasma membranes. The phosphorylation of the receptor is not affected by the binding of transferrin or anti-transferrin receptor antibody. However, $ beta$-phorbol esters can stimulate the phosphorylation of the receptor suggesting that protein kinase C may be responsible for receptor phosphorylation. During reticulocyte maturation, the externalized transferrin receptor is not phosphorylated. Furthermore, the ability of this externalized receptor to undergo phosphorylation by protein kinase C is also lost, suggesting a maturation induced change in the receptor compared to the cell associated receptor. This change may be a signal which determines whether the transferrin receptor is to be segregated for externalization during red cell maturation or recycled for iron delivery.
17
Torcal, Garcia Guillem 1991. "Methylation of a lineage-instructive transcription factor acts as a cell fate switch." Doctoral thesis, TDX (Tesis Doctorals en Xarxa), 2022. http://hdl.handle.net/10803/673532.
Full textAbstract:
Lineage-instructive transcription factors orchestrate cell fate decisions by regulating gene expression programs. However, how their function is regulated throughout development is poorly understood. C/EBPα is a transcription factor that has been shown to play a key role in several cell fate decisions of several tissues, including myelopoiesis, adipogenesis and early embryo development. The protein arginine methyltransferase Carm1 has also been described to play a role in cell specification during various developmental processes, but a connection to C/EBPα has not been established. In this Thesis, we investigated the link between the two proteins in cell fate decisions. We found that arginine 35 of C/EBPα is a key target of Carm1 methylation, and that this post-translational modification alters the biological properties of the factor and acts as a cell fate switch during myelopoiesis, adipogenesis and the first cell fate decision between pluripotency and trophectoderm in early embryos.Los factores de transcripción instructores de linaje orquestan decisiones de identidad celular a través de la regulación de programas de expresión génica. Sin embargo, cómo su función está regulada durante el desarrollo todavía se desconoce. C/EBPα es un factor de transcripción que juega un papel clave en varias decisiones de identidad celular, incluyendo mielopoiesis, adipogénesis y el desarrollo embrionario temprano. La metiltransferasa de argininas Carm1 también está involucrada en los mismos procesos, pero todavía no se ha descrito una posible conexión con C/EBPα. En esta Tesis, hemos investigado la conexión entre éstas dos proteínas en decisiones de identidad celular. Hemos descubierto que la arginina 35 de C/EBPα es un blanco clave para la metilación por Carm1, y está modificación postraduccional altera las propiedades biológicas del factor y actúa como un interruptor de identidad celular en mielopoiesis, adipogénesis y en la primera decisión entre pluripotencia y trofectodermo en el embrión.
18
Чобіт, М. Р., В. Л. Костюк, В. П. Васильєв, and Ю. В. Панченко. "Модифікація жировмісними відходами мінеральних наповнювачів." Thesis, Сумський державний університет, 2016. http://essuir.sumdu.edu.ua/handle/123456789/52779.
Full textAbstract:
Розвиток сучасної промисловості вимагає створення нових полімерних композитних матеріалів. Полімерні композити володіють значною перевагою перед іншими матеріалами, а саме: дешевизна та потужна виробнича база, економія полімерного зв´язуючого, покращення властивостей одержаних матеріалів. Одержання композитів із задовільними властивостями обмежуються протиріччями між механічними властивостями і поверхневими енергіями наповнювача і полімерної матриці.
19
McDaniel, Lori Heldreth. "Investigation of Liquid Trapping Following Supercritical Fluid Extraction." Diss., Virginia Tech, 1999. http://hdl.handle.net/10919/29121.
Full textAbstract:
Supercritical fluid extraction (SFE) is an alternative to traditional extractions with organic solvents. SFE consists of removing the analyte(s) from the matrix, solubilizing them, moving the analyte(s) into the bulk fluid, and sweeping the fluid containing the analyte(s) out of the extraction vessel.
As the fluid leaves the extraction vessel, decompression of the fluid occurs, changing its volume and temperature which can lead to analyte loss.
This work focussed on the trapping process with the restrictor immersed in a liquid after SFE. Experiments compared the effects of trapping parameters on the collection efficiencies of fat-soluble vitamins of similar polarities and structures. The most important variable was the selection of collection solvent and its physical properties, such as viscosity, surface tension and density were found to be important.
Additionally, adding a modifier to the collection solvent in an attempt to change its physical properties and influence collection efficiencies for a polarity test mix was studied. Addition of a modifier can improve collection efficiencies and allow higher collection temperature to be used, but the modifier did not increase trapping recoveries to the extent that collection pressurization did.
The occurrence of a methylation reaction of decanoic acid during the SFE and collection processes, using a methanol modified fluid or collection solvent was investigated. The majority of the reaction occurred during the collection process and the degree of methylation was found to be dependent on temperature, but not on static or dynamic extraction time. When no additional acidic catalyst other than carbon dioxide in the presence of water was present, conversion was limited to about 2%, but was quantitative with an added acidic catalyst.
The last portion of this work involved the application of the SFE process to the extraction and analysis of extractable material in eight hardwood and softwood pulp samples. Grinding the samples increased extractable fatty acid methyl esters (FAMEs) by ten-fold, and in-situ derivatizations resulted in higher FAME recoveries than derivatization after SFE. Liquid trapping enhanced recoveries of lower FAMEs when compared to tandem (solid/liquid) trapping. In-situ acetylations sometimes yielded acetylated glucoses. Large differences in FAMEs concentrations were seen for hardwood samples, but lesser differences were seen for the softwood pulp samples.Ph. D.
20
Bouhlal, Sofia. "Consequence of salt, sugar and fat content modifications in foods on children's preference and intake." Thesis, Dijon, 2011. http://www.theses.fr/2011DIJOS110/document.
Full textAbstract:
Contexte : En France, le Programme National Nutrition Santé (PNNS) est en charge d’appliquer les recommandations visant à diminutions les quantités de sel, de sucre et de matières grasses dans les aliments. Cependant, l’effet de ces réductions sur les préférences et les consommations est mal connu. Objectifs : Ce travail vise à comprendre l'impact des variations de sel, de sucre et de matières graisses dans les aliments, sur les préférences et les consommations alimentaires des enfants.Méthodes : Des études ont été menées dans l’environnement habituel du repas des enfants (crèche ou cantine scolaire), aux heures normalement prévue pour le déjeuner et / ou le goûter.Résultats : Concernant le saccharose, l'ajout d'une faible quantité paraît suffisant pour induire un prise alimentaire; ainsi, le saccharose peut être réduit sans affecter les préférences ni les consommations alimentaires. Dans la mesure où le gras est concerné, la suppression ou l’ajout de beurre n'a pas eu un impact immédiat sur la consommation des haricots verts ou celle des pâtes. Quant aux produits allégés en matière grasse, ils semblent être bien acceptés par les enfants et les adultes. Concernant le sel, sa réduction semble plus délicate et devrait donc être considérée avec prudence. Par ailleurs, nos résultats mettent en évidence la dissociation entre l'effet positif et directe du sel sur les préférences et les consommations d’un côté, et son rôle sur l'apprentissage de l’autre.Conclusions : Les qualités sensorielles des aliments sont importantes pour le comportement alimentaire. Cependant, alors qu’il semblerait que des réductions de sucre et de gras sont possibles, contribuant ainsi à réduire l'apport énergétique, celles concernant le sel doivent être considérées avec prudenceBackground: In France, the National Nutrition and Health Programme (“Programme National Nutrition Santé” or “PNNS”) is in charge of implementing the recommendations aiming at reducing salt, sugar and fat quantities in foods. However, the extent to which this might impact children’s food preferences and intake is limited. Objective: The present work aimed at understanding the impact of varying salt, sugar and fat variations in foods, on toddlers and children’s food preferences and intake. Methods: Studies were conducted in toddlers’ and children’s natural eating environment (nursery and school canteen), at their usually scheduled lunch and/or snack times. Results: Concerning sucrose, the addition of a low amount seems enough to trigger intake; thus, sucrose can be reduced without affecting food preferences and intake. As far as fat is concerned, suppressing or adding butter did not have an immediate impact on toddlers’ green beans or pasta intake. Besides, low-fat products seem to be well accepted by toddlers and adults. Concerning salt, its reduction seems more puzzling and should be considered cautiously. Our results highlighted dissociation between the direct positive effect of salt on food preferences and intake, and its role on learning. Conclusions: Food sensory qualities are important for eating behaviour. Although it seems that reductions of sugar and fat in foods are possible, thus helping to reduce energy intake, those concerning salt should be considered cautiously
21
Stoilova, Bilyana [Verfasser], Achim Akademischer Betreuer] Leutz, Klaus [Akademischer Betreuer] Rajewsky, and Thomas [Akademischer Betreuer] [Sommer. "Structural plasticity and post-translational modifications of C/EBP beta direct distinct myeloid cell fates / Bilyana Stoilova. Gutachter: Achim Leutz ; Klaus Rajewsky ; Thomas Sommer." Berlin : Humboldt Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2013. http://d-nb.info/103545095X/34.
Full text
22
Maurel, Delphine. "Consommation chronique d'alcool, exercice physique et tissu osseux : modifications densitométriques, architecturales, biomécaniques et métaboliques chez le rat." Phd thesis, Université d'Orléans, 2011. http://tel.archives-ouvertes.fr/tel-00789948.
Full textAbstract:
La consommation d'alcool a des effets sur le tissu osseux. L'alcoolisme est une des causes d'ostéoporose secondaire chez l'homme. Dans ce travail nous avons mené différentes expérimentations chez le rat afin d'étudier les effets d'une consommation chronique d'alcool combinée ou non à un entraînement aérobie sur le tissu osseux. Nous avons montré qu'une faible dose d'alcool administrée pendant une période courte peut avoir un effet positif sur la densité minérale osseuse et l'épaisseur trabéculaire. En revanche, la combinaison activité physique et consommation modérée d'alcool n'a pas d'effet additif sur la potentialisation du tissu osseux. Nous avons également démontré un effet dose de l'alcool indiquant des effets délétères majorés sur la densité minérale osseuse (DMO), la microarchitecture corticale et la résistance osseuse avec des apports croissants (25%, 30% et 35% v/v). La modification de DMO s'accompagne d'un changement de composition corporelle et d'une diminution de la leptine systémique. Cependant, le nombre d'adipocytes augmente dans la moelle osseuse. Nous avons mis en évidence dans ce modèle d'ostéoporose secondaire due à l'alcool une augmentation de l'apoptose des ostéocytes, corrélée à la diminution de la DMO et à l'augmentation de l'adiposité médullaire. Nous avons de plus mis en évidence une incorporation de lipides dans les ostéocytes, incorporation fortement corrélée à l'apoptose de ces cellules. Enfin, nos résultats montrent qu'un exercice physique régulier combiné à une consommation chronique et excessive d'alcool permet de prévenir les effets délétères de l'alcool sur les paramètres osseux (porosité corticale, épaisseur corticale) et limite la diminution de la DMO. Cette diminution est associée à une régulation de l'apoptose des ostéocytes.
23
Pascart, Tristan. "Étude des modifications osseuses de composition et de structure au cours de l’ostéonécrose de tête fémorale et corrélations étiopathogéniques IRM." Thesis, Lille 2, 2017. http://www.theses.fr/2017LIL2S049/document.
Full textAbstract:
La physiopathologie et l'évolution structurale de l'ostéonécrose de tête fémorale (ONTF) sont des processus encore largement méconnus. Les objectifs de cette thèse ont été de rechercher des modifications de composition et de structure de l'os trabéculaire et de l'os sous-chondral dans l'ONTF. Un travail préliminaire s'est intéressé aux modifications de composition osseuse en spectrométrie Raman induites par l'embaumement afin de déterminer les témoins les plus appropriés pour comparer les os pathologiques. Des tissus osseux fémoraux issus de 5 sujets anatomiques embaumés ont ainsi été comparés à ceux de 5 sujets anatomiques frais. Le premier travail sur l'ONTF a consisté à rechercher des modifications des paramètres physico-chimiques minéraux et organiques en spectrométrie Raman de l'os trabéculaire de tête fémorale chez 11 patients ayant une ONTF versus 11 sujets frais. Le second travail concernant l'ONTF a porté sur l'étude de l'os sous-chondral. Cette recherche a prévu l'inclusion de 15 patients ayant une ONTF à 15 patients ayant une coxarthrose nécessitant un remplacement prothétique. Une évaluation IRM avec séquences usuelles, séquences de perfusion et séquences DIXON était réalisée préalablement à la chirurgie. Après la chirurgie, l'ensemble de la tête fémorale était ensuite analysé en nano-scanner (nano-CT), puis des biopsies en zones d'intérêt ont été réalisées et analysées par histologie, nano-CT avec amplificateur de contraste et spectrométrie Raman.RésultatsLa composition des tissus osseux fémoraux des sujets anatomiques frais et embaumés différaient de manière significative sur les paramètres minéraux et organiques. La composition de l'os trabéculaire sur les zones d’intérêt ne différait pas entre les patients ayant une ONTF et le groupe de sujets anatomiques frais après ajustement sur l'âge. Le volume de nécrose définie en IRM par la zone en hyposignal T1 est corrélé au volume de nécrose incluant la zone sclérotique en nano-CT. Concernant l'os sous-chondral, les résultats préliminaires mettent en évidence des différences de composition minérale et organique en spectrométrie Raman au niveau de la plaque souschondrale entre les zones d’intérêt du groupe ONTF et avec le groupe coxarthrose. Les résultats préliminaires qualitatifs des biopsies en nano-CT et en histologie suggèrent que l'atteinte de la plaque sous-chondrale est prédominante sur celle de l'os trabéculaire souschondral. L’évaluation IRM (séquence DIXON) et en nano-CT de la richesse adipeuse suggère une relative pauvreté adipeuse de la tête fémorale mais une richesse excessive du col fémoral.Ce travail apporte des éléments supplémentaires suggérant que la désorganisation de l'os trabéculaire au cours de l'ONTF est une conséquence d'une atteinte massive de l'os sous-chondralIntroductionThe pathophysiology and structural evolution of the osteonecrosis of the femoral head (ONFH) are poorly understood. The objectives of this thesis were to search for modifications of composition and structure of both the trabecular and the subchondral bone occurring during ONFH.MethodsA preliminary study looked into the potential modifications of bone composition induced by embalmment procedures using Raman spectroscopy in order to determine which controls are the most appropriate for comparisons with pathological bones. Femoral bones from 5 embalmed anatomical subjects were compared to femoral bones from 5 subjects that did not undergo any preservation procedure. The first work on ONFH addressed the potential modifications of trabecular bone mineral and organic physico-chemical parameters using Raman spectroscopy. The study included bone samples from femoral heads of 11 patients affected with ONFH and compared them to samples from 11 fresh anatomical subjects. The second study on ONFH addressed modifications of the subchondral bone. The study included 15 patients suffering from ONFH and 15 patients affected with hip osteoarthritis (OA) requiring joint prosthetic replacement. MRI examination that included standard medical sequences as well as experimental perfusion and DIXON sequences was performed prior to surgery. Once removed, the femoral heads were scanned using a nano-CT and samples of regions of interest were performed and analysed using histology, nano-CT with contrastenhancer marking and Raman spectroscopy.ResultsBone femoral mineral and organic composition was significantly altered in embalmed samples. Trabecular bone composition did not differ in any of the regions of interest inside the group of patients with ONFH nor in comparison with the control group of embalmed subjects after adjustment on age. The volume of the necrotic zone defined by the hypo-T1 MRI signal correlates to the volume including the sclerotic zone measured by nano-CT. Regarding the subchondral bone, preliminary results found differences of mineral and organic composition of the subchondral plate between zones of the ONFH group and with the OA group. Qualitative preliminary results from the study of biopsies analysed with the nano-CT and histology suggest that there are alterations of the subchondral plate and of the subchondral trabecular bone to a lesser extent. MRI examination with the DIXON sequence and nano-CT scans suggest that there is a decrease of the adipose content in the femoral head but an increase in the femoral neck in the ONFH group compared to the OA group.ConclusionThis work adds further evidence advocating that trabecular disorganization during ONFH is a consequence of massive alterations of the subchondral bone
24
Trebuchet, Guillaume. "Etude des mécanismes de la différenciation cellulaire impliquant le facteur de transcription Glide/Gcm chez la drosophile." Thesis, Strasbourg, 2014. http://www.theses.fr/2014STRAJ114/document.
Full textAbstract:
La différenciation cellulaire implique des facteurs clés. Chez la drosophile, le facteur de transcription Glide/Gcm est impliqué dans la différenciation de deux types de cellules immunitaires : les macrophages circulants, qui ont une origine hématopoïétique, et les cellules gliales, macrophages résidents du système nerveux central, qui sont issues des précurseurs neuraux. J'ai d'abord entrepris la caractérisation du potentiel hématopoïétique de Gcm et l'identification de ses cibles dans les hémocytes. Ensuite, pour comprendre comment plusieurs types cellulaires peuvent être spécifiés par un même facteur de transcription, j'ai étudié comment s'effectue le choix entre le destin glial et le destin hémocytaire de la cellule. J'ai en particulier misen évidence le rôle clé des gènes agissant en aval de Gcm, ceux impliqués dans la consolidation et le maintien de l'identité cellulaire. Finalement, j'ai participé à la caractérisation du territoire d'expression de Gcm au niveau protéique et découvert un nouveau rôle de Gcm dans la différenciation de cellules neurosécrétrices, cellules indispensable pour initier le signal hormonal déclenchant le phénomène de mue chez les insectesCell fate determination involves key transcription factors. ln Drosophila, the transcription factor Glide/Gcm is required for the differentiation of two immune cell types: circulating macrophages,which arise from hematopoietic precursors, and glial cells, resident macrophages of the central nervous system, which differentiate from neural precursors. ln first, 1 characterized Gcm hematopoietic potential and identified its target genes in hemocytes. Then, to get an insight intomolecular mechanisms underlying the acquisition of several identities with a single fate determinant, 1 investigated how the choice between the hemocyte and the glial fates is regulated.Being necessary to consolidate and to maintain a specific fate, 1 highlight the key role of genes acting downstream of a fate determinant. Finally, 1 contribute to characterize Gcm expression profile at the protein level and highlight a new role of Gcm in the differentiation of neurosecretory cells, cells absolutely required to initiate the hormonal signal triggering the molting process in insects
25
Reddy, Yella S. "Studies on modification of fats of tree-origin for use in confectionery." Thesis, 1988. http://hdl.handle.net/2009/1963.
Full text
26
Sadeqzadeh, Elham. "Analysis of post-translational modifications of Fat1 cadherin." Thesis, 2014. http://hdl.handle.net/1959.13/1050575.
Full textAbstract:
Research Doctorate - Doctor of Philoshphy (PhD)First identified in Drosophila as a tumour-suppressor gene, Fat cadherin (Ft) and the closely related Fat2 (Ft2) have been identified as giant members of the cadherin superfamily. Ft engages the Hippo signalling pathway during development and both receptors have been shown to function in different aspects of cell polarity and migration. There are four vertebrate homologues, Fat1-Fat4, all closely-related in structure to Drosophila ft and ft2. Over the past decade knock-out mouse studies, genetic manipulation and large sequencing projects have aided our understanding of the function of vertebrate Fat cadherins in tissue development and disease. The majority of studies of this family have focused on Fat1, with evidence now showing it can bind to ENA/VASP, β-catenin and Atrophin proteins to influence cell polarity and motility; Homer1 and 3 proteins to regulate actin accumulation in neuronal synapses; and Scribble to influence the Hippo signalling pathway. Fat2 and Fat3 can regulate cell migration in a tissue specific manner and Fat4 appears to influence both planar cell polarity and Hippo signalling recapitulating the activity of Drosophila Ft. Knowledge about the exact downstream signalling pathways activated by each family member remains in its infancy, but it is becoming clearer that each may have tissue specific and redundant roles in development. Importantly there is also evidence building to suggest that Fat cadherins may be lost or gained in certain cancers. This thesis represents the first in-depth biochemical investigation of human FAT1 cadherin, particularly its comparative expression in normal versus cancer cells. The first chapter studied the expression profile of all FAT cadherins in a panel of 20 cultured melanoma cells where all melanoma cell lines variably, but universally express FAT1 at the mRNA level and less commonly Fat2, Fat3 and Fat4. Both normal melanocytes and keratinocytes also express comparable FAT1 mRNA levels relative to melanoma cells. Analysis of the protein processing of FAT1 in keratinocytes revealed that human FAT1 was site-1 (S1) cleaved into a non-covalent heterodimer before achieving cell surface expression. A similar processing event had been reported in Drosophila Ft indicating that this was an evolutionary conserved mechanism. The use of inhibitors also established such cleavage is catalysed by a member of the proprotein convertase family, likely furin. However, in melanoma cells the non-cleaved pro-form of FAT1 was also expressed on the cell surface together with the S1-cleaved heterodimer. The appearance of both processed and non-processed forms of FAT1 on the cell surface demarked two possible biosynthetic pathways. Moreover FAT1 processing in melanoma cells generated a potentially functional proteolytic product in melanoma cells: a persistent 65kDa membrane-bound cytoplasmic fragment no longer in association with the extracellular fragment. Localisation studies of FAT1 both in vitro and in vivo showed melanoma cells display high levels of cytosolic FAT1 protein whereas keratinocytes, despite comparable FAT1 expression levels, exhibited mainly cell-cell junctional staining. The mechanisms deriving the unprocessed FAT1 and the p65 product were then further investigated to uncover the potential biological activities of these cancer specific products. The second chapter investigated the mechanisms behind dual processing of FAT1 in cancer cells including the mechanism of FAT1 heterodimerisation. Generally the S1 processing step and accompanying receptor heterodimerisation is thought to occur constitutively but the functional significance of this process in transmembrane receptors has been unclear and controversial. Using siRNA against a number of different proprotein convertases it was established that the S1-cleavage of FAT1 is catalysed only by furin. Mass spectrographic analysis identified the precise location of the cleavage site occurring between the laminin G and the second EGF domain on the extracellular domain of FAT1, consistent with an evolutionarily conserved region found in Drosophila DE-cadherin known to be involved in heterodimerisation. Utilising furin overexpressing studies in melanoma together with the furin deficient LoVo cells, indicated the likely reason behind partial heterodimerisation of FAT1 was deficiency in furin activity. Moreover, it was also determined from these experiments that only the heterodimer form of FAT1 was subject to a second cleavage step (S2) and subsequent release of the extracellular domain. This indicated that S1-processing was a prerequisite for FAT1 ectodomain shedding and established a general biological precedent with implications for the shedding of other transmembrane receptors that undergo heterodimerisation. Part of this work also established an ELISA assay against the extracellular domain of FAT1 that may find utility to investigate shed FAT1 as a potential new cancer biomarker in blood. Previous studies in Drosophila had shown that the interaction between Ft and its ligand, the large cadherin Dachsous (Ds) is regulated through ectodomain phosphorylation mediated by the atypical kinase, Four-jointed (Fj). The third chapter investigated the process of ectodomain phosphorylation of FAT1 on the basis that this important regulatory mechanism may be conserved. Using the known Fj-phosphorylation motif, in silico analyses were undertaken to determine if phosphorylation sites were conserved in human FAT cadherins. This search identified nine potential sites in FAT1 as potential substrates for the sole homologue of Fj in humans, FJX1. Using general antibodies against phospho-serine and phospho-threonine it was revealed that the extracellular domain of FAT1 was multiply phosphorylated on these residues. However, silencing FJX1 using either siRNA or stable shRNA transduction did not indicate any role for FJX1 in FAT1 ectodomain phosphorylation. Nevertheless, given that many regulatory processes are conserved between Drosophila and vertebrate Fat cadherins, the establishment that ectodomain phosphorylation occurs in FAT1 provides the strong likelihood that this process will be important in regulating the interaction of FAT1 with its presently unknown ligand. This knowledge may therefore provide an essential starting point for identifying the ligand of FAT1 and in helping to understand how their interaction is regulated between cells.
27
Rinas, Aimee Lynn. "Advancing the Applicability of Fast Photochemical Oxidation of Proteins to Complex Systems." Thesis, 2016. http://hdl.handle.net/1805/10991.
Full textAbstract:
Indiana University-Purdue University Indianapolis (IUPUI)Hydroxyl radical protein footprinting coupled with mass spectrometry has become an invaluable technique for protein structural characterization. In this method, hydroxyl radicals react with solvent exposed amino acid side chains producing stable, covalently attached labels. Although this technique yields beneficial information, the extensive list of known oxidation products produced increases the complexity of identifying and quantifying oxidation products. The current methods available for quantifying the extent of oxidation either involve manual analysis steps, or limit the number of searchable modifications or the size of sequence database. This creates a bottleneck which can result in a long and arduous analysis process, which is further compounded in a complex sample. In addition to the data complexity, the peptides containing the oxidation products of hydroxyl radical-mediated protein footprinting experiments are typically much less abundant than their unoxidized counterparts. This is inherent to the design of the experiment as excessive oxidation may lead to undesired conformational changes or unfolding of the protein, skewing the results. Thus, as the complexity of the systems studied using this method expands, the detection and identification of these oxidized species can be increasingly difficult with the limitations of data-dependent acquisition (DDA) and one-dimensional chromatography. The recently published in cell FPOP method exemplifies where this field is headed - larger and more complex systems. This dissertation describes two new methodologies and one new technology for hydroxyl radical-mediated protein footprinting, expanding the applicability of the method. First is development of a new footprinting analysis method for both peptide and residue level analysis, allowing for faster quantification of results. This method utilizes a customized multilevel search workflow developed for an on-market search platform in conjunction with a quantitation platform developed using a free Excel add-in, expediting the analysis process. Second is the application of multidimensional protein identification technology (MudPIT) in combination with hydroxyl radical footprinting as a method to increase the identification of quantifiable peptides in these experiments. Last is the design and implementation of a flow system for in cell FPOP, which hydrodynamically focuses the cells, and when used yielded a 13-fold increase in oxidized proteins and 2 orders of magnitude increase in the dynamic range of the method.
28
Jesus, Diana Sofia Santiago. "Tailoring of the cellular microenvironment to guide cell fate and functions for bone tissue engineering strategies." Master's thesis, 2021. http://hdl.handle.net/10773/33110.
Full textAbstract:
The ability of stem cells to differentiate into almost every cell type has been
harnessed in tissue engineering strategies to direct their fate into specific
lineages, through the mimicking of the extracellular matrix and
microenvironment of tissues. For long, regenerative medicine approaches were
almost exclusively dependent on the delivery of biochemical cues, but currently
the role of mechanobiology in cellular behaviour has been increasingly clarified.
Surface topography is one of the most well studied physical signal used for
guiding cell fate. Different patterns have been shown to mediate several cellular
events, including proliferation, migration, and differentiation. However, most
research has been conducted in a two-dimensional context (2D), which does
not truly mimic the native environment, while tri-dimensional (3D) constructs
remain fairly unexplored. Furthermore, while synthetic polymers present
tailoring advantages, they may hinder cell functions, including adhesiveness to
substrates.
In this work, we propose an integrative 3D approach, combining biochemical
and physical stimulation, by a set of surface modifications applied to
polycaprolactone microparticles (PCL). We evaluate their performance in
mediating cellular behaviour, including cell adhesion and differentiation into the
osteogenic lineage. Specifically, polycaprolactone microspheres were modified
into discoidal microparticles presenting a nanogrooved surface pattern by
imprinting, as confirmed by scanning electron microscopy, followed by coatings
with poly(ethyl acrylate) (PEA), fibronectin (FN) and bone morphogenic protein-
2 (BMP-2). This technology allows more efficient delivery of biochemical
signals, enabling the use of smaller concentrations, making it safer and less
expensive than current approaches, allied to the topography effect.
Furthermore, different growth factors may be bound instead of BMP-2, enabling
the application of the modified microparticles to other target-tissues responsive
to topography.
Modified particles were seeded with human adipose-derived stem cells
(hASCs) in static and dynamic conditions and used for a bottom-up assembly,
in a 3D concept. Results showed that the modified microparticles can support
cell viability and adhesion up to 21 days. In addition, the presence of
osteogenic markers and important bone components suggest that, for
themselves, topography and the biochemical coatings can promote
differentiation of hASCs in the osteogenic lineage. Nonetheless, the overlap of
the patterning dimensions and thickness of the PEA/FN/BMP-2 coating
hampers the synergistic effect that we first expected. Finally, we trace future
directions for the exploration of more biomimetic topographies.The ability of stem cells to differentiate into almost every cell type has been harnessed in tissue engineering strategies to direct their fate into specific lineages, through the mimicking of the extracellular matrix and microenvironment of tissues. For long, regenerative medicine approaches were almost exclusively dependent on the delivery of biochemical cues, but currently the role of mechanobiology in cellular behaviour has been increasingly clarified. Surface topography is one of the most well studied physical signal used for guiding cell fate. Different patterns have been shown to mediate several cellular events, including proliferation, migration, and differentiation. However, most research has been conducted in a two-dimensional context (2D), which does not truly mimic the native environment, while tri-dimensional (3D) constructs remain fairly unexplored. Furthermore, while synthetic polymers present tailoring advantages, they may hinder cell functions, including adhesiveness to substrates. In this work, we propose an integrative 3D approach, combining biochemical and physical stimulation, by a set of surface modifications applied to polycaprolactone microparticles (PCL). We evaluate their performance in mediating cellular behaviour, including cell adhesion and differentiation into the osteogenic lineage. Specifically, polycaprolactone microspheres were modified into discoidal microparticles presenting a nanogrooved surface pattern by imprinting, as confirmed by scanning electron microscopy, followed by coatings with poly(ethyl acrylate) (PEA), fibronectin (FN) and bone morphogenic protein- 2 (BMP-2). This technology allows more efficient delivery of biochemical signals, enabling the use of smaller concentrations, making it safer and less expensive than current approaches, allied to the topography effect. Furthermore, different growth factors may be bound instead of BMP-2, enabling the application of the modified microparticles to other target-tissues responsive to topography. Modified particles were seeded with human adipose-derived stem cells (hASCs) in static and dynamic conditions and used for a bottom-up assembly, in a 3D concept. Results showed that the modified microparticles can support cell viability and adhesion up to 21 days. In addition, the presence of osteogenic markers and important bone components suggest that, for themselves, topography and the biochemical coatings can promote differentiation of hASCs in the osteogenic lineage. Nonetheless, the overlap of the patterning dimensions and thickness of the PEA/FN/BMP-2 coating hampers the synergistic effect that we first expected. Finally, we trace future directions for the exploration of more biomimetic topographies.
Mestrado em Biotecnologia
29
Baril, Philip. "Étude théorique des mécanismes de transfert d'énergie suivant le passage d'un ion rapide sans un matériau." Thèse, 2008. http://hdl.handle.net/1866/8024.
Full text
30
Machut, McLean. "Corrosion behavior of steels for lead-alloy cooled fast reactors and the effects of surface modifications on corrosion performance." 2007. http://catalog.hathitrust.org/api/volumes/oclc/152593766.html.
Full textAbstract:
Thesis (M.S.)--University of Wisconsin--Madison, 2007Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 53-54).
31
Huang, Chen-Hsiu, and 黃振修. "Oocyte-induced extracellular matrix modification affected soma sexual fate from male to female phase in the protandrous black porgy, Acanthopagrus schlegelii." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/73113991881112992565.
Full textAbstract:
碩士國立臺灣海洋大學
水產養殖學系
104
Protandrous black porgy has a digonic gonad. After the E2 treatment, ectopic oocyte could be observed in the newly generated testis. Ectopic oocyte-expressing Figla levels highly-correlated to the Sertoli cells transdifferentiate into follicle-like cells. The ectopic oocytes were competent to create an ovarian microenvironment to protect against a testicular environment. The Amh released by ectopic oocyte-bordering Sertoli cells may suppress the proliferative activities of spermatogonia. Therefore, proliferation-arrested spermatogonia may act as a physical boundary to prevent the factors released by an ectopic oocyte-created female microenvironment to interfere with further ovarian development. The modification of heparan sulfate may keep specific factors in the extracellular matrix, we surmise that heparan sulfate help Amh gather in the nearby ectopic oocyte. In the present study, we collected abnormal testicular tissue contain ectopic oocyte from the ovotestis generating by feeding fish with E2 and then withdraw, as well as normal ovary tissue contain normal oocyte. The expression of glycosyl normal oocytes had no difference during 6-10 month of age, but had difference in the ectopic oocyte compared with normal oocytes by PAS staining. According to transcriptomic analysis of oocytes we found 4 genes in the heparan sulfate family. Base on qPCR results, the hs6st genes highly expressed in the ovary as compared with the testis. However, the hs6st genes are not related to sex differentiation. The gdf9 and the bmp15, belong to TGF-β superfamily members, are expressed in an oocyte-specific manner from a very early stage and play key roles in folliculogenesis. Furthermore, we select grb2 which has highly correlation with figla expression by transcriptomic analysis, and further confirmed by qPCR. The ectopic oocytes expressed stronger signals of bmp15, gdf9 and grb2 than the normal oocytes by in situ hybridization. Take together, our results support the hypothesis that the ectopic oocytes can create an ovarian microenvironment to protect against a testicular environment.
32
Wu, Ming-Feng, and 吳明鋒. "Modification and Implementation of an Edge-Based Fast Intra Prediction Mode Decision Algorithm for H.264/AVC High Resolution Real-time Systems." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/72087099617532834749.
Full textAbstract:
碩士國立交通大學
電機學院通訊與網路科技產業專班
96
In this thesis, we propose architecture of H.264/AVC fast intra prediction mode decision in high resolution real-time applications. Because the intra prediction mode decision occupied lots computations of the H.264/AVC video coding, besides it needs the extra time for modes generating of the intra prediction mode decision (about 20%), and the processed data is high dependence also, hence, it is a bottleneck of the high resolution real-time applications. In the intra prediction mode decision operations, we use an algorithm which based on the edge information of the object. It can reduce about 66% estimations of mode predictions with negligible loss of video quality and a little increasing of data rate. According to this algorithm, we propose a low cost architecture and the gate counts can be reduced about 50% to compare with the former design. The total gate counts are 86,671 only and the maximum operating frequency is 250 MHz. It is a favorable contribution to all the current high resolution real-time video processing while without spending a lot of hardware.
33
Sheibani, Ali. "The Effect of Salt Reduction, Culture and Process Modifications on the Physicochemical and Microbiological Characteristics of Cheddar-type Cheeses." Thesis, 2016. https://vuir.vu.edu.au/32884/.
Full textAbstract:
The World Health Organization has identified hypertension as one of the leading causes of death in the world, and consumers are subsequently seeking ways to decrease their daily salt dietary intake. This trend is increasing demand for low-salt foods. This thesis contributes to the literature on low-salt cheese production by investigating how salt reduction affects cheese quality. Salt is one of the key ingredients used in cheese manufacturing to perform several functions, including antimicrobial functions, moisture control, formation of texture and structure, management of pH and acidity, and flavour enhancement. Thus, the objective of this study was to produce cheese using a low amount of salt and investigate the effects of salt reduction on the cheese’s microbiological, textural, sensory and physicochemical properties, and salt release.
34
Gupta, Rahul. "Influence of Chemical Coating on Droplet Impact Dynamics." Thesis, 2016. http://hdl.handle.net/2005/3262.
Full textAbstract:
Dynamic behavior of impacting water drops on superhydrophobic solid surfaces provides important details on the stability/durability of such solid surfaces. Multi-scale surface roughness combined with a layer of low energy chemical is an essential surface modification process followed to create superhydrophobic capabilities on solid surfaces. The present work aims at studying the effect of low energy surface coating on droplet impact dynamics by carrying out experiments of water drop impacts on rough solid surfaces with and without chemical modification. A group of six aluminium alloy (Al6061) surfaces (three pairs) are prepared. Roughness, characterized in terms mean surface roughness, Ra, is introduced to these metallic surfaces using sand-paper polishing, electric discharge machining (EDM), and chemical based surface etching process. Low energy surface layer is laid on the rough surfaces by coating NeverWet hydrophobic solution, octadecyl-trichloro-silane (OTS), and perfluorodecyltricholorosilane (FAS-17). The impact dynamics of water drops is analyzed by capturing high speed videos for a range of drop Weber number from 1 to 570 and the salient features of drop impact process on the coated rough surfaces are compared with the corresponding uncoated rough surfaces. A one-to-one comparison on the spreading, fingering, receding, and final equilibrium of impacting drops on the coated and uncoated target surfaces is presented.
Upon coating NeverWet, the original surface features of the base aluminium surface are completely covered by the hydrophobic coating material resulting in a fresh top surface layer. The outcomes as well as the bounce-off characteristics of impacting water drops on the coated surface are comparable to those observed on lotus leaf. The surface morphology features of rough aluminium surfaces coated with OTS and FAS-17 are comparable to those of the corresponding uncoated surfaces. The quantitative measurements on primary spreading and maximum spread factor of impacting drops are largely unaffected by the presence of low energy chemical coating. The dominant effect of surface coating is seen on the receding of impacting drops and hence the final drop configuration. This behavior is more prominently seen on EDM fabricated rough surface (larger Ra) combined with OTS coating than that on etching based rough surface (smaller Ra) combined with FAS-17 coating highlighting the dependence of coating effect with roughness features.