Academic literature on the topic 'Supports activateurs'
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Journal articles on the topic "Supports activateurs"
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Czuba, Beata. "Social support for veterans." Scientific Journal of the Military University of Land Forces 199, no. 1 (March 18, 2021): 5–20. http://dx.doi.org/10.5604/01.3001.0014.8106.
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The article aims to outline how mission-traumatized veterans perceive social support. Social support is an essential resource for an individual in coping with the difficulties in everyday life. The subject of the examination is quantitative research with veterans’ participation and own qualitative research – free interviews analyzed using the IPA (Individual Phenomenological Analysis) method. The obtained results indicate that social support can be considered in terms of a meta-resource that activates other vital resources of humans, thereby strengthening them in difficult situations. The expected support criteria are met by friendly self-help groups that can operate in military units and complement the help provided by professionals.
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Solmonson, Ashley, Brandon Faubert, Wen Gu, Aparna Rao, Mitzy A. Cowdin, Ivan Menendez-Montes, Sherwin Kelekar, et al. "Compartmentalized metabolism supports midgestation mammalian development." Nature 604, no. 7905 (April 6, 2022): 349–53. http://dx.doi.org/10.1038/s41586-022-04557-9.
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AbstractMammalian embryogenesis requires rapid growth and proper metabolic regulation1. Midgestation features increasing oxygen and nutrient availability concomitant with fetal organ development2,3. Understanding how metabolism supports development requires approaches to observe metabolism directly in model organisms in utero. Here we used isotope tracing and metabolomics to identify evolving metabolic programmes in the placenta and embryo during midgestation in mice. These tissues differ metabolically throughout midgestation, but we pinpointed gestational days (GD) 10.5–11.5 as a transition period for both placenta and embryo. Isotope tracing revealed differences in carbohydrate metabolism between the tissues and rapid glucose-dependent purine synthesis, especially in the embryo. Glucose’s contribution to the tricarboxylic acid (TCA) cycle rises throughout midgestation in the embryo but not in the placenta. By GD12.5, compartmentalized metabolic programmes are apparent within the embryo, including different nutrient contributions to the TCA cycle in different organs. To contextualize developmental anomalies associated with Mendelian metabolic defects, we analysed mice deficient in LIPT1, the enzyme that activates 2-ketoacid dehydrogenases related to the TCA cycle4,5. LIPT1 deficiency suppresses TCA cycle metabolism during the GD10.5–GD11.5 transition, perturbs brain, heart and erythrocyte development and leads to embryonic demise by GD11.5. These data document individualized metabolic programmes in developing organs in utero.
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Myers, Elizabeth A., and Linda Rinaman. "Trimethylthiazoline supports conditioned flavor avoidance and activates viscerosensory, hypothalamic, and limbic circuits in rats." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 288, no. 6 (June 2005): R1716—R1726. http://dx.doi.org/10.1152/ajpregu.00479.2004.
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Interoceptive stimuli modulate stress responses and emotional state, in part, via ascending viscerosensory inputs to the hypothalamus and limbic forebrain. It is unclear whether similar viscerosensory pathways are recruited by emotionally salient exteroceptive stimuli, such as odors. To address this question, we investigated conditioned avoidance and central c-Fos activation patterns in rats exposed to synthetic trimethylthiazoline (TMT), an odiferous natural component of fox feces. Experiment 1 demonstrated that rats avoid consuming novel flavors that previously were paired with TMT exposure, evidence that TMT supports conditioned flavor avoidance. Experiment 2 examined central neural systems activated by TMT. Odor-naive rats were acutely exposed to low or high levels of TMT or a novel nonaversive control odor and were perfused with fixative 60–90 min later. A subset of rats received retrograde neural tracer injections into the central nucleus of the amygdala (CeA) 7–10 days before odor exposure and perfusion. Brain sections were processed for dual-immunocytochemical detection of c-Fos and other markers to identify noradrenergic (NA) neurons, corticotropin-releasing hormone (CRH) neurons, and retrogradely labeled neurons projecting to the CeA. Significantly greater proportions of medullary and pontine NA neurons, hypothalamic CRH neurons, and CeA-projecting neurons were activated in rats exposed to TMT compared with activation in rats exposed to the nonaversive control odor. Thus the ability of TMT to support conditioned avoidance behavior is correlated with significant odor-induced recruitment of hypothalamic CRH neurons and brain stem viscerosensory inputs to the CeA.
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Pollak, Shaul, Shira Omer-Bendori, Eran Even-Tov, Valeria Lipsman, Tasneem Bareia, Ishay Ben-Zion, and Avigdor Eldar. "Facultative cheating supports the coexistence of diverse quorum-sensing alleles." Proceedings of the National Academy of Sciences 113, no. 8 (January 19, 2016): 2152–57. http://dx.doi.org/10.1073/pnas.1520615113.
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Bacterial quorum sensing enables bacteria to cooperate in a density-dependent manner via the group-wide secretion and detection of specific autoinducer molecules. Many bacterial species show high intraspecific diversity of autoinducer–receptor alleles, called pherotypes. The autoinducer produced by one pherotype activates its coencoded receptor, but not the receptor of another pherotype. It is unclear what selection forces drive the maintenance of pherotype diversity. Here, we use the ComQXPA system of Bacillus subtilis as a model system, to show that pherotype diversity can be maintained by facultative cheating—a minority pherotype exploits the majority, but resumes cooperation when its frequency increases. We find that the maintenance of multiple pherotypes by facultative cheating can persist under kin-selection conditions that select against “obligate cheaters” quorum-sensing response null mutants. Our results therefore support a role for facultative cheating and kin selection in the evolution of quorum-sensing diversity.
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Fraser, Lynn R. "Strontium supports capacitation and the acrosome reaction in mouse sperm and rapidly activates mouse eggs." Gamete Research 18, no. 4 (December 1987): 363–74. http://dx.doi.org/10.1002/mrd.1120180410.
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Grisan, Francesca, Martina Spacci, Carlotta Paoli, Andrea Costamagna, Marco Fantuz, Miriam Martini, Konstantinos Lefkimmiatis, and Alessandro Carrer. "Cholesterol Activates Cyclic AMP Signaling in Metaplastic Acinar Cells." Metabolites 11, no. 3 (February 26, 2021): 141. http://dx.doi.org/10.3390/metabo11030141.
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Cholesterol is a non-essential metabolite that exerts both structural and signaling functions. However, cholesterol biosynthesis is elevated, and actively supports, pancreatic carcinogenesis. Our previous work showed that statins block the reprogramming of mutant KRAS-expressing acinar cells, that spontaneously undergo a metaplastic event termed acinar-to-ductal metaplasia (ADM) to initiate carcinogenesis. Here we tested the impact of cholesterol supplementation on isolated primary wild-type acinar cells and observed enhanced ductal transdifferentiation, associated with generation of the second messenger cyclic adenosine monophosphate (cAMP) and the induction of downstream protein kinase A (PKA). Inhibition of PKA suppresses cholesterol-induced ADM ex vivo. Live imaging using fluorescent biosensors dissected the temporal and spatial dynamics of PKA activation upon cholesterol addition and showed uneven activation both in the cytosol and on the outer mitochondrial membrane of primary pancreatic acinar cells. The ability of cholesterol to activate cAMP signaling is lost in tumor cells. Qualitative examination of multiple normal and transformed cell lines supports the notion that the cAMP/PKA axis plays different roles during multi-step pancreatic carcinogenesis. Collectively, our findings describe the impact of cholesterol availability on the cyclic AMP/PKA axis and plasticity of pancreatic acinar cells.
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Wu, Sheng-Shiung, Sing-Jie Jong, Kai Hu, and Jiann-Ming Wu. "Learning Neural Representations and Local Embedding for Nonlinear Dimensionality Reduction Mapping." Mathematics 9, no. 9 (April 30, 2021): 1017. http://dx.doi.org/10.3390/math9091017.
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This work explores neural approximation for nonlinear dimensionality reduction mapping based on internal representations of graph-organized regular data supports. Given training observations are assumed as a sample from a high-dimensional space with an embedding low-dimensional manifold. An approximating function consisting of adaptable built-in parameters is optimized subject to given training observations by the proposed learning process, and verified for transformation of novel testing observations to images in the low-dimensional output space. Optimized internal representations sketch graph-organized supports of distributed data clusters and their representative images in the output space. On the basis, the approximating function is able to operate for testing without reserving original massive training observations. The neural approximating model contains multiple modules. Each activates a non-zero output for mapping in response to an input inside its correspondent local support. Graph-organized data supports have lateral interconnections for representing neighboring relations, inferring the minimal path between centroids of any two data supports, and proposing distance constraints for mapping all centroids to images in the output space. Following the distance-preserving principle, this work proposes Levenberg-Marquardt learning for optimizing images of centroids in the output space subject to given distance constraints, and further develops local embedding constraints for mapping during execution phase. Numerical simulations show the proposed neural approximation effective and reliable for nonlinear dimensionality reduction mapping.
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Kolańczyk, Alina. "When Affect Supports Cognitive Control – A Working Memory Perspective." Polish Psychological Bulletin 47, no. 1 (April 1, 2016): 29–42. http://dx.doi.org/10.1515/ppb-2016-0004.
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Abstract The paper delineates a study of executive functions (EFs), construed as procedural working memory (WM), from a motivational perspective. Since WM theories and motivation theories are both concerned with purposive activity, the role of implicit evaluations (affects) observed in goal pursuit can be anticipated to arise also in the context of cognitive control, e.g., during the performance of the Stroop task. The role of positive and negative affect in goal pursuit consists in controlling attention resources according to the goal and situational requirements. Positive affect serves to maintain goals and means in the scope of attention (EF1), whereas negative affect activates the inhibition of non-functional contents, e.g., distractors and irrelevant objects (resulting in attention disengagement; EF2). Adaptation to conflict proceeds via sequential triggering of negative and positive affect (EF3). Moreover, it was demonstrated that the focus on action or reflection changes the scope of contents subjected to implicit (affective) control. Therefore, I suggest that the motivational system, to a large extent, plays the role of the Central Executive. The paper opens a discussion and proposes studies on affective mechanisms of cognitive control.
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Rafei, Moutih, Alexandre Rouette, Sylvie Brochu, Juan Ruiz Vanegas, and Claude Perreault. "Differential effects of γc cytokines on postselection differentiation of CD8 thymocytes." Blood 121, no. 1 (January 3, 2013): 107–17. http://dx.doi.org/10.1182/blood-2012-05-433508.
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Abstract The primary consequence of positive selection is to render thymocytes responsive to cytokines and chemokines expressed in the thymic medulla. In the present study, our main objective was to discover which cytokines could support the differentiation of positively selected thymocytes. To this end, we have developed an in vitro model suitable for high-throughput analyses of positive selection and CD8 T-cell differentiation. The model involves coculture of TCRhiCD5intCD69− double-positive (DP) thymocytes with peptide-pulsed OP9 cells and γc-cytokines. We report that IL-4, IL-7, and IL-21 have nonredundant effects on positively selected DP thymocytes. IL-7 signaling phosphorylates STAT5 and ERK; induces Foxo1, Klf2, and S1pr1; and supports the differentiation of classic CD8 T cells. IL-4 activates STAT6 and ERK and supports the differentiation of CD8intPD-L1hiCD44hiEOMES+ innate CD8 T cells. IL-21 is produced by thymic epithelial cells and the IL-21 receptor-α is strongly induced on DP thymocytes undergoing positive selection. IL-21 signaling phosphorylates STAT3 and STAT5, but not ERK, and does not support CD8 T-cell differentiation. However, IL-21 has a unique ability to up-regulate BCL-6, expand DP thymocytes undergoing positive selection, and increase the production of mature T cells. Our data suggest that injection of recombinant IL-21 might enhance thymic output in subjects with age- or disease-related thymic atrophy.
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Shih, Han-Yu, William Olcott, and Michael Krangel. "Chromatin conformations and contacts that support Tcra/d locus rearrangement (62.2)." Journal of Immunology 186, no. 1_Supplement (April 1, 2011): 62.2. http://dx.doi.org/10.4049/jimmunol.186.supp.62.2.
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Abstract The Tcra/d locus rearranges in DN thymocytes to assemble Tcrd genes and in DP thymocytes to assemble Tcra genes. We used 3D-FISH to show that the 3’ portion of the locus is contracted in both DN and DP thymocytes, whereas the 5’ portion is contracted in DN but decontracts in DP thymocytes. We proposed that the fully contracted conformation in DN thymocytes allows dispersed Vαs to be used in a single round of Vδ-Dδ-Jδ rearrangement, whereas the 3’-contracted, 5’-decontracted conformation in DP thymocytes allows for multiple rounds of Vα-to-Jα rearrangement initiating with 3' Vαs. For high resolution analysis, we used the 3C method to detect molecular interactions between different sites in the locus. The Tcra enhancer (Eα) activates the T early α promoter (TEA) to target 5’Jαs for initial rearrangement. Eα also activates proximal Vαs over 500 kb. We detected molecular interactions between Eα and TEA, between Eα and proximal Vαs, and between different proximal Vαs, in DP but not DN thymocytes. All pairwise interactions depended on Eα. With TEA deleted, Eα also interacted with downstream Jαs. We propose that Eα nucleates a chromatin hub that supports transcription and ordered Vα-to-Jα recombination. However, deletion of Eα does not impact Tcra/d locus 3’end contraction as measured by 3D-FISH. Thus, overall locus conformation is independent of Eα, but this conformation may facilitate Eα interactions with distant sites.
Dissertations / Theses on the topic "Supports activateurs"
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Sauter, Dominique. "Développement de nouveaux supports activateurs solides pour la polymérisation des oléfines." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1249.
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Pannier, Gaëlle. "Développement de nouveaux supports activateurs de catalyseurs à site unique pour la polymérisation des oléfines." Lyon 1, 2008. http://www.theses.fr/2008LYO10196.
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Depuis une dizaine d’années, la recherche sur l’hétérogénéisation des complexes métallocènes effectuée au Laboratoire de Chimie et Procédés de Polymérisation a beaucoup évolué. La chimie utilisée est complexe et basée sur des modifications de surface de supports inorganiques permettant d’obtenir des sites activateurs des métallocènes en polymérisation des oléfines. Cette recherche a permis le développement du nouveau concept de support activateur. L’obtention d’activateurs solides des complexes organométalliques très efficace pour la polymérisation des oléfines, a été réalisée sans ajout d’un activateur homogène (MAO, borate, …). Cependant, le principal inconvénient de ces nouveaux supports est la présence d’un très faible nombre de sites activateurs. La problématique de ce travail de thèse était de tenter de mieux comprendre comment fonctionnent ces supports activateurs, et donc de trouver comment il est possible de contrôler leur préparation en vue de les améliorer. Les deux caractéristiques principales des supports activateurs sont la nécessité d’une étape de fluoration lors de leur préparation, et la présence de groupements hydroxyles impliqués dans le processus d’activation. Lors de cette étude, nous avons développé à la fois de nouvelles voies de fluoration et de préparation d’hydroxyles de surface. Les supports les plus efficaces ont permis l’obtention de bonnes activités, du même ordre que celles obtenues en solution avec du MAO, ainsi que des polymères possédant une morphologie de grain particulaireSince around ten years, the research on the metallocenes complexes heterogeneisation realized in the “Laboratoire de Chimie et Catalyse de Polymerisation” (LCPP) evolved a lot. The used chemistry is complex and based on inorganic supports surface modifications allowing to obtain activating sites of métallocènes for olefins polymerization. This research allowed the development of the new concept of activating support. The obtaining of solid activators for organometallic complexes, very effective for the olefins polymerization, was realized without addition of a homogeneous activator (MAO, borate). However, the main drawback of these new supports is the presence of a very limited number of activating sites. The purpose of this PhD work was to try to better understand how these activating supports work, and thus to find how it is possible to control their preparation to improve them. Both main characteristics of the activating supports are the necessity of a fluorination stage during their preparation, and the presence of hydroxyls groups involved in the process of metallocene activation. During this study, we developed at once new ways of fluorination and preparation of surface hydroxyls. The most effective supports allowed the obtaining of good catalytic activities, the same order as those obtained in solution with the MAO, as well as the polymers possessing particle morphology
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Bisiriyu, Muhammad Taoheed. "Préparation et Caractérisation de Nouveaux Catalyseurs Supportés à base de Rhénium pour la Metathèse des Oléfiness." Electronic Thesis or Diss., Lyon 1, 2023. https://n2t.net/ark:/47881/m6sb45v3.
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Les catalyseurs hétérogènes à base de rhénium occupent une place unique dans la métathèse des oléfines, réaction largement utilisée dans de nombreux procédés industriels, en raison de leur capacité à catalyser cet échange de fragments oléfiniques à température ambiante. Parmi les catalyseurs décrits dans la littérature, les matériaux, obtenus par activation du méthyl-rhenium-trioxo (MTO) sur des supports munis de sites acides de Lewis, tels que l'alumine, la silice-alumine et l'alumine modifiée par ZnCl2, présentent de hautes activités initiales en métathèse des oléfines. Cependant, ces systèmes catalytiques montrent certaines limites, tels qu'une faible proportion en sites actifs et une désactivation rapide. L'objectif de la thèse est de développer une nouvelle méthode de synthèse de catalyseurs supportés qui implique un échange de ligands entre des supports activateurs et le précurseur MTO. La stratégie générale consiste à concevoir des supports activateurs portant des ligands alkyles et/ou chlorure, qui, après un transfert vers le rhénium suivi d'une α-H abstraction, permet en plus de l'augmentation de la proportion en sites actifs "Re-carbène", une activité importante en métathèse des oléfines. Ainsi, la première partie de ce travail s'est focalisée sur le développement de supports activateurs à base d'aluminium. Les supports activateurs ciblés, comprennent des fragments Al-CH2tBu ou Al-Cl, formés par le greffage par voie chimie organométallique de surface de [Al(CH2tBu)3] ou [Al(CH2tBu)2Cl]2 sur une silice ou une alumine déshydroxylées à 200-700°C. La structure des matériaux obtenus, déterminée par bilan de masse, spectroscopies DRIFT et RMN du solide, dépend de la température de déshydroxylation du support, du choix du précurseur et du solvant. Ainsi, [Al(CH2tBu)3] réagit avec la silice (SiO2-700) dans l'éther pour donner sélectivement [≡SiO-Al(CH2tBu)(Et2O)], espèce mono-podale, alors qu'avec le pentane, l'espèce majoritaire obtenue est bipodale, [(≡SiO)2Al(CH2tBu)], avec le transfert d'un ligand neopentyl vers le silicium par ouverture d'un pont siloxane. La seconde étape consiste en une activation du MTO sur ces supports activateurs. Ainsi, l'activation du MTO sur le matériau présentant des espèces [(≡SiO)2Al(CH2tBu)] donne après transfert du ligand neopentyle une espèce penta-coordonnée de structure [(≡SiO)2AlO-Re(=O)2(Me)CH2tBu)], caractérisée par bilan de masse, spectroscopies DRIFT, RMN du solide et EXAFS. Après traitement à 70 °C, cette espèce mène par α-H abstraction à un fragment rhénium-carbène supporté. Ce nouveau système catalytique présente des performances en métathèse du propylène supérieures au catalyseur classique MTO/γ-Al2O3. La meilleure activité est principalement attribuée à une plus grande proportion en sites actifs, due à cette nouvelle stratégie d'activation du MTO par échange de ligands. Ceci constitue le premier exemple de catalyseur à base de MTO supporté sur silice actif en métathèse des oléfinesRepositioned heterogeneous catalysts based on rhenium hold a unique position in olefin metathesis, a widely used reaction in various industrial processes, due to their ability to catalyze the exchange of olefinic fragments at room temperature. Among the catalysts described in the literature, materials obtained by activating methylrhenium trioxo (MTO) on supports containing Lewis acids, such as alumina, silica-alumina, and zinc chloride-modified alumina, have shown high initial activities in olefin metathesis. However, these catalytic systems have certain limitations, such as a low proportion of active sites and rapid deactivation. The aim of this thesis was to develop a new method for synthesizing supported catalysts that involves ligand exchange between activating supports and the MTO precursor. The general strategy is to design activating supports bearing alkyl and/or chloride ligands that, upon transfer to rhenium followed by α-H abstraction, not only increase the fraction of active "carbene" sites but also exhibit significant activity in olefin metathesis. Thus, the first part of this work focused on the development of aluminum-based activating supports. The targeted activating supports, comprising Al-CH2tBu or Al-Cl fragments, are formed by surface organometallic chemistry grafting of [Al(CH2tBu)3] or [Al(CH2tBu)2Cl]2 onto dehydroxylated silica or alumina at 700°C or 200°C. The structure of the resulting materials, determined by mass balance analysis, DRIFT spectroscopy, and solid-state NMR, depends on the support dehydroxylation temperature, as well as the choice of precursor and solvent. For example, [Al(CH2tBu)3] reacts with silica (SiO2-700) to selectively yield monopodal species in ether, [≡SiO-Al(CH2tBu)(Et2O)], while in pentane, the major species obtained is bipodal, [(≡SiO)2Al(CH2tBu)], with the transfer of a neopentyl ligand to silicon through siloxane bridge opening. The second step involves the activation of MTO on these activating supports. For instance, the activation of MTO on [(≡SiO)2Al(CH2tBu)] results in the transfer of a neopentyl ligand, forming a penta-coordinated species with the structure [(≡SiO)2AlO-Re(=O)2(Me)CH2tBu)]. This species is characterized by mass balance analysis, DRIFT spectroscopy, solid-state NMR and EXAFS. Upon heating to 70°C, this species undergoes a α-H abstraction to yield a supported catalyst with a rhenium-carbene fragment. This new catalytic system exhibits better catalytic performances for propylene metathesis, compared to the classical MTO/γ-Al2O3 catalyst. The better activity is primarily attributed to a higher proportion of active sites achieved through this new MTO activation strategy involving a ligand exchange. This is the first example of MTO supported on a functionalized silica that is an active catalyst for olefin metathesis
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Tudella, Joana. "Nouvelles approches pour la résolution de problèmes récurrents en polymérisation des oléfines." Bordeaux 1, 2008. http://www.theses.fr/2008BOR13791.
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Les polyoléfines sont, parmi les polymères synthétiques celles qui trouvent de très nombreuses applications dans notre vie quotidienne et leur part de marché est toujours en croissance. La découverte de nouveaux catalyseurs métallocènes ou à base d'autres dérivés de métaux de transition a permis un gain en productivité mais également l'accès à de nouveaux polymères ayant des microstructures originales. Malgré ces développements des problèmes pratiques limitent encore leur utilisation et application au niveau industriel. Pendant ce travail, nous avons examiné de nouvelles approches pouvant permettre de lever certaines de ces limitations. Trois aspects ont été étudiés en particulier : la fonctionnalisation des chaînes de polyoléfines ; le développement de nouvelles voies pour la synthèse du méthylaluminoxane (MAO) et autres activateurs du même type ; le contrôle de la morphologie des polyethylènes par l'utilisation de nouveaux supports organiques à base de polystyrène.
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Zouhri, Yassir. "Amélioration du procédé de synthèse de polychlorure de vinyle par décomposition catalytique de peroxydes." Electronic Thesis or Diss., Université de Lille (2022-....), 2022. http://www.theses.fr/2022ULILR017.
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L'accélération de la polymérisation en suspension du monomère chlorure de vinyle (VCM) par amorçage de peroxyde à l’aide d’un système redox a été étudié ainsi que son impact sur les propriétés du polychlorure de vinyle (PVC) qui en résulte. Ce projet s'inscrit dans le cadre d'une collaboration CIFRE entre la société Vynova-Mazingarbe et l'équipe MOCAH du Laboratoire UCCS de l'université de Lille. L'amorçage de la polymérisation est basé sur la formation de radicaux par décomposition redox d'un pré-amorceur peroxyde, induite par un activateur à deux composants, appelé "kicker". Cet activateur consiste en un dérivé organométallique en quantité catalytique, le catalyseur, qui réduit le peroxyde et provoque sa décomposition, combiné à un agent réducteur capable de régénérer la forme oxydée du catalyseur. Une étape de développement préliminaire a été réalisée sur le 1-chlorobutane en tant que modèle du monomère VCM, afin de fournir une première évaluation de l'effet de l’amorçage redox avec le kicker avant sa mise en œuvre en polymérisation du VCM en suspension. Une série de catalyseurs à base de fer, de type ferrocène (Fc) et ses dérivés ont été évalués, combinés à une série d'agents réducteurs hydrosolubles, pour la décomposition des pré-amorceurs di-(2-éthylhexylperoxydicarbonate) (EHP) ou peroxyde de lauroyle (LPO). Lorsqu’ils ont été utilisés pour la polymérisation en suspension du VCM, une amélioration significative de la vitesse a été obtenue en utilisant le système kicker Fc/Rongalite ou decamethylferrocene/Rongalite en présence des peroxydes EHP ou LPO. L'utilisation d’un agent de transfert de phase visant à améliorer le contact entre les constituants du kicker situés dans différentes phases du milieu réactionnel a également été examinée; l'agent de transfert de phase bromure de cétyltriméthylammonium utilisé dans cette étude s’est avéré capable d’améliorer les performances du kicker Fc/Rongalite dans certaines conditions optimisées. D'autres agents réducteurs, dont certains nouveaux, appartenant à la famille des sulfinates et potentiellement plus solubles en phase organique ont également été synthétisés, en utilisant la Rongalite comme produit de départ. Au sein de cette famille, tous les dérivés et en particulier le N-perfluoroéthane α-aminométhanesulfinate de dicyclohexylammonium, ont montré en combinaison avec le ferrocène une bonne efficacité pour accélérer la vitesse de polymérisation tout en préservant la stabilité du milieu réactionnel et les propriétés du polymère finalThe acceleration of radical suspension polymerization of vinyl chloride monomer (VCM) by peroxide initiation using a redox system has been investigated as well as its impact on the properties of the resulting polyvinyl chloride (PVC). This project is part of a CIFRE collaboration between the company Vynova-Mazingarbe and the MOCAH team of the UCCS Laboratory of the University of Lille. The initiation of the polymerization was based on the formation of radicals via redox decomposition of a peroxide pre-initiator, promoted by a dual-component activator, so-called “kicker”. This kicker consists of an organometallic derivative in catalytic amount, the catalyst, that reduces the peroxide and causes its decomposition combined with a reducing agent, which is able to regenerate the oxidized form of the catalyst. A preliminary development stage was carried out on a model monomer of VCM, 1-chlorobutane, to provide a first evaluation of the effect of redox initiation with the kicker before being applied in the suspension polymerization of VCM. A series of iron-based catalysts, mainly ferrocene (Fc) and its derivatives, combined with a range of water-soluble reducing agents, have been evaluated toward the decomposition of di-(2-ethylhexylperoxydicarbonate) (EHP) or lauroyl peroxide (LPO) as pre-initiators. When applied to the suspension polymerization of VCM, a significant improvement in rate has been achieved using Fc/Rongalite or decamethylferrocene/Rongalite as kicker in the presence of EHP or LPO. The use of a phase transfer agent to improve the interaction between the kicker compounds located in different phases has also been examined; the cetyltrimethylammonium bromide phase transfer agent used in this study has been shown to further improve the performance of the Fc/Rongalite kicker under certain optimized conditions. Other reducing agents, including some new ones, belonging to the family of sulfinates and potentially more soluble in the organic phase have been synthesized, using Rongalite as a starting product. Within this family, all compounds, in particular dicyclohexylammonium N-perfluoroethane α-aminomethanesulfinate, have shown a good efficiency in accelerating the rate of polymerization when combined with Fc in the presence of EHP peroxide, while preserving the stability of the reaction medium as well as the properties of the resulting polymer
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Tsai, Chi-Chang, and 蔡琦璋. "Musashi1 activates STAT3 signaling pathway and supports cell survival of glioblastoma cells." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/70590446089759879560.
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碩士國立陽明大學
解剖學及細胞生物學研究所
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The RNA-binding protein Musashi-1 contains two RNA recognition motifs (RRMs), and acts an important role in maintaining the self-renew of mammalian neural stem/progenitor cells. By overexpressed Musashi-1 in GBM cell lines we have established, we found that Musashi-1 may promote drug resistance and against drug-induced apoptosis. Previous studies have shown that Musashi-1 regulates mRNA expression level through binding to 3'UTR and represses its translation. However, there is little known about Musashi-1 also interacts with the proteins. In this study, we identify Stat3 as a Musashi-1 binding protein, and find that Musashi-1 enhances Stat3 phosphorylation on serine 727 under stress stimulation. We also demonstrate that Musashi-1 regulates p-Stat3 (serine727) translocating to the nuclear under stress stimulation by extracting nuclear and cytoplasmic fraction. Taken together, our data suggest that Musashi-1 can activate Stat3 signaling, which not only promote Stat3 phosphorylation, but also influence its function. Therefore, Musashi-1 and Stat3 are potential targets for GBM prevention and treatment.
Book chapters on the topic "Supports activateurs"
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Nakashige, Mutsuhiro, Ryota Shibusawa, and Katsutoshi Oe. "Vocal Behavior Acquisition with a Toy Operating by Sound Detection." In Assistive Technology: Shaping a Sustainable and Inclusive World. IOS Press, 2023. http://dx.doi.org/10.3233/shti230656.
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We investigated a speech training support system targeting students in special needs education classes who are engaged in training to acquire a binary relationship where their vocalizations elicit reactions from others. Previously, there was a challenge in maintaining interest and achieving learning effectiveness when teachers intervened to encourage vocalizations using teaching aids such as picture books. To address this, we designed and integrated an electronic circuit with a movable toy that captures the interest of the supported students. The circuit includes a switch that turns on and activates a secondary circuit only when vocalizations are detected. In this paper, we report on the training using the developed speech support system and validate its functionality.
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Schwartzman, Roy. "Trumping Reason." In Advances in Linguistics and Communication Studies, 269–95. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-7439-3.ch015.
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Why does support for Donald Trump remain resilient despite the preponderance of arguments and evidence that should refute so many of his claims? The answer lies in how Trump's rhetoric fully embraces intuitively based rationales for allegiance. This chapter analyzes Donald Trump's rhetoric throughout his campaign and presidency through the lens of moral foundations theory, which identifies clusters of value commitments that correlate with political allegiance. Trump activates connections with foundational values of his constituents through specific heuristic devices, especially loss aversion, availability, and representativeness. Synthesizing behavioral economics with the dramatistic rhetorical theories of Kenneth Burke reveals how Trump's claims resist counterargument and what rhetorical resources offer potential avenues for alternative positions to gain traction.
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Das, Rupa, and Saikat Biswas. "Influence of Abiotic Stresses on Seed Production and Quality." In Seed Biology Updates [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.106045.
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Climate change is exerting detrimental impacts on agriculture through various biotic and abiotic stresses. Abiotic stresses such as drought, flood, temperature extremes, salinity, chemicals, heavy metals, nutrient scarcity/toxicity, wind and light in combination more adversely affect the seed production and quality by hampering plant’s morphological, physiological, cellular, biochemical and molecular activities than alone, resulting in poor production of high-quality seeds. Deterioration of yield and quality arises also under abiotic stresses. Under abiotic stresses, plant activates its own defensive mechanisms by escaping, avoiding and tolerating stresses. Some of the plant’s defensive mechanisms include plant’s morphological, cellular, physiological, biochemical and molecular changes to adapt the stresses, synthesis of compounds such as ABA, proline, polyamines increasing the activities of ROS quenchers, expression of stress-resisting genes and activation of enzymes. Further, exogenous application of phytohormones, stress-alleviating compounds, modification of agronomic management, modern breeding strategies such as development of resistant varieties can also help to cope up with stresses and produce quality seeds. Financial and policy support of government or NGOs regarding development of infrastructure, research technologies and thereby, multi-locational trials as well as technology transfusion through extension activities are needed to curtail down the devastating impact of abiotic stresses on quality seed production.
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Sayeduzzaman, Md, and Ashik Mahmud. "Design and Implementation of a Multi-Source Automatic Transfer Switch (ATS) System to Run the Utility Systems Via Different Power Sources and 3-Phase Synchronous Industrial Generator." In Advances in Transdisciplinary Engineering. IOS Press, 2022. http://dx.doi.org/10.3233/atde221199.
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An automatic transfer switch (ATS) is a device that automatically shifts a power source from its primary source to a backup source when the primary source fails or breaks down. When a primary power system fails, the ATS activates a standby power source, such as an uninterruptible power supply. An ATS can also start longer-term backup power systems, such as Industrial diesel or gas-powered generators, to keep power sources running until utility power comes back. Because of the poor power supply in developing countries, alternative power generation with automation is required to support utility supply. Automation has grown in popularity and now plays a vital role in the electronic industry. Electromechanical relays, magnetic contactors, and delay timers are the main components of designing an ATS, which has three input power and one output power source. To avoid loss of life or data, both of which are very expensive in business operations, delicate processes, and activities in hospitals, the pharmaceutical industry, and many other essential businesses require continuous power support. Therefore, a system that can operate autonomously with little or no human involvement is designed and implemented for a three-phase synchronous industrial generator that will power the utility systems. This project’s most exciting feature is its ability to automatically activate the secondary power source once the primary one fails due to a power breakout because it has multiple source inputs and a single output. When both sources fail because of a breakout, it turns on the industrial Generator and turns it off when either the primary or secondary power source is again restored.
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Bamshad, Michael J., and Lynn B. Jorde. "TBX3 and TBX5 and the Ulnar–Mammary and Holt–Oram Syndromes." In Inborn Errors Of Development, 867–77. Oxford University PressNew York, NY, 2008. http://dx.doi.org/10.1093/oso/9780195306910.003.0094.
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Abstract Ulnar–mammary syndrome (UMS) and Holt–Oram syndrome (HOS) are rare, autosomal dominant, multiple malformation disorders. UMS is characterized by apocrine abnormalities including breast defects and malformations of the posterior elements of the upper limb. In contrast, HOS is typi)ed by heart malformations, most commonly an atrial septal defect (ASD) or ventricular septal defect (VSD), conduction abnormalities, and defects of the anterior elements of the upper limb. UMS and HOS are caused by myriad mutations in TBX3 and TBX5, respectively, two members of the T-box gene family linked together on chromosome 12q24. There is little evidence to support a genotype–phenotype correlation for either condition. The long-term care of patients with UMS or HOS can be challenging, but in general, most patients do well. In the heart, TBX5 physically activates atrial natriuretic factor (ANF), connexin-40 (cx40), and GATA4 to play an important role in formation of the septa, chambers, and conduction system. In the limb, Tbx5 appears to activate )broblast growth factor-10 (Fgf10) directly to initiate forelimb bud outgrowth and to in%uence, in part, forelimb identity. Tbx3 acts as a negative repressor of p19ARF and p53 and interferes with apoptosis. Tbx3 is essential for formation of the mammary glands and plays multiple roles in limb development including the speci)cation of digit identity. In vitro studies demonstrate that substitutions in the DNA-binding domain of TBX3 and TBX5 or truncations in the C terminus of the TBX3 and TBX5 proteins fail to bind DNA and lose their transcriptional properties. Loss of Tbx3 repressor activity may promote a pro-apoptotic path that results in a diminished number of mesodermal cells in the developing limb and breast. Loss of Tbx5 activity appears to result in the down-regulation of several genes critical for normal heart development.
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Poletto, Cecilia, and Jean-Yves Pollock. "Remnant movement and smuggling in some romance interrogative clauses." In Smuggling in Syntax, 255–317. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780197509869.003.0010.
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This chapter analyzes the syntax of interrogative clauses in French and in some Northern Italian dialects (NIDs), including so-called “wh-in-situ” configurations. It shows that their intricate properties can be derived from standard computations (“wh-movement” and remnant movement of vP/IP to a Top/ground slot) to either the vP Left periphery (“LLP”) or the CP domain (“HLP”). If so, it becomes necessary to raise the question of why some languages make use of the LLP or the HLP, or indeed both, like French, as argued in sections 2–7. In significant cases the morphological properties of the various Wh-words and the surface forms of the sentences provide all the clues required by the language learner and the linguist. In French, movement of interrogative pronouns to the HLP is actually movement to a free relative layer. This is an automatic consequence of the fact that, as in Germanic, most French and Romance wh-items are morphologically both (free) relative and interrogative pronouns. This will explain the distribution of French Quoi (what)—only an interrogative pronoun—and similar items in a number of NIDs (Che in Bellunese and Illasi, Què in Borgomanerese and Monese). In the same vein, sections 9–11 show that the fact that French Que is both an interrogative and relative element, in addition to being a clitic qua interrogative, will account for its properties in conjunction with a “smuggling” analysis of Subject Clitic Inversion (SCLI). Sections 14–16 show that many NIDs make use of both the LLP and the HLP and that smuggling is involved in deriving the form and interpretation of interrogative clauses in Bellunese, Illasi, and Monese. In addition to renewed empirical arguments in favor of remnant movement and smuggling, sections 2–7 argue that embedded interrogative infinitives in (at least) French are vPs and only have a (sometimes truncated) LLP. In addition to the fruitfulness of the “smuggling” idea for Romance, the main theoretical result of this chapter is that the interrogative syntax of the languages and dialects studied here supports the idea that “relative constructions” or “interrogative constructions” are not primitives of the language faculty, since in significant cases the derivation of questions activates both the interrogative side of the LLP and the (free) relative side of the HLP.
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Vasylyshyna, N. M., and N. V. Honcharenko-Zakrevska. "SECTION #2. INNOVATIVE METHODS AND TECHNOLOGIES IN THE STUDY AND TEACHING OF FOREIGN 2.1 THE EFFICIENCY OF NEW TEACHING METHODOLOGIES IN THE PROCESS OF SHAPING FOREIGN COMMUNICATIVE COMPETENCIES." In CURRENT THEORY AND PRACTICE ASPECTS OF LINGUISTICS, SOCIOLINGUISTICS AND METHODOLOGY OF FOREIGN LANGUAGES AT UNIVERSITIES IN MODERN GLOBAL HIGHER EDUCATIONAL SPACE. RS Global Sp. z O.O., 2022. http://dx.doi.org/10.31435/rsglobal/052-4.
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Learning a foreign language as if it were a mother tongue would be the ideal way, since the need to learn grammar and structures would be obviated. This is difficult if the teachers themselves are non-native and is therefore one of the most complicated aspects. Things have changed over the years, and though it was one of the most effective ways of teaching, it no longer considered the same now. This is due to various reasons, maybe because: the present generation gets exposure to the world through social media; their knowledge base is augmenting by the information available on the internet; the students nowadays are more impatient and to grab their attention, teaching methods need to cater to their dynamic thinking process. Language teaching, like any other topic, has undergone a lot of changes. It has shifted to roleplays, interactive games, short visuals from the traditional ways, such as lectures by facilitators with only a blackboard to support and spell repetition and grammar worksheets, have shifted to role-plays. Thus, we consider it very important to investigate how to teach English in each situation. Sometimes it is not a matter of teaching English but a matter of teaching in English. The main purpose is to create a new method made of all the different methods already known and take advantage of all the positive features in each method. However, just a simple mixture of all methods would not be enough since we are dealing with very different situations regarding age, level and resources. Therefore, the main idea is to use all the methods in a varying proportion depending on the circumstances. Learning a foreign language may cause stress and anxiety and in order to mitigate this problem, teachers could follow a Natural approach involving teaching in a setting as close as possible to the one people learn their mother tongue. The actuality of our research can be proven with the fact that digitization has no doubt changed our education system, but we cannot say that it has diminished the value of our old time classroom learning. The best part about the digitization of foreign languages education in the 21st century is that it is combined with the aspects of both classroom learning and online learning methods. Walking hand in hand both act as a support system to each other, which gives a stronghold to our modern students. To add, digitization in foreign languages education has also proved to be the right method for saving resources. Online examination platforms have restricted the frivolous usage of paper. During research we have noticed that there is no consensus in academia on the effectiveness and the appropriateness of the use of gaming activities in teaching or learning English. However, we consider it expedient and relevant use of them is able to increase motivation to study English language. We have identified the following benefits of using on line resources during studu English: increases interest and motivates to perform tasks; immerses in English environment; stimulates the ability to work independently; promotes development critical thinking, memory, attention; forms foreign language competence in auditioning and socio-cultural competence; activates the desire to communicate in English when discussing the revised; provides an opportunity to form realistic and modern situations for discussion; allows use a wide range of exercises and various forms of work at the stages of previewing and postviewing; higher education learners learn to understand nonverbal communication and enrich your active and passive conversational vocabularies language. The research concluded that all on line measures developed to improve foreign language training of the foreign languages discipline are developed by teachers of the department of foreign languages and teaching methods of foreign languages, graduation proposals are to taken into account by language departments. We hope that the results will develop further steps in optimization of foreign language training in blended learning and distance education.
Conference papers on the topic "Supports activateurs"
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"DIGITAL SUPPORT ACTIVATES YOUNG ELDERLY TO HEALTH-ENHANCING PHYSICAL ACTIVITY." In 15th International Conference on ICT, Society and Human Beings (ICT 2022), the 19th International Conference Web Based Communities and Social Media (WBCSM 2022) and 14th International Conference on e-Health (EH 2022). IADIS Press, 2022. http://dx.doi.org/10.33965/ict_wbc_eh2022_202204l023.
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Qu, Dongfeng, Nathaniel Weygant, Randal May, William Berry, James Tomasek, Parthasarathy Chandrakesan, Michael Schlosser, and Courtney Houchen. "Abstract 1731: Overexpression of DCLK1 in pancreatic cancer activates KRAS/PI3K/MTOR pathway signaling and supports tumorigenesis, invasiveness, and stemness." In Proceedings: AACR 107th Annual Meeting 2016; April 16-20, 2016; New Orleans, LA. American Association for Cancer Research, 2016. http://dx.doi.org/10.1158/1538-7445.am2016-1731.
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Ding, Houzhu, and Robert C. Chang. "Bioprinting of Liquid Hydrogel Precursors in a Support Bath by Analyzing Two Key Features: Cell Distribution and Shape Fidelity." In ASME 2018 13th International Manufacturing Science and Engineering Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/msec2018-6675.
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Microextrusion-based bioprinting within a support bath material is an emerging additive manufacturing technique for fabricating complex three-dimensional (3D) tissue constructs. However, there exists fundamental knowledge gaps in understanding the spatiotemporal mapping of cells within the bioprinted constructs and their shape fidelity when embedded in a support bath material. To address these questions, this paper advances quantitative analyses to systematically determine the spatial distribution for cell-laden filament-based tissue constructs as a function of the bio-ink properties. Also, optimal bio-ink formulations are investigated to fabricate complex 3D structures with superior shape integrity. Specifically, for a 1D filament printed in a support bath, cells suspended in low viscosity liquid hydrogel precursors are found to exhibit a characteristic non-uniform distribution as measured by a degree of separation (Ds) metric. In a 2D square wave pattern print, cells are observed to flow and aggregate downstream at certain positions along the in-plane print direction. In a 3D analysis, owing to the high cell density and gravity effects, a non-uniform cell distribution within a printed cylindrical structure is observed in the build direction. From the structural standpoint, the addition of CaCl2 to the support bath activates the hydrogel cross-linking process during printing, resulting in 3D prints with enhanced structural outcomes. This multidimensional print analysis provides evidence that, under the emerging bioprinting support bath paradigm, the printable parameter space can be extended to low viscosity liquid hydrogel precursor materials that can be systematically characterized and optimized for key process performance outcomes in cell distribution and shape fidelity.
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Ofosu, F. A., G. J. Modi, M. R. Buchanan, J. Hirsh, and M. A. Blajchman. "HEPARIN IS NOT AN EFFICIENT INHIBITOR OF THE FACTOR Xa-DEPENDENT ACTIVATION OF FACTOR V AND FACTOR VIII." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1642931.
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We have previously proposed that the steps in coagulation most sensitive to inhibition by heparin are the thrombin-dependent activation of factor V and factor VIII. This observation was based on the demonstration that therapeutic concentrations of heparin or 1μM of the thrombin specific inhibitor, phe-pro-arg CH2Cl (PPACK) completely inhibited the activation of prothrombin when contact-activated plasma (CAP) was recalcified for up to 1 min. Under similar conditions, heparin and PPACK only partially inhibited the activation of factor X. Moreover, the addition of thrombin (lOnM) to CAP 1 min before that of heparin or PPACK reversed their inhibitory effects. We now provide further support for our hypothesis by showing that when the activity of thrombin is suppressed by heparin or PPACK, efficient activation of radiolabelled prothrombin occurs only when the factor Xa then present activates factor V and factor VIII. We compared the effects of HEP of PPACK on the following four systems for initiating the activation of prothrombin: (1) CAP; (2) CAP + lOnM thrombin; (3) CAP + InM Xa and (4) unactivated plasma + InM Xa + InM Va + coagulant phospholipids. In each system, the enzymes were added 1 min before the heparin or PPACK. In the absence of heparin or PPACK, all four systems generated the same amount of thrombin activity in 45s. Complete inhibition of prothrombin activation by heparin and PPACK was observed only in system 1 which did not contain exogenous thrombin or factor Xa. No inhibition by heparin or PPACK was observed when thrombin or factor Xa was added to CAP in systems (2) and (3). Only partial inhibition was observed in system (4) which contained exogenous prothrombi-nase complex. Factor Xa thus provides an effective by-pass mechanism for the activation of factor VIII and factor V in plasma containing therapeutic concentrations of heparin. Our data provide further evidence that the heparin-antithrombin III system is not effective in inactivating factor Xa. These results support the hypothesis that in unactivated normal plasma, the primary anticoagulant effect of heparin is the inhibition of the thrombin-dependent activation of factor V and factor VIII.
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Vigneri, Valentino, Christoph Odenbreit, and Matthias Braun. "Numerical evaluation of the plastic hinges developed in headed stud shear connectors in composite beams with profiled steel sheeting." In 12th international conference on ‘Advances in Steel-Concrete Composite Structures’ - ASCCS 2018. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/asccs2018.2018.7166.
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For composite beams using novel steel sheeting, the current Eurocode 4 rules sometimes overestimate the load bearing capacity of the shear connector. This is due to the larger rib heights and the smaller rib widths in comparison with the old studies, which have been carried out to calibrate the current design equations. The RFCS Project “DISCCO” investigated this phenomena and the working group under mandate M515, CEN/TC250/SC4/SC4.T3 is enhancing this equation and working on a proposal to be taken over in the new version of Eurocode 4.The proposed new equation covers the failure behaviour of the shear connection more in detail. The test results show, that the failure consists in a combined concrete cone and stud in bending. Due to the geometry of novel steel sheeting, the load bearing capacity of the headed stud shear connector is no more limited by its shear capacity, but by its bending capacity.A 3D non-linear finite element model is developed and validated through the support of the DISCCO push-out tests. A good agreement between numerical and experimental results in terms of force-slip behaviour is achieved. Special attention of this work lies on the numerical evaluation of the number of plastic hinges ny: a stress-based procedure is presented and the results are compared to the equations presented for new Eurocode 4.The numerical simulations show that the upper plastic hinge moves up as the slip increases due to the progressive crushing of the concrete in the rib. From the parametric study, it turns out that ny is linearly proportional to the embedment depth. Compared to pre-punched hole decking, through-deck welding specimen activates less plastic hinges in the studs because of the higher stiffness provided at the base of the stud.
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Tans, G., J. Rosing, M. Berrettini, B. Lammle, and J. H. Griffin. "AUTOACTIVATION OF HUMAN PLASMA PREKALLIKREIN." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1642898.
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Incubation of purified human plasma prekallikrein with sulfatides or dextran sulfate resulted in spontaneous activation of prekallikrein as judged by the appearance of amidolytic activity towards the chromogenic substrate H-D-pro-phe-arg-p-nitroanilide (S 2302). The time course of generation of amidolytic activity was sigmoidal with an apparent lag phase followed by a rapid activation until finally a plateau was reached. Soybean trypsin inhibitor completely blocked prekallikrein activation whereas corn, limabean and ovomucoid trypsin inhibitor did not. The Ki of the reversible inhibitor, benzamidine, for autoactivation (240 uM) was identical to the Ki of benzamidine for kallikrein. Thus, spontaneous prekallikrein activation and kallikrein showed the same specificity for a number of serine protease inhibitors, indicating that prekallikrein is activated by its own enzymatically active form, kallikrein. Immunoblotting analysis showed that, concomitant with the appearance of amidolytic activity, prekallikrein was cleaved. However, prekallikrein was not quantitatively converted into two-chain kallikrein since other polypeptide products were visible on the gels. This accounts for the observation that in amidolytic assays not all prekallikrein present in the reaction mixture was measured as active kallikrein. Kinetic analysis showed that prekallikrein activation can be described by a second-order reaction mechanism in which prekallikrein is activated kallikrein. The apparent second order rate constant was 27000 M-ls-1 (pH 7.2, 50 uM sulfatides, ionic strength 1=0.06, at 37°C). Autocatalytic prekallikrein activation was strongly dependent on the ionic strength, since there was a considerable decrease in the rate of the reaction at high salt concentrations. Our data support a prekallikrein autoactivation mechanism in which surface-bound kallikrein activates surface-bound prekallikrein. The rate constant of autoactivation is considerably lower than the rate constants reported for Factor Xlla dependent prekallikrein formation. Autocatalytic prekallikrein activation may, however, contribute to kallikrein formation during the initiating phase of contact activation.
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Morrison, Matthew C., and Kenneth J. Bateman. "Transfer and Storage of Molten Salt for the Pyroprocessing of Used Nuclear Fuel." In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-36481.
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The transfer and storage of molten salts are being examined to support electrorefining operations at the Idaho National Laboratory. Two important factors that will need to be considered when removing molten salt from either of the two electrorefiners are (1) how to remove salt in a safe and timely manner and (2) how to store significant amounts of electrorefiner salt. A Vacuum Induced Salt Transfer and Storage (VISTAS) system is being evaluated to address these two important factors. This process draws a vacuum in a container through the use of a venturi vacuum pump. The end of a heated drawtube is inserted into the molten salt bath and the molten salt is pulled into the container. A redundant level switch triggered both by the thermal conductivity of the salt and a preset temperature threshold then activates a solenoid, which turns off the argon supply to the venturi vacuum pump, stopping the flow of molten salt. A cooling coil is incorporated into the salt transfer equipment design as a failsafe if the level switch was to fail. A full-scale version of the conceptual design (43 kg capacity) was fabricated to test the vacuum draw salt withdrawal method in an inert argon atmosphere glovebox. In addition, a custom molten salt furnace was designed and fabricated within the glovebox to represent the actual size of an electrorefiner port. Initial testing of the VISTAS system was very successful. The salt was transferred at a consistent rate and the level switch reliably stopped flow. Because the system has a failsafe cooling mechanism, it is considered to have low risk of a salt spill. The container was found to improve storage density, reduce the diffusion of moisture, and reduce material surface area when compared to current options. This system appears to be well suited for this application and further development is recommended.
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Hariman, H., J. R. Hughes, P. J. Grant, and J. A. Davies. "THE EFFECTS OF PHYSIOLOGICAL CONCENTRATIONS OF VASOPRESSIN ON COMPONENTS OF THE FIBRINOLYTIC PATHWAY." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643121.
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Evidence from studies in man suggests that vasopressin (aVP) at physiological concentrations activates the coagulation pathway, increases plasminogen activator activity and may have a role in the regulation of haemostasis under conditions of physical stress. Infusion of aVP in normal subjects increases plasma factor VIII concentrations and shortens the euglobulin clot lysis time (ECLT), but the mechanisms involved in these changes and their haemostatic significance are unclear. The aims of this study were to investigate the effects of aVP on the fibrinolytic pathway and to evaluate whether thrombin or plasmin are generated in vivo by aVP. After 30 min 0.9% saline infusion, vasopressin (20iu in 250ml 0.9% saline) was infused at 2.0 u/h for 1h in 9 normal subjects to achieve plasma aVP concentrations comparable to those attained during stress. Venous blood samples were taken before saline infusion (time 0) and every 30 min for 2h for assay of aVP, activated partial thromboplastin time (APTT), fibrinopeptide A (FPA), FPA generation time, FPBB15-42 ECLT, tissue-type plasminogen activator (t-PA) and t-PA inhibition. Plasma aVP rose frcm 0.5 pg/ml at time 0 to (median) 70.7 pg/ml at 90 min. The APTT shortened from 43.8 ± 1.9 to 34.4 ± 1.6 (SEM) seconds (p < 0.001) at 90 min. Plasma FPA and the FPA generation time remained unchanged (p > 0.05). Plasminogen activator activity rose from 36.4 ± 15.2 to 587.5 ± 206.6 units (p < 0.005), t-PA increased frcm 229.8 ± 20.4 to 1107.4 ± 224.1 ml.U/ml (p < 0.005) and t-PA inhibition fell frcm 7.9 ± 1.1 to 3.9 ± 0.9 I.U/ml (p < 0.05) in response to the aVP infusion. FPB815-42 increased frcm a baseline value of 1.7 ± 0.4 to 2.2 ± 0.7 pmol/ml after 90 min (p < 0.05). The results suggest the effects of aVP on fibrinolysis are due to an increase in t-PA and decrease in t-PA inhibition. The increase in FPBB 15-42 with no change in FPA supports the hypothesis that plasmin was generated by non-fibrin dependent pathways.
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Morrissey, J. H., S. A. Gregory, and T. S. Edgington. "DIFFERENTIAL EXPRESSION AND SUBCELLULAR LOCALIZATION OF TISSUE FACTORIN A CONSTITUTIVE VERSUS AN INDUCIBLE CELL TYPE." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643739.
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Tissue factor (TF) is an integral membraneglycoprotein and receptor present on a variety of cells outside of the vasculature, but normally absent from intravascular cells. TF plays a central role in initiation of coagulation by rapidly binding and allosterically activating bound factor Vll/VIIa, which proteoly-tically activates coagulation factors IX and X. This protease cascade appears to play a role in the cellular inflammatory response, during which endothelial cells and monocytes/macrophages can be induced to express cell surface TF.Monocyte TF can be induced in response to endotoxin and also via direct interaction with activated T cells and by a specific lymphokine.We have developed a panel of polyclonaland twenty-nine high affinity monoclonal antibodies to human TF. The antibodies recognize TF epitopes under a broad range of conditions, some of which rapidly and efficiently neutralize <95% of TF activity isolated from brain, placenta and expressed bycultured cells. Using these antibodies in immunohistochemical assays, we haveobserved little or no TF antigen cytologically associated with resting monocytes, noTF activity, and following stimulation, the cytologic appearance of TF antigen parallels the acquisition of TF activity.Immunohistochemical staining of stimulated monocytesis diffuse, consistent with homogeneous cell-surface distribution of the TF molecule.In addition, the normal human fibroblastic cell lines GM1380 and GM1381, whichexpress TF const itutively, show a cytologically different and much more intense pattern of intracellular inclusions of TF. This is consistent with previous observationsthat lysed cells show about five-fold moreTF activity than do intact cells. These findings indicate the presence of an intracellular storage site for TF in some cell types, a pattern presently associated only with constitutive expression of this receptor protein. In addition, they confirm thatTF is induced in stimulated monocytes rather than translocation or modification. Supported by NIH grants HL-16411 and CA-41085.
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Rampart, M., H. Bult, A. G. Herman, P. J. Jose, and T. J. Williams. "PROSTACYCLIN (PGI2) FORMATION IN RELATION TO ANAPHYLATOXIN C5a GENERATION DURING RABBIT ENDOTOXIN SHOCK." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1642837.
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Injection of endotoxin (LPS) in animals, a model for gram-negative septic shock, leads to intravascular activation of the complement system, and is one of the few conditions in which 6-oxo-PGF]CX and thromboxane (TX) B2 (non-enzymic metabolites of PGI2 and TXA2) can be detected in arterial blood. Previously we reported associations between complement activation, PGI2 biosynthesis and LPS-induced hypotension in rabbits. As C5a and C5adesArg trigger endothelial PGI2 formation in vitro, we have now measured the plasma levels of immunoreactive (ir) C5a in relation to generation of PGI2 and changes in arterial blood pressure in LPS shock. Pentobarbitone anaesthethized rabbits received LPS (E. coli 0111:B4, 0.5 mg/kg) or saline via the marginal ear vein. A catheter in the left carotid artery was used to collect blood and to monitor mean arterial blood pressure (MABP). Platelet and leukocyte numbers, haemolytic complement titre (CH50), and plasma ir6-oxo-PGFioc , irTXB2 and irC5a were measured 15 min before and at different times after saline or LPS injection. LPS caused a dose- and time-dependent formation of irC5a in rabbit serum in vitro, predominantly via the classical pathway. LPS also activated complement in vivo, as indicated by about 20 % reduction of CH50 titre (measured after 3h) and a marked increase of arterial irC5a (20-120 ng/ml) in the first 2 to 5 min. After 30 min, irC5a had returned to baseline levels (< 2-5 ng/ml) and remained so up to 3h after injection of LPS. This irC5a peak correlated with a shortlasting initiation of PGI2 release (from < 20 pg/ml up to 550 pg/ml) and a drop in MABP (from about 95 mmHg to 50 mmHg) 2-5 min after LPS. None of these changes occurred after saline injection.In conclusion, LPS activates complement in vivo with concomitant formation of C5a. This peptide may trigger -either directly or after phagocyte activation - endothelial PGI2 biosynthesis, leading to arterial hypotension. This is supported by the suppression of the initial rise of arterial ir6-oxo-PGF1α and hypotension in complement-depleted rabbits. Inhibition of C5a formation or activity may prove to be a meaningful approach to the treatment of septic circulatory shock.
Reports on the topic "Supports activateurs"
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Lytvynova, Svitlana H. Хмаро орієнтоване навчальне середовище загальноосвітнього навчального закладу. [б. в.], August 2018. http://dx.doi.org/10.31812/0564/2451.
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Research goals: to outline the state of secondary education to implement a cloud-oriented learning environment (COLE), establishing research objectives: to determine the readiness of students to the introduction of COLE, to develop a conceptual framework of cooperation in COLE at the level of the institution, identify the actors interact COLE. The object of research supports the learning environment secondary schools; subject – a cloud-oriented learning environment of secondary schools. Research methods used: analysis of statistics and publications. Experimental research and conducted in secondary schools Obolon district of Kyiv. Intermediate results: the architecture of COLE 44 secondary schools of the district, introduced more than 10 thousand accounts established electronic interaction between teachers and students by e-mail Outlook. Currently under development cloud storage (SkyDrive) training materials teachers practiced the skills of teamwork and planning tools calendars. The main conclusions and recommendations. Implementation of COLE at secondary schools provides endless opportunities both teacher and student, in fact created conditions for innovation and learning. Without a doubt we can say that for the future of Honshu, for full use must have a quality Internet, motivated teachers. For subjects of the educational process, the conditions of access to learning materials anywhere, anytime, and it activates the cognitive and creative activity of students that will improve key indicators of learning.
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Prusky, Dov, Noel T. Keen, and Stanley Freeman. Elicitation of Preformed Antifungal Compounds by Non-Pathogenic Fungus Mutants and their Use for the Prevention of Postharvest Decay in Avocado Fruits. United States Department of Agriculture, January 1996. http://dx.doi.org/10.32747/1996.7570573.bard.
Full textAbstract:
C. gloeosporioides attacks unripe avocado fruits in the orchard. Germinated spores produce appressoria that germinate and breach the cuticle, but the resultant subcuticular hyphae become quiescent and do not develop further until fruit is harvested and ripens. Resistance of unripe avocado to attach by C. gloeosporioides is correlated with the presence of fungitoxic concentrations of the preformed antifungal compound, 1-acetoxy-2-hydroxy-4-oxoheneicosa-12, 15 diene in the pericarp of unripe fruits. The objective of this proposal was to study the signal transduction process by which elicitors induce resistance in avocado. It was found that abiotic elicitors, infection of avocado fruit with C. gloeosporioides or treatment of avocado cell suspension with cell-wall elicitor induced a significant production of reactive oxygen species (ROS). Ripe and unripe fruit tissue differ with regard to the ROS production. The unripe, resistant fruit are physiologically able to react and to produce high levels of ROS and increased activity of H+ATPase that can enhance the phenylpropanoid pathway ad regulate the levels of the antifungal compound-diene, inhibit fungal development, resulting in its quiescence. Interestingly, it was also found that growth regulators like cytokinin could do activation of the mechanism of resistance. Postharvest treatments of cytokinins strongly activated the phenylpropanoid pathway and induce resistance. We have developed non-pathogenic strains of C. gloeosporioides by Random Enzyme Mediated Integration and selected a hygromycin resistance, non-pathogenic strain Cg-142 out of 3500 transformants. This non-pathogenic isolate activates H+ATPase and induces resistance against Colletotrichum attack. As a basis for studying the importance of PL in pathogenicity, we have carried out heterologous expression of pel from C. gloeosporioides in the non-pathogenic C. magna and determine the significant increase in pathogenicity of the non-pathogenic strain. Based on these results we can state that pectate lyase is an important pathogenicity factor of C. gloeosporioides and found that fungal pathogenicity is affected not by pel but by PL secretion. Our results suggest that PH regulates the secretion of pectate lyase, and support its importance as a pathogenicity factor during the attack of avocado fruit by C. gloeosporioides . This implicates that if these findings are of universal importance in fungi, control of disease development could be done by regulation of secretion of pathogenicity factors.