Tesis sobre el tema "Stabilité in vitro"
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Arien, Albertina. "Étude in vitro et in vivo de la stabilité de liposomes contenant de la calcitonine". Bordeaux 2, 1995. http://www.theses.fr/1995BOR28364.
Texto completoLeenhardt, Julien. "Synthèse et études de radiomarquage au 68Ga, 99mTc, 177Lu et 161Tb de nouveaux chélatants dérivés de l'oxine en vue d'application théranostique". Electronic Thesis or Diss., Université Grenoble Alpes, 2024. http://www.theses.fr/2024GRALS009.
Texto completoTheranostic applications in nuclear medicine would ideally allow cancer diagnosis and internal vectorised radiotherapy to be carried out using the same molecule, simply by substituting the radionuclide used. The theranostic agent is made up of a chelating part capable of strongly complexing the radionuclides and a ligand part that enables delivery to a tumour target. Today, one of the most promising pair of radionuclides is Gallium-68 or [68Ga]Ga3+ (diagnostic, β+ particle emitter) and Lutetium-177 or [177Lu]Lu3+ (therapeutic, β- particle emitter), but there is currently no chelating system that is as good for both radionuclides. The DOTA chelate currently used extensively in nuclear medicine, although it has slow radiolabelling kinetics that require heating of the reaction medium, contraindicating its use with heat-sensitive molecules. At the Department of Molecular Chemistry at Grenoble Alpes University, chemists have expertise in siderophores or bio-inspired models, which enable gallium to be complexed very efficiently, as well as other metal cations that could be of interest in nuclear medicine. My thesis work therefore began with radiolabelling studies of two of these abiotic siderophores with [68Ga]Ga3+ and [99mTc]Tc3+. The data obtained clearly demonstrated that these siderophores, O-TRENSOX and O-TRENOX, complexed effectively, at room temperature, these two radioisotopes used daily in nuclear medicine imaging. Preliminary radiolabelling studies obtained with Terbium-161 or [161Tb]Tb3+ (therapeutic, emitting β- particles and Auger electrons) also confirmed that these structures could complex 'larger' metal cations, thus opening the doors to theranostics. The second aspect dealt during this thesis was the development of a new N4O4 acyclic octadentate chelating system, allowing better complexation of radionuclides with higher coordination index requirements, such as lanthanides or actinides, under mild conditions. Using several different synthetic routes, we succeeded in synthesising, purifying and characterising this new ligand in order to initiate radiolabelling studies. These studies demonstrated excellent complexation with [68Ga]Ga3+, [177Lu]Lu3+ and [161Tb]Tb3+ at room temperature, enabling us to consider this new structure as effective for complexing various radiometals that can be used as theranostics.Taken together, these results indicate that these new chelating systems have favourable characteristics for the radiolabelling of many radiometals under mild conditions. These results open up new prospects for the development of new radiopharmaceuticals for theranostics in nuclear medicine
Courraud, Julie. "Etude du comportement des caroténoïdes et rétinoïdes en digestion in vitro : stabilité, bioaccessibilité et pouvoir antioxydant au niveau intestinal". Thesis, Montpellier 1, 2013. http://www.theses.fr/2013MON13513/document.
Texto completoAccording to the FAO, two billions of people suffer from the « hidden hunger » which corresponds to micronutrient deficiencies and includes the vitamin A deficiency, principal cause of blindness throughout the world. Besides, an excessive food consumption entails an oxidative stress for the organism which increases the risk to develop non communicable diseases such as diabetes and cardiovascular diseases. Present in numerous fruits and vegetables, some carotenoids are an indirect source of vitamin A and could also contribute to the health benefits of the consumption of fruits and vegetables via antioxidant properties. In this thesis, in vitro behaviour of carotenoids and retinoids during in vitro digestion (IVD) has been studied, from their release from dietary matrices to their interactions with intestinal cells. My research is structured around micellisation: key process of carotenoid and retinoid absorption. First, stability and bioaccessibility during IVD of these pure compounds have been compared with those of their homologues from carrot juice, raw and cooked spinach and fortified flour. Second, a new model of oxidation of intestinal bile salt (BS)-based nanoemulsions has been developed. Relations between mixed micelles structure, reactivity to oxidation and protection by antioxidants have been studied using fatty acid degradation monitoring. Finally, preliminary experiment were carried out on enzymatic reactivity of colon cells (Caco-2) to various oxidants and mixed micelles. During IVD, pure β-carotene and retinyl palmitate were particularly unstable conversely with lutein and retinyl acetate. Moreover, the dietary matrix protected these compounds and favoured their bioaccessibility especially when it was grounded or cooked. Indeed, pre-treatment have a significant impact on carotenoid release and should be considered as serious means to optimize intake. Developed intestinal nanoemulsions constituted of spherical or cylindrical micelles, the latter being less resistant to oxidation. Distribution of BS molecules is likely to differ according to the micelle morphology, thereby influencing their reactivity. In our experimental conditions, AAPH only was efficient as oxidant. Lutein and α-tocopherol significantly slowed fatty acid degradation, conversely with β-carotene. Their location within the micelle (core or border) could explain these observations. Besides, none of the tested oxidant significantly modified the catalase activity of Caco-2 cells. However, the contact with BS-based nanoemulsions significantly decreased the activity of the three tested enzymes. This effect was positively correlated with BS concentration whose conjugation revealed determining. Finally, β-carotene, lutein and retinyl acetate in micelles partly re-established catalase activity, conversely with retinol, retinyl palmitate and α-tocopherol. To conclude, IVD is an easy tool which allows independent comparisons of several parameters on micronutrient behaviour during digestion. Furthermore, the confrontation of different matrices may help to develop relevant strategies against vitamin A deficiency. Proposed nanoemulsions displayed various physical and chemical characteristics, thereby influencing their reactivity to oxidation. The antioxidant capacity of lutein and α-tocopherol could be observed in this new model. Lastly, the preliminary results on Caco-2 cells revealed some interesting interactions between micellised BS and antioxidant enzymes. Numerous questions arose that could not be addressed in this work but open perspectives for the future
Debin, Arnaud. "Formation et stabilité des triples hélices purines : études in vitro et dans les cellules de mammifères". Paris 11, 2000. http://www.theses.fr/2000PA11T013.
Texto completoTriplex-Forming Oligonucleotides (TFOs) are short nucleic acid fragments able to recognize selectively double-stranded DNA sequences. In this thesis, we have studied the formation and stability of triples helices using purine TFOs (composed of Guanines and Adenines). Firstly, we have selected double-stranded DNA sequences capable offorming stable triplexes at 20 or 5. Q. °C with corresponding 13mer purine oligonucleotides. This selection was obtained by a double aptamer approach where both the starting sequences of the oligonucleotides and the target DNA duplex were random. The results of selection were confirmed by a cold exchange method and the influence ofthe position of a 'mismatch' on the stability ofthe triplex was documented in several cases. The selected sequences obey two rules: (i) they have a high G content; (ii) for a given G content the stability of the resulting triplex is higher if the G residues lie in stretches. Secondly, triplex formation was studied in conditions mimicking potassium concentrations and temperatures in cells. In presence of 1OmM Mgcl2, KCl concentrations up to 150 mM significantly lowered both efficiency (triplex: initial duplex) and rate constants of triplex formation. For 20 mer TFO, no dissociation of triplex was observed during 24 hours either in the absence of monovalent cations or in the presence of 150 mM KCl. In this case, the negative effect of the KCl is probably due to the self-association of the oligonucleotide in competitive structures. This negative effect may be overcome by the prior formation of a short duplex either on the 3 '-or 5'- end of the 20mer TFO. We refer to these partial duplexes as 'zipper' TFOs. It was demonstrated that a 'zipper' TFO could forma triplex over the full lengh of the target, thus unzipping the short complementary strand. Thirdly, triplex stability and formation was studied in live mammalian cells. Ex vivo DMS footprint analysis after electroporation of the pre-formed into the cell have shown the presence of the triple helix inside the cells. However we were unable to show triplex formation inside cells using various methods of oligonucleotide delivery, and using various target sequences. Our results show that neither (i) chromatinization of the DNA target, (ii) intracellular K+ concentration nor (iii) cytoplasmic versus nuclear separation of the TFO and DNA target are responsible for the intracellular arrest of triplex formation. We suggest the existence of a cellular mechanism, based on a compartmentalization of TFOs and/or TFO trapping, which separates oligonucleotides from the DNA target. Further work is needed to find oligonucleotide derivatives and means for their delivery to overcome the problem of triplex formation inside cells
Pinguet, Frédéric. "Optimisation du schéma d'administration du MELPHALAN : Etudes in vitro sur des lignées cellulaires cancéreuses d'origine humaine et étude in vivo chez l'homme : [thèse soutenue sur un ensemble de travaux]". Montpellier 1, 1998. http://www.theses.fr/1998MON13515.
Texto completoRouinsard, Alexandre. "Étude du caractère de panachure et de sa stabilité lors de la micropropagation de plantes monocotylédones". Thesis, Rennes, Agrocampus Ouest, 2021. http://www.theses.fr/2021NSARC156.
Texto completoThe micropropagation of variegated cultivars (several colors on the same leaf) can generate off-type plants to the original phenotype, particularly in the case of monocotyledonous plants. However, because of their highly ornamental character, these cultivars have a strong commercial potential. The objective were to determine the micropropagation potential of variegated monocots in an industrial and commercial context, to define the stability of their phenotypes, and to understand the origin of off-types. Observations of leaf sections under a confocal laser scanning microscope on the four studied cultivars: Yucca gloriosa 'Variegata' (YgVAR), Yucca flaccida 'Golden Sword' (YflGS), Phormium tenax 'Jessie' (PtJE), and Cordyline australis 'Pink Passion' (CaPP) revealed that all cultivars were periclinal chimeras, i.e., a variegation bound to stratified meristem with several different genotypes.In micropropagation, YgVAR showed high compliance rates, PtJE moderate rates and CaPP low rates. Histological analyses on vitroplants revealed major differences in the development and in vitro propagation behavior of these three species of the order Asparagales: YgVAR developed only axillary meristems (AxM), PtJE mainly AxM and some adventitious meristems (AdM), and CaPP both AxM and AdM. While preformed axillary meristems maintain the chimeric structure, adventitious meristems maintain little. Thus, the variegation stability of these chimeras depends on their propensity to propagate by adventitious meristems. Trials to lower apical dominance and stimulate axillary meristems were conducted, as well as transcriptome analysis of different variegated tissues in YflGS. Industrial production protocols adapted to each cultivar are finally proposed
Vernier, Arnaud. "Développement instrumental en spectrométrie de masse pour le diagnostic in vitro en microbiologie clinique". Phd thesis, Université Claude Bernard - Lyon I, 2014. http://tel.archives-ouvertes.fr/tel-00986856.
Texto completoHelary, Christophe. "Hydrogels de collagène concentrés pour des substituts dermiques améliorés : évaluation in vitro et in vivo". Paris 6, 2010. http://www.theses.fr/2010PA066288.
Texto completoIbrahim, Hany. "Développement de méthodes analytiques : détermination de médicaments dans les fluides biologiques et études de stabilité de nouveaux composés antiplasmodiaux in vitro". Toulouse 3, 2008. http://www.theses.fr/2008TOU30283.
Texto completoThe analysis of compounds and/or metabolites in biological fluids needs very sensitive and selective methods for the detection and quantification in pharmacological and clinical studies. The first part of the work concerns the determination of NSAIDs in pharmaceuticals and human serum by dual-mode gradient HPLC and fluorescence detection. In addition a comparison between HPLC with conventional fluorescence, and µHPLC with laser induced fluorescence detection was carried out to determine chloroquine and quinine in human serum, using very small injected samples. This resulted in the most sensitive method known to date (LOD < 2 femtomoles). In the second part of the work, the biotransformation of new chemical entities (NCEs) showing promising antiplasmodial activity has been studied with several analytical systems including LC-MS methods. The stability of the NCEs in vitro and their interactions with human red blood cells have been investigated to begin to understand their mechanisms of action. Tagged molecules have been used to confirm the interpretation of the mass spectra and the first step in the biotransformation pathway
Gonnet, Maud. "Evaluation in vitro et in vivo de la stabilité et de la biodisponibilité de molécules liposolubles encapsulées et incluses dans une matrice modèle". Phd thesis, Université d'Angers, 2010. http://tel.archives-ouvertes.fr/tel-00538930.
Texto completoGellis, Christophe. "Optimisation de la corticothérapie pédiatrique par voie nutritionnelle parentérale : étude de stabilité de l'hémisuccinate de méthylprednisolone in vitro et études pharmacocinétiques in vivo". Clermont-Ferrand 1, 2006. http://www.theses.fr/2006CLF1PP03.
Texto completoStability and compatibility of hemisuccinate methylprednisolone with concentrations 25 to 125 µg/ml in two in one and all in one paediatric parenteral nutritive mixtures were established for a 7 days duration at the temperature of 4°C followed by 24 hours in ambient temperature. The study of pharmacokinetic parameters of hemisuccinate methylprednisolone and methylprednisolone, after administration in intravenous bolus of SOLUMEDROL® in 2 ml of various vehicles (nutritive mixtures or sodium chloride 0,9%) in New-Zealand rabbit, showed an influence of the mixtures containing a lipid emulsion. In presence of lipids the clearances of the two molecules and the volume distribution of ester of methylprednisolone are significantly reduced. During administration of SOLUMEDROL® by continuous perusion in the same nutritive mixtures for 24 hours in the animal, no signifiant difference of the pharmacokinetic parameters of methylprednisolone is highlighted. These data established the pharmacokinetic bases of an administration of SOLUMEDROL® to the child by continuous nutritive perfusion
Millerioux, Jennifer. "Formulation et évaluation de la stabilité et de l'efficacité de topiques protecteurs vis-à-vis des composés organophosphorés". Lyon 1, 2009. http://n2t.net/ark:/47881/m6v40sbv.
Texto completoPrevention of exposure to the neurotoxic organophosphorus compounds (OP) that are quickly absorbed in the skin is a major concern both for pesticide users and soldiers. Skin barrier creams are being developed to complement or replace uncomfortable chemical protective suits. The objectives of this work were to formulate and assess physicochemical stability and protective efficacy of topical skin protectant (TSP) against OP compounds. The first objective was to formulate several different TSP (emulsions, gel) and validate their physicochemical stability. The second objective was to determine the consistency of results from in vitro tests and the importance of the formulation composition in the skin protective efficacy. Quick evaluation of formulations efficacy mainly relies on in vitro tests which lead to consistent, complementary and relevant results. Our results indicated that the least effective formulations could be quickly identified by performing in vitro permeation tests with silicone membrane and by evaluating interfacial interactions between formulations and OP. We showed that a hydrogel containing specific hydrophilic polymers was by far the most effective of the formulations evaluated against VX, OP compounds, skin permeation in vitro
Namy, Patrick. "Régulation mécanique de l'angiogenèse in vitro : analyse par un modèle aux dérivées partielles des interactions cellules-substrat". Phd thesis, Université Joseph Fourier (Grenoble), 2004. http://tel.archives-ouvertes.fr/tel-00007601.
Texto completoBooij, Isabelle. "Recherche de marqueurs biochimiques en vue de la caractérisation variétale chez le palmier dattier (Phoenix dactylifera L. ), et étude de la stabilité de ces marqueurs pendant et après culture "in vitro"". Montpellier 2, 1992. http://www.theses.fr/1992MON20099.
Texto completoReinberg, Emilie. "Étude in vitro de la stabilité gastro-intestinale et de l'activité biologique de la microcine J25 : impact sur l'équilibre du microbiote colique et activité inhibitrice contre Salmonella enteritidis". Master's thesis, Université Laval, 2015. http://hdl.handle.net/20.500.11794/26502.
Texto completoMicrocin J25 (MccJ25) is a lasso-shaped bacteriocin with an antibacterial activity against Salmonella. This bacteriocin was produced and purified from the supernatant of Escherichia coli pTUC202. Its stability and biological activity in the gastrointestinal tract as well as its impact on the colonic microbiota equilibrium were studied using a continuous fermentation system with immobilized fecal microbiota simulating the physiological and microbiological conditions of the colon. Analysis of colonic microbiota by qPCR revealed no significant effect of MccJ25 on microbiota equilibrium at concentrations of 0.4, 2 et 5 μM. Antibacterial activity assays demonstrated that MccJ25 remains active against Salmonella enteritidis in the tested colonic conditions. These results are highly promising for the use of MccJ25 as an alternative to antibiotics in animals as well as in humans.
De, vaugelade du breuillac Segolene. "Évaluation des paramètres nécessaires à la détermination de la Date de Durabilité Minimale (DDM) et de la Période après Ouverture (PAO) des émulsions cosmétiques". Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLX022.
Texto completoAccording to Cosmetic Regulation 1223/2009, implemented in July 2013, the manufacturer must mention the Date of Minimum Durability (DMD), or if DMD exceeds 30 months, the Period After Opening (PAO) on the product packaging. At the present time, no text regulates the procedures applicable to the validation of a DMD or a PAO. Some guidelines are published by Cosmetics Europe, the National Agency for the safety of medicines and health products, the Scientific Committee for consumer safety, or the European Commission; but the evaluation remains at the discretion of the person responsible for marketing the product. In this context, this work proposes recommendations to establish a stability protocol in order to quickly determine the DMD. Experimental approaches on an emulsion representative of the major category in the cosmetics industry have been established. Organoleptic, physicochemical and microbiological stabilities were evaluated. The emulsion stability has been tested in accelerated conditions and in real time. A statistical approach has been proposed to evaluate the product shelf life according to its organoleptic properties. The sensory properties of the cosmetic emulsion changed differently depending on the temperature and the material in which it has been stored. A mathematical correlation between the results of studies under normal and those obtained under accelerated conditions has been proposed for some parameters. A microbiological study focused on the validation of a commercially available method, alternative to total count of aerobic microorganisms, normed by the ISO 21149 for cosmetic application. Once validated, this method has been used as an economical, quick and easy tool to evaluate the microbiological stability of cosmetic emulsions. Gas chromatography coupled with mass spectrometry was used to follow the degradation of antioxidant and preservatives. To take into account the photostability of the emulsion, an analytical strategy was proposed to identify the mechanisms involved in phototransformation reactions. The study focused on two molecules: dehydroacetic acid and alpha-tocopherol. Both gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) and liquid chromatography coupled with ultrahigh resolution mass spectrometry (LC-UHR-MS) were used for the separation and the structural identification of photoproducts. The main photoproducts were detected in the reference emulsion after UV-visible irradiation, thus showing the possible formation of photoproducts in a complex oil/water emulsion. Both in silico and in vitro toxicity tests highlighted the need for taking into account the potential formation of photoproducts in the safety evaluation of a cosmetic product
Meric, Elise. "Compréhension des effets matrices de boissons à base de jus de fruits enrichies en ingrédients protéiques sur la stabilité de ces jus et évaluation in vivo et in vitro de l'impact de cet enrichissement protéique sur le système glycémique". Thesis, Université Laval, 2012. http://www.theses.ulaval.ca/2012/29032/29032.pdf.
Texto completoPham, Andrew C. "In vitro stability of cannabinergic prodrugs in plasma". Thesis, Boston University, 2012. https://hdl.handle.net/2144/12589.
Texto completoThe endocannabinoid system has been a promising target for novel drug therapies, especially because of its role in alleviating neuropathic pain. Recent drug development has been geared to specifically target CB2 receptors to inhibit neuropathic pain without the psychotropic side effects associated with CB1 agonism. There have been problems developing oral formulations of CB2-specific cannabinergic drugs because of their low bioavailability. This issue can be addressed by creating prodrugs of these compounds with enhanced bioavailability. This study evaluates the in vitro half lives of monofunctional and bifunctional esteratic prodrug structures of two CB2-targeted cannabinergic drugs. These prodrug formulations have one or two ester bonds that must be hydrolyzed before the active drug is released. The prodrugs and active products were incubated in human, mouse, and rat plasma, as well as non-enzyme containing buffers, and concentrations were measured over time by HPLC. The active drug products were stable in all solutions. The prodrugs were found to have in vitro half lives in human plasma ranging from 2.50 to 6950 minutes and exhibited accelerated degradation in mouse and rat plasma for the majority of compounds. Non-enzymatic hydrolysis was observed in TME buffer for many of these compounds, but at a much slower rate than in the enzyme-containing plasma. Further in vivo pharmacokinetic research with these compounds will be required to evaluate their oral bioavailability and efficacy for affecting the endocannabinoid system.
Al-Ohali, Hadeel. "Factors effecting primary stability of mini-implants in vitro". Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/62763.
Texto completoDentistry, Faculty of
Graduate
Becker, Kimberly N. "In vitro stability and pharmacokinetics of novel antileishmanial compounds". Connect to resource, 2007. http://hdl.handle.net/1811/25192.
Texto completoTitle from first page of PDF file. Document formatted into pages: contains 12 p.; also includes graphics. Includes bibliographical references (p. 12). Available online via Ohio State University's Knowledge Bank.
Patel, Ramila. "Delivery and stability of antisense oligonucleotide conjugates in vitro". Thesis, Aston University, 1998. http://publications.aston.ac.uk/10983/.
Texto completoRobson, Alice. "In vitro reconstitution and stability of a beta-adrenergic receptor". Thesis, University of Bristol, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.424005.
Texto completoCostanzo, Jerry Lee. "In vitro comparison of methylene diphosphonate radiopharmaceuticals". Scholarly Commons, 1985. https://scholarlycommons.pacific.edu/uop_etds/484.
Texto completoAzhakathu, Anisha Tresa. "In vitro characterization of the primary stability of acetabular hip implants". Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/18853/.
Texto completoPotter, Robert Henry. "Genetic stability of potato (Solanum tuberosum L.) after in vitro culture". Thesis, Imperial College London, 1990. http://hdl.handle.net/10044/1/46510.
Texto completoWoodward, G. "Anthocyanin stability, metabolic conjugation and in vitro modulation of endothelial superoxide production". Thesis, University of East Anglia, 2010. https://ueaeprints.uea.ac.uk/25829/.
Texto completoNieuwoudt, Stephnie. "Preparation, stability and in vitro evaluation of liposomes containing chloroquine / Stephnie Nieuwoudt". Thesis, North-West University, 2010. http://hdl.handle.net/10394/4740.
Texto completoThesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2011.
Zhang, Xiaoqin. "Polysialylated liposomes : preparation, characterisation and stability studies in vitro and in vivo". Thesis, University College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313513.
Texto completoDI, FELICIANTONIO MARINA. "Studio in vitro sulla stabilità strutturale dei cannabinoidi sintetici nel fluido orale". Doctoral thesis, Università Politecnica delle Marche, 2018. http://hdl.handle.net/11566/253005.
Texto completoIn the last decade the illegal drug market has seen the birth, first, and the affirmation, then, of synthetic substances much more dangerous than traditional drugs. In 2012 the Commission on Narcotic Drugs classified them under the term NPS or "New Psychoactive Substances", legally marketed as environmental fragrances named "Spice". Chemical-toxicological results have highlighted the presence, in this products, of synthetic cannabinoids particularly affine to CB1 cannabinoid receptors. The aim of the research was to evaluate the structural stability of these molecules when subjected to a change of the physical state due to the high temperatures reached during the smoking process. The attention was drawn to saliva, the biological matrix immediately involved in the smoking process, characterized by non-invasive sampling and which allowed obtaining reliable and repeatable data in high-resolution mass spectrometry. The highly lipophilic structure of the molecules requires the use of glass containers, in order to avoid adsorption on the surface of polypropylene tubes, while the storage temperature to which the biological matrix is subjected influences the potential degradation of synthetic cannabinoids by salivary and/or microbial enzymes. The results obtained show a certain structural stability of the molecules under investigation, but the analytical data obtained, usable both in the clinical and forensic field, must comply with a strict analytical/instrumental protocol.
Leib, Nicholas. "Modélisation du comportement impactant d'un ensemble câble-gaine dans le domaine fréquentiel : Application aux commandes à câbles". Ecully, Ecole centrale de Lyon, 2008. http://bibli.ec-lyon.fr/exl-doc/TH_T2151_nleib.pdf.
Texto completoIn this thesis we study the dynamic behavior of a vehicle’s gearshift cables. To ensure proper assembly and functioning of the pieces, there are clearances in the system. The latter cause a vibro-impacting phenomenon, called tizzing, that can bother the driver. The aim of this work, done in collaboration with PSA Peugeot-Citroën, is to understand the sources of cable tizzing, and predict its presence in different configurations. The first part is devoted to presenting the different methods used to solve a nonlinear problem in the frequency domain. A method to determine the frequency response on a car motor’s bandwidth is presented and an approach to estimate the high frequency content after a harmonic balance is proposed. These methods are applied on a simple vibro-impacting system. The next part presents the different experiments that were conducted to determine the source of cable tizzing and identify the physical characteristics of the cable and its protective housing. A experimental testbench served as a reference to validate a finite element model. Then, the model is presented and the correlation results are shown. A criterion is proposed and helps establish whether or not, the system is going to tizz. Finally, the latter is used to compare the tizzing level on different vehicle configurations
Maccari, Flavia Lima Ribeiro [UNESP]. "Avaliação da atividade antiproliferativa in vitro, liberação, permeação e retenção cutânea in vitro e estabilidade de emulsões contendo (-)- Terpinen-4-OL". Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/96248.
Texto completoCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Universidade Estadual Paulista (UNESP)
O terpinen-4-ol é o principal componente da M. alternifólia, apresenta atividade antiinflamatória, antibacteriana e antifúngica; em estudos recentes in vitro a atividade antineoplásica para linhagens celulares de melanoma (M14) foi demonstrada. O objetivo específico deste trabalho foi verificar a atividade farmacológica in vitro dos isômeros óticos (-) terpinen-4-ol e (+) terpinen-4-ol e do óleo de Melaleuca alternifolia em nove linhagens diferentes de células tumorais, incluindo a célula UACC-62 do melanoma que ainda não havia sido estudada, e a concentração eficaz para o desenvolvimento de formulação que possa ter ação contra o melanoma. Após realização dos ensaios farmacológicos in vitro verificou-se que o (-)terpinen-4-ol apresentou melhor atividade nas linhagens celulares de melanoma, sendo o princípio ativo de escolha para as duas formulações que foram desenvolvidas, testadas e comprovadas a qualidade e estabilidade. Para caracterização das formulações foram efetuados os ensaios reológicos, sendo comprovado que as emulsões desenvolvidas são adequadas para o uso tópico no que diz respeito às suas características reológicas, sendo que as duas apresentaram comportamento de fluxo semelhante, diferindo apenas na área de histerese. Posteriormente foram feitos testes de permeação e retenção cutânea in vitro, para verificar qual formulação permite que o princípio ativo atinja em maior concentração a camada de interesse para atividade contra o melanoma. O método proposto para quantificação do (-)-terpinen-4-ol foi validado e utilizado nos ensaios de estabilidade acelerada, liberação, permeação e retenção cutânea in vitro. Os ensaios de liberação demonstraram que as duas formulações apresentam cinética de zero ordem, com fluxo de 14,62 µg/cm2 /h para formulação 1 e de 6,70 µg/cm2 /h para formulação F2. Na retenção cutânea...
The terpinen-4-ol is the major component of M. alternifolia, has anti-inflammatory, antibacterial and antifungal, in recent studies in vitro anticancer activity for melanoma cell lines (M14) was demonstrated. The specific objective of this study was to assess the in vitro pharmacological activity of optical isomers (-) terpinen-4-ol and (+) terpinen-4-ol and oil of Melaleuca alternifolia in nine different tumor cell lines, including cell UACC -62 melanoma that had not yet been studied, and effective concentration for the formulation development that may have action against melanoma. After performing the in vitro pharmacological tests showed that the (-) terpinen-4-ol showed better activity in melanoma cell lines, with the active ingredient of choice for the two formulations were developed, tested and proven quality and stability. For characterization of the formulations were made the rheological tests and confirmed that the developed emulsions are suitable for topical use in relation to their rheological characteristics, and the two had similar flow behavior, differing only in the area of hysteresis. Subsequent tests were performed permeation and skin retention in vitro, to determine which formulation allows the active ingredient reaches higher concentration in the layer of interest for activity against melanoma. The proposed method for quantification of (-)-terpinen-4-ol was validated and used in accelerated stability testing, release, skin permeation and retention in vitro. The release assays demonstrated that both formulations have zero order kinetics at a rate of 14.62 g/cm2/h for formulation 1 and 6.70 g/cm2/h for formulation F2. In vitro skin retention was found that the F1 showed retention of terpinen-4-ol smaller in the stratum corneum, compared to F2. Conversely, the retention in the epidermis over the dermis of terpinen-4-ol was higher in F1. It was found that formulation F1 ... (Complete abstract click electronic access below)
Omer, Khaled A. E. "An in-vitro evaluation of resonant frequency analysis to measure fixed bridge stability". Thesis, University of Liverpool, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.570458.
Texto completoScholtz, Jacques Coenraad. "Preparation, stability and in vitro evaluation of liposomes containing amodiaquine / Jacques C. Scholtz". Thesis, North-West University, 2010. http://hdl.handle.net/10394/4878.
Texto completoThesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2011.
Ferreira, Pedro Garcia. "Insights into human carboxylesterase 2 stability and activity in vivo and in vitro". Master's thesis, Faculdade de Ciências e Tecnologia, 2012. http://hdl.handle.net/10362/8141.
Texto completoDue to its role in ester containing xenobiotics metabolization, such as the activation of pro-drugs, carboxylesterase 2 (CES2) has become an attractive enzyme, with potential applications in the field of chemotherapy. Still, it hasn’t been as thoroughly characterized as the other main human carboxylesterase, the carboxylesterase 1 (CES1), having no described structure yet. The original hypothesis being tested in this work was the possibility of enzyme-enzyme interaction that had been suggested from previous work in the host laboratory. The initial task of this project was therefore to further assess CES2 stability and to test possible enzyme-enzyme interaction with CES1, by characterizing enzyme hydrolytic kinetics in different assay conditions and evaluating the behaviour of enzyme mixtures. Different CES2 activity rates were observed when tested in different reaction conditions suggesting a stabilizing/destabilizing effect on the enzyme, but evidence of in vitro interactions was not confirmed. Considering the dependence of conclusions on test methods as well as the extreme care measures that have to be taken for avoiding enzyme degradation during the preparation of cell extracts, a second goal was envisaged for this project. This consisted in the development of a new method capable of determining CES activity in conditions closer to those that are found physiologically. A new spectrofluorometric method able to assess carboxylesterase activity in intact living cells, using loperamide as a specific CES2 inhibitor and Bis(4-nitrophenyl) phosphate as a total carboxylesterase inhibitor was therefore developed and applied to Caco-2, HT-29. Hep G2 and HEK-293T cell lines. The method proved itself capable of detecting CES total activity in living cells, as well as to differentiate between CES2 and other CES activities. Differences were shown between this and the traditional methods using cell extracts, suggesting that the latter may not be the best option when trying to predict in vivo CES behavior.
Fundação para a Ciência e Tecnologia - (PTDC/EBB-BIO/111530/2009, PEst-OE/EQB/LA0004/2011)
Lai, Stephen Val. "EFFECTS OF CELL PASSAGE IN VITRO ON THE STABILITY OF TUMOR KARYOTYPE (CANCER)". Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275311.
Texto completoTirand, Loraine. "Ciblage de neuropiline-1, co-récepteur du VEGF, pour potentialiser l'effet anti-vasculaire de la Thérapie PhotodynamiqueUne étude de stabilité de la molécule conjuguée a été réalisée in vitro et in vivo. Si le peptide est relativement stable jusqu'à 4h après injection intraveineuse in vivo, l'utilisation de pseudo-peptides plus résistants aux peptidases permettrait une efficacité encore supérieure". Phd thesis, Université Henri Poincaré - Nancy I, 2007. http://tel.archives-ouvertes.fr/tel-00198834.
Texto completoUn nouveau PS couplé à un heptapeptide (ATWLPPR) ciblant neuropiline-1, un co-récepteur du VEGF, a été synthétisé. Ce couplage ne modifie pas les propriétés photophysiques du PS.
Une étude in vitro sur cellules endothéliales de veine ombilicale humaine a montré une moindre cytotoxité à l'obscurité, une amélioration de l'incorporation intracellulaire et une meilleure activité photodynamique, suite au couplage du PS au peptide.
In vivo, chez des souris nude porteuses de gliomes malins humains, le PS conjugué s'accumule dans la tumeur à des taux supérieurs à ceux retrouvés dans la peau. En utilisant des conditions (dose de PS, fluence et irradiance lumineuses) optimisées par une approche de plan d'expériences, la PDT avec le PS couplé au peptide induit une réduction du flux sanguin pendant traitement, comparé au PS non couplé, une destruction des cellules endothéliales des vaisseaux sanguins, 24h après PDT, ainsi qu'un retard de croissance tumorale, statistiquement significatif comparé au PS non couplé.
Baby, André Rolim. "Avaliação in vitro da permeabilidade cutânea da rutina em emulsões cosméticas". Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/9/9139/tde-25102013-153334/.
Texto completoRutin is employed as antioxidant and to prevent the capillary fragility and, when incorporated in cosmetic emulsions, it must target the action site. In vitro cutaneous penetration studies through human skin is the ideal situation, however, there are difficulties to obtain and to maintain this tissue viability. Among the membrane models, the shed snake skin presents itself as pure stratum corneum, providing barrier function similar to human and it is obtained without the animal sacrifica. The objectives of this research were: (1) development and stability evaluation of cosmetic emulsions containing rutin and penetration enhancers, as urea (U), isopropanol (IP) and propylene glycol (PG); (2) release evaluation of the mentioned active substance from the emulsions and; (3) evaluation of rutin in vitro cutaneous penetration and retention from the emulsion of the best performance. Emulsions were developed with rutin 5.0% w/wand U, IP and PG, associated or not according to factorial design with two levels and central point. Active substance on the formulations was quantified by a validated spectrophotometric method at 361.0 nm. Rutin release from emulsions was performed in vertical diffusion cells with cellulose acetate membrane and distilled water and ethanol 99.5% (1:1), as receptor fluid. The experiment was conducted for six hours, at 37.0 ± 0.5 °c with constant stirring of 300 rpm. Formulation with best profile of rutin release had its stability studied by the Accelerated Stability Assays. Rutin cutaneous penetration and retention from the mentioned emulsion was performed with shed snake skin from Crotalus durissus. Spectrophotometry at 410.0 nm, previously validated, determined the active substance after release and cutaneous penetration/retention. Ali emulsions were considered apparently stables after development. Urea (isolated and associated with IP and PG) and isopropanol (isolated and associated with PG) have influenced negatively the rutin release in several parameters. Emulsion with PG 5.0% w/w presented rutin released and accumulated equal to 648.80 ± 53.01 µg/cm2. Unexpectedly, the formulation containing all enhancers (U 5.0% w/w, IP 5.0% w/w and PG 5.0% w/w) has decreased the amount released of the active substance (419.76 ± 17.98 µg/cm2). Emulsion with PG presented more adequate for rutin release, but PG did not provide rutin cutaneous penetration through C. durissus skin, retaining 0.931 ± 0.0391 &$181;g rutin/mg shed snake skin. The referred formulation was chemically stable for 30 days after they have been stored at 25.0 ± 2.0 °c, 5.0 ± 0.5 °c and 45.0 ± 0.5 °C. In conclusion, emulsion with PG provided rutin release more expressively, although, it has not been verified the active cutaneous penetration, but only its retention on the Crotalus durissus stratum corneum. Formulation was stable in all storage conditions.
Linsalata, Mariateresa. "In vitro assessment of the primary stability of the acetabular component in hip arthroplasty". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/15551/.
Texto completoBicknell, Ryan T. "All-metal glenoid component design in shoulder arthroplasty, an in vitro implant stability study". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ30757.pdf.
Texto completoWatson, Neil Michael. "The design and synthesis of polyvalent gene delivery vehicles and polyplex stability in vitro". Thesis, University of Strathclyde, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.435115.
Texto completoNguyen, Minhthy Le. "Physical and Chemical Stability of All-Trans Lycopene and Other Tomato Carotenoids in Vitro". The Ohio State University, 1999. http://rave.ohiolink.edu/etdc/view?acc_num=osu1392643300.
Texto completoMorosato, Federico <1991>. "In vitro biomechanical testing of the stability of primary and revision hip acetabular implants". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amsdottorato.unibo.it/9394/1/Morosato_Federico_tesi.pdf.
Texto completoBotti, Laura Costa Moreira 1967. "Propriedades de barreira em sistemas de embalagem para azeite de oliva". [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255958.
Texto completoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Considerada a principal causa de perda da qualidade em óleos e gorduras, a oxidação leva à formação de sabores e odores indesejáveis, perda de funcionalidade e valor nutricional em especial do azeite de oliva (AO). Assim, o objetivo deste trabalho foi avaliar a eficiência de embalagens de vidro (transparente e âmbar) e polietileno tereftalato (PET) aliado à tecnologia de barreira ao oxigênio e à radiação UV, como opção à manutenção da estabilidade do AO. Inicialmente foi feita a caracterização dos materiais, seguida do envase das amostras e estocagem de metade delas em caixas de papelão mantidas na ausência de luz. Ao mesmo tempo, a outra metade foi exposta à iluminação intermitente por períodos de 12h e intensidade luminosa de 1000 lux durante seis meses. Ao longo do tempo foram feitas as seguintes análises: acidez, índice de peróxido, cor L*a*b*, cor Lovibond, extinção específica a 232 (K232) e 270nm (K270), clorofila, carotenoides, fenóis totais e ?-tocoferol. Durante o período analisado, houve aumento da acidez, índice de peróxido, K232 e K270 para todas as amostras, sendo as embalagens convencionais transparentes as mais susceptíveis e a condição sob iluminação a mais crítica. Em contrapartida, a cor, o teor de clorofila, carotenoides e fenóis totais foram reduzidos com o tempo e também sofreram influência da luz e do material de embalagem. A degradação do ?-tocoferol foi influenciada até o segundo mês pelas condições de estocagem e tipo de material da embalagem. A partir de então, os índices de tocoferol foram reduzidos de forma drástica em todos os sistemas de embalagem e provavelmente não foram detectados pela metodologia. De forma geral, sob o abrigo da luz, tanto a embalagem de PET com barreira ao oxigênio como o vidro foram efetivas nos primeiros meses, mostrando-se como opção para produtos que não necessitem de elevada proteção. Entretanto, a embalagem de vidro âmbar mostrou-se a mais eficiente devido a suas características intrínsecas e ao amplo espectro de proteção para amostras quando expostas à luz. A partir dos resultados, conclui-se que aditivos do tipo estabilizantes de radiação UV não foram efetivos nas condições de estudo, porém o uso de absorvedores de oxigênio aliado a tecnologia de blendas pode ser uma alternativa para a área de embalagens de azeite e óleos. Assim, é essencial que se pense no uso complementar de diferentes tecnologias em prol da manutenção da qualidade e estabilidade dos alimentos
Abstract: he oxidation is considered the main cause of quality loss in oils and, consequently, leads to the formation of undesirable flavors and odors, loss of nutritional value and functionality in particular olive oil (OO). This work aimed to evaluate the efficiency of glass containers (clear and amber) and polyethylene terephthalate (PET) combined with the improvement of oxygen barrier technology and UV radiation, as an option to maintain the stability of OO. At first, the materials were characterized, the samples were bottled and then half of them stored in cardboard boxes kept in the dark. At the same time, the other half was exposed to intermittent periods of 12 hours light and light intensity of 1000 lux for six months. Acidity, peroxide value, color L * a * b *, color Lovibond, specifc extinction at 232 (K232) and 270nm (K270), chlorophyll, carotenoids, total phenols and ? ¿ tocopherol were analyzed over time. During the reporting period, there was an increase in acidity, peroxide value, K232 and K270 for all samples, with the conventional transparent packaging being the most susceptible and the illumination condition, the most critical. In contrast, the color, chlorophyll content, carotenoids and total phenolics were reduced with time and were also affected by light and the packaging material. The degradation of ?-tocopherol was influenced by storage conditions and type of packaging material until the second month. Thereafter, the tocopherol levels were reduced drastically in all packaging systems and probably were not detected by the methodology. In general, in the dark, both the PET packaging with oxygen barrier such as glass were effective in the first months, showing as an option for products that do not require high protection. However, the amber glass packaging due to their inherent and broad-spectrum protection from light features proved to be the most efficient when exposed to light. The results evaluation of this research showed that the stabilizing additive type of UV radiation were not effective under the conditions of study, but the use of oxygen absorbers combined with blends technology can be an alternative to the oil packaging. Thus, it is essential to think about the complementary use of different technologies for the maintenance of the quality and stability of food
Mestrado
Tecnologia de Alimentos
Mestra em Tecnologia de Alimentos
Venter, Telanie. "Formulation, in vitro release and transdermal diffusion of vitamin B3 for treatment of acne / Telanie Venter". Thesis, North-West University, 2009. http://hdl.handle.net/10394/3984.
Texto completoThesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2010.
BOS, MARIE-ANDREE. "Procyanidines de tormentille : standardisation d'un extrait ; proprietes antiradicalaires ; formulations d'hydrogels : essais de stabilite et de diffusion in vitro". Clermont-Ferrand 1, 1996. http://www.theses.fr/1996CLF1PP05.
Texto completoMoraes, Carla Aparecida Pedriali. "Síntese e avaliação da segurança in vitro da rutina e do succinato de rutina visando sua incorporação em formulações fotoprotetoras eficazes associados a filtros químicos e físico". Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/9/9139/tde-07032013-092315/.
Texto completoThe current cosmetic market trend is to develop products containing vegetables raw materials. This work proposed to use the Technology of Green Chemical to increase the rutin stability in cosmetic formulas as regards of its antioxidant and photoprotective properties. The chemical synthesis was realized by the introduction of carboxylate groups on sugar moiety of rutin producing in rutin succinate. This derivative and/or rutin were incorporated into 74 test formulas. After the undergoing to preliminary and accelerated stabilities under different temperature and humidity conditions were selected 12 formulas (O/W emulsions). Emollient agents and silicones were used to improve the solubility and/or dispersion of the chemical and physical filters. The second stage of this work was to evaluate the safety of rutin succinate, rutin used as an internal standard, using the alternative method of in vitro toxicity, the XTT. After the screening of tested concentrations, the concentrations of the samples with the lowest level of cell death were 0.1% or 1 mg/mL (rutin) and 0.4% or 4 mg/mL (rutin succinate), respectively. According to results obtained in accelerated stability testing, the formulations containing rutin succinate in combination or not with UV filters in both O/W emulsions (A - Crodafos®CES + Uniox®C and B - Hostacerin®SAF) were selected for the long term stability test. In this test the sunscreens were evaluated in the following parameters: the organoleptic properties (appearance, color and odor), physico-chemical aspects (pH value and viscosity) and functional (antiradicalar activity and in vitro photoprotection efficacy). The results presented by the MS formula (rutin succinate associated with physical filter and chemical filters) were: uniformity, stability of color and odor at room temperature and showed no significant difference, as well stability in: pH and SPF (Sun Protection Factor) values, hysteresis area, antiradicalar activity. These results were observed mainly when it was incorporated to O/W emulsion A (90 days of analyses at 45°C and 75% humidity, 5°C and 25°C). It was observed the functionality of MS association was more stable, maintaining photoprotective efficacy and within their rheological properties could be more accepted by consumers.
Moolman, Judith Margaretha. "Formulation, in vitro release and transdermal diffusion of azelaic acid with topical niacinamide / J.M. Moolman". Thesis, North-West University, 2010. http://hdl.handle.net/10394/3987.
Texto completoThesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2010.
Jiang, Hongcheng. "Fabrication and characterization of microporous calcium phosphate coatings and in vitro evaluation of chemical stability". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ63317.pdf.
Texto completoLi, Weiqi. "The endothelial glycocalyx : recovery, stability and role in electric field-directed cell migration in vitro". Thesis, Queen Mary, University of London, 2014. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8942.
Texto completoGupta, Antje. "In-vivo und In-vitro-Stabilität und Metabolismus von Gemischtligandkomplexen des 99m Tc". Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2000. http://nbn-resolving.de/urn:nbn:de:swb:14-994673277281-08594.
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