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Gonzalez, Galvan Laura Patricia. "Materialisation de la candela (unité d'intensité lumineuse dans le système international); à l'aide de photomètres dont la chaîne de raccordement au radiomètre cryogénique primaire est parfaitement établie." Paris, CNAM, 2005. http://www.theses.fr/2005CNAM0512.
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La définition la plus récente de la candela, adoptée en 1979 par la 16ème Conférence Générale des Poids et Mesures est la suivante : La candela est l’intensité lumineuse, dans une direction donnée, d’une source qui émet un rayonnement monochromatique de fréquence 540 x 10[puissance]12 hertz et dont l’intensité énergétique dans cette direction est de 1/683 watt par stéradian. Cette définition ne donne pas de méthode pratique pour sa réalisation, elle ne donne qu’une relation directe entre les grandeurs photométriques et les grandeurs radiométriques. Depuis plusieurs années, les mesures radiométriques ont connu un développement important, et une réduction notable des incertitudes grâce au développement des radiomètres cryogéniques à substitution électrique, qui servent de références radiométriques. Il est donc logique de rattacher la réalisation de la candela aux mesures radiométriques faites avec le radiomètre cryogénique. La matérialisation de la candela est faite actuellement à l’utilisation de photomètres. Les photomètres sont composés de 3 composants : détecteur, filtre et diaphragme. Le détecteur utilisé peut être un seul détecteur ou un détecteur piège, lequel est composé de trois détecteurs placés de façon à ce que les pertes par réflexion soient minimes. Le filtre V(lambda), correspondant à la vision photopique, est réalisé à l’aide d’une combinaison de verres présentant différents facteurs de transmission. Le diaphragme est utilisé pour délimiter la quantité de lumière qui arrive sur le photomètre. Dans ce travail nous avons utilisé des détecteurs pièges qui ont une traçabilité au radiomètre cryogénique. De cette manière nous obtenons la sensibilité du détecteur piège aux longueurs d’onde des lasers employés. En utilisant comme étalon un détecteur non sélectif, nous obtenons la sensibilité spectrale de ces mêmes détecteurs pièges sur l’intervalle de mesure de 380 nm à 780 nm. Les filtres V(lambda) sont mesurés pour obtenir leur facteur de transmission dans le même intervalle. La surface du diaphragme est obtenue en utilisant la méthode des moindres carrés à partir des mesures des points des bords du diaphragme avec une table micrométrique. Ces trois éléments étant caractérisés, nous faisons le calcul du facteur d’adaptation spectral du photomètre et nous utilisons l’équation du corps noir de Planck pour obtenir le flux énergétique de l’illuminant utilisé. La sensibilité lumineuse du photomètre est égale à la sensibilité du photomètre à 555 nm divisée par, le produit de l’efficacité lumineuse maximale et du facteur d’adaptation spectral. Cette valeur de la sensibilité lumineuse est donnée en unité de courant électrique divisée par le flux lumineux. Comme nous connaissons la surface du diaphragme nous calculons l’éclairement lumineux qui arrive sur le photomètre. En utilisant le loi de l’inverse carré de la distance nous trouvons l’intensité lumineuse de la source. Le travail exposé dans ce document décrit la réalisation pratique de l’unité d’intensité lumineuse, la candela, effectuée à l’Institut National de Métrologie du Conservatoire National des Arts et Métiers et son raccordement au radiomètre cryogénique, meilleure référence actuelle des mesures radiométriquesThe most recent definition of the candela, adopted in 1979 by the 16th General Conference of the Weights and Mesures is the following : The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540 x 10[to the power of]12 hertz and that has a radiant intensity in that direction of 1/683 watt per steradian. This definition doesn’t give any practical method for its realization, but only a direct relation between the photometric quantities and the radiometric quantities. Since several years, radiometric measurements have known a significant development, and a notable reduction of uncertainties thanks to the development of the electrically calibrated cryogenic radiometers, which are used as radiometric reference. For this reason it is logical to connect the realization of the candela to the radiometric measurements carried out with the cryogenic radiometer. The materialization of the candela is actually done with the use of photometers. The photometers are composed by 3 components : detector, filter and aperture. The detector can be a single detector or a trap detector, which is composed by three detectors placed in the way to get minimal losses by reflexion. The V(lambda) filter, corresponding to the photopic vision, is produced using a combination of glasses that present diferent transmittances. The aperture is used to delimit the quantity of light entering inside the photometer. In this work we used trap detectors which have traceability to the cryogenic radiometer. In this way we had the responsivity of the trap detector in 3 differents lasers wavelengths. Using as a standard a non selective detector , we obtained the relative spectral responsivity of these trap detectors in the range of 380 nm to 780 nm. The V(lambda) filters have been measured to get their transmitance in the same range. The surface of the aperture has been measured thanks to a micrometric table and contactless method. With this three elements charaterized, we can calculate the mismatch correction factor of the photometer and we used the equation of the black body of Planck to obtain the radiant energy flux of the illuminant. The luminous responsivity of the photometer is equal to the responsivity of the photometer at 555 nm divided by, the product of the constant of luminous efficacy and the mismatch correction factor. This value of luminous responsivity is given in units of electrical current divided by luminous flux. As we know the surface of the aperture, we can calculate the illuminance of the photometer. Using the inverse square law of the distance, we can find the luminous intensity of the source. The work presented in this document describe the practical realisation of the unit of luminous intensity, the candela, done at the Institut National de Metrologie du Conservatoire National des Arts et Métiers, and its traceability to the cryogenic radiometer, the best actual standard for radiometric measurements
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Starczewski, Jerzy Andrzej. "Felix Candela : the structure and form of reinforced concrete shells." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/22954.
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Pulat, Arpat, and Tayierjiang Zaierding. "En jämförelsestudie av fritidsbåtar mellan The Candela Seven och AMT 230 GP." Thesis, KTH, Hållbar produktionsutveckling (ML), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-292202.
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Detta examensarbete går ut på att utföra en analys i form av en jämförelsestudie av två fritidsbåtar med funktions, ekonomisk samt hållbarhetsaspekter i fokus. Projektet utgår samt är inriktad på en eldrivenbärplansbåt The Candela Seven från elmotorbåtsproducent Candela Speed Boat AB där båten jämförs med motorbåten AMT 230 GP från Advanced Marine Tech Premium Boats och utvärderas dels med hjälp av Havsmiljöinstitutets samarbete mellan olika institutioner i Sverige som referensram. Projektmålen är att genom analys och utvärderingar av jämförelsearbete utse båten som ska prioriteras mellan Candela Seven och AMT 230 GP samt komma med eventuella rekommendationer ur funktions-, ekonomiska samt hållbarhetsperspektiv. Arbetet startade med en nulägesanalys för att skapa insikt i produktfunktionalitet av båtarna, vilka ekonomisk och hållbarhetsfördelar produkten har samt hur marknaden ser ut för elbåtar med kundbehov i fokus. För vidareanalys av insamlade data och fakta för jämförelsearbete genomfördes SWOT- och kvantitativa analysmetoder samt genom matematiska resonemang och analyser identifiera båtens egenskaper och fördelar jämfört med konkurrenten. I jämförelseanalys används jämförelsematris för värdering och sammanställning av olika parametrar mot varandra samt utse båten som ska prioriteras. I jämförelseanalysen med olika parametrar visades Candela Seven är en gynnsammare båt att välja eller köpa och som prioriteras i jämförelse med AMT 230 GP. Fokus kan bli att hitta flera kunder som är intressanta, eller produktanpassa för att uppfylla kunders önskemål. Nulägesanalys genomfördes som visar att en huvudkonkurrent med bensindriven båt identifierades samt är ett substitut som utmanar produkten. Utmärkta egenskaper från SWOT och Kvantitativa-analysen är att Candela Seven är energisparande samt lönsammare att driva med mindre underhåll jämfört med AMT 230 GP. Dessutom är produkten miljövänligare i körning med hållbarhetstänkande egenskaper och design.This thesis is based on performing an analysis in the form of a comparative study of two leisure boats with functional, economic and sustainability aspects in focus. The project is based and focuses on an electric hydrofoil boat The Candela Seven from electric motorboat manufacturer Candela Speed Boat AB where the boat is compared with the motorboat AMT 230 GP from Advanced Marine Tech Premium Boats and evaluatedpartly with the help of the Institute of Marine Environment's cooperation betweendifferent institutions in Sweden as a reference framework. The project goals are to, through analysis and evaluations of comparative work,designate the boat that will be prioritized between Candela Seven and AMT 230 GP andgive eventual recommendations from a functional, financial and sustainabilityperspective. The work started with a current situation analysis to create insight into the productfunctionality of the boats, what economic and sustainability benefits the product hasand what the market looks like for electric boats with customer needs in focus. Forfurther analysis of collected data and facts for comparative work, SWOT andquantitative analysis methods were performed and through mathematical reasoning andanalyzes to identify the boat's properties and advantages compared to the competitor. In comparison analysis, a comparison matrix is used for valuation and compilation ofdifferent parameters against each other and to designate the boat to be prioritized.In the comparison analysis with various parameters, Candela Seven was shown to be amore favorable boat to choose or buy and which is prioritized in comparison with theAMT 230 GP. The focus can be on finding more customers that are interesting, orproduct adaptation to fulfill customer needs. The current situation analysis was carried out which shows that a main competitor witha petrol-powered boat was identified and is a substitute that challenges the product.Excellent features from the SWOT and Quantitative analysis are that Candela Seven isenergy-saving and more profitable to operate with less maintenance cost compared to the AMT 230 GP. In addition, the product is more environmentally proficient whendriving with sustainability-thinking properties and design.
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KATNAH, ACHRAF. "Une nouvelle materialisation de l'unite d'intensite lumineuse la candela a partir du radiometre cryogenique." Paris, CNAM, 1997. http://www.theses.fr/1997CNAM0294.
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A l'inm une realisation de la candela a ete faite a partir d'un radiometre a substitution electrique (rse) et d'un filtre correcteur v() (fcv()) pour mesurer l'intensite lumineuse (il) des lampes etalons. L'incertitude type relative ((i)) etait de 0,3% a 1. Elle est due aux proprietes physiques du rse. Le nouveau photometre (phm) etalon utilise une photodiode (phd) au si qu'on peut etalonner en sensibilite spectrale absolue (ssa) par rapport au radiometre cryogenique (rc) a quelques 0,01% pres, ce qui devrait reduire (i). Nous avons choisie la phd hamamatsu s3204-03 (de type stable dans le temps) comme detecteur a utiliser dans le phm. Elle a montre des caracteristiques interessantes en linearite, en sensibilite spectrale relative (ssr) et locale. Sa ssr a ete adaptee en realisant un fcv(), en verres colores colles, pour que la ssr de l'ensemble s'approche de la courbe theorique v() de la c. I. E. . La ssr du phm a ete evaluee sur tout le domaine spectrale visible en combinant la ssr de la phd, la transmission spectrale relative du fcv() et le facteur d'intereflexion entre le filtre et la phd. La courbe de la ssr ainsi obtenue a ete comparee a la courbe v() pour determiner le fas du phm realise. Nous avons mesure la ssa du phm par rapport au rc en utilisant des sources lasers. Ces mesures ont ete utilisees pour calculer la sensibilite lumineuse correspondante du phm en tenant compte des facteurs de correction lies au fait que le phm a une ssr differente de la courbe v(). Finalement, en utilisant la sensibilite lumineuse moyenne du phm ainsi que son fas nous avons mesure l'il de quelques lampes etalons. L'incertitude provisoire (i) obtenue avec la nouvelle realisation est estimee a 0,42% a 1. L'incertitude principal vient de la determination de la ssr du phm. Des propositions ont ete faites pour ameliorer sa determination et reduire (i).
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Devanz, Guillaume. "Etude numérique et expérimentale de la dynamique du faisceau du photoinjecteur CANDELA et instrumentation associée." Phd thesis, Université Pierre et Marie Curie - Paris VI, 1999. http://tel.archives-ouvertes.fr/tel-00006568.
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Candela, Andrade Mario [Verfasser]. "Patellar luxation and concomitant cranial cruciate ligament rupture in small breed dogs / Mario Candela Andrade." Berlin : Freie Universität Berlin, 2020. http://d-nb.info/121092563X/34.
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DEVANZ, GUILLAUME. "Etude numerique et experimentale de la dynamique du faisceau du photo-injecteur candela et instrumentation associee." Paris 6, 1999. http://www.theses.fr/1999PA066154.
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Les canons radio-frequence declenches par laser font partie des sources d'electrons les plus brillantes, permettant d'atteindre les performances requises pour les applications les plus exigeantes que sont les collisionneurs lineaires electrons/positrons et les lasers a electrons libres aux courtes longueurs d'onde. Candela est un photo-injecteur en bande s declenche par un laser sub-picoseconde. Il permet de d'atteindre des courants crete de l'ordre de la centaine d'amperes pour une energie moyenne superieure a 2 mev. La conception originale des deux cavites acceleratrices vise la minimisation des emittances transverses et longitudinale selon les principes enonces par gao. Pour des considerations pratiques, les parametres de fonctionnement, en particulier la duree de l'impulsion laser, ne correspondent pas a ceux qui avaient ete envisages lors de la conception. Des simulations numeriques ont donc ete effectuees pour evaluer les performances du canon dans la situation experimentale. La recherche d'un fonctionnement stable de l'injecteur a donne lieu a des evolutions consequentes dans les systemes d'asservissement de phase faisant intervenir le laser et la source hf. Les caracteristiques transverses et longitudinales du faisceau ont ete mesurees en fonction des parametres principaux que sont la charge du faisceau et la phase entre le laser et l'onde hf. Des mesures d'emittance transverse, dispersion en energie et durees de paquets sont presentees pour plusieurs configurations de l'injecteur. Les systemes de mesure du faisceau existants ont ete etudies pour determiner leur resolution, les conditions experimentales a satisfaire, enfin suggerer des ameliorations a apporter pour les adapter au cas particulier du faisceau de candela. L'ensemble des experiences sur le faisceau a ete compare aux simulations numeriques. De cette confrontation ressort un accord sur de larges plages de parametres pour la plupart des grandeurs caracteristiques du faisceau.
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Gentile, Federico. "Sviluppo di una rondella piezoelettrica per la stima della pressione nel cilindro." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/20058/.
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In-cylinder pressure measurement allows for the obtainment of fundamental information for the reduction of pollutant emissions and for the control of the combustion process, especially in applications characterized by unstable combustion such as LTC (Low Temperature Combustion), where an on-board combustion monitoring system is required.
The aim of this thesis was the development of a piezoelectric sensor installed under the spark plug, which would allow to perceive a variation of the forces acting on the surfaces of the piezoelectric material due to the pressure variations inside the cylinder, generating a measurable voltage signal. The most convenient solution has been developed, with the miniaturization of the sensor as much as possible without compromising its functionality.
The tests carried out with the first prototypes showed a significant correlation with the reference pressure sensor but also showed issues affecting the accuracy of measurement. Such issues are most likely caused by thermic stress both of the assembly and the piezoelectric element, which lead to a non-linear transmission of forces and a variation of piezoelectric properties. For this reason, a new algorithm has been proposed, which is capable of compensating for potential errors in the evaluation of combustion indexes.
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Altobelli, Simone. "Modellistica di accensione per candele ad arco elettrico in motori a combustione interna alternativi." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
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Nel panorama mondiale di contenimento delle emissioni inquinanti in atmosfera é divenuto sempre più importante limitare la parte derivante dai motori a combustione interna: l'utilizzo di motori GDI a carica stratificata e di ricircolo dei
gas di scarico (EGR) sono esempi di tecnologie pensate proprio in tale ottica.
Sia la presenza di un ambiente magro che di EGR nel cilindro, come anche l'aumento della pressione nel cilindro per l'incremento della pressione di sovralimentazione o del rapporto di compressione, hanno lo svantaggio di limitare
la velocità di combustione e rendere più sfavorevoli le condizioni di accensione della miscela; in questo scenario diviene di fondamentale importanza il miglioramento dei
sistemi di accensione, la creazione di modelli volti a simularli e la comprensione dei fenomeni che ne stanno alla base.
Il seguente lavoro di tesi si inserisce proprio in questo contesto, indagando le varie fasi di cui si compone il fenomeno dell'accensione e le relazioni che legano le variabili di interesse fisico, verificate sulla base di evidenze sperimentali.
Successivamente vengono analizzati i principali modelli d'accensione che sono stati proposti e implementati in codici computazionali fluidodinamici; l'analisi mette in luce le
differenze, i punti di forza e le semplificazioni introdotte in ognuno di essi, in modo da poterli valutare criticamente.
La suddetta analisi é anche utile per introdurre il modello frutto del lavoro del gruppo di ricerca dell'Università di Bologna; ci si concentra particolarmente su quest'ultimo poiché un obiettivo di questo lavoro di tesi é stato proprio l'implementazione e l'utilizzo del modello in un codice fluidodinamico tridimensionale quale CONVERGE CFD.
L'implementazione é stata poi validata attraverso simulazioni su una geometria reale di un motore a combustione interna ad elevate prestazioni, confrontando i risultati ottenuti con il nuovo modello rispetto ai dati sperimentali sulla combustione.
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Östling, Johan. "Effekt och Lumen mätning av LED lampor." Thesis, Uppsala universitet, Fasta tillståndets elektronik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-369726.
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I denna rapport undersökts effect förbrukning och uppmätt antal Lumen för en rad olika LED-lampor, reslutatet jämförs sedan med specifikationerna för respektive lampa. Slutsatsen är att även fast det är problematiskt att mäta antalet Lumen från en lampa, så går det att uppvisa liknande resultat som förpackningen påvisar. Effektförbruknings mätningar har mindre felkällor vilket ger ett noggrannare resultat.
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Basadre, Ayulo Jorge. "BARRETO, César Delgado; María Antonieta DELGADO MENÉNDEZ y César Lincoln CANDELA SANCHEZ. Introducción al Derecho Internacional Privado. 2.a edición. Tomo I. Lima: Pontificia Universidad Católica del Perú, 2004." Pontificia Universidad Católica del Perú, 2014. http://repositorio.pucp.edu.pe/index/handle/123456789/115341.
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Guerra, Martinière Margarita. "Lossio, Jorge y Emilio Candela. Prensa, conspiraciones y elecciones: el Perú en el ocaso del régimen oligárquico. Lima: Instituto Riva- Agüero y Pontificia Universidad Católica del Perú, 2015, 155 pp." Pontificia Universidad Católica del Perú, 2016. http://repositorio.pucp.edu.pe/index/handle/123456789/122121.
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Montagna, Marco. "Scala delle distanze in astrofisica." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/12831/.
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La misura delle distanze in astrofisica è una materia complessa ma essenziale per la comprensione dei fenomeni astronomici. Nei secoli gli astronomi hanno ideato diversi metodi per ottenere questa importante misura. Nel loro insieme questi metodi formano una scala delle distanze, dove ogni gradino della scala è calibrato a partire dal gradino precedente. I metodi per misurare le distanze in astrofisica sono raggruppati in tre categorie: i metodi geometrici, basati sul concetto di parallasse, che possono essere usati solo all'interno della Via Lattea; gli indicatori primari, i quali sono basati sul concetto di candele standard, ovvero oggetti di cui si conosce a priori la magnitudine assoluta, utili per determinare distanze fino a 300 Mpc; infine, gli indicatori secondari, calibrati a partire dagli indicatori primari, che sono usati per ottenere le distanze di oggetti fino ai confini dell'Universo conosciuto. In questa tesi di laurea vengono presi in esame i diversi metodi: la parallasse stellare annua, il fit di sequenza principale, le candele standard e in particolare le Cefeidi, le stelle RR Lyrae e le supernovae Ia, il piano fondamentale, la legge di Tully-Fisher, la legge di Hubble. Infine, dopo aver parlato delle galassie più lontane osservate dal telescopio spaziale Hubble, una breve sezione è dedicata a cenni riguardo al problema delle distanze in cosmologia.
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Dornelles, Rodrigo Ciconet. "Ciência, coletas e extrações : uma etnografia a partir de um laboratório de genética de populações." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/76221.
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Esta dissertação é o resultado de um intenso processo de imersão em um dos espaços mais íntimos do fazer científico: o laboratório. O objetivo interposto foi o de realizar uma pesquisa de caráter etnográfico em um laboratório de pesquisa em genética de populações humanas, vinculado ao Instituto de Biociências, ao Departamento de Genética e ao Programa de Pós-Graduação em Genética e Biologia Molecular (PPGBM) da Universidade Federal do Rio Grande do Sul (UFRGS). O objeto deste estudo não foi o laboratório de pesquisa em si, mas as práticas científicas levadas a cabo por este coletivo ao ser fazer do Consórcio para Análise da Diversidade e Evolução na América Latina (CANDELA), um consórcio de pesquisa multi-cêntrico que, como o próprio nome indica, procura dar conta da diversidade étnico-racial em diversos países na América Latina. Buscou-se etnografar o que acontecia, sobretudo, entre instrumentos e práticas laboratoriais, durante a realização deste consórcio de pesquisa, abordando as escolhas práticas e conceituais que foram adotadas no cotidiano científico durante pouco mais de seis meses. Tentou-se não perder de vista as associações mais amplas que foram estabelecidas nesse contexto, de forma que o laboratório foi o ponto de partida e não o ponto de chegada. Nesse sentido, o que se realizou é o que se denomina aqui de “etnografia a partir do laboratório”. No plano teórico-epistemológico, a proposta é a de colocar em questão dicotomias clássicas da ciência moderna, como cultura-natureza, a partir do estudo etnográfico de um projeto de pesquisa que estaria na fronteira entre as ditas ciências naturais e ciências sociais, contribuindo para a ampliação da discussão em torno da agência dos não humanos e de quanto isso se faz central em uma pesquisa de cunho etnográfico que leve a sério não só o que dizem nossos interlocutores humanos, mas também aqueles que emergem a partir da fala destes e da observação da prática científica. Além disso, ao mesmo tempo que esta dissertação procura mostrar a centralidade dos não humanos na prática científica principalmente através de um evento ocorrido ao longo do trabalho de campo, ela aponta para a possibilidade de interlocução entre as ciências biológicas e as ciências sociais.This dissertation is the result of an intense immersion in one of the most intimate spaces of the scientific practice: the laboratory. The goal brought was to conduct an ethnographic research in a laboratory in population genetics, linked to the Instituto de Biociências, of Departamento de Genética and to Programa de Pós-Graduação em Genética e Biologia Molecular (PPGBM) at the Universidade Federal do Rio Grande do Sul (UFRGS). The object of this study was not to research the laboratory itself, but the scientific practices undertaken by this collective as being part of the Consortium for Analysis of Diversity and Evolution in Latin America (CANDELA), a multi-center research consortium, as its name implies, sought to account for the racial-ethnic diversity in several countries in Latin America. It tries to give an account of what happened, especially among instruments and laboratory practice, within this research consortium, tackling the everyday practical and conceptual scientific choices ocurred during the over six months of fieldwork research. It intends to not lose sight of the broader associations that were established in this context, so that the laboratory was the starting point and not the ending point. In this sense, what took place is what is called here an “ethnography from the laboratory”. In a theoretical-epistemological scheme, the proposal is to discuss traditional dichotomies of modern science, such as culture and nature, from ethnographic study of a research project that was on the border between natural sciences and social sciences, contributing to expanding the discussion on the agency of nonhumans and how this is done in an ethnographic research that takes seriously not only what is said by our human counterparts, but also those that emerge from these talks and from the observation of scientific practice. Moreover, while this dissertation seeks to show the centrality of non-human in scientific practice mainly through an event that occurred over the fieldwork, it points to the possibility of dialogue between the natural sciences and the social sciences.
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Vera, Abrilot Romina Elizabeth. "Efecto de la dosis de la siembra sobre el rendimiento y la calidad del trigo candeal (Triticum turgidum L. ssp. Durum) variedad llareta INIA, es condiciones de secano mediterráneo." Tesis, Universidad de Chile, 2011. http://repositorio.uchile.cl/handle/2250/148649.
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Memoria para optar al Título Profesional de Ingeniero Agrónomo Mención FitotecniaEn Chile el trigo candeal (Triticum turgidum L. spp. durum) se ha cultivado tradicionalmente bajo riego, pero desde hace algunas temporadas comenzó a ser desplazado hacia zonas de secano en el centro sur del país. Históricamente los agricultores han sembrado altas dosis de semillas, situación que puede ser contraproducente bajo condiciones de secano mediterráneo llegando a afectar de manera significativa el rendimiento y la calidad de granos. En consecuencia, el objetivo de este trabajo fue evaluar el efecto de cinco dosis de siembra sobre el rendimiento y la calidad de granos producidos bajo secano mediterráneo. En el mes de mayo del año 2009 se sembró trigo candeal, variedad Llareta INIA en cinco dosis de siembra; 30, 60, 90, 120 y 150 kg ha-1, bajo condiciones de secano mediterráneo en la zona central de Chile, donde la precipitación alcanzó aproximadamente los 300 mm durante el período de crecimiento del cultivo. Los resultados mostraron que los tratamientos produjeron diferencias significativas para el número de macollos fértiles por planta y el número de espiguillas por espiga. Sin embargo, los tratamientos no produjeron diferencias significativas sobre el rendimiento, obteniéndose en promedio 33 qq ha-1. La calidad de los granos no tuvo diferencias significativas entre los tratamientos. Sin embargo, dada la sequía terminal experimentada en el ensayo, en todos los tratamientos el peso del hectólitro fue bajo para los requerimientos de la industria, obteniéndose en promedio 77,6 kg hL-1. El contenido de proteína promedio de los granos fue 13%, valor que se bonifica a nivel industrial. Finalmente se puede concluir que es posible reducir los costos de producción reduciendo la dosis de semilla a 100 kg ha-1, sin alterar el rendimiento ni la calidad de los granos de trigo candeal en condiciones de secano mediterráneo.
The cultivation of durum wheat (Triticum turgidum L. spp. durum) in Chile has moved towards to rainfed areas. The selected cultivars and the studied sowing doses in the country has been developed under irrigated cultivar condition, this can be contrary to a management under rainfed mediterranean conditions, where the sowing doses are considered high for rainfed conditions, wich can affect in a significant way the performance. Therefore, the objective of this study was to analyze the effect of sowing doses on mediterranean rainfed areas over the yield and grain quality of the durum wheat. In the year 2009 durum wheat (variety Llareta INIA) was sown in five different sowing doses 30, 60, 90, 120 and 150 kg ha-1, under mediterranean rainfed condition. During the study period rainfall reached at 300 mm. The results showed significant differences in number of tillers per plant and number of spikelets per spikes. However, there was no effect on yields, averaging 33 qq ha-1. Likewise, no difference was observed in hectoliter weight and protein content in grain, reaching average of 77,6 kg hL-1 and 13%, respectively. Finally conclude that it is possible to reduce production cost by reducing the dose of seed to 100 kg ha-1; without affecting the yield and quality of the grains of wheat under Mediterranean rainfed conditions.
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Mehrotra, Pankaj. "Immunological and morphological characterization of Candida albicans and Candida haemulonii." Thesis, University of Aberdeen, 2014. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=210107.
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During the infection process Candida albicans has to respond to various stresses imposed by host environment including oxidative and osmolarity stress generated by phagocytic cells such as macrophages and neutrophils. Exposure to caspofungin and other antifungal antibiotics also imposes stress on the C. albicans cell wall. These various stress responses are orchestrated through the activation of multiple stress pathways including the cAMP-PKA, several MAPK pathways and the Ca2+-calcineurin pathway which influence cell wall shape and composition. Such changes were predicted to influence recognition of C. albicans by innate immune cells. During my Ph.D. studies I primarily investigated the effect of the activation or inhibition of these pathways on the interaction with the innate immune cells by examining phagocytosis, the cytokine profile induced by mononuclear and polynuclear cells of the innate immune system. I found that the activation and inhibition of these pathways plays an important role in remodeling of cell wall and hence the immunological profile. Inactivation of cAMP, Calcium signaling pathway by the deletion of TPK1 and CNA1 resulted in marked reduction in pro-inflammatory cytokine production. Inactivation of MAPK pathway by deletion of HOG1 altered major pro-inflammatory cytokine secretion. Cytokine production was also affected by exposure of C. albicans signaling mutants to Calcofluor White, caspofungin, oxidative and osmotic inducing stresses. Cytokine stimulation was also affected by deletion of URA3, exposure of C. albicans to rifmapicin and antimycin A. These results suggest that stress signaling pathways act to regulate collateral changes in the cell wall, which in turn affects the immune reactivity. Pro and anti-inflammatory cytokine and antifungal profiles of Candida haemulonii was also found to be highly variable. Thus regulation and exposure to different microenvironments significantly modifies immunological signature of fungal cells, suggesting that responses to local stresses make the fungal cell surface a moving target for immunological surveillance.
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Rangel, Ana Lúcia Carrinho Ayroza. "Aderencia de Candida albicans, Candida tropicalis e Candida krusei na superficie da lingua de ratos normais e xerostomicos." [s.n.], 2001. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288395.
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Orientador: Oslei Paes de AlmeidaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
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Resumo: A adesão de microrganismos às superfícies mucosas do hospedeiro é um pré-requisito importante para a colonização e infecção microbiana. Dentre as espécies de Candida, C.albicans é considerada a mais patogênica e com maior capacidade de aderência às células epiteliais, seguida de C.tropicalis. C.krusei é uma espécie pouco patogênica e com baixa capacidade de aderência, causadora de doença principalmente em indivíduos imunocomprometidos. Muitos dos estudos sobre aderência de Candida são realizados in vitro, havendo poucos estudos in vivo. Este trabalho teve como objetivo principal estudar a aderência de C. albicans, C. tropicalis e C. krusei no dorso da língua de ratos. Foram utilizados 270 ratos divididos em 3 grupos de 90 animais, cada grupo recebendo inóculo de uma das três espécies e sendo composto de 45 animais normais e 45 xerostômicos. A recuperação de Candida a partir da saliva foi realizada nos períodos de 5, 15, 30, 60 minutos e 4, 12, 24, 48 e 72 horas após a inoculação. Logo em seguida os animais foram sacrificados e a língua foi retirada para contagem de leveduras aderidas. A quantificação foi feita a partir do volume de saliva coletado e o número de unidades formadoras de colônias (UFC) recuperadas. A contagem foi realizada em 20 campos da região das papilas verdadeiras da língua dos ratos. Os resultados mostraram que a aderência de Candida ocorre principalmente na queratina mole das papilas verdadeiras, sobre a placa bacteriana presente nesta área. A xerostomia aumentou a quantidade de placa bacteriana nas papilas linguais e facilitou a aderência das três espécies de Candida, aumentando também o número de leveduras recuperadas. C.krusei, C.tropicalis e C.albicans apresentaram valores semelhantes tanto na recuperação como na contagem
Abstract: The adhesion of microorganisms to host mucosal surfaces is an important prerequisite for successful microbial colonization and infection. Candida albicans is the most pathogenic of Candida species and has a high ability of adherence to epithelial cells, followed by C.tropicalis. C.krusei is the least pathogenic species, causing candidosis only in immunocompromised host. Candidal adherence is studied mainly in vitro, and there are few in vivo studies. The aim of this study was to determine in vivo C. albicans, C. tropicalis, and C.krusei adhesion to rat tongue. 270 rats were divided in 3 groups of 90 animais, each group having 45 normal and 45 xerostomic rats. Each group received oral innoculation of Candida albicans, Candida tropicalis or Candida krusei suspension and yeasts were recovered from saliva after 5, 15, 30, and 60min, and in 4, 12, 24, 48, and 72h. After saliva recovery the rats were sacrificed and their tongues removed for histological evaluation and yeasts quantification, considering the volume of saliva recovered and the number of colony-forming units (CFU). Histologically, 20 highpower fields of true papillae of the rat tongue were counted and the results showed that the Candida adherence occurred mainly over the bacterial plaque in the "soft keratin" of the papillae. Xerostomia increased the amount of bacterial plaque in the papillae and facilitated the adherence of ali three species, increasing also the number of recovered yeasts. C.krusei, C.tropicalis and C.albicans showed similar values in salivary recovery and histological quantification
Mestrado
Patologia
Mestre em Estomatopatologia
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Ferreira, Maria Aurea Feitosa. "Eficacia de limpadores quimicos a base de peroxidos e hipoclorito na remoção de Candida spp. em rembasadores resilientes." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288157.
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Orientador: Altair Antoninha Del Bel CuryTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
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Resumo: Candida albicans está associada com a etiologia da estomatite protética, patologia que acomete entre 11 a 67% dos usuários de próteses removíveis. Entretanto, mais recentemente, a Candida glabrata tem se destacado por apresentar hidrofobicidade e adesão à superfície de resina acrílica superior à da Candida albicans. Em acréscimo, características de superfície dos materiais como rugosidade (Ra) e energia livre de superfície (ELS) podem contribuir para a adesão de microrganismos. Desse modo, o objetivo desta pesquisa foi avaliar a rugosidade e energia livre de superfície dos rembasadores de próteses à base de poli - metilmetacrilato (Coe Soft e Kooliner) e silicone (Ufi Gel P) antes da contaminação com C. albicans ATCC 90028 e C. glabrata ATCC 2001, bem como verificar a eficácia dos limpadores químicos à base de peróxidos (Polident 3 minutes e Efferdent) e Hipoclorito de sódio a 0,5% na remoção desses microrganismos.Assim, para cada material rembasador foram confeccionadas 64 bases de resina acrílica Onda CryI (25 x 12 x 1mm), preparadas conforme as instruções do fabricante e, reembasadas constituindo dessa forma os corj'i>osde prova. Estes tiveram a rugosidade e energia de superfície determinadas. A seguir, foram separadas aleatoriamente em 2 grupos constituídos de 32 amostras cada, conforme o tipo de Candida. Em seguida, estes foram subdivididos em 4 grupos de 8 de acordo com os tratamentos: G1 - Água destilada (Controle); G2 - Polident ; 3 minutes; G3 - Efferdent; G4 - Hipoclorito de sódio 0,5%. Todas as amostras foram imersas em saliva humana durante'30 minutos para a formação da película adquirida. Posteriormente, foram submetidas ao teste de adesão durante período de 2 horas com uma das candidas, e então submetidos aos tratamentos nos tempos de: G1 - 15 minutos; G2 - 3 minutos; G3 -15 minutos e G4 -10 minutos. A contagem das células remanesce.ntes após o tratamento foi realizada em microscópio de luz (400x). Os dados foram submetidos à análise de variância e teste de Tukey (rugosidade de superfície e aderência fúngica) e ANOVA on Ranks para ELS, com nível de significância de 5%. O rembasador à base de silicone (Ufi Gel P) apresentou os menores valores de rugosidade comparados aos rembasadores à base de poli-imetil metacrilato (Coe 50ft e Kooliner), p<0,05. Entretanto, todos os materiais diferiram entre si para a energia de superfície (p<0,05), sendo que o Coe 50ft e o Ufi Gel P apresentaram os maiores e menores valores, respectivamente. Candida glabrata apresentou o maior número de células remanescentes aderidas, independente do rembasador utilizado (p<0,01). Dentre os limpadores, apenas o hipoclorito de sódio 0,5% diferiu do controle (p=0.001), apresentando um menor número de células remanescentes aderidas. Condui-se que o hipoclorito de sódio a 0,5% foi eficaz na remoção das células aderidas dos rembasadores, independente da espécie de Candida
Abstract: Candida albicans is associated with denture stomatitis etiology, pathology which affect about 11 to 67% of removable prostheses users. However, more recently, the Candida glabrata has been highlighted for presenting superior hydrophobicity and resin acrylic surface adherence when compared to the C. albicans. In addition, surface characteristics' materiais such roughness (Ra) and surface free energy (EL8) may contribute to the microorganisms' adhesion. Thus, the purpose of this study was to evaluate the surface roughness and surface free energy of methyl methacylate liners materiais (Coe 80ft and Kooliner) and silicone (Ufi Gel P) before contamination with C. albicans (ATCC 90028) and C. glabrata (ATCC2001), as well to verify the peroxide chemical denture cleansers efficacy (Polident 3 minutos and Efferdent) and 0.5% sodium hypochlorite - NaOCl, in the miaoorganisms' removing. Thus, 64 rectangular bases measuring 25 x 12 x 1 mm using microwave-polymerized acryli~ resins, following manufacturers' recommendations, to each material were made, then were relined and after surface roughness and surface free energy were measured. Next, the samples were randomly separated by lottery into two groups of 32 each, according to the fungus and these were subdivided into four groups of eight as the treatments: G1 - Distilled water (Control); G2 - Polident 3 min. utes; G3 - Efferdent; G4 - 0,5% NaOCI. Ali the samples rested in human whole saliva for 30 minutes to form an acquired pellicle. After, they were submitted to the adherence assay with one of the fungus for two hours, and then, treated, following these times: G1 - Distilled water (15 minutes); 2 - Polident 3 minutes (3 minutes); 3 - Efferdent (15 minutes); 4 - 0,5% sodium hypochlorite (10 minutes). The adhered cells were counted using a light microscope (Axiostar 2 Plus, Carl Zeiss, Jena, Germany) at 400 x magnification. The data were submitted to the analysis of variance and Tukey test (roughness and fungus adherence) and ANOVA on Ranks for EL8, with significance levei of 5%. The silicone-based liner (Ufi Gel P) showed lower values of roughness compared to the methyl methacrilate-based liners (Coe 80ft and Kooliner), (p<0.05). However, ali these materiais were different among them for surface free energy (p<0.05), where the Coe 80ft and Ufi Gel P showed the highest and lowest values, respectively. Candida glabrata showed the highest number of adhered cells for ali materiais (p<0.01). Among evaluated cleansers, only 0.5% sodium hypochlorite differed from the control (p=0.001), showing the lowest number of remaining cells adhered. The conclusion is that the 0.5% sodium hypochlorite was the only one chemical cleanser efficient in the adhered cells removing in ali denture liners independent of the Candida specie
Doutorado
Protese Dental
Doutor em Clínica Odontológica
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Vieira, Ana Paula Coelho. "Eficácia de limpadores químicos na remoção e re-colonização de biofilmes de Candida spp. formados na superfície de material reembasador." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288379.
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Orientadores: Altair Antoninha Del Bel Cury, Wander José da SilvaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
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Resumo: Os reembasadores para base de prótese, após a exposição à cavidade bucal, apresentam alterações de superfície facilitando a adesão e a colonização por micro-organismos. Para a limpeza de superfície desses materiais são indicados os limpadores químicos para evitar os danos mecânicos que podem ser provocados pelas cerdas das escovas dentais. Assim, o objetivo nesta pesquisa foi avaliar a eficácia de limpadores químicos na remoção de biofilme de Candida spp. desenvolvido sobre a superfície de um reembasador classificado como permanente à base de poli-metilmetacrilato e na prevenção da re-colonização dessa superfície, especialmente a Candida spp., comumente associada ao desenvolvimento da candidíase. Espécimes (10 mm diâmetro X 3 mm altura) de resina acrílica reembasada com um reembasador mais representativo disponível comercialmente teve sua rugosidade de superfície mensurada antes (baseline) e biofilme de C. albicans ATCC 90028 ou C. glabrata ATCC 2001 foi desenvolvido sobre os mesmos. Após a formação dos biofilmes os espécimes foram aleatorizados e submetidos aos tratamentos (n=16): AD - Água destilada (Controle), 15 min; POL - Polident 3 minutos, 3 min; EFF - Efferdent, 15 min; HPS - Hipoclorito de sódio a 0,5%, 10 minutos. Metade destes espécimes (n=8) foi utilizada para determinação da eficácia dos limpadores, utilizando contagem de células viáveis, enquanto os espécimes remanescentes (n=8), após os tratamentos, foram novamente colocados em meio de cultura estéril e incubados por mais 48 h a fim de determinar o efeito dos limpadores na prevenção da recolonização. Após os tratamentos os espécimes tiveram a rugosidade de superfície determinada, considerada pós-tratamento. Alguns espécimes de cada uma das espécies de Candida tiveram a superfície analisada após os tratamentos, por microscopia eletrônica de varredura (MEV). Os dados foram submetidos à análise de variância e teste de Tukey HSD em nível de significância de 5%. A rugosidade de superfície foi significantemente maior após os tratamentos (P<0,05). Quantos aos tratamentos, o HPS mostrou-se efetivo tanto para a desinfecção quanto na recolonização de ambas as espécies de Candida, pois houve ausência total de crescimento. Na avaliação da desinfecção, imediatamente após os tratamentos, quando C. albicans foi considerada, não houve diferença significativa entre os peróxidos alcalinos (p>0,05) e ambos diminuíram o número de células fúngicas (p<0,05) comparado ao tratamento com AD. Entretanto, para C. glabrata, os tratamentos com ADD e peróxidos alcalinos não se diferenciaram entre si (p>0,05). Na análise dos resultados para a recolonização foi observada que houve inversão no comportamento, pois enquanto, para C. albicans, os tratamentos com AD e peróxidos alcalinos não diferiram entre si (p>0,05), para C. glabrata os tratamentos com peróxidos alcalinos apresentaram valores similares e menores (p>0,05),quando comparados com o tratamento com AD (p<0,05). Na comparação entre as espécies de Candida observou-se que C. glabrata apresentou os maiores níveis de células viáveis quando os dados foram avaliados na situação de imediatamente após os tratamentos com os peróxidos alcalinos e foi diferente de C albicans (p<0,05). Entretanto não houve diferença para a recolonização (p>0,05). Os resultados sugerem que os limpadores a base de peróxidos alcalinos não foram efetivos na remoção total dos micro-organismos e também não impediram a recolonização por Candida spp
Abstract: The denture liners exhibits surface changes in oral environment by constant loss of its constituent elements, which facilitate microorganisms adherence that leads to biofilm formation. Denture liners surface can be cleaned by brushing or using denture cleaners, which are recommended, in order to avoid mechanic injuries to denture liners by brushing it. Therefore, the aim of this study was to evaluate the long term efficacy of denture cleansers on Candida spp. biofilm recolonization on liner surface. Specimens of poly (methylmethacrilate) were lined according to manufacturer instructions (10 mm diameter X 3.0 mm thickness). Surface roughness was measured at baseline and after the treatments. Next, biofilms of C. albicans ATCC 90028 and C. glabrata ATCC 2001 were allowed to develop on liner surface for 48 h. Subsequently, the specimens were randomly assigned for the cleaning treatments (n=16): distilled water (DW - control), 15 min; Polident 3 minutes (POL) - 3min; Efferdent (EFF)-15 min; sodium hypochlorite (HYP) - 10 min. After the treatments, specimens (n=8) were sonicated for biofilm disruption and the viable cells were counted (cell/mL). To determine the long term effectiveness of the cleaning process, a set of cleaned specimens (n=8) were submitted to new biofilm growth conditions. After 48 h, biofilm were disrupted by sonication and cell number estimated. Scanning electron microscopy was performed to analyze the specimen topography after denture cleanser treatment. Data were analyzed by ANOVA and Tukey's HSD test was used as post-ANOVA employing a significance level fixed at 5%. The liner surface was rougher after the treatments (P<0.05). Results showed significant differences in cleanliness among the treatments (p<0.05), however for Candida species (p<0.05) no significant difference was observed in the recolonization condition (p>0.05). Alkaline denture cleansers showed similar cleaning performance and both showed lower cells counts compared with the control (p<0.05). Hypochlorite was the only effective treatment as no viable cells were detected even after the recolonization test. Within the limits of this study, it can be concluded that alkaline denture cleansers were not effective on biofilm removal, once denture liner surface by Candida spp biofilm recolonization was not prevented
Mestrado
Protese Dental
Mestre em Clínica Odontológica
20
Gomes, Priscila Nogueira. "Bioatividade, bioestrutura e morfologia de biofilmes de Candida spp. desenvolvidos na presença de fluconazol." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288079.
Full textAbstract:
Orientador: Altair Antoninha Del Bel CuryTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
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Resumo: O biofilme de Candida spp. formado na superfície de próteses removíveis, é o principal fator etiológico da candidose, sendo a C. albicans e a C. glabrata as espécies mais prevalentes nesta condição. O antifúngico fluconazol (FLZ) é frequentemente utilizado no tratamento da candidose, porém o sucesso tem sido limitado devido a resistência desenvolvida pela Candida a esse medicamento. Considerando a importância da estrutura e morfologia do biofilme de Candida na candidose, o objetivo neste estudo foi avaliar o efeito de FLZ na bioatividade, bioestrutura e morfologia celular de biofilmes de Candida spp. desenvolvidos na presença deste antifúngico. Espécimes (10 mm x 2 mm) foram confeccionados utilizando resina de poli(metilmetacrilato) (PMMA), polimerizada por banho de água quente. Películas de saliva foram formadas na superfície da PMMA, e biofilmes de um isolado referência e dois isolados clínicos de C. albicans (ATCC 90028, P01, P34) e C. glabrata (ATCC 2001, P11, P31) foram desenvolvidos por 48h. Dois grupos foram formados: controle e experimental. FLZ a 2,56 µg/mL, concentração biodisponivel na saliva, foi adicionado ao meio de cultura do grupo experimental. Os meios de cultura do grupo controle e experimental foram trocados a cada 24 h. As bioatividades dos biofilmes foram avaliadas utilizando análise colorimétrica de redução por XTT. A bioestrutura analisada através do Microscópio Confocal à Laser e a morfologia celular avaliada utilizando o Microscópio Eletrônico de Transmissão. Os dados foram analisados pelo Test t de Student com nível de significância de 5%. A presença do FLZ reduziu a bioatividade de todos os biofilmes de C. albicans (p<0.001), porém não alterou a estrutura e morfologia da C. albicans P34. Quanto à bioatividade e bioestrutura dos biofilmes de C. glabrata, não foram encontradas diferenças estatisticamente significantes entre os grupos controle e experimental. Pode-se concluir que as alterações da bioatividade, bioestrutura e morfologia celular, como resposta ao tratamento com FLZ, na concentração biodisponível na saliva, depende da cepa de Candida spp. avaliada.
Abstract: Candida spp. biofilm formed on removable denture surfaces is considered the main etiologic factor of candidosis, being the C. albicans and C.glabrata the species most frequently found in this condition. The antifungic fluconazol (FLZ) is commonly used in the treatment of candidosis, however its success is limited due to the resistance developed by Candida to this medicament. Considering the importance of the structure and morphology of Candida biofilms in the candidosis, the aim of this study was to evaluate the effect of FLZ on the bioactivity, biostructure and morphology of Candida spp. biofilms formed in the presence of this antifungal agent. Specimens (10 mm x 2 mm) were fabricated using water bath poly(methylmethacrylate) resin (PMMA). Salivary pellicles were formed on the PMMA surface, and biofilms of a reference strain and two clinical isolates of C. albicans (ATCC 90028, P01, P34) and C. glabrata (ATCC 2001, P11, P31) were developed for a period of 48h. Two groups were formed: control and experimental. FLZ at 2.56 µg/mL, concentration bioavailable in saliva, was added to the medium of the experimental group. The culture mediums of the control and experimental groups were changed at 24 hours. The bioactivities of the biofilms were evaluated with XTT reduction colorimetric assay. The biostructure was analyzed by the Confocal Scanning Laser Microscopy and the cell morphology analyzed by the Transmission Electron Microscopy. The data were analyzed by Student's t-test, with significance level set at 5%. The presence of FLZ decreased the bioactivity of all C. albicans biofilms (p<0.001), it did not change the structure and morphology of P34. As regards C. glabrata biofilms bioactivity and biostructure, no statistically significant differences were found between control and experimental groups for biofilms of all strains. It could be concluded that the alterations in bioactivity, biostructure and cell morphology in response to the treatment with fluconazole, bioavailable concentration present in saliva, depends on the Candida spp. strain
Doutorado
Protese Dental
Doutor em Clínica Odontológica
21
Івахнюк, Тетяна Василівна, Татьяна Васильевна Ивахнюк, Tetiana Vasylivna Ivakhniuk, Юрій Петрович Івахнюк, Юрий Петрович Ивахнюк, Yurii Petrovych Ivakhniuk, Микола Микитович Каплін, Николай Никитович Каплин, and Mykola Mykytovych Kaplin. "Фагоцитарна активність лейкоцитів донорів у відношенні різних штамів Candida spp., виділених від новонароджених та з об`єктів зовнішнього середовища." Thesis, Видавництво СумДУ, 2010. http://essuir.sumdu.edu.ua/handle/123456789/5127.
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Каплін, Микола Микитович, Николай Никитович Каплин, Mykola Mykytovych Kaplin, Тетяна Василівна Івахнюк, Татьяна Васильевна Ивахнюк, Tetiana Vasylivna Ivakhniuk, and К. С. Сиромятнікова. "Антагоністичний вплив лактобацил на Candida spp. в експерименті in vitro." Thesis, Видавництво СумДУ, 2010. http://essuir.sumdu.edu.ua/handle/123456789/5093.
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Foubard, Sylvie. "Pouvoir pathogène des champignons du genre "Candida" à l'exclusion de "Candida albicans"." Paris 5, 1988. http://www.theses.fr/1988PA05P211.
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Riaublanc, Alain. "Etude et essais d'utilisation des lipases de candida rugosa et candida parapsilosis." Montpellier, ENSA, 1991. http://www.theses.fr/1991ENSA0005.
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Deux souches de levure lipolytique, candida parapsilosis et candida rugosa ont ete etudiees. Les enzymes lipolytiques des deux souches ont ete purifiees et caracterisees. L'activite des deux lipases sur differents esters a ete testee. Les possibilites de synthese d'esters en utilisant la lipase de candida parapsilosis en milieu aqueux ont ete testees. La production de biomasse par la souche de candida rugosa en culture continue et semi-continue, en presence d'huile de palme brute, a ete optimisee
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Sousa, Diana Sofia Ortiga de. "Mistranslation in Candida albicans." Master's thesis, Universidade de Aveiro, 2011. http://hdl.handle.net/10773/8156.
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Mestrado em Biologia AplicadaThe genetic code establishes the rules that determine the transfer of genetic information from nucleic acids to proteins. The importance of the genetic code in genome decoding and its high conservation suggests that its evolution is highly restricted or even frozen. Despite this, various prokaryotic and eukaryotic genetic code alterations have been found, showing that the code is surprisingly flexible. For instance, the human pathogen Candida albicans contains an ambiguous tRNACAG that decodes a CUG codon as Ser (97%) and as Leu (3%). To further study ambiguity in other amino acid codons, we have engineered 8 mutant tRNASer that misincorporate Ser at 8 different codons belonging to distinct amino acids families (Glu, Arg, Asn, Cys, Phe, Gln, His and Pro) in Candida albicans. The wild-type tRNA was subjected to site-directed mutagenesis in order to change its anticodon to CUC, CCU, GUU, GCA, GAA, CUG, GUG and GGG. The tRNA stability, the cellular changes and the stress response of the resulting mistranslating strains were evaluated through northern blot analysis, cell transformation efficiency, growth rate and expression of a HSP104-GFP reporter system. A phenotypic screening probing various environmental stress conditions was performed in order to further characterize these strains. Experimental data suggest that these genetic code ambiguities affect fitness negatively in standard growth conditions and introduce growth advantages in presence of stress conditions. Thus, stress response triggered by codon ambiguity increase adaptation potential.
O código genético estabelece regras que determinam a transferência de informação genética a partir dos ácidos nucleicos para proteínas. A importância do código genético na descodificação do genoma e sua alta conservação sugere que a sua evolução é altamente restrita. Apesar disso, várias alterações no código genético dos procariotas e eucariotas têm sido encontradas, mostrando que o código é surpreendentemente flexível. Por exemplo, o patogénico humano Candida albicans contém um tRNACAG ambíguo que descodifica o codão CUG como Ser (97%) e como Leu (3%). Para continuar o estudo da ambiguidade noutros codões, induzimos 8 tRNASer mutantes, que incorporam incorretamente o aminoácido serina a 8 codões diferentes, pertencentes a distintas famílias de aminoácidos (Glu, Arg, Asn, Cys, Phe, Gln, His e Pro), em Candida albicans. O tRNA não mutado foi submetido a mutagénese dirigida, a fim de modificar o seu anticodão UGA para CUC, CCU, GUU, GCA, GAA, CUG, GUG e GGG. A estabilidade do tRNA, as alterações celulares e resposta ao stress das estirpes mutantes resultantes foram avaliadas através da análise de Northern blot, da eficiência de transformação das células, da taxa de crescimento e da expressão do sistema repórter HSP104-GFP. Além disso, a caracterização fenotípica em determinadas condições de stress foi realizada com o intuito de caracterizar melhor essas estirpes. Os dados experimentais sugerem que essas ambiguidades ao código genético afetam negativamente a aptidão das células em condições de crescimento normais e introduzem vantagens no crescimento na presença de condições de stress. Assim, a resposta ao stress provocada pela ambiguidade dos codões pode aumentar o potencial de adaptação.
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Cardoso, Michelle [UNESP]. "Microespectroscopia infravermelha por transformada de fourier: identificação e discriminação de cepas clínicas de Candida albicans e Candida glabrata." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/95850.
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A técnica da espectroscopia infravermelha por transformada de Fourier (FT-IR) vem sendo largamente empregada como uma abordagem rápida e simples para a identificação de microrganismos, incluindo a do gênero Candida. A proposta deste estudo foi avaliar o emprego da microespectroscopia FT-IR na identificação e discriminação de 5 cepas clínicas de Candida albicans e 3 de Candida glabrata, as quais foram identificadas previamente por meio de métodos convencionais, e mais duas cepas ATCC de cada espécie. As amostras foram analisadas em triplicata, a partir de culturas independentes, por meio de filmes finos obtidos da suspensão em solução salina estéril a 0,85% da biomassa da colônia que ficou incubada por 24 horas em placas com ágar Saboraud Dextrose. Dez espectros com 32 varreduras foram obtidos na forma de ponto em 10 regiões selecionadas aleatoriamente nas amostras. A média foi obtida dos dez espectros de cada amostra para a análise estatística multivariada, dada pela análise de cluster. Além disso os espectros foram transformados em primeira derivada e três janelas espectrais foram determinadas (900-1250 cm-1, 1300-1600 cm-1, 2800-3000 cm-1). A representação dos resultados foi dada pela construção de um dendograma. Nesse, foi possível separar em dois grupos distintos as duas espécies de Candida estudadas. Dessa forma, pode-se concluir que a microespectroscopia FT-IR foi capaz de identificar e discriminar cepas clínicas de Candida albicans e de Candida glabrata, sendo um método promissor para identificação de leveduras
The technique of infrared spectroscopy Fourier transform (FT-IR) has been widely used as a new approach for rapid identification and simple micro-organisms, including the genus Candida. The purpose of this study was to evaluate the use of FT-IR microspectroscopy for the identification and discrimination of 5 clinical strains of Candida albicans and Candida glabrata 3, which were previously identified by conventional methods, and two-standard strains of each species. The samples were analyzed in triplicate from independent cultures by means of thin films obtained from a suspension in sterile saline and 0.85% of the biomass of the colony that was incubated for 24 hours in Sabouraud dextrose agar plates. Ten spectra with 32 scans were obtained in 10 randomly selected regions in the samples.The average of ten spectra was obtained from each sample for the multivariate analysis, given by cluster analysis. In addition, three windows were determined spectral (900-1250 cm-1, 1300-1600 cm-1, 2800-3000 cm-1) and the spectra were transformed into first derivative. The representation of the results was given by the construction of a dendrogram. In this, we separated into two groups of two Candida species studied. Thus, one can conclude that the FT-IR microspectroscopy was able to identify and distinguish clinical isolates of Candida albicans and Candida glabrata is an important method for identification of yeasts
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Scherma, Alexandre Prado. "Presença de candida spp. Na cavidade bucal de lactentes durante os primeiros quatro meses d vida /." São José dos Campos, 2002. http://hdl.handle.net/11449/154666.
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Orientador: Rosilene Fernandes da RochaBanca: Maria Stella Amorim da Costa Zollner
Banca: Antonio Olavo Cardoso Jorge
Resumo: A Candidose bucal e um dos processos infecciosos micóticos mais comuns da cavidade oral e existe suscetibilidade aumentada para o mesmo durante o período neonatal principalmente devido à imaturidade dos mecanismos de defesa e a falta de uma microbiota bucal balanceada. Para verificar a presença de Candida spp. na cavidade bucal de lactentes foram examinados inicialmente cem bebês, nos quais foi feita coleta de material do dorso da língua com swab nas primeiras 24 horas de vida. Trinta e três recém-nascidos deste grupo foram acompanhados durante os primeiros quatro meses de vida sendo realizada mensalmente coleta de material da cavidade oral e avaliação das condições gerais de saúde, nutrição e higiene. A análise do material obtido nesse período mostrou positividade para Candida spp. em 64 (48,5%) das 132 amostras. A doença foi observada em 27,3% dos recém nascidos acompanhados. Candida albicans foi a espécie encontrada mais frequentemente (44,6%), e esteve presente em nove dos 11 casos de candidose bucal. Verificou-se com a ananmese que os possíveis fatores de risco para o grupo estudado foram o uso de chupeta e mamadeira, e, a introdução de outros tipos de alimento. Conclui-se que Candida albicans e a espécie prevalente nesta faixa etária
Abstract: Abstract: Oral candidosis is one of the most frequent mycotic infectious diseases of the oral cavity and there is increased susceptibility to this infection during the neonatal period due to immaturity of the defense mechanisms and the lack of a balanced buccal microbiota. To verify the presence of Candida spp. in the oral cavity of infants were examined initially a hundred babies from which were collected material of the lingual dorsum with swabs in the first 24 hours of life. Thirty-three newborn of this group were accompanied during the first 120 days of life and were submitted monthly to a material collection of the oral cavity and an evaluation of general conditions of health, nutrition and hygiene. The analysis of the material collected during this period showed positivity to Candida ssp. in 64 (48,5%) of the 132 samples. Disease was observed in 27,3% of those 33 newborns. Candida albicans was the most frequent species (44,6%) and it was present in nine of the 11 cases of oral candidosis. The anamnesis showed that the possible risk factors were pacifier use, bottle feeding and introduction of different food types. It was concluded that Candida albicans is the prevalent species in this age band
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Tonon, Caroline Coradi. "Terpinen-4-ol : estudo do efeito sinérgico/aditivo, adesão em co-cultura e alteração dos fatores de virulência sobre Candida spp /." Araraquara, 2016. http://hdl.handle.net/11449/138864.
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Orientador: Denise Madalena Palomari SpolidorioBanca: Cristiane Duque
Banca: Janaina de Cássia Orlandi Sardi
Resumo: O gênero Candida pode ser encontrado em até 50% dos indivíduos saudáveis não causando danos aparentes, porém, sob condições predisponentes como doenças sistêmicas ou condições fisiológicas, pode tornar-se patogênico causando inflamação e destruição tecidual. Candida spp. na forma de biofilmes são importantes no desenvolvimento de infecções, pois estão associados a altos níveis de resistência a agentes antimicrobianos. Terapias alternativas com extratos naturais abrem novas perspectivas para prevenção e controle das doenças bucais na busca de efeitos terapêuticos favoráveis. O Terpinen-4-ol é um monoterpeno que atua na indução da perda da membrana e apresenta amplo espectro de atividade antimicrobiana e atividade anti-inflamatória. O objetivo deste estudo foi avaliar o efeito antifúngico, sinérgico/aditivo, inibição da adesão em células orais e alteração dos fatores de virulência do Terpinen-4-ol sobre Candida albicans e Candida tropicalis. Assim, foi realizada a identificação da Concentração Inibitória Mínima (CIM) e Concentração Fungicida Mínima (CFM) do Terpinen-4-ol sobre cepas padrão de C. albicans (ATCC 90028) e C. tropicalis (ATCC4563), empregando-se o método de microdiluição em caldo. Biofilmes mono e dual-espécies foram preparados usando o modelo de placa de microtitulação estática e quantificados por unidades formadoras de colônias (UFC/mL). O efeito do Terpinen-4-ol na adesão de C.albicans e C. tropicalis foi realizado em co-cultura com células orais NOK Si como tam... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The genus Candida can be found in up to 50% of healthy individuals without causing apparent damage, however, under predisposing conditions such as systemic diseases or physiological conditions, can become pathogenic causing inflammation and tissue destruction. Candida spp. in the form of biofilms are important in the development of infections because they are associated with high levels of resistance to antimicrobial agents. Alternative therapies with natural extracts open new perspectives for prevention and control of oral diseases in search of favorable therapeutic effects. The Terpinen-4-ol is a monoterpene engaged in membrane loss of induction and presents broad spectrum of antimicrobial and anti-inflammatory activity. The aim of this study was to evaluate the antifungal effect, synergistic / additive inhibition of adhesion on oral cells and modification of virulence factors of Terpinen-4-ol of Candida albicans and Candida tropicalis. Thus, the identification of Minimum Inhibitory Concentration was performed (MIC) and Minimum Fungicidal Concentration (MFC) of Terpinen-4-ol on standard strains C. albicans (ATCC 90028) and C. tropicalis (ATCC4563), using the method microdilution broth. Biofilms mono and dual-species were prepared using the microtiter plate static model and quantitated by colony forming units (CFU / mL). The effect of Terpinen-4-ol in the adhesion on C. tropicalis and C. albicans was carried out in co-culture with oral cells NOK Si as well as virulence facto... (Complete abstract click electronic access below)
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Bockmühl, Dirk Paul Helmut. "Regulation der Morphogenese des humanpathogenen Pilzes Candida albicans durch Komponenten eines cAMP-abhängigen Signalweges." [S.l. : s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=96232227X.
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Uchoa, Fabio Raddi. "Cidade e deambulação nos filmes de Ozualdo Candeias." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/27/27153/tde-19052009-164733/.
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Este trabalho tem por objeto os filmes de Ozualdo Candeias nos quais São Paulo é representada. Em tais obras foi averiguada a presença de uma cidade, cuja reconstrução em termos de imagens em movimento, é pautada pelo constante deslocamento dos personagens. Tendo por objetivo a descrição do grupo de fitas, constituinte do corpus de pesquisa, o foco de abordagem encontra-se ligado aos diferentes elementos que gravitam em torno da idéia de deambulação. Para tanto, contribui um capítulo inicial, a respeito da apreensão dos corpos e espaços, nas fotografias feitas pelo cineasta na Boca do Lixo. Nos capítulos seguintes são examinados os filmes Ensino Industrial (1962), Rodovias (1962), A margem (1967), Zezero (1973), O Candinho (1976), Aopção ou As rosas da estrada (1981) e As belas da Billings (1987).This dissertation has by finality the study of the films of Ozualdo Candeias in which Sao Paulo is represented. In such films, the presence of une city is being verified, whose reconstruction in terms of cinematographic images is typified by the constant movement of the characters. The aim of this work is the description of the group of films, through the corpus of this research, the focus of the approaching is connected with different elements that turn around of the idea of deambulation. For that, one chapter contributed with the representation of the bodies and spaces, in the photographys made by the director in the Boca do Lixo. In the next chapters the following films are examinated: Ensino Industrial (1962), Rodovias (1962), A margem (1967), Zezero (1973), O Candinho (1976), Aopção ou As rosas da estrada (1981) e As belas da Billings (1987).
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Zallow, Corey E. "A Candle Wizard." Youngstown State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1596390687411324.
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ROBERTO, Ana Emília de Medeiros. "Detecção de resistência as Equinocandinas de Isolados Clínicos de Candida parapsilosis stricto sensu, Candida orthopsilosis e Candida metapsilosis através de Espectrometria de massas." Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/25070.
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ROBERTO, Ana Emília de Medeiros, também é conhecida em citações bibliográficas por: MEDEIROS, A. E. R.Submitted by Pedro Barros (pedro.silvabarros@ufpe.br) on 2018-07-11T20:48:52Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Ana Emília de Medeiros Roberto.pdf: 2427887 bytes, checksum: 98fa3502db60df7b1feef1a3e2887aa1 (MD5)
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CAPES
Observa-se um contínuo aumento na resistência de espécies de Candida aos antifúngicos disponíveis. Faz-se necessário que o diagnóstico seja oportuno e verossímil, associado à indicação terapêutica que é corretamente direcionada a partir de testes de sensibilidade antifúngica in vitro. A utilização da espectrometria de massas através da técnica de Matrix Assisted Laser Desorption/Ionisation Time-Of-Flight Mass Spectrometry (MALDI-TOF MS) que reduz o tempo de diagnóstico em comparação com métodos de rotina já é uma realidade, contudo estudos apontam a capacidade dessa metodologia em identificar cepas resistentes pela detecção de mudanças mínimas no perfil proteíco da cepa após exposição ao fármaco. Assim, objetivou-se diagnosticar, em pacientes internados em UTI, isolados clínicos do complexo Candida parapsilosis lato sensu (Candida parapsilosis stricto sensu, Candida orthopsilosis e Candida metapsilosis) através da técnica proteômica Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) e correlacionar sua sensibilidade/resistência às equinocandinas com mudanças no espectro protéico. Trata-se de uma pesquisa experimental analítica com abordagem qualitativa. Amostras sanguíneas venosas foram coletadas entre agosto de 2014 e julho de 2015, a partir de pacientes internados em UTI, foram observadas ao exame direto e colhidas em frascos de hemocultura. As leveduras isoladas foram identificadas por MALDI-TOF MS e testes de sensibilidade antifúngica foram realizados através do CLSI frente a anidulafungina, caspofungina e micafungina. A detecção na resistência através da mudança mínima do plano espectral protéico obtida no MALDI-TOF MS, foi possível após o cruzamento de cada concentração do espectro com uma das duas concentrações extremas, máxima ou nula, onde formou-se uma matriz a partir do Índice de Correlação do Composto (ICC) utilizado para gerar mapas de calor. Foram diagnosticados 44 casos de candidemia, sendo 26 por Candida parapsilosis, dez C. albicans, dois casos por C. metapsilosis, dois C. orthopsilosis, dois por C. tropicalis, um C. haemulonii e um Candida sp. Vinte e oito (93,2%) isolados do complexo Candida parapsilosis foram sensíveis as equinocandinas de acordo com CLSI e 24 (79,9%) foram sensíveis de acordo com MALDI-TOF. A Concentração Inibitória Mínima e a Mudança Mínima no Perfil Protéico obtidos através do CLSI e MALDI-TOF, apresentaram concordância de 91,6%, 96,6% e 98,3% para anidulafungina, caspofungina e micafungina, respectivamente, frente os isolados de Candida parapsilosis. MALDI-TOF MS é capaz de determinar o breakpoint de uma levedura clínica após 15 horas de exposição ao antifúngico e permite predizer a melhor escolha antifúngica para pacientes críticos com candidemia.
Recently, there is an increase in resistance of Candida species to antifungal drugs available. It is necessary that the diagnosis is timely and credible associated with therapeutic indication that is directed from in vitro antifungal susceptibility testing. The use of mass spectrometry through the technique of Matrix Assisted Laser Desorption / Ionisation Time-Of-Flight Mass Spectrometry (MALDI-TOF MS), which reduces the time of diagnosis as compared to routine methods is already a reality, however pointed studies this methodology can identify resistant strains by detecting minimal changes in protein profile of strain after exposure. Thus, the objective was to diagnose in ICU patients, clinical isolates of complex Candida parapsilosis lato sensu (Candida parapsilosis stricto sensu, Candida orthopsilosis and Candida metapsilosis) through proteomic technique Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) and correlate their sensitivity/resistance to echinocandins with changes in the protein spectrum. It is an analytical experimental research with qualitative approach. Venous blood samples were collected between August 2014 and July 2015, from ICU patients were observed in the direct examination and harvested in blood culture bottles. The yeasts were identified by MALDI-TOF MS and sensitivity tests were performed using CLSI antifungal and MALDI-TOF MS, compared to anidulafungin, caspofungin and micafungin. After crossing every spectrum concentration with one of the two extreme concentrations, maximum or zero, formed the matrix of Compound Correlation Index (ICC) used to generate heat maps. 44 cases of candidemia were diagnosed, 26 by Candida parapsilosis ten C. albicans, two cases of C. metapsilosis two C. orthopsilosis two by C. tropicalis, a C. haemulonii and one case of Candida sp. Twenty-eight (93.2%) isolates of Candida parapsilosis complex echinocandins according to CLSI and 24 were sensitive (79.9%) were sensitive according to MALDI-TOF. The Minimum Inhibitory Concentration and Minimum Change in Protein Profile obtained by CLSI and MALDI-TOF showed concordance of 91.6%, 96.6% and 98.3% for anidulafungin, caspofungin and micafungin, respectively, compared isolates Candida parapsilosis. MALDI-TOF MS is able to determine the breakpoint of a clinical yeast after 15 hours of exposure to antifungal and allows predicting the best antifungal choice for critically ill patients with candidemia
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Beckford, Lucy Mary. "Resitance in Candida albicans and Candida glabrata to inhibitors of #beta#-(1,3)-glucan synthesis." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283930.
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Mixão, Verónica de Pinho 1991. "Hybridization in Candida yeast pathogens." Doctoral thesis, Universitat Pompeu Fabra, 2020. http://hdl.handle.net/10803/670103.
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Candida species are among the most important fungal pathogens. Although Candida albicans is the most common cause of Candida infections, many other Candida species have emerged as pathogens. How pathogenicity is evolutionary acquired is unknown, but previous studies point to a role of hybridization in its development. This thesis studied the genomic features of Candida pathogens, with a special focus on hybrids and their evolution. Specifically, it asked the questions of how spread are hybrids among Candida species, and what are the processes that drive the evolution of their genomes. To this end, genomes from 141 isolates belonging to 13 Candida species were analyzed and compared, to reconstruct their features and evolution. Overall, this thesis supports an important role of hybridization in the emergence of new yeast pathogens and provides novel insights on the evolutionary aftermath of hybridization.Candida spp. se encuentran entre los hongos patógenos más importantes. Candida albicans es la principal causante de infecciones por Candida, pero muchas otras especies del mismo género han emergido como patógenos. Los mecanismos evolutivos implicados en la adquisición de patogenicidad se desconocen, pero estudios precedentes apuntan a que la hibridación puede haber jugado un papel importante en este desarrollo. Esta tesis estudia las características genómicas de las especies patógenas del género Candida, centrándose en híbridos y su evolución. Específicamente, se analiza la presencia de híbridos entre las especies de Candida y se estudian los procesos que impulsan la evolución de sus genomas. Para ello, se analizaron y compararon los genomas de 141 cepas correspondientes a 13 especies con el propósito de reconstruir sus características genómicas y estudiar su evolución. En resumen, esta tesis respalda un papel importante de la hibridación en la aparición de nuevas levaduras patógenas y aporta nuevas ideas sobre las consecuencias evolutivas de dicha hibridación.
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Martchenko, Mikhail. "Postgenomic studies of Candida albicans." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103029.
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We assembled the genome of the human fungal pathogen Candida albicans into eight chromosomes, and annotated each of its genes. A genome comparison with Saccharomyces cerevisiae revealed an increased number of C. albicans superoxide dismutase genes. We analyzed the expression patterns and the function of one of these genes, SOD5, whose role is to protect the pathogen against extracellularly produced, neutrophil-generated superoxide radicals. Comparative genomics also showed that although many of the C. albicans transcription factors, such as Gal4p and Gcn4p, have homologues in S. cerevisiae, the sequence similarities occur only in the DNA binding motifs of those proteins. Deletion analysis of CaGcn4 and CaGal4 proteins show that the N' and C' termini respectively are needed for their transactivation ability. These two transactivation regions show no sequence similarity to the equivalent domains in their S. cerevisiae homologues, and the two C. albicans transactivatiog domains themselves show little similarity. A comparative analysis of the transcriptional machinery between C. albicans and S. cerevisiae showed low sequence similarity of the mediator complex that bridges activation domains of transcription factors to the RNA polymerase II complex. We performed a comparison of intergenic DNA regions to identify the cis-regulatory elements from Candida and Saccharomyces species to examine the organization of the transcriptional regulatory networks between these two organisms. We observed that the C. albicans GAL genes lack Gal4p binding sites, but that such sites are found upstream of telomeric genes and genes involved in glycolysis, and we show that CaGal4p regulates the expression of those genes. We identified the regulatory DNA sequences in the promoters of GAL genes, including a GAL-specific palindrome necessary for GAL10˛ expression. Cph1p, the C. albicans homolog of the Ste12p transcription factor controlling pheromone-induced gene expression in yeast, acts through this GAL-specific palindrome, functioning as an activator in the presence of galactose. This shows C. albicans and S. cerevisiae can regulate the same process by different regulatory circuits.
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O'Donnell, Raymond William. "Chitinolytic enzymes of Candida albicans." Thesis, University of Aberdeen, 1991. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=158392.
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It has been envisaged that lytic enzymes may be crucial in determining the morphology and growth of fungi, and may therefore represent a target for antifungal agents. The chitinolytic system of Candida albicans was investigated using a range of 4-methylumbelliferyl glycosides as model substrates, and its potential as a target for antibiotics has been assessed. Maximum hydrolysis was obtained with substrates having monomer and tetramer chain lengths, being attributed to N-acetylglucosaminidase and endochitinase respectively. Activities were investigated in cell fractions, vacuoles, and also in whole cell preparations. The characteristics of both chitinase and N-acetylglucosaminidase were examined, including pH and temperature optima and Km values. Chitinase was semi-purified on Fast Protein Liquid chromatography system and activity could be located after native polyacrylamide gel electrophoresis. Analysis of chitinase activity during the growth of the yeast morphology of C.albicans revealed maximal activities during the logarithmic phase, suggesting a relationship of chitinase levels to active growth of the pathogen. It was found that the antibiotic allosamidin was a potent inhibitor of chitinase activity of C.albicans, but not of N-acetylglucosaminidase. Conversely, an analogue of N-acetylglucosamine was found to be a potent inhibitor of N-acetylglucosaminidase but not of chitinase. Treatment of yeast suspensions with allosamidin resulted in an increased chain length. No cell death, or discernible pattern of change in the radiolabelling was observed in the presence of either allosamidin or N-acetylglucosamine analogue. Similarly no consistent change in the optical density of cultures was observed in the presence of either inhibitor. Even in the presence of the membrane permeabilising agent amphotericin no effects were observed above those achieved with amphotericin alone. Comparative studies were carried out upon the chitinolytic activity of Kluyveromyces lactis toxin and bovine serum. The chitin synthetic system of Benjaminiella poitrasii was compared to that of C.albicans.
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Jackson, Deborah Jane. "Chitinase activities from Candida albicans." Thesis, Liverpool John Moores University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337857.
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Peters, D. W. "RNA synthesis in Candida albicans." Thesis, University of Warwick, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373051.
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Clark, Fiona S. "Multidrug resistance in Candida albicans." Thesis, University of Aberdeen, 1994. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU073141.
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Azole-resistance in Candida albicans is becoming common and is associated with the widespread prophylactic use of azoles. Resistance to one azole is usually associated with resistance to other structurally dissimilar azoles. C.albicans is also inherently resistant to a wide range of eukaryotic inhibitors such as cycloheximide and gentamycin. Certain studies have shown that azole-resistance in some strains of C.albicans is associated with alterations in the cell membrane. This project has sought to determine whether azole-resistance in C.albicans strain 3302 was due, at least in part, to a multidrug resistance mechanism. An assay was developed using the fluorescent dye Rh123 to measure P-glycoprotein like activity. Active efflux of Rh123 has been shown to correlate with P-glycoprotein activity in a number of organisms. Results from this assay suggest that an energy-dependent efflux mechanism for Rh123 is present in azole-resistant strain 3302 but not in azole-sensitive strain 3153. The P-glycoprotein inhibitor, reserpine, inhibited Rh123 efflux. However, azoles did not appear to compete with Rh123 for efflux in the azole-resistant strain 3302, suggesting that azole-resistance in this strain is not mediated by a P-glycoprotein like mechanism. Southern analysis showed that sequences homologous to MDR genes existed in C.albicans. A PCR strategy was used to clone gene fragments containing the Walker motif which is found in MDR genes.
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Athukorala, Arachchi Seneviratne Chaminda Jayampath. "Molecular microbiology of candida biofilms." Thesis, Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B4068751X.
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Vaughn, Jill D. "Chemical inhibition of Candida tropicalis." Connect to resource, 1992. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1234698494.
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Favero, Daniel. "Fator hemolítico em Candida tropicalis." Universidade Estadual de Londrina. Centro de Ciências Biológicas. Programa de Pós-Graduação em Microbiologia, 2008. http://www.bibliotecadigital.uel.br/document/?code=vtls000129372.
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Embora o fator hemolítico seja reconhecido como um possível fator que contribui para a patogenicidade de espécies de Candida, a atividade hemolítica de Candida tropicalis e sua expressão ainda permanecem pouco conhecidas. Neste estudo foi analisada a secreção do fator hemolítico em 16 isolados de C. tropicalis provenientes de diversos sítios de infecção (urina, sangue, mucosa oral, escarro, unha e mucosa vaginal). Todos os 16 isolados de C. tropicalis exibiram hemólise-beta (lise completa dos eritrócitos) com um halo externo de hemólise-alfa (lise parcial dos eritrócitos). A atividade do fator hemolítico no sobrenadante de cultivo de C. tropicalis também foi analisada. Similarmente ao encontrado no ensaio em placa, não houve diferenças significativas (P>0,05) na atividade hemolítica entre os isolados testados. Ainda, a atividade hemolítica não foi inibida pelo tratamento com o calor (100°C) ou pela adição de pepstatina A. Em nível molecular, foi identificado um possível gene que confere um fator hemolítico em C. tropicalis (CtHLP) e sua expressão foi avaliada utilizando a técnica de RT-PCR quantitativa (RT-qPCR). Em experimentos preliminares, o emprego de oligonucleotídeos especificamente desenhados para o possível gene CtHLP e para o gene de controle constitutivo CtACT, nos permitiu verificar que possivelmente o fator hemolítico é diferencialmente expresso em função do tempo de incubação. A expressão do gene CtHLP foi máxima em 7 h de incubação em meio RPMI, onde tempos posteriores resultaram em queda na expressão. Os resultados obtidos ampliam nosso conhecimento das bases moleculares e bioquímicas da atividade hemolítica em C. tropicalis.Although haemolytic factor is known to be putative virulence factor contributing to pathogenicity in Candida species, the haemolytic activity of Candida tropicalis and its expression still poor understood. In this study we analyzed the secretion of a haemolytic factor from 16 isolates of C. tropicalis isolated from various clinical sites of infection (urine, blood, buccal mucosa, sputum, nail and vaginal mucosa). All 16 C. tropicalis isolates exhibited both beta-haemolysis (complete lysis of the erythrocytes) with an outer ring of alpha-haemolysis (partial lysis of the erythrocytes). The activity of a haemolytic factor in the culture supernatant of C. tropicalis was also analyzed. Similarly to found in plate assays, there were no significant differences (P>0.05) in the haemolytic activity amongst C. tropicalis isolates. Furthermore, haemolytic activity was neither inhibited by heat treatment (100°C) nor by the addition of pepstatin A. At molecular level, we identify a putative C. tropicalis gene that confers a haemolytic factor (CtHLP) and its expression was evaluated using a quantitative RT-qPCR assay. In preliminary experiments, the employment of the designed specific primers for a putative CtHLP and an active reference control (CtACT gene) allowed us to verify that the putative haemolytic factor is differently expressed as function of the incubation time. The CtHLP was highly expressed up to 7 h incubation in RPMI medium where further incubation resulted in decreased expression. The results obtained extend our knowledge about the biochemical and molecular basis of haemolytic activity in C. tropicalis.
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Lazzarini, C. F. "EPIDEMIOLOGIA DELLE INFEZIONI DA CANDIDA." Doctoral thesis, Università degli Studi di Milano, 2014. http://hdl.handle.net/2434/232580.
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Candida is reported as an important cause of bloodstream infections (BSI) in critical patients such as cancer patients, surgical patients and premature neonates. Neonates are frequently infected or colonised during the stay in the nursery or during the delivery from Candida vaginitis that is a frequent event in pregnant women, particularly during the third trimester. Candidemia is an important challenge for public health as it is associated with severe complications, high mortality, increased length of hospital stay and great economical cost. Most of Candida BSIs develop from an endogenous source such as the colonised gut.
One of the aims of this study was to assess the epidemiology of candidemia and antifungal susceptibility profiles of Candida isolates in Lombardy hospitals through a prospective survey and to evaluate the changes compared to results of a previous survey performed 10 years before in the same region.
A prospective laboratory–based surveillance of candidemia was performed in 2009. The compared data reveal a threefold increase in incidence ( from 0.38 to 1,19 per 1000 admissions), aging of infected patients, an increase in surgical patients (63.8% vs.56%) and decline in crude mortality (from 35 to 27.1%). C. albicans was confirmed as the prevalent species causing candidemia although the rate was a little lower respect the previous survey (52.1% vs. 58.5%). C. glabrata was the second species with a statistically significant increase from 12.8% to 20.3%. Susceptibility testing confirmed the broad spectrum activity of amphotericin B and echinocandins. Decreased susceptibility or resistance to fluconazole was found in 24.9% of the tested isolates. The rate of high biofilm producers among Candida isolates was relevant (25.7%), however no correlation between this micribiological parameter and outcome could be demonstrated.
In a previous study performed in collaboration with Massey University a particular cluster of C. albicans named General Purpose Genotype (GPG) was found more virulent than others in causing candidemia in neonates and was associated with higher mortality rate in this population. The number of cases was low and we wanted to better investigate this association by enlarging the population number. However the introduction of antifungal prophylaxis in the neonatal intensive care units lowered the number of candidemia in this patients population. Therefore we decided to investigate the prevalence of the cluster as cause of vaginitis in pregnant women that is the principal way of infection at birth. GPG strains were detected in 32% of the pregnant women with C. albicans vaginitis and in 34.7% of not-pregnant women. The prevalence of GPG among isolates from African and North African women was statistically significant (62.5% versus 18.2%).
In addition it was investigated the presence of GPG in isolates from patients affected by alimentary tract colonization. The overall prevalence of the cluster was 32.7% without difference among men and women. A similar prevalence of the cluster among isolates causing colonization or candidemia was observed in neonates (34,8% vs. 33.3%). On the contrary in adult patients hospitalized in intensive care unites the rates were statistically different (42.9% vs. 11.9%).
Patients with alimentary tract colonization in different sites were selected for the molecular identification of the strains by multilocus system typing. This was designed to verify if different body sites were colonized by the same strain as predictive tool of deep infection. This part of the study was performed at Massey University. However, due to problems regarding the growth of the strains, only the extraction and the amplification of the DNA was performed until now and the sequencing is in progress.
GPG+ and GPG- isolates were also analyzed to detect differences in susceptibility to antifungal drugs. A decrease susceptibility to fluconazole (geometrical mean 1.53mg/l vs. 0.67mg/l) and a higher rate of resistance to 5-fluorocytosine (30% vs. 0%), were detected in GPG+ isolates.
A boric acid-5-fluorocytosine based cream was suggested by guidelines for the treatment of vaginal candidosis, especially in pregnant women. Our results suggest to looking for GPG strains among vaginal isolates to avoid clinical failures with possible evolution to a chronic infection, more difficult to eradicate, and the possible vertical contamination of the newborns by a strains associated with high crude mortality rate.
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Klippel, Nina. "Interaktionen des humanpathogenen Hefepilzes Candida albicans mit Phagozyten." Tönning Lübeck Marburg Der Andere Verl, 2009. http://d-nb.info/994297548/04.
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Cunha, Ana Cláudia. "O Quilombo de Candeia: um teto para todos os sambistas." reponame:Repositório Institucional do FGV, 2009. http://hdl.handle.net/10438/2696.
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The aim of this study is to reflect on how the cultural initiatives can assert identities and bring new proposals and innovations to social and cultural projects. To achieve this goal I took as study object the Grêmio Recreativo Arte Negra Escola de Samba Quilombo (GRANES Quilombo). Analysing its creation, from 1975 to 1978, I observed how Quilombo represented itself, witch symbolic aspects were used in its words, what were the social relations between its participants, who built a large sociability network in Rio de Janeiro. Quilombo was connected to samba schools universe and to samba and its speeches talked about 'black art', 'Brazilian culture', samba, national identity and tradition.
O objetivo desse estudo é refletir sobre como as iniciativas culturais afirmam suas identidades e podem trazer novas proposições e inovações para a área dos projetos culturais e sociais. Para tal, tomei como objeto de estudo o Grêmio Recreativo Arte Negra Escola de Samba Quilombo (GRANES Quilombo). Por meio da análise de como se constituiu a agremiação, no período entre 1975 e 1978, procurei observar como se representava o Quilombo e concluí que, sob os aspectos simbólicos, construiu seus discursos por meio das relações sociais dos seus participantes, que montaram uma ampla rede de sociabilidade na cidade do Rio de Janeiro. O Quilombo estava ligado ao universo das escolas de samba e do samba e operava com discursos que entrecruzavam concepções sobre 'arte negra', 'cultura brasileira', samba, identidade nacional e tradição.
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Souza, Igor Oliveira Palagi de. "Sais imidazólicos de corantes azóicos e benzimidazóis fluorescentes como marcadores biocidas de biofilmes patogênicos de Candida spp." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/163702.
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por fatores químicos e físicos, promovendo infecções hospitalares relacionadas ao uso de cateteres e demais instrumentos hospitalares, elevando os índices de mortalidade e morbidade de pacientes. Portanto, garantir a correta desinfecção capaz de impedir contaminações e infecções em ambientes hospitalares é de extrema importância. Para este fim, neste estudo explorou-se a seleção de uma substância capaz de marcar e ser biocida contra biofilmes fúngicos em superfícies de aço inox, a partir de nove candidatos benzimidazóis fluorescentes, com códigos NB1 a NB9 e oito sais imidazólicos de corantes azóicos, denominados C4MImErioCr, C10MImMO, C16MImMO, (C10)2MImMO, C4MImMO, C10MImORANGEII, C16MImORANGEII e (C10)2MImORANGEII. Desenvolveu-se para este fim um roteiro metodológico para determinar quais destas substancias são capazes de marcar e eliminar biofilmes de forma eficaz e segura. Os métodos utilizados para avaliar as substâncias foram (1) a Concentração Mínima Inibitória (MIC) conforme protocolo do CLSI M27-A3, (2) microscopias verificando capacidade das substâncias em marcar células, (3) ensaios com deposição sobre superfície do corpo de prova (placas de aço inox) com biofilme, (4) verificação da atividade biocida sobre biofilmes utilizando microscopias e (5) ensaios de citotoxicidade. Essas substâncias foram testadas frente a nove cepas de Candida spp., incluindo C. tropicalis, C. albicans e C. parapsilosis Na avaliação das substâncias, SI de corantes azóicos inibiram o crescimento celular de fungos, já o benzimidazol fluorescente NB7 apresentou atividades simultâneas de detecção e ação biocida sobre o biofilme. Todas as cepas testadas foram sensíveis a essa substância. Além disso, os biofilmes formados pelas cepas ATCC 18804 (C. albicans,) ATCC 22019 (C. parapsilosis) e ATCC 750 (C. tropicalis) na superfície de aço inox 304 sofreram ação biocida, quando expostas por 15 segundos a NB7, sendo um potencial sanitizante.Biofilms provide an environment capable of protecting microbial cells from damage by chemical and physical factors of the immune system, and hinder the penetration of various antimicrobial agents, promoting nosocomial infections related to catheters, increasing mortality and morbidity of patients. Therefore, it is important to ensure proper hygiene to prevent contamination and infections in hospital environments. For this purpose, this study explored the identification of a substance that both detects and have biocide activity against fungal biofilms on stainless steel surfaces. Both nine fluorescent benzimidazole substances, coded NB1 to NB9 and eight imidazolium salts of azo dyes, named denominados C4MImErioCr, C10MImMO, C16MImMO, (C10)2MImMO, C4MImMO, C10MImORANGEII, C16MImORANGEII e (C10)2MImORANGEII were tested as candidates. These substances were tested applying a methodology developed to determine if a substance is able detecting and have biocide activity against fungal biofilms. Overall, this study involved the following methods: (1) Minimum Inhibitory concentration test following the CLSI protocol (M27-A3; the substances were tested against nine fungal strains, including C. tropicalis, C. albicans and C. parapsilosis.), (2) microscopy to determine the marker capacity, (3) spraying tests of the substances on surfaces (stainless steel) with fungal biofilms, (4) tests to verify the capability of the substances to both stain and were biocide against fungal biofilms, applying microscopic techniques and (5) cytotoxicity tests Within the set of seventeen substances, benzimidazole derivative NB7 was identified with the desired capabilities, staining and biocide activity against fungal biofilms at the same time. All tested fungal strains were sensible to this substance. A biocide activity was identified on the biofilms of ATCC 18804 (C. albicans), ATCC 22019 (C. parapsilosis) and ATCC 750 (C .tropicalis), grown on stainless steel 304, when exposed fifteen seconds to substance NB7. Although this substance showed being cytotoxic, it represents a promising candidate for sanitization purposes, including medical tools.
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Neang, Pisey. "Identification et caractérisation fonctionnelle de nouvelles lipases/acyltransférases de levures." Thesis, Montpellier, SupAgro, 2013. http://www.theses.fr/2013NSAM0005/document.
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Les lipases/acyltransférases présentent des propriétés intermédiaires entre les lipases et les acyltransférases. Capables de se comporter comme des hydrolases, elles catalysent cependant la réaction de transfert d'acyle préférentiellement à l'hydrolyse même en milieu aqueux à forte activité thermodynamique de l'eau en présence de divers nucléophiles. La recherche de nouvelles lipases/acyltransférases, soit sécrétées par des levures sauvages, soit identifiées parmi les séquences protéiques disponibles dans des bases de données, nous a permis d'identifier deux nouvelles enzymes de ce type : CvisL2 de Candida viswanathii et CtroL4a de C. tropicalis. Cette dernière, produite par expression hétérologue, a été plus particulièrement étudiée en comparaison avec les deux lipases/acyltransférases déjà connues, CpLIP2 de C. parapsilosis et CaLIP4 de C. albicans, ainsi qu'avec des enzymes plus éloignées (AflaL0a d'Aspergilus flavus, isolée dans ce travail, et CaLA de C. antarctica, qui présentent respectivement 35 % et 31 % d'identité avec CpLIP2). Le caractère spécifique des acyltransférases semble relié à leur degré d'homologie et à leurs relations phylogénétiques. En effet, les trois lipases/acyltransférases étudiées appartiennent à un sous-groupe phylogénétique distinct composé de diverses autres protéines actuellement non-caractérisées présentant plus de 57 % d'identité avec CpLIP2. En plus de leur activité acyltransférase plus ou moins prononcée, ces nouveaux biocatalyseurs diffèrent par leur spécificité de substrat, leur stabilité en présence de fortes concentrations en alcool ou leur activité à basse température, élargissant ainsi le spectre des applications potentielles des lipases et lipases/acyltransférasesLipases/acyltransferases have intermediate properties between lipases and acyltransferases. Although being active hydrolases, they catalyze acyltransfer reactions preferentially to hydrolysis even in an aqueous medium with a high thermodynamic activity of water in the presence of various nucleophiles. Searching for new lipases/acyltransferases, either secreted by wild yeast strains or identified in protein sequences databases, allowed us to identify two new enzymes of this type: CvisL2 from Candida viswanathii and CtroL4a from C. tropicalis. The latter, produced by heterologous expression, has been more particularly studied and compared with the two already known, closely related, lipases/acyltransferases, CpLIP2 from C. parapsilosis and CaLIP4 from C. albicans, and with two more distantly related lipases (a new lipase AflaL0a from Aspergillus flavus and CaLA from C. antarctica, with 35 % and 31 % identity with CpLIP2, respectively). The specific catalytic behavior of the acyltransferases seems to be associated with sequence homology and phylogenetic relationships. Indeed, the three lipases/acyltransferases studied are part of a phylogenetic subgroup composed of various proteins (identity with CpLIP2 higher than 57 %), currently not characterized. Besides their acyltransfer activity, these new biocatalysts differ in properties such as their substrate selectivity, their stability in the presence of high alcohol concentration or their activity at low temperature, opening the way to new applications
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Mardegan, Rita de Cassia. "Atividade inibitoria de extratos vegetais sobre Candida spp e sobre proteinases sintetizados por Candida albicans." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/289371.
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Orientadores : Jose Francisco Hofling, Mary Anny FoglioTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
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Resumo: O uso de extratos vegetais com fins medicinais é uma das mais antigas formas de prática medicinal da humanidade. Visto que nos últimos anos, a freqüência das infecções fúngicas sistêmicas, principalmente as oportunistas invasivas, têm crescido drasticamente o objetivo deste estudo foi: 1 - testar a atividade dos extratos (diclorometanico e metanólico) de Rosmarinus officinalis, Mentha piperita, Casearia sylvestris, Arctium lappa, Arrabidaea chica e Tabebuia avellanedae para determinar o potencial antifúngico em cepas padrão de Cândida spp (C. albicans, C. dubliniensis, C. parapsilosis, C. tropicalis e C. krusei) e em amostras clinicas de Candida albicans através da determinação da Concentração Inibitória Mínima (CIM) e; 2 - avaliar a capacidade desses extratos em inibirem a atividade das proteinases produzidas por C. albicans, um dos mais importantes fatores de virulência dessa espécie. Foram incluídos nos testes para analisar a inibição da atividade proteolítica os inibidores de protease (Amprenavir e Ritonavir) e a Pepstatina A. Nossos resultados demonstraram CIMs variadas em relação a sensibilidade de cada cepa. O extrato metanólico de Arrabidaea chica foi o mais efetivo na inibição do crescimente de várias espécies de Candida, inclusive em relação aos isolados clinicos de C. albicans, seguido dos extratos diclorometanicos de Arctium lappa e Mentha piperita. Nos testes de inibição das proteinases de Candida albicans os que se destacaram foram os extratos diclorometanico de Arrabidaea chica, Casearia sylvestris e Mentha piperita. Desta forma concluímos que o extrato metanólico de A. chica e os extratos diclorometanicos de A. lappa, M. piperita e C. sylvestris obtiveram relevante atividade antifúngica in vitro contra uma variedade de espécies de Candida sendo promissores como agente antifúngico.
Abstract: The use of plants as medicinal substances is one of the most old medicine practices of the humanity. In the last years, the frequency of systemic yeast infection, mainly the opportunistic, has been increased. The overall aims of the present study were: 1 - to test the extract activity (dichloromethane and methanolic) from Rosmarinus officinalis, Mentha piperita, Casearia sylvestris, Arctium lappa, Arrabidaea chica and Tabebuia avellanedae to determine the antifungal activity using strains of Candida spp (C. albicans, C. dubliniensis, C. parapsilosis, C. tropicalis e C. krusei) and in clinical isolates of C. albicans by determination of minimum inhibitory concentration (MIC) and 2 - evaluate the capacity of the extracts to inhibit the activity of proteinases produced by C. albicans, one of the most important virulence factor of these specie. It has been included as a control to evaluate the inhibition of proteolitic activity Amprenavir e Ritonavir and Pepstatina A. Our results showed a variety of MIC patterns according to the strain sensibility. The methanolic extract of Arrabidaea chica was the most effective in inhibiting the growth of a variety of Candida species, including the clinical isolates of C. albicans, followed by dichloromethane extract of Arctium lappa and Mentha piperita. In relation of the proteinases inhibitory tests from C. albicans the most effective extracts tested were dichloromethane of Arrabidaea chica, Casearia sylvestris and Mentha piperita. In conclusion the methanolic extract from A. chica and dichloromethane extracts from A. lappa, M. piperita e C. sylvestris have relevant antifungal activity against a range of Candida specie in vitro and are promising antifungal agents.
Doutorado
Microbiologia e Imunologia
Mestre em Biologia Buco-Dental
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Pereira-Cenci, Tatiana. "Avaliação in vitro da adesão de Candida spp sobre a superficie de resinas acrilicas para base e reembasamento de protese removiveis." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288356.
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Orientadores: Altair Antoninha Del Bel Cury, Renata Cunha Matheus Rodrigues-GarciaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
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Resumo: A candidose é a infecção oral fúngica mais comum diagnosticada em humanos, com prevalência de até 67% em usuários de prótese. Embora tenha sido inicialmente associada apenas a Candida albicans, outras espécies podem ser responsáveis por mais de 50% dos casos de infecção. Ainda, fatores como presença de saliva e bactérias parecem desempenhar importante papel na colonização por Candida. Assim, este estudo objetivou verificar a influência destes fatores na a:fesão de duas espécies de Candida (Candida albicans e Candida glabrata) sobre a superfície de resinas acrílicas e reembasadores. Corpos de prova (2,5x1 ,2xO,2 cm) confeccionados com duas resinas acrílicas (convencional e de microondas) e dois reembasadores (temporário e permanente) tiveram sua rugosidade (Ra) e energia livre de superfície (ELS) mensuradas, sendo aleatoriamente divididos de acordo com a exposição aos fatores: presença ou ausência de saliva, presença ou ausência de bactérias e espécie de Candida. Os espécimes foram levados a uma câmara de fluxo utilizando-se uma bomba peristáltica para perfusão de cultura de bactérias seguida por uma das espécies de Candida, ou apenas a cultura de uma das espécies de Candida. A contagem das células de Candida aderidas foi realizada em microscópio óptico (400x). Os dados foram submetidos à análise de variância para Ra e adesão, e ao teste de Kruskal-Wallis para ELS (a=0,05). O reembasador temporário apresentou a maior Ra, seguido do permanente, enquanto as resinas acrílicas exibiram as menores rugosidades (p<0,0001). Os valores de ELS foram similares para os materiais, mas diferentes do reembasador temporário (p<0,0001). A adesão de C. albicans e C. glabrata variou de 3,2 a 564,4 e 3,2 a 1400,4 cel/mm2 respectivamente, com diferenças estatísticas (p<0,05) em alguns grupos. O reembasador temporário mostrou maiores níveis de adesão. A colonização foi diminuída pela saliva, enquanto na presença de bactérias e saliva houve aumento da adesão (p<0,05). Estes resultados sugerem que a adesão inicial das duas espécies de Candida foi fortemente afetada pela rugosidade, presença de saliva e bactérias, mas não pela energia livre de superfície
Abstract: Candida-associated stomatitis is reported in up to 67% of a population wearing dentures. Recently, disease-associated Candida species have shifted from C. albicans to norralbicans species. Since factors such as presence of saliva and oral bacteria appear to play a major role in the initial phases of yeasts adhesion, this study aimed to determine whether these factors produced differences in acrylic resins and denture liners C. albicans and C. glabrata adherence. Samples (2.5x1.2xO.2 em) of two acrylic resins (heat and microwavecured) and two denture liners (soft and hard) were prepared and had their surface free energy (SFE) and surface roughness (Ra) measured and were randomly divided according to their exposure to the following factors: saliva coating or uncoating, presence or absence of bacteria and Candida species. Specimens were assayed in a flow chamber connected to a peristaltic pump for perfusion of bacteria culture plus one of the Candida species culture or only the Candida culture (control). Adhesion was determined by count on a light microscope (400 x). Statistical analyses was performed by ANOVA (Ra and Candida species adhesion) and Kruskal-Wallis (SFE) (a=.05). Soft liner presented the roughest surface, followed by the hard liner, whereas acrylic resins exhibited the smoothest surfaces (p<.0001). The SFE values of ali materiais were similar but different from the soft liner (p<.0001). C. albicans and C. glabrata adhesion on the materiais ranged fr0m 3.2 to 564.4, and 3.2 to 1400.4 cells mm-2 respectively, with statistically signific,ant differences (p<.05) in some cases. The soft liner exhibited the highest levels of adhesion. The overall colonization was significantly decreased by saliva (p<.Oq), while bacteria increased the adhesion in the presence of saliva. These results taken together suggest that initial adhesion of Candida species was strongly affected by the surface roughness, presence of saliva and bacteria, but not by surface free energy
Mestrado
Protese Dental
Mestre em Clínica Odontológica
50
Leung, Hing-cheung. "Aspects of leaf litter decomposition in Kandelia candel (L.) Druce /." [Hong Kong : University of Hong Kong], 1986. http://sunzi.lib.hku.hk/hkuto/record.jsp?B12326082.
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