Thesis (Magister Technologiae - Discipline Electrical Engineering, Faculty of Engineering) -- Vaal University of Technology / Discomfort glare is a topic that has been investigated for many years without any reasonable explanation regarding its effect on the human visual system. Results of previous research concluded that established methods have a lot of similarities in implementation; but a number of differences when comparing the results of observer's evaluations with the mathematically calculated glare ratings. Therefore, an alternative method of evaluating the influence of exposure to an unshielded light source was investigated to establish a more reliable and realistic response from observers. In order to address the discrepancies of previous evaluation systems concerning observer's varying opinions regarding the level of discomfort experienced, it was decided to investigate the feasibility of evaluating the brain activity of the observers exposed to an unshielded incandescent lamp. This was done in order to facilitate the differences in each individual observer's sensitivity to bright light sources and the influence of personal taste therefore, eliminating the effect of personal interpretation. The main purpose of this study was to determine whether it would be possible to get any response regarding brain functions when an observer is exposed to a bare light source. In order to determine the pathway of visual stimuli it was necessary to investigate the operating principles of the human eye in detail. Because the eye is only an instrument that makes seeing possible; it was also important to investigate the brain and all its different functions. The part of the brain where visual interpretation takes place was indicated as the occipital lobe. This is the part of the brain monitored for any change of functional status by taking measurements with an electroencephalogram (EEG). Measurements were indeed possible; it was presented as a suppression of the alpha brain activity. During the testing procedure it was observed that the observers were not equally photosensitive. There was also a difference in the amount of alpha suppression with the observer's eyes open and closed respectively. Because the alpha rhythm has a tendency to increase with closed eyes it was much easier to notice the suppression.

L’élaboration de nouveaux complexes métalliques possédant des propriétés physiquesintéressantes et multiples est un cadre de recherche très actif ces dernières années.Parallèlement, les molécules dérivées d’énaminones fluoroalkylées sont modifiables à souhaitet sont reconnues pour leur utilisation en tant que ligand. Ces synthons se révèlent alorsparticulièrement adaptés pour élaborer des complexes variés via des techniques de chimie decoordination.Dans ce contexte, un programme de recherche a été récemment initié et consiste en lasynthèse de ligands de type énaminone trifluorométhylée bi, tri et tétradentes pouvant êtremodifiés en fonction des propriétés ciblées. Ainsi, la substitution du motif par des unités detype azobenzène, anthracène, tétrathiafulvalène, 1,2,3-triazole… a permis de révéler pourceux-ci une photosensibilité, une activité redox ou encore une bioactivité.De plus, au travers de leur différence de denticité, ces ligands conduisent à descomplexes métalliques de nucléarité contrôlée. Ainsi ce sont des composés mononucléairesd’une part et polynucléaires d’autre part qui sont obtenus pour lesquels une propriété redox etmagnétique est observée respectivement.Ainsi, le projet est dédié à l’élaboration d’objets moléculaires innovants etpolyfonctionnels au sein desquels cohabitent une propriété portée par le ligand organiquestructurant et une propriété issue du coeur métallique central. / The synthesis of new metal hybrid inorganic-organic metallic complexes with severalinteresting physical properties is an area of intense research. On another hand, fluoroalkylatedenaminone derivatives have been scarcely employed as useful ligands although these organicmolecules can offer very rich coordination chemistry with broad applications in materialsscience.In this context, a research program was recently initiated, dedicated to thedevelopment of bi, tri, and tetradentate trifluoromethylated enaminone ligands that can bemodified according to the targeted properties. Indeed, a photosensitivity, a redox property or abioactivity was found for these ligands with the introduction of units such as azobenzene,anthracene, tetrathiafulvalene, 1,2,3-triazole …In addition, according to their different denticity, these ligands can afford somemetallic complexes with a controlled nuclearity. In one hand, mononuclear complexes areobtained with a redox property and in antoher hand some polynuclear complexes withinteresting magnetic behaviours.The research program is thus dedicated to the elaboration of innovating andpolyfunctionnal molecular objects in which a property arising from the organic structuringligand coexists with the property of the metallic center.

The different topics of this thesis include high-temperaturestable fiber Bragg gratings, photosensitivity and fiber basedcomponents. Fiber Bragg gratings (FBG) are wavelength dispersiverefractive index structures manufactured through UV exposure ofoptical fibers. Their applications range from WDM filters,dispersion compensators and fiber laser resonators fortelecommunication applications to different types of point ordistributed sensors for a variety of applications. One aim of this thesis has been to study a new type of FBGreferred to as chemical composition grating. These gratingsdiffer from other types of FBG in that their refractive indexstructure is attributed to a change in the chemicalcomposition. Chemical composition gratings have shown to beextremely temperature stable surviving temperatures in excessof 1000 oC. Photosensitivity of pure silica and germanium-dopedcore fibers in the presence of hydroxyl groups has also beenstudied and different types of fiber based components have beendeveloped. The main result of the thesis is a better understanding ofthe underlying mechanism of the formation of chemicalcomposition gratings and their decay behavior at elevatedtemperatures. The refractive index modulation is caused by aperiodic change in the fluorine concentration, which has beenverified through time-of-flight secondary-ion-mass spectrometryand through studies of the decay behavior of chemicalcomposition gratings. A model based on diffusion of dopants hasbeen developed, which successfully predicts the thermal decayat elevated temperatures. Studies of the dynamics of chemicalcomposition grating formation have resulted in a manufacturingtechnique that allows for reproducible gratingfabrication. The main results regarding photosensitivity is a method tosignificantly increase the effect of UV radiation on standardtelecommunications fiber. The method, referred to asOH-flooding, has also been applied to pure-silica core fibersresulting in the first report of strong grating formation insuch fibers. Finally, research into different schemes for developingfiber-based components has resulted in two types of singlefiber integrated Mach-Zehnder interferometers; one passiveinterferometer that can be used as an optical filter and oneactive interferometer controlled with internal metalelectrodes. Keywords:optical fibers, fiber Bragg gratings,photosensitivity, thermal stability, fiber sensors, chemicalcomposition gratings, fiber components, Mach-Zehnderinterferometer, optical switch, optical modulator. / QC 20100607

The main topic of this thesis work is photosensitivity and photo-structuring of optical fibers and bulk glass. Although research in the field of photosensitivity in glass and optical fibers has been ongoing for more than three decades, the underlying mechanisms are still not well understood. The objective was to gain a better understanding of the photo-response by studying photosensitivity from a thermodynamic perspective, as opposed to established research focusing on point defects and structural changes, and strain and stress in optical fibers. Optical fibers was mainly used for experimental studies for two reasons; first, photosensitivity in fibers is more pronounced and more elusive compared to its bulk counterpart, and secondly, fibers provide a simplified structure to study as they experimentally can be seen as one-dimensional.Initially, ablation experiments on bulk glass were performed using picosecond infrared pulses. With a design cross section of 40x40 μm, straight channels were fabricated on the top (facing incident light) and bottom side of the sample and the resulting geometries were analyzed. The results show a higher sensitivity to experimental parameters for bottom side ablation which was ascribed to material incubation effects. Moreover, on the top side, the resulting geometry has a V-shape, independent of experimental parameters, related to the numerical aperture of the focusing lens, which was ascribed to shadowing effects.After this work, the focus shifted towards optical fibers, UV-induced fiber Bragg gratings (FBGs) and thermal processing with conventional oven and with a CO2 laser as a source of radiant heat.First, a system for CO2 laser heating of optical fibers was constructed. For measuring the temperature of the processed fibers, a special type of FBG with high temperature stability, referred to as "Chemical Composition Grating" (CCG) was used. A thorough characterization and temperature calibration was performed and the results show the temperature dynamics with a temporal resolution of less than one millisecond. The temperature profile of the fiber and the laser beam intensity profile could be measured with a spatial resolution limited by the grating length and diameter of the fiber. Temperatures as high as ~ 1750 °C could be measured with corresponding heating and cooling rates of 10.500 K/s and 6.500 K/s.Subsequently, a thorough investigation of annealing and thermal regeneration of FBGs in standard telecommunication fibers was performed. The results show that thermal grating regeneration involves several mechanisms. For strong regeneration, an optimum annealing temperature near 900 C was found. Two different activation energies could be extracted from an Arrhenius of index modulation and Braggv iwavelength, having a crossing point also around 900 °C, indication a balance of two opposing mechanisms.Finally, the thermal dynamics and spectral evolution during formation of long period fiber gratings (LPGs) were investigated. The gratings were fabricated using the CO2 laser system by periodically grooving the fibers by thermal ablation. Transmission losses were reduced by carefully selecting the proper processing conditions. These parameters were identified by mapping groove depth and transmission loss to laser intensity and exposure time. / Huvudtemana i denna avhandling är fotokänslighet och fotostrukturering av optiska fibrer och bulk glas. Trots att forskning inom fotokänslighet i glas och optiska fibrer har pågått under mer än tre decennier är de bakomliggande mekanismerna ännu inte klarlagda. Syftet var att få en bättre förståelse för fotoresponsen genom att studera fotokäsligheten ur ett termodynamiskt perspektiv, i motsats till etablerad forskning med fokus på punktdefekter och strukturförändringar, samt mekaniska spännings effekter i optiska fibrer. Optiska fibrer användes för flertalet av de experimentella studierna av två skäl; för det första är fotokänsligheten i fibrer större och dessutom vet man mindre om bakomliggande mekanismer jämfört med motsvarande bulk glas, och för det andra kan fibrer vara enklare att studera eftersom de experimentellt kan ses som en endimensionell struktur.Inledningsvis utfördes ablaherings experiment på bulk glas med en infraröd laser med pikosekund pulser. Raka kanaler med ett designtvärsnitt på 40x40 μm tillverkades på ovansidan (mot infallande ljus) och bottensidan av provet och de resulterande geometrierna analyserades. Resultaten visar en högre känslighet för variationer i experimentella parametrar vid ablahering på undersidan vilket kan förklaras av inkubations effekter i materialet. Dessutom är den resulterande geometrin på ovansidan V-formad, oavsett experimentella parametrar, vilket kunde relateras till den numeriska aperturen hos den fokuserande linsen, vilket förklaras av skuggningseffekter.Efter detta arbete flyttades fokus mot optiska fibrer, UV inducerade fiber Bragg gitter (FBG), och termisk bearbetning med konventionell ugn samt även med en CO2-laser som källa för strålningsvärme.Först konstruerades ett system för CO2-laservärmning av fibrer. För mätning av temperaturen hos bearbetade fibrer användes en speciell sorts FBG med hög temperaturstabilitet, kallade ”Chemical Composition Gratings” (CCG). En grundlig karaktärisering och temperaturkalibrering utfördes och temperaturdynamiken mättes med en tidsupplösning på under en millisekund. Temperaturprofilen i fibern, och laserns strålprofil, kunde mätas med en spatiell upplösning begränsad av gitterlängden och fiberns diameter. Temperaturer upp till ~1750 °C, vilket är högre än mjukpunktstemperaturen, kunde mätas med korresponderande uppvärmnings- och avsvalningshastighet på 10.500 K/s och 6.500 K/s.Därefter gjordes en omfattande undersökning av värmebearbetning och termisk regenerering av FBG:er i telekomfiber. Resultaten visar att termisk gitter-regenerering aktiveras av flera olika mekanismer. Värmebearbetning vid en temperatur omkring 900 °C resulterade i starka gitter efter en regenerering vid en temperatur på 1100 °C. Två olika aktiveringsenergier kunde extraheras från en Arrhenius plot avseende brytningsindexmodulation och Braggvåglängd, med en skärningspunkt tillika runt 900 °C, vilket indikerar en avvägning mellan två motverkande mekanismer vid denna temperatur.Slutligen undersöktes temperaturdynamiken och de spektrala egenskaperna under tillverkning av långperiodiga fibergitter (LPG). Gittren tillverkades med CO2-vi iilasersystemet genom att skapa en periodisk urgröpning medelst termisk ablahering. Transmissionsförluster kunde reduceras med noggrant valda processparametrar. Dessa parametrar identifierades genom mätningar av ablaherat djup och transmissionsförlust som funktion av laserintensitet och exponeringstid. / <p>QC 20150924</p>

Introdução: A Síndrome de Kindler é uma doença autossômica recessiva que se caracteriza por surgimento de bolhas acrais na infância que diminuem com o passar dos anos, fotossensibilidade, poiquilodermia persistente e progressiva e atrofia cutânea. Desde o primeiro relato, mais de 100 casos já foram descritos, mas a associação com Poiquilodermia Acroceratótica e Epidermólise Bolhosa tem freqüentemente dificultado o diagnóstico. Exames moleculares nunca foram realizados em paciente brasileiros com Síndrome de Kindler. Objetivos: O objetivo deste estudo é a identificação de alterações genéticas e estruturais nos pacientes com Síndrome de Kindler do sul do Brasil. Pacientes e métodos: Este estudo é uma série de casos de sete pacientes acompanhados no Hospital de Clínicas de Porto Alegre durante o período de janeiro de 2004 a dezembro de 2005. Os pacientes com SK foram examinados clinicamente e o registro foi realizado em um questionário estruturado. As amostras de pele e sangue foram coletadas após consentimento informado com a aprovação pelo comitê de ética. Resultados: Os achados clínicos mais consistentes para o diagnóstico foram bolhas na infância, fotossensibilidade e poiquilodermia. A ocorrência de carcinomas de pele não melanomas em dois pacientes jovens sugere que a SK pode ser um fator de risco no desenvolvimento de malignidades cutâneas. Uma mutação no exon 5 foi identificada nas duas famílias distintas que após o heredograma mostraram ter parentes em comum que vieram da mesma região da Itália há três gerações. Conclusões: Estes achados são muito importantes para a descrição de uma síndrome tipicamente caracterizada e para incrementar a estratégia de detecção. A elucidação das mutações existentes é igualmente importante para o desenvolvimento de novos tratamentos e manejos dos pacientes afetados. / Background: Kindler syndrome (KS) is a rare autossomal recessive disease characterized by acral bullae in infancy that diminished with time, photosensitivity, persistent progressive poikiloderma and severe cutaneous atrophy. Since the first report more than 100 cases have already been described but the association with acrokeratotic poikiloderma and epidermolysis bullosa has often misled the diagnosis. The molecular study of Brazilian patients with Kindler syndrome was never performed. Objectives: To asses the clinical features and the molecular basis of KS in patients from South Brazil and to examine molecular evidence for a mutation. Patients and methods: This study is a series of seven patients atending to Hospital de Clinicas de Porto Alegre during the period of January 2004 to December 2005. The KS affected individuals were examined clinically and a structured recording sheet was completed. Blood and skin samples were collected after informed consent and with the Ethics committee approval. Results: The most consistent clinical signs for a diagnosis were blisters in childhood, photosensitivity and poikiloderma. The occurrence of non-melanoma skin cancers in two of the affected individuals at a relatively young age suggests that patients with KS may be prone to cutaneous malignancy. A mutation in exon 5 was identified in the two distinct families that after family tree showed to have relatives in common that came from the same region in Italy more than three generations ago. Conclusions: These findings are very important to report a rare but well characterized syndrome and to increment detection strategies. The elucidation of the existent mutations is equally important in the developing of new treatments and in the management of the affected patients.

Made available in DSpace on 2014-10-09T12:26:20Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:18Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2015-05-20T18:06:29Z No. of bitstreams: 0 / Made available in DSpace on 2015-05-20T18:06:29Z (GMT). No. of bitstreams: 0 / Tese (Doutorado em Tecnologia Nuclear) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Introdução: A Síndrome de Kindler é uma doença autossômica recessiva que se caracteriza por surgimento de bolhas acrais na infância que diminuem com o passar dos anos, fotossensibilidade, poiquilodermia persistente e progressiva e atrofia cutânea. Desde o primeiro relato, mais de 100 casos já foram descritos, mas a associação com Poiquilodermia Acroceratótica e Epidermólise Bolhosa tem freqüentemente dificultado o diagnóstico. Exames moleculares nunca foram realizados em paciente brasileiros com Síndrome de Kindler. Objetivos: O objetivo deste estudo é a identificação de alterações genéticas e estruturais nos pacientes com Síndrome de Kindler do sul do Brasil. Pacientes e métodos: Este estudo é uma série de casos de sete pacientes acompanhados no Hospital de Clínicas de Porto Alegre durante o período de janeiro de 2004 a dezembro de 2005. Os pacientes com SK foram examinados clinicamente e o registro foi realizado em um questionário estruturado. As amostras de pele e sangue foram coletadas após consentimento informado com a aprovação pelo comitê de ética. Resultados: Os achados clínicos mais consistentes para o diagnóstico foram bolhas na infância, fotossensibilidade e poiquilodermia. A ocorrência de carcinomas de pele não melanomas em dois pacientes jovens sugere que a SK pode ser um fator de risco no desenvolvimento de malignidades cutâneas. Uma mutação no exon 5 foi identificada nas duas famílias distintas que após o heredograma mostraram ter parentes em comum que vieram da mesma região da Itália há três gerações. Conclusões: Estes achados são muito importantes para a descrição de uma síndrome tipicamente caracterizada e para incrementar a estratégia de detecção. A elucidação das mutações existentes é igualmente importante para o desenvolvimento de novos tratamentos e manejos dos pacientes afetados. / Background: Kindler syndrome (KS) is a rare autossomal recessive disease characterized by acral bullae in infancy that diminished with time, photosensitivity, persistent progressive poikiloderma and severe cutaneous atrophy. Since the first report more than 100 cases have already been described but the association with acrokeratotic poikiloderma and epidermolysis bullosa has often misled the diagnosis. The molecular study of Brazilian patients with Kindler syndrome was never performed. Objectives: To asses the clinical features and the molecular basis of KS in patients from South Brazil and to examine molecular evidence for a mutation. Patients and methods: This study is a series of seven patients atending to Hospital de Clinicas de Porto Alegre during the period of January 2004 to December 2005. The KS affected individuals were examined clinically and a structured recording sheet was completed. Blood and skin samples were collected after informed consent and with the Ethics committee approval. Results: The most consistent clinical signs for a diagnosis were blisters in childhood, photosensitivity and poikiloderma. The occurrence of non-melanoma skin cancers in two of the affected individuals at a relatively young age suggests that patients with KS may be prone to cutaneous malignancy. A mutation in exon 5 was identified in the two distinct families that after family tree showed to have relatives in common that came from the same region in Italy more than three generations ago. Conclusions: These findings are very important to report a rare but well characterized syndrome and to increment detection strategies. The elucidation of the existent mutations is equally important in the developing of new treatments and in the management of the affected patients.

Introdução: A Síndrome de Kindler é uma doença autossômica recessiva que se caracteriza por surgimento de bolhas acrais na infância que diminuem com o passar dos anos, fotossensibilidade, poiquilodermia persistente e progressiva e atrofia cutânea. Desde o primeiro relato, mais de 100 casos já foram descritos, mas a associação com Poiquilodermia Acroceratótica e Epidermólise Bolhosa tem freqüentemente dificultado o diagnóstico. Exames moleculares nunca foram realizados em paciente brasileiros com Síndrome de Kindler. Objetivos: O objetivo deste estudo é a identificação de alterações genéticas e estruturais nos pacientes com Síndrome de Kindler do sul do Brasil. Pacientes e métodos: Este estudo é uma série de casos de sete pacientes acompanhados no Hospital de Clínicas de Porto Alegre durante o período de janeiro de 2004 a dezembro de 2005. Os pacientes com SK foram examinados clinicamente e o registro foi realizado em um questionário estruturado. As amostras de pele e sangue foram coletadas após consentimento informado com a aprovação pelo comitê de ética. Resultados: Os achados clínicos mais consistentes para o diagnóstico foram bolhas na infância, fotossensibilidade e poiquilodermia. A ocorrência de carcinomas de pele não melanomas em dois pacientes jovens sugere que a SK pode ser um fator de risco no desenvolvimento de malignidades cutâneas. Uma mutação no exon 5 foi identificada nas duas famílias distintas que após o heredograma mostraram ter parentes em comum que vieram da mesma região da Itália há três gerações. Conclusões: Estes achados são muito importantes para a descrição de uma síndrome tipicamente caracterizada e para incrementar a estratégia de detecção. A elucidação das mutações existentes é igualmente importante para o desenvolvimento de novos tratamentos e manejos dos pacientes afetados. / Background: Kindler syndrome (KS) is a rare autossomal recessive disease characterized by acral bullae in infancy that diminished with time, photosensitivity, persistent progressive poikiloderma and severe cutaneous atrophy. Since the first report more than 100 cases have already been described but the association with acrokeratotic poikiloderma and epidermolysis bullosa has often misled the diagnosis. The molecular study of Brazilian patients with Kindler syndrome was never performed. Objectives: To asses the clinical features and the molecular basis of KS in patients from South Brazil and to examine molecular evidence for a mutation. Patients and methods: This study is a series of seven patients atending to Hospital de Clinicas de Porto Alegre during the period of January 2004 to December 2005. The KS affected individuals were examined clinically and a structured recording sheet was completed. Blood and skin samples were collected after informed consent and with the Ethics committee approval. Results: The most consistent clinical signs for a diagnosis were blisters in childhood, photosensitivity and poikiloderma. The occurrence of non-melanoma skin cancers in two of the affected individuals at a relatively young age suggests that patients with KS may be prone to cutaneous malignancy. A mutation in exon 5 was identified in the two distinct families that after family tree showed to have relatives in common that came from the same region in Italy more than three generations ago. Conclusions: These findings are very important to report a rare but well characterized syndrome and to increment detection strategies. The elucidation of the existent mutations is equally important in the developing of new treatments and in the management of the affected patients.

Made available in DSpace on 2014-10-09T12:26:20Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:18Z (GMT). No. of bitstreams: 0 / Um estudo das propriedades ópticas do cromóforo hipocrelina B (HB) e de seus complexos com os íons lantânio (La3+), európio (Eu3+) e térbio (Tb3+) em soluções em etanol foi realizado. Tal pigmento enquadra-se como um promissor fotossensibilizador de segunda geração dadas suas ótimas propriedades, tais como rápido metabolismo in vivo e principalmente elevado rendimento quântico de geração de oxigênio singleto (FD). O presente trabalho foi desenvolvido em duas etapas: a primeira consistiu do estudo espectroscópico dos complexos de hipocrelina B (HB) com os íons lantanídeos (Ln3+), e a segunda, de testes de PDT in vitro em cultura do fungo Candida albicans. Na primeira etapa do trabalho, a melhor razão molar entre HB e Ln3+ foi verificada através do monitoramento do pico de absorção em maior comprimento de onda de cada um dos complexos. O maior deslocamento do pico de absorção da HB (de 589 nm para 614 nm) foi notado para os complexos com razão de 1 mol de HB para 2 mols de íon lantanídeo. Observou-se que a emissão da HB e de seus complexos ocorre desde cerca de 600 nm até 750 nm. Foi possível, com base nos espectros de absorção e de emissão, calcular os valores de níveis de energia da molécula e de seus complexos. Todos os fotossensibilizadores apresentaram como menor nível de energia valor superior a 0,98 eV, o que é um indício de sua capacidade de geração de oxigênio singleto. Foram determinadas as constantes de dimerização das amostras, de maneira a identificar sua tendência à formação de dímeros ou agregados de ordem superior, e os valores obtidos para a HB e seus complexos com lantânio, európio e térbio foram, respectivamente, de 4,7.104, 3,6.105, 2,1.105 e 1,0.105 M-1. Todas as amostras mostraram-se estáveis perante a ação de luz de 532 nm de até 400 mW/cm2 de intensidade pelo período de uma hora de irradiação. As capacidades de geração de oxigênio singleto das amostras foram determinadas tanto através do método espectroscópico direto (detecção da emissão do oxigênio singleto em torno de 1270 nm) quanto do método químico indireto (variações na absorção em 440 nm do composto RNO). Notou-se que para a HB o método direto indicou haver geração de oxigênio singleto, e o método químico revelou que esta espécie é gerada à taxa de 2,8.10-4 s-1; para HB:La3+ (1:1) obteve-se aumento de 32% na geração de oxigênio singleto em relação à HB, e para HB:La3+ (1:2), determinou-se taxa de 3,0.10-4 s-1 pelo método indireto. Com base nos dados experimentais obtidos, verificou-se que o melhor dentre os complexos estudados foi o HB:La3+ (1:2), sendo este e seu precursor HB então aplicados em testes de PDT antimicrobiana in vitro, constituindo a segunda etapa do trabalho. A concentração de HB ideal para trabalho obtida foi de 10 M. Notou-se eliminação total de microorganismos com apenas 30 segundos de irradiação com LED de 460 nm e intensidade de 333 mW/cm2 tanto para o complexo como para o seu precursor. Porém, com excitação em 660 nm com esta mesma intensidade, apenas HB:La3+ (1:2) se mostrou efetivo, chegando ao efeito fotodinâmico total após 6 minutos de irradiação; a redução causada pela HB no mesmo intervalo de tempo foi bem menos pronunciada, o que comprova a eficiência do fotossensibilizador produzido. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP