This paper reports a reciprocal Mach-Zehnder interferometer in a dual Sagnac ring configuration, and one of two arms in Mach-Zehnder interferometer is used for underwater optic fiber hydrophone. Two Mach-Zehnder interferometers operated in opposite sense are simultaneously induced from the underwater acoustic wave and the PZT phase modulation. Thus, at the output, four interferometric beams occur such that the intensity of interferometric beams will enhance. In general, one stage of a double Mach-Zehnder interferometer is just used as a sensor, another one for compensation. Specially, this paper presents two stages of a double Mach-Zehnder interferometer sense the measurand at the same time due to the topology structure of Sagnac ring pairs. In the other words, the characteristic is to win the affection of two beauties at the same time. Two rings in the same direction make a Mach-Zehnder interferometer. Besides, the inner ring in the clockwise direction and the outer one in the counterclockwise direction also make a Mach-Zehnder interferometer. So as to the unbalanced arms of the Mach-Zehnder interferometer, the underwater acoustic wave induces the light beam phase difference in optic fiber hydrophone interrogator to demodulate the acoustic wave signal by PGC circuit.

Coding is an essential technology for efficient fiber-optic communications and secure quantum communications. In particular, low-density parity-check (LDPC) coding is favoured due to its strong error correction capability and high-throughput implementation feasibility. In fiber-optic communications, it has been realized that advanced high-order modulation formats and soft-decision forward error correction (FEC) such as LDPC codes are the key technologies for the next-generation high-speed optical communications. Therefore, energy-efficient LDPC coding in combination with advanced modulation formats is an important topic that needs to be studied for fiber-optic communications. In secure quantum communications, large-alphabet quantum key distribution (QKD) is becoming attractive recently due to its potential in improving the efficiency of key exchange. To recover the carried information bits, efficient information reconciliation is desirable, for which the use of LDPC coding is essential. In this dissertation, we first explore different efficient LDPC coding schemes for optical transmission of polarization-division multiplexed quadrature-amplitude modulation (QAM) signals. We show that high energy efficiency can be achieved without incurring extra overhead and complexity. We then study the transmission performance of LDPC-coded turbo equalization for QAM signals in a realistic fiber link as well as that of pragmatic turbo equalizers. Further, leveraging the polarization freedom of light, we expand the signal constellation into a four-dimensional (4D) space and evaluate the performance of LDPC-coded 4D signals in terms of transmission reach. Lastly, we study the security of a proposed weak-coherent-state large-alphabet QKD protocol and investigate the information reconciliation efficiency based on LDPC coding.

Proteins possess a broad range of structural and functional properties and, therefore, can be employed in a variety of biomedical applications. While a good number of protein-based biosensing systems and biosensors for target analytes have been developed, the search for versatile, highly sensitive and selective sensors with long term stability able to provide fast detection of target analytes continues to be a challenge. To that end, we now report the design and development of modified proteins with tailored characteristics and their further utilization in the development of biosensing systems. We take advantage of binding proteins that undergo a change in conformation upon binding to their respective target ligand analytes for the development of highly selective biosensing systems. The first class of binding proteins that was explored for this purpose was antibodies. A non-canonical site in the variable region of a monoclonal antibody was tagged with a fluorescent probe to sense the binding of analyte to its corresponding antigen-binding site. The strategy employed for designing antibodysensing molecules is universal as it can be employed for sensing any biomolecule of interest provided that there is an available antibody against the target ligand analyte. In a second strategy, we utilized designer glucose recognition proteins (GRPs) that were prepared by incorporation of unnatural amino acids in the glucose/galactose binding protein (GBP) of Escherichia coli and its truncated fragments. By taking advantage of the global incorporation method, we were able to fine-tune the binding affinity and thermal stability of the proteins, thus, allowing for the development of a reagentless fluorescence based fiber optic glucose biosensor capable of monitoring glucose in the hypoglycemic, normal, and hyperglycemic range, as well as in the hypothermic and hyperthermic temperature range.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / O objetivo do presente trabalho foi avaliar in vivo a detecção de cárie através do exame visual ICDAS, transiluminação por fibra ótica combinado ao ICDAS e exame radiográfico. Um total de 2.279 superfícies proximais e cicatrículas e fissuras em incisivos superiores, pré-molares e molares permanentes e 272 superfícies em molares decíduos em72 escolares (8 a 18 anos) foram avaliadas por um examinador treinado. Os sete escores para detecção de cárie primária do sistema visual ICDAS foram aplicados. Dois equipamentos de transiluminação por fibra ótica foram avaliados: FOTI Schott (SCH), com ponta de fibra ótica com 0,5mm de diâmetro, e FOTI Microlux (MIC), com diâmetro da ponta 3 mm. Durante o exame combinado FOTI/ICDAS, a fibra ótica era utilizada tanto para iluminar quanto para transiluminar a superfície sob avaliação. O exame radiográfico (RX) consistiu de radiografias interproximais posteriores e periapicais anteriores. Os exames foram realizados em consultório odontológico após escovação supervisionada. No primeiro dia de exame, o exame visual utilizando o ICDAS era realizado e em seguida, o exame combinado ao MIC ou SCH. Logo após era realizado o exame radiográfico. Após uma semana, novamente o ICDAS era realizado, e em seguida o exame combinado com o equipamento de FOTI não utilizado na semana anterior. Os exames foram repetidos em 10 pacientes após intervalo mínimo de uma semana para avaliação da reprodutibilidade intra-examinador, a qual apresentou valores de 0,95 (ICDAS), 0,94 (MIC), 0,95 (SCH) e 0,99 (RX) pelo kappa ponderado. Em cicatrículas e fissuras de permanentes, o RX julgou que um número maior de superfícies apresentava lesão em dentina (53) do que os outros métodos (34 a 36); porém não detectou nenhuma lesão em esmalte, as quais foram identificadas pelo ICDAS (94), SCH (107) e MIC (91). Em proximais permanentes, a transiluminação por fibra ótica identificou maior número de proximais como lesão em esmalte - 150 (SCH) e 139 (MIC) - do que o exame visual (106), enquanto o RX identificou somente 43. Em oclusais de decíduos, os quatro métodos julgaram um número aproximadamente similar de superfícies sem lesão (52 a 59) ou com lesão em dentina (21 a 26), assim como para lesões proximais em dentina (31 a 36). Entretanto um número reduzido de lesões proximais decíduas em esmalte foi julgado pelo exame radiográfico (3) em comparação com os outros métodos (15 a 16). Em decíduos, o ICDAS e o FOTI combinado ao exame visual julgaram maior número de lesões proximais em esmalte que o exame radiográfico, sendo que número similar de lesões em dentina foram classificadas pelos quatro métodos em oclusais e proximais de molares decíduos. Em cicatrículas e fissuras de permanentes, tanto o exame visual ICDAS quanto sua combinação aos dois equipamentos de transiluminação apresentaram maior similaridade de superfícies julgadas como lesão em esmalte ou como lesão em dentina, enquanto o exame radiográfico classificou mais superfícies como lesão em dentina e nenhuma como lesão em esmalte. A adição da transiluminação por fibra ótica ao exame visual aumentou em um terço a detecção das lesões cariosas proximais julgadas em dentina pelo ICDAS isoladamente e aproximadamente quadruplicou o número daquelas assim classificadas pela avaliação radiográfica em permanentes. / The aim of this in vivo study was to assess the ICDAS visual method, combined ICDAS/fiber optic transillumination and bite wing radiographs. A total of 2,279 pits and fissures in upper incisors, pre-molars and molars permanent surfaces and 272 primary molars surfaces in 72 patients (aged 8 to 18 years-old) were assessed by an trained examiner. The seven scores for coronal primary caries detection criteria from ICDAS visual criteria were applied. Two fiber optic transillumination devices were assessed: FOTI Schott, SCH, tip diameter 0,5 mm and FOTI Microlux, MIC, portable device, tip diameter 3 mm. During the FOTI/ICDAS combined exam, the fiber optic was used to illuminate and also to transilluminate the surface that was being evaluated. The radiograph examination (RX) was done by bite-wings for posterior teeth and periapical for anterior teeth. Examinations were performed using dental chair after supervised toothbrushing. In the first exam day, the visual exam using ICDAS was done followed by ICDAS combined to MIC or SCH. After that the radiograph exam was done. After one week, the ICDAS was done again followed by the FOTI that was not used the week before. The exams were repeated in 10 patients after, at least, one week of interval to evaluate the intra-examiner reproducibility , presenting weighted kappa values 0.95 (ICDAS), 0.94 (MIC), 0.95 (SCH) and 0.99 (RX). In permanent pits and fissures surfaces, RX deemed a greater number of surfaces presenting dentin lesions (53) than the other methods (34 to 36). However no enamel lesion was detected which were identified by ICDAS (94),SCH (107) and MIC (91). For permanent approximal surfaces, the fiber optic transillumination identified a greater number of approximal surfaces as having enamel lesions - 150 (SCH) and 139(MIC) - than visual exam (106), while RX identified only 43. For primary occlusal surfaces, the four methods deemed a similar number of surfaces without lesion (52 to 59) or with dentin lesion (21 to 26), the same for approximal dentin lesion (31 to 36). However a reduced number of primary approximal lesions were deemed by the RX (3) compared to the other methods (15 to 16). Im primary dentition, the ICDAS and FOTI combined to visual exam deemed a great number of enamel approximal lesions compared to RX, where a similar number of dentin lesions were classified by the four methods in primary occlusal and approximal surfaces. In permanent pitts and fissures, for ICDAS and FOTI/ICDAS combined, presented similarity in surfaces deemed as having enamel lesions or dentin lesions, while the radiograph exam classified a great number as having dentin lesion and no enamel lesion. Adding fiber optic transillumination to visual exam increased in one third approximal lesions deemed in dentin by the ICDAS alone and made fourfold the number of those as classified by permanent radiograph evaluation.

Made available in DSpace on 2014-08-20T13:33:00Z (GMT). No. of bitstreams: 1 tese_marcelo_mendonca.PDF: 4204978 bytes, checksum: e41a9490cdb350a5e7add8e129afdd82 (MD5) Previous issue date: 2011-12-01 / The conventional methods used to detect the Listeria monocytogenes in foods are laborious and expensive, requiring several days for final identification. Monoclonal antibody (MAb) based immunoassays are highly specific and rapid to perform, especially when MAbs are raised to conserved virulence factors in the pathogen. Among diverse virulence factors of L. monocytogenes, the surface protein internalin A (InlA) is one of the most well-known and characterized protein, being an excellent target as it is highly exposed on the surface and exclusive of pathogenic species. In this work we report the production, characterization and use of a panel of MAbs against InlA (2D12, 3B7, 4E4), and a MAb (3F8) which specifically recognizes all bacteria belonging the genus Listeria. MAbs were produced by the immunization of BALB/c mice with a recombinant InlA together with heat killed L. monocytogenes. The MAbs produced showed excellent reativities by indirect ELISA, Western blot and immunofluorescence. A Cy5 conjugated anti-InlA MAb-2D12 was used as detection antibody for L. monocytogenes in a sandwich-like fiber optic immunoassay. Using MAb-2D12 as capture antibody on the waveguides, the limit of detection was ~3 x 102 CFU.mL-1, and when MAb-3F8 was used for capture the limit of detection was ~1 x 105 CFU.mL-1. Furthermore, MAbs 2D12 and 3F8 were used to coat paramagnetic beads and tested in the immunomagnetic separation (IMS) of L. monocytogenes from pure cultures, and artificially contaminated cheeses and hotdogs. After IMS capture, bacteria were released from the beads, used in the fiber optic assay or plated on agar for counting. In parallel, the capture of L. monocytogenes was confirmed by real-time qPCR and light-scattering technology (BARDOT). Using IMS to concentrate and separate L. monocytogenes, followed by a fiber optic platform, it was possible to detect in less than 22 h, approximately 40 CFU/g of L. monocytogenesi, even in the presence of L. innocua in cheese and hot dogs artificially contaminated. In addition, using mass spectrometry (MALDI-TOF-MS) the protein to which MAb-3F8 binds, was identified as fructose 1,6-bisphosphate aldolase (FBA). The results presented in this work indicate that using both systems together, the IMS and fiber optic immunosensor, were more reliable and faster, and could be applied in the routinely for detection of L. monocytogenes in food. Moreover, both MAbs have the potential to useful in others biosensor platforms, as well as in other detection and functionality immunoassays for InlA and FBA in Listeria. / Os métodos convencionais empregados para detecção de Listeria monocytogenes em alimentos são laboriosos e onerosos, requerendo vários dias para sua identificação final. A utilização de anticorpos monoclonais (MAbs) em imunoensaios para detecção rápida de bactérias tem como vantagem a alta especificidade e rapidez, principalmente quando direcionados para fatores de virulência conservados. Dentre os diversos fatores de virulência de Listeria, a proteína de membrana internalina A (InlA), é umas das mais bem caracterizadas, sendo um excelente alvo por ser altamente exposta na superfície e exclusiva de espécies patogênicas. Neste trabalho é relatado a produção, caracterização e utilização em métodos de diagnósticos de um painel de MAbs contra a InlA (2D12, 3B7, 4E4), e de um MAb (3F8) que reconhece especificamente todas as bactérias do gênero Listeria. Na produção dos MAbs, camundongos BALB/c foram imunizados com uma proteína recombinante InlA (rInlA) concomitantemente com L. monocytogenes inativadas por fervura. Os MAbs gerados demonstraram excelente reatividade por ELISA indireto, Western blot e imunofluorescência. O MAb anti-InlA 2D12 marcado com Cy5 foi usado como anticorpo de detecção de L. monocytogenes, no sistema tipo sanduíche de sensor de fibra óptica. Usando MAb-2D12 como anticorpo de captura nas fibras ópticas, obteve-se um limite de detecção de ~3 x 102 CFU.mL-1, e um limite de detecção de ~1 x 105 CFU.mL-1 foi visualizado com MAb-3F8 como captura. Os MAbs anti-InlA 2D12 e anti-Listeria 3F8 foram posteriormente utilizados para sensibilizar esferas paramagnéticas e testados na separação imunomagnética (IMS) de L. monocytogenes em culturas puras, e em queijo e salsichas tipo hotdog artificialmente contaminados. Após a captura por IMS, as bactérias foram liberadas, incubadas com a fibra óptica ou plaqueadas em agares para contagem. Em paralelo, a confirmação da captura de L. monocytogenes foi realizada por PCR quantitativo em tempo real e por light-scattering technology (BARDOT). Utilizando IMS para separar e concentrar L. monocytogenes, seguido da utilização em plataforma de fibra óptica, foi possível realizar a detecção em menos de 22 horas, de aproximadamente 40 UFC/g de L. monocytogenes em presença de L. innocua, em queijo e salsicha artificialmente contaminados. Além disso, a proteína alvo do MAb3F8 foi identificado como frutose 1,6-bifosfato aldolase através de espectrometria de massa (MALDI-TOF-MS). Os resultados obtidos nesse trabalho indicam que a utilização em conjunto dos sistemas de IMS e fibra óptica com os MAb-2D12 e MAb3F8, foram confiáveis e rápidos, e assim, podendo ser empregados em imunoensaios de rotina para detecção de L. monocytogenes em alimentos. Contudo, ambos MAbs possuem ainda grande potencial para serem mais explorados em outras plataformas de biossensores, assim como, em outros imunoensaios de detecção e funcionalidade de InlA e FBA em Listeria

In der medizinischen Diagnostik, Bioverfahrenstechnik und Umwelttechnik besteht ein steigender Bedarf an kompakten Analysegeräten für die schnelle Vor-Ort-Detektion spezifischer biochemischer Substanzen. Im Rahmen der Arbeit wurde daher ein neuartiger faseroptischer Sensor entwickelt, der in der Lage ist kleinste Brechzahländerungen, z.B. durch molekulare Bindungsprozesse, zu detektieren. Die hohe Empfindlichkeit an der vergoldeten Spitze der Sensorfaser beruht auf der Oberflächenplasmonenresonanz (SPR) einer einzelnen Mantelmode, die durch ein langperiodisches Fasergitter (LPG) ermöglicht wird. Die Übertragungsfunktion des Sensors wurde unter Verwendung eines Schichtwellenleitermodells schnell und präzise modelliert. Es konnte gezeigt werden, dass in einem wässrigen Umgebungsmedium die höchste Empfindlichkeit im Spektralbereich um 660 nm unter Annahme einer rund 35~nm dicken und 2~mm langen Goldbeschichtung erreicht wird. Weiterhin wurde nachgewiesen, dass mit einer intermediale Schicht aus Cadmiumsulfid die SPR der Mantelmode in einen höheren Spektralbereich verschoben und damit die Empfindlichkeit deutlich verbessert werden kann. Um eine geringe Polarisationsabhängigkeit des Sensors sicherzustellen, wurde ein nasschemisches Abscheidungsverfahren für die allseitige Goldbeschichtung der Sensorfaser entwickelt. Die spezifischen optischen Eigenschaften dieser Abscheidungen wurden mit Hilfe von LPGs untersucht, die durch eine spezielle UV-Belichtung hergestellt wurden. Die Experimente ergaben, dass die komplexe Permittivität nasschemischer Abscheidungen mit Schichtdicken oberhalb von 50~nm mit aufgedampften Goldschichten vergleichbar ist. Die Verluste der adressierten Mantelmoden wurden mit einer äquivalenten Sensoranordnung aus zwei identischen LPG untersucht. Dabei konnte ein Skalierfaktor abgeleitet werden, der die effiziente Berechnung der Mantelmodendämpfung erlaubt. Es wurde nachgewiesen, dass die Brechzahlauflösung etablierter volumenoptischer SPR-Sensoren mit einer einfachen Transmissionsmessung an einer geeigneten Wellenlänge erreicht werden kann. Die äußerst kompakte Sensorfläche des faseroptischen Sensors ermöglicht darüber hinaus die Untersuchung deutlich kleinerer Probenvolumina ohne ein zusätzliches mikrofluidisches System zu benötigen. Es wurde gezeigt, dass sekundäre Brechzahländerungen aufgrund von Temperaturschwankungen oder unspezifische Ablagerungen durch eine differentielle Auswertung zweier identischer Sensoren kompensiert werden können. Die verbleibende Querempfindlichkeit wird durch die Polarisationsabhängigkeit der Sensoren bestimmt. Die geringste Querempfindlichkeit konnte daher mit einer homogenen nasschemischen abgeschiedenen Sensorfläche nachgewiesen werden. / Compact analysis devices which facilitate the rapid detection of specific biochemical substances are in increasing demand in the fields of point-of-care medical diagnostics, bioprocess engineering and environmental engineering. The aim of this work was therefore to design a novel fiber-optic sensor able to detect small refractive index changes such as those caused by molecular binding processes. The high level of sensitivity at the gold-plated tip of the sensor fiber stems from the surface plasmon resonance (SPR) of a single cladding mode, which is the result of a long-period fiber grating (LPG). The transfer function of the sensor was calculated quickly and accurately using a slab waveguide model. It was observed that the highest level of sensitivity in an aqueous ambient medium is achieved at a wavelength of 660 nm assuming a gold coating of 35 nm in thickness and 2 mm in length. Furthermore, it was demonstrated that an intermedial cadmium sulfide layer shifts the SPR of the cladding mode towards higher wavelengths, thus leading to significantly enhanced sensitivity. An electroless plating process for the omnidirectional deposition of gold on the sensor fiber was developed in order to minimize the sensor\'s dependency on polarization. The specific optical properties of the gold layer deposited were investigated with the aid of LPGs fabricated using a special UV exposure method. The experiments showed the complex permittivity of electroless platings with a thickness of over 50 nm to be comparable with that of evaporated gold layers. The losses of the addressed cladding modes were investigated using an equivalent sensor setup consisting of two identical LPGs. This facilitated the determination of a scaling factor enabling the effcient calculation of cladding mode attenuation. It was demonstrated that it is possible to obtain the refractive index resolution of established volume optical SPR sensors with the aid of simple transmission measurements at a specific wavelength. Moreover, the extremely compact sensing area of the fiber-optic sensor enables the investigation of smaller sample volumes without the need for an additional microfluidic system. Secondary refractive index changes caused by temperature fluctuations or unspecific binding events can be compensated for by means of the differential interrogation of two identical fiber-optic sensors. The residual cross sensitivity is determined by the polarisation dependency of the sensor. The lowest cross sensitivity was therefore demonstrated in combination with a homogeneous electroless plated sensor surface.

The pursuit for improved engine efficiency is driving the demand for accurate temperature measurement inside turbine engines. Accurate measurement can allow engines to be operated closer to their design limits to improve thermal efficiency. It can enable engineers to verify mechanical integrity, provide better prediction of component life, validate CFD and other design tools and aid the development for leaner more efficient engines. Unfortunately, experimentally measuring surface temperatures under harsh rotating conditions is challenging. This EngD study conducted by Ashiq Hussain Khalid at the University of Manchester and Rolls-Royce plc, reviews the rationale of using phosphor thermometry over existing methods, including thermocouples, pyrometry and thermal paints/melts, which lack detail, accuracy, or are too expensive for continuous testing. Although phosphor thermometry exhibits desirable characteristics, the high temperature and fast rotating engine environment presents some challenges that would need to be addressed before a successful measurement system can be implemented. Examples of such issues include: rising blackbody radiation, restricted optical access, fibre optic constraints and limited time period to collect data. These factors will impose measurement limits and greatly influence the design philosophy of the system, including phosphor choice, phosphor lifetime characteristics, bonding technique, excitation/detection methodologies and probe design. Taking these into consideration, the research focuses on the development of phosphor thermometry systems for use in development gas turbine engines, with measurement solutions for specific engine components. The high pressure turbine blade was given research priority. A number of phosphors including YAG:Tb, YAG:Tm. Y2O3:Eu and Mg3F2GeO4:Mn were investigated and characterised in terms of intensity and lifetime decay, with increasing temperature up to 1500oC. Spectral analysis and absolute intensity measurements established emission peaks and permitted comparative quantitative analysis to optimise system setup. The intensity of phosphor emission relative to Planck's blackbody radiation was also performed. YAG:Tm under 355nm illumination was found to exhibit the highest emission intensity at high temperatures, and because its spectral emission peak at 458nm was the lowest, its advantage in terms of blackbody radiation was further amplified. For rotating components, an upper temperature limit is reached based on the emission intensity at rising blackbody radiation levels and the system's ability to detect fast decays. A lower limit is reached based on the quenching temperature, probe design and rotational velocity. There are different methods to correct the distorted decay waveform as it traverses through the acceptance cone of the fibre. A phosphor selection criterion, taking into consideration these limitations, was successfully applied for various rotating engine components. The optical layout was setup and tested on stationary and rotating cases under laboratory conditions using similar design constraints, including fibre choice, maximum permissible lens size and target distances. A series of tests validated design methodologies and assumptions to enable testing on full scale rotating engine components. Mg3F2GeO4:Mn, using 355nm illumination, was found to be the most suitable phosphor for the HP drive cone. The estimated performance under the expected rotational speeds was found to be 624-812°C with a standard uncertainty of ±0.99%. YAG:Tm, illuminated with 355nm, was found to be the most promising phosphor for high pressure turbine blade measurements. The performance under the expected rotational speeds was found to be 1117-1375°C with a standard uncertainty of ±0.97%. This is better than other competing technologies that are currently available for temperature measurement of rotating turbine blades.

Il a été montré que la cavitation acoustique pouvait se révéler utile dans l'administration de médicaments pour de nombreuses applications biologiques et médicales. Cette thèse commence par une présentation de la cavitation ultrasonore et des mécanismes d'action mis en jeu pour la délivrance de médicaments. A la fin de ce cette synthèse, un dispositif à deux transducteurs ultrasonores disposés de manière confocale est présenté pour résoudre certains des problèmes actuels dans le domaine. Il est ensuite mis en oeuvre dans différentes études de faisabilité. La thèse est organisée en 5 chapitres : 1. L'utilisation de la cavitation acoustique dans un contexte biomédical est présentée ici dans une revue générale. Ce chapitre comprend l'état de l'art pour la génération de cavitation, les techniques expérimentales qui sont actuellement mises en oeuvre pour la mesure de la cavitation, et les approches cliniques et précliniques pour l'utilisation de la cavitation in vivo pour différents types de tissu biologique. 2. Le dispositif ultrasonore utilisé pour toutes les études de cette thèse est ensuite décrit. Il est caractérisé acoustiquement et comparé avec un simple transducteur dans le but de démontrer son efficacité pour la génération de la cavitation. Cette comparaison est d'abord faite par une quantification chimique du niveau de cavitation. A puissance constante, le dispositif à deux transducteurs confocaux est bien plus efficace pour générer de la cavitation. Les causes de cette observation, notamment la réduction de la propagation non-linéaire et la stabilisation du nuage des bulles par les forces Bjerknes, sont ensuite étudiées par des mesures acoustiques, des simulations de pression en régime linéaire et un suivi par une caméra ultra rapide des nuages de bulles induits. 3. Le prototype confocal est utilisé in vivo sur des tumeurs sous cutanées en conjonction avec des liposomes. Dans un premier temps, des essais sous IRM démontrent la possibilité de larguer le contenu des liposomes localement par la cavitation inertielle délivrée par le dispositif. Une seconde étude avec une formulation liposomale de doxorubicine a permis de démontrer l'amélioration de la réponse thérapeutique de la chimiothérapie après application de la cavitation inertielle.. 4. Une étude de faisabilité de l'interférence de l'ARN (RNAi) sur un petit nombre d'animaux est réalisée avec le dispositif confocal et des molécules de siRNA encapsulées dans des liposomes Les expériences sont conduites in vivo avec une xénogreffe de tumeur de sein humain. Après une phase de réglage des paramètres ultrasonores pour limiter la toxicité du traitement, on observe une inhibition significative du gène ciblé. 5. Une deuxième étude de faisabilité est réalisée pour étudier la potentialisation de la chimiothérapie avec l'évérolimus dans un modèle de chondrosarcome de rat. Les traitements ultrasonores et les chimiothérapies sont répétés. Sur un petit nombre d'animaux, on montre l'innocuité du traitement ultrasonore, et l'efficacité en conjonction avec l'agent anti tumoraux, évérolimus / Acoustic cavitation has been shown to be a useful tool in drug delivery for many different biological tissues and indications, and this thesis aims to contribute to the knowledge of cavitation from a drug delivery perspective. This thesis seeks to synthesize the current knowledge and practice concerning acoustic cavitation in a biomedical context, and to present a high intensity confocal ultrasound (US) prototype to address some of the current problems in the field and to give a proof of concept for the therapeutic efficacy of such a prototype. The thesis is organized in 5 chapters: 1. The use of acoustic cavitation in a biomedical context is presented here in a general review. This review comprises the state of the art for cavitation generation, experimental techniques currently being implemented for the measurement of cavitation, and the clinical and preclinical approaches to the use of cavitation in vivo on a tissue by tissue basis. 2. The high intensity confocal US prototype used for all studies in this thesis is presented here. It is characterized in terms of the advantages it gives for the generation of cavitation. Enhancement of cavitation is first demonstrated chemometrically with a fluorescent dosimeter compared to a single transducer at the ultrasonic focus. The mechanisms for cavitation enhancement are then investigated with acoustic measurements, linear pressure simulations, and high speed camera data. 3. The confocal US prototype in used in conjunction with a liposomal formulation of doxorubicin is performed in which a therapeutic enhancement of tumor inhibition is presented. The mechanism of this enhancement is investigated with liposomally encapsulated lanthanide contrast agents and magnetic resonance imaging. 4. A small scale proof of concept for the use of RNA interference using the confocal prototype, and liposomally encapsulated siRNA molecules. The experiments are performed In vivo with a xenograft of human breast tumor. This study also includes data for the safety of the US exposure on a mouse treated one time. 5. Another small scale proof of concept of the use of the confocal device on potentiating chemotherapy with the drug everolimus in a rat chondrosarcoma model. The studies presented here also investigate the use of multiple US exposures on the same tumor in a combined drug / US treatment regimen

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Sensors have become essential elements in human life for safe and comfortable existence in the ever demanding world. Various technologies over decades have contributed in their own way fulfilling innumerable sensing requirements. The discovery of optical sensor technologies has revolutionized the sensing field due to their inherent advantages. Among the large number of fiber optic sensor technologies, FBG based sensors have become widely known and popular within and outside the photonics community and has seen a prominent rise in their utilization. This thesis explores the use of FBG sensors for a wide range of applications scanning across a variety of engineering and medical applications, in the areas of civil engineering, biomechanical engineering, aerospace engineering, geoengineering, etc. It also deals with newer methods of packaging FBG sensors for the measurement of specific engineering parameters like strain, temperature, pressure, displacement and vibration. In the field of civil engineering, FBG sensors are employed for strain sensing on a prism and furthermore tested on a full size brick wallet. During this study, emphasis is made on substituting traditional sensors by specially packaged FBG sensors with the intent of either enhancing the sensing system’s performance or in merging/uniting the inherent advantages of FBG sensors. In the area of biomechanics, a novel sensor methodology using FBG sensors, for measuring surface strains generated on the skin of the calf muscle during various leg exercises is proposed. This methodology is used to address one of the most critical and life threatening issues in long distance air travel, namely the Deep Vein Thrombosis. Further, a FBG sensor based plantar sensing plate, is designed and developed, to measure plantar strain distribution in foot and also to analyze the postural stability. In the field of aerospace engineering, FBG sensors are used for addressing two of the most vital issues; Structural Health Monitoring (SHM) and direct measurement of pressure and temperature on the surface of an aircraft under hypersonic wind flow. Carbon Fiber Composite coupon level testing is carried out to obtain a generic strain calibration factor for the FBG sensor. Further, FBG sensors are exploited for the direct measurement of absolute temperature and pressure on the leeward surface of blunt cone at hypersonic wind speeds. In the domain of geoengineering, the feasibility studies have been undertaken to use a FBG as a seismic sensor and as a bore-well characterizing sensor. A novel FBG seismic sensor package is developed using a single FBG sensor to pick up the seismic waves propagating through the ground generated from earthquakes and ground tremors. Further, FBG sensors are used for measurement of temperature profiles in a bore-well to delineate and characterize the behavior of fractures during seasonal climatic changes. To summarize, the present thesis demonstrates a comprehensive experimental study which bring out the utility of FBG sensors in a variety of challenging applications.