L’imagerie préclinique est devenue une ressource incontournable pour l’évaluation de paramètres physiopathologiques, pour le suivi du développement tumoral ainsi que pour le développement de thérapies anticancéreuses. Les évolutions technologiques apparues ces dernières années ont conduit au développement de nouvelles modalités d’imagerie ayant un fort potentiel de translation vers la clinique. Ce manuscrit présente diverses approches par imagerie échographique, photoacoustique et de fluorescence dans le proche infrarouge pour le suivi de la pathologie cancéreuse. Dans un premier temps, nous nous sommes intéressés à la caractérisation de l’hypoxie et son suivi au cours du temps dans différents modèles de cancers humains. Différentes stratégies d’imagerie multimodale ont ensuite été mises en oeuvre pour évaluer l’efficacité d’une nouvelle prodrogue thérapeutique permettant la libération d’une molécule active dans le proche environnement tumoral sur des modèles humains de tumeurs pancréatiques, mammaires, pulmonaires. Enfin, dans un contexte de recherche translationnelle, nous avons exploré le potentiel de l’imagerie photoacoustique et de la fluorescence infrarouge pour la mise en évidence de l’invasion ganglionnaire tumorale en mettant en oeuvre des modèles de ganglions sentinelles minimalement envahis. Au cours de ce travail, nous avons montré l’intérêt du suivi de l’hypoxie tumorale en onco-pharmacologie et mis en évidence le fort potentiel de l’imagerie PA pour les approches translationnelles en oncologie. La principale limitation correspond à la profondeur relativement faible des régions explorables, mais ce point suscite actuellement de nombreux développements technologiques. Les études de faisabilité réalisées ainsi que la validation de protocoles de preuves de concept permettront l’exploitation en routine de ces nouvelles modalités d’imagerie. / Preclinical imaging has become an unavoidable step for pathophysiological parameters assessments, for the follow up of tumor growth and for the anticancer therapies development. Technological improvements have emerged in recent years, allowing the emergence of new imaging modalities with a high potential for translation into clinical practice. This manuscript presents several approaches by ultrasound imaging, photoacoustics and near infrared fluorescence in order to monitor the cancer pathology. Initially, we focused on the characterization of hypoxia and its longitudinal assessment in various preclinical models of human cancers. Various multimodal imaging strategies were implemented to assess the efficacy of a new therapeutic prodrug allowing the release of an active molecule in the tumor microenvironment on human models of pancreatic, breast and lung tumors. Finally, in a context of translational research, we explored the potential of photoacoustic and near infrared fluorescence imaging to highlight the lymph node invasion by cancer cells implementing minimally invaded sentinel lymph node models. In this work, we have shown the interest in monitoring the tumor hypoxia in onco-pharmacology and highlighted the high potential of photoacoustic imaging for oncology translational approaches. The main limitation is the relatively shallow depth of regions that we can explore, but this point is currently subject to many technological developments. Feasibility studies performed and validation of proof of concept protocols will enable routine exploitation of these new imaging modalities.

High resolution imaging of wide fields has been a prerogative of space telescopes for decades. Multi-conjugate adaptive optics (MCAO) is a key technology for the future of ground-based astronomy, especially as we approach the era of ELTs, where the large apertures will provide diffraction limits that will significantly surpass even the James Webb Space Telescope. NFIRAOS will be the first light MCAO system for the Thirty Meter Telescope and to support its development I have worked on HeNOS, its test bench integrated in Victoria at NRC Herzberg. I have aligned the optics, tested the electronic hardware, calibrated the subsystems (cameras, deformable mirrors, light sources, etc.) and characterized the system parameters. Development and support for future MCAO instruments also involves data analysis, a critical process in delivering the expected performance of any scientific instrument. To develop a strategy for optimal stellar photometry with MCAO, I have observed the Galactic globular cluster NGC 1851 with GeMS, the MCAO system on the 8-meter Gemini South telescope. From near-infrared images of this target in two bands, I have found the optimal parameters to employ in the profile-fitting photometry and calibration. As testimony to the precision of the results, I have obtained the deepest near-infrared photometry of a crowded field from the ground and used it to determine the age of the cluster with a method recently proposed that exploits the bend in the lower main sequence. The precise color-magnitude diagram also allows us to clearly observe the double subgiant branch for the first time from the ground, caused by the multiple stellar populations in the cluster. As the only facility MCAO system, GeMS is an important instrument that serves to illuminate the challenges of obtaining accurate photometry using such a system. By coupling the knowledge acquired from an instrument already on-sky with experiments in the lab on a prototype of a future system, I have addressed new challenges in photometry and astrometry, like the promising technique of point spread function reconstruction. This thesis informs the development of appropriate data processing techniques and observing strategies to ensure the ELTs deliver their full scientific promise over extended fields of view. / Graduate

Master of Science / Department of Kinesiology / Thomas J. Barstow / Limb blood flow increases linearly with exercise intensity; however, invasive measurements of microvascular muscle blood flow during incremental exercise have demonstrated submaximal plateaus. Diffuse correlation spectroscopy (DCS) noninvasively quantifies relative changes in microvascular blood flow at rest via a blood flow index (BFI). The purpose of this study was to quantify relative changes in tissue blood flow during exercise using DCS, compare the BFI of the flexor digitorum superficialis (BFI[subscript]FDS) muscle to brachial artery blood flow (Q̇[subscript]BA) measured via Doppler ultrasound, and employ near infrared spectroscopy (NIRS) alongside DCS to simultaneously measure perfusive and diffusive oxygen transport within a single volume of exercising skeletal muscle tissue. We hypothesized Q̇[subscript]BA would increase with increasing exercise intensity until task failure, BFI[subscript]FDS would plateau at a submaximal work rate, and muscle oxygenation characteristics (total-[heme], deoxy-[heme], and % saturation) measured with NIRS would demonstrate a plateau at a similar work rate as BFI[subscript]FDS. Sixteen subjects (23.3 ± 3.9 yrs; 170.8 ± 1.9 cm; 72.8 ± 3.4 kg) participated in this study. Peak power (P[subscript]peak) was determined for each subject (6.2 ± 1.4W) via an incremental handgrip exercise test to task failure. Measurements of Q̇[subscript]BA, BFI[subscript]FDS, total-[heme], deoxy-[heme], and % saturation were made during each stage of the incremental exercise test. Q̇[subscript]BA increased with exercise intensity until the final work rate transition (p < 0.05). No increases in BFI[subscript]FDS or muscle oxygenation characteristics were observed at exercise intensities greater than 51.5 ± 22.9% of P[subscript]peak and were measured simultaneously in a single volume of exercising skeletal muscle tissue. Differences in muscle recruitment amongst muscles of the whole limb may explain the discrepancies observed in Q̇[subscript]BA and BFI[subscript]FDS responses during incremental exercise and should be further investigated.

Cyanine dyes are attractive photosensitizers for photodynamic therapy due to their ease of structure modification and intense absorption in the near-infrared range. Photosensitizers that can bind to DNA and absorb at long enough wavelengths of light to deeply penetrate biological tissue are in high demand for treatment of cancer and other diseases. The following study analyzes the DNA interactions of three pentamethine cyanine dyes with very similar structures, all of which absorb light at wavelengths longer than 800 nm. The work described involves an extensive study of the photocleavage abilities and DNA binding characteristics of these dyes. Our lead compound was a bromophenyl meso substituted symmetrical quinoline cyanine dye. Spectroscopic data, gel electrophoresis experiments and other studies were used to provide evidence of DNA binding mode, ROS production, and of dye-sensitized DNA photocleavage at the unprecedented wavelength of 850 nm.

Doctor of Philosophy / Department of Anatomy and Physiology / Thomas J. Barstow / The interaction between dynamic muscle contractions and the associated muscle blood flow is very intriguing leading to questions regarding the net effect of these contractions on oxygen delivery and utilization by the working muscle. Study 1 examined the impact of contractions on muscle blood flow at the level of the femoral artery. We demonstrated that muscle contractions had either a facilitory, neutral, or net impedance effect during upright knee extension exercise as intensity increased from very light to ~70% peak work rate. This led to the question of what impact a change in contraction frequency might have on the coupling of blood flow to metabolic rate during cycling exercise. The blood flow/VO2 relationship has been shown to be linear and robust at both the central (i.e., cardiac output/pulmonary VO2) and peripheral (leg blood flow/leg VO2) levels. However, an increase in contraction frequency has been reported to either decrease, have no effect, or increase the blood flow response during exercise. Study 2 determined if the steady state coupling between muscle blood flow and metabolic rate (centrally and/or peripherally) would be altered by varying contraction frequency. Our results indicate that both central and peripheral blood flow/VO2 relationships are robust and remain tightly coupled regardless of changes in contraction frequency. Study 3 examined muscle microvascular hemoglobin concentration and oxygenation within the contraction/relaxation cycle to determine if microvascular RBC volume was preserved and if oxygen extraction occurred during contractions. We concluded that microvascular RBC volume was preserved during muscle contractions (i.e., RBCs remained in the capillaries), which could facilitate continued oxygen delivery. Further, there was a cyclic pattern of deoxygenation/oxygenation that corresponded with the contraction/relaxation phases of the contraction cycle, with deoxyhemoglobin increasing significantly during the contractile phase. These data suggest that oxygen extraction continues to occur during muscle contractions. Significant insight has been gained on the impact of muscle contractions on oxygen delivery to and exchange in active skeletal muscle. This series of studies forms a base of knowledge that furthers our understanding of the mechanisms which govern the control of skeletal muscle blood flow and its coupling to muscle metabolic rate.

Plasmon resonance associated with nanoparticles of gold can enable photothermal ablation of tissues or controlled drug release with exquisite temporal and spatial control. These technologies may support many applications of precision medicine. However, clinical implementations of these technologies will require new methods of intraoperative imaging and guidance. Near-infrared laser surgery is a prime example that relies on improved image guidance. Here we set forth applications of augmented microscopy in guiding surgical procedures employing plasmon resonant gold-coated liposomes. Absorption of near-infrared laser light is the first step in activation of various diagnostic and therapeutic functions of these novel functional nanoparticles. Therefore, we demonstrate examples of near-infrared visualization of the laser beam and gold-coated liposomes. The augmented microscope proves to be a promisingimage guidance platform for a range of image-guided medical procedures.

This dissertation develops an innovative approach towards less-constrained iris biometrics. Two major contributions are made in this research endeavor: (1) Designed an award-winning segmentation algorithm in the less-constrained environment where image acquisition is made of subjects on the move and taken under visible lighting conditions, and (2) Developed a pioneering iris biometrics method coupling segmentation and recognition of the iris based on video of moving persons under different acquisitions scenarios. The first part of the dissertation introduces a robust and fast segmentation approach using still images contained in the UBIRIS (version 2) noisy iris database. The results show accuracy estimated at 98% when using 500 randomly selected images from the UBIRIS.v2 partial database, and estimated at 97% in a Noisy Iris Challenge Evaluation (NICE.I) in an international competition that involved 97 participants worldwide involving 35 countries, ranking this research group in sixth position. This accuracy is achieved with a processing speed nearing real time. The second part of this dissertation presents an innovative segmentation and recognition approach using video-based iris images. Following the segmentation stage which delineats the iris region through a novel segmentation strategy, some pioneering experiments on the recognition stage of the less-constrained video iris biometrics have been accomplished. In the video-based and less-constrained iris recognition, the test or subject iris videos/images and the enrolled iris images are acquired with different acquisition systems. In the matching step, the verification/identification result was accomplished by comparing the similarity distance of encoded signature from test images with each of the signature dataset from the enrolled iris images. With the improvements gained, the results proved to be highly accurate under the unconstrained environment which is more challenging. This has led to a false acceptance rate (FAR) of 0% and a false rejection rate (FRR) of 17.64% for 85 tested users with 305 test images from the video, which shows great promise and high practical implications for iris biometrics research and system design.

In the manufacturing process of float glass often atmospheric pressure chemical vapour deposition (APCVD) reactors are integrated on-line for the deposition of functional thin solid films. Such functional films have applications in architectural glass, flat panel displays and solar cells. As glass moves downstream in the process, the thin film is deposited at temperatures between 500 to 700°C. The high temperatures make it difficult to monitor the deposition process and thin film quality control is commonly done at the end of the line or at lower temperatures. A time delay therefore exists between the point of thin film deposition and subsequent quality control, which can lead to large quantities of defective product being produced before faults are detected. It is therefore desirable to monitor in the APCVD reactor for rapid feedback of unexpected deviations from desired process conditions, reaction progress and fault detection. High uniformity of film properties across the substrate are important, but APCVD reactors are often empirically designed and the detailed chemical reaction mechanism is unknown. This leads to inefficient gas flow patterns and precursor utilization as well as difficulties in the design of new reactors. The APCVD deposition of tin oxide from the mono-butyl-tin tri-chloride (MBTC) is an example of such a process. Optical monitoring instruments in-situ and in-line on the APCVD reactor provided rapid feedback about process stability and progress non-invasively. Near infrared diode laser absorption spectroscopy (NIR-LAS) monitored the concentration of the reaction species hydrogen chloride (HCl) in-situ and spatially in the coating zone. A mid-infrared grating absorption spectrometer (IR-GAS) with novel pyro-electric array detector monitored the concentration of precursor entering the coating system simultaneously. In combination these instruments provide the means for rapid process feedback. Fourier transform infrared absorption spectroscopy (FTIR) was used to investigate the unknown decomposition pathway of the precursor to find the yet unknown key tin radical that initiates film growth. Stable species forming during MBTC decomposition over a temperature range of 170 to 760°C were investigated but the tin intermediate remains unknown. Computational fluid dynamics (CFD) is routinely employed in research and industry for the numerical simulation of CVD processes in order to predict reactor flow patterns, deposition rates, chemical species distribution or temperature profiles. Two and three dimensional models with complex geometries and detailed reaction models exist. A three dimensional computational fluid dynamics (CFD) model of the used APCVD reactor was built using the Fluent CFD software. The numerical simulation included a chemical model that predicted qualitatively the chemical species distribution of hydrogen chloride in the gas phase. This was confirmed through comparison with NIR-LAS results. Design shortcomings due to inefficient flow patterns were also identified. In combination the optical tools developed provide the means for safe and efficient manufacturing of thin films in APCVD reactors. CFD simulations can be used to increase precursor utilization and film uniformity in the development of new reactor designs.

Orientador: Jarbas Jose Rodrigues Rohwedder / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-07T20:00:15Z (GMT). No. of bitstreams: 1 Chagas_IsmaelPereira_D.pdf: 2025832 bytes, checksum: 8e2e4a99a15486f48f4aae44dfd6f183 (MD5) Previous issue date: 2006 / Resumo: Neste trabalho, foi desenvolvido um fotômetro NIR portátil para determinar o teor de água em álcool combustível hidratado combustível (AEHC) e o teor de etanol (Álcool etílico anidro carburente) em gasolina. Foram realizados inicialmente estudos espectroscópicos empregando um espectrofotômetro comercial para avaliar quais as melhores regiões do espectro NIR que poderiam ser empregadas para a determinação das espécies de interesse. No desenvolvimento do instrumento foram avaliados detetores baseados em um foto resistor de PbS e um fotodiodo de InGaAs. Dentre os detectores empregados o que apresentou melhores resultados foi o detector de InGaAs. Foram construídos diversos fotômetros sendo que aqueles que apresentaram as melhores performance utilizaram filtro de interferência em 1480 nm e celas cilíndricas com caminho óptico de 2 mm e 5 mm. Para o caminho óptico de 2 mm, foi utilizada como fonte de radiação uma lâmpada de 6 watts, enquanto que para a cela com 5 mm foi utilizada uma lâmpada de tungstênio de 20 watts e uma lente colimadora. Em ambos os casos, a fonte de radiação foi pulsada a uma freqüência de 25 Hz. Como transdutores de saída do instrumento foram empregados um microcontrolador PIC acoplado à um display de cristal líquido e também dois LEDs (vermelho e verde) indicando se o combustível estava dentro ou fora da especificação. O instrumento foi avaliado com amostras comerciais de álcool combustível e gasolina. Para a determinação do teor alcoólico em álcool combustível, a resposta é linear na faixa de concentração de 88 a 98% m/m, com um erro médio de 3,6 % para um total de 30 amostras analisadas, quando comparada ao seu respectivo método de referência. Na análise de amostras de gasolina foi obtida uma resposta linear para o teor de etanol entre 20 % e 30 %, com um erro médio de 3,0% para um total de 40 amostras analisadas. A ANP considera até 4% de erro médio e desta forma o instrumento classifica corretamente 100 % das amostras / Abstract: In this work a portable Near Infrared Photometer to determine the quantity of water in alcohol fuel and the quantity of ethanol in gasoline was developed. Initially, several spectroscopy analysis using a comercial spectrophotometer was made to select the best wavelenghts to determine those fuel quality parameters. The wavelengths of 1480 nm and 1920 nm were selected after preliminary study. The instrument was evaluated using two types of detectors: a PbS photoresistive detector and a InGaAs photodiode. The detector with best performance was the InGaAs photodiode. Different prototypes were built using a interference filter working in 1480 nm and path length with 2 mm and 5 mm. With the 2 mm path length was used a 6 watt tungsten lamp as radiation source and with 5 mm path length was used a 20 watts tungten lamp. This interference filter can be used to determine water in alcohol fuel and ethanol in gasoline without any changes in the instrument. The final version of the prototype showing the best results for both determinations uses a cilindric cell with 5 mm diameter and can be employed for flow or batch measurements, radiation source of a 20 watts tungsten lamp pulsed at 25 Hz and a lens to focus the infrared radiation into the detector. The output transducers of the instrument was a PIC microcontroller with a liquid crystral display and light emission diodes (LEDs) green and red. The instrument was tested using comercial fuel alcohol and gasoline samples. In the determination of water in alcohol it was obtained a linear response in the concentration range from 98 to 88 % (m/m) and in gasoline, it was 20 % to 30 %(v/v). Thirty alcohol samples were analysed showing a standard error of 3,6 % while for the gasoline, a standard error of 3,0% for a total of 40 samples analysed was found. Considering the tolerance of 4%, recommended by the National Pretoleum Agency (ANP), the instrument can classify normal and adultered samples with confidence of 100% / Doutorado / Quimica Analitica / Doutor em Quimica

Optical imaging is an emerging technology towards non-invasive breast cancer diagnostics. In recent years, portable and patient comfortable hand-held optical imagers are developed towards two-dimensional (2D) tumor detections. However, these imagers are not capable of three-dimensional (3D) tomography because they cannot register the positional information of the hand-held probe onto the imaged tissue. A hand-held optical imager has been developed in our Optical Imaging Laboratory with 3D tomography capabilities, as demonstrated from tissue phantom studies. The overall goal of my dissertation is towards the translation of our imager to the clinical setting for 3D tomographic imaging in human breast tissues. A systematic experimental approach was designed and executed as follows: (i) fast 2D imaging, (ii) coregistered imaging, and (iii) 3D tomographic imaging studies. (i) Fast 2D imaging was initially demonstrated in tissue phantoms (1% Liposyn solution) and in vitro (minced chicken breast and 1% Liposyn). A 0.45 cm3 fluorescent target at 1:0 contrast ratio was detectable up to 2.5 cm deep. Fast 2D imaging experiments performed in vivo with healthy female subjects also detected a 0.45 cm3 fluorescent target superficially placed ~2.5 cm under the breast tissue. (ii) Coregistered imaging was automated and validated in phantoms with ~0.19 cm error in the probe’s positional information. Coregistration also improved the target depth detection to 3.5 cm, from multi-location imaging approach. Coregistered imaging was further validated in-vivo, although the error in probe’s positional information increased to ~0.9 cm (subject to soft tissue deformation and movement). (iii) Three-dimensional tomography studies were successfully demonstrated in vitro using 0.45 cm3 fluorescence targets. The feasibility of 3D tomography was demonstrated for the first time in breast tissues using the hand-held optical imager, wherein a 0.45 cm3 fluorescent target (superficially placed) was recovered along with artifacts. Diffuse optical imaging studies were performed in two breast cancer patients with invasive ductal carcinoma. The images showed greater absorption at the tumor cites (as observed from x-ray mammography, ultrasound, and/or MRI). In summary, my dissertation demonstrated the potential of a hand-held optical imager towards 2D breast tumor detection and 3D breast tomography, holding a promise for extensive clinical translational efforts.