Orientador: Cristiano de Mello Gallep / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia / Made available in DSpace on 2018-08-22T03:28:54Z (GMT). No. of bitstreams: 1 Moraes_ThiagoAlexandre_M.pdf: 12211625 bytes, checksum: 5e27e2aac5dfc12de0ee782b7b6a33bc (MD5) Previous issue date: 2013 / Resumo: A emissão fotônica ultrafraca proveniente de plântulas de trigo foi mensurada em várias séries de testes sob condições constantes, no interior de câmara escura. Grãos brasileiros também foram transportados e testados na Alemanha, em séries simultâneas realizadas paralelamente a séries conduzidas tanto no Brasil quanto na Alemanha. As plântulas em ambos os países apresentaram ritmos semicircadianos, coincidentes e em sincronia com os ritmos da variação da aceleração gravimétrica local, produzidos pelos movimentos lunissolares. São apresentadas análises matemáticas a respeito destas sincronias e coincidências. Em mais de 80% do período de testes considerados o coeficiente local de correlação de Pearson entre os dois parâmetros revelou relação significante (P>0,7). Com o uso da transformada rápida de Fourier foram evidenciadas as similaridades entre as componentes temporais de oscilação do parâmetro fotônico e as encontradas no parâmetro gravimétrico. As fases da lua e a época do ano possivelmente produzem influências relevantes no desenvolvimento das plântulas. Os resultados encontrados sustentam a hipótese de que os processos envolvidos com a emissão fotônica em plântulas de trigo sejam regulados pelos ritmos de variação gravimétrica, produzidos pelos movimentos lunissolares. A técnica de detecção de emissão fotônica espontânea se mostrou uma ferramenta inovadora e útil para estudos biofísicos e cronobiológicos / Abstract: The ultra-weak photon emission from wheat seedling was measured in several series of tests under constant conditions inside a dark chamber. Brazilian seeds were also transported and tested in Germany, with simultaneous series conducted both in Brazil and in Germany. The seedlings showed, in both countries, semi-circadian rhythms coincident and in synchrony with the rhythms of local gravimetric variations of acceleration produced by lunisolar movements. Mathematical analysis of these synchronies and coincidences are presented. The local Pearson correlation coefficient between the two parameters showed a significant relationship (P> 0.7) in more than 80% of the considered testing period. The rhythmic similarities between the biophotonic oscillation and the gravimetric parameter were done by fast Fourier transform. The phases of the moon and the time of year possibly produce relevant influences on development of seedlings. The results support the hypothesis that processes involved with biophoton emission in wheat seedlings may be regulated by variations on the gravimetric rhythms in accordance to lunisolar movements. Further studies are desirable in order to look for the physiological origin of this phenomenon. The spontaneous ultra-weak photon emission detection technique proved to be a new and useful tool for chrono-biological and biophysical studies / Mestrado / Tecnologia e Inovação / Mestre em Tecnologia

Optoelectronics in the deep-ultraviolet (DUV) regime is still a growing research field that requires significant effort to understand the material properties and optimize the device structures to realize efficient DUV devices. Aluminum gallium nitride (AlGaN) is perhaps the most studied semiconductor to replace the environmentally hazardous mercury lamps; however, the external quantum efficiency of AlGaN based DUV devices is insufficient to replace the existing old-fashioned mercury UV lamps. Despite the tunability in the bandgap of AlGaN, the excessive strain accumulation associated with increased alloying of Al in AlGaN and the poor dopant activation due to the relatively large ionization energy of the donors and acceptors are not favorable for realizing efficient DUV emitters. In addition, the crossover among the light hole, heavy hole and split-off bands in the valance band for Al-rich AlGaN suppresses the transverse-electric polarization, which further worsens the external quantum efficiency. Furthermore, for DUV photodetection, commercially available Si-photodetectors suffer from poor responsivity for wavelengths shorter than 400 nm in contrast to the visible spectrum. Hence, the-state-of-art photodetectors in the DUV regime also need a significant upgrade, particularly for high-speed applications. Firstly, we utilized the high quantum confinement in plasma-assisted MBE grown ultrathin GaN QDisks to realize DUV (λ ≈ 260 nm) emission using a binary compound (GaN) in contrast to conventionally used ternary compound (AlGaN). More importantly, we experimentally demonstrated TE-dominant DUV emission, unlike Al-rich AlGaN, illustrating a unique pathway for realizing efficient DUV vertical emitters. Secondly, inspired by the light manipulation technique practiced in nature, we presented iridocytes on giant clams (Tridacna maxima), known for their symbiotic relationship with algae as a color downconverting material for DUV photodetection. Investigating the structural and optical properties of iridocytes found in Tridacna maxima, we established a robust UV communication allowing the data transfer rate of 100 Mbit/s within the forward error correction limit for modulated 375 nm-laser diode. Using a similar matrix implemented to 375 nm-laser, with high-power UV-C LED (λ ≈ 278 nm), we could establish an optical wireless communication that could allow a data-transmission rate of tens of Mbit/s within the forward error correction limit.

Conventional bacteriological methods to establish bacterial burden and distribution in infected tissues in vivo animal models typically require extensive bacteriological procedures and therefore are time consuming. An alternative approach has been suggested to use optical markers, such as luciferases, to labeled pathogens and monitor their progress and distribution in real time. The objective of the work presented in this document was to validate the use of Biophotonic Imaging (BI) through in vitro studies as a first step toward the development of in vivo models to study infectious disease in the bovine. For example, the feasibility of detecting bioluminescent Escherichia coli (E. coli-lux) from within the different bovine reproductive tract segments was studied. Up to 17 % transference of photonic emissions (PE) was detected through the reproductive tract, suggesting that in vivo or in situ models may provide a novel approach for in real time screening of uterine infections in large farm animal models. Further in vitro research conducted toward the development of approaches for non invasive detection of lux-bacteria in bovine mastitis models demonstrated that detection through the bovine mammary gland might be limited due to tissue thickness and density. However, imaging of Staphylococcus aureus (S. aureus)-lux presence in teat-end skin wound in vitro models demonstrated promising results. Furthermore, trials demonstrated that imaging of lux-bacteria in milk samples, as means to estimate bacterial cell numbers (CFU), represent an efficient model to monitor bacterial progression in vivo mastitis models. According to these findings, the efficacy of an intramammary antimicrobial agent was evaluated in real time using S. aureus-lux in vivo mastitis models conducted in lactating dairy cows. Photonic emissions from milk samples collected from challenged quarters with S. aureus-lux resulted to be an excellent predictor of CFU, as demonstrated by the high and positive correlation (0.99; P < 0.0001) between CFU and PE. In addition, BI provided in real time information regarding spatial distribution of S. aureus-lux in infected mammary gland quarters ex vivo. Collectively, this date positions BI as novel and promising tool to improve current bacteriological methods to better understand pathogenesis of bovine mastitis infections.

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Abstract This thesis reports on studies of plasmonic nanoparticles and particularly gold nanostars as signal enhancers and contrast agents for biophotonic applications including visualisation, treatment of living cells and chemical sensing. In this thesis, the optical properties of nanoparticles of different size and morphology and their silica composites were compared. Because they are the most suitable plasmonic nanostructures, gold nanostars were utilised for optical imaging modalities such as confocal microscopy and Doppler optical coherence tomography. The ability of gold nanoparticles to enhance the signal in surface-enhanced vibrational spectroscopy, including Raman and Fourier transform infrared spectroscopy was additionally studied. Finally, various gold nanoparticles were applied for cell optoporation to increase the penetration ability of exogeneous substances. In summary, significant advantages of nanostars such as their low-toxicity, high scattering and contrast abilities, in addition to a broad, tunable, plasmon resonance wavelength range, as well as the capability to enhance the signal of analyte molecules in vibrational spectroscopy were demonstrated in this thesis. The results of this study on the effectiveness of nanostars have a broad scope of utility and open a wide perspective for their utilisation in nanobiophotonics and biomedicine. / Tiivistelmä Tämä opinnäytetyö kertoo tutkimuksista, joissa plasmoninanopartikkeleita ja erityisesti kultananotähtiä on käytetty signaalinvahvistimina biofotoniikan sovelluksissa, kuten visualisointi, elävien solujen käsittely ja kemiallinen tunnistus. Tässä työssä verrattiin eri kokoisten ja muotoisten nanopartikkeleiden ja niiden piioksidikomposiittien optisia ominaisuuksia. Sopivimpina plasmoninanorakenteina kultananotähtiä käytettiin optisiin kuvantamismenetelmiin, kuten konfokaalimikroskopiaan ja Doppler-optiseen koherenssitomografiaan. Lisäksi kuvattiin myös kultananopartikkelien kykyä parantaa pinta-aktivoidun värähtelevän spektroskopian signaalia, mukaan lukien Raman- ja Fourier-muunnos-infrapuna-spektroskopia. Lopuksi, eri kultananopartikkeleita käytettiin soluoptoporaatioon eksogeenisten aineiden läpäisevyyden lisäämiseksi. Yhteenvetona, työssä osoitettiin nanotähtien merkittävät edut, kuten matala-myrkyllisyys, suuret sironta- ja kontrastiominaisuudet, laaja plasmoniresonanssin aallonpituusalue ja sen viritettävyys, sekä kyky parantaa analyyttimolekyylien signaalia värähtelyspektroskopiassa. Niinpä tutkimustulokset nanotähtien tehokkuudesta ovat laajasti käyttökelpoisia ja ne avaavat laajan näkökulman niiden hyödyntämiseen nanobiofotoniikassa ja biolääketieteessä.

Orientador: Carlos Lenz Cesar / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-22T08:41:16Z (GMT). No. of bitstreams: 1 Thomaz_AndreAlexandrede_D.pdf: 9291787 bytes, checksum: 9554ec1cfb5b3952506ff59b61aec5f9 (MD5) Previous issue date: 2013 / Resumo: A comunidade científica concorda que há grandes chances que a próxima revolução tecnológica virá do controle dos processos biológicos. Grandes mudanças são esperadas, desde como produzimos alimentos até como combatemos as doenças. O controle dos processos biológicos nos permitirá produzir carne sintética para alimentação, produzir biocombustíveis retirando CO2 da atmosfera, produzir órgãos inteiros para transplante e combater de forma eficiente doenças como câncer, por exemplo. Está claro para o nosso grupo que para se obter esses resultados é necessário entender a biologia na sua unidade mais básica: a célula. A partir do entendimento e domínio das reações químicas que acontecem dentro da célula, e mais especificamente do controle do DNA, é que vamos conseguir atingir essas previsões e revolucionar a maneira como vivemos hoje. Com esse pensamento em mente, o objetivo dessa tese foi desenvolver uma plataforma fotônica integrada para estudos de processos celulares. Nós acreditamos que as ferramentas fotônicas são as ferramentas que preenchem todos os requisitos para os estudos de processos celulares, pois possibilitam o acompanhamento dos processos em tempo real sem causar dano as células. As técnicas presentes são: fluorescência excitada por 1 ou 2 fotons, geração de segundo ou terceiro harmônico, pinças ópticas, imagem por tempo de vida da fluorescência e "fluorescence correlation spectroscopy" (FCS). Nesta tese demonstramos como montar essa plataforma integrada e mostramos sua versatilidade com resultados em várias áreas da biologia e também para o estudo de quantum dots. / Abstract: The scientific community believes there is a great chance that the next technological revolution is coming from the control of biological processes. Great changes are expected, from the way we produce food up to the way we fight diseases. The control of biological processes will allow us to produce synthetic meat as food, to produce biofuels extracting CO2 directly from the atmosphere, to produce whole synthetic organs for transplant and to fight diseases, like cancer, in more efficient ways. It is clear to our group that in order to obtain these results it is necessary to understand biology from its most basic unity: the cell. Only from understanding and controlling chemical reactions inside a cell, and more specifically from the DNA controlling, it will be possible to achieve these predictions and cause a revolution in the way we live nowadays. Bearing these thoughts in mind, the objective of this thesis was to develop an integrated photonic platform for study of cellular processes. We believe that photonic tools are the only tools that fulfill all the requeriments for studies of cellular processes because they are capable to follow processes in real time without any damage to the cells. The techniques integrated are: 1 or 2 photon excited fluorescence, second or third harmonic generation, optical tweezers, fluorescence lifetime imaging and fluorescence correlation spectroscopy. In this thesis we demonstraded how to assemble this integrated plataform and we showed its versatility with results from different areas of biology and quantum dots. / Doutorado / Física / Doutor em Ciências

Orientador: Carlos Lenz César / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-09-01T03:43:43Z (GMT). No. of bitstreams: 1 Pelegati_VitorBianchin_D.pdf: 6822381 bytes, checksum: 86749ce34dc184aeb7ed4b4ee47d70b3 (MD5) Previous issue date: 2016 / Resumo: Técnicas de microscopias ópticas são as principais ferramentas capazes de observar células e tecidos biológicos em tempo real e com mínimo dano. Essa área foi revolucionada recentemente através das microscopias confocais de varredura a laser e as microscopias de óptica não linear, naturalmente confocais. Entre os processos não lineares temos, a fluorescência excitada por dois ou mais fótons, geração de segundo harmônico [Second Harmonic Generation - SHG] e terceiro harmônico [Third Harmonic Generation - THG]. SHG e THG são técnicas de óptica não linear coerentes, não necessitam de marcadores exógenos e permitem reconstrução de imagens em três dimensões com resolução espacial subcelular. As técnicas de fluorescência permitem visualizar estruturas específicas no espaço, mas não permitem discriminar as substâncias químicas nas estruturas celulares, e as técnicas de SHG e THG não possuem especificidade química. Espectroscopia Raman possui especificidade química através das propriedades vibracionais das moléculas e pode ser usada como mecanismo de contraste na aquisição de imagens. Comparada com a espectroscopia/microscopia infravermelho, a microscopia Raman traz a informação das vibrações moleculares do infravermelho para o visível, eliminando os problemas da baixa resolução espacial e opacidade das amostras. Entretanto a baixa sensibilidade dessa técnica implica em tempos de aquisição de imagens muito longos, da ordem de horas, inviabilizando acompanhar a dinâmica de processos celulares em tempo real. Como solução para essa baixa sensibilidade do espalhamento Raman espontâneo, surgiu a microscopia por espalhamento Raman Coerente anti-Stokes [Coherent Anti-Stokes Raman Scattering - CARS]. Comparado com Raman espontâneo, a microscopia CARS representa aumento de 4 a 5 ordens de grandeza na sensitividade da técnica, diminuindo os tempos de aquisição ao ponto de viabilizar a aquisição em taxas de vídeos (mais rápido do que 30 quadros por segundo) e estudos em tempo real. Essa tese é dedicada ao estudo experimental e teórico, assim como de algumas aplicações, das técnicas de óptica não linear, com destaque para processos de óptica não linear coerentes. Apresentamos de forma detalhada três sistemas experimentais para a aquisição de imagens de Raman coerente e um sistema integrado com várias técnicas de óptica não linear. Mostramos as primeiras imagens de CARS realizadas no Brasil. Além do CARS convencional, trabalhamos com outra técnica de CARS de ordem mais alta, o CARS cascata [cascade CARS - CCARS], e, no melhor do nosso conhecimento, apresentamos as primeiras imagens internacionais obtidas com essa metodologia. CCARS aumenta o contraste da técnica CARS, diminuindo o fundo não ressonante, um problema que aflige a comunidade científica dedicada ao uso dessa técnica. Além da diminuição do fundo não ressonante, a emissão do CCARS acontece em um comprimento de onda diferente de qualquer outro efeito não linear coerente, significando um acréscimo de complexidade mínimo para sua detecção quando comparado com o CARS. Por último mostramos algumas aplicações realizadas com o sistema experimental desenvolvido para integrar diversas modalidades ópticas em paralelo, especialmente da geração de harmônicos com a fluorescência excitada por dois fótons e suas variantes, como microscopia de tempo de vida de fluorescência (Fluorescence Lifetime Imaging ¿ FLIM) / Abstract: Optical microscopies techniques are the main tools capable of observing cell and biological tissues in real time and with minimum damage. This area have recently been revolutionized by confocal laser scanning microscopies and non-linear microscopies, naturally confocal. Among the non-linear process we have, the two or more photons excited fluorescence, second harmonic generation [SHG] and third harmonic generation [THG]. SHG and THG are coherent nonlinear techniques, they do not require exogenous markers and allow three dimension imaging reconstruction with subcellular resolution. The fluorescence techniques allow visualizing specific structures in space, but do not allow discriminating the chemical substances in cellular structures, SHG and THG techniques do not have chemical specificity. Raman spectroscopy has chemical specificity through the vibrational properties of the molecules and can be used as a contrast mechanism for imaging acquisition. Compared to infrared spectroscopy/microscopy, Raman microscopy brings information about molecular vibration from infrared to visible, eliminating the low resolution and sample opacity problems. However, this technique low sensibility implies in very long imaging acquisition times, order of hours, making it not viable for following cellular process dynamics in real time. As an answer for the spontaneous Raman scattering low sensibility, the coherent anti-Stokes Raman scattering [CARS] emerged. Compared to spontaneous Raman, CARS microscopy presents an increase of 4 to 5 orders of magnitude in the sensitivity of the technique, lowering the acquisition times to the point of making video acquisition (faster than 30 frames per second) and real time studies possible. This thesis is dedicated to the experimental and theoretical study, as well as some applications, of the non-linear techniques, with emphasis on coherent non-linear optical processes. We present in detailed form three experimental systems for the acquisition of coherent Raman images, and a system with the integration of various non-linear techniques. We show the first CARS images acquired in Brazil. In addition to conventional CARS, we worked with other higher order CARS technique, the cascade CARS [CCARS], and, in the best of our knowledge, we present the first international image acquired with this methodology. CCARS increases the contrast from CARS technique, decreasing the non-resonant background, a problem that afflicts the scientific community dedicated to the use of this technique. Besides the decrease of the non-resonant background, the CCARS emission occurs in a different wavelength from any other non-linear coherent effect, meaning a minimum complexity increase for its detection when compared with CARS. Finally we show some applications performed with the experimental system developed to integrate several optical modalities in parallel, especially the generation of harmonics with two photons excitation fluorescence and their variants such as Fluorescence Lifetime Imaging [FLIM] / Doutorado / Física / Doutor em Ciências / 830406/2010 / CAPES