This thesis studies the synthesis of diverse architectures of polymers via the reversible addition fragmentation chain transfer (RAFT) polymerisation process that is one of the most novel and versatile controlled polymerisation techniques. Star polymers, comb polymers, amphiphilic block copolymers, and random copolymers were utilised to fabricate porous films with hexagonal arrangement via a ???bottom-up??? engineering approach, namely a ???breath figure??? technique. The quality (i.e. pore regularity and pore size) of the films was optimised by controlling casting variables including humidity, airflow, concentration of polymer solution, polymer architecture, molecular weight of polymer, substrate, and casting volume. Porous membranes were chemically crosslinked to improve their mechanical strength if required. Furthermore, chemical surface modification of porous films was performed by grafting desired polymer (i.e. PNIPAAm or PAGA) via RAFT polymerisation. The RAFT groups present in the films play a role as anchoring sites for polymerisation, thus the complex initiator immobilising can be avoided in our system. The desired polymer grafting is able to enhance wettability and provide binding sites for adhesion and proliferation of cells. The topography of ungrafted and grafted films was analysed using optical microscopy, scanning electron microscopy, atomic force microscopy, confocal microscopy, ATR-FTIR, and XPS.

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 70-75).

Made available in DSpace on 2014-06-12T23:13:04Z (GMT). No. of bitstreams: 2 arquivo3128_1.pdf: 2153629 bytes, checksum: d621ae51708e16ae35bf5fa5a8be37d6 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2011 / Objetivos: Conhecer o padrão de distribuição da ventilação na caixa torácica em mulheres com diferentes padrões de obesidade, e avaliar a eficácia da técnica de Breath Stacking (BS) em mulheres com obesidade mórbida. Métodos: O estudo foi realizado em duas etapas. A primeira foi um estudo transversal com 32 mulheres obesas (IMC≥40kg/m2) e 29 mulheres com peso normal (IMC=18,5 - 24,9 kg/m2) na faixa etária entre 19 e 60 anos , dividida em grupos de acordo com a relação cintura/quadril (RCQ) em GOC-obesidade central (RCQ>0.85),n=21, GOP-obesidade periférica(RCQ≤0.85), n=11 e GC- controle, n=29. Na segunda parte, o estudo foi um ensaio clínico randomizado, cego e controlado com as mulheres obesas. Todas as voluntárias realizaram as avaliações antropométricas e cardiorrespiratórias. Para a avaliação da ventilação pulmonar foi utilizado a Pletismografia Optoeletrônica (POE) durante a respiração basal por um período de cinco minutos. Após randomizadas, as obesas formaram dois grupos: controle (GC) e intervenção Grupo Breath Stacking (GBS). Para a técnica de BS foi utilizado máscara facial com oclusão do ramo expiratório e ventilômetro de Wright. O GBS realizou três técnicas com intervalo de três minutos entre cada manobra, as imagens foram feitas por cinco minutos, antes e após as técnicas. O GC usou o mesmo circuito sem a oclusão do ramo expiratório e seguiu o mesmo protocolo de captação das imagens. Para a comparação entre os grupos foi realizado teste de análise de variância (ANOVA), com post-hoc de Bonferroni e correlação de Pearson para análise de associação entre o IMC, circunferência cintura (CC), circunferência quadril (CQ) e RCQ com as variáveis da ventilação pulmonar. Na segunda etapa, para a comparação dos grupos das variáveis antropométricas foi realizado o teste t não pareado, e para a espirometria e ventilação pulmonar antes e depois em cada grupo foi aplicado o teste t pareado. Resultados: Na primeira etapa, o GOC apresentou diferença na frequência respiratória, volume minuto (VM), tempo expiratório e nas variáveis espirométricas: VEF1 (p=0,00) e CVF (p=0,00) quando comparado ao GC. Na análise da ventilação pulmonar regional, foi encontrada nas obesas maior contribuição do volume corrente no compartimento abdominal (Vc,cab). Enquanto, no GC a maior contribuição foi no volume do compartimento torácico pulmonar (Vc,ctp). Houve correlação do Vc,ab com as variáveis antropométricas: IMC (r=+0,636;p=0,005), RCQ (r=+0,556;p=0,005) e CC (r=+0,,646;p=0,005). Na segunda etapa, o GBS apresentou aumento da contribuição do Vc,cta (p=0,04) e diminuição no Vc,ab (p=0,02), em relação aos valores absolutos do Vc nos compartimentos da caixa torácica. Antes e após a técnica o grupo GBS, não apresentou diferença nas variáveis espirométricas: VEF1(%), CVF(%), VEF1/CVF(%) e Capacidade Inspiratória (CI). Das variáveis da ventilação pulmonar a VM apresentou diminuição (p=0,03) no GBS. Conclusões: A obesidade em mulheres modifica o padrão de distribuição daventilação pulmonar total e regional em relação às mulheres de peso normal. Os dois tipos de obesidade apresentaram diferença na ventilação regional no compartimento abdominal. A obesidade central leva a padrão respiratório rápido e maior impacto na função pulmonar quanto à espirometria. Em relação ao efeito da técnica de BS houve maior contribuição no volume pulmonar na região inferior da caixa torácica. Houve uma redistribuição do volume entre os compartimentos, demonstrando a eficácia da técnica em ventilar áreas pulmonares basais

Pulmonary function testing is an important part when it comes to evaluating patients with or at risk for lung diseases. Measurement of the diffusing capacity with carbon monoxide (DLCO) of the lung is a very important parameter and reflects how well the gas exchange work. Traditionally the DLCO have been measured by the single breath (SB) method which requires a forcefully inhalation and a 10 second breath-hold. Not all patients are able to perform the method due to illness or related problems therefore it would be favourable if the ward could change to an easier method called intrabreath (IB). The IB method is not depending on a breath-holding manoeuvre, which should make it easier to perform. Eleven volunteers participated in the study. They all performed both DLCO techniques, starting with the SB followed by IB. The DLCO, when determined with the IB technique, had an excellent correlation to the SB technique. However, the IB systematically showed a lower value for DLCO, and can therefore not use the same references as SB. Before the ward can change from the SB- to the IB- method there are needs for further studies. New studies should include more volunteers so more trustworthy reference values can be made, they should also include sick patients as a check-up for the new reference values. For the moment the ward have to stay with the SB method.

Research in the field of exhaled breath analysis is developing rapidly and is currently focussed on disease diagnosis and prognosis. The ability to identify early onset of life-threatening diseases, by a subtle change in exhaled profile that is picked up through a non-invasive measure, is of clinical interest. However, implementation of exhaled breath analysis can extend further beyond disease diagnosis and/or management. Using a non-invasive and rapid sample collection with high sensitivity, breath analysis may be seen to have potential benefit to the wider community. This research describes preliminary investigations into exhaled breath in exercise-based scenarios that aims to translate current breath analysis methodologies into a sport and exercise medicine context. An adaptive absorbent-based breath sampling methodology was used to collect a total of 220 breath samples from 54 participants over 3 studies. Breath volatiles were analysed using thermal desorption-gas chromatography-mass spectrometry. Data were analysed with targeted, and multivariate metabolomics-based approaches. Potential health impacts to high performance and recreational swimmers exposed to chlorinated water was studied. Following preliminary and scoping studies, 19 participants were sampled before a 30 min swim, and a further 5 times for 10 hrs after swimming. Environmental and control samples were also collected. Concentrations of chlorine-based disinfection by-products were observed to increase by up to a median of 121-fold, and take up to 8.5 hrs to return to pre-swimming levels. Metabolomic profiling identified the monoterpene geranylacetone to be a discriminant variable in samples taken 10 hrs after swimming. Geranylacetone is associated with membranes and extracellular fluids and an upregulated trend was observed across the five sampling time points post-swimming. Further research with an appropriately stratified and powered cohort (n=38) was recommended. The effects of intense exercise on breath profiles was explored for the possible use of breath analysis for exercise science with elite performance-based medicine. Twenty-nine participants provided exhaled breath samples before undergoing a maximal oxygen uptake (fitness) test and then provided 2 additional samples over the following 1 hr period. High and low fitness groupings, deemed by oxygen uptake values, were compared for exhaled metabolites. Lower exhaled acetone and isoprene were observed in participants with greater absolute oxygen uptake leading to a hypothesis for a non-invasive breath based fitness test. Finally, an interface for breath-by-breath analysis using a transportable mass spectrometer was developed. A controlled change in exhaled profiles was achieved through the ingestion of a peppermint oil capsule. Menthone was measured on-line and monitored for up to 10 hrs post-administration. Sixteen participants enabled the system to be demonstrated as exhaled menthone was at elevated concentrations for at least 6 hrs. Validation against thermal desorption-gas chromatography-mass spectrometry confirmed the system to be detecting metabolites at the sub-μg L-1 range.

<div>Researchers have shown links between various hydrocarbons and carbonyl compounds and diseases, such as cancer using exhaled breath analysis through gas chro</div><div>matography/mass spectroscopy (GC/MS) analysis of volatile organic compounds (VOCs). Trained canines can detect these VOCs and can differentiate a patient suffering from cancer from a healthy control patient. In this project, an attempt has been made to develop highly sensitive sensors for the detection of low concentrations of aldehyde VOCs, such as nonanal, using conductive polymer composites (CPCs) and functionalized gold nanoparticles (f-GNPs). Facile methods have been used to enhance the sensitivity and cross-selectivity of the fabricated sensors towards nonanal. Interdigitated electrodes (IDEs) are fabricated through a photolithography process. Sensors of PEI/carbon black (CB) composite were developed via spin-coating of the</div><div>material followed by the heat treatment process. Sensors of 1-Mercapto-(triethyleneglycol) methyl ether functionalized GNPs are developed via drop-casting of nanomaterial and f-GNP/PEI sensors are fabricated by spin casting PEI film on top of f-GNPs. Fourier Transform Infrared (FTIR) analysis, X-Ray Diffraction (XRD) analysis, contact angle measurement, and Field Emission Scanning Electron Microscopy (FESEM) analysis was conducted to characterize the fabricated devices. The fabricated sensors have been tested with a low concentration of nonanal, nonanone, dodecane, and 1-octanol in dry air. Multiple sensors are fabricated to ensure sensors reproducibility. The sensors have been exposed repeatedly to the targeting VOCs to assess the repeatability of the sensors. PEI/CB sensor degradation was studied over a period of 36 days.</div><div><br></div><div>The fabricated PEI/CB film could detect (1-80 ppm) of nonanal with higher selectivity, than the f-GNPs. The sensor0s sensitivity to nonanal was over fourteen times</div><div>higher than 2-nonanone, 1-octanol, and dodecane. This shows the high selectivity of the fabricated sensor toward nonanal. In addition, the proposed sensor maintained its</div><div>sensitivity to nonanal over time showing minimal degradation. The sensor response to nonanal at a relative humidity (RH) of 50% and 85% dropped less than 13% and</div><div>32% respectively. The Response of f-GNP sensors to nonanal (400 ppb - 15 ppm), dodecane (5 - 15 ppm), 1-octanol (5 - 15 ppm), and 2-nonanone (5 - 15 ppm) presented a sensitivity (∆R/R0) of 0.217%, 0.08%, 0.192% and 0.182% per ppm of the VOCs respectively. Despite the high sensitivity to the targeting VOCs, the fabricated</div><div>sensors were damaged in an environment with relative humidity (RH) at 45%. A thin layer of PEI over the film was developed to ensure the sensor could tolerate long</div><div>time exposure to water vapor in an environment with RH up to 85% and enhance the sensor selectivity towards nonanal. The f-GNP/PEI sensors with nonanal (400 ppb- 15 ppm), dodecane (100 -200 ppm), 1-octanol (5 - 15 ppm) and 2-nonanone (5 - 15 ppm) presented sensitivity (∆R/R0) of 0.21%, 0.017%, 0.0438% and 0.0035% per ppm of the VOCs respectively. The sensor fabrication, characterization, testing methods, and results are presented and discussed.</div>

Laser-based sensors can be used as non-invasive monitoring tools to measure parts per billion (ppb) levels of trace gases. Ammonia sensors are useful for applications in environmental pollutant monitoring, atmospheric and combustion kinetic studies, and medical diagnostics. This sensor was specifically designed to measure ammonia in exhaled breath to be used as a medical diagnostic and monitoring tool, however, it can also be extended for use in other applications. Although ammonia is a naturally occurring species in exhaled breath, abnormally elevated levels can be an indication of adverse medical conditions. Laser-based breath diagnostics have many benefits since they are cost effective, non-invasive, painless, real time monitors. They have the potential to improve the quality of medical care by replacing currently used blood tests and providing immediate feedback to physicians. This sensor utilizes a Quantum Cascade Laser and Wavelength Modulation Spectroscopy with second harmonic normalized by first harmonic detection in a 76 m multi-pass absorption cell to measure ppb levels of ammonia with improved sensitivity over previous sensors. Initial measurements to determine the ammonia absorption line parameters were performed using direct absorption spectroscopy. This is the first experimental study of the ammonia absorption line transitions near 1103.46 cm-1 with absorption spectroscopy. The linestrengths were measured with uncertainties less than 10%. The collisional broadening coefficients for each of the ammonia lines with nitrogen, oxygen, water vapor, and carbon dioxide were also measured, many of which had uncertainties less than 5%. The sensor was characterized to show a detectability limit of 10 ppb with an uncertainty of less than 5% at typical breath ammonia levels. Initial breath test results showed that some of the patients with chronic kidney disease had elevated ammonia levels while others had ammonia levels in the same range as expected for healthy patients. For all of the patients the breath ammonia level decreased during dialysis but the percent decrease varied considerably for each patient. The sensor has demonstrated improved sensitivity and has been applied to measure ppb levels of ammonia in exhaled breath. Further tests have been designed to improve the sensor and continue to investigate the medical applications.

Indiana University-Purdue University Indianapolis (IUPUI) / Researchers have shown links between various hydrocarbons and carbonyl compounds and diseases, such as cancer using exhaled breath analysis through gas chromatography/mass spectroscopy (GC/MS) analysis of volatile organic compounds (VOCs). Trained canines can detect these VOCs and can differentiate a patient suffering from cancer from a healthy control patient. In this project, an attempt has been made to develop highly sensitive sensors for the detection of low concentrations of aldehyde VOCs, such as nonanal, using conductive polymer composites (CPCs) and functionalized gold nanoparticles (f-GNPs). Facile methods have been used to enhance the sensitivity and cross-selectivity of the fabricated sensors towards nonanal. Interdigitated electrodes (IDEs) are fabricated through a photolithography process. Sensors of PEI/carbon black (CB) composite were developed via spin-coating of the material followed by the heat treatment process. Sensors of 1-Mercapto-(triethylene glycol) methyl ether functionalized GNPs are developed via drop-casting of nanomaterial and f-GNP/PEI sensors are fabricated by spin casting PEI film on top of f-GNPs. Fourier Transform Infrared (FTIR) analysis, X-Ray Diffraction (XRD) analysis, contact angle measurement, and Field Emission Scanning Electron Microscopy (FESEM) analysis was conducted to characterize the fabricated devices. The fabricated sensors have been tested with a low concentration of nonanal, nonanone, dodecane, and 1-octanol in dry air. Multiple sensors are fabricated to ensure sensors reproducibility. The sensors have been exposed repeatedly to the targeting VOC toxiv assess the repeatability of the sensors. PEI/CB sensor degradation was studied over a period of 36 days. The fabricated PEI/CB film could detect (1-80 ppm) of nonanal with higher selectivity, than the f-GNPs. The sensor0s sensitivity to nonanal was over fourteen times higher than 2-nonanone, 1-octanol, and dodecane. This shows the high selectivity of the fabricated sensor toward nonanal. In addition, the proposed sensor maintained its sensitivity to nonanal over time showing minimal degradation. The sensor response to nonanal at a relative humidity (RH) of 50% and 85% dropped less than 13% and 32% respectively. The Response of f-GNP sensors to nonanal (400 ppb - 15 ppm), dodecane (5 - 15 ppm), 1-octanol (5 - 15 ppm), and 2-nonanone (5 - 15 ppm) presented a sensitivity (∆R=R0) of 0.217%, 0.08%, 0.192% and 0.182% per ppm of the VOCs respectively. Despite the high sensitivity to the targeting VOCs, the fabricated sensors were damaged in an environment with relative humidity (RH) at 45%. A thin layer of PEI over the film was developed to ensure the sensor could tolerate longtime exposure to water vapor in an environment with RH up to 85% and enhance the sensor selectivity towards nonanal. The f-GNP/PEI sensors with nonanal (400 ppb- 15 ppm), dodecane (100 -200 ppm), 1-octanol (5 - 15 ppm) and 2-nonanone (5 - 15 ppm) presented sensitivity (∆R=R0) of 0.21%, 0.017%, 0.0438% and 0.0035% per ppm of the VOCs respectively. / 2021-04-24

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