Дисертації: "Breath analysi"

1

Blackburn, Gavin J. "Breath analysis : methodology towards a fieldable breath analysis device." Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/8518.

Повний текст джерела

Анотація:

In this work lung cancer is introduced along with the current detection methods. The inadequacies of the current situation are highlighted along with the need for better detection technologies that would allow for a more rigorous testing regime to be implemented. Metabolism and metabolites are introduced as potential biomarkers. The advanced detection techniques mass spectrometry (MS) and differential mobility spectrometry (DMS) are introduced and discussed with regard to being a fieldable device. The methods applicable to processing data generated by these instruments are discussed. Finally the research objectives are highlighted. The science of breath sampling is discussed along with the considerations when engaging in breath analysis research. Sampling and trapping of volatile organic compounds (VOCs) is discussed with particular emphasis on the adaptive breath sampler which was used in this work. The benefits of a dual detector instrument allowing for analysis of a single sample using both MS and DMS are outlined. The design and implementation of a parallel, two detector system is outlined including the intricacies of balancing the two columns that operate at different pressures and developing a mount Processing DMS data currently lags behind the current hardware available as there are no methods that allow the full data surface to be utilised. This work outlines a method for transforming DMS data from three dimensions to two dimensions while retaining the full information contained within the data surface. This method was tested with generated data sets to show its' utility and compared to the current standard processing method using real data sets. An understanding of all aspects of a clinical research project is vital to ensure the smooth running and completion of the project. The currently required documentation for an outside researcher to work within the NHS are detailed along with the expected timeframe for each step of designing, gaining ethical approval and implementing the research. The use of Gantt charts and work flow diagrams is highlighted and examples are given. An initial inspection of the data produced by a pilot study shows that there a several challenges that must be overcome, these are contamination and artefact peaks, retention time shifting, unresolved peaks, differing intensities in similar samples and the complexities of correctly identifying compounds found in breath samples. These are discussed and a workflow is highlighted.

Стилі APA, Harvard, Vancouver, ISO та ін.

2

de, Silva Geethanga. "Technological Advancements in Breath Analysis." University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1481031554793468.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

3

Paredi, Paolo. "Exhaled breath analysis in lung disease." Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.406498.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

4

Qiu, Yihong. "Measurement and analysis of breath sounds." Thesis, University of Glasgow, 2003. http://theses.gla.ac.uk/1676/.

Повний текст джерела

Анотація:

Existing breath sound measurement systems and possible new methods have been critically investigated. The frequency response of each part of the measurement system has been studied. Emphasis has been placed on frequency response of acoustic sensors; especially, a method to study a diaphragm type air-coupler in contact use has been proposed. Two new methods of breath sounds measurement have been studied: laser Doppler vibrometer and mobile phones. It has been shown that these two methods can find applications in breath sounds measurement, however there are some restrictions. A reliable automatic wheeze detection algorithm based on auditory modelling has been developed. That is the human’s auditory system is modelled as a bank of band pass filters, in which the bandwidths are frequency dependent. Wheezes are treated as signals additive to normal breath sounds (masker). Thus wheeze is detectable when it is above the masking threshold. This new algorithm has been validated using simulated and real data. It is superior to previous algorithms, being more reliable to detect wheezes and less prone to mistakes. Simulation of cardiorespiratory sounds and wheeze audibility tests have been developed. Simulated breath sounds can be used as a training tool, as well as an evaluation method. These simulations have shown that, under certain circumstance, there are wheezes but they are inaudible. It is postulated that this could also happen in real measurements. It has been shown that simulated sounds with predefined characteristics can be used as an objective method to evaluate automatic algorithms. Finally, the efficiency and necessity of heart sounds reduction procedures has been investigated. Based on wavelet decomposition and selective synthesis, heart sounds can be reduced with a cost of unnatural breath sounds. Heart sound reduction is shown not to be necessary if a time-frequency representation is used, as heart sounds have a fixed pattern in the time-frequency plane.

Стилі APA, Harvard, Vancouver, ISO та ін.

5

Heaney, Liam M. "Exhaled breath analysis in exercise and health." Thesis, Loughborough University, 2016. https://dspace.lboro.ac.uk/2134/21704.

Повний текст джерела

Анотація:

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.

Стилі APA, Harvard, Vancouver, ISO та ін.

6

Modarreszadeh, Mohammad. "Systems analysis of breath to breath ventilatory variations in man: Role of carbon dioxide feedback." Case Western Reserve University School of Graduate Studies / OhioLINK, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=case1055345140.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

7

Cummings, Beth L. "Applications of infrared laser spectroscopy to breath analysis." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:5b6e0624-5982-457c-b13c-61484bace371.

Повний текст джерела

Анотація:

The work presented in this thesis is concerned with development of spectroscopic detection methods based on absorption spectroscopy using semiconductor lasers, with particular ref- erence to the ﬁeld of medical diagnostics through breath analysis. The ﬁrst part of this thesis deals with the design and testing of a prototype analyser for simultaneous monitoring of the exchange gases O₂ , CO₂ and H₂O in breath. The aim of this analyser is to provide information required to monitor respiration, with potential use in intensive care monitoring or during anaesthesia. The relatively high concentrations of these gases in breath and read- ily available diode laser sources make detection in the near-infrared (NIR) ideal. However, the relatively weakly absorbing A-band O₂ transitions at 760 nm require the application of a sensitive spectroscopic method, cavity enhanced absorption spectroscopy (CEAS). In contrast, CO₂ and H₂O are monitored using direct single pass absorption spectroscopy, with transitions arising from the 2ν₁ + ν₃ band at 2 μm and ν₁ + ν₃ band at 1.3 μm, respectively. It has been demonstrated that these gases can be detected simultaneously over a short pathlength (2.74 - 4 cm) in the respiratory ﬂow by combining various spectroscopic methodologies and real-time data analysis. This analyser is shown to offer a viable alter- native for monitoring respiration, exhibiting absolute detection limits of changes of 0.26 % O₂ , 0.02 % CO₂ and 0.003 % H₂O with a 10 ms time resolution, which are comparable to current mass spectrometry based methods, but without their inherent delays. Following this, investigations into the detection of the main gas constituents in breath in the NIR employing noise-reduction modulation based spectroscopic techniques, namely wavelength and frequency modulation (WMS and FMS respectively) are also reported. The described WMS studies on water at 1.37 μm provide a demonstration of conventional WMS detection, as well as a “proof-of-principle” example of a relatively new approach to calibrating the non-absolute information obtained from a WMS absorption signal. Typically WMS spectra are calibrated using mixtures of known gas concentrations or an absolute direct absorption spectrum where possible. In this work however, a self-calibrating method, the phasor decomposition method (PDM), is employed and the returned concentration from this calibration is compared to direct absorption measurement. From this, the calculated concentration using the PDM is found to differ by 9 % from the concentration value obtained by direct absorption, providing an alternative method of calibration for when direct absorption measurements are not possible. The use of FMS in the NIR is also demonstrated as a potential alternative to CEAS for monitoring O₂ at 760 nm. FMS detection is performed on atmospherically broadened O₂ and a time-normalised α_min(t) of 2.45 ×10⁻⁶ cm⁻¹ s^1/2 is obtained, which is two orders of magnitude less sensitive than the value of α_min(t) = 2.35 ×10⁻⁸ cm⁻¹ s^1/2 obtained with CEAS. This combined with the experimental requirements of an FMS system, make its use for detection of O₂ a less practicable option compared to CEAS for real-time breath analysis. The latter work in this thesis involves a change in focus to detection of trace gases in breath in the mid-infrared (MIR). The move of spectroscopic detection to the MIR exploits the larger absorption cross-sections available in this region, and to achieve this, a relatively new form of semiconductor laser, the quantum cascade laser (QCL) is used. The design of a continuous wave QCL spectrometer at 8 μm and its operating characteristics are demon- strated and improvements in its performances are also discussed. This QCL system is then utilised to demonstrate the potential of monitoring species in breath, namely the narrow- band absorber methane and the broadband absorber acetone, taking into consideration the potential interference from other absorbing species in breath and the diﬀerent spectroscopic characteristics exhibited by these molecules. Finally, the potential to further improve the sensitive detection of trace gases in breath in the MIR is also investigated with studies on the use of CEAS and multipass cells. In this work, the molecule of interest is the biomarker OCS, using transitions of the 2ν₂ band at 1031 cm⁻¹ , that are probed using a 10 μm QCL. The application of CEAS in the MIR is not as well developed as in the NIR, and the experimental consequences of using optical cavities at these wavelengths, where equipment tends to be more limited, are investigated and sensitivities discussed in the context of other literature. The experimental procedure of optimising a cavity for CEAS using the off-axis alignment method is also studied in detail, as well as the addition of WMS to further improve the signal quality. An effective absorption pathlength of ∼ 100 m was achieved in the cavity, with a bandwidth reduced α_min(BW) of 1.7 ×10⁻⁷ cm⁻¹ Hz^−1/2 using WMS CEAS achieved. With the poorer quality optics and limitations in equipment in the MIR for CEAS experiments, the use of a multipass cell, a 238 m Herriott cell, is also investigated as an alternative to the use of an optical cavity at 10 μm. Detection of OCS using direct absorption and WMS is demonstrated in the Herriott cell, achieving α_min(BW) = 2.03×10⁻⁸ cm⁻¹ Hz^−1/2 using WMS. This shows an improvement in sensitivity compared to WMS CEAS, and also shows the potential for future work on biomarker detection, as it approaches the ∼ ppb levels required for breath analysis.

Стилі APA, Harvard, Vancouver, ISO та ін.

8

Hamblin, D'Nisha D. "Exhaled Breath Analysis of Smokers Using CMV-GC/MS." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2605.

Повний текст джерела

Анотація:

The aim of this research was to demonstrate the potential of the novel pre-concentration device, capillary microextraction of volatiles (CMV), for breath analysis. The CMV offers dynamic sampling of volatile organic compounds with its simple coupling to a GC inlet for GC/MS analysis, avoiding expensive thermal desorption instrumentation needed for sorbent tubes, as well as an increased surface area over a single SPME fiber. CMV collectively identified 119 compounds in the breath of 13 self-reported smokers and 7 nonsmokers. The presence and intensity of twelve compounds were used to classify all the nonsmokers 100% of the time using Principal Component Analysis to elucidate the groupings. In some cases, nicotine was not detected in smokers and they were confused with the nonsmokers. Nicotine was detected in the breath of 69% of smokers with an average mass of 143 ± 31 pg for cigarette smokers from the approximate 5 L sample of breath collected. The successful use of the CMV sampler and preconcentration of breath to distinguish between smokers and nonsmokers served as a proof of concept for future applications of the CMV for detection of marijuana smokers’ breath for impaired driver management.

Стилі APA, Harvard, Vancouver, ISO та ін.

9

Meli, Louis Marcel. "Breath analysis : investigation of a low cost FTIR approach." Thesis, Cardiff University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316270.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

10

Khalid, Tanzeela Yasmin. "Breath analysis for the early recognition of hepatic encephalopathy." Thesis, University of the West of England, Bristol, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.573489.

Повний текст джерела

Анотація:

Hepatic encephalopathy (HE) is a neuropsychiatric syndrome which develops commonly in liver cirrhosis following the build up of toxic substances in the blood that cross the blood-brain barrier and affect normal brain function. The diagnosis of HE is difficult due to only subtle impairments of cognitive function at early stages of the disease and the lack of a gold standard test that specifically and reliably detects the condition. HE is associated with a poor prognosis and effective treatment largely depends on early diagnosis. Thus the aim of this work was to investigate the use of breath analysis as a non-invasive and simpler means of diagnosing HE in cirrhotic patients. This was based on the hypothesis that toxins accumulating in the blood may, if sufficiently volatile, undergo alveolar gas exchange in the lungs to be excreted in the breath. Bespoke breath testing devices were utilised for the collection of breath onto Solid-Phase Micro-Extraction (SPME) fibres and adsorbent packed Automated Thermal Desorption (A TD) tubes from cirrhotic patients with and without HE, patients with early alcohol-related health problems, patients with respiratory disease, and healthy controls. Analysis of the breath samples collected was undertaken using Gas Chromatography Mass Spectrometry. In total, 237 different compounds were identified from all samples collected using the SPME breath analyser system and 385 using the ATD breath sampling device. Multivariate discriminant analysis was used to identify Volatile Organic Compounds (VOCs) that will discriminate patients according to disease status. More compounds were associated with the presence of HE compared to the absence of HE in alcoholic cirrhotic patients. Classification rules based on the presence or absence of volatiles correctly classified the presence of HE in 86% of patients tested with the SPME technique and 88% of patients tested with the A TD technique. Breath tests based on the presence or absence of discriminatory volatiles, correctly predicted the presence of cirrhosis in 93% and 96% of alcoholic patients tested using the SPME and ATD techniques, respectively. The presence or absence of four key volatiles on the breath also helped discriminate patients with early alcohol related health problems (ARHP) from healthy cases, correctly predicting the presence of ARHP in 78% and 91 % of alcoholic patients tested using the SPME and ATD systems, respectively. The use of a targeted sensor-array device found that, on average, HE patients exhaled higher concentrations of hydrogen, alcohol, and total VOCs compared to alcoholic cirrhotic patients without clinical signs of HE, especially in the non- smoking cohort of subjects studied. This finding shows that the use of gas sensor technologies in clinical practice can provide useful diagnostic information for clinical conditions at the bedside of patients in real-time. Not all breath volatiles come from the alveolar-blood interface; many can also be produced in the oral cavity by the action of bacterial or salivary enzymes on a range of substrates. Thus gases were sampled from tongue biofilm models in vitro and this identified 32 compounds commonly detected on breath. This highlights the need for further research to determine the major source of breath volatiles in order that suitable markers of systemic disease or metabolic disorders can be identified. Overall, the results reported in this thesis suggest that breath analysis is a useful tool for the non-invasive diagnosis of a range of conditions associated with the liver such as HE, cirrhosis, and, most importantly the presence of early alcohol related health problems before any significant damage to the liver has occurred.

Стилі APA, Harvard, Vancouver, ISO та ін.

11

Lo, Wai. "Breath by breath analysis of breathing pattern in health and disease : a potential outcome measure for breathing retraining?" Thesis, University of Southampton, 2013. https://eprints.soton.ac.uk/351928/.

Повний текст джерела

Анотація:

Analysis of breathing pattern can quantify parameters of breathing such as rate, volume, timing and regularity/rhythmicity. This information can be useful to compare breathing patterns in those healthy and with disease, under different experiment conditions (such as rest versus activity) and to monitor changes over time. In this research, respiratory inductive plethysmography (RIP) was used to record breathing patterns in a group of healthy subjects and a group of severe asthma patients. RIP is a leading technology for ambulatory monitoring of breathing, but traditional RIP devices suffered from poor signal quality under such conditions due to movement of the sensor. Several authors have also raised doubts about the existing calibration methods for RIP which can lead to inaccurate estimation of breathing parameters. During the first phase of the programme, an instrumented garment (LifeShirt®) which had RIP embedded within was tested for its validity in comparison to a pneumotachograph (PT). The first study sought to validate the measurements obtained from the LifeShirt ®against PT when calibrated with a published but yet to be tested method for breath by breath analysis and to address the limitations of existing calibration methods. Eleven healthy individuals took part in this first study. Breathing patterns were simultaneously monitored by the LifeShirt ® and the PT during thirty minutes of rest and twenty minutes of exercise. Parameters of tidal volume, expiration time and tidal volume variability were recorded and compared between devices. The analysis from the first study demonstrated that RIP recorded proportionate changes of tidal volume and expiration duration relative to PT during quiet breathing and exercise. Mean tidal volume and expiration duration between devices was strongly correlated for rest and exercise. No statistical difference in tidal volume variability was observed between devices during either period. Significant differences in expiration duration between devices were observed in all participants at rest but not during exercise. Results of this first study demonstrated that valid breath by breath analysis using RIP without PT was feasible. This is clinically advantageous due to simplicity of set-up for RIP. In the second phase, measurement of breathing patterns was made in severe asthma patients with the LifeShirt® alone during thirty minutes of rest. It intended to add new knowledge with regards to the breathing patterns within this small population as compared to the healthy population. Ten healthy individuals and ten patients diagnosed with severe asthma took part in the second study. Breathing parameters of tidal volume, inspiration time, expiration time, end tidal carbon dioxide levels, tidal volume variability and end tidal carbon dioxide levels variability were recorded by the LifeShirt®. The analysis of the second phase shown no evidence that breathing pattern parameters could differentiate between the severe asthma patients and healthy volunteers in our small study. The symptoms of hyperventilation found more commonly in the severe asthma group were not associated with differences in breathing pattern parameters. However, considerable differences were found between individuals. This suggests the existence of individuality in breathing patterns between individuals. Such findings raised doubts as to whether there is a group ‘pattern’ that is common within the severe asthma population or within the healthy population. This programme calls for a change in paradigm to consider breathing patterns as an unique individual ‘trait’ rather than as a group characteristic.

Стилі APA, Harvard, Vancouver, ISO та ін.

12

Tesfalem, Geremariam Welearegay. "Exhaled Breath Analysis for Non-Invasive Diagnosis of Tropical Diseases." Doctoral thesis, Universitat Rovira i Virgili, 2019. http://hdl.handle.net/10803/665616.

Повний текст джерела

Анотація:

Les malalties tropicals desateses (MTD) pertanyen al grup de malalties infeccioses. Són endèmiques en la major part del món i afecten més de mil milions de persones a tot el món, especialment a les poblacions de baixos ingressos de les regions en desenvolupament. La infecció en humans es caracteritza per un període d'incubació asimptomàtica crònica i perllongada sense símptomes notables de la malaltia, el que retarda la prescripció d'un tractament mèdic adequat i oportú. La prevenció, el diagnòstic i el control d'aquestes malalties segueixen sent un desafiament metge no resolt encara. Aquesta tesi ha tingut com a objectiu desenvolupar una metodologia no invasiva, segura i amigable per al pacient per a un diagnòstic ràpid de les MTD. L'enfocament de la meva tesi es va basar en el diagnòstic de la malaltia a través de l'anàlisi de mostres d'alè exhalat, que són fàcils d'obtenir i no presenten molèsties ni riscos per a la salut dels pacients. El treball de la meva tesi es va centrar en tres tipus diferents de malalties tropicals desateses (dengue, equinococcosi i leishmaniosi) causades per tres patògens diferents (infeccions virals, helmínticas i protozoàries, respectivament). Les mostres d'alè es van recollir amb dispositius homologats Bio-VOC, que són fàcils d'usar i requereixen d'una preparació mínima. Per analitzar les mostres d'alè, primer es van emprar tècniques analítiques estàndard per a la identificació dels biomarcadors volàtils d'aquestes malalties. Un altre dels objectius de la meva tesi va ser dissenyar i fabricar una matriu de sensors químics de gasos amb sensibilitats creuades basats en nanopartícules de metall ultrapur funcionalitzades amb diversos compostos orgànics, per la qual cosa vaig emprar una tècnica innovadora basada en deposició física en fase vapor. Els nous sensors van ser caracteritzats i es van emprar per identificar els patrons de les malalties estudiades en les mostres d'alè. Les respostes dels sensors químics de gasos exposats a les mostres d'alè es van usar per a construir models de reconeixement de patrons per al diagnòstic d'aquestes malalties. Els resultats obtinguts han revelat que l'anàlisi de l'alè exhalat amb una matriu de sensors de gasos basats en nanoensamblajes de nanopartícules de metall ultrapur té un gran potencial com a prova diagnòstica fiable per a les MTD.
Las enfermedades tropicales desatendidas (ETD) pertenecen al grupo de enfermedades infecciosas. Son endémicas en la mayor parte del mundo y afectan a más de mil millones de personas en todo el mundo, especialmente a las poblaciones de bajos ingresos de las regiones en desarrollo. La infección en humanos se caracteriza por un período de incubación asintomática crónica y prolongada sin síntomas notables de la enfermedad, lo que retrasa la prescripción de un tratamiento médico adecuado y oportuno. La prevención, el diagnóstico y el control de estas enfermedades siguen siendo un desafío médico no resuelto aún. Esta tesis ha tenido como objetivo desarrollar una metodología no invasiva, segura y amigable para el paciente para un diagnóstico rápido de las ETD. El enfoque de mi tesis se basó en el diagnóstico de la enfermedad a través del análisis de muestras de aliento exhalado, que son fáciles de obtener y no presentan molestias ni riesgos para la salud de los pacientes. El trabajo de mi tesis se centró en tres tipos diferentes de enfermedades tropicales desatendidas (dengue, equinococosis y leishmaniasis) causadas por tres patógenos diferentes (infecciones virales, helmínticas y protozoarias, respectivamente). Las muestras de aliento se recogieron con dispositivos homologados Bio-VOC, que son fáciles de usar y requieren de una preparación mínima. Para analizar las muestras de aliento, primero se emplearon técnicas analíticas estándar para la identificación de los biomarcadores volátiles de estas enfermedades. Otro de los objetivos de mi tesis fue diseñar y fabricar una matriz de sensores químicos de gases con sensibilidades cruzadas basados en nanopartículas de metal ultrapuro funcionalizadas con diversos compuestos orgánicos, para lo cual empleé una técnica innovadora basada en deposición física en fase vapor. Los nuevos sensores fueron caracterizados y se emplearon para identificar los patrones de las enfermedades estudiadas en las muestras de aliento. Las respuestas de los sensores químicos de gases expuestos a las muestras de aliento se usaron para construir modelos de reconocimiento de patrones para el diagnóstico de estas enfermedades. Los resultados obtenidos han revelado que el análisis del aliento exhalado con una matriz de sensores de gases basados en nanoensamblajes de nanopartículas de metal ultrapur
Neglected Tropical Diseases (NTDs) belong to the group of infectious diseases. They are endemic in most parts of the world, affecting more than one billion people worldwide, especially low income populations from developing regions. The infection to humans is characterized by a chronic and prolonged asymptomatic incubation period without noticeable symptoms of the disease, which delays the prescription of a suitable and timely medical treatment. The prevention, diagnosis and control of these diseases still remain an unsolved medical challenge. This thesis aimed to develop a non-invasive, safe and patient-friendly methodology for rapid diagnosis of NTDs. The thesis approach was based on disease diagnosis via exhaled breath samples analyses, which are easy to obtain and present no discomfort or risk for patients’ health. The thesis work was focused on three different types of neglected tropical diseases (Dengue, Echinococcosis and Leishmaniasis) caused by three different pathogens (viral, helminthic and protozoan infections, respectively). Breath collection was realized with homologated Bio-VOCTM breath samplers, which are simple and user friendly and require minimal training. For analyzing the breath samples, at first standard analytical techniques were employed for the identification of the breath volatile biomarkers of these diseases. As another objective of my thesis, an array of cross reactive chemical gas sensors based on ultrapure metal nanoparticles – ligand nanoassemblies comprising diverse functional organic ligands was designed and fabricated employing an innovative physical deposition route. The new sensors were characterized and employed for the analysis of the breath print profiles of the diseases under study. The responses of the chemical gas sensors to the breath samples were used to build predictive pattern recognition models for the diagnoses of these diseases. The results obtained revealed that exhaled breath analysis with cross reactive gas sensors arrays based on ultrapure metal nanoparticles-ligand nanoassemblies holds significant potential as a cost-effective, simple and non-invasive diagnostic test for NTDs.

Стилі APA, Harvard, Vancouver, ISO та ін.

13

Turner, Matthew A. "Boundaries in volatile organic compounds in human breath." Thesis, Loughborough University, 2016. https://dspace.lboro.ac.uk/2134/20274.

Повний текст джерела

Анотація:

Exhaled breath is a rich and complex matrix containing many hundreds of compounds. Every breath offers the potential of a non-invasive measurement of the biochemical processes occurring in the human body and it is this notion that has led to the application of breath analysis for the detection of disease. With the majority of research in the field being focused on the detection of biomarkers, little has been presented on how the seemingly homeostatic matrix of breath varies during the course of normal life events. The research in this thesis describes how a subject's emotional state, physical state, and daily activities can alter the composition of exhaled breath.

Стилі APA, Harvard, Vancouver, ISO та ін.

14

Ibrahim, Baharudin. "Exhaled breath analysis for diagnosis and phenotyping in obstructive lung diseases." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/exhaled-breath-analysis-for-diagnosis-and-phenotyping-in-obstructive-lung-diseases(17a130d4-4c44-43af-a006-65939c7315f7).html.

Повний текст джерела

Анотація:

Introduction: Asthma and chronic obstructive pulmonary disease (COPD) are heterogeneous diseases with a wide range of clinical manifestations not adequately described within the current diagnostic criteria. Exhaled breath analysis may provide a novel method for diagnosing and phenotyping these diseases. Our aim was to ascertain patterns of breath volatile organic compounds (VOCs) and nuclear magnetic resonance (NMR) spectral regions identifying diseased patients and subgroups determined by treatment requirement, asthma control, exacerbation frequency and inflammatory phenotypes. The validity and reproducibility of the methodology and the outcome were also investigated. Methods: Three separate clinical studies (two involving exhaled gas and one involving breath condensate) were conducted, as well as validation studies. In exhaled gas analysis, the adaptive breath sampler developed by Basanta et al was modified; efficiency of air supply and air filter and the reproducibility and stability of VOCs in storage were determined by comparing breath chromatograms. Concentrated late-expiratory breath samples were collected from asthmatics, COPD subjects and healthy controls. In the asthmatic group, sputum induction with hypertonic saline, fraction exhaled nitric oxide (FeNO) measurement and asthma control questionnaire (ACQ) were performed. In COPD subjects, sputum induction and exacerbation frequency were collected. In the exhaled breath condensate (EBC) study, similar data were collected in asthmatics and healthy controls. Breath samples were analysed using gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) while EBC was analysed using NMR spectroscopy. Discriminatory compounds or NMR spectral regions were identified by univariate logistic regression, followed by multivariate analysis: 1. principal component analysis (PCA); 2. multivariate logistic regression; 3. receiver operating characteristic (ROC) analysis. The reproducibility was assessed using intraclass correlation coefficient (ICC).Results: In the COPD exhaled breath study, 11 VOCs significantly discriminated the COPD and healthy controls with AUROC of 0.74. The AUROC for phenotype discrimination was 0.83, 0.90, 0.94, 0.96 and 0.97 for inhaled corticosteroid (ICS) use, sputum eosinophilia (1% and 2% cut-off), neutrophilia (median cut-off) and exacerbation frequency respectively. In the asthma study, 15 VOCs significantly discriminated the two groups with AUROC of 0.93. The AUROC for phenotype discrimination was 0.96, 0.98, 0.90 and 0.97 for ICS use, eosinophils (2% cut-off), neutrophils (40% cut-off) and asthma control respectively. In EBC analysis, AUROC for asthmatics vs controls comparison was 0.96. Phenotyping results in this study were less good: only ICS use and sputum neutrophilia (65% cut-off) were clearly classified with AUROC of 0.89 and 0.88 while eosinophilia (3% cut-off) and asthma control had poor discrimination; 0.69 and 0.62 respectively. Breath VOC reproducibility varied greatly depending on the class of compounds studied, while for the EBC analysis, reproducibility was moderate to very good (ICCs in the range of 0.42-0.99).Conclusions: We have demonstrated the ability of breath analysis in discriminating asthmatics and COPD subjects from controls. Exhaled breath analysis was also able to phenotype these patients based on steroid treatment, sputum inflammatory cells, exacerbation frequency and asthma control. This metabolomic approach could provide a novel, non-invasive method of diagnosing and phenotyping obstructive lung diseases in the future.

Стилі APA, Harvard, Vancouver, ISO та ін.

15

Lui, Qiao. "Anticipatory breach of contract : A critical analysis." Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.530051.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

16

PELLEGRINI, RAFFAELLA. "Listen to my breath: Exploring expressive function of breathing sounds in imitation and emotional attunement." Doctoral thesis, Università Cattolica del Sacro Cuore, 2012. http://hdl.handle.net/10280/1271.

Повний текст джерела

Анотація:

Diversi studi hanno dimostrato i reciproci rapporti di influenza tra respiro e variabili psicologiche ma scarsa attenzione è stata rivolta all’indagine delle funzioni espressive del suono del respiro. Studio 1 è stato finalizzato alla costruzione di un modello di analisi multi-livello per la descrizione acustica del respiro. Sono state effettuate audio e video registrazioni del respiro di 2 coppie di soggetti in performance individuali e congiunte. Sui 1903 respiri raccolti sono state condotte analisi video e audio che hanno portato alla costruzione di tre categorie di indici: respiratori, acustici e interattivi (relativi alla relazione tra i comportamenti respiratori di due partners in un’azione congiunta). Studio 2 ha investigato cosa poteva essere inferito dall’ascolto del suono respiro relativamente all’identità, allo stato emotivo e all’attività svolta da una persona. Inoltre, ha verificato se l’imitazione facilitasse l’identificazione rispetto al solo ascolto. Sono state raccolte registrazioni ecologiche del respiro di persone coinvolte in 6 attività e 4 emozioni. Un campione di 90 persone ha ascoltato le tracce e risposto ad un questionario relativo alle suddette variabili. Altre 90 persone prima di rispondere imitavano il respiro. Il campione ha efficacemente inferito informazioni relative alle variabili indagate, con risultati migliori nel task di imitazione. Studio 3 mirava a descrivere acusticamente 6 condizioni di respiro emotivo (rabbia, paura, tristezza, disgusto, tenerezza, gioia) e a investigare se “respirare insieme” influenzasse il processo di sintonizzazione. 20 coppie di donne hanno partecipato. Per ogni emozione, entro ogni coppia una partecipante leggeva una storia emotivamente connotata e respirava come se si trovasse in quella situazione. L’altra esprimeva la propria vicinanza respirando come lei. Al termine rispondevano a un questionario. I respiri sono stati audio registrati e analizzati. E’ stato possibile ricondurre ciascuna delle emozioni a un differente pattern respiratorio. Inoltre il task ha influenzato diverse dimensioni della sintonizzazione: la sincronizzazione, il decoding emotivo, l’esperienza emotiva e la percezione di somiglianza interpersonale.
Several psycho-physiological studies have provided evidences about the reciprocal influence between respiration and psychological variables but few attentions have been brought to the investigation of the expressive function of breathing sounds. Study 1 aims to build a multilayer analysis model that enable an acoustic description of breathing sounds. Audio and video recordings of breathing of two pairs of participants engaged in individual and joint performance were conducted. 1903 were video and audio analyzed and 3 sets of indexes were derived: respiratory, acoustic and interactive (aimed to relate partner’s respiratory behaviour during joint performances). Study 2 investigates what could be inferred about a person’s identity, emotional state and activity from the sound of his/her breathing. Moreover, it aims to verify whether imitation of breathing patterns improve the identification of those features. Ecological recordings of breathing sounds of people engaged in 6 activities and 4 emotions. 90 participants listen to the tracks and answer a questionnaire about such variables. Other 90 mimicked the tracks before answering. Participants were able to infer valuable information about the aspects under investigation with better results in the imitation task. Study 3 aims to describe the acoustic features of 6 emotional breathing patterns (anger, fear, sadness, disgust, tenderness and joy) and to see whether breathing together could strengthen the attunement process. 20 pairs of women participated. For each emotion, within the pair one participant read a story emotionally connoted and breathes as if she actually was in that situation. Her partner had to convey her closeness breathing in the same way. Finally they filled in a questionnaire. Different respiratory patterns were related to each emotion. Moreover the task influenced several attunement dimensions: synchronization, emotional decoding, emotional experience and perception of interpersonal similarity.

Стилі APA, Harvard, Vancouver, ISO та ін.

17

PELLEGRINI, RAFFAELLA. "Listen to my breath: Exploring expressive function of breathing sounds in imitation and emotional attunement." Doctoral thesis, Università Cattolica del Sacro Cuore, 2012. http://hdl.handle.net/10280/1271.

Повний текст джерела

Анотація:

Diversi studi hanno dimostrato i reciproci rapporti di influenza tra respiro e variabili psicologiche ma scarsa attenzione è stata rivolta all’indagine delle funzioni espressive del suono del respiro. Studio 1 è stato finalizzato alla costruzione di un modello di analisi multi-livello per la descrizione acustica del respiro. Sono state effettuate audio e video registrazioni del respiro di 2 coppie di soggetti in performance individuali e congiunte. Sui 1903 respiri raccolti sono state condotte analisi video e audio che hanno portato alla costruzione di tre categorie di indici: respiratori, acustici e interattivi (relativi alla relazione tra i comportamenti respiratori di due partners in un’azione congiunta). Studio 2 ha investigato cosa poteva essere inferito dall’ascolto del suono respiro relativamente all’identità, allo stato emotivo e all’attività svolta da una persona. Inoltre, ha verificato se l’imitazione facilitasse l’identificazione rispetto al solo ascolto. Sono state raccolte registrazioni ecologiche del respiro di persone coinvolte in 6 attività e 4 emozioni. Un campione di 90 persone ha ascoltato le tracce e risposto ad un questionario relativo alle suddette variabili. Altre 90 persone prima di rispondere imitavano il respiro. Il campione ha efficacemente inferito informazioni relative alle variabili indagate, con risultati migliori nel task di imitazione. Studio 3 mirava a descrivere acusticamente 6 condizioni di respiro emotivo (rabbia, paura, tristezza, disgusto, tenerezza, gioia) e a investigare se “respirare insieme” influenzasse il processo di sintonizzazione. 20 coppie di donne hanno partecipato. Per ogni emozione, entro ogni coppia una partecipante leggeva una storia emotivamente connotata e respirava come se si trovasse in quella situazione. L’altra esprimeva la propria vicinanza respirando come lei. Al termine rispondevano a un questionario. I respiri sono stati audio registrati e analizzati. E’ stato possibile ricondurre ciascuna delle emozioni a un differente pattern respiratorio. Inoltre il task ha influenzato diverse dimensioni della sintonizzazione: la sincronizzazione, il decoding emotivo, l’esperienza emotiva e la percezione di somiglianza interpersonale.
Several psycho-physiological studies have provided evidences about the reciprocal influence between respiration and psychological variables but few attentions have been brought to the investigation of the expressive function of breathing sounds. Study 1 aims to build a multilayer analysis model that enable an acoustic description of breathing sounds. Audio and video recordings of breathing of two pairs of participants engaged in individual and joint performance were conducted. 1903 were video and audio analyzed and 3 sets of indexes were derived: respiratory, acoustic and interactive (aimed to relate partner’s respiratory behaviour during joint performances). Study 2 investigates what could be inferred about a person’s identity, emotional state and activity from the sound of his/her breathing. Moreover, it aims to verify whether imitation of breathing patterns improve the identification of those features. Ecological recordings of breathing sounds of people engaged in 6 activities and 4 emotions. 90 participants listen to the tracks and answer a questionnaire about such variables. Other 90 mimicked the tracks before answering. Participants were able to infer valuable information about the aspects under investigation with better results in the imitation task. Study 3 aims to describe the acoustic features of 6 emotional breathing patterns (anger, fear, sadness, disgust, tenderness and joy) and to see whether breathing together could strengthen the attunement process. 20 pairs of women participated. For each emotion, within the pair one participant read a story emotionally connoted and breathes as if she actually was in that situation. Her partner had to convey her closeness breathing in the same way. Finally they filled in a questionnaire. Different respiratory patterns were related to each emotion. Moreover the task influenced several attunement dimensions: synchronization, emotional decoding, emotional experience and perception of interpersonal similarity.

Стилі APA, Harvard, Vancouver, ISO та ін.

18

Wong, Hon-wai Francis, and 黃漢偉. "Breath hydrogen (H2) analysis for detecting lactose malabsorption in Chinese children." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1988. http://hub.hku.hk/bib/B31208976.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

19

Guo, Tianle. "Chemical Analysis of Exhaled Breath by Means of Terahertz Rotational Spectroscopy." Wright State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=wright1408732018.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

20

Schueler, Robert M. "Terahertz Spectroscopic Breath Analysis as a Viable Analytical Chemical Sensing Technique." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1464170300.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

21

Ma, Xinyi. "The effect of the random breath testing policy in Australia." Thesis, The University of Sydney, 2013. http://hdl.handle.net/2123/10281.

Повний текст джерела

Анотація:

Road crashes are a major cause of death and serious injuries in many countries and extract a high cost on society. Drink driving is one of the most important reasons for road crashes. Many countries have enacted drink-driving policy and legislation. In Australia, Random Breath Testing (RBT) program is the main legislation against drink driving. This research examines the effect of RBT program by investigating whether RBT program is effective in reducing road accident rates; and whether there is a relationship between increased RBT enforcement level and decreased road accident rates. The road accident data from New South Wales (NSW), Queensland (QLD), Western Australia (WA) and Tasmania (TAS) in Australia during the time period 1978-1992 are analysed in three models. Model 1 investigates the effect of RBT program using interrupted time series (ITS) analysis, finding that the RBT program is effective in reducing road accident rates in all four States. Model 2 estimates the effect of RBT enforcement level on road accident rates. The results of Model 2 indicate that increasing RBT enforcement level reduces fatal accident rate (TFAR) in all States, reduces single-vehicle night-time accident rate (SVNAR) in all States except QLD, and reduces serious accident rate (TSAR) in WA and TAS. In addition, the implemented RBT enforcement levels are found effective in NSW, below effective level in WA, and above effective level in QLD and TAS. Model 3 reexamines the effect of RBT enforcement level on road accident rates without imposing any functional form of the RBT enforcement level using the semiparametric regression model. The estimation results in Model 3 are generally consistent with the findings in Model 2, in the sense that increasing RBT enforcement level is effective in reducing road accident rates only when RBT enforcement level lies within a specific range for each State. Conclusions, policy implications and limitations are discussed at the end of the thesis.

Стилі APA, Harvard, Vancouver, ISO та ін.

22

Reinoso, Luis Enrique. "User interface optimization through breadth of distribution analysis." Monterey, California. Naval Postgraduate School, 1997. http://hdl.handle.net/10945/9116.

Повний текст джерела

Анотація:

Approved for public release; distribution is unlimited
A Java tutorial was developed as a World Wide Web (WWW) site for use in capturing user behavior data. Breadth of distribution analysis was then applied to the data collected in order to characterize the usage of the user interface through the shape, connectedness, and order of traversal of each user in the sample. The results reveal distinct user groups with different levels of user knowledge and needs in relation to the web site content The resulting user interface analysis process produces a set of recommendations for optimizing the user interface, including adaptive interfaces for different user subgroups and optimization of sequential rather than topical presentations

Стилі APA, Harvard, Vancouver, ISO та ін.

23

Langley, Cathryn Elinor. "Development of techniques for trace gas detection in breath." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:58ceee0c-18f7-4bfc-adfb-829d24859564.

Повний текст джерела

Анотація:

This thesis aims to investigate the possibility of developing spectroscopic techniques for trace gas detection, with particular emphasis on their applicability to breath analysis and medical diagnostics. Whilst key breath molecules such as methane and carbon dioxide will feature throughout this work, the focus of the research is on the detection of breath acetone, a molecule strongly linked with the diabetic condition. Preliminary studies into the suitability of cavity enhanced absorption spectroscopy (CEAS) for the analysis of breath are carried out on methane, a molecule found in varying quantities in breath depending on whether the subject is a methane-producer or not. A telecommunications near-infrared semiconductor diode laser (1.6 µm) is used with an optical cavity based detection system to probe transitions within the vibrational overtone of methane. Achieving a minimum detectable sensitivity of 600 ppb, the device is used to analyse the breath of 48 volunteers, identifying approximately one in three as methane producers. Following this, a second type of laser source, the novel and widely tunable Digital Supermode Distributed Bragg Reflector (DS-DBR) laser, is characterised and the first demonstration of its use in spectroscopy documented. Particular emphasis is given to its application to CEAS and to probing the transitions of the two Fermi resonance components of the CO_2 3ν_1 + ν_3 combination bands found within the spectral range (1.56 - 1.61 µm) of the laser, providing the means to determine accurate ^{13}CO_2/^{12}CO_2 ratios for use in the urea breath test. Not all molecules exhibit narrow, well-resolved ro-vibrational transitions and the next section of the thesis focuses on the detection of molecules, such as acetone, with broad, congested absorption features which are not readily discernible using narrowband laser sources. To provide the necessary specificity for these molecules, two types of broadband source, a Superluminescent Light Emitting Diode (SLED) and a Supercontinuum source (SC), both emitting over the 1.6 - 1.7 µm region, are used in the development of a series of broadband cavity enhanced absorption (BB-CEAS) spectrometers. The three broadband absorbers investigated here, butadiene, acetone and isoprene, all exhibit overtone and combination bands in this spectral region and direct absorption measurements are taken to determine absorption cross-sections for all three molecules. The first BB-CEAS spectrometer couples the SLED device with a dispersive monochromator, attaining a minimum detectable sensitivity of 6 x 10^{-8} cm^{-1}, which is further enhanced to 1.5 x 10^{-8} cm^{-1} on replacing the monochromator with a Fourier Transform interferometer. The spectral coverage is then extended to 1.5 - 1.7 µm by coupling the first SLED with a second device, providing a demonstration of simultaneous multiple species detection. Finally, a SC source is used to provide greater power and uniform spectral intensity, resulting in an improved minimum detectable sensitivity of 5 x 10^{-9} cm^{-1}, or 200 ppb, 400 ppb and 200 ppb for butadiene, acetone and isoprene respectively. This device is then applied to acetone-enriched breath samples; the resulting spectra are fitted with a simulation to return the acetone levels present in the breath-matrix. Following this, the development of a prototype breath acetone analyser, carried out at Oxford Medical Diagnostics Ltd. (OMD), is described. To fulfill the requirements of a compact and commercially-viable device, a diode laser-based system is used, which necessitates a thorough investigation into all possible sources of absorption level change. Most notably, this includes a study into the removal and negating of interfering species, such as water vapour, and to a lesser extent, methane. A novel solution is presented, utilising a water-removal device in conjunction with molecular sieve so that each breath sample generates its own background, which has allowed breath acetone levels to be measured within an uncertainty of 200 ppb. Spectroscopic detection then moves to the mid-infrared with the demonstration of a continuous wave 8 µm quantum cascade laser, which allows the larger absorption cross-sections associated with fundamental vibrational modes to be probed. Following the laser's characterisation using methane, including a wavelength modulation spectroscopy study, the low effective laser linewidth is utilised to resolve rotational structure in low pressure samples of pure acetone. Absorption cross-sections are determined before the sensitivity of the system is enhanced for the detection of dilute concentrations of acetone using two types of multipass cells, firstly a White cell and secondly a home-built Herriott cell. This allows an acetone minimum detectable absorption of 350 ppb and 20 ppb to be attained, respectively. Following this, an optical cavity is constructed and, on treating breath samples in a water-removal device prior to analysis, breath acetone levels determined and corroborated with a mass spectrometer. Finally, a preliminary study probing acetone in the ultraviolet is presented. Utilising an LED centred at 280 nm with a low finesse optical cavity and an imaging spectrograph, detection of 25 ppm of acetone is demonstrated and possible vibronic structure resolved. Combining large absorption cross-sections with the potential to be compact and commercially viable, further development of this arrangement could ultimately represent the optimum solution for breath acetone detection.

Стилі APA, Harvard, Vancouver, ISO та ін.

24

Dufaye, Guillaume. "Modélisation mécanique et numérique du comportement des bustes féminins." Thesis, Troyes, 2014. http://www.theses.fr/2014TROY0037/document.

Повний текст джерела

Анотація:

La modélisation avancée du comportement réel des bustes féminins en statique ou en dynamique doit tenir compte des constituants biologiques du sein. La simulation numérique de la déformabilité de sein permettrait le développement de nouvelles techniques de confections pour la corsetterie ou de nouveaux appareillages médicaux, notamment pour le dépistage du cancer du sein. Dans cette étude, une approche expérimentale-simulation-optimisation prenant en compte les constituants (peau, graisse et glandes) responsables de la déformabilité du sein sous l’effet de la gravité est proposée. Pour cela, des modèles géométriques 3D ont été générés à partir d’images IRM afin de reconstruire les constituants internes. Des outils de maillages surfaciques et volumiques adaptatifs ont été utilisés pour les besoins des simulations éléments finis sur Comsol. Des essais expérimentaux de la déformabilité des bustes en statique et dynamique ont pu être réalisé à l’aide d’un système de scanner 3D par caméras et d’un banc spécifique d’inclinaison des bustes. Des modèles numériques des seins ont été confronté aux expérimentations et à la littérature afin d’identifier et d’optimiser par approche inverse les caractéristiques des seins
Advanced modeling of female bust behaviour in static or dynamic must consider the biological of each components of the breast. The numerical simulation of breast deformation enables the development of new techniques for confections corsetry or new medical devices, including screening for breast cancer. In this study, an experimental-simulation-optimization approach that takes into account the components (skin, fat and glands) responsible for the deformability of the breast under the gravity loading is proposed. Geometrical models were generated from MRI images for 3D reconstruction of internal components is used with using advanced adaptive mesh surface and volume for purposes of finite element simulations using Comsol Multiphysics. Experimental tests are developed using a 3D scanner cameras and a special gear for study the busts deformability in static and dynamic. Numerical hyperelastic models of Comsol Multiphysics FEA are using for breasts deformation to characterize and optimize with reverse approach the breast mechanical properties. Confrontation with experimental and literature results is proposed in order to demonstrate the efficiency of our approach

Стилі APA, Harvard, Vancouver, ISO та ін.

25

Alklid, Jonathan. "Twitch, a Breath of Fresh Air? : An Analysis of Sexism on Twitch.tv." Thesis, Linnéuniversitetet, Institutionen för språk (SPR), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-40326.

Повний текст джерела

Анотація:

The issue of sexism is arguably an important topic in modern society in several aspects of life. With the introduction of the Internet and communication over the Internet, additional potential sources of sexism have emerged. While there appears to have been a significant number of studies regarding sexism in cyberspace, Twitch.tv is a relatively new platform and seems yet to be properly explored. Therefore, while being limited in size, the present study aims to provide an introduction to Twitch.tv by performing a limited investigation of the extent of sexist behaviour and ideas expressed by users on the site, particularly against female streamers. To accomplish this, 30,000 lines of chat messages from six different chatrooms, three belonging to women and the remaining three to men, were examined for sexist behaviour, based on a variety of parameters such as differences in language complexity and instances of sexist remarks. The results suggested that several varieties of sexism existed on Twitch, and was directed at both men and women, where women seemed to be more heavily affected than men. The conclusion of the study is that Twitch does not seem to be a breath of fresh air in cyberspace as it appears to embody numerous sexist ideas. However, the author notes that Twitch could serve as a potentially useful source of data for future gender studies online.

Стилі APA, Harvard, Vancouver, ISO та ін.

26

Sadhu, Vijay. "Internal erosion and simplified breach analysis: (upgraded version 2012)." Kansas State University, 2012. http://hdl.handle.net/2097/13923.

Повний текст джерела

Анотація:

Master of Science
Department of Computing and Information Sciences
Mitchell L. Neilsen
In recent years, headline news has been overwhelmed with stories about dam and levee failures including the 2005 levee breaches in New Orleans and the 2006 Kaloko Damfailure in Hawaii that resulted in seven deaths. Since 2000, state and federal agencies have reported 92 dam failures in the United States to the National Performance of Dams Program. Incidents such as these have brought both national and worldwide attention to the need for improved flood warning systems and breach prediction tools for dam embankment and levee failures. (G. J. Hanson, 2010) IESIMBA 2012 is an upgraded version of SIMBA, which has been upgraded from VB6 to C#.NET. The Microsoft Windows-based SIMplified Breach Analysis software (SIMBA) was developed by the USDA Agricultural Research Service in cooperation with Kansas State University. The software was developed for the purpose of analyzing internal erosion, earth embankment breach test data and extending the understanding of the underlying physical processes of breach of an overtopped earth embankment. It is a research tool that is modified routinely to test the sensitivity of the output to various sub-models and assumptions. This software is a test version for use in validation testing of the simplified breach model based on stress and mass failure driven headcut movement. It runs under Microsoft Windows 98SE, Windows 2000, NT, XP, or Vista. The following Input Screens are used to guide the user through development of input data sets.  Model Properties , Dam Profile , Structure Table, Spillway Rating and Hydrograph Data After an input data set has been entered, the data is saved and simulation can be performed on the data stored in memory at any time by selecting Build option. Input and output files are stored in a fixed ASCII text format. The results of the simulation can be viewed in graphical format which are of interest to the researchers at Oklahoma State University, Stillwater by selecting View option.

Стилі APA, Harvard, Vancouver, ISO та ін.

27

Galletti, Thomas. "Data breach - services for threat detection, analysis and response." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/7026/.

Повний текст джерела

Анотація:

Nel mondo della sicurezza informatica, le tecnologie si evolvono per far fronte alle minacce. Non è possibile prescindere dalla prevenzione, ma occorre accettare il fatto che nessuna barriera risulterà impenetrabile e che la rilevazione, unitamente ad una pronta risposta, rappresenta una linea estremamente critica di difesa, ma l’unica veramente attuabile per poter guadagnare più tempo possibile o per limitare i danni. Introdurremo quindi un nuovo modello operativo composto da procedure capaci di affrontare le nuove sfide che il malware costantemente offre e allo stesso tempo di sollevare i comparti IT da attività onerose e sempre più complesse, ottimizzandone il processo di comunicazione e di risposta.

Стилі APA, Harvard, Vancouver, ISO та ін.

28

Yang, Chi-ting, and 楊志婷. "Pharmacokinetics of alcohol using breath measures and some statisticalaspects in forensic science." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B46506159.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

29

Smith, Aaron D. "Stochastic permanent breaks /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1999. http://wwwlib.umi.com/cr/ucsd/fullcit?p9938588.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

30

Kaisdotter, Andersson Annika. "Improved breath alcohol analysis with use of carbon dioxide as the tracer gas." Doctoral thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-9743.

Повний текст джерела

Анотація:

State-of-the-art breath analysers require a prolonged expiration into a mouthpiece to obtain the accuracy required for evidential testing and screening of the alcohol concentration. This requirement is unsuitable for breath analysers used as alcolock owing to their frequent use and the fact that the majority of users are sober drivers; as well as for breath testing in uncooperative persons. This thesis presents a method by which breath alcohol analysis can be improved, using carbon dioxide (CO2) as the tracer gas, offering quality control of the breath sample, enabling the mouthpiece to be eliminated, and bringing about a significant reduction in the time and effort required for a breath alcohol screening test. With simultaneous measurement of the ethanol and the CO2 concentrations in the expired breath, the end-expiratory breath alcohol concentration (BrAC) can be estimated from an early measurement, without risk of underestimation. Comparison of CO2 and water (H2O) as possible tracer gases has shown that the larger intra- and inter-individual variations in the (end-expiratory) concentration is a drawback for CO2 whereas the advantages are a low risk of underestimation of the BrAC, and the limited influence from ambient conditions on the measured CO2 concentration. The latter is considered to be of importance because the applications likely imply that the breath tests will be conducted in an uncontrolled environment, e.g., in a vehicle or ambulance. In emergency care, the measurement of the expired CO2 concentration also provides the physicians with information about the patient's respiratory function. My hope and belief, is that with a more simple, reliable and, user-friendly test procedure, enabled with the simultaneous measurement of the CO2 in the breath sample, the screening for breath alcohol will increase. An increased number of breath alcohol analysers installed as alcolocks and more breath alcohol tests conducted in emergency care, is likely to save lives and diminish the number and severity of injuries.

Стилі APA, Harvard, Vancouver, ISO та ін.

31

Liu, Haixia. "Texture Feature Analysis of Breast Lesions in Automated 3D Breast Ultrasound." Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-211923.

Повний текст джерела

Анотація:

This thesis investigated a variety of texture features performances on classifying and detecting breast lesions in automated 3D breast ultrasound (ABUS) images with computer-aided diagnosis and detection system. Regions detected by the computer-aided detection system could be categorized into benign and malignant classes, which are supposed to have different texture features. After normalization and segmentation on the original 3D ultrasound breast images automatically, we implemented four texture feature extraction algorithms on the detected targets. The proposed four algorithms are based on 3-dimensional gray level co-occurrence matrix (3-D GLCM), local binary pattern (LBP), Haar-Like and regional zernike moment (RZM) separately. Three major experiments were carried out on a set of ABUS images. In experiment one, we focused on distinguishing malignant lesions (165 samples) from benign lesions (258 samples). In experiment two, we added a number of normal cases (150 samples) to the dataset, by grouping them with benign lesions against malignant lesions and by isolating them from benign and malignant lesions. In experiment three, we tested texture features ability on reducing false positives in the existing computer-aided detection system. In this step, only normal cases (5263 samples) and malignant lesions (165 samples) were examined. To estimate the discrimination power of different texture features, Support VectorMachine (SVM) and AdaBoost classifiers were adopted in corporation withleave-one-patient-out and 10-fold cross validation schemes respectively. The areaunder the receiver operator characteristic (ROC) curve (AUC, also known as Az)values were analyzed corresponding to each texture feature extraction method. TheAz values computed in experiment one are compared as follows: Haar-Like feature'sperformance outweighs others' with the Az value of 0.86, followed by LBP (0.84),RZM(0.81) and 3-D GLCM (0.75). With respect to the results from experiment two,the Az value of grouping normal cases with benign lesions against malignant lesions isbetter than separating them from benign and malignant lesions, in general. Regardingthe outcome from experiment three, the Az value was increased from 0.79 to 0.82after adding LBP and Haralick features to the existing computer-aided detectionsystem. Based on the overall results, we concluded that texture features are useful on classifying benign and malignant lesions in ABUS images and they can improve the performance of the existing computer-aided detection system on detecting breast cancers.

Стилі APA, Harvard, Vancouver, ISO та ін.

32

Muthukaruppan, Anita. "Gene expression analysis in breast cancer." Thesis, University of Auckland, 2011. http://hdl.handle.net/2292/6997.

Повний текст джерела

Анотація:

Breast cancer is a leading cause of malignancy worldwide. Improvements to gene expression profiling technology have resulted in the identification of many prognostic and predictive gene expression signatures for breast cancer. Whilst some of these signatures are being developed commercially, only two prognostic signatures: MammaPrint and Oncotype DX, are currently being validated in clinical trials. Many of these gene expression signatures require independent validation and the underlying biology behind these signatures remains unclear. The aim of this thesis is to identify key molecular pathways that are relevant in breast cancer using pathway and network analyses of new and existing in vivo and in vitro microarray gene expression data. The oestrogen signalling pathway was the main focus of this thesis due to its documented importance in the pathogenesis of breast cancer. Analyses of gene expression differences in New Zealand breast tumours according to oestrogen receptor (ER) status revealed differentially regulated genes such as ESR1, GATA3 and EGFR, which have also been reported in other breast cancer microarray studies. The analyses of a collaboratively assembled 960-tumour dataset of clinical breast cancer microarray data revealed differentially regulated pathways involving BCL2, ESR1, EGFR, MYC and NFKB between ER positive and negative tumours. We also identified a principal component of oestrogen activity using the gene expression data from our collated 960-tumour dataset, that could be used alongside ESR1 mRNA and ER protein expression (from immunohistochemistry) to stratify breast cancer patients more accurately. The generation of an in vitro siRNA perturbation dataset using MCF7 breast cancer cells, and its analyses using gene networks has identified relationships between genes that appear to operate both in vitro and in vivo. There were more highly correlated gene pairs shared between the MCF7 dataset and luminal A tumours than between this dataset and other tumour subtypes. The identification of key molecular pathways and master regulators operating in breast tumours from gene expression data may improve our understanding of the biology behind breast cancer. This knowledge can be used in the future to help integrate gene expression data with clinicohistopathological data to improve diagnostic and therapeutic decision-making for patients.

Стилі APA, Harvard, Vancouver, ISO та ін.

33

Walsh, Tomas. "Molecular analysis of early breast cancer." Thesis, University of Leicester, 1997. http://hdl.handle.net/2381/29525.

Повний текст джерела

Анотація:

Despite extensive research the pathways of breast cancer development remain largely unknown. The identification of key genetic alterations, particularly at the early stages of the disease, are central to elucidating the developmental pathways for this disease. Pure populations of tumour cells were microdissected from well defined groups of breast lesions, comprising: ductal carcinoma in situ (DCIS) tubular carcinomas, and mammographically-detected, impalpable early stage, moderately to well differentiated invasive carcinomas, and analysed for alterations in polymorphic tandem repetitive sequences (microsatellites). This enabled analysis of microsatellite instability (MI), which has been demonstrated to be indicative of a mutator phenotype in colorectal cancer, and loss of heterozygosity (LOH), which may indicate the presence of a tumour suppressor gene. MI was demonstrated to be a tumour specific alteration not present in benign proliferative disorders. It was present in 8 of 11 (73%) high grade lesions of DCIS, but only at a low frequency in low grade DCIS and invasive carcinomas and was absent from the tubular carcinomas. Two distinct types of alteration were observed: alterations to a single trinucleotide repeat (DM-1), and alterations of multiple microsatellite loci. Cases demonstrating this phenotype did not show alterations of candidate DNA repair genes (MSH2, MLH1 and PMS2), or in key cancer associated loci (TGFpRII, IGFIIR, Bax, and E2F-4), indicating that this phenotype is distinct to that described in colorectal tumours. LOH studies were focused on chromosome 16q21-24.4, a site for which there is evidence of alteration in the early stages of the disease. A high frequency of LOH (greater than 40%) was observed in all carcinomas. A candidate tumour suppressor gene, E-cadherin, mapping to this region, was not found to be mutated in these cases demonstrating LOH. In vivo experiments suggested that this gene could be silenced by aberrant methylation. In summary, MI was associated with high grade lesions, whereas LOH at 16q was observed at similar frequencies in all the carcinomas, possibly reflecting different roles in the development and progression of breast cancer.

Стилі APA, Harvard, Vancouver, ISO та ін.

34

Makriyianni, Ioli. "Mutation analysis of hereditary breast cancers." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=98760.

Повний текст джерела

Анотація:

Mitochondrial background. Recent studies on cancer have detected many mutations and much variability in the mitochondrial genome, particularly in the non-coding region (D-loop). The present study set out to sequence and examine the hypervariable region I (HVR-I) of the D-loop and transfer RNA Leucine (tRNA Leu) for mutations in breast cancer patients. Methods. Tumor and normal tissues from 17 patients that carry mutations in either BRCA1 (n = 11), BRCA2 (n = 3) or are non-carriers of mutations in either gene (n = 3) were examined by direct genomic sequencing of PCR products. Results. We found 44 variants in the HVR-I of 16 patients, twenty-six were polymorphisms, four somatic variants, and fourteen variations were undetermined because corresponding (unaffected) normal tissue was not available. One BRCA1 mutated tumor had four somatic tumor variants (1/14). All other BRCA1/BRCA2 mutated tumors had no somatic variants. Nine out of 14 (64%) of these patients had a total 22 germline variants. One out of three (33%) non-carriers had four germ-line variants. No variants were found in tRNA Leu. A five kilobase deletion was also found as a germ-line variant in two of seven (29%) patients. There were no obvious differences in the frequency of homoplasmic variants in the mitochondrial genome between the BRCA1/BRCA2 mutation carriers and non-carriers. Conclusion. Direct genomic sequencing of PCR products showed that there were no striking differences in homoplasmic variants between tumor and normal tissue, thus homoplasmic variants in mtDNA did not have a role in tumorigenesis in our samples. We speculate that the marked differences in mutation frequencies observed amongst various studies could be the result of differences in the techniques used to generate and analyze the data.
EGFR background. Recent studies have identified mutations in the tyrosine kinase (TK) domain of the epidermal growth factor receptor (EGFR) in lung carcinomas. These mutations make the tumors sensitive to a molecular targeted drug called getifinib. Methods. We also sequenced the TK domain of EGFR in 16 breast cancer patients (BRCA1 = 9, BRCA2 = 4, non-carriers = 3) for mutations. Results. We did not find mutations reported previously in lung carcinomas but we identified other variants, in exons 18, 20 and 21 of the mutation carvers. We found one out of thirteen (eight percent) of the BRCA1/BRCA2 mutation carriers had somatic tumor variants, three out of thirteen (23%) patients had somatic variants found only in the adjacent normal tissue, and four out of thirteen (31%) patients had germ-line variants. The non-carriers did not have any variants. The variants found in the exons were two missense variants in exon 18 of two patients, three 'silent' substitutions in exon 20 of three patients, and two patients had exon 21 variants; a missense variant and a 'silent' substitution. Intronic variants were also found in three patients. Patient 5420 harbored more than one variant in the tumor tissue and patient 5483 harbored more than one somatic variant in the adjacent normal tissue. Although the sample size is small, these preliminary results seem to show a difference in EGFR variants between BRCA1/BRCA2 mutation carriers and non-carriers. Conclusion . EGFR variants found in this study were not the same ones found in lung cancer, but other variants could be significant in breast cancer progression and could possibly represent drug targets for future therapy.

Стилі APA, Harvard, Vancouver, ISO та ін.

35

Amaral, Telmo. "Analysis of breast tissue microarray spots." Thesis, University of Dundee, 2010. https://discovery.dundee.ac.uk/en/studentTheses/0a83915d-2f11-4b89-9c24-8dc3c15346f2.

Повний текст джерела

Анотація:

Tissue microarrays (TMAs) are a high-throughput technique that facilitates the survey of very large numbers of tumours, important both in clinical and research applications. However, the assessment of stained TMA sections is laborious and still needs to be carried manually, constituting a bottleneck in the pathologist?s work-flow. This process is also prone to perceptual errors and observer variability.Thus, there is strong motivation for the development of automated quantitative analysis of TMA image data. The analysis of breast TMA sections subjected to nuclear immunostaining begins with the classification of each spot as to the maintype of tissue that it contains, namely tumour, normal, stroma, or fat. Tumour and normal spots are then assigned a so-called quickscore composed of a pair or integer values, the first reflecting the proportion of epithelial nuclei that are stained, and the second reflecting the strength of staining of those nuclei. In this work, an approach was developed to analyse breast TMA spots subjectedto progesterone receptor immunohistochemistry. Spots were classified into their four main types through a method that combined a bag of features approachand classifiers based on either multi-layer perceptrons or latent Dirichlet allocation models. A classification accuracy of 74.6 % was achieved. Tumour and normal spots were scored via an approach that involved the computation of global features formalising the quickscore values used by pathologists, and the use of Gaussian processes for ordinal regression to predict actual quickscores based on global features. Mean absolute errors of 0.888 and 0.779 were achieved in the prediction of the first and second quickscore values, respectively. By setting thresholds on prediction confidence, it was possible to classify and score fractions of spots with substantially higher accuracies and lower mean absolute errors. Amethod for the segmentation of TMA spots into regions of different types was also investigated, to explore the generative nature of latent Dirichlet allocation models.

Стилі APA, Harvard, Vancouver, ISO та ін.

36

Wilson, Kelly A. "Finite Element Analysis of Breast Implants." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/32972.

Повний текст джерела

Анотація:

The Breast Implant Lifetime Study at Virginia Tech, on which this thesis is based, seeks to develop methods and data for predicting the lifetime of saline-filled implants. This research developed Finite Element Analysis (FEA) models to evaluate the stresses that are present in the silicone breast implant material under different loading situations. The FEA work was completed using the commercial codes PATRAN and ABAQUS. PATRAN was used for pre- and post-processing, while ABAQUS was used for the actual analysis and to add fluid and contact elements not supported by PATRAN. Many different loading situations and constraints were applied to these models, as well as variations in the material and model properties. Varying the Poisson's ratio of the implant material from 0.45 to 0.49 did not make a significant difference in the results. Changing the elastic modulus of the implant material from the modulus of a Smooth implant to the modulus of a Siltex implant had a noticeable effect on the stress results, increasing the maximum stresses by almost 8%. Changing the modulus of the surrounding tissue had marked effects as well, with stiffer tissue (E=300 psi) decreasing the implant's stresses by about 60% as compared to softer tissue (E=100 psi). A ten percent decrease in implant thickness yielded a 17% average increase in stress experienced by the implant. For both the 2.5" radius and the 4" radius tissue models, using CAX4 elements produced higher overall stresses in the tissue with the same loading conditions. However, in the 2.5" tissue model, the implant itself experienced less stress with the CAX4 tissue than the CAX3 tissue. In the 4" tissue model, the implant experienced more stress when surrounded by the CAX4 tissue elements. These models will be combined with implant fatigue data to develop a life prediction method for the implant membrane.
Master of Science

Стилі APA, Harvard, Vancouver, ISO та ін.

37

Round, A. R. "Ultra-structural analysis of breast tissue." Thesis, Cranfield University, 2007. http://hdl.handle.net/1826/2057.

Повний текст джерела

Анотація:

Previous research has shown that diagnostic information could be obtained from small angle X-ray scattering from breast tissues. The observed differences were attributed to two possible causes, the production of a new type of collagen around tumours and the action of matrix metalloproteinases degrading the collagen around tumours. Using both synchrotron radiation and conventional X-ray sources data was collected to investigate these hypotheses. 225 X-ray scattering profiles were collected from breast tissue samples from 82 individual patients using synchrotron radiation. The differences between normal, malignant and benign tissues were investigated and structural differences in the collagen were determined. The effects of metalloproteinase action on collagen were also investigated and computer modelling was used to simulate the diffraction profiles from collagen with structural alterations. The structural differences in diseased tissues were attributed to a difference in the structure of collagen which was observed as a reduction in peak intensity and increased axial D spacing (0.3 nm increase in D period) compared to normal tissues. The differences between malignant and benign disease were attributed to metalloproteinase action degrading the collagen around tumours. Automatic classification was applied using principal component analysis to tissue samples from up to 6 cm away from the tumour site, approximately 90 % of the tissue samples at 6 cm were classified as cancer using the X-ray scattering profile but which were diagnosed as normal by standard histopathological methods. The results of this research have shown that X-ray scattering profiles contain diagnostic information relating to the structure of collagen. The changes associated with disease may be observed at up to 6 cm from the tumour site and that these differences in the X-ray scattering profile may be measured using a conventional X-ray source.

Стилі APA, Harvard, Vancouver, ISO та ін.

38

Liu, Zhenzhen. "Hydro-mechanical analysis of breach processes due to levee failure." Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4726/document.

Повний текст джерела

Анотація:

La rupture des barrages et des digues en terre est susceptible d’avoir des conséquences importantes en aval et dans les zones protégées. Nous avons mené une analyse hydro-mécanique de la formation et du développement de brèche destinée à améliorer la précision des approches actuelles. Dans le cas de l’érosion interne, un modèle d’agrandissement de conduit a été proposé pour modéliser la rupture des digues et barrages en terre par écoulement concentré. Ce modèle tient compte de l’érosion du sol par un écoulement de conduit turbulent. En ce qui concerne l’élargissement de la brèche, un modèle simple d’estimation de la longueur critique d’afouillement par “headcut” est proposé, fonction de la résistance du sol à la traction. Ce modèle est en bon accord avec les résultats numériques obtenus par équilibre limite. Un modèle simplifé pour la contrainte latérale sur les parois de la brèche a ensuite été proposé. Ce modèle tient compte des écoulements secondaires. Il montre que la contrainte latérale peut être plus grande que la contrainte de fond, suivant la situation. Finalement, une expérimentation de grande dimension de rupture de barrage par erosion de conduit a été modélisée avec le modèle d’érosion de conduit proposé, et quelques composantes des modèles d’élargissement de brèche proposés. L’élargissement de la brèche par paliers a été reproduite au début du processus. Les perspectives de validation et d'application des modèles proposés sont discutées
The failure of embankment dams and levees can have serious consequence in floodplains. Hydro-mechanical analyses of the breach processes were conducted to develop the accurate estimation of the failure of embankment dams and levees. Considering the internal erosion process, a pipe enlargement model was proposed to simulate the failure of embankment dams and levees by concentrated leak erosion. In this model, the turbulent pipe flow with erosion mechanism was employed as well as the soil erosion law. Considering the breach enlargement process, a simple headcut migration model based on the soil tensile strength was presented to simulate the critical length of the headcut. Good agreements were obtained by comparing with the limit equilibrium numerical model. A simple model was eventually proposed to simulate the lateral shear stress on the breach sides, accounting for the secondary flow. The lateral shear stress can be greater than the bottom shear stress, depending on the situation. . Finally, a large-scale test of dam failure was simulated by using the pipe enlargement and some components of the breach widening models proposed. The simulation of the pipe enlargement process had good agreement with the measured data. Both of the pipe diameter and the discharge flow were well simulated. The stepwise enlargement of the breach width was also well simulated at the beginning of the breach widening process. Validation and application prospects of the proposed models are discussed

Стилі APA, Harvard, Vancouver, ISO та ін.

39

Chow, Kam Kong. "A raman cell based on hollow core photonic crystal fibre for human breath analysis." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43593.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

40

Ama, Obinna Henry. "Novel K2W7O22/Ti3C2 Nanocomposite-Based Sensor Device for Breath Acetone Analysis in Diabetic Patients." Thesis, North Dakota State University, 2020. https://hdl.handle.net/10365/31828.

Повний текст джерела

Анотація:

Acetone in exhaled breath is gaining attention as a non-invasive means of quantifying blood glucose levels in Diabetics. This calls for development of novel biosensors for the detection of trace concentrations of acetone present in human breath. Traditional gas detection systems, such as GC/MS and chemiresistive sensors, are currently used for this purpose. However, these systems have limitations with regards to size, cost, and operating temperature. This work presents the K2W7O22/Ti3C2 nanocomposite sensor as breath acetone sensor that overcomes the limitations in traditional detection systems. Sensing experiments were conducted using 5 different sensor materials in varying ratios. KWO/Ti3C2 - ratio 2:1 (annealed) and KWO/Ti3C2 - ratio 2:1 (Unannealed) showed excellent sensitivity to 2.85ppm and 5.4ppm acetone concentration. These materials were then implemented in a prototype device. Material and device test results confirm the potentials of the novel KWO/Ti3C2 nanocomposite as a good sensor for breath acetone detection.

Стилі APA, Harvard, Vancouver, ISO та ін.

41

Thomas, Jessica Rose. "Assessment of the Applicability of Terahertz Spectroscopic Breath Sensing towards Monitoring Type 1 Diabetic Mellitus." Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1440613521.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

42

Hayton, Paul M. "Analysis of contrast-enhanced breast MR images." Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298777.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

43

de, Pasquale Francesco. "Analysis of dynamic magnetic resonance breast images." Thesis, University of Plymouth, 2004. http://hdl.handle.net/10026.1/2351.

Повний текст джерела

Анотація:

Dynamic Magnetic Resonance Imaging is a non-invasive technique that provides an image sequence based on dynamic information for locating lesions and investigating their structures. In this thesis we develop new methodology for analysing dynamic Magnetic Resonance image sequences of the breast. This methodology comprises an image restoration step that reduces random distortions affecting the data and an image classification step that identifies normal, benign or malignant tumoral tissues. In the first part of this thesis we present a non-parametric and a parametric approach for image restoration and classification. Both methods are developed within the Bayesian framework. A prior distribution modelling both spatial homogeneity and temporal continuity between neighbouring image pixels is employed. Statistical inference is performed by means of a Metropolis-Hastings algorithm with a specially chosen proposal distribution that out-performs other algorithms of the same family. We also provide novel procedures for estimating the hyper-parameters of the prior models and the normalizing constant so making the Bayesian methodology automatic. In the second part of this thesis we present new methodology for image classification based on deformable templates of a prototype shape. Our approach uses higher level knowledge about the tumour structure than the spatio-temporal prior distribution of our Bayesian methodology. The prototype shape is deformed to identify the structure of the malignant tumoral tissue by minimizing a novel objective function over the parameters of a set of non-affine transformations. Since these transformations can destroy the connectivity of the shape, we develop a new filter that restores connectivity without smoothing the shape. The restoration and classification results obtained from a small sample of image sequences are very encouraging. In order to validate these results on a larger sample, in the last part of the thesis we present a user friendly software package that implements our methodology.

Стилі APA, Harvard, Vancouver, ISO та ін.

44

Lee, Justin Wu. "Computational imaging and analysis in breast cancer." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/115703.

Повний текст джерела

Анотація:

Thesis: Ph. D. in Biomedical Engineering, Harvard-MIT Program in Health Sciences and Technology, 2018.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 125-136).
The conventional pathologic analysis of malignancies involves a qualitative characterization and integration of several factors including tumor size, general degree of differentiation, tumor heterogeneity, mitotic rate, and lymphovascular invasion. For some cancers, biomarkers such as hormone receptor expression or receptor kinase over-expression can provide additional prognostic and therapeutic guidance. Unfortunately, all of these qualitative histologic approaches, while generally accepted for directing patient care, often exhibit significant inter-observer variability resulting in inconsistent inter- and intra-institutional predictions of tumor behavior (including metastases and/or recurrence), resulting in incorrect diagnoses or treatment. Because cellular morphology is an integrated reflection of genetic and epigenetic expression, we hypothesize that a more accurate quantitative accounting and measurement of histologic features can provide a more robust and reliable prediction of tumor behavior. Computational imaging utilizes software to augment or replace the role of traditional optical elements in imaging systems and has an ability to significantly increase the accuracy, robustness and cost-efficiency of digital pathology. In this thesis, we develop and test three novel computational imaging algorithms including, to the best of our knowledge, the first system for lensless computational imaging through deep learning. We then test our hypothesis by applying augmented image retrieval, analysis algorithms, and machine learning on a validated dataset of breast cancer images where the clinical outcomes of the primary tumor are known. In particular, we analyze algorithms related to identifying mitoses as a central proof of concept.
by Justin Lee.
Ph. D. in Biomedical Engineering

Стилі APA, Harvard, Vancouver, ISO та ін.

45

Ashok, Mahima. "Analysis of HER2 testing in breast cancer." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29711.

Повний текст джерела

Анотація:

Thesis (Ph.D)--Biomedical Engineering, Georgia Institute of Technology, 2010.
Committee Chair: Griffin, Paul; Committee Member: Butera, Robert; Committee Member: Halpern, Michael; Committee Member: Nichols, Richard; Committee Member: Vidakovic, Brani. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Стилі APA, Harvard, Vancouver, ISO та ін.

46

Gabrovska, Plamena N. "Gene Expression Analysis in Human Breast Cancer." Thesis, Griffith University, 2012. http://hdl.handle.net/10072/367577.

Повний текст джерела

Анотація:

Breast Cancer is the most commonly diagnosed cancer in women, with more than 1.2 million women diagnosed annually worldwide. It is also a frequently fatal disease and remains difficult to treat, despite advances in all facets of cancer management. While a number of genetic mutations have been identified in human breast cancers, he specific combinations of the mutations required in concert for formation of a breast carcinoma remains unknown, making precise detection or prognostic predictions impossible. Although estrogen receptor (ER) status is predictive of response to hormonal treatments, there are currently no clinically useful predictive markers of a patient’s response to chemotherapy. This results in all patients who are eligible for chemotherapy receiving the same treatment even though de novo drug resistance will result in the treatment failing in about 80% of cases. Developing improved diagnostic tools to cluster different breast cancers into groups based on genetic parameters has the potential to revolutionise individualised treatment options and subsequent efficacy. This in turn will improve quality of life for patients undergoing therapy who will no longer suffer the consequences of unnecessary treatments and more importantly, a subsequent improved survival rate.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Medical Science
Griffith Health
Full Text

Стилі APA, Harvard, Vancouver, ISO та ін.

47

De, Biase Dario <1982&gt. "Molecular analysis of special type breast carcinomas." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2363/1/de_Biase_Dario__Tesi_Dottorato.pdf.

Повний текст джерела

Анотація:

The project was developed into three parts: the analysis of p63 isoform in breast tumours; the study of intra-tumour eterogeneicity in metaplastic breast carcinoma; the analysis of oncocytic breast carcinoma. p63 is a sequence-specific DNA-binding factor, homologue of the tumour suppressor and transcription factor p53. The human p63 gene is composed of 15 exons and transcription can occur from two distinct promoters: the transactivating isoforms (TAp63) are generated by a promoter upstream of exon 1, while the alternative promoter located in intron 3 leads to the expression of N-terminal truncated isoforms (ΔNp63). It has been demonstrated that anti-p63 antibodies decorate the majority of squamous cell carcinomas of different organs; moreover tumours with myoepithelial differentiation of the breast show nuclear p63 expression. Two new isoforms have been described with the same sequence as TAp63 and ΔNp63 but lacking exon 4: d4TAp63 and ΔNp73L, respectively. Purpose of the study was to investigate the molecular expression of N-terminal p63 isoforms in benign and malignant breast tissues. In the present study 40 specimens from normal breast, benign lesions, DIN/DCIS, and invasive carcinomas were analyzed by immunohistochemistry and RT-PCR (Reverse Transcriptase-PCR) in order to disclose the patterns of p63 expression. We have observed that the full-length isoforms can be detected in non neoplastic and neoplastic lesions, while the short isoforms are only present in the neoplastic cells of invasive carcinomas. Metaplastic carcinomas of the breast are a heterogeneous group of neoplasms which exhibit varied patterns of metaplasia and differentiation. The existence of such non-modal populations harbouring distinct genetic aberrations may explain the phenotypic diversity observed within a given tumour. Intra-tumour morphological heterogeneity is not uncommon in breast cancer and it can often be appreciated in metaplastic breast carcinomas. Aim of this study was to determine the existence of intra-tumour genetic heterogeneity in metaplastic breast cancers and whether areas with distinct morphological features in a given tumour might be underpinned by distinct patterns of genetic aberrations. 47 cases of metaplastic breast carcinomas were retrieved. Out of the 47 cases, 9 had areas that were of sufficient dimensions to be independently microdissected. Our results indicate that at least some breast cancers are composed of multiple non-modal populations of clonally related cells and provide direct evidence that at least some types of metaplastic breast cancers are composed of multiple non-modal clones harbouring distinct genetic aberrations. Oncocytic tumours represent a distinctive set of lesions with typical granular cytoplasmatic eosinophilia of the neoplastic cells. Only rare example of breast oncocytic carcinomas have been reported in literature and the incidence is probably underestimated. In this study we have analysed 33 cases of oncocytic invasive breast carcinoma of the breast, selected according to morphological and immunohistochemical criteria. These tumours were morphologically classified and studied by immunohistochemistry and aCGH. We have concluded that oncocytic breast carcinoma is a morphologic entity with distinctive ultrastructural and histological features; immunohistochemically is characterized by a luminal profile, it has a frequency of 19.8%, has not distinctive clinical features and, at molecular level, shows a specific constellation of genetic aberration.

Стилі APA, Harvard, Vancouver, ISO та ін.

48

De, Biase Dario <1982&gt. "Molecular analysis of special type breast carcinomas." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2363/.

Повний текст джерела

Анотація:

The project was developed into three parts: the analysis of p63 isoform in breast tumours; the study of intra-tumour eterogeneicity in metaplastic breast carcinoma; the analysis of oncocytic breast carcinoma. p63 is a sequence-specific DNA-binding factor, homologue of the tumour suppressor and transcription factor p53. The human p63 gene is composed of 15 exons and transcription can occur from two distinct promoters: the transactivating isoforms (TAp63) are generated by a promoter upstream of exon 1, while the alternative promoter located in intron 3 leads to the expression of N-terminal truncated isoforms (ΔNp63). It has been demonstrated that anti-p63 antibodies decorate the majority of squamous cell carcinomas of different organs; moreover tumours with myoepithelial differentiation of the breast show nuclear p63 expression. Two new isoforms have been described with the same sequence as TAp63 and ΔNp63 but lacking exon 4: d4TAp63 and ΔNp73L, respectively. Purpose of the study was to investigate the molecular expression of N-terminal p63 isoforms in benign and malignant breast tissues. In the present study 40 specimens from normal breast, benign lesions, DIN/DCIS, and invasive carcinomas were analyzed by immunohistochemistry and RT-PCR (Reverse Transcriptase-PCR) in order to disclose the patterns of p63 expression. We have observed that the full-length isoforms can be detected in non neoplastic and neoplastic lesions, while the short isoforms are only present in the neoplastic cells of invasive carcinomas. Metaplastic carcinomas of the breast are a heterogeneous group of neoplasms which exhibit varied patterns of metaplasia and differentiation. The existence of such non-modal populations harbouring distinct genetic aberrations may explain the phenotypic diversity observed within a given tumour. Intra-tumour morphological heterogeneity is not uncommon in breast cancer and it can often be appreciated in metaplastic breast carcinomas. Aim of this study was to determine the existence of intra-tumour genetic heterogeneity in metaplastic breast cancers and whether areas with distinct morphological features in a given tumour might be underpinned by distinct patterns of genetic aberrations. 47 cases of metaplastic breast carcinomas were retrieved. Out of the 47 cases, 9 had areas that were of sufficient dimensions to be independently microdissected. Our results indicate that at least some breast cancers are composed of multiple non-modal populations of clonally related cells and provide direct evidence that at least some types of metaplastic breast cancers are composed of multiple non-modal clones harbouring distinct genetic aberrations. Oncocytic tumours represent a distinctive set of lesions with typical granular cytoplasmatic eosinophilia of the neoplastic cells. Only rare example of breast oncocytic carcinomas have been reported in literature and the incidence is probably underestimated. In this study we have analysed 33 cases of oncocytic invasive breast carcinoma of the breast, selected according to morphological and immunohistochemical criteria. These tumours were morphologically classified and studied by immunohistochemistry and aCGH. We have concluded that oncocytic breast carcinoma is a morphologic entity with distinctive ultrastructural and histological features; immunohistochemically is characterized by a luminal profile, it has a frequency of 19.8%, has not distinctive clinical features and, at molecular level, shows a specific constellation of genetic aberration.

Стилі APA, Harvard, Vancouver, ISO та ін.

49

Schardl, Tao Benjamin. "Design and analysis of a nondeterministic parallel breadth-first search algorithm." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/61575.

Повний текст джерела

Анотація:

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 75-77).
I have developed a multithreaded implementation of breadth-first search (BFS) of a sparse graph using the Cilk++ extensions to C++. My PBFS program on a single processor runs as quickly as a standard C++ breadth-first search implementation. PBFS achieves high workefficiency by using a novel implementation of a multiset data structure, called a "bag," in place of the FIFO queue usually employed in serial breadth-first search algorithms. For a variety of benchmark input graphs whose diameters are significantly smaller than the number of vertices - a condition met by many real-world graphs - PBFS demonstrates good speedup with the number of processing cores. Since PBFS employs a nonconstant-time "reducer" - a "hyperobject" feature of Cilk++ - the work inherent in a PBFS execution depends nondeterministically on how the underlying work-stealing scheduler load-balances the computation. I provide a general method for analyzing nondeteriministic programs that use reducers. PBFS also is nondeterministic in that it contains benign races which affect its performance but not its correctness. Fixing these races with mutual-exclusion locks slows down PBFS empirically, but it makes the algorithm amenable to analysis. In particular, I show that for a graph G = (V, E) with diameter D and bounded out-degree. this data-race-free version of PBFS algorithm runs in time O((V +E)/P+DIg[supercript 3] (V/D)) on P processors, which means that it attains near-perfect linear speedup if P < (V +E)/DIg[supercript 3] (V/D).
by Tao Benjamin Schardl.
M.Eng.

Стилі APA, Harvard, Vancouver, ISO та ін.

50

McGill, Matthew C. "An Analysis of Contracting and Breach Decisions Under Various Damage Remedies." Ohio University Honors Tutorial College / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ouhonors1492777267852137.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Дисертації з теми "Breath analysi"

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями