This thesis presents the hedging theory and its application in order to create an optimal hedging strategy for Retal Industries Ltd. on the PET market. Through this work the hedging theory is tested and assessed basing on its relevance for actual business needs.

Although motion correction in medical imaging is well established and has attracted much interest and research funding, a gap still exists in that there is a lack of reliable, low-cost hardware to enable such techniques to be widely adopted in healthcare. Motion correction of brain Positron Emission Tomography (PET) data for instance is an important step in realising the potential offered by modern high resolution PET scanners. Since it is not likely that subjects can remain stationary throughout the PET scan, which can last 60 minutes or more, accurate and reliable motion tracking is needed to correct the PET data for any observed motion. A commercially available marker based motion tracking system was evaluated and found to produce unreliable data. This was due to the possibility of the tracking tool slipping from the subject. This thesis describes the investigations into alternative and novel tracking techniques for use in PET. These included a markerless tracking system using the Microsoft Kinect (a low cost depth sensor) as well as a multiple target marker tracking system. The performance characteristics of both systems (low cost, high spatial and temporal accuracy, and real-time operation) were evaluated using phantom and clinical experiments. Investigations into using these two tracking techniques in whole body PET, specifically measuring the respiratory rate during lung imaging, were developed and compared against current commercially available solutions.

abstract: Positron emission tomography (PET) is a non-invasive molecular imaging technique widely used for the quantification of physiological and biochemical processes in preclinical and clinical research. Due to its fundamental role in the health care system, there is a constant need for improvement and optimization of its scanner systems and protocols leading to a dedicated active area of research for PET. (Geant4 Application for Tomographic Emission (GATE) is a simulation platform designed to model and analyze a medical device. Monte Carlo simulations are essential tools to assist in optimizing the data acquisition protocols or in evaluating the correction methods for improved image quantification. Using GATE along with Customizable and Advanced Software for Tomographic Reconstruction (CASToR), provides a link to reconstruct the images. The goal of this thesis is to learn PET systems that involve Monte Carlo methods, GATE software, CASToR software to model, simulate and analyze PET systems using three clinical PET systems as a template. Fluorine-18 radioisotope source is used to perform measurements on the modeled PET systems. Parameters such as scatter-fraction, random-fraction, sensitivity, count rate performance, signal to noise ratio (SNR), and time of flight (ToF) are analyzed to determine the performance of the systems. Also, the simulated data are provided as input to CASToR software and Amide's a Medical Image Data Examiner (AMIDE) tool to obtain the reconstructed images which are used to analyze the reconstruction capability of the simulated models. The Biograph Vision PET model has high sensitivity (11.159 cps/MBq) and SNR (12.556) while the Ultra-High Resolution (UHR) PET model has high resolution of the reconstructed image. / Dissertation/Thesis / Masters Thesis Computer Engineering 2020

The aim of this thesis was to develop and validate prognostic and predictive biomarkers in order to better identify among patients with metastatic colorectal cancer those at high-risk of early death or progression. The interest in developing such biomarkers is that their subsequent use in clinical practice would avoid exposing a patient for months to the toxic side effects of ineffective and expensive treatments, and thus to limit the financial impact of these treatments on our healthcare systems.The projects carried out in the framework of this thesis have shown that:The biomarker WB-MATV (metabolically active tumor volume of the whole body) measured before the start of the last line treatment has a high prognostic value, higher than the general clinical parameters commonly used. This biomarker was then validated in first line treatment and was shown to have a high prognostic value, also higher than the general clinical parameters.The biomarker cfDNA (circulating DNA) also representing the tumor load was then investigated to assess its value added to the previously validated WB-MATV. We showed that the presence of high levels of cfDNA before starting the last-line treatment is significantly associated with poor prognosis and that these two biomarkers are prognostically complementary, each providing an added value.The biomarker of early metabolic response to last line treatment has a high negative predictive value (95%). This biomarker was then validated as a predictive biomarker independent of WB-MATV and clinical factors in first-line treatment setting.In conclusion, the results of this thesis strongly support the clinical use of these prognostic and predictive biomarkers in patients with metastatic colorectal cancer. Allowing a more accurate stratification of patients, the use of the combination of these biomarkers should become an essential tool to help oncologists in tailoring therapeutic strategies according to the patients’ individual risk. / Doctorat en Sciences médicales (Médecine) / info:eu-repo/semantics/nonPublished

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第18866号 / 医博第3977号 / 新制||医||1008(附属図書館) / 31817 / 京都大学大学院医学研究科医学専攻 / (主査)教授 戸井 雅和, 教授 平岡 眞寛, 教授 三森 経世 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

In an effort to increase the thermodynamic stability and the kinetic inertness of the complexes, the five new azamacrobicyclic ligands derived from TACN, cyclen, and cyclam have been prepared. The ligands were decorated with phosphinate or phosphonate pendant arms to maintain fast complexation. Since the ascending importance of targeted diagnostic and therapy, the bone-targeted non-bridged cyclam derivative with phosphinate-bis(phosphonate) pendant arm (H5TE1PBP) has also been synthesized. The ligands were studied with respect to their application. The bridged TACN (H2bpbtacn) and cyclen (H4bpbcen) ligands show high macrocyclic basicity (logK1 = 12.25 and 12.70, respectively). The thermodynamic stability of H2bpbtacn with Cu(II) ion is more than ten orders of magnitude lower than that of the NOTA ligand. The stability constants of H4bpbcen with Cu(II) and Zn(II) ions are comparable to those given for the DOTA. The stability of Ln(III)-bpbcen complexes is 7-10 orders of magnitude lower compared to DOTA complexes. For both ligands, the lower thermodynamic stability of the complexes is attributed to the high rigidity of the ligand structure. The bridged cyclam derivatives with phosphonate (H4TE2P), bis(phosphinate) (H4TE2bpin), or phosphinate (H2TE2PH) pendants are characterized by high stability of...

In-beam positron emission tomography (in-beam PET) is currently the only method for an in-situ monitoring of highly tumor-conformed charged hadron therapy. In such therapy, the clinical effect of deviations from treatment planning is highly minimized by implementing safety margins around the tumor and selecting proper beam portals. Nevertheless, in-beam PET is able to detect eventual, undesirable range deviations and anatomical modifications during fractionated irradiation, to verify the accuracy of the beam portal delivered and to provide the radiotherapist with an estimation of the difference in dosage if the treatment delivered differs from the planned one. In a first study within this work, a set of simulation and fully-3D reconstruction routines shows that minimizing the opening angle of a cylindrical camera is determinant for an optimum quality of the in-beam PET images. The study yields two favorite detector geometries: a closed ring or a dual-head tomograph with narrow gaps. The implementation of either detector geometry onto an isocentric, ion beam delivery (gantry) is feasible by mounting the PET scanner at the beam nozzle. The implementation of an in-beam PET scanner with the mentioned detector geometries at therapeutic sites with a fixed, horizontal beam line is also feasible. Nevertheless, knowing that previous in-beam PET research in Berkeley was abandoned due to detector activation (Bismuth Germanate, BGO), arising most probably from passive beam shaping contaminations, the proposed detector configurations had to be tested in-beam. For that, BGO was substituted with a state-of-the-art scintillator (lutetium oxyorthosilicate, LSO) and two position sensitive detectors were built. Each detector contains 32 pixels, consisting of LSO finger-like crystals coupled to avalanche photodiode arrays (APDA). In order to readout the two detectors operated in coincidence, either in standalone mode or at the GSI medical beam line, a multi-channel, zero-suppressing free, list mode data acquisition system was built.The APDA were chosen for scintillation detection instead of photomultiplier tubes (PMT) due to their higher compactness and magnetic field resistance. A magnetic field resistant detector is necessary if the in-beam PET scanner is operated close to the last beam bending magnet, due to its fringe magnetic field. This is the case at the isocentric, ion beam delivery planned for the dedicated, heavy ion hospital facility under construction in Heidelberg, Germany. In-beam imaging with the LSO/APDA detectors positioned at small target angles, both upbeam and downbeam from the target, was successful. This proves that the detectors provide a solution for the proposed next-generation, improved in-beam PET scanners. Further confirming this result are germanium-detector-based, spectroscopic gamma-ray measurements: no scintillator activation is observed in patient irradiation conditions. Although a closed ring or a dual-head tomograph with narrow gaps is expected to provide improved in-beam PET images, low count rates in in-beam PET represent a second problem to image quality. More importantly, new accelerator developments will further enhance this problem to the point of making impossible in-beam PET data taking if the present acquisition system is used. For these reasons, two random-suppression methods allowing to collect in-beam PET events even during particle extraction were tested. Image counts raised almost twofold. This proves that the methods and associated data acquisition technique provide a solution for next-generation, in-beam positron emission tomographs installed at synchrotron or cyclotron radiotherapy facilities.

No description available.

<p>Ispitivanje uticaja personalnih karakteristika davaoca usluga (osobine ličnosti i<br />moral) na procenu kvaliteta usluge od strane korisnika usluga i procenu performansi<br />preduzeća (rekreacionih cenrara) pokazalo je da personalne karakteristike davaoca<br />usluge direktno utiču na kvalitet usluge i performanse.</p> / <p>An examination of the impact of the personal characteristics of the service provider<br />(personality traits and morale) on the assessment of the quality of service by the<br />service users and the assessment of the performance of the company (recreational<br />centers) showed that the personal characteristics of the service provider directly<br />affect the quality of service and performance.</p>

Adobe is a building material that has been used since ancient times, but is not as widely used as clay bricks or concrete for housing construction. In addition, it uses a construction technique that has been passed down and improved from generation to generation. In view of this, the present work aims to improve the properties of adobe by using PET bottle fibers in its composition. A mechanical test and two physical tests were carried out for adobe with 0% (standard adobe), 2%, 4% and 6% PET fibers, where it was observed that the adobe with 6% PET fibers obtained the best results, since it increased the compressive strength of the adobe by 19%, reduced the absorption percentage by 12% and finally reduced the density by 16.4%. Therefore, the addition of PET fibers in adobe is recommended, as it contributes to improve its mechanical and physical properties. Additionally, it reduces pollution in streets, rivers, parks, etc. because it promotes the recycling of PET bottles.