<p>A Positive Electron Tomography/Computed Tomography devise was installed in the X-ray section at US Linköping in May 2007. Positive Electron Tomography examinations with 18F-fluoro-deoxyglucose are mainly used for tumor examinations. During 2007 occurred approximately 200 examinations and in 2008 600 are planned.Today there are two reconstruction methods commercially available, Filtered Back projection and Maximum Likelihood Expectation Maximiza tion, used in the faster version called Ordered Subsets Expectation Maximization. The image quality in Positive Electron Tomography depends on the choice of reconstruction method and the settings of its parameters. We have performed a physical phantom study with Positive Electron Tomography to determine optimal parameters for the iterativereconstruction algorithm Ordered Subsets Expectation Maximization. To find out whether or not the quality of the image can be improved, so that the patient received radiation dose and/or examination time can be lowered. The phantom used was a NEMA IEC Body PhantomTM, designed to mimic small hot lesions typicalin 18F, Fluorine-18 PET, and all calculations were done according to the NEMA NU2-2001 protocol.</p><p>The main conclusion from this project is that a higher level of contrastcan be reached, compared to the one clinically obtained today. Using more iterations then recommended from the manufacturer.</p>

Optimization of Affibody molecules would allow for high contrast imaging of cancer associated surface receptors using molecular imaging. The primary aim of the thesis was to develop Affibody-based PET imaging agents to provide the highest possible sensitivity of RTK detection in vivo. The thesis evaluates the effect of radiolabelling chemistry on biodistribution and targeting properties of Affibody molecules directed against HER2 and PDGFRβ. The thesis is based on five published papers (I-V). Paper I. The targeting properties of maleimido derivatives of DOTA and NODAGA for site-specific labelling of a recombinant HER2-binding Affibody molecule radiolabelled with 68Ga were compared in vivo. Favourable in vivo properties were seen for the Affibody molecule with the combination of 68Ga with NODAGA. Paper II. The aim was to compare the biodistribution of 68Ga- and 111In-labelled HER2-targeting Affibody molecules containing DOTA, NOTA and NODAGA at the N-terminus. This paper also demonstrated favourable in vivo properties for Affibody molecules in combination with 68Ga and NODAGA placed on the N-terminus. Paper III.  The influence of chelator positioning on the synthetic anti-HER2 affibody molecule labelled with 68Ga was investigated. The chelator DOTA was conjugated either at the N-terminus, the middle of helix-3 or at the C-terminus of the Affibody molecules. The N-terminus placement provided the highest tumour uptake and tumour-to-organ ratios. Paper IV. The aim of this study was to evaluate if the 68Ga labelled PDGFRβ-targeting Affibody would provide an imaging agent suitable for PDGFRβ visualization using PET. The 68Ga labelled conjugate provided high-contrast imaging of PDGFRβ-expressing tumours in vivo using microPET as early as 2h after injection. Paper V. This paper investigated if the replacement of IHPEM with IPEM as a linker molecule for radioiodination of Affibody molecules would reduce renal retention of radioactivity. Results showed that the use of the more lipophilic linker IPEM reduced the renal radioactivity retention for radioiodinated Affibody molecules. In conclusion, this thesis clearly demonstrates that the labelling strategy is of great importance with a substantial influence on the targeting properties of Affibody molecules and should be taken under serious considerations when developing new imaging agents.

A new wall construction technique utilizing concrete filled PVC tubes, adobe, polyethylene terephthalate (PET) plastic bottles and cabling was designed, analyzed and implemented. The system was designed as an alternative to traditional earthen buildings in Honduras that are vulnerable to hurricane winds and seismic activity. Six prototype panels were constructed at the Alternative Village located at the University of Manitoba to evaluate the wall system for racking and transverse load capacity. A kitchen was then constructed at an elementary school in western Honduras. / October 2015

The effect of various inorganic and organic additives as possible nucleating agents on the crystallisation behaviour of P. E. T. and the suosequent influence on the morphological and mechanical properties has been examined. Various methods of mixing(: the polymer and additive were investigated and a method involving the screw-Extrusion of the polymer and the additive was ultimately adopted. Crystallisation studies were carried out using differential scanning calorimetry under dynamic and isothermal modes. The results produced under conditions of isothermal crystallisation were analysed by means of a computer. Despite differences between batches of polymer all the additives with the exception of indigo produced a nucleating effect in the polymer as indicated by an increase in the rate of crystallisation compared with that of the base polymer. Two organo-metallic substances (sodium benzoate and sodium stearate) proved to be the most effective in this respect by decreasing the degree of supercooling of the polymer by 20 [degrees]. Morphological studies were carried out on isothermally crystallised samples, after etching and replication using a transmission electron microscope. A nodular structure whose dimensions were sensitive to both the nucleating agent and the temperature of crystallisation was observed. Mechanical testing of samples direct from the D. S. C. was carried out using a compression method. The breaking loads were found to vary with both the type of nucleating agent used and the crystallisation temperature chosen. A separate study involving the exanination of the resulting fracture surfaces by scanning electron microscopy revealed that a, high breaking load was associated with a fine discontinuous structure whereas lower breaking loads were characterised by a more continuous linear appearance. This implies a higher energy of fracture due to the increased surface area of the fracture surface of the former.

The criteria for diagnosing Alzheimer’s disease (AD) have recently been revised to include the use of biomarkers for the in vivo presence of β-amyloid, one of the neuropathological hallmarks of AD. Examples of such biomarkers are positron emission tomography (PET) β-amyloid specific ligands, including [18F]flutemetamol. The aim of this thesis was to characterize the binding properties of [18F]flutemetamol from a tracer kinetic perspective as well as by validating binding measures through comparison with tissue pathology assessments. The applicability of previously developed kinetic models of tracer binding for voxel-based analysis was examined and compared to arterial input compartment modelling, the “gold standard” for PET quantification. Several voxel-based methods were found to exhibit high correlations with compartment modelling, including the semi-quantitative standardized uptake value ratio (SUVR). The kinetic components of [18F]flutemetamol uptake were also investigated without model assumptions using the data driven method spectral analysis, with binding to β-amyloid shown to relate to a slow kinetic component. The same component was also found to predominate in the uptake of white matter, known to be free of β-amyloid accumulation. White matter uptake was however possible to separate from β-amyloid binding based on the relative contribution of the slow component to the total volume of distribution. Uptake of [18F]flutemetamol as quantified using SUVR or assessed visually was found to correlate well with tissue pathology assessments. Classifying the brains of 68 deceased subjects who had undergone [18F]flutemetamol PET scanning ante mortem, based on the spatial distribution of β-amyloid according to pre-defined phases, revealed that abnormal uptake patterns of [18F]flutemetamol were only certain to be found in the last phase of β-amyloid accumulation. In the same cohort however, [18F]flutemetamol was also shown to accurately distinguish between subjects with AD and non-AD dementia. While this supports the use of [18F]flutemetamol in clinical settings for ruling out AD, the association of abnormal [18F]flutemetamol uptake to late phases of β-amyloid accumulation may limit the detection of early accumulation and pre-clinical stages of AD. It remains to be investigated whether application of voxel-based methods and slow component filtering may increase sensitivity, particularly in the context of clinical trials.

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Då hunden har blivit en allt större del i människans liv och är en växande målgrupp, vill vi undersöka hur svenska hundägare ser på att resa med sin hund inom Sverige, speciellt vad de har för åsikter om hundvänliga hotell. Den data vi har samlat in är från en enkätundersökning gjord på 522 hundägare i Sverige. Vårt huvudsakliga mål med denna studie är att se om det finns en marknad för fler hundvänliga hotell i Sverige och hur kommunikationen mellan hotellen och hundägarna fungerar. Vi tror att hotellen kan dra nytta av resultatet från denna studie. Resultatet visar på att det finns ett behov av fler hundvänliga hotell i Sverige. Dock verkar det största problemet ligga i kommunikationen mellan hotellen och hundägarna. Eftersom hundägarna känner att det finns en brist i informationen, om vilka hotell som tillåter hundar. En lösning på detta problem skulle kunna vara att göra en internationell symbol, som visar ifall ett hotell är hundvänligt eller inte. / Since the dog is becoming a more important role in the life of humans and is a growing target group, our research will examine how dog owners feel about traveling with their dogs in Sweden, in particularly staying at dog friendly hotels. The data we have collected is from a survey done on 522 dog owners in Sweden. Our main goal with this study is to see if there is a market for more dog friendly hotels in Sweden and how the communication between the hotels and the dog owners is working. We believe that the hotels can benefit from the results of this study. The result shows that there is a need for more dog friendly hotels in Sweden. However the main problem seems to be the communication between the hotels and the dog owners. Since the dog owners feel that there is a lack of information, about which hotels are allowing dogs. A solution to this problem could be to make an international symbol, which will show if a hotel is dog friendly or not.

Vasculogenic cell-based therapy combined with tissue engineering is a promising revascularization strategy for patients with hibernating myocardium, a common clinical condition. We used a clinically relevant swine model of hibernating myocardium to examine the benefits of biopolymer-supported delivery of circulating angiogenic cells (CACs) in this context. Twenty-five swine underwent placement of an ameroid constrictor on the left circumflex artery (LCx). After 2 weeks, positron emission tomography measures of myocardial blood flow (MBF) and myocardial flow reserve (MFR) were reduced in the affected region (both p<0.001). Hibernation (mismatch) was specific to the LCx territory. Swine were randomized to receive intramyocardial injections of PBS control (n=10), CACs (n=8), or CACs + a collagen-based matrix (n=7). At follow-up, stress MBF and MFR were increased only in the cells+matrix group (p<0.01), and mismatch was lower in the cells+matrix treated animals (p=0.02) compared to controls. Similar results were found using microsphere-measured MBF. Wall motion abnormalities and ejection fraction improved only in the cells+matrix group. This preclinical swine model demonstrated ischemia and hibernation, which was improved by the combined delivery of CACs and a collagen-based matrix. To our knowledge, this is the first demonstration of the mechanisms and effects of combining progenitor cells and biopolymers in the setting of myocardial hibernation, a common clinical condition in patients with advanced coronary artery disease.