The aim of the study was to investigate if PRIMA-1, a drug that reactivate the tumour suppressor gene p53, will have a synergistic effect when used in combination with γ-irradiation in a human small cell lung cancer cell line (U-1690), which show a low-dose hypersensitivity in clonogenic survival experiments. Clonogenic cell survival after incubation with PRIMA-1 alone in concentrations from 0.1 to 30 µM or in combination with γ-irradiation with a 137Cs source was performed. The standard LQ model, and the repairable-conditionally repairable damage model, the RCR model, were fitted to the experimental data. PRIMA-1 showed a time and concentration dependent cytotoxic, and 10 µM killed 60 % of cells during 72 hours incubation. The cells show low-dose hypersensitivity calculated with the RCR model. The combined treatment with 8 µM PRIMA-1 had a synergistic effect with irradiation doses from 2 Gy and above. The overall conclusion is that a combination with PRIMA-1 and irradiation is beneficial to achieve the best effect.

Det är skolans uppgift att utveckla och stimulera både det vardagliga- och vetenskapliga tänkandet hos elever. Utifrån konstruktivismen ska lärande anpassas till det stadium som elever befinner sig i, för att de ska ha möjlighet att konstruera föreställningar och förståelse av omvärlden. Att som lärare ha förståelse för de föreställningar elever har är därav viktigt för att förbättra undervisningen. Syftet med studien är att undersöka samt analysera elevers föreställningar om vad elektricitet är och hur de förklarar fenomenet, i jämförelse med hur läromedel anpassade för eleverna förklarar fenomenet. För att besvara frågeställningarna genomfördes semistrukturerade gruppintervjuer med 12 elever i fem grupper för att ta reda på deras föreställningar. Det genomfördes även en innehållsanalys av två läromedel för att ta reda på vilka begrepp de använder för att beskriva elektricitet. Resultatet visar att eleverna har skilda föreställningar om vad elektricitet är och att de använder många av de mest frekventa begreppen från läromedlen. Dessa begrepp är: batteri, elektricitet, elektron, lampa, sladd samt ström. Av dessa begrepp är det elektron som används i mindre utsträckning hos eleverna.

A small report on modelling an electrolyte flow-battery using the software COMSOL.

Structure determination of proteins is vital for the understanding of their function. It often relies on techniques that use intense X-ray pulses to create diffraction patterns of protein crystals, which then contain information on the three-dimensional structure of the crystallised protein. An emerging technique called Single Particle Imaging (SPI) aims to make possible the structure determination without the need for crystallisation of the proteins, by taking diffraction patterns from many individual proteins. Translating the diffraction patterns to spatial geometry is a daunting task that requires sophisticated algorithms which are not always able to determine the structure because of fundamental uncertainties in the recovery process. To improve the structure determination process, one can try to rotate the protein to a known orientation using electric fields before the measurement takes place. However, as a result of how these experiments are performed, the proteins may have water around them during this orientation phase. Using molecular dynamics (MD) on ubiquitin, a small protein found in all eukaryotic cells, it is shown that a layer of water around a protein does not only help to achieve orientation faster (compared to an identical protein without this layer), the water also provides the protein with increased structural stability.

Recently, there has been an increase in the number of proton beam therapy (PBT) centers operating worldwide. For certain cases, proton beams have been shown to provide dosimetric and radiobiological advantages when used for cancer treatment, compared to the regular photon-beam based treatments. Under ideal circumstances, the dose given to the tissues surrounding a target can be reduced with PBT. The risk for side effects following treatment is then expected to decrease. Until present, mainly stationary targets, e.g. targets in the brain, have been treated with PBT. There is currently a growing interest to treat also target volumes in other parts of the body with PBT. However, there are sources of uncertainties, which must be more carefully considered when PBT is used, especially for PBT carried out with scanned proton beams. PBT is more sensitive to anatomical changes, e.g. organ motion or a variable gas content in the intestines, which requires that special precautions are taken prior to treating new tumour sites. In photon beam radiotherapy (RT) of moving targets, the main consequence of organ motion is the loss of sharpness of the dose gradients (dose smearing). When scanned proton beams are used, dose deformation caused by the fluctuations in the proton beam range, due to varying tissue heterogeneities (e.g., the ribs moving in and out of the beam path) and the so-called interplay effect, can be expected to impact the dose distributions in addition to the dose smearing. The dosimetric uncertainties, if not accounted for, may cause the planned and accurately calculated dose distribution to be distorted, compromising the main goal of RT of achieving the maximal local disease control while accepting certain risks for normal tissue complications. Currently there is a lack of clinical follow-up data regarding the outcome of PBT for different tumour sites, in particular for extra-cranial tumour sites in moving organs. On the other hand, the use of photon beams for this kind of cancer treatment is well-stablished. A treatment planning comparison between RT carried out with photons and with protons may provide guidelines for when PBT could be more suitable. New clinical applications of particle beams in cancer therapy can also be transferred from photon-beam treatments, for which there is a vast clinical experience. The evaluation of the different uncertainties influencing RT of different tumour sites carried out with photon- and with proton-beams, will hopefully create an understanding for the feasibility of treating cancers with scanned proton beams instead of photon beams. The comparison of two distinct RT modalities is normally performed by studying the dosimetric values obtained from the dose volume histograms (DVH). However, in dosimetric evaluations, the outcome of the treatments in terms of local disease control and healthy tissue toxicity are not estimated. In this regard, radiobiological models can be an indispensable tool for the prediction of the outcome of cancer treatments performed with different types of ionising radiation. In this thesis, different factors that should be taken into consideration in PBT, for treatments influenced by organ motion and density heterogeneities, were studied and their importance quantified. This thesis consists of three published articles (Articles I, II and III). In these reports, the dosimetric and biological evaluations of photon-beam and scanned proton-beam RT were performed and the results obtained were compared. The studies were made for two tumour sites influenced by organ motion and density changes, gastric cancer (GC) and liver metastases. For the GC cases, the impact of changes in tissue density, resulting from variable gas content (which can be observed inter-fractionally), was also studied. In this thesis, both conventional fractionations (implemented in the planning for GC treatments) and hypofractionated regimens (implemented in the planning for the liver metastases cases) were considered. In this work, it was found that proton therapy provided the possibility to reduce the irradiations of the normal tissue located near the target volumes, compared to photon beam RT. However, the effects of density changes were found to be more pronounced in the plans for PBT. Furthermore, with proton beams, the reduction of the integral dose given to the OARs resulted in reduced risks of treatment-induced secondary malignancies.

No description available.

In this thesis we study a particular realization of the Domain wall/Quantum Field Theory correspondence, a modification of the Anti de-Sitter/Conformal Field Theory correspondence that is used to study deformations of a Conformal Field Theory. In theQuantum gravity side of the duality we analyze a N = 1 gauged supergravity theory in 7 dimensions which presents two different Anti de-Sitter vacua, one of which preserves the full supersymmetry and one that breaks half of the supercharges. We will find a scalar 1/2-BPS solitonic solution describing a domain wall in an asymptotically Anti de-Sitter spacetime which interpolates between the supersymmetric AdS vacuum and a divergent AdS space situated at infinity, and we will calculate its tension and the effective mass of the scalar field when evaluated at the AdS vacuum. The dual theory of our gauged  supergravity is the 6-dimensional N = (1,0) Superconformal Field Theory, and the scalar 1/2-BPS field is dual to two relevant operators that induce a relevant deformation of the SCFT which can be identified with a renormalization group-flow. Here we will first compute the scaling dimension and the one-point functions of these operators in the SCFT, as well as indicating how to compute the two-point and three-point functions, and then we will study the c-function along the renormalization group-flow they induce and the beta function that characterizes this flow in order to derive some properties of the resulting Quantum Field Theory.

There is an increasing interest in using new composite materials in microwave devices, to reduce size and weight while maintaining similar performances. A new promising material group is named magneto-dielectric materials, which have the permittivity and permeability values both larger than one. Compared to the commercially used dielectric materials, magneto-dielectric materials can achieve a larger miniaturization factor with the equivalent properties as dielectric materials. There is a very limited availability of commercial magneto-dielectric materials. A recent addition was from Rogers Corporation with MAGTREX 555, [1], that is available as a printed circuit board laminate. The material is limited to 500 MHz operational frequency due to its increased magnetic and dielectric losses. In this thesis the purpose is to understand the loss mechanisms, characterize and understand the state-of-the-art magneto-dielectric materials at microwaves, and to produce a magneto-dielectric material in the lab to understand the material better. A new material was developed with magneto-dielectric properties. The material was based on a polymer base of polystyrene that serves as a dielectric material and doped with nickel nanoparticles that produce the magnetic properties. The contents of the nanoparticles in the mix is a design variable. Nickel-polystyrene samples with different nickel contents of 0%, 2.3% and 4.5%, were produced in the lab and measured in-house to understand the loss mechanism and RF performance.

In this master thesis, electrical characterization of thin film CuInxGa(1−x)Se2 solar cells produced by Midsummer AB were performed with the aim of determining the dominant recombination path of these cells. Current-Voltage (IV), Quantum Effinciency (QE), temperature dependent IV (IVT) and Drive-Level Capacitance Profiling (DLCP) was used with the objective to investigate the dominant recombination path as well as provide some insight of the solar cells in order to create a baseline model using the modelling software SCAPS (Solar cell CAPacitance Simulator). The IV produced mostly consistent results with slight variation, most likely due to non uniformity of equipment. The QE showed consistent results between all cells indicating a stable process for the sample preparation. Using IVT measurements were taken from a temperature of 115K −300K in order to obtain the activation energy for the dominant recombination path. By comparing it with the band gap energy from the QE measurement, it was found that the dominant recombination path is in either the space charge region or in the bulk of the CIGS and not at the hetero interface. DLCP measurement were made at both low temperature and at room temperature and revealed that the cells had a similar doping as other comparable cells at 7×1016cm−3 . The initial baseline model created in SCAPS show a good agreement with the measured IV and currently indicates a spike in the band alignment, supporting the results for the IVT measurement.

Outside of the city environment, there are many unstructured and rough environments that are challenging in vehicle navigation tasks. In these environments, vehicle vibrations caused by rough terrain can be harmful for humans. In addition, a human operator can not work around the clock. A promising solution is to use artificial intelligence to replace human operators. I test this by using the artificial intelligence technique know as reinforcement learning, with the algorithm Proximal Policy Optimization, to perform some basic locomotion tasks in a simulated environment with a simple terrain vehicle. The terrain vehicle consists of two chassis, each having two wheels attached, connected to each other with an articulation joint that can rotate to turn the vehicle. I show that a trained model can learn to operate the terrain vehicle and complete basic tasks, such as finding and following a path while avoiding obstacles. I tested robustness by evaluating performance on sloped terrains with a model trained to operate on flat ground. The results from the tests with different slopes show that, for most environments, the trained model could handle slopes up to around 7.5-10 degrees without much issue, even though it had no way of detecting the slope. This tells us that the models can perform their tasks quite well even when disturbances are introduced, as long as these disturbances doesn't require them to significantly change their behaviors.