Roger Svensson

Learn More
A method for dose delivery monitoring after high energy photon therapy has been investigated based on positron emission tomography (PET). The technique is based on the activation of body tissues by high energy bremsstrahlung beams, preferably with energies well above 20 MeV, resulting primarily in 11C and 15O but also 13N, all positron-emitting(More)
Modern conformal radiotherapy benefits from heterogeneous dose delivery using scanned narrow bremsstrahlung beams of high energy in combination with dynamic double focused multi-leaf collimation and purging magnets. When using a purging magnet to remove electrons and positrons the target space is limited and unorthodox thin multi-layered targets are needed.(More)
BACKGROUND In ST-elevation myocardial infarction (STEMI), distal embolization of thrombus material often precludes restoration of normal coronary artery flow. Small-scaled studies have demonstrated that intracoronary thrombus aspiration improves flow and myocardial perfusion, but only one larger randomized single-center study has suggested a survival(More)
Rats were trained in a spatial T-maze discrimination either in a drugged (D=pentobarbital, 17.5 mg/kg) or in a non-drugged (N=saline) state (drug discrimination learning). Either of two external discriminative stimulus sets (light vs complete darkness) was consistently associated with the D or N state. When tested in the presence of the external stimulus(More)
The majority of patients from 4 orthodontic clinics in the south west of Sweden who have had bonded retainers on upper or lower anterior teeth for a period of at least 5 years were examined. The total failure rate during 5 years of observation was 36 per cent, slightly higher in the maxilla than in the mandible. The retainer had become detached in 15 per(More)
UNLABELLED The aim of this retrospective study was to assess the frequency of postoperative bleeding in patients on warfarin after tooth removal followed by a complete soft tissue closure of the surgical site. A total of 124 consecutive patients, 69 males and 55 females with a mean age of 71 years (range 28-95 years) were included in this study. Inclusion(More)
A new dosimeter, based on chemical vapour deposited (CVD) diamond as the active detector material, is being developed for dosimetry in radiotherapeutic beams. CVD-diamond is a very interesting material, since its atomic composition is close to that of human tissue and in principle it can be designed to introduce negligible perturbations to the radiation(More)
New solid-state detectors, based on chemical vapour deposited (CVD) polycrystalline diamonds produced by hot-filament (HF) or microwave plasma (MW) assisted deposition methods, were constructed for radiation therapy dosimetry. Properties of diamond crystals, such as high radiation sensitivity, resistance to radiation damage and tissue-equivalence giving a(More)
Mowing of semi-natural grasslands is an important management method to maintain the conservation value and species-richness of this habitat. Mowing using cutting instruments, e.g. sickle bar mowers, is thought to be superior by practitioners compared with other mechanical instruments that tears off the plant material, e.g. grass trimmers. However, almost no(More)
According to Schumpeter, the creative process of economic development can be divided into the three distinguishable stages of invention, innovation (commercialization) and imitation. Following this theory, invention and innovation require different skills. This paper tests whether the invention and innovation stages should be undertaken by different agents.(More)