| 1. |
- Johansson, Karl-Axel, et al.
(author)
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The quality assurance process for the ARTSCAN head and neck study - a practical interactive approach for QA in 3DCRT and IMRT.
- 2008
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In: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 87:2, s. 290-9
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Journal article (peer-reviewed)abstract
- AIM: This paper describes the quality assurance (QA) work performed in the Swedish multicenter ARTSCAN (Accelerated RadioTherapy of Squamous cell CArcinomas in the head and Neck) trial to guarantee high quality in a multicenter study which involved modern radiotherapy such as 3DCRT or IMRT. MATERIALS AND METHODS: The study was closed in June 2006 with 750 randomised patients. Radiation therapy-related data for every patient were sent by each participating centre to the QA office where all trial data were reviewed, analysed and stored. In case of any deviation from the protocol, an interactive process was started between the QA office and the local responsible clinician and/or physicist to increase the compliance to the protocol for future randomised patients. Meetings and workshops were held on a regular basis for discussions on various trial-related issues and for the QA office to report on updated results. RESULTS AND DISCUSSION: This review covers the 734 patients out of a total of 750 who had entered the study. Deviations early in the study were corrected so that the overall compliance to the protocol was very high. There were only negligible variations in doses and dose distributions to target volumes for each specific site and stage. The quality of the treatments was high. Furthermore, an extensive database of treatment parameters was accumulated for future dose-volume vs. endpoint evaluations. CONCLUSIONS: This comprehensive QA programme increased the probability to draw firm conclusions from our study and may serve as a concept for QA work in future radiotherapy trials where comparatively small effects are searched for in a heterogeneous tumour population.
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| 2. |
- Persson, Per-Axel, et al.
(author)
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High-pressure polymerized C60
- 1996
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In: Extended Abstracts of Carbon´96, European Carbon Conference, Newcastle-upon-Tyne 1996, volume 2. - : The British Carbon Group. ; , s. 746-747, s. 746-747
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Conference paper (other academic/artistic)
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| 3. |
- Persson, Per-Axel, et al.
(author)
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The physical properties of high-pressure polymerized C60
- 1997
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In: Journal of Physics and Chemistry of Solids, volume 58, issue 11. - : Elsevier B.V.. ; 58:11, s. 1881-1885
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Conference paper (peer-reviewed)abstract
- We have studied the structural, thermophysical, and spectroscopic properties of polymeric C60 obtained by high pressure treatment at pressures and temperatures near 1 GPa and 600 K. We present here a brief overview of our results for the structural and thermophysical properties and a more detailed report on recent results obtained by Raman spectroscopy on both thin films, polycrystalline, and single crystal material. The results presented include a comparison between Raman results for photopolymerized and pressure polymerized thin films and a preliminary estimate of the binding energy of polymeric C60.
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| 4. |
- Sundqvist, Bertil, et al.
(author)
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Physical properties of pressure polymerized C60
- 1996
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In: Fullerenes: Recent Advances in the Chemistry and Physics of Fullerenes and Related Materials, volume 3. - Pennington, NJ : The Electrochemical Society. - 1566771625 ; , s. 1014-1028
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Conference paper (peer-reviewed)abstract
- We present in this paper an overview of the physical properties of the high pressure polymerized C60 phase commonly known as "soft fcc". This phase has been studied by several methods over wide ranges in temperature T and/or pressure, p. We present here experimental information about the specific heat capacity, the thermal expansion coefficient, the lattice structure, and the thermal conductivity, and we also show results obtained by NMR and Raman spectroscopy. All data presented agree with the accepted model that the individual molecules in this phase are covalently bound to form linear molecular chains. In particular, the NMR data show clearly the presence of covalent bonds, and the Raman data exhibit several new lines at very low energies connected with chain vibrations. Thermal conductivity data obtained during polymerization show both the time dependence of the process and that polymerization occurs at lower p and T than observed previously for this phase.
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| 5. |
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| 6. |
- Böhlenius, Henrik, et al.
(author)
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Biomass production and fuel characteristics from long rotation poplar plantations
- 2023
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In: Biomass and Bioenergy. - : Elsevier Ltd. - 0961-9534 .- 1873-2909. ; 178
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Journal article (peer-reviewed)abstract
- One of the key elements in this transition is the securing of a large supply of sustainable biomass. In this study, the feedstock potential of long rotation poplar plantations (12–30 years with diameter of 15 of 30 cm) was determined and the properties of poplar biomass fuel were analyzed with the aim of using thermochemical conversion methods to produce biofuel. Our results demonstrate that Sweden has great potential for producing biofuels from long rotation poplar plantations, with a total of 1.8 million hectares (ha) consisting of arable (0.5 million ha) and forested arable land (1.3 million ha). Based on available land and biomass production potential, our results indicate that 10 million Mg DW could be produced annually. Regions in mid/southern Sweden have the largest potential (larger areas and higher biomass production. Our results further suggest that poplar biomass from these plantations has fuel characteristics similar to forest fuels from other conifer tree species, making the biomass suitable as feedstock for biofuel production based on thermochemical conversion methods. If 25% of the available land were used, 7.6 TWh methanol biofuels could be produced annually from 16 biofuel plants, using 160,000 Mg DW yr−1, primarily located in the southern part of Sweden. Two counties (Skåne and Västra Götaland) would be able to support their biofuel plants using poplar plantations as feedstock. Stable biofuel production in the other counties would depend on collaborating with neighboring counties.
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| 7. |
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| 8. |
- Palm, Fredrik, et al.
(author)
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Renomedullary Blood Flow And Blood Volume Are Increased During Vasopressin Escape
- 2010
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Conference paper (peer-reviewed)abstract
- Hyponatremia is a common electrolyte disorder usually caused by inappropriate vasopressin (AVP) levels relative to serum osmolality. The degree of the hyponatremia is limited by "escape" from AVP-induced antidiuresis, characterized by increased urine volume and decreased urine osmolality independently of circulating AVP. The mechanisms mediating escape are not fully understood, but we have hypothesized that increased renomedullary blood flow (BF) contributes to this process. We therefore investigated intrarenal BF and blood volume distribution in rats with and without escape.Adult male Sprague-Dawley rats (n=10) were infused with DDAVP (5 ng/h) to produce maximal antidiuresis. Half were fed a liquid diet (AIN-76) to produce escape; half were fed a solid diet to prevent escape. After 5 days, all rats were anesthetized with Inactin and high resolution images (voxel size 97x97x600 µm) of renal BF were acquired using a Siemens Definition Dual Source CT. Iopromide (0.15 ml/rat) was rapidly injected iv and the contrast over the kidney area was collected during 30 s. Data were evaluated by analyzing local renal contrast density utilizing the Siemens Syngo body perfusion tool and correlated to the aorta. Cortical and medullary BF were 709±41 and 251±50 ml/100ml/min respectively in non-escaped rats. Cortical BF in escaped rats was similar (588±81 ml/100ml/min), but medullary BF was increased compared to non-escaped rats (666±105 ml/100ml/min). Blood volumes were similar in the two groups in cortex (42±1 vs. 49±6 ml/100ml), but elevated in the medulla of escaped rats (70±3 vs 18±3 ml/100ml).Our results demonstrate that escape is accompanied by markedly elevated renomedullary BF and volume. Elevated BF to the renal medulla results in reduced interstitial osmolality, and may also contribute to the down-regulation of aquarporin-2 water channels known to accompany escape. These results therefore provide a potential mechanistic explanation for the reduced ability to concentrate urine during AVP escape.
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| 9. |
- Steinvall, Ove, et al.
(author)
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Laser dazzling impacts on car driver performance
- 2013
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Conference paper (peer-reviewed)abstract
- A growing problem for the Police and Security Forces has been to prevent potentially hostile individuals to pass a checkpoint, without using lethatl violence. Therefore the question has been if there is a laser or any other strong light source that could be used as a warning and dazzling device, without lethal or long term effects. To investigate the possibilities a field trial has been performed at a motor-racing track. A green CW laser with an irradiance on the eye of maximum 0.5 MPE, as defined by ICNIRP [1] and the ANZI standard [2], was used as a dazzle source. Ten drivers have been driving with dipped headlights through a course of three lines with orange cones. In every line there has been only one gate wide enough to pass without hitting the cones. The time through the course, the choice of gates and the number of cones hit have been measured. For every second trial drive through the track, the driver was exposed to the laser dazzler. The background illuminances ranged from a thousand lux in daylight to about ten millilux in darkness. The protective effect of the sun-visor of the car was investigated. The drives visual system was carefully examined before and after experimental driving and a few weeks after the experimental driving to verify that no pathological effects, that could potentially be induced by the laser exposure, pre-existed or occurred after the laser exposure. An analysis of variance for a within subjects design has been used for evaluation. It was found that green laser light can have an obvious warning effect in daylight. Dazzling does reduce the drivers ability to make judgments and manouver the car in twilight and darkness. A sun-visor can reduce the glare and give the driver an improved control, but that perception can be unjustified. No damage to the visual system was observed.
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| 10. |
- Sundqvist, Bertil, et al.
(author)
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Fullerenes under pressure : Structure, order, and disorder
- 1996
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In: High Pressure Science and Technology. - Singapore : World Scientific. - 9810225474 ; , s. 697-701
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Conference paper (peer-reviewed)abstract
- The weak intermolecular interactions in solid C60 and other fullerenes make crystal structures and other properties very sensitive to applied pressure. We review recent results on the properties and phases of fullerenes under pressure, concentrating on the low-p range up to about 1 GPa. Subjects discussed include compression and transport studies, orientational and rotational disorder, the glassy crystal transition, and pressure-induced polymerization.
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| 11. |
- Sundqvist, Bertil, et al.
(author)
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Orientational disorder and the p-T phase diagram of fullerenes
- 1995
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In: Fullerenes: Recent Advances in the Chemistry and Physics of Fullerenes and Related Materials, volume 2. - Pennington, NJ : The Electrochemical Society. - 1566771048 ; , s. 891-905
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Conference paper (peer-reviewed)abstract
- The translational and orientational structures of fullerenes are very sensitive to pressure, p, because of the weak intermolecular potentials. We have recently carried out high-p studies of the thermal conductivity lambda and the bulk modulus B of C60 and C70, and we show here how the p-T phase diagrams of these materials can be mapped from data for B and lambda and a knowledge of the structures at zero pressure. We discuss how B and lambda are modified by translational, rotational and orientational disorder in the materials, mainly showing examples related to the orientational substructure and its evolution with T and p in C60. We also discuss briefly the structures and phase diagrams of C70 and C61H2, and we show preliminary experimental results suggesting that the structure of high-p, high-T treated C60 is probably not polymeric as recently suggested by several groups.
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| 12. |
- Yu, Zhaohua, 1983-, et al.
(author)
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Green light laser exposure at 532nm near the exposure limit during a human volunteer vehicle driving task does not alter structure or function in the visual system
- 2014
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In: Journal of laser applications. - Melville : Laser Institute of America. - 1042-346X .- 1938-1387. ; 26:2, s. 022009-1-022009-7
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Journal article (peer-reviewed)abstract
- This study aimed to verify nonexistence of clinically important pathological effects to the visual system after exposure to 532 nm green laser light close to the exposure limit. The present medical surveillance of vision and visual health reported in this paper is the conjunction with a study of driver performance in the presence of 532 nm laser induced glare. The driving time varied between 25 and 55 s, depending on background luminance. The laser was on during the complete test drive. The peak corneal irradiance typically was 3.5Wm2 in one test drive. Considering a typical test drive, the typical time integrated corneal radiant exposure for one test drive was estimated to be 53 J/m2. The number of test drives varied among drivers but was typically 50, thus resulting in a cumulative corneal exposure dose of approximately 2.7 kJ/m2. Altogether, ten subjects were recruited according to inclusion and exclusion criteria. All ten subjects were examined for visual acuity, intraocular pressure, contrast sensitivity, color vision, monocular reading speed, and eye structure with clinical slit-lamp microscopy examination and indirect retinoscopy. All subjects were examined before exposure, immediately after exposure, and finally within an interval between 1 week and 4 weeks after exposure. There was no significant change of visual acuity, intraocular pressure, contrast sensitivity, color vision, or monocular reading speed between before and after exposure. No abnormal ocular structure was detected after exposure. This study demonstrates that close to exposure limit, exposure to 532 nm green laser light during a vehicle driving task does not induce structural or functional damage to the human visual system as observed in the interval minutes to weeks after exposure.
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| 13. |
- Zackrisson, Björn, et al.
(author)
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Two-year results from a Swedish study on conventional versus accelerated radiotherapy in head and neck squamous cell carcinoma - The ARTSCAN study
- 2011
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In: Radiotherapy and Oncology. - : Elsevier. - 0167-8140 .- 1879-0887. ; 100:1, s. 41-48
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Journal article (peer-reviewed)abstract
- Background and purpose: Studies on accelerated fractionation (AF) in head and neck cancer have shown increased local control and survival compared with conventional fractionation (CF), while others have been non-conclusive. In 1998 a national Swedish group decided to perform a randomised controlled clinical study of AF. Materials and methods: Patients with verified squamous cell carcinoma of the oral cavity, oropharynx, larynx (except glottic T1-T2, N0) and hypopharynx were included. Patients with prior chemotherapy or surgery were excluded. Patients were randomised to either CF (2Gy/day, 5days/week for 7 weeks, total dose 68Gy) or to AF (1.1Gy+2.0Gy/day, 5days/week for 4.5weeks, total dose 68Gy). An extensive quality assurance protocol was followed throughout the study. The primary end point was loco-regional tumour control (LRC) at two years after treatment. RESULTS: The study was closed in 2006 when 750 patients had been randomised. Eighty-three percent of the patients had stages III-IV disease. Forty eight percent had oropharyngeal, 21% laryngeal, 17% hypopharyngeal and 14% oral cancers. There were no significant differences regarding overall survival (OS) or LRC between the two regimens. The OS at two years was 68% for AF and 67% for CF. The corresponding figures for LRC were 71% and 67%, respectively. There was a trend towards improved LRC for oral cancers treated (p=0.07) and for large tumours (T3-T4) (p=0.07) treated with AF. The AF group had significantly worse acute reactions, while there was no significant increase in late effects. Conclusion: Overall the AF regimen did not prove to be more efficacious than CF. However, the trend towards improved results in AF for oral cancers needs to be further investigated.
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