| 1. |
- Choularton, T. W., et al.
(författare)
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The Great Dun Fell Cloud Experiment 1993 : An overview
- 1997
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Ingår i: Atmospheric Environment. - 1352-2310. ; 31:16, s. 2393-2405
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Tidskriftsartikel (refereegranskat)abstract
- The 1993 Ground-based Cloud Experiment on Great Dun Fell used a wide range of measurements of trace gases, aerosol particles and cloud droplets at five sites to study their sources and sinks especially those in cloud. These measurements have been interpreted using a variety of models. The conclusions add to our knowledge of air pollution, acidification of the atmosphere and the ground, eutrophication and climate change. The experiment is designed to use the hill cap cloud as a flow-through reactor, and was conducted in varying levels of pollution typical of much of the rural temperate continental northern hemisphere in spring-time.
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| 2. |
- Calén, H., et al.
(författare)
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Detector setup for a storage ring with an internal target
- 1996
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 379:1, s. 57-75
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Tidskriftsartikel (refereegranskat)abstract
- A detector setup for the cooler storage ring CELSIUS is described. The setup detects particles produced in interactions between the internal beam and a cluster-jet target. Particles emitted in the forward direction are measured by means of arrays of plastic scintillators and proportional counters. Particles, particularly photons, emitted more isotropically are measured by means of two calorimeters containing CsI(Na) crystals. The performance of the setup is given for neutral meson production in proton-proton and proton-deuteron interactions in the energy range 290-1360 MeV.
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| 3. |
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| 4. |
- Bergqvist, David, et al.
(författare)
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Secondary aortoenteric fistula : changes from 1973 to 1993
- 1996
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Ingår i: European Journal of Vascular and Endovascular Surgery. - 1078-5884 .- 1532-2165. ; 11:4, s. 425-428
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To investigate a series of patients with secondary aortoenteric fistulas and compare it with a previous series (1985-93 vs. 1973-84). DESIGN: Retrospective study of medical records. SETTING: Sixteen vascular surgical centers in Sweden. PATIENTS: Twenty-seven patients were identified making an overall incidence of 0.5% of all aortoiliac operations. Among aneurysm patients the incidence was significantly lower than in the previous series. One patient record could not be identified. Fourteen primary operations were for aortic aneurysm, 12 for occlusive disease and one was an aortorenal vein bypass. RESULTS: Symptoms of the fistula occurred after a median interval of 90 months which is significantly later than the previous series (32 months; p<0.05). The commonest presentation was bleeding followed by septis. The median diagnostic delay was 10.5 days, which was significantly shorter than in the previous series. Most fistulas involved the duodenum (88%). One patient died before surgery. The postoperative mortality was 28%, significantly lower than in the previous series (58%) (p<0.05). At the end of follow up (median 43 months) significantly more patients were alive than in the previous series (42% vs 18%) (p<0.05). CONCLUSION: Over a 21 year period there seems to have been a decrease in the frequency of secondary aortoenteric fistulas after aneurysm surgery, a longer interval before they occur, a shorter diagnostic delay, and a better survival.
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| 5. |
- Aitken, Candice L., et al.
(författare)
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Comparison of three methods used for fusion of SPECT-CT images of liver matastases
- 1998
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Ingår i: Fusion98, International Conference on Multisource-Mulltisensor Information Fusion. - : CSREA Press. - 1892512009 ; , s. 435-442
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Konferensbidrag (refereegranskat)abstract
- We compare three methods for fusing SPECT-CT images: ImageMatch - an automatic three-dimensional/two-dimensional method developed by Focus Imaging; IBM Visualization Data Explorer - a three-diemensional interactive method developed by Internation Business Machines, Inc.; and qsh - an interactive three-dimensional/two-dimensional method developed at New York University. While many fusion methods have proved successful for registering brain images, most methods have been less successful for thoracic and abdominal images. We use images of liver metastases obtained with a radiolabeled breast tumor-directed antibody to illustrate the strengths and weakness of the methods reviewed. The images used are typical clinical images from eigth patients. We conclude that an optimal image fusion program should combine the strengths of each of the methods reviewed.
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| 6. |
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| 7. |
- Farrell, Edward J., et al.
(författare)
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Graphical 3D medical image registration and quantification
- 1997
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Ingår i: Journal of medical systems. - 0148-5598 .- 1573-689X. ; 21:3, s. 155-172
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Tidskriftsartikel (refereegranskat)abstract
- We present a graphical three-dimensional method that facilitates image registration and fusion, and provides quantitative geometric and volume information. In particular it enhances the use of functional (radiopharmaceutical) imaging {(SPECT}, {PET)} which, though a powerful clinical tool, has the disadvantage of low spatial resolution and ill-defined boundaries. Registration between functional images and structural images {(MRI}, {CT)} can augment the anatomical context of these functional images.
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| 8. |
- Galvin, J. M., et al.
(författare)
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Warping CT scans from nontreatment to treatment position
- 1997
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Ingår i: Radiation oncology investigations (Print). - 1065-7541 .- 1520-6823. ; 5:4, s. 206-212
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes a cost-effective technique that optimally utilizes all available diagnostic studies for three-dimensional treatment planning. A simulator unit modified to produce cross-sectional images {(simulator-CT} unit) is used to create a reference data set with the patient in the treatment position. Registration software (qsh) brings other diagnostic studies into agreement with this reference data set. Two cases are presented as examples of the use of this technique. Registration of abdominal scans from the same patient demonstrates the warping of a nontreatment position study to the treatment position. The second case is based on paired data sets through the head, in which the diagnostic study was obtained by using a gantry tilt to follow the base of the skull and to avoid sections passing through the teeth. The registration software provides a method for combining diagnostic studies into a single "master" data set. The success of the transformation depends on the operator's ability to identify corresponding anatomic landmarks for different data sets and on the magnitude of the variation in the patient's position from one procedure to the next. Limitations in image quality and the number of cross-sections obtainable from a {simulator-CT} unit can be partially overcome by using the described technique. Thus, the information contained in nontreatment position diagnostic tests can be used accurately for treatment planning at limited cost.
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| 9. |
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| 10. |
- Wenning, Gregor K, et al.
(författare)
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Short- and long-term survival and function of unilateral intrastriatal dopaminergic grafts in Parkinson's disease
- 1997
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Ingår i: Annals of Neurology. - : Wiley. - 1531-8249 .- 0364-5134. ; 42:1, s. 95-107
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Tidskriftsartikel (refereegranskat)abstract
- Six patients with Parkinson's disease were followed for 10 to 72 months after human embryonic mesencephalic tissue from four to seven donors was grafted unilaterally into the putamen (4 patients) or putamen plus caudate (2 patients). After 8 to 12 months, positron emission tomography showed a 68% increase of 6-L-[18F]-fluorodopa uptake in the grafted putamen, no change in the grafted caudate, and minor decreases in nongrafted striatal regions. There was therapeutically valuable improvement in 4 patients, but only modest changes in the other 2, both of whom developed atypical features. Patient 4 was without L-dopa from 32 months and had normal fluorodopa uptake in the grafted putamen at 72 months. Overall, the L-dopa dose was reduced by a mean of 10 and 20%, "off" time was reduced by 34 and 44%, and the "off" phase Unified Parkinson's Disease Rating Scale motor score by 18 and 26%, and the duration of the response to a single L-dopa dose increased by 45 and 58% during the first and second years after surgery, respectively. Rigidity and hypokinesia improved bilaterally, but mainly contralateral to the implant. No consistent changes in dyskinesias were observed. We conclude that transplantation of embryonic mesencephalic tissue leads to highly reproducible survival of dopaminergic neurons, inducing clinically valuable improvements in most recipients.
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| 11. |
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