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Proton MR relaxation times T1 and T2 were determined in vitro in 136 small specimens of astrocytomas grades I-IV, of oligodendrogliomas, metastases of adenocarcinomas, meningiomas and acoustic neuromas. In addition, 7 samples of peritumoural white matter were analysed. The analysed specimens were studied microscopically in their entirety regarding tumour type and occurrence of necrosis and non-tum
Plutonium and americium have been measured in surface waters of the Greenland and Barents Seas and in the northern North Sea from 1980 through 1984. Measurements in water and biota, Fucus, Mytilus and Patella, were carried out in North-English and Scottish waters in 1982 and Fucus samples were collected from the Irish coast in 1983. Fallout is found to dominate as a source of 239+240Pu north of la
The aim of this study was to compare the influence of flow in the velocity range 0 to 25 mm/s on modulus, phase, real and imaginary images obtained with a standard magnetic resonance scanner (Siemens Magnetom, 0.5 T), and to develop a simple method for determination of flow velocities in vivo from this information. Using a flow phantom, the flow dependent magnetic resonance imaging (MRI) signal ha
In order to establish the validity of in vitro determination of the proton magnetic resonance (MR) relaxation times T1 and T2 in brain tissue at increasing time delay after death or operative excision, 81 brain tissue samples from 23 pigs were analyzed repeatedly. These samples, representing cortex, caudate nucleus and white matter, were studied microscopically after MR measurements. The T1 values
As part of an extensive air chemistry programme, during summer 1980, on board the Swedish ice-breaker 'Ymer', levels of 222Rn (radon) and its long-lived daughters 210Pb and 210Po were measured. The radon was trapped on charcoal and the long-lived daugther products sampled on filters on a daily basis. In addition, short-lived progenies were followed continuously on the filters in order to achieve a
The proton magnetic resonance (MR) relaxation times T1 and T2 were determined in autopsy specimens from 13 different regions of normal human brains. One hundred and seventy-four tissue samples from 25 brains were examined in a pulsed MR analyzer of 0.25 T and were then also studied histologically. There were regional differences in T1 and T2 within the cerebral gray matter but not within the white
Clots of 1 ml venous blood formed in glass tubes after 10 min at room temperature were incubated at 37°C with the radiopharmaceutical to be studied. Methods for quality control of the radiopharmaceuticals were compared. Gel chromatography scanning was found to give reliable information. The incorporation into the clot was studied at different pH values and after various time intervals. The highest
No Abstract
One major problem in microwave-induced clinical hyperthermia treatment of superficial tumours is to obtain therapeutic temperatures at the tumour periphery and adequate deep heating when using a single applicator. The use of multiple applicators has therefore been investigated in order to improve the power distribution. Anatomical surface topography often permits the application of two tilted appl
Regional blood flow in rat liver and in inoculated liver tumors was studied before, during and after local hyperthermia treatment at 42.0°C for one hour. Hyperthermia was induced by microwave irradiation of the central liver lobe. The method used for blood flow studies was the clearance of Xenon-133 following portal and intraparenchymal injection. The wash-out curves were analyzed by using a bi-ex
The uptake of97Ru-transferrin (Ru-TF) in tumor and abscess bearing animals was compared with67Ga-citrate (Ga),123I-transferrin (I-TF), and several other plasma proteins. Maximal concentration in tumor of Ru-TF in mice was three times higher than67Ga-citrate (16.80±4.20 vs 5.08±0.58% D/g) although it occurred later (24 h compared with67Ga which reached its maximum 2 h after injection). Whole body a
The blood flow in rat liver was measured with Xe-133. Three techniques for administering the activity to the liver were employed: injection via the portal vein, via the hepatic artery, and directly into the liver parenchyma. Use of intraparenchymal injection of Xe-133 gave 60% higher flow values than by portal or arterial injection techniques. Mean flow index (k1) was for portal injection 0.52, fo
A computerized system for inducing total body hyperthermia by microwave irradiation was tested in rats. The tolerance to hyperthermia at different temperatures and fractions was studied as well as its effect on the growth of transplanted adenocarcinomas in the liver. Survival results indicated that 41.5 degrees C was maximum tolerated temperature both after single and repeated one hour exposures.
The biokinetics of inert lymphoscintigraphic agentsstrongly depends on their particle size. Different techniques for characterization of colloids are discussed. Experiments have been performed on eight different colloids. The particle size has been investigated with scanning electron microscopy. Activity distributions have been obtained with ultrafiltration and gel-column scanning technique. The c
The effect of general microwave hyperthermia and hepatic artery ligation (HAL) was tested on Wistar rats with a transplanted N‐methyl‐N‐nitroso‐guanidine‐induced adenocarcinoma in the liver. Total body hyperthermia (41.5°C for 1 hour, three times during 24 hours) was given on the same day as HAL, and 1, 2, and 3 days after. HAL induced a slower tumor growth than untreated controls. No additive eff
The present study aimed at comparing two renal function tests using 99mTc-DTPA (diethylene triamine penta acetic acid) and 131I-labeled hippuran (o-hippuric acid). A mixture of 80 Mbq 99mTc-DTPA and 7.4 MBq 131I-hippuran in a total volume of 1.5 ml or less was injected into an arm-vein. Both radiopharmaceuticals have identical intitial distributions in the blood pool when injected in this manner.
This work presents an analysis of the observed trends in extreme precipitation events in the Paraná River basin (PRB) from 1977 to 2016 (40 yr) based on daily records from 853 stations. The Mann–Kendall test and inverse-distance-weighted interpolation were applied to annual and seasonal precipitation and also for four extreme precipitation indices. The results show that the negative trends (signif
We describe the process behind a large international research project using a case study approach. We discuss how the basic idea behind the project was developed, as well as the planning and implementation of the field study, including a number of challenges that we faced during the data collection and data analysis phases. We discuss how using an initial conceptual model, the extensive qualitativ
