| 1. |
- Bernitt Cartemo, Petty, 1984, et al.
(författare)
-
Building a generic voxel phantom ofIRINA for Monte Carlo simulations
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The human phantom IRINA, which is widely used for whole body counting calibrations, has been modelled using MATLAB. This document summa-rizes and explains the procedure that was applied for building voxel ver-sions of IRINA in standing position. All 6 sizes in standing positions were successfully modelled with the help of MATLAB and the files are ready to use for any MC simulation. The MC code GATE was used to verify the geometry of the IRINA phantom by comparing the placement of source tubes and scatterers in the Monte Carlo model to the original IRINA docu-mentation. The methodology can easily be used for building voxel phan-toms of IRINA in sitting and bending position, as well as any other geome-try that may be needed.
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| 2. |
- Bernitt Cartemo, Petty, 1984, et al.
(författare)
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Comparison of computational phantoms and investigation of the effect of biodistribution on activity estimations
- 2016
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Ingår i: Radiation Protection Dosimetry. - : Oxford University Press (OUP). - 0144-8420 .- 1742-3406. ; 171:3, s. 358-364
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Tidskriftsartikel (refereegranskat)abstract
- We have made a comparison between two computational phantoms, modeled from the unified phantom UPh-08T, for whole-body counting applications. One of these was further compared with the ICRP reference adult male computational phantom. The simulations that were performed for the comparison of all three voxel phantoms use various distributions of 60Co. The two voxel phantoms of the UPh-08T showed good agreement, despite different methods of phantom modeling. Also, effects on efficiency of the inhomogeneous distribution of a radionuclide in the computational UPh-08T phantom were studied, using the realistic biodistribution of 140La. Our results show that the activity estimation of radionuclides, which are inhomogeneously distributed in the human body, will be in error if a homogeneous distribution is assumed for the calibration of whole-body counting systems.
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| 3. |
- Bernitt Cartemo, Petty, 1984, et al.
(författare)
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Depth Profiling with the Chalmers Pulsed Positron Beam
- 2014
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Ingår i: International Journal of Nuclear Energy Science and Technology. - 1741-637X .- 1741-6361. ; 8:2, s. 105 - 116
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Tidskriftsartikel (refereegranskat)abstract
- Positron lifetime measurements are used as a tool for obtaining a deeper understanding of positron behaviour in solids and calibrating the Chalmers Pulsed Positron Beam. Experiments are executed for positron energies up to 13 keV corresponding to the maximum penetration depth in Au of roughly 400 nm and measurement results are compared to PENELOPE simulations. Reference towards Makhov modelling is made. The future goal of the study is to investigate the depth dependence of ion-induced radiation damage where positrons will be used to characterise sizes and intensities of vacancy-type lattice defects.
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| 4. |
- Bernitt Cartemo, Petty, 1984, et al.
(författare)
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Sensitivity of the neutronic design of an Accelerator-Driven System (ADS) to the anisotropy of yield of the neutron generator and variation of nuclear data libraries
- 2013
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Ingår i: Proceeding of ESARDA meeting 2013.
-
Konferensbidrag (refereegranskat)abstract
- The Accelerator-Driven System concept was chosen to be a basis for the Multi-purpose Hybrid Research Reactor for High-tech Applications (MYRRHA), which can operate in both sub-critical and critical mode. Therefore, the design studies in the scope of this project were varying from accelerator and material aspects to the demonstration of transmutation possibilities of the system. However, the sensitivity of neutron characteristics of the system to the anisotropy of yield of neutron generator and variation of nuclear data libraries may appear to be an important issue.In this study the corresponding sensitivity analysis was performed in order to evaluate the sensitivity of ADS neutronic design to the variation of nuclear data libraries and influence of the anisotropy of the neutron yield of the accelerator.
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| 5. |
- Cartemo, Petty, et al.
(författare)
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Letter to the Editor.
- 2016
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Ingår i: Radiation protection dosimetry. - : Oxford University Press (OUP). - 1742-3406 .- 0144-8420. ; 168:2
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 6. |
- Chernikova, Dina, 1982, et al.
(författare)
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A direct method for evaluating the concentration of boric acid in a fuel pool using scintillation detectors for joint-multiplicity measurements
- 2013
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 714, s. 90-97
-
Tidskriftsartikel (refereegranskat)abstract
- The present investigations are aimed at the development of a direct passive non-intrusive method for determining the concentration of boric acid in a spent fuel pool using scintillation detectors with the purpose of correcting joint-multiplicity measurement results. The method utilizes a modified relation between two gamma lines with energy of 480 keV and 2.23 MeV, respectively. The gamma line at 480 keV belongs to the thermal neutron capture in boron. The 2.23 MeV gamma line characterizes the capture of thermal neutrons in hydrogen. Thus, the relation between them can reveal the concentration of the boron in the fuel pool. In order to test this method, first MCNPX and MCNP-PoliMi simulations were performed. Then, based on the results of Monte Carlo simulations, the method was verified by an experimental study with a 241Am-Be source and EJ-309 scintillation detectors. The concentration of boron in water varied from 1550 ppm to 4000 ppm. The results of these tests are provided in the paper and they show that the spectral ratio between these two lines can in principle be used to determine the boron content.
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| 7. |
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| 8. |
- Chernikova, Dina, 1982, et al.
(författare)
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A potential alternative/complement to the traditional thermal neutron based counting in Nuclear Safeguards and Security
- 2016
-
Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 810, s. 164-171
-
Tidskriftsartikel (refereegranskat)abstract
- A new concept for thermal neutron based correlation and multiplicity measurements is proposed in this paper. The main idea of the concept consists of using 2.223 MeV gammas (or 1.201 MeV, DE) originating in the (1) H (n,gamma)D-2-reaction instead of using traditional thermal neutron counting. Results of investigations presented in this paper indicate that gammas from thermal neutron capture reactions preserve the information about the correlation characteristics of thermal (fast) neutrons in the same time scale. Therefore, instead of thermal neutron detectors (or as a complement) one may use traditional and inexpensive gamma detectors, such as Nal, BGO, CdZnTe or any other gamma detector. In this work we used D8 x 8 cm(2) Nal scintillator to test the concept. Thus, the new approach helps to address the problem of replacement of He-3-counters and problems related to the specific measurements of spent nuclear fuel directly in the spent fuel pool. It has a particular importance for Nuclear Safeguards and Security. Overall, this work represents the proof of concept study and reports on the experimental and numerical evidence that thermal neutron capture gammas may be used in the context of correlation and multiplicity measurements. Investigations were performed using a (252)-Cf-correlated neutron source and an Am-241-Be-random neutron source. The related idea of the Gamma Differential Die-Away approach is investigated numerically in this paper as well, and will be tested experimentally in future work.
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| 9. |
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| 10. |
- Chernikova, Dina, 1982, et al.
(författare)
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Novel passive and active tungsten-based identifiers for maintaining the continuity of knowledge of spent nuclear fuel copper canisters
- 2015
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Ingår i: Annals of Nuclear Energy. - : Elsevier BV. - 0306-4549 .- 1873-2100. ; 75, s. 219-227
-
Tidskriftsartikel (refereegranskat)abstract
- A new approach to provide a long-term safeguards identification of spent nuclear fuel containers, in particular copper canisters, is presented in this paper. The approach proposes the use of a tungsten insert marked with a binary code and placed inside the container. The insert is read with a combination of two independent techniques, radiation and ultrasonic measurements, in order to get a unique identification of the cask. Passive and active versions of the tag are considered. The passive version makes use of the radiation coming from the spent nuclear fuel itself. The active version of the tag is based on the use of an artificially introduced mixture of α-emitting isotopes, such as 241Am with materials, 11B and 23Na, which easily undergo α-induced reactions with emission of specific γ-lines, 2313 keV and 1809 keV, respectively. The paper discusses results of the radiation and ultrasonic measurements and Monte-Carlo evaluations as the first proof of the concept. The results of the investigations show the strong potential for this concept to maintain the continuity of knowledge of spent nuclear fuel copper canisters for a time scale up to a few thousands years without compromising the environmental safety of the casks.
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| 11. |
- Chernikova, Dina, 1982, et al.
(författare)
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Testing a direct method for evaluating the concentration of boron in a fuel pool using scintillation detectors, and a 252Cf and an 241Am-Be source
- 2013
-
Ingår i: Proceeding of ESARDA meeting 2013.
-
Konferensbidrag (refereegranskat)abstract
- The present investigations are aimed at the development and testing of a direct non-destructive method for evaluating the concentration of boron in a fuel pool using scintillation detectors. The method uses a modified ratio between two gamma lines with energy of 480 keV and 2.23 MeV. These lines belong to the capture of a thermal neutron in boron and hydrogen, respectively. The relation between them can reveal the concentration of boron in the fuel pond.The method proposed was tested in a laboratory experiment with a 252Cf and an 241Am-Be source. EJ-309 liquid scintillation detectors were used for measurements of gamma spectra. The concentration of boron in water varied from 1550 ppm to 4200 ppm. The optimization and test studies were performed via MCNPX simulations.The results of these tests are provided in the present paper and they show that the boron content in water can be determined through using the characteristics of gamma lines with energy of 480 keV and 2.23 MeV.
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| 12. |
- Chernikova, Dina, 1982, et al.
(författare)
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Testing of small detectors with glass rod light guides for multiplicity measurement purposes
- 2012
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Ingår i: Proceedings of The 53nd Annual Meeting of the Institute of Nuclear Materials Management.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this paper we investigate the applicability of small scintillators with glass rod lightguides to measure both neutrons and gamma rays from the sample. Experimental test ofthese detectors and their suitability for the task can be performed at Lund University usingnatural uranium rods, therefore the MCNPX simulation set-up corresponds to the Lund con-figuration. The long-term goal of this research is to develop a method of joint-multiplicitycounting for fuel evaluation into a technology capable of quantifying plutonium in the fuelpool, where a lot of factors, such as presence of neutron absorbers (boron acid), can affect al-most all parameters, such as multiplication etc. Therefore, part of the present investigationswas devoted to the development of a direct method for determination of the concentrationof boron acid in the fuel pool using scintillation detectors with further correction of mea-surement results. For this purpose we suggest a method which utilizes a relation betweengamma lines with energy of 480 keV and 2.23 MeV for the direct evaluation of concentrationof boron acid in water. Test results of the new method, and an answer to questions regardingthe ability to measure both neutron and gamma rays using small scintillation detectors withglass rod light guides are provided in this paper.
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| 13. |
- Chernikova, Dina, 1982, et al.
(författare)
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The neutron-gamma Feynman variance to mean approach: Gamma detection and total neutron-gamma detection (theory and practice)
- 2015
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 782, s. 47-55
-
Tidskriftsartikel (refereegranskat)abstract
- Two versions of the neutron gamma variance to mean (Feynman-alpha method or Feynman-Y function) formula for either gamma detection only or total neutron gamma detection, respectively, are derived and compared in this paper. The new formulas have particular importance for detectors of either gamma photons or deleclors sensitive to both neutron and gamma radialion. If applied to a plastic or liquid deleclor, he total neutron-gamma detection Feynman-Y expression corresponds Lo a situation where no discrimination is made between neutrons and gamma parlicles. The gamma variance Lo mean formulas are useful when a detector of only gamma radialion is used or when working with a combined neutron-gamma deleclor at high count rates. The theoretical derivation is based on the Chapman-Kolmogorov equation with the inclusion of general reactions and corresponding intensities for neutrons and gammas, but with the inclusion of prompt reactions only. A one energy group approximation is considered. The comparison of the two different theories is made by using reaction intensities obtained in MCNPX simulations with a simplified geometry for two scintillation detectors and a Cf-252-source. In addition, the variance to mean ratios, neutron, gamma and total neutron-gamma are evaluated experimentally for a weak Cf-252 neutron-gamma source, a Cs-137 random gamma source and a Na-22 correlated gamma source. Due to the focus being on the possibility of using neutron-gamma variance to mean theories for both reactor and safeguards applications, we limited the present study to the general analytical expressions for Feynman-alpha formulas.
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| 14. |
- Eckerström, Marie, 1981, et al.
(författare)
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Longitudinal evaluation of criteria for subjective cognitive decline and preclinical Alzheimer's disease in a memory clinic sample.
- 2017
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Ingår i: Alzheimer's & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 16:8, s. 96-107
-
Tidskriftsartikel (refereegranskat)abstract
- Subjective cognitive decline (SCD) and biomarker-based "at-risk" concepts such as "preclinical" Alzheimer's disease (AD) have been developed to predict AD dementia before objective cognitive impairment is detectable. We longitudinally evaluated cognitive outcome when using these classifications.Memory clinic patients (n=235) were classified as SCD (n=122): subtle cognitive decline (n=36) and mild cognitive impairment (n=77) and subsequently subclassified into SCDplus and National Institute on Aging-Alzheimer's Association (NIA-AA) stages 0 to 3. Mean (standard deviation) follow-up time was 48 (35) months. Proportion declining cognitively and prognostic accuracy for cognitive decline was calculated for all classifications.Among SCDplus patients, 43% to 48% declined cognitively. Among NIA-AA stage 1 to 3 patients, 50% to 100% declined cognitively. The highest positive likelihood ratios (+LRs) for subsequent cognitive decline (+LR 6.3), dementia (+LR 3.4), and AD dementia (+LR 6.5) were found for NIA-AA stage2.In a memory clinic setting, NIA-AA stage 2 seems to be the most successful classification in predicting objective cognitive decline, dementia, and AD dementia.
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| 15. |
- Jenkins, D. G., et al.
(författare)
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Proof-of-principle for fast neutron detection with advanced tracking arrays of highly segmented germanium detectors
- 2009
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 602:2, s. 457-460
-
Tidskriftsartikel (refereegranskat)abstract
- Recent advances in germanium detector technology have promised much higher efficiency for gamma-ray detection through tracking the interaction of 7-rays in the crystal using pulse shape analysis. We present a related approach where the unique characteristics of the excitation and delayed decay of the excited 0(+) state in Ge-72 within a highly segmented germanium detector may be used as a very sensitive tag for fast neutrons by making use of pulse shape analysis. A proof-of-principle of this technique is presented and an efficiency for fast neutrons of up to 1.5% for a 4 pi tracking array is deduced, Neutron interactions may be localised with the unprecedentedly high angular resolution of 0.5 degrees for a compact (20-cm radius) array. The application of these properties as a novel approach to a broad class of important transfer reactions such as (d,n) and (He-3,n) is presented. (C) 2009 Elsevier B.V. All rights reserved.
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| 16. |
- Lehman, Eberhard, et al.
(författare)
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Neutron radiography with 14 MeV neutrons from a neutron generator
- 2005
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Ingår i: IEEE Transactions on Nuclear Science. ; 52:1, s. 389-393
-
Konferensbidrag (refereegranskat)abstract
- Neutrons with the initial energy of 14 MeV produced by the neutron generator of the Department of Reactor Physics, Chalmers Univ. of Techn., were detected by a camera system in connection with scintillator screens. Images were prodiced for 14 MeV and moderated neutrons with suited scintillator screens. Qualitative and quantitative evaluations were made to characterize the performance of the experimental setup.
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| 17. |
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| 18. |
- Mattsson, Håkan, 1969, et al.
(författare)
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Collimation and background in the pulsed neutron activation method for determination of water flow in pipes
- 2007
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Ingår i: International Journal of Nuclear Energy Science and Technology. - 1741-637X .- 1741-6361. ; 3:1, s. 12-
-
Tidskriftsartikel (refereegranskat)abstract
- In a Pulsed Neutron Activation (PNA) flowmeter, the water in a pipe is bombarded with neutron pulses, which introduce activity into the pipe. The activity is mixed with the flow, and gamma radiation emitted from the activity is measured with a detector downstream. The average velocity of the water is then calculated using the time-resolved detector signal. In this paper, the effect of collimation of the neutron radiation has been investigated. Such a collimation would increase the accuracy of the measurement, but the use of a collimator requires the distance between the pipe and the neutron source to be increased, with a corresponding loss in count rate. The results show that this loss makes neutron collimators in PNA of little use. In addition, a method to identify and subtract the background originating from stationary sources in a PNA measurement was developed.
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| 19. |
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| 20. |
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| 21. |
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| 22. |
- Mileshina, Larisa, 1970, et al.
(författare)
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Design and performance of the pulsed positron beam at Chalmers University of Technology
- 2009
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 267:17, s. 2934-2937
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Tidskriftsartikel (refereegranskat)abstract
- A slow monoenergetic pulsed positron beam at Chalmers University of Technology has been built. The system consists mainly of chopper, buncher and accelerator. The achieved positron energy range is in range between 230 eV and 15 keV. The FWHM of the beam resolution function is around 700 ps. The beam intensity is around 10(3) cps. (C) 2009 Elsevier B.V. All rights reserved.
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| 23. |
- Nordlund, Anders, 1964, et al.
(författare)
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Building a comprehensive nuclear education in Sweden
- 2013
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Ingår i: Conference on Nuclear Training and Education 2013, CONTE 2013: An International Forum for Discussion of Issues Facing Nuclear Energy Training and Education. - 9781627480130 ; , s. 40-
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Konferensbidrag (refereegranskat)
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| 24. |
- Owrang, Farshid, 1972, et al.
(författare)
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A method for in-situ quantification of oxygen in oil using fast neutron activation analysis
- 2004
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Ingår i: Kerntechnik. - 0932-3902. ; 69:1-2, s. 51-57
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Tidskriftsartikel (refereegranskat)abstract
- The feasibility of an experimental methodology for in-situ quantification of oxygen in bulk oil using fast neutron activation analysis (FNAA) has been studied. The method was applied for determination of oxygen in 100 ml (~90 g) rapeseed oil. The amount of oxygen in the rapeseed oil using the in-situ FNAA was estimated to 10.6 ± 2.6 weight %. Using cyclic fast neutron activation analysis (cFNAA), the amount of oxygen in the oil was determined in average 9.9 ± 0.4 weight %. Based on Monte Carlo calculations on water, the optimal radius and height of a cylindrical container where the activity is distributed through stirring of the water would be about 10 cm and 44 cm, respectively. These dimensions give a volume of about 14 liters, which is suitable for any type of oil. The accuracy in the in-situ FNAA can be increased by a more precise determination of oxygen in rapeseed oil in the beginning of a dynamic process using cFNAA or alternatively by a better background subtraction.
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| 25. |
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| 26. |
- Quinlan, Patrick, et al.
(författare)
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Low serum insulin-like growth factor-I (IGF-I) level is associated with increased risk of vascular dementia
- 2017
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Ingår i: Psychoneuroendocrinology. - : Elsevier BV. - 0306-4530. ; 86, s. 169-175
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Tidskriftsartikel (refereegranskat)abstract
- Background Insulin-like growth factor-I (IGF-I) is important for the adult brain, but little is known of the role of IGF-I in Alzheimeŕs disease (AD) or vascular dementia (VaD). Methods A prospective study of 342 patients with subjective or objective mild cognitive impairment recruited at a single memory clinic. We determined whether serum IGF-I concentrations at baseline were associated with the risk of all-cause dementia, AD, or VaD. Patients developing mixed forms of AD and VaD were defined as suffering from VaD. The statistical analyses included Cox proportional hazards regression analysis. Results During the follow-up (mean 3.6 years), 95 (28%) of the patients developed all-cause dementia [AD, n = 37 (11%) and VaD, n = 42 (12%)]. Low as well as high serum IGF-I (quartile 1 or 4 vs. quartiles 2–3) did not associate with all-cause dementia [crude hazard ratio (HR) 1.30, 95% confidence interval (CI): 0.81–2.08 and crude HR 1.05, 95% CI: 0.63–1.75, respectively] or AD (crude HR 0.79, 95% CI: 0.35–1.79 and crude HR 0.94, 95% CI: 0.43–2.06, respectively]. In contrast, low serum IGF-I concentrations were associated with increased risk of VaD (quartile 1 vs. quartiles 2–3, crude HR 2.22, 95% CI: 1.13–4.36). The latter association remained significant also after adjustment for multiple covariates. Conclusions In a memory clinic population, low serum IGF-I was a risk marker for subsequent VaD whereas low IGF-I did not associate with the risk of AD. High serum IGF-I was not related to the risk of conversion to dementia. © 2017 Elsevier Ltd
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| 27. |
- Retegan Vollmer, Teodora, 1979, et al.
(författare)
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Human capital needs - Teaching, training and coordination for nuclear fuel cycle
- 2013
-
Ingår i: International Nuclear Fuel Cycle Conference, GLOBAL 2013: Nuclear Energy at a Crossroads. ; 2, s. 1621-1624
-
Konferensbidrag (refereegranskat)abstract
- Human capital is the accumulation of competencies, knowledge, social and creativity skills and personality attributes, which are necessary to perform work so as to produce economic value. In the frame of the nuclear fuel cycle, this is of paramount importance that the right human capital exists and in Europe this is fostered by a series of integrated or directed projects. The teaching, training and coordination will be discussed in the frame of University curricula with examples from several programs, like e.g. the Master of Nuclear Engineering at Chalmers University, Sweden and two FP7 EURATOM Projects: CINCH and ASGARD. The integration of the university curricula in the market needs but also the anchoring in the research and future fuel cycles will be also discussed, with examples from the ASGARD project.
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| 28. |
- Skarnemark, Gunnar, 1948, et al.
(författare)
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A Unique Master´s Program in Combined Nuclear Technology and Nuclear Chemistry at Chalmers University of Technology
- 2009
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Ingår i: AIP Conference Proceedings. - 1551-7616 .- 0094-243X. ; :1164, s. 78-84
-
Tidskriftsartikel (refereegranskat)abstract
- The need for engineers and scientists who can ensure safe and secure use of nuclear energy is large in Sweden and internationally. Chalmers University of Technology is therefore launching a new 2-year master´s program in Nuclear Engineering, with start from the autumn of 2009. The program is open to Swedish and foreign students. The program starts with compulsory courses dealing with the basics of nuclear chemistry and physics, radiation protection, nuclear power and reactors, nuclear fuel supply, nuclear waste management and nuclear safety and security. There are also compulsory courses in nuclear industry applications and sustainable energy futures. The subsequent elective courses can be chosen freely but there is also a possibility to choose informal tracks that concentrate on nuclear chemistry or reactor technology and physics. The nuclear chemistry track comprises courses in e.g. chemistry of lanthanides, actinides and transactinides, solvent extraction, radioecology and radioanalytical chemistry and radiopharmaceuticals. The program is finished with a one semester thesis project. This is probably a unique master program in the sense of its combination of deep courses in both nuclear technology and nuclear chemistry.
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| 29. |
- Tengborn, Elisabeth, 1978, et al.
(författare)
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Effect of the misorientation of the 4H-SiC substrate on the open volume defects in GaN grown by metal-organic chemical vapor deposition
- 2006
-
Ingår i: Applied Physics Letters. ; 89:091905, s. 3-
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Tidskriftsartikel (refereegranskat)abstract
- Positron annihilation spectroscopy has been used to study GaN grown by metal-organic chemical vapor deposition on misoriented 4H-SiC substrates. Two kinds of vacancy defects are observed: Ga vacancies and larger vacancy clusters in all the studied layers. In addition to vacancies, positrons annihilate at shallow traps that are likely to be dislocations. The results show that the vacancy concentration increases and the shallow positron trap concentration decreases with the increasing substrate misorientation.
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| 30. |
- Vesterlund, Anna, 1980, et al.
(författare)
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Characterization of strong 241Am sources
- 2015
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Ingår i: Applied Radiation and Isotopes. - : Elsevier BV. - 0969-8043 .- 1872-9800. ; 99, s. 162-167
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Tidskriftsartikel (refereegranskat)abstract
- Gamma ray spectra of strong 241Am sources may reveal information about the source composition as there may be other radioactive nuclides such as progeny and radioactive impurities present. In this work the possibility to use gamma spectrometry to identify inherent signatures in 241Am sources in order to differentiate sources from each other, is investigated. The studied signatures are age, i.e. time passed since last chemical separation, and presence of impurities. The spectra of some sources show a number of Doppler broadened peaks in the spectrum which indicate the presence of nuclear reactions on light elements within the sources. The results show that the investigated sources can be differentiated between by age and/or presence of impurities. These spectral features would be useful information in a national nuclear forensics library (NNFL) in cases when the visual information on the source, e.g. the source number, is unavailable.
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| 31. |
- Vesterlund, Anna, 1980, et al.
(författare)
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Characterization of strong 241Am sources
- 2014
-
Ingår i: International Conference on Advances in Nuclear Forensics: Countering the Evolving Threat of Nuclear and Other Radioactive Material out of Regulatory Control, Vienna, IAEA; 07/2014.
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Konferensbidrag (refereegranskat)
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| 32. |
- Wallin, Anders, 1950, et al.
(författare)
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Alzheimer's disease-subcortical vascular disease spectrum in a hospital-based setting: overview of results from the Gothenburg MCI and dementia studies.
- 2016
-
Ingår i: Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism. - : SAGE Publications. - 1559-7016. ; 36:1, s. 95-113
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Forskningsöversikt (refereegranskat)abstract
- The ability to discriminate between Alzheimer's disease (AD), subcortical vascular disease, and other cognitive disorders is crucial for diagnostic purposes and clinical trial outcomes. Patients with primarily subcortical vascular disease are unlikely to benefit from treatments targeting the AD pathogenic mechanisms and vice versa. The Gothenburg mild cognitive impairment (MCI) and dementia studies are prospective, observational, single-center cohort studies suitable for both cross-sectional and longitudinal analysis that outline the cognitive profiles and biomarker characteristics of patients with AD, subcortical vascular disease, and other cognitive disorders. The studies, the first of which started in 1987, comprise inpatients with manifest dementia and patients seeking care for cognitive disorders at an outpatient memory clinic. This article gives an overview of the major published papers (neuropsychological, imaging/physiology, and neurochemical) of the studies including the ongoing Gothenburg MCI study. The main findings suggest that subcortical vascular disease with or without dementia exhibit a characteristic neuropsychological pattern of mental slowness and executive dysfunction and neurochemical deviations typical of white matter changes and disturbed blood-brain barrier function. Our findings may contribute to better healthcare for this underrecognized group of patients. The Gothenburg MCI study has also published papers on multimodal prediction of dementia, and cognitive reserve.Journal of Cerebral Blood Flow & Metabolism advance online publication, 29 July 2015; doi:10.1038/jcbfm.2015.148.
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| 33. |
- Wallin, Anders, 1950, et al.
(författare)
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Cognitive medicine - a new approach in health care science.
- 2018
-
Ingår i: BMC psychiatry. - : Springer Science and Business Media LLC. - 1471-244X. ; 18:1
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Tidskriftsartikel (refereegranskat)abstract
- The challenges of today's society call for more knowledge about how to maintain all aspects of cognitive health, such as speed/attention, memory/learning, visuospatial ability, language, executive capacity and social cognition during the life course.Medical advances have improved treatments of numerous diseases, but the cognitive implications have not been sufficiently addressed. Disability induced by cognitive dysfunction is also a major issue in groups of patients not suffering from Alzheimer's disease or related disorders. Recent studies indicate that several negative lifestyle factors can contribute to the development of cognitive impairment, but intervention and prevention strategies have not been implemented. Disability due to cognitive failure among the workforce has become a major challenge. Globally, the changing aging pyramid results in increased prevalence of cognitive disorders, and the diversity of cultures influences the expression, manifestation and consequences of cognitive dysfunction.Major tasks in the field of cognitive medicine are basic neuroscience research to uncover diverse disease mechanisms, determinations of the prevalence of cognitive dysfunction, health-economical evaluations, and intervention studies. Raising awareness for cognitive medicine as a clinical topic would also highlight the importance of specialized health care units for an integrative approach to the treatment of cognitive dysfunctions.
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| 34. |
- Wallin, Anders, 1950, et al.
(författare)
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The Gothenburg MCI study: design and distribution of Alzheimer's disease and subcortical vascular disease diagnoses from baseline to 6-year follow-up.
- 2016
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Ingår i: Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism. - : SAGE Publications. - 1559-7016. ; 36:1, s. 114-131
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Tidskriftsartikel (refereegranskat)abstract
- There is a need for increased nosological knowledge to enable rational trials in Alzheimer's disease (AD) and related disorders. The ongoing Gothenburg mild cognitive impairment (MCI) study is an attempt to conduct longitudinal in-depth phenotyping of patients with different forms and degrees of cognitive impairment using neuropsychological, neuroimaging, and neurochemical tools. Particular attention is paid to the interplay between AD and subcortical vascular disease, the latter representing a disease entity that may cause or contribute to cognitive impairment with an effect size that may be comparable to AD. Of 664 patients enrolled between 1999 and 2013, 195 were diagnosed with subjective cognitive impairment (SCI), 274 with mild cognitive impairment (MCI), and 195 with dementia, at baseline. Of the 195 (29%) patients with dementia at baseline, 81 (42%) had AD, 27 (14%) SVD, 41 (21%) mixed type dementia (=AD+SVD=MixD), and 46 (23%) other etiologies. After 6 years, 292 SCI/MCI patients were eligible for follow-up. Of these 292, 69 (24%) had converted to dementia (29 (42%) AD, 16 (23%) SVD, 15 (22%) MixD, 9 (13%) other etiologies). The study has shown that it is possible to identify not only AD but also incipient and manifest MixD/SVD in a memory clinic setting. These conditions should be taken into account in clinical trials.Journal of Cerebral Blood Flow & Metabolism advance online publication, 15 July 2015; doi:10.1038/jcbfm.2015.147.
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