| 1. |
- Claeson, Magdalena, 1976, et al.
(författare)
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Modelling the Future: System Dynamics in the Cutaneous Malignant Melanoma Care Pathway
- 2016
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Ingår i: Acta dermato-venereologica. - : Medical Journals Sweden AB. - 1651-2057 .- 0001-5555. ; 96:2, s. 181-185
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Tidskriftsartikel (refereegranskat)abstract
- Incidence rates for cutaneous malignant melanoma are increasing worldwide. Estimates of the future number of melanoma cases are important for strategic planning of the care pathway. The aim of this study was to use system dynamics modelling to evaluate the long-term effects of changes in incidence, population growth and preventive interventions. Historical data on invasive melanoma cases in Western Sweden from 1990 to 2006 were obtained. Using computer simulation software, a model estimating the accumulated number of melanoma cases for 2014 to 2023 was developed. Five future scenarios were designed: stable incidence, business-as-usual, 25% reduced patient's delay, 50% reduced doctor's delay, and a combination of the last 2, called improved overall secondary prevention. After 10 years, improved overall secondary prevention would have resulted in a 42% decrease in melanomas >4 mm and a 10% increase in melanomas ≤1 mm, compared with business-as-usual. System dynamics is a valuable tool, which can help policymakers choose the preventive interventions with the greatest impact.
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| 2. |
- Claeson, Magdalena, 1976, et al.
(författare)
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Multiple primary melanomas in Western Sweden; 1990-2013
- 2016
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Ingår i: 3rd International Conference on UV and Skin Cancer Prevention, Melbourne.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- IntroductionIn Sweden, the incidence of cutaneous malignant melanoma rises yearly with 5.5% for men and 5.2% for women and has now reached world standard rates of 17.6 for men and 18.8 for women per 100,000 population. Over the past decades, the incidence of melanoma has been higher in Western Sweden than the national average. Previous international studies have shown that melanoma patients have an elevated risk of developing a new separate primary melanoma. This study aimed at describing multiple primary melanomas (MPMs) in Western Sweden with focus on the number of tumours detected, tumour characteristics and the time to diagnosis of a subsequent melanoma.MethodsData was extracted retrospectively from the Swedish Melanoma Registry and provided information on all invasive and in situ melanoma cases in Western Sweden (1.6 million inhabitants) from 1990 to 2013. Results Within the studied period, 12,152 patients developed 13,291 melanomas. 11,254 of the patients developed only a single primary melanoma. In total, 898 patients (7.4% of all melanoma patients) developed 2,037 MPMs. Preliminary results show that the median Breslow thickness for all invasive melanomas was below 1 mm. The median Breslow thickness for the MPMs was slightly thinner for the second and third invasive melanoma as compared to the first invasive melanoma. Further, there was a higher percentage of in situ tumours among the subsequent melanomas. The median time to diagnosis of a subsequent melanoma was approximately 3 years. DiscussionSubsequent primary melanomas in Western Sweden are most commonly diagnosed with a somewhat thinner Breslow thickness than the first primary melanoma. The comparatively high percentage of melanoma survivors developing MPMs and the short median time to diagnosis of a subsequent melanoma stresses the importance of follow-up for melanoma patients, particularly during the first years.
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| 3. |
- Claeson, Magdalena, 1976, et al.
(författare)
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MultiplePrimary Melanomas: A Common Occurrencein Western Sweden.
- 2017
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Ingår i: Acta dermato-venereologica. - : Medical Journals Sweden AB. - 1651-2057 .- 0001-5555. ; 97:6, s. 715-719
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Tidskriftsartikel (refereegranskat)abstract
- Patients diagnosed with a single primary cutaneous melanoma are at increased risk of developing multiple primary melanomas. The aim of this study is to describe the epidemiology of multiple primary melanomas (invasive and in situ) in Western Sweden. Data from the Swedish Melanoma Registry from 1990 to 2013 revealed that 898 patients (7.4%) developed 2,037 multiple primary lesions and 11,254 patients developed single lesions. The proportion of subsequent lesions that were melanoma in situ was 47%, compared with 26% of first melanomas (p<0.0001). The median time to diagnosis of a subsequent melanoma was 38 months (95% confidence interval (CI), 53-62 months). In total, 49% of subsequent melanomas were detected within 3 years. Patients and physicians should be aware of the high proportion of multiple primary melanomas in Western Sweden, especially during the first years of follow-up.
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| 4. |
- Hallberg, Stefan, 1955, et al.
(författare)
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Developing a simulation model for the patient pathway of cutaneous malignant melanoma
- 2015
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Ingår i: Operations Research for Health Care. - : Elsevier BV. - 2211-6923. ; 6, s. 23-30
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a system dynamic simulation model for a part of the patient pathway of cutaneous malignant melanoma was developed. A model was built that produced quantified out-put of diagnosed patients staged by severity, using System dynamic simulation. Data from the Swedish Melanoma Registry were combined with current scientific results and used in this analytical tool. Solutions to how these results are adapted into a simulation are described. The simulation model has the ability to generate alternative quantitative output of patient health in a population corresponding to realistic interventions in health care programmes as well as population and incidence development.
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| 5. |
- Hanstorp, Karl, et al.
(författare)
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Numerical Simulation and Experimental Scheme for Monitoring Hoof Wall Structure and Health in Sport Horses
- 2016
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Ingår i: Proceedings of the 4th International Congress on Sport Sciences Research and Technology Support. - : SCITEPRESS - Science and Technology Publications. - 9789897582059 ; , s. 171-175
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Konferensbidrag (refereegranskat)abstract
- This study provides a computational model developed to demonstrate the possibility of monitoring hoof structure and health in equestrian sport. This is achieved by employing finite element simulation of threedimensional heat flow from a surface heat source into a hoof structure while simultaneously sensing the surface temperature. The time evolution of the recorded surface temperature, transient curve, is used to investigate hoof structure and predict its intactness by comparing these curves for three different models. We have observed differences between the transient curves obtained from a normal hoof structure, a hoof structure containing a foreign material and hoof capsule subjected to wall separation. An experimental method for probing hoof profile was briefly discussed. It uses temperature sensor/heat source. The method can determine the thermal conductivity of the hoof along the hoof structure from the recorded transient curve. Thus, it displays the hoof structure by utilizing the thermal conductivity variation between the hoof parts.
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| 6. |
- Hedman, Daniel, et al.
(författare)
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On the Stability and Abundance of Single Walled Carbon Nanotubes
- 2015
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Many nanotechnological applications, using single-walled carbon nanotubes (SWNTs), are only possible with a uniform product. Thus, direct control over the product during chemical vapor deposition (CVD) growth of SWNT is desirable, and much effort has been made towards the ultimate goal of chirality-controlled growth of SWNTs. We have used density functional theory (DFT) to compute the stability of SWNT fragments of all chiralities in the series representing the targeted products for such applications, which we compare to the chiralities of the actual CVD products from all properly analyzed experiments. From this comparison we find that in 84% of the cases the experimental product represents chiralities among the most stable SWNT fragments (within 0.2 eV) from the computations. Our analysis shows that the diameter of the SWNT product is governed by the well-known relation to size of the catalytic nanoparticles, and the specific chirality is normally determined by the product's relative stability, suggesting thermodynamic control at the early stage of product formation. Based on our findings, we discuss the effect of other experimental parameters on the chirality of the product. Furthermore, we highlight the possibility to produce any tube chirality in the context of recent published work on seeded-controlled growth.
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| 7. |
- Mekonnen Mihiretie, Besira, 1983, et al.
(författare)
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Finite element modeling of the Hot Disc method
- 2017
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Ingår i: International Journal of Heat and Mass Transfer. - : Elsevier BV. - 0017-9310. ; 115, s. 216-223
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Tidskriftsartikel (refereegranskat)abstract
- The Hot Disc method, also known as the transient plane source (TPS) technique, is an experimental approach to determine the thermal transport properties of materials. The core of the method is the Hot Disc sensor, an electrically conducting metallic strip, shaped as a double spiral clad with a protective polymer film. The mean temperature increase in the sensor has been approximated from various analytical approaches such as: the concentric ring sources model, the thermal quadrupoles formalism, and concentric circular strips structure approach. However, full numerical simulation of the sensor has not been addressed so far. Here we develop a 3D model of Hot Disc sensors and compare simulated mean temperature increase to experimental recordings. Joule heating coupled with heat transfer of solids (of COMSOL Multiphysics software) is used to simulate the working principle of the sensor. The volume mean temperature increase in the sensor from the simulations proves to be in a good agreement with the corresponding experimental recordings. The temperature distributions of the metallic strip are also evaluated and discussed with respect to the previous experimental findings. Furthermore, the current distribution across the strip is obtained. Such simulation can potentially be used in further optimizing geometry and parameter estimation.
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| 8. |
- Mekonnen Mihiretie, Besira, 1983, et al.
(författare)
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SIMULATION OF THE HOT DISK SENSOR: TEMPERATURE AND ELECTRIC CURRENT DISTRIBUTION
- 2017
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Ingår i: Proceedings of the Asian Conference on Thermal Sciences 2017.
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Konferensbidrag (refereegranskat)abstract
- The Hot Disk method, also known as the transient plane source (TPS) technique, is an experimental approach for determining the thermal transport properties of materials. The core of the method is the Hot Disk sensor, an electrically conducting metallic foil (typically nickel), shaped as a double spiral, clad with a protective polymer film or mica. The double spiral serves simultaneously as heat source and temperature probe. The mean temperature increase of the TPS- sensor has been formulated from various analytical approaches such as: the concentric ring sources model, the thermal quadrupoles formalism, and concentric circular strips structure approach. However, full numerical simulation of the sensor has not been addressed so far. Here we develop 3D model of a Hot Disk sensor. The simulation provides information such as temperature and current distribution along each spiral which is not accessible from the experiment. Modeling feature, Joule heating coupled with heat transfer in solids of COMSOL Multiphysics software is used to simulate the sensor. The temperature and current distributions along the nickel wire is obtained. This can potentially be used in further optimizing geometry and estimating better parameters.
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| 9. |
- Mekonnen Mihiretie, Besira, 1983, et al.
(författare)
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Thermal depth profiling of materials for defect detection using hot disk technique
- 2016
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Ingår i: AIP Advances. - : AIP Publishing. - 2158-3226. ; 6:8
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Tidskriftsartikel (refereegranskat)abstract
- A novel application of the hot disk transient plane source technique is described. The new application yields the thermal conductivity of materials as a function of the thermal penetration depth which opens up opportunities in nondestructive testing of inhomogeneous materials. The system uses the hot disk sensor placed on the material surface to create a time varying temperature field. The thermal conductivity is then deduced from temperature evolution of the sensor, whereas the probing depth (the distance the heat front advanced away from the source) is related to the product of measurement time and thermal diffusivity. The presence of inhomogeneity in the structure is manifested in thermal conductivity versus probing depth plot. Such a plot for homogeneous materials provides fairly constant value. The deviation from the homogeneous curve caused by defects in the structure is used for inhomogeneity detection. The size and location of the defect in the structure determines the sensitivity and possibility of detection. In addition, a complementary finite element numerical simulation through COMSOL Multiphysics is employed to solve the heat transfer equation. Temperature field profile of a model material is obtained from these simulations. The average rise in temperature of the heat source is calculated and used to demonstrate the effect of the presence of inhomogeneity in the system.
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| 10. |
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| 11. |
- Sizov, Andrey, 1989, et al.
(författare)
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Thermal conductivity versus depth profiling of inhomogeneous materials using the hot disc technique
- 2016
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Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 1089-7623 .- 0034-6748. ; 87:7, s. 074901-
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Tidskriftsartikel (refereegranskat)abstract
- Transient measurements of thermal conductivity are performed with hot disc sensors on samples having a thermal conductivity variation adjacent to the sample surface. A modified computational approach is introduced, which provides a method of connecting the time-variable to a corresponding depth-position. This allows highly approximate—yet reproducible—estimations of the thermal conductivity vs. depth. Tests are made on samples incorporating different degrees of sharp structural defects at a certain depth position inside a sample. The proposed methodology opens up new possibilities to perform non-destructive testing; for instance, verifying thermal conductivity homogeneity in a sample, or estimating the thickness of a deviating zone near the sample surface (such as a skin tumor), or testing for presence of other defects
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| 12. |
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