| 1. |
- Andersson, Johan, 1972-
(författare)
-
Multiobjective optimization in engineering design : applications to fluid power systems
- 2001
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis focuses on how to improve design and development of complex engineering systems by employing simulation and optimization techniques. Within the thesis, methods are developed and applied to systems that combine mechanical, hydraulical and electrical subsystems, so-called multi-domain systems. Studied systems include a landing gear system for a civil aircraft, electrohydrostatic actuation systems for aircraft applications as well as hydraulic actuation systems.The usage of simulation and optimization in engineering design is gaining wider acceptance in all fields of industry as the computational capabilities of computers increase. Therefore, the applications for numerical optimization have increased dramatically. A great part of the design process is and will always be intuitive. Analytical techniques as well as numerical optimization could however be of great value and can permit vast improvements in design.Within the thesis, a framework is presented in which modeling and simulation are employed to predict the performance of a design. Additionally, non-gradient optimization techniques are coupled to the simulation models to automate the search for the best design.Engineering design problems often consist of several conflicting objectives. In many cases, the multiple objectives are aggregated into one single objective function. Optimization is then conducted with one optimal design as the result. The result is then strongly dependent on how the objectives are aggregated. Here a method is presented in which the Design Structure Matrix and the relationship matrix from the House of Quality method are applied to support the formulation of the objective function.Another approach to tackle multiobjective design problems is to employ the concept of Pareto optimality. Within this thesis a new multiobjective genetic algorithm is proposed and applied to support the design of a hydraulic actuation system. The outcome from such a multiobjective optimization is a set of Pareto optimal solutions that visualize the trade-off between the competing objectives. The proposed method is capable of handling a mix of continuous design variables and discrete selections of individual components from catalogs or databases.In real-world situations, system parameters will always include variations to some extent, and this fact is likely to influence the performance of the system. Therefore we need to answer not only the question "What is best?", but also "What is sufficiently robust?" Within this thesis, several approaches to handle these two different questions are presented.
|
|
| 2. |
- Hennings, Viktoria, et al.
(författare)
-
The presence of serum anti-SARS-CoV-2 IgA appears to protect primary health care workers from COVID-19.
- 2022
-
Ingår i: European journal of immunology. - : Wiley. - 1521-4141 .- 0014-2980. ; 52:5, s. 800-809
-
Tidskriftsartikel (refereegranskat)abstract
- The patterns of humoral and cellular responses to SARS-CoV-2 were studied in Swedish primary health care workers (n = 156) for 6 months during the Covid-19 pandemic. Serum IgA and IgG to SARS-CoV-2, T-cell proliferation and cytokine secretion, demographic and clinical data, PCR-verified infection, and self-reported symptoms were monitored. The multivariate method OPLS-DA was used to identify immune response patterns coupled to protection from Covid-19. Contracting Covid-19 was associated with SARS-CoV-2-specific neutralizing serum IgG, T cell, IFN-γ, and granzyme B responses to SARS-CoV-2, self-reported typical Covid-19 symptoms, male sex, higher BMI, and hypertension. Not contracting Covid-19 was associated with female sex, IgA-dominated, or no antibody responses to SARS-CoV-2, airborne allergy, and smoking. The IgG-responders had SARS-CoV-2-specific T-cell responses including a cytotoxic CD4+ T-cell population expressing CD25, CD38, CD69, CD194, CD279, CTLA-4, and granzyme B. IgA-responders with no IgG response to SARS-CoV-2 constituted 10% of the study population. The IgA responses were partially neutralizing and only seen in individuals who did not succumb to Covid-19. To conclude, serum IgG-dominated responses correlated with T-cell responses to SARS-CoV-2 and PCR-confirmed Covid-19, whereas IgA-dominated responses correlated with not contracting the infection.
|
|
| 3. |
- Wictor, Ingemar
(författare)
-
Born Globals : Rapid International Growth in New Ventures
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The traditional theories developed by Johanson and Vahlne (1977, 1990) and other researchers ofinternationalisation have long been questioned because of the fast-changing environment and deregulations. In particular, for Born Global firms, namely a company that has achieved a foreign sales volume of at least 25% within three years of its inception and that seeks to derive significant competitive advantage from the use of resources and the sales of outputs in multiple countries (Andersson and Wictor, 2003, p. 254), itis a question of surviving by establishing in many markets in a short period of time.This thesis summarises five papers. Paper 1 showed that the CEO´s perception and the fast changing environment push small firms to internationalise and that younger CEOs have an important role in expanding the firm. This is often because of their experiences accumulated inthe organisation over time or because the entrepreneur has been exposed to the international arena and information technologies, which can explain why some small firms continue to expandtheir international activities.The conceptual framework in paper 2 comprises four factors that influence Born Global firms:entrepreneurs, networks, industry and globalisation. To succeed in establishing a global firm it isimportant to have certain resources, such as an entrepreneur with international experience and strong networks. A Born Global entrepreneur is distinguished by his interest and motivation todo business abroad and his vision for the future.Paper 3 focuses on the importance of Born Globals’ foreign market channel strategies. The decision to establish a new market is of great importance for the long-term survival of the company. In this comparative case study, four companies that display different foreign entrymodes are compared. We found that these companies had very different market channel strategies even though they internationalised rapidly.Paper 4 is a study of four companies that indicates that their CEOs are active and involved in making strategic decisions in all parts of a Born Global firm’s value chain activities. Decisions on localisation and outsourcing are influenced by the entrepreneur’s definition of his firm’s core competencies. However, factors outside the firm are also an influence: potential suppliers,outsourcing of manufacturing and potential partners in distribution, especially relating to the riseof new emerging markets (e.g. China). The importance of coordinating value chain activities also influences the localisation of different activities. Entrepreneurs aim to arrange value-creating networks to secure their core manufacturing processes and close relations with local suppliers when they outsource products. In such a case, the entrepreneur can be seen as an orchestrator ina virtual organisation. The ‘global factory’ concept can be adjusted to fit locally for a Born Global company and its environment. Paper 5 focuses on a Born Global company’s way to grow and is a longitudinal study of acompany over 17 years (1990–2007) and its development in the different stages in the growth/life-cycle curve. From inception, the vision is already strong to go global. During thea bove period, the founder, external CEO I and CEO II were interviewed to assess whatcharacterises the different stages of growth over time compared with the growth/life-cycle model of Smallbone and Wyer (2006). The company is still growing and very entrepreneurial. The leadership has changed from a deciding style to a more coaching way of leading. Themanagement and organisation have changed to be more professionalised and team-oriented over8time. Entrepreneurial teams have also become more and more important for transferring knowledge to individuals in the organisation.The traditional models of Johanson and Vahlne (1977, 1990) point out that learning at an organisational level is a main factor in international development over time. However, a way to speed up the development of Born Global firms is entrepreneurial background with long experience and different knowledge serving his vision for the company. Nevertheless, theknowledge transfer from the entrepreneur and his team to the organisation is important. Knight and Cavusgil (2004, p. 137) find that “Born Globals pose an important new challenge to traditional views on the internationalization of the firm”.Johanson and Vahlne (2003) study what happens in companies because of rapid changes in the environment. They suggest that the Uppsala model is still valid, but that the early stage of a firm’sinternationalisation is important to study. Organisational learning is carried out at an individual and an entrepreneurial level. Johanson and Vahlne (1977) focus on the importance of the people working in a market and their learning. In their latest published article by Schweizer et al. (2010,pp. 368–369), they argue that “it is the liability of outsidership rather than the liability offoreignness that gives rise to internationalization difficulties. Outsidership implies that the firm isnot a member of relevant networks. Internationalization can be seen then as taking steps tobecome an insider in relevant networks in focal foreign markets … In their last study it emphasizes the entrepreneurial facets of a firm’s internationalization process”. The above defined background of the entrepreneur, his entrepreneurial way of working and his experience from former jobs also means that he already has the networks necessary for international expansion.The entrepreneur and his team in a Born Global company must from the beginning have the capability and knowledge of the environment and market in a country to establish in the new market as well as the understanding of how to manage the company and organisation. If they do not have this knowledge, they must have a network from which to extract this information. The entrepreneur has to be strongly involved in building and sustaining relationships with both customers and suppliers. In the organisation, he also has to build a powerful culture with decentralisation and empowered employees. The leadership in these companies is charismatic,employees are empowered in their jobs and the teams are entrepreneurial. Employees are therefore also allowed to make their own decisions within certain limits. Networks are important to overcome “perceived barriers on cultural and regulatory issues, those associated with locating partners, plus other matters deemed important to specific management teams” (Crick, 2009, p. 466). Coviello and Cox (2006) find that a company’s network is aresource when it is working with acquisitions and important recruitments. For companies growing over many years such as the Rubber Company studied herein, networks change and the chairman’s networks can be of great importance when core individuals should be recruited as an important part of the company’s strategies.
|
|
| 4. |
- Acevedo, Nathalie, et al.
(författare)
-
DNA Methylation Levels in Mononuclear Leukocytes from the Mother and Her Child Are Associated with IgE Sensitization to Allergens in Early Life
- 2021
-
Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 22:2
-
Tidskriftsartikel (refereegranskat)abstract
- DNA methylation changes may predispose becoming IgE-sensitized to allergens. We analyzed whether DNA methylation in peripheral blood mononuclear cells (PBMC) is associated with IgE sensitization at 5 years of age (5Y). DNA methylation was measured in 288 PBMC samples from 74 mother/child pairs from the birth cohort ALADDIN (Assessment of Lifestyle and Allergic Disease During INfancy) using the HumanMethylation450BeadChip (Illumina). PBMCs were obtained from the mothers during pregnancy and from their children in cord blood, at 2 years and 5Y. DNA methylation levels at each time point were compared between children with and without IgE sensitization to allergens at 5Y. For replication, CpG sites associated with IgE sensitization in ALADDIN were evaluated in whole blood DNA of 256 children, 4 years old, from the BAMSE (Swedish abbreviation for Children, Allergy, Milieu, Stockholm, Epidemiology) cohort. We found 34 differentially methylated regions (DMRs) associated with IgE sensitization to airborne allergens and 38 DMRs associated with sensitization to food allergens in children at 5Y (Sidak p <= 0.05). Genes associated with airborne sensitization were enriched in the pathway of endocytosis, while genes associated with food sensitization were enriched in focal adhesion, the bacterial invasion of epithelial cells, and leukocyte migration. Furthermore, 25 DMRs in maternal PBMCs were associated with IgE sensitization to airborne allergens in their children at 5Y, which were functionally annotated to the mTOR (mammalian Target of Rapamycin) signaling pathway. This study supports that DNA methylation is associated with IgE sensitization early in life and revealed new candidate genes for atopy. Moreover, our study provides evidence that maternal DNA methylation levels are associated with IgE sensitization in the child supporting early in utero effects on atopy predisposition.
|
|
| 5. |
- Acevedo, Nathalie, et al.
(författare)
-
Epigenetic alterations in skin homing CD4(+)CLA(+) T cells of atopic dermatitis patients
- 2020
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1
-
Tidskriftsartikel (refereegranskat)abstract
- T cells expressing the cutaneous lymphocyte antigen (CLA) mediate pathogenic inflammation in atopic dermatitis (AD). The molecular alterations contributing to their dysregulation remain unclear. With the aim to elucidate putative altered pathways in AD we profiled DNA methylation levels and miRNA expression in sorted T cell populations -(CD4(+), -CD4(+)CD45RA(+) naive, -CD4(+)CLA(+), and -CD8(+)) from adult AD patients and healthy controls (HC). Skin homing -CD4(+)CLA(+) T cells from AD patients showed significant differences in DNA methylation in 40 genes compared to HC (p < 0.05). Reduced DNA methylation levels in the upstream region of the interleukin-13 gene (IL13) in -CD4(+)CLA(+) T cells from AD patients correlated with increased IL13 mRNA expression in these cells. Sixteen miRNAs showed differential expression in -CD4(+)CLA(+) T cells from AD patients targeting genes in 202 biological processes (p < 0.05). An integrated network analysis of miRNAs and CpG sites identified two communities of strongly interconnected regulatory elements with strong antagonistic behaviours that recapitulated the differences between AD patients and HC. Functional analysis of the genes linked to these communities revealed their association with key cytokine signaling pathways, MAP kinase signaling and protein ubiquitination. Our findings support that epigenetic mechanisms play a role in the pathogenesis of AD by affecting inflammatory signaling molecules in skin homing -CD4(+)CLA(+) T cells and uncover putative molecules participating in AD pathways.
|
|
| 6. |
- af Edholm, Karolina, et al.
(författare)
-
Clinical Reasoning : Leg weakness and stiffness at the emergency room
- 2019
-
Ingår i: Neurology. - : Lippincott Williams & Wilkins. - 0028-3878 .- 1526-632X. ; 92:6, s. E622-E625
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- A 48-year-old woman from the Maghreb came to the emergency department with insidious gait difficulties, urgency, and constipation starting 6 months prior to the visit. The patient's complaints consisted of weakness, stiffness, and pain in her legs. Her medical history consisted of Hashimoto thyroiditis and breast cancer, with the latter having motivated surgery 4 months prior to admission. Histopathologic examination had demonstrated ductal cancer sensitive to estrogen and mapping with sentinel node biopsy ruled out metastasis. For that reason, the patient was treated with local radiation given weekly over 1 month and treatment with tamoxifen was started. Physical examination upon admission demonstrated weakness and spasticity in both legs. Reflexes were brisk; bilateral nonsustained foot clonus and Babinski sign were also present. Bilateral dorsal flexion was reduced, but vibration and sensation to touch and pinprick were normal. Sphincter tonus was reduced; systemic manifestations such as myalgias, fever, skin rashes, uveitis, sicca, and arthritic joints were absent.
|
|
| 7. |
- Allende, Ana, et al.
(författare)
-
Maximum levels of cross-contamination for 24 antimicrobial active substances in non-target feed. Part 2: Aminoglycosides/aminocyclitols: apramycin, paromomycin, neomycin and spectinomycin
- 2021
-
Ingår i: EFSA Journal. - : Wiley. - 1831-4732. ; 19:10
-
Tidskriftsartikel (refereegranskat)abstract
- The specific concentrations of apramycin, paromomycin, neomycin and spectinomycin in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield, were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties, are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. However, due to the lack of data on the parameters required to calculate the FARSC for these antimicrobials, it was not possible to conclude the assessment until further experimental data become available. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. Levels in feed that showed to have an effect on growth promotion/increased yield were reported for apramycin and neomycin, whilst for paromomycin and spectinomycin, no suitable data for the assessment were available. It was recommended to carry out studies to generate the data that are required to fill the gaps which prevented the calculation of the FARSC for these four antimicrobials.
|
|
| 8. |
|
|
| 9. |
- Andersson, Anna, et al.
(författare)
-
Evaluation of results and adaptation of EU Rural Development Programmes
- 2017
-
Ingår i: Land Use Policy. - : Elsevier BV. - 0264-8377 .- 1873-5754. ; 67, s. 298-314
-
Tidskriftsartikel (refereegranskat)abstract
- The EU Commission highlights evaluations as important for improving common policies. But do evaluations actually contribute? This paper examines whether this has been the case for the EU Rural Development Programmes (RDPs). We investigate 1) to what extent evaluations have influenced the design of national programmes and 2) if they have affected the Rural Development Regulation on which national programmes are based. Our main finding is that evaluations do not seem to affect future policy to any discernible degree. This is the case for both national programmes and the Regulation itself, which seems to have evolved in response to external pressures. Partly, this may be because evaluations tend to give vague or too general recommendations. Moreover, evaluations seldom apply counterfactual analysis, often because of a lack of data, implying that results may be methodologically questioned. Lastly, evaluations, and RDPs, are hard to locate and seldom translated from their native languages, impairing the possibilities of learning from the experiences of others.
|
|
| 10. |
- Andersson, Christer, et al.
(författare)
-
Trust in PRIME
- 2005
-
Ingår i: Proceedings of the 5<sup>th </sup>IEEE International Symposium on Signal Processing and IT. - : IEEE conference proceedings. - 0780393139 ; , s. 552-559
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The PRIME project develops privacy enhancing identity management systems that allow users in various application areas such as e-commerce to regain control over their personal spheres. This paper introduces the PRIME technical architecture that also includes special trust-enhancing mechanisms, and shows how PRIME technologies can enhance privacy and trust of e-shopping customers. It also discusses the socio-psychological factors and HCI aspects influencing the end user's trust in privacy enhancing identity management, and shows why HCI research, user studies, and socio-psychological research, are necessary efforts to accompany system design.
|
|
| 11. |
- Andersson, Dan I., et al.
(författare)
-
Antibiotic resistance : turning evolutionary principles into clinical reality
- 2020
-
Ingår i: FEMS Microbiology Reviews. - : Oxford University Press (OUP). - 0168-6445 .- 1574-6976. ; 44:2, s. 171-188
-
Forskningsöversikt (refereegranskat)abstract
- Antibiotic resistance is one of the major challenges facing modern medicine worldwide. The past few decades have witnessed rapid progress in our understanding of the multiple factors that affect the emergence and spread of antibiotic resistance at the population level and the level of the individual patient. However, the process of translating this progress into health policy and clinical practice has been slow. Here, we attempt to consolidate current knowledge about the evolution and ecology of antibiotic resistance into a roadmap for future research as well as clinical and environmental control of antibiotic resistance. At the population level, we examine emergence, transmission and dissemination of antibiotic resistance, and at the patient level, we examine adaptation involving bacterial physiology and host resilience. Finally, we describe new approaches and technologies for improving diagnosis and treatment and minimizing the spread of resistance.
|
|
| 12. |
- Andersson, Henric, 1963-, et al.
(författare)
-
Configuration Management of Models for Aircraft Simulation
- 2010
-
Ingår i: Proceedings of the 27th International Congress of the Aeronautical Sciences. ; , s. 10-
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Support for configuration and instantiation of large-scale aircraft simulations has become a major issue as the numbers of models grow, model fidelity increases and there is a trend to design models to allow reuse between simulation environments. In this work a method for configuration support is presented that is based on the Product Line principles with structures and data inherited from the Product Data Management system. An XML-based information object to carry product configuration data and knowledge between tools, called a CNA-string is introduced. A rule-based method to support specification of consistent configurations is adopted from the sales configuration domain. The application example is configurations of the Gripen fighter aircraft simulation models.
|
|
| 13. |
- Andersson, Lena, 1965, et al.
(författare)
-
Can avilability to psychiatric care explain regional differences in disability pension due to psychiatric disorders?
- 2005
-
Ingår i: Europen Journal of Public Health.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Background In previous studies we have found regional differences in rates of sick leave and disability pension (DP) with psychiatric diagnosis. Age and sex composition of the populations could not explain these differences. The aim of this study was to more closely study associations between availability of psychiatric health care staff and regional differences in DP due to psychiatric disorders in Norway. Methods The study base was all individuals 16-67 years in Norway (n = 2 668 827 in 2000) and six southern regions in 1990, 1995, 2000. As indicators of psychiatric health care we used numbers of psychiatrists, psychologists and psychiatric nurses/10 000 and numbers of in-patient beds, hospitalization days and numbers of discharges/10 000 in each region. A multiple linear regression model was used for the statistical analysis. Results Regional differences in disability pension with psychiatric diagnoses remained after controlling for availability to psychiatric care. In two semi rural regions the relative risk increased while it decreased in the capitol Oslo after control for availability for psychiatric care. There was an association between the frequency of DP:s and number of psychiatrists and other physicians (RR 1,49 (95%CI 1,37-1,61), psychologists (RR 1,29 (95% CI 1,23-1,36) and associated nurses (RR 0,84, 95%CI 0,80-0,88). No association was found between DP frequency and number of psychiatric nurses (RR 1,03 95% CI 1,00-1,06). Conclusions Incidence rates of DP with psychiatric diagnoses in different regions were associated with the number of psychiatric health care staff. Possible explanations to found positive associations can be an improved identification of psychiatric cases but future studies are needed regarding the role of professional psychiatric staff in vocational rehabilitation.
|
|
| 14. |
|
|
| 15. |
|
|
| 16. |
- Andersson, Lars Gustaf, et al.
(författare)
-
Rifbjerg!
- 2003
-
Ingår i: Finns en plats på jorden. - 9163145928
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Analysis of the poem "Rifbjerg!" by Danish writer Klaus Rifbjerg
|
|
| 17. |
|
|
| 18. |
|
|
| 19. |
|
|
| 20. |
|
|
| 21. |
|
|
| 22. |
- Andersson, Lena, 1965, et al.
(författare)
-
Regional differences in disability pensioning on the basis of psychiatric disorders in Norway
- 2004
-
Ingår i: Acta Psychiatrica Scandinavica. ; 110:Issue 421
-
Konferensbidrag (refereegranskat)abstract
- Objective: The incidence of disability pensions granted on the basis of a psychiatric diagnosis presents unexplained regional differences in Norway. The aim of this study was to analyse whether these differences were because of sex and age. Method: In this register-based study we compared in six Norwegian regions the incidence rates of disability pensions granted on the basis of a psychiatric diagnosis between 1988 and 2000. The population at risk comprised all individuals aged 16– 64 years in 1988 (n = 2 571 108) 1990 (n = 2 574 355), 1995 (n = 2 629 038) and 2000 (n = 2 668 827). Individuals already drawing a disability pension were excluded. Cases were those who drew a full- or part-time disability pension on the basis of a psychiatric diagnosis each year. Norway was used as the reference. Results: There were large regional differences, with one region presenting significantly increased SMR during the entire period. Among men the SMR was 1.28 (1.00–1.62 95% CI) in 1988 and 1.41 (1.14–1.71 95% CI) in 2000. Corresponding figures for women were 1.40 (1.14–1.74 95% CI) and 1.37 (1.13–1.67 95% CI). The most accentuated sex differences were found in the urban area Oslo. SMR among men was 1.17 (1.04–1.29 95% CI) in 1988 and 1.50 (1.38–1.63 95% CI) in 2000, while women presented a decreased risk in 1988, 0.87 (0.77–0.97 95% CI) and 1.16 (1.06–1.26 95% CI) in the year 2000. Conclusion: Increased risks remained after controlling for age and sex. Sex differences also varied between regions. Selection mechanisms and unemployment could be possible explanations,as could varying accessibility to the psychiatric health care system.
|
|
| 23. |
- Andersson, Martin, et al.
(författare)
-
A biokinetic and dosimetric model for ionic indium in humans
- 2017
-
Ingår i: Physics in Medicine and Biology. - : IOP Publishing. - 0031-9155 .- 1361-6560. ; 62:16, s. 6397-6407
-
Tidskriftsartikel (refereegranskat)abstract
- This paper reviews biokinetic data for ionic indium, and proposes a biokinetic model for systemic indium in adult humans. The development of parameter values focuses on human data and indium in the form of ionic indium(III), as indium chloride and indium arsenide. The model presented for systemic indium is defined by five different pools: plasma, bone marrow, liver, kidneys and other soft tissues. The model is based on two subsystems: one corresponding to indium bound to transferrin and one where indium is transported back to the plasma, binds to red blood cell transferrin and is then excreted through the kidneys to the urinary bladder. Absorbed doses to several organs and the effective dose are calculated for 111In- and 113mIn-ions. The proposed biokinetic model is compared with previously published biokinetic indium models published by the ICRP. The absorbed doses are calculated using the ICRP/ICRU adult reference phantoms and the effective dose is estimated according to ICRP Publication 103. The effective doses for 111In and 113mIn are 0.25 mSv MBq-1 and 0.013 mSv MBq-1 respectively. The updated biokinetic and dosimetric models presented in this paper take into account human data and new animal data, which represent more detailed and presumably more accurate dosimetric data than that underlying previous models for indium.
|
|
| 24. |
|
|
| 25. |
- Andersson, Martin, et al.
(författare)
-
An internal radiation dosimetry computer program, IDAC 2.0, for estimation of patient doses from radiopharmaceuticals
- 2014
-
Ingår i: Radiation Protection Dosimetry. - : Oxford University Press (OUP). - 0144-8420 .- 1742-3406. ; 162:3, s. 299-305
-
Tidskriftsartikel (refereegranskat)abstract
- The internal dosimetry computer program internal dose assessment by computer (IDAC) for calculations of absorbed doses to organs and tissues as well as effective doses to patients from examinations with radiopharmaceuticals has been developed. The new version, IDAC2.0, incorporates the International Commission on Radiation Protection (ICRP)/ICRU computational adult male and female voxel phantoms and decay data from the ICRP publication 107. Instead of only 25 source and target regions, calculation can now be made with 63 source regions to 73 target regions. The major advantage of having the new phantom is that the calculations of the effective doses can be made with the latest tissue weighting factors of ICRP publication 103. IDAC2.0 uses the ICRP human alimentary tract (HAT) model for orally administrated activity and for excretion through the gastrointestinal tract and effective doses have been recalculated for radiopharmaceuticals that are orally administered. The results of the program are consistent with published data using the same specific absorption fractions and also compared with published data from the same computational phantoms but with segmentation of organs leading to another set of specific absorption fractions. The effective dose is recalculated for all the 34 radiopharmaceuticals that are administered orally and has been published by the ICRP. Using the new HAT model, new tissue weighting factors and the new adult computational voxel phantoms lead to an average effective dose of half of its earlier estimated value. The reduction mainly depends on electron transport simulations to walled organs and the transition from the stylised phantom with unrealistic interorgan distances to more realistic voxel phantoms.
|
|
| 26. |
|
|
| 27. |
- Andersson, Martin, et al.
(författare)
-
An upgrade of the internal dosimetry computer program IDAC
- 2012
-
Ingår i: Medical Physics in the Baltic States. - : Kaunas University of Technology. - 1822-5721. ; , s. 120-123
-
Konferensbidrag (refereegranskat)abstract
- A full update of the internal dosimetry computer program IDAC has been conducted. The new update is based on new and more accurate computational phantoms to calculate effective dose and absorbed dose to organs and tissues. The new ICRP Adult Reference Computational Phantoms has been adopted as well as the latest of the ICRP standardized biokinetic models. The updated computer program includes a user-friendly graphical user interface.
|
|
| 28. |
|
|
| 29. |
- Andersson, Maria, et al.
(författare)
-
Delay of appropriate antibiotic treatment is associated with high mortality in patients with community-onset sepsis in a Swedish setting
- 2019
-
Ingår i: European Journal of Clinical Microbiology and Infectious Diseases. - : SPRINGER. - 0934-9723 .- 1435-4373. ; 38:7, s. 1223-1234
-
Tidskriftsartikel (refereegranskat)abstract
- Early appropriate antimicrobial therapy is crucial in patients with sepsis and septic shock. Studies often focus on time to first dose of appropriate antibiotics, but subsequent dosing is equally important. Our aim was to investigate the impact of fulfillment of early treatment, with focus on appropriate administration of first and second doses of antibiotics, on 28-day mortality in patients with community-onset severe sepsis and septic shock. A retrospective study on adult patients admitted to the emergency department with community-onset sepsis and septic shock was conducted 2012-2013. The criterion early appropriate antibiotic treatment was defined as administration of the first dose of adequate antibiotics within 1h, and the second dose given with less than 25% delay after the recommended dose interval. A high-risk patient was defined as a septic patient with either shock within 24h after arrival or red triage level on admittance according to the Medical Emergency Triage and Treatment System Adult. Primary endpoint was 28-day mortality. Of 90 patients, less than one in four (20/87) received early appropriate antibiotic treatment, and only one in three (15/44) of the high-risk patients. The univariate analysis showed a more than threefold higher mortality among high-risk patients not receiving early appropriate antibiotic treatment. Multivariable analysis identified early non-appropriate antibiotic treatment as an independent predictor of mortality with an odds ratio for mortality of 10.4. Despite that the importance of early antibiotic treatment has been established for decades, adherence to this principle was very poor.
|
|
| 30. |
- Andersson, Martin, et al.
(författare)
-
Dose management in conventional nuclear medicine imaging and PET
- 2016
-
Ingår i: Clinical and Translational Imaging. - : Springer Science and Business Media LLC. - 2281-5872 .- 2281-7565. ; 4:1, s. 21-30
-
Forskningsöversikt (refereegranskat)abstract
- This review of the basic concepts of dose management in conventional nuclear medicine imaging and positron emission tomography focuses on methods for dose assessment, difficulties with image quality evaluation, need for clear image quality criteria and observer performance studies, studies on representative groups of patients contra individual patients, clinically applicable methods for dose reduction, including the use of diagnostic reference levels. The dose management in nuclear imaging requires more attention and there is a need for better contribution of new technology for individual patient dose management as well as for education and training of the multidisciplinary teams of nuclear medicine physicians, technologists and medical physicists, responsible for the investigations.
|
|
| 31. |
|
|
| 32. |
- Andersson, Martin, et al.
(författare)
-
Effect of Assembly Errors in Back-to-Back Gear Efficiency Testing
- 2014
-
Ingår i: International Gear Conference 2014. - : Woodhead Publishing Limited. - 9781782421955 - 9781782421948 ; , s. 784-793
-
Konferensbidrag (refereegranskat)abstract
- As gear efficiency is improved in small steps, it is important to be able to distinguish actual improvements from scatter that can occur while testing. An FZG back-to-back gear test rig was used to investigate how the assembly and re-assembly of the same test setup affects the measurements. A spread in loss torque between one assembly and another of the same test setup were observed. Rig conditions also affected the spread in input torque. With knowledge of how the spread in loss torque varies due to assembly, test results could be distinguished between changes due to assembly and actual differences between tests.
|
|
| 33. |
- Andersson, Martin, et al.
(författare)
-
Effective dose to adult patients from 338 radiopharmaceuticals estimated using ICRP biokinetic data, ICRP/ICRU computational reference phantoms and ICRP 2007 tissue weighting factors
- 2014
-
Ingår i: EJNMMI Physics. - : Springer. - 2197-7364. ; 1:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Effective dose represents the potential risk to a population of stochastic effects of ionizing radiation (mainly lethal cancer). In recent years, there have been a number of revisions and updates influencing the way to estimate the effective dose. The aim of this work was to recalculate the effective dose values for the 338 different radiopharmaceuticals previously published by the International Commission on Radiological Protection (ICRP).Method: The new estimations are based on information on the cumulated activities per unit administered activity in various organs and tissues and for the various radiopharmaceuticals obtained from the ICRP publications 53, 80 and 106. The effective dose for adults was calculated using the new ICRP/International Commission on Radiation Units (ICRU) reference voxel phantoms and decay data from the ICRP publication 107. The ICRP human alimentary tract model has also been applied at the recalculations. The effective dose was calculated using the new tissue weighting factors from ICRP publications 103 and the prior factors from ICRP publication 60. The results of the new calculations were compared with the effective dose values published by the ICRP, which were generated with the Medical Internal Radiation Dose (MIRD) adult phantom and the tissue weighting factors from ICRP publication 60.Results: For 79% of the radiopharmaceuticals, the new calculations gave a lower effective dose per unit administered activity than earlier estimated. As a mean for all radiopharmaceuticals, the effective dose was 25% lower. The use of the new adult computational voxel phantoms has a larger impact on the change of effective doses than the change to new tissue weighting factors.Conclusion: The use of the new computational voxel phantoms and the new weighting factors has generated new effective dose estimations. These are supposed to result in more realistic estimations of the radiation risk to a population undergoing nuclear medicine investigations than hitherto available values.
|
|
| 34. |
- Andersson, Mathias H., 1976-
(författare)
-
Man-made structures as habitat for marine faunal assemblages
- 2008
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Artificial reefs are structures placed in the sea to promote marine life. Although constructions such as oil-rigs, wind farms, bridges and pier pilings are built for other purposes, they could be regarded as artificial reefs as they add new surfaces in the oceans, susceptible to colonization by marine organism. One of the most common constructions in the oceans is cylindrical structures of different materials. Most research of artificial reefs has been conducted in tropical and temperate water and experience and conclusions cannot always be applied to colder waters. Man-made constructions are common in northern European seas, however, few studies are presented in the scientific literature on their impact on the marine ecosystem. The aim of this thesis was to study cylindrical structures of different scale and materials, in order to determine their effect on local fish, algae and sessile invertebrate assemblages. These structures were offshore wind turbines, and pillars of different materials (concrete and steel), situated at the Swedish east and west coast, respectively. They add vertical surfaces into the otherwise empty water column, increasing the probability for fish and invertebrate larvae as well as algae spores and propagules to encounter these high structures, compared to low profile natural or other artificial reefs. Fish species usually associated with rocky reefs and algae communities, i.e. the two spotted goby and the goldsinny-wrasse, showed an increase in abundance around the introduced cylindrical structures. Similar effect on fish species were found on both the Swedish east and west coast. The observed increase in fish densities seemed to be caused by added habitat since the pillars and wind turbines provide shelter from predators as well as increased food availability. The latter was either due to the fouling assemblage or change in water movement. The environment created by the introduced structures functions both as nursery and spawning areas since juveniles, adults and gravid fish were recorded in close association with the structures. The fouling community on the vertical surfaces did not resemble the natural assemblages and a difference in recruitment and succession on the pillars of different materials were observed. Further, dissimilar fouling assemblages were observed with other species dominating the assemblages on a fifty year old light-house foundation compared to the seven year old wind turbines, both located in the same area. The sessile filter feeding invertebrates located on the foundations have an advantage in food accessibility towards individuals at the seabed, as the organisms on the foundations are constantly susceptible to the water passing by. In addition, by adding offshore structures in areas previously lacking hard surfaces, non-indigenous species could find new available habitat or the foundations can function as stepping stones into new geographical regions.
|
|
| 35. |
- Andersson, Mathias H., 1976-
(författare)
-
Offshore wind farms - ecological effects of noise and habitat alteration on fish
- 2011
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- There are large gaps in our understanding how fish populations are affected by the anthropogenic noise and the alteration of habitat caused by the construction and operation of offshore wind farms. These issues are of great importance as the construction of offshore wind farms will increase all over the world in the near future. This thesis studies these effects with a focus on fish. The wind turbine foundations function as artificial reefs and are colonized by invertebrates, algae and fish. The epibenthic assemblages are influenced by factors such as hydrographical parameters, time of submergence, distance to natural hard bottom, material and texture (PAPER I, II). Once an epibenthic assemblage has been developed, fish utilize it for different ecosystem services such as food, shelter, and spawning and nursery area. Benthic and semi-pelagic species show a stronger response to the introduced foundation than pelagic species, as it is the bottom habitat that has mainly been altered (PAPER I, II). Pelagic species could be positively affected by the increased food availability - but it takes time and the effect is local. Construction noise like pile driving creates high levels of sound pressure and acoustic particle motion in the water and seabed. This noise induces behavioural reactions in cod (Gadus morhua) and sole (Solea solea). These reactions could occur up to tens of kilometres distance from the source (PAPER III). During power production, the wind turbines generate a broadband noise with a few dominating tones (PAPER IV, V), which are detectable by sound pressure sensitive fish at a distance of several kilometres even though intense shipping occurs in the area. Motion sensitive species will only detect the turbine noise at around a ten meter distance. Sound levels are only high enough to possibly cause a behavioural reaction within meters from a turbine (PAPER IV, V).
|
|
| 36. |
- Andersson, Martin, 1983, et al.
(författare)
-
IDAC-Bio, A Software for Internal Dosimetry Based on the New ICRP Biokinetic Models and Specific Absorbed Fractions
- 2022
-
Ingår i: HEALTH PHYSICS. - 0017-9078 .- 1538-5159. ; 123:2, s. 165-172
-
Tidskriftsartikel (refereegranskat)abstract
- Radiation dosimetry is central to virtually all radiation safety applications, optimization, and research. It relates to various individuals and population groups and to miscellaneous exposure situations-including planned, existing, and emergency situations. The International Commission on Radiological Protection (ICRP) has developed a new computational framework for internal dose estimations. Important components are more detailed and improved anatomical models and more realistic biokinetic models than before. The ICRP is currently producing new organ dose and effective dose coefficients for occupational intakes of radionuclides (OIR) and environmental intakes of radionuclides (EIR), which supersede the earlier dose coefficients in Publication 68 and the Publication 72 series, respectively. However, the ICRP only publishes dose coefficients for a single acute intake of a radionuclide and for an integration period of 50 years for intake by adults and to age 70 years for intakes by pre-adults. The new software, IDAC-Bio, performs committed absorbed dose and effective dose calculations for a selectable intake scenario, e.g., for a continuous intake or an intake during x hours per day and y days per week, and for any selected integration time. The software uses the primary data and models of the ICRP biokinetic models and numerically solves the biokinetic model and calculates the absorbed doses to organs and tissues in the ICRP reference human phantoms. The software calculates absorbed dose using the nuclear decay data in ICRP publication 107. IDAC-Bio is a further development and an important addition to the internal dosimetry program IDAC-Dose2.1. The results generated by the software were validated against published ICRP dose coefficients. The potential of the software is illustrated by dose calculations for a nuclear power plant worker who had been exposed to varying levels of Co-60 and who had undergone repeated whole-body measurements, and for a hypothetical member of the public subject to future releases of Gd-148 from neutron spallation in tungsten at the European Spallation Source.
|
|
| 37. |
|
|
| 38. |
- Andersson, Martin, et al.
(författare)
-
IDAC-CAD2VOX : A software for radiation protection calculations for the ICRP reference phantoms which are in an environment described by detailed cad drawings
- 2017
-
Ingår i: Medical Physics in the Baltic States : Proceedings of the 13th International Conference on Medical Physics. ; , s. 10-13
-
Konferensbidrag (refereegranskat)abstract
- A computer program called IDAC-CAD2VOX has been constructed to create geometry input files from CAD drawings for the Monte Carlo simulation program MCNP. The ICRP reference phantoms are incorporated into the CAD drawings to estimate organ doses and the effective dose. The program is applied to a CAD drawing of a house and a 2D drawing of a radiation protection bunker. The created MCNP geometry was visualised by an external program Visual Editor. Dose calculations were performed for a CAD -drawing of a house, where a point source of 1 GBq 99mTc was placed in the attic. The effective dose to the adult male ICRP reference phantom was estimated to be 7.0 µSv when placed in the living room on the second floor. In summary, a method has been developed to enable effective dose estimations to adults directly from CAD files and to present the results in a pedagogic and easily understandable way.
|
|
| 39. |
- Andersson, Martin, et al.
(författare)
-
IDAC-Dose 2.1, an internal dosimetry program for diagnostic nuclear medicine based on the ICRP adult reference voxel phantoms
- 2017
-
Ingår i: EJNMMI Research. - : Springer Berlin/Heidelberg. - 2191-219X. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- Background: To date, the estimated radiation-absorbed dose to organs and tissues in patients undergoing diagnostic examinations in nuclear medicine is derived via calculations based on models of the human body and the biokinetic behaviour of the radiopharmaceutical. An internal dosimetry computer program, IDAC-Dose2.1, was developed based on the International Commission on Radiological Protection (ICRP)-specific absorbed fractions and computational framework of internal dose assessment given for reference adults in ICRP Publication 133. The program uses the radionuclide decay database of ICRP Publication 107 and considers 83 different source regions irradiating 47 target tissues, defining the effective dose as presented in ICRP Publications 60 and 103. The computer program was validated against another ICRP dosimetry program, Dose and Risk Calculation (DCAL), that employs the same computational framework in evaluation of occupational and environmental intakes of radionuclides. IDAC-Dose2.1 has a sub-module for absorbed dose calculations in spherical structures of different volumes and composition; this sub-module is intended for absorbed dose estimates in radiopharmaceutical therapy. For nine specific alpha emitters, the absorbed dose contribution from their decay products is also included in the committed absorbed dose calculations. Results: The absorbed doses and effective dose of I-131-iodide determined by IDAC-Dose2.1 were validated against the dosimetry program DCAL, showing identical results. IDAC-Dose2.1 was used to calculate absorbed doses for intravenously administered F-18-FDG and orally administered Tc-99m-pertechnetate and I-131-iodide, three frequently used radiopharmaceuticals. Using the tissue weighting factors from ICRP Publication 103, the effective dose per administered activity was estimated to be 0.016 mSv/MBq for F-18-FDG, 0.014 mSv/MBq for Tc-99m-pertechnetate, and 16 mSv/MBq for I-131-iodide. Conclusions: The internal dosimetry program IDAC-Dose2.1 was developed and applied to three radiopharmaceuticals for validation against DCAL and to generate improved absorbed dose estimations for diagnostic nuclear medicine using specific absorbed fraction values of the ICRP computational voxel phantoms. The sub-module for absorbed dose calculations in spherical structures 1 mm to 9 cm in diameter and different tissue composition was included to broaden the clinical usefulness of the program. The IDAC-Dose2.1 program is free software for research and available for download at http://www.idac-dose.org.
|
|
| 40. |
|
|
| 41. |
|
|
| 42. |
- Andersson, Martin, et al.
(författare)
-
Improved age and gender specific radiation risk models applied on cohorts of Swedish patients
- 2021
-
Ingår i: Radiation Protection Dosimetry. - : Oxford University Press (OUP). - 0144-8420 .- 1742-3406. ; 195:3-4, s. 334-338
-
Tidskriftsartikel (refereegranskat)abstract
- AIM:The aim of this study is to implement lifetime attributable risk (LAR) predictions for radiation induced cancers for Swedish cohorts of patients of various age and sex, undergoing diagnostic investigations by nuclear medicine methods. METHODS: Calculations are performed on Swedish groups of patients with Paget's disease and with bone metastases from prostatic cancer and diagnosed with bone scintigraphy with an administration of 500 MBq 99mTc-phosphonate. RESULTS: The inclusion of patient survival rates into the calculations lowers the induced radiation cancer risk, as it takes into account that cohorts of patients have shorter predicted survival times than the general population. CONCLUSION: LAR estimations could be valuable for referring physicians, nuclear medicine physicians, nurses, medical physicists, radiologists, and oncologists and as well as ethical committees for risk estimates for specific subgroups of patients. Caution is however advised with respect to application of LAR predictions to individuals (because of individual sensitivities, circumstances, etc.).
|
|
| 43. |
- Andersson, Martin, et al.
(författare)
-
Improved estimates of the radiation absorbed dose to the urinary bladder wall
- 2014
-
Ingår i: Physics in Medicine and Biology. - : Institute of Physics Publishing (IOPP). - 0031-9155 .- 1361-6560. ; 59:9, s. 2173-2182
-
Tidskriftsartikel (refereegranskat)abstract
- Specific absorbed fractions (SAFs) have been calculated as a function of the content in the urinary bladder in order to allow more realistic calculations of the absorbed dose to the bladder wall. The SAFs were calculated using the urinary bladder anatomy from the ICRP male and female adult reference computational phantoms. The urinary bladder and its content were approximated by a sphere with a wall of constant mass, where the thickness of the wall depended on the amount of urine in the bladder. SAFs were calculated for males and females with 17 different urinary bladder volumes from 10 to 800 mL, using the Monte Carlo computer program MCNP5, at 25 energies of mono-energetic photons and electrons ranging from 10 KeV to 10 MeV. The decay was assumed to be homogeneously distributed in the urinary bladder content and the urinary bladder wall, and the mean absorbed dose to the urinary bladder wall was calculated. The Monte Carlo simulations were validated against measurements made with thermoluminescent dosimeters. The SAFs obtained for a urine volume of 200 mL were compared to the values calculated for the urinary bladder wall using the adult reference computational phantoms. The mean absorbed dose to the urinary wall from F-18-FDG was found to be 77 mu Gy/MBq formales and 86 mu Gy/MBq for females, while for (99)mTc-DTPA the mean absorbed doses were 80 mu Gy/MBq for males and 86 mu Gy/MBq for females. Compared to calculations using a constant value of the SAF from the adult reference computational phantoms, the mean absorbed doses to the bladder wall were 60% higher for F-18-FDG and 30% higher for (99)mTc-DTPA using the new SAFs.
|
|
| 44. |
- Andersson, Martin, et al.
(författare)
-
Improved Patient Dosimetry at Radioiodine Therapy by Combining the ICRP Compartment Model and the EANM Pre-Therapeutic Standard Procedure for Benign Thyroid Diseases
- 2021
-
Ingår i: Frontiers in Endocrinology. - : Frontiers Media SA. - 1664-2392. ; 12
-
Tidskriftsartikel (refereegranskat)abstract
- Radioactive iodine is commonly used for the treatment of different thyroid conditions since the 1940s. The EANM has developed a standard pre-therapeutic procedure to estimate patient specific thyroid uptake at treatment of benign thyroid diseases. The procedure which models the time dependent fractional thyroid uptake is based on a two-compartment fitting system, one representing the thyroid and the other the blood. The absorbed dose is however only estimated for the thyroid and not for any other organ in the body. A more detailed biokinetic model for iodine is given by the ICRP and includes an iodide transport in the whole body. The ICRP model has 30 different compartments and 48 transfer coefficients to model the biokinetics of iodide and to model different transfer for inorganic iodide and organic iodine. The ICRP model is a recirculation iodine model, and the optimization is performed on the whole model and not exclusively on the thyroid as in the EANM procedure. Combining the EANM method and the ICRP model gives both patient specific estimations of thyroid uptake and retention and include most organs in the body. The new software gives both an improved patient specific dosimetry for the thyroid and an estimation of the absorbed dose to non-target organs and tissues like kidneys, urinary bladder, stomach wall, and uterus. Using the method described in this paper, the repercussions on the daily routines will be minimal.
|
|
| 45. |
- Andersson, Martin, et al.
(författare)
-
Improved radiation risk models applied to different patient groups in Sweden
- 2019
-
Ingår i: Radiatsionnaya Gygiena. - 1998-426X. ; 12:2, s. 44-54
-
Tidskriftsartikel (refereegranskat)abstract
- In radiological diagnostics and therapy, it is important that practitioners, referrers, (i.e. radiologists, radiation oncologists and others in healthcare) are aware of how much radiation a patient may receive from the various procedures used and associated health risk. The profession has a duty to inform patients or their representatives of the advantages and disadvantages of specific investigations or treatment plans. The need to estimate and communicate risks in connection with medical use of ionizing radiation is highlighted e.g. in the Russian Federation State Law No 3, §17.2, 1996 and in the EU directive (2013/59/EURATOM 2014). The most commonly used way to express harm in relation to low doses of ionizing radiation is use of the quantity effective dose (E). Effective dose, a radiation protection quantity, however is not intended to provide risk estimates for medical exposures. Its purpose is to optimize conditions for radiation workers (1865 years) or the general public; all groups with age distributions that differ from patients. In this paper the lifetime attributable risk was used to estimate the excess risk of receiving and dying of radiogenic cancer. The lifetime attributable risk estimations are generated from three different variables, gender, attained age and age at exposure giving the possibility to create age and gender specific cancer risk estimations. Initially, the US Environmental Protection Agency lifetime attributable risk coefficients which are intended to predict the cancer risk from ionizing radiation to a normal US population were applied. In this work, the lifetime attributable risk predictions were modified to the normal Swedish population and to cohorts of Swedish patients undergoing radiological and nuclear medicine examinations or treatments with survival times that differ from the normal population. For Swedish males, all organs were given the same absorbed dose, exposed at 20, 40 and 70 years, the lifetime attributable risk coefficients (Gy1) were 0.11, 0.068, and 0.038, respectively, which is lower than the corresponding figures for US males, 0.13, 0.077, and 0.040. For Swedish females, all organs were given the same absorbed dose, exposed at 40 years of age with a diagnosis of breast, colon or liver cancer, the lifetime attributable risk coefficients are 0.064, 0.034, and 0.0038, respectively, which is much lower than if a 40 years female without known cancer is exposed, 0.073.
|
|
| 46. |
- Andersson, Martin, et al.
(författare)
-
Lifetime attributable risk as an alternative to effective dose to describe the risk of cancer for patients in diagnostic and therapeutic nuclear medicine
- 2017
-
Ingår i: Physics in Medicine and Biology. - : IOP Publishing. - 0031-9155 .- 1361-6560. ; 62:24, s. 9177-9188
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study is to implement lifetime attributable risk (LAR) predictions of cancer for patients of various age and gender, undergoing diagnostic investigations or treatments in nuclear medicine and to compare the outcome with a population risk estimate using effective dose and the International Commission on Radiological Protection risk coefficients. The radiation induced risk of cancer occurrence (incidence) or death from four nuclear medicine procedures are estimated for both male and female between 0 and 120 years. Estimations of cancer risk are performed using recommended administered activities for two diagnostic (18F-FDG and 99mTc-phosphonate complex) and two therapeutic (131I-iodide and 223Ra-dichloride) radiopharmaceuticals to illustrate the use of cancer risk estimations in nuclear medicine. For 18F-FDG, the cancer incidence for a male of 5, 25, 50 and 75 years at exposure is 0.0021, 0.0010, 0.0008 and 0.0003, respectively. For 99mTc phosphonates complex the corresponding values are 0.000 59, 0.000 34, 0.000 27 and 0.000 13, respectively. For an 131I-iodide treatment with 3.7 GBq and 1% uptake 24 h after administration, the cancer incidence for a male of 25, 50 and 75 years at exposure is 0.041, 0.029 and 0.012, respectively. For 223Ra-dichloride with an administration of 21.9 MBq the cancer incidence for a male of 25, 50 and 75 years is 0.31, 0.21 and 0.09, respectively. The LAR estimations are more suitable in health care situations involving individual patients or specific groups of patients than the health detriment based on effective dose, which represents a population average. The detriment consideration in effective dose adjusts the cancer incidence for suffering of non-lethal cancers while LAR predicts morbidity (incidence) or mortality (cancer). The advantages of these LARs are that they are gender and age specific, allowing risk estimations for specific patients or subgroups thus better representing individuals in health care than effective dose.
|
|
| 47. |
- Andersson, My, et al.
(författare)
-
Optogenetic control of human neurons in organotypic brain cultures
- 2016
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
-
Tidskriftsartikel (refereegranskat)abstract
- Optogenetics is one of the most powerful tools in neuroscience, allowing for selective control of specific neuronal populations in the brain of experimental animals, including mammals. We report, for the first time, the application of optogenetic tools to human brain tissue providing a proof-of-concept for the use of optogenetics in neuromodulation of human cortical and hippocampal neurons as a possible tool to explore network mechanisms and develop future therapeutic strategies.
|
|
| 48. |
- Andersson, Martin, et al.
(författare)
-
ORGAN DOSES AND EFFECTIVE DOSE FOR FIVE PET RADIOPHARMACEUTICALS
- 2016
-
Ingår i: Radiation Protection Dosimetry. - : Oxford University Press (OUP). - 1742-3406 .- 0144-8420. ; 169:1-4, s. 8-253
-
Tidskriftsartikel (refereegranskat)abstract
- Diagnostic investigations with positron-emitting radiopharmaceuticals are dominated by (18)F-fluorodeoxyglucose ((18)F-FDG), but other radiopharmaceuticals are also commercially available or under development. Five of them, which are all clinically important, are (18)F-fluoride, (18)F-fluoroethyltyrosine ((18)F-FET), (18)F-deoxyfluorothymidine ((18)F-FLT), (18)F-fluorocholine ((18)F-choline) and (11)C-raclopride. To estimate the potential risk of stochastic effects (mainly lethal cancer) to a population, organ doses and effective dose values were updated for all five radiopharmaceuticals. Dose calculations were performed using the computer program IDAC2.0, which bases its calculations on the ICRP/ICRU adult reference voxel phantoms and the tissue weighting factors from ICRP publication 103. The biokinetic models were taken from ICRP publication 128. For organ doses, there are substantial changes. The only significant change in effective dose compared with previous estimations was a 46 % reduction for (18)F-fluoride. The estimated effective dose in mSv MBq(-1) was 1.5E-02 for (18)F-FET, 1.5E-02 for (18)F-FLT, 2.0E-02 for (18)F-choline, 9.0E-03 for (18)F-fluoride and 4.4E-03 for (11)C-raclopride.
|
|
| 49. |
|
|
| 50. |
- Andersson, Sören, et al.
(författare)
-
A random wear model for the interaction between a rough and a smooth surface
- 2008
-
Ingår i: Wear. - : Elsevier BV. - 0043-1648 .- 1873-2577. ; 264:9-10, s. 763-769
-
Tidskriftsartikel (refereegranskat)abstract
- Contact surfaces in many applications change form due to plastic and elastic deformation and to wear. This study focused on the plastic deformation and wear of the asperities on a rough surface rubbing against an opposite smooth, hard and wear-resistant surface. A stochastic model for the prediction of plastic deformations and wear of a rough surface is proposed. The surface roughness and the interaction between the surfaces are also represented by stochastic models. A single asperity is studied as it comes into contact and interacts with the opposite surface. Since the wear process is simulated as an initial-value problem, the proposed general wear model is formulated as a first order differential equation system representing events during the rubbing process at all of the asperities considered on a surface.
|
|
