| 1. |
- Moberg, Christina, et al.
(författare)
-
De unga gör helt rätt när de stämmer staten
- 2022
-
Ingår i: Aftonbladet. - 1103-9000.
-
Tidskriftsartikel (populärvet., debatt m.m.)abstract
- 1 620 forskare och lärare i forskarvärlden: Vi ställer oss bakom Auroras klimatkrav
|
|
| 2. |
- Frank, Catharina, 1961-, et al.
(författare)
-
Ethics rounds in the ambulance service: a qualitative evaluation
- 2024
-
Ingår i: BMC Medical Ethics. - : Springer Nature. - 1472-6939. ; 25:1
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundIt is a common ethical challenge for ambulance clinicians to care for patients with impaired decision-making capacities while assessing and determining the degree of decision-making ability and considering ethical values. Ambulance clinicians’ ethical competence seems to be increasingly important in coping with such varied ethical dilemmas. Ethics rounds is a model designed to promote the development of ethical competence among clinicians. While standard in other contexts, to the best of our knowledge, it has not been applied within the ambulance service context. Thus, the aim of this study was to describe ambulance clinicians’ experiences of participating in ethics rounds.MethodsThis was a qualitative descriptive study, evaluating an intervention. Data were collected through sixteen interviews with ambulance clinicians who had participated in an intervention involving ethics rounds. The analysis was performed by use of content analysis.ResultsTwo themes describe the participants’ experiences: (1) Reflecting freely within a given framework, and (2) Being surprised by new insights. The following categories form the basis of the themes; 1a) Gentle guidance by the facilitator, 1b) A comprehensible structure, 2a) New awareness in the face of ethical problems, and 2b) Shared learning through dialogue.ConclusionIncorporating structured ethics rounds seems to create a continuous development in ethical competence that may improve the quality of care in the ambulance service. Structured guidance and facilitated group reflections offer ambulance clinicians opportunities for both personal and professional development. An important prerequisite for the development of ethical competence is a well-educated facilitator. Consequently, this type of ethics rounds may be considered a useful pedagogical model for the development of ethical competence in the ambulance service.
|
|
| 3. |
- Hedén, Birger, et al.
(författare)
-
Förord
- 2008
-
Ingår i: Theorier om verklig diktning. Festskrift till Per Erik Ljung.
-
Bokkapitel (populärvet., debatt m.m.)
|
|
| 4. |
- Holmberg, L. Joakim, 1971-
(författare)
-
Musculoskeletal Biomechanics in Cross-country Skiing
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Why copy the best athletes? When you finally learn their technique, they may have already moved on. Using muscluloskeletal biomechanics you might be able to add the "know-why" so that you can lead, instead of being left in the swells.This dissertation presents the theoretical framework of musculoskeletal modeling using inverse dynamics with static optimization. It explores some of the possibilities and limitations of musculoskeletal biomechanics in cross-country skiing, especially double-poling. The basic path of the implementation is shown and discussed, e.g. the issue of muscle model choice. From that discussion it is concluded that muscle contraction dynamics is needed to estimate individual muscle function in double-poling. Several computer simulation models, using The Anybody Modeling System™, have been created to study different cross-country skiing applications. One of the applied studies showed that the musculoskeletal system is not a collection of discrete uncoupled parts because kinematic differences in the lower leg region caused kinetic differences in the other end of the body. An implication of the results is that the kinematics and kinetics of the whole body probably are important when studying skill and performance in sports. Another one of the applied studies showed how leg utilisation may affect skiing efficiency and performance in double-poling ergometry. Skiing efficiency was defined as skiing work divided by metabolic muscle work, performance was defined as forward impulse. A higher utilization of the lower-body increased the performance, but decreased the skiing efficiency. The results display the potential of musculoskeletal biomechanics for skiing efficiency estimations. The subject of muscle decomposition is also studied. It is shown both analytically and with numerical simulations that muscle force estimates may be affected by muscle decomposition depending on the muscle recruitment criteria. Moreover, it is shown that proper choices of force normalization factors may overcome this issue. Such factors are presented for two types of muscle recruitment criteria.To sum up, there are still much to do regarding both the theoretical aspects as well as the practical implementations before predictions on one individual skier can be made with any certainty. But hopefully, this disseration somewhat furthers the fundamental mechanistic understanding of cross-country skiing, and shows that musculoskeletal biomechanics will be a useful complement to existing experimental methods in sports biomechanics.
|
|
| 5. |
- Thellenberg-Karlsson, Camilla, 1972-, et al.
(författare)
-
A randomised, double-blind, dose-finding, phase II multicentre study of ODX in the treatment of patients with castration-resistant prostate cancer and skeletal metastases
- 2023
-
Ingår i: European Journal of Cancer. - : Elsevier. - 0959-8049 .- 1879-0852. ; 181, s. 198-207
-
Tidskriftsartikel (refereegranskat)abstract
- Aims: This study aimed to assess the efficacy and safety of ODX, a novel, cytotoxic, bone-targeting drug candidate, in castration-resistant prostate cancer bone metastatic disease.Methods: Patients with progressive disease were randomised to ten cycles of ODX, intravenous infusion Q2W (3, 6, and 9 mg/kg, respectively). The primary objective was to assess the relative change from baseline in bone alkaline phosphatase (B-ALP) and serum-aminoterminal-propeptide of Type I procollagen (S-P1NP) at 12 weeks. The inclusion criteria selected were broad, and a double-blind design was used to ensure objective recruitment of patients for the assessment of efficacy. None of the patients received bone-protecting agents during the ODX treatment period.Results: Fifty-five 21,20 and 14) patients were randomised to ODX (3, 6 and 9 mg/kg), respectively. The lower number of patients in arm 3 was due to too low a recruitment rate towards the end of the study. The median treatment time were 14, 13 and 14 weeks, respectively. The decrease in B-ALP at 12 weeks in study arms 3, 6 and 9 mg/kg was seen in 6/15 (40%), 8/12 (67%) and 5/12 (42%) patients, respectively, whereas the corresponding numbers for P1NP were 8/15 (53%), 8/12 (67%), and 4/12 (33%), respectively. The median decrease in B-ALP and P1NP at 12 weeks for study arms 3, 6 and 9 mg/kg were 37%, 14% and 43%, respectively, and 51%, 40% and 64%, respectively. The decrease in serum C-terminal telopeptide at 12 weeks was seen in the vast majority of patients and in about one-third of patients in bone scan index. ODX was well tolerated, and no drug-related serious adverse events occurred. There were no significant differences between study arms regarding efficacy and safety.Conclusions: ODX was well tolerated and demonstrated inhibitory effects on markers related to the vicious cycle in bone at all three doses. The reduction in metastatic burden, assessed with bone scan index, supports this finding. Studies with continued ODX treatment until disease progression are being planned (ClinicalTrials.gov Identifier: NCT02825628).
|
|
| 6. |
- Adolfsson, Jan, et al.
(författare)
-
Clinical characteristics and primary treatment of prostate cancer in Sweden between 1996 and 2005 : Data from the national prostate cancer register in Sweden
- 2007
-
Ingår i: Scandinavian Journal of Urology and Nephrology. - Stockholm : Taylor & Francis. - 0036-5599 .- 1651-2065. ; 41:6, s. 456-477
-
Tidskriftsartikel (refereegranskat)abstract
- Objective. The incidence of prostate cancer is rising rapidly in Sweden and there is a need to better understand the pattern of diagnosis, tumor characteristics and treatment. Material and methods. Between 1996 and 2005, all new cases of adenocarcinoma of the prostate gland were intended to be registered in the National Prostate Cancer Register (NPCR). This register contains information on diagnosing unit, date of diagnosis, cause of diagnosis, tumor grade, tumor stage according to the TNM classification in force, serum prostate-specific antigen (PSA) levels at diagnosis and primary treatment given within the first 6 months after diagnosis. Results. In total, 72 028 patients were registered, comprising >97% of all pertinent incident cases of prostate cancer in the Swedish Cancer Register (SCR). During the study period there was a considerable decrease in median age at the time of diagnosis, a stage migration towards smaller tumors, a decrease in median serum PSA values at diagnosis, a decrease in the age-standardized incidence rate of men diagnosed with distant metastases or with a PSA level of >100 ng/ml at diagnosis and an increase in the proportion of tumors with Gleason score ≤6. Relatively large geographical differences in the median age at diagnosis and the age-standardized incidence of cases with category T1c tumors were observed. Treatment with curative intent increased dramatically and treatment patterns varied according to geographical region. In men with localized tumors and a PSA level of <20 ng/ml at diagnosis, expectant treatment was more commonly used in those aged ≥75 years than in those aged <75 years. Also, the pattern of endocrine treatment varied in different parts of Sweden. Conclusions. All changes in the register seen over time are consistent with increased diagnostic activity, especially PSA testing, resulting in an increased number of cases with early disease, predominantly tumors in category T1c. The patterns of diagnosis and treatment of prostate cancer vary considerably in different parts of Sweden. The NPCR continues to be an important source for research, epidemiological surveillance of the incidence, diagnosis and treatment of prostate cancer
|
|
| 7. |
- Adolfsson, Jan, et al.
(författare)
-
Clinical characteristics and primary treatment of prostate cancer in Sweden between 1996 and 2005
- 2007
-
Ingår i: Scandinavian Journal of Urology and Nephrology. - : Informa UK Limited. - 0036-5599 .- 1651-2065. ; 41:6, s. 456-477
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The incidence of prostate cancer is rising rapidly in Sweden and there is a need to better understand the pattern of diagnosis, tumor characteristics and treatment. MATERIAL AND METHODS: Between 1996 and 2005, all new cases of adenocarcinoma of the prostate gland were intended to be registered in the National Prostate Cancer Register (NPCR). This register contains information on diagnosing unit, date of diagnosis, cause of diagnosis, tumor grade, tumor stage according to the TNM classification in force, serum prostate-specific antigen (PSA) levels at diagnosis and primary treatment given within the first 6 months after diagnosis. RESULTS: In total, 72,028 patients were registered, comprising >97% of all pertinent incident cases of prostate cancer in the Swedish Cancer Register (SCR). During the study period there was a considerable decrease in median age at the time of diagnosis, a stage migration towards smaller tumors, a decrease in median serum PSA values at diagnosis, a decrease in the age-standardized incidence rate of men diagnosed with distant metastases or with a PSA level of > 100 ng/ml at diagnosis and an increase in the proportion of tumors with Gleason score <6. Relatively large geographical differences in the median age at diagnosis and the age-standardized incidence of cases with category T1c tumors were observed. Treatment with curative intent increased dramatically and treatment patterns varied according to geographical region. In men with localized tumors and a PSA level of <20 ng/ml at diagnosis, expectant treatment was more commonly used in those aged > or =75 years than in those aged <75 years. Also, the pattern of endocrine treatment varied in different parts of Sweden. CONCLUSIONS: All changes in the register seen over time are consistent with increased diagnostic activity, especially PSA testing, resulting in an increased number of cases with early disease, predominantly tumors in category T1c. The patterns of diagnosis and treatment of prostate cancer vary considerably in different parts of Sweden. The NPCR continues to be an important source for research, epidemiological surveillance of the incidence, diagnosis and treatment of prostate cancer.
|
|
| 8. |
- Allen, D.H., et al.
(författare)
-
Modeling the viscoelastic response of GMT structural components
- 2001
-
Ingår i: Composites Science And Technology. - 0266-3538 .- 1879-1050. ; 61:4, s. 503-515
-
Tidskriftsartikel (refereegranskat)abstract
- A glass-mat-reinforced thermoplastic (GMT) composite material has been fabricated from randomly oriented continuous glass fibers embedded in a polypropylene matrix. The mechanical constitution of this composite has been characterized by using a linear viscoelastic micromechanically based material model. This material model has subsequently been implemented to several finite-element computer codes for analysis of structural components fabricated from polypropylene GMT. In this paper several example problems have been studied in order to determine the applicability of this modeling approach to predicting time-dependent deformations due to creep in GMT components. These example problems have been solved by utilizing two commercially available codes: ABAQUS, and ANSYS. Furthermore, results obtained with the codes have been compared to both analytic and experimental results, with varying degrees of success. The paper details these results for each of the example problems considered herein. © 2001 Elsevier Science Ltd. All rights reserved.
|
|
| 9. |
- Andersson, Henrik, et al.
(författare)
-
Ethics education to support ethical competence learning in healthcare : an integrative systematic review
- 2022
-
Ingår i: BMC Medical Ethics. - : BioMed Central. - 1472-6939. ; 23
-
Forskningsöversikt (refereegranskat)abstract
- Background: Ethical problems in everyday healthcare work emerge for many reasons and constitute threats to ethi- cal values. If these threats are not managed appropriately, there is a risk that the patient may be inflicted with moral harm or injury, while healthcare professionals are at risk of feeling moral distress. Therefore, it is essential to support the learning and development of ethical competencies among healthcare professionals and students. The aim of this study was to explore the available literature regarding ethics education that promotes ethical competence learning for healthcare professionals and students undergoing training in healthcare professions.Methods: In this integrative systematic review, literature was searched within the PubMed, CINAHL, and PsycInfo databases using the search terms ‘health personnel’, ‘students’, ‘ethics’, ‘moral’, ‘simulation’, and ‘teaching’. In total, 40 arti- cles were selected for review. These articles included professionals from various healthcare professions and students who trained in these professions as subjects. The articles described participation in various forms of ethics education. Data were extracted and synthesised using thematic analysis.Results: The review identified the need for support to make ethical competence learning possible, which in the long run was considered to promote the ability to manage ethical problems. Ethical competence learning was found to be helpful to healthcare professionals and students in drawing attention to ethical problems that they were not previ- ously aware of. Dealing with ethical problems is primarily about reasoning about what is right and in the patient’s best interests, along with making decisions about what needs to be done in a specific situation.Conclusions: The review identified different designs and course content for ethics education to support ethical competence learning. The findings could be used to develop healthcare professionals’ and students’ readiness and capabilities to recognise as well as to respond appropriately to ethically problematic work situations.
|
|
| 10. |
- Bennesved, Anna, et al.
(författare)
-
Ambulance clinicians’ understanding of older patients’ self-determination : A vignette study
- 2023
-
Ingår i: Nursing Ethics. - : Sage Publications. - 0969-7330 .- 1477-0989. ; , s. 1-13
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Older patients are often vulnerable and highly dependent on healthcare professionals’ assessment in the event of acute illness. In the context of ambulance services, this poses challenges as the assessment is normally conducted with a focus on identifying life-threatening conditions. Such assessment is not fully satisfactory in a patient relationship that also aims to promote and protect patient autonomy.Aim: To describe ambulance clinicians’ understanding of older patients’ self-determination when the pa- tient’s decision-making ability is impaired.Research design: A qualitative design with an inductive approach, guided by descriptive phenomenology.Participants: In total, 30 ambulance clinicians, comprised of 25 prehospital emergency nurses, 1 nurse and 4 emergency medical technicians participated in 15 dyadic interviews.Ethical considerations: The research was conducted in accordance with the Declaration of Helsinki, and permission was granted by the Swedish Ethical Review Authority.Findings: The findings are presented in two themes: (1) Movement between explicit and implicit will; and (2) Contradictions about the patient’s best interests. The clinicians’ interpretations are based on an understanding of the patient’s situation using substitute decision-making in emergency situations and conversations that reveal the patient’s explicit wishes. Sometimes the clinicians collaborate to validate the patient’s implicit will, while they at other times subordinate themselves to others’ opinions. The clinicians find themselves in conflict between personal values and organisational values as they try to protect the patient’s self-determination.Conclusion: The results indicate that older patients with an impaired decision-making ability risk losing the right to self-determination in the context of ambulance services. The clinicians face challenges that significantly affect their ability to handle the older patient’s unique needs based on a holistic perspective and their ability to be autonomous.
|
|
| 11. |
|
|
| 12. |
- Bill-Axelson, Anna, et al.
(författare)
-
Radical prostatectomy versus watchful waiting in localized prostate cancer : the Scandinavian prostate cancer group-4 randomized trial
- 2008
-
Ingår i: Journal of the National Cancer Institute. - : Oxford University Press. - 0027-8874 .- 1460-2105. ; 100:16, s. 1144-1154
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The benefit of radical prostatectomy in patients with early prostate cancer has been assessed in only one randomized trial. In 2005, we reported that radical prostatectomy improved prostate cancer survival compared with watchful waiting after a median of 8.2 years of follow-up. We now report results after 3 more years of follow-up.METHODS: From October 1, 1989, through February 28, 1999, 695 men with clinically localized prostate cancer were randomly assigned to radical prostatectomy (n = 347) or watchful waiting (n = 348). Follow-up was complete through December 31, 2006, with histopathologic review and blinded evaluation of causes of death. Relative risks (RRs) were estimated using the Cox proportional hazards model. Statistical tests were two-sided.RESULTS: During a median of 10.8 years of follow-up (range = 3 weeks to 17.2 years), 137 men in the surgery group and 156 in the watchful waiting group died (P = .09). For 47 of the 347 men (13.5%) who were randomly assigned to surgery and 68 of the 348 men (19.5%) who were not, death was due to prostate cancer. The difference in cumulative incidence of death due to prostate cancer remained stable after about 10 years of follow-up. At 12 years, 12.5% of the surgery group and 17.9% of the watchful waiting group had died of prostate cancer (difference = 5.4%, 95% confidence interval [CI] = 0.2 to 11.1%), for a relative risk of 0.65 (95% CI = 0.45 to 0.94; P = .03). The difference in cumulative incidence of distant metastases did not increase beyond 10 years of follow-up. At 12 years, 19.3% of men in the surgery group and 26% of men in the watchful waiting group had been diagnosed with distant metastases (difference = 6.7%, 95% CI = 0.2 to 13.2%), for a relative risk of 0.65 (95% CI = 0.47 to 0.88; P = .006). Among men who underwent radical prostatectomy, those with extracapsular tumor growth had 14 times the risk of prostate cancer death as those without it (RR = 14.2, 95% CI = 3.3 to 61.8; P < .001).CONCLUSION: Radical prostatectomy reduces prostate cancer mortality and risk of metastases with little or no further increase in benefit 10 or more years after surgery.
|
|
| 13. |
- Fager, Cecilia, et al.
(författare)
-
Nurses' use of an advisory decision support system in ambulance services : A qualitative study
- 2024
-
Ingår i: Journal of Advanced Nursing. - : John Wiley & Sons. - 0309-2402 .- 1365-2648.
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: To illuminate from the perspective of nurses in ambulance services the experiences of using a web-based advisory decision support system to assess care needs and refer patients.Design: Inductive and descriptive approaches.Method: Thirteen semi-structured interviews were conducted in the spring of 2020. The data were analysed through the reflexive thematic analysis.Results: The Swedish web-based advisory decision support system (ADSS) was found to strengthen nurses' feelings of security when they assess patients' care needs, promote their competence and professional pride, and help them manage stress. However, the system also generated difficulties for nurses to adjust to the dynamic ambulance team and revealed a discrepancy between their professional roles and responsibilities to refer patients and provide self-care advice. The nurses thought that the support system facilitated their increased participation and helped them understand patients and significant others by offering transparency in assessment and decision making. Thus, the support system provides nurses with an opportunity to strengthen patients' independence through information and education. However, in the care relationship, nurses worked to overcome patients' expectations.Conclusion: Nurses using the ADSS increased their security while performing assessments and referrals and found new opportunities to provide information and promote understanding of their decisions. However, nursing care values can be threatened when new support systems are introduced, especially as ambulance services become increasingly protocol-driven.Implications for Profession and/or Patient Care: These findings have implications for nurses' work environments and help them maintain consistency in making medical assessments and in providing equivalent self-care advice when referring patients to the different levels of care. The findings will also impact researchers and policymakers who formulate decision support systems.Reporting Method: Consolidated criteria for reporting qualitative research (COREQ).Patient or Public Contribution: None.
|
|
| 14. |
- Ghafouri, Bijar, et al.
(författare)
-
Biomarkers of lsystemic inflammation in farmers with musculoskeletal disorders : a plasma proteomic study
- 2016
-
Ingår i: BMC Musculoskeletal Disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 17
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Farmers have an increased risk for musculoskeletal disorders (MSD) such as osteoarthritis of the hip, low back pain, and neck and upper limb complaints. The underlying mechanisms are not fully understood. Workrelated exposures and inflammatory responses might be involved. Our objective was to identify plasma proteins that differentiated farmers with MSD from rural referents. Methods: Plasma samples from 13 farmers with MSD and rural referents were included in the investigation. Gel based proteomics was used for protein analysis and proteins that differed significantly between the groups were identified by mass spectrometry. Results: In total, 15 proteins differed significantly between the groups. The levels of leucine-rich alpha-2-glycoprotein, haptoglobin, complement factor B, serotransferrin, one isoform of kininogen, one isoform of alpha-1-antitrypsin, and two isoforms of hemopexin were higher in farmers with MSD than in referents. On the other hand, the levels of alpha-2-HS-glycoprotein, alpha-1B-glycoprotein, vitamin D-binding protein, apolipoprotein A1, antithrombin, one isoform of kininogen, and one isoform of alpha-1-antitrypsin were lower in farmers than in referents. Many of the identified proteins are known to be involved in inflammation. Conclusions: Farmers with MSD had altered plasma levels of protein biomarkers compared to the referents, indicating that farmers with MSD may be subject to a more systemic inflammation. It is possible that the identified differences of proteins may give clues to the biochemical changes occurring during the development and progression of MSD in farmers, and that one or several of these protein biomarkers might eventually be used to identify and prevent work-related MSD.
|
|
| 15. |
- Holmberg, Bodil, 1970-, et al.
(författare)
-
Self-determination in older patients: Experiences from nurse-dominated ambulance services
- 2024
-
Ingår i: Journal of Advanced Nursing. - : Wiley-Blackwell. - 0309-2402 .- 1365-2648. ; , s. 1-11
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: To describe ambulance clinicians' experiences of self-determination in older patients.Design: The study had an inductive and explorative design, guided from a life-world perspective.Methods: Thirty-two Swedish ambulance clinicians were interviewed in six focus groups in November 2019. The data were analysed with content analysis, developing manifest categories and latent themes.Findings: The ambulance clinicians assessed the older patients' exercise of self-determination by engaging in conversation and by being visually alert, to eventually gain an overall picture of their decision-making capacity. This assessment was used as a platform when informing older patients of their rights, thus promoting their participation in care. Having limited time and narrow guidelines counteracted ambulance clinicians' ambitions to support older patients' general desire to avoid hospitalization, which resulted in an urge to displace their responsibility to external decision-makers.Conclusion: Expectations that older patients with impaired decision-making ability will give homogeneous responses mean an increased risk of ageist attitudes with a simplified view of patient autonomy. Such attitudes risk the withholding of information about options that healthcare professionals do not wish older patients to choose. When decision-making is difficult, requests for expanded guidelines may paradoxically risk alienation from the professional nursing role.Implications and Impact: The findings show ambulance clinicians' unwillingness to shoulder their professional responsibility when encountering older patients with impaired decision-making ability. In assuming that all older patients reason in the same way, ambulance clinicians tend to adopt a simplistic and somewhat ageist approach when it comes to patient autonomy. This points to deficiencies in ethical competence, which is why increased ethics support is deemed suitable to promote and develop ethical competence. Such support can increase the ability to act as autonomous professionals in accordance with professional ethical codes.Reporting Method: This study adhered to COREQ guidelines.Patient and Public Contribution: None.
|
|
| 16. |
|
|
| 17. |
|
|
| 18. |
|
|
| 19. |
- Holmberg, Sara, 1967-
(författare)
-
Musculoskeletal Disorders among Farmers and Referents, with Special Reference to Occurence, Health Care Utilization and Etiological Factors : A Population-based Study
- 2004
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Objectives. To study the prevalence of musculoskeletal symptoms among farmers as compared to rural referents and to evaluate the effects of physical work exposures, psychosocial factors, lifestyle and comorbidity.Material and methods. A cross-sectional population-based survey of 1013 farmers and 769 matched referents was performed. Data on various symptoms, consultations and sick leave and information on primary health care and hospital admissions were obtained along with information on physical workload, psychosocial factors and lifestyle. Results. The farmers reported higher lifetime prevalence of symptoms from hands and forearms, low back and hips as compared to the referents. However, the farmers did not seek medical advice more often than the referents, and they reported significantly fewer sick leaves. After adjustment for the influence of physical work exposure, farmers still had a excess rate of low back pain (LBP) and hip symptoms as compared with the referents, while a lower rate of neck-shoulder symptoms was revealed. Several of the psychosocial variables were associated with LBP but the difference in LBP prevalence between farmers and referents could only be explained to some extent. LBP was associated with musculoskeletal symptoms other than LBP and with chest discomfort, dyspepsia, symptoms from mucous membranes, skin problems, work-related fever attacks, and primary care for digestive disorders. Presence of both respiratory and digestive disorders doubled the LBP prevalence.Conclusions. Symptoms from hips and low back were more frequent among farmers than among referents, but farmers did not seek more health care and reported fewer sick leaves than referents. Physical work exposure and psychosocial factors did not explain the differences in low back and hip symptoms between the two groups. Significant associations between LBP and digestive and respiratory disorders might indicate that these disorders may have etiological factors in common.
|
|
| 20. |
|
|
| 21. |
- Jacobsson, Amanda, et al.
(författare)
-
”Ambulanssjukvården behöver genomgripande förändringar”
- 2021
-
Ingår i: Dagens Medicin. - : Dagens Medicin. - 1402-1943. ; :2021-06-23
-
Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Debattörer från Ambulance health research network vill se en nationell ledningsstruktur, ökad evidens för vården, akademisk kompetens i ledningsfunktioner samt en nationell utbildnings- och kompetensstandard.
|
|
| 22. |
- Johansson, Carl-Johan, et al.
(författare)
-
Sågverksnytt nr 1
- 2013
-
Rapport (övrigt vetenskapligt/konstnärligt)
|
|
| 23. |
- Levine, Hagai, et al.
(författare)
-
Male reproductive health statement (XIIIth international symposium on Spermatology, may 9th-12th 2018, Stockholm, Sweden
- 2018
-
Ingår i: Basic and Clinical Andrology. - : Springer Science and Business Media LLC. - 2051-4190. ; 28:1
-
Tidskriftsartikel (refereegranskat)abstract
- On the occasion of the XIIIth International Symposium on Spermatology held from 9 to 13 May 2018 in Stockholm (Sweden), participants (guest speakers and audience) collectively felt the need to make a public statement on the general issue of male reproductive health. Our intention is to raise awareness of what we believe is a neglected area of research despite alarming situations around the world. The disclosure strategy desired by the co-authors is to bring it to the attention of the greatest number partly by considering co-publication in the various periodicals dealing with Reproductive Biology and Andrology. BaCA's editorial office accepted this mission and found it natural that our periodical, the official journal of the French Andrology Society (SALF), should carry this message.
|
|
| 24. |
- Micke, Patrick, et al.
(författare)
-
Gene Copy Number Aberrations Are Associated with Survival in Histologic Subgroups of Non-small Cell Lung Cancer
- 2011
-
Ingår i: Journal of Thoracic Oncology. - 1556-0864 .- 1556-1380. ; 6:11, s. 1833-1840
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: Non-small cell lung cancer (NSCLC) is characterized by a multitude of genetic aberrations with unknown clinical impact. In this study, we aimed to identify gene copy number changes that correlate with clinical outcome in NSCLC. To maximize the chance to identify clinically relevant events, we applied a strategy involving two prognostically extreme patient groups. Methods: Short-term (<20 month; n = 53) and long-term survivors (>58 month; n = 47) were selected from a clinically well-characterized NSCLC patient cohort with available fresh frozen tumor specimens. The samples were analyzed using high-resolution single-nucleotide polymorphism array technology to assess gene copy number variations and array-based gene expression profiling. The molecular data were combined with information on clinical parameters. Results: Genetic aberrations were strongly associated with tumor histology. In adenocarcinoma (n = 50), gene copy number gains on chromosome 8q21-q24.3 (177 genes) were more frequent in long-term than in short-term survivors. In squamous cell carcinoma (n = 28), gains on chromosome 14q23.1-24.3 (133 genes) were associated with shorter survival, whereas losses in a neighboring region, 14q31.1-32.33 (110 genes), correlated with favorable outcome. In accordance with copy number gains and losses, messenger RNA expression levels of corresponding genes were increased or decreased, respectively. Conclusion: Comprehensive tumor profiling permits the integration of genomic, histologic, and clinical data. We identified gene copy number gains and losses, with corresponding changes in messenger RNA levels that were associated with prognosis in adenocarcinoma and squamous cell carcinoma of the lung.
|
|
| 25. |
- Mortensen, Anders, et al.
(författare)
-
Stevensons utmarker
- 2008
-
Ingår i: Theorier om verklig diktning. Festskrift till Per Erik Ljung.
-
Bokkapitel (populärvet., debatt m.m.)abstract
- En artikel om Robert Louis Stevenson och i synnerhet Dr Jekyll and Mr hyde
|
|
| 26. |
- Nilsson, Magnus, et al.
(författare)
-
Characterization of Selective and Potent JAK1 Inhibitors Intended for the Inhaled Treatment of Asthma
- 2022
-
Ingår i: Drug Design, Development and Therapy. - : Informa Healthcare. - 1177-8881. ; 16, s. 2901-2917
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: Janus kinase 1 (JAK1) is implicated in multiple inflammatory pathways that are critical for the pathogenesis of asthma, including the interleukin (IL)-4, IL-5, IL-13, and thymic stromal lymphopoietin cytokine signaling pathways, which have previously been targeted to treat allergic asthma. Here, we describe the development of AZD0449 and AZD4604, two novel and highly selective JAK1 inhibitors with promising properties for inhalation.Methods: The effects of AZD0449 and AZD4604 in JAK1 signaling pathways were assessed by measuring phosphorylation of signal transducer and activator of transcription (STAT) proteins and chemokine release using immunoassays of whole blood from healthy human volunteers and rats. Pharmacokinetic studies performed on rats evaluated AZD0449 at a lung deposited dose of 52 mu g/kg and AZD4604 at 30 mu g/kg. The efficacy of AZD0449 and AZD4604 was assessed by evaluating lung inflammation (cell count and cytokine levels) and the late asthmatic response (average enhanced pause [Penh]).Results: Both compounds inhibited JAK1-dependent cytokine signaling pathways in a dose-dependent manner in human and rat leukocytes. After intratracheal administration in rats, both compounds exhibited low systemic exposures and medium-to-long terminal lung half-lives (AZD0449, 34 hours; AZD4604, 5 hours). Both compounds inhibited STAT3 and STAT5 phosphorylation in lung tissue from ovalbumin (OVA)-challenged rats. AZD0449 and AZD4604 also inhibited eosinophilia in the lung and reduced the late asthmatic response, measured as Penh in the OVA rat model.Conclusion: AZD0449 and AZD4604 show potential as inhibitors of signaling pathways involved in asthmatic immune responses, with target engagement demonstrated locally in the lung. These findings support the clinical development of AZD0449 and AZD4604 for the treatment of patients with asthma.
|
|
| 27. |
- Schmidt, Marcus, et al.
(författare)
-
A comprehensive analysis of human gene expression profiles identifies stromal immunoglobulin kappa C as a compatible prognostic marker in human solid tumors
- 2012
-
Ingår i: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 18:9, s. 2695-2703
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE:Although the central role of the immune system for tumor prognosis is generally accepted a single robust marker is not yet available.EXPERIMENTAL DESIGN:Based on ROC (receiver operating characteristic) analyses robust markers were identified from a 60 gene B-cell derived metagene and analyzed in gene expression profiles of 1810 breast cancer, 1056 non-small cell lung cancer, 513 colorectal and 426 ovarian cancer patients. Protein and RNA levels were examined in paraffin embedded tissue of 330 breast cancer patients. The cell types were identified using immunohistochemical co-staining and confocal fluorescence microscopy.RESULTS:We identified immunoglobulin kappa C (IGKC) which as a single marker is similarly predictive and prognostic as the entire B-cell metagene. IGKC was consistently associated with metastasis free survival across different molecular subtypes in node-negative breast cancer (n=965) and predicted response to anthracycline-based neoadjuvant chemotherapy (n=845) [P less than 0.001]. In addition, IGKC gene expression was prognostic in non-small cell lung cancer and colorectal cancer. No association was observed in ovarian cancer. IGKC protein expression was significantly associated with survival in paraffin embedded tissues of 330 breast cancer patients. Tumor infiltrating plasma cells were identified as the source of IGKC expressionCONCLUSION:Our findings provide IGKC as a novel diagnostic marker for risk stratification in human cancer and support concepts to exploit the humoral immune response for anti-cancer therapy. It could be validated in several independent cohorts and performed similarly well in RNA from fresh frozen as well as from paraffin tissue and on protein level by immunostaining.
|
|
| 28. |
- Svensson, Anders, 1977-, et al.
(författare)
-
Ambulance clinicians' attitudes to older patients' self-determination when the patient has impaired decision-making ability : a Delphi study
- 2022
-
Ingår i: International Journal of Older People Nursing. - : Wiley-Blackwell Publishing Inc.. - 1748-3735 .- 1748-3743. ; 17:2
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: The proportion of older people is increasing and reflects in the demand on ambulance services (AS). Patients can be more vulnerable and increasingly dependent, especially when their decision-making ability is impaired. Self-determination in older people has a positive relation to quality of life and can raise ethical conflicts in AS. Hence, the aim of this study was to empirically explore attitudes among Swedish ambulance clinicians (ACs) regarding older patients ’self-determination in cases where patients have impaired decision-making ability, and who are in urgent need of care.Materials and methods: An explorative design was adopted. A Delphi technique was used, comprising four rounds, involving a group (N = 31) of prehospital emergency nurses (n = 14), registered nurses (n = 10) and emergency medical technicians (n = 7). Focus group conversations (Round 1) and questionnaires (Rounds 2–4) generated data. Round 1 was analyzed using manifest content analysis, which ultimately resulted in the creation of discrete items. Each item was rated with a five-point Likert scale together with free-text answers. Consensus (≥70%) was calculated by trichotomising the Likert scale.Results: Round 1 identified 108 items which were divided into four categories: (1) at- titudes regarding the patient (n = 35), (2) attitudes regarding the patient relationship (n = 8), (3) attitudes regarding oneself and one's colleagues (n = 45), and (4) attitudes regarding other involved factors (n = 20). In Rounds 2–4, one item was identified in the free text from Round 2, generating a total of 109 items. After four rounds, 72 items (62%) reached consensus.Conclusions: The findings highlight the complexity of ACs 'attitudes towards older patients' self-determination. The respect of older patients' self-determination is challenged by the patient, other healthcare personnel, significant others and / or colleagues. The study provided a unique opportunity to explore self-determination and shared decision-making. AS have to provide continued ethical training, for ex- ample to increase the use of simulation-based training or moral case deliberations in order to strengthen the ACs ’moral abilities within their professional practice.Implications for practice: Ambulance services must develop opportunities to pro- vide continued training within this topic. One option would be to increase the use of simulation-based training, focusing on ethical aspects of care. Another option might be to facilitate moral case deliberations to strengthen the ACs' abilities to manage these issues while being able to share experiences with peers. These types of interventions should illuminate the importance of the topic for the individual AC, which, in turn, may strengthen and develop the caring abilities within an integrated care team.
|
|
| 29. |
- Vaziri-Sani, Fariba, et al.
(författare)
-
Phenotypic expression of factor H mutations in patients with atypical hemolytic uremic syndrome
- 2006
-
Ingår i: Kidney International. - : Nature Publishing Group. - 0085-2538 .- 1523-1755. ; 69:6, s. 981-988
-
Tidskriftsartikel (refereegranskat)abstract
- We investigated the phenotypic expression of factor H mutations in two patients with atypical hemolytic uremic syndrome (HUS). Factor H in serum was assayed by rocket immunoelectrophoresis, immunoblotting, and double immunodiffusion and in tissue by immunohistochemistry. Functional activity was analyzed by hemolysis of sheep erythrocytes and binding to endothelial cells. A homozygous mutation in complement control protein (CCP) domain 10 of factor H was identified in an adult man who first developed membranoproliferative glomerulonephritis and later HUS. C3 levels were very low. The patient had undetectable factor H levels in serum and a weak factor H 150 kDa band. Double immunodiffusion showed partial antigenic identity with factor H in normal serum owing to the presence of factor H-like protein 1. Strong specific labeling for factor H was detected in glomerular endothelium, mesangium and in glomerular and tubular epithelium as well as in bone marrow cells. A heterozygous mutation in CCP 20 of factor H was found in a girl with HUS. C3 levels were moderately decreased at onset. Factor H levels were normal and a normal 150 kDa band was present. Double immunodiffusion showed antigenic identity with normal factor H. Factor H labeling was minimal in the renal cortex. Factor H dysfunction was demonstrated by increased sheep erythrocyte hemolysis and decreased binding to endothelial cells. In summary, two different factor H mutations associated with HUS were examined: in one, factor H accumulated in cells, and in the other, membrane binding was reduced.
|
|
| 30. |
- Wikander, Kjell, et al.
(författare)
-
Alternative catalysts and carbon support material for PEMFC
- 2006
-
Ingår i: Fuel Cells. - : Wiley. - 1615-6846 .- 1615-6854. ; 6:1, s. 21-25
-
Tidskriftsartikel (refereegranskat)abstract
- In order to investigate the possibility of increasing the reactivity for oxygen reduction reaction (ORR) of the cathode in a PEMFC a series of Pt/C catalysts was prepared using water-in-oil microemulsions for synthesizing Pt nanoparticles. The Pt nanoparticles were deposited on porous carbon support (Vulcan XC-72 or a mesoporous carbon) and the catalysts were processed into MEAs. The MEA samples were evaluated and compared with a commercial sample and with Pt/C catalyst samples prepared using a conventional direct impregnation method. The mesoporous carbon support investigated as a potential alternative to Vulcan XC72 has a very high specific surface area and a narrow pore size distribution. The materials were characterized with XRD, TEM, SEM-EDX, N-2 sorption and steady state polarization. It was found that it is possible to increase the ORR reactivity using the microemulsion route for formation of Pt nanoparticles. It was concluded that the MEA processing conditions for the mesoporous carbon support have to be modified to reach improved ORR reactivity, likely due to the large differences in specific surface area, porosity and conductivity compared to the Vulcan carbon.
|
|
| 31. |
|
|
| 32. |
- Agaton, Charlotta, et al.
(författare)
-
Gene expression analysis by signature pyrosequencing
- 2002
-
Ingår i: Gene. - 0378-1119 .- 1879-0038. ; 289:1-2, s. 31-39
-
Tidskriftsartikel (refereegranskat)abstract
- We describe a novel method for transcript profiling based on high-throughput parallel sequencing of signature tags using a non-gel-based microtiter plate format. The method relies on the identification of cDNA clones by pyrosequencing of the region corresponding to the 3'-end of the mRNA preceding the poly(A) tail. Simultaneously, the method can be used for gene discovery, since tags corresponding to unknown genes can be further characterized by extended sequencing. The protocol was validated using a model system for human atherosclerosis. Two 3'-tagged cDNA libraries, representing macrophages and foam cells, which are key components in the development of atherosclerotic plaques, were constructed using a solid phase approach. The libraries were analyzed by pyrosequencing, giving on average 25 bases. As a control, conventional expressed sequence tag (EST) sequencing using slab gel electrophoresis was performed. Homology searches were used to identify the genes corresponding to each tag. Comparisons with EST sequencing showed identical, unique matches in the majority of cases when the pyrosignature was at least 18 bases. A visualization tool was developed to facilitate differential analysis using a virtual chip format. The analysis resulted in identification of genes with possible relevance for development of atherosclerosis. The use of the method for automated massive parallel signature sequencing is discussed.
|
|
| 33. |
|
|
| 34. |
|
|
| 35. |
|
|
| 36. |
- Ahlford, Marianne, et al.
(författare)
-
Uppsala Underdogs - A Robot Soccer Project
- 2006
-
Rapport (populärvet., debatt m.m.)abstract
- In this paper, we describe the four-legged soccer team Uppsala Underdogs developed by a group of 4th year computer science students at Uppsala University during the fall of 2004. The project is based on the experience from two similar previous projects. This year the emphasis of the project has been on distribution of data and on support for evaluation and reconfiguration of strategies. To support data distribution, a middleware has been developed, which implements a replication algorithm and provides a clean interface for the other software modules (or behaviors). To enable easy reconfiguration of strategies, an automata-based graphical description language has been developed, which can be compiled into code that uses the database and the lower level modules, such as tactics and positioning, to make decisions and control the robot. In addition, a graphical simulator has been developed in which the strategies can be evaluated.
|
|
| 37. |
- Ahlm, Clas, 1956-, et al.
(författare)
-
Prevalence of antibodies specific to Puumala virus among farmers in Sweden
- 1998
-
Ingår i: Scandinavian Journal of Work, Environment and Health. - : Scandinavian Journal of Work, Environment and Health. - 0355-3140 .- 1795-990X. ; 24:2, s. 104-108
-
Tidskriftsartikel (refereegranskat)abstract
- Serological evidence confirmed that the exposure of humans to Puumala virus is firmly restricted to the northern and central parts of Sweden. In addition the evidence indicated that, in this region, farming is associated with an increased risk of contracting hantavirus infection.
|
|
| 38. |
|
|
| 39. |
|
|
| 40. |
- Ajaxon, Ingrid, et al.
(författare)
-
Fatigue performance of a high-strength, degradable calcium phosphate bone cement
- 2018
-
Ingår i: Journal of The Mechanical Behavior of Biomedical Materials. - : ELSEVIER SCIENCE BV. - 1751-6161 .- 1878-0180. ; 79, s. 46-52
-
Tidskriftsartikel (refereegranskat)abstract
- Calcium phosphate cements (CPCs) are clinically used as injectable materials to fill bone voids and to improve hardware fixation in fracture surgery. In vivo they are dynamically loaded; nonetheless little is known about their fatigue properties. The aim of this study was to, for the first time, investigate the fatigue performance of a high strength, degradable (brushitic) CPC, and also evaluate the effect of cement porosity (by varying the liquid to powder ratio, L/P) and the environment (air at room temperature or in a phosphate buffered saline solution, PBS, at 37 degrees C) on the fatigue life. At a maximum compressive stress level of 15 MPa, the cements prepared with an L/P-ratio of 0.22 and 0.28 ml/g, corresponding to porosities of approximately 12% and 20%, had a 100% probability of survival until run-out of 5 million cycles, in air. When the maximum stress level, or the L/P-ratio, was increased, the probability of survival decreased. Testing in PBS at 37 degrees C led to more rapid failure of the specimens. However, the high-strength cement had a 100% probability of survival up to approximately 2.5 million cycles at a maximum compressive stress level of 10 MPa in PBS, which is substantially higher than some in vivo stress levels, e.g., those found in the spine. At 5 MPa in PBS, all specimens survived to run-out. The results found herein are important if clinical use of the material is to increase, as characterisation of the fatigue performance of CPCs is largely lacking from the literature.
|
|
| 41. |
|
|
| 42. |
|
|
| 43. |
|
|
| 44. |
- Andersson, David, 1979, et al.
(författare)
-
DN Debatt: LRF och Svenskt flyg svarar inte om klimatmålen
- 2015
-
Ingår i: Dagens Nyheter. - 1101-2447.
-
Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Sammantaget ser vi inget i motdebattörernas argument som talar emot att införa styrmedel, till exempel konsumtionsskatter, inom dessa områden där inga stora tekniska lösningar finns i sikte, skriver 14 miljö- och energiforskare i slutrepliken till sin text om flyg- och köttskatt (26/2).
|
|
| 45. |
- Andersson, David, 1979, et al.
(författare)
-
Nu krävs kraftfulla åtgärder mot nötkött och flygresor
- 2015
-
Ingår i: Dagens Nyheter. - 1101-2447. ; 2015-02-27
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Svenskarnas globala utsläpp från köttkonsumtion och flygresor motsvarar hälften av de totala utsläppen på hemmaplan. I vår rapport till Naturvårdsverket föreslår vi tydliga styrmedel – som nya skatter – för att begränsa konsumtionen på dessa områden, skriver 14 miljö- och energiforskare.
|
|
| 46. |
- Andersson, Lars Gustaf, et al.
(författare)
-
Peter Weiss och minnesmaskinen: Motståndets estetik
- 2008
-
Ingår i: Theorier om verklig diktning. En festskrift till Per Erik Ljung. - 1102-5522. ; , s. 263-277
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Analysis of the novel Die Ästhetik des Widerstands by Swedish/German author Peter Weiss. The aim of the analysis is to trace the views of film art that the author presents in this novel. The conclusion is that Weiss expresses explicit views on film art and cinematography, but also that there are implicit patterns in the structure of the narrative that can be explained as a cinematic imagination.
|
|
| 47. |
- Andersson, Martin, 1974, et al.
(författare)
-
Use of Self-Assembled Surfactants for Nanomaterials Synthesis
- 2009
-
Ingår i: Particulate Systems in Nano- and Biotechnologies. ; , s. 27-51
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Synthesis of inorganic materials with nanosized dimensions can take advantage of the ability of surfactants to self-assemble into well-defined structures. These structures are used as a kind of template for the synthesis. This approach of nanomaterials preparation has triggered substantial interest both in the surface chemistry and the materials chemistry community. The accuracy and reproducibility of the self-assembly process has been seen as means of achieving control of materials architecture on the nanometer scale. This is a biomimetic approach; a wide variety of biological structural materials are made by a templating process with the use of surface active compounds—primarily surface active polymers but also low molecular weight polar lipids. The number of papers dealing with surfactant-templated synthesis of inorganic materials has increased dramatically in recent years and several review papers deal with various aspects of the technique (1-12). Existing and potential applications for the synthesized materials range from biomaterials (e.g., artificial bone), to technical products such as catalysts, magnetic particles, and pigments.
|
|
| 48. |
- Andreassen, Björn, 1975-, et al.
(författare)
-
Development of an efficient scanning and purging magnet system for IMRT with narrow high energy photon beams
- 2009
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 612:1, s. 201-208
-
Tidskriftsartikel (refereegranskat)abstract
- Due to the clinical advantages of Intensity Modulated Radiation Therapy (IMRT) high flexibility and accuracy in intensity modulated dose delivery is desirable to really maximize treatment outcome. Although it is possible to deliver IMRT by using broad beams in combination with dynamic multileaf collimation the process is rather time consuming and inefficient. By using narrow scanned high energy photon beams the treatment outcome can be improved, the treatment time reduced and accurate 3D in vivo dose delivery monitoring is possible by PET-CT based dose delivery imaging of photo nuclear reactions in human tissues. Narrow photon beams can be produced by directing a low emittance high energy electron beam on a thin target, and then cleaning the therapeutic photon beam from transmitted high energy electrons, and photon generated charged leptons, with a dedicated purging magnet placed directly downstream of the target. To have an effective scanning and purging magnet system the purging magnet should be placed immediately after the bremsstrahlung target to deflect the transmitted electrons to an efficient electron stopper. In the static electron stopper the electrons should be safely collected independent of the desired direction of the therapeutic scanned photon beam. The SID (Source to Isocentre Distance) should preferably be short while retaining the ability to scan over a large area on the patient and consequently there are severe requirements both on the strength and the geometry of the scanning and purging magnets. In the present study an efficient magnet configuration with a purging and scanning magnet assembly is developed for electron energies in the 50-75 MeV range and a SID of 75 cm. For a bremsstrahlung target of 3mm Be these electron energies produce a photon beam of 25-17 mm FWHM (Full Width Half Maximum) at a SID of 75 cm. The magnet system was examined both in terms of the efficiency in scanning the narrow bremsstrahlung beam and the deflection of transmitted and photon generated electrons. The simulations show that its is possible to have a scan area on the patient of up to 43 x 40 cm2 for an incident electron energy of 50 MeV and 28 x 40 cm2 at 75 MeV, while at the same time adequately deflecting the transmitted electron beam.
|
|
| 49. |
- Andreassen, Björn, et al.
(författare)
-
Fast IMRT with narrow high energy scanned photon beams
- 2011
-
Ingår i: Medical physics (Lancaster). - : Wiley. - 0094-2405. ; 38:8, s. 4774-4784
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: Since the first publications on intensity modulated radiation therapy (IMRT) in the early 1980s almost all efforts have been focused on fairly time consuming dynamic or segmental multileaf collimation. With narrow fast scanned photon beams, the flexibility and accuracy in beam shaping increases, not least in combination with fast penumbra trimming multileaf collimators. Previously, experiments have been performed with full range targets, generating a broad bremsstrahlung beam, in combination with multileaf collimators or material compensators. In the present publication, the first measurements with fast narrow high energy (50 MV) scanned photon beams are presented indicating an interesting performance increase even though some of the hardware used were suboptimal. Methods: Inverse therapy planning was used to calculate optimal scanning patterns to generate dose distributions with interesting properties for fast IMRT. To fully utilize the dose distributional advantages with scanned beams, it is necessary to use narrow high energy beams from a thin bremsstrahlung target and a powerful purging magnet capable of deflecting the transmitted electron beam away from the generated photons onto a dedicated electron collector. During the present measurements the scanning system, purging magnet, and electron collimator in the treatment head of the MM50 racetrack accelerator was used with 3-6 mm thick bremsstrahlung targets of beryllium. The dose distributions were measured with diodes in water and with EDR2 film in PMMA. Monte Carlo simulations with GEANT4 were used to study the influence of the electrons transmitted through the target on the photon pencil beam kernel. Results: The full width at half-maximum (FWHM) of the scanned photon beam was 34 mm measured at isocenter, below 9.5 cm of water, 1 m from the 3 mm Be bremsstrahlung target. To generate a homogeneous dose distribution in a 10 x 10 cm(2) field, the authors used a spot matrix of 100 equal intensity beam spots resulting in a uniformity of collimated 80%-20% penumbra of 9 mm at a primary electron energy of 50 MeV. For the more complex cardioid shaped dose distribution, they used 270 spots, which at a pulse repetition frequency of 200 Hz is completed every 1.36 s. Conclusions: The present measurements indicate that the use of narrow scanned photon beams is a flexible and fast method to deliver advanced intensity modulated beams. Fast scanned photon IMRT should, therefore, be a very interesting modality in the delivery of biologically optimized radiation therapy with the possibility for in vivo treatment verification with PET-CT imaging.
|
|
| 50. |
|
|
