| 1. |
- Andersson, Henrik, 1968-, et al.
(författare)
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Acute coronary syndrome in relation to the occurrence of associated symptoms : A quantitative study in prehospital emergency care.
- 2017
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Ingår i: International Emergency Nursing. - : Elsevier BV. - 1755-599X .- 1878-013X. ; 33, s. 43-47
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Acute chest pain is a common symptom among prehospital emergency care patients. Therefore, it is crucial that ambulance nurses (ANs) have the ability to identify symptoms and assess patients suffering from acute coronary syndrome (ACS). The aim of this study is to explore the occurrence of dyspnoea and nausea and/or vomiting in the prehospital phase of a suspected ACS and the associations with patients' outcome.METHODS: This study has a quantitative design based on data from hospital records and from a previous interventional study (randomised controlled trial) including five Emergency Medical Service (EMS) systems in western Sweden in the years 2008-2010.RESULTS: In all, 1836 patients were included in the interventional study. Dyspnoea was reported in 38% and nausea and/or vomiting in 26% of patients. The risk of death within one year increased with the presence of dyspnoea. The presence of nausea and/or vomiting increased the likelihood of a final diagnosis of acute myocardial infarction (AMI).CONCLUSION: This study shows that dyspnoea, nausea and/or vomiting increase the risk of death and serious diagnosis among ACS patients. This means that dyspnoea, nausea and/or vomiting should influence the ANs' assessment and that special education in cardiovascular nursing is required.
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| 2. |
- Billsten, Johan, 1971-, et al.
(författare)
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Organizational Readiness for Change (ORC) test used in the implementation of assessment instruments and treatment methods in a Swedish National study
- 2018
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Ingår i: Journal of Substance Abuse Treatment. - Amsterdam : Elsevier. - 0740-5472 .- 1873-6483. ; 84, s. 9-16
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Tidskriftsartikel (refereegranskat)abstract
- Organizational climate and related factors are associated with outcome and are as such of vital interest for healthcare organizations. Organizational Readiness for Change (ORC) is the questionnaire used in the present study to assess the influence of organizational factors on implementation success. The respondents were employed in one of 203 Swedish municipalities within social work and psychiatric substance/abuse treatment services. They took part in a nationwide implementation project organized by the Swedish Association of Local Authorities and Regions (SALAR), commissioned by the Swedish National Board of Health and Welfare. Aim The aims were: (a) to identify classes (clusters) of employees with different ORC profiles on the basis of data collected in 2011 and (b) to investigate ORC profiles which predicted the use of assessment instruments, therapy methods and collaborative activities in 2011 and 2013. Design and recruitment The evaluation study applied a naturalistic design with registration of outcome at consecutive assessments. The participants were contacted via official e-mail addresses in their respective healthcare units and were encouraged by their officials to participate on a voluntary basis. Statistics Descriptive statistics were obtained using SPSS version 23. A latent profile analysis (LPA) using Mplus 7.3 was performed with a robust maximum likelihood estimator (MLR) to identify subgroups (clusters) based on the 18 ORC indexes. Results A total of 2402 employees responded to the survey, of whom 1794 (74.7%) completed the ORC scores. Descriptive analysis indicated that the respondents were a homogenous group of employees, where women (72.0%) formed the majority. Cronbach's alpha for the 18 ORC indexes ranged from α = 0.67 to α = 0.78. A principal component analysis yielded a four-factor solution explaining 62% of the variance in total ORC scores. The factors were: motivational readiness (α = 0.64), institutional resources (α = 0.52), staff attributes (α = 0.76), and organizational climate (α = 0.74). An LPA analysis of the four factors with their three distinct profiles provided the best data fit: Profile 3 (n = 614), Profile 2 (n = 934), and Profile 1 (n = 246). Respondents with the most favorable ORC scores (Profile 3) used significantly more instruments and more treatment methods and had a better collaborating network in 2011 as well as in 2013 compared to members in Profile 1, the least successful profile. Conclusion In a large sample of social work and healthcare professionals, ORC scores reflecting higher institutional resources, staff attributes and organizational climate and lower motivational readiness for change were associated with a successful implementation of good practice guidelines for the care and treatment of substance users in Sweden. Low motivational readiness as a construct may indicate satisfaction with the present situation. As ORC proved to be an indicator of successful dissemination of evidence-based guidelines into routine and specialist healthcare, it can be used to tailor interventions to individual employees or services and to improve the dissemination of and compliance with guidelines for the treatment of substance users. © 2017
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| 3. |
- Bratt, Ola, 1963, et al.
(författare)
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The Value of an Extensive Transrectal Repeat Biopsy with Anterior Sampling in Men on Active Surveillance for Low-risk Prostate Cancer: A Comparison from the Randomised Study of Active Monitoring in Sweden (SAMS)
- 2019
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Ingår i: European Urology. - : Elsevier BV. - 0302-2838 .- 1873-7560. ; 76:4, s. 461-466
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Tidskriftsartikel (refereegranskat)abstract
- Background: A systematic repeat biopsy is recommended for men starting on active surveillance for prostate cancer, but the optimal number and distribution of cores are unknown. Objective: To evaluate an extensive repeat transrectal biopsy with anterior sampling in men starting on active surveillance. Design, setting, and participants: Randomised multicentre trial. From 2012 to 2016, 340 Swedish men, aged 40-75 yr, with recently diagnosed low-volume Gleason grade group 1 prostate cancer were included. Intervention: Either an extensive transrectal biopsy with anterior sampling (median 19 cores) or a standard transrectal biopsy (median 12 cores). Outcome measurements and statistical analysis: Primary outcome measure: Gleason grade group >= 2 cancer. Secondary outcomes: Cancer in anteriorly directed biopsy cores and postbiopsy infection. Nonparametric statistical tests were applied. Results and limitations: Gleason grade group >= 2 cancer was detected in 16% of 156 men who had an extensive biopsy and in 10% of 164 men who had a standard biopsy, a 5.7% difference (95% confidence interval [CI]-0.2% to 13%, p = 0.09). There was a strong linear association between prostate-specific antigen (PSA) density and cancer in the anteriorly directed biopsy cores. The odds ratios for cancer in the anteriorly directed cores were for any cancer 2.2 (95% CI 1.3-3.9, p = 0.004) and for Gleason grade group >= 2 cancer 2.3 (95% CI 1.2-4.4, p = 0.015) per 0.1-ng/ml/cm(3) increments. Postbiopsy infections were equally common in the two groups. A limitation is that magnetic resonance imaging was not used. Conclusions: The trial did not support general use of the extensive transrectal repeat biopsy template, but cancer in the anteriorly directed cores was common, particularly in men with high PSA density. The higher the PSA density, the stronger the reason to include anterior sampling at a systematic repeat biopsy. Patient summary: This trial compared two different templates for transrectal prostate biopsy in men starting on active surveillance for low-risk prostate cancer. Cancer was often found in the front part of the prostate, which is not sampled on a standard prostate biopsy. (C) 2019 European Association of Urology. Published by Elsevier B.V. All rights reserved.
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| 4. |
- Dellgren, Göran, 1961, et al.
(författare)
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Continuous improvement in outcome after heart transplantation - Long-term follow-up after three decades of experience.
- 2017
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Ingår i: International journal of cardiology. - : Elsevier BV. - 1874-1754 .- 0167-5273. ; 231, s. 188-194
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Forskningsöversikt (refereegranskat)abstract
- Heart transplantation (HTx) has become the standard treatment for patients with end-stage heart disease. We report on the long-term outcome after HTx at our centre and investigate trends in outcome over time.During the period, between 1984 and 2014, a total of 610 HTx procedures were performed in 595 patients (median 48years; IQR 31-57years; range 24days-71years; mean 43years; 75% male) in our institution. Long-term outcome was investigated in the whole cohort, among children (n=76), bridged with mechanical circulatory support (MCS, n=131), re-transplanted (n=17), and concomitant kidney transplantation (n=12).Long-term survival was at 1, 5, 10, 15 and 20years: 86% (95CI 0.83-0.89); 77% (95CI 0.73-0.80); 63% (95CI 0.59-0.68); 48% (95CI 0.43-0.54) and 30% (95CI 0.25-0.36), respectively. The median survival for the whole cohort was 14.1years. Patients transplanted during the most recent time period (2010-2014) had a better survival compared to previous eras, with a 1- and 3-year survival of 94% (95CI 0.89-0.97) and 93% (95CI 0.88-0.96), respectively (p<0.001). However, when survival was analysed for long-term MCS (n=80) versus short term MCS (n=35), there was a significantly poorer survival for the short-term MCS group (p=0.001). Independent predictors of long-term mortality included recipient age (p=0.041); previous smoking (p=0.034); ischemic heart disease (p=0.002); and preoperative ventilator therapy (p=0.004).We have shown that continuous improvement in outcome after HTx still occurs. In the last time era, direct transplantation from short-term MCS was abandoned, which may have inflicted outcome during the last time era.
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| 5. |
- Du, Lin, et al.
(författare)
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Sound amplification at a rectangular T-junction with merging mean flows
- 2016
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Ingår i: Journal of Sound and Vibration. - : Academic Press. - 0022-460X .- 1095-8568. ; 367, s. 69-83
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports a numerical study on the aeroacoustic response of a rectangular T-junction with merging mean flows. The primary motivation of the work is to explain the high sound amplification, recently seen experimentally, when introducing a small merging bias flow. The acoustic results are found solving the compressible Linearized Navier-Stokes Equations (LNSEs) in the frequency domain, where the base flow is first obtained using RANS with a k-epsilon turbulence model. The model predicts the measured scattering data well, including the amplitude and Strouhal number for the peak amplification, if the effect of eddy viscosity damping is included. It is found that the base flow changes significantly with the presence of a small bias flow. Compared to pure grazing flow a strong unstable shear layer is created in the downstream main duct starting from the T-junction trailing edge. This means that the main region of vortex-sound interaction is moved away from the junction to a downstream region much larger than the junction width. To analyze the sound amplification in this region Howe's energy corollary and the growth of acoustic density are used.
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| 6. |
- Dueking, Peter, et al.
(författare)
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Comparison of Non-Invasive Individual Monitoring of the Training and Health of Athletes with Commercially Available Wearable Technologies
- 2016
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Ingår i: Frontiers in Physiology. - : Frontiers Media SA. - 1664-042X. ; 7
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Forskningsöversikt (refereegranskat)abstract
- Athletes adapt their training daily to optimize performance, as well as avoid fatigue, overtraining and other undesirable effects on their health. To optimize training load, each athlete must take his/her own personal objective and subjective characteristics into consideration and an increasing number of wearable technologies (wearables) provide convenient monitoring of various parameters. Accordingly, it is important to help athletes decide which parameters are of primary interest and which wearables can monitor these parameters most effectively. Here, we discuss the wearable technologies available for non-invasive monitoring of various parameters concerning an athlete's training and health. On the basis of these considerations, we suggest directions for future development. Furthermore, we propose that a combination of several wearables is most effective for accessing all relevant parameters, disturbing the athlete as little as possible, and optimizing performance and promoting health.
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| 7. |
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Funktionell textanalys
- 2019. - 2
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Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- Den systemisk-funktionella grammatiken (SFG) har på senare år blivit alltmer populär i Sverige. Skrivdidaktiker och textforskare tilltalas av modellen och använder de grammatiska kategorierna i analyser och undervisning. Kanske kan detta förklaras av den starka förankringen i kontexten - SFG fungerar helt enkelt bra för att beskriva språk i sammanhang, liksom för att analysera hur språket är med och skapar sammanhang. Analysen är dock inte alltid enkel, utan kräver att man vänder och vrider på perspektiven. En bra hjälp är förstås att titta på andras analyser. Den möjligheten erbjuder denna bok.Bokens tre redaktörer har samlat sina erfarenheter av grammatisk analys av texter, och inleder bokens olika avdelningar med kapitel som tar upp dels grunderna i analysen, dels tänkbara problem och överväganden.I kapitlen analyseras många olika slags texter, till exempel reklam, platsannonser, elevinsändare, vigselordningar och styrdokument för skolan. Författarnas ambition är att ge en god inblick i hur den systemisk-funktionella grammatiken kan användas för att analysera texter. Funktionell textanalys ges numera ut av Studentlitteratur AB. Denna andra upplaga innehåller dock inga förändringar av innehållet jämfört med den första upplagan.
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| 8. |
- Hallqvist, Andreas, 1973, et al.
(författare)
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Dose escalation to 84 Gy with concurrent chemotherapy in stage III NSCLC appears excessively toxic: Results from a prematurely terminated randomized phase II trial
- 2018
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Ingår i: Lung Cancer. - : Elsevier BV. - 0169-5002 .- 1872-8332. ; 122, s. 180-186
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Concurrent chemoradiotherapy is the mainstay treatment for NSCLC stage III disease. To investigate whether radiation dose escalation based on individual normal tissue constraints can improve outcome, the Swedish lung cancer study group launched this randomized phase II trial. Materials and Methods: NSCLC patients with stage III disease, good performance status (0-1) and adequate lung function (FEV1 > 1.0 L and CO diffusion capacity > 40%) received three cycles of cisplatin (75 mg/m(2) day 1) and vinorelbine (25 mg/m(2) day 1 and 8) every third week. Radiotherapy started concurrently with the second cycle, with either 2 Gy daily, 5 days a week, to 68 Gy (A) or escalated therapy (B) based on constraints to the spinal cord, esophagus and lungs up to 84 Gy by adding an extra fraction of 2 Gy per week. Results: A pre-planned safety analysis revealed excessive toxicity and decreased survival in the escalated arm, and the study was stopped. Thirty-six patients were included during 2011-2013 (56% male, 78% with adenocarcinoma, 64% with PS 0 and 53% with stage IIIB). The median progression-free survival (PFS) and overall survival (OS) were 11 and 17 months in arm B compared to the encouraging results of 28 and 45 months in the standard arm. The 1- and 3-year survival rates were 56% and 33% (B) and 72% and 56% (A), respectively. There were seven toxicity-related deaths due to esophageal perforations and pneumonitis: five in the escalated group and two with standard treatment. Conclusion: Dose-escalated concurrent chemoradiotherapy to 84 Gy to primary tumor and nodal disease is hazardous, with a high risk of excessive toxicity, whereas modern standard dose chemoradiotherapy with proper staging given in the control arm shows a promising outcome with a median survival of 45 months and a 3-year survival of 56% (NCT01664663).
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| 9. |
- Holmberg, Andreas, et al.
(författare)
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A frequency domain linearized Navier-Stokes method including acoustic damping by eddy viscosity using RANS
- 2015
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Ingår i: Journal of Sound and Vibration. - : Elsevier BV. - 0022-460X .- 1095-8568. ; 346, s. 229-247
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a method for including damping of acoustic energy in regions of strong turbulence is derived for a linearized Navier-Stokes method in the frequency domain. The proposed method is validated and analyzed in 2D only, although the formulation is fully presented in 3D. The result is applied in a study of the linear interaction between the acoustic and the hydrodynamic held in a 2D T-junction, subject to grazing flow at Mach 0.1. Part of the acoustic energy at the upstream edge of the junction is shed as harmonically oscillating disturbances, which are conveyed across the shear layer over the junction, where they interact with the acoustic field. As the acoustic waves travel in regions of strong shear, there is a need to include the interaction between the background turbulence and the acoustic field. For this purpose, the oscillation of the background turbulence Reynolds stress, due to the acoustic Field, is modeled using an eddy Newtonian model assumption. The time averaged flow is first solved for using RANS along with a k-epsilon turbulence model. The spatially varying turbulent eddy viscosity is then added to the spatially invariant kinematic viscosity in the acoustic set of equations. The response of the 2D T-junction to an incident acoustic field is analyzed via a plane wave scattering matrix model, and the result is compared to experimental data for a T-junction of rectangular ducts. A strong improvement in the agreement between calculation and experimental data is found when the modification proposed in this paper is implemented. Discrepancies remaining are likely due to inaccuracies in the selected turbulence model, which is known to produce large errors e.g. for flows with significant rotation, which the grazing flow across the T-junction certainly is A natural next step is therefore to test the proposed methodology together with more sophisticated turbulence models.
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| 10. |
- Holmberg, Andreas, 1982-, et al.
(författare)
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Aeroacoustics of rectangular T-junctions subject to combined grazing and bias flows - An experimental investigation
- 2015
-
Ingår i: Journal of Sound and Vibration. - : Elsevier BV. - 0022-460X .- 1095-8568. ; 340, s. 152-166
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Tidskriftsartikel (refereegranskat)abstract
- Scattering matrices are determined experimentally and used to study the low amplitude interaction, between the acoustic and the hydrodynamic fields in a T-junction of rectangular ducts. In particular, combinations of grazing and bias flows are investigated in the study. It is observed that for all flow combinations, waves incident on the junction at the downstream side only are attenuated, while waves incident at the other branches may be amplified or attenuated, depending on the Strouhal number. When bias in flow is introduced to a grazing flow, there is first an increase and then a decrease in both amplification and attenuation, as the bias in-flow Mach number is increased. Comparing with T-junctions of circular ducts, the interaction is stronger for rectangular duct junctions.
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| 11. |
- Holmberg, Christopher, 1984, et al.
(författare)
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Empowering aspects for healthy food and physical activity habits : adolescents’ experiences of a school-based intervention in a disadvantaged urban community
- 2018
-
Ingår i: International Journal of Qualitative Studies on Health and Well-being. - Abingdon : Taylor & Francis. - 1748-2623 .- 1748-2631. ; 13:sup1: Equal Health
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Tidskriftsartikel (refereegranskat)abstract
- Purpose:This study aimed to describe adolescents’ experiences of participating in a health-promoting school-based intervention regarding food and physical activity, with a focus on empowering aspects. Method:The school was located in a urban disadvantaged community in Sweden, characterized by poorer self-reported health and lower life expectancy than the municipality average. Focus group interviews with adolescents (29 girls, 20 boys, 14–15 years) and their teachers (n = 4) were conducted two years after intervention. Data were categorized using qualitative content analysis. Results: A theme was generated, intersecting with all the categories: Gaining control over one’s health: deciding, trying, and practicing together, in new ways, using reflective tools. The adolescents appreciated influencing the components of the intervention and collaborating with peers in active learning activities such as practicing sports and preparing meals. They also reported acquiring new health information, that trying new activities was inspiring, and the use of pedometers and photo-food diaries helped them reflect on their health behaviours. The adolescents’ experiences were also echoed by their teachers. Conclusions: To facilitate empowerment and stimulate learning, health-promotion interventions targeting adolescents could enable active learning activities in groups, by using visualizing tools to facilitate self-reflection, and allowing adolescents to influence intervention activities.
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| 12. |
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| 13. |
- Holmberg, Mats, et al.
(författare)
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Patient participation : A challenge within contemporary ambulance care?
- 2016
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Ingår i: PreHospen Conference 2016. - : Högskolan i Borås. ; , s. 82-82, s. 82-82
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- BackgroundPatient participation should be understood in relation to vulnerability, power and responsibility. Patients in ambulance care have urgent care needs and are vulnerable in an asymmetrical relationship with the clinicians. This places great responsibility on the clinicians to use their power for the benefit of the patient. An invitation to participate requires an informed consent and depends on the patient’s willingness and ability to participate. Hence, as- sessment of the patient’s decision-making ability is central together with a caring approach to enhance trust and confidence. Undoubtedly, patient partici- pation is a challenge within contemporary ambu- lance care – where failure is likely to cause suffering.MethodsPatient participation in ambulance care is discussed from philosophical, patient and person-centred perspectives in relation to empirical research of Bremer et al. (2012), Holmberg et al. (2014; 2015) and Rantala et al. (2015). ResultsPatients are comfortable in their surrender to ambulance clinicians, obeying commands and being important while involved in the care. However, pa- tients are powerless when they experience ambulan- ce clinicians’ care as excessive, having a strong desire of being acknowledged in their suffering. This can be achieved by seeing the patient as capable and in- volve the patient and significant others in the deci- sion-making. In addition ambulance clinicians have an ambition to be pliable to the patient’s wishes, inviting the patient in a shared decision-making.ConclusionsPatient participation in ambulance care can be understood as important for the patient’s wellbeing. However, unequal distribution of power within the ambulance clinician-patient relationship may challenge patient autonomy and interests. Is it pos- sible to achieve genuine patient participation in the context of ambulance care?
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| 14. |
- Holmberg, Mats, 1976-, et al.
(författare)
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Suffering and Togetherness On-scene in Prehospital emergency care (STOP) : a middle range theory
- 2019
-
Ingår i: Presented at the 3rd NCCS/EACS Conference: "Sustainable Caring for Health and Wellbeing", Vaasa, Finland, October 1-3, 2019.
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Konferensbidrag (refereegranskat)abstract
- Background: Prehospital emergency care provides care for patients of all ages and life situations and with a variety of suffering, diseases and injuries. Different caring aspects are required in order to respond to the patients’ needs, in parallel with medical assessment and treatment. In order to manage care in these unpredictable and complex contexts, the contextual caring science perspective needs to be developed. Aim: To develop a middle-range theory aimed at prehospital emergency care within a caring science framework. Method: A deductive and inductive design was used to generate understanding of the central concepts; the suffering human being, the caring relationship and the caring environment within prehospital emergency care. Result: The STOP theory comprises the concepts; acute suffering (S), act of togetherness (T), on-scene caring space (O) within in the contextual framework of prehospital emergency care (P). Acute suffering affects us without a clear warning, becoming acute. It means recognizing and accepting that one’s own resources are insufficient and completely exhausted. The ambulance clinician and the patient are in an act of togetherness from different positions and understandings, being dependent on each other to create conditions for continued care. This represents for patients an alteration from being in an involuntary and lonely struggle, to be cared for in a shared struggle to alleviate suffering. The on-scene caring space in which the clinician and the patient are situated are both a prerequisite for care and caring in itself. The space is not static but constantly changing and thus dynamic and elusive. Conclusion and implications: The STOP theory is important for clinical care, education and research in the prehospital emergency care setting as the theory is developed with an understanding of suffering as a wider phenomenon than the narrower biomedical perspective.
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| 15. |
- Holmberg, Ted, et al.
(författare)
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Dynamic Exhaust Valve Flow 1-D Modelling During Blowdown Conditions
- 2019
-
Ingår i: SAE Technical Papers. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191.
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Konferensbidrag (refereegranskat)abstract
- To conduct system level studies on internal combustionengines reduced order models are required in order tokeep the computational load below reasonable limits.By its nature a reduced order model is a simplification of realityand may introduce modeling errors. However what is of interestis the size of the error and if it is possible to reduce the errorby some method. A popular system level study is gas exchangeand in this paper the focus is on the exhaust valve. Generallythe valve is modeled as an ideal nozzle where the flow lossesare captured by reducing the flow area. As the valve movesslowly compared to the flow the process is assumed to be quasisteady,i.e. interpolation between steady-flow measurementscan be used to describe the dynamic process duringvalve opening. These measurements are generally done at lowpressure drops, as the influence of pressure ratio is assumed tobe negligible. As it is very difficult to measure time-resolvedmass flow it is hard to test validity of these modeling assumptions.Experimental data indicates that the model overestimatesvalve flow during the blowdown event. As the blowdown pulsecontains a significant portion of the energy in the cylinder atexhaust valve opening, it is therefore of importance to modelthis correctly. In this paper experimental results from previouslypublished research have been compared to simulationresults and the deviation from quasi-steady behavior has beenquantified. The deviation appears to be a function of pressureratio over the valve and valve opening speed. A model isproposed to compensate for the observed effects.
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| 16. |
- Holmberg, Ted, et al.
(författare)
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Impact of Dynamic Exhaust Valve Modelling
- 2019
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Konferensbidrag (refereegranskat)abstract
- A method developed in SAE 2019-01-0058 to correctfor deviations from quasi-steady exhaust valve flow isimplemented on a single-cylinder GT-Power modeland the effects on pumping work and blowdown pulsecharacteristics are investigated. The valve flow area isalways reduced compared to the referencequasi-steady case. It decreases with higher pressureratios over the valve and increases with higherengines speeds. The reduced flow area increasespumping work with load and engine speed, thoughprimarily with engine speed. The magnitude of theblowdown pulse is reduced and the peak is shifted toa later crank angle.
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| 17. |
- Holmberg, Ted, et al.
(författare)
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Pressure Amplitude Influence on Pulsating Exhaust Flow Energy Utilization
- 2018
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Ingår i: SAE technical paper series. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191. ; 2018-April
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Tidskriftsartikel (refereegranskat)abstract
- A turbocharged Diesel engine for heavy-duty on-road vehicle applications employs a compact exhaust manifold to satisfy transient torque and packaging requirements. The small exhaust manifold volume increases the unsteadiness of the flow to the turbine. The turbine therefore operates over a wider flow range, which is not optimal as radial turbines have narrow peak efficiency zone. This lower efficiency is compensated to some extent by the higher energy content of the unsteady exhaust flow compared to steady flow conditions. This paper experimentally investigates the relationship between exhaust energy utilization and available energy at the turbine inlet at different degrees of unsteady flow. A special exhaust manifold has been constructed which enables the internal volume of the manifold to be increased. The larger volume reduces the exhaust pulse amplitude and brings the operating condition for the turbine closer to steady-flow. The operating points are defined by engine speed and boost pressure. From these values the isentropic turbine work is calculated and with the measured compressor work the mean turbine efficiency is estimated. The results show that more energy has to be provided to the turbine at larger exhaust manifold volumes to maintain a constant boost pressure, indicating that the efficiency of the turbine decreases.
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| 18. |
- Holmberg, Ted, et al.
(författare)
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Pressure Ratio Influence on Exhaust Valve Flow Coefficients
- 2017
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Ingår i: SAE technical paper series. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191. ; 2017-March:March
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Tidskriftsartikel (refereegranskat)abstract
- In one dimensional engine simulation software, flow losses over complex geometries such as valves and ports are described using flow coefficients. It is generally assumed that the pressure ratio over the valve has a negligible influence on the flow coefficient. However during the exhaust valve opening the pressure difference between cylinder and port is large which questions the accuracy of this assumption. In this work the influence of pressure ratio on the exhaust valve flow coefficient has been investigated experimentally in a steady-flow test bench. Two cylinder heads, designated A and B, from a Heavy-Duty engine with different valve shapes and valve seat angles have been investigated. The tests were performed with both exhaust valves open and with only one of the two exhaust valves open. The pressure ratio over the exhaust port was varied from 1.1:1 to 5:1. For case A1 with a single exhaust valve open, the flow coefficient decreased significantly with pressure ratio. This trend was not replicated for the other single valve case B1, as pressure ratio only had a small influence on the flow coefficient. For the twin valve case A2, the pressure ratio influence was confined to the lower range of valve lifts as the limiting factor was the exhaust port outlet at higher valve lifts. The flow coefficient for the twin valve case B2 increased with pressure ratio in the mid-range of valve lifts.
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| 19. |
- Klyuchnikov, Evgeny, et al.
(författare)
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Reduced-Intensity Allografting as First Transplantation Approach in Relapsed/Refractory Grades One and Two Follicular Lymphoma Provides Improved Outcomes in Long-Term Survivors
- 2015
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Ingår i: Biology of blood and marrow transplantation. - : Elsevier BV. - 1083-8791 .- 1523-6536. ; 21:12, s. 2091-2099
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Tidskriftsartikel (refereegranskat)abstract
- This study was conducted to compare long-term outcomes in patients with refractory/relapsed grades 1 and 2 follicular lymphoma (FL) after allogeneic (allo) versus autologous (auto) hematopoietic cell transplantation (HCT) in the rituximab era. Adult patients with relapsed/refractory grades 1 and 2 FL undergoing first reduced-intensity allo-HCT or first autograft during 2000 to 2012 were evaluated. A total of 518 rituximab-treated patients were included. Allo-HCT patients were younger and more heavily pretreated, and more patients had advanced stage and chemoresistant disease. The 5-year adjusted probabilities, comparing auto-HCT versus allo-HCT groups for nonrelapse mortality (NRM) were 5% versus 26% (P <.0001); relapse/progression: 54% versus 20% (P <.0001); progression-free survival (PFS): 41% versus 58% (P <.001), and overall survival (OS): 74% versus 66% (P =.05). Auto-HCT was associated with a higher risk of relapse/progression beyond 5 months after HCT (relative risk [RR], 4.4; P <.0001) and worse PFS (RR, 2.9; P <.0001) beyond 11 months after HCT. In the first 24 months after HO', auto-HCT was associated with improved OS (RR,.41; P <.0001), but beyond 24 months, it was associated with inferior OS (RR, 2.2; P =.006). A landmark analysis of patients alive and progression-free at 2 years after HO' confirmed these observations, showing no difference in further NRM between both groups, but there was significantly higher risk of relapse/progression (RR, 7.3; P <.0001) and inferior PFS (RR, 3.2; P <.0001) and OS (RR, 2.1; P =.04) after auto-HCT. The 10-year cumulative incidences of second hematological malignancies after allo-HCT and auto-HCT were 0% and 7%, respectively. Auto-HCT and reduced-intensity conditioned allo-HCT as first transplantation approach can provide durable disease control in grades 1 and 2 FL patients. Continued disease relapse risk after auto-HCT translates into improved PFS and OS after allo-HCT in long-term survivors.
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| 20. |
- Pettersson, Andreas, et al.
(författare)
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The ABC model of prostate cancer : A conceptual framework for the design and interpretation of prognostic studies
- 2017
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Ingår i: Cancer. - Hoboken, USA : John Wiley & Sons. - 0008-543X .- 1097-0142. ; 123:9, s. 1490-1496
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Forskningsöversikt (refereegranskat)abstract
- There has been limited success in identifying prognostic biomarkers in prostate cancer. A partial explanation may be that insufficient emphasis has been put on clearly defining what type of marker or patient category a biomarker study aims to identify and how different cohort characteristics affect the ability to identify such a marker. In this article, the authors put forth the ABC model of prostate cancer, which defines 3 groups of patients with localized disease that an investigator may seek to identify: patients who, within a given time frame, will not develop metastases even if untreated (category A), will not develop metastases because of radical treatment (category B), or will develop metastases despite radical treatment (category C). The authors demonstrate that follow-up time and prostate-specific antigen screening intensity influence the prevalence of patients in categories A, B, and C in a study cohort, and that prognostic markers must be tested in both treated and untreated cohorts to accurately distinguish the 3 groups. The authors suggest that more emphasis should be put on considering these factors when planning, conducting, and interpreting the results from prostate cancer biomarker studies, and propose the ABC model as a framework to aid in that process.
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| 21. |
- Welde, Boye, et al.
(författare)
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The pacing strategy and technique of male cross-country skiers with different levels of performance during a 15-km classical race
- 2017
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 12:11
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Tidskriftsartikel (refereegranskat)abstract
- In this study the pacing strategy, cycle characteristics and choice of technique of elite male cross-country (XC) skiers during a three-lap, 15-km classical race with interval start were measured. During the Norwegian Championships in 2016, fast (n = 18, age: 26±4 yr; height: 182±4 cm; body mass: 78±3 kg (means±SD)) and slow skiers (n = 18, age: 22±2 yr; height: 183±5 cm; body mass: 78±6 kg) were video recorded on flat (0), intermediate (3.5) and uphill sections (7.1) of the first and final laps. All skiers adopted a positive pacing strategy, skiing more slowly (11.8%) with shorter cycles (11.7%) on the final than first lap (both p<0.001; pη2 = 0.93 and 0.87, respectively). The fast skiers were 7.0% faster overall (p<0.001, d = 4.20), and 6.1% (p<0.001, d = 3.32) and 7.0% (p<0.001, d = 3.68) faster on the first and final laps, respectively, compared to slower skiers. On all sections of both laps, the fast skiers exhibited 9.5% more rapid (pη2 = 0.74) and 8.9% (pη2 = 0.48) longer cycles (both p<0.001). On intermediate terrain, the fast skiers employed primarily double poling (DP, 38.9% on the first lap) and double poling with a kick (DPKICK, 50% on the final lap). In contrast, the slow skiers utilized for the most part DP alone (lap 1: 33.3%, lap 3: 38.9%) or in combination with other techniques (lap 1: 33.3%, lap 3: 38.9%) and decreased their usage of DPKICK from 27.8% on the first to 16.7% on the final lap. Skiing velocity on flat and intermediate terrain proved to be the best predictor of race performance (p<0.001). In conclusion, during a 15-km classical XC skiing race, velocity and cycle length decreased from the first to the final lap, most extensively on flat terrain and least uphill. Moreover, on the intermediate sections the fast and slow skiers chose to use different techniques.
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