| 1. |
- Moberg, Christina, et al.
(författare)
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De unga gör helt rätt när de stämmer staten
- 2022
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Ingår i: Aftonbladet. - 1103-9000.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- 1 620 forskare och lärare i forskarvärlden: Vi ställer oss bakom Auroras klimatkrav
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| 2. |
- Ursby, Thomas, et al.
(författare)
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BioMAX the first macromolecular crystallography beamline at MAX IV Laboratory
- 2020
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Ingår i: Journal of Synchrotron Radiation. - Chichester : Wiley-Blackwell. - 0909-0495 .- 1600-5775. ; 27, s. 1415-1429
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Tidskriftsartikel (refereegranskat)abstract
- BioMAX is the first macromolecular crystallography beamline at the MAX IV Laboratory 3 GeV storage ring, which is the first operational multi-bend achromat storage ring. Due to the low-emittance storage ring, BioMAX has a parallel, high-intensity X-ray beam, even when focused down to 20 μm × 5 μm using the bendable focusing mirrors. The beam is tunable in the energy range 5-25 keV using the in-vacuum undulator and the horizontally deflecting double-crystal monochromator. BioMAX is equipped with an MD3 diffractometer, an ISARA high-capacity sample changer and an EIGER 16M hybrid pixel detector. Data collection at BioMAX is controlled using the newly developed MXCuBE3 graphical user interface, and sample tracking is handled by ISPyB. The computing infrastructure includes data storage and processing both at MAX IV and the Lund University supercomputing center LUNARC. With state-of-the-art instrumentation, a high degree of automation, a user-friendly control system interface and remote operation, BioMAX provides an excellent facility for most macromolecular crystallography experiments. Serial crystallography using either a high-viscosity extruder injector or the MD3 as a fixed-target scanner is already implemented. The serial crystallography activities at MAX IV Laboratory will be further developed at the microfocus beamline MicroMAX, when it comes into operation in 2022. MicroMAX will have a 1 μm × 1 μm beam focus and a flux up to 1015 photons s with main applications in serial crystallography, room-temperature structure determinations and time-resolved experiments.
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| 3. |
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| 4. |
- Andersson, Magnus V., et al.
(författare)
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Kirurgi – omistligt komplement till medicinsk behandling
- 2009
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Ingår i: Läkartidningen. - 0023-7205 .- 1652-7518. ; 106:45, s. 3003-9
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Tidskriftsartikel (refereegranskat)abstract
- Kirurgi på rätt indikation och vid rätt tidpunkt är ett omistligt komplement till medicinsk behandling vid inflammatorisk tarmsjukdom, som förebygger sjukdomskomplikationer, förbättrar patienternas livskvalitet och ibland är livräddande. Kirurgi för ulcerös kolit görs oftast som ett tvåstegsförfarande: först kolektomi plus ileostomi med rektum lämnad intakt och i senare skede, med optimerad patient, tarmrekonstruktion anpassad efter patientens individuella livssituation. Kirurgi vid Crohns sjukdom korrigerar komplikationer (stenoser och fistlar) och sparar tarm genom begränsade resektioner och strikturplastiker. Laparoskopisk kirurgi verkar ha viktiga fördelar vid primära tarmresektioner. Modern medicinsk behandling har förändrat indikationerna men ännu inte minskat behovet av kirurgi. Pågående antiinflammatorisk och immunmodulerande behandling är viktig att beakta i samband med kirurgi. Ett nära samspel mellan gastroenterolog och kolorektalkirurg är nödvändigt för att uppnå bästa möjliga långtidsprognos för de individer som lever med IBD.
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| 5. |
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| 6. |
- Bech-Hanssen, Odd, 1956, et al.
(författare)
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Pressure reflection in the pulmonary circulation in patients with severe mitral regurgitation indicates adverse postoperative outcome.
- 2013
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Ingår i: European Journal Cardio-Thoracic Surgery. - : Oxford University Press (OUP). - 1010-7940 .- 1873-734X. ; 44:6, s. 1037-1044
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Severe pulmonary hypertension (PH) is a known risk factor in valvular surgery. In the present study, we hypothesized that the assessment of pressure reflection (PR) in the pulmonary circulation, indicating increased pulmonary vascular resistance, might improve the identification of patients with increased morbidity and mortality following surgery for severe mitral regurgitation. METHODS: A total of 103 patients without atrial fibrillation were divided into three groups: Group 1 (n = 48), patients without PR; Group 2 (n = 36), patients with PR and pulmonary artery systolic pressure (PASP) ≤60 mmHg and Group 3 (n = 19), patients with PR and PASP >60 mmHg. Three variables related to PR were selected: the acceleration time in the right ventricular outflow tract (RVOT), the interval between peak velocity in the RVOT and peak tricuspid regurgitant jet velocity and the right ventricular pressure increase after peak RVOT velocity. RESULTS: There were no differences between groups in age, ejection fraction, need for coronary bypass grafting or creatinine. Patients with PR (Groups 2 and 3) had more use of vasoactive drugs (overall P < 0.0001, Group 1 vs Group 2 P = 0.018). The proportion of patients with >24 h in the intensive care unit was 27% in Group 1, 54% in Group 2 and 84% in Group 3 (overall P < 0.0001, Group 1 vs Group 2 P = 0.006). The in-hospital mortality in patients without PR (n = 49) was 0% compared with 10.9% in patients with PR (P = 0.029). CONCLUSIONS: Echocardiography assessment of PR in the pulmonary circulation and severe PH may identify patients with adverse outcome following mitral surgery.
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| 7. |
- Bjursten, Henrik, et al.
(författare)
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Once after a full moon : acute type A aortic dissection and lunar phases
- 2022
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Ingår i: Interactive Cardiovascular and Thoracic Surgery. - : Oxford University Press. - 1569-9293 .- 1569-9285. ; 34:1, s. 105-110
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Acute type A aortic dissection (ATAAD) is a rare but severe condition, routinely treated with emergent cardiac surgery. Many surgeons have the notion that patients with ATAAD tend to come in clusters, but no studies have examined these observations. This investigation was undertaken to study the potential association between the lunar cycle and the incidence of ATAAD.METHODS: We collected information on 2995 patients who underwent ATAAD surgery at centres from the Nordic Consortium for Acute Type A Aortic Dissection collaboration. We cross-referenced the time of surgery with lunar phase using a case-crossover design with 2 different definitions of full moon (>99% illumination and the 7-day full moon period).RESULTS: The period when the moon was illuminated the most (99% definition) did not show any significant increase in incidence for ATAAD surgery. However, when the full moon period was compared with all other moon phases, it yielded a relative risk of 1.08 [95% confidence interval (CI) 1.00-1.17, P = 0.057] and, compared to waxing moon, only the relative risk was 1.11 (95% CI 1.01-1.23, P = 0.027). The peak incidence came 4-6 days after the moon was fully illuminated.CONCLUSIONS: This study found an overrepresentation of surgery for ATAAD during the full moon phase. The explanation for this is not known, but we speculate that sleep deprivation during full moon leads to a temporary increase in blood pressure, which in turn could trigger rupture of the aortic wall. While this finding is interesting, it needs to be corroborated and the clinical implications are debateable.
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| 8. |
- Björklund, Erik, et al.
(författare)
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Comparison of Midterm Outcomes Associated With Aspirin and Ticagrelor vs Aspirin Monotherapy After Coronary Artery Bypass Grafting for Acute Coronary Syndrome.
- 2021
-
Ingår i: JAMA network open. - : American Medical Association (AMA). - 2574-3805. ; 4:8
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Tidskriftsartikel (refereegranskat)abstract
- Guidelines recommend dual antiplatelet therapy after coronary artery bypass grafting (CABG) for patients with acute coronary syndrome (ACS). However, the evidence for these recommendations is weak.To compare midterm outcomes after CABG in patients with ACS treated postoperatively with acetylsalicylic acid (ASA) and ticagrelor or with ASA monotherapy.This cohort study used merged data from several national registries of Swedish patients who were diagnosed with ACS and subsequently underwent CABG. All included patients underwent isolated CABG in Sweden between 2012 and 2017 with an ACS diagnosis less than 6 weeks before the procedure, survived 14 days after discharge from hospital, and were treated postoperatively with ASA plus ticagrelor or ASA monotherapy. A multivariable Cox regression model was used for the main analysis, and propensity score-matched models were performed as sensitivity analysis. Data were analyzed between May and September 2020.Postoperative antiplatelet treatment, defined as filled prescriptions, with either ASA and ticagrelor or ASA only.Major adverse cardiovascular events (MACE), defined as all-cause mortality, myocardial infarction, and stroke, and major bleeding, at 12 months and at the end of follow-up.A total of 6558 patients (5281 [80.5%] men; mean [SD] age at surgery, 67.6 [9.3] years) were included; 1813 (27.6%) were treated with ASA plus ticagrelor and 4745 (72.4%) were treated with ASA monotherapy. Crude MACE rate was 3.0 per 100 person years (95% CI, 2.5-3.6 per 100 person years) in the ASA plus ticagrelor group and 3.8 per 100 person years (95% CI, 3.5-4.1 per 100 person years) in the ASA group. After adjustment, there was no significant difference in MACE risk between ASA plus ticagrelor vs ASA only, neither during the first 12 months (adjusted hazard ratio [aHR], 0.84; 95% CI, 0.58-1.21; P=.34) or during total follow-up (aHR, 0.89; 95% CI, 0.71-1.11; P=.29). The use of ASA plus ticagrelor was associated with a significantly increased risk for major bleeding during the first 12 months (aHR, 1.90; 95% CI, 1.16-3.13; P=.011). Sensitivity analyses confirmed the results.In patients with ACS who survived 2 weeks after CABG, no significant difference in the risk of death or ischemic events could be demonstrated between ASA plus ticagrelor and patients treated with ASA only, while the risk for major bleeding was higher in patients treated with ASA plus ticagrelor. Sufficiently powered prospective randomized trials comparing different antiplatelet therapy strategies after CABG are warranted.
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| 9. |
- Björklund, Erik, et al.
(författare)
-
Postdischarge major bleeding, myocardial infarction, and mortality risk after coronary artery bypass grafting
- 2023
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Ingår i: HEART. - 1355-6037 .- 1468-201X.
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Tidskriftsartikel (refereegranskat)abstract
- Objective To investigate the incidence and mortality risk associated with postdischarge major bleeding after coronary artery bypass grafting (CABG), and relate this to the incidence of, and mortality risk from, postdischarge myocardial infarction.Methods All patients undergoing first-time isolated CABG in Sweden in 2006-2017 and surviving 14 days after hospital discharge were included in a cohort study. Individual patient data from the SWEDEHEART Registry and five other mandatory nationwide registries were merged. Piecewise Cox proportional hazards models were used to investigate associations between major bleeding, defined as hospitalisation for bleeding, with subsequent mortality risk. Similar Cox proportional hazards models were used to investigate the association between postdischarge myocardial infarction and mortality risk.Results Among 36 633 patients, 2429 (6.6%) had a major bleeding event and 2231 (6.1%) had a myocardial infarction. Median follow-up was 6.0 (range 0-11) years. Major bleeding was associated with higher mortality risk <30 days (adjusted HR (aHR)=20.2 (95% CI 17.3 to 23.5)), 30-365 days (aHR=3.8 (95% CI 3.4 to 4.3)) and >365 days (aHR=1.8 (95% CI 1.7 to 2.0)) after the event. Myocardial infarction was associated with higher mortality risk <30 days (aHR=20.0 (95% CI 16.7 to 23.8)), 30-365 days (aHR=4.1 (95% CI 3.6 to 4.8)) and >365 days (aHR=1.8 (95% CI 1.7 to 2.0)) after the event.Conclusions The increase in mortality risk associated with a postdischarge major bleeding after CABG is substantial and is similar to the mortality risk associated with a postdischarge myocardial infarction.
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| 10. |
- Björklund, Erik, et al.
(författare)
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Postoperative platelet function is associated with severe bleeding in ticagrelor-treated patients
- 2019
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Ingår i: Interactive Cardiovascular and Thoracic Surgery. - : Oxford University Press (OUP). - 1569-9293 .- 1569-9285. ; 28:5, s. 709-715
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Preoperative testing of platelet function predicts bleeding risk in cardiac surgery patients treated with dual antiplatelet therapy, but the value of postoperative platelet function testing, reflecting both preoperative antiplatelet therapy and perioperative changes in platelet function, has not been evaluated. Methods: Seventy-four patients with acute coronary syndrome treated with acetylsalicylic acid and ticagrelor within 5 days before cardiac surgery were included in a prospective observational study. Platelet aggregation induced by adenosine diphosphate, arachidonic acid and thrombin receptor-activating peptide was assessed with multiple electrode impedance aggregometry immediately before surgery and 2 h after weaning off cardiopulmonary bypass. Receiver operating characteristic curves were used to determine any association between platelet aggregation and severe bleeding according to the universal definition of perioperative bleeding in adult cardiac surgery. Results: Severe bleeding occurred in 25 of 74 patients (34%). Preoperative and postoperative adenosine diphosphate-induced platelet aggregations were associated with bleeding, with comparable areas under the receiver operating characteristic curve [0.77 (95% confidence interval 0.65-0.89) vs 0.75 (0.62-0.87)]. Postoperative arachidonic acid-and thrombin receptor-activating peptide-induced aggregation had markedly smaller areas under the curve. There were significant correlations between preoperative and postoperative platelet aggregation induced by adenosine diphosphate (r2 = 0.77, P < 0.001), arachidonic acid (r2 = 0.24, P < 0.001) and thrombin receptoractivating peptide (r2 = 0.21, P < 0.001) but with large interindividual variations. Conclusions: Poor postoperative platelet function was associated with severe bleeding, with accuracy comparable to that of preoperative platelet function. There was a correlation between preoperative and postoperative platelet function, but the predictability in an individual patient was limited. © 2018 The Author(s). Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
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| 11. |
- Björklund, Erik, et al.
(författare)
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Secondary prevention medications after coronary artery bypass grafting and long-term survival : a population-based longitudinal study from the SWEDEHEART registry.
- 2019
-
Ingår i: European Heart Journal. - : Oxford University Press. - 0195-668X .- 1522-9645. ; 41:17, s. 1653-1661
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: To evaluate the long-term use of secondary prevention medications [statins, β-blockers, renin-angiotensin-aldosterone system (RAAS) inhibitors, and platelet inhibitors] after coronary artery bypass grafting (CABG) and the association between medication use and mortality.METHODS AND RESULTS: All patients who underwent isolated CABG in Sweden from 2006 to 2015 and survived at least 6 months after discharge were included (n = 28 812). Individual patient data from SWEDEHEART and other mandatory nationwide registries were merged. Multivariable Cox regression models using time-updated data on dispensed prescriptions were used to assess associations between medication use and long-term mortality. Statins were dispensed to 93.9% of the patients 6 months after discharge and to 77.3% 8 years later. Corresponding figures for β-blockers were 91.0% and 76.4%, for RAAS inhibitors 72.9% and 65.9%, and for platelet inhibitors 93.0% and 79.8%. All medications were dispensed less often to patients ≥75 years. Treatment with statins [hazard ratio (HR) 0.56, 95% confidence interval (95% CI) 0.52-0.60], RAAS inhibitors (HR 0.78, 95% CI 0.73-0.84), and platelet inhibitors (HR 0.74, 95% CI 0.69-0.81) were individually associated with lower mortality risk after adjustment for age, gender, comorbidities, and use of other secondary preventive drugs (all P < 0.001). There was no association between β-blockers and mortality risk (HR 0.97, 95% CI 0.90-1.06; P = 0.54).CONCLUSION: The use of secondary prevention medications after CABG was high early after surgery but decreased significantly over time. The results of this observational study, with inherent risk of selection bias, suggest that treatment with statins, RAAS inhibitors, and platelet inhibitors is essential after CABG whereas the routine use of β-blockers may be questioned.
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| 12. |
- Chen, Q., et al.
(författare)
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Analytical treatment of diffusion during precipitate growth in multicomponent systems
- 2008
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Ingår i: Acta Materialia. - : Elsevier BV. - 1359-6454 .- 1873-2453. ; 56:8, s. 1890-1896
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Tidskriftsartikel (refereegranskat)abstract
- We propose an approximate growth rate equation that takes into account both cross-diffusion and high supersaturations for modeling precipitation in multicomponent systems. We then apply it to an Fe-alloy in which interstitial C atoms diffuse much faster than substitutional solutes, and predict a spontaneous transition from slow growth under ortho-equilibrium to fast growth under the non-partitioning local equilibrium condition. The transition is caused by the decrease in the Gibbs-Thomson effect as the growing particle becomes larger. The results agree with DICTRA simulations where full diffusion fields are calculated.
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| 13. |
- Ding, Jielan, et al.
(författare)
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The link between ethnic diversity and scientific impact : the mediating effect of novelty and audience diversity
- 2021
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Ingår i: Scientometrics. - : Springer Nature. - 0138-9130 .- 1588-2861. ; 126:9, s. 7759-7810
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the nature and value of scientific collaboration is essential for sound management and proactive research policies. One component of collaboration is the composition and diversity of contributing authors. This study explores how ethnic diversity in scientific collaboration affects scientific impact, by presenting a conceptual model to connect ethnic diversity, based on author names, with scientific impact, assuming novelty and audience diversity as mediators. The model also controls for affiliated country diversity and affiliated country size. Using path modeling, we apply the model to the Web of Science subject categories Nanoscience & Nanotechnology, Ecology and Information Science & Library. For all three subject categories, and regardless of if control variables are considered or not, we find a weak positive relationship between ethnic diversity and scientific impact. The relationship is weaker, however, when control variables are included. For all three fields, the mediated effect through audience diversity is substantially stronger than the mediated effect through novelty in the relationship, and the former effect is much stronger than the direct effect between the ethnic diversity and scientific impact. Our findings further suggest that ethnic diversity is more associated with short-term scientific impact compared to long-term scientific impact.
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| 14. |
- Forsberg, Anton, et al.
(författare)
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Low background and high contrast PET imaging of amyloid-β with [11C]AZD2995 and [11C]AZD2184 in Alzheimer's disease patients
- 2013
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer-Verlag New York. - 1619-7070 .- 1619-7089. ; 40:4, s. 580-593
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The aim of this study was to evaluate AZD2995 side by side with AZD2184 as novel PET radioligands for imaging of amyloid-β in Alzheimer's disease (AD).METHODS: In vitro binding of tritium-labelled AZD2995 and AZD2184 was studied and compared with that of the established amyloid-β PET radioligand PIB. Subsequently, a first-in-human in vivo PET study was performed using [(11)C]AZD2995 and [(11)C]AZD2184 in three healthy control subjects and seven AD patients.RESULTS: AZD2995, AZD2184 and PIB were found to share the same binding site to amyloid-β. [(3)H]AZD2995 had the highest signal-to-background ratio in brain tissue from patients with AD as well as in transgenic mice. However, [(11)C]AZD2184 had superior imaging properties in PET, as shown by larger effect sizes comparing binding potential values in cortical regions of AD patients and healthy controls. Nevertheless, probably due to a lower amount of nonspecific binding, the group separation of the distribution volume ratio values of [(11)C]AZD2995 was greater in areas with lower amyloid-β load, e.g. the hippocampus.CONCLUSION: Both AZD2995 and AZD2184 detect amyloid-β with high affinity and specificity and also display a lower degree of nonspecific binding than that reported for PIB. Overall [(11)C]AZD2184 seems to be an amyloid-β radioligand with higher uptake and better group separation when compared to [(11)C]AZD2995. However, the very low nonspecific binding of [(11)C]AZD2995 makes this radioligand potentially interesting as a tool to study minute levels of amyloid-β. This sensitivity may be important in investigating, for example, early prodromal stages of AD or in the longitudinal study of a disease modifying therapy.
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| 15. |
- Forsberg, Ulrika, et al.
(författare)
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First Experiment at TASCA Towards X-Ray Fingerprinting of Element 115 Decay Chains
- 2012
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Ingår i: Acta Physica Polonica. Series B: Elementary Particle Physics, Nuclear Physics, Statistical Physics, Theory of Relativity, Field Theory. - 0587-4254. ; 43:2, s. 305-311
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Tidskriftsartikel (refereegranskat)abstract
- To identify the atomic number of superheavy nuclei produced in Ca-48-induced fusion-evaporation reactions, an experiment aiming at measuring characteristic X-rays is being prepared at GSI, Darmstadt, Germany. The gas-filled separator TASCA will be employed, sending the residues towards the multi-coincidence detector setup TASISpec. Two ion-optical modes relying on differing magnetic polarities of the quadrupole magnets can be used at TASCA. New simulations and experimental tests of transmission and background suppression for these two focusing modes into TASISpec are presented.
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| 16. |
- Granbom, Ylva, et al.
(författare)
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Simulation of the Soaking and Gas Jet Cooling in a Continuous Annealing Line using Dilatometry
- 2010
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Ingår i: Steel Research International. - : Wiley. - 1611-3683 .- 1869-344X. ; 81:2, s. 158-167
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Tidskriftsartikel (refereegranskat)abstract
- The present study concerns the simulation of a continuous annealing line (CAL), using dilatometry. Simulations of CAL have been performed on four commercial steel grades with different chemical compositions in order to investigate how the alloying elements C, Mn, Si and B affect the microstructure and hardness of dual phase (DP) and martensitic steels. Three annealing cycles corresponding to those used in a CAL have been applied. When annealing intercritically, as is the case in DP-steel production, the materials do not reach equilibrium during soaking. Mn and C increase the austenite content and consequently the hardness of the materials. Higher levels of Si (0.4 wt %) are required to retard the formation of new ferrite during cooling in the gas jet section, prior to quenching. 6 increases hardenability effectively when annealing in the austenite region but is not as efficient during intercritical annealing, which implies that boron restrains ferrite nucleation rather than impeding ferrite growth. Results from DICTRA calculations show that it is possible to simulate the phase transformations during soaking, gasjet cooling and quenching.
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| 17. |
- Gudbjartsson, Tomas, et al.
(författare)
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Sternal wound infections following open heart surgery – a review
- 2016
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Ingår i: Scandinavian Cardiovascular Journal. - : Informa UK Limited. - 1401-7431 .- 1651-2006. ; 50:5-6, s. 341-348
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Forskningsöversikt (refereegranskat)abstract
- Surgical site infections (SSIs) are common complications after open heart surgery. Fortunately, most are superficial and respond to minor wound debridement and antibiotics. However, 1–3% of patients develop deep sternal wound infections that can be fatal. Late infections with sternocutaneous fistulas, are encountered less often, but represent a complex surgical problem. This evidence-based review covers etiology, risk factors, prevention and treatment of sternal SSIs following open heart surgery with special focus on advances in treatment, especially negative-pressure wound therapy.
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| 18. |
- Gäbel, Jakob, 1971, et al.
(författare)
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Cell saver processing mitigates the negative effects of wound blood on platelet function
- 2016
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Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172. ; 60:7, s. 901-909
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundWound blood is highly activated and has poor haemostatic properties. Recent data suggest that retransfusion of unwashed wound blood may impair haemostasis. We hypothesized that cell saver processing of wound blood before retransfusion reduces the negative effects. MethodsWound blood was collected from 16 cardiac surgery patients during cardiopulmonary bypass. One portion of the wound blood was processed in a cell saver and one portion left unprocessed. Increasing amounts of unprocessed blood (10% and 20% of the systemic blood volume) or corresponding volumes of processed blood were added ex vivo to whole blood samples from the same patient. Clot formation was assessed by modified thromboelastometry (ROTEM (R)) and platelet function with impedance aggregometry (Multiplate((R))). ResultsAddition of unprocessed wound blood significantly impaired clot formation and platelet aggregability. Cell saver processing before addition did not influence clot formation but abolished completely the negative effects of wound blood on platelet aggregability tested with all agonists. Median adenosine diphosphate-induced platelet aggregation was 51 (25th and 75th percentiles 42-69) when 20% processed cardiotomy suction blood was added vs. 34 (24-52) U when 20% unprocessed blood was added, P < 0.001. The corresponding figures for arachidonic acid-, thrombin receptor activating peptide- and collagen-induced aggregation was 21 (17-51) vs. 13 (10-25) U, 112 (87-128) vs. 78 (65-103) U and 58 (50-73) vs. 33 (28-44) U, respectively, all P < 0.001). ConclusionThe results suggest that cell saver processing before retransfusion mitigates the negative effects of wound blood on platelet function despite that cell saver processing reduces platelet count.
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| 19. |
- Hansson, Emma C., 1985, et al.
(författare)
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Platelet function recovery after ticagrelor withdrawal in patients awaiting urgent coronary surgery
- 2017
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Ingår i: European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery. - : Oxford University Press (OUP). - 1010-7940 .- 1873-734X. ; 51:4, s. 633-637
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Dual antiplatelet therapy with ticagrelor and aspirin is associated with an increased risk of perioperative bleeding complications. Current guidelines recommend therefore discontinuation of ticagrelor 5 days before surgery to allow sufficient recovery of platelet function. It is not known how the time to recovery varies between individual patients after discontinuation of ticagrelor. METHODS: Twenty-five patients accepted for urgent coronary artery bypass surgery and treated with ticagrelor and aspirin were included in a prospective observational study. Platelet aggregation was evaluated with impedance aggregometry at five timepoints 12-96 h after discontinuation of ticagrelor. In a subset of patients (n = 15), we also tested the ex vivo efficacy of platelet concentrate supplementation on platelet aggregation. RESULTS: There was a gradual increase in mean adenosine diphosphate-induced platelet aggregation after discontinuation of ticagrelor. After 72 h, mean aggregation was 38 +/-23 aggregation units (U), which is above a previously suggested cut-off of 22 U, when patients can be operated without increased bleeding risk. However, there was a large interindividual variability (range 488 U at 72 h) and 6/24 patients (25%) had <22 U after 72 h. Ex vivo administration of platelet concentrate did not improve adenosine diphosphate-induced aggregation at any timepoint after ticagrelor discontinuation. CONCLUSIONS: Adenosine diphosphate-induced aggregation was acceptable after 72 h in the majority of patients but with a large interindividual variability. Due to the large variability, platelet function testing may prove to be a valuable tool in timing of surgery in patients with ongoing or recently stopped ticagrelor treatment. Adenosine diphosphate-induced aggregation was not improved by addition of platelet concentrate.
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| 20. |
- Isaksson, Ola, et al.
(författare)
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Trends in product modelling : an ENDREA perspective
- 2000
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Ingår i: Proceedings / Produktmodeller 2000. - Linköping : Linköping universitet.
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Konferensbidrag (refereegranskat)abstract
- The success of engineering companies is highly dependent on how well product information is managed, engineered and communicated. From marketing through development to after sales activities, data needs to be accessible and used in the best way. Today, geographical distance, the need for close co-operation and data complexity are all natural parts of the working environment. Product modelling techniques are continuously evolving with new requirements and opportunities emerging daily. This paper will outline and discuss some of these trends, and at the same time present some of the areas where research is being carried out within projects in the Product Model Cluster in the national graduate school - The Swedish Engineering Design Research and Education Agenda (ENDREA).
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| 21. |
- Jeppsson, Johan, et al.
(författare)
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Inverse Saltykov analysis for particle-size distributions and their time evolution
- 2011
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Ingår i: Acta Materialia. - : Elsevier BV. - 1359-6454 .- 1873-2453. ; 59:3, s. 874-882
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Tidskriftsartikel (refereegranskat)abstract
- In this work a new method for transforming 2-D to 3-D size distributions is proposed. A representation of the 2-D size distributions is constructed from the data of measured radii with a statistical method called the kernel density estimator. The method yields a smooth density estimation that is more accurate than the classic histogram. The 3-D distribution is optimized from the 2-D density estimate in an iterative manner. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
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| 22. |
- Jeppsson, Johan, et al.
(författare)
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Modeling of dispersoid precipitation in multicomponent alloys
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Ingår i: Acta Materialia. - 1359-6454 .- 1873-2453.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- A model for nucleation, growth and coarsening of precipitates in multicomponent, multiphase systems is presented. High supersaturation and volume fraction of theprecipitate phase are considered. Deviation from local equilibrium at the phaseinterface is treated by means of a model based on trans-interface diffusion. Anexample simulation predict a sudden transition from diffusion-controlled to massivegrowth during continues cooling of an Fe-5%Ni alloy. The precipitation model iscompared with experiments in the Al-Sc-Mg system. To calculate the equilibriumphases, the chemical driving forces, equilibrium concentrations and diffusivities, thecommercial softwares Thermo-Calc and Dictra were used. The main advantage ofthis strategy is that there is nearly no restriction on a special alloy system.
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| 23. |
- Jeppsson, Johan, et al.
(författare)
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Modified mean field models of normal grain growth
- 2008
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Ingår i: Acta Materialia. - : Elsevier BV. - 1359-6454 .- 1873-2453. ; 56:18, s. 5188-5201
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Tidskriftsartikel (refereegranskat)abstract
- Models of normal grain growth can either start from a postulated kinetic law for individual grains and yield a distribution of grain sizes or they can start from a postulated distribution and the kinetic law may be derived. Both methods are studied and a whole family of distributions based on new kinetic laws are derived using the first method. Both methods have recently been applied using Onsager's extremum principle but it is now shown that more classical procedures are sufficient. Kinetic laws give an indication of what physical factors govern the growth or shrinkage of individual grains. A Rayleigh's distribution seems to indicate that large grains are surrounded by grains smaller than the critical size and small grains are surrounded by grains larger than the critical size. The effects of the new family of kinetic laws on the development of grain size distributions are studied by numerical simulations.
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| 24. |
- Jeppsson, Johan
(författare)
-
Simulation of Phase Transformations and coarsening : Computational tools for alloy development
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The final properties of an alloy are highly interlaced with its microstructure. It is therefore essential to control the evolution of the microstructure of the material during the fabrication process. Nowadays, materials design involves an increasing part of computational design to complement the traditional experimental trial and error approach. Such simulations of the process can decrease the number of material prototypes and shorten the development time for new alloys. In this thesis several microstructure models, aimed for process design, have been suggested. The ambition has been to develop physically based models that are capable to represent the evolution of hundreds of grain or particle sizes, where the models should be possible to run on a standard computer with simulation times less than one day. To achieve this goal, simplified approaches have been suggested, which are accurate enough for the growth rate of grains and particles. The microstructure models have all in common that size distributions of grains or particles are simulated with mean-field approaches. Several of the models also utilize composition and temperature dependent thermodynamic and kinetic properties continually throughout the simulations. These properties have been calculated with programming interfaces to Thermo-Calc and DICTRA together with appropriate thermodynamic and kinetic databases. The materials that have been considered in the present thesis are low alloyed steels, aluminium alloys and cemented carbides. The models are however generic in the sense that all materials can be handled if appropriate thermodynamic, kinetic and property databases exist for the alloy.
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| 25. |
- Malm, Carl Johan, et al.
(författare)
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Dual or single antiplatelet therapy after coronary surgery for acute coronary syndrome (TACSI trial): Rationale and design of an investigator-initiated, prospective, multinational, registry-based randomized clinical trial
- 2023
-
Ingår i: American Heart Journal. - : Elsevier BV. - 0002-8703 .- 1097-6744. ; 259, s. 1-8
-
Tidskriftsartikel (refereegranskat)abstract
- The TACSI trial (ClinicalTrials.gov Identifier: NCT03560310) tests the hypothesis that 1-year treatment with dual antiplatelet therapy with acetylsalicylic acid (ASA) and ticagrelor is superior to only ASA after isolated coronary artery bypass grafting (CABG) in patients with acute coronary syndrome. The TACSI trial is an investor-initiated pragmatic, prospective, multinational, multicenter, open-label, registry-based randomized trial with 1:1 randomization to dual antiplatelet therapy with ASA and ticagrelor or ASA only, in patients undergoing first isolated CABG, with a planned enrollment of 2200 patients at Nordic cardiac surgery centers. The primary efficacy end point is a composite of time to all-cause death, myocardial infarction, stroke, or new coronary revascularization within 12 months after randomization. The primary safety end point is time to hospitalization due to major bleeding. Secondary efficacy end points include time to the individual components of the primary end point, cardiovascular death, and rehospitalization due to cardiovascular causes. High-quality health care registries are used to assess primary and secondary end points. The patients will be followed for 10 years. The TACSI trial will give important information useful for guiding the antiplatelet strategy in acute coronary syndrome patients treated with CABG.
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| 26. |
- Malm, Carl Johan, et al.
(författare)
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Preoperative platelet function predicts perioperative bleeding complications in ticagrelor-treated cardiac surgery patients: a prospective observational study
- 2016
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Ingår i: British Journal of Anaesthesia. - : Elsevier BV. - 0007-0912. ; 117:3, s. 309-315
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Tidskriftsartikel (refereegranskat)abstract
- Background: Treatment with P2Y(12) receptor antagonists increases the risk for perioperative bleeding, but there is individual variation in the antiplatelet effect and time to offset of this effect. We investigated whether preoperative platelet function predicts the risk of bleeding complications in ticagrelor-treated cardiac surgery patients. Methods: Ninety patients with ticagrelor treatment within <5 days of surgery were included in a prospective observational study. Preoperative platelet aggregation was assessed with impedance aggregometry using adenosine diphosphate (ADP), arachidonic acid (AA), and thrombin receptor-activating peptide (TRAP) as initiators. Severe bleeding complications were registered using a new universal definition of perioperative bleeding. The accuracy of aggregability tests for predicting severe bleeding was assessed using receiver operating characteristic (ROC) curves, which also identified optimal cut-off values with respect to sensitivity and specificity, based on Youden's index. Results: The median time from the last ticagrelor dose to surgery was 35 (range 4-108)h. The accuracy of platelet function tests to predict severe bleeding was highest for ADP [area under the ROC curve 0.73 (95% confidence interval 0.63-0.84, P<0.001); TRAP 0.61 (0.49-0.74); AA 0.53 (0.40-0.66)]. The optimal cut-off for ADP-induced aggregation was 22 U. In subjects with ADP-induced aggregation below the cut-off value, 24/38 (61%) developed severe bleeding compared with 8/52 (14%) when aggregation was at or above the cut-off value (P<0.001). The positive and negative predictive values for this cut-off value were 63 and 85%, respectively. Conclusions: Preoperative ADP-induced platelet aggregability predicts the risk for severe bleeding complications in ticagrelor-treated cardiac surgery patients.
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| 27. |
- Malm, Carl Johan, et al.
(författare)
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Small calibre biosynthetic bacterial cellulose blood vessels: 13-months patency in a sheep model.
- 2012
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Ingår i: Scandinavian Cardiovascular Journal. - : Informa UK Limited. - 1651-2006 .- 1401-7431. ; 46:1, s. 57-62
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Objectives. Many patients in need of bypass surgery lack graft material and current synthetic alternatives have poor performance. A 4 mm vascular graft composed of bacterial cellulose (BC) was developed and tested in pilot study in a large animal model. Design. BC is a biopolymer made by the bacteria acetobacter xylinum. BC grafts (n = 16) with 4 cm length and 4 mm internal diameter were implanted bilaterally in the carotid arteries of eight sheep. No long-term antithrombotic therapy was administered. Patency was assessed with ultrasound. Histology, immunohistochemistry, and electron microscopy were performed after explantation. Results. Fifty percent of the grafts occluded within two weeks. One animal died with patent grafts after 14 days. In the three remaining animals 5/6 grafts were patent after nine months. Two animals were followed 13 months after implantation with 3/4 grafts patent at explantation. All patent grafts had confluent endothelial-like cells. Conclusions. Biosynthetic small calibre vascular grafts made from BC can be patent for up to 13 months in sheep carotid arteries. BC is a potential material for small calibre grafts but patency in animal models needs to be improved before clinical studies can be planned.
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| 28. |
- Mannesson, Karin, et al.
(författare)
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Carbide grain growth in cemented carbides
- 2011
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Ingår i: Acta Materialia. - : Elsevier BV. - 1359-6454 .- 1873-2453. ; 59:5, s. 1912-1923
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Tidskriftsartikel (refereegranskat)abstract
- Abnormal grain growth is often observed in cemented carbides during sintering, but cannot be understood in terms of the classical LSW theory. In this work the grain growth behavior during sintering at 1430 °C is studied both experimentally and by means of computer simulations. A model based on several processes—2-D nucleation of growth ledges, mass transfer across the interface and long-range diffusion coupled in series—is formulated and the equations are solved numerically. Both computer simulations and experimental studies reveal that the grain growth behavior is strongly influenced by the initial size distribution.
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| 29. |
- Martinsson, Andreas, et al.
(författare)
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Renin-angiotensin system inhibition and outcome after coronary artery bypass grafting: A population-based study from the SWEDEHEART registry
- 2021
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Ingår i: International Journal of Cardiology. - : Elsevier BV. - 0167-5273. ; 331, s. 40-45
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Tidskriftsartikel (refereegranskat)abstract
- Background: Renin-angiotensin system (RAS) inhibitors are recommended postoperatively to coronary artery bypass grafting (CABG) patients with reduced left ventricular function, diabetes, hypertension or previous myocardial infarction, but not to remaining patients. The aim of the study was to assess the long-term utilization of RAS inhibitors after CABG in patients with and without indication for treatment, and its association with outcome. Methods: All patients (n = 28,782) not meeting exclusion criterion in Sweden who underwent isolated first time CABG from 2006 to 2015 were included using nationwide registries. The association between treatment and outcome was assessed using adjusted Cox regression models with time-updated data on medications. The primary outcome was major adverse cardiovascular events (MACE), defined as all-cause mortality, stroke and/or myocardial infarction. Results: At baseline 26,284 (91.3%) of the patients had at least one indication for RAS inhibition while 2498 (8.7%) had not. RAS inhibitors were dispensed to 77.0% and 29.7% of patients with and without indication respectively. Dispense declined over time. RAS inhibition was associated with a reduction in MACE in the whole study population (adjusted hazard ratio (aHR) 0.88, 95% confidence interval (95% CI) 0.83–0.93, p < 0.0001), and in patients with (aHR 0.87 95% CI: 0.82–0.93, p < 0.0001) and without indication (aHR 0.75, 95% CI: 0.58–0.98, p = 0.034). Conclusions: RAS inhibition is underutilized after CABG. The use of RAS inhibitors was associated with a reduction in MACE, both in patients with and without indication for treatment. The results suggest that RAS inhibition is beneficial for all CABG patients. Randomized controlled trials are necessary to confirm this hypothesis. © 2021 The Authors
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| 30. |
- Mattsson, Niklas, 1979, et al.
(författare)
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BACE1 inhibition induces a specific cerebrospinal fluid β-amyloid pattern that identifies drug effects in the central nervous system.
- 2012
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 7:2
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Tidskriftsartikel (refereegranskat)abstract
- BACE1 is a key enzyme for amyloid-β (Aβ) production, and an attractive therapeutic target in Alzheimer's disease (AD). Here we report that BACE1 inhibitors have distinct effects on neuronal Aβ metabolism, inducing a unique pattern of secreted Aβ peptides, analyzed in cell media from amyloid precursor protein (APP) transfected cells and in cerebrospinal fluid (CSF) from dogs by immunoprecipitation-mass spectrometry, using several different BACE1 inhibitors. Besides the expected reductions in Aβ1-40 and Aβ1-42, treatment also changed the relative levels of several other Aβ isoforms. In particular Aβ1-34 decreased, while Aβ5-40 increased, and these changes were more sensitive to BACE1 inhibition than the changes in Aβ1-40 and Aβ1-42. The effects on Aβ5-40 indicate the presence of a BACE1 independent pathway of APP degradation. The described CSF Aβ pattern may be used as a pharmacodynamic fingerprint to detect biochemical effects of BACE1-therapies in clinical trials, which might accelerate development of novel therapies.
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| 31. |
- Mölne, Johan, 1958, et al.
(författare)
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Blood group ABO antigen expression in human embryonic stem cells and in differentiated hepatocyte- and cardiomyocyte-like cells.
- 2008
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Ingår i: Transplantation. - 1534-6080. ; 86:10, s. 1407-13
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The use of stem cells in regenerative medicine and transplantation may require grafting of cells that will challenge the recipient's immune system. Our knowledge of tissue antigen expression in human embryonic stem cells (hESC) and during their differentiation is limited, especially regarding histo-blood group AB(O)H antigens. METHODS: Nine different hESC lines, and hESC-derived hepatocyte- and cardiomyocyte-like cells, were blood group ABO genotyped and A/B antigen expression was studied by immunohistochemistry. RESULTS: This study reveals, for the first time, that A and B antigens in hESC were expressed according to the ABO genotype and that the antigens had a different cellular/sub-cellular distribution. In addition, several genotype A hESC lines stained positive with one anti-B antibody. Furthermore, studies of hepatocyte- and cardiomyocyte-like cells of different maturation state, originating from a blood group B hESC line, showed that hepatocyte-like cells expressed B antigens whereas cardiomyocyte-like cells were negative. CONCLUSION: Since clinical stem-cell therapy is likely to be performed with immature progenitor cells, blood group ABO compatibility of donor cells/recipients should be favorable to avoid unnecessary rejection problems caused by ABO incompatibility. The in vitro loss of B antigens in a genotype B hESC line indicates that loss of ABH antigens occurs early during human embryogenesis since these antigens are lacking in adult cardiomyocytes.
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| 32. |
- Nielsen, Susanne, 1969, et al.
(författare)
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Socioeconomic Factors, Secondary Prevention Medication, and Long-Term Survival After Coronary Artery Bypass Grafting: A Population-Based Cohort Study From the SWEDEHEART Registry.
- 2020
-
Ingår i: Journal of the American Heart Association. - 2047-9980. ; 9:5
-
Tidskriftsartikel (refereegranskat)abstract
- Background Low income and short education have been found to be independently associated with inferior survival after coronary artery bypass grafting (CABG), whereas the use of secondary prevention medications is associated with improved survival. We investigated whether underusage of secondary prevention medications contributes to the inferior long-term survival in CABG patients with a low income and short education. Methods and Results Patients who underwent CABG in Sweden between 2006 to 2015 and survived at least 6months after discharge (n=28448) were included in a population-based cohort study. Individual patient data from 5 national registries, including the SWEDEHEART (Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies) registry, covering dispensing of secondary prevention medications (statins, platelet inhibitors, β-blockers, and RAAS inhibitors), socioeconomic factors, patient characteristics, comorbidity, and long-term mortaity were merged. All-cause mortality risk was estimated using multivariable Cox regression models adjusted for patient characteristics, baseline comorbidities, time-updated secondary prevention medications, and socioeconomic status. Long-term mortality was higher in patients with a low income and short education. Statins and platelet inhibitors were dispensed less often to patients with a low income, both at baseline and after 8years. The decline in dispensing over time was steeper for low-income patients. Short education was not associated with reduced dispensing of any secondary prevention medication. Use of statins (adjusted hazard ratio=0.57 [95% CI, 0.53-0.61]), RAAS inhibitors (adjusted hazard ratio=0.78 [0.73-0.84]), and platelet inhibitors (adjusted hazard ratio=0.74 [0.68-0.80]) were associated with reduced long-term mortality irrespective of socioeconomic status. Conclusions Secondary prevention medications are dispensed less often after CABG to patients with low income. Underusage of secondary prevention medications after CABG is associated with increased mortality risk independently of income and extent of education.
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| 33. |
- Nozohoor, Shahab, et al.
(författare)
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ABO blood group does not impact incidence or outcomes of surgery for acute type A aortic dissection
- 2020
-
Ingår i: Scandinavian Cardiovascular Journal. - : Taylor & Francis. - 1401-7431 .- 1651-2006. ; 54:2, s. 124-129
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: To evaluate the distribution and impact of ABO blood groups on postoperative outcomes in patients undergoing surgery for acute type A aortic dissection (ATAAD).Design: A total of 1144 surgical ATAAD patients from eight Nordic centres constituting the Nordic consortium for acute type A aortic dissection (NORCAAD) were analysed. Blood group O patients were compared to non-O subjects. The relative frequency of blood groups was assessed with t-distribution, modified for weighted proportions. Multivariable logistic regression was performed to identify independent predictors of 30-day mortality. Cox regression analyses were performed for assessing independent predictors of late mortality.Results: There was no significant difference in the proportions of blood group O between the study populations in the NORCAAD registry and the background population (40.6 (95% CI 37.7-43.4)% vs 39.0 (95% CI 39.0-39.0)%). ABO blood group was not associated with any significant change in risk of 30-day or late mortality, with the exception of blood group A being an independent predictor of late mortality. Prevalence of postoperative complications was similar between the ABO blood groups.Conclusions: In this large cohort of Nordic ATAAD patients, there were no associations between ABO blood group and surgical incidence or outcomes, including postoperative complications and survival.
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| 34. |
- Nybacka, Mikael, et al.
(författare)
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Project: CASTT - Centre for Automotive Systems Technologies and Testing
- 2007
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Annan publikation (populärvet., debatt m.m.)abstract
- Through the Centre for Automotive Systems Technologies and Testing, Luleå University of Technology aims to first of all support automotive winter testing in Northern Sweden. This means to support the local automotive test entrepreneurs and through them their customers: the car manufacturers and their suppliers. To succeed in this task, the center relies on the university's areas of leading research and most importantly on the cooperation between those areas.
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| 35. |
- Oudin, Anna, et al.
(författare)
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Impact of national holidays and weekends on incidence of acute type A aortic dissection repair
- 2022
-
Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 12:1
-
Tidskriftsartikel (refereegranskat)abstract
- Previous studies have demonstrated that environmental and temporal factors may affect the incidence of acute type A aortic dissection (ATAAD). Here, we aimed to investigate the hypothesis that national holidays and weekends influence the incidence of surgery for ATAAD. For the period 1st of January 2005 until 31st of December 2019, we investigated a hypothesised effect of (country-specific) national holidays and weekends on the frequency of 2995 surgical repairs for ATAAD at 10 Nordic cities included in the Nordic Consortium for Acute Type A Aortic Dissection (NORCAAD) collaboration. Compared to other days, the number of ATAAD repairs were 29% (RR 0.71; 95% CI 0.54–0.94) lower on national holidays and 26% (RR 0.74; 95% CI 0.68–0.82) lower on weekends. As day of week patterns of symptom duration were assessed and the primary analyses were adjusted for period of year, our findings suggest that the reduced surgical incidence on national holidays and weekends does not seem to correspond to seasonal effects or surgery being delayed and performed on regular working days.
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| 36. |
- Oudin Åström, Daniel, et al.
(författare)
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Temperature effects on incidence of surgery for acute type A aortic dissection in the Nordics
- 2022
-
Ingår i: Global health action. - : Informa UK Limited. - 1654-9880 .- 1654-9880 .- 1654-9716. ; 15:1
-
Tidskriftsartikel (refereegranskat)abstract
- We aimed to investigate a hypothesised association between daily mean temperature and the risk of surgery for acute type A aortic dissection (ATAAD). For the period of 1 January 2005 until 31 December 2019, we collected daily data on mean temperatures and date of 2995 operations for ATAAD at 10 Nordic cities included in the Nordic Consortium for Acute Type A Aortic Dissection (NORCAAD) collaboration. Using a two-stage time-series approach, we investigated the association between hot and cold temperatures relative to the optimal temperature and the rate of ATAAD repair in the selected cities. The relative risks (RRs) of cold temperatures (<=-5 degrees C) and hot temperatures (>= 21 degrees C) compared to optimal temperature were 1.47 (95% CI: 0.72-2.99) and 1.43 (95% CI: 0.67-3.08), respectively. In line with previous studies, we observed increased risk at cold and hot temperatures. However, the observed associations were not statistically significant, thus only providing weak evidence of an association.
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| 37. |
- Perman, Jeanna, 1981, et al.
(författare)
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The VLDL receptor promotes lipotoxicity and increases mortality in mice following an acute myocardial infarction.
- 2011
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Ingår i: The Journal of clinical investigation. - : American Society for Clinical Investigation. - 1558-8238 .- 0021-9738. ; 121:7, s. 2625-40
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Tidskriftsartikel (refereegranskat)abstract
- Impaired cardiac function is associated with myocardial triglyceride accumulation, but it is not clear how the lipids accumulate or whether this accumulation is detrimental. Here we show that hypoxia/ischemia-induced accumulation of lipids in HL-1 cardiomyocytes and mouse hearts is dependent on expression of the VLDL receptor (VLDLR). Hypoxia-induced VLDLR expression in HL-1 cells was dependent on HIF-1α through its interaction with a hypoxia-responsive element in the Vldlr promoter, and VLDLR promoted the endocytosis of lipoproteins. Furthermore, VLDLR expression was higher in ischemic compared with nonischemic left ventricles from human hearts and was correlated with the total lipid droplet area in the cardiomyocytes. Importantly, Vldlr-/- mice showed improved survival and decreased infarct area following an induced myocardial infarction. ER stress, which leads to apoptosis, is known to be involved in ischemic heart disease. We found that ischemia-induced ER stress and apoptosis in mouse hearts were reduced in Vldlr-/- mice and in mice treated with antibodies specific for VLDLR. These findings suggest that VLDLR-induced lipid accumulation in the ischemic heart worsens survival by increasing ER stress and apoptosis.
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| 38. |
- Ragnarsson, Sigurdur, et al.
(författare)
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Pacemaker implantation following tricuspid valve annuloplasty.
- 2023
-
Ingår i: JTCVS open. - 2666-2736. ; 16, s. 276-289
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Tidskriftsartikel (refereegranskat)abstract
- Tricuspid annuloplasty is associated with increased risk of atrioventricular block and subsequent implantation of a permanent pacemaker. However, the exact incidence of permanent pacemaker, associated risk factors, and outcomes in this frame remain debated. The aim of the study was to report permanent pacemaker incidence, risk factors, and outcomes after tricuspid annuloplasty from nationwide databases.By using data from multiple Swedish mandatory national registries, all patients (n=1502) who underwent tricuspid annuloplasty in Sweden from 2006 to 2020 were identified. Patients who needed permanent pacemaker within 30days from surgery were compared with those who did not. The cumulative incidence of permanent pacemaker implantation was estimated. A multivariable logistic regression model was fit to identify risk factors of 30-day permanent pacemaker implantation. The association between permanent pacemaker implantation and long-term survival was evaluated with multivariable Cox regression.The 30-day permanent pacemaker rate was 14.2% (214/1502). Patients with permanent pacemakers were older (69.8±10.3years vs 67.5±12.4years, P=.012). Independent risk factors of permanent pacemaker implantation were concomitant mitral valve surgery (odds ratio, 2.07; 95% CI, 1.34-3.27), ablation surgery (odds ratio, 1.59; 95% CI, 1.12-2.23), and surgery performed in a low-volume center (odds ratio, 1.85; 95% CI, 1.17-2.83). Permanent pacemaker implantation was not associated with increased long-term mortality risk (adjusted hazard ratio, 0.74; 95% CI, 0.53-1.03).This nationwide study demonstrated a high risk of permanent pacemaker implantation within 30days of tricuspid annuloplasty. However, patients who needed a permanent pacemaker did not have worse long-term survival, and the cumulative incidence of heart failure and major adverse cardiovascular events was similar to patients who did not receive a permanent pacemaker.
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| 39. |
- Rexius, Helena, 1967, et al.
(författare)
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A simple score to assess mortality risk in patients waiting for coronary artery bypass grafting
- 2006
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Ingår i: Ann Thorac Surg. - : Elsevier BV. - 1552-6259 .- 0003-4975. ; 81:2, s. 577-82
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Independent risk factors for death in patients waiting for elective coronary artery bypass surgery have previously been identified. A prioritization where these factors are considered may potentially reduce waiting list mortality. A simple score based on the risk factors was constructed and validated. METHODS: A scoring system based on risk factors in 5,864 consecutive patients operated from 1995 to 1999 was constructed. The following factors were included in the score: unstable angina (3 points [p]), left main stenosis (2p), concomitant aortic valve disease (2p), operative risk (0-2p), left ventricular ejection fraction (0-2p), and male gender (1p). The score was retrospectively validated in 5,167 new patients operated from 1999 to 2003. Based on the sum of risk score points, the patients were divided into three risk groups: low risk (0-2p), intermediate risk (3-5p) and high risk (> or = 6p). The risk groups were related to waiting list mortality and clinical priority (imperative, urgent, and routine). RESULTS: Median waiting time was 33 days. Forty-two patients (0.8%) died while waiting for surgery (5.2 deaths/100 waiting years). Of the patients, 2,406 (47%) were low risk, 1,990 (38%) intermediate risk, and 771 (15%) high risk. Mortality incidence in the high-risk group was fivefold higher than in the intermediate group and 25-fold higher than in the low-risk group (32, 7, and 1.3 deaths/100 waiting years, respectively, p < 0.001 between all groups). Twenty-three percent of the patients in the high-risk group had not been given imperative clinical priority. CONCLUSIONS: The score system identifies patients with increased risk of death while waiting for coronary artery bypass grafting. The score may be used to facilitate and improve the prioritization process.
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| 40. |
- Singh, Sukhi, 1990, et al.
(författare)
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Adrenaline enhances in vitro platelet activation and aggregation in blood samples from ticagrelor-treated patients
- 2018
-
Ingår i: Research and Practice in Thrombosis and Haemostasis. - : John Wiley & Sons. - 2475-0379. ; 2:4, s. 718-725
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Tidskriftsartikel (refereegranskat)abstract
- Background: Temporarily improved platelet reactivity may reduce the bleeding in patients on antiplatelet therapy who have ongoing bleeding or who are in need of acute surgery. Adrenaline can bind to adrenergic alpha(2A)-receptors on platelets and potentially enhance platelet reactivity.Objective: To assess if adrenaline can improve adenosine diphosphate (ADP)-induced platelet aggregation and activation in blood samples from patients on dual antiplatelet therapy with acetylsalicylic acid (ASA) and the ADP-receptor antagonist ticagrelor.Methods: Blood samples were collected from a total of forty acute coronary syndrome patients on dual antiplatelet therapy with ASA and ticagrelor. ADP-induced platelet aggregation (by impedance aggregometry) and activation (by flow cytometry) were assessed before and after supplementation with adrenaline and/or platelet concentrate.Results: Adrenaline supplementation (770 nmol L-1) increased median ADP-induced aggregation from 15 (25-75th percentiles: 10-20) to 26 (18-38) aggregation units. The effect was independent of concomitant platelet supplementation. Adrenaline also increased ADP-induced platelet activation: from 40% (36-54%) to 83% (74-88%) platelets with active fibrinogen receptor (binding PAC-1) and from 13% (7-21%) to 35% (18-50%) P-selectin-expressing platelets.Conclusions: Adrenaline potentiated ADP-induced platelet aggregation and activation in blood samples from ticagrelor-treated patients. Adrenaline infusion may be a new method to enhance platelet function in ticagrelor-treated patients who are in need of acute surgery or have ongoing bleeding. In vivo studies are needed to confirm the present results.
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| 41. |
- Spross, Johan, 1986-
(författare)
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A Critical Review of the Observational Method
- 2014
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Building a sustainable structure in soil or rock that satisfies all predefined technical requirements implies choosing a rational and effective construction method. An important aspect is how the performance of the structure is verified. For cases when the geotechnical behaviour is hard to predict, the existing design code for geotechnical structures, Eurocode 7, suggests the so-called “observational method” to verify that the performance is acceptable. The basic principle of the method is to accept predefined changes in the design during construction, in order to accommodate the actual ground conditions, if the current design is found unsuitable. Even though this in theory should ensure an effective design solution, formal application of the observational method is rare. It is therefore not clear which prerequisites and circumstances that must be present for the observational method to be applicable and be the more suitable method.This licentiate thesis gives a critical review of the observational method, based on, and therefore limited by, the outcome of the performed case studies. The aim is to identify and highlight the crucial aspects that make the observational method difficult to apply, thereby providing a basis for research towards a more applicable definition of the method. The main topics of discussion are (1) the apparent contradiction between the preference for advanced probabilistic calculation methods to solve complex design problems and sound, qualitative engineering judgement, (2) the limitations of measurement data in assessing the safety of a structure, (3) the fact that currently, no safety margin is required for the completed structure when the observational method is applied, and (4) the rigidity of the current definition of the observational method and the implications of deviations from its principles.Based on the review, it is argued that the observational method can be improved by linking it to a probabilistic framework. To be applicable, the method should be supported by guidelines that explain and exemplify how to make the best use of it. The engineering judgement is however not lost; no matter how elaborate probabilistic methods are used, sound judgement is still needed to define the problem correctly. How to define such a probabilistic framework is an urgent topic for future research, because this also addresses the concerns regarding safety that is raised in the other topics of discussion.
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| 42. |
- Vingbäck, Johan, et al.
(författare)
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Development of a drive cycle simulation model for hybrid powertrains
- 2012
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Ingår i: Proceedings of the ASME Design Engineering Technical Conference. - New York : American Society of Mechanical Engineers. - 9780791845059 ; , s. 581-585
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Konferensbidrag (refereegranskat)abstract
- In this paper a modular numerical simulation model for hybrid powertrains is presented. The simulation model is based on common design parameters and measurements for fuel efficiency and vehicle performance. Implemented in Simulink, the main model is expandable to combine the strengths of different types of simulation tools. As the design process proceeds, parts of the model can gradually be replaced with instances containing one or more subsystem modelled in the appropriate tool, including CAD, FEA and MBD, incrementally increasing the accuracy of the model of the overall system yet keeping the simulation time reasonable. Subsystems can be replaced to support hardware input and/or output, resulting in a so-called hardware-in-the-loop simulation. The presented system has shown to be modular as all the components contain their physical properties and can be modified, replaced or reorganized without the modification of any other subsystem. The simulation model of the powertrain is easily modified in order to allow the simulation of multiple designs with the same components. The systeam also has the same information flow as would be observed in a physical powertrain.
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| 43. |
- Vingbäck, Johan, et al.
(författare)
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Evaluating ride comfort for wheelchair passengers utilizing a motionbase simulator.
- 2014
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Ingår i: ASME 2014 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. - New York : American Society of Mechanical Engineers. - 9780791846346
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Konferensbidrag (refereegranskat)abstract
- Ride comfort is an important aspect of any passenger vehicle. The challenge is to provide a comfortable, yet safe, ride for the driver and the passengers and there is often a trade-off between ride comfort and safety performance.In the case of small wheelchair-accessible vehicles the challenge increases. The weight of a wheelchair with person may span from 50 kg to 500 kg, which means that the suspension must be tuned to have a broad working range. Also, a wheelchair-accessible vehicle has many restrictions on design space and tuning possibilities due to, e.g., the space needed for the wheelchair passenger to get in and out of the vehicle. Hence, there is an additional need to evalute ride comfort and performance before the vehicle is built in order to find the optimal design. Traditionally, this is done by computer simulations of vehicle handling complemented with testing followed by chassis tuning prior to production. However, some performance parameters regarding comfort, especially in the case of wheelchair passengers, are still not well investigated and documented, and there is a need to subjectively evaluate the ride comfort in early design phases.In this paper we investigate the use of a motionbase simulator as a platform for evaluating ride comfort with different suspension setups. We are using a reversible sleeve air suspension bellow equipped with an adaptor cylinder giving the spring characteristics. The characteristics of four different adaptors have been measured in a universal test machine. The force-compression characteristics are imported into the simulation. The simulation model used is a half-car, two-degree of freedom producing bounce and pitch movement data for either the driver or the passenger positions. The data from the simulations are used as input to a motionbase simulator for subjective assessment of the ride comfort.The primary results indicate that a motionbase simulator can be a useful tool when designing/developing suspension systems. Also, the results indicate that a motionbase simulator is useful for investigation of comfort parameters in order to determine objective assessment of subjective parameters.
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| 44. |
- Vingbäck, Johan, et al.
(författare)
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Obstacle identification through fast vector analysis
- 2016
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Ingår i: ASME 2016 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. - New York : American Society of Mechanical Engineers. - 9780791850138
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Konferensbidrag (refereegranskat)abstract
- During road travel, obstacles can impede productivity or durability for many different vehicles and render discomfort or injuries for the people within. Using remote sensing techniques, information from the surroundings can be acquired and analysed to identify obstacles ahead. The subsequent analysis can create a decision support for how the vehicle or driver should act upon encountered obstacles, through either autonomous control, guidance to the driver or a combination of both. In this paper, an experimental setup was created to mimic an obstacle in the shape of a speed bump on a flat road. An RGB-D camera was used to acquire information while travelling towards the speed bump. Afterwards, the acquired information was analysed by an estimation of the normal vector for each point in a 2D depth map. The resulting data from the experiments had sufficient resolution, speed and quality to retrieve proper identify obstacles or targets indoors with an accuracy of 2%. Obstacles were measured and identified in less than 20~ms where processing time mainly comprised data transfer from the USB-bus. The obstacle identification can be used to e.g. actively control the vehicle suspension, send feedback to the driver about obstacles ahead or optimise speed and direction for autonomous vehicles.
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| 45. |
- Wallgren, Sara, et al.
(författare)
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A single sequential snake saphenous vein graft versus separate left and right vein grafts in coronary artery bypass surgery: a population-based cohort study from the SWEDEHEART registry
- 2019
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Ingår i: European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery. - : Oxford University Press (OUP). - 1873-734X. ; 56:3, s. 518-525
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Tidskriftsartikel (refereegranskat)abstract
- Our goal was to compare short- and midterm outcomes after coronary artery bypass grafting (CABG) using 2 different revascularization strategies.A total of 6895 patients were included who had CABG in Sweden from 2009 to 2015 using the left internal mammary artery to the left anterior descending artery and either a single sequential saphenous vein graft connecting the left and right coronary territories to the aorta (snake graft, n=2122) or separate vein grafts to both territories (n=4773). Data were obtained from the Swedish Web System for Enhancement of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies (SWEDEHEART) and the Swedish Patient Registry. The groups were compared using adjusted logistic regression for short-term (30-day) and Cox regression and flexible parametric survival models for midterm outcomes. Primary outcome was a composite of all-cause mortality, myocardial infarction (MI), reangiography and new revascularization. The median follow-up time was 35months.At 30days, the incidences of the composite end point [odds ratio (OR) 1.31, 95% confidence interval (CI) 1.03-1.68; P=0.03] and reangiography (OR 1.51, 95% CI 1.07-2.14; P=0.02) were higher in the snake group. There was also a trend towards higher mortality (OR 1.47, 95% CI 0.97-2.22; P=0.07). The event rates during the complete follow-up period were 6.5 (5.9-7.2) and 5.7 (5.3-6.1) per 100 person-years for the snake group and the separate vein group, respectively. At the midterm follow-up, no significant difference between the groups could be shown for the composite end point [hazard ratio (HR) 1.08, 95% CI 0.95-1.22; P=0.24], mortality (HR 0.95, 95% CI 0.79-1.14; P=0.56), MI (HR 1.11, 95% CI 0.88-1.41; P=0.39) or new revascularization (HR 1.19, 95% CI 0.94-1.50; P=0.15), whereas reangiography remained more common in the snake group (HR 1.25, 95% CI 1.05-1.48; P=0.01).Snake grafts were associated with a higher rate of early postoperative complications, possibly reflecting a more demanding surgical technique, whereas midterm outcomes were comparable. Based on these data, one strategy cannot be recommended over the other.
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| 46. |
- Westerberg, Martin, et al.
(författare)
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Hemodynamic effects of cardiotomy suction blood.
- 2006
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Ingår i: The Journal of thoracic and cardiovascular surgery. - : Elsevier BV. - 1097-685X .- 0022-5223. ; 131:6, s. 1352-7
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Cardiac surgery induces a systemic inflammatory activation, which in severe cases is associated with peripheral vasodilation and hypotension. Cardiotomy suction blood contains high levels of inflammatory mediators, but the effect of cardiotomy suction blood on the vasculture is unknown. We investigated the effect of cardiotomy suction blood on systemic vascular resistance in vivo and whether cell-saver processing of suction blood affects the vascular response. METHODS: Twenty-five patients undergoing coronary surgery (mean age, 68 +/- 2 years; 80% men) were included in a prospective randomized study. The patients were randomized to retransfusion of cell-saver processed (n = 13) or cell-saver unprocessed (n = 12) suction blood during full cardiopulmonary bypass. Mean arterial blood pressure was continuously registered during retransfusion, and systemic vascular resistance was calculated. Plasma concentrations of tumor necrosis factor alpha, interleukin 6, and complement factor C3a were measured in suction blood. RESULTS: Retransfusion of cardiotomy suction blood induced a transient reduction in systemic vascular resistance in all patients. The peak reduction was significantly less pronounced in the group receiving cell-saver processed blood (-12% +/- 2% vs -28% +/- 3%, P = .001). There was a significant correlation between tumor necrosis factor alpha concentration in retransfused cardiotomy suction blood and peak reduction of systemic vascular resistance (r = 0.60, P = .002). CONCLUSIONS: The results suggest cardiotomy suction blood is vasoactive and might influence vascular resistance and blood pressure during cardiac surgery. The observed vasodilation is proportional to the inflammatory activation of suction blood and can be reduced by processing suction blood with a cell-saving device before retransfusion.
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| 47. |
- Zindovic, Igor, et al.
(författare)
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Malperfusion in acute type A aortic dissection : An update from the Nordic Consortium for Acute Type A Aortic Dissection
- 2019
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Ingår i: Journal of Thoracic and Cardiovascular Surgery. - : Elsevier. - 0022-5223 .- 1097-685X. ; 157:4, s. 1324-1333
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To evaluate the effect of preoperative malperfusion on 30-day and late mortality and postoperative complications using data from the Nordic Consortium for Acute Type A Aortic Dissection (ATAAD) registry.Methods: We studied 1159 patients who underwent ATAAD surgery between January 2005 and December 2014 at 8 Nordic centers. Multivariable logistic and Cox regression analyses were performed to identify independent predictors of 30-day and late mortality.Results: Preoperative malperfusion was identified in 381 of 1159 patients (33%) who underwent ATAAD surgery. Thirty-day mortality was 28.9% in patients with preoperative malperfusion and 12.1% in those without. Independent predictors of 30-day mortality included any malperfusion (odds ratio, 2.76; 95% confidence interval [CI], 1.94-3.93), cardiac malperfusion (odds ratio, 2.37; 95% CI, 1.34-4.17), renal malperfusion (odds ratio, 2.38; 95% CI, 1.23-4.61) and peripheral malperfusion (odds ratio, 1.95; 95% CI, 1.26-3.01). Any malperfusion (hazard ratio, 1.72; 95% CI, 1.21-2.43), cardiac malperfusion (hazard ratio, 1.89; 95% CI, 1.24-2.87) and gastrointestinal malperfusion (hazard ratio, 2.25; 95% CI, 1.18-4.26) were predictors of late mortality. Malperfusion was associated with significantly poorer survival at 1, 3, and 5 years (95.0% +/-0.9% vs 88.7% +/-1.9%, 90.1% +/-1.3% vs 84.0% +/-2.4%, and 85.4% +/-1.7% vs 80.8% +/-2.7%; log rank P = .009).Conclusions: Malperfusion has a significant influence on early and late outcomes in ATAAD surgery. Management of preoperative malperfusion remains a major challenge in reducing mortality associated with surgical treatment of ATAAD.
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