| 1. |
- Aleman, Soo, et al.
(författare)
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A Risk for Hepatocellular Carcinoma Persists Long-term After Sustained Virologic Response in Patients With Hepatitis C-Associated Liver Cirrhosis
- 2013
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Ingår i: Clinical Infectious Diseases. - : Oxford University Press (OUP). - 1537-6591 .- 1058-4838. ; 57:2, s. 230-236
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Tidskriftsartikel (refereegranskat)abstract
- Background. The long-term effect of sustained virologic response (SVR) to antiviral therapy on the risk of developing hepatocellular carcinoma (HCC), liver complications, liver-related death, and overall death in hepatitis C virus (HCV)-infected patients with liver cirrhosis is not fully known. Methods. These risks were evaluated during long-term follow-up in 351 patients with HCV-related cirrhosis. One hundred ten patients with SVR, 193 with non-SVR, and 48 who were untreated were included in a multicenter cohort that was initiated in 2001 and prospectively followed up for a mean of 5.3 (SD, 2.8) years. Complementary follow-up data from national registries were used to minimize the loss of patients during follow-up. Results. Six patients with SVR developed HCC at 0.04, 0.64, 2.4, 7.4, 7.4, and 7.6 years, respectively, after achieving SVR. The incidences of HCC, any liver complication, liver-related death, and overall death per 100 person-years were significantly lower in SVR time with 1.0, 0.9, 0.7, and 1.9, compared to 2.3, 3.2, 3.0, and 4.1 in non-SVR and 4.0, 4.9, 4.5, and 5.1 in untreated time. The long-term consequences did not decline significantly after >3 years versus during the first 3 years of follow-up. Conclusions. The risk for HCC, liver decompensation, and death in patients with liver cirrhosis related to HCV was markedly reduced after SVR, but a long-term risk of developing HCC remains for up to 8 years. Cirrhotic patients with HCV who achieve SVR should therefore maintain long-term surveillance for HCC. Future studies aimed to better identify those with remaining long-term risk for HCC are needed.
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| 2. |
- Andersson, Jim, et al.
(författare)
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Multiscale Reactor Network Simulation of an Entrained Flow Biomass Gasifier : Model Description and Validation
- 2017
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Ingår i: Energy Technology. - : Wiley. - 2194-4288. ; 5, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes the development of a multiscale equivalent reactor network model for pressurized entrained flow biomass gasification to quantify the effect of operational parameters on the gasification process, including carbon conversion, cold gas efficiency, and syngas methane content. The model, implemented in the commercial software Aspen Plus, includes chemical kinetics as well as heat and mass transfer. Characteristic aspects of the model are the multiscale effect caused by the combination of transport phenomena at particle scale during heating, pyrolysis, and char burnout, as well as the effect of macroscopic gas flow, including gas recirculation. A validation using experimental data from a pilot-scale process shows that the model can provide accurate estimations of carbon conversion, concentrations of main syngas components, and cold gas efficiency over a wide range of oxygen-to-biomass ratios and reactor loads. The syngas methane content was most difficult to estimate accurately owing to the unavailability of accurate kinetic parameters for steam methane reforming.
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| 3. |
- Bergvall, Niklas, et al.
(författare)
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Corefining of Fast Pyrolysis Bio-Oil with Vacuum Residue and Vacuum Gas Oil in a Continuous Slurry Hydrocracking Process
- 2020
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Ingår i: Energy & Fuels. - : American Chemical Society. - 0887-0624 .- 1520-5029. ; 34:7, s. 8452-8465
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Tidskriftsartikel (refereegranskat)abstract
- Integration of renewable raw materials in existing refineries is most likely the shortest way for the successful, large-scale introduction of biofuels in the transport sector in the short term and medium term. One possible renewable raw material for this application is fast pyrolysis bio-oil (FPBO), which in this study has been coprocessed (at 0 and 20 wt %) with vacuum residue (VR, 50 wt %) and vacuum gas oil (VGO, balance) in a continuous, as well as a semibatch, slurry hydrocracking process. Experiments both with and without FPBO were performed at 450°C and 150 bar with a continuous hydrogen flow through the reactor. Oil-soluble molybdenum hexacarbonyl and molybdenum 2-ethylhexanoate were used as catalyst precursors, to be sulfided in situ. The continuous trials resulted in reactor walls completely free of coking, and they resulted in a low overall coke yield (about 1 wt %). The hydrodeoxygenation reached almost 92%, and the total acid number was reduced by nearly 99% in the FPBO experiment A mass balance of the renewable carbon from FPBO, based on the performed experiments, showed that the fossil CO2 emissions can be lowered by 1.35 kg per kg of processed FPBO if all renewable carbon in gaseous and liquid hydrocarbons is used to replace its fossil counterparts, and all methane formed from FPBO is used to produce hydrogen. Semibatch experiments gave less successful results when upgrading FPBO-containing feedstock, with a high coke yield (8 wt %) as well as a high gas yield (24 wt %). The results of this study demonstrate that FPBO can be successfully coprocessed with heavy fossil oils in a continuous slurry hydrocracking process without neg. affecting the processing of the fossil components of the feed and that a continuous process is preferred over batch or semibatch processes when studying coprocessing of bio-oils.
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| 4. |
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| 5. |
- Carlborg, Markus, et al.
(författare)
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Exposure of refractory materials during high-temperature gasification of a woody biomass and peat mixture
- 2018
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Ingår i: Journal of the European Ceramic Society. - : Elsevier BV. - 0955-2219 .- 1873-619X. ; 38:2, s. 777-787
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Tidskriftsartikel (refereegranskat)abstract
- Finding resilient refractory materials for slagging gasification systems have the potential to reduce costs and improve the overall plant availability by extending the service life. In this study, different refractory materials were evaluated under slagging gasification conditions. Refractory probes were continuously exposed for up to 27 h in an atmospheric, oxygen blown, entrained flow gasifier fired with a mixture of bark and peat powder. Slag infiltration depth and microstructure were studied using SEM EDS. Crystalline phases were identified with powder XRD. Increased levels of Al, originating from refractory materials, were seen in all slags. The fused cast materials were least affected, even though dissolution and slag penetration could still be observed. Thermodynamic equilibrium calculations were done for mixtures of refractory and slag, from which phase assemblages were predicted and viscosities for the liquid parts were estimated. © 2017 Elsevier Ltd
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| 6. |
- Carlsson, Per, et al.
(författare)
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Slag Formation During Oxygen Blown Entrained-Flow Gasification of Stem Wood
- 2014
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Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 28:11, s. 6941-6952
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Tidskriftsartikel (refereegranskat)abstract
- Stem wood powders were fired in a mullite-lined pilot-scale oxygen-blown pressurized entrained-flow gasifier. During repeated campaigns involving increases in fuel load and process temperature, slag formations that eventuated in the blockage of the gasifier outlet were observed. These slags were retrieved for visual and chemical characterization. It was found that the slags had very high contents of Al and, in particular, high Al/Si ratios that suggest likely dissolution of the mullite-based refractory of the gasifier lining due to interactions with the fuel ash. Possible causes for the slag formation and behavior are proposed, and practical implications for the design of future stem wood entrained-flow gasifiers are also discussed
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| 7. |
- Danielsson Borssén, Åsa, et al.
(författare)
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Epidemiology and causes of death in a Swedish cohort of patients with autoimmune hepatitis
- 2017
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 52:9, s. 1022-1028
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Tidskriftsartikel (refereegranskat)abstract
- Background: Epidemiological studies of autoimmune hepatitis (AIH) show varying figures on prevalence and incidence, and data on the long-term prognosis are scarce.Objective To investigate the epidemiology, long-term prognosis and causes of death in a Swedish AIH cohort.Material and methods: Data collected from 634 AIH patients were matched to the Cause of Death Registry, and survival analyses were made. Prevalence and incidence were calculated for university hospitals with full coverage of cases and compared to the County of Vasterbotten in Northern Sweden.Results: AIH point prevalence was 17.3/100,000 inhabitants in 2009, and the yearly incidence 1990-2009 was 1.2/100,000 inhabitants and year. The time between diagnosis and end of follow-up, liver transplantation or death was in median 11.3 years (range 0-51.5 years). Men were diagnosed earlier (p<.001) and died younger than women (p=.002). No gender differences were found concerning transplant-free, overall survival and liver-related death. Cirrhosis at diagnosis was linked to an inferior survival (p<.001). Liver-related death was the most common cause of death (32.7%). The relative survival started to diverge from the general population 4 years after diagnosis but a distinct decline was not observed until after more than 10 years.Conclusions: Long-term survival was reduced in patients with AIH. No gender difference regarding prognosis was seen but men died younger, probably as a result of earlier onset of disease. Cirrhosis at diagnosis was a risk factor for poor prognosis and the overall risk of liver-related death was increased.
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| 8. |
- Danielsson Borssén, Åsa, et al.
(författare)
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Epidemiology and causes of death in a Swedish cohort of patients with autoimmune hepatitis
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background Epidemiological studies of autoimmune hepatitis (AIH) show varying figures on prevalence and incidence, and data on the long-term prognosis are scarce.Objective To investigate the epidemiology, long-term prognosis and causes of death in a Swedish AIH cohort.Material and methods Data collected from 634 AIH patients were matched to the Cause of Death Registry, and survival analyses were made. Prevalence and incidence were calculated for University Hospitals with full coverage of cases and compared to the County of Västerbotten in Northern Sweden.Results AIH point prevalence was 17.3/100 000 inhabitants in 2009, and the yearly incidence 1990-2009 was 1.2/100 000 inhabitants and year. The time between diagnosis and end of follow-up, liver transplantation or death was in median 11.3 years (range 0-51.5 years). Men were diagnosed earlier (p<0.001) and died younger than women (p=0.002). No gender differences were found concerning transplant-free, overall survival and liver-related death. Cirrhosis at diagnosis was linked to an inferior survival (p<0.001). Liver-related death was the most common cause of death (32.7%). The relative survival started to diverge from the general population 4 years after diagnosis but a distinct decline was not observed until after more than 10 years. Conclusions Long-term survival was reduced in patients with AIH. No gender difference regarding prognosis was seen but men died younger, probably as a result of earlier onset of disease. Cirrhosis at diagnosis was a risk factor for poor prognosis and the overall risk of liver-related death was increased.
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| 9. |
- Danielsson Borssén, Åsa, 1977-, et al.
(författare)
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Histological improvement of liver fibrosis in well-treated patients with autoimmune hepatitis : A cohort study
- 2017
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Ingår i: Medicine. - : Lippincott Williams & Wilkins. - 0025-7974 .- 1536-5964. ; 96:34
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Tidskriftsartikel (refereegranskat)abstract
- Autoimmune hepatitis (AIH) is a chronic autoimmune liver disease that if left untreated may lead to the development of cirrhosis. Previous studies on AIH patients have suggested that fibrosis and even cirrhosis can be reversed by medical treatment. The aim of this study was to evaluate the efficacy of medical treatment for protection of developing fibrosis and cirrhosis.A total of 258 liver biopsies from 101 patients (72 women, 29 men) were analyzed by a single pathologist and classified according to the Ishak grading (inflammation) and staging (fibrosis) system. Liver histology was stratified according to the temporal changes of fibrosis stage (increased, decreased, or stable), and groups were compared.Complete or partial response to medical treatment was 94.9%. Reduction of fibrosis stage from the first to the last biopsy was seen in 63 patients (62.4%). We found an association between a reduction in the fibrosis stage and continuous glucocorticoid medication, as well as lowered scores of inflammation at last biopsy. Twenty-one patients had cirrhosis (Ishak stage 6) at least in one of the previous biopsies, but only 5 patients at the last biopsy.Histological improvement is common in AIH patients that respond to medical treatment, and a reduction or stabilization of fibrosis stage occurs in about 2/3 of such patients.
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| 10. |
- Eriksson, D., et al.
(författare)
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Characterization of Scots pine stump-root biomass as feed-stock for gasification
- 2012
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Ingår i: Bioresource Technology. - : Elsevier BV. - 0960-8524 .- 1873-2976. ; 104, s. 729-736
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Tidskriftsartikel (refereegranskat)abstract
- The main objective was to explore the potential for gasifying Scots pine stump-root biomass (SRB). Washed thin roots, coarse roots, stump heartwood and stump sapwood were characterized (solid wood, milling and powder characteristics) before and during industrial processing. Non-slagging gasification of the SRB fuels and a reference stem wood was successful, and the gasification parameters (synthesis gas and bottom ash characteristics) were similar. However, the heartwood fuel had high levels of extractives (≈19%) compared to the other fuels (2-8%) and thereby ≈16% higher energy contents but caused disturbances during milling, storage, feeding and gasification. SRB fuels could be sorted automatically according to their extractives and moisture contents using near-infrared spectroscopy, and their amounts and quality in forests can be predicted using routinely collected stand data, biomass functions and drill core analyses. Thus, SRB gasification has great potential and the proposed characterizations exploit it. © 2011 Elsevier Ltd.
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