| 1. |
- Fehrman-Ekholm, Ingela, 1947, et al.
(författare)
-
Incidence of end-stage renal disease among live kidney donors.
- 2006
-
Ingår i: Transplantation. - : Ovid Technologies (Wolters Kluwer Health). - 0041-1337. ; 82:12, s. 1646-8
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The increasing use of living kidney donors requires knowledge about long-term effects, especially number and causes of donors with end-stage renal disease (ESRD). METHODS: A retrospective data analysis of 1,112 consecutive living kidney donors who underwent nephrectomy from 1965 until 2005 at Sahlgrenska University Hospital. Case reports were sought with help from nephrologists in the region and data from Swedish Registry of Active Uremic Treatment (SRAU). RESULTS: The number of cases with end stage kidney failure among living kidney donors was 6/1112, that is 0.5%. The donors had reached ESRD during the years 2001-2006, that means 36-41 years after start of the living donor program. The donors were 45-89 years old, median 77 years, and five of six were males. Time since donation was 14-27 years, median 20 years, for the donors developing ESRD. The diagnoses were nephrosclerosis (4 cases), postrenal failure (1 case), and renal carcinoma (1 case). The expected incidence for development of ESRD according to incidence in the general population would have been two donors but we found six. However, considering the high age of the donors in this follow up, the age-matched incidence is calculated to be closer to six donors due to higher incidence in the aged. CONCLUSION: In all 0.5% of the donors developed ESRD. Due to high age of the uremic donors, there seems to be no increased incidence.
|
|
| 2. |
- Gustafsson, Bengt I., 1955, et al.
(författare)
-
Retransplantation of the liver.
- 2006
-
Ingår i: Transplantation proceedings. - : Elsevier BV. - 0041-1345. ; 38:5, s. 1438-9
-
Tidskriftsartikel (refereegranskat)abstract
- Retransplantation (re-TX) is the only available therapy for irreversible liver graft dysfunction. The outcome of a second procedure depends upon several factors, some of which are not defined at the time of the decision to retransplant. This study is an analysis of all re-TX of the liver performed at our unit between January 1995 and January 2004. Among the 474 liver TX were 55 (11.6%) re-TX in 47 patients. We studied (1) diagnosis at first TX; (2) indication for re-TX and time lapse; (3) donor age and cold ischemia time (CIT); (4) duration of operation, peroperative bleeding, and complications; (5) ICU and ward periods; and (6) patient and graft survivals. Patients who underwent re-TX did not differ from those transplanted once with regard to age, gender, or diagnosis. The indications for re-TX were roughly one-third biliary tract complications/chronic rejection, one-third hepatic artery thrombosis, and one-third others, including primary nonfunction, acute rejection, portal vein thrombosis, sepsis, and B/C hepatitis. The re-TX were "urgent" in 29 and "elective" in 26 cases. Complications were common; about half of the patients were reoperated due to bleeding or biliary problems. To date (May 2004), 15 patients have died (12 "urgent" and 3 "elective"), of whom 5 had well functioning grafts. In summary, liver re-TX is a complicated procedure associated with significant mortality and morbidity, but considering that the actual patient group has a poor prognosis without re-TX, the results are nevertheless encouraging.
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Lindnér, Per, 1956, et al.
(författare)
-
Extended right-sided liver resection for colorectal liver metastases--impact of percutaneous portal venous embolisation
- 2006
-
Ingår i: European journal of surgical oncology. - 0748-7983. ; 32:3, s. 292-6
-
Tidskriftsartikel (refereegranskat)abstract
- AIM: To compare the outcome after extended right liver lobe resection (ERL) for patients with liver metastases from colorectal cancer with preceding portal vein embolisation (PVE) with a non-PVE-group. METHODS: Nineteen patients underwent ERL (resection of segment 4-8) for colorectal liver metastases after PVE. They were compared with 21 patients that underwent an ERL without embolisation. A comparison was made with 84 patients undergoing right lobe liver resection during the same time period. Survival, post-operative morbidity and mortality were recorded and the volume of the future remnant liver (FRL) was measured with CT. RESULTS: There were major complications in 1/19 patients in the PVE-group and in 6/21 in the non-PVE-group (p=0.04). No post-operative deaths were observed in the PVE-group, compared to three deaths in the non-PVE-group (p=0.09). The median survival in the PVE-group was 32 months, which did not differ from the non-PVE-group. In 21% of the patients that underwent PVE, progression occurred during the time between embolisation and surgery. There was no difference in survival for patients that underwent PVE followed by ERL, compared to patients that underwent standard right lobe liver resection. CONCLUSION: The survival of patients after ERL is comparable with patients that undergo standard right lobe resection and have less liver tumour.
|
|
| 6. |
- Lyckeskog, Huyen, 1985, et al.
(författare)
-
Catalytic depolymerisation and conversion of Kraft lignin into liquid products using near-critical water
- 2014
-
Ingår i: Journal of Supercritical Fluids. - : Elsevier BV. - 0896-8446. ; 86, s. 67-75
-
Tidskriftsartikel (refereegranskat)abstract
- A high-pressure pilot plant was developed to study the conversion of LignoBoost Kraft lignin into bio-oil and chemicals in near-critical water (350◦C, 25 MPa). The conversion takes place in a continuous fixed-bed catalytic reactor (500 cm3) filled with ZrO2 pellets. Lignin (mass fraction of approximately 5.5%) is dispersed in an aqueous solution containing K2CO3(from 0.4% to 2.2%) and phenol (approximately 4.1%).The feed flow rate is 1 kg/h (reactor residence time 11 min) and the reaction mixture is recirculated internally at a rate of approximately 10 kg/h. The products consist of an aqueous phase, containing phenolic chemicals, and a bio-oil, showing an increased heat value (32 MJ/kg) with respect to the lignin feed. The 1-ring aromatic compounds produced in the process are mainly anisoles, alkylphenols, guaiacols and catechols: their overall yield increases from 17% to 27% (dry lignin basis) as K2CO3 is increased.
|
|
| 7. |
- Lyckeskog, Huyen, 1985, et al.
(författare)
-
Storage Stability of Bio-oils Derived from the Catalytic Conversion of Softwood Kraft Lignin in Subcritical Water
- 2016
-
Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 1520-5029 .- 0887-0624. ; 30:4, s. 3097-3106
-
Tidskriftsartikel (refereegranskat)abstract
- The stability of lignin-derived bio-oil obtained from a continuous process [base (K2CO3)-catalyzed, using phenol as a capping agent] under subcritical conditions of water (25 MPa, 290-370 degrees C) was investigated. The lignin-derived bio-oil obtained was stored at ambient temperature for 2 years. Our results show that the base concentration in the feed solution affects the stability of this lignin-derived bio-oil during its long-term storage. It was found that, at low base concentrations (i.e., 0.4%-1.0%), the yields of all lignin-derived bio-oil fractions were relatively stable. At high base concentrations (i.e., 1.6%-2.2%), however, the yield of high-molecular-weight (high-Mw) structures increased and that of low-molecular-weight (low-Mw) structures decreased after storage. This indicated that the low-Mw materials had been polymerized to form high-Mw materials. In addition, it was found that the yield of gas chromatography-mass spectrometry (GC-MS)-identified compounds (excluding phenol) in this lignin-derived bio-oil decreased from 15% to 11%. This is probably due to the presence of solids in these lignin derived bio-oils, which promotes the catalytic polymerization reactions, suggesting that it is beneficial to remove the solids from this lignin-derived bio-oil in order to enhance its stability. Compared to the results obtained from bio-oil derived from biomass pyrolysis, our results show that bio-oil derived from the conversion of lignin in subcritical water has better chemical stability during long-term storage.
|
|
| 8. |
|
|
| 9. |
- Olausson, Deborah, et al.
(författare)
-
Burial in the Swedish-Norwegian Battle Axe Culture : questioning the myth of homogeneity
- 2015
-
Ingår i: Neolithic Diversities : Perspectives from a conference in Lund, Sweden. - 0065-0994. - 9789189578609 ; , s. 98-106
-
Bokkapitel (refereegranskat)abstract
- Since its publication in 1962, Mats P. Malmer’s book Jungneolithische Studien has heavily influenced subsequent work on the Swedish-Norwegian Battle Axe Culture. Malmer characterized burial customs as strictly regulated and conservative. Recent archaeological activity in the province of Scania, southern Sweden, provides us with an augmented empirical basis for testing Malmer’s conclusions. In addition, osteological analyses give us new information on e.g. age and sex of buried individuals. The aim of the article is to re-examine Malmer’s tenants, using both his data and new data available to us, emphasizing variability rather than similarity. While the overall picture of homogeneity painted by Malmer remains, it is also apparent that the rigid strictures he emphasized did not fully apply.
|
|
| 10. |
|
|
| 11. |
- Olausson, Michael, 1956, et al.
(författare)
-
Adjuvant treatment with ursodeoxycholic acid prevents acute rejection in rats receiving heart allografts.
- 1992
-
Ingår i: Transplant international : official journal of the European Society for Organ Transplantation. - 0934-0874. ; 5 Suppl 1
-
Tidskriftsartikel (refereegranskat)abstract
- Adjuvant treatment with ursodeoxycholic acid (UDCA) for liver-transplant recipients has been reported to reduce the frequency of acute rejection episodes. To explore this effect further, UDCA was given to rats in an experimental heart transplantation model, with or without concomitant immunosuppressive treatment with antihymocyte globulin (ATG). UDCA was administered orally 7 days before and 14 days after transplantation. Rats treated with UDCA alone or in combination with ATG were compared with untreated controls and ATG-treated recipients. Adjuvant treatment with UDCA was found to induce prolonged graft survival and increase the amount of transplant tolerance in rats. Serum levels of bilirubin and aminotransferases were not altered irrespective of the UDCA dose given. The results indicate that UDCA has an immunomodulatory capacity that might not be restricted to the liver, but also might apply to other transplanted organs as well.
|
|
| 12. |
- Olausson, Michael, 1956, et al.
(författare)
-
Successful combined partial auxiliary liver and kidney transplantation in highly sensitized cross-match positive recipients
- 2007
-
Ingår i: American journal of transplantation. - 1600-6135. ; 7:1, s. 130-6
-
Tidskriftsartikel (refereegranskat)abstract
- Combined liver and renal transplantations can be performed against a positive cross-match, indicating that the liver protects the kidney from the harmful HLA antibodies. This led us to the hypothesis that a partial auxiliary liver graft may have a similar protective effect when performed together with the kidney in highly sensitized patients. Seven patients, with broadly reacting HLA antibodies and positive crossmatches, were transplanted with a partial liver and a kidney from the same donor. In one of the cases a living donor was used. We performed lymphocytotoxic and flow cross-matches before and after the transplantation. Cross-matches turned negative after grafting in five of seven cases. The kidney function was excellent, without rejections, during the follow-up (24-60 months) in these patients. In two cases the cross-match remained positive after transplantation, one with a never-functioning renal graft and the other with an early graft failure, probably due to humoral rejection. A simultaneous transplantation of a partial auxiliary liver graft from the same donor, with the sole purpose of protecting the kidney from harmful lymphocytotoxic antibodies, can be performed successfully despite a positive cross-match and may thus be a new option of treatment for highly sensitized patients waiting for a kidney transplant.
|
|
| 13. |
- Addjin-Tettey, Theodora Dame, et al.
(författare)
-
Towards Sustainable Journalism in Sub-Saharan Africa
- 2021
-
Ingår i: Annual conference 2021 Bergen. ; , s. 103-103
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Sustainable Journalism has been developed and advocated by Peter Berglez, Ulrika Olausson and Mart Ots to respond to present and future global sustainability challenges as well as future sustainability of journalism. The relevance and contribution of Sustainable Journalism as a concept and practice is twofold. First, the concept refers to a journalism that integrates the three sustainability dimensions and does not isolate environmental issues from social and economic conditions. Second, Sustainable Journalism also addresses two intertwined challenges of our time: the sustainability crisis of society and the sustainability crisis of journalism itself. Having been developed in the north and still in its epistemological infancy, we found a need to explore its various dimensions and applications further in the south. Consequently, we critically explored how sustainable journalisms hould be defined and practised in sub-Saharan Africa. Stakeholder discussions were held with journalists, news editors and representatives of media development organisations in Nigeria, Ghana, Liberia, and Kenya to ascertain what they made of Sustainable Journalism and its application in SSA. With the trend of political actors dominating media ownership, resulting in limited editorial independence and polarized media; and insufficient financial sustainability connected to poor quality reporting, among others, we propose that sustainable Journalism should be context driven. Consequently, all media environments should be encouraged to tailor their own way of practicing Sustainable Journalism based on their unique social, environmental and economic circumstances. We also suggest the establishment of a Sustainable Journalism Partnership in sub-Saharan Africa to enhance the development and implementation of the concept.
|
|
| 14. |
- Adjin-Tettey, Theodora Dame, et al.
(författare)
-
Towards sustainable journalism in sub-Sahara : Policy brief
- 2021
-
Rapport (populärvet., debatt m.m.)abstract
- The sustainability crisis of society, e.g. environmental crises, democratic crises, poverty, financial crises, armed conflicts, etc. Obviously, journalism has a crucial role to play here since it contributes greatly to the public agenda, as well as people’s understanding – and hence the handling – of such challenges. The sustainability crisis of journalism itself, which stems from lower advertising, decreasing subsidies for public service media, falling consumption, lack of trust in media among citizens, and fierce competition from online information brokers and advertising.The complex reality of today requires this kind of integrated journalistic approach in order to uphold the democratic function and not least the legitimacy of professional journalism. Consequently, journalism’s response to the sustainability challenges can be seen as a prerequisite for the future sustainability of journalism itself, ranging from high-quality, in-depth coverage to robust business models, but also extending into considerations of media systems and relations with governments and business interests.In this way, sustainable journalism attempts to counter the obvious risk that the efforts to maintain economic sustainability of the journalistic enterprise take place at the expense of professional journalism’s social/democratic mission – to hold power to account and to inform citizens, and to spur public engagement about current and future economic, social, and environmental challenges.Furthermore, sustainable journalism refers to journalism that integrates the three sustainability dimensions in its coverage and its financing and does not isolate environmental issues from social and economic conditions as if they were siloed issues. Examples of this kind of integrated approach would be journalism that:reflects the economic aspects of an increasingly globalising society at the same time as it acknowledges the social and environmental consequences of these aspects,is underwritten by value from new advertising formats that doesn’t jeopardise the integrity and trust of citizens, andinterlinks local and national consequences of (for instance) climate change with their economic and social ramifications on a global scale.Given the importance of the Agenda 2030 and the Paris agreement, another function of sustainable journalism can be seen as carefully scrutinising the compliance of the Paris Agreement and Agenda 2030 as well as exposing the sustainability challenges associated with them.However, sustainable journalism may not be practised in the same way in all countries and by each publisher, as each country and media institution has unique challenges that confront their sustainability. In order to appreciate how sustainable journalism is to be practised in the sub-Saharan African context, it is important to establish the setting within which media organisations and journalists carry out their informational mandate. It is equally important to explore the issues that confront the environmental, social and economic sustainability of media within sub-Saharan Africa.This study consequently includes a summary of three different sets of discussions, held over a two-week period in January 2021 with reporters, news editors and representatives of media development organisations in Nigeria, Ghana, Liberia, and Kenya. The aim was to ascertain how these key stakeholders regard sustainable journalism and its possible application in sub-Saharan Africa.The golden thread that ran through discussions was that sustainable journalism connects critical developmental issues in sub-Saharan Africa to the practice of journalism. Participants were of the view that there is a general trend of slow social and economic development within sub-Saharan Africa, coupled with a looming environmental crisis, due inter alia to poor environmental governance. They also agreed that what uniquely sets sustainable journalism apart from other new journalistic approaches is the provision of a model or framework for journalists to address contemporary issues that are tied to sustainable development. And while providing this framework, it also obliges journalists to concentrate on local contexts and the three interdependent dimensions of sustainability, and to find ways to win support for the sustainability of their own service to society.
|
|
| 15. |
|
|
| 16. |
- Baldimtsi, Evangelia, 1981-, et al.
(författare)
-
HbA1c and the risk of developing peripheral neuropathy in childhood-onset type 1 diabetes : A follow-up study over 3 decades
- 2024
-
Ingår i: Diabetes/Metabolism Research Reviews. - : John Wiley & Sons. - 1520-7552 .- 1520-7560. ; 40:5
-
Tidskriftsartikel (refereegranskat)abstract
- AIMS: We have evaluated long-term weighted mean HbA1c (wHbA1c), HbA1c variability, diabetes duration, and lipid profiles in relation to the development of diabetic peripheral neuropathy (DPN), nephropathy, and retinopathy in childhood-onset type 1 diabetes.MATERIALS AND METHODS: In a longitudinal cohort study, 49 patients (21 women) with childhood-onset type 1 diabetes were investigated with neurophysiological measurements, blood tests, and clinical examinations after a diabetes duration of 7.7 (±3.3) years (baseline) and followed with repeated examinations for 30.6 (±5.2) years. We calculated wHbA1c by integrating the area under all HbA1c values since the diabetes diagnosis. Lipid profiles were analysed in relation to the presence of DPN. Long-term fluctuations of HbA1c variability were computed as the standard deviation of all HbA1c measurements. Data regarding the presence of other diabetes complications were retrieved from medical records.RESULTS: In this follow-up study, 51% (25/49) of the patients fulfilled electrophysiological criteria for DPN. In nerve conduction studies, there was a deterioration in the amplitudes and conduction velocities for the median, peroneal, and sural nerves over time. Patients with DPN had a longer duration of diabetes, higher wHbA1c, and increased HbA1c variability. The lowest wHbA1c value associated with the development of DPN was 62 mmol/mol (7.8%). The presence of albuminuria and retinopathy was positively correlated with the presence of neuropathy.CONCLUSIONS: More than half of the patients had developed DPN after 30 years. None of the patients who developed DPN had a wHbA1c of less than 62 mmol/mol (7.8%).
|
|
| 17. |
- Barregård, Lars, 1948, et al.
(författare)
-
Cadmium, mercury, and lead in kidney cortex of living kidney donors: Impact of different exposure sources.
- 2010
-
Ingår i: Environmental research. - : Elsevier BV. - 1096-0953 .- 0013-9351. ; 110:1, s. 47-54
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Most current knowledge on kidney concentrations of nephrotoxic metals like cadmium (Cd), mercury (Hg), or lead (Pb) comes from autopsy studies. Assessment of metal concentrations in kidney biopsies from living subjects can be combined with information about exposure sources like smoking, diet, and occupation supplied by the biopsied subjects themselves. OBJECTIVES: To determine kidney concentrations of Cd, Hg, and Pb in living kidney donors, and assess associations with common exposure sources and background factors. METHODS: Metal concentrations were determined in 109 living kidney donors aged 24-70 years (median 51), using inductively coupled plasma-mass spectrometry (Cd and Pb) and cold vapor atomic fluorescence spectrometry (Hg). Smoking habits, occupation, dental amalgam, fish consumption, and iron stores were evaluated. RESULTS: The median kidney concentrations were 12.9microg/g (wet weight) for cadmium, 0.21microg/g for mercury, and 0.08microg/g for lead. Kidney Cd increased by 3.9microg/g for a 10 year increase in age, and by 3.7microg/g for an extra 10 pack-years of smoking. Levels in non-smokers were similar to those found in the 1970s. Low iron stores (low serum ferritin) in women increased kidney Cd by 4.5microg/g. Kidney Hg increased by 6% for every additional amalgam surface, but was not associated with fish consumption. Lead was unaffected by the background factors surveyed. CONCLUSIONS: In Sweden, kidney Cd levels have decreased due to less smoking, while the impact of diet seems unchanged. Dental amalgam is the main determinant of kidney Hg. Kidney Pb levels are very low due to decreased exposure.
|
|
| 18. |
- Belkheiri, Tallal, 1985, et al.
(författare)
-
Effect of pH on Kraft Lignin Depolymerisation in Subcritical Water
- 2016
-
Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 1520-5029 .- 0887-0624. ; 30:6, s. 4916-4924
-
Tidskriftsartikel (refereegranskat)abstract
- Softwood kraft lignin was depolymerized using subcritical water (623 K and 25 MPa) in a continuous small pilot unit. ZrO2 and K2CO3 were used as catalysts, and phenol was used as capping agent to suppress repolymerization. The effect of pH was investigated by adding KOH in five steps to the feed. The yield of water-soluble organics increased with pH. The yield of bio-oil was also influenced by the pH and varied between 28 and 32 wt %. The char yield on the zirconia catalyst showed a minimum at pH 8.1. The yield of suspended solids was low at pH below 8.1 but increased at higher pH values. The oxygen content in the bio-oil was only 15 wt %, compared to about 26 wt % in the kraft lignin.
|
|
| 19. |
- Belkheiri, Tallal, 1985, et al.
(författare)
-
Kraft Lignin Depolymerization in Near-Critical Water: Effect of Changing Co-Solvent
- 2014
-
Ingår i: Cellulose Chemistry and Technology. - 0576-9787. ; 48:9-10, s. 813-818
-
Tidskriftsartikel (refereegranskat)abstract
- As part of developing a process to valorize lignin in a pulp mill with lignin separation, the depolymerisation of lignin to valuable chemicals was investigated in near-critical water. This was done by using methanol as co-solvent and hydrogen donor, phenol to suppress repolymerization (e.g. formation of char), and ZrO2 as a heterogeneous catalyst, with potassium carbonate as a co-catalyst. The reaction was carried out in a continuous flow fixed-bed reactor (500 cm(3)), at 280-350 degrees C and 25MPa. An important aspect is to suppress char formation. Therefore, the char formation was studied by using different concentrations of methanol and phenol. The char yield varied between 14% and 26%. When using methanol as the only co-solvent, the char yield decreased with increasing methanol concentration. Adding phenol resulted in a further decrease. The reactor outlet consisted mainly of two liquid phases, an aqueous and an oil phase, mixed together. The chemical analysis of the aqueous phase showed the presence of mainly phenolic compounds, for instance guaiacol, catechol, phenol and cresol.
|
|
| 20. |
- Björnsson, Einar, 1958, et al.
(författare)
-
Long-term follow-up of patients with alcoholic liver disease after liver transplantation in Sweden: impact of structured management on recidivism
- 2005
-
Ingår i: Scandinavian journal of gastroenterology. - 0036-5521. ; 40:2, s. 206-16
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: No systematic evaluation has been performed previously in the Scandinavian countries on patients transplanted for alcoholic liver disease (ALD). Data are limited on the impact of structured management of the alcohol problem on the risk of recidivism following transplantation in ALD. MATERIAL AND METHODS: A total of 103 ALD patients were compared with a control group of patients with non-alcoholic liver disease (NALD). The recidivism rates for ALD patients transplanted between 1988 and 1997 as well as after 1998 (institution of structured management) were compared. RESULTS: The median follow-up was 31 (6-60) months in the ALD group and 37 (12-63) months in the control group (NS). The overall survival rates at 1- and 5 years were, respectively, 81% and 69% for the ALD group and 87% and 83% for the non-alcoholic group. The proportion of patients with Child-Pugh C (75%) was higher in ALD patients than in NALD patients (44%) (p<0.01). Thirty-two (33%) ALD patients resumed taking some alcohol after transplantation; 17 patients (18%) were heavy drinkers. A multivariate analysis showed that: sex, age, marital and employment status, benzodiazepine use and a history of illicit drug abuse did not predict the risk of alcohol relapse post-Tx. Nineteen out of 40 (48%) patients transplanted before the start of structured management had resumed alcohol but 13 (22%) out of 58 after this intervention (p=0.002). CONCLUSIONS: ALD is a good indication for liver transplantation, with similar results in the ALD patients. Structured management of the alcohol problem before and after transplantation is important in minimizing the risk of recidivism.
|
|
| 21. |
|
|
| 22. |
- Borgenvik, Anna, et al.
(författare)
-
CDK2 as a therapeutic target in MYC-driven medulloblastoma
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Group 3 medulloblastoma (MB) is a malignant pediatric brain tumor that shows aberrant cell cycle activation, therapy resistance, and poor prognosis. Here, we identified that MYC expression and poor prognosis in Group 3 MB correlates with elevated levels of core cell cycle members CDK2 and cyclin A2, suggesting they would be promising targets for direct inhibition. Tumor cells in a novel transgenic MYC-driven MB mouse model further displayed increased p27 levels, decreased viability, and cell growth in vitro upon conditional CDK2 depletion using tamoxifen-induced recombination. Human Group 3 MB cells transduced with dominant-negative CDK2 mutants similarly exhibited decreased viability and increased p27 activation. As compared to controls, CDK2-depleted cells responded less to CDK2-specific inhibitors but were not more sensitive to BET inhibition or CDK4/6 inhibition as previously proposed. We finally used global transcriptional profiling and found that mTOR and B-Myb/ZMYM2 signaling pathways are compensating for CDK2 loss in Group 3MB cells. Our analysis suggests that specific inhibitors of these pathways could in combination with approved cell cycle inhibitors provide more efficient treatments for this severe childhood brain cancer.
|
|
| 23. |
- Brännström, Mats, 1958, et al.
(författare)
-
Livebirth after uterus transplantation.
- 2015
-
Ingår i: Lancet. - 1474-547X. ; 385:9968, s. 607-616
-
Tidskriftsartikel (refereegranskat)abstract
- Uterus transplantation is the first available treatment for absolute uterine infertility, which is caused by absence of the uterus or the presence of a non-functional uterus. Eleven human uterus transplantation attempts have been done worldwide but no livebirth has yet been reported.
|
|
| 24. |
- Brännström, Mats, 1958, et al.
(författare)
-
Reproductive, obstetric, and long-term health outcome after uterus transplantation: results of the first clinical trial
- 2022
-
Ingår i: Fertility and Sterility. - : Elsevier BV. - 0015-0282 .- 1556-5653. ; 118:3, s. 576-585
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: To evaluate reproductive, obstetric, and long-term health of the first completed study of uterus transplantation (UTx). Design: Prospective. Setting: University hospital. Patient(s): Nine live donor UTx procedures were conducted and seven were successful. Donors, recipients, and children born were observed. Intervention(s): In vitro fertilization was performed with embryo transfer (ET) of day 2 or day 5 embryos in natural cycles. Pregnancies and growth trajectory of the children born were observed. Health-related quality of life, psychosocial outcome, and medical health of donors and recipients were evaluated by questionnaires. Main Outcome Measure(s): The results of in vitro fertilization, pregnancies, growth of children, and long-term health of patients were reported. Result(s): Six women delivered nine infants, with three women giving birth twice (cumulative birth rates of 86% and 67% in surgically successful and performed transplants, respectively). The overall clinical pregnancy rate (CPR) and live birth rate (LBR) per ET were 32.6% and 19.6%, respectively. For day 2 embryos, the CPR and LBR per ET were 12.5% and 8.6%, respectively. For day 5 embryos, the CPR and LBR per ET were 81.8% and 45.4%, respectively. Fetal growth and blood flow were normal in all pregnancies. Time of delivery (median in full pregnancy weeks + days [ranges]) by cesarean section and weight deviations was 35 + 3 (31 + 6 to 38 + 0) and -1% (-13% to 23%), respectively. Three women developed preeclampsia and four neonates acquired respiratory distress syndrome. All children were healthy and followed a normal growth trajectory. Measures of long-term health in both donors and recipients were noted to be favorable. When UTx resulted in a birth, scores for anxiety, depression, and relationship satisfaction were reassuring for both the donors and recipients. Conclusion(s): The results of this first complete UTx trial show that this is an effective infertility treatment, resulting in births of healthy children and associated with only minor psychological and medical long-term effects for donors and recipients. Clinical Trial Registration Number: NCT02987023.
|
|
| 25. |
- Castedal, Maria, 1964, et al.
(författare)
-
Preemptive therapy with pegylated interferon alpha-2b and ribavirin after liver transplantation for hepatitis C cirrhosis
- 2005
-
Ingår i: Transplantation proceedings. - 0041-1345. ; 37:8, s. 3313-4
-
Tidskriftsartikel (refereegranskat)abstract
- We present our results of preemptive treatment with pegylated interferon and ribavirin after liver transplantation for hepatitis C cirrhosis. PATIENTS: Between September 2001 and August 2002, four patients were started on combination therapy with pegylated interferon-alpha-2b (1microg/kg weekly) and ribavirin (400-1000 mg/d) 3 to 4 weeks' posttransplant. Treatment was continued for 6 (genotype 3a, 2 patients) or 12 (genotype 1b, 2 patients) months. Virologic and biochemical responses as well as side effects were evaluated. RESULTS: Two patients (genotype 3a) became HCV (hepatitis C virus)-RNA negative after 3 months of therapy and are persistently negative 20 and 14 months after end of therapy. One patient (genotype 1b) became HCV-RNA negative 6 months after start of treatment, but therapy had to be withdrawn after 9 months owing to fatigue and suspicion of angina pectoris. One patient who was later retransplanted because of hepatic artery thrombosis discontinued therapy after 2.5 months owing to anemia, leukopenia, and no signs of HCV-RNA reduction. Interestingly, two of the responders were nonresponders prior to liver transplant. Median ALT levels at start of therapy were 98 U/L (r = 60-126) and 12 months later 40 U/L (r = 24-58) (n = 4). No rejection episode was detected. CONCLUSION: In patients liver-transplanted due to HCV-cirrhosis, combination therapy with pegylated interferon and ribavirin can be effective and safe in the early posttransplant period, thus preventing recurrent hepatitis C.
|
|
| 26. |
|
|
| 27. |
|
|
| 28. |
- Fistouris, Johan, et al.
(författare)
-
Pseudoaneurysm of the hepatic artery following liver transplantation
- 2006
-
Ingår i: Transplantation proceedings. - 0041-1345. ; 38:8, s. 2679-82
-
Tidskriftsartikel (refereegranskat)abstract
- We report 12 cases of pseudoaneurysm hepatic artery (PA) among 825 liver transplantations (OLT) performed between January 1985 and December 2005. In the early period (1985 to 1995), the incidence was 2.6% and in the later period (1996 to 2005), 0.9%. Median time to onset was 39.5 days post-OLT (range 14 days to 5 years). Six patients presented with rupture into the peritoneum (n = 4) or gastrointestinal tract (n = 2), while five patients presented with gastrointestinal bleed due arteriobiliary fistulation with hemobilia. The twelfth PA was found incidentally during retransplantation. PAs were detected with radiological imaging (n = 4), exploratory laparotomy (n = 6), at autopsy (n = 1) or at retransplantation (n = 1). We performed immediate revascularization, after surgical excision was performed in three and endovascular embolization in one patient. In six patients hepatic artery ligation without revascularization was inevitable with subsequent successful retransplantation in four patients. No PA-specific treatment was attempted in two cases due to the poor prognosis or diagnostic ambiguity. In 10 cases microbial pathogens were cultured in the blood, subhepatic abscesses, or from the wall of the hepatic artery. A hepaticojejunostomy was performed for biliary reconstruction in six patients and two had a hepaticojejunostomy conversion due to biliary leak. Survival in the early period (1985 to 1995) was 14%, whereas during the later period (1996 to 2005), the survival increased to 100% with a 4.2-year median follow-up (range 7.4 months to 6.9 years). Infrequently PA complicates OLT, becoming evident primarily after rupture with hemoperitoneum or a gastrointestinal bleed. Early recognition with angiography is important but acute hemorrhage often requires immediate exploration with ligation of the PA, although surgical or endovascular exclusion of the PA followed by revascularization provides a feasible treatment option.
|
|
| 29. |
- Flodén, Anne, 1957, et al.
(författare)
-
Calculation and comparison of the model for end-stage liver disease (MELD) score in patients accepted for liver transplantation in 1999 and 2004
- 2007
-
Ingår i: Transplantation proceedings. - : Elsevier BV. - 0041-1345. ; 39:2, s. 385-6
-
Tidskriftsartikel (refereegranskat)abstract
- There has been a need to assess the "sickness degree" in patients with acute and chronic hepatic failure. The Model for End-Stage Liver Disease (MELD) score was developed as a tool for a more objective estimate of the "degree" of sickness in patients with chronic liver disease. In this study, the MELD score was retrospectively calculated and compared in adult patients accepted for orthotopic liver transplantation (OLT) in our institution in 1999 and 2004. We analyzed the gender, age, and MELD score associated with different indications for OLT during this period.
|
|
| 30. |
- Flodén, Anne, 1957, et al.
(författare)
-
MELD [corrected] score in patients accepted for liver transplantation 1994 to 2004
- 2006
-
Ingår i: Transplantation proceedings. - 0041-1345. ; 38:8, s. 2673-4
-
Tidskriftsartikel (refereegranskat)abstract
- There has been a need to be able to grade the "degree of sickness" in patients with acute and chronic hepatic failure. The Model for End-Stage Liver Disease (MELD) score was developed as a tool to give a more objective estimate of the degree of sickness in patients with chronic liver disease. In this study the MELD score was compared retrospectively in adult patients accepted for liver transplantation (OLT) at our institution in 1994, 1999, and 2004. Gender, age, and MELD score associated with different indications for OLT were analyzed for the same period. The MELD scores were unchanged between the examined years, and there was no difference between male and female patients accepted for OLT. Comparing MELD score between male and female patients, there was a potential risk for discrimination of female patients due to their reduced muscle mass, resulting in a lower serum creatinine and a lower MELD score. There was no difference in MELD score comparing 1994, 1999, and 2004 for patients with cirrhosis. Patients with acute hepatic failure had the highest MELD scores while patients undergoing OLT because of malignancy had the lowest MELD score. MELD score seemed to be a useful tool for retrospective analyzes of potential OLT recipients.
|
|
| 31. |
- Friman, Styrbjörn, 1948, et al.
(författare)
-
Kidney transplantation--a 46-year experience from the Transplant Institute, Sahlgrenska University Hospital, Gothenburg, Sweden.
- 2011
-
Ingår i: Clinical transplants. - 0890-9016. ; , s. 119-25
-
Tidskriftsartikel (refereegranskat)abstract
- The limiting factor in organ transplantation is the availability of organs. Ongoing work to improve donation rates both at the public and the organizational level in donating hospitals is essential. We also think that encouragement of live donation is important, and the possibility of ABO incompatible transplantation has increased the number of LD transplantations. The one-year graft survival rate is excellent and focus has shifted towards achieving long-term results to reduce the attrition rate. There is also an increasing interest in studying and working to reduce comorbidities on a long-term basis and thus, improve survival rates and recipient quality of life.
|
|
| 32. |
|
|
| 33. |
- Fryk, Emanuel, et al.
(författare)
-
Hyperinsulinemia and insulin resistance in the obese may develop as part of a homeostatic response to elevated free fatty acids: A mechanistic case-control and a population-based cohort study
- 2021
-
Ingår i: Ebiomedicine. - : Elsevier BV. - 2352-3964. ; 65
-
Tidskriftsartikel (refereegranskat)abstract
- Background: It is commonly accepted that in obesity free fatty acids (FFA) cause insulin resistance and hyperglycemia, which drives hyperinsulinemia. However, hyperinsulinemia is observed in subjects with normoglycaemia and thus the paradigm above should be reevaluated. Methods: We describe two studies: MD-Lipolysis, a case control study investigating the mechanisms of obesity-driven insulin resistance by a systemic metabolic analysis, measurements of adipose tissue lipolysis by microdialysis, and adipose tissue genomics; and POEM, a cohort study used for validating differences in circulating metabolites in relation to adiposity and insulin resistance observed in the MD-Lipolysis study. Findings: In insulin-resistant obese with normal glycaemia from the MD-Lipolysis study, hyperinsulinemia was associated with elevated FFA. Lipolysis, assessed by glycerol release per adipose tissue mass or adipocyte surface, was similar between obese and lean individuals. Adipose tissue from obese subjects showed reduced expression of genes mediating catecholamine-driven lipolysis, lipid storage, and increased expression of genes driving hyperplastic growth. In the POEM study, FFA levels were specifically elevated in obese-overweight subjects with normal fasting glucose and high fasting levels of insulin and C-peptide. Interpretation: In obese subjects with normal glycaemia elevated circulating levels of FFA at fasting are the major metabolic derangement candidate driving fasting hyperinsulinemia. Elevated FFA in obese with normal glycaemia were better explained by increased fat mass rather than by adipose tissue insulin resistance. These results support the idea that hyperinsulinemia and insulin resistance may develop as part of a homeostatic adaptive response to increased adiposity and FFA. (C) 2021 The Author(s). Published by Elsevier B.V.
|
|
| 34. |
- Gourdon, Mathias, 1980, et al.
(författare)
-
Fouling Layer Growth in Black Liquor Falling Film Evaporation
- 2007
-
Ingår i: Proceedings of the International Chemical Recovery Conference 2007, May 29-June 1, 2007, Quebec City, Canada , s. 473-477.
-
Konferensbidrag (refereegranskat)abstract
- The fouling behaviour (both local and overall) for black liquor evaporation in a falling film evaporator has been investigated. The experimental results showed that, in the interval of the studied dry solids content, the fouling rates were independent of dry solids content as long as it exceeded a critical limit. The fouling rates were seen to have a strong dependence on circulation flow rate; doubling the circulation flow rate resulted in about halved fouling rates. The local heat flux measurements showed great differences between fouling rates vertically along the heat transfer surface. The fouling was seen to start from the bottom and then expanded upwards.
|
|
| 35. |
- Gourdon, Mathias, 1980, et al.
(författare)
-
Scale formation and growth when evaporating black liquor with high carbonate to sulphate ratio
- 2008
-
Ingår i: Nordic Pulp and Paper Research Journal. - 2000-0669 .- 0283-2631. ; 23:2, s. 231-239
-
Tidskriftsartikel (refereegranskat)abstract
- Scaling in black liquor evaporators has for longbeen recognised as a problem. Most problems are connected tothe precipitation of sodium salts. In the black liquor evaporation,as the black liquor gets concentrated, sodium carbonateand sodium sulphate will saturate and precipitate from the solution.When precipitation occurs the salts may crystallise on theheat transfer surface or adhere to the surface as well as they cancrystallise in the bulk. If crystals remain on the heat transfersurface an insulating layer of scales can quickly build up causingthe heat flux to drop and eventually forcing the evaporatorto be shut down for cleaning. The research in this paper focused primarily on scaling forblack liquors with high ratio of carbonate to sulphate, a conditionshown to be important in industrial black liquor evaporators(Frederick et al. 2004). The scaling behaviour was investigatedexperimentally in a falling film evaporator. The aim wasto find favourable operating conditions decreasing or eliminatingscaling. The examined parameters were different heat flux,circulation flow rate, internal residence time and black liquorfeed concentration. For the investigated operating conditions themain parameters affecting scaling were the circulation flow rateand heat flux whereas the scaling rate was seen independent ofthe internal residence time.
|
|
| 36. |
- Gourdon, Mathias, 1980, et al.
(författare)
-
Sodium Salt Scaling in Black Liquor Evaporators – Pilot Plant Results and Industrial Significance
- 2010
-
Ingår i: Proceedings of International Chemical Recovery Conference, Williamsburg, Virginia, USA, March 29 – April 1 2010, s. 298-312. - 9781595101983 ; 2, s. 298-311
-
Konferensbidrag (refereegranskat)abstract
- In industrial black liquor evaporation plants large amounts of sodium crystals are produced every day which all has the potential to scale the evaporator surfaces. In this project, research on the crystallization during evaporation of softwood black liquor has been performed. The results are based on measurements in a research black liquor evaporator.The distribution of scales vertically along the heat transfer surface has been investigated as well as the influence of different operating conditions, such as the circulating flow rate of black liquor, the residence time for the black liquor in the evaporator and the temperature difference between the liquor and the heating steam.The sodium scales formed during evaporation are mainly in the form of double salts of sodium carbonate and sodium sulfate. The ratio between the two salts is one important parameter affecting the crystallization and scaling. The effect of the carbonate-to-sulfate ratio has been investigated for aqueous sodium carbonate – sodium sulfate solutions. In this paper, the results of these investigations are presented and a number of industrial significances are illustrated.
|
|
| 37. |
|
|
| 38. |
|
|
| 39. |
- Hedner, Thomas, et al.
(författare)
-
Stora förändringar i den globala läkemedelsindustrin
- 2012
-
Ingår i: Läkartidningen. - Stockholm. - 0023-7205 .- 1652-7518. ; 109:7, s. 324-325
-
Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Den globala läkemedelsindustrin är under kraftig för- ändring. Under de senaste tio åren har 300 000 arbets- tillfällen lagts ner i »Big Pharma«. I stället utvecklas mindre, kreativa och »öppna« innovationsnätverk och organisationsstrukturer för att ta fram nya läkemedel, skriver Thomas Hedner och medförfattare.
|
|
| 40. |
- Herlenius, Gustaf, 1961, et al.
(författare)
-
Conversion From Calcineurin Inhibitor to Either Mycophenolate Mofetil or Sirolimus Improves Renal Function in Liver Transplant Recipients With Chronic Kidney Disease : Results of a Prospective Randomized Trial
- 2010
-
Ingår i: Transplantation Proceedings. - : Elsevier BV. - 0041-1345 .- 1873-2623. ; 42:10, s. 4441-4448
-
Tidskriftsartikel (refereegranskat)abstract
- Background. Chronic kidney disease (CKD) has emerged as a significant cause of morbidity and a risk factor for mortality after orthotopic liver transplantation (OLT). The use of calcineurin inhibitor (CNI)-based immunosuppression is an important etiologic factor for developing CKD. CNI discontinuation or minimization protocols with replacement of the CNI with non-nephrotoxic drugs, such as mycophenolate mofetil (MMF) or sirolimus (SRL), may have the potential to preserve or recover renal function. Patients and Methods. In this prospective, randomized, single-center study with CNI discontinuation, OLT recipients with CKD (measured glomerular filtration rate [GFRm] 15-45 mL/min/1.73 m(2)) were randomized to either SRL or MMF-based immunosuppression. The main objective was to study the effect of CNI discontinuation on renal function. Secondary aims were to assess the frequency of biopsy-proven acute rejection episodes (BPAR) and adverse events (AE). Renal function was followed with GFRm using 51-Chromium EDTA clearance at baseline, 3 months, and 1 year. Patients were stratified according to baseline GFRm > versus <30 mL/min/1.73 m(2). The 25 patients were enrolled for MMF (n = 13) or SRL (n = 12). The median age at inclusion was 59 years (range, 25-66) and the median number of years after OLT was 4.4 (range, 1-13). Twenty-two patients were followed up for a year; MMF (n = 12) and SRL (n = 10). Results. Mean GFRm for the whole cohort (n = 25) was 31+/-8 mL/min/1.73 m(2) at baseline. After 3 months the GFRm (n = 23) increased to 40+/-10 mL/min/1.73 m(2) (P = .0001) and at 1 year 42 +/- 11 mL/min/1.73 m(2) (n = 22). There was not significant difference between the MMF and the SRL study arms. The cohort (n = 8) with baseline GFRm <30 mL showed a 63% (P = .003) increased filtration after 1 year. There was no significant difference in the frequency or severity of AE between the study arms with the exception of oral ulcerations and persistent hypertriglyceridemia in the SRL group. Two deaths occurred, 1 in each study arm, both probably unrelated to the change in immunosuppression. There were no BPAR episodes. Conclusion. CNI discontinuation and replacement with either MMF or SRL resulted in a significant improvement in renal function even in those patients with severe CKD. The protocol was effective with no acute rejection episodes. The SRL arm showed a higher frequency of oral apthous ulcerations and hypertriglyceridemia. Future studies addressing long-term renal function after CNI discontinuation are needed.
|
|
| 41. |
- Herlenius, Gustaf, 1961, et al.
(författare)
-
Early renal function post-liver transplantation is predictive of progressive chronic kidney disease.
- 2008
-
Ingår i: Scandinavian journal of gastroenterology. - 0036-5521. ; 43:3, s. 344-9
-
Tidskriftsartikel (refereegranskat)abstract
- With improvements in long-term results after liver transplantation, chronic kidney disease (CKD) has become a highly relevant problem. The early measurement of the glomerular filtration rate (GFR) can identify those patients who are at risk of developing CKD years after liver transplantation. The aims of this study were to describe the prevalence of CKD 5 years after liver transplantation, to study the correlation between measured GFR early after transplantation and late renal function and to identify patients at risk of developing late CKD after liver transplantation.
|
|
| 42. |
|
|
| 43. |
- Hydén, Susan, et al.
(författare)
-
The scent of sandstone – exploring a TRB material
- 2015
-
Ingår i: Neolithic Diversities : Perspectives from a conference in Lund, Sweden Acta Archaeologica Lundensia, Series in 8o. - 9789189578609 ; 65, s. 224-232
-
Bokkapitel (refereegranskat)abstract
- The aim of this article is to briefly explore how quartz-rich sandstone might have been perceived by TRB societies. Using the senses as a point of departure, it discusses how sandstone was selected for grinding stones and for dry walling in megaliths, emphasizing the significance of the visual as well as the mechanical properties of the material. The article also acknowledges the complexity of the way in which the material was perceived. The significance of sandstone was shaped by context, implying that a changing context altered its significance. Ultimately, this study is a call for taking materials seriously by exploring them in a more nuanced way. Analogies, for example, can be very useful – not as proof, but as a way of raising questions and scenting the diversity of the Neolithic.
|
|
| 44. |
|
|
| 45. |
- Johansson, Miriam, 1978, et al.
(författare)
-
A new test facility for black liquor evaporation
- 2005
-
Ingår i: Proceedings of the Heat-SET 2005 conference, Heat transfer in components and systems for sustainable energy technologies.
-
Konferensbidrag (refereegranskat)abstract
- In the pulp and paper industry, the black liquor evaporation process is a large energy consumer. Black liquor is generated during the production of chemical pulp from wood or annual plants and its main constituents are dissolved wood (lignin), cooking chemicals and a large amount of process water. Research on the energy efficiency of the pulp and paper process has shown that heat integration of the evaporation with other parts of the process might considerably increase energy recovery and thus save significant amounts of live steam. The aim of our research is thus to develop basic experimental and theoretical knowledge about heat transfer during evaporation of black liquor under new conditions. To be able to obtain this knowledge a research evaporator has been built at Chalmers in cooperation with Kvaerner Power. The evaporator consists of one 4.5 m long vertical tube with a falling film of black liquor flowing on the outside. Heating is accomplished by condensing steam on the inside of the tube. To be able to measure heat flux locally, the evaporator tube is equipped with 18 pairs of thermocouples mounted at different positions both vertically and circumferentially. The paper will focus on the design of the temperature and heat flux measurement system, but will also include examples of measurement data obtained. Heat transfer coefficients from the experimental measurement are in the same range as the heat transfer coefficient calculated from the theoretical correlations from literature, however the measurement conditions in the initial tests have not been stable enough to reach acceptable accuracy levels.
|
|
| 46. |
- Johansson, Miriam, 1978, et al.
(författare)
-
An implementation-oriented heat transfer model for black liquor evaporation
- 2007
-
Ingår i: Proceedings of the International Chemical Recovery Conference 2007, May 29-June 1, 2007, Quebec City, Canada. ; :Part 1, s. 155-158
-
Konferensbidrag (refereegranskat)abstract
- To improve the energy efficiency in the pulp and paper process, thermal integration of the evaporation plant with other parts of the plant is an option. Evaporation of black liquor up to higher dry solid content gives a higher heating value of the black liquor used in the recovery boiler. A high dry solid content means that the viscosity of the black liquor becomes very high. The link between viscosity and heat transfer for black liquor is therefore interesting. Experimental and theoretical knowledge is essential for proper design of evaporators for this purpose. A simplified model for the black liquor falling-film evaporation heat transfer coefficient is suggested. Without a substantial increase in uncertainty, only dependence on mass flow rate and viscosity is included in the model. The model is created from experimental data from experiments performed with a research evaporation plant with a 4.5 m long evaporator tube. Heat transfer in falling-film evaporators has been studied by other researchers before. The falling-film black liquor evaporation heat transfer coefficient dependence on mass flow rate (in a limited mass flow rate range) and viscosity according to this study is in agreement with some of these earlier studies. Above a certain mass flow rate limit, however, the experimental heat transfer coefficient was constant or even decreased with increasing mass flow rate.
|
|
| 47. |
|
|
| 48. |
- Johansson, Miriam, 1978, et al.
(författare)
-
Falling film evaporation of black liquor - comparison with general heat transfer correlations
- 2006
-
Ingår i: Nordic Pulp and Paper Research Journal. - 2000-0669 .- 0283-2631. ; 21:4/2006, s. 496-506
-
Tidskriftsartikel (refereegranskat)abstract
- A research evaporator has been built to increase knowledge about heat transfer in evaporation of black liquor. Existing models for heat transfer in falling film evaporation have been compared with the experimental heat transfer coefficients obtained from this research. Experiments with water as the evaporated fluid have been performed to validate the equipment and the method used. The coefficients obtained are mostly within ± 10 % of those calculated from the correlation for heat transfer in falling film evaporation from Schnabel and Schlünder (1980). Experiments with black liquor as the evaporated fluid have been performed. To be able to compare the experimental results with correlations from other experiments, a crucial factor is the black liquors viscosity, which decreased during the experiments because of its exposure to thermal treatment. Measurements with a laboratory rheometer indicated that the considered black liquor is non-Newtonian. The viscosity measured with an inline viscometer could for some conditions be less than one third of the viscosity of the black liquor falling film, due to different shear rates. Taken this into account, the correlation by Numrich (1995) agrees best with the experimental values for evaporation of black liquor with higher circulation flows and moderate viscosities. For high viscosities, at Prandtl numbers above 52, there are no valid correlations to compare the experimental results with. However, extrapolation of the correlations by Chun and Seban (1971) and Schnabel and Schlünder (1980) leads to values that are closest to our sparse experimental results under these conditions.
|
|
| 49. |
- Johansson, Miriam, 1978, et al.
(författare)
-
Falling film hydrodynamics of black liquor under evaporative conditions
- 2009
-
Ingår i: International Journal of Heat and Mass Transfer. - : Elsevier BV. - 0017-9310. ; 2009:52, s. 2769-2778
-
Tidskriftsartikel (refereegranskat)abstract
- Bubbles were observed in a thin, evaporating, falling film of black liquor (a fluid mixture generated during the pulp production) on the exterior wall of a research evaporator. Because the presence of bubbles could not be explained by nucleate boiling, a combination of turbulent vapour entrainment and effects due to surface-active compounds – surfactants – is proposed. Black liquor contains numerous surfactants, which are likely to enhance bubble formation and stabilization in the fluid and on the film interface. One observed important effect of bubble formation was fluid loss due to bubble-bursting aerosolization (sputtering). Also, bubbles and bubble processes probably alter the film velocity-profile and heat transfer resistance, thereby affecting heat transfer across the film and hence evaporator efficiency.
|
|
| 50. |
- Johansson, Miriam, 1978, et al.
(författare)
-
Heat transfer in evaporating black liquor falling film
- 2009
-
Ingår i: International Journal of Heat and Mass Transfer. - : Elsevier BV. - 0017-9310. ; 2009:52, s. 2759-2768
-
Tidskriftsartikel (refereegranskat)abstract
- Black liquor is a fluid with high viscosity, implying high Pr numbers. Most of the previously developed correlations for falling film evaporation heat transfer were developed for fluids with relatively low Pr numbers, and therefore are not valid for most black liquor evaporation conditions. Experimental heat transfer data from black liquor evaporation are presented here. They show that the Nu number, as expected, increases in the turbulent region. However, at a specific Re number for each Pr number level, the Nu number ceases to increase with increasing Re number. A new correlation, taking this observation into account, has been developed on the basis of experimental data in the region of 4.7
|
|
