| 1. |
- Bajor, Antal, 1962, et al.
(författare)
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Normal or increased bile acid uptake in isolated mucosa from patients with bile acid malabsorption.
- 2006
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Ingår i: Eur J Gastroenterol Hepatol. - 0954-691X. ; 18:4, s. 397-403
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Bile acid malabsorption as reflected by an abnormal 75Se-labelled homocholic acid-taurine (75SeHCAT) test is associated with diarrhoea, but the mechanisms and cause-and-effect relations are unclear. Objectives: Primarily, to determine whether there is a reduced active bile acid uptake in the terminal ileum in patients with bile acid malabsorption. Secondarily, to study the linkage between bile acid malabsorption and hepatic bile acid synthesis. Methods: Ileal biopsies were taken from patients with diarrhoea and from controls with normal bowel habits. Maximal active bile acid uptake was assessed in ileal biopsies using a previously validated technique based on uptake of 14C-labelled taurocholate. To monitor the hepatic synthesis, 7[alpha]-hydroxy-4-cholesten-3-one, a bile acid precursor, was assayed in blood. The 75SeHCAT-retention test was used to diagnose bile acid malabsorption. Results: The taurocholate uptake in specimens from diarrhoea patients was higher compared with the controls [median, 7.7 (n=53) vs 6.1 [mu]mol/g per min (n=17)] (P<0.01) but no difference was seen between those with bile acid malabsorption (n=18) versus diarrhoea with a normal 75SeHCAT test (n=23). The 75SeHCAT values and 7[alpha]-hydroxy-4-cholesten-3-one were inversely correlated. Conclusions: The data do not support bile acid malabsorption being due to a reduced active bile acid uptake capacity in the terminal ileum. (C) 2006 Lippincott Williams & Wilkins, Inc.
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| 2. |
- Böhlenius, Henrik, et al.
(författare)
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Biomass production and fuel characteristics from long rotation poplar plantations
- 2023
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Ingår i: Biomass and Bioenergy. - : Elsevier Ltd. - 0961-9534 .- 1873-2909. ; 178
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Tidskriftsartikel (refereegranskat)abstract
- One of the key elements in this transition is the securing of a large supply of sustainable biomass. In this study, the feedstock potential of long rotation poplar plantations (12–30 years with diameter of 15 of 30 cm) was determined and the properties of poplar biomass fuel were analyzed with the aim of using thermochemical conversion methods to produce biofuel. Our results demonstrate that Sweden has great potential for producing biofuels from long rotation poplar plantations, with a total of 1.8 million hectares (ha) consisting of arable (0.5 million ha) and forested arable land (1.3 million ha). Based on available land and biomass production potential, our results indicate that 10 million Mg DW could be produced annually. Regions in mid/southern Sweden have the largest potential (larger areas and higher biomass production. Our results further suggest that poplar biomass from these plantations has fuel characteristics similar to forest fuels from other conifer tree species, making the biomass suitable as feedstock for biofuel production based on thermochemical conversion methods. If 25% of the available land were used, 7.6 TWh methanol biofuels could be produced annually from 16 biofuel plants, using 160,000 Mg DW yr−1, primarily located in the southern part of Sweden. Two counties (Skåne and Västra Götaland) would be able to support their biofuel plants using poplar plantations as feedstock. Stable biofuel production in the other counties would depend on collaborating with neighboring counties.
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| 3. |
- Forshammar, Johan, et al.
(författare)
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A pilot study of colonic B cell pattern in irritable bowel syndrome
- 2008
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 43:12, s. 1461-6
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Low-grade gastrointestinal inflammation has been reported in patients with irritable bowel syndrome (IBS). However, the colonic B-cell pattern has not been investigated in these patients. Therefore, the aim of this pilot study was to investigate the distribution and isotype of immunoglobulin-producing B cells in the colonic mucosa of IBS patients. MATERIAL AND METHODS: Patients with IBS (n=12) fulfilling the Rome II criteria were compared with controls (n=11). Immunohistochemical staining of biopsies from the sigmoid and ascending colon was performed. RESULTS: The number of IgA(+) B cells in the ascending colon was lower in IBS patients than in controls (p=0.039). Furthermore, unlike controls, IBS patients had a reduction of IgA(+) B cells in the ascending colon relative to the sigmoid colon (p=0.04). Neither the IgG(+), nor the IgM(+) colonic B-cell numbers differed between IBS patients and controls. Very few colonic IgE(+) cells were detected and there was no difference between the two subject groups. CONCLUSIONS: The reduced number of colonic IgA(+) B cells in IBS patients suggests that the disorder may be associated with a modified gut immune defence. Whether this phenomenon is causally related to symptoms remains unknown and merits further investigation in a larger group of patients.
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| 4. |
- Lasson, Anders, et al.
(författare)
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Fecal Calprotectin Levels Predict the Clinical Course in Patients With New Onset of Ulcerative Colitis
- 2013
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Ingår i: Inflammatory Bowel Diseases. - 1078-0998. ; 19:3, s. 576-581
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The clinical course of ulcerative colitis (UC) is unpredictable. During recent years, the ability of fecal biomarkers to predict relapse in inflammatory bowel disease has been evaluated. The objective of this study was to assess fecal calprotectin (FC) as a predictor of disease recurrence in patients with new onset of UC. METHODS: Sixty-nine patients were included. After the initial treatment, patients were followed up after 3 months and then yearly for 3 years. The prognostic role of FC 3 months after the initial therapy was evaluated. RESULTS: The FC levels 3 months after the diagnosis were higher in patients experiencing a relapsing disease course compared with those with a mild disease course during 1 year (median, 263; interquartile range [IQR], 100-634 μg/g versus median, 102; IQR, 38-225 μg/g; P = 0.009) and 3 years of follow-up (median, 280; IQR, 102-622 μg/g versus median, 118; IQR, 39-219 μg/g; P = 0.01). The area under the receiver operating characteristic curves using calprotectin to predict a relapsing disease course during 1 year and 3 years were 0.69 (95% confidence interval, 0.56-0.82) and 0.70 (95% confidence interval, 0.57-0.83), respectively. In the Kaplan-Meier survival analysis, a FC level >262 μg/g was associated with an increased risk of a relapsing disease course during the study period (P = 0.003). In logistic regression analysis, only FC and age were found to be independent predictors of having a relapsing disease course. CONCLUSIONS: Levels of FC 3 months after the initial therapy in patients with new onset of UC predict the disease course over the following years, and they are of value in the clinical management of these patients.
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| 5. |
- Lasson, Anders, et al.
(författare)
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Fecal calprotectin one year after ileocaecal resection for Crohn's disease - A comparison with findings at ileocolonoscopy.
- 2014
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Ingår i: Journal of Crohn's & colitis. - : Oxford University Press (OUP). - 1876-4479 .- 1873-9946. ; 8:8, s. 789-795
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Tidskriftsartikel (refereegranskat)abstract
- Ileocaecal resection for Crohn's disease is commonly performed. The severity of endoscopic lesions in the anastomotic area one year postoperatively is considered to reflect the subsequent clinical course. Fecal calprotectin (FC) has been shown to correlate with the findings at ileocolonoscopy in Crohn's disease. The objectives of this study were to assess whether the concentration of FC reflects the endoscopic findings one year after ileocaecal resection and to evaluate the variation of FC in individual patients during 6months prior to the ileocolonoscopy.
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| 6. |
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| 7. |
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| 8. |
- Xie, Bin, et al.
(författare)
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Development of an integrated thermal biosensor for the simultaneous determination of multiple analytes
- 1995
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Ingår i: The Analyst. - 0003-2654. ; 120:1, s. 155-160
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Tidskriftsartikel (refereegranskat)abstract
- A flow injection thermal microbiosensor was designed for the simultaneous determination of multiple analytes. The biosensor consisted of five thin-film thermistors which were located along a single microchannel. The device was fabricated on a quartz chip by micromachining. The feasibility of employing this system for the detection of two independent enzyme reactions was demonstrated using two different pairs of enzymes, urease-penicillinase and urease-glucose oxidase. The enzymes were immobilized on agarose beads, which were then sequentially packed into distinct regions of the microchannel. Using this method, samples containing urea mixed with penicillin V or with glucose were simultaneously analysed. Linear ranges of up to 20 mmol l-1 urea, 40 mmol l-1 penicillin V and 8 mmol l-1 glucose (saturated with O2) were obtained using a flow rate of 30 μl min-1 and a sample volume of 20 μl. The relative standard deviations for urea and penicillin V assays were 1.13 and 2.42% for the first 100 samples and 1.17 and 2.78% for 200 samples, respectively. The sensor is capable of analysing 25 samples per hour.
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| 9. |
- Xie, Bin, et al.
(författare)
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Microbiosensor based on an integrated thermopile
- 1994
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Ingår i: Analytica Chimica Acta. - : Elsevier BV. - 0003-2670. ; 299:2, s. 165-170
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Tidskriftsartikel (refereegranskat)abstract
- A microbiosensor based on an integrated thermopile was designed and fabricated on a quartz chip. The thermopile, which was manufactured by doping boron in polysilicon together with aluminium, provided a potential output of ca. 2 mV K. A silicone rubber membrane was used to form and seal the microchannel. The total column volume was 20 μl. Glucose oxidase and catalase were co-immobilized on spherical CPG beads (controlled pore glass) and in turn charged into the microchannel. Using 1 μl sample volumes, a linear range of 2 to 25 mM glucose was obtained using a flow rate of 105 μl min. The relative standard deviation for 100 glucose samples (10 mM) was 5%.
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| 10. |
- Öhman, Johan, 1973-
(författare)
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Upscaling of Flow, Transport, and Stress-effects in Fractured Rock
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- One of many applications of geohydraulic modelling is assessing the suitability of a site to host a nuclear waste repository. This modelling task is complicated by scale-dependent heterogeneity and coupled thermo-hydro-mechanical (THM) processes. The objective here was to develop methods for (i) upscaling flow and transport in fractured media from detailed-scale data and (ii) accounting for THM-induced effects on regional-scale transport. An example field data set was used for demonstration.A systematic framework was developed where equivalent properties of flow, transport, and stress-effects were estimated with discrete fracture network (DFN) modelling, at some block scale, and then transferred to a regional-scale stochastic continuum (SC) model. The selected block scale allowed a continuum approximation of flow, but not of transport. Instead, block-scale transport was quantified by transit time distributions and modelled with a particle random walk method at the regional scale.An enhanced SC-upscaling approach was developed to reproduce the DFN flow results more simply. This required: (i) weighting of the input well-test data by their conductivity-dependent test volumes and (ii) conductivity-dependent correlation structure. Interestingly, the best-fitting correlation structure resembled the density function of DFN transmissivities. Channelized transport, over distances exceeding the block scale, was modelled with a transport persistence length. A linear relationship was found between this persistence length and the macroscale dispersion coefficient, with a slope equal to a representative mean block-scale dispersion coefficient.A method was also developed to combine well-test data and rock-mechanical data in estimating fracture transmissivities, and its application was demonstrated.Finally, an overall sequential THM analysis was introduced allowing the estimation of the significance of waste-related thermo-mechanical (TM) effects on regional transport; here TM effects are calculated separately and their impact on fracture transmissivities were incorporated into the hybrid framework. For the particular case, their effects on regional-scale transport were small.
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| 11. |
- Öhman, Lena, 1967, et al.
(författare)
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T-cell activation in patients with irritable bowel syndrome.
- 2009
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Ingår i: The American journal of gastroenterology. - : Ovid Technologies (Wolters Kluwer Health). - 1572-0241 .- 0002-9270. ; 104:5, s. 1205-12
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Irritable bowel syndrome (IBS) has been found to be associated with low-grade immune activation in a subset of patients. We therefore investigated blood and colonic T-cell activity in IBS patients. METHODS: Blood samples were initially obtained from 74 IBS patients and 30 controls. Supplementary blood samples, to confirm data, were taken from another cohort (26 patients and 14 controls). In addition, colonic biopsies were taken from a third cohort (11 patients and 10 controls). Peripheral blood and colonic mononuclear cells were stimulated with anti-CD3/CD28 antibodies. Proliferation, cytokine secretion, and T-cell phenotype were investigated. IBS symptom severity was assessed. RESULTS: IBS patients displayed an activated phenotype with increased frequencies of blood T cells expressing CD69 and integrin beta7/HLA-DR. Anti-CD3/CD28-stimulated blood and colonic T cells from IBS patients proliferated less than T cells from controls. IBS patients had an increased polyclonally stimulated T-cell secretion of IL-1beta, which also weakly correlated with increased bowel habit dissatisfaction. Furthermore, despite normal frequencies of CD25high T cells in the blood of IBS patients, lower blood CD25high T-cell frequencies were modestly correlated with more bowel habit dissatisfaction and increased total IBS symptom severity. CONCLUSIONS: IBS patients have an increased frequency of activated T cells, demonstrated by the expression of activation markers and reduced proliferation in response to restimulation in vitro. The increased level of T-cell activation is consistent with the hypothesis of low-grade immune activation in IBS and may also be involved in symptom generation in IBS.
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