| 1. |
- Broström, Markus, 1977-, et al.
(författare)
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Sulfation of corrosive alkali chlorides by ammonium sulfate in a biomass fired CFB boiler
- 2007
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Ingår i: Fuel processing technology. - Amsterdam : Elsevier Bv. - 0378-3820 .- 1873-7188. ; 88:11-12, s. 1171-1177
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Tidskriftsartikel (refereegranskat)abstract
- Biomass and waste derived fuels contain relatively high amounts of alkali and chlorine, but contain very little sulfur. Combustion of such fuels can result in increased deposit formation and superheater corrosion. These problems can be reduced by using a sulfur containing additive, such as ammonium sulfate, which reacts with the alkali chlorides and forms less corrosive sulfates. Ammonium sulfate injection together with a so-called in situ alkali chloride monitor (IACM) is patented and known as "ChlorOut". IACM measures the concentrations of alkali chlorides (mainly KCl in biomass combustion) at superheater temperatures. Tests with and without spraying ammonium sulfate into the flue gases have been performed in a 96MW(th)/25MW(e) circulating fluidized bed (CFB) boiler. The boiler was fired mainly with bark and a chlorine containing waste. KCl concentration was reduced from more than 15 ppm to approximately 2 ppm. during injection of ammonium sulfate. Corrosion probe measurements indicated that both deposit formation and material loss due to corrosion were decreased using the additive. Analysis of the deposits showed significantly higher concentration of sulfur and almost no chlorine in the case with ammonium sulfate. Results from impactor measurements supported that KCl was sulfated to potassium sulfate by the additive. (C) 2007 Elsevier B.V. All rights reserved.
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| 2. |
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| 3. |
- Cervenka, Simon, et al.
(författare)
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Associations between dopamine D2-receptor binding and cognitive performance indicate functional compartmentalization of the human striatum
- 2008
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Ingår i: NeuroImage. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 1053-8119 .- 1095-9572. ; 40:3, s. 1287-1295
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Tidskriftsartikel (refereegranskat)abstract
- Based on pharmacological, neuroanatomical, and lesion studies in animals, a functional compartmentalization of the striatal complex has been proposed. However, this has not been convincingly demonstrated in human subjects. Most functions ascribed to the striatum have been linked to its dense dopaminergic innervation, from motor control to higher-order brain functions ( e. g., cognition), making the dopamine system a suitable probe for striatal function. Limbic striatum, a region involved in reward processing, has recently been implicated also in episodic memory function. Here we examined striatal dopamine D2-receptor binding in 16 healthy subjects using PET and the radioligand [C-11] raclopride, in relation to cognitive performance. Receptor availability in limbic striatum was related to performance in tests of episodic memory, but not to tests of verbal fluency and general knowledge. By contrast, D2 binding in associative and sensorimotor striatum was less strongly related to episodic memory, but showed associations to the non-episodic tasks. These findings provide biochemical evidence for a functional compartmentalization of human striatum, and serve as a starting point for a more detailed investigation of striatal biomarkers in the normal brain as well as in neurodegenerative disorders. (c) 2008 Elsevier Inc. All rights reserved.
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| 4. |
- Fanta, Samuel, et al.
(författare)
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Pharmacogenetics of cyclosporine in children suggests an age-dependent influence of ABCB1 polymorphisms
- 2008
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Ingår i: Pharmacogenetics and genomics. - 1744-6872. ; 18:2, s. 77-90
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To evaluate whether variations in the ABCB1, ABCC2, SLCO1B1, CYP3A4, CYP3A5, or NR1I2 genes are associated with the pharmacokinetics of cyclosporine in pediatric renal transplant candidates, and whether the effects of these variants are related to age. METHODS: A total of 104 pediatric patients (aged 0.36-16.3 years) were genotyped for 17 putatively functionally significant sequence variations in the ABCB1, SLCO1B1, ABCC2, CYP3A4, CYP3A5, and NR1I2 genes. The patients had undergone a pharmacokinetic study with intravenous and oral ciclosporine (INN, cyclosporin) before renal transplantation. RESULTS: In the whole population, the mean+/-SD cyclosporine oral bioavailability was 0.38+/-0.09, volume of distribution was 2.3+/-0.54 l/kg, and systemic clearance normalized by allometric body weight was 0.88+/-0.16 l/h/kg3/4. The prehepatic extraction ratio was 0.51+/-0.13, and the hepatic extraction ratio was 0.24+/-0.04, the former explaining 95% of the variability in oral bioavailability (P<0.0001). In children older than 8 years, the pre-hepatic extraction was 0.64+/-0.09 in those with the ABCB1 c.2677GG genotype, 0.52+/-0.11 in those with the c.2677GT genotype, and 0.41+/-0.03 in those with the c.2677TT genotype (P=0.021, r2=0.334), leading to corresponding differences in oral bioavailability (0.28+/-0.07, 0.36+/-0.07, and 0.44+/-0.04, respectively; P=0.012, r2=0.372). Similar associations were observed with the ABCB1 c.1236C>T variant and the related haplotype c.1199G-c.1236C-c.2677G-c.3435C (P<0.05). The estimated oral dose requirement and clearance of cyclosporine remained largely unexplained by the genetic variations. CONCLUSIONS: Although these data suggest an age-related effect of ABCB1 polymorphism on oral bioavailability, further studies are required on the predictive value of genotyping for individualization of cyclosporine dosing in children.
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| 5. |
- Forsberg, Christer, et al.
(författare)
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Principle, calibration, and application of the in situ alkali chloride monitor
- 2009
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Ingår i: Review of Scientific Instruments. - : American Institute of Physics. - 0034-6748 .- 1089-7623. ; 80:2, s. 023104-1-023104-4
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Tidskriftsartikel (refereegranskat)abstract
- The extended use of biomass for heat and power production has caused increased operational problems with fouling and high-temperature corrosion in boilers. These problems are mainly related to the presence of alkali chlorides (KCl and NaCl) at high concentrations in the flue gas. The In-Situ Alkali Chloride Monitor (IACM) was developed by Vattenfall Research and Development AB for measuring the alkali chloride concentration in hot flue gases (>650 oC). The measurement technique is based on molecular differential absorption spectroscopy in the UV range. Simultaneous measurement of SO2 concentration is also possible. The measuring range is 1-50 ppm for the sum of KCl and NaCl concentrations, and 4-750 ppm for SO2. This paper describes the principle of the IACM as well as its calibration. Furthermore, an example of its application in an industrial boiler is given.
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| 6. |
- Lindqvist, Per, et al.
(författare)
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Pulsed tissue Doppler and strain imaging discloses early signs of infiltrative cardiac disease: a study on patients with familial amyloidotic polyneuropathy.
- 2006
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Ingår i: Eur J Echocardiogr. ; 7:1, s. 22-30
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Familial amyloidotic polyneuropathy (FAP) is a hereditary systemic amyloidosis with cardiac involvement. As early identification of the cardiac involvement is of major clinical interest we performed this study to test the hypothesis that tissue Doppler imaging (TDI) and strain imaging (SI) might disclose cardiac involvement in patients with early stages of FAP. METHODS: Twenty-two patients with FAP and 36 healthy controls were studied. Standard M-mode and Doppler echocardiography were performed. TDI and SI were used to assess the regional longitudinal left ventricular (LV) lateral and septal and right ventricular (RV) wall functions. All time intervals were corrected for heart rate by dividing with R-R interval and presented as percentage. RESULTS: We found that patients in comparison with controls had increased LV and RV wall thickness and by using TDI a prolonged isovolumic relaxation time (IVRt) at the septal segment (15.0+/-7.0 vs 10.7+/-4.1%, p<0.05) and prolonged isovolumic contraction time (IVCt) at LV lateral (12.8+/-4.3 vs 10.1+/-3.3%, p<0.05), septal (12.5+/-3.5 vs 8.9+/-1.9%, p<0.001) and RV free wall segments (12.0+/-3.6 vs 8.3+/-2.1%, p<0.001). Strain was reduced at LV lateral basal segment (-4.6+/-14.0 vs -20.2+9.1, p<0.001), RV free wall mid segment (-16.2+/-12.8 vs -29.4+/-15.2) as well as both septal segments (-4.1+/-11.7 vs -16.2+/-9.0%, p<0.001, -8.8+/-11.5 vs -19.4+/-8.4%, p<0.001 for septal basal and mid-segment). Even in the absence of septal hypertrophy the septal strain was reduced and the regional IVCt was prolonged. CONCLUSIONS: This is the first clinical study using TDI and strain in patients with FAP showing functional abnormalities before any morphological echocardiographic abnormalities were present. Both the left and right heart functions are involved and the disease should therefore be regarded as biventricular.
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| 7. |
- Malm, Jan, et al.
(författare)
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Computer angiography and ultrasound equally good in the examination of carotid artery. The Carotis Center should have access to both
- 2009
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Ingår i: Läkartidningen. - 0023-7205 .- 1652-7518. ; 106:12, s. 850-853
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Ultraljud av halskärl är i dag den viktigaste metoden för bestämning av stenosgrad i karotiskärlen. Förbättrad teknik gör DT- angiografi till ett möjligt alternativ. Det finns en god överensstämmelse mellan metoderna; även höggradig stenos och ocklusion avbildas korrekt. Karotisopererande centrum bör använda båda metoderna, eftersom de är kompletterande. Remitterande centrum kan själva välja vilken metod man använder – den undersökning som kan utföras snarast efter TIA eller stroke bör prioriteras. Man bör validera sin egen metod, oavsett om man använder ultraljud eller DT-angiografi, eftersom operationsindikationen är beroende av undersökningsresultatet.
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