| 11. |
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| 12. |
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| 13. |
- Öhman, Marcus, et al.
(författare)
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Bed agglomeration characteristics during fluidized bed combustion of biomass fuels
- 2000
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Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 14:1, s. 169-178
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Tidskriftsartikel (refereegranskat)abstract
- The in-bed behavior of ash-forming elements in fluidized bed combustion (FBC) of different biomass fuels was examined by SEM/EDS analysis of samples collected during controlled agglomeration test runs. Eight fuels were chosen for the test. To cover the variations in biomass characteristics and to represent as many combinations of ash-forming elements in biomass fuels as possible, the selection was based on a principal-component analysis of some 300 biomass fuels, with respect to ash-forming elements. The fuels were then combusted in a bench-scale fluidized bed reactor (5 kW), and their specific agglomeration temperatures were determined. Bed samples were collected throughout the tests, and coatings and necks formed were characterized by SEM/EDS analyses. On the basis of their compositions, the corresponding melting behaviors were determined, using data extracted from phase diagrams. The bench-scale reactor bed samples were finally compared with bed samples collected from biomass-fired full-scale fluidized bed boilers. In all the analyzed samples, the bed particles were coated with a relatively homogeneous ash layer. The compositions of these coatings were most commonly constricted to the ternary system K2O-CaO-SiO2. Sulfur and chlorine were further found not to `participate' in the agglomeration mechanism. The estimated melting behavior of the bed coating generally correlated well with the measured agglomeration temperature, determined in the 5 kW bench-scale fluidized bed reactor. Thus, the results indicate that partial melting of the coating of the bed particles would be directly responsible for the agglomeration.
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| 14. |
- Lowe, Michael R., et al.
(författare)
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The length of the CTLA-4 microsatellite (AT)(N)-repeat affects the risk for type 1 diabetes
- 2000
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Ingår i: Autoimmunity. - : Informa UK Limited. - 0891-6934 .- 1607-842X. ; 32:3, s. 173-180
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Tidskriftsartikel (refereegranskat)abstract
- CTLA-4 is important to down-regulating T cell responses and has been implicated in type 1 (insulin dependent) diabetes mellitus in both linkage and association studies. The aim of our study was to relate the polymorphic (AT)(n) microsatellite in the 3' untranslated sequence of the CTLA-4 gene to diabetes risk. We studied 616 consecutively diagnosed 0-34 year-old Swedish patients and 502 matched controls by PCR-based genotyping to determine the length of the 3'-end (AT)(n)repeat region of the CTLA-4 gene and categorizing alleles as predominantly monomorphic short (S) or highly polymorphic (in length) long (L) alleles. The odds of type 1 diabetes of subjects with the L/L genotype was estimated to be 1.84 times that of subjects with the S/S genotype (95% CI 1.44-2.73, p=0.002). Further analysis of the long alleles, partitioned into intermediate (I) length and very long (VL) alleles, suggested that L alleles act recessively in conferring diabetes risk (p=0.0009). This study suggests that the 3'-end (AT)(n) repeat region of the CTLA-4 gene represents a recessive risk factor for type 1 diabetes.
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| 15. |
- Ahlm, Clas, 1956-, et al.
(författare)
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Serologic evidence of Puumala virus infection in wild moose in northern Sweden
- 2000
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Ingår i: American Journal of Tropical Medicine and Hygiene. - : American Society of Tropical Medicine and Hygiene. - 0002-9637 .- 1476-1645. ; 62:1, s. 106-111
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Tidskriftsartikel (refereegranskat)abstract
- Puumala (PUU) virus is the causative agent of nephropathia epidemica, the Scandinavian form of hemorrhagic fever with renal syndrome. The infection is acquired by airborne transmission of PUU virus from its rodent reservoir, the bank vole. Besides serologic data indicating that the virus may spread also to heterologous rodents, there is little information on the susceptibility of wild living animals to PUU virus. We studied the occurrence of antibodies to PUU virus in serum samples from 427 wild-living moose, of which 260 originated from the PUU virus-endemic northern and central parts of Sweden and 167 originated from the southern, nonendemic part of Sweden. Samples from 5 animals showed reactivity in an ELISA for recombinant PUU virus nucleocapsid protein, an immunofluorescent assay, and a neutralization test. These 5 animals all originated from the PUU virus-endemic northern part of Sweden. In conclusion, 5 of 260 moose from the endemic region showed convincing serologic evidence of past PUU virus infection. The seroprevalence was low, suggesting that the moose is subjected to endstage infection rather than being part of an enzootic transmission cycle.
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| 16. |
- Alfredson, Håkan, et al.
(författare)
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In vivo investigation of ECRB tendons with microdialysis technique--no signs of inflammation but high amounts of glutamate in tennis elbow.
- 2000
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Ingår i: Acta Orthopaedica Scandinavica. - : Medical Journals Sweden AB. - 0001-6470. ; 71:5, s. 475-479
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Tidskriftsartikel (refereegranskat)abstract
- We used the microdialysis technique to study concentrations of substances in the extensor carpi radialis brevis (ECRB) tendon in patients with tennis elbow. In 4 patients (mean age 41 years, 3 men) with a long duration of localized pain at the ECRB muscle origin, and in 4 controls (mean age 36 years, 2 men) with no history of elbow pain, a standard microdialysis catheter was inserted into the ECRB tendon under local anesthesia. The local concentrations of the neurotransmitter glutamate and prostaglandin E2 (PGE2) were recorded under resting conditions. Samplings were done every 15 minutes during a 2-hour period. We found higher mean concentrations of glutamate in ECRB tendons from patients with tennis elbow than in tendons from controls (215 vs. 69 micromoL/L, p < 0.001). There were no significant differences in the mean concentrations of PGE2 (74 vs. 86 pg/mL). In conclusion, in situ microdialysis can be used to study certain metabolic events in the ECRB tendon of the elbow. Our findings indicate involvement of the excitatory neurotransmitter glutamate, but no biochemical signs of inflammation (normal PGE2 levels) in ECRB tendons from patients with tennis elbow.
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| 17. |
- Andersson, Christer, 1945-, et al.
(författare)
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The W198X and R173W mutations in the porphobilinogen deaminase gene in acute intermittent porphyria have higher clinical penetrance than R167 : a populations-based study
- 2000
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Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - : Informa UK Limited. - 0036-5513 .- 1502-7686. ; 60:7, s. 643-648
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Tidskriftsartikel (refereegranskat)abstract
- The biosynthesis of porphyrins is one of the most conserved parthways known, about the same sequence of reactions taking place in all species. By associating different metals, porphyrins give rise to the “pigments of life”: chlorophyll, haem and cobalamin. The unique tetrapyrrolic structure enables it to function in an array of reactions as a single electron carrier and as a catalyst for redox reactions. In this capacity, it constitutes the prosthetic group of enzymes participating in cellular respiration, in conversion reactions involving steroids and lipophilic xenobiotics, in protective mechanisms directed against oxidative stress and in pathways providing central messenger molecules. The formation of haem is accomplished by a sequence of eight dedicated enzymes encoded by different genes, some being active in ubiquitous as well as in erythroid isoforms. Large differences between the participating enzymes with regard to catalytic power, with low capacity steps positioned early in the catalytic chain, constitute a bar against substrate overloading of enzymes processing porphyrins, thus preventing accumulation in the body of these phototoxic compounds under physiological conditions. Most of the haem in the body is produced by the liver and bone marrow, but the mechanisms applied for the control of the synthesis differ between the two organs. The extremely potent hemeprotein enzymes formed in the liver are rapidly turned over in response to current metabolic needs. They have half-lives in the order of minutes or hours and are restored by fast-acting mechanisms for the de novo synthesis, when needed. Uninterrupted and instant availability of the compound is secured by acute deinhibition of the initial enzyme of the synthetic chain, ubiquitous 5-aminolevulinate synthase (ALAS-1), in response to drain of the free cellular haem pool caused by prevailing demands for hemeproteins or by increased catabolism of the compound. In contrast, in the erythroid progenitor cell the haem synthetic machinery is designed for uninterrupted production of huge amounts of haem for combination with globin chains to form hemoglobin at a steady rate. In the erythron the synthesis of the enzymes participating in the formation of haem is under control of erythropoietin, formed under hypoxic conditions. In the absence of iron, to be incorporated in the porphyrin formed in the last step of the synthesis, the mRNA of erythroid 5-aminolevulinate synthase (ALAS-2) is blocked by attachment of an iron-responsive element (IRE) binding cytosolic protein, and transcription of this key enzyme is inhibited. In humans, the genes for each of the haem synthetic enzymes may become the target of mutations that give rise to impaired cellular enzyme activity. Seven of the enzyme deficiencies are associated with accumulation of toxic intermediaries and with disease entities termed porphyrias. The acute porphyrias are characterized by attacks of neuropsychiatric symptoms, which may be due to a toxic surplus of the porphyrin presursor 5-aminolevulinic acid, or a consequence of a deficit of vital hemeproteins resulting from impaired synthesis of haem. In the cutaneous porphyrias, impairment of enzymatic steps where porphyrins are processed gives rise to solar hypersensitivity due to accumulation of phototoxic porphyrins in the skin. Early diagnosis, information to the patient regarding the nature of the illness and counselling aimed at avoidance of triggering factors are cornerstones in the handling of the porphyric diseases. Gene analysis is of incomparable diagnostic reliability in carrier detection, but biochemical methods must be applied in the important task of monitoring porphyric disease activity. In most forms of porphyria the gene carriers run the risk of development of associated diseases in liver or kidneys, a circumstance that prompts application of well-structured surveillance programs.
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| 18. |
- Andersson, T, et al.
(författare)
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Community-based prevention of perinatal deaths : lessons from nineteenth-century Sweden.
- 2000
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Ingår i: International Journal of Epidemiology. - : Oxford University Press (OUP). - 0300-5771 .- 1464-3685. ; 29:3, s. 542-8
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Tidskriftsartikel (refereegranskat)abstract
- Poor reproductive history, particularly previously high perinatal mortality, is associated with high perinatal mortality. Midwifery-assisted at home deliveries successfully reduced perinatal mortality.
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| 19. |
- Andersson, T, et al.
(författare)
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Swedish maternal mortality in the 19th century by different definitions : previous stillbirths but not multiparity risk factor for maternal death.
- 2000
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Ingår i: Acta Obstetricia et Gynecologica Scandinavica. - : Wiley. - 0001-6349 .- 1600-0412. ; 79:8, s. 679-86
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Tidskriftsartikel (refereegranskat)abstract
- In conclusion, this study shows that the mother's reproductive history was the most important risk factor measured for all definitions of maternal death. Grand multiparity did not increase the risk of maternal death. Maternal mortality ratio varied threefold in the study population, depending on the definition used. The high mortality ratios found in this study, only declining by the end of the century, should be interpreted as a general condition of the society since no significant differences could be perceived regarding social class, while unmarried women were more at risk.
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| 20. |
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