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- Eriksson, Magnus, et al.
(författare)
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Variations in the rheology and penetrability of cement-based grouts : an experimental study
- 2004
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Ingår i: Cement and Concrete Research. - : Elsevier BV. - 0008-8846 .- 1873-3948. ; 34:7, s. 1111-1119
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Tidskriftsartikel (refereegranskat)abstract
- To ascertain the most suitable grouting mixture to use in a specific project or to facilitate making predictions about grouting outcomes, laboratory tests are usually carried out to determine the properties of the particular grout. This paper presents a number of measurements of grout properties relating to the rheology and penetrability of fresh cement-based grout. The main purpose of this study is to investigate and describe variations that can be detected when measurements of these grout parameters are carried out repeatedly. Furthermore, a number of additional factors that can also influence these grout properties have been identified and examined. This study has shown that grout properties do vary and should therefore not to be regarded as uniform. The rheology-related properties of grout have been found to vary more than the penetrability-related parameters. Furthermore, it was found that the water-cement (w/c) ratio, the cement condition, and the mixing equipment could significantly influence the grout properties investigated in this study. Based on these experimental findings, it is therefore recommended that repeated testing be carried out on a specific grout mixture in preference to relying on the results of a single test.
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- Steward, C. G., et al.
(författare)
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Severe pulmonary hypertension: a frequent complication of stem cell transplantation for malignant infantile osteopetrosis
- 2004
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Ingår i: Br J Haematol. - 0007-1048. ; 124:1, s. 63-71
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Tidskriftsartikel (refereegranskat)abstract
- This report describes eight infants who developed acute severe pulmonary arterial hypertension (PAH) at days -2 to +89 after allogeneic stem cell transplantation (SCT) for malignant infantile osteopetrosis (MIOP). They were taken from a total of 28 children (frequency 29%) transplanted for this disease at three institutions between 1996 and 2002. Typical presentations were acute dyspnoea, hypoxia and brady/tachycardia usually in the absence of fever, crepitations or other evidence of infection. Six patients (75%) required assisted ventilation and five (62%) died. There was clinical or pathological evidence of veno-occlusive disease (VOD) in three children, but absence of VOD in the remaining five suggests that a separate disease process may be responsible for the PAH. Responses to nitric oxide (NO), defibrotide (DF), nicardipine and steroids in varying combinations were disappointing. Three children showed sustained improvement after administration of epoprostenol (EP, prostacyclin) in conjunction with NO and/or DF and remain well and free of PAH 25, 31 and 32 months post-transplant. PAH must therefore be excluded in any child who becomes acutely breathless after SCT for osteopetrosis.
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- Wagner, C A, et al.
(författare)
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Effects of the serine/threonine kinase SGK1 on the epithelial Na(+) channel (ENaC) and CFTR : implications for cystic fibrosis.
- 2001
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Ingår i: Cellular Physiology and Biochemistry. - 1015-8987 .- 1421-9778. ; 11:4
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Tidskriftsartikel (refereegranskat)abstract
- Cystic fibrosis (CF) is characterized by impaired Cl(-) secretion and increased Na(+) reabsorption in several tissues including respiratory epithelium. Many CFTR mutations have been identified over the past years. However, only a poor correlation between the genotype and lung phenotype was found suggesting additional factors influencing the phenotype and course of the disease. The serine/threonine kinase SGK1 has recently been shown to stimulate the activity of the epithelial Na(+) channel ENaC. A variety of stimuli such as aldosterone, cell shrinkage, insulin or TGF-beta1 stimulate transcription and activate the SGK1 kinase. Here we further examined the effects of SGK1 on ENaC and CFTR which have mutual interactions and we analyzed sgk1 mRNA abundance in lung tissue from CF patients. Coexpression of CFTR and h-SGK1 in Xenopus oocytes increased ENaC currents as previously described. In addition CFTR mediated currents were also stimulated. h-SGK1 accelerated the expression of the amiloride sensitive Na(+)- current in Xenopus oocytes paralleled by increased ENaC-protein abundance in the oocyte membrane, an effect which was reversed by a h-SGK1(K127R) mutation lacking the ATP-binding site. The cation selectivity or Na(+) affinity were not affected. However, coexpression of h-SGK1 with ENaC altered the sensitivity of the Na(+)-channel to the inhibitors amiloride and triamterene. The inhibitory effect of CFTR expression on ENaC current was not affected by coexpression of h-SGK1 in Xenopus oocytes. Lung tissue from CF patients strongly expressed the serine/threonine kinase h-sgk1 which was not the case for non-CF lung tissue. Loss of CFTR function itself in a CF lung epithelial cell line did not increase SGK1 expression. In summary, enhanced expression of h-SGK1 in epithelial cells of CF-lung tissue may be a novel pathophysiological factor contributing to increased Na(+) channel activity and thus to increased Na(+) transport in CF.
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