| 1. |
- Went, M, et al.
(författare)
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Author Correction: Identification of multiple risk loci and regulatory mechanisms influencing susceptibility to multiple myeloma
- 2019
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Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 10:1, s. 213-
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Tidskriftsartikel (refereegranskat)abstract
- The original version of this Article contained an error in the spelling of a member of the PRACTICAL Consortium, Manuela Gago-Dominguez, which was incorrectly given as Manuela Gago Dominguez. This has now been corrected in both the PDF and HTML versions of the Article. Furthermore, in the original HTML version of this Article, the order of authors within the author list was incorrect. The PRACTICAL consortium was incorrectly listed after Richard S. Houlston and should have been listed after Nora Pashayan. This error has been corrected in the HTML version of the Article; the PDF version was correct at the time of publication.
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| 2. |
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| 3. |
- Went, M, et al.
(författare)
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Identification of multiple risk loci and regulatory mechanisms influencing susceptibility to multiple myeloma
- 2018
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Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 9:1, s. 3707-
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies (GWAS) have transformed our understanding of susceptibility to multiple myeloma (MM), but much of the heritability remains unexplained. We report a new GWAS, a meta-analysis with previous GWAS and a replication series, totalling 9974 MM cases and 247,556 controls of European ancestry. Collectively, these data provide evidence for six new MM risk loci, bringing the total number to 23. Integration of information from gene expression, epigenetic profiling and in situ Hi-C data for the 23 risk loci implicate disruption of developmental transcriptional regulators as a basis of MM susceptibility, compatible with altered B-cell differentiation as a key mechanism. Dysregulation of autophagy/apoptosis and cell cycle signalling feature as recurrently perturbed pathways. Our findings provide further insight into the biological basis of MM.
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| 4. |
- Canovic, Sead, 1979, et al.
(författare)
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Microstructural Investigation of the Initial Oxidation of the FeCrAlRE Alloy Kanthal AF in Dry and Wet O-2 at 600 and 800 degrees C
- 2010
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Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 1945-7111 .- 0013-4651. ; 157:6, s. C223-C230
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Tidskriftsartikel (refereegranskat)abstract
- The FeCrAlRE (where RE is reactive element) alloy Kanthal AF was exposed isothermally at 600 and 800 degrees C for 72 h in dry O-2 and in O-2 with 10 vol % H2O. The mass gains were 3-5 times higher at the higher temperature. The presence of water vapor increased the oxidation rate at 800 degrees C, while no significant effect was observed at 600 degrees C. A thin two-layered oxide formed at 600 degrees C: an outer (Fe, Cr)(2)O-3 corundum-type oxide, containing some Al, and an inner, probably amorphous, Al-rich oxide. At 800 degrees C a two-layered oxide formed in both environments. The inner layer consisted of inward grown alpha-Al2O3. In dry O-2 the originally formed outward grown gamma-Al2O3 had transformed to alpha-Al2O3 after 72 h. Water vapor stabilized the outward grown gamma-Al2O3 and hence no transformation occurred after 72 h in humid environment. RE-rich oxide particles with varying composition (Y, Zr, and Ti) were distributed in the base oxide at both temperatures and in both environments. The RE-rich particles were separated from the alloy substrate by a layer of Al-rich oxide. At 800 degrees C the Y-rich RE particles were surrounded by thick oxide patches in both dry and humid O-2.
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| 5. |
- Ericson, K, et al.
(författare)
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Defective mismatch-repair in patients with multiple primary tumours including colorectal cancer
- 2003
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Ingår i: European Journal of Cancer. - 1879-0852. ; 39:2, s. 8-240
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Tidskriftsartikel (refereegranskat)abstract
- Individuals with an inherited predisposition to cancer development are at an increased risk of developing multiple tumours. Hereditary non-polyposis colorectal cancer (HNPCC) is one of the most common hereditary cancer syndromes and is estimated to account for approximately 2% of colorectal cancers. However, HNPCC individuals are at an increased risk of developing other tumour types such as cancers of the endometrium, urothelium and small intestine. We have utilised a population-based regional cancer registry to identify all patients with double primary colorectal cancers and at least one additional malignancy and characterised the tumour spectrum in this patient group. We subsequently selected those 47 individuals who had developed at least four malignancies, including two colorectal cancers, for studies of the tumour characteristics associated with HNPCC. In total, these individuals developed 209 tumours, 156 of which were successfully retrieved. Microsatellite instability (MSI), a phenomenon caused by defective mismatch-repair (MMR), was identified in 63/154 (41%) evaluable tumours with a MSI-high pattern in 59 and a MSI-low pattern in four tumours. All tumours were immunohistochemically stained for the MMR proteins MLH1 and MSH2, with loss of expression in 55/63 (87%) MSI tumours and in 2/89 (2%) microsatellite stable (MSS) tumours. This loss affected MLH1 in 24 tumours and MSH2 in 33 tumours. A concordant loss of expression for the same MMR protein in several tumours from the same individual, a pattern that strongly suggests an underlying germline MMR gene mutation, was found in 17/45 (38%) patients and affected MLH1 in 8 patients and MSH2 in 9 patients. We conclude that the development of multiple primary tumours, including synchronous or metachronous colorectal cancers, is associated with an increased frequency of MSI and loss of immunohistochemical expression of MLH1 and MSH2.
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| 6. |
- Kariminejad, A., et al.
(författare)
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TOR1A variants cause a severe arthrogryposis with developmental delay, strabismus and tremor
- 2017
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Ingår i: Brain. - : Oxford University Press (OUP). - 0006-8950 .- 1460-2156. ; 140:11, s. 2851-2859
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Tidskriftsartikel (refereegranskat)abstract
- Autosomal dominant torsion dystonia-1 is a disease with incomplete penetrance most often caused by an in-frame GAG deletion (p.Glu303del) in the endoplasmic reticulum luminal protein torsinA encoded by TOR1A. We report an association of the homozygous dominant disease-causing TOR1A p.Glu303del mutation, and a novel homozygous missense variant (p.Gly318Ser) with a severe arthrogryposis phenotype with developmental delay, strabismus and tremor in three unrelated Iranian families. All parents who were carriers of the TOR1A variant showed no evidence of neurological symptoms or signs, indicating decreased penetrance similar to families with autosomal dominant torsion dystonia-1. The results from cell assays demonstrate that the p.Gly318Ser substitution causes a redistribution of torsinA from the endoplasmic reticulum to the nuclear envelope, similar to the hallmark of the p.Glu303del mutation. Our study highlights that TOR1A mutations should be considered in patients with severe arthrogryposis and further expands the phenotypic spectrum associated with TOR1A mutations.
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| 7. |
- Mitchell, Jonathan S., et al.
(författare)
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Genome-wide association study identifies multiple susceptibility loci for multiple myeloma
- 2016
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Multiple myeloma (MM) is a plasma cell malignancy with a significant heritable basis. Genome-wide association studies have transformed our understanding of MM predisposition, but individual studies have had limited power to discover risk loci. Here we perform a meta-analysis of these GWAS, add a new GWAS and perform replication analyses resulting in 9,866 cases and 239,188 controls. We confirm all nine known risk loci and discover eight new loci at 6p22.3 (rs34229995, P = 1.31 x 10(-8)), 6q21 (rs9372120, P = 9.09 x 10(-15)), 7q36.1 (rs7781265, P = 9.71 x 10(-9)), 8q24.21 (rs1948915, P = 4.20 x 10(-11)), 9p21.3 (rs2811710, P = 1.72 x 10(-13)), 10p12.1 (rs2790457, P = 1.77 x 10(-8)), 16q23.1 (rs7193541, P = 5.00 x 10(-12)) and 20q13.13 (rs6066835, P = 1.36 x 10(-13)), which localize in or near to JARID2, ATG5, SMARCD3, CCAT1, CDKN2A, WAC, RFWD3 and PREX1. These findings provide additional support for a polygenic model of MM and insight into the biological basis of tumour development.
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| 8. |
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| 9. |
- Shahabi-Navid, M., et al.
(författare)
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Localized Atmospheric Corrosion of Magnesium-Aluminum Alloys Produced by Semisolid Casting: A 2D and 3D Investigation
- 2021
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Ingår i: Corrosion. - : NACE International. - 0010-9312 .- 1938-159X. ; 77:2, s. 242-253
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Tidskriftsartikel (refereegranskat)abstract
- The localized corrosion of the two magnesium-aluminum alloys AM50 and AZ91 produced by a semisolid casting method was investigated under atmospheric corrosion conditions, in the presence of NaCl. Gravimetry confirmed the beneficial effect from ambient levels of carbon dioxide (CO2) in suppressing corrosion through the formation of magnesium hydroxy carbonates. Both 2D and 3D characterization revealed that ambient CO2 has a strong influence on the morphology and rate of localized corrosion. In CO2-free atmosphere, the alloys suffered localized corrosion resulting in clustered and interconnected cavities that extended deep into the material. In contrast, corrosion in the presence of ambient levels of CO2 (400 ppm) resulted in evenly distributed shallow corrosion sites. The results indicate that CO2 neutralizes the cathodic areas resulting in diminished cathodic activity and inhibiting NaCl(aq) droplet coalescence.
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| 10. |
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| 11. |
- Dahl-Halvarsson, Martin, et al.
(författare)
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Drosophila model of myosin myopathy rescued by overexpression of a TRIM-protein family member
- 2018
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 115:28
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Tidskriftsartikel (refereegranskat)abstract
- Myosin is a molecular motor indispensable for body movement and heart contractility. Apart from pure cardiomyopathy, mutations in MYH7 encoding slow/beta-cardiac myosin heavy chain also cause skeletal muscle disease with or without cardiac involvement. Mutations within the alpha-helical rod domain of MYH7 are mainly associated with Laing distal myopathy. To investigate the mechanisms underlying the pathology of the recurrent causative MYH7 mutation (K1729del), we have developed a Drosophila melanogaster model of Laing distal myopathy by genomic engineering of the Drosophila Mhc locus. Homozygous MhcK1728del animals die during larval/pupal stages, and both homozygous and heterozygous larvae display reduced muscle function. Flies expressing only MhcK1728del in indirect flight and jump muscles, and heterozygous MhcK1728del animals, were flightless, with reduced movement and decreased lifespan. Sarcomeres of MhcK1728del mutant indirect flight muscles and larval body wall muscles were disrupted with clearly disorganized muscle filaments. Homozygous MhcK1728del larvae also demonstrated structural and functional impairments in heart muscle, which were not observed in heterozygous animals, indicating a dose-dependent effect of the mutated allele. The impaired jump and flight ability and the myopathy of indirect flight and leg muscles associated with MhcK1728del were fully suppressed by expression of Abba/Thin, an E3-ligase that is essential for maintaining sarcomere integrity. This model of Laing distal myopathy in Drosophila recapitulates certain morphological phenotypic features seen in Laing distal myopathy patients with the recurrent K1729del mutation. Our observations that Abba/Thin modulates these phenotypes suggest that manipulation of Abba/Thin activity levels may be beneficial in Laing distal myopathy.
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| 12. |
- Dahl-Halvarsson, Martin, et al.
(författare)
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Impaired muscle morphology in a Drosophila model of myosin storage myopathy was supressed by overexpression of an E3 ubiquitin ligase
- 2020
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Ingår i: Disease Models & Mechanisms. - : The Company of Biologists. - 1754-8403 .- 1754-8411. ; 13:12
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Tidskriftsartikel (refereegranskat)abstract
- Myosin is vital for body movement and heart contractility. Mutations in MYH7, encoding slow/beta-cardiac myosin heavy chain, are an important cause of hypertrophic and dilated cardiomyopathy, as well as skeletal muscle disease. A dominant missense mutation (R1845W) in MYH7 has been reported in several unrelated cases of myosin storage myopathy. We have developed a Drosophila model for a myosin storage myopathy in order to investigate the dose-dependent mechanisms underlying the pathological roles of the R1845W mutation. This study shows that a higher expression level of the mutated allele is concomitant with severe impairment of muscle function and progressively disrupted muscle morphology. The impaired muscle morphology associated with the mutant allele was suppressed by expression of Thin (herein referred to as Abba), an E3 ubiquitin ligase. This Drosophila model recapitulates pathological features seen in myopathy patients with the R1845W mutation and severe ultrastructural abnormalities, including extensive loss of thick filaments with selective A-band loss, and preservation of I-band and Z-disks were observed in indirect flight muscles of flies with exclusive expression of mutant myosin. Furthermore, the impaired muscle morphology associated with the mutant allele was suppressed by expression of Abba. These findings suggest that modification of the ubiquitin proteasome system may be beneficial in myosin storage myopathy by reducing the impact of MYH7 mutation in patients.
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| 13. |
- Dahl-Halvarsson, Martin, et al.
(författare)
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Myosin Storage Myopathy in C. elegans and Human Cultured Muscle Cells
- 2017
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Myosin storage myopathy is a protein aggregate myopathy associated with the characteristic subsarcolemmal accumulation of myosin heavy chain in muscle fibers. Despite similar histological findings, the clinical severity and age of onset are highly variable, ranging from no weakness to severe impairment of ambulation, and usually childhood-onset to onset later in life. Mutations located in the distal end of the tail of slow/beta-cardiac myosin heavy chain are associated with myosin storage myopathy. Four missense mutations (L1793P, R1845W, E1883K and H1901L), two of which have been reported in several unrelated families, are located within or closed to the assembly competence domain. This location is critical for the proper assembly of sarcomeric myosin rod filaments. To assess the mechanisms leading to protein aggregation in myosin storage myopathy and to evaluate the impact of these mutations on myosin assembly and muscle function, we expressed mutated myosin proteins in cultured human muscle cells and in the nematode Caenorhabditis elegans. While L1793P mutant myosin protein efficiently incorporated into the sarcomeric thick filaments, R1845W and H1901L mutants were prone to formation of myosin aggregates without assembly into striated sarcomeric thick filaments in cultured muscle cells. In C. elegans, mutant alleles of the myosin heavy chain gene unc-54 corresponding to R1845W, E1883K and H1901L, were as effective as the wild-type myosin gene in rescuing the null mutant worms, indicating that they retain functionality. Taken together, our results suggest that the basis for the pathogenic effect of the R1845W and H1901L mutations are primarily structural rather than functional. Further analyses are needed to identify the primary trigger for the histological changes seen in muscle biopsies of patients with L1793P and E1883K mutations.
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| 14. |
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| 15. |
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| 16. |
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| 17. |
- Engkvist, Josefin, 1972, et al.
(författare)
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Alumina scale formation on a powder metallurgical FeCrAl alloy (Kanthal APMT) at 900-1100°C in dry O2 and in O2 + H2O
- 2010
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Ingår i: Oxidation of Metals. - : Springer Science and Business Media LLC. - 1573-4889 .- 0030-770X. ; 73:1, s. 233-253
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Tidskriftsartikel (refereegranskat)abstract
- A Rapidly Solidified Powder (RSP) metallurgical FeCrAl alloy, Kanthal APMT, was exposed in dry and humid O-2 for 72 h at 900-1,100 A degrees C. The formed oxide scales were characterized using gravimetry in combination with advanced analysis techniques (SEM, EDX, TEM, XRD, AES and SIMS). The oxide scales were at all exposures composed of two-layered alpha-Al2O3 scales exhibiting a top layer of equiaxed grains and a bottom layer containing elongated grains. A Cr-rich zone, originating in the native oxide present before exposure, separated these two layers. The top alpha-Al2O3 layer is suggested to have formed by transformation of outwardly grown metastable alumina, while the inward-grown bottom alpha-Al2O3 layer had incorporated small Zr-, Hf- and Ti-rich oxide particles present in the alloy matrix. The scale also contained larger Y-rich oxide particles. Furthermore, in the temperature range studied, the presence of water vapour accelerated alloy oxidation somewhat and affected scale morphology.
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| 18. |
- Engkvist, Josefin, 1972, et al.
(författare)
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Oxidation of FeCrAl foils at 500-900 degrees C in dry O-2 and O-2 with 40% H2O
- 2009
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Ingår i: Materials at High Temperatures. - 0960-3409 .- 1878-6413. ; 26:2, s. 199-210
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Tidskriftsartikel (refereegranskat)abstract
- High temperature resistant FeCrAl alloys are frequently used in high temperature applications Such as heating elements and metal based catalytic converter bodies. When exposed to high temperatures an adherent, slowly growing, dense aluminium oxide layer forms on the surface, which protects the underlying alloy from severe degradation. The composition, structure and properties of the formed oxide layer are strongly dependent on the alloy composition, temperature and oxidation environment. In this study, the Sandvik 0C404 FeCrAl alloy, in the form of 50 mu m thick foils, was exposed isothermally in the temperature range 500-900 degrees C for 168 hours in dry O-2 and in O-2 with 40 vol.% H2O. The surface morphology, composition and microstructure of the grown oxide scales were characterized by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), grazing incidence X-ray diffraction (GI-XRD), Auger electron spectroscopy (AES), and time of flight secondary ion mass spectrometry (TOF-SIMS). The oxidation process was faster at 900 degrees C than at 500 and 700 degrees C. At 500 degrees C a thin (10-20 nm) mixed oxide of Fe, Cr and Al was formed. Exposure at 700 degrees C resulted ill a similar (40-50 nm) duplex oxide, in both dry O-2 and in O-2 With 40 vol.% H2O. These oxide scales consisted of all inner and an outer relatively pure alumina separated by a Cr-rich band. This type of duplex oxide scale also formed at 900 degrees C with a thin inward growing alpha-Al2O3 at the oxide/metal interface and an outward growing layer outside a Cr-rich band. However, at 900 degrees C the Outward growing layer showed two types of oxide morphologies; a thin smooth base oxide and a much thicker nodular oxide grown on top of substrate ridges. In dry O-2 atmosphere, the main part of this outward growing layer had transformed to alpha-Al2O3. Only in the outer part of the thick oxide nodules, metastable alumina was found. When exposed in the presence of water vapour the main pall of the metastable alumina remained untransformed.
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| 19. |
- Esmaily, Mohsen, 1987, et al.
(författare)
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Achieving superior corrosion resistance in friction stir processed AA6005-T6 aluminum alloy joints
- 2015
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Ingår i: ECS Transactions. - : The Electrochemical Society. - 1938-5862 .- 1938-6737. ; 64:26, s. 29-43
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Konferensbidrag (refereegranskat)abstract
- In this study, ultra-fine grained (UFG) structure was produced in the stir zone (SZ) of AA6005-T6 alloy joints using friction stir processing (FSP) cooled by liquid nitrogen (N 2 ). Conventional friction stir welding (FSW) was used to fabricate reference joints. The corrosion properties of the cooled joints were investigated by atmospheric corrosion tests. The corrosion exposures were carried out at a relative humidity (RH) of 95%, 400 ppm CO 2 and at 22°C. The rapidly cooled joints exhibited exceptional corrosion resistance in both corrosion experiments as well as better mechanical properties compared to those of the FSWed joints. The better corrosion resistance of the quenched sample was attributed to the microstructural modification of the joint.
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| 20. |
- Esmaily, Mohsen, 1987, et al.
(författare)
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Microstructural characterization of the Mg-Al alloy AM50 produced by a newly developed rheo-casting process
- 2014
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Ingår i: Materials Characterization. - : Elsevier BV. - 1044-5803 .- 1873-4189. ; 95, s. 50-64
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Tidskriftsartikel (refereegranskat)abstract
- The microstructure of rheo-cast Mg-Al alloy AM50 produced by the RheoMetal process is investigated and compared with the same alloy produced by conventional high pressure die casting. The size and arrangement of microstructural constituents and pores are characterized quantitatively using image analyzing techniques. The nearest neighbor distribution of the intermetallic particles is determined. The area fraction of porosity in rheo-cast AM50 is about half that found in the high pressure die cast alloy. In rheo-cast material, the distribution of p phase (Mg17Al12) is relatively uniform throughout the cast. In contrast, the beta phase particles tend to form macroscopic agglomerates in high pressure die cast material. The externally solidified grains in the rheo-cast material exhibit a smaller aluminum gradient than in the high pressure die cast alloy. This indicates that the solidification of the rheo-cast material is closer to equilibrium.
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| 21. |
- Flynn, Mark, et al.
(författare)
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Audiological concept behind Baha BP100
- 2009
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Ingår i: 7th Asia Pacific Symposium on Cochlear Implants and Related Sciences (APSCI 2009), Singapore, 1-4 December.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 22. |
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| 23. |
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| 24. |
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| 25. |
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| 26. |
- Griesser, Michael, et al.
(författare)
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Fine-scale kin recognition in the absence of social familiarity in the Siberian jay, a monogamous bird species
- 2015
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Ingår i: Molecular Ecology. - : Wiley. - 0962-1083 .- 1365-294X. ; 24:22, s. 5726-5738
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Tidskriftsartikel (refereegranskat)abstract
- Kin recognition is a critical element to kin cooperation, and in vertebrates, it is primarily based on associative learning. Recognition of socially unfamiliar kin occurs rarely, and it is reported only in vertebrate species where promiscuity prevents recognition of first-order relatives. However, it is unknown whether the recognition of socially unfamiliar kin can evolve in monogamous species. Here, we investigate whether genetic relatedness modulates aggression among group members in Siberian jays (Perisoreus infaustus). This bird species is genetically and socially monogamous and lives in groups that are formed through the retention of offspring beyond independence, and the immigration of socially unfamiliar nonbreeders. Observations on feeders showed that genetic relatedness modulated aggression of breeders towards immigrants in a graded manner, in that they chased most intensely the immigrant group members that were genetically the least related. However, cross-fostering experiments showed that breeders were equally tolerant towards their own and cross-fostered young swapped as nestlings. Thus, breeders seem to use different mechanisms to recognize socially unfamiliar individuals and own offspring. As Siberian jays show a high degree of nepotism during foraging and predator encounters, inclusive fitness benefits may play a role for the evolution of fine-scale kin recognition. More generally, our results suggest that fine-graded kin recognition can evolve independently of social familiarity, highlighting the evolutionary importance of kin recognition for social species.
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| 27. |
- Halvarsson, Camilla, et al.
(författare)
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Pyruvate dehydrogenase kinase 1 is essential for transplantable mouse bone marrow hematopoietic stem cell and progenitor function
- 2017
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Ingår i: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 12:2
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Tidskriftsartikel (refereegranskat)abstract
- Background Accumulating evidence suggests that hypoxic areas in the bone marrow are crucial for maintenance of hematopoietic stem cells (HSCs) by supporting a quiescent state of cell cycle and regulating the transplantation capacity of long-term (LT)-HSCs. In addition, HSCs seem to express a metabolic profile of energy production away from mitochondrial oxidative phosphorylation in favor of glycolysis. At oxygen deprivation, hypoxia inducible factor 1 alpha (HIF-1 alpha) is known to induce glycolytic enzymes as well as suppressing mitochondrial energy production by inducing pyruvate dehydrogenase kinase 1 (Pdk1) in most cell types. It has not been established whether PDK1 is essential for HSC function and mediates hypoxia-adapting functions in HSCs. While the Pdk gene family contains four members (Pdk1-4), it was recently shown that Pdk2 and Pdk4 have an important role in regulating LT-HSCs. Principle findings Here we demonstrate that PDK1 activity is crucial for transplantable HSC function. Whereas Pdkl, Pdk2, and Pdk3 transcripts were expressed at higher levels in different subtypes of HSCs compared to differentiated cells, we could not detect any major differences in expression between LT-HSCs and more short-term HSCs and multipotent progenitors. When studying HIF-1 alpha-mediated regulation of Pdk activity in vitro, Pdk1 was the most robust target regulated by hypoxia, whereas Pdk2, Pdk3, and Pdk4 were not affected. Contrary, genetic ablation in a cre-inducible Hif-1 alpha knockout mouse did not support a link between HIF-1 alpha and Pdk1. Silencing of Pdk1 by shRNA lentiviral gene transfer partially impaired progenitor colony formation in vitro and had a strong negative effect on both long-term and short-term engraftment in mice. Conclusions Our study demonstrates that PDK1 has broad effects in hematopoiesis and is a critical factor for engraftment of both HSCs and multipotent progenitors upon transplantation to recipient mice. While Pdk1 was a robust hypoxia-inducible gene mediated by HIF-1 alpha in vitro, we could not find evidence of any in vivo links between Pdk1 and HIF-1 alpha.
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| 28. |
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| 29. |
- Hellström, Kristina M, 1971, et al.
(författare)
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Oxidation behaviour of a (Mo, W)Si2-based composite in dry and wet oxygen atmospheres in the temperature range 350–950◦C
- 2009
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Ingår i: Journal of the European Ceramic Society. - : Elsevier BV. - 1873-619X .- 0955-2219. ; 29:10, s. 2105-2118
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Tidskriftsartikel (refereegranskat)abstract
- The oxidation of a (Mo, W)Si2-based composite was investigated in the temperature range (350–950 °C). The influence of temperature and water vapour on the oxidation was examined. The kinetics was studied using a thermobalance whereas the morphology and composition of the oxides were examined using X-ray diffractometer (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive X-ray (EDX). Focused ion beam (FIB) milling was performed on some of the oxide scales which allowed us to look at a non-mechanically disturbed scale/oxide in cross-section. Rapid oxidation was found to occur in the 550–750 °C temperature range. The mass gains were significantly larger in O2 than in O2 + 10%H2O. The different mass changes in the two exposure atmospheres were attributed to the higher vapour pressure of the volatile MoO2(OH)2 and WO2(OH)2 species in O2 + 10%H2O than that of (MoO3)3 and (WO3)3 in dry O2. The peak mass gain was found to occur at a temperature of about 750 °C in O2 and 650 °C in O2 + 10%H2O. At temperatures above 850 °C, especially when water vapour is present, the removal of Mo and W from the oxide scales is rapid enough to allow partial healing of the silica, causing the oxidation rate to drop. At 950 °C in O2 + 10%H2O, a protective SiO2 scale could be re-established quickly and maintained, causing the oxidation to essentially cease.
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| 30. |
- Hellström, Kristina M, 1971, et al.
(författare)
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Oxidation of a Dispersion-Strengthened Powder Metallurgical FeCrAl Alloy in the Presence of O2 at 1,100°C: The Influence of Water Vapour
- 2015
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Ingår i: Oxidation of Metals. - : Springer Science and Business Media LLC. - 1573-4889 .- 0030-770X. ; 83:5-6, s. 533-558
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Tidskriftsartikel (refereegranskat)abstract
- The oxidation behaviour of the FeCrAl alloy Kanthal(A (R)) APMT in O-2 + N-2 and O-2 + N-2 + H2O environments at 1,100 A degrees C was investigated using thermogravimetry and detailed analyses of the scale morphology with SEM/EDX and STEM/EDX. Wrought FeCrAl alloy Kanthal(A (R)) AF was used as a reference. Exposure time was up to 168 h. Water vapour influenced the early oxide growth kinetics. This effect is explained in terms of water acting as an oxidant, simultaneously with O-2. During later stages of the exposures, H2O had no effect on the kinetics of oxidation.
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| 31. |
- Hellström, Kristina M, 1971, et al.
(författare)
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The Oxide Scales Formed on a Dispersion-Strengthened Powder Metallurgical FeCrAl Alloy at 900 A degrees C in O-2 and in O-2 + H2O
- 2015
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Ingår i: Oxidation of Metals. - : Springer Science and Business Media LLC. - 1573-4889 .- 0030-770X. ; 84:1-2, s. 1-19
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Tidskriftsartikel (refereegranskat)abstract
- Early oxide scale growth on an oxide dispersion strengthened rapidly solidified powder FeCrAl material, Kanthal(A (R)) APMT, was investigated at 900 A degrees C in an O-2 + N-2 and an O-2 + H2O + N-2 environment for up to 168 h. Gravimetry was used to follow oxide growth and the oxide scale was examined with XRD. Scale morphology was investigated in detail with SEM/EDX, TEM/EDX/CBED. The alloy rapidly formed a protective two-layered alpha-alumina scale containing oxide nodules. Between the top and bottom alumina layers there was a zone containing chromia-rich particles 5-20 nm in diameter, corresponding to the original sample surface. The alumina scale mainly grew inward after 1 h of oxidation. Alumina scale growth at 900 A degrees C was initially somewhat faster in an O-2 + H2O + N-2 environment than in an O-2 + N-2 environment.
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| 32. |
- Ingemarsson, Linda, 1972, et al.
(författare)
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Oxidation behavior at 300–1000C of a (Mo,W)Si2-based composite containing boride
- 2010
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Ingår i: Intermetallics. - : Elsevier BV. - 0966-9795. ; 18:1, s. 77-86
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Tidskriftsartikel (refereegranskat)abstract
- The oxidation behavior of a (Mo,W)Si2 composite with boride addition was examined at 300–1000C for24 h in dry O2. The oxidation kinetics was studied using a thermobalance, and the oxide scales wereanalyzed using a combination of electron microscopy (SEM/EDX, FIB, BIB) and XRD. Accelerated oxidationwas found to occur between 500C and 675C, with a peak mass gain at 625C. The rapid oxidation isattributed to the vaporization of molybdenum oxide that leaves a porous and poorly protective silicalayer behind. At higher temperature (700–1000C) a protective scale forms, consisting of a dense SiO2/B2O3 glass.
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| 33. |
- Ingemarsson, Linda, 1972, et al.
(författare)
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Oxidation behavior of a Mo (Si, Al)(2)-based composite at 300-1000 degrees C
- 2010
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Ingår i: Intermetallics. - : Elsevier BV. - 0966-9795 .- 1879-0216. ; 18:4, s. 633-640
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Tidskriftsartikel (refereegranskat)abstract
- The oxidation behavior of a Mo (Si,Al)(2)-based composite of Mo(Si,Al)(2), Al2O3 and Mo-5(Si,Al)(3) (Kanthal Super ER) in synthetic air was investigated. The samples were oxidized isothermally for up to 72 h at 300-1000 degrees C using a thermobalance. The microstructure was analyzed by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Auger Electron Spectroscopy (AES) depth profiling. Broad ion beam milling (BIB) was used to prepare cross-sections. Oxidation behavior depended strongly on the composition of the substrate which consisted of a Mo(Si,Al)(2) matrix and the minority phases Mo-5(Si,Al)(3) and Al2O3. At 300-500 degrees C the mass gains were small with parabolic kinetics, oxidation resulting in a mixture of oxides that reflects the substrate composition. At 600 and 700 degrees C the oxide scale is thin and protective and depleted in molybdenum, a mass loss occurring due to MoO3 vaporization. At 1000 degrees C a protective alpha-alumina scale forms.
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| 34. |
- Ingemarsson, Linda, 1972, et al.
(författare)
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Oxidation behavior of a Mo(Si,Al)2 composite at 900–1600 C in dry air
- 2013
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Ingår i: Journal of Materials Science. - : Springer Science and Business Media LLC. - 0022-2461 .- 1573-4803. ; 48:4, s. 1511-1523
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Tidskriftsartikel (refereegranskat)abstract
- The oxidation of a Mo(Si,Al)2-based compositeis investigated in the temperature range 900–1600 C indry air. Exposure time was 72 h. Comparisons are madewith the oxidation behavior of a conventional MoSi2-basedmaterial. Cross-sections are examined with scanning electronmicroscopy and transmission electron microscopy; thephase composition is analyzed by X-ray diffraction andconvergent beam electron diffraction. The material forms acontinuous external a-alumina scale throughout the temperature range. Below the scale, there is a continuousMo5(Si,Al)3 layer that overlies Mo(Si,Al)2 in the bulk. TheMo(Si,Al)2 phase immediately beneath the Mo5(Si,Al)3layer is depleted in Al. No indications of MoO3 volatilization could be found for the Mo(Si,Al)2 material
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| 35. |
- Ingemarsson, Linda, 1972, et al.
(författare)
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Oxidation behaviour of a Mo(Si,Al)2 based composite at 1500 degrees C
- 2011
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Ingår i: Intermetallics. - : Elsevier BV. - 0966-9795. ; 19:9, s. 1319-1329
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Tidskriftsartikel (refereegranskat)abstract
- The oxidation of a Mo(Si,Al)(2) composite is investigated at 1500 degrees C in dry air using exposure times from 1 to 1000 h. Cross sections are examined with Scanning Electron Microscopy (SEM) and the phase composition is analyzed by X-ray diffraction (XRD). The material forms a continuous and protective alumina layer, the growth of the alumina layer following parabolic kinetics. Immediately below the scale Mo(Si,Al)(2) is replaced by a Mo(5)(Si,Al)(3) layer due to the flux of aluminum to the scale. The Al concentration in the Mo(Si,Al)(2) phase in the underlying substrate decreases from 27% before exposure to 16-17% after 1000 h. The continuous alumina layer becomes covered by a top layer consisting of alumina grains embedded in a viscous melt with approximate composition 7 Na(2)O-15 Al(2)O(3)-78 SiO(2). With time, sodium is volatilized from the melt and the top scale layer transforms to a mixture of alumina, mullite and silica melt.
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| 36. |
- Israelsson, Niklas, 1983, et al.
(författare)
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KCl-Induced Corrosion of an FeCrAl Alloy at 600°C in O2 + H2O Environment: The Effect of Pre-oxidation
- 2015
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Ingår i: Oxidation of Metals. - : Springer Science and Business Media LLC. - 1573-4889 .- 0030-770X. ; 83:1-2, s. 29-53
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Tidskriftsartikel (refereegranskat)abstract
- The present study investigates the influence of H2O and KCl on the high temperature corrosion of an FeCrAl alloy at 600 A degrees C. Polished samples were exposed to O-2 or O-2 + H2O and to O-2 + H2O with KCl applied. The samples were investigated using SEM/EDX, XRD, IC, AES and SIMS. It was found that KCl accelerates corrosion and that a rapidly growing iron-rich oxide forms with time. Chromate formation is shown to initiate the formation of a non-protective oxide scale. Pre-oxidising the alloy before exposure in the presence of KCl had a strongly beneficial effect on the corrosion.
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| 37. |
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| 38. |
- Jonsson, T., et al.
(författare)
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An ESEM in situ investigation of the influence of H2O on iron oxidation at 500 degrees C
- 2009
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Ingår i: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 51:9, s. 1914-1924
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Tidskriftsartikel (refereegranskat)abstract
- The initial oxidation of iron and the effect of different O-2/H2O mixtures have been investigated through ESEM in situ exposure and analysis at 500 degrees C. In dry and wet air a two-layered magnetite forms beneath a thin, fine-grained hematite layer. while only a two-layered magnetite forms in H2O. The two-layered magnetite is separated by a straight interface (in all environments), which is suggested to be the original metal surface. The presence of low levels of water vapour (similar to 1% H2O) produces a thicker hematite layer (compared to dry air), exhibiting a large number of whiskers. At least four different factors are suggested to influence the local growth rate: the surface of the metal grain, the thickness of the hematite layer, the oxide grain size and the exposure environment. The ESEM in situ exposures have in addition been shown to have high quality and reproducibility.
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| 39. |
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| 40. |
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| 41. |
- Liu, Fang, 1975, et al.
(författare)
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First Three-Dimensional Atomic Resolution Investigation of Thermally Grown Oxide on a FeCrAl Alloy
- 2015
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Ingår i: Oxidation of Metals. - : Springer Science and Business Media LLC. - 1573-4889 .- 0030-770X. ; 83:5-6, s. 441-451
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Tidskriftsartikel (refereegranskat)abstract
- Thermally grown Al2O3 scales formed on a FeCrAl alloy, Kanthal APMT, were successfully analysed using pulsed green laser atom probe tomography. The alloy was exposed to 5 vol.% O-2 + 95 vol.% N-2 at 900 A degrees C for 1 h, and covered by a thin layer of Al2O3. Cr segregation to some of the Al2O3 grain boundaries was observed. The continuous Cr-rich band, which contains a large number of Cr- and/or Fe- enriched nano-sized particles, was studied in detail. Four types of nanoparticles were found and analysed. Oxidation mechanisms at the initial stages are discussed based on the observations.
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| 42. |
- Lundgren, Solveig M, 1943, et al.
(författare)
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Quality assessment and comparison of grading between examiners and supervisors of Bachelor theses in nursing education.
- 2008
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Ingår i: Nurse education today. - : Elsevier BV. - 0260-6917. ; 28:1, s. 24-32
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Tidskriftsartikel (refereegranskat)abstract
- This study compares supervisors' and examiners' grading of quality of theses at Bachelor level in nursing. An instrument developed to asses the quality of theses was used. Eight aspects of quality were rated. One hundred and fifteen theses were rated by both examiner and supervisor. Significant correlations were found between examiners' and supervisors' ratings of all aspects of quality. Good agreement was found in 89-96% of the ratings on individual aspects of quality. The means of differences between ratings were small but significantly differed from zero in four out of eight aspects. In theses rated low for quality of language and formality, differences between examiners' and supervisors' ratings on all aspects of quality were significantly larger than in theses rated high for quality of language and formality. The general conclusion is that the evaluations made by examiners and by supervisors corresponded well. Differences found indicates that examiners in general give lower scores than supervisors especially on quality aspects that are most closely related to research methods and experiences. This study is part of a larger project that is investigating quality of theses and the student's attitudes and learning experiences of writing theses.
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| 43. |
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| 44. |
- Sadeghi, André M., et al.
(författare)
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Expressivity of hearing loss in cases with Usher syndrome type IIA
- 2013
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Ingår i: International Journal of Audiology. - : Routledge. - 1499-2027 .- 1708-8186. ; 52:12, s. 832-837
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The purpose of this study was to compare the genotype/ phenotype relationship between siblings with identical USH2A pathologic mutations and the consequent audiologic phenotypes, in particular degree of hearing loss (HL). Decade audiograms were also compared among two groups of affected subjects with different mutations of USH2A.Design: DNA samples from patients with Usher syndrome type II were analysed. The audiological features of patients and affected siblings with USH2A mutations were also examined to identify genotype-phenotype correlations.Study sample: Genetic and audiometric examinations were performed in 18 subjects from nine families with Usher syndrome type IIA.Results: Three different USH2A mutations were identified in the affected subjects. Both similarities and differences of the auditory phenotype were seen in families with several affected siblings. A variable degree of hearing loss, ranging from mild to profound, was observed among affected subjects. No significant differences in hearing thresholds were found the group of affected subjects with different pathological mutations.Conclusions: Our results indicate that mutations in the USH2A gene and the resulting phenotype are probably modulated by other variables, such as modifying genes, epigenetics or environmental factors which may be of importance for better understanding the etiology of Usher syndrome.
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| 45. |
- Sand, Tommy, 1982, et al.
(författare)
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Efficacy of an external chromia layer in reducing nitridation of high temperature alloys
- 2022
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Ingår i: Corrosion Science. - : Elsevier BV. - 0010-938X. ; 197
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Tidskriftsartikel (refereegranskat)abstract
- Six high temperature alloys have been exposed in N2/H2 environments at 900 °C. In order to study the efficacy of a chromia barrier layer against nitrogen ingress, experiments were performed in two environments having the same N2/H2 ratio but slightly different water content, chromia formation being spontaneous in one case only. The samples were evaluated by SEM/STEM/EDX, XRD, gravimetry and GD-OES. The presence of an external chromia scale reduced nitridation of the alloy by 50–95%. Furthermore, in the presence of a continuous alumina layer no nitridation of the alloy was detected.
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| 46. |
- Shoja, S., et al.
(författare)
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Enhanced steel machining performance using texture-controlled CVD alpha-alumina coatings : Fundamental degradation mechanisms
- 2024
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Ingår i: International Journal of Machine Tools and Manufacture. - 0890-6955. ; 197
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Tidskriftsartikel (refereegranskat)abstract
- Cemented carbide inserts coated with CVD α-alumina, particularly those exhibiting a (0001) texture, have proven highly effective in steel turning. Despite the established superior performance of (0001) textured alumina coatings, the underlying reasons remain unclear. This study explores the influence of the crystallographic texture of alumina on wear mechanisms in various chip-tool contact zones on the insert rake face. The objective is to establish a fundamental understanding of the active degradation mechanisms and machining performance by relating coating texture to the orientation and deformation of individual Al2O3 grains. Two multilayered coatings, Al2O3 on Ti(C,N), featuring (0001)- and (112‾0)-textured CVD α-alumina, were assessed in dry turning of a bearing steel. The wear rate of the (112‾0) coating was double that of the (0001) coating. Worn coatings exhibit nano-terrace formation at the insert edge, likely due to chemical etching. In the sticking zone, plastic deformation leads to larger facets for grains oriented with the chip flow direction, while rounded surfaces result if this condition is not met. In the transition zone, both (0001) and (112‾0) textured coatings undergo increased plastic deformation accompanied by sub-surface dislocations. (0001) texture deforms more by basal slip creating a wavy coating pattern with steps present at larger misalignments of the lattice planes in neighboring grains while (112‾0) texture deforms by several slip systems creating elongated ridges and ruptured-like areas resulting in rougher surface. This difference in surface morphology is then inherited by the abrasion of submicron coating fragments embedded in the chip (more in (112‾0) texture) in the sliding zone resulting in an even rougher surface. Chemical reaction with the hot chip may also contribute to wear acting as an additional mechanism. This fundamental understanding contributes to the potential enhancement of steel machining using texture-controlled CVD alumina coatings, ultimately improving coated cutting tool performance.
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