| 1. |
- Canovic, Sead, 1979, et al.
(author)
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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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In: Journal of the Electrochemical Society. - : The Electrochemical Society. - 1945-7111 .- 0013-4651. ; 157:6, s. C223-C230
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Journal article (peer-reviewed)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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| 2. |
- Liu, Fang, 1975, et al.
(author)
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Cyclic oxidation of two FeCrAlRE foils at 1100 oC - The influence of the concentration of minor alloying elements on scale microstructure
- 2008
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In: Materials Science Forum. - 1662-9752 .- 0255-5476. ; 595-598, s. 707-716
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Conference paper (peer-reviewed)abstract
- Two FeCrAlRE alloys, a commercial, 0C404, and a model alloy in the form of thin foils,with different Mn, Nb, Mo and Ti concentrations were subjected to cyclic oxidation in lab air at1100°C. The oxidized samples were studied by gravimetry, Grazing-Incidence X-ray Diffraction(GI-XRD), Scanning Transmission Electron Microscopy (STEM), and Energy Dispersive X-ray(EDX) analysis. The two FeCrAl alloys exhibit different oxidation kinetics; however, both alloyshave the same weight gain after 500 hours exposure. During the early stages the scale consistsmainly of α-Al2O3 together with some oxide particles containing Mn, Al, Fe and Cr formed on thealloys. After 500 hours the 0C404 scale locally also consists of larger polycrystalline regions ofMn-Cr-Al spinel. In addition, Si-rich oxide, chromia and Al-Cr oxide could be observed at themetal/oxide interface.
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| 3. |
- Benson, Mikael, 1954, et al.
(author)
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DNA microarray analysis of chromosomal susceptibility regions to identify candidate genes for allergic disease: A pilot study
- 2004
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In: Acta Oto-Laryngologica. - : Informa UK Limited. - 1651-2251 .- 0001-6489. ; 124:7, s. 813-819
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Journal article (peer-reviewed)abstract
- Objective-To examine whether DNA microarray analysis of chromosomal susceptibility regions for allergy can help to identify candidate genes. Material and Methods-Nasal biopsies were obtained from 23 patients with allergic rhinitis and 12 healthy controls. RNA was extracted from the biopsies and pooled into three patient and three control pools. These were then analysed in duplicate with DNA microarrays containing 12626 genes. Candidate genes were further examined in nasal biopsies (real-time polymerase chain reaction) and blood samples (single nucleotide polymorphisms) from other patients with allergic rhinitis and from controls. Results-A total of 37 differentially expressed genes were identified according to criteria involving both the size and consistency of the gene expression levels. The chromosomal location of these genes was compared with the chromosomal susceptibility regions for allergic disease. Using a statistical method, five genes were identified in these regions, including serine protease inhibitor, Kazal type, 5 (SPINK5) and HLA-DRB2. The relevance of these genes was examined in other patients with allergic rhinitis and in controls; none of the genes were differentially expressed in nasal biopsies. Moreover, no association between allergic rhinitis and SPINK5 polymorphisms was found, at either the genotype or haplotype level. Conclusions-DNA microarray analysis of chromosomal susceptibility regions did not lead to identification of candidate genes that could be validated in a new material. However, because gene polymorphisms may cause differential gene expression, further studies, including validation data, are needed to examine this approach.
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| 4. |
- Bergin, Philip, 1975, et al.
(author)
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Gastric gelatinase B/matrix metalloproteinase-9 is rapidly increased in Helicobacter felis-induced gastritis.
- 2008
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In: FEMS immunology and medical microbiology. - 0928-8244. ; 52:1, s. 88-98
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Journal article (peer-reviewed)abstract
- It has previously been shown that matrix metalloproteinase-9 (MMP-9) levels, originating from macrophages, are considerably increased in human Helicobacter pylori-associated gastritis. Here, the early kinetics of the MMP-9 response resulting from Helicobacter infection in C57BL/6 and MMP-9 knock-out mice using the murine Helicobacter felis model were examined. H. felis infection induced severe gastritis in the murine stomach at just 2 weeks after infection. Before gastritis, an increase was observed in MMP-9-positive cells detected by immunohistochemistry in the basal lamina propria. This finding was corroborated by gelatin zymography of stomach samples. As the gastritis increased so did the concentration of MMP-9 and the incidence of gastric MMP-9-positive cells, their location corresponding to that of macrophages. In contrast, systemic levels of MMP-9 remained unchanged. When MMP-9-deficient mice were infected with H. felis, no significant difference in gastritis development was detected compared with disease development in wild-type animals. We conclude that MMP-9 production is an early event in the response to gastric Helicobacter infection, a feature that may favor the recruitment of immune cells early during infection. At later stages, however, the increased levels of MMP-9 may damage the integrity of the stomach mucosa.
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| 5. |
- Blank, Malou, 1975, et al.
(author)
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Mobility patterns in inland southwestern Sweden during the Neolithic and Early Bronze Age
- 2021
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In: Archaeological and Anthropological Sciences. - : Springer Science and Business Media LLC. - 1866-9557 .- 1866-9565. ; 13
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Journal article (peer-reviewed)abstract
- In this paper, we investigate population dynamics in the Scandinavian Neolithic and Early Bronze Age in southwestern Sweden. Human mobility patterns in Falbygden were studied by applying strontium isotope analysis combined with archaeological and bioarchaeological data, including mtDNA and sex assessment on a large dataset encompassing 141 individuals from 21 megalithic graves. In combination with other archaeological and anthropological records, we investigated the temporal and spatial scale of individual movement, mobility patterns of specific categories of people and possible social drivers behind them. Our results of strontium and biomolecular analyses suggest that mobility increased in the Late Neolithic and Early Bronze Age compared to the earlier parts of the Neolithic. The data indicate individuals moving both into and away from Falbygden. Mobility patterns and contact networks also shift over time.
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| 6. |
- Coutinho, Alexandra, et al.
(author)
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The Neolithic Pitted Ware culture foragers were culturally but not genetically influenced by the Battle Axe culture herders
- 2020
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In: American Journal of Physical Anthropology. - : Wiley. - 0002-9483 .- 1096-8644. ; 172:4, s. 638-649
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Journal article (peer-reviewed)abstract
- ObjectivesIn order to understand contacts between cultural spheres in the third millennium BC, we investigated the impact of a new herder culture, the Battle Axe culture, arriving to Scandinavia on the people of the sub‐Neolithic hunter‐gatherer Pitted Ware culture. By investigating the genetic make‐up of Pitted Ware culture people from two types of burials (typical Pitted Ware culture burials and Battle Axe culture‐influenced burials), we could determine the impact of migration and the impact of cultural influences.MethodsWe sequenced and analyzed the genomes of 25 individuals from typical Pitted Ware culture burials and from Pitted Ware culture burials with Battle Axe culture influences in order to determine if the different burial types were associated with different gene‐pools.ResultsThe genomic data show that all individuals belonged to one genetic population—a population associated with the Pitted Ware culture—irrespective of the burial style.ConclusionWe conclude that the Pitted Ware culture communities were not impacted by gene‐flow, that is, via migration or exchange of mates. These different cultural expressions in the Pitted Ware culture burials are instead a consequence of cultural exchange.
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| 7. |
- Dambrauskas, Zilvinas, et al.
(author)
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Expression of major histocompatibility complex class I-related chain A/B (MICA/B) in pancreatic carcinoma.
- 2014
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In: International Journal of Oncology. - : Spandidos Publications. - 1019-6439 .- 1791-2423. ; 44:1, s. 99-104
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Journal article (peer-reviewed)abstract
- Major histocompatibility complex classI-related chain A and B (MICA/B) are two stress-inducible ligands that bind to the immunoreceptor NKG2D and play an important role in mediating cytotoxicity of NK and Tcells. Release of MIC molecules from the cell surface is thought to constitute an immune escape mechanism of tumor cells and thus could be associated with more aggressive course of tumor growth. In this study, we investigated the expression of MICA/B in ductal pancreatic carcinoma and serum in relation to tumor stage, differentiation and survival. MICA/B expression in tumor tissues and sera from patients with pancreatic cancer were analyzed by immunohistochemical staining (IHC), western blotting and ELISA, respectively. MICA/B expression was present in 17 of 22 (77%) of the tumors but not in normal pancreatic ductal epithelial cells. Poorly differentiated tumors showed more pronounced MICA/B expression compared to differentiated tumors, but did not correlate significantly to other tumor characteristics. MICA/B-negative tumors displayed significantly lower incidence of lymph node metastases (p<0.01), and less mortality within 3 years following resection (p<0.02). In conclusion, tissue levels of MICA/B expression were elevated in pancreatic cancer cells without elevated levels in serum, despite well-recognized acute phase reactants in serum. Poorly differentiated tumors showed high MICA/B expression, which was related to extended tumor lymph node metastases and less frequent long-term survival.
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| 8. |
- Engkvist, Josefin, 1972, et al.
(author)
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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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In: Materials at High Temperatures. - 0960-3409 .- 1878-6413. ; 26:2, s. 199-210
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Journal article (peer-reviewed)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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| 9. |
- Günther, Torsten, et al.
(author)
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Population genomics of Mesolithic Scandinavia : Investigating early postglacial migration routes and high-latitude adaptation
- 2018
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In: PLoS biology. - : Public Library of Science (PLoS). - 1544-9173 .- 1545-7885. ; 16:1
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Journal article (peer-reviewed)abstract
- Scandinavia was one of the last geographic areas in Europe to become habitable for humans after the Last Glacial Maximum (LGM). However, the routes and genetic composition of these postglacial migrants remain unclear. We sequenced the genomes, up to 57x coverage, of seven hunter-gatherers excavated across Scandinavia and dated from 9,500-6,000 years before present (BP). Surprisingly, among the Scandinavian Mesolithic individuals, the genetic data display an east-west genetic gradient that opposes the pattern seen in other parts of Mesolithic Europe. Our results suggest two different early postglacial migrations into Scandinavia: initially from the south, and later, from the northeast. The latter followed the ice-free Norwegian north Atlantic coast, along which novel and advanced pressure-blade stone-tool techniques may have spread. These two groups met and mixed in Scandinavia, creating a genetically diverse population, which shows patterns of genetic adaptation to high latitude environments. These potential adaptations include high frequencies of low pigmentation variants and a gene region associated with physical performance, which shows strong continuity into modern-day northern Europeans.
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| 10. |
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