| 1. |
- Skelton, A., et al.
(författare)
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Changes in groundwater chemistry before two consecutive earthquakes in Iceland
- 2014
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Ingår i: Nature Geoscience. - : Springer Science and Business Media LLC. - 1752-0894 .- 1752-0908. ; 7:10, s. 752-756
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Tidskriftsartikel (refereegranskat)abstract
- Groundwater chemistry has been observed to change before earthquakes and is proposed as a precursor signal. Such changes include variations in radon count rates(1,2), concentrations of dissolved elements(3-5) and stable isotope ratios(4,5). Changes in seismicwave velocities(6), water levels in boreholes(7), micro-seismicity(8) and shear wave splitting(9) are also thought to precede earthquakes. Precursor activity has been attributed to expansion of rock volume(7,10,11). However, most studies of precursory phenomena lack sufficient data to rule out other explanations unrelated to earthquakes(12). For example, reproducibility of a precursor signal has seldom been shown and few precursors have been evaluated statistically. Here we analyse the stable isotope ratios and dissolved element concentrations of groundwater taken from a borehole in northern Iceland between 2008 and 2013. We find that the chemistry of the groundwater changed four to six months before two greater than magnitude 5 earthquakes that occurred in October 2012 and April 2013. Statistical analyses indicate that the changes in groundwater chemistry were associated with the earthquakes. We suggest that the changes were caused by crustal dilation associated with stress build-up before each earthquake, which caused different groundwater components to mix. Although the changes we detect are specific for the site in Iceland, we infer that similar processes may be active elsewhere, and that groundwater chemistry is a promising target for future studies on the predictability of earthquakes.
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| 2. |
- Meinecke, AK, et al.
(författare)
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Aberrant mural cell recruitment to lymphatic vessels and impaired lymphatic drainage in a murine model of pulmonary fibrosis
- 2012
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 119:24, s. 5931-5942
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Tidskriftsartikel (refereegranskat)abstract
- Pulmonary fibrosis is a progressive disease with unknown etiology that is characterized by extensive remodeling of the lung parenchyma, ultimately resulting in respiratory failure. Lymphatic vessels have been implicated with the development of pulmonary fibrosis, but the role of the lymphatic vasculature in the pathogenesis of pulmonary fibrosis remains enigmatic. Here we show in a murine model of pulmonary fibrosis that lymphatic vessels exhibit ectopic mural coverage and that this occurs early during the disease. The abnormal lymphatic vascular patterning in fibrotic lungs was driven by expression of platelet-derived growth factor B (PDGF-B) in lymphatic endothelial cells and signaling through platelet-derived growth factor receptor (PDGFR)–β in associated mural cells. Because of impaired lymphatic drainage, aberrant mural cell coverage fostered the accumulation of fibrogenic molecules and the attraction of fibroblasts to the perilymphatic space. Pharmacologic inhibition of the PDGF-B/PDGFR-β signaling axis disrupted the association of mural cells and lymphatic vessels, improved lymphatic drainage of the lung, and prevented the attraction of fibroblasts to the perilymphatic space. Our results implicate aberrant mural cell recruitment to lymphatic vessels in the pathogenesis of pulmonary fibrosis and that the drainage capacity of pulmonary lymphatics is a critical mediator of fibroproliferative changes.
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| 3. |
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| 4. |
- Stockmann-Juvala, H., et al.
(författare)
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Use of read-Across in the health risk assessment of ferrochromium alloys under reach
- 2010
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Ingår i: Proceedings of the 12th International Ferroalloys Congress. - 9789529273409 ; , s. 35-42
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Konferensbidrag (refereegranskat)abstract
- In REACH regulation there is a category of substances called special preparations, to which alloys belong. In the assessment of special preparations not only the bulk composition of an alloy, but also the way the constituent metals are bonded in the chemical matrix, shall be taken into account. The surface of the alloy may limit the ability of constituent metals to be released from the matrix and thus affect the toxicological profile of an alloy. Therefore, the surface characteristics and the release rates of metals shall be taken into account. Finnish Institute of Occupational Health has been carrying out REACH-compliant chemical safety assessment of ferrochromium in collaboration with International Chromium Development Association. Ferrochromium is composed mainly of chromium and iron with small amounts of other metals, e.g. nickel. Since almost no studies have been published on the health effects of ferrochromium, the assessment of ferrochromium should be based on its constituent metals. An approach used in this study included the use of data on surface composition and release of metal constituents from ferrochromium. The chromium oxide surface layer limits the release of nickel and other constituents from ferrochromium and affects the toxicological profile. As a result it can be concluded that ferrochromium alloys can be likened to chromium metal and stainless steel when assessing their health hazards. Thus, the risk assessment can be based largely on existing human, animal and in vitro toxicity data on chromium metal, chromium(III)oxide and stainless steel. By referring to this data, it was possible to make conclusions on health hazards of ferrochromium without need to carry out any new toxicity tests.
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