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| 2. |
- Thulin, M, et al.
(författare)
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Family relationships of the enigmatic rosid genera Barbeya and Dirachma from the Horn of Africa region
- 1998
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Ingår i: PLANT SYSTEMATICS AND EVOLUTION. - : SPRINGER-VERLAG WIEN. - 0378-2697. ; 213:1-2, s. 103-119
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Barbeya is a monotypic genus in the Horn of Africa and adjacent parts of Arabia. It is usually treated as the family Barbeyaceae and regarded as an aberrant member of Urticales. Dirachma, with one species on Socotra and one in Somalia, is usually treated
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| 3. |
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| 4. |
- Dixon, P., et al.
(författare)
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Nitrogen-Hydrogen Defects in GaP
- 1998
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Ingår i: Physica status solidi. B, Basic research. - 0370-1972 .- 1521-3951. ; 210:2, s. 321-326
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Tidskriftsartikel (refereegranskat)abstract
- Models of the nitrogen-hydrogen defect in GaP, which contain one and two H atoms, are investigated using ab initio density functional cluster theory. We find that a single H atom binding to N possesses two infrared absorption frequencies close to those attributed to an NH2 defect. The modes shift with its charge state consistent with the photo-sensitivity found for the defect. A third mode observed for this centre is assumed to be an overtone of the bend mode. The isotope shifts of the calculated modes are in excellent agreement with experiment in contrast with the model which contains two H atoms.
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| 5. |
- Fruttiger, M, et al.
(författare)
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Defective oligodendrocyte development and severe hypomyelination in PDGF-A knockout mice.
- 1999
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Ingår i: Development. - 0950-1991. ; 126:3, s. 457-67
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Tidskriftsartikel (refereegranskat)abstract
- There is a class of oligodendrocyte progenitors, called O-2A progenitors, that is characterized by expression of platelet-derived growth factor alpha-receptors (PDGFRalpha). It is not known whether all oligodendrocytes are derived from these PDGFRalpha-progenitors or whether a subset(s) of oligodendrocytes develops from a different, PDGFR alpha-negative lineage(s). We investigated the relationship between PDGF and oligodendrogenesis by examining mice that lack either PDGF-A or PDGF-B. PDGF-A null mice had many fewer PDGFR alpha-progenitors than either wild-type or PDGF-B null mice, demonstrating that proliferation of these cells relies heavily (though not exclusively) on PDGF-AA homodimers. PDGF-A-deficient mice also had reduced numbers of oligodendrocytes and a dysmyelinating phenotype (tremor). Not all parts of the central nervous system (CNS) were equally affected in the knockout. For example, there were profound reductions in the numbers of PDGFR alpha-progenitors and oligodendrocytes in the spinal cord and cerebellum, but less severe reductions of both cell types in the medulla. This correlation suggests a close link between PDGFRalpha-progenitors and oligodendrogenesis in most or all parts of the CNS. We also provide evidence that myelin proteolipid protein (PLP/DM-20)-positive cells in the late embryonic brainstem are non-dividing cells, presumably immature oligodendrocytes, and not proliferating precursors.
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| 6. |
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| 7. |
- Richardson, J, et al.
(författare)
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Thoracic paravertebral block
- 1998
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Ingår i: British journal of anaesthesia. - : Elsevier BV. - 0007-0912. ; 81:2, s. 230-238
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Tidskriftsartikel (refereegranskat)
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| 8. |
- Richardson, J, et al.
(författare)
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Thoracic paravertebral block - Reply
- 1999
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Ingår i: BRITISH JOURNAL OF ANAESTHESIA. - 0007-0912. ; 82:1, s. 150-150
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 9. |
- von, Rottkay K, et al.
(författare)
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Influence of stoichiometry on electrochromic cerium-titanium oxide compounds
- 1998
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Ingår i: SOLID STATE IONICS. - : ELSEVIER SCIENCE BV. - 0167-2738. ; 115, s. 425-430
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- CeO2-TiO2 finds use as passive counter-electrode in electrochromic devices. Thin films were produced by de-sputtering in a wide range of compositions. Influence of total pressure and oxygen partial pressure on the optical constants of TiO2 was investigate
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