| 1. |
- Davidsson, P, et al.
(författare)
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DESIGN AND OPERATION OF A LOW-TEMPERATURE SCANNING TUNNELING MICROSCOPE SUITABLE FOR OPERATION BELOW 1-K
- 1992
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Ingår i: Ultramicroscopy. - 0304-3991 .- 1879-2723. ; 42-44, s. 1470-1475
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Tidskriftsartikel (refereegranskat)abstract
- A scanning tunneling microscope suitable for very low temperatures has been designed, and preliminary testing has been carried out. In order to improve cooling and temperature uniformity the instrument is arranged for operation immersed in the 3He-4He mixture inside the mixing chamber of a small dilution refrigerator. A discussion of the specific problems present in the design of this kind of an instrument is given as well as a description of our design. Special attention is given to the vacuum sealing and vibration-damping solutions required.
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| 2. |
- Hellquist, H. B., et al.
(författare)
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Activated T cells in the nasal mucosa of patients with grass-pollen allergy. A pilot study
- 1992
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Ingår i: Rhinology. - Amsterdam, Netherlands : International Rhinologic Society. - 0300-0729 .- 1996-8604. ; 30:1, s. 57-63
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Tidskriftsartikel (refereegranskat)abstract
- Six patients with grass-pollen allergy were provoked with water-soluble grass pollen until a pronounced allergic reaction occurred. This was performed outside the grass-pollen season, and the allergen was administered on the edge of the inferior turbinate. Biopsies were taken both before provocation and during the reaction, 15-30 minutes after provocation. The nasal population of immunohistochemically positive cells for HLA-DR, CD1, interleukin-2-receptor, IgE, CD4 and CD8 were studied. There was a marked increase of IL2-R-positive cells (activated T lymphocytes) in the nasal mucosa after provocation, whilst the other cell populations approximately remained unchanged (apart from a certain increase of IgE). The increase of activated T lymphocytes may imply that certain subsets of T cells play a role in the allergic response, and that the role of helper T cells very likely is much more complex than the regulation of mast cells and eosinophils. The concomitant presence of Langerhans' cells (CD1-positive) and activated T lymphocytes may indicate a possible association on site between an antigen-presenting cell and both effector as well as memory cells in allergic reactions.
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| 3. |
- Kubatkin, S E, et al.
(författare)
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Defect switching in a mesoscopic sample induced by a scanning tunnelling microscope
- 1994
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Ingår i: Journal of Physics. - : IOP Publishing. - 0953-8984 .- 1361-648X. ; 6, s. L473-L478
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Tidskriftsartikel (refereegranskat)abstract
- A new method is introduced to study electron transport on the mesoscopic scale. A scanning tunnelling microscope (STM) tip is used both to form a point-contact potential probe to a thin film and to affect scattering centres in its vicinity. We detect abrupt changes in the voltage with this probe as a function of both tip position and tip-sample voltage. These changes could be interpreted as due to spatial shifts of scattering centres in the film surface.
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| 4. |
- Kubatkin, S E, et al.
(författare)
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Movement of scattering centers in a point contact induced by a scanning tunneling microscope
- 1994
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Ingår i: Physica. B, Condensed matter. - : Elsevier BV. - 0921-4526 .- 1873-2135. ; 194-196:Part 1, s. 991-992
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Tidskriftsartikel (refereegranskat)abstract
- A new method is introduced to study transport in a mesoscopic sample. The electric field from an STM-tip is used to locally influence a mesoscopic object. We detect abrupt changes in the mesoscopic signal both as a function of the tip position and tip-sample voltage. They could be interpreted as due to spatial shifts or changes in the activity of scattering centers in the sample.
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