| 1. |
- Aguer, P, et al.
(author)
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Skin morphology and layer identification using different STIM geometries
- 2005
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In: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 231:1-4, s. 292-299
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Journal article (peer-reviewed)abstract
- The use of on-axis geometry in scanning transmission ion microscopy (STIM) has been widely used for thin biological sample structure identification. In this configuration, the lateral resolution is optimised so that micron or submicron beam spots are easily achieved even for classic microbeam lines. Off-axis STIM was more particularly employed for rapid imaging, and also (when associated to a scattering set-up) for normalising elemental contents obtained by other ion beam analysis techniques in organic thin samples. Due to the very small beam current required, on-axis STIM is a stand-alone technique. Off-axis STIM can be advantageous as it enables the simultaneous utilisation of PIXE and RBS techniques. In this paper, the STIM images obtained with an on-axis geometry, a standard off-axis geometry and a recently developed on-off geometry are presented and discussed. Data from skin samples are used for comparison purposes aiming at studying skin permeability to sunscreens. Skin is a stratified tissue and the precise identification of skin layers is needed to ascertain the penetration depth of the physical filter from the formulation. In addition to the intrinsic difference in image quality due to the beam resolution, the influence of the detector type, implanted silicon detector versus Si pin diode, is discussed on the basis of their energy resolution.. their resistance to beam damage as well as the effect
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| 2. |
- Buckley, Patrick G., et al.
(author)
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Identification of genetic aberrations on chromosome 22 outside the NF2 locus in schwannomatosis and neurofibromatosis type 2
- 2005
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In: Human Mutation. - : Hindawi Limited. - 1059-7794 .- 1098-1004. ; 26:6, s. 540-9
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Journal article (peer-reviewed)abstract
- Schwannomatosis is characterized by multiple peripheral and cranial nerve schwannomas that occur in the absence of bilateral 8th cranial nerve schwannomas. The latter is the main diagnostic criterion of neurofibromatosis type 2 (NF2), which is a related but distinct disorder. The genetic factors underlying the differences between schwannomatosis and NF2 are poorly understood, although available evidence implicates chromosome 22 as the primary location of the gene(s) of interest. To investigate this, we comprehensively profiled the DNA copy number in samples from sporadic and familial schwannomatosis, NF2, and a large cohort of normal controls. Using a tiling-path chromosome 22 genomic array, we identified two candidate regions of copy number variation, which were further characterized by a PCR-based array with higher resolution. The latter approach allows the detection of minute alterations in total genomic DNA, with as little as 1.5 kb per measurement point of nonredundant sequence on the array. In DNA derived from peripheral blood from a schwannomatosis patient and a sporadic schwannoma sample, we detected rearrangements of the immunoglobulin lambda (IGL) locus, which is unlikely to be due to a B-cell specific somatic recombination of IGL. Analysis of normal controls indicated that these IGL rearrangements were restricted to schwannomatosis/schwannoma samples. In the second candidate region spanning GSTT1 and CABIN1 genes, we observed a frequent copy number polymorphism at the GSTT1 locus. We further describe missense mutations in the CABIN1 gene that are specific to samples from schwannomatosis and NF2 and make this gene a plausible candidate for contributing to the pathogenesis of these disorders.
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