Biomedical subjects

P Böttcher

Publications and source records attributed to P Böttcher.

4 recordsLinked to original sources

PubMed2001

Halogenodisilanes: precursors for new disilane derivatives.

Starting from hexachloro- or hexabromodisilane a wide variety of 1,2-disubstituted tetrachlorodisilanes (RSiCl2SiCl2R) [R = Cp (2a), 4-iPrC6H4(SiMe3)N (2b), 2,6-iPr2C6H3(SiMe3)N (2c), (Me3Si)2CH (2d) (Me3Si)3C (2e), (Me3Si)3Si (2f)], tetrabromodisilanes (RSiBr2SiBr2R) [R = Cp (3a), 4-iPrC6H4(SiMe3)N (3b), (Me3Si)3Si (3f)] and the monosubstituted pentahalogenodisilanes CpSiX2SiX3 [X = Cl (4), Br (5)] were prepared. The tetrachlorodisilanes 2a-e are converted to various functionalized disilanes. Ammonolysis of 2a-e leads to the tetraaminodisilanes [RSi(NH2)2Si(NH2)2R] 6a-e. A reduction of 2d with LiAlH4 resulted in the formation of the disilane RSiH2SiH2R [R = (Me3Si)2CH] 7 and the metathesis with Me3SnF yielded the tetrafluorodisilane RSiF2SiF2R [R = (Me3Si)2CH] 8. Treatment of 6d with reagents containing H acidic protons (HX) [X = Br, I and OH] leads under elimination of NH3 to the tetrabromo- R2SiBr2SiBr2R (3d) tetraiodo- RSiI2SiI2R (9) and the tetrahydroxodisilane RSi(OH)2Si(OH)2R (10) [R = (Me3Si)2CH]. Single-crystal X-ray structural analysis of 2d, 6a, 6d, and 9 are reported.

Journal Article↗

PubMed2000

Gd(8)Se(15)-A 24-Fold Superstructure of the ZrSSi Type Financial support by the Deutsche Forschungsgemeinschaft and the Fonds der Chemischen Industrie is gratefully acknowledged; one of us (E.D.) is additionally indebted to the Deutscher Akademischer Austauschdienst for her grant.

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Journal Article↗

PubMed1999

Macroscopic cryosectioning: a simple new method for producing digital, three-dimensional databases in veterinary anatomy.

Using a new method derived from the 'visible human project' (Spitzer et al., 1996, Journal of the American Medical Informatics Association, 3, 118-130), we were able to establish a simple and low-cost tool which produces high-quality cryosections of macroscopic specimens down to 1-mm slice thickness, based on a milling process. For the first time, a macroscopic cryotome is available to veterinary anatomists, which can be used on cutting faces up to 25 cm high and 50 cm wide and with a minimal slice thickness of 1 mm without any gap. The method employs a modified wood circular saw. Recording of the cutting faces is carried out 'online' by a high-resolution digital camera. The process has been tested extensively and produces high-quality sections of very hard material (teeth) as well as of very soft tissues (brain). It is now possible in veterinary medicine to provide three-dimensional anatomical databases of high resolution and of tissue-specific colour as an additional tool for high-quality two- and three-dimensional anatomical reconstructions for use in science and education.

Anatomy↗

PubMedDate not supplied

The visible animal project: a three-dimensional, digital database for high quality three-dimensional reconstructions.

The "Visible Animal Project" (VAP) is comprised of axial anatomic cryosections and corresponding CT and MR images of a mature dog. The digital database is used for the creation of three-dimensional computer graphics of canine anatomy. The technique of cryodissection is described in detail. The combining of the corresponding CT and MR images, and cryosections as well as the data processing for the creation of three-dimensional reconstructions is presented and examples are shown. For the first time a complete high-resolution three-dimensional database of a dog is available, which can be used as the base for further high quality three-dimensional reconstructions, similar to the "Visible Human Project" (VHP).

Anatomy, Cross-Sectional↗