RESUMEN
We describe the synthesis and characterization of the homologous p-iodophenylsilsesquioxanes (SQs) [p-I-C(6)H(4)SiO(1.5)](n) (n = 8, 10, 12) via ICl-promoted iodination (-40 to -60 degrees C) with overall yields of 80-90% and > 95% para selectivity following recrystallization. Characterization by NMR, FTIR, TGA, and single-crystal X-ray diffraction are reported and compared to data previously published for I(8)OPS. Coincidentally, we report a new synthesis of the elusive pentagonal decaphenyl SQ (dPS) [C(6)H(4)SiO(1.5)](10) and its characterization by NMR and single-crystal X-ray studies. These unique macromolecules possess equivalent chemical functionality but varying symmetries (cubic, pentagonal, and D(2d) dodecahedral), offering the potential to develop homologous series of functionalized star and dendrimer compounds with quite different core geometries and thereby providing the potential to greatly vary structure-property relationships in derivative compounds and nanocomposites made therefrom. We find that all three compounds decompose on heating to approximately 400 degrees C/N(2) with loss of I(2) to form robust, microporous materials with BET surface areas of 500-700 m(2)/g, pore volumes of 0.25-0.31 cm(3)/g, average pore widths of 8 A, and oxidative stabilities > or = 500 degrees C and with solid-phase morphologies varying from crystalline to mostly amorphous, as indicated by powder XRD and SEM studies. These latter findings point to important symmetry effects relating directly to packing in the crystalline phase prior to thermolysis.
RESUMEN
The study objective is to evaluate the results of our surgical technique for children with congenital adrenal hyperplasia and ambiguous genitalia at the University Hospital of Heidelberg, Department of Paediatric Surgery. The records of 19 patients with congenital adrenal hyperplasia treated between 1972 and 2004 were reviewed with respect to age at surgery, operative procedures and outcome. We describe the recession clitoroplasty technique currently used in our hospital and highlight the importance of short and long-term follow-up results with respect to appearance, position and size of the clitoris and quality of the vagina. One-stage recession clitoroplasty and vaginoplasty gives very satisfactory cosmetic and functional results, with few complications and a reduced need for secondary surgical interventions. The results of this study support the assumption that total correction can be achieved through a single-stage operation, performed in infancy.