while the complementary strand 3 was unchanged (Scheme 1).

The novel monovinyl-functional silsesquioxane cage 1-(9-decenyl)-3,5,7,9,11,13,15-heptaethylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxane has been prepared and copolymerized with ethene and propene. The monovinyl-functional spherosiloxane was obtained from the octahydridosilsesquioxane (HSiO3/ 2)8 via hydrosilation with dibrominated decadiene, followed by reaction of the nonreacted SiH groups with ethene, debromination, and chromatographic separation. Homopolymerization and copolymerization with ethene and propene was performed using different methylalumoxane-activated metallocene catalysts. Depending on catalyst structure comonomer incorporation between 17 and 25 wt % was achieved. High molar mass copolymers were obtained containing pendant octasiloxane cubes. Characterization by 13C, 1H, and 29Si NMR spectroscopy confirmed that the catalyst did not modify the Si−O−Si framework. Incorporation up to 25 wt % (1.2 mol %) of the spherosiloxane-based monomer accounted for a decrease of the melting temperature by 18 K with respect to polyethene. As demonstrated by means of thermal gravimetric analysis, thermostability under air was improved in the polyethene copolymer in comparison to polyethene.

EUS-TNB allows reliable tissue sampling for the diagnosis of pancreatic masses, but its use is limited to lesions in the body and tail of the pancreas. EUS-FNAB using a 22-gauge needle may be useful for accurate diagnosis in some patients with masses in the uncinate process or the head of the pancreas.

The homologous series of 8-fold alkyl-substituted octasilsesquioxane has been prepared by hydrosilation of alkenes with octakis(hydridosilsesquioxane) (HSiO3/2)8. Ethene, propene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene were employed either in bulk or in toluene solution. The homologous series of 1,3,5,7,9,11,13,15-octaalkylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxanes, which are interesting model compounds for silsesquioxane-based materials was characterized by 1H, 13C, and 29Si NMR spectroscopy, IR and mass spectroscopy, and elemental analysis. Melting points of the compounds were studied by DSC, revealing a strong decrease of the melting point from the octapropyl-substituted T8 to the octapentyl derivative. Melting points for derivatives with longer n-alkyl chains showed an odd−even effect. TGA evidenced thermal stability under nitrogen up to temperatures between 200 and 400 °C and under air up to temperatures between 200 and 250 °C.