Nuttall-Pommerenke theorems for homogeneous Padé approximants

We investigate Nuttall-Pommerenke theorems for several variable homogeneous Padé approximants using ideas of Goncar, Karlsson and Wallin.     

A non-MRA C^r Frame Wavelet with Rapid Decay

A generalized filter construction is used to build an example of a non-MRA normalized tight frame wavelet for dilation by 2 in . This example has the same multiplicity function as the Journé wavelet, yet has a Fourier transform and can be made to be for any fixed postive integer . L. Baggett and P. Jorgensen were supported by a US–NSF Focused Research Group (FRG) grant.     

Differential proteome analysis of colon carcinoma cell line SW480 after reconstitution of the tumour suppressor Smad4

The tumour suppressor gene Smad4 is frequently inactivated in gastrointestinal carcinomas. Smad4 plays a pivotal role in transducing signals of the transforming growth factor-β (TGF-β) superfamily of proteins. Inactivation of Smad4 seems to occur late during tumour progression when tumours acquire invasive and metastatic properties. Identification of proteins directly or indirectly regulated by Smad4 would, therefore, ease the future design of new diagnostic and therapeutic strategies for gastrointestinal carcinoma. We have used human colon carcinoma cell line SW480 stably transfected with Smad4 as an in-vitro model system to identify Smad4-regulated proteins by applying two-dimensional gel electrophoresis (2DE) then MALDI-PMF/PFF-MS. We identified a total of 47 protein species with a Smad4-dependent expression. From the functions of the candidate proteins we obtained new insights into Smad4’s participation in processes, for example apoptosis, differentiation, and proliferation.     

Photo-induced site-specific nitridation of plasma-deposited B10C2Hx films: A new pathway toward post-deposition doping of semiconducting boron carbides

We show that dopant impurities can be introduced in a controlled, site-specific manner into pre-deposited semiconducting boron carbide films. B―N bond formation has been characterized by X-ray photoelectron spectroscopy for semiconducting B₁₀C₂H_x films exposed to vacuum ultraviolet photons in the presence of NH₃. Core level photoemission data indicate that B―NH₂ bonds are formed at B sites bonded to other boron atoms (B―B), and not at boron atoms adjacent to carbon atoms (B―C) or at carbon atom sites. Nitridation obeys diffusion-limited kinetics. These results indicate that dopant species can be introduced in a controlled, site-specific manner into pre-deposited boron carbide films, as opposed to currently required dopant incorporation during the deposition process.     

Complex Inorganic/Organic Core-Shell Particles by an Inverse Emulsion Technique

Two synthetic approaches to modify the surface of inorganic particles are presented. In the first approach the inorganic particles are prepared in-situ in a confined space in inverse emulsions. The used amphiphilic statistical copolymers act not only as emulsifiers, but they also hydrophobize the remaining inorganic particles after the precipitation. This approach represents a versatile method to obtain various inorganic nanoparticles as well as more complex inorganic materials like core-multiple shell and perovskite-based nanoparticles. The second procedure uses preformed inorganic particles, as an aqueous dispersion, to modify them with surface active amphiphilic copolymers in a multicomponent solvent system. This method turns out to be a simple but highly efficient method to modify preformed inorganic nanoparticles. The particles are characterized by SEM, TEM and dynamic light scattering. The modified inorganic nanoparticles are suitable to be homogenously incorporated into a polymer matrix to form transparent nanocomposite materials.     

A unification of two refinements of Euler’s partition theorem

We obtain a unification of two refinements of Euler’s partition theorem respectively due to Bessenrodt and Glaisher. A specialization of Bessenrodt’s insertion algorithm for a generalization of the Andrews-Olsson partition identity is used in our combinatorial construction.     

Dirhodium(II) Carboxylate Catalyzed Formation of 1,2,3‐Trisubstituted Indoles from Styryl Azides

Dirhodium(II)‐carboxylate complexes were discovered to promote the selective migration of acyl groups in trisubstituted styryl azides to form 1,2,3‐trisubstituted indoles. The styryl azides are readily available in three steps from cyclobutanone and 2‐iodoaniline.     

Iron(II) bromide-catalyzed synthesis of benzimidazoles from aryl azides

The identity of the ortho-substituent of an aryl azide influences its reactivity toward transition metals. Substitution of a vinyl group with an imine disables rhodium(II)-mediated C-H amination and triggers a Lewis acid mechanism catalyzed by iron(II) bromide to facilitate benzimidazole formation.