Rendering of multiresolution models with texture

State of the art multiresolution modeling allows to selectively refine a coarse mesh of an object on the visually important parts. In this way it is possible to render the geometry of a given object accurately with a minimum number of triangles. The criteria used in current approaches take care of geometric error and even of shading errors. If however texture mapping is used it is inevitable to control displacements and distortions of the texture during refinements.     

Growth factor-induced c-fos expression defines distinct subsets of midbrain dopaminergic neurons

Growth factors are considered pivotal for the development, maintenance, and function of mesencephalic dopaminergic neurons. Recent studies have identified a plethora of growth factors which support the survival and differentiation of embryonic dopaminergic neurons. However, the exact cellular targets of these growth factors, and, thus, their precise mechanisms of action, remain largely unknown. To identify these cellular targets, we analysed, at the single cell level, growth factor-induced c-fos expression in dissociated mesencephalic cell cultures derived from a fos-lac Z transgenic mouse line. Pharmacological interference with cell-cell communication was utilized to control for direct growth factor effects. beta-Galactosidase-expressing cells were phenotypically characterized by immunocytochemistry to specific neural cell markers. Glia cell line-derived neurotrophic factor, basic fibroblast growth factor, brain-derived neurotrophic factor, and neurotrophin-3 directly induced Fos expression in differently sized, yet overlapping, populations of tyrosine hydroxylase-immunoreactive dopaminergic neurons. In an additional subpopulation of dopaminergic neurons, neurotrophin-3 induced fos-lac Z expression indirectly through a glutamate-mediated activation of N-methyl-D-aspartate receptors. Consistent with their proposed glial-mediated mode of action, transforming growth factor alpha and platelet-derived growth factor induced Fos expression predominantly in glia but only in a very small number of dopaminergic neurons. These findings demonstrate that individual dopaminergic neurons represent the direct targets of different sets of extracellular growth factors. Our findings further establish that growth factors affect dopaminergic neurons by indirect mechanisms which require specific cell-cell communication. These data also suggest a potential role for growth factors in the establishment of the morphological and functional diversity of midbrain dopaminergic neurons.     

Galectin 1—A Key Player between Tissue Repair and Fibrosis

Galectins are ten family members of carbohydrate-binding proteins with a high affinity for β galactose-containing oligosaccharides. Galectin-1 (Gal-1) is the first protein discovered in the family, expressed in many sites under normal and pathological conditions. In the first part of the review article, we described recent advances in the Gal-1 modulatory role on wound healing, by focusing on the different phases triggered by Gal-1, such as inflammation, proliferation, tissue repair and re-epithelialization. On the contrary, Gal-1 persistent over-expression enhances angiogenesis and extracellular matrix (ECM) production via PI3K/Akt pathway activation and leads to keloid tissue. Therefore, the targeted Gal-1 modulation should be considered a method of choice to treat wound healing and avoid keloid formation. In the second part of the review article, we discuss studies clarifying the role of Gal-1 in the pathogenesis of proliferative diabetic retinopathy, liver, renal, pancreatic and pulmonary fibrosis. This evidence suggests that Gal-1 may become a biomarker for the diagnosis and prognosis of tissue fibrosis and a promising molecular target for the development of new and original therapeutic tools to treat fibrosis in different chronic diseases.     

Hierarchically structured polymer blends based on silsesquioxane hybrid nanocomposites with quaternary ammonium units for antimicrobial coatings

The paper reports the first study on hierarchical assemblies (nanofibrillar micelles confined within semi-cylindrical shells) with silsesquioxane and quaternary ammonium units obtained through polymer blending intended for antimicrobial/antifungal stone coatings. The formation of hierarchical structures on solid surfaces is due to the multiple intermolecular ionic interactions, intermolecular Van der Waals and hydrophobic interactions acting among the component molecules. Their antimicrobial/antifungal properties toward the Gram-negative bacteria, Escherichia coli, Gram-positive bacteria, Staphylococcus aureus, and Candida albicans fungus were determined in aqueous solution and were found to be strongly dependent of the topographical features of the coating.     

Approximation of nonlinear systems with radial basis functionneural networks

A technique for approximating a continuous function of n variables with a radial basis function (RBF) neural network is presented. The method uses an n-dimensional raised-cosine type of RBF that is smooth, yet has compact support. The RBF network coefficients are low-order polynomial functions of the input. A simple computational procedure is presented which significantly reduces the network training and evaluation time. Storage space is also reduced by allowing for a nonuniform grid of points about which the RBFs are centered. The network output is shown to be continuous and have a continuous first derivative. When the network is used to approximate a nonlinear dynamic system, the resulting system is bounded-input bounded-output stable. For the special case of a linear system, the RBF network representation is exact on the domain over which it is defined, and it is optimal in terms of the number of distinct storage parameters required. Several examples are presented which illustrate the effectiveness of this technique.     

Immunsuppressiva-Antigen-Konjugate. VIII. Darstellung von 6-Mercaptopurin-Protein-Konjugaten nach dem Azid-Verfahren

Immunosuppressant-Antigen Conjugates. VIII. Preparation of 6-Thiopurine-Protein Conjugates by the Azide Method 6-Carboxymethyl-thiopurine was coupled with human serum albumin (HSA) and bovine serum globuline in the presence of a water soluble carbodiimide. Under these conditions, reaction of HSA with the carbodiimide led to electrophoretically detectable changes. Therefore, further conjugates were prepared by the azide method. The used azides, N-(6-benzylthiopurin- and 6-methylthiopurin-9-yl)-acetyl azide, were obtained from the hydrazides. The prepared conjugates contained upto 4.2% thiopurine, determined by spectrophotometry. It was not possible to obtain an azide from purinyl-(6)-thioacethydrazide.     

Electrochemical study on new polymer composite for zinc corrosion protection

Galvanostatic electrodeposition mode was employed for the synthesis of new polyaniline and polypyrrole-based composite coatings (PANI/PPY) onto pure zinc electrode. Potentiodynamic polarization, open circuit potential measurements and Electrochemical Impedance Spectroscopy (EIS) were employed to assess the ability of these composite coatings to provide an effective barrier to corrosion in chloride environment. Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM) observations were employed to characterize the structure and morphology of the modified electrodes. The coatings deposited galvanostatically at lower current density showed the best quality in terms of protection ability towards aggressive medium. It was found that the new PANI/PPY composite coatings had significantly better properties than single polymer coatings regarding the corrosion protection.