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Useful Materials (useful + material)
Selected AbstractsAlar Reconstruction with Subcutaneous Pedicled Nasolabial Flap: Difficulties, Considerations, and Conclusions for This ProcedureDERMATOLOGIC SURGERY, Issue 10 2005Fumiya Iwao MD Background. The subcutaneous pedicled nasolabial flap is a useful material for alar reconstruction. Objective. This article describes the difficulties and considerations in this procedure and discusses the procedural problems involved, drawing conclusions from them. Methods. Case 1: a folded flap was used with a conchal cartilage strut sandwich. Case 2: only a folded flap was used. Case 3: the flap was used to cover the outer surface of the ala, and a mucoperiosteal graft from the hard palate was used for the ala lining. Results. The cartilage strut was not sufficient to support the shape of the ala in case 1. Harvesting a sufficiently wide flap is thought to be important. However, a folded flap had some drawbacks, with the formation of a thick alar rim. Conclusions. The combination of a flap for the outer surface and a mucoperiosteal graft as a lining is thought to be an excellent option for alar reconstruction. [source] Thermoelectric properties of RE2,xMxCuO4 oxide sintering bulksELECTRONICS & COMMUNICATIONS IN JAPAN, Issue 12 2008Yusuke Ichino Abstract La2,xSrxCuO4 (LSCO) and Sm2,xCexCuO4 (SCCO) polycrystal bulks with x=0 to 0.10 were made by solid-phase reaction method. From the X-ray diffraction patterns, LSCO and SCCO were confirmed single phase. Seebeck coefficient, resistivity, and heat conductivity decreased with increasing amount of Sr2+ and Ce2+ substitution. We estimated ZT from these values and found that the highest value of ZT=0.034 at 323 K was achieved in the LSCO with x=0.02. As a result, we conclude that LSCO and SCCO showed high thermoelectric properties around room temperature. We can expect RE2,xMxCuO4 will be a very useful material for thermoelectric module operating at room temperature. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 91(12): 24,28, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10003 [source] A New Method to Prepare Multicellular Spheroids in Cancer Cell Lines Using a Thermo-Reversible Gelation PolymerARTIFICIAL ORGANS, Issue 7 2003Satoshi Tsukikawa Abstract: The purpose of this study is to utilize the thermo-reversible gelation polymer in which the sol-gel transitting phase is reversibly changed by temperature in a three-dimensional culture system. Human cancer cells have been observed to form multicellular spheroids, whereas fibroblasts slowly develop into small spheroids with the culture medium including this polymer. This polymer has some advantages for use as a culture material, as follows: first, cancer cells grow three-dimensionally in the aqueous solution of this polymer; second, it is easy to harvest cells or spheroids in the aqueous solution of this polymer by simply cooling down the temperature; and third, the culture medium including this polymer is so translucent that the cells or spheroids can be observed through a phase-contrast microscope. We thus conclude that this polymer is a very useful material for three-dimensional cultures. [source] Development of Pharmaceutical Drugs, Drug Intermediates and Ingredients by Using Direct Organo-Click ReactionsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 6 2008Dhevalapally B. Ramachary Abstract Here we report on our studies of the use of combinations of amino acids, amines, K2CO3 or Cs2CO3 and CuSO4/Cu for catalysing green cascade reactions. We aimed to prepare the highly reactive and substituted olefin species 7 and 8, under very mild and environmentally friendly conditions, thus giving the hydrogenated products 10 and 12 through the action of Hantzsch ester (4) by self-catalysis through decreasing the HOMO,LUMO energy gaps between olefins 7/8 and Hantzsch ester (4) through biomimetic reductions. Highly useful compounds 10 to 14 were assembled from simple substrates such as aldehydes 1, ketones 2, CH acids 3, Hantzsch ester (4) and alkyl halides 5 by diversity-oriented green synthesis involving cascade olefination/hydrogenation (O/H), olefination/hydrogenation/alkylation (O/H/A) and hydrogenation/olefination/hydrogenation (H/O/H) reaction sequences in one-pot fashion with stereospecific organo- and organo-/metal-carbonate catalysis. Highly functionalized diverse compounds such as 10 to 14 are biologically active products and have found wide applications as pharmaceutical drugs, drug intermediates and drug ingredients. For the first time in organocatalysis, we report the O/H/A/TE reaction to furnish high yields of transesterification products 11 by simply mixing the reactants under proline/K2CO3 catalysis conditions. Additionally, a novel organocatalytic H/O/H reaction sequence for the synthesis of alkyl-substituted aromatics has been developed. Furthermore, for the first time we have developed organocatalysed cascade olefination/hydrogenation/hydrolysis (O/H/H) reactions to furnish highly useful materials such as 2-oxochroman-3-carboxylic acid (14kc) and 2-amino-4H -chromene-3-carbonitrile (14kj) in good yields. Experimentally simple and environmentally friendly organocatalytic two-carbon homologation through cascade O/H/H reactions of aldehydes 1, Meldrum's acid (3c), Hantzsch ester (4) and acetic acid/triethylamine in ethanol has been demonstrated. Additionally, we have developed a green synthesis of the highly substituted 1,2,3-triazole 17 from simple substrates through a two-step combination of olefination/hydrogenation/alkylation and Huisgen cycloaddition reaction sequences under stereospecific organocopper catalysis conditions. In this paper we have found strong support for our hypothesis that, "decreasing the HOMO,LUMO energy gap between olefins 7/8 and Hantzsch ester (4) will drive the biomimetic hydrogenation reaction by self-catalysis". This self-catalysis was further confirmed with many varieties of examples.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Advances and Applications of Biodegradable Elastomers in Regenerative MedicineADVANCED FUNCTIONAL MATERIALS, Issue 2 2010Maria Concepcion Serrano Abstract When elastomers were first proposed as useful materials for regenerative medicine a few decades ago, their high versatility and suitability for a diverse and wide range of in vivo applications could not have been predicted. Due to their ability to recover after deformation, these materials were first introduced in tissue engineering in an attempt to mimic the mechanical properties of the extracellular matrix. Furthermore, elastomeric characteristics have been described as important criteria for cell interaction by modulating cellular behavior. From soft to hard tissues, elastomers have demonstrated degradation, mechanical, and biocompatibility requirements in accordance with the target tissue. In this feature article, biodegradable synthetic polyester elastomers that have been reported in the literature are discussed, with special focus on those that show promise for in vivo tissue replacement. Their satisfactory performance in vivo shows the promise of elastomers for use in regenerative medicine. However, further investigation is required to demonstrate the prospect of elastomer-based therapies in clinical trials. [source] Silicon nanoparticles with chemically tailored surfacesAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 3 2010Andrew S. Heintz Abstract Silicon nanoparticles are useful materials for optoelectronic devices, solar cells and biological markers. The synthesis of air-stable nanoparticles with tunable optoelectronic properties is highly desirable. The mechanochemical synthesis of silicon nanoparticles via high-energy ball milling produces a variety of covalently bonded surfaces depending on the nature of the organic liquid used in the milling process. The use of the C8 reactants including octanoic acid, 1-octanol, 1-octaldehyde and 1-octene results in passivated surfaces characterized by strong SiC bonds or strong SiO bonds. The surfaces of the nanoparticles were characterized by infrared spectroscopy and nuclear magnetic resonance spectroscopy. The nanoparticles were soluble in common organic solvents and remarkably stable against agglomeration and air oxidation. The luminescence and optical properties of the nanoparticles were very sensitive to the nature of their passivating surface. Copyright © 2009 John Wiley & Sons, Ltd. [source] Recent Advances in Immobilized Metal Catalysts for Environmentally Benign Oxidation of AlcoholsCHEMISTRY - AN ASIAN JOURNAL, Issue 2 2008Tsutomu Matsumoto Abstract One of the most significant organic transformations in catalyst technology is the selective oxidation of alcohols. The acceleration of catalyst discovery in this field contributes to the economic and environmental impact in the production of useful materials. Heterogeneous catalysts combined with environmentally benign oxidants, such as molecular oxygen and hydrogen peroxide, are major challenges of exploratory research in the oxidation of alcohols. A wide range of recoverable catalysts has now emerged for these oxidation reactions. In this Focus Review, we present an overview of recent developments in immobilized metal catalysts and evaluate the potential of transition metals in the heterogeneously catalyzed oxidation of alcohols. [source] | |||||||||||||