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Selected AbstractsCytological features of lipoblastoma: A report of three casesDIAGNOSTIC CYTOPATHOLOGY, Issue 3 2005Ph.D., V. Veronika Kloboves-Prevodnik M.D. Abstract Lipoblastoma is a rare benign neoplasm occurring mostly in children under the age of three. Accurate preoperative diagnosis is mandatory for planning the treatment. The main aim of this study is to establish the cytological features of lipoblastoma and to answer the question: "Is cytological diagnosis of lipoblastoma reliable?" Preoperative fine-needle aspiration biopsy (FNAB) and tissue sections of three children treated for lipoblastoma at the Division of Pediatrics, University Medical Center, Ljubljana, Slovenia, in the period from 1997 to 2004 were reexamined. The Giemsa- and Papanicolaou-stained FNAB smears were moderately or poorly cellular and contained lipocytes, lipoblasts, and spindle cells in various proportions. The tumor cells were in clusters and tissue fragments or as single cells. Thin branching capillaries were observed in most of the clusters and tissue fragments. In the background, abundant myxoid extracellular material and naked oval nuclei were present. In the first case, the cytological diagnosis was benign soft-tissue tumor, in the second the diagnosis was not conclusive and the last case was correctly diagnosed as lipoblastoma. In the differential diagnosis of the second case, both lipoblastoma and liposarcoma were considered cytologically as well as histologically. At 7-yr follow-up, there is no evidence of the disease. Thus, we conclude that lipoblastoma with typical cytological features could be accurately diagnosed by FNAB. However, tumors containing numerous lipoblasts could pose a diagnostic problem. Diagn. Cytopathol. 2005;33:195,200. © 2005 Wiley-Liss, Inc. [source] Synthesis and Characterisation of a New Cu(O2CNAllyl2)2 Carbamato Complex and an Unusual Polymeric CuI Complex [CuI4Cl4(NHAllyl2)4]n: New Insights into Metal Carbamato ChemistryEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 35 2009Alberto Albinati Abstract Transition-metal N,N -dialkylcarbamato complexes represent an interesting class of compounds that can be conveniently used as precursors for the controlled formation of inorganic compounds, typically oxides. They can also be used as convenient precursors for chemical grafting of metal oxides on oxide surfaces as well as for the synthesis of inorganic,organic hybrid materials. In this last case, the presence of double bonds on the complex would enable its covalent embedding into a polymer matrix through reaction with suitable monomers. To this aim, we addressed the synthesis of an allyl-functionalised copper carbamato complex. During the synthesis of the N,N -diallylcarbamato complex Cu(O2CNAllyl2)2 (Cu1), the formation of the crystalline and unusual polymeric CuI complex [CuI4Cl4(NHAllyl2)4]n (Cu2) was observed. The new compound was characterised by X-ray single crystal diffraction and FTIR, 1H and 13C NMR spectroscopic analysis. In an attempt to investigate the redox mechanism and the equilibria leading to the formation of the observed unusual CuI polymeric complex, gas chromatography coupled with mass spectrometry (GC,MS) experiments were carried out, which allowed us to identify 3,4-dimethylpyrrole as the oxidation product of the reaction, leading to the reduction of CuII to CuI.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] An extended Huygens' principle for modelling scattering from general discontinuities within hollow waveguidesINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 5 2001Ronald L. Ferrari Abstract The modal fields, generalized scattering matrix (GSM) theory and dyadic Green's functions relating to a general uniform hollow waveguide are briefly reviewed in a mutually consistent normalization. By means of an analysis linking these three concepts, an extended version of the mathematical expression of Huygens' principle is derived, applying to scattering from an arbitrary object within a hollow waveguide. The integral-equation result expresses the total field in terms of the incident waveguide modal fields, the dyadic Green's functions and the tangential electromagnetic field on the surface of the object. It is shown how the extended principle may be applied in turn to perfect conductor, uniform material and inhomogeneous material objects using a quasi method of moments (MM) approach, coupled in the last case with the finite element method. The work reported, which indicates how the GSM of the object may be recovered, is entirely theoretical but displays a close similarity with established MM procedures. Copyright © 2001 John Wiley & Sons, Ltd. [source] Allylation of Aldehydes Promoted by the Cerium(III) Chloride Heptahydrate/Sodium Iodide System: the Dependence of Regio- and Stereocontrol on the Reaction ConditionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-13 2005G. Bartoli Abstract The cerium(III) chloride heptahydrate/sodium iodide complex (CeCl3,,,7,H2O/NaI) acts as a useful promoter in the carbon-carbon bond forming reaction by addition of allyltributylstannanes to aldehydes. The reaction of 2-butenyltributylstannane shows that the regio- and the stereochemical outcomes depend on the reaction conditions. When the promoter is adsorbed on a solid support (aluminum oxide), a highly prevalent formation of the ,-adduct is observed in solvent-free conditions. Conversely, when the reaction is carried out in acetonitrile as the solvent, the ,-adduct largely prevails. In the last case, a complete stereocontrol is observed, the less stable (Z)-isomer being obtained in high geometrical purity. [source] Thoracic epidural catheters via the caudal and lumbar approaches using styletted multiple port catheters in pediatric patients: a report of three casesACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2006B. C. H. Tsui Advancing catheters from the lumbar and caudal epidural spaces to the thoracic level has been reported to be an alternative to the direct thoracic approach. However, as children grow, the threading of catheters in the epidural space becomes increasingly difficult. This report describes three cases of thoracic epidural placement using a multiport catheter threaded from the caudal and lumbar spaces using electrical stimulation guidance. In the first case, a multiport catheter was threaded 22 cm from the lumbar space to T8 following a failed attempt with a single-port catheter in a 9-year-old boy scheduled to undergo a right nephrectomy. In the second case, a multiport catheter was threaded 26 cm from the caudal space to T9 in a 3-year-old girl undergoing fundoplication. In the last case, a multiport catheter was inserted at the completion of a fundoplication in a 2-year-old girl after it had been confirmed that the single-port catheter inserted prior to surgery had not advanced to the desired thoracic level. The multiport catheter was threaded 17 cm without resistance from the caudal space to T9. In all cases, electrical stimulation was used to confirm the location of the catheter tip at the time of insertion. The position of the catheters was later confirmed by X-ray. The multiport catheter incorporates a stylet, which extends to a closed distal tip, within a catheter body that ejects fluid from three lateral holes in a direction perpendicular to the advancing catheter. These properties may facilitate the reliable advancement of catheters in the epidural space. [source] Exact methods based on node-routing formulations for undirected arc-routing problemsNETWORKS: AN INTERNATIONAL JOURNAL, Issue 1 2006R. Baldacci Abstract This article proposes a new transformation of undirected arc-routing problems into equivalent node-routing problems, with emphasis on the transformation of Capacitated Arc Routing Problems (CARP) into Capacitated Vehicle Routing Problems (CVRP). For this last case, an analogue transformation has already been proposed in Pearn et al., where each required CARP edge is mapped onto a triplet of CVRP nodes. In our case, only two CVRP nodes are needed for every CARP required edge. The transformed instances have a structure and a dimension that make most CARP benchmarks solvable by state of the art CVRP techniques. We thus propose a general purpose transformation of arc into node-routing problems and new results on lower bounds and exact methods for CARP instances. © 2005 Wiley Periodicals, Inc. NETWORKS, Vol. 47(1), 52,60 2006 [source] An optical device to measure in-line residence time distribution curves during extrusionPOLYMER ENGINEERING & SCIENCE, Issue 1 2002Tomás Jeferson A. Mélo This paper proposes a setup for in-line measurement of residence time distribution (RTD) curves during extrusion. The detection system is composed of a slit die with transparent borosilicate glass windows fixed at the extruder exit, an optical arrangement with an incandescent light microbulb with fixed luminescence, and a Light Dependent Resistor (LDR) photocell of CdS. As the tracer passes through the light path, the reduction in the transmitted light intensity is followed by changes in the voltage induced by the photocell to an electric circuit. The signal is collected by an external interface and sent to a computer. Software acquires the data, does all calculations, and presents all curves and calculated variables to the monitor. The validation of the system was done by checking for data reproducibility and linearity with tracer concentration. The response of the LDR sensor with respect to the concentration of the tracer was calibrated using a set of slight dark film, obtaining a logarithmic relationship. Thus the signal enhances any disturbance, if present, particularly in the tail-region of the curves. Measurements were taken from a Werner-Pfleiderer ZSK 30 twin-screw extruder equipped with K-Tron gravimetric feeders operating with various screw speeds, feeding rates and screw configurations. In this last case, the presence of kneading elements was taken into account. [source] Towards a classification of icosahedral viruses in terms of indexed polyhedraACTA CRYSTALLOGRAPHICA SECTION A, Issue 5 2006A. Janner The standard Caspar & Klug classification of icosahedral viruses by means of triangulation numbers and the more recent novel characterization of Twarock leading to a Penrose-like tessellation of the capsid of viruses not obeying the Caspar,Klug rules can be obtained as a special case in a new approach to the morphology of icosahedral viruses. Considered are polyhedra with icosahedral symmetry and rational indices. The law of rational indices, fundamental for crystals, implies vertices at points of a lattice (here icosahedral). In the present approach, in addition to the rotations of the icosahedral group 235, crystallographic scalings play an important rôle. Crystallographic means that the scalings leave the icosahedral lattice invariant or transform it to a sublattice (or to a superlattice). The combination of the rotations with these scalings (linear, planar and radial) permits edge, face and vertex decoration of the polyhedra. In the last case, satellite polyhedra are attached to the vertices of a central polyhedron, the whole being generated by the icosahedral group from a finite set of points with integer indices. Three viruses with a polyhedral enclosing form given by an icosahedron, a dodecahedron and a triacontahedron, respectively, are presented as illustration. Their cores share the same polyhedron as the capsid, both being in a crystallographic scaling relation. [source] Inner Ear Extension of Vestibular Schwannomas,THE LARYNGOSCOPE, Issue 9 2003Maurizio Falcioni MD Abstract Objective Inner ear extension of vestibular schwannomas (VSs) is a rare finding but has important clinical implications. This report reviews the treatment options and presents the experience of the Gruppo Otologico, Piacenza, Italy, in this field. Study Design Case report and literature review. Methods Five cases of VSs with inner ear extension were surgically removed. In all of them, the cochlea was partially or completely invaded by the lesion. Results In 4 cases, the inner ear extension was preoperatively identified on magnetic resonance imaging, and the surgical removal was planned through a transotic approach. In the last case, the cochlear invasion was not detected preoperatively, and the lesion was removed during a second surgery performed to seal a cerebrospinal fluid fistula. Conclusions VSs with inner ear extension should be distinguished from pure intralabyrinthine schwannomas because of differences in clinical significance. Cochlear involvement is more frequent than vestibular involvement and is often accompanied by a dead ear. Dead ear caused by small VSs should alert the surgeon to the possibility of a cochlear extension. The presence of an intracochlear involvement requires the adoption of an approach that allows control of the cochlear turns, and we found the transotic approach to be the most suitable. Undetected cochlear extensions that are left in place may grow with time. [source] Enantiospecific Syntheses of Copper Cubanes, Double-Stranded Copper/Palladium Helicates, and a (Dilithium),Dinickel Coronate from Enantiomerically Pure Bis-1,3-diketones,Solid-State Self-Organization Towards Wirelike Copper/Palladium Strands,CHEMISTRY - A EUROPEAN JOURNAL, Issue 5 2008Abstract Enantiomerically pure, vicinal diols 1 afforded in a two-step synthesis (etherification and subsequent Claisen condensation) chiral bis-1,3-diketones H2L(S,S) (3,a,c) with different substitution patterns. Reaction of these C2 -symmetric ligands with various transition-metal acetates in the presence of alkali ions generated distinct polynuclear aggregates 4,8 by diastereoselective self-assembly. Starting from copper(II) acetate monohydrate and depending on the ratio of transition-metal ion to alkali ion to ligand, chiral tetranuclear copper(II) cubanes (C,C,C,C)-[Cu4(L(S,S))2(OMe)4] (4,a,c) or dinuclear copper(II) helicates (P)-[Cu2(L(S,S))2] (5) could be synthesized with square-pyramidal and square-planar coordination geometry at the metal center. In analogy to the last case, with palladium(II) acetate double-stranded helical systems (P)-[Pd2(L(S,S))2] (6,7) were accessible exhibiting a linear self-organization of ligand-isolated palladium filaments in the solid state with short inter- and intramolecular metal distances. Finally, the introduction of hexacoordinate nickel(II) in combination with lithium hydroxide monohydrate and chiral ligand H2L(S,S) (3,a) allowed the isolation of enantiomerically pure dinuclear nickel(II) coronate [(Li,MeOH)2,{(,,,)-Ni2(L(S,S))2(OMe)2}] (8) with two lithium ions in the voids, defined by the oxygen donors in the ligand backbone. The high diastereoselectivity, induced by the chiral ligands, during the self-assembly process in the systems 4,8 could be exemplarily proven by circular dichroism spectroscopy for the synthesized enantiomers of the chiral copper(II) cubane 4,a and palladium(II) helicate 6. [source] | |||||||||||||