bluuebunny/crossref_metadata_2025_split huggingface dataset:
Correlation of a resistance‐associated Rdl mutation in the German cockroach, Blattella germanica (L), with persistent dieldrin resistance in two Danish field populations
Authors: Hansen Kenneth Klingenberg , Kristensen Michael , Jensen Karl‐Martin Vagn 
Published: April 2005

AbstractDanish Blattella germanica (L) populations carry the resistance‐associated mutation A302S within the Resistance to dieldrin (Rdl) gene. The mutation has remained in field populations long after the discontinuation of dieldrin for cockroach control. The mutation has also persisted in our laboratory strains with high and intermediate frequencies for more than 8 years without selection. The toxicity of dieldrin was tested by topical application to male cockroaches in the susceptible strain DPIL‐SUS and two field strains, Zo960302 and Su960304, which were 1270‐ and 15‐fold resistant to dieldrin at LD50. We report the sequencing of exon 7 of the B germanica Rdl gene and the finding of the putative resistance‐associated A302S mutation. We have developed and implemented a PCR‐based diagnostic method with the detection of a restriction endonuclease polymorphism, which allows for easy discrimination of susceptible, resistant and heterozygote genotypes. The frequency of the resistance‐associate allele A302S was 0.97 and 0.38 in the Zo960302 and Su960304 populations, respectively. The cockroach Rdl A302S allele confers high dieldrin resistance in homozygotes and intermediate resistance in heterozygotes, and its presence is responsible for the persisting dieldrin resistance in Danish populations of B germanica. Copyright © 2005 Society of Chemical Industry
Hall conductivity as a topological invariant
Authors: Kunold A. , Torres M. 
Published: April 2005

AbstractThe object of the present work is to study the quantum Hall effect through its symmetries and topological aspects. We consider the model of an electron moving in a two‐dimensional lattice in the presence of applied in‐plain electric field and perpendicular magnetic field. We refer to this as the two dimensional electric–magnetic Bloch problem (EMB). The Hall conductivity quantization beyond the linear response approximation is analyzed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spin and charge polarization in quantum dot arrays
Authors: Rojas F. , Cota E. , Mireles F. , Ulloa S. E. 
Published: April 2005

AbstractThe role of spin and charge distribution in a planar semiconductor quantum dot array (square geometry) with two electrons is studied in the presence of a driver cell and magnetic nanoparticles located near two quantum dots providing a local magnetic field. We use an extended Hubbard model to describe the electrons in the cell, taking into account intra and intercell Coulomb interaction, intracell tunneling, Rashba spin‐orbit interaction while hopping, as well as the local magnetic interaction with the magnetic nanoparticles. We find that under physically suitable conditions, controlled by the driver, spin and charge cell polarization (spin‐switching effect) can be attained, which is fully tunable by an electrical mechanism. This effect can be useful for spintronics and/or quantum computation applications. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Selective Polymer‐Assisted Product Sequestration for the Generation of Combinatorial Libraries of 1,3‐Thiazines
Authors: Strohmeier Gernot A. , Reidlinger Claudia , Kappe C. Oliver 
Published: April 2005

AbstractCombinatorial approaches for the solution‐phase synthesis of diverse 1,3‐thiazine‐5‐carboxylate libraries are described. Knoevenagel condensation of β‐ketoesters and aldehydes utilizing a polymer‐supported catalyst furnished the anticipated enones, which were subsequently reacted with thioureas to generate 1,3‐thiazine heterocycles among various by‐products. In the key step, the 1,3‐thiazines were selectively sequestered by a polymer‐bound sulfonic acid. Subsequent base‐induced release from the polymer (catch and release) produced 24 1,3‐thiazine products in yields up to 79%, good to excellent purities and in high diversity. In contrast to the polymer‐bound acid‐mediated reaction, this method tolerates more complex building blocks. Furthermore, polymer‐assisted methods for N2‐derivatization were performed, including reactions with activated carboxylic acids, sulfonyl chlorides and isocyanates.
Photodissociation tandem mass spectrometry at 266 nm of an aliphatic peptide derivatized with phenyl isothiocyanate and 4‐sulfophenyl isothiocyanate
Authors: Oh Joo Yeon , Moon Jeong Hee , Lee Yong Ho , Hyung Seok‐Won , Lee Sang‐Won , Kim Myung Soo 
Published: April 2005

AbstractPhotodissociation (PD) tandem mass spectra have been obtained at 266 nm for the protonated molecules of a tryptic peptide, ASHLGLAR, and of its phenyl isothiocyanate and 4‐sulfophenyl isothiocyanate derivatives, generated by matrix‐assisted laser desorption/ionization. Derivatization with the aromatic chromophores greatly reduced the intensity of the laser required for efficient PD. Major fragment ions observed in the three spectra are quite similar. General features of the PD tandem mass spectra and their potential utility for analytical purposes are discussed. Copyright © 2005 John Wiley & Sons, Ltd.
Hydrogen Bonds in Potassium Amide‐Ammonia(1/2), KNH2·2NH3
Authors: Kraus Florian , Korber Nikolaus 
Published: April 2005

AbstractPotassium amide‐ammonia(1/2), KNH2·2NH3 (1) was obtained as a side product in the reaction of distilled potassium with dicesium‐dodecahydro‐closo‐dodecaborate Cs2B12H12 in liquid ammonia at −38 °C. The compound crystallises in the orthorhombic space group C2221 with Z = 4, a = 6.8386(7) Å, b = 9.9525(10) Å, c = 6.5903(6) Å and V = 448.54(8) Å3 as column shaped colorless crystals. The compound contains one‐dimensional infinite potassium‐amide‐ammonia‐strands parallel to the crystallographic c‐axis which are interconnected by interstrand N–H···N‐hydrogen bonds.
Zur Kristallchemie der Oxoiridate
Authors: Müller‐Buschbaum Hanskarl 
Published: April 2005

AbstractDas Review faßt die Kristallchemie der Oxoiridate zusammen. Der überwiegende Teil aller Oxoiridate zeigt Iridium in einer oktaedrischen Umgebung. Unter diesem Aspekt wird die Kristallchemie der Oxoiridate, ausgehend von zueinander isolierten IrO6‐Oktaedern, über Polyedertripel, zu IrO6‐Oktaederketten und IrO6‐Oktaedernetzen geordnet. Iridium ist Bestandteil in Polyederketten der sogenannten „eindimensionalen Oxide”︁, der Perowskite und der K2NiF4‐Struktur. Es bildet Varianten der Ruddlesden‐Popper‐Phasen und ist Bestandteil gestapelter Ir2O9‐Oktaederdoppel und Ir3O12‐Oktaedertripel. Glanzlichter der Oxoiridate sind die metallreichen Alkalimetall‐Oxoiridate, die Iridium in planaren IrO4‐Polygonen aufweisen. Es ist schließlich bemerkenswert, daß Ir6+ durch die Perowskitstruktur stabilisiert wird.
Cd(H2O)2[C6H3(COO)2(COOH)] ‐ Ein zweidimensionales Koordinationspolymer mit Kationenaustauschermerkmalen
Authors: Köferstein Roberto , Robl Christian 
Published: April 2005

AbstractCd(H2O)2[C6H3(COO)2(COOH)] ‐ A Two‐Dimensional Coordination Polymer with Cationexchanger FeaturesMonoclinic single crystals of Cd(H2O)2[C6H3(COO)2(COOH)] have been prepared in aqueous solution at 80 °C. Space group C2/c (no. 15), a = 1973.0(2), b = 910.74(7), c = 1336.81(10) pm, β = 117.897(8)°, V = 2.1230(3) nm3, Z = 8. Cd2+ is coordinated in a moderately distorted pentagonal bipyramidal fashion by five oxygen atoms stemming from the monohydrogentrimesinate anions in the equatorial plane and two water molecules in the apical positions (Cd–O 224.0(2) – 255.0(2) pm). The connection of Cd2+ with [C6H3(COO)2(COOH)]2− yields a two‐dimensional coordination polymer. The atoms of the monohydrogentrimesinate anion form in good approximation a common plane. Thermogravimetric analysis in air shows that the dehydrated compound is stable up to 390 °C. Further decomposition yields CdO.
Synthese, Kristallstruktur und spektroskopische Untersuchungen von Ba5(BO3)3CN
Authors: Schmid Sabine , Schnick Wolfgang 
Published: April 2005

AbstractSynthesis, Crystal Structure, and Spectroscopic Investigations of Ba5(BO3)3CNBarium borate cyanide Ba5(BO3)3CN was synthesized at 1450 °C as coarsely crystalline colorless to pale yellow crystals by the reaction of BaCO3 with BN, barium and tungsten in tungsten crucibles using a radiofrequency furnace. The structure was solved by single‐crystal X‐ray diffractometry (Ba5(BO3)3CN, Z = 4, C2221, a = 1045.3(2), b = 1479.6(3), c = 798.9(2) pm, R1 = 0.0240, 1847 independent reflections, 91 refined parameters). Besides Ba2+ there are trigonal BO33− ions (B‐O 137 – 140 pm) and CN− ions (C‐N 114(2) pm). The presence of CN− ions unequivocally has been determined by observation of a sharp resonance at 2075 cm−1 in the single‐crystal raman spectrum.
Synthese und Charakterisierung der Verbindungen AIrP (A: La – Nd; Sr)
Authors: Löhken Anke , Reiß Guido J. , Johrendt Dirk , Mewis Albrecht 
Published: April 2005

AbstractSynthesis and Characterization of the Compounds AIrP (A: La – Nd; Sr)LaIrP (a = 4.149(2), c = 14.278(6) Å), CeIrP (a = 4.048(2), c = 14.288(11) Å), PrIrP (a = 4.069(2), c = 14.206(9) Å), and NdIrP (a = 4.065(1), c = 14.221(9) Å) are isotypic and crystallize in accordance with the structure determination (single crystal data) with the LaPtSi type structure (I41md; Z = 4). The Ir and P atoms are linked to a three‐dimensional network with a trigonal planar environment, whereas the rare‐earth metal atoms are located in the holes (coordination number 12). We show by DFT band structure calculations, why LaIrP prefers the LaPtSi type structure and not the AlB2 type. SrIrP (a = 6.325(1) Å) was investigated by powder methods and crystallizes with the LaIrSi type structure (P213; Z = 4). The Ir and P atoms are coordinated trigonally and form a three‐dimensional framework with the Sr atoms in the gaps (coordination number 17). The compounds were synthesized by heating mixtures of the elements at 1100 °C.
On the Tammann–Rule
Authors: Merkle Rotraut , Maier Joachim 
Published: April 2005

AbstractThe validity of Tammann's rule is related to the fact that the unavoidable thermal generation of point defects leads to defect‐defect interactions and finally to a breakdown of the structure. It is shown that the onset of this defect avalanche, which can be estimated by a cube root law, roughly corresponds to the Tammann temperature. The investigation of simple compounds corroborates this picture and also the observation of a critical defect concentration. Examples are given that Tammann's rule can be used to systematically search for new solid electrolytes.
Neue Barium‐Antimonid‐Oxide mit den Zintl‐Ionen [Sb]3−, [Sb2]4− und [Sbn]n−
Authors: Boss Michael , Petri Denis , Pickhard Frank , Zönnchen Peter , Röhr Caroline 
Published: April 2005

AbstractNew Barium Antimonide Oxides containing Zintl Ions [Sb]3−, [Sb2]4−, and [Sbn]n−A new kind of chiral chains [Sbn]n− and O2− ions tetrahedrally coordinated by Ba are the characteristic anions in Ba3[Sb4][O] (monoclinic, space group P21/c, a = 696.4(2), b = 1280.7(3), c = 1294.1(3) pm, β = 112.39(1)°, Z = 4, R1 = 0.0399). Similarly, in RbBa4[Sb2][Sb][O], that crystallizes isotypic with KBa4[Sb2][Sb][O] (stuffed Cr5B3‐Typ, tetragonal, space group I4/mcm, a = 893.7(4), c = 1642.7(9) pm, Z = 4, R1 = 0.0508), the oxide ions occupy tetrahedral voids. The Zintl ions in this case are isolated [Sb]3− anions and dumbbells [Sb2]4− respectively. The new hydrid‐oxides Ba8[M]4[O][H]2 (M=Sb/Bi, tetragonal, space group I4/mmm, a = 515.34(12)/519.12(12), c = 3791.7(3)/3837.6(3) pm, Z = 4, R1 = 0.0319/0.0460) and Rb2Ba6[Sb2]2[Sb][O][H] (tetragonal, space group I4/mcm, a = 879.71(4), c = 2742.4(2) pm, Z = 4, R1 = 0.0592) can be structurally derived from the oxides Ba4Sb2O and RbBa4[Sb2][Sb][O] by intercalation (chemical twinning) of hydride antimonides. The synthesis of these air sensitive compounds exhibiting dark metallic luster was performed from melts of elemental Rb, Ba and Sb/Bi using Sb2O3/Bi2O3, BaH2 and Ba(OH)2 as sources for oxide/hydride. The detailed comparison of the structures and the results of FP‐LAPW band structure calculations show that the title compounds are electron precise Zintl phases with distinct band gaps.
Electron Holography, a Versatile Tool for Characterization of Materials: Fluoroapatite‐Gelatine‐Composites, SiC and SiO2
Authors: Simon Paul , Lichte Hannes , Mönter Damian , Reschetilowski Wladimir , Valera Anibal , Carrillo‐Cabrera Wilder 
Published: April 2005

AbstractIn recent years, electron holography developed into a powerful tool in materials characterisation. It allows to measure electrical or magnetic micro‐ and nanofields. Besides this, areas of different chemical composition, density or thickness can be distinguished without artefacts, such as lattice displacements or Fresnel fringes.In this report, a short description of the method is given and new applications of electron off‐axis holography in the determination of density or thickness differences are presented. In composite biominerals, due to density variations we could clearly reveal the structure of the organic part of these aggregates. Further on, differences of domain sizes and porosities in para‐crystalline SiC were detected, which play a decisive role for their optical and electronic properties. Phase images of mesoporous silica clearly show the hexagonal and lamellar shape of the porosities without blurring. Thus, width and thickness of the walls can be determined, which is hardly achieved with other methods.
Ag12Te6S: A Contribution to Open Problems in the Crystal Chemistry of Complex Non‐Metallic Filled Frank‐Kasper Phases
Authors: Mikus H. , Deiseroth H. J. 
Published: April 2005

AbstractThe air stable gray‐metallic Ag12Te6S is a substitution variant of synthetic Ag5−xTe3 (mineral name: stutzite, range of x controversial) crystallizing in the space group $P{\bar 6}$ (Z = 3) with lattice parameters a = 13.413(2) Å, c = 8.452(2) Å. All non‐metal atoms in this complex solid are topologically arranged like Zr and Al atoms in the Frank‐Kasper phase Zr4Al3 forming a system of interpenetrating Frank‐Kasper polyhedra with coordination numbers 12, 14 and 15. Symmetry relations between stutzite, Zr4Al3 and the title compound are presented. The interpenetration of Frank‐Kasper polyhedra results in a complex three‐dimensional network of distorted tetrahedra intimately connected by common corners, edges, and faces (tetrahedral or topological close packing). A specific disorder problem which complicates the compositional and structural characterization of stutzite considerably is not present in the title compound. Whereas stutzite contains single Te2−, (Te2)2−(ordered), and additional (Te2)2− sharing a poorly resolved number of common crystallographic positions with further Te2−, in the title compound ordered Te2−, (Te2)2−, and S2− are found only, not leaving any ambiguity for the number of charge compensating Ag+ ions. Except of a new silver position in close vicinity to the S2−, the distribution of the strongly disordered Ag+ in the title compound is only slightly different from that in stutzite and is not further discussed in this paper. Literature reports concerning a c‐axis doubling cannot be confirmed neither for stutzite nor for the title compound.
Nanocrystalline Ferrites Prepared by Mechanical Activation and Mechanosynthesis
Authors: Šepelák Vladimir , Bergmann Ingo , Kipp Stephan , Becker Klaus Dieter 
Published: April 2005

AbstractAt present, the high‐energy milling method becomes widely used for the preparation of nanocrystalline materials due to its relative simplicity and availability. In this research report, selected examples are presented of the preparation of nanoscale spinel ferrites by mechanical activation and mechanosynthesis. Nanosized particles of mechanochemically prepared spinel ferrites are structurally and magnetically disordered due to the non‐equilibrium cation distribution and non‐collinear spin arrangement. As a consequence, they exhibit interesting physical and chemical properties markedly different from those of their bulk counterparts. Several interesting features are involved in the work, e.g., superparamagnetism, an enhanced chemical reactivity, an irreversible magnetic behaviour, an enhanced magnetic ordering temperature, and an altered (reduced or enhanced) saturation magnetization in comparison with the corresponding bulk materials. Taking into account the considerable relevance of the thermal stability of nanoscale complex oxides to nanoscience and nanotechnology, results on the response of mechanochemically prepared spinel ferrites to changes in temperature will also be presented.
Zur Stabilisierung von Suboxidphasen durch Carbidionen: Die Kristallstruktur von Sr21Si2O5C6
Authors: Knoth Markus , Rößler Ute , Eisenmann Brigitte 
Published: April 2005

AbstractOn the Stabilization of Suboxide Phases by Carbide Ions: The Crystal Structure of Sr21Si2O5C6Metallic brass‐coloured crystals of Sr21Si2O5C6were isolated from samples starting from the educts Sr : SiO : C = 21 : 2 : 6 heated under argon atmosphere in corundum crucibles up to 1150 K. The air‐sensitive compound crystallizes in the cubic system, space group $F d \: \overline{\mathit{3}} \: m, a$ = 1914,56(19) pm, Z = 8. In the crystal structure the Si, O and C atoms are coordinated only by Sr atoms forming distorted icosahedra around Si and distorted octahedra around O and C. The compound can be classified as an electron precise Zintl phase according to (Sr2+)21(Si4−)2(O2−)5(C4−)6.
Solvothermalsynthese: Synthese und Strukturaufklärung der Nb‐Cu‐S‐Komplexe [NbCu5S4Cl2(dppm)4]·5CH3CN und (NEt4)2[Nb10Cu12Cl4S30(dpppr)6]·6MeCN
Authors: Feuerhake Robert , Reiser Benjamin K. H. , Sommer Heino , Fenske Dieter 
Published: April 2005

AbstractSolvothermal Synthesis: Synthesis and Structure Elucidation of the Nb‐Cu‐S Complexes [NbCu5S4Cl2(dppm)4]·5CH3CN and (NEt4)2[Nb10Cu12Cl4S30(dppr)6]·6MeCNIn the presence of bis(diphenylphosphanyl)propane (dppr) and bis(diphenylphosphanyl)methane (dppm), the solvothermal reaction of the thioniobate (NEt4)4[Nb6S17]·3MeCN with CuCl gives the new niobium copper sulfides [NbCu5S4Cl2(dppm)4]· 5CH3CN (1) and (NEt4)2[Nb10Cu12Cl4S30(dpppr)6]·6MeCN (2). The molecular structures of these compounds are determined by the chelate effect of the bidental phosphine ligands.
Chemical Diversity in View of Property Generation by a New Combinatorial Approach
Authors: Hulliger Jürg , Aslam Awan Muhammad , Trusch Bernhard , Samtleben Till A. 
Published: April 2005

AbstractEven the exploration of the phase space given by a large number N (N ≤ 61) of components but a limited number q (q ≤ 6) of elements Ei in e.g. metal oxides Ex1>(1)Ex2(2)…Exq(q)Oy is a demanding task and needs a combinatorial approach which, by setting up starting conditions for solid‐state reactions, is taking favour of efficient combinatorial functions. Estimations showed that within a single sample prepared by mixing N starting components, the number of local reaction centres (configurations) is exceeding the number of phase systems. A huge amount of about 1012 starting grains for a sample of one cm3 provides population of each configuration many times. The distribution for the grain size and the number of grains building up a configuration allow to explore compositional fields in phase diagrams of the order q. The single sample concept (SSC) is particularly of interest for property oriented syntheses, where e.g. magnetic materials are produced in minor quantities. Magnetic chromatography is applied to extract ferromagnetic materials formed by the SSC. A horizontal separator is presented and applied to extract new ferromagnetic Fe‐based oxides from SSC reaction mixtures.
Synthesis and Characterization of Cobalt Monosilicide (CoSi) with CsCl Structure Stabilized by a β‐SiC Matrix
Authors: Walter Dirk , Karyasa I W. 
Published: April 2005

AbstractIn the Co/Si/C system a new CoSi (CsCl type) modification besides ß‐SiC and carbon is observed after a sintering process of the elements at a temperature of 1400 °C (4 h; vacuum). The structure of the cobalt monosilicide (CsCl type) was determined by X‐ray powder diffraction methods and subsequent Rietveld refinement. CoSi (CsCl type) crystallizes in the cubic space group $Pm{\bar 3}m$ (no. 221) with the lattice parameters a = 281.62(2) pm (V= 22.337(7) × 106 pm3). However, in the Co/Si system only the well known ε‐CoSi (FeSi type) is observed at the same reaction conditions. It is supposed that β‐SiC takes an important role in stabilizing the CoSi (CsCl type). Electron microscopy experiments (SEM and EDX) confirm that the cobalt monosilicide is surrounded by a β‐SiC matrix containing a small amount of carbon. The thermal stability of the synthesized samples was studied. Furthermore, the density of states (DOS) was calculated.
Characterization of Mo‐V‐W Mixed Oxide Catalysts by ex situ and in situ X‐Ray Absorption Spectroscopy
Authors: Schimanke Guido , Martin Manfred , Kunert Jan , Vogel Herbert 
Published: April 2005

AbstractMixed oxides in the system Mo‐V‐W‐O are important catalysts for partial oxidation reactions, e.g. the partial oxidation of acrolein to acrylic acid. Multiphase catalysts of the overall composition Mo8V2WyOx were prepared by spray drying and crystallization. The charge states of the potential catalytic centers Mo, V and W were investigated by ex situ X‐ray absorption spectroscopy (XAS). In the as prepared samples the cations exist essentially as Mo6+, V5+ and W6+. Exposure of the as prepared samples to acrolein results in a reduction of both Mo6+ and V5+ whereas W6+ is inert. Re‐oxidation with oxygen causes a reversible oxidation of Mo and V. The kinetics of the reduction and re‐oxidation processes of the catalyst samples was studied at a temperature of 500 °C by in situ X‐ray absorption spectroscopy at the Mo K‐edge with carbon monoxide and oxygen as reducing and oxidizing gases. The in situ experiments show that the reduction of Mo6+ in CO is about one order of magnitude slower than the subsequent re‐oxidation in oxygen.
Replacement of the aortic valve after the arterial switch operation
Authors: Alexi-Meskishvili Vladimir , Photiadis Joachim , Nürnberg Jan-Hendrik 
Published: April 2005

An 11-month-old infant had undergone a primary arterial switch operation, including the Lecompte maneuver, for correction of discordant ventriculo-arterial connections and closure of an accompanying ventricular septal defect.At discharge, there were no signs of aortic valvar incompetence. Regurgitation across the aortic valve was detected first at the age of 2 years, and then increased progressively, as documented by serial echocardiographic studies. There had been no history of bacterial endocarditis. At the age of 10 years, echocardiography revealed severe aortic valvar incompetence. At operation, the aortic valve had three leaflets, all of which were short, with very restricted movement. Absence of sufficient leaflet tissue precluded a durable valvar reconstruction, so the aortic valve was replaced with a 21 mm mechanical prosthesis. Histological examination of the removed leaflets revealed nodular swelling due to mucous changes of the matrix, as well as fibrous alteration and formation of scar tissue, including areas of fibroblastic and capillary proliferation. There were no signs of calcification or acute inflammatory changes. Improvement of left ventricular function was observed both early postoperatively and later on. Our observation shows that aortic valvar incompetence after an arterial switch operation can be caused by degenerative changes of the neo-aortic leaflets, which prevent plastic reconstruction of the valve, necessitating valvar replacement.