bluuebunny/crossref_metadata_2025 huggingface dataset:
K2TiS3, ein neues Thiotitanat(IV) mit fünffach koordiniertem Titan / K2TiS3, A New Thiotitanate(IV) with Pentacoordinate Titanium
Authors: Klepp Kurt O.
Published: March 2015

Fibrous red crystals of the new compound K2TiS3 were obtained by reacting K2S, Ti and S at 1070 K. K2TiS3 is monoclinic, space group C 2/c with a = 11.667(6) Å, b = 8.325(4) Å, c = 6.494(4) Å, β = 9 i.81(4)°, Z = 4. The crystal structure was refined to a conventional residual of 0.070. The atomic arrangement is characterized by pseudo-one-dimensional -
∞-[TiS3]2− chains formed by distorted TiS5 square pyramids sharing opposite edges of their basal planes. The structure - though closely related to that of Cs2TiS3 - is of a new type.
Silaheterocyclen, XIII Erzeugung und Cycloadditionsverhalten von 1,3-Diaza-2,4-disila-und 1.3-Disilacyclobutanen mit exocyclischer SiC-Doppelbindung Silaheterocycles, XIII / Formation and Cycloaddition Reactions of 1,3-Diaza-2,4-disila-and 1.3-Disilacyclobutanes Containing an Exocyclic SiC Double Bond
Authors: Auner Norbert , Penzenstadler Erika
Published: March 2015

The silenes A and B are formed by reacting 1,3-ditbutyl-2,4-dichloro-2,4-divinyl-1,3-diaza- 2.4-disilacyclobutane (2) and 1,3-dichloro-2,4-dineopentyl-1,3-divinyl-1,3-disilacyclobutane (15) with LiBut in n-pentane in the temperature range from −10 to 0 °C. The reaction primarily leads to the corresponding α-lithioadducts (addition of LiBut to the vinyl group of 2 and 15), and with subsequent 1,2-LiCl elimination yields A and B as intermediates. A can be trapped by polar reagents Me3SiX (X = OMe, OSO2CF3) as well as by organic dienes which add across the Si = C bond; in the absence of a trapping agent the spiro compound 6 is isolated. The silenes A and B differ in their cycloaddition behaviour to butadienes, norbornadiene and cyclohexa-1,3-diene: Whereas for A the regioselective [2 + 2]-cycloaddition to yield monosilacyclobutane derivatives is preferred due to electronic reasons, the reaction of B leads mainly to Diels-Alder products. Thus, A is quite comparable in its reactivity to dichloroneopentylsilene, while B reacts like its diorgano substituted analogues R2Si = CHCH2But (R = Me, But or Ph).
Übergangsmetall-substituierte Diphosphene, XXIV [1] Cheletrope [1+4]-Cycloaddition von Azodicarbonsäureestern und -amiden an das metallsubstituierte Diphosphen ( η5-C5Me5)(CO)2Fe - P = P - Mes* (Mes* = 2,4,6-tBu3C6H2). Struktur von Transition Metal Substituted Diphosphenes, XXIV [1] Cheletropic [1+4] Cycloaddition of Azodicarboxylic Esters and Amides to the Metal Substituted Diphosphene
Authors: Weber Lothar , Bastian Holger , Müller Achim , Bögge Hartmut
Published: March 2015

The diphosphenyl complex (η5 -C5Me5)(CO)2Fe -P = P -Mes* (1) (Mes* = 2,4,6tBu3C6H2) reacts with equimolar amounts of the azo compounds R(O)C -N = N - C(O)R (2a: R = OEt; 2b: R = O-tBu; 2c: R = OCH2C6H5; 2d: R = NC5H10) in a cheletropic [1 +4] cycloaddition to afford stereoselectively the metal substituted oxadiazaphospholenes

The products have been characterized by elemental analysis as well as by spectroscopic data (IR, 1H, 13C, 31P NMR, MS). The molecular structure of 3a has been elucidated by single crystal X-ray analysis.
N,N′,N′-Trimethylethylendiamin-substituierte Phosphor(III)-Verbindungen und deren Oxidation zu Derivaten mit tetra- und pentakoordiniertem Phosphor / N,N′,N′-Trim ethylethylenediamine-Substituted Phosphorus(III) Com pounds and their Oxidation to Derivatives with Four-and Five-Coordinated Phosphorus
Authors: Kaukorat Thomas , Schmutzler Reinhard
Published: March 2015

A study was made of the intramolecular donor-acceptor interaction in N,N′,N′-trimethylethylenediamine- substituted phosphorus compounds, involving λ3-, λ4- and λ5-phosphorus atoms, as a function of the nature of the substituents at phosphorus. The reaction of N-trimethylsilyl-N,N′,N′-trimethylethylenediamine (1) with (PriO)2PCl furnished the acyclic, trimethylethylenediamine-substituted phosphorus(III) compound 4. There is no NMR spectroscopic evidence for an intramolecular donor-acceptor interaction between the phosphorus atom and the nitrogen atom of the dimethylamino group in 4. The oxidation of the trivalent phosphorus atom in 4 and in the related compound 5 by sulfur, selenium, tetrachloroo- benzoquinone, and hexafluoroacetone led to the corresponding λ4P compounds 6 - 9 and to the λ5P compounds 10 and 11. No intramolecular donor-acceptor interaction could be detected in any of these products. There was no reaction between 5 and elemental tellurium. The reaction products were characterized by NMR spectroscopy, mass spectrometry, and by elemental analysis.
Synthese und Kristallstruktur des Dichloroselenonitren-Komplexes (PPh4)2[WCl5(NSeCl2)] / Synthesis and Crystal Structure of the Dichloro-selenonitrene Complex (PPh4)2[WCl5(NSeCl2)]
Authors: Vogler Stefan , Dehnicke Kurt
Published: March 2015

The title compound has been prepared by the reaction o f [WCl4(NSeCl)]2 with PPh4Cl in CH2Cl2 solution. It forms red crystals, which were characterized by an X-ray structure determination. Space group P21/c, Z = 4, 3856 observed unique reflections, R = 0.073. Lattice dimensions at 25 °C: a = 2266.0(5), b = 1121.0(2), c = 2013.0(4) pm, β = 109.66(3)°. The structure consists o f PPh4
+ ions and anions [WCl5(NSeCl2)]2-, in which the tungsten atom is surrounded in a distorted octahedral way by five chlorine atoms and by the nitrogen atom of the (NSeCl2)3- ligand. The W = N = SeCl2 group is characterized by WN and SeN double bonds; the selenium atom has a pseudo trigonal-bipyramidal coordination with the N atom and two lone pairs in equatorial and the chlorine atoms in axial positions.
Alternativ-Liganden XXVIII. Neue Komplexe M(CO)4L mit Dipodliganden des Typs R2M′(OCH2PMe2)x(CH2CH2PMe2)2-x(M = Cr, Mo, W; M′ = Si, Ge; R = Me, Ph; x = 0 - 2 ) / Alternative Ligands XXVIII. Novel Complexes M(CO)4L with Dipod Ligands of the Type R2M'(OCH2PMe2)x(CH2CH2PMe2)2-x(M = Cr, Mo, W; M' = Si, Ge; R = Me, Ph; x = 0 -2)
Authors: Grobe Joseph , Krummen Anita , Krebs Bernt , Läge Mechtild
Published: March 2015

The coordinating properties of dipod ligands of the type R2M′(OCH2PMe2)x(CH2CH2PMe2)2-x(R = Me, Ph; M' = Si, Ge; x = 0 -2) have been investigated by the preparation of the novel cis-M (CO)4L complexes (M = Cr, Mo, W). They are obtained under mild conditions in cyclohexane or n-hexane solution by the reaction of the norbornadiene precursors M(CO)4NBD with the corresponding ligands. In case of the Ge containing ligands the dilution principle was used to improve the yields of the mononuclear derivatives. The rate of the NBD replacement is mainly determined by the central atom M (Mo > W > Cr) and only little by R, M' or x . The new com pounds have been characterized by analytical (C, H) and spectroscopic investigations (1H, 31P NMR, IR, MS). The ligand properties are discussed on the basis of spectroscopic data (in particular coordination effects) and the molecular structure of the complexes Cr(CO)4[Ph2Si(OCH2PMe2)2] (12) and Mo(CO)4Me2Ge(CH2CH2PMe2)2] (28) obtained by X-ray diffraction studies.
Die Schmelzdiagramme für die Systeme aus (CH3)3SiBr und den sechs Lutidinen / The Phase Diagrams of the Systems of (CH3)3SiBr and the Six Lutidines
Authors: Hensen Karl , Wagner Peter
Published: March 2015

The phase diagrams of the systems of trimethylbromosilane and the isomeric lutidines are shown. The existence of the congruently melting addition compounds (CH3)3SiBr ∙ (3,4-lutidine), (CH3)3SiBr (3,5-lutidine) and the incongruently melting addition compounds (CH3)3SiBr • (2,3-lutidine)2, (CH3)3SiBr • (2,3-lutidine), (CH3)3SiBr (2,4-lutidine), ((CH3)3SiBr)2 • (2,4-lutidine), (CH3)3SiBr • (2,5-lutidine)2, (CH3)3SiBr • (2,5-lutidine), (CH3)3SiBr (2,6-lutidine)2 could be proved.
Sc5Re2C7, a Complex Carbide with C3-Units
Authors: Pöttgen Rainer , Jeitschko Wolfgang
Published: March 2015

The title compound was obtained by arc melting of the elemental components and subsequent annealing in a high frequency furnace. It crystallizes with the orthorhombic space group Cmmm, a = 779.26(7) pm, b = 1362.0(1) pm, c = 320.62(3) pm, V = 0.3403 nm3, Z = 2. The structure was determined from single-crystal X-ray data and refined to a residual of R = 0.021 (692 F values and 21 variables). It is closely related to the NaCl-structure. Three of the seven carbon atoms per formula unit form linear C3 -units with C-C bond lengths of 134 pm. They are coordinated to ten Sc atoms forming bicapped quadratic prisms. Additional isolated C atoms are located in octahedral voids formed by four Sc and two Re atoms. Together with the Re atoms they form two-dimensionally infinite [Re2C4
11-]n polyanions. The Re atoms have highly distorted tetrahedral carbon coordination with Re -C bond lengths of 200 and 208 pm corresponding to bond orders of about two. This coordination seems to be compatible with the 18-electron rule. The near-neighbour coordination of the Re atoms is assymmetric. It is suggested that this is due to the space requirements of nonbonding electrons. Samples of Sc5Re2C7 are semiconducting and weakly paramagnetic.
Ag20O33H22(ClO4)4 – ein Hybrid aus Silberoxidclathrat und Gashydrat / Ag20O33H22(ClO4)4 – A Hybrid of Silver Oxide Clathrate and Gashydrate
Authors: Fischer Peter , Jansen Martin
Published: March 2015

By electrochemical oxidation of an aqueous silver perchlorate solution (c(Ag+) = 2.0 M) a new compound with the formula Ag20O33H22(ClO4)4 was obtained. The crystal structure has been determined by use of single-crystal diffractometer data (Fd 3̄̄ m , a = 20.234(1 )Å , Z = 8). It contains H22O17
12-clusters, which exhibit close relationships to the structures of gas hydrates. The clusters are linked through a three-dimensional Ag-O-network being similar to that one present in Ag7O8X.
K2Sn4Se8 -ein gemischtvalentes Selenostannat / K2Sn4Se8 -A Mixed-Valent Selenostannate
Authors: Klepp K. O. , Fabian F.
Published: March 2015

Transparent, ruby red crystals of the new compound K2Sn4Se8 were obtained from K2Se, Sn and Se by high temperature synthesis. K2Sn4Se8 is monoclinic, space-group Cm with a = 6.436(3) Å, b = 18.934(9) Å, c = 7.417(5) Å, β = 96.26(2)°; Z = 2. The crystal structure was refined to a conventional R of 0.022 (Rw = 0.018).

In K2Sn4Se8 the tin atoms have two distinct oxidation states +2 and +4. Sn(IV) is tetrahedrally coordinated by Se, Sn(II) has a pseudo-trigonal bipyramidal coordination MA4E which reveals a pronounced stereo-activity of the lone pair of electrons.

In the crystal structure the Sn(IV)Se4-tetrahedra share common apices, yielding open sheets which are separated from each other by the alkali cations, but connected via the Sn(II) centers.
Na4SnSe4 und K4SnSe4, zwei neue Selenostannate mit isolierten Anionen / Na4SnSe4 and K4SnSe4, Two New Selenostannates with Discrete Anions
Authors: Klepp Kurt O.
Published: March 2015

Transparent yellow single crystals of Na4SnSe4 and K4SnSe4 were prepared by reacting stoichiometric powdered mixtures of the binary compounds Na2Se or K2Se, Sn and Se at 850 K. Na4SnSe4 is tetragonal, s.g. P4̄21c, with a = 8.165(2) Å, c = 7.268(2) Å, Z = 2. K4SnSe4 is orthorhombic, s.g. Pnma, with a = 14.714(7) Å, b = 10.323(3) Å, c = 8.248(6) Å, Z = 4. The crystal structures were refined to conventional residuals of 0.058 and 0.031, respectively. Both com pounds are characterized as salts with discrete tetrahedral selenostannate anions. Na4SnSe4 is isostructural with Na4SnS4, K4SnSe4 is of a new type. The observed Sn -Se bond lengths range from 2.494 Å to 2.536 Å.
LiSr2[CoN2]: Ein Nitridocobaltat(I) mit gestreckten Anionen [CoN2]5- / LiSr2[CoN2]: A Nitridocobaltate(I) with Linear Anions [CoN2]5-
Authors: Höhn Peter , Kniep Rüdiger
Published: March 2015

LiSr2[CoN2] (tetrag., P42/mnm (Nr. 136); a = 524.4(1) pm, c = 730.7(2) pm; Z = 2) was prepared by reaction of mixtures of Li, Sr2N and Co (molar ratio 6:3:1) in tantalum crucibles under nitrogen (1 atm) at 850 °C. The crystal structure (α-Li3[BN2]-type) contains linear anions [Co1N2]5- (Co-N : 181.0(5) pm) which are isostructural to [Fe11N2]4- (Li4[FeN2]) as well as to the maingroup species CO2 and [BN2]3-.
Sign-Determination of Spin-Spin Coupling Constants in tert-Butylphosphaalkyne
Authors: Wrackmeyer Bernd
Published: March 2015

The signs o f the coupling constants 1J(31P≡13C) ( > O ) , J(31P13C) ( > O ) , 3J(31P13C) ( > O ) and 4J(31P1H) ( > O ) in tert-butyl-phosphaalkyne (1) were determined by selective 1H {31P} NMR experiments and two-dimensional (2 D ) 13C/1H heteronuclear shift correlations based on nJ(13C1H ) (n = 1,2,3), confirming the previously assumed positive sign of 1J( 31P≡13C) in phosphaalkynes.
Headspace Constituents of Vetiver Oil
Authors: Nikiforov Alexej , Buchbauer G. , Jirovetz L. , Remberg B. , Remberg G.
Published: March 2015

Abstrac

t By headspace analysis of the essential oil of Vetiver hitherto sixteen not described volatile constituents, mainly monoterpenes, could be identified. For these investigations GC -FID , GC-MS, GC-FTIR and the GC-sniffing-technique were used.
Neue metallorganisch substituierte Indium-Chalkogen-Verbindungen mit In4E4-Heterokubangerüst (E = S, Se,Te)/New Organoindium Chalcogen Compounds with In4E4 Heterocubane Structure (E = S, Se,Te)
Authors: Merzweiler Kurt , Rudolph Frank , Brands Ludwig
Published: March 2015

The reaction of organometallic indium halides R2InBr and RInCl2 (R = {Cp(CO)2Fe}, {Cp(CO)3Mo}) with silylated chalcogens E(SiMe3)2 (E = S, Se, Te) leads to the formation of cage compounds which contain a central In4E4 cube. The structures of [{Cp(CO)2Fe}4In4Se4] (1), [{Cp(CO)3Mo}4In4S4] (2), [{Cp(CO)2Fe}4In4S4] (3) and [{Cp(CO)3Mo}4In4Te4] (4) were determined by X-ray crystallography.
Synthese von Thiacycloocteno-1,2,3-selenadiazolen/Synthesis of Thiacycloocteno-1,2,3-selenadiazoles
Authors: Schuhmacher Hans , Meier Herbert
Published: March 2015

The isomeric thiacyclooctanones 1b-d are transformed via the semicarbazones Z-2b,c, E-2b,c and 2d to the bicyclic 1,2,3-selenadiazoles 3b,c, 3b´,c´ and 3d. The ring closure reaction with SeO2 is highly regioselective and doesn’t depend on the Z /E -ratio of the semicarbazones. A detailed 1H and 13C NMR study was made for 1, 2 and 3.
Notizen: Synthese und NMR-spektroskopische Eigenschaften von Benzyl-2,3-anhydro-4-desoxy-4-[N]-pyridinium-pyranosiden/Synthesis and NMR Spectroscopic Properties of Several Benzyl 2,3-Anhydro-4-deoxy-4-[N]-pyridinium Pyranosides
Authors: Kowollik Wolfgang , Voelter Wolfgang
Published: March 2015

Benzyl 2,3-anhydro-4-0-triflyl-β-L-ribopyranoside (1) and benzyl 2,3-anhydro-4-O-triflyl-α-D-lyxopyranoside (3) react with pyridine to give benzyl 2,3-anhydro-4-deoxy-4-[N]-pyridinium - α-D-lyxopyranoside triflate (2) and benzyl 2,3-anhydro-4-deoxy-4-[N]-pyridinium -β-L-ribopyranoside triflate (4). Similar reactions with thiourea and dimethylsulfoxide are mentioned. Compound 2 is stable at room temperature, whereas compound 4 decomposes in a few hours (neighbouring group effect). The 13C NMR assignments of 2 are proved by 13C {1H} single frequency decoupling experiments.
Chlor(trifluorphosphan)gold(I), eine einfache flüchtige Notizen: Goldverbindung/Chloro(trifluorophosphane)gold(I), a Simple Volatile Gold Compound
Authors: Fuß Werner , Rühe Martin
Published: March 2015

(PF3)AuCl was prepared from PF3 and Au2Cl6 in SOCl2 as a solvent. It is more stable than the analogous CO complex. It has a vapor pressure of about 10-4 mbar at room temperature. Its IR , NMR and mass spectra are reported.
Kristallstrukturen von Li6MgBr8 und Li2MgBr4/Crystal Structure of Li6MgBr8 and Li2MgBr4
Authors: Schneider Michael , Kuske Peter , Lutz Heinz Dieter
Published: March 2015

The crystal structures of the fast ionic conductors Li6MgBr8 and Li2MgBr4 oC 14 and cF 56 were determined by single crystal X -ray diffraction and neutron powder studies, respectively. At ambient temperature, Li6MBr8 (M = Mg, Mn) crystallize in a Suzuki-type structure (space group Fm3̄̄̄ m , Z = 4, Li6MgBr8: a = 1098.0(1) pm, 114 unique reflections, R = 0.037). Li2MgBr4 oC 14 crystallizes in a SnMn2S4-type structure (space group Cmmm , Z = 2, a = 777.94(2), b = 1104.25(4), and c = 386.55(1) pm , RI, = 0.073, 318 K), the high-temperature polymorph (HTM I) in the Li2MnBr4 cF 56 type (space group Fd 3 m , Z = 8, a = 1124.55(4) pm , RI , = 0.052, 673 K). These structure types are more or less ordered NaCl superstructures. The thermal ellipsoids of the lithium ions are discussed in terms of the conduction pathways and the order-disorder phase transitions observed.
Kristallstruktur von Bromchlormethyleniminium-hexachloroantimonat BrClC=NH2
+SbCl6
-/ Crystal Structure of Bromochlorom ethyleneiminium Hexachloroantimonate BrClC = NH2+SbCl6
-
Authors: Minkwitz R. , Meckstroth W. , Preut H.
Published: March 2015

Bromochloromethyleneiminium hexachloroantimonate BrClC = NH2
+SbCl6
- crystallizes in the space group P 2 l /c w ith a = 979.6(5), b = 1140.5(5), c = 2162.1(10) pm , β = 102.45(4)° and Z = 8. It is isostructural with Cl2C = NH2
+SbCl6
-.
Zur Kenntnis von Gadolinium(III)-sulfit Dihydrat Gd2(SO3)3· 2 H2O/ On the Existance of Gadolinium (III)-sulfite Dihydrate Gd2(SO3)3 · 2H2O
Authors: Hummel Hans-Ulrich , Joerg Petra
Published: March 2015

Different hydrates of Gd2(SO3)3 are obtained depending on preparation conditions. For preparation of Gd2(SO3)3, gaseous SO2 is passed through a suspension of Gd2O3 in H2O at room temperature until a clear solution is formed. Upon immediate heating to about 100 °C a mixture of Gd2(SO3)3 · 2H2O and Gd2(SO3)3 · 3H2O is formed. If the boiling procedure is performed after 6 days, a pure product consisting of the trihydrate is obtained. The different phases are identified by REM, DTA -TG -investigation and X-ray powder analysis. The X-ray powder pattern of Gd2(SO3)3 · 2H2O is consistent with patterns of isotype Ln2(SO3)3 · H2O were Ln = Pr, Nd, Sm and Eu.
Electronic Structure Determination of Co(II)-Nucleotide Complexes by Using Magnetic and Mößbauer Emission Measurements
Authors: Caubet A. , Moreno V. , Labarta A. , Tejada J.
Published: March 2015

Mößbauer emission spectroscopic and susceptibility measurements of several Co(II)-nucleotide complexes have been carried out. The electronic structure derived from these data for the Co(II) central cation has been related to the distortion and the symmetry of its environment. The susceptibility data are indicative of short antiferromagnetic ordering in the majority of the samples. For the hydrated Co-5′UMP (5′-uridine monophosphate) and Co-5′CMP (5′-cytidine-monophosphate) complexes, magnetic models involving Co(II) dimers and linear chains, respectively, are proposed to explain the susceptibility data observed below 50 K.
Hexafluoraceton als Schutzgruppen- und Aktivierungsreagenz in der Aminosäure- und Peptidchemie N-Substituierte Glycinderivate aus Iminodiessigsäure/Application of Hexafluoroacetone as Protecting and Activating Reagent in Amino Acid and Peptide Chemistry N -Substituted Glycine Derivatives from Iminodiacetic Acid
Authors: Burger Klaus , Neuhauser Horst , Worku Anteneh
Published: March 2015

3-Carboxymethyl-2,2-bis(trifluoromethyl)-oxazolidin-5-one 2, obtained on reaction of iminodiacetic acid 1 and hexafluoroacetone, represents a preparatively useful intermediate for the synthesis of unsymmetrically substituted derivatives of the dicarboxylic acid 1. The N-substituted glycine derivatives obtained are interesting candidates for peptide modification.
Synthesen und Kristallstrukturen der Lithiumphosphide {Li(DME)[P(t-Bu)2]}2 und [Li(DME)PPh2]∞ / Syntheses and Crystal Structures of the Lithium Phosphides {Li(DME)[P(t-Bu)2]}2 and [Li(DME)PPh2]∞
Authors: Stieglitz Gudrun , Neumüller Bernhard , Dehnicke Kurt
Published: March 2015

The title compounds have been prepared by the reaction of n-butyllithium with the corresponding diorganophosphanes HPR2 (R = t-Bu, Ph) in DME solutions. Both compounds were characterized by crystal structure determinations.

{Li(DME)[P(t-Bu)2]}2: Space group P 1̄, Z = 1, 2027 observed unique reflections, R = 0.055. Lattice dimensions at -80 °C: a = 879.9(3), b = 986.3(1), c = 1064.0(2) pm, α = 70.69(1)°, β = 70.63(2)°, γ - 69.89(2)°. The compound forms centrosymmetric dimers of symmetry Ci with Li-P bond lengths of 260.0 and 257.3 pm for the Li2P2 four-membered ring.

[Li(DME)PPh2]∞: Space group P21/n, Z = 4. 3437 observed unique reflections, R = 0.055. Lattice dimensions at - 80 °C: a = 1034.8(2), b = 812.48(9), c = 1978.4(3) pm, β = 103.30(2)°. The compound forms polymeric chains via LiP bridges with Li-P bond lengths o f 256.3 and 254.1 pm.
On the Hydrolysis of Monoorganotin Trihalides, V**. Solid State 119Sn-NMR and IR Spectra of the [(i-PrSn)12O14(OH)6]2+ Ion
Authors: Reuter Hans , Sebald Angelika
Published: March 2015

The 119Sn-CPMAS-NMR spectra of the complex [(i-PrSn)12O14(OH6)]2+ ion were recorded for two different salts having twelve and four different tin atoms in the asymmetric unit, respectively. Both spectra agree very well with X-ray crystallographic predictions, and thus demonstrate the great sensitivity of heavy nuclei NMR spectroscopy to subtle structural changes. Infrared spectroscopy is shown to be a suitable routine detection method for the identification of this ion in the solid state.
On the Space Group of Cesium Perbromate, CsBrO4
Authors: Rögner Peter , Schießl Ulrike , Range Klaus-Jürgen
Published: March 2015

The correct space group of cesium perbromate, CsBrO4, is I41/amd and not I41/a as previously reported. The compound is isostructural with α-CsReO4, the high-temperature modification of cesium perrhenate. By analogy with CsReO4 and CsIO4, a phase transformation to a low-tempera­ture modification is predicted for CsBrO4.
Ein Orthoperrhenat mit flächenverknüpften ReO6-Oktaedern: Hochdrucksynthese und Kristallstruktur von K3NaRe2O9 / An Orthoperrhenate with Face-Sharing ReO6 Octahedra: High-Pressure Synthesis and Crystal Structure of K3NaRe2O9
Authors: Range Klaus-Jürgen , Atzesdorfer Alexandra
Published: March 2015

The title compound was prepared by high-pressure reaction of rhenium metal with technical grade (i.e., Na containing) KO2 in a modified Belt-type apparatus (20 kbar, 1000 °C, 60 min, Au capsule). The amber-coloured crystals are very hygroscopic and decompose rapidly when exposed to air. K3NaRe2O9 crystallizes hexagonally, space group P63/mmc, with a = 6.012(1), c = 14.342(14) Å, c/a = 2.386 and Z = 2. The structure was refined to R = 0.031, Rw = 0.023 for 422 independent, absorption-corrected reflections with l > σ (I). K3NaRe2O9 is isostructural with 6H-BaTiO3, a perowskite variant, and contains Na and Re in octaedral coordination. Two ReO6 octahedra are face-sharing, thus creating a Re2O9 double octahedron with a Re-R e distance of 2.92 Å.
Maternal nutrition modifies trophoblast giant cell phenotype and fetal growth in mice
Authors: Watkins Adam J , Lucas Emma S , Marfy-Smith Stephanie , Bates Nicola , Kimber Susan J , Fleming Tom P
Published: March 2015

Mammalian placentation is dependent upon the action of trophoblast cells at the time of implantation. Appropriate fetal growth, regulated by maternal nutrition and nutrient transport across the placenta, is a critical factor for adult offspring long-term health. We have demonstrated that a mouse maternal low-protein diet (LPD) fed exclusively during preimplantation development (Emb-LPD) increases offspring growth but programmes adult cardiovascular and metabolic disease. In this study, we investigate the impact of maternal nutrition on post-implantation trophoblast phenotype and fetal growth. Ectoplacental cone explants were isolated at day 8 of gestation from female mice fed either normal protein diet (NPD: 18% casein), LPD (9% casein) or Emb-LPD and culturedin vitro. We observed enhanced spreading and cell division within proliferative and secondary trophoblast giant cells (TGCs) emerging from explants isolated from LPD-fed females when compared with NPD and Emb-LPD explants after 24 and 48 h. Moreover, both LPD and Emb-LPD explants showed substantial expansion of TGC area during 24–48 h, not observed in NPD. No difference in invasive capacity was observed between treatments using Matrigel transwell migration assays. At day 17 of gestation, LPD- and Emb-LPD-fed conceptuses displayed smaller placentas and larger fetuses respectively, resulting in increased fetal:placental ratios in both groups compared with NPD conceptuses. Analysis of placental and yolk sac nutrient signalling within the mammalian target of rapamycin complex 1 pathway revealed similar levels of total and phosphorylated downstream targets across groups. These data demonstrate that early post-implantation embryos modify trophoblast phenotype to regulate fetal growth under conditions of poor maternal nutrition.
Condensin II Regulates Interphase Chromatin Organization Through the Mrg-Binding Motif of Cap-H2
Authors: Wallace Heather A , Klebba Joseph E , Kusch Thomas , Rogers Gregory C , Bosco Giovanni
Published: March 2015

The spatial organization of the genome within the eukaryotic nucleus is a dynamic process that plays a central role in cellular processes such as gene expression, DNA replication, and chromosome segregation. Condensins are conserved multi-subunit protein complexes that contribute to chromosome organization by regulating chromosome compaction and homolog pairing. Previous work in our laboratory has shown that the Cap-H2 subunit of condensin II physically and genetically interacts with the Drosophila homolog of human MORF4-related gene on chromosome 15 (MRG15). Like Cap-H2, Mrg15 is required for interphase chromosome compaction and homolog pairing. However, the mechanism by which Mrg15 and Cap-H2 cooperate to maintain interphase chromatin organization remains unclear. Here, we show that Cap-H2 localizes to interband regions on polytene chromosomes and co-localizes with Mrg15 at regions of active transcription across the genome. We show that co-localization of Cap-H2 on polytene chromosomes is partially dependent on Mrg15. We have identified a binding motif within Cap-H2 that is essential for its interaction with Mrg15, and have found that mutation of this motif results in loss of localization of Cap-H2 on polytene chromosomes and results in partial suppression of Cap-H2-mediated compaction and homolog unpairing. Our data are consistent with a model in which Mrg15 acts as a loading factor to facilitate Cap-H2 binding to chromatin and mediate changes in chromatin organization.
Chromatin Mediation of a Transcriptional Memory Effect in Yeast
Authors: Paul Emily , Tirosh Itay , Lai William , Buck Michael J , Palumbo Michael J , Morse Randall H
Published: March 2015

Previous studies have described a transcriptional “memory effect,” whereby transcript levels of many Abf1-regulated genes in the budding yeast Saccharomyces cerevisiae are undiminished even after Abf1 has dissociated from its regulatory sites. Here we provide additional support for this effect and investigate its molecular basis. We show that the effect is observed in a distinct abf1 ts mutant from that used in earlier studies, demonstrating that it is robust, and use chromatin immunoprecipitation to show that Abf1 association is decreased similarly from memory effect and transcriptionally responsive genes at the restrictive temperature. We also demonstrate that the association of TATA-binding protein and Pol II decreases after the loss of Abf1 binding for transcriptionally responsive genes but not for memory effect genes. Examination of genome-wide nucleosome occupancy data reveals that although transcriptionally responsive genes exhibit increased nucleosome occupancy in abf1 ts yeast, the promoter regions of memory effect targets show no change in abf1 ts mutants, maintaining an open chromatin conformation even after Abf1 eviction. This contrasting behavior reflects different inherent propensity for nucleosome formation between the two classes, driven by the presence of A/T-rich sequences upstream of the Abf1 site in memory effect gene promoters. These sequence-based differences show conservation in closely related fungi and also correlate with different gene expression noise, suggesting a physiological basis for greater access to “memory effect” promoter regions. Thus, our results establish a conserved mechanism underlying a transcriptional memory effect whereby sequences surrounding Abf1 binding sequences affect local nucleosome occupancy following loss of Abf1 binding. Furthermore, these findings demonstrate that sequence-based differences in the propensity for nucleosome occupancy can influence the transcriptional response of genes to an altered regulatory signal.
Diversity of Maize Shoot Apical Meristem Architecture and Its Relationship to Plant Morphology
Authors: Thompson Addie M , Yu Jianming , Timmermans Marja C P , Schnable Patrick , Crants James E , Scanlon Michael J , Muehlbauer Gary J
Published: March 2015

The shoot apical meristem contains a pool of undifferentiated stem cells and controls initiation of all aerial plant organs. In maize (Zea mays), leaves are formed throughout vegetative development; on transition to floral development, the shoot meristem forms the tassel. Due to the regulated balance between stem cell maintenance and organogenesis, the structure and morphology of the shoot meristem are constrained during vegetative development. Previous work identified loci controlling meristem architecture in a recombinant inbred line population. The study presented here expanded on this by investigating shoot apical meristem morphology across a diverse set of maize inbred lines. Crosses of these lines to common parents showed varying phenotypic expression in the F1, with some form of heterosis occasionally observed. An investigation of meristematic growth throughout vegetative development in diverse lines linked the timing of reproductive transition to flowering time. Phenotypic correlations of meristem morphology with adult plant traits showed an association between the meristem and flowering time, leaf shape, and yield traits, revealing links between the control and architecture of undifferentiated and differentiated plant organs. Finally, quantitative trait loci mapping was utilized to map the genetic architecture of these meristem traits in two divergent populations. Control of meristem architecture was mainly population-specific, with 15 total unique loci mapped across the two populations with only one locus identified in both populations.
Finding a Missing Gene: EFG1 Regulates Morphogenesis in Candida tropicalis
Authors: Mancera Eugenio , Porman Allison M , Cuomo Christina A , Bennett Richard J , Johnson Alexander D
Published: March 2015

Fungi from the genus Candida are common members of the human microbiota; however, they are also important opportunistic pathogens in immunocompromised hosts. Several morphological transitions have been linked to the ability of these fungi to occupy the different ecological niches in the human body. The transcription factor Efg1 from the APSES family plays a central role in the transcription circuits underlying several of these morphological changes. In Candida albicans, for example, Efg1 is a central regulator of filamentation, biofilm formation, and white-opaque switching, processes associated with survival in the human host. Orthologs of Efg1 are present throughout the Candida clade but, surprisingly, the genome sequence of Candida tropicalis failed to uncover a gene coding for Efg1. One possibility was that the paralog of Efg1, Efh1, had assumed the function of Efg1 in C. tropicalis. However, we show that this gene has only a minor role in the morphological transitions mentioned above. Instead, we report here that C. tropicalis does have an ortholog of the EFG1 gene found in other Candida species. The gene is located in a different genomic position than EFG1 in C. albicans, in a region that contains a gap in the current genome assembly of C. tropicalis. We show that the newly identified C. tropicalis EFG1 gene regulates filamentation, biofilm formation, and white-opaque switching. Our results highlight the conserved role of Efg1 in controlling morphogenesis in Candida species and remind us that published genome sequences are drafts that require continuous curation and careful scrutiny.
Comorbidity of Physical and Mental Disorders in the Neurodevelopmental Genomics Cohort Study
Authors: Merikangas Kathleen R. , Calkins Monica E. , Burstein Marcy , He Jian-Ping , Chiavacci Rosetta , Lateef Tarannum , Ruparel Kosha , Gur Ruben C. , Lehner Thomas , Hakonarson Hakon , Gur Raquel E.
Published: March 2015

OBJECTIVES:

To examine patterns of associations between a broad range of mental and physical conditions by using a large, systematically obtained pediatric registry.

METHODS:

The sample included 9014 youth ages 8 to 21 years (4349 males and 4665 females; 3585 aged <13 years, 3678 aged 13 to 18 years, and 1751 aged 19 to 21 years) from the Philadelphia Neurodevelopmental Cohort identified through pediatric clinics at the Children’s Hospital of Philadelphia health care network by the Center for Applied Genomics. Measures were as follows: physical condition based on electronic medical records and interview data on 42 physical conditions of 14 organ systems/specialties and mental disorders based on an abbreviated version of the structured Kiddie-Schedule for Affective Disorders and Schizophrenia psychiatric diagnostic interview.

RESULTS:

There was a direct association between the severity of the physical condition and most classes of mental disorders, as well as with functional impairment. Models adjusted for sociodemographic correlates, other physical and mental disorders, and false discovery and revealed broad patterns of associations between neurodevelopmental disorders with behavior disorders (odds ratio [OR]: 1.5; 95% confidence interval [CI]: 1.3–1.8; P < .004) and attention-deficit/hyperactivity disorder (OR: 3.1; 95% CI: 2.7–3.6; P < .0001), and neurologic/central nervous system conditions (OR: 1.3; 95% CI: 1.1–1.9; P < .05) with mood disorders and attention-deficit/hyperactivity disorder (OR: 1.3; 95% CI: 1.1–1.5; P < .001), and autoimmune/inflammatory conditions with mood disorders (OR: 1.4; 95% CI: 1.1–1.8, P < .05).

CONCLUSIONS:

Findings show the strong overlap between physical and mental conditions and their impact on severity and functional impairment in youth. Specific patterns of comorbidity have important implications for etiology. Prospective tracking of cross-disorder morbidity will be important to establish more effective mechanisms for prevention and intervention.
Diversity and Inclusion Training in Pediatric Departments
Authors: Mendoza Fernando S. , Walker Leslie R. , Stoll Barbara J. , Fuentes-Afflick Elena , St Geme Joseph W. , Cheng Tina L. , Gonzalez del Rey Javier A. , Harris Christopher E. , Rimsza Mary E. , Li Jie , Sectish Theodore C.
Published: March 2015

BACKGROUND AND OBJECTIVE:

The diversifying US population of children necessitates assessing the diversity of the pediatric academic workforce and its level of cultural competency training. Such data are essential for workforce and educational policies.

METHODS:

An 8-question survey was sent to 131 US pediatric chairs to assess plans for diversity, targeted groups, departmental diversity, diversity measures, perceived success in diversity, and presence and type of cultural competency training.

RESULTS:

In all, 49.6% of chairs responded, and three-quarters of them reported having a plan for diversity, which targeted racial; ethnic; gender; lesbian, gay, bisexual, and transgender; disabled; and social class groups. Of the residents, 75% were women, as compared with 54% of faculty and 26% of chairs. Racial and ethnic diversity was limited among trainees, faculty, and leaders; <10% of each group was African American, Hispanic, or Native American. Asian Americans were more common among trainees (15%–33%) but were less common in faculty and leadership positions (0%–14%). Lesbian, gay, bisexual, and transgender physicians were represented in some groups. Measures of diversity included the number of trainees and faculty, promotion success, climate assessments, and exit interviews. Overall, 69% of chairs reported being successful in diversity efforts. A total of 90% reported cultural competency training for trainees, and 74% reported training for faculty and staff. Training in cultural competency included linguistic training, primarily in Spanish.

CONCLUSIONS:

Pipeline issues for minorities are ongoing challenges. Pediatric leadership needs more representation of racial and ethnic minorities, women, and LGBT. Suggestions for workforce and educational policies are made.
Parent-Reported Outcomes of a Shared Decision-Making Portal in Asthma: A Practice-Based RCT
Authors: Fiks Alexander G. , Mayne Stephanie L. , Karavite Dean J. , Suh Andrew , O’Hara Ryan , Localio A. Russell , Ross Michelle , Grundmeier Robert W.
Published: March 2015

BACKGROUND:

Electronic health record (EHR)-linked patient portals are a promising approach to facilitate shared decision-making between families of children with chronic conditions and pediatricians. This study evaluated the feasibility, acceptability, and impact of MyAsthma, an EHR-linked patient portal supporting shared decision-making for pediatric asthma.

METHODS:

We conducted a 6-month randomized controlled trial of MyAsthma at 3 primary care practices. Families were randomized to MyAsthma, which tracks families’ asthma treatment concerns and goals, children’s asthma symptoms, medication side effects and adherence, and provides decision support, or to standard care. Outcomes included the feasibility and acceptability of MyAsthma for families, child health care utilization and asthma control, and the number of days of missed school (child) and work (parent). Descriptive statistics and longitudinal regression models assessed differences in outcomes between study arms.

RESULTS:

We enrolled 60 families, 30 in each study arm (mean age 8.3 years); 57% of parents in the intervention group used MyAsthma during at least 5 of the 6 study months. Parents of children with moderate to severe persistent asthma used the portal more than others; 92% were satisfied with MyAsthma. Parents reported that use improved their communication with the office, ability to manage asthma, and awareness of the importance of ongoing attention to treatment. Parents in the intervention group reported that children had a lower frequency of asthma flares and intervention parents missed fewer days of work due to asthma.

CONCLUSIONS:

Use of an EHR-linked asthma portal was feasible and acceptable to families and improved clinically meaningful outcomes.
Chronic Hepatitis E Resolved by Reduced Immunosuppression in Pediatric Kidney Transplant Patients
Authors: Bouts Antonia H.M. , Schriemer Pytrik J. , Zaaijer Hans L.
Published: March 2015

At present, transient asymptomatic hepatitis E virus (HEV) infection is common among healthy adults in Western Europe, as reported by blood transfusion services. In immune-suppressed patients HEV infection is often without clinical symptoms, but without therapeutic intervention it may become chronic and lead to cirrhosis. This report describes the course of chronic HEV infection after kidney transplantation in 2 children, who cleared the virus after reduction in immunosuppressive therapy. If aminotransferase levels continue to be moderately elevated after transplantation, HEV infection should be excluded.
Antidepressant Use During Pregnancy and Asthma in the Offspring
Authors: Liu Xiaoqin , Olsen Jørn , Pedersen Lars Henning , Agerbo Esben , Yuan Wei , Li Jiong
Published: March 2015

BACKGROUND AND OBJECTIVES:

It has been suggested that maternal depression during pregnancy is associated with asthma in the offspring, but the role of medical treatment of depression is not known. Our goal was to examine whether prenatal antidepressant use increases the risk of asthma in the offspring.

METHODS:

A cohort study was performed among all live singletons born in Denmark between 1996 and 2007. Mothers who had a diagnosis of depressive disorder and/or who used antidepressants 1 year before or during the index pregnancy were identified. Using a Cox proportional hazards regression model, we estimated the hazard ratio (HR) for asthma in the offspring after antidepressant use during pregnancy.

RESULTS:

Of the 733 685 children identified, 84 683 had a diagnosis of asthma. A total of 21 371 children were exposed to prenatal maternal depression (ie, a diagnosis of depressive disorder or use of antidepressants 1 year before or during pregnancy). Prenatal maternal depression was associated with childhood asthma (HR: 1.25 [95% confidence interval (CI): 1.20–1.30]). Overall, 8895 children were exposed to antidepressants in utero. Compared with children born to mothers with prenatal depression and no antidepressant use during pregnancy, the HR for asthma after any antidepressant use during pregnancy was 1.00 (95% CI: 0.93–1.08). HRs after use of selective serotonin reuptake inhibitors only, newer antidepressants only, and older antidepressants only were 0.95 (95% CI: 0.88–1.03), 1.11 (95% CI: 0.89–1.39), and 1.26 (95% CI: 1.02–1.55), respectively.

CONCLUSIONS:

Antidepressant use during pregnancy generally did not increase the risk of asthma. Only use of older antidepressants was associated with an increased risk of asthma.
A eficácia gerencial aferida pelo alcance das metas estabelecidas no sistema de recompensa e sua relação com o empowerment psicológico
Authors: Do Nascimento Sabrina , Beuren Ilse Maria
Published: March 2015

O estudo objetiva averiguar a eficácia gerencial aferida pelo alcance das metas estabelecidas no sistema de recompensa aos empregados e sua relação com o empowerment psicológico em uma empresa multinacional. A presença do empowerment psicológico se circunscreve nesta pesquisa nos quatro elementos do modelo de Spreitzer (1995): competência, impacto, autodeterminação e significado. Pesquisa descritiva com abordagem predominantemente qualitativa foi realizada em uma empresa de origem americana, estabelecida na região Sul do Brasil. Para a coleta dos dados, utilizaram-se dois tipos de instrumentos de pesquisa: a) um questionário adaptado de Spreitzer (1995), composto de 24 questões com escala likert de sete pontos, para identificar a percepção dos empregados da empresa sobre o empowerment psicológico; e b) três roteiros de entrevistas, aplicados, respectivamente, ao supervisor de recursos humanos, gerente financeiro-contábil e supervisor de importação e exportação, para aferir a eficácia gerencial nas dimensões (padrões de desempenho, comparação de pares e desempenho global) propostas por Spreitzer (1995). Os dados coletados por meio de questionário foram submetidos à análise estatística simples, média e desvio padrão; os coletados nos roteiros de entrevistas, à análise de conteúdo. Ainda, para apurar os indicadores de lucratividade e rentabilidade, coletaram-se dados nas demonstrações contábeis da empresa publicadas no site da Bolsa de Valores de Nova York (NYSE). Conclui-se, com base nos resultados da pesquisa, que o empowerment psicológico, segundo o modelo de Spreitzer (1995), está relacionado com a eficácia gerencial aferida pelo alcance das metas estabelecidas no sistema de recompensa aos empregados na empresa objeto de estudo.
Do Innovation and Cooperation Influence SMEs’ Competitiveness? Evidence From the Andalusian Metal-Mechanic Sector
Authors: Tamayo Juan A. , Romero José E. , Gamero Javier , Martínez-Román Juan A.
Published: March 2015

This study's main objective is to determine the influence of innovation and cooperation on the competitiveness of SMEs in the metal-mechanic sector of Andalusia (Spain). Using information obtained by interviewing managers of a sample of 80 firms, we proposed a model of structural equations based on the Partial Least Squares (PLS) technique. This model, which explained 37% of the variability of competitiveness, also allowed us to test hypotheses about the positive influence of quality management, knowledge, financial resources and cooperation on innovative outcomes. Along with the contrasted hypotheses, the most noteworthy finding was that cooperation does not significantly influence the innovative outcomes of firms in this sector.
Fruit and Vegetable Prices and Perceptions in Mercalaspalmas Wholesale Market
Authors: Rodriguez-Feijoo Santiago , Rodriguez-Caro Alejandro , Gonzalez-Correa Carlos
Published: March 2015

This paper studies the behavior of fruit and vegetable prices in a wholesale market. Its aims are: a) to examine price behavior and changes; and b) to identify statistically significant factors in the perception of prices and to quantify the effect of these factors on the market price. For this purpose, daily data were obtained on modal prices at the Mercalaspalmas wholesale market from 2006 until mid-2010. The results obtained show there is a similar degree of flexibility in price increases and decreases, and show the product to be the determinant element in setting prices. There was found to be a strong degree of price permanence, in the sense that changes take place slowly and following a lag. The following significant factors were identified in the perception of prices: the length of time a price has remained unchanged in the market; the period during which a product has been absent from the market; the quantities traded at a given price; and the index of market prices. However, the quantitative effect of this body of factors on the perceived price is very limited.
Caso empresarial: La estrategia de crecimiento de Comercializadora Inducascos S.A.
Authors: Velásquez-Montoya Marcela , Robledo-Ardila Cristina , Aristizabal-Uribe Esteban
Published: March 2015

Comercializadora Inducascos S.A. inició sus operaciones en 1998 en la ciudad de Medellín, Colombia, enfrentando dificultades de todo tipo, tales como escaso capital, infraestructura limitada y un número reducido de empleados. Además, su fundador habia enfrentado varias quiebras económicas. Esta comercializadora es ahora una empresa mediana para el sector local con un alto porcentaje de participación de mercado debido al volumen de cascos que fabrica y comercializa, a su amplio portafolio de productos y a su estructura comercial que le permiten atender todos los segmentos del mercado colombiano. El crecimiento de las ventas de motocicletas en Colombia, el boom de importaciones de motos chinas desde el 2005 y la evolución de la normativa concerniente al uso obligatorio del casco han contribuido a que los volúmenes de ventas de la empresa hayan crecido de manera exponencial desde su creación y a que exista una demanda constante del producto. Este caso describe la toma de decisiones del fundador Ramiro Agudelo, que se traduce en la estrategia de crecimiento e internacionalización de la empresa.
A fuzzy finite element algorithm based on response surface method for free vibration analysis of structure
Authors: Tuan Nguyen Hung , Huynh Le Xuan , Anh Pham Hoang
Published: March 2015

This paper introduces an improved response surface-based fuzzy finite element analysis of structural dynamics. The free vibration of structure is established using superposition method, so that fuzzy displacement responses can be presented as functions of fuzzy mode shapes and fuzzy natural frequencies. Instead of direct determination of these fuzzy quantities by modal analysis which will involve the calculation of the whole finite element model, the paper proposes a felicitous approach to design the response surface as surrogate model for the problem. In the design of the surrogate model, complete quadratic polynomials are selected with all fuzzy variables are transformed to standardized fuzzy variables. This methodology allows accurate determination of the fuzzy dynamic outputs, which is the major issue in response surface based techniques. The effectiveness of the proposed fuzzy finite element algorithm is illustrated through a numerical analysis of a linear two-storey shear frame structure.