bluuebunny/crossref_metadata_2025_split huggingface dataset:
Zur Elektronenstruktur hochsymmetrischer Verbindungen der f‐Elemente. 42 Ableitung und Simulation des Kristallfeld‐Aufspaltungsmusters von Tris(bis(trimethylsilyl)amido)ytterbium(III)
Authors: Jank Stefan , Reddmann Hauke , Apostolidis Christos , Amberger Hanns‐Dieter 
Published: February 2007

AbstractElectronic Structures of Highly Symmetrical Compounds of f Elements. 42 Derivation and Simulation of the Crystal Field Splitting Pattern of Tris(bis(trimethylsilyl)amido)ytterbium(III)Tris(bis(trimethylsilyl)amido)ytterbium(III), (Yb(btmsa)3 (1)) was grown as a single crystal of the size 6×2×2 mm. The unpolarized absorption and luminescence as well as the σ and π absorption spectra of this crystal were recorded at room and low temperatures. The observed polarization properties as well as identificational calculations allowed the separation of zero‐phonon‐ and phonon‐assisted transitions of comparable intensities. The thus derived crystal field splitting pattern could be simulated by fitting the free parameters of a phenomenological Hamiltonian. In order to assign the coupling vibrations, FIR/MIR‐ and unpolarized Raman spectra of 1 as well as polarized Raman spectra of Y(btmsa)3 (2) were recorded and compared with previously assigned ones of MeGa(btmsa)2 and H(btmsa).
Crystal Growth and Structure Refinement of K4Ge9
Authors: Ponou Simeon , Fässler Thomas F. 
Published: February 2007

AbstractDeep‐red moisture and air sensitive single crystals of K4Ge9 were obtained by reacting GeO2 and elemental Ge with metallic W and K at high temperature in a niobium ampoule. The crystal structure of the compound was determined by single crystal X‐ray diffraction experiments. K4Ge9 crystallizes in a polar space group R3c (No. 161), Z = 4 with a = 21.208(1) and c = 25.096(2) Å. The compound contains discrete Ge94− Wade's nido‐clusters which are packed according to a hierarchical atom‐to‐cluster replacement of the Cr3Si prototype and are separated by K+ cations. Two independent [Ge9]4− clusters A (at Cr positions) and B (at Si positions) are found with a ratio A:B = 3:1. The B‐type cluster satisfactorily represents orientational disorder around the three‐fold axis.
Crystal Structure Investigation of RE–Ni–Zn Ternary Compounds (RE = La, Ce, Tb)
Authors: Solokha P. , De Negri S. , Saccone A. , Pavlyuk V. , Tedenac J.‐C. 
Published: February 2007

AbstractThe RENiZn (RE = La, Tb), RE2Ni2Zn (RE = La, Ce, Tb) and La3Ni3Zn ternary compounds were synthesized by two methods: by heating in a resistance furnace evacuated quartz ampoules containing Al2O3‐crucibles with element pieces and by induction melting in sealed Ta crucibles with subsequent annealing at 400 °C. Scanning electron microscopy (SEM) coupled with energy dispersive X‐ray spectroscopy (EDXS) was used for examining microstructure and phase composition of some of the alloys. The crystal structures for all the investigated phases were solved or confirmed on single crystal data by applying the direct methods refined by a standard least square procedure: LaNiZn – str. type ZrNiAl, hexagonal, $P{\bar 6}{\rm 2}m$, hP9, a = 0.7285(1), c = 0.3938(1) nm, wR2 = 0.0534, 257 F2 values, 14 variables; a = 0.7044(1), c = 0.3782(1) nm, wR2 = 0.0447, 236 F2 values, 14 variables for TbNiZn; La2Ni2Zn – str. type Pr2Ni2Al, orthorhombic, Immm, oI10, a = 0.4381(1), b = 0.5459(1) c = 0.8605(2) nm, wR2 = 0.0824, 223 F2 values, 13 variables; a = 0.4365(1), b = 0.5430(1) c = 0.8279(2) nm, wR2 = 0.0635, 209 F2 values, 13 variables for Ce2Ni2Zn; a = 0.4209(1), b = 0.5366(1) c = 0.8165 (1) nm, wR2 = 0.0757, 200 F2 values, 13 variables for Tb2Ni2Zn; La3Ni3Zn – str. type Y3Co3Ga, orthorhombic, Cmcm, oS28, a = 0.4276(1), b = 1.0310(2) c = 1.3636(3) nm, wR2 = 0.0859, 579 F2 values, 26 variables. The structural peculiarities of these compounds and their relations are discussed.
Structures and Spectroscopy of some Adducts of Coinage Metal(I) Cyanides with ‘Tetrahedral’‐Unidentate‐N‐Bases
Authors: Bowmaker Graham A. , Pettinari Claudio , Skelton Brian W. , Somers Neil , Vigar Nicholas A. , White Allan H. 
Published: February 2007

AbstractCrystallization of copper(I) cyanide from piperidine (‘pip’) solution yields an adduct of CuCN : pip (3 : 4) ratio, as established by a single crystal X‐ray structure determination, which also shows the complex to have a single‐stranded ···Cu(CN)Cu(CN)···spine (C,N scrambled), one‐third of the copper atoms carrying a pair of pip ligands, the others only one. Crystallization of silver(I) cyanide from piperidine (‘pip’) or cyclohexylamine (‘CyNH2’) solutions yields adducts of the unusual AgX : unidentate‐N‐base (1 : 2) stoichiometry. The CyNH2 adduct is, unusually for cyanide complexes of this type, mononuclear with a trigonal planar silver atom, [(NC)Ag(H2NCy)2], the AgCN component lying along the intersection of two crystallographic mirror planes which bisect and relate the H2NCy ligands (Ag‐C, N 2.067(3), 2.335(2) Å; N‐Ag‐N, C 80·80(6), 139.60(4)°). In the pip adduct, the immediate silver atom environment is also three‐coordinate (Ag‐C; N, N 2.080(1); 2.288, 2.443(1) Å; N‐Ag‐N 88·34(4), N‐Ag‐C 144.47(4), 125.07(4), (Σ357.9°) perturbed toward two‐coordination, but the silver atom environment geometry is further perturbed from planarity by the parallel approach of an inversion‐related molecule (Ag···C′ 2.926(1) Å (Ag···Ag′ 3.1842(2)°) forming a loose, albeit still discrete, dimer. Key features in the IR spectra of the above compounds and of AgCN : pip (1 : 1) and CuCN : CyNH2 (2 : 3) are assigned and discussed in terms of the structures or of proposed structures in the case of the latter two adducts. The structure of [ClAg(pip)3], adventitiously obtained, is also described (Ag‐Cl 2.471(3); Ag‐N 2.147(13), 2.188(7) (x2) Å; Cl‐Ag‐N 96.1(3), 98.5(2), N‐Ag‐N 116.3(2) (x2), 122.1(3)°).
Earth Alkaline Tetrathiosquarates: Syntheses and Crystal Structures of MgC4S4 · 6 H2O and CaC4S4 · 4 H2O
Authors: Beck Johannes , Ben‐Amer Younis 
Published: February 2007

AbstractConcentrated aqueous solutions of magnesium chloride and calcium nitrate, respectively, allow on addition of the potassium salt of tetrathiosquarate, K2C4S4 · H2O, the isolation of the earth alkaline salts MgC4S4 · 6 H2O (1) and CaC4S4 · 4 H2O (2) as orange and red crystals. The crystal structure determinations (1: monoclinic, C2/c, a = 17.2280(7), b = 5.9185(2), c = 13.1480(4) Å, β = 104.730(3)°, Z = 4; 2: monoclinic, P21/m, a = 7.8515(3), b = 12.7705(5), c = 10.6010(4) Å, β = 93.228(2)°, Z = 4) show the presence of C4S42− ions with almost undistorted D4h symmetry having average C–C and C–S bond lengths of 1.451Å and 1.659Å for 1and 1.451Å and 1.655Å for 2. The structure of 1 contains discrete, octahedral [Mg(H2O)6]2+ complexes. Several O–H····O and O–H····S bridges with H····O and H····S distances of less than 2.50Å connect cations and anions. The structure of 2 is built of concatenated, edge‐sharing Ca(H2O)6S2 polyhedra. The Ca2+ ions have the coordination number eight, C4S42− act as a chelating ligands towards Ca2+ with Ca–S distances of 3.14Å. The infrared and Raman spectra show bands typical for the molecular building units of the two compounds.
Crystal Structure of the New Cobalt Tellurite Chloride Co5Te4O11Cl4
Authors: Becker Richard , Johnsson Mats , Berger Helmuth 
Published: February 2007

AbstractThe crystal structure of the new compound Co5Te4O11Cl4 is described. It crystallizes in the triclinic system, space group P‐1 with the unit cell parameters a = 822.26(8) pm, b = 1029.7(1) pm, c = 1031.1(1) pm, α = 110.80(1)°, β = 97.950(9)°, γ = 98.260(9)° and Z = 2. The structure is layered along the bc–plane and built by [CoO5Cl], [CoO4Cl2] and [CoO4Cl] polyhedra sandwiched by [TeO3E] and [TeO4E] polyhedra. The layers can be regarded as infinite molecules without any net charge and only weak van der Waals forces connect them to each other. The halides and the lone‐pair, E, of TeIV protrude from the layers.
Synthesis, Characterization, and Crystal Structure of the New Schiff‐Bases derived from 1,2,4‐Triazole and the Structure of [(PPh3)2Cu(AMTT)]NO3·EtOH (AMTT = 4‐Amino‐5‐methyl‐2H‐1,2,4‐triazole‐3(4H)‐thione)
Authors: Heshmatpour Felora , Ghassemzadeh Mitra , Semsarha Maryam , Neumüller Bernhard 
Published: February 2007

AbstractThe reactions of 4‐amino‐5‐methyl‐2H‐1,2,4‐triazole‐3(4H)‐thione (AMTT, L1) with 2‐thiophen carbaldehyde, salicylaldehyde and 2‐nitrobenzaldehyde in methanol led to the corresponding Schiff‐bases (L1a‐c). The reaction of L1 with [(PPh3)2Cu]NO3 in ethanol gave the ionic complex [(PPh3)2Cu(L1)]NO3·EtOH (2) All compounds were characterized by infrared spectroscopy, elemental analyses as well as by X‐ray diffraction studies. Crystal data for L1a at 20 °C: space group P21/n with a = 439.6(2), b = 2074.0(9), c = 1112.8(4) pm, β = 93.51(3)°, Z = 4, R1 = 0.0406, L1b at −80 °C: space group P21/n with a = 1268.9(2), b = 739.3(1), c = 1272.5(1) pm, β = 117.97(1)°, Z = 4, R1 = 0.0361, L1c at −80 °C: space group P21/n with a = 847.8(1), b = 1502.9(2), c = 981.5(2) pm, β = 110.34(1)°, Z = 4, R1 = 0.0376 and for 2 at −80 °C: space group $\rm P{\bar1}$ with a = 1247.8(1), b = 1270.3(1), c = 1387.5(1) pm, α = 84.32(1)°, β = 84.71(1)°, γ = 63.12(1)°, Z = 2, R1 = 0.0539.
Syntheses, Spectral, Thermal and Structural Characterization of 2‐Phenyl‐2‐(1‐hydroxyiminoethyl)‐1,2,3,4‐tetrahydroquinazoline and Its Novel Nickel(II) Complex
Authors: Çolak Alper Tolga , Taş Murat , İrez Gazi , Yeşilel Okan Zafer , Büyükgüngör Orhan 
Published: February 2007

AbstractThe 2‐phenyl‐2‐(1‐hydroxyiminoethyl)‐1,2,3,4‐tetrahydroquinazoline (HL) and its NiII complex have been prepared and characterized by spectral method (FT‐IR, NMR (13C and 1H), UV‐vis.), elemental analysis, magnetic susceptibility and thermal analysis (TG, DTA) techniques. The crystal structures of HL and NiII complex were also determined by the single crystal X‐ray diffraction. The HL and NiII complex crystallizes in the monoclinic and triclinic, space groups P21/c and $P{\bar 1}$, respectively. The complex was occurred by the elimination of 1 mole of 2‐aminobenzylamine from the 2 moles of the HL after the ring opening reaction by the NiII attack. Crystallographic study reveal that NiII atom has a square planer geometry being coordinated by four nitrogen atoms of HL. Two thermal processes of the HL and NiII complex can occur in TG and DTA curves.
Pseudohalogeno Complexes of Sterically Hindered Tripyrrinatopalladium (TrpyPd) Fragments
Authors: Bröring Martin , Prikhodovski Serguei , Brandt Carsten D. , Cónsul Tejero Esther 
Published: February 2007

AbstractEight new pseudohalogeno complexes of sterically hindered TrpyPd fragments 4–11 have been prepared by salt metathesis in one step from known trifluoroacetates TrpyPdOAcF 1–3, using sodium salts of N3, NCO, NCS, NCSe, dicyanamide (dca) and tricyanomethanide (tcm) anions. Despite the propensity of the co‐ligands to bind to two or more metal centres in a bridging coordination mode all new complexes have been shown by NMR spectroscopy to be essentially monomeric in solution. X‐ray diffraction studies performed on TrpyPdNCS(6), TrpyPddca(8), TrpyPddca(9), and TrpyPdtcm(10) revealed the presence of two different conformers in the solid state, one with a helically distorted Trpy backbone for 6 and 10, and one with an almost planar tripyrrole but a tetrahedral distortion of the PdII coordination, a so‐called pseudoplanar form, for 8 and 9. Interestingly the helical forms are also detected by unusual wavenumbers for the νCN stretching bands in their IR spectra. The reason for the occurrence of two different conformers in the solid state appears to be the crystal packing which depends mainly on the shape of the anionic co‐ligand and on the presense of alkyl groups on the TrpyPd fragment.
Elevated levels of nonesterified fatty acids in the myocardium of alloxan diabetic rats
Authors: Chattopadhyay Jyotiprakas , Thompson Ed W. , Schmid Harald H. O. 
Published: February 2007

AbstractMyocardial nonesterified fatty acids (NEFA) increase markedly within the first two days after the induction of insulin‐dependent diabetes mellitus in rats by intravenous injection of alloxan. After initial variability, NEFA levels in diabetic hearets remain constant at approximately 450 nmol/g tissue (16 nmol/gmmol lipid P), which is about three times higher than that in control hearts. Nonesterified linoleic acid is significantly increased in diabetic heart whereas both arachidonic and docosahexaenoic acids are decreased compared to controls.
Modification of phospholipid polar head group with monomethylethanolamine and dimethylethanolamine decreases cholesteryl ester and triacylglycerol synthesis in cultured human fibroblasts
Authors: Maziere Cecile , Auclair Martine , Mora Liliana , Maziere Jean‐Claude 
Published: February 2007

AbstractModification of the phospholipid polar head group was achieved by supplementation of the growth medium of cultured human fibroblasts with the choline analogues monomethylethanolamine (ME) or dimethylethanolamine (DE) at a concentration of 80–200 μg/mL for 48 hr. The maximum concentration of phosphatidylmonomethylethanolamine (PME) or phosphatidyldimethylethanolemine (PDE) reached without affecting the phospholipid/protein ratio was about 45% of total phospholipids. Incorporation of oleic acid into cholesteryl esters and triacylglycerols was markedly inhibited after supplementation with ME or DE, and accounted for 60% and 40% of controls, respectively, at 200 μg/mL, whereas incorporation into phospholipids was not affected. AcylCoA:cholesterol acyltransferase (ACAT) and diacylglycerol acyltransferase (DGAT) activities measured on cell‐free extracts appeared to be decreased also by phospholipid polar head group modification, whereas the overall phospholipid acyltransferase activity remained unchanged. The intracellular content of cholesteryl esters and triacylglycerols, determined by the isotopic equilibrium method with radioactive cholesterol and glycerol, was found to be diminished to 50–60% and 40–50% of controls, respectively, after supplementation with the choline analogues. The study showed that modification of the phospholipid polar head group affects the activity of membrane‐bound enzymes involved in the metabolism of neutral lipids.
Effect of dietary fat on the lipid composition and utilization of short‐chain fatty acids by rat colonocytes
Authors: Awad Atif B. , Ferger Sandra L. , Fink Carol S. 
Published: February 2007

AbstractThe objective of the present studies was to examine the effect of dietary fat on the lipid composition of rat colonocytes and their utilization of short‐chain fatty acids (SCFA). Rats were fed 14% beef fat, fish oil or safflower oil plus 2% corn oil in a semi‐synthetic base diet for 4 wk. Colonocytes were isolated and their lipid composition was examined. Feeding beef fat and fish oil resulted in an increase in monounsaturated fatty acids and a reduction in ω‐6 fatty acids. Feeding fish oil resulted in an enrichment with ω‐3 fatty acids. These was no dietary influence on the amount of either cholesterol or phospholipids of colonocytes. Fish oil feeding resulted in significant increase in colonocyte free fatty acids (FFA) as compared to other diets. Dietary fat was found to have no effect on SCFA utilization by colonocytes. Colonocytes were found to utilize SCFA in the order of butyrate ≥acetate ≥propionate. The presence of acetate and propionate in the medium had no effect on the rate of butyrate utilization.
Contrasting effects of water‐soluble and water‐insoluble dietary fibers on bile acid conjugation and taurine metabolism in the rat
Authors: Ide Takashi , Horii Masaharu , Yamamoto Tadashi , Kawashima Kenji 
Published: February 2007

AbstractThe effect of the type of dietary fiber on the bile acid and taurine metabolism was examined in rats. Diets containing 10% of various water‐soluble fibers (citrus pectin, konjak mannan, guar gum) as compared to a fiber‐free diet increased biliary excretion of total bile acids. In contrast, water‐insoluble dietary fibers (cellulose, corn bran, chitin; 10% in the diets) as well as cholestyramine (5% in the diet) considerably, decreased bile acid excretion. Water‐soluble dietary fibermediated increases in bile acid excretion were totally attributable to increases in glycine‐conjugates. Thus, these fibers greatly increased by the bile acid glycine‐to‐taurine ratio (G/T). Excretio of glycine conjugates decreased more than that of taurine conjugates in rats fed various water‐insoluble dietary fibers. As a results, G/T in rats fed water‐insoluble fibers was significantly lowered as compared to G/T in animals fed a fiber‐free diet. Cholestyramine did not affect the G/T ratio of bile acids. Fecal bile acid excretion and the activities of hepatic cholesterol 7α‐hydroxylase (EC 1.14.13.17) in rats fed various water‐soluble dietary fibers approximately doubled as compared to the respective values for rats fed a fiber‐free diet. Whereas cholestyramine greatly increased these parameters, water‐insoluble fibers did not significantly affect them. Various water‐soluble fibers decreased hepatic concentration and urinary excretion of taurine as well as the activity of hepatic cysteine dioxygenase (EC 1.13.11.20). In contrast, water‐insoluble fibers considerably increased hepatic taurine concentrations and enzyme activities. The parameters for taurine metabolism were unaffected by cholestyramine. It was suggested that the types of dietary fiber affected hepatic taurine synthesis and thus modified bile acid glycine/taurine ratios.
Effect of dietary fat on phospholipid class distribution and fatty acid composition in rat fat cell plasma membrane
Authors: Khuu Thi‐Dinh K. L. , Demarne Y. , Nicolas C. , Lhuillery C. 
Published: February 2007

AbstractThe effect of dietary fats on phospholipid class distribution and fatty acid composition was studied in rat fat cell plasma membrane. Three groups of male Wistar weanling rats were fed for 8 wk three diets differing in the amount and nature of the fats: 1.5% sunflower oil (low fat control; LFC), 10% sunflower oil (high fat, unsaturated; HFU), 1.5% sunflower oil+8.5% cocoa butter (high fat, saturated; HFS). Plasma membranes were prepared from epididymal adipocytes. The amount and type of dietary fat significantly altered membrane phospholipid distribution. Phospholipid content was lowered with HFU as compared to LFC or HFS diets, but no changes were observed for cholesterol. Phosphatidylinositol (PI) and phosphatidylserine (PS) were less affected by dietary changes than were other phospholipid classes. Major changes were detected for phosphatidylcholine (PC), phosphatidylethanolamine (PE) and sphingomyelin (SM) contents. No large changes in PC and PE fatty acid compositions were observed between the LFC and HFS groups, but the HFU diet induced several changes. Correlations with plasma membrane 5′‐nucleotidase activities are discussed.
Lipoprotein lipase as a new tool in steryl ester analysis
Authors: Fischer Christine , Höll Wolfgang 
Published: February 2007

AbstractA new method for the quantitative hydrolysis of steryl esters is described. Using lipoprotein lipase (triacylglycero‐protein acylhydrolase, EC 3.1.1.34), steryl esters are cleaved to yield free sterols and fatty acids. In comparison to alkaline hydrolysis, the method is more gentle, more accurate and less laborious. Quantification of the hydrolysis products was done with capillary gas chromatography. The practicability of the method is demonstrated for authentic steryl esters and steryl esters as they occur in needles of Scots pine (Pinus sylvestris L.).
Existence of cholinephosphotransferase in mitochondria and microsomes of liver and lung of guinea pig and rat
Authors: Ghosh Sukla , Mukherjee Shyamali , Das Salil K. 
Published: February 2007

AbstractWe reported earlier on the occurrence of cholinephosphotransferase in the mitochondria of guinea pig lung. In order to determine whether organ and/or species specificities exist in regard to the cholinephosphotransferase activity in mitochondria, we have compared the subcellular distribution of the enzyme in the liver and lungs of rats and guinea pigs. Even though the activity of the enzyme was higher in microsomes than it was in mitochondria, the mitochondrial activity was authentic in both tissues of both species. The authenticity of mitochondrial activity was established by marker enzyme studies and ultrastructural examination of mitochondrial preparations.
The Na+K+ATPase activity in cultured human fibroblasts with an elevated phospholipid triene: tetraene ratio
Authors: Karmiol Soverin , Bettger William J. 
Published: February 2007

AbstractHuman skin fibroblasts were cultured at low density for 11 days in MCDB 110, 0.4% fetal bovine serum, a mitogen mixture, and were supplemented with 18∶2n−6 or 18∶1n−9 as a fatty acid‐albumin complex. The cells cultured with the 18∶2n−6 supplement had a 20∶3n−9/20∶4n−6 ratio of 0.29±0.07; the 18∶1n−9 supplemented cells had a ratio of 1.51±0.27. There was less than 4% difference in total growth of the cell population under the two culture conditions. The cells supplemented with 18∶2n−9 had similar levels of protein/cell, K+/mg cell protein and functional Na+K+ATPase activity.
Isolation of a guanine‐malondialdehyde adduct from rat and human urine
Authors: Hadley M. , Draper H. H. 
Published: February 2007

AbstractA 1∶1 adduct of guanine with malondialdehyde (MDA) was isolated from rat and human urine. This compound was shown to be identical to a synthetic adduct prepared according to the procedure of Setoet al. (Bull. Chem. Soc. Jpn. 58, 3431–3435, 1985). The UV, NMR and other characteristics of the compound were consistent with the tricyclic pyrimidinopurine structure proposed by these investigators. Its endogenous origin is indicated by its presence in the urine of rats fed an MDA‐free diet, and by the observation that its excretion increased following iron or carbon tetrachloride administration. It may serve as a marker for nucleic acid modification caused by lipid peroxidationin vivo.
Biochemical and functional abnormalities in hypercholesterolemic rabbit platelets
Authors: Dalal K. B. , Ebbe S. , Mazoyer E. , Carpenter D. , Yee T. 
Published: February 2007

AbstractThis study was designed to elucidate changes in rabbit platelet lipids induced by a cholesterol rich diet and to explore the possible correlation of these lipid changes with platelet abnormalities. Pronounced biochemical alterations were observed when serum cholesterol levels of 700–1000 mg% were reached. Hypercholesterolemic (HC) platelets contained 37% more neutral lipids and 16% less phospholipids than the controls. Lysolecithin, cholesterol esters and phosphatidylinositol (PI) levels were increased in HC platelets, and the levels of phosphatidylcholine (PC) were decreased. The cholesterol/phospholipid molar ratio of lipidemic platelets increased from 0.55±0.011 to 0.89±0.016 (P<0.01) in eight weeks. HC platelets had 90% more arachidonic acid (AA) in the PI than normal platelets. No significant changes in AA of PC were observed.Platelet function was monitored by the uptake and release of [14C]serotonin in platelet rich plasma (PRP), using varying concentrations of collagen as an aggregating agent. The uptake of [14C]serotonin in HC and normal platelets ranged from 78–94%. The percent of [14C]serotonin released from normal and HC platelets was proportional to the concentration of collagen. However, lipidemic platelets were hyperreactive to low concentrations of collagen. Incorporation of 50 μM acetylsalicylic acid into the aggregating medium suppressed the release of [14C]serotonin in normal PRP by more than 90%, but had only a partial effect on lipidemic PRP.