bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulating Enzyme‐Catalyzed Reactions
Authors: Bowman Anna , Mulholland Adrian
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Formation of Units for Wittig Reactions
Authors: Sauca Sorin‐Nicolae , Irimia Marinela
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
2‐Chlorodeoxyadenosine (Cladribine): Rational Development of a Novel Chemotherapeutic Agent
Authors: Cottam Howard B. , Carson Dennis A.
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Solid Lipid Nanoparticles for Targeted Brain Drug Delivery
Authors: Blasi Paolo , Giovagnoli Stefano , Schoubben Aurelie , Ricci Maurizio , Rossi Carlo
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Stability of Lipid Excipients in Solid Lipid Nanoparticles
Authors: Radomska‐Soukharev Anna
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Polymerization Reactions
Authors: Fink Gerhard , Brintzinger Hans‐Herbert
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Bestatin: Three Decades of Synthetic Strategies
Authors: Feske Brent D.
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Phosphopeptides: Chemical Synthesis, Analysis, Outlook and Limitations
Authors: Toth G. K. , Kele Z. , Varadi G.
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of Chiral Heterocyclic Phosphines for Application in Asymmetric Catalysis
Authors: Holz J. , Gensow M.‐N. , Zayas O. , Boerner A.
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
The Chemistry of Phosphinic and Phosphinous Acid Derivatives Containing the t‐Butyl Group as a Single Bulky Substituent: Synthetic, Mechanistic and Stereochemical Aspects
Authors: Drabowicz Jozef , Kudelska Wieslawa , Lopusinski Andrzej , Zajac Adrian
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Progress in the Synthesis of New Acetylcholinesterase Reactivators During the Period 1990—2004
Authors: Musilek K. , Kuca K. , Jun D. , Dolezal M.
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Do We Understand the Volatility of Ionic Liquids?
Authors: Ludwig Ralf , Kragl Udo
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
The Diverse Roles of Flavin Coenzymes — Nature′s Most Versatile Thespians
Authors: Mansoorabadi Steven , Thibodeaux Christopher J. , Liu Hung‐wen
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
The Fatty Acid Factory of Yeasts
Authors: Kolter Thomas
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Centenary of the Award of a Nobel Prize to Eduard Buchner, the Father of Biochemistry in a Test Tube and Thus of Experimental Molecular Bioscience
Authors: Jaenicke Lothar
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Photochemical DNA Manipulation and DNA Analysis by Photoresponsive Artificial DNA
Authors: Fujimoto Kenzo
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Molecular Mechanism of Learning and Memory Based on the Research for Ca2+/Calmodulin‐Dependent Protein Kinase II
Authors: Yamauchi Takashi
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Molecular Mechanism of Neuroprotective Drugs Against Oxidative Stress‐Induced Neuronal Cell Death
Authors: Hara Hirokazu
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Application of the Human Hepatoblastoma Cell Lines Inducibly Expressing Peroxisome Proliferator‐Activated Receptors (PPARs)
Authors: Tachibana Keisuke
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Natural Product Hybrids
Authors: Gademann Karl
Published: November 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
New Examples of Metal Coordination Architectures of 4,4′‐Sulfonyldibenzoic Acid: Syntheses, Crystal Structure and Luminescence
Authors: Chen Xiao‐Li , Gou Lei , Hu Huai‐Ming , Fu Feng , Han Zhong‐Xi , Shu Hui‐Ming , Yang Meng‐Lin , Xue Gang‐Lin , Du Chuan‐Qin
Published: November 2007

Seven metal–organic coordination polymers, namely [Cd(sfdb)(phen)2]n·2nH2O (1), [Cd(sfdb)(bpy)2]n·nH2O (2), [Cu(sfdb)(phen)(H2O)]n·0.5nH2O (3), [Zn(sfdb)(bpy)(H2O)]n·0.5nCH3OH (4), [Cd(sfdb)(quin)]n (5), [Cd3(sfdb)2(Hsfdb)2(phen)2]n (6), and [Cd(sfdb)(bpy)]n (7) [H2sfdb = 4,4′‐sulfonyldibenzoic acid, phen = 1,10‐phenanthroline, quin = 2,2′‐biquinoline, bpy = 2,2′‐bipyridine] have been synthesized according to the principles of crystal engineering and structurally characterized by elemental analysis, IR spectroscopy, and single‐crystal X‐ray diffraction analyses. Compounds 1–3 form 1D zigzag chains. Two phen ligands chelate to one cadmium atom in 1, which is rare in similar polymers, while two 2,2′‐bpy ligands coordinate one cadmium atom in 2. The zigzag chains in 3 propagate in two different directions (rotated by 75°) that are assembled by supramolecular forces into an intriguing three‐dimensional network. Complexes 4 and 5 form square‐wave‐like 1D chains, although the results indicate a transformation of 2,2′‐bpy into quin during the course of the hydrothermal synthesis of compound 5. Compound 6 is a 1D grid‐chain based on a linear trinuclear unit, and compound 7 shows a 1D double chain containing 28‐membered rings with sfdb2– ligands as bridges. Weak hydrogen bonding and intra‐ and/or intermolecular π···π stacking contacts in compounds 3–7 link the discrete 1D chains into high‐dimensional supramolecular structures. The sfdb2– ligand displays multiple coordination modes in these seven complexes. Complexes 1, 2, and 4–7 show blue photoluminescence at room temperature. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Proton and Deuteron Exchange in TTB‐Like Na1.2Nb1.2W0.8O6: Structural Characterization and Spectroscopic Study
Authors: Sanjuán M. Luisa , Kuhn Alois , Azcondo M. Teresa , García‐Alvarado Flaviano
Published: November 2007

Proton‐ and deuteron‐exchange reactions have been performed on Na1.2Nb1.2W0.8O6 with the tetragonal tungsten bronze (TTB) structure. Na+/H+ and Na+/D+ ion exchange occurs when aqueous nitric acid solutions are used as the exchanging agent. Up to two out of the three Na+ ions are readily exchanged to yield crystalline powder samples. The ion‐exchange reaction proceeds topotactically, in other words the basic TTB structure is retained, although X‐ray and electron diffraction reveal that the exchange process produces an orthorhombic supercell which possesses a true unit cell based on a ≈ 2√2aTTB, b ≈ √2aTTB, c = 2TTB. The nature of the hydrogenated species has been analyzed by means of IR and Raman spectroscopy on both parent and exchanged compounds. The results are interpreted in terms of short M–O (M = Nb or W) bonds formed through the trapping of two protons or deuterons close to the oxygen ions of the [MO6] octahedra. The band assigned to the short M–O bonds disappears after deprotonation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis, Photophysical Characterization, and Surface Photovoltage Spectra of Windmill‐Shaped Phthalocyanine–Porphyrin Heterodimers and Heteropentamers
Authors: Zhao Zhixin , Poon Chun‐Ting , Wong Wai‐Kwok , Wong Wai‐Yeung , Tam Hoi‐Lam , Cheah Kok‐Wai , Xie Tengfeng , Wang Dejun
Published: November 2007

The synthesis and characterization of three nonperipherally substituted, covalently‐linked phthalocyanine–porphyrin hybrid molecules is described. The optical and photophysical properties of these compounds are studied in detail. The intramolecular energy transfer process is investigated and quantified in terms of the quantum yield of the energy transfer and is found to be highly effective in these molecules. The photophysical properties of the phthalocyanine core of these three compounds are significantly modified by the presence of the porphyrin moieties. These molecules display interesting optical‐power‐limiting behavior and a surface photovoltaic effect. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
ortho‐Directed Metathetical Fluoride/Amide Exchange in (Pentafluorophenyl)amides
Authors: Shutov Pavel L. , Karlov Sergey S. , Harms Klaus , Zabalov Maxim V. , Sundermeyer Jörg , Lorberth Jörg , Zaitseva Galina S.
Published: November 2007

The indium tris(amide)s [(Et2N)3–nIn{N(C6F5)(2‐C5H4N)}n] [n = 1 (15), 2 (16) or 3 (9)] have been prepared by treatment of [In(NEt2)3]2 (3) with a stoichiometric amount of (2‐C5H4N)(C6F5)NH (1). The analogous reaction of Bi(NMe2)3 (2) with 3 equiv. of amine 1 and the treatment of BiCl3 (5) with a stoichiometric amount of (2‐C5H4N)(C6F5)NLi (4) both lead to [Bi{N(C6F5)(2‐C5H4N)}3] (10). In contrast, only the difluoride 11 or the monofluoride 12, which are the products of intramolecular ortho‐directed exchange of NMe2 and F substituents, are obtained from the reaction of 2 with 1 or 2 equiv. of 1, respectively. The reaction between Me3Sb(Hal)2 [Hal = Br (7) Cl, (8)] and 1 or 2 equiv. of lithium salt 4 gives the corresponding stable monoamides [Me3(Hal)Sb{N(C6F5)(2‐C5H4N)}] [Hal = Br (17), Cl (18)] or bis(amide) [Me3Sb{N(C6F5)(2‐C5H4N)}2] (19), respectively. The structure of 9 has been confirmed by an X‐ray structure analysis, and density functional calculations data have been used to explain the possible reaction pathway of the ortho‐directed metathetical fluoride/amide exchange.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Synthesis, Crystal Structure and Thermal Properties of Phosphorylated Cyclotriphosphazenes
Authors: Lejeune Nicolas , Dez Isabelle , Jaffrès Paul‐Alain , Lohier Jean‐Fançois , Madec Pierre‐Jean , Sopkova‐de Oliveira Santos Jana
Published: November 2007

A convergent approach for the incorporation of arylphosphonate moieties into the cyclotriphosphazene unit is described. The synthesis is based on the reaction of hexachlorocyclotriphosphazene with diethyl 4‐hydroxyphenylphosphonate in the presence of anhydrous potassium carbonate. This reaction is characterised by substitution of the chloride atoms, which thus produces the hexaarylphosphono derivative in good yield. The product of this reaction is fully characterised, including a single X‐ray diffraction study. The hydrolysis of the hexaphosphonate compound to its hexaphosphonic acid analogue is reported. All products were characterised by NMR and IR spectroscopy and mass spectrometry. The thermal stability and degradation behaviour of these new compounds were investigated by thermogravimetric analysis.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis, X‐ray Crystal Structures and Electrochemistry of (Indenyl)ruthenium Complexes Containing dppf and Heterocyclic Thiolato/Thione Ligands
Authors: Ng Sin Yee , Leong Weng Kee , Goh Lai Yoong , Webster Richard D.
Published: November 2007

A number of (indenyl)ruthenium complexes containing dppf [1,1′‐bis(diphenylphosphanyl)ferrocene] and heterocyclic thiolato/thione ligands have been synthesized. All the complexes were fully characterized by microanalytical and spectroscopic techniques, together with X‐ray diffraction analyses for those containing the benzothiazolato (thiolato) and the thiadiazole (thione) ligands. Cyclic voltammetry (CV) experiments indicated that these complexes can be oxidized in three one‐electron processes at positive potentials. Differences in chemical reversibility observed during variable‐temperature CV experiments indicated that it was likely that the oxidation processes occurred at two electronically noncommunicating sites within the molecules. One site could be assigned as the oxidation of the Ru ion (two one‐electron processes), whilst the second site was assigned as the oxidation of the dppf (one one‐electron process). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Zeolite‐Encapsulated Copper(II) Complexes of Pyridoxal‐Based Tetradentate Ligands for the Oxidation of Styrene, Cyclohexene and Methyl Phenyl Sulfide
Authors: Maurya Mannar R. , Singh Baljit , Adão Pedro , Avecilla Fernando , Costa Pessoa João
Published: November 2007

Interaction of copper(II)‐exchanged zeolite‐Y with N,N′‐ethylenebis(pyridoxyliminato) (H2pydx‐en, I) and N,N′‐propylenebis(pyridoxyliminato) (H2pydx‐1,3‐pn, II) ligands in refluxing methanol leads to the formation of the corresponding complexes, abbreviated herein as [Cu(pydx‐en)]‐Y (3) and [Cu(pydx‐1,3‐pn)]‐Y (4), in the supercages of zeolite‐Y. The neat complexes, [Cu(pydx‐en)] (1) and [Cu(pydx‐1,3‐pn)] (2), have also been prepared with these ligands. Spectroscopic studies (IR, UV/Vis and EPR), elemental analyses, thermal studies, field emission scanning electron micrographs (FE‐SEM) and X‐ray diffraction patterns have been used to characterise these complexes. The crystal and molecular structures of 1 and of 2·CH3OH, have been determined, confirming the ONNO binding mode of the ligands. The geometry around the metal ion is very slightly distorted square‐planar in 1 and distorted square‐pyramidal in 2. The encapsulated complexes catalyse the oxidation, by H2O2 and tert‐butyl hydroperoxide, of styrene, cyclohexene and thioanisole efficiently. Under optimised reaction conditions, the oxidation of styrene catalysed by 3 and 4 gave 23.6 % and 28.0 % conversion, respectively, using tert‐butyl hydroperoxide as oxidant, where styrene oxide, benzaldehyde, benzoic acid and phenylacetaldehyde are the major products. Better conversions have been obtained using H2O2 as oxidant. Oxidation of cyclohexene catalysed by these complexes gave cyclohexene oxide, 2‐cyclohexen‐1‐ol, cyclohexane‐1,2‐diol and 2‐cyclohexen‐1‐one as the major products. A maximum of 90.1 % conversion of cyclohexene with 3 and 83.0 % with 4 was obtained under optimised conditions. Similarly, a maximum of 80.3 % conversion of methyl phenyl sulfide with 3 and 81.0 % with 4 was observed, where the selectivity of the major product methyl phenyl sulfoxide was found to be about 60 %. Tests for the recyclability and heterogeneity of the reactions have also been carried out, and the results indicate their recyclability. A possible reaction mechanism has been proposed by titrating a methanol solution of 1 and 2 with H2O2 to identify the possible intermediates.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
C–C Coupling Reaction of Triphenylbismuth(V) Derivatives and Olefins in the Presence of Palladium Nanoparticles Immobilized in Spherical Polyelectrolyte Brushes
Authors: Malysheva Yulia B. , Gushchin Alexey V. , Mei Yu , Lu Yan , Ballauff Matthias , Proch Sebastian , Kempe Rhett
Published: November 2007

Carbon–carbon coupling reactions were carried out by using the triphenylbismuth(V) derivatives Ph3BiX2 (X = O2CH, O2CMe, O2CEt, O2CnPr, O2CnBu, O2CtBu, O2CPh, O2CCH2Cl, O2CCCl3, O2CCF3) and a variety of olefins in the presence of palladium nanoparticles immobilized in spherical polyelectrolyte brushes (Pd@SPB) under mild conditions (50 °C). The effects of the organobismuth derivatives and the unsaturated compounds and the influence of the ratio of solvents (THF and water) on the yield of cross‐coupled products were studied. The most active organobismuth compound studied was triphenylbismuth bis(trifluoroacetate), Ph3Bi(O2CCF3)2. This system, which is based on the use oforganobismuth compounds, allows the formation of Heck‐type products without the addition of base. Time‐dependent product and side‐product formation is indicative of a variety of fast (relative to product formation) organobismuth decomposition pathways that lower the overall yield of the coupling reactions. In comparison to homogeneous catalyst systems used for this type of C–C coupling reaction, we only used a very low Pd loading. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Toward Carbohydrate Derivatives with a Markedly Acidic Centre: Structures and Reactions of Selenium(IV) Diolates
Authors: Klüfers Peter , Reichvilser Moritz M.
Published: November 2007

Cyclic selenites, of the general formula (DiolH–2)SeO, derived from the diols ethane‐1,2‐diol, propane‐1,2‐diol, cis‐cyclopentane‐1,2‐diol, cis‐cyclohexane‐1,2‐diol, trans‐cyclohexane‐1,2‐diol, 1,1′‐bicyclopentyl‐1,1′‐diol, 1,1′‐bicyclohexyl‐1,1′‐diol, propane‐1,3‐diol, 2,2‐dimethylpropane‐1,3‐diol, 1,1‐bis(hydroxymethyl)cyclopropane, 1,1‐bis(hydroxymethyl)cyclopentane, 1,4‐anhydroerythritol and the methyl glycosides of β‐D‐ribofuranose, β‐D‐ribopyranose, α‐D‐mannopyranose, β‐D‐xylopyranose have been prepared and characterised by multinuclear NMR spectroscopy and single‐crystal X‐ray diffraction. Even with the polyfunctional sugar derivatives, oxidation of substrates did not occur. It has been demonstrated that the title compounds are hydrolytically stable at low pH values. Experimental NMR spectroscopy and structural data are consistent with results of density functional calculations and bonding has been analysed by means of natural bond orbital (NBO) theory.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Formation and Characterization of Platinum and Palladium Complexes of Bis(trimethylsilylmethyl)tellane
Authors: Vigo Ludmila , Oilunkaniemi Raija , Laitinen Risto S.
Published: November 2007

The mononuclear (telluroether)platinum and ‐palladium complexes cis‐[PtCl2{Te(CH2SiMe3)2}2] (2c), trans‐[PtCl2{Te(CH2SiMe3)2}2] (2t), and trans‐[PdCl2{Te(CH2SiMe3)2}2] (3t) have been prepared from bis(trimethylsilylmethyl)tellane and bis(benzonitrile)dichloridoplatinum and ‐palladium and structurally characterized by single‐crystal X‐ray diffraction and NMR spectroscopy. The isomer distribution of the platinum complex depends on the initial molar ratio of the reactants. When [PtCl2(NCPh)2] was used in excess, 2c was the main product. Upon increasing the initial ligand/metal molar ratio, the relative amount of 2t increased. The stoichiometric reaction afforded approximately equal amounts of the cis and trans isomers. Further increase of the initial amount of the ligand yielded 2t. The mononuclear palladium complex was the trans isomer 3t, regardless of the initial molar ratio of the reactants. Small amounts of the dinuclear complex [Pt2Cl4{μ‐Te(CH2SiMe3)2}{Te(CH2SiMe3)2}2] (4) were also formed, when the initial ligand/metal molar ratio was low. Compound 4 shows a rare bridging telluroether ligand and two different platinum coordination environments, one exhibiting a cis‐Cl/cis‐TeR2 arrangement and the other a trans‐Cl/trans‐TeR2 arrangement. In case of palladium, the equimolar reaction afforded [Pd2(μ‐Cl)2Cl2{Te(CH2SiMe3)2}2] (5) in good yields. As the relative amount of the ligand was increased, also 3t was formed. When the ligand/metal ratio was >2:1, 3t was the only product. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Optical, Magnetic and Structural Properties of the Spin‐Crossover Complex [Fe(btr)2(NCS)2]·H2O in the Light‐Induced and Thermally Quenched Metastable States
Authors: Legrand Vincent , Pillet Sébastien , Carbonera Chiara , Souhassou Mohamed , Létard Jean‐François , Guionneau Philippe , Lecomte Claude
Published: November 2007

[Fe(btr)2(NCS)2]·H2O [btr = 4,4′‐bis(1,2,4‐triazole)] is thearchetype of highly cooperative and low‐dimensional spin‐crossover complexes, which exhibit low‐spin (LS) to high‐spin (HS) light‐induced conversion at very low temperature. The structural reorganizations related to the light‐induced and thermally induced LS–HS transitions were characterized by single‐crystal X‐ray diffraction below the relaxation temperature (T = 15 K < TLIESST) and at 130 K within the thermal hysteresis loop. We show that the LIESST and thermal spin transitions lead to the same structural variations, namely an elongation of the Fe–N bonds by 0.18 Å (Fe–NNCS) and 0.20 Å (Fe–Nbtr), on going from LS to HS, together with a reorientation of the NCS group by nearly 13°. The atomic displacement amplitudes, derived from the crystal structures, indicate lattice vibration modes of larger amplitudes and correlatively lower vibration frequencies in the HS state. The deformation of the crystal lattice as a function of temperature and laser excitation was quantitatively analyzed in terms of the HS and LS thermal‐expansion (αHS and αLS) and spin‐transition spontaneous‐strain (ϵ) tensors. The eigendirections and eigenvalues of the α and ϵ tensors correlate well with the weak and strong interactions in the solid and are responsible for the high cooperativity and low‐dimensional behaviour. Magnetic and spectroscopic measurements were performed in all the different spin states and related to the structural findings. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Heterocycle‐Substituted Indenes as Precursors for Supported Zirconocene Catalysts
Authors: Aragón Sáez Pedro J. , Carrillo‐Hermosilla Fernando , Villaseñor Elena , Otero Antonio , Antiñolo Antonio , Rodríguez Ana M.
Published: November 2007

The indene ligands {1‐C9H7R} [R = C2H4(C4H7O2) (1), C2H4(C3H5O2) (2), CH2(C5H9O) (3)] were prepared by alkylation of indene and used to prepare the SiMe2‐bridged indenylcyclopentadiene ligands {Me2Si(3‐C9H6R)(C5Me4H)}[R = C2H4(C4H7O2) (4), CH2(C5H9O) (5)]. Bis(indenyl)‐and ansa‐indenylcyclopentadienyl zirconocenes [Zr{1‐η5‐C9H6R}2Cl2] {R = C2H4(C4H7O2) (6), C2H4(C3H5O2) (7), CH2(C5H9O) (8)} and [Zr{Me2Si(3‐η5‐C9H5R)(η5‐C5Me4)}Cl2] {R = C2H4(C4H7O2) (9), CH2(C5H9O) (10)} were prepared by the reaction of ZrCl4 with the appropriate mono‐ or dilithium salts of 1–5. The molecular structure of [Zr{Me2Si(3‐η5‐C9H5C2H4(C4H7O2))(η5‐C5Me4)}Cl2] (9) was determined by single‐crystal X‐ray diffraction studies. Indenylzirconium complexes 6–10 were immobilized on thf‐modified MgCl2, and these supported systems were used to polymerize ethylene in the presence of methylaluminoxane. The catalytic activity of these complexes in both homogeneous and supported polymerization reactions is discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
The First Linear Coordination Oligomer Linked by 4,4′‐Bipyridine
Authors: Wang Yutian , Englert Ulli
Published: November 2007

A unique coordination oligomer derived from bridging 4,4′‐bipyridine (bipy) ligands was synthesized and characterized. Long linear [Ag4(bipy)5]4+ tetracations, shorter [Ag2(bipy)3]2+ dications and 4‐aminobenzoate anions represent the major constituents. When silver nitrate was added to solutions of this salt, polymerization in high yield occurred. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
(η5‐Cyclopentadienyl)(η4‐tetrasila‐ and η4‐trisilagermacyclobutadiene)cobalt: Sandwich Complexes Featuring Heavy Cyclobutadiene Ligands
Authors: Takanashi Kazunori , Lee Vladimir Ya. , Ichinohe Masaaki , Sekiguchi Akira
Published: November 2007

(η5‐Cyclopentadienyl)(η4‐tetrasilacyclobutadiene)cobalt{[(η4‐R4Si4)CoCp], 2} and (η5‐cyclopentadienyl)(η4‐trisilagermacyclobutadiene)cobalt {[(η4‐R4Si3Ge)CoCp], 4} (R = SiMetBu2) were synthesized by reaction of the dipotassium salts of tetrasilacyclobutadiene dianion K+2·[R4Si4]2– (1) and trisilagermacyclobutadiene dianion K+2·[R4Si3Ge]2– (3) with [CpCoI2(PPh3)]. Alternatively, 4 was prepared by the reaction of 3 with [Cp2Co]+·[PF6]–. X‐ray crystallographic analysis of 2 confirmed its sandwich‐type structure, manifesting a nearly square‐planar Si4 ring and diagnostic perhaptocoordination of both ligands, η4‐tetrasilacyclobutadiene and η5‐cyclopentadienyl, to the Co atom. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Reconstruction of shape and its effect on flow in arterial conduits
Authors: Gambaruto A. M. , Peiró J. , Doorly Denis J. , Radaelli A. G.
Published: November 2007

The geometry of arterial conduits derived fromin vivoimage data is subject to acquisition and reconstruction errors. This results in a degree of uncertainty in defining the bounding geometry for a patient‐specific anatomical conduit. In applying computational fluid dynamics to model the flow in specific anatomical configurations, the effect of the uncertainty in boundary definition should be considered, particularly if the objective is to extract quantitative measures of the local haemodynamics.

Taking an example of a bypass graft configuration, we examine the effects of image threshold, surface smoothing and semi‐idealization on the modelled geometry and the resulting flow. Procedures for reconstruction from medical images are outlined and applied with different parameter values within the image uncertainty range to create alternative models from the same data set.

Methods to characterize the flow structure and wall shear stress (WSS) are introduced and used to provide quantitative comparison of the different haemodynamic environments associated with the varying model geometries. Comparable effects on the WSS distribution are found to occur with progressively increased surface smoothing and semi‐idealization of the geometry by elliptical section fitting. Significant differences in WSS correspond to different threshold choices. Copyright © 2007 John Wiley & Sons, Ltd.
Geological evolution and structural style of the Palaeozoic Tafilalt sub‐basin, eastern Anti‐Atlas (Morocco, North Africa)
Authors: Toto E. A. , Kaabouben F. , Zouhri L. , Belarbi M. , Benammi M. , Hafid M. , Boutib L.
Published: November 2007

The Tafilalt is one of a number of generally unexplored sub‐basins in the eastern Anti‐Atlas of Morocco, all of which probably underwent a similar tectono‐stratigraphic evolution during the Palaeozoic Era. Analysis of over 1000 km of 2‐D seismic reflection profiles, with the interpretation of ten regional seismic sections and five isopach and isobath maps, suggests a multi‐phase deformation history for the Palaeozoic‐aged Tafilalt sub‐basins. Extensional phases were probably initiated in the Cambrian, followed by uniform thermal subsidence up to at least the end of the Silurian. Major extension and subsidence did not begin prior to Middle/Upper Devonian times. Extensional movements on the major faults bounding the basin to the north and to the south took place in synchronisation with Upper Devonian sedimentation, which provides the thickest part of the sedimentary sequence in the basin. The onset of the compressional phase in Carboniferous times is indicated by reflectors in the Carboniferous sequence progressively onlapping onto the Upper Devonian sequence. This period of compression developed folds and faults in the Upper Palaeozoic‐aged strata, producing a structural style characteristic of thin‐skinned fold and thrust belts. The Late Palaeozoic units are detached over a regional décollement with a northward tectonic vergence. The folds have been formed by the process of fault‐propagation folding related to the thrust imbricates that ramp up‐section from the décollement. Copyright © 2007 John Wiley & Sons, Ltd.
Impact of inflammatory bowel disease and ursodeoxycholic acid therapy on small-duct primary sclerosing cholangitis
Authors: Charatcharoenwitthaya Phunchai , Angulo Paul , Enders Felicity B. , Lindor Keith D.
Published: November 2007

A longitudinal, cohort study was performed to characterize the clinical features of patients with small-duct primary sclerosing cholangitis (PSC) occurring with and without inflammatory bowel disease (IBD) and to determine the influence of IBD and the effect of ursodeoxycholic acid (UDCA) therapy on the course of the liver disease. Forty-two patients with small-duct PSC (14 women and 28 men; mean age, 36.7 ± 13.3 years) were followed for up to 24.9 years. At presentation, prevalence of signs of liver disease (none versus 35%,

P

= 0.002), gastroesophageal varices (5% versus 30%,

P

= 0.03), and stage III/IV disease (9% versus 45%,

P

= 0.008) were lower in those with IBD versus those without IBD. During follow-up, 6 patients underwent liver transplantation, and another died of cirrhosis. Using the Cox proportional hazard analysis, concomitant IBD was not associated with liver death or transplant, whereas the revised Mayo risk score for PSC was the only prognostic factor associated with liver-related outcomes (relative risk, 6.47; 95% confidence interval, 1.75-137.5). UDCA (13-15 mg/kg/day) therapy for an average of 40 months showed biochemical improvement (

P

< 0.001) in UDCA-treated patients, while no significant change occurred in untreated patients. UDCA therapy had no effect on delaying progression of disease (relative risk, 0.95; 95% confidence interval, 0.38-2.36).

Conclusion:

Small-duct PSC often is recognized at an early stage in patients with IBD; however, IBD has no impact on long-term prognosis. Although UDCA therapy improves liver biochemistries, it may not delay disease progression during the short period of treatment. (Hepatology 2008.)
Ultrastructure of Trypanosoma cruzi revisited by atomic force microscopy
Authors: Rocha Gustavo Miranda , Miranda Kildare , Weissmüller Gilberto , Bisch Paulo Mascarello , de Souza Wanderley
Published: November 2007

Most advances in atomic force microscopy (AFM) have been accomplished in recent years. Previous attempts to use AFM to analyze the organization of pathogenic protozoa did not significantly contribute with new structural information. In this work, we introduce a new perspective to the study of the ultrastructure of the epimastigote form of Trypanosoma cruzi by AFM. Images were compared with those obtained using field emission scanning electron microscopy of critical point dried cells and transmission electron microscopy of negative stained detergent‐extracted and air‐dried cells. AFM images of epimastigote forms showed a flagellum furrow separating the axoneme from the paraflagellar rod (PFR) present from the emergence of the flagellar pocket to the tip of the flagellum. At high magnification, a row of periodically organized structures, which probably correspond to the link between the axoneme, the PFR and the flagellar membrane were seen along the furrow. In the origin of the flagellum, two basal bodies were identified. Beyond the basal bodies, small periodically arranged protrusions, positioned at 400 nm from the flagellar basis were seen. This structure was formed by nine substructures distributed around the flagellar circumference and may correspond to the flagellar necklace. Altogether, our results demonstrate the importance of the application of AFM in the structural characterization of the surface components and cytoskeleton on protozoan parasites. Microsc. Res. Tech., 2008. © 2007 Wiley‐Liss, Inc.
Mapping the intake of different elements in vegetal tissues by dual‐energy X‐ray imaging at DaΦne synchrotron light source
Authors: Reale L. , Kaiser J. , Reale A. , Lai A. , Flora F. , Balerna A. , Cinque G. , Fanelli M. , Ruggieri F. , Faenov A. , Pikuz T. , Tucci A. , Poma A. , Zuppella P. , Liška M. , Malina R.
Published: November 2007

This article reports on the first utilization of the soft X‐ray beamline at the DaΦne synchrotron light source for mapping the intake of different elements in plant tissues. As a test, the method of dual‐energy X‐ray microradiography was applied to the investigation of the natural sulfur content in dried leaf and root samples. Our ultimate goal was to monitor the pollutant lead and its intake, which was added in controlled doses to the hydroponic medium of laboratory‐controlled samples of vegetal species. The results obtained by the nondestructive X‐ray radiographic analysis are compared to the values of concentrations determined by a standard chemical analysis utilizing atomic absorption spectroscopy. From this comparison the validity of the X‐ray detection of heavy metals in biological samples has been confirmed. The superposition of the dual energy results on the simple planar radiography shows the representation of the pollutant intake directly on the sample structures. It should be pointed out that this method, developed here for plant root and leaves could be applied to any biological sample of interest, but the preparation and observation conditions necessitate different strategies according to the type of sample under analysis. Microsc. Res. Tech., 2008. © 2007 Wiley‐Liss, Inc.
Post‐embryonic development of the antennal sensilla inMelipona quadrifasciata anthidioides(Hymenoptera: Meliponini)
Authors: Azevedo Dihego de Oliveira , Matiello‐Guss Cirlei Pereira , Rönnau Milton , Zanuncio José Cola , Serrão José Eduardo
Published: November 2007

The sensilla are sensory organs formed by cuticular and cellular structures specialized in reception of chemical and physical stimuli from the environment and transmission to the insect's central nervous system. In function of the great concentration of sensilla, the antennae are the main organs for interaction between bees and with the environment. This work studied the presence of antennal sensilla in the different phases of pupal development of the stingless beeMelipona quadrifasciata anthidioidesby means of scanning electron microscopy and light microscopy. The results showed that antennal sensilla begin their development in the transition of the prepupae to the white‐eyed pupae and finish it in the pigmented‐body pupae phase. The antennal sensilla were exposed to the environment in the black‐eyed pupae when the old cuticle is completely digested, suggesting that only in the final pupal phases can these bees perceive the environmental stimuli. Microsc. Res. Tech., 2008. © 2007 Wiley‐Liss, Inc.
Ultrastructural study on the body surface of the acanthocephalan parasite Dentitruncus truttae in brown trout
Authors: Dezfuli Bahram S. , Lui Alice , Giari Luisa , Boldrini Paola , Giovinazzo Giancarlo
Published: November 2007

Scanning electron microscope (SEM) investigations on the holdfast elements, proboscis hooks, and trunk spines of Dentitruncus truttae (Acanthocephala, Palaeacanthocephala), an endoparasite of Salmo trutta (brown trout), provide more data about the surface of these taxonomic relevant structures. In both acanthocephalan sexes, the fully everted cylindrical proboscis possessed 18 longitudinal rows of hooks with 18 hooks per row (rarely 19–20). Hook length varied according to position on the proboscis; apical hooks were 40–52 μm long, middle hooks were 31.7–36.6 μm, and basal hooks were 38.1–40 μm. Starting from the anterior end of the metasoma, numerous cuticular spines (26.7–30 μm in length) were visible and their number progressively decreased posteriorly. SEM observations of D. truttae hooks and spines revealed the presence of many surface striations on each proboscis hook. These surface striations were absent from trunk spines. From the base of the hook, the striations ran parallel toward the point of convergence. Additionally, survey of longitudinal and transversal sections of the hook using transmission electron microscope confirmed that the hook surface was not smooth. SEM comparison with the hooks of several palaeacanthocephalan species, as well as with the hooks of species belonging to Eoacanthocephala and Polyacanthocephala, indicated that the striations are currently exclusive to D. truttae proboscis hooks. Microsc. Res. Tech., 2008. © 2007 Wiley‐Liss, Inc.
A morphometric analysis of tunnel valleys in the eastern North Sea based on 3D seismic data
Authors: Kristensen Thomas B. , Huuse Mads , Piotrowski Jan A. , Clausen Ole R.
Published: November 2007

A 1250 km2 3D seismic volume is used to provide a detailed spatial and geometrical analysis of fifteen Pleistocene tunnel valleys in the Danish North Sea. All the valleys are buried; they are up to 39 km long, 3–4 km wide and up to 350 m deep. The valleys are part of a vast tunnel valley province covering an area of some 0.5 million km2 of the formerly glaciated lowland areas of North West Europe. The valleys consist of non‐branching, non‐anastomosing troughs; they exhibit strongly undulating bottom profiles with numerous sub‐basins and thresholds, and are characterised by adverse end slopes. Cross‐cutting relationships and theoretical considerations suggest the occurrence of seven major episodes of valley incision attributed to ice marginal oscillations within a few glacials. Calculations considering the valley end gradients and theoretical ice‐surface profiles suggest that the valleys were formed by pressurised subglacial meltwater erosion. Given a range of theoretical ice‐surface profiles, the adverse end slopes are well beyond the supercooling threshold, which suggests that the water was not in thermal equilibrium with the basal ice and that flow was concentrated in substantial conduits with sufficient mass and flux to maintain water temperature well above the freezing point. Copyright © 2007 John Wiley & Sons, Ltd.
Effects of particle size reduction of insoluble fibres by micron technology on various caecal and faecal indices
Authors: Huang Ya‐Ling , Sheu Fuu , Lee Mao‐Hsiang , Chau Chi‐Fai
Published: November 2007

BACKGROUND: Previous findings demonstrated that particle size reduction of insoluble fibre materials (i.e. starfruit insoluble fibre‐rich fraction and cellulose) to micro‐sizes effectively enhanced their physicochemical properties, which provided clues to their physiological functions. The aim of the present study was to investigate the effects of particle size reduction of these insoluble fibres by micron technology on indices of bowel health.

RESULTS: Feeding of the micronised fibres (9.68–14.3 µm), especially those prepared by high‐pressure micronisation, effectively (P < 0.05) improved various caecal and faecal indices, such as decreasing the caecal ammonia concentration (by 20.0–30.0%), increasing the faecal output (135–150%) and moisture content (143–157%) and lowering the activities of undesired β‐D‐glucosidase (by 39.2–43.6%) and β‐D‐glucuronidase (by 71.4–77.5%) in faeces of hamsters. Relationships between physicochemical properties and physiological functions of the micronised fibres were considered. The results also demonstrated that the type, processing and related particle size of insoluble fibres were important factors affecting their physicochemical properties and physiological functions.

CONCLUSION: The consumption of micronised insoluble fibres at 5% level might exert a favourable effect on improving various caecal and faecal indices. The results of this study provide some hints on potential applications of micron technology in the food industry. Copyright © 2007 Society of Chemical Industry
Effect of O2 scavenger on the shelf‐life of catfish (Pangasius sutchi) steaks during chilled storage
Authors: Mohan Chitradurga O , Ravishankar Chandragiri N , Srinivasagopal Teralandur K
Published: November 2007

BACKGROUND: Active packaging for preserving meat products, including seafoods, has been gaining importance in recent times. The present study was undertaken to assess the effectiveness of O2 scavenger, the most widely used active packaging technology, on the shelf‐life of catfish steaks in chilled storage conditions.

RESULTS: O2 scavenger was effective in reducing the oxygen concentration inside the packaging to as low as 0.42% within 24 h. This reduction in oxygen in O2 scavenger packages showed positive effects on quality parameters compared to control air packs. Total volatile base nitrogen (TVB‐N), thiobarbituric acid value and peroxide value of catfish steaks packed in O2 scavenger was significantly different (P < 0.05) compared to air‐packed samples. Based on the sensory, microbiological and TVB‐N values, the control samples were acceptable only up to 10 days, compared to 20 days in O2 scavenger‐packed samples, extending the shelf‐life by 10 days.

CONCLUSION:O2 scavenger reduced the oxygen concentration inside the package significantly within 24 h compared to control air packs. By using this technique, the use of a vacuum packing machine can be avoided. Further, O2 scavenger extended the product's shelf‐life up to 20 days, compared to 10 days in control packs. Copyright © 2007 Society of Chemical Industry
Influence of a severe reduction of the feeding level during the period immediately prior to free‐range fattening on performance and fat quality in Iberian pigs
Authors: Daza Argimiro , Lopez‐Bote Clemente J , Olivares Alvaro , Menoyo David , Ruiz Jorge
Published: November 2007

BACKGROUND: Restricted feeding before fattening is a common procedure in the production of Iberian pigs, but little scientific information about its consequences on productive traits and characteristics of fat is available. This work studied the effect of a severe feeding restriction previous to the free‐range fattening on carcass and fat quality traits in Iberian pigs, considering two different feeding levels (high restriction: HR; versus maintenance level: M) before free‐range fattening.

RESULTS: Animals from the M group showed longer and higher‐perimeter hams and tended (P < 0.10) to show higher slaughter and carcass weights, carcass inner length and loin and sirloin weights than HR ones. Animals from the HR group showed lower proportions of total saturated fatty acids (SFA) and higher total monounsaturated fatty acids in the backfat inner layer than those from the M group. Total polyunsaturated fatty acids in intramuscular neutral lipids were higher in HR pigs than in M ones, while stearic acid (C18:0) was lower. The average daily gain, fatty acid profile of the outer backfat layer and that of the hepatic polar and neutral lipids and the rheological features of backfat inner layer remained unaffected.

CONCLUSION: A severe reduction of the feeding level previous to free‐range fattening does not produce compensatory growth, tends to diminish carcass quality and to slightly increase IMF content and improves the fatty acid profile of the inner backfat layer. Copyright © 2007 Society of Chemical Industry
Effect of carbohydrate supplementation provided through drinking water during feed withdrawal on meat and liver colours in broilers
Authors: Karacay Numan , Ocak Nuh , Sarica Musa , Erener Guray
Published: November 2007

BACKGROUND:The effect of saccarose supplementation provided through drinking water during feed withdrawal on meat and liver colour was investigated in a total of 50 broilers (five floor pens with 10 broilers) at 43 days. Treatments consisted of: (1) full‐fed control broilers fed the standard broiler diet and water for the full 10 h (control); (2) fasted broilers receiving only water (FW); (3) 1 g (0.01SW); (4) 2 g (0.02SW); and (5) 3 g (0.03SW) saccarose L−1 supplemented water for the 10 h. The CIE colour values representing lightness (L*), redness (a*), and yellowness (b*) were measured on raw livers, breast and thigh meats.

RESULTS:Full‐fed broilers had lower dressing percentage, higher abdominal fat and liver yield and lighter thigh meat coloration than the FW birds (P < 0.05). The 0.02SW and 0.03SW resulted in live shrinks that were lower (P < 0.05) than those found in FW broilers. The 0.02SW and 0.03SW resulted in liver colours that were lighter than those found in FW and 0.01SW birds but darker than from control birds (P < 0.05).

CONCLUSION:It was concluded that saccarose supplementation during feed withdrawal appears to have a measurable impact on live shrink, and lightness of liver and thigh meat colour in broilers. Copyright © 2007 Society of Chemical Industry
Broccoli (Brassica oleraceavar. botrytis L.) improves the survival and up‐regulates endogenous antioxidant enzymes inDrosophila melanogasterchallenged with reactive oxygen species
Authors: Li Yuk Man , Chan Ho Yin Edwin , Huang Yu , Chen Zhen Yu
Published: November 2007

BACKGROUND:The fruit fly (Drosophila melanogaster) is commonly used as an ageing model. It is unknown if commonly consumed vegetables can affect the survival of fruit fly. The present study was to investigate effect of broccoli, cabbage, Chinese cabbage and carrot on the survival time ofDrosophila melanogaster, when the flies were challenged with superoxide anion (paraquat) and hydrogen peroxide.

RESULTS:The paraquat and hydrogen peroxide survival tests found that broccoli extracts (BE) was most effective in prolonging the mean survival time compared with the control and other three vegetable extracts. The prolongation of survival time by BE was dose‐dependent in range of 1–50 mg mL−1diet. Supplementation of BE reduced not only total body lipid hydroperoxide level (LPO) but also increased the activity of copper‐zinc containing superoxide dismutase (CuZnSOD), manganese containing SOD (MnSOD) and catalase. RT‐PCR analysis indicated that the increase in enzymatic activities of SOD and catalase was mediated by up‐regulation of genes for CuZnSOD, MnSOD and catalase.

CONCLUSION:The free‐radical scavenging activity of BE inDrosophila melanogasterwas mediated, at least in part, by up‐regulation of endogenous antioxidant enzymes at both the transcriptional and translational level. Copyright © 2007 Society of Chemical Industry