bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hair analysis–a biological marker for passive smoking in pregnancy and childhood
Authors: Klein J , Koren G 
Published: April 2003

Passive smoking has been shown to adversely affect the health of infants and children. We used hair analysis for nicotine and its metabolite cotinine as a biological marker for exposure to smoking in these two groups. Using radioimmunoassay we measured maternal and fetal hair concentrations of nicotine and cotinine in the motherinfant pairs belonging to three different groups based on the mother' smoking habits. The three groups were: active smokers, passive smokers and nonsmokers. There was a significant correlation between maternal and neonatal hair concentration for both, nicotine and cotinine. Mothers and infants in the smoking groups, both active and passive, had significantly higher hair concentrations of both, nicotine and cotinine than in the control, nonsmoking group. In an older cohort, we compared two groups: 78 asthmatic children were compared to 86 healthy children exposed to similar degrees of passive smoking. By using objective, biological markers, our study aimed at verifying whether asthmatic children are different from nonasthmatic children in the way their bodies handle nicotine. Our results show, that, despite the fact that parents of asthmatic children tend to smoke a lower number of cigarettes per day, their children had an average twofold higher concentrations of cotinine in their hair then the control, nonasthmatic children. These studies document the importance of hair analysis as a tool for measuring exposure to cigarette smoke.
Karyomegaly of tubular cells as early stage marker of the nephrotoxicity induced by ochratoxin A in rats
Authors: Maaroufi K , Zakhama A , Baudrimont I , Achour A , Abid S , Ellouz F , Dhouib S , Creppy E E , Bacha H 
Published: April 2003

Cases of karyomegaly were described by Sclare30 and by Mihatch31 in patients affected with tubular-interstitial nephropathy. The Karyomegalic cells showed enlarged nuclei with accumulation of genetic material. No aetiology was suggested. Our study of rats experimentally intoxicated by ochratoxin A, a well-known nephrotoxic compound, indicates the presence of karyomegaly with alteration of the tubular tissue. In control animals no karyomegalic cells were detected. These observations suggest that karyomegaly with megacytosis may be caused by the nephrotoxic ochratoxin A in the kidney. In addition abnormal mitosis together with karyomegalic cells were observed at an earlier stage of the intoxication (30 days) suggesting possible regeneration if the OTA insults are stopped. After 90 days of treatment, the degeneration increased and only karyomegalic and apoptotic-like cells were observed indicating that the regeneration no longer occurs and that the degeneration becomes irreversible.
Synthesis, Structure, and Phosphine-Induced Degradation of a Ruthenapentaborane Cluster with a Sterically Demanding Hexamethylbenzene Ligand
Authors: Kawano Yasuro , Kawakami Hiroyuki , Shimoi Mamoru 
Published: April 2003

Abstract
The reaction of [(η6-C6Me6)RuCl2]2 with excess BH3·THF produced a ruthenaborane cluster, arachno-[(η6-C6Me6)RuB4H10] (1). Compound 1 underwent cluster degradation through the action of Pme3 to afford arachno-[(η6-C6Me6)Ru(Pme3)B3H7] (2).
Cleavage of 2-Methoxyethoxymethyl Ethers Catalyzed by Cerium(IV) Ammonium Nitrate (CAN) in Acetic Anhydride
Authors: Tanemura Kiyoshi , Suzuki Tsuneo , Nishida Yoko , Satsumabayashi Koko , Horaguchi Takaaki 
Published: April 2003

Abstract
The reactions of 2-methoxyethoxymethyl (MEM) ethers 1 with a catalytic amount of cerium(IV) ammonium nitrate (CAN) in acetic anhydride gave the corresponding mixed acetal esters 2 and acetates 3.
A Solution Route to Synthesize Nickel Thiospinels
Authors: Shimizu Youichi , Yano Tomoyasu 
Published: April 2003

Abstract
Ni3S4, CoNi2S4, and NiCo2S4 thiospinels were synthesized by a pH-controlled homogeneous precipitation method at 70 °C with metal-chlorides and thioacetamide in the ammonium chloride–ammonia buffer solutions adjusted to pH = 9.9.
Hydrothermal Soft Chemical Synthesis of Ni(OH)2–Birnessite Sandwich Layered Compound and Layered LiNi1/3Mn2/3O2
Authors: Feng Qi , Xu Yaohua , Kajiyoshi Koji , Yanagisawa Kazumichi 
Published: April 2003

Abstract
A layered lithium nickel manganese oxide, Li1Ni1/3Mn2/3O2, has been hydrothermally prepared from a sandwich nickel manganese hydroxide–oxide precursor, Ni7Mn14O27(OH)10·nH2O, which has been hydrothermally synthesized at 200 °C by intercalating Ni(OH)2 into layered birnessite. In this precursor, MnO2 layer and Ni(OH)2 layer alternately pack together to form sandwich-like layered structure. The compounds were characterized by XRD and IR spectrum.
Reaction of Stable Silylene–Isocyanide Complexes with Boranes: Synthesis and Properties of the First Stable Silylborane–Isocyanide Complexes
Authors: Takeda Nobuhiro , Kajiwara Takashi , Tokitoh Norihiro 
Published: April 2003

Abstract
Stable silylene–isocyanide complexes [Tbt(Mes)SiCNAr (Ar = Tbt, Mes*; Tbt = 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl; Mes = mesityl; Mes* = 2,4,6-tri-t-butylphenyl)] reacted with BH3·THF to give the first stable silylborane–isocyanide complexes [Tbt(Mes)SiHBH2CNAr]. The thermal equilibrium between Tbt(Mes)SiHBH2CNAr and TbtSiH2BH(Mes)CNAr was observed.
Palladium-Catalyzed Benzylic C–H Borylation of Alkylbenzenes with Bis(pinacolato)diboron or Pinacolborane
Authors: Ishiyama Tatsuo , Ishida Kousaku , Takagi Jun , Miyaura Norio 
Published: April 2003

Abstract
Borylation at the benzylic C–H bond of alkylbenzenes with bis(pinacolato)diboron [(Me4C2O2)B–B(O2C2Me4)] or pinacolborane [(Me4C2O2)B–H] was carried out at 100 °C in the presence of a catalytic amount of 10% Pd/C. The reaction selectively afforded pinacol benzylboronates in good yields directly from various alkylbenzenes.
Unusual Metal-Dependent Acceleration and Deceleration in the Metal-Catalyzed Hydrosilylation of Olefin Using Pyridyldimethylsilanes
Authors: Itami Kenichiro , Mitsudo Koichi , Nishino Akira , Yoshida Jun-ichi 
Published: April 2003

Abstract
The Rh- and Pt-catalyzed hydrosilylations of olefin utilizing 2-pyridyl-, 3-pyridyl-, 4-pyridyl-, and phenyldimethylsilane are described. Whereas huge rate acceleration was observed with 2-PyMe2SiH in the Rh-catalyzed reaction, huge rate deceleration was observed with 2-PyMe2SiH and 4-PyMe2SiH in the Pt-catalyzed reaction.
Effects of Salt, Acid and Base on the Decomposition of 2-Chlorophenol in Supercritical Water
Authors: Lee Geun-hee , Nunoura Teppei , Matsumura Yukihiko , Yamamoto Kazuo 
Published: April 2003

Abstract
The effect of salt, acid and base as additives on the decomposition of 2-chlorophenol (2CP) in supercritical water was investigated. Four additives were selected, NaCl as a salt, HCl and H2SO4 as acids, and KOH as a base. The addition of salts and acids had a little effect on the decomposition of 2CP in supercritical water (SCW), but that of bases showed a significant effect to enhance the decomposition rate.
Lower Rim 1,3-Disubstituted Derivatives of Calix[4]arene Amides Having Amino Acid Ester and Amines as Pendants
Authors: Rao P V , Rao C P , Kolehmainen E , Wegelius E K , Rissanen K 
Published: April 2003

Abstract
Lower rim modification of calix[4]arene at its 1,3-alternate positions to result in the molecules of potential importance possessing amide bonds and other functional moieties as generated from the reaction between calix[4]arene-1,3-diacid and the amino acids and/or substituted amines was carried out and the structural properties of the products were addressed.
A Novel Reaction Pathway in Olefin-Deuterium Exchange Reaction inside the Micropores of Rh(II) Dicarboxylate Polymer Complexes
Authors: Naito Shuichi , Tanibe Tomonori , Saito Emiko , Miyao Toshihiro , Mori Wasuke 
Published: April 2003

Abstract
Three dimensional microporous polymers of Rh fumarate or Rh terephthalate complexes exhibited high catalytic activity for hydrogen exchange and hydrogenation of olefins at 200 K. The hydrogen exchange reaction takes place only inside the nanopores of the complexes without complete scission of C–H bond of olefin molecule.
Ab Initio Studies on the Relative Stabilities of Neutral and Ionic Forms of Acetic Acid–Methylamine Complex and β-Alanine in Various Solvents
Authors: Hwang Sungu , Jang Yun Hee , Chung Doo Soo 
Published: April 2003

Abstract
The preference between neutral and ionic forms of acetic acid–methylamine complex and β-alanine in solution was studied quantum mechanically. The solvents studied were water, methanol, CH2Cl2, and hexane, representing various polarities.
A Novel Heat-Resist Silicone Polymeric Material with Refractive Index Controllability
Authors: Yasuda Naoki , Yamamoto Shigeyuki , Wada Yuji , Yanagida Shozo 
Published: April 2003

Abstract
A novel heat-resist optical waveguide silicone copolymer was successfully developed, with refractive index controllability between 1.558 and 1.523 by partially changing the substituent in the side chain, and high transparency in the visible and near-infrared region, 0.6–1.7 µm.
Synthesis, Structure, and Reactions of the First Stable Aromatic S-Nitrosothiol Bearing a Novel Dendrimer-Type Steric Protection Group
Authors: Goto Kei , Hino Yoko , Takahashi Yusuke , Kawashima Takayuki , Yamamoto Gaku , Takagi Nozomi , Nagase Shigeru 
Published: April 2003

Abstract
A stable aromatic S-nitrosothiol was synthesized by taking advantage of a novel dendrimer-type steric protection group, and its structure was determined by X-ray crystallographic analysis. Its reactions including oxidation to a stable S-nitrothiol are described.
Boron–Metal Exchange Reaction of Silylboranes with Organometallic Reagents: A New Route to Arylsilyl Anions
Authors: Kawachi Atsushi , Minamimoto Takashi , Tamao Kohei 
Published: April 2003

Abstract
The boron–metal exchange reaction of (arylsilyl)boranes with alkyllithiums, potassium tert-butoxide, and methylmagnesium bromide affords the corresponding silyllithium, silylpotassium, and silylmagnesium compounds, respectively. Especially, the boron–lithium exchange reaction occurs even in hydrocarbon solvents such as toluene and hexane as well as in THF.
Can Cp2Zr(C2H4) Easily React with Hydrosilane? Theoretical Study
Authors: Sakaki Shigeyoshi , Takayama Tatsunori , Sugimoto Manabu 
Published: April 2003

Abstract
DFT calculations clearly show that a zirconocene–ethylene complex, Cp2Zr(C2H4), easily reacts with hydrosilane, SiH4, to afford either Cp2Zr(H)(C2H4SiH3) or Cp2Zr(SiH3)(C2H5). In the transition state, the Si–H anti-bonding σ*-orbital of SiH4 overlaps well with the π-back donating molecular orbital between Zr dπ and C2H4 π* orbitals.
A Dimeric Mixed-Anions Lead(II) Complex: Synthesis and Structural Characterization of [Pb2(BTZ)4(NO3)(H2O)](ClO4)3 {BTZ = 4,4′-Bithiazole}
Authors: Mahjoub Ali Reza , Morsali Ali 
Published: April 2003

Abstract
The reaction of mixture Pb(ClO4)2 and Pb(NO3)2 with 4,4′-bithiazole ligand yielded white crystals of [Pb2(C6H4N2S2)4(NO3)(H2O)](ClO4)3. In this complex the cationic part is in fact binuclear and contains two PbL2 groups linked via bridging NO3− anion. It also contains a water molecule and as well as 4,4′-bithiazole ligands in all cases are coordinated via nitrogen atoms. Three perchlorate anions are uncoordinated to lead(II) and the lone pair of valence electrons of the lead(II) ions appears to be stereochemically active. The coordinated water molecule is involved in hydrogen bonding acting as hydrogen-bond donors with two O atoms of perchlorate ions as potential hydrogen-bond acceptors.
Resonance Raman Spectroscopic Detection of Pyridylazo Complex Formed at Liquid–Liquid Interface in Centrifugal Liquid Membrane System
Authors: Ohashi Akira , Watarai Hitoshi 
Published: April 2003

Abstract
A new method of resonance Raman microprobe spectroscopy combined with a centrifugal liquid membrane (CLM) method was constructed and successfully applied to the detection of the complex of palladium(II) with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) formed at the heptane/water interface. The depth profiles of resonance Raman intensities of Pd(II)–5-Br-PADAP complex along the axis perpendicular to the interface confirmed that the complex existed only at the liquid–liquid interface.
Thermal and Pressure Induced Spin Crossover of a Novel Iron(III) Complex with a Tripodal Ligand Involving Three Imidazole Groups
Authors: Sunatsuki Yukinari , Sakata Masafumi , Matsuzaki Susumu , Matsumoto Naohide , Kojima Masaaki 
Published: April 2003

Abstract
A novel spin crossover Fe(III) complex, [Fe(H3L)](ClO4)3·(4-fim)·H2O (H3L = tris[2-(((imidazol-4-yl)methylene)amino)ethyl]amine, 4-fim = 4-formylimidazole), was synthesized and the crystal structure was determined at 293 K. Cryomagnetic measurements revealed a two-step spin conversion and a pressure induced spin crossover was observed.
Synthesis, Characterization and Crystal Structure of the Water-Soluble, All-Inorganic Composition, A, β-Keggin Triniobium(V)-Substituted Polyoxotungstate
Authors: Nomiya Kenji , Hasegawa Takeshi , Noguchi Ryusuke , Nomura Kei-ichi , Takahashi Mizuto , Yokoyama Hironari 
Published: April 2003

Abstract
Triniobium(V)-substituted β-Keggin polyoxotungstate, K7[A, β-SiW9Nb3O40]·6H2O, as a soluble metal-oxide analogue and a metal-oxide support of the polyoxoanion-supported organometallic complexes, was synthesized, and the crystal and molecular structures of this polyoxoanion containing the Keggin A, β-SiW9 unit were successfully determined for the first time.
Preparation of “Confetti” Particles by Dispersion Copolymerization of Acrylonitrile/Styrene with Poly(ethylene glycol) Macromonomer
Authors: Chen Ming-Qing , Kaneko Tatsuo , Chen Chun-Hao , Akashi Mitsuru 
Published: April 2003

Abstract
The novel spherical particles on which nano-projections were uniformly distributed over the whole surface like “confetti” were prepared by dispersion copolymerization of acrylonitrile with styrene in ethanol/water mixed solvents in the presence of poly(ethylene glycol) (PEG) macromonomer. Transmission electron microscopy and laser light scattering studies showed particles with a narrow size-distribution. The diameter (ca. 150–1000nm) was controlled by changing the solvent composition and concentration of the PEG macromonomer.
Preparation of Li4/3Ti5/3O4 Thin Film Anode with High Electrochemical Response for Rechargeable Lithium Batteries by Sol–Gel Method
Authors: Rho Young Ho , Kanamura Kiyoshi , Umegaki Takao 
Published: April 2003

Abstract
A stoichiometric spinel Li4/3Ti5/3O4 thin film was prepared by a sol–gel method with poly(vinylpyrrolidone) (PVP) as an anode of rechargeable lithium micro-batteries. The prepared film was evaluated electrochemically by cyclic voltammetry (CV). One-time-coated thin film had 0.4 µm of thickness and showed high electrochemical response until 50 mV s−1. In this study, it was first reported that a thin film electrode with high electrochemical response was obtained by the sol–gel method with PVP.
An Efficient Method for the Preparation of Vicinal Tertiary Diamines by Reductive Coupling of Aminoacetals Mediated by Low Valent Titanium Iodide Species
Authors: Yoshimura Naritoshi , Mukaiyama Teruaki 
Published: April 2003

Abstract
Aminoacetals, easily prepared by condensation of aromatic aldehydes, secondary amines and alcohols, are reductively coupled by using low valent titanium iodide species to afford the corresponding coupling products, vicinal tertiary diamines, in good to high yields under mild reaction conditions.
Isolable Yet Highly Reactive Cationic Organoruthenium(II) Amidinates, [Ru(η6-C6R6)(η-amidinate)]+X−, Showing Signs of Coordinative Unsaturation: Isoelectronic Complexes of Ru(η5-C5Me5)(η-amidinate)
Authors: Hayashida Taizo , Yamaguchi Yoshitaka , Kirchner Karl , Nagashima Hideo 
Published: April 2003

Abstract
The coordinatively unsaturated ruthenium(II) complexes [Ru(η6-C6R6)(η-amidinate)]+X− (R = H, Me, X = TFPB, PF6), being isoelectronic with Ru(η5-C5Me5)(η-amidinate), have been isolated and characterized by spectroscopy and crystallography. A weak π-coordination of the amidinate ligands in the solid state was observed by X-ray crystallography. DFT calculations also suggest that such a coordination mode contributes to the stabilization of these complexes. These complexes behave as highly reactive transition metal Lewis acids in the reactions with various two-electron donor ligands.
Preparation of a New MOP Ligand Containing a Long-Chain Alkyl Group and Its Use for Palladium-Catalyzed Asymmetric Hydrosilylation of Cyclic 1,3-Dienes
Authors: Han Jin Wook , Hayashi Tamio 
Published: April 2003

Abstract
A new MOP ligand containing n-octyl group at 6 and 6′ positions of (R)-2-(diphenylphosphino)-2′-aryl-1,1′-binaphthyl skeleton was prepared and used for palladium-catalyzed asymmetric hydrosilylation of cyclic 1,3-dienes with trichlorosilane. By introduction of the n-octyl group, the palladium-phosphine catalyst became soluble in the reaction system, realizing high catalytic activity at a low reaction temperature.
Schülervorstellungen zum Boyle‐Versuch
Authors: Johannsmeyer Falko , Schneider Janine , Oetken Marco 
Published: April 2003

AbstractDAS GESETZ von der Erhaltung der Masse spielt bei der Vermittlung der Kriterien chemischer Reaktionen im Anfangsunterricht eine wesentliche Rolle. Es kann bereits auf phänomenologischer Ebene — zusammen mit dem Charakteristikum der Stoffumwandlung sowie des Energieumsatzes — erarbeitet werden. Nach der Einführung des Daltonschen Atommodells findet die Massenerhaltung wiederum eine überzeugende Interpretation mit der Vorstellung von der Existenz und dem Erhalt der Atome bei chemischen Reaktionen.
Experimente zur Decarboxylierung von Carbonsäuresalzen mit Natriumhydroxid
Authors: Heimann Rebekka , Mühlenschulte Nico , Oldenbürger Dirk , Thegelkamp Anja , Harsch Günther 
Published: April 2003

AbstractTHERMISCHE ZERSETZUNGEN sind geeignet, um eine Beziehung zwischen den Carbonsäuresalzen und den Alkanen herzustellen. In diesem Beitrag wird die Zersetzung von Propionat, Acetat und Malonat mit Natriumhydroxid beschrieben, wobei die beiden letzteren Synthesen zu definierten, mit schulischen Mitteln problemlos identifizierbaren Produkten führen.
Chemiedidaktik und Chemielehrer in der Mitte des 19. Jahrhunderts
Authors: Schmitz‐Wallrafen Norbert 
Published: April 2003

AbstractMIT DEM AUFBLÜHEN der Realanstalten und der fortschreitenden Etablierung des Faches Chemie rückten auch zunehmend Fragen der Gestaltung von Chemieunterricht in den Vordergrund. Dies soll anhand einiger Dokumente früher Chemiedidaktiker an Schulen in Rheinpreußen und anderer deutscher Länder belegt werden. Dabei wird deutlich, dass viele Fragen heutiger Chemiedidaktik früher schon gestellt und bearbeitet wurden.Gemeinhin gilt Rudolf Arendt als der Begründer einer Didaktik der Chemie [1, 2], eine These, die vor einiger Zeit von Just [3] noch untermauert wurde. Rudolf Arendt bzw. Ferdinand Wilbrand wird das Verdienst zugeschrieben, den Chemieunterricht in Schulen aus den Fesseln der Stoffsystematik der Hochschulen befreit zu haben. Dies kann jedoch nur eine Teilwahrheit sein, denn es gibt zahlreiche Dokumente in den so genannten Schulprogrammen aus der Zeit vor Arendt, die eine andere Sprache sprechen. Es ist an der Zeit, sie aus ihrem Schattendasein hervorzuholen und einer fachkundigen Öffentlichkeit zur Kenntnis zu bringen, damit sie eine entsprechende Würdigung erfahren. Im Rahmen meiner Arbeit [4] bin ich auf eine Fülle von Hinweisen in dieser Richtung gestoßen, die ich hier nicht alle ausbreiten kann. Zwei Dinge sollen jedoch stellvertretend besonders hervorgehoben werden. Es ist einmal das Wirken von drei Persönlichkeiten im Rheinland, die sich als Lehrer in der didaktischen Aufbereitung des Lehrstoffs in Chemie besonders hervorgetan haben. Dabei tut es ihren Verdiensten keinen Abbruch, dass die Unterlagen in den Archiven nicht immer alle Lebensdaten bereithalten. Des weiteren möchte ich auf eine Reihe von Dokumenten anderer Persönlichkeiten eingehen, die zeigen, dass die Wurzeln einer frühen Didaktik der Chemie nicht auf Rheinpreußen beschränkt waren.Die Genese des Schulfaches Chemie ist eng mit der Entwicklung der Realanstalten verknüpft. Da ist es naheliegend, bei der Suche nach den Wurzeln einer frühen Didaktik der Chemie bei den Praktikern vor Ort zu beginnen, die sich bei der Konzeption ihres Unterrichts erstmals mit didaktischen Fragestellungen des neuen Faches auseinandersetzen mussten und noch nicht auf einen Fundus anderweitig gesicherter Erkenntnisse zurückgreifen konnten.
Feed additives in animal nutrition: Quantification of a new adrenergic drug by hyphenated techniques
Authors: Bocca Beatrice , Cartoni Claudia , Mattia Michela Di , Fiori Maurizio , Felli Marialinda , Neri Bruno , Russo Mario Vincenzo , Brambilla Gianfranco 
Published: April 2003

AbstractZilpaterol, (±)‐trans‐4,5,6,7‐tetrahydro‐7‐hydroxy‐6‐(isopropylamino) imidazo [4,5,1‐jk]‐[1]benzazepin‐2(1H)‐one, is an adrenergic agonist drug licensed in Mexico and South Africa as feed additive for cattle at slaughter age. In contrast, the EU legislative framework prohibits the use of beta‐agonists as growth promoters to produce lean meat. In this study, the compound was quantified as its TMS derivative both by gas chromatography‐mass spectrometry (GC‐MS) with a quadrupole detector (QUADR) and by GC‐MS/MS with an ion trap detector (ITD), in Electron Impact (EI) ionization. Subsequently, an extraction and clean‐up procedure for the identification of Zilpaterol in commercial feeds was set up. Different extraction solvents and matrices were considered for their influence on Zilpaterol yield. The analytical method led to good recoveries and limits of detection and quantification in feeds well below the 5–20 μg/g dose proposed for animal nutrition.
Use of different anticoagulants for HPLC separation and quantification of the free amino acid content of plasma
Authors: Avino Pasquale , Campanella Luigi , Russo Mario Vincenzo 
Published: April 2003

AbstractAmino acid analysis in plasma samples is a very important and difficult task and could represent a useful tool for preventing the occurrence of some diseases (diabetes, cancer, HIV disease). Even though amino acid analysis has been thoroughly investigated, there are still some steps which are not so clear in this analytical procedure, e.g. the coagulation process of the blood to afford plasma and serum. Various anticoagulants are used in clinical chemistry: in this paper we have investigated three commonly used anticoagulants, heparin, EDTA, and sodium citrate. The blood samples have been divided into three portions and each portion treated with a different anticoagulant. The entire analytical procedure (from blood collection to the coagulation all the way to HPLC analysis) has been extensively investigated; the chromatograms and the amino acid recoveries are reported, and the three anticoagulants compared. Finally, the best anticoagulant has been used to analyze glycemic curves of healthy patients: the behavior of essential amino acids in the different blood samples withdrawn has been studied.