bluuebunny/crossref_metadata_2025 huggingface dataset:
The Cyanation of Aromatic Halides Catalyzed by Nickel(0) Complexes Generated in Situ. II. The Cyanation of Heteroaromatic Halides
Authors: Sakakibara Yasumasa , Ido Yoshinori , Sasaki Ken , Sakai Mutsuji , Uchino Norito
Published: August 2006

The cyanation of 3-bromopyridine catalyzed by in situ generated Ni(PPh3)n was examined with various MCN (M = K, Na)-dipolar aprotic solvent systems by four procedures. Under certain reaction conditions, 3-bromopyridine and several heteroaromatic halides were cyanated to give the corresponding nitriles in fair to good yields. Noticeable differences in reactivity among 3-bromopyridine, 3-bromofuran, 3-bromothiophene, and bromobenzene were observed.
Reductive Deconjugation of α-Bromo α,β-Unsaturated Esters Based on Redox Tautomerism of Diethyl Phosphonate
Authors: Hirao Toshikazu , Hirano Keisuke , Ohshiro Yoshiki
Published: August 2006

Reductive deconjugation of α-bromo α,β-unsaturated esters was performed by DP(O)(OEt)2 or P(OEt)3–H2O in the presence of triethylamine from mechanistic viewpoint and was applied to the synthesis of a precursor of (±)-patulolide A.
Photoreactions of 3,4,5,6-Tetrafluoro-N-methylphthalimide with Alkenes. Effect of Fluoro Substituents on Photoreaction Pathway
Authors: Kubo Yasuo , Umehara Tomoka
Published: August 2006

Photoreactions of 3,4,5,6-tetrafluoro-N-methylphthalimide (7) with styrene (8), α-methylstyrene (2), and 1,1-diphenylethylene (11) have been investigated in order to clarify the effect of fluoro substituents on the reaction pathway. The irradiation of 7 with 2, 8, and 11 in benzene under N2 gave oxetanes as exclusive products. The irradiation of 7 with 11 under O2 afforded benzophenone (13) together with the oxetane. The methanol-incorporated addition of 2 and 8 to 7 proceeded in photoreactions of 7 with 2 and 8 in methanol. A consideration of the energy levels of the excited triplet states of 7 and the alkenes, the quenching of the fluorescence of 7 by 8, and the concentration effects of the alkenes indicate that all of the reactions occur from the singlet excited state of 7. The difference between the exclusive oxetane formation of 7 and the preferred insertion of alkenes into the C–N bond of phthalimides is discussed regarding the nature of the singlet excited states of the imides. The methanol-incorporated addition and formation of 13 are rationalized in terms of mechanisms involving electron-transfer. The calculated ΔGet values associated with electron-transfer support the electron-transfer process.
Interaction between Copper Chlorophyllin and Poly(vinyl alcohol)
Authors: Enmanji Koe
Published: August 2006

The difference spectrum between copper chlorophyllin (Cu-chln) plus poly(vinyl alcohol) (PVA) and Cu-chln alone exhibits a maximum at 652 nm in water. The Benesi-Hildebrand plots give equilibrium constants of 833 mol−1 dm3 for UMR-20H (degree of saponification: 81.7%) and 1820 mol−1 dm3 for UMR-20M (degree of saponification: 63.8%). The Scatchard plot of these data shows the existence of a cooperative binding.
A Convenient Synthesis of Amides with 2-Halo-2,3-dihydro-1,3,4,2-oxadiazaphospholes as New Condensing Agents
Authors: Kimura Hiroshi , Konno Hidetoshi , Takahashi Naomichi
Published: August 2006

Various amides, including some with bulky substituents, are prepared in good yields from free carboxylic acids and amines under mild conditions by a one-step method using new condensing agents 2-halo-2,3-dihydro-1,3,4,2-oxadiazaphospholes, especially 5-methyl-2-chloro-3-phenyl-2,3-dihydro-1,3,4,2-oxadiazaphosphole.
Steric Effects in Photochemical Cycloadditions of 9-Phenanthrenecarboxylates
Authors: Itoh Hiroki , Shibata Hirofumi , Wagatsuma Marie , Nanjoh Mari , Senda Yasuhisa , Sakuragi Hirochika , Tokumaru Katsumi
Published: August 2006

Efficiency of photochemical intramolecular and intermolecular cycloaddition of 9-phenanthrenecarboxylate-anethole systems is dependent on the structure of anethole moiety. Reduction in reactivity of the anethole moiety by steric effects is explained in terms of decrease in coefficients of frontier orbitals on the double bond due to twisting of the anisyl moiety.
Correlation of Vibrational Zero-Point Energy Shifts of Hydrides upon H/D Isotope Substitutions with Electronegativity
Authors: Oi Takao , Ishida Takanobu
Published: August 2006

Correlation of the contribution of the stretching motion (δ(ZPE)str) to the zero-point energy shift upon H/D mono isotope substitution in HnA (n = 1—4) type hydrides with the electronegativity (χ) of the –Hn−1A moiety was investigated. It is possible to represent all the δ(ZPE)str-χ data by a single crude linear line. The line, however, is too crude to make precise estimation of the δ(ZPE)str value of a hydride from the χ value or to make precise estimation of the χ value from the δ(ZPE)str value. Much more accurate linear relation between δ(ZPE)str and χ can be obtained for each of HA, H2A, H3A, and H4A groups.
Picosecond LIF Studies on the Base-Catalyzed Proton-Transfer Reactions of Some Aminopyridines in Aqueous Solutions
Authors: Fujimoto Akira , Ando Hiroshi , Inuzuka Kozo , Nakamura Junko
Published: August 2006

Fluorescence quenching phenomena for systems of 2-aminopyridine (2-AP), 2,6-diaminopyridine (2,6-DAP), and 3,4-diaminopyridine (3,4-DAP) with sodium hydroxide in aqueous solutions were investigated by means of picosecond laser-induced fluorescence time-profile measurements. A comparison with the steady state fluorescence spectra of these systems showed that the former two amino compounds are successively catalyzed with sodium hydroxide in the excited state to form hydrogen-bonded exciplexes and anions, while 3,4-DAP showed normal fluorescence. The relations among the reaction rate constants for three aminopyridines are discussed.
Preparation and Metal Extraction Behavior of Macrocyclic Complexing Agent Bearing Trifluoromethanesulfonamide Deprotonating Groups
Authors: Kido Hirotsugu , Maeda Mizuo , Takagi Makoto
Published: August 2006

A diaza-18-crown-6 derivative bearing two trifluoromethanesulfonamide groups on N,N′-sites (1(H2L)) extracted divalent metal ions (M2+: Hg, Cu, Pb, Ca, Sr, Ba) into dichloromethane according to the reaction, M2+(aq) + H2L(org) ML(org) + 2H+(aq), Kex = [ML][H+]2/[H2L][M2+]. The magnitude of Kex values followed the order Hg > Pb > Cu >> Sr > Ca > Ba. This paralleled the selectivity obtained with the corresponding phenolic reagent, but the affinity to “soft” metal ions was enhanced for 1, reflecting the N,N,N−,N−-coordinating nature of 1. Moreover, 1 formed a 1 : 2 complex with Cu(II) by the reaction, M2+(aq) + 2H2L(org) M(HL)2(org) + 2H+(aq). This suggests that the 1 : 1 complex of Cu(II) was sterically hindered due to the coordination by the bulky sulfonamido groups.
ESR Spin-Trapping Study of Active Oxygen Radicals from Photoexcited Semiconductors in Aqueous H2O2 Solutions
Authors: Noda Hiroyuki , Oikawa Kazuo , Kamada Hitoshi
Published: August 2006

Experiments were carried out concerning the relation between the production of active oxygen radicals from three semiconductors [TiO2 (anatase and rutile) and WO3] and the concentration of H2O2 by the ESR spin-trapping technique using 5,5-dimethyl-1-pyrroline N-oxide (DMPO) as a spin trap. Two natures of hydroxyl radicals were produced from photoexcited semiconductors in aqueous H2O2 solutions. These originated in the reduction of H2O2 and the oxidation of water, which were confirmed using 17O-labeled water. The mechanism for the generation of active oxygen radicals is discussed regarding the energy band structures of the semiconductors, the redox potentials of the oxygen radicals, and the surface acidity and basicity of semiconductors.
Unusual Mesogenic Behavior of Laterally Di- and Tri-Substituted Schiff Bases
Authors: Gupta Renu , Vora R A
Published: August 2006

Three homologous Schiff base series, with basic skeleton of N-[4-(4′-n-alkoxybenzoyloxy)-3-methoxybenzylidene]aniline have been synthesized. The position and nature of the substitutent on the aniline moiety have been changed to find out their effects on the mesomorphism. Series I, with a 3-chloro substitutent do not exhibit mesomorphism. Series II, with a 2-methyl substituent in the aniline moiety exhibit monotropic smectic phase from the middle members of the series. However, Series III, having 5-chloro-2-methyl substituents behave like a normal nematogenic series.
The Effect of Solvent on the Synthesis of Pyridazinones and Some Reactions of the New Compounds
Authors: Sayed Galal Hosni , Radwan Azza , Hamed Ashraf Ahmed , Boraie Waleed El-Sayed
Published: August 2006

The reaction of 4-aryl-4-oxo-2-(5-oxo-1,3-diphenyl-2-pyrazolin-4-yl) butanoic acids with hydrazine hydrate in ethanol afforded the 4-(5-oxo-2-pyrazolin-4-yl)-3(2H)-pyridazinones and in 1-butanol a pyrazolo[3,4-c]pyridazino[4,3-e]pyridazine derivative was obtained while in acetic acid the 6-aryl-3(2H)-pyridazinone was the product. Probable mechanism has been proposed. The behavior of the 4-(5-oxo-2-pyrazolin-4-yl)-3(2H)-pyridazinones towards dimethyl sulfate, diethyl sulfate, ethyl bromoacetate, p-anisaldehyde, phosphoryl chloride and phosphorus pentasulfide has been studied.
The Estimation of the β-Sheet-Structure Stability of Protected Peptides in Organic Solvents
Authors: Narita Mitsuaki , Lee Jin-Shik , Hayashi Shizue , Hitomi Mitsuo
Published: August 2006

The β-sheet-structure stability in organic solvents was examined for protected tri- to heptapeptide fragments of E. coli ribosomal protein L7/L12. This was evaluated by monitoring the peptide IR absorption band around 1630 cm−1, assigned to a β-sheet structure, in CH2Cl2 alone or CH2Cl2 containing various concentrations of DMSO. For each peptide with a chain length up to a heptapeptide, the  values, defined in a previous paper, of a protected peptide were in harmony with their β-sheet-structure stability almost regardless of their amino acid sequences. This fact indicates that the  value is useful for the estimation of the β-sheet-structure stability of protected peptides in organic solvents. It also supports the assumption that the β-sheet-structure stability of protected peptides is strongly dependent on their amino acid compositions and weakly dependent on their amino acid sequences. Furthermore, it was shown that the  value of a protected peptide can provide a basis for the choice of reaction solvent. The significance of the present study in the design of synthetic routes for peptides and proteins is briefly discussed.
Lipase YS-Catalyzed Enantioselective Transesterification of Alcohols of Bicarbocyclic Compounds
Authors: Naemura Koichiro , Ida Hirotsugu , Fukuda Ritsuko
Published: August 2006

Lipase YS-catalyzed enantioselective acylations of (1RS, 2RS, 4RS, 5RS)-bicyclo[2.2.1]heptane-2,5-diol, (1RS, 2SR, 4RS, 5SR)-bicyclo[2.2.2]octane-2,5-diol, (1RS, 2RS, 4RS, 5RS)-bicyclo[2.2.2]octane-2,5-diol, and (1RS, 2SR, 5RS, 6SR)-bicyclo[3.3.1]nonane-2,6-diol with aryl acetates such as phenyl acetate, 1-naphthyl acetate, and 2-naphthyl acetate gave the monoacetates and the diols in optically active forms. The optical purities of (+)-(2R, 5R)-2-acetoxybicyclo[2.2.1]heptan-5-ol, (−)-(1S, 2R, 4S, 5R)-2-acetoxybicyclo[2.2.2]octan-5-ol, and (+)-(2R, 6R)-2-acetoxybicyclo[3.3.1]nonan-6-ol obtained using phenyl acetate were higher than those of the monoacetates which have been resolved by PLE-catalyzed hydrolysis of the corresponding racemic diacetates. Enzymic acylations of the diols using phenyl esters such as phenyl propanoate, phenyl butanoate, and phenyl octanoate as acylating agents gave the corresponding monoesters, which showed nearly the same enantiomeric excess value as the acetates. A simple model for predicting which enantiomer of racemic alcohols is acylated preferentially by lipase YS-catalyzed enantioselective transesterification is proposed on the basis of the results obtained here.
Reactivities of Stable Rotamers. XXXI. Bromine Addition to the Olefinic Moiety of Rotameric 1-(9-Fluorenyl)-2-(1-methylethenyl)naphthalenes
Authors: Oki Michinori , Shionoiri Katsumi , Otake Katsumasa , Ono Masaru , Toyota Shinji
Published: August 2006

Reaction of bromine with the ap form of the title compound afforded a normal addition compound, whereas the same with the sp form did no addition compound but a pair of bromo-olefins and a cyclized product, formation of which can be rationalized by deprotonation from and by attack of the π-system of the fluorene group on the intervening cation. The abnormal reactions of the sp form are the consequence of the steric effects of the fluorene moiety that prohibits the formation of the tetrahedral carbon at the reaction site. The stereochemistry of the cyclized product was determined both by NOE experiments and by X-ray crystallography. The stereoselective formation of only one isomer was rationalized by the structure of the starting material, of which stereodynamics was studied by the dynamic NMR method, and the direction of the attack of the bromine cation. For comparison of the fate of the intervening cation, the adduct from the ap form was treated with silver p-toluenesulfonate. It was found that the ratios of olefin formation were different from one rotamer to another. The results are discussed on the basis of different degree of openness of the intervening bromonium cation with reference to the same reaction for (1,2-dibromo-1-methylethyl)benzene.
Effects of the Linkage Length and Substituents on the Photocycloaddition of Bis(vinylnaphthyl)alkanes toward Naphthalenophanes
Authors: Nishimura Jun , Takeuchi Motoharu , Koike Masayuki , Sakamura Hideki , Yamashita Osamu , Okada Joji , Takaishi Naotake
Published: August 2006

Many naphtalenophanes, including a dicarbomethoxy-substituted one, a di-4-pyridyl-substituted one, and a bis(trimethylsilyl)-substituted one, were synthesized by applying intramolecular [2+2] photocycloaddition of α,ω-bis(1-vinylnaphthyl) alkanes. The effect of the linkage and substituents at the α and/or β positions of the vinyl groups was investigated concerning this photocycloaddition. From the results of the investigation, the limitation and scope of the photocycloaddition toward naphthalenophanes has been established.

In addition to this preparative study, an anomalous transannular photoproduct, which was formed from cis, exo-1,2-ethano-syn-[2.3](1,4)naphthalenophane and analyzed by X-ray crystallography, was found to undergo thermal cycloreversion through diene and tetraene intermediates. The kinetics of this reversion were studied. Moreover, some obtained naphthalenophanes showed an interesting tendency to form 1 : 1 mixed crystals with small flat-shaped recrystallization solvents having donor substituents. This nature is also briefly reported.
Application of Macroporous Glucomannan Hard Gel to High Performance Liquid Chromatographic Preparation of Coagulation Factor VIII
Authors: Yamaguchi Masato , Yamamoto Tetsuro , Tomoda Takashi , Motozato Yoshiaki
Published: August 2006

Glucomannan spherical hard gels with macroporous nature were 2-diethylaminoethylated (DEAE–) and evaluated for the applicability to preparation of blood coagulation factor VIII.

Adsorption capacity measured by a batch-wise method, of various kinds of DEAE-spherical gels to factor VIII in plasma cryoprecipitate fraction was apparently dependent on Mlim of the gels. DEAE-GM gel (Mlim 1 × 107) possessed the capacity at least 2 to 3 fold higher than those of EMD DEAE-650®, DEAE-Toyopearl 650® and DEAE-Cellulofine A-800®. DEAE-GM gel (Mlim 1 × 107) was applied to high performance liquid chromatographic (HPLC) preparation of factor VIII from plasma cryoprecipitate fraction under high flow rates as rapid as 1 to 4 m h−1 in linear velocity. DEAE-GM gel columns in HPLC possessed the high adsorption capacity (30 to 60 U/ml–gel) and good elution recovery from column (51—83%) accompanied by the resulting specific activity as good as 22-113 U/mg–protein. DEAE-GM gel must be a suitable tool in column chromatographic separation of factor VIII and other large proteins in manufacture scale.
Preparation of Niobia/Alumina as a Mixed Oxide Aerogel
Authors: Maurer Scott M , Ko Edmond I
Published: August 2006

A niobia (Nb2O5)/alumina (Al2O3) mixed oxide, containing 25 weight percent niobia, was synthesized as an aerogel by using alkoxides as precursors and supercritical carbon dioxide in the drying step. After calcination at 773 K for two hours, this sample had a BET surface area of 450 m2 g−1 and was X-ray amorphous, and contained primarily Lewis acid sites.
Effect of Trifluoperazine-Binding on Aggregates of S-100 Proteins
Authors: Matsuda Sadayuki
Published: August 2006

Aggregates (oligomers) of both S-100b and a mixture of S-100a and S-100a′ (S-100a.a′) were characterized using HPLC of gel filtration. The addition of trifluoperazine to S-100a.a′ resulted in the disappearance of the aggregates irrespective of zinc ion binding. The aggregates of S-100b dissociated into dimeric form of S-100b only in the presence of EDTA.
Relative Reactivities of Some Polycyclic Aromatic Hydrocarbons in Catalytic Hydrogenation over Raney Nickel
Authors: Minabe Masahiro , Urushibara Shuuichi , Mishina Fumihiko , Kimura Takao , Tsubota Motohiro
Published: August 2006

Catalytic hydrogenation of 9H-fluorene (1), phenanthrene (2), 4H-cyclopenta[def ]phenanthrene (3), pyrene (4), and fluoranthene (5) was carried out over Raney nickel (W-7) at 323 K under 608 kPa of hydrogen. The order of the reaction rate was 5 > 4 > 3 > 2 > 1. The adsorption equilibrium constant of the substrates decreased in the order 4 ≥ 5 >> 2 > 3 >> 1.
Effect of Ether Oxygen in Isomeric Alcohols on Water Structure Estimated from Ultrasonic Absorption and Velocity Data
Authors: Nishikawa Sadakatsu , Matsumura Kenichi , Ueda Masayuki
Published: August 2006

4-Methoxy-1-butanol was synthesized form 1,4-butanediol through potassium 4-hydroxy-1-butoxide. The ultrasonic absorption coefficients in the frequency range from 9.5 to 220 MHz and the sound velocity at 2.5 and 1.92 MHz were measured in aqueous solutions as a function of the concentration. A single relaxational absorption was observed, the cause of which was attributed to the perturbation of an equlibrium associated with a solute–solvent interaction. The rate and thermodynamic parameters associated with the interacion were determined from the concentration dependence of the relaxation frequency. The results were compared with those for other isomeric alcohol solutions, and the effect of the alcohols on the water structure was considered in relation to the molecular structures of the solutes. It has been found that the position of the ether oxygen in the alcohol molecules gives rise to a considerable change in the solution properties.
A Revised MM2 Force Field for the Normal Mode Vibrational Analysis of Glucopyranose
Authors: Murata Masashi , Yoshie Naoko , Sakurai Minoru , Inoue Yoshio
Published: August 2006

A revised MM2 force field is developed for the study of normal mode dynamics of glucopyranose. The revised potential function is found to reproduce the vibrational spectrum and equilibrium structure of d-glucopyranose better than the original parameter set.
High Affinity of a Macrobicyclic Cu(II) Complex to Halide Ions and Application of the Complex in Kinetics of the Menschutkin Reaction
Authors: Kang Shin-Geol , Jung Soo-Kyung , Kim Mi-Seon , Park Jong-Hwan , Yoh Soo-Dong
Published: August 2006

The equilibrium constants (K) for the reaction [Cu(A)]2+ + X− [Cu(A)X]+ (A = 1,3,6,9,12-pentaazabicyclo[10.2.1] pentadecane; X− = Br− or Cl−) in acetonitrile, DMF, and DMSO have been determined at 25 °C. The large K values (>8.8 × 104) and other results show that the copper(II) complex can be used as a probe for kinetic study of the Menschutkin reaction even in the basic solvents.
Convenient Synthesis of Some Styrylpyridinium Dyes Containing Methylenebis[benzenamine] Moiety
Authors: Peesapati Venkateswarlu , Rao Ummaneni Narasimha , Pethrick Richard A
Published: August 2006

Condensation of 4-vinylpyridine with 4,4′-[(4-bromophenyl) methylene]bis[benzenamine] and its N-ethyl analogue adopting Heck's reaction yielded corresponding new styrylpyridines which were converted into their pyridinium bromides. All the compounds reported were characterized by analytical and spectral data.
X-ray Structures and Dipole Moments of Tropones Annulated with Furan, Benzene, and Oxepin
Authors: Kudoh Mitsutaka , Sudoh Susumu , Katagiri Shigeyoshi , Nakazawa Tomoo , Ishihara Mariko , Jinguji Mamoru , Higashi Miwako , Yamaguchi Hiroyuki , Miyatake Ryuta , Sugihara Yoshikazu , Kabuto Chizuko
Published: August 2006

The precise X-ray structures of furo[3,4-d]tropone (2), 2,4-dimethyl-8H-3-oxaheptalen-8-one (5), and 4,5-benzotropone (6) were determined. Their tropone rings show definite bond alternation and nearly planar conformation, though slightly boat-shaped like polycyclic tropone. The ground-state dipole moments of 2, 5, and 6, and also 8H-3-oxaheptalen-8-one (3) and 2-methyl-8H-3-oxaheptalen-8-one (4) were measured in benzene at 25 °C. Analyses of the ground-state dipole moments by means of ab initio calculations demonstrate that the polar structures of 2 and 6 having an annulated aromatic ring are based on the local dipoles of penta-1,4-dien-3-one and the induced dipole of the annulated ring, whereas those of 3 and 5 are based not only on the local dipoles but also on the partial intramolecular CT interaction from the olefinic oxepin ring to the pentadienone moiety. According to the McRae equation, the dipole moments of the two lowest excited states of 2, 3, 5, and 6 were evaluated by using the frequency shifts of the absorption maxima in a number of polar and nonpolar solvents. They are all oriented in the same direction as that of the ground state, but are greater in magnitude.
Inclusion Properties of 11b-Substituted 2,3,5,6,11,11b-Hexahydro-3-oxo-1H-indolizino[8,7-b]indole-5-carboxylic Acid Esters. New Chiral Host Compounds Derived from l-Tryptophan
Authors: Morinaga Masanori , Taniguchi Masahiro , Sonogi Tsuyoshi , Watanabe Gou , Kitawaki Takaya , Kondo Mitsuru , Irikawa Hajime
Published: August 2006

New chiral host compounds have been prepared from l-tryptophan and 3-aroylpropionic acids. These hosts show broad inclusion and sorption abilities toward solvent and racemic molecules, and are characterized by X-ray crystallographic analysis, which clarify the one-dimensional channel structures of the hosts, the helical arrangements of the guests, and the occurrence of weak interactions such as C–H···O and C–H···Cl between the hosts and the guests. The TG and DTA data show the high cohesion of the hosts, and the PXRD patterns indicate that the crystal structures of the hosts remain ordered after removal of the guest molecules. These hosts have potential usefulness in the optical resolution of racemic guest molecules such as s-butyl chloride and 4-methylcyclohexene.
Diels–Alder Reaction of Cyclopentadienone Acetal with Pyrrole and Indole
Authors: Sato Sota , Fujino Tomoko , Isobe Hiroyuki , Nakamura Eiichi
Published: August 2006

Diels–Alder reactions of a cyclopentadienone acetal with aromatic heterocycles, such as pyrrole or indole, took place with the latter acting as a 2π dienophile. The reaction gave a polycyclic heterocycle in good yield regioselectively. Analysis of the frontier molecular orbitals showed that inverse electron demand interactions control the regioselectivity.
Risk Factors for Heatstroke among Japanese Forestry Workers
Authors: Maeda Takafumi , Kaneko Shin‐ya , Ohta Mitsuhiro , Tanaka Kazuko , Sasaki Akihiko , Fukushima Tetsuhito
Published: August 2006

Risk Factors for Heatstroke among Japanese Forestry Workers: Takafumi Maeda, et al. Department of Hygiene and Preventive Medicine, Fukushima Medical University School of Medicine—We examined the risk factors for heatstroke among forestry workers in Japan during the summer. We distributed a questionnaire to 124 forestry workers to determine heatstroke symptoms, degree of sweating and hydration, as well as perceived hotness and amount of sunlight at work sites. Forty of the workers (32.3%) reported experiencing heatstroke symptoms. Thirteen and 21 of them reported such symptoms during July and August, respectively. Eleven workers experienced heatstroke at around 14:00; 5 and 4 developed symptoms at around 11:00 and 10:00, respectively. Groups with and without heatstroke symptoms significantly differed in terms of perceived hotness (p<0.05), sunlight (p<0.05), degree of sweating (p<0.01) and frequency of hydration (p<0.05) while working. Heatstroke symptoms developed in 60.6% of workers aged up to 50 yr, but in only 22.0% of those over the age of 51 (p<0.01). Multiple regression analysis selected the following key variables associated with the development of heatstroke symptoms (R2=0.236 and p=0.006): frequency of urination, hotness, BMI and years of forestry work (standard coefficients: +0.229, +0.194, +0.280 and −0.162, respectively). The results of the present study showed that one third of forestry workers developed some symptoms of early heatstroke during summer forestry work. Furthermore, the results indicate that a short duration of forestry service was one of the risk factors contributing to the onset of heatstroke, in addition to heat stress, loss of body water and electrolytes, and obesity.
Increased Susceptibility to Varicella‐Zoster Virus among Israeli Physicians and Nurses Born in the Middle‐East Region
Authors: Chodick Gabriel , Ashkenazi Shai , Livni Gilat , Lerman Yehuda
Published: August 2006

Increased Susceptibility to Varicella‐Zoster Virus among Israeli Physicians and Nurses Born in the Middle‐East Region: Gabriel Chodick, et al. Sackler Faculty of Medicine, Tel‐Aviv University, Israel—Nosocomial transmission of varicella‐zoster virus (VZV) is recognized as a significant cause of morbidity in health care workers as well as in high‐risk patients. The current study aimed to investigate the presence of VZV antibodies among physicians and nurses, to assess the variables affecting it, and to compare it with previous international studies. Data were obtained by a questionnaire regarding sociodemographic and occupational characteristics and by determination of serum antibodies to varicella‐zoster. The seroprevalence of varicella‐zoster among the 335 study participants was 94.8% (95%CI: 91.9%–96.9%), with no significant difference between nurses (94%) and physicians (97%). Decreased risk for the virus was observed in workers who immigrated to Israel from the Asia or Africa (OR=0.15; 95% CI: 0.04–0.51). Reduced immunity among these workers remained significant in a multivariate model, which also included age, gender, years of education, number of siblings, and crowding at childhood. Our data suggest that in spite of the high immunity among Israeli physicians and nurses in general, the implementation of small‐scale vaccination programs aimed at workers from warmer and tropical areas, should be seriously considered.
Prolactin Levels in Workers Exposed to Chemical, Physical and Psycho‐Social Urban Stressors
Authors: Tomei Francesco , Ciarrocca Manuela , Cherubini Emilia , Rosati Maria V. , Monti Carlo , Capozzella Assunta , Tomei Gianfranco
Published: August 2006

Prolactin Levels in Workers Exposed to Chemical, Physical and Psycho‐Social Urban Stressors: Francesco Tomei, et al. Department of Occupational Medicine, University of Rome “La Sapienza”, Italy—The aim of this study was to evaluate whether traffic police officers exposed to chemical, physical and psycho‐social stressors, are at risk for alterations in plasma levels of prolactin (PRL) compared to a control group. Plasma PRL levels were evaluated in 92 male and 51 female, non‐smoker, traffic police officers exposed to urban stressors and in 92 male and 51 female controls, matched by sex, age and working life (mean, SD and distribution), after excluding workers with the principal extra‐occupational confounding factors. Mean PRL levels were significantly higher than controls in non‐smoker, male and female traffic police officers (respectively, p=0.000 and p=0.013). The number of non‐smoker, male and female traffic police officers with PRL values outside the upper normal limit for our laboratory was higher than, but not significantly different from controls. Mean PRL levels were not significantly higher than controls in smoker, male and female traffic police officers. The number of smoker, male and female traffic police officers with PRL values outside the normal limit for our laboratory was not significantly different from controls. The results suggest that exposure to urban chemical and physical stressors, interacting with psychosocial factors, may have an influence on PRL levels in traffic police officers. The level of plasma PRL might be a useful early biological marker for workers exposed to urban stressors.
Aberrant Promoter Methylation of p16INK4a and O6‐Methylguanine‐DNA Methyltransferase Genes in Workers at a Chinese Uranium Mine
Authors: Su Shibiao , Jin Yali , Zhang Wei , Yang Lujing , Shen Yueping , Cao Yi , Tong Jian
Published: August 2006

Aberrant Promoter Methylation of p16INK4a and O6‐Methylguanine‐DNA Methyltransferase Genes in Workers at a Chinese Uranium Mine: Shibiao SU, et al. Department of Toxicology, School of Radiation Medicine and Public Health, Soochow University, China—To find the possible association of gene methylation of p16INK4a and O6‐Methylguanine‐DNA Methyltransferase (O6‐MGMT) with occupational exposure to radon, 91 male miners from a uranium mine in China were divided into 4 groups according to the cumulative doses of radon exposure from 2 to 425 WLM (working‐level months), and aberrant promoter methylation of p16INK4a and O6‐MGMT genes in sputum samples was determined by a specific PCR assay. The results revealed that the methylated rates of p16INK4a gene (z=2.844, P=0.005) and O6‐MGMT gene (z=3.034, P=0.002), and the total methylated rate of these two genes (z=3.859, P=0.0001) increased significantly with the cumulative doses of radon among the miners. This methylation could be applied as a potential marker for the detection of early DNA damage induced by occupational radon exposure.
Using Urine Specific Gravity to Evaluate the Hydration Status of Workers Working in an Ultra‐Low Humidity Environment
Authors: Su Shih‐Bin , Lin Kuen‐Huei , Chang Ho‐Yuan , Lee Chai‐Wei , Lu Chih‐Wei , Guo How‐Ran
Published: August 2006

Using Urine Specific Gravity to Evaluate the Hydration Status of Workers Working in an Ultra‐Low Humidity Environment: Shih‐Bin SU, et al. Department of Environmental and Occupational Health, Medical College, National Cheng Kung University, Taiwan—In environments with ultra‐low humidity, workers may have excessive body water loss due to evaporation through the skin, which can lead to dehydration. Before the development of clinical symptoms and signs, concentrated urine may be applied as an early indicator of dehydration. We used urine specific gravity (USG) as a biomarker to evaluate the hydration status of workers working in such an environment. We collected the urine samples from workers at a lithium battery plant during their annual health examination, and the relative humidity of some working areas called “dry rooms” in the plant was 1.5 ± 1%. We recruited workers in those dry rooms as the exposure group (N=50) and defined the remaining workers, including administration office workers, as the comparison group (N=122). The prevalence of abnormally concentrated urine (USG>1.030) and related factors were compared between these two groups. While the exposure group were younger and had shorter employment durations compared to the comparison group (p<0.05), they had a higher prevalence of abnormally concentrated urine (p<0.01). After adjusting for age, gender, employment duration, and body surface area, we found that working in the dry rooms was associated with an odds ratio of 11.9 (95% confidence interval: 2.5 to 56.9) of having abnormally concentrated urine. Therefore, USG is a good biomarker for evaluating the hydration status of workers working in ultra‐low humidity environments, who need proper protection and adequate fluid supply to prevent excess water loss and its adverse health effects.
A simple linear sweep voltammetric method for the determination of double-stranded DNA with malachite green
Authors: Sun W. , You J. , Hu X. , Jiao K.
Published: August 2006

In pH 3.5 Britton—Robinson buffer solution double-stranded (ds) DNA can react with malachite green (MG) to form an interaction complex, which resulted in the decrease of the electrochemical response of MG, MG had a well-defined second-order derivative linear sweep voltammetric peak at −0.73 V (vs. SCE). After the addition of dsDNA into MG solution, the reductive peak current decreased with the positive shift of peak potential, which was the typical characteristic of intercalation. Based on the interaction, an indirect electrochemical determination method for dsDNA was established. The optimum conditions for the reaction were investigated and there were little or no interferences from the commonly coexisting substances. The decrease of peak current was linear with the concentration of dsDNA over the range of 0.8–12.0 µg cm−3 with the linear regression equation as ΔI p″/nA = 91.70 C/(µg cm−3) + 74.55 (n = 10, γ = 0.990). The detection limit was calculated as 0.46 µg cm−3 (3σ). The method had high sensitivity and was further applied to the dsDNA synthetic samples with satisfactory result. The interaction mechanism was discussed with the intercalation of DNA-MG to form a supramolecular complex and the stoichiometry of the supramolecular complex was calculated by electrochemical method with the binding number 3 and the binding constant 2.35 × 1015 (mol dm−3)−3.
Mutation analysis of the FRAS1 gene demonstrates new mutations in a propositus with Fraser syndrome
Authors: Slavotinek A. , Li C. , Sherr E.H. , Chudley A.E.
Published: August 2006

Fraser syndrome (OMIM 219000) is a rare, autosomal recessive condition with classical features of cryptophthalmos, syndactyly, ambiguous genitalia, laryngeal, and genitourinary malformations, oral clefting and mental retardation. Mutations causing loss of function of the FRAS1 gene have been demonstrated in five patients with Fraser syndrome. However, no phenotype–genotype correlation was established and there was evidence for genetic heterogeneity. Fraser syndrome is rare and the FRAS1 gene has 75 exons, complicating mutation screening in affected patients. We have screened two patients who fulfilled the diagnostic criteria for Fraser syndrome and three patients with related phenotypes (two patients with Manitoba oculotrichoanal syndrome and one patient with unilateral cryptophthalmos and labial fusion) for mutations in FRAS1 to increase the molecular genetic data in patients with Fraser syndrome and related conditions. We report two new mutations in a patient with Fraser syndrome, a frameshift mutation and a deletion of two amino acids that we consider pathogenic as both alter the NG2‐like domain of the protein. Although we are still unable to clarify a phenotype–genotype relationship in Fraser syndrome, our data add to the list of mutations associated with this syndrome. © 2006 Wiley‐Liss, Inc.
Pooled association genome scanning for alcohol dependence using 104,268 SNPs: Validation and use to identify alcoholism vulnerability loci in unrelated individuals from the collaborative study on the genetics of alcoholism
Authors: Johnson Catherine , Drgon Tomas , Liu Qing‐Rong , Walther Donna , Edenberg Howard , Rice John , Foroud Tatiana , Uhl George R.
Published: August 2006

Association genome scanning can identify markers for the allelic variants that contribute to vulnerability to complex disorders, including alcohol dependence. To improve the power and feasibility of this approach, we report validation of “100k” microarray‐based allelic frequency assessments in pooled DNA samples. We then use this approach with unrelated alcohol‐dependent versus control individuals sampled from pedigrees collected by the Collaborative Study on the Genetics of Alcoholism (COGA). Allele frequency differences between alcohol‐dependent and control individuals are assessed in quadruplicate at 104,268 autosomal SNPs in pooled samples. One hundred eighty‐eight SNPs provide (1) the largest allele frequency differences between dependent versus control individuals; (2) t values ≥ 3 for these differences; and (3) clustering, so that 51 relatively small chromosomal regions contain at least three SNPs that satisfy criteria 1 and 2 above (Monte Carlo P = 0.00034). These positive SNP clusters nominate interesting genes whose products are implicated in cellular signaling, gene regulation, development, “cell adhesion,” and Mendelian disorders. The results converge with linkage and association results for alcohol and other addictive phenotypes. The data support polygenic contributions to vulnerability to alcohol dependence. These SNPs provide new tools to aid the understanding, prevention, and treatment of alcohol abuse and dependence. © 2006 Wiley‐Liss, Inc.
Linkage disequilibrium, haplotype and association studies of a chromosome 4 GABA receptor gene cluster: Candidate gene variants for addictions
Authors: Drgon Tomas , D'Addario Claudio , Uhl George R.
Published: August 2006

Strong genetic contributions to individual differences in vulnerability to addictions are well supported by classical genetic studies. Linkage and association genome scans for addiction vulnerability have provided converging evidence for several chromosomal regions which are likely to harbor allelic variants that contribute to such vulnerability. We and others have delineated a candidate addiction‐associated chromosome 4p12 “rSA3” region based on convergent data from association genome scanning studies in polysubstance abusers [Uhl et al. (2001); Am J Hum Genet 69(6):1290–1300], linkage‐based studies in alcoholism [Long et al. (1998); Am J Med Genet 81(3):216–221; Reich et al. (1998); Am J Med Genet 81(3):207–215] and association‐based studies for alcoholism and association‐based studies for individual differences in electroencephalographic (EEG) spectral power phenotypes [Porjesz et al. (2002); Proc Natl Acad Sci USA 99(6):3729–3733; Edenberg et al. (2004); Am J Hum Genet 74(4):705–714]. The rSA3 region contains interesting candidate genes that encode the alpha 2, alpha 4, beta 1, and gamma 1 receptor subunits for the principal brain inhibitory neurotransmitter, γ‐aminobutyric acid (GABA) [Covault et al. (2004); Am J Med Genet Part B 129B:104–109; Edenberg et al. (2004); Am J Hum Genet 74(4):705–714; Lappalainen et al. (2005); Alcohol Clin Exp Res 29(4):493–498]. We now report assessment of single nucleotide polymorphism (SNP) genotypes in this region in three samples of substance abusers and controls. These results delineate the haplotypes and patterns of linkage disequilibrium in this region, focus attention of the GABRA2 gene and identify modest associations between GABRA2 genotypes and addiction phenotypes. These results are consistent with modest roles for GABRA2 variants in addiction vulnerabilities. © 2006 Wiley‐Liss, Inc.
A review and re‐evaluation of an association between the NOTCH4 locus and schizophrenia
Authors: Wang Zhenqi , Wei Jun , Zhang Xuan , Guo Yingjun , Xu Qi , Liu Shuzheng , Shi Jieping , Yu Yaqin , Ju Guizhi , Li Yulin , Shen Yan
Published: August 2006

This work reviewed all the reports on the NOTCH4 gene in schizophrenia, which have been published since the gene was found to be associated with illness among a British population in 2000. The results from independent studies were inconsistent. Allelic heterogeneity, clinical diagnosis, ethnical backgrounds, and linkage disequilibrium (LD) structures in the human genome may be major reasons for poor replication. A couple of studies suggested that the NOTCH4 gene could play a role in a subgroup of the disease, such as early‐onset schizophrenia and negative symptoms. A single study revealed a weak association of the NOTCH4 gene with frontal lobe brain volumes and a strong association with frontal lobe cognitive performance. A meta‐analysis showed stronger evidence of the NOTCH4 association in family‐based studies than in case‐control studies. In a previous study, we found that rs520692, a single nucleotide polymorphism (SNP) at the NOTCH4 locus, was associated with schizophrenia in a Chinese population. In the present study, we applied a large sample size to re‐evaluate our initial findings and then confirmed the rs520692 association with illness. The pairwise measures did not show strong LD between paired SNPs although the SNPs tested are located within a 34‐kb region, suggesting that LD within the NOTCH4 gene has been broken rapidly by historical recombination in the Chinese population. Taken together, the NOTCH4 gene may be associated with schizophrenia but how the gene contributes to the etiology of the illness needs a further investigation. © 2006 Wiley‐Liss, Inc.
Titelbild: Crystalline Nanoflowers with Different Chemical Compositions and Physical Properties Grown by Limited Ligand Protection (Angew. Chem. 32/2006)
Authors: Narayanaswamy Arun , Xu Huifang , Pradhan Narayan , Peng Xiaogang
Published: August 2006

Einkristall‐Nanoblumen …︁…︁ (siehe Titelbild) wurden mit einem allgemeinen Verfahren gezogen, das eingeschränkter Ligandenschutz (LLP) genannt wird. LLP destabilisiert die primären Nanopartikel und fördert ihr dreidimensional ausgerichtetes Zusammenlagern zu komplexen Nanostrukturen. Da LLP einen geringen Ligandenschutz bietet, könnte sich die gleiche Methode auch für den Aufbau von Nanopunkten eignen. Details finden sich in der Zuschrift von X. Peng et al. auf S. 5487 ff.
Cover Picture: Crystalline Nanoflowers with Different Chemical Compositions and Physical Properties Grown by Limited Ligand Protection (Angew. Chem. Int. Ed. 32/2006)
Authors: Narayanaswamy Arun , Xu Huifang , Pradhan Narayan , Peng Xiaogang
Published: August 2006

Single‐crystal nanoflowers …︁…︁ (shown in the cover picture) are grown by a general approach called limited ligand protection (LLP). LLP destabilizes the primary nanoparticles and promotes their three‐dimensionally oriented attachment into complex nanostructures. LLP offers a low degree of ligand protection and can be used to yield both nanodots and nanoflowers. For more information see the Communication by X. Peng and co‐workers on page 5361 ff.
Shape‐controlled synthesis of Pt nanocrystals: an evolution of the tetrahedral shape
Authors: Yu Ying‐Tao , Xu Bo‐Qing
Published: August 2006

Platinum nanocrystals with sizes smaller than 10 nm are obtained by H2‐reduction of aqueous K2PtCl6 in the presence of different concentrations of poly (N‐vinyl‐2‐pyrrolidone; PVP:Mw ≈ 360 000) at pH = 2.5–7.0. Tetrahedral Pt nanocrystals (3–10 nm) are produced with high selectivity (73–83% by number) at moderate PVP:K2PtCl6 ratios. The co‐existing round/spheroidal crystallites are found to be smaller than the tetrahedrally shaped ones in the systems of varying K2PtCl6:PVP ratios. Careful examinations of the particle size and shape evolution of the crystallites at different stages of the crystal growth with transmission electron microscopy (TEM) and ultraviolet–visible absorption spectroscopy (UV–vis) suggest that the tetradedrally shaped Pt crystallites share the same type of nuclei with the round ones at the early stage of the crystal formation. Evolution of the tetrahedral shape happens in the later slow crystal growth. Copyright © 2006 John Wiley & Sons, Ltd.
One‐pot dual size‐ and shape selective synthesis of tetrahedral Pt nanoparticles
Authors: Kinge S. , Bönnemann H.
Published: August 2006

One‐pot dual size‐ and shape‐selective synthesis of tetrahedral Pt nanoparticles is achieved using the pre‐prepared Pt nanoparticles as the ‘external seeds’, and controlling the slow diffusional growth under hydrogen reduction in the presence of PVP as the capping agent. Copyright © 2006 John Wiley & Sons, Ltd.
Silyl modification of biologically active compounds. 12. Silyl group as true incentive to antitumour and antibacterial action of choline and colamine analogues
Authors: Zablotskaya Alla , Segal Izolda , Popelis Yuris , Lukevics Edmunds , Baluja Shipra , Shestakova Irina , Domracheva Ilona
Published: August 2006

A series of triorganylsilyl(β‐dialkylaminoethoxy)silanes was prepared and characterized by elemental analysis, 1H, 13C, 29Si NMR and mass spectroscopy. Comparative study of 29Si resonance of newly synthesized compounds showed correlation between its value and substituent nature at the silicon atom, and is shifted upfield for β‐triorganyl(N,N‐dialkylaminoethoxy)silanes in comparison with corresponding methiodides, revealing weak N…Si interaction for proper silanes. In vitro antitumour and antimicrobial properties were investigated. The biological activity data exhibited a marked enhancement of inhibitory activity on trialkylsilylation against tumour cell lines and all the test bacterial/fungal strains. Copyright © 2006 John Wiley & Sons, Ltd.
UV laser deposition of nanostructured Si/C/O/N/H from disilazane precursors and evolution to silicon oxycarbonitride
Authors: Pola Josef , Galíková Anna , Bastl Zdeněk , Šubrt Jan , Vacek Karel , Brus Jiří , Ouchi Akihiko
Published: August 2006

Megawatt ArF laser photolysis of gaseous methyldisilazanes [(CH3)nH3−nSi]2NH (n = 2, 3) in excess of Ar yields hydrocarbons (major volatile products), methylsilanes (minor volatile products) and allows chemical vapour deposition of solid amorphous Si/C/O/N/H powder containing SiX (XC, H, O, N) bonds. The incorporation of O is due to a high reactivity of the primarily formed products towards air moisture. The resulting solid materials possess nanometer‐sized texture and high specific area, contain Si‐centered radicals and anneal under argon to silicon oxycarbonitride, whose structure is described as a network of O‐ and N‐interconnected Si and C atoms. Copyright © 2006 John Wiley & Sons, Ltd.
Clavicle, a neglected bone: Morphology and relation to arm movements and shoulder architecture in primates
Authors: Voisin Jean‐Luc
Published: August 2006

In spite of its importance for movements of the upper limbs, the clavicle is an infrequently studied shoulder bone. The present study compares clavicular morphology among different extant primates. Methods have included the assessment of clavicular curvatures projected on two perpendicular planes that can be assessed overall as cranial and dorsal primary curvatures. Results showed that in cranial view, three morphologies can be defined. One group exhibited an external curvature considerably more pronounced than the internal one (Gorilla, Papio); a second group was characterized by an internal curvature much more pronounced than the external one (Hylobates, Ateles); and a third group contained those with the two curvatures equally pronounced (Pan, Homo, Pongo, Procolobus, Colobus). Clavicle curvatures projected on the dorsal plane could be placed into four groups. The first group is characterized by two curvatures, an inferior and a superior (Apes, Spider monkeys). The second included monkeys, whose clavicles have an inferior curvature much more pronounced than the superior one. The third group includes only Hylobates, whose clavicles possess only the superior curvature. The last group includes only modern humans, whose clavicles show only the inferior curvature, which is less pronounced than that which exists in monkeys. Curvatures in cranial view relate information regarding the parameters of arm elevation while those in dorsal view offer insights into the position of the scapula related to the thorax. The use of clavicular curvature analysis offers a new dimension in assessment of the functional morphology of the clavicle and its relationship to the shoulder complex. Anat Rec Part A, 288A:944–953, 2006. © 2006 Wiley‐Liss, Inc.