bluuebunny/crossref_metadata_2025_split huggingface dataset:
ChemInform Abstract: Silicon‐, Germanium‐, and Tin‐Centered Cations, Radicals, and Anions
Authors: Lee Vladimir Ya. , Sekiguchi Akira 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: The Mitsunobu Reaction: Origin, Mechanism, Improvements, and Applications
Authors: But Tracy Yuen Sze , Toy Patrick H. 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Some Novel Aminopropyl Nucleoside Phosphonates
Authors: Zhou Ding , Lagoja Irene M. , Van Aerschot Arthur 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Nucleosides and Oligonucleotides with Diynyl Side Chains: The Huisgen‐Sharpless Cycloaddition “Click Reaction” Performed on DNA and Their Constituents
Authors: Seela Frank , Sirivolu Venkata Ramana 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Development of an Antitumor Adenosine Analogue, 3′‐Ethynyladenosine
Authors: Endo Yoshio , Obata Tohru , Nomura Makoto , Fukushima Masakazu , Yamada Yuji , Matsuda Akira , Sasaki Takuma 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Crystallographic Study of Cyclodextrins and Their Inclusion Complexes
Authors: Harata Kazuaki 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Role of acetylcholine in nitric oxide production in the salamander retina
Authors: Cimini Beth A. , Strang Christianne E. , Wotring Virginia E. , Keyser Kent T. , Eldred William D. 
Published: February 2008

AbstractAlthough acetylcholine is one of the most widely studied neurotransmitters in the retina, many questions remain about its downstream signaling mechanisms. In this study we initially characterized the cholinergic neurotransmitter system in the salamander retina by localizing a variety of cholinergic markers. We then examined the link between both muscarinic and nicotinic receptor activation and nitric oxide production by using immunocytochemistry for cyclic guanosine monophosphate (cGMP) as an indicator. We found a large increase in cGMP‐like immunoreactivity (cGMP‐LI) in the inner retina in response to muscarinic (but not nicotinic) receptor activation. Based on the amplification of mRNA transcripts, receptor immunocytochemistry, and the use of selective antagonists, we identified these receptors as M2 muscarinic receptors. Using double‐labeling techniques, we established that these increases in cGMP‐LI were seen in GABAergic but not cholinergic amacrine cells, and that the increases were blocked by inhibitors of nitric oxide production. The creation of nitric oxide in response to cholinergic receptor activation may provide a mechanism for modulating the well‐known mutual interactions of acetylcholine‐glycine‐GABA in the inner retina. As GABA and glycine are the primary inhibitory neurotransmitters in the retina, signaling pathways that modulate their levels or release will have major implications for the processing of complex stimuli by the retina. J. Comp. Neurol. 507:1952–1963, 2008. © 2008 Wiley‐Liss, Inc.
Stepwise Spin Transition in a Mononuclear Iron(II) Complex with Unusually Wide Plateau
Authors: Weber Birgit , Carbonera Chiara , Desplances Cedric , Létard Jean‐François 
Published: February 2008

AbstractThe reaction of the Schiff‐base like ligand H2L [L2– = (E,E)‐({diethyl 2,2′‐[1,2‐phenylenebis(iminomethylidyne)]bis(3‐oxobutanato)})] with iron(II) acetate in methanol in the presence of 4‐cyanopyridine leads to the formation of an octahedral iron(II) complex with the formula FeL(CNpy)2·0.25CNpy (1). The magnetic properties of this complex were investigated using temperature‐dependent susceptibility measurements (SQUID) and Mössbauer spectroscopy. Both measurements indicate that the complex performs a stepwise spin transition with a large plateau in the region from 225 K to 125 K and γHS ≈ 0.25. The molecule structure of the compound was determined at room temperature, 240 K (γHS ≈ 0.5 according to susceptibility measurements) and 100 K. Two complex molecules were found in the asymmetric unit with strong π–π interactions between the phenylene rings of H2L. In agreement with outcomes from the magnetic measurements, both iron centres are in the high‐spin state at room temperature and in the low‐spin state at 100 K. At 240 K one of the two iron centres is high‐spin and the other one low‐spin. The reason for the wide step with one fourth of the iron centres in the high‐spin state is the additional distorted 4‐cyanopyridine in the crystal that influences the transition temperature of the surrounding iron centres. The spin transition was followed in solution by using 1H NMR spectroscopy. A gradual spin transition with T1/2 = 238 K is obtained. Temperature‐dependent diffuse reflectivity spectra show the occurrence of photoconversion at the surface of the sample but only about 6 % of the complex could be switched in bulk condition using a SQUID magnetometer and the stability of the photoinduced HS state with TLIESST = 40 K is very weak. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Positional distribution of fatty acids in triacylglycerols and phospholipids from adzuki beans (Vigna angularis)
Authors: Yoshida Hiromi , Saiki Masayuki , Tomiyama Yuka , Mizushina Yoshiyuki 
Published: February 2008

AbstractThe fatty acid distributions of triacylglycerols (TAG) and major phospholipids (PL) obtained from adzuki beans (Vigna angularis) were investigated. The total lipids extracted from the beans were separated by thin‐layer chromatography (TLC) into eight fractions. The major lipid components were PL (63.5 wt‐%), TAG (21.2 wt‐%), steryl esters (7.5 wt‐%) and hydrocarbons (5.1 wt‐%), while free fatty acids, diacylglycerols (1,3‐DAG and 1,2‐DAG) and monoacylglycerols were also present in minor proportions (0.2–1.1 wt‐%). The major PL components isolated from the beans were phosphatidylcholine (45.3 wt‐%), phosphatidylethanolamine (25.8 wt‐%) and phosphatidylinositol (21.5 wt‐%). Phosphatidylinositol was unique in that it had the highest saturated fatty acid content among the three PL. With a few exceptions, however, the principal characteristics of the fatty acid distribution in the TAG and three PL were evident in the beans: Unsaturated fatty acids were predominantly concentrated in the sn‐2 position while saturated fatty acids primary occupied the sn‐1 or sn‐3 position in the oils of the adzuki beans. In general, these results could be useful to both consumers and producers for the manufacture of traditional adzuki foods in Japan.
Stereospecific Pseudorotation of Diastereomeric Anti‐Apicophilic Spirophosphoranes: A Novel Stereochemical Transformation Involving 10‐P‐5 Phosphoranes
Authors: Kojima Satoshi , Nakamoto Masaaki , Akiba Kin‐ya 
Published: February 2008

AbstractA diastereomeric pair of monocyclic apical H‐phosphoranes (2‐exo and 2‐exo) has been prepared from a diastereomeric pair of bicyclic equatorial H‐spirophosphoranes (1) with tBuLi. The thermal cyclization reaction of each diastereomeric apical H‐phosphorane gave rise to different diastereomeric O‐equatorial anti‐apicophilic phosphoranes (3‐exo and 3‐endo, respectively) as single products. On the other hand, the oxidation reaction of each of these apical H‐phosphoranes was complementary to the thermal reaction, affording the opposite diastereomeric anti‐apicophilic phosphorane (3‐endo and 3‐exo, respectively) as a single product. The pseudorotation of each of these diastereomeric anti‐apicophilic phosphoranes (3‐exo and 3‐endo) gave rise to different diastereomeric O‐apical phosphoranes (4‐exo and 4‐endo, respectively) as single products.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Regioselective Generation of Aryllithiums from Substituted Bromobenzenes XC6H4Br (X = 4‐Br, 4‐I, 4‐CN, 2‐CN)
Authors: Luliński Sergiusz , Serwatowski Janusz , Szczerbińska Magdalena 
Published: February 2008

AbstractSelected activated bromobenzenes XC6H4Br (X = 4‐Br, 4‐I, 4‐CN, 2‐CN) were successfully deprotonated with lithium 2,2,6,6‐tetramethylpiperidide (LTMP) in THF at –80 °C. Thus, 2,5‐dibromo‐, 2‐bromo‐5‐iodo‐, 5‐bromo‐2‐cyano‐, and 3‐bromo‐2‐cyanophenyllithium were obtained as stable intermediates and could be converted by subsequent reactions into various functionalized derivatives with good yields. A competition of directing effects of bromine versus iodine and cyano groups is discussed.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Growth‐related changes in histology and immunolocalization of steroid hormone receptors in gonads of the immature male green turtle (Chelonia mydas)
Authors: Otsuka Saori , Suzuki Masatsugu , Kamezaki Naoki , Shima Tatsuya , Wakatsuki Motoki , Kon Yasuhiro , Ohtaishi Noriyuki 
Published: February 2008

AbstractStudies on the population dynamics of sea turtles require histological evaluation of the ontogenetic development and the activity of the gonads for reproduction. To investigate the growth‐related changes of gonads in the immature male green turtle (Chelonia mydas), the histological changes of testes and epididymides and the localization of the androgen receptor, estrogen receptor α, estrogen receptor β, and progesterone receptor were examined. The testes were categorized histologically into six developmental stages, and a scarce relationship between straight carapace length and gonadal development was confirmed based on the histological analysis. Several kinds of steroid hormone receptors were examined to show distributions in both testes and epididymides, for which their immunoreactivities were enhanced according to the developmental stage of the testes. These results suggest that straight carapace length is not an adequate indicator of maturity determination, whereas histological and immunohistochemical evaluations are useful in identifying the growth stages of green turtles, owing to the higher sensitivity to steroid hormones that appear during growth. J. Exp. Zool. 309A:166–174, 2008. © 2008 Wiley‐Liss, Inc.
DFT simulations and vibrational analysis of FTIR and FT‐Raman spectra of 2‐amino‐4,6‐dihydroxypyrimidine
Authors: Krishnakumar V. , Prabavathi N. 
Published: February 2008

AbstractThis work deals with the vibrational spectroscopy of 2‐amino‐4,6‐dihydroxy pyrimidine (ADHP) by means of quantum chemical calculations. The mid‐ and far FTIR and FT‐Raman spectra were measured in the condensed state. The fundamental vibrational wavenumbers and intensity of vibrational bands were evaluated using density functional theory (DFT) with the standard B3LYP/6‐311 + G** methods and basis set combinations, and were scaled using various scale factors, which yielded good agreement between the observed and calculated wavenumbers. The vibrational spectra were interpreted with the aid of normal coordinate analysis based on the scaled density functional force field. The results of the calculations were applied to simulate the infrared and Raman spectra of the title compound, which showed excellent agreement with the observed spectra. Copyright © 2008 John Wiley & Sons, Ltd.
Non‐destructive Raman characterization of Capodimonte and Buen Retiro porcelain
Authors: Ricciardi Paola , Colomban Philippe , Milande Véronique 
Published: February 2008

AbstractA series of 18th century porcelain objects belonging to the collections of the Musée National de Céramique (Sèvres) and attributed to the manufactures of Capodimonte (Naples, Italy) and Buen Retiro (Madrid, Spain) have been characterized in the laboratory by means of Raman macro‐ and micro‐spectroscopy. Owing to their unique history, products from these two manufactures show high similarities, and therefore distinction between them is not always straightforward. Analyses have been carried out on pastes, glazes and decorations of a series of porcelain objects (cups, saucers, ornamental figures) in order to assess the compositional and technological aspects of these productions. The results are discussed in the light of previous characterization of Capodimonte and Buen Retiro porcelain fragments found during excavations in the surroundings of both manufactures. Objects from Capodimonte show a general homogeneity and are mostly comparable with the excavation samples. On the other hand, objects and fragments from Buen Retiro show varied Raman signatures in both pastes and glazes. This does not allow classifying them as a ‘reference group’ for a Raman study of this production. Copyright © 2008 John Wiley & Sons, Ltd.
A Fluorescent Chemosensor for Transition‐Metal Ions Based on Optically Active Polybinaphthyl and 2,2′‐Bipyridine
Authors: Liu Yan , Miao Qian , Zhang Shuwei , Huang Xiaobo , Zheng Lifei , Cheng Yixiang 
Published: February 2008

AbstractThe linear conjugated polymer based on the 5,5′‐positions of chiral 1,1′‐binaphthyl shows strong green‐blue fluorescence with high fluorescence quantum efficiency due to the extendedπ‐electronic structure between the chiral repeating unit and the 2,2′‐bipyridyl conjugated linker unit. Cu2+and Ni2+can form non‐radiative metal‐to‐ligand charge‐transfer complexes with the polymer, and Co2+, Mn2+, Cd2+, Zn2+, Fe2+can cause effective fluorescent quenching, which can be attributed to an energy transfer from theπ‐conjugated chiral polymer to the metal complexes. A better understanding of energy‐transfer processes in the polymers can provide information for the design of more sensitive materials.magnified image
Investigation of the dynamic stereochemistry of dimesityl‐2,4,6‐trimethoxyphenylmethane by complete lineshape analysis and 2D EXSY NMR spectroscopy
Authors: Denkova Pavletta , Vassilev Nikolay , Van Lokeren Luk , Willem Rudolph 
Published: February 2008

AbstractThe static and dynamic stereochemistry of dimesityl‐2,4,6‐trimethoxyphenylmethane in solution was investigated by lineshape analysis of 1D NMR spectra and cross‐peak amplitude processing in 2D EXSY spectra, recorded at variable temperatures. Previous studies on this propeller‐shaped chiral compound show that the stereomer threshold interconversion is associated with helicity reversal and occurs through [1,2]‐ and [1,3]‐two ring flips of one mesityl and the 2,4,6‐trimethoxyphenyl rings. In the present study, the experimental rate constants of the [1,2]‐ and [1,3]‐two ring flips, which are identical, were determined at various temperatures by combining quantitative 2D EXSY spectra processing and complete lineshape analysis (CLSA) of 1D NMR spectra. The latter were subjected to reference deconvolution and linear prediction in order to eliminate the lineshape distortions due to magnetic field inhomogeneity. The activation parameters of these ring flips were determined by an Eyring equation analysis of the temperature dependence of the rate constant. The experimentally determined activation enthalpy and entropy for the two‐ring flips, and those obtained from theoretical ab initio calculations at different levels of theory and basis sets, were found to be in good agreement. Copyright © 2008 John Wiley & Sons, Ltd.
Theoretical 13C chemical shift, 14N, and 2H quadrupole coupling‐ constant studies of hydrogen bonding in L‐alanylglycine dipeptide
Authors: Tafazzoli M. , Amini S. K. 
Published: February 2008

Abstract13C chemical shieldings and 14N and 2H electric field gradient (EFG) tensors of L‐alanylglycine (L‐alagly) dipeptide were calculated at RHF/6–31 + + G** and B3LYP/6–31 + + G** levels of theory respectively. For these calculations a crystal structure of this dipeptide obtained from X‐ray crystallography was used. Atomic coordinates of different clusters containing several L‐alagly molecules were used as input files for calculations. These clusters consist of central and surrounding L‐alagly molecules, the latter forming short, strong, hydrogen bonds with the central molecule. Since the calculations did not converge for these clusters, the surrounding L‐alagly molecules were replaced by glycine molecules. In order to improve the accuracy of calculated chemical shifts and nuclear quadrupole coupling constants (NQCCs), different geometry‐optimization strategies were applied for hydrogen nuclei. Agreement between calculated and experimental data confirms that our optimized coordinates for hydrogen nuclei are more accurate than those obtained by X‐ray diffraction. Copyright © 2008 John Wiley & Sons, Ltd.
1H,13C, 19F NMR, and ESI mass spectral characterization of two geminal difluorosteroids
Authors: Sievänen Elina , Noponen Virpi , Král Vladimír , Bříza Tomáš , Kolehmainen Erkki 
Published: February 2008

AbstractTwo geminal difluorosteroids, 3,3‐difluoro‐5β‐cholan‐24‐oic acid (1) and 3,3‐difluoro‐5α‐androstan‐17‐one (2), have been prepared from corresponding ketosteroids with diethylaminosulphurtrifluoride (DAST) treatment in moderate yields. The structures of 1 and 2 have been characterized by 1H, 13C, 19F NMR, and ESI mass spectral techniques. Copyright © 2008 John Wiley & Sons, Ltd.
Characterization of the carbides in the steel X20CrMoV12.1 used in thermal power plants
Authors: Skobir Danijela Anica , Godec Matjaz , Jenko Monika , Markoli Bostjan 
Published: February 2008

AbstractMicrostructure of the steel X20CrMoV12.1, used for thermal power plants, after tempering at approximately 500 °C consists of tempered martensite with carbide precipitates.The evolution of the chemical and phase composition of carbide precipitates in X20CrMoV12.1 steel was studied in the as‐received state after 56 000 h at 470–530 °C under load and in heat‐treated state (1–1344 h at 800 °C) using transmission electron microscopy (TEM) and electron backscatter diffraction (EBSD) technique.The precipitates found in service‐loaded state as well as in heat‐treated state were of M23C6 type. In all samples two morphologically different types of carbides were established. Copyright © 2008 John Wiley & Sons, Ltd.
Summary of ISO/TC 201 Standard: XXX. ISO 18516: 2006—Surface chemical analysis—Auger electron spectroscopy and X‐ray photoelectron spectroscopy—Determination of lateral resolution
Authors: Wolstenholme J. 
Published: February 2008

AbstractThis International Standard describes three methods for measuring the lateral resolution achievable in Auger electron spectrometers and X‐ray photoelectron spectrometers under defined settings. The straight‐edge method is suitable for instruments where the lateral resolution is expected to be larger than 1 µm. The grid method is suitable if the lateral resolution is expected to be less than 1 µm but more than 20 nm. The gold‐island method is suitable for instruments where the lateral resolution is expected to be less than 50 nm. The standard contains three informative annexes that provide illustrative examples of measurements of lateral resolution. Copyright © 2008 John Wiley & Sons, Ltd.
Preparation of SERS‐active substrates with large surface area for Raman spectral mapping and testing of their surface nanostructure
Authors: Prokopec Vadym , Cejkova Jitka , Matějka Pavel , Hasal Pavel 
Published: February 2008

AbstractSurface‐enhanced Raman scattering (SERS) is a powerful technique of Raman signal detection of substances at a low concentration level. It allows observation of structural details of films with very small thicknesses. It is possible to achieve the enhancement of Raman signal of species located on the surface of properly prepared SERS‐active substrates of up to ca 106. One of the main requirements for the substrate to be SERS‐active is the proper roughness of the surface. In this work different SERS‐active Au and Ag substrates suitable for spectral mapping were prepared using procedures which consisted of electrochemical deposition of metal layer and further roughening with oxidation–reduction cycles (ORC) treatment. The nanostructures of the metal surfaces were tested using atomic force microscopy (AFM). Monolayers formed both by covalent and noncovalent linkages to the metal surface were detected and Raman spectral maps were then measured. Roughening procedure of the substrates was optimized and its effect on the SERS enhancement was discussed. The relations among the surface nanostructure, optimal roughening, type of linkage of the analyte to the surface of the substrate and the Raman signal enhancement for the experimental conditions were studied. Copyright © 2008 John Wiley & Sons, Ltd.
Develop and nurture an international alliance capability
Authors: Mascarenhas Briance , Koza Mitchell P. 
Published: February 2008

AbstractFirms increasingly enter into alliances when expanding into international markets and market segments. Unfortunately, many of these alliances fail because managers are overconfident and unprepared for the diverse and complex contingencies they encounter. Growing research suggests that developing an alliance capability function improves alliance performance. We first identify common types of problems and opportunities that arise from alliance design to alliance dissolution. With this understanding, we then specify the alliance capabilities that must be developed to deal with these contingencies. © 2008 Wiley Periodicals, Inc.
Feeling close from a distance: Peace encounters via Internet technology
Authors: Yablon Yaacov B. 
Published: February 2008

AbstractIn regions of intractable conflicts, daily circumstances and overall reality allow very narrow opportunities to bring members of conflict groups together in order to modify their social relationships. Internet‐based communications were the backbone of a three‐month program designed to address the Jewish‐Arab conflict between Israeli Jewish youth and Arab youth to enable students to discuss issues such as equality, democracy, tolerance, and peace.