bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spin‐Polarized Structures and Solid‐State NMR Spectroscopy of Paramagnetic Compounds
Authors: Schmedt auf der Günne Jörn 
Published: March 2009

AbstractOn an atomic scale and with high sensitivity, solid‐state NMR spectroscopy can provide information about the electronic spin density and coupling mechanisms in paramagnetic compounds. The picture shows how the hyperfine splitting collapses through relaxation. Insights into which compounds are suitable and which approximations have to be made are given.magnified image
Synthesis of new phase transfer‐catalyzed free radical polymerization of ethyl methacrylate: A kinetic study
Authors: Sivapitchai Savitha , Umapathy M. J. 
Published: March 2009

AbstractIn this study, a new phase transfer catalyst has been synthesized and characterized, which is used for the study of kinetics and mechanism of the free radical polymerization of ethyl methacrylate. The reactions were carried out using peroxodisulfate as initiator in inert and unstirred condition at 60°C ± 1°C. The order with respect to monomer, initiator, and catalyst were found to be 1, 0.7, and 0.5, respectively. The rate of polymerization is independent of ionic strength and pH. Based on the results obtained, a mechanism has been proposed for the polymerization reactions. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Viscoelastic behavior and submolecular level dynamic heterogeneity of hydrogen‐bonded polymer blends probed by dynamic FTIR spectroscopy
Authors: Huang He , Liu Qiong , Sun Tai , Chen Jun , Guo Wenjuan 
Published: March 2009

AbstractViscoelastic behavior and submolecular (functional group) level dynamic heterogeneity of hydrogen‐bonded poly(vinyl phenol)/poly(methyl acrylate) (PVPh/PMA) blends were investigated by using dynamic FTIR spectroscopy. It has been found that the viscoelastic behaviors of the blends, measured by the dynamic (in‐phase and quadrature) spectra of both “free” and hydrogen‐bonded carbonyl groups are dependent on the compositions, i.e., the Tg of the blends, and the degree of hydrogen bonding between the two components. In all the blends studied, elastic response of the hydrogen‐bonded carbonyl groups to the applied strain has been found. The free carbonyl groups respond differently to the applied strain in these blends. Essentially, elastic response of the free carbonyl groups to the applied strain is observed in blends with both a high Tg and a higher fraction (∼ 40%) of intermolecular hydrogen bonding between PVPh and PMA, and the submolecular level dynamic heterogeneity is suppressed. The free carbonyl group has a viscous component to its response, in blends having a lower fraction (∼ 20%) of hydrogen bonds, even at temperatures well below the thermal Tg of the blends, suggesting that there is a degree of submolecular level dynamic heterogeneity in these blends. Almost entirely viscous response of the free carbonyl group is found in blends whose Tg is close to room temperature and fraction of PVPh/PMA hydrogen bonds is very low. The results reported here suggest that dynamic FTIR has considerable potential for studying specific interactions and viscoelastic behaviors in hydrogen‐bonded polymer blends on submolecular level. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Trade‐off between immune stimulation and expression of storage protein genes
Authors: Lourenço Anete P. , Martins Juliana R. , Bitondi Márcia M.G. , Simões Zilá L.P. 
Published: March 2009

AbstractProteins stored in insect hemolymph may serve as a source of amino acids and energy for metabolism and development. The expression of the main storage proteins was assessed in bacterial‐challenged honey bees using real‐time (RT)‐PCR and Western blot. After ensuring that the immune system had been activated by measuring the ensuing expression of the innate immune response genes, defensin‐1 (def‐1) and prophenoloxidase (proPO), we verified the expression of four genes encoding storage proteins. The levels of vitellogenin (vg) mRNA and of the respective protein were significantly lowered in bees injected with bacteria or water only (injury). An equivalent response was observed in orally‐infected bees. The levels of apolipophorin II/I (apoLp‐II/I) and hexamerin (hex 70a) mRNAs did not significantly change, but levels of Hex 70a protein subunit showed a substantial decay after bacterial challenge or injury. Infection also caused a strong reduction in the levels of apoLp‐III transcripts. Our findings are consistent with a down‐regulation of the expression and accumulation of storage proteins as a consequence of activation of the immune system, suggesting that this phenomenon represents a strategy to redirect resources to combat injury or infection. © 2009 Wiley Periodicals, Inc.
Validation of psychometric research instruments: The case of information science
Authors: Kim Yong‐Mi 
Published: March 2009

AbstractInstrument validation is a critical step that researchers should employ in order to ensure the generation of scientifically valid knowledge. Without it, the basis of research findings and the generalization of such are threatened. This is especially true in the social sciences, a discipline in which the majority of published articles utilize subjective instruments in the collection of data. Consequently, instrument validation has increasingly become common practice in the social sciences, yet implementation of this practice differs greatly among the social‐science disciplines. The assessment of instrument validation undertaken in this study attempts to provide guidance for reviewers, editors, authors, and readers, by offering various techniques of validity and analyzing the quality of a set of psychometric journal articles. In this research, six attributes of instrument validation areas are identified as validation protocol. The Journal of the American Society for Information Science and Technology (JASIST), which is widely recognized as a leading journal in the field of information science, was selected for examination to determine how well a set of research articles ranked in meeting instrument‐validation protocol. Findings show that while researchers are becoming increasingly attentive to certain validation issues, standards on validation processes and reporting might prove helpful. This paper identifies areas for improvement in the reporting of validity measures and offers ways for researchers to implement them.
Resistance to change and the adoption of digital libraries: An integrative model
Authors: Nov Oded , Ye Chen 
Published: March 2009

AbstractIn this paper we extend earlier work on the role of the personality trait of resistance to change (RTC) in the adoption of digital libraries. We present an integrative study, drawing on a number of research streams, including IT adoption, social psychology, and digital‐library acceptance. Using structural equation modeling, we confirm RTC as a direct antecedent of effort expectancy. In addition, we also find that by affecting computer anxiety and result demonstrability, RTC acts as an indirect antecedent to both effort expectancy and performance expectancy, which in turn determine user intention to adopt digital library technology. Implications for research and practice are discussed.
Radiation from mobile phone systems: Is it perceived as a threat to people's health?
Authors: Kristiansen Ivar S. , Elstein Arthur S. , Gyrd‐Hansen Dorte , Kildemoes Helle W. , Nielsen Jesper B. 
Published: March 2009

AbstractThe aim of this study was to explore the prevalence, nature and determinants of concerns about mobile phone radiation. We used data from a 2006 telephone survey of 1004 people aged 15+ years in Denmark. Twenty‐eight percent of the respondents were concerned about exposure to mobile phone radiation; radiation from masts was of concern to about 15%. In contrast, 82% were concerned about pollution. Nearly half of the respondents considered the mortality risk of 3G phones and masts to be of the same order of magnitude as being struck by lightning (0.1 fatalities per million people per year) while 7% thought it was equivalent to tobacco‐induced lung cancer (∼500 fatalities per million per year). Among women, concerns about mobile phone radiation were positively associated with educational attainment, perceived mobile phone mortality risk and concerns about unknown consequences of new technologies. More than two thirds of the respondents felt that they had received inadequate public information about the 3G system. The results of the study indicate that the majority of the population has little concern about mobile phone radiation while a small minority is very concerned. Bioelectromagnetics 30:393–401, 2009. © 2009 Wiley‐Liss, Inc.
Bacterial Alarmone, Guanosine 5′‐Diphosphate 3′‐Diphosphate (ppGpp), Predominantly Binds the β′ Subunit of Plastid‐Encoded Plastid RNA Polymerase in Chloroplasts
Authors: Sato Michio , Takahashi Kosaku , Ochiai Yuka , Hosaka Takeshi , Ochi Kozo , Nabeta Kensuke 
Published: March 2009

AbstractIt's alarming: Bacterial alarmone guanosine 5′‐diphosphate 3′‐diphosphate (ppGpp), which is a key regulatory molecule that controls the stringent response, also exists in chloroplasts of plant cells. Cross‐linking experiments with 6‐thioguanosine 5′‐diphosphate 3′‐diphosphate (6‐thioppGpp) and chloroplast RNA polymerase indicate that ppGpp binds the β′ subunit of plastid‐encoded plastid RNA polymerase that corresponds to the Escherichia coli β′ subunit.magnified imageChloroplasts, which are thought to have originated from cyanobacteria, have their own genetic system that is similar to that of the bacteria from which they were derived. Recently, bacterial alarmone guanosine 5′‐diphosphate 3′‐diphosphate (ppGpp, 1), a key regulatory molecule that controls the stringent response, was identified in the chloroplasts of plant cells. Similar to its function in bacteria, ppGpp inhibits chloroplast RNA polymerase; this suggests that ppGpp mediates gene expression through the stringent response in chloroplasts. However, a detailed mechanism of ppGpp action in chloroplasts remains elusive. We synthesized 6‐thioguanosine 5′‐diphosphate 3′‐diphosphate (6‐thioppGpp) as a photoaffinity probe of ppGpp; this probe thus enabled the investigation of ppGpp binding to chloroplast RNA polymerase. We found that 6‐thioppGpp, as well as ppGpp, inhibits chloroplast RNA synthesis in vitro in a dose‐dependent manner. Cross‐linking experiments with 6‐thioppGpp and chloroplast RNA polymerase indicated that ppGpp binds the β′ subunit (corresponding to the Escherichia coli β′ subunit) of plastid‐encoded plastid RNA polymerase composed of α, β, β′, β′′, and σ subunits. Furthermore, ppGpp did not inhibit transcription in plastid nucleoids prepared from tobacco BY‐2 cells; this suggests that ppGpp does not inhibit nuclear‐encoded plastid RNA polymerase.
Rational Biosynthetic Engineering for Optimization of Geldanamycin Analogues
Authors: Kim Woncheol , Lee Dongho , Hong Seong Su , Na Zhu , Shin Jin Chul , Roh Su Heun , Wu Cheng‐Zhu , Choi Oksik , Lee Kyeong , Shen Yue‐Mao , Paik Sang‐Gi , Lee Jung Joon , Hong Young‐Soo 
Published: March 2009

AbstractTailor made: We report the rational biosynthesis of C15 hydroxylated non‐quinone geldanamycin analogues by site‐directed mutagenesis of the geldanamycin polyketide synthase (PKS), together with a combination of post‐PKS tailoring genes. Rational biosynthetic engineering allowed the generation of geldanamycin derivatives, such as DHQ3 illustrated in the figure, which had superior pharmacological properties in comparison to the parent compound.magnified imageA rational biosynthetic engineering approach was applied to the optimization of the pharmacological properties of the benzoquinone ansamycin, geldanamycin. Geldanamycin and its natural or semisynthetic derivatives have the potential to serve as anticancer chemotherapeutic agents. However, these first‐generation Hsp90 inhibitors share an unfavorable structural feature that causes both reduced efficacy and toxicity during clinical evaluation. We report the rationally designed biosynthesis of C15 hydroxylated non‐quinone geldanamycin analogues by site‐directed mutagenesis of the geldanamycin polyketide synthase (PKS), together with a combination of post‐PKS tailoring genes. A 15‐hydroxyl‐17‐demethoxy non‐quinone analogue, DHQ3, exhibited stronger inhibition of Hsp90 ATPase activity (4.6‐fold) than geldanamycin. Taken together, the results of the present study indicate that rational biosynthetic engineering allows the generation of derivatives of geldanamycin with superior pharmacological properties.
Photocrosslinking of RNA and PhotoMet‐Containing Amphiphilic α‐Helical Peptides
Authors: Hyun Soonsil , Han Areum , Yu Jaehoon 
Published: March 2009

AbstractDiscovering RNA–protein interactions: A library of photoMet‐containing peptides was synthesized by using an Arg‐ and Leu‐rich α‐helical amphiphilic peptide. Irradiation of mixtures of these peptides and Rev‐responsive element (RRE) hairpin RNA promoted formation of covalent adducts. Analysis of one adduct showed that U26 in the bulged stem is responsible for covalent bond formation with the carbene intermediate. This strategy can provide important structural information about RNA–peptide interactions.magnified image
Nanostructured Copper Oxide on Silica–Zirconia Mixed Oxides by Chemical Implantation
Authors: Dell'Amico Daniela Belli , Bertagnolli Helmut , Calderazzo Fausto , D'Arienzo Massimiliano , Gross Silvia , Labella Luca , Rancan Marzio , Scotti Roberto , Smarsly Bernd M. , Supplit Ralf , Tondello Eugenio , Wendel Eric 
Published: March 2009

AbstractA new route to chemical implantation of copper(II) N,N‐dialkylcarbamato complexes on silica and nanostructured silica–zirconia matrices and subsequent thermal treatment (see scheme) is an efficient method of functionalizing the oxide matrices with nanostructured CuO. The materials have been characterized thoroughly and the effect of selected experimental parameters on the grafting reaction was investigated. magnified imageN,N‐Dialkylcarbamato complexes of copper(II), [Cu(O2CNR2)2] (R=All=allyl, C3H5; iPr, CH(CH3)2) were prepared with the aim of functionalizing silica and nanostructured silica–zirconia matrices. The mixed matrices for the grafting reactions were prepared by copolymerizing MAPTMS (methacryloxypropyltrimethoxysilane), the precursor for the silica matrix, with the zirconium tetranuclear derivative [Zr4O2(OMc)12] (OMc=methacrylate), the precursor for the zirconia nanoparticles. Suspension of the silica and silica–zirconia matrices in a solution of the copper dialkylcarbamate led to the functionalization of the respective substrates. The composition, microstructure, morphology, and physicochemical nature of the copper species grafted on the matrices were investigated by FTIR, X‐ray photoelectron spectroscopy (XPS), EPR, X‐ray absorption spectroscopy (XAS), XRD, TEM, and dinitrogen adsorption. The effect of selected experimental parameters (the nature of the copper precursor and of the matrix, grafting time, thermal treatment) on the grafting reaction was investigated. The Cu/Si ratio is increased by increasing the grafting time and the ZrO2–SiO2 matrix is more reactive to attack by the carbamato complexes than either prepared or commercial SiO2. After functionalization of the matrix, thermal treatment yielded nanostructured copper(II) oxide clusters, average diameter 12–15 nm, uniformly supported on the silica and on the silica–zirconia matrices.
Ground‐ and Excited‐State Tautomerization Rates in Porphycenes
Authors: Fita P. , Urbańska N. , Radzewicz C. , Waluk J. 
Published: March 2009

AbstractReaction rates from polarized spectroscopy: A new method based on ultrafast pump–probe polarization spectroscopy enables the measurement of the ground‐ and excited‐state reaction rates for self‐exchange processes. The technique was used to study double hydrogen transfer in porphycene and its derivatives (see figure).magnified imageThe rates of double hydrogen transfer in the ground and excited electronic states have been measured for porphycene and its derivatives by using a new method based on pump–probe polarization spectroscopy. Changing the strength of two intramolecular hydrogen bonds by altering the NH⋅⋅⋅N distance leads to differences in the tautomerization rate exceeding three orders of magnitude. The reaction is considerably slower in the lowest electronically excited state. A correlation was found between the tautomerization rates and 1H chemical shifts of the internal protons.
ChemInform Abstract: Chemical Bonding and Electronic and Magnetic Structure in LaOFeAs.
Authors: Wojdel Jacek C. , de P. R. Moreira Iberio , Illas Francesc 
Published: March 2009

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: Luminescence in KCl:Eu2+, Tl+ X‐Ray Storage Phosphors.
Authors: Nagarajan S. , Sudarkodi R. 
Published: March 2009

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: Halide‐Stabilized LiBH4, a Room‐Temperature Lithium Fast‐Ion Conductor.
Authors: Maekawa Hideki , Matsuo Motoaki , Takamura Hitoshi , Ando Mariko , Noda Yasuto , Karahashi Taiki , Orimo Shin‐ichi 
Published: March 2009

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: Synthesis and Properties of LnRu2P2 (Ln = Lanthanides) Crystals.
Authors: Mizusaki S. , Adachi Y. , Ohnishi T. , Taniguchi T. , Nagata Y. , Ozawa T. C. , Noro Y. , Samata H. 
Published: March 2009

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: Complementary Active Sites Cause Size‐Selective Reactivity of Aluminum Cluster Anions with Water.
Authors: Roach Patrick J. , Woodward W. Hunter , Castleman A. W. Jr. , Reber Arthur C. , Khanna Shiv N. 
Published: March 2009

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: Solid Sodium Borohydride as a Hydrogen Source for Fuel Cells.
Authors: Liu Bin Hong , Li Zhou Peng , Suda S. 
Published: March 2009

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: Catalytically Enhanced Dehydrogenation of Li—Mg—N—H Hydrogen Storage Material by Transition Metal Nitrides.
Authors: Ma Lai‐Peng , Wang Ping , Dai Hong‐Bin , Cheng Hui‐Ming 
Published: March 2009

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 Electronic Behavior of V2O3/TiO2/Carbon Clusters Composite Materials Obtained by the Calcination of a V(acac)3/TiO(acac)2/Polyacrylic Acid Complex.
Authors: Matsui H. , Okajima T. , Karuppuchamy S. , Yoshihara M. 
Published: March 2009

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: Synthesis of Nanocrystalline Li4Ti5O12 by a Novel Aqueous Combustion Technique.
Authors: Raja M. W. , Mahanty S. , Kundu M. , Basu R. N. 
Published: March 2009

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: A Simple Inorganic‐Solvent‐Thermal Route to Nanocrystalline Niobium Diboride.
Authors: Ma Jianhua , et al. et al. 
Published: March 2009

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: Preparation of the Binary Technetium Bromides: TcBr3 and TcBr4.
Authors: Poineau Frederic , Rodriguez Efrain E. , Forster Paul M. , Sattelberger Alfred P. , Cheetham Anthony K. , Czerwinski Kenneth R. 
Published: March 2009

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: New Hydrogen Peroxide Adducts of Alkali Metal Tetracyanoplatinates A2[Pt(CN)4]·H2O2 (A: K, Rb, Cs).
Authors: Muehle Claus , Peters Eva‐Maria , Jansen Martin 
Published: March 2009

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 Deracemization of Secondary Alcohols via a Chemo‐Enzymatic Process.
Authors: Wu Xiaomei , Xin Jiaying , Zhu Limin , Branford‐white Chris , Sun Wei , Xu Jianhe , Xia Chungu 
Published: March 2009

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: Chemoselective Conjugate Addition of Dimethylzinc‐Mediated Ether and Acetal Radicals to Alkylidenemalonates and Asymmetric Reactions.
Authors: Yamada Ken‐ichi , Maekawa Masaru , Akindele Tito , Nakano Mayu , Yamamoto Yasutomo , Tomioka Kiyoshi 
Published: March 2009

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.