bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sind partikuläre Edelmetallkatalysatoren Metalle, Metalloxide oder ein Mittelding?
Authors: Goloboy James C. , Klemperer Walter G. 
Published: March 2009

AbstractGutes Modell? Partikuläre Edelmetallkatalysatoren benötigen oft kleine Mengen von Sauerstoff, um ihre optimale katalytische Aktivität auszuspielen. Die genaue Struktur und Zusammensetzung der beteiligten Metalloxidcluster ist aber bis heute, fast zweihundert Jahre nach ihrer Entdeckung, nicht geklärt. Ein neuartiges Heteropolypalladatsalz (siehe Bild; Pd gelb, O rot) bietet Einblick, wie Sauerstoffatome in kleine Edelmetallcluster eingebaut werden könnten.magnified image
Knüpfung von Thiostannat‐Sn‐Sn‐Bindungen in Lösung: In‐situ‐Bildung des gemischtvalenten funktionalisierten Komplexes [{(RSnIV)2(μ‐S)2}3SnIII2S6]
Authors: Hassanzadeh Fard Zohreh , Müller Christian , Harmening Thomas , Pöttgen Rainer , Dehnen Stefanie 
Published: March 2009

AbstractIm Tageslicht kondensiert das Doppeldecker‐artige Thiostannat [(RSnIV)4S6] (1, R=CMe2CH2COMe) zum gemischtvalenten Komplex [{(RSnIV)2(μ‐S)2}3SnIII2S6] (2, siehe Bild), der (formal) SnIII‐ neben SnIV‐Zentren enthält, wie durch Mößbauer‐Spektroskopie und DFT‐Rechnungen bestätigt wurde. 2 weist sechs funktionelle CO‐Gruppen für weitere Reaktionen an der Ligandenhülle auf, und die Bildung scheint über einen komplizierten konzertierten Mechanismus zu verlaufen.magnified image
Undulated Multicompartment Cylinders by the Controlled and Directed Stacking of Polymer Micelles with a Compartmentalized Corona
Authors: Fang Bing , Walther Andreas , Wolf Andrea , Xu Youyong , Yuan Jiayin , Müller Axel H. E. 
Published: March 2009

AbstractWie ein Bambusstab: Lange gewellte Zylinder mit der Form von Bambusstäben und festgelegten Verzweigungsstellen und Endgruppen (siehe Bild) entstehen durch reversible Stapelung von Blockterpolymer‐Micellen, die aus einem fluorierten Polybutadienkern und einer Korona mit Poly(4‐tert‐butoxystyrol)‐ und Poly(tert‐butylmethacrylat)‐Segmenten bestehen. Die Stapelung der Polymermicellen erfolgte nach dem Wechsel des Lösungsmittels von Dioxan zu Ethanol.magnified image
Phosphinoborane and Sulfidoborohydride as Chelating Ligands in Polyhydride Ruthenium Complexes: Agostic σ‐Borane versus Dihydroborate Coordination
Authors: Gloaguen Yann , Alcaraz Gilles , Pécharman Anne‐Frédérique , Clot Eric , Vendier Laure , Sabo‐Etienne Sylviane 
Published: March 2009

AbstractBindung ja, aber wie? Zwei neue Boranverbindungen wirken als difunktionelle Liganden und reagieren mit Rutheniumpolyhydriden zu zwei Arten von Komplexen (siehe Schema): Ein Produkt zeigt eine δ‐agostische Wechselwirkung der η2‐B‐H‐Bindung eines dreiwertigen Borzentrums, das andere eine Bindung als Dihydroborat‐Ligand.magnified image
Asymmetric Suzuki–Miyaura Coupling in Water with a Chiral Palladium Catalyst Supported on an Amphiphilic Resin
Authors: Uozumi Yasuhiro , Matsuura Yutaka , Arakawa Takayasu , Yamada Yoichi M. A. 
Published: March 2009

AbstractAb ins Wasser: Eine Verträglichkeit mit vielfältigen funktionellen Gruppen (FG) zeigt die Titelreaktion, die durch Kupplung von Arylhalogeniden (X=Cl, Br, I) und Arylboronsäuren mit bis zu 94 % ee zu Biarylen führt. Der chirale, auf einem amphiphilen Polystyrol‐Poly(ethylenglycol)(PS‐PEG)‐Harz fixierte Imidazoindolphosphan‐Palladium‐Katalysator ließ sich leicht zurückgewinnen.magnified image
Are Particulate Noble‐Metal Catalysts Metals, Metal Oxides, or Something In‐Between?
Authors: Goloboy James C. , Klemperer Walter G. 
Published: March 2009

AbstractA good model? Noble‐metal particulate catalysts often require small amounts of oxygen to obtain optimal activity. However, the structure and stoichiometry of the oxidized metal clusters involved remains obscure, even almost two hundred years after their discovery. A heteropolypalladate salt (see picture; Pd yellow, O red) now offers a view of how oxygen might be incorporated into small noble‐metal clusters.magnified image
Molecular Recognition in Self‐Assembled Integrated Circuits: Getting Smaller while under Control
Authors: Lim Yong‐beom , Lee Myongsoo 
Published: March 2009

AbstractAvailable in small print: Block copolymer lithography has great potential for reducing the size and fabrication time of integrated circuits. Hydrogen‐bonding‐mediated molecular recognition in self‐assembly processes can be used to produce highly ordered square arrays of block copolymers on the surface of a silicon substrate (see picture).magnified image
The Shape of Germanium Clusters To Come
Authors: Korber Nikolaus 
Published: March 2009

AbstractA different drummer: The existence of endohedral germanium clusters was predicted earlier by gas‐phase experiments. The [Co@Ge10]3− anion now synthesized is surprising, as it breaks with a long line of exclusively deltahedral structures found in the past. Instead, it has a regular pentagonal‐prismatic structure (see picture; Co gray, Ge red).magnified image
Novel dibenzocycloheptenyl phosphonium salts as thermolatent initiator in cationic polymerization
Authors: Gupta Mukesh Kumar , Singh Raj Pal 
Published: March 2009

AbstractIn this study, novel thermolatent cationic initiators based on dibenzocycloheptenyl phosphonium salts (1a, 1b, 1c, 1d, 2a, and 3a) were synthesized and their efficiency was examined in bulk polymerization of glycidyl phenyl ether (GPE). The polymerization of GPE was performed with 1 mol % of dibenzocycloheptenyl triphenylphosphonium salts (1a–1d) with different counter anions (SbF6−, PF6−, AsF6−, and BF4−) at 25–200°C for 1 h. The order of initiator activity was found as 1a > 1d > 1b > 1c. To examine the effect of phosphine moiety, the activity of 1a was compared with dibenzocycloheptenyl‐tri‐n‐butylphosphonium hexafluoroantimonate (2a). The order of initiator activity was observed as 1a > 2a. The initiator activity of 1a was compared with that of 10,11‐dihydro‐dibenzocycloheptenyltriphenylphosphonium hexafluoroantimonate (3a) to understand the effect of extended conjugation in dibenzocycloheptenyl ring. In general, with the increase in the polymerization temperature, conversion (%) also increases. The solubility of initiators in various solvents and epoxy monomers was also examined. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Nonlinear stress relaxation of silica filled solution‐polymerized styrene–butadiene rubber compounds
Authors: Sun Jin , Li Hong , Song Yihu , Zheng Qiang , He Li , Yu Jie 
Published: March 2009

AbstractThe stress relaxation of silica (SiO2) filled solution‐polymerized styrene–butadiene rubber (SSBR) has been investigated at shear strains located in the nonlinear viscoelastic regions. When the characteristic separability times are exceeded, the nonlinear shear relaxation modulus can be factorized into separate strain‐ and time‐dependent functions. Moreover, the shear strain dependence of the damping function becomes strong with an increase in the SiO2 volume fraction. On the other hand, a strain amplification factor related to nondeformable SiO2 particles can be applied to account for the local strain of the rubbery matrix. Furthermore, it is believed that the damping function is a function of the localized deformation of the rubbery matrix independent of the SiO2 content. The fact that the time–strain separability holds for both the unfilled SSBR and the filled compound indicates that the nonlinear relaxation is dominated by the rubbery matrix, and this implies that the presence of the particles can hardly qualitatively modify the dynamics of the polymer. It is thought that the filler–rubber interaction induces a coexistence of the filler network with the entanglement network of the rubbery phase, both being responsible for the nonlinear relaxation. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Microstructure and properties of epoxy foams prepared by microwave
Authors: Zhong Fachun , He Jiangping , Wang Xiaochuan 
Published: March 2009

AbstractIn this article, epoxy foams comprised of diglycidyl ether of bisphenol‐A (DGEBA) based epoxy resin E31 and E51, polyamide resin, and water were prepared by microwave irradiation method. The structure and properties of epoxy foams were analyzed by FTIR, TGA, SEM, and DMA methods. The density and compressive performance of epoxy foams was also determined. The results indicated that the epoxy foams had excellent compressive performance and the preparation of epoxy foam by microwave irradiation was high efficiency and convenient. The composition has great effect on density, foam structure, dynamical mechanic performance, and thermal degradation behavior of epoxy foams. The epoxy foam with density from 0.08 g cm−3 to 1.05 g cm−3 can be obtained by varying ratio of E51 and E31 to control the viscosity of mixtures. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Influence of the rubber blend ratio on blowout behaviors of carbon black‐reinforced natural rubber/styrene‐butadiene rubber
Authors: Choi Sung‐Seen , Kim Jong‐Chul , Ko Ji‐Eun , Cho Yi Seok , Shin Wae Gi 
Published: March 2009

AbstractBlowout behaviors of NR/SBR blend composites reinforced with carbon black were studied using a microwave oven and variation of the blowout time and temperature with the blend ratio was investigated. Morphology of the interior of the sample before exploding was observed and change of the crosslink density was measured. The blowout time became slower and the blowout temperature became higher as the SBR content of the specimen increased. The specimen with higher NR content had more cavities in the interior just before explosion. The crosslink density became lower by coming close to the blowout and crosslink density of the inner part was more reduced than that of the outer part. New organic materials were found in the burst region after blowout and they might be decomposed products of the polymer chains. The SBR specimen showed better blowout properties than the NR one. Principal sources to cause the blowout were found to be formation of the cavities in a rubber article, reduction of the crosslink density, and dissociation of the rubber chains. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and characterization of highly soluble poly(ether imide)s containing indane moieties in the main chain
Authors: Dasgupta Barnali , Sen Suman Kumar , Maji Samarendra , Chatterjee Shyambo , Banerjee Susanta 
Published: March 2009

AbstractA new indane containing unsymmetrical diamine monomer (3) was synthesized. This diamine monomer leads to a number of novel semifluorinated poly (ether imide)s when reacted with different commercially available dianhydrides like benzene‐1,2,4,5‐tetracarboxylic dianhydride (PMDA), benzophenone‐3,3′, 4,4′‐tetracarboxylic dianhydride (BTDA), 4,4′‐(hexafluoro‐isopropylidene)diphthalic anhydride (6FDA), 4,4′‐oxydiphthalic anhydride (ODPA), and 4,4′‐(4,4′‐Isopropylidenediphenoxy)bis(phthalic anhydride) (BPADA) by thermal imidization route. All the poly(ether imide)s showed excellent solubility in several organic solvents such as N‐methylpyrrolidone (NMP), N,N‐dimethylformamide (DMF), N,N‐dimethylacetamide (DMAc), tetrahydrofuran (THF), chloroform (CHCl3) and dichloromethane (DCM) at room temperature. These light yellow poly (ether imide)s showed very low water absorption (0.19–0.30%) and very good optical transparency. Wide angle X‐ray diffraction measurements revealed that these polymers were amorphous in nature. The polymers exhibited high thermal stability up to 526°C in nitrogen with 5% weight loss, and high glass transition temperature up to 265°C. The polymers exhibited high tensile strength up to 85 MPa, modulus up to 2.5 GPa and elongation at break up to 38%, depending on the exact polymer structure. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and properties of novel polyurethane‐urea insulating coatings from hydroxyl‐terminated prepolymers and blocked isocyanate curing agent
Authors: Moeini Hamid Reza 
Published: March 2009

AbstractA novel series of one‐pack solvent borne polyurethane‐urea insulating coatings was prepared from hydroxyl‐terminated prepolymers (HTP) and blocked isocyanate curing agent (BIC). HTP was prepared from poly z(tetramethylene ether)glycol (PTMEG) with excess amount of toluene diisocyanate (TDI) and subsequent reaction of NCO‐terminated polyurethane with tris(hydroxymethyl‐aminomethane) (TRIS). BIC was prepared from the reaction of trimethylol propane, TDI, and N‐methyl aniline. HTP, BIC, and final products were characterized by conventional methods, and the curing condition was optimized via gel content measurements. Crosslink density of samples was determined via equilibrium swelling method, using Flory‐Rehner equations. Thermal, mechanical, and electrical properties as well as the chemical resistance of prepared coatings were evaluated and compared with commercially available formulations. Effects of structural parameters on physical, electrical, mechanical, and dynamic mechanical (DMTA) properties of the polyurethane‐urea coatings were investigated. The investigation of results showed superior electrical and mechanical properties of prepared green coating as a tailor‐made electrical insulator for metals. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Characterizing Web users' degree of Web 2.0‐ness
Authors: Chiang I‐Ping , Huang Chun‐Yao , Huang Chien‐Wen 
Published: March 2009

AbstractThough practitioners have seen discussions and debates surrounding the “Web 2.0” concept for the last few years, we know little of Web users' heterogeneity in the usage of Web 2.0 applications, let alone the factors associated with such heterogeneity. In this article, we propose a Web user's degree of Web 2.0‐ness to be measured by the weighted average of the degrees of Web 2.0‐ness of the Web sites that he or she has visited. A Web site's degree of Web 2.0‐ness in turn is evaluated through a series of binary criteria as to whether the site accommodates popular Web 2.0 applications. Utilizing clickstream data from an online panel coupled with expert scoring for the empirical analysis, we find that a Web user's degree of Web 2.0‐ness is positively associated with his or her behavioral volume (measured by the number of page views), behavioral speed (measured by the duration of each page view), and behavioral concentration (measured by the Gini coefficient of page views the user made across Web sites). Furthermore, Web users who are younger and male are found to have a higher degree of Web 2.0‐ness.
Comparing cortisol, stress, and sensory sensitivity in children with autism
Authors: Corbett Blythe A. , Schupp Clayton W. , Levine Seymour , Mendoza Sally 
Published: March 2009

AbstractPreviously we reported that children with autism show significant variability in cortisol. The current investigation was designed to extend these findings by exploring plausible relationships between cortisol and psychological measures of stress and sensory functioning. Salivary cortisol values for diurnal rhythms and response to stress in children with and without autism were compared to parent‐report measures of child stress, the Stress Survey Schedule (SSS), sensory functioning, Short Sensory Profile (SSP), and Parenting Stress Index. In autism, a negative relationship between morning cortisol and the SSS revealed that higher observed symptoms of stress were related to lower cortisol. Lower cortisol is seen in conditions of chronic stress and in social situations characterized by unstable social relationships. Sensory sensitivity painted a more complicated picture, in that some aspects of SSP were associated with higher while others were associated with lower cortisol. We propose that increased sensory sensitivity may enhance the autistic child's susceptibility to the influence of zeitgeibers reflected in variable cortisol secretion. Evening cortisol was positively associated with SSS such that the higher the level of evening cortisol, the higher the child's parent‐reported daily stress, especially to changes, such as in daily routine. Regarding the response to stress, the psychological and parent variables did not differentiate the groups; rather, discrete subgroups of cortisol responders and nonresponders were revealed in both the autism and neurotypical children. The results support a complex interplay between physiological and behavioral stress and sensory sensitivity in autism and plausible developmental factors influencing stress reactivity across the groups.
Ignorance or integration: the cognitive processes underlying choice behavior
Authors: Ayal Shahar , Hochman Guy 
Published: March 2009

AbstractThe fast‐and‐frugal heuristic framework assumes noncompensatory tools for human preferences (i.e., priority heuristic) and inferences (i.e., take the best heuristic). According to this framework, these heuristics predict choice behavior as well as model the cognitive processes underlying such behavior. The current paper presents two studies that juxtapose predictions derived from these two simple heuristics with alternative predictions derived from compensatory principles. Dependent measures that included reaction time, choice pattern, confidence level, and accuracy were better predicted by compensatory indices than by noncompensatory indices. These findings suggest that people do not rely on limited arguments only, but tend to integrate all acquired information into their choice processes. This tendency was replicated even when the experimental task facilitated the use of noncompensatory principles. We argue that the fast and frugal heuristics can predict the final outcome only under certain conditions, but even in these particular situations they are not applicable to the processes underlying choice behavior. An integrative model for choice behavior is proposed that better represents the data. Copyright © 2009 John Wiley & Sons, Ltd.
The effects of Scutellaria baicalensis extract on embryonic development in mice
Authors: Tian Xiao Ying , Cheung Lok Man , Leung Kevin , Qi Chen , Deng Bin , Deng Ping Xiang , Xu Min 
Published: March 2009

AbstractBACKGROUND: Scutellaria baicalensis is a perennial herbaceous plant widely distributed in Oriental areas. Its roots, a commonly used medicinal source, reputedly calm fetuses in pregnant women; however, there is no sufficient evidence to date to assess its safety during pregnancy. This study aims to evaluate the effects of S. baicalensis aqueous extract on embryonic development in ICR mice. METHODS: Aqueous extract of S. baicalensis roots was prepared in accordance with clinical application. Pregnant mice were randomly divided into four groups, i.e., mice treated by gavage with water as negative control, with aqueous extract of 2 (1.8 times of human daily dose), 8 or 32 g/kg/day from gestation day (Gd) 6 to 15 as low‐, middle‐, and high‐dose groups, respectively. The parameters of live and dead fetuses, resorptions, external and skeletal malformed fetuses, maternal body weight, maternal liver, kidneys, and heart weights were evaluated on Gd 18. RESULTS: There was no significant difference in fetal parameters among four groups. Maternal absolute liver and kidneys weights in the high‐dose group were significantly higher than those in negative control (p<0.05). Relative liver and kidneys weights in this group were significantly higher than those in any other group (p<0.05). CONCLUSIONS: Oral administration of aqueous extract of S. baicalensis roots at or below 32 g/kg/day to ICR mice during organogenesis did not cause significant fetal external or skeletal malformations. However, 32 g/kg/day presented potential maternal toxicity. Birth Defects Res (Part B)86: 79‐84, 2009. © 2009 Wiley‐Liss, Inc.
Postnatal development in cynomolgus monkeys following prenatal exposure to natalizumab, an α4 integrin inhibitor
Authors: Wehner Nancy G. , Shopp George , Osterburg Ingrid , Fuchs Antje , Buse Eberhard , Clarke Janet 
Published: March 2009

AbstractBACKGROUND: Natalizumab is a humanized monoclonal IgG4 antibody to human α4 integrin that blocks the interaction of α4β1 and α4β7 integrins with their ligands, including fibronectin, vascular cell adhesion molecule‐1, and mucosal addressin cellular adhesion molecule‐1. Because α4 integrins and their ligands are widely involved in mammalian development, lymphopoeisis, and hematopoiesis, natalizumab may interfere with these processes. METHODS: The effects of prenatal exposure to natalizumab on postnatal development were assessed in cynomolgus monkeys at doses of 0 and 30 mg/kg administered intravenously every other day from gestational day (GD) 20 to 70 or GD 20 to term. Infants were delivered by natural birth and evaluated for general health, survival, development, and immunological structure and function at 12 or 18 months. RESULTS: An increase in abortions was seen in the first cohort of natalizumab‐treated dams (39.3 vs. 7.1% in the controls) but not in the second cohort (33.3, 37.5%). Infants in the term treatment group had elevated lymphocyte (∼150%) and nucleated red blood cell counts (∼400%), consistent with the pharmacological effect of natalizumab, and reductions in platelet counts (∼28%), which were reversible following clearance of natalizumab. No anemia was observed. Infants in the term treatment group had significantly increased spleen weights at 12 months but not at 18 months. All other experimental observations in infants from natalizumab‐treated dams were comparable with those of controls. CONCLUSION: Natalizumab had no adverse effects on the general health, survival, development, or immunological structure and function of infants born to dams treated with natalizumab during pregnancy. Birth Defects Res (Part B) 86: 144‐156, 2009. © 2009 Wiley‐Liss, Inc.
Vitagenes, cellular stress response, and acetylcarnitine: Relevance to hormesis
Authors: Calabrese Vittorio , Cornelius Carolin , Dinkova‐Kostova Albena T. , Calabrese Edward J. 
Published: March 2009

AbstractModulation of endogenous cellular defense mechanisms via the stress response signaling represents an innovative approach to therapeutic intervention in diseases causing chronic damage, such as neurodegeneration and cancer. Protein thiols play a key role in redox sensing, and regulation of cellular redox state is crucial mediator of multiple metabolic, signaling, and transcriptional processes. Maintenance of optimal long‐term health conditions is accomplished by a complex network of longevity assurance processes that are controlled by vitagenes, a group of genes involved in preserving cellular homeostasis during stressful conditions. Vitagenes encode for heat shock proteins (Hsp) Hsp32, Hsp70, the thioredoxin, and the sirtuin protein systems. Dietary antioxidants, such as polyphenols and L‐carnitine/acetyl‐L‐carnitine, have recently been demonstrated to be neuroprotective through the activation of hormetic pathways, including vitagenes. The hormetic dose‐response, challenges long‐standing beliefs about the nature of the dose‐response in a low dose zone, having the potential to affect significantly the design of pre‐clinical studies and clinical trials as well as strategies for optimal patient dosing in the treatment of numerous diseases. Given the broad cytoprotective properties of the heat shock response, there is now strong interest in discovering and developing pharmacological agents capable of inducing these responses. In this review we discuss the most current and up‐to‐date understanding of the possible signaling mechanisms by which acetylcarnitine by activating vitagenes can differentially modulate signal transduction cascades inducing apoptosis/cell death in abnormal cancer cells but at the same time enhancing defensive enzymes to protect against carcinogenesis and neurodegeneration in normal cells. © 2009 International Union of Biochemistry and Molecular Biology, Inc.