bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of urania and urania‐zirconia microspheres by a sol‐gel process
Authors: Haas P. A. , Clinton S. D. , Kleinsteuber A. T. 
Published: June 2009

AbstractThe sol‐gel process was originally developed and applied at the Oak Ridge National Laboratory for preparation of high‐density thoria‐urania fragments and microspheres for nuclear reactor fuels. The application of the process for preparation of microspheres to sols of urania, urania‐zirconia, and urania‐carbon is reported in this paper. Relatively high‐strength, spherical particles of UO2, UO2‐ZrO2, and UC2 were prepared with diameters of 50‐500 microns and densities of 80‐100% of the theoretical densities.
Reactions of Amines with Zwitterionic Quinoneimines: Synthesis of New Anionic and Zwitterionic Quinonoids
Authors: Tamboura Farba B. , Cazin Catherine S. J. , Pattacini Roberto , Braunstein Pierre 
Published: June 2009

AbstractFollowing the discovery of an unprecedented transamination reaction between primary alkylamines and a quinonoid molecule of the type [C6H2([pb2]NHCH2R)2([pb2]O)2] (1), obtained from commercially available diaminoresorcinol·2HCl, we have extended this method to the use of primary arylamines, and found that, in contrast, secondary amines led to a different outcome. Whereas functionalized molecules of type 1, which are best described as 6π + 6π zwitterions, were obtained with aniline or 4‐methoxyaniline, no transmination was observed with tBuNH2 in ethanol. In water, however, a reaction took place, but it afforded instead salt 6a, which resulted from hydrolysis of the imine group and deprotonation. Under similar conditions, secondary amines led to comparable results. The cations associated with the anionic quinonoid are readily exchanged in the presence of a primary amine. Whereas for the transamination reaction basic amines react under mild conditions, slightly harsher conditions are needed for less basic amines such as piperidine, diisopropylamine, or diethylamine. Transamination reactions were also performed with bis(methylamino) quinoneimine 4c, which is more soluble in organic solvents than 3. This led to the first examples of quinonoidal zwitterions functionalized with different alkyl groups on the nitrogen atoms. A number of compounds were characterized by X‐ray diffraction, which allowed a better understanding of their electronic situation, and in many cases, the presence of multiple hydrogen‐bond donors and acceptors results in crystal packings dominated by these interactions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Karplus‐Type Dependence of Vicinal 119Sn‐13C and 119Sn‐1H Spin‐Spin Couplings in Organotin(IV) Derivatives: A DFT Study
Authors: Casella Girolamo , Ferrante Francesco , Saielli Giacomo 
Published: June 2009

AbstractThe empirical Karplus‐type dependence of 3J(119Sn,13C) and 3J(119Sn,1H) couplings in organotin(IV) derivatives has been computationally validated by DFT methods both at the non‐relativistic and scalar ZORA relativistic level. A preliminary calibration of the computational protocols, by comparing experimental and calculated couplings for a set of suitable rigid molecules, revealed their high predictive power: in particular, relativistic results for 3J(119Sn,13C) have a mean absolute error of just above 2 Hz, over a range of values up to about 70 Hz. The latter protocol has then been used to study in detail the influence of substituents and multiple paths connecting the coupled nuclei on the vicinal coupling constants. Some conformational issues have been also considered. Significant effects have been observed and theoretical Karplus‐type curves for some representative systems have been proposed and discussed. It appears that general equations for vicinal 119Sn‐1H and 119Sn‐13C couplings cannot be derived, although the shape of the curves is preserved with |3J(0°)| < |3J(180°)| and 3J(90°) ≈ 0 Hz.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Binaphthalene‐Derived Iminium Salt Catalysts for Highly Enantioselective Asymmetric Epoxidation
Authors: Page Philip C. Bulman , Buckley Benjamin R. , Farah Mohamed M. , Blacker A. John 
Published: June 2009

AbstractEnantiomerically enriched epoxides are useful intermediates that have found many applications in asymmetric synthesis, and development of efficient catalysts for asymmetric epoxidation has received considerable attention. In this manuscript we describe the design, preparation, and use of new highly selective iminium salt organocatalysts for asymmetric epoxidation, based around a chiral binaphthalene motif coupled with a chiral substituted dioxane moiety. The new catalysts have been tested in the catalytic asymmetric epoxidation of unfunctionalized alkenes, and provide up to 95 % ee. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Chemoenzymatic Synthesis of (Protected) Psymberic Acid
Authors: Pietruszka Jörg , Simon Robert Christian 
Published: June 2009

AbstractTwo alternative approaches to the side‐chain of psymberin (1), psymberic acid (5), have been developed starting from either racemic or enantiopure acetal 6. A five‐step chemoenzymatic route provided the PMB‐protected acid (S,S)‐16 required for the coupling that should ultimately lead to the natural product 1. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Diversity in the person, diversity in the group: Challenges of identity complexity for social perception and social interaction
Authors: Bodenhausen Galen V. 
Published: June 2009

AbstractSocial psychological research is increasingly coming to grips with the complexity of social identity within the individual, both from the perspective of perceivers trying to form impressions and make judgments about multiply categorizable targets, as well as from the perspective of actors using their different self‐aspects as a framework for guiding their interactions with the social world. I review several contributions to the effort to better understand these issues and then explore some of their possible implications for understanding the nature and consequences of diversity within the group. Copyright © 2009 John Wiley & Sons, Ltd.
Renewable Ceramic (TiN) Ring Electrode in Stripping Voltammetry. Determination of Pb(II) Without Removal of Oxygen
Authors: Baś B. , Piech R. , Ziemnicka M. , Reczyński W. , Robótka M. 
Published: June 2009

AbstractCharacteristic features of the process of Pb(II) reduction and oxidation at a renewable ceramic ring electrode (RCRE) were studied by stripping voltammetry. The main constituents of the RCRE are: a specially constructed TiN ring electrode, a silver sheet used as silver counter/quasi‐reference electrode and a silicon O‐ring are fastened together in a polypropylene body. The renovation of this electrode is carried out through mechanical removal of solid contaminants and electrochemical activation in the electrolyte which fills the RCRE body. The optimal measurement conditions, composition of supporting electrolyte and procedures of the electrode activation were selected. The measurements were carried out from nondeaerated solutions. As shown on selected examples, RCRE exhibits good performance in underpotential deposition stripping voltammetry (UPD‐SV) applied for the determination of lead(II) in synthetic solutions with and without surfactants and in certified reference materials. The peak current is proportional to the concentration of lead(II) over the range 2×10−9–1×10−7 mol L−1, with a 3σ detection limit of 1×10−9 mol L−1 with an accumulation time of 30 s. The obtained results showed good reproducibility, (RSD=2–5%; n=5) and reliability.
Redox Couple of DNA on Multiwalled Carbon Nanotube Modified Electrode
Authors: Luo Hongxia , Li Shana , Guo Zhi‐Xin , He Nan , Dai Liming 
Published: June 2009

AbstractIt has been envisioned that carbon nanotubes could promote electron‐transfer reactions when used as electrode materials in electrochemical cells. In the present study, calf thymus DNA was electrochemically oxidized at an electrode modified with multiwalled carbon nanotubes. The potentials for DNA oxidation at pH 7.0 were found to be 0.71 and 0.81 V versus SCE, corresponding to the oxidation of guanine and adenine residues, respectively. An initial oxidation of adenine was observed in the first scan, which was followed by a quasi‐reversible redox process of the oxidation product in the subsequent scans.
Detection of Trace Heavy Metal Ions Using Carbon Nanotube‐ Modified Electrodes
Authors: Morton Jeffrey , Havens Nathaniel , Mugweru Amos , Wanekaya Adam K. 
Published: June 2009

AbstractA sensitive voltammetric method for detection of trace heavy metal ions using chemically modified carbon nanotubes (CNTs) electrode surfaces is described. The CNTs were covalently modified with cysteine prior to casting on electrode surfaces. Cysteine is an amino acid with high affinities towards some heavy metals. In this assay, heavy metals ions accumulated on the cysteine‐modified CNT electrode surfaces prior to being subjected to differential pulse anodic stripping voltammetry analysis. The resulting peak currents were linearly related to the concentrations of the metal ions. The method was optimized with respect to accumulation time, reduction time and reduction potential. The detection limits were found to be 1 ppb and 15 ppb for Pb2+ and Cu2+ respectively. The technique was used for the detection of Pb2+ and Cu2+ in spiked lake water. The average recoveries of Pb2+ and Cu2+ were 96.2% and 94.5% with relative standard deviations of 8.43% and 7.53% respectively. The potential for simultaneous detection of heavy metal ions by the modified CNTs was also demonstrated.
On the construction of multivariate extreme value models via copulas
Authors: Durante F. , Salvadori G. 
Published: June 2009

AbstractCopulas represent a fundamental tool for constructing multivariate probability distributions. Exploiting recent theoretical developments concerning the construction of copulas, we outline several methods for generating multivariate extreme value (MEV) laws having a suitable number of parameters, a feature of great importance in applications. The corresponding random vectors can be efficiently simulated, and easily fitted to empirical data. The use of multivariate return periods for extreme events is also discussed. A practical illustration involving maxima sampled via a network of non‐independent gauge stations is presented. Copyright © 2009 John Wiley & Sons, Ltd.
Effect of storage conditions on volatile composition of dried rosemary (Rosmarinus officinalis L.) leaves
Authors: Díaz‐Maroto M. C. , Pardo E. Alañón , Castillo‐Muñoz N. , Díaz‐Maroto I. J. , Pérez‐Coello M. S. 
Published: June 2009

AbstractThe effects of two different packaging materials for dried spices (polystyrene and glass) and storage conditions (room temperature under light and darkness) on volatile composition of dried rosemary leaves were investigated. The results showed that rosemary samples packaged in polystyrene bottles retained a higher quantity of volatile compounds than those packaged in glass bottles, independently of their storage conditions, light or darkness. However, sensorial analysis did not show statistical differences among samples in overall rosemary aroma. These results reveal that polystyrene bottles could replace the glass bottles normally used for packaging spices, a fact that could indicate a considerable saving of money for companies. Copyright © 2009 John Wiley & Sons, Ltd.
Analytical treatment on magnetohydrodynamic (MHD) flow and heat transfer due to a stretching hollow cylinder
Authors: Joneidi A. A. , Domairry G. , Babaelahi M. , Mozaffari M. 
Published: June 2009

AbstractThis paper studied on magnetohydrodynamics flow and heat transfer outside a stretching cylinder. Momentum and energy equations are reduced using similarity transformation and converted into a system of ordinary differential equations which are solved analytically by the homotopy analysis method. The effects of the parameters involved, namely the magnetic parameter (M), Prandtl number (Pr) and Reynolds number (Re) on the velocity and temperature fields are investigated.The obtained results are valid for the whole solutions' domain with high accuracy. These methods can be easily extended to other linear and nonlinear equations and so can be found widely applicable in engineering and sciences. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis and biological activity of phosphorylated compounds of 2‐substituted benzazoles
Authors: Pareek Sonu , Vyas Sushma , Seth Gita , Vyas P. C. 
Published: June 2009

AbstractA series of organophosphorus derivatives have been synthesized by the reaction of phosphorylchloride with 2‐(2′‐hydroxyphenyl)benzimidazole and 2‐(2′‐hydroxynaphthyl)benzimidazole in the presence of KHCO3 in dry THF in different molar ratios. Newly synthesized derivatives were tested for their insecticidal activity against Periplenata americana. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:246–249, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20533
Structures and vibrational spectroscopic parameters of selenoxopropanedinitrile and selenoxosilanedicarbonitrile: Theoretical study based on density functional theory method
Authors: Ramasami Ponnadurai 
Published: June 2009

AbstractThe molecular structures and vibrational spectra in harmonic and anharmonic approximations have been studied for selenoxopropanedinitrile and selenoxosilanedicarbonitrile in the gas phase. Density functional theory method with B3LYP functional and cc‐pVTZ basis set has been employed. Optimized structural parameters and spectroscopic constants, namely, anharmonic, rotational and centrifugal distortion, rotation–vibration coupling, and Coriolis coupling parameters, are reported. Infrared vibrational and Raman frequencies are provided with complete assignments to the fundamental bands, overtones, and combination tones of the molecules. This study shows that silicon for carbon substitution affects mainly those properties that are dependent on the CSe bond. The literature for these molecules is not available and therefore the data from this work would be suitable for their characterizations as and when they are synthesized. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:208–217, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20535
Indium trichloride–catalyzed synthesis of some novel 2,2′‐(N,N′‐diarylamino)‐ 4,4′‐diaryl‐5,5′‐arylidenebisthiazoles and their insecticidal activity
Authors: Gupta Ragini , Sharma Deepti , Verma Prem Singh 
Published: June 2009

AbstractA series of novel 2,2′‐(N,N′‐diarylamino)‐4,4′‐diaryl‐5,5′‐arylidene‐bisthiazoles 2 were rapidly and smoothly prepared in good yields by using non conventional techniques i.e. microwave or ultrasonic irradiation, through indium trichloride catalyzed electrophilic substitution reaction of 2‐(N‐arylamino)‐4‐arylthiazoles 1 with various arylaldehydes. All the synthesized compounds were characterized on the basis of their elemental analyses and spectral data (IR, PMR and Mass). The synthesized compounds were also evaluated for their insecticidal activity against Helicoverpa armigera and gave promising results. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:224–231, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20537
Coupled surface water–groundwater model and its application in the arid Shiyang River basin, China
Authors: Hu Li‐Tang , Wang Zhong‐Jing , Tian Wei , Zhao Jian‐Shi 
Published: June 2009

AbstractThe planning and management of water resources in the Shiyang River basin, China require a tool for assessing the impact of groundwater and stream use on water supply reliabilities and improving many environment‐related problems such as soil desertification induced by recent water‐related human activities. A coupled model, integrating rule‐based lumped surface water model and distributed three‐dimensional groundwater flow model, has been established to investigate surface water and groundwater management scenarios that may be designed to restore the deteriorated ecological environment of the downstream portion of the Shiyang River basin. More than 66% of the water level among 24 observation wells have simulation error less than 1·0 m. The overall trend of the temporal changes of simulated and observed surface runoff at the Caiqi gauging station remains almost the same. The calibration was considered satisfactory. Initial frameworks for water allocation, including agricultural water‐saving projects, water diversion within the basin and inter‐basin water transfer, reducing agricultural irrigation area and surface water use instead of groundwater exploitation at the downstream were figured out that would provide a rational use of water resources throughout the whole basin. Sixteen scenarios were modelled to find out the most appropriate management strategies. The results showed that in the two selected management options, the groundwater budget at the Minqin basin was about 1·4 × 108 m3/a and the ecological environment would be improved significantly, but the deficit existed at the Wuwei basin and the number was about 0·8 × 108 m3/a. Water demand for domestic, industry and urban green area would be met in the next 30 years, but the water shortage for meeting the demand of agricultural water use in the Shiyang River basin was about 2·2 × 108 m3/a. It is suggested that more inter‐basin water transfer should be required to obtain sustainable water resource use in the Shiyang River basin. Copyright © 2009 John Wiley & Sons, Ltd.
The effect of dentin desensitizer with different layers on thermal changes on the pulp during fabrication of provisional restoration
Authors: Gurbulak Aysegul G. , Kiliç Kerem , Zortuk Mustafa , Usumez Aslihan 
Published: June 2009

AbstractPurpose:This study investigated the effects of different desensitizers and an adhesive material application on pulpal temperature rise during direct provisional restoration polymerization.Materials and Methods:Two dentin desensitizers (Systemp, Ivoclar; BisBlock, Bisco) and a dentin adhesive (Prime Bond, Dentsply) were applied to the dentin surfaces as single layer or double layer. One autopolymerizing methacrylate (Prevision, Heraeus Kulzer) and one light polymerizing composite (Revotek LC, GC) provisional restoration materials were used in this study. A total of 160 dentin disks were prepared from extracted molars. These dentin disks were placed on an apparatus developed to measure temperature rise. After the desensitizer or dentin adhesive application, provisional materials were polymerized according to the manufacturers' instructions. The temperature increase was measured under the dentin disk with a J‐type thermocouple wire that was connected to a data logger. Differences between initial and highest temperature reading were taken, and 10 readings were averaged to determine the mean value in temperature rise. Statistical analysis was performed with three‐way analysis of variance followed by Tukey HSD test (α = 0.05).Results:Temperature rise varied according to the provisional restoration material used (composite resin, methacrylate) (p < 0.001), the agent thickness (single, double) (p < 0.001), and the agent (desensitizer, adhesive) (p < 0.001). The composite resin‐based provisional material induced higher thermal changes than methacrylate based provisional material (p < 0.01).Conclusion:The thickness of desensitizing agents affected the thermal changes; however, the desensitizers did not affect on the intrapulpal temperature although the type of provisional material used may be effective. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2009
Activation of rapid signaling pathways does not contribute to 1α,25‐dihydroxyvitamin D3‐induced growth inhibition of mouse prostate epithelial progenitor cells
Authors: Li Jia , Fleet James C. , Teegarden Dorothy 
Published: June 2009

AbstractThe active form of vitamin D, 1α,25‐dihydroxyvitamin D3 (1,25(OH)2D) inhibits the growth of prostate epithelial cells, however the underlying mechanisms have not been clearly delineated. In the current study, the impact of 1,25(OH)2D on the rapid activation of extracellular‐regulated kinase (ERK) 1/2 and protein kinase C α (PKCα), and the role of these pathways in growth inhibition was examined in immortalized mouse prostate epithelial cells, MPEC3, that exhibit stem/progenitor cell characteristics. 1,25(OH)2D treatment suppressed the growth of MPEC3 in a dose and time dependent manner (e.g., 21% reduction at three days with 100 nM 1,25(OH)2D treatment). However, ERK1/2 activity was not altered by 100 nM 1,25(OH)2D treatment for time points from 1 min to 1 h in either serum‐containing or serum‐free medium. Similarly, PKCα activation (translocation onto the plasma membrane) was not regulated by short‐term treatment of 100 nM 1,25(OH)2D. In conclusion, 1,25(OH)2D did not mediate rapid activation of ERK1/2 or PKCα in MPEC3 and therefore the growth inhibitory effect of 1,25(OH)2D is independent of rapid activation of these signaling pathways in this cell type. J. Cell. Biochem. 107: 1031–1036, 2009. © 2009 Wiley‐Liss, Inc.This article was published online 2 June 2009. An error was subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected 15 June 2009.
Novel free energy calculations to explore mechanisms and energetics of membrane protein structure and function
Authors: Im Wonpil , Lee Jinhyuk , Kim Taehoon , Rui Huan 
Published: June 2009

AbstractUnderstanding the delicate balance of forces governing helix or β‐hairpin interactions in transmembrane (TM) proteins is central to understanding membrane structure and function. These membrane constituent interactions play an essential role in determining the structure and function of membrane proteins, and protein interactions in membranes, and thus form the basis for many vital processes, including TM signaling, transport of ions and small molecules, energy transduction, and cell–cell recognition. “Why does a single‐pass TM helix or β‐hairpin have specific orientations in membranes?” “What are the roles of hydrogen bonds, close packing, and helix‐lipid or β‐hairpin‐lipid interactions in helix or β‐hairpin associations in membranes?” “How do these interactions change the membrane structures?” “How do TM domains transmit signals across membranes?” These are important membrane biophysical questions that can be addressed by understanding the delicate balance of forces governing helix or β‐hairpin interactions with/in membranes. In this work, we summarize a series of helix/β‐hairpin restraint potentials that we have developed, and illustrate their applications that begin to address the complicated energetics and molecular mechanisms of these interactions at the atomic level by calculating the potentials of mean force (PMFs) along reaction coordinates relevant to helix/β‐hairpin motions in membranes and dissecting the total PMF into the contributions arising from physically important microscopic forces. © 2009 Wiley Periodicals, Inc. J Comput Chem 2009