bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnetic and Stable H3PW12O40‐Based Core@shell Nanomaterial towards the Esterification of Oleic Acid with Methanol
Authors: Li Shi , Zhai Shang‐Ru , Zhang Jian‐Ming , Xiao Zuo‐Yi , An Qing‐Da , Li Ming‐Hui , Song Xiao‐Wei 
Published: October 2013

AbstractA magnetically retrievable and stable composite, Fe3O4@SiO2–NH2/HPW@CS/HPW, in which H3PW12O40 (abbreviated as HPW hereafter) was successfully anchored onto the surface of a cross‐linked chitosan coating on magnetic Fe3O4 cores, has been prepared by means of chemical bonding between the amino and HPW components. The resultant composites were characterized by different physicochemical techniques, such as TEM, SEM, FTIR, and vibrating sample magnetometry (VSM). An improved synthesis of methyl oleate from oleic acid and methanol was observed with the as‐prepared material as catalyst with easy recovery by simply using an external magnet. A yield of 93.2 % of methyl oleate was achieved under the optimal reaction conditions, that is, a 20:1 molar ratio of methanol to oleic acid and 0.4 g catalyst at 60 °C for 4 h. It was demonstrated that improved catalytic performance and facilitated separation were simultaneously achieved in the esterification reactions as a result of the core@shell structures in which stabilized HPW and magnetic cores are integrated into one body.
Stability and Reactivity of Cyclometallated Naphthylamine Complexes in Pd–C Bond Insertion Reactions with Coordinated Alkynylphosphanes
Authors: Chen Shuli , Chiew Jun Xuan , Pullarkat Sumod A. , Li Yongxin , Leung Pak‐Hing 
Published: October 2013

AbstractPhenylbis(phenylethynyl)phosphane PhP(C≡CPh)2 coordinates regiospecifically to the α‐methyl‐chiral ortho‐platinated and ‐palladated naphthylamine units at the positions trans to the nitrogen donors. The P→Pt coordination bond is kinetically inert, whereas the P→Pd bond is labile. Upon heating of these phosphane complexes at 70 °C, one of the C≡C bonds in the coordinated PhP(C≡CPh)2 was activated towards an intermolecular Pd–C bond insertion reaction with an external ortho‐palladated naphthylamine ring. No intramolecular insertion reaction occurred. In contrast to its palladium analogue, the ortho‐platinated ring is not reactive towards coordinated PhP(C≡CPh)2, although it can promote the Pd–C bond insertion reaction. However, despite the high kinetic stability of the P→Pt coordination, the organoplatinum unit is a noticeably weaker activator than its organopalladium counterpart. The chirality of the reacting ortho‐metallated naphthylamine ligand exhibited high stereochemical influence on the formation of the new stereogenic phosphorus center during the course of these C–C bond‐formation reactions. The coordination chemistry and the absolute stereochemistry of the dimetallic products were determined by single‐crystal X‐ray crystallographic analysis.
Binuclear Cage‐Like Copper(II) Silsesquioxane (“Cooling Tower”) – Its High Catalytic Activity in the Oxidation of Benzene and Alcohols
Authors: Bilyachenko Alexey N. , Dronova Marina S. , Yalymov Alexey I. , Korlyukov Alexander A. , Shul'pina Lidia S. , Arkhipov Dmitry E. , Shubina Elena S. , Levitsky Mikhail M. , Kirilin Alexey D. , Shul'pin Georgiy B. 
Published: October 2013

AbstractA new method of metallasilsesquioxane synthesis is described for the first time. According to this method, a partial nucleophilic cleavage of polymeric copper phenylsilsesquioxane by the use of sym‐cis‐tetraphenylcyclotetrasiloxanolate nonaethanolate (1) gave previously unknown binuclear cage‐like copper silsesquioxane [(PhSiO1.5)10(CuO)2(NaO0.5)2·4EtOH] (2). The unprecedented structure of 2, the so called “Cooling Tower” structure, was confirmed by single‐crystal X‐ray diffraction analysis. Compound 2 was found to be an excellent catalyst in oxidation reactions of benzene and alcohols with peroxides in acetonitrile solution at 50–70 °C.
Palladium(II) Catalyzed Suzuki/Sonogashira Cross‐Coupling Reactions of Sulfonates: An Efficient Approach to C2‐Functionalized Pyrimidines and Pyridines
Authors: Quan Zheng‐Jun , Jing Fu‐Qiang , Zhang Zhang , Da Yu‐Xia , Wang Xi‐Cun 
Published: October 2013

AbstractPyrimidin‐2‐yl sulfonates, as a reaction partner, can be easily prepared from inexpensive commercial materials and are efficiently cross‐coupled with arylboronic acids and terminal alkynes by using Pd(OAc)2‐catalyzed Suzuki and Sonogashira reactions. A wide array of C2‐functionalized pyrimidines have been prepared in good to excellent yields. 2‐Arylpyridines and 2‐(oct‐1‐ynyl)pyridine were also synthesized.
Exploring a Multivalent Approach to α‐L‐Fucosidase Inhibition
Authors: Moreno‐Clavijo Elena , Carmona Ana T. , Moreno‐Vargas Antonio J. , Molina Lidia , Wright Daniel W. , Davies Gideon J. , Robina Inmaculada 
Published: October 2013

AbstractTo probe the utility of a multivalent approach for fucosidase inhibition, a series of di‐ and tri‐valent imino sugars based onL‐fuco‐configured 1,4‐imino‐ and 1,4‐bis(imino)‐cyclitol epitopes has been synthesized and analyzed for fucosidase inhibition with the best trivalent species yielding a modest improvement in binding constant. Structural analysis of a representative pair of mono‐ and tri‐valent imino sugars has been performed on a bacterial fucosidase,BtFuc2970. The 3D structures show binding of the imino‐cyclitol in the3Econformation, consistent with the known pathway for fucosidase action.
o‐Iodoxybenzoic Acid Mediated N‐Arylation of Aromatic Amines by Using Arylhydrazines as the Arylating Counterpart
Authors: Jadhav Ravindra R. , Huddar Sameerana N. , Akamanchi Krishnacharya G. 
Published: October 2013

AbstractThrough free‐radical trapping experiments we have established, for the first time, the combination of arylhydrazines with o‐iodoxybenzoic acid (IBX) for the generation of aryl free radicals. On the basis of this finding, a method was developed for the N‐arylation of aromatic amines under mild conditions (base‐free, –5 °C) by using arylhydrazines as the arylating counterpart and arylamines. The scope of this method was demonstrated by using a number of arylhydrazines and arylamines, which gave the N‐arylated amines in good yields.
5‐Alkenylthiazoles as In‐Out Dienes in Polar [4+2] Cycloaddition Reactions
Authors: Alajarin Mateo , Cabrera Jose , Sanchez‐Andrada Pilar , Bautista Delia , Pastor Aurelia 
Published: October 2013

Abstract5‐Alkenyl‐2‐aminothiazoles react as in‐out dienes with a wide range of electron‐poor dienophiles leading to the corresponding cycloaddition products in good to excellent yields. The [4+2] cycloadditions of 5‐alkenyl‐2‐aminothiazoles can be classified as site‐selective because only the diene moiety incorporating the formal C–C double bond of the heterocycle and that of the side‐chain is involved. Calculations of the HOMO energy values of representative 5‐alkenyl‐2‐aminothiazoles are disclosed. The cycloadditions are endo‐selective with N‐phenylmaleimide or maleic anhydride and regioselective when the reactions are conducted with nonsymmetrical dienophiles. Completely oxidized cycloadducts are obtained in the reactions of 5‐alkenyl‐2‐aminothiazoles with naphthoquinone or dimethyl acetylenedicarboxylate (DMAD). Unexpectedly, the reactions with 4‐phenyl‐1,2,4‐triazoline‐3,5‐dione (PTAD) are not stereospecific. A mechanism placed at the concerted/stepwise boundary is proposed.
A Two‐Step Sequence to Ethyl α‐Fluorocyclopropanecarboxylates Through MIRC Reaction of Ethyl Dichloroacetate and Highly Regioselective Fluorination
Authors: Zhang Min , Gong Yuefa , Wang Weizhou 
Published: October 2013

AbstractA two‐step sequence to ethyl α‐fluorocyclopropanecarboxylates has been developed. Ethyl α‐chlorocyclopropanecarboxylates were first obtained through a Michael‐initiated ring closure reaction of terminal electron‐deficient olefins with ethyl 2,2‐dichloroacetate under mild basic conditions. Subsequent smooth conversion into the corresponding monofluorinated analogues in good yields was through a halogen exchange reaction with potassium bifluoride. Further investigation clearly demonstrated that potassium bifluoride in this reaction system played a dual role of base and nucleophilic reagent. This is the first successful example reported hitherto for producing ethyl α‐fluorocyclopropanecarboxylate directly through fluorination of its chlorinated analogue with alkali bifluoride.
Synthesis of Thiodisaccharide Sulfoxides and Sulfones – Determination of the Configuration of the Sulfur Stereocentre
Authors: Colomer Juan P. , Manzano Veronica E. , Varela Oscar 
Published: October 2013

AbstractThe oxidation of per‐O‐acetyl S‐(1→3)‐ and S‐(1→4)‐linked thiodisaccharides containing glucose, gulose and galactose residues with an excess of m‐chloroperbenzoic acid gave the corresponding sulfoxides or sulfones. Sulfones were formed when the oxidation reaction was left for longer times. The sulfoxides were obtained as diastereomeric mixtures due to the chirality of the sulfur atom. Both diastereoisomers of the S‐(1→3)‐linked thiodisaccharide sulfoxides were isolated by column chromatography, whereas the S‐(1→4)‐linked analogues could not be separated. The absolute configuration of the sulfur stereocentre of the sulfoxides was assigned using NMR spectroscopy, taking into account the preferred conformations of the molecules, and the shielding/deshielding of proton signals caused by the anisotropy of the S=O bond and related effects. Most of the thiodisaccharide sulfoxides were successfully O‐deacetylated with MeOH/Et3N/H2O, but the sulfones underwent elimination reactions under these conditions. Therefore, the oxidation was performed on unprotected thiodisaccharides, and the corresponding sulfones were obtained in very good yields.
Stereocontrolled Total Synthesis of Sphingofungin E
Authors: Ikeuchi Kazutada , Hayashi Moemi , Yamamoto Tomohiro , Inai Makoto , Asakawa Tomohiro , Hamashima Yoshitaka , Kan Toshiyuki 
Published: October 2013

AbstractWe describe herein the asymmetric total synthesis of sphingofungin E, which has potent immunosuppressive activity. Key steps include asymmetric desymmetrization by bromolactonization, stereocontrolled construction of four contiguous stereogenic centers through allylic C–H oxidation and epoxide ring opening, regioselective elongation of a dialdehyde, and Hofmann rearrangement by using PhI(OCOCF3)2.
Restricting the scope of justice to justify discrimination: The role played by justice perceptions in discrimination against immigrants
Authors: Lima‐Nunes Aline , Pereira Cicero Roberto , Correia Isabel 
Published: October 2013

AbstractIn this research, we have analysed the role played by the scope of justice and belief in a just world (BJW) in discrimination against immigrants. In Study 1 (n = 185), we found that the relationship between prejudice and discrimination is mediated by a restricted view of the scope of justice. In addition, the results also showed that this mediation is moderated by BJW insofar as the mediation occurred in participants with a high level of BJW but not in participants with a low level of BJW. Studies 2 and 3 experimentally tested our prediction that the legitimising role played by the scope of justice is guided by a justice motive such as BJW. In both studies, the results showed a greater degree of discrimination against immigrants when a restricted scope of justice was considered but only when the BJW was made salient. In sum, these results introduced an innovation into the literature on the legitimation of social inequalities by demonstrating the relevant role played by the justice perceptions in discrimination against immigrants. Copyright © 2013 John Wiley & Sons, Ltd.
Selective Determination of Zn2+ Ion in Various Environmental, Biological and Medicinal Plant Samples Using a Novel Coated Graphite Electrode
Authors: Upadhyay Anjali , Singh Ashok Kumar , Rao Bandi Koteswara , Jain A. K. 
Published: October 2013

AbstractNovel Zn2+ ion‐selective PVC based coated graphite electrodes were fabricated using the ionophores N‐((1H‐indol‐3‐yl)methylene)thiazol‐2‐amine (I1), N‐((1H‐indol‐3‐yl)methyl)‐thiazol‐2‐amine (I2) and 1‐((1H‐indol‐3‐yl)methylene)urea (I3). Their potentiometric performance was examined in dependence of the addition of plasticizers and anion excluders and compared. It is found that the coated graphite electrode with the composition I1:KTpClPB:o‐NPOE:PVC=9 : 1.5 : 51 : 38.5 is the best with respect to the wide working concentration range (4.2×10−8–1.0×10−1 mol L−1), low detection limit (1.6×10−8 mol L−1) and wide pH range of 3.0–8.0. The proposed electrode was successfully applied to quantify Zn2+ in various environmental, biological and medicinal plant samples and used as indicator electrode.
Decomposition and Detection of Hydrogen Peroxide Using δ‐MnO2 Thin Film Electrode with Self‐Healing Property
Authors: Nakayama Masaharu , Sato Ayu , Yamaguchi Ryota 
Published: October 2013

AbstractA thin film of δ‐type MnO2 grown cathodically has been investigated with respect to the ability toward anodic decomposition of H2O2 and durability. With polarization at less positive potentials than +0.4 V vs. Ag/AgCl, the film was dissolved exclusively as a result of reduction of Mn4+ sites in the oxide by H2O2 to soluble Mn2+. At +0.9 V, MnO2 remained unchanged and decomposed H2O2 in solution. At +0.8 V, the film was once dissolved in the initial stage; however, it was self‐healed via reoxidation of the liberated Mn2+ ions. Amperometric flow‐injection analysis of H2O2 was carried out with the δ‐MnO2 film.
Rate and Extent of Carbon Dioxide Uptake In Room Temperature Ionic Liquids: A New Approach Using Microdisc Electrode Voltammetry
Authors: Li Peilin , Henstridge Martin C , Xiong Linhongjia , Compton Richard G. 
Published: October 2013

AbstractA simple method is introduced which enables the simultaneous determination of both the maximum CO2 concentration and kinetics of CO2 uptake and release by a room temperature ionic liquid. This method is based upon the analysis of chronoamperometry recorded in bulk ionic liquid at intervals during exposure to CO2 and subsequent exposure to vacuum to remove the dissolved CO2. Comparing experimental data with a numerical model reveals the rate‐limiting factors for both uptake and release of CO2.
Design of Sensitive Biocompatible Quantum‐Dots Embedded in Mesoporous Silica Microspheres for the Quantitative Immunoassay of Human Immunodeficiency Virus‐1 Antibodies
Authors: Zhou Hankun , Chen Si , Gan Ning , Li Tianhua , Cao Yuting , Jiang Qianli 
Published: October 2013

AbstractA novel sandwich‐type electrochemiluminescence (ECL) immunosensor was developed to enable the sensitive detection of HIV‐1 antibodies. This system incorporated mesoporous silica (mSiO2) complexed with quantum dots (QDs) and nano‐gold particles, which were assembled to enhance signal detection. Magnetic beads were used by immobilizing the secondary anti‐IgG antibody. This was first employed to capture HIV‐1 antibody (Ab) to form a Fe3O4/anti‐IgG/Ab complex. A high loading and signal‐enhanced nanocomposite (hereafter referred to as Au‐mSiO2‐CdTe) was used as a HIV‐1 antigen label. The Au‐mSiO2‐CdTe nanocomposite was conjugated with the Fe3O4/anti‐IgG/Ab complex to form an immunocomplex (hereafter referred to as Fe3O4/anti‐IgG/Ab/HIV‐1/CdTe‐mSiO2‐Au). This complex could be further separated by an external magnetic field to produce ECL signals. Due to the large specific surface area and pore volume of mSiO2, the loading of the CdTe QDs was markedly increased. Thus, the loaded QDs released a powerful chemiluminescent signal with a concordantly increased sensitivity of the immunosensor. The immunosensor was highly sensitive, and displayed a linear range of responses for HIV‐1 antibody across a dilution range of 1 : 1500 through 1 : 50 with the detection limit of 1 : 4500. The immunoassay can be a promising candidate in early diagnosis of HIV infection.
Investigation of the Electrochemical Behavior of Mesalazine on the Surface of a Glassy Carbon Electrode Modified with CNT/PPY Doped by 1,5‐Naphthalenedisulfonic Acid
Authors: Shahrokhian Saeed , Hosseini Pouya , Kamalzadeh Zahra 
Published: October 2013

AbstractA glassy carbon electrode (GCE) was modified with a thin layer of multiwalled carbon nanotubes (MWCNTs) and subsequently, electrochemically deposited poly‐pyrrole. The electrochemical behavior of mesalazine was studied on the surface of the modified electrode by applying linear sweep voltammetry (LSV). The electropolymerization process and the electrochemical response toward mesalazine were investigated in the presence of different aromatic anion dopants including, benzenesulfonic acid (BSA), 1,3‐benzenedisulfonic acid (1,3‐BDSA), 1,5‐naphthalenedisulfonic acid (1,5‐NDSA) and new coccine (NC). By using 1,5‐NDSA as dopant, a significant increase (∼418 times) in the peak current of mesalazine was observed, in comparison to the bare GCE. Experimental variables such as drop size of the cast MWCNTs suspension, pH of the supporting electrolyte, accumulation conditions and the number of scans in the electropolymerization process were optimized by monitoring the LSV responses of mesalazine. Under the optimum conditions, two linear dynamic ranges of 0.01–0.1 µmol L−1 and 0.1–1.0 µmol L−1 with a detection limit of 3 nmol L−1 were resulted for the voltammetric determination of mesalazine. The prepared electrode showed high sensitivity, stability and good reproducibility for determination of mesalazine. These properties made the prepared sensor suitable for the determination of mesalazine in pharmaceutical and clinical preparations.
Use of cereal crops for food and fuel – characterization of a novel bioethanol coproduct for use in meat poultry diets
Authors: Burton Emily J. , Scholey Dawn V. , Williams Peter E. V. 
Published: October 2013

AbstractThe rising volume of bioethanol production is likely to saturate the market for the current coproduct, distiller's dried grains with solubles (DDGS) as its high fiber content limits its use in nonruminant feed. A novel process has been developed which separates out a protein‐rich yeast fraction from the ethanol stillage which may be more suitable as a feed ingredient for nonruminants than DDGS. The aim of this study was to characterize a high protein coproduct stream from wheat bioethanol production and to examine its efficacy as a protein source in meat poultry diets. The novel material was evaluated by examining effects of dietary inclusion on both pellet quality and key nutrient parameters for broiler chickens including feed conversion efficiency, mineral availability, and digestible amino acid content. Results showed that the yeast protein concentrate appears to be a viable feed material with the potential to partially replace soya in poultry feed and could be produced in large volumes. This scale of production of sustainable protein could alleviate some of the pressures on other protein sources and mitigate the high proportion of cereal consumed through bioethanol production.
Redox Tolerance of Thin and Thick Ni/YSZ Anodes of Electrolyte‐Supported Single‐Chamber Solid Oxide Fuel Cells under Methane Oxidation Conditions
Authors: Wang Z. H. , Lü Z. , Chen K. F. , Wei B. , Zhu X. B. , Huang X. Q. , Su W. H. 
Published: October 2013

AbstractRedox tolerance of 50 and 500 μm thick Ni/YSZ (yttria‐stabilized zirconia) anodes supported on YSZ electrolytes were studied under single‐chamber solid oxide fuel cell conditions. Open circuit voltage, electrochemical impedance spectra, and discharge curves of the cells were measured under different methane/oxygen ratios at 700 °C. For the cell with the thin anode, a significant degradation accompanying oscillatory behaviors was observed, whereas the cell based on the thick anode was much more stable under the same conditions. In situ local anode resistance (Rs) results indicated that the Ni/NiO redox cycling was responsible for the oscillatory behaviors, and the cell degradation was primarily caused by the Ni reoxidation. Reoxidation of the thick anode took place at a low methane/oxygen ratio, but the anode can be recovered to its original state by switching to a methane‐rich environment. On the contrary, the thin anode was unable to be regenerated after the oxidation. Microstructure damage of the anode was attributed to its irreversible degradation.
Residual Stress and Biaxial Strength in Sc2O3–CeO2–ZrO2/Y2O3–ZrO2 Layered Electrolytes
Authors: Chen Y. , Aman A. , Lugovy M. , Orlovskaya N. , Wang S. , Huang X. , Graule T. , Kuebler J. 
Published: October 2013

AbstractMulti‐layered (Y2O3)0.08(ZrO2)0.92/(Sc2O3)0.1(CeO2)0.01‐(ZrO2)0.89(YSZ/SCSZ) electrolytes have been designed, so that the inner SCSZ layers provided superior ionic conductivity and the outer YSZ skin layers maintained good chemical and phase stability. Due to the mismatch of coefficients of thermal expansion between layers of different compositions, the thermal residual stresses were generated. The theoretical residual stress and strain were calculated for different thickness ratios of the electrolytes. In order to study the residual stress effect on the mechanical properties, the biaxial flexure tests of electrolytes with various layered designs were performed via a ring‐on‐ring method at room temperature and 800 °C. The maximum principal stress at the fracture indicated improved flexure strength in the electrolytes with layered designs at both temperatures. It is believed to be the result of the residual compressive stress in the outer YSZ layer. In addition, the Weibull statistics of the stress at the fracture at room temperature was studied, and the values of residual stress presented at the outer layer were well verified.