bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Clean Low‐Temperature ZnO Deposition Method for Multipurpose Applications
Authors: Estruga Marc , Gonzalez‐Valls Irene , Domingo Concepción , Lira‐Cantu Monica , Ayllón José A. 
Published: January 2011

AbstractZinc oxide (ZnO) was dissolved in an aqueous solution of ammonia and hydrogen peroxide. According to XRD characterization, this precursor solution yielded crystalline zincoxide after evaporation and thermal treatment at 90 °C for 2 h. The processability of this precursor solution allowed for ZnO deposition on cellulose paper, which is an example of a thermolabile substrate. Cellulose filter paper that was impregnated with this solution and subsequently thermally treated at 90 °C for 2 h had nanostructured crystalline ZnO well adhered to its surface. This composite material was characterized by XRD and scanning electron microscopy (SEM). The described precursor solution also assisted in the preparation of ZnO porous layers for dye‐sensitized solar cells (DSC). For this purpose, it was mixed with ZnO nanopowder dispersed in ethanol. The mixture was then sprayed on transparent conductive oxide substrates. In this way porous films were obtained after heat treatment at 90 °C for 2 h. Under standard testing conditions (AM1.5G, 100 mW cm–2), a device prepared with (Bu4N)2[Ru(dcbpyH)2(NCS)2] (dcbpy = 4,4′‐dicarboxy‐2,2′‐bipyridine) (N‐719) dye and a film thickness of 5 μm exhibited 1.43 % efficiency.
Electron‐Rich Vaska‐Type Complexestrans‐[Ir(CO)Cl(2‐Ph2PC6H4COOMe)2] andtrans‐[Ir(CO)Cl(2‐Ph2PC6H4OMe)2]: Synthesis, Characterisation and Reactivity
Authors: Dutta Dipak Kumar , Deb Biswajit , Sarmah Bhaskar Jyoti , Woollins J. Derek , Slawin Alexandra M. Z. , Fuller Amy L. , Randall Rebecca A. M. 
Published: January 2011

AbstractThe in‐situ‐generated dimeric precursor [Ir(CO)2Cl]2reacts with four molar equivalents of the ligands 2‐Ph2PC6H4COOMe (a) and 2‐Ph2PC6H4OMe (b) to afford tetracoordinated complexes of the typetrans‐[Ir(CO)ClL2] (1a,1b), where L =aandb. The IR spectra of1aand1bin CHCl3solution show the terminal υ(CO) bands at around 1957 and 1959 cm–1, respectively, which are significantly lower in frequency compared to Vaska's complex,trans‐[Ir(CO)Cl(PPh3)2] (1965 cm–1) and substantiate the enhanced electron density at the metal centre. The single‐crystal X‐ray structure of1aindicates iridium–oxygen (ester group) distances [Ir···O(2) 3.24 Å, Ir···O(5) 3.29 Å] and angle [O(5)···Ir···O(2) 157.25°] suggesting a long‐range intramolecular “secondary” Ir···O interaction resulting in a pseudo‐hexacoordinated complex. Complex1breacts with O2to generate [Ir(O2)(CO)Cl(2‐Ph2PC6H4OMe)2] (2b), while1aremains unreactive. Complex2bshows a distorted octahedral structure with peroxo O–O linkage (O2–O3 1.47 Å). The kinetic study of the reaction of1band Vaska's complex towards dioxygen addition reveals that the rate of dioxygen addition to1bis about three times faster than Vaska's complex. Complexes1aand1bundergo oxidative addition with small molecules like CH3I and I2to produce IrIIIcarbonyl species of the type [Ir(CO)Cl(CH3)IL2] (3a,3b) and [Ir(CO)ClI2L2] (4a,4b), where L =a,b.
Synthesis, Structure and Electrochemistry of Macrocyclic Tetrametallic Group 6 (Fischer) Carbene Complexes
Authors: López‐Alberca María P. , Mancheño María J. , Fernández Israel , Gómez‐Gallego Mar , Sierra Miguel A. , Hemmert Catherine , Gornitzka Heinz 
Published: January 2011

AbstractThe 1,4‐addition of diamine dinucleophiles to dimetalliccarbene scaffolds 5 yields tetrametallic azamacrocycles 9 and 10 with exocyclic metal–carbene nuclei, in excellent yields and with high stereocontrol. All‐Z stereoisomers are isolated in all cases, with the exception of the tungsten(0) macrocycle 10, which is obtained as a mixture of isomers. This methodology allows the preparation of a new type of homo‐ and heterocyclophane metallomacrocycles in which the geometry and the size of the cavity can be designed as a function of the biscarbene complexes employed and the diamines used as linkers. The X‐ray structure of complex 10a showing the high stability of the Z configuration of these compounds and the electrochemistry of the metallomacrocycles prepared are also reported.
Making and Breaking of P–P Bonds with Low‐Valent Transition‐Metal Complexes
Authors: Gómez‐Ruiz Santiago , Frank René , Gallego Beatriz , Zahn Stefan , Kirchner Barbara , Hey‐Hawkins Evamarie 
Published: January 2011

AbstractThe 1:1 or 1:2 stoichiometric reaction of [Na2(thf)4(P4Mes4)] (1; Mes = 2,4,6‐Me3C6H2) with [{RhCl(cod)}2] (cod = 1,5‐cyclooctadiene) gave a mixture of compounds of which [Na(thf)3][Rh(P3Mes3)(cod)] (2) with a trimesityltriphosphane‐1,3‐diide ligand was structurally characterized. Density functional calculations on 2 confirmed the structural parameters obtained by X‐ray diffraction studies. Shared electron number and natural bond orbital analyses indicated only weak interactions between Na and P, which were found to be even weaker than the Na–Rh interactions with covalent contribution. When an excess of 1 was used (3:1 or 4:1), 2 was also obtained as the major product together with small amounts of the side‐products cyclo‐P6Mes6 (3) and [Na3(Et2O)(P4Mes4)(PHMes)]∞ (4). Compounds 3 and 4 were only characterized by single‐crystal X‐ray diffraction studies. Their formation indicates that the reaction includes the breaking and making of P–P bonds to give (P3Mes3)2–, PHMes–, and cyclo‐P6Mes6, although the mechanism is unclear. Furthermore, the reaction of 1 with 2 equiv. of [AgCl(PPh3)2] gave the tetranuclear compound [Ag4(P6Mes6)2] (5) in which the novel (P6Mes6)2– ion also indicates degradation of the P4 chain followed by P–P bond formation.
An Effective Diels–Alder Reaction of Vinyl Allenols with Dienophiles
Authors: Choi Subin , Hwang Hoon , Lee Phil Ho 
Published: January 2011

AbstractVinyl allenols obtained from reaction of aldehydes with vinyl propargyl bromide and indium underwent Diels–Alder reactions with a variety of symmetric and unsymmetric dienophiles in dichloromethane or toluene regioselectively, producing cyclohexenylmethyl alcohols possessing an exo methylene moiety in good to excellent yield.
H3PW12O40‐Catalysed Alkylation of Arenes and Diveratrylmethanes: Convenient Routes to Triarylmethanes and to Symmetrical and Unsymmetrical 9,10‐Diaryl‐2,3,6,7‐tetramethoxyanthracenes
Authors: Mohammadpoor‐Baltork Iraj , Moghadam Majid , Tangestaninejad Shahram , Mirkhani Valiollah , Mohammadiannejad‐Abbasabadi Kazem , Khavasi Hamid R. 
Published: January 2011

AbstractAn efficient method for the synthesis of triarylmethanes and difurylarylmethanes through solventless reactions between aldehydes and arenes in the presence of H3PW12O40 as a reusable catalyst under thermal and microwave irradiation conditions has been developed. H3PW12O40‐catalysed one‐pot consecutive Friedel–Crafts reactions between veratrole and aldehydes were also applied as a convenient protocol for the preparation of symmetrical 9,10‐diaryl‐2,3,6,7‐tetramethoxyanthracenes. The conversion of aldehydes into their corresponding acylals in the presence of H3PW12O40 and the one‐pot reactions of diveratrylmethanes with these acylals were also used for the synthesis of symmetrical and unsymmetrical 9,10‐diaryl‐2,3,6,7‐tetramethoxyanthracenes.
Stereoselective Olefination of N‐Sulfonyl Imines with Stabilized Phosphonium Ylides for the Synthesis of Electron‐Deficient Alkenes
Authors: Fang Fan , Li Yuan , Tian Shi‐Kai 
Published: January 2011

AbstractAn unprecedented protocol has been developed for thestereoselective synthesis of structurally diverse electron‐deficient alkenes in moderate to excellent yields from readily accessible N‐sulfonyl imines and stabilized phosphonium ylides. Significantly, the olefination reaction of N‐sulfonylimines with nitrile‐stabilized phosphonium ylides affords an array of α,β‐unsaturated nitriles with high Z selectivity, and the reactions with ester‐, amide‐, and ketone‐stabilized phosphonium ylides afford α,β‐unsaturated esters, amides, and ketones with high E selectivity, respectively. Spectroscopic analysis of the reaction mixtures and trapping of the intermediates allow plausible mechanisms to be proposed. Initialimine/ylide addition leads to the formation of betaines that cyclize to form 1,2‐azaphosphetanes that subsequently eliminate iminophosphoranes to yield alkenes. For the synthesis of electron‐deficient 1,2‐disubstituted alkenes, the presence of an electron‐withdrawing group in the betaine allows rapid interconversion between its two diastereomers through proton transfer. The Z/E selectivity for alkene synthesis is determined by the different rates at which the two betaine diastereomers form the corresponding 1,2‐azaphosphetane diastereomers. In contrast, the Z/E selectivity for the synthesis of electron‐deficient trisubstituted alkenes originates from the diastereoselective addition of stabilized phosphonium ylides to N‐sulfonyl imines.
Synthesis and First Biological Evaluation of an Iron‐Containing HETE Analogue
Authors: Kausch‐Busies Nina , Kater Benjamin , Neudörfl Jörg M. , Prokop Aram , Schmalz Hans‐Günther 
Published: January 2011

AbstractAs previous studies in the field of bioorganometallic chemistry have unveiled, metal‐containing analogues of natural products frequently exhibit surprising biological activities. In this context, a synthetic approach to analogues of the eicosanoids 5‐HETE and 8‐HETE possessing a 1,3‐butadiene–Fe(CO)3 substructure was elaborated. The chosen structures are characterized by a central (2E,4Z)‐hexa‐2,4‐dien‐1‐ol–Fe(CO)3 moiety (as the potential “metal pharmacophore”) and carry a lipophilic ω‐6‐substituent as well as a hydrophilic α‐side chain (carboxylic acid). Using the cationic complex tricarbonyl[η5‐1‐(methoxycarbonyl)pentadienyl]iron hexafluorophosphate (rac‐4) as a starting material, the synthesis of a simplified Fe(CO)3‐complexed HETE analogue (rac‐3) was achieved by exploiting the addition of an alkynyl Cu species to rac‐4. The carbon skeleton was completed through diastereo(Ψ‐exo)selective addition of a titanium–zinc organyl [prepared from ethyl 4‐iodobutyrate, activated Zn powder, and Ti(OiPr)3Cl] as a butyrate D4 synthon to an aldehyde function by using 2‐Me‐THF as the solvent of choice. The (sensitive) target compound rac‐3 was shown to induce apoptosis at moderate concentrations in cancer cells (BJAB and Nalm‐6).
Study of the Structure and Photochemical Decomposition of Azidoadamantanes Entrapped in α‐ and β‐Cyclodextrin
Authors: Brinker Udo H. , Walla Peter , Krois Daniel , Arion Vladimir B. 
Published: January 2011

AbstractPhotolysis of 1‐azidoadamantane (1), either in its neat state or in alkane solution, yields the dimeric product 4. In contrast, amino alcohol 3 is formed as the sole product in high yield when 1 is confined within cyclodextrins (CyDs). To understand the discrepancy in product distribution caused by supramolecular encapsulation, CyD inclusion complexes (ICs) of azidoadamantanes were fully characterized. Indeed, intermolecular selectivity was influenced by reactant orientation and mobility. Both, 1‐ (1) and 2‐azidoadamantane (5) yield 1:1 ICs with β‐CyD and 1:2 ICs with α‐CyD. As inferred from 2‐D ROESY spectra in D2O, 1 is accommodated at the wider rim of β‐CyD with the azido group pointing into the cavity. However, two principal orientations of 5 inside the cavity of β‐CyD were found. Single crystal X‐ray analysis of solid 5 also demonstrates a bimodal orientation within β‐CyD. In addition, the first induced circular dichroism (ICD) study of an alkyl azide entrapped within CyD cavities is reported. From these data, it was concluded that azide 1 is bound more strongly within β‐CyD in H2O/EtOH = 8:2 at 293 K (Ka = 20240 ± 1000 M–1) than is 2‐azidoadamantane (5) (Ka = 7450 ± 400 M–1).
All‐Carbon‐Substituted Quaternary Carbon Atoms in Oxindoles by an Aerobic Palladium(II)‐Catalyzed Ring Closure onto Tri‐ and Tetrasubstituted Double Bonds
Authors: Schiffner Julia A. , Oestreich Martin 
Published: January 2011

AbstractOxidative palladium(II)‐catalyzed cyclization of α,β‐unsaturated amides derived from electron‐rich anilines is reported. The aerobic ring closure of tri‐ and tetrasubstituted alkenes yields oxindoles with congested all‐carbon‐substituted quaternary carbon atoms. The ring‐size selectivity is excellent. Selected unsymmetrically substituted arenes cyclize with perfect regioselectivity. Experimental evidence indicates that the mechanism is likely to involve Friedel–Crafts‐type electrophilic substitution rather than direct C–H bond activation.
Nucleophilic Trifluoromethylation of C=N Bonds
Authors: Dilman Alexander D. , Levin Vitalij V. 
Published: January 2011

AbstractThe review covers nucleophilic addition reactions of the CF3 carbanion to C=N bonds. Trifluoromethylation reactions of imines, nitrones, hydrazones, iminium ions and azomethine ylides are discussed. Various trifluorometylating reagents are considered, among which the major emphasis is placed on reactions using the Ruppert–Prakash reagent.
Direct Voltammetry of Copper, Zinc‐Superoxide Dismutase Immobilized onto Electrodeposited Nickel Oxide Nanoparticles: Fabrication of Amperometric Superoxide Biosensor
Authors: Salimi Abdollah , Noorbakhsh Abdollah , Rafiee‐Pour Hossain‐Ali , Ghourchian Hedayatollah 
Published: January 2011

AbstractDirect electron transfer of immobilized copper, zinc‐superoxide dismutase (SOD) onto electrodeposited nickel‐oxide (NiOx) nanoparticle modified glassy carbon (GC) electrode displays a well defined redox process with formal potential of −0.03 V in pH 7.4. Cyclic voltammetry was used for deposition of (NiOx) nanoparticles and immobilization of SOD onto GC electrode. The surface coverage (Γ) and heterogeneous electron transfer rate constant (ks) of immobilized SOD are 1.75×10−11 mol cm−2 and 7.5±0.5 s−1, respectively. The biosensor shows a fast amperometric response (3 s) toward superoxide at a wide concentration range from 10 µM to 0.25 mM with sensitivity of 13.40 nA µM−1 cm−2 and 12.40 nA µM−1 cm−2, detection limit of 2.66 and 3.1 µM based on anodically and cathodically detection. This biosensor exhibits excellent stability, reproducibility and long life time.
A Reference Electrode System for Electrochemical Measurements in Pure Water
Authors: Huang Hongliang , Wang Qiang , Cha Chuan‐Sin , Lu Juntao , Zhuang Lin 
Published: January 2011

AbstractA reference hydrogen electrode systems is constructed by employing a strip of proton‐type Nafion membrane as an ion‐conducting “bridge” to connect a reversible hydrogen electrode (RHE) in an acidic solution to an electrochemical system using pure water as electrolyte, in which the working electrode (WE) is placed. Using such a reference electrode system, the potential at the “WE/pure water” interface is equal to the equilibrium hydrogen electrode potential in pure water when the potential difference between RHE and WE is zero, irrespective of the pH value of the acidic solution in the RHE compartment. The accuracy and reproducibility of the WE potential measurements are within 1–2 mV.
The Voltammetric Responses of High and Low Molecular Weight DNA on a Variety of Carbon Substrates; Demonstrating the Benefits of Graphitic Surfaces
Authors: Gonçalves Luís M. , Batchelor‐McAuley Christopher , Xiong Linhongjia , Barros Aquiles A. , Compton Richard G. 
Published: January 2011

AbstractThis work compares the voltammetric response of high (∼2000 bp) and low (≤300 bp) molecular weight DNA on a variety of carbon based electrodes demonstrating for both species the advantages of using graphitic electrodes. Results suggest that the edge plane defects are kinetically dominant for the electro‐oxidation of nucleobases, whereas the basal plane sites are favoured for adsorption of the DNA to the electrode surface. For the high molecular weight DNA it is shown that although larger currents are obtained through the use of the edge plane electrode, it is beneficial in terms of signal‐to‐noise ratio to use a basal plane electrode.
Experimental study on retrofit of school buildings by adding sandwich columns to partition brick walls
Authors: Chung L. L. , Wu L. Y. , Lien K. H. 
Published: January 2011

AbstractThousands of buildings were damaged by the devastating Chi‐Chi earthquake on September 21, 1999. Of all the public buildings, school buildings are the most vulnerable to earthquake damage, and the retrofitting of existing school buildings becomes a stringent issue. In addition to cost effectiveness, the impact of retrofitting methods on the functions of the school buildings needs to be considered. This paper therefore proposes the retrofitting of school buildings by adding sandwich columns onto partition brick walls. The sandwich column is divided into two parts and is added to the two sides of the partition brick wall held with pairs of U‐shaped bars. The retrofit does not require the removal of windows or doors in the longitudinal direction making the proposed method cost effective and minimizes the impact on the function of the school buildings. Five full‐scale specimens without and with retrofitting were designed and fabricated for testing based on the partition brick wall frames of the existing school buildings. The specimens were subjected to cyclic loading in the out‐of‐plane direction through a loading frame so that the columns deformed with double curvatures. The experimental results verified the feasibility of the proposed retrofit method. The data showed that the lateral strength of the retrofitted specimen doubled that which was not and that the residual strength of the retrofitted specimen was just as high as the ultimate strength of the specimen without retrofitting. The analytical results in lateral strength yielded conservative figures compared with experimental measurements. Copyright © 2011 John Wiley & Sons, Ltd.
Shake table tests on clutter levels of typical medicine shelves and contents subjected to earthquakes
Authors: Kuo Keng‐Chang , Suzuki Yoshiyuki , Katsuragi Satoko , Yao George C. 
Published: January 2011

AbstractOverturned shelves and fallen objects scattered on floors are one of the most frequently observed forms of nonstructural damage after earthquakes. The term ‘clutter’ is adopted in this study to represent this type of damage. Clutter may cause obstructions and thus hinder the use of a room. Making a seismic evaluation of clutter is a daunting task, due to the diversity of the types of shelves and objects and the way the objects are stored. Nonetheless, in order to achieve performance‐based seismic evaluation, especially for critical facilities such as hospitals, it is reasonable to undertake the estimation of clutter when examining the association between the performance of structural and nonstructural elements. Of particular interest in this paper is clutter caused by objects stored on medicine shelves in pharmacies, which are one of the critical departments for delivering post‐earthquake emergency care. Shake table tests were conducted on three conventional types of medicine shelves. Sinusoidal waves and earthquake motions were input uniaxially. The results of the tests using the sinusoidal wave input indicated the relationship between the input excitation intensity and clutter level expressed in scattering distance from the front of the shelf. Tests using earthquake motion input were then conducted and the results were compared with those for sinusoidal waves. Based on a comparison of the results from these tests, criteria for the seismic evaluation of clutter caused by medicine shelves due to earthquakes were proposed. Copyright © 2011 John Wiley & Sons, Ltd.
Causality in the VIX futures market
Authors: Shu Jinghong , Zhang Jin E. 
Published: January 2011

AbstractThis study examines the price‐discovery function and information efficiency of a fast growing volatility futures market: the Chicago Board of Option Exchange VIX futures market. A linear Engle–Granger cointegration test with an error correction mechanism (ECM) shows that during the full sample period, VIX futures prices lead spot VIX index, which implies that the VIX futures market has some price‐discovery function. But a modified Baek and Brock nonlinear Granger test detects bi‐directional causality between VIX and VIX futures prices, suggesting that both spot and futures prices react simultaneously to new information. Quarter‐by‐quarter investigations show that, on average, the estimated parameters are not significantly different from zero, thus providing further evidence supporting information efficiency in the VIX futures market. © 2011 Wiley Periodicals, Inc. Jrl Fut Mark
A note on utility‐based futures hedging performance measure
Authors: Lien Donald 
Published: January 2011

AbstractThis note considers the estimator for the utility‐based hedging performance. It shows that the estimator incurs a downward bias, regardless of whether the conventional mean‐variance expected utility function or the more general risk‐averse utility function is adopted. Consequently, the usefulness of the futures contract is under‐estimated. © 2011 Wiley Periodicals, Inc. Jrl Fut Mark
Nuclear Receptors in Liver Disease Δ
Authors: Wagner Martin , Zollner Gernot , Trauner Michael 
Published: January 2011

Abstract

Nuclear receptors are ligand-activated transcriptional regulators of several key aspects of hepatic physiology and pathophysiology. As such, nuclear receptors control a large variety of metabolic processes including hepatic lipid metabolism, drug disposition, bile acid homeostasis, as well as liver regeneration, inflammation, fibrosis, cell differentiation, and tumor formation. Derangements of nuclear receptor regulation and genetic variants may contribute to the pathogenesis and progression of liver diseases. This places nuclear receptors into the frontline for novel therapeutic approaches for a broad range of hepatic disorders and diseases including cholestatic and fatty liver disease, drug hepatotoxicity, viral hepatitis, liver fibrosis, and cancer. (Hepatology 2011;.)
IL28B Genetic Variation and Treatment Response in Patients with Hepatitis C Virus Genotype 3 Infection σ
Authors: Moghaddam Amir , Melum Espen , Reinton Nils , Ring-Larsen Helmer , Verbaan Hans , Bjφro Kristian , Dalgard Olav 
Published: January 2011

Abstract

Polymorphisms near the

IL28B

gene, which code for interferon (IFN)-λ3, predict response to pegylated interferon-α (PEG-IFN) and ribavirin treatment in hepatitis C virus (HCV) genotype 1 infected patients. Follow-up studies of the effect of

IL28B

gene in HCV non–genotype 1 infected patients have almost always used predominantly HCV genotype 2–infected or mixed genotype 2/3–infected cohorts with results partly conflicting with HCV genotype 1. We performed a retrospective analysis of 281 patients infected with HCV genotype 3 for association of response to therapy with

IL28B

polymorphisms. We found that the HCV genotype 1 responder genotypes at rs12979860 and rs8099917 did not associate with sustained virological response to PEG-IFN/ribavirin therapy. However, the responder genotypes of both SNPs showed association with rapid viral response measured at 4 weeks (rs12979860,

P

= 3 × 10−5; rs8099917,

P

= 3 × 10−4). In multivariate analysis, age (<40 years), baseline viral load (<4 × 105 IU/mL) and the responder genotypes of SNPs rs12979860 or rs8099917 remained significant independent predictors of rapid viral response to therapy. Furthermore, we show that

IL28B

polymorphisms are associated with relapse in patients who achieve rapid viral response to PEG-IFN/ribavirin therapy. The responder genotypes also showed association with markers of stage and activity of liver disease, namely high aspartate aminotransferase platelet ratio index (APRI, rs12979860,

P

= 0.018; rs8099917, not significant) and high alanine aminotransferase (ALT, rs12979860,

P

= 0.002; rs8099917,

P

= 0.001), in addition to a high baseline viral load (rs12979860,

P

= 1.4 × 10−5; rs8099917,

P

= 7.3 × 10−6).

Conclusion:

Polymorphisms near the IL28B gene show association with rapid viral response but not sustained viral response to PEG-IFN/ribavirin therapy in HCV genotype 3-infected patients. (Hepatology 2011;)