bluuebunny/crossref_metadata_2025 huggingface dataset:
Using tests to enhance 8th grade students' retention of U.S. history facts
Authors: Carpenter Shana K. , Pashler Harold , Cepeda Nicholas J.
Published: August 2008

Laboratory studies show that retention of information can be powerfully enhanced through testing, but evidence for their utility to promote long‐term retention of course information is limited. We assessed 8th grade students' retention of U.S. history facts. Facts were reviewed after 1 week, 16 weeks or not reviewed at all. Some facts were reviewed by testing (Who assassinated president Abraham Lincoln?) followed by feedback (John Wilkes Booth), while others were re‐studied. Nine months later, all students received a test covering all of the facts. Facts reviewed through testing were retained significantly better than facts reviewed through re‐studying, and nearly twice as well as those given no review. The best retention occurred for facts that were reviewed by testing after a 16‐week time interval. Although the gain in item was numerically small, due to floor effects, these results support the notion that testing can enhance long‐term retention of course knowledge. Copyright © 2008 John Wiley & Sons, Ltd.
When goals constrain: Eye movements and memory for goal‐Oriented map study
Authors: Brunyé Tad T. , Taylor Holly A.
Published: August 2008

Perspective goals, such as studying a map to learn a route through an environment or the overall layout of an environment, produce memory congruent with the goal‐directed rather than the studied perspective. One explanation for this finding is that perspective goals guide attention towards actively gathering relevant information during learning. A second explanation is that information is automatically organized into a goal‐congruent spatial model that guides retrieval. Both explanations predict goal‐congruent memory, but only the former one predicts eye movement differences during study. The present experiment investigated the effect of perspective goals on eye movement during map study and the flexibility of resulting spatial memories. Results demonstrate eye movements towards goal‐congruent map elements during learning, and lasting memory effects at test. These findings carry implications for the design of adaptive hand‐held and in‐vehicle navigation interfaces that accommodate for varied user goals. Copyright © 2008 John Wiley & Sons, Ltd.
Selectivity versus conversion and optimal operating policies for plants with recycle
Authors: Griffin Derek W. , Mellichamp Duncan A. , Doherty Michael F.
Published: August 2008

A simple and fast procedure is developed for determining optimal steady state operating policies for chemical plants with recycle. This article improves upon the previous findings by Griffin et al. (Ind Eng Chem Res. 2006;45:8056‐8062) and now provides a more general classification procedure for process chemistries that have reversible reactions or reactions of unequal overall order or both. Selectivity vs. conversion relationships are indirectly determined herein, requiring only the reaction orders of reaction species. The effect of these relationships allows process chemistries to be classified into two equivalence classes: bounded and nonbounded. This classification has important implications for the optimal operation and plantwide control structure of a flexible plant with spare equipment capacity. For instance, using the classification procedure and decision tree developed in this article, it can be determined quickly whether or not it is economically optimal to operate the reactor at the holdup constraint under all operating conditions (bounded) or away from the constraint with a variable holdup operating policy (nonbounded). © 2008 American Institute of Chemical Engineers AIChE J, 2008
Reactive scheduling using parametric programming
Authors: Li Zukui , Ierapetritou Marianthi G.
Published: August 2008

To address the various disruptive events that occur during process operations, reactive scheduling is commonly used. However, a major limitation of the existing reactive scheduling techniques is the response time, which might cause significant delay while the generation of a new schedule takes place. In this article, a novel approach is proposed to improve the efficiency of reactive scheduling and to avoid the resolution of a complex optimization problem when uncertain event occurs during the scheduling period. In the proposed method, reactive schedule is obtained from the solution of multiparametric programming problem, which is solved ahead of time and covers all possible outcomes of future uncertainty. The multiparametric programming problem is derived from a new reactive scheduling formulation, which integrates disruptive events (rush order and machine breakdown) as uncertain parameters in the process modeling. Several examples are presented to illustrate the effectiveness of the proposed approach. © 2008 American Institute of Chemical Engineers AIChE J, 2008
A review and analysis of the relationship between neuropsychological measures and DAT1 in ADHD
Authors: Rommelse Nanda N.J. , Altink Marieke E. , Arias‐Vásquez Alejandro , Buschgens Cathelijne J.M. , Fliers Ellen , Faraone Stephen V. , Buitelaar Jan K. , Sergeant Joseph A. , Franke Barbara , Oosterlaan Jaap
Published: August 2008

Meta‐analyses indicate that the gene coding for the dopamine transporter (DAT1 or SLC6A3) is associated with an increased risk for ADHD. The mechanisms of this gene for ADHD are unclear. We systematically reviewed studies linking the VNTR in the 3′ UTR of the DAT1 to neurophysiological and neuropsychological measures. In addition, a broad set of executive/cognitive and motor tests was administered to 350 children (5–11 years) and adolescents (11–19 years) with ADHD and 195 non‐affected siblings. Two VNTRs (in intron 8 and the 3′ UTR) and four SNPs (two 5′ and two 3′) in DAT1 were genotyped. The effect of the polymorphisms on neuropsychological functioning was studied. The review indicated that the majority of studies did not find a relation between DAT1 and neurophysiological or neuropsychological measures. In our sample, several of the polymorphisms of DAT1 were associated with ADHD and ADHD was associated with impaired neuropsychological functioning. However, none of the DAT1 polymorphisms was convincingly associated with neuropsychological dysfunctioning. This suggests that the effect of DAT1 on ADHD was not mediated by neuropsychological performance. However, since DAT1 is mainly expressed in the striatum and not the prefrontal cortex, it may influence striatum‐related functions (such as delay aversion) more heavily than prefrontal related functions (such as executive functions). Associations of DAT1 with ADHD were only found in adolescents, which may suggest that DAT1 mainly exerts its effect in adolescence, and/or that having a more persistent form of ADHD may mark a more severe or homogeneous genetic form of the disorder. © 2008 Wiley‐Liss, Inc.
Thermal properties and flame retardancy of polyglycidyloxypropyl silsesquioxane/layered titanate nanocomposites
Authors: Harada Miyuki , Minamigawa Shuichi , Ochi Mitsukazu
Published: August 2008

Polyglycidyloxypropyl silsesquioxane, which has an excellent heat resistance, was combined with sheet‐like and spherical titanate as nano‐fillers. The burning property of the composites was related to the shape of the dispersed titanate. A burning test was carried out according to the UL‐94 test method. As a result, though the test specimen burned from one end to the other in the spherical titanate filled composite system, a fire extinguishing property was observed in the sheet‐like titanate filled composite system. The extinguishing time of the latter system classified V‐0 in the specification test. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Graft copolymerization of acrylic acid onto cocoyam starch by ceric ion in the presence of N,N′‐dimethylacetamide
Authors: Eromosele I. C. , Eromosele C. O. , Ayinde K. S. , Adegoke O.
Published: August 2008

Grafting of acrylic acid onto cocoyam starch, Xanthosoma sagittitolium was initiated by ceric ion—N,N′‐dimethylacetamide redox pair in aqueous media. The reaction was characterized by high graft yields of up to 676%, and infrared spectroscopy affirmed the presence of grafted polymer. Graft yield was enhanced by N,N′‐dimethylacetamide (DMAc) in the concentration range, 9.0–36.0 × 10−4M but lower concentrations were more favorable with the ratio of percentage graft, Pg/Pg0, in the presence and absence of DMAc respectively, of up to 1.34 at 9.0 × 10−4M of the latter. Ceric ion was nonterminating of the graft reaction and a 10‐fold increase in its concentration of 4.16 × 10−3M resulted in high efficiency of graft of 50.2% in monomer conversion to grafted polymer. Enhanced homopolymer formation and low efficiency of graft were observed at monomer concentration greater than 0.69M. Long reaction time, greater than 30 min, was unfavorable to the graft reaction and the latter showed negative dependence on temperature in the range, 30–50°C. At 30‐min reaction time, the graft yield at 50°C was not more than 70% of the corresponding value at 30°C. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis of geranyl butyrate with the poly(acrylic acid‐co‐hydroxy propyl methacrylate‐cl‐ethylene glycol dimethacrylate) hydrogel immobilized lipase of Pseudomonas aeruginosa MTCC‐4713
Authors: Kanwar Shamsher S. , Gehlot Satyendra , Verma Madan Lal , Gupta Reena , Kumar Yogesh , Chauhan Ghansham S.
Published: August 2008

Microbial lipases (E.C. 3.1.1.3) are the preferred biocatalysts for the synthesis of various fragrance compounds, such as linalool acetate, citronellal acetate, and geranyl acetate, in organic solvents over chemical synthesis. In this study, a purified alkaline extracellular lipase of Pseudomonas aeruginosa MTCC‐4713 was efficiently immobilized onto a synthetic poly(AAc‐co‐HPMA‐cl‐EGDMA) hydrogel by surface adsorption, and the bound lipase was evaluated for its hydrolytic potential toward various p‐nitrophenyl acyl esters, which differed in their C‐chain length. Among four series of hydrogels prepared by the variation of the concentrations of monomer and crosslinker, two hydrogels, namely, I5d and I20d, that exhibited relatively higher protein (lipase activity) bindings were selected to perform hydrolytic and synthetic (geranyl butyrate) reactions in aqueous and organic solvents. The hydrogel‐bound lipase was highly hydrolytic toward p‐nitrophenyl ester (C: 16; p‐nitrophenyl palmitate). The hydrogel‐immobilized lipase was quite stable and retained approximately 57.6% of its original hydrolytic activity after the fifth cycle of reuse under optimized conditions (pH 8.5, 65°C). The hydrogel‐immobilized lipase when used to perform the esterification of geraniol/butyric acid (400 : 100 mM) in n‐heptane resulted in 98.8 mM geranyl butyrate at 65°C under shaking (120 rpm) after 15 h of reaction time. The addition of a molecular sieve (3 Å × 1.5 mm) to the reaction system at a concentration of 100 mg per reaction volume (1 mL) resulted in the complete conversion of the reactants into geranyl butyrate. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Nanostructured PZT synthesized from metal–polyvinyl alcohol gel: Studies on metal–polymer interaction
Authors: Roy Subir
Published: August 2008

PbZr0.53Ti0.47O3 (PZT) nanoparticles of size distribution ∼1–6 nm were synthesized by single‐step autoignition of metal–polyvinyl alcohol (PVA) gel. The physical and chemical bonding between the metals ions and PVA in gel was analyzed from the results of the characterization by FTIR, SEM, and XRD techniques. The appearance of a doublet band between 3500 and 3200 cm−1 and the shifting of stretching frequency of OH band in the FTIR spectra of gel indicated strong electrostatic interaction between the metal ions and the polar OH groups of the polymer. The electrostatic interaction decreased the extent of hydrogen bonding drastically due to engagement of polar OH groups in complex formation with the metal ions. Microstructural study of the dried gel by SEM coupled with its FTIR analyses indicated crosslinking in the metal–polymer gel. The loss of crystallinity of PVA in gel detected by XRD also indicated the drastic degradation of hydrogen bonding in PVA due to the formation of coordination complex with the metal ions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Comparison of the corrosion protection of mild steel by polypyrrole–phosphate and polypyrrole–tungstenate coatings
Authors: Hosseini M. G. , Sabouri M. , Shahrabi T.
Published: August 2008

The electrodeposition of polypyrrole–phosphate (PPy–P) and polypyrrole–tungstenate (PPy–W) on mild steel (MS) were achieved in an oxalic acid medium with cyclic voltammetry techniques. Adherent and homogeneous PPy–P and PPy–W films were obtained. The corrosion behavior of mild steel with phosphate (PPy–P) and tungstenate (PPy–W) composite coatings in 3.5% NaCl solutions were investigated through a potentiodynamic polarization technique, open‐circuit potential–time curves, and electrochemical impedance spectroscopy (EIS). On the basis of a physical model for corrosion of mild steel composites, Zview (II) software was applied to the EIS to estimate the parameters of the proposed equivalent circuit. It was found that the PPy–W coatings could provide much better protection than the PPy–P and polypyrrole coatings. The effects of the phosphate and tungstenate process parameters on the morphology and structure of the passive films were investigated by scanning electron microscopy and electron dispersion X‐ray analyses. The results reveal that the PPy–P and PPy–W coated electrodes offered a noticeable enhancement in protection against corrosion processes. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Practical work of crack growth and environmental stress cracking resistance of semicrystalline polymers
Authors: Sharif A. , Mohammadi N. , Ghaffarian S. R.
Published: August 2008

The area fraction of tie molecules at the crystal–amorphous interface, amorphous phase dynamics, average crystal strength against stem sliding, and crack growth tortuosity concepts have been used simultaneously, for the first time, to develop a model for predicting the environmental stress cracking resistance of semicrystalline polymers. The model is based on the analogy of crack growth through the amorphous phase of semicrystalline polymers in a harsh environment at adhesive polymer–substrate interfaces. The model variable consists of the practical work of crack growth (Gc) times the crack growth path tortuosity (Γ) and correlates very well with the time to failure in the full notch creep test (FNCT) through a sigmoidal‐type equation: FNCT = a{1 + exp[(b − GcΓ)/c]}−1, where a (3386), b (0.16), and c (0.006) are constants (r2 = 0.999). Gc is calculated by multiplication of the area fraction of tie molecules at the crystal–amorphous interface, the amorphous phase loss factor value at −25°C, and the sample storage shear modulus at the test temperature, whereas Γ is estimated as the product of the sample molecular weight and its distribution. The application of the Kendall rank correlation coefficient test as a primitive gross criterion of comparison among the proposed correlations also shows reasonable values of the rank correlation coefficient (0.891) and probability (0.000) for the new model. In other words, a point‐to‐point increasing or descending trend among the experimentally found data is ignored in comparison with the sound physical basis of the correlation toward the development of a comprehensive model. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
New aspects of viscosity effects on the photopolymerization kinetics of the 2,2‐bis[4‐(2‐hydroxymethacryloxypropoxy)phenyl]propane/triethylene glycol dimethacrylate monomer system
Authors: Andrzejewska Ewa , Marcinkowska Agnieszka
Published: August 2008

The photopolymerization kinetics and viscosity behavior of 11 2,2‐bis[4‐(2‐hydroxymethacryloxypropoxy)phenyl]propane/triethylene glycol dimethacrylate mixtures were investigated. The viscosity was studied at six temperatures (20–70°C), and the activation energies for the viscosity were determined. The excess logarithm viscosities were calculated and found to be negative over the whole composition and temperature ranges; they were fitted to the Redlish–Kister polynomial equation. The kinetic analysis of the photopolymerization was carried out at three polymerization temperatures (20, 40, and 60°C). The results proved the existence of the most reactive composition (reaching the highest value of the maximum polymerization rate), but the ratio of the monomers in this composition, close to equimolar, showed a tendency to change with the polymerization temperature. The viscosities of the most reactive compositions lay in the range of about 0.1–1.2 Pa s, which was narrow in comparison with the range of viscosities of all the compositions used in the kinetic studies (from 3 × 10−3 to 1.5 × 103 Pa s). The activation energies for the polymerization rates were calculated and correlated with the viscosity changes. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
1,3‐ and 1,2‐Carbo‐Migration of 2‐Vinylbicyclo[2.2.2]octenols: Facile and Concise Synthesis of Bicyclo[4.2.2]/[3.2.2] Skeleton by Two/One‐Carbon Ring Expansion
Authors: Lu Yan‐Bin , Lee Tsung‐Ho , Liu Wen‐Cheng , Chuang Gary Jing , Liao Chun‐Chen
Published: August 2008

The synthesis of a series of bicyclo[4.2.2]octenones and bicyclo[3.2.2]heptenones by 1,3‐ or 1,2‐migration reaction from 2‐vinylbicyclo[2.2.2]octenols is reported. These ring‐expansion reactions were accomplished under basic or neutral conditions. Whether 1,3‐ or 1,2‐migration takes place depends on endo‐ or exocyclic olefin displacement in the substrates.
Acid–Base Bifunctional Catalytic Surfaces for Nucleophilic Addition Reactions
Authors: Motokura Ken , Tada Mizuki , Iwasawa Yasuhiro
Published: August 2008

This article illustrates the modification of oxide surfaces with organic amine functional groups to create acid–base bifunctional catalysts, summarizing our previous reports and also presenting new data. Immobilization of organic amines as bases on inorganic solid–acid surfaces afforded highly active acid–base bifunctional catalysts, which enabled various organic transformations including CC coupling reactions, though these reactions did not proceed with either the homogeneous amine precursors or the acidic supports alone. Spectroscopic characterization, such as by solid‐state MAS NMR and FTIR, revealed not only the interactions between acidic and basic sites but also bifunctional catalytic reaction mechanisms.
Second‐generation biofuels and local bioenergy systems
Authors: Antizar‐Ladislao Blanca , Turrion‐Gomez Juan L.
Published: August 2008

First‐generation biofuels, mainly from corn and other food‐based crops are being used as a direct substitute for fossil fuels in transport. However, they are available in limited volumes that do not make them serious replacements for petroleum. Second‐generation biofuels from forest and crop residues, energy crops and municipal and construction waste, will arguably reduce net carbon emission, increase energy effi ciency and reduce energy dependency, potentially overcoming the limitations of fi rst‐generation biofuels. Nevertheless, implementation of second‐generation biofuels technology will require a sustainable management of energy, or development of local bioenergy systems. This study aims at identifying second‐generation biofuel feedstock. It also provides information on the available technologies to produce second‐generation biofuels. Finally it discusses the development of local bioenergy systems vs sustainable use of second‐generation biofuels. Locally produced second‐generation biofuels will exploit local biomass to optimize their production and consumption. © 2008 Society of Chemical Industry and John Wiley & Sons, Ltd
A vector system for genomic FLAG epitope‐tagging in Schizosaccharomyces pombe
Authors: Noguchi Chiaki , Garabedian Mikael V. , Malik Marriam , Noguchi Eishi
Published: August 2008

The fission yeast Schizosaccharomyces pombe is a popular model organism to study various cellular processes, although research tools available for S. pombe are relatively inadequate. To facilitate genetic and biochemical investigation in S. pombe, we report here a system of vectors for genomic FLAG epitope‐tagging. These vectors enable us to amplify gene‐targeting fragments for integration into specific loci of the S. pombe genome. All vectors in this report were designed to express FLAG epitope‐tagged proteins from their endogenous genomic loci. Vectors for N‐terminal FLAG epitope‐tagging allow us to control protein expression levels using the wild‐type nmt1 promoter, its weaker derivatives, and the urg1 promoter. These vectors are available with various antibiotic markers including kanMX6, hphMX6, natMX6 and bleMX6, and the his3+ marker. Vectors for C‐terminal FLAG epitope‐tagging were designed to express FLAG‐fusion proteins under the control of their native promoters at their own genomic loci, allowing us to characterize protein functions under physiological conditions. These vectors are available with kanMX6, hphMX6, nat‐MX6 and bleMX6 markers. The series of vectors described in this report should prove useful for protein studies in fission yeast.
Synthesis, Crystal Structure, and DNA‐Cleaving Behavior of 5‐Substituted Benzene‐1,3‐bis(methylene)‐Spaced Dinuclear Copper(II) Complexes
Authors: Li Tuanjie , Du Jun , Li Tao , Wu Ziyi , He Weijiang , Zhu Jianhui , Guo Zijian
Published: August 2008

Three meta‐dicopper complexes, 1–3, based on 5‐substituted 1,3‐xylylene spacer have been synthesized. These complexes are capable of inducing the transformation of supercoiled DNA (pUC19) to its nicked and linear DNA form in the presence of ascorbate, and their DNA nicking efficiency can be correlated to their DNA‐binding ability. The cleavage mechanism is similar to that of the non‐substituted meta‐dicopper complex A. Amongst the three complexes, 5‐(aminomethyl)‐substituted complex 3 displayed a higher DNA‐binding ability and nicking efficiency than unsubstituted complex A. The CD‐spectroscopic study and structural analysis imply that the different Cu⋅⋅⋅Cu distances and DNA binding modes induced by different 5‐substituents on benzene‐1,3‐bis(methylene) spacer may be responsible for the different DNA cleaving behavior of meta‐dicopper complexes.
The Thulium Complex of 1,4,7,10‐Tetrakis{[N‐(1H‐imidazol‐2‐yl)carbamoyl]methyl}‐1,4,7,10‐tetraazacyclododecane (dotami) as a ParaCEST Contrast Agent
Authors: Burdinski Dirk , Lub Johan , Pikkemaat Jeroen A. , Langereis Sander , Grüll Holger , ten Hoeve Wolter
Published: August 2008

1,4,7,10‐Tetrakis{[N‐(1H‐imidazol‐2‐yl)carbamoyl]methyl}‐1,4,7,10‐tetraazacyclododecane (dotami), a tetra(1H‐imidazol‐2‐yl) derivative of the well‐studied octadentate 1,4,7,10‐tetrakis[(carbamoyl)methyl]‐1,4,7,10‐tetraazacyclododecane (dotam) ligand, was synthesized by reaction of 1,4,7,10‐tetraazacyclododecane with N‐(1H‐imidazol‐2‐yl)chloroacetamide in high yield. Its tricationic thulium complex was isolated as a water‐soluble chloride salt. The detection of the mildly acidic amide and amine protons by direct proton NMR in aqueous solution was unsuccessful, but such exchangeable protons could be detected via their chemical exchange‐dependent saturation transfer (CEST) effect. The observed CEST effect was distinctly different from that found for respective dotam complexes and is, therefore, ascribed to exchangeable protons associated with the imidazole substituent.
Eutectic Phase in Water‐Ice: A Self‐Assembled Environment Conducive to Metal‐Catalyzed Non‐Enzymatic RNA Polymerization
Authors: Monnard Pierre‐Alain , Ziock Hans
Published: August 2008

Information and catalytic polymers play an essential role in contemporary cellular life, and their emergence must have been crucial during the complex processes that led to the assembly of the first living systems. Polymerization reactions producing these molecules would have had to occur in aqueous medium, which is known to disfavor such reactions. Thus, it was proposed early on that these polymerizations had to be supported by particular environments, such as mineral surfaces and eutectic phases in water‐ice, which would have led to the concentration of the monomers out of the bulk aqueous medium and their condensation. This review presents the work conducted to understand how the eutectic phases in water‐ice might have promoted RNA polymerization, thereby presumably contributing to the emergence of the ancient information and catalytic system envisioned by the ‘RNA‐World’ hypothesis.
Addition of DNA to CrVI and Cytochrome b5 Containing Proteoliposomes Leads to Generation of DNA Strand Breaks and CrIII Complexes
Authors: Borthiry Griselda R. , Antholine William E. , Myers Judith M. , Myers Charles R.
Published: August 2008

Chromium (Cr) is a cytotoxic metal that can be associated with a variety of types of DNA damage, including Cr‐DNA adducts and strand breaks. Prior studies with purified human cytochrome b5 and NADPH : P450 reductase in reconstituted proteoliposomes (PLs) demonstrated rapid reduction of CrVI (hexavalent chromium, as CrO), and the generation of CrV, superoxide (O2.−), and hydroxyl radical (HO.). Studies reported here examined the potential for the species produced by this system to interact with DNA. Strand breaks of purified plasmid DNA increased over time aerobically, but were not observed in the absence of O2. CrV is formed under both conditions, so the breaks are not mediated directly by CrV. The aerobic strand breaks were significantly prevented by catalase and EtOH, but not by the metal chelator diethylenetriaminepentaacetic acid (DTPA), suggesting that they are largely due to HO. from Cr‐mediated redox cycling. EPR was used to assess the formation of Cr‐DNA complexes. Following a 10‐min incubation of PLs, CrO, and plasmid DNA, intense EPR signals at g=5.7 and g=5.0 were observed. These signals are attributed to specific CrIII complexes with large zero field splitting (ZFS). Without DNA, the signals in the g=5 region were weak. The large ZFS signals were not seen, when CrIIICl3 was incubated with DNA, suggesting that the CrIIIDNA interactions are different when generated by the PLs. After 24 h, a broad signal at g=2 is attributed to CrIII complexes with a small ZFS. This g=2 signal was observed without DNA, but it was different from that seen with plasmid. It is concluded that EPR can detect specific CrIII complexes that depend on the presence of plasmid DNA and the manner in which the CrIII is formed.
Hydrolysis and Cytotoxic Properties of Osmium(II)/(III)‐DMSO‐Azole Complexes. Short Communication
Authors: Egger Alexander , Cebrián‐Losantos Berta , Stepanenko Iryna N. , Krokhin Artem A. , Eichinger Rene , Jakupec Michael A. , Arion Vladimir B. , Keppler Bernhard K.
Published: August 2008

The antiproliferative properties of the osmium(II) complexes cis,fac‐[OsIICl2(DMSO)3(L)] and trans,cis,cis‐[OsIICl2(DMSO)2(L)2] (L=1H‐pyrazole, 1H‐imidazole) were studied in three human cancer cell lines, namely 41M (ovary), SK‐BR‐3 (breast), and SW480 (colon). Their activities were compared with those of osmium(III) and ruthenium(III) NAMI‐A type complexes on HT‐29 (colon) and SK‐BR‐3 cancer cell lines. While IC50 values of all the OsII complexes were found to be >1000 μM in all cell lines, Os and Ru‐NAMI‐A type complexes showed remarkable antiproliferative activity. The marginal in vitro cytotoxicity of the OsII compounds is presumably attributed to their resistance to hydrolysis. However, the Os‐NAMI‐A complexes, which are also kinetically stable in aqueous solution, showed reasonable antiproliferative activity in vitro when compared with the analogous Ru compounds and with the OsII‐DMSO‐azole species, indicating that hydrolysis might be not a prerequisite for the antitumor activity of Os‐NAMI‐A type complexes.
Elucidation of the Interactions of an Anticancer Ruthenium Complex in Clinical Trials with Biomolecules Utilizing Capillary Electrophoresis Hyphenated to Inductively Coupled Plasma‐Mass Spectrometry. Short Communication
Authors: Groessl Michael , Hartinger Christian G. , Połeć‐Pawlak Kasia , Jarosz Maciej , Dyson Paul J. , Keppler Bernhard K.
Published: August 2008

The application of capillary electrophoresis (CE) combined with highly sensitive inductively‐coupled‐plasma mass spectrometric (ICP‐MS) detection allows the interactions of metal complexes with biomolecules to be characterized. This technique has been used to provide new insights into the mode of action of the ruthenium‐based anticancer drug candidate indazolium [trans‐tetrachlorobis(1H‐indazole)ruthenate(III)] (KP1019). While the compound binds rapidly and efficiently to serum proteins, especially albumin, its reactivity towards the model DNA compound 2′‐deoxyguanosine 5′‐monophosphate (5′‐dGMP) is moderate.
Action Mechanism of Insulin‐Mimetic Vanadyl–Allixin Complex
Authors: Hiromura Makoto , Sakurai Hiromu
Published: August 2008

In the 21st century, there has been a dramatic worldwide increase in the prevalence of metabolic syndromes, including diabetes mellitus (DM). Several synthetic pharmaceutical agents have been developed and used for the treatment of type‐2 DM; however, these compounds have several problems such as side effects, hypoglycemia, and weight gain. Therefore, new drugs are required for DM therapy. We have proposed that some vanadyl complexes function as potent insulin‐mimetic and antidiabetic agents in type‐1 and type‐2 DM animal models. In this article, we review the possible action mechanism of insulin‐mimetic and antidiabetic vanadyl complexes, focusing on a recently proposed complex, bis(allixinato)oxovanadium(IV), with respect to the insulin‐signaling pathway in cultured adipocytes.
Phosphite‐Derivatized Ruthenium‐Carbohydrate Complexes in the Catalytic Hydration of Nitriles. Short Communication
Authors: Ashraf Shaheen M. , Berger Isabella , Nazarov Alexey A. , Hartinger Christian G. , Koroteev Mikhail P. , Nifant'ev Eduard E. , Keppler Bernhard K.
Published: August 2008

The synthesis of metal complexes with bioligands is one option to introduce chirally defined ligands to catalysts. Herein, the hydration of nitriles to the corresponding carboxamides by use of ruthenium(II) complexes is described, which were obtained by attaching derivatives of the 3,5,6‐bicyclophosphite‐α‐D‐glucofuranoside ligand.
Terpene Conjugates of Diaminedichloridoplatinum(II) Complexes: Antiproliferative Effects in HL‐60 Leukemia, 518A2 Melanoma, and HT‐29 Colon Cancer Cells
Authors: Bernhardt Günther , Biersack Bernhard , Bollwein Susanne , Schobert Rainer , Zoldakova Miroslava
Published: August 2008

Twenty‐eight [6‐(aminomethyl)nicotinate]dichloridoplatinum(II) complexes 1 esterified with various terpene alcohols either directly or via alkyl spacers were tested for antiproliferative activity in human 518A2 melanoma and HL‐60 leukemia cells. Generally, conjugates with menthanes and polycyclic sesquiterpenes attached via propane‐1,2‐diyl spacers were most active. In the melanoma cells, the propane‐1,2‐diyl‐spacered conjugates of (−)‐menthol (1a2′), (+)‐neomenthol (1b2′), (−)‐carvomenthol (1h2′), and (−)‐isolongifolol (1n2′) displayed growth inhibition at IC50<4 μM which is ten times smaller than that of cisplatin. The stationary diamino ligand was also crucial. The (−)‐menthyl ester complexes with 2,3‐diaminopropanoate (9a) and 2,4‐diaminobutanoate (10a) ligands caused a greater and persistent growth inhibition in HT‐29 colon cancer cells upon long‐term exposure when compared to the 6‐(aminomethyl)nicotinate analogue 1a. The cedrenyl ester 1l and the menthoxyisopropyl ester 1a2′ proved most efficacious in all three tumor cell lines. The DNA binding of complexes 1 was assessed by electrophoretic band‐shift experiments and found correlated to the terpene structure but not to the observed antiproliferative activities.
Carotid angioplasty and stenting in octogenarians: Is it safe?
Authors: Henry M. , Henry I. , Polydorou A. , Hugel M.
Published: August 2008

Purpose: Elderly patients have a higher risk of complications in carotid endarterectomy. The aim of the study was to evaluate whether carotid artery stenting (CAS) performed in octogenarians also increases the procedure related risk. Methods: 870 patients (male 626) mean age 70.9 ± 9.3 years underwent 930 CAS for de novo lesions (n = 851) restenoses (n = 54) post radiation (n = 14) inflammatory arteritis (n = 9) post trauma aneurysms (n = 2). Indications for treatment: symptomatic carotid stenosis ≥ 70% (n = 577) or asymptomatic stenosis ≥ 80%. Patients were separated into two age groups: <80 years (749 patients, 806 CAS) and >80 years (121 patients, 124 CAS). 187 CAS performed without protection (N.P−) 6 patients >80 years, 743 with protection (NP+) (occlusion balloon: 334, filters: 404, reversal flow: 6) 118 patients >80 years. Data analysis included neurological complications, death and myocardial infarction (MI) rate at 30 days, anatomical particularities. Technical points will be described depending on the age of the patient. Results: Technical success 804/806 in patients <80 years, 123/124 in patients >80 years (NS). 30 days outcomes: in the patient group <80 years we observed 9 TIA (1.1%) 3 without NP (1.7%) 6 with NP (0.9%), 5 minor strokes (0.6%) 2 without NP (1.1%) 3 with NP (0.5%), 3 major strokes: 2 without NP (1.1%) 1 with NP (0.2%), 5 deaths (0.6%) 2 without NP (1.1%) 3 with NP (0.5%). Death/stroke/MI: 14 (1.8%) 6 without NP (3.3%), 8 with NP (1.3%). In the group >80 years, we observed 2 TIA (1.7%) 1 without NP 1 with NP (0.92%) 1 minor stroke without NP (17%) no major stroke, no death. Death/stroke/MI 1 without NP (17%). Conclusion: CAS can be performed in elderly patients without higher risk than in younger patients. But good indications, a meticulous technique, protection devices are mandatory and some technical points must be pointed out to avoid neurological complications and failures. © 2008 Wiley‐Liss, Inc.
Transient and persistent renal dysfunction are predictors of survival after percutaneous coronary intervention: Insights from the Dartmouth Dynamic Registry
Authors: Brown Jeremiah R. , Malenka David J. , DeVries James T. , Robb John F. , Jayne John E. , Friedman Bruce J. , Hettleman Bruce D. , Niles Nathaniel W. , Kaplan Aaron V. , Schoolwerth Anton C. , Thompson Craig A.
Published: August 2008

Objectives: We sought to determine if transient and persistent elevations in creatinine following percutaneous coronary intervention (PCI) resulted in poor survival. Background: Limited survival data exist that defines the natural survival history of transient and persistent renal dysfunction following interventional PCI cases. Methods: Data were collected prospectively on 7,856 consecutive patients undergoing PCI from January 1, 2000 to July 31, 2006. Ninety‐three patients were excluded due to pre‐PCI dialysis. Patients were stratified into three categories of renal dysfunction: no renal dysfunction from baseline (<0.5 mg/dL increase in creatinine within 48 hr of the procedure), transient renal dysfunction (≥0.5 mg/dL increase in creatinine within 48 hr with return to normal within 2 weeks), and persistent renal dysfunction (≥0.5 mg/dL increase in creatinine without returning to normal within 2 weeks of the procedure). Mortality was determined by comparing with the Social Security Death Master File. Results: Median survival was 3.2 years (mean 3.4). Renal dysfunction occurred in 250 patients (0.5 mg/dL increase in creatinine). Survival was significantly different between patients at 1, 3.2, and 7.5 years (P‐value < 0.001): no renal dysfunction (95%, 88%, 75%), with transient (61%, 42%, 0%), and with persistent (58%, 44%, 36%) renal dysfunction. Patients with transient or persistent renal dysfunction had a twofold–threefold increased risk of 7.5‐year mortality compared with patients with no renal dysfunction. Conclusions: Both transient and persistent postprocedural renal dysfunction are prognostically significant for mortality during extended follow‐up. Renal dysfunction should be closely monitored before and after PCI. © 2008 Wiley‐Liss, Inc.
The PLS model space: the inconsistency persists
Authors: Manne Rolf , Pell Randy J. , Ramos L. Scott
Published: August 2008

In response to the criticisms of Wold et al. 1, the PLS model‐space inconsistency previously described 2 is expressed in latent‐variable language. The inability of the conventional NIPALS PLS algorithm to recover its own decomposition from an already decomposed matrix is also discussed. Copyright © 2008 John Wiley & Sons, Ltd.
Long‐Alkyl‐Chain Quaternary Ammonium Lactate Based Ionic Liquids
Authors: Cybulski Jacek , Wiśniewska Anna , Kulig‐Adamiak Anna , Lewicka Lidia , Cieniecka‐Rosłonkiewicz Anna , Kita Kazimierz , Fojutowski Andrzej , Nawrot Jan , Materna Katarzyna , Pernak Juliusz
Published: August 2008

A new group of quaternary ammonium lactate based ionic liquids have been prepared and characterized. Didecyldimethylammonium (DDA) and benzalkonium (BA) d,l‐ and L‐lactates are air‐stable, hydrophilic, surface‐active salts. They are very effective antibacterial and antifungal agents, especially the DDA lactates, against Streptococcus mutants and Candida albicans. Their activities are comparable or more effective than the original benzalkonium chloride. In addition, they have been shown to be good insect‐feeding deterrents. However, they are poor antifungal agents for wood preservation. The toxicity of the DDA and BA lactates has also been studied and the results are presented in this paper.
Enantioselective Synthesis of [7]Helicene: Dramatic Effects of Olefin Additives and Aromatic Solvents in Asymmetric Olefin Metathesis
Authors: Grandbois Alain , Collins Shawn K.
Published: August 2008

The asymmetric synthesis of [7]helicene was accomplished in good ee (80 %) by kinetic resolution by means of asymmetric olefin metathesis. Three key factors contributed to the success of the kinetic resolution: the use of new Ru‐based olefin metathesis catalysts bearing C1‐symmetric N‐heterocyclic carbene ligands, simple olefins as additives to control the nature of the propagating alkylidene and hexafluorobenzene as a solvent.
Rapid Identification of Common Hexapyranose Monosaccharide Units by a Simple TOCSY Matching Approach
Authors: Gheysen Katelijne , Mihai Camelia , Conrath Karel , Martins José C.
Published: August 2008

Solution NMR spectroscopy is a well established technique for non‐destructive characterization of the structures and conformations of complex oligo‐ and polysaccharides. One of the key experiments involves the use of 2D TOCSY to collect the 1H spins into groups that can be associated with the individual saccharide units that are present in the molecule under study. It is well known that the magnetization transfer rate through the 1H spin system during the TOCSY spin lock period is sensitive to the intervening 3J(H,H) scalar couplings, and therefore also to the saccharide stereochemistry. Here, we have investigated the potential to extract information on the stereochemistry of hexapyranose monosaccharide units directly from TOCSY spectra. Through a systematic experimental investigation of the magnetization transfer initiated from the anomeric 1H resonance in D‐glucose, D‐galactose and D‐mannose it is shown that a 100 ms spin lock time provides optimal spectroscopic discrimination between these three commonly occurring building blocks. A simple matching scheme is proposed as a new tool for rapid attribution of the TOCSY traces originating from the anomeric 1H resonances towards the underlying monosaccharide type. The scheme appears robust with regard to structural variations and fairly tolerant to incidental overlap. Its application provides useful guidance during the subsequent NMR assignment process, as demonstrated with the PS7F polysaccharide from Streptococcus pneumonia. In addition, we show that our scheme affords a clear‐cut distinction between the α‐ and β‐epimers of D‐mannose‐type units, which can be difficult to discriminate by NMR analysis. Application to the N‐glycan 100.2 demonstrates the potential and wide applicability of this new discrimination approach.
Pleasantly surprising clients: a tactic in relationship marketing for building competitive advantage in the financial services sector
Authors: Bergeron Jasmin , Roy Jasmin
Published: August 2008

The turbulent environment in which financial institutions evolve motivates strategic thinking aimed at competitive advantage. Drawing from the literature on relationship marketing, one potentially successful strategy at the level of front line service is for financial advisors to behave in a pleasantly surprising way toward their clients (e.g., acknowledging a family member's birthday; covering a parking expense; giving tickets to an entertainment venue). We examine both antecedents and consequences of clients' perceptions of their advisors behaving in a pleasantly surprising way toward them. Antecedents included advisors' customer orientation, knowledge of client, and sense of humour. Consequences included clients' trust, satisfaction, purchase intentions, and word‐of‐mouth intentions. Several strategic recommendations and research avenues following from these findings are offered. Copyright © 2008 ASAC. Published by John Wiley & Sons, Ltd.
Defective Continuous Hydrogen‐Bond Networks: An Alternative Interpretation of IR Spectroscopy
Authors: Schmidt Diedrich A. , Miki Kazushi
Published: August 2008

We apply our previously developed deconvolution method and interpretation to analyze changes in the OH stretching band [ν(OH) band] of low‐concentration (≤0.2 m) aqueous solutions of NaCl and KCl. We treat these simple, monovalent ions as defects in the hydrogen‐bond network of pure water and quantify the changes in the spectra at low defect concentration with an “order parameter”. Order‐parameter analysis of difference spectra of the two solutions leads to hydration numbers of 7.0±1.0 and 5.9±0.3 for K+ and Na+, respectively. Additionally, we find that changes in the ν(OH) band due to low concentrations of ions result from changes in the topology of the hydrogen‐bond network.
Ab initio Studies on Li4+xTi5O12 Compounds as Anode Materials for Lithium‐Ion Batteries
Authors: Zhong Zhiyong , Ouyang Chuying , Shi Siqi , Lei Minsheng
Published: August 2008

The structural and electronic properties of Li4+xTi5O12 compounds (with 0≤x≤6)—to be used as anode materials for lithium‐ion batteries—are studied by means of first principles calculations. The results suggest that Li4Ti5O12 can be lithiated to the state Li8.5Ti5O12, which provides a theoretical capacity that is about 1.5 times higher than that of the compound lithiated to Li7Ti5O12. Further insertion of lithium species into the Li8.5Ti5O12 lattice results in a clear structural distortion. The small lattice expansion observed upon lithium insertion (about 0.4 % for the lithiated material Li8.5Ti5O12) and the retained [Li1Ti5]16dO12 framework indicate that the insertion/extraction process is reversible. Furthermore, the predicted intercalation potentials are 1.48 and 0.05 V (vs Li/Li+) for the Li4Ti5O12/Li7Ti5O12 and Li7Ti5O12/Li8.5Ti5O12 composition ranges, respectively. Electronic‐structure analysis shows that the lithiated states Li4+xTi5O12 are metallic, which is indicative of good electronic‐conduction properties.
Phonological processing deficits and the acquisition of the alphabetic principle in a severely delayed reader: a case study
Authors: Penney Catherine G. , Drover James , Dyck Carrie
Published: August 2008

At the end of first grade, TM did not know the alphabet and could read no words. He could not tap syllables in words, had difficulty producing rhyming words and retrieving the phonological representations of words, and he could not discriminate many phoneme contrasts. He learned letter‐sound correspondences first for single‐consonant onsets and then later for the final consonant in a word but had difficulty with letter‐sound associations for vowels. TM's ability to select a printed word to match a spoken word on the basis of the initial or final letter and sound was interpreted as evidence of Ehri's phonetic‐cue reading. Using the Glass Analysis method, the authors taught TM to read and he became an independent reader. We discuss how his phonological processing deficits contributed to his reading difficulties. Copyright © 2008 John Wiley & Sons, Ltd.
One‐Step Synthesis of 4,4′‐Dicyano‐2,2′‐bipyridine and Its Bis(4,4′‐di‐tert‐butyl‐2,2′‐bipyridine)ruthenium(II) Complex
Authors: Losse Sebastian , Görls Helmar , Groarke Robert , Vos Johannes G. , Rau Sven
Published: August 2008

This report describes a new route for the fast, economical and effective one‐step synthesis and facile workup procedure of 4,4′‐dicyano‐2,2′‐bipyridine (dnbpy) and its corresponding ruthenium complexes. The complex [(tbbpy)2Ru(dnbpy)](PF6)2 was prepared for the first time (tbbpy = 4,4′‐di‐tert‐butyl‐2,2′‐bipyridine) and the solid‐state molecular structure was investigated with the help of a single‐crystal X‐ray analysis. The influence of the dnbpy ligand on the metal‐to‐ligand charge‐transfer (MLCT) processes of the complex was studied. The compound shows two absorption maxima in the MLCT region of the UV/Vis spectrum at 418 and 510 nm and the emission is 116 nm redshifted in comparison to that of [(tbbpy)3Ru](PF6)2.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis, Structures, and Oxidation of Iridium(III) Alkyl Compounds Containing Thiolate and Dithiolate Ligands
Authors: Chan Ka‐Wang , Sau Yiu‐Keung , Zhang Qian‐Feng , Wong Wai‐Yeung , Williams Ian D. , Leung Wa‐Hung
Published: August 2008

Treatment of [Ir(dtbpy){CH2CMe2Cc6H4(Ir–Cc)}(C6H4tBu‐2)] (1) (dtbpy = 4,4′‐di‐tert‐butyl‐2,2′‐bipyridyl) with the dichalcogenides R2Q2 in refluxing toluene afforded the chalcogenolate‐bridged dinuclear complexes [Ir(dtbpy) {CH2CMe2Cc6H4(Ir–Cc)}]2(μ‐QR)2 [RQ = pTolS (2), PhSe (3)]. Similarly, heating a solution of [Rh(dtbpy){CH2CMe2Cc6H4(Ir–Cc)}(CH2CMe2Ph)] and p‐tolyl sulfide in toluene at reflux gave [Rh(dtbpy){CH2CMe2Cc6H4(Ir–Cc)}]2(μ‐SpTol)2 (4). Treatment of [Ir(dtbpy)(CH2CMe2Ph)Cl]2(μ‐Cl)2 with Na(Sxyl) (xyl = 2,6‐dimethylphenyl) and Na2(S∧S) afforded [Ir(dtbpy)(CH2CMe2Ph)(Sxyl)2]2 (5) and [Ir(dtbpy)(CH2CMe2Ph)(S∧S)]2 {S∧S2– = maleonitriledithiolate (6), toluene‐3,4‐dithiolate (7), benzene‐1,2‐dithiolate (8)}. Oxidation of compound 8 with AgOTf (OTf– = triflate) resulted in dimerization of the bdt2– ligand by S–S bond formation and the isolation of [Ir2(dtbpy)2(CH2Me2Ph)2{(bdt)2}][OTf]2 (9). The solid‐state structures of compounds 2, 3, 4, 7, and 9 were determined. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis and Structural Characterization of Novel Neutral Hexacoordinate Silicon(IV) Complexes with SiS2O2N2 Skeletons
Authors: Metz Stefan , Burschka Christian , Tacke Reinhold
Published: August 2008

A series of novel hexacoordinate silicon(IV) complexes with two tridentate dianionic S,N,O ligands was synthesized, starting from Si(NCO)4. All the compounds synthesized were structurally characterized by single‐crystal X‐ray diffraction and/or solid‐state NMR spectroscopy. In addition, most of the compounds were characterized by solution NMR spectroscopy.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)