bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxazole‐Bridged Combretastatin A Analogues with Improved Anticancer Properties
Authors: Biersack Bernhard , Effenberger Katharina , Schobert Rainer , Ocker Matthias 
Published: January 2010

AbstractThree new oxazole‐bridged combretastatin A analogues with additional functional groups at the B‐ring [‐SMe, ‐OH, p‐quinone] were tested for antiproliferative activity and specificity on human HL‐60 leukemia, 518A2 melanoma, and colon carcinomas HCT‐116 (wt)/(p53−/−) and HT‐29 cells. While all oxazoles, except quinone 8, were efficacious against HCT‐116 cells at submicromolar IC50 values (48 h incubation), only thioanisole 5 achieved this potency in combretastatin‐refractory HT‐29 cells by significant upregulation of p21cip1/waf1 associated with an S/G2 cell‐cycle arrest.
Magnetically Deformable Liquid Mirrors from Surface Films of Silver Nanoparticles
Authors: Ritcey Anna M. , Borra Ermanno 
Published: January 2010

AbstractThis article describes the development of a magnetically deformable mirror composed of a reflective monolayer of silver nanoparticles deposited at the surface of a ferrofluid. In order to be commercially competitive, this mirror must surpass existing technologies with respect to optical performance. Several important characteristics of the mirror, including reflectivity, deformability and long term stability, are determined in large part by the constituent chemical components. This article describes recent progress in the optimisation of these components. As outlined below, several important objectives have been met and the mirror has clearly passed the proof‐of‐concept stage. Challenges, however, remain, particularly with respect to the stability of the surface layer of silver nanoparticles that imparts reflectivity to the mirror. This interdisciplinary project underscores the role that fundamental colloid and surface chemistry can play in the development of a unique optical element.
Transesterification of Triglycerides Using Nitrogen‐Functionalized Carbon Nanotubes
Authors: Villa Alberto , Tessonnier Jean‐Philippe , Majoulet Olivier , Su Dang Sheng , Schlögl Robert 
Published: January 2010

AbstractNitrogen‐functionalized carbon nanotubes were synthesized by grafting amino groups to the surface of the nanotubes. The nanotubes exhibited promising results in the base‐catalyzed liquid phase transesterification of glyceryl tributyrate with methanol, which is a model reaction for the production of biodiesel. The concentration of the active sites and the reaction parameters, such as temperature and glyceryl tributyrate to methanol ratio, were shown to significantly affect catalytic performance. The grafting technique employed allowed for design and control of the active sites. As a consequence, it was possible to design a nitrogen‐functionalized carbon nanotube catalyst with a few strong, basic groups. This might be of interest for carbohydrate conversion reactions where strong basic sites are required but the pH of the solution should remain mild to avoid the degradation of the reactants and/or products.
Tracing Laser‐Induced Dielectric Breakdown in Solids
Authors: Rethfeld B. , Krutsch H. , Hoffmann D.H.H. 
Published: January 2010

AbstractWe model the transient free electron density in laser‐irradiated dielectrics with a kinetic approach. The internal electrical field responsible for the strength and mechanisms of photon absorption is calculated self‐consistently in dependence on the increasing free electron density. The results show the threshold behavior of the absorbed energy, responsible for dielectric breakdown (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Shell Structure of Confined Charges at Strong Coupling
Authors: Wrighton J. , Dufty J.W. , Bonitz M. , Kählert H. 
Published: January 2010

AbstractA theoretical description of shell structure for charged particles in a harmonic trap is explored at strong coupling conditions of Γ = 50 and 100. The theory is based on an extension of the hypernetted chain approximation to confined systems plus a phenomenological representation of associated bridge functions. Predictions are compared to corresponding Monte Carlo simulations and quantitative agreement for the radial density profile is obtained (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ionization Cross Section for Strongly Coupled Partially Ionized Hydrogen Plasma with Arbitrary Ionization Degree
Authors: Baimbetov F.B. , Kudyshev Zh.A. 
Published: January 2010

AbstractAs it has been shown in previous works, it is very important to take into account the influence of plasma surrounding during ionization process consideration. The present work is the generalization of previous works to arbitrary ionization degree. The ionization cross section is calculated with help of pseudopotential model of plasma particles interaction, which takes into account correlation effects. The electron impact ionization cross section is calculated with account of phase shifts of scattered electron within quasiclassic approach. It is compared with results of previous works, experimental data and suitable results presented by other authors (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical Resistivity in Warm Dense Plasmas Beyond the Average‐Atom Model
Authors: Pain J. C. , Dejonghe G. 
Published: January 2010

AbstractThe exploration of atomic properties of strongly coupled partially degenerate plasmas, also referred to as warm dense matter, is important in astrophysics, since this thermodynamic regime is encountered for instance in Jovian planets' interior. One of the most important issues is the need for accurate equations of state and transport coefficients. The Ziman formula has been widely used for the computation of the static (DC) electrical resistivity. Usually, the calculations are based on the continuum wavefunctions computed in the temperature and density‐dependent self‐consistent potential of a fictive atom, representing the average ionization state of the plasma (average‐atom model). We present calculations of the electrical resistivity of a plasma based on the superconfiguration (SC) formalism. In this modeling, the contributions of all the electronic configurations are taken into account. It is possible to obtain all the situations between the two limiting cases: detailed configurations (a super‐orbital is a single orbital) and detailed ions (all orbitals are gathered in the same superorbital). The ingredients necessary for the calculation are computed in a self‐consistent manner for each SC, using a density‐functional description of the electrons. Electron exchange‐correlation is handled in the localdensity approximation. The momentum transfer cross‐sections are calculated by using the phase shifts of the continuum electron wavefunctions computed, in the potential of each SC, by the Schrödinger equation with relativistic corrections (Pauli approximation). Comparisons with experimental data are also presented (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Energy Relaxation Study for Warm Dense Matter Experiments
Authors: Schlanges M. , Bornath Th. , Vorberger J. , Gericke D.O. 
Published: January 2010

AbstractWe present a quantum kinetic description of temperature relaxation in warm dense matter. Starting from a general balance equation, we show how kinetic, correlation, and exchange energies of electrons and ions are exchanged during the equilibration towards equilibrium. Different approximations for the electron‐ion energy transfer rates are discussed. The approach is.nally applied to heated solids and shock‐compressed matter as investigated in recent warm dense matter experiments to estimate the minimum time needed between pump and probe pulses when investigating equilibrium properties (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A longitudinal study of emotion regulation and anxiety in middle childhood: Associations with frontal EEG asymmetry in early childhood
Authors: Hannesdóttir Dagmar Kr. , Doxie Jacquelyn , Bell Martha Ann , Ollendick Thomas H. , Wolfe Christy D. 
Published: January 2010

AbstractWe investigated whether brain electrical activity during early childhood was associated with anxiety symptoms and emotion regulation during a stressful situation during middle childhood. Frontal electroencephalogram (EEG) asymmetries were measured during baseline and during a cognitive control task at 4 ½ years. Anxiety and emotion regulation were assessed during a stressful situation at age 9 (speech task), along with measures of heart rate (HR) and heart rate variability (HRV). Questionnaires were also used to assess anxiety and emotion regulation at age 9. Results from this longitudinal study indicated that children who exhibited right frontal asymmetry in early childhood experienced more physiological arousal (increased HR, decreased HRV) during the speech task at age 9 and less ability to regulate their emotions as reported by their parents. Findings are discussed in light of the associations between temperament and development of anxiety disorders. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 52:197–204, 2010
Mechanistic Insights into Copper‐Catalyzed Michael Reactions
Authors: Pérez Elisabet , Moreno‐Mañas Marcial , Sebastián Rosa María , Vallribera Adelina , Jutand Anny 
Published: January 2010

AbstractThe mechanism of the Michael reaction between 2‐(ethoxycarbonyl)cyclopentanone (2) and methyl vinyl ketone (3) catalyzed by the copper(II) salt [Cu(5‐tBu‐Sal)2] (1) has been investigated in toluene. The kinetics of the reaction of the catalyst 1 with the oxo ester 2 has been investigated by UV/Vis spectroscopy. It has been established that [Cu(5‐tBu‐Sal)2] (1) reacts with 2 in a first‐order reaction, which is retarded by 5‐tBu‐Sal‐H (6), formed in the reaction after the reversible dissociation of [Cu(5‐tBu‐Sal)2] to [Cu(5‐tBu‐Sal)]+ and 5‐tBu‐Sal– and the subsequent reversible deprotonation of 2 by 5‐tBu‐Sal–. The formation of the mixed complex [Cu(5‐tBu‐Sal)(enolate‐2)] (5) is proposed and has been characterized by cyclic voltammetry. The rate constant for the overall reaction leading to [Cu(5‐tBu‐Sal)(enolate‐2)] (5) has been determined. The reaction of the mixed complex 5 with methylvinyl ketone (3), investigated by cyclic voltammetry, is proposed as the rate‐determining step.
Synthesis and Evaluation of Lipophilic Aza‐C‐glycosides as Inhibitors of Glucosylceramide Metabolism
Authors: Wennekes Tom , van den Berg Richard J. B. H. N. , Boltje Thomas J. , Donker‐Koopman Wilma E. , Kuijper Bastiaan , van der Marel Gijsbert A. , Strijland Anneke , Verhagen Carlo P. , Aerts Johannes M. F. G. , Overkleeft Herman S. 
Published: January 2010

AbstractThe structure–activity relationship of lipophilic aza‐C‐glycosides as inhibitors of the three enzymes of glucosylceramide metabolism is investigated. A library of β‐aza‐C‐glycosides was synthesized with variations in N‐alkylation and the linker length/type to the lipophilic moiety. A cross‐metathesis reaction was used to prepare a second library of α‐aza‐C‐glycosides with D‐gluco, L‐ido and D‐xylo iminosugar cores possessing analogous linker variations. Evaluation of both libraries did not reveal a potent or selective inhibitor of glucosylceramide synthase. However, β‐aza‐C‐glycoside 43 was found to be a selective inhibitor of β‐glucosidase 2. The α‐aza‐C‐glycosides – especially with a D‐xylo core (e.g. 80) – proved to be very potent and selective inhibitors of glucocerebrosidase.
Facile Solid‐Phase Synthesis of AICAR 5′‐Monophosphate (ZMP) and Its 4‐N‐Alkyl Derivatives
Authors: Oliviero Giorgia , D'Errico Stefano , Borbone Nicola , Amato Jussara , Piccialli Vincenzo , Piccialli Gennaro , Mayol Luciano 
Published: January 2010

AbstractWe report herein a facile, solid‐phase synthesis of 5‐amino‐1‐β‐D‐ribofuranosylimidazole‐4‐carboxamide‐5′‐monophosphate (ZMP), a biosynthetic precursor of purine nucleotides, as well as a small collection of its 4‐N‐alkyl derivatives. The very difficult, direct, chemical phosphorylation of 5‐amino‐1‐β‐D‐ribofuranosylimidazole‐4‐carboxamide (AICAR) was circumvented by installing a suitable, fully protected, phosphate group on the 5′‐position of N‐1‐(2,4‐dinitrophenyl)inosine, connected to the solid support through the 2′,3′‐positions, prior to the purine degradation, which led to the 5‐amino‐imidazole‐4‐carboxamide moiety. A plausible reaction mechanism for the formation of the ZMP imidazole was also reported.
An Electrochemical DNA Biosensor for the Detection of the Apa I Polymorphism in the Vitamin D Receptor Gene Using Meldola's Blue as a Hybridization Indicator
Authors: Aladag Nilay , Ozkan‐Ariksoysal Dilsat , Gezen‐Ak Duygu , Yilmazer Selma , Ozsoz Mehmet 
Published: January 2010

AbstractElectrochemical detection of nucleic acid base mismatches related to Apa I single nucleotide polymorphism (SNP) in the vitamin D receptor gene was performed successfully using 7‐dimethyl‐amino‐1,2‐benzophenoxazinium salt (Meldola's blue, MDB) with 10.9 pmol/100 μL of detection limit. MDB reduction signals obtained from probe, mismatch(probe‐SNP containing target) and hybrid(probe‐target) modified pencil graphite electrode(PGE) increased respectively. The sensor was able to clearly distinguish perfect match from mismatch DNA in a 30 min. detection time. Several factors affecting on the hybridization and indicator response are studied to maximize sensitivity and selectivity. The advantages of the biosensor are discussed in comparison with previous electrochemical assays for DNA hybridization.
A Biosensor Composed of Glucose Oxidase‐Containing Liposomes and MnO2‐Based Layered Nanocomposite
Authors: Yoshimoto Makoto , Iida Chihiro , Kariya Asuka , Takaki Noriyuki , Nakayama Masaharu 
Published: January 2010

AbstractGlucose oxidase (GOD) was encapsulated in liposomes, and then the GOD‐containing liposomes were immobilized to a MnO2‐based multilayered nanocomposite film grown electrochemically. Oxidation of glucose took place on the encapsulated GOD in the manganese oxide film, and the generated H2O2 molecules were oxidized catalytically at high valent Mn sites (4+) in the film. Anodic currents due to reoxidation of the reduced Mn ions (3+) were in proportion to the concentration of glucose from 19.6 to 107.1 mM. Such a simple construction of biosensor is applicable to a variety of combinations of liposomal enzymes and substrates.
Recent developments in peptide stereoisomer separations by capillary electromigration techniques
Authors: Scriba Gerhard K. E. 
Published: January 2010

AbstractThe stereochemistry of peptides determines their physicochemical and biological activities. Thus, analytical methods that are able to discriminate between peptide stereoisomers are important. As peptides are typically hydrophilic compounds, many methods for the separation of peptide diastereomers and enantiomers have been developed by capillary electromigration techniques. Moreover, peptide enantiomers displayed unique migration behavior such as a pH‐dependent change of the enantiomer migration order in CD‐mediated enantioseparations in CE making them ideal compounds to study mechanistic effects of enantioseparations. The present short review summarizes recent developments in the separation of stereoisomers of peptide and peptidomimetics by capillary electromigration techniques. Moreover, recent NMR and molecular modeling studies as well as investigation on the effect of buffer additives on complex formation will be discussed as attempts to understand mechanistic aspects of peptide enantioseparations and to analyze the structure of peptide‐CD complexes.
Membrane proteins and proteomics: Love is possible, but so difficult
Authors: Rabilloud Thierry 
Published: January 2010

AbstractDespite decades of extensive research, the large‐scale analysis of membrane proteins remains a difficult task. This is due to the fact that membrane proteins require a carefully balanced hydrophilic and lipophilic environment, which optimum varies with different proteins, while most protein chemistry methods work mainly, if not only, in water‐based media. Taking this review [Santoni, Molloy and Rabilloud, Membrane proteins and proteomics: un amour impossible? Electrophoresis 2000, 21, 1054–1070] as a pivotal paper, the current paper analyzes how the field of membrane proteomics exacerbated the trend in proteomics, i.e. developing alternate methods to the historical two‐dimensional electrophoresis, and thus putting more and more pressure on the mass spectrometry side. However, in the case of membrane proteins, the incentive in doing so is due to the poor solubility of membrane proteins. This review also shows that in some situations, where this solubility problem is less acute, two‐dimensional electrophoresis remains a method of choice. Last but not least, this review also critically examines the alternate approaches that have been used for the proteomic analysis of membrane proteins.
Electrophoresis of DNA in agarose gels, polyacrylamide gels and in free solution
Authors: Stellwagen Nancy C. 
Published: January 2010

AbstractThis review describes the electrophoresis of curved and normal DNA molecules in agarose gels, polyacrylamide gels and in free solution. These studies were undertaken to clarify why curved DNA molecules migrate anomalously slowly in polyacrylamide gels but not in agarose gels. Two milestone papers are cited, in which Ferguson plots were used to estimate the effective pore size of agarose and polyacrylamide gels. Subsequent studies on the effect of the electric field on agarose and polyacrylamide gel matrices, DNA interactions with the two gel matrices, and the effect of curvature on the free solution mobility of DNA are also described. The combined results suggest that the anomalously slow mobilities observed for curved DNA molecules in polyacrylamide gels are primarily due to preferential interactions of curved DNAs with the polyacrylamide gel matrix; the restrictive pore size of the matrix is of lesser importance. In free solution, DNA mobilities increase with increasing molecular mass until leveling off at a plateau value of (3.17±0.01)×10−4 cm2/V s in 40 mM Tris‐acetate‐EDTA buffer at 20°C. Curved DNA molecules migrate anomalously slowly in free solution as well as in polyacrylamide gels, explaining why the Ferguson plots of curved and normal DNAs containing the same number of base pairs extrapolate to different mobilities at zero gel concentration.
Electrophoretic sample stacking
Authors: Gebauer Petr , Boček Petr 
Published: January 2010

AbstractSample stacking is a tool that is in daily use in electrophoresis in order to enhance the efficiency and sensitivity of analyses. The application of sample stacking is described by numerous diverse practical procedures and numerous different names. This contribution shows that the present intricate situation is a heritage of the history where chromatographic and isotachophoretic approaches have been applied more or less independently. Further, this contribution shows that a unified view is possible and a general approach based on a frame with moving self‐sharpening boundary may provide the required fundamental theory and criteria needed for successful application of sample stacking. Finally, the prospects of sample stacking are discussed.
Chiral separations by CE employing CDs
Authors: Fanali Salvatore 
Published: January 2010

AbstractThis paper summarizes the history of chiral separations done by using electromigration methods with CDs. Several enantioresolution mechanisms and a wide number of chiral selectors have been applied to the separation of optical isomers by CE. Among them inclusion‐complexation with CDs or their derivatives played a very important role in CE. Since the beginning our group was involved in studying method optimization for enantiomer resolution by using these chiral selectors. One of our publications was the basis for further development in the field, at least for us. New chiral selectors, development of theory, new methodological approaches and a wide number of practical applications are the main results achieved in the last almost 25 years using CE as an enantioseparative technique.
Dynamic computer simulations of electrophoresis: Three decades of active research
Authors: Thormann Wolfgang , Caslavska Jitka , Breadmore Michael C. , Mosher Richard A. 
Published: January 2010

AbstractDynamic models for electrophoresis are based upon model equations derived from the transport concepts in solution together with user‐inputted conditions. They are able to predict theoretically the movement of ions and are as such the most versatile tool to explore the fundamentals of electrokinetic separations. Since its inception three decades ago, the state of dynamic computer simulation software and its use has progressed significantly and Electrophoresis played a pivotal role in that endeavor as a large proportion of the fundamental and application papers were published in this periodical. Software is available that simulates all basic electrophoretic systems, including moving boundary electrophoresis, zone electrophoresis, ITP, IEF and EKC, and their combinations under almost exactly the same conditions used in the laboratory. This has been employed to show the detailed mechanisms of many of the fundamental phenomena that occur in electrophoretic separations. Dynamic electrophoretic simulations are relevant for separations on any scale and instrumental format, including free‐fluid preparative, gel, capillary and chip electrophoresis. This review includes a historical overview, a survey of current simulators, simulation examples and a discussion of the applications and achievements of dynamic simulation.
Proteomics in the study of the molecular taxonomy and epidemiology of bacterial pathogens
Authors: Cash Phillip 
Published: January 2010

AbstractThe ability to discriminate bacterial isolates is important for a number of areas of research in Medical Microbiology, particularly in defining bacterial taxonomy and monitoring transmission in epidemiological investigations. Molecular techniques capable of typing bacteria at the level of the genome and proteome are now widely used for these investigations. This review considers two electrophoretic methods for typing bacteria on the basis of their proteomes, namely 1‐D SDS‐PAGE and 2‐DE. The application of these two techniques for bacterial typing is described with reference to two publications that appeared in Electrophoresis [Costa, Electrophoresis 1990, 11, 382–391 and Cash et al., Electrophoresis 1997, 18, 1472–1482]. Even though these methods have been used for nearly 20 years to differentiate bacterial isolates they remain key technologies in proteome‐based typing methods. The developments that have arisen from the two key papers are described in order to highlight the advantages and disadvantages in typing bacteria at the level of their proteomes. Some of the difficulties associated with electrophoretic typing methods can be overcome by using non‐gel proteomic methods based on MS to provide improved sensitivity and specificity. The application of proteomic methods to investigate bacterial taxonomy, epidemiology and pathogenesis in general has significant potential in furthering our understanding of infectious diseases.
Affinity in Electrophoresis
Authors: Heegaard Niels H. H. 
Published: January 2010

AbstractThe journal Electrophoresis has greatly influenced my approaches to biomolecular affinity studies. The methods that I have chosen as my main tools to study interacting biomolecules – native gel and later capillary zone electrophoresis – have been the topic of numerous articles in Electrophoresis. Below, the role of the journal in the development and dissimination of these techniques and applications reviewed. Many exhaustive reviews on affinity electrophoresis and affinity CE have been published in the last few years and are not in any way replaced by the present deliberations that are focused on papers published by the journal.