bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hidden barriers between knowledge and behavior
Authors: Talcott James A. , Spain Pamela , Clark Jack A. , Carpenter William R. , Do Young Kyung , Hamilton Robert J. , Galanko Joseph A. , Jackman Anne , Godley Paul A. 
Published: March 2007

AbstractBACKGROUNDProstate cancer (PC) mortality is much greater for African American than for Caucasian men. To identify patient factors that might account for some of this disparity, men within 6 months of diagnosis were surveyed about health attitudes and behavior.METHODSUsing Rapid Identification in the North Carolina Cancer Registry, 207 African American and 348 Caucasian recently diagnosed PC patients were identified and surveyed.RESULTSAfrican American men were younger and less often currently married, and had lesser education, job status, and income than Caucasian men (all P < .001). African American men were at no greater distance to medical care, but had less access: poorer medical insurance coverage, more use of public clinics and emergency wards, less continuity with a primary physician, and more often omitted physician visits they felt they needed. They also expressed less trust in physicians. African American men acknowledged their greater risk of PC, accepted greater responsibility for their health, and reported more personal failures that delayed diagnosis. African American men more often requested the tests that diagnosed their cancers, which resulted more often from routinely ordered screening tests for Caucasian men. African American men expressed less interest in nontraditional treatments.CONCLUSIONSDespite lesser education, African American men in North Carolina are aware of their increased risk of cancer, the importance of treatment, and their responsibility for their health. Obstacles to timely diagnosis and appropriate care, including greater physician distrust, appear more likely to arise from reduced access and continuity of medical care arising from their worse socioeconomic position. Cancer 2007 © 2007 American Cancer Society.
Spin‐Orbit Ab Initio Investigation of the Ultraviolet Photolysis of Diiodomethane
Authors: Liu Ya‐Jun , De Vico Luca , Lindh Roland , Fang Wei‐Hai 
Published: March 2007

AbstractThe UV photodissociation (<5 eV) of diiodomethane (CH2I2) is investigated by spin‐orbit ab initio calculations. The experimentally observed photodissociation channels in the gas and condensed phases are clearly assigned by multi‐state second‐order multiconfigurational perturbation theory in conjunction with spin‐orbit interaction through complete active space‐state interaction potential energy curves. The calculated results indicate that the fast dissociations of the first two singlet states of CH2I2 and CH2II lead to geminate‐radical products, CH2I .+I(2P3/2) or CH2I .+ I*(2P1/2). The recombination process from CH2II to CH2I2 is explained by an isomerization process and a secondary photodissociation reaction of CH2II. Finally, the study reveals that spin‐orbits effects are significant in the quantitative analysis of the electronic spectrum of the CH2II species.
Optical Fourier Transform Spectroscopy of Single‐Walled Carbon Nanotubes and Single Molecules
Authors: Korlacki Rafał , Steiner Mathias , Qian Huihong , Hartschuh Achim , Meixner Alfred J. 
Published: March 2007

AbstractWe use two‐beam interferometry in combination with confocal microscopy for Raman and fluorescence studies of spatially isolated single‐walled carbon nanotubes and single dye molecules. We investigate the potential of optical Fourier transform spectroscopy for the spectral characterization of single molecules and molecular nanostructures. We demonstrate that it is possible to obtain the temporal coherence characteristics as well as reliable spectroscopic data of the single photon fluorescence emission of an isolated molecule from one measured interferogram, even though the molecule exhibits intensity fluctuations and spectral jumps.
Nonlinear Optical Properties of Ferrocene‐ and Porphyrin–[60]Fullerene Dyads
Authors: Xenogiannopoulou Evangelia , Medved Miroslav , Iliopoulos Kostas , Couris Stelios , Papadopoulos Manthos G. , Bonifazi Davide , Sooambar Chloè , Mateo‐Alonso Aurelio , Prato Maurizio 
Published: March 2007

AbstractA series of novel [60]fullerene–ferrocene and [60]fullerene–porphyrin dyads, in which a fullerene and an electron donating moiety are attached through a flexible triethylene glycol linker are synthesized and their nonlinear optical (NLO) response studied. Specifically, the third‐order susceptibility χ(3) of all fullerene derivatives are measured in toluene solutions by the optical Kerr effect (OKE) technique using 532 nm, 35 ps laser pulses and their second hyperpolarizability γ are determined. All fullerene dyads studied exhibit enhancement of their NLO response compared to pristine fullerenes which has been attributed to the formation of a charge separated state. All experimentally measured hyperpolarizability γ values are also calculated by the semiempirical methods AM1 and PM3. A good correlation is found between the theoretical and experimental values, suggesting that simple semiempirical methods can be employed for the designing and optimization of the fullerene‐containing dyads displaying improved nonlinear responses.
Structures, Stabilities, and Electronic and Optical Properties of C58Fullerene Isomers, Ions, and Metallofullerenes
Authors: Chen De‐Li , Tian Wei Quan , Feng Ji‐Kang , Sun Chia‐Chung 
Published: March 2007

AbstractThe 1205 classical isomers of fullerene C58, as well as one quasi‐fullerene C58isomer with a heptagonal ring (labeled asCs:hept) have been investigated by the quantum chemical methods PM3, HCTH/3‐21G, and B3LYP/6‐31G(d). IsomerC3v:0001, which has the lowest number of adjacent pentagons, is predicted to be the most stable isomer, but the quasi‐fullerene isomerCs:hept is only 2.50 kcal mol−1higher in energy. Systematic investigations of the electronic properties ofC3v:0001 andCs:hept find that theC3v:0001 isomer has high vertical electron affinity (3.19 eV). The nucleus‐independent chemical shifts (NICS) value at the center ofCs:hept (−5.1 ppm) is more negative than that of C60(−2.8 ppm). The NICS value at the center of the heptagonal ring inCs:hept (−2.5 ppm) indicates weakly aromatic character. In contrast, the C586−and C588−ions of theC3v:0001 andCs:hept geometries possess large aromatic character, with NICS values between −14.0 and −26.2 ppm. To clarify the thermodynamic stabilities of C58isomers at different temperatures, the entropy contributions are taken into account on the basis of the Gibbs energy at the B3LYP/6‐31G(d) level. TheC3v:0001 isomer prevails in a wide range of temperatures, and theCs:hept isomer is also an important component around 2800 K. The IR spectra of C58isomers are simulated to facilitate experimental identification of different isomers. In addition, the electronic spectra and the second‐order hyperpolarizabilities are predicted by ZINDO and the sum‐over‐states model. The static second‐order hyperpolarizability of theC3v:0001 isomer is 96.5 % larger than that of C60, and its second‐order hyperpolarizabilities at external field frequencies are at least nine times larger than those of C60.
Functional Metal Oxide Nanosystems by a Hybrid CVD/Sol–Gel Approach
Authors: Armelao L. , Barreca D. , Bottaro G. , Gasparotto A. , Maragno C. 
Published: March 2007

AbstractThe present contribution is devoted to outlining some recent results from an innovative approach to metal oxide nanosystems. The proposed synthesis pathway is based on three successive steps: i) preparation of a porous xerogel layer (host) via sol–gel (SG); ii) CVD of a guest phase on the above matrix, making it possible to achieve an intimate host/guest intermixing; iii) ex situ thermal treatment under suitable conditions, aimed at tailoring the system properties as a function of the desired application. In particular, the above route has been adopted in two specific cases, LaCoO3 and CeO2–ZrO2 nanostructured thin films, which are acquiring increasing importance in the development of fuel cell technology. The most significant results, obtained by glancing incidence X‐ray diffraction (GIXRD), atomic force microscopy (AFM), X‐ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS), and transmission electron microscopy (TEM), will be critically discussed, emphasizing the achievement of tailored material properties by design.
MOCVD of Hafnium Silicate Films Obtained from a Single‐Source Precusor on Silicon and Germanium for Gate‐Dielectric Applications
Authors: Lemberger M. , Schön F. , Dirnecker T. , Jank M. P. M. , Frey L. , Ryssel H. , Paskaleva A. , Zürcher S. , Bauer A. J. 
Published: March 2007

AbstractIn this work, hafnium silicate layers on Si and Ge wafers for gate dielectric application in metal–oxide–semiconductor devices are investigated. Films are deposited by metal–organic (MO)CVD using the single‐source precursor Hf(acac)2(OSitBuMe2)2. This precursor exhibits good properties in terms of hydrolysis stability, volatility, and deposition. However, precursor decomposition is affected by surface conditions. Films deposited on Si wafers reveal high C contamination (up to 20 at %) and low Si content (up to 20 at %). In contrast, for film deposition on Ge wafers, no C contamination can be detected and Si incorporation is delayed until after about 15 nm HfO2 dielectric growth. Post‐deposition rapid thermal annealing in an O2 atmosphere causes crystallization of deposited films, Si and Ge redistribution in the dielectric, respectively, and interfacial layer growth. However, oxygen annealing was also found to reduce effective oxide thickness (EOT) significantly compared to as‐deposited films, which is attributed to crystallization effects. However, scaling of EOT is limited by that interfacial layer growth. Leakage currents are mainly caused by trap‐related conduction mechanisms. Energy levels of involved traps decrease with increasing crystallization and/or Hf content, and values of 0.5 eV and 1 eV related to Hf and Si bonds, respectively, are obtained.
Development of a multistage classifier for a monitoring system of cell activity based on imaging of chromosomal dynamics
Authors: Gambe Arni E. , Ono Rika Maniwa , Matsunaga Sachihiro , Kutsuna Natsumaro , Higaki Takumi , Higashi Tsunehito , Hasezawa Seiichiro , Uchiyama Susumu , Fukui Kiichi 
Published: March 2007

AbstractBackground:Cell‐based assays utilizing digital image cytometry yield multivariate sets of information measuring the efficacy of medicines/chemicals. The use of a HeLa cell line that expresses a GFP‐Histone‐H1 fusion protein further enhances the performance of these systems, avoiding the use of dyes that may have detrimental influence on cells. Aside from the mitotic index, the distribution of the cell‐cycle phases during mitosis can be used as measures of drug/treatment efficacy. Quantification of these parameters, however, requires skill and is time consuming. The purpose of this research was therefore to create a classifier to be incorporated into a system that can automatically identify the cell‐cycle phases in a given image.Methods:Features based on the shape and texture of the chromosomal regions in images of live HeLa cells were measured and analyzed. Linear discriminant functions were calculated for the eight cell‐cycle phases: interphase, prophase, prometaphase, metaphase, early anaphase, anaphase, telophase and cytokinesis.Results:The multistage linear discriminant classifier developed had an average classification efficiency of 87.30%.Conclusion:We demonstrated the possibility of creating a classifier to discriminate between cell‐cycle phases using shape and texture features of chromosomal regions. The classifier can be fused to an algorithm for image segmentation, forming a system to automatically and rapidly measure the aforementioned parameters. The results can then be collated to constitute an assay assessing the effects of a drug or treatment on mammalian cells. © 2007 International Society for Analytical Cytology
GATA3 controls the expression of CD5 and the T cell receptor during CD4 T cell lineage development
Authors: Ling Kam‐Wing , van Hamburg Jan Piet , de Bruijn Marjolein J. W. , Kurek Dorota , Dingjan Gemma M. , Hendriks Rudolf W. 
Published: March 2007

AbstractThe transcription factor GATA3 is essential at multiple stages of T cell development, including the earliest double‐negative stages, β‐selection and CD4 single‐positive thymocytes. Here, we show that in CD2‐GATA3 transgenic mice, with enforced GATA3 expression driven by the CD2 promoter, thymocytes have reduced levels of CD5, which is a negative regulator of TCR signaling participating in TCR repertoire fine‐tuning. Reduction of CD5 expression was most prominent in CD4+CD8+ double‐positive (DP) cells and was associated with increased levels of the transcription factor E2A. Conversely, GATA3‐deficient DP thymocytes showed consistently higher CD5 levels and defective TCR up‐regulation during their development towards the CD4loCD8lo subpopulation. CD2‐GATA3 transgenic mice carrying the MHC class II‐restricted TCR DO11.10 also manifested decreased CD5 levels. As in these TCR‐transgenic mice reduced CD5 expression cannot result from an effect of GATA3 on repertoire selection, we conclude that enforced GATA3 interferes with the developmentally regulated increase of CD5 levels. Enforced GATA3 expression in DO11.10 transgenic mice was also accompanied by enhanced TCR expression during CD4 positive selection. Because GATA3 is induced by TCR signaling in DP thymocytes, our findings indicate that GATA3 establishes a positive feedback loop that increases TCR surface expression in developing CD4 lineage cells.
Pd Pincer Complex as a Probe To Index the Coordination Ability of Various Ligands
Authors: Minakawa Maki , Takenaka Kazuhiro , Uozumi Yasuhiro 
Published: March 2007

AbstractAn NCN pincer palladium complex was developed as a probe molecule to index the coordination ability of various monodentate ligands. Coordination constants of 27 monodentate ligands (L) with a pincer palladium complex to form complexes of the type ArPd(L)2Cl were determined by 1H NMR spectroscopy. This allowed the coordination ability of a wide variety of ligands, including P‐coordinating ligands (phosphane, phosphite), as well as As‐coordinating AsPh3, and N‐coordinating pyridine, to be indexed. The differential between the highest/lowest coordination constants was 1012. The relative coordination ability is described in a logarithmic manner, log(Keq(L)/Keq), with respect to the value of PPh3 to exhibit high linearity in the Hammett plot.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Modular P‐Chirogenic Aminophosphane‐Phosphinite Ligands for Rh‐Catalyzed Asymmetric Hydrogenation: A New Model for Prediction of Enantioselectivity
Authors: Darcel Christophe , Moulin Dominique , Henry Jean‐Christophe , Lagrelette Michaël , Richard Philippe , Harvey Pierre D. , Jugé Sylvain 
Published: March 2007

AbstractAn original series of P‐chirogenic aminophosphane‐phosphinite (AMPP) ligands has been synthesized from (+)‐ or(–)‐ephedrine in 23 to 61 % overall yields by a versatile three‐step methodology. The AMPP ligands, bearing either one or two P‐chirogenic centers, were used in the form of rhodium complexes for the catalyzed hydrogenation of α‐acetamidocinnamate as a test reaction. Notably, even with AMPP ligands all derived from (+)‐ephedrine, variation of the substituent on a P‐center allowed the phenylalanine derivatives to be obtained in either (S) or (R) absolute configurations, with ee values ranging from 99 % (S) to 88 % (R). The asymmetric induction was analyzed with the aid of X‐ray structures of AMPP complexes, and a new model for the enantioselectivity, taking into consideration the boat conformation and the steric and electronic dissymmetries at the dihydride rhodium‐substrate complex, has been proposed. This model offers an alternative to the quadrant rule, well adapted to the C2‐symmetry ligands and the chair conformation of their complex derivatives. In this work, the model, which schematizes the front side of the complex as a sextant in the direction of the cardinal points, fits with coordination of the substrate by the acetamido and the cinnamyl groups in the north and east (or west) parts, respectively. The enantioselectivity originates from the ligand residues located at the south‐east or south‐west parts of the dihydride rhodium intermediate. Computer modeling on several AMPP‐rhodium complexes with PCModel confirms the proposed predicting model.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
[6+6]Photocycloadditions in Face‐to‐Face Benzo/Pyridazino Substrates – En Route to Azapagodanes
Authors: Mathew Thomas , Tonne Joern , Sedelmeier Gottfried , Grund Clemens , Keller Manfred , Hunkler Dieter , Knothe Lothar , Prinzbach Horst 
Published: March 2007

AbstractIn two specifically constructed rigid, proximate, “face‐to‐face” benzo/pyridazino systems (shortest π,π distances ca. 3 Å) photoequilibration with the photo[6+6]cycloadducts has been established by 254‐nm irradiation (ratios ca. 2:1). The failure to observe such “benzene/heteroarene” photodimers for differently substituted benzo/pyridazino analogues is related to unfavorable UV absorption characteristics of the respective pair of photoisomers as determined by their acceptor/donor substituents. The highly strained photo[6+6]cycloadducts are sufficiently thermally persistent toenable the addition of standard dienophiles, thus openingaccess to novel azapagodane‐type cage molecules. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Selective, Efficient and Functional Group‐Tolerant CuOAc‐Mediated N‐Arylation of 1H‐Indoles and 9H‐Carbazole with Aryl Iodides Under Base‐Free and Ligandless Conditions
Authors: Bellina Fabio , Calandri Chiara , Cauteruccio Silvia , Rossi Renzo 
Published: March 2007

AbstractCuOAc‐Mediated N‐arylation of 1H‐indole derivatives and 1H‐carbazole with aryl iodides under base‐free and ligandless conditions provides the required N‐arylazoles with complete N‐selectivity and in moderate to good yields. The experimental conditions for this new version of the Ullmann reaction allow an unprecedented tolerance of functional groups and facilitate the workup of the reaction mixtures and isolation of the required chemically pure reaction products. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Scandium‐Bipyridine‐Catalyzed, Enantioselective Alcoholysis of meso‐Epoxides
Authors: Tschöp Andreas , Marx Andreas , Sreekanth Anakallil R. , Schneider Christoph 
Published: March 2007

AbstractThe scandium‐bipyridine‐catalyzed ring‐opening of meso‐epoxides with aliphatic alcohols has been studied. Aromatic epoxides were ring‐opened with >90 % ee furnishing valuable 1,2‐diol monoethers in typically good yields whereas aliphatic epoxides gave rise to moderate enantioselectivities. The catalyst loading may be lowered to 2–5 mol‐% with only marginal effects on yield and enantioselectivity. A strong positive non‐linear effect was observed pointing to aggregation phenomena of the chiral catalyst.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
C–O Insertion Reaction of Nucleophilic Carbene: Facile Synthesis of Isochromane Cage
Authors: Poliakov Dmytro , Shevchenko Igor 
Published: March 2007

AbstractBis(diisopropylamino)carbene easily reacts with phthalic anhydride to give quantitatively an isochromane derivative which undergoes unusual isomerization with the formation of a strained azetidine ring and a very short intramolecular hydrogen bond. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Electrochemical Sensing of DNA Using Gold Nanoparticles
Authors: Castañeda M. T. , Alegret S. , Merkoçi A. 
Published: March 2007

AbstractThe electrochemical properties of gold nanoparticles (AuNPs) have led to their widespread use as DNA labels. This fact has improved the design strategies for the electrochemical detection of DNA through hybridization event monitoring. The reported DNA hybridization detection modes are based on either AuNP detection after dissolving or the direct detection of the AuNP/DNA conjugates anchored onto the genosensor surface. Various enhancement strategies have been reported so as to improve the detection limit. Most are based on catalytic deposition of silver onto AuNP. Other strategies based on the use of AuNPs as carrier/amplifier of other labels will be also revised. The developed techniques are characterized by sensitivities and specificities that enable further applications of the developed DNA sensors in several fields.
Adaptive modulation over nonlinear time‐varying channels
Authors: Alasady Hisham , Ibnkahla Mohamed 
Published: March 2007

AbstractThis paper proposes a simple adaptive modulation scheme over nonlinear time‐varying channels equipped with High Power Amplifiers (HPAs). The paper includes the probability of Bit Error Rate (BER) analysis of M‐QAM transmission over nonlinear channels, which is the key factor in designing adaptive modulation. The paper includes performance comparison of adaptive modulation over linear and nonlinear channel with different normalised Doppler frequencies. The analysis is supported with simulation results. Results show that the nonlinearity affects the overall system performance; and the adaptive modulation scheme allows significant spectral improvement over the classical non‐adaptive system. Copyright � 2007 John Wiley & Sons, Ltd.
A ‘divide‐and‐conquer’ spatial and temporal multiscale method for transient convection–diffusion–reaction equations
Authors: Gravemeier Volker , Wall Wolfgang A. 
Published: March 2007

AbstractA multiscale method for the numerical solution of transient convection–diffusion–reaction equations is proposed in the present paper. Two main goals have led to the development of the present method: a desired independence of any heuristic parameter such as the stabilization parameter in stabilized methods and a desire for a consistent multiscale approach in space and time. The method is constituted by solution approaches on a coarse‐ and a fine‐scale level and by inter‐scale operators for data transfer between those two levels. A particular feature of the method is that no large matrix system has to be solved. The results from three numerical test cases show that for both problematic flow regimes, that is, the regime of dominant convection and the regime of dominant convection and absorption, the present method provides completely stable solutions, which are not achieved by standard stabilized methods, particularly for the later regime. A still to be noted current shortcoming of the proposed method reveals itself in a too smooth resolution of regions with a sharp gradient in the solution field. Copyright © 2007 John Wiley & Sons, Ltd.
Development of a local MQ‐DQ‐based stencil adaptive method and its application to solve incompressible Navier–Stokes equations
Authors: Shu C. , Shan Y. Y. , Qin N. 
Published: March 2007

AbstractIn this paper, a local stencil adaptive method is presented, which is designed for solving computational fluid dynamics (CFD) problems with curved boundaries accurately. A local multiquadric‐differential quadrature (MQ‐DQ) method is used to discretize the governing equations, taking advantage of its meshless nature. The present method bears the properties of both local MQ‐DQ method and local stencil adaptive method and is thus named the local MQ‐DQ‐based stencil adaptive method. Two test problems with curved boundaries are solved to investigate the performance of this solution‐adaptive method. The numerical results indicate that the proposed method is effective and efficient by combining the advantages of meshless property for complex geometries and local adaptation for accuracy improvement. Copyright © 2007 John Wiley & Sons, Ltd.