bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biocompatible Mn2+‐doped carbonated hydroxyapatite thin films grown by pulsed laser deposition
Authors: György E. , Toricelli P. , Socol G. , Iliescu M. , Mayer I. , Mihailescu I. N. , Bigi A. , Werckman J. 
Published: September 2004

AbstractMn2+‐doped carbonated hydroxyapatite (Mn‐CHA) thin films were obtained by pulsed laser deposition on Ti substrates. The results of the performed complementary diagnostic techniques, X‐ray diffraction, infrared spectroscopy, X‐ray photoelectron spectroscopy, and energy dispersive X‐ray spectroscopy investigations indicate that the films are crystalline with a Ca/P ratio of about 1.64–1.66. The optimum conditions, when nearly stoichiometric crystalline thin films were deposited, were found to be 10 Pa oxygen pressure, 400°C substrate temperature, and postdeposition heat treatment in water vapors at the same substrate temperature. The films were seeded with L929 fibroblast and hFOB1.19 osteoblast cells and subjected to in vitro tests. Both fibroblast and osteoblast cells have a good adherence on the Mn‐CHA film and on the Ti or polystyrene references. Proliferation and viability tests showed that osteoblast cells growth on Mn‐CHA–coated Ti was enhanced as compared to uncoated pure Ti surfaces. Caspase‐1 activity was not affected significantly by the material, showing that Mn‐CHA does not induce apoptosis of cultured cells. These results demonstrate that Mn‐CHA films on Ti should provoke a faster osteointegration of the coated implants as compared to pure Ti. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 353–358, 2004
On partitions of {1,…,2m+ 1}\{k} into differencesd,…,d+m− 1: Extended Langford sequences of large defect
Authors: Linek Vaclav , Mor Shai 
Published: September 2004

AbstractIt is shown that form= 2d− 1, 2d, 2d+ 1, andd≥ 1, the set {1, 2,…, 2m+ 2}, − {2,k} can be partitioned into differencesd,d+ 1,…,d+m− 1 whenever (m,k) ≡ (0,0), (1,d+ 1), (2, 1), (3,d) (mod (4,2)) and (d,m,k) ≠ (1,1,3), (2,3,7) (where (x,y) ≡ (u,ν) mod (m,n) iffx≡u(modm) andy≡ν(modn)). It is also shown that ifm≥ 2d− 1 andm∉ [2d+ 2, 8d− 5], then the set {1, 2, …, 2m+ 1} − {k} can be partitioned into differencesd,d+ 1,…,d+m− 1 whenever (m,k) ≡ (0, 1), (1,d), (2,0), (3,d+ 1) mod (4,2). Finally, ford= 4 we obtain a complete result for when {1,…,2m+ 1} − {k} can be partitioned into differences 4,5,…,m+ 3. © 2004 Wiley Periodicals, Inc.
There exist non‐isomorphic STS(19) with equivalent point codes
Authors: Kaski Petteri , Östergård Patric R. J. 
Published: September 2004

AbstractThe rows of a point by block incidence matrix of a design can be used to generate a code, the point code of the design. It is known that binary point codes of non‐isomorphic Steiner triple systems of order hr STS(v), are inequivalent whenv ≤ 15, but whether this also holds for higher orders has been open. In the current paper, an example of two non‐isomorphic STS(19) with equivalent point codes is presented. © 2004 Wiley Periodicals, Inc.
Hormonal regulation of the Grb14 signal modulator and its role in cell cycle progression of MCF‐7 human breast cancer cells
Authors: Kairouz Rania , Parmar Jayamala , Lyons Ruth J. , Swarbrick Alexander , Musgrove Elizabeth A. , Daly Roger J. 
Published: September 2004

AbstractGrowth factor receptor bound (Grb)14 is a member of the Grb7 family of src homology (SH)2 domain‐containing proteins. These proteins perform both adaptor and modulatory roles in receptor tyrosine kinase (RTK) signaling, although their regulation is poorly understood. In this study, a positive correlation between Grb14 protein expression and ERα status in breast cancer cell lines led us to investigate regulation of Grb14 by estradiol and insulin, which synergize in the regulation of breast cancer cell proliferation. In MCF‐7 cells maintained in charcoal‐stripped serum, Grb14 expression was downregulated by estradiol and increased by the pure anti‐estrogen ICI 182780. Under serum‐free conditions, insulin enhanced Grb14 expression but this effect was repressed by estradiol when both hormones were used in combination. Using a system in which c‐Myc induction drives cell cycle progression independently of estradiol, we demonstrated that Grb14 regulation was specific to estradiol treatment. Finally, we demonstrated a novel functional role for Grb14 whereby its overexpression inhibited not only insulin‐ but also estrogen‐induced cell cycle progression. This was associated with decreased extracellular signal‐regulated kinase (Erk)1/2 activation in insulin‐stimulated Grb14‐overexpressing cells. These data represent the first demonstration of regulation of Grb14 expression levels in response to hormonal stimuli, and are consistent with its role as a repressor of insulin signaling where it is induced as a negative feedback mechanism. A role for Grb14 is also shown in estrogen/insulin crosstalk since estradiol blocks the insulin‐induced induction of this protein. © 2004 Wiley‐Liss, Inc.
Gene therapy for malignant glioma using Sindbis vectors expressing a fusogenic membrane glycoprotein
Authors: Zhang Jie , Frolov Ilya , Russell Stephen J. 
Published: September 2004

AbstractBackgroundMalignant glioma has a dismal prognosis. It was previously shown that glioma cells are efficiently killed when they express a gene coding for a hyperfusogenic mutant of the gibbon ape leukemia virus envelope glycoprotein (GALV.fus). However, production of viral vectors expressing GALV.fus has proven problematic because the transgene is toxic to vector‐producing cells of human origin. We reasoned that Sindbis‐virus‐based vectors might be ideal for GALV.fus gene transfer because high‐titer stocks can easily be generated in hamster cells and Sindbis virus efficiently infects human tumor cells through the high‐affinity 67 kDa laminin receptor. In addition, Sindbis virus nonstructural proteins are potent inducers of apoptosis, and Sindbis vector RNAs expressing fusogenic viral proteins have been shown to spread from cell‐to‐cell in membrane‐formed infectious particles.MethodsSindbis virus replicon‐containing particles were generated by co‐transfecting vector and helper RNAs into baby hamster kidney (BHK‐21) cells. Packaged beta‐galactosidase and GALV.fus expressing Sindbis vectors were used to infect glioma cell lines, which were then compared for syncytial cytopathic effect, cell killing, and release of infectious virus‐like particles containing the vector genome. Finally, the efficacy of GALV.fus and beta‐galactosidase Sindbis vectors was compared in an orthotopic intracerebral U87 glioma xenograft model in nude mice.ResultsHigh‐titer stocks (>109 infectious units (iu)/ml) of the GALV.fus and beta‐galactosidase vectors were obtained. Glioma cells infected with the GALV.fus vector formed large syncytia which died rapidly by apoptosis and released infectious membrane‐formed particles that could transfer vector genomes to uninfected cells. The GALV.fus vector had significantly greater antitumor therapeutic potency than the β‐galactosidase vector in the U87 glioma xenograft model.ConclusionsSindbis vectors expressing GALV.fus can be packaged into infectious viral particles to high titer, they exhibit potent bystander cytopathic potential and are active against U87 glioma xenografts. Sindbis‐virus‐based replicons appear to be efficient vector systems for delivery and expression of fusogenic membrane glycoproteins. Copyright © 2004 John Wiley & Sons, Ltd.
Inhibitory effects of Hibiscus sabdariffa L extract on low‐density lipoprotein oxidation and anti‐hyperlipidemia in fructose‐fed and cholesterol‐fed rats
Authors: Chen Chang‐Che , Chou Fen‐Pi , Ho Yung‐Chyan , Lin Wea‐Lung , Wang Chin‐Pin , Kao Erl‐Shyh , Huang An‐Chung , Wang Chau‐Jong 
Published: September 2004

AbstractHibiscus sabdariffa L extract (HSE) is an aqueous extract of Hibiscus sabdariffa L flowers that is used as a local soft drink and medical herb in Taiwan. Oxidation of low‐density lipoprotein (LDL) has been shown to increase the incidence of atherosclerosis. In this study, we determined the antioxidative activity of HSE on LDL oxidation by examining relative electrophoretic mobilities (REM) and thiobarbituric acid‐reactive substances (TBARS). The data revealed an inhibitory effect of HSE on Cu2+‐mediated REM and TBARS. HSE exhibited a remarkable ability to reduce cholesterol degradation and ApoB fragmentation. Overall, HSE showed a high potency to inhibit the production of oxidized LDL induced by copper and, specifically, to reduce serum triglycerides in high‐fructose diet (HFD) fed rats and serum cholesterol in high‐cholesterol diet (HCD) fed animals. The levels of LDL and the ratio of LDL‐cholesterol (LDL‐C) to HDL‐cholesterol (HDL‐C) were reduced by HSE in both hyperlipidaemia models. Based on these findings, we suggest that HSE may be used to inhibit LDL oxidation and to prevent various types of hyperlipidaemia in HFD‐ or HCD‐fed rats. Copyright © 2004 Society of Chemical Industry
Synthesis and complete NMR spectral assignment of thiophene‐substituted sulfinyl monomers
Authors: Henckens Anja , Adriaensens Peter , Gelan Jan , Lutsen Laurence , Vanderzande Dirk 
Published: September 2004

AbstractThis paper describes the synthesis of thiophene‐substituted sulfinyl monomers. It comprises a four‐step reaction by which the thiophene unit is built in via Suzuki coupling. These monomers could be used as building blocks for the preparation of conducting polymers via a new concept: the sulfinyl precursor route i.e. via thiophene substituted poly(p‐phenylenevinylene) precursors. Furthermore, the complete 1H and 13C NMR signal assignment is presented. In addition to being essential for the characterization of the polymers concerned, it offers useful input information for further improvement of chemical shift prediction software. Furthermore, the T1C relaxation decay times are demonstrated to have the potential of being a fast and robust criterion for the spectral assignment of analogous monomers. Copyright © 2004 John Wiley & Sons, Ltd.
33S NMR spectra of sulfonium salts: calculated and experimental
Authors: Dickinson L. Charles , Chesnut Donald B. , Quin Louis D. 
Published: September 2004

Abstract33S NMR chemical shifts were calculated by the scaled DFT and EMPI approaches for the fluoride, chloride and bromide of trimethylsulfonium ion (1) and S‐methyltetrahydrothiophenium ion (2), in addition to the free cations. Experimental values were obtained for the iodides of 1 (δ +48, CS2 = 0 ppm) and 2 (δ +95), and were found to agree with the calculated values well within the standard deviation of 35 ppm (3.5% of the shielding range) established in earlier work for a great variety of sulfur compounds. An earlier literature value of δ +750 for the iodide of 2 is therefore to be replaced. Calculations provide a shift of δ +68 for S‐methylthianium ion with equatorial methyl, indicating that the reported value of δ +670 for the iodide is also incorrect. Copyright © 2004 John Wiley & Sons, Ltd.
A continuum‐discrete hydromechanical analysis of granular deposit liquefaction
Authors: Zeghal M. , El Shamy U. 
Published: September 2004

AbstractA coupled continuum‐discrete hydromechanical model was employed to analyse the liquefaction of a saturated loose deposit of cohesionless particles when subjected to a dynamic base excitation. The pore fluid flow was idealized using averaged Navier–Stokes equations and the discrete element method was employed to model the solid phase particles. A well established semi‐empirical relationship was utilized to quantify the fluid–particle interactions. The conducted simulations revealed a number of salient micro‐mechanical mechanisms and response patterns associated with the deposit liquefaction. Space and time variation of porosity was a major factor which affected the coupled response of the solid and fluid phases. Pore fluid flow was within Darcy's regime. The predicted response exhibited macroscopic patterns consistent with experimental results and case histories of the liquefaction of granular soil deposits. Copyright © 2004 John Wiley & Sons, Ltd.
K0 estimation in level granular soil from anisotropic wave velocities on the basis of micromechanics
Authors: Pan Y.‐W. , Liou J.‐C. 
Published: September 2004

AbstractThis study aims to explore the possibility for estimating K0 in a level ground of granular soil by seismic methods on the basis of micromechanics theory. The idea was to simulate in situ cross‐hole seismic method for the measurement of wave velocities along various directions of wave‐propagation. This work made use of a field simulator to control a K0 condition (zero lateral strain condition) in specimens. A series of vertical loading containing subsequent loading and unloading were applied to the specimen prepared by pluviation. In general, the K0 values determined experimentally in this work agreed with the exiting empirical relations. K0 value was also calibrated from measured anisotropic wave velocities using an optimization procedure. From the comparison of the back‐calculated and measured results of K0, it revealed the feasibility for the determination of the in situ lateral stress in granular soil by seismic methods and on the basis of micromechanics theory as long as enough wave‐velocity measurements along various directions of wave‐propagation were available. The potential for the usage of the presented methodology for the determination of the in situ lateral stress in level‐ground of granular soil by seismic methods seems encouraging. Copyright © 2004 John Wiley & Sons, Ltd.
Methanolysis of 1‐aryl‐1,2‐epoxycyclohexanes in the condensed and in the gas phase: importance of the substituent for the reaction mechanism
Authors: Crotti Paolo , Di Bussolo Valeria , Macchia Franco , Favero Lucilla , Pineschi Mauro , Lucarelli Laura , Roselli Graziella , Renzi Gabriele 
Published: September 2004

AbstractThe stereoselectivity of a series of 1‐aryl‐1,2‐epoxycyclohexanes substituted on the phenyl group was determined in acid methanolysis in the condensed phase (0.2 N H2SO4–MeOH) and in the reaction with MeOH in the gas phase under catalysis by a gaseous Brønsted acid (D3+). The results obtained show the presence of a clear Hammett‐type dependence of the syn/anti adduct ratio on the Brown σ+ of the substituent on the phenyl group, thus confirming the validity of the ion–dipole pair mechanism in order to rationalize the stereochemical behavior of 2‐aryloxiranes in opening reactions under acidic conditions. Only in the cases of the p‐OMe‐ and p‐NO2‐substituted epoxides, does an SN1 and an SN2 process, respectively, appear to be involved. Copyright © 2004 John Wiley & Sons, Ltd.
Rheological and mechanical properties of epoxy/polyurethane blends initiated by N‐benzylpyrazinium hexafluoroantimonate salt
Authors: Park Soo‐Jin , Kang Jun‐Gil , Kwon Soo‐Han 
Published: September 2004

AbstractIn this work the cure behavior and rheological and mechanical interfacial properties of the diglycidylether of bisphenol A (DGEBA)/polyurethane (PU) blend system, initiated by 1 wt % N‐benzylpyrazinium hexafluoroantimonate as a latent thermal catalyst, were investigated. To characterize the mechanical interfacial properties of the system, the critical stress intensity factor (KIC) was calculated with a single‐edge‐notched beam (SEN) beam fracture toughness test. And an impact test was performed at room and cryogenic temperatures to determine the performance of PU at room and low‐temperatures, respectively. As a result, the Ec of the blend system was increased with increasing PU content, showing a maximum value at 30 wt % PU, which was in good agreement with the mechanical properties of the blend system. Consequently, these results could be explained by the improvement that occurred in intermolecular hydrogen bonding between the hydroxyl group in EP and the isocyanate group in PU, resulting in increased compatibility of the components within the interpenetrating polymer networks. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3841–3848, 2004
Principles of carbopeptoid folding: a molecular dynamics simulation study
Authors: Baron Riccardo , Bakowies Dirk , van Gunsteren Wilfred F. 
Published: September 2004

AbstractThe conformational spaces of five oligomers of tetrahydrofuran‐based carbopeptoids in chloroform and dimethyl sulfoxide were investigated through nine molecular dynamics simulations. Prompted by nuclear magnetic resonance experiments that indicated various stable folds for some but not all of these carbopeptoids, their folding behaviour was investigated as a function of stereochemistry, chain length and solvent. The conformational distributions of these molecules were analysed in terms of occurrence of hydrogen bonds, backbone torsional‐angle distributions, conformational clustering and solute configurational entropy. While a cis‐linkage across the tetrahydrofuran ring favours right‐handed helical structures, a trans‐linkage results in a larger conformational variability. Intra‐solute hydrogen bonding is reduced with increasing chain length and with increasing solvent polarity. Solute configurational entropies confirm the picture obtained: they are smaller for cis‐ than for trans‐linked peptides, for chloroform than for dimethyl sulfoxide as solvent and for shorter peptide chains. The simulations provide an atomic picture of molecular conformational variability that is consistent with the available experimental data. Copyright © 2004 European Peptide Society and John Wiley & Sons, Ltd.
Structure‐activity relationship study of anoplin
Authors: Ifrah Dan , Doisy Xavier , Ryge Trine S. , Hansen Paul R. 
Published: September 2004

AbstractAnoplin is a decapeptide amide, GLLKRIKTLL‐NH2 derived from the venom sac of the solitary spider wasp, Anoplius samariensis. It is active against Gram‐positive and Gram‐negative bacteria and is not hemolytic towards human erythrocytes. The present paper reports a structure‐activity study of anoplin based on 37 analogues including an Ala‐scan, C‐ and N‐truncations, and single and multiple residue substitutions with various amino acids. The analogues were tested for antibacterial activity against both S. aureus ATCC 25923 and E. coli ATCC 25922, and several potent antibacterial analogues were identified. The cytotoxicity of the analogues against human erythrocytes was assessed in a hemolytic activity assay. The antibacterial activity and selectivity of the analogues against S. aureus and E. coli varied considerably, depending on the hydrophobicity and position of the various substituted amino acids. In certain cases the selectivity for Gram‐positive and Gram‐negative bacteria was either reversed or altogether eliminated. In addition, it was generally found that antibacterial activity coincided with hemolytic activity. Copyright © 2004 European Peptide Society and John Wiley & Sons, Ltd.
Nonadiabatic sudden increase of the cooperative kinetic effect at lattice energy stabilization—Microscopic mechanism of superconducting state transition: Model study of MgB2
Authors: Baňacký Pavol 
Published: September 2004

AbstractThe theory of the nonadiabatic electron–vibration interactions has been applied to the study of MgB2 superconducting state transition. It has been shown that at nonadiabatic conditions in which the Born–Oppenheimer approximation is not valid and electronic motion is dependent not only on the nuclear coordinates but also on the nuclear momenta, the fermionic ground‐state energy of the studied system can be stabilized by nonadiabatic electron–phonon interactions at broken translation symmetry. Moreover, the new arising state is geometrically degenerate; i.e., there are an infinite number of different nuclear configurations with the same fermionic ground‐state energy. The model study of MgB2 yields results that are in a good agreement with the experimental data. For distorted lattice, with 0.016 Å/atom of in‐plane out‐of‐phase BB atoms displacements out of the equilibrium (E2g phonon mode) when the nonadiabatic interactions are most effective, it has been calculated that the new arising state is 87 meV/unit cell more stable than the equilibrium–high symmetry clumped nuclear structure at the level of the Born–Oppenheimer approximation. The calculated Tc is 39.5 K. The resulting density of states exhibits two‐peak character, in full agreement with the tunneling spectra. The peaks are at ±4 meV, corresponding to the change of the π band density of states, and at ±7.6 meV, corresponding to the σ band. The superconducting state transition can be characterized as a nonadiabatic sudden increase of the cooperative kinetic effect at lattice energy stabilization (NASICKELES). © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Nonadiabatic photodissociation dynamics
Authors: Zhao Mei‐Yu , Meng Qing‐Tian , Xie Ting‐Xian , Han Ke‐Li , He Guo‐Zhong 
Published: September 2004

AbstractThe photodissociation dynamics of the triatomic (or pseudo‐triatomic) system in the nonadiabatic multiple electronic states is investigated by employing a time‐dependent quantum wave packet method, while the time propagation of the wave packet is carried out using the split‐operator scheme. As a numerical example, the photodissociation dynamics of CH3I in three electronic states 1Q1(A′), 1Q1(A″), and 3Q0+ is studied and CH3I is treated as a pseudotriatomic model. The absorption spectra and product vibrational state distributions are calculated and compared with previous theoretical work. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Correlation between sensitivity and approximated heats of detonation of several nitroamines using quantum mechanical methods
Authors: Edwards Jesse , Eybl Claudia , Johnson Brian 
Published: September 2004

AbstractStorage, synthesis, and application of energetic materials is significantly impacted by the fundamental property of sensitivity. The method of storage and handling is affected by the sensitive nature of the explosive. Possessing the ability to predict the sensitivity of energetic material candidates before expensive synthesis is begun would be an asset. Also, predicting the applications of various energetic compounds before synthesis and testing can be made possible with the aid of sensitivity predictions. Quantum mechanical methods are applied to approximating the heat of detonation. Correlation between heat of detonation and impact sensitivity is examined. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004