bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of mixed solvent consisting of water and organic solvent on photografting of glycidyl methacrylate on polyethylene film
Authors: Irwan Ginting Suka , Kuroda Shin‐ichi , Kubota Hitoshi , Kondo Takashi 
Published: April 2004

AbstractThe effect of a mixed solvent consisting of water and organic solvents such as acetone and methanol on the photografting (λ > 300 nm) of glycidyl methacrylate (GMA) on linear low‐density polyethylene film (thickness = 30 μm) was investigated at 60°C. Xanthone was used as a photoinitiator by coating the film surfaces with it. The maximum percentage of grafting was observed at a certain concentration of organic solvent in the mixed solvent, which depends on the nature of organic solvents such as methanol (ca. 5 vol %) and acetone (ca. 15 vol %). On the basis of attenuated total reflection infrared spectroscopy of the grafted film, the absorbance ratio of the carbonyl peak of grafted poly(GMA) chains at 1728 cm−1 to the methylene peak of polyethylene substrate at 1460 cm−1 increased with increasing the concentration (0–15 vol %) of organic solvent, which was commonly observed for methanol and acetone. Distribution of grafted poly(GMA) chains in the cross section of the grafted film was examined using a scanning electron microscope. The results showed that the grafted chains of the GMA‐grafted samples prepared in water solvent tended to penetrate into the inside of the film compared to those of the grafted samples prepared in the mixed solvent due to higher affinity of the GMA monomer to the polyethylene substrate compared to the organic solvents used. Grafted poly(GMA) chains were aminated with ethylenediamine (En) in N,N′‐dimethylformamide at 70°C for 3 h. It was found that the reactivity toward En was higher for the sample prepared in mixed solvent than for the sample prepared in water solvent. The aminated GMA‐grafted sample had the ability to adsorb cupric ions, showing that a higher amount of adsorbed cupric ion is recorded for the sample prepared in mixed solvent than for the sample prepared in water solvent. Complexes of aminated GMA‐grafted chains with cupric ion exhibited the catalytic activity of decomposition of hydrogen peroxide at 50°C, and its ability depended on the location of the grafted chains in the film substrate. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 994–1000, 2004
The private costs and benefits of environmental self‐regulation: which firms have most to gain?
Authors: Stoeckl Natalie 
Published: April 2004

AbstractA (correctly designed) voluntary self‐regulatory scheme can – in theory – improve social welfare if the benefits to society outweigh the costs. However, businesses may not choose to participate in a voluntary scheme if their private benefits do not outweigh their costs; external benefits are irrelevant to the profit maximizing firm. This paper reviews literature on self‐regulation, primarily focusing on factors that influence the net private benefits of environmental programmes. The literature is summarized in a manner that allows one to identify characteristics of firms that are most likely to accrue positive net benefit from environmental programmes, and to determine ways in which self‐regulatory bodies might raise those benefits, thereby increasing participation rates. Copyright © 2004 John Wiley & Sons, Ltd and ERP Environment.
A Comparison of the Reactivity of Ni Atoms Toward CH4, SiH4, and SnH4: A Combined Matrix Isolation and Quantum‐Chemical Study
Authors: Himmel Hans‐Jörg 
Published: April 2004

AbstractNickel atoms are shown to react spontaneously with SiH4 and SnH4 to give the insertion products HNiSiH3 and HNiSnH3. With CH4, however, no spontaneous reaction occurs, in agreement with earlier reports; HNiCH3 can be formed only on photolytic activation of the Ni atom. The reaction products were characterized experimentally by IR spectroscopy, including the effect of isotopic substitution (H/D), and by quantum‐chemical calculations. They all have Cs symmetry with a terminal NiH bond and three terminal EH bonds (E=Si, Sn). Strikingly, the H‐Ni‐E bond angles are less than 90°, and there is a weak interaction between the H atom bound to Ni and the E atom. The structures are compared with those of other molecules of general formula MSiH4 that have been characterized recently in our group (M=Ti, Ni, Ga). While TiSiH4 has three Ti‐H‐Si bridges, both NiSiH4 and GaSiH4 exhibit only terminal NiH and EH bonds, but with the difference that there is no interaction between the H atom bound to Ga and the Si atom.
Estimating accuracy of electrostatic finite element models
Authors: Shaul Diana N. A. , Sumner Timothy J. 
Published: April 2004

AbstractWe present a method to estimate the accuracy of force, torque and stiffness predictions of electrostatic finite element models. We show that generally, the distance between the true and converged capacitance obtained by uniformly increasing element polynomial levels is a fraction of the convergence range and similar models have similar convergence characteristics. We propose exploiting these two properties to estimate accuracy by correcting capacitances based on a single convergence run and using least‐squares fitting to capture the error associated with convergence differences. Copyright © 2004 John Wiley & Sons, Ltd.
Numerical error patterns for a scheme with hermite interpolation for 1 + 1 linear wave equations
Authors: Zhu Zuojin , Wang Xiangqi , Su Zhenbi 
Published: April 2004

AbstractNumerical error patterns were presented when the fourth‐order scheme based on Hermite interpolation was used to solve the 1 + 1 linear wave equation. Since most non‐linear equations for real systems can be converted into linear forms by using proper transformations, this study certainly pertains its practical significance. The analytical solution was obtained under inhomogeneous initial and boundary conditions. It was found that not only the Hurst index of an error train at a given position but also its spatial distribution is dependent on the ratio of temporal to spatial intervals. The solution process with the fourth‐order scheme based on Hermite interpolation diverges as the ratio is greater than unity. The results show that regular error pattern and smaller maxima of absolute values of numerical errors can be obtained when the ratio is set as unity; while chaotic phenomena for the numerical error propagation process can appear when the ratio is less than unity. It was found that it is better to choose the ratio as unity for the numerical solution of 1 + 1 linear wave equation with the scheme; while other selections for the ratio in the scheme can bring about chaotic patterns for the numerical errors. Copyright © 2004 John Wiley & Sons, Ltd.
Exercise training restores abnormal myocardial glucose utilization and cardiac function in diabetes
Authors: Broderick Tom L. , Poirier Paul , Gillis Melissa 
Published: April 2004

AbstractBackgroundClinical and experimental studies have shown that a reduction in myocardial glucose utilization is a factor contributing to diabetic cardiomyopathy. This study determined whether exercise training could prevent the depression in glucose utilization observed in the diabetic rat heart.MethodsDiabetes was induced in Sprague–Dawley rats by an intravenous injection of streptozotocin (60 mg/kg). After 10 weeks of treadmill running, exogenous myocardial glucose utilization and cardiac function were determined in isolated working hearts perfused under aerobic conditions and then subjected to a 60‐min period of low‐flow ischemia followed by reperfusion.ResultsCompared to aerobically perfused sedentary control hearts, rates of myocardial glucose oxidation and glycolysis were lower in diabetic hearts. Diabetes was also characterized by a pronounced decrease in cardiac function. Following exercise training, rates of myocardial glucose oxidation and glycolysis were restored and cardiac performance was improved compared to sedentary diabetic hearts. During low‐flow ischemia, the decrease in glycolysis observed in hearts of sedentary diabetic rats was attenuated following exercise training. Following ischemia, glucose oxidation and glycolysis returned to preischemic levels in all groups. However, hearts from trained diabetic animals had higher rates of glucose oxidation compared to their respective sedentary group. This was accompanied by an enhanced recovery of heart function following ischemia.ConclusionsOur results indicate that exercise training is effective in preventing the depression in myocardial glucose metabolism observed in the diabetic rat. This may explain the benefits of exercise in preventing cardiac dysfunction in diabetes. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis, Molecular Structure and Catalytic Activity of Six‐Coordinate Chloro(hydrido)‐ and Dihydridoruthenium(II) and ‐osmium(II) Complexes with the Chiral Ligands PiPr2NH(Me)Ph, (S,S)‐Chiraphos and (S,S,)‐Diop
Authors: Schlünken Christoph , Esteruelas Miguel A. , Lahoz Fernando J. , Oro Luis A. , Werner Helmut 
Published: April 2004

AbstractThe five‐coordinate compounds [MHCl(CO)(PiPr3)2] (where 1a: M = Ru; 1b: M = Os) react with PiPr2R* [where R* = CH(Me)Ph] to give the octahedral complexes mer‐[MHCl(CO)(PiPr2R*)3] (6 and 7). The lability of the phosphane trans to the hydride is illustrated by the replacement reactions with CO, P(OMe)3 and C2(CO2Me)2, which afford the substitution products [MHCl(CO)(L)(PiPr2R*)2] (8−12) in high yields. The reactions of 1a and 1b with (S,S)‐Chiraphos and (S,S)‐Diop lead to one or two diastereoisomers of the chelate complexes [MHCl(CO)(PiPr3)(Chiraphos)] (15, 16) and [MHCl(CO)(PiPr3)(Diop)] (17, 18); the ratio of the diastereoisomers is dependent on the metal, the bidentate ligand and the reaction conditions. The racemate of [OsHCl(CO)(PiPr3)(dppe)] (14) was obtained from 1b and 1,2‐C2H4(PPh2)2 (dppe). The hydrido(tetrahydroboranato) compounds [MH(κ2‐H2BH2)(CO)(PiPr3)2] (where 2a: M = Ru; 2b: M = Os) also react with (S,S)‐Chiraphos and (S,S)‐Diop to give either the mononuclear, octahedral, chelate complexes 19−21 or, for M = Os and (S,S)‐Diop, the dinuclear compound [{OsH2(CO)(PiPr3)2}2(μ‐Diop)] (22). The molecular structure of 22 was determined crystallographically. Treatment of [OsH2Cl2(PiPr3)2] (23) with two equivalents of (S,S)‐Chiraphos afforded stepwise [OsH2Cl2(PiPr3)(Chiraphos)] (25) and, after reductive elimination of HCl and displacement of PiPr3, trans‐[OsHCl(Chiraphos)2] (24). Both 24 and [OsH2(Chiraphos)2] (27), which was prepared from 24 and NaBH4/MeOH, were transformed with HBF4 in diethyl ether into the dihydrogen complexes [OsCl(H2)(Chiraphos)2]BF4 (28) and [OsH(H2)(Chiraphos)2]BF4 (29) in excellent yields. The catalytic activity of the chloro(hydrido)‐ and dihydridometal derivatives in the asymmetric transfer hydrogenation of acetophenone with 2‐propanol was investigated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Intramolecular Nucleophilic Substitution in a C6F5 Moiety Assisted by Antimony
Authors: Shutov Pavel L. , Karlov Sergey S. , Harms Klaus , Tyurin Daniil A. , Sundermeyer Jörg , Lorberth Jörg , Zaitseva Galina S. 
Published: April 2004

AbstractAntimony tris‐amides — (Et2N)3−nSb[N(C6F5)(2‐C5H4N)]n [n = 1 (3), 2 (4) or 3 (5)] — have been prepared by treatment of Sb(NEt2)3 (1) with stoichiometric amounts of (2‐C5H4N)(C6F5)NH (2). In contrast to amide 5, compounds 3 and 4 are unexpectedly unstable and react further to give the bis‐amido antimony fluorides [(2‐Et2N‐C6F4)(2‐C5H4N)N]Sb(F)[N(C2H5)2] (6) and [(2‐Et2N‐C6F4)(2‐C5H4N)N]Sb(F)[N(C6F5)(2‐C5H4N)] (7). The structure of 7 was confirmed by X‐ray diffraction studies. DFT calculations, which reproduce the principal features of compound 7’s geometry, have been used to explain the possible reaction pathway of this ortho‐directed metathetical fluoride‐amide exchange. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Day treatment group programme for eating disorders: reasons for drop‐out
Authors: Franzen Ute , Backmund Herbert , Gerlinghoff Monika 
Published: April 2004

AbstractThis study was designed to identify clinical variables and personality factors that could predict the completion or non‐completion of a day treatment group programme for patients with eating disorders. Patients (n = 125) were subdivided into those who had completed a 4‐month day treatment programme (n = 106) and those who had dropped out (n = 19). All the patients had been assessed with regard to eating psychopathology, general psychopathology and personality features at the beginning of the programme. At presentation, 50.4 per cent fulfilled DSM‐IV criteria for anorexia nervosa, 39.2 per cent for bulimia nervosa and 10.4 per cent for an eating disorder not otherwise specified. Non‐completion of therapy was associated with more severe bulimic symptoms, high levels of aggression and extraversion and low levels of inhibitedness. Assessment of these characteristics could be used to improve the therapy programme and to help those patients at increased risk of dropping out. Copyright © 2004 John Wiley & Sons, Ltd and Eating Disorders Association.
Permutation tests for factorially designed neuroimaging experiments
Authors: Suckling John , Bullmore Ed 
Published: April 2004

AbstractPermutation methods for analysis of functional neuroimaging data acquired as factorially designed experiments are described and validated. The F ratio was estimated for main effects and interactions at each voxel in standard space. Critical values corresponding to probability thresholds were derived from a null distribution sampled by appropriate permutation of observations. Spatially informed, cluster‐level test statistics were generated by applying a preliminary probability threshold to the voxel F maps and then computing the sum of voxel statistics in each of the resulting three‐dimensional clusters, i.e., cluster “mass.” Using simulations comprising two between‐ or within‐subject factors each with two or three levels, contaminated by Gaussian and non‐normal noise, the voxel‐wise permutation test was compared to the standard parametric F test and to the performance of the spatially informed statistic using receiver operating characteristic (ROC) curves. Validity of the permutation‐testing algorithm and software is endorsed by almost identical performance of parametric and permutation tests of the voxel‐level F statistic. Permutation testing of suprathreshold voxel cluster mass, however, was found to provide consistently superior sensitivity to detect simulated signals than either of the voxel‐level tests. The methods are also illustrated by application to an experimental dataset designed to investigate effects of antidepressant drug treatment on brain activation by implicit sad facial affect perception in patients with major depression. Antidepressant drug effects in left amygdala and ventral striatum were detected by this software for an interaction between time (within‐subject factor) and group (between‐subject factor) in a representative two‐way factorial design. Hum. Brain Mapping 22:193–205, 2004. © 2004 Wiley‐Liss, Inc.
Design, Synthesis, and Characterization of Photolabeling Probes for the Study of the Mechanisms of the Antiviral Effects of Ribavirin
Authors: Wu Qiongyou , Qu Fanqi , Wan Jinqiao , Zhu Xun , Xia Yi , Peng Ling 
Published: April 2004

AbstractRibavirin, the only small molecule available so far for treating hepatitis‐C‐virus infection, was recently used in an emergency context to treat patients with severe acute respiratory syndrome (SARS) in the early stages of the disease. To study the mechanisms responsible for the antiviral effects of ribavirin by using a photolabeling approach, we designed, synthesized, and characterized the azidotriazole nucleosides 1 and 2 as photolabeling probes of ribavirin. These probes were synthesized either by performing nucleophilic substitution of the corresponding bromotriazole nucleoside with NaN3 (Scheme 2) or by directly coupling the azidotriazole with the protected ribose sugar (Scheme 4). The azidotriazole nucleosides 1 and 2 showed a fast, clear‐cut photochemical reaction, which suggests that they are promising candidates for use in photolabeling studies.
Spectroscopic Properties of 4‐Pyridoxic Acid as a Function of pH and Solvent
Authors: Bueno Claudia , Guerrero Juan , Encinas María Victoria 
Published: April 2004

AbstractThe photophysical properties and acid/base equilibria of 4‐pyridoxic acid (=3‐hydroxy‐5‐(hydroxymethyl)‐2‐methylpyridine‐4‐carboxylic acid), the final product of the catabolism of vitamin B6, have been studied in aqueous solutions. The ground state of 4‐pyridoxic acid exhibits the different protonated forms A–D in the range of H0=−6 to pH 11.5. HMQC‐ and HMBC‐NMR Studies allowed the pH‐dependent assignment of the different C‐atoms, and the evaluation of the deprotonation sequence. The 3‐OH group in the ground state has a ‘pKa’ of H0=−0.64, which is much lower than that found for other vitamin B6 related compounds. The pKa value of the 4‐COOH group is 5.4. Fluorescence studies showed that the same species exist at the lowest excited singlet state, but in different pH ranges. The 3‐OH group is four pH units more acidic in the lowest excited singlet state than in the ground state. Excitation spectra and emission decays in the pH range of 8 to 11.5 indicate that the pyridine N‐atom is more basic in the excited singlet state than in the ground state. The emission spectra are red‐shifted in protic solvents, in agreement with an intramolecular H‐bond between the ionized 3‐OH group and the nonionized 4‐COOH group.
Novel Diterpenoids from Salvia dugesii
Authors: Xu Gang , Peng Liyan , Niu Xuemei , Zhao Qinshi , Li Rongtao , Sun Handong 
Published: April 2004

AbstractTwo novel rearranged clerodane diterpenoids, dugesin A (1) and dugesin B (2), were isolated from the aerial parts of Salvia dugesii, together with five known clerodane diterpenoids: isosalvipuberulin (3), salvipuberulin (4), tilifodiolide (5), salvifolin (6), and salvifaricin (7). Their structures were elucidated on the basis of different spectroscopic techniques. The isolation and identification of these compounds are significant from both biosynthetisis and chemotaxonomy points of view.
Synthesis and Cytotoxic and Antiplatelet Activities of Dibenzofuran‐ and Carbazole‐Substituted Oximes
Authors: Wang Tai‐Chi , Chen I‐Li , Kuo Daih‐Huang , Liao Chang‐Hui 
Published: April 2004

AbstractThe dibenzofuran‐ and carbazole‐substituted oximes or methyloximes 5–10 were prepared and evaluated for their cytotoxic and antiplatelet activities. These compounds were synthesized via alkylation of dibenzofuran‐2‐ol or 9H‐carbazol‐2‐ol with α‐halocarbonyl reagents, followed by reaction with NH2OH or NH2OMe (Scheme). A preliminary anticancer assay indicated that the oxime‐type dibenzofuran derivatives 5 and 7a–d are active, while the corresponding oxime ethers 9b and 9c are inactive at the same concentration. Therefore, a H‐bond‐donating group seems to be crucial for cytotoxicity. Among the compounds tested, 2‐[(dibenzo[b,d]furan‐2‐yl)oxy]‐1‐(4‐methoxyphenyl)ethan‐1‐one O‐methyloxime (9c) exhibited potent inhibitory activity against platelet aggregation induced by arachidonic acid, with an IC50 value of 14.87 μM, without being cytotoxic at a concentration of 100 μM.
Binding affinity prediction with different force fields: Examination of the linear interaction energy method
Authors: Almlöf Martin , Brandsdal BjØrn O. , Åqvist Johan 
Published: April 2004

AbstractA systematic study of the linear interaction energy (LIE) method and the possible dependence of its parameterization on the force field and system (receptor binding site) is reported. We have calculated the binding free energy for nine different ligands in complex with P450cam using three different force fields (Amber95, Gromos87, and OPLS‐AA). The results from these LIE calculations using our earlier parameterization give relative free energies of binding that agree remarkably well with the experimental data. However, the absolute energies are too positive for all three force fields, and it is clear that an additional constant term (γ) is required in this case. Out of five examined LIE models, the same one emerges as the best for all three force fields, and this, in fact, corresponds to our earlier one apart from the addition of the constant γ, which is almost identical for the three force fields. Thus, the present free energy calculations clearly indicate that the coefficients of the LIE method are independent of the force field used. Their relation to solvation free energies is also demonstrated. The only free parameter of the best model is γ, which is found to depend on the hydrophobicity of the binding site. We also attempt to quantify the binding site hydrophobicity of four different proteins which shows that the ordering of γ's for these sites reflects the fraction of hydrophobic surface area. © 2004 Wiley Periodicals, Inc. J Comput Chem 10: 1242–1254, 2004
Regional hydrodynamic gene delivery to the rat liver with physiological volumes of DNA solution
Authors: Zhang Xiaohong , Dong Xuebin , Sawyer Greta J. , Collins Louise , Fabre John W. 
Published: April 2004

AbstractBackgroundThe major barrier to the clinical application of hydrodynamic gene delivery to the liver is the large volume of fluid required using standard protocols. Regional hydrodynamic gene delivery via branches of the portal vein has not previously been reported, and we have evaluated this approach in a rat model.MethodsThe pGL3 plasmid with the luciferase reporter gene was used at 50 µg/ml in isotonic solutions, and was administered with a syringe pump for precise control of the hydrodynamic conditions evaluated. Gene expression was individually measured in six anatomically distinct liver lobes. The effect of systemic chloroquine to promote endocytic escape and a (Lys)16‐containing peptide to condense the DNA into ∼100‐nm nanoparticles was also evaluated.ResultsHydrodynamic conditions for excellent gene delivery were obtained by using 3‐ml volumes (∼12 ml/kg) of isotonic DNA solution delivered at 24 ml/min to the right lateral lobe (∼20% of the liver mass). Under these conditions, >95% of gene delivery usually occurred in the targeted right lateral lobe. Outflow obstruction was essential for gene delivery, both at optimal and at very low levels of hydrodynamic gene delivery. The use of systemic chloroquine to promote endocytic escape did not augment hydrodynamic gene delivery, while condensation of DNA in non‐ionic isotonic solutions (5% dextrose) to nanoparticles of ∼100 nm completely abolished gene delivery.ConclusionsRegional hydrodynamic gene delivery via a branch of the portal vein offers a physiological model of liver gene therapy, for experimental and clinical application. Copyright © 2004 John Wiley & Sons, Ltd.
On the interval number of special graphs
Authors: Balogh József , Ochem Pascal , Pluhár András 
Published: April 2004

AbstractThe interval number of a graph G is the least natural number t such that G is the intersection graph of sets, each of which is the union of at most t intervals, denoted by i(G). Griggs and West showed that $i(G)\le \lceil {1\over 2} (d+1)\rceil $. We describe the extremal graphs for that inequality when d is even. For three special perfect graph classes we give bounds on the interval number in terms of the independence number. Finally, we show that a graph needs to contain large complete bipartite induced subgraphs in order to have interval number larger than the random graph on the same number of vertices. © 2004 Wiley Periodicals, Inc. J Graph Theory 46: 241–253, 2004