bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Polymeric Materials with Interferential Optical Properties
Authors: Ghannam Leïla , Garay Hélène , François Jeanne , Billon Laurent 
Published: June 2007

AbstractNature provides a wide pallet of colors but also a wide number of fascinating optical phenomena such as nacre or interferential effects, which can be observed in insect wings and shellfish. The origin of such effects is attributed to the presence of highly ordered arrangements in Nature's materials. The aim of this paper is to focus some new approaches and advances for creating interferential optical phenomena as observed in nature by tuning or modeling the polymer architectures or organization.A relatively simple method is described to prepare organic/inorganic hybrid pigments constituted of mica platelets and adsorbed polymer layers. It is shown that the color of mica is changed upon polymer adsorption, and when one of the copolymer sequences includes a dye, its color is influenced by the chemical properties of the mica surface. Moreover, a new facile route is presented to obtain highly ordered surfaces using ionomer macromolecular designs synthesized in one step by controlled radical polymerization. The preparation of films with very regular pore size and spatial organization is successfully realized by using ionomer solutions. An original property of these films with an iridescent color obtained by light diffraction as a result of the optical interferences of sunlight with the periodic honeycomb structures is presented.All these new materials based on polymeric controlled structures can reproduce nature by creating an optical interferential and iridescent material, which offers new fascinating applications as original bio‐mimetic materials on inorganic surfaces.magnified image
Price rigidity and flexibility: recent theoretical developments
Authors: Levy Daniel 
Published: June 2007

AbstractThe price system, the adjustment of prices to changes in market conditions, is the primary mechanism by which markets function and by which the three most basic questions get answered: what to produce, how much to produce and for whom to produce. To the behaviour of price and price system, therefore, have fundamental implications for many key issues in microeconomics and industrial organization, as well as in macroeconomics and monetary economics. In microeconomics, managerial economics, and industrial organization, economists focus on the price system efficiency. In macroeconomics and monetary economics, economists focus on the extent to which nominal prices fail to adjust to changes in market conditions. Nominal price rigidities play a particularly important role in modern monetary economics and in the conduct of monetary policy because of their ability to explain short‐run monetary non‐neutrality. The behaviour of prices, and in particular the extent of their rigidity and flexibility, therefore, is of central importance in economics. This introductory essay briefly summarizes the eight studies of price rigidity that are included in this special issue. Copyright © 2007 John Wiley & Sons, Ltd.
Classical and nonclassical symmetries for a Kuramoto–Sivashinsky equation with dispersive effects
Authors: Bruzón M. S. , Gandarias M. L. , Camacho J. C. 
Published: June 2007

AbstractWe apply the Lie‐group formalism and the nonclassical method due to Bluman and Cole to deduce symmetries of the generalized Kuramoto–Sivashinsky equation with dispersive effects. We make a full analysis of the symmetry reductions and we prove that the nonclassical method applied to the equation leads to new reductions, which cannot be obtained by Lie classical symmetries. Some new solutions can be derived. Copyright © 2007 John Wiley & Sons, Ltd.
Antigenotoxic effects of the phytoestrogen pelargonidin chloride and the polyphenol chlorogenic acid
Authors: Abraham Suresh K. , Schupp Nicole , Schmid Ursula , Stopper Helga 
Published: June 2007

AbstractPelargonidin (PEL), a common anthocyanidin with estrogenic activity, was tested in HL‐60 cells for its genotoxicity and possible antigenotoxic effects against 4‐nitroquinoline 1‐oxide (NQO), a potent mutagen and carcinogen which induces oxidative stress. To take into account potential interactions between phytochemicals within normal human nutrition, we evaluated a combination of PEL with the nonestrogenic phytochemical chlorogenic acid (CLA), one of the most abundant polyphenols in the human diet. PEL (⪇2 μM) and CLA (⪇800 μM) were nongenotoxic in the micronucleus test. We observed significant antigenotoxic effects against NQO with both compounds, but no additive interaction of PEL and CLA. Comet assay results showed a nonsignificant reduction in NQO‐induced DNA damage with both compounds and their combination. Flow cytometric analysis of oxidative stress revealed significant protection against NQO‐induced oxidative stress by PEL, CLA, and their combination. Furthermore, PEL and CLA prevented the NQO‐induced reduction in GSH level. This could be a mechanism for the observed reduction in genotoxicity. In conclusion, the phytoestrogen PEL revealed antioxidative and antigenotoxic properties in HL‐60 cells, but no significant additive interaction with the abundant nutritional polyphenol CLA under the tested conditions.
In vitro and in vivo metabolism of the soy isoflavone glycitein
Authors: Rüfer Corinna E. , Maul Ronald , Donauer Eva , Fabian Eric J. , Kulling Sabine E. 
Published: June 2007

AbstractGlycitein (GLY) is a major isoflavone of soy germ which is used as a functional ingredient to enrich foods with isoflavones as well as a component of soy supplements. Since data on the metabolism of GLY are incomplete, the in vitro phase I metabolism of GLY using rat liver microsomes, human liver microsomes (HLM), as well as human fecal flora was investigated. Furthermore, the in vivo metabolism has been studied after administration of GLY to Sprague–Dawley rats. The identification of the formed metabolites has been elucidated using HPLC/DAD, HPLC/API‐ES MS, GC/MS, as well as reference compounds. With respect to the phase I metabolism, GLY has been converted to ten metabolites by liver microsomes of Aroclor‐induced Wistar rats with 8‐hydroxy(OH)‐GLY as the main metabolite. HLM converted GLY to six metabolites with 8‐OH‐GLY and 6‐OH‐daidzein (DAI) being the major products. No sex‐related differences were observed in each system. Intestinal metabolism of GLY led to four metabolites with 6‐OH‐DAI as the main product. The in vivo metabolism in rat urine after single‐dose administration of GLY resulted in the identification of three oxidative and two bacterial metabolites as well as the demethylation product 6‐OH‐DAI as the main metabolite.
Helical and random coil conformations of N‐propargylamide polymer and copolymers
Authors: Deng Jianping , Chen Bo , Zhang Zhigang , Yang Wantai 
Published: June 2007

AbstractAn N‐propargylamide monomer, CHCCH2NHCOC(CH3)2CH2CH3 (monomer 9), was polymerized in the presence of (nbd)Rh+B−(C6H5)4 (nbd represents norbornadiene) in CH2Cl2, CHCl3, tetrahydrofuran or dimethylformamide, to provide polymers with moderate number‐average molecular weights (Mn = 8700–12 100 g mol−1) in high yields (≥92%). The resulting poly(N‐propargylamide) (polymer 9) dissolves almost completely in CHCl3 (>95%). According to the UV‐visible spectra, measured at various temperatures, polymer 9 forms relatively stable helices over a wide temperature range (35–65 °C). Moreover, it exhibits reversible conformational transitions from an ordered helix to a random coil. On copolymerization of monomer 9 with CHCCH2NHCO(CH2)3CH3 (monomer 4) or CHCCH2NHCO(CH2)7CH3 (monomer 8), the solubility of polymer 9 improves noticeably. All the copolymers form helices under the experimental conditions. From the viewpoint of monomers 4 and 8, copolymerization with monomer 9 is favorable in terms of the copolymers forming helices. These findings reveal that the helical content and thermodynamic stability of the helices formed in the copolymers are likely to be controlled by selecting a suitable comonomer and by adjusting the composition of the copolymer. Copyright © 2007 Society of Chemical Industry
Pharmacological doses of dietary curcumin increase colon epithelial cell proliferation in vivo in rats
Authors: Kim Sylvia Jeewon , Hellerstein Marc K. 
Published: June 2007

AbstractAlthough curcumin has preventive actions in animal models of colon cancer, whether the mechanism of action is through anti‐proliferation in normal environment is not clearly understood. Here, we studied the effects of chemopreventive doses of curcumin on the proliferation rate of colon epithelial cells (CEC), using a recently developed stable isotope – mass spectrometric method for measuring DNA synthesis rate. Adult male F344 rats were given diets containing 0, 2 and 4% curcumin for 5 weeks. 4% 2H2O was given in drinking water to label DNA, after a priming bolus, for 4 days prior to sacrifice. The isotopic enrichment of the deoxyribose moiety of deoxyadenosine from DNA was measured by gas chromatography – mass spectrometry. Cell cycle analysis was performed after propidium iodide staining of CECs. Curcumin administration did not reduce but instead resulted in dose‐dependent increases in CEC proliferation rate (p < 0.05) for 2% and 4% curcumin vs 0%). The length of the colon crypts and the fraction of cells in S‐phase were also increased in the 2% and 4% curcumin groups (p < 0.05). Thus, pharmacological doses of curcumin increase CEC proliferation rate and pool size in normal rats. Reduction of CEC proliferation therefore cannot explain the proposed chemopreventive actions of curcumin in colon cancer. Copyright © 2007 John Wiley & Sons, Ltd.
Thymoquinone decreases AGE‐induced NF‐κB activation in proximal tubular epithelial cells
Authors: Sayed Ahmed Amir Radwan , Morcos Michael 
Published: June 2007

AbstractThe inhibitory effects of thymoquinone (TQ) on activation of the redox‐sensitive transcription factor nuclear factor kappa B (NF‐κB) and interleukin‐6 (IL‐6) were studied in vitro. Human proximal tubular epithelial cells (pTECs) were cultivated and stimulated with advanced glycation end products (AGEs) and the effects of TQ were studied. A significant reduction of AGE‐induced NF‐κB‐activation and Il‐6 expression was observed. This points to potential antioxidative qualities of TQ. Copyright © 2007 John Wiley & Sons, Ltd.
Prophylaxis effect of Trigonella foenum graecum L. seeds on renal stone formation in rats
Authors: Laroubi Amine , Touhami Mohammed , Farouk Loubna , Zrara Ibtissam , Aboufatima Rachida , Benharref Ahmmed , Chait Abderrahman 
Published: June 2007

AbstractDespite considerable progress in medical therapy, there is no satisfactory drug to treat kidney stones. Therefore, the current study aimed to look for an alternative by using Trigonella foenum graecum (Tfg) on nephrolithiasic rats as a preventive agent against the development of kidney stones, which is commonly used in Morocco as a phytotherapeutic agent. The inhibitory effect of the aqueous extract of Tfg seeds was examined on the formation of calcium oxalate renal stones induced by ethylene glycol (EG) with ammonium chloride. At the end of the experiment all kidneys were removed and examined microscopically for possible crystal/stone locations and the total calcium amount in the renal tissue was evaluated. The blood was recovered to determine the levels of calcium, phosphorus, creatinine and urea. The results showed that the amount of calcification in the kidneys and the total calcium amount of the renal tissue in rats treated with Tfg were significantly reduced compared with the untreated group. Consequently, Tfg may be a useful agent in the treatment of patients with calcic urolithiasis. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of oriental herbal prescription Guan‐Xin‐Er‐Hao on coronary flow in healthy volunteers and antiapoptosis on myocardial ischemia‐reperfusion in rat models
Authors: Zhao Jianlei , Huang Xi , Tang Wenfu , Ren Ping , Xing Zhihua , Tian Xinqiao , Zhu Zhengyan , Wang Yonggang 
Published: June 2007

AbstractIschemic heart disease (IHD) is the main cause of death and a major public health problem in the world. The traditional herbal medicinal formula Guan‐Xin‐Er‐Hao (GXEH) has been used in China and East Asia for the treatment of coronary heart disease, however, the underlying cardioprotection mechanisms remain unclear. To make clear the antiischemic mechanism involved, GXEH was orally administered to 15 healthy volunteers. Heart rates (HR), blood pressure and coronary flow (CF) velocity before and 1 h after a single oral dose of GXEH were observed and compared. It was demonstrated that the oral administration of GXEH increased CF acutely in a dose‐dependent manner without modification of systemic hemodynamic parameters. Moreover, the myocardial protection function of GXEH was also experimentally examined in ischemia‐reperfusion (I/R) rat models. Apoptosis was measured quantitatively by the terminal transferase UTP nick end‐labeling (TUNEL) method and confirmed by caspase‐3 activity. The infarct size and TUNEL‐positive cells of GXEH‐treated group (20 g/kg) were reduced significantly, which was consistent with the decreased caspase‐3 activity. These suggest that GXEH protects hearts from ischemia injury by increasing CF and reduces infarct size by inhibiting myocardial apoptosis. Copyright © 2007 John Wiley & Sons, Ltd.
Modulation of postsynaptic potentials in rat cortical neurons by valerian extracts macerated with different alcohols: involvement of adenosine A1‐ and GABAA‐receptors
Authors: Sichardt K. , Vissiennon Z. , Koetter U. , Brattström A. , Nieber K. 
Published: June 2007

AbstractValeriana officinalis (valerian) is used traditionally as a mild sedative. Research into valerian is sparse, and studies differ greatly with respect to design, measures and preparations used. This study compares the action of a methanol (M‐E), ethanol (E‐E) and an extract macerated with ethylacetate (EA‐E) from roots of valerian (Valeriana officinalis L., Valerianaceae) on postsynaptic potentials (PSPs) in cortical neurons.Intracellular recordings were performed in rat brain slice preparations containing pyramidal cells of the cingulate cortex. PSPs were induced by electrical field stimulation.The M‐E induced strong inhibition in the concentration range 0.1–15 mg/mL, whereas the E‐E (1–10 mg/mL) did not influence significantly the PSPs. The maximum inhibition induced by the M‐E was completely antagonized by 1,3‐dipropyl‐8‐cyclopentylxanthine (DPCPX, 0.1 µm), an antagonist on the adenosine A1 receptor. Contrary to the M‐E, the EA‐E (10 mg/mL) induced an increase of the PSPs, which was completely blocked by the GABAA receptor antagonist picrotoxin (100 µm).The data suggest that activation of adenosine A1 and GABAA receptors is mediated by different components within the valerian extract. The two mechanisms may contribute independently to the sleep‐inducing effect of valerian. Copyright © 2007 John Wiley & Sons, Ltd.
Development of analytic energy gradient method in nuclear orbital plus molecular orbital theory
Authors: Hoshino Minoru , Tsukamoto Yasuhiro , Nakai Hiromi 
Published: June 2007

AbstractThis study formulates the analytic energy gradients in the Hartree‐Fock calculations of the NOMO theory, which simultaneously determines nuclear and electronic wave functions without the Born‐Oppenheimer approximation. The formulations correspond to the translation‐ and rotation‐contaminated (TRC), translation‐free (TF), and translation‐ and rotation‐free (TRF) treatments. The optimizations of the orbital centers for several diatomic molecules, which have been performed by using the analytic energy gradients, have given the averaged nuclear distances {R0} reflecting the quantum effects of nuclei and the anharmonicity of the potential energy surfaces. The numerical assessments have clarified that the effects of eliminating the translational and rotational contaminations, i.e., the TRF effects are important to improve the evaluations of {R0}, especially for the molecules including hydrogen atoms. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Specific capture of phosphopeptides on matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry targets modified by magnetic affinity nanoparticles
Authors: Tan Feng , Zhang Yangjun , Wang Jinglan , Wei Junying , Qin Peibing , Cai Yun , Qian Xiaohong 
Published: June 2007

AbstractSpecific capture of phosphopeptides from protein digests is a critical step for identification of phosphoproteins by mass spectrometry. In this study, we report a novel phosphopeptide‐capture approach based on the specific interaction of phosphopeptides with a stainless steel target modified with magnetic affinity nanoparticles. The modification which was carried out by loading the suspension of nanoparticles into sample wells of the target did not require any pretreatment procedure to the target and did not involve chemical binding reactions. To isolate phosphopeptides, digests were loaded into the wells of the modified target for 10 min incubation, followed by rinsing with washing buffer to remove unbound species; matrix was then added to the captured phosphopeptides prior to analysis by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS). Capturing the phosphopeptides on the modified target simplified significantly analytical operations and reduced sample loss. This approach has been applied to solution digests of α‐casein, β‐casein, and a mixture of five proteins; a number of phosphopeptides were confidently detected. Phosphopeptides from digests of 10 fmol β‐casein could be isolated and detected by MALDI‐TOFMS with this method. In addition, this approach has been applied successfully to the isolation of phosphopeptides from in‐gel digestive products of sub‐pmol phosphoproteins after separation by sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS‐PAGE). Copyright © 2007 John Wiley & Sons, Ltd.
The impact of social capital on regional waste recycling
Authors: Tsai Tsung‐hsiu 
Published: June 2007

AbstractWaste recycling is a prominent indicator of environmental sustainability in the pursuit of sustainable development. Exploring the determinants of waste recycling is therefore of importance to policy makers. Current research in recycling has explored several important factors to assess household participation in recycling. The local community policy towards recycling is regarded as an important factor, as it can assist households in collecting recyclables as well as implementing innovative recycling programmes. In this paper we look again at the role of community in recycling by asking to what extent a region's degree of social coherence, measured as social capital, would influence its recycling rate. Using Taiwan as a case study we applied the fixed effect model in panel data analysis to estimate the impact of social capital on the regional recycling rate. The estimation shows that the elasticity of social capital to regional recycling rate is about 0.38–0.43 at the 5% significance level. This provides evidence that a region's social relations are highly correlated with its recycling performance; a region's degree of social capital appears to increase its recycling rate. This finding implies that a successful recycling programme requires interactions between society and the environment. Enhancing a region's degree of social capital can also be incorporated as a part of that region's recycling programme. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.
Joint detection of important biomarkers and optimal dose–response model using penalties
Authors: Vandenhende F. , Eilers P. , Ledent E. , Renard D. , Tibaldi F. 
Published: June 2007

AbstractWe propose a method to jointly detect influential biomarkers and estimate how they change with dose. The assessment is made in dose‐ranging trials collecting multiple outcomes for efficacy, safety, pharmacokinetics or pharmacodynamics. We regress all these outcomesversusa non‐parametric transformation of the dose. The regression coefficients and the parameters from the dose–response model are simultaneously estimated using a penalized alternating least‐squares method. We illustrate the technique with a phase I clinical trial and a metabonomic experiment in rats. Copyright © 2007 John Wiley & Sons, Ltd.
A Community Psychology View of Environmental Organization Processes
Authors: Dean Julie H. , Bush Robert A. 
Published: June 2007

AbstractEnvironmental organizations have a key role in addressing environmental degradation and promoting ecologically and socially sustainable societies. Psychosocial processes underpin their work, however, empirical studies of these processes remain underdeveloped. This paper presents the first stage of a community psychology study involving in‐depth interviews with leaders in environmental organizations. Qualitative analysis revealed a framework of five types of psychosocial processes that assist environmental organizations to achieve a range of outcomes, namely: problem analysis; influencing decision‐making; inter‐organizational relationships; community participation and knowledge transfer. These psychosocial processes were used in substantially different ways depending on the organizations' orientation. Three key orientations towards outcomes were evident: on‐ground conservation, developing innovation in specialist areas and transforming wider social institutions. The findings provide a model of the psychosocial processes involved in fostering sustainable futures and exemplify the contribution of community psychology to this critical global issue.
Closing the Achievement Gap: The Association of Racial Climate with Achievement and Behavioral Outcomes
Authors: Mattison Erica , Aber Mark S. 
Published: June 2007

AbstractThis study investigated the relationship between school racial climate and students' self‐reports of academic and discipline outcomes, including whether racial climate mediated and/or moderated the relationship between race and outcomes. Using the Racial Climate Survey‐High School Version (M. Aber et al., unpublished), data were gathered from African American (n = 382) and European American students (n = 1456) regarding their perceptions of racial climate. About 18% of the respondents were low‐income and approximately 50% were male. Positive perceptions of the racial climate were associated with higher student achievement and fewer discipline problems. Further, race moderated the relationship between racial climate and both achievement and discipline outcomes. Finally, racial differences in students' grades and discipline outcomes were associated with differences in perceptions of racial climate. Results suggest careful attention should be given to the racial climate of secondary schools, particularly for adolescents who perceive schools as unfair.