bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of m‐isopropenyl‐α,α‐dimethylbenzyl isocyanate grafted polypropylene on the interfacial interaction of wood‐flour/polypropylene composites
Authors: Guo Chui Gen , Wang Qing Wen
Published: May 2008

In this article, the effects of m‐isopropenyl‐α,α‐dimethylbenzyl isocyanate grafted polypropylene (m‐TMI‐PP) on the interfacial interaction of wood‐flour/polypropylene (WF/PP) were investigated by means of scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetry, dynamic rheological analysis, and mechanical properties tests. The experimental results demonstrated that m‐TMI‐PP greatly improved the interfacial interaction between WF and PP. According to the DSC results, m‐TMI‐PP made the crystallization temperature and the crystallization degree of PP in WF/m‐TMI‐PP/PP decrease when compared with WF/PP composite without m‐TMI‐PP, but it was still higher than pure PP. These results demonstrated that WF presented the nucleate effect for the crystallization of PP and m‐TMI‐PP improved the interfacial adhesive, which restrained the mobility of PP chain. The rheological analysis indicated that the complex viscosity, storage, and loss modular of WF/PP composite increased, and the tan δ decreased with the addition of m‐TMI‐PP. This was attributed to the strong improvement effects of m‐TMI‐PP on the interfacial interaction of the composites, and was further confirmed by the mechanical properties tests and SEM analysis of the composites. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Mechanical damage to estabragh fibers in the production of thermobonded layers
Authors: Gharehaghaji Ali Akbar , Davoodi Sara Hayat
Published: May 2008

Estabragh (Asclepias procerais) fibers are natural, hollow fibers, and the mechanical behavior of these fibers plays a major role in mechanical processing. This work explores the mechanical behavior of estabragh fibers in three different areas—tensile failure, carding behavior, and the construction of nonwoven layers—and reports the main barriers in the spinning process of these fibers. In the first step, a typical stress–strain curve of estabragh fibers is plotted. Fractography of the broken ends by scanning electron microscopy shows the granular nature of the fracture. The likely mechanism of tensile failure is discussed and compared with the fracture of cotton fibers under tensile loading. In the second stage, the carding behavior and likely mechanism of fiber damage during the carding process of estabragh fibers are studied. Both qualitative and quantitative studies show that estabragh fibers experience serious damage during the carding process. The effect of the hollowness of the fibers on their mechanical properties is discussed as well. In the final approach, thermobonded layers of two different blends of estabragh fibers and bicomponent poly(ethylene terephthalate) fibers are produced. Some properties of the produced layers, including moisture absorption, ultraviolet absorption, and bending length, are reported. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Phase behavior and self‐assembly of poly[N‐vinylformamide‐co‐(acrylic acid)] copolymers under highly acidic conditions
Authors: Chen Qiang , Liu Xiaoguang , Xu Kun , Song Chunlei , Zhang Wende , Wang Pixin
Published: May 2008

Copolymers of N‐vinylformamide and acrylic acid were synthesized by conventional aqueous free‐radical polymerization. The phase behavior of the copolymer solutions was investigated through the addition of hydrochloric acid and the variation of the temperature. With a moderate content of N‐vinylformamide, the copolymers showed complex phase behaviors. Under low‐acidity conditions, a suspending liquid was formed, whereas under high‐acidity conditions, the random copolymers could assemble into round nanoparticles with a broad particle size distribution. When the temperature was reduced, a much less cloudy solution that contained nanoparticles became a milk‐like suspending liquid, and this temperature‐responsive phenomenon was reversible. This indicated that the formamide group was protonated under highly acidic conditions; the repulsive electrostatic forces compelled the aggregates to disperse. The amount of salt and excess acid influenced the particle size as well as the temperature‐responsive behavior of the copolymers under highly acidic conditions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation and characterization of blends containing natural and some synthetic rubbers with synthesized aromatic polyester
Authors: El‐Sabbagh S. H. , Tawfik M. E. , Helaly F. M.
Published: May 2008

This work deals with the synthesis of aromatic polyester (AP) from polyarylate [Bisphenol A (BPA)/dimethyl terephalate (DMT)/ethylene glycol (EG)] and maleic anhydride (MA) in presence of dibutyl tin oxide (DBTO) as a catalyst. Blends were prepared from candidated AP (10–30 phr) with different types of rubber [natural rubber (NR), acrylonitrile butadiene rubber (NBR), styrene butadiene rubber (SBR) and ethylene‐propylene‐diene monomer (EPDM)]. The obtained blends were subjected to physicomechanical measurements to evaluate their properties as efficient blends for economic industrial applications. In case of AP blended with rubber, better properties were obtained than that of rubber vulcanizates. The fatigue life values decreases by increasing the AP contents for all types of the tested blends. The equilibrium swelling (%) for the prepared blends exhibits different behavior in solvents like toluene and motor oil. The addition of N‐isopropyl‐N′‐phenyl‐p‐phenylene diamine (IPPD), as antioxidant, affects the properties of all the prepared products. These properties were in consequent with the data of the initial shear modulus, which is calculated from the Mooney‐Rivlin equation and the percentage of the equilibrium swelling. Scanning electron microscope (SEM) was used to study the morphological structure; the SEM results show the changes in surface of the rubber before and after being blended with AP. The investigated blends are considered a new trend in giving products with variable physicomechanical characteristics. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Structural changes of regenerated cellulose dissolved in FeTNa, NaOH/thiourea, and NMMO systems
Authors: El‐Wakil Nahla A. , Hassan Mohammad L.
Published: May 2008

Regenerated cellulose was prepared from microcrystalline cellulose (MCC) via dissolution in three well‐known nonderivatizing systems: ferric chloride/sodium tartarate/sodium hydroxide (FeTNa), sodium hydroxide/thiourea (NaOH/thiourea), and N‐methylmorpholine‐N‐oxide (NMMO) systems. The effect of regeneration using the different systems on the supramolecular structure of the regenerated celluloses was studied using X‐ray diffraction and Fourier transform infrared (FTIR). The effect of regeneration on supermolecular structure, morphology, and thermal stability of regenerated celluloses were studied using scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The effect of regeneration systems used on the chemical reactivity of cellulose toward carboxymethylation, acetylation, and cyanoethylation reactions was briefly studied. The results showed dependence of all the aforementioned properties on the dissolution reagent used in spite of that all studied reagents cause the same change in cellulose crystalline structure (from cellulose I to cellulose II). The degree of polymerization, crystallinity, and thermal stability of the regenerated cellulose (RC) samples were in the following order: NaOH/thiourea RC > FeTNa RC > NMMO RC. SEM micrograph showed unique surface for the NMMO RC sample. The reactivity of the different regenerated cellulose samples toward carboxymethylation, cyanoethylation, and acetylation depended mainly on the reaction system and conditions used rather than on crystallinity of regenerated cellulose. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Quercetin microspheres by solvent evaporation: Preparation, characterization and release behavior
Authors: Scarfato Paola , Avallone Elvira , Iannelli Pio , Aquino Rita P. , Lauro Maria Rosaria , Rossi Alessandra , Acierno Domenico
Published: May 2008

Quercetin (Q) gastro‐resistant microspheres were successfully prepared by solvent evaporation method using cellulose acetate phthalate (C‐A‐P), cellulose acetate propionate (CAP), or their mixtures in different ratios as matrices. The formulation and preparation conditions (stirring speed, polymer concentration, drug‐to‐polymer ratio, temperature) were optimized to obtain high encapsulation efficiency and production yield. The prepared microspheres were submitted to several chemical–physical analyses (light scattering, fluorescence and scanning electron microscopy, X‐ray diffractometry, calorimetry, infrared spectroscopy), to obtain information about particle size distribution, drug loading, and morphology. Moreover, their release properties were investigated performing in vitro dissolution studies with a pH change method. The release tests evidenced that all samples exhibit a fairly gastro‐resistance with a typical biphasic drug release trend, due to the pH‐dependent solubility of the enteric polymers used as matrices. Moreover, the total amount of released quercetin strictly depends on the system composition, increasing with the C‐A‐P percentage in the formulation to such an extent that it is about complete (∼ 90%) in the case of C‐A‐P microspheres. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and characterization of ferromagnetic polyaniline with conductivity in an applied magnetic field
Authors: Zhang Ya , Zhu Chunxia , Kan Jinqing
Published: May 2008

Ferromagnetic polyaniline (PANI) with conductivity was synthesized with peroxydisulfate as an oxidant and horseradish peroxidase as a catalyst in anN′‐a‐hydroxythylpiperazine‐N′‐ethanesulfanic acid buffer solution containing aniline, HCl, and NiCl2·6H2O in an applied magnetic field. The result of an electron paramagnetic resonance spectrum indicated that there were unpaired electrons in the resulting product, the spin density of which was 7.60 × 1019spins/g. The curve of the magnetization versus the magnetic field showed that PANI had soft ferromagnetic behavior at about 300 K. The saturation magnetization and coercive force of PANI were 0.033 emu/g and 5 Oe, respectively. Ultraviolet–visible and Fourier transform infrared spectra indicated that there was interaction between Ni2+and PANI chains but the structure of the backbone chains of PANI synthesized in the presence of a magnetic field hardly changed compared with that of PANI synthesized without NiCl2·6H2O. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Assessment of the ecological status of north‐eastern Adriatic coastal waters (Istria, Croatia) using macroalgal assemblages for the European Union Water Framework Directive
Authors: Iveša Ljiljana , Lyons Daniel Mark , Devescovi Massimo
Published: May 2008

Based on the inclusion of macroalgae in the European Union Water Framework Directive as quality elements for the evaluation of the ecological status of coastal waters, the suitability of one (Ecological Evaluation Index, EEI) of several previously proposed evaluation methods in the particular ecological conditions of the northern Adriatic Sea was tested.

The EEI was assessed for 10 locations (polluted and putatively pristine) scattered along 60 km of the western Istrian coast. The sampling was performed seasonally at 1 and 3 m depth by destructive (determination of species cover and biomass) and non‐destructive (determination of species coverage using digital photography) methods.

When assessed at 1 m depth the spatial scale weighted EEI for the west Istrian coast was 8.1, corresponding to an ecological status class (ESC) value of high. However, data for 3 m depth gave a spatial EEI of 6.72 which corresponds to an ESC value of good. Regressions of the ratio of ecological state group I (ESG I, i.e. thick leathery, calcareous and crustose species) over total algal abundance with the pollution gradient (obtained using principal components analysis (PCA) ordination of environmental variables) were significant at 3 m but not at 1 m depth. This was due to the high abundance of ESG I macroalgae Corallina elongata and Cystoseira compressa at 1 m depth at polluted stations. Similar regressions were obtained using cover, biomass and coverage.

It is concluded that the EEI method may be suitable for the classification of coastal waters in the northern Adriatic only in certain cases. A better assessment of ecological status using this method would require more realistic estimations based on the inclusion of data from several sampling depths. As all three abundance measures (cover, biomass, coverage) gave similar results, coverage (using digital photography) is suggested as being a preferred measure owing to the rapidity of sampling at several depths and less time‐consuming laboratory work.

Copyright © 2008 John Wiley & Sons, Ltd.
The influence of the broadness of a query of a topic on its h‐index: Models and examples of the h‐index of n‐grams
Authors: Egghe Leo , Ravichandra Rao I.K.
Published: May 2008

The article studies the influence of the query formulation of a topic on its h‐index. In order to generate pure random sets of documents, we used N‐grams (N variable) to measure this influence: strings of zeros, truncated at the end. The used databases are WoS and Scopus. The formula ${\rm{h = T}}^{{\textstyle{1 \over \alpha }}} $, proved in Egghe and Rousseau (2006) where T is the number of retrieved documents and α is Lotka's exponent, is confirmed being a concavely increasing function of T. We also give a formula for the relation between h and N the length of the N‐gram: ${\rm{h = D10}}^{ - {\textstyle{{\rm{N}} \over \alpha }}} $ where D is a constant, a convexly decreasing function, which is found in our experiments. Nonlinear regression on ${\rm{h = T}}^{{\textstyle{1 \over \alpha }}} $ gives an estimation of α, which can then be used to estimate the h‐index of the entire database (Web of Science [WoS] and Scopus): ${\rm{h = S}}^{{\textstyle{1 \over \alpha }}} $, where S is the total number of documents in the database.
Self‐citation as an impact‐reinforcing mechanism in the science system
Authors: van Raan Anthony F.J.
Published: May 2008

Previous research has demonstrated that lower performance groups have a larger size‐dependent cumulative advantage for receiving citations than do top‐performance groups. Furthermore, regardless of performance, larger groups have less not‐cited publications. Particularly for the lower performance groups, the fraction of not‐cited publications decreases considerably with size. These phenomena can be explained with a model in which self‐citation acts as a promotion mechanism for external citations. In this article, we show that for self‐citations, similar size‐dependent scaling rules apply as for citations, but generally the power law exponents are higher for self‐citations as compared to citations. We also find that the fraction of self‐citations is smaller for the higher performance groups, and this fraction decreases more rapidly with increasing journal impact than that for lower performance groups. An interesting novel finding is that the variance in the correlation of the number of self‐citations with size is considerably less than the variance for external citations. This is a clear indication that size is a stronger determinant for self‐citations than it is for external citations. Both higher and particularly lower performance groups have a size‐dependent cumulative advantage for self‐citations, but for the higher performance groups only in the lower impact journals and in fields with low citation density.
Pancreatic aplasia in a fetus with asplenia‐cardiovascular defect‐heterotaxy (Ivemark syndrome)
Authors: Konstantinidou Anastasia , Sifakis Stavros , Koukoura Ourania , Mantas Nikitas , Agrogiannis George , Patsouris Efstratios
Published: May 2008

BACKGROUND: Asplenia or polysplenia and complex cardiovascular defects, in association with disturbed body symmetry and malposition of internal organs, constitute the main corpus of malformations in the heterogeneous group of heterotaxy disorders. In affected pregnancies, prenatal diagnosis is possible by ultrasonography, while prognosis and counseling largely depend upon the severity of the cardiac defect. CASE: We present a 25 week gestation fetus with typical findings of asplenia–cardiovascular defect–heterotaxy (Ivemark syndrome) and aplasia of the pancreas. CONCLUSIONS: Pancreatic aplasia emerges as an additional phenotypic feature in Ivemark syndrome and raises the possibility of total pancreatic insufficiency of the affected neonate as an additional, although rare, clinical consideration. Birth Defects Research (Part A) 2008. © 2008 Wiley‐Liss, Inc.
Computer‐Based De Novo Design, Synthesis, and Evaluation of Boronic Acid‐Based Artificial Receptors for Selective Recognition of Dopamine
Authors: Jin Shan , Li Minyong , Zhu Chunyuan , Tran ViLinh , Wang Binghe
Published: May 2008

Dopamine is an important neurotransmitter that plays important roles in various physiological and pathological processes, such as Parkinson's disease. Chemosensors for dopamine have a number of potential applications. On the basis both of the strong and reversible complexation between the boronic acid moiety and a diol functional group and computational chemistry studies, we have designed a series of four compounds for selective three‐point recognition of dopamine, which include boronic acid–diol complexation, aromatic–hydrophobic interactions, and ionic interactions between a carboxylate and a protonated amino group. These compounds were synthesized in seven or eight linear steps and showed dopamine selectivity of up to tenfold over epinephrine. NMR spectroscopy experiments were conducted to probe the structures of the receptor–dopamine complexes. These receptors are the first to show such significant selectivity for dopamine over epinephrine in aqueous solution under near physiological conditions.
“Click‐to‐Chelate”: Design and Incorporation of Triazole‐Containing Metal‐Chelating Systems into Biomolecules of Diagnostic and Therapeutic Interest
Authors: Struthers Harriet , Spingler Bernhard , Mindt Thomas L. , Schibli Roger
Published: May 2008

The site‐specific conjugation of metal chelating systems to biologically relevant molecules is an important contemporary topic in bioinorganic and bioorganometallic chemistry. In this work, we have used the CuI‐catalyzed cycloaddition of azides and terminal alkynes to synthesise novel ligand systems, in which the 1,2,3‐triazole is an integral part of the metal chelating system. A diverse set of bidentate alkyne building blocks with different aliphatic and aromatic backbones and various donor groups were prepared. The bidentate alkynes were reacted with benzyl azide in the presence of a catalytic amount of CuI to form tridentate model ligands. The chelators were reacted with [ReBr3(CO)3]2− to form well‐defined and stable complexes with different overall charges, structures and hydrophilicities. In all cases tridentate coordination of the ligands, including through N3 of the 1,2,3‐triazole ring, was observed. The ligand systems could also be quantitatively radiolabelled with the precursor [99 mTc (H2O)3(CO)3]+ at low ligand concentrations. Similarly the alkynes were reacted with an azido thymidine derivative to form a series of compounds, which could be radiolabelled in situ to form single products. Subsequent incubation of the neutral and cationic organometallic 99 mTc thymidine derivatives with human cytosolic thymidine kinase, a key enzyme in tumour proliferation, revealed that only the neutral compounds maintained substrate activity towards the enzyme. Bioconjugation, radiolabelling and enzymatic reactions were successfully performed in a matter of hours. Thus, click chemistry provides an elegant method for rapidly functionalising a biologically relevant molecule with a variety of efficient metal chelators suitable for (radio)labelling with the M(CO)3 core (M=99 mTc, Re), to offer new potential for technetium‐99 m in clinical and preclinical tracer development.
Protonated Macrobicyclic Hosts Containing Pyridine Head Units for Anion Recognition
Authors: Esteban‐Gómez David , Platas‐Iglesias Carlos , de Blas Andrés , Fabbrizzi Luigi , Rodríguez‐Blas Teresa
Published: May 2008

In this paper, we report two macrobicyclic receptors containing pyridine head units derived from 1,10‐diaza‐15‐crown[5] (L1) or 4,13‐diaza‐18‐crown[6] (L2) that can be protonated in MeCN and used for anion recognition. The interaction of these protonated lateral macrobicycles with different anions has been investigated by means of spectrophotometric titrations in MeCN. The association constants for the complexes of halide anions with the protonated macrobicycles follow the sequences Cl−>Br−>I−>F− (L1) and Cl−>F−>I−>Br− (L2), whereby an increase of more than two logarithmic units is observed from F− to Cl− for the binding constants of the receptor derived from L1. The association constants also indicate an important degree of selectivity of these macrobicyclic receptors for Cl− over Br− or I−. The X‐ray crystal structure analyses of the chloride and bromide complexes confirms the formation of the envisaged supramolecular complexes. Moreover, the binding constants indicate that these receptors present a high sulfate‐to‐nitrate binding selectivity. The stability trend observed for the recognition of halide anions by the macrobicycles presented herein as well as the sulfate‐to‐nitrate binding selectivity have been rationalised by means of DFT calculations at the B3LYP/LanL2DZ level. These studies indicate that the especially high binding selectivity for Cl− is the result of the optimum fit between the protonated macrobicyclic cavity and the size of the anion, whereas the sulfate‐to‐nitrate selectivity results from shape complementarity between the hydrogen‐binding acceptor sites on sulfate and the hydrogen‐bond donors of the macrobicycle.
Conformationally Restricted Dipyrromethene Boron Difluoride (BODIPY) Dyes: Highly Fluorescent, Multicolored Probes for Cellular Imaging
Authors: Zheng Qingdong , Xu Gaixia , Prasad Paras N.
Published: May 2008

Novel fluorescent, conformationally restricted dipyrromethene boron difluoride (BODIPY) dyes have been prepared by introducing a naphthalenyl group at the meso position of the BODIPY core. These BODIPY dyes exhibit increased fluorescence quantum yields compared with dyes that have a meso‐position phenyl group with internal rotation. The absorption and emission wavelengths of such conformationally restricted BODIPY dyes can be easily tuned to the near‐IR range by derivatization through a condensation reaction with benzaldehyde derivatives. The two‐photon absorption properties of these BODIPY dyes were also investigated and the results show that they exhibit increased two‐photon excited fluorescence compared to analogue dyes that contain a phenyl group. The one‐ and two‐photon fluorescence imaging of living cells by using selected BODIPY dyes has been successfully demonstrated.
Statistical mixture modeling for cell subtype identification in flow cytometry
Authors: Chan Cliburn , Feng Feng , Ottinger Janet , Foster David , West Mike , Kepler Thomas B.
Published: May 2008

Statistical mixture modeling provides an opportunity for automated identification and resolution of cell subtypes in flow cytometric data. The configuration of cells as represented by multiple markers simultaneously can be modeled arbitrarily well as a mixture of Gaussian distributions in the dimension of the number of markers. Cellular subtypes may be related to one or multiple components of such mixtures, and fitted mixture models can be evaluated in the full set of markers as an alternative, or adjunct, to traditional subjective gating methods that rely on choosing one or two dimensions. Four color flow data from human blood cells labeled with FITC‐conjugated anti‐CD3, PE‐conjugated anti‐CD8, PE‐Cy5‐conjugated anti‐CD4, and APC‐conjugated anti‐CD19 Abs was acquired on a FACSCalibur. Cells from four murine cell lines, JAWS II, RAW 264.7, CTLL‐2, and A20, were also stained with FITC‐conjugated anti‐CD11c, PE‐conjugated anti‐CD11b, PE‐Cy5‐conjugated anti‐CD8a, and PE‐Cy7‐conjugated‐CD45R/B220 Abs, respectively, and single color flow data were collected on an LSRII. The data were fitted with a mixture of multivariate Gaussians using standard Bayesian statistical approaches and Markov chain Monte Carlo computations. Statistical mixture models were able to identify and purify major cell subsets in human peripheral blood, using an automated process that can be generalized to an arbitrary number of markers. Validation against both traditional expert gating and synthetic mixtures of murine cell lines with known mixing proportions was also performed. This article describes the studies of statistical mixture modeling of flow cytometric data, and demonstrates their utility in examples with four‐color flow data from human peripheral blood samples and synthetic mixtures of murine cell lines. © 2008 International Society for Advancement of Cytometry
Influence of milling conditions on the α‐tocopherol content of Picual olive oil
Authors: Oliveras‐López María Jesús , Granados José Javier Quesada , Bermudo Francisco Martín , de la Serrana Herminia López‐García , Martínez Maria del Carmen López
Published: May 2008

The aim of this study was to estimate the α‐tocopherol content in Picual extra‐virgin olive oils obtained from the 2004/2005 harvesting season and to evaluate the influence that different extraction processes and sample handling had on the final vitamin E content in the oils. A new experimental oil extraction carried out at 9 °C enabled us to obtain encouragingly high quantities of α‐tocopherol with an average quantity reaching 341.34 ± 50.17 mg/L (n = 13), with significant differences among the same oil types produced from the traditional two‐phase system at low (9 °C, p <0.01) and moderate (21.5 °C, p <0.001; 33 °C, p <0.0001) temperatures. The temperature at which extraction was carried out should be considered as a major factor to be taken into account. Additionally, we also developed a precise method for the extraction of α‐tocopherol from olive oil samples, which enables high recovery (96 ± 2%) for use in subsequent HPLC/DAD/fluorescence quantification.
Interaction between amino acid degradation, sensory attributes and lipid peroxidation in wheat rolls
Authors: Römer Julia , Majchrzak Dorota , Elmadfa Ibrahim
Published: May 2008

The influence of lipid peroxidation and heating duration on the amino acid pattern of wheat rolls was assessed in a model baking test. Therefore, three different types of dough were prepared including dough without any fat and two doughs with fat. To estimate the impact of lipid peroxidation products on the amino acid pattern, the two doughs containing fat were both made with rapeseed oil, one with fresh oil, the other with oxidised rapeseed oil. All kinds of dough were baked for three different duration times (18, 24 and 30 min). The lipid peroxidation status of both rapeseed oils was measured with the peroxide value and the p‐anisidine value of the unbaked fat. The amino acid content was analysed by HPLC after acid and alkaline hydrolysis. Besides determining water content and protein content, a sensory analysis was performed. Whereas the amino acid content in the dough without fat was only affected by the baking time, the doughs with rapeseed oil additionally showed a significant increase in amino acid degradation caused by lipid peroxidation products. Especially in the dough prepared with oxidised rapeseed oil, the amino acid content was partly decreased in raw dough without any heating influence. Confirming the influence of lipid peroxidation products in dough prepared with oxidised rapeseed oil, sensory analysis also showed the significantly worst overall score.
Identification of oil palm breeding lines producing oils with low acid values
Authors: Ebongue Georges Frank Ngando , Koona Paul , Nouy Bruno , Zok Simon , Carrière Frédéric , Zollo Paul‐Henri Amvam , Arondel Vincent
Published: May 2008

In the oil palm (Elaeis guineensis Jacq.), an active endogenous lipase is responsible for the massive release of free fatty acids (FFA) in the mesocarp of fruits at maturity. This can lead to the production of oils with unacceptable acid values. We have investigated the lipase activities in 39 genotypes of oil palm presently used in breeding programs. While most E. guineensis genotypes exhibited high lipase activity values, four of them with negligible activities were identified. We analyzed in situ lipolysis in the mesocarp upon severe wounding of fruits. The FFA content of high‐lipase fruits ranged from 17 to 55%, while all low‐lipase fruits contained less than 7.5% FFA. The analysis of oil from fallen overripe fruits indicated that all low‐lipase genotypes contained less than 1.2% FFA (oil acidity <5% FFA, FAO‐WHO international norms), while all but one high‐lipase genotypes had FFA contents much higher than the acceptable standards. Because the identified low‐lipase lines are of high agronomical value and at least one of them is an elite genotype, it will soon be possible to provide farmers with new low‐lipase oil palm lines allowing significant savings on labor costs, without any need for further breeding.
Preparation and Transmetallation of Enantioenriched α‐Aminoorganostannanes Derived from N‐Boc Phenylglycinol: Application to the Synthesis of Alafosfalin
Authors: Coeffard Vincent , Beaudet Isabelle , Evain Michel , Le Grognec Erwan , Quintard Jean‐Paul
Published: May 2008

Enantioenriched tributylstannylated α‐amino alcohols were synthesised by an improved procedure based on ring opening of 2‐tributylstannyloxazolidines. Corresponding α‐amino organolithiums were generated from O‐silylated tributylstannylated α‐amino alcohols and trapped with retention of configuration. Thereby, this methodology was used to synthesise the antibacterial α‐aminophosphonic acid alafosfalin.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Divergent flow isoelectric focusing
Authors: Šlais Karel
Published: May 2008

Continuous‐flow isoelectric focusing (IEF) has the potential to be an important method in proteome analysis. The current devices do not fully use the advantages of IEF, because they do not utilize all its important features including changes in background conductivity during the focusing. A novel continuous‐flow IEF method has been developed based on planar divergent flow and control of local electric field by conductivity of electrode electrolytes. A hydrophilized polypropylene nonwoven fabric was used for creation of flow and electric manifold, making the assembled device cheap, flexible and easy to set up and operate. By using the colored low‐molecular‐weight pI markers we demonstrated much higher speed of focusing in the new designed channel in comparison with a channel based on currently used rectangular geometry. The developed divergent‐flow IEF combines the speed of micro flow channels with the separation efficiency and sample load capacity of preparative devices.
Capillary electrophoresis‐time of flight‐mass spectrometry using noncovalently bilayer‐coated capillaries for the analysis of amino acids in human urine
Authors: Ramautar Rawi , Mayboroda Oleg A. , Derks Rico J. E. , van Nieuwkoop Cees , van Dissel Jaap T. , Somsen Govert W. , Deelder André M. , de Jong Gerhardus J.
Published: May 2008

A capillary electrophoresis‐time of flight‐mass spectrometry (CE‐TOF‐MS) method for the analysis of amino acids in human urine was developed. Capillaries noncovalently coated with a bilayer of Polybrene (PB) and poly(vinyl sulfonate) (PVS) provided a considerable EOF at low pH, thus facilitating the fast separation of amino acids using a BGE of 1 M formic acid (pH 1.8). The PB–PVS coating proved to be very consistent yielding stable CE‐MS patterns of amino acids in urine with favorable migration time repeatability (RSDs <2%). The relatively low sample loading capacity of CE was circumvented by an in‐capillary preconcentration step based on pH‐mediated stacking allowing 100‐nL sample injection (i.e. ca. 4% of capillary volume). As a result, LODs for amino acids were down to 20 nM while achieving satisfactory separation efficiencies. Preliminary validation of the method with urine samples showed good linear responses for the amino acids (R2 >0.99), and RSDs for peak areas were <10%. Special attention was paid to the influence of matrix effects on the quantification of amino acids. The magnitude of ion suppression by the matrix was similar for different urine samples. The CE‐TOF‐MS method was used for the analysis of urine samples of patients with urinary tract infection (UTI). Concentrations of a subset of amino acids were determined and compared with concentrations in urine of healthy controls. Furthermore, partial least squares–discriminant analysis (PLS–DA) of the CE‐TOF‐MS dataset in the 50–450 m/z region showed a distinctive grouping of the UTI samples and the control samples. Examination of score and loadings plot revealed a number of compounds, including phenylalanine, to be responsible for grouping of the samples. Thus, the CE‐TOF‐MS method shows good potential for the screening of body fluids based on the analysis of endogenous low‐molecular weight metabolites such as amino acids and related compounds.
Difference gel electrophoresis analysis of Ras‐transformed fibroblast cell‐derived exosomes
Authors: Ji Hong , Erfani Nasrollah , Tauro Bow J. , Kapp Eugene A. , Zhu Hong‐Jian , Moritz Robert L. , Lim Justin W. E. , Simpson Richard J.
Published: May 2008

Exosomes are membrane vesicles of endocytic origin released by many cell types. The molecular composition of exosomes reflects the specialised functions of their original cells. For example, these vesicles can mediate communication through their ability to bind to target cells, facilitating processes such as vascular homeostasis and antigen presentation. Although the proteomes of exosomes from several cell types are known, exploration of exosomes from additional cell types may improve our understanding of their potential physiological roles. Here, we describe the isolation and characterisation of exosomes isolated from the culture medium of murine fibroblast NIH3T3 cells and Ras‐transformed NIH3T3 cells. The vesicular nature and size (30–100 nm) of the purified fibroblast exosomes was confirmed by electron microscopy. 2‐D difference gel electrophoresis (DIGE) was used to compare protein profiles of exosomes secreted from NIH3T3 cells and Ras‐transformed NIH3T3 cells. LC‐MS/MS sequencing identified proteins in 188 protein spots in the exosomes from the two cell lines, many of which have been previously identified in exosomes from other cell types. However, some proteins identified are novel for fibroblast exosomes, such as Serpin B6. Over 34 proteins, including milk fat globule EGF factor 8 (lactadherin), collagen α‐1 (VI), 14‐3‐3 isoforms, guanine nucleotide‐binding proteins (G proteins), the eukaryotic translation initiation factors elF‐3 γ and elF‐5A accumulated (>2‐fold) in exosomes upon Ras‐induced oncogenic transformation. Significantly, the 10.4‐fold increase in v‐Ha‐Ras p21 protein in exosomes derived from Ras‐transformed NIH3T3 cells suggests that exosome secretion may be implicated in eradication of obsolete proteins.
Effect of surface area during stabilization of electric arc furnace dusts from steel foundries
Authors: Salihoglu Guray , Pinarli Vedat
Published: May 2008

This study examined the effect of waste particle size on stabilization performance of hazardous electric arc furnace dusts (EAFD) from steel foundries through the measurement of the temperature rise during hydration and heavy metals leaching. EAFD was characterized by using scanning electron microscopy (SEM), X‐ray diffraction (XRD), X‐ray fluorescence (XRF), granulometry, and acid neutralization capacity (ANC) analysis. Portland cement was used to stabilize EAFD. Two types of paste samples, with EAFD content varying between 0% and 50% by weight, were prepared. The first type contained original EAFD, and the second contained ground EAFD with increased surface area. The increase in the temperatures of the mixes was monitored during the hydration reactions of the pastes. Ground EAFD yielded higher temperature rise rates than the original EAFD. Heavy metals leaching were determined by toxicity characteristics leaching procedure (TCLP). Pastes containing ground EAFD up to 50% yielded lower zinc and lead leaching than that of samples containing original EAFD. The results revealed that surface area of the EAFD may affect the stabilization performance and therefore care should be given to storage conditions at the foundries. © 2008 American Institute of Chemical Engineers Environ Prog, 2008
Characterization of collagenous matrix assembly in a chondrocyte model system
Authors: Yingst Sorcha , Bloxham Kaci , Warner Lisa R. , Brown Raquel J. , Cole Jennifer , Kenoyer Linda , Knowlton William B. , Oxford Julia Thom
Published: May 2008

Collagen is a major component of the newly synthesized pericellular microenvironment of chondrocytes. Collagen types II, IX, and XI are synthesized and assembled into higher ordered complexes by a mechanism in which type XI collagen plays a role in nucleation of new fibrils, and in limiting fibril diameter. This study utilizes a cell line derived from the Swarm rat chondrosarcoma that allows the accumulation and assembly of pericellular matrix. Immunofluorescence and atomic force microscopy were used to assess early intermediates of fibril formation. Results indicate that this cell line synthesizes and secretes chondrocyte‐specific pericellular matrix molecules including types II, IX, and XI collagen and is suitable for the study of newly synthesized collagen matrix under the experimental conditions used. AFM data indicate that small fibrils or assemblies of microfibrils are detectable and may represent precursors of the ∼20 nm thin fibrils reported in cartilage. Treatment with hyaluronidase indicates that the dimensions of the small fibrils may be dependent upon the presence of hyaluronan within the matrix. This study provides information on the composition and organization of the newly synthesized extracellular matrix that plays a role in establishing the material properties and performance of biological materials such as cartilage. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Carbonate substituted hydroxyapatite: Resorption by osteoclasts modifies the osteoblastic response
Authors: Spence Gavin , Patel Nelesh , Brooks Roger , Rushton Neil
Published: May 2008

Carbonate substitution within the hydroxyapatite (HA) lattice improves osteoconduction, although the mechanism by which this occurs is unclear. Discs of dense, sintered, phase‐pure HA and AB‐type carbonate substituted hydroxyapatite (CHA) were cultured for 21 days with human CD14+ cells in the presence of macrophage‐colony stimulating factor (M‐CSF) and soluble receptor activator of nuclear factor (NF)‐κB (sRANKL), during which time osteoclasts developed and resorbed the ceramic surface. Discs were then seeded with human osteoblasts (HOBs), and proliferation and collagen synthesis were measured. On some discs, the conditioned proteinaceous layer left behind by the osteoclasts was preserved. Proliferation of HOBs was increased on resorbed compared to control (unresorbed) surfaces on both materials, provided this osteoclast‐conditioned layer was left intact. Collagen synthesis by HOBs was increased on previously resorbed surfaces compared to unresorbed surfaces. This effect was seen on both materials but was seen at an earlier time point on CHA. The results suggest that osteoclasts can condition synthetic bioceramic surfaces and alter the responses of osteoblasts that subsequently populate them. Carbonate substitution may enhance osteoconduction indirectly via effects on enhanced bioresorption. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Controlled release of vanadium from titanium oxide coatings for improved integration of soft tissue implants
Authors: Jarrell John D. , Dolly Brandon , Morgan Jeffrey R.
Published: May 2008

This study evaluates the potential of titanium oxide coatings for short‐term delivery of vanadium for improved wound healing around implants. Titanium and vanadium oxides are bioactive agents that elicit different bioresponses in cells, ranging from implant integration and reduction of inflammation to modulation of cell proliferation and morphology. These oxides were combined in biomaterial coatings using metal‐organic precursors and rapidly screened in cell‐culture microplates to establish how vanadium‐loading influences cell proliferation and morphology. Twenty‐eight‐day elution studies indicated that there was a controlled release of vanadium from stable titanium oxide matrices. Elution profiles were mathematically modeled for vanadium loading of 20–1.25% up to a period of 28 days. Scanning electron microscopy and energy dispersive spectroscopy of the coatings indicated that the vanadium was present as a nanoscale dispersion and not segregated micron‐scale islands. The study confirmed that the observed bioresponse of cells was modulated by the soluble release of vanadium into the surrounding medium. Controlled release of vanadium from titania coatings may be used to influence soft‐tissue integration of implants by modulating cell proliferation, attachment, inflammation, and wound healing dynamics. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
A first‐principles DFT study of UN bulk and (001) surface: Comparative LCAO and PW calculations
Authors: Evarestov R. A. , Bandura A. V. , Losev M. V. , Kotomin E. A. , Zhukovskii Yu. F. , Bocharov D.
Published: May 2008

LCAO and PW DFT calculations of the lattice constant, bulk modulus, cohesive energy, charge distribution, band structure, and DOS for UN single crystal are analyzed. It is demonstrated that a choice of the uranium atom relativistic effective core potentials considerably affects the band structure and magnetic structure at low temperatures. All calculations indicate mixed metallic‐covalent chemical bonding in UN crystal with U5f states near the Fermi level. On the basis of the experience accumulated in UN bulk simulations, we compare the atomic and electronic structure as well as the formation energy for UN(001) surface calculated on slabs of different thickness using both DFT approaches. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
Utilizing cool posing narrative and technique as leadership strategies among underrepresented individuals
Authors: Cross, III George M.
Published: May 2008

“Cool posing” narrative and technique—or story and style—has implications for changes in how schools and organizations think about leadership. Cool posing is showing restrained emotion to gain advantages through the use of counterpoint to puzzle and baffle rivals. The intention to be paradoxical and confusing aids the narration of appropriate techniques that offset unfavorable situations and images. Cool posing is as much a part of some underrepresented groups' performance as their sense of self, and as valuable. This strategy is frequently exhibited orally through metaphor, which transforms facts into novel accounts of reality. It is as though the ability to comprehend their experience through cool posing provides many with “the only ways to perceive and experience much of the world” (Lakoff & Johnson, 1980, p. 239). Leaders in schools and organizations could benefit by implementing the strategies suggested here that seek stability and flexibility for those underrepresented individuals traditionally studying, working, and living in less than adequate conditions. Findings suggest the consideration of additional intellectual dimensions aside from the traditional logical and mathematical ones as indicators of valid and reliable aptitude. These further dimensions include the interrelated elements of cool posing, which arespirituality(a vitalistic approach to life),verve(high levels of stimulation),movement(the interweaving of rhythm and dance),harmony(one's fate interrelates with others'),emotion(an emphasis on feelings),orality(a preference for both speaking and listening performances),expressive individualism(the cultivation of spontaneous expression),personal time(the belief that time is passing through a social space), andcommunalism(a commitment to social connectedness) (Boykins, as cited in Majors, 1987/2003a). Leaders need to broaden their ideas of standard leadership and become transformational and transformed to respond to less heard voices that scream as loudly as those that benefit through full representation. Innovative leaders can emerge from underrepresented groups and thrive in industries that become skilled at converting deficit orientations to resource orientations through “patience, a certain flexibility in world view, and a generous tolerance” (Lakoff & Johnson, p. 231). Knowledge from this study may equip teachers and leaders in multiethnic schools and organizations to respond empathetically across racial and ethnic boundaries of difference.
Leadership preferences of a generation Y cohort: A mixed‐methods investigation
Authors: Dulin Linda
Published: May 2008

Presently there are four generational cohorts in the workplace. Born from 1977 to 1997, the youngest cohort group, Generation Y, has 81 million members, of whom over 29 million are already in the workplace. The importance of leader‐subordinate relationships in the workplace has been confirmed. In recognizing this, leaders must identify and adapt to the era‐shaped needs of employees, who cannot fully participate in organizational life if their most urgent needs are not being met. The goal of this study was to determine leadership preferences of a Gen Y cohort as a means to enhance workplace relationships in the 21st‐century organization. A sequential, mixed‐methods study was employed to explore leadership preferences of a Gen Y cohort. Initially, focus‐group interviews were used to generate leadership themes. Based on these themes, an instrument was designed, and Gen Y business students from three higher education institutions were surveyed. Confirmatory factor analysis (CFA) was used to test the themes. Five leadership themes emerged in the focus groups and were confirmed through CFA.
Ossification sequence of the avian order anseriformes, with comparison to other precocial birds
Authors: Maxwell Erin E.
Published: May 2008

Ossification sequences are poorly known for most amniotes, and yet they represent an important source of morphogenetic, phylogenetic, and life history information. Here, the author describes the ossification sequences of three ducks, the Common Eider Somateria mollissima dresseri, the Pekin Duck Anas platyrhynchos, and the Muscovy Duck Cairina moschata. Sequence differences exist both within and among these species, but are generally minor. The Common Eider has the most ossified skeleton prior to hatching, contrary to what is expected in a subarctic migrant species. This may be attributed to a tradeoff between growth rate and locomotory performance. Growth rate is higher in hatchlings with more cartilaginous skeletons, but this may compromise locomotion. No major ossification sequence differences were observed in the craniofacial skeleton when compared with Galliformes, which suggests that the influence of adult morphology on ossification sequence might be relatively minor in many taxa. Galliformes and Anseriformes, while both highly ossified at hatching, differ in the location of their late‐stage ossification centers. In Anseriformes, these are most often located in the appendicular skeleton, whereas in Galliformes they are in the thoracic region and form the ventilatory apparatus. J. Morphol., 2008. © 2008 Wiley‐Liss, Inc.