bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Synopsis of recent attempts toward construction of rechargeable batteries utilizing conducting polymer cathodes and anodes
Authors: Levi M. D. , Gofer Y. , Aurbach D. 
Published: January 2003

AbstractThis paper reports on our recent attempts in the characterization of n‐doping of polythiophene (PTh) and p‐doping of polypyrrole (PPy) for their use as the anode and cathode, respectively, for rechargeable batteries. N‐doping of PTh with large (TEA) cations was studied by combined application of cyclic voltammetry, in situ conductometry and ex situ atomic force microcopy (AFM). The average potential for n‐doping of PTh was close to 1.2 V (versus Li/Li+). Substantial trapping of negatively charged polarons was observed during consecutive n‐doping. Addition of Li‐salt to the background electrolyte, even in a small concentration, resulted in the almost complete deactivation of the film with respect to n‐doping. We suggest that the above drawback can be overcome by using the more robust fluorosubstituted polyphenyl(thiophene), P3FPhTh. On the other hand, when addressing polymer cathodes, specially prepared PPy films showed highly reversible behavior and a large capacity of up to one electron per ring (or 420 mAh per gram of neutral polymer) when cycled up to 4.6–4.7 V (versus Li/Li+). Only above 5 V (versus Li/Li+) did an irreversible over‐oxidation of PPy occur. Electrochemical characteristics of p‐doped PPy cathode are compared with that of lithiated V2O5 film. Two possible alternative ways for changing the dopants in p‐doped PPy, from anions to cations, are discussed. Copyright © 2003 John Wiley & Sons, Ltd.
Flame‐retarded polyolefin systems of controlled interphase
Authors: Marosi Gy. , Anna P. , Márton A. , Bertalan Gy. , Bóta A. , Tóth A. , Mohai M. , Rácz I. 
Published: January 2003

AbstractThe principle of multilayer interphases was proposed earlier for modifying the mechanical properties and UV stability of various multicomponent polymer systems. This paper focuses on the applicability of this principle for improving the performance of intumescent flame‐retardant systems using melamine‐treated ammonium polyphosphate, silicone modified polyol + ammonium polyphosphate, and silicone modified nanoparticles in polypropylene. The structure–property relationship of the formed systems was studied. A melamine layer of 1.45 nm thickness was formed around ammonium polyphosphate in order to improve the hygrothermal stability, but this layer was not shear‐resistant enough. An interphase formed using a special silicone additive is more stable and acts with the intumescent flame‐retardant system synergistically. The advantageous interfacial structure is quite complex in this case: polyphosphate particles are surrounded with a macromolecular layer formed from polyol, silicone, and reactive surfactant in order to ensure good stability, efficiency and compatibility. AFM, XPS and a Cone Calorimeter were used for determining the structure and flame‐retardancy of these systems. Nanocomposites combined with silicone‐containing intumescent system were developed in order to avoid dipping at ignition in the vertical position. SAXS and µ‐TA methods were used for determining the structure of this material. Copyright ­© 2003 John Wiley & Sons, Ltd.
Functionalization of gold electrode surface with heterobifunctional poly(ethylene oxide)s having both mercapto and aldehyde groups
Authors: Kurusu Fumiyo , Ohno Hiroyuki , Kaneko Mitsuhiro , Nagasaki Yukio , Kataoka Kazunori 
Published: January 2003

AbstractWe synthesized heterobifunctional poly(ethylene oxide) (PEO) (α‐formyl‐ω‐mercapto‐PEO; CHO‐PEO400‐SH, average molecular weight of PEO part being 400), which had both an aldehyde group as a binding site with amino group of protein and a mercapto group for gold electrode surface. The CHO‐PEO400‐SH was adsorbed on a gold electrode surface and cytochrome c (cyt.c) was fixed on this modified electrode. The redox response of covalently immobilized cyt.c was observed on the cyclic voltammetry measurement, showing that CHO‐PEO400‐SH can be used as a linker to fix cyt.c on an electrode. Another type of heterobifunctional PEO (α‐formyl‐ω‐(2‐pyridyldithio)‐PEO; CHO‐PEO300‐SS‐Py), which had an aldehyde group and a 2‐pyridinethiol (2‐Py) through disulfide bond, was synthesized to form co‐adsorbed monolayer of PEO chain and 2‐Py on an electrode surface. It was expected, due to the spacer with shorter PEO chain and lower surface density, that better redox response of the fixed cyt.c was obtained. However, the redox response of fixed cyt.c was not detected on the CHO‐PEO300‐SS‐Py modified gold electrode. Instead, this heterobifunctional PEO was found to function as a good promoter for cyt.c dissolved in phosphate buffer solution. Copyright © 2003 John Wiley & Sons, Ltd.
Determination of saponins and alkaloids in Caulophyllum thalictroides (blue cohosh) by high‐performance liquid chromatography and evaporative light scattering detection
Authors: Ganzera M. , Dharmaratne H. R. W. , Nanayakkara N. P. D. , Khan I. A. 
Published: January 2003

AbstractThe roots of Caulophyllum thalictroides, traditionally used for the treatment of menstrual difficulties and as an aid in childbirth, contain saponins, which are considered to be responsible for the uterine stimulant effects, together with teratogenic alkaloids. An HPLC method has been developed which permits the determination of the triterpene saponins in the plant and also the separation of four alkaloids. The best results were obtained with a C‐12 stationary phase using ammonium acetate buffer (pH 8.0) and acetonitrile as mobile phase. Owing to their low UV absorbance, the saponins were detected by evaporative light scattering, whereas the alkaloids were monitored by UV at 310 nm. The identities of the compounds were confirmed in an LC‐MS experiment. Different plant samples and commercial products have been analysed using the described method, and remarkable qualitative and quantitative variations were revealed. Comparing the daily uptake of total saponins, a difference of greater than 100‐fold was observed within the various products; the alkaloid content on the other hand was more uniform. Copyright © 2003 John Wiley & Sons, Ltd.
Fungitoxic phenols from carnation (Dianthus caryophyllus) effective against Fusarium oxysporum f. sp. dianthi
Authors: Curir Paolo , Dolci Marcello , Dolci Paola , Lanzotti Virginia , Cooman Luc De 
Published: January 2003

AbstractThe phenol compositions of two cultivars of carnation (Dianthus caryophyllus) namely “Gloriana” and “Roland”, which are partially and highly resistant, respectively, to Fusarium oxysporum f. sp. dianthi have been investigated with the aim of determining if endogenous phenols could have an anti‐fungal effect against the pathogen. Analyses were performed on healthy and F. oxysporum‐inoculated in vitro tissues, and on in vivo plants. Two benzoic acid derivatives, protocatechuic acid (3,4‐dihydroxybenzoic acid) and vanillic acid (4‐hydroxy‐3‐methoxybenzoic acid), were found within healthy and inoculated tissues of both cultivars, together with the flavonol glycoside peltatoside (3‐[6‐O‐(α‐L‐arabinopyranosyl)‐β‐D‐glucopyranosyl] quercetin). These molecules proved to be only slightly inhibitory towards the pathogen. 2,6‐Dimethoxybenzoic acid was detected in small amounts only in the inoculated cultivar “Gloriana”, while the highly resistant cultivar “Roland” showed the presence of the flavone datiscetin (3,5,7,2′‐tetrahydroxyflavone). The latter compound exhibited an appreciable fungitoxic activity towards F. oxysporum f. sp. dianthi. Copyright © 2003 John Wiley & Sons, Ltd.
HPLC isolation of the anti‐plasmodially active bisbenzylisoquinone alkaloids present in roots of Cissampelos mucronata
Authors: Tshibangu Jeannette Ndaya , Wright Anthony D. , König Gabriele M. 
Published: January 2003

AbstractThe methanolic extract of dried, powdered Cissampelos mucronata roots possesses significant in vitro activity against Plasmodium falciparum. In order to enable further pharmacological testing, the substances responsible for the observed activity were purified, mainly by HPLC, using various stationary and mobile phases. The active principles were determined to be a series of bisbenzylisoquinoline alkaloids, a group of natural products for which one of the first routine preparative HPLC separation methods is described. Copyright © 2003 John Wiley & Sons, Ltd.
Analysis of volatile fractions of Schisandra chinensis (Turcz.) Baill. using GC‐MS and chemometric resolution
Authors: Li Xiao‐Ning , Cui Hui , Song You‐Qun , Liang Yi‐Zeng , Chau Foo‐Tim 
Published: January 2003

AbstractThe two‐dimensional data obtained from GC‐MS has been used qualitatively and quantitatively to determine the components of the volatile fractions of Schisandra chinensis obtained by six different extraction methods. Sub‐window factor analysis (SFA) was employed to confirm the identities of components determined in different samples. With the help of SFA, and other chemometric techniques, peak purity in the chromatograms was determined, and overlapping peaks were resolved to yield a pure chromatographic profile and mass spectrum for each component. It is demonstrated that the accuracy of qualitative and quantitative analysis may be greatly enhanced using chemometric resolution methods, such methods being particularly valuable with respect to the analysis of complex samples such as traditional Chinese medicines. It is further demonstrated that different extraction methods give rise to volatile fractions of S. chinensis which differ qualitatively and quantitatively in their composition. Copyright © 2003 John Wiley & Sons, Ltd.
Determination of the absolute configuration of 6‐alkylated α‐pyrones from Ravensara crassifolia by LC‐NMR
Authors: Queiroz E. F. , Wolfender J.‐L. , Raoelison G. , Hostettmann K. 
Published: January 2003

AbstractThe absolute configuration of asymmetric centres of two α‐pyrones isolated from Ravensara crassifolia was determined using the Mosher method. The conventional analysis of the purified ester derivatives by 1H‐NMR was replaced by a rapid and sensitive method in which the α‐pyrones were analysed under isocratic reversed‐phase LC‐NMR conditions prior to and after derivatisation reactions. Comparison of the LC‐1H‐NMR spectra of the actual α‐pyrones with those of the corresponding Mosher's esters recorded in the acetonitrile:deuterated water solvent system exhibited shifts comparable with those obtained using conventional deuterated solvents. Based on the shifts recorded, determination of the absolute configuration was possible by application of Mosher rules. The use of LC‐NMR has permitted a direct analysis of crude reaction mixtures containing less than 50 µg of the starting material. Completion of the reaction was checked by LC‐MS and the crude reaction mixture was analysed by stop‐flow LC‐NMR. This methodology seems very promising for the determination at the micro‐scale level of the absolute configuration of natural products which are available only in very small amounts. Copyright © 2003 John Wiley & Sons, Ltd.
Identification and characterisation of the Chinese herb Langdu by LC‐MS/MS analysis
Authors: Su Xiao‐Li , Lin Rui‐Chao , Wong Siu‐Kay , Tsui Shu‐Ki , Kwan Sik‐Yiu 
Published: January 2003

AbstractAn LC‐MS/MS method has been developed for the identification of three species of herb used as the traditional Chinese medicine Langdu, namely Stellera chamaejasme L., Euphorbia ebracteolata Hayata and E. fischeriana Steud. As these herbs contain different mixtures of marker compounds, they could be unambiguously differentiated from each other by comparing their respective characteristic segmental multiple reaction monitoring profiles. The profiles indicated that S. chamaejasme contained daphnetin, skimmetine, stellerin, chamaechromone and neochamaejasmin, E. fischeriana contained ebracteolata compound B, ingenol, jolkinolide B and fischeriana A, whilst E. ebracteolata contained ebracteolata compounds B and C along with ingenol. These results were confirmed from the respective MS/MS spectra. The method has been successfully applied to differentiate these herbs from the related species Alocasia macrorrhiza (L.) Schott and E. kansui Liou. Copyright © 2003 John Wiley & Sons, Ltd.
Guaiacylglycerol‐7′‐O‐methyl 8′‐vanillic acid ether and related compounds from Boreava orientalis
Authors: Sakushima Akiyo , Ohno Kosei , Maoka Takashi , Coskun Maksut , Guvenc Aysegul , Erdurak Ceyda Sibel , Ozkan Ayse Mine , Seki Koh‐ichi , Ohkura Kazue 
Published: January 2003

AbstractThe threo and erythro forms of guaiacylglycerol‐7′‐O‐methyl 8′‐vanillic acid ethers, threo and erythro guaiacylglycerol 8′‐vanillin ethers, and threo guaiacylglycerol 8′‐(4‐hydroxymethyl‐2‐methoxyphenyl) ether have been isolated from fruits of Boreava orientalis. Structural determinations were made on the basis of UV, MS, 1H‐ and 13C‐NMR spectral data, including two‐dimensional shift correlation. The relative configurations were assigned on the basis of 1H‐NMR chemical shifts. Copyright © 2003 John Wiley & Sons, Ltd.
HPLC‐NMR/HPLC‐MS analysis of the bark extract of Stauranthus perforatus
Authors: Setzer William N. , Vogler Bernhard , Bates Robert B. , Schmidt Jennifer M. , Dicus Christopher W. , Nakkiew Pichaya , Haber William A. 
Published: January 2003

AbstractA combination of HPLC‐MS and HPLC‐NMR techniques has been used to analyse the cytotoxic fractions of the dichloromethane extract of bark of Stauranthus perforatus. Six furanocoumarins (byakangelicol, heraclenin, heraclenol, imperatorin, isopimpinellin and xanthotoxin) and nine quinoline alkaloids (two known compounds, veprisine and 5‐hydroxy‐1‐methyl‐2‐phenyl‐4‐quinolone, along with seven novel compounds, stauranthine, 3′,4′‐dihydroxy‐3′,4′‐dihydroveprisine, 3′,4′‐dihydroxy‐3′,4′‐dihydrostauranthine, 3′,6′‐dihydroxy‐3′,6′‐dihydroveprisine, 3′,6′‐dihydroxy‐3′,6′‐dihydrostauranthine, 6′‐hydroxy‐3′‐ketoveprisine and 6′‐hydroxy‐3′‐ketostauranthine) have been identified in the fractions. Copyright © 2003 John Wiley & Sons, Ltd.
Phase behaviour of methylcellulose–poly(acrylic acid) blends and preparation of related hydrophilic films
Authors: Khutoryanskiy Vitaliy V , Cascone Maria Grazia , Lazzeri Luigi , Nurkeeva Zauresh S , Mun Grigoriy A , Mangazbaeva Rauash A 
Published: January 2003

AbstractThe phase behavior of methylcellulose‐poly(acrylic acid) mixtures was studied in aqueous solution. It was shown that the complexation between the two polymers decreases considerably the cloud‐point of methylcellulose. The addition of inorganic salts shifts the critical pH values toward a higher pH region. Films were prepared based on methylcellulose‐poly(acrylic acid) blends and were analyzed by dynamic mechanical thermal analysis, scanning electron microscopy and thermal gravimetric analysis. The miscibility between the two polymers in the films was shown. It was found that the thermal treatment of the films leads to their cross‐linking with the formation of materials swellable both in water and ethanol.© 2003 Society of Chemical Industry
Grafting polythiophene on polyethylene surfaces
Authors: Chanunpanich N , Ulman A , Strzhemechny Y M , Schwarz S A , Dormicik J , Janke A , Braun H G , Kratzmüller T 
Published: January 2003

AbstractPolythiophene (PT) was grafted on PE film using three reaction steps. First, PE films were brominated in the gas phase, yielding PE–Br; second, a substitution reaction of PE–Br with 2‐thiophene thiolate anion gave the thiophene‐functionalized PE; finally PT was grafted on the PE surface using chemical oxidative polymerization to give PE–PT. The polymerization was carried out in a suspension solution of anhydrous FeCl3 in CHCl3, yielding a reddish PE–PT film after dedoping with ethanol. ATR‐FTIR shows that the PT was grafted on PE in the 2,5‐position. SEM imaging revealed islands of PT on the PE film. AFM analysis found the thickness of islands to be in the range of 120–145 nm. The conductivity of these thin films was in the range of 10−6 S cm−1, a significant increase from the value of ∼10−14 S cm−1 measured for PE film.© 2003 Society of Chemical Industry
Synthesis and characterization of ABA type tri‐block copolymers derived from p‐dioxanone, L‐lactide and poly(ethylene glycol)
Authors: Bhattarai Narayan , Kim Hak Yong , Lee Douk Rae , Park Soo‐Jin 
Published: January 2003

AbstractA series of triblock co‐polymers, consisting of a poly(ethylene glycol) (PEG) central block joined to two blocks of random p‐dioxanone‐co‐L‐lactide copolymers were synthesized by ring‐opening polymerization of p‐dioxanone (PDO) and L‐lactide (LLA) initiated by PEG in the presence of stannous 2‐ethylhexanoate catalyst. The resulting copolymers were characterized by various techniques including 1H and 13C NMR and FTIR spectroscopies, gel permeation chromatography, inherent viscosity, wide‐angle X‐ray diffractometry (WAXD) and differential scanning calorimetry (DSC). The conversion of PDO and L‐lactide into the polymer was studied various mole ratios and at different polymerization temperature from 1H NMR spectra. Results of WAXD and DSC showed that the crystallinity of PEG macroinitiator was greatly influenced by the composition of PDO and L‐lactide in the copolymer. The triblock copolymers with low molecular weight were soluble in water at below room temperature.© 2003 Society of Chemical Industry
Effect of filler–filler interaction on rheological behaviour of natural rubber compounds filled with both carbon black and silica
Authors: Choi Sung‐Seen , Nah Changwoon , Lee Seung Goo , Joo Chang Whan 
Published: January 2003

AbstractRubber compounds are reinforced with fillers such as carbon black and silica. In general, filled rubber compounds show smooth rheological behaviour in measurement of Mooney viscosity or Mooney scorch time. Variation in rheological behaviour was studied in terms of the filler composition using natural rubber compounds filled with both carbon black and silica (carbon black/silica = 60/20,40/40, and 20/60 phr). The compound filled with carbon black/silica of 60/20 phr showed normal rheological behaviour. However, the compounds filled with carbon black/silica of 40/40 and 20/60 phr showed abnormal rheological behaviour, in which the viscosity increased suddenly and then decreased at a certain point during the measurement. The abnormal behaviour was explained by the strong filler–filler interaction of silica. Moreover, the abnormal rheological behaviour was displayed more clearly as the storage time of compounds is increased.© 2003 Society of Chemical Industry
Determination of intrinsic physical constants of poly(trimethylene terephthalate) from drawn filament
Authors: Kim Kap Jin , Bae Joon Hyung , Kim Young Ho 
Published: January 2003

AbstractThe intrinsic lateral sonic moduli of the crystalline and amorphous regions of poly(trimethylene terephthalate) (3GT) (about 4.1504 ± 0.8396 GPa and 1.6096 ± 0.0368 GPa, respectively) were obtained from sonic moduli and crystallinities of unoriented 3GT filaments annealed under different conditions. Using the obtained intrinsic lateral sonic moduli of the crystalline and amorphous regions, the degree of orientation of the amorphous region of uniaxially drawn 3GT filaments could also be obtained from the crystallinity, sonic modulus, and the degree of crystalline orientation estimated from X‐ray azimuthal scan data. Thus, the intrinsic birefringences of the perfectly oriented crystalline and amorphous regions of the 3GT fibre (about 0.2057 ± 0.0160 and 0.2175 ± 0.0923, respectively) could be obtained from the appropriate combinations of birefringence, crystallinity, and the degree of orientation of the crystalline and amorphous regions.© 2003 Society of Chemical Industry
Expanding the organismal scope of proteomics: Cross‐species protein identification by mass spectrometry and its implications
Authors: Liska Adam J. , Shevchenko Andrej 
Published: January 2003

AbstractDue to the limited applicability of conventional protein identification methods to the proteomes of organisms with unsequenced genomes, researchers have developed approaches to identify proteins using mass spectrometry and sequence similarity database searches. Both the integration of mass spectrometry with bioinformatics and genomic sequencing drive the expanding organismal scope of proteomics.
Application of immunoproteomics to analysis of post‐translational processing of the antiphagocytic M protein of Streptococcus
Authors: Romer Terence G. , Boyle Michael D. P. 
Published: January 2003

AbstractPost‐translational modification of the antiphagocytic M1 protein of Streptococcus pyogenes can influence its binding properties for human immunoglobulin G subclasses and its invasive potential. Current methods of monitoring this modification event involve N‐terminal sequencing and are cumbersome, slow and not amenable to routine analysis. In this study we demonstrate that surface enhanced laser desorption/ionization‐time of flight mass spectrometry can be used to monitor modification of the M1 protein by the secreted bacterial cysteine protease, SpeB. This method, when combined with a specific antibody capture step provides a specific, rapid and sensitive assay for key virulence factors of the important human pathogen Streptococcus pyogenes.
A novel experimental design for comparative two‐dimensional gel analysis: Two‐dimensional difference gel electrophoresis incorporating a pooled internal standard
Authors: Alban Andrew , David Stephen Olu , Bjorkesten Lennart , Andersson Christian , Sloge Erik , Lewis Steve , Currie Ian 
Published: January 2003

AbstractThe comparison of two‐dimensional (2‐D) gel images from different samples is an established method used to study differences in protein expression. Conventional methods rely on comparing images from at least 2 different gels. Due to the high variation between gels, detection and quantification of protein differences can be problematic. Two‐dimensional difference gel electrophoresis (Ettan™ DIGE) is an emerging technique for comparative proteomics, which improves the reproducibility and reliability of differential protein expression analysis between samples. In the application of DIGE different samples are labelled with mass and charge matched spectrally resolvable fluorescent dyes and are then separated on the same 2‐D gel. Using an Escherichia coli lysate “spiked” with varying amounts of four different known proteins, we have tested a novel experimental design that exploits the sample multiplexing capabilities of DIGE, by including a standard sample in each gel. The standard sample comprises equal amounts of each sample to be compared and was found to improve the accuracy of protein quantification between samples from different gels allowing accurate detection of small differences in protein levels between samples.