bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and characterization of layered membranes constructed by sequential redox‐initiated grafting onto polyacrylonitrile ultrafiltration membranes
Authors: Belfer S. , Bottino A. , Capannelli G. 
Published: July 2005

AbstractLayered membranes were prepared by sequential grafting—by means of redox initiators—of water‐soluble monomers, with oppositely charged ionic groups, onto ultrafiltration (UF) polyacrylonitrile (PAN) membranes at room temperature. Grafting of a single layer of 2‐hydroxyethylmethacrylate (HEMA) onto a PAN membrane gave a highly grafted membrane with a relatively high water flux. Bilayered membranes with various properties containing poly‐2‐(dimethylamino)ethyl methacrylate (p‐2DMAEMA) as the bottom layer and polymethacrylic acid or polystyrenesulfonic acid (p‐SSA) as the upper layer were prepared and compared—by means of infrared spectroscopy and electron microscopy—with single‐layered membranes of grafted polyhydroxyethylmethacrylate. Layered membranes exhibited a significant decline in water flux in comparison with the initial UF membranes. The flux could, however, be manipulated by controlling the concentration of monomers, the time of grafting, and the number of layers. When four layers of p‐2DMAEMA and p‐SSA were sequentially grafted onto a PAN membrane, pure water fluxes were stable over a wide range of pH values and did not change over long storage times. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 509–520, 2005
Enzyme electrodes for determination of total phenolic capacity of red wines
Authors: Kıralp S. , Cirpan A. , Toppare L. 
Published: July 2005

AbstractA tyrosinase‐modified electrode, based on physical entrapment of enzyme in copolymer matrix of decanedioic acid bis(4‐pyrrol‐1‐yl‐phenyl) ester (DAPE) with pyrrole was constructed and used to investigate the total amount of phenolics in red wines. Kinetic parameters, Vmax, and Km, were determined. Also, temperature, pH optimizations, operational stability and shelf life of the enzyme electrode were examined. Surface morphologies of the films were studied by scanning electron microscope. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 521–524, 2005
Resins containing amino and carboxylic acid groups. Synthesis, characterization, and metal ion retention properties
Authors: Rivas Bernabé L. , Villegas Sandra 
Published: July 2005

AbstractThe crosslinked poly[3‐(methacryloylamino)propyl]dimethyl(3‐sulfopropyl)ammonium hydroxide], P(MAPDSA), and poly[3‐(methacryloylamino)propyl]dimethyl(3‐sulfopropyl)ammonium hydroxide‐co‐acrylic acid], P(MAPDSA‐co‐AA), were synthesized by radical polymerization. The resins were completely insoluble in water. Due to the lower metal ion retention of P(MAPDSA), the metal ions investigated under competitive and noncompetitive conditions for Cu(II), Cd(II), Hg(II), Zn(II), Pb(II), and Cr(III) ions by batch and column equilibrium procedures were carried out only for P(MAPDA‐co‐AA), particularly for Hg(II). The resin–Hg(II) ion equilibrium was achieved before 15 min. The resin showed a maximum retention capacity value for Hg(II) at pH 2 of 1.89 meq/g. The resin showed a high selectivity to Hg(II) ions. The recovery of the resin was investigated at 25°C with different concentrations of HNO3 and HClO4. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 525–530, 2005
Lightning‐induced magnetic anomalies on archaeological sites
Authors: Jones Geoffrey , Maki David L. 
Published: July 2005

AbstractRecent studies of known lightning impacts and laboratory testing of samples from a suspected lightning‐induced anomaly appearing in magnetic survey data allow us to characterize these formerly enigmatic responses. Remanent magnetization associated with the current path of a lightning discharge produces strong anomalies that can be recognized in magnetic survey data, and can be identified positively using laboratory methods. Copyright © 2005 John Wiley & Sons, Ltd.
Recurrence after segmental resection for colonic Crohn's disease
Authors: Polle S W , Slors J F M , Weverling G J , Gouma D J , Hommes D W , Bemelman W A 
Published: July 2005

Abstract

Background
Segmental colonic resection is commonly performed in patients with colorectal Crohn's disease. The aim of this study was to evaluate the outcome after segmental colonic resection and to define risk factors for re-resection.

Methods
Consecutive patients who had an initial segmental colonic resection for Crohn's colitis between 1987 and 2000 were evaluated. Patients who underwent ileocolonic resection were excluded. Patient-, disease- and treatment-related variables were assessed as possible risk factors for disease recurrence.

Results
Ninety-one patients (62 women) with a median follow-up of 8·3 years were studied. Thirty patients (33 per cent) had at least one re-resection, of whom 20 finally underwent total (procto)colectomy. Female sex and a history of perianal disease were identified as independent risk factors for re-resection: odds ratio 12·52 (95 per cent confidence interval (c.i.) 2·38 to 65·84) and 13·94 (95 per cent c.i. 3·02 to 64·27) respectively. Forty (44 per cent) of the 91 patients had a stoma at the end of the study period. Of the 30 patients who had re-resection, 24 finally had a stoma.

Conclusion
Segmental resection for Crohn's colitis is justified. Recurrence is more frequent in women and in those with a history of perianal disease.
Treatment strategy for patients with colorectal cancer and synchronous irresectable liver metastases
Authors: Benoist S , Pautrat K , Mitry E , Rougier P , Penna C , Nordlinger B 
Published: July 2005

Abstract

Background
The aim of this case-matched study was to determine the best treatment strategy for patients with asymptomatic colorectal cancer and irresectable synchronous liver metastases.

Methods
Between 1997 and 2002, 27 patients with asymptomatic colorectal cancer and irresectable synchronous liver metastases were treated by chemotherapy without initial primary resection (chemotherapy group). These 27 patients were compared with 32 patients matched for age, sex, performance status, primary tumour location, number of liver metastases, nature of irresectable disease and type of chemotherapy, but who were treated initially by resection of primary tumour (resection group).

Results
The 2-year actuarial survival rate was 41 per cent in the chemotherapy group and 44 per cent in the resection group (P = 0·753). In the latter group, the mortality and morbidity rates for primary resection were 0 and 19 per cent (six of 32 patients) respectively. In the chemotherapy group, intestinal obstruction related to the primary tumour occurred in four of 27 patients. The mean overall hospital stay was 11 days in the chemotherapy group and 22 days in the resection group (P = 0·003).

Conclusion
Systemic chemotherapy without resection of the bowel cancer is the option of choice because, for most patients, it is associated with a shorter hospital stay and avoids surgery without a detrimental effect on survival.
Column selection and method development for the separation of nucleoside phosphotriester diastereoisomers, new potential anti‐viral drugs. Application to cellular extract analysis
Authors: Goossens J. F. , Foulon C. , Villard A.‐L. , Puy J.‐Y. , Lefebvre I. , Perigaud C. , Vaccher C. , Bonte J. P. 
Published: July 2005

AbstractAnalytical HPLC methods using derivatized cellulose and amylose chiral stationary phases used in normal and reversed‐phase modes were developed for the diastereoisomeric separation of mononucleotide prodrugs (pronucleotides) of 3′‐azido‐2′,3′‐dideoxythymidine (AZT). The resolutions were performed with two silica‐based celluloses using normal and reversed‐phase methodologies: Tris‐3,5‐dimethylphenylcarbamate (Chiralcel OD‐H and Chiracel OD‐RH) and Tris‐methylbenzoate (Chiralcel OJ and OJ‐R). Two amyloses phases, Tris‐3,5‐dimethylphenylcarbamate (Chiralpak AD) and Tris‐(S)‐1‐phenylethylcarbamate (Chiralpak AS), were used in normal‐phase mode. Additionally, we developed separation using two stationary phases with immobilized cyclodextrins in reversed‐phase and polar‐organic modes. The mobile phase and the chiral stationary phase were varied to achieve the best resolution. Different types and concentration of aliphatic alcohols, acetonitrile or water in the mobile phase were also tested for the different separation modes. An optimal baseline separation (Rs > 1.5) was readily obtained with all silica‐based celluloses and amyloses using a normal‐phase methodology. The different columns gave complementary results in term of resolution. Limits of detection and quantification were 0.12–0.20 and 0.40–0.67 µm, respectively. This analytical method was applied in a preliminary study for the pronucleotide 2 quantification in cellular extract. Copyright © 2005 John Wiley & Sons, Ltd.
The factors that influence the elution order for the resolution of amino acids on vancomycin phase using the polar‐organic mobile phases after their pre‐column derivatization with electrophilic reagents
Authors: Chen S. 
Published: July 2005

AbstractA variety of amino acids were enantioresolved on a vancomycin bonded chiral phase using the polar‐organic mobile phases after their pre‐column derivatization with electrophilic reagents in alkaline medium. The resolution was highly dependent on the analyte's structure and was enhanced as the aromatic side‐chain group on the skeleton of analyte for π–π interaction with the chiral selector became available. The steric hindrance resulting from the bulky side‐chain group on the analyte also affected the resolution. Elution reversal, not found on the teicoplanin phase under the same chromatographic conditions, was possible through altering the type of reagent used in the derivatizing reaction (e.g. 2,4‐difluorophenylisothiocyanate to 2,4‐difluorophenylisocyanate). It is believed that the steric hindrance, as a result of the bulky sulfur atom in reagents such as methylisothiocyanate and others examined in this study, was responsible for the reversed elution order. The bulkiness of the substituent on the aromatic ring of derivatizing reagents (i.e. 2,3‐ and 3,5‐dichlorophenylisothiocyanate) was observed to affect the resolution and alter the elution order as well. Copyright © 2005 John Wiley & Sons, Ltd.
Enantiorecognition on solid chiral selectors using microbatch technology: an example of limitation in case of strong association in the racemate
Authors: Roussel Christian , Rafii Esfandiar , Rio Alberto Del , Vanthuyne Nicolas 
Published: July 2005

AbstractWhen they were independently tested, the enantiomers of N,N′‐bis(salicylidene)‐trans‐1,2‐cyclohexanediamine showed a large difference in adsorption on new chiral selectors using microbatch technology. Surprisingly, when these enantiomers were applied on the same supports as a racemic mixture, no discrimination was observed even though suitable adsorption existed. When a mixture enriched in one enantiomer (scalemic mixture) was applied, the resulting supernatant contained the racemic form and the enantiomer in excess was adsorbed on the support together with a part of racemate. This behavior, which militates in favor of a strong heterochiral dimer formation in the racemate, was revealed using microbatch technology but remained hidden on classical column chromatography on chiral support. Molecular dynamics calculations corroborate this hypothesis, showing a favorite binding mode of the heterochiral dimer, which is stabilized by various inter‐ and intramolecular interactions. Our findings may be considered as a new limitation of microbatch technology, but they may have some inference in case of chiral amplification using the N,N′‐bis(salicylidene)‐trans‐1,2‐cyclohexanediamine enantiomers as chiral ligands. Copyright © 2005 John Wiley & Sons, Ltd.
Synthesis and evaluation of a new biselector s‐triazine based chiral stationary phase for enantioselective HPLC: potentiality of the approach and perspectives
Authors: Lecci Cristina , Iuliano Anna 
Published: July 2005

AbstractA s‐triazine scaffold bearing a free and a protected amino group was used for connecting two different chiral auxiliaries, whose enantiodiscriminating capabilities in enantioselective chromatography are well documented. A biselector system was synthesized and, after linkage to silica gel, used for the chromatographic resolution of different racemic analytes, chosen among the compounds resolved by the two different isolated chiral auxiliaries. The obtained chromatographic results were compared with literature data related to the use of the two chiral stationary phases (CSPs) whose chiral moieties constitute the biselector CSP, allowing us to gain useful information about potentialities and limitations of this approach for obtaining independent CSPs having broader applicability with respect to the classical independent monoselector CSPs. Copyright © 2005 John Wiley & Sons, Ltd.
Application of dimethyl‐β‐cyclodextrin as a chiral selector in capillary electrophoresis for enantiomer separation of ephedrine and related compounds in some drugs
Authors: Liu Li‐Bin , Zheng Zhi‐Xia , Lin Jin‐Ming 
Published: July 2005

AbstractDimethyl‐β‐cyclodextrin (DM‐β‐CD) modified capillary electrophoresis has been developed for chiral separation of ephedrine and related compounds, such as (±)‐norephedrine, (±)‐N‐methylephedrine, (±)‐ephedrine and (+)‐pseudoephedrine. The influence of some crucial parameters such as buffer concentration, pH value, DM‐β‐CD concentration, applied voltage and separation temperature on the separation was investigated. Under the optimum conditions, i.e. 40 mm DM‐β‐CD in 75 mm Tris (pH 2.5) as the running electrolyte, separation voltage +25 kV and temperature 25°C, a satisfactory separation of the enantiomers was accomplished. The detection limits (S/N = 3) ranged from 65 to 161 ng/mL and the linear range was 0.15 to 101.0 µg/mL for pressure injection. The present method was successfully applied for the analysis of a series of drugs such as anti‐tussive, the drug for rheum, the drug for rhinitis and a Chinese traditional herbal medicine, Ephedrae herba (Ma‐Huang in Chinese). The recoveries of ephedrine and related compounds in real samples ranged from 97.6 to 103.5%. This method is useful in the simple and rapid analysis of ephedrine derivatives in marketed products. Copyright © 2005 John Wiley & Sons, Ltd.
Gas chromatographic quantification of free D‐amino acids in higher vertebrates
Authors: Pätzold Ralf , Schieber Andreas , Brückner Hans 
Published: July 2005

AbstractD‐amino acids were determined in brain, body fluids (urine, blood coagulate, serum, plasma) and faeces of animals belonging to nine out of 11 taxonomic orders of vertebrates (Artiodactyla, Aves, Carnivora, Lagomorpha, Marsupalia, Osteichthyes, Primates, Rodentia, Tubilidentata). Free amino acids were isolated by means of cation exchangers and converted into volatile N(O)‐perfluoroacylamino acid propyl esters. Derivatives of amino acids were separated into d‐ and l‐enantiomers using Chirasil‐l‐Val capillary columns and detected by selected ion monitoring mass spectrometry. Quantification of amino acids was achieved by comparison of analytes with amino acid standards using l‐norleucine as internal standard. Large relative amounts of d‐serine were determined in brains of mammals but not of birds. In body fluids the d‐enantiomers of most proteinogenic l‐amino acids were detected, largest absolute and relative amounts were found in urine. Therein quantities of d‐Ala and d‐Ser exceeded 50% relative to the l‐enantiomers in many instances. Feeding animals with diet fortified with dl‐Met resulted in excretion of almost racemic Met in urine. d‐Amino acids were also abundant in faeces of rodents. The data confirm that d‐amino acids are common in body fluids and certain tissues of vertebrates. Copyright © 2005 John Wiley & Sons, Ltd.
Thin‐layer chromatography separation of enantiomers of verapamil using macrocyclic antibiotic as a chiral selector
Authors: Bhushan R. , Gupta Deepak 
Published: July 2005

AbstractSilica gel thin‐layer chromatography plates impregnated with macrocyclic antibiotic, vancomycin, as chiral selector were prepared and used for the resolution of (±)‐verapamil. A mobile phase system of acetonitrile–methanol–water (15:2.5:2.5, v/v) was worked out systematically. The effects of chiral selector, temperature and pH on resolution were also studied. The spots were detected with iodine vapors and the detection limit was found to be 0.074 µg of each enantiomers. Copyright © 2005 John Wiley & Sons, Ltd.
Photostability studies for micellar liquid chromatographic determination of nifedipine in serum and urine samples
Authors: Gil‐Agustí M. T. , Carda‐Broch S. , Ll. Monferrer‐Pons  , Esteve‐Romero J. S. 
Published: July 2005

AbstractNifedipine is a photosensitive compound that is converted into its 4‐(2‐nitrophenyl) pyridine and 4‐(2‐nitrosophenyl) pyridine homologue. In order to obtain the most adequate conditions for handling nifedipine solutions in the analytical laboratory, a number of studies on the decomposition of this compound were performed. A simple micellar liquid chromatographic procedure was described to determine nifedipine in different biological matrices such as serum and urine, and to control its decomposition. To perform the analysis, nifedipine was dissolved in 0.1 m SDS at pH 3 and chromatographed using a mobile phase containing 0.125 m SDS–3% pentanol, pH 3 on a C18 column and UV detection at 235 nm. The chromatographic analysis time was 8 min. The response of the drug for both biological matrices was linear in the 1–100 µg/mL range, with r2 > 0.997 at all times. Repeatability, intermediate precision (CV, %) and limits of quantification and detection (ng/mL) were 0.19, 4.3, 104 and 31 in serum and 0.81, 2.1, 136 and 41 in urine. The method developed here does not show interferences or matrix effects produced by endogenous compounds. Micellar media and mobile phases have the advantage of stabilising the compounds, thus preventing photodegradation and allowing the direct injection of biological samples. Copyright © 2005 John Wiley & Sons, Ltd.
A simple clipping procedure for the dynamic mixed model based on Taylor series approximation
Authors: Kornev N. V. , Tkatchenko I. V. , Hassel E. 
Published: July 2005

AbstractA simple clipping procedure based on Taylor series approximation was suggested to improve the stability of LES computations using the dynamic mixed model (DMM). The clipping procedure derived from a rigorous mathematical analysis uses terms which are anyway determined in the DMM model and thus, does not require additional calculations. The effect of the clipping was tested by calculations of turbulent mixing in a coaxial jet mixer. The suggested procedure has potential to be extended to LES of complex‐geometry turbulent flows. Copyright © 2005 John Wiley & Sons, Ltd.
Valence Tautomerism: New Challenges for Electroactive Ligands (Eur. J. Inorg. Chem. 15/2005)
Authors: Evangelio Emilia , Ruiz‐Molina Daniel 
Published: July 2005

AbstractThe cover picture shows the potential energy curves for a generic valence tautomeric complex with a schematic representation emphasizing the intramolecular electron transfer between the metal ion and the ligand, which can be induced by different external stimuli such as temperature, pressure or irradiation. The diagram is accompanied by a representation of the different redox‐active ligands involved in valence tautomerism that are presented in the Microreview by E. Evangelio and D. Ruiz‐Molina on p. 2957 ff.
Parametric study on the batch leaching process of Jojoba oil
Authors: Allawzi Mamdouh A. , Abu‐Arabi Mousa K. , Al‐Taher Faraj A. 
Published: July 2005

AbstractIn this study, hexane is used as solvent to extract Jojoba oil in a batch leaching process. The effects of temperature, mixing speed, particle size and solvent‐to‐seed ratio on Jojoba oil extraction were investigated. The best recovery of oil was obtained when the parameters investigated were at the boiling point temperature of the solvent, a particle size of 0.48 mm, a mixing speed of 1000 rpm, and a solvent‐to‐seed ratio of 15 mL/g. The maximum amount extracted was 55 wt‐% under the above‐mentioned operating conditions. The amount extracted at a higher particle size (1.5 mm) was around 44 wt‐%. An empirical model was obtained based on the experimental data, in order to predict the extraction yield under the operating conditions. The derived model is in good agreement with the experimental data, with a maximum deviation of 8%.
Incorporation of γ‐linolenic and linoleic acids into a palm kernel oil/palm olein blend
Authors: Lumor Stephen E. , Akoh Casimir C. 
Published: July 2005

AbstractLipozyme RM IM, a 1,3‐regiospecific lipase, was used as a biocatalyst for the incorporation of γ‐linolenic acid (GLA) and linoleic acid (LA) from borage oil into a blend of palm kernel oil and palm olein (50:50, vol/vol). GLA and LA were concentrated as non‐urea‐complex fatty acids (NUCFA) and NUCFA ethyl esters (NUCFAEE) by urea fractionation. Acidolysis and interesterification were conducted in a solvent‐free system with NUCFA and NUCFAEE as acyl donors, respectively. The effects of temperature and substrate mole ratio on incorporation were also studied. Products were analyzed by gas chromatography. NUCFA were a better substrate for GLA incorporation at 45, 55, and 65 °C. The highest incorporation (16.79%) was obtained at 55 °C. NUCFAEE were a better substrate at 75 °C, with 25.06% GLA incorporation compared to 14.09% with NUCFA. Generally, incorporation increased with increasing substrate mole ratio. A structured lipid containing 33% GLA and 9.4% LA was produced with NUCFAEE as acyl donor at 75 °C and a substrate mole ratio of 4.5. Our work showed that the substrate mole ratio was the most important factor affecting incorporation, and the suitability of either substrate as acyl donor was temperature dependent. The enzyme's preference for GLA incorporation over LA was also observed.
Antioxidant properties of extracts and compounds from Psoralea morisiana
Authors: Rosa Antonella , Deiana Monica , Corona Giulia , Atzeri Angela , Incani Alessandra , Appendino Giovanni , Dessì M. Assunta 
Published: July 2005

AbstractThe antioxidant activity of various extracts (MeOH, petroleum ether, EtOAc) from the aerial parts of Psoralea morisiana, an endemic Sardinian plant, was evaluated during autoxidation and iron‐mediated oxidation of linoleic acid at 37 °C and during cholesterol oxidation at 140 °C, in the absence of solvent. The activity of erybraedin C, bitucarpin A and plicatin B, isolated from the extracts, was investigated under the same experimental conditions and compared to that of BHT and α‐tocopherol. All the extracts, erybraedin C (major constituent of the extracts) and plicatin B showed powerful antioxidant properties. None of the extracts and pure compounds showed any prooxidant activity. The cytotoxicity of the extracts, erybraedin C, and plicatin B was further evaluated in VERO cells, a line of fibroblasts derived from monkey kidney. Erybraedin C, at non‐cytotoxic concentrations, showed a strong inhibition of FeCl3‐induced oxidation in VERO cells.
Exciting Supramolecular Architectures: Light‐Induced Processes and Synthetic Transformations in Noncovalent Assemblies
Authors: Huang Chih‐Hao , Bassani Dario M. 
Published: July 2005

AbstractThis review outlines recent advances in the area of supramolecular photochemistry, particularly with respect to the use of noncovalent interactions to direct and control excited‐state processes in the solid phase and in solution. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)