bluuebunny/crossref_metadata_2025_split huggingface dataset:
Liquid chromatography/mass spectrometry for metabonomics investigation of the biochemical effects induced by aristolochic acid in rats: the use of information‐dependent acquisition for biomarker identification
Authors: Chan Wan , Lee Kim‐Chung , Liu Ning , Wong Ricky N. S. , Liu Huwei , Cai Zongwei 
Published: February 2008

AbstractThe toxic effects of oral administrations of nephrotoxic and carcinogenic aristolochic acid (AA) to male Sprague‐Dawley rats were investigated by using high‐performance liquid chromatography coupled with a quadrupole time‐of‐flight mass spectrometer. Analysis of the urine and plasma samples revealed distinct changes in the biochemical patterns in the AA‐dosed rats. After peak finding and alignment, principal component analysis (PCA) and partial least‐squares discriminant analysis (PLS‐DA) were used for multivariate data analysis. Potential biomarkers were studied by high‐resolution mass spectrometry (MS) and tandem mass spectrometry (MS/MS) analyses. The MS/MS spectra of all endogenous metabolites satisfying the pre‐defined criteria were acquired in a single information‐dependent acquisition (IDA) analysis, demonstrating that IDA was an efficient approach for structural elucidation in metabonomic studies. Citric acid and a glucuronide‐containing metabolite were observed as potential biomarkers in rat urine. A significant increase in plasma creatinine concentration was also observed in the AA‐dosed rats, which indicated that AA induced an adverse effect on the renal clearance function. Copyright © 2008 John Wiley & Sons, Ltd.
On‐line monitoring of Brookhart polymerization by electrospray ionization mass spectrometry
Authors: Santos Leonardo Silva , Metzger Jürgen O. 
Published: February 2008

AbstractFor the first time, an electrospray ionization (ESI) mass spectrometer coupled on‐line with a microreactor permitted the fast screening of polymerization growth of alkenes in the liquid phase mediated by palladium Brookhart catalyst and allowed the direct mass spectrometric identification of alkyl chains still bonded to Pd. The method also allowed us to intercept the catalytically active cationic intermediates of the Brookhart polymerization of alkenes, and to prove on‐line their catalytic activity through ion/molecule reactions. The technique is fast and sensitive, requires no sample preparation and manipulation, and is therefore suitable for the fast screening of catalyst/polymer growth by MS identification, with potential applications in areas such as new catalyst development, polymer chemistry, and product quality monitoring in manufacturing. Copyright © 2008 John Wiley & Sons, Ltd.
Mass spectrometric compatibility of Deep Purple and SYPRO Ruby total protein stains for high‐throughput proteomics using large‐format two‐dimensional gel electrophoresis
Authors: Nock Christina M. , Ball Malcolm S. , White Ian R. , Skehel J. Mark , Bill Louisa , Karuso Peter 
Published: February 2008

AbstractIn order to identify putative biomarkers from two‐dimensional (2D) gel electrophoresis it is necessary to use a visualization technique that is sensitive, has a large dynamic range and does not interfere with the identification of the protein. As mass spectrometry increases in sensitivity more pressure is placed on visualization techniques that facilitate proteomic workflows but do not interfere with downstream processing. Two stains reported to meet these requirements are SYPRO Ruby (Invitrogen) and Deep Purple (GE Healthcare). This study examined the compatibility of these stains with protein identification by selecting spots from replicate 2D gels of human plasma and subjecting these to protein identification using liquid chromatography/tandem mass spectrometry (LC/MS/MS). Using a test of two populations of proportions it was found that proteins were statistically more likely to be identified from gels stained with Deep Purple. Additionally, the identifications from Deep Purple stained gels are of higher quality because they are based on multiple peptides. Copyright © 2008 John Wiley & Sons, Ltd.
LMI optimization approach to robustH∞observer design and static output feedback stabilization for discrete‐time nonlinear uncertain systems
Authors: Abbaszadeh Masoud , Marquez Horacio J. 
Published: February 2008

AbstractA new approach for the design of robustH∞observers for a class of Lipschitz nonlinear systems with time‐varying uncertainties is proposed based on linear matrix inequalities (LMIs). The admissible Lipschitz constant of the system and the disturbance attenuation level are maximized simultaneously through convex multiobjective optimization. The resultingH∞observer guarantees asymptotic stability of the estimation error dynamics and is robust against nonlinear additive uncertainty and time‐varying parametric uncertainties. Explicit norm‐wise and element‐wise bounds on the tolerable nonlinear uncertainty are derived. Also, a new method for the robust output feedback stabilization withH∞performance for a class of uncertain nonlinear systems is proposed. Our solution is based on a noniterative LMI optimization and is less restrictive than the existing solutions. The bounds on the nonlinear uncertainty and multiobjective optimization obtained for the observer are also applicable to the proposed static output feedback stabilizing controller. Copyright © 2008 John Wiley & Sons, Ltd.
Investigation of the electrochemical behaviour and surface chemistry of a Ti‐13Nb‐13Zr alloy exposed in MEM cell culture media with and without the addition of H2O2
Authors: Baker M. A. , Assis S. L. , Grilli R. , Costa I. 
Published: February 2008

AbstractPromoting and understanding the formation of hydroxyapatite (HA) on biocompatible metals in the body is a very important topic of biomaterials research. In this paper, the formation of HA on a near‐β Ti‐13Nb‐13Zr alloy by immersion in minimal essential medium (MEM) with and without the addition of H2O2 has been studied using electrochemical methods, SEM and XPS. The Ti‐13Nb‐13Zr alloy exhibits passive behaviour over a wide potential range when immersed in MEM, and the passive film is composed of an inner barrier layer and an outer porous layer. Exposure for 72 h in the MEM solution results in the formation of a surface layer composed of an island‐like distribution of HA material and adsorbed amino acids. The addition of H2O2 to the MEM solution strongly promotes the formation of a thicker, continuous nanocomposite layer of HA and amino acids. For Ti alloys, the release of H2O2 in the anti‐inflammatory response appears to be an important beneficial process, as it serves to accelerate osseointegration. Copyright © 2008 John Wiley & Sons, Ltd.
Tantalum nitride thin film resistors by low temperature reactive sputtering for plastic electronics
Authors: Scandurra Antonino , Indelli Giuseppe Francesco , Pignataro Bruno , Di Marco Silvestra , Di Stefano Maria Ausilia , Ravesi Sebastiano , Pignataro Salvatore 
Published: February 2008

AbstractThis article describes the fabrication and characterisation of tantalum nitride (TaN) thin film for applications in plastic electronics. Thin films of comparable thickness (50–60 nm) have been deposited by RF‐magnetron‐reactive sputtering at low temperature (100 °C) and their structure and physical (electrical and mechanical) properties have been correlated by using sheet resistance, stress measurements, atomic force microscopy (AFM), XPS, and SIMS. Different film compositions have been obtained by varying the argon to nitrogen flow ratio in the sputtering chamber. XPS showed that 5:1, 2:1 and 1:1 Ar:N2 ratios gives Ta2 N, TaN and Ta3N5 phases, respectively. Sheet resistance revealed an increase in resistivity ongoing from the Ta2N phase to the Ta3N5 one. The electrical properties of these films are comparable to those obtained by high temperature deposition process already reported in literature. Furthermore, a roughness and grain size modulation of the above films can be obtained by applying an RF negative bias during deposition without affecting the electrical resistivity. Copyright © 2008 John Wiley & Sons, Ltd.
Analysis of the oil–water interface by XPS at low temperature
Authors: Genet M. J. , Cogels P. , Adriaensen Y. , Rouxhet P. G. 
Published: February 2008

AbstractA protocol was set up to achieve good control and monitoring of the XPS analysis of hydrated specimens, which involves the ability to freeze the sample before its introduction into the spectrometer, to maintain ice under UHV and to control ice sublimation. The methodology was applied successfully to a model system consisting of a drop of water deposited on a film of triolein containing traces of a phospholipid (dipalmitoyl phosphatidylcholine). Phosphorus and nitrogen, characteristic of the phospholipid, were demonstrated to be accumulated at the spot of the initial oil–water interface. The redistribution of the phospholipid after oil melting could be monitored in real time. The method is promising not only to study surface rearrangements on hydrated systems after water removal but also to get analytical information on gas–water interfaces and on interfaces between two liquids differing according to volatility. Copyright © 2008 John Wiley & Sons, Ltd.
The enigma of the silver blackening of the 13th century Notre‐Dame shrine of Huy (Belgium): a surface analysis approach
Authors: Crabbé Amandine , Vandendael Isabelle , Wouters Helena , Dewanckel Gilberte , Steenhaut Oscar , Terryn Herman 
Published: February 2008

AbstractThe purpose of this article is to re‐examine Theophilus' and Cellini's recipes, to understand what they were used for and to find out whether they could have been used for the Notre‐Dame shrine of Huy (Rheno‐Mosan art, 13th century).A historical sample (the statuette of St Jacques the Major of the Notre‐Dame shrine) was studied with X‐ray fluorescence (XRF) in order to determine the presence of iron at its surface. The preparation of model samples gave the opportunity to study Cellini's recipe better. These model samples were characterised with colorimetric analysis, scanning electron microscopy–energy dispersive X‐ray (SEM–EDX) analysis and AES. It is observed that applying Cellini's recipe results in a colour change, due to the presence of iron and oxygen at the surface of the samples. The presence of iron at the surface of both the model samples and the statuette of St Jacques is a good indication that the recipe may have been used on the statuettes of the Notre‐Dame shrine of the Collegiate of Huy. Moreover, it is shown that the iron is not influenced by the artificial ageing of the model samples. The possible use of Cellini's recipe for changing the colour of gilding is a very new point of view to consider middle‐age shrine. The practical implications for restoration are that it is important not to change the oxidation state of the iron and so the gilding colour. It is recommended to remove the black coating on the statuette's surface but without using techniques like, e.g. EDTA baths. Copyright © 2008 John Wiley & Sons, Ltd.
An analysis of eight 95 per cent confidence intervals for a ratio of Poisson parameters when events are rare
Authors: Barker Lawrence , Cadwell Betsy L. 
Published: February 2008

AbstractWe compared eight nominal 95 per cent confidence intervals for the ratio of two Poisson parameters, both assumed small, on their true coverage (the probability that the interval includes the ratio of Poisson parameters) and median width. The commonly used log‐linear interval, justified by asymptotic considerations, provided coverage and relatively narrow intervals, despite small numbers of arrivals. However, the uniform and scores intervals, defined in the text, come very close to providing coverage while providing substantially narrower intervals. These intervals might have practical applications. In a sensitivity analysis, none of the intervals maintained coverage for negative binomial data, indicating that distributional assumptions should be checked before taking our recommendations. Copyright © 2008 John Wiley & Sons, Ltd.
Chronic stress enhances methamphetamine‐induced extracellular glutamate and excitotoxicity in the rat striatum
Authors: Tata Despina A. , Yamamoto Bryan K. 
Published: February 2008

AbstractStriking parallels exist between the neurochemical and toxic effects of stress and methamphetamine. Despite these similarities, no studies have examined how stress may promote the toxic effects of methamphetamine (METH). The current study tested the hypothesis that chronic stress enhances METH toxicity by augmenting glutamate (GLU) release and excitotoxicity in response to METH administration. Adult male Sprague‐Dawley rats were exposed to 10 days of unpredictable stress and then received either saline or METH (7.5 mg/kg, i.p., once every 2 h × four injections). Prior exposure to unpredictable stress acutely enhanced the striatal extracellular GLU concentrations in response to METH, and eventually caused proteolysis of the cytoskeleton protein spectrin. Administration of the corticosterone synthesis inhibitor, metyrapone (25 mg/kg, i.p., prior to each stressor), during unpredictable stress attenuated the enhanced striatal GLU release in response to METH, blocked spectrin proteolysis, and attenuated METH‐associated toxicity measured by long‐term depletions in the dopamine and serotonin tissue content as well as depletions in dopamine and serotonin transporter immunoreactivity of the striatum. In summary, prior exposure to unpredictable stress enhances METH‐induced elevations of GLU in the striatum, resulting in long‐term excitotoxic damage and an augmentation of damage to dopamine and serotonin terminals. These studies provide a neurochemical basis for how stress contributes to the deleterious effects of METH abuse. Synapse 62:325–336, 2008. © 2008 Wiley‐Liss, Inc.
Localization of zinc in the outer retina of carp: A light‐ and electron‐microscopic study
Authors: Lee Shu‐Chen , Zhong Yong‐Mei , Li Rui‐Xi , Yu Zhang , Yang Xiong‐Li 
Published: February 2008

AbstractMany lines of evidence suggest that zinc may play an important neuromodulatory role in the central nervous system, including the retina. In this work, localization of zinc in the outer retina of carp was studied, using the silver amplification method, by light and electron microscopy. Reaction products (silver grains) were widely distributed throughout the retina, including photoreceptors, the outer and inner nuclear layers (ONL and INL), the ganglion cell layer (GCL), as well as in both outer and inner plexiform layers (OPL and IPL). Generally, staining for zinc was stronger in the outer retina than in the inner retina, and grains were aggregated with the greatest density in the OPL and the outer limiting membrane (OLM). Silver precipitates were also detected in the inner segments, axons, but not outer segments of photoreceptors. At the ultrastructural level, zinc was localized to myoid regions, mitochondria in the inner segments, internuclear space and nuclei of photoreceptors. In addition, silver grains were found in the terminals of photoreceptors, cone pedicles, and rod spherules, as well as in some processes in the OPL, which might be dendrites of horizontal cells. The presence of zinc in the terminals of photoreceptors suggests that zinc might be released from photoreceptor terminals and play modulatory roles in the outer retina. Synapse 62:352–357, 2008. © 2008 Wiley‐Liss, Inc.
Degradation and detoxification of cresols in synthetic and industrial wastewater by an indigenous strain of Pseudomonas putida in aerobic reactors
Authors: Gallego Alfredo , Gemini Virginia L. , Fortunato María S. , Dabas Paula , Rossi Susana L. , Gómez Carlos E. , Vescina Cristina , Planes Estela I. , Korol Sonia E. 
Published: February 2008

AbstractWe studied the degradation of mixtures of o‐cresol, m‐cresol, and p‐cresol, by Pseudomonas putida isolated from natural sources, and the application of this degradation to the depuration and detoxification of synthetic and industrial wastewater. Biodegradation assays were performed in batch and continuous‐flow fixed‐bed aerobic reactors. Biodegradation was evaluated by cresol determination using micellar electrokinetic capillary chromatography, UV spectrophotometry, and chemical oxygen demand (COD). Mineralization of cresols was assessed by gas chromatography performed both at the end of the batch process and in the continuous flow reactor effluent. Microbial growth was measured by the plate count method. Scanning electronic microscopy was employed to observe bacterial cells adsorbed on polyvinyl chloride cylinders in the reactor. Detoxification was evaluated by Vibrio fischeri, Pseudokirchneriella subcapitata, and Daphnia magna toxicity tests. Results obtained show that under batch conditions the strain grew exponentially with 100, 200, and 300 mg/L of each of the isomers in synthetic minimal medium within 48 h; in industrial wastewater with 540 mg/L of cresols similar results were obtained. Removal of cresols and COD was higher than 99.9% and 95.0%, respectively. When assays were performed in continuous flow reactor in synthetic wastewater under operating conditions a removal of total cresols and COD of 99.9% and 96.4%, respectively, was achieved. Results of capillary electrophoresis may suggest a concurrent isomers utilization and simultaneous growth on the substrates. Toxicity was neither detected at the end of the batch process nor in the continuous flow reactor effluent. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Effects of various carbon and nitrogen sources on fungal lipid production
Authors: Farag R. S. , Khalil F. A. , Salem H. , Ali L. H. M. 
Published: February 2008

AbstractThe efficiency of lipid production byTolyposporium ehrenbergii andSpacelotheca reiliana (family Ustilaginaceae) cultivated on a fat‐free medium was evaluated. The fungi were artificially cultured on media containing various monoor disaccharides and urea or peptone as basic sources for carbon and nitrogen, respectively. Some natural and industrial byproducts (glycerol, glucose syrup, potato hydrolysate and molasses hydrolysate) were also used as principal carbon sources for fungal growth. Media containing fructose/peptone or glucose/peptone were the most efficient for fungal fat production during one week of incubation. After a two‐week incubation period, highest phospholipid concentrations were found in S.reiliana andT. ehrenbergii mycelia obtained from media containing molasses hydrolysate/peptone and glycerol/urea, respectively. Fatty acid analysis of the fungal growth indicated the presence of a wide range of fatty acids, i.e., odd‐and even‐carbon numbered acids, both saturated and unsaturated. The results demon‐strated that the variability in the fatty acid composition largely depends on the type of sugar and nitrogen sources and the age of the culture.
Synthesis and properties of fatty imidazolines and their N‐(2‐aminoethyl) derivatives
Authors: Bistline Raymond G. , Hampson James W. , LinField Warner M. 
Published: February 2008

AbstractCationic high molecular weight surfactants hold promise as water repellents for soil for water harvesting. Specifically, the products of the reaction of 2 moles of fatty acids with 1 mole of diethylenetria‐mine were investigated. Optimum conditions for the formation of imidazolines as well as the open‐chain N‐(2‐aminoethyl) derivatives, i.e., the diamides, were determined. Saturated fatty acids, pelargonic through behenic, oleic acid, elaidic acid as well as tallow, tallow fatty acids, and hydrogenated tallow fatty acids, were converted in 6 hr at 150 C to form the diamides. The fatty imidazolines were synthesized by cyclizing the diamides at 150 C for 2 hr under reduced pressure in a 92% yield. The crude imidazolines were purified by crystallization. The fatty imidazolines were readily hydrolyzed at the C=N bond of the imidazoline ring with water or dilute alcohol. The resulting diamides, RCON(CH2 CH2 NH2)CH2 CH2 NHCOR, were also purified by crystallization. Water repellency of these com‐pounds was evaluated by contact angle measurements and percola‐tion tests. The surface properties of these series of compounds are determined by four parameters. The open‐chain diamides are more hydrophobic than the analogous imidazolines, and hydrophobicity increases with increasing molecular weight of derivatives of saturated fatty acids. Oleic acid derivatives are far more hydrophilic than the saturated acid derivatives or the analogous elaidic acid derivatives. The latter are more hydrophilic than stearic derivatives.
Simultaneous detection of aflatoxin b1 and ochratoxin a in olive oil
Authors: Letutour B. , Tantaoui‐Elaraki A. , Ihlal L. 
Published: February 2008

AbstractA screening method has been developed for simultaneous determination of aflatoxin B1 and ochratoxin A in olive oil. The technique includes extraction of both mycotoxins with aqueous methanol, clean‐up using lead acetate, partitioning in chloroform, and thin layer chromatography. The detection limits achieved are, respectively: 4 μg aflatoxin B1 and 40 μg ochratoxin A/kg. 60 samples of crude farm olive oil were analyzed using this method: three of them contained traces of ochratoxin A while none was contaminated with aflatoxin B1.
Iso‐solid diagrams of fat blends from thermal analysis data
Authors: Lambelet P. , Raemy A. 
Published: February 2008

AbstractThe use of spline interpolation between solid fat index (SFI) values obtained from calorimetric experiments to determine iso‐solid data is described. Computer programs control both the sampling of the data from the calorimeter and the calculation of iso‐solid values. This approach allows us to plot iso‐solid diagrams fully automa‐tically. Examples for cocoa butter/milk fat mixtures are given.
Analysis of cationic and amphoteric surfactants: III. Structural analysis of imidazolinium cationic surfactants
Authors: Takano Satoshi , Tsuji Kazuro 
Published: February 2008

AbstractDetermination of the homologous distribution of imidazolinium cationic surfactants and their structural analysis have been inves‐tigated. These surfactants were hydrolyzed under aqueous alkaline media, followed by acid hydrolysis to afford fatty acids and poly‐amines. The resulting fatty acids were esterified with methanol, and then analyzed by gas chromatography (GC) in order to determine their homologous distribution. The obtained distribution agrees well with that of original fatty acid. Therefore, this method should be applicable to the determination of the homologous distribution of imidazolinium surfactants. The resulting polyamines were acetylated with acetic anhydride in the presence of pyridine. These acetates were analyzed by GC and isolated by preparative thin layer chroma‐tography on silica gel. The structures of these isolates were identi‐fied by means of 1 H‐NMR and 1R spectrometry. These structural analyses demonstrated that quaternization of an imidazoline ring selectively occurred at the nitrogen at the 3‐position of an imida‐zoline ring, which was the kinetically favored position in terms of the steric hinderence and the stability of product.
Ricinoleic Acid in Common Vegetable Oils and Oil Seeds
Authors: Yamamoto Kouhei , Kinoshita Akemi , Shibahara Akira 
Published: February 2008

AbstractAn original gas chromatography/mass spectrometry method for quantifying trace amounts of ricinoleic acid (12‐hydroxy‐cis‐9‐octadecenoic acid) is detailed. Data are presented on trace amounts of ricinoleic acid found in several common vegetable oils and oils extracted from common oil seeds: e.g., ca. 30 ppm in commercial olive oil was the lowest amount; and ca. 2,690 ppm in oil extracted from cottonseeds was the highest amount.