bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functionalized nanoparticles for liquid atmospheric pressure matrix‐assisted laser desorption/ionization peptide analysis
Authors: Turney Kevin , Drake Timothy J. , Smith Joshua E. , Tan Weihong , Harrison W. W. 
Published: September 2004

AbstractNanoparticles for the extraction of peptides and subsequent analysis using atmospheric pressure matrix‐assisted laser desorption/ionization (APMALDI) have been evaluated. The atmospheric pressure source allows for particles to be directly introduced in the liquid matrix, minimizing sample loss and analysis time. Described in this work are two sample preparation procedures for liquid APMALDI analysis: a C18 functionalized silica nanoparticle for hydrophobic extractions, and an aptamer functionalized magnetite core nanoparticle for rapid, affinity extractions. The C18 particles provide a non‐selective support for rapid profiling applications, while the aptamer particles are directed towards reducing the complexity in biological samples. The aptamer functionalized particles provide a more selective analyte–nanoparticle interaction whereby the tertiary structure of the analyte becomes more critical to the extraction. In both cases, the liquid APMALDI matrix provides a support for ionization, and acts as the releasing agent for the analyte–particle interaction. Additionally, analyte enrichment was possible due to the large surface‐to‐volume ratio of the particles. The experiments conducted with functionalized nanoparticles, in an atmospheric pressure liquid matrix, present a basis for further methodologies and utilities of silica nanoparticles to be developed. Copyright © 2004 John Wiley & Sons, Ltd.
Efficient in‐gel digestion procedure using 5‐cyclohexyl‐1‐pentyl‐β‐D‐maltoside as an additive for gel‐based membrane proteomics
Authors: Katayama Hiroyuki , Tabata Tsuyoshi , Ishihama Yasushi , Sato Toshitaka , Oda Yoshiya , Nagasu Takeshi 
Published: September 2004

AbstractA cycloalkyl aliphatic saccharide, 5‐cyclohexyl‐1‐pentyl‐β‐D‐maltoside (CYMAL‐5), was evaluated as a novel additive in a high‐throughput in‐gel protein digestion system using 96‐well plates. Addition of 0.1% CYMAL‐5 (final concentration) during trypsin treatment was compatible with both matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS) analysis, and gave a better digestion efficiency than n‐octylglucoside, which we previously reported. In‐gel reduction and alkylation of Cys residues under denaturing conditions also improved the sequence coverage of peptides. In‐gel tryptic digestion with the optimum combination of 0.5 mm thick gels, negative staining, alkylation under denaturing conditions (6 M guanidine hydrochloride), and digestion in the presence of CYMAL‐5, gave excellent performance especially for membrane protein analysis, where recovery of hydrophobic peptides was markedly enhanced. The new protocol is simple and convenient, and should be widely applicable to gel‐based proteomics. Copyright © 2004 John Wiley & Sons, Ltd.
Multiphoton dissociation/ionization of CHCl3 and CFCl3 at 355 nm: an experimental and theoretical study
Authors: Sharma P. , Vatsa R. K. , Maity D. K. , Kulshreshtha S. K. 
Published: September 2004

AbstractNonresonant laser‐induced multiphoton dissociation/ionization studies have been conducted for trichloromethane (CHCl3) and trichlorofluoromethane (CFCl3) at 355 nm, using time‐of‐flight mass spectrometry (TOFMS). The molecular ion signal was found to be missing for both these compounds, and very similar fragmentation patterns were observed. Ab initio molecular electronic structure calculations were performed to help understand the fragmentation pattern of these molecules in the laser field. The energetics of different dissociation channels in the ground states of [CHCl3]+., [CHCl2]+, [CFCl3]+. and [CFCl2]+, as well as neutral CHCl3, CHCl, CFCl3 and CFCl systems, were calculated. On comparing theoretical results with experimentally observed ion signals and their relative abundances in TOFMS, it is inferred that these molecules undergo sequential Cl atom elimination followed by photoionization of the fragments. The absence of [CFCl]+ has been interpreted on the basis of resonant Ã state‐mediated two‐photon absorption by CFCl, and the subsequent prompt photodissociation processes occurring for this state. Copyright © 2004 John Wiley & Sons, Ltd.
Applications of a travelling wave‐based radio‐frequency‐only stacked ring ion guide
Authors: Giles Kevin , Pringle Steven D. , Worthington Kenneth R. , Little David , Wildgoose Jason L. , Bateman Robert H. 
Published: September 2004

AbstractThe use of radio‐frequency (RF)‐only ion guides for efficient transport of ions through regions of a mass spectrometer where the background gas pressure is relatively high is widespread in present instrumentation. Whilst multiple collisions between ions and the background gas can be beneficial, for example in inducing fragmentation and/or decreasing the spread in ion energies, the resultant reduction of ion axial velocity can be detrimental in modes of operation where a rapidly changing influx of ions to the gas‐filled ion guide needs to be reproduced at the exit. In general, the RF‐only ion guides presently in use are based on multipole rod sets. Here we report investigations into a new mode of ion propulsion within an RF ion guide based on a stack of ring electrodes. Ion propulsion is produced by superimposing a voltage pulse on the confining RF of an electrode and then moving the pulse to an adjacent electrode and so on along the guide to provide a travelling voltage wave on which the ions can surf. Through appropriate choice of the travelling wave pulse height, velocity and gas pressure it will be shown that the stacked ring ion guide with the travelling wave is effective as a collision cell in a tandem mass spectrometer where fast mass scanning or switching is required, as an ion mobility separator at pressures around 0.2 mbar, as an ion delivery device for enhancement of duty cycle on an orthogonal acceleration time‐of‐flight (oa‐TOF) mass analyser, and as an ion fragmentation device at higher wave velocities. Copyright © 2004 John Wiley & Sons, Ltd.
Trace determination of anthracyclines in urine: a new high‐performance liquid chromatography/tandem mass spectrometry method for assessing exposure of hospital personnel
Authors: Sottani Cristina , Tranfo Giovanna , Bettinelli Maurizio , Faranda Paolo , Spagnoli Mariangela , Minoia Claudio 
Published: September 2004

AbstractHealth‐care workers handling antineoplastic agents may be exposed to extremely low doses of these drugs. Very sensitive and specific analytical methods are therefore needed for biological monitoring. The aim of this study was to develop and validate a method for trace level determination of doxorubicin, epirubicin, daunorubicin and idarubicin in human urine, using epi‐daunorubicin as an internal standard. Solid‐phase extraction (SPE) was used for sample preparation. Urine samples were loaded onto Bond Elut C18 cartridges. The analytes were eluted in methylene chloride/2‐propanol (1:1, v/v) and then evaporated to dryness. The residue was reconstituted with the mobile phase prior to high‐performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) analysis. Quantitation of each analyte was performed using the multiple reaction monitoring (MRM) method. The urine assay was linear over the range 0.1–2.0 μg/L, with a lower limit of quantification (LLOQ) of 0.10 μg/L for doxorubicin and epirubicin, and 0.03 μg/L for daunorubicin and idarubicin. The respective limits of detection (LODs) were 0.04 and 0.01 μg/L. The precision and accuracy of the assay were determined on three different days. The within‐series precision was found to be always less than 13.9% for all the analytes. The overall precision expressed as relative standard deviation (RSD) was always less than 10.6%. The recovery of anthracyclines was assessed at two concentrations of the range tested (0.1 and 2.0 μg/L) and it ranged from 87.7% (daunorubicin) to 102.0% (doxorubicin) and from 79.1% (daunorubicin) to 90.7% (idarubicin) for the lower and the higher level, respectively, with a RSD always less than 9.1%. The uncertainty of the present assay was also evaluated and the combined uncertainty was always less than 20% over all the days of the validation study. This is the first method that makes use of LC/MS/MS for the biological monitoring of occupational exposure to anthracyclines. Copyright © 2004 John Wiley & Sons, Ltd.
A distributed fuzzy logic controller for an autonomous vehicle
Authors: Hodge Neil Eugene , Shi Linda Zhixia , Trabia Mohamed B. 
Published: September 2004

AbstractAutonomous vehicles can be used in a variety of applications such as hazardous environments or intelligent highway systems. Fuzzy logic is an appropriate choice for this application as it can describe human behavior well. This paper proposes two fuzzy logic controllers for the steering and the velocity control of an autonomous vehicle. The two controllers are divided into separate modules to mimic the way humans think while driving. The steering controller is divided into four modules; one module drives the vehicle toward the target while another module avoids collision with obstacles. A third module drives the vehicle through mazes. The fourth module adjusts the final orientation of the target. The velocity controller is divided into three modules; the first module speeds up the vehicle to reach the target and slows it down as it moves toward the target. The second module controls the velocity in the neighborhood of obstacles. A third module controls the velocity of the vehicle as it turns sharp corners. A method for automatic tuning of the first module of the velocity controller is proposed to stabilize the velocity of the vehicle as it approaches the target. Two examples to demonstrate the interaction among the seven control modules are included. Results of the simulation are compared with those in the literature. © 2004 Wiley Periodicals, Inc.
On using flexure‐hinge five‐bar linkages to develop novel walking mechanisms and small‐scale grippers for microrobots
Authors: Wang Guo‐bao , Wang Shi‐gang , Xu Wei 
Published: September 2004

AbstractThis paper presents the micromotion analysis of five‐bar linkages and demonstrates the approximate linearity of motion transmission of five‐bar mechanisms within a micromotion range. A novel walking mechanism used for a microrobot and a small‐scale gripper with a high transmission ratio are introduced, based on the flexure‐hinge five‐bar mechanism analysis. Results of numerical simulation show the validity of design and analysis on the introduced mechanisms and the feasibility of corresponding thoughts. The presented micromotion‐based robot mechanisms are devoid of friction and fitting errors, and particularly suitable for microrobot applications. © 2004 Wiley Periodicals, Inc.
Characterization of siloxane films on titanium substrate derived from three aminosilanes
Authors: Matinlinna J. P. , Areva S. , Lassila L. V. J. , Vallittu P. K. 
Published: September 2004

AbstractThe aim of this investigation was to study the siloxane, SiOSi, film formation on Ti substrate by using mono‐, bis‐ and tris‐aminosilanes. The ultimate goal was to obtain a smooth, well‐organized and stable siloxane film with suitable surface energy. Such films are expected to perform well in adhering resins to dental metal alloys when the films contain reactive functional groups. Aminosilanes were prepared as 0.5 vol.% solutions in dilute ethanol (50 vol.% ethanol in deionized water), with their natural pH of ∼ 9. The substrates were silanized in two ways: silane was allowed to react at room temperature or was cured for 1 h at 110°C. The surface characterization was carried out by reflectance–absorbance Fourier transform infrared spectroscopy (RA‐FTIR), x‐ray photoelectron spectroscopy (XPS), contact angle measurement and atomic force microscopy (AFM). Siloxane film thickness measurements were not made. According to spectral analysis, all silanes indicated covalent bond formation with titanium. SiOTi and SiOSi bonds were clearly seen in the spectra, suggesting that chemical retention had taken place. After curing at elevated temperature, the spectral bands seemed to be stronger than those on samples cured at room temperature. Curing of hydrolyzed silanes at elevated temperature seemed to enhance the siloxane layer formation, derived from aminosilanes, on the Ti substrate. This might have an influence on the hydrolytic stability of organosilane‐promoted adhesion between Ti and dental resins. Copyright © 2004 John Wiley & Sons, Ltd.
Friction coefficient mapping using the atomic force microscope
Authors: Breakspear S. , Smith J. R. , Nevell T. G. , Tsibouklis J. 
Published: September 2004

AbstractA friction coefficient map of the surface of an immiscible polymer blend has been constructed using data obtained with the atomic force microscope. Spatially resolved friction coefficients, obtained from gradients of linear plots of frictional force versus applied load, were used to construct the map, with corresponding frictional forces being derived from lateral force data and the lateral spring constant. Values of the friction coefficient were confirmed using an Si3N4/Si3N4 couple, for which literature values were available. Excellent agreement with the literature was observed through the use of this method. Copyright © 2004 John Wiley & Sons, Ltd.
Electrochromic nickel oxide films made by reactive r.f. sputtering from different targets
Authors: Ottaviano L. , Pennisi A. , Simone F. 
Published: September 2004

AbstractWe describe the preparation and optical–electrical characterization of thin electrochromic layers based on nickel oxide (NiOx). These layers were deposited by reactive radiofrequency (r.f.) sputtering from nickel or nickel oxide targets, maintaining the r.f. power and varying the oxygen flow in a gas mixture of Ar and O2 from 5% up to 30%. The Ni/O ratio in the deposited thin films was determined by Rutherford backscattering spectroscopy (RBS) and the microstructure was investigated by x‐ray diffraction. The deposition rate was found to be strongly dependent on the type of target used. The electrochromic behaviour in aqueous alkaline electrolyte (0.1 N KOH solution) was investigated by electrochemical cyclization. Samples deposited by the NiO target exhibited the lowest N/O ratio (0.5) and the highest value of intercalated charge (∼4.9 × 10−2 mC cm−2 nm−1). Among the same samples the highest value of the intercalated charge was found for those deposited at low oxygen flow, but these samples exhibit the smallest reversible changes in optical absorption in the wavelength range 330–1200 nm.Samples deposited by the nickel target do not exhibit significant variations in the value of the exchanged charge; the measured Ni/O ratio indicates a stoichiometry closer to NiO. We also observed the switching behaviour by analysing the films in cyclic time mode at a fixed wavelength. The commutation response time is estimated by measurement under the application of a step waveform potential. Copyright © 2004 John Wiley & Sons, Ltd.
Scanning force microscopy study of the morphology of spin‐cast molecular‐imprinted nylon thin films
Authors: Maier Petra , Werner‐Allen Jonathan , Gibson Ursula J. , Richter Asta , BelBruno Joseph J. 
Published: September 2004

AbstractThe morphology of thin, selectively imprinted films of Nylon‐6 was investigated by scanning force microscopy. Four amino acids were used as template molecules in the spin‐cast films. Film thickness ranged from 2 µm to 500 nm, depending on the nylon and template concentration in the casting solution. The thin‐film properties, including the presence of nanometer‐ to micrometer‐sized pores, are clearly associated with the imprinting process. The larger features observed by scanning force microscopy are attributed to amino acid clustering during the casting process. Copyright © 2004 John Wiley & Sons, Ltd.
Some Physical and Chemical Properties of Starch Isolates of Cassava Genotypes
Authors: Charles Albert L. , Chang Yung‐Ho , Ko Wen‐Ching , Sriroth Klanarong , Huang Tzou‐Chi 
Published: September 2004

AbstractCassava starches (Manihot esculenta Crantz) were prepared from tubers of Kaesetsart 50 (KU50), Rayong 5, Hanatee and KMUL 36‐YOO2 (YOO2) and their physicochemical properties studied using the Rapid Visco Analyser (RVA), differential scanning calorimetry (DSC) and rheometry. Amylose content was determined by iodine potentiometric titration (IPT) and gel permeation chromatography (GPC). Starch contents of the tubers varied from 34.2 to 35.1% and protein and fiber contents in the starches varied from 0.8 to 1.1% and 0.6 to 0.8%, respectively. The cassava starches contained 0.06–0.12% lipid and 0.7% to 0.9% ash. Amylose content determined by IPT (15.9 to 22.4%) had higher positive correlation with peak viscosity, breakdown and gel consistencies (R2 = 0.835, 0.772, 0.859), respectively, whereas GPC (18.1 to 25.3%) showed high correlation with setback (R2 = 0.923) and ΔH (R2 = 0.579). The onset gelatinization temperatures varied from 59.7–64.4°C, and KU50 exhibited highest ΔH of 13.7 J/g. Hanatee and YOO2 formed clear gels with higher peak viscosities, setback and gel consistency viscosities attributed to their higher amylose contents. Retrogradation of KU50 and Rayong 5 tended to be more severe on cooling and formed opaque gels, showing higher resistance to shearing, properties attributed to recrystallized amylopectin fractions.
Grafting of Poly(Methacrylic Acid) on Starch and Poly(Vinyl Alcohol)
Authors: Beliakova Margarita K. , Aly Amal A. , Abdel‐Mohdy Fikry A. 
Published: September 2004

AbstractGrafting of methacrylic acid (MAA) on starch, poly(vinyl alcohol) (PVA), and a mixture of starch and PVA, using a potassium persulfate/ sodium thiosulfate redox initiation system was carried out. Polymerization was studied with respect to graft yield, homopolymer formation and total conversion. These polymerization criteria were found to depend largely on the concentration of both MAA and initiators, duration and method of polymerization.The results reveal a number of interesting points which reflect the impact of the condition of the treatment. The main product of the polymerization reaction [poly(MAA)‐starch/PVA graft copolymer] was formed and precipitated during polymerization and can be easily separated by filtration as pure product.Application of these copolymers to cotton fabric was also carried out to evaluate the suitability of such modified products as sizing agents.
Xenobiotic substances such as PCB mixtures (Aroclor 1254) and TBT can influence swimming behavior and biotransformation activity (GST) of carp (Cyprinus carpio)
Authors: Schmidt Katja , Steinberg Christian E. W. , Pflugmacher Stephan , Staaks Georg B. O. 
Published: September 2004

AbstractDifferent groups of carp were treated with polychlorinated biphenyl (PCB) or tributyltin (TBT), and possible effects of the chemicals on the swimming behavior of the carp were examined using the BehavioQuant system. By evaluating quantitative behavioral parameters of the animals, it became evident that exposure to high concentrations of chemicals (organotin, 7 μg L−1, or polychlorinated biphenyl, 22 μg L−1) severely affected the carp, causing a significant change in their swimming speed. TBT stress led to a rapid decrease in mean swimming activity. A decrease in the preferred swimming depth was observed in TBT‐ and PCB‐exposed fish. Animals exposed to PCB reduced their mean daily activity and increased their mean swimming speed in the nighttime during the second week of exposure. Therefore, our findings imply that the fish were adapted to cope with the chemicals after the second week of exposure. Furthermore, our results showed that low concentrations (TBT, 0.3 and 2 μg L−1, or PCB, 14 μg L−1) did not significantly alter any quantified parameters of swimming behavior. In addition, the direct effects of chemicals on enzyme activity (GST) were determined. Measurement of soluble glutathione‐S‐transferase activity of fish liver or gills showed a significant elevation after exposure to PCB (0.1 or 22 μg L−1) or TBT (0.8 or 7 μg L−1). We had to conclude that the two different end points tested generally are useful as biomarkers of exposure and for investigations of energy resources in organisms under the influence of toxic stress. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 460–470, 2004.
Assessing cytotoxicity of photosensitized transformation products of 2,4,6‐trinitrotoluene (TNT) and atrazine with freshwater microbial assemblages
Authors: Zeng Kui , Hwang Huey‐Min , Zhang Yi , Cook Sean 
Published: September 2004

AbstractIn this study of riboflavin‐sensitized photolysis of 2,4,6‐trinitrotoluene (TNT), the final photoproducts were found to include 2‐amino‐4,6‐dinitrotoluene, 4‐amino‐2,6‐dinitrotoluene, and 3,5‐dinitroaniline. After exposure to TNT (10 mg/L) for 90 min, in a river water sample there was inhibition of the viability count of heterotrophic bacterial assemblages by 28.3% and 24.3% and of bacterial heterotrophic mineralization of glucose by 99.5% and 93.6% relative to the light control and dark control groups, respectively. After exposure separately to 10 mg/L 2‐amino‐4,6‐dinitrotoluene, 4‐amino‐2,6‐dinitrotoluene, or 3,5‐dinitroaniline, the viability count of heterotrophic bacterial assemblages was enhanced by 30.0%, 98.2%, and 148.7%, respectively, relative to the TNT group in light and by 12.2%, 40.2%, and 36.5%, respectively, relative to TNT group in dark. After exposure to the same aforementioned test chemicals, heterotrophic activity of bacterial assemblages was inhibited by 75.7%, 72.4%, and 56.0%, respectively, relative to light control group, and there were no significant changes in the dark. A similar study was conducted with atrazine (10 mg/L). The main products of atrazine riboflavin–sensitized phototransformation include desethylatrazine (DEA) and desisopropylatrazine (DIA). It was found that DEA and DIA did not inhibit microbial heterotrophic activity. However, after 72 h the viable count was enhanced by 52.8% and 63.3% in the DEA and DIA exposure groups, respectively, in comparison to the control. These results suggested that photosensitized transformation decreased TNT and atrazine cytotoxicity to microbial assemblages in the natural water. Photoproducts of atrazine–DEA and –DIA, and of TNT could become growth substrates for bacterial assemblages in natural water. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 490–496, 2004.
Circulating immune complexes as indicators of environmental contamination
Authors: Ramanaviciene A. , Acaite J. , Ramanavicius A. 
Published: September 2004

AbstractThe aim of this study was to examine the effect of environmental contamination on the concentration of circulating immune complexes (CIC) in bovine blood. We determined that in a conventionally ecologically clear district, the CIC concentration in healthy bovine blood serum was within the limits of 0.18–0.52 mg/mL, (mean = 0.31 mg/mL, V = 30.14%). In a conventionally ecologically contaminated district, the CIC concentration in healthy bovine blood serum was detected within the limits of 0.48–0.99 mg/mL (mean = 0.65 mg/mL, V = 17.97%; P < 0.05). The CIC concentration in serum of bovine leukemia virus (BLV)–infected bovines from different districts was within the limits of 0.29–1.76 mg/mL (mean = 0.81 mg/mL, V = 36.67%; P < 0.05). According to these preliminary results of the investigation, it may be supposed that the increased concentration of CIC is closely related to the environmental contamination. Therefore, studies of CIC concentration in healthy mammals are of great importance for the monitoring of anthropogenic factors and can be exploited as an indicator of environmental contamination. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 505–509, 2004.