bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemically assisted Fenton reaction: reaction of hydroxyl radicals with xenobiotics followed by on‐line analysis with high‐performance liquid chromatography/tandem mass spectrometry
Authors: Jurva Ulrik , Wikström Håkan V. , Bruins Andries P. 
Published: October 2002

AbstractOxygen radicals are generated in vivo by various processes, often as toxic intermediates in different metabolic transformations, and have been shown to play an important role for a large number of diseases. In this article we introduce an electrochemical flow‐through system that allows generation of hydroxyl radicals for reaction with xenobiotics and subsequent detection of the oxidation products on‐line with high‐performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS). The system is based on the Fenton reaction and is predominantly aimed at the generation of hydroxyl radicals; however, by minor variations to the system, a broad range of other radicals can be produced. Optimization of the system was performed with the radical scavenger 5,5‐dimethyl‐1‐pyrroline‐N‐oxide (DMPO). Under the same physical conditions, one injection through the electrochemical cell gave a higher yield of the oxidation product N‐hydroxy‐5,5‐dimethylpyrrolidin‐2‐one than what was attained after 60 min with a chemical Fenton system catalyzed by ascorbic acid. Since the iron is added as Fe3+, the initial mixture is ‘inactive’ until it reaches the electrochemical cell. This makes it very suitable for on‐line analysis of the generated compounds, since the whole reaction mixture, including substrate, can be kept in a vial in an autosampler. The system described provides a useful tool for investigation of new radical scavengers and antioxidants. Since the hydroxyl radical adds readily to unsaturated π‐systems, the technique is also suitable for on‐line generation and characterization of potential drug metabolites resulting from hydroxylation of double bonds and aromatic systems. Copyright © 2002 John Wiley & Sons, Ltd.
Quantitative evaluation of improvement ratio of image S/N in the NMR phase‐scrambled Fourier imaging technique
Authors: Kanzaki Nobuhiro , Ito Satoshi , Kamimura Yoshitsugu , Yamada Yoshifumi 
Published: October 2002

AbstractA phase‐scrambled Fourier transform imaging technique with a signal description algorithm similar to a Fresnel transform algorithm, which can be implemented by adding some changes to a conventional MRI system, can reduce noise in the image area without degrading resolution and can improve the S/N ratio of an image, even if the noise properties are unknown. This study presents two image S/N‐improvement methods in the phase‐scrambled Fourier imaging technique and quantitatively compares the extent of improvement of the image S/N ratio of the two methods by computer simulations. The results show that both methods 1 and 2 improve the image S/N ratio by a factor of about 1.3 at the maximum without degrading resolution or creating artifacts. In addition, applying the improvement methods to NMR signals collected by the phase‐scrambled Fourier transform imaging technique using the prototype MRI system that we have constructed confirms the same extent of improvement in the image S/N ratio as in the simulation results. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(12): 27–37, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10209
Moving object extraction using background difference and region growing with a spatiotemporal watershed algorithm
Authors: Sakaida Shinichi , Naemura Masahide , Kanatsugu Yasuaki 
Published: October 2002

AbstractIn this paper, we describe a new method for moving object extraction based on a background image subtraction method to be applied to an object‐based picture coding system. Since this method requires a background image, we have to represent the background from a moving picture that has been shot already. We propose a new method in which the background image is reproduced by a temporal histogram of each pixel in the picture and a watershed algorithm is employed for region growing to acquire precise edge detection of the moving objects. Furthermore, a spatiotemporal watershed algorithm is introduced in order to prevent judder of the extracted objects. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(12): 11–26, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10237
Deformation and cutting algorithm of an organ model used for a laparoscopic surgery simulator
Authors: Tanaka Toshiyuki , Ito Hiroaki , Miyashita Teruo 
Published: October 2002

AbstractWith the recent development of endoscopic instruments, laparoscopic surgery has come into widespread use. Compared to traditional open abdominal surgery, the method offers a reduction of the physical burden on the patient, the in‐hospital period, and the recovery period. On the other hand, more technical training is required compared to open surgery, since the surgery is conducted by observing a two‐dimensional image obtained by lapar‐oscopy. Many simulators for training have been developed in various research institutions. Most of these, however, require expensive high‐performance hardware, and there is a need for a low‐cost PC‐based virtual laparoscopic surgery simulator. The important issues in constructing such a simulator are a forceps input device and an organ model representation which can be deformed or cut. This paper reports both a forceps input device and an organ model which can be deformed and cut. The organ model consists of a mass‐spring model. In the deformation algorithm, an equation for force‐displacement balance is used. When the forceps contacts an object, mismatching of the model deformation is eliminated by fine segmentation of the area surrounding the point of contact. When an object is to be cut, the fine segmentation area surrounding the area of contact with the forceps is enlarged with the progress of the incision area, maintaining the continuity of the process. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(12): 1–10, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10247
Parallel algorithms for selection on the BSP and BSP* models
Authors: Ishimizu Takashi , Fujiwara Akihiro , Inoue Michiko , Masuzawa Toshimitsu , Fujiwara Hideo 
Published: October 2002

AbstractIn this paper, we propose parallel algorithms to solve the selection problem on the Bulk‐Synchronous Parallel (BSP) model and the BSP* model. The BSP and BSP* models are recently proposed parallel computation models. They can represent the communication cost, a vital element in the latest parallel computations, in terms of the parameters of the synchronization period L, the reciprocal g of the communication network bandwidth, and the packet size it B. In this paper, we propose a parallel algorithm having an internal computation time O[(n/p) + dlogploglogn + L(logploglogn)/(logd)] and a communication time O[g(n/p) + (gd + L)(logploglogn)/(logd)], on the BSP model, and a parallel algorithm having an internal computation time O[(n/p) + dlogploglogn + L(logploglogn)/(logd)] and a communication time O[g(n/(pB)) + (n/p)1/7(logp)6/7) + (gd + L)(logploglogn)/(logd)] on the BSP* model for any integer d(1 ≤ d ≤ logn) to solve the problem of selecting n data with p processors. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(12): 97–107, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.1170
XPS analysis of sol–gel‐generated mixed‐oxide layers for biomedical application
Authors: Schenk‐Meuser K. , Velten D. , Eisenbarth E. , Biehl V. , Duschner H. , Breme J. 
Published: October 2002

AbstractThe excellent biocompatibility of titanium and its alloys is associated with the properties of their dense TiO2 layer on the surface. The adsorption of proteins of the body fluid to implant surfaces depends on the properties of the surface oxide layer, especially the electronic structure. Therefore, tailoring of the oxide layer is a method for influencing protein adsorption. In this study, titanium platelets are coated by the sol–gel process with mixed oxides containing the biocompatible elements Ti, Nb, Zr and Ta. In order to verify the composition of the produced oxide layer, which can differ from the adjusted precursor composition in the sol because of different reactivities of the precursors, the layers were analysed with x‐ray photoelectron spectroscopy by carrying out sputter profiles. It was proved that the composition of a mixed‐oxide layer prepared by the sol–gel process can be tailored by the use of mixed precursors. Copyright © 2002 John Wiley & Sons, Ltd.
Contribution of surface analytical techniques for the microchemical study of archaeological artefacts
Authors: Ingo G. M. , Angelini E. , Bultrini G. , De Caro T. , Pandolfi L. , Mezzi A. 
Published: October 2002

AbstractSince the 18th century many analytical methods have been used to identify the chemical composition of archaeological artefacts, the provenance of the raw materials and the technical aspects of the manufacturing process. These techniques generally probe the bulk chemical and structural features of the objects and overlook surface characteristics often essential for understanding the manufacturing techniques and the ageing processes. This work describes the contribution of x‐ray photoelectron spectroscopy (XPS) combined with bulk analytical techniques such as scanning electron microscopy + energy − dispersive spectrometry (SEM + EDS), inductively coupled plasma mass spectrometry (ICPMS) and x‐ray diffraction (XRD) by discussing the origin of the embrittlement of some selected series of silver Republican Roman coins and the study of the microchemical nature of black and coral red glosses on Attic figured vases. The results show that XPS, if allowance is made for contamination or unrepresentative or non‐homogeneous samples, complements the existing bulk analytical techniques and can provide detailed information about the surface chemical nature of the archaeological objects, as well as about their present state, and lead to recommendations for restoration and preservation. Copyright © 2002 John Wiley & Sons, Ltd.
Atomically controlled processing for group IV semiconductors
Authors: Murota Junichi , Matsuura Takashi , Sakuraba Masao 
Published: October 2002

AbstractAtomic‐order surface reaction processes on the group IV semiconductor surface are formulated based on the Langmuir‐type surface adsorption and reaction scheme. In in situ doped Si1−xGex epitaxial growth on the (100) surface in an SiH4–GeH4–dopant (PH3, B2H6 or SiH3CH3)–H2 gas mixture, the deposition rate, the Ge fraction and the dopant concentration are explained quantitatively by assuming that the reactant gas adsorption/reaction depends on the surface site materials and that the dopant incorporation in the grown film is conducted by Henry's law. The self‐limiting formation of 1–3 monolayers of group IV or related atoms in the thermal adsorption and reaction of hydride gases (SiH4, GeH4, NH3, PH3, CH4 and SiH3CH3) on Si(100) and Ge(100) is also generalized based on the Langmuir‐type model. The Si epitaxial growth over the phosphorus layer already formed on Si(100) by PH3 treatment is achieved.Moreover, atomic layer‐by‐layer etching of Si and Ge is achieved by alternate chlorine supply and irradiation of low‐energy Ar+ ions, where the chlorine adsorption is described by the Langmuir‐type model. Silicon nitride is also etched layer by layer via a role‐share method with an argon and hydrogen mixed plasma.These results open the way to atomically controlled processing for ultra‐large‐scale integration. Copyright © 2002 John Wiley & Sons, Ltd.
Electrochemical reduction of CO2 at copper electrodes and its relationship to the metal surface characteristics
Authors: Momose Y. , Sato K. , Ohno O. 
Published: October 2002

AbstractThe selectivity of H2, CO, CH4 and C2H4 produced during the electrolysis of CO2 in aqueous solution at copper electrodes has been investigated in relation to surface analysis of the electrodes after electrolysis by XPS and temperature‐programmed photoelectron emission (TPPE) and surface potential (SP) measurements. The electrodes were prepared as follows: (A) only ultrasonic cleaning in acetone; (B) oxidation in air; (C) exposure to argon plasma. The electrolysis time was 3 h at a given potential. With electrode A, on increasing the potential in a negative direction the amount of CH4 increased, accompanied by a decrease in the amounts of H2 and CO, and the SP value was positive and shifted in a more positive direction, the TPPE activity increased and in the O1s XPS spectra a peak assigned to adsorbed oxygen developed. The amount of C2H4 was greater in the potential range where both metallic Cu and Cu2O existed. With electrode B, the main product was H2, the SP value was negative, the TPPE activity was much smaller and Cu2O existed more preferentially than metallic Cu. With electrode C, the surface underwent oxidation easily when immersed in solution. With increasing plasma treatment time the hydrocarbon products decreased, the SP value was lower and the TPPE activity was smaller. It is suggested that the adsorbed oxygen present at the electrode surfaces can lead to an increase in the number of electrons available at the surfaces and also contribute to the adsorption of CO2, resulting in hydrocarbon production. Copyright © 2002 John Wiley & Sons, Ltd.
X‐ray photoelectron spectroscopy studies of CVD diamond films
Authors: Fan Y. , Fitzgerald A. G. , John P. , Troupe C. E , Wilson J. I. B. 
Published: October 2002

AbstractIn this research work, a comparative x‐ray photoelectron spectroscopy (XPS) analysis has been performed on three allotropic carbon materials i.e. amorphous carbon films, graphite crystals and chemically vapour deposited (CVD) diamond films. These studies have shown that XPS is one of the most powerful techniques used to distinguish the diamond phase of carbon from the graphite and amorphous carbon components. In these investigations, particular attention has been paid to the effects of the post‐deposition surface treatment on the diamond surfaces and the corresponding spectrum changes. The experimental results confirmed that ion surface cleaning destroys the original carbon atomic bonding configuration and implants argon atoms into the sample surface. The main spectral changes for amorphous carbon, graphite and diamond materials after the ion etching process can be attributed to bonding modification and the existence of argon contamination on the sample surfaces. Copyright © 2002 John Wiley & Sons, Ltd.
Atomic force microscopy imaging and cutting of beaded carbon nanotubes deposited on glass
Authors: Singjai P. , Songmee N. , Tunkasiri T. , Vilaithong T. 
Published: October 2002

AbstractWe use contact force mode atomic force microscopy (AFM) to study the structures and to cut carbon nanotubes (CNTs) adsorbed on a glass slide. In addition to regular CNTs, beaded carbon nanotubes (BCNTs) were also observed when preparing products using electric current heating with the pencil technique. Imaging by contact force mode AFM could be achieved at low contact force, whereas cutting could be operated at a higher contact force in conjunction with the y‐scan direction being disabled. Cutting of BCNTs can be done without any translation of the beaded tubes. It is believed that the similar ingredients of the beaded oxides and the glass slide make them bond preferentially by chemical force. Furthermore, the morphologies were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Copyright © 2002 John Wiley & Sons, Ltd.
Dynamic modelling of a challenge‐escalation cross‐over study of treatment of capsaicin‐induced coughing
Authors: Lindsey J. K. , Stevens J. W. , Jones B. , Jackson D. 
Published: October 2002

AbstractIn a complex seven‐period cross‐over trial to study the effects of a drug in attenuating capsaicin‐induced coughing, counts of numbers of coughs were recorded 32 times in each period. Subjects were subjected to four escalating levels of capsaicin at each of one and five hours after treatment, with counts of coughs being recorded in four one‐minute intervals at each level. Such longitudinal count studies often show considerable individual variability about any regression curve that might be fitted. We develop a non‐linear autoregressive model for such count data that also allows for overdispersion. Copyright © 2002 John Wiley & Sons, Ltd.
Sources of stress in Australian adolescents: factor structure and stability over time
Authors: Byrne D. G. , Mazanov J. 
Published: October 2002

AbstractAdolescent stress is an emerging area of importance in considerations of the health of young people. Exposure to stress predicts a range of both physical and mental health problems in adolescents and relates, as well, to the initiation of important health risk behaviours. Yet the measurement of stress in adolescents has been as fraught with methodological difficulty as it has been for adults. This paper examines the Adolescent Stress Questionnaire (ASQ) which was developed specifically to address the domain of stressors specific to adolescent experience and looks at three cohorts of responses to this questionnaire over time (1995, 1998 and 2001). It assesses the stability of the original 7‐factor structure of the ASQ over time, and while confirmatory factor analysis indicates that stability to be acceptable, it also suggests that either adolescent stressors themselves, or the language by which they are reported, vary sufficiently over time to warrant the refinement of the instrument. Copyright © 2002 John Wiley & Sons, Ltd.
Muscarinic receptors involved in the subthreshold cholinergic actions of neostriatal spiny neurons
Authors: Figueroa Alejandra , Galarraga Elvira , Bargas José 
Published: October 2002

AbstractAdministration of the peptide MT‐1 (48 nM), a selective agonist of muscarinic M1‐type receptors, mimicked the subthreshold actions of muscarine (1 μM) on neostriatal neurons, i.e., it produced a reduction in subthreshold inward rectification leading to an enhancement in input resistance (RN) and evoked discharge. In all recorded cells, MT‐1 effects remained in the presence of the specific peptidergic antagonist of the M4‐type receptor, MT‐3 (10 nM), but were blocked by the specific M1‐type receptor antagonist MT‐7 (5 nM). These results suggest that most muscarinic facilitatory actions in the subthreshold voltage range occur through M1‐type receptors. However, in a fraction of cells (40%) muscarine produced an excitability enhancement not blocked by MT‐7. This additional facilitatory action, not present when using MT‐1, was blocked by MT‐3, suggesting it was mediated by M4‐type receptor activation. This facilitation could not be blocked by Cs+, TTX, or Cd2+, but only by a reduction in extracellular sodium. This result is the first evidence that M4‐type receptor activation enhances a cationic inward current in a fraction of neostriatal projection neurons. Synapse 46:215–223, 2002. © 2002 Wiley‐Liss, Inc.
Endogenous cannabinoid, anandamide, acts as a noncompetitive inhibitor on 5‐HT3 receptor‐mediated responses in Xenopus oocytes
Authors: Oz Murat , Zhang Li , Morales Marisela 
Published: October 2002

AbstractThe cloned 5‐HT3 receptor from NCB‐20 neuroblastoma cells was expressed in Xenopus oocytes and the effect of the endogenous cannabinoid ligand, anandamide, was investigated on the function of this receptor. The oocytes expressing the cloned 5‐HT3 receptors were voltage‐clamped at −70 mV. Anandamide, at the concentration range of 0.1–100 μM, reversibly inhibited 1 μM 5‐HT induced currents. The inhibition of 5‐HT induced currents by anandamide was concentration‐dependent with an EC50 of 3.7 μM and slope value of 0.94. This inhibitory effect was not dependent on the membrane potential and anandamide did not have an effect on the reversal potential of 5‐HT‐induced currents. In the presence of 10 μM anandamide, the maximum 5‐HT‐induced response was also inhibited and the respective EC50 values were 3.4 μM and 3.1 μM in the absence and presence of anandamide, indicating that anandamide acts as a noncompetitive antagonist on 5‐HT3 receptors. CB1 receptor antagonist SR‐141716A (1 μM) and pertussis toxin (5 μg/ml) did not cause a significant change on the inhibition of 5‐HT responses by anandamide. The effect of anandamide was not changed by preincubating the oocytes with 0.2 mM 8‐Br‐cAMP, a membrane‐permeable analog of cAMP, or Sp‐cAMPS (0.1 mM), a membrane‐permeable protein kinase A activator. These results suggest that the effect of anandamide is independent of the activation of cAMP pathway and not mediated by the activation of PTX sensitive G‐proteins. In conclusion, we demonstrated that the endogenous cannabinioid anandamide inhibits the function of 5‐HT3 receptors expressed in Xenopus oocytes in a cannabinoid‐receptor independent and noncompetitive manner. Synapse 46:150–156, 2002. Published 2002 Wiley‐Liss, Inc.
Septation of the anorectal and genitourinary tracts in the human embryo: Crucial role of the catenoidal shape of the urorectal sulcus
Authors: Rogers Daniel S. , Paidas Charles N. , Morreale Robert F. , Hutchins Grover M. 
Published: October 2002

AbstractBackgroundPrevious studies of the tracheoesophageal sulcus and the sulci of the developing heart have suggested that the catenoidal or saddle‐shaped configuration of the sulcus had mechanical properties that were important to developmental processes by causing regional growth limitation. We examined the development of the human perineal region to determine if a similar configuration exists in relation to the urorectal septum. We wished to re‐examine the controversial issue of the role of the urorectal sulcus in the partitioning of the cloaca.MethodsDigitally scanned photomicrographs of serial histologic sections of embryos from Carnegie stages 13, 15, 18, and 22, obtained from the Carnegie Embryological Collection were used. Each image was digitally stacked, aligned, and isolated using image‐editing software. Images were compiled using 3‐D image‐visualization software (T‐Vox), into full 3‐D voxel‐based volume renderings. Similarly, digital models were made of the urogenital sinus, anorectum, cloaca, allantois, mesonephric ducts, ureters, and kidneys by isolating their associated epithelium in each histologic section and compiling the data in T‐Vox. Methods were developed to create registration models for determining the exact position and orientation of outlined structures within the embryos.ResultsModels were oriented and resectioned to determine the configuration of the urorectal sulcus. The results show that the urorectal sulcus maintains a catenoidal configuration during the developmental period studied and, thus, would be expected to limit caudal growth of the urorectal septum.ConclusionThe observations support the concept that the urorectal septum is a passive structure that does not actively divide the cloaca into urogenital and anorectal components. Teratology 66:144–152, 2002. © 2002 Wiley‐Liss, Inc.