bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of the laser‐induced lens generated in guest‐host liquid crystals
Authors: Morisaki Takashi , Ono Hiroshi 
Published: October 2004

AbstractWe used the high‐efficiency nonlinear optical effect caused by the photothermal effect of guest‐host (dye‐doped) liquid crystals to form a laser‐induced concave lens by irradiation with a Gaussian beam. The process for forming the laser‐induced concave lens was identified by adapting diffraction theory to the pump‐probe method. We also considered the anisotropy of the thermal conductor in the liquid crystal layer and could explain the laser‐induced concave lens characteristics observed in practice including the dependence on the dye concentration and the effect of the thickness of the liquid crystal layer from the results of three‐dimensional heat conduction analysis. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 87(11): 10–19, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20085
Acquisition and organization of personal knowledge through WWW browsing
Authors: Takashiro Toru , Takeda Hideaki 
Published: October 2004

AbstractThe purpose of this paper is to construct a system to support the process whereby the user acquires knowledge by viewing electronic documents, including documents on the World Wide Web (WWW). The paper focuses on the structure of the individual knowledge and the context that forms its background, based on the experience, interests, and concerns of the individual user. A system called “MindHeap,” which models the structure of the individual knowledge in the system by interaction with the user, and presents the information to the user on the basis of that model, was previously implemented. The system has a function allowing interaction with the user in addition to the functions of an ordinary WWW browser. The user can input the part of the document that is of interest by tracing it on the screen. As a result of repeated input, the structure of the individual knowledge is automatically rearranged and systematized on the basis of the input and its context. Thus, the system supports the user with information in various formats. Evaluation experiments of the system are presented in this paper, demonstrating that the technique works effectively. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 87(11): 38–48, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20127
Construction of image processing procedures from a small number of learning samples using the IMPRESS vision expert system
Authors: Hamada Toshihiro , Shimizu Akinobu , Hasegawa Jun‐ichi , Toriwaki Jun‐ichiro 
Published: October 2004

AbstractIMPRESS is an image processing expert system in which the objective of processing is presented in the form of a figure (called the sample figure), and the image processing procedure to extract the corresponding figure from the original image is automatically generated. The authors have already considered the case in which multiple pairs of the original image and the sample figure are input, and have developed a procedure consolidating function whereby a procedure that works effectively in common for all pairs is generated. However, when the procedure is consolidated from a small number of learning samples, there is a problem with the effectiveness of the procedure. Specifically, when the consolidated function is applied to the ensemble of samples, the performance is sometimes greatly degraded compared to that for the learning samples. Consequently, we propose the following method. The deviation of the average score for the learning samples from the average score for the ensemble is estimated in the probabilistic sense. Then, by specifying the range of procedure search, a procedure with high versatility is derived from a small number of samples. In this study, the method under consideration is applied to the problem of automatic procedure construction for a procedure for defect extraction from real LSI package surfaces. The effectiveness of the method is investigated by comparing the result to the conventional consolidation procedure. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 87(11): 49–62, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20128
An in situ Template Route for Fabricating Metal Chalcogenide Hollow Spherical Assemblies Sonochemically
Authors: Xu Shu , Wang Hui , Zhu Jun‐Jie , Xin Xin‐Quan , Chen Hong‐Yuan 
Published: October 2004

AbstractAn ultrasound‐assisted in situ template approach has been developed for fabricating a series of nanoscale metal chalcogenides in the form of well‐defined hollow spherical assemblies. These hollow spherical assemblies have well‐controlled dimensions and are composed of uniform nanoparticles. Initially, metal hydroxide particles self‐assemble into spherical templates generated in situ, and subsequent surface crystal growth leads to hollow spherical structures. Ultrasound irradiation plays a critical role both in the formation of the intermediate templates and in the crystal‐growth process. This approach provides a convenient and efficient one‐step pathway to the large‐scale fabrication of hollow spherical nanostructures. It also represents a new demonstration of sonochemical effects on the formation and assembly of crystalline particles on the nanometer scale. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Incorporation of Inorganic Anions in Calcite
Authors: Kontrec Jasminka , Kralj Damir , Brečević Ljerka , Falini Giuseppe , Fermani Simona , Noethig‐Laslo Vesna , Mirosavljević Krunoslav 
Published: October 2004

AbstractA number of analytical methods and techniques (X‐ray diffraction, FT‐IR and electron paramagnetic resonance spectroscopy, ionic chromatography, scanning electron microscopy, etc.) have been used to study the mode and sites of incorporation of some common inorganic anions (SO42−, NO3− and Cl−) in the calcite crystal lattice. Calcite, the thermodynamically stable calcium carbonate polymorph under standard conditions, was prepared by spontaneous precipitation from calcium hydroxide and carbonic acid solutions. The particular co‐anion was added into the carbonic acid solution in the form of a calcium salt before mixing the reactants. The system prepared in such a way is particularly suitable for investigating the mode of foreign anion incorporation into the crystal lattice of calcite. Apart from the constituent ions and the products of water protolysis, this system contains only the co‐anion examined. In order to study the local environment in the calcite crystal lattice by EPR spectroscopy, Mn2+ was used as a paramagnetic substitute for Ca2+. The experiments were performed at 25 °C and the samples for analyses were taken after a predetermined ageing time of 20 min. It was found that the co‐anions, when added in the concentrations examined, did not affect the morphology of the calcite crystals but were incorporated into the calcite structure. The largest distortion of the calcite structure was obtained when sulfate ions were added. The measured parameters of the calcite unit cell are given, the results obtained are discussed and a model that explains the possible mode and sites of sulfate incorporation is presented. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Luminescent Zn and Cd Coordination Polymers
Authors: Jiang Chao , Yu Zhaopeng , Jiao Chao , Wang Sujing , Li Jiaming , Wang Zhiyong , Cui Yong 
Published: October 2004

AbstractThe hydrothermal reactions of Zn(ClO4)2·6H2O and Cd(ClO4)2·6H2O with 1,3‐bis(2H‐tetrazol‐5‐yl)benzene in an aqueous ethanol and an aqueous methanol/pyridine medium, respectively, yielded a 3D and a 2D metal‐organic coordination framework [Zn(1,3‐BTB)] (1) and [Cd(1,3‐BTB)2(Py)2(H2O)2] [Cd[Cd(Py)(H2O)]2(1,3‐BTB)2] (2) (1,3‐BTB = 1,3‐ditetrazolylbenzene, Py = pyridine), respectively. Species 1 possesses an open network structure with no guest molecules residing in its small cavities. The structural characterisation of 2 shows a 2D layered framework consisting of nano‐sized polytube structures which are stacked one on top of another in the (110) plane giving small channels along the b and c axes. Additionally, compounds 1 and 2 exhibit strong fluorescence at room temperature in the solid state. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Facile [N]C−H Activation by a (P,N)‐Chelate [3]Ferrocenophane−Ruthenium System
Authors: Liptau Patrick , Carmona Daniel , Oro Luis A. , Lahoz Fernando J. , Kehr Gerald , Erker Gerhard 
Published: October 2004

AbstractThe chelate ligand 5 was prepared from the corresponding (dimethylamino)[3]ferrocenophane by directed ortho‐lithiation with n‐butyllithium followed by treatment with ClPPh2. The rigid (P,N)‐chelate ligand reacts with [Ru(η6‐p‐cymene)Cl2] dimer in the presence of KPF6 in methanol to afford two products in an almost equimolar ratio. Instead of the simple addition product of the [Ru(p‐cymene)Cl]+ cation reagent to the chelate, selective C−H abstraction at an N−CH3 moiety occurs with the formation of the “metallaaziridinium”‐type product 8 (isolated as its PF6− salt). The liberated equivalent of HCl is trapped by the putative (P,N)‐chelate [RuCl]+ complex intermediate to form the corresponding internal hydrochloride complex 7. The starting material 5 and the products 8 and 7 were characterised by single‐crystal X‐ray diffraction studies. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Binucleating Aza‐Sulfonate and Aza‐Sulfinate Macrocycles — Synthesis and Coordination Chemistry
Authors: Hausmann Julia , Käss Steffen , Klod Sabrina , Kleinpeter Erich , Kersting Berthold 
Published: October 2004

AbstractThe preparation and ligating properties of S‐oxygenated derivatives of a macrobinucleating hexaazadithiophenolate macrocycle H2L1 of the Robson type towards nickel(II) and zinc(II) ions are reported. Nickel complexes of the hexaazadiphenylsulfonate ligand (L2)2− [(L2)NiII2(μ‐L)]+ (L = m‐Cl‐OBz− (3), Cl− (4) and OAc− (6)] are readily obtained in high yields by oxidation of the respective [(L1)NiII2(μ‐L)]+ parent complexes [L = m‐Cl‐OBz− (2), Cl− (1), OAc− (5)] with meta‐chloroperoxybenzoic acid or hydrogen peroxide. Decomposition of the sulfonate complexes gives the free macrocycle H2L2 which, upon treatment with Zn(OAc)2·2H2O, produces the diamagnetic zinc complex [(L2)ZnII2(OAc)]+ (8). A dinuclear CuII complex of the hexaazadisulfinate derivative (L3′)2−, [(L3)CuII2]2+ (9), is formed rather unexpectedly by air oxidation of (L1)2− in the presence of CuI. The crystal‐structure determinations of the perchlorate or tetraphenylborate salts of 2, 3, and 4 show that the new ligands support the formation of binuclear complexes with bowl‐shaped, calixarene‐like binding cavities. NMR spectroscopic studies of 8 show that the complexes retain their solid‐state structures in solution. A crystal‐structure determination of 9 reveals two five‐coordinate CuII ions bridged by the two sulfinate functions of (L3)2−. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis of (Vinylidene)‐ and (Cyclopropenyl)ruthenium Complexes Containing a Tris(pyrazolyl)borato (Tp) Ligand
Authors: Lo Yih‐Hsing , Lin Ying‐Chih , Lee Gene‐Hsiang , Wang Yu 
Published: October 2004

AbstractA convenient high‐yield route to [Ru(C≡C−Ph)(Tp)(PPh3)2] [2; Tp = HB(pz)3, pz = pyrazolyl] has been found through the intermediacy of [RuCl2(Hpz)2(PPh3)2] (1). This complex is readily obtained on treatment of [RuCl2(PPh3)3] with 2 equiv. of pyrazole in boiling THF. The molecular structures of complexes 1 and 2 have been confirmed by single‐crystal X‐ray diffraction analysis. A number of new cationic vinylidene complexes [Ru{=C=C(Ph)CH2R}(Tp)(PPh3)2]+ [3a, R = CN; 3b, R = HC=CH2; 3c, R = CH=C(CH3)2; 3d, R = Ph; 3e, R = C(O)OMe] have been prepared by electrophilic addition of organic halides to complex 2. The deprotonation reaction of 3a yields the cyclopropenyl complex 4a. One phosphane ligand of 4a is remarkably labile, being replaced by donor ligands L to yield diastereomeric mixtures of the cyclopropenyl complexes 5a−5d mostly in an approximate 4:1 ratio. The cyclopropenyl rings in 4a and 5a are susceptible to ring opening by I2. In addition, treatment of 4a with nBuNC in the presence of MeOH results in substitution of a phosphane ligand by nBuNC followed by protonation of the three‐membered ring by MeOH. This is then followed by addition of methoxide to give the vinyl ether complex [Ru{C(OMe)=C(Ph)CH2CN}(Tp)(PPh3)(nBuNC)] (8a). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis of a Fluorescent Sulfatide for the Study of CD1 Antigen Binding Properties
Authors: Franchini Laura , Compostella Federica , Donda Alena , Mori Lucia , Colombo Diego , De Libero Gennaro , Matto Pamela , Ronchetti Fiamma , Panza Luigi 
Published: October 2004

AbstractA fluorescent derivative of sulfatide, labeled with a dansyl probe at position 6 of galactose, was prepared through a glycosylation reaction between a 6‐O‐functionalized galactose donor and 3‐O‐benzoyl‐azidosphingosine. The sphingoid acceptor was obtained in high yield through exploitation of a highly stereoselective nucleophilic addition of pentadecyne to 2,3‐O‐cyclohexylidene‐D‐glyceraldehyde. The fluorescent sulfatide binds to soluble recombinant human CD1a and is a valuable tool for the study of CD1 antigen binding properties. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Adsorption and Reactivity of Chlorogenic Acid at a Hydrophobic Carbon Ceramic Composite Electrode: Application for the Amperometric Detection of Hydrazine
Authors: Salimi Abdollah , Hallaj Rahman 
Published: October 2004

AbstractSol‐gel technique was used for construction of a carbon composite electrode. The prepared carbon ceramic electrode was modified with electroless deposition of chlorogenic acid for less than 1 min. The adsorbed thin films of chlorogenic acid on carbon composite electrode show one pair of peaks with a surface confined characteristic, which strongly depends on the solution pH, as anticipated for quinone /hydroquinone functionalities. The modified electrode shows highly catalytic activity toward hydrazine electrooxidation at wide pH range (5–11). Also the rotating modified electrode shows excellent analytical performance for amperometric determination of hydrazine. The detection limit, sensitivity, response time and linear dynamic range are 20 nM, 220 nA / μM, 1 second and 0.1 μM‐1 mM, respectively. The catalytic rate constant for hydrazine oxidation at the surface of modified electrode was evaluated by cyclic voltammetry and was found to be around 1.5×103 M−1s−1in phosphate buffer solution (pH 8). The precision of chronoamperometric measurements was 1–3% for 5 replicate determinations in the concentration range of the linear calibration. The reproducibility of modified CCE was evaluated with 8 successive polishing and modifications and then the anodic peak current was measured (RSD 2%). The advantages of this sensor are excellent catalytic activity, high sensitivity, good reproducibility and simplicity of preparation at short time periods.
Renewable Surface Sol‐gel Derived Carbon Ceramic Electrode Modified with Copper Complex and Its Application as an Amperometric Sensor for Bromate Detection
Authors: Salimi Abdollah , Alizadeh Vali , Hadadzadeh Hasan 
Published: October 2004

AbstractA sol‐gel technique was used for the preparation of a three dimensional carbon composite electrode modified with [Cu(bpy)2]Br2 complex. A reversible redox couple of Cu(II)/Cu(I) is observed at the electrode surface. The electrochemical behavior and stability of the modified electrode was characterized by cyclic voltammetry. The charge transfer coefficient (α) and charge transfer rate constant (Ks) for the modified electrode were determined by cyclic voltammetry, which were found to be 0.46 and 14.2 s−1, respectively. The modified electrode showed excellent catalytic activity toward bromate reduction at significantly reduced overpotentials and can be used successfully for amperometric detection of bromate. Under the optimized conditions, the calibration plots are linear in the concentration range 0.5 μM −200μM. Detection limit (signal to noise is 3) and sensitivity were found to be 0.1 μM and 20 nA / μM, respectively. These analytical parameters compare favorably with those obtained with modern analytical techniques. The modified carbon ceramic electrode doped with Cu‐Complex shows a good reproducibility, a short response time (t<2 s), remarkable long term stability (>4 months) and especially good surface renewability by simple mechanical polishing (RSD for 6 successive polishing is 1.5%).
Binding of Copper(II) to Pectins by Electrochemical Methods
Authors: Vilhena C. , Gonçalves M. L. , Mota A. M. 
Published: October 2004

AbstractThe interaction between Cu(II) and pectin extracted from citrus fruit was studied in KNO3 0.10 mol dm−3 at 25 °C and pH 5.5, using ion selective electrode potentiometry and voltammetry, namely differential pulse polarography and square‐wave voltammetry. Although many independent variables may affect Cu(II)‐polymer interactions such as charge density, polymer concentration and copper to polymer concentration ratio, a good fitting was observed for the model with ML and ML2 complex species, when M:L total concentration (mol dm−3) ratio varies from 0.2 to 2.7 and the ligand concentration is in the range (0.2 to 1) g dm−3, i.e., (0.4 to 2)×10−3 mol COO− dm−3. The complex parameters found in these conditions were log βCuL=3.5±0.1 and log βCuL2= 8.0±0.2. For lower total ligand and total metal ion concentrations, used in voltammetry, the interaction Cu(II)‐pectin is affected by a cooperative mode (increase of metal ion‐ligand affinity) when the total metal ion concentration increases and by an anti‐cooperative mode when the total ligand concentration increases, possibly due to different conformations of the polymer.
Enzymatic Biosensor Based on the ISFET and Photopolymeric Membrane for the Determinaion of Urea
Authors: Rebriiev A. V. , Starodub N. F. 
Published: October 2004

AbstractAn ISFET based enzymatic biosensor was developed for the determination of urea. Immobilization of urease was accomplished by the use of liquid mixture which contained vinylpyrrolidone, oligouretane metacrylate and oligocarbonate metacrylate and which can form a polymer under the influence of ultraviolet. The biosensor has the following characteristics: the linear field of responses is in the range of 0.05–20 mM, curve slope – 38 mV/pC, and response time 5–10 min. The increase of the temperature from 28 to 41 °C leads to 15% increase in the intensity of the response of the biosensor. The maximum response is observed at pH 6.0–6.5. At the increase of the NaCl concentration in solution up to 300 mM the biosensor response drops off and achieves half of its initial level. NH4Cl causes a stronger inhibition of enzyme activity comparing to NaCl. The results obtained with the developed biosensor correlate with the data of standard calorimetric methods. The intensity of the biosensor response decreases gradually during 40 days up to 80% of the initial level. The biosensors prepared with a fresh membrane or membrane preserved during 46 days at 2 °C gave similar responses in solution with an equal concentration of a substrate. It is concluded that the developed enzymatic biosensor is perspective for its clinical application for the determination of urea in blood and that the proposed method to prepare a selective biological membrane may be in a simple way included in integral technology of the semiconductor transducer manufacturing.
FET‐Based Biosensors for The Direct Detection of Organophosphate Neurotoxins
Authors: Simonian A. L. , Flounders A. W. , Wild J. R. 
Published: October 2004

AbstractRecent world‐wide terrorist events associated with the threat of hazardous chemical agent proliferation, and outbreaks of chemical contamination in the food supply has demonstrated an urgent need for sensors that can directly detect the presence of dangerous chemical toxins. Such sensors must enable real‐time detection and accurate identification of different classes of pesticides (e.g., carbamates and organophosphates) but must especially discriminate between widely used organophosphate (OP) pesticides and G‐ and V‐type organophosphate chemical warfare nerve agents. Present field analytic sensors are bulky with limited specificity, require specially‐trained personnel, and, in some cases, depend upon lengthy analysis time and specialized facilities. Most bioanalytical based systems are biomimetic. These sensors utilize sensitive enzyme recognition elements that are the in‐vivo target of the neurotoxic agents which the sensor is attempting to detect. The strategy is well founded; if you want to detect cholinesterase toxins use cholinesterase receptors. However, this approach has multiple limitations. Cholinesterase receptors are sensitive to a wide range of non‐related compounds and require lengthy incubation time. Cholinesterase sensors are inherently inhibition mode and therefore require baseline testing followed by sample exposure, retest and comparison to baseline. Finally, due to the irreversible nature of enzyme‐ligand interactions, inhibition‐mode sensors cannot be reused without regeneration of enzyme activity, which in many cases is inefficient and time‐consuming. In 1996, we pioneered a new “kinetic” approach for the direct detection of OP neurotoxins based on agent hydrolysis by the enzyme organophosphate hydrolase (OPH; EC 3.1.8.2; phosphotriesterase) and further identified a novel multi‐enzyme strategy for discrimination between different classes of neurotoxins. The major advantage of this sensor strategy is it allows direct and continuous measurement of OP agents using a reversible biorecognition element. We also investigated incorporation of enzymes with variations in substrate specificity (e.g., native OPH, site‐directed mutants of OPH, and OPAA (EC 3.1.8.1), based upon preferential hydrolysis of PO, PF and PS bonds to enable discrimination among chemically diverse OP compounds. Organophosphate hydrolase enzymes were integrated with several different transduction platforms including conventional pH electrodes, fluoride ion‐sensitive electrodes, and pH‐responsive fluorescent dyes. Detection limit for most systems was in the low ppm concentration range. This article reviews our integration of organophosphate hydrolase enzymes with pH sensitive field effect transistors (FETs) for OP detection.
Purification of the Escherichia coli K5 capsular polysaccharide and use of high‐performance capillary electrophoresis to qualitative and quantitative monitor the process
Authors: Volpi Nicola 
Published: October 2004

AbstractA rapid, highly sensitive, and reproducible high‐performance capillary electrophoresis (HPCE) method (electrokinetic chromatography with sodium dodecyl sulfate) is described for the determination of the polysaccharide from the uropathogenic Escherichia coli K5 bacteria Bi8337/41 010:K5:H4. This natural polysaccharide having the structure of a desulfo‐heparin composed of ‐4)‐αGlcUA‐(1,4)‐α‐GlcNAc‐(1‐ is separated (GlcUA = D‐glucuronic acid; GlcNAc = D‐glucosamine) and qualitatively and quantitatively determined within 20 min on an uncoated fused‐silica capillary using normal polarity at 20 kV and detection at 200 nm. A linear relationship (correlation coefficient > ∼0.99) was found for the polymer over a wide range of concentrations, from approx. 60 to 1500 ng, with a detection sensitivity of < ∼60 ng. Furthermore, this qualitative and quantitative HPCE approach was applied to the K5 extraction and purification process from cultured bacteria in several stages. HPCE was also able to separate several molecular species mainly due to the presence of polysaccharides of distinct and increasing mean chain lengths. A linear relationship was found for migration time and log molecular mass of different K5 polysaccharide species, and this model was used to calculate the molecular mass of the main K5 species producing a result of approx. 17 000, also confirmed by high‐performance size‐exclusion chromatography analysis, yielding approx. 17 200.