bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling and H∞ control of a single-link flexible manipulator
Authors: Sutton R P , Halikias G D , Plummer A R , Wilson D A
Published: November 2002

The aim of this study is to investigate motion in the horizontal and the vertical planes of a single-link flexible manipulator. The manipulator is modelled including gravity terms, and it is verified experimentally that the horizontal and the vertical motions are decoupled for a cylindrically symmetrical link and payload. The mathematical model is used to design a mixed-sensitivity H∞ contrlllerr. The sensitivity weighting function is used to obtain the required disturbance rejection properties, including zero sensitivity to a force disturbance in the steady state (i. e. integral action control). The control sensitivity weighting function is chosen to guarantee stability despite variation in the payload mass. The controller is compared experimentally with a proportional-plus-integral controller with velocity feedback and shown to give improved vibration control performance in the vertical plane.
Non-linear system identification using genetic algorithms
Authors: Luh G-C , Wu C-Y
Published: November 2002

In this paper, a genetic-algorithm-based non-linear autoregressive with exogenous inputs system identification (GANARXSI) algorithm was developed to identify non-linear systems and was successfully applied to both non-linear continuous-time and discrete-time systems with acceptable accuracy. This algorithm can achieve robustness and efficiency in identifying complex non-linear systems. The effects of different combinations of operators of genetic algorithms are also studied and an operator of truncate mutation was proposed to improve greatly the convergence rate in identification process. An identified non-linear coupled liquid-level system is used to evaluate the performance of the algorithm. An experimental verification is carried out in a dynamometer engine test cell and the identified engine model during the I/M240 driving cycle is also used to validate the proposed methodology. After testing the algorithm for different complex non-linear systems, the GANARXSI algorithm proved to be a practical technique of identification for non-linear systems.
A randomized integral error criterion for parametric identification of dynamic models of mechanical systems
Authors: Best M C , Gordon T J
Published: November 2002

This paper proposes a new approach to the identification of reduced order models for complex mechanical vibration systems. Parametric identification is commonly conducted by the regression of time-series data, but when this includes significant unmodelled modes, the error process has a high variance and autocorrelation. In such cases, optimization using least-squares methods can lead to excessive parameter bias. The proposed method takes advantage of the inherent boundedness of mechanical vibrations to design a new regression set with dramatically reduced error variance.

The principle is first demonstrated using a simple two-mass simulation model, and from this a practicable approach is derived. Extensive investigation of the new randomized integral error criterion method is then conducted using the example of identification of a quarter-car suspension system. Simulation results are contrasted with those from comparable direct least-squares identifications. Several forms of the identification equations and error sources are used, and in all cases the new method has clear advantages, both in accuracy and consistency of the resulting identification model.
Adaptive fuzzy logic control of engine idle speed
Authors: Thornhill M , Thompson S
Published: November 2002

The presented control scheme utilizes adaptive fuzzy logic to track a reference engine rotational speed during engine idling. The idle speed system is described and the non-linearity of the system and the presence of a variable time delay highlighted. To evaluate the performance of the controller a model of the system is developed and simulation results presented. Engine test results are also presented and compared with simulation results. It is shown that the Wang adaptive fuzzy logic algorithm is incapable of controlling systems with large time delays. This problem is solved in simulation using the Wang adaptive fuzzy logic algorithm in conjunction with the Smith prediction.
Robust friction compensation for precise and smooth position regulation
Authors: Song G , Cai L , Wang Y
Published: November 2002

In this paper, a smooth robust time-varying controller is proposed to regulate a servo-system with stick-slip friction. The controller has the advantage of simultaneously achieving zero regulating error and smoothness of motion. Only an upper bound on the maximum static friction torque is required for controller design. Lyapunov's second method is employed to prove the global asymptotic stability of the closed-loop system. Numerical simulations of regulating a servo-system with friction are presented as an illustration.
(Salen)ruthenium-Catalyzed Desymmetrization of Meso-Diols: Catalytic Aerobic Asymmetric Oxidation under Photo-Irradiation
Authors: Shimizu Hideki , Nakata Kenya , Katsuki Tsutomu
Published: November 2002

Catalytic aerobic oxidation of meso-diols using (nitrosyl)Ru(salen) 7 as the catalyst under photo-irradiation proceeded with moderate enantioselectivity (up to 67% ee) to give the corresponding lactols.
AgOAc-Catalyzed Aldehyde Allylation Using Allyldimethyl(2-pyridyl)silane
Authors: Itami Kenichiro , Kamei Toshiyuki , Mineno Masahiro , Yoshida Jun-ichi
Published: November 2002

Silver salts having relatively strong Ag–O bond were found to promote the allylation of aldehydes with allyldimethyl(2-pyridyl)silane. Catalytic allylation is also possible when AgOAc was employed. A novel cooperative activation of allyl(2-pyridyl)silane has been implicated from several control experiments.
Electroplating of Nanostructured Nickel in Emulsion of Supercritical Carbon Dioxide in Electrolyte Solution
Authors: Yoshida Hideo , Sone Masato , Mizushima Aya , Abe Kentaro , Tao Xu Tang , Ichihara Shoji , Miyata Seizo
Published: November 2002

We report electroplating in emulsion of supercritical carbon dioxide and electrolyte solution for the first time. Compared to conventional electroplating, this technology has advantages in covering, leveling and throwing effects on plating. Moreover the particle sizes of plated nickel are sub-100 nm.
Synthesis of Thermally Stable Cs-Doped Alumina Nanoparticles by Microemulsion Method
Authors: You Zhixiong , Balint Ioan , Aika Ken-ichi
Published: November 2002

Cs-doped alumina nanoparticles were synthesized by microemulsion method and then characterized. Cs-doping greatly improved aluminas thermal stability. For an optimum molar ratio of Cs/Al = 1/11 the structure of γ-alumina can be preserved even at temperatures as high as 1330 °C.
Preparation of a Hollow Microsphere Composed of Porous Organic-Inorganic Hybrid Wall in a W/O Microemulsion System
Authors: Mishima Shozi , Kawamura Morinobu , Matsukawa Shohei , Nakajima Tsuyoshi
Published: November 2002

Hollow microspheres composed of organic-inorganic hybrid wall (polyorganosiloxane) have been synthesized as a new material in a W/O emulsion system from organosilanes. The average diameter of spheres for a typical run is 1.8 μm (standard deviation = 0.84) with a large spherical cavity in them and thermally stable at least up to 400 °C in air. The polyorganosiloxane wall is amorphous and becomes porous by treating at around 400 °C in air.
Sulphidization of Metal Oxides by Means of Mechanochemical Solid Reaction
Authors: Zhang Qiwu , Wang Jun , Saito Fumio , Okura Takahiko , Nakamura Isao
Published: November 2002

Co-grinding nonferrous metal oxides and sulphur together with iron/aluminium metal stimulates a solid-state reaction to form the nonferrous metal sulphides and iron/aluminium oxide, allowing the use of the current mineral processing technologies to recover metals from various kinds of wastes.
A Unique Double Strand Consisting of Siloxane-Type Macrocycles
Authors: Jung Ok-Sang , Lee Young-A , Kim Yun Ju
Published: November 2002

Reaction of AgCF3SO3 with 1,5-bis(3-pyridyl)hexamethyltrisiloxane produces a unique double strand consisting of siloxane macrocycles that is sustained by both the π–π stackings of pyridine rings and the strong Ag(I)–Ag(I) interactions.
Convenient Synthesis of the Main Dehydrohexapeptide Skeleton Constituting a Macrocyclic Antibiotic, Berninamycin A
Authors: Saito Hirohumi , Yamada Takahiro , Okumura Kazuo , Yonezawa Yasuchika , Shin Chung-gi
Published: November 2002

The first convenient synthesis of the main dehydrohexapeptide segment of a macrocyclic antibiotic, berninamycin A, containing a 3-hydroxy-l-valine residue and having three vinyl groups and a 1-propenyl group, was accomplished.
Environmentally Benign and Stereoselective Construction of 2-Deoxy and 2,6-Dideoxy-β-glycosidic Linkages Employing 2-Deoxy and 2,6-Dideoxyglycosyl Phosphites and Montmorillonite K-10
Authors: Nagai Hideyuki , Matsumura Shuichi , Toshima Kazunobu
Published: November 2002

The β-stereoselective glycosidations of 2-deoxy- and 2,6-dideoxyglycosyl diethyl phosphites with alcohols using a heterogeneous and environmentally benign solid acid, montmorillonite K-10, have been developed.
Photodimerization of Anthracene Having Dendritic Substituent within the Vaterite Crystal of CaCO3
Authors: Takaguchi Yutaka , Yanagimoto Yasushi , Tajima Tomoyuki , Ohta Kazuchika , Motoyoshiya Jiro , Aoyama Hiromu
Published: November 2002

Crystallization of CaCO3 in the presence of poly(amidoamine) (PAMAM) dendron containing an anthryl group at the focal point and carboxylate groups at the external surface resulted in the formation of spherical vaterite crystals. Furthermore, photodimerization reaction of anthracene unit proceeded within the vaterite crystals upon irradiation.
Alkylation-Acylation of Aromatics with γ-Butyrolactone Catalyzed by Heteropolyacids Supported on Silica
Authors: Mao Jianxin , Nakajo Tetsuo , Okuhara Toshio
Published: November 2002

Silica-supported H4SiW12O40 catalyzed efficiently alkylation/acylation of 1,3,5-trimethylbenzene or p-xylene with γ-butyrolactone to 4-(2,4,6-trimethylphenyl) butyric acid or to dimethyl-α-tetralone (5,8-dimethyl-3,4-dihydro-2H-naphtalen-1-one), while other typical solid acids such as zeolites and SiO2-Al2O3 were much less active.
Continuous Production of Synthesis Gas at Ambient Temperature from Steam Reforming of Methane with Nonthermal Plasma
Authors: Kabashima Hajime , Futamura Shigeru
Published: November 2002

Nonthermal plasma steam reforming of methane was carried out with two different types of reactors such as ferroelectric packed-bed (FPR) and silent discharge (SDR) in a flow reaction system. The yields of hydrogen and carbon monoxide were much higher with FPR than with SDR under the same conditions. FPR could be operated continuously for 10 h without any decrease in the yields of hydrogen and carbon monoxide.
Complexation of 4,4′-Dipyridyl Derivatives Changed the Orientations of Metalloporphyrins Linked to the Cyclic Peptide Gramicidin S
Authors: Arai Toru , Araki Koji , Fukuma Kengo , Nakashima Takaaki , Kato Tamaki , Nishino Norikazu
Published: November 2002

Pairs of Zn and Co(III) porphyrins linked to the natural cyclic β-sheet peptide, Gramicidin S, formed stable host-guest complexes with the 4,4′-dipyridyl derivatives in dichloromethane, in which the Cotton effects reflected the orientational changes of the metalloporphyrins upon the complexations.
Asymmetric 1,3-Dipolar Cycloaddition of Nitrile Oxides Generated in situ by Direct Oxidation of Aldoximes
Authors: Tsuji Masamichi , Ukaji Yutaka , Inomata Katsuhiko
Published: November 2002

The asymmetric 1,3-dipolar cycloaddition of nitrile oxides, generated in situ from aldoximes by direct oxidation with tert-butyl hypochlorite, to 2-propen-1-ol was achieved by utilizing diisopropyl (R,R)-tartrate as a chiral auxiliary to afford the corresponding (R)-2-isoxazolines with high enantioselectivity up to 96% ee.
A New Nucleophilic Catalyst for Kinetic Resolution of Racemic sec-Alcohols
Authors: Jeong Kyu-Sung , Kim Soong-Hyun , Park Hyun-Jin , Chang Kyoung-Jin , Kim Kwan Soo
Published: November 2002

A new tertiary amine-based nucleophilic catalyst, derived from a simple combination of commercially available compounds, affords good to excellent kinetic resolution of racemic sec-alcohols.
Selective Hydrogenation of Aromatic Compounds Containing Epoxy Group over Rh/Graphite
Authors: Hara Yoshinori , Inagaki Hiroko
Published: November 2002

Catalytic hydrogenation of aromatic compounds containing epoxy group to alicylic compounds has been investigated. Rh supported on graphite with high surface area exhibited superior performance to other supported catalysts for the selective reduction of the aromatic group while retaining epoxy group.
The First Organically Templated Layered Cerium Phosphate-Hydrogen Sulfate: [enH2]0.5[CeIII(PO4)(HSO4)(OH2)]
Authors: Wang Dan , Yu Ranbo , Xu Yaohua , Feng Shouhua , Xu Ruren , Kumada Nobuhiro , Kinomura Nobukazu , Matsumura Yasuyuki , Takano Mikio
Published: November 2002

A novel organically templated layered cerium phosphate-hydrogen sulfate [enH2]0.5[CeIII(PO4)(HSO4)(OH2)] has been hydrothermally synthesized. The product was further characterized by means of single-crystal and powder X-ray diffractions, TG-DTA, CHN elemental analysis, SEM, and IR. Its unique layered structure possesses cerium-centered polyhedral CeO9 as a new basic building unit. The diprotonated ethylenediamine cations contact adjacent layers via hydrogen bonds to compensate the charge of the inorganic framework.
Microscope and DSC Study of Polymorphism of 1,1′-(1,12-Dodecanediyl)bisthymine
Authors: Itahara Toshio , Kanda Junpei , Ikeda Shuji , Ueda Takehiko
Published: November 2002

1,1′-(1,12-Dodecanediyl)bisthymine exhibited two distinct types of crystals. One of them was spontaneously transformed into the other under heat treatment. This phenomenon was monitored by DSC and observed under polarizing microscope.
Synthesis of Hexakis(alkylgermasesquioxane)s from Alkyl(chloro)ethoxygermanes and Their Formation Mechanism
Authors: Nanjo Masato , Sasage Takaomi , Mochida Kunio
Published: November 2002

Alkyl(chloro)ethoxygermanes were hydrolyzed with water to give 1,3,5-trialkyl-1,3,5-trichlorocyclotrigermoxanes. Hydrolysis of 1,3,5-trichlorocyclotrigermoxanes gave 5,7-dichloro-1,3,5,7,9,11-hexaalkyltricyclo[7.3.1.13,7]hexagermoxanes. The tricylic anti-form ladder hexagermoxanes reacted with water to afford hexakis(alkylgermasesquioxane)s. These cage and ladder germoxanes were identified by spectrospcopic and X-ray diffraction methods.
Benzylation of Carboxylic Acids by Oxidation-Reduction Condensation Using Quinones and Benzyloxydiphenylphosphine
Authors: Mukaiyama Teruaki , Shintou Taichi , Kikuchi Wataru
Published: November 2002

Various carboxylic benzyl esters were obtained in high yields by way of oxidation-reduction condensation in which benzyloxydiphenylphosphine (BDPP), having been prepared easily from chlorodiphenylphosphine and benzyl alcohol, was treated with various carboxylic acids in the presence of 2,6-dimethyl-1,4-benzoquinone(DMBQ) under mild conditions.
Novel Thermosensitive Polyethers Prepared by Anionic Ring-Opening Polymerization of Glycidyl Ether Derivatives
Authors: Aoki Sayuri , Koide Aya , Imabayashi Shin-ichiro , Watanabe Masayoshi
Published: November 2002

A new series of thermo-sensitive polyethers were prepared by anionic ring-opening polymerization of glycidyl ether derivatives: glycidyl methyl ether, ethyl glycidyl ether, and ethoxyethyl glycidyl ether. The prepared polymers have controllable molecular weight with narrow molecular weight distributions. These polymers exhibit a lower critical solution temperature (LCST) in water. The LCST is altered from 14.6 to 57.7 °C by decreasing the hydrophobicity of the side-chain units.
Synchrotron Radiation Structure Analyses of the Light-induced Radical Pair of a Hexaarylbiimidazolyl Derivative. Origin of the Spin-Multiplicity Change
Authors: Kawano Masaki , Ozawa Yoshiki , Matsubara Koutatsu , Imabayashi Hidekazu , Mitsumi Minoru , Toriumi Koshiro , Ohashi Yuji
Published: November 2002

In situ synchrotron radiation structure analyses of a light-induced radical pair from o-Cl-HABI were performed by using an X-ray vacuum camera at 23–70 K at the BL02B1 station of SPring-8. The combined results of X-ray analysis with theoretical calculation, IR, and UV-vis spectroscopy reveal that a slight conformational change of the radical pair causes the drastic spin-multiplicity change during 2–140 K.
Surface Fabrication of Interconnected Hollow Spheres of nm-Thick Titania Shell
Authors: Fujikawa Shigenori , Kunitake Toyoki
Published: November 2002

Latex particles were adsorbed on solid substrate and then covered with ultrathin titania films by the surface sol-gel process. Hollow titania spheres formed after removal of the latex template by oxygen plasma treatment were connected with each other via nanotubes, reflecting the original disposition of the latex particles.
Infrared Spectroscopy of Bis(4-nitrophenyl) Disulfide Grown on a Pb Layer
Authors: McCluskey M D , Grover D I , Zhuravlev K K
Published: November 2002

Crystal whiskers of bis(4-nitrophenyl) disulfide have been grown on a 100-nm thick Pb film from a supersaturated solution of p-nitrothiophenol. The whiskers preferentially grow on Pb but not on Si, In, or Ag. The crystals were characterized by electron microscopy and infrared spectroscopy. The optimized structure of the molecule was determined by ab initio calculations.
Palladium-catalyzed Arylative Cyclizations of Allenylmalonates with Aryl Halides
Authors: Oh Chang Ho , Rhim Chul Yun , Song Chung Hyun , Ryu Jin Hyang
Published: November 2002

Palladium-catalyzed arylative cyclizations of allenylmalonates with various aryl halides gave the carbocycles with good chemoselectivity and efficiency.
The Selective 1,2-Addition of Ketene Silyl Acetals to α,β-unsaturated Ketones Promoted by a Copper(I)-Phosphine Complex
Authors: Mitani Michiharu , Ishimoto Kouji , Koyama Ryuhei
Published: November 2002

The thermal reaction of an α,β-unsaturated ketones with a ketene silyl acetal in the presence of the copper(I)halide-phosphine complex brought about the selective formation of the products based on 1,2-addition, while use of the copper(I)halide alone afforded the 1,4-adduct type of product.
Hydrothermal Synthesis of Highly Robust 2-D Layered Coordination Polymer of La
Authors: Haitao Xu , Nengwu Zheng , Xianglin Jin , Ruyi Yang , Zhengquan Li
Published: November 2002

The crystal structure of the coordination polymer: [La(C8H5NO4)1.5H2O]n is reported, and some properties are characterized. It is interesting to observe 2-D layer-structures parallel to ac plane. The TAG reveals it’s thermal high stability and the EPR spectra show that there is no odd spin electron.
The Binary Reagent (MeO)3P/Me3SiCl and (MeO)3P/CH3CO2H in 5.0 M Lithium Perchlorate/Diethyl Ether. An Efficent Route to the Preparation of α-Hydrazinophosphonates and N-Hydroxy-α-aminophosphonates
Authors: Heydari Akbar , Mehrdad Morteza , Schaffie Mehdi , Abdolrezaie M Saeid , Hajinassirei Rahimeh
Published: November 2002

α-Hydrazinophosphonates (N-hydroxy-α-aminophosphonates) are generated by lithium perchlorate-catalyzed three-component reaction of aldehydes, N,N-dimethylhydrazine (phenylhydroxylamine) and trimethylphosphite/trimethylsilyl chloride (acetic acid). The method utilizes cheaply available reagents and hence it is a practical and cost effective strategy, compared to other methods available in the literature.
Spin-trapping Study of DNA Cleavage Induced by Enediyne C-1027 Chromophore
Authors: Usuki Toyonobu , Inoue Masayuki , Akiyama Kimio , Hirama Masahiro
Published: November 2002

We report the direct observation of radical intermediates in the course of the DNA cleavage induced by the chromoprotein antitumor agent C-1027 using spin-trapping methods. An intriguing difference of behaviors was found between MNP (2-methyl-2-nitrosopropane) and DMPO (5,5-dimethyl-1-pyrroline N-oxide).
Site Control of Tunnel Etching of Al for Electrolytic Capacitors Using Pretexturing by Mold
Authors: Masuda Hideki , Tajima Minoru , Nishio Kazuyuki
Published: November 2002

Highly ordered arrays of etched tunnel pits were formed using an Al foil pretexturing process. Shallow concaves formed by imprinting Al using a mold with ordered convexes led to the formation of tunnel pits, and generated an almost ideally ordered array of etched tunnel pits propagating along the (100) plane. The obtained ordered tunnel pits were straight and perpendicular to the surface. The present process will be useful for optimizing the surface area of the electrode for electrolytic capacitors.
UV Raman Spectroscopy for Characterization of Chromium Species on Cr-MCM-41
Authors: Wang Ye , Zhang Qinghong , Guo Qian , Chen Tong , Wan Huilin , Ohishi Yoshihiko , Shishido Tetsuya , Takehira Katsuomi
Published: November 2002

UV Raman spectroscopy could distinguish the chromate species on Cr-MCM-41. Only one kind of monochromate species was observed on the Cr-MCM-41 synthesized by a direct hydrothermal synthesis method whereas several types of chromate species possibly including both monochromates and polychromates existed on that synthesized by a template-ion exchange method.
0.6–3.0 wt% of Vanadium on/in Titania Monitored by X-ray Absorption Fine Structure Combined with Fluorescence Spectrometry
Authors: Izumi Yasuo , Kiyotaki Fumitaka , Yoshitake Hideaki , Aika Ken-ichi , Sugihara Tae , Tatsumi Takashi , Tanizawa Yasuhiro , Shido Takafumi , Iwasawa Yasuhiro
Published: November 2002

Selective XAFS measurements of 0.6–3.0 wt% V sites on/in TiO2 were enabled utilizing a fluorescence spectrometer. The V sites were VIV species in the case of high-surface-area V-TiO2 in contrast to VV species in the case of conventional V/TiO2 catalysts, V supported on HSA-TiO2, and V-TiO2 prepared in the absence of dodecylamine (general sol-gel method).
Another Role of LiI/tert-Butylpyridine in Room-Temperature Molten Salt Electrolytes Containing Water for Dye-Sensitized Solar Cell
Authors: Mikoshiba Satoshi , Murai Shinji , Sumino Hiroyasu , Hayase Shuzi
Published: November 2002

High-performance dye-sensitized solar cells having nonvolatile electrolytes are desired. We found that photovoltaic performance increased when water was added into nonvolatile organic molten salts in the presence of both LiI and tert-butylpyridine. We achieved 4.2% energy-conversion efficiency for the 1 cm2 cell containing the above electrolyte (AM1.5, 100 mW/cm2) without other volatile organic solvents.
Photocatalytic Water Splitting over Spontaneously Hydrated Layered Tantalate A2SrTa2O7·nH2O (A=H, K, Rb)
Authors: Shimizu Ken-ichi , Tsuji Yoshihiro , Kawakami Masato , Toda Kenji , Kodama Tatsuya , Sato Mineo , Kitayama Yoshie
Published: November 2002

A series of layered perovskite-type tantalates with hydrated interlayer space, A2SrTa2O7·nH2O (A=H, K, Rb), exhibited efficient photocatalytic activity for water splitting into H2/O2 mixture under UV irradiation without loading metal co-catalysts.
Effect of middle-ear effusion on otoacoustic emissions
Authors: Yeo Sang W. , Park Shi-Nae , Park Yong Soo , Suh Byung Do
Published: November 2002

Because otoacoustic emissions (OAEs) are transmitted from the cochlea to the ear canal via the middle ear, the transmission properties of the middle ear directly influence OAEs’ characteristics. In general, middle-ear effusion (MEE) reduces measured emission amplitudes and sometimes eliminates the response entirely. The purpose of this study was to establish the relationship between the conduction of the middle ear and OAEs’ properties and to elucidate the effect of middle-ear effusion on detecting OAEs’. Spontaneous otoacoustic emissions (SOAEs), transiently evoked otoacoustic emissions (TEOAEs) and distortion product otoacoustic emissions (DPOAEs) were recorded from 44 normal ears and 32 ears with middle-ear effusion. DPOAEs were collected in two basic forms consisting of distortion product audiograms (DP grams) and input-output (I-O) functions, elicited by two primary tones F1 and F2 and varying geometric mean frequencies between 1–6 kHz. The results of air and bone conduction hearing levels in pure tone audiogram were also analysed. In 21 ears out of 32 otitis media with effusion (OME) ears, SOAEs were absent. In the 28 ears with middle-ear effusion, the response and wave reproducibility were diminished, and in the 17 ears with middle-ear effusion, the DP gram was diminished or eliminated. In particular, I-O function curves at 3 kH and 4 kHz were diminished by the primary tones of 45 and 55 dB under the condition of MEE. The SOAEs, TEOAEs and DPOAEs (DP gram and I-O function curve) are highly reliable and useful tests for monitoring changes in middle-ear condition in children with OME and in predicting the course of OME.
Magnetic resonance imaging versus computed tomography in pre-operative evaluation of cochlear implant candidates with congenital hearing loss
Authors: Sennaroglu Levent , Saatci Isil , Aralasmak Ayse , Gursel Bulent , Turan Ergin
Published: November 2002

Recent reports indicate that the cochlear nerve may be absent in some cases of congenital sensorineural hearing loss. The aim of this prospective study was to determine the incidence of cochlear nerve anomaly in cochlear implant candidates with congenital hearing loss using magnetic resonance imaging (MRI). Twenty-seven patients with congenital profound bilateral sensorineural hearing loss who were being evaluated for the cochlear implant procedure were studied.

These patients had high-resolution computerized tomography (CT), through the petrous bone in axial sections. MRI examinations consisted of T1 and turbo spin echo (TSE) T2-weighted 3 mm axial images, and additional 3D Fourier Transform T2-weighted TSE sequences obtained on three different planes (axial, perpendicular and parallel to the internal auditory canal (IAC) i.e. oblique sagittal and coronal, respectively) for the purpose of cochlear nerve demonstration. Results showed that all of the 14 patients with normal CT of the temporal bone, had four distinct nerves in the distal part of the IAC on TSE-MRI. Thirteen patients demonstrated various bony malformations of the cochleovestibular system on CT. MRI revealed the absence of the cochleovestibular nerve in four patients where the IAC was very narrow or completely absent on CT. One patient with severe Mondini malformation who had an enlarged IAC demonstrated an isolated absent cochlear nerve.
A novel treatment for patients with hereditary haemorrhagic telangiectasia
Authors: Farnan T. B. , Gallagher G. , Scally C. M.
Published: November 2002

Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterized by dermal, mucosal, and visceral telangiectases as well as pulmonary and cerebral arteriovenous malformations. Recurrent epistaxis occurs in the majority of patients, and by the very nature of the thin walled vessels involved it is often refractory to conventional forms of treatment. We present the case of an 82-year-old lady with intractable epistaxis secondary to HHT, that was successfully controlled by the application of fibrin glue.
Spontaneous retro- and parapharyngeal haematoma caused by intrathyroid bleed
Authors: Paleri Vinidh , Maroju Raja S. , Ali Mahmoud S. , Ruckley Robert W.
Published: November 2002

A case of spontaneous haemorrhage into the retropharyngeal and parapharyngeal space secondary to bleeding from a thyroid cyst is described. While many conditions are known to cause this entity, no previous papers have reported a thyroid cyst to cause such extensive haemorrhage. Haemorrhage in these spaces is of particular importance as it causes rapid airway compromise and can be life-threatening. Forty cases of non-traumatic retropharyngeal and parapharyngeal haematomas have been reported in the literature to date. Although the diagnosis can be easily established in most patients, no published review of this condition exists. This paper reviews all reports of non-traumatic retropharyngeal and parapharyngeal haematoma published in the literature to date and discusses management guidelines. We also present here for the first time the demographics and treatment results of this rare entity.
Parotid calcification in systemic lupus erythematosis
Authors: Hopkins C. , Kanegaonkar R. , Chevretton E. B.
Published: November 2002

Calcinosis universalis is an unusual complication of systemic lupus erythematosis (SLE). We describe the case of a 22-year-old patient diagnosed with SLE during childhood, who developed a previously unreported complication of parotid calcification. Medical treatment of calcinosis is often ineffective, whereas surgical intervention completely relieved the patient’s symptoms.
Coexistence of benign schwannoma and lymphoma in a nasal polyp
Authors: Yaqoob Nausheen , Soomro Irshad , Moatter Tariq , Zaffar Abbas
Published: November 2002

The existence of a combined benign schwannoma and lymphoma presenting as a nasal polyp has not been described in the English literature. We are reporting this rare combination in a 50-year-old male whose presenting symptoms were nasal obstruction, nasal deformity and headache. Examination of the left nasal cavity revealed a mass which was confined to the nose on computed tomography (CT) scan examination. Histopathology of the mass revealed a major component to be a benign schwannoma and a minor component a large B-cell lymphoma.
Noisefield of Underexpanded Notched Circular-Slot Jets
Authors: Verma S.B. , Rathakrishnan E.
Published: November 2002

The effect of notches on the flow and noise field of jets from circular-slots is experimentally investigated. Three types of slot geometries, namely, semicircular, triangular and square are studied. The results demonstrate that the presence of the notch introduces a slight aspect-ratio in the initial circular-slot geometry so that the notched jet exhibits characteristics, similar to jets exiting from non-circular geometries. At underexpanded condition, additional expansion and compression waves are observed to emanate from the region of notches that modifies the jet development and results in a reduction in the average shock-cell length, which is accompanied by a reduction in far-field shock associated noise. The acoustic spectrum of the radiated shock noise indicates that notch geometry variation strongly alters the acoustic emission characteristics of these jets both in the screech component and broadband shock associated noise.
The Mechanisms of Passive Ear Defenders
Authors: Paurobally M. R. , Pan J.
Published: November 2002

In this paper a model of the sound transmission characteristics of a conventional circumaural passive ear protector is presented for low frequency noise. It includes the effects of porous sound absorption material within the device as well as sound leakage. A theoretical study based on the model shows that the presence of sound absorption material effectively acts to increase the volume compliance of the system, thus decreasing its resonance frequency. The role of leakage on the other hand is mainly to shift the resonance to a higher frequency depending on the equivalent leakage diameter. Experimental results are provided in support of the theoretical predictions. The model is useful in providing an understanding of the mechanisms of conventional passive ear defenders and can be employed to guide their design. The modelling can also be extended to study and aid in the development of communication and active noise control ear protectors.
Effects of female presence on intrasexual aggression in male lizards, Podarcis hispanicus
Authors: López Pilar , Martín José
Published: November 2002

Resource value and expected gain in reproduction may affect motivation to fight and the likelihood of winning. Previous experiments have showed that males increase their fighting effort when defending a territory that contains females. However, we hypothesized that for an intruding lizard, the value of a new territory may be lower if he already has a female in his own territory, and consequently, aggressivity should be lesser than if he has no access to any female. We staged encounters between males of the lizard Podarcis hispanicus in outdoor terraria to analyze the outcome and detailed behaviors involved in agonistic interactions in the presence or absence of a female in the terraria of resident and intruders. Our results showed that when a female was present, the level of aggressivity of the resident male was higher; the probability of winning the contest also increased, but only if the intruding male had no females in his own terraria. In contrast, when the intruding male was also the owner of another territory containing a female, residents were less aggressive. We suggest that the lack of information on the reproductive state of an unfamiliar female may be enough to decrease fighting motivation of an intruding male, if he has more expectations of success with his own familiar female. We conclude that differences in expected reproductive success with different females may help to decide the outcome of conflicts between males quicker and cheaper. Aggr. Behav. 28:491–498, 2002. © 2002 Wiley‐Liss, Inc.
SCL‐90‐R profiles in a sample of severely violent psychiatric inpatients
Authors: Bjørkly Stål
Published: November 2002

A sample of 39 patients who had committed serious violent acts toward others were assessed with the revised Symptom Checklist (SCL‐90‐R). The SCL‐90‐R is a self‐report symptom inventory for the measurement of psychopathology in psychiatric and medical patients. In addition to the patients' self‐report, an observer‐rated SCL‐90‐R was obtained. This was accomplished by letting one pair of nurses complete SCL‐90‐R ratings for each patient. The first aim of the study was to compare the SCL‐90‐R self‐report scores of the patient sample with the psychiatric inpatient norms [Derogatis LR (1992): Clinical Psychometric Research Inc]. Another purpose of this study was to explore possible trends of discordance between the observer ratings and the self‐reports of the study group. Always considering the limitations of the small sample, it was nevertheless also of interest to look for possible sex differences and differences between violent subgroups and between diagnostic groups in the self‐reported scores as well as in the observer ratings. The most striking findings of the present study were that the self‐reported scores were lower than the inpatient norms for SCL‐90‐R and that the patients' self‐reported levels of distress were significantly lower than those found in the observer ratings. Underreporting of psychopathology as a marker of violence risk is discussed in light of these findings. In this study, women reported higher distress levels than men in the Interpersonal Sensitivity symptom dimension. There were no significant differences concerning SCL‐90‐R ratings between patients who had committed homicide, attempted homicide, or physically assaulted another person in a serious but not life‐threatening way. Aggr. Behav. 28:446–457, 2002. © 2002 Wiley‐Liss, Inc.
Unjustified aggression in preschool
Authors: Monks C. , Ortega Ruiz R. , Torrado Val E.
Published: November 2002

This study investigates the nature of unjustified aggression in Spanish preschool children aged 4 to 6 years. Children were assigned to roles in aggression (Aggressor, Victim, Defender, Supporter, and Bystander) on the basis of peer, teacher, and self‐nominations. The roles taken in aggression were examined in relation to individuals' physical strength, social status, and social development. The coping strategies used by victims were also examined. Aggressive children were found to be socially rejected. Defenders were found to be the most popular children in the class, which may place them better to defend others without fear of reprisal or they may gain their status from the act of defending others. The findings also indicate that young victims do not exhibit the characteristics of older victims (e.g., social rejection and physical weakness), which confirms findings with 4‐ to 6‐year‐olds in England [Monks et al. 2002a, 2002b]. It is suggested that these findings relate to the instability of victimisation at this age. Aggr. Behav. 28:458–476, 2002. © 2002 Wiley‐Liss, Inc.
Differences between experience of anger and readiness to angry action: A study of Japanese and Spanish students
Authors: J. Martin Ramírez , Carmen Santisteban , Takehiro Fujihara , Stephanie Van Goozen
Published: November 2002

In this study, the individual proneness to anger, either as an experienced emotion or as action readiness, was studied in university students of both sexes in Japan and Spain, administering the Anger Situation Questionnaire (ASQ) to 425 subjects (195 in Japan and 230 in Spain). The feelings of anger experience were higher than the readiness to action in all the samples. This difference between both variables was higher in females than in males, as well as in the Spanish sample compared with the Japanese one. An intragroup analysis in each sex in each country showed that the relative differences between males and females were similar in both countries. These constant differences between both sexes seem to be independent of the cultural context. Aggr. Behav. 28:429–438, 2002. © 2002 Wiley‐Liss, Inc.
An investigation of the correlations between aggression, impulsiveness, social problem‐solving, and alcohol use
Authors: McMurran Mary , Blair Marie , Egan Vincent
Published: November 2002

Impulsivity has been shown to predict aggression and heavy drinking in males, and poor social problem‐solving has been identified as a potential mediating variable in this relationship. We set out to investigate the inter‐relationships among impulsiveness, social problem‐solving, aggression, and alcohol use in a non‐offender sample of British males (N=70). Of our proposed relationships, only two were significant: higher impulsivity was related to poorer social problem‐solving, and poorer social problem‐solving was related to greater aggression. Combining impulsivity and social problem‐solving indicated that poor social problem‐solving, not impulsivity, was what exerted the influence over aggression in this sample. Impulsivity perhaps presents an obstacle to learning in the early developmental years, and the legacy of poor problem‐solving is what later contributes to aggression. Aggr. Behav. 28:439–445, 2002. © 2002 Wiley‐Liss, Inc.
Studies of biologically potent organotin(IV) and organosilicon(IV) complexes of a sulfur donor ligand derived from 1‐acetylferrocene
Authors: Singh R. V. , Joshi S. C. , Gajraj Anita , Nagpal Pooja
Published: November 2002

The coordination and organometallic chemistry of metal–nitrogen‐ and metal–sulfur‐bonded compounds have come to occupy a prominent position in research due to their economical importance in the field of agricultural, medicinal and industrial chemistry. Although Schiff bases of ferrocene derivatives and their metal complexes with lanthanide and transition metal ions have been synthesized and some of their structures characterized, their interaction with main group metal ions and the formation of their coordination complexes are subjects of current interest. This communication deals with a description of synthetic procedure and structural characterization on the basis of analytical and spectroscopic techniques of a new class of coordination compounds of organotin(IV) and organosilicon(IV) with a sulfur‐containing ligand moiety derived by the condensation of 1‐acetylferrocene and thiosemicarbazide. Finally, attempts have been made to establish a correlation between a variety of biointeraction activities, including antimicrobial activity and antifertility activity, on male rats and the structures of the resulting products on the basis of different constituents and chemical phenomena. Copyright © 2002 John Wiley & Sons, Ltd.
Granule changes of human and murine endocrine cells in the gastrointestinal epithelia are characteristic of piecemeal degranulation
Authors: Crivellato Enrico , Ribatti Domenico , Mallardi Franco , Beltrami Carlo Alberto
Published: November 2002

Piecemeal degranulation is a unique pattern of cell secretion that consists of a slow release of granule contents from cytoplasmic secretory granules, which leaves empty chambers that do not fuse with each other or with the plasma membrane. To our knowledge, no cell types other than mast cells, basophils, and eosinophils have been reported in the literature to show morphological features of piecemeal degranulation. In the present study we provide evidence for ultrastructural morphologies characteristic of piecemeal degranulation in entero‐endocrine cells of the human and murine gastrointestinal epithelia. Human biopsy samples were taken from the mucosa of the distal duodenum, proximal jejunum, and colon in 10 patients undergoing endoscopic examination for malabsorption, diarrhea, and/or abdominal pain. Murine gastrointestinal samples were obtained from 10 adult C57 mice. All specimens were prepared for transmission electron microscopy (TEM) according to standard protocols. Results showed that different types of gastrointestinal entero‐endocrine cells, in both humans and mice, were recognizable with ultrastructural features diagnostic for piecemeal degranulation, including specific granule and cytoplasmic changes. In the granules, the content was found to be loosely packed or diminished. Notably, altered granules did not fuse with each other or with the plasma membrane, and were characteristically intermingled with normal, resting granules. At times, the release events transformed the granules into enlarged, empty containers. Numerous entero‐endocrine cells presented a rich supply of membrane‐bound vesicles (50–200 nm in diameter) that were free in the cytoplasm or attached to granules. This finding of piecemeal degranulation in gastrointestinal entero‐endocrine cells suggests that such a secretory model might be a general degranulation pattern in cells involved in paracrine‐endocrine secretion. Anat Rec 268:353–359, 2002. © 2002 Wiley‐Liss, Inc.
Selective blockade of astrocytic glutamate transporter GLT‐1 with dihydrokainate prevents neuronal death during ouabain treatment of astrocyte/neuron cocultures
Authors: Kawahara Koichi , Hosoya Rui , Sato Hideomi , Tanaka Motoki , Nakajima Takayuki , Iwabuchi Sadahiro
Published: November 2002

Glutamate (Glu) is a major excitatory neurotransmitter of the mammalian central nervous system and under normal conditions plays an important role in information processing in the brain. Therefore, extracellular Glu is subject to strong homeostasis. Astrocytes in the brain have been considered to be mainly responsible for the clearance of extracellular Glu. In this study, using mixed neuron/astrocyte cultures, we investigated whether astrocytic Glu transporter GLT‐1 is crucial to the survival of neurons under various conditions. Treatment of the mixed cultures with a low concentration of Glu did not produce significant death of neurons. However, cotreatment with dihydrokainate (DHK), a specific blocker of GLT‐1, resulted in significant neuronal death that was suppressed by an antagonist of N‐methyl‐D‐aspartate (NMDA) receptors. These results suggested that astrocytic GLT‐1 participated in the clearance of extracellular Glu and protected neurons from NMDA receptor‐mediated toxicity. When the cultures were treated with ouabain, an inhibitor of Na+/K+‐ATPase, a low concentration of Glu resulted in massive neuronal death that was also suppressed by cotreatment with an antagonist of NMDA receptors. In this case, however, cotreatment with DHK significantly protected neurons from death, suggesting that GLT‐1 was responsible for the death of neurons. The present study provides evidence suggesting that astrocytes use their Glu transporter GLT‐1 to protect neurons from Glu toxicity, but, ironically, also use GLT‐1 to kill neurons through Glu toxicity depending on their status. GLIA 40:337–349, 2002. © 2002 Wiley‐Liss, Inc.
Optimizing the tensile properties of polyvinyl alcohol hydrogel for the construction of a bioprosthetic heart valve stent
Authors: Wan W. K. , Campbell G. , Zhang Z. F. , Hui A. J. , Boughner D. R.
Published: November 2002

Although bioprosthetic heart valves offer the benefits of a natural opening and closing, better hemodynamics, and avoidance of life‐long anticoagulant therapy, they nevertheless tend to fail in 10–15 years from tears and calcification. Several authors, including the present ones, have identified the rigid stent as a factor contributing to these failures. The ultimate solution is an artificial heart valve that has mechanical properties that allow it to move in conformity with the aortic root during the cardiac cycle, has superior hemodynamics, is nonthrombogenic, will last more than 20 years, and mitigates the need for anticoagulants. We have identified a polymer, polyvinyl alcohol (PVA) hydrogel, that has mechanical properties similar to soft tissue. The purpose of this research is to match the tensile properties of PVA to the porcine aortic root and to fabricate a stent prototype for a bioprosthetic heart valve with the use of the PVA hydrogel. Specimens of 15% w/w PVA were prepared by processing through 1–6 cycles of freezing (−20 °C) at 0.2 °C/min freeze rate and thawing (+20°C) at different thawing rates (0.2 °C/min and 1 °C/min), for different holding times (1 and 6 h) at −20 °C. Subsequently tensile tests and stress‐relaxation tests were conducted on the specimens. The different holding times at −20 °C demonstrated no difference in the result. The slower thawing rate improved the tensile properties but did not produce significant changes on the stress‐relaxation properties. The nonlinear stress–strain curve for the PVA after the fourth freeze–thaw cycle matched the porcine aortic root within the physiological pressure range. The stress‐relaxation curve for PVA also approximated the shape of the aortic root. The complex geometry of an artificial heart valve stent was successfully injection molded. These results, in combination with other preliminary findings for biocompatibility and fatigue behavior, suggest that PVA hydrogel is a promising biomaterial for implants, catheters, and artificial skin. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 854–861, 2002
Heparin release from slippery‐when‐wet guide wires for intravascular use
Authors: Peerlings Camiel C. L. , Hanssen Hans H. L. , Bevers Raymond T. J. , Boelen Erik J. H. , Stelt Bram J. , Korthagen Eva J. M. , Koole Leo H.
Published: November 2002

Thin metallic wires with an adherent hydrophilic/ lubricious polymeric coating were manufactured in a new extrusion‐like procedure. This procedure is part of a novel and efficient way of assembling lubricious guide wires for intravascular interventions, such as percutaneous transluminal angioplasty. It is reported that heparin can readily be incorporated in the hydrophilic coating. A set of heparin‐containing guidewire models was made and studied in detail. This showed that (i) immersion of the guide‐wire models in an aqueous environment leads to release of heparin from their surface; (ii) the presence of heparin in the coating does not impede the lubricity of the coils; (iii) addition of stearic acid in the coating, next to heparin, does not influence the lubricity of the guide‐wire models. Two different charges of heparin (designated heparin‐low and heparin‐high) were incorporated in the coating. It is discussed that release of heparin from the surface of medical devices (e.g. guide wires and catheters) is much more effective than systemic heparinization, basically because dissolved heparin molecules have a much larger probability of simply passing a medical device's surface (axial convection) rather than contacting it (radial diffusion). © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 692–698, 2002