bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural changes during oxidation of Au(110)
Authors: Hale Penny , Thurgate Stephen , Wilkie Peter
Published: September 2002

The gold(110) single crystal exhibits a (1 × 2) surface structure when clean, but when immersed in 0.01 M HClO4 under potential control the structure has been found to change. Throughout the double‐layer region the structure remains as (1 × 2) but when the potential is increased above 0.9–1.0 V vs. Ag/AgCl (the pre‐oxidation region) the surface structure changes to a centred rectangular structure. This structure forms reproducibly but has limited stability. After the initial oxidation, the structure prevails until 1.2–1.3 V, whereupon oxidation occurs on a larger scale and the surface structure becomes (1 × 1). These structures return to (1 × 2) after reduction of the oxide, proving that the structural changes are reversible. X‐ray photoelectron spectroscopy of these regions has shown a difference in the chemical state of the oxygen. Adsorbed perchlorate ion is initially the only oxygen component but as the potential increases the peak shifts into the hydroxide region and finally splits into a hydroxide peak and a metal oxide peak. This study indicates a new way of looking at the structure and composition of the gold surface and provides insight into the nature of the interaction between the surface and the solution. Copyright © 2001 John Wiley & Sons, Ltd.
Plasma modification of PTFE surfaces. Part I: Surfaces immediately following plasma treatment
Authors: Wilson D. J. , Williams R. L. , Pond R. C.
Published: September 2002

Polytetrafluoroethylene (PTFE) was treated in a low‐power plasma using a series of feed gases (O2, Ar, N2 and NH3) and the resulting surface modifications were evaluated by x‐ray photoelectron spectroscopy, static secondary ion mass spectroscopy, dynamic contact angle measurements and atomic force microscopy. All plasma treatments caused light etching, but the nature and extent of chemical modification varied considerably. Fluorine depletion of the surface was affected most efficiently by Ar and least effectively by O2 plasma. New functionalities were introduced to the surface either from plasma derivatives of the feed gases or by post‐treatment exposure to moist air; Ar, N2 and NH3 were more effective than O2 in this respect. The wettability of virgin and plasma‐treated materials in phosphate‐buffered saline solution (PBS) and 1‐bromonaphthalene was studied, and the observations are discussed in a framework that correlates contact‐angle hysteresis with surface chemistry in a semi‐quantitative manner. In Part II of this work, further changes of the surface chemistry and wettability of virgin and plasma‐treated materials arising due to storage in PBS or air are described. Copyright © 2001 John Wiley & Sons, Ltd.
On the cultural validity of science assessments
Authors: Solano‐Flores Guillermo , Nelson‐Barber Sharon
Published: September 2002

We propose the concept of cultural validity as a form of test validity in science assessment. The conceptual relevance of cultural validity is supported by evidence that culture and society shape an individual's mind and thinking. To attain cultural validity, the process of assessment development must consider how the sociocultural context in which students live influences the ways in which they make sense of science items and the ways in which they solve them. These sociocultural influences include the values, beliefs, experiences, communication patterns, teaching and learning styles, and epistemologies inherent in the students' cultural backgrounds, as well as the socioeconomic conditions prevailing in their cultural groups. We contend that current approaches to handling student diversity in assessment (e.g., adapting or translating tests, providing assessment accommodations, estimating test cultural bias) are limited and lack sociocultural perspective. We find that attaining cultural validity may conflict with current basic principles and assumptions in testing, such as item independence and standardization. We discuss the ways in which adopting cultural validity as a criterion for test validity makes it necessary to shift assessment paradigms and adopt new procedures for assessment development. © 2001 John Wiley & Sons, Inc. J Res Sci Teach 38: 553–573, 2001
Interactions of histamine and bradykinin on polymodal C‐fibres in isolated rat skin
Authors: Koppert Wolfgang , Martus Peter , Reeh Peter W.
Published: September 2002

Patients suffering from pruritus due to atopic dermatitis show, in asymptomatic skin, reduced itch and flare responses to histamine, the major pruritogenic mediator. We hypothesized that this apparent loss in histamine sensitivity may be overcompensated in inflamed skin and investigated the interactions between histamine and bradykinin, the major inflammatory mediator.

The studies were performed using the isolated rat skin–nerve preparation. Forty‐two fibres were tested following four different experimental protocols. After characterization of the sensory properties, six fibres were treated repetitively with histamine (HIS1, HIS2) to exclude the possibility that the responses (spikes/min) increase simply by repetition. In 12 other units, histamine (HIS1) was followed by a wash‐out period prior to bradykinin (BK) stimulation; in another 12 units, BK followed immediately after HIS1. A further 12 fibres were examined without preceding heat stimulation in order to avoid possible sensitization.

If BK was administered after a wash‐out period following HIS1, the BK responses were significantly higher than the HIS1 response. The BK response showed a peak discharge which was absent if BK followed directly upon HIS1. If HIS2 was applied directly following BK, the induced discharge was significantly larger than the first histamine response and not different from the BK response, whereas a washout period before HIS2 abolished the sensitizing effect of previous BK.

A unidirectional sensitization by previous bradykinin or heat stimulation on the histamine responsiveness of polymodal nociceptors has been demonstrated. If ‘itch fibres’ in humans were subject to similar interactions of histamine with inflammatory mediators, this may compensate for a down‐regulation of histamine receptors in eczematic skin and possibly account for the pruritus.
Backward and forward Blocking in Human Electrodermal Conditioning: Blocking Requires an Assumption of Outcome Additivity
Authors: Mitchell Chris J. , Lovibond Peter F.
Published: September 2002

Blocking was observed in two human Pavlovian conditioning studies in which colour cues signalled shock. Both forward (Experiment 1) and backward (Experiment 2) blocking was demonstrated, but only when prior verbal and written instructions suggested that if two signals of shock (A+ and B+) were presented together, a double shock would result (AB++). In this case, participants could assume that the outcome magnitude was additive. Participants given non-additivity instructions (A+ and B+ combined would result in the same outcome, a single shock) failed to show blocking. Modifications required for associative models of learning, and normative statistical accounts of causal induction, to account for the impact of additivity instructions on the blocking effect, are discussed. It is argued that the blocking shown in the present experiments resulted from the operation, not of an error-correction learning rule, nor of a simple contingency detection mechanism, but of a more complex inferential process based on propositional knowledge. Consistent with the present data, blocking is a logical outcome of an A+/AB+ design only if participants can assume that outcomes will be additive.
Preparation and microstructure characterization of ball-milled ZrO2powder by the Rietveld method: monoclinic to cubic phase transformation without any additive
Authors: Bid S. , Pradhan S. K.
Published: September 2002

The phase transformation kinetics of high-energy ball-milled monoclinic ZrO2have been studied in detail by Rietveld powder structure refinement analysis. In the present study, no stabilizing compound was required to obtain the cubic phase. The fine-grain powder was milled in a planetary ball mill for up to several hours at different BPMRs (ball to powder mass ratios): 10:1, 20:1, 35:1 and 40:1. During the process of ball milling, the monoclinic phase is gradually transformed to the cubic phase. The relative phase abundances of the respective phases, the particle sizes, the r.m.s. strains, the lattice parameter changes,etc., have been estimated from Rietveld analysis of X-ray powder diffraction data. It has been found that a higher BPMR exerts more influence on rapid phase transformation. In them- toc-ZrO2phase transformation, no formation of an intermediate tetragonal ZrO2phase has been found. The small change in the lattice volume ofm-ZrO2, which is very close to the lattice volume ofc-ZrO2, caused by ball milling may be attributed to this phase change. The formation of thecphase is noticed, in general, after just 1 h of ball milling, and the particle size of themphase is reduced to a large extent at the first stage of milling and remains almost unchanged with increasing milling time. However, the particle size of thecphase increases with increasing milling time for the samples milled with higher BPMRs (35:1 and 40:1), suggesting that quenching caused by a high impact energy followed by an annealing effect may play a vital role, which is further manifested in the agglomeration of small particles.
Simple optics to decrease beam divergence and improve energy resolution for laboratory X-ray sources
Authors: Kunz Martin , Pattison Philip , Reifler Hans
Published: September 2002

A combination of very simple and well known optical elements is presented, which allows characteristics such as monochromaticity and angular divergence of a sealed-tube Mo X-ray beam to be improved, while maintaining adequate intensity for high-pressure measurements of unit-cell volumes. This improvement is aimed at optimizing measurements of lattice compressibility by means of single-crystal diffraction, as commonly carried out in mineral physics. The experimental arrangement consists of an asymmetrically cut Ge(111) monochromator, a pair of Cr-coated mirrors and a simple blade to cut off theKα2contribution. Tests with a ruby standard crystal show a decrease in the widths of the diffraction peaks by a factor of three and an improvement in the accuracy of the unit-cell volume determination by at least a factor of three, while maintaining sufficient intensity in the diffracted beam.
The PRIDE server for protein three-dimensional similarity
Authors: Vlahovicek Kristian , Carugo Oliviero , Pongor Sándor
Published: September 2002

The PRIDE server is an implementation of thePRIDEalgorithm that compares protein three-dimensional structures in terms of their Cαdistance distributions. In response to queries presented as single or concatenated Protein Data Bank (PDB) files, the server can carry out (i) a pairwise comparison of two protein three-dimensional structures, (ii) a structural clustering of protein three-dimensional structures, providing a distance matrix and a dendrogram as an output; and (iii) a similarity search with a protein domain structure query against the CATH database.
Market orientation and dimensions of strategic orientation
Authors: Morgan Robert E. , Strong Carolyn A.
Published: September 2002

The specific domain of market orientation has been the subject of much scrutiny this decade. Both conceptual and empirical advances have been made to establish the marketing orientation construct as central to marketing decisions, business activities and organizational culture. However, a lacuna remains in understanding how market orientation may be related to competitive strategy. It is argued that market oriented activities and behaviours are articulated through strategic means which guides the firm in its product‐market. Conceptualized as “strategic orientation of the business enterprise”, competitive strategy is discussed as an important vehicle through which market orientation may be manifest. Six dimensions of strategic orientation are presented and statistical analyses, of data generated from a survey of medium and large industrial manufacturing businesses, specified “proactiveness”, “analysis” and “futurity” as positive and significant in their association with firms’ levels of market orientation. Discussion of these findings is made, along with various conclusions and implications of the study for executive and academic audiences.
Sunny walls vs sunnier roofs
Authors: Stasinopoulos Thanos N.
Published: September 2002

This study focuses on the widely accepted principle that the equatorial sides of a building offer the optimum solar potential for solar space heating. A comparison between the solar irradiation on the south walls and horizontal roofs of buildings in London and Athens highlights the energy benefits of facing the sky rather than the equator. Four building examples exemplify practical ways to utilize the rather neglected potential of roofs as solar collectors for space heating.
CHAOS FOR BACKWARD SHIFT OPERATORS
Authors: MARTÍNEZ-GIMÉNEZ F. , PERIS A.
Published: September 2002

Backward shift operators provide a general class of linear dynamical systems on infinite dimensional spaces. Despite linearity, chaos is a phenomenon that occurs within this context. In this paper we give characterizations for chaos in the sense of Auslander and Yorke [1980] and in the sense of Devaney [1989] of weighted backward shift operators and perturbations of the identity by backward shifts on a wide class of sequence spaces. We cover and unify a rich variety of known examples in different branches of applied mathematics. Moreover, we give new examples of chaotic backward shift operators. In particular we prove that the differential operator I + D is Auslander–Yorke chaotic on the most usual spaces of analytic functions.
DELAYED FEEDBACK CONTROL OF CHAOTIC SYSTEMS WITH DRY FRICTION
Authors: GALVANETTO UGO
Published: September 2002

This paper describes some numerical techniques to control unstable periodic orbits embedded in chaotic attractors of a particular discontinuous mechanical system. The control method is a continuous time delayed feedback that modifies the stability of the orbit but does not affect the orbit itself.
Overexpression of Thioredoxin-1 in Transgenic Mice Attenuates Adriamycin-Induced Cardiotoxicity
Authors: Shioji Keisuke , Kishimoto Chiharu , Nakamura Hajime , Masutani Hiroshi , Yuan Zuyi , Oka Shin-ichi , Yodoi Junji
Published: September 2002

Background—

Adriamycin (ADR) is an anticancer drug known to cause severe cardiac toxicity by generating free radicals. We investigated the role of a redox-regulating molecule, thioredoxin-1 (TRX1), in ADR-induced cardiotoxicity.

Methods and Results—

The in vitro study showed that TRX1 was dose-dependently increased concomitant with the formation of hydroxyl radicals in ADR-treated neonatal rat cardiomyocytes. Lactate dehydrogenase–releasing assay showed that treatment with recombinant human TRX1 suppressed cardiomyocyte injury in ADR-treated cardiomyocytes. To examine the biological significance of TRX1 in vivo, we used transgenic mice expressing increased levels of human TRX1 (TRX1-TG mice). Electron microscopy revealed that mitochondria, myofibrils, and other cellular details were much better maintained in ADR-treated TRX1-TG mice than in ADR-treated nontransgenic (WT) mice. The increase in the protein carbonyl content, a marker of cellular protein oxidation, was suppressed in ADR-treated TRX1-TG mice compared with ADR-treated WT mice. The formation of hydroxyl radicals in ADR-treated heart homogenates of TRX1-TG mice was decreased compared with WT mice. For the survival study, all WT mice treated with ADR died within 6 weeks, but 5 of 6 TRX1-TG mice treated with ADR survived >8 weeks.

Conclusions—

TRX1 is upregulated by intracellular oxidative stress generated by ADR. TRX1 has a protective role against ADR-induced cardiotoxicity by reducing oxidative stress.
Progressive Aortic Root Dilatation in Adults Late After Repair of Tetralogy of Fallot
Authors: Niwa Koichiro , Siu Samuel C. , Webb Gary D. , Gatzoulis Michael A.
Published: September 2002

Background—

Aortic valve or aortic root (AoRo) replacement is occasionally required because of AoRo dilatation and aortic regurgitation (AR) in repaired tetralogy of Fallot (TOF). We evaluated AoRo size and possible factors associated with its dynamic nature in adults with repaired TOF.

Methods and Results—

Of 216 patients with TOF repair who underwent echocardiography in 1997, we identified 32 patients (mean age, 36±8.0 years) with AoRo dilatation, defined as ratio of observed to expected AoRo size by standard nomogram >1.5 (group A), and 54 TOF controls, matched for age with AoRo ratio <1.5 (group B), who underwent at least 1 previous echocardiogram in the preceding 10 years. Mean indexed AoRo size (cm/m
2
) in 1997 was 2.5±0.5 in group A and 1.7±0.2 in group B (
P
<0.0001). AoRo rate of change (mm/year) from the first to 1997 study (mean interval, 5.2±3.8 years) was 1.7±3.8 in group A and 0.03±1.6 in group B (
P
=0.001). Patients from group A had a longer shunt-to-repair interval (
P
=0.048) with a higher prevalence of pulmonary atresia (
P
<0.0001), right aortic arch (
P
=0.03), moderate to severe AR (
P
=0.002), aortic valve replacement (
P
=0.02), larger cardiothoracic ratio (
P
=0.02), and increased left ventricular end-diastolic dimensions (
P
=0.002).

Conclusions—

A subset of adult TOF exhibits ongoing dilatation of AoRo late after repair. This dilatation relates to previous long-standing volume overload of AoRo and possibly to intrinsic properties of AoRo and may lead to AR. Meticulous follow-up of AoRo after TOF repair is recommended.
Coronary Sinus-Ventricular Accessory Connections Producing Posteroseptal and Left Posterior Accessory Pathways
Authors: Sun Yingxian , Arruda Mauricio , Otomo Kenichiro , Beckman Karen , Nakagawa Hiroshi , Calame James , Po Sunny , Spector Peter , Lustgarten Daniel , Herring Lisa , Lazzara Ralph , Jackman Warren
Published: September 2002

Background—

The coronary sinus (CS) has a myocardial coat (CSMC) with extensive connections to the left and right atria. We postulated that some posteroseptal and left posterior accessory pathways (CSAPs) result from connections between a cuff of CSMC extending along the middle cardiac vein (MCV) or posterior coronary vein (PCV) and the ventricle. The purpose of the present study was to use CS angiography and mapping to define and determine the incidence of CSAPs and determine the relationship to CS anatomy.

Methods and Results—

CSAP was defined by accessory pathway (AP) potential or earliest activation in the MCV or PCV and late activation at anular endocardial sites. A CSAP was identified in 171 of 480 patients undergoing ablation of a posteroseptal or left posterior AP. CS angiography revealed a CS diverticulum in 36 (21%) and fusiform or bulbous enlargement of the small cardiac vein, MCV, or CS in 15 (9%) patients. The remaining 120 (70%) patients had an angiographically normal CS. A CSMC extension potential (CSE), like an AP potential, was recorded in the MCV in 98 (82%), in the PCV in 13 (11%), in both the MCV and PCV in 6 (5%), and in the CS in 3 (2%) of 120 patients. CSMC potentials were recorded between the timing of atrial and CSE potentials.

Conclusions—

CSAPs result from a connection between a CSMC extension (along the MCV or PCV) and the ventricle. The CS is angiographically normal in most patients.
Ontology of Culture and the Study of Human Behavior
Authors: Pyysiäinen Ilkka
Published: September 2002

It is here argued that 'culture' is a universal in the philosophical sense of the term: it expresses a general property. It is not a singular term naming an abstract entity, but rather a singular predicate the intension of which is 'cultureness.' Popper's view of the ontology of mathematics is used as an analogous example in the light of which the ontology of culture is analyzed. Cultures do not have an independent existence (realism), they are not mere names (Nominalism), and neither do they exist as fixed entities in the mind (conceptualism). Cultures are abstractions made by the mind, which yet are not reducible to the mind. They exist in the form of certain mental operations creating a new level of reality. Scientific study of culture involves both explaining how cultural phenomena are constructed in minds and how these constructions function in cognition and communication.
Type nouns and the five factor model of personality description
Authors: HENSS RONALD
Published: September 2002

Research in the tradition of the lexical approach has been largely confined to adjective rating scales. Another word class that appears particularly suited for personality description is the class of type nouns (e.g. extravert, misanthrope, leader, coward, intellectual). This paper presents the first investigation in the factorial structure of a relatively large set of German type nouns. Stimulus persons were 12 prominent males (e.g. Boris Becker, Helmut Kohl) and 12 prominent females (e.g. Claudia Schiffer, Steffi Graf). Raters were 240 men and 240 women. Each rater judged one stimulus person on 192 unipolar type noun scales and 32 bipolar adjective scales. Factor analyses of the type nouns yielded seven factors for males and six for females. These factors represented a clear‐cut and meaningful personality structure. Comparisons with the adjective factors (seven male and six female) demonstrated that the noun factors show some resemblance to the Big Five and Physical Attractiveness. Multiple regression analyses showed that the noun factors cannot be completely reduced to the Big Five. Some systematic differences between male and female stimuli are also discussed. © 1998 John Wiley & Sons, Ltd.
Tetrabenzoporphyrins: Metal Incorporation and Exchange Kinetics,
Ligational Equilibria and Pulse Radiolysis Studies
Authors: CROMER S. , HAMBRIGHT P. , GRODKOWSKI J. , NETA P.
Published: September 2002

The solution chemistry of tetrabenzoporphyrin ( TBP ) and several of
its metal derivatives were compared with that of the corresponding
octaethylporphyrins. Kinetic studies were done on zinc and cadmium ion
incorporation and the exchange reactions of cadmium porphyrins with zinc.
Formation constants of Cd (II), Cu (II), VO (IV), Ni (II), Zn (II) and Mg
(II) porphyrins with pyridine were determined for both compounds. The
spectra of the radical cations of Ni (II), Mg (II) and H
2- TBP were obtained, as well as that of the
radical anion of Mg (II)- TBP . Aside from the new Ni (I)- TBP , no
long-lived intermediates, as noted with other porphyrins, were observed upon
reduction of the tetrabenzoporphyrins. The low basicity and rigidity of the
tetrabenzoporphyrin nucleus may explain many of its relative reactivity
properties.
Investigation of Phthalocyanine Catalysts for the Aerobic Synthesis of meso-Substituted Porphyrins
Authors: RAVIKANTH M. , ACHIM CATALINA , TYHONAS JOHN S. , MÜNCK ECKARD , LINDSEY JONATHAN S.
Published: September 2002

The aerobic oxidation process for the synthesis of porphyrins, previously performed using 5 mol % p-chloranil (TCQ), 5 mol % iron(II) phthalocyanine ( FePc ) and stoichiometric amounts of O 2, has been refined using new phthalocyanine catalysts. Four phthalocyanine catalysts have been prepared, characterized by Mössbauer spectroscopy and examined for efficacy in the high concentration (0.1 M) synthesis of tetraphenylporphyrin at room temperature. Each phthalocyanine has been identified to be a μ-oxo dimer. Two catalysts are soluble (the μ-oxo dimers [(t-butyl)4 FePc ]2 O and [(n- C 6 H 13 O )4 FePc ]2 O ) and enable homogeneous reactions, while two are insoluble (the μ-oxo(1) and μ-oxo(2) dimers of FePc , ( FePc )2 O ) and give heterogeneous reactions. These four phthalocyanine compounds provide efficient catalysis at the 0.3–1 mol % level using only 1 mol % quinone or hydroquinone ( TCQ , DDQ , TCQH 2 or DDQH 2), affording ~25% yields of tetraphenylporphyrin in 60 min of oxidation. There are no discernible advantages of the homogeneous versus heterogeneous catalysts. The μ-oxo dimers are active, but FePc is inactive, at the 0.3 mol % level. The activity of the FePc sample at the 5 mol % level is attributed to residual μ-oxo dimer impurity. This aerobic oxidation process is superior to stoichiometric oxidation with TCQ or DDQ , and can be performed in the presence of BF 3· O ( Et )2, trifluoroacetic acid, or under neutral conditions.
Photoinduced Hydrogen Evolution with Hydrogenase and Water-soluble Viologen-linked Zinc Porphyrins
Authors: AMAO YUTAKA , KAMACHI TOSHIAKI , OKURA ICHIRO
Published: September 2002

A series of water-soluble viologen-linked zinc porphyrins with different methylene chain lengths (n = 3−6) between porphyrin and viologen, ZnP ( C n V )4, were synthesized and characterized. The intra- molecular electron transfer rate constants from the porphyrin moiety of ZnP (Cn V )4 to viologen were measured by using fluorescence lifetime and laser flash photolysis. Both the photoexcited singlet state and the triplet state of the porphyrin were quenched by the bonded viologen. These compounds were applied to photoinduced hydrogen evolution in the system containing nicotinamide-adenine dinucleotide phosphate (reduced form NADPH), ZnP ( C n V )4 and hydrogenase under steady-state irradiation.
Photochemical Properties of Water-soluble Fluorinated Zinc Phthalocyanines and their Photocytotoxicity AgainstHeLaCells
Authors: FUKUSHIMA KAORU , TABATA KENJI , OKURA ICHIRO
Published: September 2002

Three types of amphiphilic water-soluble fluorinated zinc phthalocyanines are characterized. They have absorption bands at long wavelength, which cause greater penetration depth of a tissue. The uptake and photodynamic activity of the phthalocyanines against HeLa cells were measured, showing that the phthalocyanines exhibited higher photodynamic activities than zinc tetrasulfonated phthalocyanine.
Electrochemical and Adsorption Properties of Novel Phthalocyanines with Four 16-Membered Diazadithia Macrocycles
Authors: ÖZKAYA A. R. , YILMAZ İ , BEKAROǦLU Ö.
Published: September 2002

Cyclic voltammetric measurements of Cu (II) and Ni (II) phthalocyanines with four 16-membered diazadithia macrocycles (1 and 2) and pentanuclear Ni (II) phthalocyanine bearing four Cu (II) ions in diazadithia macrocycles at the peripheral positions (3) have been carried out on platinum in DMSO and in aqueous medium 3 showed strong adsorption properties in DMSO and especially in aqueous medium, possibly as a result of the interaction between the copper ions in the four macrocycles and the platinum working electrode. Interestingly, the oxidation peak of 3 was split into two waves in aqueous medium. This behaviour is discussed in terms of disaggregation of the mixed valence species produced by the oxidation of aggregated species. A mechanism for both the oxidation of the complex and the splitting of the oxidation peak into two waves is suggested.
Synthesis of a Substituted Phthalocyaninato-polysiloxane and its Langmuir-Blodgett Films
Authors: LI Y. J. , FAN Y. , REN X. G. , ZHANG L. G. , JIANG D. P. , LU A. D. , WANG S. , LEBLANC R. M.
Published: September 2002

Tetrakis-4-(2,4-di-tert-amylphenoxy)phthalocyaninato-polysiloxane was synthesized. Its molecular structure was confirmed by elemental analysis, IR and UV-vis spectra. The gas-sensitive properties of its Langmuir–Blodgett films exposed to NH3, I2and NO2in air were measured. The results showed that the detection sensitivity on exposure to NH3in air can reach 0.1 ppm, while it can reach 100 ppm on exposure to NO2and I2in air.
Liquid Secondary Ion Mass Spectrometry and Collision-induced Dissociation Mass Spectrometry of Sulfonamide Derivatives of meso-Tetraphenylporphyrin
Authors: DOMINGUES M. ROSÁRIO M. , SANTANA-MARQUES M. GRAÇA , FERRRER-CORREIA A. J. , TOMÉ AUGUSTO C. , NEVES MARIA G. P. M. S. , CAVALEIRO JOSÉ A. S.
Published: September 2002

Liquid secondary ion mass spectrometry (LSIMS) and collision-induced dissociation (CID) were used for the characterization of sulfonamide derivatives of meso-tetraphenylporphyrin (TPP). The spectra obtained using LSIMS show abundant molecular ions and fragment ions from losses of the sulfonamide moieties. The main fragmentation observed in the LSI mass spectra and in the CID spectra of the protonated or cationized molecules involves the loss of one sulfonamide group. In addition, in the CID spectra of these compounds the fragment ions formed by the elimination of two, three and/or four sulfonamide groups are also observed. The CID spectra of the protonated or cationized molecules of these derivatives do not display the ions formed by the cleavage of the S - N bond which have been reported for other sulfonamide compounds. The LSI mass spectra and CID spectra of sulfonamide derivatives of meso-tetraphenylporphyrin provide an easy and reliable means of identification of the number and nature of sulfonamide groups in the porphyrinic ring.
The Electronic and Non-linear Optical Properties of Oxo-titanium Phthalocyanines
Authors: HENARI FRYAD , DAVEY ANDREW , BLAU WERNER , HAISCH P. , HANACK M.
Published: September 2002

The valence electronic properties of some unsubstituted and peripherally substituted oxo-titanium phthalocyanines are reported. Semiempirical quantum chemical calculations show that the nature of peripheral substituents has a strong bearing on the valence electronic properties, including the state dipole moments and absorption wavelength. The non-linear optical response was measured around the the Q-band resonance. The effect of different substituents and substitution patterns on the non-linear behaviour of the samples was determined. The combined results suggest that tuning of electronic and optical properties is effectively achieved by functionalization of the edges of the conjugated ring.
Tetrakis(selenodiazole)porphyrazines 1: Tetrakis(selenodiazole)porphyrazine and its Mg(II) and Cu(II) Derivatives. Evidence for their Conversion to Tetrakis(pyrazino)porphyrazines through Octaaminoporphyrazines
Authors: BAUER ELVIRA M. , ERCOLANI CLAUDIO , GALLI PAOLA , POPKOVA IRINA A. , STUZHIN PAVEL A.
Published: September 2002

The new phthalocyanine-like macrocycle tetrakis(selenodiazole)porphyrazine, TSeDPzH 2, and its Mg ( II ) and Cu ( II ) complexes have been prepared and their general, spectroscopic (IR, UV-vis), and magnetic properties investigated. It has been observed that the peripheral selenodiazole rings of the TSeDPz skeleton can be opened by the action of H 2 S , with release of the Se atoms and formation of a new macrocycle, i.e. octaaminoporphyrazine, which is easily converted into tetrakis(pyrazino)porphyrazine derivatives.
Formation and Spectroelectrochemical Characterization of Multilayer and Submonolayer Thin Films of 2,3,9,10,16,17,23,24-Octa(2-benzyloxy-ethoxy) Phthalocyninato Copper (CuPc(OC2OBz)8)
Authors: SMOLENYAK P. E. , PETERSON R. A. , DUNPHY D. R. , MENDES S. , NEBESNY K. W. , O'BRIEN D. F. , SAAVEDRA S. S. , ARMSTRONG N. R.
Published: September 2002

We review here the self-assembly, electrochemical and spectroelectrochemical properties of 2,3,9,10,16,17,23,24-octa(2-benzyloxyethoxy) phthalocyaninato copper ( CuPc ( OC 2 OBz )8), where terminal benzyl groups on the eight ethylene oxide side chains assist in forming unusually ordered, mechanically rigid thin films. New spectroscopic characterization of cast CuPc ( OC 2 OBz )8 films is discussed in comparison with cast films of its metal-free analogue H 2 Pc ( OC 2 OBz )8 and similar copper and dihydrogen phthalocyanines with benzyl — terminated triethylene oxide substituents, CuPc (( OC 2 O )3 Bz )8, and H 2 Pc (( OC 2 O )3 Bz )8, which do not demonstrate the same degree of ordering as CuPc ( OC 2 OBz )8. AFM studies of horizontally transferred LB films of CuPc ( OC 2 OBz )8 show column–column distances of ca 2.8 nm and confirm the high degree of ordering previously surmised from spectroscopic characterization of multilayer thin films. The oxidative electrochemistry of multilayer thin films prepared from these Pcs is strongly dependent on the chemical identity of the supporting electrolyte anion and on annealing of the thin films. Compliance of the films to counter-ion transport limits the extent of electrochemical doping. Preliminary studies of the oxidative electrochemistry of isolated CuPc ( OC 2 OBz )8 aggregates (diluted into an electroinactive methyl arachidate thin film) on an electroactive, integrated optic waveguide (EA-IOW) are also presented. Monitoring the change in absorbance at 633 nm on the waveguide surface allows the determination of the onset potential for oxidation of the isolated aggregates, which appears to be less positive in potential versus that observed for multilayer Pc assemblies.
Synthesis of the 6,7-bis[2-methoxycarbonyl(1,1- dideutero)-ethyl] derivative of protoporphyrin IX dimethyl ester
Authors: SHIM YOUNG KEY , PANDEY RAVINDRA K. , SMITH KEVIN M.
Published: September 2002

A new total synthesis of a protoporphyrin IX derivative in which the α-methylene protons of the 13,17-(2-methoxycarbonylethyl) substituents are regioselectively deuterated is described. The deuterated porphyrin was obtained using the oxidative cyclization of an a,c-biladiene dihydrobromide.
Sliding–window neural state estimation in a power plant heater line
Authors: Alessandri A. , Parisini T. , Zoppoli R.
Published: September 2002

The state estimation problem for a section of a real power plant is addressed by means of a recently proposed sliding‐window neural state estimator. The complexity and the nonlinearity of the considered application prevent us from successfully using standard techniques as Kalman filtering. The statistics of the distribution of the initial state and of noises are assumed to be unknown and the estimator is designed by minimizing a given generalized least‐squares cost function. The following approximations are enforced: (i) the state estimator is a finite‐memory one, (ii) the estimation functions are given fixed structures in which a certain number of parameters have to be optimized (multilayer feedforward neural networks are chosen from among various possible nonlinear approximators), (iii) the algorithms for optimizing the parameters (i.e., the network weights) rely on a stochastic approximation. Extensive simulation results on a complex model of a part of a real power plant are reported to compare the behaviour of the proposed estimator with the extended Kalman filter. Copyright © 2001 John Wiley & Sons, Ltd.
Neural network adaptive robust control with application to precision motion control of linear motors
Authors: Gong J. Q. , Yao Bin
Published: September 2002

In this paper, neural networks (NNs) and adaptive robust control (ARC) design philosophy are integrated to design performance‐oriented control laws for a class of single‐input–single‐output (SISO)nth‐order non‐ linear systems. Both repeatable (or state dependent) unknown non‐linearities and non‐repeatable unknown non‐linearities such as external disturbances are considered. In addition, unknown non‐linearities can exist in the control input channel as well. All unknown but repeatable non‐linear functions are approximated by outputs of multi‐layer neural networks to achieve a better model compensation for an improved performance. All NN weights are tuned on‐line with no prior training needed. In order to avoid the possible divergence of the on‐line tuning of neural network, discontinuous projection method with fictitious bounds is used in the NN weight adjusting laws to make sure that all NN weights are tuned within a prescribed range. By doing so, even in the presence of approximation error and non‐repeatable non‐linearities such as disturbances, a controlled learning is achieved and the possible destabilizing effect of on‐line tuning of NN weights is avoided. Certain robust control terms are constructed to attenuate various model uncertainties effectively for a guaranteed output tracking transient performance and a guaranteed final tracking accuracy in general. In addition, if the unknown repeatable model uncertainties are in the functional range of the neural networks and the ideal weights fall within the prescribed range, asymptotic output tracking is also achieved to retain the perfect learning capability of neural networks in the ideal situation. The proposed neural network adaptive control (NNARC) strategy is then applied to the precision motion control of a linear motor drive system to help to realize the high‐performance potential of such a drive technology. NN is employed to compensate for the effects of the lumped unknown non‐linearities due to the position dependent friction and electro‐magnetic ripple forces. Comparative experiments verify the high‐performance nature of the proposed NNARC. With an encoder resolution of 1 µm, for a low‐speed back‐and‐forth movement, the position tracking error is kept within ±2 µm during the most execution time while the maximum tracking error during the entire run is kept within ±5.6 µm. Copyright © 2001 John Wiley & Sons, Ltd.
Strategic response to mandatory reporting legislation in the U.S. livestock and meat industries: Are collusive opportunities enhanced?
Authors: Wachenheim Cheryl J. , DeVuyst Eric A.
Published: September 2002

Recent federal legislation requires U.S. meat packers to report detailed information about livestock and meat transactions. The goal of this legislation is to improve competitiveness within the livestock sector and improve decision making within the marketing channel. We discuss the effect of industry structure and market transaction information on the competitive behavior of participant firms and why this legislation may actually reduce the price paid to livestock producers. [JEL Classification: L100, L110, L120] © 2001 John Wiley & Sons, Inc.
Diachronic patterns of dental hypoplasias and vault porosities during the predynastic in the Naqada region, Upper Egypt
Authors: Keita S.O.Y. , Boyce A.J.
Published: September 2002

The diachronic pattern of the frequencies of linear enamel hypoplasias and porotic hyperostosis was studied in temporally separated samples of adult predynastic Egyptian remains from the Naqada region, Upper Egypt. The samples covered a period of increasing population density and social complexity as well as decreasing Nile flooding in Egypt. First and second molars were evaluated for hypoplasias in material from the Naqada I, II, and III periods; sample sizes were 13, 30, and 25, respectively, for the first molar, and 11, 28, and 24 for the second molar. Cranial vaults were examined for porotic hyperostosis using several approaches; sample sizes were 26, 66, and 51 for Naqada I, II and III, respectively. Linear regression showed a decreasing trend for several variables: for the individual frequency of first molar hypoplasias (ρ = 0.025), the vault porosity score, which indicates the severity of the lesions (ρ < 0.001), and the extent score, which indicates the number of superior vault bones having porosities (ρ < 0.001). Logistic regression showed a temporal decline in the percentage of crania per sample having any vault porosities and only higher grade lesions (ρ < 0.012 and ρ < 0.003, respectively). Lesions of the second molar showed no directional trend. The results contrast with the common observation that these skeletal markers usually increase in contexts of increasing population density and social complexity. Am. J. Hum. Biol. 13:733–743, 2001. © 2001 Wiley‐Liss, Inc.
A case‐control study of the relationship between the risk of colon cancer in men and exposures to occupational agents
Authors: Goldberg Mark S. , Parent Marie‐Élise , Siemiatycki Jack , Désy Marie , Nadon Louise , Richardson Lesley , Lakhani Ramzan , Latreille Benoit , Valois Marie‐France
Published: September 2002

Background

We conducted a population‐based case‐control study in Montreal, Canada, to explore associations between hundreds of occupational circumstances and several cancer sites, including colon.

Methods

We interviewed 497 male patients with a pathologically confirmed diagnosis of colon cancer, 1514 controls with cancers at other sites, and 533 population‐based controls. Detailed job histories and relevant potential confounding variables were obtained, and the job histories were translated by a team of chemists and industrial hygienists into a history of occupational exposures.

Results

We found that there was reasonable evidence of associations for men employed in nine industry groups (adjusted odds ranging from 1.1 to 1.6 per a 10‐year increase in duration of employment), and in 12 job groups (OR varying from 1.1 to 1.7). In addition, we found evidence of increased risks by increasing level of exposures to 21 occupational agents, including polystyrene (OR for “substantial” exposure (ORsubst) = 10.7), polyurethanes (ORsubst = 8.4), coke dust (ORsubst = 5.6), mineral oils (ORsubst = 3.3), polyacrylates (ORsubst = 2.8), cellulose nitrate (ORsubst = 2.6), alkyds (ORsubst = 2.5), inorganic insulation dust (ORsubst = 2.3), plastic dusts (ORsubst = 2.3), asbestos (ORsubst = 2.1), mineral wool fibers (ORsubst = 2.1), glass fibers (ORsubst = 2.0), iron oxides (ORsubst = 1.9), aliphatic ketones (ORsubst = 1.9), benzene (ORsubst = 1.9), xylene (ORsubst = 1.9), inorganic acid solutions (ORsubst = 1.8), waxes, polishes (ORsubst = 1.8), mononuclear aromatic hydrocarbons (ORsubst = 1.6), toluene (ORsubst = 1.6), and diesel engine emissions (ORsubst = 1.5). Not all of these effects are independent because some exposures occurred contemporaneously with others or because they referred to a group of substances.

Conclusions

We have uncovered a number of occupational associations with colon cancer. For most of these agents, there are no published data to support or refute our observations. As there are few accepted risk factors for colon cancer, we suggest that new occupational and toxicologic studies be undertaken focusing on the more prevalent substances reported herein. Am. J. Ind. Med. 39:531–546, 2001. © 2001 Wiley‐Liss, Inc.
Subspecific genetic differences in the saddle‐back tamarin (Saguinus fuscicollis) postcranial skeleton
Authors: Kohn Luci Ann P. , Langton Laura Bishoff , Cheverud James M.
Published: September 2002

Saddle‐back tamarins (Saguinus fuscicollis) have been differentiated into subspecies based on coat color and facial morphology. Morphology of first‐generation genetic hybrids can provide an understanding of population differences and evolution that may otherwise be difficult to obtain. This study compares postcranial morphology in two hybrids of saddle‐back tamarins (S. f. illigeri × S. f. lagonotus and S. f. illigeri × S. f. leucogenys) to the purebred subspecies. We examine whether postcranial morphology differs between the purebred subspecies and their hybrids, and whether hybrids exhibit heterosis indicative of genetic differences between the parental subspecies. Fifty postcranial dimensions, or traits, were measured on 287 S. fuscicollis skeletons. Measurements were corrected for sex differences and environmental differences (wild‐derived or laboratory‐born). Females were larger than males for most postcranial dimensions, especially in the pelvis. Significant environmental differences were found throughout the postcranial skeleton, with wild‐derived animals generally larger than animals born in the laboratory. Significant heterosis was found for six postcranial traits in the S. f. illigeri × S. f. leucogenys cross, and heterosis was found for 15 postcranial traits in the S. f. illigeri × S. f. lagonotus cross. These results suggest that subspecies differences in skeletal morphology are generally due to genetic rather than environmental differences. The subspecies appear to represent geographic isolates that differ in gene frequencies and directional dominance for skeletal traits. Am. J. Primatol. 54:41–56, 2001. © 2001 Wiley‐Liss, Inc.
Individual variation in the growth of captive infant gorillas
Authors: Bellisari Anna , Newman Timothy K. , Greenberg Chandra , Rogers Jeffrey , Towne Bradford
Published: September 2002

Serial anthropometric data were obtained during the first year of life of six nursery‐reared infant gorillas in the Columbus (Ohio) Zoo. Two of the infants are likely to be monozygotic twins as determined by DNA analysis. Growth curves were fitted to serial measures of cephalo‐thoracic‐abdominal length, arm length, leg length, head circumference, upper arm circumference, and weight from each gorilla, to describe individual patterns of variation in skeletal growth and body composition. Growth in skeletal measures tended to be curvilinear to varying degrees over the first year of life. Body composition varied more than skeletal measures throughout the first year as a consequence of individual health status. Individual growth and body composition variations appear to reflect both genetic and environmental influences in this small sample of captive infant gorillas. Am J Phys Anthropol 115:110–132, 2001. © 2001 Wiley‐Liss, Inc.
Presumed pre‐ or perinatal arterial ischemic stroke: Risk factors and outcomes
Authors: Golomb Meredith R. , MacGregor Daune L. , Domi Trish , Armstrong Derek C. , McCrindle Brian W. , Mayank Supriya , DeVeber Gabrielle A.
Published: September 2002

A subgroup of children with arterial ischemic stroke in the pre‐ or perinatal period present with delayed diagnosis. We identified 22 children who met the following criteria: (1) normal neonatal neurological history, (2) hemiparesis and/or seizures first recognized after 2 months of age, and (3) computed tomography or magnetic resonance imaging showing remote cerebral infarct. Laboratory evaluations included protein C, protein S, antithrombin, activated protein C resistance screen (APCR), Factor V Leiden (FVL), prothrombin gene defect, methylene tetrahydrofolate reductase variant (MTHFR), anticardiolipin antibody (ACLA), and lupus anticoagulant. Not all children received all tests. Age at last visit ranged from 8 months to 16.5 years (median 4 years). Twelve were boys. Fourteen had left hemisphere infarcts. Median age at presentation was 6 months. Eighteen had gestational complications. Fourteen children had at least transient coagulation abnormalities (ACLA = 11, ACLA + APCR = 1, APCR = 2 with FVL + MTHFR = 1); 6 of these children had family histories suggestive of thrombosis. Cardiac echocardiogram was unremarkable in the 15 tested. Outcomes included persistent hemiparesis in 22; speech, behavior, or learning problems in 12; and persistent seizures in 5, with no evidence of further stroke in any patient. The persistence and importance of coagulation abnormalities in this group need further study.
Proton magnetic resonance spectroscopy of brain metabolites in galactosemia
Authors: Wang Zhiyue J. , Berry Gerard T. , Dreha Steffi F. , Zhao Huaqing , Segal Stanton , Zimmerman Robert A.
Published: September 2002

Brain edema may occur in infants with galactosemia and has been associated with accumulation of galactitol. Proton magnetic resonance spectra were obtained from 12 patients (four newly diagnosed neonates and eight patients on galactose‐restricted diets, age range 1.7–47 years) and control subjects to measure brain galactitol levels in vivo and correlate them with urinary galactitol excretion. The results demonstrate that a markedly elevated brain galactitol level may be present only in newborn infants with galactosemia who exhibit massive urinary galactitol excretion.
Patterned nanostructured arrays for high‐density magnetic recording
Authors: Tofail S. A. M. , Rahman I. Z. , Rahman M. A.
Published: September 2002

This article reviews the recent advances in patterned magnetic nanostructures for application in high‐density recording. In this connection we discuss: (1) the fundamental limits of magnetic recording on conventional magnetic disks and the need for newer materials; (2) the state‐of‐the art technology for creating arrays of magnetic nanostructures; and (3) prospects and problems of high‐ or ultrahigh‐density recording using these nanostructured arrays. Copyright © 2001 John Wiley & Sons, Ltd.