bluuebunny/crossref_metadata_2025 huggingface dataset:
A combined rh‐adaptive scheme based on domain subdivision. Formulation and linear examples
Authors: Askes Harm , Rodríguez‐Ferran Antonio
Published: August 2002

An adaptive scheme is proposed in which the domain is split into two subdomains. One subdomain consists of regions where the discretization is refined with an h‐adaptive approach, whereas in the other subdomain node relocation or r‐adaptivity is used. Through this subdivision the advantageous properties of both remeshing strategies (accuracy and low computer costs, respectively) can be exploited in greater depth. The subdivision of the domain is based on the formulation of a desired element size, which renders the approach suitable for coupling with various error assessment tools. Two‐dimensional linear examples where the analytical solution is known illustrate the approach. It is shown that the combined rh‐adaptive approach is superior to its components r‐ and h‐adaptivity, in that higher accuracies can be obtained compared to a purely r‐adaptive approach, while the computational costs are lower than that of a purely h‐adaptive approach. As such, a more flexible formulation of adaptive strategies is given, in which the relative importance of attaining a pre‐set accuracy and speeding‐up the computational process can be set by the user. Copyright © 2001 John Wiley & Sons, Ltd.
Well‐posedness and numerical performances of the strain gap method
Authors: Romano G. , Marotti de Sciarra F. , Diaco M.
Published: August 2002

A mixed method of approximation is discussed starting from a suitably modified expression of the Hu‐Washizu variational principle in which the independent fields are displacements, stresses and strain gaps defined as the difference between compatible strains and strain fields. The well‐posedness of the discrete problem is discussed and necessary and sufficient conditions are provided. The analysis of the mixed method reveals that the discrete problem can be split into a reduced problem and in a stress recovery. Accordingly, the discrete stress solution is univocally determined once an interpolating stress subspace is chosen. The enhanced assumed strain method by Simo and Rifai is based on an orthogonality condition between stresses and enhanced strains and coincides with the reduced problem. It is shown that the mixed method is stable and converges. Computational issues in the context of the finite element method are discussed in detail and numerical performances and comparisons are carried out. Copyright © 2001 John Wiley & Sons, Ltd.
A note on finite difference discretizations for Poisson equation on a disk
Authors: Lai Ming‐Chih
Published: August 2002

A simple second‐order finite difference treatment of polar coordinate singularity for Poisson equation on a disk is presented. By manipulating the grid point locations, we can successfully avoid finding numerical boundary condition at the origin so that the resulting matrix is simpler than traditional schemes. The treatments for Dirichlet and Neumann boundary problems are slightly different by adjusting the radial mesh width. Furthermore, the present discretization can be applied with slight modifications to Helmholtz‐type equations. The numerical evidence shows that the second‐order accuracy can also be preserved. © 2001 John Wiley & Sons, Inc. Numer Methods Partial Differential Eq 17: 199–203, 2001
Resourcefulness and health practices of diabetic women
Authors: Zauszniewski Jaclene A. , Chung ChaeWeon
Published: August 2002

More than one fourth of the millions of Americans with Type 2 diabetes experience depression, of which two thirds are women. Unless the individual is resourceful, coexisting diabetes and depression adversely affect one' health practices. The effects of diabetic and depressive symptoms on health practices and the mediating and moderating role of learned resourcefulness in this relationship were examined in 90 women with Type 2 diabetes. Regression analyses showed direct negative effects of diabetic and depressive symptoms on health practices. The effects of depressive, but not diabetic, symptoms were partially mediated by resourcefulness; no moderating effects were found. The results suggest the need to test interventions to minimize symptoms associated with diabetes, particularly depression. Teaching resourcefulness to Type 2 diabetic women may promote their positive health practices by minimizing their depression. © 2001 John Wiley & Sons, Inc. Res Nurs Health 24: 113–121, 2001
Maternal insertion of 18q11.2–q12.2 in 18p11.3 of the same chromosome analysed by microdissection and multicolour banding (MCB)
Authors: Starke Heike , Senger Gabriele , Kossakiewicz Maria , Tittelbach Hanne , Rau Dorothea , Rubtsov Nikolai , Trifonov Vladimir , Heller Anita , Hartmann Isabell , Claussen Uwe , Liehr Thomas
Published: August 2002

Objectives

Different aberrations in one chromosome 18 were prenatally detected during each of three different pregnancies of a healthy woman. Routine cytogenetic analysis revealed a morphologically altered maternal chromosome 18 as well. The purpose of the current study was to characterize these cytogenetic changes in detail and thus to clarify the reason for the recurrent appearance of morphologically altered chromosomes 18 in this family.

Methods

As GTG banding did not allow resolution of the kind of aberrations present in these four cases, the following molecular cytogenetic approaches were used: microdissection combined with reverse painting and multicolour banding (MCB) analysis using a chromosome 18 specific probe set.

Results

Molecular cytogenetic approaches revealed that fetus 1 had a derivative chromosome del(18)(q11.2q12.2), fetus 2 and the mother had the identical derivative chromosomes ins(18)(pterp11.32::q12.2q11.2::p11.32q11.2::q12.3qter) and fetus 3 had a dup(11.2q12.2).

Conclusion

Partial monosomy in fetus 1 and partial trisomy in fetus 3 can be explained by crossing over events during maternal meiosis. Copyright © 2001 John Wiley & Sons, Ltd.
‘Fourth hurdle reviews’, NICE, and database applications
Authors: Paul John E. , Trueman Paul
Published: August 2002

The ‘fourth hurdle’ is commonly described as what has to be done to gain market access and reimbursement for a pharmaceutical, medical technology, or biotech product. Demonstrating to regulatory agencies just a product's safety, efficacy, and quality (the first three hurdles) is no longer sufficient. Manufacturers must often now demonstrate both clinical effectiveness (Is the new product better than currently available alternatives, including no treatment?) as well as cost‐effectiveness (Is the product good value for money?) in order to assure success in the marketplace. In the last few years there have been a number of governmental and non‐governmental agencies constituted for fourth hurdle reviews and recommendations to governments and other funding and reimbursement agencies. The National Institute for Clinical Effectiveness (NICE) in the UK, although not the first such group, is arguably the most visible and influential. This paper describes the NICE review process in detail, as well as the expected substantial impact of fourth hurdle reviews on drug development and clinical trials. Potential uses of databases and modelling in fourth hurdle reviews are also explored. Copyright © 2001 John Wiley & Sons, Ltd.
Reactive Alder‐ene blend of diallyl bisphenol A novolac and bisphenol A bismaleimide: synthesis, cure and adhesion studies
Authors: Gouri C , Reghunadhan Nair C P , Ramaswamy R
Published: August 2002

A novel, addition‐curable novolac resin (ABPF) was synthesized by the reaction of diallyl bisphenol A with formaldehyde using p‐toluene sulfonic acid as the catalyst. The synthesis conditions were optimized to obtain soluble polymer of desirable molecular weight distribution which was characterized by FT‐IR, NMR and SEC. ABPF was reactively blended with bisphenol A bismaleimide (BMIP) and cured through an Alder‐ene reaction at high temperatures. The cure characteristics of BMIP–ABPF blend with a maleimide:allyl phenol stoichiometry of 1:1 were studied using FT‐IR, DSC and DMA, which evidenced the multi‐step cure reactions taking place in the system. Cure optimization was evaluated by DSC, DMA and adhesive property tests. The moderately crosslinked blend was conducive for achieving the optimum adhesive properties on aluminium substrates. Retention of the adhesive properties was greater than 100% at 150 °C.

© 2001 Society of Chemical Industry
Optimization and characterization of amorphous/crystalline silicon heterojunction solar cells
Authors: Jensen N. , Hausner R. M. , Bergmann R. B. , Werner J. H. , Rau U.
Published: August 2002

Amorphous hydrogenated silicon/crystalline silicon (a‐Si:H/c‐Si) heterojunction solar cells are investigated and optimized with regard to efficiency and simplicity of processing. Starting with a survey of a‐Si:H/c‐Si heterojunction solar cell results from the literature, we describe the fabrication steps of our a‐Si:H/c‐Si technology and analyze the electronic device properties by quantum efficiency, current–voltage, admittance, and capacitance–voltage measurements. The open‐circuit voltage and the fill factor of the a‐Si:H/c‐Si heterojunction solar cells under investigation are limited by recombination in the neutral zone of the crystalline Si absorber. Recombination at the a‐Si:H/c‐Si‐interface is subsidiary in respect of the limitation of the open‐circuit voltage. Our best n‐type a‐Si:H/p‐type c‐Si solar cell prepared without high‐efficiency features such as back‐surface field or surface texturing has an independently confirmed efficiency of 14.1% and an open‐circuit voltage of 655 mV. Copyright © 2001 John Wiley & Sons, Ltd.
Functionalization of self‐assembled monolayers on glass and oxidized silicon wafers by surface reactions
Authors: Flink Simon , van Veggel Frank C. J. M. , Reinhoudt David N.
Published: August 2002

Surface reactions were employed to introduce a variety of functional groups in self‐assembled monolayers (SAMs) on hydroxylated surfaces such as glass and oxidized silicon wafers. The resulting layers were fully characterized by wettability studies, ellipsometry, Brewster angle infrared and x‐ray photoelectron spectroscopy, UV–visible absorption and fluorescence measurements. Based on these measurements, it was concluded that the steric hindrance of the monolayer hampered the surface reactions, which generally led to sub‐monolayer coverages. Detailed information concerning the interactions amongst adsorbates was obtained from fluorescence measurements. The characteristic excimer emission of pyrene‐functionalized layers showed a large dependence on the solvent that was in contact with the SAM. Furthermore, efficient energy transfer could be observed in mixed monolayers that contained both fluorescein and lissamine groups. Copyright © 2001 John Wiley & Sons, Ltd.
Salt solutions in different solvents and their effect on the stereoselectivity of products of Diels–Alder reaction
Authors: Kumar Anil , Phalgune Usha D. , Pawar S. S.
Published: August 2002

A salt solution prepared in one solvent promotes higher endo products of a Diels–Alder reaction, such as the cyclopentadiene–methyl acrylate reaction, but yields less endo products when prepared in another solvent. The reactions of cyclopentadiene with methyl acrylate were carried out in solutions of LiClO4 and LiCl in several organic solvents and water. Aqueous LiClO4, which lowers the amount of endo product of the above reaction, enhances it in solvents such as diethyl ether and ethyl acetate. Similarly, aqueous LiCl, which acts as a rate‐promoting agent, reduces the amount of endo products in several organic solvents. The experimental solubility measurements support this change in the characteristics of a salt from salting‐in to salting‐out in different solvents and vice versa. The dual role of a salt in solvents is also supported by salting coefficients calculated based on theory. Copyright © 2001 John Wiley & Sons, Ltd.
Effect of the structural parameters of a series of fluoromonoacrylates on the surface properties of cured films
Authors: Ameduri B. , Bongiovanni R. , Lombardi V. , Pollicino A. , Priola A. , Recca A.
Published: August 2002

A series of fluorinated acrylates [F(CF2)q(CH2)pOCOCHCH2, where q = 8 and p = 2 ÷ 11) were synthesized and used as comonomers in the photopolymerization of acrylic systems. These fluoroacrylates were synthesized in a three‐step procedure through the radical addition of perfluoroalkyliodides to an unsaturated alcohol followed by their acrylation. The mixtures, containing up to 0.8% (w/w) of the comonomers, produced transparent films after UV curing; they showed changes in the surface properties as a function of the comonomer type and concentration. With contact‐angle and X‐ray photoelectron spectroscopy analyses, the relationship between the structure of the monomers and the surface properties of the UV‐cured films was investigated: the wettability decreased, depending on the length of the fluorinated group (q value) and the hydrogenated segment of the monomer (p value). © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4227–4235, 2001
Synthesis of star‐shaped poly(D,L‐lactic acid‐alt‐glycolic acid)‐b‐poly(L‐lactic acid) with the poly(D,L‐lactic acid‐alt‐glycolic acid) macroinitiator and stannous octoate catalyst
Authors: Dong Chang‐Ming , Qiu Kun‐Yuan , Gu Zhong‐Wei , Feng Xin‐De
Published: August 2002

Two types of three‐arm and four‐arm, star‐shaped poly(D,L‐lactic acid‐alt‐glycolic acid)‐b‐poly(L‐lactic acid) (D,L‐PLGA50‐b‐PLLA) were successfully synthesized via the sequential ring‐opening polymerization of D,L‐3‐methylglycolide (MG) and L‐lactide (L‐LA) with a multifunctional initiator, such as trimethylolpropane and pentaerythritol, and stannous octoate (SnOct2) as a catalyst. Star‐shaped, hydroxy‐terminated poly(D,L‐lactic acid‐alt‐glycolic acid) (D,L‐PLGA50) obtained from the polymerization of MG was used as a macroinitiator to initiate the block polymerization of L‐LA with the SnOct2 catalyst in bulk at 130 °C. For the polymerization of L‐LA with the three‐arm, star‐shaped D,L‐PLGA50 macroinitiator (number‐average molecular weight = 6800) and the SnOct2 catalyst, the molecular weight of the resulting D,L‐PLGA50‐b‐PLLA polymer linearly increased from 12,600 to 27,400 with the increasing molar ratio (1:1 to 3:1) of L‐LA to MG, and the molecular weight distribution was rather narrow (weight‐average molecular weight/number‐average molecular weight = 1.09–1.15). The 1H NMR spectrum of the D,L‐PLGA50‐b‐PLLA block copolymer showed that the molecular weight and unit composition of the block copolymer were controlled by the molar ratio of L‐LA to the macroinitiator. The 13C NMR spectrum of the block copolymer clearly showed its diblock structures, that is, D,L‐PLGA50 as the first block and poly(L‐lactic acid) as the second block. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 409–415, 2002
Synthesis and properties of fluorinated polyimides. 1. Derived from novel 4,4″‐bis(aminophenoxy)‐3,3″‐trifluoromethyl terphenyl
Authors: Banerjee Susanta , Madhra Mukesh Kumar , Salunke Arun Kashinath , Maier Gerhard
Published: August 2002

A new diamine monomer, 4,4″‐bis(aminophenoxy)‐3,3″‐trifluoromethyl terphenyl (ATFT) was synthesized that led to a number of novel fluorinated polyimides by solution as well as thermal imidization routes when reacted with different commercially available dianhydrides like pyromellatic dianhydride (PMDA), benzophenone tetracarboxylic acid dianhydride (BTDA), or 2,2‐bis(3,4‐dicarboxyphenyl) hexafluoropropane (6FDA). The polyimides ATFT/BTDA and ATFT/6FDA derived from both routes were soluble in several organic solvents such as N,N‐dimethylformamide, N,N‐dimethylacetamide, and dimethyl sulfoxide. The polyimide ATFT/PMDA was only soluble in N‐methylpyrollidone. The polyimide films had low water absorption of 0.3–0.7%, low dielectric constants of 2.72–3.3 at 1 Hz, refractive indices of 1.594–1.647 at 589.3 nm, and optical transparency >85%. These polyimides showed very high thermal stability with decomposition temperatures (5% weight loss) up to 532 °C in air and good isothermal stability; only 7% weight loss occurred at 400 °C after 7 h, and less than 0.6% weight loss was observed at 315 °C for 5 h. Transparent thin films of these polyimides exhibited tensile strengths up to 112 MPa, a modulus of elasticity up to 3.05 GPa, and elongation at break up to 21% depending on the repeating unit structure. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1016–1027, 2002
Photochemical reactions of quaternary ammonium dithiocarbamates as photobase generators and their use in the photoinitiated thermal crosslinking of poly(glycidyl methacrylate)
Authors: Tachi Hideki , Yamamoto Takayuki , Shirai Masamitsu , Tsunooka Masahiro
Published: August 2002

The photochemical behavior of quaternary ammonium salts (QA salts) with N,N‐dimethyldithiocarbamate as photobase generators and the photoinitiated thermal crosslinking of poly(glycidyl methacrylate) (PGMA) with the QA salts were investigated. The formation of basic compounds in the photolysis of 1‐phenacyl‐(1‐azonia‐4‐azabicyclo[2,2,2]octane) N,N‐dimethyldithiocarbamate was ascertained by the color change of phenol red as an acid–base indicator. 1H NMR spectra of photoproducts in CDCl3 under N2 showed that the photolysis of 1‐naphthoylmethyl‐(1‐azonia‐4‐azabicyclo[2,2,2]octane) N,N‐dimethyldithiocarbamate resulted in the quantitative formation of triethylenediamine and a dithiocarbamate derivative. The presence of oxygen in the photolysis decreased the photolysis rate. The amine was also detected in its photolysis in polystyrene films. The effects of ammonio groups and counteranions of QA salts on the photoinitiated thermal crosslinking of PGMA films were also investigated. Quaternary ammonium dithiocarbamates acted as excellent photobase generators and effective photoinitiated thermal crosslinkers for PGMA. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1329–1341, 2001
New concept of positive photosensitive polyimide: Reaction development patterning (RDP)
Authors: Fukushima Takafumi , Oyama Toshiyuki , Iijima Takao , Tomoi Masao , Itatani Hiroshi
Published: August 2002

A soluble multiblock copolyimide without specific functional groups such as OH and COOH was prepared by a direct one‐pot polycondensation of two types of dianhydrides and diamines in the presence of γ‐valerolactone/pyridine catalyst usingN‐methylpyrrolidone (NMP)/toluene mixture as a solvent. The polyimide film containing the photosensitive agent diazonaphthoquinone (DNQ) compound gave positive‐tone behavior by UV irradiation, followed by development in a mixture of ethanolamine/NMP/H2O (1/1/1 by weight). The scanning electron microscopic photograph of the resultant image showed fine patterns with about 20 μm film thickness. Its pattern forming was based on the photorearrangement of diazonaphthoquinone, a process in which the ring‐opening reaction of imide units of the polyimide with the amine used as a developer and the following degradation of the polymer are induced. Such a new imaging technique combines principles of photolithography and etching of a polyimide to give, what we call, reaction development patterning in which the main chemical reactions directly related to the pattern formation occur during development. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3451–3463, 2001
Analysis of the residual entropy of amorphous polyethylene at 0 K*
Authors: Pyda M. , Wunderlich B.
Published: August 2002

The residual entropy of amorphous polyethylene (PE) at 0 K is discussed within the framework of the heat capacity (Cp). The measured Cp of the liquid was extended from the glass transition to low temperature by separately finding its three parts—the vibrational, conformational, and external contributions—and extrapolating each to low temperature. The vibrational Cp was calculated from the frequency distributions of the group vibrations on the basis of force constants obtained from experimental infrared and Raman spectra as well as the skeletal vibrations in the amorphous solid (glass) obtained from fitting of the appropriate experimental Cp to Debye functions in the form suggested by Tarasov. The conformational part of Cp was evaluated from a fit of the heat capacity of the liquid, decreased by the contributions of the vibrational and external parts, to a one‐dimensional Ising model that can be extrapolated to 0 K and requires two discrete states described by stiffness, cooperativity, and a degeneracy parameter. The external part was computed from the experimental data for expansivity and compressibility, fitted to an empirical equation of state, and modified at low temperatures in accordance with the Nernst–Lindemann approximation. The computed Cp of the liquid PE agreed with the experiment from 600 K to the beginning of the glass transition at about 260 K. Extending the heat capacity to 0 K, bypassing the freezing of the large‐amplitude conformational motion in the glass transition, led to a positive residual entropy and enthalpy and avoided the so‐called Kauzmann paradox. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1245–1253, 2002
Physical characterization of poly(ω‐pentadecalactone) synthesized by lipase‐catalyzed ring‐opening polymerization
Authors: Letizia Focarete Maria , Scandola Mariastella , Kumar Ajay , Gross Richard A.
Published: August 2002

The Candida antarctica lipase B (Novozyme‐435)‐catalyzed ring‐opening polymerization of ω‐pentadecalactone in toluene was performed. Poly(ω‐pentadecalactone) [poly(PDL)] was obtained in a 93% isolated yield in 4 h with a number‐average molecular weight of 64.5 × 103 g/mol and a polydispersity index of 2.0. The solid‐state properties of poly(PDL) were investigated by thermogravimetric analysis (TGA) coupled with mass spectrometry, differential scanning calorimetry (DSC), stress–strain measurements, wide‐angle X‐ray diffraction, and dynamic mechanical and dielectric spectroscopies. Poly(PDL) is a crystalline polymer that melts around 100 °C. The polyester shows good thermal stability, with a main TGA weight loss centered at 425 °C. Because of the high degree of poly(PDL) crystallinity, the glass transition (−27 °C) is revealed by relaxation techniques such as dynamic mechanical and dielectric spectroscopies, rather than by DSC. In addition to the glass transition, the viscoelastic spectrum of poly(PDL) also shows two low‐temperature secondary relaxations centered at −130 (γ) and −90 °C (β). They are attributed to local motions of the long methylene sequence (γ) and complex units involving water associated with the ester groups (β). The mechanical properties of poly(PDL) are typical of a hard, tough material, with an elastic modulus and yield parameters comparable to those of low‐density polyethylene. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1721–1729, 2001
Nonlinear rheology of highly entangled polymer solutions in start‐up and steady shear flow
Authors: Islam Mohammad T. , Archer Lynden A.
Published: August 2002

Orientation angle and stress‐relaxation dynamics of entangled polystyrene (PS)/diethyl phthalate solutions were investigated in steady and step shear flows. Concentrated (19 vol %) solutions of 0.995, 1.81, and 3.84 million molecular weight (MW) PS and a semidilute (6.4 vol %) solution of 20.6 million MW PS were used to study the effects of entanglement loss on dynamics. A phase‐modulated flow birefringence apparatus was developed to facilitate measurements of time‐dependent changes in optical equivalents of shear stress(n12≈ Cσ)and first normal stress differences(n1= n11− n22≈ CN1)in a planar‐Couette shear‐flow geometry. Flow birefringence results were supplemented with cone‐and‐plate mechanical rheometry measurements to extend the range of shear rates over which entangled polymer dynamics are studied. In slow(τ>) steady shear‐flow experiments using the ultrahigh MW polymer sample (20.6 × 106MW PS), steady‐staten12andn1results manifest unusual power‐law dependencies on shear rate[n12,ss∼0.4andn1,ss∼0.8]. At shear rates in the rangeτ<< τ, steady‐state orientation anglesχSSare found to be nearly independent of shear rate for all but the most weakly entangled materials investigated. For solutions containing the highest MW PS, an approximate plateau orientation angleχpin the range 20–24° is observed;χpvalues ranging from 14 to 16° are found for the other materials. In the start‐up of fast steady shear flow(γ˙ ≥ τ), transient undershoots in orientation angle are also reported. The molecular origins of these observations were examined with the help of a tube model theory that accommodates changes in polymer entanglement density during flow. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2275–2289, 2001
Permafrost monitoring in the high mountains of Europe: the PACE Project in its global context
Authors: Harris Charles , Haeberli Wilfried , Vonder Mühll Daniel , King Lorenz
Published: August 2002

This paper introduces the structure and organization of permafrost monitoring within global climate‐related monitoring programmes. The five‐tiered principle proposed for the Global Hierarchical Observing Strategy (GHOST) is applied to the Global Terrestrial Network for Permafrost (GTN‐P) monitoring system, and the European network of mountain permafrost boreholes established by the PACE project is discussed in the context of GTN‐P. Borehole design and standard PACE instrumentation are described and some preliminary data from selected boreholes are presented. The broader research aims of the PACE programme include geophysical investigations, mapping and GIS strategies, numerical distribution modelling, physical modelling of thaw‐related slope processes and mountain permafrost hazard assessment. Copyright © 2001 John Wiley & Sons, Ltd.

Le présent article décrit la structure et l'organisation du programme de surveillance du pergélisol et son intégration dans les programmes de surveillance du climat. Le principe à 5 niveaux proposé pour la stratégie d'observation hiérarchique (GHOST) est appliquée au réseau global de surveillance terrestre du pergélisol (GTN‐P). Le réseau européen de sondages dans le pergélisol établi par le projet PACE est discuté dans le contexte du GTN‐P. La localisation des sondages et l'instrumentation standard de PACE sont décrites et quelques données préliminaires de certains sondages sélectionnés sont présentées. Les recherches du programme PACE comprennent des recherches géophysiques, des stratégies de cartographie et de systèmes d'information géographique, des modèles de distribution numérique, des modèles physiques des processus de versants en relation avec le dégel et enfin des estimations des risques liés au pergélisol de montagne. Copyright © 2001 John Wiley & Sons, Ltd.
Terrain parameters and remote sensing data in the analysis of permafrost distribution and periglacial processes: principles and examples from southern Norway
Authors: Etzelmüller Bernd , Ødegård Rune S. , Berthling Ivar , Sollid Johan Ludvig
Published: August 2002

Alpine permafrost and frost‐related geomorphological processes are sensitive to climatic change. Thus, there is an increasing demand for permafrost maps in high‐alpine environments. The objective of this paper is to present the application of terrain analysis and classification based on digital elevation models (DEMs) together with remotely sensed data (e.g. Landsat TM) in mapping of permafrost and slope activity as a supplement to existing methods. The study reviews principles and recent developments in this field, and presents three different approaches in the form of case studies from mountain areas of southern Norway. Copyright © 2001 John Wiley & Sons, Ltd.

Le pergélisol alpin et les processus géomorphologiques dus au gel sont sensibles aux changements de climat. II y a, en conséquence, une demande accrue de cartes du pergélisol dans les environnements de hautes altitudes. L'objectif de cet article est de présenter comment l'analyse du terrain et une classification du sol basée sur des modèles d'altitude, combinées avec l'utilisation de données de télédétection (Landsat TM), peuvent servir à cartographier le pergélisol et l'activité géomorphologique sur les versants, et constituer un supplément aux méthodes déjà existantes. L'étude passe en revue les principes et les développements récents dans ce domaine et présente trois différentes approches dans des études de cas de régions montagneuses de Norvège méridionale. Copyright © 2001 John Wiley & Sons, Ltd.
Subcutaneous terbutaline in children with chronic severe asthma*
Authors: Payne Donald N.R. , Balfour‐Lynn Ian M. , Biggart Elizabeth A. , Bush Andrew , Rosenthal Mark
Published: August 2002

A continuous subcutaneous infusion of terbutaline (CSIT) was used to treat 8 children with chronic severe asthma who continued to experience frequent symptoms, despite treatment with regular oral prednisolone. Five patients experienced a symptomatic improvement from CSIT, leading to a reduction in regular medication. Three patients did not experience any lasting benefit from CSIT. The most common side effects were related to the infusion site (bruising and local infection).

CSIT may lead to an improvement in symptoms and a reduction in oral steroid dose in selected children with chronic severe asthma. These initial findings support the need for further controlled studies to evaluate the use of CSIT in severe childhood asthma. Pediatr Pulmonol. 2002; 33:356–361. © 2002 Wiley‐Liss, Inc.
Mechanical ventilation in children with severe asthma
Authors: Malmström Kristiina , Kaila Minna , Korhonen Kaj , Dunder Teija , Nermes Merja , Klaukka Timo , Sarna Seppo , Juntunen‐Backman Kaisu
Published: August 2002

Hospital admissions for childhood asthma have increased during the past few decades. The aim of this study was to describe the need for mechanical ventilation for severe asthma exacerbation in children in Finland from 1976 to 1995. We reviewed medical records and collected data retrospectively from all 5 university hospitals in Finland, thus covering the entire population of about 5 million. The endpoints selected were the number of admissions and readmissions leading to mechanical ventilation, duration of stay in the hospital, and mortality. Moreover, asthma medications prescribed prior to admission and administered in the intensive care unit (ICU), as well as the etiology of the exacerbation associated with mechanical ventilation were examined.

Mechanical ventilation was required in 66 ICU admissions (59 patients). This constituted approximately 10% of all 632 admissions for acute asthma to an ICU. The number of admissions decreased from 1976 to 1995: 41 admissions between 1976 and 1985 vs. 25 admissions during the next 10‐year period. The mean age at admission to the ICU was 3.6 years, and 46% of the patients were boys. Prior to the index admission, 70% of the patients had used asthma medication such as oral bronchodilator (50%), inhaled bronchodilator (20%), theophylline (38%), inhaled glucocorticoid (18%), oral glucocorticoid (5%), and cromoglycate (7%). Respiratory infection was by far the most common cause of all the exacerbations (61%), followed by food allergy (8%) and gastroesophageal reflux (3%). In 28% of cases the cause of the severe asthma exacerbation could not be identified. In the mechanically ventilated patients readmissions occurred 38 times between 1976 and 1985 vs. 5 times between 1986 and 1995. Five of the patients who received mechanical ventilation died, and in 3 of these patients asthma was the event causing death.

In conclusion, there has been decrease in the number of first and repeat ICU admission for asthma requiring mechanical ventilation between 1970 and 1995. This trend occurred despite a simultaneous 5% yearly increase in hospital admissions for childhood asthma during these 2 decades. Pediatr Pulmonol. 2001; 31:405–411. © 2001 Wiley‐Liss, Inc.
Prostate volume and prostate‐specific antigen in the absence of prostate cancer: A review of the relationship and prediction of long‐term outcomes
Authors: Lieber Michael M. , Jacobsen Steven J. , Roberts Rosebud O. , Rhodes Thomas , Girman Cynthia J.
Published: August 2002

Background

The risk for long‐term outcomes associated with benign prostatic hyperplasia (BPH) has not been well characterized. Untreated, BPH can lead to complications and negative outcomes, such as deterioration of bladder function, urinary tract infection, acute urinary retention (AUR), and surgery.

Methods

A literature review was conducted to summarize the results of studies investigating the relationship of prostate volume and PSA with prediction of long‐term outcomes in the absence of prostate cancer.

Results

In the studies reviewed, men with moderate to severe symptoms, depressed uroflow, prostatic enlargement and elevated PSA were at greater risk for developing subsequent AUR or surgery. Men with prostatic enlargement had a 3‐fold higher risk for acute urinary retention and were 4 times more likely to have had any treatment for BPH.

Conclusions

The results of these studies may assist physicians in discussing treatment options as well as long‐term complications with patients. Prostate 49:208–212, 2001. © 2001 Wiley‐Liss, Inc.
Dissecting protein–protein recognition sites
Authors: Chakrabarti Pinak , Janin Joël
Published: August 2002

The recognition sites in 70 pairwise protein–protein complexes of known three‐dimensional structure are dissected in a set of surface patches by clustering atoms at the interface. When the interface buries <2000 Å2of protein surface, the recognition sites usually form a single patch on the surface of each component protein. In contrast, larger interfaces are generally multipatch, with at least one pair of patches that are equivalent in size to a single‐patch interface. Each recognition site, or patch within a site, contains a core made of buried interface atoms, surrounded by a rim of atoms that remain accessible to solvent in the complex. A simple geometric model reproduces the number and distribution of atoms within a patch. The rim is similar in composition to the rest of the protein surface, but the core has a distinctive amino acid composition, which may help in identifying potential protein recognition sites on single proteins of known structures. Proteins 2002;47:334–343. © 2002 Wiley‐Liss, Inc.
Distributions of beta sheets in proteins with application to structure prediction
Authors: Ruczinski Ingo , Kooperberg Charles , Bonneau Richard , Baker David
Published: August 2002

We recently developed the Rosetta algorithm for ab initio protein structure prediction, which generates protein structures from fragment libraries using simulated annealing. The scoring function in this algorithm favors the assembly of strands into sheets. However, it does not discriminate between different sheet motifs. After generating many structures using Rosetta, we found that the folding algorithm predominantly generates very local structures. We surveyed the distribution of β‐sheet motifs with two edge strands (open sheets) in a large set of non‐homologous proteins. We investigated how much of that distribution can be accounted for by rules previously published in the literature, and developed a filter and a scoring method that enables us to improve protein structure prediction for β‐sheet proteins. Proteins 2002;48:85–97. © 2002 Wiley‐Liss, Inc.
Quantification of acetochlor degradation in the unsaturated zone using two novel in situ field techniques: comparisons with laboratory‐generated data and implications for groundwater risk assessments
Authors: Mills Margaret S , Hill Ian R , Newcombe Andrew C , Simmons Nick D , Vaughan Phil C , Verity Alison A
Published: August 2002

Degradation of the herbicide acetochlor in the unsaturated zone was quantified using two unique in situ field techniques. The DT50 values generated at two different sites on surface soil and two subsoil depths using these techniques were compared with values generated under aerobic laboratory‐incubation conditions (typically 20 °C, 40% maximum water holding capacity). Additionally, laboratory‐degradation data were generated on surface and subsoils from four other sites. All subsoils were treated with acetochlor at 5% of the surface soil application rate. Acetochlor degradation in both field‐ and laboratory‐incubated subsoils was rapid and often exceeded surface soil rates. Field and laboratory DT50 values from all sites ranged from 2 to 88 days in subsoil, compared with a range of 1 to 18 days in surface soils. The DT50 results from in situ field techniques were comparable with those generated from laboratory incubations in the same soils, confirming the validity of performing laboratory‐based degradation studies to determine pesticide DT50 values in subsoils. Microbiological characterisation of selected soils revealed that subsoils had a viable and active population, although direct counts of bacteria were consistently lower in subsoil (108–109 g−1 dry soil) compared with surface soils (1010 g−1 dry soil). The leaching models used to perform groundwater risk assessments (eg PELMO, PESTLA, MACRO‐DB, PRZM and the FOCUS EU leaching scenarios) have provision for inclusion of subsoil degradation rates. However, conservative default estimates are typically used, as no other alternative is available. Results presented here show that these default values may significantly underestimate true subsoil degradation contributions, and therefore not accurately predict pesticide concentrations in groundwater. The degradation data generated for acetochlor were applied to the mathematical model PELMO to demonstrate the importance of the inclusion of subsoil degradation data in groundwater risk assessment models and thereby in the registration of pesticides in Europe.

© 2001 Society of Chemical Industry
Negative cross‐resistance between dihydropyrazole insecticides and pyrethroids in houseflies, Musca domestica
Authors: Khambay Bhupinder P S , Denholm Ian , Carlson Glenn R , Jacobson Richard M , Dhadialla Tarlochan S
Published: August 2002

A series of insecticidal dihydropyrazoles and related compounds have been shown to exhibit negative cross‐resistance to a resistant (super‐kdr) strain of houseflies with site‐insensitivity to pyrethroids. The level of cross‐resistance is similar to that observed previously for a range of N‐alkylamides against the same strain.

© 2001 Society of Chemical Industry
Catechol as a nucleophilic catalyst of peptide bond formation
Authors: Ivanova Gabriela , Bratovanova Emilia , Petkov Dimiter
Published: August 2002

The aminolysis of a mildly activated aminoacid ester, benzyloxycarbonyl‐L‐phenylalanine cyanomethyl ester, by glycine esters in the presence of catechol has been studied as a model of catalysis by RNA cis‐vicinal‐diol systems in protein biosynthesis. Catechol accelerated the aminolysis, especially in the presence of bases, probably by nucleophilic catalysis. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd.
Rehabilitation of existing structures in seismic zones
Authors: Bob Corneliu
Published: August 2002

Existing structures built before the 1970s are gravity load designed with inadequate lateral load resistance because earlier codes specified lower levels of seismic loads and many of these structures are still in service beyond their design life. On the other hand, some deterioration of component parts of buildings are encountered in old structures due to the actions of different hazard factors. This paper discusses the characteristics of existing structures under seismic motions, general and specific solutions for rehabilitation with three examples.

Characteristics of existing structures and specific solutions for rehabilitation are detailed for reinforced concrete, steel and masonry structures. Rehabilitation of three different types of existing structures are described: a reinforced concrete framed structure with local damage caused by the action of chloride ions and reinforcement weakness; an old masonry structure which is at risk in the event of a future earthquake; a huge building at significant seismic risk, but without dangerous situation of structure elements.
Effect of ganhuangenin obtained from Scutellaria radix on the chemical mediator production of peritoneal exudate cells and immunoglobulin E level of mesenteric lymph node lymphocytes in Sprague‐Dawley rats
Authors: Lim Beong Ou
Published: August 2002

We previously showed that ganhuangenin (GHG) has beneficial antioxidative properties against lipid peroxidation in tissues of Sprague‐Dawley (SD) rats. In this study, the effect of GHG on immunoglobulin E (IgE), histamine and leukotriene B4 (LTB4) levels of cells isolated from SD rats was examined with regard to the manifestation of the type I allergic reaction. We showed that GHG inhibited the IgE production of mesenteric lymph node (MLN) lymphocytes. In the presence or absence of concanavalin A (ConA), the concentration used did not exert a toxic effect against MLN lymphocytes. Interestingly, the increase in the IgE content and lipid peroxidation induced by ConA was alleviated in the presence of GHG. Moreover, GHG also inhibited histamine release from the peritoneal exudate cells stimulated with a calcium ionophore, A23187, or with the histamine releaser, compound 48/80. In the case of LTB4, GHG markedly inhibited its release at a concentration of 100 μM. Thus, it is concluded that GHG may block the common pathway for the release of histamine and LTB4, and that the IgE level is responsible for the lipid peroxidation induced by ConA. Copyright © 2002 John Wiley & Sons, Ltd.
Study of alkaloids from Adhatoda vasica Nees on their antiinflammatory activity
Authors: Chakraborty A. , Brantner A. H.
Published: August 2002

Adhatoda vasica Nees is a shrub widespread throughout the tropical regions of southeast Asia. It possesses a wide spectrum of medicinal properties including positive effects on inflammatory diseases. The antiinflammatory activity of the methanol extract, the non‐alkaloid fraction, the saponins and the alkaloids was evaluated by the modified hen's egg chorioallantoic membrane test. The alkaloid fraction showed potent activity at a dose of 50 µg/pellet equivalent to that of hydrocortisone while the MeOH extract and the other fractions showed less activity. Copyright © 2001 John Wiley & Sons, Ltd.
A reporter gene assay for the detection of phytoestrogens in traditional Chinese medicine
Authors: Miller‐Martini D. M. , Chan R. Y. K. , Ip N. Y. , Sheu S. J. , Wong Y. H.
Published: August 2002

Bupleurum & Peony Formula (Jia Wei Xiao Yao San) is a herbal formula which possesses a clinical history for the treatment of menopausal syndrome and menstrual irregularity. The present investigation reports the ability to monitor the formula's phytoestrogen content that will allow for the implementation of a standardization protocol that is based on a quantifiable biological response. Utilizing an oestrogen‐sensitive chimeric receptor/reporter gene element which has been stably transfected into HeLa cells, the botanical formula was shown to induce the expression of the reporter gene, luciferase, in a dose dependent manner. Pretreatment of the HeLa cells with the botanical formula produced a 5‐fold increase in bioluminescence compared with the control. Additionally, our studies showed that the response of the cells, when challenged by the botanical formula, was oestrogen specific. Pretreatment of the cells with tamoxifen effectively blocked the activation of the chimeric oestrogen receptor by the botanical formula. The cell line provides a sensitive assay that can easily detect the presence of phytoestrogens in complex botanical formulas. Copyright © 2001 John Wiley & Sons, Ltd.
On the distribution of the estimated process yield index Spk
Authors: Lee J. C. , Hung H. N. , Pearn W. L. , Kueng T. L.
Published: August 2002

This paper considers an asymptotic distribution for an estimate $\hat{S}_{pk}$ of the process yield index $S_{pk}$ proposed by Boyles (1994). The asymptotic distribution of $\hat{S}_{pk}$ is useful in statistical inferences for $S_{pk}$. An illustrative example is given for hypothesis testing and for interval estimation on the yield index $S_{pk}$. Copyright © 2002 John Wiley & Sons, Ltd.
Electronic structure of adamantane
Authors: Korolkov Dimitry V. , Sizova Olga V.
Published: August 2002

The geometry and electronic structure of adamantane and related molecular cations is studied with the emphasis on the electron density distribution on the face planes and in the carbon cage. The results are compared with the corresponding data for the boron hydrides and carbocations. The bonding in these compounds is discussed in terms of the theory of trishomoaromacity. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Common‐sense reasoning cast over D–U model in simulation of chemical reactions
Authors: Nowak Grażyna
Published: August 2002

The Ugi–Dugundji model of chemistry has been commonly applied as a mathematical tool aimed at the unrestricted prediction of the behavior of chemical objects. In the computer simulation of chemical reactions, it enables us to generate, for a given set of reagents, a mathematically complete product space, and therefore it can predict new unprecedented reactions. However, the principal drawback of this model is connected to the enormous solution space, which comprises all mathematically conceivable chemistry featuring very low reliability. For this reason, in the CSB system, the course of the chemical reaction generation is controlled through the examination and evaluation of reaction centers (i.e., reactive atoms and bonds) in reacting molecules. The resulting products space is determined by a set of recognized reaction centers and a set of schemes transforming these reaction centers in substrate/product molecules. In this article, the progress in the developed strategy is discussed, concerning the application of different methods for acquiring rules required to infer reaction sites. As a working example, the search for structure–reactivity correlations and the resulting product space are presented for a set of test structures. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem 84: 282–289, 2001
Evaluation of several solid phase extraction liquid chromatography/tandem mass spectrometry on‐line configurations for high‐throughput analysis of acidic and basic drugs in rat plasma
Authors: Mallet Claude R. , Mazzeo Jeff R. , Neue Uwe
Published: August 2002

Several configurations using 6‐ and 10‐port switching valves were studied for high flow, on‐line extraction of rat plasma coupled to an electrospray triple quadrupole mass spectrometer. Each plasma sample was diluted 1:1 with an aqueous internal standard solution. The sample was injected into a 2.1 × 20 mm cartridge column packed with 25 µm divinylbenzene/N‐vinylpyrrolidone packing using 100% aqueous mobile phase at 4 mL/min. After sample loading and sample cleanup, the analytes were eluted from the extraction column with a 1.0‐min gradient at 0.4 mL/min. The samples were either analyzed directly after elution from the extraction column or after additional separation using a short high performance liquid chromatography (HPLC) column. The different configurations were tested using an acidic drug (diflunisal) and a basic drug (clemastine) in rat plasma. On‐line analysis was performed by injecting 200 µL of diluted plasma. The mass spectrometer was operated in the multiple reaction monitoring (MRM) mode. All calibration standards gave relative standard deviations (RSDs) below 5%. The total time per sample was 3 min. Copyright © 2001 John Wiley & Sons, Ltd.