bluuebunny/crossref_metadata_2025_split huggingface dataset:
Online monitoring of birefringence development in heat‐setting polymer films with a fast dual‐wavelength optical technique. II. Uniaxially oriented PEN/PEI films
Authors: Galay J. , Cakmak M. 
Published: September 2002

AbstractThe influence of poly(ether imide) (PEI) on the structural ordering process in heat setting from the preoriented state of poly(ethylene 2,6‐naphthalene dicarboxylate) (PEN)/PEI blend films was investigated with the two‐color online birefringence system. The addition of small amounts of noncrystallizable PEI enhanced the crystallization from the preoriented state. This was attributed to the loosening of the structure with the addition of lower density and bulkier PEI at small concentrations. With a maximum effect around 15% PEI, a further increase in the concentration resulted in a dilution effect that spatially separated the crystallizable PEN chains. This slowed down the structural rearrangement process during heat setting. At elevated temperatures, the real‐time birefringence data obtained from the developed two‐color birefringence system temporally located the relaxation that followed with an increase in birefringence. This was associated with molecular relaxation due to melting followed by crystallization and partial reorientation of crystalline regions in the original stretching direction. © 2001 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 1147–1159, 2001
A novel ionic‐conduction mechanism based on polyurethane electrolyte
Authors: Zhu Weihua , Wang Xinling , Yang Bing , Tang Xiaozhen 
Published: September 2002

AbstractA series of poly(ethylene glycol)–polyurethane (PEG–PU)/sodium perchlorate (NaClO4) solid electrolytes were prepared, and their properties were characterized with Fourier transform infrared spectroscopy, differential scanning calorimetry, complex impedance analysis, and atomic force microscopy. Results showed that the oxygen atoms of carbonyl and ether oxygen groups had different activities on cations. Both carbonyl and ether oxygen groups participated in the ionic‐transport process in PU‐based electrolytes. There existed a coordination competition between sodium cations and different oxygen atoms in soft and hard segments of PU. For the PEG–PU/NaClO4 system investigated, amorphous regions and interfacial regions between the amorphous and microcrystalline phases were responsible for ionic conduction. A new ionic‐transport mechanism, based on the existence of conduction pathways not only in amorphous regions but also in interfacial regions of microphase‐separated PU‐based electrolytes, is sketched. Moreover, at a particular concentration of doped salt (EO/NaClO4 12), the PEG–PU/NaClO4 complex revealed a phase‐transition point in the morphology and exhibited minimum apparent activation energy and maximum ionic conductivity. © 2001 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 1246–1254, 2001
Detecting social problems in cancer patients
Authors: Wright E.P. , Selby P.J. , Gould A. , Cull A. 
Published: September 2002

AbstractDiagnosis of and treatment for cancer may not only create physical and emotional difficulties for patients but may also have an impact on social aspects of patients' lives. Screening for social problems has not become part of routine oncology practice. This may be due to lack of a suitable questionnaire. This paper presents a psychometric analysis of the Problems Checklist with a view to assessing its usefulness as a screening tool for social problems in oncology. Evaluation was undertaken using data from an earlier study of 505 patients who completed the checklist. Frequency of endorsement, missing values, factor analysis and reliability and validity analysis of the summated scales were carried out. Missing data rates ranged from 4 to 18% over the 16 items. Fourteen items were well endorsed. Factor analysis produced a four‐factor structure with components labelled daily living, relationships, economics and emotions. Reliability and validity tests endorsed the factor structure with the components on economics and emotions being particularly credible. Difficulties with relationships are harder to measure and results from the analysis suggest that this is an area that warrants further investigation. The checklist is a useful tool for highlighting problems. As a tool for screening for social problems it has some limitations. Copyright © 2001 John Wiley & Sons, Ltd.
Children with cancer with different survival perspectives: defensiveness, control strategies, and psychological adjustment
Authors: Grootenhuis Martha A. , Last Bob F. 
Published: September 2002

AbstractThe main objective of the present study was to investigate whether children with cancer with different survival perspectives differ in their psychological adjustment, defensiveness and their use of cognitive control strategies. Furthermore, the study investigated which variables predict emotional adjustment of these children with cancer most adequately. A total of n=84 children (n=43 children in remission and n=41 children not in remission) participated in the study. They answered questionnaires about control strategies, defensiveness, anxiety and depression. No differences were found in any of the questionnaires between children in remission and relapse. Emotional adjustment of the children was predicted by defensiveness and by positive expectations about the course of the illness. The findings demonstrate the importance of having positive expectations for the emotional adjustment of children with cancer. The strength of the study is the inclusion of a substantial group of children with cancer who have a reduced survival perspective. Copyright © 2001 John Wiley & Sons, Ltd.
Study of tau‐fluvalinate persistence in honey
Authors: Tsigouri Angeliki D , Menkissoglu‐Spiroudi Urania , Thrasyvoulou Anthreas 
Published: September 2002

AbstractThe persistence of the acaricide tau‐fluvalinate with time and the factors that can affect its degradation in honey were investigated. Two honey types of extreme pH values (3.85 and 5.40) were spiked with tau‐fluvalinate at two levels (50 and 200 µg kg−1) and incubated at 35 °C. Samples were analyzed in duplicate at various time intervals for up to 248 days. A simple, rapid and accurate method for the determination of tau‐fluvalinate residues in honey is proposed. Tau‐fluvalinate extraction and sample cleanup was carried out using C8 SPE cartridges with dichloromethane as the elution solvent. Analysis of samples was accomplished using gas chromatography with electron‐capture detection (GC–ECD). The overall recovery of the method was 90.25(±0.85)% and the limit of determination 1 µg kg−1. The results showed that tau‐fluvalinate stays stable in honey for more than 8 months, even at 35 °C. The effect of higher temperatures, similar to those used for honey packing, on tau‐fluvalinate persistence in honey was also studied. Honey samples fortified with 20 and 200 µg kg−1 tau‐fluvalinate were subjected to heat treatment similar to that in the honey blending and packing process. No degradation of tau‐fluvalinate due to the heat treatment was recorded. This long persistence increases the risk of honey contamination due to repeated and/or extended tau‐fluvalinate applications.© 2001 Society of Chemical Industry
Fatigue strength of welded joints made of high‐strength steels
Authors: Anami Kengo , Miki Chitoshi 
Published: September 2002

AbstractBy rearranging existing fatigue test results, fatigue performance of typical welded joints, (longitudinal, cruciform and out‐of‐plane gusset welded joint) are discussed with respect to the dependence on steel strength and on joint size. The relationship between fatigue strength and steel strength was not clear for longitudinal welded joints of small specimens and large‐scale girder specimens. For cruciform welded joints and out‐of‐plane gusset welded joints, fatigue strength of small joint specimens is independent of the steel strength, but that of girder specimens decreases with increase in steel strength. In addition, fatigue strengths of these two types of welded joints decrease with increase in joint size, especially for girder specimens.In order to discuss these relationships in detail, fatigue tests with out‐of‐plane gusset welded joint specimens and large‐scale girder specimens, including web gusset joints made of JIS SM570 and 900 MPa class steel were carried out. From the fatigue tests, similar tendencies were found to those obtained from existing test results. Although fatigue tests of joint specimens showed no difference in fatigue strength, crack initiation life and crack propagation rate between the steel strengths, fatigue strength of girder specimens made of 900 MPa class steels is much lower than for JIS SM570. In addition, fatigue strength of the girder specimens is considerably lower than that of the joint specimens. This difference results mainly from an increase in stress concentration due to joint geometry, and combination of nominal stress and shear stress in the girder specimens. It was found that the influence of the combination can be approximately evaluated from the nominal principal stress.
The properties and possible transformation path for C12B24N24
Authors: Yin Hong‐Ming , Zhang Rui‐Qin , Yang Ben‐Hui , Han Ke‐Li , He Guo‐Zhong 
Published: September 2002

AbstractThe structure and frequencies of C12B24N24 have been calculated by means of an ab initio method. By comparing the average bond energies with C60, the calculated results predict that the cage C12B24N24 is a stable molecule. The calculated results indicate that the cage molecule C12B24N24 has a relative large HOMO–LUMO energy gap and a low rigidity. The structures and stability of six possible isomers of C2B4N4 are used to suggest a possible transformation path from the pentagon CB2N2 to the C12B24N24 materials. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem 84: 363–368, 2001
A phase‐space method for arbitrary bimolecular gas‐phase reactions: Application to the CH3CHO+HO and CH3OOH+HO reactions
Authors: Gross A. , Mikkelsen K. V. , Stockwell W. R. 
Published: September 2002

AbstractA new method based upon phase‐space methods presented in Ref. 1 (Gross, A.; Mikkelsen, K. V., Stockwell, W. R. Int J Quantum Chem 2001, accepted) has been tested on the reactions CH3CHO+HO→CH3CO+H2O and CH3OOH+HO→products. The method has been used to calculate cross sections, and rate constants in the temperature range 200–550 K. The method requires knowledge of the system's reaction and product channels for the interacting species, the vibrational frequencies, the moments of inertia, and the potential energies of the molecules in their ground state equilibrium configuration. Furthermore, the long‐range potential between the reactant and product species is required. Due to the lack of experimentally determined spectroscopic data and potential energies for the reactants and products, these values have been calculated using electronic structure theory. We have used the many‐body second‐order Møller Plesset perturbation theory (MP2) for the treatment of electron correlation in the molecules, together with two different Gaussian‐type orbital (GTO) basis sets 6‐31G and 6‐31G*. The calculated rates are compared with the experimental data estimated earlier elsewhere. On the basis of our limited tests, the method appears to yield rate constants that are within a factor of 10–25 at 300 K of the true value, which is much more accurate than currently used empirical estimation methods. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Partial rates in the high‐frequency regime of intense‐field photoionization of hydrogen
Authors: Lefebvre R. , Stern B. 
Published: September 2002

AbstractComplex rotation in the exterior scaling version is applied to the solution of the coupled equations of Floquet theory for ground state hydrogen submitted to an external intense oscillating linearly polarized electric field. The calculations are done in the Kramers–Henneberger frame. The fluxes are calculated in the asymptotic real part of the integration axis. The total and 1‐photon rates are used to reassess the performances of a high‐frequency two‐pole approximation previously developed (J Phys B 1999, 32, 3271). For overthreshold frequencies, the partial rates with definite values of n, the number of absorbed photons, and l, the angular quantum number of the ejected electron, show oscillations which are erased when summing over l. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
The close‐coupling‐single center‐expansion (CC‐SCE) model for electron scattering from polyatomic targets
Authors: Curik R. , Gianturco F. A. , Sanna N. 
Published: September 2002

AbstractThe theoretical and computational study of elastic integral and differential cross sections for fairly large polyatomic targets is described in terms of quantum close‐coupled scattering equations cast within a symmetry‐adapted, single center expansion form of target wavefunctions, continuum electrons, and interaction potential. The latter is introduced in a local, real model form, and examples of its level of agreement with experiments are given for a class of many‐electron, polyatomic molecules like the halogenated silane derivatives. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Preparation and mass spectrometric study of egg yolk antibody (IgY) against rabies virus
Authors: Sun Shuqing , Mo Wenjun , Ji Yiping , Liu Shuying 
Published: September 2002

AbstractRabies virus was used as the antigen to immunize laying chickens. Anti‐rabies virus immunoglobulin Y(IgY) was isolated from yolks of the eggs laid by these chickens using a two‐step salt precipitation and one‐step gel filtration protocol. The purified IgY was reduced with dithiothreitol, and heavy chains (HC) and light chains (LC) were obtained. In addition, the purified IgY was digested with pepsin and the fragment with specific antigen binding properties (Fab) was produced. Using matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐TOFMS), the average molecular weights of IgY, HC, LC, and Fab were determined as 167 250, 65 105, 18 660, and 45,359 Da, respectively. IgY has two structural differences compared with mammalian IgGs. First, the molecular weight of the heavy chain of IgY is larger than that of its mammalian counterpart, while the molecular weight of the light chain of IgY is smaller. Second, upon pepsin digestion, anti‐rabies virus IgY is degraded into Fab, in contrast to mammalian IgG, which has been reported to be degraded into F(ab′)2 under the same conditions. Copyright © 2001 John Wiley & Sons, Ltd.
Copper(I) chloride: a simple salt for enhancement of polystyrene cationization in matrix‐assisted laser desorption/ionization mass spectrometry
Authors: Kéki Sándor , Deák György , Zsuga Miklós 
Published: September 2002

AbstractThe possibility of using copper(I) chloride as a doping salt to enhance the cationization of polystyrene in matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) was investigated. It was shown that copper(I) chloride possesses sufficient solubility in tetrahydrofuran. The parameters of the MALDI mass spectra of different polystyrene samples, such as the number‐average (Mn) and mass‐average (Mw) molecular mass values, obtained by copper(I) cationization were compared with those obtained by means of silver(I) cationization, and good agreement was found. It was also shown that application of copper(I) chloride as a doping salt, and dithranol as a matrix, ensured good MALDI mass spectra of the sample spots even after storage for 1 month. Copyright © 2001 John Wiley & Sons, Ltd.
Gln‐Gly cleavage: a dominant dissociation site in the fragmentation of protonated peptides
Authors: Jonsson Andreas P. , Bergman Tomas , Jörnvall Hans , Griffiths William J. 
Published: September 2002

AbstractAn understanding of the gas‐phase dissociation of protonated peptides within the mass spectrometer is essential for automated high‐throughput protein identification. In this communication we describe a facile cleavage of the Gln‐Gly peptide bond under low‐collisional energy conditions. A variety of synthetic peptides have been analysed where key amino acids have been substituted within the sequence PQGPPQQGGR, which is a consensus repeat present in the tryptic peptides of acidic proline‐rich protein 1 (PRP‐1). The collision‐induced dissociation spectra obtained from the PRP‐1 tryptic peptides and the synthetic peptides indicate that facile Gln‐Gly cleavage occurs when an X‐Gln‐Gly‐Y sequence is present in a peptide, where X is any amino acid and Y any amino acid other than Gly. Copyright © 2001 John Wiley & Sons, Ltd.
Formation of gas‐phase clusters monitored during electrospray mass spectrometry: a study of quaternary ammonium pesticides
Authors: Evans Catherine S. , Startin James R. , Goodall David M. , Keely Brendan J. 
Published: September 2002

AbstractGas‐phase cluster formation between the quaternary ammonium pesticides paraquat, diquat, difenzoquat, chlormequat and mepiquat, and chloride and acetate anions present in a liquid chromatography (LC) mobile phase, has been studied using electrospray mass spectrometry. The clusters of paraquat, mepiquat and chlormequat were revealed over the entire m/z range of the mass spectrometer, and their formation is dependent on the concentrations of both the cationic and the anionic species. Mepiquat and chlormequat form clusters of the type [2Mq+ + A−]+, where Mq+ is the quaternary ammonium cation and A− is the anion. Paraquat forms a cluster species with ammonia and also an ion‐pair complex with chloride anions. Diquat and difenzoquat did not form observable ion‐pair complexes or clusters with any of the anions studied. Competitive binding of acetate and chloride anions reflects the higher charge density of chloride, which forms the dominant clusters with mepiquat and chlormequat. The formation of cluster species has implications for the quantification of quaternary ammonium pesticides and may have an influence on the linearity of calibrations. Copyright © 2001 John Wiley & Sons, Ltd.
Composition and structure of enriched alloy layers in filmed Al alloys studied by medium‐energy ion scattering
Authors: Bailey P. , Skeldon P. , Noakes T. C. Q. , Thompson G. E. , Sakairi M. , Habazaki H. , Shimizu K. 
Published: September 2002

AbstractThe topmost 20 nm of an electropolished Al–1 at.% Cu alloy has been investigated at sub‐nanometre resolution using medium‐energy ion scattering. Differences in the composition and depth of the enriched Cu layer are observed. Most significantly, the enriched layer contains regions of differing structure and/or lattice orientation with Cu atoms located in distinct ordered regions, consistent with the presence of Cu‐rich clusters. Surface‐segregated Si and Cu are observed and Cl and Cu are found in the oxide. Copyright © 2001 John Wiley & Sons, Ltd.
Nanopore and nanoparticle catalysts
Authors: Thomas John Meurig , Raja Robert 
Published: September 2002

AbstractThe design, atomic characterization, performance, and relevance to clean technology of two distinct categories of new nanocatalysts are described and interpreted. Exceptional molecular selectivity and high activity are exhibited by these catalysts. The first category consists of extended, crystallographically ordered inorganic solids possessing nanopores (apertures, cages, and channels), the diameters of which fall in the range of about 0.4 to about 1.5 nm, and the second of discrete bimetallic nanoparticles of diameter 1 to 2 nm, distributed more or less uniformly along the inner walls of mesoporous (ca. 3 to 10 nm diameter) silica supports. Using the principles and practices of solid‐state and organometallic chemistry and advanced physico‐chemical techniques for in situ and ex situ characterization, a variety of powerful new catalysts has been evolved. Apart from those that, inter alia, simulate the behavior of enzymes in their specificity, shape selectivity, regio‐selectivity, and ability to function under ambient conditions, many of these new nanocatalysts are also viable as agents for effecting commercially significant processes in a clean, benign, solvent‐free, single‐step fashion. In particular, a bifunctional, molecular sieve nanopore catalyst is described that converts cyclohexanone in air and ammonia to its oxime and caprolactam, and a bimetallic nanoparticle catalyst that selectively converts cyclic polyenes into desirable intermediates. Nanocatalysts in the first category are especially effective in facilitating highly selective oxidations in air, and those in the second are well suited to effecting rapid and selective hydrogenations of a range of organic compounds. © 2001 John Wiley & Sons, Inc. and The Japan Chemical Journal Forum Chem Rec 1:448–466, 2001
Vectors and gene targeting modules for tandem affinity purification in Schizosaccharomyces pombe
Authors: Tasto Joseph J. , Carnahan Robert H. , Hayes McDonald W. , Gould Kathleen L. 
Published: September 2002

AbstractWe describe the construction of tagging cassettes and plasmids for tandem affinity purification (TAP) of proteins in Schizosaccharomyces pombe. The tagging cassettes are designed for either carboxy‐ or amino‐terminal tagging of proteins. The carboxyl terminal tags differ in that they contain either two or four repeats of IgG binding units. For tagging endogenous loci, the cassettes contain the kan MX6 module to allow for selection of G418‐resistant cells. The amino‐terminal tagging vectors allow for the regulated expression of proteins. Sz. pombe Cdc2p was chosen to test these new affinity tags. Several known binding proteins co‐purified with both Cdc2p‐CTAP and N‐TAP‐Cdc2p, indicating the usefulness of these tags for the rapid purification of stable protein complexes from Sz. pombe. Copyright © 2001 John Wiley & Sons, Ltd.
Efficient expression, purification and characterization of mouse salivary α‐amylase secreted from methylotrophic yeast, Pichia pastoris
Authors: Kato Shinya , Ishibashi Matsujiro , Tatsuda Daisuke , Tokunaga Hiroko , Tokunaga Masao 
Published: September 2002

AbstractWe constructed a secretion vector of mouse salivary α‐amylase, pPAM, using the AOX1 promoter‐terminator and the secretion signal of 128 kDa pGKL killer protein, for an alternative yeast, Pichia pastoris. Taking advantage of multicopy insertion of the expression cassette and optimized growth conditions, we succeeded in highly efficient extracellular production (∼240 µg/ml) of mouse α‐amylase in the 10 ml scale by conventional flask culture: this efficiency was about 90‐fold higher than that of Saccharomyces cerevisiae. Growth temperature of cells was critical for efficient production of α‐amylase. P. pastoris transformants secreted both core‐glycosylated and non‐glycosylated α‐amylase molecules with a glycosylated:non‐glycosylated ratio of about 20:80. Both glycosylated and non‐glycosylated α‐amylases were purified separately to apparent homogeneity. The signal sequence was correctly processed in both species, and the molecular masses of glycosylated and non‐glycosylated α‐amylase were determined to be 58 600 and 56 300, respectively, by mass spectrometry. We further studied the outer chain glycosylation of engineered mouse α‐amylase secreted by P. pastoris. Copyright © 2001 John Wiley & Sons, Ltd.