bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transient and athermal effects in the crystallization of polymers. I. Isothermal crystallization
Authors: Sajkiewicz Paweł 
Published: October 2002

AbstractThe isothermal crystallization of poly(propylene) and poly(ethylene terephthalate) was investigated with differential scanning calorimetry and optical microscopy. It was found that the induction time depends on the cooling rate to a constant temperature. The isothermal crystallization of the investigated polymers is a complex process and cannot be adequately described by the simple Avrami equation with time‐independent parameters. The results indicate that crystallization is composed of several nucleation mechanisms. The homogeneous nucleation occurring from thermal fluctuations is preceded by the nucleation on not completely melted crystalline residues that can become stable by an athermal mechanism as well as nucleation on heterogeneities. The nucleation rate depends on time, with the maximum shortly after the start of crystallization attributed to nucleation on crystalline residues (possible athermal nucleation) and on heterogeneities. However, the spherulitic growth rate and the exponentndo not change with the time of crystallization. The time dependence of the crystallization rate corresponds to the changes in the nucleation rate with time. The steady‐state crystallization rate in thermal nucleation is lower than the rate determined in a classical way from the half‐time of crystallization. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1835–1849, 2002
Thermal lensing in poly(vinyl alcohol)/polyaniline blends
Authors: Pilla V. , Catunda T. , Balogh D. T. , Faria R. M. , Zilio S. C. 
Published: October 2002

AbstractNonlinear optical properties of poly(vinyl alcohol) (PVA)/polyaniline (PAni) blends were measured with the single‐beam Z‐scan technique with Fourier analysis. The results obtained with continuous wave (cw) excitation indicated that the self‐phase modulation had a thermal origin. Besides the Z‐scan technique, we also employed the time‐resolved mode‐mismatched thermal lens (TL) technique to obtain the temperature coefficient of the optical path length, ds/dT, and the thermal diffusivity coefficient, D, for the specific concentrations used in our blends. ds/dT varied between −0.8 and −1.0 × 10−4 K−1, whereas the thermal diffusivity varied between 1.0 and 1.3 × 10−3 cm2/s. The TL technique was further used to study the aging of the blends as they were heated to 90 °C. Unlike the electrical conductivity of PAni films, which presented a strong dependence on the doping level, the thermooptic properties presented only a slight variation with doping. This feature indicated that the PVA/glutaraldehyde network made the main contribution to the thermooptic properties (D and ds/dT) in the PAni blends. Similarly, dimethyl sulfoxide as a solvent determined the thermooptic properties of PAni solutions. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1949–1956, 2002
Crystallization mechanism of regioregular poly(3‐alkyl thiophene)s
Authors: Malik Sudip , Nandi Arun K. 
Published: October 2002

AbstractThe crystallization properties of three regioregular poly(3‐alkyl thiophene)s (P3ATs) are studied: poly(3‐hexyl thiophene) (P3HT), poly(3‐octyl thiophene) (P3OT), and poly(3‐dodecyl thiophene) (P3DDT). The morphology of the isothermally crystallized samples is a whisker type. The values of the enthalpy of fusion of ideal crystals (ΔH), determined from the melting point depression in the polymer–diluent system, are 99, 73.6, and 52 J/g for P3HT, P3OT, and P3DDT, respectively. The values of the equilibrium melting point (T), determined from the Hoffman–Weeks extrapolation procedure, are 300, 230, and 180 °C for P3HT, P3OT, and P3DDT, respectively. From the linear extrapolation of the P3AT data, the T and ΔH values of unsubstituted polythiophene are predicted to be 400 °C and 139 J/g, respectively. The crystallization kinetics of these polymers are studied with differential scanning calorimetry, and the Avrami exponents vary between 0.6 and 1.4, indicating one‐dimensional heterogeneous nucleation with linear growth. As the P3AT whiskers are produced from the chain‐folding process, the Lauritzen–Hoffman growth rate theory is applied to analyze the temperature coefficient of the crystallization rate data. Graphical plots indicate a transition from regime I to regime II during isothermal crystallization for all the P3ATs studied. The fold surface energy and the work of chain folding calculated from the slopes of the graphical plots decrease with an increase in the number of carbon atoms of the side chain. The primary crystallization process of the side‐chain crystallization is very fast and is attributed to the zipping effect of the main‐chain crystals. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2073–2085, 2002
A POMS short form for cancer patients: psychometric and structural evaluation
Authors: Baker Frank , Denniston Maxine , Zabora James , Polland Adrienne , Dudley William N. 
Published: October 2002

AbstractThe internal consistency, validity, and factor structure of the Shacham shortened version (37 items) of the 65‐item profile of mood states (POMS) were examined with a sample of 428 cancer patients who were awaiting bone marrow transplantation. Cronbach's alphas ranging from 0.78 to 0.91 were obtained for each of the six subscales of the POMS‐short form (POMS‐SF) and for the total 37‐item scale. Correlations with the CES‐D, the Self‐Rated Karnofsky, the MOS SF‐20 Physical Functioning, and the Bradburn Positive and Negative Affect Scales provided evidence of the convergent and discriminant validity of the POMS‐SF. Results of a confirmatory factor analysis were supportive of the 6‐factor interpretation of the POMS items in the 37‐item version of the POMS. Copyright © 2002 John Wiley & Sons, Ltd.
Geomorphic processes at a snowpatch hollow on Gassan volcano, northern Japan
Authors: Kariya Yoshihiko 
Published: October 2002

AbstractPresent‐day geomorphic processes, in a snowpatch hollow on an andesitic volcano (Gassan, 1984 m ASL; 38° 38′ N, 140° 02′ E) where late‐lying snow survives nearly 10 months every year, have been measured for several years. Although soil temperature data show a concentration of freeze‐thaw activities in autumn, these fluctuations rarely drop to the effective temperature range for frost shattering. Wetting and drying rather than frost action is thought responsible for debris production which ranges from 2.12 to 49.68 g m−2 a−1, equivalent to a rock surface retreat of 0.001 to 0.019 mm a−1. Thawing of seasonal frost and saturation of soils induces frost creep and gelifluction: maximum values of surface velocity and depth of soil movement are 0.9 cm a−1 and 14 cm, respectively. Annually, slope lowering of 0.3 cm occurs in the pro‐nival and sub‐nival wash‐rill zones. In comparison with other snowpatch sites in the world, rates of soil movement and rock surface denudation are considerably lower at the study site, while fluvial action seems important. Copyright © 2002 John Wiley & Sons, Ltd.
The mean annual temperature at the top of permafrost, the TTOP model, and the effect of unfrozen water
Authors: Riseborough D. W. 
Published: October 2002

AbstractThe effect of unfrozen water content on the thermal properties of the ground is discussed in the context of the TTOP model. In soils with a significant freezing characteristic the ratio of unfrozen and frozen conductivities is not single‐valued, which is an assumption of the TTOP model. Numerical simulations of the thermal regime for a range of fine‐grained soils are used to determine the effect of variable soil conductivity on the temperature at the top of permafrost. Results show that the temperature dependent conductivity function can be used with a temperature based on the surface freezing index to estimate an appropriate single value of the frozen conductivity for use in the TTOP model. Copyright © 2002 John Wiley & Sons, Ltd.
Flexible fiberoptic bronchoscopic removal of a fractured synthetic tracheostomy tube in a 3‐year‐old child
Authors: Ng Daniel K. , Cherk Sharon W. , Law Albert K. 
Published: October 2002

AbstractWe report on a 3‐year‐old boy, who was tracheotomized for prolonged ventilatory support in response to respiratory failure due to spinal muscular atrophy. He aspirated a fractured synthetic tracheostomy tube. It was successfully removed by flexible fiberoptic bronchoscopy. Pediatr Pulmonol. 2002; 34:141–143. © 2002 Wiley‐Liss, Inc.
Prognostic factors in cystic fibrosis in a single center in Brazil: A survival analysis
Authors: Oliveira Maria Christina Lopes A. , Reis Francisco José C. , Oliveira Eduardo A. , Colosimo Enrico A. , Monteiro Ana Paula A.F. , Penna Francisco José 
Published: October 2002

AbstractThe purpose of the present study was to identify prognostic factors related to death in patients with cystic fibrosis (CF). Records of 127 patients with CF submitted to a systematic protocol were retrospectively reviewed. Prognostic factors associated with demographic, nutritional, clinical, and laboratory findings on admission were studied. The median follow‐up was 44 months. The analysis was conducted in two steps. First, in a univariate analysis, variables associated with death outcome were identified by the log‐rank test. Then the variables that were significantly associated with adverse outcome were included in a multivariate analysis. This analysis, using the Cox proportional hazards model, was performed to identify variables that were independently associated with a worse prognosis. Only variables that remained independently associated with adverse outcome were included in the final model.Three variables were identified as independent predictors of adverse outcome: age at diagnosis under 3 months (relative risk (RR) = 13, 95% CI = 4.5–34,P < 0.001); Shwachman‐Kulczycki (S‐K score) score below 70; and birth weight under 3,000 g. An interaction effect between S‐K score and birth weight was identified. The relative risk of death for the S‐K score was 24 (95% CI = 3–195) when birth weight was lower than 3,000 g; on the other hand, when birth weight was 3,000 g or more, the relative risk for the S‐K score was 1.4 (95% CI = 0.24–8.83).The combination of three factors (low S‐K score, low birth weight, and young age at diagnosis) is indicative of a poor prognosis in CF patients. Pediatr Pulmonol. 2002; 34:3–10. © 2002 Wiley‐Liss, Inc.
Mutational analysis of ETV6 in prostate carcinoma
Authors: Kibel Adam S. , Faith Dennis A. , Bova G. Steven , Isaacs William B. 
Published: October 2002

AbstractBACKGROUNDIn an effort to better understand the molecular events responsible for progression of prostate carcinoma to metastatic disease, we have recently identified a homozygous deletion at 12p12‐13 involving ETV6 (tel). Although mutational analysis of ETV6 has not been examined previously in prostate carcinoma, it is an attractive candidate prostate cancer tumor suppressor gene since as it previously has been implicated in malignancy. Therefore, we decided to analyze 43 prostate cell lines, xenografts, and metastatic foci for inactivating mutations.METHODSDNA was isolated from 7 cell lines, 18 xenografts, and 18 metastatic deposits. Single‐strand conformational polymorphism (SSCP) analysis of ETV6, was performed by polymerase chain reaction (PCR) amplification of each exon by using intron specific primers. PCR products were then resolved by gel electrophoresis, and aberrantly migrating PCR products were then sequenced.RESULTSTwo previously described polymorphisms and four novel sequence changes were identified. Polymorphisms at nucleotide 258 (G → A, Thr → Thr) and 602 (T → C, Leu → Pro) were identified in eight and one specimen(s), respectively. Analysis of noncancerous DNA confirmed the presence of the polymorphisms in the germ‐line. Four possible mutations were identified at nucleotides 24 (T → G, Cys → Trp), 380 (G → A, Arg → Glu), 776 (G → T, Arg → Leu), and 876 (C → T, Leu → Leu). Three were in xenografts or cell lines. Because normal DNA was not available, these could represent rare polymorphisms. The sole mutation in a clinical specimen, at nucleotide 876, did not result in an amino acid change.CONCLUSIONOur data suggest that mutational inactivation ETV6 may occur in prostate carcinoma. The functional significance of these potential inactivating mutations remains to be determined. Prostate 52: 305–310, 2002. © 2002 Wiley‐Liss, Inc.
Local energy landscape flattening: Parallel hyperbolic Monte Carlo sampling of protein folding
Authors: Zhang Yang , Kihara Daisuke , Skolnick Jeffrey 
Published: October 2002

AbstractAmong the major difficulties in protein structure prediction is the roughness of the energy landscape that must be searched for the global energy minimum. To address this issue, we have developed a novel Monte Carlo algorithm called parallel hyperbolic sampling (PHS) that logarithmically flattens local high‐energy barriers and, therefore, allows the simulation to tunnel more efficiently through energetically inaccessible regions to low‐energy valleys. Here, we show the utility of this approach by applying it to the SICHO (SIde‐CHain‐Only) protein model. For the same CPU time, the parallel hyperbolic sampling method can identify much lower energy states and explore a larger region phase space than the commonly used replica sampling (RS) Monte Carlo method. By clustering the simulated structures obtained in the PHS implementation of the SICHO model, we can successfully predict, among a representative benchmark 65 proteins set, 50 cases in which one of the top 5 clusters have a root‐mean‐square deviation (RMSD) from the native structure below 6.5 Å. Compared with our previous calculations that used RS as the conformational search procedure, the number of successful predictions increased by four and the CPU cost is reduced. By comparing the structure clusters produced by both PHS and RS, we find a strong correlation between the quality of predicted structures and the minimum relative RMSD (mrRMSD) of structures clusters identified by using different search engines. This mrRMSD correlation may be useful in blind prediction as an indicator of the likelihood of successful folds. Proteins 2002;48:192–201. © 2002 Wiley‐Liss, Inc.
1.3‐Å resolution structure of human glutathione S‐transferase with S‐hexyl glutathione bound reveals possible extended ligandin binding site
Authors: Le Trong Isolde , Stenkamp Ronald E. , Ibarra Catherine , Atkins William M. , Adman Elinor T. 
Published: October 2002

AbstractCytosolic glutathione S‐transferases (GSTs) play a critical role in xenobiotic binding and metabolism, as well as in modulation of oxidative stress. Here, the high‐resolution X‐ray crystal structures of homodimeric human GSTA1‐1 in the apo form and in complex with S‐hexyl glutathione (two data sets) are reported at 1.8, 1.5, and 1.3Å respectively. At this level of resolution, distinct conformations of the alkyl chain of S‐hexyl glutathione are observed, reflecting the nonspecific nature of the hydrophobic substrate binding site (H‐site). Also, an extensive network of ordered water, including 75 discrete solvent molecules, traverses the open subunit–subunit interface and connects the glutathione binding sites in each subunit. In the highest‐resolution structure, three glycerol moieties lie within this network and directly connect the amino termini of the glutathione molecules. A search for ligand binding sites with the docking program Molecular Operating Environment identified the ordered water network binding site, lined mainly with hydrophobic residues, suggesting an extended ligand binding surface for nonsubstrate ligands, the so‐called ligandin site. Finally, detailed comparison of the structures reported here with previously published X‐ray structures reveal a possible reaction coordinate for ligand‐dependent conformational changes in the active site and the C‐terminus. Proteins 2002;48:618–627. © 2002 Wiley‐Liss, Inc.
Distinguishing native conformations of proteins from decoys with an effective free energy estimator based on the OPLS all‐atom force field and the surface generalized born solvent model
Authors: Felts Anthony K. , Gallicchio Emilio , Wallqvist Anders , Levy Ronald M. 
Published: October 2002

AbstractProtein decoy data sets provide a benchmark for testing scoring functions designed for fold recognition and protein homology modeling problems. It is commonly believed that statistical potentials based on reduced atomic models are better able to discriminate native‐like from misfolded decoys than scoring functions based on more detailed molecular mechanics models. Recent benchmark tests on small data sets, however, suggest otherwise. In this work, we report the results of extensive decoy detection tests using an effective free energy function based on the OPLS all‐atom (OPLS‐AA) force field and the Surface Generalized Born (SGB) model for the solvent electrostatic effects. The OPLS‐AA/SGB effective free energy is used as a scoring function to detect native protein folds among a total of 48,832 decoys for 32 different proteins from Park and Levitt's 4‐state‐reduced, Levitt's local‐minima, Baker's ROSETTA all‐atom, and Skolnick's decoy sets. Solvent electrostatic effects are included through the Surface Generalized Born (SGB) model. All structures are locally minimized without restraints. From an analysis of the individual energy components of the OPLS‐AA/SGB energy function for the native and the best‐ranked decoy, it is determined that a balance of the terms of the potential is responsible for the minimized energies that most successfully distinguish the native from the misfolded conformations. Different combinations of individual energy terms provide less discrimination than the total energy. The results are consistent with observations that all‐atom molecular potentials coupled with intermediate level solvent dielectric models are competitive with knowledge‐based potentials for decoy detection and protein modeling problems such as fold recognition and homology modeling. Proteins 2002;48:404–422. © 2002 Wiley‐Liss, Inc.
Larvicidal activity against Plutella xylostella of cordycepin from the fruiting body of Cordyceps militaris
Authors: Kim Jun‐Ran , Yeon Sung‐Hum , Kim Ho‐San , Ahn Young‐Joon 
Published: October 2002

AbstractThe insecticidal activities of methanol extracts of Cordyceps militaris Link (Ascomycotina: Clavicipitaceae) cultured on fresh pupae of Bombyx mori L against 3rd‐instar larvae of Plutella xylostella L were examined using direct contact application. The larvicidal activity was more pronounced in an extract of C militaris fruiting body than in an extract of the pupae separated from the culture. The biologically active constituent of the Cordyceps fruiting body was characterized as cordycepin (3′‐deoxyadenosine) by spectroscopic analysis. Responses varied according to dose, exposure time and application method. In a leaf‐dipping test, cordycepin at 500 mg litre−1 caused no mortality at 1 DAT (day after treatment) but 78 and 100% mortality at 2 and 4 DAT, respectively, whereas 34 and 88% mortality at 3 and 5 DAT, respectively was observed at 300 mg litre−1. Cordycepin caused body colour change from pale green to dark brown and eventually body lysis. These results suggested that the larvicidal action may be attributable to a direct effect rather than an inhibitory action on chitin synthesis. There was a significant difference in insecticidal activity of cordycepin between leaf dipping (500 mg litre−1) with 100% mortality and topical application (10 µg per larva) with 0% mortality, suggesting that cordycepin has stomach action. Cordycepin merits further study as a potential P xylostella control agent or as a lead compound.© 2002 Society of Chemical Industry
Seed dressings to control slug damage in oilseed rape
Authors: Simms Louise C , Mullins Christopher E , Wilson Michael J 
Published: October 2002

AbstractSlugs are major pests of oilseed rape that are poorly controlled by conventional bait pellets. A series of laboratory experiments investigated the potential of seed‐dressings to control slug damage in this crop. Four compounds: metaldehyde, methiocarb, cinnamamide and 3,5‐dimethoxycinnamic acid (DMCA) were tested at a range of doses for phytotoxicity and ability to reduce damage by Deroceras reticulatum (Müller). Metaldehyde and methiocarb were not phytotoxic at any doses, whereas all doses of cinnamamide and DMCA were. All compounds reduced slug damage, but metaldehyde and methiocarb consistently performed better than cinnamamide and DMCA. Metaldehyde and methiocarb seed‐dressings were compared with baited pellets containing the same active ingredients at recommended field doses. The seed‐dressings protected plants from damage by D reticulatum and Arion subfuscus (Draparnaud) as well as, or better than, baited pellets. We therefore recommend that metaldehyde and methiocarb should be field‐tested as seed dressings to control slugs in oilseed rape.© 2002 Society of Chemical Industry
The ABC of pharmaceutical trial design: some basic principles
Authors: Julious Steven , Zariffa Névine 
Published: October 2002

AbstractThis is a teaching paper intended as a quick introduction to some of the key concepts in the design of pharmaceutical trials for those new to the industry.Since the first ‘modern’ randomized clinical trial was reported in 1948 by the Medical Research Council, clinical trials have become a central component in the assessment of new therapies. The primary objective of any clinical trial is to obtain an unbiased and reliable assessment of a given regimen response independent of any known or unknown prognostic factors. The essential principals of trial design can be thought of as the ABC of allocation at random, blinding and controlled. In addition, the three Rs of endpoint selection – representative, reliability and reproducibility – are relevant in this context.This paper briefly describes the basic concepts for clinical trials and highlights possible points to consider. It draws heavily on the principles highlighted in the International Conference on Harmonisation guidelines as well as recommendations in the CONSORT statement. Copyright © 2002 John Wiley & Sons, Ltd.
Computational resiliency
Authors: Lee Joohan , Chapin Steve J. , Taylor Stephen 
Published: October 2002

AbstractThe notion ofcomputational resiliencyrefers to the ability of a distributed application to tolerate intrusion when under information warfare (IW) attack. This technology seeks an active strengthening of a military mission, rather than protecting its network infrastructure using static defensive measures such as network security, intrusion sensors, and firewalls. Computational resiliency involves the dynamic use of replication, guided by mission policy, to achieve intrusion tolerance so that even undetected attacks do not cause mission failure; however, it goes further to dynamically regenerate replication in response to an IW attack, allowing the level of system assurance to be restored and maintained. Replicated structures are protected through several techniques such as camouflage, dispersion, and layered security policy. This paper describes a prototype concurrent programming technology that we have developed to support computational resiliency and describes how the library has been applied in two prototypical applications. Copyright © 2002 John Wiley & Sons, Ltd.
All linear methods are equal—and extendible to (some) nonlinearities
Authors: Gertler Janos 
Published: October 2002

AbstractSeveral linear methods of residual generation for fault detection and diagnosis are reviewed. The parity relation approach is introduced in some detail, for both additive and parametric faults. The Chow–Willsky scheme, various diagnostic observers and principal component analysis are compared to the additive version. The ‘local approach’ and the least‐squares estimation of parameter changes are shown to be related to the parametric variant. Nonlinear extensions are demonstrated for all the techniques under additive faults. Copyright © 2002 John Wiley & Sons, Ltd.