bluuebunny/crossref_metadata_2025_split huggingface dataset:
Epidemiological approach to the paleopathological diagnosis of leprosy
Authors: Boldsen Jesper L. 
Published: August 2002

AbstractIn paleopathology it is usually assumed that modern diagnostic criteria can be applied to infectious diseases in the past. However, as both the human species and populations of pathogenic microorganisms undergo evolutionary changes, this assumption is not always well‐founded. To get valid estimates of the frequency (the point prevalence at death) of leprosy in skeletal samples, sensitivity, specificity, and sample frequency must be estimated simultaneously. It is shown that more than three symptoms must be evaluated in at least three samples in order to reach estimates with well‐described properties. The method is applied to three skeletal samples from Medieval Denmark; the samples were scored for the presence of seven osteological conditions indicating leprosy. For the osteological conditions, sensitivity varied from 0.36–0.80, and specificity from 0.58–0.98. The frequency of leprosy in the three samples was: Odense (a lepers' institution), 0.98, 95% CI 0.64–1.00; Malmö (urban cemetery), 0.02, 95% CI 0.00–0.07; and Tirup (rural cemetery), 0.36, 95% CI 0.23–0.46. It is concluded that it is indeed possible to estimate disease frequencies without reference to modern standards, and that leprosy occurred with widely differing frequencies in different segments of the Medieval population in southern Scandinavia. Am J Phys Anthropol 115:380–387, 2001. © 2001 Wiley‐Liss, Inc.
Phenobarbital and MK‐801, but not phenytoin, improve the long‐term outcome of status epilepticus
Authors: Prasad Avinash , Williamson John M. , Bertram Edward H. 
Published: August 2002

AbstractTo examine the effect of therapy on status epilepticus (SE) acutely and on long‐term outcome, we compared three drugs with three different mechanisms. Phenobarbital, MK‐801, and phenytoin were administered at 1, 2, and 4 hours after initiation of limbic status epilepticus by “continuous” hippocampal stimulation in rats. We evaluated the effects of these drugs on the course of SE and the subsequent development of chronic epilepsy. Phenobarbital and MK‐801 were superior to phenytoin in suppressing SE and in preventing chronic epilepsy. There was no benefit if treatment was given 2 hours after the initiation of SE. Phenobarbital was most effective in suppressing electrographic seizure activity, but MK‐801 had a slightly wider window for the prevention of chronic epilepsy. Early treatment, rather than electrographic suppression of SE, correlated with prevention of chronic epilepsy. This study shows that the drugs administered, which have different mechanisms of action, have clear differences in altering the outcomes. The findings suggest that studies of SE treatment should examine the effect of therapy on SE itself, as well as the long‐term benefits of each treatment. The use of N‐methyl‐D‐aspartate receptor antagonists should be considered early in the treatment of SE.
Nemaline myopathy: A clinical study of 143 cases
Authors: Ryan Monique M. , Schnell Christina , Strickland Corinne D. , Shield Lloyd K. , Morgan Graeme , Iannaccone Susan T. , Laing Nigel G. , Beggs Alan H. , North Kathryn N. 
Published: August 2002

AbstractWe report 143 Australian and North American cases of primary nemaline myopathy. As classified by the European Neuromuscular Centre guidelines, 23 patients had severe congenital, 29 intermediate congenital, 66 typical congenital, 19 childhood‐onset, and 6 adult‐onset nemaline myopathy. Inheritance was autosomal recessive in 29 patients, autosomal dominant in 41, sporadic in 72, and indeterminate in 1. Twenty‐two patients had skeletal muscle actin mutations and 4 had mutations in the α‐tropomyosinSLOW gene. Obstetric complications occurred in 49 cases. Seventy‐five patients had significant respiratory disease during the first year of life, and 79 had feeding difficulties. Atypical features in a minority of cases included arthrogryposis, central nervous system involvement, and congenital fractures. Progressive distal weakness developed in a minority of patients. Thirty patients died, the majority during the first 12 months of life. All deaths were due to respiratory insufficiency, which was frequently underrecognized in older patients. Arthrogryposis, neonatal respiratory failure, and failure to achieve early motor milestones were associated with early mortality. Morbidity from respiratory tract infections and feeding difficulties frequently diminished with increasing age. Aggressive early management is warranted in most cases of congenital nemaline myopathy.
Synthesis and characterization of soluble polypyrrole with improved electrical conductivity
Authors: Lee G. J. , Lee S. H. , Ahn K. S. , Kim K. H. 
Published: August 2002

AbstractPolypyrroles doped with two dopants were prepared by chemical polymerization in aqueous solutions of pyrrole monomer. The solutions contained dodecylbenzenesulfonic acid (DBSA) as a dopant, tetraethylammonium tetrafluoroborate (TEABF4) as a codopant, and ammonium persulfate (APS) as an oxidant. The PPy composites [polypyrrole‐dodecylbenzenesulfonates (PPy‐DBS) codoped with tetrafluoroborate (BF)—PPy‐DBS‐BF] were soluble in m‐cresol, NMP, and conditionally soluble in chloroform. Cyclic voltammetry was measured to know the electrochemical property of PPy‐DBS‐BF. The maximum electrical conductivity of room temperature for PPy‐DBS‐BF is 1.18 s/cm, which is greatly higher than that of polypyrrole doped with DBS− (0.04 s/cm). The composition and structural characterization of PPy‐DBS‐BF were inferred from elemental analysis, nuclear magnetic resonance, and Fourier transform infrared spectroscopy. Scanning electron microscopy was performed to know the morphology of PPy‐DBS‐BF. The results of UV‐Vis spectra and electron spin resonance measurements showed that polaron and bipolaron existed as charge carrier of soluble PPy‐DBS‐BF. From the temperature dependence of the electrical conductivity, it was suggested that possible conduction mechanism for soluble PPy‐DBS‐BF should be hopping conduction. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2583–2590, 2002
Study on synthesis and thermal properties of polyurethane–imide copolymers with multiple hard segments
Authors: Liu Jin , Ma Dezhu 
Published: August 2002

AbstractDifferent multiple hard segment polyurethane–imide copolymers (MHPUI) were synthesized and characterized. FTIR spectroscopy confirmed the characteristic absorption of the MHPUI copolymer. The difference in the imide group FTIR absorption bands in different MH segment PUI copolymers was found in this study and was explained by the different MH segment types, hard segment contents, and hard segment rigidity with different interactions of the molecular chains. The hard segment interaction in MHPUI with an increase of the structure rigidity of the short hard segments is strengthening. The DSC analysis revealed that the glass‐transition temperature of the soft segment of PUI rose in value from −42 to −3.4°C with the introduction of MH and different MH segments. The DSC results suggest that the soft segment is more compatible with the hard segment rigidity increase. The TGA results showed the hard segment structure symmetry has a more important role in the MHPUI thermal stability. Every sample containing symmetrical structure short hard groups (4,4′‐diphenylmethane diisocyanate or 4,4′‐diaminodiphenylmethane) is more thermally stable than that with worse symmetry structure groups (2,4‐toluene diisocyanate or 3,3′‐dichloro‐4,4′‐diamino‐diphenylmethane). The three‐step mechanism of PUI thermal degradation was further verified by the TGA study. The thermally unstable group was confirmed as urethane or a urea–urethane segment. The TGA results showed that MHPUI copolymers with higher separation of the soft–hard phase have higher thermal stability. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2206–2215, 2002
Polymerized high internal‐phase emulsions: Properties and interaction with water
Authors: Sergienko Anatoly Y. , Tai Huiwen , Narkis Moshe , Silverstein Michael S. 
Published: August 2002

AbstractThe synthesis and characterization of novel polymerized high internal‐phase emulsions (polyHIPE) materials are described. Homogeneous, highly porous, low‐density, open‐cell crosslinked copolymers were prepared by polymerizing the continuous phase of HIPE containing styrene and varying amounts of 2‐ethylhexyl methacrylate. The glass transition temperatures (Tgs) of the homopolymers were similar to the literature values, but the copolymer Tgs were lower than expected. These results indicate that the copolymer composition is richer in 2‐ethylhexyl methacrylate than the feed composition. The homopolymer moduli, calculated from the foam moduli, were similar to the literature values. The influence of composition and surface treatment on the water absorbed by the foams was investigated. For example, washing a polyHIPE based on poly(ethylhexyl acrylate) in water at 70°C increased water absorption because of the removal of the residual salt. Adding a fluorinated comonomer to the HIPE reduced hydrophilicity and, thus, water absorption. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2018–2027, 2002; DOI 10.1002/app.10555
Toughness enhancement of high‐impact polystyrene based on γ‐radiation vulcanized natural rubber latex by using block copolymer
Authors: Sangribsub S. , Tangboriboonrat P. 
Published: August 2002

AbstractPolyisoprene‐block‐polystyrene‐block‐polyisoprene (ISI) was synthesized by the iniferter route and its use, as compared to a commercial polystyrene‐block‐polyisoprene‐block‐polystyrene (SIS), in the enhancement of the toughness of high‐impact polystyrene (HIPS), prepared by the γ‐radiation vulcanized natural rubber (RVNR) latex/phase transfer/bulk polymerization technique, was investigated. Addition of 5% SIS was adequate as an interfacial agent, which effectively increased the unnotched Izod impact energy of HIPS, whereas use of 10% of ISI was required. A long polyisoprene block with two polystyrene segments of SIS was favorable for compatibilization of HIPS. Transmission electron micrographs revealed the uniform distribution of the block copolymer at the shell region of the rubber particle. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1307–1316, 2002
Function mechanisms of polyamines in rosin sizing under neutral papermaking conditions
Authors: Wu Zonghua , Chen Shaoping , Tanaka Hiroo 
Published: August 2002

AbstractThe surface analyses of the papers sized with a rosin emulsion (RE) and five typical polyamines, polyallylamine (PAAm), polyvinylamine (PVAm), polyethyleneimine (PEI), poly(diallyldimethylammonium chloride (PDADMAC), and poly(dimethylamino ethyl methacrylate) (PDMAEMA), were performed using a X‐ray photoelectron spectrometer. The results show that the chemical states of the polyamines on the outermost surfaces of the papers changed significantly during the neutral rosin sizing. The five polyamines could react with carboxyl groups of the fibers to form urethane linkages at 400.0 ± 0.1 eV, which resulted in absorption of the polyamines onto the fibers. Only PAAm and PVAm could combine with RE to form urethane linkages at 400.7–0.1 eV, which were related deeply to sizing effectiveness. The polyamines distributed mainly on the surfaces of the fibers. The concentrations of PAAm and PVAm on the surfaces of the sized papers were much larger than those of PEI, PDMAEMA, and PDADMAC. A larger sizing degree was related to a larger C1 component at 285.0 eV (CC) in the C1s XPS spectra of the sized papers. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2185–2190, 2001
Structural, mechanical, and electrical properties of electropolymerized polypyrrole composite films
Authors: Bhat N. V. , Gadre A. P. , Bambole V. A. 
Published: August 2002

AbstractElectrochemical polymerization of pyrrole in a solution containing dissolved poly(vinyl alcohol) (PVA) produces a homogeneous, free‐standing, flexible, and conductive polymer film. The films were characterized using infrared spectroscopy, wide‐angle X‐ray diffraction analysis, and scanning electron microscopy. The appearance of standard and some new absorption bands for polypyrrole (PPy) and PVA confirms the composite formation. The mechanical properties of conducting PVA + PPy films were studied and found to be improved with respect to the control PPy films. The electrical conductivity of the PVA + PPy films was measured by using standard four‐ and two‐probe methods. The conductivity of the films was found to depend on the pyrrole content. These conducting composites were further used as gas sensors by observing the change in current with respect to ammonia gas. It was observed that the current decreases when these composites were exposed to ammonia gas. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2511–2517, 2001
Thermal characterization of three‐component blends for hot‐melt adhesives
Authors: Fernandes E. G. , Lombardi A. , Solaro R. , Chiellini E. 
Published: August 2002

AbstractTraditional solvent‐based adhesives used in the footwear industry have been demonstrated as harmful to the workers' health and environment. Solvent‐free three‐component adhesives (hot‐melt adhesives or HMAs) for various applications including the leather and footwear industry are becoming more and more attractive. Thus, the formulation of a three‐component HMA was realized in this study. Thermogravimetry, differential scanning calorimetry, and the apparent strength of the adhesive bond were used to investigate the relationship between their properties and the polymer/wax/resin compositions. The thermal stability of HMA formulations was determined and compared with thermal traces based on an additive weight computation of the single components' thermal profiles. All HMA formulations showed a direct relationship between the glass‐transition temperature and the apparent adhesive shear strength at the leather–rubber interface. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2889–2901, 2001
Preparation of poly(acrylic acid)/poly(vinyl alcohol) membrane for the facilitated transport of CO2
Authors: Matsuyama Hideto , Teramoto Masaaki , Matsui Kenji , Kitamura Yoshiro 
Published: August 2002

AbstractPoly(acrylic acid) (PAA)/poly(vinyl alcohol) (PVA) membrane was prepared for the facilitated transport of CO2. The carrier of CO2 was monoprotonated ethylenediamine and was introduced in the membrane by ion exchange. The ion‐exchange capacity of the membrane was 4.5 meq/g, which was much higher than that of the Nafion 117 membrane. The membrane was highly swollen by the aqueous solution. Much higher selectivity of CO2 over N2 and higher CO2 permeability were obtained in the PAA/PVA membrane than in the Nafion membrane because of the higher ion‐exchange capacity and solvent content. The highest selectivity was more than 1900 when the CO2 partial pressure in the feed gas was 0.061 atm. Effects of ion‐exchange capacity, membrane thickness, and annealing temperature in conditions of membrane preparation on membrane performance were investigated. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 936–942, 2001
Supercritical carbon dioxide dewaxing of old corrugated containers
Authors: Stauffer Thad C. , Venditti Richard A. , Gilbert Richard D. , Kadla John F. , Chernyak Yury , Montero Gerardo A. 
Published: August 2002

AbstractWax‐coated old corrugated containers (OCC) are not part of the paper recycling stream because a process to remove the wax coating is not presently available. Residual waxes influence fiber–fiber bonding, reducing the paper properties of recycled OCC as well as the paper machine operating efficiency. A procedure to dewax OCC is a major objective of the paper industry. Here we describe a novel process to quantitatively dewax OCC by using supercritical carbon dioxide to remove the wax. The results obtained for the extraction of both saturated and curtain‐coated waxed containers are reported and compared with Soxhlet extraction with hexane. Quantitative removal of the waxes was obtained under a variety of operating conditions. Gas chromatographic analysis of the extracted paraffin wax shows that supercritical fluid extraction does not chemically alter the paraffin wax, indicating the recovered wax may be recycled. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1107–1114, 2001
Effect of the composition profile of 2‐ethyl hexyl acrylate/methyl methacrylate latex particles on adhesion
Authors: Laureau C. , Vicente M. , Barandiaran M. J. , Leiza J. R. , Asua J. M. 
Published: August 2002

AbstractThe adhesive properties (tack, shear, and peel) of 2‐ethyl hexyl acrylate/methyl methacrylate copolymer latex particles of different composition profiles (constant, positive, and negative gradients) but similar molecular weight distributions were studied. The composition profile had a strong effect on tack in the region of low molecular weights (weight‐average molecular weight ≤ 100,000 g/mol), but this effect was less important for higher molecular weights. No effect of the composition profile on shear or peel was observed for low‐molecular‐weight latices; nevertheless, for higher molecular weights (400,000 g/mol), resistance to shear strongly increased as heterogeneity increased, and resistance to peel was higher for gradient profiles. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1258–1265, 2001
Polymerization of pyrrole and processing of the resulting polypyrrole as blends with plasticised PVC
Authors: Abraham D. , Jyotsna T. S. , Subramanyam S. V. 
Published: August 2002

AbstractPolypyrrole was synthesized by chemical oxidation of pyrrole in water containing various sulphonic acids like toluene sulphonic acid (TSA), sulphosalicylic acid (SSA), and camphor sulphonic acid (CSA), as well as a combination of each sulphonic acid with sodium dodecyl benzene sulphonate (NaDBS) to investigate the effect of doping on conductivity, yield, and processability of the conducting polymer. Free‐standing blend films of polypyrrole and plasticized polyvinyl chloride (PVC) were obtained by casting an homogeneous suspension of the two polymers in tetrahydrofuran. The maximum conductivity of the blend film is ∼ 0.3 S/cm, corresponding to a weight fraction of 0.16 w/w polypyrrole. The blend film is semiconducting in the range 300–10 K. A TG‐DTA scan indicates the blend film to be amorphous with a stepwise decomposition process similar to pristine PVC. The choice of a dual dopant system during synthesis and the plasticised polymer during subsequent processing were keys to obtaining homogeneous high‐quality films. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1544–1548, 2001
Mooney scorch time and cure index of epoxidized natural rubber in presence of sodium carbonate
Authors: Poh B. T. , Tan E. K. 
Published: August 2002

AbstractThe effect of sodium carbonate on the Mooney scorch time and cure index of epoxidized natural rubber (ENR 50) was studied with concentrations of 0–2 phr and 100–160°C temperatures. A conventional vulcanization system based on an ASTM formulation was used throughout the investigation on the gum and carbon black filled rubber compound. The results indicated that the scorch time and cure index for the gum and filled compounds increased to a maximum value at 0.15 phr of sodium carbonate, and further loading of sodium carbonate caused it to decrease. This observation was attributed to the neutralization of the residual acid in ENR 50 in the initial stage, thus reducing the formation of ether crosslinks via an acid‐catalyzed ring‐opening reaction with the epoxide group in ENR 50. However, as the sodium carbonate was increased beyond 0.15 phr, the excess sodium carbonate enhanced the vulcanization rate as shown by the drop of the scorch time and cure index. The peak maximum was more evident at lower temperature and its peak height decreased with increasing temperature, suggesting that the neutralization effect by sodium carbonate was overshadowed by the faster cure rate resulting from the availability of thermal energy to overcome the activation energy of vulcanization as the temperature was elevated. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1352–1355, 2001
Epoxy–urethane copolymers: Relation between morphology and properties
Authors: Stefani P. M. , Moschiar S. M. , Aranguren M. I. 
Published: August 2002

AbstractThe modification of an amine‐cured epoxy resin by the addition of polyurethanes (PU) was investigated, and their mechanical and impact properties were related to their microstructure and morphology. For the study, two different PU were selected: a commercial sample, D12, with a NCO : OH ratio equal to 2 and end blocked by reaction with an alkylphenol; and a synthesized sample, with NCO : OH ratio equal to 1 and equally end blocked in our laboratory. The usual trend of improved toughening and reduced modulus, EF, and compression yield stress, σYC, was observed in all samples. However, the toughening of the D12‐modified samples was larger for the same initial rubber content. This result correlates with a finer rubber particle separation, but also the ductilization effect that this rubber has on the epoxy‐rich phase. D12 co‐reacts with the epoxy–amine, leading to a lower glass transition temperature (Tg) of the modified system and incomplete phase separation, as observed by scanning electron microscopy. The practically unreactive PU1 rubber leads to the usual spherical inclusion morphology observed in modified epoxies, except at 20% rubber content. The particular morphology generated in this case, co‐continuous epoxy‐rich and rubber‐rich regions, leads to a material with the largest toughening in this study, but also with an impressive reduction in mechanical properties. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2544–2552, 2001
Effect of the ethylene content of poly(ethylene‐co‐vinyl alcohol) on the formation of microporous membranes via thermally induced phase separation
Authors: Matsuyama Hideto , Kobayashi Kiyotaka , Maki Taisuke , Tearamoto Masaaki , Tsuruta Hitoshi 
Published: August 2002

AbstractPorous poly(ethylene‐co‐vinyl alcohol) (EVOH) membranes were prepared via thermally induced phase separation. The effect of the EVOH ethylene content on the membrane morphology and solute rejection property was investigated. For EVOHs with ethylene contents of 27–44 mol %, polymer crystallization (solid–liquid phase separation) occurred, and the membrane morphology was the particulate structure. However, the liquid–liquid phase separation occurred before crystallization for EVOH with a 60 mol % ethylene content. Cellular pores were formed in this membrane. For the particulate membranes, higher solute rejection and lower water permeance were obtained for EVOH with a lower ethylene content. The membrane formed by the liquid–liquid phase separation showed a sharper solute rejection change with a change in the solute radius than the particulate membranes did. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2583–2589, 2001