bluuebunny/crossref_metadata_2025_split huggingface dataset:
Van der Woude syndrome with sensorineural hearing loss, large craniofacial sinuses, dental pulp stones, and minor limb anomalies: Report of a four‐generation Thai family
Authors: Kantaputra Piranit N. , Sumitsawan Yupa , Schutte Brian C. , Tochareontanaphol Chintana 
Published: August 2002

AbstractA four‐generation Thai family affected with Van der Woude syndrome is reported. The disorder appeared to be originally inherited from a person who was half Thai and half Pakistani. The lip lesions found in this family were varied and did not appear to be related to other phenotypes. There were some clinical manifestations possibly specific for the condition in this family. They included sensorineural hearing loss, prominent frontal bone, large frontal/sphenoidal/maxillary sinuses with increased mastoid air cells, long tooth roots, dental pulp stones, ankyloglossia, brachydactyly of hands, brachyphalangy, and hyperphalangy of toes, and single flexion crease of the fifth fingers. Fluorescence in situ hybridization analysis revealed no visible deletion at a 1q32‐41 region. © 2002 Wiley‐Liss, Inc.
Deconstructing death in paleodemography
Authors: Konigsberg Lyle W. , Frankenberg Susan R. 
Published: August 2002

AbstractIn 1992 in this Journal (Konigsberg and Frankenberg [1992] Am. J. Phys. Anthropol.89:235–256), we wrote about the use of maximum likelihood methods for the “estimation of age structure in anthropological demography.” More specifically, we presented a particular method (the “iterated age‐length key”) from the fisheries literature and suggested that the method could be used in human and primate demography and paleodemography as well. In our paper (section titled “Some Future Directions”), we spelled out two broad areas that we expected to see develop over the ensuing years. First, we felt that the use of explicit likelihood methods would open up interest in basic estimation issues, such as the calculation of standard errors for demographic estimates and the formulation of tests for whether samples differed in their demographic structure. Second, we felt that the time was ripe for hazards analyses that would incorporate the uncertainty in estimation that follows from using age “indicators” rather than known ages. While some of these developments have occurred during the last decade, few have been reported in theAmerican Journal of Physical Anthropology. In this paper we resolve some issues from our 1992 paper, and attempt to redress this deficit in the literature by reviewing some recent developments in paleodemography over the past decade. Am J Phys Anthropol 117:297–309, 2002. © 2002 Wiley‐Liss, Inc.
Plasticity of language networks in patients with brain tumors: A positron emission tomography activation study
Authors: Thiel Alexander , Herholz Karl , Koyuncu Adem , Ghaemi Mehran , Kracht Lutz W. , Habedank Birgit , Heiss Wolf‐Dieter 
Published: August 2002

AbstractWe investigated plasticity of language networks exposed to slowly evolving brain damage. Single subject O‐15‐water language activation positron emission tomography studies were analyzed in 61 right‐handed patients with brain tumors of the left hemisphere, and 12 normal controls. In controls, activations were found in left Brodmann's Area (BA)44 and BA45, superior posterior temporal gyrus bilaterally, and right cerebellum. Patients additionally activated left BA46, BA47, anterior insula, and left cerebellum. Superior temporal activation was less frequent, and activations in areas other than posterior temporal gyrus were found bilaterally. Frontolateral activations within the nondominant hemisphere were only seen in patients (63%) with frontal or posterior temporal lesions. Laterality indices of frontolateral cortex showed reversed language dominance in 18% of patients. Laterality indices of the cerebellum were negatively correlated with language performance. Two compensatory mechanisms in patients with slowly evolving brain lesions are described: An intrahemispheric mechanism with recruitment of left frontolateral regions other than classic language areas; and an interhemispheric compensatory mechanism with frontolateral activation in the nondominant hemisphere. The latter one was only found in patients with frontal or posterior temporal lesions, thus supporting the hypothesis that right frontolateral activations are a disinhibition phenomenon.
Synthesis and in vitro antitumor activity of some tetraphenylantimony derivatives of exo‐7‐oxa‐bicyclo[2,2,1] heptane (ene)‐3‐arylamide‐2‐acid
Authors: Li Jin‐Shan , Ma Yong‐Qiang , Cui Jing‐Rong , Wang Rui‐Qing 
Published: August 2002

AbstractA series of novel tetraphenylantimony derivatives of exo‐7‐oxa‐bicyclo[2,2,1] heptane (ene)‐3‐arylamide‐2‐acid of the general formula Ph4SbO2CCHCHCH2CH2CH(O)HCONHAr (Ar = Ph,4‐ClC6H4, 4‐BrC6H4, 3‐BrC6H4, 4‐F‐3‐ClC6H3 and 4‐MeC6H4) have been synthesized and characterized by elemental analysis, IR, 1H NMR and mass spectra. The crystal structure of Ph4SbO2CCHCHCH2CH2CH(O)HCONHC6­H4CH3·CHCl3 was determined by X‐ray diffraction. Five human neoplastic cell lines (HL‐60, KB, Bel‐7402, BGC‐823 and HCT‐8) were used to screen these compounds. The results indicate that these compounds at 10 µM show certain in vitro antitumor activities. Copyright © 2001 John Wiley & Sons, Ltd.
Tensile and dynamic mechanical properties of improved ultrathin polymeric films
Authors: Bhushan Bharat , Ma Tiejun , Higashioji Takuji 
Published: August 2002

AbstractTensile and dynamic mechanical properties of improved ultrathin polymeric films for magnetic tapes are presented. These films include poly(ethylene terephthalate) or PET, poly(ethylene naphthalate) or PEN, and aromatic polyamide (ARAMID). PET film is currently the standard substrate used for magnetic tapes; thinner tensilized‐type PET, PEN, and ARAMID were recently used as alternate substrates with improved material properties. The thickness of the films ranges from 6.2 to 4.8 μm. Young's modulus of elasticity, F5 value, strain‐at‐yield, breaking strength, and strain‐at‐break were obtained at low strain rates by using a tensile machine. Storage (or elastic) modulus, E′, and the loss tangent, tan δ, which is a measurement of viscous energy dissipation, are measured by using a dynamic mechanical analyzer at temperature ranges of −50 to 150°C (for PET), and −50 to 210°C (for PEN and ARAMID), and at a frequency range of 0.016 to 29 Hz. Frequency–temperature superposition was used to predict the dynamic mechanical behavior of the films over a 28 decade frequency range. Results show that ARAMID and tensilized films tend to have higher strength and moduli than standard PET and PEN. The rates of decrease of storage modulus as a function of temperature are lower for PET films than those for PEN and ARAMID films. Storage modulus for PEN films are higher than that for PET films at high frequencies, but this relationship reverses at low frequencies. ARAMID has the highest modulus and strength among the films in this study. The relationship between polymeric structure and mechanical properties are also discussed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2225–2244, 2002
Structural effects of compatibilizer localization and effectivity in thermoplastic polyurethane–polyolefin blends
Authors: Stutz Herbert , Heckmann Walter , Pötschke Petra , Wallheinke Katrin 
Published: August 2002

AbstractA study was performed with blends of thermoplastic polyurethanes and polyolefins to determine the structural requirements for a compatibilizer to be located at the interface. It was demonstrated that during the addition of an incompatible polymeric additive (i.e., incompatible with both blend constituents) to a polyurethane–polyolefin blend, the additive migrated to the interface. This interfacial phenomenon was proven to be virtually independent of compatibilizer viscosity or surface activity. Only when the compatibilizer was quite comparable to one of the phases did small differences in polarity govern whether the compatibilizer remained at the interface or formed micelles. This effect was demonstrated with a series of styrene–(ethylene–butylene)–styrene block copolymer compatibilizers. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2901–2905, 2002; DOI 10.1002/app.10285
Characterization of hydrogels based on chitosan and copolymer of poly(dimethylsiloxane) and poly(vinyl alcohol)
Authors: Shin Mi‐Seon , Kim Sun I. , Kim In Young , Kim Nam Gyun , Song Chul Gyu , Kim Seon Jeong 
Published: August 2002

AbstractCopolymers composed of poly(vinyl alcohol) (PVA) and poly(dimethylsiloxane) (PDMS) were crosslinked with chitosan to prepare semi‐interpenetrating polymer network (IPN) hydrogels by an ultraviolet (UV) irradiation method for application as potential biomedical materials. PVA/PDMS copolymer and chitosan was cast to prepare hydrogel films, followed by a subsequent crosslinking with 2,2‐dimethoxy‐2‐phenylacetophenone as a nontoxic photoinitiator by UV irradiation. Various semi‐interpenetrating polymer networks (semi‐IPNs) were prepared from different weight ratios of chitosan and the copolymer of PVA/PDMS. Photocrosslinked hydrogels exhibited an equilibrium water content (EWC) in the range of 65–95%. Swelling behaviors of these hydrogels were studied by immersion of the gels in various buffer solutions. Particularly, the PCN13 as the highest chitosan weight ratio in semi‐IPN hydrogels showed the highest EWC in time‐dependent and pH‐dependent swelling. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2591–2596, 2002
Copolymerization behavior and kinetics of an epoxy copolymer with zero shrinkage
Authors: Zhou Zhiqiang , Jin Bangkun , He Pingsheng 
Published: August 2002

AbstractThe copolymerization behavior and the apparent cure kinetics of epoxy resin E51 containing the expanding monomer 3,9‐di(5‐norbornene‐2,2)‐1,5,7,11‐tetraoxaspiro [5,5] undecane (NSOC, norbornene spiro orthocarbonate), were investigated by using differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. Evidence for random copolymerization of the E51‐NSOC system was obtained by dynamic mechanical analysis and electron microscopy. The ring‐opening reaction of the epoxy resin was found to be first order with an activation energy of 62.0 kJ/mol and the reaction with the expanding monomer NSOC was second order with an activation energy of 121.3 kJ/mol. The comonomers were joined with an ether linkage. Longer copolymerization sequence lengths were obtained with higher NSOC contents in the copolymer. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1457–1464, 2002; DOI 10.1002/app.10485
Formulation and optimization of thermoplastic polyamide elastomer properties by mixture response surface methodology
Authors: Twu Yawo‐Kuo , Chen Chao‐Jen , Shieh Chwen‐Jen 
Published: August 2002

AbstractIn this study, the formulation and optimization of the properties of thermoplastic polyamide elastomers (TPAEs) were evaluated by a mixture response surface methodology. The TPAEs prepared from different chain extender blends of adipic acid, terephthalic acid (TPA), and C36 dimer acid were characterized by specific gravity measurement, water absorption measurement, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The results indicate that the specific gravity of the polymers increased and the water absorption of the polymers decreased as the content of TPA increased. The DSC data show two major endotherms corresponding to the melt of poly(tetramethylene ether) glycol (PTMEG) and nylon‐6 segments. The TGA data show that the thermal degradation temperatures of the polymers increased as the C36 dimer acid content increased. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 9–16, 2002
Effects of molecular weight of polyvinylpyrrolidone on precipitation kinetics during the formation of asymmetric polyacrylonitrile membrane
Authors: Kang Jong Seok , Lee Young Moo 
Published: August 2002

AbstractThe effects of the molecular weight of polyvinylpyrrolidone (PVP) on the precipitation kinetics during the formation of an asymmetric polyacrylonitrile membrane and the resulting membrane morphology were investigated. The precipitation kinetics of a polyacrylonitrile membrane was explored using the light‐transmission method and optical microscopic observation, with an emphasis on the effective diffusion coefficient of the nonsolvent as a measure of the solvent/nonsolvent exchange rate. The retarded precipitation behaviors were not observed in all dope solutions. Also, the phase‐ separation rate was steeply decreased with the amount of PVP. It was deduced that increase of the viscosity of the polymer solution upon the addition of PVP hindered the intrusion of the nonsolvent, resulting in a decrease of the phase‐separation rate. When the same amount of PVP with a different molecular weight was used, the precipitation rate decreased with increase of the molecular weight of PVP. Therefore, the nonsolvent tolerance, the interaction between PVP and H2O, as well as the viscosity are regarded as important factors influencing the precipitation rate. The effective diffusion coefficient of the nonsolvent is closely related to the nonsolvent tolerance of the polymer solution, resulting from a pseudoternary phase diagram. The use of high molecular weight PVP strongly depressed the formation of macrovoids inside of the membrane and allowed a dense skin layer to form. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 57–68, 2002
Synthesis and characterization of network liquid crystal elastomers and thermosets
Authors: Jia Yinggang , Zhang Baoyan , Zhou Enle , Feng Zhiliu , Zang Baoling 
Published: August 2002

AbstractA new series of network liquid crystal polymers were synthesized by graft copolymerization of the difunctional mesogenic monomer 4‐allyloxy‐benzoyloxy‐4′‐allyloxybiphenyl (M) upon polymethylhydrosiloxane (PMHS). Monomer M acted not only as a mesogenic unit but also as a crosslinker for the network polymers. The chemical structures of the polymers were confirmed by IR spectroscopy. DSC, TGA, and X‐ray scattering were used to measure their thermal properties and mesogenic properties. The glass transition temperature (Tg) of these network liquid crystal polymers was increased when the monomer was increased, and Td (temperature of 5% weight loss) at first went up and reached a maximum at P1, then went down. The slightly crosslinked polymers (P0, P1) show rubber‐like elasticity, so it was called liquid‐crystal elastomer. Network polymers will lose elasticity property with a highly crosslinked degree, and turn into thermosetting polymers (P4, P5). All polymers exhibited a smectic texture by X‐ray scattering. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1104–1109, 2002
Impact response of carbon‐epoxy laminates containing buffer‐strip layers
Authors: Kishore  , Khan Bijoysri , Viswanath B. 
Published: August 2002

AbstractThis work looks at the dynamic behavior of laminated carbon‐epoxy (C‐E) composites with inserted interleaf polytetrafluoroethylene (PTFE)‐coated material. Instrumented impact tests performed on the interleaved test samples showed significant differences in the energy absorption characteristics that could be correlated with the failure mode. It was inferred that with the introduction of small amounts of less adherent layers of material at specific locations, the load‐carrying ability decreased while the energy‐absorbing capability was found to improve considerably. These and other experimental observations are discussed in this article. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 752–761, 2002
Kinetic study of olefin polymerization with a supported metallocene catalyst. II. Ethylene/1‐hexene copolymerization in gas phase
Authors: Chakravarti S. , Ray W. Harmon 
Published: August 2002

AbstractA kinetic study of ethylene/1‐hexene copolymerization is conducted with a supported metallocene catalyst in a gas‐phase reactor. The investigation into the kinetics of ethylene/1‐hexene copolymerization includes the effects of operational parameters such as the reaction temperature, pressure, and comonomer concentration. The large variations in gas‐phase composition using only an initial charge of 1‐hexene are illustrated by experiment. To remedy this, the ability to control the comonomer composition of 1‐hexene online for the entire duration of the reaction is demonstrated. Online perturbation techniques are implemented to determine key kinetic parameters such as the activation energies for propagation and catalyst deactivation. From pressure perturbation results, a reaction rate order close to 1 is obtained for ethylene in the presence of 1‐hexene. Finally, all the parameters obtained from the study are compared to those determined from ethylene–propylene (E–P) copolymerization. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1096–1119, 2001
Phase behavior and morphological studies of polyimide/PVP/solvent/water systems by phase inversion
Authors: Kim Jong Hak , Min Byoung Ryul , Park Hyun Chae , Won Jongok , Kang Yong Soo 
Published: August 2002

AbstractThe solubility gaps for poly(vinyl pyrrolidone) (PVP) in four polyimide solutions (NMP, DMF, GBL, DMSO) were determined by cloud point measurement and correlated with χPI/Solvent and ΔδPVP/Solvent. Membranes prepared with NMP and DMF systems showed a tendency of suppressing fingerlike structure with addition of PVP. On the other hand, membranes prepared with GBL and DMSO systems showed an inclination toward inducing macrovoid formation. These effects of PVP on the membrane morphology were explained by means of miscibility gap, viscosity of the polymer solution, polymer–polymer phase separation, and overall porosity. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3481–3488, 2001
Carrier‐bound methotrexate. I. Water‐soluble polyaspartamide–methotrexate conjugates with ester links in the polymer–drug spacer
Authors: Meirim M. G. , Neuse E. W. , N'Da D. D. 
Published: August 2002

AbstractThe antifolate‐type anticancer drug methotrexate (MTX) has for many years, in numerous laboratories, been a “workhorse” drug for conjugation with natural and synthetic macromolecular carriers for the purpose of enhancing bioavailability and lowering toxic side effects. In the project here described the polymer–drug conjugation strategy is utilized for the preparation of water‐soluble polyaspartamide–methotrexate conjugates in which the drug is carrier‐anchored through short spacers containing ester groups as biofissionable links. To this end, polyaspartamide carriers 1, poly‐α,β‐D,L‐N‐(2‐hydroxyethyl)aspartamide, and 2, poly‐α,β‐D,L‐N‐[2‐(2‐hydroxyethoxy)ethyl]aspartamide, are treated with MTX in DMF solution in the presence of a carbodiimide coupling agent and 4‐(dimethylamino)pyridine catalyst. The molar MTX/OH feed ratios, 0.28 and lower, are chosen in these coupling reactions so as to provide conjugates featuring drug‐loading levels in the approximate range of 3–16 mol % MTX, roughly corresponding to 6–28% by mass. The water‐soluble product polymers are purified by aqueous dialysis, collected in the solid state by freeze‐drying, and structurally characterized by 1H–NMR spectroscopy. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1844–1849, 2001
Biosynthetic processes for linear polymers
Authors: Asrar Jawed , Hill James C. 
Published: August 2002

AbstractBiosynthetic processes for production of linear proteins, polysaccharides, and polyhydroxyalkanoates (PHAs) are discussed. Processes for converting the linear biopolymers into useful products are described. Techniques and additives for improving the processability of PHAs and potential applications of PHAs are reviewed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 457–483, 2002
Limnological changes in a sub‐tropical shallow hypertrophic lake during its restoration: two years of a whole‐lake experiment
Authors: Scasso F. , Mazzeo N. , Gorga J. , Kruk C. , Lacerot G. , Clemente J. , Fabián D. , Bonilla S. 
Published: August 2002

Abstract1. Lake Rodó is a turbid system, a condition attributed to algal biomass. The proximal source of the eutrophication was stormwater discharges from an ill‐defined urban area. This paper describes an attempt to restore the water quality of Lake Rodó, the first time this has been done in Uruguay. In spring 1996 it was drained, sediments were removed and stream inputs were diverted. Groundwater was used to re‐fill the lake. Due to its high nutrient concentration a re‐circulation system was designed, pumping water from associated pools covered with free‐floating plants.2. After the lake was refilled, the system was characterized by oxygen saturation or over‐saturation, neutral to basic pH, and high phosphorus, nitrogen and silicate concentrations. Ratios of total nitrogen (TN):total phosphorus (TP) and chlorophylla(Chla):TP indicated that phosphorus was the primary limiting nutrient during the period of groundwater supply. Once groundwater pumping had ceased, there was a decrease in TN:TP and Chla:TP ratios, suggesting N‐limiting conditions prevailed in some periods.3. Before restoration, the phytoplankton community was dominated year‐round byPlanktothrix agardhii; since restoration the community has been more diverse. This change has favoured grazing by mesozooplankton, and the onset of clear‐water phases in spring.4. Abundant populations of small omnivorous fish maintained a high predation pressure on zooplankton, restricting the abundance of large‐bodied herbivores, which, in turn, allowed an increase in phytoplanton biomass and a decrease in water transparency. Based on this observation, together with the phosphorus concentration and the low abundance of filamentous cyanobacteria compared with previous studies, we suggest that top‐down control has played a key role in increasing transparency in Lake Rodó.5. A nutrient reduction programme, by the mechanical harvest of floating plants, and a removal of small omnivorous fishes and stocking strictly with piscivores, could be key factors in the achievement of a stable clear‐water phase. However, if blooms ofMicrocystisor other similar genera occur in summer, additional measures (e.g. reduction of the hydraulic residence time) will be needed to improve water transparency.Copyright © 2001 John Wiley & Sons, Ltd.