bluuebunny/crossref_metadata_2025 huggingface dataset:
Decisions about amniocentesis by advanced maternal age patients following maternal serum screening may not always correlate clinically with screening results: Need for improvement in informed consent process
Authors: Marini Tina , Sullivan Jan , Naeem Rizwan
Published: August 2002

We evaluated the prenatal diagnosis utilization patterns of advanced maternal age (AMA) patients who underwent serum screening to assess how screening results correlated with their decisions regarding amniocentesis. A 6‐year review (1994–1999) of laboratory records identified 2,456 AMA patients who underwent multiple‐marker serum screening. The relationship between screening results and patients' decisions on whether or not to undergo amniocentesis was assessed. Among the 841 AMA patients with positive screens, more than half (52%) declined amniocentesis. Of the 1,615 patients with negative serum screening results, 208 (13%) opted for amniocentesis. We concluded that decisions by AMA patients regarding amniocentesis may not always correlate clinically with maternal serum screening results. Possible explanations, including how the state of informed consent may or may not contribute to these decisions, are discussed. It is suggested that understanding the reasons for these decisions may identify opportunities for improving service delivery to all pregnant patients considering prenatal testing. Use of a questionnaire is proposed as one mechanism for gaining a clearer understanding of the possible factors contributing to AMA patient decisions. © 2002 Wiley‐Liss, Inc.
Evidence for linkage disequilibrium between the alpha 7‐nicotinic receptor gene (CHRNA7) locus and schizophrenia in Azorean families*
Authors: Xu Junzhe , Pato Michele T. , Torre Camille Dalla , Medeiros Helena , Carvalho Celia , Basile Vincenzo S. , Bauer Amy , Dourado Ana , Valente Jose , Soares Maria Joao , Macedo Antonio A. , Coelho Isabel , Ferreira Carlos Paz , Azevedo M. Helena , Macciardi Fabio , Kennedy James L. , Pato Carlos N.
Published: August 2002

Recent studies have suggested that the alpha 7‐nicotinic receptor gene (CHRNA7) may play a role in the pathogenesis of schizophrenia. The alpha 7‐nicotinic receptor gene (CHRNA7) is involved in P50 auditory sensory gating deficits, and the genomic locus for this gene lies in the chromosome 15q13–14 regions. The human gene is partially duplicated (exons 5–10) with four novel upstream exons. The marker D15S1360 has been shown to be significantly linked with the phenotype of abnormal P50 suppression in schizophrenia families. The marker L76630 is 3 kb in the 3′ direction from the last exon of the CHRNA7 gene and is located in the duplicated region. The function of the two L76630 copies is unknown. We genotyped three polymorphic markers D15S1360, D15S165, and L76630 that are localized in a genomic fragment containing the CHRNA7 in 31 Azorean schizophrenia families/trios (including 41 schizophrenia individuals and 97 unaffected families members). An overall analysis utilizing the family‐based association test revealed significant linkage disequilibrium between L76630 and schizophrenia (P = 0.0004). Using the extended transmission disequilibrium test and limiting the analysis to one triad per family, transmission disequilibrium of D15S1360 was near significance (P = 0.078). The 15q13 region overlaps with the location of two well‐known genomically imprinted disorders: Angelman syndrome and Prader‐Willi syndrome. Therefore, we investigated maternal and paternal meioses. We found significant transmission disequilibrium for D15S1360 through paternal transmission (P = 0.0006) in our schizophrenia families. The L76630 marker showed a significant disequilibrium in maternal transmissions (P = 0.028). No parent‐of‐origin effect was found in D15S165. Overall, our results suggest that the CHRNA7 may play a role in schizophrenia in these families. A parent of origin effect may be present and requires further study. Published 2001 Wiley‐Liss, Inc.
A balanced reciprocal translocation t(5;7)(q14;q32) associated with autistic disorder: Molecular analysis of the chromosome 7 breakpoint
Authors: Tentler Dmitry , Brandberg Göran , Betancur Catalina , Gillberg Christopher , Annerén Göran , Orsmark Christina , Green Eric D , Carlsson Birgit , Dahl Niklas
Published: August 2002

Autism is a neuropsychiatric disorder characterized by impairments in social interaction, restricted and stereotypic pattern of interest with onset by 3 years of age. The results of genetic linkage studied for autistic disorder (AD) have suggested a susceptibility locus for the disease on the long arm of chromosome 7. We report a girl with AD and a balanced reciprocal translocation t(5;7)(q14;q32). The mother carries the translocation but do not express the disease. Fluorescent in situ hybridization (FISH) analysis with chromosome 7–specific YAC clones showed that the breakpoint coincides with the candidate region for AD. We identified a PAC clone that spans the translocation breakpoint and the breakpoint was mapped to a 2 kb region. Mutation screening of the genes SSBP and T2R3 located just centromeric to the breakpoint was performed in a set of 29 unrelated autistic sibling pairs who shared at least one chromosome 7 haplotype. We found no sequence variations, which predict amino acid alterations. Two single nucleotide polymorphisms were identified in the T2R3 gene, and associations between allele variants and AD in our population were not found. The methylation pattern of different chromosome 7 regions in the patient's genomic DNA appears normal. Here we report the clinical presentation of the patient with AD and the characterization of the genomic organization across the breakpoint at 7q32. The precise localization of the breakpoint on 7q32 may be relevant for further linkage studies and molecular analysis of AD in this region. © 2001 Wiley‐Liss, Inc.
Abundance, diversity, and patterns of distribution of primates on the Tapiche River in Amazonian Peru
Authors: Bennett Cynthia L. , Leonard Suzi , Carter Scott
Published: August 2002

This work presents data on the relative diversity, abundance, and distribution patterns of primates in a 20 km2area of the Tapiche River in the Peruvian Amazon. Population data were collected while the study area was both inundated and dry (March to September 1997) using conventional line‐transect census techniques. Survey results reflected the presence of 11 primate species, but population parameters on only eight of the species will be presented, including saddleback tamarins (Saguinus fuscicollis), Bolivian squirrel monkeys (Saimiri boliviensis), brown capuchins (Cebus apella), white‐fronted capuchins (Cebus albifrons), monk sakis (Pithecia monachus), red titi monkeys (Callicebus cupreus), red uakaris (Cacajao calvus), and red howler monkeys (Alouatta seniculus). Woolly monkeys (Lagothrix lagotricha), night monkeys (Aotus nancymaae), and pygmy marmosets (Callithrix pygmaea) were also seen in the area. The data for the smaller‐bodied primates is similar to that reported almost 18 years earlier, but the data for the larger‐bodied primates reflect a loss in the number of animals present in the area. Pressure from hunters and the timber industry may account for declining numbers of large‐bodied primates, while it appears that natural features peculiar to the conservation area contribute to the patchy pattern of distribution. Am. J. Primatol. 54:119–126, 2001. © 2001 Wiley‐Liss, Inc.
Dental relatedness corresponding to mortuary patterning at Huaca Loro, Peru
Authors: Corruccini Robert S. , Shimada Izumi
Published: August 2002

Within and between tombs at the 1,000‐year‐old site of Huaca Loro on north coastal Peru, interment characteristics vary to an intriguing degree. Following and elaborating upon prior intracemetery studies, biological relatedness among associated burial groupings was assessed using 23 dental characters (assuming familial allele segregation) for 29 individuals. Biological patterning was based on multivariate distance between individuals using all traits, rather than the previously widespread reliance upon univariate comparison of each trait separately within samples. This multivariate approach did seem more informative. Statistically significant variation of biological similarities and dissimilarities corresponded to spatial groupings and also to various specific archaeological indications of the cohesiveness, or lack thereof, of interment pattern. The partition of biological distances among tombs at Huaca Loro supports the archaeological evidence that the tombs represent a planned elite cemetery. Am J Phys Anthropol 117:113–121, 2002. © 2002 Wiley‐Liss, Inc.
Scale issues in the study of primate foraging: Red colobus of Kibale National Park
Authors: Chapman Colin A. , Chapman Lauren J. , Gillespie Thomas R.
Published: August 2002

Diet data have been used to address a number of theoretical issues. We often calculate the proportion of time spent eating different foods (e.g., fruits, leaves) to place species into dietary categories and contrast morphological or behavioral traits among categories. Yet we have little understanding of how flexible species can be in terms of the plant parts and species consumed. To address this issue, we analyzed data on the diets of red colobus monkeys (Procolobus badius) from Kibale National Park, Uganda, to evaluate temporal and spatial variability in the plant parts and species eaten. After considering observer differences and sampling issues, we evaluated how different a group's diet could be if samples were taken in different years. We found that the diet of the same groups showed significant, consistent changes over a 4‐year period. For example, the time spent feeding on leaves increased from 56% in 1994 to 76% in 1998. The plant parts and species eaten by eight groups inhabiting different types of forest (e.g., pristine, logged, riverine) varied among groups. The largest interdemic difference was seen in the use of young leaves (38%). Dietary differences were also found between groups with overlapping home ranges (41–49% overlap). Different subspecies of Procolobus badius also varied in diet; however, this variation was often not of the magnitude documented within Kibale for the same population. The fact that diet can vary considerably over small spatial and short temporal scales within the same species raises the intriguing question as to what level of interspecific difference is biologically significant for addressing particular questions. We conclude that behavioral flexibility blurs our traditional stereotypic assessment of primates; a study of one group that occupies a specific habitat at one point in time may not adequately represent the species. Am J Phys Anthropol 117:349–363, 2002. © 2002 Wiley‐Liss, Inc.
Magnetoencephalographic fields from patients with spontaneous and induced migraine aura
Authors: Bowyer Susan M. , Aurora Sheena K. , Moran John E. , Tepley Norman , Welch K. M. A.
Published: August 2002

We investigate and characterize the magnetoencephalographic waveforms from patients during spontaneous and visually induced migraine aura. Direct current neuromagnetic fields were measured during spontaneous onset of migraine auras in 4 migraine patients, and compared with recordings from 8 migraine‐with‐aura patients and 6 normal controls during visual stimulation of the occipital cortex. Complex direct current magnetoencephalographic shifts, similar in waveform, were observed in spontaneous and visually induced migraine patients, but not in controls. Two‐dimensional inverse imaging showed multiple cortical areas activated in spontaneous and visually induced migraine aura patients. In normal subjects, activation was only observed in the primary visual cortex. Results support a spreading, depression‐like neuroelectric event occurring during migraine aura that can arise spontaneously or be visually triggered in widespread regions of hyperexcitable occipital cortex.
Arsenic compounds in marine sponge (Haliclona permolis, Halichondria japonica, Halichondria okadai and Haliclona sp. white) from Seto Inland Sea, Japan
Authors: Yamaoka Yukiho , Carmona Marvelisa L. , Oclarit Jose M. , Jin Kazuo , Shibata Yasuyuki
Published: August 2002

Marine sponges were collected at Hiro or Hatami, Hiroshima Prefecture, Aki Nada in the Seto Inland Sea, Japan. Arsenic compounds were extracted with methanol/water (1:1, v/v) from freeze‐dried samples of the marine sponges Haliclona permolis, Halichondria japonica, Halichondria okadai and Haliclona sp. white. The extracts were analyzed by high‐performance liquid chromatography, with an inductively coupled plasma mass spectrometer serving as an arsenic‐specific detector. Arsenobetaine 5 and the two arsenosugars as 6 and 7 were identified in all samples targeted, and these three compounds accounted for 74 to 96% of the water‐soluble arsenic in all four species of sponge. Arsenosugar was the major arsenic species in all four species of sponge. The most abundant arsenic compound in all four species of sponge was arsenosugar 7, and arsenosugar 6 was only a minor component. The arsenobetaine and arsenosugar concentrations were considerably higher in the three sponges from demospongiae (H. permolis, H. japonica and H. okadai) compared with the single species from calcispongiae (Haliclona sp. white). Copyright © 2001 John Wiley & Sons, Ltd.
Biomethylation and bioaccumulation of arsenic(V) by marine alga Fucus gardneri
Authors: Granchinho Sophia C. R. , Polishchuk Elena , Cullen William R. , Reimer Kenneth J.
Published: August 2002

The brown alga, Fucus gardneri, was collected from Vancouver Island, B.C., Canada. Fucus samples were acclimated in seawater and then exposed to arsenic(V) in artificial seawater, all under axenic conditions. The arsenic species in the Fucus samples were extracted into 1:1 methanol/H2O and identified by using ion‐pairing high‐performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC–ICP‐MS). Anion‐exchange HPLC–ICP‐MS was used to identify the arsenic species in the growth medium. It was found that ∼73% of the original arsenosugars in the F. gardneri samples were lost during the acclimation period. Arsenite [As(III)] and dimethylarsenate [DMA] concentration increased in the Fucus samples after exposure to arsenate [As(V)]. A small increase in the concentration of an arsenosugar was seen during this period, accompanied by a further decrease in the concentration of two other arsenosugars. The experiments provided very little evidence for the hypothesis that arsenosugars are produced by the macroalgae. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis of organofunctional silanes with sterically hindered substituents at silicon atoms
Authors: Guliński Jacek , Maciejewski Hieronim , Dąbek Izabela , Zaborski Marian
Published: August 2002

Organofunctional silanes with more sterically hindered substituents at the silicon atom than the typical methoxy (ethoxy) group have lately been frequently used as silane coupling agents, in polymer coupling systems, sol‐gel processes and also as interpenetrating polymer network substrates. New and very efficient synthetic ways leading to organofunctional silanes of the above type with methacryl, amine, chloro and isocyanato functional groups are proposed here. Catalytic transesterification and/or alcoholysis of chloropropyltrialkoxysilanes followed by­nucleophilic substitution has been employed. Copyright © 2001 John Wiley & Sons, Ltd.
Silicon–oxygen‐bonded oligomers having thermoelectric switching properties
Authors: Purkayastha Arup , Baruah Jubaraj B.
Published: August 2002

The electrical properties of siloxane oligomers prepared from the reaction of 1,4‐naphthalenediol or 1,4‐naphthoquinone with diphenylsilane using different palladium catalysts, such as PdCl2, Pd(TMEDA)Cl2, Pd(TEEDA)Cl2 (where TMEDA = N,N′‐tetramethylethylenediamine, TEEDA = N,N′‐tetraethylethylenediamine), are dependent on the catalyst. Thermoelectric switching properties can be obtained from the siloxane prepared from the coupling reaction of diphenylsilane with 1,4‐naphthoquinone or 1,4‐naphthalenediol using Pd(TMEDA)Cl2 as catalyst. Copyright © 2001 John Wiley & Sons, Ltd.
Study on the thermal stability of heterogeneous nucleation effect of polypropylene nucleated by different nucleating agents
Authors: Mai Kancheng , Wang Kefeng , Han Zhiwu , Zeng Hanmin
Published: August 2002

The thermal stability of the heterogeneous nucleation effect of polypropylene (PP) nucleated with an organic phosphate (A) and two kinds of sorbitol derivatives (B and D) was investigated by DSC multiscanning. For pure PP, the peak temperature of crystallization (T) was little changed with an increasing number of DSC scans, indicating that nucleation of PP is thermally stable. For the PP nucleated with an organic phosphate (PPA), the temperatures at the onset of crystallization (T) and at the completion of crystallization (T); the peak temperature of crystallization (T) and melting (T); and the heat of crystallization (ΔHc) and fusion (ΔHm) of PP are higher than those of pure PP and were little influenced with an increasing number of DSC scans. For PP nucleated with the sorbitol derivatives (PPB and PPD), the T, T, T, and T decreased with an increasing the number of scans. These results indicated that the thermal stability of heterogeneous nucleation effect of the nucleating agent A is higher than that of nucleating agents B and D. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1643–1650, 2002
Polystyrene and polyether polyurethane elastomer blends compatibilized by SMA: Morphology and mechanical properties
Authors: Cassu Silvana Navarro , Maria Isabel Felisberti
Published: August 2002

Blends of polystyrene (PS) and the polyether polyurethane elastomer (PU‐et) were prepared by melt mixing using poly(styrene‐co‐maleic anhydride) (SMA) containing 7 wt % of maleic anhydride as a compatibilizer. The polyurethane in the blends was crosslinked using dicumyl peroxide or sulfur. The content of maleic anhydride was varied in the blends through the addition of different SMA amounts. The morphology of the blends was analyzed by SEM and a drastic reduction of both the domain size and its distribution was observed with increase of the anhydride content in the blends. The morphology of the PU‐et blends also showed dependence on the crosslinker agent used for the elastomer, and larger domains were obtained for the elastomer phase crosslinked with dicumyl peroxide. The mechanical properties of the blends were evaluated by flexural and impact strength tests. The blend containing 0.5 wt % of maleic anhydride and 20 wt % of PU‐et crosslinked with sulfur showed the highest strength impact, which was three times superior to the PS strength impact, and the blends containing 20 wt % of PU‐et crosslinked with dicumyl peroxide showed the highest deflection at break independent of the anhydride content. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 830–837, 2002
Photocurable positive photoresist‐comprising copolymers having pendant alkoxy ethyl moieties
Authors: Liu Jui‐Hsiang , Shih Jen‐Chieh
Published: August 2002

A series of copolymers based on methacrylic acid (MAA), methyl methacrylate (MMA), n‐butyl methacrylate (BM), and bornyl methacrylate (BMA) with various feed molar ratios were synthesized. To introduce the protecting alkoxy ethyl moieties onto copolymers, the pendant carboxyl groups were further reacted with alkyl vinyl ether. The pendant alkoxy ethyl groups on copolymers could be deprotected by acid catalyst. Characterization of positive‐tone photoresist‐comprising copolymers having pendant alkoxy ethyl groups was carried out. Effects of alicyclic bornyl groups on the sensitivity and thermal properties of copolymers were investigated. It was found that the existence of bornyl groups in polymer might interfere with the hydrogen bonding produced by pendant carboxyl groups, leading to the decrease of thermal resistance. Acid‐catalyzed dehydration crosslinking of pendant carboxyl groups of copolymers was also investigated. The exposure characteristic curves and the lithographic evaluation of the positive‐tone photoresist were all investigated. Effects of alicyclic bornyl groups on the plasma etching resist of copolymers were also evaluated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 889–897, 2002
Effects of the cure cycle and thermoplastic content on the final properties of dicyanate ester/polysulfone Semi‐IPNS
Authors: Harismendy I. , Del Rio M. , Valea A. , Gavalda Jna. , Mondragon I.
Published: August 2002

A bisphenol A dicyanate resin, BADCy, was toughened by incorporating polysulfone, PSU, at various compositions. The catalyst system used was a mixture of copper acetylacetonate and nonylphenol. Phase separation and rheokinetics were studied through curing. The blends seemed to have a LCST behavior, and the presence of PSU did not affect the polycyclotrimerization kinetics. The phase structure, thermal, and mechanical properties of the final network were investigated as a function of the PSU content and cure temperature. The toughness of the BADCy/PSU blends was closely related to their final morphology, increasing with the amount of phase inversion. The mechanical properties were not affected by the addition of the thermoplastic. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1799–1809, 2002
Influences of contents and molecular weights of LDPE on DOP plasticization of PVC
Authors: Shieh Yeong‐Tarng , Liu Chih‐Ming
Published: August 2002

Influences of contents and molecular weights of low‐density polyethylene (LDPE) on dioctyl phthalate (DOP) plasticization in the poly(vinyl chloride) (PVC) plastisol (PVC/DOP/AO = 100/30/6.5) were investigated using DMA and DSC. The plasticization effects of DOP on the PVC plastisol were found to decrease with increasing LDPE content. A negligible plasticization effect of DOP on the PVC plastisol was found when the LDPE content was equal to or higher than 75 parts per 100 parts by weight of LDPE and PVC together. Based on thermal fractionation experiments, a favorable interaction between LDPE and DOP was developed during melt blending of LDPE and the PVC plastisol. The present interaction enabled the incorporation of DOP into LDPE and decreased the plasticization effects of DOP on the PVC plastisol. A further decrease in the plasticization effects of DOP on the PVC plastisol by the presence of LDPE was found with increasing LDPE molecular weights. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2548–2555, 2002
Improvement of properties of silica‐filled natural rubber compounds using polychloroprene
Authors: Choi Sung‐Seen
Published: August 2002

Because silica has strong filler–filler interactions, a silica‐filled rubber compound is characterized by a poor dispersion of the filler. Properties of silica‐filled natural rubber (NR) compounds were improved using polychloroprene (chloroprene rubber [CR]). The bound rubber content of the compound increases and the filler dispersion is also improved by adding CR to the compound. Physical properties such as modulus, tensile strength, abrasion, and crack resistance are improved by adding CR. Elongation at break of the vulcanizates containing CR is longer than that of the vulcanizate without CR, although crosslink density of the former is higher than that of the latter. The improved physical properties are attributed to the good dispersion of silica by adding CR. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2609–2616, 2002
Thermal stabilization of poly(3‐hydroxybutyrate) by poly(glycidyl methacrylate)
Authors: Lee Seung No , Lee Moon Yeon , Park Won Ho
Published: August 2002

Poly(3‐hydroxybutyrate) (PHB)/poly(glycidyl methacrylate) (PGMA) blends with the PGMA content up to 30 wt % were prepared by a solution‐precipitation procedure. The thermal decomposition of PHB/PGMA blends was studied by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and differential thermal analysis (DTA). The thermograms of PHB/PGMA blends contained a two‐step degradation process, while that of pure PHB sample exhibited only one‐step degradation process. This degradation behavior of PHB/PGMA blends, which have a higher thermal stability as measured by maximum decomposition temperature or residual weight after isothermal degradation for 1 h, is probably due to crosslinking reactions of the epoxide groups in the PGMA component with the carboxyl chain ends of PHB fragments during the degradation process, and the occurrence of such reactions can be assigned to the exothermic peaks in their DTA thermograms. An isothermal study of these blends at 200–250°C for 1 h indicated that the residual weight was directly correlated with the amount of epoxide groups in the PHB/PGMA blends. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2945–2952, 2002; DOI 10.1002/app.10318
Effects of processing conditions on the curing of a vinyl ester resin
Authors: Abadie M. J. M. , Mekhissi K. , Burchill P. J.
Published: August 2002

The effects of temperature, initiator, and accelerator levels on the curing of an epoxy bisphenol‐A vinyl ester resin Derakane® 411‐45 (formulated with styrene) were investigated by gel‐time and exotherm‐peak measurements on bulk samples. It was observed that the gel time was reduced as the initiator or accelerator ratio increased. Except at higher contents of the accelerator, a small kinetic plateau was seen in the gel curve and a shift of the maximum exotherm toward high temperatures in the DSC curves. This was explained by the dual role played by the accelerator species. A regression analysis of all gel‐time data showed a dependence of 3/2 order in the accelerator and first order in the initiator concentrations. Thus, for this polymerization initiation system, the gel time can be predicted for any initiator and cobalt levels and at any temperature within the ranges studied. The effect of the initiator on the unreacted styrene and vinyl ester was also examined. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1146–1154, 2002; DOI 10.1002/app.10403
Synthesis of block copolyetherether ketones and investigations of their properties
Authors: Ozden S. , Charayev A. M. , Shaov A. H.
Published: August 2002

Using oligoketones with different degrees of condensation (n = 1, 10, 20), dichlorides of isophthalic and terephthalic acids and 2,2‐bis[4‐hydroxyphenyl]‐propane block‐copolyetherether ketones (BCPEEKs) were synthesized by means of acceptor–catalytic polycondensation. Their properties were also investigated. It was shown that BCPEEK possesses good solubility, high molecular weight, and is characterized by high thermal and mechanical properties. The correlation between some properties of the polyethers and the degree of condensation of oligoketones was also investigated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 485–490, 2002
Cellulose membranes grafted with vinyl monomers in homogeneous system
Authors: Ibrahim Maha M. , Flefel Eman M. , El‐Zawawy Waleed K.
Published: August 2002

The homogeneous grafting of a hydrophilic monomer onto cellulose derivatives was carried out in an aqueous system at 30, 50, 70, and 90°C during reaction periods of 30–180 min. The graft polymer was isolated by ethanol from the reaction mixture, dried, and weighed. The grafted polymer was characterized by the IR method, as well as the microscopic sample morphology detected by scanning electron microscopy. The water absorption capacities and grafting values of the grafted cellulose derivatives were also determined. The maximum grafting yield was obtained at 30°C. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2629–2638, 2002
Characterization of novel biodegradable copolyesters prepared from glycolyzed products of poly(ethylene terephthalate)
Authors: Maeda Yasukatsu , Mori Hajime , Maeda Takuya , Itoh Osamu , Yamaguchi Kazumi , Kubota Shizuo , Nakayama Atsuyoshi , Kawasaki Norioki , Yamamoto Noboru , Aiba Seiich
Published: August 2002

Poly(ethylene terephthalate), PET reacted with various glycols in the presence of titanium tetraisopropoxide as a catalyst. The glycolyzed PET was fractionated into two parts—soluble and insoluble in CHCl3—characterized and used as a raw material to synthesize copolyesters. The soluble part in the CHCl3 part was a mixture of monomers and oligomers, and no melting points were observed. On the other hand, in the insoluble part a melting point was determined. The glycolyzed PET and copoly(succinic anhydride/ethylene oxide), PES were condensed to produce copolymers. The synthesized copolyesters were amorphous and hydrolyzed enzymatically due to a decrease in the crystallinity. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1838–1847, 2002; DOI 10.1002/app.10462
The effect of mercapto‐modified EVA on rheological and dynamic mechanical properties of NBR/EVA blends
Authors: Jansen Paulo , Soares Bluma G.
Published: August 2002

The effect of mercapto‐modified ethylene vinyl acetate copolymer (EVALSH) on the rheological and dynamic mechanical properties of acrylonitrile butadiene rubber (NBR) and ethylene vinyl acetate copolymer (EVA) blends was evaluated at different blend compositions. The addition of 5 phr of EVALSH in the blends resulted in an increase of the melt viscosity and a substantial decrease of the extrudate swell ratio. These results can be attributed to the interactions occurring between the double bond of the NBR phase and the mercapto groups along the EVALSH backbone. The power–law index also presents a slight increase in the presence of EVALSH, indicating a decrease in the pseudoplastic nature of the compatibilized blends. The reactive compatibilization of NBR/EVA blends with EVALSH was also confirmed by the decrease of damping values and an increase of glass transition temperature, in dynamic mechanical analysis. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2335–2344, 2002
Morphological studies in thermally initiated emulsion (co)polymerization without conventional initiators
Authors: Du Yong‐Zhong , Ma Guang‐Hui , Ni Hen‐Mei , Nagai Masatoshi , Omi Shinzo
Published: August 2002

Poly(methyl methacrylate‐co‐styrene) composite latices were prepared by thermally initiated seed emulsion (co)polymerization of styrene (ST), methyl methacrylate (MMA), or ST and MMA employing a PST or PMMA seed in the absence of conventional initiators. The changes of particle morphology, observed by transmission electron microscopy (TEM), were investigated by varying seed particle component, the weight ratio of monomer to seed polymer, monomer composition, and employing preswelling of the seed particles. The size distribution of polymer particles obtained from thermally initiated emulsion (co)polymerization was improved by employing the seed process. Hemisphere‐like, sandwich‐like, core‐shell, and inverted core‐shell particle morphologies were observed depending upon the polymerization conditions. The preswelling of seed particles did not affect the morphology of final particles. The particle morphologies, obtained from the thermal process, were compared with those obtained from conventional seed emulsion polymerization. The incorporation of an initiator fragment SO to polymer chain ends seemed to allow the PST chains to gain some hydrophilicity. From the observation of particle morphology, the hydrophilicity of involved polymers were in the following order: PMMA with ionic (SO) chain ends > PMMA with no ionic ends > PST with ionic ends > 60% MMA P(MMA‐co‐ST) with no polar ends > 40% MMA P(MMA‐co‐ST) with no polar ends > PST with no polar ends. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1737–1748, 2002; DOI 10.1002/app.10581
Reentrant phase transition of poly(N‐isopropylacrylamide) gels in polymer solutions: Thermodynamic analysis
Authors: Gündogan Nermin , Okay Oguz
Published: August 2002

The swelling behavior of poly(N‐isopropylacrylamide) (PNIPA) gels in polymer solutions, particularly in aqueous solutions of poly(ethylene glycol)s, was investigated using the theory of equilibrium swelling. The volume of the PNIPA gel and the partition parameter of the macromolecules between the gel and the solution phases were calculated for various extents of the energetic interactions between the components. The simulation results were compared with the experimental data reported in the literature. It was shown that the PNIPA gel has a tendency to a reentrant phase transition in an aqueous solution of low molecular weight linear polymers. In such a transition, the gel first collapses, then reswells, if the linear polymer concentration is continuously varied. The necessary condition for the reentrant behavior of PNIPA gels was predicted in terms of the interaction parameters among the PNIPA network, the linear polymer, and water. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 801– 813, 2002
Role and relevance of polarity and hindrance of vinyl monomers in graft copolymerization onto potato starch
Authors: Fu Zheng Sheng , Liang Wei Dong , Yang Ai Mei , Wang Zhi Guo
Published: August 2002

The graft copolymerization of the vinyl monomers that were prepared by reactions of methyl acrylate and 4‐aminoazobenzene derivatives, such as 4‐aminoazobenzene, 4‐amino‐4′‐methyl azobenzene, 4‐amino‐4′‐nitro azobenzene, and 4‐amino‐3′,5′‐dinitro azobenzene, onto potato starch were carried out by the initiation of potassium persulfate. The evidence of grafted copolymers was investigated by using FTIR spectroscopy and acid hydrolysis technique. The relationship between grafting efficiency and monomer structure as well as polarity was studied. The experimental results showed that the graft copolymerization is independent of the polarity of the vinyl monomers and that the structures of monomers exhibit a marked influence on the graft copolymerization, namely, the larger the substitute is, the lower the grafting efficiency will be. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 896–899, 2002
Correlation between migration behaviors of antiozonants and temperature
Authors: Choi Sung‐Seen
Published: August 2002

Migration behaviors of antiozonants depending on temperature were studied using a carbon black‐filled NR vulcanizate containing N‐phenyl‐N′‐isopropyl‐p‐phenylenediamine (IPPD) and N‐phenyl‐N′‐(1,3‐dimethylbutyl)‐p‐phenylenediamine (HPPD) as antiozonants. The experimental temperatures were 100, 90, 80, and 70°C. Migration rates of them increased steeply by increasing the temperature. The correlation between the migration rates and the temperature was investigated using the half (t1/2)‐ and quarter (t1/4)‐lifetimes of the migrants remaining in the vulcanizate after the migration. The plot of log t versus 1/T was well fitted by the linear equation: The correlation coefficients were higher than 0.995. It was found that the migration behavior and temperature had a correlation of log t = b/T + c, where t and T are the migration time and temperature, b is Ea/R, and c is the constant. The activation energies for the migration were 36.48 and 37.93 kJ/mol for IPPD and HPPD, respectively. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1566–1570, 2001
Photoimaging technique on printing Al plate via self‐assembly multilayer films based on diazoresin
Authors: Chen Jinyu , Luo Hao , Yang Boxuan , Cao Weixiao
Published: August 2002

A photoimaging technique on a printing aluminum plate (anodized oxidation Al plate) via self‐assembly multilayer thin film from nitro‐containing diazoresin (NDR) as cationic polyelectrolyte and various anionic polyelectrolytes has been developed. It was confirmed that, under UV‐irradiation, the linkage nature of the films changes from ionic to covalent and the solubility of the films converts dramatically, that is, the exposed area of the film becomes insoluble in H2O–DMF–LiCl (2 : 4 : 1 wt %) ternary solvent, but mainly the unexposed area will be dissolved. After developing in ternary solvent, an image that accepts ink easily appears on the printing Al plate. To resolve the ink‐stain problem, originating from a trace remainder of the NDR on the unexposed area of the Al plate, a surface modification technique by polyphosphoric acid, which reacts with NDR to form a hydrophilic surface, was developed. The thickness, homogeneity, and surface morphology of the multilayer film (on mica) determined by atomic force microscopy and UV‐vis spectra were also reported. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1983–1987, 2001
Nitroxide‐mediated homopolymerization and copolymerization of 2‐vinylpyridine with styrene
Authors: Lokaj J. , Holler P.
Published: August 2002

Homopolymerization and copolymerization of 2‐vinylpyridine (2VP) with styrene (S) at 125°C in the presence of 2,2,6,6‐tetramethyl piperidin‐1‐yloxyl (TEMPO) radicals have been studied. The homopolymerization was carried out with 2,2′‐azobis(isobutyronitrile) (AIBN) as a thermal initiator or without AIBN in the initial reaction mixture. In the copolymerization initiated with AIBN, the molar fraction of 2VP in the feed, F2VP, varied in the range of 0.1–0.9; F2VP = 0.65 was found to be the azeotropic composition. The linear semilogarithmic time–conversion plots demonstrated a pseudoliving nature of the polymerizations under study. The molecular weight–conversion dependences indicated the participation of side reactions, diminishing the number of TEMPO‐terminated polymer chains. The synthesized homopolymers and copolymers were characterized using size‐exclusion chromatography (SEC), nitrogen analysis, and NMR spectroscopy. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2024–2030, 2001
Toughness enhancement of poly(ethylene terephthalate) with functionalized ultrahigh molecular weight polyethylene
Authors: Mascia L. , Ophir A.
Published: August 2002

Ultrahigh molecular weight polyethylene (UHMWPE) is available commercially in the form of powder, consisting of fine primary particles, 1–5 μm in diameter, agglomerated into secondary “free‐flowing” particles with overall dimensions in the region of 50 to 150 μm. These are normally sufficiently coherent and retain their conglomerated particulate structure when blended with other polymers because of the extremely high viscosity of UHMWPE. In this study the surface of the agglomerated primary particles was acid functionalized by reactions with aqueous solutions of acrylic acid, after being irradiated with γ‐radiation at 15–45 kGy. The acid groups were used to introduce a glycidoxyl functionality through reactions with a difunctional cycloaliphatic epoxy resin and also to a “partial” metal carboxylate functionality through reactions with zinc acetyl acetonate. When blended with polyethylene terephthalate (PET) in either a small‐batch mixer or in a twin‐screw extruder all the treated powders, except those functionalized with acrylic acid, were broken down to their primary size and were uniformly dispersed and strongly bonded to the surrounding matrix. The blends containing the deglomerated particles were found to have much greater ductility and toughness than those produced from both untreated and acid functionalized powder. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2972–2986, 2001
Study of carbon black distribution in BR/NBR blends based on damping properties: Influences of carbon black particle size, filler, and rubber polarity
Authors: Sirisinha Chakrit , Prayoonchatphan Nootjaree
Published: August 2002

Effects of filler and rubber polarity on the distribution of filler in butadiene/nitrile rubber (BR/NBR) blends were investigated, using the dynamic mechanical thermal analysis technique. As 30‐phr filler is added, the reduction in heights of damping peaks (tan δmax), attributed to the dilution effect, was observed. It was also found that the BR phase in the blends, compared to the NBR phase, is more preferential for small‐ and large‐particle size carbon blacks to reside, probably because of the lower viscosity and lower polarity of the BR phase. The addition of silica instead of carbon black leads to an increase in filler migration to the NBR in the 20/80 BR/NBR blend, which is attributed to the strong silica–NBR interaction. In addition, an increase in NBR polarity promotes carbon black migration to the BR phase. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3198–3203, 2001
Preparation and characterization of some new unsaturated polyesters based on 3,6‐bis(methoxymethyl)durene
Authors: Tawfik S. Y.
Published: August 2002

A series of unsaturated polyester resins based on 3,6‐bis(methoxymethyl)durene with different diacids or anhydrides, namely, phthalic anhydride, maleic anhydride, and succinic acid, and different glycols, namely, 1,2‐propylene glycol, triethylene glycol, 1,4‐cyclohexane diol, and 3,6‐bis(benzyloxymethyl)durene, were prepared. Infrared and nuclear magnetic resonance spectra were used to characterize the unsaturated polyester resins obtained qualitatively and quantitatively. The average‐number molecular weight (M−n) was determined by end‐group analysis. These polyesters were found to cure with styrene at room temperature. The thermal behavior of the styrenated polyesters was studied via thermogravimetrical analysis and differential scanning calorimetry (TGA and DSC). © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3388–3398, 2001
Medical neurobiology: Do we teach neurobiology in a format that is relevant to the clinical setting?
Authors: Haines Duane E. , Hutchins James B. , Lynch James C.
Published: August 2002

During a period of unprecedented growth in technology that allows imaging of the body in elegant detail, anatomy as a discipline has, in some instances, become marginalized. This may be seen in a reduction of time allotted to anatomy, reduction or elimination of laboratory experiences, or shifting of anatomy teaching to clinical departments. One potential cause of this marginalization is the fact that anatomy is frequently taught in a format that is not useful in, or even applicable to, the clinical setting. At the University of Mississippi Medical Center, the Medical Neurobiology course stresses the functional anatomy of the brain, especially the brainstem, in a format that is directly transferable to the clinical setting. These approaches include (1) using a small neurology book as one of the required texts in the course; (2) extensive use of magnetic resonance imaging (MRI) and computed tomography (CT) as an integral part of the instructional approach; (3) teaching external and internal anatomy of the brain, particularly the brainstem and spinal cord, in a “clinical orientation” that reflects how these central nervous system (CNS) regions are viewed in the clinical setting; (4) teaching nuclei and tracts in images of stained sections and correlating this information with comparable MRI and CT images; and (5) using a large series (75 images) of vascular drawings and clinical cases, all in clinical orientation. The clinical applicability of the basic science information, therefore, is continuously reinforced and extended. It is suggested that teaching anatomy and anatomical concepts in formats that are more obviously useful in, and applicable to, the clinical setting will enhance the value of this basic science in the medical curriculum. Anat Rec (New Anat) 269:99–106, 2002. © 2002 Wiley‐Liss, Inc.
Effects of brefeldin‐A: Potent inhibitor of intracellular protein transport on ultrastructure and resorptive function of cultured osteoclasts
Authors: Sahara Takako , Sasaki Takahisa
Published: August 2002

Brefeldin‐A (BFA) is a specific and potent inhibitor of the intracellular transport of clathlin‐uncoated transitional vesicles from the cisterns of rough‐surfaced endoplasmic reticulum (RER) to the Golgi lamellae. This study was designed to clarify the effects of BFA on ultrastructure, subcellular localization of vacuolar‐type H+‐ATPase and a lysosomal cysteine proteinase, cathepsin K, in cultured osteoclasts and their resorptive function. H+‐ATPase and cathepsin K are the most important enzymes for decalcification of apatite crystals and degradation of type‐I collagen, respectively. In control cultures without BFA, osteoclasts were structurally characterized by the development of broad ruffled borders and clear zones, and formed many resorption lacunae in cocultured dentine slices. In BFA‐treated cultures, osteoclasts lacked ruffled borders, and the cytoplasm was filled with regular‐size and extremely large pale vacuoles over 2 μm in diameter, which were produced by fusion of adjacent vacuoles. BFA did not, however, inhibit clear zone formation and adhesion of osteoclasts to dentine slices. Resorption lacuna formation was markedly diminished by BFA treatment. Although H+‐ATPase and cathepsin K were strongly expressed in osteoclast ruffled borders in control cultures, BFA treatment altered the subcellular localization and decreased the expression of these molecules. In BFA‐treated cultures, H+‐ATPase immunoreaction in osteoclasts was observed along the limiting membranes of some, but not all, regular‐size pale vacuoles, but neither in extremely large vacuoles nor along the smooth plasma membranes facing the dentine slices. Similarly, cathepsin K was localized within lysosomes and some regular‐size pale vacuoles, but its secretion toward the dentine slices through the ruffled borders was strongly inhibited by BFA treatment. These results suggest that 1.) formation of the osteoclast ruffled borders and their resorptive function are closely associated with the intracellular transport of these molecules from the RER cisterns and the Golgi lamellae to the ruffled borders, and 2.) both H+‐ATPase and cathepsin K are selectively transported to the ruffled border membranes by pale vacuoles. Anat Rec 263:127–138, 2001. © 2001 Wiley‐Liss, Inc.
Comparative and functional anatomy of the mammalian lumbar spine
Authors: Boszczyk Bronek M. , Boszczyk Alexandra A. , Putz Reinhard
Published: August 2002

As an essential organ of both weight bearing and locomotion, the spine is subject to the conflict of providing maximal stability while maintaining crucial mobility, in addition to maintaining the integrity of the neural structures. Comparative morphological adaptation of the lumbar spine of mammals, especially in respect to locomotion, has however received only limited scientific attention. Specialised features of the human lumbar spine, have therefore not been adequately highlighted through comparative anatomy. Mathematical averages were determined of 14 measurements taken on each lumbar vertebrae of ten mammalian species (human, chimpanzee, orang‐utan, kangaroo, dolphin, seal, Przewalski's horse, cheetah, lama, ibex). The revealed traits are analysed with respect to the differing spinal loading patterns. All examined mammalian lumbar spines suggest an exact accommodation to specific biomechanical demands. The lumbar spine has reacted to flexion in a predominant plane with narrowing of the vertebral bodies in quadrupeds. Torsion of the lumbar spine is withstood by an increase in the transverse distance between the inferior articular processes in the upper lumbar spine in primates, but lower lumbar spine in humans, quadrupeds and the seal. Sagittal zygapophyseal joint areas resist torsion in the seal and humans. Ventral shear is resisted by frontal zygapophyseal joint areas in humans and primates, and dorsal shear by encompassing joints in the ibex. The human fifth lumbar vertebra is remarkable in possessing the largest endplate surface area and the widest distance between the inferior articular processes, as an indicator of the high degree of axial load and torsion in bipedalism. Anat Rec 264:157–168, 2001. © 2001 Wiley‐Liss, Inc.