bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystallization of vulcanizates. II. Low‐temperature crystallization as a function of extent of cure for polybutadiene vulcanized with dicumyl peroxide, tetramethylthiuram disulfide, 2‐bisbenzothiazole‐2,2′‐disulfide, and zinc–accelerator complexes
Authors: Van Der Merwe M. J. , Gradwell M. H. S. , McGill W. J. 
Published: September 2002

AbstractPolybutadiene compounds, vulcanized to various degrees of cure, were crystallized in a density column at −16°C. The percentage crystallinity of vulcanizates was also determined by differential scanning calorimetry where samples, precooled at a programmed rate, were reheated. Curing with peroxides has little effect on either the rate or the extent of crystallization, except at very high crosslink densities, although the induction period prior to crystallization increases progressively with increased crosslink density. Tetramethylthiuram disulfide (TMTD)/sulfur and 2‐bisbenzothiazole‐2,2′‐disulfide (MBTS)/sulfur vulcanizates, cured for progressively longer periods, were found to have lower densities, a result attributed to an increase in free volume occasioned by the formation of accelerator‐terminated pendent groups on the polymer chain. The induction period for crystallization increases and both the rate and the extent of crystallization decrease with extent of cure. These changes are more marked for MBTS vulcanizates that do not crystallize once a gel has formed. Formulations with zinc stearate develop higher crosslink densities and crystallize to a greater extent on cooling, showing the effect of zinc stearate in the crosslinking of pendent groups. The densities of both zinc dimethyldithiocarbamate [Zn2(dmtc)4]– and zinc mercaptobenzothiazole [Zn(mbt)2]–accelerated sulfur vulcanizates increase with cure time, a result attributed to the formation of ZnS in the compounds. Zn2(dmtc)4 compounds crystallize extensively on cooling, pointing to limited main‐chain modification. It is suggested that main‐chain modification in these vulcanizates may comprise cyclic sulfide formation. Zn(mbt)2 compounds crystallize less readily than Zn2(dmtc)4 compounds, but to a greater extent than MBTS/sulfur compounds. The crystallization of the vulcanizates is discussed in terms of vulcanization reactions that give rise to crosslinking with the different formulations used. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2573–2586, 2001
Synthesis and swelling characteristics of poly(4‐vinylpyridine) gels crosslinked by irradiation
Authors: Acar Nermin 
Published: September 2002

AbstractThe effect of irradiation under vacuum on thermal properties and swelling behavior on poly(4‐vinylpyridine) (P4VP) was investigated. The gel percentage in the irradiated P4VP films was determined by Soxhlet extraction. UV spectroscopy was also used to determine sol percentage, which decreased as the radiation dose increased. The changes in thermal properties, such as glass‐transition temperature (Tg), were followed by differential scanning calorimetry before and after Soxhlet extraction. The gels prepared after irradiation were characterized with respect to their swelling properties and network structures. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2609–2614, 2001
A new method for treatment of sol‐gel data in irradiated polymers
Authors: Shyichuk A. V. , Tokaryk G. V. 
Published: September 2002

AbstractA log‐log plot of sol fraction versus dose has been found to be an effective graphical technique to treat sol‐gel analysis data. The treatment procedure is described in detail with an example of radiation crosslinking of linear low‐density polyethylene. Radiation chemical yields both for crosslinking and scission of macromolecules were determined using Monte Carlo simulation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2621–2625, 2001
Cellulose furoate. I. Synthesis in homogeneous and heterogeneous systems
Authors: Hon David N.‐S. , Yan Hui 
Published: September 2002

AbstractCellulose furoate was synthesized via heterogeneous and homogeneous reactions. Cotton cellulose and wood cellulose were used. Lithium chloride/dimethylacetamide solvent was used to dissolve the cellulose for the homogeneous reaction. The esterification reaction between cellulose and 2‐furoyl chloride was systematically studied. It revealed that the activation of cellulose was important for its esterification reaction. Activation by solvent exchange decreased the crystallinity and increased the accessibility of cellulose. X‐ray diffraction analysis showed no significant change in the spectrogram after activation of cellulose. The degree of substitution of cellulose furoate was influenced by the molecular weight of the cellulose, the stoichiometry of the reagents, the acid scavenger, and the reaction time. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2649–2655, 2001
Properties and application of poly(acrylphenylamidrazone‐phenylhydrazide) chelating fiber for enrichment–separation of trace gold and ruthenium from solution samples
Authors: Chang Xijun , Yang Xiulan , Wang Bingtao 
Published: September 2002

AbstractAn ICP‐OES method using a new poly(acrylphenylamidrazone‐phenylhydrazide) chelating fiber to enrich and separate trace Au(III) and Ru(III) ions from solution samples is established. The results show that 50–500 ng/mL of Au or Ru ions can be enriched quantitatively by 0.1 g of the fiber at pH 4, with recoveries > 96%. The ions can be desorbed quantitatively with 10 mL of 4 M HCl and 3.0% CS(NH2)2 solution from the fiber column, with recoveries > 97%, and 200–1000‐fold excesses of Cu(II), Zn(II), Ca(II), Mg(II), Mn(II), Cr(III), Fe(III), Ba(II), and Al(III) caused little interference in the determination of these ions by ICP–OES. The chelating fiber can be reused eight times, and the recoveries are all > 95%. The relative standard deviations for enrichment and determination of 50 ng/mL of Au and Ru are in the range 1.8–1.9% (1.9% for Au and 1.8% for Ru). The recoveries of trace Au and Ru ions added to real waste water and alloy samples are 96–98%. The concentration of each ion found in the alloy samples was in good agreement with that provided by the plant. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2656–2660, 2001
Thermal properties and flame retardance of Al(OH)3/polypropylene composites modified by polypropylene grafting with acrylic acid
Authors: Mai Kancheng , Li Zhengjun , Qiu Yuxin , Zeng Hanmin 
Published: September 2002

AbstractThe effect of polypropylene grafting with acrylic acid, PP‐g‐AA (FPP), on crystallization and melting behavior, thermal degradation, and limiting oxygen index of Al(OH)3/PP composites were investigated. The results indicated that crystallization temperature of PP shifted to high temperature with increasing content of Al(OH)3 because of the interfacial heterogeneous nucleation of Al(OH)3 and further increased by the addition of FPP and with increasing FPP content because of the improvement of the dispersion of Al(OH)3 in PP matrix and the increase in the nucleating sites of Al(OH)3. With adding Al(OH)3 and increasing the content of Al(OH)3, limiting oxygen index values of composites increased and further improved by adding FPP. This is attributed to the presence of an interfacial interaction between FPP and Al(OH)3. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2679–2686, 2001
Immobilization of glucoamylase on the plain and on the spacer arm‐attached poly(HEMA‐EGDMA) microspheres
Authors: Arica M.Yakup , Yavuz Handan , Denizli Adil 
Published: September 2002

AbstractImmobilization glucoamylase onto plain and a six‐carbon spacer arm (i.e., hexamethylene diamine, HMDA) attached poly(2‐hydroxyethylmethacrylate‐ethyleneglycol dimethacrylate) [poly(HEMA‐EGDMA] microspheres was studied. The microspheres were prepared by suspension polymerization and the spacer arm was attached covalently by the reaction of carbonyl groups of poly(HEMA‐EGDMA). Glucoamylase was then covalently immobilized either on the plain of microspheres via CNBr activation or on the spacer arm‐attached microspheres via CNBr activation and/or using carbodiimide (CDI) as a coupling agent. Incorporation of the spacer arm resulted an increase in the apparent activity of the immobilized enzyme with respect to enzyme immobilized on the plain of the microspheres. The activity yield of the immobilized glucoamylase on the spacer arm‐attached poly(HEMA‐EGDMA) microspheres was 63% for CDI coupling and 82% for CNBr coupling. This was 44% for the enzyme, which was immobilized on the plain of the unmodified poly(HEMA‐EGDMA) microspheres via CNBr coupling. The Km values for the immobilized glucoamylase preparations (on the spacer arm‐attached microspheres) via CDI coupling 0.9% dextrin (w/v) and CNBr coupling 0.6% dextrin (w/v) were higher than that of the free enzyme 0.2% dextrin (w/v).The temperature profiles were broader for both immobilized preparations than that of the free enzyme. The operational inactivation rate constants (kiop) of immobilized enzymes were found to be 1.42 × 10−5 min−1 for CNBr coupled and 3.23 × 10−5 min−1 for CDI coupled glucoamylase. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2702–2710, 2001
Study of poly(ethylene oxide) electrolyte with polyurethane/sulfonate side chains
Authors: Wang Xinling , Fang Bin , Wang Lei , Tang Xiaozhen , Chang Feng‐Chih 
Published: September 2002

AbstractSulfonated dimethyl fumarate (SDMF) was prepared. Poly(ethylene oxide) (PEO) with sodium sulfonate side chains (SPEO) was synthesized by transesterification between SDMF and PEO with molecular weights of 200, 400, 600, 800, and 1000. The SPEO was subsequently mixed as a plasticizer with PEO polyurethane (PU). Samples were characterized by elemental analysis, FTIR, 1H‐NMR, gel permeation chromatography, and impedance analysis. The mixture exhibited a homogeneous domain. The maximum conductivity of the CPU1000/SPEO600 was 2.6 × 10−7 S cm−1 at room temperature. The relation between the ionic conductivity and the temperature was in agreement with the Arrhenius equation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 541–545, 2001
Isothermal crystallization and spherulite structure of partially miscible polypropylene–linear low‐density polyethylene blends
Authors: Li Jun , Shanks Robert A. , Long Yu 
Published: September 2002

AbstractPolypropylene (PP) was blended with a linear low‐density polyethylene (LLDPE, containing 5% hexene comonomer) over a composition range of 10–90% of PP. The crystallization and morphology of the PP–LLDPE blends were studied by differential scanning calorimetry (DSC), polarized optical microscopy with a hot stage (HSOM), and scanning electron microscopy (SEM). In particular, the isothermal crystallization of PP in molten LLDPE was investigated. It was observed that the crystallization and melting behavior of PP and LLDPE changed in the blends, indicating that there was some degree of miscibility between the PP and the LLDPE. A depression of the equilibrium melting temperature (T) of PP in the blends with no more than 15% of PP confirmed that PP was miscible with LLDPE at and below 15% of PP. In addition, a drastic decrease in T from the 25% PP blend to the 20% blend led us to conclude that the miscible behavior between PP and LLDPE became favorable at a PP concentration of 20%. The optical microscopic images showed that, in the blends with 10 and 15% of PP, the PP crystallized as open‐armed diffuse spherulites, similar to those in the miscible blends. In contrast, the PP crystallized in a phase‐separated matrix or droplets with more than 25% of PP, when obvious phase separation occurred. The SEM image revealed that the PP lamella was able to penetrate the PP and LLDPE phase boundary and grow in the LLDPE phase. The above results displayed that the PP dissolved in the LLDPE, and, particularly, when the PP concentration was below 20%, the dissolution was substantial. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 628–639, 2001
Temporomandibular joint in miniature pigs: Anatomy, cell replication, and relation to loading
Authors: Herring Susan W. , Decker Jay D. , Liu Zi‐Jun , Ma Tsun 
Published: September 2002

AbstractThe mechanical environment is a regulator of growth and adaptation of the musculoskeletal system, including joints. Although pigs (Sus scrofa) are used frequently as models for temporomandibular joint (TMJ) dysfunction, no systematic description of microanatomy exists for this species. We injected the thymidine analog 5‐bromo‐2′‐deoxyuridine (BrdU) into 10‐ to 11‐month‐old miniature pigs that were undergoing measurements of TMJ bone strain. Ten hr later, the animals were sacrificed and their heads were perfused. Histological sections were used to map the distribution of replicating cells. Additional observations were made on gross dissections of jaw joints obtained from an abattoir. The pig TMJ is better supported than that of humans laterally and medially, but more vulnerable posteriorly. The posterior attachment area of the intra‐articular disc is fibro‐fatty rather than vascular, as in humans. Cartilage lines the articular eminence as well as the condylar surface. At the posterosuperior region of the condyle, the cartilage ends abruptly and is replaced by an invaginating, actively replicating periosteum. Almost all of the BrdU‐labeled cells resided in the prechondroblastic zones. The condyle had more replicating cells than did the eminence (P < 0.02), but lateral and medial locations did not differ in either element. In sagittal sections, the condyle had more replicating cells posteriorly (P < 0.001), but no A‐P differences were seen in the eminence. Comparisons of these data with data on bone strain indicate that increased loading is negatively associated with cell replication. Anat Rec 266:152–166, 2002. © 2002 Wiley‐Liss, Inc.
Experimental confirmation of the sheep model for studying the role of calcified fibrocartilage in hip fractures and tendon attachments
Authors: Shea Jill E. , Hallows Rhett K. , Bloebaum Roy D. 
Published: September 2002

AbstractResearch has shown that there is a dramatic increase in the fractional area of calcified fibrocartilage from tendon and capsular insertions on the human femoral neck (Vajda and Bloebaum, 1999; Shea et al., 2001b). Additional information regarding the properties of the proximal femur's cortical shell, gained from the use of an animal model, may result in a better understanding of elderly hip fracture since the cortical shell is a significant contributor to the strength of the proximal femur. The objective of the present study was to determine if the greater trochanter's tendon insertions of the human, rat, and sheep differ in terms of morphology and mineralization. The tendons of the greater trochanter of the human, rat, and sheep were observed to insert via a fibrocartilage insertion. The mineral content of the human and sheep calcified fibrocartilage was significantly higher than that of the rat calcified fibrocartilage (P < 0.01). Additionally, the mineral content of the rat cortical bone was significantly higher than that of the human cortical bone (P < 0.01). The mineral content of the calcified fibrocartilage and bone of the human and sheep were not statistically different from each other. There were also more similarities between the bone structure and lacunae density of the human and sheep than between the human and the rat. This suggests that the tendon insertions of the sheep are a better model than the tendon insertions of the rat for the investigation of calcified fibrocartilage in elderly hip fractures. Anat Rec 266:177–183, 2002. Published 2002 Wiley‐Liss, Inc.
Squamotympanic fissure in the Ngandong and Sambungmacan hominids: A reply to Delson et al.
Authors: Durband Arthur C. 
Published: September 2002

AbstractIn the present study the course of the squamotympanic fissure of the mandibular fossa is examined in several fossil hominid specimens. While previous work by several authors had found that the course of this fissure was potentially autapomorphic for the Ngandong and Sambungmacan fossil samples from Indonesia, a more recent study performed by Delson et al. (Anat Rec 2001; 262:380–397) reported that a number of other fossils, including OH 9, Sangiran 4 and 17, and KNM WT 15000 were similar to the Ngandong and Sambungmacan specimens in the expression of this feature. To test these findings, those specimens purported to share similarities with Ngandong and Sambungmacan were examined. The results of this study indicate clearly differing morphologies between the Ngandong and Sambungmacan fossils, on the one hand, and the four African and Indonesian fossils named by Delson et al. (2001). Hence, the course of the squamotympanic fissure remains a potentially autapomorphic feature separating the Ngandong and Sambungmacan samples from the remaining specimens allocated to Homo erectus. Anat Rec 266:138–141, 2002. © 2002 Wiley‐Liss, Inc.
Trust, but verify: The necessity of empirical verification in quantitative neurobiology
Authors: Farel Paul B. 
Published: September 2002

AbstractThe preferred procedure for estimating neuron number has been the subject of intense discussion. Sampling error, systematic bias, and the physical properties of the tissue examined all contribute to the possibility that estimates may not reflect actual neuron number. Even when restricting analysis to a particular, well‐defined structure such as dorsal root ganglia, these factors act in a manner that varies with maturity of the animal, species, fixation, processing, and neuron size. These considerations reinforce the necessity of comparing estimates with the actual number of neurons as determined by three‐dimensional reconstructions. Anat Rec (New Anat) 269:157–161, 2002. © 2002 Wiley‐Liss, Inc.
Common patterns of facial ontogeny in the hominid lineage
Authors: Rogers Ackermann Rebecca , Krovitz Gail E. 
Published: September 2002

AbstractRecent evaluation of Neanderthal and modern human ontogeny suggests that taxon‐specific features arose very early in development in both lineages, with early, possibly prenatal, morphological divergence followed by parallel postnatal developmental patterns. Here we use morphometric techniques to compare hominoid facial growth patterns, and show that this developmental phenomenon is, in fact, not unique to comparisons between Neanderthals and modern humans but extends to Australopithecus africanus and to the hominoid lineage more broadly. This finding suggests that a common pattern of juvenile facial development may be more widespread and that the roots of ontogenetically early developmental differentiation are deep—perhaps predating the ape/human split of 6+ million years ago. Anat Rec (New Anat) 269:142–147, 2002. © 2002 Wiley‐Liss, Inc.
A pulse‐chase study tracking the conversion of macrophage‐endocytosed serum amyloid A into extracellular amyloid
Authors: Kluve‐Beckerman Barbara , Manaloor John J. , Liepnieks Juris J. 
Published: September 2002

AbstractObjectiveTo determine whether serum amyloid A (SAA) is internalized by and processed in macrophages en route to deposition as extracellular amyloid.MethodsSAA was tracked in cultures of peritoneal macrophages, using a pulse‐chase protocol. Macrophages were pulsed with either fluorescently (with Texas Red) tagged SAA (TxR‐SAA) or iodinated SAA (125I‐SAA). Cells were then rinsed and shifted to chase medium containing unlabeled SAA and amyloid‐enhancing factor (AEF) to induce amyloid formation. At selected times, TxR‐SAA in living cells was observed by confocal scanning microscopy. 125I‐SAA was visualized and quantified in cell lysates and medium by sodium dodecyl sulfate–polyacrylamide gel electrophoresis and phosphorimaging. The presence of amyloid was confirmed by Congo red staining.ResultsConfocal microscopy immediately after the pulse revealed TxR‐SAA in endosomal vesicles, with no extracellular or cell surface accumulation. After 24 hours and 72 hours of chase, virtually all TxR‐SAA remained intracellular. By 10 days, extracellular fluorescence was very strong, indicating that SAA had moved out of cells. Congo red staining revealed amyloid colocalized with areas of extracellular fluorescence. Experiments using 125I‐SAA showed that while 90–95% of internalized 125I‐SAA was degraded within 24 hours, 5–10% persisted as intact SAA or SAA peptides. Immediately after the pulse, SAA was full‐length, but within 24 hours, discrete 125I‐SAA peptides were seen. Each peptide had an intact SAA amino‐terminus, as expected for AA protein. Amyloid was detected in cultures as early as 24 hours after initiation of treatment with SAA and AEF and appeared to be intracellular.ConclusionThe results of this study provide direct evidence that SAA internalized by and processed in macrophages forms extracellular amyloid. Based on the presence of 125I‐AA protein in macrophage lysates prior to the appearance of extracellular TxR‐labeled amyloid, it was concluded that cleavage of SAA to AA occurs intracellularly.
Differences in idiopathic inflammatory myopathy phenotypes and genotypes between Mesoamerican Mestizos and North American Caucasians: Ethnogeographic influences in the genetics and clinical expression of myositis
Authors: Shamim Ejaz A. , Rider Lisa G. , Pandey Janardan P. , O'Hanlon Terrance P. , Jara Luis J. , Samayoa Eduardo A. , Burgos‐Vargas Ruben , Vazquez‐Mellado Janitzia , Alcocer‐Varela Jorge , Salazar‐Paramo Mario , Kutzbach Abraham Garcia , Malley James D. , Targoff Ira N. , La Torre Ignacio Garcia‐De , Miller Frederick W. 
Published: September 2002

AbstractObjectiveAs part of a larger, worldwide study of the ethnogeography of myositis, we evaluated the clinical, serologic, and immunogenetic features of Mestizo (Mexican and Guatemalan) and North American Caucasian patients with idiopathic inflammatory myopathy (IIM).MethodsClinical manifestations, autoantibodies, HLA‐DRB1 and DQA1 alleles, and immunoglobulin Gm/Km allotypes were compared between 138 Mestizos with IIM and 287 Caucasians with IIM, using the same classification criteria and standardized questionnaires.ResultsIIM in Mestizo patients was characterized by a higher proportion of dermatomyositis (69% of adult Mestizos versus 35% of adult Caucasians; P < 0.001) and anti‐Mi‐2 autoantibodies (30% versus 7% of adults, respectively, and 32% versus 4% of children, respectively; P < 0.01). Genetic risk factors also differed in these populations. Whereas Mestizos had no HLA risk factors for IIM, HLA‐DRB1*0301, the linked allele DQA1*0501, and DRB1 alleles sharing the first hypervariable region motif 9EYSTS13 were major risk factors in Caucasian patients with IIM. Furthermore, different HLA‐DRB1 and DQA1 alleles were associated with anti‐Mi‐2 autoantibodies (DRB1*04 and DQA1*03 in Mestizos and DRB1*07 and DQA1*02 in Caucasians). Immunoglobulin γ‐chain allotypes Gm(1), Gm(17) (odds ratio for both 11.3, P = 0.008), and Gm(21) (odds ratio 7.3, P = 0.005) and κ‐chain allotype Km(3) (odds ratio 7.3, P = 0.005) were risk factors for IIM in Mestizos; however, no Gm or Km allotypes were risk or protective factors in Caucasians. In addition, Gm and Km phenotypes were unique risk factors (Gm 1,3,17 5,13,21 and Gm 1,17 23 21 and Km 3,3) or protective factors (Km 1,1) for the development of myositis and anti‐Mi‐2 autoantibodies (Gm 1,2,3,17 23 5,13,21) in adult Mestizos.ConclusionIIM in Mesoamerican Mestizos differs from IIM in North American Caucasians in the frequency of phenotypic features and in the immune‐response genes predisposing to and protecting from myositis and anti‐Mi‐2 autoantibodies at 4 chromosomal loci. These and other data suggest the likelihood that the expression of IIM is modulated by different genes and environmental exposures around the world.