bluuebunny/crossref_metadata_2025_split huggingface dataset:
Peroxomonosulphate initiated graft copolymerization of o‐toluidine onto nylon 6 and wool fibers—A kinetic approach
Authors: Anbarasan R. , Jayaseharan J. , Gopalan A. 
Published: October 2002

AbstractChemical polymerization of o‐toluidine (OT) in the presence of nylon 6 and wool fibers initiated by peroxomonosulphate (PMS) in an aqueous acidic medium was carried out under nitrogen atmosphere. During the polymerization process, graft copolymers were formed along with homopolymers of OT. A procedure is given for the separation of poly(o‐toluidine) (POT) grafted fiber from the homopolymer. Rate of homopolymerization (Rh), rate of grafting (Rg), percentage grafting, and percentage grafting efficiency were determined. Rate constants were evaluated from the experimental results. The chemical grafting of POT onto nylon 6 and wool fibers was confirmed through Fourier transform infrared (FTIR) spectroscopy and electrical conductivity measurements. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2317–2326, 2002
Studies on blends of high‐density polyethylene and polypropylene produced by oscillating shear stress field
Authors: Zhang Gong , Fu Qiang , Shen Kaizhi , Jian Long , Wang Yong 
Published: October 2002

AbstractTensile strength and morphology of blends of high‐density polyethylene (HDPE) and polypropylene (PP) obtained by oscillating packing injection molding were investigated via Universal Testing Machine, DSC, and SAXS. Tensile strength is greatly enhanced from 24.5 MPa to more than 90 MPa for pure HDPE and for blends with PP content less than 10 wt %. There exists a sharp decrease of tensile strength when PP content is more than 10 wt %. The shear‐induced morphologies with core in the center, oriented zone surrounding the core and skin layer are observed in the cross‐section areas of the samples. Interestingly, a sharp decrease of oriented zone is seen when PP content is more than 10 wt %, associated with the sharp decrease of tensile strength. DSC result shows double melting peaks with a high‐temperature melting peak that is not present in the endotherm obtained from the central core and obtained from the samples by static packing injection molding, which indicates the existence of shish‐kebab structure in the oriented zone. However, there is no difference of crystallinity between the samples by oscillating and by static packing injection molding. SAXS was used to analyze the complicated morphologies induced by shear stress, and results show that the crystal thickness could be greatly increased under shear stress. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 58–63, 2002
Free radical grafting of itaconic acid and glycidyl methacrylate onto PP initiated by organic peroxides
Authors: Pesetskii S. S. , Jurkowski B. , Makarenko O. A. 
Published: October 2002

AbstractComparative analysis was conducted to learn the grafting of itaconic acid (IA) and glycidyl methacrylate (GMA) onto polypropylene (PP) in the course of reactive extrusion. Seven organic peroxides, which satisfactorily dissolve in PP, but do not dissolve in the monomer, were used to initiate free‐radical reactions. The grafting of IA and GMA onto PP initiated by certain peroxides gave approximately equal amounts of grafted product. It was learned that the nature of peroxide initiators is decisive for grafting efficiency and degree of macromolecular degradation. To ensure a high yield of grafted product, it is advisable to use peroxides, which have thermodynamic affinity with PP and the temperature range of decomposition of which corresponds to the thermal regime of reactive extrusion. Di(tert‐butyl peroxy‐isopropyl)‐benzene (P‐14) appeared to meet for the most these requirements for grafting both GMA and IA. Grafting is accompanied by β‐decomposition of the chains irrespective of the type of peroxide and monomer used; hence, the MFI increases. A considerable rise in MFI was observed at a minimum peroxide concentration (0.1wt %). Degradation of PP during modification eases its crystallization from the melt. In this case the crystallization temperature is 5 to 8.5°C higher than of the original PP, and the crystallinity degree increases by 20 to 60%. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 64–72, 2002
Phase behavior and morphology in blends of poly(L‐lactic acid) and poly(butylene succinate)
Authors: Park Jun Wuk , Im Seung Soon 
Published: October 2002

AbstractBlends of poly(L‐lactic acid) (PLA) and poly(butylene succinate) (PBS) were prepared with various compositions by a melt‐mixing method and the phase behavior, miscibility, and morphology were investigated using differential scanning calorimetry, wide‐angle X‐ray diffraction, small‐angle X‐ray scattering techniques, and polarized optical microscopy. The blend system exhibited a single glass transition over the entire composition range and its temperature decreased with an increasing weight fraction of the PBS component, but this depression was not significantly large. The DSC thermograms showed two distinct melting peaks over the entire composition range, indicating that these materials was classified as semicrystalline/semicrystalline blends. A depression of the equilibrium melting point of the PLA component was observed and the interaction parameter between PLA and PBS showed a negative value of −0.15, which was derived using the Flory–Huggins equation. Small‐angle X‐ray scattering revealed that, in the blend system, the PBS component was expelled out of the interlamellar regions of PLA, which led to a significant decrease of a long‐period, amorphous layer thickness of PLA. For more than a 40% PBS content, significant crystallization‐induced phase separation was observed by polarized optical microscopy. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 647–655, 2002
Homogeneous fluorescent labeling of cationic polyacrylamides
Authors: Tanaka Hiroo , Swerin Agne , Ödberg Lars , Tanaka Masayoshi 
Published: October 2002

AbstractA number of fluorescently labeled polymers have already been prepared. Since these polymers have usually been synthesized by copolymerization, the distribution of fluorescent groups will in such a case be heterogeneous because monomers always have different reactivity ratios. In this article, the preparation of fluorescently labeled cationic polyacrylamides (C‐PAM) with homogeneous distributions of both fluorescent and cationic groups is described. Four fluorescently labeled C‐PAM with isoindol, pyrene, anthracene, and dansyl groups were prepared in the homogeneous reaction system. These polymers were water soluble. Their wavelengths for maximum emission were in order of the above 380, 382 (smaller peak at 400), 435, and 540 nm, which thus covered a wide wavelength range. It is noteworthy that C‐PAM with pyrene and anthracene groups have little fluorescence intensity at 540 nm, which is the maximum emission wavelength for C‐PAM with dansyl group, making an accurate determination of the two polymers in the same solution possible. Even at the low degree of labeling, the detection limit of polymers is very low (approximately 1 ppm). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 672–675, 2002
Synthesis and characterization of a positive‐working, aqueous‐base‐developable photosensitive polyimide precursor
Authors: Hsu Steve Lien‐Chung , Lee Po‐I , King Jinn‐Shing , Jeng Jyh‐Long 
Published: October 2002

AbstractA positive‐working, aqueous‐base‐developable photosensitive polyimide precursor based on poly(amic ester)‐bearing phenolic hydroxyl groups and a diazonaphthoquinone photosensitive compound was developed. The poly(amic ester) was prepared from a direct polymerization of 2,2′‐bis‐(3‐amino‐4‐hydroxyphenyl)hexafluoropropane and bis(n‐butyl)ester of pyromellitic acid in the presence of phenylphosphonic dichloride as an activator. Subsequently, the thermal imidization of the poly(amic ester) precursor at 300°C produced the corresponding polyimide. The inherent viscosity of the precursor polymer was 0.23 dL/g. The cyclized polyimide showed a glass‐transition temperature at 356°C and a 5% weight loss at 474°C in nitrogen. The structures of the precursor polymer and the fully cyclized polymer were characterized by Fourier transform infrared spectroscopy and 1H‐NMR. The photosensitive polyimide precursor containing 25 wt % diazonaphthoquinone photoactive compound showed a sensitivity of 150 mJ/cm2 and a contrast of 1.65 in a 3 μm film with 1.25 wt % tetramethylammonium hydroxide developer. A pattern with a resolution of 10 μm was obtained from this composition. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 352–358, 2002
Oxazoline‐containing compatibilizers for polyamide/SAN and polyamide/ABS blends
Authors: Liu Xiaodong , La Mantia Francesco , Scaffaro Roberto 
Published: October 2002

AbstractPolyamide (PA) and acrylonitrile/butadiene/styrene copolymer (ABS) may appear as a mixture in the recycled plastic stream. The incompatibility of these blends results in a blend with poor mechanical properties. The aim of this work is to partially convert the nitrile groups of the acrylonitrile/styrene copolymer (SAN) into oxazoline groups by reaction with aminoethanol (AE). Such modified SAN (SAN‐m) can react with the amine or carboxylic acid end groups of PA, and therefore used as compatibilizers for blends of PA with ABS. SAN‐m was found to reduce the SAN‐domain size in the PA/SAN‐blends. The initial acrylonitrile content of SAN‐m had a strong influence on the degree of conversion into oxazoline groups and on the compatibilizing effect. Mechanical properties of SAN‐m compatibilized PA/ABS blends were investigated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 449–455, 2002
Reactions of adenine with ethylene oxide and propylene oxide
Authors: Lubczak Renata 
Published: October 2002

AbstractReactions leading to thermostable polyetherols containing purine rings were studied. Products of reaction of adenine and an excess of the oxiranes were analyzed by proton nuclear magnetic resonance and infrared spectroscopies. The physical properties of some of the products were determined. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 489–497, 2002
Localization of the transmembrane proteoglycan syndecan‐4 and its regulatory kinases in costameres of rat cardiomyocytes: A deconvolution microscopic study
Authors: VanWinkle W. Barry , Snuggs Mark B. , De Hostos Eugenio L. , Buja L. Maximilian , Woods Anne , Couchman John R. 
Published: October 2002

AbstractSyndecan‐4 (syn‐4), a transmembrane heparan sulfate‐containing proteoglycan, is unique among the four members of the syndecan family in its specific cellular localization to complex cytoskeletal adhesion sites, i.e., focal adhesions. During early phenotypic redifferentiation of neonatal cardiomyocytes in culture, immunolocalization reveals syn‐4 to be heavily concentrated in the perinuclear endoplasmic reticulum‐Golgi region, with little found at the peripheral regions. Subsequently, syn‐4 becomes localized to a cytoskeletal adhesion complex unique to striated muscle, the costamere. Soon after redifferentiation of myofibrils in cultured neonatal cardiomyocytes, syn‐4 is present only in costameres, not in focal adhesions. In cultured adult cardiomyocytes, it is present in both costameres and focal adhesions—the latter in two distinct regions of the spread cardiomyocytes, reflecting localization with two types of actin‐containing filaments. The fact that syn‐4 is observed early in the costameric regions, as opposed to later in the focal adhesions, suggests that it may play an initial role in early adhesion/signal transduction mechanisms in close proximity to the contractile apparatus, as well as in transmission of contractile force to the collagenous extracellular matrix (ECM) which surrounds the cardiac myofibers in situ. With respect to possible regulatory mechanisms of syn‐4, we localized syn‐4 with both the ϵ isoform of protein kinase C and the tyrosine kinase pp60csrc in costameric regions. These findings suggest that syn‐4 may not only play a role in cellular adhesion and contractile force transmission, it may also, through ser, thr, and tyr phosphorylation, be part of an interactive signal transduction mechanism in myocardial functioning via these adhesive cytoskeletal complexes. Anat Rec 268:38–46, 2002. © 2002 Wiley‐Liss, Inc.
Purification and characterization of nucleoside diphosphate kinase from the brain of Bombyx mori
Authors: Uno Tomohide , Ueno Mayumi , Kikuchi Michiko , Aizono Yasuo 
Published: October 2002

AbstractNucleoside diphosphate kinase in the brain of Bombyx mori was purified by ammonium sulfate fractionation, and a sequence of chromatographies on DEAE‐Cellulofine, hydroxyapatite, Mono‐S, and Mono‐Q column. The purified enzyme preparation was found to be electrophoretically homogeneous on SDS‐PAGE, and its molecular mass was determined to be 18 kDa. The purified protein was digested and the amino acid sequences of resulting peptides were determined. The enzyme showed high similarity to the amino acid sequences of the Drosophila NDP kinase. The enzyme showed NDP kinase activity and mediated the phosphorylation of myelin basic protein. Gel filtration and Hill plot analysis indicate that the purified NDP kinase forms a tetramer and shows little interaction among substrates. Dephosphorylation of NDP kinase by bacterial alkaline phosphatase increased NDP kinase activity. This result indicates that phosphorylation of NDP kinase represses NDP kinase activity. Arch. Insect Biochem. Physiol. 50:147–155, 2002. © 2002 Wiley‐Liss, Inc.
Juvenile hormone stimulated tyrosine kinase‐mediated protein phosphorylation in the CNS of the silk worm, Bombyx mori
Authors: Arif A. , Shanavas A. , Murthy Ch. R. K. , Dutta‐Gupta Aparna 
Published: October 2002

AbstractIn vitro studies with the larval CNS of the silkworm, Bombyx mori revealed the phosphorylation of a 48‐kDa protein, which was not dependent on cyclic nucleotides. Studies also revealed modest phosphorylation of this protein by a calcium‐dependent but calmodulin‐independent mechanism. However, phosphorylation of this protein was greatly enhanced in the presence of juvenile hormone (JH) I by a calcium‐independent mechanism. This stimulatory effect of JH was seen in both homogenates as well as in intact CNS of Bombyx. Immunoblotting studies revealed the cross‐reaction of this 48‐kDa protein with phosphotyrosine monoclonal antibody and the phosphorylation of this protein was inhibited by genistein. This study suggests that the 48‐kDa protein is a substrate for tyrosine kinase. The phosphorylation of this protein was also observed in other larval tissues such as salivary gland, fat body, and epidermis of Bombyx. Arch. Insect Biochem. Physiol. 50:139–146, 2002. © 2002 Wiley‐Liss, Inc.
Two juvenile hormone suppressible storage proteins may play different roles inHyphantria cuneaDrury
Authors: Cheon Hyang‐Mi , Hwang Su‐Jeong , Kim Hong‐Ja , Jin Byung Rae , Chae Kwon‐Seok , Yun Chi‐Young , Seo Sook‐Jae 
Published: October 2002

AbstractWe isolated and sequenced cDNA clones corresponding to two storage proteins (HcSP‐1 and HcSP‐2) from fall webworm,Hyphantria cunea. The cDNAs for HcSP‐1 (2,337 bp) and HcSP‐2 (2,572 bp) code for 753 and 747 residue proteins with predicted molecular masses of 88.3 and 88.5 kDa, respectively. The calculated isoelectric points are pI = 8.4 (HcSP‐1) and 7.6 (HcSP‐2). Multiple alignment analysis of the amino acid sequence revealed that HcSP‐1 is most similar to SL‐1 fromS. litura(73.8% identity) and other methionine‐rich hexamers, whereas HcSP‐2 is most similar to the SL‐2 α subunit fromS. litura(74.8% identity) and other moderately methionine‐rich hexamers. The two storage proteins fromH. cuneashared only 38.4% identity with one another. According to both phylogenetic analyses and the criteria of amino acid composition, HcSP‐1 belongs to the subfamily of Met‐rich storage proteins (6% methionine, 10% aromatic amino acid), and HcSP‐2 belongs to the subfamily of moderately methionine‐rich storage proteins (3.2% methionine, 12.9% aromatic amino acid). Topical application of the JH analog, methoprene, after head ligation of larvae, suppressed transcription of the SP genes, indicating hormonal effects at the transcriptional level. The HcSP‐1 transcript was detected by Northern blot analysis in Malpighian tubule, testis, and ovary, in addition to fat body where it was most abundant. The HcSP‐2 transcript was detected only in fat body and Malpighian tubule. The accumulation of HcSP‐1 in ovary and HcSP‐2 in Malpighian tubule might be related to differential functions in both organs. Arch. Insect Biochem. Physiol. 50:157–172, 2002. © 2002 Wiley‐Liss, Inc.
Inadequately low serum levels of steroid hormones in relation to interleukin‐6 and tumor necrosis factor in untreated patients with early rheumatoid arthritis and reactive arthritis
Authors: Straub Rainer H. , Paimela Leena , Peltomaa Ritva , Schölmerich Jürgen , Leirisalo‐Repo Marjatta 
Published: October 2002

AbstractObjectiveTo compare levels of steroid hormones in relation to cytokines and to study levels of cortisol or dehydroepiandrosterone (DHEA) in relation to other adrenal hormones in untreated patients with early rheumatoid arthritis (RA) and reactive arthritis (ReA) compared with healthy controls.MethodsIn a retrospective study with 34 RA patients, 46 ReA patients, and 112 healthy subjects, we measured serum levels of interleukin‐6 (IL‐6), tumor necrosis factor (TNF), adrenocorticotropic hormone (ACTH), cortisol, 17‐hydroxyprogesterone (17‐OH‐progesterone), androstenedione (ASD), DHEA, and DHEA sulfate (DHEAS).ResultsRA patients had higher serum levels of IL‐6, TNF, cortisol, and DHEA compared with ReA patients and healthy subjects, but no difference was noticed with respect to ACTH and DHEAS. However, in RA and ReA patients compared with healthy subjects, levels of ACTH, cortisol, ASD, DHEAS, and 17‐OH‐progesterone were markedly lower in relation to levels of IL‐6 and TNF. Furthermore, the number of swollen joints correlated inversely with the ratio of serum cortisol to serum IL‐6 in RA (RRank = −0.582, P = 0.001) and, to a lesser extent, in ReA (RRank = −0.417, P = 0.011). In RA patients, the mean grip strength of both hands was positively correlated with the ratio of serum cortisol to serum IL‐6 (RRank = 0.472, P = 0.010). Furthermore, in these untreated patients with RA and ReA, there was a relative decrease in the secretion of 17‐OH‐progesterone, ASD, and DHEAS in relation to DHEA and cortisol. This indicates a relative predominance of the nonsulfated DHEA and cortisol in relation to all other measured adrenal steroid hormones in the early stages of these inflammatory diseases.ConclusionThis study indicates that levels of ACTH and cortisol are relatively low in relation to levels of IL‐6 and TNF in untreated patients with early RA and ReA compared with healthy subjects. The study further demonstrates that there is a relative increase of DHEA and cortisol in relation to other adrenal hormones, such as DHEAS. This study emphasizes that adrenal steroid secretion is inadequately low in relation to inflammation. Although changes in hormone levels are similar in RA and ReA, alteration of steroidogenesis is more pronounced in RA patients than in ReA patients.
Increased urinary F2‐isoprostanes in systemic sclerosis, but not in primary Raynaud's phenomenon: Effect of cold exposure
Authors: Cracowski Jean‐Luc , Carpentier Patrick H. , Imbert Bernard , Cachot Sandrine , Stanke‐Labesque Françoise , Bessard Janine , Bessard Germain 
Published: October 2002

AbstractObjectiveF2‐isoprostanes are free radical‐dependent arachidonic acid metabolites that are used as clinical markers of lipid peroxidation in systemic sclerosis (SSc) and other microvascular diseases. The objectives of this study were to determine whether the basal urinary levels of F2‐isoprostane in SSc patients differ from those in patients with primary Raynaud's phenomenon (RP) and to investigate whether F2‐isoprostane formation correlates with the cutaneous microvascular perfusion decrease following cold exposure in SSc patients, patients with primary RP, and healthy controls.MethodsEleven women with RP secondary to SSc, 11 women with primary RP, and 11 healthy women were exposed to decreasing room temperature, from 25°C to 15°C, for 40 minutes. Urine samples were obtained before and after the test for gas chromatography/electronic impact mass spectrometry quantification of 15‐F2t‐isoprostane (15‐F2t‐IsoP; also called isoprostaglandin F2α type III). Cutaneous blood flow was monitored using a laser Doppler perfusion imager.ResultsThe mean ± SEM urinary 15‐F2t‐IsoP levels at baseline in SSc patients (178 ± 32 pmoles/mmole of creatinine) were 1.9 times higher than those in healthy controls (95 ± 11 pmoles/mmole of creatinine) and 1.7 times higher than those in patients with primary RP (107 ± 19 pmoles/mmole of creatinine) (P < 0.05 for controls and patients with primary RP versus SSc patients). No significant correlation was found between basal urinary 15‐F2t‐IsoP levels and the temperature or cutaneous blood flow decrease in response to the whole‐body cooling. Furthermore, the 15‐F2t‐IsoP response to the cooling test was not correlated with the cutaneous blood flow decrease.ConclusionLipid peroxidation is increased in SSc patients, but not in patients with primary RP. Cold exposure leads to a significant but small increase in 15‐F2t‐IsoP levels that is independent of the cutaneous blood flow decrease. F2‐isoprostane quantification may be an interesting pharmacologic tool for monitoring responses to antioxidant treatment in SSc patients.