bluuebunny/crossref_metadata_2025 huggingface dataset:
Brain magnetic resonance imaging in 23 patients with mucopolysaccharidoses and the effect of bone marrow transplantation
Authors: Seto Toshiyuki , Kono Kinuko , Morimoto Kyoko , Inoue Yuichi , Shintaku Haruo , Hattori Hideji , Matsuoka Osamu , Yamano Tsunekazu , Tanaka Akemi
Published: August 2002

A longitudinal study of cranial magnetic resonance imaging (MRI) was carried out in 23 patients with mucopolysaccharidoses (MPS); 1 each of types IH, VI, and VII; 2 of type IS; 10 of type II; and 4 each of types IIIB and IVA. Six types of distinct abnormalities were 1) cribriform changes or spotty changes in the corpus callosum, basal ganglia, and white matter; 2) high‐intensity signal in the white matter on T2‐weighted image; 3) ventriculomegaly; 4) diffuse cerebral cortical atrophy; 5) spinal cord compression; and 6) megacisterna magna. The cribriform changes that corresponded to dilated perivascular spaces were found in the patients with MPS IS, II, and VI. The patchy and diffuse intensity changes were found in the patient with MPS II and IIIB, respectively. MPS IH and the severe type of MPS II showed marked ventriculomegaly. Marked cerebral atrophy was observed in all MPS IIIB patients and in the severe type of MPS II patients. Spinal cord compression was a feature usually observed in MPS IH, IVA, VI, and VII. Megacisterna magna was frequent in the patients with MPS II (6/10). In 2 of 5 patients, the therapeutic effect of bone marrow transplantation (BMT) was remarkable. Both the cribriform changes and the intensity change of the white matter in a MPS VI patient disappeared 8 years after the BMT. Slight improvement of cribriform change was noted in 1 patient with MPS II 3 years after the BMT. MRS was not sufficient to estimate the accumulation of glycosaminoglycans but was useful for evaluating neuronal damages.
Lewy bodies and parkinsonism in families with parkin mutations
Authors: Farrer Matt , Chan Piu , Chen Rong , Tan Louis , Lincoln Sarah , Hernandez Dena , Forno Lysia , Gwinn‐Hardy Katrina , Petrucelli Leonard , Hussey Jennifer , Singleton Andrew , Tanner Caroline , Hardy John , Langston J. William
Published: August 2002

Previous work has established that compound mutations and homozygous loss of function of the parkin gene cause early‐onset, autosomal recessive parkinsonism. Classically, this disease has been associated with loss of dopaminergic neurons in the substantia nigra pars compacta and locus ceruleus, without Lewy body pathology. We have sequenced the parkin gene of 38 patients with early‐onset Parkinson's disease (<41 years). Two probands with mutations were followed up. Clinical evaluation of their families was performed, blinded to both genetic and pathological findings. Chromosome 6q25.2‐27 haplotype analysis was carried out independently of the trait; parkin gene expression was examined at both the RNA and protein levels. Haplotype analysis of these families revealed a common chromosome 6, with a novel 40 bp exon 3 deletion that cosegregated with disease. In the proband of the smaller kindred, an exon 7 R275W substitution was identified in addition to the exon 3 deletion; RNA analysis demonstrated that the mutations were on alternate transcripts. However, Lewy body pathology typical of idiopathic Parkinson's disease was found at autopsy in the proband from the smaller kindred. These data suggest that compound heterozygous parkin mutations and loss of parkin protein may lead to early‐onset parkinsonism with Lewy body pathology, while a hemizygous mutation may confer increased susceptibility to typical Parkinson's disease.
Syndiotactic polymerization of styrene in the presence of CpTiCl2(OC6H4X)/MAO catalytic systems
Authors: Skupiński W. , Niciński K.
Published: August 2002

CpTiCl2(OC6H4X‐p) complexes (where X =­CH3, Cl, NO2,; Cp = cyclopentadienyl) activated with methylaluminoxane (MAO) were used in syndiotactic polymerization of styrene. High activity and selectivity for all catalysts were found. The styrene conversion and reaction selectivity depend on the catalyst ageing time and temperature, polymerization temperature and the nature of the substituent in the phenoxy ring. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis and characterization of bis(indenyl) zirconium aryloxide derivatives and their use in α‐olefin polymerization
Authors: Zanella Pierino , Mascellani Nicoletta , Cason Alessandro , Garon Simona , Rossetto Gilberto , Carta Giovanni
Published: August 2002

A series of new bis(indenyl) zirconium diaryloxides of general formula Ind2Zr(OL)2 (L = C6H5, 2; C6F5, 3; 2,6‐Me2C6H3, 4; 2,4,6‐Me3C6H2, 5; 4‐tBuC6H4, 6) were synthesized by a metathesis reaction of Ind2ZrCl2 (1) with the appropriate thallium aryloxide salt, TlOL. The complexes 1–6 were characterized by 1H and 13C NMR techniques. They were also examined as catalysts for ethene and 1‐hexene polymerization with methylalumoxane as co‐catalyst, and a trend of the polymerization activity as a function of aryloxide ligands was observed. An interpretation of this trend, considering both the electronic and steric effects of the substituents on the aryloxide rings, was proposed. Copyright © 2001 John Wiley & Sons, Ltd.
Factors influencing the electroreductive polymerization of di‐n‐hexyldichlorosilane
Authors: Martins L. , Aeiyach S. , Jouini M. , Lacaze P. C. , Satgé J. , Martins J. P.
Published: August 2002

This paper reports the study of the effects of solvent, support electrolyte and the nature of the electrodes on the electroreduction of di‐n‐hexyldichlorosilane. The work performed involved the use of different types of sacrificial anode (magnesium, aluminium and zinc) and cathode (magnesium, aluminium, zinc, stainless steel, nickel, carbon and palladium) in tetrahydrofuran containing lithium perchlorate (LiClO4). Monomodal poly(di‐n‐hexyldichlorosilane) was obtained with Al/Al and Mg/Mg electrode pairs, but the polymer yield was about ten times higher with Al/Al (11%) than with Mg/Mg (1%). From the solvents and co‐solvents used (tetrahydrofuran, hexamethylphosphorotriamide, acetone, hexane, toluene, 1,1,3,3‐tetramethylurea, tris(3,6‐dioxaheptyl)amine, 1,2‐dimethoxyethane, N,N‐dimethylacetamide and dimethylformamide) with LiClO4, only the system tetrahydrofuran + hexamethylphosphorotriamide, tetrahydrofuran + N,N‐dimethylacetamide and tetrahydrofuran + toluene have given monomodal poly(di‐n‐hexyldichlorosilane) using an aluminium anode and stainless‐steel cathode. Copyright © 2001 John Wiley & Sons, Ltd.
Zinc organic compounds of some oximes coordinated with nickel(II), palladium(II) and copper(II) ions
Authors: Voiculescu Nicolae
Published: August 2002

Coordinated oximes with nickel(II), palladium(II) and copper(II) ions proved capable of giving substitution reactions with a series of zinc organic compounds. Studies have revealed that, in the cases of dimethylglyoxime and salicylaldoxime, the reaction products result from substitution of the OH···O hydrogen bridges existing in such compounds by OZnO bridges. All compounds reported in this paper were separated as colored powders and characterized by elemental analyses, IR spectroscopy, X‐ray diffraction and magnetic measurements. The new zinc organic compounds form amine adducts. Among the amine adducts, only those with pyridine were isolated and characterized. Copyright © 2001 John Wiley & Sons, Ltd.
Rhodium(I) carbonyl complexes of ether‐phosphine ligands and their reactivity
Authors: Das Pankaj , Sharma Manab , Kumari Nandini , Konwar Dilip , Dutta Dipak Kumar
Published: August 2002

The reactions of dimeric complex [Rh(CO)2Cl]2 with hemilabile ether‐phosphine ligands Ph2P(CH2)
nOR [n = 1, R = CH3 (a); n = 2, R = C2H5 (b)] yield cis‐[Rh(CO)2Cl(P ∼ O)] (1) [P ∼ O = η
1‐(P) coordinated]. Halide abstraction reactions of 1 with AgClO4 produce cis‐[Rh(CO)2(P ∩ O)]ClO4 (2) [P ∩ O = η
2‐(P,O)chelated]. Oxidative addition reactions of 1 with CH3I and I2 give rhodium(III) complexes [Rh(CO)(COCH3)ClI(P ∩ O)] (3) and [Rh(CO)ClI2(P ∩ O)] (4) respectively. The complexes have been characterized by elemental analyses, IR, 1H, 13C and 31P NMR spectroscopy. The catalytic activity of 1 for carbonylation of methanol is higher than that of the well‐known [Rh(CO)2I2]− species. Copyright © 2002 John Wiley & Sons, Ltd.
Comparative study on structural features of α chitin from Xiphopenaeus kroyeri and its precipitated product from phosphoric acid solution
Authors: Andrade C. T. , Silva K. M. P. , Tavares M. I. , Simão R. A. , Achete C. , Pérez C. A.
Published: August 2002

A sample of α chitin was obtained from shells of the shrimp Xiphopenaeus kroyeri by demineralization and deproteinization processes. This sample of native α chitin (NC) was dissolved in concentrated phosphoric acid and recovered by precipitation in an alkaline aqueous solution, giving rise to a sample named PC. Solid‐state carbon‐13 nuclear magnetic resonance (13C‐NMR), X‐ray diffraction, and atomic force microscopy (AFM) techniques were used to compare both samples and to investigate structural changes in α chitin under the action of phosphoric acid. 13C‐NMR experiments and X‐ray diffraction results revealed a high crystalline order in both samples. Structural differences were due to the higher distance between adjacent chains along the b axis and the consequent decrease in the number of intermolecular hydrogen bonds in the sample recovered from solution. While remarkable supramolecular differences could be observed in the fibrillar crystals of the NC sample, the PC sample was characterized by only one type of morphology. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 151–159, 2002
Electrochemistry of polyaniline: Study of the pH effect and electrochromism
Authors: Prakash Rajiv
Published: August 2002

Polyaniline was electrochemically synthesized from an aqueous medium with various acid electrolytes via potentiodynamic and potentiostatic techniques. The electrochemical synthesis of polyaniline was studied over various substrates, including Pt, Ti, Ni, and SnO2 coated glass, and in various acid electrolytes. Cyclic voltammograms of electrochemically synthesized polyaniline were studied in HCl in a pH range of 1–4. Probable electrochemistry and chemical changes were deduced that occurred when polyaniline film was electrochemically oxidized and reduced between −0.2 and 1.0 V versus a Ag/AgCl reference electrode in an acidic electrolyte at pH 1, and three corresponding oxidation and reduction peaks were described instead of two redox peaks (as observed by W. S. Huang, B. D. Humphrey, and A. G. MacDiarmid, J Chem Soc Faraday Trans 1 1986, 82, 2385). The electrochromic property was studied with changes in the chemical states of polyaniline during electrochemical oxidation and reduction. A new viscous electrolyte, aqueous AlCl3 (pH 2), saturated with AgCl was used for the construction of an electrochromic display device. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 378–385, 2002
Synthesis and properties of TLCPs with 2,6‐naphthalene‐based mesogen, polymethylene spacer, and nonlinear 4,4′‐thiodiphenyl links
Authors: Chang Hao‐Shiung , Wu Tzi‐Yi , Chen Yun
Published: August 2002

A series of new thermotropic main‐chain liquid crystalline copolyesters were prepared by polycondensation of 2,6‐naphthalenedicarbonyl chloride, 4,4′‐thiodiphenol, and α,ω‐alkanediols (n = 4–10) in diphenyl ether at 200°C. Thermal transition behaviors of these copolyesters were investigated by differential scanning calorimetry. Moreover, their thermal stabilities and mesomorphic textures were studied by thermogravimetric analysis and polarizing optical microscopy, respectively. Corresponding model compounds with terminal mesogenic units and central polymethylene spacers were also synthesized for comparison. Both copolymers and model compounds exhibit odd–even dependency of melting temperatures, transition enthalpy (ΔHm), and entropy (ΔSm) on the number of methylene units in the spacer. However, the odd–even effects in model compounds are much more distinctive. Nematic mesophases are the only texture observed in melts, except the model compounds with longer methylene units (n = 8, 10), in which smectic mesophases can be observed. The Tm values of the copolyesters (TDP/HD = 1/1) are between 233 and 259°C, depending on spacer length. The initial decomposition temperatures of the copolyesters are above 419°C under N2 atmosphere. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1536–1546, 2002
Diethyl ketone‐based imine as efficient latent hardener for epoxy resin
Authors: Suzuki Kentarou , Matsu‐Ura Nobuki , Horii Hisakazu , Sugita Yuko , Sanda Fumio , Endo Takeshi
Published: August 2002

Several imines were synthesized and evaluated as water‐initiated hardener for epoxy resin. Imines with a lower electron density on the C=N carbon showed a faster hydrolysis rate. Diethyl ketone‐based imines were the most efficiently hydrolyzed among the imines examined, and the adhesive properties of epoxy resin with diimines used as the hardeners were evaluated. A novel diethyl ketone‐based diimine, N,N′‐di(1‐ethylpropylidene)‐m‐xylylenediamine (10), served as an efficient latent hardener of epoxy resin. Epikote 828 containing 10, filler, and dryer increased the adhesive strength faster than Epikote 828 containing filler and dryer with methyl isobutyl ketone‐based imine. The mixed system of epoxy resin and 10 showed good storage stability at room temperature. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1744–1749, 2002
Prediction and experiment of core–shell particle morphology of vinyl acetate and butyl acrylate
Authors: Sun Peiqin , Zhao Ke , Liu Dazhuang , Huo Dongxia
Published: August 2002

In this article, the particle morphology in emulsion polymerization of the poly(vinyl acetate) (PVAc)/poly(butyl acrylate) (PBA) system is investigated. With the use of the basic data in literature, the relevant interface tensions and viscosity are estimated with the equation proposed in literature. The time achieved to equilibrium morphology is predicted with cluster dynamics proposed by Gonzalez. The experiment result is consistent with that of prediction. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2930–2937, 2002; DOI 10.1002/app.10297
Carbonaceous materials prepared from carbon tetrachloride and dimethyl sulfoxide
Authors: Wang Fan , Shi Gaoquan , Xu Zhengjiang , Zhang Jiaxin , Chen Fengen , Hong Xiaoyin
Published: August 2002

A novel liquid/solid two‐phase reaction has been discovered that enables destruction of carbon tetrachloride (CCl4) to a black carbon‐based material. The solid phase is potassium hydroxide, and the liquid phase is a dimethyl sulfoxide (DMSO) solution of carbon tetrachloride and contains a certain amount of tetrabutylammonium bromide (TBAB) as the phase‐transfer catalyst. The reaction can be carried out at room temperature and under normal pressure. Pyrolysis of the carbon‐based materials at 700°C and under a nitrogen atmosphere resulted in the formation of amorphous carbonaceous nanoparticles with diameters in the range of 30–60 nm. The carbonaceous materials have a specific surface area of 430 m2/g and an average pore size of 16 Å. Raman spectral and elemental analysis results show the carbonaceous material consists of sp3 and sp2 carbons and also contains a small amount of hydrogen (H/C = 0.08). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 785–791, 2002
Effect of comonomers on melt processability of polyacrylonitrile
Authors: Rangarajan P. , Yang J. , Bhanu V. , Godshall D. , McGrath J. , Wilkes G. , Baird D.
Published: August 2002

This work is concerned with the feasibility of achieving melt‐processable polyacrylonitrile copolymer systems as precursors for the manufacture of carbon fibers. Identification of suitable comonomers and achieving the optimum content of the comonomer were some of the main objectives of this investigation. It was seen that methyl acrylate (MA) was found to be suitable for enabling the melt processing of polyacrylonitrile (PAN), in terms of melt viscosity, time stability, and char yield. Below 10 mol % of MA, the PAN copolymer exhibited no flowability, even at very low molecular weights (∼ 20,000). The long‐range order inherently present in PAN is speculated to be broken down at a critical value of about 10% MA at 220°C in the PAN‐based system, enabling its melt flowability. It was also seen that the incorporation of MA was seen to improve the temperature and molecular weight window of processability of the PAN system. The molecular weight cutoff for the 90/10 mol % acrylonitrile/methyl acrylate (AN/MA) system was about 50,000 at 220°C, whereas it was increased to about 100,000 in the presence of 15 mol % MA comonomer. Feasibility studies on the use of other comonomers such as higher acrylates and acrylamides were also conducted. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 69–83, 2002
Blends of i‐PP and SBS. I. Influence of the in situ compatibilization on the morphology
Authors: Wilhelm Helena Maria , Felisberti Maria Isabel
Published: August 2002

This article concerns the in situ compatibilization of immiscible isotactic polypropylene/butadiene‐styrene‐butadiene triblock copolymer blends (i‐PP/SBS) by means of a reactive mixture. For this purpose, maleated PP (PP‐MAH) and SBS (SBS‐MAH) were used as functionalized polymers and 4,4′‐diaminediphenylmethane was used as a coupling agent between maleated polymers, resulting in a graft copolymer. Binary blends i‐PP/SBS, nonreactive ternary blends i‐PP/PP‐MAH/SBS, and reactive ternary blends i‐PP/PP‐MAH/SBS‐MAH with varying diamine and anhydride molar ratios were prepared. Torque measurements suggest a graft copolymerization during the melt blending for ternary reactive blends, but the extension of the grafting does not vary with the diamine and anhydride molar ratio, but with the elastomer concentration. The morphology of the blends was investigated by scanning electron microscopy. The morphology of binary and ternary nonreactive blends is similar, exhibiting elastomer domains disperse in the i‐PP matrix, whose sizes increase with elastomer concentration. On the other hand, the elastomer domain size in the ternary reactive blends is practically independent of the blends composition and of the diamine and anhydride molar ratio. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 847–855, 2002
Recoverable shear strain of liquid crystal‐forming concentrated hydroxypropyl cellulose solutions
Authors: Suto Shinichi , Mitamura Junya , Sasaki Yasuyuki
Published: August 2002

The recoverable shear strain (SR) for the liquid crystal‐forming hydroxypropyl cellulose solutions was determined by means of a concentric cylinder rotational apparatus as functions of shear stress prior to recovery and concentration of the solutions at 30°C. SR greatly depended on shear stress and concentration; the phase of the solution (the single phase or biphase) governed the dependences of SR on stress and concentration. SR increased with increasing stress for the single phase and decreased for the biphase. SR seemed to be related to the die swell (B): SR ∝ Bn. SR exhibited a maximum and a minimum with respect to concentration. SR for the cellulosic cholesteric liquid crystalline solutions was greater than that for the isotropic solutions. A model was proposed for explaining the greater SR. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 865–872, 2002
Syntheses and characterization of poly(butylene terephthalate) copolyesters modified with p‐acetoxybenzoic acid
Authors: Kang Tae‐Kyu , Kim Yang , Cho Won‐Jei , Ha Chang‐Sik
Published: August 2002

Poly(butylene terephthalate) (PBT) copolyesters modified with seven compositions of p‐acetoxybenzoic acid (PABA) ranging from 10 to 70 mol % were prepared. The X‐ray diffraction patterns, the polarizing microscopy behaviors, and thermal analysis showed that the modified PBT contained more PABA homopolymer units (PABA–PABA) than PBT–PABA units in the copolyesters. On increasing PABA mole percenage, PBT crystallinity decreased and thermal stability increased. It was found that although the PBT copolyesters did not exhibit a clear liquid crystalline texture like the copolyester of poly(ethylene terephthalate) modified with PABA did, the PBT copolyester containing 70 mol % of PABA exhibited the typical shear thinning behavior of a liquid crystalline polymer. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1085–1095, 2001
Synthesis of new polyureas derived from 4‐cyclohexylurazole
Authors: Mallakpour Shadpour E. , Rostamizadeh Hossein
Published: August 2002

4‐Cyclohexylurazole (1) R = cyclohexyl (CHU) was prepared from cyclohexyl isocyanate in two steps. Polycondensation reactions of compound CHU with hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), and toluene‐2,4‐diisocyanate (TDI) were performed in DMAc/chloroform and DMAC in the presence of pyridine as a catalyst. The resulting novel polyureas have an inherent viscosity in the range of 0.044–0.206 g/dL in DMF at 25°C. These polyureas were characterized by IR, 1H–NMR, elemental analysis, and TGA. The resulting polymers are soluble in most organic solvents. Some physical properties and structural characterization of these novel polyureas are reported. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1335–1341, 2001
Conducting composite film based on polypyrrole and crosslinked cellulose
Authors: Yin Wusheng , Li Jun , Li Yongming , Wu Jingpin , Gu Tiren
Published: August 2002

Polypyrrole/crosslinked cellulose conductive composite films were prepared by vapor‐phase polymerization of pyrrole on the silicon crosslinked cellulose network using anhydrous ferric chloride as oxidant. The properties of the composite film depend on their synthetic conditions such as the amount of ferric chloride and tetraethyl orthosilicate crosslinker, the reaction time, the solvent, etc. Interestingly, it was found that the conductivity was strongly affected by the nature of the solvents and their amount in pyrrole solution. When the weight ratio of methanol/pyrrole is 1 : 1, the conductivity was as high as 1.1 S/cm, increased by two orders of magnitude compared to that without solvent, and the mechanical properties was good. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1368–1373, 2001
PTC effect in carbon black‐filled ethylene–propylene–diene terpolymer systems
Authors: He Xiujuan , Wang Lijie , Chen Xinfang
Published: August 2002

The positive temperature coefficient (PTC) effects of carbon black (CB)‐filled semicrystalline and amorphous ethylene–propylene–diene terpolymer (EPDM) composites were studied. The semicrystalline EPDM/CB composite exhibited a low PTC effect followed by a pronounced negative temperature coefficient (NTC) effect, while the amorphous EPDM/CB composite exhibited only an NTC effect. By the effect of γ‐ray irradiation, not only was the NTC effect of the composites eliminated, but also a high PTC effect appeared. The PTC intensity reached as high as six orders of magnitude even for an amorphous EPDM/CB composite and the PTC transition temperature decreased with the irradiation dose. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1571–1574, 2001
Study of mechanical and rheological behaviors of linear and branched polycarbonates blends
Authors: Lyu Min‐Young , Lee Jae Sik , Pae Youlee
Published: August 2002

A study of the mechanical and rheological properties of linear and branched polycarbonates blends is presented. Phase separations of the blends were checked through DSC and SEM, and, subsequently, mechanical and rheological properties were investigated. Phase separations were not observed in the blends. The mechanical properties were examined through tensile, flexural, and impact tests. All the mechanical properties of the blends were relatively independent of the compositions. For study of the rheological properties, melt viscosity, storage and loss moduli, and melt tension of the blends with various compositions were examined at various temperatures. The dependence of the viscosity on the molecular weight was also studied. As the content of branched polycarbonate increases, the dependence of the viscosity on the molecular weight and the shear thinning behavior became more marked. Melt tensions were also increased as the branched polycarbonate content increased in the blends for all tested temperatures. In this study, the blend systems which have same mechanical properties but different rheological properties can be obtained through blending of linear and branched polycarbonates. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1814–1824, 2001
Recycling of commingled plastics waste containing polypropylene, polyethylene, and paper
Authors: Mehrabzadeh M. , Farahmand F.
Published: August 2002

Polymer waste recycling is a major technical problem, because large amounts of synthetic polymers are produced every day and polymeric wastes are gathered from municipal solid wastes. There are a few polyolefins, such as polyethylene (PE) and polypropylene (PP) with huge amounts of paper in the waste materials. In order to recycle the commingled plastics waste that contains paper, hydrolytic treatment is needed prior to conventional processing. In this project, the optimum conditions of hydrolytic treatment of paper and the mechanical properties and morphological state of different compositions of PP high‐density PE (HDPE) blends with paper were studied. Ethylene‐propylene‐diene copolymer (EPDM) was added to improve the mechanical properties of blends. The results show that the hydrolytic treatment of paper improves the mechanical properties, such as the tensile strength and modulus of the PP/HDPE/paper composites relative to the untreated samples, and up to 30% paper can be added to commingled PP and HDPE blends. The EPDM was used as an impact modifier. The plastics waste containing paper can be used in applications such as artificial wood. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2573–2577, 2001
Heating simulation of multilayer preforms
Authors: Lebaudy Ph. , Grenet J.
Published: August 2002

In the area of beverage packaging, the barrier properties (to gases, water, organic vapors/flavors) are parameters of great importance. For poly(ethylene terephtalate) (PET), largely used in bottling, the improvement of these barrier properties upon biaxial orientation is a direct result of both the level of crystallinity as well as the orientation of the material. However, even with higher crystallinity and orientation for some applications, the PET barrier properties are not adequately efficient and thus multilayer polymer materials must be used to make the bottles. During plastic‐forming processes, the semifinished multilayer thermoplastic products (such as a preform) must be heated to a rubberlike state. Experiments on PET reveal that temperatures either below or close to the glass transition (Tg) are essential to achieve principally oriented glassy structure and that the crystalline structure could be enhanced as well by thermal or high‐drawing treatments. Because of the great differences in the stretching ratio inside the preform and the thermomechanical behavior of the materials, a good stretching process requires that the material have a nonuniform temperature profile. A model is developed to calculate temperature distribution in multilayer preforms. This model is a useful tool for understanding the heating stage of thermoplastic products and is suitable to control and optimize industrial processes. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2683–2689, 2001
Plasticization of cellulose diacetate by reaction with maleic anhydride, glycerol, and citrate esters during melt processing
Authors: Lee Seung‐Hwan , Shiraishi Nobuo
Published: August 2002

To accomplish the stable internal plasticization of cellulose diacetate (CDA), maleic anhydride (MAH) and glycerol (Gly) were used as reactive plasticizers. The plasticization method used was based on a melt‐processing reaction of CDA with MAH and Gly. MAH and Gly (MG)‐plasticized CDA showed stiff and brittle properties; that is, low elongation at break and high modulus. Thus, citrate esters were used as coplasticizers to improve physical properties. The resulted plasticized materials were optically clear, and showed attractive mechanical properties. The grafting of MG oligoesters to the free hydroxyl groups in CDA and their homo‐oligomerization were accelerated by two‐step kneading process, and verified by FTIR and GPC measurements. Differential scanning calorimeter (DSC) analysis revealed decreases of 80–100°C in the glass transition temperature (Tg) of CDA by these plasticizations. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 243–250, 2001
Electron spin resonance spectroscopic studies on microheterogeneity of crosslinked polymers. IV. Correlation between void evaluation of crosslinked resin and microgelation in monomethacrylate/dimethacrylate copolymerizations
Authors: Matsumoto Akira , Nishizawa Kazuyoshi , Yamashita Yukihiko , Morita Takehiko , Aota Hiroyuki
Published: August 2002

Electron spin resonance spectroscopic studies on the microheterogeneity of crosslinked polymers were performed to ascertain the correlation of the void evaluation of monomethacrylate/dimethacrylate (DMA) cured resins with the microgel formation before gelation in their crosslinking copolymerizations. Lauryl methacrylate (LMA) was added to methyl MA (MMA)/ethylene DMA (EDMA) copolymerization because the addition of LMA reduces the occurrence of intramolecular crosslinking by the steric hindrance of bulky long‐chain alkyl groups, leading to the formation of a less densely crosslinked microgel core and a less microheterogeneously crosslinked resin. Then MMA/vinyl laurate (VL)/EDMA terpolymerization was performed because the polymerizability of conjugated methacryloyl groups belonging to MMA and EDMA is markedly high compared with the unconjugated vinyloxycarbonyl group of VL. Thus, enhanced microheterogeneity for MMA/VL/EDMA terpolymerization would be induced as compared with MMA/EDMA copolymerization. Finally, allyl MA (AMA) and vinyl MA (VMA) crosslinkers were used in place of EDMA because in the polymerizations of AMA and VMA having two types of carbon–carbon double bonds of different reactivities there was no microgelation observed up to the gel‐point conversion. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1187–1192, 2001
Surface graft copolymerization of 2‐hydroxyethyl methacrylate onto low‐density polyethylene film through corona discharge in air
Authors: Lei Jingxin , Liao Xia
Published: August 2002

The corona discharge technique was explored as a means of forming chemically active sites on a low‐density polyethylene (LDPE) film surface. The active species thus prepared at atmospheric pressure in air was exploited to subsequently induce copolymerization of 2‐hydroxyethyl methacrylate (HEMA) onto LDPE film in aqueous solution. The results showed that with the corona discharge voltage, reaction temperature, and inhibitor concentration in the reaction solution the grafting degree increased to a maximum and then decreased. As the corona discharge time, reaction time, and HEMA concentration in the reaction solution increased, the grafting degree increased. With reaction conditions of a 5 vol % HEMA concentration, 50°C copolymerization temperature, and a 2.0‐h reaction time, the degree of grafting of the LDPE film reached a high value of 158.0 μg/cm2 after treatment for 72 s with a 15‐kV voltage at 50 Hz. Some characteristic peaks of the grafted LDPE came into view at 1719 cm−1 on attenuated total reflectance IR spectra (CO in ester groups) and at 531 eV on electron spectroscopy for chemical analysis (ESCA) spectra (O1s). The C1s core level ESCA spectrum of HEMA‐grafted LDPE showed two strong peaks at ∼286.6 eV (CO from hydroxyl groups and ester groups) and ∼289.1 eV (OCO from ester groups), and the C atom ratio in the CO groups and OCO groups was 2:1. The hydrophilicity of the grafted LDPE film was remarkably improved compared to that of the ungrafted LDPE film. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2881–2887, 2001
Influence of hot‐melt extrusion and compression molding on polymer structure organization, investigated by differential scanning calorimetry
Authors: Sarraf A. G. , Tissot H. , Tissot P. , Alfonso D. , Gurny R. , Doelker E.
Published: August 2002

A blend of a pullulan polymer and 1,2,6‐hexanetriol as a plasticizer were used to study the effect of melt processing techniques on the physical properties of the resulting materials. The main advantage of pullulan is its linear polysaccharide chain model structure. Hot‐melt extrusion and compression molding were performed under the same temperature and pressure conditions. The materials obtained were analysed by differential scanning calorimetry. For the first time, the comparative effect of the two processing techniques, i.e., extrusion and compression molding, on the polymer arrangement is reported. Endothermic events resulted from the melt extrusion process were shown to be related to different structures of oriented populations of macromolecules and to microphase separation. Orientation was enhanced by cooling the extrudate at the die exit, with a corresponding increased enthalpy from 34.7 to 51.4 J/g. In contrast, when using compression molding, the endotherm was less marked (11.9 J/g), suggesting less orientation, but the shape of the thermogram was quite similar to that of the extrudate. In both cases, we observed a loss of orientation when the molded materials were milled. A semiquantitative kinetic study of the disorientation process of the extrudate upon isothermic tempering suggests that a disorientation phenomenon occurs at the same time as a swelling process due to the presence of microphase separation. The extrudate was shown to be stable at 25°C. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3124–3132, 2001
Synthesis of water‐soluble polymers containing sulfonic acid and amine moieties for the recovery of metal ions using ultrafiltration
Authors: Rivas Bernabé L. , Pooley S. Amalia , Luna Maribel , Geckeler Kurt E.
Published: August 2002

Copolymers from 2‐acrylamido‐2‐methyl‐propane sulfonic acid (APSA) and N‐acryloyl‐N‐methyl piperazine (AP) were synthesized by radical polymerization with ammonium peroxydisulfate as the initiator. The copolymerization yield ranged between 93 and 95%. The copolymers were completely water soluble, and were characterized by FTIR and NMR spectroscopy. The copolymer composition was determined from elemental analysis through the S/C ratio. The binding capacity for metal ion was studied by the LPR technique at different pH and filtration factors. The retention depended strongly on the pH and on the copolymer composition. With increasing pH and increasing content of APSA units in the copolymer, the metal ion retention increased. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 22–30, 2001
Preparation and application of chiral recognizable thermosensitive polymers and hydrogels consisting of N‐methacryloyl‐s‐phenylalanine methyl ester
Authors: Sugiyama Kazuo , Rikimaru Satoshi , Okada Yoshiharu , Shiraishi Kohei
Published: August 2002

Amphiphilic random copolymers, poly(R‐HPMA‐co‐S‐PAM) and poly(HPMA‐co‐S‐PAM), were prepared by radical copolymerization of N‐methacryloyl‐(S)‐phenylalanine methyl ester (S‐PAM) and N‐[(R)‐2‐hydroxypropyl]methacrylamide (R‐HPMA) or N‐(2‐hydroxypropyl)methacrylamide (HPMA) with various molar ratios of R‐HPMA (or HPMA) (m) to S‐PAM (n). Either aqueous solution of poly(R‐HPMA‐co‐S‐PAM) with the molar ratio of m : n = 0.81 : 0.19 or poly(HPMA‐co‐S‐PAM) with the molar ratio of m : n = 0.79 : 0.21 exhibited the lower critical solution temperature (LCST) at 16°C. The LCST in the presence of (S)‐(−)‐phenylalanine (S‐Phe) shifted from 16 to 20°C and 18°C for poly(R‐HPMA‐co‐S‐PAM) and poly(HPMA‐co‐S‐PAM), respectively, whereas the LCST did not shift in the presence of (R)‐(+)‐phenylalanine (R‐Phe). Thermosensitive Gel(R‐HPMA‐co‐S‐PAM) and Gel(HPMA‐co‐S‐PAM) were also prepared from radical copolymerization of S‐PAM and R‐HPMA or HPMA in the presence of N,N′‐ethylenebisacrylamide (EBAAm) as a crosslinker. When the gels shrunk at 40°C, the release of dansyl‐(R)‐phenylalanine (Dans‐R‐Phe) from the gel in which loaded Dans‐R‐Phe occurred was more easily done than that of Dans‐S‐Phe from the gel that loaded Dans‐S‐Phe. Thus, these thermosensitive copolymers and gels were found to exhibit chiral recognition for phenylalanine derivatives. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 228–236, 2001
Study of exchange reaction in polycarbonate‐modified polybenzoxazine via model compound
Authors: Ishida Hatsuo , Lee Yu‐Hsin
Published: August 2002

The chain fragmentation in polycarbonate (PC) and polybenzoxazine blend upon thermal polymerization is investigated by size exclusion chromatography with the aid of monofunctional benzoxazine model compound. Molecular weight reduction of PC polymer via transesterification between the hydroxyl groups of ring‐opened benzoxazine and the carbonate groups from PC was observed. In addition, excess heat of reaction compared to the expected value is detected from differential scanning calorimetry and is assigned to the exotherm associated with the exchange reaction. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1848–1855, 2002
Morphological analysis of endocytosis in efferent ductules of estrogen receptor‐α knockout male mouse
Authors: Nakai Masaaki , Bouma Jerry , Nie Rong , Zhou Qing , Carnes Kay , Dennis  , Lubahn B. , Rex  , Hess A.
Published: August 2002

Lack of estrogen receptor (ER) results in fluid accumulation and dilation of the efferent ductules, suggesting that the role of estrogen and ER in the male reproductive tract is related to fluid reabsorption in the ductules. In the present study, endocytosis of the nonciliated cells of the efferent ductules was compared morphologically between wild type (WT) and estrogen receptor‐α knockout (αERKO) male mice. The epithelial cells lining the WT efferent ductules were tall columnar in shape, whereas those of the αERKO were low columnar. Immunocytochemically, the nonciliated cells of both genotypes showed positive reactions of sulfated glycoprotein‐2, but the reaction products were reduced in amount in the αERKO. Electron microscopy revealed that the nonciliated cells of the WT had numerous organelles for endocytosis such as coated pits and vesicles, tubules, endosomes, multivesicular bodies and lysosomes in the apical cytoplasm. These organelles were less developed in the nonciliated cells of the αERKO. Morphometric analysis indicated that there was a significant reduction in area of endocytotic apparatus in the nonciliated cells of the αERKO compared with that of the WT. A tracer study using gold particles demonstrated that the nonciliated cells of both WT and αERKO efferent ductules were capable of taking up luminal contents. These results suggest that reabsorption of the luminal contents via endocytosis takes place in the efferent ductules but is greatly reduced in amount in the absence of ERα. Anat Rec 263:10–18, 2001. © 2001 Wiley‐Liss, Inc.
Testosterone mediates satellite cell activation in denervated rat levator ani muscle
Authors: Nnodim Joseph O.
Published: August 2002

Denervation stimulates quiescent satellite cells in skeletal muscle to reenter the cell cycle. In the androgen‐sensitive rat levator ani muscle (LA), this mitotic response to loss of neural input fails to occur in castrated animals. To elucidate the role of androgens in denervation‐induced satellite cell proliferation, the denervated LA of castrated rats (Group A) was compared with that of animals infixed with testosterone implants after castration (Group B). Mean myofiber cross‐sectional areas (Group A: 362.95 μm2 ± 27.74; Group B: 403.13 μm2 ± 53.87) and linear nuclear densities (Group A: 74.07 mm−1 ± 17.58; Group B: 104.13 mm−1 ± 4.06) were similar (P > 0.05) in both groups. The androgen‐deprived myofibers of Group A, however, had a significantly lower nuclear content (271.0 ± 74.91 vs. 1,285.80 ± 81.74 in Group B; P < 0.05) on account of their considerably shorter mean length (3.44 mm ± 0.29 vs. 12.31 mm ± 0.92 in Group B; P < 0.05). The proportional representation of satellite cells in hormone‐replaced, denervated muscle was more than twice that in the untreated group (Group B: 5.15 ± 0.83% vs. Group A: 2.28 ± 0.23%; P < 0.05). In absolute terms, the satellite cell number in Group B was approximately an order of magnitude greater than in Group A (408.4 × 103 vs. 38.08 × 103). The results confirm the absence of testosterone as the factor responsible for the inability of satellite cells in the LA of castrated rats to respond mitotically to the withdrawal of neural input after denervation. Anat Rec 263:19–24, 2001. © 2001 Wiley‐Liss, Inc.
Ras target protein canoe is a substrate for Cdc2 and Cdk5 kinases
Authors: Takahashi Kuniaki , Hamada Noriko , Yamamoto Daisuke
Published: August 2002

Mutations in the canoe locus of Drosophila lead to failure in the dorsal closure of the embryonic epidermis and pattern formation defects in imaginal eyes and wings. In the wing, the canoe mutants develop extra veins when they are heterozygous for shaggy, a mutation in the locus encoding the glycogen synthase kinase 3β (Gsk3β), which has been known to phosphorylate the Armadillo protein. Although Canoe has a putative target sequence for phosphorylation by Gsk3β similar to that found in Armadillo, in vitro experiments indicate that Canoe is not phosphorylated by Gsk3β. Instead, Canoe is demonstrated to be a good substrate of Cdc2 and Cdk5 kinases. Thus, Cdc2 and Cdk5 kinases are the potential regulators of the function of Canoe in morphogenesis. Arch. Insect Biochem. Physiol. 49:102–107, 2002. © 2002 Wiley‐Liss, Inc.
Characterization of cockroach (Periplaneta americana) fat body phospholipase A2 activity
Authors: Sun D. , Steele J.E.
Published: August 2002

A phospholipase has been identified in the fat body of the American cockroach, Periplaneta americana, which removes fatty acid from the sn‐2 acyl position of an artificial substrate. The enzyme has been characterized using a crude preparation obtained by low‐speed centrifugation of the homogenized tissue. With 1‐hexadecanoyl‐2‐(1‐pyrenedecanoyl)‐sn‐glycero‐3‐phosphocholine as the substrate, the Km has been estimated to be 1.17 μM and the vmax 113.5 pmol/min/mg protein. The phospholipase has a pH optimum close to 7 and shows maximal activity at 50°C. Activity of the phospholipase has been determined in cytosolic and plasma membrane fractions. The specific activity of the latter fraction is approximately twice that of the cytosol. The enzyme in both fractions is Ca2+‐independent. Arch. Insect Biochem. Physiol. 49:149–157, 2002. © 2002 Wiley‐Liss, Inc.
Uptake, flow, and digestion of casein and green fluorescent protein in the digestive system of Lygus hesperus Knight
Authors: Habibi Javad , Brandt S.L. , Coudron T.A. , Wagner R.M. , Wright M.K. , Backus E.A. , Huesing J.E.
Published: August 2002

Selected compounds were used to study physiological processes associated with digestion in the western tarnished plant bug, Lygus hesperus Knight. Durations of passage and rates of absorption, digestion, and excretion were determined for a digestible protein (casein), a non‐digestible protein (green fluorescent protein, GFP), and a non‐digestible carbohydrate (dextran). Dextran was used as a control to monitor the non‐absorptive flow rate of ingesta through the digestive system. Fluorescent tracking of FITC‐conjugates of casein and dextran, as well as immunoblotting and immunofluorescent staining of casein and GFP, were used to monitor the degradation (in vitro) and ingestion, digestion, and distribution (in vivo) of the respective compounds. Under our experimental conditions, L. hesperus took discrete meals, feeding and excreting at 2–3‐h intervals. Rate of food passage was variable. FITC‐dextran was found in the fecal material of most insects by 6–8 h after treatment initiation; by 12 h, 95% of ingested FITC‐dextran was recovered from all insects. FITC‐casein was digested extensively in in vitro homogenates of gut, hemolymph, and salivary gland. In vivo, FITC‐casein was ingested and partially absorbed as a holoprotein into the hemolymph. Ingested FITC‐casein was partially degraded in the gut and hemolymph within 2 h of ingestion, and no holoprotein was found after 12 h. In contrast, there was no detectable degradation of GFP in hemolymph, gut, and salivary gland homogenates after 24 h of incubation. Ingested GFP was not degraded in gut or hemolymph up to 8 h after treatment initiation, but did transfer to the hemolymph as a holoprotein. Analysis of immunohistological images confirmed that GFP bound to gut epithelial cell brush‐border membranes. However, the mechanism by which GFP and casein pass as holoproteins into the hemolymph remains unknown. Arch. Insect Biochem. Physiol. 50:62–74, 2002. Published 2002 Wiley‐Liss, Inc.†
The peritrophic membrane of Spodoptera frugiperda: Secretion of peritrophins and role in immobilization and recycling digestive enzymes
Authors: Bolognesi Renata , Ribeiro Alberto F. , Terra Walter R. , Ferreira Clélia
Published: August 2002

A peritrophin from the Spodoptera frugiperda peritrophic membrane (PM) and microvillar proteins from S. frugiperda anterior midgut cells were isolated and used to raise antibodies in a rabbit. These antibodies, as well as a Tenebrio molitor amylase antibody that cross‐reacts with S. frugiperda amylases, and wheat‐germ aglutinin were used in immunolocalization experiments performed with the aid of confocal fluorescence and immunogold techniques. The results showed that the peritrophin was secreted by anterior midgut columnar cells in vesicles pinched‐off the microvilli (microapocrine secretion). The resulting double membrane vesicles become single membrane vesicles by membrane fusion, releasing peritrophin and part of the amylase and trypsin. The remaining membranes still containing microvillar proteins and membrane‐bound amylase and trypsin are incorporated into a jelly‐like material associated with PM. Calcofluor‐treated larvae lacking a PM were shown to lose the decreasing gradient of trypsin and chymotrypsin observed along the midgut of control larvae. This gradient is thought to be formed by a countercurrent flux of fluid (in the space between PM and midgut cells) that powers enzyme recycling. Arch. Insect Biochem. Physiol. 47:62–75, 2001. © 2001 Wiley‐Liss, Inc.
Mass spectrometric evidence for the deficiency in the dark‐color‐inducing hormone, [His7]‐corazonin in an albino strain of Locusta migratoria as well as for its presence in solitary Schistocerca gregaria
Authors: Baggerman Geert , Clynen Elke , Mazibur Rahman , Veelaert Dirk , Breuer Michael , De Loof Arnold , Tanaka Seiji , Schoofs Liliane
Published: August 2002

A factor present in the brain and corpus cardiacum responsible for the induction of dark colour in Locusta migratoria was recently isolated and identified from the corpora cardiaca of normally pigmented locusts. The purification of this factor, designated as [His7]‐corazonin was monitored using an albino mutant from a laboratory colony of an Okinawa (Japan) strain. In this study, we provide unequivocal mass spectrometric evidence that the brain and the corpora cardiaca of this albino Locusta mutant are deficient in [His7]‐corazonin. Previously, [His7]‐corazonin was shown to be responsible for the induction of dark body colour patterns as observed in crowded locusts. Using nanoflow‐liquid chromatography‐mass spectrometry, we demonstrated that this dark colour–inducing hormone is, however, present in the corpora cardiaca of solitary locusts (Schistocerca gregaria). Arch. Insect Biochem. Physiol. 47:150–160, 2001. © 2001 Wiley‐Liss, Inc.