bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinical features and neuropathology of autosomal dominant spinocerebellar ataxia (SCA17)
Authors: Rolfs Arndt , Koeppen Arnulf H. , Bauer Ingrid , Bauer Peter , Buhlmann Sven , Topka Helge , Schöls Ludger , Riess Olaf 
Published: September 2003

AbstractAutosomal dominant spinocerebellar ataxias (SCAs) are a group of neurodegenerative disorders clinically characterized by late‐onset ataxia and variable other manifestations. Genetically and clinically, SCA is highly heterogeneous. Recently, CAG repeat expansions in the gene encoding TATA‐binding protein (TBP) have been found in a new form of SCA, which has been designated SCA17. To estimate the frequency of SCA17 among white SCA patients and to define the phenotypic variability, we determined the frequency of SCA17 in a large sample of 1,318 SCA patients. In total, 15 patients in four autosomal dominant SCA families had CAG/CAA repeat expansions in the TBP gene ranging from 45 to 54 repeats. The clinical features of our SCA17 patients differ from other SCA types by manifesting with psychiatric abnormalities and dementia. The neuropathology of SCA17 can be classified as a “pure cerebellar” or “cerebello‐olivary” form of ataxia. However, intranuclear neuronal inclusion bodies with immunoreactivity to anti‐TBP and antipolyglutamine were much more widely distributed throughout the brain gray matter than in other SCAs. Based on clinical and genetic data, we conclude that SCA17 is rare among white SCA patients. SCA17 should be considered in sporadic and familial cases of ataxia with accompanying psychiatric symptoms and dementia.
Monocyte chemoattractant protein–1 increases microglial infiltration and aggressiveness of gliomas
Authors: Platten Michael , Kretz Alexandra , Naumann Ulrike , Aulwurm Steffen , Egashira Kensuke , Isenmann Stefan , Weller Michael 
Published: September 2003

AbstractMacrophages are thought to represent a first line of defense in anti‐tumor immunity. Despite infiltration by microglial cells, however, malignant gliomas are still highly aggressive tumors. We here identify monocyte chemoattractant protein‐1 (MCP‐1) as a critical chemoattractant for glioma‐infiltrating microglial cells. MCP‐1–transfected rat CNS‐1 gliomas were massively infiltrated by microglial cells. Whereas MCP‐1 did not promote the growth of CNS‐1 cells in vitro, intracerebral CNS‐1–transfected tumors grew more aggressively than control‐transfected tumors. This provides the first functional evidence that MCP‐1 recruits microglial cells to gliomas and promotes their growth in vivo. Microglial cells may support rather than suppress glioma growth.
Caspase activation in the limbic cortex of subjects with early Alzheimer's disease
Authors: Gastard Myriam C. , Troncoso Juan C. , Koliatsos Vassilis E. 
Published: September 2003

AbstractWe investigated the cleavage of caspase‐3, a marker of apoptosis, in the medial temporal lobe of older subjects with minimal cognitive deficits and low CERAD/intermediate Braak scores, that is, clinicopathological descriptors of early Alzheimer's disease (AD). The activation of caspase‐3 was studied with immunoprecipitation–mass spectroscopy and immunocytochemistry, including colocalization with paired helical filaments in the neuropil and perikarya. We found that caspase‐3 is activated in the parahippocampal gyrus in subjects with mild AD and that this event is silenced in more advanced illness. Caspase‐3 immunoreactivity has a tangle‐like appearance that coevolves with paired helical filament pathology within neurons. We propose that activation of apoptosis may occur very early in the medial temporal lobe in AD. Ann Neurol 2003;54:393–398
Disturbance of muscle fiber differentiation in congenital hypomyelinating neuropathy caused by a novel myelin protein zero mutation
Authors: Szigeti Kinga , Saifi Gulam Mustafa , Armstrong Dawna , Belmont John W. , Miller Geoffrey , Lupski James R. 
Published: September 2003

AbstractWe report a case of congenital hypomyelination associated with cranial nerve dysfunction, respiratory failure, and hypertrophic cardiomyopathy confounding the clinical picture. Molecular genetic testing showed a complex de novo myelin protein zero (MPZ) mutation consisting of a 3bp deletion of CTA from nucleotide 550 to 552 and insertion of G at nucleotide 550 that by conceptual translation results in a frameshift mutation. Muscle biopsy findings are presented that allude to the effect of abnormal innervation on early postnatal muscle differentiation.
A double‐blind controlled trial of bilateral fetal nigral transplantation in Parkinson's disease
Authors: Olanow C. Warren , Goetz Christopher G. , Kordower Jeffrey H. , Stoessl A. Jon , Sossi Vesna , Brin Mitchell F. , Shannon Kathleen M. , Nauert G. Michael , Perl Daniel P. , Godbold James , Freeman Thomas B. 
Published: September 2003

AbstractThirty‐four patients with advanced Parkinson's disease participated in a prospective 24‐month double‐blind, placebo‐controlled trial of fetal nigral transplantation. Patients were randomized to receive bilateral transplantation with one or four donors per side or a placebo procedure. The primary end point was change between baseline and final visits in motor component of the Unified Parkinson's Disease Rating Scale in the practically defined off state. There was no significant overall treatment effect (p = 0.244). Patients in the placebo and one‐donor groups deteriorated by 9.4 ± 4.25 and 3.5 ± 4.23 points, respectively, whereas those in the four‐donor group improved by 0.72 ± 4.05 points. Pairwise comparisons were not significant, although the four‐donor versus placebo groups yielded a p value of 0.096. Stratification based on disease severity showed a treatment effect in milder patients (p = 0.006). Striatal fluorodopa uptake was significantly increased after transplantation in both groups and robust survival of dopamine neurons was observed at postmortem examination. Fifty‐six percent of transplanted patients developed dyskinesia that persisted after overnight withdrawal of dopaminergic medication (“off”‐medication dyskinesia). Fetal nigral transplantation currently cannot be recommended as a therapy for PD based on these results.Ann Neurol 2003;54:403–414
Acute motor axonal neuropathy rabbit model: Immune attack on nerve root axons
Authors: Susuki Keiichiro , Nishimoto Yukihiro , Yamada Mitsunori , Baba Masayuki , Ueda Shuichi , Hirata Koichi , Yuki Nobuhiro 
Published: September 2003

AbstractMacrophages in the periaxonal space and surrounding intact myelin sheath are the most prominent pathological feature of acute motor axonal neuropathy (AMAN). We describe this characteristic in nerve roots from paralyzed rabbits immunized with bovine brain ganglioside or GM1. IgG was deposited on nerve root axons. Distal nerve conduction was preserved, and late F wave components were absent during the acute phase. Initial lesions were located mainly on nerve root axons, as in human AMAN. This study thus provides supportive evidence that the rabbits constitute a model of AMAN. Ann Neurol 2003;54:000–000
Synthesis, characterization, and catalytic activity of crosslinked poly(N‐vinyl‐2‐pyrrolidone acrylic acid) copolymer–metal complexes
Authors: Jose Jincy , John Magi , Gigimol M. G. , Mathew Beena 
Published: September 2003

AbstractThis article describes the development of a new crosslinked poly(N‐vinyl‐2‐pyrrolidone acrylic acid) copolymer for potential applications in catalase‐like activity for the decomposition of hydrogen peroxide. The copolymer, crosslinked with hexanediol diacrylate (4 mol %), was prepared by the suspension polymerization of the monomers in water. The metal‐ion complexation of copolymer‐derived sodium salts was investigated for Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), and Zn(II) ions. The metal uptake varied in the following order: Cu(II) > Cr(III) > Mn(II) > Co(II) > Fe(III) > Ni(II) > Zn(II). The polymer and metal complexes were characterized by 13C cross‐polarity/magic‐angle spinning NMR, Fourier transform infrared, ultraviolet–visible, electron paramagnetic resonance, thermogravimetry, and scanning electron microscopy analyses. The catalase‐like activities of these insoluble metal complexes were investigated for the decomposition of hydrogen peroxide. Co(II) and Cu(II) complexes were effective for the catalytic decomposition of hydrogen peroxide. The catalytic decomposition was first‐order. The effects of various parameters, such as the time, temperature, pH, amount of the catalyst, concentration of hydrogen peroxide, and recyclability of the catalyst, were examined. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 895–904, 2003
Study of hyperbranched poly(glycidol) sulfate electrolyte
Authors: Xiaohui Yang , Xiaoying Sun , Jianjun Chen , Yunhang Liu , Xinling Wang 
Published: September 2003

AbstractHyperbranched poly(glycidol) alkali sulfate (SHPG‐M) was prepared based on hyperbranched poly(glycidol). Polyurethane–hyperbranched poly(glycidol) (PU–SHPG‐M) sulfate electrolyte is a kind of single ionic or cationic conducting polymer electrolyte. Such a single ionic polymer electrolyte can obviously reduce the polarization and has little decay of direct current (DC) conductivity. SHPG‐M was characterized by Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), atomic force microscopy (AFM) and impedance analysis. The optimum conductivity is ∼3 × 10−6 S·cm−1, with 30–40% SHPG‐M in the polymer electrolyte at room temperature. The species of cation greatly effects the ionic conductivity of the polymer electrolyte; that is, σSHPG‐Li > σSHPG‐Na > σSHPG‐K, with same SHPG‐M content in the polymer electrolyte. The ionic conductivity increases with an increase of temperature, and the dependence of ionic conductivity on temperature fits the Arrhenius equation well. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1185–1190, 2003
Semi‐interpenetrating polymer networks based on polyurethane and polyvinylpyrrolidone. II. Dielectric relaxation and thermal behaviour
Authors: Karabanova L. V. , Boiteux G. , Gain O. , Seytre G. , Sergeeva L. M. , Lutsyk E. D. , Bondarenko P. A. 
Published: September 2003

AbstractSemi‐interpenetrating polymer networks (semi‐IPNs) based on crosslinked polyurethane (PU) and linear polyvinylpyrrolidone (PVP) were synthezised, and their thermal and dynamic mechanical properties and dielectric relaxation behavior were studied to provide insight into their structure, especially according to their composition. The differential scanning calorimetry results showed the glass transitions of the pure components: one glass‐transition temperature (Tg) for PU and two transitions for PVP. Such glass transitions were also present in the semi‐IPNs, whatever their composition. The viscoelastic properties of the semi‐IPNs reflected their thermal behavior; it was shown that the semi‐IPNs presented three distinct dynamic mechanical relaxations related to these three Tg values. Although the temperature position of the PU maximum tan δ of the α‐relaxation was invariable, on the contrary the situation for the two maxima observed for PVP was more complex. Only the maximum of the highest temperature relaxation was shifted to lower temperatures with decreasing PVP content in the semi‐IPNs. In this study, we investigated the molecular mobility of the IPNs by means of dielectric relaxation spectroscopy; six relaxation processes were observed and indexed according the increase in the temperature range: the secondary β‐relaxations related to PU and PVP chains, an α‐relaxation due to the glass–rubber transition of the PU component, two α‐relaxations associated to the glass–rubber transitions of the PVP material, and an ionic conductivity relaxation due to the space charge polarization of PU. The temperature position of the α‐relaxation of PU was invariable in semi‐IPNs, as observed dynamic mechanical analysis measurements. However, the upper α‐relaxation process of PVP shifted to higher temperatures with increasing PVP content in the semi‐IPNs. We concluded that the investigated semi‐IPNs were two‐phase systems with incomplete phase separation and that the content of PVP in the IPNs governed the structure and corresponding properties of such systems through physical interactions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1191–1201, 2003
Polymer‐immobilized N,N′‐bis(acetylacetone)ethylenediamine cobalt(II) Schiff base complex and its catalytic activity in comparison with that of its homogenized analogue
Authors: Gupta K. C. , Abdulkadir H. K. , Chand S. 
Published: September 2003

AbstractFor the preparation of a heterogenized N,N′‐bis(acetylacetone)ethylenediamine cobalt(II) Schiff base complex, first crosslinked polymer beads were prepared by the suspension copolymerization of styrene (48.97 mmol, 5.1 g), allyl chloride (48.97 mmol, 3.746 g), and divinyl benzene (DVB; 1.75 mmol, 0.228 g) in the presence of azobisisobutyronitrile (0.9 × 10−3 mmol, 0.15 g) as an initiator at 23 ± 0.1°C under an inert atmosphere. The copolymerization of styrene, allyl chloride in the presence of gelatin (0.75 g), bentonite (2.0 g), and boric acid (2.5 g) produced beads of different crosslinked densities corresponding to the concentration of DVB in the reaction mixture. The amount of allyl chloride in the prepared beads varied from 5.40 to 7.40 mmol g−1 of beads with the amount of DVB varying from 2.0 to 0.8 mmol in the reaction mixture. A quadridentate Schiff base (acen) was prepared with ethylenediamine (5.0 mmol, 0.3 g) and acetylacetone (10.0 mmol, 1.0 g), and it was used to obtain a homogenized and heterogenized Co(II)(acen)2 complex. The extent and arrangement of the Schiff base (acen) in the crosslinked beads depended on the availability of DVB in the reaction mixture. The amount of DVB in the reaction mixture influenced the extent of cobalt(II) ion loading, the degree of swelling, the porosity, and the pore size in the prepared beads. The beads (type IV) prepared with 1.75 mmol (0.228 g) of DVB in the reaction mixture showed a degree of swelling of 9.65% and efficiencies of loading and complexation for cobalt(II) ions of 49.4 and 85%, respectively, in comparison with beads obtained at other concentrations of DVB in the reaction mixture. The structure of free and polymer‐supported Co(II)(acen)2 complexes was verified with IR, UV, and magnetic measurements, which suggested a square planar geometry for the complexes under both conditions. The catalytic activities of the homogenized and heterogenized Co(II)(acen)2 complexes were compared by the evaluation of the rate constant (k) for the decomposition of hydrogen peroxide. The heterogenized Co(II)(acen)2 complex showed a high catalytic activity for the decomposition of hydrogen peroxide (k = 2.02 × 10−4 s−1) in comparison with the homogenized Co(II)(acen)2 complex (k = 4.32 × 10−6 s−1). The energy of activation for the decomposition of hydrogen peroxide with the heterogenized Co(II)(acen)2 complex was low (38.52 kJ mol−1) in comparison with that for the homogenized complex (73.44 kJ mol−1). In both cases, the rate of decomposition of hydrogen peroxide was directly proportional to the concentration of hydrogen peroxide and cobalt(II) ions. On the basis of experimental observations, a rate expression for the decomposition of hydrogen peroxide was derived. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1398–1411, 2003
The physical reasons for the homogeneous and nonhomogeneous reactions of haloid‐containing epoxy polymer curing
Authors: Kozlov G. V. , Bejev A. A. , Zaikov G. E. 
Published: September 2003

AbstractThe homogeneous reaction of crosslinked polymer curing proceeded in the medium with small density fluctuations, and the nonhomogeneous one proceeded in the medium with large density fluctuations. A nonhomogeneous curing reaction was simulated as proceeding in a fractal space. In this case, its rate was sharply reduced in comparison with a similar reaction in a Euclidean space. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1202–1205, 2003
Characterization of the weak link of wool fibers
Authors: Yu Weidong , Postle Ron , Yan Haojing 
Published: September 2003

AbstractThe variance of fiber morphology along a fiber and the natural and artificial flaws in the fiber structure represent the primary reasons for the weak link of fibers. Accordingly, the fiber weak link can be divided into two types, that is, the geometrical thinnest part and the structural weak point. Scanning electron microscopic observation was used to characterize the morphological features of the fiber weak points whose forms are the normal thin sections, natural flaws, and artificial damage. Both the fiber profile morphology and the tensile behavior of wool fibers have been measured using a single‐fiber analyzer (SIFAN) and an optical microscope with a CCD camera plus an XQ‐1 fiber tensile tester (OM + XQ). The results from the SIFAN and OM+XQ methods indicate that the fibers breaking at their minimum diameters represent only one part of the broken fibers. The percentage of this kind of breakage is in the range of 40–60%. A new approach is presented to identify the weak‐point breakage relying on the fiber tensile behavior. The experimental results show that the probabilities of weak‐point, normal, and thinnest‐part breakage evaluated by these methods approximate 40, 60, and slightly more than 80%, respectively. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1206–1212, 2003
Observation of morphology in EPDM/nylon copolymer thermoplastic vulcanizates by atomic force microscopy
Authors: Huang Hua , Ikehara Takayuki , Nishi Toshio 
Published: September 2003

AbstractA thermoplastic vulcanizate (TPV) of an ethylene propylene diene terpolymer (EPDM) and nylon copolymer (PA) was prepared. Maleic anhydride‐grafted EPDM (EPDM‐g‐MAH) and MAH‐grafted EPR (EPR‐g‐MAH) were used as compatibilizers and sulfur was used as a curative. The phase morphology of EPDM/PA TPVs was investigated by atomic force microscopy (AFM). AFM images showed that, although there was a compatibilization reaction between EPDM‐g‐MAH and PA, phase inversion always existed for EPDM/EPDM‐g‐MAH/PA TPVs and the rubber phase could be finely dispersed in the PA matrix with an increasing compatibilizer content. For TPVs using EPR‐g‐MAH as a compatibilizer, three phases existed because of noncrosslinkability of EPR by sulfur. Crosslinked EPDM particles dispersed in a comatrix of PA and EPR‐g‐MAH could be observed by increasing the content of EPR‐g‐MAH to 26 wt %. For an EPR‐g‐MAH content of 26 wt %, the uncrosslinked EPR‐g‐MAH existing in the interface between crosslinked EPDM and PA tended to coalesce and thus resulted in a morphology of large rubber regions composed of small crosslinked particles. When the dosage of EPR‐g‐MAH was 52 wt %, the phase morphology of the blends changed to being one of PA and crosslinked EPDM particles dispersed in the MAH‐g‐EPR matrix. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1242–1248, 2003
Nonequilibrium particle morphology development in seeded emulsion polymerization. II. Influence of seed polymer Tg
Authors: Karlsson Lina E. , Karlsson Ola J. , Sundberg Donald C. 
Published: September 2003

AbstractMost structured latex particles are formed in the nonequilibrium state as a result of the reaction kinetics proceeding faster than the phase separation kinetics. Of the many factors controlling such morphologies, the polarity and glass transition temperature (Tg) of the seed polymer are important. In order to study the direct effect of the seed polymer Tg on morphology, we produced a series of poly(methyl methacrylate)/poly(methyl acrylate) seed copolymers having glass points between 52 and 98°C, and particle sizes between 320 and 390 nm. We then used styrene as a second‐stage monomer reacting in both the batch and semibatch process modes, and utilized reaction temperatures (Tr) between 50 and 70°C. Monomer feed rates were varied between flooded and starve‐fed conditions. The equilibrium morphology for these composite particles is an inverted core–shell structure, but all morphologies obtained in our experiments were nonequilibrium. Under monomer starved conditions only core–shell structures were formed when (Tr−Tg) < 0, but significant penetration of the polystyrene into the acrylic core occurs when (Tr−Tg) > 15°C. These results are reasonably well predicted using the “fractional penetration” model developed earlier. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 905–915, 2003
Electrochemical preparation of polythiophene in acetonitrile solution with boron fluoride–ethyl ether as the electrolyte
Authors: Li Xiaohong , Li Yongfang 
Published: September 2003

AbstractPolythiophene (PTh) films were prepared by the electrochemical polymerization of thiophene in acetonitrile solution with boron fluoride–ethyl ether (BFEE) as the electrolyte. The electropolymerization processes were investigated by cyclic voltammetry. The onset potential of the electropolymerization decreased dramatically with increasing BFEE proportion in the solution. The free‐standing PTh films obtained were characterized by Founier transform infrared spectroscopy, scanning electron microscopy, and X‐ray photoelectron microscopy. The influence of BFEE on the morphology and conductivity of the PTh films was also examined. The binary solvent solution consisted of acetonitrile (10 vol %) and BFEE (90 vol %), which turned out to be the optimal electrosythesis system, in which a current density of 1 mA/cm2 and a monomer concentration of 50 mM were the optimal conditions for electropolymerization. The PTh film obtained under the optimized conditions had a high tensile strength of 60 MPa and a high conductivity of 153 S/cm. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 940–946, 2003
Comparison of the toughening mechanisms of poly(vinyl chloride)/chlorinated polyethylene and poly(vinyl chloride)/acrylonitrile–butadiene–styrene copolymer blends
Authors: Zhou Liling , Wang Xin , Lin Yusheng , Yang Jingyi , Wu Qiye 
Published: September 2003

AbstractIn this study, the influence of chlorinated polyethylene (CPE) and acrylonitrile–butadiene–styrene copolymer (ABS) on the mechanical properties of poly(vinyl chloride) (PVC)/CPE and PVC/ABS hybrids were examined. The experimental results show that the toughness of the hybrids could be modified greatly by the introduction of CPE or ABS. The microstructure and impact surfaces of the blends were investigated by scanning electron microscopy and transmission electron microscopy. ABS dispersed in the form of particles or agglomerates in the PVC matrix, and CPE tended to disperse as a net structure. In the tensile test, ABS initiated crazes as stress concentrators to toughen the PVC matrix, whereas CPE, with the PVC matrix together, caused a yield deformation by shear stress to form a shear band. The formation of crazes and shear bands benefited the toughening of PVC, but to the different extent. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 916–924, 2003