bluuebunny/crossref_metadata_2025_split huggingface dataset:
Age of onset and death in inherited prion disease are heritable
Authors: Webb T.E.F. , Whittaker J. , Collinge J. , Mead S. 
Published: August 2008

AbstractThe common polymorphism at codon 129 of the prion protein gene (PRNP) is known to affect prion disease susceptibility, incubation period and phenotype. Mouse quantitative trait locus (QTL) studies demonstrate multiple modifiers of incubation time unlinked to Prnp, suggesting the existence of homologous human prion disease modifiers, but direct evidence of these has been lacking. We investigated the correlation of age at onset and death, expressed as a composite Z score, between parents and offspring in three large UK inherited prion disease kindreds. Our analysis suggests that overall heritability of the composite phenotype is 0.55 (95% CI 0.35–0.75). This measure may be an underestimate of the total genetic contribution to phenotypic heterogeneity as the analysis does not incorporate the effect of PRNP‐linked modifiers. Although the confidence intervals are wide, these data suggest a significant heritable component to phenotypic variability and support attempts to identify human prion disease modifier genes which would be important in understanding the epidemiology of variant Creutzfeldt–Jakob disease (vCJD) in populations with significant exposure to bovine spongiform encephalopathy (BSE) prions. © 2008 Wiley‐Liss, Inc.
Structure–properties relations of the drawn poly(ethylene terephthalate) filament sewing thread
Authors: Rudolf Andreja , Smole Majda Sfiligoj 
Published: August 2008

AbstractThis article presents research into draw ratio influence on the structure–properties relationship of drawn PET filament threads. Structural modification influence due to the drawing conditions, i.e., the birefringence and filament crystallinity, on the mechanical properties was investigated, as well as the shrinkage and dynamic mechanical properties of the drawn threads. Increasing draw ratio causes a linear increase in the birefringence, degree of crystallinity, filament shrinkage, and a decrease in the loss modulus. In addition, loss tangent and glass transition temperature, determined at the loss modulus peak, were increased by drawing. The observed structural changes influence the thread's mechanical properties, i.e., the breaking tenacity, elasticity modulus, and tension at the yield point increase, while breaking extension decreases by a higher draw ratio. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Covalent immobilization of an antimicrobial peptide on poly(ethylene) film
Authors: Steven Matthew D. , Hotchkiss Joseph H. 
Published: August 2008

AbstractAn antimicrobial film was produced by covalently attaching synthetic peptide E14LKK to poly(ethylene) film. E14LKK is a 14 residue, magainin‐class peptide with broad‐spectrum antimicrobial activity. The poly(ethylene) surface was first oxidized with chromic/sulphuric acid, then PEGylated by using carbodiimide chemistry to attach ω‐amino‐α‐carboxyl‐poly(ethylene glycol) (PEG). The peptide was covalently coupled to the free terminus of the PEG, again using carbodiimide coupling. Surface contact angles for distilled water decreased from 101° initially to 61° following oxidation and 45° following PEGylation. Film surface chemistry showed the expected changes during the modifications: dye adsorption assays indicated changes in the number of acidic and basic groups and X‐ray photoemission spectroscopy showed increasing oxygen and nitrogen levels. Antimicrobial activity was demonstrated in broth cultures against E.coli: growth was reduced by atleast 3 log cycles compared to controls. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Grafting of acrylonitrile onto allylated caesarweed fibers by potassium permanganate – N,N′‐dimethylacetamide redox pair
Authors: Eromosele I. C. , Eromosele C. O. , Funmilayo D. O. 
Published: August 2008

AbstractCaesarweed fiber, Urena lobata, was modified by successive treatment with sodium hydroxide and allylchloride in diethylether to yield an average degree of substitution of 2.73 allyl moieties per anhydroglucose unit. The presence of allyl moieties on the fiber was confirmed by infrared spectroscopy. Graft copolymerization of acrylonitrile onto the unmodified and allyl‐modified fibers was initiated by potassium permanganate –N,N′‐dimethylacetamide redox pair in aqueous medium. The allyl fiber was markedly less reactive than the unmodified fiber with graft yields for the latter a factor of 2.3 higher than those of the former. This was attributed to resonance stabilization of allylic macroradicals of the fiber. The graft yield showed positive dependence on N,N′‐dimethylacetamide concentration in the range, 9.0–45.0 × 10−4M with Pg/Pgo of up to 1.39 at the highest concentration. The conversion in graft yield was however characterized by a plateau at the latter concentration and was ascribed to termination of grafted polymer chains by methylacetylaminomethyl radical initiating species. Spectroscopic evidence in support of the latter was the absorption peak at 1680 cm−1 for the graft copolymers, characteristic of CO stretching vibration for tertiary amide. Acetic acid, at concentrations in the range 0.28–2.22M, was inimical to grafting of acrylonitrile onto allylfibre with Pg/Pgo, of less than one. Grafting onto allylfiber showed positive temperature dependence in the range, 30–50°C with calculated activation energy of 12.3 kcal mol−1 for the graft polymerization reaction. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
A novel approach for improvement of the interfacial binding of ceramics for dental materials: Chemical treatment and oxygen plasma etching
Authors: Çökeliler Dilek , Erkut Selim , Shard Alex G. , Akdoğan Ebru , Özden Nehir , İmirzalıoğlu Pervin , Mutlu Mehmet 
Published: August 2008

AbstractDental ceramic is one of the most widely used materials in the dental industry because of its extensive use in resin‐bonded restorations and porcelain repair systems. In this study, two approaches were applied to dental ceramic surfaces for improvement in the wettability and surface energy of the effective resin–ceramic interfacial binding. One group of dental ceramics was treated by glow discharge with oxygen at a discharge power of 20 W and for an exposure time of 15 min. The other group was dipped onto hydrofluoric acid (HF) solution. Then, the samples were washed with distilled water and dried at the room temperature before the oxygen plasma treatment. The effectiveness of the two approaches was compared by means of changes in the surface wettability and polarity as measured by both the sessile drop and captive bubble techniques. Oxygen plasma treatment increased the surface wettability, but a greater increase was found with HF etching before the oxygen plasma treatment. This result was demonstrated by the decrease in the static contact angle as measured by the sessile drop technique (53.6 ± 4.19 to 27.7 ± 3.30). In addition, with the combination of the prechemical treatment with HF and the oxygen plasma treatment, the polarity increased more dramatically (0.706 ± 0.013 to 0.845 ± 0.008). The surface chemical composition and physical morphology were investigated by X‐ray photoelectron spectroscopy and scanning electron microscopy. Furthermore, the HF etching before oxygen plasma treatment was found to improve the shear bond strength, and it was significantly stronger than that of the groups treated with oxygen only for the resin composite materials (p < 0.05). This two‐step treatment could be a new approach for the activation of dental ceramic discs. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Wear resistance of low‐temperature plasma‐polymerized organosilica deposited on poly(ethylene terephthalate): The effect of discharge powers
Authors: Lin Yung‐Sen , Chen Ching‐Lun 
Published: August 2008

AbstractAn investigation was conducted into plasma polymerization of transparent organosilica (SiOxCy) onto flexible transparent polyethylene terephthalate (PET) substrates for improving wear resistance. The plasma‐polymerized SiOxCy with tetramethylsilane (TMS) and oxygen (O2) gases in room temperature (23°C) was proven to highly enhance the wear resistance from the completely worn of untreated PET substrates to no worn of TMS‐oxygen plasma‐polymerized PET substrates at higher discharge powers, while the wear test of 300 cycles at 300 g loading with a steel wool was applied. The performance of wear resistance on PET substrates was found to be strongly dependent on the surface characteristics of PET substrates. The surface hardness of PET substrates was determined by the pencil test. The surface morphology of PET substrate was observed by atomic force microscopy (AFM). The atomic compositions and chemical bondings of TMS‐oxygen plasma‐polymerized organosilicas were analyzed by means of X‐ray photoelectron spectroscopy (XPS). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Evaluation of polymethacrylic ionomer as compatibilizers for MCPA6/clay composites
Authors: Wu Tongfei , Liu Andong , Xie Tingxiu , Yang Guisheng 
Published: August 2008

AbstractThe compatibilization effects provided by polymethacrylic ionomer (PMMA ionomer) on monomer‐casting polyamide6 (MCPA6)/clay (pristine sodium montmorillonite) composites were studied in this work. The PMMA ionomer used in this study was sodium polymethacrylate ionomer (PMMA Na+‐ionomer), which is a copolymer of methyl methacrylate and sodium methacrylate, prepared using emulsion polymerization. MCPA6/clay/PMMA Na+‐ionomer composites were prepared by in situ anionic ring‐opening polymerization (AROP) of ε‐caprolactam (CLA). X‐ray diffraction (XRD) and transmission electron microscopy (TEM) plus rheological measurement were used to characterize those composites. The results indicated that PMMA Na+‐ionomer is a good compatibilizer for this system. With increasing PMMA Na+‐ionomer content, a better dispersion of clay layers was successfully achieved in the MCPA6 matrix. Furthermore, differential scanning calorimetry (DSC) and XRD results indicated that well dispersed silicate layers limit the mobility of the MCPA6 molecule chains to crystallize, reduce the degree crystalline, and favor the formation of the γ‐crystalline form of the MCPA6 matrix. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Improvement of the thermal stability of polyhydroxybutyrates by grafting with maleic anhydride by different methods: Differential scanning calorimetry, thermogravimetric analysis, and gel permeation chromatography
Authors: Hong Shinn‐Gwo , Lin Yi‐Che , Lin Chia‐Hau 
Published: August 2008

AbstractThe crystallization and thermal degradation behaviors of polyhydroxybutyrate (PHB) grafted with maleic anhydride (MA) by different techniques were analyzed with differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and gel permeation chromatography (GPC). The results of DSC, TGA, and GPC analyses indicated that the grafting method could affect the crystallization rate, crystallinity, and thermal stability of PHB because of changes in the molecular weight of PHB and the amount of MA grafted during the reaction. The reduction of the molecular weight of PHB that reacted during the processing followed this order of methods: melt grafting > solvent grafting > mechanical grafting. However, the grafting ratio of MA followed this order of methods: melt grafting > mechanical grafting > solvent grafting. All three grafting methods significantly improved the thermal stability, therefore increasing the crystallization rate and melting temperature of the as‐received PHB. A grafting ratio of MA as low as 0.07 wt % could result in a significant improvement in the heat resistance of PHB. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Influence of magnesium carbonate loading on the compound properties of polychloroprene, natural rubber, and their blends
Authors: Sae‐Oui Pongdhorn , Sirisinha Chakrit , Hatthapanit Kannika , Phewthongin Nilobon 
Published: August 2008

AbstractThe effect of magnesium carbonate (MgCO3) loading on the compound properties of polychloroprene (CR), natural rubber (NR), and their blends was investigated. The studied properties included Mooney viscosity, cure characteristics, and degree of filler–filler interaction. In addition to MgCO3 loading, the effect of the blend ratio on such properties was simultaneously determined. The results reveal that, regardless of the rubber type and blend ratio, increasing MgCO3 loading resulted in not only an increase in the compound viscosity, but also in the enhancements of the cure rate and state of cure. However, the effect of MgCO3 loading on the overcured behavior was strongly dependent on the rubber type and blend ratio. For CR, the presence of MgCO3 accelerated postcuring, whereas the opposite results were found for NR, in which the reversion rate was promoted. For CR/NR blends, a plateau behavior was obtained at a 50/50 blend ratio, where the degrees of postcuring and reversion were counterbalanced. The results also reveal that when MgCO3 was loaded at low concentrations (≤20 phr), the degree of filler–filler interaction was very low and had no significant effect on the compound properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effect of the phase ratio on the particle properties of poly(vinyl chloride) resins produced by suspension polymerization
Authors: Etesami N. , Esfahany M. Nasr , Bagheri R. 
Published: August 2008

AbstractThe effects of the dispersed phase to continuous phase ratio (weight of VCM (gr)/weight of water (gr) (φ = gVCM/gwater)) on the particle properties of a poly(vinyl chloride) (PVC) suspension were investigated experimentally. A series of experiments were performed with different φ values in a pilot‐scale reactor. The cold plasticizer absorption of the resin decreased with φ. Scanning electron micrographs showed that by the reduction of φ, many of the produced particles had a regular shape, a smooth surface, and greater porosity. An increase in φ caused a wider and multimodal particle size distribution of the produced PVC particles. The mean particle size and bulk density also increased with φ, whereas the molecular weight and polydispersity index did not change. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effect of chemical treatments on the mechanical, flow, and morphological properties of talc‐ and kaolin‐filled polypropylene hybrid composites
Authors: Abu Bakar M. B. , Leong Y. W. , Ariffin A. , Mohd Ishak Z. A. 
Published: August 2008

AbstractThis study was performed with commercially available phenyl trimethoxysilane (PTMS) and neoalkoxytitanate [i.e., neopentyl(diallyl)oxytri(dioctyl)phosphato titanate (LICA 12)] as coupling agents. PTMS and LICA 12 were used to treat talc and kaolin to compare their effects with untreated fillers upon incorporation into polypropylene (PP). Single‐filler PP composites (containing either talc or kaolin) and hybrid‐filler composites (containing a mix of both talc and kaolin) were compounded in a twin‐screw extruder and subsequently injection‐molded into dumbbells. The incorporation of PTMS and LICA 12 slightly decreased the tensile and flexural properties in terms of modulus and strength but increased the elongation at break for both single‐filler and hybrid‐filler composites. There was also a significant improvement in the impact strength of the composites, particularly those treated with LICA 12. The hybrid composites, through the synergistic coalescence of positive characteristics from talc and kaolin with the aid from chemical treatment provided an economically advantageous material with mechanical properties comparable to those of the single‐filler‐filled PP composites. Further investigations on flow and morphological properties were also done to correlate the mechanical properties of the single‐ and hybrid‐filler‐filled PP composites. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effect of the talc filler content on the mechanical properties of polypropylene composites
Authors: Lapcik Lubomir , Jindrova Pavlina , Lapcikova Barbora , Tamblyn Richard , Greenwood Richard , Rowson Neil 
Published: August 2008

AbstractThis research examines the effect of a microsize/nanosize talc filler on the physicochemical and mechanical properties of filled polypropylene (108MF10 and 33MBTU from Saudi Basic Industries Corp. and HE125MO grade from Borealis) composite matrices. A range of mechanical properties were measured [tensile properties, bending properties, fracture toughness, notched impact strength (at the ambient temperature and −20°C), strain at break, and impact strength] along with microhardness testing and thermal stability testing from 40 to 600°C as measured by differential thermal analysis and thermogravimetric analysis. Increasing filler content lead to an increase in the mechanical strength of the composite material with a simultaneous decrease in the fracture toughness. The observed increase in tensile strength ranged from 15 to 25% (the maximum tensile strength at break was found to be 22 MPa). The increase in mechanical strength simultaneously led to a higher brittleness, which was reflected in a decrease in the mean impact strength from the initial 18 kJ/m2 (for the virgin polypropylene sample) to 14 kJ/m2, that is, a 23% decrease. A similar dependency was also obtained for the samples conditioned at −20°C (a decrease of 12.5%). With increasing degree of filling of the talc–polypropylene composite matrix, the thermooxidative stability increased; the highest magnitude was obtained for the 20 wt % sample (decomposition temperature = 482°C, cf. 392°C for the virgin polymer). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and characterization of temperature‐responsive poly(vinyl alcohol)‐based copolymers
Authors: Pan Yuanfeng , Xiao Huining , Zhao Guanglei , He Beihai 
Published: August 2008

AbstractA poly(vinyl alcohol) (PVA)/sodium acrylate (AANa) copolymer was synthesized to improve the water solubility of PVA at the ambient temperature. Furthermore, a series of temperature‐responsive acetalyzed poly(vinyl alcohol) (APVA)‐co‐AANa samples of various chain lengths, degrees of acetalysis (DAs), and comonomer contents were prepared via an acid‐catalysis process. Fourier transform infrared and 1H‐NMR techniques were used to analyze the compositions of the copolymers. The measurement of the turbidity change for APVA‐co‐AANa aqueous solutions at different temperatures revealed that the lower critical solution temperature (LCST) of the copolymers could be tailored through the control of the molecular weight of the starting PVA‐co‐AANa, DA, and comonomer ratios. Lower LCSTs were observed for APVA‐co‐AANa with a longer chain length, a higher DA, and fewer acrylic acid segments. In addition, the LCSTs of the APVA‐co‐AANa aqueous solutions appeared to be salt‐sensitive. The LCSTs decreased as the concentration of NaCl increased. Moreover, atomic force microscopy images of APVA‐co‐AANa around the LCST also proved the temperature sensitivity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
ToF‐SIMS investigation of epoxy resin curing reaction at different resin to hardener ratios
Authors: Awaja Firas , van Riessen Grant , Kelly Georgina , Fox Bronwyn , Pigram Paul J. 
Published: August 2008

AbstractTime‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) and principal components analysis (PCA) were used to analyze diglycidyl ether of bisphenol A (DGEBA) and diglycidyl ether of bisphenol F (DGEBF) epoxy resin blend cured with isophorone diamine (IPD) hardener at different resin to hardener ratios. The aim was to establish correlations between the hardener concentration and the nature and progress of the crosslinking reaction. Insights into the cured resin structure revealed using ToF‐SIMS are discussed. Three sets of significant secondary ions have been identified by PCA. Secondary ions such as C14H7O+, CHO+, CH3O+, and C21H24O4+ showed variance related to the completion of the curing reaction. Relative intensities of CxHyNz+ ions in the cured resin samples are indicative of the un‐reacted and partially reacted hardener molecules, and are found to be proportional to the resin to hardener mixing ratio. The relative ion intensities of the aliphatic hydrocarbon ions are shown to relate to the cured resin crosslinking density. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Phthalyl chitosan–poly(ethylene oxide) semi‐interpenetrating polymer network microparticles for oral protein delivery: An in vitro characterization
Authors: Rekha M. R. , Sharma C. P. 
Published: August 2008

AbstractPhthalyl chitosan (PC) was synthesized and phthalyl chitosan–poly(ethylene oxide) (PCP) semi‐interpenetrating network microparticles were developed by ionic crosslinking with sodium tripolyphosphate. The characterization of PCP particles was done, and these particles were compared with PC and native chitosan (NC) microparticles. The PCP particle size was around 1.3 μm with a ζ potential of about −28.6 ± 12.6 mV and an insulin loading efficiency of 89.6%. The release studies were done at pH 1.2 and 7.4, which indicated a minimal release at pH 1.2 compared to that at pH 7.4. The degree of swelling was observed to be higher in PCP than in PC or NC particles. The in vitro mucin‐binding capacity and the intestinal mucoadhesiveness of the particles were evaluated. The PCP particles were highly mucoadhesive, and correspondingly, the mucin‐binding capacity was lower for these particles; this is necessary for any matrix to be a successful mucoadhesive. These results suggest the usefulness of these particles as a potential candidate for oral insulin‐delivery systems. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
The Primary Cilium of Connective Tissue Cells: Imaging by Multiphoton Microscopy
Authors: Donnelly Eve , Williams Rebecca , Farnum Cornelia 
Published: August 2008

AbstractThree‐dimensional reconstruction of a multiphoton image stack showing primary cilia (green)
tenocyte nuclei (blue), and collagen (red) in extensor tendon. From “The Primary Cilium of Connective Tissue Cells: Imaging by Multiphoton Microscopy,” by Eve Donnelly, et al., on page 1062, in this issue. Anatomical Record 291:1062–1073.
The importance of reporting disease activity states in rheumatoid arthritis clinical trials
Authors: Aletaha Daniel , Funovits Julia , Smolen Josef S. 
Published: August 2008

AbstractObjectiveTo compare the value of reporting treatment effects in rheumatoid arthritis (RA) as relative change from baseline (e.g., American College of Rheumatology [ACR] responder status) with the value of evaluating absolute disease activity states (e.g., remission).MethodsWe pooled data from several recent RA clinical trials and evaluated patients who had completed a 1‐year treatment period (n = 629). We compared levels of functional impairment and radiographic progression among patients meeting the ACR 50% or 70% improvement criteria (ACR50 and ACR70 responders, respectively) who attained remission of disease, low disease activity, or moderate disease activity after 1 year, as assessed by the Simplified Disease Activity Index and the Disease Activity Score in 28 joints.ResultsWithin the ACR50 and ACR70 responder groups, functional disability and radiographic progression were lowest in patients who had attained disease remission at 1 year, compared with those who had attained low or moderate disease activity. When patients attained the same disease activity category, physical function and radiographic progression did not differ significantly with different response states.ConclusionFunctional and radiographic outcomes are different in patients depending on the disease activity category they attain, even if the same level of response (change from baseline) is achieved. Among patients who attain the same disease activity category, the degree of response they experience does not seem to matter. Assessing actual disease activity as well as disease activity states should constitute an integral part of clinical trial data reporting.