bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and characterization of novel poly(dimethylsiloxane)/polyindole composites
Authors: Ürkmez Göknur , Sarı Bekir , Ünal Halil İbrahim 
Published: March 2011

AbstractA series of composites of polyindole (PIN) and poly(dimethylsiloxane) (PDMS) were synthesized chemically using FeCl3 as an oxidant agent in anhydrous media. The composites were characterized by FTIR and UV‐visible spectroscopies, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), X‐ray diffraction (XRD), elemental analysis, inductively coupled plasma‐optic emission spectroscopy (ICP‐OES), magnetic susceptibility, stress–strain experiments, and conductivity measurements. The conductivities of PIN at different temperatures were also measured and it was revealed that their conductivities were slightly increased with increasing temperature. Moreover, the freestanding films of PDMS/PIN composites were prepared by casting on glass Petri dishes to examine their stress–strain properties. From thermogravimetric analysis results it was found that PDMS/PIN composites were thermally more stable than PIN. Thermal stabilities of PDMS/PIN composites increased with increasing PIN content. It was found that the conductivities of PDMS/PIN composites depend on the indole content in the composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Properties and origins of high‐performance poly(phenylene oxide)/cyanate ester resins for high‐frequency copper‐clad laminates
Authors: Gao Rui , Gu Aijuan , Liang Guozheng , Dai Shankai , Yuan Li 
Published: March 2011

AbstractA high‐performance matrix is the key base for the fabrication of high‐frequency copper‐clad laminates. A high‐performance resin system based on commercial poly(phenylene oxide) (PPO) and 2,2′‐bis(4‐cyanatophenyl) isopropylidene (BADCy), coded as PPO‐n/BADCy (where n is the weight parts of PPO per 100 weight parts of BADCy), was developed. The effect of PPO on the key properties, including the dielectric and thermal properties, water resistance, and toughness, of the cured resins was investigated extensively. The results show that PPO not only catalyzed the curing reaction of BADCy but also reacted with BADCy to form a single‐phase structure. Furthermore, compared with the cured BADCy resin with 1 phr epoxy resin as a catalyst, the cured PPO‐n/BADCy resins had significantly increased impact strengths and decreased dielectric constants, loss, and water resistance. The reasons behind these desirable improvements are discussed from the view of structure–property relationships. These results suggest that the PPO‐n/BADCy system has great potential to be used as a matrix for high‐frequency copper‐clad laminates or other advanced composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Molecularly imprinted monolithic material for the extraction of three organic acids from Salicornia herbacea L
Authors: Zhu Tao , Li Shengnan , Row Kyung Ho 
Published: March 2011

AbstractA molecularly imprinted monolithic material was designed and prepared by in situ thermally initiated copolymerization for the extraction of protocatechuic acid, caffeic acid, and ferulic acid from Salicornia herbacea L. Field emission scanning electron microscopy and offline solid‐phase extraction (SPE) were investigated for the characterization of this material. The extract samples were loaded onto and passed through the monolithic material; the target compounds were selectively retained on the material, whereas other interfering substances were quickly washed out. Chromatographic analysis was conducted on a C18 column with ultraviolet detection at 270 nm, and an eluting solution consisting of acetonitrile, water, and acetic acid (14/86/0.5 v/v/v, pH 5.0) was used as the mobile phase at a flow rate of 0.8 mL/min. The linearity was confirmed in the concentration ranges of 0.10–200.00, 0.20–400.00, and 0.30–600.00 μg/mL for protocatechuic acid, caffeic acid, and ferulic acid, respectively, with r2 greater than 0.9997. The SPE recoveries of the three organic acids ranged from 71.08 to 81.02%, and the coefficient of variation (precision) was 3.08–5.70%. This method is simple, economical, and specific and has been used successfully in the extraction of three organic acids from S. herbacea L. This cartridge can be used as a potential tool for the extraction of drugs from natural plants. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Dynamic rheological behavior and microcrystalline structure of dioctyl phthalate plasticized poly(vinyl chloride)
Authors: Zou Jiajia , Su Lin , You Feng , Chen Guangshun , Guo Shaoyun 
Published: March 2011

AbstractThe dynamic rheological behavior of poly(vinyl chloride) (PVC)/dioctyl phthalate (DOP) systems were studied as a function of DOP content and melting temperature. The dynamic rheological behavior of the PVC/DOP systems was found to be remarkably affected by the DOP content. The observed curves of storage modulus (G′) versus frequency were well fitted to an empirical equation (G′ = G′0 + Kωn, where G′0 is the low‐frequency yield value of the storage modulus, the exponent n is a dependent index of frequency, K is a constant coefficient, and ω is the angular frequency). The loss tangent and/or phase angle increased remarkably at a higher DOP content. There was an apparent critical DOP content transition where the dynamic rheological behavior of the PVC/DOP systems changed greatly. Scanning electron microscopy observations revealed the existence of a multiscale particle structure in the PVC/DOP systems. For the PVC/DOP (100/70) system, with increasing melting temperature, its dynamic rheological behavior showed an apparent mutation at about 190°C. Differential scanning calorimetry (DSC) analysis confirmed that the high elastic networks in the PVC/DOP systems were closely related to the microcrystalline structure of PVC. The transitions in the curves of the gelation degree and crystallinity versus the DOP content corresponded well to the DOP content transition in the dynamic rheological behavior. DOP could inhibit the secondary crystallite of PVC and almost had no effect on the primary crystallite of PVC. The coexistence of the microcrystalline structure of PVC and the plasticizer (DOP) resulted in high elastic networks in the PVC/DOP systems. The DSC results explained the DOP content transition and the temperature transition in the dynamic rheological behavior of the PVC/DOP systems well. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Influence of small rubber particles on the environmental stress cracking of high impact polystyrene
Authors: Grassi V. G. , Dal Pizzol M. F. , Forte M. M. C. , Amico S. C. 
Published: March 2011

AbstractThis article exploits the influence of rubber particle size (RPS) and rubber crosslinking on environmental stress cracking resistance (ESCR) of high impact polystyrene (HIPS), with special interest on the influence of small rubber particles fraction. Three commercial HIPS of high ESCR were selected and four batches of HIPS were prepared in‐house, including samples based on high cis and very high viscosity polybutadiene (PB). Their morphologies were analyzed by low angle laser light scattering, optical microscopy, and transmission electron microscopy, and the samples were submitted to flexural ESCR tests with fatty agents. The ESCR to sunflower oil was found to increase with the reduction of the rubber particles fraction smaller than 1–2 micron. Results have also confirmed that an increase in RPS is the key parameter to promote ESCR, although there is limit for RPS to be effective on ESCR improvement. The reduction of small rubber particles fraction in HIPS was achieved by using a high cis PB, that promotes low grafting efficiency of polystyrene onto PB backbone because of the low content of 1,2 vinyl isomer. Besides the ESCR improvements, HIPS with high cis PB showed higher elastic modulus and impact resistance than HIPS containing medium cis PB, which is desired for thickness reduction in food packaging and refrigeration cabinets. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
ZnO nanocrystallites/cellulose hybrid nanofibers fabricated by electrospinning and solvothermal techniques and their photocatalytic activity
Authors: Ye Shuhai , Zhang Dong , Liu Haiqing , Zhou Jinping 
Published: March 2011

AbstractZnO nanocrystallites have been in situ embedded in cellulose nanofibers by a novel method that combines electrospinning and solvothermal techniques. Zn(OAc)2/cellulose acetate (CA) precursor hybrid nanofibers with diameter in the range of 160–330 nm were first fabricated via the electrospinning technique using zinc acetate as precursor, CA as the carrier, and dimethylformamide (DMF)/acetone(2 : 1) mixture as cosolvent. The precursor nanofibers were transformed into ZnO/cellulose hybrid fibers by hydrolysis in 0.1 mol/L NaOH aqueous solution. Subsequently, these hybrid fibers were further solvothermally treated in 180°C glycerol oil bath to improve the crystallite structure of the ZnO nanoparticles containing in the nanofibers. The structure and morphology of nanofibers were characterized by scanning electron microscopy, transmission electron microscopy, and X‐ray diffraction. It was found that hexagonal structured ZnO nanocrystallites with the size of ∼ 30 nm were dispersed on the nanofiber surfaces and within the nanofibers with diameter of about 80 nm. The photocatalytic property of the ZnO/cellulose hybrid nanofibers toward Rhodamine (RhB) was tested under the irradiation of visible light. As a catalyst, it inherits not only the photocatalytic ability of nano‐ZnO, but also the thermal stability, good mechanical property, and solvent‐resistibility of cellulose nanofibers. The key advantages of this hybrid nanofiber over neat ZnO nanoparticles are its elasticity, dimensional stability, durability, and easy recyclability. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Morphological Development and Expression of Neurotrophin Receptors in the Laryngeal Sensory Corpuscles
Authors: Yamamoto Yoshio , Hashiguchi Momo , Yamaguchi‐Yamada Misuzu 
Published: March 2011

AbstractMorphological development of sensory structures in the laryngeal mucosa of postnatal rats was observed by use of immunohistochemistry for protein gene‐product 9.5 (PGP9.5). Moreover, expression changes of high affinity neurotrophin receptors, TrkA, TrkB and TrkC, and low affinity neurotrophin receptor p75NTR were examined to elucidate the relationship to morphogenesis. Intraepithelial nerve endings and parent axons of the laminar endings with immunoreactivity for PGP9.5 have already appeared in the rat on embryonic day 18 (E18) as well as solitary chemoreceptor cells in the glottic cleft. According to neurotrophin receptors, TrkA immunoreactivity were observed on and after postnatal week 3 (3W) in the nervous sensory structures, that is, free nerve endings, laminar endings and sub‐ and intragemmal plexuses of the taste buds. In the laminar endings, TrkC immunoreactivity was also observed on and after 3W. According to the laryngeal sensory cells, the solitary chemoreceptor cells were immunoreactive to TrkA, TrkB, and TrkC on and after postnatal day 3 (P3). In the taste buds in arytenoid region, taste cells were immunoreactive for TrkA, TrkB, and TrkC on and after 3W, P14, and 3W, respectively. Immunoreactivity for p75NTR was observed on the surface of taste cells on and after P9. The results of the present study suggest that sensory structures in the laryngeal mucosa were developed on perinatal days to involve respiratory reflex, and that neurotrophin receptors may take part in the regulation and maintenance of sensory structures. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Muscle Spindle Composition and Distribution in Human Young Masseter and Biceps Brachii Muscles Reveal Early Growth and Maturation
Authors: Österlund Catharina , Liu Jing‐Xia , Thornell Lars‐Eric , Eriksson Per‐Olof 
Published: March 2011

AbstractSignificant changes in extrafusal fiber type composition take place in the human masseter muscle from young age, 3–7 years, to adulthood, in parallel with jaw‐face skeleton growth, changes of dentitions and improvement of jaw functions. As motor and sensory control systems of muscles are interlinked, also the intrafusal fiber population, that is, muscle spindles, should undergo age‐related changes in fiber type appearance. To test this hypothesis, we examined muscle spindles in the young masseter muscle and compared the result with previous data on adult masseter spindles. Also muscle spindles in the young biceps brachii muscle were examined. The result showed that muscle spindle composition and distribution were alike in young and adult masseter. As for the adult masseter, young masseter contained exceptionally large muscle spindles, and with the highest spindle density and most complex spindles found in the deep masseter portion. Hence, contrary to our hypothesis, masseter spindles do not undergo major morphological changes between young age and adulthood. Also in the biceps, young spindles were alike adult spindles. Taken together, the results showed that human masseter and biceps muscle spindles are morphologically mature already at young age. We conclude that muscle spindles in the human young masseter and biceps precede the extrafusal fiber population in growth and maturation. This in turn suggests early reflex control and proprioceptive demands in learning and maturation of jaw motor skills. Similarly, well‐developed muscle spindles in young biceps reflect early need of reflex control in learning and performing arm motor behavior. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
The Response of Cranial Biomechanical Finite Element Models to Variations in Mesh Density
Authors: Bright Jen A. , Rayfield Emily J. 
Published: March 2011

AbstractFinite element (FE) models provide discrete solutions to continuous problems. Therefore, to arrive at the correct solution, it is vital to ensure that FE models contain a sufficient number of elements to fully resolve all the detail encountered in a continuum structure. Mesh convergence testing is the process of comparing successively finer meshes to identify the point of diminishing returns; where increasing resolution has marginal effects on results and further detail would become costly and unnecessary. Historically, convergence has not been considered in most CT‐based biomechanical reconstructions involving complex geometries like the skull, as generating such models has been prohibitively time‐consuming. To assess how mesh convergence influences results, 18 increasingly refined CT‐based models of a domestic pig skull were compared to identify the point of convergence for strain and displacement, using both linear and quadratic tetrahedral elements. Not all regions of the skull converged at the same rate, and unexpectedly, areas of high strain converged faster than low‐strain regions. Linear models were slightly stiffer than their quadratic counterparts, but did not converge less rapidly. As expected, insufficiently dense models underestimated strain and displacement, and failed to resolve strain “hot‐spots” notable in contour plots. In addition to quantitative differences, visual assessments of such plots often inform conclusions drawn in many comparative studies, highlighting that mesh convergence should be performed on all finite element models before further analysis takes place. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Evidence of the transient nature of the Th17 phenotype of CD4+CD161+ T cells in the synovial fluid of patients with juvenile idiopathic arthritis
Authors: Cosmi Lorenzo , Cimaz Rolando , Maggi Laura , Santarlasci Veronica , Capone Manuela , Borriello Francesco , Frosali Francesca , Querci Valentina , Simonini Gabriele , Barra Giusi , Piccinni Marie Pierre , Liotta Francesco , De Palma Raffaele , Maggi Enrico , Romagnani Sergio , Annunziato Francesco 
Published: March 2011

AbstractObjectiveTo investigate the phenotype and function of CD4+ T cells in synovial fluid (SF) from the affected joints of children with oligoarticular‐onset juvenile idiopathic arthritis (JIA), and to establish a possible link with disease activity.MethodsCD4+ T cells were obtained from the peripheral blood (PB) and SF of 23 children with oligoarticular‐onset JIA, as well as from the PB of 15 healthy children. The cells were analyzed for the expression of CXCR3, CCR6, and CD161 and for the production of interferon‐γ and interleukin‐17A (IL‐17A). Spectratyping and clonotype analyses were performed to assess different T cell subsets.ResultsThe numbers of CD4+CD161+ cells showing either the Th1 or the Th17/Th1 phenotype were higher in the SF than in the PB of children with JIA. The few Th17 cells from JIA SF underwent a spontaneous shift to the Th1 phenotype in vitro, whereas Th17 cells from the PB of healthy children shifted only in the presence of JIA SF; this effect was neutralized by antibody blockade of IL‐12 activity. Spectratyping and clonotype analyses showed a similar skewing of the T cell receptor Vβ repertoire in both CD161+ Th17 cells and CD161+ Th1 cells derived from the SF of the same JIA patient. The frequencies of CD4+CD161+ cells, particularly the Th17/Th1 cells, in the JIA SF positively correlated with the erythrocyte sedimentation rate and levels of C‐reactive protein.ConclusionThese findings suggest that a shifting of CD4+CD161+ T cells from Th17 to the Th17/Th1 or Th1 phenotype can occur in the SF of children with oligoarticular‐onset JIA, and indicate that the accumulation of these cells is correlated with parameters of inflammation. Thus, the results support the hypothesis that these cells may play a role in JIA disease activity.
Paper 2: EUROCAT public health indicators for congenital anomalies in Europe
Authors: Khoshnood Babak , Greenlees Ruth , Loane Maria , Dolk Helen ,   on behalf of the EUROCAT Project Management Committee and a EUROCAT Working Group
Published: March 2011

AbstractOBJECTIVEThe purpose of this article is to present the specific public health indicators recently developed by EUROCAT that aim to summarize important aspects of the public health impact of congenital anomalies in a few quantitative measures.METHODSThe six indicators are: (1) congenital anomaly perinatal mortality, (2) congenital anomaly prenatal diagnosis prevalence, (3) congenital anomaly termination of pregnancy, (4) Down syndrome livebirth prevalence, (5) congenital anomaly pediatric surgery, and (6) neural tube defects (NTD) total prevalence. Data presented for this report pertained to all cases (livebirths, fetal deaths, or stillbirths after 20 weeks of gestation and terminations of pregnancy for fetal anomaly [TOPFA]) of congenital anomaly from 27 full member registries of EUROCAT that could provide data for at least 3 years during the period 2004 to 2008. Prevalence of anomalies, prenatal diagnosis, TOPFA, pediatric surgery, and perinatal mortality were calculated per 1000 births.RESULTSThe overall perinatal mortality was approximately 1.0 per 1000 births for EUROCAT registries with almost half due to fetal and the other half due to first week deaths. There were wide variations in perinatal mortality across the registries with the highest rates observed in Dublin and Malta, registries in countries where TOPFA are illegal, and in Ukraine. The overall perinatal mortality across EUROCAT registries slightly decreased between 2004 and 2008 due to a decrease in first week deaths. The prevalence of TOPFA was fairly stable at about 4 per 1000 births. There were variations in livebirth prevalence of cases typically requiring surgery across the registries; however, for most registries this prevalence was between 3 and 5 per 1000 births. Prevalence of NTD decreased by about 10% from 1.05 in 2004 to 0.94 per 1000 in 2008.CONCLUSIONIt is hoped that by publishing the data on EUROCAT indicators, the public health importance of congenital anomalies can be clearly summarized to policy makers, the need for accurate data from registries emphasized, the need for primary prevention and treatment services highlighted, and the impact of current services measured. Birth Defects Research (Part A), 2011.© 2011 Wiley‐Liss, Inc.
The detection threshold for extremely low frequency magnetic fields may be below 1000 nT‐Hz in mice
Authors: Prato Frank S. , Desjardins‐Holmes Dawn , Keenliside Lynn D. , DeMoor Janice M. , Robertson John A. , Stodilka Robert Z. , Thomas Alex W. 
Published: March 2011

AbstractPrevious experiments with mice have shown that a repeated 1 h daily exposure to an ambient magnetic field shielded environment induces analgesia (anti‐nociception). This shielding reduces ambient static and extremely low frequency magnetic fields (ELF‐MF) by approximately 100 times for frequencies below 120 Hz. To determine the threshold of ELF‐MF amplitude that would attenuate or abolish this effect, 30 and 120 Hz magnetic fields were introduced into the shielded environment at peak amplitudes of 25, 50, 100 and 500 nT. At 30 Hz, peak amplitudes of 50, 100, and 500 nT attenuated this effect in proportion to the amplitude magnitude. At 120 Hz, significant attenuation was observed at all amplitudes. Exposures at 10, 60, 100, and 240 Hz with peak amplitudes of 500, 300, 500, and 300 nT, respectively, also attenuated the induced analgesia. No exposure abolished this effect except perhaps at 120 Hz, 500 nT. If the peak amplitude frequency product was kept constant at 6000 nT‐Hz for frequencies of 12.5, 25, 50, and 100 Hz, the extent of attenuation was constant, indicating that the detection mechanism is dependent on the nT‐Hz product. A plot of effect versus the induced current metric nT‐Hz suggests a threshold of ELF‐MF detection in mice at or below 1000 nT‐Hz. Bioelectromagnetics 32:561–569, 2011. © 2011 Wiley‐Liss, Inc.
A strategy to determine operating parameters in tissue engineering hollow fiber bioreactors
Authors: Shipley R.J. , Davidson A.J. , Chan K. , Chaudhuri J.B. , Waters S.L , Ellis M.J. 
Published: March 2011

AbstractThe development of tissue engineering hollow fiber bioreactors (HFB) requires the optimal design of the geometry and operation parameters of the system. This article provides a strategy for specifying operating conditions for the system based on mathematical models of oxygen delivery to the cell population. Analytical and numerical solutions of these models are developed based on Michaelis–Menten kinetics. Depending on the minimum oxygen concentration required to culture a functional cell population, together with the oxygen uptake kinetics, the strategy dictates the model needed to describe mass transport so that the operating conditions can be defined. If cmin ≫ Km we capture oxygen uptake using zero‐order kinetics and proceed analytically. This enables operating equations to be developed that allow the user to choose the medium flow rate, lumen length, and ECS depth to provide a prescribed value of cmin. When $c_{{\rm min}} {\not {\gg }}K_{m} $, we use numerical techniques to solve full Michaelis–Menten kinetics and present operating data for the bioreactor. The strategy presented utilizes both analytical and numerical approaches and can be applied to any cell type with known oxygen transport properties and uptake kinetics. Biotechnol. Bioeng. 2011; 108:1450–1461. © 2011 Wiley Periodicals, Inc.