bluuebunny/crossref_metadata_2025_split huggingface dataset:
Association between serotonin transporter gene polymorphism and eating disorders outcome: A 6‐year follow‐up study
Authors: Castellini Giovanni , Ricca Valdo , Lelli Lorenzo , Bagnoli Silvia , Lucenteforte Ersilia , Faravelli Carlo , Sorbi Sandro , Nacmias Benedetta 
Published: April 2012

AbstractEating disorder patients show different long‐term outcomes, and trait‐related alterations of serotonergic function, which might be related with the serotonin transporter (5‐HTT) gene. We studied the relationships between 5‐HTTLPR polymorphism, eating specific and general psychopathology and the long‐term outcome of anorexia nervosa (AN) and bulimia nervosa (BN) patients. We evaluated the distribution of the functional 5‐HTTLPR polymorphism in a series of 201 Italian, Caucasian, eating disorder patients (113 with AN and 88 with BN binge/purging (BP subtype) and in 150 Caucasian unrelated controls. Prior to starting an individual cognitive behavior therapy, a clinical assessment was performed by means of the structured clinical interview for DSM‐IV axis I disorders and several self‐report questionnaires. This assessment was repeated at the end of treatment, 3 years after the end of treatment and 3 years after the first follow‐up. Diagnostic changes between AN and BN were frequent (28.3%), and the presence of depressive disorders was associated with a higher rate of diagnostic crossover during the follow‐up period. The S‐allele of the 5‐HTTLPR genotype increases the risk susceptibility for both depressive comorbidity (OR = 4.23; 95% CI, 1.45–12.37) and diagnostic crossover during the follow‐up period in AN patients (OR = 5.04; 95% CI, 1.69–14.98). Logistic regression analyses confirmed these findings, when the interaction between genotype and psychiatric comorbidity as predictors of diagnostic instability in AN patients were taken into account. No significant association was found between 5‐HTTLPR genotype and recovery. The S‐allele of the 5‐HTTLPR genotype increases the risk for depressive disorders comorbidity, and moderates the long‐term outcome of anorectic patients. © 2012 Wiley Periodicals, Inc.
Morphology and thermal and mechanical properties of phosphonium vermiculite filled poly(ethylene terephthalate) composites
Authors: Zeng Xianshen , Cai Deming , Lin Zhidan , Cai Xiang , Zhang Xiuju , Tan Shaozao , Xu Yingbin 
Published: April 2012

AbstractA series of poly(ethylene terephthalate) (PET)/phosphonium vermiculite (P‐VMT) composites were prepared by a melt‐blending method, and we investigated the morphology and thermal and mechanical properties of the composites. We prepared P‐VMT with quaternary phosphonium salts using the common method followed by a cation‐exchange reaction. X‐ray diffraction showed that the phosphonium surfactants were partially intercalated into the vermiculite layers, The d‐spacing of the PET–clay sample was somewhat less than that of the P‐VMT because some degradation of the surfactant took place during melt processing. Compared with PET, the PET–clay composites had a lower decomposition temperature and showed a 17.4% increase in the tensile strength with a P‐VMT content of 3 wt %. Scanning electron microscopy and transmission electron microscopy demonstrated that P‐VMT had a homogeneous dispersion and good compatibility in the polymer matrix with a low content of additive and indicated that the P‐VMT content of 3 wt % was optimal. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis and characterization of novel pyridine‐based polyureas with enhanced solubility and high thermal stability
Authors: Ehsani Sara , Mehdipour‐Ataei Shahram , Mahmoodi Ali 
Published: April 2012

AbstractThe main aim of this study was the preparation of modified polyureas with improved thermal stability and solubility. Accordingly, a series of aromatic/aliphatic pyridine‐based polyureas was synthesized from the reaction of a novel diamine (DA) with different diisocyanates, including 4,4′‐diphenylmethane diisocyanate, toluene diisocyanate, 1,5‐naphthalene diisocyanate, and isophorone diisocyanate, by a solution polymerization route. The DA monomer was prepared via a two‐step reaction. The nucleophilic substitution reaction of oxydianiline with 6‐chloronicotinoylchloride led to the preparation of a diamide dichloro compound, and the subsequent reaction of this compound with 4‐aminophenol resulted in the preparation of the DA. After polymerization, the structural characterization and physical properties of the polymers were examined. The resulting polymers were soluble in common polar aprotic solvents, and they showed improved thermal stabilities in comparison with common polyureas. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of multiple extrusions on the impact properties of polypropylene/clay nanocomposites
Authors: Klitkou R. , Jensen E. A. , Christiansen J. de C. 
Published: April 2012

AbstractPolypropylene (PP)‐based polymer nanocomposites containing organically modified montmorillonite (OMMT) with and without maleic anhydride grafted PP, were compounded by twin‐screw extrusion. The extrusion process was repeated various numbers of times to increase the extruder residence time (TR) and, through that, the particle dispersion. Rheological measurements fitted to a modified Carreau–Yasuda model defining a melt yield stress were used to indicate changes in the particle dispersion with regard to TR. This analysis showed a monotonically increased dispersion of clay particles in the PP matrix with increasing extruder TR. The small‐strain tensile properties were tested at both ambient (20°C) and elevated (90°C) temperatures, and no significant changes were observed in the tensile strength or modulus as a function of TR. Instrumented Izod impact tests showed that the nanocomposite impact strength (σi) increased monotonically with increased TR by 70% from least dispersed to best dispersed, which was still 20% below the level for neat PP. Both the fracture initiation energy and propagation energy increased with TR, but the primary effect on σi came from the fracture propagation energy, which delivered 80% of the improvement. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Novel trifluoromethyl‐containing poly(amide–imide)s: Organosolubility, optical behavior, thermostability, and crystallinity
Authors: Behniafar Hossein , Sefid‐Girandehi Narges , Hosseinpour Mahdiyeh 
Published: April 2012

AbstractA new dicarboxylic acid monomer, 2,6‐bis(1,3‐dioxo‐5‐carboxyisoindolin‐2‐yl)‐4,4′‐bis(trifluoromethyl)‐1,1′‐diphenyl ether (IFDPE), bearing two preformed imide rings was synthesized via a three‐step manner from 4‐(trifluoromethyl)phenol and 4‐chloro‐3,5‐dinitrobenzotrifluoride. The monomer IFDPE was then used to prepare a series of novel trifluoromethyl‐containing poly(amide–imide)s via a direct phosphorylation polycondensation with various aromatic diamines. The intrinsic viscosities of the polymers were found to be in the range 0.86–1.02 d/g. The weight‐ and number‐average molecular weights of the resulting polymers were determined with gel permeation chromatography. The polymeric samples were readily soluble in a variety of organic solvents and formed low‐color, flexible thin films via solution casting. The values of the absorption edge wavelength were determined by ultraviolet–visible spectroscopy, and all of the resulting poly (amide–imide)s films exhibited high optical transparency. The resulting polymers showed moderately high glass‐transition temperatures in the range 295–324°C and had 10% weight loss temperatures in excess of 524°C in nitrogen. The crystallinity extents were qualitatively investigated with wide‐angle X‐ray diffraction measurements. Scanning electron microscopy images revealed an agglomerated bulk with nonuniformity on the surface. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Piezoelectric polymeric bicomponent fibers produced by melt spinning
Authors: Lund Anja , Jonasson Christian , Johansson Christer , Haagensen Daniel , Hagström Bengt 
Published: April 2012

AbstractMelt spinning of a novel piezoelectric bicomponent fiber, with poly(vinylidene fluoride) as the electroactive sheath component, has been demonstrated. An electrically conductive compound of carbon black (CB) and high density polyethylene was used as core material, working as an inner electrode. A force sensor consisting of a number of fibers embedded in a soft CB/polyolefin elastomer matrix was manufactured for characterization. The fibers showed a clear piezoelectric effect, with a voltage output (peak‐to‐peak) of up to 40 mV under lateral compression. This continuous all‐polymer piezoelectric fiber introduces new possibilities toward minimal single fiber sensors as well as large area sensors produced in standard industrial weaving machines. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Iminodiacetic acid‐containing polymer brushes grafted onto silica gel for preconcentration and determination of copper(II) in environmental samples
Authors: Panahi Homayon Ahmad , Mehmandost Nasrin , Moniri Elham , Galaev Igor Yu. 
Published: April 2012

AbstractSilica gel has been modified by silylation with 3‐mercaptopropyltrimethoxysilane followed by graft polymerization of dimethylacrylamide and (N,N‐bis‐carboxymethyl)amino‐3‐allylglycerol‐co‐dimethylacrylamide, synthesized via the reaction of allyl glycidyl ether with iminodiacetic acid. The sorbent, poly(AGE/IDA‐co‐DMAA)‐grafted silica gel, has been characterized by FTIR, elemental analysis, thermogravimetric analysis (TGA), FT‐Raman, and scanning electron microscopy and studied for the preconcentration and determination of trace amounts of Cu(II) ion in environmental water samples. The optimum pH value for quantitative sorption of Cu(II) in batch mode was 5.5 and desorption was achieved, using 0.5 mol L−1 nitric acid. The sorption capacity of functionalized sorbent is 32.3 mg g−1. The chelating sorbent was reused for 15 sorption–desorption cycles without any significant change in sorption capacity. The profile of copper uptake by the sorbent reflected good accessibility of the chelating sites in the poly(AGE/IDA‐co‐DMAA)‐grafted silica gel. Scatchard analysis demonstrated homogeneous nature of binding sites. The equilibrium adsorption data of Cu(II) on modified sorbent were analyzed by Langmuir, Freundlich, Temkin, and Redlich–Peterson models. Based on equilibrium adsorption data, the Langmuir, Freundlich, and Temkin constants were determined as 0.0665, 4.26, and 8.34, respectively, at pH 5.5 and 20°C. Adsorption isotherms were analyzed at different temperatures to obtain free energy, enthalpy, and entropy of adsorption. The method was applied for Cu(II) determination in sea water samples. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis and evaluation of a metal‐complexing imprinted polymer for Chinese herbs quercetin
Authors: Huangfu Fengyun , Wang Bing , Li Mingfang 
Published: April 2012

AbstractIn this study, a metal‐complexing imprinted polymer has been prepared using the complex of Quercetin and Co(II) (Qu‐Co(II)) as template (Quercetin is a kind of flavonoid, which is a class of important active ingredients of Chinese herbs.). The polymers were synthesized in the mixed solution of methanol and tetrahydrofuran by photo‐ and thermal‐initiated polymerization, respectively. The complex ratio between Qu and Co(II), as well as the ternary complexation of Qu, Co(II), and acrylamide, was assessed in differential UV absorption spectrometry. Fourier transform infrared spectra (FTIR) were useful to verify whether the polymers prepared in two ways had the same molecular structure. The effect of initiation mode was studied by the transmission electron microscopy (TEM) and equilibrium binding experiments. Isothermal adsorption and selectivity experiments showed that molecularly imprinted polymers exhibited high affinity and specific recognition for Qu by introducing cobalt ion. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Reversible immobilization of glycoamylase by a variety of Cu2+‐chelated membranes
Authors: Baydemir Gözde , Derazshamshir Ali , Andaç Müge , Andaç Cenk , Denizli Adil 
Published: April 2012

AbstractGlycoamylase (AMG) is an γ‐amylase enzyme which catalyzes the breakdown of large α(1,4)‐linked malto‐oligosaccharides to glucose. It is an extracellular enzyme and is excreted to the culture medium. In this study, AMG was immobilized on a variety of metal affinity membranes, which were prepared by chelating Cu2+ ions onto poly(hydroxyethyl methacrylate) (PHEMA) using N‐methacryloyl‐(L)‐histidine methyl ester (MAH), N‐methacryloyl‐(L)‐cysteine methyl ester (MAC), and N‐methacryloyl‐(L)‐phenylalanine methyl ester (MAPA) as metal‐chelating comonomers for reversible immobilization of AMG. The PHEMAH, PHEMAC, PHEMAPA membranes were synthesized by UV‐initiated photo‐polymerization and Cu2+ ions were chelated on the membrane surfaces. Cu2+‐chelated membranes were characterized by swelling tests, SEM, contact angle measurements, elemental analysis, and FTIR. AMG immobilization on the Cu2+‐chelated membranes was performed by using aqueous solutions of different amounts of AMG at different pH values and Cu2+ loadings. Durability tests concerning desorption of AMG and reusability of the Cu2+‐chelated membranes yielded acceptable results. It was computationally determined that AMG possesses four likely Cu2+/Zn2+ binding sites, away from the catalytic site, to which the metal‐chelated membranes can be efficiently used. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
The order addition effect of carbon black/graphite on the electrical properties of rubber composites
Authors: Mansour S. A. , El‐Salam M. A. , Moharram A. H. , Hussein M. , Al‐Agel Faisal A. M. 
Published: April 2012

AbstractAcrylonitrile‐butadiene rubber (NBR) filled with two types of fillers [high abrasion furnace carbon black (C), and graphite (G)] is made to find out the effect of order addition of C and G on the electrical conductivity of the composites. The temperature and frequency dependence of the (dc and ac) conductivity and dielectric constants have been measured. The values of the thermal expansion and thermal conduction coefficient of NBR rubber lead to the difference in I–V characteristics between CB‐ and G‐NBR rubber composites during the measurement. When graphite is first added to NBR, the electrical conductivity of (GC20‐20) matrix is larger than that of the (CG20‐20) matrix, whereas the carbon black is added first. At low temperature (T < 90°C), the higher values of the dielectric constant (ε′) for the sample GC20‐20 compared with that of the CG20‐20 sample is due to the conducting nature and structure of graphite, whereas the carbon shows less crystallinity and conductivity than graphite. Opposite behavior is noticed at temperature higher than 90°C. The dc conductivity of all composites increases with increasing temperature exhibiting a positive temperature coefficient of conductivity (PTCσ). The conductivity at high temperatures region is controlled by the thermal excitation transport mechanism, whereas at low temperatures region is dominated by tunneling process. The increase in the value of dielectric constant (ε′) with temperatures for the sample GC20‐20 compared with the sample CG20‐20 is due to the conducting nature and structure of graphite, and the carbon less crystalline than the graphite. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Production and characterization of polycaprolactone nanofibers via forcespinning™ technology
Authors: McEachin Zachary , Lozano Karen 
Published: April 2012

AbstractAmong the myriad of methods for polymer nanofiber production, there are only a few methods that can produce submicron range fibers in bulk from melt or solution samples. The Forcespinning™ method allows a substantial increase in sample yield while simultaneously maintaining the integrity of uniform fibers in the nanometer range. The high production yield of such a method greatly reduces the time needed to produce bulk quantities of fibers which may be critical in many fields of research and industry, in particularly in fields relating to biopolymers. The aim of this study was to use this method to form nonwoven mats of polycaprolactone (PCL) nanofibers and to quantitatively analyze the production and characterization of the produced fibers. The bulk PCL was dissolved in dichloromethane and the solutions were forcespun at varying speeds ranging from 3000 to 9000 rpm. It was observed that fiber diameter decreased with increasing rotational speed. The average fiber diameter at 9000 rpm was 220 nm with a standard deviation of ±98 nm. The morphology and degree of crystallinity were characterized by scanning electron microscopy, differential scanning calorimetry, and X‐ray diffraction. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Polyelectrolyte complex nanoparticles for protection and delayed release of enzymes in alkaline pH and at elevated temperature during hydraulic fracturing of oil wells
Authors: Barati Reza , Johnson Stephen J. , McCool Stan , Green Don W. , Willhite G. Paul , Liang Jenn‐Tai 
Published: April 2012

AbstractPolyethylenimine‐dextran sulfate polyelectrolyte complexes (PECs) were used to entrap two enzymes used to degrade polymer gels following hydraulic fracturing of oil wells to obtain delayed release and to protect the enzyme from harsh conditions. Degradation, as revealed by reduction in viscoelastic moduli, of borate‐crosslinked hydroxypropyl guar gel by commercial enzyme loaded in polyelectrolyte nanoparticles was delayed up to 11 h, compared with about 3 h for equivalent systems where the enzyme mixture was not entrapped. PEC nanoparticles also protected both enzymes from denaturation at elevated temperature and pH. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Solid‐state synthesis and characterization of polyaniline/nano‐TiO2composite
Authors: Abdiryim Tursun , Ubul Aminam , Jamal Ruxangul , Tian Yuchuan , Awut Tunsagul , Nurulla Ismayil 
Published: April 2012

AbstractPolyaniline/nano‐TiO2composites with the content of nano‐TiO2varying from 6.2 wt % to 24.1 wt % were prepared by using solid‐state synthesis method at room temperature. The structure and morphology of the composites were characterized by the Fourier transform infrared (FTIR) spectra, ultraviolet‐visible (UV–vis) absorption spectra, X‐ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The electrochemical performances of the composites were investigated by galvanostatic charge–discharge measurement, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The results from FTIR and UV–vis spectra showed that the composites displayed higher oxidation and doping degree than pure PANI. The XRD and morphological studies revealed that the inclusion of nano‐TiO2particles hampered the crystallization of PANI chains in composites, and the composites exhibited mixed particles from free PANI particles and the nano‐TiO2entrapped PANI particles. The galvanostatic charge–discharge measurements indicated that the PANI/nano‐TiO2composites had higher specific capacitances than PANI. The composite with 6.2 wt % TiO2had the highest specific capacitance among the composites. The further electrochemical tests on the composite electrode with 6.2 wt % TiO2showed that the composite displayed an ideal capacitive behavior and good rate ability. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Structural changes as a result of processing in thermoplastic bloodmeal
Authors: Verbeek Casparus J. R. , van den Berg Lisa E. 
Published: April 2012

AbstractBloodmeal (BM) can be thermoplastically processed resulting in a material with good mechanical properties by using a correct combination of additives. In this article, combinations of water, sodium sulfite (SS), sodium dodecyl sulfate (SDS), and urea were compounded with BM, and water absorption, solubility, thermal stability, and protein secondary structure were assessed. Thermal stability of processed plastics was reduced when using 2 or 3 pphbm (parts per hundred parts BM) SS and 20 pphbm urea, mostly indicative of a reduction in covalent crosslinking. SS was required for chain mobility during processing, however, without sufficient plasticization degradation will occur instead of melt formation. SDS further improved processability and consolidation leading to increased water absorption and solubility, indicative of a reduction in chain interactions. It was found that BM proteins are highly denatured and thermoplastic processing reduced ordered structures further. Additional minor structural changes occurred as a result of reduced covalent and noncovalent interactions after processing. It was concluded that the increase in water absorption and solubility was due to changes in intermolecular and intramolecular interactions, rather than substantial structural changes. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis of poly(lactic acid‐co‐menthol) via direct melt polycondensation and its characterization
Authors: Mao Chao‐Xu , Luo Shi‐He , Wang Qun‐Fang , Xiong Jin‐Feng , Wang Zhao‐Yang 
Published: April 2012

AbstractDirectly starting from D,L‐lactic acid (LA) and L‐menthol, poly(lactic acid‐co‐menthol) (PLAM) as potential solid mint flavor was synthesized via melt polycondensation. The synthetic conditions, including type and dosage of catalyst, temperature and time of copolymerization, were discussed. The structure and properties of the copolymer were systematically characterized with FTIR, 1H‐NMR, GPC, DSC, TG, and XRD. The influences of molar feed ratios on the properties of PLAM were also discussed. The copolymer PLAM with the biggest Mw of 11,600 Da was obtained. The Tg of PLAM is lower than the Tg of homopolymer poly(D,L‐lactic acid) (PDLLA), and all copolymers have higher thermal decomposition temperature. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
The effects of long‐term exposure to extremely low‐frequency magnetic fields on bone formation in ovariectomized rats
Authors: Celik Mustafa S. , Gur Ali , Akdağ Zulkuf , Akpolat Veysi , Guven Kemal , Celik Yusuf , Sarac Aysegul J. , Otçu Selcuk 
Published: April 2012

AbstractThe effects of long‐term extremely low‐frequency magnetic field (ELF‐MF) exposure on bone formation and biochemical markers were investigated in ovariectomized rats. Sixty mature female Sprague–Dawley rats were randomly divided into four different groups (n = 15): (i) unexposed control (CTL); (ii) ovariectomized only (OVX); (iii) non‐ovariectomized, exposed (SHAM + ELF‐MF); and (iv) ovariectomized, exposed (OVX + ELF‐MF). The third and fourth groups were exposed to 1.5 mT ELF‐MF for 4 h a day for 6 months. Bone mineral density (BMD) was determined using dual energy X‐ray absorption (DEXA) measurements. The formation and resorption of bone were evaluated using bone‐specific alkaline phosphatase (BAP), osteocalcin, osteoprotogerin, and N‐telopeptide. After 6 months of ELF‐MF therapy, BMD values were significantly lower in the OVX group and higher in the OVX + ELF‐MF and SHAM + ELF‐MF groups than they were before therapy (P < 0.001). Although there was no significant difference in BMD values among the groups before therapy, the BMD values increased significantly after 6 months in the OVX + ELF‐MF and SHAM + ELF‐MF groups and were reduced in the OVX group compared to the CTL group (P < 0.001). The concentrations of BAP, osteocalcin, osteoprotogerin, and N‐telopeptide in the three experimental groups also changed in a significant way compared to the CTL group. The results of the present study suggest that osteoporosis can be inhibited by ELF‐MF stimulation treatments. It was also concluded that ELF‐MF may be useful in the prevention of osteoporosis in ovariectomized rats. Bioelectromagnetics 33:543–549, 2012. © 2012 Wiley Periodicals, Inc.