bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tuning of heavy metal removal efficiency from water via micro algae/hydrogel composites
Authors: Aydınoğlu Demet , Şen Sinan , Helvacıoğlu Ekmel , Nugay Turgut , Nugay Nihan 
Published: May 2014

Abstract A series of micro algea-based hydrogel composites were prepared from polyacrylamide and Spirulina (PAAm-sp). Free radical polymerization of acrylamide (AAm) in the presence of N,N-methylene bis-acrylamide (BAAm), as a crosslinker, and Spirulina microalgae in different loadings was conducted. Chromium metal adsorption capacity was determined with UV-VIS spectroscopy whereas mechanical performance of the resultant hydrogel composites was followed with uniaxial compression experiments. It has been found that efficiency can be tuned by Spiriluna composition in hydrogel. PAAm hydrogel composite having 0.5 % Spirulina had the maximum compression strength, good swelling in water as well as improved thermal stability due to the special and beneficial ‘fishnet morphology” observed via scanning electron microscopy (SEM). The observed high performance of this composition is proved to be due to this morphology where all potential binding sites are under receptive position for metal adsorption. Spirulina by itself in water can remove only about 2 % of its weight of Cr+3 ion, however in the hydrogel structure this removal increases up to 200 % which makes this biotechnological approach superior in the metal removal from the water.
Enantioselective analysis of naproxen using chiral molecular imprinting polymers based thin-layer chromatography
Authors: Huangfu Fengyun , Wang Bing , Shan Juanjuan , Zhang Zhiliang 
Published: May 2014

Abstract This paper describes a rational design and testing of molecularly imprinted polymers (MIPs) as chiral stationary phases of thin-layer chromatography (TLC) for enantiomeric purity of naproxen. Using D-naproxen as template, MIPs with particle size between 10~90 μm were prepared by precipitation polymerization in acetonitrile/methanol mixed solvent. The interactions between functional monomers and template were verified by UV absorption spectrometry. The morphology, particle size distribution and specific surface area of MIPs were also observed by scanning electron microscopy, particle size distribution meter and liquid nitrogen adsorption instrument, respectively. Binding capacities of MIPs had been studied by equilibrium binding assay. Preparation conditions of TLC and impact of acetic acid content on the separation of enantiomers were investigated. The results indicated that when acetic acid content was 4%, the racemates of templates were completely separated, and the chiral separation factor α was 1.58.
Controlled release of Capreomycin sulfate from pHresponsive nanocapsules
Authors: Loiko Olessya P. , Herk Alex M. van , Ali Syed I. , Burkeev Meiram Zh. , Tazhbayev Yerkeblan M. , Zhaparova Lyazzat Zh. 
Published: May 2014

Abstract The synthesis of polymeric nanocapsules loaded with the antituberculosis drug Capreomycin sulphate is presented in this work. The pHresponsive polymeric nanocapsules were successfully synthesized using the RAFT-based vesicle templating approach in the presence of Capreomycin sulphate. Anionic small polyelectrolytes comprising randomly distributed butyl acrylate and acrylic acid units were adsorbed on cationic vesicles of dimethyldioctadecyl ammonium bromide (DODAB). N,N-(dimethylamino)ethyl methacrylate (DMAEMA) and methyl methacrylate (MMA) or tertiary butyl methacrylate (tBMA) and MMA were used for the formation of the polymeric shells. Subsequently the tBMA was hydrolyzed to obtain negatively charged nanocapsules. The nanocapsule morphology for both approaches was characterized by DLS and TEM. The most stable hollow latex particles were obtained with the monomer composition of DMAEMA:MMA = 1:1. These nanocapsules were found to be colloidally stable and pH-responsive. The entrapment efficiency of drug determined by UV-Vis-spectroscopy was 70 %. The drug release rate from nanocapsules at pH 6.5 was found to be relatively fast (substantial release within one hour already), however we believe slower release can be achieved by using a thicker polymer shell.
Rheological measurement of molecular weight distribution of polymers
Authors: Khak Maryam , Ramazani Ahmad S. A. 
Published: May 2014

Abstract This paper has described a method to obtain the molecular weight distribution (MWD) of polymeric materials from their rheological data. The method has been developed for linear polymers with log normal molecular weight distribution. The rheological data required to obtain the molecular weight distribution are the shear storage modulus,G' (ω) , and shear loss modulus,G" (ω) , extending from the terminal zone to the plateau region. For determining the molecular weight average, the method uses the relationship between stress moduli and relaxation spectrums, with the equation that connects dynamic rheological data with molecular weight distribution, and so it is not necessary to achieve the relaxation spectrums and the molecular weight distribution is obtained directly from dynamic shear experiments and it is one of the main advantageous of the proposed method. Comparison of calculated and experimental data obtained by GPC for five polypropylene samples produced in different conditions show that model can correctly predict molecular weight distribution for these types of polymers.
Chain length distribution and kinetic characteristics of an enzymatically produced polymer
Authors: Mulders K.J.M. , Beeftink H.H. 
Published: May 2014

Abstract Non-processive enzymatic polymerization leads to a distribution of polymer chain lengths. A polymerization model was developed to investigate the relation between the extent of this distribution on one hand, and the polymerization start conditions and reaction kinetics on the other hand. The model describes changes in concentration of chains of length n as the result of two elongation reactions: elongation by monomer addition to length n-1 and elongation by monomer addition to length n. Polymerization reactions were assumed to be zero order in monomer concentration and to obey Michaelis-Menten kinetics with respect to polymer concentrations. In addition, the amount of enzyme available for each individual reaction (n → n+1) is assumed to be proportional to the concentration of polymer substrate of length n. The development of the shape of the chain length distribution was found to be independent of the value of the overall reaction rate constant; only the rate at which these shapes developed was influenced by the 1st-order rate constant. The value of the Michaelis parameter did affect the form of the chain length distribution curve since it affects the reaction order. An increase in reaction order was found to promote widening of the chain length distribution. Differences in kinetic parameters between the subsequent polymerization reactions, if any, were also found to have a large effect on the development of the chain length distribution. An increase in rate constants with chain length entailed a wider distribution; a more narrow distribution would require a decrease in rate constants with chain length.
Hydrogen effects in the polymerization of propylene with C2 symmetric metallocene catalysts
Authors: Amer Ismael , Reenen Albert van 
Published: May 2014

Abstract Propylene was polymerized with two C2 symmetric metallocene catalysts, ethylene bis(indenyl)zirconium dichloride and dimethylsilyl bis(2-methylbenz( e) indenyl) zirconium dichloride, in the presence of increasing amounts of hydrogen. The hydrogen influenced the molecular weight significantly, as was expected. The degree of isotacticity of the polypropylene was influenced by the level of hydrogen added during polymerization, and the amount and type of stereoerrors as determined by 13C NMR increased as hydrogen levels were increased. Results indicated that efficiency of enantiomorphic site control is dependent on the length of the growing polymer chain during polymerization.
Encapsulation of human serum albumin in submicrometer magnetic poly(lactide-co-glycolide) particles as a model system for targeted drug delivery
Authors: Shubhra Quazi T.H. , Macková Hana , Horák Daniel , Fodor-Kardos Andrea , Tóth Judit , Gyenis János , Feczkó Tivadar 
Published: May 2014

Abstract Two types of iron oxide nanoparticles were synthesized by coprecipitation of Fe(II) and Fe(III) chlorides: water-dispersible γ-Fe2O3 and organic solvent-dispersible oleic acid-coated Fe3O4 particles. The nanoparticles, together with human serum albumin (HSA) serving as a model for a protein-type drug, were then incorporated in poly(lactide-co-glycolide) (PLGA) particles using double emulsion solvent evaporation technique. Morphology, size and particle size distribution of the resulting particles was analyzed by electron microscopy and dynamic light scattering. Iron oxide and HSA encapsulating efficiency was determined by Prussian Blue staining and micro-BCA assay, respectively.
Patriarchy and New Comedy in Ancient Athens and Rome: Revisiting Northrop Frye's “Mythos of Spring: Comedy”
Authors: Caron James E. 
Published: May 2014

AbstractFew theoretical statements about comic drama and fiction can match the influence of Northrop Frye's essay, “Mythos of Spring: Comedy.” Particularly for scholars interested not only in classic comic literary forms such as stage comedy, but also in the popular forms of contemporary films as well as television sitcoms, Frye's theory continues to be useful for understanding basic structures within large quantities of examples. In this essay, I challenge Frye's model for comic art. Although a quasi-Oedipal plot dominates extant New Comedy, the model suppresses the fact that it is only one significant plot among others capable of generating variations. More importantly, when one examines plays structured by the quasi-Oedipal plot, Frye's summary – a generational struggle that ends in the son's triumph – misrepresents the material: the son's triumph is not a foregone conclusion. New Comedy's function as the symbolic womb of the Western comic tradition is thus far from unproblematic. My challenge has serious consequences, not just for those critics who have organized their analyses on it, but also for those critics who might theorize about literary and popular art forms, as well as for scholars who would write a history of comic forms in the West.
Kynical dogs and cynical masters: Contemporary satire, politics and truth-telling
Authors: Higgie Rebecca 
Published: May 2014

AbstractThis article proposes that the philosophical techniques found in contemporary satires can be understood using a spectrum that ranges between the cynical and the kynical. Cynicism is the belief that there is no hope for change, that truth is dead, while kynicism – a non-nihilistic form of cynicism – maintains that truth does exist, and is worth saving from political and media manipulations. By exploring the evolution of kynicism, from its origins in ancient Greek philosophy to its presence in contemporary satire, I analyze how
Inter- and intra-observer variability in cervical measurement by ultrasound in the first and second trimesters of pregnancy: does it matter?
Authors: França Cíntia , Carraca Teresa , Monteiro Sofia Bessa , Rodrigues Teresa , Montenegro Nuno , Severo Milton , Matias Alexandra 
Published: May 2014

Abstract

Objectives: The aim of this study was to evaluate the inter- and intra-observer variabilities in the cervical length (CL) measurement by transvaginal ultrasound (TVU) in the first and second trimesters of pregnancy.

Materials and methods: A total of 55 singleton pregnant women were evaluated in the first or second ultrasound. Each patient was blindly evaluated by three of the four observers who performed three measurements each.

Results: In the first and second trimesters, patients were evaluated at 12.3 weeks (mean) and 21.3 weeks (mean), respectively. The intra-class correlation coefficients (ICC) between observers in the first and second trimesters were 0.76 and 0.72, respectively, and the ICCs within observers were 0.889 and 0.899, respectively. In both trimesters, the main source of variance was the patient and the second source of variance was the interaction, Patient×Observer (12.0% and 13.5%, respectively). The observer and measurement explained a small proportion of variance in both trimesters (1.4% and 0.4%, respectively in the 1st trimester, and 3.3% and 0%, respectively in the 2nd trimester). The residual variances were 10.6% and 11.2%, and the standard errors of measurement were 1.78 mm and 1.82 mm for the first and second trimesters, respectively.

Conclusions: TVU is a reliable and reproducible method by which to predict preterm birth in both the first and second trimesters.
Crystal structure of (,2-2,2'-bipyrimidine-κ4N1,N1':N3,N3')bis[iodido (t-butyldiphenylphosphane-κP)copper(I)]dimethylformamide disolvate, C40H44Cu2I2N4P2·2(C3H7NO), C46H58Cu2I2N6O2P2
Authors: Fettouhi Mohammed 
Published: May 2014

AbstractC
Effect of the quenching temperature on the mechanical and thermophysical properties of polycarbonate pigmented with titanium dioxide
Authors: Rouabah Farid , Dadache Derradji , Fois Magali , Haddaoui Nacceredine 
Published: May 2014

Abstract
This work deals with the effect of the quenching temperature on the mechanical and thermophysical properties of polycarbonate (PC) pigmented with titanium dioxide (TiO2). The thermal conductivity, thermal diffusivity, Izod impact strength and density measurements were measured. The thermal conductivity and diffusivity of the composites were measured using a periodic measurement method. It was found that an additional second quenching involved an increase in the value of the Izod impact strength near 35°C and a decrease in the values of the density, the thermal conductivity and the thermal diffusivity. A transition in these properties which is located at around 35°C has also been observed and linked to the β1 relaxation mode of PC.
Preparation and characterization of oxidized starch-graft-poly(styrene-butyl acrylate) latex via emulsion polymerization
Authors: Cheng Shijie , Xu Jun , Wu Yumin 
Published: May 2014

Abstract
Oxidized starch-graft-poly(styrene-butyl acrylate) [OS-g-P(St-BA)] latex was synthesized by the graft copolymerization of OS with St and n-butyl acrylate (BA) via emulsion polymerization. The graft copolymers were characterized by Fourier transform infrared (FT-IR), transmission electronic microscopy (TEM), dynamic light scattering, thermogravimetry (TG), and differential scanning calorimetry (DSC). The effects of the amount of OS, monomers, and initiator on graft copolymerization were investigated. Under the optimal conditions, the percentage of graft (PG), grafting efficiency (GE), and ζ potential could reach 256.5%, 41.7%, and -30.1 mV, respectively. The results indicated that the OS grafted onto particles greatly enhanced the colloidal stability of latex. The thermal stability properties of OS-g-P(St-BA) were also improved by the addition of OS. The OS-g-P(St-BA) latex may be used to partly replace the conventional synthetic latex for paper coating.
Cationic copolymerization of 1,3-pentadiene with α-pinene
Authors: Li Ai-Yuan , Sun Xiang-Dong , Zhang Hui-Bo , Zhang Yong-Chun , Wang Bin , Shi Li-Qin 
Published: May 2014

Abstract
The cationic copolymerization of 1,3-pentadiene (PD) with α-pinene (AP) initiated by aluminum trichloride (AlCl3) was carried out in N-pentane solvent. The effects of the polymerization temperature and the comonomer composition on the yield of the copolymer, softening point, Gardner color scale and number-average molecular weight (Mn) are discussed. The performance of the copolymer was better than that of AP homopolymer (PAP) and PD homopolymer (PPD). The structure of the copolymer was characterized by Fourier transform infrared spectroscopy (FT-IR), 1H-nuclear magnetic resonance (1H-NMR), 13C-NMR, differential scanning calorimetry (DSC) and gel permeation chromatography (GPC). In addition, the reactivity ratios for AP (M1) and PD (M2) determined by the Kelen-Tudos method from low-conversion data are r1=0.58 and r2=5.92, respectively.
X-ray absorption spectroscopy investigations on radioactive matter using MARS beamline at SOLEIL synchrotron
Authors: LLorens Isabelle , Solari Pier Lorenzo , Sitaud Bruno , Bes René , Cammelli Sebastiano , Hermange Hervé , Othmane Guillaume , Safi Sami , Moisy Philippe , Wahu Sandrine , Bresson Carole , Schlegel Michel L. , Menut Denis , Bechade Jean-Luc , Martin Philippe , Hazemann Jean-Louis , Proux Olivier , Den Auwer Christophe 
Published: May 2014

Abstract
The MARS beamline at the SOLEIL synchrotron is dedicated to the characterization of radioactive material samples. One great advantage of the beamline is the possibility to characterize about 380 radionuclides by different X-ray techniques in the same place. This facility is unique in Europe. A wide energy range from around 3.5 keV to 36 keV K-edges from K to Cs, and L3 edges from Cd to Am and beyond can be used. The MARS beamline is optimized for X-ray absorption spectroscopy techniques (XANES/EXAFS), powder diffraction (XRD) but x-ray fluorescence (XRF) analysis, High Energy Resolution Fluorescence Detected -XAS (HERFD-XAS), X-ray Emission (XES) and μ-XAS/XRD are also possible. A description of the beamline as well as its performances are given in a first part. Then some scientific examples of XAS studies from users are presented which cover a wide variety of topics in radiochemistry and nuclear materials.
Identification of a gene regulatory network associated with prion replication
Authors: Marbiah Masue M , Harvey Anna , West Billy T , Louzolo Anais , Banerjee Priya , Alden Jack , Grigoriadis Anita , Hummerich Holger , Kan Ho‐Man , Cai Ying , Bloom George S , Jat Parmjit , Collinge John , Klöhn Peter‐Christian 
Published: May 2014

AbstractPrions consist of aggregates of abnormal conformers of the cellular prion protein (PrPC). They propagate by recruiting host‐encoded PrPC although the critical interacting proteins and the reasons for the differences in susceptibility of distinct cell lines and populations are unknown. We derived a lineage of cell lines with markedly differing susceptibilities, unexplained by PrPC expression differences, to identify such factors. Transcriptome analysis of prion‐resistant revertants, isolated from highly susceptible cells, revealed a gene expression signature associated with susceptibility and modulated by differentiation. Several of these genes encode proteins with a role in extracellular matrix (ECM) remodelling, a compartment in which disease‐related PrP is deposited. Silencing nine of these genes significantly increased susceptibility. Silencing of Papss2 led to undersulphated heparan sulphate and increased PrPC deposition at the ECM, concomitantly with increased prion propagation. Moreover, inhibition of fibronectin 1 binding to integrin α8 by RGD peptide inhibited metalloproteinases (MMP)‐2/9 whilst increasing prion propagation. In summary, we have identified a gene regulatory network associated with prion propagation at the ECM and governed by the cellular differentiation state.
Lower serum osteocalcin is associated with more severe metabolic syndrome in elderly men from the MINOS cohort
Authors: Confavreux Cyrille B , Szulc Pawel , Casey Romain , Varennes Annie , Goudable Joelle , Chapurlat Roland D 
Published: May 2014

BackgroundBone has emerged as an endocrine organ regulating energy metabolism through secretion of osteocalcin. In epidemiological studies, presence of metabolic syndrome (MetS) was associated with lower osteocalcin level.ObjectivesWe evaluated whether osteocalcin level was associated with MetS severity in men and whether it was more strongly associated with MetS compared with N-terminal propeptide of type I procollagen (PINP), bone-specific alkaline phosphatase (BAP), and C-terminal telopeptide of type I collagen (βCTX).MethodsWe included 798 men aged 51–85 years for total osteocalcin measurement. Number of MetS criteria was used to define severity. We used polytomous logistic regression to assess the relationship between MetS severity and osteocalcin level.ResultsThirty percent of men had MetS. In patients with MetS, the higher the number of MetS traits were present, the lower was the average osteocalcin level (0–2 criteria: 551 men: 19.5±6.7 ng/ml, three criteria: 155 men: 19.3±7.4 ng/ml, four criteria: 72 men: 17.3±5.7 ng/ml, and five criteria: 20 men: 15.0±5.1 ng/ml;Pfor trend=0.002).In the polytomous logistic regression model, an increase in osteocalcin level of 10 ng/ml was associated with lower prevalence of severe MetS: three criteria (odds ratio (OR)=0.93 (0.70–1.24)), four criteria (OR=0.54 (0.34–0.84)), and five criteria (OR=0.28 (0.10–0.82)) in comparison with no MetS (Pfor trend=0.008).After adjustment, using stepwise analysis of the polytomous logistic regression model, we observed that osteocalcin, age, and apparent free testosterone entered in the model but not other bone markers (PINP, βCTX, and BAP).ConclusionIn older Caucasian men, total osteocalcin level was associated with MetS severity. Osteocalcin was more strongly associated with MetS severity than other bone turnover markers.
Comparison of universal and targeted screening for thyroid dysfunction in pregnant Egyptian women
Authors: Ahmed Iman Z , Eid Yara M , El Orabi Hussein , Ibrahim Hani Refat 
Published: May 2014

ObjectiveTo compare universal vs targeted screening for thyroid dysfunction and to estimate the prevalence of hypothyroidism in pregnant Egyptian women.Subjects and methodsA total of 168 of pregnant women who attended the outpatient obstetric clinic at Ain Shams University Hospital (Cairo, Egypt) for antenatal care between September 2011 and December 2011 were enrolled. Based on the detailed data collection and results of laboratory testing, they were subdivided into the high- and low-risk group for thyroid disease according to the most recent Endocrine Society clinical practice guidelines, as well as into groups by trimester for application of American Thyroid Association guidelines. The group values were subjected to statistical analysis for estimating the prevalence of clinical and subclinical hypothyroidism and for identifying significant differences.ResultsOf the 168 patients, 104 were classified into the low-risk group and 64 into the high-risk group. Using the trimesteric and normal population cutoff values for thyroid functions, the prevalence of hypothyroidism was found to be 56% (n=94) and 44.6% (n=75) respectively. No statistically significant differences were found between the high- and low-risk group regarding prevalence of either clinical or subclinical hypothyroidism, and no significant differences were found regarding the prevalence of hypothyroidism in the first, second, or third trimester.ConclusionUse of the most recent Endocrine Society clinical practice guidelines led to missed detection of clinical or subclinical hypothyroidism in 34.5% of pregnant women. Universal screening of pregnant women for thyroid dysfunction should thus be adopted throughout Egypt.