bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mild cognitive impairment identified in older individuals with down syndrome by reduced telomere signal numbers and shorter telomeres measured in microns
Authors: Jenkins Edmund C. , Ye Lingling , Velinov Milen , Krinsky‐McHale Sharon J. , Zigman Warren B. , Schupf Nicole , Silverman Wayne P. 
Published: May 2012

AbstractPreviously, we established that short‐term T lymphocyte cultures from people with Down syndrome (DS) and dementia (Alzheimer's disease) had shorter telomeres than did those from age‐ and sex‐matched people with DS only, quantified as significantly reduced numbers of signals of peptide nucleic acid (PNA) telomere probes in whole metaphases [Jenkins et al. (2008); Neurosci Lett 440:340–343] as well as reduced telomere probe light intensity values in interphases [Jenkins et al. (2010); Neurobiol Aging 31:765–771]. We now describe shorter telomere length in adults with DS and mild cognitive impairment (MCI) compared to age‐ and sex‐matched individuals with DS without MCI. Telomere length is quantified by reduced telomere signal numbers and shorter chromosome 1 telomeres measured in micrometers (microns). These findings were in agreement with quantitative light intensity measurements of chromosome 1 and chromosome 21 PNA telomere probes with and without the use of a “normalizing ratio” involving the fluorescence exhibited by a PNA probe for centromere 2, and with the use of light intensity measurements of interphase preparations. Most importantly, the distributions of chromosome 1 telomere lengths (in microns) were completely non‐overlapping for adults with and without MCI, indicating that this measure has great promise as a biomarker for MCI as well as dementia in this population. © 2012 Wiley Periodicals, Inc.
Rheological and mechanical behavior of ethyl vinyl acetate/low density polyethylene blends for injection molding
Authors: Iannaccone Antonio , Amitrano Salvatore , Pantani Roberto 
Published: May 2012

AbstractEthyl vinyl acetate (EVA) is normally injection molded to produce parts with specific properties of flexibility and energy absorption. However, the produced objects often present an excessive flexibility. Furthermore, EVA presents a high viscosity for injection molding technology, and this compels the operator to apply high hydraulic pressures. The addition of PolyEthylene (PE) can provide a higher rigidity to the products, improve the flowability of the melt during processing, and at the same time reduce the cost of the products. In this work, several blends of EVA and low density polyethylene are prepared by melt mixing and injection molded. Rheological, calorimetric, and tensile tests are conducted on the molded specimens with the aim of understanding the performances of the materials also in the view of scrap recycling. On pursuing the mentioned goals, the behavior of the blends in the molten state, during crystallization and in the solid state was analyzed by comparing the experimental data with mixing rules to gather information concerning the morphology of the systems. All the results show that both the melt viscosities of the elastic moduli present significant deviations from the mixing rules, indicating that a phase inversion takes place on increasing the amount of EVA, both in molten and in solid state. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Tracking the fate of seed particles in dispersion polymerization: Preparation and application of fluorescent polymer particles
Authors: Song Zhipeng , Daniels Eric S. , David Sudol E. , Gilchrist James F. , Klein Andrew , El‐Aasser Mohamed S. 
Published: May 2012

AbstractThe mechanism of seeded dispersion polymerization of methyl methacrylate (MMA) was investigated by employing submicron fluorescent polymer particles as seed. These poly(methyl methacrylate) latex particles, containing fluorescent material, were synthesized by a two‐step miniemulsion polymerization process and then applied in the seeded dispersion polymerization of MMA. The seed particles were located by tracking the fluorescent signal in the micron‐size final particles. The analysis of the final particles showed that most of them contained more than two seed particles. On average, there were 3.7 seed particles in each final particle as obtained under the given conditions of the seeded dispersion polymerization. The location of the seed within the particles being well‐separated from each other was considered to indicate that the aggregation of the particles did not occur immediately, but took place after some particle growth had first taken place. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation of regenerated wool keratin films from wool keratin–ionic liquid solutions
Authors: Li Rong , Wang Dong 
Published: May 2012

AbstractThe regenerated wool keratin films were prepared from the wool keratin/ionic liquid solutions through water, methanol and ethanol as coagulation solvents in this article. It could be suggested from the results that [AMIM]+·Cl− ionic liquid has higher solubility for wool keratin fibers than [BMIM]+·Cl− ionic liquid. IR data showed the part of the disulfide bonds was broken during the dissolution. It could be seen from XRD data that the regenerated films exhibited a β‐sheet structure and the disappearance of the α‐helix structure. TGA curves indicated that the thermal stability of regenerated wool keratin films decreased slightly compared to nature wool fibers. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Thermomechanical and water‐responsive shape memory properties of carbon nanotubes‐reinforced hyperbranched polyurethane composites
Authors: Rana Sravendra , Cho Jae Whan , Park Jong‐Shin 
Published: May 2012

AbstractShape memory composites of hyperbranched polyurethane (HBPU) and acid‐treated multi‐walled carbon nanotubes (MWNTs) were prepared using an in situ polymerization method. HBPUs with different hard segments contents were synthesized via the A2 + B3 approach using poly(ethylene glycol) (PEG) as a soft segment, 4,4′‐methylene bis(phenylisocynate), castor oil, and 1,4‐butanediol as hard segment. Compared to HBPU, the HBPU/MWNT composites showed faster shape recovery and double the shape recovery stress in the thermomechanical shape memory test, which was dependent on the MWNTs content and HBPU hard segment content. The water‐responsive shape memory effect of HBPU/MWNT composites was considered to result from the combined contribution of hydrophilic PEG and well dispersed MWNTs in highly branched HBPU molecules. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effect of the unidirectional drawing on the thermal and mechanical properties of PLA films with different L‐isomer content
Authors: Velazquez‐Infante J. C. , Gamez‐Perez J. , Franco‐Urquiza E. A. , Santana O. O. , Carrasco F. , Ll Maspoch M. 
Published: May 2012

AbstractThis work simulates the thermoforming process of two different L‐isomer content PLA grades (95.6 and 98%), studying the influence on the induced morphology and the variation in the thermal and tensile properties. The thermoforming process was simulated with uniaxial tensile tests performed at different temperatures and strain rates, reporting the tensile behavior before, during, and after the test. The resulting structural changes were analyzed by wide‐angle X‐ray scattering and Fourier transformed infrared spectroscopy. Thermal characterization was carried out with differential scanning calorimetry and dynamomechanical thermal analysis. The results showed that, regardless the L‐isomer content, drawing at 70°C produced a stable mesomorphic phase that showed greater tensile properties than the original films. This mesomorphic phase, indeed, could be reordered into a crystalline structure under mild annealing conditions (5 min/75°C), if compared with those needed for similar amorphous PLA specimens (60 min/120°C), thus providing a processing opportunity for obtaining thermally stable PLA products at temperatures above 100°C. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Membranes of poly(phenylene oxide) and its copolymers: Synthesis, characterization, and application in recovery of propylene from a refinery off‐gas mixture
Authors: Gajbhiye Susheela Bai 
Published: May 2012

AbstractCopolymers of 2,6‐dimethyl‐phenol (DMP) and 2,6‐diphenyl‐phenol (DPP) were synthesized in the initial molar ratio of 100 : 0 (S(PPO)), 90 : 10 (Co‐A), 75 : 25 (Co‐B), 65 : 35 (Co‐C), and 0 : 100 (PDPPO). Dense membranes of 30 μm thickness were tested for single gas permeation and binary mixture separation of 55:45 (in mol %) propylene‐propane at 30°C ± 2°C. Their performance was ultimately examined in the enrichment of propylene from a refinery off‐gas mixture (ROG or also called as absorber tail gas, ATG) having the same composition as the ATG of a fluid catalytic cracking (FCC) unit of HPCL refinery, Visakhapatnam. The mixture contains C1–C5 hydrocarbons and nonhydrocarbons such as CO, CO2, H2, and N2. A detailed permeation study of the hydrocarbon part of ATG revealed that using S(PPO) and Co‐A, propylene could be upgraded from ∼ 29 mol % (on nonhydrocarbon free basis) to 62.2 and 74.4 mol % with propylene/propane selectivity ratio of 5.99 and 8.45, respectively. The structure of polymers was characterized by Fourier transform infrared (FTIR), proton nuclear magnetic resonance (Proton NMR), viscosity measurements. Scanning electron microscope (SEM), wide angle X‐ray diffraction (WAXD), density and fractional free volume measurements were used for studying membrane morphology. Dynamic mechanical thermal analyzer (DMTA) and tensile testing were carried to find glass transition temperature (Tg) and mechanical properties. The relative differences observed in gas permeation of these polymers were correlated with the physical properties measured. S(PPO) and Co‐A were identified as potential materials for the upgradation of propylene from refinery off‐gas streams. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Fabrication of polymethyl methacrylate/polysulfone/nanoceramic composites for orthopedic applications
Authors: Bhat Kalambettu Aravind , Leo Prakash P. , Manoharan Niranjanaa , Lakshmibai A. , Sangeetha Dharmalingam 
Published: May 2012

AbstractWe report the fabrication of polymethyl methacrylate/polysulfone/nanohydroxyapatite (PMMA/PSu/nHA) and PMMA/PSu/nanotitania (PMMA/PSu/nTiO2) composites using N′N′‐methylene‐bis‐acrylamide (MBA) to crosslink PMMA and act as a blending agent. The composite was made porous by incorporating polyethylene glycol as the pore‐forming agent. The blend between PMMA and PSu was confirmed using Fourier transform infrared spectroscopy and thermogravimetric analysis (TGA). The surface morphology of the composites analyzed using scanning electronic microscopy (SEM) revealed the porous structure and the wide distribution of the fillers that were found to aggregate at higher concentrations. The maximum tensile strength observed for composites was with 5% nHA (23 MPa) and 7.5% TiO2 (30 MPa). The TGA of the composites showed better thermal stability with increase in the filler concentrations. The X‐ray diffraction analysis showed that appearance of new peaks in the blend polymers indicating a strong interaction between PMMA and PSu. The surface of the composites was coated with amoxicillin and its efficiency was examined by the Zone of Inhibition test using Streptococcus mutans. The bioactivity of the composites was evaluated by immersing them in simulated body fluid and examining their surface for the formation of calcium‐phosphate layer using SEM and EDAX. Bioactivity was found to increase with increase in filler content. The in vitro biocompatibility of the composites, evaluated using monkey kidney epithelial cells by MTT assay showed that the composites containing nHA showed better cell viability than the composites with nTiO2. The study showed that the composites with nTiO2 exhibited better strength when compared with nHA composites while the later exhibited better biocompatibility. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
1,3‐bis(benzoxazine) from cashew nut shell oil and diaminodiphenyl methane and its composites with wood flour
Authors: Agag Tarek , An Si Young , Ishida Hatsuo 
Published: May 2012

AbstractCashew nut oil‐based benzoxazine monomer has been synthesized applying solvent‐less method through the Mannich reaction of cashew nut shell oil as phenol, amine, and formaldehyde. A difunctional 1,3‐benzoxazine is synthesized using diaminodiphenyl methane as the amine component. 1H and 13C‐nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy are used to characterize the structure of the monomers. Wood flour is used to prepare composites, making both reinforcement and matrix resin the materials derived from renewable resources. Observation of catalytic effects on DSC exothermic temperature and crosslink density by the added wood flour is discussed. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Fire resistance of hybrid building materials
Authors: Papanicolaou G. C. , Lagas G. , Mimigiannis N. I. 
Published: May 2012

AbstractIn this work, an experimental procedure was conducted to investigate the effect of weight content of short E‐glass fibers on the degradation of flexural properties of a hybrid building material, when exposed to a direct gas (propane/butane) flame for varying time intervals. This experimental procedure is aiming on one hand to define the role that E‐glass fibers play on the degradation of the flexural properties of the materials tested, as well as to provide a sufficient quantity of experimental data which will allow to quantitatively predict the observed degradation of the aforementioned properties due to exposure to direct gas flame using the Residual Property Model (R.P.M.) developed by the first author and already successfully applied to a number of different materials subjected to a combination of different damage sources. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Adsorption and drug release based on β‐cyclodextrin‐grafted hydroxyapatite composite
Authors: Tang Weili , Zhao Jingchan , Sha Bijing , Liu Hong 
Published: May 2012

AbstractIn this study, β‐cyclodextrin (β‐CD) was covalently grafted on hydroxyapatite (HA) using a coupling agent to improve the drug loading capacity and prolong the drug release. The binding of β‐CD on the HA surface was confirmed by Fourier transformation infrared spectroscopy, thermal gravimetric analysis, and X‐ray powder diffraction. The adsorption capacity of ofloxacin on β‐CD‐grafted hydroxyapatite (β‐CD‐g‐HA) composite was found to be 30 mg g−1 at 37°C and 24 h. The adsorption process is spontaneous, given the negative values of free energy change. Compared with the release of ofloxacin loaded on HA, the release of ofloxacin loaded on β‐CD‐g‐HA was slowed down 28% and 21% in pH 2.0 and pH 7.4 buffer media at 2 h, respectively. Biocompatibility of β‐CD‐g‐HA was assessed by MTT assay, and the result showed that it had no cytotoxicity. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Kinetics of glycolysis of poly(ethylene terephthalate) under microwave irradiation
Authors: Chen Feifei , Wang Guanghui , Shi Chuan , Zhang Yichen , Zhang Long , Li Wei , Yang Feng 
Published: May 2012

AbstractThe glycolysis of poly(ethylene terephthalate) (PET) was carried out using excess ethylene glycol (EG) in the presence of zinc acetate as catalysts under microwave irradiation. The effects of particle size, microwave power, the weight ratio of EG to PET, the weight ratio of catalyst to PET, reaction temperature and stirring speed on the yield of bis(hydroxyethyl terephthalate)(BHET) were investigated. The experimental results indicated that the glycolysis rate was significantly influenced by stirring speed and initial particle size. The optimal parameters of glycolysis reactions were the weight ratio of catalyst to PET of 1%, the weight ratio of EG to PET of 5, 500 W and 196°C, the yield of BHET reached to 78% at only 35 min. The glycolysis products were analyzed and identified by FTIR, differential scanning calorimetry, and elemental analysis. The kinetics of glycolysis of PET under microwave irradiation could be interpreted by the shrinking core model of the film diffusion control. The apparent activation energy was evaluated using the Arrhenius equation and it was found to be 36.5 KJ/mol, which was lower compared to the same process using conventional heating. The experimental results also showed that the reaction time was significantly decreased under microwave irradiation as compared with it by conventional heating. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Electric‐field‐induced aggregation of polymeric micelles to construct secondary assembly films
Authors: Liu Ren , Luo Jing , Tao Youhua , Zhu Ye , Chen Mingqing , Liu Xiaoya 
Published: May 2012

AbstractA new amphiphilic quaternary random ionomer (PIDHES) was used to construct self‐assembly films. PIDHES was prepared by a selective ionization of quaternary random copolymer, poly(N,N‐domethyl amimethyl methartylate‐co‐2‐hydroxypropyl methacrylate‐co‐2‐ethylhexyl acrylate‐co‐styrene) precursor, which was synthesized by free radical copolymerization of commercial hydrophilic monomers N, N‐domethyl amimethyl methartylate and 2‐hydroxypropyl methacrylate and hydrophobic monomers 2‐ethylhexyl acrylate and styrene PIDHES could self‐assemble into polymer micelles in water, which underwent orientated deposition in the electric field and ultimately produced secondary assembly films. Scanning electron microscopy studies showed that the resultant PIDHES secondary assembly film was smooth and compact. Moreover, it was found that PIDHES micelles concentration and electric‐field‐induced time had a strong influence on the morphologies of the resultant secondary assembly film. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis of high‐solid content sulfonate‐type polyurethane dispersion by pellet process
Authors: He Lina , Sun Dongcheng 
Published: May 2012

AbstractA novel method to prepare polyurethane dispersions (PUDs) is introduced in this article. Water dispersible polyurethane ionomer pellets were synthesized without solvent; these pellets were then dissolved in acetone and dispersed in water. Then PUDs were obtained after acetone was distilled off. Polyurethane ionomers were synthesized from polyether diol containing sulfonate as hydrophilic monomer and poly(1,4‐butylene adipate glycol) with an average molecular weight of 3000 as soft segments, isophorone diisocyanate and 1,4‐butanediol as hard segments, and dibutyltin dilaurate as catalyst. The properties of PUDs were measured by Laser particle size analyzer, Brookfield viscosity, and TEM analysis. High‐solid content and low viscosity PUDs were obtained. Meanwhile, PUDs exhibited excellent stability and polydispersity according to the above analysis. Tensile tests and dynamic mechanical analysis showed good mechanical and thermodynamic properties of PUD films. Some typical characteristics of crystalline polymers were revealed in the tensile stress–strain curves of PUD films. Peel strength test (PVC/PVC) yielded a maximum initial peel strength value of 6 N/mm and T‐peel strength value of 10 N/mm. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis and Spectral Characterization of New Bis(2‐(pyrimidin‐2‐yl)ethoxy)alkanes and Their Pharmacological Activity
Authors: Rani Vangavaragu Jhansi , Aminedi Raghavendra , Polireddy Kishore , Jagadeeswarareddy Kanala 
Published: May 2012

AbstractThe pyrimidine nucleus is an important component of nucleic acids (DNA and RNA) and vitamins (B2 and folic acid). It is evident from the literature that pyrimidine derivatives possess a wide spectrum of biological activities such as antioxidant, anticancer, antibacterial, and anti‐inflammatory activities. On the basis of diverse biological activities, we attempted to synthesize a series of novel bis(2‐(pyrimidin‐2‐yl)ethoxy)alkanes 5a–j in four steps with good yields. 2‐Chloropyrimidine (1) was reacted with diethyl malonate in the presence of sodium hydride in dry dimethyl formamide to yield the intermediate diethyl 2‐(pyrimidin‐2‐yl)malonate (2), which on further reaction with sodium chloride and dimethyl sulfoxide yielded ethyl 2‐(pyrimidin‐2‐yl)ethanoate (3). Reduction with sodium borohydride (NaBH4) resulted in the formation of 2‐(pyrimidin‐2‐yl)ethanol (4). This was further reacted with various dibromoalkanes to obtain the title compounds 5a–j. In this current study, we evaluated the antioxidant properties of the title compounds using four in vitro test systems: the 2,2‐diphenyl‐2‐picrylhydrazyl radical‐, superoxide radical‐, and hydroxyl radical‐scavenging assays, and the anti‐lipid peroxidation activity test. The title compounds showed promising antioxidant activity when compared to butylated hydroxytoluene. The potency of their antioxidant activity was mainly influenced by the alkyl fragment attached to 2‐(pyrimidin‐2‐yl)ethanol. The ethyl and butyl fragments linked to oxygen led to increased antioxidant activity of the title compounds (i.e., 5b and 5d) in all our in vitro assays.
Synthesis and Bioevaluation of Diphyllin Glycosides as Novel Anticancer Agents
Authors: Zhao Yu , Ni Chunyan , Zhang Yuting , Zhu Li 
Published: May 2012

AbstractA series of diphyllin glycosides were synthesized from diphyllin by phase transfer catalysis glycosylation, deprotection, and etherification, and the structures were established by 1H NMR, 13C NMR, and HRMS. These glycosides were evaluated for their in vitro cytotoxicity against HCT‐116, A549, and A549T cancer cell lines by MTT assay, and most of them were cytotoxic at submicromolar concentrations. They were also effective against the paclitaxel‐resistant cell line A549T. The kDNA decatenation assay indicated that most of these compounds inhibited topoisomerase IIα‐mediated kDNA decatenation. In addition, the in vitro tubulin polymerization study showed that compounds 5 and 6 had antimicrotubule activity with a paclitaxel‐like mode of action. Taken together, these results suggest that these diphyllin glycosides act on both TopoII and tubulin.
Identification of leukemia stem cells in acute myeloid leukemia and their clinical relevance
Authors: Hoang Van Thanh , Zepeda‐Moreno Abraham , Ho Anthony D. 
Published: May 2012

AbstractAcute myeloid leukemia (AML) is considered to be a disease of stem cells. A rare defective stem cell population is purported to drive tumor growth. Similarly to their normal counterparts, leukemic stem cells (LSC) divide extreme slowly. This may explain the ineffectiveness of conventional chemotherapy in combatting this disease. Novel treatment strategies aimed at disrupting the binding of LSC to stem cell niches within the bone marrow might render the LSC vulnerable to chemotherapy and thus improving treatment outcome. This review focuses on the detection of LSC, our current knowledge about their cellular and molecular biology, and LSC interaction with the niche. Finally, we discuss the clinical relevance of LSC and prospective targeted treatment strategies for patients with AML.
Programmable genetic switches to control transcriptional machinery of pluripotency
Authors: Pandian Ganesh N. , Sugiyama Hiroshi 
Published: May 2012

AbstractTranscriptional activators play a central role in the regulation of gene expression and have the ability to manipulate the specification of cell fate. Pluripotency is a transient state where a cell has the potential to develop into more than one type of mature cell. The induction of pluripotency in differentiated cells requires extensive chromatin reorganization regulated by core transcriptional machinery. Several small molecules have been shown to enhance the efficiency of somatic cell reprogramming into pluripotent stem cells. However, entirely chemical‐based reprogramming remains elusive. Recently, we reported that selective DNA‐binding hairpin pyrrole‐imidazole polyamides conjugated with histone deacetylase inhibitor could mimic natural transcription factors and epigenetically activate certain pluripotency‐associated genes. Here, we review the need to develop selective chromatin‐modifying transcriptional activators for somatic genome reprogramming.