bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of copolymerizing fluorine‐bearing monomers on the relationship among internal structure, gas permeability, and transparency in copolymer networks composed of methacrylates and siloxane macromers
Authors: Yokota Mitsuru , Ajiro Hiroharu , Akashi Mitsuru 
Published: April 2012

AbstractTo clarify the effect of the type of acrylic monomer and the molecular weight (Mn) of polydimethylsiloxane (PDMS) on the relationship among the internal structure, oxygen permeability coefficient [P(O2)] and transparency, crosslinked copolymers were prepared with two different acrylic monomers : methyl methacrylate (MMA) and trifluoroethyl methacrylate (TFEMA). PDMS macromers with Mn of 1700, 3300, 4700, and 7800 g/mol were used. DSC measurements suggested that all constituent phases were insoluble with each other. The Mn of PDMS affected both the light transmittance and P(O2). The relationship between the Mn and P(O2) over the low Mn range (1700 and 3300 g/mol), and the calculated PDMS domain size ratio, were found to support the [Mn]2/3 rule into the crosslinked copolymer. Furthermore, a 3300 g/mol Mn copolymer became transparent when the amount of PDMS was greater than PMMA. In addition, copolymerization with TFEMA drastically affected those properties, and this effect was much greater than the effect of the PDMS Mn. To clarify the mechanism of P(O2) improvement induced by TFEMA copolymerization, calculations on the relationship among the P(O2), PDMS volume fraction, and morphology model were performed, and some properties such as solubility parameters should play important roles. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Triazine‐containing benzoxazine and its high‐performance polymer
Authors: Wang Dengxia , Li Bin , Zhang Yaoheng , Lu Zaijun 
Published: April 2012

AbstractA new synthetic route was designed to significantly increase the content of triazine structure in benzoxazine resin. 2,4,6‐Tri(4‐hydroxylphenyl)‐13,5‐s‐triazine (TP) was synthesized by cyclotrimerization of 4‐cyanolphenol and then benzoxazine monomer‐containing triazine [2,4,6‐tri(3‐phenyl‐3,4‐dihydro‐2H‐1,3‐benzoxazin‐6‐yl)‐1,3,5‐s‐triazine (BZ‐ta)] was synthesized via Mannich reaction from TP. Finally, the cross‐linked polymer P(BZ‐ta) was produced by thermal polymerization of BZ‐ta. BZ‐ta was characterized by nuclear magnetic resonance spectroscopy (NMR), fourier transform infrared spectroscopy (FTIR), mass spectrum, elemental analysis, and viscosity measurement. Curing behavior of BZ‐ta was studied by differential scanning calorimetry, FTIR, and gel permeation chromatography. The structure and properties of P(BZ‐ta) were investigated by powder X‐ray diffraction, dynamic mechanical analysis, and thermogravimetric analysis. The results showed that the P(BZ‐ta) had high glass temperature (Tg = 322°C), excellent thermal oxidation stability (5 and 10% weight loss temperatures in air up to 403 and 453°C, respectively), high char yield (64%, 800°C in nitrogen), and high flame‐retardance (limiting oxygen index, 39.7). © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Physical properties and antimicrobial activity of chilled meat pads containing sodium carboxymethyl cellulose
Authors: Wang Shishuai , Kuang Xuan , Li Bin , Wu Xiaofang , Huang Ting 
Published: April 2012

AbstractAn improved chilled meat pad consisting of nonwoven fabric containing essential oils or active powders, coated by a sodium carboxymethylcellulose (CMCNa) layer was prepared successfully. In the formation of CMCNa film, effects of four acids and pH were examined to obtain optimal results in terms of water, saline, and simulative blood sorption. Fourier Transform Infrared spectroscopy, scanning electron microscopy, and differential scanning calorimetry were used to evaluate the CMCNa film. Also, antimicrobial activities were examined in relation to water loss, aerobic bacterial count, and pH. When the pH value was 4.6 adjusted by citric acid, CMCNa film had the largest absorbent capacity. In the first 6 days, pads with essential oils were superior to pads with powders but inhibiting effect decreased with essential oil releasing. The pad with clove powder gained the best inhibiting effect and could extend the shelf life of chilled meat to 10 days. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation of polystyrene/MMT nanocomposite through in situ RAFT polymerization by new chain transfer agent derived from bisphenol A
Authors: Fallahi Hazhir , Koohmareh Gholam Ali 
Published: April 2012

AbstractReversible addition‐fragmentation chain transfer (RAFT) polymerization was performed in the presence of a new RAFT agent based on bisphenol A and modified clays and successfully prepared polystyrene/MMT nanocomposite. The structure of RAFT agent was investigated by Fourier transform infrared spectroscopy (FT‐IR) and proton nuclear magnetic resonance spectroscopy (1H NMR). The polymer had well‐defined molecular weight and narrow polydispersity obtained by gel permeation chromatography (GPC). The morphology of polystyrene/MMT nanocomposite was investigated by X‐ray diffraction (XRD) and transmission electron microscopy (TEM) and was found to be exfoliated. Thermal stability of pure polystyrene and polystyrene/MMT synthesized via RAFT polymerization was also investigated and showed better thermal stability for nanocomposite. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Application of melt‐blown technology for the manufacture of temperature‐sensitive nonwoven fabrics composed of polymer blends PP/PCL loaded with multiwall carbon nanotubes
Authors: Krucińska Izabella , Surma Beata , Chrzanowski Michał , Skrzetuska Ewa , Puchalski Michał 
Published: April 2012

AbstractThe main aim of this research was to detail the use of melt‐blown technology to manufacture a temperature‐sensitive nonwoven fabric. The sensor properties of the fabric were achieved by application of the optimal composition of immiscible polymer blends loaded with multiwall carbon nanotubes (MWCNTs). As the sensing phase, a dispersion of MWCNTs in poly(ε‐caprolactone) (PCL) was used. The sensing phase was blended with a matrix made of polypropylene (PP). Three different polymer compositions were subjected to the melt‐blowing process, changing the proportion of the matrix polymer to the dispersed phase to the range of 50–70% and changing the MWCNTs content to be between 1.2 and 2%. The selection of technological parameters was based on the thermal characteristics of the polymers used. Nonwoven fabrics made of these composites were characterized by measuring their electrical properties as a function of external stimuli. In particular, their responses to cycle changing of temperature in a range of 20–80°C were monitored. The 70%PP/28.8%/1.2%MWCNT nonwoven fabrics were observed to show the best sensitivity to changes in temperature between 50 and 60°C. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Influence of unsaturated acid monomer on the morphology of latex particles in the preparation of hollow latex via the alkali post‐treatment
Authors: Deng Wei , Ji Wenjiao , Jiang Yiming , Kan Chengyou 
Published: April 2012

AbstractMultistage hydrophilic core/hydrophobic shell latexes containing carboxyl groups were prepared via multistep seeded emulsion copolymerization, and particles with different morphologies were obtained after alkali post‐treatment. Influences of the type and content of unsaturated acid monomer on the polymerization and the particle morphology were investigated based on conductometric titration and TEM observation. Results showed that the hydrophilic core/hydrophobic shell particles could be easily formed using methacrylic acid (MAA) instead of acrylic acid. When MAA was 12.2 wt % in the core latex preparation, only fine pores existed inside the alkali‐treated particles. With MAA increased from 20.0 to 30.0 wt %, the alkali‐treated particle morphology evolved from porous, hollow to collapse structure. When MAA further increased to 40.0 wt %, it was difficult to prepare uniform multistage particles and distinct morphologies including solid, deficient swelling, hollow and collapse structure were coexistent in the alkali‐treated particles. Moreover, the forming mechanism of different morphologies was proposed. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Mechanically adaptive cellulose‐poly(acrylic acid) polymeric composites in wet–dry cycles
Authors: Luo Hongsheng , Hu Jinlian , Zhu Yong , Wu Jian‐Yong , Zhang Sheng , Fan Ying , Ye Guangdou 
Published: April 2012

AbstractPolymeric composites consisting of cellulose and poly(acrylic acid) (PAA) are prepared by coagulation/bulk polymerization method. Scanning electron microscopy and thermal gravimetric analysis are used to investigate the homogeneity and the heat‐induced water loss of the composites, respectively. The water absorbed in the composites has strong hydrogen bonding with the polymer chains, as determined by differential scanning calorimetry. The mechanical and structural properties of the composites vary reversibly when the composites are applied into specifically explored wet–dry cycles, which are comprehensively measured by dynamic mechanic analysis, wide‐angle X‐ray diffraction, and Fourier transform infrared. It is unprecedented to explore the cellulose‐PAA composites as a mechanical adaptive material. The cellulose and the PAA chemically react with each other. Most of the cellulose content remains in amorphous state. Thus, the water molecules can diffuse into the composites, leading to the wet–dry mechanical adaptability of the composites. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
The shearing effect on hydrophobically associative water‐soluble polymer and partially hydrolyzed polyacrylamide passing through wellbore simulation device
Authors: Zhang Rui , Ye Zhongbin , Peng Lin , Qin Ni , Shu Zheng , Luo Pingya 
Published: April 2012

AbstractHydrolyzed polyacrylamide (HPAM) was the traditional polymer and hydrophobically associative water‐soluble polymer (HAWP) was the new polymer with three‐dimensional network both used to flood to enhance oil recovery. The wellbore area was the most important part before the polymer solution injected into stratum. In this article, the shearing effects of the two polymers were studied by a wellbore simulation device. The viscosities of HPAM and HAWP solutions were both decreased around perforation of wellbore simulation device. Interestingly, viscosity of HAWP recovered from stratum 0.2 m. Until stratum 1.6 m, its viscosity recovered almost 50% of original. The data of intrinsic viscosity showed that the molecular chains of HAWP and HPAM were both degraded without any recovery. The contradiction was further studied by particle size and its microstructure. The mean particle size and particle size distribution data both showed HAWP recovered but HPAM was not. The microstructures of HAWP by atomic force microscopy images further explain the recovery of viscosity. The disassembled molecular chain was self‐assembled into aggregate to newly network by hydrophobes with weaker linking than original solution. While the microstructure of HPAM was thoroughly split up to randomly coil without linking. In addition, the viscoelasticity of HAWP was also recovered to some extent but HPAM was not. All the results proved that HAWP has mobility control ability to displace oil in reservoir even if suffered severely shearing by wellbore. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Stochastic processes in the development of pluripotency in vivo
Authors: Wennekamp Sebastian , Hiiragi Takashi 
Published: April 2012

AbstractThe divergence of the pluripotent inner cell mass and extraembryonic trophectoderm from an apparently homogenous population of cells is a decisive event in mammalian preimplantation development. While three models have been proposed to explain early cellular differentiation in the mouse embryo, the initial cue generating asymmetry within the embryo remains elusive. Recently, unexpected heterogeneity in the expression of crucial transcription factors within the blastocyst has raised the intriguing possibility that a stochastic component is involved in lineage divergence. Unraveling the molecular dynamics and developmental function of the observed heterogeneity awaits further investigations at the single‐cell level using quantitative live‐imaging with appropriate reporter lines. The possible involvement of dynamic heterogeneity in the establishment, maintenance and resolution of pluripotency makes this topic highly relevant not only to developmental biology, but also to stem cell research and regenerative medicine. In this review, we discuss the possible involvement of stochastic processes in lineage divergence and the establishment of pluripotency in vivo, based on recent data from mouse embryology and stem cell research.
Alleviating monoterpene toxicity using a two‐phase extractive fermentation for the bioproduction of jet fuel mixtures in Saccharomyces cerevisiae
Authors: Brennan Timothy C.R. , Turner Christopher D. , Krömer Jens O. , Nielsen Lars K. 
Published: April 2012

AbstractMonoterpenes are a diverse class of compounds with applications as flavors and fragrances, pharmaceuticals and more recently, jet fuels. Engineering biosynthetic pathways for monoterpene production in microbial hosts has received increasing attention. However, monoterpenes are highly toxic to many microorganisms including Saccharomyces cerevisiae, a widely used industrial biocatalyst. In this work, the minimum inhibitory concentration (MIC) for S. cerevisiae was determined for five monoterpenes: β‐pinene, limonene, myrcene, γ‐terpinene, and terpinolene (1.52, 0.44, 2.12, 0.70, 0.53 mM, respectively). Given the low MIC for all compounds tested, a liquid two‐phase solvent extraction system to alleviate toxicity during fermentation was evaluated. Ten solvents were tested for biocompatibility, monoterpene distribution, phase separation, and price. The solvents dioctyl phthalate, dibutyl phthalate, isopropyl myristate, and farnesene showed greater than 100‐fold increase in the MIC compared to the monoterpenes in a solvent‐free system. In particular, the MIC for limonene in dibutyl phthalate showed a 702‐fold (308 mM, 42.1 g L−1 of limonene) improvement while cell viability was maintained above 90%, demonstrating that extractive fermentation is a suitable tool for the reduction of monoterpene toxicity. Finally, we estimated that a limonane to farnesane ratio of 1:9 has physicochemical properties similar to traditional Jet‐A aviation fuel. Since farnesene is currently produced in S. cerevisiae, its use as a co‐product and extractant for microbial terpene‐based jet fuel production in a two‐phase system offers an attractive bioprocessing option. Biotechnol. Bioeng. 2012; 109: 2513–2522. © 2012 Wiley Periodicals, Inc.
Outcomes following surgery without radiotherapy for rectal cancer (Br J Surg 2012; 99: 137–143)
Authors: Janjua A Z , Moran B J 
Published: April 2012

Abstract
The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses should be sent electronically via the BJS website (http://www.bjs.co.uk). All letters will be reviewed and, if approved, appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length.
Assignment of Relative Configuration of Desoxypropionates by 1H NMR Spectroscopy: Method Development, Proof of Principle by Asymmetric Total Synthesis of Xylarinic Acid A and Applications
Authors: Schmidt Yvonne , Lehr Konrad , Colas Lucie , Breit Bernhard 
Published: April 2012

AbstractThe determination of the relative configuration of 1,3‐dimethyl‐substituted alkyl chains is possible by interpretation of 1H NMR shift differences. Additionally, assignments are feasible in a variety of deuterated solvents, because the corresponding shift differences are not significantly influenced by the solvent. The trends for Δδ values depending on functional groups adjacent to the stereogenic centers are shown. Based on a thorough comparison with literature data, the relative configuration of natural products can be predicted. For this purpose, we derived an empirical rule for the ranges in which Δδ values usually occur. Furthermore, we were able to proof the validity of our method by the successful prediction of the relative configuration for the polyketide natural product xylarinic acid A, which was confirmed by the asymmetric total synthesis of its enantiomer. Based on the proposed simple analysis of published 1H NMR data and the determination of the relevant chemical‐shift differences, we predicted the relative configurations of several previously unassigned natural products.
High‐Yield Diastereoselective Synthesis of Planar Chiral [2]‐ and [3]Rotaxanes Constructed from per‐Ethylated Pillar[5]arene and Pyridinium Derivatives
Authors: Ogoshi Tomoki , Yamafuji Daiki , Aoki Takamichi , Kitajima Keisuke , Yamagishi Tada‐aki , Hayashi Yoshihiro , Kawauchi Susumu 
Published: April 2012

AbstractPlanar chiral [2]‐ and [3]rotaxanes constructed from pillar[5]arenes as wheels and pyridinium derivatives as axles were obtained in high yield using click reactions. The process of rotaxane formation was diastereoselective; the obtained [2]rotaxane was a racemic mixture consisting of (pS, pS, pS, pS, pS) and (pR, pR, pR, pR, pR) forms of the per‐ethylated pillar[5]arene (C2) wheel, and other possible types of the [2]rotaxane did not form. Isolation of the enantiopure [2]rotaxanes with one axle through (pS, pS, pS, pS, pS)‐C2 or (pR, pR, pR, pR, pR)‐C2 wheels was accomplished. Furthermore, pillar[5]arene‐based [3]rotaxane was successfully synthesized by attachment of two pseudo [2]rotaxanes onto a bifunctional linker. [3]Rotaxane formed in a 1:2:1 mixture with one axle threaded through two (pS, pS, pS, pS, pS)‐C2, one (pS, pS, pS, pS, pS)‐C2 and one (pR, pR, pR, pR, pR)‐C2 (meso form), or two (pR, pR, pR, pR, pR)‐C2 wheels. The [3]rotaxane enantiomers and the meso form were successfully isolated using appropriate chiral HPLC column chromatography. The procedure developed in this study is the starting point for the creation of pillar[5]arene‐based interlocked molecules.
ChemInform Abstract: Highly Enantioselective Phase‐Transfer Catalytic α‐Alkylation of α‐tert‐Butoxycarbonyllactams: Construction of β‐Quaternary Chiral Pyrrolidine and Piperidine Systems.
Authors: Park Yohan , Lee Young Ju , Hong Suckchang , Kim Mi‐hyun , Lee Myungmo , Kim Taek‐Soo , Lee Jae Kyun , Jew Sang‐sup , Park Hyeung‐geun 
Published: April 2012

AbstractThe α‐alkylation of title lactams (I) and (IV) proceeds smoothly in the presence of a chiral phase‐transfer organocatalyst to afford the corresponding lactams containing an all‐carbon quaternary stereocenter (III) and (V), resp., in up to 98% optical purity.
ChemInform Abstract: Silver Compounds in Synthetic Chemistry. Part 6. Me3SiCF3/AgF/Cu — A New Reagents Combination for Selective Trifluoromethylation of Various Organic Halides by Trifluoromethylcopper, CuCF3.
Authors: Kremlev Mikhail M. , Mushta Aleksej I. , Tyrra Wieland , Yagupolskii Yurii L. , Naumann Dieter , Moeller Angela 
Published: April 2012

AbstractTrifluoromethylcopper, generated in situ by an oxidative transmetalation route, exhibits excellent reactivity and selectivity in the substitution of halide bonded to aromatic or heterocyclic compounds for the trifluoromethyl group without the need of an additional catalyst.
ChemInform Abstract: Synthesis of 2‐Hetaryl‐2‐(tetrahydrofuran‐2‐ylidene)acetonitriles.
Authors: Khilya O. V. , Volovnenko T. A. , Turov A. V. , Zubatyuk R. I. , Shishkin O. V. , Volovenko Yu. M. 
Published: April 2012

AbstractThe intramolecular formation of title compounds (IV) and (VII) is studied and the product geometry is discussed.
ChemInform Abstract: Fluorinated [1,2,4]Triazolo[1,5‐a]pyrimidines and [1,2,4]Triazolo[5,1‐c]triazines.
Authors: Ulomskiy E. N. , Medvedeva N. R. , Shchepochkin A. V. , Eltsov O. S. , Rusinov V. L. , Chupakhin O. N. , Deeva E. G. , Kiselev O. I. 
Published: April 2012

AbstractTriazolo‐fused uracil analogues (III), (V), and (VII) are synthesized and evaluated for their antiviral activity and cytotoxicity.
ChemInform Abstract: Ruthenium‐Catalyzed Synthesis of Enaminones.
Authors: Koduri Naga Durgarao , Scott Halee , Hileman Bethany , Cox Justin D. , Coffin Michael , Glicksberg Lindsay , Hussaini Syed R. 
Published: April 2012

AbstractGrubbs I catalyst efficiently promotes the condensation of various thioamides with α‐diazodicarbonyl compounds.
ChemInform Abstract: Photoredox‐Initiated α‐Alkylation of Imines Through a Three‐Component Radical/Cationic Reaction.
Authors: Courant Thibaut , Masson Geraldine 
Published: April 2012

AbstractKey features of the approach are the wide substance scope, short reaction times, high atom‐economy (no side products) and good to excellent chemical yields.
ChemInform Abstract: Ether‐Tethered Ru(II)/TsDPEN Complexes: Synthesis and Applications to Asymmetric Transfer Hydrogenation.
Authors: Parekh Vimal , Ramsden James A. , Wills Martin 
Published: April 2012

AbstractRuthenium monomer complex RUM, formed in situ from dimer RUD in the presence of HCOOH/Et3N, exhibits excellent activity in the title reaction of acetophenone and analogues.
ChemInform Abstract: N‐Heterocyclic Carbenes. Part 4. Synthesis of Symmetrical and Unsymmetrical Imidazolium Salts with Abietane Moiety.
Authors: Glushkov V. A. , Arapov K. A. , Kotelev M. S. , Rudowsky K. S. , Suponitsky K. Yu. , Gorbunov A. A. , Maiorova O. A. , Slepukhin P. A. 
Published: April 2012

AbstractThe most active ligands for the reaction are shown.
ChemInform Abstract: Palladium‐Catalyzed Carbonylative Negishi‐Type Coupling of Aryl Iodides with Benzyl Chlorides.
Authors: Wu Xiao‐Feng , Schranck Johannes , Neumann Helfried , Beller Matthias 
Published: April 2012

AbstractThe optimized conditions are also successfully applied for the coupling of benzoyl chlorides and benzyl chlorides under CO‐free conditions.
ChemInform Abstract: Convenient Synthesis of 2‐Allyl‐3‐bromo‐1,4‐dimethoxynaphthalene: Key Intermediate as Building Block for Bioactive Pyranonaphthoquinones.
Authors: Limaye Rohan A. , Gaur Pinki , Paradkar Madhusudan V. , Natu Arun D. 
Published: April 2012

AbstractThe presented approach avoids the usage of highly lachrymatric 2‐bromonaphthoquinone.
ChemInform Abstract: Facile Synthesis of 3a,6a‐Dihydrofuro[2,3‐b]furans and Polysubstituted Furans Involving Dearomatization of Furan Ring via Electrocyclic Ring‐Closure.
Authors: Yin Biaolin , Zeng Guohui , Cai Congbi , Ji Fanghua , Huang Li , Li Zhengrong , Jiang Huanfeng 
Published: April 2012

AbstractFurobenzofuran and thienofuran analogues are also available.
ChemInform Abstract: An eco‐Safe Approach to Benzopyranopyrimidines and 4H‐Chromenes in Ionic Liquid at Room Temperature.
Authors: Gupta Amit Kumar , Kumari Kumkum , Singh Neetu , Raghuvanshi Dushyant Singh , Singh Krishna Nand 
Published: April 2012

AbstractIf amines are used as the third component, 4‐amino‐benzopyranopyrimidines (IV) are isolated.
ChemInform Abstract: Synthesis and Some Properties of 5‐Alkylamino‐2‐(phthalimidoalkyl)‐1,3‐oxazole‐4‐carbonitriles (VIII).
Authors: Chumachenko S. A. , Shablykin O. V. , Vasilenko A. N. , Brovarets V. S. 
Published: April 2012

AbstractHydrazinolysis of phthalimidoethyloxazole (VIIIc) affords the expected free amine (IX), whilst a recyclization product (X) is formed in the hydrazinolysis of phthalimidopropyl analogue (VIIIg).
ChemInform Abstract: An Enantioselective Approach Toward 3,4‐Dihydroisocoumarin Through the Bromocyclization of Styrene‐Type Carboxylic Acids.
Authors: Chen Jie , Zhou Ling , Tan Chong Kiat , Yeung Ying‐Yeung 
Published: April 2012

AbstractTreatment of styrene‐type carboxylic acids with NBS in the presence of (Ia) provides a facile, efficient, and enantioselective approach to 4‐bromo‐3,4‐dihydroisocoumarins.