bluuebunny/crossref_metadata_2025 huggingface dataset:
Poly(2‐alkyloyloxyethylacrylate) and poly(2‐alkyloyloxyethylacrylate‐co‐methylacrylate) comblike polymers as novel phase‐change materials for thermal energy storage
Authors: Alkan Cemil , Ensari Ömer Faruk , Kahraman Derya
Published: April 2012

A series of poly(2‐alkyloyloxyethylacrylate) and poly(2‐alkyloyloxyethylacrylate‐co‐methylacrylate) polymers as novel polymeric phase‐change materials (PCMs) were synthesized starting from 2‐hydroxyethylacrylate and fatty acids. The chemical structure and crystalline morphology of the synthesized copolymers were characterized with Fourier transform infrared and 1H‐NMR spectroscopy and polarized optical microscopy, respectively, and their thermal energy storage properties and thermal stability were investigated with differential scanning calorimetry and thermogravimetric analysis, respectively. The thermal conductivities of the PCMs were also measured with a thermal property analyzer. Moreover, thermal cycling testing showed that the copolymers had good thermal reliability and chemical stability after they were subjected to 1000 heating/cooling cycles. The synthesized poly(2‐alkyloyloxyethylacrylate) polymers and poly(2‐alkyloyloxyethylacrylate‐co‐methylacrylate) copolymers as novel PCMs have considerable potential for thermal energy storage and temperature‐control applications. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Melt index prediction by RBF neural network with an ICO‐VSA hybrid optimization algorithm
Authors: Huang Mingyu , Liu Xinggao , Li Jiubao
Published: April 2012

Melt index (MI) is considered as one of the most significant parameter to determine the quality and the grade of the practical polypropylene polymerization products. A novel ICO‐VSA‐RNN (RBF neural network with ICO‐VSA algorithm) MI prediction model is proposed based on radial basis function (RBF) neural network and improved chaos optimization (ICO), and variable‐scale analysis (VSA), where the ICO is first added and then combined with the VSA to overcome the defects of ICO and VSA, then the parameters of the RBF neural network are optimized with them. At last, the RBF neural network model for MI prediction model is developed. Further researches on the optimal RBF neural network model of MI prediction are carried out with the data from a real industrial plant, and the prediction results show that the performance of this prediction model is much better than the RBF neural network model without optimization. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis and curing of liquid crystalline epoxy resin based on asymmetric mesogen
Authors: Xiao Yong , Cao Lu , Feng Jinhua , Yuan Liangjie
Published: April 2012

A novel liquid crystalline epoxy resin (LCER) derived from asymmetric mesogen unit was synthesized. Its structure and liquid crystalline behavior were characterized by hydrogen nuclear magnetic resonance (H‐NMR), differential scanning calorimetry (DSC), polarized optical microscopy (POM). The results indicated that the LCER converted to a nematic phase at 85°C during heating and finally became isotropic at 145°C. The curing behavior and phase behavior of the LCER with 4,4′‐diaminodiphenyl methane and methyl hexahydrophthalic anhydride were also studied by DSC and POM, respectively. Their apparent activation energy (Ea) was evaluated according to the Ozawa's isoconversional method. The results suggested that autocatalytic reaction had occurred in these two systems. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Heterogeneous synthesis of chelating resin organophosphonic acid‐functionalized silica gel and its adsorption property of heavy metal ions from fuel ethanol solutions
Authors: Wang Zengdi , Yin Ping , Qu Rongjun , Xu Qiang
Published: April 2012

In this study, chelating resin silica gel chemically modified by poly(triethylenetetramine bis(methylenephosphonic acid)) (denoted as SG‐Cl‐T‐P) was successfully developed by heterogeneous synthesis method and used for adsorptive removal of heavy metal ions from fuel ethanol solutions, and the relevant modified organic group was calculated by DFT method at the B3LYP/6‐31 + G(d) level. SG‐Cl‐T‐P was characterized by Fourier transform infrared spectrometer, scanning electron microscope, energy dispersive X‐ray analysis system, porous analysis, etc. SG‐Cl‐T‐P has been used to investigate the adsorption of Hg(II),Cu(II), Mn(II), Co(II), Zn(II), Ni(II), Fe(III), and Cd(II) metal ions from ethanol solutions. The research results revealed that it has the better adsorption capacity for Hg(II) and Cd(II). © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Modeling the mechanical properties of notched aluminum—epoxy particulate composites
Authors: Papanicolaou G.C. , Xepapadaki A.G. , Angelakopoulos G.A.
Published: April 2012

The aim of the present investigation is to study both the influence of particle weight fraction (0–50%) and the effect of the notch length on the static mechanical properties of aluminum particle epoxy composites. Experimental results in both cases were compared with three different theoretical models, previously developed by the first author and presented in a series of publications. First, for the evaluation of the maximum strength the particle sectioning model (PSM) was applied. Next, for the evaluation of the elastic modulus as a function of aluminum powder weight fraction, the interphase model (IM) was applied. Finally, in the case of notches' length influence, the residual property model, (RPM), was applied. This model can be applied for the description of the residual behavior of materials after any type of damage. In all cases, predicted values showed a satisfactory agreement with experimental findings. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Study on pentaerythritol–zinc as a novel thermal stabilizer for rigid poly(vinyl chloride)
Authors: Xu Shilu , Li Degang , Yu Xianjin , Zhang Yali , Yu Yuanzhang , Zhou Min , Tang Shouyu
Published: April 2012

Pentaerythritol–zinc (penzinc) was prepared by a solid‐phase reaction technique. The principal volatile products of the reaction between pentaerythritol and ZnO were analyzed with a coupled thermogravimetry—mass spectrometery system. The results indicated that a large amount of water was formed at the reaction temperature. Scanning electron microscopy (SEM) results showed the appearance of penzinc as flaky particles. Accordingly, the penzinc obtained through the dehydration between pentaerythritol and ZnO is likely to be a monopentaerythritol complex, such as zinc monoglycerolate. The thermal stability of poly(vinyl chloride) (PVC) with penzinc as a thermal stabilizer was investigated by a Congo Red test, Oven aging test and thermal gravimetric analysis (TGA). The Congo Red test showed the thermal stability time of PVC with penzinc was 38 min, longer than those with commercial thermal stabilizers. TGA indicated that the penzinc had little impact on the thermal degradation of PVC, but could increase the mass of residues. Oven aging test showed that the penzinc could significantly retard the discoloration during the long‐term decomposition of PVC. Meanwhile, no “zinc burning” was observed in the PVC with penzinc. These results indicate that the penzinc is an excellent thermal stabilizer for rigid PVC. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Poly(lactic acid)‐modified films for food packaging application: Physical, mechanical, and barrier behavior
Authors: Siracusa Valentina , Blanco Ignazio , Romani Santina , Tylewicz Urtzula , Rocculi Pietro , Rosa Marco Dalla
Published: April 2012

Poly(lactic acid) (PLA) is now a very attractive polymer for food packaging application because in addition of being thermoplastic, biodegradable, compostable, and produced from renewable resources, it shows same behavior in mechanical, thermal, and barrier properties comparable to the most used synthetic polymers like polystyrene and poly(ethylene terephthalate). In this work, we take into consideration four commercial PLA films, natural‐ and surface‐modified, to make a correlation between mechanical, thermal, and barrier properties due to the surface modification, to well understand whether PLA is adapt to packaging application, especially in the food field. Films were studied by tensile testing, simultaneous differential thermal analysis/thermogravimetry, differential scanning calorimetry, permeation to carbon dioxide and oxygen at different temperature (7 and 23°C) and FTIR spectroscopic analysis. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Studies on recyclability of polyhydroxybutyrate‐co‐valerate bioplastic: Multiple melt processing and performance evaluations
Authors: Zaverl Matthew , Seydibeyoğlu M. Özgür , Misra Manjusri , Mohanty Amar
Published: April 2012

Recyclability of the bioplastic polyhydroxybutyrate‐co‐valerate (PHBV) was studied with multiple melt processing (five cycles), with their performances evaluated. A batch of PHBV was processed with a twin screw extrusion followed by injection molding. This operation was repeated five times and samples were collected from each cycle for characterization. For each cycle, the mechanical properties were characterized with tensile, flexural, and impact testing, along with dynamic mechanical analysis. The results showed that the mechanical properties are maintained for four cycles; but in the fifth cycle, there was slight decrease in the properties. Gel permeation chromatography studies revealed that the molecular weight of the polymer does not decrease drastically; however, a drop was observed after third, fourth, and fifth cycle (8.7% decrease after third cycle, 13.5% decrease after fourth cycle, and 16.6% decrease after fifth cycle). The differential scanning calorimeter showed that the glass transition and melting temperatures did not change upon reprocessing, but the degree of crystallinity was reduced as a consequence of melt processing. The thermal gravimetric analysis showed that the onset value of thermal decomposition decreased very slightly. It was observed by Fourier transform infrared spectroscopy that the chemical structure of PHBV was maintained without any side chain reaction during processing. Scanning electron microscopy studies from the fractured surfaces of Cycles 1 and 5 confirmed that the uniformity of PHBV surfaces was maintained after five cycles, coinciding with the mechanical tests. The density measurements revealed that there was no change in the density of PHBV. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Modeling the strain dependence of torque harmonics as measured through large‐amplitude oscillatory shear rheometry
Authors: Leblanc Jean L.
Published: April 2012

Data describing the stress response to large‐amplitude oscillatory shear can be considered as the nonlinear viscoelastic signature of polymer materials. How such data can be fitted with an appropriate equation is a problem of prime importance because (1) it allows results gathered in a large strain window to be summarized in a small number of representative parameters and (2) it permits a physical significance to be sought for equation parameters. This article analyzes and discusses several mathematical relationships that were proposed in the literature to fit harmonics vs. strain data, and probes their relative merits with various sets of experimental results. A simple four‐parameter model is shown to encompass all the other approaches and to yield parameters that correctly describe not only material behavior in the linear‐to‐nonlinear transition region but also in the asymptotic high‐strain range. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Stress/strain development around a spherical inclusion in a polymeric matrix: The effects of particle and matrix mechanical characteristics and thermal expansivity difference
Authors: Hosseinpour Dariush , Berg John C.
Published: April 2012

For a spherical inclusion embedded in an infinite polymeric matrix, the Goodier Model, combined with thermal stress contribution, is applied to establish the stress/strain fields around a spherical particle in different particle/matrix combinations, including TiO2, alumina, silica, steel, polystyrene, and polyvinyl butyral particles embedded in a range of polymeric matrices. This approach provides the basis for examining the effects of different parameters such as Young's modulus and Poisson's ratio of the particle and matrix, and the thermal history of samples on the failure‐initiation criteria. An explanation is provided for divergent results obtained for very soft and elastic particles. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Macromolecular design of novel sulfur‐containing copolyesters with promising mechanical properties
Authors: Gigli M. , Lotti N. , Gazzano M. , Finelli L. , Munari A.
Published: April 2012

The miscibility of poly(butylene succinate) (PBS)/poly(butylene thiodiglycolate) (PBTDG) blends was investigated by DSC technique. PBS and PBTDG were completely immiscible in as blended‐state, as evidenced by the presence of two Tgs at −34 and −48°C, respectively. The miscibility changes upon mixing at elevated temperature: the original two phases merged into a single one because of transesterification reactions. Poly(butylene succinate/thiodiglycolate) block copolymers, prepared by reactive blending of the parent homopolymers, were studied to investigate the effects of transesterification reactions on the molecular structure and solid‐state properties. 13C‐NMR analysis evidenced the formation of copolymers whose degree of randomness increased with mixing time. Thermal characterization results showed that all the samples were semicrystalline, with a soft rubbery amorphous phase and a rigid crystal phase whose amount decreased by introducing BTDG units into the PBS chain (20 ≤ χc ≤ 41). Lastly, the mechanical properties were found strictly related to crystallinity degree (χc), the random copolymer, exhibiting the lowest elastic modulus (E = 61 MPa) and the highest deformation at break (εb (%) = 713). © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Structure and physical properties of gelatin fibers prepared by gel‐spinning in ethylene glycol
Authors: Midorikawa Takehiko , Lawal Olayide Samuel , Sasaki Yosiko , Fukae Ryohei
Published: April 2012

Gelatin fibers were produced by gel‐spinning using ethylene glycol as the solvent. Gelation conditions, drawing temperature, and draw ratio were studied. Physical properties of the fibers were characterized by mechanical tests, thermal analysis, X‐ray diffractometry, and scanning electron microscopy. The mechanical strength of the fibers increased with increased draw ratio. The gelatin fiber prepared by extrusion of the gelatin (15 wt %)/ethylene glycol into methanol at −20°C and drawn up to seven times its original length at 5°C had the highest tensile strength (405 MPa), a Young's modulus of 11 GPa, and a storage modulus of 7.9 GPa at 200°C. Remarkable differences were observed between the morphology of the undrawn and the drawn fibers. The results show that a gelatin fiber with very good mechanical properties can be prepared using ethylene glycol as the dispersion medium. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
SERINE PROTEINASE LIKE ACTIVITY IN APOLIPOPHORIN III FROM THE HEMOLYMPH OF DESERT LOCUST, Schistocerca gregaria
Authors: Malik Zulfiqar A. , Amir Sumaira , Venekei István
Published: April 2012

Apolipophorin III (apoLp‐III) has been known as a lipid transport protein of insects. Recent studies indicated the involvement of apoLp‐III in immune reactions and in the control of cell destruction, but no enzymatic activity has so far been detected. In the present study, a protease from the hemolymph of Schistocerca gregaria was purified to homogeneity and its enzymatic activity was examined. Identity as chymotrypsin‐like proteinase was established by its high affinity toward bulky aromatic substrates and its catalytic specificity for amide or ester bonds on the synthetic substrates, Suc‐Ala‐Ala‐Pro‐Xaa‐AMC (where Xaa was Phe, Tyr, Trp, and Lys, and AMC is 7‐amino‐4‐methyl‐coumarin) and thiolbenzyl ester substrate Suc‐Ala‐Ala‐Pro‐Phe‐SBzl. The sensitivity for serine protease and chymotrypsin‐specific covalent inhibitors, PMSF, TPCK, and noncovalent inhibitors SGCI, showed that it is a chymotrypsin‐like proteinase. It showed its maximum activity at pH 8.0 and 55°C for the hydrolysis of Suc‐Ala‐Ala‐Pro‐Tyr‐AMC. According to similarities in the amino terminal sequence, molar mass (19 kDa) and retention on reversed‐phase analytical high-performance liquid chromatography (HPLC) column, this protein is S. gregaria homologue of Locusta migratoria apoLp‐III. Our data suggest that apoLp‐III also has an inherent proteolytic activity. Results indicated that S. gregaria apoLp‐III is a good catalyst and could be used as a biotechnological tool in food processing and in agricultural biotechnology.
Using model organism Saccharomyces cerevisiae to evaluate the effects of ELF‐MF and RF‐EMF exposure on global gene expression
Authors: Chen Guangdi , Lu Deqiang , Chiang Huai , Leszczynski Dariusz , Xu Zhengping
Published: April 2012

The potential health hazard of exposure to electromagnetic fields (EMF) continues to cause public concern. However, the possibility of biological and health effects of exposure to EMF remains controversial and their biophysical mechanisms are unknown. In the present study, we used Saccharomyces cerevisiae to identify genes responding to extremely low frequency magnetic fields (ELF‐MF) and to radiofrequency EMF (RF‐EMF) exposures. The yeast cells were exposed for 6 h to either 0.4 mT 50 Hz ELF‐MF or 1800 MHz RF‐EMF at a specific absorption rate of 4.7 W/kg. Gene expression was analyzed by microarray screening and confirmed using real‐time reverse transcription‐polymerase chain reaction (RT‐PCR). We were unable to confirm microarray‐detected changes in three of the ELF‐MF responsive candidate genes using RT‐PCR (P > 0.05). On the other hand, out of the 40 potential RF‐EMF responsive genes, only the expressions of structural maintenance of chromosomes 3 (SMC3) and aquaporin 2 (AQY2 (m)) were confirmed, while three other genes, that is, halotolerance protein 9 (HAL9), yet another kinase 1 (YAK1) and one function‐unknown gene (open reading frame: YJL171C), showed opposite changes in expression compared to the microarray data (P < 0.05). In conclusion, the results of this study suggest that the yeast cells did not alter gene expression in response to 50 Hz ELF‐MF and that the response to RF‐EMF is limited to only a very small number of genes. The possible biological consequences of the gene expression changes induced by RF‐EMF await further investigation. Bioelectromagnetics 33:550–560, 2012. © 2012 Wiley Periodicals, Inc.
Manufacture of Granular Polysilicon from Trichlorosilane in a Fluidized‐Bed Reactor
Authors: Wang C. J. , Wang T. F. , Wang Z. W.
Published: April 2012

Manufacturing of polysilicon by chemical vapor deposition from SiHCl3 in a fluidized‐bed reactor was studied. The effects of reaction temperature, H2/SiHCl3 ratio, gas velocity, and seed particle loading were evaluated. The outlet gas composition was analyzed by gas chromatography. The physical features of the product particles were determined by scanning electron microscopy and laser particle size analyzer. Well‐grown product particles were obtained. The temperature and H2/SiHCl3 ratio significantly affected conversion, yield, and selectivity, which were less affected by gas velocity and seed particle loading at higher temperatures. The surface reaction kinetics determined the product yield only at lower temperatures, and thermodynamic equilibrium was approached at temperatures above 900 °C.
ChemInform Abstract: Photooxidation of Coordinated Dinitrogen, Photolysis of the ClO2 Adduct of [(NH3)5Os(μ‐N2)Os (NH3)5]5+.
Authors: Vogler Arnd , Kunkely Horst
Published: April 2012

For the first time oxidative splitting of coordinated dinitrogen is achieved photochemically.
ChemInform Abstract: Tetrahydroisoquinoline‐Based N‐Oxides as Chiral Organocatalysts for the Asymmetric Allylation of Aldehydes.
Authors: Naicker Tricia , Arvidsson Per I. , Kruger Hendrik G. , Maguire Glenn E. M. , Govender Thavendran
Published: April 2012

Novel Lewis base N‐oxide organocatalysts possessing tetrahydroisoquinoline as a readily tunable backbone are synthesized and evaluated in asymmetric allylation reactions of aromatic and α,β‐unsaturated aldehydes.
ChemInform Abstract: Facile Synthesis of Dihaloheterocycles via Electrophilic Iodocyclization.
Authors: Yang Fan , Jin Tienan , Bao Ming , Yamamoto Yoshinori
Published: April 2012

The present new and efficient iodocyclization of a wide range of substituted propargyl alcohols bearing ‐OH, ‐NTs, and ‐SAc functional groups at C4‐position with molecular iodine or bromoiodine affords the corresponding 3,4‐dihalodihydrofurans, ‐pyrroles, and ‐thiophenes in good yields.
ChemInform Abstract: Selective Oxidation of Unsaturated Alcohols Catalyzed by Sodium Nitrite and 2,3‐Dichloro‐5,6‐dicyano‐1,4‐benzoquinone with Molecular Oxygen under Mild Conditions.
Authors: Wang Lianyue , Li Jun , Yang Hua , Lv Ying , Gao Shuang
Published: April 2012

The procedure allows a simple and efficient access to conjugated aldehydes and ketones.
ChemInform Abstract: Reversing the Reactivity of Carbonyl Functions with Phosphonium Salts: Enantioselective Total Synthesis of (+)‐Centrolobine.
Authors: Fujioka Hiromichi , Yahata Kenzo , Kubo Ozora , Sawama Yoshinari , Hamada Tomohito , Maegawa Tomohiro
Published: April 2012

Initial selective masking of the aldehyde function in ketoaldehydes with PPh3 and TmsOTf permits the selective reduction of the keto function or its alkylation with Grignard reagents followed by deprotection.
ChemInform Abstract: Nitromethane with IBX/TBAF as a Nitrosating Agent: Synthesis of Nitrosamines from Secondary or Tertiary Amines under Mild Conditions.
Authors: Potturi Hima K. , Gurung Ras K. , Hou Yuqing
Published: April 2012

Primary amines and amides do not react.
ChemInform Abstract: One‐Pot Ester Synthesis from Allyl and Benzyl Halides and Alcohols by Palladium‐Catalyzed Carbonylation
Authors: Tommasi Sara , Perrone Serena , Rosato Francesca , Salomone Antonio , Troisi Luiginio
Published: April 2012

A mild and efficient synthesis of esters is presented.
ChemInform Abstract: Electrochemically Supported Deoxygenation of Epoxides into Alkenes in Aqueous Solution.
Authors: Huang Jing‐Mei , Lin Zhi‐Quan , Chen Dong‐Song
Published: April 2012

The reaction proceeds in an undivided cell fitted with a pair of zinc electrodes by building up a zinc nanostructure on the electrode surface.
ChemInform Abstract: One‐Pot Near‐Ambient Temperature Syntheses of Aryl(difluoroenol) Derivatives from Trifluoroethanol.
Authors: Kyne Sara H. , Percy Jonathan M. , Pullin Robert D. C. , Redmond Joanna M. , Wilson Peter G.
Published: April 2012

The development of a dehydrofluorination/zincation and Negishi coupling protocol is presented.
ChemInform Abstract: Efficient Palladium‐Catalyzed Amination of Aryl Chlorides Using Di(dicyclohexylamino)phenylphosphine as a PN2 Ligand.
Authors: Kim Bo Ram , Cho Su‐Dong , Kim Eun Jung , Lee In‐Hye , Sung Gi Hyeong , Kim Jeum‐Jong , Lee Sang‐Gyeong , Yoon Yong‐Jin
Published: April 2012

A new, efficient ligand for the Pd‐catalyzed amination of aryl chlorides is found.
ChemInform Abstract: Construction of 1,2,5‐Tricarbonyl Compounds Using Methyl Cyanoacetate as a Glyoxylate Anion Synthon Combined with Copper(I) Iodide‐Catalyzed Aerobic Oxidation.
Authors: Kim Se Hee , Kim Ko Hoon , Kim Jae Nyoung
Published: April 2012

A variety of α‐cyano‐δ‐ketocarboxylates (I) and (III), obtained by conjugate addition of cyanoacetate towards α,β‐unsaturated ketones, is efficiently oxidized to the corresponding α,δ‐diketo esters (II) and (IV), respectively.
ChemInform Abstract: Enantioselective Reaction of Imines and Benzyl Nitriles Using Palladium Pincer Complexes with C2‐Symmetric Chiral Bis(imidazoline)s.
Authors: Hyodo Kengo , Nakamura Shuichi , Tsuji Kotaro , Ogawa Takahiro , Funahashi Yasuhiro , Shibata Norio
Published: April 2012

A variety of aromatic imines (I) reacts with diverse benzyl nitriles (II) and (VII) in the presence of a novel Pd pincer complex to afford the corresponding β‐amino nitriles (III) and (VIII), resp., in moderate to good diastereo‐ and enantioselectivities (up to 92% e.e.).
ChemInform Abstract: Synthesis of Sulfonyl Chlorides and Sulfonic Acids in SDS Micelles.
Authors: Bahrami Kiumars , Khodaei Mohammad M. , Abbasi Jamshid
Published: April 2012

The selective oxidation of different sulfides (or the analogous disulfides) is efficiently achieved with a combination of H2O2 and POCl3 in optimized ratios.
ChemInform Abstract: Room‐Temperature C—H Arylation: Merger of Pd‐Catalyzed C—H Functionalization and Visible‐Light Photocatalysis.
Authors: Kalyani Dipannita , McMurtrey Kate B. , Neufeldt Sharon R. , Sanford Melanie S.
Published: April 2012

In the presence of Pd and Ru catalysts, benzenes bearing heterocyclic or oxime units are found to undergo new and mild ortho‐arylation.
ChemInform Abstract: Abnormal N‐Heterocyclic Carbene Palladium Complex: Living Catalyst for Activation of Aryl Chlorides in Suzuki—Miyaura Cross‐Coupling.
Authors: Sau Samaresh Chandra , Santra Subhankar , Sen Tamal K. , Mandal Swadhin K. , Koley Debasis
Published: April 2012

The catalyst remains active for 10 successive cycles.
ChemInform Abstract: Dihydroxylation‐Based Approach for the Asymmetric Syntheses of Hydroxy‐γ‐butyrolactones.
Authors: Peed Jennifer , Davies Iwan R. , Peacock Lucy R. , Taylor James E. , Kociok‐Koehn Gabriele , Bull Steven D.
Published: April 2012

Treatment of unsaturated amides of type (I), (IV), and (IX) with NMO/OsO4 leads to triols which spontaneously undergo cyclization to afford biologically important optically active hydroxy‐γ‐butyrolactones.
ChemInform Abstract: Palladium‐Catalyzed Oxidative Arylalkylation of Activated Alkenes: Dual C—H Bond Cleavage of an Arene and Acetonitrile.
Authors: Wu Tao , Mu Xin , Liu Guosheng
Published: April 2012

A novel process is discovered to provide cyanoethyl‐substituted indolones in moderate to good yields.
ChemInform Abstract: Chiral Broensted Acid Catalyzed Stereoselective Addition of Azlactones to 3‐Vinylindoles for Facile Access to Enantioenriched Tryptophan Derivatives.
Authors: Terada Masahiro , Moriya Kenichi , Kanomata Kyohei , Sorimachi Keiichi
Published: April 2012

A chiral BINAP‐derived phosphoric acid is demonstrated to be an efficient catalyst for the formation of title compounds with adjacent quaternary and tertiary stereogenic centers after alkaline methanolysis.
ChemInform Abstract: The Use of Glucose as Alternative Reducing Agent in Copper‐Catalyzed Alkyne—Azide Cycloaddition.
Authors: Garcia Marco A. , Rios Zita G. , Gonzalez Jaime , Perez Victor M. , Lara Nancy , Fuentes Aydee , Gonzalez Carlos , Corona David , Cuevas‐Yanez Erick
Published: April 2012

An inexpensive method for the synthesis of 1,2,3‐triazoles uses a catalytic system prepared from Fehling reagent and glucose.
ChemInform Abstract: An Efficient Synthesis of 4‐Aryl‐1,4‐dihydropyridines via VB1‐Catalyzed Hantzsch Reaction.
Authors: Fan Chuangang , Song Mingzhi
Published: April 2012

A simple and environmentally benign synthesis of title compounds (III) is presented.
ChemInform Abstract: Selective Synthesis of Fused 1,4‐ and 1,2‐Dihydropyridines by Domino Reactions of Arylamines, Acetylenedicarboxylate, Aldehydes, and Cyclic 1,3‐Diketones.
Authors: Sun Jing , Sun Yan , Gao Hong , Yan Chao‐Guo
Published: April 2012

Domino reaction of arylamines (II) and (VI) with acetylenedicarboxylate (I), cyclic β‐dicarbonyl compounds (III) and (VII) and aromatic aldehydes (IV) provides access towards fused 1,4‐dihydropyridine derivatives (V) and (VIII) in moderate yields.
ChemInform Abstract: An Efficient Access to 2,3‐Diarylimidazo[1,2‐a]pyridines via Imidazo[1,2‐a]pyridin‐2‐yl Triflate Through a Suzuki Cross‐Coupling Reaction‐Direct Arylation Sequence.
Authors: Marhadour Sophie , Bazin Marc‐Antoine , Marchand Pascal
Published: April 2012

A straightforward strategy for the synthesis of title compounds via Suzuki coupling of triflates or analogous halides followed by a direct C‐H arylation is developed.
ChemInform Abstract: Lewis Acid‐Catalyzed Selective Synthesis of Diversely Substituted Indolo‐ and Pyrrolo[1,2‐a]quinoxalines and Quinoxalinones by Modified Pictet—Spengler Reaction.
Authors: Verma Akhilesh K. , Jha Rajeev R. , Sankar V. Kasi , Aggarwal Trapti , Singh Rajendra P. , Chandra Ramesh
Published: April 2012

Lewis acid‐catalyzed reaction of N‐(o‐aminophenyl)pyrrole (I) with various aromatic aldehydes in short reaction time (1‐2h) proceeds by a modified Pictet—Spengler reaction to give dihydropyrroloquinoxalines (III).
ChemInform Abstract: An Efficient Metal‐Free Synthesis of 2‐(Pyrazin‐2‐yl)benzimidazoles from Quinoxalinones and Diaminomaleonitrile via a Novel Rearrangement.
Authors: Mamedov Vakhid A. , Zhukova Nataliya A. , Beschastnova Tat'yana N. , Zakirova El'vira I. , Kadyrova Saniya F. , Mironova Ekaterina V. , Nikonova Anna G. , Latypov Shamil K. , Litvinov Igor A.
Published: April 2012

An interesting synthesis of title compounds is achieved by acid‐promoted rearrangement of intermediates (III) or (VI), readily prepared by reaction of acyl‐ substituted quinoxalinones with diaminomalononitrile.
ChemInform Abstract: Efficient Synthesis of Piperazinediones Using Potassium Iodide Catalysis in Aqueous Media.
Authors: Wen Yong‐Hong , Chen Xiao‐Na , Wen Hui‐Ling , Tang Xiao‐Fang
Published: April 2012

A mild, inexpensive, and environmentally friendly synthesis of the title compounds (II) is developed.
ChemInform Abstract: An Efficient One‐Step Synthesis of Piperidin‐2‐yl and Pyrrolidin‐2‐yl Flavonoid Alkaloids Through Phenolic Mannich Reactions.
Authors: Nguyen Thanh Binh , Wang Qian , Gueritte Francoise
Published: April 2012

The title reaction of chrysin (I) can be controlled by the conditions: simply running in a solvent mixture, the process affords C‐6 substituted products, whereas in the presence of aqueous NaOH, C‐8 substitution takes place.
ChemInform Abstract: Ion Transport in Liquid Salt Solutions with Oxide Dispersions: “Soggy Sand” Electrolytes
Authors: Bhattacharyya Aninda J.
Published: April 2012

Review: 46 refs.
ChemInform Abstract: Synthesis of Heterocycles by Palladium‐Catalyzed Intramolecular Heteroarylation
Authors: Tymoshenko Dmytro , Jeges Gyorgy , Gregg Brian T.
Published: April 2012

Review: 135 refs.
ChemInform Abstract: Recent Advances in the Chemistry of Thienoazoles
Authors: El‐Saghier Ahmed M. , Abdel‐Ghany Hossam , Mohamed Mounir A. , Younes Sabry H.
Published: April 2012

Review: 75 refs.
ChemInform Abstract: Evaluating the “Greenness” of Chemical Processes and Products in the Pharmaceutical Industry — A Green Metrics Primer
Authors: Jimenez‐Gonzalez Concepcion , Constable David J. C. , Ponder Celia S.
Published: April 2012

Review: 66 refs.
ChemInform Abstract: Ionic Liquid Processing of Cellulose
Authors: Wang Hui , Gurau Gabriela , Rogers Robin D.
Published: April 2012

Review: 142 refs.
ChemInform Abstract: The Importance of Green Chemistry in Process Research and Development
Authors: Dunn Peter J.
Published: April 2012

Review: 65 refs.
Optimal energy consumption in refrigeration systems ‐ modelling and non‐convex optimisation
Authors: Hovgaard Tobias Gybel , Larsen Lars F. S. , Skovrup Morten J. , Jørgensen John Bagterp
Published: April 2012

Supermarket refrigeration consumes substantial amounts of energy. However, due to the thermal capacity of the refrigerated goods, parts of the cooling capacity delivered can be shifted in time without deteriorating the food quality. In this study, we develop a realistic model for the energy consumption in super market refrigeration systems. This model is used in a Nonlinear Model Predictive Controller (NMPC) to minimise the energy used by operation of a supermarket refrigeration system. The model is non‐convex and we develop a computational efficient algorithm tailored to this problem that is somewhat more efficient than general purpose optimisation algorithms for NMPC and still near to optimal. Since the non‐convex cost function has multiple extrema, standard methods for optimisation cannot be directly applied. A qualitative analysis of the system's constraints is presented and a unique minimum within the feasible region is identified. Following that finding we propose a tailored minimisation procedure that utilises the nature of the feasible region such that the minimisation can be separated into two linear programs; one for each of the control variables. These subproblems are simple to solve but some iterations might have to be performed in order to comply with the maximum capacity constraint. Finally, a nonlinear solver is used for a small example without separating the optimisation problem, and the results are compared to the outcome of our proposed minimisation procedure for the same conceptual example. The tailored approach is somewhat faster than the general optimisation method and the solutions obtained are almost identical. © 2012 Canadian Society for Chemical Engineering
Leaching kinetics of copper flotation tailings in aqueous ammonia/ammonium carbonate solution
Authors: You‐Cai Liu , Wei Yang , Jian‐Gang Fu , Li‐Feng Li , Dong Qian
Published: April 2012

The experiments of agitation leaching were carried out in aqueous ammonia/ammonium carbonate solution, to recover copper from the flotation tailings of waste copper oxide residue. The main copper minerals contained in the flotation tailings are chrysocolla, malachite, and cuprite, with the copper grade of 1.12%. Effects of lixiviant concentration, solid‐to‐liquid ratio, stirring speed, and reaction temperature on copper leaching ratios at various time were investigated. It is found that the leaching ratio almost cannot be affected by time after 90 min of leaching. The optimised processing conditions have been determined, under which the leaching ratio of 70.6% is obtained. Kinetics analysis indicates that the copper leaching ratio is controlled by diffusion through the product layer in the initial 60 min of leaching, and corresponding measures to strengthen the copper extraction is proposed, with the activation energy of 32.3 kJ/mol. © 2012 Canadian Society for Chemical Engineering
PH sensitive structural uniformity of rice husk ash‐derived MCM‐41 silica
Authors: Teabpinyok Nopporn , Chareonpanich Metta , Samingprai Sutheerawat , Limtrakul Jumras
Published: April 2012

In this study, highly uniform MCM‐41 mesoporous silica was synthesised from rice husk ash‐derived sodium silicate using cetyltrimethyl ammonium chloride (CTAC) as a template. The chemical composition of the gel mixture was based on a SiO2:CTAC:H2O molar ratio of 1:0.5:75. When the pH value was initially controlled at ranges of 5.0–10.5 for 5 h and then immediately adjusted to 11.25 for the next 1 h, the structural uniformity of MCM‐41 was abruptly increased by 3.3–7.5 times of the single pH value at 11.25, respectively. Moreover, thermal and hydrothermal stabilities at 900 and 250°C were clearly observed. © 2012 Canadian Society for Chemical Engineering
Study of droplet behaviour along a pulsed liquid–liquid extraction column in the presence of nanoparticles
Authors: Khoobi Nafiseh , Bahmanyar Amir , Molavi Hoda , Bastani Dariush , Mozdianfard Mohammad Reza , Bahmanyar Hossein
Published: April 2012

In this article, droplet size and its distribution along a pulsed liquid–liquid extraction column, is studied where SiO2 nanoparticles with concentrations of 0.01, 0.05 and 0.1 vol.% and different hydrophobicities are applied to the dispersed phase. Using ultrasonication, nanoparticles were dispersed in kerosene as the base fluid. Nanofluids' stability was ensured using a UV–vis spectrophotometer. Some 22,000 droplets were measured by photographic technique and results were compared with systems containing no‐nanoparticles (Water–Acetic acid–Kerosene). Addition of nanoparticles changed the droplet shape from ellipsoidal to spherical. Also, there was a marked influence on droplet breakage and droplet coalescence at 0.01 vol.%, and 0.05 vol.% or higher volume fractions, respectively. © 2012 Canadian Society for Chemical Engineering
Connections of the lateral hypothalamic area juxtadorsomedial region in the male rat
Authors: Hahn Joel D. , Swanson Larry W.
Published: April 2012

Neuronal connections of the lateral hypothalamic area juxtadorsomedial region (LHAjd) were visualized and mapped to a series of rat brain reference templates following an LHAjd coinjection of Phaseolus vulgaris leucoagglutinin (yellow lines) and cholera toxin B subunit (yellow dots) tracers. At the transverse level shown, anterograde axonal labeling is prominent in dorsal (d) and ventrolateral (vl) divisions of the periaqueductal gray (PAG); retrograde labeling is abundant in the hippocampal formation, in the pyramidal cell layer of the intermediate subiculum (SUB‐sp). Approximate injection site location and section level are indicated (respectively) by the red dot and line in the cartoon inset. AQ = cerebral aqueduct proper; CLI = caudal linear nucleus, raphé ec = external capsule; MRNm/RR = midbrain reticular nucleus, magnocellular part / retrorubral area; SCig.a–c/dg = superior colliculus, intermediate gray layer, sublayer a–c / deep gray layer; scp = superior cerebellar peduncle; VTA = ventral tegmental area. The Journal of Comparative Neurology, Volume 520, Number 9, pages 1831–1890.
Organization and metamorphosis of glia in the Drosophila visual system
Authors: Edwards Tara N. , Nuschke Andrea C. , Nern Aljoscha , Meinertzhagen Ian A.
Published: April 2012

The visual system of Drosophila is an excellent model for determining the interactions that direct the differentiation of the nervous system's many unique cell types. Glia are essential not only in the development of the nervous system, but also in the function of those neurons with which they become associated in the adult. Given their role in visual system development and adult function we need to both accurately and reliably identify the different subtypes of glia, and to relate the glial subtypes in the larval brain to those previously described for the adult. We viewed driver expression in subsets of larval eye disc glia through the earliest stages of pupal development to reveal the counterparts of these cells in the adult. Two populations of glia exist in the lamina, the first neuropil of the adult optic lobe: those that arise from precursors in the eye‐disc/optic stalk and those that arise from precursors in the brain. In both cases, a single larval source gives rise to at least three different types of adult glia. Furthermore, analysis of glial cell types in the second neuropil, the medulla, has identified at least four types of astrocyte‐like (reticular) glia. Our clarification of the lamina's adult glia and identification of their larval origins, particularly the respective eye disc and larval brain contributions, begin to define developmental interactions which establish the different subtypes of glia. J. Comp. Neurol. 520:2067–2085, 2012. © 2012 Wiley Periodicals, Inc.
Proton Crystallization in a Dense Hydrogen Plasma
Authors: Filinov V. S. , Bonitz M. , Fehske H. , Fortov V. E. , Levashov P. R.
Published: April 2012

We perform a first‐principle analysis of Coulomb crystallization in neutral two‐component mass asymmetric plasmas by large‐scale path integral Monte Carlo simulations for a dense hydrogen plasma in a broad density range. We observe two large jumps in the relative distance fluctuations of protons that are connected with qualitative changes in the behavior of the proton pair distribution function and are attributed to the formation of a spatially ordered state. A third smaller jump inside the ordered phase indicates a structural transition (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Collective Modes in Strongly Coupled Binary Liquids
Authors: Kalman G.J. , Donkó Z. , Hartmann P. , Golden K.I. , Kyrkos S.
Published: April 2012

We analyze the collective excitations in two‐ and three‐dimensional binary Yukawa systems, consisting of two components with different masses. Theoretical analysis reveals a profound difference between the weakly and strongly correlated limits: at weak coupling the two components interact via the mean field only and the oscillation frequency is governed by the light component. In the strongly correlated limit the mode frequency is governed by the combined mass, where the heavy component dominates. Computer simulations in the full coupling range extend and confirm the theoretical results (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phylogeographic insights into an irruptive pest outbreak
Authors: Cullingham Catherine I. , Roe Amanda D. , Sperling Felix A. H. , Coltman David W.
Published: April 2012

Irruptive forest insect pests cause considerable ecological and economic damage, and their outbreaks have been increasing in frequency and severity. We use a phylogeographic approach to understand the location and progression of an outbreak by the MPB (Dendroctonus ponderosaeHopkins), an irruptive bark beetle that has caused unprecedented damage to lodgepole pine forests in western North America and is poised to expand its range across the boreal forest. We sampled MPB populations across British Columbia and Alberta and used phylogeographic methods to describe lineage diversification, characterize population structure, investigate expansion dynamics, and identify source populations of the outbreak. Using 1181 bp of mitochondrial DNA sequence from 267 individuals, we found high haplotype diversity, low nucleotide diversity, and limited lineage diversification. The overall pattern was consistent with isolation by distance at a continental scale, and with reduced diversity and population structure in the northerly, outbreak regions. Post‐Pleistocene expansion was detected, however more recent expansion signals were not detected, potentially due to the size and rapid rate of range expansion. Based on the limited genetic structure, there were likely multiple source populations in southern British Columbia, although the magnitude of the demographic expansion and rate of spread have obscured the signature of these source populations. Our data highlight the need for caution in interpreting phylogeographic results for species with similar demographics.
Cytip regulates dendritic‐cell function in contact hypersensitivity
Authors: Heib Valeska , Sparber Florian , Tripp Christoph H. , Ortner Daniela , Stoitzner Patrizia , Heufler Christine
Published: April 2012

Cytohesin‐interacting protein (Cytip) is induced during dendritic cell (DC) maturation and in T cells upon activation. It has also been shown to be involved in the regulation of immune responses. Here, we evaluated the functional consequences of Cytip deficiency in DCs using Cytip knockout (KO) mice. No difference in DC subpopulations in the skin draining lymph nodes (LNs) was found between Cytip KO mice and their wild‐type counterparts, excluding a role in DC development. To investigate the function of Cytip in DCs in vivo, we used 2,4,6‐trinitrochlorobenzene (TNCB)‐induced contact hypersensitivity (CHS) as a model system. In the sensitization as well as in the elicitation phase, DCs derived from Cytip KO mice induced an increased inflammatory reaction indicated by more pronounced ear swelling. Furthermore, IL‐12 production was increased in Cytip KO bone marrow‐derived DCs (BMDCs) after CpG stimulation. Additionally, Cytip‐deficient DCs loaded with ovalbumin induced stronger proliferation of antigen‐specific CD4+ and CD8+ T cells in vitro. Finally, migration of skin DCs was not altered after TNCB application due to Cytip deficiency. Taken together, these data suggest a suppressive function for Cytip in mouse DCs in limiting immune responses.
PACSIN1 regulates the TLR7/9‐mediated type I interferon response in plasmacytoid dendritic cells
Authors: Esashi Eiji , Bao Musheng , Wang Yi‐Hong , Cao Wei , Liu Yong‐Jun
Published: April 2012

Plasmacytoid dendritic cells (pDCs) are the professional interferon (IFN)‐producing cells of the immune system. pDCs specifically express Toll‐like receptor (TLR)7 and TLR9 molecules and produce massive amounts of type I IFN by sensing microbial nucleic acids via TLR7 and TLR9. Here we report that protein kinase C and casein kinase substrate in neurons (PACSIN) 1, is specifically expressed in human and mouse pDCs. Knockdown of PACSIN1 by short hairpin RNA (shRNA) in a human pDC cell line significantly inhibited the type I IFN response of the pDCs to TLR9 ligand. PACSIN1‐deficient mice exhibited normal levels of conventional DCs and pDCs, demonstrating that development of pDCs was intact although PACSIN1‐deficient pDCs showed reduced levels of IFN‐α production in response to both cytosine guanine dinucleotide (CpG)‐oligonucleotide (ODN) and virus. In contrast, the production of proinflammatory cytokines in response to those ligands was not affected in PACSIN1‐deficient pDCs, suggesting that PACSIN1 represents a pDC‐specific adaptor molecule that plays a specific role in the type I IFN signaling cascade.
Fulfilling the dream: tolerogenic dendritic cells to treat multiple sclerosis
Authors: Gross Catharina C. , Jonuleit Helmut , Wiendl Heinz
Published: April 2012

Autoimmune diseases including multiple sclerosis (MS) are the result of an imbalanced immune tolerance network. Dendritic cells (DCs) are key players in both initiating immunity (immunogenic DCs) and regulating immune responses (tolerogenic DCs = tolDCs) and are potential targets for the treatment of MS. While the immunogenic potential of DCs in fighting infection and cancer has been well established, approaches that exploit their tolerogenic features to promote transplantation tolerance and autoimmunity have emerged only more recently. TolDCs usually maintain antigen‐specific T‐cell tolerance either directly by inducing anergy, apoptosis, or phenotype skewing or indirectly by induction of regulatory T (Treg) cells. The use of ex vivo‐generated tolDCs is an experimental approach to achieve tolerance towards myelin‐antigen‐specific CD4+ T cells. In the article by Raϊch‐Regué and colleagues (Eur. J. Immunol. 2011. 42:772‐783) in this issue of the European Journal of Immunology, advances in human tolDC preparation and promise for autologous therapy are described. These findings raise hopes of achieving the "ideal" of a highly‐specific, causally‐oriented immune intervention for central nervous system (CNS) autoimmunity in MS. However, recent experience with antigen‐specific immune interventions in MS and some general caveats associated with cell‐based‐therapies highlight the challenges for clinical translation of the "immunologist's dream" of treating autoimmunity as discussed in this Commentary.