bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cobalt Growth on the Tips of CdSe Nanorods
Authors: Maynadié Jérôme , Salant Asaf , Falqui Andrea , Respaud Marc , Shaviv Ehud , Banin Uri , Soulantica Katerina , Chaudret Bruno 
Published: January 2009

AbstractBest of both worlds: Reduction of an organometallic Co precursor on preformed CdSe nanorods yields two distinct semiconducting–magnetic heterostructures (see picture). The selective growth of Co on the tips of CdSe first gives nanosphere–nanorod dimers, which evolve into nanorod–nanorod structures. In the hybrid objects the magnetic properties of Co remain intact, while the luminescence properties of CdSe are affected but not completely quenched.magnified image
Protein Recognition by an Ensemble of Fluorescent DNA G‐Quadruplexes
Authors: Margulies David , Hamilton Andrew D. 
Published: January 2009

AbstractSniffing out proteins: Fluorescent DNA G‐quadruplexes have been used for building versatile signaling receptors for proteins in a single solution. Introducing a protein sample to the ensemble results in a unique emission signature for unambiguous identification (see scheme, R=fluorophore). The self‐assembled, pattern‐based protein detection systems are easily fabricated, have the potential for high‐throughput operations, and have the ability to handle small protein samples.magnified image
Drug Delivery by an Enzyme‐Mediated Cyclization of a Lipid Prodrug with Unique Bilayer‐Formation Properties
Authors: Linderoth Lars , Peters Günther H. , Madsen Robert , Andresen Thomas L. 
Published: January 2009

AbstractSpecial delivery: Liposomal drug‐delivery systems in which prodrugs are activated specifically by disease‐associated enzymes have great potential for the treatment of severe diseases, such as cancer. A new type of phospholipid‐based prodrug has the ability to form stable small unilamellar vesicles (see picture). Activation of the prodrug vesicles by the enzyme sPLA2 initiates a cyclization reaction, which leads to the release of the drug.magnified image
Catalytic, Enantioselective Ring Opening of Aziridines
Authors: Schneider Christoph 
Published: January 2009

AbstractCooperative metal centers in a bimetallic catalyst facilitate the highly enantioselective ring opening of meso aziridines 1 with silyl nucleophiles (see scheme; TMS=trimethylsilyl). The 1,2‐azidoamides 2 and 1,2‐amidonitriles 3 obtained in this way in high yields and with up to 99 % ee are valuable precursors to enantiomerically pure 1,2‐diamines and β‐amino acids.magnified image
Highly Proton‐Conducting Self‐Humidifying Microchannels Generated by Copolymer Brushes on a Scaffold
Authors: Yameen Basit , Kaltbeitzel Anke , Langer Andreas , Müller Frank , Gösele Ulrich , Knoll Wolfgang , Azzaroni Omar 
Published: January 2009

AbstractFilling in the gaps: Macroporous silicon membranes modified with sulfonated polymer brushes have been synthesized by pore‐filling surface polymerization (see picture) to give proton‐conducting channels with tailor‐made, finely tuned physicochemical characteristics. These membranes display high conductivity values (ca. 10−2 S cm−1) regardless of the humidity, thus surpassing the performance of nafion.magnified image
Responsive Supramolecular Gels Constructed by Crown Ether Based Molecular Recognition
Authors: Ge Zhishen , Hu Jinming , Huang Feihe , Liu Shiyong 
Published: January 2009

AbstractResponsive supramolecular gels were constructed from crown ether terminated four‐arm star poly(ε‐caprolactone) (PCL–DB24C8) and dibenzylammonium‐terminated two‐arm PCL–DBAS (see scheme), exploiting the formation of pseudorotaxane linkages between crown ether and ammonium moieties. The resultant supramolecular gels exhibit thermo‐ and pH‐induced reversible gel–sol transition.magnified image
Exploiting the Divergent Reactivity of Aryl–Palladium Intermediates for the Rapid Assembly of Fluorene and Phenanthrene Derivatives
Authors: Zhao Ya‐Bin , Mariampillai Brian , Candito David A. , Laleu Benoît , Li Mengzhou , Lautens Mark 
Published: January 2009

AbstractThey all fall down: The value of domino processes can be greatly enhanced when the possibility exists for one to selectively diverge from a common intermediate. In preliminary studies the dual reactivity of aryl–palladium intermediates is exploited. A diverse array of fluorene and phenanthrene derivatives were synthesized in a rapid and efficient manner (see scheme).magnified image
Fast Biosynthesis of GFP Molecules: A Single‐Molecule Fluorescence Study
Authors: Katranidis Alexandros , Atta Diaa , Schlesinger Ramona , Nierhaus Knud H. , Choli‐Papadopoulou Theodora , Gregor Ingo , Gerrits Michael , Büldt Georg , Fitter Jörg 
Published: January 2009

AbstractIt's not easy being green: Real‐time visualization of labeled ribosomes and de novo synthesized green fluorescent protein molecules using single‐molecule‐sensitive fluorescence microscopy demonstrates that the mutant GFPem is produced with a characteristic time of five minutes. Fluorescence of the fastest GFP molecules appears within one minute (see picture).magnified image
Cover Picture: Microcontainers with Fluorescent Anisotropic Zeolite L Cores and Isotropic Silica Shells (Angew. Chem. Int. Ed. 7/2009)
Authors: Guerrero‐Martínez Andrés , Fibikar Sandra , Pastoriza‐Santos Isabel , Liz‐Marzán Luis M. , De Cola Luisa 
Published: January 2009

AbstractNanocontainers composed of zeolite L crystals were filled with fluorescent dyes and used as the core of a silica “box‐in‐a‐box” construction as in Russian matryoshka dolls, as described by A. Guerrero‐Martínez, L. de Cola, and co‐workers in their Communication on page 1266 ff. The anisotropic cores and isotropic shells of the multicolor emitting systems are separated by a polyelectrolyte layer and can be addressed independently. This approach opens fascinating routes for the construction of multifunctional nanosystems.magnified image
Inside Cover: Self‐Assembly of One‐ and Two‐Dimensional Hemoprotein Systems by Polymerization through Heme–Heme Pocket Interactions (Angew. Chem. Int. Ed. 7/2009)
Authors: Kitagishi Hiroaki , Kakikura Yasuaki , Yamaguchi Hiroyasu , Oohora Koji , Harada Akira , Hayashi Takashi 
Published: January 2009

AbstractSupramolecular protein polymers consisting of cytochrome b562 monomers with heme covalently attached to the protein surface are presented by T. Hayashi and co‐workers in their Communication on page 1271 ff. Not only one‐dimensional hemoprotein fibers with submicrometer lengths have been prepared, but when a heme triad was added as a pivot molecule, two‐dimensional protein assembly networks resulted, which cover over 100 square micrometers.magnified image
Effect of hot air aging on the properties of ethylene‐vinyl acetate copolymer and ethylene‐acrylic acid copolymer blends
Authors: Chen Shuangjun , Zhang Jun , Su Jun 
Published: January 2009

AbstractThe aim of this investigation is to evaluate the effect of hot air aging on properties of ethylene‐vinyl acetate copolymer (EVA, 14 wt % vinyl acetate units), ethylene‐acrylic acid copolymer (EAA, 8 wt % acrylic acid units), and their blends. Attenuated total reflection‐Fourier transform infrared spectroscopy, differential scanning calorimeter (DSC), wide angle X‐ray diffraction, and mechanical tests are employed to investigate the changes of copolymer blends' structures and properties. Increase of carbonyl index derived from ATR measurements with aging time suggests the incorporation of oxygen into the polymeric chain. By DSC measurements, the enthalpy at low temperature endothermic peak (Tm2) of EAA becomes less and disappears after 8 weeks aging, but enthalpy at Tm2 of EVA is not influenced by the hot air aging and remains stable despite of the aging time. For various proportions of EAA and EVA blends, enthalpy at Tm2 decreases as the EAA proportion increases when aging time is 8 weeks; after several weeks of hot air aging, the various blends appear a same new peak just over the aging temperature 70°C which is due to the completion of crystals which are not of thermodynamic equilibrium state. Mechanical tests show that increase of crystallinity and hot air aging deterioration both have influence on the hardness, tensile strength, and elongation at break. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Chain extension reactions of unsaturated polyesters with epoxy compounds
Authors: Taylan E. , Küsefoğlu S. H. 
Published: January 2009

AbstractUnsaturated polyesters (UPE) were chain extended with three different epoxy group containing compounds. The molecular weight increase was monitored using gel permeation chromatography (GPC). The polymers obtained were characterized by FTIR and 1H NMR, and styrene solubility and gel time. The polyesters were then diluted with styrene and cured with a radical initiator and compared with a commercial reference polyester. Thermal and mechanical properties of the cured polyesters were characterized by dynamic mechanical analysis (DMA) and thermal gravimetric analysis (TGA). The results show that UPE can be chain extended with epoxy containing compounds which substantially shortens the condensation polymerization during manufacture, without compromising their thermal and mechanical properties. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Mechanisms of molecular interactions in polybase–polyacid complex formed by copolymers of N,N‐dimethylaminoethylmethacrylate with alkylmethacrylates and methacrylic acid with ethylacrylate
Authors: Feldstein Mikhail M. , Kiseleva Tatiana I. , Bondarenko Galina N. , Kostina Julia V. , Singh Parminder , Cleary Gary W. 
Published: January 2009

AbstractMechanisms of molecular interaction in the blends of a polybase, a copolymer of N,N‐dimethylaminoethylmethacrylate with methylmethacrylate and butylmethacrylate (PDMAEMA–MMA/BMA), with a polyacid, a copolymer of methacrylic acid with ethylacrylate (PMAA‐co‐EA), and plasticizer, triethylcitrate (TEC), have been investigated with FTIR Spectroscopy and potentiometry. To evaluate the strengths of hydrogen and ionic bonds in the polyelectrolyte complexes, quantum‐chemical calculations were performed. According to this analysis, the energy of ionic and hydrogen bonding diminishes in the order: multi‐component complexes involving protonated aminogroup of DMAEMA (ammonium cation) in the presence of chlorine counterion with ionized or unchanged carboxyl groups and water molecules (690–520 kJ/mol) > ternary H‐bonded acid‐base complexes associated with molecule of water (520–420 kJ/mol) > binary ionic complex of carboxylate anion and ammonium cation (404 kJ/mol) > H‐bonded complex of carboxylate and ammonium ions (257 kJ/mol) > binary H‐bonded complex of uncharged carboxyl group with ammonium cation (114 kJ/mol) > ternary H‐bonded complex of uncharged carboxyl group, aminogroup and water molecule (43 kJ/mol) > binary H‐bonded complex between nonionized carboxyl and amino groups (26 kJ/mol). Proton‐donating capability of functional groups in the studied polyelectrolyte blends diminishes in the order: HN+(CH3)2 − > HOOC > HO. The proton‐donating capacity can be significantly improved in the presence of Cl− ions, the effect of which may be appreciably inhibited if Na+ cations are available in the blend or solution. Proton‐accepting capability weakens in the order: uncharged aminogroup > carboxylate anion > uncharged carboxyl group > hydroxyl group. The results of quantum chemical calculations facilitate interpretation of FTIR spectra. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Thermal and mechanical properties of cast polyurethane resin based on soybean oil
Authors: Wang Chengshuang , Yang Liting , Ni Baolian , Wang Linyun 
Published: January 2009

AbstractThe soy polyols were prepared from epoxidation of soybean oil followed by ring opening of oxirane obtained by using methanol as the ring opener. Polyols of hydroxyl (OH) numbers ranging from 128 to 174 mg of KOH/g were obtained by the variation of epoxidation time of soybean oil. A novel cast polyurethane resin has been synthesized by these polyols and 2,4‐toluene diisocyanate. Swelling of networks in toluene showed that the sol fraction varies from 1.13 to 72.06%. The thermal and mechanical properties of cast resins were characterized by differential scanning calorimetry and thermogravimetric analysis. The results showed that the glass transition temperature increases with the increase of OH number and that the thermal stability of the resins was slightly decreased with the increasing OH number. The tensile strength at break increases with the increase of OH number. Polyols with OH number of 174 mg of KOH/g gave glassy polymers, whereas those below this value gave rubbers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Combined effect of shear and nucleating agent on the multilayered structure of injection‐molded bar of isotactic polypropylene
Authors: Cao Jing , Wang Ke , Cao Wen , Zhang Qin , Du RongNi , Fu Qiang 
Published: January 2009

AbstractMolten polymers are usually exposed to varying levels of shear flow and temperature gradient in most processing operations. Many studies have revealed that the crystallization and morphology are significantly affected under shear. A so‐called “skin‐core” structure is usually formed in injection‐molded semicrystalline polymers such as isotactic polypropylene (iPP) or polyethylene (PE). In addition, the presence of nucleating agent has great effect on the multilayered structure formed during injection molding. To further understand the morphological development in injection‐molded products with nucleating agent, iPP with and without dibenzylidene sorbitol (DBS) were molded via both dynamic packing injection molding (DPIM) and conventional injection molding. The structure of these injection‐molded bars was investigated layer by layer via SEM, DSC, and 2 days‐WAXD. The results indicated that the addition of DBS had similar effect on the crystal size and its distribution as shear, although the later decreased the crystal size more obviously. The combination of shear and DBS lead to the formation of smaller spherulites with more uniform size distribution in the injection‐molded bars of iPP. A high value of c‐axis orientation degree in the whole range from the skin to the area near the core center was obtained in the samples molded via DPIM with or without DBS, while in samples obtained via conventional injection molding, the orientation degree decreased gradually from the skin to the core and the decreasing trend became more obvious as the concentration of DBS increased. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and In‐Vitro Cytotoxicity Evaluation of Novel Naphtindolizinedione Derivatives, Part II: Improved Activity for Aza‐Analogues
Authors: Defant Andrea , Guella Graziano , Mancini Ines 
Published: January 2009

AbstractOur previous investigation on potential antitumor agents now got enriched by the evaluation of in‐vitro activity against a full panel of NCI cancer cell lines for five new compounds. The concurrent presence in the molecular structure of a nitrogen atom in the aromatic system and a N,N‐dimethylaminoethyl amide chain play a decisive role to enhance cytotoxicity. The N,N‐anti compound 14 shows a higher activity than its N,N‐syn isomer, exhibiting the best selective inhibition against the melanoma MALME‐3M cell line, with a GI50‐value (= 30 nM) corresponding to a 330‐fold increase in activity compared to the corresponding deaza‐analogue. Compound 14 is efficiently synthesized by aminolysis of the ester obtained as a single regio‐isomer by an one‐pot three‐component procedure involving metal‐assisted cyclization under microwave irradiation conditions.
Context recognition for hierarchical text classification
Authors: Liu Rey‐Long 
Published: January 2009

AbstractInformation is often organized as a text hierarchy. A hierarchical text‐classification system is thus essential for the management, sharing, and dissemination of information. It aims to automatically classify each incoming document into zero, one, or several categories in the text hierarchy. In this paper, we present a technique called CRHTC (context recognition for hierarchical text classification) that performs hierarchical text classification by recognizing the context of discussion (COD) of each category. A category's COD is governed by its ancestor categories, whose contents indicate contextual backgrounds of the category. A document may be classified into a category only if its content matches the category's COD. CRHTC does not require any trials to manually set parameters, and hence is more portable and easier to implement than other methods. It is empirically evaluated under various conditions. The results show that CRHTC achieves both better and more stable performance than several hierarchical and nonhierarchical text‐classification methodologies.
Total Synthesis of (−)‐Spirangien A, an Antimitotic Polyketide Isolated from the Myxobacterium Sorangium Cellulosum
Authors: Paterson Ian , Findlay Alison D. , Noti Christian 
Published: January 2009

AbstractA stereocontrolled total synthesis of the cytotoxic spiroacetal‐containing polyketide (−)‐spirangien A is described. This utilizes an aldol‐based strategy to construct a common stereotetrad intermediate that was elaborated into the spiroacetal core, followed by the introduction of the unstable pentaene‐containing side chain, performed with exclusion of light, using sequential Stille cross‐coupling reactions.magnified imageAn expedient first total synthesis of (−)‐spirangien A, a potent cytotoxic and antifungal polyketide of myxobacterial origin, is described. By using a common 1,3‐diol intermediate obtained by an efficient aldol‐reduction sequence for installation of the C15–C18 and C25–C28 stereotetrads and a reagent‐controlled boron aldol coupling followed by spiroacetalization, a highly convergent strategy was developed for construction of the elaborate spiroacetal core. Conversion of this advanced spiroacetal intermediate into (+)‐spirangien diene, obtained previously by controlled degradation of spirangien A, was then achieved by installation of the truncated side‐chain using an allylboration–Peterson sequence. The total synthesis of (−)‐spirangien A was then achieved by the controlled attachment of the unsaturated C1–C12 side‐chain, avoiding exposure to light. A Stork–Wittig olefination and double Stille cross‐coupling sequence was exploited to install the delicate conjugated pentaene chromophore featuring alternating (Z)‐ and (E)‐olefins, leading initially to the methyl ester of spirangien A, which proved significantly more stable than the corresponding free acid. Subsequent careful hydrolysis afforded (−)‐spirangien A, validating the relative and absolute configuration.
Translation and rotation movements of the mandible during mouth opening and closing
Authors: Mapelli Andrea , Galante Domenico , Lovecchio Nicola , Sforza Chiarella , Ferrario Virgilio F. 
Published: January 2009

AbstractTo assess the relative contribution of rotation and translation of the temporomandibular condyle‐disc assembly during opening and closing movements, free movements of maximum mouth opening and closing were recorded in healthy subjects (12 men, 14 women) using an optoelectronic three‐dimensional motion analyzer. For each subject, the displacement of the lower interincisal point, the path of the condylar reference point, the degree of rotation around the three orthogonal rotational axes, and the relative contribution of translation and rotation were calculated during all movement of mouth opening and closing. The distance covered by the interincisor point and the rotational angle about the transverse axis at maximum mouth opening were larger in men than in women, but the difference cancelled after correcting for mandibular radius in the sagittal plane; mandibular rotation was always larger than translation, but never approaching 100%; opening and closing translations were similar within sex, but their paths were longer in men than in women (P < 0.05); rotational angles around vertical and sagittal axes were negligible; the linear correlation between maximum mandibular opening and condylar translation was minor and not significant. In normal subjects, mouth opening and closing as modeled at the interincisor point was determined more by mandibular rotation than by translation, but in no occasion a pure rotation was found. The percentage rotation was not identical during mouth opening and closing; female and male paths were not totally coincident; no correlation between maximum mandibular opening and condylar translation was found. Clin. Anat. 22:311–318, 2009. © 2009 Wiley‐Liss, Inc.
Improvements in power system transient simulation by application of trigonometric trapezoidal rule
Authors: Hosseinian S. H. 
Published: January 2009

AbstractThis article describes a user‐friendly simulation program for teaching and modeling power system transient and power quality issues. The main reason for the development of the program is to provide students with a useable tool for gaining an intuitive feel for power system transient and power quality problems. Emphasis was consistently laid on the development, validation and application of software for transient studies. To this end the primary focus of the research was the development of a generally oriented program in the form of a single module which is able to simulate any arbitrary configuration of power system in the time domain. Apart from the main program, sub‐programs have been developed to derive the required data for transmission line, transformer, machine and other equipment parameters. A novel variety of trapezoidal integration (called trigonometric) has been used, it has accuracy and therefore speed advantages over ordinary trapezoidal integration. This method is compared with ordinary trapezoidal integration, backward Euler, Gear second order and Simpson. The comparison is based upon the error and the performance of each method as differentiator. At each step, the variables associated with the switches are checked and if any constraints are violated, the process backtracks to the time when the violation occurred and the node voltages and branch currents are calculated for this time instant. In order to reduce the simulation time the program accepts the branch currents and node voltages as initial conditions which allow the steady state to be reached in less time. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 277–289, 2010; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20253
Domestic violence against women: Understanding social processes and women's experiences
Authors: Bostock Jan , Plumpton Maureen , Pratt Rebekah 
Published: January 2009

AbstractThe prevalence of domestic abuse against women has been estimated as high as one in four. The risk is particularly high for women who are younger, economically dependent, unemployed and with children. Research about the factors that maintain situations of abuse has generally focused separately on the coping strategies of women, barriers to leaving the relationship and the perpetrators' means of abuse. In this study we used a community psychology perspective to seek a broader understanding of what maintains situations of abuse, in order to suggest interventions in a rural County in the North of England. Twelve women who had experienced domestic abuse and had used voluntary sector services agreed to be interviewed about their experiences and the resources and strategies available to them. Using grounded theory we generated four themes: (1) Commonalities and contradictions in the experience of abuse; (2) living with abuse; (3) the response of systems reinforced or challenged the abuse and (4) dealing with abuse beyond the relationship. These findings illustrate how situations of domestic abuse can be prolonged by limited options available to victims for support and protection, and a lack of active public acknowledgement that domestic abuse is unacceptable. Copyright © 2009 John Wiley & Sons, Ltd.