bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct Synthesis of Boron‐Protected Alkenyl‐ and Alkylborons via Copper‐Catalyzed Formal Hydroboration of Alkynes and Alkenes
Authors: Yoshida Hiroto , Takemoto Yuki , Takaki Ken 
Published: September 2014

AbstractFormal hydroboration of internal alkynes proceeds regio‐ and stereoselectively by the use of a diboron reagent masked with 1,8‐diaminonaphthalene (dan) in the presence of readily available [(Ph3P)3CuCl], leading to direct formation of diverse B‐protected alkenylborons in high yield. The B(dan) moiety can also be efficiently installed into the CC double bond of alkenes to afford the respective alkylborons.
A Method for Evaluating the Level of Soluble β‐Amyloid(1–40/1–42) in Alzheimer’s Disease Based on the Binding of Gelsolin to β‐Amyloid Peptides
Authors: Yu Yanyan , Zhang Lin , Li Chenglin , Sun Xiaoyu , Tang Daoquan , Shi Guoyue 
Published: September 2014

AbstractIn the present work, a new electrochemical strategy for the sensitive and specific detection of soluble β‐amyloid Aβ(1–40/1–42) peptides in a rat model of Alzheimer’s disease (AD) is described. In contrast to previous antibody‐based methods, β‐amyloid(1–40/1–42) was quantified based on its binding to gelsolin, a secretory protein present in the cerebrospinal fluid (CSF) and plasma. The level of soluble β‐amyloid peptides in the CSF and various brain regions were found with this method to be lower in rats with AD than in normal rats.
Ein selbstorganisierter supramolekularer ternärer Komplex zur magnetischen Trennung von Proteinen
Authors: Samanta Avik , Ravoo Bart Jan 
Published: September 2014

AbstractFür die Proteomik ist die einfache und effiziente Isolierung von Proteinen aus einer Mischung essenziell. Wir beschreiben hier einen supramolekularen Ansatz, um selektiv Proteine aus einer Proteinmischung einzufangen und mithilfe eines Magnetfeldes auszufällen. Dies geschieht durch die Bildung eines multivalenten selbstorganisierten Komplexes aus einer verdünnten Lösung der folgenden drei Komponenten: Cyclodextrin‐beschichtete magnetische Nanopartikel, Adamantan‐ und Kohlenhydrat‐funktionalisierte nichtkovalente Vernetzer und Lectine. Der selbstorganisierte ternäre Komplex wird im Magnetfeld ausgefällt und kann durch die Zugabe eines konkurrierenden Bindungspartners leicht wieder in Lösung gebracht werden. Wir zeigen, dass dieser supramolekulare Ansatz zur Aufreinigung von Proteinen mithilfe magnetischer Extraktion hoch selektiv und effizient erfolgt.
Polymer‐Induced Surface Modifications of Pd‐based Thin Films Leading to Improved Kinetics in Hydrogen Sensing and Energy Storage Applications
Authors: Ngene Peter , Westerwaal Ruud J. , Sachdeva Sumit , Haije Wim , de Smet Louis C. P. M. , Dam Bernard 
Published: September 2014

AbstractThe catalytic properties of Pd alloy thin films are enhanced by a thin sputtered PTFE coating, resulting in profound improvements in hydrogen adsorption and desorption in Pd‐based and Pd‐catalyzed hydrogen sensors and hydrogen storage materials. The remarkably enhanced catalytic performance is attributed to chemical modifications of the catalyst surface by the sputtered PTFE leading to a possible change in the binding strength of the intermediate species involved in the hydrogen sorption process.
Selektive Inhibition des Immunoproteasoms durch ligandeninduzierte Vernetzung des katalytischen Zentrums
Authors: Dubiella Christian , Cui Haissi , Gersch Malte , Brouwer Arwin J. , Sieber Stephan A. , Krüger Achim , Liskamp Rob M. J. , Groll Michael 
Published: September 2014

AbstractDas Konzept der Proteasom‐Inhibition zählt zu den jüngsten Errungenschaften der Blutkrebstherapie und stellt eine vielversprechende Strategie zur Regulierung von Autoimmunerkrankungen dar. Diese Arbeit beschreibt die selektive Hemmung der katalytischen β5‐Untereinheit des Immunoproteasoms durch peptidische Sulfonylfluoride, die nur geringen zytotoxischen Effekt haben. Strukturelle und massenspektrometrische Analysen offenbarten einen neuartigen Inhibitionsmechanismus, der zu einer Umpolung und irreversiblen Vernetzung des proteasomalen aktiven Zentrums führt. Hierdurch identifizierten wir die Sulfonylfluorid‐Kopfgruppe für die Weiterentwicklung von Immunoproteasom‐spezifischen Verbindungen und ihren möglichen Einsatz zur Behandlung von Autoimmunerkrankungen.
Directional Photomanipulation of Breath Figure Arrays
Authors: Wang Wei , Du Can , Wang Xiaofan , He Xiaohua , Lin Jiaping , Li Lei , Lin Shaoliang 
Published: September 2014

AbstractPorous polymeric films are of paramount importance in many areas of modern science and technology. However, processing methods typically based on direct writing, imprint, and lithography techniques have low throughput and are often limited to specific fabricated shapes. Herein, we demonstrate the directional photomanipulation of breath figure arrays (BFAs) formed by an azobenzene‐containing block copolymer to address the aforementioned problems. Under the irradiation of linearly polarized light, the round pores in the BFAs were converted to rectangular, rhombic, and parallelogram‐shaped pores in 30 min, due to the anisotropic mass migration based on the photo‐reconfiguration of the azobenzene units. Through a secondary irradiation after rotating the sample by 90°, the transformed pores were apparently recovered. Therefore, this non‐contacted, directional photomanipulation technique in conjunction with breath figure processing opens a new route to nano/microporous films with finely tuned features.
Atomic Layer Deposition Overcoating: Tuning Catalyst Selectivity for Biomass Conversion
Authors: Zhang Hongbo , Gu Xiang‐Kui , Canlas Christian , Kropf A. Jeremy , Aich Payoli , Greeley Jeffrey P. , Elam Jeffrey W. , Meyers Randall J. , Dumesic James A. , Stair Peter C. , Marshall Christopher L. 
Published: September 2014

AbstractThe terraces, edges, and facets of nanoparticles are all active sites for heterogeneous catalysis. These different active sites may cause the formation of various products during the catalytic reaction. Here we report that the step sites of Pd nanoparticles (NPs) can be covered precisely by the atomic layer deposition (ALD) method, whereas the terrace sites remain as active component for the hydrogenation of furfural. Increasing the thickness of the ALD‐generated overcoats restricts the adsorption of furfural onto the step sites of Pd NPs and increases the selectivity to furan. Furan selectivities and furfural conversions are linearly correlated for samples with or without an overcoating, though the slopes differ. The ALD technique can tune the selectivity of furfural hydrogenation over Pd NPs and has improved our understanding of the reaction mechanism. The above conclusions are further supported by density functional theory (DFT) calculations.
Chiral Palladacycle Catalysts Generated on a Single‐Handed Helical Polymer Skeleton for Asymmetric Arylative Ring Opening of 1,4‐Epoxy‐1,4‐dihydronaphthalene
Authors: Yamamoto Takeshi , Akai Yuto , Suginome Michinori 
Published: September 2014

AbstractPost‐polymerization CH activation of poly(quinoxaline‐2,3‐diyl)‐based helically chiral phosphine ligands (PQXphos) with palladium(II) acetate afforded chiral phosphapalladacycles quantitatively. In situ generated palladacycles exhibited enantioselectivities up to 94 % ee in the palladium‐catalyzed asymmetric ring‐opening arylation of 1,4‐epoxy‐1,4‐dihydronaphthalenes with arylboronic acids.
[2+2]‐Photocycloaddition von 3‐Alkenyloxy‐2‐cycloalkenonen: enantioselektive Lewis‐Säure‐Katalyse und Ringerweiterung
Authors: Brimioulle Richard , Bach Thorsten 
Published: September 2014

AbstractDurch Verwendung substöchiometrischer Mengen (50 Mol‐%) einer chiralen Lewis‐Säure ist es gelungen, die intramolekulare [2+2]‐Photocycloaddition der Titelverbindungen mit hoher Enantioselektivität (bis zu 94 % ee) zu realisieren. Die resultierenden tricyclischen Produkte unterziehen sich im sauren Milieu einer Ringerweiterungsreaktion, in deren Verlauf der Cyclobutanring gespalten wird und racemisierungsfrei anellierte Sieben‐ oder Achtringe gebildet werden. Die Ringerweiterung kann unter BF3‐Katalyse mit einer diastereoselektiven Reduktion (Triethylsilan) oder Allylübertragung (Allyltrimethylsilan) kombiniert werden (48–87 % Ausbeute).
Ultrahigh Energy Density Realized by a Single‐Layer β‐Co(OH)2 All‐Solid‐State Asymmetric Supercapacitor
Authors: Gao Shan , Sun Yongfu , Lei Fengcai , Liang Liang , Liu Jiawei , Bi Wentuan , Pan Bicai , Xie Yi 
Published: September 2014

AbstractA conceptually new all‐solid‐state asymmetric supercapacitor based on atomically thin sheets is presented which offers the opportunity to optimize supercapacitor properties on an atomic level. As a prototype, β‐Co(OH)2 single layers with five‐atoms layer thickness were synthesized through an oriented‐attachment strategy. The increased density‐of‐states and 100 % exposed hydrogen atoms endow the β‐Co(OH)2 single‐layers‐based electrode with a large capacitance of 2028 F g−1. The corresponding all‐solid‐state asymmetric supercapacitor achieves a high cell voltage of 1.8 V and an exceptional energy density of 98.9 Wh kg−1 at an ultrahigh power density of 17 981 W kg−1. Also, this integrated nanodevice exhibits excellent cyclability with 93.2 % capacitance retention after 10 000 cycles, holding great promise for constructing high‐energy storage nanodevices.
Bowl‐like SnO2@Carbon Hollow Particles as an Advanced Anode Material for Lithium‐Ion Batteries
Authors: Liang Jin , Yu Xin‐Yao , Zhou Han , Wu Hao Bin , Ding Shujiang , Lou Xiong Wen (David) 
Published: September 2014

AbstractDespite the great advantages of hollow structures as electrodes for lithium‐ion batteries, one apparent common drawback which is often criticized is their compromised volumetric energy density due to the introduced hollow interior. Here, we design and synthesize bowl‐like SnO2@carbon hollow particles to reduce the excessive hollow interior space while retaining the general advantages of hollow structures. As a result, the tap density can be increased about 30 %. The as‐prepared bowl‐like SnO2@carbon hollow particles with conformal carbon support exhibit excellent lithium storage properties in terms of high capacity, stable cyclability and excellent rate capability.
A Carbene‐Rich but Carbonyl‐Poor [Ir6(IMe)8(CO)2H14]2+ Polyhydride Cluster as a Deactivation Product from Catalytic Glycerol Dehydrogenation
Authors: Campos Jesús , Sharninghausen Liam S. , Crabtree Robert H. , Balcells David 
Published: September 2014

AbstractThe title cluster, a deactivation product in the catalytic dehydrogenation of glycerol, was characterized by XRD, DFT calculations, HRMS, FTIR spectroscopy, and NMR spectroscopy. Experimental/computational studies located the 14 H ligands, and all 1H and 13C{1H} NMR resonances were assigned. The structure contains an unprecedented Ir6H14 core with two CO and eight IMe ligands.
Processive Catalysis
Authors: van Dongen Stijn F. M. , Elemans Johannes A. A. W. , Rowan Alan E. , Nolte Roeland J. M. 
Published: September 2014

AbstractNature’s enzymes are an ongoing source of inspiration for scientists. The complex processes behind their selectivity and efficiency is slowly being unraveled, and these findings have spawned many biomimetic catalysts. However, nearly all focus on the conversion of small molecular substrates. Nature itself is replete with inventive catalytic systems which modify, replicate, or decompose entire polymers, often in a processive fashion. Such processivity can, for example, enhance the rate of catalysis by clamping to the polymer substrate, which imparts a large effective molarity. Reviewed herein are the various strategies for processivity in nature’s arsenal and their properties. An overview of what has been achieved by chemists aiming to mimic one of nature’s greatest tricks is also included.
Magnetic Separation of Proteins by a Self‐Assembled Supramolecular Ternary Complex
Authors: Samanta Avik , Ravoo Bart Jan 
Published: September 2014

AbstractThe easy and effective separation of proteins from a mixture is crucial in proteomics. A supramolecular method is described to selectively capture and precipitate one protein from a protein mixture upon application of a magnetic field. A multivalent complex self‐assembles in a dilute aqueous solution of three components: magnetic nanoparticles capped with cyclodextrin, non‐covalent cross‐linkers with an adamantane and a carbohydrate moiety, and lectins. The self‐assembled ternary complex is precipitated in a magnetic field and readily redispersed with the aid of a non‐ionic surfactant and competitive binding agents. This strategy to purify proteins by supramolecular magnetic precipitation is highly selective and efficient.
Restraint of the Differentiation of Mesenchymal Stem Cells by a Nonfouling Zwitterionic Hydrogel
Authors: Bai Tao , Sun Fang , Zhang Lei , Sinclair Andrew , Liu Sijun , Ella‐Menye Jean‐Rene , Zheng Ying , Jiang Shaoyi 
Published: September 2014

AbstractThe success of human mesenchymal stem cell (hMSC) therapies is largely dependent on the ability to maintain the multipotency of cells and control their differentiation. External biochemical and biophysical cues can readily trigger hMSCs to spontaneously differentiate, thus resulting in a rapid decrease in the multipotent cell population and compromising their regenerative capacity. Herein, we demonstrate that nonfouling hydrogels composed of pure poly(carboxybetaine) (PCB) enable hMSCs to retain their stem‐cell phenotype and multipotency, independent of differentiation‐promoting media, cytoskeletal‐manipulation agents, and the stiffness of the hydrogel matrix. Moreover, encapsulated hMSCs can be specifically induced to differentiate down osteogenic or adipogenic pathways by controlling the content of fouling moieties in the PCB hydrogel. This study examines the critical role of nonspecific interactions in stem‐cell differentiation and highlights the importance of materials chemistry in maintaining stem‐cell multipotency and controlling differentiation.
Selective Transcription of an Unnatural Naphthyridine:Imidazopyridopyrimidine Base Pair Containing Four Hydrogen Bonds with T7 RNA Polymerase
Authors: Nomura Yusaku , Kashiwagi Satoshi , Sato Kousuke , Matsuda Akira 
Published: September 2014

AbstractThe naphthyridine:imidazopyridopyrimidine base pair is the first base pair containing four hydrogen bonds that can be replicated selectively and efficiently by the use of DNA polymerases. Herein we describe the synthesis of naphthyridine‐C‐ribonucleoside 5′‐triphosphate (rNaTP) and transcription reactions catalyzed by T7 RNA polymerase with rNaTP and template DNA containing imidazopyridopyrimidine. The transcription reaction was also applied to a longer transcript containing part of the human c‐Ha‐Ras gene.
Selective Inhibition of the Immunoproteasome by Ligand‐Induced Crosslinking of the Active Site
Authors: Dubiella Christian , Cui Haissi , Gersch Malte , Brouwer Arwin J. , Sieber Stephan A. , Krüger Achim , Liskamp Rob M. J. , Groll Michael 
Published: September 2014

AbstractThe concept of proteasome inhibition ranks among the latest achievements in the treatment of blood cancer and represents a promising strategy for modulating autoimmune diseases. In this study, we describe peptidic sulfonyl fluoride inhibitors that selectively block the catalytic β5 subunit of the immunoproteasome by inducing only marginal cytotoxic effects. Structural and mass spectrometric analyses revealed a novel reaction mechanism involving polarity inversion and irreversible crosslinking of the proteasomal active site. We thus identified the sulfonyl fluoride headgroup for the development and optimization of immunoproteasome selective compounds and their possible application in autoimmune disorders.
Preparation of a low‐phosphorous terpolymer as a scale, corrosion inhibitor, and dispersant for ferric oxide
Authors: Chen Yiyi , Zhou Yuming , Yao Qingzhao , Bu Yunyun , Wang Huchuan , Wu Wendao , Sun Wei 
Published: September 2014

ABSTRACTA novel low‐phosphorus terpolymer, used as scale, corrosion inhibitor, and dispersant for iron oxide, was prepared through free‐radical polymerization reaction of acrylic acid (AA), oxalic acid‐allypolyethoxy carboxylate (APEM), and phosphorous acid (H3PO3) in water with redox system of hypophosphorous and ammonium persulfate as initiator. Structure of the synthesized AA‐APEM‐H3PO3 terpolymer was characterized by Fourier transform infrared spectrometer and 1H‐NMR. The polymer possesses excellent scale inhibition performance for CaCO3, outstanding ability to disperse ferric oxide, and good corrosion inhibition properties. The study showed that AA‐APEM‐H3PO3 exhibited excellent ability to control calcium carbonate scale, with approximately 90.16% CaCO3 inhibition at a level of 8 mg/L AA‐APEM‐H3PO3. The data of the light transmittance showed that, compared to hydrolyzed polymaleic acid and polyepoxysuccinic acid, AA‐APEM‐H3PO3 had superior ability to control iron ions scaling. The light transmittance of the solution was about 24.1% in the presence of the terpolymer when the dosage was 8 mg/L. Moreover, the corrosion inhibition efficiency could reach up to 79.77% at a dosage of 30 mg/L, with ethylene diamine tetra methylene phosphonic acid just 39.62%. Scanning electronic microscopy, transmission electron microscope, and X‐ray powder diffraction analysis were used to investigate the effect of AA‐APEM‐H3PO3 on morphology of calcium carbonate scale. The low‐phosphorous terpolymer has also been proven to be effective inhibitor of calcium carbonate even at increasing solution temperature, pH, and Ca2+ concentration. The proposed inhibition mechanism suggests the surface complexation and chelation between the functional groups P(O) (OH)2, COOH and Ca2+, with polyethylene glycol segments increasing its solubility in water. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41447.
Electrical, mechanical, structural, and thermal behaviors of polymeric gel electrolyte membranes of poly(vinylidene fluoride‐co‐hexafluoropropylene) with the ionic liquid 1‐butyl‐3‐methylimidazolium tetrafluoroborate plus lithium tetrafluoroborate
Authors: Shalu  , Chaurasia Sujeet Kumar , Singh Rajendra Kumar , Chandra Suresh 
Published: September 2014

ABSTRACTPolymeric gel electrolyte membranes based on the polymer poly(vinylidene fluoride‐co‐hexafluoropropylene) [P(VdF–HFP)] with different weight percentages of the ionic liquid (IL) 1‐butyl‐3‐methylimidazolium tetrafluoroborate plus 0.3M lithium tetrafluoroborate (LiBF4) salt were prepared and characterized by scanning electron microscopy, X‐ray diffraction, differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared (FTIR) spectroscopy, complex impedance spectroscopy, pulse echo techniques, and Vickers hardness (H) testing. After the incorporation of the IL plus the salt solution in the P(VdF–HFP) polymer, the melting temperature, glass‐transition temperature (Tg), degree of crystallinity, thermal stability, elastic modulus (E), and hardness (H) gradually decreased with increasing content of the IL–salt solution as a result of complexation between the P(VdF–HFP) and IL. This was confirmed by FTIR spectroscopy. A part of the IL and LiBF4 were found to remain uncomplexed as well. The ionic conductivity (σ) of the polymeric gel membranes was found to increase with increasing concentration of the IL–salt solution. The temperature‐dependent σs of these polymeric gel membranes followed an Arrhenius‐type thermally activated behavior. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41456.
Sugarcane bagasse ash as a reinforcing filler in thermoplastic elastomers: Structural and mechanical characterizations
Authors: Ozório Maiza da Silva , Reis Elton Aparecido Prado dos , Teixeira Silvio Rainho , Bellucci Felipe Silva , Job Aldo Eloizo 
Published: September 2014

ABSTRACTThe incorporation of residues as reinforcing fillers in polymer composites has emerged as a viable solution, enabling improvements in the mechanical properties of these materials, and has also resulted in a reduction in the cost of the final product. In this work, sugarcane bagasse ash (SBA) was used as a reinforcing filler in comparison with commercial silica (CS) in thermoplastic elastomers prepared from the compatibility of low‐density polyethylene (LDPE) with natural rubber (NR). The composites were obtained by a physical mixture of LDPE and NR with different proportions of CS and SBA using a Haake rotational rheometer. The samples were analyzed by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and tensile testing. The results show that SBA has similar properties to CS, thus making its use feasible as a reinforcing filler in thermoplastic elastomers. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41466.
Rewritable Multilevel Memory Performance of a Tetraazatetracene Donor–Acceptor Derivative with Good Endurance
Authors: Wang Chengyuan , Hu Benlin , Wang Jiangxin , Gao Junkuo , Li Gang , Xiong Wei‐Wei , Zou Binghua , Suzuki Mitsuharu , Aratani Naoki , Yamada Hiroko , Huo Fengwei , Lee Pooi See , Zhang Qichun 
Published: September 2014

AbstractA new tetraazatetracene derivative, 2,3‐[4,4′‐bis(N,N‐diphenylamino)benzyl]‐5,12‐bis[(triisopropylsilyl)ethynyl]‐1,4,6,11‐tetraazatetracene (TPAs‐BTTT), displays rewritable multilevel memory behavior, which is probably induced by multielectron intramolecular charge transfer (CT).
Preparation of pH‐stimuli‐responsive PEG–TGA/TGH‐capped CdTe QDs and their application in cell labeling
Authors: Du Yan , Yang Dongzhi , Sun Shian , Zhao Ziming , Tang Daoquan 
Published: September 2014

AbstractA pH‐sensitive and double functional nanoprobe was designed and synthesized in a water‐soluble system using thioglycolic acid (TGA) and mercapto‐acetohydrazide (TGH) as the stabilizers. TGA is biocompatible because the carboxyl group is easily linked to biological macromolecules. At the same time, the hydrazide on TGH reacts with the aldehyde on poly(ethylene glycol) (PEG) and forms a hydrazone bond. The hydrazone bond ruptured at specific pH values and exhibited pH‐stimuli‐responsive characteristics. As an optical imaging probe, the PEG–TGA/TGH‐capped CdTe quantum dots (QDs) had high quality, with a fluorescence efficiency of 25–30%, and remained stable for at least five months. This pH‐responsive factor can be used for the effective release of CdTe QDs under the acidic interstitial extracellular environment of tumor cells. This allows the prepared pH‐stimuli‐responsive nanoprobes to show fluorescence signals for use in cancer cell imaging. Copyright © 2014 John Wiley & Sons, Ltd.
Delivery of Antibody Mimics into Mammalian Cells via Anthrax Toxin Protective Antigen
Authors: Liao Xiaoli , Rabideau Amy E. , Pentelute Bradley L. 
Published: September 2014

AbstractAntibody mimics have significant scientific and therapeutic utility for the disruption of protein–protein interactions inside cells; however, their delivery to the cell cytosol remains a major challenge. Here we show that protective antigen (PA), a component of anthrax toxin, efficiently transports commonly used antibody mimics to the cytosol of mammalian cells when conjugated to the N‐terminal domain of LF (LFN). In contrast, a cell‐penetrating peptide (CPP) was not able to deliver any of these antibody mimics into the cell cytosol. The refolding and binding of a transported tandem monobody to Bcr‐Abl (its protein target) in chronic myeloid leukemia cells were confirmed by co‐immunoprecipitation. We also observed inhibition of Bcr‐Abl kinase activity and induction of apoptosis caused by the monobody. In a separate case, we show disruption of key interactions in the MAPK signaling pathway after PA‐mediated delivery of an affibody binder that targets hRaf‐1. We show for the first time that PA can deliver bioactive antibody mimics to disrupt intracellular protein–protein interactions. This technology adds a useful tool to expand the applications of these modern agents to the intracellular milieu.