bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vertical structure of medium‐scale traveling ionospheric disturbances
Authors: Ssessanga Nicholas , Kim Yong Ha , Kim Eunsol 
Published: October 2015

AbstractWe develop an algorithm of computerized ionospheric tomography (CIT) to infer information on the vertical and horizontal structuring of electron density during nighttime medium‐scale traveling ionospheric disturbances (MSTIDs). To facilitate digital CIT we have adopted total electron contents (TEC) from a dense Global Positioning System (GPS) receiver network, GEONET, which contains more than 1000 receivers. A multiplicative algebraic reconstruction technique was utilized with a calibrated IRI‐2012 model as an initial solution. The reconstructed F2 peak layer varied in altitude with average peak‐to‐peak amplitude of ~52 km. In addition, the F2 peak layer anticorrelated with TEC variations. This feature supports a theory in which nighttime MSTID is composed of oscillating electric fields due to conductivity variations. Moreover, reconstructed TEC variations over two stations were reasonably close to variations directly derived from the measured TEC data set. Our tomographic analysis may thus help understand three‐dimensional structure of MSTIDs in a quantitative way.
The Art of Drawing
Authors: Carpo Mario 
Published: October 2015

AbstractToday, architecture is inextricably linked with drawing. Drawing and representation are generally regarded as the core skills of the professional architect. Architectural theorist and historian Mario Carpo challenges the notion that architecture has to necessarily be an art of drawing. He reminds us that the architect, as a maker of drawings, is in fact a fairly recent cultural and technical phenomenon ‐ only emerging in early 15th‐century Italy. Could, then, the digital revolution of the last 20 years be starting to challenge the drawing's hegemony?
Palladium‐Catalyzed Asymmetric Ring Opening Reaction of Azabenzonorbornadienes with Aromatic Amines
Authors: Lu Zhiwu , Wang Jun , Han Baiqiu , Li Sifeng , Zhou Yongyun , Fan Baomin 
Published: October 2015

AbstractA palladium/(R)‐Binap catalyst for asymmetric ring opening reaction of azabenzonorbornadienes with amines was developed that afforded the corresponding substituted dihydronaphthalenes in good yields (up to 97%) with excellent enantioselectivities (up to >99% ee). To the best of our knowledge, this represents the first palladium‐catalyzed asymmetric ring opening reaction of azabenzonorbornadienes with heteronucleophiles.magnified image
Preparation of Chitosan‐g‐Poly(l‐Lactic Acid) Copolymer
Authors: Cui Yuan , Zhang Jingpeng , Zhang Wei , Duan Qian 
Published: October 2015

ABSTRACTAlthough poly (l‐lactic acid) (PLLA) is used as tissue engineering scaffold to implant in vivo, secondary inflammation will be induced by the lactic acid enrichment in short period during the PLLA implant degradation. To dissolve the problem, the chitosan (CS), a typical polyaminosaccharide is introduced to neutralize the acetic acid when the scaffold is degraded in vivo. First, the active amino groups of CS are protected by excess phthalic anhydride. Then, the ring‐opening polymerization of lactide onto phthaloyl‐protected CS could be performed without the addition of a catalyst. Finally, the product is deprotected by hydrazine hydrate to give chitosan‐g‐poly (l‐lactic acid) (CS‐g‐PLLA). The structure of CS‐g‐PLLA copolymer is characterized by infrared spectrum and 1H nuclear magnetic resonance. When CS is introduced on PLLA, the solution of the degraded copolymer ceased to be acidic. In addition, CS‐g‐PLLA shows excellent solubility in some organic solvent for the easier tissue engineering scaffold preparation.
Alkene‐Directed N‐Attack Chemoselectivity in the Gold‐Catalyzed [2+2+1]‐Annulations of 1,6‐Enynes with N‐Hydroxyanilines
Authors: Huple Deepak B. , Mokar Bhanudas D. , Liu Rai‐Shung 
Published: October 2015

AbstractKinetically unstable nitrones are generated from gold‐catalyzed reactions of 1,6‐enynes with N‐hydroxyanilines, and subsequently trapped by tethered alkenes to furnish [2+2+1]‐annulations. Our experimental data reveal that such nitrones arise from atypical N‐attack chemoselectivity that is triggered by tethered alkenes to facilitate the key protodeauration reaction.
Catalysis of Radical Reactions: A Radical Chemistry Perspective
Authors: Studer Armido , Curran Dennis P. 
Published: October 2015

AbstractThe area of catalysis of radical reactions has recently flourished. Various reaction conditions have been discovered and explained in terms of catalytic cycles. These cycles rarely stand alone as unique paths from substrates to products. Instead, most radical reactions have innate chains which form products without any catalyst. How do we know if a species added in “catalytic amounts” is a catalyst, an initiator, or something else? Herein we critically address both catalyst‐free and catalytic radical reactions through the lens of radical chemistry. Basic principles of kinetics and thermodynamics are used to address problems of initiation, propagation, and inhibition of radical chains. The catalysis of radical reactions differs from other areas of catalysis. Whereas efficient innate chain reactions are difficult to catalyze because individual steps are fast, both inefficient chain processes and non‐chain processes afford diverse opportunities for catalysis, as illustrated with selected examples.
Reversible Supramolecular Surface Attachment of Enzyme–Polymer Conjugates for the Design of Biocatalytic Filtration Membranes
Authors: Moridi Negar , Corvini Philippe F.‐X. , Shahgaldian Patrick 
Published: October 2015

AbstractTo be used successfully in continuous reactor systems, enzymes must either be retained using filtration membranes or immobilized on a solid component of the reactor. Whereas the first approach requires large amounts of energy, the second approach is limited by the low temporal stability of enzymes under operational conditions. To circumvent these major stumbling blocks, we have developed a strategy that enables the reversible supramolecular immobilization of bioactive enzyme–polymer conjugates at the surface of filtration membranes. The polymer is produced through a reversible addition–fragmentation transfer method; it contains multiple adamantyl moieties that are used to bind the resulting conjugate at the surface of the membrane which has surface‐immobilized cyclodextrin macrocycles. This supramolecular modification is stable under operational conditions and allows for efficient biocatalysis, and can be reversed by competitive host–guest interactions.
Direct Access to Multifunctionalized Norcamphor Scaffolds by Asymmetric Organocatalytic Diels–Alder Reactions
Authors: Mose Rasmus , Jensen Magnus E. , Preegel Gert , Jørgensen Karl Anker 
Published: October 2015

AbstractA general organocatalytic cross‐dienamine activation strategy to produce chiral multifunctionalized norcamphor compounds having a large diversity in substitution pattern is presented. The strategy is based on a Diels–Alder reaction of an amino‐activated cyclopentenone reacting with most common classes of electron‐deficient olefins, such as nitro‐, ester‐, amide‐, and cyano‐substituted olefins, chalcones, conjugated malononitriles, CF3‐substituted enones, and fumarates. The corresponding norcamphor derivatives are formed in good yield, excellent enantioselectivities, and with complete diastereoselectivity. Furthermore, it is demonstrated that quaternary stereocenters and spiro norcamphor compounds can be formed with high stereoselectivity. The present development provides a simple, direct, and efficient approach for the preparation of important norcamphor scaffolds.
Asymmetric Pentafulvene Carbometalation—Access to Enantiopure Titanocene Dichlorides of Biological Relevance
Authors: Cini Melchior , Bradshaw Tracey D. , Woodward Simon , Lewis William 
Published: October 2015

AbstractUnprecedented asymmetric copper‐catalyzed addition of ZnEt2 (ZnBu2) to the exocyclic CC bond of pentafulvenes C5H4(CHAr) (Ar=2‐MeOPh and related species) results in enantiomerically enriched (up to 93:7 e.r.) cyclopentadienyl ligands (C5H4CHEtAr; abbreviated CpR). Copper catalyst promotion with both chiral phosphoramidite ligands and a phosphate additive is vital in realizing both acceptable enantioselectivities and reaction rates. Enantiomeric CpR2TiCl2 complexes have been prepared; the (S,S) isomer is twice as active towards pancreatic, breast, and colon cancer cell lines as its (R,R) enantiomer at 24 h.
Destruction and Construction: Application of Dearomatization Strategy in Aromatic Carbon–Nitrogen Bond Functionalization
Authors: Wang Shuo‐En , Wang Linfei , He Qiuqin , Fan Renhua 
Published: October 2015

AbstractThe formation of carbon–carbon bonds through the functionalization of aromatic carbon–nitrogen bonds is a highly attractive synthetic strategy in the synthesis of aromatic molecules. In this paper, we report a novel aromatic carbon–nitrogen bond functionalization reaction by using a simple dearomatization strategy. Through this process para‐substituted anilines serve as a potential aryl source in the construction of a range of functionalized aromatic molecules, such as quaternary carbon centers, α‐keto esters, and aldehydes.
Spatially resolved monitoring of crystalline suprastructure and molecular orientation in α‐ and β‐nucleated polypropylene pipes using differential scanning calorimetry, infrared microscopy, and polarized light microscopy
Authors: Schuster Tobias , Rode Karsten , Brüll Robert , Heinemann Jürgen , Haupt Hansgeorg 
Published: October 2015

ABSTRACTDifferently nucleated polypropylene (PP) pipes were studied by polarized light and infrared (IR) microscopy and differential scanning calorimetry (DSC). Although Fourier transform IR microscopy (µFTIR) excels by high spatial resolution and ease of measurement over the classical approach with manually prepared sections and individual analysis, a disadvantage is that the vibrational bands used to calculate the degree of crystallinity may be influenced by the polymorphism of PP. While this does not play a role for the α‐polymorph, in the case of β‐nucleated PP the calculated profile of crystallinity derived from the so called crystallinity bands depends on the direction of inspection. We could show that in the case of β‐nucleation the results from µFTIR and DSC of cross‐sections can be correlated, and thus the crystallinity profile obtained from µFTIR becomes independent from the direction of consideration. Consequently the advantages of µFTIR with regard to spatial resolution and reproducibility can now be exploited for β‐nucleated PP as well. Using the differently nucleated specimen we give the first practical validation of a previously on a theoretical basis derived model to determine the molecular orientation in all three dimensions (machine, transverse, and normal). It could be shown that the profiles of molecular orientation are a function of both, the extrusion process with its post extrusion cooling conditions, and the type of nucleating agent. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4182–4190, 2013
Maximum Reduced Proper Motion method: Detection of new nearby ultracool dwarfs
Authors: Phan‐Bao N. 
Published: October 2015

AbstractIn this paper, we describe how to use the Maximum Reduced Proper Motion method (Phan‐Bao et al. 2003) to detect 57 nearby L and late‐M dwarfs (dphot ≤ 30 pc), 36 of them newly discovered. Spectroscopic observations of 43 of the 57 ultracool dwarfs were previously reported in Martín et al. (2010). These ultracool dwarfs were identified by color criteria in ∼5000 square degrees of the DENIS database and then further selected by the method for spectroscopic follow‐up to determine their spectral types and spectroscopic distances. We also report here our newly measured proper motions of these ultracool dwarfs from multi‐epoch images found in public archives (ALADIN, DSS, 2MASS, DENIS), with at least three distinct epochs and time baselines of 2 to 46 years (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
ArgR–promoter interactions in Corynebacterium glutamicum arginine biosynthesis
Authors: Theron Grant , Reid Sharon J. 
Published: October 2015

AbstractArginine biosynthesis in Corynebacterium glutamicum is currently poorly understood. A better understanding of its regulation will aid in the engineering of overproducing strains. A transcriptional analysis of the argCJBDFRGH genes and construction of argR deletion mutant confirmed the role of ArgR as a negative regulator of arginine biosynthesis. Increasing the copy number of the argC promoter region caused arginine levels to increase twofold. Electrophoretic mobility shift assays using recombinant ArgR revealed in vitro binding with dissociation constants between 200 and 250 nM to the putative promoter regions of argC and carAB. In contrast, ArgR did not bind in vitro to the putative argG promoter region. Binding of ArgR to the argC and carA promoter regions was prevented by double‐stranded competitor oligonucleotides containing motifs resembling the universal ARG box consensus sequence (two in the case of the argC promoter region and one in the case of the carA promoter region). A single ARG box was identified in the carA promoter region. The consensus sequence for the three C. glutamicum ARG box motifs was 5′‐HMT GMA TSW ADW WTW TDY‐3′ and the core sequence (underlined) is well conserved throughout the C. glutamicum genome and located preceding several putative ArgR targets.
Soluble expression of human Id3 in Escherichia coli and generation and application of its polyclonal antibodies
Authors: Li Xiao‐Jun , Jia Li , Chen Fang‐Fang , Zhong Ai‐Fang , Yu Wei , Wang Kai , Luo Bing 
Published: October 2015

AbstractInhibitor of DNA binding differentiation 3 (Id3), a member of the Id helix–loop–helix protein family, plays important roles in cell differentiation, cell cycle control, and apoptosis. In the present study, the human Id3 (hId3) gene was amplified by polymerase chain reaction and inserted into prokaryotic expression vector pET32a(+). The recombinant plasmid pET32a/hId3 was transformed into Escherichia coli BL21 (DE3). The histidine–Tag‐fused protein was expressed by induction of 1 mM isopropylthio‐β‐d‐galactoside and purified by Ni2+–nitrilotriacetic acid–agarose column chromatography. The purified hId3 protein was used to generate rabbit polyclonal antisera that recognize recombinant hId3 (rhId3). The antibody was purified by polypeptide affinity chromatography and used for analysis of Id3 subcellular localization in several kinds of tumor cells by indirect immunofluoresence assay. A large quantity of purified rhId3 protein and polyclonal anti‐hId3 antibodies would be useful reagents for the further study of biological functions of hId3.
Removal of bacterial suspension water occupying the intercellular space of detached leaves after agroinfiltration improves the yield of recombinant hemagglutinin in a Nicotiana benthamiana transient gene expression system
Authors: Fujiuchi Naomichi , Matsuda Ryo , Matoba Nobuyuki , Fujiwara Kazuhiro 
Published: October 2015

ABSTRACTThe use of detached leaves instead of whole plants provides an alternative means for recombinant protein production based on Agrobacterium tumefaciens‐mediated transient gene overexpression. However, the process for high‐level protein production in detached leaves has not yet been established. In this study, we focused on leaf handling and maintenance conditions immediately after infiltration with Agrobacterium suspension (agroinfiltration) to improve recombinant protein expression in detached Nicotiana benthamiana leaves. We demonstrated that the residual water of bacterial suspension in detached leaves had significant impact on the yield of recombinant influenza hemagglutinin (HA). Immediately after agroinfiltration, detached leaves were stored in a dehumidified chamber to allow bacterial suspension water occupying intercellular space to be removed by transpiration. We varied the duration of this water removal treatment from 0.7 to 4.4 h, which resulted in leaf fresh weights ranging from 0.94 to 1.28 g g−1 relative to weights measured just before agroinfiltration. We used these relative fresh weights (RFWs) as an indicator of the amount of residual water. The detached leaves were then incubated in humidified chambers for 6 days. We found that the presence of residual water significantly decreased HA yield, with a clear inverse correlation observed between HA yield and RFW. We next compared HA yields in detached leaves with those obtained from intact leaves by whole‐plant expression performed at the same time. The maximum HA yield obtained from a detached leaf with a RFW of approximately 1.0, namely, 800 μg gFW−1, was comparable to the mean HA yield of 846 μg gFW−1 generated in intact leaves. Our results indicate the necessity of removing bacterial suspension water from agroinfiltrated detached leaves in transient overexpression systems and point to a critical factor enabling the detached‐leaf system as a viable recombinant protein factory. Biotechnol. Bioeng. 2016;113: 901–906. © 2015 Wiley Periodicals, Inc.
Spannungsfeld Forstwirtschaft und Naturschutz
Authors: Schulze Ernst‐Detlef , Ammer Christian 
Published: October 2015

AbstractDie Arbeit gibt einen Überblick über die zeitliche Entwicklung der Flora in Deutschland mit besonderer Berücksichtigung der an Waldstandorte gebundenen Arten. Die Zahl der Pflanzenarten hat über die Zeit kontinulierlich zugenommen. Dies ist vor allem eine Folge der Landnutzung, durch die auch einige gefährdete Arten erhalten werden. In forstlich bewirtschafteten Wäldern ist der Pflanzenartenvielfalt größer in als in Wäldern unter Naturschutz. Keine der obligaten Waldarten ist in den letzten 250 Jahren durch die Waldbewirtschaftung verloren gegangen. Für Arten mit besonderen Habitat‐Ansprüchen sind alternative Schutzprogramme zu einer Nicht‐Bewirtschaftung nötig, um spezielle Lebensräume zu erhalten.
First Chemical Analysis and Characterization of the Male Species‐Specific Cephalic Labial‐Gland Secretions of South American Bumblebees
Authors: Brasero Nicolas , Martinet Baptiste , Urbanová Klára , Valterová Irena , Torres Alexandra , Hoffmann Wolfgang , Rasmont Pierre , Lecocq Thomas 
Published: October 2015

AbstractThe evolution of signals and reproductive traits involved in the pre‐mating recognition has been in focus of abundant research in several model species, such as bumblebees (genus Bombus). However, the most‐studied bumblebee reproductive trait, the male cephalic labial gland secretions (CLGS), remains unknown among bumblebee species from South America. In this study, the CLGS of five South American bumblebees of the subgenera Thoracobombus (Bombus excellens and B. atratus) and Cullumanobombus (B. rubicundus, B. hortulanus, and B. melaleucus) were investigated, by comparing the chemical compositions of their secretions to those of closely related European species. The results showed an obvious interspecific differentiation in both subgenera. The interspecific differentiation among the species of the Thoracobombus subgenus involved different compounds present at high contents (main compounds), while those of the Cullumanobombus subgenus shared the same main components. This suggests that among the species of the Cullumanobombus subgenus, the differentiation in minor components could lead to species discrimination.
Corrosion Prevention Mechanism of Aluminum Metal in Superconcentrated Electrolytes
Authors: Yamada Yuki , Chiang Ching Hua , Sodeyama Keitaro , Wang Jianhui , Tateyama Yoshitaka , Yamada Atsuo 
Published: October 2015

AbstractThe front cover artwork is provided by Prof. Yamada's group at the University of Tokyo (Japan). The image shows an interface between a superconcentrated electrolyte and an aluminum current collector at a positive electrode in lithium‐ion batteries. Read the full text of the Article at 10.1002/celc.201500235.
Hydrogenated Graphenes by Birch Reduction: Influence of Electron and Proton Sources on Hydrogenation Efficiency, Magnetism, and Electrochemistry
Authors: Eng Alex Yong Sheng , Sofer Zdeněk , Huber Štěpán , Bouša Daniel , Maryško Miroslav , Pumera Martin 
Published: October 2015

AbstractInterest in chemical functionalisation of graphenes today is largely driven by associated changes to its physical and material properties. Functionalisation with hydrogen was employed to obtain hydrogenated graphenes (also termed graphane if fully hydrogenated), which exhibited properties including fluorescence, magnetism and a tuneable band gap. Although the classical Birch reduction has been employed for hydrogenation of graphite oxide, variation exists between the choice of alkali metals and alcohols/water as quenching agents. A systematic study of electron (Li, Na, K, Cs) and proton sources (tBuOH, iPrOH, MeOH, H2O) has been performed to identify optimal conditions. The proton source exerted a great influence on the resulting hydrogenation with water and out‐performed alcohols, and the lowest carbon‐to‐hydrogen ratio was observed with sodium and water with composition of C1.4H1O0.3. Although ferromagnetism at room temperature correlates well with increasing hydrogen concentrations, small contributions from trace iron impurities cannot be completely eliminated. In contrast, hydrogenated graphenes exhibit a significant paramagnetic moment at low temperatures that has no correlation with impurities, and therefore, originates from the carbon system. This is in comparison to graphene, which is strongly diamagnetic, and concentrations of paramagnetic centres in hydrogenated graphenes are one order of magnitude larger than that in graphite. Nonetheless, hydrogenation over a particular level might also excessively disrupt intrinsic sp2 conjugation, resulting in unintended reduction of electrochemical properties. This was observed with heterogeneous electron‐transfer rates and it was postulated that hydrogenated graphenes should generally have high defect densities, but only moderately high hydrogenation, should they be employed as electrode materials.
Enantioselective Preparation, Conformational Analysis and Absolute Configuration of Highly Substituted Aziridines
Authors: Bencivenni Giorgio , Righi Paolo , Lunazzi Lodovico , Ranieri Silvia , Mancinelli Michele , Mazzanti Andrea 
Published: October 2015

AbstractThe first example of organocatalytic aziridination reaction of α‐substituted‐α,β‐unsaturated ketones is presented. The reaction was found to be highly enantio‐ and diastereoselective, yielding N‐tosylated aziridines. Low‐temperature nuclear magnetic resonance (NMR) spectra allowed for the determination of the N‐inversion barrier, that was found to be quite lower with respect to unsubstituted aziridines. A thorough conformational analysis supported by low‐temperature NMR data allowed for the determination of the absolute configuration of the main stereoisomer by means of time‐dependent Density Functional Theory simulation of the electronic circular dichroism spectra. Chirality 27:875–887, 2015. © 2015 Wiley Periodicals, Inc.