bluuebunny/crossref_metadata_2025 huggingface dataset:
ChemInform Abstract: Applications of Computational Chemistry to Designing Materials and Microstructure in Fuel Cell Technologies
Authors: Koyama Michihisa , Kohno Haruhiko , Ogura Teppei , Ishimoto Takayoshi
Published: May 2015

Review: 39 refs.
ChemInform Abstract: Solid‐State Sensors for Carbon Dioxide Detection
Authors: Mandayo G. G. , Herran J.
Published: May 2015

Review: 79 refs.
Tricycloundecane Derivatives as Potential N‐Methyl‐D‐aspartate (NMDA) Receptor and Voltage‐Gated Calcium Channel Modulators
Authors: Egunlusi Ayodeji O. , Malan Sarel F. , Joubert Jacques
Published: May 2015

Neurodegenerative disorders are debilitating conditions characterised by progressive dysfunction and death of neuronal cells. Amidst the proposed mechanisms of neurodegeneration, the effects of excitotoxicity via N‐methyl‐D‐aspartate (NMDA) receptor stimulation and activation of voltage‐gated calcium channels (VGCC) on neuronal cells are prominent. This has led to the development of polycyclic cage molecules such as NGP1‐01, which exhibit neuroprotective properties through NMDA receptor and VGCC modulation. The medicinal potential of structurally related tricycloundecanes that are open‐cage or rearranged polycyclic moieties has not been explored. This study is therefore focused on the synthesis of a series of novel tricycloundecane derivatives and their ability to inhibit NMDA receptors and VGCC. Significant NMDA receptor inhibition was observed for tricyclo[6.2.1.02,7]undec‐9‐ene‐3,6‐dione (4, 78 %) and 6‐hydroxytricyclo[6.2.1.02,7]undec‐9‐en‐3‐one (5, >95 %) at a concentration of 100 μM. The highest inhibitory activity was observed for 6‐(benzylimino)tricyclo[6.2.1.02,7]undec‐9‐en‐3‐one (9, >95 %), which is in the same range as the inhibitory activity of MK‐801 (dizocilpine). In the VGCC inhibition assay, 6‐(benzylamino)tricyclo[6.2.1.02,7]undeca‐4,9‐dien‐3‐one (8, 34 %), 9 (38 %) and 2‐(benzylamino)‐3,6‐epoxytricyclo[6.2.1.05,10]undecan‐9‐ol (12, 40 %) showed statistically significant (p<0.05) VGCC inhibition.
Circuit level simulation of MRI receive chain using excitation derived from images
Authors: Jouda Mazin , Gruschke Oliver G. , Korvink Jan G.
Published: May 2015

We introduce a novel component‐level simulation method with which to characterize the performance of the electronic interfaces and circuitry of a magnetic resonance imaging (MRI) receiver. The Matlab‐based toolbox first reconstructs idealized coil free induction decay signals from real MR images, then uses these signals to drive a transistor‐level and extracted‐layout simulation of the desired receiver architecture. The simulated receiver's outputs are read back into the toolbox, which then reconstructs the MR images. By comparing the reconstructed images with the original ones, important design characteristics, such as the circuit's noise figure, linearity, phase noise, and inter‐channel coupling, can be investigated in terms of image quality. To validate the method, a new MRI receiver architecture is designed and simulated. The architecture is a 16‐channel multiplexer, designed for a commercially available 0.35 μm CMOS technology, and employs both frequency‐division and time‐division multiplexing to form a combined output signal. The SNR degradation and the circuit's linearity determined from the MR images compare well with the SNR and linearity point predictions from conventional circuit simulations. © 2015 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 44B: 102–113, 2015
On the Importance of CH/π and CH⋅⋅⋅HC Interactions in the Solid State Structure of 15‐Lipoxygenase Inhibitors Based on Eugenol Derivatives
Authors: Mirzaei Masoud , Nikpour Mohsen , Bauzá Antonio , Frontera Antonio
Published: May 2015

In this manuscript the X‐ray structures of two potent and known inhibitors of 15‐lipoxygenase, that is, 4‐allyl‐2‐methoxyphenyl‐1‐admantanecarboxylate (1) and allyl‐2‐methoxyphenyl‐1‐cyclohexanecarboxylate (2), are reported. Their solid‐state architectures show that they have a strong ability to establish CH/π and CH⋅⋅⋅HC interactions. For the former interaction, the adamantane or cyclohexane moieties are the CH donors and the electron‐rich methoxyphenyl ring is the π system. For the latter, the CH bonds belong to the aliphatic rings of the inhibitors. Interestingly, the active site of lipoxygenase enzyme family is rich in isoleucine and leucine amino acids that participate in the binding of the unsaturated fatty acid substrate by means of multiple hydrophobic CH⋅⋅⋅HC interactions. By means of theoretical calculations, we analyze the ability of compounds 1 and 2 to establish CH/π and CH⋅⋅⋅HC interactions in the solid state.
A Superhydrophobic Sponge with Hierarchical Structure as an Efficient and Recyclable Oil Absorbent
Authors: Liu Qin , Meng Kai , Ding Kui , Wang Yaobing
Published: May 2015

Oil/water separation is a worldwide challenge due to frequent oil spillages, and high‐performance absorbents are in high demand. In this work, a superhydrophobic sponge was fabricated by the polymerization of aniline, with subsequent simple immersion in n‐dodecylthiol. The polyaniline (PANI) constructed a nanoscale rough surface on the three‐dimension (3D) network of melamine sponge while n‐dodecylthiol reduced surface energy, thus lead to the superhydrophobicity. This superhydrophobic sponge could absorb a broad spectrum of oil and organics efficiently, with the highest 122 times of its own weight absorption capacity. Owing to the strong mechanical elasticity inherited from the pristine melamine sponge and stable adhesion of PANI, this sponge exhibited good recyclability through squeezing. More importantly, the fabrication procedure is facile, low‐cost and easily scalable. Thus, this superhydrophobic sponge is highly promising for absorption oil from water.
Carbon Nanofibers as Advanced Pd Catalyst Supports for the Air Electrode of Alkaline Metal–Air Batteries
Authors: Alegre Cinthia , Modica Esterina , Lo Vecchio Carmelo , Sebastián David , Lázaro María J. , Aricò Antonino S. , Baglio Vincenzo
Published: May 2015

Carbon nanofibers are investigated as a support for Pd catalysts. The electrochemical behavior of these catalysts for both the oxygen reduction and oxygen evolution reactions is investigated in a half‐cell configuration in alkaline solution (6 M KOH) at room temperature. The catalysts are compared with an internal benchmark consisting of Pd supported on Vulcan. Stress tests are also performed to assess the stability of the catalysts under the highly corrosive conditions occurring at the positive electrode, especially during oxygen evolution (high potential). Pd catalysts supported on carbon nanofibers show promising stability characteristics for applications as bifunctional oxygen catalysts in metal–air batteries.
Definitive Insight into the Graphite Oxide Reduction Mechanism by Deuterium Labeling
Authors: Jankovský Ondřej , Šimek Petr , Luxa Jan , Sedmidubský David , Tomandl Ivo , Macková Anna , Mikšová Romana , Malinský Petr , Pumera Martin , Sofer Zdeněk
Published: May 2015

The reduction of graphite oxide is one of the most important reactions in the production of graphene in gram quantities. The mechanisms of these widely used reactions are poorly understood. The mechanism of the chemical reduction of two different graphite oxides prepared by the chlorate (Hofmann method) and permanganate methods (Hummers method) has been investigated. Three different reduction agents, lithium tetrahydridoaluminate, sodium tetrahydridoborate, and lithium tetrahydridoborate, as well as their deuterated counterparts, were used for the reduction of graphite oxide. Reduced graphite oxides were analyzed by scanning electron microscopy, energy‐dispersive spectroscopy, elemental combustion analysis, Raman spectroscopy, high‐resolution X‐ray photoelectron spectroscopy, and simultaneous thermal analysis. The concentration of boron incorporated into graphene was measured by prompt gamma activation analysis. Rutherford back‐scattering spectroscopy and elastic recoil detection analysis were used for the determination of the elemental composition, including deuterium concentration, as evidence of CH bond formation.
3 D Hierarchical Porous Carbon for Supercapacitors Prepared from Lignin through a Facile Template‐Free Method
Authors: Zhang Wenli , Lin Haibo , Lin Zheqi , Yin Jian , Lu Haiyan , Liu Dechen , Zhao Mingzhu
Published: May 2015

Lignin‐derived hierarchical porous carbon (LHPC) was prepared through a facile template‐free method. Solidification of the lignin–KOH solution resulted in KOH crystalizing within lignin. The crystalized KOH particles in solid lignin acted both as template and activating agent in the heat‐treatment process. The obtained LHPC, exhibiting a 3D network, consisted of macroporous cores, mesoporous channels, and micropores. The LHPC comprised 12.27 at % oxygen‐containing groups, which resulted in pseudocapacitance. The LHPC displayed a capacitance of 165.0 F g−1 in 1 M H2SO4 at 0.05 A g−1, and the capacitance was still 123.5 F g−1 even at 10 A g−1. The LHPC also displayed excellent cycling stability with capacitance retention of 97.3 % after 5000 galvanostatic charge–discharge cycles. On account of the facile preparation of LHPC, this paper offers a facile alternative method for the preparation of hierarchical porous carbon for electrochemical energy storage devices.
On the Conductance of the Gas Discharge Plasma at Space Anisotropic Excitation
Authors: Zhechev D. , Steflekova V. , Costello J. T. , Bundaleska N.
Published: May 2015

The galvanic manifestation of two transformations of degenerate magnetic states of the neon atom, namely self‐alignment → non‐alignment and alignment ↔ orientation is studied by monitoring the voltage across the discharge in a range of hollow cathode discharge (HCD) lamps. The application of a magnetic field to the discharge disorders the self‐alignment. Alignment and orientation are optically induced and their effect on the discharge conductance is compared by measuring the optogalvanic signals. The degenerate states investigated are found to contribute to the gas discharge conductance in a manner which depends on their degree of coherence. Various hollow cathode discharge media are studied including Ne/As, Ne/Cu, Ne/Ni, Ne/Cd, Ne/Li and Ne/Ca in the corresponding trademarked HCD spectral lamps. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Consistent, multi‐instrument single tube quantification of CD20 in antibody bound per cell based on CD4 reference
Authors: Degheidy Heba , Abbasi Fatima , Mostowski Howard , Gaigalas Adolfas K. , Marti Gerald , Bauer Steven , Wang Lili
Published: May 2015

Detecting changes in the expression levels of cell antigens could provide critical information for the diagnosis of many diseases, for example, leukemia, lymphoma, and immunodeficiency diseases, detecting minimal residual disease, monitoring immunotherapies and discovery of meaningful clinical disease markers. One of the most significant challenges in flow cytometry is how to best ensure measurement quality and generate consistent and reproducible inter‐laboratory and intra‐laboratory results across multiple cytometer platforms and locations longitudinally over time. In a previous study, we developed a procedure for instrument standardization across four different flow cytometer platforms from the same manufacturer. CD19 quantification was performed on three of the standardized instruments relative to CD4 expression on T lymphocytes with a known amount of antibody bound per cell (ABC) as a quantification standard. Consistent and reliable measures of CD19 expression were obtained independent of fluorochrome used demonstrating the utility of this approach. In the present investigation, quantification of CD20 relative to CD4 reference marker was implemented within a single tube containing both antibodies. Relative quantification of CD20 was performed using anti‐CD20 antibody (clone L27) in three different fluorochromes relative to anti‐CD4 antibody (clone SK3). Our results demonstrated that cell surface marker quantification can be performed robustly using the single tube assay format with novel gating strategies. The ABC values obtained for CD20 expression levels using PE, APC, or PerCP Cy5.5 are consistent over the five different instrument platforms for any given apparently healthy donor independent of the fluorochrome used. © 2015 International Clinical Cytometry Society
β‐Methylphenylethylamines: common fragmentation pathways with amphetamines in electrospray ionization collision‐induced dissociation
Authors: Brown David H. , Hansson Robert , Oosthuizen Francois , Sumner Nathan
Published: May 2015

β‐Methylphenylethylamines are positional isomers of amphetamines and have been discovered in sporting supplements. Although the fragmentation of the β‐methylphenylethylamine and N‐methyl‐β‐methylphenylethylamine in gas chromatography‐electron ionization‐mass spectrometry (GC‐EI‐MS) systems is significantly different to their amphetamine and methylamphetamine isomers, under electrospray ionization commonly used in liquid chromatography‐mass spectrometry (LC‐MS) systems, the fragmentation of each of the isomeric pairs is almost identical. The similarities in fragmentation make it possible for the misidentification of the β‐methylphenylethylamines as the illicit amphetamines. It is proposed that the similarities are due to a fragmentation pathway involving a common phenonium ion intermediate. By careful control of fragmentation energies in liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) systems and/or close examination of the relative abundances of product ions formed by collision‐induced dissociation (qualifier ratios), it is possible to distinguish the β‐methylphenylethylamines from the amphetamines, even if significant retention time separation is not achieved. In liquid chromatography‐electrospray ionization‐quadrupole time of flight (LC‐ESI‐QTOF) systems the mass spectra of the β‐methylphenylethylamines are identical to their amphetamine isomers. In such systems, retention time separation of the isomers is critical to avoid misidentification. During this study β‐methylphenylethylamine and N‐methyl‐β‐methylphenylethylamine have been identified in commercially available sporting supplements and oral fluid samples taken during the course of road‐side drugs‐in‐drivers and workplace testing programmes. Copyright © 2015 John Wiley & Sons, Ltd.
Structure elucidation of the designer drug N‐(1‐amino‐3,3‐dimethyl‐1‐oxobutan‐2‐yl)‐1‐(5‐fluoropentyl)‐3‐(4‐fluorophenyl)‐pyrazole‐5‐carboxamide and the relevance of predicted 13C NMR shifts – a case study
Authors: Girreser Ulrich , Rösner Peter , Vasilev Andrej
Published: May 2015

The detailed structure elucidation process of the new cannabimimetic designer drug, N‐(1‐amino‐3,3‐dimethyl‐1‐oxobutan‐2‐yl)‐1‐(5‐fluoropentyl)‐3‐(4‐fluorophenyl)‐pyrazole‐5‐carboxamide, with a highly substituted pyrazole skeleton, using nuclear magnetic resonance (NMR) spectroscopic and mass spectrometric (MS) techniques is described. After a first analysis of the NMR spectra and comparison with 48 possible pyrazole and imidazole structures, a subset of six positional isomeric pyrazoles and six imidazoles remained conceivable. Four substituents of the heterocyclic skeleton were identified: a proton bound to a pyrazole ring carbon atom; a 5‐fluoropentyl group; a 4‐fluorophenyl substituent; and a carbamoyl group, which is N‐substituted with a methyl residue carrying a tert.‐butyl and a carbamoyl substituent. The 5‐fluoropentyl residue is situated at the nitrogen ring atom. Additional NMR experiments like the 1H,13C HMBC were performed, but due to the small number of signals based on long‐range couplings, the comparison of predicted and observed 13C chemical shifts became necessary. The open access Internet shift prediction programs NMRDB, NMRSHIFTDB2, and CSEARCH were employed for the prediction of 13C shift values which allowed an efficient and unambiguous structure determination. For the identified N‐(1‐amino‐3,3‐dimethyl‐1‐oxobutan‐2‐yl)‐1‐(5‐fluoropentyl)‐3‐(4‐fluorophenyl)‐pyrazole‐5‐carboxamide, the best agreement between predicted 13C shifts and the observed chemical shifts and long‐range couplings for the pyrazole ring carbon atoms, with a standard error of about 2 ppm, was found with each of the predictions. For the comparison of measured and predicted chemical shifts model compounds with simple substituents proved helpful. The identified compound is a homologue of AZ‐037 which is offered by Internet suppliers. Copyright © 2015 John Wiley & Sons, Ltd.
Solvothermal Synthesis of Tetravalent Uranium with Isophthalate or Pyromellitate Ligands
Authors: Falaise Clément , Delille Jason , Volkringer Christophe , Loiseau Thierry
Published: May 2015

Three new coordination polymers bearing tetravalent uranium have been isolated with the O‐donor ligands such as isophthalate (1,3‐bdc) or pyromellitate (btec). The compounds 1 and 3 have been solvothermaly synthesized in N,N‐dimethylformamide (DMF). The crystal structure of U(1,3‐bdc)2(DMF) (1) is built up from discrete tricapped trigonal‐primastic UO9 units, for which one carbonyl oxygen atom from DMF is bound to uranium. The connection of the UO9 units with the isophthalate linkers occurs in a chelating and bidentate fashion and gives rise to the formation of a 3D framework, delimiting narrow channels running along the [101] direction. Upon heating, the DMF molecules are removed, generating the second phase U(1,3‐bdc)2 (2) compound, closely related to 1. Indeed, the coordination environment of uranium is reduced to eight with a distorted square‐antiprismatic geometry. This transition induces the relative shrinkage of the network (ΔV = 23 %). The structure of the compound U(btec)(DMF)2 (3) also exhibits a 3D framework composed of an isolated bicapped square‐antiprismatic UO10 unit, for which two carbonyl oxygen atoms from DMF are bonded to uranium. Pyromellitate ensures the connection of the UO10 units through the carboxylate arms in a chelating mode. This results in the formation of a network with diamond‐shaped channels, developed along the c axis and encapsulating the DMF molecules. In contrast to 1, no stable phase is observed upon removing the DMF species by heating.
Europium‐Based Dinuclear Triple‐Stranded Helicate vs. Tetranuclear Quadruple‐Stranded Helicate: Effect of Stoichiometric Ratio on the Supramolecular Self‐Assembly
Authors: Malviya Amita , Jena Himanshu Sekhar , Mondal Amit Kumar , Konar Sanjit
Published: May 2015

Two europium‐based helicates, namely the dinuclear triple‐stranded helicate [Eu2L3] (1) and tetranuclear quadruple‐stranded helicate [Eu4L4(NO3)]3+ (2), were achieved by the self‐assembly of the succinohydrazone derived bis‐tridentate ligand (H2L) and Eu3+ ions in 1:1 and 1:2 ratios, respectively. Both the helicates were characterized by single‐crystal X‐ray analysis. Structural analysis of both the helicates revealed optically inactive 50:50 mixtures of left‐ (Λ) and right‐hand (Δ) helicates in one unit cell. In 1, both the europium centers lie along the three‐fold axis whereas in 2, four europium centers are arranged in a triangular fashion around the four‐fold axis, which passes through the center of the quadruple stranded helicate. In 2, the presence of a nitrate ion on the nucleation of the aesthetically pleasing tetranuclear quadruple stranded helicate is significant. Apart from the molar ratio, the role of the bridging modes of the ligand, anion and noncovalent interaction on the self‐assembly of two helicates are also discussed.
Synthesis of β‐Trifluoromethylated Ketones from Propargylic Alcohols by Visible Light Photoredox Catalysis
Authors: Park Sehyun , Joo Jung Min , Cho Eun Jin
Published: May 2015

Regioselective trifluoromethylation at a remote position represents an important challenge in the development of biologically active molecules and functional materials. A practical method to access β‐trifluoromethyl ketones from readily available propargylic alcohols by visible light photocatalysis has been developed. Trifluoromethylation of propargylic alcohols with CF3I in the presence of Ru(bpy)3Cl2 as the photocatalyst followed by double‐bond migration/keto‐enol tautomerization provides β‐trifluoromethyl ketones as the final product.
Advancements in Aminofluorination of Alkenes and Alkynes: Convenient Access to β‐Fluoroamines
Authors: Chen Pinhong , Liu Guosheng
Published: May 2015

Direct aminofluorination of alkenes enables the convenient synthesis of β‐fluorinated amine compounds, which are important and valuable skeletons in medicinal chemistry. In recent years this research field has received much attention and significant advancements have been made by different approaches. In this review, recently disclosed methodologies for the production of β‐fluorinated amines, based on electrophilic and metal‐catalyzed processes, are summarized and discussed. Finally, the outlook and perspectives for aminofluorination are also discussed.
Diastereoselective Construction of 3‐Aminooxindoles with Adjacent Stereocenters: Stereocontrolled Addition of γ‐Substituted Allylindiums to Isatin Ketimines
Authors: Aslam Nayyar Ahmad , Babu Srinivasarao Arulananda , Rani Soniya , Mahajan Shivam , Solanki Jagmohan , Yasuda Makoto , Baba Akio
Published: May 2015

The diastereoselective construction of 3‐allyl‐3‐aminooxindoles that have two adjacent stereocenters has been achieved by the In‐promoted Barbier‐type addition of γ‐substituted allylic halides to the C=N bond of isatin ketimines. The reactions of cinnamyl‐, crotyl‐, and geranylindium compounds with isatin ketimines proceeded in either aqueous or alcohol solution. The addition of a cyclohexenylindium species to an isatin ketimine was carried out in N,N‐dimethylformamide (DMF), and the addition of ethyl 4‐bromocrotonate to an isatin ketimine in EtOH gave oxindole‐based β‐amino acid scaffolds. In all of these processes, the reaction conditions were screened to obtain the respective 3‐allyl‐3‐aminooxindoles with very high stereoselectivity. In addition, plausible TS models are proposed, and representative synthetic transformations were carried out by using the oxindole‐based β‐amino acid scaffolds. Furthermore, the stereochemistry of representative compounds were unequivocally established by single‐crystal X‐ray structure analysis.
Intra‐Intermolecular Palladium‐Catalyzed Domino Reactions of Glycine Allylamides for the Synthesis of Diversely Functionalized Piperazinones
Authors: Broggini Gianluigi , Beccalli Egle M. , Borelli Tea , Brusa Filippo , Gazzola Silvia , Mazza Alberto
Published: May 2015

Easily accessible N‐tosylglycine allylamides have been converted into diversely functionalized piperazinone derivatives by inter‐intramolecular oxidative domino palladium‐catalyzed reactions. Aminochlorination and aminoacetoxylation processes were achieved by employing CuCl2 and PhI(OAc)2 as the oxidizing agents to give 5‐chloromethyl‐ and 5‐acetoxymethyl‐substituted piperazinones, respectively.
Synthesis of Functionalized BODIPYs, BODIPY‐Corrole, and BODIPY‐Porphyrin Arrays with 1,2,3‐Triazole Linkers Using the 4‐Azido(tetrafluorophenyl)‐BODIPY Building Block
Authors: Golf Hartwig R. A. , Oltmanns Anna M. , Trieu Duc H. , Reissig Hans‐Ulrich , Wiehe Arno
Published: May 2015

The copper(I)‐catalyzed 1,3‐dipolar cycloaddition of 4‐azido(tetrafluorophenyl)boron‐dipyrrin (azido‐BODIPY) with diverse terminal alkynes, varying from simple alkyl‐substituted derivatives to alkynes with functional groups and carbohydrates, was successfully employed to obtain meso‐functionalized BODIPY derivatives through the 1,2,3‐triazole linkage. The scope of this reaction was extended to the preparation of di‐ and trivalent BODIPY systems through the use of appropriate alkynyl linkers. Moreover, the synthesis of hydroxyl‐ and pentafluorothio‐(SF5)‐substituted, 1,2,3‐triazole‐linked array systems consisting of porphyrins and corroles as the central scaffold, in combination with a BODIPY, was investigated. These covalently connected tetrapyrrole‐BODIPY arrays exemplify a versatile approach to the construction of multichromophore systems: the combination of 1,3‐dipolar cycloaddition and nucleophilic substitution on pentafluorophenyl‐substituted porphyrinoids. The systems designed herein could serve in various light‐harvesting applications and electron‐transfer studies.
Mechanism Switch in Mannich‐Type Reactions: ELF and NCI Topological Analyses of the Reaction between Nitrones and Lithium Enolates
Authors: Roca‐López David , Polo Victor , Tejero Tomás , Merino Pedro
Published: May 2015

The mechanism of the addition of lithium enolates derived from esters, ketones and aldehydes to nitrones (Mannich‐type reaction) has been studied using DFT methods. While the reactions with α‐methoxy and α‐methyl enolates takes place through a stepwise mechanism, consisting of an initial nucleophilic attack of the enolate to the nitrone carbon followed by a second nucleophilic attack of the nitrone oxygen to the formed carbonyl group, the reaction with α‐unsusbtituted enolates takes place through a one‐step mechanism. The IRC analysis shows the presence of a hidden intermediate in agreement with one kinetic step two stages process. The topological analysis of the electronic localization function (ELF) confirms that only when the first C–C bond is formed, does the C–O bond formation begin. The NCI analyses, are also in agreement with the formation of intermediates for α‐methoxy and α‐methyl enolates and a highly asynchronous one‐step process in the case of α‐unsusbtituted enolates.
Enabling Asymmetric Alkynylation of Azaaryl Aldehydes with Soai Autocatalyst
Authors: Funes‐Maldonado Matías , Sieng Bora , Amedjkouh Mohamed
Published: May 2015

A new sequence of autocatalysis–catalysis in asymmetric alkynylation of azaaryl aldehydes in the presence of Soai (5‐pyrimidyl)alkanol as chiral catalyst is documented. The autocatalyst can be generated from almost racemic environment to up to 99.5 % ee and subsequently propagates this chirality to provide propargylic alcohols in up to 86 % ee.
Asymmetric Amplification Coupling Enantioselective Autocatalysis and Asymmetric Induction for Alkylation of Azaaryl Aldehydes
Authors: Romagnoli Carlo , Sieng Bora , Amedjkouh Mohamed
Published: May 2015

Herein, we describe a chemical system combining asymmetric amplification of Soai's autocatalyst alongside a catalytic addition of Zn(iPr)2 to azaaryl aldehydes. Thus, Soai autocatalyst is amplified in situ from 11 to > 98 % ee and concomitantly catalyzes the alkylation of pyridine aldehydes to provide alkanols with up to 99 % ee. Also, exceptional amplifications of ee in one cycle are observed for both compounds produced throughout the reaction, probably as a result of interactions in a reaction network coupling enantioselective autocatalysis and asymmetric induction.
Synthesis of Perfluoroalkyl‐Substituted Vinylcyclopropanes by Way of Enhanced Neighboring Group Participation
Authors: Kelly Christopher B. , Mercadante Michael A. , Carnaghan Emma R. , Doherty Matthew J. , Fager Diana C. , Hauck John J. , MacInnis Allyson E. , Tilley Leon J. , Leadbeater Nicholas E.
Published: May 2015

A simple, high yielding, two‐step, one‐pot protocol for the preparation of trifluoromethyl‐substituted vinylcyclopropanes from α‐CF3 homoallyl alcohols is disclosed. Destabilization of the cationic intermediate by the electron‐withdrawing CF3 group greatly enhances neighboring group participation of the alkene, allowing ring closure to predominate. The reaction can be extended to the difluoromethyl and pentafluoroethyl group, enabling the preparation of a diverse array of fluoroalkyl‐substituted vinylcyclopropanes.
Mesenchymal Stem Cells Repress Osteoblast Differentiation Under Osteogenic‐Inducing Conditions
Authors: Santos Thiago S. , Abuna Rodrigo P.F. , Castro Raucci Larissa M.S. , Teixeira Lucas N. , de Oliveira Paulo T. , Beloti Marcio M. , Rosa Adalberto L.
Published: May 2015

This study was designed to investigate the influence of mesenchymal stem cells (MSCs) on osteoblast (OB) differentiation. Rat bone marrow MSCs were cultured either in growth medium that maintained a MSC phenotype or in osteogenic medium that induced differentiation into OBs. Then, cells were grown in two different culture conditions: indirect co‐culture of MSCs and OBs and OBs cultured in MSC‐conditioned medium. As a control culture condition, OBs were grown in osteogenic medium without the influence of MSCs. We evaluated cell proliferation, the gene expression of key bone markers, alkaline phosphatase (ALP) activity, bone sialoprotein (BSP) expression, and extracellular matrix mineralization. The results showed that, regardless of whether OBs were indirectly co‐cultured with MSCs or cultured in MSC‐conditioned medium, MSCs repressed OB differentiation, as evidenced by the downregulation of all evaluated bone marker genes, decreased ALP activity, inhibition of BSP protein expression, and reduced extracellular matrix mineralization. Taken together, these results indicate that despite the key role of both MSCs and OBs in the osteogenic process, the repressive effect of MSCs on OB differentiation in an osteogenic environment may represent a barrier to the strategy of using them together in cell‐based therapies to induce bone repair. J. Cell. Biochem. 116: 2896–2902, 2015. © 2015 Wiley Periodicals, Inc.
Synthesis of Isoxazole, 1, 2, 4‐Oxadiazole and (1H‐Pyrazol‐4‐yl)‐methanone Oxime Derivatives from N‐Hydroxy‐1H‐pyrazole‐4‐carbimidoyl Chloride and their Biological Activity
Authors: Sangepu Bhavanarushi , Gandu Bharath , Anupoju Gangagnirao , Jetti Vatsalarani
Published: May 2015

Some novel isoxazole‐, 1,2,4 oxadiazole‐, and (1H‐pyrazol‐4‐yl)‐methanone oxime derivatives were synthesized from N‐hydroxy‐1H‐pyrazole‐4‐carbimidoyl chloride and the structures of all products were identified by spectral data (1H‐NMR, 13C‐NMR, IR, MS, and HRMS) and evaluated their antibacterial activity.
Synthesis and Some Biological Properties of Pyrrolo[1,2‐a]indoles
Authors: Monakhova Natalia , Ryabova Svetlana , Makarov Vadim
Published: May 2015

The procedures for the synthesis of substituted pyrrolo[1,2‐a]indoles and some of their biological properties are reviewed.
A New Synthetic Framework for 11‐Demethylellipticine
Authors: Göçmentürk Mustafa , Gündoğdu Hızlıateş Cevher , Ergün Yavuz
Published: May 2015

A new synthetic route for the synthesis of 5‐methyl‐6H‐pyrido[4,3‐b]carbazole (8), so‐called 11‐demethylellipticine, was described. Construction of the tetracyclic structure hexahydro‐1H‐pyrido[4,3‐b]carbazol‐5(6H)‐one skeleton (6) was also achieved by nucleophilic substitution reaction in the synthetic route. Also new tetrahydrocarbazole derivatives (2, 3, 4, and 5) were synthesized. Several ellipticine analogs and octahydropyridocarbazole‐based G‐protein coupled receptors inhibitors can also be synthesized from tetracyclic structure (6) because of carbonyl functionality at position 5.
Three‐Component [3 + 3] Heterocyclizations for Flexible Synthesis of Bicyclic Fused Pyridines Under Microwave Irradiation
Authors: Liu Jie , Pan Yuan‐Yuan , Xue Li‐Yuan , Hao Wen‐Juan , Zhang Jin‐Peng , Wang Shu‐Liang , Jiang Bo
Published: May 2015

Three‐component [3 + 3] heterocyclizations have been established under microwave irradiation, providing a flexible synthetic approach toward bicyclic fused pyridines. 3,5‐Dibenzylidenedihydro‐2H‐pyran‐4(3H)‐ones were subject with malononitrile and aromatic amines in cosolvent of HOAc and N,N‐dimethylformamide, affording 10 examples of pyrano[4,3‐b]pyridine derivatives in good to excellent yields. Similarly, seven examples of thiopyrano[4,3‐b]pyridine derivatives were obtained using sulfur‐tethered heterocyclones as a reaction partner.
Two‐step Synthesis of New γ‐Lactones via Cyclization of 7‐Chloro‐2‐(methoxycarbonyl)‐4‐6‐dimethylocta‐(2E,4E,6E)‐trienoic acid
Authors: Dillenschneider Jean‐Marc , Dufossé Laurent , Fouillaud Mireille , Sutthiwong Nuthathai , Labia Roger , Valla Alain
Published: May 2015

A new rapid synthesis of γ‐lactones, cis fused with a cyclopentenic ring by thermal cyclization of 7‐chloro‐2‐(methoxycarbonyl)‐4‐6‐dimethylocta‐7‐phenyl (or methyl) (2E,4E,6E)‐trienoic acids was reported. The key step implicates an intramolecular cyclization to a cyclopentenyl cation, according to an electrocyclic π2s +  π2a conrotatory process, published in a recent paper (from the corresponding diacids). We have investigated the thermal behavior of the corresponding half‐esters since; if the cyclization obeys to the proposed mechanism, the diacids, half‐esters must also cyclize in a similar manner. Saponification of these led to γ‐dilactones via intermediary cyclopropanes. Mechanistic pathways were investigated.
Measuring Local Government Service Delivery Performance: Challenges and (PARTIAL) Solutions in Indonesia
Authors: Lewis Blane D. , McCulloch Neil , Sacks Audrey
Published: May 2015

Indonesia, like many developing countries around the world, is increasingly turning to the use of a range of intergovernmental incentives to encourage improved local government performance in the delivery of services. Central government has access to a number of plausible indicators with which to measure local performance and operationalise incentive‐based programmes. However, there are major reliability and validity concerns related to even the best among the available indicators, and these create significant challenges for their intended uses. Technical approaches can partially overcome measurement problems, but more and better data will eventually have to be collected. Furthermore, government will have to take significant care in its choice and employment of methods to assess performance in a competent and transparent manner. Copyright © 2015 John Wiley & Sons, Ltd.
Vibrational analysis of cinchona alkaloids in the solid state and aqueous solutions
Authors: Roman Maciej , Chruszcz‐Lipska Katarzyna , Baranska Malgorzata
Published: May 2015

Cinchona alkaloids are well‐known antimalarial compounds also used in asymmetric synthesis in organic chemistry. In this work, vibrational spectra of quinine, quinidine, cinchonine, and cinchonidine were acquired and interpreted on the basis of theoretical calculations. Normal Raman spectra of the alkaloids in solution exhibit similar patterns and cannot be used for differentiation between the derivatives (e.g. quinine and cinchonidine) and corresponding pseudoenantiomers (e.g. quinine and quinidine). Thus, Raman Optical Activity (ROA) method was applied to show distinct differences related to the configuration of chiral atoms. ROA allowed unequivocal identification of the pseudoenantiomers based on the sign of the characteristic bands from a single measurement. The experiments were supported by the theoretical approach including conformational study followed by wavenumber calculations and Potential Energy Distribution (PED) analysis. For quinine, vibrational spectroscopy was additionally used to show its structural changes in aqueous solutions at various pH and its distribution in a pharmaceutical product. Spatial distribution of quinine in a drug was observed by the FT‐Raman mapping technique. Copyright © 2015 John Wiley & Sons, Ltd.
Characterization of crosstalk in stereoscopic display devices
Authors: Zafar Fahad , Badano Aldo
Published: May 2015

Many different types of stereoscopic display devices are used for commercial and research applications. Stereoscopic displays offer the potential to improve performance in detection tasks for medical imaging diagnostic systems. Due to the variety of stereoscopic display technologies, it remains unclear how these compare with each other for detection and estimation tasks. Different stereo devices have different performance trade‐offs due to their display characteristics. Among them, crosstalk is known to affect observer perception of 3D content and might affect detection performance. We measured and report the detailed luminance output and crosstalk characteristics for three different types of stereoscopic display devices. We recorded the effect of other issues on recorded luminance profiles such as viewing angle, use of different eye wear, and screen location. Our results show that the crosstalk signature for viewing 3D content can vary considerably when using different types of 3D glasses for active stereo displays. We also show that significant differences are present in crosstalk signatures when varying the viewing angle from 0 degrees to 20 degrees for a stereo mirror 3D display device. Our detailed characterization can help emulate the effect of crosstalk in conducting computational observer image quality assessment evaluations that minimize costly and time‐consuming human reader studies.
Relationships between Social and Intellectual Capital: Empirical Evidence from IC Statements
Authors: Demartini Chiara
Published: May 2015

This paper investigates on the determinants of a firm's intellectual capital (IC). Acknowledging the literature on this topic, we focused on the effect that the assessment of social capital (SC) has on intellectual capital, according to the theoretical model put forward by previous studies. Starting from the concept of organisational advantage, they argued that three SC dimensions, namely, the structural, the cognitive and the relational dimensions, contribute to the creation of IC. Different facets of the three dimensions help in providing combination capabilities and motivating the exchange of IC that eventually produce new IC. This study extends this literature by empirically investigating on these relationships. By analysing the contents of the IC statements disclosed by 36 firms, we first identified which indicator, or measure, has been developed and assessed to monitor the facets of SC and the level of IC. Then, we performed a path analysis, using partial least square models, in order to uncover the effect that the single SC dimension has on the creation of IC. Sometimes results contradict the theoretical assumptions. Theory, in fact, predicts that cognitive and structural dimensions of SC enhance human capital, but empirical evidence did not support this hypothesis. Similar argumentations can be put forward for the empirical evidence from the path between the cognitive dimension of SC and organisational IC. On the other hand, as theoretically predicted, an increase in the assessment of the level of relational SC has a positive effect on the level of human capital. Copyright © 2015 John Wiley & Sons, Ltd.
Can the Reaction Mechanism of Radical Solution Polymerization Explain the Microgel Final Particle Volume in Precipitation Polymerization ofN‐Isopropylacrylamide?
Authors: Virtanen Otto L. J. , Ala‐Mutka Helmi M. , Richtering Walter
Published: May 2015

Precise particle size customization is a key requirement for the applications of stimuli‐sensitive poly(N‐isopropylacrylamide) microgels. No empirically supported mechanism has been presented to explain the microgel particle size dependence on polymerization conditions. In this work, nonstirred precipitation polymerization is employed to address this question. It is argued that the reaction proceeds by radical solution polymerization mechanism rather than as emulsion polymerization. The number of particles in the batch, and the microgel particle volume, is shown to correlate with the charge density of the particles determined by the kinetic chain length. Cross‐linking efficiency is recognized to be an important factor in the particle nucleation. Properties of radical solution polymerization, such as differences in the rate of decomposition of thermally decomposing initiator and redox initiator, are used to tune the particle number density in the batch. Contemporary synthesis approaches, including temperature‐programmed synthesis, are discussed in the context of these results.

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Peptide Binding Prediction to Five Most Frequent HLA‐DQ Proteins – a Proteochemometric Approach
Authors: Dimitrov Ivan , Doytchinova Irini
Published: May 2015

Major histocompatibility complex (MHC) proteins class II, are glycoproteins binding within the cell to short peptides with foreign origin, called epitopes, and present them at the cell surface for inspection by T‐cells. Apart from presenting foreign antigens, they are able to present also common self‐antigens and trigger autoimmune diseases as coeliac disease and diabetes mellitus type 1. The MHC proteins are extremely polymorphic. The polymorphism is located mainly in the peptide binding site. In the present study, we apply a proteochemometric approach to derive a model for prediction of peptide binding to human MHC class II proteins from locus HLA‐DQ. Proteochemometrics was applied on 2624 peptides binding to five most frequent HLA‐DQ proteins. The sequences of peptides and proteins were described by three z‐descriptors relating to hydrophobicity, steric effects and polarity of amino acids. Cross‐terms accounting for the protein‐peptide interactions also were included. The derived model was validated by external test set of 660 peptides and showed rpred2=0.808, AUC=0.965, 92.5 % accuracy at threshold of pIC50=5.3 and average sensitivity of 83 % among the top 10 % best predicted nonamers. The model is implemented in the server for MHC binding prediction EpiTOP and is freely available at http://www.ddg‐pharmfac.net/epitop.
Gastrointestinal absorption and metabolism of hesperetin‐7‐O‐rutinoside and hesperetin‐7‐O‐glucoside in healthy humans
Authors: Actis‐Goretta Lucas , Dew Tristan P. , Lévèques Antoine , Pereira‐Caro Gema , Rein Maarit , Teml Alexander , Schäfer Christian , Hofmann Ute , Schwab Matthias , Eichelbaum Michel , Crozier Alan , Williamson Gary
Published: May 2015

Scope

Hesperetin‐7‐O‐rutinoside (hesperidin) reduces blood pressure in healthy volunteers but its intestinal absorption and metabolism are not fully understood. Therefore, we aimed to determine sites of absorption and metabolism of dietary flavanone glycosides in humans.

Methods and results

Using a single‐blind, randomized crossover design, we perfused equimolar amounts of hesperetin‐7‐O‐rutinoside and hesperetin‐7‐O‐glucoside directly into the proximal jejunum of healthy volunteers. We assessed the appearance of metabolites in the perfusate, blood and urine, to determine the sites of metabolism and excretion, and compared this to oral administration. The glucoside was rapidly hydrolyzed by brush border enzymes without any contribution from pancreatic, stomach, or other secreted enzymes, or from bacterial enzymes. Only ∼3% of the dose was recovered intact in the perfusate, indicating high absorption. A proportion was effluxed directly back into the perfused segment mainly in the form of hesperetin‐3′‐O‐sulfate. In contrast, very little hydrolysis or absorption of hesperetin‐7‐O‐rutinoside was observed with ∼80% recovered in the perfusate, no hesperetin metabolites were detected in blood and only traces were excreted in urine.

Conclusion

The data elucidate the pathways of metabolism of dietary hesperidin in vivo and will facilitate better design of mechanistic studies both in vivo and in vitro.
Coexistence of a T118M PMP22 missense mutation and chromosome 17 (17p11.2‐p12) deletion
Authors: Jerath Nivedita U. , Kamholz John , Grider Tiffany , Harper Amy , Swenson Andrea , Shy Michael E.
Published: May 2015

Introduction: We describe a 6‐year‐old girl with a T118M PMP22 mutation and heterozygous deletion of PMP22 on chromosome 17 (17p11.2‐p12) resulting in a severe sensorimotor polyneuropathy. Methods: This study is a case report in which the relevant mutations are described. Results: Foot pain, cavovarus feet, tibialis anterior atrophy, absent reflexes, and inability to walk were found when the patient was age 6 years. Nerve conduction studies showed evidence of a sensorimotor polyneuropathy and compressive mononeuropathies of bilateral median nerves at the wrist and ulnar nerves at the elbow. Genetic testing revealed deletion of a PMP22 allele and T118M PMP22 mutation in the remaining allele. Conclusions: The severe sensorimotor polyneuropathy and hereditary neuropathy with liability to pressure palsies (HNPP) in this patient was likely a consequence of both decreased expression of PMP22 causing features consistent with HNPP and unopposed expression of the T118M mutant form of PMP22 that is relatively benign in the heterozygous state. The T118M mutant form of PMP22 can be disease‐modifying in the appropriate circumstances. Muscle Nerve 52: 905–908, 2015
Fracture load and force load at upper yield of alkaline‐resistant glass fiber‐reinforced endodontic posts
Authors: Baldea Bogdan , Silaghi‐Dumitrescu Laura , Furtos Gabriel
Published: May 2015

Three experimental glass fiber posts (EGFP) based on 2,2‐bis[4‐(2‐hydroxy‐3‐methacryloyloxypropoxy)‐phenyl] propane, triethyleneglycol dimethacrylate monomers, and alkaline‐resistant (AR) glass fibers were obtained. The EGFP as well as 29 commercial endodontic posts were investigated for fracture load, force load at upper yield, and filler content. Each post was loaded at a 135° angle to the root's long axis using a universal testing machine, and the maximum strength was recorded. EGFP showed the fracture load values from 68.02 to 115.97 N, and the force load at upper yield values from 38.70 to 70.46 N. The filler content of the EGFP ranged between 49.64 and 62.67 vol%. EGFP showed mechanical strength comparable to other posts already on the market. A polymer matrix based on bis‐GMA/TEGDMA and AR glass fibers could be an alternative to epoxy resin and glass fibers from commercial endodontic posts. POLYM. COMPOS., 38:260–267, 2017. © 2015 Society of Plastics Engineers
Clustering Empirical Failure Rate Curves for Reliability Prediction Purposes in the Case of Consumer Electronic Products
Authors: Dombi József , Jónás Tamás , Tóth Zsuzsanna Eszter
Published: May 2015

In this paper, a methodology based on the combination of time series modeling and soft computational methods is presented to model and forecast bathtub‐shaped failure rate data of newly marketed consumer electronics. The time‐dependent functions of historical failure rates are typified by parameters of an analytic model that grabs the most important characteristics of these curves. The proposed approach is also verified by the presentation of an industrial application brought along at an electrical repair service provider company. The prediction capability of the introduced methodology is compared with moving average‐based and exponential smoothing‐based forecasting methods. According to the results of comparison, the presented method can be considered as a viable alternative reliability prediction technique. Copyright © 2015 John Wiley & Sons, Ltd.