bluuebunny/crossref_metadata_2025 huggingface dataset:
Divergent Coordination Chemistry: Parallel Synthesis of [2×2] Iron(II) Grid‐Complex Tauto‐Conformers
Authors: Schäfer Bernhard , Greisch Jean‐François , Faus Isabelle , Bodenstein Tilmann , Šalitroš Ivan , Fuhr Olaf , Fink Karin , Schünemann Volker , Kappes Manfred M. , Ruben Mario
Published: July 2016

The coordination of iron(II) ions by a homoditopic ligand L with two tridentate chelates leads to the tautomerism‐driven emergence of complexity, with isomeric tetramers and trimers as the coordination products. The structures of the two dominant [FeII4L4]8+ complexes were determined by X‐ray diffraction, and the distinctness of the products was confirmed by ion‐mobility mass spectrometry. Moreover, these two isomers display contrasting magnetic properties (FeII spin crossover vs. a blocked FeII high‐spin state). These results demonstrate how the coordination of a metal ion to a ligand that can undergo tautomerization can increase, at a higher hierarchical level, complexity, here expressed by the formation of isomeric molecular assemblies with distinct physical properties. Such results are of importance for improving our understanding of the emergence of complexity in chemistry and biology.
A Dinitrogen Dicopper(I) Complex via a Mixed‐Valence Dicopper Hydride
Authors: Zhang Shiyu , Fallah Hengameh , Gardner Evan J. , Kundu Subrata , Bertke Jeffery A. , Cundari Thomas R. , Warren Timothy H.
Published: July 2016

Low‐temperature reaction of the tris(pyrazolyl)borate copper(II) hydroxide [iPr2TpCu]2(μ‐OH)2 with triphenylsilane under a dinitrogen atmosphere gives the bridging dinitrogen complex [iPr2TpCu]2(μ‐1,2‐N2) (3). X‐ray crystallography reveals an only slightly activated N2 ligand (N‐N: 1.111(6) Å) that bridges between two monovalent iPr2TpCu fragments. While DFT studies of mono‐ and dinuclear copper dinitrogen complexes suggest weak π‐backbonding between the d10 CuI centers and the N2 ligand, they reveal a degree of cooperativity in the dinuclear Cu‐N2‐Cu interaction. Addition of MeCN, CNAr2,6‐Me, or O2 to 3 releases N2 with formation of iPr2TpCu(L) (L=NCMe, CNAr2,6‐Me2) or [iPr2TpCu]2(μ‐η2:η2‐O2) (1). Addition of triphenylsilane to [iPr2TpCu]2(μ‐OH)2 in pentane allows isolation of a key intermediate [iPr2TpCu]2(μ‐H) (5). Although 5 thermally decays under N2 to give 3, it reduces unsaturated substrates, such as CO and HC≡CPh to HC(O)H and H2C=CHPh, respectively.
Structural Interpretation of Metastable States in Myoglobin–NO
Authors: Soloviov Maksym , Das Akshaya K. , Meuwly Markus
Published: July 2016

Nitric oxide binding and unbinding from myoglobin (Mb) is central to the function of the protein. By using reactive molecular dynamics (MD) simulations, the dynamics following NO dissociation were characterized in both time and space. Ligand rebinding can be described by two processes on the 10 ps and 100 ps timescale, which agrees with recent optical and X‐ray absorption experiments. Explicitly including the iron out‐of‐plane (Fe‐oop) coordinate is essential for a meaningful interpretation of the data. The proposed existence of an “Fe‐oop/NO‐bound” state is confirmed and assigned to NO at a distance of approximately 3 Å away from the iron atom. However, calculated XANES spectra suggest that it is diffcult to distinguish between NO close to the heme‐Fe and positions further away in the primary site. Another elusive state, with Fe−ON coordination, was not observed experimentally because it is masked by the energetically more favorable but dissociative 4A state in this region, which makes the Fe−ON local minimum unobservable in wild‐type Mb. However, suitable active‐site mutations may stabilize this state.
Designer Extracellular Matrix Based on DNA–Peptide Networks Generated by Polymerase Chain Reaction
Authors: Finke Alexander , Bußkamp Holger , Manea Marilena , Marx Andreas
Published: July 2016

Cell proliferation and differentiation in multicellular organisms are partially regulated by signaling from the extracellular matrix. The ability to mimic an extracellular matrix would allow particular cell types to be specifically recognized, which is central to tissue engineering. We present a new functional DNA‐based material with cell‐adhesion properties. It is generated by using covalently branched DNA as primers in PCR. These primers were functionalized by click chemistry with the cyclic peptide c(RGDfK), a peptide that is known to predominantly bind to αvβ3 integrins, which are found on endothelial cells and fibroblasts, for example. As a covalent coating of surfaces, this DNA‐based material shows cell‐repellent properties in its unfunctionalized state and gains adhesiveness towards specific target cells when functionalized with c(RGDfK). These cells remain viable and can be released under mild conditions by DNase I treatment.
Schiff base complex of palladium immobilized on magnetic nanoparticles: an efficient and recyclable nanocatalyst for CC coupling reactions
Authors: Rezaei Somaieh , Ghorbani‐Choghamarani Arash , Badri Rashid
Published: July 2016

A Schiff base complex of palladium anchored on Fe3O4 magnetic nanoparticles as an efficient and magnetically reusable nanocatalyst is reported for CC bond formation through Heck and Suzuki reactions. The catalyst was easily recovered and reused several times without significant loss of its catalytic efficiency or palladium leaching. The magnetic nanocatalyst was characterized using Fourier transform infrared and inductively coupled plasma atomic emission spectroscopies, thermogravimetric analysis, vibrating sample magnetometry, and transmission and scanning electron microscopies. Copyright © 2016 John Wiley & Sons, Ltd.
A novel flame retardant UV‐curable vinyl ester resin monomer based on industrial dipentene: Preparation, characterization, and properties
Authors: Mao Wei , Li Shouhai , Li Mei , Yang Xuejuan , Song Jian , Wang Mei , Xia Jianling , Huang Kun
Published: July 2016

A novel bio‐based and flame‐retardant UV‐curable vinyl ester resin (VER) monomer named Diglycidyl ester of maleinized dipentene modified with dibutyphosphate and methacrylic anhydride (MDDMD) was synthesized from industrial dipentene via Diels‐Alder reaction, glycidylation, epoxy ring‐opening reaction, and esterification. Its chemical structures were characterized by Fourier transform infrared (FTIR) analysis and proton nuclear magnetic resonance (1H‐NMR). In order to improve its flexibility, we prepared a series of copolymers under UV light radiation by mixing it with certain proportions of poly(ethylene glycol) dimethacrylate‐200 (PEGDMA‐200) which contained flexible groups. Their tensile property, curing degrees (CD), hardness, limiting oxygen index (LOI), dynamic mechanical thermal properties, and thermostability were all investigated. The cured mixed resins have a relatively high tensile strength of 10.05 MPa and curing degrees up to 92.5%. Both hardness (range: 50 to 23 HD) and LOI (range: 22.8% to 24.4%) of cured resins are improved with the increase of MDDMD content. Dynamic mechanical analysis (DMA) shows that their glass transition temperatures rise with the increase of MDDMD content. Thermogravimetric analysis (TGA) shows that the thermal stability of cured resins is enhanced with the increase of PEGDMA‐200 content, as the main thermal initial decomposition temperatures are all above 260 °C and char yield at 800 °C are above 18.10%. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44084.
Electrical behavior of dual‐morphology polyaniline
Authors: Kumar Anil , Jangir Lokesh Kumar , Kumari Yogita , Kumar Manoj , Kumar Vinod , Awasthi Kamlendra
Published: July 2016

An attempt was taken to synthesize two types of polyaniline (PANI) with and without solvent followed by drying in air and vacuum oven conditions resulting different morphologies. The PANIs were prepared by chemical oxidative polymerization and studied with respect to their morphological features. Scanning electron microscopy, thermogravimetric analysis, X‐ray diffractometry, Fourier transform infrared spectroscopy, and ultraviolet–visible spectroscopy techniques were used for the characterization studies. The PANI synthesized with a solvent had a mixed morphology (fibrillar and granular), whereas PANI synthesized without a solvent had only a granular morphology. The direct‐current electrical conductivities of the samples were evaluated with an electrometer. We observed that the PANIs with mixed morphology (with solvent) were more electrically conducting than those with a single morphology (without solvent). On drying in vacuo, the conductivity of PANI decreased from 3.3 × 10−2 to 0.3 × 10−2 S/cm with solvent treatment, whereas it decreased from 0.1 × 10−2 to 0.3 × 10−3 S/cm without solvent treatment. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44091.
Morphological and nanomechanical characterization of anisotropic interfacial characteristic regions in CF/PA6 composites at different cooling rates
Authors: Li H. , Zhang Y. , Bai G. , Zhang B.
Published: July 2016

Macroscopic tensile tests on neat PA6 and CF/PA6 prepregs showed that the cooling rate significantly affects the mechanical properties of CF/PA6 composites because of their different crystallization behaviors both at the fiber surface and in the matrix. Polarizing optical microscopy, static nanoindentation (SNI), and dynamic mechanical imaging (DMI) tests were used to characterize the anisotropic morphologies and nanomechanical performances of the interfacial characteristic regions in CF/PA6 composites at five different cooling rates. As a result, the seven interfacial characteristic regions inside the CF/PA6 composites were clearly distinguished. The interphase thickness of the CF/PA6 composites decreased with a decrease in the cooling rate. On the contrary, the interphase modulus and transcrystallinity thickness and modulus showed significant increases with a decrease in the cooling rate. The DMI and SNI test results were in agreement with each other and with the macromechanical test results. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44106.
The effect of ceria nanoparticles on improving heat resistant properties of fluorosilicone rubber
Authors: Xu Xiang , Liu Junjie , Chen Pei , Wei Dafu , Guan Yong , Lu Xiaojuan , Xiao Huining
Published: July 2016

The thermal aging behavior of poly(3,3,3‐trifluoropropyl)methylsiloxane was investigated by thermal gravimetric analysis and isothermal aging tests, and the results indicated the degradation mechanism II, oxidation scission of the side groups, played a more important role when the temperature was below 350 °C. The addition of ceria had significantly improved the thermal stability of fluorosilicone rubber (FSR) by inhibiting the oxidation scission. Moreover, two types of ceria including laminar‐structure ceria (LS‐CeO2) and nanoparticle ceria (N‐CeO2) were prepared and surface was modified by KH570 and characterized by scanning electron microscopy, transmission electron microscope, and X‐ray diffractometer. FSR incorporated with modified LS‐CeO2 and N‐CeO2 revealed a significant improvement on the heat resistant properties. In particular, after having been thermal oxidative aged for 70 h at 250 °C, FSR containing 2 wt % of modified N‐CeO2 maintained 72.6% of tensile strength and 63.9% of elongation at break, respectively, while FSR without ceria completely failed. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44117.
Development of tunable biodegradable polyhydroxyalkanoates microspheres for controlled delivery of tetracycline for treating periodontal disease
Authors: Panith Nootchanartch , Assavanig Apinya , Lertsiri Sittiwat , Bergkvist Magnus , Surarit Rudee , Niamsiri Nuttawee
Published: July 2016

This article was aimed at preparation and characterization of drug delivery carriers made from biodegradable polyhydroxyalkanoates (PHAs) for slow release of tetracycline (TC) for periodontal treatment. Four PHA variants; polyhydroxybutyrate (PHB), poly(hydroxybutyrate‐co‐hydroxyvalerate) with 5, 12, and 50% hydroxyvalerate were used to formulate TC‐loaded PHA microspheres by double emulsion‐solvent evaporation method. We also compared the effect of different molecular weight (Mw) of polyvinyl alcohol (PVA) acting as surface stabilizer on particle size, drug loading, encapsulation efficiency, and drug release profile. The TC‐loaded PHA microspheres exhibited microscale and nanoscale spherical morphology under scanning electron microscopy. Among formulations, TC‐loaded PHB:low Mw PVA demonstrated the highest TC loading with slow release behavior. Our results showed that the release rate from PHA microspheres was influenced by both the type of PHA and Mw of PVA stabilizer. Lastly, TC‐loaded PHB microspheres showed efficient killing activity against periodontitis‐causing bacteria, suggesting its potential application for treating periodontal disease. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44128.
Finding time‐robust fuel‐efficient paths for a call‐taxi in a stochastic city road network
Authors: Godwin T. , Sajeev Karthik , George Albert C.
Published: July 2016

Intra‐city commuting is being revolutionized by call‐taxi services in many developing countries such as India. A customer requests a taxi via phone, and it arrives at the right time and at the right location for the pick‐up. This mode of intra‐city travel has become one of the most reliable and convenient modes of transportation for customers traveling for business and non‐business purposes. The increased number of vehicles on city roads and raising fuel costs has prompted a new type of transportation logistics problem of finding a fuel‐efficient and quickest path for a call‐taxi through a city road network, where the travel times are stochastic. The stochastic travel time of the road network is induced by obstacles such as the traffic signals and intersections. The delay and additional fuel consumption at each of these obstacles are calculated that are later imputed to the total travel time and fuel consumption of a path. A Monte‐Carlo simulation‐based approach is proposed to identify unique fuel‐efficient paths between two locations in a city road network where each obstacle has a delay distribution. A multi‐criteria score is then assigned to each unique path based on the probability that the path is fuel efficient, the average travel time of the path and the coefficient of variation of the travel times of the path. Copyright © 2016 John Wiley & Sons, Ltd.
Interaction of glucose‐derived carbon quantum dots with silver and gold nanoparticles and its application for the fluorescence detection of 6‐thioguanine
Authors: Amjadi Mohammad , Shokri Roghayeh , Hallaj Tooba
Published: July 2016

The interaction of glucose‐derived carbon quantum dots (CQDs) with silver (Ag) and gold (Au) nanoparticles (NPs) was explored by fluorescence spectroscopy. Both metal NPs cause an efficient quenching of CQD fluorescence, which is likely due to the energy transfer process between CQDs as donors and metal NPs as acceptors. The Stern–Volmer plots were evaluated and corresponding quenching constants were found to be 1.9 × 1010 and 2.2 × 108 M−1 for AgNPs and AuNPs, respectively. The analytical applicability of these systems was demonstrated for turn‐on fluorescence detection of the anti‐cancer drug, 6‐thioguanine. Because the CQD–AgNP system had much higher sensitivity than the CQD–AuNP system, we used it as a selective fluorescence probe in a turn‐on assay of 6‐thioguanine. Under optimum conditions, the calibration graph was linear from 0.03 to 1.0 μM with a detection limit of 0.01 μM. The developed method was applied to the analysis of human plasma samples with satisfactory results.
A New Route to Phenols: Palladium‐Catalyzed Cyclization and Oxidation of γ,δ‐Unsaturated Ketones
Authors: Samadi Sadaf , Orellana Arturo
Published: July 2016

We report a new strategy for the synthesis of phenols from acyclic unsaturated ketones in one pot. The reaction proceeds by palladium‐catalyzed carbopalladation of an alkene with the enol form of the tethered ketone, generating a substituted cyclohexanone. Upon introduction of a terminal oxidant a palladium‐catalyzed oxidation ensues to give the desired phenol. This approach allows the programming of phenol substituents on the acyclic substrate and therefore circumvents the limitations inherent in traditional syntheses of phenols.
Selective and High‐Yield Synthesis of Oblate Superatom [PdAu8(PPh3)8]2+
Authors: Matsuo Shota , Takano Shinjiro , Yamazoe Seiji , Koyasu Kiichirou , Tsukuda Tatsuya
Published: July 2016

The front cover artwork is provided by the group of Tatsuya Tsukuda at the University of Tokyo (Japan). The image shows that the PdAu8 core of [PdAu8(PPh3)8]2+ can be viewed as an oblate supertatom with an electronic configuration of (1S)2(1P)4. Read the full text of the Article at 10.1002/celc.201600115.
Three‐Dimensional Molybdenum Disulfide Nanoflowers Decorated on Graphene Nanosheets for High‐Performance Lithium‐Ion Batteries
Authors: Xu Laiqiang , Jiao Zheng , Hu Pengfei , Wang Yong , Wang Yijia , Zhang Haijiao
Published: July 2016

A simple hydrothermal route was designed to prepare 3D flower‐like MoS2/graphene composites (FL‐MoS2/graphene). Herein, two products, denoted C‐FL‐MoS2/graphene and N‐FL‐MoS2/graphene, were produced by facile glucose‐ and glucosamine‐mediated methods, respectively. Both composites were found to show a well‐defined morphology with a unique structure, in which the dispersed MoS2 nanoflowers are tightly anchored onto the graphene nanosheets. Moreover, the nanoflowers are constructed by a lot of wrinkled MoS2 thin nanosheets, which generates numerous open voids. In the process, glucose or glucosamine as the binder plays a similar role in regulating the growth of flower‐like MoS2 on graphene. In terms of electrochemical performance, the FL‐MoS2/graphene composite demonstrates superior lithium‐storage capabilities, including a high reversible capacity, excellent cycle stability, and good rate capability, than N‐MoS2/graphene (without the addition of any binder). Specifically, C‐FL‐MoS2/graphene shows a high reversible capacity of 980 mA h g−1 at a current of 100 mA g−1 even after 100 cycles, and a significantly improved high rate capability of 740 mA h g−1 is also retained at a current density of 1000 mA g−1. The remarkable performance of FL‐MoS2/graphene was determined to result mainly from the unique architecture comprising 3D flower‐like MoS2 particles and graphene nanosheets with superior conductivity.
Eliminated Phototoxicity of TiO2 Particles by an Atomic‐Layer‐Deposited Al2O3 Coating Layer for UV‐Protection Applications
Authors: Jang Eunyong , Sridharan Kishore , Park Young Min , Park Tae Joo
Published: July 2016

We demonstrate the conformal coating of an ultrathin Al2O3 layer on TiO2 nanoparticles through atomic layer deposition by using a specifically designed rotary reactor to eliminate the phototoxicity of the particles for cosmetic use. The ALD reactor is modified to improve the coating efficiency as well as the agitation of the particles for conformal coating. Elemental and microstructural analyses show that ultrathin Al2O3 layers are conformally deposited on the TiO2 nanoparticles with a controlled thickness. Rhodamine B dye molecules on Al2O3‐coated TiO2 exhibited a long life time under UV irradiation, that is, more than 2 h, compared to that on bare TiO2, that is, 8 min, indicating mitigation of photocatalytic activity by the coated layer. The effect of carbon impurities in the film resulting from various deposition temperatures and thicknesses of the Al2O3 layer on the photocatalytic activity are also thoroughly investigated with controlled experimental condition by using dye molecules on the surface. Our results reveal that an increased carbon impurity resulting from a low processing temperature provides a charge conduction path and generates reactive oxygen species causing the degradation of dye molecule. A thin coated layer, that is, less than 3 nm, also induced the tunneling of electrons and holes to the surface, hence oxidizing dye molecules. Furthermore, the introduction of an Al2O3 layer on TiO2 improves the light trapping thus, enhances the UV absorption.
Computational Chemistry to the Rescue: Modern Toolboxes for the Assignment of Complex Molecules by GIAO NMR Calculations
Authors: Grimblat Nicolas , Sarotti Ariel M.
Published: July 2016

The calculations of NMR properties of molecules using quantum chemical methods have deeply impacted several branches of organic chemistry. They are particularly important in structural or stereochemical assignments of organic compounds, with implications in total synthesis, stereoselective reactions, and natural products chemistry. In studying the evolution of the strategies developed to support (or reject) a structural proposal, it becomes clear that the most effective and accurate ones involve sophisticated procedures to correlate experimental and computational data. Owing to their relatively high mathematical complexity, such calculations (CP3, DP4, ANN‐PRA) are often carried out using additional computational resources provided by the authors (such as applets or Excel files). This Minireview will cover the state‐of‐the‐art of these toolboxes in the assignment of organic molecules, including mathematical definitions, updates, and discussion of relevant examples.
Highly Thermostable, Non‐oxidizable Indium, Gallium, and Aluminium Perfluorophthalocyanines with n‐Type Character
Authors: Łapok Łukasz , Obłoza Magdalena , Nowakowska Maria
Published: July 2016

Perfluorophthalocyanines incorporating three‐valent metals, namely In(Cl), Ga(Cl), and Al(Cl), have been synthesized and characterized. Thermogravimetric analysis revealed that these compounds exhibit outstanding thermal stability and a tendency to sublime at a temperature exceeding around 350 °C without thermal decomposition. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to probe the frontier orbital energy levels of these compounds in THF solution. All three compounds undergo three quasi‐reversible reductions with the first one leading to the formation of an anion radical, namely MPc−., as confirmed by spectroelectrochemistry. The compounds studied were intrinsically resistive to oxidation, which indicates that they are very good electron acceptors (n‐type materials). The HOMO–LUMO energy gaps (Eg) of the three compounds determined by UV/Vis spectroscopy were relatively unaffected by the three‐valent metals incorporated into the phthalocyanine macrocycle. Similarly, the energies of the HOMO (EHOMO) and LUMO (ELUMO) orbitals remained virtually unaffected by the three‐valent metals in the perfluorophthalocyanine. Importantly, all the perfluorophthalocyanines studied possess LUMO levels between −4.76 and −4.85 eV, which makes their reduced forms resistant to electron trapping by O2 and H2O. This property opens up the possibility for the fabrication of electronic devices operating under ambient conditions. All three compounds demonstrated very good photostability as solid thin films.
A Kinetic/Thermodynamic Origin of Regular Chiral Fluctuation or Symmetry Breaking Unique to Preferential Enrichment
Authors: Uchida Yoshiaki , Iwama Sekai , Coquerel Gérard , Tamura Rui
Published: July 2016

The kinetic/thermodynamic origin of preferential enrichment (PE), which is a spontaneous enantiomeric resolution phenomenon applicable to racemic crystals, is described. The mechanism of PE, which was unveiled with respect to the first‐generation of chiral organic compounds showing PE, has been interpreted in terms of a nonlinear complexity phenomenon including two unique processes: a solvent‐assisted solid‐to‐solid polymorphic transition and subsequent selective redissolution of the excess one enantiomer from the transformed disordered crystals into the mother liquor. The present works confirm that PE takes place because of the unique nonlinear solubility properties of the two enantiomers after the occurrence of a polymorphic transition under PE crystallization conditions at high supersaturation. Furthermore, a ternary phase diagram that is consistent with the mechanism of PE is proposed.
A Core–Shell Fe/Fe2O3 Nanowire as a High‐Performance Anode Material for Lithium‐Ion Batteries
Authors: Na Zhaolin , Huang Gang , Liang Fei , Yin Dongming , Wang Limin
Published: July 2016

The preparation of novel one‐dimensional core–shell Fe/Fe2O3 nanowires as anodes for high‐performance lithium‐ion batteries (LIBs) is reported. The nanowires are prepared in a facile synthetic process in aqueous solution under ambient conditions with subsequent annealing treatment that could tune the capacity for lithium storage. When this hybrid is used as an anode material for LIBs, the outer Fe2O3 shell can act as an electrochemically active material to store and release lithium ions, whereas the highly conductive and inactive Fe core functions as nothing more than an efficient electrical conducting pathway and a remarkable buffer to tolerate volume changes of the electrode materials during the insertion and extraction of lithium ions. The core–shell Fe/Fe2O3 nanowire maintains an excellent reversible capacity of over 767 mA h g−1 at 500 mA g−1 after 200 cycles with a high average Coulombic efficiency of 98.6 %. Even at 2000 mA g−1, a stable capacity as high as 538 mA h g−1 could be obtained. The unique composition and nanostructure of this electrode material contribute to this enhanced electrochemical performance. Due to the ease of large‐scale fabrication and superior electrochemical performance, these hybrid nanowires are promising anode materials for the next generation of high‐performance LIBs.
Enhancement of the Catalytic Activity of Chiral H8‐BINOL Titanium Complexes by Introduction of Sterically Demanding Groups at the 3‐Position
Authors: Hayashi Yasuki , Yamamura Nobuaki , Kusukawa Takahiro , Harada Toshiro
Published: July 2016

The activity of chiral titanium catalysts derived from H8‐BINOL ligands in the enantioselective arylation of an aldehyde with PhTi(OiPr)3 is significantly enhanced by an increase of the size of the substituent at the 3‐position. High enantioselectivity (> 90 % ee) can be obtained even at a substrate/catalyst ratio (S/C) of 800 for DTBP‐H8‐BINOL (DTBP=3,5‐di‐tert‐butylphenyl) and DAP‐H8‐BINOL (DAP=3,5‐di(9‐anthraceny)phenyl). These titanium catalysts are successfully applied to the enantioselective arylation and heteroarylation of aldehydes at a S/C ratio of 400 by using organotitanium reagents generated in situ from bromide precursors. The remarkable weakening of the intramolecular aggregation of the two −Ti(OiPr)3 units in a DPP‐H8‐BINOL (DPP=3,5‐diphenylpheny)‐derived bis‐titanium complex is revealed by X‐ray and variable‐temperature (VT)‐NMR studies. Based on these observations, a catalytic cycle, involving the rate‐limiting aryl group transfer followed by aldehyde complexation and enantioselective arylation, is proposed to account for the high activity of the 3‐substituted H8‐BINOL catalyst system.
Synthesis and in vivo Evaluation of Fluorine‐18 and Iodine‐123 Pyrazolo[4,3‐e]‐1,2,4‐triazolo[1,5‐c]pyrimidine Derivatives as PET and SPECT Radiotracers for Mapping A2A Receptors
Authors: Vala Christine , Morley Thomas J. , Zhang Xuechun , Papin Caroline , Tavares Adriana Alexandre S. , Lee H. Sharon , Constantinescu Cristian , Barret Olivier , Carroll Vincent M. , Baldwin Ronald M. , Tamagnan Gilles D. , Alagille David
Published: July 2016

Imaging agents that target adenosine type 2A (A2A) receptors play an important role in evaluating new pharmaceuticals targeting these receptors, such as those currently being developed for the treatment of movement disorders like Parkinson′s disease. They are also useful for monitoring progression and treatment efficacy by providing a noninvasive tool to map changes in A2A receptor density and function in neurodegenerative diseases. We previously described the successful evaluation of two A2A‐specific radiotracers in both nonhuman primates and in subsequent human clinical trials: [123I]MNI‐420 and [18F]MNI‐444. Herein we describe the development of both of these radiotracers by selection from a series of A2A ligands, based on the pyrazolo[4,3‐e]‐1,2,4‐triazolo[1,5‐c]pyrimidine core of preladenant. Each of this series of 16 ligands was found to bind to recombinant human A2A receptor in the low nanomolar range, and of these 16, six were radiolabeled with either fluorine‐18 or iodine‐123 and evaluated in nonhuman primates. These initial in vivo results resulted in the identification of 7‐(2‐(4‐(4‐(2‐[18F]fluoroethoxy)phenyl)piperazin‐1‐yl)ethyl)‐2‐(furan‐2‐yl)‐7H‐pyrazolo[4,3‐e][1,2,4]triazolo[1,5‐c]pyrimidin‐5‐amine ([18F]MNI‐444) and 7‐(2‐(4‐(2‐fluoro‐4‐[123I]iodophenyl)piperazin‐1‐yl)ethyl)‐2‐(furan‐2‐yl)‐7H‐imidazo[1,2‐c]pyrazolo[4,3‐e]pyrimidin‐5‐amine ([123I]MNI‐420) as PET and SPECT radiopharmaceuticals for mapping A2A receptors in brain.
Amacrine cells coupled to ganglion cells via gap junctions are highly vulnerable in glaucomatous mouse retinas
Authors: Akopian Abram , Kumar Sandeep , Ramakrishnan Hariharasubramanian , Viswanathan Suresh , Bloomfield Stewart A.
Published: July 2016

We determined whether the structural and functional integrity of amacrine cells (ACs), the largest cohort of neurons in the mammalian retina, are affected in glaucoma. Intraocular injection of microbeads was made in mouse eyes to elevate intraocular pressure as a model of experimental glaucoma. Specific immunocytochemical markers were used to identify AC and displaced (d)ACs subpopulations in both the inner nuclear and ganglion cell layers, respectively, and to distinguish them from retinal ganglion cells (RGCs). Calretinin‐ and γ‐aminobutyric acid (GABA)‐immunoreactive (IR) cells were highly vulnerable to glaucomatous damage, whereas choline acetyltransferase (ChAT)‐positive and glycinergic AC subtypes were unaffected. The AC loss began 4 weeks after initial microbead injection, corresponding to the time course of RGC loss. Recordings of electroretinogram (ERG) oscillatory potentials and scotopic threshold responses, which reflect AC and RGC activity, were significantly attenuated in glaucomatous eyes following a time course that matched that of the AC and RGC loss. Moreover, we found that it was the ACs coupled to RGCs via gap junctions that were lost in glaucoma, whereas uncoupled ACs were largely unaffected. Our results suggest that AC loss in glaucoma occurs secondary to RGC death through the gap junction–mediated bystander effect. J. Comp. Neurol. 527:159–173, 2019. © 2016 Wiley Periodicals, Inc.
Systematic Measures of Biological Networks I: Invariant Measures and Entropy
Authors: Li Yao , Yi Yingfei
Published: July 2016

This paper is part I of a two‐part series devoted to the study of systematic measures in a complex biological network modeled by a system of ordinary differential equations. As the mathematical complement to our previous work with collaborators, the series aims at establishing a mathematical foundation for characterizing three important systematic measures: degeneracy, complexity, and robustness, in such a biological network and studying connections among them. To do so, we consider in part I stationary measures of a Fokker‐Planck equation generated from small white noise perturbations of a dissipative system of ordinary differential equations. Some estimations of concentration of stationary measures of the Fokker‐Planck equation in the vicinity of the global attractor are presented. The relationship between the differential entropy of stationary measures and the dimension of the global attractor is also given.© 2016 Wiley Periodicals, Inc.
Photoinduced Processes in Self‐Assemblies of Bis‐Porphyrinic Tweezers with an Axially Coordinated Bispyridinofullerene
Authors: Briš Anamarija , Trošelj Pavle , Margetić Davor , Flamigni Lucia , Ventura Barbara
Published: July 2016

Self‐assembled bis(zinc porphyrin)–bispyridinopyrrolidinofullerene coordination complexes were obtained in solution. Two [5]polynorbornane‐bridged bis‐porphyrins were used that differed in the arms containing porphyrin units: whereas 1 has rigid [5]polynorbornane linkers, compound 2 has additional flexible propyl chains. The different geometries of the two hosts affect both the complexation process and the photoreactivity of the final product. Formation of the complexes, characterized by absorption, emission, and NMR spectroscopy, occurs with association constants in the order of 104 and 106 m−1 for bis‐porphyrin tweezers 1 and 2, respectively. The higher flexibility of tweezers 2 accounts for the greater association ability. Full photophysical characterization of the complexes, as well as of suitable models, has been performed by means of steady‐state and time‐resolved optical spectroscopy. Ultrafast luminescence detection and pump–probe transient absorption analysis were used to investigate photoinduced processes within the complexes. The results provide evidence that an electron‐transfer process from the bis‐porphyrin host to the fullerene guest occurs in both complexes, and a slightly longer lifetime of the charge‐separated state is observed in the complex with more flexible host 2.
Fluid Neutral Model for Use in Hybrid Neutral Simulations of a Detached Case
Authors: Horsten N. , Dekeyser W. , Samaey G. , Börner P. , Baelmans M.
Published: July 2016

Two fluid neutral models are compared with a finite volume solution of the kinetic neutral equation for a simplified 1D detached case. The neutral equations are coupled to the plasma equations. The first fluid neutral model assumes that neutral and ion temperature are equal while the second adds a separate neutral energy equation. It is illustrated that both the AMJUEL‐HYDHEL databases and TRIM code can be incorporated. The first model is already accurate giving a maximum relative error of 10% for the target fluxes. Adding an energy equation further decreases this maximum relative error to 5%.
Impurity Seeding in ASDEX Upgrade Tokamak Modeled by COREDIV Code
Authors: Gała̧zka K. , Ivanova‐Stanik I. , Bernert M. , Czarnecka A. , Kallenbach A. , Zagörski R. , ASDEX Upgrade Team
Published: July 2016

The self‐consistent COREDIV code is used to simulate discharges in a tokamak plasma, especially the influence of impurities during nitrogen and argon seeding on the key plasma parameters. The calculations are performed with and without taking into account the W prompt redeposition in the divertor area and are compared to the experimental results acquired on ASDEX Upgrade tokamak (shots #29254 and #29257).

For both impurities the modeling shows a better agreement with the experiment in the case without prompt redeposition. It is attributed to higher average tungsten concentration, which on the other hand seriously exceeds the experimental value. By turning the prompt redeposition process on, the W concentration is lowered, what, in turn, results in underestimation of the radiative power losses. By analyzing the influence of the transport coefficients on the radiative power loss and average W concentration it is concluded that the way to compromise the opposing tendencies is to include the edge‐localized mode flushing mechanism into the code, which dominates the experimental particle and energy balance. Also performing the calculations with both anomalous and neoclassical diffusion transport mechanisms included is suggested.
Accuracy and Convergence of Coupled Finite‐Volume / Monte‐Carlo Codes for Plasma Edge Simulations
Authors: Ghoos K. , Dekeyser W. , Samaey G. , Börner P. , Reiter D. , Baelmans M.
Published: July 2016

Present computational techniques for coupled finite‐volume/Monte‐Carlo codes for plasma edge modeling under ITER or DEMO conditions face serious challenges with respect to computational time and accuracy. In this paper, scaling laws for different error contributions are assessed and practical procedures for error estimation are proposed. First results on a 1D and a 2D test case are discussed.
Hybrid Formulation of Radiation Transport in Optically Thick Divertor Plasmas
Authors: Rosato J. , Marandet Y. , Bufferand H. , Reiter D. , Stamm R.
Published: July 2016

Kinetic Monte Carlo simulations of coupled atom‐radiation transport in optically thick divertor plasmas can be computationally very demanding, in particular in ITER relevant conditions or even larger devices, e.g. for power plant divertor studies. At high (∼ 1015 cm–3) atomic densities, it can be shown that sufficiently large divertors behave in certain areas like a black body near the first resonance line of hydrogen (Lyman α). This suggests that, at least in part, the use of continuum model (radiation hydrodynamics) can be sufficiently accurate, while being less time consuming. In this work, we report on the development of a hybrid model devoted to switch automatically between a kinetic and a continuum description according to the plasma conditions. Calculations of the photo‐excitation rate in a homogeneous slab are performed as an illustration. The outlined hybrid concept might be also applicable to neutral atom transport, due to mathematical analogy of transport equations for neutrals and radiation.
TECXY Study of a Liquid Lithium Divertor for DEMO
Authors: Pełka G. , Chmielewski P. , Zagórski R. , Pericoli‐Ridolfini V. , Viola B.
Published: July 2016

Divertor targets made out of a capillary porous system (CPS) filled with liquid lithium, have been proposed as an alternative to standard, solid state plates. In the current work we simulate the DEMO edge plasma in either a standard single‐null or snowflake divertor configuration. Our tool is the 2D code TECXY.

Lithium ablated from the target plate surface and released into the plasma is shown here to partially screen the incoming heat flux. Lithium's moderate SOL radiation levels suggest additional seeding to be beneficial. Very high heat fluxes to the divertor need to be avoided, as intensive lithium evaporation might unacceptably pollute the plasma.
Core‐SOL Modelling of Neon Seeded JET Discharges with the ITER‐like Wall
Authors: Telesca G. , Ivanova‐Stanik I. , Zagörski R. , Brezinsek S. , Czarnecka A. , Drewelow P. , Giroud C. , Huber A. , Wiesen S. , JET EFDA contributors
Published: July 2016

Five ELMy H‐mode Ne seeded JET pulses have been simulated with the self‐consistent core‐SOL model COREDIV. In this five pulse series only the Ne seeding rate was changed shot by shot, allowing a thorough study of the effect of Ne seeding on the total radiated power and of its distribution between core and SOL tobe made. The increase in the simulations of the Ne seeding rate level above that achieved in experiments shows saturation of the total radiated power at a relatively low radiated‐heating power ratio (frad = 0.60) and a further increase of the ratio of SOL to core radiation, in agreement with the reduction of W release at high Ne seeding level. In spite of the uncertainties caused by the simplified SOL model of COREDIV (neutral model, absence of ELMs and slab model for the SOL), the increase of the perpendicular transport in the SOL with increasing Ne seeding rate, which allows to reproduce numerically the experimental distribution core‐SOL of the radiated power, appears to be of general applicability.
Effect of PFC Recycling Conditions on JET Pedestal Density
Authors: Wiesen S. , Brezinsek S. , Harting D. , Dittmar T. , de la Luna E. , Matveev D. , Schmid K. , JET contributors
Published: July 2016

There is experimental evidence that the pedestal dynamics in type‐I ELMy H‐mode discharges is significantly affected by a change in the recycling conditions at the tungsten plasma‐facing components (W‐PFCs) after an ELM event. The integrated code JINTRAC has been employed to assess the impact of recycling conditions during type‐I ELMs in JET ITER‐like wall H‐mode discharges. By employing a heuristic approach, a model to mimic the physical processes leading to formation and release (i.e. outgassing) of finite near‐surface fuel reservoirs in W‐PFCs has been implemented into the EDGE2D‐EIRENE plasma‐wall interaction code being part of JINTRAC. As main result it is shown, that a delay in the density pedestal build‐up after an ELM event can be provoked by reduced recycling induced by depleted W‐PFC particle near‐surface reservoirs. However the pedestal temperature evolution is barely affected by the change in recycling parameters suggesting that the presented model is incomplete.
Clathrin regulates lymphocyte migration by driving actin accumulation at the cellular leading edge
Authors: Ramírez‐Santiago Guillermo , Robles‐Valero Javier , Morlino Giulia , Cruz‐Adalia Aranzazu , Pérez‐Martínez Manuel , Zaldivar Airen , Torres‐Torresano Mónica , Chichón Francisco Javier , Sorrentino Andrea , Pereiro Eva , Carrascosa José L. , Megías Diego , Sorzano Carlos Oscar S. , Sánchez‐Madrid Francisco , Veiga Esteban
Published: July 2016

Lymphocyte migration, which is essential for effective immune responses, belongs to the so‐called amoeboid migration. The lymphocyte migration is up to 100 times faster than between mesenchymal and epithelial cell types. Migrating lymphocytes are highly polarized in three well‐defined structural and functional zones: uropod, medial zone, and leading edge (LE). The actiomyosin‐dependent driving force moves forward the uropod, whereas massive actin rearrangements protruding the cell membrane are observed at the LE. These actin rearrangements resemble those observed at the immunological synapse driven by clathrin, a protein normally involved in endocytic processes. Here, we used cell lines as well as primary lymphocytes to demonstrate that clathrin and clathrin adaptors colocalize with actin at the LE of migrating lymphocytes, but not in other cellular zones that accumulate both clathrin and actin. Moreover, clathrin and clathrin adaptors, including Hrs, the clathrin adaptor for multivesicular bodies, drive local actin accumulation at the LE. Clathrin recruitment at the LE resulted necessary for a complete cell polarization and further lymphocyte migration in both 2D and 3D migration models. Therefore, clathrin, including the clathrin population associated to internal vesicles, controls lymphocyte migration by regulating actin rearrangements occurring at the LE.
Multiple Reactivity of SnII Complexes Bearing Catecholate and o‐Amidophenolate Ligands
Authors: Chegerev Maxim G. , Piskunov Alexander V. , Maleeva Aryna V. , Fukin Georgy K. , Abakumov Gleb A.
Published: July 2016

The reactivity of tin(II) catecholate complex CatSn (1) (where Cat = 3,6‐di‐tert‐butylcatecholate dianion) and two o‐amidophenolate complexes DippAPSn (2) and PhAPSn (3) [where DippAP = 4,6‐di‐tert‐butyl‐N‐(2,6‐diisopropylphenyl)amidophenolate; PhAP = 4,6‐di‐tert‐butyl‐N‐(phenyl)amidophenolate dianions] towards different reagents is reported. Products of the insertion of 1 and 2 into the S–S bond of tetramethylthiuram disulfide were obtained and characterised by X‐ray diffraction analyses. The low temperature oxidation of complexes 1 and 2 with 2‐ethoxy‐3,6‐di‐tert‐butylphenoxy radical enabled us to detect formation of paramagnetic tin(II) derivatives containing the radical‐anion form of the redox‐active ligand. The reaction of tin derivative 3 with Ni(CO)4 leads to substitution of one of the CO groups in the latter with the formation of a new bimetallic product.
Enantioselective Catalysis by Chiral Isothioureas
Authors: Merad Jérémy , Pons Jean‐Marc , Chuzel Olivier , Bressy Cyril
Published: July 2016

This review covers recent developments relating to organocatalyzed transformations by chiral isothioureas (ITUs) since their original introduction by Birman in 2006. This class of nucleophilic heterocycles was first involved in anhydride activation in enantioselective acyl transfer reactions, but it was more recently shown that activation of other reagents was possible, considerably enlarging their number of catalytic enantioselective transformations. Four main modes of activation as Lewis bases can currently be listed: (1) acylisothiouronium intermediates involved in acyl transfer, (2) silylisothiouronium species involved in silyl transfer, (3) acylisothiouronium enolates involved in several concerted and formal pericyclic transformations, and (4) α,β‐unsaturated acylisothiouronium species involved in domino transformations. This review is organized according to these different modes of activation of chiral isothioureas.
Copper(II) Trifluoromethanesulfonate Catalyzed Hydroamination Cyclization–Dimerization Cascade Reaction of Homopropargylic Amines for the Construction of Complex Fused Nitrogen‐Containing Tetracycles
Authors: Liu Lingyan , Wang Chan , Liu Qiangqiang , Kong Yuanfang , Chang Weixing , Li Jing
Published: July 2016

A Cu(OTf)2‐catalyzed cascade cyclization reaction of simple homopropargylic amines was developed. The sequence involved an intramolecular radical hydroamination cyclization followed by dimerization by a Povarov‐type reaction. Through this cascade reaction, a complex nitrogen‐containing tetracycle framework was constructed in one pot with the formation of four new bonds and five stereocenters. Noteworthy, the aglycon of the natural product incargranine B was facilely and efficiently synthesized by using this method.
Self‐transcendence as a psychological parenthood motive: When mortality salience increases the desire for non‐biological children
Authors: Hoppe Annedore , Fritsche Immo , Koranyi Nicolas
Published: July 2016

Reminders of existential threat increase people's desire for offspring. In line with terror management theory, we explain these effects by the motivation to transcend the self via offspring that complements biological accounts of reproduction motivation under threat. Accordingly, Study 1 shows that mortality salience increases self‐transcendence motivation but not other parenthood motivations. Furthermore, mortality salience increased willingness to adopt children (Study 2) or a 14‐year‐old child (Study 3) only for those participants who were told that the personality of children is the product of nurture (and thus determined by their parent's self). In addition, mortality salience increased general willingness to adopt, irrespective of whether nurture or genetic influence was made salient in Study 3, where participants imagined being unable to have biological offspring. We discuss how these findings contribute to explaining increased reproduction intentions under existential threat and processes of terror management.
Large‐Temperature‐Invariant and Electrocaloric Performance of Modified Barium Titanate for Solid‐State Refrigeration
Authors: Patel Satyanarayan , Chauhan Aditya , Vaish Rahul
Published: July 2016

Enormous advances have been made to enhance the electrocaloric responses of ferroelectric materials, and new advanced composites transcend the 50 K mark. However, such progress has ignored the need for temperature‐invariant performance, which is essential for continuous cooling. In this regard, we propose the use of Sr‐modified bulk ceramics with the nominal composition Ba0.85Ca0.15−xSrxTi0.9Zr0.1O3 (0<x<0.15). The material with x=0.075 displayed electrocaloric cooling of (0.7±0.05) K over a wide temperature range of 60 K (303–363 K) at 33 kV cm−1.