bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractThe 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

AbstractPerfluorophthalocyanines 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractImaging 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

ABSTRACTWe 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.
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

AbstractSelf‐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

AbstractTwo 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

AbstractThe 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

AbstractPresent 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

AbstractKinetic 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

AbstractDivertor 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

AbstractFive 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

AbstractThere 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.
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

AbstractReminders 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

AbstractEnormous 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.
A method for the direct estimation of floor acceleration spectra for elastic and inelastic MDOF structures
Authors: Vukobratović Vladimir , Fajfar Peter 
Published: July 2016

SummaryThis paper deals with floor acceleration spectra, which are used for the seismic design and assessment of acceleration‐sensitive equipment installed in buildings. In design codes and in practice, not enough attention has been paid to the seismic resistance of such equipment. An ‘accurate’ determination of floor spectra requires a complex and quite demanding dynamic response history analysis. The purpose of the study presented in this paper is the development of a direct method for the determination of floor acceleration spectra, which enables their generation directly from the design spectrum of the structure, by taking into account the structure's dynamic properties. The method is also applicable to inelastic structures, which can greatly improve the economic aspects of equipment design. A parametric study of floor acceleration spectra for elastic and inelastic single‐degree‐of‐freedom (SDOF) and multiple‐degree‐of‐freedom structures was conducted by using (non)linear response history analysis. The equipment was modelled as an elastic single‐degree‐of‐freedom system. The proposed method was validated by comparing the results obtained with the more accurate results obtained in a parametric study. Due to its simplicity, the method is an appropriate tool for practice. In the case of inelastic structural behaviour, the method should be used in combination with the N2 method, or another appropriate method for simplified nonlinear structural analysis. Copyright © 2016 John Wiley & Sons, Ltd.