bluuebunny/crossref_metadata_2025_split huggingface dataset:
Catalytic Enantioselective Conjugate Alkynylation of α,β‐Unsaturated 1,1,1‐Trifluoromethyl Ketones with Terminal Alkynes
Authors: Sanz‐Marco Amparo , Blay Gonzalo , Muñoz M. Carmen , Pedro José R. 
Published: June 2016

AbstractThe first catalytic enantioselective conjugate alkynylation of α,β‐unsaturated 1,1,1‐trifluoromethyl ketones has been carried out. Terminal alkynes and 1,3‐diynes were treated with trifluoromethyl ketones in the presence of a low catalytic load of a CuI‐MeOBIPHEP complex (2.5 mol %) and triethylamine (10 mol %) to give the corresponding trifluoromethyl ketones bearing a propargylic stereogenic center at the β position with good yields and excellent enantiomeric excesses in most of the cases. No 1,2‐addition products were formed under the reaction conditions. The procedure showed broad substrate scope for alkyne, diyne, and enone. A rationale for the observed stereochemistry has been provided. Finally, the potential application of the reaction products in the synthesis of chiral tetrahydrofurans bearing a trifluoromethylated quaternary stereocenter has been devised.
Ethyl Lithiodiazoacetate: Extremely Unstable Intermediate Handled Efficiently in Flow
Authors: Müller Simon T. R. , Hokamp Tobias , Ehrmann Svenja , Hellier Paul , Wirth Thomas 
Published: June 2016

AbstractEthyl diazoacetate (EDA) is one of the most prominent diazo reagents. It is frequently used in metal–carbene‐type reactions. However, EDA can also be used as a nucleophile under base catalysis. Whilst the addition of EDA to aldehydes can be performed using organic bases, the addition of EDA to other carbonyl electrophiles requires the use of organometallics such as lithium diisopropylamide (LDA). The generated ethyl lithiodiazoacetate is highly reactive and decomposes rapidly, even at low temperatures. Herein, we report a continuous flow protocol that overcomes the problems associated with the instantaneous decomposition of ethyl lithiodiazoacetate. The addition of ethyl lithiodiazoacetate to ketones provides direct access to tertiary diazoalcohols in good yields.
Facile Preparation and Lithium Storage Properties of TiO2@Graphene Composite Electrodes with Low Carbon Content
Authors: Guo Sheng‐qi , Zhen Meng‐meng , Liu Lu , Yuan Zhi‐hao 
Published: June 2016

AbstractOver the past decade, TiO2/graphene composites as electrodes for lithium ion batteries have attracted a great deal of attention for reasons of safety and environmental friendliness. However, most of the TiO2/graphene electrodes have large graphene content (9–40 %), which is bound to increase the cost of the battery. Logically, reducing the amount of graphene is a necessary part to achieve a green battery. The synthesis of TiO2 nanosheets under solvothermal conditions without additives is now demonstrated. Through mechanical mixing TiO2 nanosheets with different amount of reduced graphene (rGO), a series of TiO2@graphene composites was prepared with low graphene content (rGO content 1, 2, 3, and 5 wt %). When these composites were evaluated as anodes for lithium ion batteries, it was found that TiO2+3 wt % rGO manifested excellent cycling stability and a high specific capacity (243.7 mAh g−1 at 1 C; 1 C=167.5 mA g−1), and demonstrated superior high‐rate discharge/charge capability at 20 C.
Oxidative Addition to Gold(I) by Photoredox Catalysis: Straightforward Access to Diverse (C,N)‐Cyclometalated Gold(III) Complexes
Authors: Tlahuext‐Aca Adrian , Hopkinson Matthew N. , Daniliuc Constantin G. , Glorius Frank 
Published: June 2016

AbstractHerein, we report the oxidative addition of aryldiazonium salts to ligand‐supported gold(I) complexes under visible light photoredox conditions. This method provides experimental evidence for the involvement of such a process in dual gold/photoredox‐catalyzed reactions and delivers well‐defined (C,N)‐cyclometalated gold(III) species. The remarkably mild reaction conditions and the ability to widely vary the ancillary ligand make this method a potentially powerful synthetic tool to access diverse gold(III) complexes for systematic studies into their properties and reactivity. Initial studies show that these species can undergo chloride abstraction to afford Lewis acidic dicationic gold(III) species.
ChemInform Abstract: Aminooxylation Horner—Wadsworth—Emmons Sequence for the Synthesis of Enantioenriched γ‐Functionalized Vinyl Sulfones.
Authors: Doherty William , Evans Paul 
Published: June 2016

AbstractThe oxidative addition reaction of unbranched aldehydes with nitrobenzene in the presence of enantiopure proline, followed by a Horner—Wadsworth—Emmons olefination with sulfonyl phosphonate (II) gives γ‐hydroxyvinyl sulfones with excellent enantioselectivities.
ChemInform Abstract: Synthesis of 2,3‐Dihydroquinazolinones and Quinazolin‐4(3H)‐ones Catalyzed by Graphene Oxide Nanosheets in an Aqueous Medium: “On‐Water” Synthesis Accompanied by Carbocatalysis and Selective C—C Bond Cleavage.
Authors: Kausar Nazia , Roy Indranil , Chattopadhyay Dipankar , Das Asish R. 
Published: June 2016

AbstractThe employed catalyst can be easily recycled with a recovery amount of 90% after the fifth run.
Grauwasserreinigung mit einer Sumpfpflanzenmatte unter Praxisbedingungen
Authors: Zehnsdorf Andreas , Stock Norman , Richter Juliane , Blumberg Michael , Müller Roland A. 
Published: June 2016

AbstractDie dezentrale Behandlung von Grauwasser findet weltweit immer größere Beachtung. Da in der Regel ebenerdige Flächen kostenintensiv sind, kann alternativ die Grauwasserbehandlung mithilfe von Sumpfpflanzenmatten auf Gebäudedächern erfolgen. Neben der Wasserbehandlung wirkt sich dieses Vorgehen positiv auf die Gebäudeklimatisierung aus. In einem Test unter Praxisbedingungen konnte gezeigt werden, dass eine Sumpfpflanzenmatte mit 0,1 m Wurzelschichthöhe bei hydraulischen Flächenbelastungen bis 15 L m−2d−1 für die Behandlung von typischem Grauwasser eines Wohnhauses geeignet ist.
How do you write and present research well? 15—Prepare to say less than you prepare
Authors: Tavares Jason R. , Boffito Daria C. , Patience Paul A. , Patience Gregory S. 
Published: June 2016

If you speak too quickly, audience members may lose interest because they cannot follow what you are saying. If you speak too slowly, their minds can wander and you might see them heading for the exit or reaching for their electronic devices. What is the optimal speed in words per minute of a presentation?[1,2]

less than 90
between 90 and 130
between 120 and 160
more than 160
Racial disparities in survival among patients with advanced renal cell carcinoma in the targeted therapy era
Authors: Rose Tracy L. , Deal Allison M. , Krishnan Bhavani , Nielsen Matthew E. , Smith Angela B. , Kim William Y. , Milowsky Matthew I. 
Published: June 2016

BACKGROUNDHistorically, African American (AA) patients with renal cell carcinoma (RCC) have had inferior survival compared with Caucasian patients. Recent studies suggest that the survival disparity between races may be worsening since the advent of targeted therapies for RCC. In this study, survival rates among AA and Caucasian patients with advanced RCC are examined over time to determine whether a disparity in survival persists in the targeted therapy era.METHODSThe authors identified patients with stage IV RCC in the National Cancer Data Base and compared survival between AA and Caucasian patients during the periods before (1998‐2004) and after (2006‐2011) the advent of targeted therapy.RESULTSIn total, 48,846 patients were identified, and 10% were AA. Three‐year survival among both AA and Caucasian patients improved between the 2 periods (P < .01 for both), with no interaction observed between race and improved survival over time (P = .15). The adjusted hazard ratio (HR) for death among AAs compared with Caucasians was 1.13 (95% confidence interval, 1.08‐1.19) in the post‐targeted therapy era, which was unchanged from the pretargeted therapy era (adjusted HR, 1.10; 95% confidence interval, 1.04‐1.15). The adjusted HR was similar when the analysis was restricted to those who received systemic therapy.CONCLUSIONSBoth AA and Caucasian patients with advanced RCC have had a significant improvement in survival since the advent of targeted therapy. However, AA patients maintain a survival disadvantage compared with Caucasians independent of treatment received, potentially related to unmeasured comorbidities, disease burden, or tumor biology. Cancer 2016;122:2988‐2995. © 2016 American Cancer Society.
Agenesis of the corpus callosum in Nogo receptor deficient mice
Authors: Yoo Seung‐Wan , Motari Mary G. , Schnaar Ronald L. 
Published: June 2016

ABSTRACTThe corpus callosum (CC) is the largest fiber tract in the mammalian brain, linking the bilateral cerebral hemispheres. CC development depends on the proper balance of axon growth cone attractive and repellent cues leading axons to the midline and then directing them to the contralateral hemisphere. Imbalance of these cues results in CC agenesis or dysgenesis. Nogo receptors (NgR1, NgR2, and NgR3) are growth cone directive molecules known for inhibiting axon regeneration after injury. We report that mice lacking Nogo receptors (NgR123‐null mice) display complete CC agenesis due to axon misdirection evidenced by ectopic axons including cortical Probst bundles. Because glia and glial‐derived growth cone repellent factors (especially the diffusible factor Slit2) are required for CC development, their distribution was studied. Compared with wild‐type mice, NgR123‐null mice had a sharp increase in the glial marker glial fibrillary acidic protein (GFAP) and in Slit2 at the glial wedge and indusium griseum, midline structures required for CC formation. NgR123‐null mice displayed reduced motor coordination and hyperactivity. These data are consistent with the hypotheses that Nogo receptors are membrane‐bound growth cone repellent factors required for migration of axons across the midline at the CC, and that their absence results directly or indirectly in midline gliosis, increased Slit2, and complete CC agenesis. J. Comp. Neurol. 525:291–301, 2017. © 2016 Wiley Periodicals, Inc.
Scopine Isolated in the Gas Phase
Authors: Écija Patricia , Vallejo‐López Montserrat , Uriarte Iciar , Basterretxea Francisco J. , Lesarri Alberto , Fernández José A. , Cocinero Emilio J. 
Published: June 2016

AbstractThe rotational spectrum of the tropane alkaloid scopine is detected by Fourier transform microwave spectroscopy in a pulsed supersonic jet. A nonconventional method for bringing the molecules intact into the gas phase is used in which scopine syrup is mixed with glycine powder and the solid mixture is vaporized with an ultrafast UV laser beam. Laser vaporization prevents the easy isomerization to scopoline previously observed with conventional heating methods. A single conformer is unambiguously observed in the supersonic jet and corresponds to the energetically most stable species according to quantum chemical calculations. Rotational and centrifugal distortion constants are accurately determined. The spectrum shows fine and hyperfine structure due to the hindered rotation of the methyl group and the presence of a quadrupolar nucleus (14N), respectively. This additional information allows the angle of N‐methyl inversion between the N−CH3 bond and the bicyclic C‐N‐C plane to be determined (131.8–137.8°), as well as the internal rotation barrier of the methyl group (6.235(1) kJ mol−1).
Ro‐vibrational Spectra of (para‐H2)N‐CH4 in He Droplets
Authors: Hoshina Hiromichi , Sliter Russell , Ravi Aakash , Kuma Susumu , Momose Takamasa , Vilesov Andrey F. 
Published: June 2016

AbstractIn this work, we report on the infrared spectroscopic study of clusters of CH4 molecules with up to N=80 para‐hydrogen molecules assembled inside He droplets. Upon increase of the number of the added para‐hydrogen molecules up to about N=12, both the rotational constant, B, and the origin frequency of the υ3 band of CH4 decrease gradually. In the range of 6 ≤N≤12, the spectra indicate some abrupt changes of B and υ3 with both values being approximately constant at N≥12. The origin of this effect is discussed. Comparison of the spectra of methane molecules in para‐hydrogen clusters to that in solid para‐hydrogen is also presented.
Controlled Movement of Cucurbiturils in Host–Guest Systems
Authors: Zhu Liangliang , Zhu Mingjie , Zhao Yanli 
Published: June 2016

AbstractControllable host–guest assemblies play a key role in developing supramolecular materials. This review highlights recent research progress for a type of host–guest systems based on cucurbiturils (CBs) and their derivatives, in which their structural states and related properties can be tuned in response to relative movements of CBs driven by a variety of external stimuli. By taking advantage of unique stimuli‐responsive features, these CB‐based host–guest systems have been grafted into applicable materials, such as biosystems, nanoarchitectures, and functional nanoparticles. In addition to discussing the preparation methodology and structural characterizations of several CB‐based host–guest materials, their charming functionalities, accompanied by variation in the in situ controlled manner and resulting property changes were highlighted. Future studies on the applications of CB‐based, smart, tunable materials are also predicted.
Carbon Dioxide‐Free Hydrogen Production with Integrated Hydrogen Separation and Storage
Authors: Dürr Stefan , Müller Michael , Jorschick Holger , Helmin Marta , Bösmann Andreas , Palkovits Regina , Wasserscheid Peter 
Published: June 2016

AbstractAn integration of CO2‐free hydrogen generation through methane decomposition coupled with hydrogen/methane separation and chemical hydrogen storage through liquid organic hydrogen carrier (LOHC) systems is demonstrated. A potential, very interesting application is the upgrading of stranded gas, for example, gas from a remote gas field or associated gas from off‐shore oil drilling. Stranded gas can be effectively converted in a catalytic process by methane decomposition into solid carbon and a hydrogen/methane mixture that can be directly fed to a hydrogenation unit to load a LOHC with hydrogen. This allows for a straight‐forward separation of hydrogen from CH4 and conversion of hydrogen to a hydrogen‐rich LOHC material. Both, the hydrogen‐rich LOHC material and the generated carbon on metal can easily be transported to destinations of further industrial use by established transport systems, like ships or trucks.
Understanding of Hysteresis Behaviors at the L‐H‐L Transitions in Tokamak Plasma Based on Bifurcation Concept
Authors: Chatthong B. , Onjun T. 
Published: June 2016

AbstractThe hysteresis behaviour at the L‐H‐L transitions in tokamak plasma is investigated based on bifurcation concept. The formation of an edge transport barrier (ETB) is modeled via thermal and particle transport equations with the flow shear suppression effect on anomalous transport included. The anomalous transport is modeled based on critical gradients threshold and the flow shear is calculated from the force balance equation, couples the two transport equations leading to a non‐linear behaviour. Analytical investigation reveals that the fluxes versus gradients space exhibits bifurcation behaviour with s ‐curve soft bifurcation type. Apparently, the backward H‐L transition occurs at lower values than that of the forward L‐H transition, illustrating hysteresis behaviour. The hysteresis properties, i.e. locations of threshold fluxes, gradients and their ratios are analyzed as a function of neoclassical and anomalous transport values and critical gradients. It is found that the minimum heat flux for maintaining H ‐mode depends on several plasma parameters including the strength of anomalous transport and neoclassical transport. In particular, the hysteresis depth becomes larger when neoclassical transport decreases or anomalous transport increases. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of Multi‐Species Ions on Sheath and Presheath in a Magnetic Field Decreasing toward a Wall
Authors: Fukano A. , Nishioka S. , Goto I. , Hatayama A. 
Published: June 2016

AbstractIn the divertor region, the plasma contains deuterium (D) ion and tritium (T) ion in an open magnetic field. The effect of D ion and T ion on the electric potential near the wall in plasma with magnetic field decreasing toward a wall is investigated analytically. The distribution of the electric potential is obtained by plasma‐sheath equation, where D ion and T ion are considered. The potential distribution depends on the parameters such as the profile of the magnetic field, the temperatures of D ion and T ion, and the amount rate of T ion to D ion. The particle distribution also is shown. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulations of Tungsten Re‐deposition Using a Particle‐In‐Cell Code with Non‐uniform Super Particle Sizes
Authors: Ibano K. , Togo S. , Lang T. L. , Ogawa Y. , Lee H.T. , Ueda Y. , Takizuka T. 
Published: June 2016

AbstractTungsten (W), a promising candidate as divertor plasma facing material in magnetic fusion devices, is anticipated to promptly redeposit when sputtered or evaporated from surface due to its small ionization energy and long gyro radius. Using an artificial factor for the reaction cross sections, effects of ionization lengths to the re‐deposition rate was studied by a newly developed particle‐in‐cell code. Treating numbers of particles in a super particle, electric charge, and mass as particle variables in the code, a special scheme for ionization and recombination was developed and used for the calculation. Simulations on W test particles with imaginary properties (neglecting the electric force) revealed the effects of ejection angles. Simulations with secondary electrons from surface showed that the sheath potential is weakened and the re‐deposition rate becomes small. It was found that the multi‐ionization as well as the ionization mean‐free‐path influences the re‐deposition rate in both simulations. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulation of Radiative Divertor Plasmas by Ar Seeding with the Full W‐Wall in JT‐60SA
Authors: Kawashima H. , Shimizu K. , Hoshino K. , Nakano T. , Asakura N. 
Published: June 2016

AbstractRadiative divertor plasmas for JT‐60SA with a full tungsten (W) wall, which is one of options in future, have been simulated with a SOL/divertor integrated code, SONIC. A conventional modified‐coronal radiation (MCR) model with a finite confinement time is used for both Ar and W for the purpose of wide‐range parameter surveys for the divertor plasma to obtain the required conditions (qt ≤ 10 MW/m2, nSepe–mid = 3∼8×1019 m–3,Prad< ∼ 30 MW), saving the calculation time. At low W density ratio (nW /ni = 1×10–5), due to low radiative power from W ions, Ar density ratio (nAr/ni ≥ 1.0× 10–3) and a strong gas puff (Γp ≥ 3.0×1022 s–1) are inevitable to suppress the divertor heat flux down to 10 MW/m2. Increasing nW/ni to 1×10–3 in the divertor region, the divertor heat load becomes low and the operative regions are expanded. While, the W production shall be suppressed since the W radiation is increased with replacement of Ar radiation and the particle recycling decreased. A Monte‐Carlo module (IMPMC) implemented in SONIC for Ar seeding reveals that the spatial distribution of Ar ions is predominantly determined by shell structures of the Ar ions. The consistency between IMPMC and MCR calculations is demonstrated for the averaged n Ar/n i ratio, the electron density and temperature profiles on the divertor target and typical parameter such as the divertor heat load. It shows that the detailed analysis with IMPMC model can be speedily obtained, using a steady state solution obtained by MCR model as an initial state. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ginzburg‐Landau Model in a Finite Shear‐Layer and Onset of Transport Barrier Nonlinear Oscillations: A Paradigm for TypeIII ELMs
Authors: Leconte M. , Jeon Y.M. , Yun G. S. 
Published: June 2016

AbstractWe study a Reaction‐Diffusion model describing the nonlinear oscillations of a transport barrier in a finite shear‐layer (width dE ≪ a), where a is the plasma minor radius, based on a 1D reduced model derived to explain nonlinear barrier oscillations in 3D turbulence simulations [P. Beyer, S. Benkadda, G. Fuhr‐Chaudier et al., Phys. Rev. Lett. 94, 105001 (2005)]. We show that this single nonlinear equation encompasses most of the physics of these barrier relaxations. The nonlinear oscillations have common characteristics with type‐III edge localized modes (ELMs), such as a repetition frequency which decreases with increasing power. In addition to the flow shear, the shear‐layer width is also shown to control the nature of the oscillations. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Gyrokinetic Model beyond the Standard Ordering
Authors: Miyato N. 
Published: June 2016

AbstractAn energy‐conserving reduced kinetic model is formulated which is valid for perturbations with large amplitude and long wavelength beyond the standard gyrokinetic ordering. The standard gyrokinetic model is elegantly formulated by the two‐step phase space transformation consisting of the guiding‐center and gyro‐center transformations, but the amplitude of perturbations is assumed to be small in return for use of the two‐step transformation. Besides, the wavelength of perturbations is assumed to be short in deriving the gyrokinetic Poisson equation. Both limitations are relaxed by using the modified guiding‐center 1‐form for flowing plasmas [Miyato et al., J. Phys. Soc. Jpn. 78, 104501 (2009)]. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Can trait patterns along gradients predict plant community responses to climate change?
Authors: Guittar John , Goldberg Deborah , Klanderud Kari , Telford Richard J. , Vandvik Vigdis 
Published: June 2016

AbstractPlant functional traits vary consistently along climate gradients and are therefore potential predictors of plant community response to climate change. We test this space‐for‐time assumption by combining a spatial gradient study with whole‐community turf transplantation along temperature and precipitation gradients in a network of 12 grassland sites in Southern Norway. Using data on eight traits for 169 species and annual vegetation censuses of 235 turfs over 5 yr, we quantify trait‐based responses to climate change by comparing observed community dynamics in transplanted turfs to field‐parameterized null model simulations. Three traits related to species architecture (maximum height, number of dormant meristems, and ramet‐ramet connection persistence) varied consistently along spatial temperature gradients and also correlated to changes in species abundances in turfs transplanted to warmer climates. Two traits associated with resource acquisition strategy (SLA, leaf area) increased along spatial temperature gradients but did not correlate to changes in species abundances following warming. No traits correlated consistently with precipitation. Our study supports the hypothesis that spatial associations between plant traits and broad‐scale climate variables can be predictive of community response to climate change, but it also suggests that not all traits with clear patterns along climate gradients will necessarily influence community response to an equal degree.