bluuebunny/crossref_metadata_2025_split huggingface dataset:
Midlatitude ionospheric D region: Height, sharpness, and solar zenith angle
Authors: Thomson Neil R. , Clilverd Mark A. , Rodger Craig J. 
Published: August 2017

AbstractVLF radio amplitude and phase measurements are used to find the height and sharpness of the D region of the ionosphere at a mid to high geomagnetic dip latitude of ~52.5°. The two paths used are both from the 23.4 kHz transmitter, DHO, in north Germany with the first path being northward and mainly over the sea along the west coast of Denmark over a range of ~320–425 km, and the second, also mainly all‐sea, to a single fixed recording receiver at Eskdalemuir in Scotland (~750 km). From plots of the measured amplitudes and phases versus distance for the first of these paths compared with calculations using the U.S. Navy code, ModeFinder, the Wait height and sharpness parameters of the D region at midday in summer 2015 are found to be H′ = 72.8 ± 0.2 km and β = 0.345 ± 0.015 km−1 at a solar zenith angle ~33°. From phase and amplitude measurements at other times of day on the second path, the daytime changes in H′ and β as functions of solar zenith angle are determined from shortly after dawn to shortly before dusk. Comparisons are also made between the modal ModeFinder calculations and wave hop calculations, with both giving similar results. The parameters found here should be useful in understanding energy inputs to the D region from the radiation belts, solar flares, or transient luminous events. The midday values may be sufficiently precise to be useful for monitoring climate change.
Saharan dust, convective lofting, aerosol enhancement zones, and potential impacts on ice nucleation in the tropical upper troposphere
Authors: Twohy C. H. , Anderson B. E. , Ferrare R. A. , Sauter K. E. , L'Ecuyer T. S. , van den Heever S. C. , Heymsfield A. J. , Ismail S. , Diskin G. S. 
Published: August 2017

AbstractDry aerosol size distributions and scattering coefficients were measured on 10 flights in 32 clear‐air regions adjacent to tropical storm anvils over the eastern Atlantic Ocean. Aerosol properties in these regions were compared with those from background air in the upper troposphere at least 40 km from clouds. Median values for aerosol scattering coefficient and particle number concentration >0.3 μm diameter were higher at the anvil edges than in background air, showing that convective clouds loft particles from the lower troposphere to the upper troposphere. These differences are statistically significant. The aerosol enhancement zones extended ~10–15 km horizontally and ~0.25 km vertically below anvil cloud edges but were not due to hygroscopic growth since particles were measured under dry conditions. Number concentrations of particles >0.3 μm diameter were enhanced more for the cases where Saharan dust layers were identified below the clouds with airborne lidar. Median number concentrations in this size range increased from ~100 l−1 in background air to ~400 l−1 adjacent to cloud edges with dust below, with larger enhancements for stronger storm systems. Integration with satellite cloud frequency data indicates that this transfer of large particles from low to high altitudes by convection has little impact on dust concentrations within the Saharan Air Layer itself. However, it can lead to substantial enhancement in large dust particles and, therefore, heterogeneous ice nuclei in the upper troposphere over the Atlantic. This may induce a cloud/aerosol feedback effect that could impact cloud properties in the region and downwind.
Forest Plot
Authors: Lewis Steff C. , Keerie Catriona , Assi Valentina 
Published: August 2017

Abstract
Forest plots are a way of graphically displaying the results of a meta‐analysis. They allow the reader to easily see the results of the individual studies in the meta‐analysis, and how much they are in agreement with one another, alongside the overall result of the meta‐analysis. They can also be used to show subgroup analyses within a meta‐analysis and summarize the results of a group of studies where no meta‐analysis is performed. In addition, they can be used to show subgroup analyses in an individual randomized trial. They have been produced in their current form since the 1980s. It is now possible to draw them in a variety of statistical software packages.
Nanomechanical Characterization of Osteogenic Differentiation of Mesenchymal Stem Cells on Bioactive Peptide Nanofiber Hydrogels
Authors: Topal Ahmet E. , Tansik Gulistan , Ozkan Alper D. , Guler Mustafa O. , Dana Aykutlu , Tekinay Ayse B. 
Published: August 2017

AbstractStem cell differentiation is known to be influenced by the mechanical properties of the surrounding extracellular matrix (ECM); however, little is known about the mechanical phenotypes of differentiating stem cells within the ECM. Here, this study uses osteoinductive, ECM‐mimetic peptide nanofibers to investigate the changes in the mechanical properties of rat mesenchymal stem cells (rMSCs) during osteogenic differentiation. In addition, octafluorocyclobutane (C4F8)‐coated atomic force microscopy (AFM) cantilevers are developed to minimize tip–sample adhesion during the nanomechanical characterization of rMSCs, and osteogenic differentiation is monitored through molecular analysis in conjunction with AFM measurements. rMSCs cultured on osteoinductive peptide nanofibers differentiate at substantially higher rates, form osteogenic cell clusters, deposit calcium to the surrounding matrix, and strikingly increase their Young's moduli throughout the osteogenic differentiation process compared to controls. These results show that the elasticity profiles of differentiating rMSCs may change significantly depending on environmental factors and especially the degree of biomineralization, and that the natural elasticity responses of cells cultured on scaffolds may be considerably different from those observed on non‐bioactive surfaces. This is important for the identification of cell elasticity as a biophysical marker of osteogenic differentiation of MSCs, and indicates that biomineralization might have a predominant role on cell mechanics.
Negligible Electronic Contribution to Heat Transfer across Intrinsic Metal/Graphene Interfaces
Authors: Huang Bin , Koh Yee Kan 
Published: August 2017

AbstractDespite the importance of high thermal conductance (G) of metal/graphene interfaces to thermal management of graphene devices, prior reported G of graphene interfaces is all relatively low. One possible route to improve G of metal/graphene interfaces is through additional heat conduction by electrons, since graphene can be easily doped by metals. In this study, we evaluate the electronic heat conduction across metal/graphene interfaces by measuring G of palladium (Pd)/transferred graphene (trG)/Pd interfaces, prepared by either thermal evaporation or magnetron sputtering. It is found that, for Pd/trG/Pd samples prepared by thermal evaporation, G = 42 MW m−2 K−1 and G only weakly depends on temperature, suggesting that heat is predominantly carried by phonons. However, for Pd/trG/Pd samples prepared by sputtering, a significant increment of G is observed. G = 300 MW m−2 K−1, and is roughly proportional to temperature. We attribute the enhancement of G to an additional channel of heat transport by electrons via atomic‐scale pinholes generated in the graphene by ion bombardment during magetron sputtering. Thus, it is concluded that electrons play a negligible role in heat conduction across intrinsic metal/graphene interfaces, and the contribution of electrons is only substantial if graphene is damaged.
Rhodium(III)‐Catalyzed Tandem C−H Olefination and Oxidative Cyclization of Aromatic Acids with Acrylates for the Synthesis of (E)‐3‐Ylidenephthalides
Authors: Han Wen‐Jing , Pu Fan , Fan Juan , Liu Zhong‐Wen , Shi Xian‐Ying 
Published: August 2017

AbstractIntermolecular tandem C−H olefination/C−O cyclization has been achieved via a rhodium (III)‐catalyzed C−H activation of carboxylic acids with acrylates. This strategy provides the direct and efficient construction of biologically relevant (E)‐3‐ylidenephthalide scaffolds with satisfactory to good yields, and is characterized by stoichiometric reactants, exclusive stereoselectivity, commercially available substrates, mild atmospheric conditions, and short reaction time (less than 2 h).magnified image
Precise Labeling and Tracking of Lipid Droplets in Adipocytes Using a Luminescent ZnSalen Complex
Authors: Tang Juan , Zhang Yanfei , Yin Hao‐Yan , Xu Guoheng , Zhang Jun‐Long 
Published: August 2017

AbstractDesigning two‐photon probes for precise labeling of lipid droplets (LDs) and monitoring LD dynamics in adipocytes is of great significance to understand LD homeostasis. We herein report that a luminescent metal complex LD‐TPZn can specifically image LDs in adipose cells and tissue using one‐ or two‐photon fluorescence microscopy. Importantly, LD‐TPZn exhibited higher specificity to LDs than the commercial dyes Nile Red and Bodipy 493/503, probably due to different cellular uptake pathways, that is, clathrin‐mediated endocytosis and non‐selectively passive diffusion, respectively. More importantly, LD‐TPZn can be applied as a two‐photon LD probe to image adipose tissue, one of the most challengeable tissues for traditional one‐photon fluorescence microscope imaging due to the strong light scattering. Most importantly, LD‐TPZn can be used to monitor LD growth during adipogenesis of preadipocytes, which is highly desirable to unravel the relationship between LD homeostasis and metabolic diseases.
Visual presentation of abstract theoretical concepts using animations in communication systems courses
Authors: Berber Stevan M. , Sowerby Kevin W. 
Published: August 2017

AbstractA new approach to teaching Communication Systems course is proposed, which is based on the use of animations as a complement to the lecture material. The animations are designed to visualize abstract mathematical concepts, related to modulation techniques and communication system analysis in presence of noise, and present these concepts to the students in visual and understandable form in the classroom. The animations have double purpose. They are to be used, firstly, by the lecturers during lecture presentations, and secondly, as an additional aid to the students to support their self‐learning activity. The animations are developed on MATLAB platform.
RTWiFi‐Lab: A real‐time Wi‐Fi laboratory platform on USRP and LabVIEW for wireless communications education and research
Authors: Küçük Kerem 
Published: August 2017

AbstractThe paper presents the real‐time education and research platform as an effective means for describing wireless and digital communications courses with Wi‐Fi standards. To this end, a Real‐Time Wi‐Fi Laboratory platform, called RTWiFi‐Lab is designed and implemented as part of these courses using NI USRP 2921 and LabVIEW. Laboratory experiments of these courses give benefits for utilizing a hardware platform since these experiments greatly facilitate the understanding of significant effects introduced by real‐time receivers. Hence, this platform is presented with seven experiments that provide the various concepts of these courses for different state‐of‐the‐art wireless and digital communications techniques such as signal detection, data modulation, frequency, phase offset estimation, etc. The RTWiFi‐Lab has been considered to provide computer engineering undergraduate students and qualified graduate students with the basic introduction to wireless and digital communications concepts in a short time at Kocaeli University, Turkey.
Start‐and‐Stop Operation of Fixed‐Bed Methanation Reactors – Results from Modeling and Simulation
Authors: Rönsch Stefan , Ortwein Andreas , Dietrich Sebastian 
Published: August 2017

AbstractThe production of synthetic natural gas (SNG) from renewable sources in cases requires a dynamic and intermitted operation of the methanation reactors. This may lead to catalyst damage. Therefore, the present work is aiming at identifying restrictions and optimization approaches of the start‐and‐stop operation of fixed‐bed methanation reactors. 2D modeling and simulation work is conducted and the warm‐start behavior of a fixed‐bed reactor after one to four hours operation intermittence is analyzed. The result reveals the possibility for an operation interruption of up to four hours without high adaptation effort to restart the reactor. After approximately four hours, the catalyst bed at the inlet part of the reactor reaches a temperature that provokes problems for a subsequent warm start.
Understanding the Oxygen Evolution Reaction on a Two‐Dimensional NiO2 Catalyst
Authors: Zaffran Jeremie , Toroker Maytal Caspary 
Published: August 2017

AbstractSolar water splitting is a promising technology to store energy in chemicals but the technology suffers from a lack of efficient catalysts. Nickel oxyhydroxide (NiOOH) is an outstanding catalyst for the oxygen evolution reaction (OER). NiOOH is composed of partially hydrogenated nickel oxide (NiO2) two‐dimensional (2D) sheets that are stacked together. Owing to recent advancements in fabrication it is possible to isolate a single layer of the material. Such 2D catalytic systems are extremely promising, especially due to the wider exposed surface. However their reactivity is not completely understood, and density functional theory (DFT) is an appropriate tool to address that issue. In the current paper we use DFT to model several OER mechanisms. We show that the catalytic activity of these 2D materials is not limited to the defect sites and to the edges, as usually assumed, but rather many reaction centers are available on the NiO2 surface itself. In addition, we will provide evidence for the inhibiting effect of hydrogen ad‐atoms on such layers, thus supporting the necessity of operating in highly basic conditions. The new insights that we are providing here on NiO2 reactivity, and the detailed understanding of the surface mechanisms regarding OER processes, will be key for further developments of 2D tailored catalysts. Indeed, as a main outcome of our work, NiO2 sheets are found to be significantly more reactive than bulk NiOOH itself.
Increased Conformational Flexibility of a Macrocycle–Receptor Complex Contributes to Reduced Dissociation Rates
Authors: Glas Adrian , Wamhoff Eike‐Christian , Krüger Dennis M. , Rademacher Christoph , Grossmann Tom N. 
Published: August 2017

AbstractConstraining a peptide in its bioactive conformation by macrocyclization represents a powerful strategy to design modulators of challenging biomolecular targets. This holds particularly true for the development of inhibitors of protein‐protein interactions which often involve interfaces lacking defined binding pockets. Such flat surfaces are demanding targets for traditional small molecules rendering macrocyclic peptides promising scaffolds for novel therapeutics. However, the contribution of peptide dynamics to binding kinetics is barely understood which impedes the design process. Herein, we report unexpected trends in the binding kinetics of two closely related macrocyclic peptides that bind their receptor protein with high affinity. Isothermal titration calorimetry, 19F NMR experiments and molecular dynamics simulations reveal that increased conformational flexibility of the macrocycle–receptor complex reduces dissociation rates and contributes to complex stability. This observation has impact on macrocycle design strategies that have so far mainly focused on the stabilization of bioactive ligand conformations.
Flower‐like MoSe2/C Composite with Expanded (0 0 2) Planes of Few‐layer MoSe2 as the Anode for High‐Performance Sodium‐Ion Batteries
Authors: Li Jie , Hu Hongxing , Qin Furong , Zhang Peng , Zou Lei , Wang Haobo , Zhang Kai , Lai Yanqing 
Published: August 2017

AbstractSodium‐ion batteries (SIBs) have caught considerable attention in last few years owing to the abundance of sodium in comparison to lithium. The commercial graphite anode is demonstrated unsuitable as an anode material for SIBs due to the larger radius of Na+ ions, whereas the transition metal dichalcogenides (TMDs) show great potential as anodes for SIBs because of their high achievable capacity. The sluggish kinetics, large volume expansion, and aggregation of those materials however results in severe decay of the electrochemical performance. In this work, a flower‐like MoSe2/C composite is synthesized with ethylenediamine and cassava starch (denoted as MoSe2/Ccas) and designed based on these principles: 1) expand the d‐spacing of (0 0 2) planes of MoSe2 to enhance the kinetics for the intercalation‐deintercalation of Na+ ions and 2) embed MoSe2 into the carbon matrix to enhance the conductivity and restrict the volume expansion and aggregation of MoSe2. As a result, MoSe2/Ccas exhibits superior cycle performance and rate capability for sodium storage. It shows durable long‐life cycle capability with a reversible capacity of 360 mAh g−1 after 350 cycles at 0.5 Ag−1. At the current density of 4 Ag−1, the reversible capacity is still maintained at 266 mAh g−1.
C−C and C−N Couplings Following Hydride Addition on Isocyanide Cyclopolyenyl Dimolybdenum Complexes to Give Tethered Aldimine and Aminocarbene Derivatives
Authors: Alvarez Belén , Alvarez M. Angeles , García M. Esther , García‐Vivó Daniel , Ruiz Miguel A. 
Published: August 2017

AbstractReaction of [Mo2Cp2(μ‐κ1:κ1,η6‐PMes*)(CO)2] with S or Se followed by protonation with [H(OEt2)2](BAr′4) gave the cationic derivatives [Mo2Cp2{μ‐κ2P,E:κ1P,η5‐EP(C6H3tBu3)}(CNR)(CO)2](BAr′4) (E=S; R=tBu, iPr, Ph, 4‐C6H4OMe, Xyl; or E=Se; R=tBu; Ar′=3,5‐C6H3(CF3)2). Reaction of the latter with K[BHsBu3] yielded the aldimine complexes [Mo2Cp2{μ‐κ2P,E:κ2P,N,η4‐SP(C6H3tBu3(CHNR))}(CO)2] and their aminocarbene isomers [Mo2Cp2{μ‐κ2P,E:κ2P,C,η4‐SP(C6H3tBu3(NRCH))}(CO)2] (R ≠ Xyl), following C−C and C−N couplings, respectively. Monitoring of these reactions revealed that the initial H− attack takes place at a Cp ligand to give cyclopentadiene intermediates [Mo2Cp{μ‐κ2P,S:κ1P,η5‐SP(C6H3tBu3)}(η4‐C5H6)(CNR)(CO)2], which then undergo C−H oxidative addition to give the hydride isomers [Mo2Cp2{μ‐κ2P,S:κ1P,η3‐SP(C6H3tBu3)}(H)(CNR)(CO)2]. In turn, the latter rearrange to give the aldimine and aminocarbene complexes. DFT calculations revealed that the hydride intermediates first undergo migratory insertion of the isocyanide ligand into the Mo−H bond to give unobservable formimidoyl intermediates, which then evolve either by nucleophilic attack of the N atom on the C6 ring (C−N coupling) or by migratory insertion of the formimidoyl ligand into the C6 ring (C−C coupling). Our data suggest that increasing the size of the substituent R at the isocyanide ligand destabilizes the aldimine isomer to a greater extent, thus favoring formation of the aminocarbene complex.
A Multi‐Level Theoretical Study to Disclose the Binding Mechanisms of Gold(III)–Bipyridyl Compounds as Selective Aquaglyceroporin Inhibitors
Authors: Graziani Valentina , Marrone Alessandro , Re Nazzareno , Coletti Cecilia , Platts James A. , Casini Angela 
Published: August 2017

AbstractStructural studies have paved the avenue to a deeper understanding of aquaporins (AQPs), small ancient proteins providing efficient transmembrane pathways for water, small uncharged solutes such as glycerol, and possibly gas molecules. Despite the numerous studies, their roles in health and disease remain to be fully disclosed. The recent discovery of AuIII complexes as potent and selective inhibitors of aquaglyceroporin isoforms paves the way to their possible therapeutic application. The binding of the selective human AQP3 inhibitor, the cationic complex [Au(bipy)Cl2]+ (Aubipy), to the protein channel has been investigated here by means of a multi‐level theoretical workflow that includes QM, MD and QM/MM approaches. The hydroxo complex was identified as the prevalent form of Aubipy in physiological media and its binding to AQP3 studied by MD. Both non‐covalent and coordinative Aubipy–AQP3 adducts were simulated to probe their role in the modulation of water channel functionality. The electronic structures of representative Aubipy–AQP3 adducts were then analysed to unveil the role played by the metal moiety in their stabilisation. This study spotlights the overall importance of three key aspects for AQP3 inhibition: 1) water speciation of the AuIII complex, 2) stability of non‐covalent adducts and 3) conformational changes induced within the pore by the coordinative binding of AuIII. The obtained results are expected to orient future developments in the design of isoform‐selective AuIII inhibitors.
Dimerization of Endohedral Fullerene in a Superatomic Crystal
Authors: Voevodin Anastasia , Abella Laura , Castro Edison , Paley Daniel W. , Campos Luis M. , Rodríguez‐Fortea Antonio , Poblet Josep M. , Echegoyen Luis , Roy Xavier 
Published: August 2017

AbstractWe describe a solid state material created from the reaction of Ni9Te6(PEt3)8 and Lu3N@C80. The resulting superatomic crystal, [Ni12Te12(PEt3)8]2[(Lu3N@C80)2], contains dimers of Lu3N@C80 that form upon reduction of the fullerene through a single C−C bond at the triple hexagon junctions. The encapsulated Lu3N cluster displays an unprecedented orientation that is collinear and coplanar with the intercage carbon bond. Density functional theory calculations rationalize this unique bonding and relative orientation of the Lu3N clusters. Our structural and theoretical results provide new insights into the effect that the M3N cluster species has on the dimerization process of endohedral fullerenes.
Zn‐, Mg‐, and Li‐TMP Bases for the Successive Regioselective Metalations of the 1,5‐Naphthyridine Scaffold (TMP=2,2,6,6‐Tetramethylpiperidyl)
Authors: Balkenhohl Moritz , Greiner Robert , Makarov Ilya S. , Heinz Benjamin , Karaghiosoff Konstantin , Zipse Hendrik , Knochel Paul 
Published: August 2017

AbstractA set of successive regioselective metalations and functionalizations of the 1,5‐naphthyridine scaffold are described. A combination of Zn‐, Mg‐, and Li‐TMP (TMP=2,2,6,6‐tetramethylpiperidyl) bases and the presence or absence of a Lewis acid (BF3⋅OEt2) allows the introduction of up to three substituents to the 1,5‐naphthyridine core. Also, a novel “halogen dance” reaction was discovered upon metalation of an 8‐iodo‐2,4‐trifunctionalized 1,5‐naphthyridine allowing a fourth regioselective functionalization. Additionally, reactions leading to key 1,5‐naphthyridines for the preparation of OLED materials and a potential antibacterial agent were performed.
Structure‐Guided Design of Peptides as Tools to Probe the Protein–Protein Interaction between Cullin‐2 and Elongin BC Substrate Adaptor in Cullin RING E3 Ubiquitin Ligases
Authors: Cardote Teresa A. F. , Ciulli Alessio 
Published: August 2017

AbstractCullin RING E3 ubiquitin ligases (CRLs) are large dynamic multi‐subunit complexes that control the fate of many proteins in cells. CRLs are attractive drug targets for the development of small‐molecule inhibitors and chemical inducers of protein degradation. Herein we describe a structure‐guided biophysical approach to probe the protein–protein interaction (PPI) between the Cullin‐2 scaffold protein and the adaptor subunits Elongin BC within the context of the von Hippel‐Lindau complex (CRL2VHL) using peptides. Two peptides were shown to bind at the targeted binding site on Elongin C, named the “EloC site”, with micromolar dissociation constants, providing a starting point for future optimization. Our results suggest ligandability of the EloC binding site to short linear peptides, unveiling the opportunity and challenges to develop small molecules that have the potential to target selectively the Cul2‐adaptor PPI within CRLs.