bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural insights into human microsomal epoxide hydrolase by combined homology modeling, molecular dynamics simulations, and molecular docking calculations
Authors: Saenz‐Méndez Patricia , Katz Aline , Pérez‐Kempner María Lucía , Ventura Oscar N. , Vázquez Marta 
Published: January 2017

ABSTRACTA new homology model of human microsomal epoxide hydrolase was derived based on multiple templates. The model obtained was fully evaluated, including MD simulations and ensemble‐based docking, showing that the quality of the structure is better than that of only previously known model. Particularly, a catalytic triad was clearly identified, in agreement with the experimental information available. Analysis of intermediates in the enzymatic mechanism led to the identification of key residues for substrate binding, stereoselectivity, and intermediate stabilization during the reaction. In particular, we have confirmed the role of the oxyanion hole and the conserved motif (HGXP) in epoxide hydrolases, in excellent agreement with known experimental and computational data on similar systems. The model obtained is the first one that fully agrees with all the experimental observations on the system. Proteins 2017; 85:720–730. © 2016 Wiley Periodicals, Inc.
Multiple helical conformations of the helix‐turn‐helix region revealed by NOE‐restrained MD simulations of tryptophan aporepressor, TrpR
Authors: Harish Balasubramanian , Swapna G.V.T. , Kornhaber Gregory J. , Montelione Gaetano T. , Carey Jannette 
Published: January 2017

ABSTRACTThe nature of flexibility in the helix‐turn‐helix region of E. coli trp aporepressor has been unexplained for many years. The original ensemble of nuclear magnetic resonance (NMR structures showed apparent disorder, but chemical shift and relaxation measurements indicated a helical region. Nuclear Overhauser effect (NOE) data for a temperature‐sensitive mutant showed more helical character in its helix‐turn‐helix region, but nevertheless also led to an apparently disordered ensemble. However, conventional NMR structure determination methods require all structures in the ensemble to be consistent with every NOE simultaneously. This work uses an alternative approach in which some structures of the ensemble are allowed to violate some NOEs to permit modeling of multiple conformational states that are in dynamic equilibrium. Newly measured NOE data for wild‐type aporepressor are used as time‐averaged distance restraints in molecular dynamics simulations to generate an ensemble of helical conformations that is more consistent with the observed NMR data than the apparent disorder in the previously reported NMR structures. The results indicate the presence of alternating helical conformations that provide a better explanation for the flexibility of the helix‐turn‐helix region of trp aporepressor. Structures representing these conformations have been deposited with PDB ID: 5TM0. Proteins 2017; 85:731–740. © 2016 Wiley Periodicals, Inc.
Thermodynamic and structural effect of urea and guanidine chloride on the helical and on a hairpin fragment of GB1 from molecular simulations
Authors: Meloni R. , Tiana G. 
Published: January 2017

ABSTRACTWith the help of molecular‐dynamics simulations, we studied the effect of urea and guanidine chloride on the thermodynamic and structural properties of the helical fragment of protein GB1, comparing them with those of its second beta hairpin. We showed that the helical fragment in different solvents populates an ensemble of states that is more complex than that of the hairpin, and thus the associated experimental observables (circular‐dichroism spectra, secondary chemical shifts, m values), that we back‐calculated from the simulations and compared with the actual data, are more difficult to interpret. We observed that in the case of both peptides, urea binds tightly to their backbone, while guanidine exerts its denaturing effect in a more subtle way, strongly affecting the electrostatic properties of the solution. This difference can have consequences in the way denaturation experiments are interpreted. Proteins 2017; 85:753–763. © 2016 Wiley Periodicals, Inc.
Ionic Liquids‐Based Iron Phosphide/Carbon Nanotubes Composites: High Active Electrocatalysts towards Hydrogen Evolution Reaction
Authors: Cui Zehua , Li Tianhao , Tang Daomei , Li Chang Ming 
Published: January 2017

AbstractNew catalyst for hydrogen generation by water electrolysis in aqueous acid is made by mixing N,N‐bis(4‐ (methoxycarbonyl)benzyl)‐N‐methyl‐d‐glucaminium bromide (MBMG−Br) and trichloroferrate (III) to form the iron containing ionic liquid (IL), MBMG‐FeCl3Br. This IL is mixed with carbon nanotubes (CNTs) and sodium hypophosphite (NaH2PO2) and then heated to 300 oC in an inert atmosphere to give the final catalyst, a CNT‐supported iron phosphide (FePMBMG/CNT), which exhibits catalytic activity toward hydrogen evolution reaction in 0.5 M aqueous sulfuric acid electrolyte with a low onset overpotential of 70 mV, a Tafel slope of 75.9 mV dec−1, 95% Faradaic efficiency (FE) and current densities of 10 and 20 mA cm−2, at overpotentials of 155 and 195 mV respectively, for a catalyst loading of 100 μg on 0.2 cm2 of glassy carbon electrode in which the IL to CNTs amount ratio is 1:1.
Efficient Electrochemical Production of Peroxodicarbonate Applying DIACHEM® Diamond Electrodes
Authors: Chardon Chloé P. , Matthée Thorsten , Neuber Rieke , Fryda Matthias , Comninellis Christos 
Published: January 2017

AbstractThe electrochemical synthesis of peroxodicarbonate was performed on boron‐doped DIACHEM® diamond anodes (BDD). The influence of various parameters was studied and promising conditions were determined in an undivided cell design by CONDIAS GmbH. The best performance was obtained with a temperature below room temperature (<18 °C), high current density (720 mA cm−2), high flow velocity (170 cm s−1) and starting concentration close to the maximum solubility of sodium carbonate (1.5 M Na‐carbonate). A high concentration of peroxodicarbonate of 282 mM was obtained with highest current efficiency of about 76%. Future industrial applications appear to be promising. Experiments performed to investigate the bleaching power of the peroxodicarbonate gave promising results. Additionally, a new type of DIACHEM® diamond electrode based on Molybdenum substrate was successfully tested.
Visual Sensing of Ag+ Ions through Gelation of Cholesterol‐ Appended Benzimidazole and Associated Ion Conducting Behaviour
Authors: Ghosh Kumaresh , Panja Santanu , Bhattacharya Subhratanu 
Published: January 2017

AbstractCholesterol‐appended benzimidazole 1 has been synthesized. The gelation ability of the compound 1 has been examined in different solvents and it exhibits strong gelation with silver perchlorate in DMF:H2O (1:1, v/v). Silver ion specific gelation in DMF: H2O highlights the compound 1 as excellent visual detector of Ag+ ions over a series of other metal ions. Furthermore, silver‐induced gel of 1 shows thermally activated ionic conductivity due to the movement of Ag+ ions within the gel network.
Highly Selective Conversion of CO2 to CO Achieved by a Three‐Dimensional Porous Silver Electrocatalyst
Authors: Daiyan Rahman , Lu Xunyu , Ng Yun Hau , Amal Rose 
Published: January 2017

AbstractA three‐dimensional, porous silver foam catalyst was fabricated by a simple electrodeposition approach under high applied currents and vigorous hydrogen evolution conditions. The as‐prepared catalyst can be used directly as the working electrode for electrochemical reduction of CO2 without further treatments, which can reduce CO2 selectively to CO with a high Faradaic Efficiency of 94.7 % and a large current density of 10.80 mA cm−2 at an applied potential of −0.99 V. The performance tradeoff between CO Faradaic Efficiency (FECO) and current density is successfully circumvented with the novel foam structured catalyst, which is capable of delivering high value of FECO as well as large current densities (>10 mA cm−2). The enhanced catalytic performances can be attributed to the unique configuration of the three dimensional, highly porous Ag foam electrode, which not only offers high electrode integrity, conductivity and stability, but also possess large surface area with active sites and easily accessible pores that allow facile transportation of reactants (CO2 and H2O) and products (CO and H2).
Receiver optimization on non‐binary joint sparse graph for OFDM system
Authors: Wen Lei , Wang Tong , Lei Jing 
Published: January 2017

AbstractLow density signature for orthogonal frequency division multiplexing (LDS‐OFDM) is a promising technique for multiple accesses in wireless communications, but its performance is not optimal. In this paper, we study a non‐binary joint sparse graph which combines LDS‐OFDM and non‐binary low density parity check (LDPC) codes, namely non‐binary joint sparse graph for OFDM (NJSG–OFDM). Considering the fact that syndrome computing can be utilized to improve the convergence rate of the joint detection and decoding, syndrome nodes are added to the non‐binary joint sparse graph; consequently, an optimized receiver for the NJSG–OFDM is proposed and analyzed by extrinsic information transfer (EXIT) chart. Simulation results show that the optimized receiver has several advantages such as accelerating the convergence rate of the message passing, improving system performance and alleviating near‐far effect. Copyright © 2017 John Wiley & Sons, Ltd.
The Content and Composition of Total, Free, and Esterified Sterols of Lotus Plumule Oil by GC–MS/FID
Authors: Chen Shuai , Bi Yanlan , Sun Shangde , Chen Jingnan 
Published: January 2017

AbstractThis study investigated the content and composition of total, free, and esterified sterols of three varieties of lotus plumule oil (Hunan lotus, Jiangxi lotus, and Fujian lotus) using GC–MS/FID. The fatty acid composition of sterol fatty acid esters (SFAE) was also analyzed and compared with that of triglycerides. Results showed that total sterol of lotus plumule oil (12.10–14.21 g/100 g) was higher than that of other plant oils (corn germ oil, 1.11 g/100 g; rapeseed oil, 0.78 g/100 g). No significant difference was found among the total sterol contents of the three types of lotus plumule oils (p > 0.05). Most sterol existed in ester forms (81.8–89.1%) rather than in free forms (8.4–10.1%). β‐Sitosterol (71.4–73.4%), and campesterol (6.2–7.5%) were the predominant fractions of free sterols. β‐Sitosterol (41.3–53.7%) and ∆5‐avenasterol (27.1–31.1%) were the predominant fractions of esterified sterols, followed by campesterol (12.1–13.0%) and ∆7‐avenasterol (3.4–3.7%). Linoleic acid (63.6–65.8%), oleic acid (8.3–10.4%), and behenic acid (9.0–9.9%) were the main fatty acids of SFAE, which were different from those of triglycerides. The results from this study suggest that lotus plumule oil may be a good resource of SFAE and can be used as a supplemental ingredient in functional foods.
A two‐year longitudinal study of gender differences in responses to positive affect and depressive symptoms during middle adolescence
Authors: Gomez‐Baya Diego , Mendoza Ramon , Paino Susana , Gillham Jane E. 
Published: January 2017

ABSTRACTThis study aimed to analyze the prospective associations during adolescence between depressive symptoms and response styles to positive affect and to examine gender differences. A longitudinal study was conducted with three waves separated by 1 year each to assess a non‐clinical sample of 622 Spanish adolescents who were 13 and 14 years old (50.2% boys, 49.8% girls). The participants completed self‐report measures of depressive symptoms and responses to positive affect (emotion‐focused positive rumination, self‐focused positive rumination and dampening of positive emotion). The results showed that the increase in depressive symptoms was associated with an increase in dampening and decreases in emotion‐focused and self‐focused positive rumination. Furthermore, girls presented more depressive symptoms, as well as higher dampening and lower self‐focused positive rumination, than boys. The conclusions highlight the need to consider responses to positive affect in explaining gender differences in depressive symptoms during mid‐adolescence, as well as in designing prevention programs.
Alexandria, 1898: Nodes, Networks, and Scales in Nineteenth-Century Egypt and the Mediterranean
Authors: Carminati Lucia 
Published: January 2017

AbstractIn October 1898, the Italian vice-consul in Alexandria charged a group of Italians with participating in an anarchist plot to attack German Emperor Wilhelm II during his planned tour through Egypt and Palestine. This collective arrest produced unexpected outcomes, left a trail of multi-lingual documents, and illuminated specific forms of late nineteenth-century Mediterranean migration. Anarchists were among those who frequently crossed borders and they were well aware of and connected to what was happening elsewhere: they sent letters, circulated manifestos, raised and transported money, and helped fugitive comrades. They maintained nodes of subversion and moved along circuits of solidarity. Similarly, diplomats of Europe, Cairo, Istanbul, and local consular officials operated across borders and cooperated to hunt anarchists down. By following people who were on the move on boats, in post offices, and in taverns, I make a methodological and historiographical argument. First, I examine the Mediterranean as a space of flows and show how theMaghreb/Mashreqdivide in Middle Eastern history has concealed webs and connections. Because anarchists and authorities acted on multiple fronts simultaneously, so must scholarship of this part of the world take account of several histories at once. Second, I look beyond the micro-macro binary to emphasize the interconnections and mutual implications of the micro, the macro, and everything in between. I highlight competing, intersecting, and even contradictory trajectories of some of these anarchist migrants’ belonging. As the affair of the bombs unfolded, all of these contradictions and scales of analysis became visible at once.
Fluid-controlled deformation in blueschist-facies conditions: plastic vs brittle behaviour in a brecciated mylonite (Voltri Massif, Western Alps, Italy)
Authors: MALATESTA C. , FEDERICO L. , CRISPINI L. , CAPPONI G. 
Published: January 2017

AbstractA blueschist-facies mylonite crops out between two high-pressure tectono-metamorphic oceanic units of the Ligurian Western Alps (NW Italy). This mylonitic metabasite is made up of alternating layers with different grain size and proportions of blueschist-facies minerals.The mylonitic foliation formed at metamorphic conditions ofT= 220–310 °C andP= 6.5–10 kbar. The mylonite shows various superposed structures: (i) intrafoliar and similar folds; (ii) chocolate-tablet foliation boudinage; (iii) veins; (iv) breccia.The occurrence of comparable mineral assemblages along the foliation, in boudin necks, in veins and in breccia cement suggests that the transition from ductile deformation (folds) to brittle deformation (veining and breccia), passing through a brittle–ductile regime (foliation boudinage), occurred gradually, without a substantial change in mineral assemblage and therefore in the overallP–Tmetamorphic conditions (blueschist-facies).A strong fluid–rock interaction was associated with all the deformative events affecting the rock: the mylonite shows an enrichment in incompatible elements (i.e. As and Sb), suggesting an input of fluids, released by adjacent high-pressure metasedimentary rocks, during ductile deformation. The following fracturing was probably enhanced by brittle instabilities arising from strain and pore-fluid pressure partitioning between adjacent domains, without further external fluid input.Fluids were therefore fixed inside the rock during mylonitization and later released into a dense fracture mesh that allowed them to migrate through the mylonitic horizon close to the plate interface.We finally propose that the fracture mesh might represent the field evidence of past episodic tremors or ‘slow earthquakes’ triggered by high pore-fluid pressure.
Towards Reforming Nigeria's Secured Transactions Law: The Central Bank of Nigeria's Attempt through the Back Door
Authors: Iheme Williams C , Mba Sanford U 
Published: January 2017

AbstractIn response to the inability of micro, small and medium scale enterprises (MSMEs) to access credit to finance their business operations, the governor of the Central Bank of Nigeria passed the Central Bank of Nigeria (Registration of Security Interests in Movable Property by Banks and Other Financial Institutions in Nigeria) Regulations, No 1, 2015. The purport of this regulation is, among other things, to ensure that MSMEs can use items of personal property to create security. This article critically examines the regulation in the light of the building blocks of article 9 of the US Uniform Commercial Code, which is not only a paradigmatic piece of legislation but appears to be the model on which the Nigerian regulation is based. This critical examination leads the authors to conclude that, although the regulation represents the first steps to reform, much more remains to be done to ensure effectiveness.
Demilitarisation and neutralisation of Svalbard: how has the Svalbard regime been able to meet the changing security realities during almost 100 years of existence?
Authors: Koivurova Timo , Holiencin Filip 
Published: January 2017

ABSTRACTNorway will soon celebrate that 100 years ago, the former ‘no-man's land’ of the Svalbard archipelago was placed under its sovereignty. However, this paper focuses on another important and often omitted element also brought about by the 1920 Svalbard Treaty regarding its demilitarisation and neutralisation. We ask how has the Svalbard security regime been able to meet the various challenges it has faced over almost 100 years of existence? Also, given that the treaty was drafted at the beginning of the 20th century, are the security provisions of this regime already obsolete or are they seen still as valid, and more importantly functional against the backdrop of rapidly changing security realities? This paper then goes further and while it uses Svalbard as a case study, it tries to assess the role of demilitarisation and neutralisation in the modern context by trying to infer possible lessons from two similar regimes, which apply to Antarctica and the Åland Islands.
Multiplexed single-mode wavelength-to-time mapping of multimode light
Authors: Chandrasekharan Harikumar K , Izdebski Frauke , Gris-Sánchez Itandehui , Krstajić Nikola , Walker Richard , Bridle Helen L. , Dalgarno Paul A. , MacPherson William N. , Henderson Robert K. , Birks Tim A. , Thomson Robert R. 
Published: January 2017

AbstractWhen an optical pulse propagates along an optical fibre, different wavelengths travel at different group velocities. As a result, wavelength information is converted into arrival-time information, a process known as wavelength-to-time mapping. This phenomenon is most cleanly observed using a single-mode fibre transmission line, where spatial mode dispersion is not present, but the use of such fibres restricts possible applications. Here we demonstrate that photonic lanterns based on tapered single-mode multicore fibres provide an efficient way to couple multimode light to an array of single-photon avalanche detectors, each of which has its own time-to-digital converter for time-correlated single-photon counting. Exploiting this capability, we demonstrate the multiplexed single-mode wavelength-to-time mapping of multimode light using a multicore fibre photonic lantern with 121 single-mode cores, coupled to 121 detectors on a 32 × 32 detector array. This work paves the way to efficient multimode wavelength-to-time mapping systems with the spectral performance of single-mode systems.
DNA copy number changes define spatial patterns of heterogeneity in colorectal cancer
Authors: Mamlouk Soulafa , Childs Liam Harold , Aust Daniela , Heim Daniel , Melching Friederike , Oliveira Cristiano , Wolf Thomas , Durek Pawel , Schumacher Dirk , Bläker Hendrik , von Winterfeld Moritz , Gastl Bastian , Möhr Kerstin , Menne Andrea , Zeugner Silke , Redmer Torben , Lenze Dido , Tierling Sascha , Möbs Markus , Weichert Wilko , Folprecht Gunnar , Blanc Eric , Beule Dieter , Schäfer Reinhold , Morkel Markus , Klauschen Frederick , Leser Ulf , Sers Christine 
Published: January 2017

AbstractGenetic heterogeneity between and within tumours is a major factor determining cancer progression and therapy response. Here we examined DNA sequence and DNA copy-number heterogeneity in colorectal cancer (CRC) by targeted high-depth sequencing of 100 most frequently altered genes. In 97 samples, with primary tumours and matched metastases from 27 patients, we observe inter-tumour concordance for coding mutations; in contrast, gene copy numbers are highly discordant between primary tumours and metastases as validated by fluorescent in situ hybridization. To further investigate intra-tumour heterogeneity, we dissected a single tumour into 68 spatially defined samples and sequenced them separately. We identify evenly distributed coding mutations in APC and TP53 in all tumour areas, yet highly variable gene copy numbers in numerous genes. 3D morpho-molecular reconstruction reveals two clusters with divergent copy number aberrations along the proximal–distal axis indicating that DNA copy number variations are a major source of tumour heterogeneity in CRC.
Super-Coulombic atom–atom interactions in hyperbolic media
Authors: Cortes Cristian L. , Jacob Zubin 
Published: January 2017

AbstractDipole–dipole interactions, which govern phenomena such as cooperative Lamb shifts, superradiant decay rates, Van der Waals forces and resonance energy transfer rates, are conventionally limited to the Coulombic near-field. Here we reveal a class of real-photon and virtual-photon long-range quantum electrodynamic interactions that have a singularity in media with hyperbolic dispersion. The singularity in the dipole–dipole coupling, referred to as a super-Coulombic interaction, is a result of an effective interaction distance that goes to zero in the ideal limit irrespective of the physical distance. We investigate the entire landscape of atom–atom interactions in hyperbolic media confirming the giant long-range enhancement. We also propose multiple experimental platforms to verify our predicted effect with phonon–polaritonic hexagonal boron nitride, plasmonic super-lattices and hyperbolic meta-surfaces as well. Our work paves the way for the control of cold atoms above hyperbolic meta-surfaces and the study of many-body physics with hyperbolic media.
Design principles for shift current photovoltaics
Authors: Cook Ashley M. , M. Fregoso Benjamin , de Juan Fernando , Coh Sinisa , Moore Joel E. 
Published: January 2017

AbstractWhile the basic principles of conventional solar cells are well understood, little attention has gone towards maximizing the efficiency of photovoltaic devices based on shift currents. By analysing effective models, here we outline simple design principles for the optimization of shift currents for frequencies near the band gap. Our method allows us to express the band edge shift current in terms of a few model parameters and to show it depends explicitly on wavefunctions in addition to standard band structure. We use our approach to identify two classes of shift current photovoltaics, ferroelectric polymer films and single-layer orthorhombic monochalcogenides such as GeS, which display the largest band edge responsivities reported so far. Moreover, exploring the parameter space of the tight-binding models that describe them we find photoresponsivities that can exceed 100 mA W−1. Our results illustrate the great potential of shift current photovoltaics to compete with conventional solar cells.