bluuebunny/crossref_metadata_2025_split huggingface dataset:
Linking the Cu(II/I) and the Ni(IV/II) Potentials to Subsequent Passive Film Breakdown for a Cu−Ni Alloy in Aqueous 0.5 M NaCl
Authors: Langley Amelia R. , Elmer Aisling , Fletcher Philip J. , Marken Frank 
Published: December 2019

AbstractCopper and copper–nickel alloys are known to form partially passive films in marine conditions, both naturally and under positive potential bias. Here, the anodic passivation behaviour of copper and of constantan (Cu54Ni45Mn1) as a model for a copper‐nickel alloy are investigated and compared at high positive overpotentials and in 0.5 M NaCl(aq). Abrupt potential‐dependent passive film breakdown is observed for both Cu and Cu−Ni alloys during voltammetry and during chronoamperometry experiments. For Cu, a single transitions occurs at 0.2 V vs. SCE consistent with a Cu(II/I) process, leading to interfacial stress and breaking of a passive CuCl film. For Cu−Ni alloy, two stages are observed at 0.3 V vs. SCE due to a Cu(II/I) process and at 1.7 V vs. SCE due to a sub‐interfacial Ni(IV/II) process. A breakdown mechanism is proposed based on redox processes at the buried interface at the metallic conductor | passive ion conductor junction.
Ultrasonic‐Assisted Synthesis of Highly Defined Silver Nanodimers by Self‐Assembly for Improved Surface‐Enhanced Raman Spectroscopy
Authors: Zhang Junfang , Gim Soeun , Paris Grigori , Dallabernardina Pietro , Schmitt Clemens N. Z. , Eickelmann Stephan , Loeffler Felix F. 
Published: December 2019

AbstractConsiderable research efforts have been devoted to surface‐enhanced Raman spectroscopy (SERS), due to its excellent performance in biosensing and imaging. Here, a novel and facile strategy for the fabrication of well‐defined and uniform nanodimers as SERS substrates is presented. By the assistance of ultrasound, the violent polyol process for particle generation becomes controllable, enabling the self‐assembly of nanostars to nanodimers. Moreover, the aggregation of nanodimers can be easily tuned by post‐ultrasonic treatment, which gives a sensitive substrate for SERS.
Negative‐to‐Positive Thermal Conductivity Temperature Coefficient Transition Induced by Dynamic Fluctuations of the Alkyl Chains in the Layered Complex (C4H9NH3)2CuCl4
Authors: Hoshino Norihisa , Tamura Syunsaku , Akutagawa Tomoyuki 
Published: December 2019

AbstractA negative‐to‐positive transition of the temperature coefficients of thermal conductivity was found in the two‐dimensional organic–inorganic layered complex (C4H9NH3)2CuCl4 (C4CuCl4) over the three structural phase transitions in the range 176–218 K. The coefficients of the low‐temperature phases (85–200 K, α and β phases) were negative, as is typical for insulating crystals, whereas those of the high‐temperature phases (200–300 K, γ and δ phases) were positive, as is typical for glasses and liquids. Single‐crystal X‐ray structure analyses revealed that the tilted C4H9NH3+ chains in the α and β phases were fully outstretched in the δ phase, and the interlayer distances between the CuCl42− planes increased significantly. The γ phase was an intermediate phase that crystallized with an incommensurate structure, in which the CuCl42− sheets formed wave‐like structures consisting of connected alternating regions of β‐like and δ‐like moieties. In the γ and δ phases, thermal fluctuations of the C4H9NH3+ chains were found in the electron density maps; however, powder X‐ray diffraction (PXRD) data indicated that the thermal expansion of the C4H9NH3+ layers was restricted by the rigid CuCl42− layers. This situation was considered to induce glass‐like thermal conducting properties in the material, such as a positive temperature coefficient. The mean free path of the phonons estimated by using the thermal conductivities and heat capacities was a function of T−1 in the range 85–200 K, as would be expected for crystals, whereas it was approximately constant in the range 200–300 K, which is typical of glasses. In addition, the existence of soft vibration modes in the two‐dimensional perovskite CuCl42− sheets was revealed by analysis of the incommensurate crystal structure of the γ phase. These low‐energy vibration modes were believed to induce the cooperative phase transitions, along with the thermal fluctuations and van der Waals interactions in the C4H9NH3+ layers.
Unusual Magneto‐Structural Features of the Halo‐Substituted Materials [FeIII(5‐X‐salMeen)2]Y: a Cooperative [HS‐HS]↔[HS‐LS] Spin Transition
Authors: Al‐Azzani Mariam A. , Al‐Mjeni Faizah , Mitsuhashi Ryoji , Mikuriya Masahiro , Al‐Omari Imaddin A. , Robertson Craig C. , Bill Eckhard , Shongwe Musa S. 
Published: December 2019

AbstractX‐ray structures of the halo‐substituted complexes [FeIII(5‐X‐salMeen)2]ClO4 (X=F, Cl, Br, I) [salMeen=N‐methyl‐N‐(2‐aminoethyl)salicylaldiminate]at RT have revealed the presence of two discrete HS complex cations in the crystallographic asymmetric unit with two perchlorate counter ions linking them by N−Hamine⋅⋅⋅Operchlorate interactions. At 90 K, the two complex cations are distinctly HS and LS, a rare crystallographic observation of this coexistence in the FeIII‐salRen (R=alkyl) spin‐crossover (SCO) system. At both temperatures, crystal packing shows dimerization through C−Himine⋅⋅⋅Ophenolate interactions, a key feature for SCO cooperativity. Moreover, there are noncovalent contacts between the complex cations through type‐II halogen‐halogen bonds, which are novel in this system. The magnetic profiles and Mössbauer spectra concur with the structural analyses and reveal 50 % SCO of the type [HS‐HS]↔[HS‐LS] with a broad plateau. In contrast, [FeIII(5‐Cl‐salMeen)2]BPh4⋅2MeOH is LS and exhibits a temperature‐dependent crystallographic phase transition, exemplifying the influence of lattice solvents and counter ions on SCO.
Reversible Ultra‐Slow Crystal Growth of Mixed Lead Bismuth Perovskite Nanocrystals: The Presence of Dynamic Capping
Authors: Chatterjee Shovon , Dey Pritam , Das Nilimesh , Tiwari Khushubo , Maiti Tanmoy , Sen Pratik 
Published: December 2019

AbstractAn ultra‐slow crystal growth over a period of 24 h of a newly synthesized CH3NH3Pb1/2Bi1/3I3 perovskite (MPBI) nanocrystal in non‐polar toluene medium is reported here. From several spectroscopic techniques as well as from TEM analysis we found that the size of nanocrystals changes continuously with time, in spite of being capped by the ligands. Using a single molecular spectroscopic technique, we also found that this size change is not due to the stacking of nanocrystals but due to crystal growth. The notable temperature dependence and reversible nature of the nanocrystals growth is explained by the dynamic nature of the capping. The observed temperature‐dependent ultra‐slow growth is believed to be a pragmatic step towards controlling the size of perovskite NC in a systematic manner.
Synthesis of (Z)‐β‐(Carbonylamino)alkenylindium through Regioselective anti‐Carboindation of Ynamides and Its Transformation to Multisubstituted Enamides
Authors: Kang Kyoungmin , Sakamoto Kosuke , Nishimoto Yoshihiro , Yasuda Makoto 
Published: December 2019

AbstractThe regioselective anti‐carboindation of ynamides by using InBr3 and silylated nucleophiles was developed to synthesize (Z)‐β‐(carbonylamino)alkenylindiums. The X‐ray crystallographic analysis of an alkenylindium suggested that the reaction proceeded in an anti‐addition fashion. In contrast to reported syn‐carbometalations of ynamides by using organometallics, a cooperation of InBr3 and silylated nucleophiles to ynamides achieved an anti‐addition, which was supported by DFT calculations. The scope of substrates included various ynamides and silylated nucleophiles, such as silyl ketene acetals and silyl ketene imines. The transformation of synthesized alkenylindiums by iodination, radical coupling, and Pd‐catalyzed cross‐coupling successfully afforded trisubstituted enamines with high regio‐ and stereoselectivities.
Electrophysiological models of the human pancreatic δ‐cell: From single channels to the firing of action potentials
Authors: Félix‐Martínez Gerardo J. , González‐Vélez Virginia , Godínez‐Fernández J. Rafael , Gil Amparo 
Published: December 2019

AbstractMinimal mathematical models were developed to describe the electrophysiological properties of human δ‐cells. Markov models of single channels were first developed based on the analysis of electrophysiological data. Monte Carlo simulations of voltage‐clamp experiments were performed in an iteratively optimization procedure to estimate the number of channels required to reproduce the main characteristics of the macroscopic currents recorded experimentally. A membrane model of the firing of action potentials was then developed based on the kinetic schemes of single channels and the number of channels estimated. We showed that macroscopic currents of human δ‐cells can be reproduced by minimal models of single channels when the appropriate number of channels is considered. In addition, our simulations suggest that human δ‐cells are capable of generating action potentials through the interaction of the ionic currents involved. Finally, we determined the relative contribution of the currents underlying the firing of action potentials in human pancreatic δ‐cells, which allowed us to propose a qualitative model of an action potential in terms of the underlying ionic currents.
Duel‐Responsive Hybrid Nanoparticle with Energy Transfer Modulated Near Infrared Emission
Authors: Li Denghao , Li Chaojun , Liu Xiaofeng , Cui Qianling , Xu Shiqing , Qiu Jianrong 
Published: December 2019

AbstractLanthanide (Ln) activated systems are characterized by the rich line‐shaped emission spectra stemming from the parity‐forbidden inner shell f‐f transitions. This inherent nature of Ln ions efficiently stabilizes their emissions against environment perturbations, but always necessitates the use of strong and broadband sensitizer to achieve efficient emission. Here, based on a model near‐infrared (NIR) emitting system – NaYF4 : Nd3+ NPs, we demonstrate sensitized NIR emission by grafting the nanoparticle (NP) surfaces with a visible‐light active organic conjugated oligomer, 4,7‐(9,9′‐bis(4‐carboxybutyl)‐fluorenyl)‐2,1,3‐benzothiadiazole (OFBT). Photoluminescence (PL) emission, excitation and time‐resolved spectra confirm energy transfer from the OFBT molecules to nanoparticles across the organic/inorganic interfaces, and the efficiency of ET is quantitatively determined by the surface coverage of OFBT molecules and concentration of Ln ions in the NPs. By taking advantage of the environment‐sensitive binding strength of OFBT to NP surface, we further demonstrate high sensitivity of the NIR emission from the hybrid NPs to variations in pH and temperature, which is explained by the change in energy transfer efficiency from OFBT to NPs. Therefore, the developed nano‐hybrid systems are believed to have potential applications in sensing and detection in physiological environment.
Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of the Novel Non–Bile Acid FXR Agonist Tropifexor (LJN452) in Healthy Volunteers
Authors: Badman Michael K. , Chen Jin , Desai Sachin , Vaidya Soniya , Neelakantham Srikanth , Zhang Jie , Gan Lu , Danis Kate , Laffitte Bryan , Klickstein Lloyd B. 
Published: December 2019

AbstractTropifexor (LJN452) is a potent, orally available, non–bile acid farnesoid X receptor agonist under clinical development for chronic liver diseases. Here, we present results from a first‐in‐human study of tropifexor following single‐ and multiple‐ascending doses (SAD/MAD) and food effect substudy in healthy volunteers. The SAD study included 6 fasted cohorts receiving 10‐ to 3000‐µg tropifexor or placebo and 1 cohort receiving 300‐µg tropifexor with a high‐fat meal. The MAD study included 4 lean cohorts receiving 10 to 100 µg and 1 obese cohort receiving 30‐µg once‐daily doses or placebo for 14 days. Pharmacodynamic assessment of fibroblast growth factor 19 and fasting plasma lipids was performed after dosing. Overall, 95 volunteers received at least 1 tropifexor or placebo dose. Tropifexor was well tolerated up to 3000 µg and 100 µg in the SAD and MAD studies, respectively; however, 2 subjects discontinued the MAD study due to asymptomatic elevation of liver transaminases. At single doses, tropifexor showed a moderate rate of absorption (median time to maximum concentration, 4 hours), dose‐proportional increases in exposure, and elimination half‐life of 13.5 to 21.9 hours. When taken with food, tropifexor exposure increased by ∼60%. With multiple dosing, steady state was reached on day 4 with <2‐fold accumulation. Single and multiple doses showed dose‐dependent increases in fibroblast growth factor 19. No changes in serum lipids were observed in tropifexor‐ vs placebo‐treated obese subjects. In conclusion, tropifexor was well tolerated, had a pharmacokinetic profile suitable for once‐daily dosing and showed dose‐dependent target engagement without altering plasma lipids in healthy volunteers.
A scalable model for real‐time venue recommendations using MapReduce
Authors: Rehman Faisal , Khalid Osman , Haq Nuhman ul , Maqsood Tahir , Ali Mazhar , Ahmad Raja Wasim , Shuja Junaid , Sarwar Shahzad , Madani Sajjad Ahmad 
Published: December 2019

SummaryThe popular social networks such as Facebook, Twitter, and Foursquare closely monitor user activities to recommend different services and events. Among others, venue recommendation proposes users the most appropriates venues based on the user preferences. It offers facility to the user to mark the check‐ins when a venue is visited. The traditional venue recommendation systems have opted collaborative filtering to propose recommendations. However, collaborative filtering overlooked certain critical issues, including real‐time recommendations, cold start, and scalability, for venue recommendations. Moreover, real‐time physical factors such as distance from the venue are also not considered in traditional venue recommendation systems. Furthermore, parsing and processing of huge volume of unstructured data is the main challenge for conventional recommender systems, particularly when dealing with real‐time recommendations. For efficient scaling, significant computational and storage resources for recommendation systems are desired. This article proposes a Real‐Time Venue Recommendation (RTVR) model that utilizes cloud‐based MapReduce framework to process, compare, mine, and manage large data sets for generating recommendations. The results showed that the proposed model has improved accuracy for real‐time recommendations. The proposed RTVR is more scalable as it exploits a cloud‐based architecture. Moreover, the proposed techniques are verified using formal verification methods.
Halogen and Chalcogen Bond Energies Evaluated Using Electron Density Properties
Authors: Bauzá Antonio , Frontera Antonio 
Published: December 2019

AbstractHalogen (X‐bond) and chalcogen bond (Ch−bond) energies for 36 complexes have been obtained at the RI‐MP2/def2−TZVP level of theory, involving the heavier halogen and chalcogen atoms (Br, I, Se, Te). We have explored the existence of linear relationships between the interaction energies and the local kinetic energy densities at the bond critical points that characterize the σ‐hole interactions (both electronic G(r) and potential V(r) energy densities). Interestingly, we have found strong relationships for halogen and chalcogen bonding energies, especially for the V(r) energy density, thus allowing to estimate the interaction energy without computing the separate monomers. This is also useful to estimate the interaction in monomeric systems (intramolecular X/Ch‐bonds), as illustrated using several examples. Remarkably, we have also found a good relationship when in the same representation both halogen and chalcogen atoms are included, thus allowing to use the same empirical correlation for both interactions.
Cassava Metabolomics and Starch Quality
Authors: Rosado‐Souza Laise , David Laure C. , Drapal Margit , Fraser Paul D. , Hofmann Jörg , Klemens Patrick A. W. , Ludewig Frank , Neuhaus H. Ekkehard , Obata Toshihiro , Perez‐Fons Laura , Schlereth Armin , Sonnewald Uwe , Stitt Mark , Zeeman Samuel C. , Zierer Wolfgang , Fernie Alisdair R. 
Published: December 2019

AbstractCassava plays an important role as a staple food for more than 800 million people in the world due to its ability to maintain relatively high productivity even in nutrient‐depleted soils. Even though cassava has been the focus of several breeding programs and has become a strong focus of research in the last few years, relatively little is currently known about its metabolism and metabolic composition in different tissues. In this article, the absolute content of sugars, organic acids, amino acids, phosphorylated intermediates, minerals, starch, carotenoids, chlorophylls, tocopherols, and total protein as well as starch quality is described based on multiple analytical techniques, with protocols specifically adjusted for material from different cassava tissues. Moreover, quantification of secondary metabolites relative to internal standards is presented using both non‐targeted and targeted metabolomics approaches. The protocols have also been adjusted to apply to freeze‐dried material in order to allow processing of field harvest samples that typically will require long‐distance transport. © 2019 The Authors.Basic Protocol 1: Metabolic profiling by gas chromatography–mass spectrometry (GC‐MS)Support Protocol 1: Preparation of freeze‐dried cassava materialSupport Protocol 2: Preparation of standard compound mixtures for absolute quantification of metabolites by GC‐MSSupport Protocol 3: Preparation of retention‐time standard mixtureBasic Protocol 2: Determination of organic acids and phosphorylated intermediates by ion chromatography–mass spectrometry (IC‐MS)Support Protocol 4: Preparation of standards and recovery experimental procedureBasic Protocol 3: Determination of soluble sugars, starch, and free amino acidsAlternate Protocol: Determination of soluble sugars and starchBasic Protocol 4: Determination of anionsBasic Protocol 5: Determination of elementsBasic Protocol 6: Determination of total proteinBasic Protocol 7: Determination of non‐targeted and targeted secondary metabolitesBasic Protocol 8: Determination of carotenoids, chlorophylls, and tocopherolBasic Protocol 9: Determination of starch quality
Assays for Modulators of Ryanodine Receptor (RyR)/Ca2+ Release Channel Activity for Drug Discovery for Skeletal Muscle and Heart Diseases
Authors: Murayama Takashi , Kurebayashi Nagomi 
Published: December 2019

AbstractThe ryanodine receptor (RyR) is a Ca2+ release channel that is present in the sarcoplasmic reticulum and endoplasmic reticulum (ER) and that plays a central role in excitation‐contraction coupling in skeletal and cardiac muscle. Hyperactivation of RyR by genetic mutations or posttranslational modification can cause various skeletal muscle and arrhythmogenic heart diseases. Inhibitors of RyR are therefore expected to be potential drugs for treatment of such diseases. This article describes assays to evaluate RyR channel activity, including an ER Ca2+ measurement assay that is compatible with high‐throughput screening and a [3H]‐ryanodine binding assay that provides a quantitative measure of RyR channel activity as a second screen for compound hits. © 2019 by John Wiley & Sons, Inc.Basic Protocol 1: [Ca2+]ER assay for ryanodine receptor (RyR) channel activitySupport Protocol 1: Determination of dose dependence and isoform selectivity of RyR inhibitors using [Ca2+]ER assayBasic Protocol 2: [3H]‐Ryanodine binding assay for RyR channel activitySupport Protocol 2: Isolation of microsomes from RyR‐expressing HEK293 cells
Estimation of future power consumption level in smart grid: Application of fuzzy logic and genetic algorithm on big data platform
Authors: Je Seung‐Mo , Huh Jun‐Ho 
Published: December 2019

SummaryIn an environment where the importance of new and renewable energies is growing, the balance between energy production and consumption cannot be achieved easily. Although it is possible for the one with surplus power to supply it to the one experiencing a shortage, power demand can hardly be expected to exceed supply or both to stay at equal levels at all times. In such case, a network limited to an individual or a small group can be regarded as a small single node so that the larger network consisting of these nodes can be represented with a graph based on the topology of dispersed nodes. This situation is similar to the prisoner's dilemma wherein the most ideal situation for the nodes is to collaborate with each other; in a situation wherein betrayal takes place, however, the Nash equilibrium can hardly be expected. Such situation between the nodes is almost the same condition repeatedly laid down to the prisoners who consistently and competitively pursue maximum profit and can be considered a game. Thus, this study attempted to devise a method of gaining maximum profit and predicting future power demands by using a genetic algorithm based on the game theory‐based fuzzy logic that seeks maximum profit by making the best choice. A scheme that can avoid a possible “prisoner's dilemma” situation in a new and renewable energy transaction environment was devised based on the game theory. For such scheme, the fuzzy theory was adopted to reflect the power demand, supply, and values; by developing a greedy algorithm, the optimal values were reflected under each given environment to set a foundation on which the situation wherein the cooperative nodes could be placed at a greater disadvantage than the uncooperative nodes can be avoided with a tit‐for‐tat algorithm wherein the genetic algorithm was reflected as well.
Pesticides in cannabis: A review of analytical and toxicological considerations
Authors: Taylor Amelia , Birkett Jason W. 
Published: December 2019

AbstractA review of the literature surrounding the use, analysis, and detection of pesticide material for cannabis cultivation is presented. The use of pesticides in crop cultivation is not new, and cannabis crops are no exception. Studies have found that the use of these are common and that high levels of the pesticides are transferred into the cannabis smoke. The most common pesticide classes associated with cannabis are insecticides, acaricides, and fungicides. Over 350 different pesticide products may be used on cannabis materials and of these, 16 pesticides and three plant growth regulators (PGR) are considered to be the main candidates. Many of the pesticides found in cannabis samples destined for consumption are classed as moderately hazardous by the World Health Organization. Analytical methods for pesticide detection on cannabis are being developed with a view to implementing quality control of cannabis, where it is legal, before being sold. However, no standardized protocol exists. The pesticide levels found in the cannabis samples tested were generally low (less than μg/g), these results do not, however, provide information on chronic low‐dose adverse effects of pesticides in relation to cannabis consumption. Currently no research exists on the toxicity of pyrolyzed pesticides in humans from smoking cannabis. More studies are needed to further understand this potentially harmful health threat.