bluuebunny/crossref_metadata_2025 huggingface dataset:
Pingpong‐Energietransfer in kovalent verknüpften Porphyrin‐MoS2‐Architekturen
Authors: Canton‐Vitoria Ruben , Scharl Tobias , Stergiou Anastasios , Cadranel Alejandro , Arenal Raul , Guldi Dirk M. , Tagmatarchis Nikos
Published: December 2019

Molybdändisulfid‐Nanoschichten wurden mit Porphyrin kovalent modifiziert und vollständig charakterisiert. Weder die Porphyrin‐Absorption noch die Fluoreszenz wurden durch die kovalente Bindung an MoS2 merklich beeinflusst. Mithilfe transienter Absorptionsspektroskopie konnte jedoch ein komplexer Pingpong‐Energietransfer‐Mechanismus, nämlich vom Porphyrin zum MoS2 und wieder zurück zum Porphyrin, bestätigt werden. Diese Studie zeigt das Potential von Übergangsmetalldichalkogeniden bei Photosensibilisierungsprozessen auf.
Expandierte Carbaporphyrinoide
Authors: Szyszko Bartosz , Latos‐Grażyński Lechosław
Published: December 2019

In diesem Aufsatz sollen die Fortschritte auf dem Gebiet der synthetischen expandierten Carbaporphyrinoide dargelegt werden. Die Entwicklung auf diesem Gebiet wird anhand von expandierten Porphyrin‐verwandten Systemen aufgezeigt, die eine Vielfalt von Bausteinen enthalten, mit deren Hilfe ein oder mehrere Kohlenstoffatome in die Kavität eingeführt werden. Die Ausführungen beginnen mit den Platyrinen – den Makrocyclen, die als Stammmolekül nicht nur der expandierten Carbaporphyrinoide, sondern der Klasse der Carbaporphyrinoide im Allgemeinen gelten. Nach einigen historischen Betrachtungen wird eine Vielzahl von expandierten porphyrinartigen Makrocyclen, die N‐fehlgeordnete oder neo‐fehlgeordnete Pyrrol‐Strukturelemente und verschiedene carbocyclische Untereinheiten enthalten, vorgestellt. Ein besonderer Schwerpunkt wird dabei auf die Anwendungen von expandierten Carbaporphyrinoiden in verschiedenen Bereichen gelegt, z. B. in der Organometallchemie, bei Schaltersystemen oder der Aromatizität. Abschließend wird ein kovalenter Käfig auf der Basis von expandierten Carbaporphyrinoiden vorgestellt.
Self‐Assembly in Water with N‐Substituted Imines
Authors: Jiao Tianyu , Wu Guangcheng , Zhang Yang , Shen Libo , Lei Ye , Wang Cai‐Yun , Fahrenbach Albert C. , Li Hao
Published: December 2019

Imine synthesis has enjoyed a long history as the dynamic covalent reaction of choice for the construction of purely covalent molecular architectures. In organic solvents, the formation of imine bonds is reversible but leads to thermodynamically stable products. In the presence of water, however, imine bonds are labile, a fact which limits their utility as mediators of self‐assembly in aqueous and biological media. In this Review, we discuss water‐compatible dynamic covalent bonds based on N‐substituted imine derivatives, namely hydrazones and oximes, for the self‐assembly of metal‐free organic architectures with well‐defined structures. The reasons why hydrazones and oximes are more robust in water than their parent imines are explained. Recent progress in the self‐assembly, characterization, and design principles of a variety of complex molecules including macrocycles, cages, catenanes, and knots in aqueous media is highlighted. Emerging applications for these molecules, including guest recognition and separations, are also discussed.
Electrochemical Conversion of CO2 to Syngas with Controllable CO/H2 Ratios over Co and Ni Single‐Atom Catalysts
Authors: He Qun , Liu Daobin , Lee Ji Hoon , Liu Yumeng , Xie Zhenhua , Hwang Sooyeon , Kattel Shyam , Song Li , Chen Jingguang G.
Published: December 2019

The electrochemical CO2 reduction reaction (CO2RR) to yield synthesis gas (syngas, CO and H2) has been considered as a promising method to realize the net reduction in CO2 emission. However, it is challenging to balance the CO2RR activity and the CO/H2 ratio. To address this issue, nitrogen‐doped carbon supported single‐atom catalysts are designed as electrocatalysts to produce syngas from CO2RR. While Co and Ni single‐atom catalysts are selective in producing H2 and CO, respectively, electrocatalysts containing both Co and Ni show a high syngas evolution (total current >74 mA cm−2) with CO/H2 ratios (0.23–2.26) that are suitable for typical downstream thermochemical reactions. Density functional theory calculations provide insights into the key intermediates on Co and Ni single‐atom configurations for the H2 and CO evolution. The results present a useful case on how non‐precious transition metal species can maintain high CO2RR activity with tunable CO/H2 ratios.
Highly Efficient Cyclic Dinucleotide Based Artificial Metalloribozymes for Enantioselective Friedel–Crafts Reactions in Water
Authors: Wang Changhao , Hao Min , Qi Qianqian , Dang Jingshuang , Dong Xingchen , Lv Shuting , Xiong Ling , Gao Huanhuan , Jia Guoqing , Chen Yashao , Hartig Jörg S. , Li Can
Published: December 2019

The diverse secondary structures of nucleic acids are emerging as attractive chiral scaffolds to construct artificial metalloenzymes (ArMs) for enantioselective catalysis. DNA‐based ArMs containing duplex and G‐quadruplex scaffolds have been widely investigated, yet RNA‐based ArMs are scarce. Here we report that a cyclic dinucleotide of c‐di‐AMP and Cu2+ ions assemble into an artificial metalloribozyme (c‐di‐AMP⋅Cu2+) that enables catalysis of enantioselective Friedel–Crafts reactions in aqueous media with high reactivity and excellent enantioselectivity of up to 97 % ee. The assembly of c‐di‐AMP⋅Cu2+ gives rise to a 20‐fold rate acceleration compared to Cu2+ ions. Based on various biophysical techniques and density function theory (DFT) calculations, a fine coordination structure of c‐di‐AMP⋅Cu2+ metalloribozyme is suggested in which two c‐di‐AMP form a dimer scaffold and the Cu2+ ion is located in the center of an adenine‐adenine plane through binding to two N7 nitrogen atoms and one phosphate oxygen atom.
On‐surface Synthesis of a Semiconducting 2D Metal–Organic Framework Cu3(C6O6) Exhibiting Dispersive Electronic Bands
Authors: Zhang Ran , Liu Jing , Gao Yifan , Hua Muqing , Xia Bowen , Knecht Peter , Papageorgiou Anthoula C. , Reichert Joachim , Barth Johannes V. , Xu Hu , Huang Li , Lin Nian
Published: December 2019

A 2D metal–organic framework (2D‐MOF) was formed on a Cu(111) substrate using benzenehexol molecules. By means of a combination of scanning tunneling microscopy and spectroscopy, X‐ray photoelectron spectroscopy and density‐functional theory, the structure of the 2D‐MOF is determined to be Cu3(C6O6), which is stabilized by O–Cu–O bonding motifs. We find that upon adsorption on Cu(111), the 2D‐MOF features a semiconductor band structure with a direct band gap of 1.5 eV. The O–Cu–O bonds offer efficient charge delocalization, which gives rise to a highly dispersive conduction band with an effective mass of 0.45 me at the band bottom, implying a high electron mobility in this material.
Controllable Synthesis of Porphyrin‐Based 2D Lanthanide Metal–Organic Frameworks with Thickness‐ and Metal‐Node‐Dependent Photocatalytic Performance
Authors: Jiang Zhong Wei , Zou Yang Chun , Zhao Ting Ting , Zhen Shu Jun , Li Yuan Fang , Huang Cheng Zhi
Published: December 2019

Synthesizing 2D metal–organic frameworks (2D MOFs) in high yields and rational tailoring of the properties in a predictable manner for specific applications is extremely challenging. Now, a series of porphyrin‐based 2D lanthanide MOFs (Ln‐TCPP, Ln=Ce, Sm, Eu, Tb, Yb, TCPP=tetrakis(4‐carboxyphenyl) porphyrin) with different thickness were successfully prepared in a household microwave oven. The as‐prepared 2D Ln‐TCPP nanosheets showed thickness‐dependent photocatalytic performances towards photooxidation of 1,5‐dihydroxynaphthalene (1,5‐DHN) to synthesize juglone. Particularly, the Yb‐TCPP displayed outstanding photodynamic activity to generate O2− and 1O2. This work not only provides fundamental insights into structure designing and property tailoring of 2D MOFs nanosheets, but also pave a new way to improve the photocatalytic performance.
Athermal and Soft Multi‐Nanopatterning of Azopolymers: Phototunable Mechanical Properties
Authors: Yang Bowen , Cai Feng , Huang Shuai , Yu Haifeng
Published: December 2019

Imprinting nanopatterns on flexible substrates has diverse applications in advanced fabrication. However, the traditional thermal nanoimprint lithography (T‐NIL) often causes shrinkage upon cooling. Here, a simple yet versatile method is introduced to fabricate multiple nanopatterns on a flexible substrate coated with an azopolymer by combining athermal nanoimprint lithography (AT‐NIL) and photolithography. The azopolymer has various mechanical properties upon photoirradiation: 1) phototunable glass‐transition temperatures (Tg) and concomitantly photoinduced switch from glassy plastic to viscoplastic polymer; 2) prominent modulation of viscoplasticity under light illumination at different wavelengths. Regionally selective multiple nanopatterns are conveniently fabricated, presenting angle‐dependent structural color images on poly(ethylene terephthalate) (PET) substrates. The flexible, athermal and multiple nanopatterning method has the potential for on‐demand fabrication of complex nanopatterns.
Synthesis and Reactivity of the First Isolated Hydrogen‐Bridged Silanol–Silanolate Anions
Authors: Weitkamp Robin F. , Neumann Beate , Stammler Hans‐Georg , Hoge Berthold
Published: December 2019

We report on the first examples of isolated silanol–silanolate anions, obtained by utilizing weakly coordinating phosphazenium counterions. The silanolate anions were synthesized from the recently published phosphazenium hydroxide hydrate salt with siloxanes. The silanol–silanolate anions are postulated intermediates in the hydroxide‐mediated polymerization of aryl and alkyl siloxanes. The silanolate anions are strong nucleophiles because of the weakly coordinating character of the phosphazenium cation, which is perceptible in their activity in polysiloxane depolymerization.
Ping‐Pong Energy Transfer in Covalently Linked Porphyrin‐MoS2 Architectures
Authors: Canton‐Vitoria Ruben , Scharl Tobias , Stergiou Anastasios , Cadranel Alejandro , Arenal Raul , Guldi Dirk M. , Tagmatarchis Nikos
Published: December 2019

Molybdenum disulfide nanosheets covalently modified with porphyrin were prepared and fully characterized. Neither the porphyrin absorption nor its fluorescence was notably affected by covalent linkage to MoS2. The use of transient absorption spectroscopy showed that a complex ping‐pong energy‐transfer mechanism, namely from the porphyrin to MoS2 and back to the porphyrin, operated. This study reveals the potential of transition‐metal dichalcogenides in photosensitization processes.
Fast Lithium Ion Conduction in Lithium Phosphidoaluminates
Authors: Restle Tassilo M. F. , Sedlmeier Christian , Kirchhain Holger , Klein Wilhelm , Raudaschl‐Sieber Gabriele , Deringer Volker L. , van Wüllen Leo , Gasteiger Hubert A. , Fässler Thomas F.
Published: December 2019

Solid electrolyte materials are crucial for the development of high‐energy‐density all‐solid‐state batteries (ASSB) using a nonflammable electrolyte. In order to retain a low lithium‐ion transfer resistance, fast lithium ion conducting solid electrolytes are required. We report on the novel superionic conductor Li9AlP4 which is easily synthesised from the elements via ball‐milling and subsequent annealing at moderate temperatures and which is characterized by single‐crystal and powder X‐ray diffraction. This representative of the novel compound class of lithium phosphidoaluminates has, as an undoped material, a remarkable fast ionic conductivity of 3 mS cm−1 and a low activation energy of 29 kJ mol−1 as determined by impedance spectroscopy. Temperature‐dependent 7Li NMR spectroscopy supports the fast lithium motion. In addition, Li9AlP4 combines a very high lithium content with a very low theoretical density of 1.703 g cm−3. The distribution of the Li atoms over the diverse crystallographic positions between the [AlP4]9− tetrahedra is analyzed by means of DFT calculations.
Oxidovanadium (IV) and iron (III) complexes with O2N2 donor linkage as plausible antidiabetic candidates: Synthesis, structural characterizations, glucose uptake and model biological media studies
Authors: Kongot Manasa , Reddy Dinesh S. , Singh Vishal , Patel Rajan , Singhal Nitin Kumar , Kumar Amit
Published: December 2019

With the upsurging cases of type II diabetic patients, the demand for safe and effective oral antidiabetic drugs is also increasing. Coordination complexes have proven their mettle as efficient oral drug candidates, which thereby motivated us in this work to design new transition metal complexes as plausible candidates for the treatment of diabetes. A reduced salen ligand, {H2(hpdbal)2‐an} (1) derived vanadium (IV) and iron (III) complexes, namely, [VIVO{(hpdbal)2‐an}] (2) and [{FeIII (OH2)((hpdbal)2‐an)}2 μ2‐SO4] (3) were synthesized in this study. The newly obtained ligand and complexes were characterized using usual analytical and spectroscopic techniques. The potential of these compounds in inducing increased glucose uptake by diabetic cells were studied by using insulin resistant HepG2 cells as model diabetic cells and 2‐NBDG molecule as a D‐glucose analogue and fluorescent tracker. The cells added with the vanadium (IV) complex 3 induced significant NBDG uptake of 95.4% which was higher than that induced by metformin, the standard antidiabetic drug. To elucidate the behavior of the complexes in biological media, model solution studies were conducted with a wide range of pH conditions and protein bovine serum albumin (BSA). The complexes demonstrated effective binding with BSA which was concluded through spectroscopic titration studies and were also found to be sufficiently stable over physiological pH conditions. The study can thus prove to be beneficial in the quest for new antidiabetic drugs.
Shape memory CTBN/epoxy resin/cyanate ester ternary resin and their carbon fiber reinforced composites
Authors: Li Zhihua , Hu Jiankang , Ma Li , Liu Hongxin
Published: December 2019

Carboxylated‐terminated liquid acrylonitrile rubber (CTBN) and epoxy resin (JEF‐0211) were coreacted with cyanate ester (CE) to form CTBN/EP/CE ternary resin systems. Further, the ternary resin system was applied as prepreg for carbon fiber composites with vacuum bag degassing molding process. CTBN/EP/CE ternary shape memory polymer (SMP) exhibited relatively high tensile strength, Young's modulus, impact strength, and excellent shape memory properties. Compared with CTBN/EP/CE ternary SMP, CTBN/EP/CE carbon fiber composites showed much higher mechanical properties, such as their tensile strength and Young's modulus were high to 570 MPa and 36.7 GPa, respectively. Furthermore, CTBN/EP/CE carbon fiber composites exhibited good shape memory properties, their shape fixity ratio and shape recovery ratio were more than 95% after 30 times repeating shape memory tests. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48756.
A comparison of teaching tacts with and without background stimuli on acquisition and generality
Authors: Mitteer Daniel R. , Luczynski Kevin C. , McKeown Ciobha A. , Cohrs Victoria L.
Published: December 2019

We evaluated whether teaching tacts of images with or without backgrounds would affect acquisition during teaching and generality across untaught targets with four children diagnosed with autism spectrum disorder. Including backgrounds could slow acquisition but bolster generality across other media containing backgrounds, whereas removing backgrounds may improve acquisition but result in poorer generality. Overall, acquisition rates were similar across conditions for three children, although one child displayed consistently slower acquisition during the background condition. We rarely observed generality to untaught targets when programming extinction, but embedding differential reinforcement or teaching additional images with backgrounds led to equally successful outcomes irrespective of initial teaching conditions. Teaching with or without backgrounds may result in marginal differences in acquisition of teaching and untaught targets, especially when arranging supplemental procedures during tests for generality. We discuss the importance of intrasubject replication, considerations when testing for generality, and implications for practice.
Mapping the interlinkages between sustainable development goal 9 and other sustainable development goals: A preliminary exploration
Authors: Mantlana Khanyisa B. , Maoela Malebajoa A.
Published: December 2019

The set of 17 Sustainable Development Goals (SDGs) and 169 targets aims to move the world to a sustainable trajectory of economic development, environmental sustainability, and social inclusion. This paper presents a review of relevant reports as well as scientific publications to assess the interlinkages between SDG 9 dealing with industrial innovation and infrastructure and SDGs relating to social inclusion (SDG 2 and 11), environmental sustainability (SDG 6, 13, and 15), and economic development (SDG 7). The identified interlinkages were mapped and characterized based on compatibility (co‐benefit, trade‐off, neutral) in attaining the targets of the considered SDGs. Our results showed that the co‐benefits were by far the most dominant interactions between the targets of SDG 9 and the targets of the SDGs that were considered. The targets of SDG 2 had the largest number of neutral interlinkages with the targets of SDG 9, while trade‐off interlinkages were found mainly between SDG 9 targets and the targets of SDG 6, 13, and 15. This review will raise awareness of the significance of understanding the nature of interlinkages between the different SDGs to relevant role players and will also inform and stimulate science–policy dialogue on the importance of interlinkages in the implementation, monitoring, and reporting of SDG 9 targets.
The role of psychopathic traits and moral disengagement in cyberbullying among adolescents
Authors: Hoareau Natacha , Bagès Céline , Allaire Mégane , Guerrien Alain
Published: December 2019

Background

The prevalence of cyberbullying suggests that about 15% of school‐aged children are involved in some way, although estimates vary widely. Preventing and limiting the behaviour will require more understanding of how mutable variables relate to it. There is some evidence linking higher psychopathy scores to cyberbullying, but the cognitive processes involved in ‘moral disengagement’ may provide better candidates for intervention.

Aims

To test the hypothesis that psychopathy scores and moral disengagement ratings would each be associated with cyberbullying, but that sex and age would moderate any associations.

Method

We conducted a cross‐sectional study with 334 11 to 15‐year‐olds (162 girls, 172 boys) from two French schools. Participants completed a self‐report questionnaire which measured cyberbullying, psychopathy traits and moral disengagement.

Results

We found a significant relationship between moral disengagement scale scores and cyberbullying ratings, but a stronger relationship between psychopathy scores and likelihood of cyberbullying. Neither sex nor age of the students affected these relationships.

Conclusion

This study adds to existing knowledge in showing that enduring personal qualities, as captured by a self‐rated psychopathy scale, may increase the risk of cyberbullying among adolescents. The findings suggest that teachers should be helped to monitor students’ emotional and cognitive social skills and consider extra support for those who struggle to recognise or process others’ distress.
Charcot arthropathy: The diagnostic dilemma of a painless, destructive joint
Authors: Galanis Nikiforos , Kyriakou Aikaterini , Delniotis Ioannis , Charanidi Paraskevi , Mavropoulos Paraskevas , Inklebarger James
Published: December 2019

The impressive clinical picture of Charcot joint reflects a high energy trauma injury which in the contrary is a progressive, painless arthropathy. Early and accurate diagnosis is crucial. A favorable outcome is elicited when joint is treated promptly, while late or misdiagnosis may lead to amputation.
Recent Developments in the Modelling of Heterogeneous Catalysts for CO2 Conversion to Chemicals
Authors: Podrojková Natalia , Sans Victor , Oriňak Andrej , Oriňaková Renata
Published: December 2019

Density functional theory (DFT) of the CO2 behavior on the catalyst surface provides valuable insights about the C=O bond activation, information about adsorption and dissociation of CO2, understanding the elementary steps involved in the mechanism of the CO2 hydrogenation reaction. Nowadays, DFT computational studies for the catalytic hydrogenation of CO2 are becoming very popular. Therefore, this article is focused on a comprehensive review of the DFT studies in thermocatalytic hydrogenation of CO2 at the gas‐surface interface and discusses three aspects: 1) processes taking place on the surfaces and facets of transition metal heterogeneous catalysts, 2) adsorption of CO2 on surfaces of different transition metals; 3) current understanding of reaction mechanisms taking place on the catalytic surface for the production of different compounds. A detailed schematic overview of the possible CO2 hydrogenation mechanisms and DFT simulations presented here will enhance the current understanding of the CO2 catalytic hydrogenation.
Implanting Copper−Zinc Nanoparticles into the Matrix of Mesoporous Alumina as a Highly Selective Bifunctional Catalyst for Direct Synthesis of Dimethyl Ether from Syngas
Authors: Sun Yingqi , Zhao Zhongkui
Published: December 2019

Dimethyl ether (DME) is an industrially important intermediate and clean alternative fuel. Thus, developing an efficient bifunctional catalyst for syngas‐to‐DME is practically important but remains a challenge. In this paper, a copper−zinc implanting into matrix of mesoporous alumina (CuZn@m−Al2O3) catalyst was prepared by introducing the as‐prepared Cu−Zn oxalate nanoparticles into the Al(i‐OPr)3‐containing precursor solution for preparing mesoporous Al2O3 (m‐Al2O3) through evaporation‐inducing assembly method. The preparation of Cu−Zn oxalate in advance for synthesizing CuZn@m−Al2O3 can intensify the Cu−ZnO interaction, confirmed by XRD and H2‐TPR. Thanks to the unique CuZn‐implanting closed structure, CuZn@m−Al2O3 shows 89.0 % of higher selectivity with comparable CO conversion (15.5 %) than the previously reported supported‐type CuZn catalyst on m‐Al2O3 (CuZn/m−Al2O3, 75.2 %) for hydrogenation of syngas to DME. Over the developed CuZn@m−Al2O3 catalyst, 0.16 mmol g−1 cat h−1 of high DME rate can be achieved. CuZn@m−Al2O3 also shows higher methanation resistance (2.7 % CH4) compared to CuZn/m−Al2O3 (6.3 %), ascribed to intensified Cu−Zn interaction owing to the as‐formation of Cu−Zn oxalate in advance. Moreover, Both CuZn@m−Al2O3 and CuZn/m−Al2O3 exhibit high stability. The outstanding catalytic performance of CuZn@m−Al2O3 allows it to be a promising catalyst for DME synthesis from syngas.
Surface Engineering for Advanced Aqueous Supercapacitors: A Review
Authors: Xu Cuixia , Yang Hui , Li Yi , Wang Jianwei , Lu Xihong
Published: December 2019

Abstract: Considerable attention has been focused on aqueous supercapacitors (SCs), owing to their large power density and excellent cycling stability, which makes them more suitable for high power applications. However, the lower energy densities (E) of aqueous SCs as compared to batteries have impeded their range of commercial applications. To overcome this challenge, intensive studies have been devoted to the topic, in which surface engineering becomes critical to the high‐performance electrode design due to the efficient manipulation of a material surface to boost energy storage while maintaining the integrity of interior of the material. The purpose of this Minireview article is to highlight recent significant breakthroughs realized through surface engineering approaches such as surface functionalization, heterostructure design, and surface charge modulation. Current challenges, emerging trends, and opportunities for advanced SCs are discussed accordingly.
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

Copper 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

Considerable 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

A 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

X‐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

An 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

The 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

Minimal 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

Lanthanide (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

Tropifexor (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

The 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

Halogen (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

Cassava 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 material

Support Protocol 2: Preparation of standard compound mixtures for absolute quantification of metabolites by GC‐MS

Support Protocol 3: Preparation of retention‐time standard mixture

Basic 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 procedure

Basic Protocol 3: Determination of soluble sugars, starch, and free amino acids

Alternate Protocol: Determination of soluble sugars and starch

Basic Protocol 4: Determination of anions

Basic Protocol 5: Determination of elements

Basic Protocol 6: Determination of total protein

Basic Protocol 7: Determination of non‐targeted and targeted secondary metabolites

Basic Protocol 8: Determination of carotenoids, chlorophylls, and tocopherol

Basic 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

The 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 activity

Support Protocol 1: Determination of dose dependence and isoform selectivity of RyR inhibitors using [Ca2+]ER assay

Basic Protocol 2: [3H]‐Ryanodine binding assay for RyR channel activity

Support 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

In 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

A 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.