bluuebunny/crossref_metadata_2025 huggingface dataset:
High‐Efficiency PbS Quantum‐Dot Solar Cells with Greatly Simplified Fabrication Processing via “Solvent‐Curing”
Authors: Lu Kunyuan , Wang Yongjie , Liu Zeke , Han Lu , Shi Guozheng , Fang Honghua , Chen Jun , Ye Xingchen , Chen Si , Yang Fan , Shulga Artem G. , Wu Tian , Gu Mengfan , Zhou Sijie , Fan Jian , Loi Maria Antonietta , Ma Wanli
Published: May 2018

PbS quantum‐dot (QD) solar cells are promising candidates for low‐cost solution‐processed photovoltaics. However, the device fabrication usually requires ten more times film deposition and rinsing steps, which is not ideal for scalable manufacturing. Here, a greatly simplified deposition processing is demonstrated by replacing methanol with acetonitrile (ACN) as the rinsing solvent. It is discovered that ACN can effectively “cure” the film cracks generated from the volume loss during the solid‐state ligand‐exchange process, which enables the deposition of thick and dense films with much fewer deposition steps. Meanwhile, due to the aprotic nature of ACN, fewer trap states can be introduced during the rinsing process. As a result, with only three deposition steps for the active layer, a CPVT‐certified 11.21% power conversion efficiency is obtained, which is the highest efficiency ever reported for PbS QD solar cells employing a solid‐state ligand‐exchange process. More importantly, the simple film‐deposition processing provides an opportunity for the future application of QDs in low‐cost printing of optoelectronic devices.
Magnetic Binary Silicide Nanostructures
Authors: Goldfarb Ilan , Cesura Federico , Dascalu Matan
Published: May 2018

In spite of numerous advantageous properties of silicides, magnetic properties are not among them. Here, the magnetic properties of epitaxial binary silicide nanostructures are discussed. The vast majority of binary transition‐metal silicides lack ferromagnetic order in their bulk‐size crystals. Silicides based on rare‐earth metals are usually weak ferromagnets or antiferromagnets, yet both groups tend to exhibit increased magnetic ordering in low‐dimensional nanostructures, in particular at low temperatures. The origin of this surprising phenomenon lies in undercoordinated atoms at the nanostructure extremities, such as 2D (surfaces/interfaces), 1D (edges), and 0D (corners) boundaries. Uncompensated superspins of edge atoms increase the nanostructure magnetic shape anisotropy to the extent where it prevails over its magnetocrystalline counterpart, thus providing a plausible route toward the design of a magnetic response from nanostructure arrays in Si‐based devices, such as bit‐patterned magnetic recording media and spin injectors.
Programmable Hydrogel Ionic Circuits for Biologically Matched Electronic Interfaces
Authors: Zhao Siwei , Tseng Peter , Grasman Jonathan , Wang Yu , Li Wenyi , Napier Bradley , Yavuz Burcin , Chen Ying , Howell Laurel , Rincon Javier , Omenetto Fiorenzo G. , Kaplan David L.
Published: May 2018

The increased need for wearable and implantable medical devices has driven the demand for electronics that interface with living systems. Current bioelectronic systems have not fully resolved mismatches between engineered circuits and biological systems, including the resulting pain and damage to biological tissues. Here, salt/poly(ethylene glycol) (PEG) aqueous two‐phase systems are utilized to generate programmable hydrogel ionic circuits. High‐conductivity salt‐solution patterns are stably encapsulated within PEG hydrogel matrices using salt/PEG phase separation, which route ionic current with high resolution and enable localized delivery of electrical stimulation. This strategy allows designer electronics that match biological systems, including transparency, stretchability, complete aqueous‐based connective interface, distribution of ionic electrical signals between engineered and biological systems, and avoidance of tissue damage from electrical stimulation. The potential of such systems is demonstrated by generating light‐emitting diode (LED)‐based displays, skin‐mounted electronics, and stimulators that deliver localized current to in vitro neuron cultures and muscles in vivo with reduced adverse effects. Such electronic platforms may form the basis of future biointegrated electronic systems.
A Voltage Bias Effect on Catalytic Activity of Electrically Continuous Pt/TiO2 Nanocomposites
Authors: Ray Nathan J. , Karpov Eduard G.
Published: May 2018

Recently, efforts to optimize catalytic performance have included the utilization of catalytic nanoparticles with careful control over their shape and size, chemical composition, surface functionalization, and structural architecture. Here, direct measurements are reported detailing the impact of applied external bias on the exothermic catalytic formation of water for a Pt/TiO2 nanocomposite under exposure to gaseous oxyhydrogen environments. As external voltages of opposite polarity are applied to the system, the surface temperature kinetics, total pressure kinetics within the analytical chamber, and water turnover frequency transition in a reproducible manner between two well‐defined states which result in 1) decreased catalytic activity, 2) decreased initial molecular adsorption onto the Pt catalyst, and 3) lower rates of water production under negative voltage. These findings pave the road toward the realization of a catalytic switch that can be activated by applying a voltage to Schottky barrier systems to enhance or mitigate catalytic surface reactions.
Graphene‐Like Nitrogen‐Doped Carbon Nanosheet Prepared from Direct Calcination of Dopamine Confined by g‐C3N4 for Oxygen Reduction
Authors: Liu Xinghuan , Kang Junjie , Dai Yu , Dong Changchang , Guo Xuhong , Jia Xin
Published: May 2018

2D carbon nanosheet provides an attractive prospect in the field of electrochemical catalysis, and how to prepare atomic level 2D carbon nanosheet with good electrochemical performance by an easy and efficient method is still a big challenge. Herein, graphene‐like N‐doped carbon nanosheet with the thickness of 0.6–2 nm is prepared by one‐step and solvent‐free method of pyrolyzing dopamine (DA) confined by graphitic carbon nitride (g‐C3N4). Pyrocondensation polymerization of DA within the interlayers of g‐C3N4 to form N‐doped benzene‐fused ring structures at high temperature is reported, and DA‐derived graphene‐like carbon nanosheet at 1000 °C exhibits an excellent oxygen reduction reaction activity in alkaline environment and pronounced catalytic activity in acidic medium. It can further improve the practical application of DA‐based carbon materials.
Graphene/Polyamide Laminates for Supercritical CO2 and H2S Barrier Applications: An Approach toward Permeation Shutdown
Authors: Raine Thomas P. , Istrate Oana M. , King Barnaby E. , Craster Bernadette , Kinloch Ian A. , Budd Peter M.
Published: May 2018

Graphene is potentially the perfect barrier material, being impermeable even to the smallest gas molecules, but in practice it is difficult to achieve defect‐free graphene layers at large scale. Here, exceptional barrier performance for laminates comprising graphene nanoplatelet (GNP) paper sandwiched between two discs of polyamide 11 (PA11) is demonstrated. Results are compared with sandwich structures incorporating melt‐processed GNP/PA11 composites, and with chemical vapor deposition (CVD) monolayer graphene transferred onto PA11. PA11 is of interest as a polymer commonly utilized within the oil and gas industry for antiwear and barrier layers in flexible risers. Permeation studies were undertaken for a feed mixture of carbon dioxide (CO2) with 1.48% hydrogen sulfide (H2S) at a temperature of 60 °C and pressures up to 400 bar, providing the first data for the performance of graphene as a barrier to a supercritical fluid. Whereas a GNP/PA11 composite and a CVD graphene monolayer have little effect on permeability, compared to a pure PA11 control sample, a GNP/PA11 laminate reduces CO2 permeability by more than an order of magnitude, and reduces H2S permeability to an undetectable level.
A Dip‐Decoating Process for Producing Transparent Bi‐Superhydrophobic and Wrinkled Water Surfaces
Authors: Li Xiaoguang , Wang Yiqi , Wang Renxian , Wang Senhao , Zang Duyang , Geng Xingguo
Published: May 2018

As mechanical strength is required in most applications using superhydrophobic surfaces, much effort has been applied toward enhancing this property. However, mechanical weakness can also be useful, but little attention has been focused on this seemingly undesirable feature. Here, using a sol–gel SiO2 coating as a weak surface, a dip‐decoating phenomenon is demonstrated to occur when immersing and withdrawing the coating from water. As a result, part of the coating's outer layer of nanoparticles (NPs) is peeled off by shearing motions of the three‐phase line, generating a bi‐superhydrophobic surface constructed by adjacent pristine and dipped areas, with different colors, adhesive forces, and compositional stabilities. Such a Janus surface, which also features ultrahigh transmittance due to antireflection, can be used as a peculiar multifunctional platform for droplet manipulations. The dip‐decoating technique also works as a distinctive way for introducing particles onto water surface, in which the density and distribution of peeled NPs can be adjusted by multi‐dipping processes. The wrinkled water surface, caused by high NP density, can be used with the Langmuir–Blodgett coating technique and have potential in fundamental studies, such as the evaporation of coated liquids.
Ionic Liquids and Organic Ionic Plastic Crystals: Advanced Electrolytes for Safer High Performance Sodium Energy Storage Technologies
Authors: Basile Andrew , Hilder Matthias , Makhlooghiazad Faezeh , Pozo‐Gonzalo Cristina , MacFarlane Douglas R. , Howlett Patrick C. , Forsyth Maria
Published: May 2018

Electrolytes composed entirely of salts, namely, ionic liquid solvents paired with a target ion salt, have been studied extensively within lithium batteries and have recently garnered interest as advanced electrolytes for sodium chemistries. In this review, the unique properties of ionic liquid electrolytes and their solid‐state analogs, organic ionic plastic crystals, are examined. Structure–property relationships, the effect of salt addition, cation and anion functionalization, and their effect upon physicochemical and thermal character are discussed. The authors discuss the use of ionic liquid electrolytes paired with organic solvents (referred to as hybrids) and briefly present the impact of using water as an additive. The majority of the literature presented herein covers studies of sodium electrolytes at Na+ concentrations greater than 50 mol%, labelled as superconcentrated electrolytes, which have recently been investigated for their beneficial device performance and improved target ion mobility. The developing research of ionic liquids toward the oxygen reduction reaction is also presented toward the realization of Na–O2 chemistries to rival that of conventional Li‐ion; gaining fundamental understanding of the active species during discharge, its resultant nucleation and character. Additionally, the properties of the electrode–electrolyte interface resulting from the interaction between typical sodium anodes with ionic liquid electrolytes are discussed.
Photoelectrocatalytic Materials for Solar Water Splitting
Authors: Yao Tingting , An Xiurui , Han Hongxian , Chen John Qianjun , Li Can
Published: May 2018

Photoelectrocatalytic water splitting offers a promising approach to convert sunlight into sustainable hydrogen energy. A thorough understanding of the relationships between the properties and functions of photoelectrocatalytic materials plays a crucial role in the design and fabrication of efficient photoelectrochemical systems for water splitting. This review presents the advances in the development of efficient photoelectrocatalytic materials. First, the fundamentals involved in the photoelectrocatalytic water splitting are elaborated. Then, the critical properties of photoelectrocatalytic materials are classified and discussed according to the associated photoelectrochemical processes, including light absorption, charge separation, charge transportation, and photoelectrocatalytic reactions. The importance of heterointerfaces in photoelectrodes is also mentioned in conjunction with the illustration of some functional interlayer materials. Finally, some strategies that can be employed in material screening and optimization for the construction of highly efficient photoelectrochemical devices for water splitting are also discussed.
Are olfactory traits in a pair‐bonded primate under sexual selection? An evaluation of sexual dimorphism in Aotus nancymaae
Authors: Spence‐Aizenberg Andrea , Williams Lawrence E. , Fernandez‐Duque Eduardo
Published: May 2018

Objectives

Sexual selection has seemingly influenced chemical communication in numerous non‐human primates, although it is unclear whether it has influenced strictly pair‐living and pair‐bonded taxa. The physical similarities between male and female owl monkeys suggest that disruptive selection has not played a role in this taxon. However, given their nocturnality, olfactory traits may show differing patterns of sexual selection than visual traits. If sexual selection has influenced chemical communication in owl monkeys, we expect larger scent glands and greater scent‐marking in females given the high degree of paternal care, as has been proposed for callitrichines.

Materials and Methods

We evaluated sex differences in the qualitative and quantitative descriptions of the subcaudal and perianal glandular regions of captive male (n = 39) and female (n = 36) owl monkeys (A. nancymaae), and in the olfactory behaviors performed within breeding pairs (n = 16).

Results

Males had larger areas of secretion retained in the hairs covering the subcaudal gland, and females had more and darker secretion than males covering the perianal region. Males inspected the genital region of their partners more frequently than females did, but the sexes did not differ much in other investigative and marking behaviors.

Discussion

The observed sex differences and variation in olfactory traits are consistent with the hypothesis that sexual selection has influenced chemical communication in owl monkeys, with males having larger subcaudal glands and spending more time investigating odors. Still, sex differences in monogamous owl monkeys were less extreme than those in other, non‐monogamous, taxa.
Glucocorticoid receptor isoform expression in peripheral blood mononuclear leukocytes of patients with chronic rhinosinusitis
Authors: Taylor Robert J. , Schlosser Rodney J. , Soler Zachary M. , Mattos Jose L. , Mulligan Jennifer K.
Published: May 2018

Background

In several inflammatory disorders, altered peripheral blood mononuclear leukocyte (PBML) glucocorticoid (GC) receptor isoform expression has been associated with GC resistance and disease severity. However, it is unclear if PBML GC receptor isoforms are expressed differentially and are associated with worsened disease severity in chronic rhinosinusitis (CRS).

Methods

PBMLs were isolated from control (n = 8), CRS without nasal polyps (CRSsNP) (n = 8), atopic CRS with nasal polyps (CRSwNP) (n = 8), non‐atopic CRSwNP (n = 8), and allergic fungal rhinosinusitis (AFRS) (n = 8) patients. Demographics, atopic status, asthmatic status, 22‐item Sino‐Nasal Outcome Test (SNOT‐22) scores, Lund‐Kennedy nasal endoscopy scores, Lund‐Mackay sinus computed tomography (CT) scores, Kennedy Osteitis scores, and GC utilization 6 months postoperatively were collected. Intracellular immunostaining was then performed for functional GC receptor α (GCRα) and nonfunctional GC receptor β (GCRβ), followed by flow cytometry analysis of geometric mean fluorescent intensity (MFI) and the percentage of cells expressing each GC receptor isoform.

Results

Compared to controls, each CRS subtype had decreased PBML GCRα and GCRα:GCRβ MFI expression, but no difference in GCRβ expression. Decreasing PBML GCRα in AFRS was associated with increasing Lund‐Mackay sinus CT scores (r = −0.880, p =0.004). No significant associations were found between GC receptor isoform expression and other clinical measures.

Conclusion

CRS patients have reduced functional PBML GCRα expression and decreased GCRα:GCRβ compared to controls. Reductions in GCRα in AFRS are associated with worsening Lund‐Mackay sinus CT scores. The clinical implications of decreased functional GC receptor expression merits further investigation.
Activation of the rat olfactory bulb by direct ventral stimulation after nerve transection
Authors: Coelho Daniel H. , Socolovsky Leandro D. , Costanzo Richard M.
Published: May 2018

Background

The aim of this study was to demonstrate how direct electrical stimulation can activate the olfactory bulb after denervation of the olfactory nerve input.

Methods

Sprague‐Dawley rats (n = 5) were anesthetized and olfactory bulbs exposed. Olfactory nerves were transected by passing a Teflon blade between the cribriform plate and ventral surface of the bulb. A cochlear implant electrode array was used to stimulate 6 different positions along the ventral surface of the olfactory bulb. Biphasic constant‐current pulses were used (50‐1000 μA, 50–1000 μs) to stimulate the bulb, and a 16‐electrode paddle array was used to record localized negative field potential responses at the dorsal surface of the bulb.

Results

Localized negative field potentials were reliably obtained using biphasic, 500‐μA, 200‐μs pulses. A shift in stimulating position by 1 mm resulted in a significant change in the dorsal field potential.

Conclusion

Direct stimulation of the deafferented olfactory bulb was effective in generating localized field potential responses. These findings support the potential use of direct electrical stimulation for the treatment of anosmia.
Establishing the minimal clinically important difference for the Questionnaire of Olfactory Disorders
Authors: Mattos Jose L. , Schlosser Rodney J. , Mace Jess C. , Smith Timothy L. , Soler Zachary M.
Published: May 2018

Background

Olfactory‐specific quality of life (QOL) can be measured using the Questionnaire of Olfactory Disorders Negative Statements (QOD‐NS). Changes in the QOD‐NS after treatment can be difficult to interpret since there is no standardized definition of clinically meaningful improvement.

Methods

Patients with chronic rhinosinusitis (CRS) completed the QOD‐NS. Four distribution‐based methods were used to calculate the minimal clinically important difference (MCID): (1) one‐half standard deviation (SD); (2) standard error of the mean (SEM); (3) Cohen's effect size (d) of the smallest unit of change; and (4) minimal detectable change (MDC). We also averaged all 4 of the scores together. Finally, the likelihood of achieving a MCID after sinus surgery using these methods, as well as average QOD‐NS scores, was stratified by normal vs abnormal baseline QOD‐NS scores.

Results

Outcomes were examined on 128 patients. The mean ± SD improvement in QOD‐NS score after surgery was 4.3 ± 11.0 for the entire cohort and 9.6 ± 12.9 for those with abnormal baseline scores (p < 0.001). The MCID values using the different techniques were: (1) SD = 6.5; (2) SEM = 3.1; (3) d = 2.6; and (4) MDC = 8.6. The MCID score was 5.2 on average. For the total cohort analysis, the likelihood of reporting a MCID ranged from 26% to 51%, and 49% to 70% for patients reporting preoperative abnormal olfaction.

Conclusion

Distribution‐based MCID values of the QOD‐NS range between 2.6 and 8.6 points, with an average of 5.2. When stratified by preoperative QOD‐NS scores the majority of patients reporting abnormal preoperative QOD‐NS scores achieved a MCID.
Nanoskalige chemische Bildgebung von Zeolithen durch Atomsondentomographie
Authors: Schmidt Joel E. , Peng Linqing , Poplawsky Jonathan D. , Weckhuysen Bert M.
Published: May 2018

Struktur‐Zusammensetzungs‐Eigenschafts‐Beziehungen für zeolithbasierte Materialien sind entscheidend, um verbesserte Feststoffkatalysatoren zu entwickeln. Die Realisierung kann sich jedoch als schwierig erweisen, da sogar einzelne Zeolithkristalle Heterogenitäten aufweisen können, die sich auf Reaktivität, Diffusion und Stabilität auswirken können. Mithilfe von tomographischen Verfahren wurden Fortschritte bei der Charakterisierung dieser porösen Feststoffe erreicht, allerdings haben alle Methoden eine begrenzte räumliche Auflösung. Nur die Atomsondentomographie (APT) ist bisher in der Lage, 3D‐Rekonstruktionen mit Subnanometer‐Auflösung zu erzeugen. Hier behandeln wir die Untersuchung von Zeolithen mit APT: Hierzu gehören Aspekte der Probenvorbereitung, die Datenerfassung, die Signalzuordnung in Massenspektren, die kristallographische Auflösungsgrenze und eine genaue Datenanalyse. Sämtliche Abschnitte werden mit Beispielen erläutert. Zudem sollen bisher unveröffentlichte Daten und Analysen praktische Strategien aufzeigen, die mögliche Probleme des Einsatzes der APT bei Zeolithen lösen.
The Energetics of Surfactant‐Templating of Zeolites
Authors: Linares Noemi , Jardim Erika O. , Sachse Alexander , Serrano Elena , García‐Martínez Javier
Published: May 2018

Mesoporosity can be conveniently introduced into zeolites by treating them in basic surfactant solutions. The apparent activation energy involved in the formation of mesopores in USY by surfactant‐templating was determined using a combination of in situ synchrotron X‐ray diffraction and ex situ gas adsorption. Additionally, techniques such as pH measurement and thermogravimetry/differential thermal analysis were employed to determine OH− evolution and cetyltrimethylammonium ion (CTA+) uptake during the development of mesoporosity, thereby providing information about the different steps involved. The combination of both in situ and ex situ techniques has allowed determination of the apparent activation energies of the different processes involved in the mesostructuring of USY zeolites for the first time. Apparent activation energies are of the same order of magnitude (30–65 kJ mol−1) as those involved in the crystallization of zeolites. Hence, important mechanistic insight into the surfactant‐templating method was obtained.
An Inherently Chiral Au24 Framework with Double‐Helical Hexagold Strands
Authors: Sugiuchi Mizuho , Shichibu Yukatsu , Konishi Katsuaki
Published: May 2018

2,3‐bis(diphenylphosphino)butane enantiomers (chiraphos, L) used as chiral auxiliaries results in the preferential formation of an unprecedented Au24 framework with inherent chirality. The crystal structure of [Au24L6Cl4]2+ (1) has a square antiprism‐like octagold core twinned by two helicene‐like hexagold motifs, where the inherent chirality is associated with the helical arrangement. The clusters carrying (R,R)‐ and (S,S)‐ diphosphines had right‐ and left‐handed strands, respectively. Circular dichroism spectra showed peaks in the visible to near‐IR region, some of which did not coincide with absorption bands, suggesting the enantiomeric Au24 frameworks possess unique chiroptical properties. The Au24 frameworks were thermally robust, which could be attributed to the superatomic concept (18 e− system) and the steric constraint effects of the bridging ligand units.
MOF‐Derived Hollow CoS Decorated with CeOx Nanoparticles for Boosting Oxygen Evolution Reaction Electrocatalysis
Authors: Xu Huajie , Cao Jing , Shan Changfu , Wang Bingkai , Xi Pinxian , Liu Weisheng , Tang Yu
Published: May 2018

Transition‐metal sulfides (TMSs) have emerged as important candidates for oxygen evolution reaction (OER) electrocatalysts. Now a hybrid nanostructure has been decorated with CeOx nanoparticles on the surface of ZIF‐67‐derived hollow CoS through in situ generation. Proper control of the amount of CeOx on the surface of CoS can achieve precise tuning of Co2+/Co3+ ratio, especially for the induced defects, further boosting the OER activity. Meanwhile, the formation of protective CeOx thin layer effectively inhibits the corrosion by losing cobalt ion species from the active surface into the solution. It is thus a rare example of a hybrid hetero‐structural electrocatalyst with CeOx NPs to improve the performance of the hollow TMS nanocage.
Controlled Expansion of a Strong‐Field Iron Nitride Cluster: Multi‐Site Ligand Substitution as a Strategy for Activating Interstitial Nitride Nucleophilicity
Authors: Drance Myles J. , Mokhtarzadeh Charles C. , Melaimi Mohand , Agnew Douglas W. , Moore Curtis E. , Rheingold Arnold L. , Figueroa Joshua S.
Published: May 2018

Multimetallic clusters have long been investigated as molecular surrogates for reactive sites on metal surfaces. In the case of the μ4‐nitrido cluster [Fe4(μ4‐N)(CO)12]−, this analogy is limited owing to the electron‐withdrawing effect of carbonyl ligands on the iron nitride core. Described here is the synthesis and reactivity of [Fe4(μ4‐N)(CO)8(CNArMes2)4]−, an electron‐rich analogue of [Fe4(μ4‐N)(CO)12]−, where the interstitial nitride displays significant nucleophilicity. This characteristic enables rational expansion with main‐group and transition‐metal centers to yield unsaturated sites. The resulting clusters display surface‐like reactivity through coordination‐sphere‐dependent atom rearrangement and metal–metal cooperativity.
Controlling the Self‐Metalation Rate of Tetraphenylporphyrins on Cu(111) via Cyano Functionalization
Authors: Lepper Michael , Köbl Julia , Zhang Liang , Meusel Manuel , Hölzel Helen , Lungerich Dominik , Jux Norbert , de Siervo Abner , Meyer Bernd , Steinrück Hans‐Peter , Marbach Hubertus
Published: May 2018

The reaction rate of the self‐metalation of free‐base tetraphenylporphyrins (TPPs) on Cu(111) increases with the number of cyano groups (n=0, 1, 2, 4) attached at the para positions of the phenyl rings. The findings are based on isothermal scanning tunneling microscopy (STM) measurements. At room temperature, all investigated free‐base TPP derivatives adsorb as individual molecules and are aligned with respect to densely packed Cu substrate rows. Annealing at 400 K leads to the formation of linear dimers and/or multimers via CN‐Cu‐CN bonds, accompanied by self‐metalation of the free‐base porphyrins following a first‐order rate equation. When comparing the non‐cyano‐functionalized and the tetracyano‐functionalized molecules, we find a decrease of the reaction rate by a factor of more than 20, corresponding to an increase of the activation energy from 1.48 to 1.59 eV. Density functional theory (DFT) calculations give insights into the influence of the peripheral electron‐withdrawing cyano groups and explain the experimentally observed effects.
Preparation of poly (N,N‐dimethylaminoethyl methacrylate) (PDAEM) membranes: Application for water purification
Authors: Abdellaoui Naima , Laoui Fouad Mouloud , Cerbah Hamza , Arous Omar
Published: May 2018

The present work concerns a development of new membranes for performing ions separation. These membranes were prepared by solution casting followed by solvent evaporation, using a commercial cellulose triacetate (CTA), synthesized poly (N,N‐dimethylaminoethyl methacrylate), macrocylic polyethers (15‐crown‐5 and Dibenzo‐24‐crown‐8) as carrier and dioctylphtalate as plasticizer. Different Polymer Inclusion Membranes were characterized using physical and chemical techniques as well as Fourier transform infrared, thermogravimetric analysis, and scanning electron microscopy. Transport of lead and cadmium in aqueous solution has been studied using these systems. The selective separation of these membranes is accomplished by the presence of specific compounds, called carriers, in the membrane phase. The carriers are responsible to facilitate the transport of the target component across selective membranes. The influence of the membrane nature has been studied using some supports of different physical characteristics. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46592.
Copper/Diboron‐Mediated Intramolecular Oxygenation and Allylation/Benzylation of Nitroalkynes for the Synthesis of C2‐Quaternary Indolin‐3‐ones
Authors: Fu Wenqiang , Zhou Yao , Song Qiuling
Published: May 2018

A direct strategy for intramolecular transfer oxygenation of alkynes and cycloisomerization of 2‐nitroalkynes to synthesize a wide range of C2‐quaternary indolin‐3‐ones was developed by a copper/diboron system. The desired allylation, benzylation and propargylation products were obtained in moderate to excellent yields with good functional group tolerance. The mechanism study indicated that this protocol involved a radical process.
The development of the production cost of oxymethylene ethers as diesel additives from biomass
Authors: Oyedun Adetoyese O , Kumar Amit , Oestreich Dorian , Arnold Ulrich , Sauer Jörg
Published: May 2018

Oxymethylene ethers (OMEs) are important diesel additives because of their ability to reduce soot loading, particulate matter (PM) emissions, and NOx emissions. Some research has been undertaken on the feasibility of producing OMEs from biomass but there is no techno‐economic assessment of OME production from biomass. In this study, we estimate the unit cost to produce OMEn (n = 1–8) from three different biomass types common to western Canada: whole‐tree woodchips, forest residues, and wheat straw. The techno‐economic model uses the OME production simulation results for 500 MT day−1 of dry biomass. The simulation results show that 97.70, 98.86, and 99.80 MT day−1 of OME1–8 can be produced from whole‐tree woodchips, forest residues, and wheat straw, respectively. The costs of producing OME per liter over 20 years of production are $1.93 ±0.15/L, $1.68 ±0.14/L, and $1.66 ±0.13/L, respectively, at a 95% confidence level for whole‐tree woodchips, forest residues, and wheat straw biomass. The sensitivity analysis results show that the internal rate of return, OME yield, capital cost, and biomass delivery cost significantly influence OME unit price. The production price versus capacity profile reveals that the optimum minimum price can be obtained at a plant capacity of 4000 MT day−1 of biomass; beyond this, the increase in capacity does not result in any appreciable decrease in production price. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.
Large for gestational age and macrosomia in singletons born after frozen/thawed embryo transfer (FET) in assisted reproductive technology (ART)
Authors: Berntsen Sine , Pinborg Anja
Published: May 2018

Increase in success rates with frozen embryo transfer (FET) and reduced risk of ovarian hyperstimulation syndrome (OHSS) and multiple pregnancies has lead to a steady rise in FET. Further, FET is associated with lower risk of prematurity and low birth weight in singletons, when compared with fresh transfer. However, there is a growing concern of increased risk of large for gestational (LGA) and/or macrosomic children after FET. Macrosomic/LGA births have a higher risk of cesarean section, fetal hypoxia and stillbirth. Improvements in cryopreservation techniques indicate that FET is a trend expected to continue and a freeze‐all policy has lately been introduced. With this review, we wished to evaluate the association between FET and LGA and/or macrosomia. We searched electronic databases on January 12, 2018. Ten studies on LGA and six studies on macrosomia were eligible for meta‐analysis. We found that the risk of LGA in FET was increased 1.5‐fold (AOR = 1.50 95% CI 1.44–1.57 p < 0.001) compared to fresh cycles and 1.3‐fold (AOR = 1.31 95% CI 1.20–1.43 p < 0.001) compared to natural conception (NC). Similarly we found a 1.7‐fold increased risk of macrosomia in FET compared to fresh transfer (AOR = 1.71 95% CI 1.59–1.83 p < 0.001) and a 1.4‐fold increased risk compared to NC (AOR = 1.42 95% CI 1.17–1.71 p < 0.001). Whether the increased risk of LGA and macrosomia is associated with higher long‐term health risks remains unknown. Future studies should explore epigenetics modifications in children born after FET and predictors of long‐term diseases need to be examined further with longitudinal studies.
The impact of contemporary preimplantation genetic screening and diagnosis on the detection of aneuploidy and inherited genetic diseases
Authors: Neal Shelby A. , Werner Marie D.
Published: May 2018

Pre‐implantation genetic screening and diagnosis represent important tools for embryo selection in patients undergoing in vitro fertilization. Methods have evolved in recent years and it can be challenging to remain up to date on the current technology. This review article seeks to provide an overview of pre‐implantation genetic screening and diagnosis methods, the associated clinical outcomes, and the limitations of this technology.
A survey on modeling and simulation practices for teaching power harmonics
Authors: Igual Raúl , Plaza Inmaculada , Marcuello Juan José , Arcega Francisco
Published: May 2018

In recent years the undergraduate engineering curriculum of several areas has started to incorporate the study of harmonic distortion on electrical systems. Several education simulation tools have been developed and investigated, most of them a short time ago. However, to the best of our knowledge, there is not any literature review on this topic. In this work, we present for the first time a systematic survey on educational tools to model and simulate the effect of power harmonics on industrial electrical networks. As a result, several improvement aspects have been identified and recommendations and implications for future research have been provided. For that, a retrospective study has been accomplished, showing a growing trend toward simulation and modeling. The key instructors’ perceptions to incorporate these practices are the ease of the teaching‐learning process and the importance of modeling and simulation in the industry. The main research challenge is the conduction of integral assessments that comprise both tools’ quality and use experience, and their contribution to achieve learning outcomes. Statistical tests should be used to validate the academic results obtained. This is a major challenge, since only a few of the existing studies incorporate such tests. Other implications for future research refer to the involvement of a higher number of students in the evaluations and the use of free software in the development of the applications.
Modeling real world software engineering using cryptography
Authors: Çulha Davut
Published: May 2018

In software engineering, real world projects are very important for software engineering students. Real world projects help software engineering students to be prepared for real world development. However, directly involving in real world projects is difficult and its benefits are questionable. Therefore, simulation of real world projects can be a solution for this situation. In this paper, the power of cryptography is used to simulate real world projects. Simulation of a project is designed and applied, and its results are discussed.
Emotional virtual crowd on task completion in virtual markets
Authors: Huang Po‐Han , Wong Sai‐Keung
Published: May 2018

This paper studies the effects of a virtual crowd with emotion on task completion in a virtual market. The users have to interact with the virtual agents so that the virtual agents are willing to lead the users to specific vendors. Then, the users can buy the required items. The users communicate with the virtual agents via a conversation dialog. The emotional agents' moods are affected by their own interaction (e.g., collision) while they are walking. Furthermore, their moods are also affected by the conversational responses of the users. We adopt a simple 2D mood model and use icons to represent the mood states of the agents. The mood model supports four mood states, which are “Excitement”, “Anger”, “Sadness”, and “Neutral”. We conducted a user study to evaluate the effects of the emotional virtual agents in different aspects, including task completion, time spent in conversation, following distance, and realism of the emotional virtual crowd.
Transporting objects by multiagent cooperation in crowd simulation
Authors: Chen Hsuan , Wong Sai‐Keung
Published: May 2018

This paper focuses on simulating agents transporting passive objects in a virtual environment with pedestrians. The agents adopt the pushing manipulation patterns to transport the passive objects. We propose techniques to achieve two kinds of cooperation. First, the agents transport the passive objects to the goal positions. During the transportation process, the agents may adjust their formation to transport the passive objects effectively. Second, the agents avoid collision with each other and passive objects in an unfreezing manner. Experiment results show that our technique avoids the freezing problem while the agents are transporting multiple objects.
A novel refocusing distance measurement method using super‐resolved light field images
Authors: Zhao Mandan , Hao Xiangyang
Published: May 2018

This paper proposes a novel distance measurement method using superresolved light‐field images. We first superresolve the light field using the hybrid cross‐resolution input based on PatchMatch and convolutional neural network method, which combines and takes advantage of these two methods. In this way, we can explore the similarity between images and deal with challenging scenes effectively. The scaling factor is up to eight times, which is much larger than the ordinary superresolution scaling factor, and our superresolution method can also maintain a satisfactory accuracy. With the traditional idea of focus ranging, the light‐field 3D measurement method is established. A proper definition evaluation function suitable for light‐field data is selected to evaluate the imaging quality, and the triangle barycenter interpolation method is proposed to measure 3D scenes. Experimental results demonstrate that the proposed method not only improves the quality of the reconstructed high‐resolution light field but also has the ability of the distance measurement. It indicates that the light‐field imaging is a promising 3D measurement technique.
Empowerment and embodiment for collaborative mixed reality systems
Authors: Pan Ye , Sinclair David , Mitchell Kenny
Published: May 2018

We present several mixed‐reality‐based remote collaboration settings by using consumer head‐mounted displays. We investigated how two people are able to work together in these settings. We found that the person in the AR system will be regarded as the “leader” (i.e., they provide a greater contribution to the collaboration), whereas no similar “leader” emerges in augmented reality (AR)‐to‐AR and AR‐to‐VRBody settings. We also found that these special patterns of leadership only emerged for 3D interactions and not for 2D interactions. Results about the participants' experience of leadership, collaboration, embodiment, presence, and copresence shed further light on these findings.
Preparation of Cyclic Prodiginines by Mutasynthesis in Pseudomonas putida KT2440
Authors: Klein Andreas Sebastian , Brass Hannah Ursula Clara , Klebl David Paul , Classen Thomas , Loeschcke Anita , Drepper Thomas , Sievers Sonja , Jaeger Karl‐Erich , Pietruszka Jörg
Published: May 2018

Prodiginines are a group of naturally occurring pyrrole alkaloids produced by various microorganisms and known for their broad biological activities. The production of nature‐inspired cyclic prodiginines was enabled by combining organic synthesis with a mutasynthesis approach based on the GRAS (generally recognized as safe) certified host strain Pseudomonas putida KT2440. The newly prepared prodiginines exerted antimicrobial effects against relevant alternative biotechnological microbial hosts whereas P. putida itself exhibited remarkable tolerance against all tested prodiginines, thus corroborating the bacterium's exceptional suitability as a mutasynthesis host for the production of these cytotoxic secondary metabolites. Moreover, the produced cyclic prodiginines proved to be autophagy modulators in human breast cancer cells. One promising cyclic prodiginine derivative stood out, being twice as potent as prodigiosin, the most prominent member of the prodiginine family, and its synthetic derivative obatoclax mesylate.
Regulation of inward rectifier potassium current ionic channel remodeling by AT1‐Calcineurin‐NFAT signaling pathway in stretch‐induced hypertrophic atrial myocytes
Authors: He Jionghong , Xu Yanan , Yang Long , Xia Guiling , Deng Na , Yang Yongyao , Tian Ye , Fu Zenan , Huang Yongqi
Published: May 2018

Previous studies have shown that the activation of angiotensin II receptor type I (AT1) is attributed to cardiac remodeling stimulated by increased heart load, and that it is followed by the activation of the calcineurin‐nuclear factor of activated T‐cells (NFAT) signaling pathway. Additionally, AT1 has been found to be a regulator of cardiocyte ionic channel remodeling, and calcineurin‐NFAT signals participate in the regulation of cardiocyte ionic channel expression. A hypothesis therefore follows that stretch stimulation may regulate cardiocyte ionic channel remodeling by activating the AT1‐calcineurin‐NFAT pathway. Here, we investigated the role of the AT1‐calcineurin‐NFAT pathway in the remodeling of inward rectifier potassium (Ik1) channel, in addition to its role in changing action potential, in stretch‐induced hypertrophic atrial myocytes of neonatal rats. Our results showed that increased stretch significantly led to atrial myocytes hypertrophy; it also increased the activity of calcineurin enzymatic activity, which was subsequently attenuated by telmisartan or cyclosporine‐A. The level of NFAT3 protein in nuclear extracts, the mRNA and protein expression of Kir2.1 in whole cell extracts, and the density of Ik1 were noticeably increased in stretched samples. Stretch stimulation significantly shortened the action potential duration (APD) of repolarization at the 50% and 90% level. Telmisartan, cyclosporine‐A, and 11R‐VIVIT attenuated stretch‐induced alterations in the levels of NFAT3, mRNA and protein expression of Kir2.1, the density of Ik1, and the APD. Our findings suggest that the AT1‐calcineurin‐NFAT signaling pathway played an important role in regulating Ik1 channel remodeling and APD change in stretch‐induced hypertrophic atrial myocytes of neonatal rats.
Peraryl Arsoles: Practical Synthesis, Electronic Structures, and Solid‐State Emission Behaviors
Authors: Imoto Hiroaki , Urushizaki Aya , Kawashima Ikuo , Naka Kensuke
Published: May 2018

2,3,4,5‐Tetraaryl‐1‐phenylarsoles were synthesized by utilizing safely generated diiodophenylarsine and zirconacyclopentadienes. The obtained peraryl arsoles showed aggregation‐induced emission (AIE), where intense emission was observed in the solid states (quantum yields up to 0.61), whereas the corresponding solutions were very weakly emissive. The optical and electronic properties were examined by experimental and computational methods. It was elucidated that the aryl groups at the 2,5‐positions affected the frontier orbitals and the aromaticity of the arsole core. On the other hand, those at the 1,3,5‐positions were perpendicular to the luminophore and effective for a restriction of aggregation‐caused quenching. Because the lone pair of the arsenic atom has a sufficient coordination ability due to the low aromaticity of the arsole moiety, a gold(I) chloride complex of 1,2,3,4,5‐pentaphenylarsole was synthesized. The complex formation caused a blue shift of the emission from the bare ligand. Interestingly, the complex showed luminescent mechanochromism; grinding the crystals with a blue emission (λem=445 nm) gave amorphous samples with a greenish–blue emission (λem=496 nm).
B‐Heterocyclic Carbene Arising from Charge Shift: A Computational Verification
Authors: Zhang Congjie , Fan Fan , Wang Zhimin , Song Jinshuai , Li Chunsen , Mo Yirong
Published: May 2018

1‐Borabicyclo[1.1.0]but‐2(3)‐ene (1BB) is a singlet biradical with two single electrons that can form an ionic resonance structure through a charge shift. The ionic resonance structure is a B‐heterocyclic carbene (BHC), which can act as a carbene, Lewis base, or L‐ and Z‐type ligand, to give adducts and complexes. Through a range of quantum methods, four types of stable compounds (A–D) derived from 1BB have been designed. These compounds retain the unique features of 1BB. As a consequence, the structures, stability, and Wiberg bond indices of the Lewis adducts of A–D with Lewis acids (BePh2, BH3, AlH3, AlCl3, C5BH5, and C13BH9) and CuI, AgI, and AuI complexes have been investigated. Results show that A–D can indeed react as carbenes. Interestingly, compounds A–D, as L‐type ligands, can attach to BePh2, BH3, AlH3, AlCl3, C5BH5, C13BH9, and CuCl and form compounds with planar tetracoordinate carbon (ptC), whereas Z‐type ligands A–D can bind to AgCl and AuCl to provide complexes with planar tetracoordinate boron (ptB). In addition, the binuclear complexes of ClX(1BB)CuCl (X=Ag, Au) have been studied and A–D behave as both L‐ and Z‐type ligands, in which these complexes contain both ptC and ptB. Thus, a novel method for designing compounds with ptC and ptB is presented. These rationally designed compounds involve the elements of carbene, ptC, ptB, and L‐ and Z‐type ligands, and are expected to be unique and useful in experimental chemistry once they are synthesized.
Online learning with sparse labels
Authors: He Wenwu , Zou Fumin , Liang Quan
Published: May 2018

In this paper, we consider an online learning scenario where the instances arrive sequentially with partly revealed labels. We assume that the labels of instances are revealed randomly according to some distribution, eg, Bernoulli distribution. Three specific algorithms based on different inspirations are developed. The first one performs the idea of Estimated gradient for which a strict high‐probability regret guarantee in scale of
can be derived, when the distributing parameter p is revealed. An empirical version is also developed for cases where the learner has to learn the parameter p when it is not revealed. Experiments on several benchmark data sets show the feasibility of the proposed method. To further improve the performance, two kinds of aggressive algorithms are presented. The first one is based on the idea of instances recalling, which tries to get the full use of the labeled instances. The second one is based on the idea of labels learning, and it tries to learn the labels for unlabeled instances. In particular, it includes the step of online co‐learning, which aims to learn the labels, and the step of weighted voting, which aims to make the final decision. Empirical results confirm the positive effects of the two aggressive algorithms.