bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetic Sponge with Neutral–Ionic Phase Transitions
Authors: Kosaka Wataru , Takahashi Yusuke , Nishio Masaki , Narushima Keisuke , Fukunaga Hiroki , Miyasaka Hitoshi
Published: December 2017

Phase transitions caused by the charge instability between the neutral and ionic phases of compounds, i.e., N–I phase transitions, provide avenues for switching the intrinsic properties of compounds related to electron/spin correlation and dipole generation as well as charge distribution. However, it is extremely difficult to control the transition temperature (Tc) for the N–I phase transition, and only chemical modification based on the original material have been investigated. Here, a design overview of the tuning of N–I phase transition by interstitial guest molecules is presented. This study reports a new chain coordination‐polymer [Ru2(3,4‐Cl2PhCO2)4TCNQ(EtO)2]∙DCE (1‐DCE; 3,4‐Cl2PhCO2− = 3,4‐dichlorobenzoate; TCNQ(EtO)2 2,5‐diethoxy‐7,7,8,8‐tetracyanoquinodimethane; and DCE = 1,2‐dichloroethane) that exhibits a one‐step N–I transition at 230 K (= Tc) with the N‐ and I‐states possessing a simple paramagnetic state and a ferrimagnetically correlated state for the high‐ and low‐temperature phases, respectively. The Tc continuously decreases depending on the content of DCE, which eventually disappears with the complete evacuation of DCE, affording solvent‐free compound 1 with the N‐state in the entire temperature range (this behavior is reversible). This is an example of tuning the in situ Tc for the N–I phase transition via the control of the interstitial guest molecules.
Unveiling the Influence of Surface Fermi Level Pinning on the Piezoelectric Response of Semiconducting Nanowires
Authors: Tao Ran , Mouis Mireille , Ardila Gustavo
Published: December 2017

ZnO nanowires (NWs) are excellent candidates for the integration of energy harvesters, mechanical sensors, piezotronic and piezophototronic devices. However, ZnO NWs are usually nonintentionally n‐doped during their growth. Thus, it can be expected theoretically that their piezoelectric response be degraded and mostly geometry‐independent as a result of strong screening effects by free carriers, while experimentally many NW‐based piezoelectric transducers demonstrate quite reasonable performance. In this paper, this apparent contradiction is explained by surface Fermi level pinning (SFLP). Simulations based on the finite element method are developed to investigate the influence of SFLP on the electrical response of ZnO piezogenerators based on arrays of vertical ZnO NWs (the so‐called VING) operated in compression or bending mode. The results show that the nonsymmetrical response with respect to loading direction, which has been observed experimentally when the VING is bent, can be explained when account is taken of the reverse piezoelectric effect associated with SFLP. Influence of geometry and comparison to thin film are also discussed. It is found that the performance improvement, which is observed experimentally at scales much larger than predicted by ab initio models when NWs are compared to thin films, can be partly related to SFLP effects rather than larger piezoelectric coefficients.
Epitaxial CuN Films with Highly Tunable Lattice Constant for Lattice‐Matched Magnetic Heterostructures with Enhanced Thermal Stability
Authors: Wen Zhenchao , Kubota Takahide , Takanashi Koki
Published: December 2017

The engineering of advanced materials for lattice‐matched magnetic heterostructures with remarkable magnetoelectric properties is of particular importance for future spintronic devices. Here, epitaxial CuN films with highly tunable lattice constant and resistivity are fabricated. The lattice constant of the CuN films is controlled from 0.362 to 0.388 nm, and the resistivity is varied over a range of more than two orders of magnitude. Lattice‐matched CuN/Co2Fe0.4Mn0.6Si (CFMS) heterostructures are achieved. A dramatic enhancement of the thermal stability of the heterostructure over that of Cu/CFMS is observed. Furthermore, magnetoresistance nanojunctions are fabricated using lattice‐matched CuN spacers, and an enhancement of the magnetoresistance effect at high annealing temperatures is observed. This work shows that the manipulation of the lattice constant and resistivity of CuN films in lattice‐matched heterostructures can be important for engineering future advanced electronic materials for the development of spintronic devices.
Aqueous‐Processed Polymer/Nanocrystal Hybrid Solar Cells with Double‐Side Bulk Heterojunction
Authors: Jin Gan , Chen Nannan , Zeng Qingsen , Liu Fangyuan , Yuan Wei , Xiang Siyuan , Feng Tanglue , Du Xiaohang , Ji Tianjiao , Wang Lijing , Wang Yaohua , Sun Henan , Sun Haizhu , Yang Bai
Published: December 2017

Aqueous‐solution‐processed solar cells (ASCs) are promising candidates of the next‐generation large‐area, low‐cost, and flexible photovoltaic conversion equipment because of their unique environmental friendly property. Aqueous‐solution‐processed polymer/nanocrystals (NCs) hybrid solar cells (AHSCs) can effectively integrate the advantages of the polymer (e.g., flexibility and lightweight) and the inorganic NCs (e.g., high mobility and broad absorption), and therefore be considered as an ideal system to further improve the performance of ASCs. In this work, double‐side bulk heterojunction (BHJ), in which one BHJ combines the active material with electron transport material and the other combines the active material with hole transport material, is developed in the AHSCs. Through comparing with the single‐side BHJ device, promoted carrier extraction, enhanced internal quantum efficiency, extended width of the depletion region, and prolonged carrier lifetime are achieved in double‐side BHJ devices. As a result, power conversion efficiency exceeding 6% is obtained, which breaks the bottleneck efficiency around ≈5.5%. This work demonstrates a device architecture which is more remarkable compared with the traditional only donor–acceptor blended BHJ. Under conservative estimation, it provides instructive architecture not only in the ASCs, but also in the organic solar cells (SCs), quantum dot SCs, and perovskite SCs.
Alkaline Benzoquinone Aqueous Flow Battery for Large‐Scale Storage of Electrical Energy
Authors: Yang Zhengjin , Tong Liuchuan , Tabor Daniel P. , Beh Eugene S. , Goulet Marc‐Antoni , De Porcellinis Diana , Aspuru‐Guzik Alán , Gordon Roy G. , Aziz Michael J.
Published: December 2017

An aqueous flow battery based on low‐cost, nonflammable, noncorrosive, and earth‐abundant elements is introduced. During charging, electrons are stored in a concentrated water solution of 2,5‐dihydroxy‐1,4‐benzoquinone, which rapidly receives electrons with inexpensive carbon electrodes without the assistance of any metal electrocatalyst. Electrons are withdrawn from a second water solution of a food additive, potassium ferrocyanide. When these two solutions flow along opposite sides of a cation‐conducting membrane, this flow battery delivers a cell potential of 1.21 V, a peak galvanic power density of 300 mW cm−2, and a coulombic efficiency exceeding 99%. Continuous cell cycling at 100 mA cm−2 shows a capacity retention rate of 99.76% cycle−1 over 150 cycles. Various molecular modifications involving substitution for hydrogens on the aryl ring are implemented to block decomposition by nucleophilic attack of hydroxide ions. These modifications result in increased capacity retention rates of up to 99.96% cycle−1 over 400 consecutive cycles, accompanied by changes in voltage, solubility, kinetics, and cell resistance. Quantum chemistry calculations of a large number of organic compounds predict a number of related structures that should have even higher performance and stability. Flow batteries based on alkaline‐soluble dihydroxybenzoquinones and derivatives are promising candidates for large‐scale, stationary storage of electrical energy.
Effect of Cation Composition on the Mechanical Stability of Perovskite Solar Cells
Authors: Rolston Nicholas , Printz Adam D. , Tracy Jared M. , Weerasinghe Hasitha C. , Vak Doojin , Haur Lew Jia , Priyadarshi Anish , Mathews Nripan , Slotcavage Daniel J. , McGehee Michael D. , Kalan Roghi E. , Zielinski Kenneth , Grimm Ronald L. , Tsai Hsinhan , Nie Wanyi , Mohite Aditya D. , Gholipour Somayeh , Saliba Michael , Grätzel Michael , Dauskardt Reinhold H.
Published: December 2017

Photoactive perovskite semiconductors are highly tunable, with numerous inorganic and organic cations readily incorporated to modify optoelectronic properties. However, despite the importance of device reliability and long service lifetimes, the effects of various cations on the mechanical properties of perovskites are largely overlooked. In this study, the cohesion energy of perovskites containing various cation combinations of methylammonium, formamidinium, cesium, butylammonium, and 5‐aminovaleric acid is reported. A trade‐off is observed between the mechanical integrity and the efficiency of perovskite devices. High efficiency devices exhibit decreased cohesion, which is attributed to reduced grain sizes with the inclusion of additional cations and PbI2 additives. Microindentation hardness testing is performed to estimate the fracture toughness of single‐crystal perovskite, and the results indicated perovskites are inherently fragile, even in the absence of grain boundaries and defects. The devices found to have the highest fracture energies are perovskites infiltrated into a porous TiO2/ZrO2/C triple layer, which provide extrinsic reinforcement and shielding for enhanced mechanical and chemical stability.
Effect of Alkylsilyl Side‐Chain Structure on Photovoltaic Properties of Conjugated Polymer Donors
Authors: Bin Haijun , Yang Yankang , Peng Zhengxing , Ye Long , Yao Jia , Zhong Lian , Sun Chenkai , Gao Liang , Huang He , Li Xiaojun , Qiu Beibei , Xue Lingwei , Zhang Zhi‐Guo , Ade Harald , Li Yongfang
Published: December 2017

Side‐chain engineering is an important strategy for optimizing photovoltaic properties of organic photovoltaic materials. In this work, the effect of alkylsilyl side‐chain structure on the photovoltaic properties of medium bandgap conjugated polymer donors is studied by synthesizing four new polymers J70, J72, J73, and J74 on the basis of highly efficient polymer donor J71 by changing alkyl substituents of the alkylsilyl side chains of the polymers. And the photovoltaic properties of the five polymers are studied by fabricating polymer solar cells (PSCs) with the polymers as donor and an n‐type organic semiconductor (n‐OS) m‐ITIC as acceptor. It is found that the shorter and linear alkylsilyl side chain could afford ordered molecular packing, stronger absorption coefficient, higher charge carrier mobility, thus results in higher Jsc and fill factor values in the corresponding PSCs. While the polymers with longer or branched alkyl substituents in the trialkylsilyl group show lower‐lying highest occupied molecular orbital energy levels which leads to higher Voc of the PSCs. The PSCs based on J70:m‐ITIC and J71:m‐ITIC achieve power conversion efficiency (PCE) of 11.62 and 12.05%, respectively, which are among the top values of the PSCs reported in the literatures so far.
3D Porous Carbon Sheets with Multidirectional Ion Pathways for Fast and Durable Lithium–Sulfur Batteries
Authors: Li Gaoran , Lei Wen , Luo Dan , Deng Ya‐Ping , Wang Deli , Chen Zhongwei
Published: December 2017

In this work, unique porous carbon sheets (PCSs) are developed via a facile synthesis. The obtained PCS delivers long‐range conductive framework, abundant active interfaces, rich element doping, and notably a high inner porosity that builds up an admirable 3D network for multidirectional ion transfer. Such unique architecture and surface chemistry enable ultrafast sulfur electrochemistry as well as high‐efficiency inhibition on polysulfide shuttling via the dually physical and chemical sulfur confinement. The PCS‐based sulfur electrodes achieve superb rate capability up to 10 C, outstanding cyclability over 1000 cycles, and high areal capacity of 4.8 mA h cm−2. This work offers an appealing model of material engineering for fast and reliable lithium–sulfur batteries, as well as guidance for rational structural design in extended energy storage and conversion systems.
Recent Progress and Perspective in Electrode Materials for K‐Ion Batteries
Authors: Kim Haegyeom , Kim Jae Chul , Bianchini Matteo , Seo Dong‐Hwa , Rodriguez‐Garcia Jorge , Ceder Gerbrand
Published: December 2017

The development of rechargeable batteries using K ions as charge carriers has recently attracted considerable attention in the search for cost‐effective and large‐scale energy storage systems. In light of this trend, various materials for positive and negative electrodes are proposed and evaluated for application in K‐ion batteries. Here, a comprehensive review of ongoing materials research on nonaqueous K‐ion batteries is offered. Information on the status of new materials discovery and insights to help understand the K‐storage mechanisms are provided. In addition, strategies to enhance the electrochemical properties of K‐ion batteries and computational approaches to better understand their thermodynamic properties are included. Finally, K‐ion batteries are compared to competing Li and Na systems and pragmatic opportunities and future research directions are discussed.
Progressive deafness–dystonia due to SERAC1 mutations: A study of 67 cases
Authors: Maas Roeltje R. , Iwanicka‐Pronicka Katarzyna , Kalkan Ucar Sema , Alhaddad Bader , AlSayed Moeenaldeen , Al‐Owain Mohammed A. , Al‐Zaidan Hamad I. , Balasubramaniam Shanti , Barić Ivo , Bubshait Dalal K. , Burlina Alberto , Christodoulou John , Chung Wendy K. , Colombo Roberto , Darin Niklas , Freisinger Peter , Garcia Silva Maria Teresa , Grunewald Stephanie , Haack Tobias B. , van Hasselt Peter M. , Hikmat Omar , Hörster Friederike , Isohanni Pirjo , Ramzan Khushnooda , Kovacs‐Nagy Reka , Krumina Zita , Martin‐Hernandez Elena , Mayr Johannes A. , McClean Patricia , De Meirleir Linda , Naess Karin , Ngu Lock H. , Pajdowska Magdalena , Rahman Shamima , Riordan Gillian , Riley Lisa , Roeben Benjamin , Rutsch Frank , Santer Rene , Schiff Manuel , Seders Martine , Sequeira Silvia , Sperl Wolfgang , Staufner Christian , Synofzik Matthis , Taylor Robert W. , Trubicka Joanna , Tsiakas Konstantinos , Unal Ozlem , Wassmer Evangeline , Wedatilake Yehani , Wolff Toni , Prokisch Holger , Morava Eva , Pronicka Ewa , Wevers Ron A. , de Brouwer Arjan P. , Wortmann Saskia B.
Published: December 2017

Objective

3‐Methylglutaconic aciduria, dystonia–deafness, hepatopathy, encephalopathy, Leigh‐like syndrome (MEGDHEL) syndrome is caused by biallelic variants in SERAC1.

Methods

This multicenter study addressed the course of disease for each organ system. Metabolic, neuroradiological, and genetic findings are reported.

Results

Sixty‐seven individuals (39 previously unreported) from 59 families were included (age range = 5 days–33.4 years, median age = 9 years). A total of 41 different SERAC1 variants were identified, including 20 that have not been reported before. With the exception of 2 families with a milder phenotype, all affected individuals showed a strikingly homogeneous phenotype and time course. Severe, reversible neonatal liver dysfunction and hypoglycemia were seen in >40% of all cases. Starting at a median age of 6 months, muscular hypotonia (91%) was seen, followed by progressive spasticity (82%, median onset = 15 months) and dystonia (82%, 18 months). The majority of affected individuals never learned to walk (68%). Seventy‐nine percent suffered hearing loss, 58% never learned to speak, and nearly all had significant intellectual disability (88%). Magnetic resonance imaging features were accordingly homogenous, with bilateral basal ganglia involvement (98%); the characteristic “putaminal eye” was seen in 53%. The urinary marker 3‐methylglutaconic aciduria was present in virtually all patients (98%). Supportive treatment focused on spasticity and drooling, and was effective in the individuals treated; hearing aids or cochlear implants did not improve communication skills.

Interpretation

MEGDHEL syndrome is a progressive deafness–dystonia syndrome with frequent and reversible neonatal liver involvement and a strikingly homogenous course of disease. Ann Neurol 2017;82:1004–1015
Single‐unit activities during the transition to seizures in deep mesial structures
Authors: Lambrecq Virginie , Lehongre Katia , Adam Claude , Frazzini Valério , Mathon Bertrand , Clemenceau Stéphane , Hasboun Dominique , Charpier Stéphane , Baulac Michel , Navarro Vincent , Le Van Quyen Michel
Published: December 2017

Focal seizures are assumed to arise from a hypersynchronous activity affecting a circumscribed brain region. Using microelectrodes in seizure‐generating deep mesial regions of 9 patients, we investigated the firing of hundreds of single neurons before, during, and after ictal electroencephalogram (EEG) discharges. Neuronal spiking activity at seizure initiation was highly heterogeneous and not hypersynchronous. Furthermore, groups of neurons showed significant changes in activity minutes before the seizure with no concomitant changes in the corresponding macroscopic EEG recordings. Altogether, our findings suggest that only limited subsets of neurons in epileptic depth regions initiate the seizure‐onset and that ictogenic mechanisms operate in submillimeter‐scale microdomains. Ann Neurol 2017 Ann Neurol 2017;82:1022–1028
Mangan(I)‐katalysierte C‐H‐(2‐Indolyl)methylierung: ein einfacher Zugang zu Diheteroarylmethan‐Derivaten
Authors: Lu Qingquan , Cembellín Sara , Greßies Steffen , Singha Santanu , Daniliuc Constantin G. , Glorius Frank
Published: December 2017

Eine neuartige MnI‐katalysierte (2‐Indolyl)methylierung von Heteroarenen wird beschrieben. Diese Methode nutzt eine Aromatisierungskaskadenstrategie, um eine (2‐Indolyl)methyl‐Gruppe im Produkt einzubauen, was zur einfachen Synthese von vorher schwer herzustellenden, wichtigen unsymmetrischen Diheteroarylmethan‐Derivaten, insbesondere Bis(2‐indolyl)methan‐Derivaten, führt. Der vorgeschlagene Kaskadenprozess umfasst die Reorganisation von mehreren Bindungen bei kontrollierter Regioselektivität und hoher Atomökonomie und kann im Gramm‐Maßstab durchgeführt werden. Außerdem wird eine metallfreie C‐H‐Propargylierung beobachtet. Die vielfältige Anwendung dieser Methode wird ebenfalls demonstriert.
Standoff Mid‐Infrared Emissive Imaging Spectroscopy for Identification and Mapping of Materials in Polychrome Objects
Authors: Gabrieli Francesca , Dooley Kathryn A. , Zeibel Jason G. , Howe James D. , Delaney John K.
Published: December 2017

Microscale mid‐infrared (mid‐IR) imaging spectroscopy is used for the mapping of chemical functional groups. The extension to macroscale imaging requires that either the mid‐IR radiation reflected off or that emitted by the object be greater than the radiation from the thermal background. Reflectance spectra can be obtained using an active IR source to increase the amount of radiation reflected off the object, but rapid heating of greater than 4 °C can occur, which is a problem for paintings. Rather than using an active source, by placing a highly reflective tube between the painting and camera and introducing a low temperature source, thermal radiation from the room can be reduced, allowing the IR radiation emitted by the painting to dominate. Thus, emissivity spectra of the object can be recovered. Using this technique, mid‐IR emissivity image cubes of paintings were collected at high collection rates with a low‐noise, line‐scanning imaging spectrometer, which allowed pigments and paint binders to be identified and mapped.
Conversion of Olefins into Ketones by an Iron‐Catalyzed Wacker‐type Oxidation Using Oxygen as the Sole Oxidant
Authors: Puls Florian , Knölker Hans‐Joachim
Published: December 2017

We describe a mild and operationally simple procedure for the oxidation of olefins into ketones. The reaction is catalyzed by the hexadecafluorinated iron–phthalocyanine complex FePcF16 with stoichiometric amounts of triethylsilane as an additive under oxygen atmosphere to give ketones in good to high yields with excellent chemoselectivity and functional group tolerance. Ketone formation proceeds in up to 95 % yield and with 100 % regioselectivity while the corresponding alcohols were observed as side products.
Steigerung der Katalysatoreffizienz in der C‐H‐Aktivierungskatalyse
Authors: Gensch Tobias , James Michael J. , Dalton Toryn , Glorius Frank
Published: December 2017

Nur wenige Katalysatoren erreichen hohe Umsatzzahlen in Reaktionen zur Aktivierung von C‐H‐Bindungen. Stattdessen werden üblicherweise 10 Mol‐% eines Katalysators in solchen Reaktionen eingesetzt. Wir geben eine repräsentative Übersicht über effiziente Katalysatornutzung in der C‐H‐Aktivierung, um diesem vernachlässigten Aspekt der Katalyseforschung mehr Aufmerksamkeit zukommen zu lassen und zukünftige Entwicklungen noch effizienterer C‐H‐Aktivierungen zu inspirieren. Wir zeigen Beispiele aus der Palladiumkatalyse, Cp*RhIII‐ und Cp*CoIII‐katalysierter Reaktionen, der Borylierung und Silylierung von C‐H‐Bindungen sowie der C‐H‐Aktivierung von Methan. In diesen Reaktionen wurden bis zu zehntausende Katalysatorumsätze beobachtet.
Quantitative Screening of Cell‐Surface Gangliosides by Nondestructive Extraction and Hydrophobic Collection
Authors: Chen Yunlong , Liu Huipu , Xiong Yingying , Ju Huangxian
Published: December 2017

A screening strategy involving designed extractors and collectors was used for the nondestructive quantitation of gangliosides on cell surfaces. The extractors were constructed by functionalizing maleimide silica bubbles with a DNA probe, which contains an endonuclease cleavage site and a boronic acid end to extract cell‐surface sialic acid‐containing compounds through simple centrifugation. After the extractors containing the extracted compounds were incubated with endonuclease, the released oligonucleotide‐gangliosides were selectively collected by silanized collector bubbles through hydrophobic interactions. The in vitro fluorescent signals from the collectors were used for the quantitation of cell‐surface gangliosides. By combining with sialidase cleavage, a protocol for the identification of ganglioside subtypes was developed. The successful monitoring of the regeneration of cell‐surface gangliosides demonstrates the potential of this strategy in probing related biological processes.
Selective Oxidative [4+2] Imine/Alkene Annulation with H2 Liberation Induced by Photo‐Oxidation
Authors: Hu Xia , Zhang Guoting , Bu Faxiang , Lei Aiwen
Published: December 2017

The oxidative [4+2] annulation reaction represents an elegant and versatile synthetic protocol for the construction of six‐membered heterocyclic compounds. Herein, a photoinduced oxidative [4+2] annulation of NH imines and alkenes was developed by utilizing a dual photoredox/cobaloxime catalytic system. Various multisubstituted 3,4‐dihydroisoquinolines can be obtained in good yields. This method is not only obviated the need of stiochiometric amounts of oxidants but also exhibited excellent atom economy by generating H2 as the only byproduct. Remarkably, high regioselectivity and trans diastereoselectivity can be achieved in this transformation even if the Z/E mixture of alkenes were employed.
Chemoselectivity Control in the Asymmetric Hydrogenation of γ‐ and δ‐Keto Esters into Hydroxy Esters or Diols
Authors: Arai Noriyoshi , Namba Takanori , Kawaguchi Kei , Matsumoto Yuki , Ohkuma Takeshi
Published: December 2017

The asymmetric hydrogenation of aromatic γ‐ and δ‐keto esters into optically active hydroxy esters or diols under the catalysis of a novel DIPSkewphos/3‐AMIQ–RuII complex was studied. Under the optimized conditions (8 atm H2 , Ru complex/t‐C4H9OK=1:3.5, 25 °C) the γ‐ and δ‐hydroxy esters (including γ‐lactones) were obtained quantitatively with 97–99 % ee. When the reaction was conducted under somewhat harsh conditions (20 atm H2 , [t‐C4H9OK]=50 mm, 40 °C), the 1,4‐ and 1,5‐diols were obtained predominantly with 95–99 % ee. The reactivity of the ester group was notably dependent on the length of the carbon spacer between the two carbonyl moieties of the substrate. The reaction of β‐ and ϵ‐keto esters selectively afforded the hydroxy esters regardless of the reaction conditions. This catalyst system was applied to the enantioselective and regioselective (for one of the two ester groups) hydrogenation of a γ‐ϵ‐diketo diester into a trihydroxy ester.
Enantioselective Photochemical Organocascade Catalysis
Authors: Woźniak Łukasz , Magagnano Giandomenico , Melchiorre Paolo
Published: December 2017

Reported herein is a photochemical cascade process that combines the excited‐state and ground‐state reactivity of chiral organocatalytic intermediates. This strategy directly converts racemic cyclopropanols and α,β‐unsaturated aldehydes into stereochemically dense cyclopentanols with exquisite stereoselectivity. Mechanistic investigations have enabled elucidating the origin of the stereoconvergence, which is governed by a kinetic resolution process.
Covalent Organic Frameworks and Cage Compounds: Design and Applications of Polymeric and Discrete Organic Scaffolds
Authors: Beuerle Florian , Gole Bappaditya
Published: December 2017

Porous organic materials are an emerging class of functional nanostructures with unprecedented properties. Dynamic covalent assembly of small organic building blocks under thermodynamic control is utilized for the intriguingly simple formation of complex molecular architectures in one‐pot procedures. In this Review, we aim to analyze the basic design principles that govern the formation of either covalent organic frameworks as crystalline porous polymers or covalent organic cage compounds as shape‐persistent molecular objects. Common synthetic procedures and characterization techniques will be discussed as well as more advanced strategies such as postsynthetic modification or self‐sorting. When appropriate, comparisons are drawn between polymeric frameworks and discrete organic cages in terms of their underlying properties. Furthermore, we highlight the potential of these materials for applications ranging from gas storage to catalysis and organic electronics.
One‐pot synthesis of cobalt‐incorporated polyglycerol ester as an antimicrobial agent for polyurethane coatings
Authors: Chua Bing Wei , Lee Choy Sin , Lim Wen Huei , Pichika Mallikarjuna Rao
Published: December 2017

Cobalt‐incorporated poly(glycerol ester) (Co–PGE) was synthesized by the polycondensation of glycerol and adipic acid followed by the reaction with cobalt(II) hydroxide under solvent‐free and noncatalyzed one‐pot synthesis conditions. The reaction was monitored through the acid value and hydroxyl value determination. The chemical structure and molecular weight of the poly(glycerol ester) (PGE) and Co–PGE were characterized by Fourier transform infrared spectroscopy, 13C‐NMR, gel permeation chromatography, and inductively coupled plasma mass spectrometry. Co–PGE with a 59.3% degree of branching was incorporated with up to 5.0% w/w cobalt, and it exhibited antimicrobial inhibition against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans in a broth microdilution study. Polyurethane (PU) coatings were prepared by the blending of 0.5–35% w/w Co‐PGE containing with 5% w/w of cobalt with blank PGE, poly(ethylene glycol) with a molecular weight of 6000, poly(caprolactone diol) with a molecular weight of 2000, and additives to react with isophorone diisocyanate. The prepared PUs demonstrated mild to high antimicrobial activities against E. coli, S. aureus, Bacillus subtilis, and C. albicans strains in a disc diffusion test. PU prepared with 0.5% w/w Co–PGE showed a mild inhibition activity against S. aureus, and PU prepared with 10% w/w Co–PGE demonstrated a high inhibition activity against C. albicans. This study demonstrated that value‐added Co–PGE synthesized from glycerol has the potential as an antimicrobial agent for polymer coatings in biomedical devices. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46045.
Toughening polylactide with epoxidized styrene–butadiene impact resin: Mechanical, morphological, and rheological characterization
Authors: Wang Yanshai , Wei Zhiyong , Li Yang
Published: December 2017

Styrene–butadiene impact resin (SBC) was chosen as the toughening agent to improve the tensile toughness of polylactide (PLA). Epoxidized SBC (ESBC) with different epoxidation degree were prepared by epoxidation using in situ peroxoformic acid method and a series of PLA/SBC(ESBC) blends were prepared by melt blending. The elongation at break of the PLA/ESBC blends was greatly improved, which was reflected in the slight decrease in the tensile strength and tensile modulus. Moreover, the tensile strength and tensile modulus were not significantly affected by the epoxidation degree of ESBC. For example, the incorporation of ESBC28.8% (30 wt %) to PLA caused an obvious increment of elongation at break from 3.5% of pure PLA to 305.0%, while the tensile modulus and tensile strength decreased to 80 and 78% of pure PLA, respectively. Scanning electron microscopy observations of cryo‐fractured surface morphology and particle size analysis demonstrated that the compatibility of the PLA/ESBC blends was improved significantly compared to PLA/SBC blend. PLA/ESBC(70/30) blends exhibited shear‐thinning behavior over the range of the studied shear rate. With an increase in shear rate, the non‐Newtonian index of the blends decreased gradually. Furthermore, the flow behavior of PLA/ESBC(70/30) blends was more sensitive to the shear rate than pure PLA. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46058.
A new thermoset for separation of polystyrene and naphthalene in preparative chromatography
Authors: de Oliveira Rosa Wesley , Botaro Vagner R.
Published: December 2017

Many research groups in recent years have demonstrated the importance of obtaining new materials and reducing environmental impact. In this context, the chemical modification of cellulose and its derivatives has received much attention. This study synthesized cellulose acetate gel (CAMDIH) obtained through the modification of cellulose acetate (CA) with a degree of substitution of 2.5, by crosslinking reactions using 4,4′‐diphenylmethane diisocyanate in homogeneous medium. The formation of crosslinks were observed by the presence of Fourier transform infrared spectroscopy absorption bands at 3046 and 864 cm−1, which correspond to the absorption of aromatic groups associated with the incorporation of 4,4′‐diphenylmethane diisocyanate in the CA structure. The potential applications of the gel as a stationary phase were tested using column chromatography in the fractionation and separation of standard solutions of polystyrene and naphthalene. The findings showed the effectiveness of the gel as a stationary state in the separation of mixture compounds. Furthermore, the study found that CAMDHI is an innovative material when considering its simple synthesis and the low costs involved in the process. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46063.
Dissecting the role of sessional anatomy teachers: A systematic literature review
Authors: Rhodes Danielle , Fogg Quentin A. , Lazarus Michelle D.
Published: December 2017

Worldwide there is a growing reliance on sessional teachers in universities. This has impacted all disciplines in higher education including medical anatomy programs. The objective of this review was to define the role and support needs of sessional anatomy teachers by reporting on the (1) qualifications, (2) teaching role, (3) training, and (4) performance management of this group of educators. A systematic literature search was conducted on the 27 July 2017 in Scopus, Web of Science, and several databases on the Ovid, ProQuest and EBSCOhost platforms. The search retrieved 5,658 articles, with 39 deemed eligible for inclusion. The qualifications and educational distance between sessional anatomy teachers and their students varied widely. Reports of cross‐level, near‐peer and reciprocal‐peer teaching were identified, with most institutes utilizing recent medical graduates or medical students as sessional teachers. Sessional anatomy teachers were engaged in the full spectrum of teaching‐related duties from assisting students with cadaveric dissection, to marking student assessments and developing course materials. Fourteen institutes reported that training was provided to sessional anatomy teachers, but the specific content, objectives, methods and effectiveness of the training programs were rarely defined. Evaluations of sessional anatomy teacher performance primarily relied on subjective feedback measures such as student surveys (n = 18) or teacher self‐assessment (n = 3). The results of this systematic review highlight the need for rigorous explorations of the use of sessional anatomy teachers in medical education, and the development of evidence‐based policies and training programs that regulate and support the use of sessional teachers in higher education. Anat Sci Educ 11: 410–426. © 2017 American Association of Anatomists.
Online instructional anatomy videos: Student usage, self‐efficacy, and performance in upper limb regional anatomy assessment
Authors: Langfield Tracey , Colthorpe Kay , Ainscough Louise
Published: December 2017

Allied health professionals concur that a sound knowledge of practical gross anatomy is vital for the clinician, however, human anatomy courses in allied health programs have been identified as high‐risk for attrition and failure. While anatomists and clinicians agree that learning anatomy via human cadaveric instruction is the preferred method, students vary in their reaction to the cadaveric learning experience and have differing levels of anatomy self‐efficacy. This study investigated whether student self‐efficacy had an effect on student usage of supplemental instructional videos and whether the use of videos had an impact on student self‐efficacy and/or learning. Anatomy self‐efficacy differed based on gender and prior performance. Student usage of the videos varied widely and students with lower self‐efficacy were more inclined to use the resources. The provision of the videos did not improve overall cohort performance as compared to a historical cohort, however, those students that accessed all video sets experienced a greater normalized learning gain compared to students that used none or one of the four sets of videos. Student reports and usage patterns indicate that the videos were primarily used for practical class preparation and revision. Potentially, the videos represent a passive mode of teaching whereas active learning has been demonstrated to result in greater learning gains. Adapting the videos into interactive tutorials which will provide opportunity for feedback and the development of students' self‐evaluation may be more appropriate. Anat Sci Educ 11: 461–470. © 2017 American Association of Anatomists.
Measuring the diffusion of an innovation: A citation analysis
Authors: Zhai Yujia , Ding Ying , Wang Fang
Published: December 2017

Innovations transform our research traditions and become the driving force to advance individual, group, and social creativity. Meanwhile, interdisciplinary research is increasingly being promoted as a route to advance the complex challenges we face as a society. In this paper, we use Latent Dirichlet Allocation (LDA) citation as a proxy context for the diffusion of an innovation. With an analysis of topic evolution, we divide the diffusion process into five stages: testing and evaluation, implementation, improvement, extending, and fading. Through a correlation analysis of topic and subject, we show the application of LDA in different subjects. We also reveal the cross‐boundary diffusion between different subjects based on the analysis of the interdisciplinary studies. The results show that as LDA is transferred into different areas, the adoption of each subject is relatively adjacent to those with similar research interests. Our findings further support researchers' understanding of the impact formation of innovation.
The Qualitative Properties of Symmetric Open‐Loop Nash Equilibria in the State‐Control Dynamic System in Differential Games
Authors: Hsueh Shao‐Chieh , Ling Chen
Published: December 2017

The local stability, steady state comparative statics, and local comparative dynamics of symmetric open‐loop Nash equilibria in the state‐control dynamic system for a seemingly ubiquitous class of discounted infinite horizon differential games are investigated. It is shown that most of the useful qualitative results occur because the same small number of assumptions is being made about the mathematical structure of the integrand and/or state equations. Applications of the results to exhaustible resource extraction and capital accumulation differential games are provided.
Effect of uncertainties in sea surface temperature dataset on the simulation of typhoon Nangka (2015)
Authors: Fu Hao , Wang Yuqing
Published: December 2017

Accurate sea surface temperature (SST) datasets are critical to typhoon simulation/prediction, especially to the intensity forecast. In this study, four SST datasets were used to perform a series of experiments to examine the effects of different SST datasets and a cold SST feature on the simulation of typhoon Nangka (2015) using the Advanced Weather Research and Forecast model. Results show that the simulated typhoon intensity is very sensitive to the SST dataset used. The experiments with the SST dataset in which a cold SST feature to the south of the storm track was present/absent succeeded/failed to simulate the peak intensity and the subsequent rapid weakening of typhoon Nangka. Among the four datasets examined, only the SST dataset from the National Centers for Environmental Prediction Global Forecast System analysis captured the cold SST feature, which was likely induced by typhoon Chan‐Hom (2015) before the arrival of typhoon Nangka.
Planning accelerated life tests with random effects of test chambers
Authors: Seo Kangwon , Pan Rong
Published: December 2017

In accelerated life tests (ALTs), test units are often tested in multiple test chambers along with different stress conditions. The nonhomogeneity of test chambers precludes the complete randomized experiment and may affect the life‐stress relationship of the test product. The chamber‐to‐chamber variation should be taken into account for ALT planning so as to obtain more accurate test results. In this paper, planning ALTs under a nested experimental design structure with random test chamber effects is studied. First, by a 2‐phase approach, we illustrate to what extent different test chamber assignments to stress conditions may impact the estimation of unknown parameters. Then,D‐optimal test plans with 2 test chambers are considered. To construct the optimal design, we establish the generalized linear mixed model for failure‐time data and apply a quasi‐likelihood method, where test chamber assignments, as well as other decision variables that are required for planning ALTs, are simultaneously determined.
Analysis of definitive screening designs: Screening vs prediction
Authors: Weese Maria L. , Ramsey Philip J. , Montgomery Douglas C.
Published: December 2017

The use of definitive screening designs (DSDs) has been increasing since their introduction in 2011. These designs are used to screen factors and to make predictions. We assert that the choice of analysis method for these designs depends on the goal of the experiment, screening, or prediction. In this work, we present simulation results to address the explanatory (screening) use and the predictive use of DSDs. To address the predictive ability of DSDs, we use two 5‐factor DSDs and simultaneously run central composite designs case studies on which we will compare several common analysis methods. Overall, we find that for screening purposes, the Dantzig selector using the Bayesian Information Criterion statistic is a good analysis choice; however, when the goal of analysis is prediction forward selection using the Bayesian Information Criterion statistic produces models with a lower mean squared prediction error.
Transposable Element Mediated Innovation in Gene Regulatory Landscapes of Cells: Re‐Visiting the “Gene‐Battery” Model
Authors: Sundaram Vasavi , Wang Ting
Published: December 2017

Transposable elements (TEs) are no longer considered to be “junk” DNA. Here, we review how TEs can impact gene regulation systematically. TEs encode various regulatory elements that enables them to regulate gene expression. RJ Britten and EH Davidson hypothesized that TEs can integrate the function of various transcriptional regulators into gene regulatory networks. Uniquely TEs can deposit regulatory sites across the genome when they transpose, and thereby bring multiple genes under control of the same regulatory logic. Several studies together have robustly established that TEs participate in embryonic development and oncogenesis. We discuss the regulatory characteristics of TEs in context of evolution to understand the extent of their impact on gene networks. Understanding these features of TEs is central to future investigations of TEs in cellular processes and phenotypic presentations, which are applicable to development and disease studies. We re‐visit the Britten–Davidson “gene‐battery” model and understand the genetic and transcriptional impact of TEs in innovating gene regulatory networks.
Amphiphilic lysine conjugated to tobramycin synergizes legacy antibiotics against wild‐type and multidrug‐resistant Pseudomonas aeruginosa
Authors: Lyu Yinfeng , Domalaon Ronald , Yang Xuan , Schweizer Frank
Published: December 2017

Peptidomimetic modification is a common route of optimization for biologically active peptides. Previous studies in our group have shown that conjugation of amphiphilic tobramycin to other antibacterials enhance their latent outer membrane permeabilizing and efflux blocking activity toward Gram‐negative pathogens including Pseudomonas aeruginosa. Herein, we describe the antimicrobial adjuvant properties of amphiphilic lysine ligated to tobramycin. The most potent amphiphilic lysine‐tobramycin conjugate 3 potentiated the antibacterial efficacy of 8 clinically used antibiotics against wild type, multidrug‐ and extensively drug‐resistant P. aeruginosa isolates from Canadian hospitals whereas amphiphilic lysine 4 did not. Antibiotics that are synergistic with conjugate 3 included moxifloxacin, ciprofloxacin, erythromycin, chloramphenicol, trimethoprim, novobiocin, linezolid, and fosfomycin. Out of these 8 antibiotics, novobiocin showed highest synergy.
Redox‐Induced Switching of the Viscoelasticity of DNA Layers Observed by using Electrochemical Quartz Crystal Microbalance on the Millisecond Timescale
Authors: Peter Jörg , Galagedera Sarasi K.K. , Flechsig Gerd‐Uwe
Published: December 2017

The interactions of single‐stranded DNA (ssDNA) immobilized on gold electrodes with hexammine ruthenium(III) (RuHex) and hexammine cobalt(III) (CoHex) were investigated with chronocoulometric and electrochemical quartz crystal microbalance experiments. The modified surfaces were created by immobilizing ssDNA with tris(dithioserinol) linkers to form a compact, self‐assembled monolayer, followed by passivation with 6‐mercapto‐1‐hexanol (MCH). Upon addition of the redox indicator during a potential jump for RuHex and CoHex, we observed a dramatic increase in the frequency response in comparison to the signal observed with only low‐ionic‐strength hybridization buffer, 10 mM tris(hydroxymethyl)‐aminomethane (Tris)/H2SO4 (pH 7.4). RuHex and CoHex responded quite differently, even on a millisecond time scale. As the expected mass change is less than a factor of 35 to the observed frequency response, we concluded that the applied potential jumps lead to switching of the DNA layer viscoelasticity.
Effect of A/B‐Site Non‐stoichiometry on the Structure and Properties of La0.9Sr0.1Ga0.9Mg0.1O3−δ Solid Electrolyte in Intermediate‐Temperature Solid Oxide Fuel Cells
Authors: Wang Jian Qiu , Zhou De Feng , Gao Jin Quan , Sun Hao Ran , Zhu Xiao Fei , Meng Jian
Published: December 2017

(La0.9Sr0.1)x(Ga0.9Mg0.1)yO3‐δ [(LS)x(GM)y] (x=0.97, 1.00, 1.03; y=1.00 and x=1.00; y=0.97, 1.00, 1.03) electrolyte is prepared through a sol‐gel method followed by sintering at 1300 °C for 10 h. The microstructures of the samples are characterized by using X‐ray diffraction (XRD) and field‐emission scanning electron microscopy (FE‐SEM). The electrical and thermal stability properties are measured by means of electrochemical impedance spectroscopy (EIS) and thermal expansion coefficient (TEC), respectively. It is shown that phase purity could improve by adjusting the non‐stoichiometry of A/B‐site. This, in turn, affects the conductivity and thermal expansion of the solid electrolyte. The samples with B‐site defects [LS(GM)0.97] are found to exhibit the best phase purity and density with minimal grain boundary/total resistances, and superior thermal stability. The conductivity of LS(GM)0.97 is 1.56 time higher than that of LSGM. The average thermal expansion coefficient of LS(GM)0.97 at 50–850 °C is 4.13 % lower than that of LSGM. The maximum power density of single cells containing LS(GM)0.97 electrolyte could reach 0.54 W cm−1 at 800 °C, which is 16.7 % higher than that of cells containing LSGM electrolyte. The stability test for over 120 h at 800 °C indicates a slight decrease in performances during the first 10 h, but no significant differences in electrode polarization are observed even after long‐term operation. These findings suggest the potential applications of LS(GM)0.97 as a novel electrolyte for intermediate‐temperature solid oxide fuel cells.
Analytical Understanding of the Materials Design with Well‐Described Shrinkages on Multiscale
Authors: Ma Qiang , Dutta Saikat , Wu Kevin C.‐W. , Kimura Tatsuo
Published: December 2017

Shrinkages derived from condensation of frameworks are one of the significant steps for fabricating demanded materials having unique morphologies and properties. Enormous efforts have been dedicated to understanding their mechanisms that are quite useful for the materials design. In this context, diversified measuring and observing tools have been facilitated to evaluate structural contractions and corresponding driving forces. All of the investigations are crucial to encourage the utilization of such shrinkages for the precise design of nanomaterials. In this review, we summarize significant works how to analyze shrinkages in multiscale during the synthesis of materials, which will be useful as a follow‐up review to our latest contribution. Well‐defined porous materials are also selected as a good candidate for understanding well‐described shrinkages. This review aims to provide a detailed glimpse of the development of analyses on shrinking behaviors in multiscale for the materials design. Shrinking degree and direction in multiscale, which are driven by condensation of frameworks, are predominant for understanding and/or predicting final nanostructures of materials after shrinkages.