bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectroscopic Studies on the Metal–Insulator Transition Mechanism in Correlated Materials
Authors: Kim So Yeun , Lee Min‐Cheol , Han Garam , Kratochvilova Marie , Yun Seokhwan , Moon Soon Jae , Sohn Changhee , Park Je‐Geun , Kim Changyoung , Noh Tae Won 
Published: May 2018

AbstractThe metal–insulator transition (MIT) in correlated materials is a novel phenomenon that accompanies a large change in resistivity, often many orders of magnitude. It is important in its own right but its switching behavior in resistivity can be useful for device applications. From the material physics point of view, the starting point of the research on the MIT should be to understand the microscopic mechanism. Here, an overview of recent efforts to unravel the microscopic mechanisms for various types of MITs in correlated materials is provided. Research has focused on transition metal oxides (TMOs), but transition metal chalcogenides have also been studied. Along the way, a new class of MIT materials is discovered, the so‐called relativistic Mott insulators in 5d TMOs. Distortions in the MO6 (M = transition metal) octahedron are found to have a large and peculiar effect on the band structure in an orbital dependent way, possibly paving a way to the orbital selective Mott transition. In the final section, the character of the materials suitable for applications is summarized, followed by a brief discussion of some of the efforts to control MITs in correlated materials, including a dynamical approach using light.
Ultrastretchable Conductor Fabricated on Skin‐Like Hydrogel–Elastomer Hybrid Substrates for Skin Electronics
Authors: Kim Sun Hong , Jung Sungmook , Yoon In Seon , Lee Chihak , Oh Youngsu , Hong Jae‐Min 
Published: May 2018

AbstractPrinting technology can be used for manufacturing stretchable electrodes, which represent essential parts of wearable devices requiring relatively high degrees of stretchability and conductivity. In this work, a strategy for fabricating printable and highly stretchable conductors are proposed by transferring printed Ag ink onto stretchable substrates comprising Ecoflex elastomer and tough hydrogel layers using a water‐soluble tape. The elastic modulus of the produced hybrid film is close to that of the hydrogel layer, since the thickness of Ecoflex elastomer film coated on hydrogel is very thin (30 µm). Moreover, the fabricated conductor on hybrid film is stretched up to 1780% strain. The described transfer method is simpler than other techniques utilizing elastomer stamps or sacrificial layers and enables application of printable electronics to the substrates with low elastic moduli (such as hydrogels). The integration of printed electronics with skin‐like low‐modulus substrates can be applied to make wearable devices more comfortable for human skin.
Caging Nb2O5 Nanowires in PECVD‐Derived Graphene Capsules toward Bendable Sodium‐Ion Hybrid Supercapacitors
Authors: Wang Xiangguo , Li Qiucheng , Zhang Li , Hu Zhongli , Yu Lianghao , Jiang Tao , Lu Chen , Yan Chenglin , Sun Jingyu , Liu Zhongfan 
Published: May 2018

AbstractSodium‐ion hybrid supercapacitors (Na‐HSCs) by virtue of synergizing the merits of batteries and supercapacitors have attracted considerable attention for high‐energy and high‐power energy‐storage applications. Orthorhombic Nb2O5 (T‐Nb2O5) has recently been recognized as a promising anode material for Na‐HSCs due to its typical pseudocapacitive feature, but it suffers from intrinsically low electrical conductivity. Reasonably high electrochemical performance of T‐Nb2O5‐based electrodes could merely be gained to date when sufficient carbon content was introduced. In addition, flexible Na‐HSC devices have scarcely been demonstrated by far. Herein, an in situ encapsulation strategy is devised to directly grow ultrathin graphene shells over T‐Nb2O5 nanowires (denoted as Gr‐Nb2O5 composites) by plasma‐enhanced chemical vapor deposition, targeting a highly conductive anode material for Na‐HSCs. The few‐layered graphene capsules with ample topological defects would enable facile electron and Na+ ion transport, guaranteeing rapid pseudocapacitive processes at the Nb2O5/electrolyte interface. The Na‐HSC full‐cell comprising a Gr‐Nb2O5 anode and an activated carbon cathode delivers high energy/power densities (112.9 Wh kg−1/80.1 W kg−1 and 62.2 Wh kg−1/5330 W kg−1), outperforming those of recently reported Na‐HSC counterparts. Proof‐of‐concept Na‐HSC devices with favorable mechanical robustness manifest stable electrochemical performances under different bending conditions and after various bending–release cycles.
Generalized Access to Mesoporous Inorganic Particles and Hollow Spheres from Multicomponent Polymer Blends
Authors: Hwang Jongkook , Kim Seongseop , Wiesner Ulrich , Lee Jinwoo 
Published: May 2018

AbstractMesoporous inorganic particles and hollow spheres are of increasing interest for a broad range of applications, but synthesis approaches are typically material specific, complex, or lack control over desired structures. Here it is reported how combining mesoscale block copolymer (BCP) directed inorganic materials self‐assembly and macroscale spinodal decomposition can be employed in multicomponent BCP/hydrophilic inorganic precursor blends with homopolymers to prepare mesoporous inorganic particles with controlled meso‐ and macrostructures. The homogeneous multicomponent blend solution undergoes dual phase separation upon solvent evaporation. Microphase‐separated (BCP/inorganic precursor)‐domains are confined within the macrophase‐separated majority homopolymer matrix, being self‐organized toward particle shapes that minimize the total interfacial area/energy. The pore orientation and particle shape (solid spheres, oblate ellipsoids, hollow spheres) are tailored by changing the kind of homopolymer matrix and associated enthalpic interactions. Furthermore, the sizes of particle and hollow inner cavity are tailored by changing the relative amount of homopolymer matrix and the rates of solvent evaporation. Pyrolysis yields discrete mesoporous inorganic particles and hollow spheres. The present approach enables a high degree of control over pore structure, orientation, and size (15–44 nm), particle shape, particle size (0.6–3 µm), inner cavity size (120–700 nm), and chemical composition (e.g., aluminosilicates, carbon, and metal oxides).
Nanomaterial‐Based Organelles Protect Normal Cells against Chemotherapy‐Induced Cytotoxicity
Authors: Zhao Ruibo , Liu Xueyao , Yang Xinyan , Jin Biao , Shao Changyu , Kang Weijia , Tang Ruikang 
Published: May 2018

AbstractChemotherapy‐induced cytotoxicity in normal cells and organs triggers undesired lesions. Although targeted delivery is used extensively, more than half of the chemotherapy dose still concentrates in normal tissues, especially in the liver. Enabling normal cells or organs to defend against cytotoxicity represents an alternative method for improving chemotherapy. Herein, rationally designed nanomaterials are used as artificial organelles to remove unexpected cytotoxicity in normal cells. Nanocomposites of gold‐oligonucleotides (Au‐ODN) can capture intracytoplasmic doxorubicin (DOX), a standard chemotherapy drug, blocking the drug's access into the cell nucleus. Cells with implanted Au‐ODN are more robust since their viability is maintained during DOX treatment. In vivo experiments confirm that the Au‐ODN nanomaterials selectively concentrate in hepatocytes and eliminate DOX‐induced hepatotoxicity, increasing the cell's capacity to resist the threatening chemotherapeutic milieu. The finding suggests that introducing functional materials as biological devices into living systems may be a new strategy for improving the regulation of cell fate in more complex conditions and for manufacturing super cells.
Magnetic Encoding Plasmonic Janus Microbead‐Based Suspension Array for High Sensitivity Multiplex Analysis
Authors: Sheng Tao , Xie Zhuoying , Liu Panmiao , Chen Jialun , Chen Shan , Ding Hailong , Deng Jingzhe , Yuan Yi , Deng Dawei 
Published: May 2018

AbstractIn this study, a new kind of magnetic encoding Janus microbead‐based array with nanoplasmonic‐assisted fluorescence enhancement for highly sensitive multiplex immunoassay is developed. These plasmonic Janus microbeads are encoded by magnetic content and decoded by corresponding magnetic field intensity. With the plasmonic Janus microbeads, the fluorescence intensity has increased by a factor of 180 and the lower detection limit has improved by ≈1000‐fold—as low as 100 × 10−15
m. The application of plasmonic Janus microbeads is also demonstrated in highly sensitive multiplex immunoassay. It is believed that the magnetic encoding plasmonic Janus microbeads will extend the application of nanoplasmonic‐assisted fluorescence enhancement of microbead‐based arrays in immunofluorescence analysis and have high potential in early diagnosis.
Gold‐Catalyzed Intermolecular [4+2] Annulation of 2‐Ethynylanilines with Ynamides: An Access to Substituted 2‐Aminoquinolines
Authors: Zhao Ximei , Song Xinlong , Jin Hongming , Zeng Zhongyi , Wang Qian , Rudolph Matthias , Rominger Frank , Hashmi A. Stephen K. 
Published: May 2018

AbstractA gold‐catalyzed intermolecular [4+2] annulation of easily accessible 2‐ethynylanilines with ynamides offers a highly region‐selective, modular, efficient, and atom‐economical strategy for the synthesis of substituted 2‐aminoquinolines in up to 93% yield.magnified image
Tetra‐substituted Dipolar Carbazoles: Tuning Optical and Electroluminescence Properties by Linkage Variation
Authors: Joseph Vellaichamy , Justin Thomas K. R. , Yang Wan Yun , Kumar Yadav Rohit Ashok , Kumar Dubey Deepak , Jou Jwo‐Huei 
Published: May 2018

AbstractSix isomeric carbazole derivatives featuring donors such as triphenylamine and carbazole and cyano acceptor are synthesized and characterized. Triphenylamine substituted compounds displayed longer wavelength absorption and emission and improved thermal stability when compared to their carbazole congeners. The compounds containing donors at 2,7‐position of carbazole core displayed negative solvatochromism in absorption while the other isomers showed solvent independent absorption profiles. Except the dye containing carbazole at 1,8‐positions, all the dyes exhibited solvatochromism in excited state. Within a series dyes containing donors at 1,8‐positions exhibited shorter wavelength absorption and emission due to the significant twisting of chromophores at 1,8‐positions. The dyes possessing donor at 2,7‐positions and cyano groups at 3,6‐positions showed best electroluminescence performance (external quantum efficiency, 4.1 %) in the series owing to their ability to utilize triplet excitons via hybridized local and charge transfer excited state.
Enantiomeric and Diastereomeric Self‐Assembled Multivalent Nanostructures: Understanding the Effects of Chirality on Binding to Polyanionic Heparin and DNA
Authors: Thornalley Kiri A. , Laurini Erik , Pricl Sabrina , Smith David K. 
Published: May 2018

AbstractA family of four self‐assembling lipopeptides containing Ala‐Lys peptides attached to a C16 aliphatic chain were synthesised. These compounds form two enantiomeric pairs that bear a diastereomeric relationship to one another (C16‐l‐Ala‐l‐Lys/C16‐d‐Ala‐d‐Lys) and (C16‐d‐Ala‐l‐Lys/C16‐l‐Ala‐d‐Lys). These diastereomeric pairs have very different critical micelle concentrations (CMCs). The self‐assembled multivalent (SAMul) systems bind biological polyanions as a result of the cationic lysine groups on their surfaces. For heparin binding, there was no significant enantioselectivity, but there was a binding preference for the diastereomeric assemblies with lower CMCs. Conversely, for DNA binding, there was significant enantioselectivity for systems displaying d‐lysine ligands, with a further slight preference for attachment to l‐alanine, with the CMC being irrelevant.
C‐H‐Aktivierung ermöglicht eine kurze Totalsynthese von Chinin und Analoga mit erhöhter Anti‐Malaria‐Aktivität
Authors: O' Donovan Daniel H. , Aillard Paul , Berger Martin , de la Torre Aurélien , Petkova Desislava , Knittl‐Frank Christian , Geerdink Danny , Kaiser Marcel , Maulide Nuno 
Published: May 2018

AbstractWir berichten über einen neuen Ansatz zum klassischen Naturprodukt Chinin, der auf zwei stereoselektiven Schlüsselschritten, nämlich einer C(sp3)‐H‐Aktivierung und einer Aldol‐Reaktion, welche die beiden heterocyclischen Fragmente des Zielmoleküls vereinigt, basiert. Diese direkte und flexible Strategie ermöglicht eine kurze Synthese von natürlichem (−)‐Chinin und die erste Synthese von nichtnatürlichem (+)‐Chinin, und sie bietet Zugang zu bisher unbekannten C3‐Aryl‐Analoga, welche in nur 6 Stufen hergestellt werden können. Des Weiteren zeigen wir, dass diese strukturellen Analoga, im Vergleich zu (−)‐Chinin, eine erhöhte Anti‐Malaria‐Aktivität sowohl in vitro als auch in vivo, an mit Plasmodium berghei infizierten Mäusen, aufweisen.
Aerobic Oxidation of 5‐(Hydroxymethyl)furfural Cyclic Acetal Enables Selective Furan‐2,5‐dicarboxylic Acid Formation with CeO2‐Supported Gold Catalyst
Authors: Kim Minjune , Su Yaqiong , Fukuoka Atsushi , Hensen Emiel J. M. , Nakajima Kiyotaka 
Published: May 2018

AbstractThe utilization of 5‐(hydroxymethyl)furfural (HMF) for the large‐scale production of essential chemicals has been largely limited by the formation of solid humin as a byproduct, which prevents the operation of stepwise batch‐type and continuous flow‐type processes. The reaction of HMF with 1,3‐propanediol produces an HMF acetal derivative that exhibits excellent thermal stability. Aerobic oxidation of the HMF acetal with a CeO2‐supported Au catalyst and Na2CO3 in water gives a 90–95 % yield of furan 2,5‐dicarboxylic acid, an increasingly important commodity chemical for the biorenewables industry, from concentrated solutions (10–20 wt %) without humin formation. The six‐membered acetal ring suppresses thermal decomposition and self‐polymerization of HMF in concentrated solutions. Kinetic studies supported by DFT calculations identify two crucial steps in the reaction mechanism, that is, the partial hydrolysis of the acetal into 5‐formyl‐2‐furan carboxylic acid involving OH− and Lewis acid sites on CeO2, and subsequent oxidative dehydrogenation of the in situ generated hemiacetal involving Au nanoparticles. These results represent a significant advance over the current state of the art, overcoming an inherent limitation of the oxidation of HMF to an important monomer for biopolymer production.
Efficient Visible‐Light‐Driven CO2 Reduction Mediated by Defect‐Engineered BiOBr Atomic Layers
Authors: Wu Ju , Li Xiaodong , Shi Wen , Ling Peiquan , Sun Yongfu , Jiao Xingchen , Gao Shan , Liang Liang , Xu Jiaqi , Yan Wensheng , Wang Chengming , Xie Yi 
Published: May 2018

AbstractSolar CO2 reduction efficiency is largely limited by poor photoabsorption, sluggish electron–hole separation, and a high CO2 activation barrier. Defect engineering was employed to optimize these crucial processes. As a prototype, BiOBr atomic layers were fabricated and abundant oxygen vacancies were deliberately created on their surfaces. X‐ray absorption near‐edge structure and electron paramagnetic resonance spectra confirm the formation of oxygen vacancies. Theoretical calculations reveal the creation of new defect levels resulting from the oxygen vacancies, which extends the photoresponse into the visible‐light region. The charge delocalization around the oxygen vacancies contributes to CO2 conversion into COOH* intermediate, which was confirmed by in situ Fourier‐transform infrared spectroscopy. Surface photovoltage spectra and time‐resolved fluorescence emission decay spectra indicate that the introduced oxygen vacancies promote the separation of carriers. As a result, the oxygen‐deficient BiOBr atomic layers achieve visible‐light‐driven CO2 reduction with a CO formation rate of 87.4 μmol g−1 h−1, which was not only 20 and 24 times higher than that of BiOBr atomic layers and bulk BiOBr, respectively, but also outperformed most previously reported single photocatalysts under comparable conditions.
Rb3VO(O2)2CO3: A Four‐in‐One Carbonatoperoxovanadate Exhibiting an Extremely Strong Second‐Harmonic Generation Response
Authors: Zou Guohong , Jo Hongil , Lim Seong‐Ji , You Tae‐Soo , Ok Kang Min 
Published: May 2018

AbstractA nonlinear optical (NLO) carbonatoperoxovanadate, Rb3VO(O2)2CO3, was synthesized through a simple solution‐evaporation method in phase‐pure form. Single‐crystal X‐ray diffraction revealed that the structure of Rb3VO(O2)2CO3 consists of important noncentrosymmetric (NCS) chromophores, that is, π‐delocalized (CO3)2− groups, a second‐order Jahn–Teller (SOJT) distortive V5+ cation, and π‐localized distorted O22− groups, as well as charge‐balancing polarizable Rb+ ions. The powder second‐harmonic generation (SHG) measurements indicated that Rb3VO(O2)2CO3 is phase‐matchable (Type I) and exhibits a remarkably strong SHG response circa 21.0 times that of potassium dihydrogen phosphate (KDP), which is the largest efficiency observed among carbonate NLO materials. First‐principles calculation analysis suggests that the extremely large SHG response of Rb3VO(O2)2CO3 is attributed to the synergistic effect of the cooperation of all the constituting NCS chromophores.
C−H Activation Enables a Concise Total Synthesis of Quinine and Analogues with Enhanced Antimalarial Activity
Authors: O' Donovan Daniel H. , Aillard Paul , Berger Martin , de la Torre Aurélien , Petkova Desislava , Knittl‐Frank Christian , Geerdink Danny , Kaiser Marcel , Maulide Nuno 
Published: May 2018

AbstractWe report a novel approach to the classical natural product quinine that is based on two stereoselective key steps, namely a C−H activation and an aldol reaction, to unite the two heterocyclic moieties of the target molecule. This straightforward and flexible strategy enables a concise synthesis of natural (−)‐quinine, the first synthesis of unnatural (+)‐quinine, and also provides access to unprecedented C3‐aryl analogues, which were prepared in only six steps. We additionally demonstrate that these structural analogues exhibit improved antimalarial activity compared with (−)‐quinine both in vitro and in mice infected with Plasmodium berghei.
Fabrication of porous three‐dimensional fibroin structures through a freezing process
Authors: Kolahreez Davood , Morshed Mohammad 
Published: May 2018

ABSTRACTSilk fibroin has been investigated for various biomedical applications. In this research, through a green process, without using freeze‐drying, which is energy consuming during a single step process that is completely aqueous‐based, without using any additional materials during or after structure formation, water‐insoluble silk fibroin sponges have been obtained; these achieved only through keeping fibroin solutions frozen at a suitable temperature for a sufficient time. The effect of solution concentration and freezing conditions on the pore morphology and size, microstructure, and mechanical properties was investigated. A discussion has been proposed for the formation of structures. The average measured pore sizes were approximately from 4 to 77 μm. Elastic modules of the investigated structures varied from about 100 to 900 kPa. Cyclic mechanical tests were performed; the remaining strain of the structures reached to about 1%. A less considered issue which can be considered as the possible significant change of the mechanical behavior of as‐prepared samples after one or more times of loading and unloading should be noted. The used method in this study as a cost effective and convenient procedure could have the potential for application in the production of porous structures for biomedical applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46537.
Evaluation of poly(methylsilane‐carbosilane) synthesized from methyl‐dichlorosilane and chloromethyldichloromethylsilane as a precursor for SiC
Authors: Wang Xinliang , Chen Yi , Li Yongming , Xu Caihong 
Published: May 2018

ABSTRACTA new poly(methylsilane‐carbosilane) (PMSCS) for silicon carbide precursor was synthesized by Wurtz‐type copolycondensation of methyldichlorosilane (MeHSiCl2) with chloromethyldichloromethylsilane (ClCH2MeSiCl2) and terminated with vinylmagnesium chloride (ViMgCl). The use of insufficient sodium made the reaction more economic and safe. By changing the ratios of two monomers and the end‐block agent, the properties of the obtained PMSCS and the C/Si ratio of its derived ceramic could be tuned. Upon pyrolysis at 1000 °C under argon, silicon carbide with nearly stoichiometric C/Si ratio and low oxygen content was obtained in 64% of ceramic yield. PMSCS showed high potential as an economical SiC ceramic precursor for the fabrication of SiC matrix, coating, and adhesives. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46610.
Highly efficient adsorbent for organic dyes based on a temperature‐ and pH‐responsive multiblock polymer
Authors: Yang Zhenglong , Chen Sai , Fu Kangyu , Liu Xinyan , Li Feng , Du Yuchuan , Zhou Peiting , Cheng Zhihao 
Published: May 2018

ABSTRACTThe self‐assembly behavior of amphiphilic block copolymers in selective solutions has many applications in environmentally responsive polymer materials. In this article, we report on a new amphiphilic, temperature and pH dual‐responsive poly[2‐dimethylaminoethyl methacrylate‐co‐(methyl methacrylate)]‐b‐poly[poly(ethylene glycol) methacrylate] [P(DMAEMA‐co‐MMA)‐b‐PPEGMA], which was synthesized via reversible addition–fragmentation chain‐transfer polymerization. The structure, self‐assembly behaviors, and process of organic dye adsorption were characterized by 1H‐NMR, ultraviolet–visible absorbance spectroscopy, and DLS measurements. P(DMAEMA‐co‐MMA)‐b‐PPEGMA was proven to be an outstanding adsorbent with excellent reversibility. Methyl red was released from the micelles as the pH value of the solution was adjusted to 4, and it could also be encapsulated again when the pH value was adjusted to 7.4 because of the sensitive pH‐responsive ability. It is promising that the triblock polymer had a positive effect on dye adsorption for environmental protection. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46626.