bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pt Nanoparticles Sensitized Ordered Mesoporous WO3 Semiconductor: Gas Sensing Performance and Mechanism Study
Authors: Ma Junhao , Ren Yuan , Zhou Xinran , Liu Liangliang , Zhu Yongheng , Cheng Xiaowei , Xu Pengcheng , Li Xinxin , Deng Yonghui , Zhao Dongyuan 
Published: December 2017

AbstractIn this study, a straightforward coassembly strategy is demonstrated to synthesize Pt sensitized mesoporous WO3 with crystalline framework through the simultaneous coassembly of amphiphilic poly(ethylene oxide)‐b‐polystyrene, hydrophobic platinum precursors, and hydrophilic tungsten precursors. The obtained WO3/Pt nanocomposites possess large pore size (≈13 nm), high surface area (128 m2 g−1), large pore volume (0.32 cm3 g−1), and Pt nanoparticles (≈4 nm) in situ homogeneously distributed in mesopores, and they exhibit excellent catalytic sensing response to CO of low concentration at low working temperature with good sensitivity, ultrashort response‐recovery time (16 s/1 s), and high selectivity. In‐depth study reveals that besides the contribution from the fast diffusion of gaseous molecules and rich interfaces in mesoporous WO3/Pt nanocomposites, the partially oxidized Pt nanoparticles that chemically and electronically sensitize the crystalline WO3 matrix, dramatically enhance the sensitivity and selectivity.
Advances in Stimulus‐Responsive Polymeric Materials for Systemic Delivery of Nucleic Acids
Authors: Sun Minjie , Wang Kaikai , Oupický David 
Published: December 2017

AbstractPolymeric materials that respond to a variety of endogenous and external stimuli are actively developed to overcome the main barriers to successful systemic delivery of therapeutic nucleic acids. Here, an overview of viable stimuli that are proved to improve systemic delivery of nucleic acids is provided. The main focus is placed on nucleic acid delivery systems (NADS) based on polymers that respond to pathological or physiological changes in pH, redox state, enzyme levels, hypoxia, and reactive oxygen species levels. Additional discussion is focused on NADS suitable for applications that use external stimuli, such as light, ultrasound, and local hyperthermia.
Theranostic 2D Tantalum Carbide (MXene)
Authors: Lin Han , Wang Youwei , Gao Shanshan , Chen Yu , Shi Jianlin 
Published: December 2017

AbstractThe large‐dimensional and rigid ceramic bulks fabricated by high‐temperature solid‐phase reaction and sintering have never been considered for possibly entering and circulating within the blood vessels for biomedical applications, especially on combating cancer. Here, it is reported for the first time that MAX ceramic biomaterials exhibit unique functionalities for dual‐mode photoacoustic/computed tomography imaging and are highly effective for in vivo photothermal ablation of tumors upon being exfoliated into ultrathin nanosheets within atomic thickness (MXene). As a paradigm, 2D ultrathin tantalum carbide nanosheets (Ta4C3 MXenes) with nanosized lateral sizes are successfully synthesized based on a two‐step liquid exfoliation strategy of MAX phase Ta4AlC3 by combined hydrofluoric acid (HF) etching and probe sonication. The structural, electronic, and surface characteristics of the as‐exfoliated nanosheets are revealed by various characterizations combined with first‐principles calculations via density functional theory. Especially, the superior photothermal‐conversion performance (efficiency η of 44.7%) and in vitro/in vivo photothermal ablation of tumor by biocompatible soybean phospholipid‐modified Ta4C3 nanosheets are systematically revealed and demonstrated. Based on the large family members of MXenes, this work may offer a paradigm that MXenes can achieve the specific biomedical applications (here, theranostic) providing that their compositions and nanostructures are carefully tuned and optimized to meet the strict requirements of biomedicine.
A Carbonyl Compound‐Based Flexible Cathode with Superior Rate Performance and Cyclic Stability for Flexible Lithium‐Ion Batteries
Authors: Amin Kamran , Meng Qinghai , Ahmad Aziz , Cheng Meng , Zhang Miao , Mao Lijuan , Lu Kun , Wei Zhixiang 
Published: December 2017

AbstractA sulfur‐linked carbonyl‐based poly(2,5‐dihydroxyl‐1,4‐benzoquinonyl sulfide) (PDHBQS) compound is synthesized and used as cathode material for lithium‐ion batteries (LIBs). Flexible binder‐free composite cathode with single‐wall carbon nanotubes (PDHBQS–SWCNTs) is then fabricated through vacuum filtration method with SWCNTs. Electrochemical measurements show that PDHBQS–SWCNTs cathode can deliver a discharge capacity of 182 mA h g−1 (0.9 mA h cm−2) at a current rate of 50 mA g−1 and a potential window of 1.5 V–3.5 V. The cathode delivers a capacity of 75 mA h g−1 (0.47 mA h cm−2) at 5000 mA g−1, which confirms its good rate performance at high current density. PDHBQS–SWCNTs flexible cathode retains 89% of its initial capacity at 250 mA g−1 after 500 charge–discharge cycles. Furthermore, large‐area (28 cm2) flexible batteries based on PDHBQS–SWCNTs cathode and lithium foils anode are also assembled. The flexible battery shows good electrochemical activities with continuous bending, which retains 88% of its initial discharge capacity after 2000 bending cycles. The significant capacity, high rate performance, superior cyclic performance, and good flexibility make this material a promising candidate for a future application of flexible LIBs.
A Highly Efficient Oxygen Evolution Catalyst Consisting of Interconnected Nickel–Iron‐Layered Double Hydroxide and Carbon Nanodomains
Authors: Yin Shengming , Tu Wenguang , Sheng Yuan , Du Yonghua , Kraft Markus , Borgna Armando , Xu Rong 
Published: December 2017

AbstractIn this work, a one‐pot solution method for direct synthesis of interconnected ultrafine amorphous NiFe‐layered double hydroxide (NiFe‐LDH) (<5 nm) and nanocarbon using the molecular precursor of metal and carbon sources is presented for the first time. During the solvothermal synthesis of NiFe‐LDH, the organic ligand decomposes and transforms to amorphous carbon with graphitic nanodomains by catalytic effect of Fe. The confined growth of both NiFe‐LDH and carbon in one single sheet results in fully integrated amorphous NiFe‐LDH/C nanohybrid, allowing the harness of the high intrinsic activity of NiFe‐LDH due to (i) amorphous and distorted LDH structure, (ii) enhanced active surface area, and (iii) strong coupling between the active phase and carbon. As such, the resultant NiFe‐LDH/C exhibits superior activity and stability. Different from postdeposition or electrostatic self‐assembly process for the formation of LDH/C composite, this method offers one new opportunity to fabricate high‐performance oxygen evolution reaction and possibly other catalysts.
A Water‐Processable and Bioactive Multivalent Graphene Nanoink for Highly Flexible Bioelectronic Films and Nanofibers
Authors: Cheng Chong , Zhang Jianguang , Li Shuang , Xia Yi , Nie Chuanxiong , Shi Zhenqiang , Cuellar‐Camacho Jose Luis , Ma Nan , Haag Rainer 
Published: December 2017

AbstractThe capabilities of conductive nanomaterials to be produced in liquid form with well‐defined chemical, physical, and biological properties are highly important for the construction of next‐generation flexible bioelectronic devices. Although functional graphene nanomaterials can serve as attractive liquid nanoink platforms for the fabrication of bioelectronics, scalable synthesis of graphene nanoink with an integration of high colloidal stability, water processability, electrochemical activity, and especially bioactivity remains a major challenge. Here, a facile and scalable synthesis of supramolecular‐functionalized multivalent graphene nanoink (mGN‐ink) via [2+1] nitrene cycloaddition is reported. The mGN‐ink unambiguously displays a well‐defined and flat 2D morphology and shows good water processability and bioactivity. The uniquely chemical, physical, and biological properties of mGN‐ink endow the constructed bioelectronic films and nanofibers with high flexibility and durability, suitable conductivity and electrochemical activity, and most importantly, good cellular compatibility and a highly efficient control of stem‐cell spreading and orientation. Overall, for the first time, a water‐processable and bioactive mGN‐ink is developed for the design of flexible and electrochemically active bioelectronic composites and devices, which not only presents manifold possibilities for electronic‐cellular applications but also establishes a new pathway for adapting macroscopic usages of graphene nanomaterials in bionic, biomedical, electronic, and even energy fields.
High‐Capacity and High‐Rate Discharging of a Coenzyme Q10‐Catalyzed Li–O2 Battery
Authors: Zhang Yantao , Wang Liang , Zhang Xiaozheng , Guo Limin , Wang Ying , Peng Zhangquan 
Published: December 2017

AbstractDischarging of the aprotic Li–O2 battery relies on O2 reduction to insulating solid Li2O2, which can either deposit as thin films on the cathode surface or precipitate as large particles in the electrolyte solution. Toward realizing Li–O2 batteries with high capacity and high rate capability, it is crucially important to discharge Li2O2 in the electrolyte solution rather than on the cathode surface. Here, a soluble electrocatalyst of coenzyme Q10 (CoQ10) that can efficaciously drive solution phase formation of Li2O2 in current benchmark ether‐based Li–O2 batteries is reported, which would otherwise lead to Li2O2 surface‐film growth and premature cell death. In the range of current densities of 0.1–0.5 mA cm−2areal, the CoQ10‐catalyzed Li–O2 battery can deliver a discharge capacity that is ≈40–100 times what the pristine Li–O2 battery could achieve. The drastically enhanced electrochemical performance is attributed to the CoQ10 that not only efficiently mediates the electron transfer from the cathode to dissolve O2 but also strongly interacts with the newly formed Li2O2 in solution retarding its precipitation on the cathode surface. The mediated oxygen reduction reaction and the bonding mechanism between CoQ10 and Li2O2 are understood with density functional theory calculations.
Enhanced Negative Photoconductivity in InAs Nanowire Phototransistors Surface‐Modified with Molecular Monolayers
Authors: Shen Lifan , Yip SenPo , Lan Changyong , Shu Lei , Li Dapan , Zhou Ziyao , Wong Chun‐Yuen , Pun Edwin Y. B. , Ho Johnny C. 
Published: December 2017

AbstractNegative photoconductivity (NPC) mechanisms are widely investigated for high‐performance InAs nanowire (NW) phototransistors, where these mechanisms are usually attributed to severe carrier scattering centers, light‐assisted hot electron trapping in the surface oxide, and/or defects induced photogating layer. However, further insights into their photodetecting mechanisms, as well as corresponding performance enhancement of these NW phototransistors, are still very limited. This work reports the NPC behavior in surface‐modified InAs NW phototransistors based on photoexcitation induced majority electron trapping in the bonded sulfur monolayer under optical illumination. In order to enhance hot electron trapping ability of the bonded sulfur layer, aromatic thiolate (ArS−)‐based molecular monolayer with strong electron‐withdrawing group is employed using simple wet chemistry for the surface modification of InAs NW phototransistors. The magnitude of the photoexcitation induced hot electron trapping is increased by the stronger electron‐withdrawing ability of the ArS−‐based molecular monolayer, enabling the hot electrons to be trapped and released more efficiently, resulting in NW phototransistors with good sensitivity, fast photoresponse, and long‐term stability to low intensity visible light. These results confirm the potential of InAs NW phototransistors surface‐passivated with molecular monolayers in the application and realization of high‐sensitive and long‐term stable room temperature nanoscale photodetectors.
Conversion of γ‐ and δ‐Keto Esters into Optically Active Lactams. Transaminases in Cascade Processes
Authors: Mourelle‐Insua Ángela , Zampieri Luiz Arthur , Lavandera Iván , Gotor‐Fernández Vicente 
Published: December 2017

AbstractA one‐pot two‐step enzymatic strategy has been designed for the production of optically active γ‐ and δ‐lactams in aqueous medium under mild conditions. The approach is based on the biotransamination of ethyl or methyl keto esters bearing different alkyl or aryl substitution patterns at α‐position to the ketone functionality. In this manner, the keto esters were transformed into the corresponding amino esters with excellent conversions, which underwent spontaneous cyclisation in the reaction medium without addition of external reagents. Depending on the transaminase selectivity, both lactam enantiomers can be obtained, so initial enzyme screenings were performed using commercially available and made in house enzymes. Reaction conditions were optimised focusing on the substrate concentration, temperature and ratio of amine donor vs acceptor. Thus, ten γ‐ and δ‐lactams were obtained in good to high isolated yields (70–90%) and excellent selectivities (94–99%) after one or two days at 30 or 45 °C.magnified image
Application of Homophthalic Anhydrides as 2C Building Blocks in Catalytic Asymmetric Cyclizations of ortho‐Quinone Methides: Diastereo‐ and Enantioselective Construction of Dihydrocoumarin Frameworks
Authors: Zhang Ting , Ma Chun , Zhou Jia‐Yu , Mei Guang‐Jian , Shi Feng 
Published: December 2017

AbstractA catalytic asymmetric [4+2] cyclization of ortho‐quinone methides with homophthalic anhydrides in the presence of chiral squaramide‐tertiary amine has been established. This method provides dihydrocoumarin frameworks in excellent diastereoselectivities (all >95:5 dr) and high enantioselectivities (81%–98% ee). This reaction represents the first application of homophthalic anhydrides as 2C building blocks in catalytic asymmetric cyclizations. In addition, this approach not only provides a useful method for constructing enantioenriched dihydrocoumarin frameworks but also advances the chemistry of catalytic asymmetric cyclizations of ortho‐quinone methides.magnified image
Asymmetric Amination of α‐Chiral Aliphatic Aldehydes via Dynamic Kinetic Resolution to Access Stereocomplementary Brivaracetam and Pregabalin Precursors
Authors: Fuchs Christine S. , Farnberger Judith E. , Steinkellner Georg , Sattler Johann H. , Pickl Mathias , Simon Robert C. , Zepeck Ferdinand , Gruber Karl , Kroutil Wolfgang 
Published: December 2017

AbstractOver the last decades biocatalysis has emerged as an indispensable and versatile tool for the asymmetric synthesis of active pharmaceutical ingredients (APIs). In this context, especially transaminases (TAs) have been successfully used for the preparation of numerous α‐chiral, optically pure amines, serving as important building blocks for APIs. Here we elaborate on the development of transaminases recognizing the α‐chiral centre adjacent to an aldehyde moiety with aliphatic residues, opening up concepts for novel synthetic routes to the antiepileptic drugs Brivaracetam and Pregabalin. The transformation proceeded via dynamic kinetic resolution (DKR) based on the bio‐induced racemisation of the aldehyde enantiomers, enabling the amination of the racemic substrates with quantitative conversions. Medium, substrate as well as enzyme engineering gave access to both (R)‐ and (S)‐enantiomers of the amine precursors of the stereocomplementary drugs in high optical purity, representing a short route to mentioned APIs.magnified image
Dense Carbon Nanotube Films as Transparent Electrodes in Low‐Voltage Polymer and All‐Carbon Transistors
Authors: Held Martin , Laiho Patrik , Kaskela Antti , Gannott Florentina , Rother Marcel , Kauppinen Esko , Zaumseil Jana 
Published: December 2017

AbstractDense but transparent films of long and clean carbon nanotubes grown by the floating catalyst method, transferred and patterned on glass substrates, are employed as source and drain electrodes in top‐gate field‐effect transistors with both low‐mobility semiconducting polymers and high‐mobility networks of polymer‐sorted semiconducting single‐walled carbon nanotubes. Significant enhancement of ambipolar charge injection into the polymer semiconductor compared to gold electrodes is observed, while the limitations of sheet resistance become apparent for the high‐mobility nanotube transistors. The injection of charges from gold compared to carbon nanotube electrodes into the semiconducting nanotube network is investigated by means of conductive atomic force microscopy indicating a less defined channel edge for the latter. Metal‐free, all‐carbon electrolyte‐gated transistors with a nanotube network semiconductor as well as nanotube source, drain, and gate electrodes show both hole and electron transport at very low operating voltages.
Connecting the Mechanical and Conductive Properties of Conjugated Polymers
Authors: Xie Renxuan , Colby Ralph H. , Gomez Enrique D. 
Published: December 2017

AbstractBoth the mechanical deformability and electronic conductivity of conjugated polymers play important roles in the development of wearable and stretchable electronics. Despite the recent progress and emphasis on achieving highly stretchable and conductive devices, the correlation between the mechanical and conductive properties is poorly understood and remains mostly empirical. The future of flexible electronics relies on the ability to predict and tune the mechanical and conductive properties such that the molecular design of conjugated polymers can be optimized for various applications. Instead of seeking a direct correlation between mechanical and conductive properties, this Progress Report proposes to examine the common microstructural origin for mechanical performance and charge transport in conjugated polymers. Measurements of microstructural information, such as persistence length, chain entanglement, glass transition, liquid crystalline phase transition, and intercrystalline morphology, are desperately needed in the field of conjugated polymers in order to establish connections with both the mechanical/conductive properties and the chemical structures. Conventional experimental methods in the field of flexible polymer physics, such as linear viscoelastic rheometry, open up new avenues for characterizing these microstructural parameters, thereby providing a path toward predicting and designing the molecular structure of conjugated polymers with desired mechanical and conductive properties.
Reconfigurable Si Nanowire Nonvolatile Transistors
Authors: Park So Jeong , Jeon Dae‐Young , Piontek Sabrina , Grube Matthias , Ocker Johannes , Sessi Violetta , Heinzig André , Trommer Jens , Kim Gyu‐Tae , Mikolajick Thomas , Weber Walter M. 
Published: December 2017

AbstractReconfigurable transistors merge unipolar p‐ and n‐type characteristics of field‐effect transistors into a single programmable device. Combinational circuits have shown benefits in area and power consumption by fine‐grain reconfiguration of complete logic blocks at runtime. To complement this volatile programming technology, a proof of concept for individually addressable reconfigurable nonvolatile transistors is presented. A charge‐trapping stack is incorporated, and four distinct and stable states in a single device are demonstrated.
Microwave‐Assisted [4+2] Diels–Alder Cycloaddition of 1,4‐Diethynyl Triptycene with Various Cyclopentadienone Derivatives: Promising Building Blocks for Polymer Networks
Authors: Alameddine Bassam , Baig Noorullah , Shetty Suchetha , Al‐Sagheer Fakhreia , Al‐Mousawi Saleh 
Published: December 2017

AbstractTriptycene derivatives substituted at their 1,4‐ positions with tetraphenylbenzene and diphenyltriphenylene moieties were prepared by microwave‐assisted [4+2] Diels–Alder cycloaddition reactions in very good yields. The target compounds were characterized by 1H and 13C NMR spectroscopy, HRMS, UV/Vis and emission spectrophotometry. In addition, single crystal XRD spectra for two of these derivatives are presented. The tetra‐ and octabrominated triptycene compounds underwent palladium‐catalyzed Suzuki–Miyaura cross‐coupling reactions affording the desired products in very good yields. This successful tetra‐ and octa‐fold substitution paves the way for the employment of these building blocks to prepare polymer networks for various applications.
Enantio‐ and Diastereoselective Cyclopropanation of 1‐Alkenylboronates: Synthesis of 1‐Boryl‐2,3‐Disubstituted Cyclopropanes
Authors: Carreras Javier , Caballero Ana , Pérez Pedro J. 
Published: December 2017

AbstractA novel, highly enantio‐ and diastereoselective synthesis of 1‐boryl‐2,3‐disubstituted cyclopropanes has been developed by means of the cyclopropanation of alkenylboronates with ethyl diazoacetate in the presence of catalytic amounts of a chiral copper(I) complex. The products can also be directly accessed from alkynes through an operationally simple, sequential hydroboration–cyclopropanation protocol. The resulting enantioenriched 1‐boryl‐2,3‐disubstituted cyclopropanes are versatile synthetic intermediates that undergo further transformations at the carbon–boron bond.
Transition‐Metal‐Catalyzed Selective Functionalization of C(sp3)−H Bonds in Natural Products
Authors: Karimov Rashad R. , Hartwig John F. 
Published: December 2017

AbstractDirect functionalization of natural products is important for studying the structure–activity and structure–property relationships of these molecules. Recent advances in the transition‐metal‐catalyzed functionalization of C(sp3)−H bonds, the most abundant yet inert bonds in natural products, have allowed natural product derivatives to be created selectively. Strategies to achieve such transformation are reviewed.
Copper nanoclusters conjugated silica nanoparticles modified on carbon paste as an electrochemical sensor for the determination of dopamine
Authors: Tashkhourian J. , Sheydaei O. , Nami‐Ana S.F. 
Published: December 2017

An electrochemical sensor based on modification of carbon paste electrode by glutathione‐capped copper nanoclusters silica nanoparticles (CuNCs/SiO2NPs) composite for determination of dopamine in the presence of ascorbic acid was presented. Transmission electron microscopy, scanning electron microscopy, energy dispersive X‐Ray analysis, X‐ray photoelectron spectroscopy, Fourier‐transform infrared spectroscopy, X‐ray diffraction and electrochemical impedance spectroscopy were used for characterization of the developed electrode. The electrochemical behavior of dopamine on CuNCs/SiO2NPs/carbon paste electrode was investigated by cyclic voltammetry and differential pulse voltammetry. Dopamine was determined in the range of 10.0 – 900.0 μM, and the limit of detection was obtained as 0.43 μM. The electrochemical behaviors of the coexisting electroactive species, which often cause interference with the determination of dopamine, were investigated. The results show that the developed electrode does not show any interference with respect to coexisting species, even in the presence of ascorbic acid. The developed electrochemical sensor was further employed for the determination of dopamine in human blood plasma, with a good recovery.
Aliphatic SPI charge‐transfer complex hybrid films for high temperature polymer electrolyte membrane fuel cells
Authors: Christiani Liana , Sasaki Kazunari , Nishihara Masamichi 
Published: December 2017

ABSTRACTA new method to synthesize polymer electrolyte membranes based on charge‐transfer (CT) complexes for high temperature fuel cells is investigated. Aliphatic sulfonated polyimide (SPI) CT complex hybrid films are prepared. Aliphatic units are introduced into the SPI main chain to increase the elasticity compared with aromatic SPI films. Electron‐donating compounds are included to form a CT complex, resulting in improved control over mechanical strength, water uptake, and thermal stability. The resulting thermal properties of the SPI CT films are sufficient to operate at elevated temperature (up to 120 °C), and the proton conductivity is comparable to that of Nafion 115. These films are thus promising alternative membranes for high temperature polymer electrolyte fuel cell applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46087.