bluuebunny/crossref_metadata_2025_split huggingface dataset:
Myelin Sheath as a Dielectric Waveguide for Signal Propagation in the Mid‐Infrared to Terahertz Spectral Range
Authors: Liu Guozhi , Chang Chao , Qiao Zhi , Wu Kaijie , Zhu Zhi , Cui Gangqiang , Peng Wenyu , Tang Yuzhao , Li Jiang , Fan Chunhai 
Published: December 2018

AbstractThe myelin sheath enables dramatic speed enhancement for signal propagation in nerves. In this work, myelinated nerve structure is experimentally and theoretically studied using synchrotron‐radiation‐based Fourier‐transform infrared microspectroscopy. It is found that, with a certain mid‐infrared to terahertz spectral range, the myelin sheath possesses a ≈2‐fold higher refraction index compared to the outer medium or the inner axon, suggesting that myelin can serve as an infrared dielectric waveguide. By calculating the correlation between the material characteristics of myelin and the radical energy distribution in myelinated nerves, it is demonstrated that the sheath, with a normal thickness (≈2 µm) and dielectric constant in nature, can confine the infrared field energy within the sheath and enable the propagation of an infrared signal at the millimeter scale without dramatic energy loss. The energy of signal propagation is supplied and amplified when crossing the nodes of Ranvier via periodic relay. These findings provide the first model for explaining the mechanism of infrared and terahertz neurotransmission through myelinated nerves, which may promote the development of biological‐tissue label‐free detection, biomaterial‐based sensors, neural information, and noninvasive brain–machine interfaces.
In‐Plane Anisotropic Thermal Conductivity of Few‐Layered Transition Metal Dichalcogenide Td‐WTe2
Authors: Chen Yu , Peng Bo , Cong Chunxiao , Shang Jingzhi , Wu Lishu , Yang Weihuang , Zhou Jiadong , Yu Peng , Zhang Hongbo , Wang Yanlong , Zou Chenji , Zhang Jing , Liu Sheng , Xiong Qihua , Shao Hezhu , Liu Zheng , Zhang Hao , Huang Wei , Yu Ting 
Published: December 2018

Abstract2D Td‐WTe2 has attracted increasing attention due to its promising applications in spintronic, field‐effect chiral, and high‐efficiency thermoelectric devices. It is known that thermal conductivity plays a crucial role in condensed matter devices, especially in 2D systems where phonons, electrons, and magnons are highly confined and coupled. This work reports the first experimental evidence of in‐plane anisotropic thermal conductivities in suspended Td‐WTe2 samples of different thicknesses, and is also the first demonstration of such anisotropy in 2D transition metal dichalcogenides. The results reveal an obvious anisotropy in the thermal conductivities between the zigzag and armchair axes. The theoretical calculation implies that the in‐plane anisotropy is attributed to the different mean free paths along the two orientations. As thickness decreases, the phonon‐boundary scattering increases faster along the armchair direction, resulting in stronger anisotropy. The findings here are crucial for developing efficient thermal management schemes when engineering thermal‐related applications of a 2D system.
Self‐Assembled Networked PbS Distribution Quantum Dots for Resistive Switching and Artificial Synapse Performance Boost of Memristors
Authors: Yan Xiaobing , Pei Yifei , Chen Huawei , Zhao Jianhui , Zhou Zhenyu , Wang Hong , Zhang Lei , Wang Jingjuan , Li Xiaoyan , Qin Cuiya , Wang Gong , Xiao Zuoao , Zhao Qianlong , Wang Kaiyang , Li Hui , Ren Deliang , Liu Qi , Zhou Hao , Chen Jingsheng , Zhou Peng 
Published: December 2018

AbstractWith the advent of the era of big data, resistive random access memory (RRAM) has become one of the most promising nanoscale memristor devices (MDs) for storing huge amounts of information. However, the switching voltage of the RRAM MDs shows a very broad distribution due to the random formation of the conductive filaments. Here, self‐assembled lead sulfide (PbS) quantum dots (QDs) are used to improve the uniformity of switching parameters of RRAM, which is very simple comparing with other methods. The resistive switching (RS) properties of the MD with the self‐assembled PbS QDs exhibit better performance than those of MDs with pure‐Ga2O3 and randomly distributed PbS QDs, such as a reduced threshold voltage, uniformly distributed SET and RESET voltages, robust retention, fast response time, and low power consumption. This enhanced performance may be attributed to the ordered arrangement of the PbS QDs in the self‐assembled PbS QDs which can efficiently guide the growth direction for the conducting filaments. Moreover, biosynaptic functions and plasticity, are implemented successfully in the MD with the self‐assembled PbS QDs. This work offers a new method of improving memristor performance, which can significantly expand existing applications and facilitate the development of artificial neural systems.
Recent Advances in Nanozyme Research
Authors: Wang Hui , Wan Kaiwei , Shi Xinghua 
Published: December 2018

AbstractAs a new generation of artificial enzymes, nanozymes have the advantages of high catalytic activity, good stability, low cost, and other unique properties of nanomaterials. Due to their wide range of potential applications, they have become an emerging field bridging nanotechnology and biology, attracting researchers in various fields to design and synthesize highly catalytically active nanozymes. However, the thorough understanding of experimental phenomena and the mechanisms beneath practical applications of nanozymes limits their rapid development. Herein, the progress of experimental and computational research of nanozymes on two issues over the past decade is briefly reviewed: (1) experimental development of new nanozymes mimicking different types of enzymes. This covers their structures and applications ranging from biosensing and bioimaging to therapeutics and environmental protection. (2) The catalytic mechanism proposed by experimental and theoretical study. The challenges and future directions of computational research in this field are also discussed.
Sustainable Carbonaceous Materials Derived from Biomass as Metal‐Free Electrocatalysts
Authors: Zhang Zhengping , Yang Shaoxuan , Li Hanyu , Zan Yongxi , Li Xueyan , Zhu Ying , Dou Meiling , Wang Feng 
Published: December 2018

AbstractAlthough carbon is the second most abundant element in the biosphere, a large proportion of the available carbon resources in biomass from agriculture, stock farming, ocean fisheries, and other human activities is currently wasted. The use of sustainable carbonaceous materials as an alternative to precious metals in electrocatalysis is a promising pathway for transforming sustainable biomass resources into sustainable energy‐conversion systems. The development of rational syntheses of metal‐free carbonaceous catalysts derived from sustainable biomass has therefore become a topic of significant interest in materials chemistry. However, great efforts are still required to develop methods that are low cost, scalable, and environmentally friendly and which afford carbonaceous materials having an electrocatalytic performance comparable to, or even better than, existing precious metal catalysts. Herein, recent achievements in developing metal‐free carbonaceous catalysts based on biomass are reviewed and discussed and the critical issues which still need to be addressed are highlighted. The focus is on representative synthesis and optimization strategies applicable to different kinds of biomass, as well as studies of the physicochemical structure and electrochemical performance of the resulting metal‐free carbonaceous catalysts. Finally, some guidelines for the future development of this important area are provided.
The Crown and the Scepter: Roles of the Protein Corona in Nanomedicine
Authors: Cai Rong , Chen Chunying 
Published: December 2018

AbstractEngineering nanomaterials are increasingly considered promising and powerful biomedical tools or devices for imaging, drug delivery, and cancer therapies, but few nanomaterials have been tested in clinical trials. This wide gap between bench discoveries and clinical application is mainly due to the limited understanding of the biological identity of nanomaterials. When they are exposed to the human body, nanoparticles inevitably interact with bodily fluids and thereby adsorb hundreds of biomolecules. A “biomolecular corona” forms on the surface of nanomaterials and confers a new biological identity for NPs, which determines the following biological events: cellular uptake, immune response, biodistribution, clearance, and toxicity. A deep and thorough understanding of the biological effects triggered by the protein corona in vivo will speed up their translation to the clinic. To date, nearly all studies have attempted to characterize the components of protein coronas depending on different physiochemical properties of NPs. Herein, recent advances are reviewed in order to better understand the impact of the biological effects of the nanoparticle–corona on nanomedicine applications. The recent development of the impact of protein corona formation on the pharmacokinetics of nanomedicines is also highlighted. Finally, the challenges and opportunities of nanomedicine toward future clinical applications are discussed.
Facile Synthesis of Nitrogen‐Rich Carbon Dots as Fertilizers for Mung Bean Sprouts
Authors: Wang Aiwu , Kang Fengwen , Wang Zhigang , Shao Qingguo , Li Zhe , Zhu Guangyu , Lu Jian , Li Yang Yang 
Published: December 2018

AbstractNitrogen‐doped carbon‐dots (N‐CDs) are synthesized using a solid‐state method and applied as nanofertilizers. Specifically, 70 g of mung bean seeds are cultivated in the aqueous solution of N‐CDs (0.2 mg mL−1) and yields 646 g of bean sprouts; this yield is significantly higher than that obtained in the pure water control (i.e., 550 g of bean sprouts from 70 g of beans). Furthermore, blue florescence is observed during the sprouting process, which gradually migrates from the beans to the root ends, implying the absorption and migration of the N‐CDs during this process. This work demonstrates that the N‐CDs not only serve as a new fertilizer for promoting plant growth but also enable in vivo monitoring of the plant growth progress of plants, opening up new possibilities of CDs‐related materials for future agricultural applications.
2D/2D Graphitic Carbon Nitride/Antimonene Heterostructure: Structural Characterization and Application in Photocatalysis
Authors: Barrio Jesús , Gibaja Carlos , Tzadikov Jonathan , Shalom Menny , Zamora Félix 
Published: December 2018

AbstractSandwiched van der Waals heterostructures based on the combination of suitable layered materials can give rise to novel nanomaterials with enhanced properties due to synergic effects. In this work, a simple two‐step procedure based on the mixture of two suspensions containing the graphitic carbon nitride and antimonene flakes is used to produce heterostructures of different compositions, CNSbx. The materials have been characterized using spectroscopic, diffractometric, and microscopic techniques. The results confirm that carbon nitride (CN) and antimonene flakes are well‐connected, forming a type I heterojunction. The CNSbx van der Waals heterostructures show improvements in the optical absorption as well as charge separation under illumination, as well as greater photoactivity in the degradation of organic pollutants to that showed for pristine CN. These results suggest potential applications in photoelectrochemical devices for heterostructures based on the combination of CNs with antimonene.
Simultaneous Enhancement of Three Parameters of P3HT‐Based Organic Solar Cells with One Oxygen Atom
Authors: Wu Jianfei , Xu Yunxiao , Yang Zhou , Chen Yusheng , Sui Xinyu , Yang Lei , Ye Pan , Zhu Ting , Wu Xiaoxi , Liu Xinfeng , Cao Hui , Peng Aidong , Huang Hui 
Published: December 2018

AbstractPoly(3‐hexylthiophene) (P3HT)‐based organic solar cells (OSCs) have attracted much attention due to their advantages of low‐cost production and matured roll‐to‐roll manufacture. However, the efficiency of P3HT‐based OSCs lag much behind the non‐P3HT ones due to their negligible absorption of long wavelengths of light over 650 nm, high‐lying highest occupied molecular orbitals (HOMO), and difficulty of controlling morphology. In this study, the alkyl chains of the nonfullerene acceptors are replaced with alkoxy chains to achieve synergistic enhancement of all three parameters ( short circuit current density (JSC), open circuit voltage (VOC), and fill factor (FF)) and thus significant increase of power conversion efficiency for P3HT‐based OSCs. As a result, the OSCs exhibit a maxima efficiency of 6.6%. The P3HT‐based systems are systematically studied with optical spectroscopy, photoluminescence, cyclic voltametry, space charge limit current, grazing incident wide‐angle X‐ray scattering, transient absorption spectroscopy, transmission electron microscope, and atomic force microscopy to probe the mechanism, which reveal that introducing alkoxy chains simultaneously increases the energy levels of the HOMO and the lowest unoccupied molecular orbitals, enhances the light absorption, improves the rigidity of the backbone and charge transport mobility, and tunes the molecular orientation and film morphology, thus improving the photovoltaic performance. This contribution provides an important guidance in the design of novel nonfullerene acceptors for high‐performance P3HT‐based OSCs.
Structurally Reconstructed CsPbI2Br Perovskite for Highly Stable and Square‐Centimeter All‐Inorganic Perovskite Solar Cells
Authors: Liu Chong , Li Wenzhe , Li Huanyong , Wang Huamin , Zhang Cuiling , Yang Yingguo , Gao Xingyu , Xue Qifan , Yip Hin‐Lap , Fan Jiandong , Schropp Ruud E. I. , Mai Yaohua 
Published: December 2018

AbstractAlthough all‐inorganic perovskite solar cells (PSCs) demonstrate high thermal stability, cesium‐lead halide perovskites with high iodine content suffer from poor stability of the black phase (α‐phase). In this study, it is demonstrated that incorporating InCl3 into the host perovskite lattice helps to inhibit the formation of yellow phase (δ‐phase) perovskite and thereby enhances the long‐term ambient stability. The enhanced stability is achieved by a strategy for the structural reconstruction of CsPbI2Br perovskite by means of In3+ and Cl− codoping, which gives rise to a significant improvement in the overall spatial symmetry with a closely packed atom arrangement due to the crystal structure transformation from orthorhombic (Pnma) to cubic (Pm‐3m). In addition, a novel thermal radiation heating method that further improves the uniformity of the perovskite thin films is presented. This approach enables the construction of all‐inorganic InCl3:CsPbI2Br PSCs with a champion power conversion efficiency of 13.74% for a small‐area device (0.09 cm2) and 11.4% for a large‐area device (1.00 cm2).
Easy Access to Water‐Soluble Cationic Porphyrin‐β‐Carboline Conjugates as Potent Photocytotoxic and DNA Cleaving Agents
Authors: Reddy P. O. Venkataramana , Shekar K. P. Chandra , Khandagale Santosh B. , Hara Daiki , Son Aoi , Ito Takeo , Tanabe Kazuhito , Kumar Dalip 
Published: December 2018

AbstractMicrowave (MW)‐assisted efficient and rapid approach is developed to prepare water‐soluble cationic porphyrin‐β‐carboline conjugates by coupling of β‐carboline acid and 5‐(4‐aminophenyl)tripyridyl porphyrin and followed by N‐methylation of neutral porphyrin‐β‐carboline conjugates. Prepared neutral and cationic conjugates were screened for photocytotoxicity against lung (A549) and colon (Colon‐26) cancer cells. Conjugate 9 b was found to be the most potent conjugate with IC50 values ranging 39–47 nM against the tested cancer cell lines. Further, UV‐visible spectroscopy studies demonstrated that the conjugate 9 b in the presence of visible light shows intercalation upon binding to double‐stranded DNA. Additionally, the porphyrin‐β‐carboline conjugate 9 b (2.3×106 M−1) having binding constant (Kb) similar to H2TMPyP (2.5×106 M−1) displayed efficient visible light‐induced DNA cleavage and triggered cell death of A549 cells.
Chemical Protein Synthesis Enabled Mechanistic Studies on the Molecular Recognition of K27‐linked Ubiquitin Chains
Authors: Pan Man , Zheng Qingyun , Ding Shan , Zhang Lujia , Qu Qian , Wang Tian , Hong Danning , Ren Yujing , Liang Lujun , Chen Chunlai , Mei Ziqing , Liu Lei 
Published: December 2018

AbstractNew synthetic strategies that exploited the strengths of both chemoselective ligation and recombinant protein expression were developed to prepare K27 di‐ubiquitins (diUb), which enabled mechanistic studies on the molecular recognition of K27‐linked Ubs by single‐molecule Förster resonance energy transfer (smFRET) and X‐ray crystallography. The results revealed that free K27 diUb adopted a compact conformation, whereas upon binding to UCHL3, K27 diUb was remodeled to an open conformation. The K27 isopeptide bond remained rigidly buried inside the diUb moiety during binding, an interesting unique structural feature that may explain the distinctive biological function of K27 Ub chains.
Steuerung des Grenzflächen‐Ladungstransfers und des Fill‐Factors in CuO‐basierten Grätzel‐Tandemzellen
Authors: Langmar Oliver , Fazio Ettore , Schol Peter , de la Torre Gema , Costa Rubén D. , Torres Tomás , Guldi Dirk M. 
Published: December 2018

AbstractEine neue Klasse elektronenakzeptierender Zink(II)phthalocyanine (ZnPc) wurde entwickelt und in p‐DSSCs, die auf CuO‐Photokathoden basierten, getestet. Durch die Einstellung eines genauen Gleichgewichts zwischen dem Grenzflächen‐Ladungstransfers und der Grenzflächen‐Rekombination wurden optimierte FFs von 0.43 erreicht. Nachdem es gelang den FF in p‐DSSCs einzustellen, wandten wir uns t‐DSSCs zu, in denen zum ersten Mal CuO‐basierte p‐DSSCs und TiO2‐basierte n‐DSSCs kombiniert wurden. Als Farbstoffe dienten hierbei jeweils ZnPc und N719. Die hergestellten t‐DSSCs zeigten einen Voc von 0.86 V, der die Summe der Vocs der jeweiligen p‐ und n‐DSSCs darstellte, und einen FF von 0.63. Letztlich, ist die Effizienz der t‐DSSCs von 0.69 % nur durch ihre geringen Jscs begrenzt.
Palladium(II)‐Initiated Catellani‐Type Reactions
Authors: Cheng Hong‐Gang , Chen Shuqing , Chen Ruiming , Zhou Qianghui 
Published: December 2018

AbstractThe Catellani reaction is known as a powerful strategy for the expeditious synthesis of highly substituted arenes and benzo‐fused rings, which are usually difficult to access through traditional cross‐coupling strategies. It utilizes the synergistic interplay of palladium and norbornene catalysis to facilitate sequential ortho C−H functionalization and ipso termination of aryl halides in a single operation. In classical Catellani‐type reactions, aryl halides are mainly used as the substrates, and a Pd0 catalyst is required to initiate the reaction. Nevertheless, recent advances showcase that Catellani‐type reactions can also be initiated by a PdII catalyst with different starting materials instead of aryl halides via different reaction mechanisms and under different conditions. This emerging concept of PdII/norbornene cooperative catalysis has significantly advanced Catellani‐type reactions, thus enabling future developments of this field. In this Minireview, PdII‐initiated Catellani‐type reactions and their application in the synthesis of bioactive molecules are summarized.
Activating a Peroxo Ligand for C−O Bond Formation
Authors: del Río M. Pilar , Abril Paula , López José A. , Sodupe Mariona , Lledós Agustí , Ciriano Miguel A. , Tejel Cristina 
Published: December 2018

AbstractDioxygen activation for effective C−O bond formation in the coordination sphere of a metal is a long‐standing challenge in chemistry for which the design of catalysts for oxygenations is slowed down by the complicated, and sometimes poorly understood, mechanistic panorama. In this context, olefin–peroxide complexes could be valuable models for the study of such reactions. Herein, we showcase the isolation of rare “Ir(cod)(peroxide)” complexes (cod=1,5‐cyclooctadiene) from reactions with oxygen, and then the activation of the peroxide ligand for O−O bond cleavage and C−O bond formation by transfer of a hydrogen atom through proton transfer/electron transfer reactions to give 2‐iradaoxetane complexes and water. 2,4,6‐Trimethylphenol, 1,4‐hydroquinone, and 1,4‐cyclohexadiene were used as hydrogen atom donors. These reactions can be key steps in the oxy‐functionalization of olefins with oxygen, and they constitute a novel mechanistic pathway for iridium, whose full reaction profile is supported by DFT calculations.
Selective C−H Functionalization of Methane and Ethane by a Molecular SbV Complex
Authors: Koppaka Anjaneyulu , Park Sae Hume , Hashiguchi Brian G. , Gunsalus Niles J. , King Clinton R. , Konnick Michael M. , Ess Daniel H. , Periana Roy A. 
Published: December 2018

AbstractOwing to the strong nonpolar bonds involved, selective C−H functionalization of methane and ethane to esters remains a challenge for molecular homogeneous chemistry. We report that the computationally predicted main‐group p‐block SbV(TFA)5 complex selectively functionalizes the C−H bonds of methane and ethane to the corresponding mono and/or diol trifluoroacetate esters at 110–180 °C with yields for ethane of up to 60 % with over 90 % selectivity. Experimental and computational studies support a unique mechanism that involves SbV‐mediated C−H activation followed by functionalization of a SbV‐alkyl intermediate.
Evolution of Oxygen–Metal Electron Transfer and Metal Electronic States During Manganese Oxide Catalyzed Water Oxidation Revealed with In Situ Soft X‐Ray Spectroscopy
Authors: Tesch Marc F. , Bonke Shannon A. , Jones Travis E. , Shaker Maryam N. , Xiao Jie , Skorupska Katarzyna , Mom Rik , Melder Jens , Kurz Philipp , Knop‐Gericke Axel , Schlögl Robert , Hocking Rosalie K. , Simonov Alexandr N. 
Published: December 2018

AbstractManganese oxide (MnOx) electrocatalysts are examined herein by in situ soft X‐ray absorption spectroscopy (XAS) and resonant inelastic X‐ray scattering (RIXS) during the oxidation of water buffered by borate (pH 9.2) at potentials from 0.75 to 2.25 V vs. the reversible hydrogen electrode. Correlation of L‐edge XAS data with previous mechanistic studies indicates MnIV is the highest oxidation state involved in the catalytic mechanism. MnOx is transformed into birnessite at 1.45 V and does not undergo further structural phase changes. At potentials beyond this transformation, RIXS spectra show progressive enhancement of charge transfer transitions from oxygen to manganese. Theoretical analysis of these data indicates increased hybridization of the Mn−O orbitals and withdrawal of electron density from the O ligand shell. In situ XAS experiments at the O K‐edge provide complementary evidence for such a transition. This step is crucial for the formation of O2 from water.
A Stable Lithium–Oxygen Battery Electrolyte Based on Fully Methylated Cyclic Ether
Authors: Huang Zhimei , Zeng Haipeng , Xie Meilan , Lin Xing , Huang Zhaoming , Shen Yue , Huang Yunhui 
Published: December 2018

AbstractEther‐based electrolytes are commonly used in Li–O2 batteries (LOBs) because of their relatively high stability. But they are still prone to be attacked by superoxides or singlet oxygen via hydrogen abstract reactions, which leads to performance decaying during long‐term operation. Herein we propose a methylated cyclic ether, 2,2,4,4,5,5‐hexamethyl‐1,3‐dioxolane (HMD), as a stable electrolyte solvent for LOBs. Such a compound does not contain any hydrogen atoms on the alpha‐carbon of the ether, and thus avoids hydrogen abstraction reactions. As the result, this solvent exhibits excellent stability with the presence of superoxide or singlet oxygen. In addition the CO2 evolution during charge process is prohibited. The LOB with HMD‐based electrolyte was able to run up to 157 cycles, 4 times more than with 1,3‐dioxolane (DOL) or 1,2‐dimethoxyethane (DME) based electrolytes.