bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cobalt(II)‐Catalyzed Cross‐Dehydrogenative Coupling Reaction of Benzamides with Alcohols to Build C‐O Bond
Authors: Liu Sheng‐Kang , Cui Xin‐Feng , Liu Xing‐Xing , Ma Hao‐Jie , Wei Dai‐Dong , Luo Xin‐Liang , Huang Guo‐Sheng 
Published: April 2018

AbstractA concise and efficient protocol for ortho‐C−H alkoxylation of benzamides was developed via Co(II)‐catalyzed cross‐dehydrogenative coupling (CDC) reaction with alcohols. The reaction employs a Ag2O oxidant, a NaOAc base and alcohols solvent required as the alkoxylation source under N2 atmosphere. The method shows excellent functional group tolerance and highly regioselectivity, which provides a facile pathway for the ortho‐alkoxylation of benzamides.
Simultaneous Enhancement of the Performance and Stability of MnO2 Based Lithium Ion Battery Anodes by Compositing with Fluorine Terminated Functionalized Graphene Oxide
Authors: Ji Seulgi , Ju Ji Young , Kim Seong Ku , Kim Jin Kyu , Song Wooseok , Myung Sung , Lim Jongsun , Kang Yongku , An Ki‐Seok , Choi Sungho , Lee Sun Sook 
Published: April 2018

AbstractMetal oxide based anodes for lithium ion batteries should theoretically exhibit high specific capacities, but their disappointing experimentally measured capacities and cycle stabilities inhibit their usages in the commercial and industrial level. Here, we propose a simple method to process the MnO2/2,2,3,3,4,4,4‐Heptafluorobutylamine‐functionalized‐graphene‐oxide(HFBA‐fGO) composite anode, in which HFBA‐fGO is composited with the MnO2 based anode to simultaneously enhance the specific capacity to reach the theoretical capacity of MnO2 and improve the cyclic stability significantly. In fact, the MnO2/HFBA‐fGO composite anode exhibits high performance with specific capacity of 1030 mAhg−1 under 100 mAg−1 and stable cyclic performance at least up to 200 cycles of repeated charging and discharging even at a high rate of 1 A g−1. A detailed analysis of the enhanced cyclic stability of the composite anode is performed through the investigation of the electrode‐electrolyte interfaces using the electrochemical impedance spectroscopy and cyclic voltammetry. Such results were possible because of the significantly suppressed irreversible formation of the surface passivation layer caused by the fluorine‐rich terminal groups of the HFBA‐fGO, which leads to enhanced cyclic stability. We believe that this method should be effective even for other various metal‐oxide anodes besides MnO2 as well, which certainly broadens the potential use of HFBA‐fGO.
Interfacial Engineering of Hierarchical Transition Metal Oxide Heterostructures for Highly Sensitive Sensing of Hydrogen Peroxide
Authors: Zhang Wen , Fan Guozheng , Yi Huan , Jia Gan , Li Zhaosheng , Yuan Chunwei , Bai Yunfei , Fu Degang 
Published: April 2018

AbstractHydrogen peroxide (H2O2) is a major messenger molecule in cellular signal transduction. Direct detection of H2O2 in complex environments provides the capability to illuminate its various biological functions. With this in mind, a novel electrochemical approach is here proposed by integrating a series of CoO nanostructures on CuO backbone at electrode interfaces. High‐resolution transmission electron microscopy (HRTEM), X‐ray diffraction, and X‐ray photoelectron spectroscopy demonstrate successful formation of core–shell CuO–CoO hetero‐nanostructures. Theoretical calculations further confirm energy‐favorable adsorption of H2O2 on surface sites of CuO–CoO heterostructures. Contributing to the efficient electron transfer path and enhanced capture of H2O2 in the unique leaf‐like CuO–CoO hierarchical 3D interface, an optimal biosensor‐based CuO–CoO‐2.5 h electrode exhibits an ultrahigh sensitivity (6349 µA m m−1 cm−2), excellent selectivity, and a wide detection range for H2O2, and is capable of monitoring endogenous H2O2 derived from human lung carcinoma cells A549. The synergistic effects for enhanced H2O2 adsorption in integrated CuO–CoO nanostructures and performance of the sensor suggest a potential for exploring pathological and physiological roles of reactive oxygen species like H2O2 in biological systems.
Sb‐Doped SnO2 Nanorods Underlayer Effect to the α‐Fe2O3 Nanorods Sheathed with TiO2 for Enhanced Photoelectrochemical Water Splitting
Authors: Han Hyungkyu , Kment Stepan , Karlicky Frantisek , Wang Lei , Naldoni Alberto , Schmuki Patrik , Zboril Radek 
Published: April 2018

AbstractHere, a Sb‐doped SnO2 (ATO) nanorod underneath an α‐Fe2O3 nanorod sheathed with TiO2 for photoelectrochemical (PEC) water splitting is reported. The experimental results, corroborated with theoretical analysis, demonstrate that the ATO nanorod underlayer effect on the α‐Fe2O3 nanorod sheathed with TiO2 enhances the PEC water splitting performance. The growth of the well‐defined ATO nanorods is reported as a conductive underlayer to improve α‐Fe2O3 PEC water oxidation performance. The α‐Fe2O3 nanorods grown on the ATO nanorods exhibit improved performance for PEC water oxidation compared to α‐Fe2O3 grown on flat fluorine‐doped tin oxide glass. Furthermore, a simple and facile TiCl4 chemical treatment further introduces TiO2 passivation layer formation on the α‐Fe2O3 to reduce surface recombination. As a result, these unique nanostructures show dramatically improved photocurrent density (139% higher than that of the pure hematite nanorods).
Lead‐Free Perovskite Nanowire‐Employed Piezopolymer for Highly Efficient Flexible Nanocomposite Energy Harvester
Authors: Jeong Chang Kyu , Baek Changyeon , Kingon Angus I. , Park Kwi‐Il , Kim Seung‐Hyun 
Published: April 2018

AbstractIn the past two decades, mechanical energy harvesting technologies have been developed in various ways to support or power small‐scale electronics. Nevertheless, the strategy for enhancing current and charge performance of flexible piezoelectric energy harvesters using a simple and cost‐effective process is still a challenging issue. Herein, a 1D–3D (1‐3) fully piezoelectric nanocomposite is developed using perovskite BaTiO3 (BT) nanowire (NW)‐employed poly(vinylidene fluoride‐co‐trifluoroethylene) (P(VDF‐TrFE)) for a high‐performance hybrid nanocomposite generator (hNCG) device. The harvested output of the flexible hNCG reaches up to ≈14 V and ≈4 µA, which is higher than the current levels of even previous piezoceramic film‐based flexible energy harvesters. Finite element analysis method simulations study that the outstanding performance of hNCG devices attributes to not only the piezoelectric synergy of well‐controlled BT NWs and within P(VDF‐TrFE) matrix, but also the effective stress transferability of piezopolymer. As a proof of concept, the flexible hNCG is directly attached to a hand to scavenge energy using a human motion in various biomechanical frequencies for self‐powered wearable patch device applications. This research can pave the way for a new approach to high‐performance wearable and biocompatible self‐sufficient electronics.
Highly Porous Mn3O4 Micro/Nanocuboids with In Situ Coated Carbon as Advanced Anode Material for Lithium‐Ion Batteries
Authors: Jiang Yao , Yue Ji‐Li , Guo Qiubo , Xia Qiuying , Zhou Chong , Feng Tao , Xu Jing , Xia Hui 
Published: April 2018

AbstractThe electrochemical performance of most transition metal oxides based on the conversion mechanism is greatly restricted by inferior cycling stability, rate capability, high overpotential induced by the serious irreversible reactions, low electrical conductivity, and poor ion diffusivity. To mitigate these problems, highly porous Mn3O4 micro/nanocuboids with in situ formed carbon matrix (denoted as Mn3O4@C micro/nanocuboids) are designed and synthesized via a one‐pot hydrothermal method, in which glucose plays the roles of a reductive agent and a carbon source simultaneously. The carbon content, particle size, and pore structure in the composite can be facilely controlled, resulting in continuous carbon matrix with abundant pores in the cuboids. The as‐fabricated Mn3O4@C micro/nanocuboids exhibit large reversible specific capacity (879 mAh g−1 at the current density of 100 mA g−1) as well as outstanding cycling stability (86% capacity retention after 500 cycles) and rate capability, making it a potential candidate as anode material for lithium‐ion batteries. Moreover, this facile and effective synthetic strategy can be further explored as a universal approach for the synthesis of other hierarchical transition metal oxides and carbon hybrids with subtle structure engineering.
Strongly Coupled Carbon Nanosheets/Molybdenum Carbide Nanocluster Hollow Nanospheres for High‐Performance Aprotic Li–O2 Battery
Authors: Xing Yi , Yang Yong , Chen Renjie , Luo Mingchuan , Chen Nan , Ye Yusheng , Qian Ji , Li Li , Wu Feng , Guo Shaojun 
Published: April 2018

AbstractA highly efficient oxygen electrode is indispensable for achieving high‐performance aprotic lithium–O2 batteries. Herein, it is demonstrated that strongly coupled carbon nanosheets/molybdenum carbide (α‐MoC1−x) nanocluster hierarchical hybrid hollow spheres (denoted as MoC1−x/HSC) can work well as cathode for boosting the performance of lithium–O2 batteries. The important feature of MoC1−x/HSC is that the α‐MoC1−x nanoclusters, uniformly incorporated into carbon nanosheets, can not only effectively prevent the nanoclusters from agglomeration, but also help enhance the interaction between the nanoclusters and the conductive substrate during the charge and discharge process. As a consequence, the MoC1−x/HSC shows significantly improved electrocatalytic performance in an aprotic Li–O2 battery with greatly reduced charge and discharge overpotentials and long cycle stability. The ex situ scanning electron microscopy, X‐ray diffraction, and X‐ray photoelectron spectroscopy studies reveal that the mechanism for the high‐performance Li–O2 battery using MoC1−x/HSC as cathode is that the incorporated molybdenum carbide nanoclusters can make oxygen reduction on their surfaces easy, and finally form amorphous film‐like Li‐deficient Li2O2 with the ability to decompose at a low potential. To the best of knowledge, the MoC1−x/HSC of this paper is among the best cathode materials for lithium–O2 batteries reported to date.
Clay Nanoparticles Elicit Long‐Term Immune Responses by Forming Biodegradable Depots for Sustained Antigen Stimulation
Authors: Chen Weiyu , Zuo Huali , Li Bei , Duan Chengcheng , Rolfe Barbara , Zhang Bing , Mahony Timothy J. , Xu Zhi Ping 
Published: April 2018

AbstractNanomaterials have been widely tested as new generation vaccine adjuvants, but few evoke efficient immunoreactions. Clay nanoparticles, for example, layered double hydroxide (LDH) and hectorite (HEC) nanoparticles, have shown their potent adjuvanticity in generating effective and durable immune responses. However, the mechanism by which clay nanoadjuvants stimulate the immune system is not well understood. Here, it is demonstrated that LDH and HEC–antigen complexes form loose agglomerates in culture medium/serum. They also form nodules with loose structures in tissue after subcutaneous injection, where they act as a depot for up to 35 d. More importantly, clay nanoparticles actively and continuously recruit immune cells into the depot for up to one month, and stimulate stronger immune responses than FDA‐approved adjuvants, Alum and QuilA. Sustained antigen release is also observed in clay nanoparticle depots, with 50–60% antigen released after 35 d. In contrast, Alum–antigen complexes show minimal antigen release from the depot. Importantly, LDH and HEC are more effective than QuilA and Alum in promoting memory T‐cell proliferation. These findings suggest that both clay nanoadjuvants can serve as active vaccine platforms for sustained and potent immune responses.
A Flexible Caterpillar‐Like Gold Nanoparticle Assemblies with Ultrasmall Nanogaps for Enhanced Dual‐Modal Imaging and Photothermal Therapy
Authors: Xia Yuanzhi , Ma Xuehua , Gao Junhua , Chen Guoxin , Li Zihou , Wu Xiaoxia , Yu Zhangsen , Xing Jie , Sun Li , Ruan Huimin , Luo Lijia , Xiang Lingchao , Dong Chen , Ren Wenzhi , Shen Zheyu , Wu Aiguo 
Published: April 2018

AbstractGold nanoparticle (AuNP) assemblies (GNAs) have attracted attention since enhanced coupling plasmonic resonance (CPR) emerged in the nanogap between coupling AuNPs. For one dimensional GNAs (1D‐GNAs), most CPR from the nanogaps could be easily activated by electromagnetic waves and generate drastically enhanced CPR because the nanogaps between coupling AuNPs are linearly distributed in the 1D‐GNAs. The reported studies focus on the synthesis of 1D‐GNAs and fundamental exploration of CPR. There are still problems which impede further applications in nanomedicine, such as big size (>500 nm), poor water solubility, and/or poor stability. In this study, a kind of 1D flexible caterpillar‐like GNAs (CL‐GNAs) with ultrasmall nanogaps, good water solubility, and good stability is developed. The CL‐GNAs have a flexible structure that can randomly move to change their morphology, which is rarely reported. Numerous ultrasmall nanogaps (<1 nm) are linearly distributed along the structure of CL‐GNAs and generate enhanced CPR. The toxicity assessments in vitro and vivo respectively demonstrate that CL‐GNAs have a low cytotoxicity and good biocompatibility. The CL‐GNAs can be used as an efficient photothermal agent for photothermal therapy, a probe for Raman imaging and photothermal imaging.
Nanowire‐Intensified Metal‐Enhanced Fluorescence in Hybrid Polymer‐Plasmonic Electrospun Filaments
Authors: Camposeo Andrea , Jurga Radoslaw , Moffa Maria , Portone Alberto , Cardarelli Francesco , Della Sala Fabio , Ciracì Cristian , Pisignano Dario 
Published: April 2018

AbstractHybrid polymer‐plasmonic nanostructures might combine high enhancement of localized fields from metal nanoparticles with light confinement and long‐range transport in subwavelength dielectric structures. Here, the complex behavior of fluorophores coupling to Au nanoparticles within polymer nanowires, which features localized metal‐enhanced fluorescence (MEF) with unique characteristics compared to conventional structures, is reported. The intensification effect when the particle is placed in the organic filaments is remarkably higher with respect to thin films of comparable thickness, thus highlighting a specific, nanowire‐related enhancement of MEF effects. A dependence on the confinement volume in the dielectric nanowire is also indicated, with MEF significantly increasing upon reduction of the wire diameter. These findings are rationalized by finite element simulations, predicting a position‐dependent enhancement of the quantum yield of fluorophores embedded in the fibers. Calculation of the ensemble‐averaged fluorescence enhancement unveils the possibility of strongly enhancing the overall emission intensity for structures with size twice the diameter of the embedded metal particles. These new, hybrid fluorescent systems with localized enhanced emission, and the general nanowire‐enhanced MEF effects associated to them, are highly relevant for developing nanoscale light‐emitting devices with high efficiency and intercoupled through nanofiber networks, highly sensitive optical sensors, and novel laser architectures.
High‐Temperature Particulate Matter Filtration with Resilient Yttria‐Stabilized ZrO2 Nanofiber Sponge
Authors: Wang Haolun , Lin Sen , Yang Shen , Yang Xudong , Song Jianan , Wang Dong , Wang Haiyang , Liu Zhenglian , Li Bo , Fang Minghao , Wang Ning , Wu Hui 
Published: April 2018

AbstractParticulate matter (PM) is a major air pollutant in many regions, jeopardizing ecosystems and public health. Filtration at pollutant source is one of the most important ways to protect the environment, however, considering the high‐temperature exhaust gas emissions, effective removal of PM and related pollutants from their sources remains a major challenge. In this study, a resilient, heat‐resisting, and high‐efficiency PM filter based on yttria‐stabilized ZrO2 (YSZ) nanofiber sponge produced with a scalable solution blow spinning process is reported. The porous 3D sponge composed of YSZ nanofibers is lightweight (density of 20 mg cm−3) and resilient at both room temperature and high temperatures. At room‐temperature conditions, the YSZ nanofiber sponge exhibits 99.4% filtration efficiency for aerosol particles with size in the range of 20–600 nm, associated with a low pressure drop of only 57 Pa under an airflow velocity of 4.8 cm s−1. At a high temperature of 750 °C, the ceramic sponge maintains a high filtration efficiency of 99.97% for PM0.3–2.5 under a high airflow velocity of 10 cm s−1. A practical vehicle exhaust filter to capture particles with filtration efficiency of >98.3% is also assembled. Hence, the YSZ nanofiber sponge has enormous potential to be applied in industry.
Distinguishable Detection of Ultraviolet, Visible, and Infrared Spectrum with High‐Responsivity Perovskite‐Based Flexible Photosensors
Authors: Wu Xiaohan , Zhou Bilei , Zhou Jiachen , Chen Yantao , Chu Yingli , Huang Jia 
Published: April 2018

AbstractDistinguishable detection of the ultraviolet, visible, and infrared spectrum is promising and significant for the super visual system of artificial intelligences. However, it is challenging to provide a photosensor with such broad spectral response ability. In this work, the ultraviolet, visible, and infrared spectrum is distinguished by developing serial photosensors based on perovskite/carbon nanotube hybrids. Oraganolead halide perovskites (CH3NH3PbX3) possess remarkable optoelectronic properties and tunable optical band gaps by changing the halogens, and integration with single‐walled carbon nanotubes can further improve their photoresponsivities. The CH3NH3PbCl3‐based photosensor shows a responsivity up to 105 A W−1 to ultraviolet and no obvious response to visible light, which is superior to that of most ultraviolet sensors. The CH3NH3PbBr3‐based photosensor exhibits a high responsivity to visible light. Serial devices of the two hybrid photosensors with comparable electric and sensory performances can distinguish the spectrum of ultraviolet, visible, and infrared even with varying light intensities. The photosensors also demonstrate excellent mechanical flexibility and bending stability. By taking full advantages of the oraganolead halide perovskites, this work provides flexible high‐responsivity photosensors specialized for ultraviolet, and gives a simple strategy for distinguishable detection of ultraviolet, visible, and infrared spectrum based on the serial flexible photosensors.
A 360° view of circular RNAs: From biogenesis to functions
Authors: Wilusz Jeremy E. 
Published: April 2018

The first circular RNA (circRNA) was identified more than 40 years ago, but it was only recently appreciated that circRNAs are common outputs of many eukaryotic protein‐coding genes. Some circRNAs accumulate to higher levels than their associated linear mRNAs, especially in the nervous system, and have clear regulatory functions that result in organismal phenotypes. The pre‐mRNA splicing machinery generates circRNAs via backsplicing reactions, which are often facilitated by intronic repeat sequences that base pair to one another and bring the intervening splice sites into close proximity. When spliceosomal components are limiting, circRNAs can become the preferred gene output, and backsplicing reactions are further controlled by exon skipping events and the combinatorial action of RNA binding proteins. This allows circRNAs to be expressed in a tissue‐ and stage‐specific manner. Once generated, circRNAs are highly stable transcripts that often accumulate in the cytoplasm. The functions of most circRNAs remain unknown, but some can regulate the activities of microRNAs or be translated to produce proteins. Circular RNAs can further interface with the immune system as well as control gene expression events in the nucleus, including alternative splicing decisions. Circular RNAs thus represent a large class of RNA molecules that are tightly regulated, and it is becoming increasingly clear that they likely impact many biological processes.This article is categorized under:
RNA Processing > Splicing Mechanisms
RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems
RNA Evolution and Genomics > RNA and Ribonucleoprotein Evolution
RNA Evolution and Genomics > Computational Analyses of RNA
Seasonal changes of mercury speciation in the coastal sediments
Authors: Bełdowski Jacek , Szubska Marta , Bełdowska Magdalena , Jankowska Katarzyna , Kotlarska Ewa , Graca Bożena 
Published: April 2018

Abstract
Purpose
Mercury speciation in sediments is linked to environmental conditions and processes. Domination of particular mercury species depends on its source, displays considerable seasonal behavior, and may be further modified due to oxygen levels, icing conditions, or the input of fresh organic matter. The purpose of this study was to examine the coastal area of the Gulf of Gdańsk in terms of mercury contamination and the influence of seasonal environmental changes on its speciation.

Materials and methods
In three highly dynamic coastal sites, mercury speciation in sediments was studied in relation to other environmental parameters (redox conditions, organic matter concentration, bacteria abundance, etc.). Sediment and water samples were collected monthly during a 3-year study. Sequential extraction of sediments was used for identification of four inorganic mercury species: dissolved, bound with fulvic and humic acids, mercury sulfide, and residual fraction. Cold vapor atomic fluorescence spectrometry (CV-AFS) was used for extracts and liquid sample analysis. Total mercury in sediments was measured with atomic absorption spectrometry (AAS). Changes in salinity were analyzed by measurements of chloride and sulfate ion concentrations using ion chromatography. Bacteria number and biomass were measured by direct counting using epifluorescence microscopy.

Results and discussion
Seasonal changes in mercury speciation were observed at all sites and attributed to different processes. Labile mercury fraction contribution varied from 0 to 80%. The speciation patterns varied locally as the stations selected for the study are diversified in terms of anthropogenic impact, water dynamics, and output from land. Mercury concentrations at all stations fluctuated during phytoplankton blooms, icing of marine waters, precipitation, or increased surface runoff from the land. In this local scale, the global climate changes are visible already as environmental conditions in studied area changed in comparison to elder research.

Conclusions
Obtained results suggest that although mercury emissions to the environment have decreased in recent years, local weather conditions, which may be intensified by climate change, seriously affect the bioavailability of past mercury deposits in coastal sediments.
0.1°C accuracy ICO temperature sensor with segmentation algorithm
Authors: Li Jing , Zhou Pengfei , Hu Yuanbin , Wang Zhaochi , Wei Yi , Li Chengze , Wu Kejun , Ning Ning 
Published: April 2018

A real‐time temperature detection circuit with 0.1°C accuracy is presented. The temperature sensor is composed by a current controlled oscillator (ICO). Its oscillating frequency is proportional to the temperature but independent with the power supply. The frequency change will be digitised by a counter and thus realise the temperature detection. The detection accuracy is limited by the linearity of ICO. In order to improve temperature detection accuracy, a temperature segmentation algorithm is proposed. The temperature sensor is implemented with 0.18 μm CMOS technology and the core area is 0.023 mm2. The power consumption of the proposed sensor is 0.3 mW with 1.8 V supply. Experimental results show that this sensor can detect the temperature from −40 to 125°C with 0.1°C accuracy and the detection error is within ±0.8°C.