bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flexible and Ultrathin Waterproof Cellular Membranes Based on High‐Conjunction Metal‐Wrapped Polymer Nanofibers for Electromagnetic Interference Shielding
Authors: Zeng Zhihui , Jiang Fuze , Yue Yang , Han Daxin , Lin Luchan , Zhao Shanyu , Zhao Yi‐Bo , Pan Zhengyuan , Li Congju , Nyström Gustav , Wang Jing 
Published: March 2020

AbstractUltrathin, lightweight, and flexible electromagnetic interference (EMI) shielding materials are urgently demanded to address EM radiation pollution. Efficient design to utilize the shields' microstructures is crucial yet remains highly challenging for maximum EMI shielding effectiveness (SE) while minimizing material consumption. Herein, novel cellular membranes are designed based on a facile polydopamine‐assisted metal (copper or silver) deposition on electrospun polymer nanofibers. The membranes can efficiently exploit the high‐conjunction cellular structures of metal and polymer nanofibers, and their interactions for excellent electrical conductivity, mechanical flexibility, and ultrahigh EMI shielding performance. EMI SE reaches more than 53 dB in an ultra‐broadband frequency range at a membrane thickness of merely 2.5 µm and a density of 1.6 g cm−3, and an SE of 44.7 dB is accomplished at the lowest thickness of 1.2 µm. The normalized specific SE is up to 232 860 dB cm2 g−1, significantly surpassing that of other shielding materials ever reported. More, integrated functionalities are discovered in the membrane, such as antibacterial, waterproof properties, excellent air permeability, high resistance to mechanical deformations and low‐voltage uniform heating performance, offering strong potential for applications in aerospace and portable and wearable smart electronics.
Electronic Decoupling of Graphene from Copper Induced by Deposition of ZnO: A Complex Substrate/Graphene/Deposit/Environment Interaction
Authors: Morales Carlos , Urbanos Fernando J. , del Campo Adolfo , Leinen Dietmar , Granados Daniel , Rodríguez Miguel Angel , Soriano Leonardo 
Published: March 2020

AbstractThis study presents experimental data of the interactions and reactions that occur during the early stages of the growth of ZnO on graphene supported on polycrystalline copper and the subsequent changes on the electronic properties of the graphene. The combination of substrate, graphene, and intercalated species (such as oxygen and water molecules) between graphene and copper due to air exposure, together to the evaporation of metallic zinc under oxygen atmosphere, induces the electronic decoupling of the graphene from copper by the formation of a nanometric layer of copper oxide. In particular, the final stage consists in the formation of a complex interface formed by ZnO/ZnO1−x/Zn/G/Cu2O/Cu. The role of each actor is discussed in terms of a galvanic corrosion reaction of the metallic substrate where the graphene is the cathode and the initial deposition of metallic zinc accelerates the kinetics of this reaction, after which ZnO grows on the metallic zinc initially deposited. In this manner, the electronic properties of graphene can be engineered by the combination and interrelation of substrates, environment, and new‐deposited materials, revealing a more complex and realistic picture for real fabrication processes. These results may help to improve the real applicability of graphene in mass production devices.
Multifunctional Nanomaterials Modification of Cellulose Paper for Efficient Triboelectric Nanogenerators
Authors: Sriphan Saichon , Charoonsuk Thitirat , Maluangnont Tosapol , Pakawanit Phakkhananan , Rojviriya Catleya , Vittayakorn Naratip 
Published: March 2020

AbstractThere is a need to develop inexpensive, lightweight, and flexible high‐performance triboelectric nanogenerators (TENGs) from renewable resources. Here, a multifunctional cellulose filter paper (CFP)‐based TENG consisting of dielectric Ti0.8O2 nanosheets (Ti0.8O2 NSs) and conducting Ag nanoparticles (Ag NPs) is prepared by a simple dip coating method. The incorporation of dielectric Ti0.8O2 NSs onto the CFP significantly improves charge generation, while the inclusion of Ag NPs provides an electrically conductive path for charge transportation. The presence of these fillers can be deduced from XRD, SEM, EDS, X‐ray photoelectron spectroscopy, and Raman spectroscopy. Their distribution is visualized in 3D by synchrotron radiation X‐ray tomography. The present CFP‐based TENG provides an output voltage and current density of ≈42 V and ≈1 µA cm−2, respectively with the power density of ≈25 µW cm−2. It is capable of lighting up 40 light‐emitting diode bulbs and charging a 0.22 µF capacitor to 8 V in only 5 s. The developed TENG is also capable of detecting simple human motions, i.e., finger tapping, finger rubbing, and foot trampling. This work offers a facile design of low cost yet efficient paper‐based TENG by dual modification with multifunctional nanomaterials, and also demonstrates its use as a feasible power source that not only drives small electronics, but also scavenges energy from human actions.
Multipoint Nanolaser Array in an Individual Core–Shell CdS Branched Nanostructure
Authors: Hao Yan , Ding Chunjie , Lu Tianqi , Xie Lingling , Nan Pengfei , Guo Shuai , Wang Xianshuang , Li Angze , Xu Xiangjun , Zou Bingsuo , Liu Ruibin 
Published: March 2020

AbstractNanoscale laser arrays are attractive for their potential applications in highly integrated nanodevices, which are always obtained by nanowire arrays with complicated fabrication techniques. Here, a quite different nanolaser array is successfully realized based on a highly ordered core–shell CdS branched nanostructure with implanted Sn nanoparticles in junctions that split the individual multichannel nanostructures to various microcavities with effective light confinement and oscillation, thus to achieve a multipoint nanolaser array. Under the excitation of an ultraviolet laser, the strong band‐edge emission can be well reflected between Sn nanoparticles at junctions and effectively scattered into branch segments due to Sn nanoparticles existence in junctions, furthermore oscillating in various microcavities along trunks or branches to form multipoint lasing from Fabry‐Pérot (F‐P) mode with a quality factor up to 990 and the low threshold at around 3.78 MW cm−2. The corresponding fluorescent microscope images further demonstrate the formation of multipoint F‐P lasing at various segments. The theoretical simulation indicates that implanted Sn nanoparticles work as hot point to enhance the confinement of light around the Sn centers. The existence of surface plasmon from the Sn metal particles is further confirmed by the polarization dependent photoluminescence measurement. The results provide a new way to realize nanolaser arrays.
Single White‐Emitting Polymers with High Efficiency, Low Roll‐Off, and Enhanced Device Stability by Using Through‐Space Charge Transfer Polymer with Blue Delayed Fluorescence as Host for Yellow Phosphor
Authors: Hu Jun , Li Qiang , Shao Shiyang , Wang Lixiang , Jing Xiabin , Wang Fosong 
Published: March 2020

AbstractWhite‐emitting polymers hold great promise for the production of low‐cost and large‐area light sources via solution process. However, the development of efficient and stable white‐emitting polymers has been a formidable challenge yet. Here a strategy for single white‐emitting polymers is demonstrated with high efficiency, low roll‐off, and enhanced device stability by using through‐space charge transfer (TSCT) polymer with small singlet‐triplet energy splitting and blue thermally activated delayed fluorescence as host for yellow phosphor. This strategy not only combines delayed fluorescence and phosphorescence in one polymer to make full use of excitons but also enables the long‐range Förster resonant energy transfer from polymer host to phosphor for suppressing triplet quenching at high luminance, leading to state‐of‐the‐art luminous efficiency of 50.9 cd A−1 at 1000 cd m−2 (corresponding to a low roll‐off of 1.9%) for white‐emitting polymers, together with a tenfold increase in device lifetime over the control polymers based on a conventional polymer host. These results shed light on the prospect of using TSCT polymer with delayed fluorescence as host for developing efficient and stable white‐emitting polymers for solution‐processed white organic light‐emitting diodes.
Rhodium(III)‐Catalyzed Oxidative C(sp3)−H Alkenylation of 8‐Methylquinolines with Maleimides Under Aerobic Conditions
Authors: Shan Baode , Kang Baotao , Song Mingyue , Wang Rui , Chen Guozhu , Li Cuncheng , Zhao Huaiqing 
Published: March 2020

AbstractA rhodium(III)‐catalyzed C(sp3)−H alkenylation of 8‐methylquinolines with electron‐deficient maleimides has been accomplished with the combination of copper acetate, 2,2,6,6‐tetramethylpiperidine‐1‐oxyl and oxygen as the oxidant. A variety of maleimides react with various 8‐methylquinolines to furnish the corresponding alkenylated products in moderate to good yields.magnified image
The invasive plant Solidago canadensis exhibits partial local adaptation to low salinity at germination but not at later life‐history stages
Authors: Jin Huifei , Yuan Yongge , Gao Fanglei , Oduor Ayub M.O. , Li Junmin 
Published: March 2020

PremiseEvolutionary adaptation may enable plants to inhabit a broad range of environments. However, germination and early life‐history stages have seldom been considered in estimates of evolutionary adaptation. Moreover, whether soil microbial communities can influence evolutionary adaptation in plants remains little explored.MethodsWe used reciprocal transplant experiments to investigate whether two populations of an invasive plant Solidago canadensis that occur in contrasting habitats of low versus high salinity expressed adaptation to the respective salinity levels. We germinated S. canadensis seeds collected from low‐and high‐salinity habitats under low‐ and high‐salt treatments. We also raised S. canadensis seedlings from the two salinity habitats under low‐ and high‐salt treatments and in the presence versus absence of microbial communities from the two habitats.ResultsGenotypes from a low‐salinity habitat had higher germination rates under low‐salt treatment than genotypes from a high‐salinity habitat. However, both genotypes had similar germination rates under a high‐salt treatment. The two genotypes also had similar seedling survival and biomass responses to low‐ and high‐salt treatments. Nevertheless, seedling biomass was significantly higher under low salt treatment. Soil microbial communities did not influence biomass of S. canadensis under the two salt treatments.ConclusionsThe results on germination rates suggest partial local adaptation to low salinity. However, there was no evidence of local adaptation to salinity at the seedling survival and growth stages. The finding that germination and seedling biomass responded to different salt treatments suggests that the two traits are important for salt tolerance.
Playback point counts and N‐mixture models suggest higher than expected abundance of the critically endangered blond titi monkey in northeastern Brazil
Authors: Coelho Igor P. , Collins Sara J. , Santos Júnior Eduardo M. , Valença‐Montenegro Mônica M. , Jerusalinsky Leandro , Alonso André C. 
Published: March 2020

AbstractEffective management of threatened species requires accurate population size estimation and monitoring. However, reliable population size estimates are lacking for many endangered species. The critically endangered blond titi monkey (Callicebus barbarabrownae) is an endemic primate of the Caatinga biome in Northeastern Brazil. A previous assessment based on presence‐only data estimated a minimum population size of 260 mature individuals in 2,636 km2, and studies based on visual records suggested very low local relative abundance. However, this cryptic species is known to be difficult to visually detect. We played back recordings of C. barbarabrownae loud calls to count the number of responding groups in 34 sampling sites during 9 consecutive days in a 221‐km2 study area. Repeated group counts at sites were used in N‐mixture models, which account for imperfect detection, to estimate the number of groups in relation to dry forest area and distance to villages. We estimated a total of 91 groups in the study area. Considering the mean number of adults per group as three, we estimated a population of 273 adult individuals, resulting in a density of 2.3 individuals/km2 in the dry forest habitat. Detection probability was four times higher for surveys conducted between sunrise to midmorning than between midmorning to sunset. We also found that C. barbarabrownae abundance increases with increasing dry forest area and increasing distance to the nearest village, indicating the need to promote dry forest restoration in the Caatinga. As our results suggest a larger population of C. barbarabrownae than had been previously estimated for its entire distribution, our results suggest a need for similar assessments in other areas to reliably estimate the total population size. This study demonstrates how playback surveys coupled with N‐mixture models can be used to estimate population sizes of acoustically‐responsive primates, and thus contribute to more effective conservation management.
Age‐related rhesus macaque models of COVID‐19
Authors: Yu Pin , Qi Feifei , Xu Yanfeng , Li Fengdi , Liu Peipei , Liu Jiayi , Bao Linlin , Deng Wei , Gao Hong , Xiang Zhiguang , Xiao Chong , Lv Qi , Gong Shuran , Liu Jiangning , Song Zhiqi , Qu Yajin , Xue Jing , Wei Qiang , Liu Mingya , Wang Guanpeng , Wang Shunyi , Yu Haisheng , Liu Xing , Huang Baoying , Wang Wenling , Zhao Li , Wang Huijuan , Ye Fei , Zhou Weimin , Zhen Wei , Han Jun , Wu Guizhen , Jin Qi , Wang Jianwei , Tan Wenjie , Qin Chuan 
Published: March 2020

AbstractBackgroundSince December 2019, an outbreak of the Corona Virus disease 2019 (COVID‐19) caused by severe acute respiratory syndrome coronavirus (SARS‐CoV‐2) in Wuhan, China, has become a public health emergency of international concern. The high fatality of aged cases caused by SARS‐CoV‐2 was a need to explore the possible age‐related phenomena with non‐human primate models.MethodsThree 3‐5 years old and two 15 years old rhesus macaques were intratracheally infected with SARS‐CoV‐2, and then analyzed by clinical signs, viral replication, chest X‐ray, histopathological changes and immune response.ResultsViral replication of nasopharyngeal swabs, anal swabs and lung in old monkeys was more active than that in young monkeys for 14 days after SARS‐CoV‐2 challenge. Monkeys developed typical interstitial pneumonia characterized by thickened alveolar septum accompanied with inflammation and edema, notably, old monkeys exhibited diffuse severe interstitial pneumonia. Viral antigens were detected mainly in alveolar epithelial cells and macrophages.ConclusionSARS‐CoV‐2 caused more severe interstitial pneumonia in old monkeys than that in young monkeys. Rhesus macaque models infected with SARS‐CoV‐2 provided insight into the pathogenic mechanism and facilitated the development of vaccines and therapeutics against SARS‐CoV‐2 infection.
Secondary Amino Alcohols: Traceless Cleavable Linkers for Use in Affinity Capture and Release
Authors: Pomplun Sebastian , Shugrue Christopher R. , Schmitt Adeline M. , Schissel Carly K. , Farquhar Charlotte E. , Pentelute Bradley L. 
Published: March 2020

AbstractCapture and release of peptides is often a critical operation in the pathway to discovering materials with novel functions. However, the best methods for efficient capture impede facile release. To overcome this challenge, we report linkers based on secondary amino alcohols for the release of peptides after capture. These amino alcohols are based on serine (seramox) or isoserine (isoseramox) and can be incorporated into peptides during solid‐phase peptide synthesis through reductive amination. Both linkers are quantitatively cleaved within minutes under NaIO4 treatment. Cleavage of isoseramox produced a native peptide N‐terminus. This linker also showed broad substrate compatibility; incorporation into a synthetic peptide library resulted in the identification of all sequences by nanoLC‐MS/MS. The linkers are cell compatible; a cell‐penetrating peptide that contained this linker was efficiently captured and identified after uptake into cells. These findings suggest that such secondary amino alcohol based linkers might be suitable tools for peptide‐discovery platforms.
Distance Synergy of MoS2‐Confined Rhodium Atoms for Highly Efficient Hydrogen Evolution
Authors: Meng Xiangyu , Ma Chao , Jiang Luozhen , Si Rui , Meng Xianguang , Tu Yunchuan , Yu Liang , Bao Xinhe , Deng Dehui 
Published: March 2020

AbstractPerturbing the electronic structure of the MoS2 basal plane by confining heteroatoms offers the opportunity to trigger in‐plane activity for the hydrogen evolution reaction (HER). The key challenge consists of inducing the optimum HER activity by controlling the type and distribution of confined atoms. A distance synergy of MoS2‐confined single‐atom rhodium is presented, leading to an ultra‐high HER activity at the in‐plane S sites adjacent to the rhodium. By optimizing the distance between the confined Rh atoms, an ultra‐low overpotential of 67 mV is achieved at a current density of 10 mA cm−2 in acidic solution. Experiments and first‐principles calculations demonstrate a unique distance synergy between the confined rhodium atoms in tuning the reactivity of neighboring in‐plane S atoms, which presents a volcanic trend with the inter‐rhodium distance. This study provides a new strategy to tailor the activity of MoS2 surface via modulating the distance between confined single atoms.
Organobor‐Funktionalisierung ermöglicht die hierarchische Aggregation gigantischer Polyoxometallat‐Nanokapseln
Authors: Li Shujun , Zhou Yanfang , Ma Nana , Zhang Jie , Zheng Zhiping , Streb Carsten , Chen Xuenian 
Published: March 2020

AbstractDie Aggregation molekularer Metalloxide in größere Superstrukturen kann die Lücke zwischen molekularen Verbindungen und Festkörperstrukturen überbrücken. Hier berichten wir über die Funktionalisierung von Polyoxowolframaten mit Organobor‐Substituenten, was zur Bildung gigantischer Polyoxometallat‐Nanokapseln mit Dimensionen von bis zu vier Nanometern führt. Ein Schlüssel‐Schloss‐Mechanismus erlaubt das regiospezifische Verankern aromatischer Boronsäuren an Metall‐funktionalisierten Dawson‐Anionen [M3P2W15O62]9− (M=TaV oder NbV). Dies führt zu neuartigen Nanokapseln bestehend aus bis zu 12 POM‐Enheiten. Experimentelle und theoretische Studien geben erste Einblicke in die Funktion der Organobor‐Einheiten sowie der metallfunktionalisierten POMs für die Aggregation der Kapseln. Die Studie legt den Grundstein für die Entwicklung organo‐POM‐basierter funktioneller Nanostrukturen.
Enhanced CO2 Electroreduction on Neighboring Zn/Co Monomers by Electronic Effect
Authors: Zhu Wenjin , Zhang Lei , Liu Sihang , Li Ang , Yuan Xintong , Hu Congling , Zhang Gong , Deng Wanyu , Zang Ketao , Luo Jun , Zhu Yuanmin , Gu Meng , Zhao Zhi‐Jian , Gong Jinlong 
Published: March 2020

AbstractIt is of great significance to reveal the detailed mechanism of neighboring effects between monomers, as they could not only affect the intermediate bonding but also change the reaction pathway. This paper describes the electronic effect between neighboring Zn/Co monomers effectively promoting CO2 electroreduction to CO. Zn and Co atoms coordinated on N doped carbon (ZnCoNC) show a CO faradaic efficiency of 93.2 % at −0.5 V versus RHE during a 30‐hours test. Extended X‐ray absorption fine structure measurements (EXAFS) indicated no direct metal–metal bonding and X‐ray absorption near‐edge structure (XANES) showed the electronic effect between Zn/Co monomers. In situ attenuated total reflection‐infrared spectroscopy (ATR‐IR) and density functional theory (DFT) calculations further revealed that the electronic effect between Zn/Co enhanced the *COOH intermediate bonding on Zn sites and thus promoted CO production. This work could act as a promising way to reveal the mechanism of neighboring monomers and to influence catalysis.
Efficient Hydrogen Oxidation Catalyzed by Strain‐Engineered Nickel Nanoparticles
Authors: Ni Weiyan , Wang Teng , Schouwink Pascal Alexander , Chuang Yu‐Chun , Chen Hao Ming , Hu Xile 
Published: March 2020

AbstractThe hydroxide‐exchange membrane fuel cell (HEMFC) is a promising energy conversion device. However, the development of HEMFC is hampered by the lack of platinum‐group‐metal‐free (PGM‐free) electrocatalysts for the hydrogen oxidation reaction (HOR). Now, a Ni catalyst is reported that exhibits the highest mass activity in HOR for a PGM‐free catalyst as well as excellent activity in the hydrogen evolution reaction (HER). This catalyst, Ni‐H2‐2 %, was optimized through pyrolysis of a Ni‐containing metal‐organic framework precursor under a mixed N2/H2 atmosphere, which yielded carbon‐supported Ni nanoparticles with different levels of strains. The Ni‐H2‐2 % catalyst has an optimal level of strain, which leads to an optimal hydrogen binding energy and a high number of active sites.
Label‐Free Nanoimaging of Neuromelanin in the Brain by Soft X‐ray Spectromicroscopy
Authors: Brooks Jake , Everett James , Lermyte Frederik , Tjhin Vindy Tjendana , Banerjee Samya , O'Connor Peter B. , Morris Christopher M. , Sadler Peter J. , Telling Neil D. , Collingwood Joanna F. 
Published: March 2020

AbstractA hallmark of Parkinson's disease is the death of neuromelanin‐pigmented neurons, but the role of neuromelanin is unclear. The in situ characterization of neuromelanin remains dependent on detectable pigmentation, rather than direct quantification of neuromelanin. We show that direct, label‐free nanoscale visualization of neuromelanin and associated metal ions in human brain tissue can be achieved using synchrotron scanning transmission x‐ray microscopy (STXM), through a characteristic feature in the neuromelanin x‐ray absorption spectrum at 287.4 eV that is also present in iron‐free and iron‐laden synthetic neuromelanin. This is confirmed in consecutive brain sections by correlating STXM neuromelanin imaging with silver nitrate‐stained neuromelanin. Analysis suggests that the 1s–σ* (C−S) transition in benzothiazine groups accounts for this feature. This method illustrates the wider potential of STXM as a label‐free spectromicroscopy technique applicable to both organic and inorganic materials.
Catalytic Hydroetherification of Unactivated Alkenes Enabled by Proton‐Coupled Electron Transfer
Authors: Tsui Elaine , Metrano Anthony J. , Tsuchiya Yuto , Knowles Robert R. 
Published: March 2020

AbstractWe report a catalytic, light‐driven method for the intramolecular hydroetherification of unactivated alkenols to furnish cyclic ether products. These reactions occur under visible‐light irradiation in the presence of an IrIII‐based photoredox catalyst, a Brønsted base catalyst, and a hydrogen‐atom transfer (HAT) co‐catalyst. Reactive alkoxy radicals are proposed as key intermediates, generated by direct homolytic activation of alcohol O−H bonds through a proton‐coupled electron‐transfer mechanism. This method exhibits a broad substrate scope and high functional‐group tolerance, and it accommodates a diverse range of alkene substitution patterns. Results demonstrating the extension of this catalytic system to carboetherification reactions are also presented.