bluuebunny/crossref_metadata_2025_split huggingface dataset:
Facile Fabrication of Highly Dispersed Pd@Ag Core–Shell Nanoparticles Embedded in Spirulina platensis by Electroless Deposition and Their Catalytic Properties
Authors: Sun Lili , Zhang Deyuan , Sun Yanming , Wang Suying , Cai Jun 
Published: April 2018

AbstractMicroorganisms are widely used as the biotemplates for producing micro/nanomaterials owing to their unique features, such as exquisite morphology, renewable, and environmentally friendly. However, mass intracellular synthesis of uniformly dispersed nanoparticles (NPs) inside microorganisms is still challenging, especially in a predictable and controllable manner. Here, a facile and efficiency strategy is proposed to controllably produce highly dispersed and surfactant‐free Pd@Ag core–shell NPs within the Spirulina platensis (Sp.) cells. In this approach, the Sp. cells' permeability is enhanced by the hydrochloric acid treatment first, which enables the Pd NPs penetrate the cell envelope and distribute uniformly inside the cells, and then they can work as the catalytic seeds for the following electroless silver deposition, resulting in the intracellular fabrication of Pd@Ag core–shell NPs with no agglomeration. The Pd@Ag NPs show excellent catalytic activity (turnover frequency is up to 2893 h−1 for the 6.32 nm Pd@Ag NPs), good stability, and recyclability toward the 4‐nitrophenol reductions. The excellent properties are attributed to the asymmetrical core–shell structure, small size, and good dispersion of Pd@Ag NPs. Due to its facility, cost‐effectiveness, and versatility, this method can be expanded to other microorganisms, so it opens tremendous opportunities for various metallic nanoparticles intracellular synthesis as well as the practical application.
A Self‐Powered Brain‐Linked Vision Electronic‐Skin Based on Triboelectric‐Photodetecing Pixel‐Addressable Matrix for Visual‐Image Recognition and Behavior Intervention
Authors: Dai Yitong , Fu Yongming , Zeng Hui , Xing Lili , Zhang Yan , Zhan Yang , Xue Xinyu 
Published: April 2018

AbstractA new self‐powered brain‐linked vision electronic‐skin (e‐skin) for mimicking retina is realized from Polypyrrole/Polydimethysiloxane (Ppy/PDMS) triboelectric‐photodetecting pixel‐addressable matrix. The e‐skin can be driven by human motion, so no external electricity power is needed in both photodetecting and signal transmitting processes. The triboelectric output is significantly dependent on the photo illumination, which can act as visual bionic electric impulse. Taking blue illumination (405 nm) as an example, as the e‐skin is exposed to 100 µW cm−2 illumination, the output current decreases from 7.5 to 4.9 nA, and the photosensitivity is 34.7. And the photosensitivity of the e‐skin keeps stable with different bending angles and force. The e‐skin is flexible enough to combine with human body and can be driven by blinking eyes to detect UV illumination. In addition, the 4 × 4 photodetecting unit matrix in the e‐skin can map single‐point and multipoint illumination‐stimuli (visual‐image recognition) via the multichannel data acquisition method. Furthermore, the e‐skin can directly transmit photodetecting signals into mouse brain for participating in the perception and behavior intervention. This new self‐powered perception device can lower down the production cost of traditional complex sensory‐substitution system, and can be easily extended to various brain–machine interaction applications.
Improved Molecular Stacking and Data‐Storage Performance of Pyridine‐ and Pyrimidine‐Substituted Small Molecules
Authors: Zhang Qijian , Wang Gang , Li Hui , Zhu Fengjuan , Li Hua , Lu Jianmei 
Published: April 2018

AbstractThe molecular stacking in film state has been confirmed to have an important influence on electronic properties of organic semiconductors. Thus, how to improve the molecular stacking and the corresponding device performance through molecular design is a difficult question that researches want to figure out. In this work, three small molecules with different bridge‐spacers, phenyl ring, pyridine, and pyrimidine, are designed to study the effect of nitrogen amount on molecular stacking in film state. The infrared spectroscopy in solution and film states are first measured to consider the hydrogen bond between the neighboring molecules, which can induce ordered molecular stacking through intermolecular interaction. X‐ray diffraction, atomic force microscopy, and grazing incidence small angle X‐ray scattering measurements confirm the ordered molecular stacking and crystalline orientation of nitrogenous heterocycles substituted molecules in film state. Additionally, nitrogenous heterocycles substituted molecules exhibit the excellent ternary data‐storage properties with low threshold voltage and high current ratio. This result presents the strategy for designing novel small molecules with excellent molecular stacking in film state.
Interfacial Self‐Assembly of Amphiphilic Dual Temperature Responsive Actuating Janus Particles
Authors: Hessberger Tristan , Braun Lukas B. , Zentel Rudolf 
Published: April 2018

AbstractAmphiphilic Janus particles feature the combination of two different functional materials in one single colloid, as well as the possibility of self‐assembly at interfaces into complex superstructures. In this article, the self‐assembly of dual temperature responsive amphiphilic Janus particles at liquid–liquid interfaces and their subsequent conversion into an actuating layer‐shaped surface are presented. These microparticles are produced in a capillaries based continuous flow microfluidic device by photoinitiated radical polymerization. The hydrophobic part of the Janus particles contains a liquid crystalline elastomer (LCE), which performs a strong actuation up to 95% during the nematic–isotropic phase transition. The other side consists of a p(NIPAAm) hydrogel, which features volumetric expansions up to 280% below the lower critical solution temperature. A multistep molding process is developed to uniformly align the Janus particles at a toluene/water boundary surface and to embed the particles into a hydrogel matrix. A particle covered hydrogel layer is obtained, which features a collective actuation of the rod‐like LCE parts on the surface and a bundling of the resulting forces during the phase transition.
Chirality Dependent Charge Transfer Rate in Oligopeptides
Authors: Tassinari Francesco , Jayarathna Dilhara R. , Kantor‐Uriel Nirit , Davis Kathryn L. , Varade Vaibhav , Achim Catalina , Naaman Ron 
Published: April 2018

AbstractIt is shown that “spontaneous magnetization” occurs when chiral oligopeptides are attached to ferrocene and are self‐assembled on a gold substrate. As a result, the electron transfer, measured by electrochemistry, shows asymmetry in the reduction and oxidation rate constants; this asymmetry is reversed between the two enantiomers. The results can be explained by the chiral induced spin selectivity of the electron transfer. The measured magnetization shows high anisotropy and the “easy axis” of magnetization is along the molecular axis.
Glassomer—Processing Fused Silica Glass Like a Polymer
Authors: Kotz Frederik , Schneider Norbert , Striegel Andreas , Wolfschläger Andre , Keller Nico , Worgull Matthias , Bauer Werner , Schild Dieter , Milich Marcel , Greiner Christian , Helmer Dorothea , Rapp Bastian E. 
Published: April 2018

AbstractFused silica glass is one of the most important high‐performance materials for scientific research, industry, and society. However due to its high chemical and thermal resistance as well as high hardness, fused silica glass is notoriously difficult to structure. This work introduces Glassomer, a solid nanocomposite, which can be structured using polymer molding and subtractive technologies at submicrometer resolution. After polymer processing Glassomer is turned into optical grade fused silica glass during a final heat treatment. The resulting glass has the same optical transparency as commercial fused silica and a smooth surface with a roughness of a few nanometers. This work makes high‐performance fused silica glass components accessible to high‐throughput fabrication technologies and will enable numerous optical, photonic and medical applications in science and industry.
Oxidized Laser‐Induced Graphene for Efficient Oxygen Electrocatalysis
Authors: Zhang Jibo , Ren Muqing , Wang Luqing , Li Yilun , Yakobson Boris I. , Tour James M. 
Published: April 2018

AbstractAn efficient metal‐free catalyst is presented for oxygen evolution and reduction based on oxidized laser‐induced graphene (LIG‐O). The oxidation of LIG by O2 plasma to form LIG‐O boosts its performance in the oxygen evolution reaction (OER), exhibiting a low onset potential of 260 mV with a low Tafel slope of 49 mV dec−1, as well as an increased activity for the oxygen reduction reaction. Additionally, LIG‐O shows unexpectedly high activity in catalyzing Li2O2 decomposition in Li‐O2 batteries. The overpotential upon charging is decreased from 1.01 V in LIG to 0.63 V in LIG‐O. The oxygen‐containing groups make essential contributions, not only by providing the active sites, but also by facilitating the adsorption of OER intermediates and lowering the activation energy.
Self‐Assembled Semiconducting Polymer Nanoparticles for Ultrasensitive Near‐Infrared Afterglow Imaging of Metastatic Tumors
Authors: Xie Chen , Zhen Xu , Miao Qingqing , Lyu Yan , Pu Kanyi 
Published: April 2018

AbstractDetection of metastatic tumor tissues is crucial for cancer therapy; however, fluorescence agents that allow to do share the disadvantage of low signal‐to‐background ratio due to tissue autofluorescence. The development of amphiphilic poly(p‐phenylenevinylene) derivatives that can self‐assemble into the nanoagent (SPPVN) in biological solutions and emit near‐infrared afterglow luminescence after cessation of light irradiation for ultrasensitive imaging of metastatic tumors in living mice is herein reported. As compared with the counterpart nanoparticle (PPVP) prepared from the hydrophobic PPV derivate, SPPVN has smaller size, higher energy transfer efficiency, and brighter afterglow luminescence. Moreover, due to the higher PEG density of SPPVN relative to PPVP poly(ethylene glycol), SPPVN has a better accumulation in tumor. Such a high sensitivity and ideal biodistribution allow SPPVN to rapidly detect xenograft tumors with the size as small as 1 mm3 and tiny peritoneal metastatic tumors that are almost invisible to naked eye, which is not possible for PPVP. Moreover, the oxygen‐sensitive afterglow makes SPPVN potentially useful for in vivo imaging of oxygen levels. By virtue of enzymatic biodegradability and ideal in vivo clearance, these organic agents can serve as a platform for the construction of advanced afterglow imaging tools.
Adamantanes Enhance the Photovoltaic Performance and Operational Stability of Perovskite Solar Cells by Effective Mitigation of Interfacial Defect States
Authors: Tavakoli Mohammad Mahdi , Bi Dongqin , Pan Linfeng , Hagfeldt Anders , Zakeeruddin Shaik Mohammed , Grätzel Michael 
Published: April 2018

AbstractPassivation of electronic defects is an effective strategy to boost the performance and operational stability of perovskite solar cells (PSCs). Identifying molecular materials that achieve this purpose is a key target of current research efforts. Here, adamantane (AD) and 1‐adamantylamine (ADA) are introduced as molecular modulators to abate electronic defects present within the bulk and at the perovskite–hole conductor interface. To this effect, the modulator is added either into the antisolvent (AS) to precipitate it together with the perovskite (AS method) or they are spin coated (SC) onto its surface (SC method). Time‐resolved photoluminescence measurements show substantially longer lifetimes for perovskite films treated with AD and ADA compared to the reference sample. In line with this observation, it is found that the presence of AD and ADA molecules at the interface between the perovskite film and the hole conductor increases all photovoltaic metrics, in particular the open circuit photovoltage (V
oc) as well as the operational stability of the PSC.
Definitive Structural Identification toward Molecule‐Type Sites within 1D and 2D Carbon‐Based Catalysts
Authors: Jiang Hongliang , He Qun , Wang Changda , Liu Hengjie , Zhang Youkui , Lin Yunxiang , Zheng Xusheng , Chen Shuangming , Ajayan Pulickel M. , Song Li 
Published: April 2018

AbstractDeveloping facile preparation routes and atomic‐level characterization methods for single‐atom catalysts is highly desirable but still challenging. Herein, a general strategy is proposed to construct transition metal single atoms within 1D and 2D carbon supports. The carbon supports, typically graphene and carbon nanotubes, are coated with various transition metal‐containing bimetal hydroxides, followed by polydopamine coating and high‐temperature pyrolysis. X‐ray absorption fine structure spectroscopy measurements and simulations efficiently indicate that single atoms (Co, Fe, or Cu) are captured within the applied carbon supports, distinctively forming exclusive molecule‐type sites. As a proof‐of‐concept application, the obtained catalysts exhibit remarkable performance for electrochemical oxygen reduction reaction, even surpassing commercial Pt/C catalyst. The developed versatile route opens up new avenues for the design of carbon‐based catalysts with definite molecular active sites. The atomic‐level structural identifications provide significant guidance for mechanistic studies toward single‐atom catalysts.
Geometric Potential and Dirac Quantization
Authors: Lian Dingkun , Hu Liangdong , Liu Quanhui 
Published: April 2018

AbstractA fundamental problem regarding the Dirac quantization of a free particle on an () curved hypersurface embedded in N flat space is the impossibility to give the same form of the curvature‐induced quantum potential, the geometric potential as commonly called, as that given by the Schrödinger equation method where the particle moves in a region confined by a thin‐layer sandwiching the surface. This problem is resolved by means of a previously proposed scheme that hypothesizes a simultaneous quantization of positions, momenta, and Hamiltonian, among which the operator‐ordering‐free section is identified and is then found sufficient to lead to the expected form of geometric potential.
Linear‐Quadratic Optimal Control Problems for Mean‐Field Stochastic Differential Equations with Jumps
Authors: Tang Maoning , Meng Qingxin 
Published: April 2018

AbstractIn this paper, we study a linear‐quadratic optimal control problem for mean‐field stochastic differential equations driven by a Poisson random martingale measure and a one‐dimensional Brownian motion. Firstly, the existence and uniqueness of the optimal control is obtained by the classic convex variation principle. Secondly, by the duality method, the optimality system, also called the stochastic Hamilton system which turns out to be a linear fully coupled mean‐field forward‐backward stochastic differential equation with jumps, is derived to characterize the optimal control. Thirdly, applying a decoupling technique, we establish the connection between two Riccati equations and the stochastic Hamilton system and then prove the optimal control has a state feedback representation.
To share or not to share? Explaining willingness to share in the context of social distance
Authors: Schreiner Nadine , Pick Doreén , Kenning Peter 
Published: April 2018

AbstractSharing can help make goods available to many people who would otherwise have no access to them. In the effort of motivating more people to participate in the sharing economy, it is useful to know the variables that influence the willingness to share (WTS). Our study aims to identify these variables. Applying field theory, we conducted an experiment based on nonmonetary sharing situations. Complementing existing research directed towards users of goods, we focused on the providers of goods, thus broadening the understanding of sharing contexts. We demonstrate that WTS can be explained by several variables. In particular, a low social distance increases individuals' WTS their belongings with others. Product involvement is also a predictor of whether or not people are willing to share. In contrast, consumer characteristics such as materialism, altruism, and interpersonal trust have no impact on sharing intentions. Our findings provide significant implications for consumer research and for the marketing of sharing organizations.
Mechanistic Study of Suzuki–Miyaura Cross‐Coupling Reactions of Amides Mediated by [Pd(NHC)(allyl)Cl] Precatalysts
Authors: Li Guangchen , Lei Peng , Szostak Michal , Casals‐Cruañas Eric , Poater Albert , Cavallo Luigi , Nolan Steven P. 
Published: April 2018

AbstractWe report a combined experimental and computational investigation of the Suzuki–Miyaura cross‐coupling of amides enabled by [Pd(NHC)(allyl)Cl] precatalysts. Most crucially, mechanistic details pertaining to the Pd0/NHC catalytic cycle were elucidated by computational methods. Mechanistic insights shed light on the role of each ligand about the metal. Sterics play a key role in the initial activation of the catalyst. As a key insight, we have shown that water participates in the activation of the Pd‐NHC catalytic system. Easier activation has led to effect room temperature cross‐coupling of a broad range of amides through selective N−C bond scission under the mildest conditions reported to date. The use of sterically hindered [Pd(IPr*)(cin)Cl] reported herein for the first time in the amide cross‐coupling indicates that increasing flexible steric bulk of the isopropyl wingtip groups of the NHC ligand provides a modular scaffold for promoting amide cross‐coupling in high yields. The precatalytic pathway involving both NHC ligands as well as the catalytic cycle beginning from the Pd0 species are discussed. The mechanistic details provide insight into the amide bond twist (distortion) that leads to N−C cross‐coupling reactions and is required for the efficient N−C bond activation.
Kinetics Are Crucial When Targeting Copper Ions to Fight Alzheimer's Disease: An Illustration with Azamacrocyclic Ligands
Authors: Conte‐Daban Amandine , Beyler Maryline , Tripier Raphaël , Hureau Christelle 
Published: April 2018

AbstractTargeting copper ions to either remove or redistribute them is currently viewed as a possible therapeutic strategy in the context of Alzheimer's disease (AD). Thermodynamic parameters, as for instance the copper(II) affinity of the drug candidate or the copper(II) over zinc(II) selectivity, are considered in the design of the drug candidate. In contrast, kinetic factors have been overlooked despite their probable high importance. In the present article, we use a series of azamacrocyclic ligands to demonstrate that kinetic issues must be taken into account when designing copper‐targeting drug candidates in the context of AD.
Microstructure Characterization of an Aluminium Alloy Processed by Milling Followed by Spark Plasma Sintering
Authors: Charfeddine Saifeddine , Zehani Karim , Bessais Lotfi , Korchef Atef 
Published: April 2018

AbstractIn the present work, the microstructure and thermal stability of a commercial nanocrystalline aluminum alloy produced by combining equal channel angular pressing and ball milling followed by spark plasma sintering are characterized by X‐ray diffraction, optical microscopy, scanning electron microscopy and transmission electron microscopy. It is shown that the combination of different severe plastic deformation techniques, results to refining the grain size to a larger extent and improving the temperature range in which the grain size remains in the nanometer domain for temperatures as high as 400 °C. This broadens the scope of using the nanocrystalline aluminium alloy for high temperature industrial applications.
Different attention bias patterns in anorexia nervosa restricting and binge/purge types
Authors: Gilon Mann Tal , Hamdan Sami , Bar‐Haim Yair , Lazarov Amit , Enoch‐Levy Adi , Dubnov‐Raz Gal , Treasure Janet , Stein Daniel 
Published: April 2018

AbstractPatients with anorexia nervosa (AN) have been shown to display both elevated anxiety and attentional biases in threat processing. In this study, we compared threat‐related attention patterns of patients with AN restricting type (AN‐R; n = 32), AN binge/purge type (AN‐B/P; n = 23), and healthy controls (n = 19). A dot‐probe task with either eating disorder‐related or general and social anxiety‐related words was used to measure attention patterns. Severity of eating disorder symptoms, depression, anxiety, and stress were also assessed. Patients with AN‐R showed vigilance to both types of threat words, whereas patients with AN‐B/P showed avoidance of both threat types. Healthy control participants did not show any attention bias. Attention bias was not associated with any of the demographic, clinical, and psychometric parameters introduced. These findings suggest that there are differential patterns of attention allocation in patients with AN‐R and AN‐B/P. More research is needed to identify what causes/underlies these differential patterns.
Risk of small intestinal bacterial overgrowth in patients receiving proton pump inhibitors versus proton pump inhibitors plus prokinetics
Authors: Revaiah Pruthvi C , Kochhar Rakesh , Rana Surinder V , Berry Neha , Ashat Munish , Dhaka Narendra , Rami Reddy Y , Sinha Saroj K 
Published: April 2018

Background and AimIntestinal dysmotility is considered a risk factor for small intestinal bacterial overgrowth (SIBO). Prokinetics improve intestinal motility and are often prescribed with proton pump inhibitors (PPIs) in patients with gastroesophageal reflux disease (GERD) and/or functional dyspepsia. The present study aimed to evaluate the prevalence of SIBO and the orocecal transit time (OCTT) in patients taking PPI compared with those taking PPI plus prokinetics.MethodsThe study is a single‐center, cross‐sectional study. Enrolled patients (with age > 12 years) were divided into two groups: patients taking PPIs for more than 3 months (Group A) and those taking PPIs with prokinetics for more than 3 months (Group B) for various indications. Lactulose breath test (LBT) for OCTT and glucose breath test (GBT) for SIBO were conducted for all patients.ResultsOf the 147 enrolled patients, SIBO was documented in 13.2% patients in Group A versus 1.8% in Group B, P = 0.018. Median OCTT in Group A was 130 (105–160) min compared with 120 (92.5–147.5) min in Group B (P = 0.010). Median OCTT among SIBO‐positive patients was 160 (140–172.5) min compared with SIBO‐negative patients, where it was 120 (103.75–150) min (P = 0.002). The duration and type of PPI used were not associated with the occurrence of SIBO in our study.ConclusionThe use of prokinetics in patients on PPI may reduce the risk of SIBO by enhancing intestinal motility and may reduce SIBO risk associated with long‐term PPI use.
Highly sensitive VOC gas sensor employing deep cooling of SERS film
Authors: Oh Myoung‐Kyu , De Ranjit , Yim Sang‐Youp 
Published: April 2018

AbstractThe potential of surface‐enhanced Raman spectroscopy (SERS) as a highly sensitive and selective gas sensor was investigated experimentally. Especially, the relation between the temperature of a SERS film and gas adsorption or signal intensity was observed systemically and quantitatively, from which the enhancement of gas adsorption and signal intensity by up to 40 times was observed with the SERS film temperature of approx. −80 °C, which corresponds to theoretical anticipation and leads to detection sensitivity defined by limit of detection in 3σ ~1 ppb in case of benzene gas within 2‐min acquisition time. For SERS, Ag nanorod array films functionalized by propanethiol and a spectrometer with a fiber Raman probe and 785‐nm pump laser were employed. The target volatile organic compound gas was benzene. The detection sensitivity of the SERS sensor was ~1 ppm at room temperature within 2‐min acquisition time.