bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photocatalytically Powered Matchlike Nanomotor for Light‐Guided Active SERS Sensing
Authors: Wang Yong , Zhou Chao , Wang Wei , Xu Dandan , Zeng Fanyu , Zhan Chen , Gu Jiahui , Li Mingyu , Zhao Weiwei , Zhang Jiaheng , Guo Jinhong , Feng Huanhuan , Ma Xing 
Published: August 2018

AbstractSurface enhanced Raman spectroscopy (SERS) is a powerful optical sensing technique that can detect analytes of extremely low concentrations. However, the presence of enough SERS probes in the detection area and a close contact between analytes and SERS probes are critical for efficient acquisition of a SERS signal. Presented here is a light‐powered micro/nanomotor (MNM) that can serve as an active SERS probe. The matchlike AgNW@SiO2 core–shell structure of the nanomotors work as SERS probes based on the shell‐isolated enhanced Raman mechanism. The AgCl tail serves as photocatalytic nanoengine, providing a self‐propulsion force by light‐induced self‐diffusiophoresis. The phototactic behavior was utilized to achieve enrichment of the nanomotor‐based SERS probes for on‐demand biochemical sensing. The results demonstrate the possibility of using photocatalytic nanomotors as active SERS probes for remote, light‐controlled, and smart biochemical sensing on the micro/nanoscale.
Controllable Synthesis of Few‐Layer Bismuth Subcarbonate by Electrochemical Exfoliation for Enhanced CO2 Reduction Performance
Authors: Zhang Ying , Zhang Xiaolong , Ling Yunzhi , Li Fengwang , Bond Alan M. , Zhang Jie 
Published: August 2018

AbstractTwo‐dimensional (2D) engineering of materials has been recently explored to enhance the performance of electrocatalysts by reducing their dimensionality and introducing more catalytically active ones. In this work, controllable synthesis of few‐layer bismuth subcarbonate nanosheets has been achieved via an electrochemical exfoliation method. These nanosheets catalyse CO2 reduction to formate with high faradaic efficiency and high current density at a low overpotential owing to the 2D structure and co‐existence of bismuth subcarbonate and bismuth metal under catalytic turnover conditions. Two underlying fast electron transfer processes revealed by Fourier‐transformed alternating current voltammetry (FTacV) are attributed to CO2 reduction at bismuth subcarbonate and bismuth metal. FTacV results also suggest that protonation of CO2.− is the rate determining step for bismuth catalysed CO2 reduction.
A Topochemical Approach to Synthesize Layered Materials Based on the Redox Reactivity of Anionic Chalcogen Dimers
Authors: Sasaki Shunsuke , Driss Dalel , Grange Elodie , Mevellec Jean‐Yves , Caldes Maria Teresa , Guillot‐Deudon Catherine , Cadars Sylvian , Corraze Benoît , Janod Etienne , Jobic Stéphane , Cario Laurent 
Published: August 2018

AbstractLayered transition metal compounds represent a major playground to explore unconventional electric or magnetic properties. In that framework, topochemical approaches that mostly preserve the topology of layered reactants have been intensively investigated to tune properties and/or design new materials. Topochemical reactions often involve the insertion or deinsertion of a chemical element accompanied by a change of oxidation state of the cations only. Conversely, cases where anions play the role of redox centers are very scarce. Here we show that the insertion of copper into two dimensional precursors containing chalcogen dimers (Q2)2− (Q=S, Se) can produce layered materials with extended (CuQ) sheets. The reality of this topochemical reaction is demonstrated here for different pristine materials, namely La2O2S2, Ba2F2S2, and LaSe2. Therefore, this work opens up a new synthetic strategy to design layered transition metal compounds from precursors containing polyanionic redox centers.
An Ultrahigh Mobility in Isomorphic Fluorobenzo[c][1,2,5]thiadiazole‐Based Polymers
Authors: Lee Junghoon , Kang So‐Huei , Lee Sang Myeon , Lee Kyu Cheol , Yang Heesoo , Cho Yongjoon , Han Daehee , Li Yongfang , Lee Byoung Hoon , Yang Changduk 
Published: August 2018

AbstractTo understand the effects rendered on the relevant basic physical properties and device function by controlling the regiochemistry of the cyclopenta[1,2‐b:5,4‐b′]dithiophene‐fluorobenzo[c][1,2,5]thiadiazole polymer (hereafter referred to as the CDT‐FBT polymer), two polymers, the regiorandom polymer (RA) and regioregular version (RR), respectively, are synthesized and characterized. In addition, an efficient route for synthesizing a key monomer for RR using various synthesis scope and optimizing the reaction conditions is discussed. Although RA exhibits optical, electrochemical, and morphological properties similar to RR, it shows better field‐effect transistor (FET) performance. Surprisingly, by employing a capillarity‐mediated sandwich‐casting process on a nanogrooved substrate, an unprecedented mobility of 17.8 cm2 V−1 s−1 is obtained for RA‐based FETs; this mobility value is almost twofold greater than those of the corresponding RR‐based FETs. For the first time, this study challenges previously reported results in that high carrier mobility is related to the high degree of polymer order induced by the backbone regioregularity.
Synthesis, Structural Reassignment, and Antibacterial Evaluation of 2,18‐Seco‐Lankacidinol B
Authors: Yao Yanmin , Cai Lingchao , Seiple Ian B. 
Published: August 2018

AbstractLankacidins are a group of polyketide natural products with activity against several strains of Gram‐positive bacteria. We developed a route to stereochemically diverse variants of 2,18‐seco‐lankacidinol B and found that the stereochemical assignment at C4 requires revision. This has interesting implications for the biosynthesis of natural products of the lankacidin class, all of which possessed uniform stereochemistry prior to this finding. We have evaluated 2,18‐seco‐lankacidinol B and three stereochemical derivatives against a panel of pathogenic Gram‐positive and Gram‐negative bacteria.
PNA Hybrid Sequences as Recognition Units in SNARE‐Protein‐Mimicking Peptides
Authors: Hubrich Barbara E. , Kumar Pawan , Neitz Hermann , Grunwald Matthias , Grothe Tobias , Walla Peter Jomo , Jahn Reinhard , Diederichsen Ulf 
Published: August 2018

AbstractMembrane fusion is an essential process in nature and is often accomplished by the specific interaction of SNARE proteins. SNARE model systems, in which SNARE domains are replaced by small artificial units, represent valuable tools to study membrane fusion in vitro. The synthesis and analysis is presented of SNARE model peptides that exhibit a recognition motif composed of two different types of peptide nucleic acid (PNA) sequences. This novel recognition unit is designed to mimic the SNARE zippering mechanism that initiates SNARE‐mediated fusion. It contains N‐(2‐aminoethyl)glycine‐PNA (aeg‐PNA) and alanyl‐PNA, which both recognize the respective complementary strand but differ in duplex topology and duplex formation kinetics. The duplex formation of PNA hybrid oligomers as well as the fusogenicity of the model peptides in lipid‐mixing assays were characterized and the peptides were found to induce liposome fusion. As an unexpected discovery, peptides with a recognition unit containing only five aeg‐PNA nucleo amino acids were sufficient and most efficient to induce liposome fusion.
DNA‐Mediated Proximity‐Based Assembly Circuit for Actuation of Biochemical Reactions
Authors: Oh Sung Won , Pereira Adriana , Zhang Ting , Li Tianran , Lane Ariel , Fu Jinglin 
Published: August 2018

AbstractSmart nanodevices that integrate molecular recognition and signal production hold great promise for the point‐of‐care (POC) diagnostic applications. Herein, the development of a DNA‐mediated proximity assembly of biochemical reactions, which was capable of sensing various bio‐targets and reporting easy‐to‐read signals is reported. The circuit was composed of a DNA hairpin‐locked catalytic cofactor with inhibited activity. Specific molecular inputs can trigger a conformational switch of the DNA locks through the mechanisms of toehold displacement and aptamer switching, exposing an active cofactor. The subsequent assembly of an enzyme/cofactor pair actuated a reaction to produce colorimetric or fluorescence signals for detecting target molecules. The developed system could be potentially applied to smart biosensing in molecular diagnostics and POC tests.
Asymmetric Synthesis of Dihydropyranones via Gold(I)‐Catalyzed Intermolecular [4+2] Annulation of Propiolates and Alkenes
Authors: Kim Hanbyul , Choi Su Yeon , Shin Seunghoon 
Published: August 2018

AbstractIntermolecular asymmetric gold catalysis involving alkyne activation presents a significant challenge due to its distinct mechanistic mode from other metals. Herein, we report a highly enantioselective synthesis of α,β‐unsaturated δ‐lactones from [4+2] annulation of propiolates and alkenes in upto 95 % ee. Notably, for the desired chiral recognition, the choice of 1,1,2,2‐tetrachloroethane as solvent was found to be crucial. Furthermore, an anionic surfactant (sodium dodecyl sulfate) improved the product selectivity in the divergence of the cyclopropyl gold carbene intermediate.
Real‐Space Observation of Atomic Site‐Specific Electronic Properties of a Pt Nanoisland/Au(111) Bimetallic Surface by Tip‐Enhanced Raman Spectroscopy
Authors: Su Hai‐Sheng , Zhang Xia‐Guang , Sun Juan‐Juan , Jin Xi , Wu De‐Yin , Lian Xiao‐Bing , Zhong Jin‐Hui , Ren Bin 
Published: August 2018

AbstractResolving atomic site‐specific electronic properties and correlated substrate–molecule interactions is challenging in real space. Now, mapping of sub‐10 nm sized Pt nanoislands on a Au(111) surface was achieved by tip‐enhanced Raman spectroscopy, using the distinct Raman fingerprints of adsorbed 4‐chlorophenyl isocyanide molecules. A spatial resolution better than 2.5 nm allows the electronic properties of the terrace, step edge, kink, and corner sites with varying coordination environments to be resolved in real space in one Pt nanoisland. Calculations suggest that low‐coordinate atomic sites have a higher d‐band electronic profile and thus stronger metal–molecule interactions, leading to the observed blue‐shift of Raman frequency of the N≡C bond of adsorbed molecules. An experimental and theoretical study on Pt(111) and mono‐ and bi‐atomic layer Pt nanoislands on a Au(111) surface reveals the bimetallic effect that weakens with the increasing number of deposited Pt adlayer.
Discovery of Small Molecule Ligands for MALAT1 by Tuning an RNA‐Binding Scaffold
Authors: Donlic Anita , Morgan Brittany S. , Xu Jason L. , Liu Anqi , Roble Carlos , Hargrove Amanda E. 
Published: August 2018

AbstractStructural studies of the 3′‐end of the oncogenic long non‐coding RNA metastasis‐associated lung adenocarcinoma transcript 1 (MALAT1) confirmed a unique triple‐helix structure. This structure enables accumulation of the transcript, and high levels of MALAT1 are found in several cancers. Here, we synthesize a small molecule library based on an RNA‐binding scaffold, diphenylfuran (DPF), screen it against a variety of nucleic acid constructs, and demonstrate for the first time that the MALAT1 triple helix can be selectively targeted with small molecules. Computational analysis revealed a trend between subunit positioning and composition on DPF shape and intramolecular interactions, which in turn generally correlated with selectivity and binding strengths. This work thus provides design strategies toward chemical probe development for the MALAT1 triple helix and suggests that comprehensive analyses of RNA‐focused libraries can generate insights into selective RNA recognition.
Effect of Solvent, Preheating Temperature, and Time on the Ultrasonic Extraction of Phenolic Compounds from Cold‐Pressed Hempseed Cake
Authors: Liang Jingbang , Zago Erika , Nandasiri Ruchira , Khattab Rabie , Eskin N. A. Michael , Eck Peter , Thiyam‐Holländer Usha 
Published: August 2018

AbstractThe effect of different solvents (aqueous methanol [70%, v/v], aqueous acetone [80%, v/v], and a solvent mixture [MA] of aqueous methanol [70%, v/v] and aqueous acetone [70%, v/v] in a ratio of 1:1 [v/v]), preheating temperatures (140, 160, and 180°C), and times of exposure (5, 15, and 30 min) on the ultrasonic extraction of the main phenolic compounds from hempseed cake (Cannabis sativa) was investigated. A simplified new high‐performance liquid chromatography (HPLC) method was developed to identify and quantify the main phenolics (namely, N‐trans‐caffeoyltyramine and cannabisin B) in the extracts. Two other main compounds, numbered 3 and 4, were also detected. The results showed that the nature of the extracting solvent had a significant (P < 0.05) impact on the ultrasonic extraction of phenolic compounds. The acetone extracts exhibited the highest total phenolic content (TPC), followed by MA and methanol. The preheating temperature and time of exposure enhanced the TPC for all solvents examined. The main phenolics, N‐trans‐caffeoyltyramine, cannabisin B, and compound 3, were positively affected by the temperature and time of exposure, irrespective of the solvents used. In sharp contrast, compound 4 appeared to be thermally sensitive: increasing preheating time and temperature decreased the yields of this compound. This study demonstrated that acetone was the most effective extracting solvent and that preheating enhanced the yield of the main phenolics.
Evaluating co‐substrates to supplement biogas production from tannery solid waste treatment – cattle hair, microalgae biomass, and silicone
Authors: Agustini Caroline B. , da Fontoura Juliana T. , Mella Bianca , Gutterres Mariliz 
Published: August 2018

AbstractThe sustainability of bioenergy production depends largely on the biomass resource and technology used. Several types of organic wastes can be converted into biogas via anaerobic digestion. The purpose of this research was to evaluate the influence of the addition of cattle hair waste, microalgae biomass, or commercial silicone as a third co‐substrate in the co‐digestion of the two solid wastes of major concern to the leather industry: leather shavings and sludge from tannery wastewater treatment plants. The addition of cattle hair did not influence the total cumulative biogas production of 19.4 mL g−1 of volatile suspended solid added, adsorbed practically all the chromium present, and increased by 16% the organic load of the medium, due to the hydrolysis of the hair damaging the treatment of the residues. The addition of microalgae doubled the cumulative biogas production, tripled the maximum daily biogas production, and adsorbed three times more chromium, showing its beneficial effect on the treatment of tannery solid waste for biogas production. The addition of commercial silicone did not influence the total cumulative biogas production but led to a high adsorption capacity for both chromium and organic matter. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd
Development and validation of an LC–MS/MS method for the determination of DPHB in rat plasma and its application in pharmacokinetic studies
Authors: Wen Qi , Li Hai‐Long , Chen Feng , Gong Jing‐Wen , Guan Wei‐Wei , Fu Nai‐Guang , Tan Yin‐Feng 
Published: August 2018

AbstractThe aim of the present study was to develop a rapid, specific and sensitive LC–MS/MS method for the determination of DPHB [7‐(4″‐hydroxy‐3″‐methoxyphenyl)‐1‐phenyl‐4‐hepten‐3‐one] in rat plasma using yakuchinone A as an internal standard (IS). n‐Hexane was used for the extraction of DPHB from rat plasma. Chromatographic separation of DPHB was achieved using a Kinetex XB‐C18 column (2.10 × 50 mm, 2.6 μm) at 40°C. The mobile phase consisted of water (containing 0.1‰ formic acid, A) and acetonitrile (containing 0.1‰ formic acid, B) under a gradient elution at a flow rate of 0.3 mL min−1. Positive electrospray ionization and multiple reaction monitoring mode were used for detection. The selected precursor ion to product ion pairs, m/z 311.3 → 137.0 for DPHB and m/z 313.1 → 137.0 for yakuchinone A, were monitored. Good linearity was observed over the concentration range from 2 to 2000 ng mL−1 (r = 0.9969). The recovery efficiency of DPHB from rat plasma was 54.8–69.7%, while the matrix effect ranged from 99.7 to 113%. Intra‐ and inter‐day precision and accuracy values were within ±15% at three different quality control concentration levels. This validated method was successfully applied to pharmacokinetic studies in rats after a single p.o. or i.v. dose of DPHB solution. The route of administration significantly influenced systemic exposure to DPHB, and low bioavailability of DPHB was observed. The method developed here will be further improved and used in future pharmacokinetic studies.
Transcellular Spreading of Tau in Tauopathies
Authors: Demaegd Koen , Schymkowitz Joost , Rousseau Frederic 
Published: August 2018

AbstractTau, a microtubule‐associated protein playing a key role in a group of neurodegenerative diseases such as Alzheimer's disease, spreads throughout the brain, inducing pathology. A model akin to the spreading of prions has been raised owing to similar characteristics of inducing an abnormal protein conformation as a method of self‐amplification, spreading protein aggregates over anatomically linked pathways. The search to identify the “seeds” that induce conformational change has received much attention; however, less is known about the mechanisms by which tau is transmitted from cell to cell, so‐called “transcellular spreading”. In this review, we gather evidence regarding the spreading of tau throughout the brain and provide an overview of methods by which tau can be released from neurons as well as taken up. Furthermore, we bring together mechanisms of neurotoxicity behind tau spreading. Advancing our understanding about the spreading of tau can guide the search for therapeutic options for multiple neurodegenerative diseases aggregating tau.
Synthetic Receptors for the Recognition and Discrimination of Post‐Translationally Methylated Lysines
Authors: Gruber Tobias 
Published: August 2018

AbstractPost‐translational modifications (PTMs) describe the chemical alteration of proteins after their biosynthesis in ribosomes. PTMs play important roles in cell biology, including the regulation of gene expression, cell–cell interactions and the development of different diseases. A prominent class of PTMs is the side‐chain methylation of lysine. For the analysis and discrimination of differently methylated lysines, antibodies are widely used, although methylated peptide and protein targets are known to be particularly difficult to differentiate by antibody‐based affinity reagents; an additional challenge can be batch‐to‐batch reproducibility. The application of mass spectrometry techniques for methyllysine discrimination requires a complex sample preparation procedure and is not suited for working in cells. The desire to overcome the above‐mentioned challenges has promoted the development of synthetic receptor molecules that recognise and bind methyllysines. Such “artificial antibodies” are of interest for a number of applications, for example, as reagents in biochemical assays, for the isolation and purification of post‐translationally methylated proteins and for the tracking of signalling pathways. Moreover, they offer new approaches in diagnostics and therapy. This review delivers an overview of the broad field of methyllysine binding and covers a wide range of synthetic receptors used for the recognition of methylated lysines, including calixarenes, resorcinarenes, pillararenes, disulfide cyclophanes, cucurbiturils and acyclic receptors.
Photoactivatable Myristic Acid Probes for UNC119‐Cargo Interactions
Authors: Kaiser Nadine , Mejuch Tom , Fedoryshchak Roman , Janning Petra , Tate Edward W. , Waldmann Herbert 
Published: August 2018

AbstractProtein myristoylation plays key roles in biological processes, for instance, in membrane attachment and activation of proteins and in mediating protein–protein and protein–lipid interactions. Furthermore, myristoylated proteins are involved in disorders, including cancer and viral infections. Therefore, new tools to study protein myristoylation are in high demand. Herein, we report the development of photoactivatable probes, based on a diazirine‐substituted analogue of myristic acid. The probes bind to and, upon irradiation, covalently label the lipid‐binding chaperone protein uncoordinated 119 (UNC119). UNC119 increases overall solubility and regulates specifically the transport of myristoylated proteins between intercellular membranes. The binding mode of the probes is similar to that of the myristate moiety, and the residues inside the hydrophobic pocket of UNC119 proteins that are critical for covalent binding have been identified. The interaction with UNC119 was also demonstrated in cell lysate by means of affinity enrichment. Moreover, it is shown that the myristate analogue can be incorporated into peptide substrates by N‐myristoyl transferases of Leishmania and Trypanosoma protozoan parasites.
Synthesis of 3,6‐Dihydro‐2H‐[1, 2]‐Oxazines from Nitroarenes and Conjugated Dienes, Catalyzed by Palladium/Phenanthroline Complexes and Employing Phenyl Formate as a CO Surrogate
Authors: EL‐Atawy Mohamed A. , Formenti Dario , Ferretti Francesco , Ragaini Fabio 
Published: August 2018

AbstractPalladium/phenanthroline catalyzed reduction of nitroarenes by in situ‐generated carbon monoxide, from the decomposition of phenyl formate, affords the corresponding nitrosoarenes. The latter are trapped by conjugated dienes to give the corresponding 3,6‐dihydro‐2H‐[1, 2]‐oxazines (hetero Diels‐Alder adducts). Many functional groups are well tolerated. Yields are higher than those obtainable by any previously reported method, including the direct reaction of the diene with the pure nitrosoarene. The reaction can be performed in a single standard glass pressure tube, without the need for autoclaves or high‐pressure CO lines.
Templated Chromophore Assembly on Peptide Scaffolds: A Structural Evolution
Authors: Rocard Lou , Wragg Darren , Jobbins Samuel Alexander , Luciani Lorenzo , Wouters Johan , Leoni Stefano , Bonifazi Davide 
Published: August 2018

AbstractThe use of a template that bears pre‐programmed receptor sites for selectively accommodating chromophores at given positions is an attractive approach for engineering artificial‐light‐harvesting systems. Indulging this line of thought, this work tackles the creation of tailored antenna architectures with yellow, red and blue chromophores, exploiting three dynamic covalent reactions simultaneously, namely disulfide exchange, acyl hydrazone, and boronic ester formations. The effect of various structural modifications, such as the chromophores as well as their spatial organization (distance, orientation, order) on the energy transfer within the antennas was studied by means of steady‐state UV/Vis absorption and fluorescence spectroscopies. This systematic study allowed for a significant improvement of the energy‐transfer efficiencies to a noticeable 22 and 15 % for the yellow and red donors, respectively, across the chromophores to the blue acceptor. Metadynamics simulations suggested that the conformational properties of the antennas are driven by intramolecular chromophoric stacking interactions that, upon forcing the α‐helix to fold on itself, annul any effects deriving from the programming of the spatial arrangement of the receptor sides in the peptide backbone.