bluuebunny/crossref_metadata_2025_split huggingface dataset:
3D‐Printed Electrodes with Improved Mass Transport Properties
Authors: Lölsberg Jonas , Starck Ottokar , Stiefel Serafin , Hereijgers Jonas , Breugelmans Tom , Wessling Matthias 
Published: September 2017

AbstractToday's electrochemical reactor design is a less developed discipline as compared to electrocatalytic synthesis. Although catalysts show increasing conversion rates, they are often operated without measures for the reduction of concentration polarization effects. As a result, a stagnant boundary layer forms at the electrode‐electrolyte interface. This stagnant boundary layer presents an additional voltage drop and reduces the energy efficiency. It is generally accepted that this phenomenon is caused by a combination of fast electrode reactions and slow diffusion of the reacting species. Our earlier work demonstrated the potential of non‐conducting static mixers to reduce concentration polarization effects. However, there are few studies on conductive static mixers applied as electrodes. In this study, we present a new concept of additive manufactured flow through electrode mixers. Our electrode geometry combines a high surface area with mixing properties, diminishing concentration polarization effects of transport‐limited reactions. Mass transport properties of these conductive static mixers are evaluated in an additive manufactured electrochemical reactor under controlled conditions by applying the limiting‐current method.
High‐Stability Electrodes for High‐Temperature Proton Exchange Membrane Fuel Cells by Using Advanced Nanocarbonaceous Materials
Authors: Zamora Héctor , Plaza Jorge , Cañizares Pablo , Rodrigo Manuel A. , Lobato Justo 
Published: September 2017

AbstractThis work studies the stability and performance of a cathodic electrode for high‐temperature proton exchange membrane (HT‐PEMFC) systems prepared with a carbon nanosphere (CNS) based microporous layer and carbon nanofibers (CNFp) used as a catalyst support. The obtained results are compared with a standard Vulcan carbon XC72 based electrode. With this purpose, two membrane−electrode assemblies (MEAs) were prepared using the cathodic electrodes and tested in a 25 cm2 HT‐PEMFC system. Preliminary short‐life tests around 330 h were carried out with both MEAs. During the tests, different characterization procedures, consisting of polarization curves, spectroscopy impedance analysis, cyclic voltammetry and linear sweep voltammetry were performed in order to evaluate the evolution of the main stability and performance parameters of the MEAs. Results showed that the application of these new materials increases positively the stability of the MEA in comparison with the standard Vulcan carbon XC72 material, with a negligible decrease in the performance of the advanced MEA during all tests, making these results very promising to overcome the service lifetime limitations of these systems.
Intramolecular SEAr Reactions of Phosphorus Compounds: Computational Approach to the Synthesis of π‐Extended Heterocycles
Authors: Larrañaga Olatz , Romero‐Nieto Carlos , de Cózar Abel 
Published: September 2017

AbstractThe reaction mechanism associated with the synthesis of phosphorus‐based heteropolyaromatic architectures was investigated by DFT calculations at the B3LYP‐D3/6‐311+G(D) level of theory. The aim of this study is to provide essential information for the future development of improved polycyclic organophosphorus materials. To that end, the impact of the structure of the initial reactant and/or the intermediates structure on the mechanistic features and energetic profiles of the phosphorus cyclization process was studied. Moreover, the reactivity parameters were analyzed in detail in a conceptual DFT framework and the underlying reactivity trends were extracted. Thus, these findings provide important insights for a rational design of polycyclic phosphorus compounds.
Enhancing the Antimicrobial Activity of Alamethicin F50/5 by Incorporating N‐terminal Hydrophobic Triazole Substituents.
Authors: Das Sanjit , Ben Haj Salah Khoubaib , Wenger Emmanuel , Martinez Jean , Kotarba Jules , Andreu Vanessa , Ruiz Nicolas , Savini Filippo , Stella Lorenzo , Didierjean Claude , Legrand Baptiste , Inguimbert Nicolas 
Published: September 2017

AbstractA simple and efficient strategy is proposed to significantly improve the antibacterial activity of peptaibols and other antimicrobial peptides by N‐terminal capping with 1,2,3‐triazole bearing various hydrophobic substituents on C‐4. Such N‐terminal insertions on alamethicin F50/5 could enhance its antimicrobial activity on Gram‐positive bacteria without modification of its overall three‐dimensional structure. Although the native peptide and its analogues shared comparable helical contents, the crystal structure of one of the most active derivative showed a local slight distortion of the N‐terminal extremity, which was also observed in solution using NMR spectroscopy. Importantly, fluorescence studies showed that the N‐capped derivatives had increased affinity for liposomes, which may indicate they interacted more strongly with the bacterial membrane than alamethicin F50/5.
Formation and Structural Diversity of Organo‐Functionalized Tin–Silver Selenide Clusters
Authors: Rinn Niklas , Guggolz Lukas , Gries Katharina , Volz Kerstin , Senker Jürgen , Dehnen Stefanie 
Published: September 2017

AbstractWhen reacting the organic functionalized tin selenide clusters [(SnR1)3Se4Cl] (A, R1=CMe2CH2C(O)Me) or [(SnR1)4Se6] (B) with (SiMe3)2Se and [Ag(PPh3)3Cl] at −78 °C in CH2Cl2, a microcrystalline intermediate (compound 1) precipitates, which was investigated by magic angle spinning (MAS) NMR spectroscopy, powder X‐ray diffraction (PXRD), energy dispersive X‐ray (EDX) spectroscopy, and quantum chemistry calculations, to derive information about its composition and structure. Compound 1 re‐dissolves under reorganization into the organo‐functionalized Ag/Sn/Se cluster compound [Ag6(μ6‐Se)(Ag8Se12){(R1Sn)2Se2}6] (2), or the mixed‐valence cluster [(AgPPh3)2(SnIICl)2Se2{(R1SnIV)2Se2}2] (3), depending on the presence or the exclusion of daylight, respectively. The addition of N2H4⋅H2O to a solution of 1 yields selectively [Ag7(μ7‐Se)(Ag7Se12){(R2Sn)2Se2}6] (4, R2=CMe2CH2C(N2H2)Me), the Ag/Sn/Se core of which is isomeric to that of 2. 2–4 were characterized by X‐ray diffraction. NMR spectroscopic studies on solutions of 1 indicate the co‐existence of different species.
Magnetic Nanotransducers in Biomedicine
Authors: Grillone Agostina , Ciofani Gianni 
Published: September 2017

AbstractOwing to their abilities to identify diseased conditions, to modulate biological processes, and to control cellular activities, magnetic nanoparticles have become one of the most popular nanomaterials in the biomedical field. Targeted drug delivery, controlled drug release, hyperthermia treatment, imaging, and stimulation of several biological entities are just some of the several tasks that can be accomplished by taking advantage of magnetic nanoparticles in tandem with magnetic fields. The huge interest towards this class of nanomaterials arises from the possibility to physically drive their spatiotemporal localization inside the body, and to deliver an externally applied stimulation at a target site. They in fact behave as actual nanotransducers, converting energy stemming from the external magnetic field into heat and mechanical forces, which act as signals for therapeutic processes such as hyperthermia and controlled drug release. Magnetic nanoparticles are a noninvasive tool that enables the remote activation of biological processes, besides behaving as formidable tracers for different imaging modalities, thus allowing to simultaneously carry out diagnosis and therapy. In view of all this, owing to their multifunctional and multitasking nature, magnetic nanoparticles are already one of the most important nanotechnological protagonists in medicine and biology, enabling an actual theranostic approach in many pathological conditions. In this Concept, we first provide a brief introduction on some physical properties of magnetic materials and on important features that determine the physical properties of magnetic nanoparticles. Thereafter, we will consider some major biomedical applications: hyperthermia, drug delivery/release, and nanoparticle‐mediated control of biological processes, even at subcellular level.
Mechanistic Studies on the Role of [CuII(CO3)n]2−2n as a Water Oxidation Catalyst: Carbonate as a Non‐Innocent Ligand
Authors: Mizrahi Amir , Maimon Eric , Cohen Haim , Kornweitz Haya , Zilbermann Israel , Meyerstein Dan 
Published: September 2017

AbstractRecently it was reported that copper bicarbonate/carbonate complexes are good electro‐catalysts for water oxidation. However, the results did not enable a decision whether the active oxidant is a CuIII or a CuIV complex. Kinetic analysis of pulse radiolysis measurements coupled with DFT calculations point out that CuIII(CO3)n3−2n complexes are the active intermediates in the electrolysis of CuII(CO3)n2−2n solution. The results enable the evaluation of E°[(CuIII/II(CO3)n)aq]≈1.42 V versus NHE at pH 8.4. This redox potential is in accord with the electrochemical report. As opposed to literature suggestions for water oxidation, the present results rule out single‐electron transfer from CuIII(CO3)n3−2n to yield hydroxyl radicals. Significant charge transfer from the coordinated carbonate to CuIII results in the formation of C2O62− by means of a second‐order reaction of CuIII(CO3)n3−2n. The results point out that carbonate stabilizes transition‐metal cations at high oxidation states, not only as a good sigma donor, but also as a non‐innocent ligand.
C(sp3)−H Bond Activation by Vinylidene Gold(I) Complexes: A Concerted Asynchronous or Stepwise Process?
Authors: Klein Johannes E. M. N. , Knizia Gerald , Nunes dos Santos Comprido Laura , Kästner Johannes , Hashmi A. Stephen K. 
Published: September 2017

AbstractA detailed analysis of the C(sp3)−H activation process by vinylidene AuI complexes is described based on an intrinsic bond orbital analysis. Based on our analysis this event can be divided into three phases: (i) hydride transfer, (ii) C−C bond formation, and (iii) σ to π rearrangement of the lone pair coordinated to Au. Small perturbations of the system lead to either a concerted asynchronous reaction, or a stepwise reaction featuring an intermediate with a C‐H‐C three‐centre two‐electron (3c–2e) bond. The role of π‐donating substituents is highlighted and provides a way of controlling reactions of this type in future experimental studies.
Construction of Condensed Polycyclic Aromatic Frameworks through Intramolecular Cycloaddition Reactions Involving Arynes Bearing an Internal Alkyne Moiety
Authors: Yoshida Suguru , Shimizu Keita , Uchida Keisuke , Hazama Yuki , Igawa Kazunobu , Tomooka Katsuhiko , Hosoya Takamitsu 
Published: September 2017

AbstractFacile synthetic methods for condensed polycyclic aromatic compounds via aryne intermediates are reported. The generation of arynes bearing a (3‐arylpropargyl)oxy group from the corresponding o‐iodoaryl triflate‐type precursors efficiently afforded arene‐fused oxaacenaphthene derivatives, which were formed through intramolecular [2+4] cycloaddition. Extending the method to the generation of arynes bearing a 1,3‐diyne moiety led to a continuous generation of naphthalyne intermediate through the hexadehydro Diels–Alder reaction involving the aryne triple bond. This novel type of aryne‐relay chemistry enabled the synthesis of a unique aminoarylated oxaacenaphthene derivative and highly ring‐fused anthracene derivatives.
Total Synthesis of the Diglycosidic Tetramic Acid Ancorinoside A
Authors: Petermichl Markus , Schobert Rainer 
Published: September 2017

AbstractAncorinoside A, a metabolite of a sponge Ancorina sp., was prepared in 18 steps as the first derivative of this class of glycosylated 3‐acyltetramic acids. It features a β‐d‐glucopyranosyl‐(1→4)‐β‐d‐galacturonic acid linked to a d‐aspartic acid derived tetramic acid via a 3‐docosanoyl spacer. The diglycoside was built up by connecting the protected monosaccharides d‐galactose and d‐glucose via a thioglycoside glycosylation. Attachment of the spacer by a subsequent Schmidt glycosylation of this diglycoside, TEMPO oxidation to the uronic acid, functionalisation of the spacer terminus with an N‐(β‐ketoacyl)aspartate, and a final Dieckmann cyclisation were the key steps leading to ancorinoside A. This approach should also allow access to ancorinoside D.
High‐resolution imaging of muscle attachment structures in Caenorhabditis elegans
Authors: Qadota Hiroshi , Matsunaga Yohei , Nguyen Ken C.Q. , Mattheyses Alexa , Hall David H. , Benian Guy M. 
Published: September 2017

AbstractWe used structured illumination microscopy (SIM) to obtain super‐resolution images of muscle attachment structures in Caenorhabditis elegans striated muscle. SIM imaging of M‐line components revealed two patterns: PAT‐3 (β‐integrin) and proteins that interact in a complex with the cytoplasmic tail of β‐integrin and localize to the basal muscle cell membrane [UNC‐112 (kindlin), PAT‐4 (ILK), UNC‐97 (PINCH), PAT‐6 (α‐parvin), and UNC‐95], are found in discrete, angled segments with gaps. In contrast, proteins localized throughout the depth of the M‐line (UNC‐89 (obscurin) and UNC‐98) are imaged as continuous lines. Systematic immunostaining of muscle cell boundaries revealed that dense body components close to the basal muscle cell membrane also localize at cell boundaries. SIM imaging of muscle cell boundaries reveal “zipper‐like” structures. Electron micrographs reveal electron dense material similar in appearance to dense bodies located adjacent to the basolateral cell membranes of adjacent muscle cells separated by ECM. Moreover, by EM, there are a variety of features of the muscle cell boundaries that help explain the zipper‐like pattern of muscle protein localization observed by SIM. Short dense bodies in atn‐1 mutants that are null for α‐actinin and lack the deeper extensions of dense bodies, showed “zipper‐like” structures by SIM similar to cell boundary structures, further indicating that the surface‐proximal components of dense bodies form the “zipper‐like” structures at cell boundaries. Moreover, mutants in thin and thick filament components do not have “dot‐like” dense bodies, suggesting that myofilament tension is required for assembly or maintenance of proper dense body shape.
Functional N‐Formyl Peptide Receptor 2 (FPR2) Antagonists Based on the Ureidopropanamide Scaffold Have Potential To Protect Against Inflammation‐Associated Oxidative Stress
Authors: Stama Madia L. , Lacivita Enza , Kirpotina Liliya N. , Niso Mauro , Perrone Roberto , Schepetkin Igor A. , Quinn Mark T. , Leopoldo Marcello 
Published: September 2017

AbstractFormyl peptide receptor 2 (FPR2) is a G protein coupled receptor belonging to the N‐formyl peptide receptor (FPR) family that plays critical roles in peripheral and brain inflammatory responses. FPR2 has been proposed as a target for the development of drugs that could facilitate the resolution of chronic inflammatory reactions by enhancing endogenous anti‐inflammation systems. Starting from lead compounds previously identified in our laboratories, we designed a new series of ureidopropanamide derivatives with the goal of converting functional activity from agonism into antagonism and to develop new FPR2 antagonists. Although none of the compounds behaved as antagonists, some of the compounds were able to induce receptor desensitization and, thus, functionally behaved as antagonists. Evaluation of these compounds in an in vitro model of neuroinflammation showed that they decreased the production of reactive oxygen species in mouse microglial N9 cells after stimulation with lipopolysaccharide. These FPR2 ligands may protect cells from damage due to inflammation‐associated oxidative stress.
Tangential migration of corridor guidepost neurons contributes to anxiety circuits
Authors: Tinterri Andrea , Deck Marie , Keita Maryama , Mailhes Caroline , Rubin Anna Noren , Kessaris Nicoletta , Lokmane Ludmilla , Bielle Franck , Garel Sonia 
Published: September 2017

AbstractIn mammals, thalamic axons are guided internally toward their neocortical target by corridor (Co) neurons that act as axonal guideposts. The existence of Co‐like neurons in non‐mammalian species, in which thalamic axons do not grow internally, raised the possibility that Co cells might have an ancestral role. Here, we investigated the contribution of corridor (Co) cells to mature brain circuits using a combination of genetic fate‐mapping and assays in mice. We unexpectedly found that Co neurons contribute to striatal‐like projection neurons in the central extended amygdala. In particular, Co‐like neurons participate in specific nuclei of the bed nucleus of the stria terminalis, which plays essential roles in anxiety circuits. Our study shows that Co neurons possess an evolutionary conserved role in anxiety circuits independently from an acquired guidepost function. It furthermore highlights that neurons can have multiple sequential functions during brain wiring and supports a general role of tangential migration in the building of subpallial circuits.
Interconversion Rates between Conformational States as Rationale for the Membrane Permeability of Cyclosporines
Authors: Witek Jagna , Mühlbauer Max , Keller Bettina G. , Blatter Markus , Meissner Axel , Wagner Trixie , Riniker Sereina 
Published: September 2017

AbstractCyclic peptides have regained interest as potential inhibitors of challenging targets but have often a low bioavailability. The natural product cyclosporine A (CsA) is the textbook exception. Despite its size and polar backbone, it is able to passively cross membranes. This ability is hypothesized to be due to a conformational change from the low‐energy conformation in water to a “congruent” conformation that is populated both in water and inside the membrane. Here, we use a combination of NMR measurements and kinetic models based on molecular dynamics simulations to rationalize the difference in the membrane permeability of cyclosporine E (CsE) and CsA. The structure of CsE differs only in a backbone methylation, but its membrane permeability is one order of magnitude lower. The most striking difference is found in the interconversion rates between the conformational states favored in water and in chloroform, which are up to one order of magnitude slower for CsE compared to CsA.
Probing RNA Folding Pathways by RNA Fingerprinting
Authors: Woodson Sarah A. 
Published: September 2017

AbstractThis unit provides protocols for using native polyacrylamide gel electrophoresis to distinguish folding and unfolding conformers of RNA. It is useful for studying conformers that can exchange in a period of minutes or seconds, and that are thus difficult to study by solution‐based methods. Conformers that have been separated and immobilized in the gel matrix can be used to study catalytic activity with or without being eluted from the gel. The method can be applied to a wide variety of catalytic RNAs and RNA‐protein complexes. © 2017 by John Wiley & Sons, Inc.
Natural and Artificial Mn4Ca Cluster for the Water Splitting Reaction
Authors: Chen Changhui , Li Yanxi , Zhao Guoqing , Yao Ruoqing , Zhang Chunxi 
Published: September 2017

AbstractThe oxygen‐evolving center (OEC) in photosystem II (PSII) is a unique biological catalyst that splits water into electrons, protons, and O2 by using solar energy. Recent crystallographic studies have revealed that the structure of the OEC is an asymmetric Mn4Ca cluster, which provides a blueprint to develop man‐made water‐splitting catalysts for artificial photosynthesis. Although it is a great challenge to mimic the whole structure and function of the OEC in the laboratory, significant advances have recently been achieved. In this Minireview, recent progress on mimicking the natural OEC is discussed. New strategies are suggested to construct more stable and efficient new generation of catalytic materials for the water splitting reaction based on the artificial Mn4Ca cluster in the future.
Strongly Coupled Molybdenum Carbide on Carbon Sheets as a Bifunctional Electrocatalyst for Overall Water Splitting
Authors: Wang Hao , Cao Yingjie , Sun Cheng , Zou Guifu , Huang Jianwen , Kuai Xiaoxiao , Zhao Jianqing , Gao Lijun 
Published: September 2017

AbstractInvited for this month′s cover is the group of Prof. Lijun Gao in the Soochow Institute for Energy and Materials InnovationS (SIEMIS) at Soochow University. The image shows the overall water splitting catalyzed by a Mo2C‐based bifunctional electrocatalyst. The Full Paper itself is available at 10.1002/cssc.201701276.
Coenzyme Q10 Prevents the Interleukin‐1 Beta Induced Inflammatory Response via Inhibition of MAPK Signaling Pathways in Rat Articular Chondrocytes
Authors: Li Xing , Guo Yuanqing , Huang Shuai , He Minhui , Liu Qiaoli , Chen Weizhi , Liu Minghao , Xu Dongliang , He Peiheng 
Published: September 2017

ABSTRACT

Preclinical Research

Osteoarthritis (OA) is a widely prevalent degenerative joint disease that severely impairs the health of the elderly population resulting in a heavy economic burden worldwide. Coenzyme Q10 (CoQ10) has shown anti‐inflammatory effects in some diseases. The present study aimed to investigate if CoQ10 would suppress catabolic responses of interleukin (IL)‐1β‐induced chondrocytes. Rat chondrocytes were cultured and pretreated with CoQ10, and then stimulated with or without IL‐1β (10 ng/ml). The expression and production of matrix metalloproteinase (MMP)‐3, MMP‐9, and MMP13 were determined using real‐time PCR and Western blotting. CoQ10 suppressed MMP‐3, MMP‐9, and MMP13 production induced by IL‐1β, and markedly inhibited IL‐1β‐induced MAPK pathways in rat chondrocytes. The present study provides insight into potential mechanisms by which CoQ10 protects against degeneration of cartilage in patients with OA, which may lead to new approaches for the treatment of OA.Drug Dev Res 78 : 403‐410, 2017. © 2017 Wiley Periodicals, Inc.
[HDL‐C/apoA‐I]: A multivessel cardiometabolic risk marker in women with T2DM
Authors: Hermans Michel P. , Valensi Paul , Ahn Sylvie A. , Rousseau Michel F. 
Published: September 2017

AbstractAimsAlthough women have higher high‐density lipoprotein cholesterol (HDL‐C) than have men, their HDL particles are also prone to become small, dense, and dysfunctional in case of type 2 diabetes mellitus (T2DM). To assess the vascular risk related to HDLs of different sizes/densities without direct measurement, we adjusted HDL‐C to its main apolipoprotein (apoA‐I) as [HDL‐C/apoA‐I]. This ratio estimates HDL sizes and provides indices as to their number, cholesterol load, and density.MethodsWe stratified 280 Caucasian T2DM women according to [HDL‐C/apoA‐I] quartiles (Q) to determine how they are segregated according to cardiometabolic risk, β‐cell function, glycaemic control, and vascular complications. Five parameters were derived from combined determination of HDL‐C and apoA‐I: HDL size, HDL number, cholesterol load per particle (pP), apoA‐I pP, and HDL density.ResultsAn adverse cardiometabolic profile characterized QI and QII patients whose HDLs were denser and depleted in apoA‐I, whereas QIII patients had HDLs with characteristics closer to those of controls. QIV patients had HDLs of supernormal size/composition and a more favourable phenotype in terms of fat distribution; insulin sensitivity (64% vs 41%), metabolic syndrome, and β‐cell function (32% vs 23%); exogenous insulin (44 vs 89 U·d−1); and glycaemic control (glycated haemoglobin, 56 vs 61 mmol·mol−1), associated with lower prevalence of microvascular/macrovascular complications: all‐cause microangiopathy 47% vs 61%; retinopathy 22% vs 34%; all‐cause macroangiopathy 19% vs 31%; and coronary artery disease 6% vs 24% (P < .05).Conclusion[HDL‐C/apoA‐I] can stratify T2DM women according to metabolic phenotype, macrovascular and coronary damage, β‐cell function, microangiopathic risk, and retinopathy. This ratio is a versatile and readily available marker of cardiometabolic status and vascular complications in T2DM women.