bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transition Metal Ion–Mediated Tyrosine‐Based Short‐Peptide Amphiphile Nanostructures Inhibit Bacterial Growth
Authors: Singh Ramesh , Kumar Mishra Narendra , Kumar Vikas , Vinayak Vandana , Ballabh Joshi Khashti 
Published: May 2018

AbstractWe report the design and synthesis of a biocompatible small‐peptide‐based compound for the controlled and targeted delivery of encapsulated bioactive metal ions through transformation of the internal nanostructures of its complexes. A tyrosine‐based short‐peptide amphiphile (sPA) was synthesized and observed to self‐assemble into β‐sheet‐like secondary structures. The self‐assembly of the designed sPA was modulated by application of different bioactive transition‐metal ions, as was confirmed by spectroscopic and microscopic techniques. These bioactive metal‐ion‐conjugated sPA hybrid structures were further used to develop antibacterial materials. As a result of the excellent antibacterial activity of zinc ions the growth of clinically relevant bacteria such as Escherichia coli was inhibited in the presence of zinc⋅sPA conjugate. Bacterial testing demonstrated that, due to high biocompatibility with bacterial cells, the designed sPA acted as a metal ion delivery agent and might therefore show great potential in locally addressing bacterial infections.
Facile Synthesis of Multi‐Ni‐Core@Ni Phyllosilicate@CeO2 Shell Hollow Spheres with High Oxygen Vacancy Concentration for Dry Reforming of CH4
Authors: Li Ziwei , Sibudjing Kawi 
Published: May 2018

AbstractA great challenge for cheap and active Ni‐based catalysts to be utilized for CO2 (dry) reforming of methane (DRM) reaction is their high‐carbon‐deposition problem. Herein, we designed multi‐Ni‐core@Ni phyllosilicate@CeO2 (Ni@NiPhy@CeO2) shell hollow sphere catalysts using a facile precipitation method. Compared with Ni@NiPhy without CeO2 shell, Ni@NiPhy@CeO2 exhibits high carbon resistance for the DRM reaction at both high GHSV value of 1880 L g−1 cat h−1 at 700 °C and a low reaction temperature of 600 °C. In addition, they show high and stable CH4 and CO2 conversions of 72.8 % and 79.1 % respectively at 700 °C under normal GHSV value of 36 L g−1 cat h−1. The good catalytic performance of Ni@NiPhy@CeO2 can be attributed to their high sintering resistance of both Ni and CeO2 which yields a high concentration of oxygen vacancies thereby a high catalytic performance and carbon resistance for DRM reaction. The facile synthesis method in this work can easily be applied to design other core–shell hollow catalysts such as Ni–M (M=Mg, Co, Cu, and Fe) silicate@CeO2 according to specific applications.
Cellulose‐Templated, Dual‐Carbonized Na3V2(PO4)3 for Energy Storage with High Rate Capability
Authors: Sohn DongRak , Ko Jong Wan , Son Eun Jin , Ko Sung Hyun , Kim Tae‐Hee , Kwon HyukSang , Park Chan Beum 
Published: May 2018

AbstractSodium‐ion rechargeable batteries are a promising candidate for large‐scale electrical energy storage systems, owing to the abundance of sodium resources. Herein, we report the development of carbon‐incorporated NASICON‐Na3V2(PO4)3 (NVP) as an active cathode material for Na‐ion batteries, using carboxymethyl cellulose (CMC) and sucrose as dual carbon sources. The interaction between CMC and sucrose resulted in the formation of a highly porous structure (surface area: 58.998 m2 g−1) with increased sp2 carbon species, facilitating mass and charge transportation. The specific capacity (104.99 mAh g−1) of dual‐carbonized CMC/sucrose‐NVP (CS‐NVP) was close to the theoretical capacity (117.6 mAh g−1). Furthermore, dual‐carbonized NVP exhibited stable cyclability, showing a specific capacity of 75.04 mA g−1 even at a high rate of 20 C.
Formation of Twisted β‐Sheet Tapes from a Self‐Complementary Peptide Based on Novel Pillararene‐GCP Host–Guest Interaction with Gene Transfection Properties
Authors: Hu Xiao‐Yu , Ehlers Martin , Wang Tingting , Zellermann Elio , Mosel Stefanie , Jiang Hao , Ostwaldt Jan‐Erik , Knauer Shirley K. , Wang Leyong , Schmuck Carsten 
Published: May 2018

AbstractSmall peptides capable of assembling into well‐defined nanostructures have attracted extensive attention due to their interesting applications as biomaterials. This work reports the first example of a pillararene functionalized with a guanidiniocarbonyl pyrrole (GCP)‐conjugated short peptide segment. The obtained amphiphilic peptide 1 spontaneously self‐assembles into a supramolecular β‐sheet in aqueous solution based on host–guest interaction between pillararene and GCP unit as well as hydrogen‐bonding between the peptide strands. Interestingly, peptide 1 at low concentration shows transitions from small particles to “pearl necklace” assemblies, and finally to branched fibers in a time‐dependent process. At higher concentration, it directly assembles into twisted β‐sheet tapes. Notably, without pillararene moiety, the control peptide A forms α‐helix structure with morphology changing from particles to bamboo‐like assemblies depending on concentration, indicating a significant role of the pillararene‐GCP host‐guest interaction for the secondary structure formation. Moreover, peptide 1 can serve as an efficient gene transfection vector.
The Influence of Binding Site Geometry on Anion‐Binding Selectivity: A Case Study of Macrocyclic Receptors Built on the Azulene Skeleton
Authors: Lichosyt Dawid , Wasiłek Sylwia , Dydio Paweł , Jurczak Janusz 
Published: May 2018

AbstractAn understanding of host–guest noncovalent interactions lies at the very heart of supramolecular chemistry. Often a minute change to the structure of a host molecule's binding site can have a dramatic impact on a prospective host–guest binding event, changing the relative selectivity for potential guest molecules. With the overall goal of aiding the rational design of selective and effective receptors for anions, we have studied the influence of small perturbations in binding site geometry for a series of five closely related 20‐membered macrocyclic tetra‐amide receptors, constructed from two building blocks from a pool of azulene‐5,7‐bisamide, azulene‐1,3‐bisamide, and dipicolinic bisamide units. The solid‐state structures revealed that the conformational preferences of the free receptors are driven by the inherent preferences of the building blocks, yet in some cases the macrocyclic topology is able to over‐ride these to promote pre‐organized conformations favorable for anion binding. The solid‐state structures of the chloride complexes of these receptors revealed that although all the receptors can adapt to binding to the challenging small Cl− guest with all the NH groups, only receptors containing azulene‐5,7‐bisamide units form short and linear, and therefore strong, hydrogen‐bonding interactions. These conclusions are further supported by studies in solution. Although all the receptors showed high affinities toward a series of anions (H2PO4−, PhCO2−, Cl−, and Br−), even in a highly competitive polar medium (DMSO/25 % MeOH), only receptors containing azulene‐5,7‐bisamide units exhibited non‐inherent selectivity for Cl− over PhCO2−, breaking the Hofmeister trend of selectivity. The data presented herein highlight the privileged properties of the azulene‐5,7‐bisamide building block for binding to chloride anions and provide guidelines for the construction of selective and efficient anion receptors with prospective practical applications.
Fluorescent pH‐Responsive Probes Based on Water‐Soluble Boron‐Dipyrromethene (BODIPY) Derivatives, Featuring Long‐Wavelength Emission
Authors: Sutter Alexandra , Elhabiri Mourad , Ulrich Gilles 
Published: May 2018

AbstractWe describe here the synthesis of water‐soluble red/NIR‐emissive, boron‐dipyrromethene (BODIPY) derivatives displaying optical (absorption and emission) responses in pH range of 4–8. Substitution close to the tertiary aniline or the phenol subunits selected as the proton‐sensitive sites allowed us to finely tune the pH ranges. Furthermore, the introduction of sulfobetaine functions at the boron centre of these pH‐responsive BODIPYs afforded valuable fluorescent dyes in the red/NIR region in aqueous media, for which the steric hindrance and electrostatic repulsions prevent their non‐emissive aggregation. All the absorption and emission studies, as well as the protonation properties were investigated in aqueous, ethanolic and saline solutions (mimicking physiological conditions). Interestingly, the systems present a fluorescent ratiometric protonation response in EtOH, but the non‐protonated form is almost a non‐fluorescent species under quasi‐physiological conditions (saline aqueous solutions) due to the fading of the emissive character of the low‐lying charge‐transfer transition in the presence of a supporting electrolyte.
Star‐Shaped Cyanostilbene‐Based Dyads: Synthesis, Self‐Assembly and Photophysical Properties
Authors: Zhao Jing , Chen Weiben , Liu Jingjuan , Guo Hong , Lu Fanli , Chen Long 
Published: May 2018

AbstractThree cyanostilbene‐based π‐conjugated dyads with different aromatic cores (TFB‐CS, TPA‐CS, TPE‐CS) have been designed and synthesized. Distinctive photophysical properties and different self‐assembly behaviors were observed for these dyads. For example, TPA‐CS exhibits pronounced solvent‐dependent fluorescence. TFB‐CS presents clear photoinduced Z/E‐isomerization of the cyanostilbene moiety upon UV irradiation, concomitant with dramatically increased emission. While TPE‐CS showcases pronounced aggregation‐induced emission enhancement phenomenon. Moreover, different architectures of the three dyads such as nanospheres and microwires could be easily obtained by solution processing. We demonstrate here a facile “two in one” strategy of integrating different chromophores in one molecule to explore novel organic functional materials.
Blowup Solutions to the Semilinear Wave Equation with a Stylized Pyramid as a Blowup Surface
Authors: Merle Frank , Zaag Hatem 
Published: May 2018

AbstractWe consider the semilinear wave equation with subconformal power nonlinearity in two space dimensions. We construct a finite‐time blowup solution with an isolated characteristic blowup point at the origin and a blowup surface that is centered at the origin and has the shape of a stylized pyramid, whose edges follow the bisectrices of the axes in ℝ2. The blowup surface is differentiable outside the bisectrices. As for the asymptotic behavior in similarity variables, the solution converges to the classical one‐dimensional soliton outside the bisectrices. On the bisectrices outside the origin, it converges (up to a subsequence) to a genuinely two‐dimensional stationary solution, whose existence is a by‐product of the proof. At the origin, it behaves like the sum of four solitons localized on the two axes, with opposite signs for neighbors.This is the first example of a blowup solution with a characteristic point in higher dimensions, showing a really two‐dimensional behavior. Moreover, the points of the bisectrices outside the origin give us the first example of noncharacteristic points where the blowup surface is nondifferentiable. © 2018 Wiley Periodicals, Inc.
Efficient Adsorption Characteristics of Pristine and Silver‐Doped Graphene Oxide Towards Contaminants: A Potential Membrane Material for Water Purification?
Authors: Panigrahi Puspamitra , Dhinakaran Ashok Kumar , Sekar Yuvaraj , Ahuja Rajeev , Hussain Tanveer 
Published: May 2018

AbstractIn this work, we have investigated the potential of pristine and silver (Ag)‐functionalized graphene oxide monolayers GO (GO−Ag) as efficient membranes for water filtration. Our first principles calculations based on density functional theory (DFT) reveal the hydrophilic nature of GO surfaces. The phonon frequency calculations within density functional perturbation theory (DFPT) confirmed the stability of GO sheets in aqueous media. Van der Waals‐corrected binding energies of GO sheet towards heavy metals suggest that even pristine GO sheets are completely impermeable to various heavy metals like arsenic (As) and lead (Pb). However, compared to GO, the GO−Ag sheets have a much higher affinity towards the three amino acids histidine, phenyl‐alanine and tyrosine, which are the main component of a bacteria cell wall. The GO−Ag sheet is found to be extremely efficient for bacteria inactivation.
Exploiting Photochemical Processes in Multi‐Step Continuous Flow: Derivatization of the Natural Product Clausine C
Authors: Parisien‐Collette Shawn , Collins Shawn K. 
Published: May 2018

AbstractThe synthesis and derivatization of carbazoles based upon the natural product clausine C has been accomplished using two different two‐step continuous processes. The resulting carbazoles (9 examples, 33–74 % yield) were prepared by means of a continuous flow set‐up integrating a UV‐mediated transformation employing a purple LED reactor (λ=394 nm) as the first step in the multi‐step sequence. The second derivatization step involved cross‐coupling through Pd‐catalyzed Suzuki cross‐coupling or Ni‐catalyzed metallophotoredox cross‐coupling with potassium trifluoroborate salts. The latter represents the first example of using sequential photochemical reactors, at different wavelengths, in a continuous flow process.
A resource‐tuned QoS multicast routing protocol
Authors: Sheikh W. 
Published: May 2018

SummaryThis paper presents a novel framework for quality‐of‐service (QoS) multicast routing with resource allocation that represents QoS parameters, jitter delay, and reliability, as functions of adjustable network resources, bandwidth, and buffer, rather than static metrics. The particular functional form of QoS parameters depends on rate‐based service disciplines used in the routers. This allows intelligent tuning of QoS parameters as functions of allocated resources during the multicast tree search process, rather than decoupling the tree search from resource allocation. The proposed framework minimizes the network resource utilization while keeping jitter delay, reliability, and bandwidth bounded. This definition makes the proposed QoS multicast routing with resource allocation problem more general than the classical minimum Steiner tree problem. As an application of our general framework, we formulate the QoS multicast routing with resource allocation problem for a network consisting of generalized processor sharing nodes as a mixed‐integer quadratic program and find the optimal multicast tree with allocated resources to satisfy the QoS constraints. We then present a polynomial‐time greedy heuristic for the QoS multicast routing with resource allocation problem and compare its performance with the optimal solution of the mixed‐integer quadratic program. The simulation results reveal that the proposed heuristic finds near‐optimal QoS multicast trees along with important insights into the interdependency of QoS parameters and resources.
Numerical electric field analysis of capacitance and potential in space for estimation of permittivity distribution
Authors: Yamanobe Hiroshi , Ohchi Masashi 
Published: May 2018

AbstractWe have been studying on measuring capacitance and potential using long‐distance electrode for estimating a permittivity distribution. The estimating method of permittivity distribution was proposed using finite element method (FEM) and genetic algorithm. However, the measurement accuracy was not reviewed. In this paper, we carried out numerical analysis using FEM in case of change of diameter, position, and permittivity of a rod of dielectric and discussed the measurement accuracy of capacitance and potential.
Polyphosphazenes – Synthetically Versatile Block Copolymers (“Multi‐Tool”) for Self‐Assembly
Authors: Carriedo Gabino A. , de la Campa Raquel , Soto Alejandro Presa 
Published: May 2018

AbstractInvited for the cover of this issue is the group of AlejandroàPresa Soto from Universidad de Oviedo, Spain. The cover image shows the synthesis of polyphosphazene block copolymers and the nanostructured morphologies created by their self‐assembly.
Quality of life after spinal cord injury: The impact of pain
Authors: Burke D. , Lennon O. , Fullen B.M. 
Published: May 2018

AbstractBackgroundPain is a common complication after spinal cord injury (SCI). A mixture of nociceptive and neuropathic pain (NP) can present. Limited studies have investigated the impact of different pain phenotypes on quality of life (QoL) post‐SCI.MethodsMembers registered to a national support group for those with SCIs were surveyed (n = 1574). The survey comprised questions relating to demographics and SCI characteristics, The Douleur Neuropathique 4 (DN4) (interview), the International SCI Pain Basic Data Set recording the worst pain and the World Health Organisation Quality of Life BREF (WHOQOL‐BREF). An ANCOVA model with post hoc analysis explored between group factors of pain type and intensity of pain categories on QoL, controlling for additional confounding variables. Significance was set p < 0.05. A linear regression explored whether pain intensity, type or interference best predicted QoL.ResultsThe response rate was 41% (n = 643), 70% (n = 447) were male. The mean age of respondents was 52 years (SD 14.2) and mean time from SCI was 17 years (SD 12.4). In the previous week, 71% (n = 458) experienced pain, 37% (n = 236) of which had NP as defined in the study. Respondents experiencing NP demonstrated significantly poorer QoL than those without pain (p < 0.001) or nociceptive pain (p < 0.05). Those reporting high pain intensity had significantly lower QoL than those with moderate or no pain (p < 0.001). Pain interference consistently and best‐predicted domains of QoL (p < 0.001).ConclusionHigh‐intensity pain and NP negatively impacts QoL post‐SCI. However pain interference more than intensity or type best explains the variance in QoL reported.SignificanceNeuropathic pain type and severe pain intensities negatively impact QoL after SCI. Pain interference items better predict reported QoL than either pain type or intensity, suggesting better pain management strategies are warranted.
An accurate bacterial DNA quantification assay for HTS library preparation of human biological samples
Authors: Seashols‐Williams Sarah , Green Raquel , Wohlfahrt Denise , Brand Angela , Tan‐Torres Antonio Limjuco , Nogales Francy , Brooks J Paul , Singh Baneshwar 
Published: May 2018

AbstractSequencing and classification of microbial taxa within forensically relevant biological fluids has the potential for applications in the forensic science and biomedical fields. The quantity of bacterial DNA from human samples is currently estimated based on quantity of total DNA isolated. This method can miscalculate bacterial DNA quantity due to the mixed nature of the sample, and consequently library preparation is often unreliable. We developed an assay that can accurately and specifically quantify bacterial DNA within a mixed sample for reliable 16S ribosomal DNA (16S rDNA) library preparation and high throughput sequencing (HTS). A qPCR method was optimized using universal 16S rDNA primers, and a commercially available bacterial community DNA standard was used to develop a precise standard curve. Following qPCR optimization, 16S rDNA libraries from saliva, vaginal and menstrual secretions, urine, and fecal matter were amplified and evaluated at various DNA concentrations; successful HTS data were generated with as low as 20 pg of bacterial DNA. Changes in bacterial DNA quantity did not impact observed relative abundances of major bacterial taxa, but relative abundance changes of minor taxa were observed. Accurate quantification of microbial DNA resulted in consistent, successful library preparations for HTS analysis.
The glacial landsystem of a tropical glacier: Charquini Sur, Bolivian Andes
Authors: Małecki Jakub , Lovell Harold , Ewertowski Wojciech , Górski Łukasz , Kurczaba Tomasz , Latos Beata , Miara Michał , Piniarska Dorota , Płocieniczak Jacek , Sowada Tomasz , Spiralski Marcin , Warczachowska Anna , Rabatel Antoine 
Published: May 2018

AbstractThe geomorphological signature of tropical glaciers has the potential to provide important information on the response of ice masses in high‐mountain environments to climate warming. This study investigates the glacial geomorphology of Charquini Sur, Bolivia. Detailed geomorphological mapping was conducted both in the field and from satellite imagery in order to produce a 1:4000 scale geomorphological map of the glacier foreland. Sedimentological analyses (description of physical characteristics, clast shape and roundness, particle‐size distribution) provided additional insight into the landform–sediment assemblage. Glacial landforms are well preserved and include up to 11 moraine ridge suites, seven of which are cross‐valley frontal moraine arcs. These can be linked to an existing lichenometric chronology from previous work and record glacier recession since the local Little Ice Age (LIA) maximum in the late‐1600s. Lateral moraine ridges also record continuous thinning of the glacier over this time period. Smaller groups of parallel ridges are interpreted as annual moraines formed during recession. Intermorainic areas consist of flutings and a typically thin sediment cover of subglacial, supraglacial and glaciofluvial origin, with prominent ice‐moulded bedrock protuberances in places. Analysis of the landform–sediment assemblage provides an insight into the main controls on landform genesis in the basin and implies there have been temporal changes in ice‐marginal dynamics since the LIA. We present the first landsystem model for a tropical cirque glacier, documenting its behaviour since the LIA and providing an indication of glacier response in rapidly‐warming high‐mountain environments. Copyright © 2018 John Wiley & Sons, Ltd.
Food preservation by Larrea divaricata extract: participation of polyphenols
Authors: Peralta Ignacio , Marrassini Carla , Filip Rosana , Alonso Maria R. , Anesini Claudia 
Published: May 2018

AbstractThe aim of this study was to evaluate the antioxidant and protease inhibitor capacities on eggs and milk protein of a nor‐dihydroguaiaretic (NDGA)‐standardized aqueous extract of Larrea divaricata (AE) and to analyze the participation of polyphenols as NDGA in these actions. NDGA was determined by high‐performance liquid chromatography; flavonoids and polyphenols were quantified by spectrophotometric methods as well as inhibition of lipid peroxidation, proteinase inhibitor capacity, advanced glycation end products (AGES) formation, and inhibition of albumin denaturation. The extract protected food for oxidative damage by preventing malondialdehyde formation in egg yolk and by preventing AGE formation in completely cooked eggs, also impeded albumin denaturation, and casein hydrolysis induced by trypsin and heat. Polyphenols, especially flavonoids and NDGA, were involved in these actions.