bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ag2 and Ag3 Clusters: Synthesis, Characterization, and Interaction with DNA
Authors: Buceta David , Busto Natalia , Barone Giampaolo , Leal José M. , Domínguez Fernando , Giovanetti Lisandro J. , Requejo Félix G. , García Begoña , López‐Quintela M. Arturo 
Published: May 2015

AbstractSubnanometric samples, containing exclusively Ag2 and Ag3 clusters, were synthesized for the first time by kinetic control using an electrochemical technique without the use of surfactants or capping agents. By combination of thermodynamic and kinetic measurements and theoretical calculations, we show herein that Ag3 clusters interact with DNA through intercalation, inducing significant structural distortion to the DNA. The lifetime of Ag3 clusters in the intercalated position is two to three orders of magnitude longer than for classical organic intercalators, such as ethidium bromide or proflavine.
Pseudohalide‐Induced Moisture Tolerance in Perovskite CH3NH3Pb(SCN)2I Thin Films
Authors: Jiang Qinglong , Rebollar Dominic , Gong Jue , Piacentino Elettra L. , Zheng Chong , Xu Tao 
Published: May 2015

AbstractTwo pseudohalide thiocyanate ions (SCN−) have been used to replace two iodides in CH3NH3PbI3, and the resulting perovskite material was used as the active material in solar cells. In accelerated stability tests, the CH3NH3Pb(SCN)2I perovskite films were shown to be superior to the conventional CH3NH3PbI3 films as no significant degradation was observed after the film had been exposed to air with a relative humidity of 95 % for over four hours, whereas CH3NH3PbI3 films degraded in less than 1.5 hours. Solar cells based on CH3NH3Pb(SCN)2I thin films exhibited an efficiency of 8.3 %, which is comparable to that of CH3NH3PbI3 based cells fabricated in the same way.
Synthesis of poly(butyl acrylate‐co‐methyl methacrylate)/montmorillonite waterborne nanocomposite via semibatch emulsion polymerization
Authors: Vatansever Alican , Inan Tulay Y. , Dogan Hacer , Sirkecioglu Ahmet 
Published: May 2015

ABSTRACTPoly(butyl acrylate‐co‐methyl methacrylate)‐montmorillonite (MMT) waterborne nanocomposites were successfully synthesized by semibatch emulsion polymerization. The syntheses of the nanocomposites were performed in presence of sodium montmorillonite (Na‐MMT) and organically modified montmorillonite (O‐MMT). O‐MMT was used directly after the modification of Na‐MMT with dimethyl dioctadecyl ammonium chloride. Both Na‐MMT and O‐MMT were sonified to obtain nanocomposites with 47 wt % solids and 3 wt % Na‐MMT or O‐MMT content. Average particle sizes of Na‐MMT nanocomposites were measured as 110–150 nm while O‐MMT nanocomposites were measured as 200–350 nm. Both Na‐MMT and O‐MMT increased thermal, mechanical, and barrier properties (water vapor and oxygen permeability) of the pristine copolymer explicitly. X‐ray diffraction and transmission electron microscope studies show that exfoliated morphology was obtained. The gloss values of O‐MMT nanocomposites were found to be higher than that of the pristine copolymer. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42373.
Unlocking Inter‐ to Non‐Penetrating Frameworks Using Steric Influences on Spacers for CO2 Adsorption
Authors: Huang Sheng‐Li , Zhang Wen‐Hua , Ling Yun , Ng Seik Weng , Luo He‐Kuan , Hor T. S. Andy 
Published: May 2015

AbstractFour porous coordination networks have been synthesized from 1,4‐benzenedicarboxylate with Cl, Br, I, and NO2 substituents whose different spatial differences are sufficient to influence the coordination mode of adjacent carboxyl moieties to unlock an inter‐penetrating framework to give isostructural structures. Their size and polarity differences account for the diverging CO2 adsorption performances.
Antiparallel Self‐Association of a γ,α‐Hybrid Peptide: More Relevance of Weak Interactions
Authors: Venugopalan Paloth , Kishore Raghuvansh 
Published: May 2015

AbstractTo learn how a preorganized peptide‐based molecular template, together with diverse weak non‐covalent interactions, leads to an effective self‐association, we investigated the conformational characteristics of a simple γ,α‐hybrid model peptide, Boc‐γ‐Abz‐Gly‐OMe. The single‐crystal X‐ray diffraction analysis revealed the existence of a fully extended β‐strand‐like structure stabilized by two non‐conventional C−H⋅⋅⋅O=C intramolecular H‐bonds. The 2D 1H NMR ROESY experiment led us to propose that the flat topology of the urethane‐γ‐Abz‐amide moiety is predominantly preserved in a non‐polar environment. The self‐association of the energetically more favorable antiparallel β‐strand‐mimic in solid‐state engenders an unusual ‘flight of stairs’ fabricated through face‐to‐face and edge‐to‐edge Ar⋅⋅⋅Ar interactions. In conjunction with FT‐IR spectroscopic analysis in chloroform, we highlight that conformationally semi‐rigid γ‐Abz foldamer in appositely designed peptides may encourage unusual β‐strand or β‐sheet‐like self‐association and supramolecular organization stabilized via weak attractive forces.
Review cyclic peptides on a merry‐go‐round; towards drug design
Authors: Tapeinou Anthi , Matsoukas Minos‐Timotheos , Simal Carmen , Tselios Theodore 
Published: May 2015

ABSTRACTPeptides and proteins are attractive initial leads for the rational design of bioactive molecules. Several natural cyclic peptides have recently emerged as templates for drug design due to their resistance to chemical or enzymatic hydrolysis and high selectivity to receptors. The development of practical protocols that mimic the power of nature's strategies remains paramount for the advancement of novel peptide‐based drugs. The de novo design of peptide mimetics (nonpeptide molecules or cyclic peptides) for the synthesis of linear or cyclic peptides has enhanced the progress of therapeutics and diverse areas of science and technology. In the case of metabolically unstable peptide ligands, the rational design and synthesis of cyclic peptide analogues has turned into an alternative approach for improved biological activity. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 104: 453–461, 2015.
Self‐assembled penetratin‐deferasirox micelles as potential carriers for hydrophobic drug delivery
Authors: Goswami Dibakar , Vitorino Hector Aguilar , Machini M. Teresa , Espósito Breno P. 
Published: May 2015

ABSTRACTThere has been a growing interest in the use of micelles with nanofiber geometry as nanocarriers for hydrophobic drugs. Here we show that the conjugate of penetratin, a cell‐penetrating peptide (CPP) with blood‐brain barrier (BBB) permeability, and deferasirox (DFX), a hydrophobic iron chelator, self‐assembles to form micelles at a very low concentration (∼15 mg/L). The critical micelle concentration (CMC) was determined, and the micelles were used for solubilizing curcumin, a hydrophobic anti‐neurodegenerative drug, for successful delivery across RBE4 cells, a BBB model. Transmission Electron Microscope images of the curcumin‐loaded micelles confirmed the formation of nanofibers. These results indicate the potential of CPP‐drug conjugates for use as nanocarriers. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 104: 712–719, 2015.
Bone marrow‐derived stromal cells are more beneficial cell sources for tooth regeneration compared with adipose‐derived stromal cells
Authors: Ye Lanfeng , Chen Lin , Feng Fan , Cui Junhui , Li Kaide , Li Zhiyong , Liu Lei 
Published: May 2015

AbstractTooth loss is presently a global epidemic and tooth regeneration is thought to be a feasible and ideal treatment approach. Choice of cell source is a primary concern in tooth regeneration. In this study, the odontogenic differentiation potential of two non‐dental‐derived stem cells, adipose‐derived stromal cells (ADSCs) and bone marrow‐derived stromal cells (BMSCs), were evaluated both in vitro and in vivo. ADSCs and BMSCs were induced in vitro in the presence of tooth germ cell‐conditioned medium (TGC‐CM) prior to implantation into the omentum majus of rats, in combination with inactivated dentin matrix (IDM). Real‐time quantitative polymerase chain reaction (RT‐qPCR) was used to detect the mRNA expression levels of odontogenic‐related genes. Immunofluorescence and immunohistochemical assays were used to detect the protein levels of odontogenic‐specific genes, such as DSP and DMP‐1 both in vitro and in vivo. The results suggest that both ADSCs and BMSCs have odontogenic differentiation potential. However, the odontogenic potential of BMSCs was greater compared with ADSCs, showing that BMSCs are a more appropriate cell source for tooth regeneration.
Triply Hydrogen‐Bond‐Directed Enantioselective Assembly of Pyrrolobenzo‐1,4‐diazine Skeletons with Quaternary Stereocenters
Authors: Shen Xiaoming , Wang Yongtao , Wu Tiandi , Mao Zhenjun , Lin Xufeng 
Published: May 2015

AbstractHighly efficient synthesis of optically enriched pyrrolobenzo‐1,4‐diazines bearing quaternary stereocenters has been realized through the chiral Brønsted acid‐catalyzed Pictet–Spengler reaction of 2‐(1H‐pyrrol‐1‐yl)anilines and α‐ketoamides in good to excellent yields and enantioselectivities. Computational studies suggest an unprecedented phenomenon whereby the chiral phosphoric acid catalyst employs attractive arene CH⋅⋅⋅N hydrogen bonding to activate the substrate and induce chirality through a triple hydrogen‐bonding interaction.
Catalytic Enantioselective Reaction of α‐Phenylthioacetonitriles with Imines Using Chiral Bis(imidazoline)–Palladium Catalysts
Authors: Kondo Masaru , Kobayashi Natsumi , Hatanaka Tsubasa , Funahashi Yasuhiro , Nakamura Shuichi 
Published: May 2015

AbstractThe catalytic enantioselective reaction of α‐phenylthioacetonitriles with imines has been developed. The reaction of various imines proceeds in good yields and diastereo‐ and enantioselectivities in the presence of chiral bis(imidazoline)–palladium catalysts. The obtained products can be converted into β‐aminonitrile or β‐aminoamide compounds without loss of enantiopurity.
Influence of ageing on the gloss, color, and structure of colored ABS
Authors: Bociąga Elżbieta , Trzaskalska Milena 
Published: May 2015

AbstractThe results of examination of the influence of ageing by UV rays on the gloss, color, and morphology of injection molded parts made of ABS terpolymer with addition of coloring agents in the form of powder and its masterbatch (granulate) based on ABS and PS media are presented in this article. It has been shown that the UV radiation contributes to decrease in the value of gloss and increase in the luminance of moldings and also changes values of parameters a and b, describing the change in parts color, in the direction of red and yellow, which is connected with the degradation of polymer ABS and coloring agents. Ageing process leads to structural changes in polymer, depending on the type of coloring agent. © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 392–398, 2016
Interference colorimetry of starch granules
Authors: Swatland H. J. 
Published: May 2015

AbstractStarch granules viewed under a polarizing microscope may exhibit vivid interference colors – how can they be measured? A tilting compensator was used to generate interference colors, they were measured by spectrophotometry (400–700 nm at 10 nm intervals), and the weighted ordinate method was used to calculate chromaticity coordinates. There was a reasonable correspondence between the subjective terms used to describe interference colors, and those used for the CIE diagram. Three different charts of interference colors were measured by fiber‐optics – only one was close to the interference colors of the tilting compensator (r = 0.805 for CIE x, and r = 0.874 for CIE y, both P < 0.005). The spectra of various interference colors were like sine waves, whereas the matching spectra from charts were irregular with occasional peaks or dips. Thus, radically different spectra shared very similar chromaticity coordinates. As anticipated from first principles, the diameter of starch granules had a strong effect on their chromaticity coordinates (from r = 0.78 to r = 0.87, all P < 0.001). © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 352–357, 2016
Self‐Supporting Metal Nanotube Networks Obtained by Highly Conformal Electroless Plating
Authors: Muench Falk , De Carolis Dario M. , Felix Eva‐Maria , Brötz Joachim , Kunz Ulrike , Kleebe Hans‐Joachim , Ayata Sevda , Trautmann Christina , Ensinger Wolfgang 
Published: May 2015

AbstractWe present a versatile approach for the fabrication of well‐defined networks of interconnected metal nanotubes, which applies electroless plating to ion‐track‐etched polymer templates that enclose designed pore networks. In order to obtain self‐supporting structures, the deposition reactions must be optimized to yield conformal nanoscale metal films on microstructured substrates possessing extensive inner surfaces. Using this route, gold, copper, silver, nickel, and platinum nanotube networks are synthesized. The resulting structures can be handled macroscopically and combine a large surface area with continuous mass transport and conduction pathways, rendering them promising for application in, for example, electrocatalysis and sensing. This potential is demonstrated by employing a gold nanotube network for the amperometric detection of hydrogen peroxide, in which excellent sensitivity, catalyst utilization, and stability is achieved.
Capacitive Deionization using Biomass‐based Microporous Salt‐Templated Heteroatom‐Doped Carbons
Authors: Porada Slawomir , Schipper Florian , Aslan Mesut , Antonietti Markus , Presser Volker , Fellinger Tim‐Patrick 
Published: May 2015

AbstractMicroporous carbons are an interesting material for electrochemical applications. In this study, we evaluate several such carbons without/with N or S doping with regard to capacitive deionization. For this purpose, we extent the salt‐templating synthesis towards biomass precursors and S‐doped microporous carbons. The sample with the largest specific surface area (2830 m2 g−1) showed 1.0 wt % N and exhibited a high salt‐sorption capacity of 15.0 mg g−1 at 1.2 V in 5 mM aqueous NaCl. While being a promising material from an equilibrium performance point of view, our study also gives first insights to practical limitations of heteroatom‐doped carbon materials. We show that high heteroatom content may be associated with a low charge efficiency. The latter is a key parameter for capacitive deionization and is defined as the ratio between the amounts of removed salt molecules and electrical charge.
Towards Stronger Coulomb Coupling in an Ultracold Neutral Plasma
Authors: Lyon M. , Bergeson S. D. 
Published: May 2015

AbstractUltracold neutral plasmas are strongly coupled Coulomb systems that are generated by photoionizing lasercooled atoms close to the ionization threshold. The strong coupling parameter Γ is limited at times later than ∼100 ns by disorder‐induced heating. A recent simulation predicted that higher values of Γ can be realized in ultracold neutral plasmas if the plasma ions are excited to higher ionization states. In this paper we present recent results from an experiment that increases the strong coupling of an ultracold neutral plasma by promoting the plasma ions to the second ionization state. Using laser‐induced fluorescence we map out the ion velocity distribution of the Ca+ ions in a partially doubly ionized plasma and show that the heating due to the second ionization depends on the timing of the second ionization laser pulses. We compare our results to MD simulations, which estimate that Γ increases from approximately 2.5 to 3.6. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantum Hydrodynamics for Plasmas – a Thomas‐Fermi Theory Perspective
Authors: Michta D. , Graziani F. , Bonitz M. 
Published: May 2015

AbstractThe idea to describe quantum systems within a hydrodynamic framework (quantum hydrodynamics, QHD) goes back to Madelung and Bohm. While such a description is formally exact for a single particle, more recently the concept has been applied to many‐particle systems by Manfredi and Haas [Phys. Rev. B 64, 075316 (2001)] and received high popularity in parts of the quantum plasma community. Thereby, often the applicability limits of these equations are ignored, giving rise to unphysical predictions. Here we demonstrate that modified QHD equations for plasmas can be derived from Thomas‐Fermi theory including gradient corrections. This puts QHD on firm grounds. At the same time this derivation yields a different prefactor, γ = (D – 2/3D), in front of the quantum (Bohm) potential which depends on the system dimensionality D. Our approach allows one to identify the limitations of QHD and to outline systematic improvements. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Chick embryos have the same pattern of hypoxic lower‐brain activation as fetal mammals
Authors: Landry Jeremy P. , Hawkins Connor , Lee Aaron , Coté Alexandra , Balaban Evan , Pompeiano Maria 
Published: May 2015

ABSTRACTcFos expression (indicating a particular kind of neuronal activation) was examined in embryonic day (E) 18 chick embryos after exposure to 4 h of either normoxia (21% O2), modest hypoxia (15% O2), or medium hypoxia (10% O2). Eight regions of the brainstem and hypothalamus were surveyed, including seven previously shown to respond to hypoxia in late‐gestation mammalian fetuses (Breen et al., 1997; Nitsos and Walker, 1999b). Hypoxia‐related changes in chick embryo brain activation mirrored those found in fetal mammals with the exception of the medullary Raphe, which showed decreased hypoxic activation, compared with no change in mammals. This difference may be explained by the greater anapyrexic responses of chick embryos relative to mammalian fetuses. Activation in the A1/C1 region was examined in more detail to ascertain whether an O2‐sensitive subpopulation of these cells containing heme oxygenase 2 (HMOX2) may drive hypoxic brain responses before the maturation of peripheral O2‐sensing. HMOX2‐positive and ‐negative catecholaminergic cells and interdigitating noncatecholaminergic HMOX2‐positive cells all showed significant changes in cFos expression to hypoxia, with larger population responses seen in the catecholaminergic cells. Hypoxia‐induced activation of lower‐brain regions studied here was significantly better correlated with activation of the nucleus of the solitary tract (NTS) than with that of HMOX2‐containing A1/C1 neurons. Together, these observations suggest that (1) the functional circuitry controlling prenatal brain responses to hypoxia is strongly conserved between birds and mammals, and (2) NTS neurons are a more dominant driving force for prenatal hypoxic cFos brain responses than O2‐sensing A1/C1 neurons. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 64–74, 2016
Development of diagnostic microsatellite markers from whole‐genome sequences ofAmmodramussparrows for assessing admixture in a hybrid zone
Authors: Kovach Adrienne I. , Walsh Jennifer , Ramsdell Jordan , Kelley Thomas W. 
Published: May 2015

AbstractStudies of hybridization and introgression and, in particular, the identification of admixed individuals in natural populations benefit from the use of diagnostic genetic markers that reliably differentiate pure species from each other and their hybrid forms. Such diagnostic markers are often infrequent in the genomes of closely related species, and genomewide data facilitate their discovery. We used whole‐genome data from Illumina HiSeqS2000 sequencing of two recently diverged (600,000 years) and hybridizing, avian, sister species, the Saltmarsh (Ammodramus caudacutus) and Nelson's (A. nelsoni) Sparrow, to develop a suite of diagnostic markers for high‐resolution identification of pure and admixed individuals. We compared the microsatellite repeat regions identified in the genomes of the two species and selected a subset of 37 loci that differed between the species in repeat number. We screened these loci on 12 pure individuals of each species and report on the 34 that successfully amplified. From these, we developed a panel of the 12 most diagnostic loci, which we evaluated on 96 individuals, including individuals from both allopatric populations and sympatric individuals from the hybrid zone. Using simulations, we evaluated the power of the marker panel for accurate assignments of individuals to their appropriate pure species and hybrid genotypic classes (F1, F2, and backcrosses). The markers proved highly informative for species discrimination and had high accuracy for classifying admixed individuals into their genotypic classes. These markers will aid future investigations of introgressive hybridization in this system and aid conservation efforts aimed at monitoring and preserving pure species. Our approach is transferable to other study systems consisting of closely related and incipient species.
Throughput, energy efficiency and interference characterisation of 802.11ac
Authors: Zeng Yunze , Pathak Parth H. , Mohapatra Prasant 
Published: May 2015

AbstractThis paper is the first of its kind in presenting a detailed characterisation of IEEE 802.11ac using real experiments. 802.11ac is the latest Wireless Local Area Network (WLAN) standard that is rapidly being adapted because of its potential to deliver very high throughput. The throughput increase in 802.11ac can be attributed to three factors—larger channel width (80/160 MHz), support for denser modulation (256 Quadrature Amplitude Modulation (QAM)) and increased number of spatial streams for Multiple‐input Multiple‐output (MIMO). We provide an experiment evaluation of these factors and their impact using a real 802.11ac testbed. Our findings provide numerous insights on benefits and challenges associated with using 802.11ac in practice.Because utilisation of larger channel width is one of the most significant changes in 802.11ac, we focus our study on understanding its impact on energy efficiency and interference. Using experiments, we show that utilising larger channel width is in general less energy efficient because of its higher power consumption in idle listening mode. Increasing the number of MIMO spatial streams is comparatively more energy efficient for achieving the same percentage increase in throughput. We also show that 802.11ac link witnesses severe unfairness issues when it coexists with legacy 802.11. We provide a detailed analysis to show how medium access in heterogeneous channel width environment leads to the unfairness issues. We believe that these and many other findings presented in this work will help in understanding and resolving various performance issues of next generation WLANs. Copyright © 2015 John Wiley & Sons, Ltd.
The taste enhancer divanillin: a review on sources and enzymatic generation
Authors: Krings Ulrich , Esparan Vida , Berger Ralf G. 
Published: May 2015

AbstractDehydrodivanillin, the symmetrical dimer of vanillin, is a taste enhancer which imparts pleasant impressions of creaminess to food. Found in vanilla pods in traces only, a co‐substrate independent dimerization of vanillin, conducted in a co‐solvent system to improve the solubility of vanillin, was developed using iso‐active fungal laccases from Meripilus giganteus, Agaricus bisporus and Funalia trogii. The yields were compared with a peroxidase from Marasmius scorodonius (MsP2) and the reference enzyme horseradish peroxidase (HRP), both supplied with hydrogen peroxide. Using laccase catalysis, the kinetically preferred reaction product, 5,5'‐dehydrodivanillin, rapidly reached saturation and precipitated in situ, thus shifting the reaction equilibrium to the product. Yields of > 95 % were obtained with the high‐redox‐potential laccase of Funalia trogii, while HRP gave 18 %. Copyright © 2015 John Wiley & Sons, Ltd.