bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of fumarates on inflammatory human astrocyte responses and oligodendrocyte differentiation
Authors: Galloway Dylan A. , Williams John B. , Moore Craig S.
Published: May 2017

Objective

Dimethyl fumarate (DMF) is a fumaric acid ester approved for the treatment of relapsing‐remitting multiple sclerosis (RRMS). In both the brain and periphery, DMF and its metabolite monomethyl fumarate (MMF) exert anti‐inflammatory and antioxidant effects. Our aim was to compare the effects of DMF and MMF on inflammatory and antioxidant pathways within astrocytes, a critical supporting glial cell in the central nervous system (CNS). Direct effects of fumarates on neural progenitor cell (NPC) differentiation toward the oligodendrocyte lineage were also assessed.

Methods

Primary astrocyte cultures were derived from both murine and human brains. Following pretreatment with MMF, DMF, or vehicle, astrocytes were stimulated with IL‐1β for 24 h; gene and microRNA expression were measured by qPCR. Cytokine production and reactive oxygen species (ROS) generation were also measured. NPCs were differentiated into the oligodendrocyte lineage in the presence of fumarates and immunostained using early oligodendrocyte markers.

Results

In both murine and human astrocytes, DMF, but not MMF, significantly reduced secretion of IL‐6, CXCL10, and CCL2; neither fumarate promoted a robust increase in antioxidant gene expression, although both MMF and DMF prevented intracellular ROS production. Pretreatment with fumarates reduced microRNAs ‐146a and ‐155 upon stimulation. In NPC cultures, DMF increased the number of O4+ and NG2+ cells.

Interpretation

These results suggest that DMF, and to a lesser extent MMF, mediates the anti‐inflammatory effects within astrocytes. This is supported by recent observations that in the inflamed CNS, DMF may be the active compound mediating the anti‐inflammatory effects independent from altered antioxidant gene expression.
Engineering Large Anisotropic Magnetoresistance in La0.7Sr0.3MnO3 Films at Room Temperature
Authors: Perna Paolo , Maccariello Davide , Ajejas Fernando , Guerrero Ruben , Méchin Laurence , Flament Stephane , Santamaria Jacobo , Miranda Rodolfo , Camarero Julio
Published: May 2017

The magnetoresistance (MR) effect is widely used in technologies that pervade the world, from magnetic reading heads to sensors. Diverse contributions to MR, such as anisotropic, giant, tunnel, colossal, and spin‐Hall, are revealed in materials depending on the specific system and measuring configuration. Half‐metallic manganites hold promise for spintronic applications but the complexity of competing interactions has not permitted the understanding and control of their magnetotransport properties to enable the realization of their technological potential. This study reports on the ability to induce a dominant switchable magnetoresistance in La0.7Sr0.3MnO3 epitaxial films at room temperature (RT). By engineering an extrinsic magnetic anisotropy, a large enhancement of anisotropic magnetoresistance (AMR) is achieved which at RT leads to signal changes much larger than the other contributions such as the colossal magnetoresistance. The dominant extrinsic AMR exhibits large variation in the resistance in low field region, showing high sensitivity to applied low magnetic fields. These findings have a strong impact on the real applications of manganite‐based devices for the high‐resolution low field magnetic sensors or spintronics.
Two‐Step Enzymatic Synthesis of β‐d‐N‐Acetylgalactosamine‐(1→4)‐d‐N‐acetylglucosamine (LacdiNAc) Chitooligomers for Deciphering Galectin Binding Behavior
Authors: Laaf Dominic , Bojarová Pavla , Mikulová Barbora , Pelantová Helena , Křen Vladimír , Elling Lothar
Published: May 2017

A two‐step synthesis of engineered variants of Talaromyces flavus β‐N‐acetylhexosaminidase (TfHexY470N) and human β4‐galactosyltransferase (β4GalTY284L) yielded complex glycans comprising a chitooligomeric spacer (β1,4GlcNAc)n=0–3 terminated with a β4‐linked β‐d‐N‐acetylgalactosamine‐(1→4)‐d‐N‐acetylglucosamine (LacdiNAc) epitope. These compounds are novel inhibitors of human galectin‐3 (Gal‐3), a widely spread animal lectin with important physiological functions in cellular communication. The multivalent presentation of glycan oligomers was accomplished by chemical conjugation of glycans to lysine residues of bovine serum albumin (BSA). Binding studies of Gal‐3 to immobilized BSA neo‐glycoconjugates revealed the beneficial influence of the chitooligomeric spacer for the ligand‐lectin affinity. We conclude that the use of the (β1,4GlcNAc)n=0–3 spacer is a perfect nature‐like solution for the presentation of elaborated Gal‐3 glycan epitopes that surpasses the performance of commonly used synthetic spacers.

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Can we Build on Social Movement Theories to Develop and Improve Community‐Based Participatory Research? A Framework Synthesis Review
Authors: Tremblay Marie‐Claude , Martin Debbie H. , Macaulay Ann C. , Pluye Pierre
Published: May 2017

A long‐standing challenge in community‐based participatory research (CBPR) has been to anchor practice and evaluation in a relevant and comprehensive theoretical framework of community change. This study describes the development of a multidimensional conceptual framework that builds on social movement theories to identify key components ofCBPRprocesses. Framework synthesis was used as a general literature search and analysis strategy. An initial conceptual framework was developed from the theoretical literature on social movement. A literature search performed to identify illustrativeCBPRprojects yielded 635 potentially relevant documents, from which eight projects (corresponding to 58 publications) were retained after record and full‐text screening. Framework synthesis was used to code and organize data from these projects, ultimately providing a refined framework. The final conceptual framework maps key concepts ofCBPRmobilization processes, such as the pivotal role of the partnership; resources and opportunities as necessary components feeding the partnership's development; the importance of framing processes; and a tight alignment between the cause (partnership's goal), the collective action strategy, and the system changes targeted. The revised framework provides a context‐specific model to generate a new, innovative understanding ofCBPRmobilization processes, drawing on existing theoretical foundations.
Methylated Phenylarsenical Metabolites Discovered in Chicken Liver
Authors: Peng Hanyong , Hu Bin , Liu Qingqing , Li Jinhua , Li Xing‐Fang , Zhang Hongquan , Le X. Chris
Published: May 2017

We report the discovery of three toxicologically relevant methylated phenylarsenical metabolites in the liver of chickens fed 3‐nitro‐4‐hydroxyphenylarsonic acid (ROX), a feed additive in poultry production that is still in use in several countries. Methyl‐3‐nitro‐4‐hydroxyphenylarsonic acid (methyl‐ROX), methyl‐3‐amino‐4‐hydroxyphenylarsonic acid (methyl‐3‐AHPAA), and methyl‐3‐acetamido‐4‐hydroxyphenylarsonic acid (or methyl‐N‐acetyl‐ROX, methyl‐N‐AHPAA) were identified in such chicken livers, and the concentration of methyl‐ROX was as high as 90 μg kg−1, even after a five‐day clearance period. The formation of these newly discovered methylated metabolites from reactions involving trivalent phenylarsonous acid substrates, S‐adenosylmethionine, and the arsenic (+3 oxidation state) methyltransferase enzyme As3MT suggests that these compounds are formed by addition of a methyl group to a trivalent phenylarsenical substrate in an enzymatic process. The IC50 values of the trivalent phenylarsenical compounds were 300–30 000 times lower than those of the pentavalent phenylarsenicals.
Metal‐Coordination‐Assisted Folding and Guest Binding in Helical Aromatic Oligoamide Molecular Capsules
Authors: Horeau Maxime , Lautrette Guillaume , Wicher Barbara , Blot Virginie , Lebreton Jacques , Pipelier Muriel , Dubreuil Didier , Ferrand Yann , Huc Ivan
Published: May 2017

The development of foldamer‐based receptors is driven by the design of monomers with specific properties. Herein, we introduce a pyridazine‐pyridine‐pyridazine diacid monomer and its incorporation into helical aromatic oligoamide foldamer containers. This monomer codes for a wide helix diameter and can sequester metal ions on the inner wall of the helix cavity. Crystallographic studies and NMR titrations show that part of the metal coordination sphere remains available and may then promote the binding of a guest within the cavity. In addition to metal coordination, binding of the guest is assisted by cooperative interactions with the helix host, thereby resulting in significant enhancements depending on the foldamer sequence, and in slow guest capture and release on the NMR time scale. In the absence of metal ions, the pyridazine‐pyridine‐pyridazine monomer promotes an extended conformation of the foldamer that results in aggregation, including the formation of an intertwined duplex.
Atroposelective Synthesis of Axially Chiral Biaryls by Palladium‐Catalyzed Asymmetric C−H Olefination Enabled by a Transient Chiral Auxiliary
Authors: Yao Qi‐Jun , Zhang Shuo , Zhan Bei‐Bei , Shi Bing‐Feng
Published: May 2017

Atroposelective synthesis of axially chiral biaryls by palladium‐catalyzed C−H olefination, using tert‐leucine as an inexpensive, catalytic, and transient chiral auxiliary, has been realized. This strategy provides a highly efficient and straightforward access to a broad range of enantioenriched biaryls in good yields (up to 98 %) with excellent enantioselectivities (95 to >99 % ee). Kinetic resolution of trisubstituted biaryls bearing sterically more demanding substituents is also operative, thus furnishing the optically active olefinated products with excellent selectivity (95 to >99 % ee, s‐factor up to 600).
The Elusive Structural Origin of Plastic Bending in Dimethyl Sulfone Crystals with Quasi‐isotropic Crystal Packing
Authors: Thomas Sajesh P. , Shi Ming W. , Koutsantonis George A. , Jayatilaka Dylan , Edwards Alison J. , Spackman Mark A.
Published: May 2017

Bending in molecular crystals is typically associated with the anisotropy of intermolecular interactions. The intriguing observation is reported of plastic bending in dimethyl sulfone, which exhibits nearly isotropic crystal packing and interaction topology, defying the known structural models of bending crystals. The origin of the bending phenomenon has been explored in terms of intermolecular interaction energies, experimental X‐ray charge density analysis, and variable temperature neutron diffraction studies. H⋅⋅⋅H dihydrogen interactions and differences in electrostatic complementarity between molecular layers are found to facilitate the bending behavior.
Mild, Redox‐Neutral Formylation of Aryl Chlorides through the Photocatalytic Generation of Chlorine Radicals
Authors: Nielsen Matthew K. , Shields Benjamin J. , Liu Junyi , Williams Michael J. , Zacuto Michael J. , Doyle Abigail G.
Published: May 2017

We report a redox‐neutral formylation of aryl chlorides that proceeds through selective 2‐functionalization of 1,3‐dioxolane through nickel and photoredox catalysis. This scalable benchtop approach provides a distinct advantage over traditional reductive carbonylation in that no carbon monoxide, pressurized gas, or stoichiometric reductant is employed. The mild conditions give unprecedented scope from abundant and complex aryl chloride starting materials.
Ethanol as a Hydrogenating Agent: Palladium‐Catalyzed Stereoselective Hydrogenation of Ynamides To Give Enamides
Authors: Siva Reddy Alla , Kumara Swamy K. C.
Published: May 2017

Ethanol is shown to act as a hydrogenating agent for ynamides under palladium catalysis. This behavior is different from the normally expected reaction of ethanol addition to alkynes. The reaction shows stereoselectivity for E enamides, which is in contrast to reports using other hydrogenating sources. The method was also extended to ynamines. Alternatively, the use of ethanol and ammonium formate as the hydrogenating source gives Z enamides. The role of ethanol in hydrogenation was demonstrated by means deuterium labeling experiment.
Self‐Assembly of Conjugated Metallopolymers with Tunable Length and Controlled Regiochemistry
Authors: Greenfield Jake L. , Rizzuto Felix J. , Goldberga Ieva , Nitschke Jonathan R.
Published: May 2017

Self‐assembled materials can be designed to express useful optoelectronic properties; however, achieving structural control is a necessary precondition for the optimization of desired properties. Here we report a simple, metal‐templated polymerization process that generates helical metallopolymer strands over 75 repeat units long (28 kDa) from a single bifunctional monomer and CuI. The resulting polymer consists of a double helix of two identical conjugated organic strands enclosing a central column of metal ions. The length of this metallopolymer can be controlled by adding monofunctional subcomponents to end‐cap the conjugated ligands. The use of ditopic and bulky monotopic subcomponents, respectively, allows a head‐to‐head or head‐to‐tail double helix to be generated. Spectroscopic measurements of different polymer lengths demonstrate how control over polymer length leads to control over the electronic and luminescent properties of the resulting material, thereby enabling tunable white‐light emission.
The Femtochemistry of a Ferracyclobutadiene
Authors: Wezisla Boris , Lindner Jörg , Das Ujjal , Filippou Alexander C. , Vöhringer Peter
Published: May 2017

The eminent role of metallacyclobutadienes as catalytic intermediates in organic synthesis and polymer chemistry is widely acknowledged. In contrast, their photochemistry is as yet entirely unexplored. Herein, the photo‐induced primary processes of a ferracyclobutadiene tricarbonyl complex in solution are revealed by femtosecond mid‐infrared spectroscopy. The time‐resolved vibrational spectra expose an ultrafast substitution of a basal CO ligand by a solvent molecule in a consecutive dissociation–association mechanism. Following optical excitation, the system relaxes non‐radiatively to the triplet ground state from which a CO is expelled. Since the triplet state is bound with respect to Fe−CO cleavage, the dissociation can only occur from vibrationally excited states. The excitation energy, vibrational relaxation, and intersystem crossing to the singlet ground state control the primary quantum yield for formation of the ferracyclic dicarbonyl–solvent product complex.
Triggering Redox Activity in a Thiophene Compound: Radical Stabilization and Coordination Chemistry
Authors: Curcio Massimiliano , Pankhurst James R. , Sproules Stephen , Mignard Dimitri , Love Jason B.
Published: May 2017

The synthesis, metalation, and redox properties of an acyclic bis(iminothienyl)methene L− are presented. This π‐conjugated anion displayed pronounced redox activity, undergoing facile one‐electron oxidation to the acyclic, metal‐free, neutral radical L. on reaction with FeBr2. In contrast, the reaction of L− with CuI formed the unique, neutral Cu2I2(L.) complex of a ligand‐centered radical, whereas reaction with the stronger oxidant AgBF4 formed the metal‐free radical dication L.2+.
Elusive Terminal Copper Arylnitrene Intermediates
Authors: Bakhoda Abolghasem (Gus) , Jiang Quan , Bertke Jeffery A. , Cundari Thomas R. , Warren Timothy H.
Published: May 2017

We report herein three new modes of reactivity between arylazides N3Ar with a bulky copper(I) β‐diketiminate. Addition of N3ArX3 (ArX3=2,4,6‐X3C6H2; X=Cl or Me) to [iPr2NN]Cu(NCMe) results in triazenido complexes from azide attack on the β‐diketiminato backbone. Reaction of [iPr2NN]Cu(NCMe) with bulkier azides N3Ar leads to terminal nitrenes [iPr2NN]Cu]=NAr that dimerize via formation of a C−C bond at the arylnitrene p‐position to give the dicopper(II) diketimide 4 (Ar=2,6‐iPr2C6H3) or undergo nitrile insertion to give diazametallocyclobutene 8 (Ar=4‐Ph‐2,6‐iPr2C6H2). Importantly, reactivity studies reveal both 4 and 8 to be “masked” forms of the terminal nitrenes [iPr2NN]Cu=NAr that undergo nitrene group transfer to PMe3, tBuNC, and even into a benzylic sp3 C−H bond of ethylbenzene.
Concise Total Synthesis of Dioncophylline E through an ortho‐Arylation Strategy
Authors: Toop Hamish D. , Brusnahan Jason S. , Morris Jonathan C.
Published: May 2017

The first total synthesis of the potent antimalarial 7,3′‐linked naphthylisoquinoline alkaloid dioncophylline E (1) has been completed. The synthesis proceeds in 12 steps (longest linear sequence) and in 15 % overall yield. Key transformations include an ortho‐arylation of a naphthol with an aryllead triacetate to construct the sterically hindered biaryl bond, and a three‐step sequence to stereoselectively generate the trans‐1,3‐dimethyl‐1,2,3,4‐tetrahydroisoquinoline moiety.
Near‐Infrared Photothermally Activated DNAzyme–Gold Nanoshells for Imaging Metal Ions in Living Cells
Authors: Wang Wenjing , Satyavolu Nitya Sai Reddy , Wu Zhenkun , Zhang Jian‐Rong , Zhu Jun‐Jie , Lu Yi
Published: May 2017

DNAzymes have enjoyed success as metal ion sensors outside cells. Their susceptibility to metal‐dependent cleavage during delivery into cells has limited their intracellular applications. To overcome this limitation, a near‐infrared (NIR) photothermal activation method is presented for controlling DNAzyme activity in living cells. The system consists of a three‐stranded DNAzyme precursor (TSDP), the hybridization of which prevents the DNAzyme from being active. After conjugating the TSDP onto gold nanoshells and upon NIR illumination, the increased temperature dehybridizes the TSDP to release the active DNAzyme, which then carries out metal‐ion‐dependent cleavage, resulting in releasing the cleaved product containing a fluorophore. Using this construct, detecting Zn2+ in living HeLa cells is demonstrated. This method has expanded the DNAzyme versatility for detecting metal ions in biological systems under NIR light that exhibits lower phototoxicity and higher tissue penetration ability.
Total Synthesis of Rishirilide B by Organocatalytic Oxidative Kinetic Resolution: Revision of Absolute Configuration of (+)‐Rishirilide B
Authors: Odagi Minami , Furukori Kota , Takayama Kan , Noguchi Keiichi , Nagasawa Kazuo
Published: May 2017

Described herein is the enantioselective syntheses of (+)‐ and (−)‐rishirilide B from the corresponding optically active β‐substituted tetralones, which were obtained by oxidative kinetic resolution based on α‐hydroxylation in the presence of a chiral guanidine‐bisurea bifunctional organocatalyst. Benzylic oxidation of the tetralones at C1 followed by regioselective isomerization of the oxabenzonorbornadiene structure led to rishirilide B. Our findings lead to the revision of the previously proposed (2R,3R,4R) absolute configuration of (+)‐rishirilide B to (2S,3S,4S).
Electrochemical Motion Tracking of Microorganisms Using a Large‐Scale‐Integration‐Based Amperometric Device
Authors: Ino Kosuke , Kanno Yusuke , Inoue Kumi Y. , Suda Atsushi , Kunikata Ryota , Matsudaira Masahki , Shiku Hitoshi , Matsue Tomokazu
Published: May 2017

Motion tracking of microorganisms is useful to investigate the effects of chemical or physical stimulation on their biological functions. Herein, we describe a novel electrochemical imaging method for motion tracking of microorganisms using a large‐scale integration (LSI)‐based amperometric device. The device consists of 400 electrochemical sensors with a pitch of 250 μm. A convection flow caused by the motion of microorganisms supplies redox species to the sensors and increases their electrochemical responses. Thus, the flow is converted to electrochemical signals, enabling the electrochemical motion tracking of the microorganisms. As a proof of concept, capillary vibration was monitored. Finally, the method was applied to monitoring the motion of Daphnia magna. The motions of these microorganisms were clearly tracked based on the electrochemical oxidation of [Fe(CN)6]4− and reduction of O2.
Different Reactivity of As4towards Disilenes and Silylenes
Authors: Seitz Andreas E. , Eckhardt Maria , Sen Sakya S. , Erlebach Andreas , Peresypkina Eugenia V. , Roesky Herbert W. , Sierka Marek , Scheer Manfred
Published: May 2017

The activation of yellow arsenic is possible with the silylene [PhC(NtBu)2SiN(SiMe3)2] (1) and the disilene [(Me3Si)2N(η1‐Me5C5)Si=Si(η1‐Me5C5)N(SiMe3)2] (3). The reaction of As4with1leads to the unprecedented As10cage compound [(LSiN(SiMe3)2)3As10] (2; L=PhC(NtBu)2) with an As7nortricyclane core stabilized by arsasilene moieties containing silicon(II)bis(trimethylsilyl)amide substituents. In contrast, the compound [Cp*{(SiMe3)2N}SiAs]2(4) containing a butterfly‐like diarsadisilabicyclo[1.1.0]butane unit is formed by the reaction of As4with the disilene3. Both compounds were characterized by single‐crystal X‐ray diffraction analysis, NMR spectroscopy, and mass spectrometry. The reaction outcomes demonstrate the different reaction behavior of yellow arsenic (As4) compared to white phosphorus (P4) in the reactions with the corresponding silylenes and disilenes.
Small‐Molecule Inhibition of the UNC119–Cargo Interaction
Authors: Mejuch Tom , Garivet Guillaume , Hofer Walter , Kaiser Nadine , Fansa Eyad K. , Ehrt Christiane , Koch Oliver , Baumann Matthias , Ziegler Slava , Wittinghofer Alfred , Waldmann Herbert
Published: May 2017

N‐Terminal myristoylation facilitates membrane binding and activity of proteins, in particular of Src family kinases, but the underlying mechanisms are only beginning to be understood. The chaperones UNC119A/B regulate the cellular distribution and signaling of N‐myristoylated proteins. Selective small‐molecule modulators of the UNC119–cargo interaction would be invaluable tools, but have not been reported yet. We herein report the development of the first UNC119–cargo interaction inhibitor, squarunkin A. Squarunkin A selectively inhibits the binding of a myristoylated peptide representing the N‐terminus of Src kinase to UNC119A with an IC50 value of 10 nm. It binds to UNC119 proteins in cell lysate and interferes with the activation of Src kinase. Our results demonstrate that small‐molecule inhibition of the UNC119–cargo interaction might provide new opportunities for modulating the activity of Src kinases that are independent of direct inhibition of the enzymatic kinase activity.
Insights Into How Heme Reduction Potentials Modulate Enzymatic Activities of a Myoglobin‐based Functional Oxidase
Authors: Bhagi‐Damodaran Ambika , Kahle Maximilian , Shi Yelu , Zhang Yong , Ädelroth Pia , Lu Yi
Published: May 2017

Heme‐copper oxidase (HCO) is a class of respiratory enzymes that use a heme‐copper center to catalyze O2 reduction to H2O. While heme reduction potential (E°′) of different HCO types has been found to vary >500 mV, its impact on HCO activity remains poorly understood. Here, we use a set of myoglobin‐based functional HCO models to investigate the mechanism by which heme E°′ modulates oxidase activity. Rapid stopped‐flow kinetic measurements show that increasing heme E°′ by ca. 210 mV results in increases in electron transfer (ET) rates by 30‐fold, rate of O2 binding by 12‐fold, O2 dissociation by 35‐fold, while decreasing O2 affinity by 3‐fold. Theoretical calculations reveal that E°′ modulation has significant implications on electronic charge of both heme iron and O2, resulting in increased O2 dissociation and reduced O2 affinity at high E°′ values. Overall, this work suggests that fine‐tuning E°′ in HCOs and other heme enzymes can modulate their substrate affinity, ET rate and enzymatic activity.
Synthesis of Layered Carbonitrides from Biotic Molecules for Photoredox Transformations
Authors: Yang Can , Wang Bo , Zhang Linzhu , Yin Ling , Wang Xinchen
Published: May 2017

The construction of layered covalent carbon nitride polymers based on tri‐s‐triazine units has been achieved by using nucleobases (adenine, guanine, cytosine, thymine and uracil) and urea to establish a two‐dimensional semiconducting structure that allows band‐gap engineering applications. This biomolecule‐derived binary carbon nitride polymer enables the generation of energized charge carrier with light‐irradiation to induce photoredox reactions for stable hydrogen production and heterogeneous organosynthesis of C−O, C−C, C−N and N−N bonds, which may enrich discussion on chemical reactions in prebiotic conditions by taking account of the photoredox function of conjugated carbonitride semiconductors that have long been considered to be stable HCN‐derived organic macromolecules in space.
The Spider Orchid Caladenia crebra Produces Sulfurous Pheromone Mimics to Attract its Male Wasp Pollinator
Authors: Bohman Björn , Phillips Ryan D. , Flematti Gavin R. , Barrow Russell A. , Peakall Rod
Published: May 2017

One of the most intriguing natural observations is the pollination of orchids by sexual deception. Chemicals underpin this interaction between the orchid and its sexually attracted male insect pollinator, with the signaling compounds involved, called semiochemicals, predicted to mimic the chemical composition of the sex pheromone. We identified floral semiochemicals from Caladenia (spider orchids) for the first time. We further demonstrate that C. crebra attracts its single pollinator species with a unique system of (methylthio)phenols, three of which are new natural products. Furthermore, as predicted, the same compounds constitute the sex pheromone of the pollinator, the thynnine wasp Campylothynnus flavopictus, representing the first occurrence of sulfurous sex pheromones in Hymenoptera.
Phase diagram for the Na2O–PbO–H2O system at 130 °C
Authors: Liu Yan , Duan Dongping
Published: May 2017

A phase diagram of the Na2O–PbO–H2O system at 130 °C was studied using Schreinemakers's method, to provide fundamental data for producing PbO via hydrometallurgical process. In the phase diagram, saturated solubility of PbO has two maximum values vs the sodium hydroxide concentration in the solution. The equilibrium solid phases of lead oxide (PbO), sodium plumbite hydroxide (Na2O·PbO·H2O) and sodium hydroxide (NaOH) were identified in the different alkali concentration regions, which is different from that at low temperature presented in literature. Copyright © 2017 Curtin University of Technology and John Wiley & Sons, Ltd.
Simultaneous removal of Cd, Co, Cu, Mn, Ni, and Zn from synthetic solutions on a hemp‐based felt. II. Chemical modification
Authors: Loiacono Sonia , Crini Grégorio , Martel Bernard , Chanet Gilles , Cosentino Cesare , Raschetti Marina , Placet Vincent , Torri Giangiacomo , Morin‐Crini Nadia
Published: May 2017

In this study, we propose a chemical pretreatment to improve the performance of a hemp‐based material in felt form used as an adsorbent for removing the metals from aqueous mixtures of Cd, Co, Cu, Mn, Ni, and Zn. The felt was coated with a maltodextrin‐1,2,3,4‐butane tetracarboxylic polymer in order to provide ion‐exchange properties to the material by introducing carboxylic groups. It was characterized by solid‐state 13C‐NMR technique and by energy‐dispersive X‐ray spectroscopy. This new adsorbent was then used in batch experiments and its performances were compared with those of non‐modified hemp. Different controlling experimental conditions have been investigated. Modified hemp exhibited strong adsorption capacities due to a chemisorption mechanism (complexation, ion exchange): up to 25 mg/L (in reality, 150 mg of metals per L), all metals in the solution were removed. A modified hemp dosage of 1 g was able to remove 13.91 mg of metals in 100 mL of solution at a concentration of 25 mg/L for each metal, whereas nonmodified hemp only removed 7.4 mg in the same experimental conditions. Adsorption of metals reached equilibrium in 60 min and the performances were pH‐independent between 3 and 6, but dependent on the presence of NaCl, except for Cu. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45138.
Preparation of a novel poly(ether sulfone) adsorptive ultrafiltration membrane containing a crosslinked quaternary chitosan salt and chromate removal
Authors: Huang Zheng‐Qing , Yang Tian‐Qi , Zhou Kai‐Mei , Chen Jun‐Ping , Wei Peng , Zhang Zhi , Xu Hong‐Tao
Published: May 2017

To improve the removal performance of low‐concentration hexavalent chromium [Cr(VI)] in the ultrafiltration (UF) process, adsorptive UF membranes were prepared from suspensions consisting of poly(ether sulfone), N,N‐dimethylacetamide, poly(vinyl pyrrolidone), and crosslinked quaternary chitosan salt (CQS). The results show that the contact angle of the membrane increased from 67 to 83° when the content of CQS was changed from 0 to 10 wt %. Meanwhile, the initial rejection of bovine serum albumin decreased from 90 to 61%, and the pure water fluxes of the membranes showed no obvious change. The rejection of Cr(VI) increased from 20% to 87% when the content of CQS was changed from 0 to 10 wt % in the membrane. Adsorptive UF membranes could be generated by a 1 mol/L solution of NaCl. The adsorption data were more applicable for a pseudo‐second‐order kinetic model and the Langmuir isotherm model. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45198.
Haploinsufficiency of NADPH Oxidase Subunit Neutrophil Cytosolic Factor 2 Is Sufficient to Accelerate Full‐Blown Lupus in NZM 2328 Mice
Authors: Jacob Chaim O. , Yu Ning , Yoo Dae‐Goon , Perez‐Zapata Lizet J. , Barbu Emilia Alina , Kaplan Mariana J. , Purmalek Monica , Pingel Jeanette T. , Idol Rachel A. , Dinauer Mary C.
Published: May 2017

Objective

We have previously established that the gene for neutrophil cytosolic factor 2 (NCF‐2) predisposes to lupus, and we have identified lupus patients with point mutations that are predicted to cause reduced NADPH oxidase activity. We undertook this study to investigate the relationship between reduced leukocyte NADPH oxidase activity and immune dysregulation associated with systemic lupus erythematosus (SLE).

Methods

We generated NCF‐2–null mice, in which NADPH oxidase activity is absent, on the nonautoimmune C57BL/6 (B6) mouse background and on the NZM 2328 mouse background, a polygenic model in which mice spontaneously develop lupus. Clinical disease, serology, and immunopathology were evaluated.

Results

NCF‐2–null mice on the B6 background were susceptible to Aspergillus fumigatus pneumonia characteristic of chronic granulomatous disease, but did not develop systemic lupus disease. In contrast, NCF‐2–null and even NCF‐2–haploinsufficient mice on the NZM 2328 background developed accelerated full‐blown lupus with significantly accelerated lupus kidney disease. This was characterized by more rapid development of hyperactive B cell and T cell immune compartments, increased expression of type I interferon–responsive genes, and generation of neutrophil extracellular traps, which were observed even in the absence of NADPH oxidase activity.

Conclusion

Just as patients with chronic granulomatous disease who lack NADPH oxidase rarely develop SLE, NCF‐2–null mice on a nonautoimmune background were susceptible to a chronic granulomatous disease–like opportunistic infection but did not develop lupus. In contrast, on a lupus‐prone background, even haploinsufficiency of NCF‐2 accelerated the development of full‐blown lupus disease. This establishes an interaction between reduced oxidase activity and other lupus‐predisposing genes, paralleling human SLE–associated variants predicted to have only reduced NADPH oxidase activity.
Storied emotional distances in the relationships between beginning teachers and school principals
Authors: Lassila Erkki T. , Timonen Virpi , Uitto Minna , Estola Eila
Published: May 2017

Recent research has acknowledged the importance of the relationships of school principals with beginning teachers. However, little is known about how emotions inform these relationships from the beginning teacher's side. Applying the concept of emotional geographies, this paper explores the kinds of storied emotional distances that appear in the relationships between beginning teachers and their principals. Based on interviews with beginning Japanese teachers, the results indicate that such relationships may be: (1) very direct and personal; (2) acted out indirectly by the principal as personal facilitator ‘behind the scenes’ or as public gatekeeper; or (3) mediated by the teacher community. The analysis reveals beginning teachers’ personal experiences of these relationships, as well as how such relationships are influenced by organisational and cultural context. Although principals are described as distant figures within the school organisation, they are seen to play an important role in facilitating beginning teachers’ work by connecting with them at a personal level and providing good working conditions by influencing the emotional atmosphere of the teacher community or by sheltering them from parental pressure.
Multiple, relational and emotional mobilities: Understanding student mobilities in higher education as more than ‘staying local’ and ‘going away’
Authors: Finn Kirsty
Published: May 2017

This paper advances theorising around student geographies in higher education (HE). It extends recent work, which has problematised the primacy of social class and binary thinking about student mobilities, and presents local/non‐local experiences and im/mobility as a defining dualism. Drawing on a qualitative longitudinal study of women's experiences during and on completion of HE, the following explores the ways in which a more diverse and constantly negotiated set of mobility practices emerge relationally, in the stratified field of HE, and through shifting personal and emotional attachments. Theoretically, the paper develops a new approach to student mobilities, synthesising dominant Bourdieusian notions of field with relational theories pertaining to mobilities (e.g. Adey, 2009), emotion (e.g. Holmes, 2010) and personal life (e.g. Mason, 2004; Smart, 2007). Such an approach makes it possible to move beyond the binary thinking that has become entrenched in policy and academic debates about student mobilities, and recognise a broader range of movements, flows, stops and starts that emerge relationally, emotionally and temporally as students and graduates move into and through HE. It is argued here that, given the policy emphasis on accelerated and flexible HE provision (BIS, 2016), a gradational view of student mobilities is more important than ever.
Robot kinematics made easy using RoboAnalyzer software
Authors: Othayoth Ratan S. , Chittawadigi Rajeevlochana G. , Joshi Ravi P. , Saha Subir K.
Published: May 2017

RoboAnalyzer is a software based on 3D model of robots. It was developed primarily for teaching and learning of robot mechanics, although it is robust enough for the use by researchers as well. The motive behind the development of RoboAnalyzer was mainly to help teachers and students get started with teaching/learning of robotics using template‐based skeleton models or CAD models of serial robots. This minimizes the time otherwise spent on modeling, programming, and simulating the robots from scratch. In this article, we focus on the visualization of the Denavit Hartenberg (DH) parameters used to define a robot's architecture, and the modeling of the robot's input‐output motion characteristics, that is, robot kinematics, using them. The advantages of using RoboAnalyzer to overcome several challenges of learning robotics in a classroom environment are also discussed.
“To serve and protect” when expecting to be seen negatively: The relation between police officers' contact with citizens, meta‐stereotyping, and work‐related well‐being
Authors: Gordijn Ernestine H. , Vacher Loreline , Kuppens Toon
Published: May 2017

We examined the relationship between contact of police officers with citizens, their (meta‐)stereotypes about citizens, and their work‐related well‐being. Ninety‐three police officers from 4 police stations in low‐ and high‐crime regions in France completed the questionnaire. As expected, negative well‐being of police officers is predicted by negative contact with citizens and their belief that police officers are stereotyped negatively by citizens. Moreover, the relationship between negative contact and negative well‐being was mediated by police officers' beliefs that police officers are perceived negatively by citizens, whereas their perceptions of citizens did not mediate this relationship. Interestingly, level of crime did not influence these relationships. Together, this research shows the important role of beliefs about how one's group is stereotyped when in contact with another group as it may have consequences for people's well‐being.
Selective Covalent Protein Modification by 4‐Halopyridines through Catalysis
Authors: Schardon Christopher L. , Tuley Alfred , Er Joyce A. V. , Swartzel Jake C. , Fast Walter
Published: May 2017

We have investigated 4‐halopyridines as selective, tunable, and switchable covalent protein modifiers for use in the development of chemical probes. Nonenzymatic reactivity of 4‐chloropyridine with amino acids and thiols was ranked with respect to common covalent protein‐modifying reagents and found to have reactivity similar to that of acrylamide, but could be switched to a reactivity similar to that of iodoacetamide upon stabilization of the positively charged pyridinium. Diverse, fragment‐sized 4‐halopyridines inactivated human dimethylarginine dimethylaminohydrolase‐1 (DDAH1) through covalent modification of the active site cysteine, acting as quiescent affinity labels that required off‐pathway catalysis through stabilization of the protonated pyridinium by a neighboring aspartate residue. A series of 2‐fluoromethyl‐substituted 4‐chloropyridines demonstrated that the pKa and kinact/KI values could be predictably varied over several orders of magnitude. Covalent labeling of proteins in an Escherichia coli lysate was shown to require folded proteins, indicating that alternative proteins can be targeted, and modification is likely to be catalysisdependent. 4‐Halopyridines, and quiescent affinity labels in general, represent an attractive strategy to develop reagents with switchable electrophilicity as selective covalent protein modifiers.
FLUORO/NO: A Nitric Oxide Donor with a Fluorescence Reporter
Authors: Ravikumar Govindan , Bagheri Meisam , Saini Deepak Kumar , Chakrapani Harinath
Published: May 2017

Nitric oxide (NO) plays significant signalling roles in cells; the controlled generation of NO is of therapeutic relevance. Although a number of methods for the delivery and detection of NO are available, these events are typically mutually exclusive. Furthermore, the efficiency of delivery of NO can be compromised by detection technologies that consume NO. Here, we report FLUORO/NO, an esterase‐activated diazeniumdiolate‐based NO donor with an in‐built fluorescence reporter. We demonstrate that this compound is capable of enhancing NO within cells in a dose‐dependent manner, accompanied by a similar increase in fluorescence. The compatibility of this tool to study NO‐mediated signalling as well as NO‐mediated stress is demonstrated. FLUORO/NO is a convenient tool that shows NO‐like activity and allows monitoring of NO release. This tool will help interrogate the redox biology of NO.
Patient preference for radial versus femoral vascular access for elective coronary procedures: The PREVAS study
Authors: Kok Marlies M. , Weernink Marieke G.M. , von Birgelen Clemens , Fens Anneloes , van der Heijden Liefke C. , van Til Janine A.
Published: May 2017

Objectives

To explore patient preference for vascular access site in percutaneous coronary procedures, the perceived importance of benefits and risks of transradial access (TRA) and transfemoral access (TFA) were assessed. In addition, direct preference for vascular access and preference for shared decision making (SDM) were evaluated.

Background

TRA has gained significant ground on TFA during the last decades. Surveys on patient preference have mostly been performed in dedicated TRA trials.

Methods

In the PREVAS study (Clinicaltrials.gov: NCT02625493) a stated preference elicitation method best‐worst scaling (BWS) was used to determine patient preference for six treatment attributes: bleeding, switch of access‐site, postprocedural vessel quality, mobilization and comfort, and over‐night stay. Based on software‐generated treatment scenarios, 142 patients indicated which characteristics they perceived most and least important in treatment choice. Best‐minus‐Worst scores and attribute importance were calculated.

Results

Bleeding risk was considered most important (attribute importance 31.3%), followed by length of hospitalization (22.6%), and mobilization(20.2%). Most patients preferred the approach of their current procedure (85.9%); however, 71.1% of patients with experience with both access routes favored TRA (P < 0.001). Most patients (38.0%) appreciated SDM, balanced between patient and cardiologist.

Conclusions

Patients appreciate lower bleeding risk and early ambulation, factors favoring TRA. Previous experience with a single access route has a major impact on preference, while experience with both routes generally resulted in preference for TRA. Most patients prefer balanced SDM. © 2017 The Authors Catheterization and Cardiovascular Interventions Published by Wiley Periodicals, Inc.
Long or redundant leaflet complicating transcatheter mitral valve replacement: Case vignettes that advocate for removal or reduction of the anterior mitral leaflet
Authors: Greenbaum Adam B. , Condado Jose F. , Eng Marvin , Lerakis Stamatios , Wang Dee Dee , Kim Dennis W. , Lederman Robert J. , Paone Gaetano , Neill William W. O. , Thourani Vinod H. , Babaliaros Vasilis C.
Published: May 2017

Transcatheter mitral valve replacement (TMVR) procedures can be an alternative to surgical valve replacement for high surgical risk patients with bioprosthetic mitral valves, annuloplasty rings, or severe mitral annular calcification (MAC). TMVR can trigger acute left ventricular outflow tract (LVOT) obstruction from permanent displacement of the native anterior mitral leaflet toward the left ventricular septum, more often among patients undergoing valve‐in‐ring and valve‐in‐MAC procedures. Although acute LVOT obstruction is well described in the literature, there are important additional complications of TMVR related to the length and/or redundancy of the anterior mitral valve that have been recognized after mitral valve surgery and have not been previously reported in the setting of TMVR. These additional complications include acute mitral regurgitation secondary to prolapsing native leaflet through the TMVR, frozen TMVR leaflet secondary to overhanging native leaflet and late LVOT obstruction in the neo‐LVOT secondary to long native leaflet. Preprocedural planning with imaging (echocardiography and computed tomography) and measurement of anterior mitral leaflet length is critical important in understanding the risk for these complications. As transcatheter mitral valve technology proliferates, interactions with the anterior mitral leaflet after TMVR may be more frequent than initially anticipated. We believe that there is no advantage to an intact anterior leaflet and advocate removal or reduction of the leaflet prior to TMVR. © 2017 Wiley Periodicals, Inc.
SUPERB final 3‐year outcomes using interwoven nitinol biomimetic supera stent
Authors: Garcia Lawrence A. , Rosenfield Kenneth R. , Metzger Christopher D. , Zidar Frank , Pershad Ashish , Popma Jeffrey J. , Zaugg Margo , Jaff Michael R. ,   on behalf of the SUPERB investigators
Published: May 2017

Importance

Long‐term outcomes of an interwoven nitinol stent design represent the best in class for treatment of lower limb arterial obstructive disease

Methods

The subjects were enrolled in an open single arm study comparing the outcomes to an FDA mandated objective performance goal (OPG).

Results

About 325 patients (264 intention‐to‐treat and 64 roll‐in subjects) were enrolled. Mean follow‐up period was 887+/– 352 days. Treated lesion lengths were 7.8 cm ± 4.3 cm in the trial with chronic total occlusions comprising 24.6% (65/264) of subjects. Freedom from clinically driven target lesion revascularization (CD‐TLR) at 12 months was 89%, at 24 and 36 months it was 84% and 82% respectively. The difference in the 12 month CD‐TLR was 7% at 36 months. The difference of clinically driven‐TLR at 36 months in those subjects who received their stents deployed nominally in length, compressed or elongated (between −10% and +10% nominal length) had an impact on the CD‐TLR. At 2 and 3 years, freedom from CD‐TLR in minimal compression was 86.7%, and was 90.0% for moderate compression. In those stents deployed with minimal, moderate, or severe elongation (10–20%, 20–40%, or >40%, respectively) freedom from CD‐TLR of 84.1%, 87.4%, and 77.0% respectively at 12 months. At 2 and 3 years, freedom from CD‐TLR for moderate elongation was 81.8% and 78.2%, and for severe elongation was 63.4% and 42.3%, respectively. Fractures were distinctly uncommon with this stent with a single facture event in the 36 month follow‐up period.

Discussion

The interwoven nitinol design stent is a stent that achieves an excellent primary patency but further maintains the durability of the stent through 36 months. Optimal stent deployment remains critical to the performance of this stent device and requires optimal vessel preparation. © 2017 Wiley Periodicals, Inc.
Percutaneous transcatheter balloon dilatation and stenting to the inflow cannula stenosis of a left ventricular assist device
Authors: Carr Stephen M. , Lubbe Dieter F. , Huber Philip R.
Published: May 2017

Left ventricular assist devices (LVAD) improve survival in patients with advanced heart failure but are prone to various complications causing mechanical failure. Inflow cannula stenosis presents a particular challenge often requiring invasive surgical repair. We present a novel transcatheter approach for stent delivery to successfully restore hemodynamic function in a patient with inflow cannula stenosis of a HeartMate II LVAD. © 2017 Wiley Periodicals, Inc.
The prognostic importance of the diastolic pulmonary gradient, transpulmonary gradient, and pulmonary vascular resistance in patients undergoing transcatheter aortic valve replacement
Authors: Brunner Nathan W. , Yue Su Fei , Stub Dion , Ye Jian , Cheung Anson , Leipsic Jonathon , Lauck Sandra , Dvir Danny , Perlman Gidon , Htun Nay , Fahmy Peter , Prakash Roshan , Eng Lim , Ong Kevin , Tsang Michael , Cairns John A. , Webb John G. , Wood David A.
Published: May 2017

Objectives

To evaluate the association between markers of precapillary pulmonary hypertension (PH) and survival in transcatheter aortic valve replacement (TAVR).

Background

The importance of precapillary PH has been sparsely investigated in patients undergoing TAVR. It may prove an important risk factor for poor outcomes.

Methods

We identified patients at our institution undergoing TAVR with a baseline right heart catheterization (RHC) demonstrating PH. We evaluated the association between markers of precapillary PH and survival including the diastolic pulmonary gradient (DPG), transpulmonary gradient (TPG), and pulmonary vascular resistance (PVR). A multivariable analysis was performed using Cox Proportional Hazards Models, adjusting for age, gender, body mass index, and pulmonary artery systolic pressure (PASP) on echocardiography.

Results

We identified 133 patients with PH on RHC. Of these 111 had low DPG and 22 had high DPG. All 3 markers of precapillary PH were associated with worse survival post TAVR, with OR of 2.1 (95% CI 1.1–3.9, P = 0.02), 3.4 (95% CI 1.8–6.4, P < 0.001) and 2.5 (95% CI 1.4–4.5, P = 0.003) for high DPG, TPG, and PVR, respectively. On multivariable analysis, both TPG and PVR remained predictors of worse survival, with OR of 3.4 (95% CI 1.7–6.9, P = 0.001) and 2.5 (95% CI 1.4–4.5, P = 0.003). Echocardiographic PASP and DPG were not predictive of survival.

Conclusions

In patients undergoing TAVR, parameters of precapillary PH are associated with lower survival, and provide incremental prognostication over echocardiographic PASP. RHC should continue to play an important role in risk stratification prior to TAVR. © 2017 Wiley Periodicals, Inc.