bluuebunny/crossref_metadata_2025 huggingface dataset:
Probing the Surface of a Laccase for Clues towards the Design of Chemo‐Enzymatic Catalysts
Authors: Robert Viviane , Monza Emanuele , Tarrago Lionel , Sancho Ferran , De Falco Anna , Schneider Ludovic , Npetgat Ngoutane Eloïne , Mekmouche Yasmina , Pailley Pierre Rousselot , Simaan A. Jalila , Guallar Victor , Tron Thierry
Published: February 2017

Systems featuring a multi‐copper oxidase associated with transition‐metal complexes can be used to perform oxidation reactions in mild conditions. Here, a strategy is presented for achieving a controlled orientation of a ruthenium–polypyridyl graft at the surface of a fungal laccase. Laccase variants are engineered with unique surface‐accessible lysine residues. Distinct ruthenium–polypyridyl‐modified laccases are obtained by the reductive alkylation of lysine residues precisely located relative to the T1 copper centre of the enzyme. In none of these hybrids does the presence of the graft compromise the catalytic efficiency of the enzyme on the substrate 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid). Furthermore, the efficiency of the hybrids in olefin oxidation coupled to the light‐driven reduction of O2 is highly dependent on the location of the graft at the enzyme surface. Simulated RuII–CuII electron coupling values and distances fit well the observed reactivity and could be used to guide future hybrid designs.
PdAuCu Nanobranch as Self‐Repairing Electrocatalyst for Oxygen Reduction Reaction
Authors: Gong Hongyu , Cao Xuecheng , Li Fan , Gong Yue , Gu Lin , Mendes Rafael Gregorio , Rummeli Mark H. , Strasser Peter , Yang Ruizhi
Published: February 2017

During start‐up and shut‐down operations of fuel cells, high potential is inevitably experienced at cathode, which leads to the deterioration of the oxygen reduction electrocatalyst. The design of catalysts that can repair themselves under severe conditions has been identified as a primary challenge for fuel cells. Herein, self‐supported PdAuCu branched nanostructure is synthesized by a hydrothermal method. By smartly utilizing the high‐potential treatment, the activity of PdAuCu is significantly enhanced owing to the synergistic effect between the Pd and CuII generated by such treatment. Moreover, the high activity of PdAuCu can be well maintained by repeating the high‐potential treatment. We hence propose this catalyst as a “self‐repairing” catalyst in a broad sense.
Selective Hydrodeoxygenation of 5‐Hydroxymethylfurfural to 2,5‐Dimethylfuran over Heterogeneous Iron Catalysts
Authors: Li Jiang , Liu Jun‐ling , Liu He‐yang , Xu Guang‐yue , Zhang Jun‐jie , Liu Jia‐xing , Zhou Guang‐lin , Li Qin , Xu Zhi‐hao , Fu Yao
Published: February 2017

This work provided the first example of selective hydrodeoxygenation of 5‐hydroxymethylfurfural (HMF) to 2,5‐dimethylfuran (DMF) over heterogeneous Fe catalysts. A catalyst prepared by the pyrolysis of an Fe‐phenanthroline complex on activated carbon at 800 °C was demonstrated to be the most active heterogeneous Fe catalyst. Under the optimal reaction conditions, complete conversion of HMF was achieved with 86.2 % selectivity to DMF. The reaction pathway was investigated thoroughly, and the hydrogenation of the C=O bond in HMF was demonstrated to be the rate‐determining step during the hydrodeoxygenation, which could be accelerated greatly by using alcohol solvents as additional H‐donors. The excellent stability of the Fe catalyst, which was probably a result of the well‐preserved active species and the pore structure of the Fe catalyst in the presence of H2, was demonstrated in batch and continuous flow fixed‐bed reactors.
The electrical synapse: Molecular complexities at the gap and beyond
Authors: Miller Adam C. , Pereda Alberto E.
Published: February 2017

Gap junctions underlie electrical synaptic transmission between neurons. Generally perceived as simple intercellular channels, “electrical synapses” have demonstrated to be more functionally sophisticated and structurally complex than initially anticipated. Electrical synapses represent an assembly of multiple molecules, consisting of channels, adhesion complexes, scaffolds, regulatory machinery, and trafficking proteins, all required for their proper function and plasticity. Additionally, while electrical synapses are often viewed as strictly symmetric structures, emerging evidence has shown that some components forming electrical synapses can be differentially distributed at each side of the junction. We propose that the molecular complexity and asymmetric distribution of proteins at the electrical synapse provides rich potential for functional diversity. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 562–574, 2017
Proton‐Coupled Electron Transfer in Photoredox Catalytic Reactions
Authors: Hoffmann Norbert
Published: February 2017

Proton‐coupled electron transfer (PCET) is studied in different research domains of chemistry. Many reports involve biochemical processes. Although related phenomena have often been investigated in photochemical electron‐ and hydrogen‐transfer processes, only recently have a larger variety of such steps come to be discussed under the comprehensive concept of PCET. In photoredox catalytic reactions applied to organic synthesis, various PCET steps have been identified in cases in which redox or simple electron‐transfer steps are estimated to be endergonic by simple comparison of redox potentials. Such steps become exergonic when the electron transfer is coupled with proton transfer. In this article, examples of photoredox catalytic reactions of synthetic interest are reported, with the PCET discussed in detail.
Pyrimidines as Surrogates for 1,3‐Dicarbonyl Compounds in peri Annulation of Perimidines en Route to 1,3‐Diazapyrenes
Authors: Aksenov Alexander V. , Shcherbakov Stanisvlav V. , Lobach Irina V. , Aksenova Inna V. , Rubin Michael
Published: February 2017

A highly efficient protocol for acid‐mediated peri annulation of perimidines with pyrimidines has been developed. Pyrimidines, used as surrogates for 1,3‐dicarbonyl compounds, furnish benzo[gh]perimidines, which includes hardly available analogues, non‐substituted, or mono‐substituted at C‐6, C‐8. Limitations of reactions that use 5‐bromopyrimidines are investigated.
Effective withdrawal of antiepileptic drugs in premonitoring admission to capture seizures during limited video‐EEG monitoring
Authors: Kagawa Kota , Iida Koji , Baba Shiro , Hashizume Akira , Katagiri Masaya , Kurisu Kaoru , Otsubo Hiroshi
Published: February 2017

Objective

Withdrawal of antiepileptic drugs (AEDs) is commonly applied to capture seizures in video‐EEG (vEEG) monitoring for patients with infrequent but intractable seizures. Because of the half‐life of AEDs, AED withdrawal during only vEEG tends to be inadequate to provoke seizures within the vEEG admission. We hypothesize that prewithdrawal of long‐half‐life AEDs in premonitoring admission (PMA) is safe and effective to capture seizures in the limited time of vEEG. We determined the effect of half‐life on the interval between AED withdrawal and seizure occurrence.

Methods

We collected 87 patients with three criteria: (1) seizure occurrence ≤3 per month; (2) AEDs ≥2; (3) AED withdrawal during their admission, among 126 consecutive patients who underwent vEEG in the Department of Neurosurgery, Hiroshima University Hospital between 2011 and 2014. We divided patients into two groups on the basis of half‐life of AED: Group A (23 patients) with phenobarbital (PB) and/or zonisamide (ZNS); Group B (64 patients) with other AEDs. In Group A, PB and ZNS were withdrawn during 4‐day PMA before vEEG started. Further AED withdrawal was performed during vEEG, depending on the seizure occurrence.

Results

The number of AEDs on admission was significantly higher in Group A (2–6, 3.5 ± 0.9; range, mean ±SD) than in Group B (2–5, 2.8 ± 0.8) (p < 0.01). All 23 Group A patients and 13 (20%) Group B patients underwent AED withdrawal during PMA. Seizures occurred during PMA in two patients in both Group A (9%) and Group B (15%). The first seizure occurred significantly longer after the start of withdrawal in Group A (6.1 ± 2.0 days) than in Group B (2.8 ± 1.3 days) (p < 0.01). Seizures were equally captured between both groups: 96% in Group A and 92% in Group B during vEEG.

Significance

For epilepsy patients who are treated with PB and/or ZNS, we recommend the planning of AED withdrawal during PMA before the start of vEEG to succeed in capturing seizures during the limited time of vEEG monitoring.
Toxicity of sulfide to early life stages of wild rice (Zizania palustris)
Authors: Fort Douglas J. , Todhunter Kevin , Fort Troy D. , Mathis Michael B. , Walker Rachel , Hansel Mike , Hall Scott , Richards Robin , Anderson Kurt
Published: February 2017

The sensitivity of wild rice (Zizania palustris) to sulfide is not well understood. Because sulfate in surface waters is reduced to sulfide by anaerobic bacteria in sediments and historical information indicated that 10 mg/L sulfate in Minnesota (USA) surface water reduced Z. palustris abundance, the Minnesota Pollution Control Agency established 10 mg/L sulfate as a water quality criterion in 1973. A 21-d daily-renewal hydroponic study was conducted to evaluate sulfide toxicity to wild rice and the potential mitigation of sulfide toxicity by iron (Fe). The hydroponic design used hypoxic test media for seed and root exposure and aerobic headspace for the vegetative portion of the plant. Test concentrations were 0.3, 1.6, 3.1, 7.8, and 12.5 mg/L sulfide in test media with 0.8, 2.8, and 10.8 mg/L total Fe used to evaluate the impact of iron on sulfide toxicity. Visual assessments (i.e., no plants harvested) of seed activation, mesocotyl emergence, seedling survival, and phytoxicity were conducted 10 d after dark-phase exposure. Each treatment was also evaluated for time to 30% emergence (ET30), total plant biomass, root and shoot lengths, and signs of phytotoxicity at study conclusion (21 d). The results indicate that exposure of developing wild rice to sulfide at ≥3.1 mg sulfide/L in the presence of 0.8 mg/L Fe reduced mesocotyl emergence. Sulfide toxicity was mitigated by the addition of Fe at 2.8 mg/L and 10.8 mg/L relative to the control value of 0.8 mg Fe/L, demonstrating the importance of iron in mitigating sulfide toxicity to wild rice. Ultimately, determination of site-specific sulfate criteria taking into account factors that alter toxicity, including sediment Fe and organic carbon, are necessary. Environ Toxicol Chem 2017;36:2217–2226. © 2017 SETAC
Modeling of natural convection and radiative heat transfer in inclined thermosyphon system installed in the roof of a building
Authors: Ababsa Dalila , Bougoul Saadi
Published: February 2017

Some construction laws require the integration of an open thermosyphon system having multiple functions to the building roof. In order to analyze the efficiency of this system, a numerical model was developed. This model is based on the study of the natural convection coupled with radiative heat transfer in an inclined air channel. Two configurations are studied, the first one is a simple channel formed by two parallel plates and the second one is equipped with fin blades joined to the upper plate. The air flow in the channel which is due to the buoyancy forces is fully turbulent and the turbulence was modeled using the k‐ε model. Some numerical results obtained were validated using the experimental ones of Khedari et al. (2002) and those of Nouanégué and Bilgen (2009). The effect of the radiative heat transfer on the mean Nusselt number was shown. Correlations for Nusselt numbers were obtained for the two configurations as functions of the geometric parameters and the Rayleigh number. The main objective of this study is to use these correlations in other models to facilitate the operation of this system
Effect of Human Serum on Killing Activity of Vancomycin and Teicoplanin against Staphylococcus aureus
Authors: Stanley Denise , McGrath Betty J. , Lamp Kenneth C. , Rybak Michael J.
Published: February 2017

Study Objective. To investigate the effects of pooled human serum (PHS) on the killing activity of vancomycin and teicoplanin against two isolates of Staphylococcus aureus from patients treated for endocarditis.

Design. An in vitro assessment of antibiotic susceptibility and killing rates.

Setting. An urban university teaching hospital.

Patients. Pooled human serum from patients treated for endocarditis.

Interventions. Two clinical isolates of Staphylococcus aureus were obtained from patients treated for endocarditis. Media consisted of cation‐supplemented Mueller‐Hinton broth alone and in 1:1 dilutions with PHS, 2‐hour heat‐inactivated PHS (HI‐PHS), ultrafiltrate (UF), and 2‐hour heat‐inactivated ultrafiltrate (HI‐UF). Heat inactivation of PHS and UF was accomplished by treatment at 56°C for 2 hours.

Measurements and Main Results. Killing curves with vancomycin and teicoplanin were performed using drug concentrations of 45 μg/ml and a starting inoculum of ∼1 × 106 colony‐forming units (cfu)/ml. Bactericidal rates (‐log cfu/ml/hr) were calculated from the slope of the killing curves over 0–12 hours (mean 3–8 replicates).

Conclusions. The killing activity of vancomycin in PHS and HI‐PHS against both isolates was significantly greater than all other media tested (p<0.0001). Ultrafiltrate tended to reverse this enhancement effect. Addition of PHS or UF did not enhance teicoplanin's killing activity against either isolate. Further investigations in our laboratory will determine if the factor is antibiotic class or organism specific.
Accumulation of Clarithromycin in Macrophages Infected With Mycobacterium avium
Authors: Mor Natan , Vanderkolk Julie , Heifets Leonid
Published: February 2017

Clarithromycin is known to accumulate in polymorphonuclear leukocytes, but no accumulation studies with macrophages have been reported. We exposed J774 macrophages, grown for 4–6 days, to clarithromycin 3.0 μg/ml for 2 hours. The cells were separated from the extracellular fluid, and the concentration of clarithromycin was determined in an agar diffusion bioassay. The accumulation of clarithromycin was 15.8‐fold greater in the cells than it was in the extracellular fluid when the test was performed with noninfected cells, and 17.3‐fold greater for cells infected with Mycobacterium avium. However, the ratio was substantially lower, only 3.7 for dead macrophages, suggesting that intracellular accumulation is probably an active process. These data may clarify the nature of the activity of clarithromycin against M. avium in macrophages.
NMDA receptor subunit composition controls dendritogenesis of hippocampal neurons through CAMKII, CREB‐P, and H3K27ac
Authors: Bustos Fernando J. , Jury Nur , Martinez Pablo , Ampuero Estibaliz , Campos Matias , Abarzúa Sebastian , Jaramillo Karen , Ibing Susanne , Mardones Muriel D. , Haensgen Henny , Kzhyshkowska Julia , Tevy Maria Florencia , Neve Rachael , Sanhueza Magdalena , Varela‐Nallar Lorena , Montecino Martín , van Zundert Brigitte
Published: February 2017

Dendrite arbor growth, or dendritogenesis, is choreographed by a diverse set of cues, including the NMDA receptor (NMDAR) subunits NR2A and NR2B. While NR1NR2B receptors are predominantly expressed in immature neurons and promote plasticity, NR1NR2A receptors are mainly expressed in mature neurons and induce circuit stability. How the different subunits regulate these processes is unclear, but this is likely related to the presence of their distinct C‐terminal sequences that couple different signaling proteins. Calcium‐calmodulin‐dependent protein kinase II (CaMKII) is an interesting candidate as this protein can be activated by calcium influx through NMDARs. CaMKII triggers a series of biochemical signaling cascades, involving the phosphorylation of diverse targets. Among them, the activation of cAMP response element‐binding protein (CREB‐P) pathway triggers a plasticity‐specific transcriptional program through unknown epigenetic mechanisms. Here, we found that dendritogenesis in hippocampal neurons is impaired by several well‐characterized constructs (i.e., NR2B‐RS/QD) and peptides (i.e., tatCN21) that specifically interfere with the recruitment and interaction of CaMKII with the NR2B C‐terminal domain. Interestingly, we found that transduction of NR2AΔIN, a mutant NR2A construct with increased interaction to CaMKII, reactivates dendritogenesis in mature hippocampal neurons in vitro and in vivo. To gain insights into the signaling and epigenetic mechanisms underlying NMDAR‐mediated dendritogenesis, we used immunofluorescence staining to detect CREB‐P and acetylated lysine 27 of histone H3 (H3K27ac), an activation‐associated histone tail mark. In contrast to control mature neurons, our data shows that activation of the NMDAR/CaMKII/ERK‐P/CREB‐P signaling axis in neurons expressing NR2AΔIN is not correlated with increased nuclear H3K27ac levels.
A new real‐time RT‐PCR targeting VP4‐VP2 to detect and quantify enterovirus D68 in respiratory samples
Authors: Royston Léna , Geiser Johan , Josset Laurence , Schuffenecker Isabelle , Tapparel Caroline
Published: February 2017

Causing an international outbreak of respiratory disease, Enterovirus D68 quickly entered the closed circle of emerging viral pathogens of public health significance. As rapid and accurate detection of EV‐D68 is essential for an efficient clinical management, we designed and validated a new highly efficient one‐step quantitative rRT‐PCR specific to EV‐D68 VP4‐VP2 region. With 100% specificity and 95.6% sensitivity to all EV‐D68 strains, this new assay can be reliably used to detect and quantify EV‐D68 in respiratory samples and represents an interesting additional tool for diagnosis as it targets an original region of the genome.
Light and Temperature Requirements during Germination of Potential Perennial Grasses for Rehabilitation of Degraded Sandy Arabian Deserts
Authors: El‐Keblawy Ali
Published: February 2017

Few plants can tolerate the loose sandy‐soils of the arid deserts. Selection of native plants that could be used in rehabilitation of degraded deserts necessitates information about their seed dormancy and germination requirements. This study assessed the effects of light and temperature requirements during germination for eight common perennial grasses that have the potential to rehabilitate the arid Arabian deserts. The selected grasses vary considerably in seed mass. Germination of clonally propagated grasses (six species) was significantly greater, but slower, than that of two non‐clonal grasses. Four of these six species (Lasiurus scindicus, Panicum turgidum, Aeluropus lagopoides and Halopyrum mucronatum) produce larger seeds and attained greater germination in both light and darkness at a wide range of temperatures. However, the other two (Centropodia forsskaolii and Coelachyrum piercei) produce medium‐sized seeds with higher dormancy. Smaller seeds of Sporobolus arabicus were positively photoblastic at all temperatures, but those of Sporobolus spicatus were neutrally photoblastic at lower temperatures and positively photoblastic at higher temperatures. There was a significant negative relationship between seed mass and relative light germination, indicating that small seeds require more light during germination. It is recommended to use seeds of the six clonal grasses for restoration of degraded arid deserts. The ability of these grasses to germinate in different light and temperature regimes indicates their ability to germinate at any time of the year, even when seeds are buried. The light and temperature requirements of the different grasses are explained in the light of their adaptation and distribution in natural habitats. Copyright © 2017 John Wiley & Sons, Ltd.
Bioprinting Using Mechanically Robust Core–Shell Cell‐Laden Hydrogel Strands
Authors: Mistry Pritesh , Aied Ahmed , Alexander Morgan , Shakesheff Kevin , Bennett Andrew , Yang Jing
Published: February 2017

The strand material in extrusion‐based bioprinting determines the microenvironments of the embedded cells and the initial mechanical properties of the constructs. One unmet challenge is the combination of optimal biological and mechanical properties in bioprinted constructs. Here, a novel bioprinting method that utilizes core–shell cell‐laden strands with a mechanically robust shell and an extracellular matrix‐like core has been developed. Cells encapsulated in the strands demonstrate high cell viability and tissue‐like functions during cultivation. This process of bioprinting using core–shell strands with optimal biochemical and biomechanical properties represents a new strategy for fabricating functional human tissues and organs.

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Effects of Hydrophobic Modifications and Phase Transitions of Polyvinylamine Hydrogel Films on Reversible CO2 Capture Behavior: Comparison between Copolymer Films and Blend Films for Temperature‐Responsive CO2 Absorption
Authors: Yue Mengchen , Imai Kenta , Yamashita Chie , Miura Yoshiko , Hoshino Yu
Published: February 2017

The separation of CO2 from large emission sources is essential to both mitigate the greenhouse effect, as well as generate carbon‐based energy. However, energy consumption of conventional CO2 separation processes, which using aqueous amine solution as absorbent, is too large. It is has been previously reported that hydrogel films that are consisting of temperature‐responsive amine‐containing polymers can be energy efficient CO2 absorbent—the films can reversibly capture and release large amount of CO2 via temperature‐induced phase transition of hydrogels. However, the study is limited to the films consisting of gel particles of polyacrylamides. In this study, a series of hydrogel films consisting of a mass‐produced amine‐containing linear polymer, polyvinyl amine (PVAm), are prepared, and the efficiencies of their reversible CO2 capture are tested. The effects of hydrophobic modifications and the temperature dependent phase transition behaviors of the films on the reversible CO2 capture efficiency are studied in detail. The function of hydrogel films containing modified PVAm (copolymers), as well as blend films of nonmodified PVAm and 100% modified PVAm, are compared for the first time. The results reveal that the reversible CO2 capture efficiency of polyamine films can be improved just by blending with temperature‐responsive polymers.

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Light‐Switchable Self‐Healing Hydrogel Based on Host–Guest Macro‐Crosslinking
Authors: Yang Qiaofeng , Wang Ping , Zhao Chuanzhuang , Wang Wenqin , Yang Jingfa , Liu Qiao
Published: February 2017

A self‐healing hydrogel is prepared by crosslinking acrylamide with a host–guest macro‐crosslinker assembled from poly(β‐cyclodextrin) nanogel and azobenzeneacrylamide. The photoisomerizable azobenzene moiety can change its binding affinity with β‐cyclodextrin, therefore the crosslinking density and rheology property of the hydrogel can be tuned with light stimulus. The hydrogel can repair its wound autonomously through the dynamic host–guest interaction. In addition, the wounded hydrogel will lose its ability of self‐healing when exposed to ultraviolet light, and the self‐healing behavior can be recovered upon the irradiation of visible light. The utilizing of host–guest macro‐crosslinking approach manifests the as‐prepared hydrogel reversible and light‐switchable self‐healing property, which would broaden the potential applications of self‐healing polymers.

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Understanding surface discharge activity with epoxy silicon carbide nanocomposites
Authors: Sarathi Ramanujam , Sahoo Animesh , Chen Yu , Cheng Yonghong , Tanaka Toshikatsu
Published: February 2017

Surface discharge inception voltage (SDIV) with epoxy silicon carbide nanocomposite material in LN2 medium is about three times higher than that in air. Under AC voltage that SDIV increases with increase in wt% of silicon carbide (SIC) material in epoxy nanocomposites. Dielectric measurements indicates an increase in temperature of the specimen and the weight percentage of SIC filler in epoxy resin increases the permittivity of the material. Also, irrespective of percentage of SiC in epoxy resin, the tan(δ) reduces with increase in frequency and the converse at room temperature. The UHF signal measured during surface discharge activity in air/LN2 medium has frequency content in the range of 0.5–1.5 GHz. The charge decay characteristics of epoxy SiC nanocomposites indicate the deposited charge is less and the charge decay time reduces with increase in wt% of SiC in epoxy resin. The surface roughness caused due to surface discharge activity is high under negative DC voltage compared with positive DC/AC voltage. The phase resolved partial discharge (PRPD) analysis indicates discharges occur at the near peak of the AC voltage on inception of surface discharge and at higher stress it appears at the rising portion of AC voltage. POLYM. ENG. SCI., 57:1349–1355, 2017. © 2017 Society of Plastics Engineers
Ion transport properties of mechanically stable symmetric ABCBA pentablock copolymers with quaternary ammonium functionalized midblock
Authors: Ertem S. Piril , Caire Benjamin R. , Tsai Tsung‐Han , Zeng Di , Vandiver Melissa A. , Kusoglu Ahmet , Seifert Soenke , Hayward Ryan C. , Weber Adam Z. , Herring Andrew M. , Coughlin E. Bryan , Liberatore Matthew W.
Published: February 2017

Anion exchange membranes (AEMs) are a promising class of materials for applications that require selective ion transport, such as fuel cells, water purification, and electrolysis devices. Studies of structure–morphology–property relationships of ion‐exchange membranes revealed that block copolymers exhibit improved ion conductivity and mechanical properties due to their microphase‐separated morphologies with well‐defined ionic domains. While most studies focused on symmetric diblock or triblock copolymers, here, the first example of a midblock quaternized pentablock AEM is presented. A symmetric ABCBA pentablock copolymer was functionalized to obtain a midblock brominated polymer. Solution cast films were then quaternized to obtain AEMs with resulting ion exchange capacities (IEC) ranging from 0.4 to 0.9 mmol/g. Despite the relatively low IEC, the polymers were highly conductive (up to 60 mS/cm Br− at 90 °C and 95%RH) with low water absorption (<25 wt %) and maintained adequate mechanical properties in both dry and hydrated conditions. X‐ray scattering and transmission electron microscopy (TEM) revealed formation of cylindrical non‐ionic domains in a connected ionic phase. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 612–622
Targeting human SET1/MLL family of proteins
Authors: Vedadi Masoud , Blazer Levi , Eram Mohammad S. , Barsyte‐Lovejoy Dalia , Arrowsmith Cheryl H. , Hajian Taraneh
Published: February 2017

The SET1 family of proteins, and in particular MLL1, are essential regulators of transcription and key mediators of normal development and disease. Here, we summarize the detailed characterization of the methyltransferase activity of SET1 complexes and the role of the key subunits, WDR5, RbBP5, ASH2L, and DPY30. We present new data on full kinetic characterization of human MLL1, MLL3, SET1A, and SET1B trimeric, tetrameric, and pentameric complexes to elaborate on substrate specificities and compare our findings with what has been reported before. We also review exciting recent work identifying potent inhibitors of oncogenic MLL1 function through disruption of protein–protein interactions within the MLL1 complex.
Adsorption of polycyclic aromatic hydrocarbons onto graphyne: Comparisons with graphene
Authors: Cortés‐Arriagada Diego
Published: February 2017

Density functional theory calculations were implemented to expand the knowledge about graphyne and its interaction with polycyclic aromatic hydrocarbons (PAHs). Due to the porous character of graphyne, the adsorption strength of PAHs onto graphyne surfaces is expected to be lower with respect to graphene (a perfect π‐extended system). However, there are not quantitative evidences for this assumption. This work shows that the adsorption strength of adsorbed PAHs onto γ‐graphyne nanosheets (GY) is weakened in 12 − 23% with respect to the adsorption onto graphene, with a decrease of 10 − 20% in the dispersive interactions. The adsorption energies (in eV) of the GY–PAH systems can be straightforward obtained as Eads/eV≈0.033NH + 0.031NC, where NH and NC is the number of H and C atoms in the aromatic molecule, respectively. This equation predicts the binding energy of graphene–graphyne bilayers with a value of ∼31 meV/atom. Analysis of the electronic properties shows that PAHs behaves as n‐dopants for GY, introducing electrons in GY and also reducing its bandgap in up to ∼0.5 eV. Strong acceptor or donor substituted PAHs decrease the bandgap of γ‐graphyne in up to ∼0.8 eV, with changes in its valence or conduction band, depending on the chemical nature of the adsorbate. Finally, these data will serve for future studies related to the bandgap engineering of graphyne surfaces by nonaggressive molecular doping, and for the development of graphyne‐based materials with potential applications in the removal of persistent aromatic pollutants.
A Regioselective Multicomponent Cascade to Access Thiosemicarbazone–fused Thiazinones: Scope, Structure Elucidation and Gram Scale Synthesis
Authors: Wadhwa Preeti , Bagchi Sourav , Sharma Anuj
Published: February 2017

A novel synthesis of thiosemicarbazone fused thiazinones is described via solvent free multicomponent reaction of readily available thiosemicarbazide or thiocarbohydrazide, aldehydes and dialkyl acetylenedicarboxylates. The merit of this cascade thiosemicarbazone formation/Michael addition/cyclization sequence is highlighted by its high atom‐economy and efficiency of producing three or four new bonds (one or two C=N, one C−S and one C−N) in a single operation with 100% regioselectivity. The structure was unambiguously assigned by 2D‐NMR. Short reaction time, operational simplicity, excellent yields, gram scale‐up and no chromatographic purification in the entire process makes the protocol very useful for academia and industry.
Host‐Guest Chemistry of Linked β‐ and γ‐Cyclodextrin Dimers and 1‐ and 2‐Naphthyl‐Sulfonamide Substituted Poly(acrylate)s in Aqueous Solution
Authors: McTernan Hamish L. , Ngo Huy T. , Pham Duc‐Truc , Clements Philip , Lincoln Stephen F. , Wang Jie , Guo Xuhong , Easton Christopher J.
Published: February 2017

Host‐guest complexation by β‐ and γ‐cyclodextrin and their four succinamide‐linked dimers of the naphthyl substituents of four randomly substituted poly(acrylate)s in twenty‐four aqueous systems has been characterised. Complexation occurs through entry of the naphthyl substituents into the cyclodextrin annuli. The naphthyl substitution position, the length of the tether attaching the naphthyl substituent to the poly(acrylate) backbone and the size and stereochemistry of the cyclodextrin hosts determine the relative stabilities of poly(acrylate) intra‐strand complexes in dilute solution and the formation of inter‐strand cross‐links in more concentrated solution.
Ni‐Catalyzed Synthesis of Methylenebisamides: Dual Role of DMSO Both as Methylene Source and Oxidant
Authors: Moghaddam Firouz Matloubi , Tavakoli Ghazal , Saeednia Borna
Published: February 2017

A simple and efficient procedure for the synthesis of methylenebisamides using a nickel‐catalyzed C−S bond cleavage of DMSO was achieved. Remarkable results obtained from mechanistic experiments clearly show that DMSO plays a dual role in this transformation; both as an economical and environmentally benign one‐carbon synthon and an oxidizing agent. Also, based on these mechanistic studies, a mechanism was proposed for the formation of methylenebisamide. Both (hetero)aromatic and pseudo‐aromatic nitriles and amides can be employed for the synthesis of methylenebisamides. The results of robustness screen analyses further showed that the procedure is of high tolerance to different chemical functionalities and chemical motifs. The optimized conditions are scalable with very good to excellent yields and the process is atom‐economic. Moreover, purified products were obtained in good to excellent yields through a facile crystallization procedure.
Evaluation of 6‐Deoxy–amino–sugars as Potent Glycosidase Inhibitors. Importance of the CH2OH(6) Group for Enzyme‐Substrate Interaction
Authors: Sarazin Hervé , Prudent Sandrine , Defoin Albert , Tarnus Céline
Published: February 2017

Optically active or racemic 6‐deoxy‐analogues of the nojirimycine d‐1 a in allose, glucose, fucose, talose and gulose series were evaluated as glycosidase inhibitors. These compounds were analysed either as their sulfite adducts or as the “true” amino‐sugars (the exact copies of aldoses with intracyclic oxygen replaced by nitrogen) or as their reduced 1‐deoxy‐form depending on the series. Some compounds are potent inhibitors of α‐ and β‐d‐glucosidases and α‐ and β‐d‐galactosidases. Racemic compounds in talose and gulose series were also micromolar inhibitors of α‐l‐fucosidase and β‐d‐galactosidase, while the talose analogues were active against β‐d‐mannosidase. Comparison of these inhibition data with those of amino‐hexoses possessing the CH2OH group permitted to evaluate the implication of the C(6)‐OH in enzyme‐inhibitor interactions, which seem to occur particularly with α‐d‐glucosidase (yeast) and α‐d‐galactosidase (green coffee beans). The cases of the β‐d‐glucosidase and β‐d‐galactosidase were discussed.
Support vector classification and regression for fault location in distribution system using voltage sag profile
Authors: Gururajapathy Sophi Shilpa , Mokhlis Hazlie , Illias Hazlee Azil Bin , Awalin Lilik Jamilatul
Published: February 2017

Fault location identification is an important task to provide reliable service to the customer. Most existing artificial intelligence methods such as neural network, fuzzy logic, and support vector machine (SVM) focus on identifying the fault type, section, and distance separately. Furthermore, studies on fault type identification are focused on overhead transmission systems and not on underground distribution systems. In this paper, a fault location method in the distribution system is proposed using SVM, addressing the limitations of existing methods. Support vector classification (SVC) and regression analysis are performed to locate the fault. The method uses the voltage sag data during a fault measured at the primary substation. The type of fault is identified using SVC. The fault resistance and the voltage sag for the estimated fault resistance are identified using support vector regression (SVR) analysis. The possible faulty sections are identified from the estimated voltage sag data and ranked using the Euclidean distance approach. The proposed method identifies the fault distance using SVR analysis. The performance of the proposed method is analyzed using Malaysian distribution system of 40 buses. Test results show that the proposed method gives reliable fault location.
Chaotic complex‐valued bipartite auto‐associative memory with a periodic activation function
Authors: Kobayashi Masaki
Published: February 2017

A Hopfield associative memory (HAM) can store binary data. A HAM has been extended to a complex‐valued HAM (CHAM) which can store multi‐level data. A CHAM has often been applied to the storage of grayscale images. A CHAM has a problem of rotational invariance, which makes many psuedomemories and reduces the noise tolerance. A chaotic CHAM can explore the stored patterns, though it recalls many pseudomemories. A complex‐valued bipartite auto‐associative memory (CBAAM) was proposed to improve the noise tolerance by solving rotational invariance. Since a CBAAM stores the reversed patterns, a chaotic CBAAM (CCBAAM) recalls both the training and reversed patterns. In order to solve this problem, a periodic activation function is introduced. A periodic activation function identifies the training and reversed patterns, so that a CCBAAM does not recall the reversed patterns. We evaluate our proposed CCBAAM by computer simulations. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Electrostatic thunderstorm detection
Authors: Bennett A. J.
Published: February 2017

Thunderstorm detection within 100km using a single sensor to measure the variation in electrostatic field between 1 and 45Hz is discussed. Case studies demonstrating the use of electrostatic variability in lightning detection and warning of overhead thunderstorm development are presented, including the ability to locate lightning when electrostatic signals are combined with radio direction finding.
Saccharomyces cerevisiae Atf1p is an alcohol acetyltransferase and a thioesterase in vitro
Authors: Nancolas Bethany , Bull Ian D. , Stenner Richard , Dufour Virginie , Curnow Paul
Published: February 2017

The alcohol‐O‐acyltransferases are bisubstrate enzymes that catalyse the transfer of acyl chains from an acyl‐coenzyme A (CoA) donor to an acceptor alcohol. In the industrial yeast Saccharomyces cerevisiae this reaction produces acyl esters that are an important influence on the flavour of fermented beverages and foods. There is also a growing interest in using acyltransferases to produce bulk quantities of acyl esters in engineered microbial cell factories. However, the structure and function of the alcohol‐O‐acyltransferases remain only partly understood. Here, we recombinantly express, purify and characterize Atf1p, the major alcohol acetyltransferase from S. cerevisiae. We find that Atf1p is promiscuous with regard to the alcohol cosubstrate but that the acyltransfer activity is specific for acetyl‐CoA. Additionally, we find that Atf1p is an efficient thioesterase in vitro with specificity towards medium‐chain‐length acyl‐CoAs. Unexpectedly, we also find that mutating the supposed catalytic histidine (H191) within the conserved HXXXDG active site motif only moderately reduces the thioesterase activity of Atf1p. Our results imply a role for Atf1p in CoA homeostasis and suggest that engineering Atf1p to reduce the thioesterase activity could improve product yields of acetate esters from cellular factories. © 2017 The Authors. Yeast published by John Wiley & Sons, Ltd.
Assessing the Size of Model Misfit in Structural Equation Models
Authors: Maydeu-Olivares Alberto
Published: February 2017

When a statistically significant mean difference is found, the magnitude of the difference is judged qualitatively using an effect size such as Cohen’s d. In contrast, in a structural equation model (SEM), the result of the statistical test of model fit is often disregarded if significant, and inferences are drawn using “close” models retained based on point estimates of sample statistics (goodness-of-fit indices). However, when a SEM cannot be retained using a test of exact fit, all substantive inferences drawn from it are suspect. It is therefore important to determine the size of the model misfit. Standardized residual covariances and residual correlations provide standardized effect sizes of the misfit of SEM models. They can be summarized using the Standardized Root Mean Squared Residual (SRMSR) and the Correlation Root Mean Squared Residual (CRMSR) which can be used as overall effect sizes of the misfit. Statistical theory is provided that allows the construction of confidence intervals and tests of close fit based on the SRMSR and CRMSR. It is hoped that the use of standardized effect sizes of misfit will help reconcile current practices in SEM and elsewhere in statistics.
Changes in Lipid and Fatty Acid Composition During Intramacrophagic Transformation of Leishmania donovani Complex Promastigotes into Amastigotes
Authors: Bouazizi‐Ben Messaoud Hana , Guichard Marion , Lawton Philippe , Delton Isabelle , Azzouz‐Maache Samira
Published: February 2017

Leishmania sp., are trypanosomatid parasites that are phagocytized by human and animal macrophages. Transformation from the vector promastigote stage to the intracellular amastigote host cell stage is mandatory, since development in the host depends on the internalization of the parasite. We identified and analyzed the lipids involved in the promastigote to amastigote transformation process in the Leishmania donovani complex. Four lipid classes, phospholipids, free fatty acids, triglycerides and sterols were studied. The derivatization method of Bligh and Dyer was used to establish the fatty acid composition in each stage of the parasite. To stay within the context of Leishmania infection, we used amastigotes extracted from macrophages after experimental in vitro infection. The purification process was checked by electronic microscopy, the absence of major contamination by host‐cell debris and a correct purification yield validated our experimental model. Our results show that free fatty acids and cholesterol increased, whereas triglycerides and ergosterol decreased during the transition between promastigotes to amastigotes. With respect to phospholipid classes, we found increased proportion of sphingomyelin and phosphatidylserine and lowered proportion of phosphatidylinositol and lysophosphatidylethanolamine. Regarding fatty acid composition, a significant increase of n‐7 fatty acids was observed in amastigotes. Overall, the total n‐6 fatty acids were decreased in PL. Several of the changes were also observed in TG and free fatty acids. Particularly, n‐7 fatty acids and 20:4n‐6 were highly increased, whereas n‐9 fatty acid and n‐6 precursors decreased.
Recovery, relapse, or else? Treatment outcomes in gambling disorder from a multicenter follow-up study
Authors: Müller K.W. , Wölfling K. , Dickenhorst U. , Beutel M.E. , Medenwaldt J. , Koch A.
Published: February 2017

Purpose:

Gambling disorder is associated with various adverse effects. While data on the immediate effectiveness of treatment programs are available, follow-up studies examining long-term effects are scarce and factors contributing to a stable therapy outcome versus relapse are under-researched.

Materials and methods:

Patients (n = 270) finishing inpatient treatment for gambling disorder regularly participated in a prospective multicenter follow-up study (pre-treatment, post-treatment, 12-month follow-up). Criteria for gambling disorder, psychopathology, functional impairment were defined as endpoints. Changes in personality were defined as an additional parameter.

Results:

At follow-up, three groups were identified: subjects maintaining full abstinence (41.6%), patients still meeting criteria for gambling disorder (29.2%), and subjects still participating in gambling without meeting the diagnostic criteria for gambling disorder (29.2%). Every group had improvements in functional impairment, abstinent subjects showed the lowest psychopathology. Significant decreases in neuroticism and increases in both extraversion and conscientiousness were found among abstinent subjects but not in patients still meeting criteria for gambling disorder.

Discussion:

One year after treatment, a considerable percentage of patients kept on gambling but not all of them were classified with gambling disorder leading to the question if abstinence is a necessary goal for every patient.

Conclusions:

The changes of personality in abstinent patients indicate that after surmounting gambling disorder a subsequent maturing of personality might be a protective factor against relapse.
Age‐Related Changes in Morphology and Function of Scapular Muscles in Asymptomatic People
Authors: Morise Shuhei , Muraki Takayuki , Ishikawa Hiroaki , Izumi Shin‐Ichi
Published: February 2017

Background

Aging is a contributing factor to rotator cuff tears. Dysfunction of the scapular muscles can be a potential cause of rotator cuff tears. Although aging can contribute to dysfunction of the scapular muscles and subsequently result in rotator cuff tears, the effects of aging on scapular muscles are unclear.

Objective

To determine changes in sizes and electromyographic activities of the scapular muscles with age in asymptomatic subjects.

Design

Cross‐sectional study.

Patients

Fifty‐four asymptomatic subjects without shoulder pain and dysfunction (18 male and 36 female) were recruited for this study. Subjects consisted of 19 people aged 20‐39 years (young adult group, 27.2 ± 5.2 years), 17 people aged 40‐59 years (middle age group, 49.9 ± 6.6 years), and 18 people aged 60‐79 years (elderly group, 68.0 ± 7.1 years).

Methods

Using ultrasonography, we measured the muscle thickness of the trapezius (upper and lower portions), serratus anterior, and middle deltoid muscles during rest with the subject in a sitting position. Activities of the same muscles were measured with surface electromyography during shoulder elevation in the scapular plane up to 120°. The electromyographic data were analyzed at ranges 0°‐30°, 30°‐60°, and 60°‐90°. Analysis of variance and Bonferroni multiple comparisons were used for statistical analysis.

Results

Muscle thickness of the lower trapezius in the elderly group was decreased significantly compared with that in the young adult group (95% confidence interval −0.40, 2.24; P < .001) and middle age group (95% confidence interval −0.34, 1.89; P = .012). There were no significant differences in muscle activity and activity ratio between groups.

Conclusion

In scapular muscles, muscle thickness of the lower trapezius significantly decreased with aging, although there were no decreases in muscle thicknesses of the other muscles between different age groups. For the functional change, aging may not affect the scapular muscle activities and balance of the activities between the deltoid and scapular muscles.

Level of Evidence

IV
On positive Liouville theorems and asymptotic behavior of solutions of Fuchsian type elliptic operators
Authors: Pinchover Yehuda
Published: February 2017

Using the Harnack inequality and a scaling argument we prove some positive Liouville theorems for a Fuchsian type linear elliptic operator

P

on some domains in

ℝ^d

with some prescribed boundary conditions. We also study the asymptotic behavior of the quotients of two positive solutions of linear and semilinear equations.

Avec l’aide de l’inégalité de Harnack et d’un argument de scaling nous démontrons des théorèmes de type Liouville pour des fonctions

P

-harmoniques positives d’un opérateur linéaire elliptique

P

de type fuchsien sur certaines régions de

ℝ^d

avec conditions limites. Nous étudions également le comportement asymptotique des quotients de deux solutions positives des équations linéaires et semi-linéaires.
Continuous dependence in L2 for discontinuous solutions of the viscous p-system
Authors: Hoff David , Zarnowski Roger
Published: February 2017

We prove that discontinuous solutions of the Navier–Stokes equations for isentropic or isothermal flow depend continuously on their initial data in

L^2

. This improves earlier results in which continuous dependence was known only in a much stronger norm, a norm inappropriately strong for the physical model. We also apply our continuous dependence theory to obtain improved rates of convergence for certain finite difference approximations.

Nous prouvons que les solutions discontinues des équations de Navier–Stokes, pour des flots isentropiques ou isothermaux, dépendent continuement des conditions initiales dans

L^2

. Ceci améliore les résultats précédents dans lesquels la continuité de la dépendance n’était connue que pour une norme beaucoup plus forte, inappropriée pour le modèle physique. Nous appliquons aussi cette théorie de la dépendance continue pour obtenir une amélioration des taux de convergence pour certaines approximations aux différences finies.
On distribution functions of the derivatives of weakly differentiable mappings
Authors: Mizel Victor J.
Published: February 2017

In this paper I describe and resolve affirmatively the following question: For a function on the unit interval possessing an absolutely continuous first derivative, does the joint distribution of the function and its first derivative fully determine the distribution of the second derivative? I also describe some consequences and extensions of the result.

Dans ce travail nous abordons et résolvons affirmativement la question suivante: Soit une fonction réelle définie sur l’intervalle [0, 1] et dotée d’une dérivée première absolument continue. Est-ce que la distribution conjointe de la fonction et de sa dérivée première détermine complètement la distribution de la dérivée seconde? Nous décrivons quelques conséquences et généralisations de ce résultat.