bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of finite element method for electro‐thermal modeling of metal oxide surge arrester
Authors: Seyyedbarzegar Seyyed Meysam , Mirzaie Mohammad 
Published: June 2015

ABSTRACTAnalysis of electro‐thermal behavior in various operating condition based on finite element method was proposed in this article. Power frequency and impulse stresses vary the operating region and temperature of surge arresters. Therefore, adaptive power loss was considered as a source in the modeling of surge arrester based on finite element method. Adaptive network based fuzzy inference system and frequency dependent model were used to model power loss in low and high current regions, respectively. To obtain accurate power loss, which is very important factor in electro‐thermal analysis, applied voltage and temperature were considered as inputs in adaptive network based fuzzy inference system model. The experimental setup including impulse generator, power frequency high voltage generator and also an oven was arranged to achieve real data. Finally, the results of simulation based on proposed adaptive method were compared with the thermal infrared camera results. This study shows that the electro‐thermal behavior of surge arrester is predictable with a good accuracy by using artificial model. © 2015 Wiley Periodicals, Inc. Comput Appl Eng Educ 23:910–920, 2015; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21663
Expanding the Imine Reductase Toolbox by Exploring the Bacterial Protein‐Sequence Space
Authors: Wetzl Dennis , Berrera Marco , Sandon Nicolas , Fishlock Dan , Ebeling Martin , Müller Michael , Hanlon Steven , Wirz Beat , Iding Hans 
Published: June 2015

AbstractRecent investigations on imine reductases (IREDs) have enriched the toolbox of potential catalysts for accessing chiral amines, which are important building blocks for the pharmaceutical industry. Herein, we describe the characterization of 20 new IREDs. A C‐terminal domain clustering of the bacterial protein‐sequence space was performed to identify the novel IRED candidates. Each of the identified enzymes was characterized against a set of nine cyclic imine model substrates. A refined clustering towards putative active‐site residues was performed and was consistent both with our screening and previously reported results. Finally, preparative scale experiments on a 100 mg scale with two purified IREDs, IR_20 from Streptomyces tsukubaensis and IR_23 from Streptomyces vidiochromogenes, were carried out to provide (R)‐2‐methylpiperidine in 98 % ee (71 % yield) and (R)‐1‐methyl‐1,2,3,4‐tetrahydroisoquinoline in >98 % ee (82 % yield).
Synthesis of a Cytotoxic Amanitin for Biorthogonal Conjugation
Authors: Zhao Liang , May Jonathan P. , Blanc Antoine , Dietrich David J. , Loonchanta Anastak , Matinkhoo Kaveh , Pryyma Alla , Perrin David M. 
Published: June 2015

AbstractAlpha‐amanitin is an exceedingly toxic, naturally occurring, bicyclic octapeptide that inhibits RNA polymerase and results in cellular and organismal death. Here we report the straightforward synthesis of an amanitin analogue that exhibited near‐native toxicity. A pendant alkyne was readily installed to enable copper‐catalyzed alkyne–azide cycloaddition (CuAAC) to azido‐rhodamine and two azide‐bearing versions of the RGD peptide. The fluorescent toxin analogue entered cells and provoked morphological changes consistent with cell death. The latter two conjugates are as toxic as the parent alkyne precursor, which demonstrates that conjugation does not diminish toxicity. In addition, we showed that toxicity depends on a single diastereomer of the unnatural amino acid, dihydroxyisoleucine (DHIle), at position 3. The convenient synthesis of a heptapeptide precursor now provides access to bioactive amanitin analogues that may be readily conjugated to biomolecules of interest.
The mammalian target of rapamycin signaling pathway regulates myocyte enhancer factor‐2C phosphorylation levels through integrin‐linked kinase in goat skeletal muscle satellite cells
Authors: Wu Haiqing , Ren Yu , Pan Wei , Dong Zhenguo , Cang Ming , Liu Dongjun 
Published: June 2015

AbstractMammalian target of rapamycin (mTOR) signaling pathway plays a key role in muscle development and is involved in multiple intracellular signaling pathways. Myocyte enhancer factor‐2 (MEF2) regulates muscle cell proliferation and differentiation. However, how the mTOR signaling pathway regulates MEF2 activity remains unclear. We isolated goat skeletal muscle satellite cells (gSSCs) as model cells to explore mTOR signaling pathway regulation of MEF2C. We inhibited mTOR activity in gSSCs with PP242 and found that MEF2C phosphorylation was decreased and that muscle creatine kinase (MCK) expression was suppressed. Subsequently, we detected integrin‐linked kinase (ILK) using MEF2C coimmunoprecipitation; ILK and MEF2C were colocalized in the gSSCs. We found that inhibiting mTOR activity increased ILK phosphorylation levels and that inhibiting ILK activity with Cpd 22 and knocking down ILK with small interfering RNA increased MEF2C phosphorylation and MCK expression. In the presence of Cpd 22, mTOR activity inhibition did not affect MEF2C phosphorylation. Moreover, ILK dephosphorylated MEF2C in vitro. These results suggest that the mTOR signaling pathway regulates MEF2C positively and regulates ILK negatively and that ILK regulates MEF2C negatively. It appears that the mTOR signaling pathway regulates MEF2C through ILK, further regulating the expression of muscle‐related genes in gSSCs.
Two‐Step One‐Pot Synthesis of Pinoresinol from Eugenol in an Enzymatic Cascade
Authors: Ricklefs Esther , Girhard Marco , Koschorreck Katja , Smit Martha S. , Urlacher Vlada B. 
Published: June 2015

AbstractThe phytoestrogen pinoresinol is a high‐value compound that has a protective effect against diverse health disorders, and thus is of interest for the pharmaceutical industry. Isolation of pinoresinol from plants suffers from low yields, and its chemical synthesis involves several work‐up steps. In this study we devised a novel two‐step one‐pot enzymatic cascade combining a vanillyl‐alcohol oxidase and a laccase for the production of pinoresinol from eugenol via the intermediate coniferyl alcohol. Along with the well‐characterized vanillyl‐alcohol oxidase from Penicillium simplicissimum used to catalyze the oxidation of eugenol, enzyme screening revealed three bacterial laccases that were appropriate for the synthesis of pinoresinol from coniferyl alcohol. The cascade was optimized regarding enzyme ratios, pH value, and the presence of organic solvents. Under optimized conditions, pinoresinol concentration achieved 4.4 mM (1.6 g l−1), and this compound was isolated and analyzed.
Insights into the Oxidation State and Location of Rhenium in Re‐Pd/TiO2 Catalysts for Aqueous‐Phase Selective Hydrogenation of Succinic Acid to 1,4‐Butanediol as a Function of Palladium and Rhenium Deposition Methods
Authors: Ly Bao Khanh , Tapin Benoît , Aouine Mimoun , Delichere Pierre , Epron Florence , Pinel Catherine , Especel Catherine , Besson Michèle 
Published: June 2015

AbstractReOx‐Pd/TiO2 catalysts prepared from different 2 wt %Pd/TiO2 catalysts using two protocols for the deposition of the Re promoter (successive impregnation and catalytic reduction) were characterized by different techniques to better understand the nature of the active and selective sites implied in the aqueous‐phase hydrogenation of succinic acid to 1,4‐butanediol. Regardless of the support and Re introduction method, it was established that varying amounts of Pd and Re were in very close proximity without electronic interaction in the reduced catalysts. A high fraction of Re always remained partially oxidized to generate a bimetallic catalyst that can provide the necessary bifunctional sites to enable the selective hydrogenolysis of the intermediate γ‐butyrolactone to 1,4‐butanediol. Depending on the method of promotion, the ReOx species that interact with Pd were deposited as clusters with different spatial Re–Re interactions.
4‐CH3CONH–TEMPO/Peracetic Acid System for a Shortened Electron‐Transfer‐Cycle‐Controlled Oxidation of Secondary Alcohols
Authors: Zhang Shufang , Miao Chengxia , Xia Chungu , Sun Wei 
Published: June 2015

AbstractWe have developed a 2,2,6,6‐tetramethylpiperidine‐1‐oxyl (TEMPO) derivative catalyzed oxidation of secondary alcohols with peracetic acid as the oxidant, which was generated from H2O2 and acetic acid catalyzed by strongly acidic resins. The oxidation of alcohols proceeded well through a shortened electron‐transfer cycle under metal‐free conditions, avoiding the use of any other electron‐transfer mediators such as halides. In addition, we demonstrated that the present system exhibited excellent efficiency under mild conditions for the oxidation of aromatic, aliphatic, and allylic secondary alcohols.
Mapping the Interactions of I2, I., I−, and I+ with Alkynes and Their Roles in Iodocyclizations
Authors: Volpe Rohan , Aurelio Luigi , Gillin Murray G. , Krenske Elizabeth H. , Flynn Bernard L. 
Published: June 2015

AbstractA combination of experiment and theory has been used to explore the mechanisms by which molecular iodine (I2) and iodonium ions (I+) activate alkynes towards iodocyclization. Also included in the analysis are the roles of atomic iodine (I.) and iodide ion (I−) in mediating the competing addition of I2 to the alkyne. These studies show that I2 forms a bridged I2–alkyne complex, in which both alkyne carbons are activated towards nucleophilic attack, even for quite polarized alkynes. By contrast, I+ gives unsymmetrical, open iodovinyl cations, in which only one carbon is activated toward nucleophilic attack, especially for polarized alkynes. Addition of I2 to alkynes competes with iodocyclization, but is reversible. This fact, together with the capacity of I2 to activate both alkyne carbons towards nucleophilic attack, makes I2 the reagent of choice (superior to iodonium reagents) for iodocyclizations of resistant substrates. The differences in the nature of the activated intermediate formed with I2 versus I+ can also be exploited to accomplish reagent‐controlled 5‐exo/6‐endo‐divergent iodocyclizations.
Lewis Acid Catalyzed Condensation–Cyclization Cascade: Direct Synthesis of Di/Trifluoromethyl‐1,2,3,4‐tetrahydroquinazolines
Authors: Prakash G. K. Surya , Papp Attila , Munoz Socrates B. , May Nathan , Jones John‐Paul , Haiges Ralf , Esteves Pierre Mothé , Mathew Thomas 
Published: June 2015

AbstractCondensed heterocycles such as quinazolines constitute the framework of many promising drugs. The great impact of the dramatic fluorine effect in pharmaceuticals prompted a great surge in the quest for fluorinated drug design resulting in over 20 % fluorine‐containing drugs in the market today. Therefore, finding an efficient and cost‐effective method for the direct synthesis of fluorine‐tagged quinazoline systems is of great significance in the pharmaceutical arena. For the first time, a one‐pot sequential condensation–cyclization reaction to form selectively the difluoro/trifluoromethylated tetrahydroquinazolines from simple components difluoro/trifluoroacetaldehyde hemiacetal and aromatic amines is reported. Our recent studies using difluoro/trifluoroacetaldehyde hemiacetal as simple and elegant difluoro/trifluoromethyl synthons and metal triflates such as gallium triflate as safe and stable Lewis acid catalysts led us to this direct synthesis protocol for the expedient and convenient synthesis of fluorinated quinazolines. DFT calculations at PCM/B3LYP/6‐31++G** were carried out for evaluating a possible reaction mechanism for this cyclization. According to the DFT calculations, product stereochemistry is thermodynamically driven, favoring the cis isomer as the major product, which is also confirmed experimentally.
Direct Synthesis of Chiral 3‐Arylsuccinimides by Rhodium‐Catalyzed Enantioselective Conjugate Addition of Arylboronic Acids to Maleimides
Authors: Gopula Balraj , Yang Shu‐Han , Kuo Ting‐Shen , Hsieh Jen‐Chieh , Wu Ping‐Yu , Henschke Julian P. , Wu Hsyueh‐Liang 
Published: June 2015

AbstractChiral rhodium catalysts comprising 2,5‐diaryl‐ substituted bicyclo[2.2.1]diene ligands L1–L10 were utilized in the enantioselective 1,4‐addition reaction of arylboronic acids to N‐substituted maleimides. In the presence of 2.5 mol % of RhI/L2, enantioenriched conjugate addition adducts were isolated in 72–99 % yields with 86–98 % ee. This protocol offers a convenient method to access a variety of 3‐arylsuccinimides in a highly enantioselective manner. Maleimides with readily cleavable N‐protecting groups were tolerated enabling the synthesis of useful synthetic intermediates. Pyrrolidine 4, a biologically active compound, and pyrrolidine 5, an ent‐precursor to an HSD‐1 inhibitor, were synthesized to demonstrate the utility of this method.
A Series of Lanthanide Metal–Organic Frameworks with Interesting Adjustable Photoluminescence Constructed by Helical Chains
Authors: Liu Ying , Zhang Yu , Hu Gong Hao , Zhou Shuai , Fan Ruiqing , Yang Yulin , Xu Yan 
Published: June 2015

AbstractBased on the isonicotinic acid (HIN=pyridine‐4‐carboxylic acid), seven lanthanide metal–organic frameworks (MOFs) with the formula [Ln(IN)2L] (Ln=Eu (1), Tb (2), Er (3), Dy (4), Ho (5), Gd (6), La (7), L=OCH2CH2OH) have been synthesized by mixing Ln2O3 with HIN under solvothermal conditions, and characterized by single‐crystal X‐ray diffraction, powder X‐ray diffraction, infrared spectroscopy, and fluorescence spectroscopy. Crystal structural analysis shows that compounds 1–6 are isostructural, crystallize in a chiral space group P212121, whereas compound 7 crystallizes in space group C2/c. Nevertheless, they all consist of new intertwined chains. Simultaneously, on the basis of the above‐mentioned compounds, we have realized a rational design strategy to form the doped Ln MOFs [(EuxTb1−x)(IN)2L] (x=0.35 (8), x=0.19 (9), x=0.06 (10)) by utilizing TbIII as the second “rare‐earth metal”. Interestingly, the photoluminescence of [(EuxTb1−x)(IN)2L] are not only adjustable by the ratios of Eu/Tb, but also temperature or excitation wavelength.
The Effects of Stagnant Slabs on the Topography of 410 km Discontinuity Beneath the Pamir‐Hindu Kush Region
Authors: Yi SUI , Yuan‐Ze ZHOU , Xiao‐Ran WANG 
Published: June 2015

AbstractThe effects of stagnant slabs on the topography of the 410 km discontinuity is helpful in determining the composition of the Earth's interior and understanding the relevant geodynamical processes. The Pamir‐Hindu Kush region is a rare subduction area subject to intermediate and deep earthquakes whose waveforms can be used to map the topography of the 410 km discontinuity. Broadband/short period waveform data from six earthquakes in the subducted slabs beneath the Pamir‐Hindu Kush region recorded by the Hi‐net seismic network, Japan and one recorded by the TA seismic array, USA, were processed using the 4‐th root slant stack method. The focal depths of the earthquakes were between 154.0 and 220.9 km, and their body wave magnitudes were between Mb 5.6 and 6.4. The conversion SdP phases at the velocity interfaces were found from 36 vespegrams, and the conversion depths near the 410 km discontinuity were determined based on the IASP91 model. The 410 km discontinuity is uplifted to depths between 372 and 398 km. Compared with slabs in western Pacific subducting regions, the stagnant subducted slab causes a smaller impact on the topography of the 410 km discontinuity.
A Statistical Analysis of Solar Wind Parameters and Geomagnetic Indices during the Solar Cycle 23
Authors: Xiao‐Fei SHEN , Bin‐Bin NI , Xu‐Dong GU , Chen ZHOU , Yong LIU , Zheng XIANG , Zheng‐Yu ZHAO 
Published: June 2015

AbstractInterplanetary Coronal mass ejections (CMEs) and corotating interaction regions (CIRs) are two types of most geoeffective solar wind transients and also the main drivers of geomagnetic storms. In this study, by using a superposed epoch analysis, we have compared the statistical features of solar wind parameters for the two types of solar disturbances during the 23rd solar cycle and the resulting changes of geomagnetic indices (Dst, AE, and Kp). Meanwhile, the statistics of solar wind parameters and geomagnetic indices corresponding to magnetic storms with different intensities are also investigated. In general, it is found that the slopes of linearly fitted Nsw/Pdyn curves (where Nsw is the solar wind proton density and Pdyn is the solar wind dynamic pressure) with respect to epoch time remains positive for CME events but negative for CIR events, which can act as a feasible means to distinguish CME and CIR events. On average, compared to CIR events, CME events have larger magnitudes of southward IMF Bz, solar wind dynamic pressure, AE and Kp indices but smaller Dstmin. In principle, CMEs bear higher possibility to drive extremely intense (i.e., super) geomagnetic storms. The overall variations of Dst tend to be similar to some extent for different levels of geomagnetic storms, however, Dst decreases faster for stronger storms.
What is the optimal management of early‐stage low‐grade follicular lymphoma in the modern era?
Authors: Vargo John A. , Gill Beant S. , Balasubramani Goundappa K. , Beriwal Sushil 
Published: June 2015

BACKGROUNDDespite international practice guidelines endorsing radiotherapy (RT) as the preferred initial therapy, treatment approaches vary for patients with early‐stage follicular lymphoma. The authors engaged the National Cancer Data Base to analyze patterns of care and survival outcomes for patients with early‐stage follicular lymphoma in the era of modern therapy.METHODSA National Cancer Data Base retrospective cohort study was conducted of 35,961 patients with lymph node and extranodal, American Joint Committee on Cancer stage I to II, WHO grade 1 to 2 follicular lymphoma who were diagnosed between 1998 and 2012. Univariate and multivariable analyses were performed to identify sociodemographic, treatment, and tumor characteristics that were predictive of overall survival (OS) and treatment use. Propensity score‐adjusted Cox proportional hazards ratios for survival in patients treated for follicular lymphoma were used.RESULTSOf the 35,961 patients with follicular lymphoma included in the current study, 63% had stage I disease, 79% were without extranodal disease, and 61% were aged >60 years. RT use decreased from 37% in 1999 to 24% in 2012 (P<.0001), with corresponding significant increases in observation and single‐agent chemotherapy. Patients who received RT had 5‐year and 10‐year OS rates of 86% and 68%, respectively, compared with 74% and 54%, respectively, for those who did not receive RT (P<.0001). On multivariable survival analysis, including a propensity score to account for potential uncaptured confounding variables due to a lack of randomization, upfront RT remained independently associated with improved OS (hazard ratio of death, 0.54; 95% confidence interval, 0.47‐0.63 [P<.0001]).CONCLUSIONSRT is an increasingly underused treatment approach in the era of modern therapy for patients with early‐stage follicular lymphoma. The use of RT appears to improve OS and should remain standard practice as encouraged by clinical practice guidelines. Cancer 2015;121:3325–3334. © 2015 American Cancer Society.
Graphitic Carbon Nitride/Graphene Hybrids as New Active Materials for Energy Conversion and Storage
Authors: Zhao Yang , Zhang Jing , Qu Liangti 
Published: June 2015

AbstractEnergy conversion and storage devices play an important role in industry and society with the rapid growth of energy consumption. Developing a highly efficient, environmentally friendly device mainly depends on improvements in high‐performance electrode materials or catalysts. Recently, graphitic carbon nitride/graphene (g‐C3N4/graphene) hybrids have drawn considerable attention and shown great potential as active materials in the field of energy conversion and storage due to their unique and tunable nanostructure, high nitrogen content, and conductivity. This review focuses on the recent significant advances in the fabrication and application of g‐C3N4/graphene hybrids as electro‐ or photocatalysts and electrode materials. Synthetic strategies and applications for photo‐ or electro‐related devices are presented, accompanied with a discussion of the challenges and research directions for the future development of g‐C3N4/graphene hybrids.
Template‐Guided Ionic Self‐Assembled Molecular Materials and Thin Films with Nanoscopic Order
Authors: Santella Marco , Amini Fatima , Andreasen Kristian B. , Aswad Dunya S. , Ausar Helene , Austin Lillian Marie , Bora Ilkay , Boye Ida M. I. , Brinkenfeldt Nikolaj K. , Bøe Magnus F. , Cakmak Emine , Catovic Alen , Christensen Jonas M. , Dalgaard Jonas H. , Danielsen Helena Maria D. , Bouyahyaoui Abdel H. El , Dib Sarah E. H. El , Khaiyat Btihal El , Farooq Iqra , Fjellerup Freja K. , Frederiksen Gregers W. , Frederiksen Henriette R. S. , Gleerup David , Gold Mikkel , Gruber Morten F. , Gylling Mie , Heidari Vita , Herzberg Mikkel , Holgaard U. Laurens D. , Hundahl Adam C. , Hviid Rune , Høhling Julian S. , Abd Issa Fatima Z. , Jakobsen Nicklas R. , Jakobsen Rasmus K. , Jensen Benjamin L. , Jensen Phillip W. K. , Juelsholt Mikkel , Liao Zhiyu , Le Chung L. , Mayanja Ivan F. , Moustafa Hadeel , Møller Charlie B. B. , Nielsen Cecilie L. , Nielsen Marius R. J. E. H. , Nielsen Søren S.‐R. , Olsen Markus J. , Paludan Bandula D. , Prestholm Idunn , Qoqaj Iliriana , Riel Christina B. , Rostgaard Tobias V. , Saleh Nora , Schultz Hannibal M. , Standland Mark , Svenningsen Jens S. , Sørensen Rasmus Truels , Visby Jesper , Wolff‐Sneedorff Emilie L. , Zachariassen Malte Hee , Ziari Edmond A. , Sørensen Henning O. , Sørensen Thomas Just 
Published: June 2015

AbstractIonic self‐assembly (ISA) is a proven method that exploits non‐covalent interactions to generate supramolecular materials. Here, we have expanded the scope of this approach fabricating thin films with nanoscopic order maintained over centimeters. Cationic layers of benzalkonium surfactants form a lamellar template. The template is able to host layers of negatively charged polyaromatic functional units, here demonstrated with β‐naphthol‐derived azo‐dyes. We show that a variety of these functional building blocks can be incorporated in the lamellar template through ISA. Sixteen different materials were produced, characterized, and processed into thin films, with lamellar order perpendicular to the substrate. Thus, a design concept is demonstrated in which diverse functional motifs can be isolated and ordered in a 2D lattice between layers of alkyl chains in bulk and in thin films, in which the molecular order is maintained and aligned to the substrate.
Local Control Theory in Trajectory Surface Hopping Dynamics Applied to the Excited‐State Proton Transfer of 4‐Hydroxyacridine
Authors: Curchod Basile F. E. , Penfold Thomas J. , Rothlisberger Ursula , Tavernelli Ivano 
Published: June 2015

AbstractThe application of local control theory combined with nonadiabatic ab initio molecular dynamics to study the photoinduced intramolecular proton transfer reaction in 4‐hydroxyacridine was investigated. All calculations were performed within the framework of linear‐response time‐dependent density functional theory. The computed pulses revealed important information about the underlying excited‐state nuclear dynamics highlighting the involvement of collective vibrational modes that would normally be neglected in a study performed on model systems constrained to a subset of the full configuration space. This study emphasizes the strengths of local control theory for the design of pulses that can trigger chemical reactions associated with the population of a given molecular excited state. In addition, analysis of the generated pulses can help to shed new light on the photophysics and photochemistry of complex molecular systems.