bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ionospheric delay gradient monitoring for GBAS by GPS stations near Suvarnabhumi airport, Thailand
Authors: Rungraengwajiake Sarawoot , Supnithi Pornchai , Saito Susumu , Siansawasdi Nattapong , Saekow Apitep 
Published: September 2015

AbstractGround‐based augmentation system (GBAS) is an important augmentation system that provides the differential corrections and integrity information from the reference stations to the aircrafts for precision approach and landing. It is known that the nonuniform ionospheric characteristics called “ionospheric delay gradient” can cause the errors in differential corrections degrading the accuracy and safety level if they are undetected by the reference stations. Since the characteristics of the ionosphere are different for each region, the ionospheric delay gradient observations in equatorial and low‐latitude regions are necessary for developing the suitable ionospheric threat models. The purpose of this work is to analyze the ionospheric delay gradients observed by three GPS stations near Suvarnabhumi airport in Bangkok, Thailand, which is located in the low‐latitude region. The ionospheric irregularities in this region are mainly caused by the plasma bubble, which usually occurs after sunset. The GPS data with plasma bubble occurrence during the September equinox 2011 and 2012 are therefore analyzed. In addition, the data analysis procedure utilizing the rate of total electron content change index for this region is proposed. The results show that the ionospheric delay gradients observed in the west‐east direction appear higher than the south‐north direction, varying from 28 to 178 mm/km during plasma bubble occurrences.
Hydrogen Self‐Sufficient Arene Reduction to Cyclohexane Derivatives Using a Combination of Platinum on Carbon and 2‐Propanol
Authors: Sawama Yoshinari , Mori Misato , Yamada Tsuyoshi , Monguchi Yasunari , Sajiki Hironao 
Published: September 2015

AbstractVarious arenes have been hydrogenated using platinum on carbon in a 2‐propanol‐aqueous mixed solvent at 100 °C without the addition of flammable hydrogen gas to give the corresponding cyclohexane derivatives. 2‐Propanol plays a role as an efficient hydrogen source based on the platinum on carbon‐catalyzed dehydrogenation.magnified image
Palladium‐Catalyzed One‐Pot Consecutive Amination and Sonogashira Coupling for Selective Synthesis of 2‐Alkynylanilines
Authors: Pan Shanfei , Ma Xueji , Zhong Danni , Chen Wanzhi , Liu Miaochang , Wu Huayue 
Published: September 2015

AbstractAn efficient catalytic approach to the synthesis of N,N‐dialkyl‐2‐alkynylanilines was developed by using Pd‐catalyzed norbornene‐mediated three‐component reactions of haloarenes, alkoxyamines (RO‐NR2), and alkynes. The procedure forms one CN bond and one CC bond efficiently in a one‐pot manner from readily available starting materials. A number of 2‐alkynylanilines with a broad range of functional groups were afforded in good to excellent yields.magnified image
Improvements and Applications of the Transition Metal‐Free Asymmetric Allylic Alkylation using Grignard Reagents and Magnesium Alanates
Authors: Grassi David , Alexakis Alexandre 
Published: September 2015

AbstractTwo new N‐heterocyclic carbene (NHC) ligands have been synthesized and employed in the transition metal‐free asymmetric allylic alkylation (AAA) mediated by Grignard reagents and magnesium alanates. The employment of these ligands showed high yields and improved regio‐ and enantioselectivity in the formation of tertiary and quaternary stereocenters. Moreover, the low catalyst loading (up to 0.3 mol%) and high scalability (up to 10 mmol) of this improved methodology provide a convenient access to biologically active compounds and synthetically valuable intermediates.magnified image
Catalytic Asymmetric 1,6‐Conjugate Addition of para‐Quinone Methides: Formation of All‐Carbon Quaternary Stereocenters
Authors: Wang Zhaobin , Wong Yuk Fai , Sun Jianwei 
Published: September 2015

AbstractDescribed herein is a general and mild catalytic asymmetric 1,6‐conjugate addition of para‐quinone methides (p‐QMs), a class of challenging reactions with previous limited success. Benefiting from chiral Brønsted acid catalysis, which allows in situ formation of p‐QMs, our reaction expands the scope to general p‐QMs with various substitution patterns. It also enables efficient intermolecular formation of all‐carbon quaternary stereocenters with high enantioselectivity.
Enantiomerically Pure Tribenzotriquinacenes through Stereoselective Synthesis
Authors: Greschner Wilko , Neumann Beate , Stammler Hans‐Georg , Gröger Harald , Kuck Dietmar 
Published: September 2015

AbstractInherently chiral acetophenones and benzaldehydes bearing the large, bowl‐shaped framework of tribenzotriquinacene (TBTQ) were synthesized in enantiomerically pure form employing enzyme catalysis. Five‐step sequences involving lipase CAL‐B lead to the (M)‐enantiomers, (+)‐2‐acetyl‐TBTQ (M)‐5 and (+)‐2‐formyl‐TBTQ (M)‐6, whereas use of lipase PS leads to the (P)‐enantiomers, (−)‐2‐acetyl‐TBTQ (P)‐5 and (−)‐2‐formyl‐TBTQ (P)‐6, with at least 99 % ee in each case. The absolute configuration of these rigid 3D building blocks was determined by X‐ray diffraction analysis of the ketones 5 and by comparison of their chiroptical properties with those of the aldehydes 6.
Valve Position‐based Control at Engine Key‐on of an Electro‐mechanical Valve Actuator for Camless Engines: A Robust Controller Tuning Via Bifurcation Analysis
Authors: Hoyos Velasco Carlos I. , di Gaeta Alessandro 
Published: September 2015

AbstractElectro‐mechanical valve actuators (EMVA) formed by two opposed electromagnets and two balanced springs are appealing solutions to implement advanced combustion concepts for camless engines. A crucial control problem for this valve actuator regards the first valve lift manoeuvre (termed 'first catching') to be rapidly performed after each insertion of the engine ignition key, when the EMVA rests at middle position where electromagnets offer low control authority. The control problem is challenging due to system nonlinear behavior. Mathematically, the EMVA system can be assumed to be a spring‐mass impacting system affected by a non‐smooth friction force and a dynamic saturated magnetic force. In this work an effective valve position‐based first catching control strategy is proposed to control the strongly nonlinear system. Bifurcation analysis and parameter space simulations are used to study the closed‐loop system behavior and to tune the controller gains as well. The effectiveness of the control approach is validated through numerical simulations of a highly predictive dynamic model of the valve actuator developed by authors in a previous work.
Analysis of General Ideal Proportional Navigation Guidance Laws
Authors: Tyan Feng 
Published: September 2015

AbstractIn this work, the capture region of the general ideal proportional navigation guidance law is analyzed with the following constraints: (i) the target's input acceleration is subject to independent or magnitude saturation, and (ii) the missile's input acceleration is subject to magnitude saturation. In addition to the case of unbounded maneuverability of missile with or without knowing the target acceleration, the necessary and sufficient condition for a bounded maneuvering missile that captures a nonmaneuvering target is also derived. Furthermore, the conditions that result in zero impact velocity are discovered and discussed in some of the cases. The capture regions that cannot be obtained analytically are determined numerically by a powerful classifier, the least square support vector machines. To have the capture region ready for least square support vector machines, all the state variables are transformed into modified polar variables and non‐dimensionalized to reduce the number of independent variables. In order to make the implementation possible in real time, an approximation of the Gaussian radial basis function is adopted to obtain the corresponding nonlinear feature mapping function. Through numerous numerical experiments, the proposed technique is found to be adequate for storing the capture region in an onboard fire control computer.
Postsynthetic modification of peptoids via the Suzuki‐Miyaura cross‐coupling reaction
Authors: Nam Ho Yeon , Seo Jiwon 
Published: September 2015

ABSTRACTWe developed a new method for modifying the side chains of peptoids on a solid phase resin, employing the palladium‐catalyzed Suzuki‐Miyaura cross‐coupling reaction. Optimized conditions using Pd(PPh3)4 and K2CO3 in the presence of Buchwald's SPhos ligand provided a high conversion in the coupling reaction. The usefulness of this method was demonstrated by synthesis of a two pyrene‐conjugated peptoid helix, which exhibited an interesting excimer formation. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 82–88, 2016.
Speech intelligibility in Parkinson's disease patients with zona incerta deep brain stimulation
Authors: Sandström Linda , Hägglund Patricia , Johansson Louise , Blomstedt Patric , Karlsson Fredrik 
Published: September 2015

AbstractObjectivesTo investigate the effects of l‐dopa (Levodopa) and cZi‐DBS (deep brain stimulation in caudal zona incerta) on spontaneous speech intelligibility in patients with PD (Parkinson's disease).Materials and MethodsSpontaneous utterances were extracted from anechoic recordings from 11 patients with PD preoperatively (off and on l‐dopa medication) and 6 and 12 months post bilateral cZi‐DBS operation (off and on stimulation, with simultaneous l‐dopa medication). Background noise with an amplitude corresponding to a clinical setting was added to the recordings. Intelligibility was assessed through a transcription task performed by 41 listeners in a randomized and blinded procedure.ResultsA group‐level worsening in spontaneous speech intelligibility was observed on cZi stimulation compared to off 6 months postoperatively (8 adverse, 1 positive, 2 no change). Twelve months postoperatively, adverse effects of cZi‐DBS were not frequently observed (2 positive, 3 adverse, 6 no change). l‐dopa administered preoperatively as part of the evaluation for DBS operation provided the overall best treatment outcome (1 adverse, 4 positive, 6 no change).ConclusionscZi‐DBS was shown to have smaller negative effects when evaluated from spontaneous speech compared to speech effects reported previously. The previously reported reduction in word‐level intelligibility 12 months postoperatively was not transferred to spontaneous speech for most patients. Reduced intelligibility due to cZi stimulation was much more prominent 6 months postoperatively than at 12 months.
A Bifunctional Nano‐Electrocatalyst Based on a Flower‐like Gold/Palladium Bimetallic Alloy Nanostructure and Its Graphene Hybrid
Authors: Sahu Subash Chandra , Satpati Biswarup , Besra Laxmidhar , Jena Bikash Kumar 
Published: September 2015

AbstractThis work demonstrates the one‐pot, seed‐free synthesis of unique flower‐like Au/Pd alloy nanostructures and their self‐assembly on a graphene support in an aqueous medium. The as‐prepared nanostructures were characterized thoroughly by TEM, UV/Vis spectrophotometry, XRD, and X‐ray photoelectron spectroscopy (XPS). The bifunctional electrocatalytic activity towards the oxidation of methanol and reduction of oxygen was investigated thoroughly. The results reveal that the Au/Pd alloy nanostructures show a composition‐dependent electrochemical activity. The Au/Pd alloy nanostructure with a flower‐like morphology shows superior electrocatalytic activity compared to its monometallic Pd counterpart and a commercially available Pd/C. Furthermore, the graphene support tunes the electrocatalytic performance of the Au/Pd alloy nanoflowers and substantiates their promising energy‐conversion applications for use in fuel cells.
Silica‐Grafted SnIV Catalysts in Hydrogen‐Transfer Reactions
Authors: Conrad Sabrina , Verel René , Hammond Ceri , Wolf Patrick , Göltl Florian , Hermans Ive 
Published: September 2015

AbstractThe front cover artwork for Issue 20/2015 is provided by the Hermans research group at the University of Wisconsin‐Madison (formerly located at the Swiss Federal Institute of Technology, Zurich). The image shows silica‐supported Lewis acidic SnIV sites that are tuned to be catalytically active in the Meerwein–Ponndorf–Verley reduction of cyclohexanone with 2‐butanol. See the Full Paper itself at http://dx.doi.org/10.1002/cctc.201500630.
Combination of Glycosyltransferases and a Glycosynthase in Sequential and One‐Pot Reactions for the Synthesis of Type 1 and Type 2 N‐Acetyllactosamine Oligomers
Authors: Henze Manja , Schmidtke Simon , Hoffmann Natalie , Steffens Hanna , Pietruszka Jörg , Elling Lothar 
Published: September 2015

AbstractThe front cover artwork for Issue 19/2015 is provided by the groups of Prof. Lothar Elling and Prof. Jörg Pietruszka (RWTH Aachen University and Heinrich‐Heine‐Universität Düsseldorf, respectively). The image shows the combination (“juggling”) of two glycosyltransferases (blue and red protein structures) and a galactosynthase (yellow protein structure) for the synthesis of a glycan library. See the Full Paper itself at http://dx.doi.org/10.1002/cctc.201500645.
State of Supported Nickel Nanoparticles during Catalysis in Aqueous Media
Authors: Chase Zizwe A. , Kasakov Stanislav , Shi Hui , Vjunov Aleksei , Fulton John L. , Camaioni Donald M. , Balasubramanian Mahalingam , Zhao Chen , Wang Yong , Lercher Johannes A. 
Published: September 2015

AbstractThe state of Ni supported on HZSM‐5 zeolite, silica, and sulfonated carbon was studied during aqueous‐phase catalysis of phenol hydrodeoxygenation using in situ extended X‐ray absorption fine structure spectroscopy. On sulfonated carbon and HZSM‐5 supports, NiO and Ni(OH)2 were readily reduced to Ni0 under reaction conditions (≈35 bar H2 in aqueous phenol solutions containing up to 0.5 wt. % phosphoric acid at 473 K). In contrast, Ni supported on SiO2 was not stable in a fully reduced Ni0 state. Water enables the formation of NiII phyllosilicate, which is more stable, that is, difficult to reduce, than either α‐Ni(OH)2 or NiO. Leaching of Ni from the supports was not observed over a broad range of reaction conditions. Ni0 particles on HZSM‐5 were stable even in presence of 15 wt. % acetic acid at 473 K and 35 bar H2.
One‐Pot Synthesis of Hydrophobically Modified Iminosugar C‐Alkynylglycosides: Facile Synthesis of Polyhydroxy Tetrahydroindolizines
Authors: Senthilkumar Soundararasu , Prasad Sure Siva , Das Amrita , Baskaran Sundarababu 
Published: September 2015

AbstractA mild and efficient one‐pot method has been developed for the stereoselective synthesis of structurally diverse novel iminosugar C‐alkynylglycosides. The generality of this methodology has been demonstrated with a wide variety of amines and copper acetylides. This one‐pot method has been exploited in the synthesis of new class of DNA cross‐linking agents, polyhydroxy 1‐vinyl‐tetrahydroindolizine derivatives.
Cooperative Catalysis: Calcium and Camphorsulfonic Acid Catalyzed Cycloisomerization of Diynols
Authors: Rauser Marian , Schroeder Sebastian , Niggemann Meike 
Published: September 2015

AbstractThe first transition metal‐free cycloisomerization of easily accessible diynols is presented as a novel approach to bicyclic 2H‐pyrans. As a one‐step protocol, the reaction proceeds in a single reaction cascade by intertwining mechanistic fragments borrowed from transition metal‐catalyzed Claisen rearrangment of vinyl ethers with our own work on allenyl/propargyl cation rearrangements and a 6π‐oxo‐electrocylization. It is enabled by a new cooperative catalytic system that combines a simple Ca2+ catalyst with camphorsulfonic acid.
The use of simultaneous confidence bands for comparison of single parameter fluorescent intensity data
Authors: Kim Dongha , Donnenberg Vera S. , Wilson John W. , Donnenberg Albert D. 
Published: September 2015

AbstractDespite the utility of multiparameter flow cytometry for a wide variety of biological applications, comparing single parameter histograms of fluorescence intensity remains a mainstay of flow cytometric analysis. Even comparisons requiring multiparameter gating strategies often end with single parameter histograms as the final readout. When histograms overlap, analysis relies on comparison of mean or median fluorescence intensities, or determination of percent positive based on an arbitrary cutoff. Earlier attempts to address this problem utilized either simple channel‐by‐channel subtraction without statistical evaluation, or the Kolmogorov‐Smirnov (KS) or Chi‐square test statistics, both of which proved to be overly sensitive to small and biologically insignificant differences. Here we present a method for the comparison of two single‐parameter histograms based on difference curves and their simultaneous confidence bands generated by bootstrapping raw channel data. Bootstrapping is a nonparametric statistical approach that can be used to generate confidence intervals without distributional assumptions about the data. We have constructed simultaneous confidence bands and show them to be superior to KS and Cox methods. The method constructs 95% confidence bands about the difference curves, provides aPvalue for the comparison and calculates the area under the difference curve (AUC) as an estimate of percent positive and the area under the confidence band (AUCSCB95), providing a lower estimate of the percent positive. To demonstrate the utility of this new approach we have examined single‐color fluorescence intensity data taken from a cell surface proteomic survey of a lung cancer cell line (A549) and a published fluorescence intensity data from a rhodamine efflux assay ofP‐glycoprotein activity, comparing rhodamine 123 loading and efflux in CD4 and CD8 T‐cell populations. SAS source code is provided as supplementary material. © 2015 International Society for Advancement of Cytometry
Use of acute and chronic ecotoxicity data in environmental risk assessment of pharmaceuticals
Authors: Vestel Jessica , Caldwell Daniel J. , Constantine Lisa , D'Aco Vincent J. , Davidson Todd , Dolan David G. , Millard Steven P. , Murray-Smith Richard , Parke Neil J. , Ryan Jim J. , Straub Jürg Oliver , Wilson Peter 
Published: September 2015

Abstract

For many older pharmaceuticals, chronic aquatic toxicity data are limited. To assess risk during development, scale-up, and manufacturing processes, acute data and physicochemical properties need to be leveraged to reduce potential long-term impacts to the environment. Aquatic toxicity data were pooled from daphnid, fish, and algae studies for 102 active pharmaceutical ingredients (APIs) to evaluate the relationship between predicted no-effect concentrations (PNECs) derived from acute and chronic tests. The relationships between acute and chronic aquatic toxicity and the n-octanol/water distribution coefficient (DOW) were also characterized. Statistically significant but weak correlations were observed between toxicity and log DOW, indicating that DOW is not the only contributor to toxicity. Both acute and chronic PNEC values could be calculated for 60 of the 102 APIs. For most compounds, PNECs derived from acute data were lower than PNECs derived from chronic data, with the exception of steroid estrogens. Seven percent of the PNECs derived from acute data were below the European Union action limit of 0.01 μg/L and all were anti-infectives affecting algal species. Eight percent of available PNECs derived from chronic data were below the European Union action limit, and fish were the most sensitive species for all but 1 API. These analyses suggest that the use of acute data may be acceptable if chronic data are unavailable, unless specific mode of action concerns suggest otherwise. Environ Toxicol Chem 2016;35:1201–1212. © 2015 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC.
Factors influencing the calculation of periodic secondary circulation in a tidal river: numerical modelling of the lower Sacramento River, USA
Authors: Bever Aaron J. , MacWilliams Michael L. 
Published: September 2015

AbstractSecondary circulation is the component of three‐dimensional (3D) flow in river channels perpendicular to the primary flow direction. Secondary circulation calculated from acoustic Doppler current profiler (ADCP) transects is sensitive to the calculation method and is affected by the transect angle relative to the mean flow direction and variations in the flow direction along a transect. To quantify bounds on transect alignment relative to river flow for field data collection and examine tidal time‐scale variability in secondary circulation, the 3D hydrodynamic model UnTRIM was applied to simulate the hydrodynamics in the lower reach of the Sacramento River (CA, USA). Secondary circulation was calculated using the Rozovskii and the zero net discharge methods on repeated transects extracted from the model results in regions of both relatively uniform and complex flows. When the depth‐averaged flow direction along a transect varied by more than about 5 °, occurring when the transect was as little as 10 to 20 ° out of normal to the mean flow direction, the Rozovskii method produced more realistic secondary circulation than the zero net discharge method. Analysis indicated that ADCP transects should be within 20 ° of perpendicular to the mean flow direction when calculating secondary circulation. Secondary circulation strength around two tidally influenced bends generally increased with increasing flow and broke down near slack water. However, the strength of the secondary circulation was not only a function of the flow magnitude, but also depended on the direction of the water flow and the transect location relative to the river curvature, which varied with the tidal flow direction. Copyright © 2015 John Wiley & Sons, Ltd.
Functional profile of S100A4‐deficient T cells
Authors: Weatherly Kathleen , Bettonville Marie , Torres David , Kohler Arnaud , Goriely Stanislas , Braun Michel Y. 
Published: September 2015

AbstractThe protein S100A4 is best known for its significant role in promoting motility and invasive capacity of cancer cells. Since S100A4 expression has been reported also in T cells, we analyzed its potential role in T cell motility and inflammation. Using S100a4+/Gfp mice, we show here that S100A4 is exclusively expressed by memory T cells of CD4+ or CD8+ subpopulations, predominantly of the effector memory T cell subtype. However, the protein was not required for in vitro memory T cell migration toward gradients of the inflammatory chemokine CXCL10. Moreover, T cell memory response was normal in S100A4‐deficient mice and lack of S100a4 gene expression did not induce any defect in promoting the development of protective immunity or inflammatory reactions leading to autoimmunity. Taken together, our results demonstrate that S100A4 activity is dispensable for T cell motility/migration and inflammatory potential.
Oxidation and other property changes of a remelted highly crosslinked UHMWPE in retrieved tibial bearings
Authors: Reinitz Steven D. , Currier Barbara H. , Levine Rayna A.C. , Collier John P. , Van Citters Douglas W. 
Published: September 2015

AbstractThis study examined retrieved UHMWPE tibial bearings made from a remelted highly crosslinked (HXL) UHMWPE to determine whether the material is chemically stable in vivo. Retrieved tibial components were measured for changes in ketone oxidation and crosslink density. Oxidation increased with in vivo duration, and a significant decrease in crosslink density with increased mean ketone oxidation index was observed. These results suggest that in vivo oxidation is causing material degradation. Furthermore, a subsurface whitened damage region was found below the articular surface of one bearing, indicating the possibility of a clinically relevant decrease in mechanical properties of this component. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 39–45, 2017.