bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbon isotope systematics of Turrialba volcano, Costa Rica, using a portable cavity ring‐down spectrometer
Authors: Malowany K. S. , Stix J. , de Moor J. M. , Chu K. , Lacrampe‐Couloume G. , Sherwood Lollar B.
Published: July 2017

Over the past two decades, activity at Turrialba volcano, Costa Rica, has shifted from hydrothermal to increasingly magmatic in character, with enhanced degassing and eruption potential. We have conducted a survey of the δ13C signatures of gases at Turrialba using a portable field‐based CRDS with comparison to standard IRMS techniques. Our δ13C results of the volcanic plume, high‐temperature vents, and soil gases reveal isotopic heterogeneity in the CO2 gas composition at Turrialba prior to its recent phase of eruptive activity. The isotopic value of the regional fault system, Falla Ariete (–3.4 ± 0.1‰), is in distinct contrast with the Central crater gases (–3.9 ± 0.1‰) and the 2012 high‐temperature vent (–4.4 ± 0.2‰), an indication that spatial variability in δ13C may be linked to hydrothermal transport of volcanic gases, heterogeneities in the source composition, or magmatic degassing. Isotopic values of CO2 samples collected in the plume vary from δ13C of −5.2 to −10.0‰, indicative of mixing between atmospheric CO2 (–9.2 ± 0.1‰), and a volcanic source. We compare the Keeling method to a traditional mixing model (hyperbolic mixing curve) to estimate the volcanic source composition at Turrialba from the plume measurements. The predicted source compositions from the Keeling and hyperbolic methods (–3.0 ± 0.5‰ and −3.9 ± 0.4‰, respectively) illustrate two potential interpretations of the volcanic source at Turrialba. As of the 29 October 2014, Turrialba has entered a new eruptive period, and continued monitoring of the summit gases for δ13C should be conducted to better understand the dominant processes controlling δ13C fractionation at Turrialba.
Reconciling magma‐ocean crystallization models with the present‐day structure of the Earth's mantle
Authors: Ballmer Maxim D. , Lourenço Diogo L. , Hirose Kei , Caracas Razvan , Nomura Ryuichi
Published: July 2017

Terrestrial planets are thought to experience episode(s) of large‐scale melting early in their history. Fractionation during magma‐ocean freezing leads to unstable stratification within the related cumulate layers due to progressive iron enrichment upward, but the effects of incremental cumulate overturns during MO crystallization remain to be explored. Here, we use geodynamic models with a moving‐boundary approach to study convection and mixing within the growing cumulate layer, and thereafter within the fully crystallized mantle. For fractional crystallization, cumulates are efficiently stirred due to subsequent incremental overturns, except for strongly iron‐enriched late‐stage cumulates, which persist as a stably stratified layer at the base of the mantle for billions of years. Less extreme crystallization scenarios can lead to somewhat more subtle stratification. In any case, the long‐term preservation of at least a thin layer of extremely enriched cumulates with Fe# > 0.4, as predicted by all our models, is inconsistent with seismic constraints. Based on scaling relationships, however, we infer that final‐stage Fe‐rich magma‐ocean cumulates originally formed near the surface should have overturned as small diapirs, and hence undergone melting and reaction with the host rock during sinking. The resulting moderately iron‐enriched metasomatized/hybrid rock assemblages should have accumulated at the base of the mantle, potentially fed an intermittent basal magma ocean, and be preserved through the present‐day. Such moderately iron‐enriched rock assemblages can reconcile the physical properties of the large low shear‐wave velocity provinces in the present‐day lower mantle. Thus, we reveal Hadean melting and rock‐reaction processes by integrating magma‐ocean crystallization models with the seismic‐tomography snapshot.
Tree‐based flood damage modeling of companies: Damage processes and model performance
Authors: Sieg Tobias , Vogel Kristin , Merz Bruno , Kreibich Heidi
Published: July 2017

Reliable flood risk analyses, including the estimation of damage, are an important prerequisite for efficient risk management. However, not much is known about flood damage processes affecting companies. Thus, we conduct a flood damage assessment of companies in Germany with regard to two aspects. First, we identify relevant damage‐influencing variables. Second, we assess the prediction performance of the developed damage models with respect to the gain by using an increasing amount of training data and a sector‐specific evaluation of the data. Random forests are trained with data from two postevent surveys after flood events occurring in the years 2002 and 2013. For a sector‐specific consideration, the data set is split into four subsets corresponding to the manufacturing, commercial, financial, and service sectors. Further, separate models are derived for three different company assets: buildings, equipment, and goods and stock. Calculated variable importance values reveal different variable sets relevant for the damage estimation, indicating significant differences in the damage process for various company sectors and assets. With an increasing number of data used to build the models, prediction errors decrease. Yet the effect is rather small and seems to saturate for a data set size of several hundred observations. In contrast, the prediction improvement achieved by a sector‐specific consideration is more distinct, especially for damage to equipment and goods and stock. Consequently, sector‐specific data acquisition and a consideration of sector‐specific company characteristics in future flood damage assessments is expected to improve the model performance more than a mere increase in data.
Simultaneous XEDS‐EBSD Study of NiCoAlFeCu(Cr,Ti) Multi‐Component Alloys
Authors: Cruz‐Gandarilla Francisco , Coreño‐Alonso Oscar , Cabañas–Moreno José Gerardo , Chan Lisa H. , Gómez‐Esparza Cynthia , Martínez Sánchez Roberto
Published: July 2017

NiCoAlFeCu, NiCoAlFeCuCr, and NiCoAlFeCuCrTi high‐entropy alloys are prepared by mechanical alloying and sintered at 1200 °C and a pressure of 1.5 GPa for 3 h. The alloys were characterized by X‐ray diffraction (XRD), electron backscatter diffraction (EBSD), and X‐ray energy dispersive spectrometry (XEDS). The phases found are mostly variants of the face centered cubic (fcc) phases (space group ), bcc (space group ), and hexagonal (space group P63/mmc). Adding Ti to the NiCoAlFeCuCr system has strong effects on the solubility of the elements in the different phases and increases dramatically the number of phases present. The use of EBSD and XEDS allowed identification of a cubic phase in NiCoAlFeCu samples, which cannot be identified by XRD alone, and confirmed its identification by XRD in NiCoAlFeCuCr samples. The spatial distribution of phases and the grain structure in the three different samples, measured by EBSD and XEDS, is reported.
Low Resistive Edge Contacts to CVD‐Grown Graphene Using a CMOS Compatible Metal
Authors: Shaygan Mehrdad , Otto Martin , Sagade Abhay A. , Chavarin Carlos A. , Bacher Gerd , Mertin Wolfgang , Neumaier Daniel
Published: July 2017

The exploitation of the excellent intrinsic electronic properties of graphene for device applications is hampered by a large contact resistance between the metal and graphene. The formation of edge contacts rather than top contacts is one of the most promising solutions for realizing low ohmic contacts. In this paper the fabrication and characterization of edge contacts to large area CVD‐grown monolayer graphene by means of optical lithography using CMOS compatible metals, i.e. Nickel and Aluminum is reported. Extraction of the contact resistance by Transfer Line Method (TLM) as well as the direct measurement using Kelvin Probe Force Microscopy demonstrates a very low width specific contact resistance down to 130 Ωμm. The contact resistance is found to be stable for annealing temperatures up to 150°C enabling further device processing. Using this contact scheme for edge contacts, a field effect transistor based on CVD graphene with a high transconductance of 0.63 mS/μm at 1 V bias voltage is fabricated.
Recent progress in many‐body localization
Authors: Abanin Dmitry A. , Papić Zlatko
Published: July 2017

This article is a brief introduction to the rapidly evolving field of many‐body localization. Rather than giving an in‐depth review of the subject, our aspiration here is simply to introduce the problem and its general context, outlining a few directions where notable progress has been achieved in recent years. We hope that this will prepare the readers for the more specialized articles appearing in this dedicated Volume of Annalen der Physik, where these developments are discussed in more detail.

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Molecular Magnetic Resonance Imaging of Lung Fibrogenesis with an Oxyamine‐Based Probe
Authors: Waghorn Philip A. , Jones Chloe M. , Rotile Nicholas J. , Koerner Steffi K. , Ferreira Diego S. , Chen Howard H. , Probst Clemens K. , Tager Andrew M. , Caravan Peter
Published: July 2017

Fibrogenesis is the active production of extracellular matrix in response to tissue injury. In many chronic diseases persistent fibrogenesis results in the accumulation of scar tissue, which can lead to organ failure and death. However, no non‐invasive technique exists to assess this key biological process. All tissue fibrogenesis results in the formation of allysine, which enables collagen cross‐linking and leads to tissue stiffening and scar formation. We report herein a novel allysine‐binding gadolinium chelate (GdOA), that can non‐invasively detect and quantify the extent of fibrogenesis using magnetic resonance imaging (MRI). We demonstrate that GdOA signal enhancement correlates with the extent of the disease and is sensitive to a therapeutic response.
Polymerization of graphene oxide nanosheet by using of aminoclay: Electrocatalytic activity of its platinum nanohybrids
Authors: Hoseini S. Jafar , Bahrami Mehrangiz , Maddahfar Mahnaz , Hashemi Fath Roghayeh , Roushani Mahmoud
Published: July 2017

This study describes the polymerization of graphene oxide (GO) nanosheet to reduced‐GO‐aminoclay (RGC) by covalent functionalization of chemically reactive epoxy groups on the basal planes of GO with amine groups of magnesium phyllosilicate clay (known as aminoclay). The resulting RGC sheets were characterized and applied to support platinum nanostructures at toluene/water interface. Pt nanoparticles (NPs) with diameters about several nanometers were adhered to RGC sheets by chemical reduction of [PtCl2(cod)] (cod = cis,cis‐1,5‐cyclooctadiene) complex. Catalytic activity of Pt NPs thin films were investigated in the methanol oxidation reaction. Cyclic voltammetry results exhibit that the Pt/reduced‐GO (RGO) and Pt/RGC thin films showed improved catalytic activity in methanol oxidation reaction in comparison to other Pt NPs thin films, demonstrating that the prepared Pt/RGO and Pt/RGC thin films are promising catalysts for direct methanol fuel cell.
Equisetum arvense As an abundant source of silica nanoparticles. SiO2/H3PW12O40 nanohybrid material as an efficient and environmental benign catalyst in the synthesis of 2‐amino‐4H‐chromenes under solvent‐free conditions
Authors: Tayebee Reza , Pejhan Akbar , Ramshini Hassan , Maleki Behrooz , Erfaninia Nasrin , Tabatabaie Zohre , Esmaeili Effat
Published: July 2017

Uniform SiO2 nanoparticles were successfully prepared from Equisetum arvense obtained from the north‐east of Iran. Then, surface modification of the extracted nanoparticles was performed with a methanol solution of H3PW12O40 via wet impregnation method. The prepared nanocatalyst was characterized by XRD, FESEM, ICP, UV–Vis, and FT‐IR spectroscopy. The supported heterogeneous nanocatalyst was successfully applied as a Lewis/Bronsted acid catalyst in the synthesis of a series of substituted 4H–chromenes via condensation of aromatic aldehydes, malononitrile, and 4‐hydroxycoumarin under solventless conditions with fine yields in appropriately short times.
N‐(3‐silyl propyl) diethylene triamine N,N',N''‐tri‐sulfonic acid immobilized on Fe3‐xTixO4 magnetic nanoparticles: A new recyclable heterogeneous nanocatalyst for the synthesis of hexahydroquinolines
Authors: Azarifar Davood , Abbasi Younes , Badalkhani Omolbanin
Published: July 2017

In the present study, for the first time N‐(3‐silyl propyl) diethylene triamine N,N',N''‐tri‐sulfonic acid (SPDETATSA) was grafted on magnetic Fe3‐xTixO4 nanoparticles. The structure of the resulted nanoparticles was characterized based on Fourier‐transform infrared (FT‐IR), energy‐dispersive X‐ray spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), and vibrating sample magnetometer (VSM) analyses. The results confirmed the successful immobilization of sulfamic acid groups onto the magnetic support. These nanoparticles exhibited high catalytic activity as novel magnetically recyclable acid nanocatalyst in the synthesis of a diverse range of hexahydroquinolines through one‐pot tandem reactions in excellent yields. Also, this nanocatalyst performed satisfactory catalytic maintenance of activity for the synthesis of the reaction products after 4 rounds of recycling with no considerable loss of activity.
Synthesis, structure and in vitro antiproliferative activities of oxamido‐bridged dicopper(II) complexes: A comparative study of experimental evidence and molecular docking of DNA/protein binding
Authors: Wang Ling‐Yang , Zheng Kang , Li Yan‐Tuan , Wu Zhi‐Yong , Yan Cui‐Wei
Published: July 2017

Two μ‐oxamido‐bridged dicopper(II) complexes, namely [Cu2(hmpoxd)(H2O)(phen)](ClO4) (1) and [Cu2(papo)(H2O)(phen)](ClO4)·2H2O (2), where H3hmpoxd and H3papo represent N‐(2‐hydroxy‐5‐methylphenyl)‐N′‐[3‐(dimethylamino)propyl]oxamide and N‐(2‐hydroxylphenyl)‐N′‐(3‐aminopropyl)oxamide, respectively, and phen represents 1,10‐phenanthroline, were synthesized. Single‐crystal X‐ray crystallography and other methods revealed that the two copper(II) ions in complex 1 are bridged by the cis‐hmpoxd3− with Cu···Cu separation of 5.1896(7) Å, in which the inner (Cu1) and outer (Cu2) copper(II) atoms are located in square‐planar and square‐pyramidal geometries, respectively. To evaluate the effects of bridging ligand hydrophobicity on DNA/protein binding and potential anticancer activities, comparative studies of the reactivity towards herring sperm DNA and protein bovine serum albumin (BSA) as well as cytotoxicity of complex 1 with our previously reported complex 2 were conducted theoretically and experimentally. The results indicate that the two complexes can interact interactively with DNA, and bind to BSA via the binding sites Trp213 for 1 and Trp134 for 2. Interestingly, the in vitro anticancer activities and DNA/protein binding affinities consistently follow the order of 1 > 2.
Magnetic Fe3O4 nanoparticles supported imine/Thiophene‐nickel (II) complex: A new and highly active heterogeneous catalyst for the synthesis of polyhydroquinolines and 2, 3‐dihydroquinazoline‐4(1H)‐ones
Authors: Shiri Lotfi , Heidari Leili , Kazemi Mosstafa
Published: July 2017

A new magnetically separable nickel catalyst (Ni(NO3)2−Imine/Thiophene‐Fe3O4@SiO2) was readily prepared and structurally characterized by Fourier transform infrared spectroscopy (FT‐IR), Scanning electron microscopy (SEM), Energy‐dispersive X‐ray spectroscopy (EDX), Vibrating sample magnetometer (VSM), X‐Ray diffraction (XRD) and Atomic absorption spectroscopy (AAS). The Ni(NO3)2−Imine/Thiophene‐Fe3O4@SiO2 exhibited efficient catalytic activity in the synthesis of 2,3‐dihydroquinazoline‐4(1H)‐ones and polyhydroquinolines. Catalysis research under water and solvent‐free conditions makes also this synthetic protocol ideal and fascinating from the environmental point of view. The catalyst can be magnetically recovered after the reaction and can be reused for many times without appreciable decrease in activity.
Thermodynamic modeling of phase equilibrium of carbon dioxide clathrate hydrate in aqueous solutions of promoters and inhibitors suitable for gas separation
Authors: Avula Venkata Ramana , Gupta Pawan , Gardas Ramesh L. , Sangwai Jitendra S.
Published: July 2017

Gas hydrates of CO2 in the presence of tetra‐n‐alkyl ammonium bromide (TBAB) and tetrahydrofuran (THF) show potential applications for storage. Prediction of the phase behavior of these systems is an important precursor for their successful application. In this work, a thermodynamic model is developed to predict phase equilibrium of CO2 hydrates in the presence of TBAB and THF aqueous solutions. In this work, the van der Waals and Platteeuw model is used to model the hydrate phase stability. The fugacity of hydrate former and that of water is calculated from the Peng–Robinson equation of state and the Pitzer–Mayorga–Zavitsas hydration (PMZH) model for TBAB and nonrandom two‐liquid (NRTL) models for the THF system. Further, the vapor pressure of water in the empty hydrate as well as Langmuir adsorption constants has been expressed in terms of concentration of the promoter. The model predictions is compared with available experimental data on the phase equilibrium of CO2 hydrates in the presence of TBAB and THF aqueous solution and are found to be in good agreement. Then, the developed model is also applied for the prediction of phase equilibrium conditions of the semiclathrate hydrates of CO2 in the presence of TBAB + NaCl solution. The developed model is found to interpret the promotion effects of both TBAB (with or without NaCl) and THF on phase stability conditions of CO2 hydrate. The overall average absolute deviation in pressure has been perceived to be within 3.6% for TBAB and 7.7% for TBAB + NaCl both with PMZH model and 6.9% for THF systems with NRTL model. © 2017 Curtin University of Technology and John Wiley & Sons, Ltd. StartCopText© 2017 Curtin University of Technology and John Wiley & Sons, Ltd.
Measurements and predictive modeling of water diffusion coefficients in bovine serum albumin/polymer blends for biosensors
Authors: Kachel Sibylle , Scharfer Philip , Schabel Wilhelm
Published: July 2017

The knowledge of mass transport parameters in polymer/protein blend films is of substantial interest for the preparation of glucose biosensor test strips where drying and rehydration need to be controlled. In this study, the diffusion of water in bovine serum albumin (BSA) and poly(vinylpyrrolidone) (PVP) films and blends of BSA with PVP and polyvinylalcohol is investigated and the applicability of predictive models for the diffusion coefficient in mixtures is explored. Water concentration profiles are measured with Raman spectroscopy during drying experiments under controlled conditions. Concentration‐dependent diffusion coefficients of water in the films are then determined by fitting simulated drying curves to measured data. Comparison of the resulting diffusion coefficients in the blends with a predictive logarithmic model shows good agreement. The application of such predictive models could greatly facilitate the development of polymer/protein blends in the future. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45368.
Synthesis and Electrochromic Properties of Star‐Shaped Oligomers with Phenyl Cores
Authors: Zeng Jinming , Zhang Xiaoyuan , Zhu Xiaoting , Liu Ping
Published: July 2017

A series of star‐shaped conjugated oligomers, 1,3,5‐tri(2′‐thienyl) benzene (3TB), 1,3,5‐tri(3′,4′‐ethylenedioxythienyl) benzene (3EB), 1,3,5‐tri[5′,2“‐(3”,4“‐ethylenedioxy‐thienyl)‐2′‐thienyl] benzene (3ETB), and 1,3,5‐tri[5′,2”‐(3“,4”‐ethylenedioxy‐thienyl)‐2′‐thienyl]‐4‐(3′,4′‐ethylenedioxythienyl)benzene (3TB‐4EDOT), were synthesized. The star‐shaped polymer, poly(1,3,5‐tri[5′,2“‐(3”,4“‐ethylenedioxythineyl)‐2′‐thienyl]benzene) (P3ETB), was also prepared. The electrochemical and electrochromic properties of these conjugated oligomers and polymer were investigated. These oligomer and polymer films showed reversible, clear color changes upon electrochemical doping and dedoping. The color of the P3ETB film reversibly changed from orange to blue under doping and dedoping. The switching times for doping and dedoping were 1.2 and 0.9 s, respectively.
A Note on all‐Stabilizing Proportional Controllers for Single Input–Single Output Systems
Authors: Üstoğlu İlker , Örenbaş Halit , Eren Yavuz
Published: July 2017

This paper aims to present a practical technique for the synthesis of proportional controllers for continuous time control systems. This technique depends on the generalization of the Nyquist stability criterion and promises soft computing of the crossing direction of the diagram where the plot crosses the real axis on the complex plane.
Adaptive Neural Dynamic Surface Control for Stochastic Nonlinear Time‐Delay Systems with Input and Output Constraints
Authors: Si Wen‐Jie , Dong Xun‐De , Yang Fei‐Fei
Published: July 2017

This paper presents an adaptive neural tracking control approach for uncertain stochastic nonlinear time‐delay systems with input and output constraints. Firstly, the dynamic surface control (DSC) technique is incorporated into adaptive neural control framework to overcome the problem of ‘explosion of complexity’ in the control design. By employing a continuous differentiable asymmetric saturation model, the input constraint problem is solved. Secondly, the appropriate Lyapunov‐Krasovskii functional and the property of hyperbolic tangent functions are used to deal with the unknown time‐delay terms, RBF neural network is utilized to identify the unknown systems functions, and barrier Lyapunov functions (BLFs) are designed to avoid the violation of the output constraint. Finally, based on adaptive backstepping technique, an adaptive neural control method is proposed, and it decreases the number of learning parameters. Using Lyapunov stability theory, it is proved that the designed controller can ensure that all the signals in the closed‐loop system are 4‐Moment (or 2 Moment) semi‐globally uniformly ultimately bounded (SGUUB) and the tracking error converges to a small neighborhood of the origin. Two simulation examples are provided to further illustrate the effectiveness of the proposed approach.
Can People Identify “Deceptive” or “Misleading” Items that Tend to Produce Mostly Wrong Answers?
Authors: Koriat Asher
Published: July 2017

In many domains, two‐alternative forced‐choice questions produce more correct responses than wrong responses across participants. However, some items, dubbed “deceptive” or “misleading”, produce mostly wrong answers. These items yield poor calibration and poor resolution because the dominant, erroneous response tends to be endorsed with great confidence, even greater than that of the correct response. In addition, for deceptive items, group discussion amplifies rather than mitigates error while enhancing confidence in the erroneous response. Can participants identify deceptive items when they are warned about their existence? It is argued that people's ability to discriminate between deceptive and non‐deceptive items is poor when the erroneous responses are based on the same process assumed to underlie correct responses. Indeed, participants failed to discriminate between deceptive and non‐deceptive perceptual items when they were warned that some of the items (Experiment 1) or exactly half of the items (Experiment 2) were deceptive. A similar failure was observed for general‐knowledge questions (Experiment 3) except when participants were informed about the correct answer (Experiment 4). Possibly, for these tasks, people cannot escape the dangers lurking in deceptive items. In contrast, the results suggest that participants can identify deceptive problems for which the wrong answer stems from reliance on a fast, intuitive process that differs from the analytic mode that is likely to yield correct answers (Experiment 5). The practical and theoretical implications of the results were discussed. Copyright © 2017 John Wiley & Sons, Ltd.
Validated LC–MS/MS method for quantitation of demethylbellidifolin in rat plasma and its application to pharmacokinetic and bioavailability studies
Authors: Zhang Jie , Yan Huiyu , Qu Xiaoyu , Zhou Wei
Published: July 2017

Demethylbellidifolin, a major xanthone compound of Swertia davidi Franch, shows many beneficial pharmacological effects including antioxidation, anti‐inflammation, anti‐fibrosis and cardiovascular protection effects. In this research, a rapid and sensitive LC–MS/MS method for the quantitative analysis of demethylbellidifolin in rat plasma was developed. The demethylbellidifolin and internal standard of aurantio‐obtusin were extracted from 50 μL of rat plasma samples with ethyl acetate, then the dried residue was reconstituted and injected in an HPLC system with Zorbax SB‐C18 analytical column (2.1 × 100 mm, 3.5 μm) and eluted with the mobile phase consisting of methanol and 0.2% formic acid aqueous solution (80:20, v/v). Quantification was performed using a TSQ Quantum Ultra mass spectrometer in negative ESI using selected reaction monitoring mode of the transitions m/z 259.1 → 215.1 for demethylbellidifolin and 329.0 → 314.2 for the IS. Excellent linearity was observed between 1.92 and 960 ng/mL with a limit of quantitation of 1.92 ng/mL. Intra‐ and inter‐day precision (RSD) values of quality control samples were both <8.3%. This study was successfully utilized for the pharmacokinetic profiles of demethylbellidifolin in rats after oral or intravenous administration. The oral bioavailability of demethylbellidifolin was 3.6%.
Development and validation of a high‐performance liquid chromatography method for the quantification of talazoparib in rat plasma: Application to plasma protein binding studies
Authors: Hidau Mahendra Kumar , Kolluru Srikanth , Palakurthi Srinath
Published: July 2017

A sensitive and selective RP‐HPLC method has been developed and validated for the quantification of a highly potent poly ADP ribose polymerase inhibitor talazoparib (TZP) in rat plasma. Chromatographic separation was performed with isocratic elution method. Absorbance for TZP was measured with a UV detector (SPD‐20A UV–vis) at a λmax of 227 nm. Protein precipitation was used to extract the drug from plasma samples using methanol–acetonitrile (65:35) as the precipitating solvent. The method proved to be sensitive and reproducible over a 100–2000 ng/mL linearity range with a lower limit of quantification (LLQC) of 100 ng/mL. TZP recovery was found to be >85%. Following analytical method development and validation, it was successfully employed to determine the plasma protein binding of TZP. TZP has a high level of protein binding in rat plasma (95.76 ± 0.38%) as determined by dialysis method.
Effect of the Polyphenol Rich Ethyl Acetate Fraction from the Leaves of Lycium chinenseMill. on Oxidative Stress, Dyslipidemia, and Diabetes Mellitus in Streptozotocin‐Nicotinamide Induced Diabetic Rats
Authors: Olatunji Opeyemi J. , Chen Hongxia , Zhou Yifeng
Published: July 2017

Lycium chinenseMill., popularly known as boxthorn, is a plant that is traditionally used for treating night sweat, cough, inflammation and diabetes mellitus. However, the leaves have received little or no attention despite their potentials as a potent therapeutic agent. This study was aimed at investigating the hypoglycemic and hypolipidemic effects of the polyphenols‐rich ethyl acetate fraction from the leaves of Lycium chinenseMill. on streptozotocin‐nicotinamide induced diabetic rats. The ethyl acetate fraction (LFE) was selected and orally gavaged at 100, 200, and 400 mg/kg dose to streptozotocin (STZ)‐nicotinamide induced diabetic rats. The rats’ body weight, fasting blood glucose (FBG), lipid profile and oxidative stress markers were evaluated after the treatment period. Treatment with LFE resulted in a significant decrease in the FBG level, altered lipid profiles, and reduced the activities of the enzymes alkaline phosphatase (ALP), aspartate transaminase (AST), alanine transaminase (ALT) in the treated diabetic rats. Furthermore, LFE significantly elevated the antioxidant status (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH‐Px) activities) and reducing malondialdehyde (MDA) levels in the treated rats. The present study has revealed that L. chinenseMill. possess anti‐hyperglycemic and anti‐hyperlipidemic properties which is mediated through modulation of oxidative stress and polyphenolics might be responsible for the action.
Chemical Compositions and Antioxidant Activities of Essential Oils Extracted from the Petals of Three Wild Tree Peony Species and Eleven Cultivars
Authors: Zhang Xiao‐Xiao , Sun Jia‐Yi , Niu Li‐Xin , Zhang Yan‐Long
Published: July 2017

The aim of this study was to investigate the essential oil (EO) compositions and antioxidant activities from petals of three wild tree peony species (Paeonia delavayi, P. lutea, and P. rockii) and eleven P. suffruticosa cultivars from different cultivar groups. The EOs yields varied from 0.63% to 1.25% (v/v) among samples when using supercritical CO2 extraction. One hundred and sixty‐three components were detected by GC/MS; and among them, linalool oxide, (Z)‐5‐dodecen‐1‐yl acetate, nonadecane, (Z)‐5‐nonadecene, heneicosane, phytol, and linoleic acid ethyl ester were dominant. According to hierarchical cluster analysis, principal component analysis and correspondence analysis, P. lutea, P. delavayi, and ‘High Noon’ were clustered in a group described as having a refreshing herbal‐like note due to high rates of phytol and linalool oxide. Notably, P. lutea and P. delavayi also had strong DPPH and ABTS radical scavenging activities. These results suggest that P. lutea and P. delavayi are the most promising candidates as useful sources of fragrances and natural antioxidants.
Processes of change in an offender personality disorder pathway prison progression unit
Authors: McMurran Mary , Delight Steve
Published: July 2017

Background

In England, the National Offender Management Service and the NHS have come together to try and improve management and treatment of offenders with personality disorder by developing a pathways approach to assist high‐risk male offenders with severe personality disorder.

Aim

The aim of the study is to investigate service user and staff perceptions of change in this pathway.

Methods

Semi‐structured interviews were conducted with 16 prisoners and 16 staff in one unit in a London‐based personality disorder pathway. The four core questions were as follows: (1) what changes do you think have occurred?; (2) what do you think helped make these changes?; (3) how do you think this helped change?; and (4) what hindered positive change? Thematic analysis was applied to the narratives.

Results

Prisoners and staff separately reported similar changes, each observing that prisoners became less anti‐authority, improved their self‐understanding, developed feelings of self‐worth and increased their optimism about change. There was similar consensus on what they thought had brought about change – primarily development of trusting relationships. These allowed a psychological perspective on understanding prisoners' behaviour. Maintenance of this approach was seen as demanding, with barriers including ‘security restrictions’ curtailing purposeful activities, visits and community contact and ‘stigmatising beliefs about personality disorder’ in the wider prison.

Implications for Practice

Findings suggest that shared goals and progress are achievable. Difficulties in sustaining these will require a range of solutions, but wider support from the prison is essential to containing hostility to such prisoners and specialised work and ensuring the provision of purposeful activity. Copyright © 2017 John Wiley & Sons, Ltd.
Examining the effect of social bonds on the relationship between ADHD and past arrest in a representative sample of adults
Authors: van der Maas Mark , Kolla Nathan J. , Erickson Patricia G. , Wickens Christine M. , Mann Robert E. , Vingilis Evelyn
Published: July 2017

Background

Several studies have found a connection between attentional deficit hyperactivity disorder (ADHD) and criminal behaviour in clinical and prison samples of adults, but there is a lack of representative general population data on this.

Aim

To test relationships between histories of ADHD and arrest. Our main research question was whether any such relationship is direct or best explained by co‐occurring variables, especially indicators of social bonds.

Method

Data were from a sample of 5,376 adults (18+) representative of the general population of Ontario, Canada. Logistic regression analysis was used to explore the relationship between self‐reported arrest on criminal charges and ADHD as measured by the Adult Self Report Scale (ASRS‐v1.1). Indicators of strong social bonds (post secondary education, household size) and weak bonds (drug use, antisocial behaviours, alcohol dependence) were also obtained at interview and included in the statistical models.

Results

In a main effects model, screening positive for ADHD was twice as likely (OR 2.05 CI 1.30, 3.14) and past use of medications for ADHD three times as likely (OR 3.94 CI 2.46, 6.22) to be associated with ever having been arrested. These associations were no longer significant after controls for weak and strong social bonds were added to the models. In the best fitting statistical model, ever having been arrested was not associated with ADHD, but it was significantly associated with indicators of strong and weak social bonds.

Conclusions

The observed connection between ADHD and criminality may be better understood through their shared relationships with indicators of poor social bonds. These include antisocial behaviour more generally, but also drug use and failure to progress to any form of tertiary education, including vocational training. Copyright © 2017 John Wiley & Sons, Ltd.
High Durability and Performance of a Platinum Electrocatalyst Supported on Sulfonated Macromolecules Coated Carbon Nanotubes
Authors: Yang Zehui , Li Jing , Zhang Quan , Ling Ying , Yu Xinxin , Cai Weiwei
Published: July 2017

Low durability and fuel cell performance block the widespread application of polymer electrolyte fuel cells (PEFCs). Here, we deposit platinum nanoparticles on carbon nanotubes (CNTs) before coating by end‐capped hyperbranched sulfonated macromolecules (E‐HBM), which could provide sufficient proton conductivity in catalyst layer thanks to the presence of −SO3H groups. The fabricated electrocatalyst loses 43 % of initial electrochemical surface area (ECSA) after 200 000 potential cycles from 1.0 V to 1.5 V vs. RHE, which is 3 and 20 times higher than that of noncoated and commercial electrocatalysts, respectively. The mass and specific activities of newly fabricated electrocatalyst measured before and after durability test are 1.4 times higher than that of commercial carbon black/Pt. Nafion ionomer‐free membrane electrode assembly is fabricated from the newly designed electrocatalyst, and its fuel‐cell performance reaches 668 mW cm−2 with Pt loading of 0.1 mg cm−2, which is twice higher than that of commercial CB/Pt thanks to the homogeneous conductive macromolecules (E‐HBM) layers on CNTs acting as ionomer and facilitating the proton delivery in the catalyst layer.
Monodispersed Mesoporous Silica Spheres Supported Co3O4 as Robust Catalyst for Oxygen Evolution Reaction
Authors: Deng Xiaohui , Rin Ritsu , Tseng Jo‐Chi , Weidenthaler Claudia , Apfel Ulf‐Peter , Tüysüz Harun
Published: July 2017

Monodispersed mesoporous silica spheres (MSS) with fibrous nanostructure and highly open porosity were fabricated by a facile one‐pot synthetic route and loaded with Co3O4 nanoclusters for catalyzing the oxygen evolution reaction with Ru(bpy)32+–S2O82− photosensitizer and sacrificial reagent system. The effect of the loading amount on the morphology and microstructure of Co3O4 was investigated and it was found that lower Co3O4 content in the composite materials results in smaller crystallite size, which in turn leads to significantly enhanced oxygen evolution activity. Furthermore, owing to the monodispersity of the spheres and good accessibility of active species offered by the fibrous pore structure, the material shows a clear advantage over nonsupported Co3O4 nanoparticles and the commonly used ordered mesoporous silica supports such as KIT‐6 and SBA‐15.
Computational Elucidation of a Role That Brønsted Acidification of the Lewis Acid‐Bound Water Might Play in the Hydrogenation of Carbonyl Compounds with H2 in Lewis Basic Solvents
Authors: Heshmat Mojgan , Privalov Timofei
Published: July 2017

Brønsted acidification of water by Lewis acid (LA) complexation is one of the fundamental principles in chemistry. Using transition‐state calculations (TS), herein we investigate the role that Brønsted acidification of the LA‐bound water might play in the mechanism of the hydrogenation of carbonyl compounds in Lewis basic solvents under non‐anhydrous conditions. The potential energy scans and TS calculations were carried out with a series of eight borane LAs as well as the commonly known strong LA AlCl3 in 1,4‐dioxane or THF as Lewis basic solvents. Our molecular model consists of the dative LA‐water adduct with hydrogen bonds to acetone and a solvent molecule plus one additional solvent molecule that participates is the TS structure describing the cleavage of H2 at acetone's carbonyl carbon atom. In all the molecular models applied here, acetone (O=CMe2) is the archetypical carbonyl substrate. We demonstrate that Brønsted acidification of the LA‐bound water can indeed lower the barrier height of the solvent‐involving H2‐cleavage at the acetone's carbonyl carbon atom. This is significant because at present it is believed that the mechanism of the herein considered reaction is described by the same mechanism regardless of whether the reaction conditions are strictly anhydrous or non‐anhydrous. Our results offer an alternative to this belief that warrants consideration and further study.
Structural Study of a New HIV‐1 Entry Inhibitor and Interaction with the HIV‐1 Fusion Peptide in Dodecylphosphocholine Micelles
Authors: Pérez Yolanda , Gómara Maria José , Yuste Eloísa , Gómez‐Gutierrez Patricia , Pérez Juan Jesús , Haro Isabel
Published: July 2017

Previous studies support the hypothesis that the envelope GB virus C (GBV‐C) E1 protein interferes the HIV‐1 entry and that a peptide, derived from the region 139–156 of this protein, has been defined as a novel HIV‐1 entry inhibitor. In this work, we firstly focus on the characterization of the structural features of this peptide, which are determinant for its anti‐HIV‐1 activity and secondly, on the study of its interaction with the proposed viral target (i.e., the HIV‐1 fusion peptide). We report the structure of the peptide determined by NMR spectroscopy in dodecylphosphocholine (DPC) micelles solved by using restrained molecular dynamics calculations. The acquisition of different NMR experiments in DPC micelles (i.e., peptide–peptide titration, diffusion NMR spectroscopy, and addition of paramagnetic relaxation agents) allows a proposal of an inhibition mechanism. We conclude that a 18‐mer peptide from the non‐pathogenic E1 GBV‐C protein, with a helix–turn–helix structure inhibits HIV‐1 by binding to the HIV‐1 fusion peptide at the membrane level, thereby interfering with those domains in the HIV‐1, which are critical for stabilizing the six‐helix bundle formation in a membranous environment.
Ketone Formation from Carboxylic Acids by Ketonic Decarboxylation: The Exceptional Case of the Tertiary Carboxylic Acids
Authors: Oliver‐Tomas Borja , Renz Michael , Corma Avelino
Published: July 2017

For the reaction mechanism of the ketonic decarboxylation of two carboxylic acids, a β‐keto acid is favored as key intermediate in many experimental and theoretical studies. Hydrogen atoms in the α‐position are an indispensable requirement for the substrates to react by following this mechanism. However, isolated observations with tertiary carboxylic acids are not consistent with it and these are revisited and discussed herein. The experimental results obtained with pivalic acid indicate that the ketonic decarboxylation does not occur with this substrate. Instead, it is consumed in alternative reactions such as disintegration into isobutene, carbon monoxide, and water (retro‐Koch reaction). In addition, the carboxylic acid is isomerized or loses carbon atoms, which converts the tertiary carboxylic acid into carboxylic acids bearing α‐proton atoms. Hence, the latter are suitable to react through the β‐keto acid pathway. A second substrate, 2,2,5,5‐tetramethyladipic acid, reacted by following the same retro‐Koch pathway. The primary product was the monocarboxylic acid 2,2,5‐trimethyl‐4‐hexenoic acid (and its double bond isomer), which might be further transformed into a cyclic enone or a lactone. The ketonic decarboxylation product, 2,2,5,5‐tetramethylcyclopentanone was observed in traces (<0.2 % yield). Therefore, it can be concluded that the observed experimental results further support the proposed mechanism for the ketonic decarboxylation via the β‐keto acid intermediate.
Diverse Chiral Scaffolds from Diethynylspiranes: All‐Carbon Double Helices and Flexible Shape‐Persistent Macrocycles
Authors: Castro‐Fernández Silvia , Yang Ren , García A. Patricio , Garzón Ignacio L. , Xu Hai , Petrovic Ana G. , Alonso‐Gómez J. Lorenzo
Published: July 2017

State‐of‐the‐art chiroptical spectroscopies are valuable tools for structural elucidation. However, the potential of these spectroscopies for everyday applications has not been exploited to date partially due to the lack of sufficiently stable and efficient chiroptical systems. To this end, the development of suitable chiroptical structures is essential. Herein, we present the synthesis of spiro‐compounds (P2)‐1 and (P4)‐2 as well as (M2)‐1 and (M4)‐2 exhibiting remarkable chiroptical responses. Theoretical simulations show that (P2)‐1, constituted by two (P)‐configured spiranic chiral axes, presents an all‐carbon double helix structure with (M)‐helicity. On the other hand, molecular dynamic simulations reveal (P4)‐2 to have a single path for geometry‐modification along its flat conformational space, certifying it as a chiral flexible shape‐persistent macrocycle. Geometric quantification of chirality has been used to compare the spiranic derivatives presented herein.
Enantioselective analysis of ibuprofen enantiomers in mice plasma and tissues by high‐performance liquid chromatography with fluorescence detection: Application to a pharmacokinetic study
Authors: Przejczowska‐Pomierny Katarzyna , Włodyka Monika , Cios Agnieszka , Wyska Elżbieta
Published: July 2017

A direct fluorometric high‐performance liquid chromatography (HPLC) method was developed and validated for the analysis of ibuprofen enantiomers in mouse plasma (100 μl) and tissues (brain, liver, kidneys) using liquid–liquid extraction and 4‐tertbutylphenoxyacetic acid as an internal standard. Separation of enantiomers was accomplished in a Chiracel OJ‐H chiral column based on cellulose tris(4‐methylbenzoate) coated on 5 μm silica‐gel, 250 x 4.6 mm at 22 °C with a mobile phase composed of n‐hexane, 2‐propanol, and trifluoroacetic acid that were delivered in gradient elution at a flow rate of 1 ml min−1. A fluorometric detector was set at: λexcit. = 220 nm and λemis. = 290 nm. Method validation included the evaluation of the selectivity, linearity, lower limit of quantification (LLOQ), within‐run and between‐run precision and accuracy. The LLOQ for the two enantiomers was 0.125 μg ml−1 in plasma, 0.09 μg g−1 in brain, and 0.25 μg g−1 in for liver and kidney homogenates. The calibration curves showed good linearity in the ranges of each enantiomers: from 0.125 to 35 μg ml−1 for plasma, 0.09–1.44 μg g−1 for brain, and 0.25–20 μg g−1 for liver and kidney homogenates. The method was successfully applied to a pharmacokinetic study of ibuprofen enantiomers in mice treated i.v. with 10 mg kg−1 of racemate.
Enantioresolution and stereochemical characterization of two chiral sulfoxides endowed with COX‐2 inhibitory activity
Authors: Sardella Roccaldo , Ianni Federica , Di Michele Alessandro , Di Capua Angela , Carotti Andrea , Anzini Maurizio , Natalini Benedetto
Published: July 2017

The capacity of nonsteroidal antiinflammatory drugs (NSAIDs) to prevent prostanoids biosynthesis through the inhibition of COX‐2 enzyme is related to their structural backbone, based on the fusion of a cis‐stilbene unit with a variety of heterocyclic and carbocyclic rings. By this route, a series of new selective COX‐2 inhibitors was developed, by maintaining the 4‐methylsulfone or 4‐methylsulfonamide substituent on the phenyl moiety, essential for their activity. In this frame, two novel propyl sulfoxide derivatives were synthesized, which proved selective and sufficiently potent COX‐2 inhibition activity when tested as racemates. In the present study, the use of a cellulose tris(3,5‐dichlorophenylcarbamate)‐based chiral stationary phase, in a polar‐organic mode of elution, enabled the successful enantioseparation of the investigated compounds. The developed chromatography method reveals a useful tool of monitoring in view of a proper forthcoming enantioselective synthetic protocol. Moreover, the optimized chromatographic conditions allowed the isolation of appropriate amounts of single enantiomers for the electronic circular dichroism studies that, coupled with in silico simulations, allowed assessing the absolute configuration of each species.
Light Sources for Photochemical Processes – Estimation of Technological Potentials
Authors: Sender Maximilian , Ziegenbalg Dirk
Published: July 2017

This work theoretically evaluates light sources currently commercially available for the suitability to drive photoreactions. Comparative evaluation of different light sources reveals significant advantages of light‐emitting diodes (LEDs) in the near UV and visible region, underlining the general superiority of narrow‐band monochromatic light sources for photochemical processes. A generic analysis based on the average volumetric rate of photon absorption shows the limits resulting from physical fundamentals and the importance of the photon fluence rate for process intensification.
Synthesis of Quinoline and 1,2,3,4‐Tetrahydroquinoline Derivatives from Substituted o‐Nitrotoluenes via Cesium‐promoted [2 + 4] Cycloaddition
Authors: Guo Weijie , Yi Maocong , Wang Jianhui , Liu Guiyan
Published: July 2017

An atom economical highly efficient method has been developed for the synthesis of quinoline and 1,2,3,4‐tetrahydroquinoline derivatives from o‐nitrotoluenes bearing electron‐withdrawing groups and olefins (acrylic esters, acrylonitriles, and methyl acrylates) via a base‐catalyzed [2 + 4] cycloaddition. This simple, rapid, and environment‐ friendly method provides a practical pathway for the synthesis of quinoline and 1,2,3,4‐tetrahydroquinoline derivatives. The starting materials are readily available and 37 products were obtained in good to excellent yields.