bluuebunny/crossref_metadata_2025 huggingface dataset:
Superplastic Property of the Ti–6Al–4V Alloy with Ultrafine‐Grained Heterogeneous Microstructure
Authors: Matsumoto Hiroaki , Nishihara Takuro , Velay Vincent , Vidal Vanessa
Published: August 2017

Ti–6Al–4V alloy having a heterogeneous microstructure composed of ultrafine‐equiaxed‐α‐grains and fine‐lamellar‐α‐grains is investigated for microstructural changes during superplastic deformation at temperature of 700 °C. The Ti–6Al–4V alloy having an optimum fraction of fine‐lamellar‐α‐grains exhibits an excellent superplastic property and the highest elongation of 583% (tested at 700 °C 10−3 s−1). This is mainly due to the optimized activation of grain‐boundary‐sliding and additional accommodation mechanism associated with frequent occurrences of dynamic recrystallization and β precipitation at boundaries during deformation of the heterogeneous starting microstructure. The present result suggests the possibility that optimizing the starting microstructure so as to have an optimum heterogeneous‐microstructure serves as an additional stress accommodation mechanism and leads to a large superplastic elongation.
Enhancing the Strength and Ductility in Mg–Zn–Ce Alloy through Achieving High Density Precipitates and Texture Weakening
Authors: Du Yuzhou , Zheng Mingyi , Qiao Xiaoguang , Jiang Bailing
Published: August 2017

The microstructure with weak fiber texture and dense precipitates is designed and produced through extrusion and subsequent ageing treatment of Mg–6Zn–0.2Ce (wt%) alloy. Results show that ageing treatment improves the strength of the as‐extruded Mg–6Zn–0.2Ce (wt%) alloy and retains the ductility. The peak‐aged alloy exhibits a good combination of strength and ductility, which is superior to the commercial Mg alloy. The yield strength and elongation to fracture of the peak‐aged Mg–6Zn–0.2Ce (wt%) alloy are 225 MPa and 32.1%, respectively. The strength improvement of the peak‐aged alloy is attributed to dense rod‐like precipitates, and the superior ductility is mainly due to weaker texture and homogeneous microstructure.
Shoulder Dystocia Delivery by Emergency Medicine Residents: A High‐fidelity versus a Novel Low‐fidelity Simulation Model—A Pilot Study
Authors: Hart Danielle , Nelson Jessie , Moore Johanna , Gross Eric , Oni Adeleki , Miner James
Published: August 2017

Background

Shoulder dystocia (SD) requires emergent intervention to prevent maternal and fetal harm, and simulation models for training can be expensive. We developed a novel, cheap and easily transportable low‐fidelity simulation (LFS) model to compare to a commercially available high‐fidelity simulation (HFS) model.

Methods

Emergency medicine residents were randomized to training on the HFS or novel LFS model. Subjects completed a pretest and a 1‐week and 6‐month posttest including a self‐assessment and a simulated SD delivery.

Results

Twenty‐seven of the 43 residents completed the study (63%). The number of individuals performing dangerous maneuvers at baseline was similar, 1 week after training was five in HFS and 11 in LFS (p = 0.08) groups and at 6 months was again similar between groups. Mean checklist scores for appropriate actions increased 1 week after training but returned to baseline by 6 months and were similar between groups. The rate of successful delivery, median time to successful delivery, and maximum force applied improved at 1 week and was sustained at 6 months in both groups.

Conclusion

Within our limited study population, we did not find a large difference in the occurrence of dangerous actions during simulated SD delivery following HFS and LFS training. Our novel and easily transportable LFS trainer, assembled for less than US$10 each, may be a useful tool to train inexperienced providers on the steps of this procedure. However, this requires further study, as does whether HFS models with force monitoring capabilities may be helpful to train providers to minimize dangerous maneuvers such as the application of excessive force.
Pac13 is a Small, Monomeric Dehydratase that Mediates the Formation of the 3′‐Deoxy Nucleoside of Pacidamycins
Authors: Michailidou Freideriki , Chung Chun‐wa , Brown Murray J. B. , Bent Andrew F. , Naismith James H. , Leavens William J. , Lynn Sean M. , Sharma Sunil V. , Goss Rebecca J. M.
Published: August 2017

The uridyl peptide antibiotics (UPAs), of which pacidamycin is a member, have a clinically unexploited mode of action and an unusual assembly. Perhaps the most striking feature of these molecules is the biosynthetically unique 3′‐deoxyuridine that they share. This moiety is generated by an unusual, small and monomeric dehydratase, Pac13, which catalyses the dehydration of uridine‐5′‐aldehyde. Here we report the structural characterisation of Pac13 with a series of ligands, and gain insight into the enzyme's mechanism demonstrating that H42 is critical to the enzyme's activity and that the reaction is likely to proceed via an E1cB mechanism. The resemblance of the 3′‐deoxy pacidamycin moiety with the synthetic anti‐retrovirals, presents a potential opportunity for the utilisation of Pac13 in the biocatalytic generation of antiviral compounds.
An Insoluble Benzoquinone‐Based Organic Cathode for Use in Rechargeable Lithium‐Ion Batteries
Authors: Luo Zhiqiang , Liu Luojia , Zhao Qing , Li Fujun , Chen Jun
Published: August 2017

Application of organic electrode materials in rechargeable batteries has attracted great interest because such materials contain abundant carbon, hydrogen, and oxygen elements. However, organic electrodes are highly soluble in organic electrolytes. An organic electrode of 2,3,5,6‐tetraphthalimido‐1,4‐benzoquinone (TPB) is reported in which rigid groups coordinate to a molecular benzoquinone skeleton. The material is insoluble in aprotic electrolyte, and demonstrates a high capacity retention of 91.4 % (204 mA h g−1) over 100 cycles at 0.2 C. The extended π‐conjugation of the material contributes to enhancement of the electrochemical performance (155 mA h g−1 at 10 C). Moreover, density functional theory calculations suggest that favorable synergistic reactions between multiple carbonyl groups and lithium ions can enhance the initial lithium ion intercalation potential. The described approach may provide a novel entry to next‐generation organic electrode materials with relevance to lithium‐ion batteries.
Neuer Ansatz zur Bestimmung des Schubmoduls für einen Dämmstoff
Authors: Weiler Torsten , Kurz Wolfgang , Pahn Matthias
Published: August 2017

Maßgebend für die wirtschaftliche Bemessung eines Stahlbetonsandwichelementes ist die realitätsnahe Ermittlung der Verformungen und der inneren Schnittgrößenverteilung. Entscheidend für diese Ermittlung sind unter anderem genaue Kenntnisse bezüglich der Materialeigenschaften des Dämmstoffes. Deshalb wurde das Materialverhalten für den eingesetzten Dämmstoff unter einer Druck‐ und Schubbeanspruchung anhand von umfangreichen experimentellen Untersuchungen analysiert. Es hat sich herausgestellt, dass die Bestimmung der Scherfestigkeit sowie des Schubmoduls in Anlehnung an die geltende Norm DIN EN 12090 nicht eindeutig und damit unzufrieden stellend ist. Über‐ oder Unterschätzungen des Schubmoduls führen bei der Ermittlung der inneren Schnittgrößenverteilung und der Verformungen eines Sandwichelementes zu ungenauen und gegebenenfalls zu falschen Ergebnissen. Deshalb wurde ein neuer Ansatz zur Ermittlung des Schubmoduls für einen Dämmstoff entwickelt. Das neue Vorgehen zur Ermittlung des Schubmoduls liefert gleichzeitig hilfreiche Werte in Form von Spannungs‐ und Verformungsgrenzen, die die Bemessung von Sandwichelementen optimieren können.
Activation processes in ligand‐activated G protein‐coupled receptors: A case study of the adenosine A2A receptor
Authors: Prosser R. Scott , Ye Libin , Pandey Aditya , Orazietti Alexander
Published: August 2017

Here we review concepts related to an ensemble description of G‐protein‐coupled receptors (GPCRs). The ensemble is characterized by both inactive and active states, whose equilibrium populations and exchange rates depend sensitively on ligand, environment, and allosteric factors. This review focuses on the adenosine A2 receptor (A2AR), a prototypical class A GPCR. 19F Nuclear Magnetic Resonance (NMR) studies show that apo A2AR is characterized by a broad ensemble of conformers, spanning inactive to active states, and resembling states defined earlier for rhodopsin. In keeping with ideas associated with a conformational selection mechanism, addition of agonist serves to allosterically restrict the overall degrees of freedom at the G protein binding interface and bias both states and functional dynamics to facilitate G protein binding and subsequent activation. While the ligand does not necessarily “induce” activation, it does bias sampling of states, increase the cooperativity of the activation process and thus, the lifetimes of functional activation intermediates, while restricting conformational dynamics to that needed for activation.
Effect of erbium ion concentration on structural and luminescence properties of lead borosilicate glasses for fiber amplifiers
Authors: Babu Midde Reddi , Madhusudhana Rao N. , Mohan Babu A.
Published: August 2017

This investigation reports, the effect of the concentration of erbium and lead ions on the physical, structural and optical properties of lead borosilicate glasses. These glasses were synthesized by the melt quench method. In the synthesis, the concentration of the erbium (Er3+) ion was varied in the order of 0.0, 0.1, 0.5, 1.0 and 2.0 mol% and lead (Pb2+) ion was varied in the order of 30, 29.9, 29.5, 29 and 28 mol%. The glasses were analyzed using X‐ray diffraction (XRD), Fourier transform infrared (FT‐IR) and UV–vis–NIR spectroscopy. From XRD, the amorphous nature of lead borosilicate glasses was confirmed. The functional groups which were present in the glasses have been identified by analyzing the FT‐IR spectrum. From the absorption spectra, the oscillator strengths as well as the Judd–Ofelt (JO) intensity parameters were determined and compared with other hosts. The JO intensity parameters were further used to calculate certain radiative properties for the excited luminescent levels of Er3+ ion. From emission spectra, full width at half maxima (FWHM), stimulated emission cross‐sections (σe) and certain lasing parameters were evaluated and compared with reference host glasses. The lifetimes of 4I13/2 excited level of Er3+ ion have also been recorded and analyzed. The calculated and experimental lifetimes were compared in terms of quantum efficiencies. From the photoluminescence analysis, the erbium doped lead borosilicate glasses well suited for optical fiber amplifiers are discussed.
Differentially activated Src kinase in chemo‐naïve human primary osteosarcoma cells and effects of a Src kinase inhibitor
Authors: Laschi Marcella , Bernardini Giulia , Geminiani Michela , Manetti Fabrizio , Mori Mattia , Spreafico Adriano , Campanacci Domenico , Capanna Rodolfo , Schenone Silvia , Botta Maurizio , Santucci Annalisa
Published: August 2017

The therapeutic treatment of osteosarcoma (OS), a rare malignant teenage cancer of the skeletal system, still represents a great challenge as patient survival after conventional protocol chemotherapy treatment has not improved in the last four decades leaving poor patient prognoses. Therefore, many efforts have been done to find increasingly reliable OS cell models and to identify “druggable” targets in OS, in order to identify novel effective therapeutic approaches and treatment strategies. In this contest, the more successful use of patient‐derived cell cultures in respect to human commercial lines and findings of Src kinase deregulation in cancer, prompted us to study for the first time the activation state of Src and the potential activity of our Src inhibitor SI‐83 in a number of chemo‐naïve patient‐derived primary OS cells. We here demonstrate that Src is hyperactivated in OS cells in respect to the nonmalignant counterpart and that SI‐83 is able to strongly decrease cell viability, proliferation, Src416 phosphorylation, and cell migration. © 2017 BioFactors, 43(6):801–811, 2017
Recent Developments on Genetic Engineering of Microalgae for Biofuels and Bio‐Based Chemicals
Authors: Ng I‐Son , Tan Shih‐I , Kao Pei‐Hsun , Chang Yu‐Kaung , Chang Jo‐Shu
Published: August 2017

Microalgae serve as a promising source for the production of biofuels and bio‐based chemicals. They are superior to terrestrial plants as feedstock in many aspects and their biomass is naturally rich in lipids, carbohydrates, proteins, pigments, and other valuable compounds. Due to the relatively slow growth rate and high cultivation cost of microalgae, to screen efficient and robust microalgal strains as well as genetic modifications of the available strains for further improvement are of urgent demand in the development of microalgae‐based biorefinery. In genetic engineering of microalgae, transformation and selection methods are the key steps to accomplish the target gene modification. However, determination of the preferable type and dosage of antibiotics used for transformant selection is usually time‐consuming and microalgal‐strain‐dependent. Therefore, more powerful and efficient techniques should be developed to meet this need. In this review, the conventional and emerging genome‐editing tools (e.g., CRISPR‐Cas9, TALEN, and ZFN) used in editing the genomes of nuclear, mitochondria, and chloroplast of microalgae are thoroughly surveyed. Although all the techniques mentioned above demonstrate their abilities to perform gene editing and desired phenotype screening, there still need to overcome higher production cost and lower biomass productivity, to achieve efficient production of the desired products in microalgal biorefineries.
Bipolar Host Material for Phosphorescent OLEDs Based on 2,7‐Diazacarbazole as a New Electron‐transporting Unit
Authors: Cha Jae‐Ryung , Lee Chil Won , Gong Myoung‐Seon
Published: August 2017

The novel electron‐transporting moiety of 2,7‐diazacarbazole was used to construct a bipolar host molecule for phosphorescent organic light‐emitting diodes (PHOLEDs). This moiety was incorporated with typical hole‐transporting carbazole moieties to synthesize a 2,7‐diazacarbazole/carbazole hybrid called 9‐(3,5‐bis(carbazol‐9‐yl)phenyl)–2,7‐diazacarbazole. The hybrid exhibits a high triplet energy above 2.88 eV and very high glass transition temperature of Tg = 148°C. It shows good thermal stability owing to the rigid nature of its symmetrical bipolar structure. The 2,7‐diazacarbazole‐based host material turns on at 3.6 and 3.7 V and approaches external quantum efficiencies above 16.0 and 22.6% in blue and green PHOLEDs, respectively. These results demonstrate that 2,7‐diazacarbazole should be an excellent electron‐transporting unit for bipolar phosphorescent hosts.
Influences of Graphene Surface Treatment Temperature on a Growth of Al2O3 Film by Atomic Layer Deposition on Graphene
Authors: Park Yong Hyun , Lee Sang Woon
Published: August 2017

Influences of temperature on graphene surface treatment using trimethylaluminium (TMA) and H2O were investigated for a growth of Al2O3 film by atomic layer deposition (ALD) on graphene. It has been reported that a nucleation of Al2O3 film on the graphene surface was enhanced significantly by a surface treatment using TMA and H2O at 100 °C prior to the deposition of Al2O3 film by ALD at the same temperature. Here, we investigate influences of the surface treatment temperature on the nucleation of Al2O3 film grown by ALD on graphene surface. It is revealed that the nucleation of Al2O3 film is degraded as the surface treatment temperature increases from 150 to 200°C. The origin of the deteriorated nucleation of Al2O3 film is attributed to a decreased density of C–O and OC–O defects on the graphene surface at the high temperature (200 °C).
High glucose and free fatty acids induce endothelial progenitor cell senescence via PGC‐1α/SIRT1 signaling pathway
Authors: Song Xiaoxiao , Yang Boyun , Qiu Fuyu , Jia Minyue , Fu Guosheng
Published: August 2017

The objective of the research was to investigate the function of endothelial progenitor cells (EPCs) in the conditions of high glucose and lipids, which has been widely used to mimic the metabolic disorder that occurs in type 2 diabetic mellitus, and further to verify the role of PGC‐1α and SIRT1, cellular energy metabolism regulators, in the process of senescence of EPCs with these combined stimuli. Circulating EPCs were incubated in absence or presence of high glucose (25 mM), FFA (200 µM) or both. EPCs senescence was assessed by β‐galactosidase staining, EPCs telomerase activity was measured by telomeric repeat ampli­fication protocol assay, in vitro angiogenesis assay and MTT assays were performed to assess angiogenesis and proliferation ability of EPCs. The results showed that combined stimuli inhibited EPCs reendothelialization ability in vitro, accelerated EPCs senescence and decreased the telomerase activity. Meanwhile, with combined stimuli, the expression of PGC‐1α increased whereas SIRT1 expression decreased in EPCs accompanied by activation of P53/P21 signaling pathway. Conversely, transfection of EPCs with PGC‐1α‐siRNA rescued EPCs premature senescence and up‐regulated SIRT1 and decreased P53/P21 expression, correlating closely with the down‐regulation of PGC‐1α itself. In addition, the combined stimuli induced up‐regulation of PGC‐1α expression was partly mediated by ROS and P38 signaling pathway. Overall, the data presented here identify PGC‐1α as a potent negative regulator of EPCs’ senescence under combined stimuli, which is partly mediated by SIRT1/P53/P21 signaling pathway.
Origin and Abatement of Heterogeneity at the Support Granule Scale of Silver on Silica Catalysts
Authors: Plessers Eva , van den Reijen Jeroen E. , de Jongh Petra E. , de Jong Krijn P. , Roeffaers Maarten B. J.
Published: August 2017

Incipient wetness impregnation is used commonly to form supported metal nanoparticle catalysts. Recently, it has been revealed that this approach may induce severe heterogeneity between catalyst granules of the same batch. At least a 10‐fold variation in metal loading was observed, which affect the catalytic performance of individual catalyst granules severely. However, the origin of this heterogeneity is still unclear. Here we show that every elementary step in the preparation procedure of a Ag on silica catalyst has an effect on the resulting interparticle heterogeneity, but the influence of the drying step is the most important. This is because drying by capillary force results in a heterogeneous sample. Specifically, the position of a granule in the stagnant drying bed influences the resulting color and, thus, Ag loading significantly. This is further demonstrated by varying the drying conditions: freeze‐drying and fluidized‐bed drying led to a more homogeneous Ag loading. An investigation of the fluidized‐bed‐dried sample by using optical microscopy revealed a large fraction of transparent granules (94 %), which indicates that almost all the Ag nanoparticles in this sample are confined within the 6 nm pores. The optimized supported Ag on silica catalyst shows a good catalytic performance. This adaptation of the drying step can be implemented easily on a laboratory scale, is scalable, and does not require the use of expensive solvents or metal precursors.
Improvement in the Energy Density of Na3V2(PO4)3 by Mg Substitution
Authors: Inoishi Atsushi , Yoshioka Yuto , Zhao Liwei , Kitajou Ayuko , Okada Shigeto
Published: August 2017

Na3V2(PO4)3, with a NASICON‐type structure, is a promising cathode material for use in sodium‐ion batteries based on a two‐electron reaction and operating at 3.4 V. Herein, we report the synthesis of Na3+xV2‐xMgx(PO4)3 (x=0.1 to 0.7) for use as a cathode material in sodium‐ion batteries. In this work, Na3.2V1.8Mg0.2(PO4)3 was found to exhibit a larger reversible capacity than the theoretical capacity of undoped Na3V2(PO4)3, as a result of the larger number of Na+ in the initial composition, as well as access to the V4+/V5+ redox couple. In contrast, although Mg‐rich samples such as Na3.5V1.5Mg0.5(PO4)3 showed a relatively clear plateau for the V4+/V5+ redox couple, the total discharge capacities were lower than that of the undoped Na3V2(PO4)3 because of the irreversibility in the V4+/V5+ redox region. ICP data clearly indicated that Mg2+ are stable within the NASICON structure during redox cycling and that Na+ is the charge carriers in this cathode.
Individualization and Stabilization of Zinc Oxide Nanorods by Covalent Functionalization with Positively Charged Catechol Derivatives
Authors: Burger Alexandra , Srikantharajah Rubitha , Peukert Wolfgang , Hirsch Andreas
Published: August 2017

We present the formation of individualized and stabilized zinc oxide (ZnO) nanorods by functionalization with positively charged catechol derivatives by means of ligand exchange reactions. The electrosteric stabilization of ZnO nanorods was studied using two catechol derivatives, introducing either three (1) or six (2) pH independent positive charges per molecule and sterically demanding groups onto the surface. ZnO nanorods providing initially acetate (Ac) or 2‐[2‐(2‐methoxyethoxy)‐ethoxy]acetic acid (TODA) ligands on their surface were used. The ligand exchange was performed by using mono and mixed functionalization approaches, utilizing either exclusively the positively charged catechols or mixtures of the latter with small commercially available catechol derivatives, namely 4‐methylcatechol (Me‐cat), 4‐tert‐butylcatechol (tBu‐cat), and dopamine hydrochloride (Dop). Using a combination of various analytical methods such as zeta potential, dynamic light scattering (DLS), UV/Vis, and scanning electron microscopy (SEM) measurements we found that the initial surfactants on the nanorods surface, the number of positive charges per molecule, the steric demand, and the added amount of the catechol derivative strongly influence the colloidal behavior of the nanorods. Stable suspensions containing individualized ZnO nanorods were successfully formed upon functionalization of ZnO‐TODA nanorods with 30 monolayers (MLs) of the higher charged catechol (2), as well as using mixtures of 20/10 and 18/10 MLs of 2/Dop.
An Efficient Route to Highly Substituted Indoles via Tetrahydroindol‐4(5H)‐one Intermediates Produced by Ring‐Opening Cyclization of Spirocyclopropanes with Amines
Authors: Nambu Hisanori , Hirota Wataru , Fukumoto Masahiro , Tamura Takafumi , Yakura Takayuki
Published: August 2017

An efficient route to highly substituted indoles was developed. It included regioselective functionalization of tetrahydroindol‐4(5H)‐ones, prepared by ring‐opening cyclization of cyclohexane‐1,3‐dione‐2‐spirocyclopropanes with primary amines, and subsequent oxidation. The 6‐substituted indoles were synthesized from a readily available 5‐substituted cyclohexane‐1,3‐dione‐2‐spirocyclopropane. The synthesis of 5‐ and 7‐substituted indoles was achieved by regioselective electrophilic alkylation of tetrahydroindol‐4(5H)‐one, followed by oxidation. The 4‐substituted indoles were synthesized by nucleophilic alkylation of the corresponding pyrrole derivative, which was prepared by partial oxidation of tetrahydroindol‐4(5H)‐one, and sequential oxidation. The synthesis of 4‐substituted indoles was also accomplished by palladium‐catalyzed coupling of 4‐hydroxyindole‐derived triflates. Furthermore, the synthesis of 4,5,6,7‐tetrasubstituted indoles was achieved by using these regioselective alkylations.
Recent Advances in GLP‐1 Receptor Agonists for Use in Diabetes Mellitus
Authors: McBrayer Dominic N. , Tal‐Gan Yftah
Published: August 2017

Preclinical Research

Mimetics of Glucagon‐like peptide 1 (GLP‐1) represent a useful alternative or complementary treatment choice to insulin in the treatment of diabetes mellitus. The lack of hypoglycemia as a side effect when GLP‐1 receptor agonists are used along with the tendency of these therapeutic agents to prevent or even reduce weight gain makes them valuable targets in therapy development. However, native GLP‐1 and many of its early analogues have very short half‐lives, requiring repeated treatment to maintain therapeutic levels. As all current treatments are injected subcutaneously, a large focus has been made on trying to extend the half‐lives of GLP‐1 analogues while retaining bioactivity. Most success in this regard has been achieved with the use of peptide‐protein fusions, which are not as well suited for oral administration. However, recent work focused on the development of non‐fusion peptides with increased half‐lives that may be more appropriate for oral administration. This minireview discusses the structural characteristics of past and present analogues as well as the recent work conducted toward developing novel GLP‐1 receptor agonists. Drug Dev Res 78 : 292–299, 2017. © 2017 Wiley Periodicals, Inc.
Mixture effects of copper, cadmium, and zinc on mortality and behavior of Caenorhabditis elegans
Authors: Moyson Sofie , Vissenberg Kris , Fransen Erik , Blust Ronny , Husson Steven J.
Published: August 2017

The toxicity effects of zinc (Zn), copper (Cu), and cadmium (Cd), both as single metals and in combination, were examined in the nematode Caenorhabditis elegans. Metal effects on lethality were analyzed in a time-dependent manner using different concentrations in K-medium. To investigate the effects on locomotion and chemosensation, lethal concentration at 20% (LC20) values were used. The results showed that Cu toxicity was higher compared with Cd and Zn, resulting in higher mortality rates and a more reduced locomotion. Lethality increased over time for all metals. When Cd was added to Cu, and vice versa, significant increases in toxicity were noted. Different interaction effects were observed for the mixtures ZnCd, ZnCu, CuCd, and ZnCuCd. Zinc seemed to have a neutral toxic effect on Cd, while in combination with Cu, a similar additive effect was seen as for the CuCd combination. Binary and tertiary metal mixtures caused a strong decrease in locomotion, except for the ZnCd combination, where Zn seemed to have a neutral effect. After LC2024 h exposure, reduced crawling speed (except for Zn) and reduced thrashing behavior (except for Zn and the ZnCd mixture) were observed. Almost no significant effects were observed on chemosensation. Because the same trend of mixture effects was noted in locomotion and in lethality tests, locomotion can probably be considered a sensitive endpoint for metal toxicities. Environ Toxicol Chem 2018;37:145–159. © 2017 SETAC
Predicting US bank failures: A comparison of logit and data mining models
Authors: Jing Zhongbo , Fang Yi
Published: August 2017

Predicting bank failures is important as it enables bank regulators to take timely actions to prevent bank failures or reduce the cost of rescuing banks. This paper compares the logit model and data mining models in the prediction of bank failures in the USA between 2002 and 2010 using levels and rates of change of 16 financial ratios based on a cross‐section sample. The models are estimated for the in‐sample period 2002–2009, while data for the year 2010 are used for out‐of‐sample tests. The results suggest that the logit model predicts bank failures in‐sample less precisely than data mining models, but produces fewer missed failures and false alarms out‐of‐sample.
Control System Design of Power Tracking for PEM Fuel Cell Automotive Application
Authors: Chen F. X. , Yu Y. , Chen J. X.
Published: August 2017

Owing to load variations, the power tracking of fuel cells in automotive applications is emphasized. We address the control strategies to meet varying power demands while optimizing system efficiency. Based on the control‐oriented proton exchange membrane fuel cell model, the relative gain array is analyzed to determine variable parings in control design. As the dynamics of two control variables are different, a cascade control architecture is adopted. A feedforward‐feedback composite control is used to achieve fast response and eliminate the stable error. To avoid oxygen starvation at power transients, an oxygen excess ratio constrained strategy is proposed to limit the load current if there is lack of reaction oxygen. A mixed‐sensitivity synthesis is applied to suppress parameter perturbation and improve system robustness. To further suppress the fluctuations of the oxygen excess ratio and achieve the maximum system efficiency, an oxygen excess ratio invariant strategy is developed, which coordinates load current with airflow. A comparative study is conducted, with two scenarios of power tracking and fuel cell degradation. The results show that the mixed‐sensitivity strategy has a fast response in power tracking and effective perturbation suppression performance, while the oxygen excess ratio invariant strategy maximizes the system efficiency.
A sequential Monte Carlo approach to inference in multiple‐equation Markov‐switching models
Authors: Bognanni Mark , Herbst Edward
Published: August 2017

Vector autoregressions with Markov‐switching parameters (MS‐VARs) offer substantial gains in data fit over VARs with constant parameters. However, Bayesian inference for MS‐VARs has remained challenging, impeding their uptake for empirical applications. We show that sequential Monte Carlo (SMC) estimators can accurately estimate MS‐VAR posteriors. Relative to multi‐step, model‐specific MCMC routines, SMC has the advantages of generality, parallelizability, and freedom from reliance on particular analytical relationships between prior and likelihood. We use SMC's flexibility to demonstrate that model selection among MS‐VARs can be highly sensitive to the choice of prior.
Binary response panel data models with sample selection and self‐selection
Authors: Semykina Anastasia , Wooldridge Jeffrey M.
Published: August 2017

We consider estimating binary response models on an unbalanced panel, where the outcome of the dependent variable may be missing due to nonrandom selection, or there is self‐selection into a treatment. In the present paper, we first consider estimation of sample selection models and treatment effects using a fully parametric approach, where the error distribution is assumed to be normal in both primary and selection equations. Arbitrary time dependence in errors is permitted. Estimation of both coefficients and partial effects, as well as tests for selection bias, are discussed. Furthermore, we consider a semiparametric estimator of binary response panel data models with sample selection that is robust to a variety of error distributions. The estimator employs a control function approach to account for endogenous selection and permits consistent estimation of scaled coefficients and relative effects.
A Full Regioselective and Stereoselective Synthesis of 4‐Nitroisoxazolidines via Stepwise [3 + 2] Cycloaddition Reactions between (Z)‐C‐(9‐Anthryl)‐N‐arylnitrones and (E)‐3,3,3‐Trichloro‐1‐nitroprop‐1‐ene: Comprehensive Experimental and Theoretical Study
Authors: Jasiński Radomir , Żmigrodzka Magdalena , Dresler Ewa , Kula Karolina
Published: August 2017

In the contrast to all known [3 + 2] cycloadditions between nitrones and conjugated nitroalkenes, reactions of (E)‐3,3,3‐trichloro‐1‐nitroprop‐1‐ene with (Z)‐C‐(9‐anthryl)‐N‐arylnitrones are proceeding in a fully regioselective and stereoselective manner. Additionally, density functional theory calculations suggest stepwise, zwitterionic mechanism of these cycloadditions.
More than makeup: How Atsoko overcame the challenges of entrepreneurship in Tanzania
Authors: Alon Ilan , Shneor Rotem
Published: August 2017

Africa is an emerging economy with many institutional obstacles that complicate efforts to do business there. These include limited access to capital, a lack of skilled labor, inferior infrastructure, and corruption. The experiences of Marie Englesson, a Swedish entrepreneur, in establishing Atsoko, a thriving cosmetics distribution and retailing firm in Tanzania, offer valuable lessons in addressing those challenges through creativity, dedication, and wise and principled deployment of capital. Securing first mover advantage, establishing early brand identity, providing employee training, offering a basic salary higher than the local standard, rewarding good performance, and focusing on making a positive social impact were all part of her beauty company's formula for success.
Split common fixed point and common null point problem
Authors: Eslamian Mohammad
Published: August 2017

In this paper, we present a new algorithm for solving the split common null point and common fixed point problem, to find a point that belongs to the common element of common zero points of an infinite family of maximal monotone operators and common fixed points of an infinite family of demicontractive mappings such that its image under a linear transformation belongs to the common zero points of another infinite family of maximal monotone operators and its image under another linear transformation belongs to the common fixed point of another infinite family of demicontractive mappings in the image space. We establish strong convergence for the algorithm to find a unique solution of the variational inequality, which is the optimality condition for the minimization problem. As special cases, we shall use our results to study the split equilibrium problems and the split optimization problems.
The influences of the electrode dimension and the dielectric material on the breakdown characteristics of coplanar dielectric barrier discharge in ambient air
Authors: Wu Shuqun , Huang Guowang , Cheng Wenxin , Chen Wen , Hai Bing , Shao Tao , Zhang Chaohai
Published: August 2017

The influences of the angle of the V‐shaped electrode, the interelectrode distance, the thickness and the types of dielectric plate on the breakdown characteristics of air coplanar dielectric barrier discharge are investigated. When the angle of the electrode increases, the ignition voltage surprisingly decreases, while both the discharge current, and plasma area remain constant. With smaller interelectrode distance or thinner dielectric plate, lower ignition voltage is required. However, if either one of the them exceeds the threshold value, the discharge mode transits from steady to stochastic. In addition, the discharge appearance in the case of alumina is visually more diffuse with respect to the cases of mica and quartz, which may be caused by the surface charges with high density.
Magnetically‐actuated drug delivery device (MADDD) for minimally invasive treatment of prostate cancer: An in vivo animal pilot study
Authors: Struss Werner J. , Tan Zheng , Zachkani Payam , Moskalev Igor , Jackson John K. , Shademani Ali , D'Costa Ninadh M. , Raven Peter A. , Frees Sebastian , Chavez‐Munoz Claudia , Chiao Mu , So Alan I.
Published: August 2017

Background

The vast majority of prostate cancer presents clinically localized to the prostate without evidence of metastasis. Currently, there are several modalities available to treat this particular disease. Despite radical prostatectomy demonstrating a modest prostate cancer specific mortality benefit in the PIVOT trial, several novel modalities have emerged to treat localized prostate cancer in patients that are either not eligible for surgery or that prefer an alternative approach.

Methods

Athymic nude mice were subcutaneously inoculated with prostate cancer cells. The mice were divided into four cohorts, one cohort untreated, two cohorts received docetaxel (10 mg/kg) either subcutaneously (SC) or intravenously (IV) and the fourth cohort was treated using the magnetically‐actuated docetaxel delivery device (MADDD), dispensing 1.5 μg of docetaxel per 30 min treatment session. Treatment in all three therapeutic arms (SC, IV, and MADDD) was administered once weekly for 6 weeks. Treatment efficacy was measured once a week according to tumor volume using ultrasound. In addition, calipers were used to assess tumor volume.

Results

Animals implanted with the device demonstrated no signs of distress or discomfort, neither local nor systemic symptoms of inflammation and infection. Using an independent sample t‐test, the tumor growth rate of the treated tumors was significant when compared to the control. Post hoc Tukey HSD test results showed that the mean tumor growth rate of our device cohort was significantly lower than SC and control cohorts. Moreover, IV cohort showed slight reduction in mean tumor growth rates than the ones from the device cohort, however, there was no statistical significance in tumor growth rate between these two cohorts. Furthermore, immunohistochemistry demonstrated an increased cellular apoptosis in the MADDD treated tumors and a decreased proliferation when compared to the other cohorts. In addition, IV cohort showed increased treatment side effects (weight loss) when compared to the device cohort. Finally, MADDD showed minimal expression of CD45 comparable to the control cohort, suggesting no signs of chronic inflammation.

Conclusions

In conclusion, this study showed for the first time that MADDD, clearly suppressed tumor growth in local prostate cancer tumors. This could potentially be a novel clinical treatment approach for localized prostate cancer.
Seven‐year monitoring of pyrethroid resistance in the pollen beetle (Brassicogethes aeneus F.) during implementation of insect resistance management
Authors: Stará Jitka , Kocourek František
Published: August 2017

BACKGROUND

An increase in the spread of pyrethroid resistance in the pollen beetle has been documented in many European countries. Pyrethroid resistance in the pollen beetle in the Czech Republic has been detected using a topical application bioassay. Resistance monitoring has been carried out during the implementation of insect resistance management.

RESULTS

The susceptibilities of nine pollen beetle populations to four pyrethroids in 2009 − 2015 in the Czech Republic are presented in this paper. The highest resistance ratio (RR) values [based on the lethal dose for 50% of the population (LD50)] obtained for deltamethrin, lambda‐cyhalothrin, tau‐fluvalinate and etofenprox were 500, 299, 108 and 66.9, respectively. Pollen beetle mortality after application of deltamethrin or lambda‐cyhalothrin gradually decreased from 2009 to 2013. High cross‐resistance between lambda‐cyhalothrin and deltamethrin and low cross‐resistance between lambda‐cyhalothrin and etofenprox were demonstrated. A kdr mutation known to cause resistance in the pollen beetle was not detected.

CONCLUSION

A high level of resistance was recorded in most of the nine populations of the pollen beetle in 2013. In the following 2 years, a decrease in resistance associated with a population density decrease of the pollen beetle was observed in all nine populations as a result of insect resistance management based on pyrethroid reduction in winter oilseed rape. © 2017 Society of Chemical Industry
Phase Transitions in C:Ni Nanocomposite Templates during Diameter‐Selective CVD Synthesis of SWCNTs
Authors: Krause Matthias , Melkhanova Svetlana , Hübner René , Haluska Miro , Gemming Sibylle
Published: August 2017

Phase transitions in carbon:nickel nanocomposite templates during diameter‐selective CVD synthesis of SWCNTs were studied. While almost conserving their pre‐defined diameter distribution, as‐deposited Ni3C nanoparticles transform into fcc‐NiO during activation in low‐pressure air atmosphere, and are reduced to a mixture of fcc‐Ni and Ni3C under nanotube growth conditions. The first phase transition leads to a substitutional replacement of the protective carbon matrix by a protective oxide layer. The second one reflects competing reduction processes of NiO. A mechanism for the complementary roles of carbon matrix and Ni species in the three‐step CVD synthesis is proposed that includes nanoparticle immobilization, carbon delivery and catalysis of nanotube growth.
The Size Flexibility of Ferritin Nanocage Opens a New Way to Prepare Nanomaterials
Authors: Zhang Shengli , Zang Jiachen , Chen Hai , Li Meiliang , Xu Chuanshan , Zhao Guanghua
Published: August 2017

Ferritins are ubiquitous iron storage proteins where Fe(II) sequestration prevents not only its spontaneous oxidation to Fe(III) but also production of toxic free radicals. Recently, scientists have subverted these nature functions and used ferritin cage structures of nanometer dimensions for encapsulation of guest molecules such as anti‐cancer drugs or bioactive nutrients based on pH induced ferritin disassembly and reassembly property. However, prior to this study, ferritin nanocage was required to disassemble only under harsh pH conditions (≤2.0 or ≥11.0), followed by reassembly at near neutral pH. Such harsh conditions can cause protein or guest molecules damage to a great extent during this pH‐induced unfolding–refolding process. Here, we provide evidence demonstrating that the apoferritin shell is flexible rather than rigid. Indeed, we found that two large complex molecules, uranyl acetate dihydrate and phosphotungstic acid, can reach the cavity of both plant and animal apoferritin followed by mineralization. Moreover, large organic compound such as curcumin and doxorubicin can also be encapsulated within ferritin cavity by its mixing with protein. This strategy will increase the use of ferritin in nanotechnology, and could be also applicable to other shell‐like proteins as templates to prepare nanomaterials.
High‐Stacking‐Density, Superior‐Roughness LDH Bridged with Vertically Aligned Graphene for High‐Performance Asymmetric Supercapacitors
Authors: Guo Wei , Yu Chang , Li Shaofeng , Yang Juan , Liu Zhibin , Zhao Changtai , Huang Huawei , Zhang Mengdi , Han Xiaotong , Niu Yingying , Qiu Jieshan
Published: August 2017

The high‐performance electrode materials with tuned surface and interface structure and functionalities are highly demanded for advanced supercapacitors. A novel strategy is presented to conFigure high‐stacking‐density, superior‐roughness nickel manganese layered double hydroxide (LDH) bridged by vertically aligned graphene (VG) with nickel foam (NF) as the conductive collector, yielding the LDH‐NF@VG hybrids for asymmetric supercapacitors. The VG nanosheets provide numerous electron transfer channels for quick redox reactions, and well‐developed open structure for fast mass transport. Moreover, the high‐stacking‐density LDH grown and assembled on VG nanosheets result in a superior hydrophilicity derived from the tuned nano/microstructures, especially microroughness. Such a high stacking density with abundant active sites and superior wettability can be easily accessed by aqueous electrolytes. Benefitting from the above features, the LDH‐NF@VG can deliver a high capacitance of 2920 F g−1 at a current density of 2 A g−1, and the asymmetric supercapacitor with the LDH‐NF@VG as positive electrode and activated carbon as negative electrode can deliver a high energy density of 56.8 Wh kg−1 at a power density of 260 W kg−1, with a high specific capacitance retention rate of 87% even after 10 000 cycles.
Highly Compressible Integrated Supercapacitor–Piezoresistance‐Sensor System with CNT–PDMS Sponge for Health Monitoring
Authors: Song Yu , Chen Haotian , Su Zongming , Chen Xuexian , Miao Liming , Zhang Jinxin , Cheng Xiaoliang , Zhang Haixia
Published: August 2017

Rapid improvement of wearable electronics stimulates the demands for the matched functional devices and energy storage devices. Meanwhile, wearable microsystem requires every parts possessing high compressibility to accommodate large‐scale mechanical deformations and complex conditions. In this work, a general carbon nanotube–polydimethylsiloxane (CNT–PDMS) sponge electrode is fabricated as the elementary component of the compressible system. CNT–PDMS sponge performs high sensitivity as a piezoresistance sensor, which is capable of detecting stress repeatedly and owns great electrochemical performance as a compressible supercapacitor which maintains stably under compressive strains, respectively. Assembled with the piezoresistance sensor and the compressible supercapacitor, such highly compressible integrated system can power and modulate the low‐power electronic devices reliably. More importantly, attached to the epidermal skin or clothes, it can detect human motions, ranging from speech recognition to breathing record, thus showing feasibility in real‐time health monitor and human–machine interfaces.
In Situ TEM Investigation of ZnO Nanowires during Sodiation and Lithiation Cycling
Authors: Asayesh‐Ardakani Hasti , Yao Wentao , Yuan Yifei , Nie Anmin , Amine Khalil , Lu Jun , Shahbazian‐Yassar Reza
Published: August 2017

The development of sodium‐ion batteries has drawn lots of attention recently due to the low‐cost and eco‐friendly sodium source. However, a fundamental understanding of the sodiation behavior for commonly used electrode materials is still limited. Here, combining in situ transmission electron microscopy, aberration‐corrected scanning transmission electron microscopy, and ex situ battery cycling tests, the lithiation and sodiation behavior of ZnO nanowires is investigated. The findings show a direct correlation between the mechanical behavior of the lithiated/sodiated ZnO nanowires and their electrochemical cyclability. The mechanical brittleness of LiZn and the formation of nanocracks lead to the poor cyclability of Li‐ion batteries with a ZnO anode. However, the sodiated ZnO nanowires show profuse dislocation plasticity. The observed high‐density dislocations offer the sodiated ZnO anode more ductility and subsequently better cyclability than its Li‐ion counterpart. The results reveal the importance of understanding the correlation between mechanical properties of battery electrodes and their cycling abilities.
Inhibitory effect of ucha‐shinki‐hwan on cold‐mediated response in human dermal microvascular endothelial cells
Authors: Lee Kangwook , Cho Sung‐Gook , Lee Gyu Ri , Choi Yu‐Jeong , Go Ho Yeon , Sun Seung‐Ho , Kim Tae‐Hun , Park Jong‐Hyeong , Choi You‐Kyung , Lee Hesol , Jung Ki‐Yong , Song Yun‐Kyung , Jeon Chan‐Yong , Ko Seong Gyu
Published: August 2017

Aim

Raynaud's phenomenon is characterized by prolonged vasoconstriction in cutaneous capillaries on cold stress. RhoA activity would be a therapeutic target for treating Raynaud's phenomenon. A traditional herbal medicine, ucha‐shinki‐hwan, has been used to promote vasodilation, but the biological mechanism of ucha‐shinki‐hwan is still unclear. Thus, we hypothesized that ucha‐shinki‐hwan is able to be used for treatment of Raynaud's phenomenon and that ucha‐shinki‐hwan inhibits cold‐induced vasoconstriction by targeting RhoA GTPase.

Methods

Human dermal microvascular endothelial cells were pretreated with ucha‐shinki‐hwan for 30 min, followed by incubation in room temperature (37 ± 2°C) or a lower temperature (25 ± 2°C) for 30 min. Expression of active RhoA was measured on western blot. Endothelin‐1 and nitric oxide production were examined on enzyme‐linked immunosorbent assay. The formation of stress fiber and focal adhesion complex was analyzed using immunocytochemistry.

Results

Cold exposure activated RhoA GTPase whereas ucha‐shinki‐hwan treatment suppressed its activation in human dermal microvascular endothelial cells. Moreover, ucha‐shinki‐hwan decreased cold‐induced endothelin‐1 and nitric oxide production. In addition, ucha‐shinki‐hwan treatment inhibited the formation of stress fiber and focal adhesion complex with downregulation of focal adhesion kinase (FAK), SRC kinase and extracellular regulated kinases (ERK) phosphorylation.

Conclusion

Ucha‐shinki‐hwan inhibits contraction of cold‐exposed human dermal microvascular endothelial cells by targeting RhoA activation. This in vitro study is therefore the first to suggest that ucha‐shinki‐hwan is likely to be effective for inhibiting cold‐induced response in vascular endothelial cells.