bluuebunny/crossref_metadata_2025 huggingface dataset:
Palladium Nanoparticles Immobilized on Magnetic Porous Carbon Derived from ZIF‐67 as Efficient Catalysts for the Semihydrogenation of Phenylacetylene under Extremely Mild Conditions
Authors: Li Xinlin , Zhang Wei , Liu Yansheng , Li Rong
Published: February 2016

A new magnetic porous carbon (MDPC) derived from metal–organic frameworks (MOFs) was synthesized successfully through the direct carbonization of ZIF‐67 crystals and utilized as a support for Pd nanocatalysts. The prepared MDPC not only retains the original morphology of ZIF‐67 crystals but also provides a high surface area and excellent magnetic properties. The designed catalysts (Pd‐MDPC) were tested in the semihydrogenation of phenylacetylene under extremely mild conditions. The Pd nanoparticles are highly dispersed on the MDPC matrix without aggregation and exhibited an excellent catalytic activity and high selectivity toward olefins under mild conditions (25 °C, H2 1 atm). The Pd‐MDPC catalysts were further investigated in the semihydrogenation of several other terminal alkynes. Compared with most traditional carbon materials, such as activated carbon and carbon nanotubes, the MDPC possesses an admirable magnetism so that it could be separated magnetically from the reaction system. Our study indicates that MOF‐derived porous carbon is a suitable support for noble‐metal nanocatalysts and has promise in the field of nanocatalysis.
Mechanochemical Synthesis of a Carboxylated Carbon Catalyst and Its Application in Cellulose Hydrolysis
Authors: Shrotri Abhijit , Kobayashi Hirokazu , Fukuoka Atsushi
Published: February 2016

A carbon catalyst containing a high density of carboxyl groups was prepared by solvent‐free mechanochemical oxidation of activated carbon by using persulfate salts as the oxidant. The mechanochemical oxidation preferentially oxidized the carbon to introduce carboxyl groups without incorporation of sulfonated groups. The material exhibited hydrophilic behavior and was easily dispersed in water. Upon mix‐milling, the oxidized carbon showed good catalytic activity for the hydrolysis of cellulose, even at a low catalyst loading. Glucose was obtained in 85 % yield from mix‐milled cellulose in the presence of a trace amount of HCl after a reaction time of 20 min.
Superior Catalysts for Oxygen Reduction Reaction Based on Porous Nanostars of a Pt, Pd, or Pt–Pd Alloy Shell Supported on a Gold Core
Authors: Venarusso Luna B. , Bettini Jefferson , Maia Gilberto
Published: February 2016

The aims of this study are to synthesize porous nanostars (PNSs) composed of a Pt, Pd, or Pt–Pd alloy shell supported on a gold core and to demonstrate their improved electrocatalytic activity towards the oxygen reduction reaction (ORR). The catalysts contain homogeneous, porous, star‐shaped, large‐sized structures (50 or 20 nm on average), with a covering pattern of Pt or Pt–Pd alloy nanodendritic particles of up to 5 nm. The synthesized PNS catalysts catalyze the ORR effectively, offering high performance in terms of Pt group metals mass‐specific activity, electrochemically active surface area (ECSA), specific ECSA, and specific activity, with high half‐wave potential values (0.93–0.96 V).
Using the L1norm to select basis set vectors for multivariate calibration and calibration updating
Authors: Shahbazikhah Parviz , Kalivas John H. , Andries Erik , O'Loughlin Trevor
Published: February 2016

With projection based calibration approaches, such as partial least squares (PLS) and principal component regression (PCR), the calibration space is spanned by respective basis vectors (latent vectors). Up to rank k basis vectors are formed wherek ≤ min(m,n) withmandndenoting the number of calibration samples and measured variables. The user needs to decide how many and which respective basis vectors (tuning parameters). To avoid the second issue, basis vectors are selected top‐down starting with the first and sequentially adding until model criteria are satisfied. Ridge regression (RR) avoids the issues by using the full set of basis vectors. Another approach is to select a subset from the total available. The presented work develops a process based on the L1vector norm to select basis vectors. Specifically, the L1norm is used to select singular value decomposition (SVD) basis set vectors for PCR (LPCR). Because PCR, PLS, RR, and others can be expressed as linear combination of the SVD basis vectors, the focus is on selection and comparison using the SVD basis set. Results based on respective tuning parameter selections and weights applied to the SVD basis vectors for LPCR, top‐down PCR, correlation PCR (CPCR), PLS, and RR are compared for calibration and calibration updating using spectroscopic data sets. The methods are found to predict equivalently. In particular, the L1norm produces similar results to those obtained by the well‐studied CPCR process. Thus, the new method provides a different theoretical framework than CPCR for selecting basis vectors. Copyright © 2016 John Wiley & Sons, Ltd.
Classification of tRNA isoacceptor sequences by using graph‐based molecular descriptors
Authors: Ari Eszter , Jakó Éena
Published: February 2016

A discrete mathematical method, Boolean analysis (or BOOL‐AN), was used for evaluating of functional relationships within and between the families of transfer RNA sequences. The binary encoded sequence information of each transfer RNA was transformed into a compact analytical form, called the Iterative Canonical Form (ICF) of Boolean functions. This canonical form can also be represented as a non‐complete bipartite graph and used then as a generalized molecular descriptor. What is important ICF graphs can be derived without restrictions concerning the number of nodes. Besides, the proposed molecular descriptors are unique, compact, and complete, allowing sequence reconstruction without loss of information. The method provides raw vector data for calculating distance matrices by using different metrics. In turn, the calculated distances can be analyzed by neighbor‐joining or by unweighted pair group method to derive a tree, or by principal coordinates analysis to obtain a multidimensional scaling plot. The ability to arrange the functionally identical tRNA isoacceptors into exclusive groups, reflecting the relationships between 22 tRNA sets with different amino acid specificities, was tested on tRNA genes of Escherichia coli. Performance of the BOOL‐AN was compared with other methods, including standard phylogenetic approaches and distance calculations, based on DNA sequences and chemical indices. The results of classification are represented by trees. We conclude that ICF‐graph distance calculations and the BOOL‐AN software were able to derive the most consistent tree for tRNA isoacceptors in comparison with other methods. Copyright © 2016 John Wiley & Sons, Ltd.
Anion Sensors as Logic Gates: A Close Encounter?
Authors: Madhuprasad  , Bhat Mahesh P. , Jung Ho‐Young , Losic Dusan , Kurkuri Mahaveer D.
Published: February 2016

Computers have become smarter, smaller, and more efficient due to the downscaling of silicon‐based components. Top‐down miniaturisation of silicon‐based computer components is fast reaching its limitations because of physical constraints and economical non‐feasibility. Therefore, the possibility of a bottom‐up approach that uses molecules to build nano‐sized devices has been initiated. As a result, molecular logic gates based on chemical inputs and measurable optical outputs have captured significant attention very recently. In addition, it would be interesting if such molecular logic gates could be developed by making use of ion sensors, which can give significantly sensitive output information. This review provides a brief introduction to anion receptors, molecular logic gates, a comprehensive review on describing recent advances and progress on development of ion receptors for molecular logic gates, and a brief idea about the application of molecular logic gates.
Monosaccharides as Versatile Units for Water‐Soluble Supramolecular Polymers
Authors: Leenders Christianus M. A. , Jansen Gijs , Frissen Martijn M. M. , Lafleur René P. M. , Voets Ilja K. , Palmans Anja R. A. , Meijer E. W.
Published: February 2016

We introduce monosaccharides as versatile water‐soluble units to compatibilise supramolecular polymers based on the benzene‐1,3,5‐tricarboxamide (BTA) moiety with water. A library of monosaccharide‐based BTAs is evaluated, varying the length of the alkyl chain (hexyl, octyl, decyl and dodecyl) separating the BTA and saccharide units, as well as the saccharide units (α‐glucose, β‐glucose, α‐mannose and α‐galactose). In all cases, the monosaccharides impart excellent water compatibility. The length of the alkyl chain is the determining factor to obtain either long, one‐dimensional supramolecular polymers (dodecyl spacer), small aggregates (decyl spacer) or molecularly dissolved (octyl and hexyl) BTAs in water. For the BTAs comprising a dodecyl spacer, our results suggest that a cooperative self‐assembly process is operative and that the introduction of different monosaccharides does not significantly change the self‐ assembly behaviour. Finally, we investigate the potential of post‐assembly functionalisation of the formed supramolecular polymers by taking advantage of dynamic covalent bond formation between the monosaccharides and benzoxaboroles. We observe that the supramolecular polymers readily react with a fluorescent benzoxaborole derivative permitting imaging of these dynamic complexes by confocal fluorescence microscopy.
Alkaline Earth Metal Zirconate Perovskites MZrO3 (M=Ba2+, Sr2+, Ca2+) Derived from Molecular Precursors and Doped with Eu3+ Ions
Authors: Drąg‐Jarząbek Anna , John Łukasz , Petrus Rafał , Kosińska‐Klähn Magdalena , Sobota Piotr
Published: February 2016

The effect of alkaline earth metal alkoxides on the protonation of zirconocene dichloride was investigated. This approach enabled the design of compounds with preset molecular structures for generating high‐purity binary metal oxide perovskites MZrO3 (M=Ba2+, Sr2+, Ca2+). Single‐source molecular precursors [Ba4Zr2(μ6‐O)(μ3,η2‐OR)8(OR)2(η2‐HOR)2(HOR)2Cl4], [Sr4Zr2(μ6‐O)(μ3,η2‐OR)8(OR)2(HOR)4Cl4], [Ca4Zr2(μ6‐O)(μ3,η2‐OR)8(OR)2Cl4], and [Ca6Zr2(μ2,η2‐OR)12(μ‐Cl)2(η2‐HOR)4Cl6]⋅8 CH2Cl2 were prepared via elimination of the cyclopentadienyl ring from Cp2ZrCl2 as CpH in the presence of M(OR)2 and alcohol ROH (ROH=CH3OCH2CH2OH) as a source of protons. The resulting complexes were characterized by elemental analysis, IR and NMR spectroscopy, and single‐crystal X‐ray diffraction. The compounds were then thermally decomposed to MCl2/MZrO3 mixtures. Leaching of MCl2 from the raw powder with deionized water produced highly pure perovskite‐like oxide particles of 40–80 nm in size. Luminescence studies on Eu3+‐doped MZrO3 revealed that the perovskites are attractive host lattices for potential applications in display technology.
Effect of Structural Modifications on the Self‐Assembly of Oligoprolines Conjugated with Sterically Demanding Chromophores
Authors: Lewandowska Urszula , Zajaczkowski Wojciech , Pisula Wojciech , Ma Yingjie , Li Chen , Müllen Klaus , Wennemers Helma
Published: February 2016

Conjugates between oligoprolines and sterically demanding perylene monoimides (PMIs) form hierarchical supramolecular self‐assemblies. The influence of the length and stereochemistry at the attachment site between the peptide backbone and the chromophore on the self‐assembly properties of the conjugates was explored. Comparison between oligoprolines bearing 4R‐ or 4S‐configured azidoprolines (Azp) for the conjugation with the PMIs revealed that diastereoisomers with 4R configuration guide the self‐assembly consistently better than conjugates with 4S configuration. Elongating the peptide chain beyond nine proline residues or introducing structural “errors”, by altering the absolute configuration of one stereogenic center at the outside of the functionalizable oligoproline helix, lowered the efficacy of self‐assembly significantly, both in solution phase and in the solid state. The results showed how subtle structural modifications allow for tuning the self‐assembly of chromophores and provided further design principles for the development of peptide–chromophore conjugates into nanostructured materials.
Insight into the Reaction of a Dinuclear Phosphinidene Complex with Nitriles
Authors: Seidl Michael , Weinzierl Rudolf , Timoshkin Alexey Y. , Scheer Manfred
Published: February 2016

The phosphinidene complex [Cp*P{W(CO)5}2] (1; Cp*=C5Me5) reacted with malononitrile to give the 1,2‐dihydro‐1,3,2‐diazaphosphinine derivative 2. The reaction of 1 with 1,4‐benzodinitrile gave [1,4‐{{W(CO)5}2P‐N=C(Cp*)}2(C6H4)] (3), the first example of a cumulene‐like aminophosphinidene complex. The reaction of 1 with aniline gave the aminophosphinidene complex [(Ph)N(H)P{W(CO)5}2] (4). To compare the reactivity of benzonitrile and aniline with 1, the phosphinidene complex 1 was reacted with three different isomers of aminobenzonitrile (2‐, 3‐, and 4‐aminobenzonitrile). These reactions gave an insight into the reaction pathway of 1 with benzonitrile derivatives. Compounds 5, 6 a, 6 b, and 7, which are derivatives of 1,2‐dihydro‐1,3,2‐diazaphosphinine or benzo‐2H‐1,2‐azaphospholes, were, as well as all other products, characterized by mass spectrometry, NMR and IR spectroscopy, and X‐ray structure analysis.
Production of Metal‐Free Composites Composed of Graphite Oxide and Oxidized Carbon Nitride Nanodots and Their Enhanced Photocatalytic Performances
Authors: Kim Seung Yeon , Oh Junghoon , Park Sunghee , Shim Yeonjun , Park Sungjin
Published: February 2016

A novel metal‐free composite (GN) composed of two types of carbon‐based nanomaterials, graphite oxide (GO) and 2D oxidized carbon nitride (OCN) nanodots was produced. Chemical and morphological characterizations reveal that GN contains a main component of GO with well‐dispersed 2D OCN nanodots. GN shows enhanced photocatalytic performance for degrading an organic pollutant, Rhodamine B, under visible light.
Carbon‐Coated Hierarchical SnO2 Hollow Spheres for Lithium Ion Batteries
Authors: Liu Qiannan , Dou Yuhai , Ruan Boyang , Sun Ziqi , Chou Shu‐Lei , Dou Shi Xue
Published: February 2016

Hierarchical SnO2 hollow spheres self‐assembled from nanosheets were prepared with and without carbon coating. The combination of nanosized architecture, hollow structure, and a conductive carbon layer endows the SnO2‐based anode with improved specific capacity and cycling stability, making it more promising for use in lithium ion batteries.
Effects of Crops on Runoff and Soil Loss on Sloping Farmland Under Simulated Rainfall
Authors: Ma Bo , Li Chaodong , Li Zhanbin , Wu Faqi
Published: February 2016

Crops are the most important sloping farmland cover. Runoff plot experiments were conducted to study soil erosion from a 10° gradient with different growth stage of corn and soybean by simulated rainfall. The results showed that compared with the bare slope, corn plants could averagely reduce 24% runoff and 47% soil loss and soybean plants could averagely reduce 31% runoff and 55% soil loss. With crop growth, runoff and sediment yield on the slope covered by crops decreased gradually and the fluctuation in the production process of runoff and sediment decreased and tended to be stabilized. On the slope covered by corns, runoff rate, sediment yield, and sediment concentration showed the negatively linear functional relationship with leaf area index. Under soybean coverage conditions, slope runoff showed the logarithmic functional relationship with leaf area index, while sediment yield and sediment concentration showed the exponential relationship with leaf area index. Under corn coverage conditions, soil loss ratio was 0.53 on average and showed the linear functional relationship with leaf area index. Under soybean coverage conditions, soil loss ratio was averaged 0.46 and showed the exponential functional relationship with leaf area index. Crops showed strong inhibitory effects on soil erosion and the effect on sediment interception was more significant than the effect on runoff impoundment. Soybean showed more significant effects on sediment interception and runoff impoundment than corn.
Stability properties of neuronal microtubules
Authors: Baas Peter W. , Rao Anand N. , Matamoros Andrew J. , Leo Lanfranco
Published: February 2016

Neurons are terminally differentiated cells that use their microtubule arrays not for cell division but rather as architectural elements required for the elaboration of elongated axons and dendrites. In addition to acting as compression‐bearing struts that provide for the shape of the neuron, microtubules also act as directional railways for organelle transport. The stability properties of neuronal microtubules are commonly discussed in the biomedical literature as crucial to the development and maintenance of the nervous system, and have recently gained attention as central to the etiology of neurodegenerative diseases. Drugs that affect microtubule stability are currently under investigation as potential therapies for disease and injury of the nervous system. There is often a lack of consistency, however, in how the issue of microtubule stability is discussed in the literature, and this can affect the design and interpretation of experiments as well as potential therapeutic regimens. Neuronal microtubules are considered to be more stable than microtubules in dividing cells. On average, this is true, but in addition to an abundant stable microtubule fraction in neurons, there is also an abundant labile microtubule fraction. Both are functionally important. Individual microtubules consist of domains that differ in their stability properties, and these domains can also differ markedly in their composition as well as how they interact with various microtubule‐related proteins in the neuron. Myriad proteins and pathways have been discussed as potential contributors to microtubule stability in neurons. © 2016 Wiley Periodicals, Inc.
Modeling cytokinesis of eukaryotic cells driven by the actomyosin contractile ring
Authors: Zhao Jia , Wang Qi
Published: February 2016

A three‐dimensional (3D) hydrodynamic model for cytokinesis of eukaryotic cells is developed, in which we model dynamics of actomyosins in the cell cortex, in particular, along the cytokinetic ring formed in the cortex and in the neighborhood of the cell's division plane explicitly. Specifically, the active force actuated by the actomyosin's activity along the cytokinetic ring is modeled by a surface force whose strength is proportional to the actomyosin concentration while the cell morphology is tracked by a phase field model. The model is then solved in 3D space and time using a finite difference method on graphic processing units. Dynamical morphological patterns of eukaryotic cells during cytokinesis are numerically simulated with the model. These simulated morphological patterns agree quantitatively with experimental observations. Copyright © 2016 John Wiley & Sons, Ltd.
Speciation and Structural Properties of Hydrothermal Solutions of Sodium and Potassium Sulfate Studied by Molecular Dynamics Simulations
Authors: Reimer Joachim , Vogel Frédéric , Steele‐MacInnis Matthew
Published: February 2016

Aqueous solutions of salts at elevated pressures and temperatures play a key role in geochemical processes and in applications of supercritical water in waste and biomass treatment, for which salt management is crucial for performance. A major question in predicting salt behavior in such processes is how different salts affect the phase equilibria. Herein, molecular dynamics (MD) simulations are used to investigate molecular‐scale structures of solutions of sodium and/or potassium sulfate, which show contrasting macroscopic behavior. Solutions of Na−SO4 exhibit a tendency towards forming large ionic clusters with increasing temperature, whereas solutions of K−SO4 show significantly less clustering under equivalent conditions. In mixed systems (NaxK2−xSO4), cluster formation is dramatically reduced with decreasing Na/(K+Na) ratio; this indicates a structure‐breaking role of K. MD results allow these phenomena to be related to the characteristics of electrostatic interactions between K+ and SO42−, compared with the analogous Na+−SO42− interactions. The results suggest a mechanism underlying the experimentally observed increasing solubility in ternary mixtures of solutions of Na−K−SO4. Specifically, the propensity of sodium to associate with sulfate, versus that of potassium to break up the sodium–sulfate clusters, may affect the contrasting behavior of these salts. Thus, mutual salting‐in in ternary hydrothermal solutions of Na−K−SO4 reflects the opposing, but complementary, natures of Na−SO4 versus K−SO4 interactions. The results also provide clues towards the reported liquid immiscibility in this ternary system.
The effect of prey refuge and time delay on a diffusive predator‐prey system with hyperbolic mortality
Authors: Yang Ruizhi , Zhang Chunrui
Published: February 2016

In this article, we investigate the effect of prey refuge and time delay on a diffusive predator‐prey system with Holling II functional response and hyperbolic mortality subject to Neumann boundary condition. More precisely, we study Turing instability of positive equilibrium by using refuge as parameter, instability and Hopf bifurcation induced by time delay. In addition, by the theory of normal form and center manifold, we derive conditions for determining the bifurcation direction and the stability of the bifurcating periodic solution. © 2016 Wiley Periodicals, Inc. Complexity 21: 446–459, 2016
Feasibility and Effects of a Brief Compassion‐Focused Imagery Intervention in Psychotic Patients with Paranoid Ideation: A Randomized Experimental Pilot Study
Authors: Ascone Leonie , Sundag Johanna , Schlier Björn , Lincoln Tania M.
Published: February 2016

Paranoia is characterized by a lack of perceived social safeness and associated negative affect. Low self‐esteem, negative self‐concepts and negative emotions have been shown to contribute to paranoid symptom formation. Thus, interventions focusing on affiliation and positive affect might be particularly helpful for patients with paranoia. The present study experimentally tested the effect of a one‐session, brief compassion‐focused imagery derived from Compassion‐Focused Therapy (Gilbert, ) versus a control imagery condition in a repeated measures randomized design. A negative affective state was induced via in‐sensu exposure to a recent distressful social situation in order to provide a minimum level of threat‐related arousal to be down‐regulated by the interventions thereafter. The sample consisted of psychotic patients with paranoid ideation (N = 51) who were randomly assigned to one of the experimental conditions. Effects on postulated causal mechanisms, i.e., self‐relating (self‐reassurance, self‐compassion, self‐criticism), and affect (self‐reported affective states, skin conductance levels) as well as on state paranoia, were tested. Subjective benefit and appraisals of the intervention were explored. There were no specific intervention effects on negative self‐relating, negative affect and skin‐conductance or on paranoia. However, compassion‐focused imagery had significant effects on self‐reassurance and happiness. Explorative analyses revealed that the majority of the participants appraised the intervention in a positive manner, indicating good acceptance. The intervention showed an effect on some of the postulated mechanisms but not on others, which might have been because of its brevity. Further investigation of interventions targeting affiliation for people with paranoid experiences appears worthwhile. Copyright © 2016 John Wiley & Sons, Ltd.

Key Practitioner Message

Affiliative imagery work is feasible and appraised positively in psychotic patients.

Brief compassion focused imagery increased feelings of happiness and reassurance but did not improve negative self‐relating, negative affect or paranoia.

Further investigation is warranted to identify which patients benefit most from affiliative imagery.
Electrochemical Reduction of Carbon Dioxide to Methanol by Direct Injection of Electrons into Immobilized Enzymes on a Modified Electrode
Authors: Schlager Stefanie , Dumitru Liviu Mihai , Haberbauer Marianne , Fuchsbauer Anita , Neugebauer Helmut , Hiemetsberger Daniela , Wagner Annika , Portenkirchner Engelbert , Sariciftci Niyazi Serdar
Published: February 2016

We present results for direct bio‐electrocatalytic reduction of CO2 to C1 products using electrodes with immobilized enzymes. Enzymatic reduction reactions are well known from biological systems where CO2 is selectively reduced to formate, formaldehyde, or methanol at room temperature and ambient pressure. In the past, the use of such enzymatic reductions for CO2 was limited due to the necessity of a sacrificial co‐enzyme, such as nicotinamide adenine dinucleotide (NADH), to supply electrons and the hydrogen equivalent. The method reported here in this paper operates without the co‐enzyme NADH by directly injecting electrons from electrodes into immobilized enzymes. We demonstrate the immobilization of formate, formaldehyde, and alcohol dehydrogenases on one‐and‐the‐same electrode for direct CO2 reduction. Carbon felt is used as working electrode material. An alginate–silicate hybrid gel matrix is used for the immobilization of the enzymes on the electrode. Generation of methanol is observed for the six‐electron reduction with Faradaic efficiencies of around 10 %. This method of immobilization of enzymes on electrodes offers the opportunity for electrochemical application of enzymatic electrodes to many reactions in which a substitution of the expensive sacrificial co‐enzyme NADH is desired.
Association between intestinal permeability and faecal microbiota composition in Italian children with beta cell autoimmunity at risk for type 1 diabetes
Authors: Maffeis Claudio , Martina Alessia , Corradi Massimiliano , Quarella Sara , Nori Nicole , Torriani Sandra , Plebani Mario , Contreas Giovanna , Felis Giovanna E.
Published: February 2016

Background

Pancreatic organ‐specific autoimmunity in subjects at risk for type 1 diabetes (T1D) is associated with increased intestinal permeability and an aberrant gut microbiota, but these factors have not yet been simultaneously investigated in the same subjects. Thus, the aim of this study was to assess both intestinal permeability and gut microbiota composition in an Italian sample of children at risk for T1D.

Methods

Ten Italian children with beta cell autoimmunity at risk for T1D and 10 healthy children were involved in a case–control study. The lactulose/mannitol test was used to assess intestinal permeability. Analysis of microbiota composition was performed using polymerase chain reaction followed by denaturing gradient gel electrophoresis, based on the 16S rRNA gene.

Results

Intestinal permeability was significantly higher in children at risk for T1D than in healthy controls. Moreover, the gut microbiota of the former differed from that of the latter group: Three microorganisms were detected – Dialister invisus, Gemella sanguinis and Bifidobacterium longum – in association with the pre‐pathologic state.

Conclusions

The results of this study validated the hypothesis that increased intestinal permeability together with differences in microbiota composition are contemporaneously associated with the pre‐pathological condition of T1D in a sample of Italian children. Further studies are necessary to confirm the microbial markers identified in this sample of children as well as to clarify the involvement of microbiota modifications in the mechanisms leading to increased permeability and the autoimmune mechanisms that promote diabetes onset. Copyright © 2016 John Wiley & Sons, Ltd.
Screening for illicit drugs in pooled human urine and urinated soil samples and studies on the stability of urinary excretion products of cocaine, MDMA, and MDEA in wastewater by hyphenated mass spectrometry techniques
Authors: Mardal Marie , Kinyua Juliet , Ramin Pedram , Miserez Bram , Van Nuijs Alexander L. N. , Covaci Adrian , Meyer Markus R.
Published: February 2016

Monitoring population drug use through wastewater‐based epidemiology (WBE) is a useful method to quantitatively follow trends and estimate total drug consumption in communities. Concentrations of drug biomarkers might be low in wastewater due to dilution; and therefore analysis of pooled urine (PU) is useful to detect consumed drugs and identify targets of illicit drugs use. The aims of the study were (1) to screen PU and urinated soil (US) samples collected at festivals for illicit drug excretion products using hyphenated techniques; (2) to develop and validate a hydrophilic interaction liquid chromatography – mass spectrometry / mass spectrometry (HILIC‐MS/MS) method of quantifying urinary targets of identified drugs in wastewater; and (3) to conduct a 24 h stability study, using PU and US to better reflect the chemical environment for targets in wastewater. Cocaine (COC) and ecstasy‐like compounds were the most frequently detected illicit drugs; an analytical method was developed to quantify their excretion products. Hydroxymethoxymethamphetamine (HMMA), 3,4‐methylenedioxymethamphetamine (MDMA), 3,4‐methylenedioxyamphetamine (MDA), HMMA sulfate (HMMA‐S), benzoylecgonine (BE), and cocaethylene (CE) had 85–102% of initial concentration after 8 h of incubation, whereas COC and ecgonine methyl ester (EME) had 74 and 67% after 8 h, respectively. HMMA showed a net increase during 24 h of incubation (107% ± 27, n = 8), possibly due to the cleavage of HMMA conjugates, and biotransformation of MDMA. The results suggest HMMA as analytical target for MDMA consumption in WBE, due to its stability in wastewater and its excretion as the main phase I metabolite of MDMA. Copyright © 2016 John Wiley & Sons, Ltd.
Detection of Damaged Distribution Surge Arresters Using an Impulse Generator
Authors: MATSUURA SUSUMU , SHIMASAKI KATSUHIKO , SUGIMOTO HITOSHI
Published: February 2016

Distribution surge arresters with an internal series gap have been installed on Japanese distribution lines at high density to reduce lightning‐related overvoltages. In contrast, surge arresters are sometimes damaged by direct lightning strokes, particularly in winter. Measurement of the insulation resistance between the terminals of the surge arrester and measurement of the dc discharge voltage of the surge arrester are generally adopted to detect damaged arresters. However, if metal‐oxide (MO) varistors are damaged and the internal series gap is not damaged, it is difficult to detect damaged arresters by the two conventional methods. Therefore, this paper presents a proposed detection method that can accurately detect damaged arresters. In the proposed method, first, the voltage between the terminals of the surge arrester is measured when the output of an impulse generator is applied to the surge arrester. Second, the damaged arrester is detected by comparison between its voltage waveform and the voltage waveform of the nondamaged arrester. The detection rate of damaged arresters by the proposed method is markedly higher than the rates of detection by the two conventional methods.
Partial Discharge Detection with High‐Frequency Band through Resistance–Temperature Sensor of Hydropower Generator Stator Windings
Authors: KANEGAMI MASAKI , MIYAZAKI SATORU , MIYAKE KATSUYUKI
Published: February 2016

In order to improve the signal to noise ratio for partial discharge (PD) detection using a resistance–temperature detector laid in the stator windings of a hydropower generator, the continuous wavelet transform (CWT) is applied as a kind of time‐frequency analysis. Relying on the combination of frequency resolution and time resolution using an applied power voltage phase angle distribution, PDs occurring in voids of stator windings are expected to be found within a mixed environment of strong noise and confusable noise. Furthermore, we found that the CWT may make it possible to calibrate the PD charge quantity in a band of a few tens of MHz under favorable conditions, where calibration is usually difficult for generator stator windings.
In vitro Cytotoxicity of Half‐Sandwich Platinum Group Metal Complexes of a Cationic Alkylated Phosphaadamantane Ligand
Authors: Burgoyne Andrew R. , Kaschula Catherine H. , Parker M. Iqbal , Smith Gregory S.
Published: February 2016

Trinuclear and model mononuclear cationic monodentate RhIII, IrIII and RuII complexes with alkylated 1,3,5‐triaza‐7‐phosphaadamantane (PTA) moieties have been prepared and characterized using NMR and IR spectroscopy, HR‐ESI mass spectrometry and elemental analysis. The metals coordinate to the ligands via the phosphorus of the PTA, and this was confirmed by shifts in the 31P{1H} NMR spectra. The cytotoxicities of all the compounds were investigated against the WHCO1 esophageal cancer cell line. The IrIII mononuclear complex proved to be the most cytotoxic. Additionally, 1H NMR model studies demonstrated its DNA binding ability while UV/Vis studies demonstrated the ability of the iridium mononuclear complex to interact with the double helix structure of Red Salmon testes DNA.
Lewis Acid Catalyzed Synthesis of Cyanidoborates
Authors: Bläsing Kevin , Ellinger Stefan , Harloff Jörg , Schulz Axel , Sievert Katharina , Täschler Christoph , Villinger Alexander , Zur Täschler Cornelia
Published: February 2016

The reactions of [BF4]– salts with Me3SiCN were studied at different temperatures and in the presence of several different Lewis acids, which led to the generation of the well‐known [BF4–n(CN)n]– (n = 1–4) salts. Depending on the catalyst and the reaction conditions, the whole series of [BF4–n(CN)n]– salts is now accessible under ambient conditions, and long preparation times and the excessive production of waste materials can be avoided. The best results were obtained when the F–/CN– substitution reactions were performed in ionic liquids.
Cycloadditions of Sugar‐Derived ­Nitrones Targeting Polyhydroxylated Indolizidines
Authors: Martella Daniele , D'Adamio Giampiero , Parmeggiani Camilla , Cardona Francesca , Moreno‐Clavijo Elena , Robina Inmaculada , Goti Andrea
Published: February 2016

The 1,3 dipolar cycloaddition reactions of three pentose‐derived pyrroline N‐oxides with mono‐ and disubstituted alkenes are reported. A strong dependence of the diastereoselectivity of the cycloadditions on the relative configuration of the nitrone stereocentres was observed. Further transformation of the reaction products allowed the synthesis of four new tetrahydroxylated indolizidines. Their activity as glycosidase inhibitors was evaluated against a panel of commercially available glycosidases. The specificity of inhibitory activity against amyloglucosidase and α‐mannosidases depends on the configuration at C‐2 of the indolizidine moiety.
Direct Synthesis of Enolizable N‐Sulfonyl Ketimines Under Microwave Irradiation
Authors: Pablo Ortiz  , Collados Juan F. , Harutyunyan Syuzanna R.
Published: February 2016

N‐sulfonyl imines are widely used as substrates for a range of transformations. Access to N‐sulfonyl aldimines is straightforward through direct condensation between the parent aldehyde and the sulfonamide. However, this approach is not efficient for the synthesis of enolizable N‐sulfonyl ketimines. Herein we report a rapid and facile methodology for obtaining these products using microwave irradiation.
Azaphosphatranes as Hydrogen‐Bonding Organocatalysts for the Activation of Carbonyl Groups: Investigation of Lactide Ring‐Opening Polymerization
Authors: Zhang Dawei , Jardel Damien , Peruch Frédéric , Calin Nathalie , Dufaud Véronique , Dutasta Jean‐Pierre , Martinez Alexandre , Bibal Brigitte
Published: February 2016

The hydrogen‐bonding activation of C=O bonds by azaphosphatranes was explored in a model reaction, i.e., the ring‐opening polymerization of lactide. The polymerization process was controlled, and allowed the preparation of polylactides with narrow dispersity under mild conditions (20 °C, 24 h, 10 mol‐% catalyst loading). Interestingly, the steric hindrance of azaphosphatranes, as globular rigid structures, prevents any undesired interaction with the tertiary amine cocatalysts, as shown by X‐ray analysis and semi‐empirical calculations. In contrast to their organocatalytic activity in the CO2/epoxide reaction, all of the phosphonium derivatives tested were found to be efficient catalysts in this ROP benchmark reaction.
Electrochemistry on Paper‐based Analytical Devices: A Review
Authors: Mettakoonpitak Jaruwan , Boehle Katherine , Nantaphol Siriwan , Teengam Prinjaporn , Adkins Jaclyn A. , Srisa‐Art Monpichar , Henry Charles S.
Published: February 2016

Even though they were introduced less than a decade ago, electrochemical paper‐based devices (ePADs) have attracted widespread attention because of their inherent advantages in many applications. ePADs combine the advantages of microfluidic paper‐based devices (low cost, ease of use, equipment free pumping, etc.) for sample handling and processing with the advantages of sensitive and selective detection provided by electrochemistry. As a result, ePADs provide simplicity, portability, reproducibility, low cost and high selectivity and sensitivity for analytical measurements in a variety of applications ranging from clinical diagnostics to environmental sensing. Herein, recent advances in ePAD development and application are reviewed, focusing on electrode fabrication techniques and examples of applications specially focused on environmental monitoring, biological applications and clinical assays. Finally, a summary and prospective directions for ePAD research are also provided.
High‐throughput microfluidic device for single cell analysis using multiple integrated soft lithographic pumps
Authors: Patabadige Damith E. W. , Mickleburgh Tom , Ferris Lorin , Brummer Gage , Culbertson Anne H. , Culbertson Christopher T.
Published: February 2016

The ability to accurately control fluid transport in microfluidic devices is key for developing high‐throughput methods for single cell analysis. Making small, reproducible changes to flow rates, however, to optimize lysis and injection using pumps external to the microfluidic device are challenging and time‐consuming. To improve the throughput and increase the number of cells analyzed, we have integrated previously reported micropumps into a microfluidic device that can increase the cell analysis rate to ∼1000 cells/h and operate for over an hour continuously. In order to increase the flow rates sufficiently to handle cells at a higher throughput, three sets of pumps were multiplexed. These pumps are simple, low‐cost, durable, easy to fabricate, and biocompatible. They provide precise control of the flow rate up to 9.2 nL/s. These devices were used to automatically transport, lyse, and electrophoretically separate T‐Lymphocyte cells loaded with Oregon green and 6‐carboxyfluorescein. Peak overlap statistics predicted the number of fully resolved single‐cell electropherograms seen. In addition, there was no change in the average fluorescent dye peak areas indicating that the cells remained intact and the dyes did not leak out of the cells over the 1 h analysis time. The cell lysate peak area distribution followed that expected of an asynchronous steady‐state population of immortalized cells.
Farnesol stimulates laccase production in Trametes versicolor
Authors: Hu Jianhua , Wang Feng , Ma Anzhou , Zhuang Guoqiang , Liu Ying , Lu Jingsong , Guo Chen , Liu Chunzhao
Published: February 2016

Farnesol, a quorum‐sensing molecule, was used successfully to improve laccase production in submerged cultures of Trametes versicolor. At the optimal farnesol concentration of 60 μM added at the beginning of the culture, the extracellular laccase activity reached 629.3 U L−1 after 6 days of cultivation, which represented a 1.92‐fold increase relative to the control without farnesol treatment. The addition of farnesol resulted in an increase in the accumulation of H2O2 and an increased expression of the laccase (lac) gene and the RhoA gene. The RhoA gene correlated with hyperbranched mycelia, which facilitated the secretion of the intracellular laccase. This study provides a basis for understanding the induction mechanism of farnesol for enhancing laccase production.
Rhodosporidium toruloides cultivated in NaCl‐enriched glucose‐based media: Adaptation dynamics and lipid production
Authors: Tchakouteu Sidoine Sadjeu , Kopsahelis Nikolaos , Chatzifragkou Afroditi , Kalantzi Ourania , Stoforos Nikolaos G. , Koutinas Apostolis A. , Aggelis George , Papanikolaou Seraphim
Published: February 2016

In the present report and for the first time in the international literature, the impact of the addition of NaCl upon growth and lipid production on the oleaginous yeast Rhodosporidium toruloides was studied. Moreover, equally for first time, lipid production by R. toruloides was performed under nonaseptic conditions. Therefore, the potentiality of R. toruloides DSM 4444 to produce lipid in media containing several initial concentrations of NaCl with glucose employed as carbon source was studied. Preliminary batch‐flask trials with increasing amounts of NaCl revealed the tolerance of the strain against NaCl content up to 6.0% w/v. However, 4.0% w/v of NaCl stimulated lipid accumulation for this strain, by enhancing lipid production up to 71.3% w/w per dry cell weight. The same amount of NaCl was employed in pasteurized batch‐flask cultures in order to investigate the role of the salt as bacterial inhibiting agent. The combination of NaCl and high glucose concentrations was found to satisfactorily suppress bacterial contamination of R. toruloides cultures under these conditions. Batch‐bioreactor trials of the yeast in the same media with high glucose content (up to 150 g/L) resulted in satisfactory substrate assimilation, with almost linear kinetic profile for lipid production, regardless of the initial glucose concentration imposed. Finally, fed‐batch bioreactor cultures led to the production of 37.2 g/L of biomass, accompanied by 64.5% w/w of lipid yield. Lipid yield per unit of glucose consumed received the very satisfactory value of 0.21 g/g, a value among the highest ones in the literature. The yeast lipid produced contained mainly oleic acid and to lesser extent palmitic and stearic acids, thus constituting a perfect starting material for “second generation” biodiesel.
A novel power control based on a relaxed constraint in cognitive system
Authors: Ridouani Mohammed , Hayar Aawatif , Haqiq Abdelkrim
Published: February 2016

The next‐generation 5G networks will integrate two technologies, cognitive radio and cooperative communication, which use radio spectrum opportunistically and efficiently. In addition, they enhance the reliability and the capacity of the system. In this paper, we present a novel power control scheme based on a relaxed constraint in cognitive network under both the outage probability limit (OPL) of the primary system and the interference constraint limit (ICL). We show how to transform the optimization problem of the condition on the OPL and the ICL into a condition on the channel so that the cognitive user observes the channel from cognitive source to primary receiver and control its transmit power based on the channel condition. Moreover, we extend the studies to the cognitive relay network. We derive the closed‐form expressions of the outage probabilities over independent but not necessarily identically distributed Nakagami‐m fading channels. By using the theoretical analysis and from the numerical results, firstly, we show that the proposed power control scheme, which is based on both the OPL and the ICL, achieves better performance in underlay spectrum rather than the traditional one, which is based only on the interference constraints. Secondly, we show that the proposed scheme allows lower power consumption at cognitive side while the performance of cognitive relay network is improved, and the QoS of primary system is guaranteed in parallel. Copyright © 2016 John Wiley & Sons, Ltd.
Why Do Students Leave Education Early? Theory and Evidence on High School Dropout Rates
Authors: Cabus Sofie J. , De Witte Kristof
Published: February 2016

This paper contributes to the growing literature on school dropout by proposing and empirically testing a theoretical framework on the enrollment decision of youngsters in secondary education. The model relates school dropout to time preferences, motivation, opportunity costs and policy measures. It is empirically tested on longitudinal data of about 4000 Dutch vocational students. We evaluate the enrollment decision of students for (i) different intensity levels of dropout prevention policy, and for (ii) different levels of economic development. The results indicate that the model can accurately predict actual enrollment rates over the period 2000–2013. Copyright © 2016 John Wiley & Sons, Ltd.
Estimating Utility Avoided Costs Without Utility‐Specific Data
Authors: Daniel Joseph
Published: February 2016

In December 2015, the Nevada Public Utility Commission unanimously approved a utility request to charge new fees to customers that have interconnected solar panels to the grid under the utility's net metering tariff. The proceeding—the culmination of months of direct and rebuttal testimony submitted for the commission's consideration in a docket—mirrors dockets being held across the country, though the outcomes have varied in other states.
Clean Power Plan Stayed; Litigation Now at Light Speed
Authors: McGuffey Carroll W. “Mack”
Published: February 2016

As everyone in the power sector should know by now, the Environmental Protection Agency (EPA) issued a big rule—perhaps the biggest ever—last August: the Clean Power Plan. Although hyperbole is common in descriptions of the EPA's recent rulemaking efforts, this is not that. The rule will truly require a dramatic transformation of the electricity system. The EPA's own predictions show that the rule will force coal to retire, gas to struggle, renewables to grow, prices to rise, and electricity demand to fall. And with the biggest rule comes the biggest lawsuit—now attended by 45 states (18 in support of the rule, 27 against) and over a hundred other interested parties seeking to weigh in.
3D seismic structure of the Zhenbei–Huangyan seamounts chain in the East Sub‐basin of the South China Sea and its mechanism of formation
Authors: Wang Jian , Zhao Minghui , Qiu Xuelin , Sibuet Jean‐Claude , He Enyuan , Zhang Jiazheng , Tao Chunhui
Published: February 2016

The probable N055°‐oriented extinct spreading ridge of the East Sub‐basin is cut across by the post‐spreading volcanic ridge oriented approximately E–W in its western part and called the Zhenbei–Huangyan seamounts chain. A three‐dimensional ocean bottom seismometer survey was conducted in 2011 and covered both the extinct spreading ridge and the Zhenbei–Huangyan seamounts chain in the East Sub‐basin. The comprehensive seismic record sections of 39 ocean bottom seismometers underline the high‐quality data with clear and reliable P‐wave seismic first arrivals. The three‐dimensional tomographic results show that the crust is oceanic on each side of the Zhenbei–Huangyan seamounts chain. The seafloor spreading lineaments and associated fracture zones pattern provide channels for magma migration and eruption. Based on the ratio of volcanic extrusive and intrusive materials and the shape of the upward convex 6.4 km/s iso‐velocity curve beneath the Zhenbei and Huangyan seamounts, we conclude that the Zhenbei and Huangyan seamounts appear to be dominantly formed by intra‐crustal intrusion. Combining previous geochemical studies of post‐spreading volcanic ridge outcropping samples, the formation mechanism of the seamounts chain might be explained by a buoyancy‐driven decompression melting mechanism occurring as separately evolving partial melting bodies beneath each seamount. Copyright © 2016 John Wiley & Sons, Ltd.