bluuebunny/crossref_metadata_2025 huggingface dataset:
Metallic Braided Structures: The Mechanical Modeling
Authors: Rial Djihad , Tiar Amine , Hocine Kebir , Roelandt Jean‐Marc , Wintrebert Eric
Published: January 2015

In this paper, the mechanical behavior of braided metallic structures used in the pipe industry was investigated in both ways numerically and experimentally in order to find the cheapest and the most accurate way to simulate their complex behavior. Therefore, two experimental tests were established to show the tension and the pressure expansion behaviors, then, several finite element approaches were developed and compared with the experiment, which are: a micro‐scale model where each metallic wire is considered as an independent three‐dimensional structure, a meso‐scale model where each group of wires was modeled as a continuum material with equivalent mechanical behavior, and a macro‐scale model where the whole structure is considered as a fully homogeneous material. And it is shown that the homogenization is more suitable for small displacements but for complex behaviors the meso‐ and the micro‐scale models are more reliable.
Reduced Graphene Oxide Micromesh Electrodes for Large Area, Flexible, Organic Photovoltaic Devices
Authors: Konios Dimitrios , Petridis Constantinos , Kakavelakis George , Sygletou Maria , Savva Kyriaki , Stratakis Emmanuel , Kymakis Emmanuel
Published: January 2015

A laser‐based patterning technique—compatible with flexible, temperature‐sensitive substrates—for the production of large area reduced graphene oxide micromesh (rGOMM) electrodes is presented. The mesh patterning can be accurately controlled in order to significantly enhance the electrode transparency, with a subsequent slight increase in the sheet resistance, and therefore improve the tradeoff between transparency and conductivity of reduced graphene oxide (rGO) layers. In particular, rGO films with an initial transparency of ≈20% are patterned, resulting in rGOMMs films with a ≈59% transmittance and a sheet resistance of ≈565 Ω sq−1, that is significantly lower than the resistance of ≈780 Ω sq−1, exhibited by the pristine rGO films at the same transparency. As a proof‐of‐concept application, rGOMMs are used as the transparent electrodes in flexible organic photovoltaic (OPV) devices, achieving power conversion efficiency of 3.05%, the highest ever reported for flexible OPV devices incorporating solution‐processed graphene‐based electrodes. The controllable and highly reproducible laser‐induced patterning of rGO hold enormous promise for both rigid and flexible large‐scale organic electronic devices, eliminating the lag between graphene‐based and indium–tin oxide electrodes, while providing conductivity and transparency tunability for next generation flexible electronics.
Atomic‐Scale Magnetic Properties of Truly 3d‐Diluted ZnO
Authors: Mantovan Roberto , Gunnlaugsson Haraldur Páll , Johnston Karl , Masenda Hilary , Mølholt Torben Esmann , Naidoo Deena , Ncube Mehluli , Shayestehaminzadeh Seyedmohammad , Bharuth‐Ram Krish , Fanciulli Marco , Gislason Haflidi Petur , Langouche Guido , Ólafsson Sveinn , Pereira Lino M. C. , Wahl Ulrich , Torelli Piero , Weyer Gerd
Published: January 2015

In search for dilute magnetic semiconductors, the magnetic properties at the atomic‐scale of Fe atoms incorporated in ZnO, in a concentration range of more than five orders of magnitude from 1 × 10−5 to 2.2 at% have been probed using emission 57Fe Mössbauer spectroscopy on implanted 57Mn and 57Co produced at ISOLDE/CERN. In the ultra‐dilute regime (10−5 at%), the system shows isolated paramagnetic Fe3+ ions with a spin–lattice type of relaxation. At higher concentrations (between 0.02 and 0.2 at%) a transition to spin–spin type of relaxation between neighboring Fe3+ is observed, without any signature of magnetic ordering up to 2.2 at%. Despite the many reports of dilute magnetism in 3d‐doped ZnO, this atomic level study shows no evidence of any long‐range magnetic ordering between isolated Fe atoms incorporated in the ZnO lattice.
Alkylation of Catechol with Benzhydrol: Unusual Regioselectivity in the Synthesis of o‐Quinones and Catechols
Authors: Cherkasov Vladimir K. , Abakumov Gleb A. , Shavyrin Andrey S. , Kuz'michev Vsevolod V. , Baranov Evgeny V. , Smolyaninov Ivan V. , Kuropatov Viacheslav A.
Published: January 2015

Unusual regioselectivity occurs in the alkylation reaction of benzhydrol with catechol. The reaction proceeds to give catechols containing two vicinal diphenylmethyl substituents. 4,5‐Bis‐(diphenylmethyl)‐substituted catechol was found as the main product in more than 50 % yield. The reaction outcome is quite diﬀerent to that of the reactions using bulky alkyl alcohols reported so far, in which 3,5‐ and 3,4,6‐disubstituted species were formed predominantly. The minor products this reaction are 3,5‐di‐ and 3,4,6‐trisubstituted species. Di‐ and trialkylated catechols were oxidized to give the corresponding o‐quinones. The reactivity and physicochemical properties of the new compounds were studied.
The Electronic Factor in Alkane Oxidation Catalysis
Authors: Eichelbaum Maik , Hävecker Michael , Heine Christian , Wernbacher Anna Maria , Rosowski Frank , Trunschke Annette , Schlögl Robert
Published: January 2015

This article addresses the fundamental question of whether concepts from semiconductor physics can be applied to describe the working mode of heterogeneous oxidation catalysts and whether they can be even used to discriminate between selective and unselective reaction pathways. Near‐ambient‐pressure X‐ray photoelectron spectroscopy was applied to the oxidation of n‐butane to maleic anhydride on the highly selective catalyst vanadyl pyrophosphate and the moderately selective MoVTeNbOx M1 phase. The catalysts were found to act like semiconducting gas sensors with a dynamic charge transfer between the bulk and the surface, as indicated by the gas‐phase‐dependent response of the work function, electron affinity, and the surface potential barrier. In contrast, only a minor influence of the gas phase on the semiconducting properties and hence no dynamic surface potential barrier was monitored for the total oxidation catalyst V2O5. The surface potential barrier is hence suggested as descriptor for selective catalysts.
A C3‐Symmetric Macrocycle‐Based, Hydrogen‐Bonded, Multiporous Hexagonal Network as a Motif of Porous Molecular Crystals
Authors: Hisaki Ichiro , Nakagawa Shoichi , Tohnai Norimitsu , Miyata Mikiji
Published: January 2015

A C3‐symmetric π‐conjugated macrocycle combined with an appropriate hydrogen bonding module (phenylene triangle) allowed the construction of crystalline supramolecular frameworks with a cavity volume of up to 58 %. The frameworks were obtained through non‐interpenetrated stacking of a hexagonal sheet possessing three kinds of pores with different sizes and shapes. The activated porous material absorbed CO2 up to 96 cm3 g−1 at 195 K under 1 atm.
One‐Pot Synthesis of Pt–Co Alloy Nanowire Assemblies with Tunable Composition and Enhanced Electrocatalytic Properties
Authors: Xia Bao Yu , Wu Hao Bin , Li Nan , Yan Ya , Lou Xiong Wen (David) , Wang Xin
Published: January 2015

Three‐dimensional (3D) Pt‐based alloy nanostructures composed of one‐dimensional (1D) nanowires/nanorods have recently attracted significant interest as electrocatalysts. In this work, we report an effective solvothermal method for the direct preparation of 3D Pt–Co nanowire assemblies (NWAs) with tunable composition. The composition‐ and structure‐dependent electrocatalytic performance is thoroughly investigated. Because of the bimetallic synergetic effect and unique structural advantage, the as‐prepared 3D Pt3Co NWA outperforms commercial Pt/carbon and Pt black catalysts and even 3D Pt NWA. The electrochemical results demonstrate that the 3D Pt3Co NWA is indeed a promising electrocatalyst with enhanced catalytic activity and improved durability for practical electrocatalytic applications.
Carboxylic Acids as Traceless Directing Groups for the Rhodium(III)‐Catalyzed Decarboxylative CH Arylation of Thiophenes
Authors: Zhang Yuanfei , Zhao Huaiqing , Zhang Min , Su Weiping
Published: January 2015

A rhodium(III)‐catalyzed carboxylic acid directed decarboxylative CH/CH cross‐coupling of carboxylic acids with thiophenes has been developed. With a slight adjustment of the reaction conditions based on the nature of the substrates, aryl carboxylic acids with a variety of substituents could serve as suitable coupling partners, and a broad variety of functional groups were tolerated. This method provides straightforward access to biaryl scaffolds with diverse substitution patterns, many of which have conventionally been synthesized through lengthy synthetic sequences. An illustrative example is the one‐step gram‐scale synthesis of a biologically active 3,5‐substituted 2‐arylthiophene by way of the current method.
A Nuclear Singlet Lifetime of More than One Hour in Room‐Temperature Solution
Authors: Stevanato Gabriele , Hill‐Cousins Joseph T. , Håkansson Pär , Roy Soumya Singha , Brown Lynda J. , Brown Richard C. D. , Pileio Giuseppe , Levitt Malcolm H.
Published: January 2015

Nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) are supremely important techniques with numerous applications in almost all branches of science. However, until recently, NMR methodology was limited by the time constant T1 for the decay of nuclear spin magnetization through contact with the thermal molecular environment. Long‐lived states, which are correlated quantum states of multiple nuclei, have decay time constants that may exceed T1 by large factors. Here we demonstrate a nuclear long‐lived state comprising two 13C nuclei with a lifetime exceeding one hour in room‐temperature solution, which is around 50 times longer than T1. This behavior is well‐predicted by a combination of quantum theory, molecular dynamics, and quantum chemistry. Such ultra‐long‐lived states are expected to be useful for the transport and application of nuclear hyperpolarization, which leads to NMR and MRI signals enhanced by up to five orders of magnitude.
Easy Access to Modified Cyclodextrins by an Intramolecular Radical Approach
Authors: Alvarez‐Dorta Dimitri , León Elisa I. , Kennedy Alan R. , Martín Angeles , Pérez‐Martín Inés , Suárez Ernesto
Published: January 2015

A simple method to modify the primary face of cyclodextrins (CDs) is described. The 6I‐O‐yl radical of α‐, β‐, and γ‐CDs regioselectively abstracts the H5II, located in the adjacent D‐glucose unit, by an intramolecular 1,8‐hydrogen‐atom‐transfer reaction through a geometrically restricted nine‐membered transition state to give a stable 1,3,5‐trioxocane ring. The reaction has been extended to the 1,4‐diols of α‐ and β‐CD to give the corresponding bis(trioxocane)s. The C2‐symmetric bis(trioxocane) corresponding to the α‐CD is a stable crystalline solid whose structure was confirmed by X‐ray diffraction analysis. The calculated geometric parameters confirm that the primary face is severely distorted toward a narrower elliptical shape for this rim.
Gold Nanorod–Photosensitizer Complex Obtained by Layer‐by‐Layer Method for Photodynamic/Photothermal Therapy In Vitro
Authors: Kim Seung Beom , Lee Tae Heon , Yoon Il , Shim Young Key , Lee Woo Kyoung
Published: January 2015

Gold nanorod (GNR)–photosensitizer (PS) complex was prepared using anionic PS (sodium salt of purpurin‐18) and cationic poly(allylamine hydrochloride) by layer‐by‐layer method, and was characterized by transmission electron microscopy, UV‐vis spectroscopy, and zeta potential. The GNR–PS complex is a promising agent for synergistic (photothermal and photodynamic) therapy (PTT/PDT), in which PTT generates heat as well as operates the PS release which maximize the following PDT activity. The combined dual therapy, PTT followed by PDT, exhibits a significantly higher photocytotoxicity result based on synergistic effect of hyperthermia from PTT as well as singlet oxygen photogeneration from PDT.
Ruthenium and Osmium Complexes That Bear Functional Azolate Chelates for Dye‐Sensitized Solar Cells
Authors: Chi Yun , Wu Kuan‐Lin , Wei Tzu‐Chien
Published: January 2015

The preparation of sensitizers for dye‐sensitized solar cells (DSSCs) represents an active area of research for both sustainability and renewable energy. Both RuII and OsII metal sensitizers offer unique photophysical and electrochemical properties that arise from the intrinsic electronic properties, that is, the higher propensity to form the lower‐energy metal‐to‐ligand charge‐transfer (MLCT) transition, and their capability to support chelates with multiple carboxy groups, which serve as a bridge to the metal oxide and enable efficient injection of the photoelectron. Here we present an overview of the synthesis and testing of these metal sensitizers that bear functional azolate chelates (both pyrazolate and triazolate), which are capable of modifying the metal sensitizers in a systematic and beneficial manner. Basic principles of the molecular designs, the structural relationship to the photophysical and electrochemical properties, and performances of the as‐fabricated DSSCs are highlighted. The success in the breakthrough of the synthetic protocols and potential applications might provide strong stimulus for the future development of technologies such as DSSCs, organic light‐emitting diodes, solar water splitting, and so forth.
Determination of acrolein in serum by high‐performance liquid chromatography with fluorescence detection after pre‐column fluorogenic derivatization using 1,2‐diamino‐4,5‐dimethoxybenzene
Authors: Imazato Takahiro , Kanematsu Mariko , Kishikawa Naoya , Ohyama Kaname , Hino Takako , Ueki Yukitaka , Maehata Eisuke , Kuroda Naotaka
Published: January 2015

Acrolein is a major unsaturated aldehyde that is generated during the lipid peroxidation process. The measurement of acrolein in biological samples should be useful to estimate the degree of lipid peroxidation and to evaluate the effect of hazardous properties of acrolein on human health. In this study, a highly sensitive and selective high‐performance liquid chromatography with fluorescence detection method was developed for the determination of acrolein in human serum. The proposed method involves the pre‐column fluorogenic derivatization of acrolein with 1,2‐diamino‐4,5‐dimethoxybenzene (DDB) as a reagent. The fluorescent derivative of acrolein could be detected clearly without any interfering reagent blank peaks because DDB does not have intrinsic fluorescence itself, and the detection limit was 10 nM (signal‐to‐noise ratio = 3). The proposed method could selectively detect acrolein in human serum with a simple protein precipitation treatment. Copyright © 2015 John Wiley & Sons, Ltd.
Effects of human arylamine N‐acetyltransferase I knockdown in triple‐negative breast cancer cell lines
Authors: Tiang Jacky M. , Butcher Neville J. , Minchin Rodney F.
Published: January 2015

Expression of human arylamine N‐acetyltransferase I (NAT1) has been associated with various cancer subtypes and inhibition of this enzyme with small molecule inhibitors or siRNA affects cell growth and survival. Here, we have investigated the role of NAT1 in the invasiveness of breast cancer cells both in vitro and in vivo. We knocked down NAT1 using a lentivirus‐based shRNA approach and observed marked changes in cell morphology in the triple‐negative breast cancer cell lines MDA‐MB‐231, MDA‐MB‐436, and BT‐549. Most notable was a reduction in the number and size of the filopodia protrusions on the surface of the cells. The loss of filopodia could be rescued by the reintroduction of NAT1 into the knockdown cells. NAT1 expression was localized to the lamellipodia and extended into the filopodia protrusions. In vitro invasion through Geltrex was significantly inhibited in both the MDA cell lines but not in the BT‐549 cells. The expression of Snail increased when NAT1 was knocked down, while other genes associated with mesenchymal to epithelial transition (vimentin, cytokeratin‐18, and Twist) did not show any changes. By contrast, both N‐cadherin and β‐catenin were significantly reduced. When MDA‐MB‐231 cells expressing shRNA were injected in vivo into BALB/c nu/nu nude mice, a significant reduction in the number of colonies that formed in the lungs was observed. Taken together, the results show that NAT1 can alter the invasion and metastatic properties of some triple‐negative breast cancer cells but not all. The study suggests that NAT1 may be a novel therapeutic target in a subset of breast cancers.
A Free Cyanohydrin as Arms and Armour of Marasmius oreades
Authors: Caspar Jan , Spiteller Peter
Published: January 2015

Cyanogenic plants and fungi are widespread in nature. Although the origin of hydrocyanic acid in plants has been studied in detail, little is known about its origin in fungi. Here, we report the identification of the cyanohydrin of glyoxylic acid as the precursor of hydrocyanic acid in the fungus Marasmius oreades and several other cyanogenic fungi. Moreover, a feeding experiment revealed glycine as biosynthetic precursor of the cyanohydrin of glyoxylic acid. Thus, the cyanogenesis of M. oreades and other fungi is fundamentally different from cyanogenesis in plants.
Enhanced Basicity of Ag2O by Coordination to Soft Anions
Authors: Ren Bo , Wang Meiyan , Liu Jingyao , Ge Jiantao , Dong Hai
Published: January 2015

In Ag2O‐mediated benzylation, the addition of a catalytic amount of KI can greatly improve reactivity. This is usually attributed to the formation of a more reactive iodo‐substituted electrophile. However, our studies show this to be due to the enhanced basicity of Ag2O through coordination of soft iodide anions to the silver atom, and show KI to be an initiator. A catalytic amount of Ag2O and NaBr can catalyze transesterification reactions, indicating the enhanced basicity of Ag2O by bromide. We believe that this is a general effect for metal oxides and soft anions, applicable to a wider range of organic reaction systems.
Intrinsic Artefacts in Optical Oxygen Sensors—How Reliable are our Measurements?
Authors: Lehner Philipp , Staudinger Christoph , Borisov Sergey M. , Regensburger Johannes , Klimant Ingo
Published: January 2015

Optical oxygen sensing is of broad interest in many areas of research, such as medicine, food processing, and micro‐ and marine biology. The operation principle of optical oxygen sensors is well established and these sensors are routinely employed in lab and field experiments. Ultratrace oxygen sensors, which enable measurements in the sub‐nanomolar region (dissolved oxygen), are becoming increasingly important. Such sensors prominently exhibit phenomena that complicate calibration and measurements. However, these phenomena are not constrained to ultratrace sensors; rather, these effects are inherent to the way optical oxygen sensors work and may influence any optical oxygen measurement when certain conditions are met. This scenario is especially true for applications that deal with high‐excitation light intensities, such as microscopy and microfluidic applications. Herein, we present various effects that we could observe in our studies with ultratrace oxygen sensors and discuss the reasons for their appearance, the mechanism by which they influence measurements, and how to best reduce their impact. The phenomena discussed are oxygen photoconsumption in the sensor material; depletion of the dye ground state by high‐excitation photon‐flux values, which can compromise both intensity and ratiometric‐based measurements; triplet–triplet annihilation; and singlet‐oxygen accumulation, which affects measurements at very low oxygen concentrations.
Oligo(p‐phenyleneethynylene) (OPE) Molecular Wires: Synthesis and Length Dependence of Photoinduced Charge Transfer in OPEs with Triarylamine and Diaryloxadiazole End Groups
Authors: Linton Katharine E. , Fox Mark A. , Pålsson Lars‐Olof , Bryce Martin R.
Published: January 2015

The systematic synthesis and photophysical, electrochemical and computational studies on an extended series of triphenylamine‐[CC‐1,4‐C6H2(OR)2]n‐CC‐diphenyl‐1,3,4‐oxadiazole dyad molecules (the OR groups are at 2,5‐positions of the para‐phenylene ring and R=C6H13; n=0–5, compounds 1, 2, 3, 4 and 5, respectively) are reported. Related molecules with identical end groups, triphenylamine‐CC‐1,4‐C6H2(OR)2‐CC‐triphenylamine (R=C6H13; 6) and diphenyl‐1,3,4‐oxadiazole‐[CC‐C6H2(OR)2]2‐CC‐diphenyl‐1,3,4‐oxadiazole (R=C6H13; 7) were also studied. These D–B–A 1–5, D–B–D 6 and A–B–A 7 (D=electron donor, B=bridge, A=electron acceptor) systems were synthesized using palladium‐catalysed cross‐coupling reactions of new p‐phenyleneethynylene building blocks. Steady‐state emission studies on the dyads 1–5 reveal a complicated behavior of the emission that is strongly medium dependent. In low polarity solvents the emission is characterized by a sharp high‐energy peak attributed to fluorescence from a locally excited (LE) state. In more polar environments the LE state is effectively quenched by transfer into an intramolecular charge‐transfer (ICT) state. The medium dependence is also observed in the quantum yields (QYs) which are high in cyclohexane and low in acetonitrile, thus also indicating charge‐transfer character. Low‐temperature emission spectra for 2–5 in dichloromethane and diethyl ether also reveal two distinct excited states, namely the LE state and the conventional ICT state, depending on solvent and temperature. Hybrid DFT calculations for 1–7 establish that the OPE bridge is involved in both frontier orbitals where the bridge character increases as the bridge length increases. Computed TD‐DFT data on 1–5 assign the emission maxima in cyclohexane as LE transitions. Each time‐resolved emission measurement on 2–7 in cyclohexane and diethyl ether reveals a wavelength dependent bi‐exponential decay of the emission with a fast component in the 5–61 ps range on blue detection and a slower approximately 1 ns phase, independent of detection wavelength. The fast component is attributed to LE fluorescence and this emission component is rate limited and quenched by transfer into an ICT state. The fast LE fluorescence component varies systematically with conjugation length for the series of D–B–A dyads 2–5. An attenuation factor β of 0.15 Å−1 was determined in accordance with an ICT superexchange mechanism.
An Organocatalytic Mannich/Denitration Reaction for the Asymmetric Synthesis of 3‐Ethylacetate‐Substitued 3‐Amino‐2‐Oxindoles: Formal Synthesis of AG‐041R
Authors: Zhao Kun , Shu Tao , Jia Jiaqi , Raabe Gerhard , Enders Dieter
Published: January 2015

The highly enantioselective organocatalytic addition of ethyl nitroacetate to isatin‐derived N‐Boc ketimines (Boc=tert‐butoxycarbonyl), followed by the removal of the nitro group, is described. The scalable reaction sequence leads to the title compounds as important intermediates of pyrroloindoline alkaloids and related drugs in excellent yields and enantioselectivities. The synthesis of the hexahydrofurano[2,3‐b]indole skeleton, the spirocarbamate oxindole unit, and the formal synthesis of AG‐041R have been carried out to demonstrate the synthetic utility of this protocol.
Amino Acid Derived Phosphine‐Catalyzed Enantioselective 1,4‐Dipolar Spiroannulation of Cyclobutenones and Isatylidenemalononitrile
Authors: Li Yangyan , Su Xiao , Zhou Wei , Li Wenbo , Zhang Junliang
Published: January 2015

Cyclobutenones have been explored as a new type of chiral 1,4‐dipole four‐carbon synthon, which readily undergoes organophosphine‐mediated CC bond cleavage and asymmetric intermolecular 1,4‐dipolar spiroannulation with isatylidenemalononitrile in the presence of amino acid‐derived chiral phosphine catalyst to furnish enantioenriched 3‐spirocyclohexenone 2‐oxindoles in good yield with up to 87 % ee. To our knowledge, this is the first example of asymmetric transformation of cyclobutenones and the phosphine‐catalyzed asymmetric 1,4‐dipolar cycloaddition consisting of CC bond activation is unprecedented.
Liquid Chromatographic Resolution of Amino Acid Esters of Acyclovir Including Racemic Valacyclovir on Crown Ether‐Based Chiral Stationary Phases
Authors: Ahn Seong Ae , Hyun Myung Ho
Published: January 2015

Valacyclovir, a potential prodrug for the treatment of patients with herpes simplex and herpes zoster, and its analogs were resolved on two chiral stationary phases (CSPs) based on (3,3’‐diphenyl‐1,1’‐binaphthyl)‐20‐crown‐6 covalently bonded to silica gel. In order to find out an appropriate mobile phase condition, various mobile phases consisting of various organic modifiers in water containing various acidic modifiers were applied to the resolution of valacyclovir and its analogs. When 30% acetonitrile in water containing any of 0.05 M, 0.10 M, or 0.15 M perchloric acid was used as a mobile phase, valacyclovir and its analogs were resolved quite well on the two CSPs with the separation factors (α) in the range of 2.49 ~ 6.35 and resolutions (RS) in the range of 2.95 ~ 12.21. Between the two CSPs, the CSP containing residual silanol protecting n‐octyl groups on the silica surface was found to be better than the CSP containing residual silanol groups. Chirality 27:268–273, 2015. © 2015 Wiley Periodicals, Inc.
Large‐scale tracking and classification for automatic analysis of cell migration and proliferation, and experimental optimization of high‐throughput screens of neuroblastoma cells
Authors: Harder Nathalie , Batra Richa , Diessl Nicolle , Gogolin Sina , Eils Roland , Westermann Frank , König Rainer , Rohr Karl
Published: January 2015

Computational approaches for automatic analysis of image‐based high‐throughput and high‐content screens are gaining increased importance to cope with the large amounts of data generated by automated microscopy systems. Typically, automatic image analysis is used to extract phenotypic information once all images of a screen have been acquired. However, also in earlier stages of large‐scale experiments image analysis is important, in particular, to support and accelerate the tedious and time‐consuming optimization of the experimental conditions and technical settings. We here present a novel approach for automatic, large‐scale analysis and experimental optimization with application to a screen on neuroblastoma cell lines. Our approach consists of cell segmentation, tracking, feature extraction, classification, and model‐based error correction. The approach can be used for experimental optimization by extracting quantitative information which allows experimentalists to optimally choose and to verify the experimental parameters. This involves systematically studying the global cell movement and proliferation behavior. Moreover, we performed a comprehensive phenotypic analysis of a large‐scale neuroblastoma screen including the detection of rare division events such as multi‐polar divisions. Major challenges of the analyzed high‐throughput data are the relatively low spatio‐temporal resolution in conjunction with densely growing cells as well as the high variability of the data. To account for the data variability we optimized feature extraction and classification, and introduced a gray value normalization technique as well as a novel approach for automatic model‐based correction of classification errors. In total, we analyzed 4,400 real image sequences, covering observation periods of around 120 h each. We performed an extensive quantitative evaluation, which showed that our approach yields high accuracies of 92.2% for segmentation, 98.2% for tracking, and 86.5% for classification. © 2015 International Society for Advancement of Cytometry
Structure and diversity of phyllostomid bat assemblages on riparian corridors in a human‐dominated tropical landscape
Authors: de la Peña‐Cuéllar Erika , Benítez‐Malvido Julieta , Avila‐Cabadilla Luis Daniel , Martínez‐Ramos Miguel , Estrada Alejandro
Published: January 2015

Tropical forests around the world have been lost, mainly because of agricultural activities. Linear elements like riparian vegetation in fragmented tropical landscapes help maintain the native flora and fauna. Information about the role of riparian corridors as a reservoir of bat species, however, is scanty. We assessed the value of riparian corridors on the conservation of phyllostomid bat assemblage in an agricultural landscape of southern Mexico. For 2 years (2011–2013), mist‐netting at ground level was carried out twice during the dry season (December to May) and twice during the wet season (June to November) in different habitats: (1) riparian corridors in mature forest, (2) riparian corridors in pasture, (3) continuous forest away from riparian vegetation, and (4) open pastures. Each habitat was replicated three times. To determine the influence of vegetation structure on bat assemblages, all trees (≥10 cm dbh) were sampled in all habitats. Overall, 1752 individuals belonging to 28 species of Phyllostomidae were captured with Sternodermatinae being the most rich and abundant subfamily. Riparian corridors in mature forest and pastures had the greatest species richness and shared 65% of all species. Open pastures had the lowest richness and abundance of bats with no Phyllostominae species recorded. Six of the 18 species recorded could be considered as habitat indicators. There was a positive relationship between bat species composition and tree basal area. Our findings suggest that contrary to our expectations, bats with generalist habits and naturally abundant could be useful detector taxa of habitat modification, rather than bats strongly associated with undisturbed forest. Also in human‐dominated landscapes, the maintenance of habitat elements such as large trees in riparian corridors can serve as reservoirs for bat species, especially for those that are strongly associated with undisturbed forest.
5‐Ferrocenyl‐1H‐tetrazole‐Derived Transition‐Metal Complexes: Synthesis, Crystal Structures and Catalytic Effects on the Thermal Decomposition of the Main Components of Solid Propellants
Authors: Wang Chunyan , Li Jizhen , Fan Xuezhong , Zhao Fengqi , Zhang Weiqiang , Zhang Guofang , Gao Ziwei
Published: January 2015

With the aim of developing low‐migratory burning‐rate (BR) catalysts for solid propellants, a series of transition‐metal complexes of 5‐ferrocenyl‐1H‐tetrazole (HFcTz), [Cu2(bpy)2(FcTz)4]·2C2H5OH (1), [Pb(phen)2(H2O)3](FcTz)2·H2O (3), [Cu(phen)3](FcTz)2·8H2O (4), [Mn(phen)2(H2O)2](FcTz)2 (5), [Mn(bpy)(H2O)4](FcTz)2 (6), [Ni(phen)3](FcTz)2·9H2O (7), and [Co(phen)3](FcTz)2·9H2O (8) (bpy = 2,2′‐bipyridine; phen = 1,10‐phenanthroline), were synthesized and structurally characterized. Only a limited number of single crystals of [Pb2(phen)4(CO3)](FcTz)2·phen·9H2O (2) were formed so only its crystal structure was analyzed. The complexes show high thermal stability. Cyclic voltammetry investigations suggested that 1 and 3–7 exhibit quasireversible redox systems. Their catalytic effects on the thermal degradation of ammonium perchlorate (AP), 1,3,5‐trinitro‐1,3,5‐triazacyclohexane (RDX), and 1,2,5,7‐tetranitro‐1,3,5,7‐tetraazacyclooctane (HMX) were evaluated by differential scanning calorimetry (DSC) and thermogravimetric (TG) methods. The optimum content of the new compounds in AP, RDX, and HMX was established to be 5, 5, and 2 wt.‐%, respectively. They exhibit high catalytic activities in the thermal decomposition of AP and RDX. Among them, 6 was found to be the best ferrocene‐based BR catalyst.
Hydropeaking induces losses from a river reach: observations at multiple spatial scales
Authors: Yellen B. , Boutt D.F.
Published: January 2015

In humid regions, where gaining river conditions generally prevail, daily hydroelectric dam releases alter downstream surface water–groundwater interactions by reversing the head gradient between river and adjacent groundwater. Previously, it has been noted that artificial stage changes due to dam releases enhance hyporheic exchange. Here we investigate the regulated Deerfield River in northwestern Massachusetts at multiple scales to evaluate how changing downstream geologic conditions along the river mediate this artificial hyporheic pumping.

Water budget analysis indicates that roughly 10% of bank‐stored water is permanently lost from the 19.5‐km river reach, likely as a result of transpiration by bank vegetation. An adjacent reference stream with similar dimensions and geomorphology, but without hydropeaking, shows predictable gaining conditions. Field observations from streambed piezometers and thermistors show that water losses are not uniform throughout the study reach. Riparian aquifer transmissivity in river sub‐reaches largely determines the magnitude of surface water–groundwater exchange as well as net water loss from the river. These newly documented losses from hydropeaking river systems should inform decisions by river managers and hydroelectric operators of additional tradeoffs of oscillatory dam‐release river management. Copyright © 2015 John Wiley & Sons, Ltd.
A meta‐analysis of hospital evacuations: Overcoming barriers to effective planning
Authors: Hicks Jarred , Glick Roger
Published: January 2015

A hospital evacuation is a significant disaster scenario facing today's Hospital Emergency Coordinators (HECs) and Risk Managers. In this work we explore the numerous barriers that prevent HECs from being able to effectively plan for and execute hospital evacuations based on a review of the pertinent literature of the last 30 years. We discuss the finding that the reasons for the success or failure generally fall into 1 or more of 8 broad categories: Predisaster Assessment, Logistics, Communications, Community Relationships, Manual Records and Tracking, Resource Management, Special Patient Populations, and Postevacuation Return.
Fall prevention in our healthiest patients: Assessing risk and preventing injury for moms and babies
Authors: Gaffey Ann D.
Published: January 2015

Attention is needed in preventing patient falls in newborns and in obstetric units of hospitals. The majority of prenatal, postpartum, and newborn falls are preventable. Little effort has been made to address fall risk during the prenatal period, during labor, and after delivery in the postpartum period for moms and babies. Risk factors for falls in these populations have been identified, and targeted risk assessments and fall prevention interventions have been developed to eliminate these falls. Evidence demonstrates success in reducing falls with a variety of low‐cost but high‐return initiatives, comprising prenatal education, patient and family engagement, implementation of unique fall risk assessment tools, postpartum mobility assessments, and changes in patient rounding frequency.
Ultra high performance liquid chromatography tandem mass spectrometry method for the simultaneous determination of multiple bioactive constituents in fruit extracts of Myristica fragrans and its marketed polyherbal formulations using a polarity switching technique
Authors: Pandey Renu , Rameshkumar Koranappallil Bahuleyan , Kumar Brijesh
Published: January 2015

Fruits of Myristica fragrans Houtt. are the source of two valuable spices: nutmeg and mace, traditionally used for its flavoring and medicinal properties and found as an ingredient in many marketed polyherbal formulations and food products. In this study, a sensitive and efficient ultra high performance liquid chromatography electrospray ionization tandem mass spectrometry method was developed and validated for the rapid determination of 16 bioactive constituents in different parts of the fruit of M. fragrans and its marketed polyherbal formulations using a polarity switching technique. Chromatographic separation was achieved on an Aquity UPLC BEH C18 column in 9.4 min. Quantitative analysis was performed using multiple reaction monitoring mode with continuous polarity switching in a single analysis. The developed method was found to be accurate with overall recovery in the range from 95.95 to 102.07% (RSD ≤ 1.91%), precise (RSD ≤ 1.98%), and linear (r2 ≥ 0.9992) over the concentration range of 0.1–200 ng/mL. Quantitative analysis indicated that the total content of the 16 bioactive constituents was highest in the mace of M. fragrans. Thus, this rapid and sensitive method could be utilized as a promising reference method for the quality control of M. fragrans and its marketed herbal formulations/food products.
The Market Maven Crowd: Collaborative Risk‐Aversion and Enhanced Consumption Context Control in an Illicit Market
Authors: O'Sullivan Stephen R.
Published: January 2015

Contemporary culture is characterized by individual and societal efforts to limit exposure to risk. Paradoxically, many consumers actively pursue high‐risk consumption experiences. High‐risk consumption, coupled with a lack of consumption‐orientated information, amplifies consumer vulnerability. However, consumer‐to‐consumer information sharing can help reduce unwarranted risk and enhance consumption context control. This study investigates the ecstasy “market maven crowd”: an online community anonymously bound by acts of collective market mavenism intended to address the void of market information and reduce the risks thereof. Acts of collective market mavenism include the assimilation and dissemination of scientific ecstasy pill content reports and personal ecstasy consumption tales. The diffusion of market‐orientated information provides consumers with an opportunity to identify, and avert, the serious health risks intrinsic to ecstasy consumption and assert consumption context control. Collaborative market mavenism fosters market policing, which enhances the safety structures of the unregulated ecstasy market. This study contributes to marketing and consumer research by developing an understanding of how consumers collectively adapt to risk online; displaying market mavenism as an innovative framework to examine online consumer‐to‐consumer information sharing; showing how Internet technologies facilitate the emergence of market maven crowds; and providing marketers with guidelines for approaching market maven crowds. Finally, the author discusses the societal implications arising and suggests directions for future research.
Synthesis of Triplet–Triplet Annihilation Upconversion Nanocapsules Under Protective Conditions
Authors: Katta Kartheek , Busko Dmitry , Avlasevich Yuri , Muñoz‐Espí Rafael , Baluschev Stanislav , Landfester Katharina
Published: January 2015

Triplet–triplet annihilation upconversion (TTA‐UC) nanocapsules are synthesized under oxygen‐protective conditions (i.e., complete darkness and argon atmosphere) by free‐radical miniemulsion polymerization. These conditions help to exclude the oxidation of the emitter molecules caused by singlet oxygen, generated during the synthesis at daylight conditions and oxygen‐rich environment. Subsequently, keeping all the other experimental conditions the same, samples synthesized at protective conditions demonstrate substantially increased UC efficiency. These experimental facts strongly support the hypothesis that posterior removing of oxygen from TTA‐UC nanocapsules is not sufficient to obtain reproducible and sustainable UC results. The schematic representation shows the influence of sunlight on the formation of singlet oxygen and its effect on the triplet–triplet annihilation upconversion process.

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Studies on supramolecular gel formation using DOSY NMR
Authors: Nonappa  , Šaman David , Kolehmainen Erkki
Published: January 2015

Herein, we present the results obtained from our studies on supramolecular self‐assembly and molecular mobility of low‐molecular‐weight gelators (LMWGs) in organic solvents using pulsed field gradient (PFG) diffusion ordered spectroscopy (DOSY) NMR. A series of concentration‐dependent DOSY NMR experiments were performed on selected LMWGs to determine the critical gelation concentration (CGC) as well as to understand the behaviour of the gelator molecules in the gel state. In addition, variable‐temperature DOSY NMR experiments were performed to determine the gel‐to‐sol transition. The PFG NMR experiments performed as a function of gradient strength were further analyzed using monoexponential DOSY processing, and the results were compared with the automated Bayesian DOSY transformation to obtain 2D plots. Our results provide useful information on the stepwise self‐assembly of small molecules leading to gelation. We believe that the results obtained from these experiments are applicable in determining the CGC and gel melting temperatures of supramolecular gels. Copyright © 2015 John Wiley & Sons, Ltd.
Effect of Monomer Concentration and pH on Reaction Kinetics and Copolymer Microstructure of Acrylamide/Acrylic Acid Copolymer
Authors: Riahinezhad Marzieh , McManus Neil , Penlidis Alexander
Published: January 2015

Acrylamide (AAm)/acrylic acid (AAc) copolymer application performance is tied to copolymer properties, which in turn are related to the kinetics of the copolymerization. A systematic study has been conducted to investigate the effect of reaction factors such as total monomer concentration and solution pH on polymerization kinetics and copolymer microstructure. To study the effect of these factors, reliable reactivity ratios were estimated first. The trends in copolymer composition, molecular weight, sequence length distribution, and triad fractions were subsequently examined. Having a better understanding of kinetic profiles is needed in order to manipulate influential factors for tailoring AAm/AAc copolymer properties for the desired application.
An SMP critical state model for methane hydrate‐bearing sands
Authors: Lin Jeen‐Shang , Seol Yongkoo , Choi Jeong Hoon
Published: January 2015

Mechanical properties of methane hydrate‐bearing soils are complex. Their behavior undergoes a significant change when hydrates dissociate and become methane gas. On the other hand, methane hydrates are ice‐like compounds and, depending on the hydrate accumulation habits and the degree of hydrate saturation, may cement soil particles into stronger and stiffer soils. A new constitutive model is proposed that is capable of capturing essential characteristics of hydrate‐bearing soils. The core of the model includes the spatial mobilized plane concept; a transformed stress, tij; the critical state; and the subloading framework. The proposed model gives soil responses due to stress changes or hydrate saturation changes or both. The performance of the model has been found satisfactory, over a range of hydrate saturation and confining pressures, using triaxial test data from laboratory‐synthesized samples and from field samples extracted from Nankai Trough, Japan. Copyright © 2015 John Wiley & Sons, Ltd.
Synthesis and characterization of 15% efficient CIGSSe solar cells from nanoparticle inks
Authors: McLeod Steven M. , Hages Charles J. , Carter Nathaniel J. , Agrawal Rakesh
Published: January 2015

We report a total‐area power conversion efficiency of 15% for a copper indium gallium disulfoselenide (CIGSSe) solar cell fabricated from a copper indium gallium disulfide (CIGS) nanoparticle ink based process. Careful optimization of the fabrication process has resulted in a significant improvement in efficiency compared to our previously reported efficiency of 12%. This efficiency ranks among the highest reported in the literature for solution processed CIGSSe. Despite having an absorber thickness of approximately 700–800 nm, which is less than half the thickness of high efficiency devices grown by both coevaporation and solution processes in the literature, our devices show good short‐circuit current (32.1 mA/cm2). Surprisingly, the sintered film shows lateral composition fluctuations, which have not been reported for other high efficiency devices and may be responsible for the lower open circuit voltage (636 mV) observed here. This suggests an avenue for further improvement through optimization of the nanoparticle selenization process to better control composition in the sintered film. Copyright © 2015 John Wiley & Sons, Ltd.
What else do managers need to know about warming rivers? A United Kingdom perspective
Authors: Orr Harriet G. , Johnson Matthew F. , Wilby Robert L. , Hatton‐Ellis Tristan , Broadmeadow Samantha
Published: January 2015

River flow and water temperature are fundamental controls of freshwater ecosystems. Hence, future warming could impact valued habitats and species, particularly those with cold water preferences (such as salmonids). Warming could also exacerbate existing environmental pressures or diminish the effectiveness of management interventions. Climate model projections provide compelling evidence of the need for adaptation despite uncertainty about the timing, nature, and distribution of impacts on water quality, vulnerable species, and habitats. Low‐regret adaptation options to manage temperature impacts include increasing riparian shade, enhancing thermal refugia, and removing thermal barriers or hotspots. Indirect controls include managing river flows through abstraction and discharge regulation, moderating flow control structures, and manipulating channel hydromorphology. However, fundamental gaps in understanding may limit the effectiveness of some of these measures, leading to undesired side effects, wasted resources, ineffectual outcomes, or limited uptake. These knowledge gaps include where to target measures, how to implement in different situations, how to maximize co‐benefits and integrate with other policy objectives, and how to support implementation across rural and agricultural landscapes. Despite many uncertainties, restoration of riparian shade and river flows has the potential to deliver multiple benefits even if this does not include retarding rates of warming. WIREs Water 2015, 2:55–64. doi: 10.1002/wat2.1062

This article is categorized under:

Water and Life > Conservation, Management, and Awareness

Water and Life > Stresses and Pressures on Ecosystems

Science of Water > Water and Environmental Change
Critical approaches to urban water governance: from critique to justice, democracy, and transdisciplinary collaboration
Authors: Finewood Michael H. , Holifield Ryan
Published: January 2015

As global urban regions grow and transform, water systems present a unique set of challenges to stakeholders. Municipalities often struggle to pay for and maintain aging infrastructure as well as create equitable access for growing populations—especially in the rapidly urbanizing Global South. Critical approaches to urban water governance have made tremendous contributions to our collective knowledge of how these systems work. In this study, we argue that the most important direction for these approaches to urban water governance is to translate the insights generated by critique into the positive project to construct more just and democratic systems and practices of governance. However, we contend that in order to do this work, critical scholarship on urban water governance will need to continue deepening its engagement with two larger sets of debates. First, to help realize more just and democratic systems, it will need to grapple with the complex dimensions of debates on how to theorize and conceptualize justice and democracy. Second, in order to create effective alternatives to current paradigms of water governance, it will need to show how recent conceptualizations of urban water as hybrid or heterogeneous assemblage can help build truly transdisciplinary collaborations. We explore these debates through a review of recent critical approaches to urban water governance, with attention to ways forward that embrace epistemological pluralism and transdisciplinary collaboration. WIREs Water 2015, 2:85–96. doi: 10.1002/wat2.1066

This article is categorized under:

Engineering Water > Planning Water

Human Water > Water Governance