bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermo‐Phototronic Effect Enhanced InP/ZnO Nanorod Heterojunction Solar Cells for Self‐Powered Wearable Electronics
Authors: Zhang Kewei , Yang Ya
Published: August 2017

Enhancing interfacial charge transfer by the inner electric field is crucial for improving photovoltaic performance of heterojunction solar cells. Recent studies are focusing on how to utilize piezo‐phototronic effect (strain‐induced inner electric field) to modulate the interfacial charge transfer, whereas the preservation of solar cells from structure damage and performance decline under long‐term strain becomes increasingly challenging. Here, without use of strain, a thermo‐phototronic effect is presented to enhance the interfacial charge transfer in InP/ZnO nanorod heterojunction solar cells. Under a temperature gradient of 3.5 °C across the device, the output current and voltage of the solar cell under weak light illumination are enhanced by 27.3 and 76%, respectively. Moreover, the performance enhancement can be further regulated by applying different temperature gradients. This study serves as proof‐of‐principle for the thermo‐phototronic effect and pushes forward the maximum utilization of solar energy by a one‐circuit‐based photovoltaic‐thermoelectric system.
Particle Targeting in Complex Biological Media
Authors: Dai Qiong , Bertleff‐Zieschang Nadja , Braunger Julia A. , Björnmalm Mattias , Cortez‐Jugo Christina , Caruso Frank
Published: August 2017

Over the past few decades, nanoengineered particles have gained increasing interest for applications in the biomedical realm, including diagnosis, imaging, and therapy. When functionalized with targeting ligands, these particles have the potential to interact with specific cells and tissues, and accumulate at desired target sites, reducing side effects and improve overall efficacy in applications such as vaccination and drug delivery. However, when targeted particles enter a complex biological environment, the adsorption of biomolecules and the formation of a surface coating (e.g., a protein corona) changes the properties of the carriers and can render their behavior unpredictable. For this reason, it is of importance to consider the potential challenges imposed by the biological environment at the early stages of particle design. This review describes parameters that affect the targeting ability of particulate drug carriers, with an emphasis on the effect of the protein corona. We highlight strategies for exploiting the protein corona to improve the targeting ability of particles. Finally, we provide suggestions for complementing current in vitro assays used for the evaluation of targeting and carrier efficacy with new and emerging techniques (e.g., 3D models and flow‐based technologies) to advance fundamental understanding in bio‐nano science and to accelerate the development of targeted particles for biomedical applications.
A Cooperative Ternary Catalysis System for Asymmetric Lactonizations of α‐Ketoesters
Authors: Murauski Kathleen J. R. , Walden Daniel M. , Cheong Paul Ha‐Yeon , Scheidt Karl A.
Published: August 2017

A general and enantioselective N‐heterocyclic carbene (NHC)‐catalyzed lactonization of simple enals and α‐ketoesters has been discovered using a new ternary cooperative catalytic system. The highly selective annulation was achieved by using a combination of a chiral NHC, a hydrogen‐bond donor, and a metal salt, facilitating self‐assembly of the reactive partners. A proposed model for this new mode of NHC chiral relay catalysis is supported by experimental and computational mechanistic studies.

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Palladium‐Catalyzed Carbon–Fluorine and Carbon–Hydrogen Bond Alumination of Fluoroarenes and Heteroarenes
Authors: Chen Wenyi , Hooper Thomas N. , Ng Jamues , White Andrew J. P. , Crimmin Mark R.
Published: August 2017

Through serendipitous discovery, a palladium bis(phosphine) complex was identified as a catalyst for the selective transformation of sp2C−F and sp2C−H bonds of fluoroarenes and heteroarenes to sp2C−Al bonds (19 examples, 1 mol % Pd loading). The carbon–fluorine bond functionalization reaction is highly selective for the formation of organoaluminium products in preference to hydrodefluorination products (selectivity=4.4:1 to 27:1). Evidence is presented for a tandem catalytic process in which hydrodefluorination is followed by sp2C−H alumination.
Fe‐Doped Ni3C Nanodots in N‐Doped Carbon Nanosheets for Efficient Hydrogen‐Evolution and Oxygen‐Evolution Electrocatalysis
Authors: Fan Haosen , Yu Hong , Zhang Yufei , Zheng Yun , Luo Yubo , Dai Zhengfei , Li Bing , Zong Yun , Yan Qingyu
Published: August 2017

Uniform Ni3C nanodots dispersed in ultrathin N‐doped carbon nanosheets were successfully prepared by carburization of the two dimensional (2D) nickel cyanide coordination polymer precursors. The Ni3C based nanosheets have lateral length of about 200 nm and thickness of 10 nm. When doped with Fe, the Ni3C based nanosheets exhibited outstanding electrocatalytic properties for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). For example, 2 at % Fe (atomic percent) doped Ni3C nanosheets depict a low overpotential (292 mV) and a small Tafel slope (41.3 mV dec−1) for HER in KOH solution. An outstanding OER catalytic property is also achieved with a low overpotential of 275 mV and a small Tafel slope of 62 mV dec−1 in KOH solution. Such nanodot‐incorporated 2D hybrid structures can serve as an efficient bifunctional electrocatalyst for overall water splitting.
Real‐Time Intracellular Measurements of ROS and RNS in Living Cells with Single Core–Shell Nanowire Electrodes
Authors: Zhang Xin‐Wei , Qiu Quan‐Fa , Jiang Hong , Zhang Fu‐Li , Liu Yan‐Lin , Amatore Christian , Huang Wei‐Hua
Published: August 2017

Nanoelectrodes allow precise and quantitative measurements of important biological processes at the single living‐cell level in real time. Cylindrical nanowire electrodes (NWEs) required for intracellular measurements create a great challenge for achieving excellent electrochemical and mechanical performances. Herein, we present a facile and robust solution to this problem based on a unique SiC‐core–shell design to produce cylindrical NWEs with superior mechanical toughness provided by the SiC nano‐core and an excellent electrochemical performance provided by the ultrathin carbon shell that can be used as such or platinized. The use of such NWEs for biological applications is illustrated by the first quantitative measurements of ROS/RNS in individual phagolysosomes of living macrophages. As the shell material can be varied to meet any specific detection purpose, this work opens up new opportunities to monitor quantitatively biological functions occurring inside cells and their organelles.
Discovery of Key Physicochemical, Structural, and Spatial Properties of RNA‐Targeted Bioactive Ligands
Authors: Morgan Brittany S. , Forte Jordan E. , Culver Rebecca N. , Zhang Yuqi , Hargrove Amanda E.
Published: August 2017

While a myriad non‐coding RNAs are known to be essential in cellular processes and misregulated in diseases, the development of RNA‐targeted small molecule probes has met with limited success. To elucidate the guiding principles for selective small molecule/RNA recognition, we analyzed cheminformatic and shape‐based descriptors for 104 RNA‐targeted ligands with demonstrated biological activity (RNA‐targeted BIoactive ligaNd Database, R‐BIND). We then compared R‐BIND to both FDA‐approved small molecule drugs and RNA ligands without reported bioactivity. Several striking trends emerged for bioactive RNA ligands, including: 1) Compliance to medicinal chemistry rules, 2) distinctive structural features, and 3) enrichment in rod‐like shapes over others. This work provides unique insights that directly facilitate the selection and synthesis of RNA‐targeted libraries with the goal of efficiently identifying selective small molecule ligands for therapeutically relevant RNAs.
Donor–Acceptor Complex Enables Alkoxyl Radical Generation for Metal‐Free C(sp3)–C(sp3) Cleavage and Allylation/Alkenylation
Authors: Zhang Jing , Li Yang , Xu Ruoyu , Chen Yiyun
Published: August 2017

The alkoxyl radical is an essential and prevalent reactive intermediate for chemical and biological studies. Here we report the first donor–acceptor complex‐enabled alkoxyl radical generation under metal‐free reaction conditions induced by visible light. Hantzsch ester forms the key donor–acceptor complex with N‐alkoxyl derivatives, which is elucidated by a series of spectrometry and mechanistic experiments. Selective C(sp3)‐C(sp3) bond cleavage and allylation/alkenylation is demonstrated for the first time using this photocatalyst‐free approach with linear primary, secondary, and tertiary alkoxyl radicals.
Quasi‐Dual‐Packed‐Kerneled Au49(2,4‐DMBT)27 Nanoclusters and the Influence of Kernel Packing on the Electrochemical Gap
Authors: Liao Lingwen , Zhuang Shengli , Wang Pu , Xu Yanan , Yan Nan , Dong Hongwei , Wang Chengming , Zhao Yan , Xia Nan , Li Jin , Deng Haiteng , Pei Yong , Tian Shi‐Kai , Wu Zhikun
Published: August 2017

Although face‐centered cubic (fcc), body‐centered cubic (bcc), hexagonal close‐packed (hcp), and other structured gold nanoclusters have been reported, it was unclear whether gold nanoclusters with mix‐packed (fcc and non‐fcc) kernels exist, and the correlation between kernel packing and the properties of gold nanoclusters is unknown. A Au49(2,4‐DMBT)27 nanocluster with a shell electron count of 22 has now been been synthesized and structurally resolved by single‐crystal X‐ray crystallography, which revealed that Au49(2,4‐DMBT)27 contains a unique Au34 kernel consisting of one quasi‐fcc‐structured Au21 and one non‐fcc‐structured Au13 unit (where 2,4‐DMBTH=2,4‐dimethylbenzenethiol). Further experiments revealed that the kernel packing greatly influences the electrochemical gap (EG) and the fcc structure has a larger EG than the investigated non‐fcc structure.
Utilization of industrial waste as a novel adsorbent: Mono/competitive adsorption of chromium(VI) and nickel(II) using diatomite waste modified by EDTA
Authors: Sha Haitao , Wu Yunhai , Fan Yiang
Published: August 2017

The adsorption of Cr(VI) and Ni(II) using ethylenediaminetetraacetic acid‐modified diatomite waste (EDTA‐DW) as an adsorbent in single and binary systems was investigated. The EDTA‐DW was characterized using various analytical techniques, including Fourier transform infrared spectroscopy, thermogravimetric analysis, Brunauer–Emmett–Teller measurements, X‐ray diffraction, scanning electron microscopy and energy‐dispersive spectrometry. The adsorption experiment was conducted by varying pH, adsorbent dosage, initial concentration and temperature. In the single system, the sorption data for Cr(VI) fitted the Langmuir isotherm, but the Ni(II) adsorption data fitted well the Freundlich isotherm. The maximum sorption capacity of Cr(VI) and Ni(II) was 2.9 mg g−1 at pH = 3 and 3.64 mg g−1 at pH = 8, respectively. The kinetic data for both Cr(VI) and Ni(II) followed well the pseudo‐second‐order kinetic model in single and binary systems. Meanwhile, the extended Langmuir and extended Freundlich multicomponent isotherm models were found to fit the competitive adsorption data for Cr(VI) and Ni(II). In addition, in the binary system, the existence of Ni(II) hindered the adsorption of Cr(VI), but the presence of Cr(VI) enhanced the removal of Ni(II). This study provides some realistic and valid data about the usage of modified diatomite waste for the removal of metal ions.
Facile synthesis of PtSnZn nanosheet thin film at oil–water interface by use of organometallic complexes: An efficient catalyst for methanol oxidation and p‐nitrophenol reduction reactions
Authors: Sarmoor Sajad Saberi , Hoseini S. Jafar , Hashemi Fath Roghayeh , Roushani Mahmoud , Bahrami Mehrangiz
Published: August 2017

PtSnZn nanosheet thin film with stable and high activity towards methanol electro‐oxidation was synthesized via a simple reduction of organometallic precursors including [PtCl2(cod)] (cod = cis,cis‐1,5‐cyclooctadiene) and [Sn(CH3)4] complexes, in the presence of [Zn(acac)2] (acac = acetylacetonate) complex at toluene–water interface. Catalytic activities of PtSnZn nanosheets were investigated in the p‐nitrophenol (p‐Nip) reduction and methanol oxidation reactions. The obtained results demonstrate that PtSnZn nanosheets exhibit a good electrocatalytic performance for methanol oxidation reaction, the catalytic activity of the PtSnZn nanosheets being at least 3.5 times higher than that of Pt nanoparticle thin film. Also, the apparent rate constant obtained for p‐Nip reduction with the PtSnZn nanosheets is at least 2.3 times higher than that for Pt nanoparticle thin film due to the appropriate interaction between platinum, tin and zinc metals and geometric properties of PtSnZn nanosheet thin film. Nanosheets are highly favourable for superior catalytic performances due to their geometric properties. A facile and efficient route was used to synthesize trimetallic alloy thin film at oil–water interface.
Synthesis, characterization and photocatalytic application of TiO2/magnetic graphene for efficient photodegradation of crystal violet
Authors: Piranshahi Zahra Aalimohammadi , Behbahani Mohammad , Zeraatpisheh Fatemeh
Published: August 2017

A magnetized nano‐photocatalyst based on TiO2/magnetic graphene was developed for efficient photodegradation of crystal violet (CV). Scanning electron microscopy, X‐ray diffraction, energy‐dispersive X‐ray spectroscopy and elemental mapping were used to characterize the prepared magnetic nano‐photocatalyst. The photocatalytic activity of the synthesized magnetic nano‐photocatalyst was evaluated using the decomposition of CV as a model organic pollutant under UV light irradiation. The obtained results showed that TiO2/magnetic graphene exhibited much higher photocatalytic performance than bare TiO2. Incorporation of graphene enhanced the activity of the prepared magnetic nano‐photocatalyst. TiO2/magnetic graphene can be easily separated from an aqueous solution by applying an external magnetic field. Effects of pH, magnetized nano‐photocatalyst dosage, UV light irradiation time, H2O2 amount and initial concentration of dye on the photodegradation efficiency were evaluated and optimized. Efficient photodegradation (>98%) of the selected dye under optimized conditions using the synthesized nano‐photocatalyst under UV light irradiation was achieved in 25 min. The prepared magnetic nano‐photocatalyst can be used in a wide pH range (4–10) for degradation of CV. The effects of scavengers, namely methanol (OH• scavenger), p‐benzoquinone (O2•− scavenger) and disodium ethylenediaminetetraacetate (hole scavenger), on CV photodegradation were investigated.
A nondisruptive reliability approach to assess the health of microseismic sensing networks
Authors: Neira D. , Soto G. , Fontbona J. , Prado J. , Gaete S.
Published: August 2017

Microseismic sensing networks are important tools for the assessment and control of geomechanical hazards in underground mining operations. In such a setting, the maintenance of a healthy network, that is, one that accurately registers all microseisms above some minimum energy level with acceptable levels of noise, is crucially relevant.

In this paper, we develop a nondisruptive method to monitor the health of such a network, by associating with each sensor a set of performance indexes, inspired from reliability engineering, which are estimated from the set of registered signals. Our method addresses 2 relevant features of each of the sensors' behavior, namely, what type of noise is or might be affecting the registering process, and how effective at registering microseisms the sensor is.

The method is evaluated through a case study with microseismic data registered at the Chilean underground mine El Teniente. This study illustrates our method's capability to discriminate and rank sensors with satisfactory, poor, or defective sensing performances, as well as to characterize their failure profile or type, an information that can be used to plan or optimize the network maintenance procedures.
REFUND: Untersuchung von Bestandsgründungen für eine Entscheidung zur Wiedernutzung
Authors: Niederleithinger Ernst , Katzenbach Rolf , Klingmüller Oswald , Hillmann Stephan , Willmes Michael
Published: August 2017

Vor einer geplanten Weiter‐ oder Wiedernutzung von Bestandsgründungen stellt sich die Frage nach deren Lage, Geometrie und Zustand im Untergrund. Hierfür gibt es verschiedene Prüfverfahren. Die Abläufe bei Planung und Prüfung sind jedoch bisher nicht standardisiert und die Möglichkeiten bzw. Grenzen der Prüfverfahren den Planern wenig bekannt. Im Forschungsprojekt REFUND (2014–2016) wurden unter Berücksichtigung der aktuellen Normen und des Stands der Technik Ablaufdiagramme für die Planung der Wiedernutzung sowie die Untersuchung des Bestands entwickelt. Dies geschah getrennt für Einzel‐ und Streifenfundamente, Platten und Pfähle. An zwei Praxisbeispielen wurden die Abläufe getestet und optimiert. Die Ergebnisse wurden in einem Handbuch zusammengefasst. Es soll Planer und andere Verantwortliche bei der wirtschaftlich und technisch optimierten Durchführung von Wiedernutzungsprojekten unterstützen.
Erfahrungen mit wasserabführenden Schalungsbahnen an der zweiten Schleuse Trier
Authors: Müller Hilmar , Mertes Raymund , Kanther Christian
Published: August 2017

Beim Bau der zweiten Schleuse Trier wurden die Kammerwandoberflächen in Teilbereichen mit konventioneller, saugender Schalhaut, in anderen Bereichen unter Verwendung einer wasserabführenden Schalungsbahn hergestellt. Die Bauausführung mit der wasserabführenden Schalungsbahn wies gegenüber der saugenden Schalung deutliche Vorteile auf. Die Eigenschaften der Betonrandzone, wie Festigkeit und Dichtigkeit, konnten deutlich verbessert werden. Mit den verbesserten Oberflächeneigenschaften werden eine höhere Dauerhaftigkeit sowie Erleichterungen bei der Unterhaltung erwartet.

Die Ausführung mit der zusätzlich aufzubringenden Schalungsbahn bedeutete einen zusätzlichen Aufwand, der aber durch kürzere Nachbehandlungszeiten und deutlich geringere Nacharbeiten weitgehend wieder kompensiert wurde.
Das Archaellum
Authors: Hoffmann Lena , Albers Sonja‐Verena
Published: August 2017

Archaeen bilden eine der drei Domänen des Lebens. Obwohl sie auf den ersten Blick Bakterien sehr ähneln, sind sie in manchen Prozessen wie Transkription und Translation den Eukaryoten viel ähnlicher. Alle drei Domänen des Lebens haben völlig verschiedene Formen der Bewegung entwickelt. Während Bakterien zum Schwimmen das Flagellum benutzen, schwimmen Eukaryoten mittels Cilien, die aus Mikrotubuli aufgebaut sind. Die Archaeen dahingegen haben das Archaellum entwickelt. Diese Struktur ist evolutionär mit Typ IV‐Pili verwandt, da es ähnlich assembliert wird. Im Gegensatz zu diesen kann das Archaellum rotieren, um die Zellen fortzubewegen. In diesem Artikel geben wir einen kurzen Einblick in die Entdeckung der Archaeen sowie aktuelle spannende Entwicklungen und beschreiben, was wir über das Archaellum als faszinierendes Motilitätsorganell wissen.
Naturapotheke Mistel
Authors: Pfüller Uwe , Stürken Christine
Published: August 2017

Die Mistel, ein auf Bäumen wachsender, immergrüner Halbschmarotzer, beeindruckt mit ihrer einzigartigen Erscheinung, ihrer weltweiten Verbreitung und der Vielfalt ihrer Inhalts‐ und Wirkstoffe. Erst in der Neuzeit fand die Mistel mit ihren Wirkstoffen den Weg in die unkonventionelle und schließlich in die molekulare Medizin. Das Wirkstoffspektrum wird anhand der umfassend erforschten Europäischen Mistel (Viscum album) dargestellt.
Seeigel und ihre Beutegreifer im Mittelmeer
Authors: Sievers Diedrich
Published: August 2017

Seeigel sind eine beliebte Beute und trotz unterschiedlicher Schutzanpassungen gelingt es Räubern, diese Verteidigung zu überwinden. Im Mittelmeer machen vor allem wirbellose Tiere, etwa Helmschnecken, Krebse und Seesterne, aber auch verschiedene Fische Jagd auf Seeigel. Helmschnecken verkleben die Stacheln und Pedicellarien mit Schleim und bohren das Kalkskelett der Seeigel mit Hilfe von Schwefelsäure an. Große Krebse, etwa Langusten und Seespinnen, brechen den Panzer der Seeigel mit ihren Laufbeinen oder Scheren auf. Seesterne nehmen kleine Seeigel entweder direkt mit dem Magen auf oder stülpen ihren Magen nach außen, um Seeigel zu verdauen. Fische, vor allem Meerbrassen, beißen zuerst die schützenden Stacheln ab und brechen den Panzer des Seeigels mit ihrem spezialisierten Gebiss auf. Zum Teil bleiben dabei Spuren auf den Skeletten der erbeuteten Seeigel zurück, etwa Bohrlöcher, Kratzspuren, Zahnabdrücke und Bruchmuster, die es ermöglichen, das Geschehen zu rekonstruieren.
Artenkenntnis einheimischer Vögel
Authors: Gerl Thomas , Hollweck Ernst , Almer Johannes , Herden Michael
Published: August 2017

Da Schüler nur noch sehr wenige einheimische Vogelarten bestimmen können, wurden in einem fächerübergreifenen Ansatz Unterrichtsmaterialien entwickelt, um ihre Artenkenntnis zu verbessern und sie dazu zu befähigen, am Beispiel der Vögel eigene Naturbeobachtungen durchzuführen. Dabei wendet sich der Fokus von der intensiven exemplarischen Studie eines einzelnen Vogels über die Nutzung spielerischer Online‐Bestimmungsübungen hin zu einem breiten Überblick über die Vielfalt der Arten, um diesen Grundstock an Formenkenntnis schließlich bei eigenen Freilanduntersuchungen anzuwenden.
Pathogene Bakterien in Do‐it‐yourself Gentechnikbaukästen
Authors: Köhler Nina , Stellberger Thorsten , Pavlovic Melanie , Messelhäußer Ute , Hörmansdorfer Stefan , Dinkelmeier Anna , Busch Ulrich , Baiker Armin
Published: August 2017

Das Bayerische Landesamt für Gesundheit und Lebensmittelsicherheit (LGL) hat einen über das Internet frei bestellbaren Gentechnik‐Baukasten der Firma „The Odin“ (USA) mit dem Namen „The CRISPR Cas 9 Bacterial Genomic Editing Kit“ bestellt und untersucht – und dabei festgestellt, dass darin eine Mischkultur aus verschiedenen, potenziell pathogenen Arten enthalten ist.
Zwei Menschenarten werden zu Zeitgenossen
Authors: Sander Johannes
Published: August 2017

Viele Fragen zur Evolutionsgeschichte des Menschen sind nach wie vor ungeklärt ‐ Überraschungen sind jederzeit möglich. So konnten jetzt Fossilien aus Marokko, die eine frühe Form des anatomisch modernen Menschen repräsentieren, auf ein Alter von etwa 315.000 Jahren datiert werden. Damit sind sie deutlich älter als gedacht und geben somit Aufschluss über die frühe Evolution des Homo sapiens. Da fast zeitgleich das Alter der rätselhaften Menschenart Homo naledi ebenfalls auf rund nur 300.000 Jahre datiert wurde, besteht die Möglichkeit, dass sich die Vertreter beider Arten sogar getroffen haben.
25 Jahre Deutsches Institut für Ernährungsforschung Potsdam‐Rehbrücke (DIfE)
Authors: Levit Georgy S. , Hoßfeld Uwe , Olias Gisela , Grune Tilman
Published: August 2017

Bei all den Diskussionen um Ernährung wird oft verkannt, dass es nicht nur eine Art gibt, sich gesund zu ernähren. Doch was gehört zu einer gesunden Nahrungsaufnahme dazu? Dieser Frage geht ein in Deutschland einzigartiges Institut nach, das im Herbst 2017 sein 25‐jähriges Jubiläum feiert: das Deutsche Institut für Ernährungsforschung Potsdam‐Rehbrücke (DIfE).
Nachrichten des Verbandes Biologie, Biowissenschaften & Biomedizin in Deutschland
Authors: Schuh Sabine
Published: August 2017

Wissenschaft & Gesellschaft

Grundsatzposition Tierversuche

Bundestagswahl 2017

Fachgesellschaften

Finanzierung von Jahrestagungen

Landesverbände

Bayern

Hessen

Arbeitskreise

BTA‐Ausbildung

Veranstaltungen
Von Pathologen und Himmelstüren
Authors: Hauk Andrea
Published: August 2017

Nachwuchs! Es wird viel diskutiert über die Vereinbarkeit von Familie und Beruf. Andrea Hauk – BIUZ‐Lesern bekannt als Autorin der Laborseite – hat den Praxistest gemacht und berichtet im vierten Teil unserer Reihe von ihren Erfahrungen.
Das Kamel: Lastenträger und Entwicklungshelfer
Authors: Eitner Pascal , Tetsch Larissa
Published: August 2017

Auch wenn die Passgänger auf uns exotisch wirken, gehören sie in anderen Kulturen zu den prägenden Nutztieren. Kamele sind nicht nur unverzichtbare Zug‐ und Lasttiere in Trockengebieten, sondern werden zunehmend für die Lebensmittelproduktion und sogar zur Freizeitgestaltung eingesetzt. Mittlerweile sind sie auch ein Quell neuartiger Wirkstoffe.
Versatile chromatographic method for catechin determination in development of topical formulations containing natural extracts
Authors: Ferreira‐Nunes Ricardo , Angelo Tamara , da Silva Sandra Márcia Mazutti , Magalhães Pérola Oliveira , Gratieri Tais , da Cunha‐Filho Marcílio Sérgio Soares , Gelfuso Guilherme Martins
Published: August 2017

Catechin is found in several natural sources, as Eugenia dysenterica and Syzygium cumini extracts. Its antioxidant and UV‐protective properties suggest a potential use in cosmetic and dermatological formulations. A simple analytical method capable of giving support to experiments performed along the development of topical formulations containing this natural substance (i.e. drug assay, skin permeation and stability studies), however, is still needed. Thus, this work aimed to develop and validate a selective HPLC method for catechin determination during the development of topical formulations. Separation was achieved using an RP‐C18 column (300 × 3.9 mm; 10 μm), with a mobile phase of methanol–phosphoric acid 0.01 m (15: 85, v/v), a flow rate of 0.8 mL/min, temperature set at 40°C and UV detection at 230 nm. The method was linear in a range from 0.5 to 10.0 μg/mL (r = 0.9998), precise with an overall variation coefficient of 5.5% and accurate with catechin recovery from the skin layers >85%. Additionally, the method was sensitive (limit of detection, 0.109 μg/mL; limit of quantification, 0.342 μg/mL) and selective against plant extracts, skin matrices and formulation interferents, as well as catechin degradation products. It was also robust regarding both methodology parameters and analytical stability.
LC‐ESI‐MS/MS determination of 4‐methylpyrazole in dog plasma and its application to a pharmacokinetic study in dogs
Authors: Chandrasekhar Devaraj V. , Suresh Ponnayyan Sulochana , Dittakavi Sreekanth , Hiremath Rakesh A. , Bhamidipati Ravi Kanth , Richter Wolfgang , Srinivas Nuggehally R. , Mullangi Ramesh
Published: August 2017

A simple, specific, sensitive and rapid LC‐ESI‐MS/MS method has been developed and validated for the quantification of 4‐methylpyrazole in dog plasma using N‐methylnicotinamide‐d4 as an internal standard (IS) as per regulatory guidelines. Sample preparation was accomplished through a simple protein precipitation. Chromatographic separation of 4‐methylpyrazole and the IS was performed on a monolithic (Chromolith RP18e) column using an isocratic mobile phase comprising 0.2% formic acid in water and acetonitrile (20:80, v/v) at a flow rate of 1.0 mL/min. Elution of 4‐methylpyrazole and the IS occurred at ~1.60 and 1.56 min, respectively. The total chromatographic run time was 3.2 min. A linear response function was established in the concentration range of 4.96–4955 ng/mL. The intra‐ and inter‐day accuracy and precision were in the ranges 1.81–12.9 and 3.80–11.1%, respectively. This novel method has been applied to a pharmacokinetic study in dogs.
A meta‐analysis: microRNAs’ prognostic function in patients with nonsmall cell lung cancer
Authors: Yu Na , Zhang Qingjun , Liu Qing , Yang Jiayu , Zhang Sheng
Published: August 2017

Accumulating papers have demonstrated that microRNAs play an important role in the progression of lung cancer, mainly as oncogenic and tumor suppressive. Therefore, microRNAs may influence the survival of lung cancer patients. In this meta‐analysis, we evaluated the role of microRNAs in affecting the overall survival in nonsmall cell lung cancer (NSCLC) patients, which may provide valuable information for the treatment of nonsmall cell lung cancer. We used keywords to retrieve literatures from online databases PUBMED, EMBASE and Web of Science and included 12 studies into our investigation according to pre‐set criteria. Then, we analyzed the data with stata13.1 to evaluate the microRNAs role on the prognosis of NSCLC patients. NSCLC patients with higher microRNAs expression levels tend to show lower overall survival. HR (hazard ratio): 2.49, 95% CI (confidence interval): 1.84–3.37. Besides, both oncogenic and tumor suppressive microRNAs have an evident influence on prognosis with HR values of 2.60 (95% CI: 2.12–3.19) and 0.41 (95% CI: 0.05–0.34), respectively. microRNAs, especially from tissue, have an influence on overall survival of NSCLC patients, which indicates that microRNAs could serve as potential prognostic markers for NSCLC and may provide a treatment strategy for advanced NSCLC patients.
Prosthetic rehabilitation of edentulous hemimandibulectomy patient: a clinical report
Authors: Sahu Shailendra Kumar , Motwani B.K. , Dani Anurag
Published: August 2017

Key Clinical Message

Surgical resection of mandible causes deviation of mandible toward affected side, resulting in loss of occlusal contact. This article presents twin rows of nonanatomic teeth on the untreated side of maxillary complete denture. The palatal row helps in mastication, whereas the buccal row supports the cheeks and improves the aesthetics.
Systemic BCG‐osis following intravesical BCG instillation for bladder carcinoma
Authors: Liaw Frank , Tan Yan Yu , Hendry David
Published: August 2017

Key Clinical Message

Intravesical instillation of Bacillus Calmette‐Guérin (BCG) has been shown to be an effective form of immunotherapy for bladder cancer. This case report describes a patient who develops systemic BCG‐osis following intravesical BCG instillation and demonstrates the importance of being aware of more severe complications associated with BCG immunotherapy.
Mechanisms of Two‐Electron versus Four‐Electron Reduction of Dioxygen Catalyzed by Earth‐Abundant Metal Complexes
Authors: Fukuzumi Shunichi , Lee Yong‐Min , Nam Wonwoo
Published: August 2017

The two‐electron reduction of dioxygen with two protons produces hydrogen peroxide, which is directly used as a liquid fuel in hydrogen peroxide fuel cells, whereas the four‐electron reduction of dioxygen is combined with the two‐electron oxidation of hydrogen in hydrogen fuel cells. Platinum (Pt)‐based nanocomposites are the most efficient commercial electrocatalysts for the oxygen reduction reaction (ORR). However, the poor stability, scarcity and high cost of these Pt‐based oxygen electrocatalysts are major barriers for the large‐scale implementation of fuel cell technologies. Replacing noble metal‐based electrocatalysts with highly efficient and inexpensive earth‐abundant metal‐based oxygen electrocatalysts has been of critical importance for practical applications. To develop efficient catalysts for the two‐electron and four‐electron reduction of dioxygen, it is crucially important to clarify the catalytic mechanisms of two‐electron/two‐proton versus four‐electron/four‐proton reduction of dioxygen with earth‐abundant metal complexes. This review focused on the factors that control the two‐electron/two‐proton versus four‐electron/four‐proton reduction of dioxygen by electron donors (one electron reductants) such as ferrocene, catalyzed by earth‐abundant metal complexes such as iron, cobalt, copper, manganese and nickel complexes in the homogeneous phase, by detecting catalytic intermediates, which determine the catalytic pathways of the two‐electron versus four‐electron reduction of dioxygen. The electrocatalytic two‐electron or/and four‐electron reduction of dioxygen with earth‐abundant metal complexes and metal oxides has also been discussed in relation with the homogeneous catalysis.
Voltammetric, Spectroscopic, and Microscopic Investigation of the Oxidation of Solid and Solution Phases of Tetrathiafulvalene (TTF) to (TTF)2MO4(M=Mo, W)
Authors: Ahmed Shaimaa M. , Bond Alan M. , Martin Lisandra L.
Published: August 2017

The diffusion‐controlled solid−solid‐state transformation of TTF to (TTF)2MoO4and (TTF)2WO4is reported at TTF‐modified glassy carbon, indium tin oxide (ITO), Au, and Pt electrodes in contact with aqueous MoO42−or WO42−electrolytes. Electrocrystallization of (TTF)2MoO4and (TTF)2WO4onto the electrode surface also was achieved by oxidation of TTF to TTF+in the presence of Na2MoO4and Na2WO4in the mixed CH3CN/H2O (90 : 10 v/v) solvent containing 0.1 M Bu4NPF6as the supporting electrolyte. Mechanistic aspects of the solid−solid state interconversion reactions and electrocrystallization have been probed by using cyclic voltammetry, chronoamperometry, electrochemical quartz crystal microbalance (EQCM), and electrochemical surface plasmon resonance (ESPR), whereas the morphology of the electrocrystallized materials was established by using scanning electron microscopy (SEM). Vibrational (IR, Raman) and UV/Vis spectroscopic methods, as well as other techniques, were used to establish that the products of electrooxidation are (TTF)2MoO4and (TTF)2WO4.
Kinetics of the Reduction of Ruthenium Hexaammine at Bismuth Electrodes in Aqueous Solution: Analyzing the Potential Dependence of the Transfer Coefficient
Authors: Nomor Aondoakaa S. , Horrocks Ben R.
Published: August 2017

The reduction of Ru(NH3)63+ at Bi electrodes in aqueous KCl is much slower than at Pt electrodes. Differential capacitance and ex situ photoemission spectra indicate the presence of a thin oxide layer about 1.5 nm thick on the Bi surface near the formal potential of −0.217 V vs Ag/AgCl/1 M KCl(aq). Despite the presence of this oxide, reproducible impedance spectra near the formal potential were obtained for Ru(NH3)63+ that could be analyzed by using a Randles circuit modified to incorporate a constant phase element. The value of the standard rate constant was 1.47±0.44×10−3 cm s−1. Under the same conditions, impedance spectra for Pt/Ru(NH3)63+ were reversible up to the highest frequencies (105 Hz) employed. The charge‐transfer resistance−dc potential curves obtained from the impedance spectra were fitted by a regression model, which contained no a priori assumption about the potential dependence of the transfer coefficient except piecewise linearity. The measured transfer coefficients show clear evidence of diffuse layer effects, but, in addition, an increase in transfer coefficient at the most negative potentials studied was observed and interpreted in terms of the reduction and thinning of the anodic oxide.
Ambivalence and guilt feelings: Two relevant variables for understanding caregivers' depressive symptomatology
Authors: Losada Andrés , Márquez‐González María , Vara‐García Carlos , Gallego‐Alberto Laura , Romero‐Moreno Rosa , Pillemer Karl
Published: August 2017

Providing care for a relative with dementia is considered to be a chronic stressor that has been linked to negative mental health consequences for caregivers. A theoretical model was developed and tested to assess the degree to which ambivalence and guilt feelings contribute to caregivers' depressive symptomatology. Participants included 212 dementia family caregivers. In addition to ambivalence and guilt feelings, sociodemographic characteristics, behavioural and psychological symptoms of dementia, and depressive symptomatology were assessed. Hypotheses derived from the stress and coping model were tested using path analysis. The analysed model showed an excellent fit to the data. In total, 35% of the variance in depressive symptomatology was explained by the assessed variables. Although significant correlations were obtained between frequency and appraisal of behavioural and psychological symptoms of dementia and depression, the obtained model suggests that this effect was mediated through ambivalence. In addition, ambivalence had an indirect effect on depression. The association of ambivalence with depression was explained through feelings of guilt; that is, respondents who reported ambivalent feelings were more likely to experience guilt, leading in turn to greater depressive symptomatology. The findings suggest that dementia caregivers' ambivalence and guilt feelings are relevant for understanding their depressive symptomatology. These factors should be addressed in psychological interventions with caregivers.
Financial Auditor and Sustainability Reporting: Does it matter?
Authors: Fernandez‐Feijoo Belen , Romero Silvia , Ruiz Silvia
Published: August 2017

The objective of this paper is to investigate the yet‐to‐develop assurance market, its links with the mature auditing market, and the role that the Big4 auditing firms (KPMG, EY, PwC, and Deloitte) play in the former. We use data submitted to the Global Reporting Initiative by companies in 18 countries, for the years 2011–2013, in order to obtain a global overview that allows generalization of the results. We find higher levels of disclosure and increased credibility of sustainability reports (SRs) when the financial auditor is a Big4. Companies audited by a Big4 are more likely to assure the SR than those audited by a non‐Big4. Our paper confirms the connection between financial auditor and assurer of SR provider in an international setting: the choice of a Big4 as a financial auditor is a driver for the choice of a Big4 as an assurer provider, suggesting a potential competitive advantage. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment
Reducing the Cost of Zinc–Oxygen Batteries by Oxygen Recycling
Authors: Yan Zhao , Gao Jianxin , Liu Min , Wang Erdong , Sun Gongquan
Published: August 2017

With the increasing demand of energy storage towards increasing the use of renewable energy technologies, electrochemical systems with low cost, high safety levels, and low environmental impact are critically needed. Zinc–air/oxygen batteries, which were always considered to be cheap, are losing their competitive advantages due to poor cyclic performance and energy efficiency. Herein, an effective strategy for oxygen recycling, which reduces the cost of oxygen to as low as ¢ 0.2 kWh−1 per cycle, is reported. With the use of oxygen, the performance of zinc–oxygen batteries is largely increased, with a maximum power density of 290 mW cm−2, stable cycling for more than 1500 cycles, an average energy density of 60 %, and elimination of carbonates. A 1 kW/1 kWh zinc–oxygen battery system is also integrated and exhibits a satisfactory energy efficiency of 58 % and a high working power density of 75 mW cm−2.
A new model for spectral velocity ordinates at long periods
Authors: Samdaria Nikhil , Gupta Vinay K.
Published: August 2017

The estimation of peak linear response via elastic design (response) spectra continues to form the basis of earthquake‐resistant design of structural systems in various codes of practice all over the world. Many response spectrum‐based formulations of peak linear response require an additional input of the spectral velocity (SV) ordinates consistent with the specified seismic hazard. SV ordinates have been conventionally approximated by pseudo spectral velocity (PSV) ordinates, which are close to the SV ordinates only over the intermediate frequency range coinciding with the velocity‐sensitive region. At long periods, PSV ordinates underestimate the SV ordinates, and this study proposes a formulation of a correction factor (>1) that needs to be multiplied by the PSV ordinates in order to close the gap between the two sets of ordinates. A simple model is proposed in the form of a power function in oscillator period to estimate this factor in terms of two governing parameters which are in turn estimated from two single‐parameter scaling equations. The parameters considered for the scaling equations are (1) the period at which the PSV spectrum is maximized and (2) the rate of decay of the pseudo spectral acceleration (PSA) amplitudes at long periods. For a given damping ratio, four regression coefficients are determined for the scaling equations with the help of 205 ground motions recorded in western USA. A numerical study undertaken with the help of several design PSA spectra and ensembles of spectrum‐compatible ground motions illustrates the effectiveness of the proposed correction factor, together with the proposed scaling models, in comparison with the PSV approximation in a variety of design situations. Both the input parameters mentioned above can be easily obtained from the specified design spectrum, and thus the proposed model is convenient to use.
Peat depth as a control on moss water availability under evaporative stress
Authors: Dixon Simon J. , Kettridge Nicholas , Moore Paul A. , Devito Kevin J. , Tilak Amey S. , Petrone Richard M. , Mendoza Carl A. , Waddington James M.
Published: August 2017

Northern peatlands are a vital component of the global carbon cycle, containing large stores of soil organic carbon and acting as a long‐term carbon sink. Moss productivity is an important factor in determining whether these wetlands will retain this function under future climatic conditions. Research on unsaturated water flow in peatlands, which controls moss productivity during periods of evaporative stress, has focused on relatively deep bog systems. However, shallower peatlands and marginal connective wetlands can be essential components of many landscape mosaics. In order to better understand factors influencing moss productivity, water balance simulations using HYDRUS‐1D were run for different soil profile depths, compositions, and antecedent moisture conditions. Our results demonstrate a bimodal distribution of peatland realizations, either primarily conserving water by limiting evapotranspiration or maximizing moss productivity. For sustained periods of evaporative stress, both deep water storage and a shallow initial water table delay the onset of high vegetative stress, thus maximizing moss productivity. A total depth of sand and peat of 0.8 m is identified as the threshold above which increasing peat depth has no effect on changing vegetative stress response. In contrast, wetlands with shallow peat deposits (less than 0.5 m thick) are least able to buffer prolonged periods of evaporation due to limited labile water storage and will thus quickly experience vegetative stress and so limit evaporation and conserve water. With a predicted increase in the frequency and size of rain events in continental North America, the moss productivity of shallow wetland systems may increase, but also greater moisture availability will increase the likelihood they remain as wetlands in a changing climate.
Modelling of colloidal particle and heavy metal transfer behaviours during seawater intrusion and refreshing processes
Authors: Tan Bo , Liu Shuguang , Dai Chaomeng , Zhou Hui , Hui Zhenquan , Zhong Guihui , Zhang Hong
Published: August 2017

The proper management of coastal aquifers commonly requires an understanding of regional mass flow and complete seawater–freshwater circulation. In this study, time series observations of seawater intrusion and refreshing were conducted using a column experiment based on natural flow conditions in coastal groundwater and a sampled medium from a coastal sandy aquifer without chemical treatment. Ranges of hydrodynamic and hydrochemical variables were tested and analysed. The results showed that the zeta potential of suspended colloids in aqueous solution in an aquifer polluted with 0.5 g/kg of heavy metals exhibited an isoelectric point for pH values ranging from 5.70 to 6.07 when freshwater or seawater completely occupied the aquifer pores, which is representative of natural hydrochemical conditions. In this scenario, a high background concentration of heavy metals induced colloidal immobilization. Otherwise, seawater–freshwater circulation enabled colloid mobilization due to ionic strength and pH fluctuations. The migration of multiple heavy metals occurred at a characteristic time of approximately 1 pore volume after each intrusion stage began and when the peak rate of colloid release was reached. At these times, the colloid behaviour determined the quantity and pathway of heavy metal transport. On the basis of the influences of seawater and freshwater interactions, the quantity of mobilized particles generally decreased and was uniformly distributed in each fraction due to particle loss and decreased porous connectivity. We speculate that the decrease in the total surface area of the migratory colloids may cause colloid‐associated heavy metal transport to decrease. The experimental results provide a useful basis for testing coastal groundwater flow and mass transport models because these phenomena require full characterization to precisely evaluate the associated fluxes from the field scale to the microscopic dimension.
The cadmium tolerance in Saccharomyces cerevisiae depends on inorganic polyphosphate
Authors: Trilisenko Ludmila , Kulakovskaya Ekaterina , Kulakovskaya Tatiana
Published: August 2017

The sensitivity to cadmium (Cd(II)), an important environmental pollutant, was studied in the cells of Saccharomyces cerevisiae strains with genetically altered polyphosphate metabolism. The strains overproducing polyphosphatases PPX1 or PPN1 were more sensitive to Cd(II) than the parent strain. The half maximal inhibitory concentrations were 0.02 and 0.05 mM for the transformants and the parent strain, respectively. Transformant strains cultivated in the presence of Cd(II) show a decrease in the content of short‐chained cytosolic acid soluble polyphosphate. The role of this polyphosphate fraction in detoxification of heavy metal ions is discussed.
Terahertz Thermometry: Combining Hyperspectral Imaging and Temperature Mapping at Terahertz Frequencies
Authors: Naccache Rafik , Mazhorova Anna , Clerici Matteo , Piccoli Riccardo , Khorashad Larousse Khosravi , Govorov Alexander O. , Razzari Luca , Vetrone Fiorenzo , Morandotti Roberto
Published: August 2017

The accurate and non‐invasive determination of multiple physical parameters, with well‐defined spatial resolution, is crucial for applications in manufacturing, chemistry, medicine and biology. Specifically, the ability to simultaneously measure both temperature and spectral signatures is still experimentally unavailable. To this end, we propose a mapping technique for biological systems, which exploits a linear correlation between terahertz wave reflectivity and temperature, and allows to spatially and spectrally resolve thermal distributions. This method is applied to a model biological system in two relevant cases where in one example, nanoplasmonic‐induced photothermal effects are imaged gaining new insights into collective heating phenomena. In the second example, we demonstrate a joint thermal‐hyperspectral imaging approach to chemically map the presence of a model drug formulation and simultaneously investigate its thermal stability in our biological system. This concept can be easily extended and widely applied to all materials that demonstrate a measurable change in their dielectric properties.
Theory of Self‐pulsing in Photonic Crystal Fano Lasers
Authors: Rasmussen Thorsten S. , Yu Yi , Mork Jesper
Published: August 2017

Laser self‐pulsing was a phenomenon exclusive to macroscopic lasers until recently, where self‐starting laser pulsation in a microscopic photonic crystal Fano laser was reported. In this paper a theoretical model is developed to describe the Fano laser, including descriptions of the highly‐dispersive Fano mirror, the laser frequency and the threshold gain. The model is based upon a combination of conventional laser rate equations and coupled‐mode theory. The dynamical model is used to demonstrate how the laser has two regimes of operation, continuous‐wave output and self‐pulsing, and these regimes are characterised using phase diagrams, establishing the regime of self‐pulsing numerically. Furthermore, the physics behind the self‐pulsing mechanism are explained in detail and it is demonstrated how cavity absorption makes the Fano mirror function as a saturable absorber, leading to Q‐switched pulse generation. A stability analysis is used to demonstrate how the dominant mechanism of instability is relaxation oscillations becoming un‐damped. Finally the effect of varying key self‐pulsing parameters is investigated by characterisation of the change in self‐pulsing regions.