bluuebunny/crossref_metadata_2025 huggingface dataset:
Patterns of glacier ablation acrossNorth‐CentralChile: Identifying the limits of empirical melt models under sublimation‐favorable conditions
Authors: Ayala A. , Pellicciotti F. , MacDonell S. , McPhee J. , Burlando P.
Published: June 2017

We investigate the energy balance and ablation regimes of glaciers in high‐elevation, dry environments using glaciometeorological data collected on six glaciers in the semiarid Andes of North‐Central Chile (29–34°S, 3127–5324 m). We use a point‐scale physically based energy balance (EB) model and an enhanced Temperature‐Index (ETI) model that calculates melt rates only as a function of air temperature and net shortwave radiation. At all sites, the largest energy inputs are net shortwave and incoming longwave radiation, which are controlled by surface albedo and elevation, respectively. Turbulent fluxes cancel each other out at the lower sites, but as elevation increases, cold, dry and wind‐exposed conditions increase the magnitude of negative latent heat fluxes, associated with large surface sublimation rates. In midsummer (January), ablation rates vary from 67.9 mm w.e. d−1at the lowest site (∼100% corresponding to melt), to 2.3 mm w.e. d−1at the highest site (>85% corresponding to surface sublimation). At low‐elevation, low‐albedo, melt‐dominated sites, the ETI model correctly reproduces melt using a large range of possible parameters, but both the performance and parameter transferability decrease with elevation for two main reasons: (i) the air temperature threshold approach for melt onset does not capture the diurnal variability of melt in cold and strong irradiated environments and (ii) energy losses decrease the correlation between melt and net shortwave radiation. We summarize our results by means of an elevation profile of ablation components that can be used as reference in future studies of glacier ablation in the semiarid Andes.
Transient slab flattening beneath Colombia
Authors: Wagner L. S. , Jaramillo J. S. , Ramírez‐Hoyos L. F. , Monsalve G. , Cardona A. , Becker T. W.
Published: June 2017

Subduction of the Nazca and Caribbean Plates beneath northwestern Colombia is seen in two distinct Wadati Benioff Zones, one associated with a flat slab to the north and one associated with normal subduction south of 5.5°N. The normal subduction region is characterized by an active arc, whereas the flat slab region has no known Holocene volcanism. We analyze volcanic patterns over the past 14 Ma to show that in the mid‐Miocene a continuous arc extended up to 7°N, indicating normal subduction of the Nazca Plate all along Colombia's Pacific margin. However, by ~6 Ma, we find a complete cessation of this arc north of 3°N, indicating the presence of a far more laterally extensive flat slab than at present. Volcanism did not resume between 3°N and 6°N until after 4 Ma, consistent with lateral tearing and resteepening of the southern portion of the Colombian flat slab at that time.
Heat flow, heat production, and crustal temperatures in the Archaean Bundelkhand craton, north‐central India: Implications for thermal regime beneath the Indian shield
Authors: Podugu Nagaraju , Ray Labani , Singh S. P. , Roy Sukanta
Published: June 2017

Heat flow and heat production data sets constrain the crustal thermal structure in the 2.5–3.5 Ga Bundelkhand craton, the oldest cratonic core in northern Indian shield, for the first time and allow comparisons with the southern Indian shield. Temperature measurements carried out in 10 boreholes at five sites in the craton, combined with systematic thermal conductivity measurements on major rock types, yield low heat flow in the range of 32–41 mW m−2, which is distinct from the generally high heat flow reported from other parts of the northern Indian shield. Radioelemental measurements on 243 samples of drill cores and outcrops reveal both large variability and high average heat production for the Neo‐Archaean to Palaeo‐Proterozoic granites (4.0 ± 2.1 (SD) μW m−3) relative to the Meso‐Archaean tonalite‐trondhjemite‐granodiorite (TTG) gneisses (2.0 ± 1.0 (SD) μW m−3). On the basis of new heat flow and heat production data sets combined with available geological and geophysical information, a set of steady state, heat flow‐crustal heat production models representative of varying crustal scenarios in the craton are envisaged. Mantle heat flow and Moho temperatures are found to be in the range of 12–22 mW m−2 and 290–420°C, respectively, not much different from those reported for the similar age Dharwar craton in southern India. This study reveals similar mantle thermal regimes across the northern and southern parts of the Indian shield, in spite of varying surface heat flow regimes, implying that much of the intraprovince and interprovince variations in the Indian shield are explained by variations in upper crustal heat production.
Real‐time prediction of the occurrence of GLE events
Authors: Núñez Marlon , Reyes‐Santiago Pedro J. , Malandraki Olga E.
Published: June 2017

A tool for predicting the occurrence of Ground Level Enhancement (GLE) events using the UMASEP scheme is presented. This real‐time tool, called HESPERIA UMASEP‐500, is based on the detection of the magnetic connection, along which protons arrive in the near‐Earth environment, by estimating the lag correlation between the time derivatives of 1 min soft X‐ray flux (SXR) and 1 min near‐Earth proton fluxes observed by the GOES satellites. Unlike current GLE warning systems, this tool can predict GLE events before the detection by any neutron monitor (NM) station. The prediction performance measured for the period from 1986 to 2016 is presented for two consecutive periods, because of their notable difference in performance. For the 2000–2016 period, this prediction tool obtained a probability of detection (POD) of 53.8% (7 of 13 GLE events), a false alarm ratio (FAR) of 30.0%, and average warning times (AWT) of 8 min with respect to the first NM station's alert and 15 min to the GLE Alert Plus's warning. We have tested the model by replacing the GOES proton data with SOHO/EPHIN proton data, and the results are similar in terms of POD, FAR, and AWT for the same period. The paper also presents a comparison with a GLE warning system.
Dynamic Corrosion and Material Characteristics of Mg–Zn–Zr Mini‐Tubes: The Influence of Microstructures and Extrusion Parameters
Authors: Lin Da‐Jun , Hung Fei‐Yi , Liu Heng‐Jui , Yeh Ming‐Long
Published: June 2017

In this study, magnesium–zinc–zirconium (Mg–Zn–Zr) alloy mini‐tubes that fit the diameter of cardiovascular stents are successfully fabricated using an isothermal extrusion method. The influence of extrusion temperature and ram speed on the microstructure are examined. In addition, this research develops a novel dynamic‐corrosion apparatus for Mg alloy mini‐tube examination, and supplemented with electrochemical, and biocompatibility tests, the optimal criteria for mini‐tube extrusion are defined. The optimized specimen not only retains a homogeneous fine‐grained structure with a grain size of about 2 µm, but also possesses 300 MPa yielding strength and nearly 15% elongation. Compared with a coarse‐grained microstructure, the fine‐grained specimens significantly reduces the corrosion and oxidation rates in a dynamic‐flow field, resulting in favorable characteristics of degradation, cytocompatibility, and hemocompatibility. The results suggest that precisely controlling the extrusion process can improve the mechanical properties as well as the biocompatibility of Mg alloys for application in cardiovascular implants.
Autonomous Integrated Microfluidic Circuits for Chip‐Level Flow Control Utilizing Chemofluidic Transistors
Authors: Frank Philipp , Gräfe David , Probst Christopher , Haefner Sebastian , Elstner Martin , Appelhans Dietmar , Kohlheyer Dietrich , Voit Brigitte , Richter Andreas
Published: June 2017

In microfluidics, a variety of platforms have emerged facilitating various physical effects for manipulating small volumes. Despite great functional diversity, most technologies are incapable of acting on direct feedback from the process liquid and instead require a sophisticated external control unit off‐chip. Here, a microfluidic platform concept is demonstrated utilizing the volume phase transition of polymers via transistor‐like components to actively switch between discrete fluid streams. Control is integrated at chip level for the first time, relying on information carried within the process liquid. Control commands are chemical signals such as solvent concentration, pH‐value, or even salt. The developed logical modules can be interconnected independently through conclusive signal propagation, supporting an integrated circuit concept and large‐scale integration. The approach enables the development of the basic logic gates (AND, OR, NOT) and their negated counterparts, as well as more sophisticated circuits such as an RS flip‐flop and a chemofluidic oscillator.
Flexible Organic/Inorganic Hybrid Near‐Infrared Photoplethysmogram Sensor for Cardiovascular Monitoring
Authors: Xu Huihua , Liu Jing , Zhang Jie , Zhou Guodong , Luo Ningqi , Zhao Ni
Published: June 2017

Wearable photoplethysmogram (PPG) sensors offer convenient and informative measurements for evaluating daily physiological states of individuals. In this work, epidermal and flexible near‐infrared (NIR) PPG sensors integrating a low‐power, high‐sensitivity organic phototransistor (OPT) with a high‐efficiency inorganic light‐emitting diode are developed. By exploiting an organic bulk heterojunction active layer and a bilayer gate dielectric design, a low voltage (<3 V) operated OPT with NIR responsivity as high as 3.5 × 105 A W−1 and noise equivalent power of 1.2 × 10−15 W Hz−1/2 is achieved, greatly surpassing commercial available silicon‐based photodetectors. In addition, the ultrathin encapsulation structure renders the device highly flexible and allows transfer printing of the device directly onto human skin. It is demonstrated that the epidermal/flexible PPG sensors are capable of continuously monitoring heart rate variability and precisely tracking the changes of pulse pressure at different postures of human subjects with the aid of electrocardiogram monitoring, exhibiting more reliable performance than commercial PPG sensors while consuming less power. The study suggests that the hybrid PPG sensor design may provide a promising solution for low‐power, real‐time physiological monitoring.
UV–Ozone Interfacial Modification in Organic Transistors for High‐Sensitivity NO2 Detection
Authors: Huang Wei , Zhuang Xinming , Melkonyan Ferdinand S. , Wang Binghao , Zeng Li , Wang Gang , Han Shijiao , Bedzyk Michael J. , Yu Junsheng , Marks Tobin J. , Facchetti Antonio
Published: June 2017

A new type of nitrogen dioxide (NO2) gas sensor based on copper phthalocyanine (CuPc) thin film transistors (TFTs) with a simple, low‐cost UV–ozone (UVO)‐treated polymeric gate dielectric is reported here. The NO2 sensitivity of these TFTs with the dielectric surface UVO treatment is ≈400× greater for [NO2] = 30 ppm than for those without UVO treatment. Importantly, the sensitivity is ≈50× greater for [NO2] = 1 ppm with the UVO‐treated TFTs, and a limit of detection of ≈400 ppb is achieved with this sensing platform. The morphology, microstructure, and chemical composition of the gate dielectric and CuPc films are analyzed by atomic force microscopy, grazing incident X‐ray diffraction, X‐ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy, revealing that the enhanced sensing performance originates from UVO‐derived hydroxylated species on the dielectric surface and not from chemical reactions between NO2 and the dielectric/semiconductor components. This work demonstrates that dielectric/semiconductor interface engineering is essential for readily manufacturable high‐performance TFT‐based gas sensors.
Chemo‐ and Enantioselective Intramolecular Silver‐Catalyzed Aziridinations
Authors: Ju Minsoo , Weatherly Cale D. , Guzei Ilia A. , Schomaker Jennifer M.
Published: June 2017

Asymmetric nitrene‐transfer reactions are a powerful tool for the preparation of enantioenriched amine building blocks. Reported herein are chemo‐ and enantioselective silver‐catalyzed aminations which transform di‐ and trisubstituted homoallylic carbamates into [4.1.0]‐carbamate‐tethered aziridines in good yields and with ee values of up to 92 %. The effects of the substrate, silver counteranion, ligand, solvent, and temperature on both the chemoselectivity and ee value were explored. Stereochemical models were proposed to rationalize the observed absolute stereochemistry of the aziridines, which undergo nucleophilic ring opening to yield enantioenriched amines with no erosion in stereochemical integrity.
Unsupported Pt‐Ni Aerogels with Enhanced High Current Performance and Durability in Fuel Cell Cathodes
Authors: Henning Sebastian , Ishikawa Hiroshi , Kühn Laura , Herranz Juan , Müller Elisabeth , Eychmüller Alexander , Schmidt Thomas J.
Published: June 2017

Highly active and durable oxygen reduction catalysts are needed to reduce the costs and enhance the service life of polymer electrolyte fuel cells (PEFCs). This can be accomplished by alloying Pt with a transition metal (for example Ni) and by eliminating the corrodible, carbon‐based catalyst support. However, materials combining both approaches have seldom been implemented in PEFC cathodes. In this work, an unsupported Pt‐Ni alloy nanochain ensemble (aerogel) demonstrates high current PEFC performance commensurate with that of a carbon‐supported benchmark (Pt/C) following optimization of the aerogel's catalyst layer (CL) structure. The latter is accomplished using a soluble filler to shift the CL's pore size distribution towards larger pores which improves reactant and product transport. Chiefly, the optimized PEFC aerogel cathodes display a circa 2.5‐fold larger surface‐specific ORR activity than Pt/C and maintain 90 % of the initial activity after an accelerated stress test (vs. 40 % for Pt/C).
Bismuth–Boron Multiple Bonding in BiB2O− and Bi2B−
Authors: Jian Tian , Cheung Ling Fung , Chen Teng‐Teng , Wang Lai‐Sheng
Published: June 2017

Despite its electron deficiency, boron is versatile in forming multiple bonds. Transition‐metal–boron double bonding is known, but boron–metal triple bonds have been elusive. Two bismuth boron cluster anions, BiB2O− and Bi2B−, containing triple and double B−Bi bonds are presented. The BiB2O− and Bi2B− clusters are produced by laser vaporization of a mixed B/Bi target and characterized by photoelectron spectroscopy and ab initio calculations. Well‐resolved photoelectron spectra are obtained and interpreted with the help of ab initio calculations, which show that both species are linear. Chemical bonding analyses reveal that Bi forms triple and double bonds with boron in BiB2O− ([Bi≡B−B≡O]−) and Bi2B− ([Bi=B=Bi]−), respectively. The Bi−B double and triple bond strengths are calculated to be 3.21 and 4.70 eV, respectively. This is the first experimental observation of Bi−B double and triple bonds, opening the door to design main‐group metal–boron complexes with multiple bonding.
Top‐Down Fabrication of Stable Methylammonium Lead Halide Perovskite Nanocrystals by Employing a Mixture of Ligands as Coordinating Solvents
Authors: Huang He , Xue Qi , Chen Bingkun , Xiong Yuan , Schneider Julian , Zhi Chunyi , Zhong Haizheng , Rogach Andrey L.
Published: June 2017

A top‐down method is demonstrated for the fabrication of CH3NH3PbBr3 and CH3NH3PbI3 perovskite nanocrystals, employing a mixture of ligands oleic acid and oleylamine as coordinating solvents. This approach avoids the use of any polar solvents, skips multiple reaction steps by employing a simple ultrasonic treatment of the perovskite precursors, and yields rather monodisperse blue‐, green‐, and red‐emitting methylammonium lead halide nanocrystals with a high photoluminescence quantum yield (up to 72 % for the green‐emitting nanocrystals) and remarkably improved stability. After discussing all relevant reaction parameters, the green‐emitting CH3NH3PbBr3 nanocrystals are employed as a component of down‐conversion white‐light‐emitting devices.
Integrated two‐stage adsorption for selective removal of CO2 and SO2 by amine‐functionalized SBA‐15
Authors: Wei L. , Gao Z. , Wang Y.
Published: June 2017

A novel process for integrated two‐stage selective removal of CO2 and SO2 from a simulated flue gas by an adsorption method was developed. Triethylolamine (TEA)‐loaded SBA‐15 was selected as the SO2 adsorbent, and tetraethylenepentamine (TEPA)‐loaded SBA‐15 was the CO2 adsorbent. Scanning electron microscopy, transmission electron microscopy, thermal gravimetric analysis, N2 adsorption/desorption, X‐ray photoelectron spectroscopy, and X‐ray diffraction techniques were used to characterize the properties of the adsorbents. The effects of the height–diameter ratio (H/D) of the adsorbent bed and operation temperature were tested for the removal of SO2. The results indicated that the pore volume and surface area of SBA‐15‐TEA‐50 and SBA‐15‐TEPA‐50 dropped with the increase of amine loading. SO2 breakthrough adsorption capacity of SBA‐15‐TEA‐50 was 146.3 mg of SO2/(g of adsorbent). The integrated two‐stage removal experiment of SO2 and CO2 over SBA‐15‐TEA and SBA‐15‐TEPA showed that CO2 and SO2 in gas mixture can be removed in two stages, respectively. Regeneration experiment showed that both the SO2 and CO2 breakthrough capacity almost kept a constant in the multiple cycles, and the regeneration of integrated two‐stage system was stable. © 2017 Curtin University of Technology and John Wiley & Sons, Ltd.
Spectral investigations on Eu3+,Sm3+‐doped and Sm3+/Eu3+ co‐doped potassium‐fluoro‐phosphate glass emitting intense orange‐red for lighting applications
Authors: Anil Kumar Kapuluri , Babu Singarapu , Reddy Prasad Vasanthapalli , Damodaraiah Samadam , Ratnakaram Yadala Chenchu
Published: June 2017

Potassium fluoro‐phosphate (KFP) glass singly doped with different concentrations of europium (Eu3+) or samarium (Sm3+) or co‐doped (Sm3+/Eu3+) was prepared, and their luminescence spectra were investigated. The phase composition of the product was verified by X‐ray diffraction analysis. Optical transition properties of Eu3+ in the studied potassium phosphate glass were evaluated in the framework of the Judd–Ofelt theory. The radiative transition rates (AR), fluorescence branching ratios (β), stimulated emission cross‐sections (σe) and lifetimes (τexp) for certain transitions or levels were evaluated. Red emission of Eu3+ was exhibited mainly by the 5D0→7F2 transition located at 612 nm. Concentration quenching and energy transfer were observed from fluorescence spectra and decay curves, respectively. It was found that the lifetimes of the 5D0 level increased with increase in concentration and then decreased. By co‐doping with Sm3+, energy transfer from Sm3+ to Eu3+ occurred and contributed to the enhancement in emission intensity. Intense orange‐red light emission was obtained upon sensitizing with Sm3+ in KFP glass. This approach shows significant promise for use in reddish‐orange lighting applications. The optimized properties of the Sm3+/Eu3+ co‐doped potassium phosphate glass might be promising for optical materials.
Anticancer effects of oleuropein
Authors: Shamshoum Hesham , Vlavcheski Filip , Tsiani Evangelia
Published: June 2017

Cancer cells exhibit enhanced proliferation rate and a resistance to apoptosis. Epidemiological studies suggest that olive oil intake is associated with a reduced risk of cancer. Olive oil, olives, and olive leaves contain many polyphenols, including oleuropein. Recently, several studies have demonstrated that oleuropein inhibits proliferation and induces apoptosis in different cancer cell lines. In addition, anticancer effects of oleuropein have been seen in animal studies. These effects are associated with oleuropein's ability to modulate gene expression and activity of a variety of different signaling proteins that play a role in proliferation and apoptosis. This article summarizes the existing in vitro and in vivo studies focusing on the anticancer effects of oleuropein and its effects on key signaling molecules. © 2017 BioFactors, 43(4):517–528, 2017
Zeitmessung in biologischen Systemen
Authors: Prinzinger Roland
Published: June 2017

Leben zeigt klare Abschnitte (zum Beispiel Embryo‐ und Ontogenese, Altern), deren Dauer man durch Allometrien beschreiben und zeitlich in chronologischen und/oder physiologischen Einheiten angeben kann. Erstere sind physikalisch auf der Basis der Abfolge von periodischen Ereignissen definiert. Sie können aber viele biologische Zeiten nicht befriedigend beschreiben. Biologische Uhren beruhen auf zahlreichen anderen Zeitmessern, die im Organismus selbst liegen und den gleichen Zeittakt zeigen und die nicht primär (nur) auf periodischen Abfolgen beruhen.
Ein Krebs für die Krebsforschung
Authors: Lyko Frank
Published: June 2017

Der Marmorkrebs ist ein seit Mitte der 1990er Jahre bekannter triploider Flusskrebs, der sich parthenogenetisch fortpflanzt. Er stammt von der in Nord‐Amerika vorkommenden Decapoden‐Art Procambarus fallax ab und wurde als populäres Aquariumstier verbreitet. Aufgrund von Freisetzungen gibt es inzwischen eine Vielzahl von stabilen Freiland‐Populationen mit ernstzunehmendem invasiven Potenzial. Interessanterweise pflanzt sich der Marmorkrebs über einen parthenogenetischen Mechanismus fort, der zur Bildung einer klonalen Population mit minimaler genetischer Variabilität führt. Auch lassen sich die Tiere problemlos unter Laborbedingungen züchten und manipulieren. Diese Eigenschaften etablieren den Marmorkrebs als neuartigen und innovativen Modellorganismus für die Tumorbiologie, insbesondere für die Erforschung der klonalen Evolution und epigenetischen Anpassung von Tumorgenomen.
Vogelstimmen
Authors: Bergmann Hans‐Heiner
Published: June 2017

Vogelstimmen sind Teil der Biodiversität. Sie spielen eine Rolle bei der Artbildung. In vielen Fällen werden sie von Generation zu Generation tradiert und können Dialekte bilden. Man kann sie schwarz auf weiß aufzeichnen. Mit ihnen umzugehen, fällt vielen Menschen schwer. Für das Kennenlernen sind zahlreiche verschiedene Hilfsmittel verfügbar. Vogelstimmen zu erkunden kann zum Vergnügen werden und zugleich zu einem kognitiven Erlebnis, das von einer wachsenden Zahl von Menschen gesucht wird.
Wo lebten die ersten Zellen – und wovon?
Authors: Martin William F. , Zimorski Verena , Weiss Madeline C.
Published: June 2017

Der letzte universelle gemeinsame Vorfahre allen Lebens (Luca) wurde lange als der gemeinsame Vorfahre von Bakterien, Archaeen und Eukaryoten betrachtet. Neue Stammbäume des Lebens zeigen jedoch den Ursprung der Eukaryoten innerhalb der Archaeen, somit wird Luca zum gemeinsamen Vorfahren der Bakterien und Archaeen. Informationen über Lucas Lebensraum und Lebensweise (Physiologie) gab es bisher nicht. Eine neue Arbeit konnte die mikrobielle Ökologie Lucas nun rekonstruieren. Nach phylogenetischen Kriterien gehen 355 Gene (Proteinfamilien) auf Luca zurück. Danach war Luca anaerob, CO2‐ und N2‐fixierend, H2‐abhängig und thermophil. Lucas Proteine waren reichlich mit FeS‐Zentren und radikalen Reaktionsmechanismen ausgestattet und erforderten Kofaktoren, bei denen Übergangsmetalle eine tragende Rolle spielen. Luca bewohnte eine geochemisch aktive Umgebung, die reich an H2, CO2 und Eisen war. Diese mikrobielle Ökologie ähnelt der heutiger acetogener Bakterien und methanogener Archaeen, den physiologisch ursprünglichsten Mikroben.
Phytochrom als Thermometer: The heat is on
Authors: Staiger Dorothee
Published: June 2017

Die Umgebungstemperatur beeinflusst das Wachstum der Pflanzen. Erhöhte Temperaturen fördern das Längenwachstum der Stängel und Blattstiele. Auf molekularer Ebene ist bekannt, dass der Transkriptionsfaktor PHYTOCHROME INTERACTING FACTOR 4 (PIF4) bei höheren Temperaturen Gene für das Längenwachstum anschaltet. Nun rückt der Lichtrezeptor Phytochrom selbst ins Blickfeld: Phytochrom wirkt auch als Thermometer und justiert die Aktivität von PIF4 auf die Umgebungstemperatur ein.
Modulares Klonieren: Puzzeln für Fortgeschrittene
Authors: Meier Doreen , Friedrich Michael
Published: June 2017

Das Klonieren steht meist am Beginn gentechnischer Experimente und hat schon so manchen Forscher zur Weißglut getrieben. Dabei geht es eigentlich nur darum, DNA‐Stücke mit passenden Enden zusammenzufügen: molekulares Puzzeln! Restriktionsenzyme schneiden DNA und erzeugen Puzzleteile mit charakteristischen einzelsträngigen Enden. Ligasen können Puzzleteile mit passenden Enden verbinden. Im Rahmen des modularen Klonierens (MoClo: von modular cloning) wird Altbewährtes neu gedacht. In wenigen aufeinanderfolgenden Reaktionen können sogar Schaltkreise aus mehreren Genen aufgebaut werden.
Putzwahn und Atemtechnik
Authors: Hauk Andrea
Published: June 2017

Nachwuchs! Und wie geht es jetzt weiter? Es wird viel diskutiert über die Vereinbarkeit von Familie und Beruf. Andrea Hauk – BIUZ‐Lesern bekannt als Autorin der Laborseite – berichtet im dritten Teil unserer Reihe von ihren Erfahrungen.
Die Königin unter den Gewürzen: Vanille
Authors: Rösemann Ulrich
Published: June 2017

Zur großen Familie der Orchideengewächse gehört als einzige Nutzpflanze auch die Vanille. Ihr natürliches Verbreitungsgebiet liegt in Mexiko. Die Frucht der Orchideen wurde schon früh zum Würzen des Kakaos genutzt. Lange bevor die Spanier nach Zentralamerika kamen, haben die Azteken Vanille ihrem berühmten Chocolatl als „Gewürz“ beigefügt. Vanille fand auch als Aphrodisiakum und Antiseptikum Verwendung. Bis 1846 durften nur die Früchte Mexiko verlassen, denn Mexiko hatte das Exportmonopol für Vanille.
Bivalirudin or heparin for radial access?
Authors: Bittl John A.
Published: June 2017

Key Points

Bivalirudin is a reasonable choice during transradial PCI for acute MI when bleeding risk is high and clopidogrel or cangrelor is used

Heparin is reasonable during transradial PCI when bleeding risk is low and high-intensity antiplatelet therapy is used

Future studies are required to define the utility of post-PCI bivalirudin infusions
Melody valve within a dysfunctional freestyle bioprosthesis: Yes, you can fit a round peg in a calcified hole
Authors: Parekh Dhaval R. , Krajcer Zvonimir
Published: June 2017

Key Points

Transcatheter pulmonary valve implantation (TPVI) within a failed bioprosthetic valve is safe and effective

Coronary artery compression is a potential risk, requiring careful preimplantation balloon dilation testing

Prestenting is required for TPVI in stentless conduits

Improvements in right ventricular volume, pressure, pulmonary stenosis, and regurgitation can be maintained in the intermediate term

Long‐term risk for Melody valve endocarditis and valve dysfunction necessitates careful monitoring
Selective Levulinic Acid Hydrogenation in the Presence of Hybrid Dendrimer‐Based Catalysts. Part I: Monometallic
Authors: Maximov Anton L. , Zolotukhina Anna V. , Mamedli Adila A. , Kulikov Leonid A. , Karakhanov Edward A.
Published: June 2017

Hybrid Ru‐containing catalysts, based on poly(propylene imine) (PPI) dendrimers, immobilized in silica pores, were synthesized and characterized by transmission electron microscopy and X‐ray photoelectron spectroscopy. The synthesized Ru catalysts proved their efficiency in the selective hydrogenation of levulinic acid and its esters at 80 °C, 30 bar of H2, and 50 % volume substrate concentration in water. Quantitative yields of γ‐valerolactone were obtained for both micro‐ and mesoporous Ru catalysts within 2 h with catalytic activity as high as 1610 h−1. The reaction rate and selectivity on γ‐valerolactone were found to depend on several factors such as carrier structure, temperature, presence of water, and substrate/Ru ratio. The novelty of these hybrid materials is the presence of both weak acid (SiO2) and organic base centers (dendrimer amino groups), enhancing the dispersion of Ru nanoparticles. The presence of amino groups in the catalyst stabilizes the Ru nanoparticles during the synthesis and promotes the adsorption of levulinic acid on the surface of Ru nanoparticles during the reaction. Synthesized hybrid Ru catalysts can be reused several times without significant loss of activity.
Hierarchical Mn3O4 Microplates Composed of Stacking Porous Nanosheets for High‐Performance Lithium Storage
Authors: Ma Fei‐Xiang , Wu Hao Bin , Sun Xue‐Yin , Wang Pan‐Pan , Zhen Liang , Xu Cheng‐Yan
Published: June 2017

Transition metal oxide based anodes with high capacities and long cycle lifetimes are considered promising candidates to substitute the conventional graphite electrodes with a relatively low capacity. In this work, hierarchical Mn3O4 microplates with a lateral size of approximately 4.9 μm, composed of stacking porous nanosheets with thicknesses as small as 10 nm, were synthesized by using a precursor conversion method. Such a nanosheet stacking arrangement possesses an unusual concave structure with a tight center and loose edge. Owing to the highly open hierarchical structure and good electronic conductivity from the in situ carbon, the as‐obtained hierarchical Mn3O4 microplate electrode exhibits remarkable cyclability up to 300 cycles at 500 mA g−1, accompanied with good rate capability (418 mA h g−1 at 2 A g−1).
Aggregation‐Induced Emission (AIE) Fluorophore Exhibits a Highly Ratiometric Fluorescent Response to Zn2+ in vitro and in Human Liver Cancer Cells
Authors: Mehdi Hassan , Gong Weitao , Guo Huimin , Watkinson Michael , Ma Hua , Wajahat Ali , Ning Guiling
Published: June 2017

Two novel organic fluorophores, containing bis‐naphthylamide and quinoline motifs, have been designed and synthesized. One of the fluorophores contains an isobutylene unit and exhibits a significant aggregation‐induced emission (AIE) and a remarkable highly selective ratiometric fluorescence response towards Zn2+ in solution as well as in human liver cancer cells. The AIE behavior of this fluorophore was fully verified by fluorescence and UV/Vis spectroscopy, quantum yield calculations, and single‐crystal X‐ray diffraction, which revealed an intricate crystal packing system. Conversely, a fluorophore that lacks the isobutylene moiety did not exhibit any significant fluorescent properties as a result of its more flexible molecular structure that presumably allows free intramolecular rotational processes to occur.
An association between volumes of the cardiac chambers and troponin levels in individuals submitted to cardiac coronary computed tomography
Authors: Rozenbaum Zach , Arbel Yaron , Granot Yoav , Cohen Dotan , Shmilovich Haim , Ziv‐Baran Tomer , Chorin Ehud , Havakuk Ofer , Cohen Merav , Berliner Shlomo , Topilsky Yan , Aviram Galit
Published: June 2017

Background

Previous echocardiographic studies have revealed an association between enlarged cardiac chamber volumes and elevated troponin concentrations. An automatic 4‐chamber volumetric analysis tool was adopted to investigate this association in patients who underwent cardiac‐gated computed tomography angiography (CCTA).

Hypothesis

We hypothesized that troponin concentration within the normal range correlates with cardiac chambers' volumes.

Methods

Serum troponin was obtained from 157 ambulatory patients before undergoing CCTA for nonacute coronary artery evaluation. Volumes of the cardiac chambers and the left ventricular mass were automatically analyzed and indexed to body surface area. Patients with a troponin concentrations within the upper quartile (>0.007 ng/mL, n = 39) were compared to patients with a troponin concentrations within the 3 lower quartiles of troponin concentrations (≤0.007 ng/mL, n = 118).

Results

None of the patients had a troponin concentration >0.05 ng/mL (the 99th percentile of the general population). There were no significant differences in baseline characteristics between the groups. There were significant correlations between troponin and ventricular volumes after adjustments for age and gender. In an analysis that included 107 patients without any known heart diseases, including those pathological findings in the current CCTA, there were significant correlations between troponin and the left and right ventricular volumes after adjustments for age, gender, and baseline characteristics (odds ratio [OR]: 1.08, 95% confidence interval [CI]: 1.03‐1.14, P = 0.002 and OR: 1.11, 95% CI: 1.04‐1.19, P = 0.002; respectively).

Conclusions

Using the technology of automatic volumetric analysis in individuals undergoing CCTA, an association between larger right and left cardiac chambers and higher levels of troponin concentration was shown.
First‐Principles Simulation of Raman Spectra of Adsorbates on Metal Surfaces
Authors: Ding Zhao‐Bin , Tommasini Matteo , Maestri Matteo
Published: June 2017

A general method is proposed to simulate the Raman spectra of adsorbates on metal surfaces. This method is based on an electrostatic‐corrected cluster model with additional charges to compensate the loss of coordination of metal atoms, and an external field added to simulate the surface dipole and to reproduce the charge distribution obtained from periodic calculations. As a result, it is possible to couple the phonon calculation with the Raman tensors computed by this corrected cluster model to simulate the Raman spectra of the adsorbates on metal surfaces. In doing so, it is possible to overcome both the infinite dielectric constant of the ideal metal, which makes calculating Raman spectra with current periodic models impossible, and the inaccuracy in adsorbate–metal interactions described by the cluster model. By means of this method, the relative experimental Raman intensity peaks of ethylene adsorbed on metal surfaces were successfully reproduced. Moreover, the model analysis allowed relating the enhancement of the Raman intensity of both CO and ethylene upon chemisorption on the metal surface to both the gain of charges on C atoms and the polarization of orbitals. As such, the proposed method provides an accurate and efficient way to simulate and interpret Raman spectra of adsorbates on metal surfaces.
Corporate Social Responsibility and Shareholder Proposals
Authors: Eding Erwin , Scholtens Bert
Published: June 2017

We study how corporate social responsibility relates to investors, firms, and shareholder proposals. We examine shareholder proposals on environmental, social, and governance issues at the annual general meeting of shareholders with US Fortune 250 firms during 2011–2014. We find that the probability of receiving shareholder proposals on environmental issues is positively associated with responsible institutional ownership. We find no systematic evidence that the outperformance regarding social responsibility of the firms themselves would significantly matter regarding the likelihood of shareholders filing proposals about corporate social responsibility, except for employee wellbeing. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment
Oxygen Vacancy Engineering of Co3O4 Nanocrystals through Coupling with Metal Support for Water Oxidation
Authors: Zhang Jun‐Jun , Wang Hong‐Hui , Zhao Tian‐Jian , Zhang Ke‐Xin , Wei Xiao , Jiang Zhi‐Dong , Hirano Shin‐Ichi , Li Xin‐Hao , Chen Jie‐Sheng
Published: June 2017

Oxygen vacancies can help to capture oxygen‐containing species and act as active centers for oxygen evolution reaction (OER). Unfortunately, effective methods for generating a high amount of oxygen vacancies on the surface of various nanocatalysts are rather limited. Here, we described an effective way to generate oxygen‐vacancy‐rich surface of transition metal oxides, exemplified with Co3O4, simply by constructing highly coupled interface of ultrafine Co3O4 nanocrystals and metallic Ti. Impressively, the amounts of oxygen vacancy on the surface of Co3O4/Ti surpassed the reported values of the Co3O4 modified even under highly critical conditions. The Co3O4/Ti electrode could provide a current density of 23 mA cm−2 at an OER overpotential of 570 mV, low Tafel slope, and excellent durability in neutral medium. Because of the formation of a large amount of oxygen vacancies as the active centers for OER on the surface, the TOF value of the Co3O4@Ti electrode was optimized to be 3238 h−1 at an OER overpotential of 570 mV, which is 380 times that of the state‐of‐the‐art non‐noble nanocatalysts in the literature.
Tree growth traits and social status affect the wood density of pioneer species in secondary subtropical forest
Authors: Chen Lingxiu , Xiang Wenhua , Wu Huili , Lei Pifeng , Zhang Shengli , Ouyang Shuai , Deng Xiangwen , Fang Xi
Published: June 2017

Wood density (WD) is not only an important parameter to estimate aboveground biomass but also an indicator of timber quality and plant adaptation strategies to stressful conditions (i.e., windthrow, pests, and pathogens). This study had three objectives: (1) to compare WD among seven subtropical tree species; (2) to determine how tree growth traits may influence possible differences in WD between the pioneer and shade‐tolerant species; and (3) to examine whether or not WD differs by tree social status (dominant vs. suppressed trees) within species. To do this, 70 trees were destructively harvested. From each tree, disks at different stem heights were obtained and subjected to a method of stem analysis to measure whole tree level WD. The results showed that WD differed significantly among the seven species (p < .001). Their average WD was 0.537 g/cm3, ranging from 0.409 g/cm3 for Choerospondias axillaris to 0.691 g/cm3 for Cyclobalanopsis glauca. The average WD of the four pioneer species (0.497 ± 0.13 g/cm3) was significantly lower (p < .01) than that of the three shade‐tolerant species (0.589 ± 0.12 g/cm3). The WD of the pioneers had a significant positive correlation with their stem diameter at breast height (DBH), tree height (H), and tree age, but WD had a significant negative correlation with relative growth rate (RGR). In contrast, the WD of the shade‐tolerant tree species had no significant relationships with DBH, H, tree age, or RGR. The dominant trees of the pioneer species had a higher WD than the suppressed trees, whereas the shade‐tolerant species had a lower WD for dominant trees than the suppressed trees. However, the differences in WD between dominant and suppressed trees were not significant. Taken together, the results suggest that classifying species into pioneer and shade‐tolerant groups to examine the effects of tree growth traits and social status could improve our understanding of intra‐ and interspecific variation in WD among subtropical tree species.
Local Climate Governance in the Global South: The case of eThekwini Municipality and the Responsible Accommodation Campaign
Authors: Lervik Marita , Sutherland Catherine
Published: June 2017

Local climate governance has become a key focus of the climate change agenda. Much research has been conducted on the topic in northern countries, but more research is needed in the South, where local governments often are less equipped to deal with challenges associated with climate change. This paper discusses different forms of local climate governance, with a specific focus on the relevance of networks. Local climate governance in eThekwini Municipality, South Africa, is used as a case study, particularly focusing on a campaign that was implemented in 2011 before the international climate conference (COP17). The modes of governing in eThekwini are considered through a framework of local climate governing and identified mainly as self‐governing and governing through enabling, the campaign being an example of the latter. The campaign also exemplifies how network governance can shape climate policy and significantly alter a project from initiation to implementation. While networks can contribute to improved communication and information exchange, there may be an inherent risk of private partners having a perverse incentive against implementing effective climate policies due to their own interests in maintaining current structures. It is not clear whether the change from regulative governance to governing by enabling will lead to more effective climate policies in the longer term. More research is required to determine this. While this study is too small to make broader generalizations, it does provide insight into how the introduction of network governance may impact climate governance at the local level in the South. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment
Building Practical Authority for Community Forestry in and through Networks: The role of community‐based organisations in the U.S. West
Authors: Abrams Jesse , Davis Emily Jane , Moseley Cassandra , Nowell Branda
Published: June 2017

Policy and economic changes in the late 20th century fundamentally reorganized the governance of public forestlands in the US West, throwing longstanding rural development trajectories into disarray. Place‐based NGOs emerged across the West in the wake of this transformation to help rural communities gain access to the benefits of new restoration‐oriented management paradigms. Here we analyse the practical efforts of two of these community‐based organizations, Wallowa Resources and the Watershed Research and Training Center, as they attempt to implement community forestry practices in highly complex institutional environments. We focus on the ways in which these organizations access and utilize social networks at multiple scales in order to build the ‘practical authority’ necessary to lead institutional change efforts in and on behalf of rural communities. We consider both the strategic advantages and the practical challenges of working in multiple forums at multiple scales in pursuit of linked community and environmental benefits. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment
Composition and functionality of the intrahepatic innate lymphoid cell‐compartment in human nonfibrotic and fibrotic livers
Authors: Forkel Marianne , Berglin Lena , Kekäläinen Eliisa , Carlsson Adrian , Svedin Emma , Michaëlsson Jakob , Nagasawa Maho , Erjefält Jonas S , Mori Michiko , Flodström‐Tullberg Malin , Bergquist Annika , Ljunggren Hans‐Gustaf , Westgren Magnus , Lindforss Ulrik , Friberg Danielle , Jorns Carl , Ellis Ewa , Björkström Niklas K , Mjösberg Jenny
Published: June 2017

Human innate lymphoid cells have been described to exist in different organs, with functional deregulation of these cells contributing to several disease states. Here, we performed the first detailed characterization of the phenotype, tissue‐residency properties, and functionality of ILC1s, ILC2s, and ILC3s in the human adult and fetal liver. In addition, we investigated changes in the ILC compartment in liver fibrosis. A unique composition of tissue‐resident ILCs was observed in nonfibrotic livers as compared with that in mucosal tissues, with NKp44− ILC3s accounting for the majority of total intrahepatic ILCs. The frequency of ILC2s, representing a small fraction of ILCs in nonfibrotic livers, increased in liver fibrosis and correlated directly with the severity of the disease. Notably, intrahepatic ILC2s secreted the profibrotic cytokine IL‐13 when exposed to IL‐33 and thymic stromal lymphopoetin (TSLP); these cytokines were produced by hepatocytes, hepatic stellate cells (HSCs), and Kupffer cells in response to TLR‐3 stimulation. In summary, the present results provide the first detailed characterization of intrahepatic ILCs in human adult and fetal liver. The results indicate a role for ILC2s in human liver fibrosis, implying that targeting ILC2s might be a novel therapeutic strategy for its treatment.
Surface uplift of the Central Yunnan Plateau since the Pliocene
Authors: Li Chaoyang , Jiang Xiaodian , Gong Wei , Li Deyong , Li Congying
Published: June 2017

The Central Yunnan Plateau (CYP) is located in the southeastern end of the Sichuan‐Yunnan rhombic block. CYP is surrounded by the South China Block to the east and the Indo‐China Block to the southwest. Stratigraphy and topography research shows the relative surface uplift of the CYP since the Pliocene. However, the widely accepted model of lower crustal flow is very difficult to fully explain the surface uplift of CYP, with faults and fold structures in the brittle shallow crust. The lower crust thickening led by the lower crustal flow only contributes 34–54% (600–950 m) of the total surface uplift. The wide‐angle seismic profiles and topography analysis show that the CYP surface uplift is predominately a consequence of isostatic compensation due to surface erosion, upper‐middle crustal shortening, and lower crustal thickening. The average isostatic adjustment caused by surface erosion of CYP is about 500 m, which is about 29% of the total surface uplift (1750 m). The GPS station velocities, focal mechanisms, and seismic anisotropy show the strong decoupling relationship between upper‐middle crust and lower crust. In detail, there is a movement with southeast‐directed and clockwise rotation around the Eastern Himalayan syntaxis in the upper‐middle crust, although south‐directed flow in the lower crust. The southeast motion of the upper‐middle crust could be resolved into two portions. The eastward component of upper‐middle crust motion is obstructed by the South China Block in the east. The result is the W‐E direction shortening of upper‐middle crust, shown by the S‐N trending CYP anticlinorium. The W‐E direction shortening of upper‐middle crust contributes 17–37% (300–650 m) of the total surface uplift. In contrast, the southward component of upper‐middle crust motion, shown by the sinistral strike‐slip displacement of the Xiaojiang fault zone, could pass through the Red River fault zone into the Indo‐China Block, where the left‐lateral Dien Bien Phu Fault would be the counterpart. The contribution of upper‐middle crustal shortening in a S‐N direction is very limited. The lower crustal flow could have been playing a prominent role in the growth of the whole southeast margin of the Tibetan Plateau, and the contribution from upper‐middle crustal shortening cannot be ignored in some local areas.
Geochemical and Sr‐Nd isotopic records of Paleoproterozoic metavolcanics and mafic intrusive rocks from the West African Craton: Evidence for petrogenesis and tectonic setting
Authors: Sakyi Patrick Asamoah , Anum Solomon , Su Ben‐Xun , Nude Prosper M. , Su Ben‐Can , Asiedu Daniel Kwadwo , Nyame Frank , Kwayisi Daniel
Published: June 2017

Metavolcanics and mafic intrusive rocks of the Paleoproterozoic Birimian terrane in the southeastern part of the West African Craton, Ghana, were analyzed for major and trace elements and Nd and Sr isotopic data to constrain the geodynamic evolution of the Birimian Supergroup. The metavolcanic rocks consist of metabasalts, meta‐andesites, and amphibolites, whereas the mafic intrusions are mainly gabbros, hornblendites, and dolerites. The rocks are tholeiitic in composition and show the classic features of arc magmatism. The metavolcanics display significant enrichments in large ion lithophile elements (LILE) and light rare earth elements, relative to high field strength elements (HFSE) and heavy rare earth elements. The multielement patterns of the rocks also show positive Pb, Ba, Th, and Sr and negative Nb, Ta, and Ce anomalies that are typical characteristics of subduction‐related magmas. They also have La/Nb ratios <3 and La/Ta ratios <43 that are similar to other Archean and Birimian greenstone belts in West Africa. The rocks have εNd (2.1 Ga) values of −0.96 to +2.60, and Nd model ages of 2.24–2.51 Ga (TDM1) and 2.16–2.45 Ga (TDM2), indicating their juvenile character with possible contributions from pre‐Birimian crustal materials in their sources. The εNd values suggest a depleted source and further indicate that they were probably produced in an almost entirely oceanic environment with minor influence from the continental crust. The Nd isotopic results are consistent with the island arc model, which views Paleoproterozoic terranes of the West African Craton in the context of subduction–accretion processes. Accordingly, these processes may have played a role in the formation of the Columbia supercontinent during the Paleoproterozoic (2.1–1.8 Ga) orogenic events.