bluuebunny/crossref_metadata_2025 huggingface dataset:
Simultaneous Measurements of Substorm‐Related Electron Energization in the Ionosphere and the Plasma Sheet
Authors: Sivadas N. , Semeter J. , Nishimura Y. , Kero A.
Published: September 2017

On 26 March 2008, simultaneous measurements of a large substorm were made using the Poker Flat Incoherent Scatter Radar, Time History of Events and Macroscale Interactions during Substorm (THEMIS) spacecraft, and all sky cameras. After the onset, electron precipitation reached energies ≳100 keV leading to intense D region ionization. Identifying the source of energetic precipitation has been a challenge because of lack of quantitative and magnetically conjugate measurements of loss cone electrons. In this study, we use the maximum entropy inversion technique to invert altitude profiles of ionization measured by the radar to estimate the loss cone energy spectra of primary electrons. By comparing them with magnetically conjugate measurements from THEMIS‐D spacecraft in the nightside plasma sheet, we constrain the source location and acceleration mechanism of precipitating electrons of different energy ranges. Our analysis suggests that the observed electrons ≳100 keV are a result of pitch angle scattering of electrons originating from or tailward of the inner plasma sheet at ~9RE, possibly through interaction with electromagnetic ion cyclotron waves. The electrons of energy 10–100 keV are produced by pitch angle scattering due to a potential drop of ≲10 kV in the auroral acceleration region (AAR) as well as wave–particle interactions in and tailward of the AAR. This work demonstrates the utility of magnetically conjugate ground‐ and space‐based measurements in constraining the source of energetic electron precipitation. Unlike in situ spacecraft measurements, ground‐based incoherent scatter radars combined with an appropriate inversion technique can be used to provide remote and continuous‐time estimates of loss cone electrons in the plasma sheet.
The Modulation of the Quasi‐Two‐Day Wave on Total Electron Content as Revealed by BeiDou GEO and Meteor Radar Observations Over Central China
Authors: Gu Sheng‐Yang , Lei Jiuhou , Dou Xiankang , Xue Xianghui , Huang Fuqing , Jia Mingjiao
Published: September 2017

The ground‐based total electron content (TEC) observations from BeiDou Geostationary Orbit (GEO) satellites provide more accurate temporal ionospheric variations nearly at the fixed ionospheric pierce points as compared with the non‐GEO TEC. BeiDou GEO TEC measurements during 2016, along with the horizontal wind observations from a collocated meteor radar, are utilized to quantitatively study the ionospheric response to the quasi‐two‐day wave (QTDW) in the neutral atmosphere at Meng Cheng (116.6°E, 33.3°N) over central China. The QTDW peaks during July with amplitudes of ~25–30 m/s for both zonal and meridional winds. It is suggested that the nonlinear interactions between the QTDW and tides and their influences on TEC are insignificant for this QTDW event. Nevertheless, the diurnal tide decreases by ~40–60% during the QTDW episode, which is most likely related to the change of background wind induced by the QTDW. Correspondingly, the 24 h oscillations in TEC decrease by ~18%. In addition, the wind perturbations of the QTDW can also possibly modulate the midlatitude electric dynamo and result in a quasi‐two‐day oscillation (QTDO) of ~1.2 total electron content unit (TECU), about ~10% of the background TEC. Our analysis also shows that the background TEC decreases by ~1 TECU (~8%) when the QTDW reaches maximum amplitude. This is probably related to the thermospheric composition changes (e.g., O and N2) induced by the QTDW dissipation.
Interesting Equatorial Plasma Bubbles Observed by All‐Sky Imagers in the Equatorial Region of China
Authors: Wu Kun , Xu Jiyao , Wang Wenbin , Sun Longchang , Liu Xiao , Yuan Wei
Published: September 2017

This paper reports some interesting equatorial plasma bubbles (EPBs) on 4 and 5 October 2013 and 29 and 30 September 2013 observed by two all‐sky imagers located in the magnetically equatorial region of Hainan (19.5°N; 9.5° geomagnetic latitude) and Guiping (23.8°N; 13.9° geomagnetic latitude), China. The case of 4 and 5 October 2013 shows the following: (1) EPBs had planar wave‐like structures and their wavefronts were parallel to each other before midnight. (2) The angle between the wavefronts of those EPBs and the geomagnetic meridian were ~30°. (3) Near midnight, the higher‐latitude part of one EPB suddenly began to rotate with a large eastward zonal drift, resulting in an unusual C‐shaped EPB that was observed for the first time by an all‐sky imager. (4) After midnight, one EPB merged into another EPB and formed an integrated EPB. The other EPB case on 29 and 30 September 2013 shows the following: (1) The images captured the full evolution processes of an “I” shaped EPB with an angle of ~30° with respect to the geomagnetic meridian. The imagers also observed “S” and “Y” shaped EPBs. (2) The change of EPBs' shape was directly related to the change of EPBs' zonal drift velocities. (3) The angle between the I‐shaped EPBs and the geomagnetic meridian was likely caused by the change of the latitudinal gradient of zonal neutral wind velocities and ionospheric conductivity. (4) The zonal velocity of each branch of the “Y” shape EPB was different, which could be related to the polarization electric fields within each branch.
Plankton Assemblage Estimated with BGC‐Argo Floats in the Southern Ocean: Implications for Seasonal Successions and Particle Export
Authors: Rembauville Mathieu , Briggs Nathan , Ardyna Mathieu , Uitz Julia , Catala Philippe , Penkerc'h Cristophe , Poteau Antoine , Claustre Hervé , Blain Stéphane
Published: September 2017

The Southern Ocean (SO) hosts plankton communities that impact the biogeochemical cycles of the global ocean. However, weather conditions in the SO restrict mainly in situ observations of plankton communities to spring and summer, preventing the description of biological successions at an annual scale. Here, we use shipboard observations collected in the Indian sector of the SO to develop a multivariate relationship between physical and bio‐optical data, and, the composition and carbon content of the plankton community. Then we apply this multivariate relationship to five biogeochemical Argo (BGC‐Argo) floats deployed within the same bio‐geographical zone as the ship‐board observations to describe spatial and seasonal changes in plankton assemblage. The floats reveal a high contribution of bacteria below the mixed layer, an overall low abundance of picoplankton and a seasonal succession from nano‐ to microplankton during the spring bloom. Both naturally iron‐fertilized waters downstream of the Crozet and Kerguelen Plateaus show elevated phytoplankton biomass in spring and summer but they differ by a nano‐ or microplankton dominance at Crozet and Kerguelen, respectively. The estimated plankton group successions appear consistent with independent estimations of particle diameter based on the optical signals. Furthermore, the comparison of the plankton community composition in the surface layer with the presence of large mesopelagic particles diagnosed by spikes of optical signals provides insight into the nature and temporal changes of ecological vectors that drive particle export. This study emphasizes the power of BGC‐Argo floats for investigating important biogeochemical processes at high temporal and spatial resolution.
Physicochemical and Biological Controls on Carbon and Nitrogen in Permafrost from an Ultraxerous Environment, McMurdo Dry Valleys of Antarctica
Authors: Faucher Benoit , Lacelle Denis , Davila Alfonso , Pollard Wayne , Fisher David , McKay Christopher P.
Published: September 2017

Little is known about the abundance and source of soil organic carbon and biogeochemical cycling in permafrost soils from the ultraxerous environment of the Dry Valleys of Antarctica. Here we investigate the distribution, source and cycling of organic carbon, total nitrogen and carbonates in the icy permafrost soils of University Valley, Quartermain Mountains. Results indicate that organic carbon content is lowest in icy soils from the perennially cryotic zone (<40 μg g−1 dry soils) and higher in the icy soils from the seasonally noncryotic zone, where the highest concentrations were found in the warmer‐wetter section of the valley and near a frozen pond (up to 313 μg g−1 dry soils). The δ13Corg of organic carbon in the icy soils showed that it is derived from the weathering of Beacon Supergroup sandstone that hosts active endolithic communities. The C:N ratios in icy soils formed two populations: one with ratios <5 and the other with ratios near the Redfield ratios. The low C:N ratios suggest that physicochemical processes dominates these soils, as supported by the absence of microbial activity and atmospherically deposited NO3 with minimal postdeposition modification. The near Redfield C:N ratios can be explained by physical processes (translocation of SOC in the soils from snow meltwater) or balanced microbial activity. The latter is supported by the δ13CCaCO3 values of carbonates that suggest a contribution from microbially respired endolith‐derived organic matter, providing indirect evidence of heterotrophic activity in permafrost soils from an ultraxerous environment.
Impact of Hydrogeological Uncertainty on Estimation of Environmental Risks Posed by Hydrocarbon Transportation Networks
Authors: Ciriello V. , Lauriola I. , Bonvicini S. , Cozzani V. , Di Federico V. , Tartakovsky Daniel M.
Published: September 2017

Ubiquitous hydrogeological uncertainty undermines the veracity of quantitative predictions of soil and groundwater contamination due to accidental hydrocarbon spills from onshore pipelines. Such predictions, therefore, must be accompanied by quantification of predictive uncertainty, especially when they are used for environmental risk assessment. We quantify the impact of parametric uncertainty on quantitative forecasting of temporal evolution of two key risk indices, volumes of unsaturated and saturated soil contaminated by a surface spill of light nonaqueous‐phase liquids. This is accomplished by treating the relevant uncertain parameters as random variables and deploying two alternative probabilistic models to estimate their effect on predictive uncertainty. A physics‐based model is solved with a stochastic collocation method and is supplemented by a global sensitivity analysis. A second model represents the quantities of interest as polynomials of random inputs and has a virtually negligible computational cost, which enables one to explore any number of risk‐related contamination scenarios. For a typical oil‐spill scenario, our method can be used to identify key flow and transport parameters affecting the risk indices, to elucidate texture‐dependent behavior of different soils, and to evaluate, with a degree of confidence specified by the decision‐maker, the extent of contamination and the correspondent remediation costs.
Forward treatment planning techniques to reduce the normalization effect in Gamma Knife radiosurgery
Authors: Cheng Hao‐Wen , Lo Wei‐Lun , Kuo Chun‐Yuan , Su Yu‐Kai , Tsai Jo‐Ting , Lin Jia‐Wei , Wang Yu‐Jen , Pan David Hung‐Chi
Published: September 2017

In Gamma Knife forward treatment planning, normalization effect may be observed when multiple shots are used for treating large lesions. This effect can reduce the proportion of coverage of high‐value isodose lines within targets. The aim of this study was to evaluate the performance of forward treatment planning techniques using the Leksell Gamma Knife for the normalization effect reduction. We adjusted the shot positions and weightings to optimize the dose distribution and reduce the overlap of high‐value isodose lines from each shot, thereby mitigating the normalization effect during treatment planning. The new collimation system, Leksell Gamma Knife Perfexion, which contains eight movable sectors, provides an additional means to reduce the normalization effect by using composite shots. We propose different techniques in forward treatment planning that can reduce the normalization effect. Reducing the normalization effect increases the coverage proportion of higher isodose lines within targets, making the high‐dose region within targets more uniform and increasing the mean dose to targets. Because of the increase in the mean dose to the target after reducing the normalization effect, we can set the prescribed marginal dose at a higher isodose level and reduce the maximum dose, thereby lowering the risk of complications.
Donepezil enhances understanding of degraded speech in Alzheimer's disease
Authors: Hardy Chris J. D. , Hwang Yun T. , Bond Rebecca L. , Marshall Charles R. , Ridha Basil H. , Crutch Sebastian J. , Rossor Martin N. , Warren Jason D.
Published: September 2017

Auditory dysfunction under complex, dynamic listening conditions is a clinical hallmark of Alzheimer's disease (AD) but challenging to measure and manage. Here, we assessed understanding of sinewave speech (a paradigm of degraded speech perception) and general cognitive abilities in 17 AD patients, before and following a 10 mg dose of donepezil. Relative to healthy older individuals, patients had impaired sinewave speech comprehension that was selectively ameliorated by donepezil. Our findings demonstrate impaired perception of degraded speech in AD but retained perceptual learning capacity that can be harnessed by acetylcholinesterase inhibition, with implications for designing communication interventions and acoustic environments in dementia.
Fused‐Ring Acceptors with Asymmetric Side Chains for High‐Performance Thick‐Film Organic Solar Cells
Authors: Feng Shiyu , Zhang Cai'e , Liu Yahui , Bi Zhaozhao , Zhang Zhe , Xu Xinjun , Ma Wei , Bo Zhishan
Published: September 2017

A kind of new fused‐ring electron acceptor, IDT‐OB, bearing asymmetric side chains, is synthesized for high‐efficiency thick‐film organic solar cells. The introduction of asymmetric side chains can increase the solubility of acceptor molecules, enable the acceptor molecules to pack closely in a dislocated way, and form favorable phase separation when blended with PBDB‐T. As expected, PBDB‐T:IDT‐OB‐based devices exhibit high and balanced hole and electron mobility and give a high power conversion efficiency (PCE) of 10.12%. More importantly, the IDT‐OB‐based devices are not very sensitive to the film thickness, a PCE of 9.17% can still be obtained even the thickness of active layer is up to 210 nm.
Solution Monolayer Epitaxy for Tunable Atomically Sharp Oxide Interfaces
Authors: Ron Alon , Hevroni Amir , Maniv Eran , Mograbi Michael , Jin Lei , Jia Chun‐Lin , Urban Knut W. , Markovich Gil , Dagan Yoram
Published: September 2017

Interfaces play an important role in a variety of devices including transistors, solar cells, and memory components. Atomically sharp interfaces are essential to avoid charge traps that hamper efficient device operation. Sharp interfaces usually require thin‐film fabrication techniques involving ultrahigh vacuum and high substrate temperatures. A new self‐limiting wet chemical process for deposition of epitaxial layers from alkoxide precursors is presented. This method is fast, cheap, and yields perfect interfaces as validated by various analysis techniques. It allows the growth of heterostructures with half‐unit‐cell resolution. The method is demonstrated by designing a hole‐type oxide interface SrTiO3/BaO/LaAlO3. It is shown that transport through this interface exhibits properties of mixed electron–hole contributions with hole mobility exceeding that of electrons.
Full‐Color Emission Polymer Carbon Dots with Quench‐Resistant Solid‐State Fluorescence
Authors: Shao Jieren , Zhu Shoujun , Liu Huiwen , Song Yubin , Tao Songyuan , Yang Bai
Published: September 2017

Polymer carbon dots (PCDs) represent a new class of carbon dots (CDs) possessing sub‐fluorophores and unique polymer‐like structures. However, like small molecule dyes and traditional CDs, PCDs often suffer from self‐quenching effect in solid state, limiting their potential applications. Moreover, it is hard to prepare PCDs that have the same chemical structure, exhibiting full‐color emission under one fixed excitation wavelength by only modulating the concentration of the PCDs. Herein, self‐quenching‐resistant solid‐state fluorescent polymer carbon dots (SSFPCDs) are prepared, which exhibit strong red SSF without any other additional solid matrices, while having a large production yield (≈89%) and a considerable quantum yield of 8.50%. When dispersed in water or solid matrices in gradient concentrations, they can exhibit yellow, green, and blue fluorescence, realizing the first SSFPCDs with the same chemical structure emitting in full‐color range by changing the ratio of SSFPCDs to the solid matrices.
Plasmonic Wood for High‐Efficiency Solar Steam Generation
Authors: Zhu Mingwei , Li Yiju , Chen Fengjuan , Zhu Xueyi , Dai Jiaqi , Li Yongfeng , Yang Zhi , Yan Xuejun , Song Jianwei , Wang Yanbin , Hitz Emily , Luo Wei , Lu Minhui , Yang Bao , Hu Liangbing
Published: September 2017

Plasmonic metal nanoparticles are a category of plasmonic materials that can efficiently convert light into heat under illumination, which can be applied in the field of solar steam generation. Here, this study designs a novel type of plasmonic material, which is made by uniformly decorating fine metal nanoparticles into the 3D mesoporous matrix of natural wood (plasmonic wood). The plasmonic wood exhibits high light absorption ability (≈99%) over a broad wavelength range from 200 to 2500 nm due to the plasmonic effect of metal nanoparticles and the waveguide effect of microchannels in the wood matrix. The 3D mesoporous wood with numerous low‐tortuosity microchannels and nanochannels can transport water up from the bottom of the device effectively due to the capillary effect. As a result, the 3D aligned porous architecture can achieve a high solar conversion efficiency of 85% under ten‐sun illumination (10 kW m−2). The plasmonic wood also exhibits superior stability for solar steam generation, without any degradation after being evaluated for 144 h. Its high conversion efficiency and excellent cycling stability demonstrate the potential of newly developed plasmonic wood to solar energy‐based water desalination.
Eutectic‐Derived Mesoporous Ni‐Fe‐O Nanowire Network Catalyzing Oxygen Evolution and Overall Water Splitting
Authors: Dong Chaoqun , Kou Tianyi , Gao Hui , Peng Zhangquan , Zhang Zhonghua
Published: September 2017

The development of efficient and abundant water oxidation catalysts is essential for the large‐scale storage of renewable energy in the form of hydrogen fuel via electrolytic water splitting, but still remains challenging. Based upon eutectic reaction and dealloying inheritance effect, herein, novel Ni‐Fe‐O‐based composite with a unique mesoporous nanowire network structure is designed and synthesized. The composite exhibits exceptionally low overpotential (10 mA cm−2 at an overpotential of 244 mV), low Tafel slope (39 mV dec−1), and superior long‐term stability (remains 10 mA cm−2 for over 60 h without degradation) toward oxygen evolution reaction (OER) in 1 m KOH. Moreover, an alkaline water electrolyzer is constructed with the Ni‐Fe‐O composite as catalyst for both anode and cathode. This electrolyzer displays superior electrolysis performance (affording 10 mA cm−2 at 1.64 V) and long‐term durability. The remarkable features of the catalyst lie in its unique mesoporous nanowire network architecture and the synergistic effect of the metal core and the active metal oxide, giving rise to the strikingly enhanced active surface area, accelerated electron/ion transport, and further promoted reaction kinetics of OER.
A Peroxisome‐Inspired Chemiluminescent Silica Nanodevice for the Intracellular Detection of Biomarkers and Its Application to Insulin‐Sensitizer Screening
Authors: Jie Xu , Yang Haimei , Wang Min , Zhang Yue , Wei Weili , Xia Zhining
Published: September 2017

The profiling of oxidase‐catalyzed biomarkers is an essential procedure for the diagnosis and precise treatment of metabolic diseases. Inspired by the metabolism of H2O2 in peroxisomes, a novel chemiluminescent silica nanodevice (CSN) was designed for the sensitive and selective sensing of intracellular oxidase‐catalyzed biomarkers. Oxidases catalyzed the oxidation of biomarkers followed by the production of H2O2, and then the generated H2O2 was employed to trigger chemiluminescence of the CSN. Utilizing this nanodevice, we not only accurately quantified intracellular glucose but also developed its further application for facile insulin sensitizer screening. Furthermore, sensitive and multiparametric analysis of oxidase‐catalyzed biomarkers like lactic acid, uric acid, and ethanol was demonstrated. Thus, this peroxisome‐inspired CSN holds great promise for the general diagnosis of metabolic diseases and in drug discovery.
Controlling Lanthanide Exchange in Triple‐Stranded Helicates: A Way to Optimize Molecular Light‐Upconversion
Authors: Zare Davood , Suffren Yan , Nozary Homayoun , Hauser Andreas , Piguet Claude
Published: September 2017

The kinetic lability of hexadentate gallium‐based tripods is sufficient to ensure thermodynamic self‐assembly of luminescent heterodimetallic [GaLn(L3)3]6+ helicates on the hour time scale, where Ln is a trivalent 4f‐block cation. The inertness is, however, large enough for preserving the triple‐helical structure when [GaLn(L3)3]6+ is exposed to lanthanide exchange. The connection of a second gallium‐based tripod further slows down the exchange processes to such an extent that spectroscopically active [CrErCr(L4)3]9+ can be diluted into closed‐shell [GaYGa(L4)3]9+ matrices without metal scrambling. This feature is exploited for pushing molecular‐based energy‐transfer upconversion (ETU) at room temperature.
Bulk Aggregation Based Fluorescence Turn‐On Sensors for Selective Detection of Progesterone in Aqueous Solution
Authors: Hong Seong Cheol , Murale Dhiraj P. , Lee Minju , Lee Seung Mi , Park Joong Shin , Lee Jun‐Seok
Published: September 2017

Steroids are polycyclic compounds that share tetracyclic ring as core scaffold, and selective detection of a steroid is challenging owing to their structural similarities. The discovery of chemosensors that recognize progesterone by alteration of self‐aggregation state is described, and these show significant fluorescence turn‐on. A self‐aggregated 48‐membered dansyl library was screened against a series of metabolites in aqueous buffer and discovered two compounds (PG‐1, PG‐2) exhibited exceptional selectivity for progesterone. Following studies of aggregation properties of probes using dynamic light scattering and transmission electron microscopy supports progesterone recognition lead to the generation of bulk aggregates that induce fluorescence enhancement. Though many fluorescence sensing mechanisms have been proposed, a sensing mode based on the bulk aggregate formation of fluorophore has never been reported, and this may open a new avenue of chemosensor design.
Flame retardant polyurethane foam prepared from compatible blends of soybean oil‐based polyol and phosphorus containing polyol
Authors: Zhang Kaibo , Hong Yongbo , Wang Niangui , Wang Yuhan
Published: September 2017

A phosphorus containing polyether polyol (THPO‐PO) was synthesized by polymerization between tris(hydroxymethyl) phosphine oxide (THPO) and propylene oxide (PO). A soybean oil‐based polyol(SBP) was synthesized from epoxidized soybean oil by ring‐opening reaction with lactic acid. The corresponding polyurethane foams (PUFs) were prepared by mixing SBP with THPO‐PO. The density of these foams decreased as the content of THPO‐PO increased. The yield strength of PUFs was observed to be decreased firstly and then increased with the addition of THPO‐PO. Microphotographs of PUFs were examined by scanning electron microscope which displayed the cells as spherical or polyhedral. The thermal degradation and fire behavior of PUFs were investigated by thermogravimetric analysis, limiting oxygen index (LOI), and UL‐94 test. Although the thermal stability of PUFs were decreased with increasing THPO‐PO percentage, the flame retardancy of PUFs were improved. The LOI value increased to 27.5 with 40% THPO‐PO. THPO‐PO in sequence worked in inhibiting flame and forming phosphorus‐rich char layer, thus endowing PUFs with the increased flame‐retardant performance. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45779.
Ontogeny of the Orbital Glands and Their Environs in the Pantropical Spotted Dolphin (Stenella attenuata: Delphinidae)
Authors: Rehorek Susan J. , Hillenius Willem J. , Lovano Denise M. , Thewissen J. G. M.
Published: September 2017

The nasolacrimal duct (NLD) connects the orbital (often associated with the Deep Anterior Orbital gland: DAOG, a.k.a. Harderian gland) and nasal regions in many tetrapods. Adult cetaceans are usually said to lack an NLD, and there is little agreement in the literature concerning the identity of their orbital glands, which may reflect conflicting definitions rather than taxonomic variation. In this study, we examined an embryological series of the pantropical spotted dolphin (Stenella attenuata), and report numerous divergences from other tetrapods. Underdeveloped eyelids and a few ventral orbital glands are present by late Stage (S) 17. By S 19, circumorbital conjunctival glands are present. In S 20, these conjunctival glands have proliferated, eyelids (and scattered palpebral glands) have formed, and a duct similar to the NLD has appeared. Subsequently, both the palpebral glands and the NLD are progressively reduced by S 22, even as the conjunctival glands exhibit regional growth. In most tetrapods examined, the ontogeny of the NLD follows a series of three stages: Inception of NLD, Connection of orbit and nasal cavity by the NLD and Ossification (i.e., formation of the bony canal surrounding the NLD, emerging into the orbit via the lacrimal foramen in the lacrimal bone). In contrast, the dolphin NLD originates at the same time as the lacrimal bone, and a lacrimal foramen fails to develop. The cetacean fossil record shows that a lacrimal foramen was present in the earliest ancestral amphibious, freshwater forms, but was soon lost as the lineage invaded the oceans. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 301:77–87, 2018. © 2017 Wiley Periodicals, Inc.
Studying the TRAF2 binding to model membranes: The role of subunits dissociation
Authors: Di Venere Almerinda , Nicolai Eleonora , Sinibaldi Federica , Di Pierro Donato , Caccuri Anna Maria , Mei Giampiero
Published: September 2017

The ability of a C‐terminal truncated form of TRAF2 to bind synthetic vesicles has been quantitatively studied by steady‐state fluorescence energy transfer from the protein to large unilamellar vesicles (LUVs) prepared with different lipid mixtures. The dissociation constants, the free energy of binding, and the average number of phospholipids interacting with truncated TRAF2 have been evaluated from the corresponding binding curves. The results indicate that the protein strongly interacts with the lipid bilayer, preferentially in the monomeric state. These findings have been discussed in terms of their possible role in the activity of TRAF2 in vivo.
Der Einfluß von grenzflächenaktivem Sorbat und Inkorporat auf Gitterdeformationen und Ruhepotentiale von Elektrolytkupfer
Authors: Eichkorn Günter , Schlitter Friedrich Wilhelm , Fischer Hellmuth
Published: September 2017

Der Einfluß von oberflächenaktivem Inhibitor (o‐Phenanthrolin) auf die Gefügebildung von elektrolytisch abgeschiedenem Kupfer wurde untersucht. Es wurde der Bedeckungsgrad als Funktion der Inhibitorkonzentration elektrochemisch bestimmt. Die Untersuchungen wurden mit spektralphotometrisch bestimmten Inkorporationsdichten im Metall ver‐glichen. Die Untersuchungen schlossen (BR)‐, (FT)‐ und (UD)‐Gefügetypen ein. Das Verhältnis der in‐korporierten zu adsorbierten Inhibitorkonzentrationen ist:

Mit Hilfe von Röntgenbeugungsuntersuchungen wurden die Gitterverzerrungen der verschiedenen Niederschläge bestimmt.

Untersuchungen der Ruhepotentiale zeigten, daß diese mit kleiner werdenden Teilchengrößen und an‐wachsenden Gitterverzerrungen negativer werden.

Es wurde festgestellt, daß die Aktivitäten der Metallphasen als proportional ihren Gitterverzerrungen der mehrdimensionalen Fehlordnung angenommen werden können.
Researching the interdisciplinary curriculum: The need for ‘translation devices’
Authors: Pountney Richard , McPhail Graham
Published: September 2017

This paper discusses the conceptual and methodological challenges facing two researchers investigating the development of interdisciplinary curricula in two new secondary schools, one in the UK and one in New Zealand. It is a discussion of research in progress that will be of interest to readers because of both the methodological challenges discussed and the research area itself. The key issue we identify is one for both researchers and teachers: how might the concepts and perspective of one discipline be brought into a relationship with another to enable deep learning? This question in turn highlights a key methodological challenge: developing the means to describe and evaluate new forms of curricular design and implementation where a traditional discipline‐based curriculum has been rejected in favour of interdisciplinary ones. The integrative aims of interdisciplinarity are also examined. We employ Bernstein's (2000) concept of knowledge structures and languages of description to theorise a continuum of approaches to curriculum integration, from functional to principled. This methodological manoeuvre is made possible by the development of a translation device. This procedural mechanism makes accessible to analysis the organising principles that are in play in the interdisciplinary curriculum design practices we have observed. We conclude with recommendations for the interdisciplinary curriculum researcher.
Activation of RARα, RARγ, or RXRα Increases Barrier Tightness in Human Induced Pluripotent Stem Cell‐Derived Brain Endothelial Cells
Authors: Stebbins Matthew J. , Lippmann Ethan S. , Faubion Madeline G. , Daneman Richard , Palecek Sean P. , Shusta Eric V.
Published: September 2017

The blood‐brain barrier (BBB) is critical to central nervous system (CNS) health. Brain microvascular endothelial cells (BMECs) are often used as in vitro BBB models for studying BBB dysfunction and therapeutic screening applications. Human pluripotent stem cells (hPSCs) can be differentiated to cells having key BMEC barrier and transporter properties, offering a renewable, scalable source of human BMECs. hPSC‐derived BMECs have previously been shown to respond to all‐trans retinoic acid (RA), and the goal of this study was to identify the stages at which differentiating human induced pluripotent stem cells (iPSCs) respond to activation of RA receptors (RARs) to impart BBB phenotypes. Here the authors identified that RA application to iPSC‐derived BMECs at days 6–8 of differentiation led to a substantial elevation in transendothelial electrical resistance and induction of VE‐cadherin expression. Specific RAR agonists identified RARα, RARγ, and RXRα as receptors capable of inducing barrier phenotypes. Moreover, RAR/RXRα costimulation elevated VE‐cadherin expression and improved barrier fidelity to levels that recapitulated the effects of RA. This study elucidates the roles of RA signaling in iPSC‐derived BMEC differentiation, and identifies directed agonist approaches that can improve BMEC fidelity for drug screening studies while also distinguishing potential nuclear receptor targets to explore in BBB dysfunction and therapy.
Polymerization of coniferyl alcohol by Mn3+‐mediated (enzymatic) oxidation: Effects of H2O2 concentration, aqueous organic solvents, and pH
Authors: Taboada‐Puig Roberto , Lú‐Chau Thelmo A. , Moreira María T. , Feijoo Gumersindo , Lema Juan M. , Fagerstedt Kurt , Ohra‐Aho Taina , Liitiä Tiina , Heikkinen Harri , Ropponen Jarmo , Tamminen Tarja
Published: September 2017

The objective of this study was to evaluate the ability of one versatile peroxidase and the biocatalytically generated complex Mn(III)‐malonate to polymerize coniferyl alcohol (CA) to obtain dehydrogenation polymers (DHPs) and to characterize how closely the structures of the formed DHPs resemble native lignin. Hydrogen peroxide was used as oxidant and Mn2+ as mediator. Based on the yields of the polymerized product, it was concluded that the enzymatic reaction should be performed in aqueous solution without organic solvents at 4.5 ≤ pH ≤ 6.0 and with 0.75 ≤ H2O2:CA ratio ≤ 1. The results obtained from the Mn3+‐malonate‐mediated polymerization showed that the yield was almost 100%. Reaction conditions had, however, effect on the structures of the formed DHPs, as detected by size exclusion chromatography and pyrolysis‐GC/MS. It can be concluded that from the structural point of view, the optimal pH for DHP formation using the presently studied system was 3 or 4.5. Low H2O2/CA ratio was beneficial to avoid oxidative side reactions. However, the high frequency of β–β linkages in all cases points to dimer formation between monomeric CA rather than endwise polymerization. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:81–90, 2018
Biogenic synthesis of copper oxide nanoparticles using olea europaea leaf extract and evaluation of their toxicity activities: An in vivo and in vitro study
Authors: Sulaiman Ghassan M. , Tawfeeq Amer T. , Jaaffer Marwa D.
Published: September 2017

Copper oxide nanoparticles (CUNPs) were synthesized using Olea europaea leaf extract as reducing and protecting agent. The formation of nanoparticles was observed through a color change from yellowish to brownish black. The CUNPs were confirmed with UV–Vis spectrophotometer, which revealed a peak absorbance at 289 nm. The synthesized CUNPs were characterized by XRD, FTIR, SEM, and TEM. The XRD pattern revealed that CUNPs were crystalline in nature with a diameter around 20 nm. FTIR spectral analysis showed that CUNPs were capped with plant constituents. From SEM and TEM analyses, the CUNPs were generally found to be spherical in shape, and the size range was 20–50 nm. Free radical scavenging potential of CUNPs against DPPH was confirmed by its stable antioxidant effects. In addition, the toxicity of CUNPs in mice was also assessed by body weight and weights of liver, kidneys, spleen, and thymus. The immune response in mice was signaled through an obvious change in spleen and thymus index, with a decrease of ADA enzyme activity in serum, spleen, and thymus after CUNPs treatment. The CUNPs were found to exert cell growth arrest against AMJ‐13 and SKOV‐3 cancer cells in a dose‐dependent manner and induce cell death by apoptosis. Less significant cytotoxic effect was observed in normal dermal fibroblast cells. These findings suggest that CUNPs may have the potential to be anticancer agents. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:218–230, 2018
Production of free fatty acids from switchgrass using recombinant Escherichia coli
Authors: Lee Jung‐Eun , Vadlani Praveen V. , Guragain Yadhu N. , San Ka‐Yiu , Min Doo‐Hong
Published: September 2017

Switchgrass is a promising feedstock to generate fermentable sugars required for the sustainable operation of biorefineries because of their abundant availability, easy cropping system, and high cellulosic content. The objective of this study was to investigate the potentiality of switchgrass as an alternative sugar supplier for free fatty acid (FFA) production using engineered Escherichia coli strains. Recombinant E. coli strains successfully produced FFAs using switchgrass hydrolysates. A total of about 3 g/L FFAs were attained from switchgrass hydrolysates by engineered E. coli strains. Furthermore, overall yield assessments of our bioconversion process showed that 88 and 46% of the theoretical maximal yields of glucose and xylose were attained from raw switchgrass during sugar generation. Additionally, 72% of the theoretical maximum yield of FFAs were achieved from switchgrass hydrolysates by recombinant E. coli during fermentation. These shake‐flask results were successfully scaled up to a laboratory scale bioreactor with a 4 L working volume. This study demonstrated an efficient bioconversion process of switchgrass‐based FFAs using an engineered microbial system for targeting fatty acid production that are secreted into the fermentation broth with associated lower downstream processing costs, which is pertinent to develop an integrated bioconversion process using lignocellulosic biomass. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:91–98, 2018
Biological Activities of Phenolics from the Fruits of Phyllanthus emblica L. (Euphorbiaceae)
Authors: Zhang Jie , Miao Dan , Zhu Wan‐Fang , Xu Jian , Liu Wen‐Yuan , Kitdamrongtham Worapong , Manosroi Jiradej , Abe Masahiko , Akihisa Toshihiro , Feng Feng
Published: September 2017

Seven phenolic compounds, 1 – 7, including a new organic acid gallate, mucic acid 1‐ethyl 6‐methyl ester 2‐O‐gallate (7), were isolated from the MeOH extract of the fruits of Phyllanthus emblica L. (Euphorbiaceae). The structures were elucidated on the basis of extensive spectroscopic analysis and comparison with literature data. Upon evaluated for their antioxidant abilities by 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH), 2,2′‐azinobis(3‐ethylbenzthiazoline‐6‐sulfonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays. The inhibitory activities against melanogenesis in B16 melanoma cells induced by α‐MSH, as well as cytotoxic activities against four human cancer cell lines were also evaluated. All phenolic compounds, 1 – 7, exhibited potent antioxidant abilities (DPPH: IC50 5.6 – 12.9 μm; ABTS: 0.87 – 8.43 μm Trolox/μm; FRAP: 1.01 – 5.79 μm Fe2+/μm, respectively). Besides, 5 – 7, also exhibited moderate inhibitory activities against melanogenesis (80.7 – 86.8% melanin content), even with no or low toxicity to the cells (93.5 – 101.6% cell viability) at a high concentration of 100 μm. Compounds 1 – 3 exhibited cytotoxic activity against one or more cell lines (IC50 13.9 – 68.4%), and compound 1 with high tumor selectivity for A549 (SI 3.2).
A High‐Throughput Mass‐Spectrometry‐Based Assay for Identifying the Biochemical Functions of Putative Glycosidases
Authors: Peng Tianyuan , Nagy Gabe , Trinidad Jonathan C. , Jackson Joy Marie , Pohl Nicola L. B.
Published: September 2017

The most commonly employed glycosidase assays rely on bulky ultraviolet or fluorescent tags at the anomeric position in potential carbohydrate substrates, thereby limiting the utility of these assays for broad substrate characterization. Here we report a qualitative mass spectrometry–based glycosidase assay amenable to high‐throughput screening for the identification of the biochemical functions of putative glycosidases. The assay utilizes a library of methyl glycosides and is demonstrated on a high‐throughput robotic liquid handling system for enzyme substrate screening. Identification of glycosidase biochemical function is achieved through the observation of an appropriate decrease in mass between a potential sugar substrate and its corresponding product by electrospray ionization mass spectrometry (ESI‐MS). In addition to screening known glycosidases, the assay was demonstrated to characterize the biochemical function and enzyme substrate competency of the recombinantly expressed product of a putative glycosidase gene from the thermophilic bacterium Thermus thermophilus.
Determination of Alkyl‐Donor Promiscuity of Tyrosine‐O‐Prenyltransferase SirD from Leptosphaeria maculans
Authors: Bandari Chandrasekhar , Scull Erin M. , Masterson Johanna M. , Tran Rachel H. Q. , Foster Steven B. , Nicholas Kenneth M. , Singh Shanteri
Published: September 2017

Natural product prenyltransferases are known to display relaxed acceptor substrate specificity. Although recent studies with a small set of unnatural alkyl donors have revealed that prenyltransferases are flexible with regard to their alkyl donors, the scope of their alkyl donor specificity remains poorly understood. Towards this goal, we report the synthesis of 20 unnatural alkyl pyrophosphate donors and an assessment of the reactions of these synthetic unnatural alkyl pyrophosphate analogues catalyzed by tyrosine O‐prenyltransferase SirD. This study demonstrates that SirD can utilize 16 out of 21 alkyl pyrophosphate analogues (including the natural donor) in catalyzing mostly O‐alkylation of l‐tyrosine. This study reveals the broad alkyl donor specificity of SirD and opens the door for the interrogation of the alkyl donor specificity of other prenyltransferases for potential utility as biocatalysts for differential alkylation applications.
A Promising High‐Voltage Cathode Material Based on Mesoporous Na3V2(PO4)3/C for Rechargeable Magnesium Batteries
Authors: Zeng Jing , Yang Yang , Lai Shaobo , Huang Jianxing , Zhang Yiyong , Wang Jing , Zhao Jinbao
Published: September 2017

The lack of suitable high‐voltage cathode materials has hindered the development of rechargeable magnesium batteries (RMBs). Here, mesoporous Na3V2(PO4)3/C (NVP/C) spheres have been synthesized through a facile spray‐drying–annealing method, and their electrochemically desodiated phase NaV2(PO4)3/C (ED‐NVP/C) has been investigated as an intercalation host for Mg2+ ions. The obtained ED‐NVP/C exhibits an average discharge voltage of around 2.5 V (vs. Mg2+/Mg), higher than those of most previously reported cathode materials. In addition, it can deliver an initial discharge capacity of 88.8 mA h g−1 at 20 mA g−1, with good cycling stability. Ex situ X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS) results demonstrate that the electrochemical reaction is based on an intercalation mechanism and shows good reversibility. Galvanostatic intermittent titration technique (GITT) data have revealed that the intercalation process involves a two‐phase transition. The reported ED‐NVP/C cathode material with high working voltage offers promising potential for application in RMBs.
New Architectures for Designed Catalysts: Selective Oxidation using AgAu Nanoparticles on Colloid‐Templated Silica
Authors: Shirman Tanya , Lattimer Judith , Luneau Mathilde , Shirman Elijah , Reece Christian , Aizenberg Michael , Madix Robert J. , Aizenberg Joanna , Friend Cynthia M.
Published: September 2017

A highly modular synthesis of designed catalysts with controlled bimetallic nanoparticle size and composition and a well‐defined structural hierarchy is demonstrated. Exemplary catalysts—bimetallic dilute Ag‐in‐Au nanoparticles partially embedded in a porous SiO2 matrix (SiO2–AgxAuy)—were synthesized by the decoration of polymeric colloids with the bimetallic nanoparticles followed by assembly into a colloidal crystal backfilled with the matrix precursor and subsequent removal of the polymeric template. This work reports that these new catalyst architectures are significantly better than nanoporous dilute AgAu alloy catalysts (nanoporous Ag3Au97) while retaining a clear predictive relationship between their surface reactivity with that of single‐crystal Au surfaces. This paves the way for broadening the range of new catalyst architectures required for translating the designed principles developed under controlled conditions to designed catalysts under operating conditions for highly selective coupling of alcohols to form esters. Excellent catalytic performance of the porous SiO2–AgxAuy structure for selective oxidation of both methanol and ethanol to produce esters with high conversion efficiency, selectivity, and stability was demonstrated, illustrating the ability to translate design principles developed for support‐free materials to the colloid‐templated structures. The synthetic methodology reported is customizable for the design of a wide range of robust catalytic systems inspired by design principles derived from model studies. Fine control over the composition, morphology, size, distribution, and availability of the supported nanoparticles was demonstrated.
Theoretical and Experimental Study of Structural Phases in CoMoO4†
Authors: Zagorac Dejan , Schön J. Christian , Rosić Milena , Zagorac Jelena , Jordanov Dragana , Luković Jelena , Matović Branko
Published: September 2017

New crystalline modifications of the technologically important compound CoMoO4 would be of great importance. Thus, the simple and fast Self‐Propagating Room Temperature procedure (SPRT) was used to synthesize crystalline phases of CoMoO4 at room temperature. X‐ray powder diffraction (XRPD) revealed that the synthesized material consists of two phases: CoMoO4(I) and CoMoO4(II), both with the monoclinic space group C2/m, No.12. This experimental exploration of the phase space of CoMoO4 was complemented by theoretical efforts. These consisted of a global search for structure candidates in the CoMoO4 system using fast empirical potentials. Eleven additional structure candidates have been found, several of which might be accessible to synthesis and/or shed light on other cobalt‐molybdenum oxides whose structure and composition are under discussion.
High‐volume steroid isotopic standards developed as working standards for gas chromatography–combustion–isotope ratio mass spectrometry
Authors: Tobias Herbert J. , Brenna J. Thomas
Published: September 2017

High‐precision carbon isotope ratio analysis of urinary steroids by gas chromatography–combustion–isotope ratio mass spectrometry (GC–C–IRMS) is the official test to detect illicit doping of synthetic versions of endogenous steroids, such as testosterone. Our group created the first steroid isotopic standards (SIS) specifically for World Anti‐Doping Agency (WADA) accredited laboratories. The standards contain mixtures of steroids as acetates or free steroids at ~400 μg each per ampoule and have been widely distributed to anti‐doping laboratories to facilitate comparability of inter‐laboratory results. Here we report on the creation and characterization of 3 new high‐volume single component SIS suitable for use as working standards. They contain ~50 times more steroid mass per ampoule than previous SIS. The new SIS, coded CU/PCC 40‐1, CU/PCC 41‐1, & CU/PCC 42‐1, contain ~20 mg of androsterone, androsterone‐AC, and 5α‐cholestane, with determined isotopic values of ‐27.09 ± 0.07 mUr, ‐32.82 ± 0.01 mUr, ‐25.03 ± 0.01 mUr, respectively. We used our previously developed protocol to calibrate the isotopically uniform steroids against the isotopic standard gases methane and ethane in NIST RM 8559 that are traceable to the international standard Vienna PeeDee Belemnite (VPDB). Two sets of data, acquired 7 months apart, of absolute δ13CVPDB and ∆Δδ13CVPDB values from 8 randomly selected ampoules of all 3 SIS indicate uniformity of steroid isotopic composition within measurement reproducibility, SD(δ13C) < 0.2 mUr Our results show that protocols for SIS extend to creation of high volume working standards that can also be used as internal standards under appropriate GC conditions.