bluuebunny/crossref_metadata_2025 huggingface dataset:
Response of Atlantic overturning to future warming in a coupled atmosphere‐ocean‐ice sheet model
Authors: Gierz Paul , Lohmann Gerrit , Wei Wei
Published: August 2015

Climate change can influence sea surface conditions and the melting rates of ice sheets; resulting in decreased deep water formation rates and ultimately affecting the strength of the Atlantic Meridional Overturning Circulation (AMOC). As such, a detailed study of the interactive role of dynamic ice sheets on the AMOC and therefore on global climate is required. We utilize a climate model in combination with a dynamic ice sheet model to investigate changes to the AMOC and North Atlantic climate in response to Intergovernmental Panel on Climate Change scenarios for RCP4.5 and RCP6. It is demonstrated that the inclusion of an ice sheet component results in a drastic freshening of the North Atlantic by up to 2 practical salinity units, enhancing high‐latitude haloclines and weakening the AMOC by up to 2 sverdrup (106 m3/s). Incorporating a bidirectionally coupled dynamic ice sheet results in relatively reduced warming over Europe due to the associated decrease in heat transport.
Topside ionospheric response to solar EUV variability
Authors: Anderson Phillip C. , Hawkins Jessica M.
Published: August 2015

We present an analysis of 23 years of thermal plasma measurements in the topside ionosphere from the Defense Meteorological Satellite Program (DMSP) spacecraft. The H+/O+ ratio and density vary dramatically with the solar cycle; cross‐correlation coefficients between E10.7 and the daily averaged densities are greater than 0.85. The ionospheric parameters also vary dramatically with season, particularly at latitudes away from the equator where the solar zenith angle varies greatly with season. There are also 27 day solar rotation periodicities in the density, associated with periodicities in the directly measured solar EUV flux. Empirical orthogonal function analysis captures over 95% of the variation in the density in the first two principal components. The first principal component (PC1) is clearly associated with the solar EUV while the second principal component (PC2) is clearly associated with the solar zenith angle variation. The magnitude of the variation of the response of the topside ionosphere to solar EUV variability is shown to be closely related to the ionospheric composition. This is interpreted as the result of the effect of composition on the scale height in the topside ionosphere and the “pivot effect” in which the variation in density near the F2 peak is amplified by a factor of e at an altitude a scale height above the F2 peak. When the topside ionosphere is H+ dominated during solar minimum, DMSP may be much less than a scale height above the F2 peak while during solar maximum, when it is O+ dominated, DMSP may be several scale heights above the F2 peak.
Two‐mode ionospheric response and Rayleigh wave group velocity distribution reckoned from GPS measurement following Mw 7.8 Nepal earthquake on 25 April 2015
Authors: Reddy C. D. , Seemala Gopi K.
Published: August 2015

The coseismic‐induced ionospheric total electron content (TEC) perturbations were analyzed following the Mw 7.8 Nepal earthquake (28.147°N, 84.708°E; depth ~15 km) that occurred on 25 April 2015 at 06:11:26 UTC. The ionospheric response is due to both the modes, i.e., shock acoustic waves (slow mode) and Rayleigh wave induced (fast mode). The continuous Global Positioning System (GPS) data at about 60 sites from various GPS networks have been used in the present study. All the sites within epicentral distance of ~2400 km and 70°–170° azimuth recorded the Rayleigh wave‐induced TEC response, while the sites within ~400–2200 km in the same azimuth recorded the response from both the modes. The maximum coseismic‐induced peak‐to‐peak TEC amplitude is ~1.2 total electron content unit, 1 TECU = 1016 el m−2. From Hodochron plot, the apparent Rayleigh wave velocity has been determined as ~2400 m/s on the average and the acoustic wave velocity as 1180 m/s, both these waves being discernible beyond ~1200 km of epicentral distance as also evident from Hodochron plot and wavelet spectrographs. We reckoned the Rayleigh wave group velocities using ionospheric response at selected radial pairs of stations and validated. The ionospheric response distribution seen mainly depending on the epicentral distance, satellite geometry, directivity of radiation pattern, and the upper crustal heterogeneity. This study highlights the characteristics of ionospheric response consequent to the 2015 Nepal earthquake.
Estimation of interplanetary electric field conditions for historical geomagnetic storms
Authors: Kumar Sandeep , Veenadhari B. , Tulasi Ram S. , Selvakumaran R. , Mukherjee Shyamoli , Singh Rajesh , Kadam B. D.
Published: August 2015

Ground magnetic measurements provide a unique database in understanding space weather. The continuous geomagnetic records from Colaba‐Alibag observatories in India contain historically longest and continuous observations from 1847 to present date. Some of the super intense geomagnetic storms that occurred prior to 1900 have been revisited and investigated in order to understand the probable interplanetary conditions associated with intense storms. Following Burton et al. (1975), an empirical relationship is derived for estimation of interplanetary electric field (IEFy) from the variations of Dst index and ΔH at Colaba‐Alibag observatories. The estimated IEFy values using Dst and ΔHABG variations agree well with the observed IEFy, calculated using Advanced Composition Explorer (ACE) satellite observations for intense geomagnetic storms in solar cycle 23. This study will provide the uniqueness of each event and provide important insights into possible interplanetary conditions for intense geomagnetic storms and probable frequency of their occurrence.
No clear evidence for localized tidal periodicities in earthquakes in the central Japan region
Authors: Wang W. , Shearer P. M.
Published: August 2015

We search for possible localized tidal triggering in earthquake occurrence near Japan by testing for tidal periodicities in seismicity within a variety of space/time bins. We examine 74,610 earthquakes of M ≥ 3 in the Japan Meteorological Agency catalog from January 2000 to April 2013. Because we use many earthquakes for which accurate focal mechanisms are not available, we do not compute tidal stresses on individual fault planes but instead assume that the mechanisms are likely to be similar enough among nearby events that tidal triggering will promote earthquake occurrence at specific tidal phases. After dividing the data into cells at a range of spatial (0.2°, 0.5°, and 1.0°) and temporal dimensions (100, 200, and 400 days), we apply Schuster's test for nonrandom event occurrence with respect to both the semidiurnal and semimonthly tidal phases. Because the resulting p values will be biased by temporal clustering caused by aftershocks, we apply a declustering method that retains only one event per tidal cycle per phase increment. Our results show a wide range of p values for the localized earthquake bins, but the number of bins with very small p values (e.g., p < 0.05) is no more than might be expected due to random chance, and there is no correlation of low p value bins with the time of the 2010 M 9.0 Tohoku‐Oki earthquake.
Characteristics and potential sources of atmospheric mercury at a subtropical near‐coastal site in East China
Authors: Yu Ben , Wang Xun , Lin Che‐Jen , Fu Xuewu , Zhang Hui , Shang Lihai , Feng Xinbin
Published: August 2015

To evaluate the impact of regional mercury (Hg) emissions and understand possible source regions of atmospheric Hg in Eastern China, 2 year observation for speciated atmospheric Hg was conducted at the Dameishan Atmospheric Observatory, a mountain site near the east coast of China. The observed concentration of total gaseous Hg (TGM) was 3.3 ± 1.4 ng m−3. During the sampling period, gaseous oxidized Hg and particulate bound Hg were 6.7 ± 4.3 pg m−3 and 180 ± 110 pg m−3 in winter and 5.9 ± 3.4 pg m−3 and 130 ± 100 pg m−3 in spring, respectively. The relatively high mean concentration of TGM was mainly caused by regional anthropogenic emissions and occasional long‐range transport from domestic source regions. Seasonal variation in the TGM concentration was observed with lower values in the wet monsoon season (from May to September) and higher values in the dry monsoon season (from October to April). Backward trajectories and potential source contribution function analysis suggested that anthropogenic Hg emission from coal combustion in the Yangtze River Delta region was the most likely cause for the elevated TGM concentrations. Relatively clean air originating from the East China Sea was the most possible cause for the observed low TGM concentrations. Positive correlation between TGM concentration and air quality index suggests that emissions that influenced regional air quality contributed to the elevated TGM concentrations.
Macroscopic cloud properties in the WRF NWP model: An assessment using sky camera and ceilometer data
Authors: Arbizu‐Barrena Clara , Pozo‐Vázquez David , Ruiz‐Arias José A. , Tovar‐Pescador Joaquín
Published: August 2015

The ability of six microphysical parameterizations included in the Weather Research and Forecasting (WRF) numerical weather prediction (NWP) model to represent various macroscopic cloud characteristics at multiple spatial and temporal resolutions is investigated. In particular, the model prediction skills of cloud occurrence, cloud base height, and cloud cover are assessed. When it is possible, the results are provided separately for low‐, middle‐, and high‐level clouds. The microphysical parameterizations assessed are WRF single‐moment six‐class, Thompson, Milbrandt‐Yau, Morrison, Stony Brook University, and National Severe Storms Laboratory double moment. The evaluated macroscopic cloud properties are determined based on the model cloud fractions. Two cloud fraction approaches, namely, a binary cloud fraction and a continuous cloud fraction, are investigated. Model cloud cover is determined by overlapping the vertically distributed cloud fractions following three different strategies. The evaluation is conducted based on observations gathered with a ceilometer and a sky camera located in Jaén (southern Spain). The results prove that the reliability of the WRF model mostly depends on the considered cloud parameter, cloud level, and spatiotemporal resolution. In our test bed, it is found that WRF model tends to (i) overpredict the occurrence of high‐level clouds irrespectively of the spatial resolution, (ii) underestimate the cloud base height, and (iii) overestimate the cloud cover. Overall, the best cloud estimates are found for finer spatial resolutions (1.3 and 4 km with slight differences between them) and coarser temporal resolutions. The roles of the parameterization choice of the microphysics scheme and the cloud overlapping strategy are, in general, less relevant.
Geometry and kinematics of the Grant Range brittle detachment system, eastern Nevada, U.S.A.: An end‐member style of upper crustal extension
Authors: Long Sean P. , Walker Jerome P.
Published: August 2015

Documenting the range of styles of normal faulting is fundamental to understanding crustal extension. Here geologic mapping, field relationships, and deformed and restored cross sections illustrate the geometry and kinematic development of a system of west‐vergent detachment faults in the Grant Range in eastern Nevada. Faults exhibit brecciation and stratigraphic cutoff angles of 5–15° at all structural levels and deform a 10 km thick section of Paleozoic and Paleogene rocks. The fault system is folded across an anticlinal culmination, which grew during extension, as indicated by progressively increasing interlimb angles and incision in the axial zone. The eastern limb consists of an imbricate stack of faults that were emplaced from bottom to top. In the western limb, several faults exhibit apparent thrust relationships. The oldest faults are cut by a ~29 Ma dike, and the highest preserved fault cuts ~32 Ma volcanic rocks that restore to paleodepths of ~1 km. Retrodeformation of folding and minimal structural relief and angularity across a Paleogene unconformity indicate the faults were active at 5–15° angles. Retrodeformation of offset indicates ≥49 km (98%) extension. We propose a model of stationary, sustained isostatic uplift and incision at the culmination axis (a “fixed hinge”), with updip excision producing bottom‐to‐top growth of the imbricate stack and downdip excision producing apparent thrust relationships. The fault system exhibits similarities to core complex detachment systems, though it is confined to upper crustal levels, and there are no preserved high‐angle or listric normal faults, indicating a unique extension style dominated by low‐angle excision.
High‐Strain‐Rate Superplasticity in Mg–Y–Nd Alloy Prepared by Submerged Friction Stir Processing
Authors: Cao Genghua , Zhang Datong , Chai Fang , Zhang Wen , Qiu Cheng
Published: August 2015

Superplastic tensile behavior of Mg–Y–Nd alloy prepared by submerged friction stir processing (SFSP) is investigated. Microstructure of the SFSP alloy is mainly composed of fine‐grained magnesium grains (≈1.3 µm) and homogeneously distributed second‐phase particles. Elongations are all above 500% within a wide high‐temperature range of 708–758 K at 1 × 10−1 s−1, and an elongation of 549% at 1 × 10−1 s−1 is achieved at 758 K. The excellent high‐strain‐rate superplasticity is attributed to the fine‐grained microstructure and high thermal stability during superplastic deformation. Grain boundary sliding is the dominated deformation mechanism during superplastic deformation, and the specimens failed through cavity coalescence.
Copper(I) Iodide as Hole‐Conductor in Planar Perovskite Solar Cells: Probing the Origin of J–V Hysteresis
Authors: Sepalage Gaveshana A. , Meyer Steffen , Pascoe Alexander , Scully Andrew D. , Huang Fuzhi , Bach Udo , Cheng Yi‐Bing , Spiccia Leone
Published: August 2015

Organic–inorganic lead halide perovskite solar cells are promising alternatives to silicon‐based cells due to their low material costs and high photovoltaic performance. In this work, thin continuous perovskite films are combined with copper(I) iodide (CuI) as inorganic hole‐conducting material to form a planar device architecture. A maximum conversion efficiency of 7.5% with an average efficiency of 5.8 ± 0.8% is achieved which, to our knowledge, is the highest reported efficiency for CuI‐based devices with a planar structure. In contrast to related planar 2,2′,7,7′‐tetrakis‐(N,N ‐di‐4‐methoxyphenylamino)‐9,9′‐spirobifluorene (spiro‐OMeTAD)‐based devices, the CuI‐based devices do not show a pronounced hysteresis when tested by scanning the potential in a forward and backward direction. The strong quenching of photoluminescence (PL) signal and comparatively fast decay of open‐circuit voltage demonstrates a more rapid removal of positive charge carriers from the perovskite layer when in contact with CuI compared to spiro‐OMeTAD. A slow response on a timescale of 10–100 s is observed for the spiro‐OMeTAD‐based devices. In comparison, the CuI‐based device displays a significantly faster response as determined through electrochemical impedance spectroscopy (EIS) and open‐circuit voltage decays (OCVDs). The characteristically slow kinetics measured through EIS and OCVD are linked directly to the current–voltage hysteresis.
Nanogap Engineered Plasmon‐Enhancement in Photocatalytic Solar Hydrogen Conversion
Authors: Chen Jie , Dong Chung‐Li , Du Yuanchang , Zhao Daming , Shen Shaohua
Published: August 2015

Graphitic carbon nitride modified with plasmonic Ag@SiO2 core–shell nanoparticles (g‐C3N4/Ag@SiO2) are proposed for enhanced photocatalytic solar hydrogen evolution under visible light. Nanosized gaps between the plasmonic Ag nanoparticles (NPs) and g‐C3N4 are created and precisely modulated to be 8, 12, 17, and 21 nm by coating SiO2 shells on the Ag NPs. The optimized photocatalytic hydrogen production activity for g‐C3N4/Ag@SiO2 is achieved with a nanogap of 12 nm (11.4 μmol h−1) to be more than twice as high as that of pure g‐C3N4 (5.6 μmol h−1). The plasmon resonance energy transfer (PRET) effect of Ag NPs is innovatively proved from a physical view on polymer semiconductors for photoredox catalysis. The PRET effect favors the charge carrier separation by inducing electron–hole pairs efficiently formed in the near‐surface region of g‐C3N4. Furthermore, via engineering the width of the nanogap, the PRET and energy‐loss Förster resonance energy transfer processes are perfectly balanced, resulting in considerable enhancement of photocatalytic hydrogen production activity over the g‐C3N4/Ag@SiO2 plasmonic photocatalyst.
Plasmon‐Assisted Indirect Light Absorption Engineering in Small Transition Metal Catalyst Nanoparticles
Authors: Antosiewicz Tomasz J. , Wadell Carl , Langhammer Christoph
Published: August 2015

Light absorption in plasmonic nanoantennas constitutes an interesting way of enhancing catalytic reactions occurring at surfaces of metals nanoparticles by forming hot electron–hole pairs. These can either directly transfer to empty orbitals of adsorbed species on the nanoparticle surface or thermalize via electron–phonon coupling and enhance reaction rates via a photothermal reaction channel. While this scheme, in principle, can be efficient for the well‐known plasmonic materials Ag and Au due to their large optical cross‐sections, other transition metals, which exhibit excellent catalytic properties, have spectrally broad and weak plasmon resonances. Thus, lower plasmon‐induced electron–hole pair excitation is expected, especially for sub‐10 nm nanoparticles, typical in heterogeneous catalysis. Here, a solution is presented to circumvent these limitations by challenging the established picture that plasmonic nanoparticles also constitute catalytically active entities in a plasmon mediated hot electron catalysis concept. Light absorption in catalyst nanoparticles can be engineered via an adjacent noble metal plasmonic nanoantenna that efficiently collects incident radiation with low losses, and couples it into the catalytic particles where the energy is dissipated due to the intrinsically high optical losses in transition metals at near‐visible frequencies. Absorption enhancement of 1–2 orders of magnitude is predicted in 3–4 nm sized Pd catalyst nanoparticles.
Enhancing the Thermoelectric Device Performance of Graphene Using Isotopes and Isotopic Heterojunctions
Authors: Anno Yuki , Takei Kuniharu , Akita Seiji , Arie Takayuki
Published: August 2015

The thermoelectric properties of various graphene samples, including isotopically modified heterostructures grown by chemical vapor deposition, are investigated from the viewpoint of thermoelectric device applications. The thermoelectric power of graphene varies from −80 to 90 μV K−1, depending on the applied gate voltage. Similar to typical metals and semiconductors, the thermoelectric power of graphene decreases as the electrical conductivity increases, regardless if isotopes are present. The results follow a line with a slope of −198 μV K−1 in the Jonker plot, indicating that the maximum power factor is 5.29 × 10−3 W m−1 K−2 irrespective of carbon isotope modulation in graphene. Because limiting phonon propagation independent of the electric properties can reduce the thermal conductivity of graphene containing carbon isotopes and isotopic heterojunctions, introducing carbon isotopes into the graphene structure improves the thermoelectric figure of merit without affecting the power factor.
A Novel High Capacity Positive Electrode Material with Tunnel‐Type Structure for Aqueous Sodium‐Ion Batteries
Authors: Wang Yuesheng , Mu Linqin , Liu Jue , Yang Zhenzhong , Yu Xiqian , Gu Lin , Hu Yong‐Sheng , Li Hong , Yang Xiao‐Qing , Chen Liquan , Huang Xuejie
Published: August 2015

Aqueous sodium‐ion batteries have shown desired properties of high safety characteristics and low‐cost for large‐scale energy storage applications such as smart grid, because of the abundant sodium resources as well as the inherently safer aqueous electrolytes. Among various Na insertion electrode materials, tunnel‐type Na0.44MnO2 has been widely investigated as a positive electrode for aqueous sodium‐ion batteries. However, the low achievable capacity hinders its practical applications. Here, a novel sodium rich tunnel‐type positive material with a nominal composition of Na0.66[Mn0.66Ti0.34]O2 is reported. The tunnel‐type structure of Na0.44MnO2 obtained for this compound is confirmed by X‐ray diffraction and atomic‐scale spherical aberration‐corrected scanning transmission electron microscopy/electron energy‐loss spectrum. When cycled as positive electrode in full cells using NaTi2(PO4)3/C as negative electrode in 1 m Na2SO4 aqueous electrolyte, this material shows the highest capacity of 76 mAh g−1 among the Na insertion oxides with an average operating voltage of 1.2 V at a current rate of 2 C. These results demonstrate that Na0.66[Mn0.66Ti0.34]O2 is a promising positive electrode material for rechargeable aqueous sodium‐ion batteries.
The separation of two different sized particles in an evaporating droplet
Authors: Devlin Nicole Raley , Loehr Katherine , Harris Michael T.
Published: August 2015

The separation of two different sized particles during evaporation of a dilute droplet is examined both computationally and experimentally. A transport model of the evaporating droplet system was solved using the finite element method to determine the fluid velocity, pressure, vapor concentration surrounding the droplet, temperature, and both particle concentrations. Experimentally, 1 μm and 3 μm polystyrene particles were used during the evaporation of a sessile water droplet. It was determined that to accurately model particle deposition, thermal effects need to be considered. The Marangoni currents in evaporating droplets keep particles suspended in the droplet until the end of the evaporation. Previous models of particle deposition during droplet evaporation have rapid accumulation of particles at the contact line. Our experiments and the experiments of others demonstrate that this is not accurate physically. In addition, to model the separation of two different sized particles the consideration of thermal effects is essential. © 2015 American Institute of Chemical Engineers AIChE J, 61: 3547–3556, 2015
Total Synthesis of (+)‐Petromyroxol, a Marine Natural Product
Authors: Gahalawat Suraksha , Garg Yuvraj , Pandey Satyendra Kumar
Published: August 2015

An efficient total synthesis of (+)‐petromyroxol, a marine natural product, is described. The synthesis utilizes the Sharpless asymmetric dihydroxylation (AD), intramolecular SN2 cyclization and stereoselective Grignard reaction as key steps.
Organocatalytic Enantioselective Cascade Aza‐Michael/Michael Addition Sequence for Asymmetric Synthesis of Chiral Spiro[pyrrolidine‐3,3′‐oxindole]s
Authors: Zhao Bo‐Liang , Du Da‐Ming
Published: August 2015

The spiro[pyrrolidine‐3,3′‐oxindole] scaffold is common to a range of bioactive compounds; however, the asymmetric synthesis of this scaffold is complicated due to the presence of multiple chiral centers. An organocatalytic asymmetric cascade aza‐Michael/Michael addition between tosylaminomethyl enones or enoates and 3‐ylideneoxindoles catalyzed by a chiral squaramide that afforded complex and flexible spiro[pyrrolidine‐3,3’‐oxindole]s has been developed. Single‐step construction of molecules with three contiguous stereocenters including one quaternary center in excellent yields with highly diastereo‐ and enantioselectivity are rare and should be useful in medicinal chemistry and diversity oriented synthesis of this intriguing class of compounds.
The association between septal deviation and the presence of a maxillary accessory ostium
Authors: Ozel Halil Erdem , Ozdogan Fatih , Esen Erkan , Genc Meliha Gulden , Genc Selahattin , Selcuk Adin
Published: August 2015

Background

The etiology and the effects of the maxillary accessory ostium (MAO) are not well understood. The aim of this study is to investigate the association between septal deviation (SD) and the presence of an MAO.

Methods

Paranasal computed tomography (CT) scans of 1104 adult patients were studied retrospectively. Patients with chronic sinusitis, acute sinusitis, nasal polyposis, allergic rhinitis, paranasal sinus tumors, septal perforation, and unilateral or bilateral maxillary sinus hypoplasia/aplasia, as well as patients who had previously had nasal surgery or a history of nasal trauma, were not included in the study. Eight‐hundred and seven patients were found to meet the criteria and were included in the study. CT scans were examined to note the presence of SD and MAO and the side of both diseases.

Results

A total of 807 patients were evaluated. SD and MAO were detected in 572 (70.9%) and 299 (37.1%) patients, respectively. A statistically significant relationship was found between the presence of SD and MAO, regardless of side of the disease (p = 0.002). The side of MAO showed a significant correlation with the direction of SD (p < 0.001).

Conclusion

Our results revealed a link between SD and MAO. This relationship was correlated with the side of occurrence of the disease.
Electrocatalytic Hydrogen Production by an Aluminum(III) Complex: Ligand‐Based Proton and Electron Transfer
Authors: Thompson Emily J. , Berben Louise A.
Published: August 2015

Environmentally sustainable hydrogen‐evolving electrocatalysts are key in a renewable fuel economy, and ligand‐based proton and electron transfer could circumvent the need for precious metal ions in electrocatalytic H2 production. Herein, we show that electrocatalytic generation of H2 by a redox‐active ligand complex of Al3+ occurs at −1.16 V vs. SCE (500 mV overpotential).
Dual Catalysis for the Redox Annulation of Nitroalkynes with Indoles: Enantioselective Construction of Indolin‐3‐ones Bearing Quaternary Stereocenters
Authors: Liu Ren‐Rong , Ye Shi‐Chun , Lu Chuan‐Jun , Zhuang Gui‐Lin , Gao Jian‐Rong , Jia Yi‐Xia
Published: August 2015

The enantioselective redox annulation of nitroalkynes with indoles is enabled by gold/chiral phosphoric acid dual catalysis. A range of indolin‐3‐one derivatives bearing quaternary stereocenters at the C2 position were afforded in good yields and excellent enantioselectivities (up to 96 % ee) from readily available starting materials.
Rote pyrotechnische Leuchtsätze – ohne Chlor!
Authors: Sabatini Jesse J. , Koch Ernst‐Christian , Poret Jay C. , Moretti Jared D. , Harbol Seth M.
Published: August 2015

Dieser Beitrag behandelt die Entwicklung eines roten, chlorfreien pyrotechnischen Leuchtsatzes hoher Lichtstärke und Farbsättigung. Sätze auf der Grundlage von Mg/Sr(NO3)2/Epon‐Binder werden durch Zusatz von 5‐Amino‐1H‐tetrazol oder Hexamethylentetramin desoxidiert, wodurch die Bildung von rot‐orange emittierendem SrO(g) unterdrückt und die Entstehung des einzigen roten Emitters SrOH gefördert wird. Die neuen Sätze haben hohe Zündtemperaturen. Durch die vollständige Vermeidung von Chlor kann jegliches Risiko der Bildung von PBCs, PCDDs und PCDFs ausgeschlossen werden. Diese Entdeckung hat daher große Bedeutung für die militärische und zivile Pyrotechnik und wird auch den Feuerwerkssektor nachhaltig beeinflussen.
The Methylsulfonyloxyl Radical, CH3SO3
Authors: Zhu Bifeng , Zeng Xiaoqing , Beckers Helmut , Francisco Joseph S. , Willner Helge
Published: August 2015

The methylsulfonyloxyl radical, CH3SO3, one of the key intermediates in the atmospheric oxidation of dimethyl sulfide (DMS), was generated by flash pyrolysis of CH3SO2OOSO2CH3 and subsequently isolated in solid noble‐gas matrices. The radical has been characterized by UV/Vis and IR spectroscopy and its tautomerization to CH2SO3H observed upon irradiation with light of λ≥360 nm.
Improving the antifouling property of poly(vinyl chloride) membranes by poly(vinyl chloride)‐g‐poly(methacrylic acid) as the additive
Authors: Fang Li‐Feng , Zhou Ming‐Yong , Wang Na‐Chuan , Zhu Bao‐Ku , Zhu Li‐Ping
Published: August 2015

To improve the antifouling property of poly(vinyl chloride) (PVC) membranes, a series of poly(methacrylic acid) grafted PVC copolymers (PVC‐g‐PMAA) with different grafting degree were synthesized via one‐step atom transfer radical polymerization process utilizing the labile chlorines on PVC backbones followed by one‐step hydrolysis reaction. PVC/PVC‐g‐PMAA blend membranes with different grafting degree and copolymer content were prepared by nonsolvent induced phase separation method. The surface chemical composition, surface charge, membrane structures, wettability, permeability, separation performances and the fouling resistance of blend membranes were carefully investigated. The results indicated that the PMAA chains were segregated towards the surface and the membranes were endowed with negative charge. The hydrophilicity and permeability of the blend membranes were obviously improved. Furthermore, the antifouling ability especially at neutral or alkaline environments was also significantly increased. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42745.
Thermal and mechanical properties of poly(N‐isopropylacrylamide)‐based hydrogels as a function of porosity and medium change
Authors: Chatterjee Prithwish , Dai Annie , Yu Hongyu , Jiang Hanqing , Dai Lenore L.
Published: August 2015

Poly(N‐isopropylacrylamide) (PNIPAAm) has been a well‐known stimuli–responsive material and has been used in multiple novel applications. One of the key attributes to make the hydrogel more attractive is to control the response time and temperature. This work focused on comparing the physical properties, such as response time, transition temperature, heat of fusion, and mechanical strength, of macroporous and microporous PNIPAAm hydrogels, respectively. It was found that the macroporous hydrogels synthesized from a low‐temperature polymerization with addition of tetramethyl orthosilicate exhibited a faster response time and superior mechanical strength. Furthermore, to modulate the transition temperature, both the macroporous and microporous hydrogels were subjected to different qualities of media by introducing a cosolvent (methanol) or an anionic surfactant (sodium dodecyl sulfate). Interestingly, addition of a cosolvent demonstrated a more pronounced effect on the macroporous hydrogel, whereas the surfactant resulted in a more pronounced effect on the microporous hydrogel. Such results revealed that based on their porosity; there were appreciable differences when the PNIPAAm hydrogels interacted with media molecules. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42776.
Sperm of Galeorhinus galeus (Elasmobranchii, Triakidae) Traverse an Excurrent Duct System Characterized by Pronounced Regionalization: A Scanning Electron and Light Microscopy Study
Authors: McClusky Leon Mendel
Published: August 2015

The transport and subsequent maturation of spermatozoa in the vertebrate excurrent duct require the creation of a series of biochemically defined luminal milieus along the length of the duct. Such specialization is accomplished, among others, by changes in the epididymal histoarchitecture. Here we show that the intratesticular and extratesticular genital ducts of mating Galeorhinus galeus exhibit pronounced regionalization both in terms of epithelial histology and lumen diameter size. Findings also reveal distinct differences in the manner in which the spermatozoa were found in each segment of the duct. Novel scanning electron microscopy evidence is presented showing that the wide lumen ductuli epididymides, which ultimately convey the spermatozoa to the proximal epididymis, show functional specialization as well. The wall of the former consisted of cuboidal ciliated and nonciliated cells whose spatial arrangement in the duct wall resulted in a luminal surface showing lengthy rows of cilia‐free areas, with each row bordered on both sides by a single row of cilia. The proximal epididymis comprised several subregions whose epithelial histology varied widely. The distal epididymis and ampulla of the epididymis possessed many fingerlike projections and transverse septa, respectively. As the main storage site for spermatozoa, the ampulla completed the bundling of spermatozoa into spermatozeugmata. These were circular sperm masses in which the heads of the spermatozoa were aligned side by side and embedded in a seminal matrix, while their tails extended outward. These findings of pronounced regionalization differ greatly from the rather uniform epididymal histology seen in some rays. Anat Rec, 298:1938–1949, 2015. © 2015 Wiley Periodicals, Inc.
Hypertension and Estrogen Deficiency Augment Aneurysmal Remodeling in the Rabbit Circle of Willis in Response to Carotid Ligation
Authors: Tutino Vincent M. , Mandelbaum Max , Takahashi Akira , Pope Liza C. , Siddiqui Adnan , Kolega John , Meng Hui
Published: August 2015

Increased cerebral blood flow has been shown to induce pathological structural changes in the Circle of Willis (CoW) in experimental models. Previously, we reported flow‐induced aneurysm‐like remodeling in the CoW secondary to flow redistribution after bilateral common carotid artery (CCA) ligation in rabbits. In the current study, we tested the hypothesis that loading rabbits with biological risk factors for vascular disease would increase flow‐induced aneurysmal remodeling in the CoW. In the same series as the previously‐reported bilateral CCA‐ligation‐alone (n = 6) and sham surgery (n = 3) groups, eight additional female rabbits (the experimental group in this study) were subjected to two risk factors for intracranial aneurysm (hypertension and estrogen deficiency) and then bilateral CCA ligation. Upon euthanasia at 6 months, vascular corrosion casts of the CoW were created and analyzed by scanning electron microscopy for morphological changes and aneurysmal damage. In rabbits with hypertension and estrogen deficiency, arterial caliber increased throughout the CoW, similar to rabbits with CCA ligation alone. However, aneurysmal remodeling (i.e., local bulging) in the CoW was significantly greater than in CCA‐ligation‐only rabbits and was more widespread, presenting in regions that did not show aneurysmal changes after CCA ligation alone. Furthermore, hypertension and estrogen deficiency caused greater increases in vessel length and tortuosity. These results suggest that hypertension and estrogen deficiency make the CoW more vulnerable to flow‐induced aneurysmal remodeling and tortuosity. We propose they do so by lowering the tolerance of vascular tissue to hemodynamic forces caused by CCA ligation, thus lowering the threshold necessary to incite vascular damage. Anat Rec, 298:1903–1910, 2015. © 2015 Wiley Periodicals, Inc.
BAPX‐1/NKX‐3.2 Acts as a Chondrocyte Hypertrophy Molecular Switch in Osteoarthritis
Authors: Caron Marjolein M. J. , Emans Pieter J. , Surtel Don A. M. , van der Kraan Peter M. , van Rhijn Lodewijk W. , Welting Tim J. M.
Published: August 2015

Objective

Osteoarthritis (OA) development involves a shift of the articular chondrocyte phenotype toward hypertrophic differentiation via still poorly characterized mechanisms. The purpose of this study was to test our hypothesis that the function of BAPX‐1/NKX‐3.2 is impaired in OA chondrocytes and leads directly to loss of hypertrophic protection of the articular chondrocyte, which is central in the changing chondrocyte phenotype that drives OA.

Methods

Human articular chondrocytes (HACs; from healthy and OA donors) and SW‐1353 chondrocytic cells were exposed to bone morphogenetic protein 7 (BMP‐7), interleukin‐1β (IL‐1β), tumor necrosis factor, or OA synovial fluid (SF; 20% [volume/volume]). Loss‐of‐function and gain‐of‐function experiments for BAPX‐1/NKX‐3.2 were performed. Mouse experimental models of OA were used, and (immuno)histochemistry of tissue sections was performed. Gene and protein expression of BAPX‐1/NKX‐3.2 and chondrogenic, hypertrophic, and OA‐related mediators were determined by real‐time quantitative polymerase chain reaction analysis and immunoblotting. In addition, alkaline phosphatase (AP) activity and prostaglandin E2 levels were measured.

Results

BAPX‐1/NKX‐3.2 expression correlated negatively with expression of chondrocyte hypertrophic markers (RUNX‐2, COL10A1, AP), cartilage‐degrading enzymes (matrix metalloproteinase 13, ADAMTS‐5), and mediators of inflammation (cyclooxygenase 2, IL‐6) in healthy and OA chondrocytes, as well as in OA induced chondrocytes. BAPX‐1/NKX‐3.2 positivity was diminished in articular chondrocytes in the knee joints of mice with experimental OA. Knockdown of BAPX‐1/NKX‐3.2 in HACs did not influence the expression of SOX9, COL2A1, or aggrecan, but led to an acute hypertrophic shift in the HAC phenotype. Overexpression of BAPX‐1/NKX‐3.2 decreased hypertrophic gene expression in HACs. Furthermore, the hypertrophic OA chondrocyte phenotype could be counteracted by overexpression of BAPX‐1/NKX‐3.2 and by BMP‐7 in a BAPX‐1/NKX‐3.2 dependent manner.

Conclusion

Our findings indicate that BAPX‐1/NKX‐3.2 is a molecular switch that is involved in controlling the hypertrophic phenotype of the postdevelopmental (OA) articular chondrocyte.
Neutrophil Extracellular Trap Mitochondrial DNA and Its Autoantibody in Systemic Lupus Erythematosus and a Proof‐of‐Concept Trial of Metformin
Authors: Wang Haiting , Li Ting , Chen Sheng , Gu Yueying , Ye Shuang
Published: August 2015

Objective

Neutrophil extracellular traps (NETs) have been shown to play an important role in systemic lupus erythematosus (SLE) pathogenesis by activating plasmacytoid dendritic cells (PDCs) and the type I interferon (IFN) pathway. NETs composed of self‐DNA are considered to be of nuclear origin and are a major source of anti‐DNA autoantibody generation. This study was undertaken to evaluate whether mitochondrial DNA (mtDNA) resides in NETs, to evaluate whether mtDNA and anti‐mtDNA antibodies cause dysregulation of the PDC–IFNα pathway, and to investigate the clinical implication in SLE.

Methods

Patients with SLE (n = 102), patients with rheumatoid arthritis (n = 30), and healthy donors (n = 40) were enrolled in in vitro studies. NETs were generated from phorbol 12‐myristate 13‐acetate (PMA)–stimulated peripheral neutrophils. Immunofluorescence staining was used to detect NET formation ex vivo and in lupus nephritis renal biopsy samples. The mtDNA levels and type I IFN–inducible gene scores were measured by quantitative polymerase chain reaction. Anti‐mtDNA antibodies, anti–double‐stranded DNA (anti–dsDNA) antibodies, and IFNα were detected by enzyme‐linked immunosorbent assay. Purified PDCs were stimulated by isolated NETs, mtDNA, or dsDNA, combined with anti‐mtDNA or dsDNA IgG, or other culture conditions. Additional patients with SLE (n = 113) were enrolled in a proof‐of‐concept trial. We evaluated the efficacy and safety of metformin on a background of corticosteroids and conventional immunosuppressive agents in patients with mild or moderate lupus. The primary end point was the efficacy of metformin for reducing disease flare.

Results

We detected mtDNA in NETs, and anti‐mtDNA antibody levels were elevated in SLE patients compared with controls and significantly correlated with IFN scores and the disease activity index. The presence of anti‐mtDNA antibodies was disproportionately associated with lupus nephritis, and correlated better than anti‐dsDNA antibody levels with the lupus nephritis activity index. Mitochondrial DNA was deposited in NETs in lupus nephritis renal biopsy specimens. In addition, mtDNA/anti‐mtDNA were greater inducers of PDC IFNα production via Toll‐like receptor engagement than dsDNA/anti‐dsDNA. We assessed the effect of metformin on down‐regulating the NET mtDNA–PDC–IFNα pathway. Metformin decreased PMA‐induced NET formation and CpG‐stimulated PDC IFNα generation. A proof‐of‐concept trial of metformin add‐on treatment of mild or moderate SLE resulted in decreases in clinical flares, prednisone exposure, and body weight.

Conclusion

Our findings establish a link between mtDNA in NETs, anti‐mtDNA antibodies, and PDC IFNα pathogenesis in SLE, and highlight that specific strategies to down‐regulate this pathway, such as treatment with metformin, may be new approaches to treat SLE.
Interpretation of an Extended Autoantibody Profile in a Well‐Characterized Australian Systemic Sclerosis (Scleroderma) Cohort Using Principal Components Analysis
Authors: Patterson K. A. , Roberts‐Thomson P. J. , Lester S. , Tan J. A. , Hakendorf P. , Rischmueller M. , Zochling J. , Sahhar J. , Nash P. , Roddy J. , Hill C. , Nikpour M. , Stevens W. , Proudman S. M. , Walker J. G.
Published: August 2015

Objective

To determine the relationships between systemic sclerosis (SSc)–related autoantibodies, as well as their clinical associations, in a well‐characterized Australian patient cohort.

Methods

Serum from 505 Australian SSc patients were analyzed with a commercial line immunoassay (EuroLine; Euroimmun) for autoantibodies to centromere proteins CENP‐A and CENP‐B, RNA polymerase III (RNAP III; epitopes 11 and 155), the 90‐kd nucleolar protein NOR‐90, fibrillarin, Th/To, PM/Scl‐75, PM/Scl‐100, Ku, topoisomerase I (topo I), tripartite motif–containing protein 21/Ro 52, and platelet‐derived growth factor receptor. Patient subgroups were identified by hierarchical clustering of the first 2 dimensions of a principal components analysis of quantitative autoantibody scores. Results were compared with detailed clinical data.

Results

A total of 449 of the 505 patients were positive for at least 1 autoantibody by immunoblotting. Heatmap visualization of autoantibody scores, along with principal components analysis clustering, demonstrated strong, mutually exclusive relationships between CENP, RNAP III, and topo I. Five patient clusters were identified: CENP, RNAP III strong, RNAP III weak, topo I, and other. Clinical features associated with CENP, RNAP III, and topo I were consistent with previously published reports concerning limited cutaneous and diffuse cutaneous SSc. A novel finding was the statistical separation of RNAP III into 2 clusters. Patients in the RNAP III strong cluster had an increased risk of gastric antral vascular ectasia, but a lower risk of esophageal dysmotility. Patients in the other cluster were more likely to be male and to have a history of smoking and a history of malignancy, but were less likely to have telangiectasia, Raynaud's phenomenon, and joint contractures.

Conclusion

Five major autoantibody clusters with specific clinical and serologic associations were identified in Australian SSc patients. Subclassification and disease stratification using autoantibodies may have clinical utility, particularly in early disease.
Easy Access to Supramolecular Gels of the Nonsteroidal Anti‐inflammatory Drug Diflunisal: Synthesis, Characterization, and Plausible Biomedical Applications
Authors: Parveen Rumana , Dastidar Parthasarathi
Published: August 2015

By exploiting salt formation, a new series of primary ammonium monocarboxylate salts of a nonsteroidal anti‐inflammatory drug, namely, diflunisal, was synthesized. The majority of the salts thus synthesized turned out to be good gelators of various solvents, including the solvents (e.g., methyl salicylate and pure water) typically used for topical gel formulation. Single‐crystal X‐ray diffraction studies of a few gelator and nongelator salts in the series revealed details of the hydrogen‐bonding networks present in the salts. Furthermore, one such gelator salt, namely, the diflunisal salt of serinol, was found to be biocompatible (MTT assay), and its anti‐inflammatory (PGE2 assay) response turned out to be as good as that of the parent drug, which is indicative of its potential in biomedical applications.
Connection of predictability of major stratospheric sudden warmings to polar vortex geometry
Authors: Taguchi Masakazu
Published: August 2015

This study explores a possible connection between predictability variations of major stratospheric sudden warmings (MSSWs) during Northern winter and the geometry of the polar vortex. We compare 1‐month hindcasts from 1979 to 2012 of the Japan Meteorological Agency to the Japanese 55‐year Reanalysis data. Results show that error variations of medium range (≈14 day) forecasts of 21 actual MSSWs do depend on the observed geometry of the polar vortex: the errors are larger for vortex split MSSWs when the polar vortex is highly stretched as characterized by a high aspect ratio and an amplified zonal wavenumber 2 component.
Orthogonal collocation methods using Mathematica© in the graduate chemical engineering curriculum
Authors: Binous Housam , Bellagi Ahmed
Published: August 2015

We present in this pedagogical paper several important aspects of the application of orthogonal collocation for solution of Chemical Engineering problems. These include: the Stefan–Maxwell diffusion; the start‐up of a Poiseuille Flow in a Newtonian Fluid; the transient heat conduction with temperature‐dependent thermal conductivity; and the reaction‐diffusion in a drop. The presented method of resolution (i.e., orthogonal collocation) of such problems can be easily introduced in any graduate‐level chemical engineering numerical method course. Indeed, this technique has been used for the past four year at King Fahd University of Petroleum & Minerals (KFUPM) in the graduate‐level core numerical methods course called CHE 560. © 2015 Wiley Periodicals, Inc. Comput. Appl. Eng. Educ. 24:101–113, 2016; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21676
Constructions of ‘Illegal’ Immigration and Entitlement to Citizenship: Debating an Immigration Law in Greece
Authors: Figgou Lia
Published: August 2015

This study explores the ways in which constructions of immigrants' illegality and accounts on the meaning of naturalization and citizenship serve as argumentative resources against a particular immigration law in Greece. Data consisted of transcripts of parliamentary speeches by political party leaders who opposed the law. Analysis used the tools and concepts of discursive and rhetorical social psychology and identified three main lines of arguing. The first set clear boundaries between ‘legal’ and ‘illegal’ immigration and constructed immigrants' (il)legal entry as a category defining criterion. The second represented legal status as subject to change and constructed immigrants as ‘legalized’, in order to argue against their entitlement to citizenship. Finally, in another sort of accounting, regularization and naturalization procedures were trivialized, as the speakers negotiated the necessary, and also the ideal conditions of co‐existence and participation in a nation–state. The findings are discussed in relation to their potential contribution (i) to the existing literature on the constituted and constitutive nature of the category of illegal immigration and (ii) to a social psychological approach to citizenship. Copyright © 2015 John Wiley & Sons, Ltd.
Synthetic Model of the Oxygen‐Evolving Center: Photosystem II under the Spotlight
Authors: Yu Yang , Hu Cheng , Liu Xiaohong , Wang Jiangyun
Published: August 2015

The oxygen‐evolving center (OEC) in photosystem II catalyzes a water splitting reaction. Great efforts have already been made to artificially synthesize the OEC, in order to elucidate the structure‐function relationship and the mechanism of the reaction. Now, a new synthetic model makes the best mimic yet of the OEC. This recent study opens up the possibility to study the mechanism of photosystem II and photosynthesis in general for applications in renewable energy and synthetic biology.