bluuebunny/crossref_metadata_2025 huggingface dataset:
Dissolved black carbon in Antarctic lakes: Chemical signatures of past and present sources
Authors: Khan Alia L. , Jaffé Rudolf , Ding Yan , McKnight Diane M.
Published: May 2016

The perennially ice‐covered, closed‐basin lakes in the McMurdo Dry Valleys, Antarctica, serve as sentinels for understanding the fate of dissolved black carbon from glacial sources in aquatic ecosystems. Here we show that dissolved black carbon can persist in freshwater and saline surface waters for thousands of years, while preserving the chemical signature of the original source materials. The ancient brines of the lake bottom waters have retained dissolved black carbon with a woody chemical signature, representing long‐range transport of black carbon from wildfires. In contrast, the surface waters are enriched in contemporary black carbon from fossil fuel combustion. Comparison of samples collected 25 years apart from the same lake suggests that the enrichment in anthropogenic black carbon is recent. Differences in the chemical composition of dissolved black carbon among the lakes are likely due to biogeochemical processing such as photochemical degradation and sorption on metal oxides.
Reproducing the observed energy‐dependent structure of Earth's electron radiation belts during storm recovery with an event‐specific diffusion model
Authors: Ripoll J.‐F. , Reeves G. D. , Cunningham G. S. , Loridan V. , Denton M. , Santolík O. , Kurth W. S. , Kletzing C. A. , Turner D. L. , Henderson M. G. , Ukhorskiy A. Y.
Published: May 2016

We present dynamic simulations of energy‐dependent losses in the radiation belt “slot region” and the formation of the two‐belt structure for the quiet days after the 1 March storm. The simulations combine radial diffusion with a realistic scattering model, based data‐driven spatially and temporally resolved whistler‐mode hiss wave observations from the Van Allen Probes satellites. The simulations reproduce Van Allen Probes observations for all energies and L shells (2–6) including (a) the strong energy dependence to the radiation belt dynamics (b) an energy‐dependent outer boundary to the inner zone that extends to higher L shells at lower energies and (c) an “S‐shaped” energy‐dependent inner boundary to the outer zone that results from the competition between diffusive radial transport and losses. We find that the characteristic energy‐dependent structure of the radiation belts and slot region is dynamic and can be formed gradually in ~15 days, although the “S shape” can also be reproduced by assuming equilibrium conditions. The highest‐energy electrons (E > 300 keV) of the inner region of the outer belt (L ~ 4–5) also constantly decay, demonstrating that hiss wave scattering affects the outer belt during times of extended plasmasphere. Through these simulations, we explain the full structure in energy and L shell of the belts and the slot formation by hiss scattering during storm recovery. We show the power and complexity of looking dynamically at the effects over all energies and L shells and the need for using data‐driven and event‐specific conditions.
Methane fluxes from the sea to the atmosphere across the Siberian shelf seas
Authors: Thornton Brett F. , Geibel Marc C. , Crill Patrick M. , Humborg Christoph , Mörth Carl‐Magnus
Published: May 2016

The Laptev and East Siberian Seas have been proposed as a substantial source of methane (CH4) to the atmosphere. During summer 2014, we made unique high‐resolution simultaneous measurements of CH4 in the atmosphere above, and surface waters of, the Laptev and East Siberian Seas. Turbulence‐driven sea‐air fluxes along the ship's track were derived from these observations; an average diffusive flux of 2.99 mg m−2 d−1 was calculated for the Laptev Sea and for the ice‐free portions of the western East Siberian Sea, 3.80 mg m−2 d−1. Although seafloor bubble plumes were observed at two locations in the study area, our calculations suggest that regionally, turbulence‐driven diffusive flux alone accounts for the observed atmospheric CH4 enhancements, with only a local, limited role for bubble fluxes, in contrast to earlier reports. CH4 in subice seawater in certain areas suggests that a short‐lived flux also occurs annually at ice‐out.
Driving ionospheric outflows and magnetospheric O+ energy density with Alfvén waves
Authors: Chaston C. C. , Bonnell J. W. , Reeves G. D. , Skoug R. M.
Published: May 2016

We show how dispersive Alfvén waves observed in the inner magnetosphere during geomagnetic storms can extract O+ ions from the topside ionosphere and accelerate these ions to energies exceeding 50 keV in the equatorial plane. This occurs through wave trapping, a variant of “shock” surfing, and stochastic ion acceleration. These processes in combination with the mirror force drive field‐aligned beams of outflowing ionospheric ions into the equatorial plane that evolve to provide energetic O+ distributions trapped near the equator. These waves also accelerate preexisting/injected ion populations on the same field lines. We show that the action of dispersive Alfvén waves over several minutes may drive order of magnitude increases in O+ ion pressure to make substantial contributions to magnetospheric ion energy density. These wave accelerated ions will enhance the ring current and play a role in the storm time evolution of the magnetosphere.
Decadal trends in air‐sea CO2 exchange in the Ross Sea (Antarctica)
Authors: Tagliabue Alessandro , Arrigo Kevin R.
Published: May 2016

Highly productive Antarctic shelf systems, like the Ross Sea, play important roles in regional carbon budgets, but the drivers of local variations are poorly quantified. We assess the variability in the Ross Sea carbon cycle using a regional physical‐biogeochemical model. Regionally, total partial pressure of CO2 (pCO2) increases are largely controlled by the biological pump and broadly similar to those in the offshore Southern Ocean. However, this masks substantial local variability within the Ross Sea, where interannual fluctuations in total pCO2 are driven by the biological pump and alkalinity, whereas those for anthropogenic pCO2 are related to physical processes. Overall, the high degree of spatial variability in the Ross Sea carbon cycle causes extremes in aragonite saturation that can be as large as long‐term trends. Therefore, Antarctic shelf polynya systems like the Ross Sea will be strongly affected by local processes in addition to larger‐scale phenomena.
Unaccounted variability in NH3 agricultural sources detected by IASI contributing to European spring haze episode
Authors: Fortems‐Cheiney A. , Dufour G. , Hamaoui‐Laguel L. , Foret G. , Siour G. , Van Damme M. , Meleux F. , Coheur P.‐F. , Clerbaux C. , Clarisse L. , Favez O. , Wallasch M. , Beekmann M.
Published: May 2016

Ammonia (NH3), whose main source in the troposphere is agriculture, is an important gaseous precursor of atmospheric particulate matter (PM). We derived daily ammonia emissions using NH3 total columns measured from the Infrared Atmospheric Sounding Interferometer (IASI) on board Metop‐A, at a relatively high spatial resolution (grid cell of 0.5° × 0.5°). During the European spring haze episodes of 24–31 March 2012 and 8–15 March 2014, IASI reveals NH3 total column magnitudes highlighting higher NH3 emissions over central Europe (especially over Germany, Czech Republic, and eastern France) from the ones provided by the European reference European Monitoring and Evaluation Programme inventory. These ammonia emissions exhibit in addition a large day‐to‐day variability, certainly due to spreading practices. The increase of NH3 emissions in the model, that reaches +300% locally, leads to an increase of both NH3 and PM2.5 surface concentrations and allows for a better comparison with independent measurements (in terms of bias, root‐mean‐square error, and correlation). This study suggests that there are good prospects for better quantifying NH3 emissions by atmospheric inversions.
Thicknesses of mare basalts on the Moon from gravity and topography
Authors: Gong Shengxia , Wieczorek Mark A. , Nimmo Francis , Kiefer Walter S. , Head James W. , Huang Chengli , Smith David E. , Zuber Maria T.
Published: May 2016

A new method of determining the thickness of mare basalts on the Moon is introduced that is made possible by high‐resolution gravity data acquired from NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission. Using a localized multitaper spherical‐harmonic analysis, an effective density spectrum is calculated that provides an estimate of the average crustal density as a function of spherical harmonic degree. By comparing the observed effective density spectrum with one generated from a theoretical model, the thickness of mare basalts can be constrained. We assume that the grain density of the basalts is known from remote sensing data and petrologic considerations, we assign a constant porosity to the basalts, and we let both the thickness of the basalts and the density of the underlying crust vary. Using this method, the total thickness of basalts was estimated on the nearside hemisphere, yielding an average of 0.74 km with 1σ upper and lower bounds of 1.62 km and 100 m, respectively. The region of Marius Hills, which is a long‐lived volcanic complex, is found to have the thickest basalts, with an average of 2.86 km and 1σ limits of 3.65 and 1.02 km, respectively. The crust beneath the Mare Imbrium basalts is found to have an atypically high density of about 3000 kg m−3 that we interpret as representing a mafic, unfractured, impact melt sheet.
Toward Flexible Spintronics: Perpendicularly Magnetized Synthetic Antiferromagnetic Thin Films and Nanowires on Polyimide Substrates
Authors: Vemulkar T. , Mansell R. , Fernández‐Pacheco A. , Cowburn R. P.
Published: May 2016

The successful fabrication of ultra‐thin films of CoFeB/Pt with strong perpendicular magnetic anisotropy and antiferromagnetic interfacial interlayer coupling on flexible polyimide substrates is demonstrated. Despite an increased surface roughness and defect density on the polyimide substrate, magnetic single layers of CoFeB still show sharp coercive switching. Magnetic Kerr imaging shows that the magnetization reversal is dominated by a greater density of nucleation sites than the identical film grown on Si. These layers maintain their magnetic characteristics down to a radius of curvature of 350 ± µm. Further, antiferromagnetically (AF) Ruderman‐Kittel‐Kasuya‐Yoshida (RKKY) coupled bilayers of CoFeB were fabricated which are robust under bending and the coupling strength is successfully modulated via interlayer engineering. Finally, a perpendicular synthetic antiferromagnetic (SAF) thin film grown on a polyimide substrate is patterned into straight 10 µm long nanowires down to 210 nm in width that displayed the robust switching characteristics of the thin film. These are extremely promising results for the fabrication of robust, flexible, magneto‐electronic, non‐volatile memory, logic, and sensor devices.
Elastic Carbon Nanotube Aerogel Meets Tellurium Nanowires: A Binder‐ and Collector‐Free Electrode for Li‐Te Batteries
Authors: Xu Jie , Xin Sen , Liu Jian‐Wei , Wang Jin‐Long , Lei Yong , Yu Shu‐Hong
Published: May 2016

Rechargeable Li batteries based on group VIA element cathodes, such as tellurium, are emerging due to their capability to provide equivalent theoretical volumetric capacity density to O and S, as well as an improved activity to react with Li. Herein, bifunctional and elastic carbon nanotube (CNT) aerogel is fabricated to combine with Te nanowires, yielding two types of binder/collector‐free Te cathodes to assemble Li‐Te batteries. The CNTs with high electronic conductivity and hollow porous structure enable stable electric contact and fast transportation of Li+, while trapping Te and Li2Te in its network, triggering fast and stable Li‐Te electrochemistry. Both cathodes are also provided with fine compressibility, helping to buffer their volume changes during lithiation/delithiation and improving electrode integrity. Both cathodes deliver high specific capacity, fine cycling stability, and favorable high‐rate capability, proving their competence in building high‐energy rechargeable Li‐ion batteries.
Heterogeneous Catalysis for Water Oxidation by an Iridium Complex Immobilized on Bipyridine‐Periodic Mesoporous Organosilica
Authors: Liu Xiao , Maegawa Yoshifumi , Goto Yasutomo , Hara Kenji , Inagaki Shinji
Published: May 2016

Heterogenization of metal‐complex catalysts for water oxidation without loss of their catalytic activity is important for the development of devices simulating photosynthesis. In this study, efficient heterogeneous iridium complexes for water oxidation were prepared using bipyridine‐bridged periodic mesoporous organosilica (BPy‐PMO) as a solid chelating ligand. The BPy‐PMO‐based iridium catalysts (Ir‐BPy‐PMO) were prepared by postsynthetic metalation of BPy‐PMO and characterized through physicochemical analyses. The Ir‐BPy‐PMOs showed high catalytic activity for water oxidation. The turnover frequency (TOF) values for Ir‐BPy‐PMOs were one order of magnitude higher than those of conventional heterogeneous iridium catalysts. The reusability and stability of Ir‐BPy‐PMO were also examined, and detailed characterization was conducted using powder X‐ray diffraction, nitrogen adsorption, 13C DD MAS NMR spectroscopy, TEM, and XAFS methods.
Stereoselektive arenbildende Aldolkondensation: Synthese axial‐chiraler aromatischer Amide
Authors: Fäseke Vincent C. , Sparr Christof
Published: May 2016

Das zunehmende Bewusstsein über die Bedeutung von Amid‐Atropisomeren erfordert die Entwicklung neuer Strategien für ihre selektive Herstellung. Hier wird eine enantioselektive Synthese aromatischer Amide durch die Amin‐katalysierte, arenbildende Aldolkondensation beschrieben. Die hohe Reaktivität von Glyoxylamid‐Substraten ermöglicht einen bemerkenswert effizienten Aufbau eines neuen aromatischen Ringes, der bei Raumtemperatur innerhalb von Minuten mit exzellenter Stereoselektivität erfolgt. Die hohen Rotationsbarrieren der reduzierten Produkte verdeutlichen den Nutzen dieser stabilen, räumlich geordneten, chiralen Bausteine.
Full Kinetics from First Principles of the Chlorine Evolution Reaction over a RuO2(110) Model Electrode
Authors: Exner Kai S. , Anton Josef , Jacob Timo , Over Herbert
Published: May 2016

Current progress in modern electrocatalysis research is spurred by theory, frequently based on ab initio thermodynamics, where the stable reaction intermediates at the electrode surface are identified, while the actual energy barriers are ignored. This approach is popular in that a simple tool is available for searching for promising electrode materials. However, thermodynamics alone may be misleading to assess the catalytic activity of an electrochemical reaction as we exemplify with the chlorine evolution reaction (CER) over a RuO2(110) model electrode. The full procedure is introduced, starting from the stable reaction intermediates, computing the energy barriers, and finally performing microkinetic simulations, all performed under the influence of the solvent and the electrode potential. Full kinetics from first‐principles allows the rate‐determining step in the CER to be identified and the experimentally observed change in the Tafel slope to be explained.
Unveiling the Biosynthetic Pathway of the Ribosomally Synthesized and Post‐translationally Modified Peptide Ustiloxin B in Filamentous Fungi
Authors: Ye Ying , Minami Atsushi , Igarashi Yuya , Izumikawa Miho , Umemura Myco , Nagano Nozomi , Machida Masayuki , Kawahara Teppei , Shin‐ya Kazuo , Gomi Katsuya , Oikawa Hideaki
Published: May 2016

The biosynthetic machinery of the first fungal ribosomally synthesized and post‐translationally modified peptide (RiPP) ustiloxin B was elucidated through a series of gene inactivation and heterologous expression studies. The results confirmed an essential requirement for novel oxidases possessing the DUF3328 motif for macrocyclization, and highly unique side‐chain modifications by three oxidases (UstCF1F2) and a pyridoxal 5′‐phosphate (PLP)‐dependent enzyme (UstD). These findings provide new insight into the expression of the RiPP gene clusters found in various fungi.
Isolation and Asymmetric Total Synthesis of Perforanoid A
Authors: Lv Chao , Yan Xiaohui , Tu Qian , Di Yingtong , Yuan Chunmao , Fang Xin , Ben‐David Yaacove , Xia Lei , Gong Jianxian , Shen Yuemao , Yang Zhen , Hao Xiaojiang
Published: May 2016

A novel limonoid, perforanoid A, was isolated, and an asymmetric total synthesis was achieved in 10 steps. The key steps are chiral tertiary aminonaphthol mediated enantioselective alkenylation of an aldehyde to an allylic alcohol, Pd‐catalyzed coupling of the allylic alcohol with vinyl ether to form the γ‐lactone ring, and cyclopentenone ring formation through a Rh‐catalyzed Pauson–Khand reaction. Preliminary studies show that perforanoid A is cytotoxic towards HEL, K562, and CB3 tumor cell lines.
An In‐tether Chiral Center Modulates the Helicity, Cell Permeability, and Target Binding Affinity of a Peptide
Authors: Hu Kuan , Geng Hao , Zhang Qingzhou , Liu Qisong , Xie Mingsheng , Sun Chengjie , Li Wenjun , Lin Huacan , Jiang Fan , Wang Tao , Wu Yun‐Dong , Li Zigang
Published: May 2016

The addition of a precisely positioned chiral center in the tether of a constrained peptide is reported, yielding two separable peptide diastereomers with significantly different helicity, as supported by circular dichroism (CD) and NMR spectroscopy. Single crystal X‐ray diffraction analysis suggests that the absolute configuration of the in‐tether chiral center in helical form is R, which is in agreement with theoretical simulations. The relationship between the secondary structure of the short peptides and their biochemical/biophysical properties remains elusive, largely because of the lack of proper controls. The present strategy provides the only method for investigating the influence of solely conformational differences upon the biochemical/biophysical properties of peptides. The significant differences in permeability and target binding affinity between the peptide diastereomers demonstrate the importance of helical conformation.
Gold(I)‐Catalyzed Generation of the Two Components of a Formal [4+2] Cycloaddition Reaction for the Synthesis of Tetracyclic Pyrano[2,3,4‐de]chromenes
Authors: Arto Tamara , Fañanás Francisco J. , Rodríguez Félix
Published: May 2016

Ortho‐Alkynylbenzaldehydes have been widely used to generate isochromenylium derivatives through gold‐catalyzed cycloisomerization. These isochromenylium derivatives have been exploited as formal diene derivatives for reactions with different dienophiles. Herein, we describe the behavior of ortho‐alkynylsalicylaldehydes, a particular case of ortho‐alkynylbenzaldehydes. The gold‐catalyzed cycloisomerization of ortho‐alkynylsalicylaldehydes delivers an unusual heterodiene derivative that reacts with electron‐rich alkenes through a formal [4+2] cycloaddition. In this reaction, both the diene and dienophile are generated in situ through gold‐catalyzed cycloisomerization of appropriate alkynamines or alkynols. This reaction was used to synthesize complex tetracyclic pyrano[2,3,4‐de]chromenes from two very simple starting materials (an ortho‐alkynylsalicylaldehyde and an alkynamine or alkynol) with complete atom economy and with selective formation of bonds, cycles, and stereocenters.
Immobilization of phosphotungstic acid in an amino‐containing metal–organic framework for oxidative desulfurization
Authors: Zhang Liwei , Wu Songhai , Liu Yong , Wang Feifei , Han Xu , Shang Hongyu
Published: May 2016

A composite material has been successfully synthesized using an amino‐containing metal–organic framework (NH2‐MOF) and phosphotungstic acid (PTA). This composite was characterized using X‐ray diffraction, high‐resolution transmission electron microscopy, nitrogen adsorption–desorption measurements, Fourier transform infrared spectroscopy and X‐ray fluorescence. Characterization results confirmed the immobilization and good distribution of PTA in the NH2‐MOF. The PTA/NH2‐MOF was subsequently applied in the oxidative desulfurization of dibenzothiophene (DBT) with H2O2 as the oxidant in n‐octane under atmospheric conditions. Under optimal reaction conditions, the oxidative desulfurization conversion of DBT reached 100%, and there was no significant decrease of the catalytic activity after four recycles. Kinetic experiments were also performed for the reaction at various temperatures, which indicated that oxidative reaction rates followed pseudo first‐order kinetics, and the apparent activation energy for the desulfurization reaction was 34.1 kJ mol−1. The results indicated that this material exhibited excellent catalytic performance for oxidative desulfurization of DBT. Copyright © 2016 John Wiley & Sons, Ltd.
Structure and properties of poly(lactic acid)/poly(ε‐caprolactone) nanocomposites with kinetically induced nanoclay location
Authors: Urquijo J. , Dagréou S. , Guerrica‐Echevarría G. , Eguiazábal J. I.
Published: May 2016

Poly(lactic acid)/poly(ε‐caprolactone)/organically modified montmorillonite (PLA/PCL/OMMT) nanocomposites were melt‐processed in a twin‐screw extruder under high shear conditions. As a result of the processing conditions employed, the OMMT layers located in the less compatible PCL phase in all the ternary nanocomposites. The morphology of the PLA/PCL blend evolved from “sea‐island” to co‐continuous upon the addition of OMMT. Both the X‐ray diffraction (XRD) and viscoelastic characterization suggested similar OMMT dispersion in the reference PLA binary and in the PLA/PCL ternary nanocomposites, regardless of its location in the PLA and PCL phase, respectively. The reinforcing effect of the organoclay was also similar. The addition of OMMT to the PLA/PCL blend fully compensated the loss in stiffness and oxygen barrier performance produced by PCL in PLA; the nanocomposite with 3% OMMT showed the same modulus and permeability values as those of pure PLA. Moreover, the ductile behavior (elongation at break > 80%) of the PLA/PCL blend remained constant even in the nanocomposite containing 5% OMMT. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43815.
Biopolyol preparation from liquefaction of grape seeds
Authors: Shao Qiang , Li Hong‐Qiang , Huang Chong‐Pin , Xu Jian
Published: May 2016

The feasibility of liquefying grape seeds (GS) in the blended solvents of PEG 400 and glycerol for the production of biopolyol was investigated. Different liquefaction conditions have great influences on the residue ratio of GS. The influences of the liquefaction condition such as temperature, time, catalyst percentage, and liquid–solid ratio on the residue ratio were discussed. The optimal conditions obtained were 180  °C, 120 min, catalyst percentage (percentage of solvent mass) of 3.5%, and liquid–solid ratio of 4. The FTIR showed that the lignin, cellulose, and hemicellulose in the GS were effectively decomposed in the liquefaction process. The characteristic parameters of the biopolyol were as follows: hydroxyl number of 397.46 mg KOH/g, acid number of 1.85 mg KOH/g, viscosity of 2960 mPa·s, weight‐average molecular weight of 5.18 × 103 g mol−1, and polydispersity of 3.64. These results suggest that the GS‐based polyol was suitable for the production of polyurethane foams. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43835.
Effect of coupling agent on structure and properties of micro–nano composite fibers based on PET
Authors: Jiang Zhaohui , Ma Pibo , Guo Zengge , Jia Zhao , Pu Congcong , Xiao Changfa
Published: May 2016

Poly(ethylene terephthalate) (PET)/carbon black (CB) micro–nano composite fibers were manufactured by melt spinning method. To achieve good dispersion, nano‐CB particles were modified by coupling agent (CA). The effect of CA on structure and properties of the fibers were investigated via scanning electron microscopy (SEM), tensile testing, differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (WAXD), sonic orientation, and birefringence, respectively. At 2 wt % CA dosage, CB particles present the optimal dispersion in the fibers, shown in SEM images. Besides, the fibers possess the maximum breaking strength, the lowest crystallization temperature, and the highest crystallinity. After CA modification, the superior interfacial structure between PET and CB is beneficial to improve mechanical properties of the fibers. The well dispersed CB particles provide more heterogeneous nucleation points, resulting in the highest crystallinity. Furthermore, the fibers with 2 wt % CA dosage possess the maximum orientation and shrinkage ratio. According to Viogt–Kelvin model, the thermal shrinkage curves of the fibers can be well fitted using single exponential function. The three‐phase structure model of crystal phase–amorphous phase–CB phase was established to interpret the relationship among shrinkage, orientation, and dispersion of CB particles. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43846.
Dopamine‐Directed In‐Situ and One‐Step Synthesis of Au@Ag Core–Shell Nanoparticles Immobilized to a Metal–Organic Framework for Synergistic Catalysis
Authors: Huang Pengcheng , Ma Wenjie , Yu Ping , Mao Lanqun
Published: May 2016

We report a facile and general approach to the formation of bimetallic core–shell Au@Ag nanoparticles (NPs) immobilized to metal–organic frameworks (MOFs) via a one‐step synthetic route at room temperature. Dopamine (DA) is used as a moderate reductant, which can bind to negatively charged groups of MOFs through electrostatic interaction, and subsequently Au@Ag core–shell NPs are formed by in‐situ reduction of the bimetallic Au and Ag precursors step‐by‐step spontaneously without pre‐synthesized seeds. The as‐formed Au@Ag core–shell NPs immobilized to MOFs exhibit excellent catalytic activity for the reduction of 4‐nitrophenol (4‐NPh) by NaBH4 to 4‐aminophenol (4‐APh) due to a synergistic effect and are highly stable as demonstrated by recycling experiments.
Estimating freeway route travel time distributions with consideration to time‐of‐day, inclement weather, and traffic incidents
Authors: Caceres Hernan , Hwang Ha , He Qing
Published: May 2016

This paper develops an efficient probabilistic model for estimating route travel time variability, incorporating factors of time‐of‐day, inclement weather, and traffic incidents. Estimating the route travel time distribution from historical link travel time data is challenging owing to the interactions among upstream and downstream links. Upon creating conditional probability function for each link travel time, we applied Monte Carlo simulation to estimate the total travel time from origin to destination. A numerical example of three alternative routes in the City of Buffalo shows several implications. The study found that weather conditions, except for snow, incur minor impact on off‐peak and weekend travel time, whereas peak travel times suffer great variations under different weather conditions. On top of that, inclement weather exacerbates route travel time reliability, even when mean travel time increases moderately. The computation time of the proposed model is linearly correlated to the number of links in a route. Therefore, this model can be used to obtain all the origin to destination travel time distributions in an urban region. Further, this study also validates the well‐known near‐linear relation between the standard deviation of travel time per unit distance and the corresponding mean value under different weather conditions. Copyright © 2016 John Wiley & Sons, Ltd.
Multi‐level traffic control at large four‐leg roundabouts
Authors: Xu Hongfeng , Zhang Kun , Zhang Dong
Published: May 2016

Yield control and full signalization are typical traffic control solutions that can be used at large roundabouts. In the face of increasing congestion issues, it is preferred to use yield control during off‐peak periods and full signalization during peak periods. To automatically accommodate time‐varying vehicular demands, a multi‐level traffic control (MTC) is developed to implement hybrid yield control and fully actuated control at large four‐leg roundabouts. With new application of traffic control devices and traffic detection system, the right‐of‐way can be assigned to entering and circulating vehicles in three modes. The ‘all entering’ mode is equivalent to a yield control. The ‘no entering’ and ‘concurrent entering’ modes are equivalent to a fully actuated control. On the basis of time headways and occupancy times that are detected on the entry and circulatory roadways, the mode of right‐of‐way assignment can be changed in response to actual traffic conditions. For a specific mode of right‐of‐way assignment, traffic signal operation is managed by some detectable traffic events that are happening. The results of the simulation experiments conducted by VISSIM indicated that: (i) MTC was stabilized at the ‘all entering’ mode during off‐peak periods and at the ‘concurrent entering’ mode during peak periods; (ii) MTC would typically change the mode of right‐of‐way assignment according to actual traffic conditions as vehicular demands increased from off‐peak to peak or decreased from peak to off‐peak; and (iii) statistically speaking, MTC inherited the operational advantages of yield control and fully actuated control, and could be effective in improving the operational performance of large four‐leg roundabouts for all hours of the day, regardless of the level of left‐turn ratios. Copyright © 2016 John Wiley & Sons, Ltd.
Toxin structures as evolutionary tools: Using conserved 3D folds to study the evolution of rapidly evolving peptides
Authors: Undheim Eivind A. B. , Mobli Mehdi , King Glenn F.
Published: May 2016

Three‐dimensional (3D) structures have been used to explore the evolution of proteins for decades, yet they have rarely been utilized to study the molecular evolution of peptides. Here, we highlight areas in which 3D structures can be particularly useful for studying the molecular evolution of peptide toxins. Although we focus our discussion on animal toxins, including one of the most widespread disulfide‐rich peptide folds known, the inhibitor cystine knot, our conclusions should be widely applicable to studies of the evolution of disulfide‐constrained peptides. We show that conserved 3D folds can be used to identify evolutionary links and test hypotheses regarding the evolutionary origin of peptides with extremely low sequence identity; construct accurate multiple sequence alignments; and better understand the evolutionary forces that drive the molecular evolution of peptides.

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One‐pot synthesis of carbon dots using two different acids and their respective unique photoluminescence property
Authors: Loi Elaine , Ng Roy Wei Chao , Chang Melissa May Fung , Fong Jessica Fung Yee , Ng Yann Huey , Ng Sing Muk
Published: May 2016

Carbon dots, a new class of nanomaterial with unique optical property and have great potential in various applications. This work demonstrated the possibility of tuning the emission wavelength of carbon dots by simply changing the acid type used during synthesis. In particular, sulfuric and phosphoric acids and a mixture of the two were used to carbonize the same starting precursor, sucrose. This resulted in the isolation of carbon dots with blue (440 nm) and green (515 nm) emission. Interestingly, the use of an acid mixture at various ratios did not shift the initial emission profile, but did obviously alter the fluorescence efficiency of the peaks. This clearly showed that acid type can be used as an alternative tool to produce carbon dots that have different emissions using the same starting precursor. Copyright © 2016 John Wiley & Sons, Ltd.
Mono‐ and dichromatic LED illumination leads to enhanced growth and energy conversion for high‐efficiency cultivation of microalgae for application in space
Authors: Wagner Ines , Steinweg Christian , Posten Clemens
Published: May 2016

Illumination with red and blue photons is known to be efficient for cultivation of higher plants. For microalgae cultivation, illumination with specific wavelengths rather than full spectrum illumination can be an alternative where there is a lack of knowledge about achievable biomass yields. This study deals with the usage of color LED illumination to cultivate microalgae integrated into closed life support systems for outer space. The goal is to quantify biomass yields using color illumination (red, blue, green and mixtures) compared to white light. Chlamydomonas reinhardtii was cultivated in plate reactors with color compared to white illumination regarding PCE, specific pigment concentration and cell size. Highest PCE values were achieved under low PFDs with a red/blue illumination (680 nm/447 nm) at a 90 to 10% molar ratio. At higher PFDs saturation effects can be observed resulting from light absorption characteristics and the linear part of PI curve. Cell size and aggregation are also influenced by the applied light color. Red/blue color illumination is a promising option applicable for microalgae‐based modules of life support systems under low to saturating light intensities and double‐sided illumination. Results of higher PCE with addition of blue photons to red light indicate an influence of sensory pigments.
Stirred tank bioreactor culture combined with serum‐/xenogeneic‐free culture medium enables an efficient expansion of umbilical cord‐derived mesenchymal stem/stromal cells
Authors: Mizukami Amanda , Fernandes‐Platzgummer Ana , Carmelo Joana G. , Swiech Kamilla , Covas Dimas T. , Cabral Joaquim M. S. , da Silva Cláudia L.
Published: May 2016

Mesenchymal stem/stromal cells (MSC) are being widely explored as promising candidates for cell‐based therapies. Among the different human MSC origins exploited, umbilical cord represents an attractive and readily available source of MSC that involves a non‐invasive collection procedure. In order to achieve relevant cell numbers of human MSC for clinical applications, it is crucial to develop scalable culture systems that allow bioprocess control and monitoring, combined with the use of serum/xenogeneic (xeno)‐free culture media. In the present study, we firstly established a spinner flask culture system combining gelatin‐based Cultispher®S microcarriers and xeno‐free culture medium for the expansion of umbilical cord matrix (UCM)‐derived MSC. This system enabled the production of 2.4 (±1.1) x105 cells/mL (n = 4) after 5 days of culture, corresponding to a 5.3 (±1.6)‐fold increase in cell number. The established protocol was then implemented in a stirred‐tank bioreactor (800 mL working volume) (n = 3) yielding 115 million cells after 4 days. Upon expansion under stirred conditions, cells retained their differentiation ability and immunomodulatory potential. The development of a scalable microcarrier‐based stirred culture system, using xeno‐free culture medium that suits the intrinsic features of UCM‐derived MSC represents an important step towards a GMP compliant large‐scale production platform for these promising cell therapy candidates.
Outcomes following laparoscopic rectal cancer resection by supervised trainees
Authors: Currie A C , White I , Malietzis G , Moorghen M , Jenkins J T , Kennedy R H
Published: May 2016

Background

The aim was to evaluate the applicability of laparoscopic surgery in the treatment of primary rectal cancer in a training unit.

Methods

A cohort analysis was undertaken of consecutive patients undergoing elective surgery for primary rectal cancer over a 7-year interval. Data on patient and operative details, and short-term clinicopathological outcomes were collected prospectively and analysed on an intention-to-treat basis.

Results

A total of 306 patients (213 men, 69·6 per cent) of median (i.q.r.) age 67 (58–73) years with a median body mass index of 26·6 (23·9–29·9) kg/m2 underwent surgery. Median tumour height was 8 (6–11) cm from the anal verge, and 46 patients (15·0 per cent) received neoadjuvant radiotherapy. Seven patients (2·3 per cent) were considered unsuitable for laparoscopic surgery and underwent open resection; 299 patients (97·7 per cent) were suitable for laparoscopic surgery, but eight were randomized to open surgery as part of an ongoing trial. Some 291 patients (95·1 per cent) underwent a laparoscopic procedure, with conversion required in 29 (10·0 per cent). Surgery was partially or completely performed by trainees in 72·4 per cent of National Health Service patients (184 of 254), whereas private patients underwent surgery primarily by consultants. Median postoperative length of stay for all patients was 6 days and the positive circumferential resection margin rate was 4·9 per cent (15 of 306).

Conclusion

Supervised trainees can perform routine laparoscopic rectal cancer resection.
Detection of somatic BRCA1/2 mutations in ovarian cancer – next‐generation sequencing analysis of 100 cases
Authors: Koczkowska Magdalena , Zuk Monika , Gorczynski Adam , Ratajska Magdalena , Lewandowska Marzena , Biernat Wojciech , Limon Janusz , Wasag Bartosz
Published: May 2016

The overall prevalence of germline BRCA1/2 mutations is estimated between 11% and 15% of all ovarian cancers. Individuals with germline BRCA1/2 alterations treated with the PARP1 inhibitors (iPARP1) tend to respond better than patients with wild‐type BRCA1/2. Additionally, also somatic BRCA1/2 alterations induce the sensitivity to iPARP1. Therefore, the detection of both germline and somatic BRCA1/2 mutations is required for effective iPARP1 treatment. The aim of this study was to identify the frequency and spectrum of germline and somatic BRCA1/2 alterations in a group of Polish patients with ovarian serous carcinoma. In total, 100 formalin‐fixed paraffin‐embedded (FFPE) ovarian serous carcinoma tissues were enrolled to the study. Mutational analysis of BRCA1/2 genes was performed by using next‐generation sequencing. The presence of pathogenic variants was confirmed by Sanger sequencing. In addition, to confirm the germline or somatic status of the mutation, the nonneoplastic tissue was analyzed by bidirectional Sanger sequencing. In total, 27 (28% of patient samples) mutations (20 in BRCA1 and 7 in BRCA2) were identified. For 22 of 27 patients, nonneoplastic cells were available and sequencing revealed the somatic character of two BRCA1 (2/16; 12.5%) and two BRCA2 (2/6; 33%) mutations. Notably, we identified six novel frameshift or nonsense BRCA1/2 mutations. The heterogeneity of the detected mutations confirms the necessity of simultaneous analysis of BRCA1/2 genes in all patients diagnosed with serous ovarian carcinoma. Moreover, the use of tumor tissue for mutational analysis allowed the detection of both somatic and germline BRCA1/2 mutations.
Photoimmunotherapy of residual disease after incomplete surgical resection in head and neck cancer models
Authors: Moore Lindsay S. , de Boer Esther , Warram Jason M. , Tucker Matthew D. , Carroll William R. , Korb Melissa L. , Brandwein‐Gensler Margaret S. , van Dam Gooitzen M. , Rosenthal Eben L.
Published: May 2016

Antibody‐based photodynamic therapy, or photoimmunotherapy (PIT), is a novel, targeted cancer therapy, which can serve as both a diagnostic and a therapeutic agent. The primary objective of this study was to evaluate the capacity of panitumumab‐IRDye700DX (Pan‐IR700) to eliminate microscopic tumor remnants in the postsurgical setting, which was accomplished using novel in vitro and in vivo models of residual disease after incomplete resection. Additionally, PIT was evaluated in fresh human‐derived cancer tissue. To determine a threshold for cellular regrowth after PIT, an in vitro assay was performed using a range of cells representing microscopic disease quantities. Long‐term growth inhibition was induced after treatment of 5 × 103 and 1 × 104 cells at 6 J. A novel in vivo mouse model of subtotal tumor resection was used to assess the effectiveness of Pan‐IR700 mediated PIT to eliminate residual disease and inhibit recurrence in the post‐surgical wound bed. Mice receiving surgical treatment plus adjuvant PIT showed a threefold and fourfold reduction in tumor regrowth at 30 days post PIT in the 50% and 90% subtotal resection groups, respectively (as measured by bioluminescence imaging), demonstrating a significant (P < 0.001) reduction in tumor regrowth. To determine the translatability of epidermal growth factor receptor (EGFR)‐targeted PIT, SCCHN human tissues (n = 12) were treated with Pan‐IR700. A significant reduction (P < 0.001) in ATP levels was observed after treatment with Pan‐IR700 and 100 J cm−2 (48% ± 5%) and 150 J cm−2 (49% ± 7%) when compared to baseline. Targeting EGFR with Pan‐IR700 has robust potential to provide a tumor‐specific mechanism for eliminating residual disease in the surgical setting, thereby increasing therapeutic efficacy, prolonging progression‐free survival, and decreasing morbidity.
Design of a Continuous Tubular Cooling Crystallizer for Process Development on Lab‐Scale
Authors: Hohmann Lukas , Gorny Ramona , Klaas Oliver , Ahlert Jonas , Wohlgemuth Kerstin , Kockmann Norbert
Published: May 2016

Continuous manufacturing of fine chemical, life science, and pharmaceutical products is under recent investigation in R&D. As cooling crystallization is an important unit operation for purification of products, continuously operated, scalable devices are required for process development on lab‐scale. A tubular crystallizer was developed, based on the coiled flow inverter design. Experimental characterization proved a narrow residence time distribution of the liquid phase close to ideal plug flow. Counter‐current air cooling allows for adjusting linear and curved temperature profiles. Unseeded operation with the L‐alanine (water) system demonstrated that nucleation has to be actively controlled to successfully apply intensified continuous cooling crystallization processes.
Self‐Assembly of Uranyl–Peroxide Nanocapsules in Basic Peroxidic Environments
Authors: Miró Pere , Vlaisavljevich Bess , Gil Adria , Burns Peter C. , Nyman May , Bo Carles
Published: May 2016

A wide range of uranyl–peroxide nanocapsules have been synthesized using very simple reactants in basic media; however, little is known about the process to form these species. We have performed a density functional theory study of the speciation of the uranyl ions under different experimental conditions and explored the formation of dimeric species via a ligand exchange mechanism. We shed some light onto the importance of the excess of peroxide and alkali counterions as a thermodynamic driving force towards the formation of larger uranyl–peroxide species.
Mechanism of Macroscopic Motion of Oleate Helical Assemblies: Cooperative Deprotonation of Carboxyl Groups Triggered by Photoisomerization of Azobenzene Derivatives
Authors: Kageyama Yoshiyuki , Ikegami Tomonori , Kurokome Yuta , Takeda Sadamu
Published: May 2016

Macroscopic and spatially ordered motions of self‐assemblies composed of oleic acid and a small amount of an azobenzene derivative, induced by azobenzene photoisomerization, was previously reported. However, the mechanism of the generation of submillimeter‐scale motions by the nanosized structural transition of azobenzene was not clarified. Herein, an underlying mechanism of the motions is proposed in which deprotonation of carboxyl groups in cooperation with azobenzene photoisomerization causes a morphological transition of the self‐assembly, which in turn results in macroscopic forceful dynamics. The photoinduced deprotonation was investigated by potentiometric pH titration and FTIR spectroscopy. The concept of hierarchical molecular interaction generating macroscale function is expected to promote the next stage of supramolecular chemistry.
Eosin Y (EY) Photoredox‐Catalyzed Sulfonylation of Alkenes: Scope and Mechanism
Authors: Meyer Andreas Uwe , Straková Karolína , Slanina Tomáš , König Burkhard
Published: May 2016

Alkyl‐ and aryl vinyl sulfones were obtained by eosin Y (EY)‐mediated visible‐light photooxidation of sulfinate salts and the reaction of the resulting S‐centered radicals with alkenes. Optimized reaction conditions, the sulfinate and alkene scope, and X‐ray structural analyses of several reaction products are provided. A detailed spectroscopic study explains the reaction mechanism, which proceeds through the EY radical cation as key intermediate oxidizing the sulfinate salts.
ChemInform Abstract: Effect of Residual Water in Propylene Carbonate on Films Formed on Lithium.
Authors: NAZRI G. , MULLER R. H.
Published: May 2016

Es wird der Einfluß geringer H2O ‐Mengen (500 ppm ‐ 1%) in Propylencarbonatlö‐ sungen auf die Bildung von Oberflächenfilmen auf Li‐Elektroden mittels cyclischer Voltammetrie, IR‐Spektroskopie und ex situ‐ sowie in situ‐Röntgenbeugung untersucht.
ChemInform Abstract: Synthesis of Some New Fluorinated Heteroaryl Pyrazolines and Isooxazolines as Potential Biocidal Agents.
Authors: SACHCHAR S. P. , SINGH A. K.
Published: May 2016

Die kernfluorierten Chalkone (I) werden mit Phenylhydrazin zu den Pyrazolinen (II) oder mit Hydroxylamin zu den Isoxazolidinen (III) umgesetzt.
ChemInform Abstract: Isocimetidine and Analogues. Part 23. H2‐Antihistaminics.
Authors: BUSCHAUER A. , SCHUNACK W.
Published: May 2016

Auf dem im Formelschema angegebenen Weg werden ausgehend vom Methylimidazol (I) das Isocimetidin (VIII) sowie die analogen 4‐Pyrimidinone (X) hergestellt und auf H, ,H2 ‐antagonistische Aktivität untersucht.
ChemInform Abstract: Reaction Between [Ru3(CO)12] and the Tridentate Phosphine Ligand HC(PPh2)3.
Authors: CLUCAS J. A. , HARDING M. M. , NICHOLLS B. S. , SMITH A. K.
Published: May 2016

Aus der Titelreaktion in THF (50‐55°C, 24 h) werden die Komplexe (I)‐(VI) isoliert.
ChemInform Abstract: Chemical Vapor Deposition of Erosion‐Resistant TiB2 Coatings.
Authors: CAPUTO A. J. , LACKEY W. J. , WRIGHT I. G. , ANGELINI P.
Published: May 2016

Für eine Anzahl von Anwendungen, wie z.B. für Ventile oder Pumpenteile, werden Beschichtungen benötigt, die gegen eine Auswaschung unempfindlich sind.
ChemInform Abstract: AC Corrosion of Stainless Steel. Part 1. Breakdown of Passivity of SS304 in Neutral Aqueous Solutions.
Authors: WENDT J. L. , CHIN D.‐T.
Published: May 2016

Untersucht wird der Einfluß von Wechselstrom (60 Hz) auf die Korrosion von Typ 304‐Edelstahl in Na2SO4‐, NaNO3‐ und NaCl‐Lösungen, wozu die anodischen und kathodischen Polarisationskurven im Bereich von 0‐ 1000 mV Wechselspannung aufgenommen und die Probenoberflächen nach potentiostatischer Coulometrie mittels SEM untersucht werden.
ChemInform Abstract: Mössbauer and X‐Ray Diffraction Phase Analysis of Rusts from Atmospheric Test Sites with Different Environments in Sweden.
Authors: SINGH A. K. , ERICSSON T. , HAEGGSTROEM L. + , GULLMAN J.
Published: May 2016

An 8 verschiedenen Orten in Schwe′den wurden unlegierte Stahlplatten der atmosphärischen Korrosion ausgesetzt (1 bzw. 5 Jahre) und die gebildeten Rostschichten durch "Fe‐Mößbauer‐ Spektroskopie sowie durch Röntgen‐Beugung (Pulver) untersucht.
ChemInform Abstract: On the Preparation of Mercuric Peroxides and Refinement of the α‐HgO2 Structure.
Authors: PUSELJ M. , BAN Z. , LUKACEVIC E. , MORVAJ J.
Published: May 2016

α‐HgO2 wird nach einer literaturbekannten Methode durch Umsetzung von gelbem HgO mit 15proz. H2O2 bei 253 K (48 h) dargestellt, während β‐HgO2 auf den neuentwickelten Wegen A und Berhalten wird.
ChemInform Abstract: Aluminium Cyclohexaphosphate.
Authors: KANEPE Z. YA. , KONSTANT Z. A. , KRASNIKOV V. V.
Published: May 2016

Die Titelverbindung, A12P6O,8, die isostrukturell mit CrzPöOw ist, wird aus Al2O3 und NH4H4PO4 bei 550°C (4 h) dargestellt.
ChemInform Abstract: A Non‐stoichiometric Perovskite: BaInO2.5.
Authors: MADER K. , MUELLER‐BUSCHBAUM HK. +
Published: May 2016

Einkristalle des Titel‐Perowskits werden entweder durch direkte Synthese aus BaO und In2O3 (2:1) bei 1400°C (l4 d) oder durch Umsetzung von BaO; mit In bei 600°C, dann 1300°C (l0 d) dargestellt.
ChemInform Abstract: New Investigations About Oxo Uranates: On α‐Li2UO6. With a Remark About β‐Li2UO6.
Authors: WOLF R. , HOPPE R.
Published: May 2016

Zitronengelbe Einkristalle von a′Li6UO6 werden durch Tempern inniger Gemenge aus U308 und LizOz (Li:U = 7.2:l) im geschlossenen Au‐Rohr (910°C, 3 d; 800°C, 5 d; 660°C, 7 d) dargestellt.
ChemInform Abstract: Double Salts with the Chloride and the Bromide of Cobalt(II).
Authors: BALAREV KH. , DUKHLEV R.
Published: May 2016

Das System CoBr2/MgBr2/H2O wird bei 25 und 50°C untersucht.