bluuebunny/crossref_metadata_2025 huggingface dataset:
Different sources and degradation state of dissolved, particulate, and sedimentary organic matter along the Eurasian Arctic coastal margin
Authors: Karlsson Emma , Gelting Johan , Tesi Tommaso , van Dongen Bart , Andersson August , Semiletov Igor , Charkin Alexander , Dudarev Oleg , Gustafsson Örjan
Published: June 2016

Thawing Arctic permafrost causes massive fluvial and erosional releases of dissolved and particulate organic carbon (DOC and POC) to coastal waters. Here we investigate how different sources and degradation of remobilized terrestrial carbon may affect large‐scale carbon cycling, by comparing molecular and dual‐isotope composition of waterborne high molecular weight DOC (>1 kD, aka colloidal OC), POC, and sedimentary OC (SOC) across the East Siberian Arctic Shelves. Lignin phenol fingerprints demonstrate a longitudinal trend in relative contribution of terrestrial sources to coastal OC. Wax lipids and cutins were not detected in colloidal organic carbon (COC), in contrast to POC and SOC, suggesting that different terrestrial carbon pools partition into different aquatic carrier phases. The Δ14C signal suggests overwhelmingly contemporary sources for COC, while POC and SOC are dominated by old C from Ice Complex Deposit (ICD) permafrost. Monte Carlo source apportionment (δ13C, Δ14C) constrained that COC was dominated by terrestrial OC from topsoil permafrost (65%) and marine plankton (25%) with smaller contribution ICD and other older permafrost stocks (9%). This distribution is likely a result of inherent compositional matrix differences, possibly driven by organomineral associations. Modern OC found suspended in the surface water may be more exposed to degradation, in contrast to older OC that preferentially settles to the seafloor where it may be degraded on a longer timescale. The different sources which partition into DOC, POC, and SOC appear to have vastly different fates along the Eurasian Arctic coastal margin and may possibly respond on different timescales to climate change.
Evolution of the northern Argentine margin during the Cenozoic controlled by bottom current dynamics and gravitational processes
Authors: Gruetzner J. , Uenzelmann‐Neben G. , Franke D.
Published: June 2016

A detailed reflection seismic investigation on sediment deposition at the northern Argentine margin (37°S–42°S) resolves major modifications in oceanographic circulation during the Cenozoic, which resulted from variations in both climatic and tectonic processes. After an extensive erosional period following the onset of glaciation of Antartica at ∼34 Ma, which affected all water depth levels, a buried elongated mounded drift within the continental shelf was shaped by bottom current activity during the Miocene. This may represent the earliest deposits of the Malvinas Current that branches from the Antartic Circumpolar Current and today is part of a complex shallow water circulation system known as the Brazil‐Malvinas confluence. At the same time, a major terrace grew to its present form on the upper slope indicating that a precursor of Antarctic Intermediate Water was also part of the Brazil‐Malvinas confluence. After another major erosional phase inferred from a seismic unconformity at ∼6 Ma, sheeted drifts, mounded drifts, and sediment waves formed at the continental rise during the Pliocene/Pleistocene. These extensive contourite deposits are diagnostic for a steady north setting bottom flow at the depth level of today's Antarctic Bottom Water. Evidence for downslope transport mainly stems from the presence of buried turbidites and canyon‐related depocenters. These features can be related to Andean uplift during the Eocene and to the activation of the canyon system during the Pliocene.
Variation in relative dust impact charge recollection with antenna to spacecraft potential on STEREO
Authors: Thayer Frederick M. , Malaspina David M. , Collette Andrew , Sternovsky Zoltan
Published: June 2016

High‐velocity dust that impacts spacecraft releases charged plasma clouds that can create voltage perturbations that are measured by electric field instrumentation. These voltage perturbations are characterized by a relative maximum and minimum, which correspond to body and antenna charge recollection, respectively. The charge recollected by the antenna relative to the total recollected charge is found to correlate with the potential difference between the spacecraft and the antenna. From data analysis that spanned 2007–2013 on the STEREO‐A spacecraft, a positive correlation is found. This relationship will support future dust analysis with electric field instrumentation because it defines one spacecraft property that affects relative charge recollection.
Arctic Ocean stability: The effects of local cooling, oceanic heat transport, freshwater input, and sea ice melt with special emphasis on the Nansen Basin
Authors: Rudels Bert
Published: June 2016

The Arctic loses energy to space and heat is transported northward in the atmosphere and ocean. The largest transport occurs in the atmosphere. The oceanic heat flux is significantly smaller, and the warm water that enters the Arctic Ocean becomes covered by a low‐salinity surface layer, which reduces the heat transfer to the sea surface. This upper layer has two distinct regimes. In most of the deep basins it is due to the input of low‐salinity shelf water, ultimately conditioned by net precipitation and river runoff. The Nansen Basin is different. Here warm Atlantic water is initially in direct contact with and melts sea ice, its upper part being transformed into less dense surface water. The characteristics and depth of this layer are determined as functions of the temperature of the Atlantic water and for different energy losses using a one‐dimensional energy balance model. The amount of transformed Atlantic water is estimated for two different sea ice melt rates and the assumption of a buoyant boundary outflow. To create the upper layer sea ice formed elsewhere has to drift to the Nansen Basin. With reduced ice cover, this ice drift might weaken and the ice could disappear by the end of winter. The surface buoyancy input would disappear, and the upper layer might eventually convect back into the Atlantic water, reducing the formation of less dense Polar water. The created ice‐free areas would release more heat to the atmosphere and affect the atmospheric circulation.
Ground‐level observation of a terrestrial gamma ray flash initiated by a triggered lightning
Authors: Hare B. M. , Uman M. A. , Dwyer J. R. , Jordan D. M. , Biggerstaff M. I. , Caicedo J. A. , Carvalho F. L. , Wilkes R. A. , Kotovsky D. A. , Gamerota W. R. , Pilkey J. T. , Ngin T. K. , Moore R. C. , Rassoul H. K. , Cummer S. A. , Grove J. E. , Nag A. , Betten D. P. , Bozarth A.
Published: June 2016

We report on a terrestrial gamma ray flash (TGF) that occurred on 15 August 2014 coincident with an altitude‐triggered lightning at the International Center for Lightning Research and Testing (ICLRT) in North Central Florida. The TGF was observed by a ground‐level network of gamma ray, close electric field, distant magnetic field, Lightning Mapping Array (LMA), optical, and radar measurements. Simultaneous gamma ray and LMA data indicate that the upward positive leader of the triggered lightning flash induced relativistic runaway electron avalanches when the leader tip was at about 3.5 km altitude, resulting in the observed TGF. Channel luminosity and electric field data show that there was an initial continuous current (ICC) pulse in the lightning channel to ground during the time of the TGF. Modeling of the observed ICC pulse electric fields measured at close range (100–200 m) indicates that the ICC pulse current had both a slow and fast component (full widths at half maximum of 235 μs and 59 μs) and that the fast component was more or less coincident with the TGF, suggesting a physical association between the relativistic runaway electron avalanches and the ICC pulse observed at ground. Our ICC pulse model reproduces moderately well the measured close electric fields at the ICLRT as well as three independent magnetic field measurements made about 250 km away. Radar and LMA data suggest that there was negative charge near the region in which the TGF was initiated.
Surrogate gas prediction model as a proxy for Δ14C‐based measurements of fossil fuel CO2
Authors: Coakley Kevin J , Miller John B , Montzka Stephen A , Sweeney Colm , Miller Ben R
Published: June 2016

The measured14C:12C isotopic ratio of atmospheric CO2(and its associated derived Δ14C value) is an ideal tracer for determination of the fossil fuel derived CO2enhancement contributing to any atmospheric CO2measurement (Cff). Given enough such measurements, independent top‐down estimation of U.S. fossil fuel CO2emissions should be possible. However, the number of Δ14C measurements is presently constrained by cost, available sample volume, and availability of mass spectrometer measurement facilities. Δ14C is therefore measured in just a small fraction of samples obtained by flask air sampling networks around the world. Here we develop a projection pursuit regression (PPR) model to predictCffas a function of multiple surrogate gases acquired within the NOAA/Earth System Research Laboratory (ESRL) Global Greenhouse Gas Reference Network (GGGRN). The surrogates consist of measured enhancements of various anthropogenic trace gases, including CO, SF6, and halocarbon and hydrocarbon acquired in vertical airborne sampling profiles near Cape May, NJ and Portsmouth, NH from 2005 to 2010. Model performance for these sites is quantified based on predicted values corresponding to test data excluded from the model building process. Chi‐square hypothesis test analysis indicates that these predictions and corresponding observations are consistent given our uncertainty budget which accounts for random effects and one particular systematic effect. However, quantification of the combined uncertainty of the prediction due to all relevant systematic effects is difficult because of the limited range of the observations and their relatively high fractional uncertainties at the sampling sites considered here. To account for the possibility of additional systematic effects, we incorporate another component of uncertainty into our budget. Expanding the number of Δ14C measurements in the NOAA GGGRN and building new PPR models at additional sites would improve our understanding of uncertainties and potentially increase the number ofCffestimates by approximately a factor of 3. Provided that these estimates are of comparable quality to Δ14C‐based estimates, we expect an improved determination of fossil fuel CO2emissions.
Shifts in the community structure and activity of anaerobic ammonium oxidation bacteria along an estuarine salinity gradient
Authors: Zheng Yanling , Jiang Xiaofen , Hou Lijun , Liu Min , Lin Xianbiao , Gao Juan , Li Xiaofei , Yin Guoyu , Yu Chendi , Wang Rong
Published: June 2016

Anaerobic ammonium oxidation (anammox) is a major microbial pathway for nitrogen (N) removal in estuarine and coastal environments. However, understanding of anammox bacterial dynamics and associations with anammox activity remains scarce along estuarine salinity gradient. In this study, the diversity, abundance, and activity of anammox bacteria, and their potential contributions to total N2 production in the sediments along the salinity gradient (0.1–33.8) of the Yangtze estuarine and coastal zone, were studied using 16S rRNA gene clone library, quantitative polymerase chain reaction assay, and isotope‐tracing technique. Phylogenetic analysis showed a significant change in anammox bacterial community structure along the salinity gradient (P < 0.01), with the dominant genus shifting from Brocadia in the freshwater region to Scalindua in the open ocean. Anammox bacterial abundance ranged from 3.67 × 105 to 8.22 × 107 copies 16S rRNA gene g−1 and related significantly with salinity (P < 0.05). The anammox activity varied between 0.08 and 6.46 nmol N g−1 h−1 and related closely with anammox bacterial abundance (P < 0.01). Contributions of anammox activity to total N loss were highly variable along the salinity gradient, ranging from 5 to 77% and were significantly negatively correlated with salinity (P < 0.01). Sediment organic matter was also recognized as an important factor in controlling the relative role of anammox to total N2 production in the Yangtze estuarine and coastal zone. Overall, our data demonstrated a biogeographical distribution of anammox bacterial diversity, abundance, and activity along the estuarine salinity gradient and suggested that salinity is a major environmental control on anammox process in the estuarine and coastal ecosystems.
Evidence of atmospheric nanoparticle formation from emissions of marine microorganisms
Authors: Sellegri K. , Pey J. , Rose C. , Culot A. , DeWitt H. L. , Mas S. , Schwier A. N. , Temime‐Roussel B. , Charriere B. , Saiz‐Lopez A. , Mahajan A. S. , Parin D. , Kukui A. , Sempere R. , D'Anna B. , Marchand N.
Published: June 2016

Earth, as a whole, can be considered as a living organism emitting gases and particles into its atmosphere, in order to regulate its own temperature. In particular, oceans may respond to climate change by emitting particles that ultimately will influence cloud coverage. At the global scale, a large fraction of the aerosol number concentration is formed by nucleation of gas‐phase species, but this process has never been directly observed above oceans. Here we present, using semicontrolled seawater‐air enclosures, evidence that nucleation may occur from marine biological emissions in the atmosphere of the open ocean. We identify iodine‐containing species as major precursors for new particle clusters' formation, while questioning the role of the commonly accepted dimethyl sulfide oxidation products, in forming new particle clusters in the region investigated and within a time scale on the order of an hour. We further show that amines would sustain the new particle formation process by growing the new clusters to larger sizes. Our results suggest that iodine‐containing species and amines are correlated to different biological tracers. These observations, if generalized, would call for a substantial change of modeling approaches of the sea‐to‐air interactions.
Tide and skew surge independence: New insights for flood risk
Authors: Williams Joanne , Horsburgh Kevin J. , Williams Jane A. , Proctor Robert N. F.
Published: June 2016

Storm surges are a significant hazard to coastal communities around the world, putting lives at risk and costing billions of dollars in damage. Understanding how storm surges and high tides interact is crucial for estimating extreme water levels so that we can protect coastal communities. We demonstrate that in a tidal regime the best measure of a storm surge is the skew surge, the difference between the observed and predicted high water within a tidal cycle. Based on tide gauge records spanning decades from the UK, U.S., Netherlands, and Ireland we show that the magnitude of high water exerts no influence on the size of the most extreme skew surges. This is the first systematic proof that any storm surge can occur on any tide, which is essential for understanding worst‐case scenarios. The lack of surge generation dependency on water depth emphasizes the dominant natural variability of weather systems in an observation‐based analysis. Weak seasonal relationships between skew surges and high waters were identified at a minority of locations where long‐period changes to the tidal cycle interact with the storm season. Our results allow advances to be made in methods for estimating the joint probabilities of storm surges and tides.
Intercalibration of neutral density measurements for mapping the thermosphere
Authors: Weimer D. R. , Sutton E. K. , Mlynczak M. G. , Hunt L. A.
Published: June 2016

This paper describes a technique for mapping exospheric temperatures, derived from neutral density measurements from the Challenging Mini‐satellite Payload (CHAMP) and Gravity Recovery and Climate Experiment (GRACE) satellites. The Naval Reasearch Laboratory Mass Spectrometer, Incoherent Scatter Radar Extended Model (NRLMSISE‐00) thermosphere model is used for the conversion. Adjustments for each satellite were needed in order for the time‐averaged densities to agree with the model. It was necessary to correct for inexact modeling of the annual and semiannual oscillations in the density, as well as the declining densities during the solar minimum. It was found that a time‐varying perturbation in the atomic oxygen in the model could produce a good agreement at both altitudes. The time series of this oxygen variation was found to have a very high correlation with independent measurements of CO2 emissions measured with the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument. The temperature data are averaged on a spherical grid having equal areas in each pixel, avoiding functional fits that would blur finer details. The use of solar magnetic rather than geographic coordinates enhances the auroral ovals. There are strong elevations in the exospheric temperatures in the polar regions, particularly near the dayside cusp. Spatial filtering with spherical wavelets is used to remove statistical fluctuations, although some details are lost. The exospheric temperature maps are well ordered by the nitric oxide emission measurements from SABER. The technique that is described here could be applied to future improvements of empirical density models, having an accuracy and spatial resolution that is not presently available.
On the origins and timescales of geoeffective IMF
Authors: Lockwood Mike , Owens Mathew J. , Barnard Luke A. , Bentley Sarah , Scott Chris J. , Watt Clare E.
Published: June 2016

Southward interplanetary magnetic field (IMF) in the geocentric solar magnetospheric (GSM) reference frame is the key element that controls the level of space weather disturbance in Earth's magnetosphere, ionosphere, and thermosphere. We discuss the relation of this geoeffective IMF component to the IMF in the geocentric solar ecliptic (GSE) frame, and using the almost continuous interplanetary data for 1996–2015 (inclusive), we show that large geomagnetic storms are always associated with strong southward, out‐of‐ecliptic field in the GSE frame: Dipole tilt effects, which cause the difference between the southward field in the GSM and GSE frames, generally make only a minor contribution to these strongest storms. The time‐of‐day/time‐of‐year response patterns of geomagnetic indices and the optimum solar wind coupling function are both influenced by the timescale of the index response. We also study the occurrence spectrum of large out‐of‐ecliptic field and show that for 1 h averages it is, surprisingly, almost identical in ICMEs (interplanetary coronal mass ejections), around CIRs/SIRs (corotating and stream interaction regions) and in the “quiet” solar wind (which is shown to be consistent with the effect of weak SIRs). However, differences emerge when the timescale over which the field remains southward is considered: for longer averaging timescales the spectrum is broader inside ICMEs, showing that these events generate longer intervals of strongly southward average IMF and consequently stronger geomagnetic storms. The behavior of out‐of‐ecliptic field with timescale is shown to be very similar to that of deviations from the predicted Parker spiral orientation, suggesting the two share common origins.
The Cost of Not Being Out: Reflections on Efforts to Address LGBT Issues at a Large Southern Public University
Authors: Oliver Steven Thurston
Published: June 2016

Establishing a LGBT Center can be challenging, nowhere more so than at a large southern public university. Steven Thurston Oliver describes the process and what it taught him about the experiences of LGBT students, staff, and faculty… and himself.
Decarboxylative Coupling of α‐Keto Acids with ortho‐Phenylenediamines Promoted by an Electrochemical Method in Aqueous Media
Authors: Wang Hai‐Bin , Huang Jing‐Mei
Published: June 2016

An electrochemical method for the decarboxylative coupling of α‐keto acids with ortho‐phenylenediamines was developed. The reaction proceeded smoothly in aqueous solution under air and metal catalyst‐free conditions to afford 2‐substituted benzimidazoles in good yields. Benzothiazoles could also be synthesized by this protocol.

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The Application of N‐Protected 3‐Vinylindoles in Chiral Phosphoric Acid‐Catalyzed [3+2] Cyclization with 3‐Indolylmethanols: Monoactivation of the Catalyst to Vinyliminium
Authors: Fan Tao , Zhang Hong‐Hao , Li Can , Shen Yang , Shi Feng
Published: June 2016

A highly enantioselective [3+2] cyclization of 3‐vinylindoles with isatin‐derived 3‐indolylmethanols has been established in the presence of chiral phosphoric acid, which constructed the enantioenriched cyclopenta[b]indole scaffold linking a 3‐vinylindole moiety in generally good yields, considerable diastereoselectivities and high enantioselectivities (up to 93%, >95:5 dr, >99.5:0.5 er). More importantly, this reaction utilized N‐protected 3‐vinylindoles as competent reactants, which confronted the challenge in realizing a successful monoactivation mode of chiral phosphoric acid to vinyliminium in 3‐indolylmethanol‐involved enantioselective transformations. Besides, this protocol also settled the challenge in realizing a highly enantioselective [3+2] cyclization of 3‐vinylindoles with 3‐indolylmethanols, which would serve as a useful strategy for constructing an enantioenriched cyclopenta[b]indole scaffold linking a 3‐vinylindole moiety.

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Potassium tert‐Butoxide‐Promoted Synthesis of 1‐Aminoisoquinolines from 2‐Methylbenzonitriles and Benzonitriles under Catalyst‐Free Conditions
Authors: Feng Jian‐Bo , Wu Xiao‐Feng
Published: June 2016

Herein a practical and efficient protocol for preparing a range of aminoisoquinolines is reported. Various aminoisoquinolines were prepared in moderate to good yields from the corresponding 2‐methylbenzonitriles and benzonitriles upon treatment with potassium tert‐butoxide.

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Asymmetric Hydrogenation of 3‐Amido‐2‐arylpyridinium Salts by Triply Chloride‐Bridged Dinuclear Iridium Complexes Bearing Enantiopure Diphosphine Ligands: Synthesis of Neurokinin‐1 Receptor Antagonist Derivatives
Authors: Iimuro Atsuhiro , Higashida Kosuke , Kita Yusuke , Mashima Kazushi
Published: June 2016

We describe a most straightforward synthetic method for preparing neurokinin‐1 (NK1) receptor antagonist derivatives by asymmetric hydrogenation of 3‐amido‐2‐arylpyridinium salts using dinuclear iridium complexes with enantiopure diphosphine ligands, affording the corresponding chiral piperidines in high cis‐diastereoselectivity (>95:5) and moderately high enantioselectivity (up to 86%). Deprotection treatments afforded the NK‐1 receptor antagonist (+)‐CP‐99,994 (83% ee). In addition, we observed unique additive effects of 10‐camphorsulfonic acid in the asymmetric hydrogenation of 3‐amido‐2‐arylpyridinium salts.

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Photoinduced Intramolecular Haloarylation and Hydroarylation of Alkynes
Authors: Xu Dawen , Rios Ramon , Ba Feifei , Ma Dongmei , Gu Guangxin , Ding Aishun , Kuang Yunyan , Guo Hao
Published: June 2016

The cleavage of the aryl C−X bond under UV‐irradiation and its subsequent addition into an intramolecular alkyne moiety have been studied carefully. By simply regulating the addition of electron donor, highly chemoselective intramolecular hydroarylation and haloarylation reactions were achieved, providing efficient methods for the synthesis of 9‐benzylidene‐9H‐fluorene and 9‐(halo(phenyl)methylene)‐9H‐fluorene derivatives.
Radical Changes in Lewis Acid Catalysis: Matching Metal and Substrate
Authors: Bleith Tim , Deng Qing‐Hai , Wadepohl Hubert , Gade Lutz H.
Published: June 2016

Whereas the stereochemical rigidity of the coordination sphere of boxmi/CuII catalysts is key to achieving high enantioselectivity in the electrophilic alkylation of β‐ketoesters, this pathway is outperformed by a radical process for the corresponding catalytic transformation of oxindoles, giving rise to racemic products. For the corresponding ZnII catalysts, the selectivity in the latter process is outstanding despite the greater plasticity of the coordination shell. This reaction was thus developed into a highly useful synthetic method, which enabled the conversion of wide range of substrates with high yields and enantioselectivities.
Engineering Gram Selectivity of Mixed‐Charge Gold Nanoparticles by Tuning the Balance of Surface Charges
Authors: Pillai Pramod P. , Kowalczyk Bartlomiej , Kandere‐Grzybowska Kristiana , Borkowska Magdalena , Grzybowski Bartosz A.
Published: June 2016

Nanoparticles covered with ligand shells comprising both positively and negatively charged ligands exhibit Gram‐selective antibacterial action controlled by a single experimental parameter, namely the proportion of [+] and [−] ligands tethered onto these particles. Gram selectivity is attributed to the interplay between polyvalent electrostatic and non‐covalent interactions that work in unison to disrupt the bacterial cell wall. The [+/−] nanoparticles are effective in low doses, are non‐toxic to mammalian cells, and are tolerated well in mice. These results constitute the first example of rational engineering of Gram selectivity at the (macro)molecular level.
Rapid Synthesis of Cobalt Nitride Nanowires: Highly Efficient and Low‐Cost Catalysts for Oxygen Evolution
Authors: Zhang Yongqi , Ouyang Bo , Xu Jing , Jia Guichong , Chen Shi , Rawat Rajdeep Singh , Fan Hong Jin
Published: June 2016

Electrochemical splitting of water to produce hydrogen and oxygen is an important process for many energy storage and conversion devices. Developing efficient, durable, low‐cost, and earth‐abundant electrocatalysts for the oxygen evolution reaction (OER) is of great urgency. To achieve the rapid synthesis of transition‐metal nitride nanostructures and improve their electrocatalytic performance, a new strategy has been developed to convert cobalt oxide precursors into cobalt nitride nanowires through N2 radio frequency plasma treatment. This method requires significantly shorter reaction times (about 1 min) at room temperature compared to conventional high‐temperature NH3 annealing which requires a few hours. The plasma treatment significantly enhances the OER activity, as evidenced by a low overpotential of 290 mV to reach a current density of 10 mA cm−2, a small Tafel slope, and long‐term durability in an alkaline electrolyte.
Modeling of expandable polystyrene expansion
Authors: Hong Yifeng , Fang Xudong , Yao Donggang
Published: June 2016

A fundamental understanding of the expansion kinetics of expandable polystyrene (EPS) is crucial for the design and optimization of processes for EPS‐filled syntactic foams. In this study, a general formulation was developed to model EPS expansion. A semi‐analytical solution was obtained on the basis of the case of a single bubble expansion in an infinite matrix. The dimensionless bubble radius and pressure were defined and found to be exponential functions of the dimensionless expansion time. The characteristic bubble expansion time was able to characterize the timescale of the expansion process. The semi‐analytical solution could qualitatively predict the radial expansion of the EPS microsphere observed in a real‐time experiment. To obtain an accurate prediction, a numerical solution was obtained to the model that coupled the nucleation and expansion of multiple bubbles in a finite matrix at various temperatures. The results show that the numerical solution was able to quantitatively predict the radial expansion of EPS. A parameter sensitivity study was performed to examine the effect of each parameter over the expansion process. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43886.
Polylactic acid and its blends with petroleum‐based resins: Effects of reprocessing and recycling on properties
Authors: Yarahmadi Nazdaneh , Jakubowicz Ignacy , Enebro Jonas
Published: June 2016

Environmental and economic reasons make the use of bioplastics and biocomposites increasingly coveted in sectors other than packaging. Recycling of all wasted or rejected durable plastics is highly desired and biobased plastics are no exception. Therefore, the investigation of pre‐ and post‐consumer recycling of products made from biobased plastics is of great interest. Polylactic acid (PLA) and its blends have been chosen for this study because it is an excellent representative of mass‐produced bioplastics for industrial applications. As part of the “Sustainable Recycling of ‘Green’ Plastics” project, the current study addresses the durability issues related to the reprocessing and post‐consumer recycling of a PLA virgin resin and two commercially available blends of PLA namely one with polycarbonate (PC) and one with polyethylene (PE). The materials were investigated using methods that simulate post‐processing and post‐consumer recycling. Accelerated ageing was performed at elevated temperature and humidity to simulate the usage period of the materials. The materials were analyzed using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and their mechanical strength was evaluated by tensile and impact testing. The flow properties of the materials were characterized by the melt flow index (MFI). Multiple processing of pure PLA did not affect the impact strength or the glass transition temperature (Tg), but caused crystallization and increase in the MFI, indicating that degradation occurred during processing. DSC thermograms of the blends revealed that the components in the blends were not miscible. Multiple processing of the blends did not significantly affect the elastic modulus of the materials, but affected the elongation at break. The results indicated that multiple processing of the PLA/HDPE blend caused increased dispersion and thus increased elongation at break, while the dominating mechanism in the PLA/PC blend was degradation that caused a decrease in elongation at break. Post‐consumer recycling of the PLA/PC blend was simulated and the results clearly showed that ageing corresponding to one year of use caused a significant degradation of PLA. Pure PLA was severely degraded after only one ageing cycle. Although the PLA/PC blend showed some improved mechanical properties and resistance to degradation compared with pure PLA, one ageing cycle still caused a severe degradation of the PLA and even the PC was degraded as indicated by the formation of small amounts of bisphenol A. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43916.
Heterogeneous Uptake of Gas‐Phase Acetic Acid on the Surface of α‐Al2O3 Particles: Temperature Effects
Authors: Hou Siqi , Tong Shengrui , Zhang Ying , Tan Fang , Guo Yucong , Ge Maofa
Published: June 2016

Heterogeneous reactions are thought to play a significant role in the formation of haze, especially in wintertime, which suggests that temperature may affect the heterogeneous formation of organic aerosols. As the most‐abundant carboxylic acid in the Earth′s atmosphere, we chose acetic acid to study the effect of temperature on its heterogeneous reaction with α‐Al2O3 between 248 and 298 K. The products were characterized by in situ DRIFTS, which indicated that lowering the temperature slowed the formation of acetate, but promoted the formation of crystalline acetic acid. Moreover, low temperatures promoted a different reaction mechanism to that at room temperature. Owing to the formation of chain structures at low temperatures, crystalline acetic acid molecules covered the surface active sites on α‐Al2O3, thereby inhibiting the formation of acetate. However, crystalline acetic acid reacted with α‐Al2O3 itself in a sequential manner. Furthermore, the reactive uptake coefficients, active energies, and acetic acid lifetimes at different temperatures were investigated.
Fluorescently Sensing of DNA Triplex Assembly Using an Isoquinoline Alkaloid as Selector, Stabilizer, Inducer, and Switch‐On Emitter
Authors: Hu Yuehua , Lin Fan , Wu Tao , Wang Ying , Zhou Xiao‐Shun , Shao Yong
Published: June 2016

DNA triplex assembly has attracted a variety of interest in the regulation of genetic expression, drug screening, molecular switches, and sensors. However, these achievements are essentially dependent on the formation and stability of the triplex assembly. Herein, the recognition of DNA triplex assembly with various isoquinoline alkaloids was investigated. We found that natural chelerythrine (CHE) exhibits the highest selectivity in recognizing the triplex structure. The DNA triplex stability is substantially increased upon CHE binding, as opposed to the invariance in the stability of the duplex counterpart. CHE also favors the assembly of the triplex‐forming oligonucleotide (TFO) with its duplex counterpart. The triplex binding switches CHE to a strong fluorescent emitter, which suggests CHE as a useful probe in following triplex assembly. As a unique triplex selector, inducer, and emitter, CHE successfully reports the wide pH‐ and metal‐ion‐dependent tunability of the triplex nanoswitch in a label‐free manner.
Backfilling‐Free Strategy for Biopatterning on Intrinsically Dual‐Functionalized Poly[2‐Aminoethyl Methacrylate‐co‐Oligo(Ethylene Glycol) Methacrylate] Films
Authors: Lee Bong Soo , Lee Juno , Han Gyeongyeop , Ha EunRae , Choi Insung S. , Lee Jungkyu K.
Published: June 2016

We demonstrated protein and cellular patterning with a soft lithography technique using poly[2‐aminoethyl methacrylate‐co‐oligo(ethylene glycol) methacrylate] films on gold surfaces without employing a backfilling process. The backfilling process plays an important role in successfully generating biopatterns; however, it has potential disadvantages in several interesting research and technical applications. To overcome the issue, a copolymer system having highly reactive functional groups and bioinert properties was introduced through a surface‐initiated controlled radical polymerization with 2‐aminoethyl methacrylate hydrochloride (AMA) and oligo(ethylene glycol) methacrylate (OEGMA). The prepared poly(AMA‐co‐OEGMA) film was fully characterized, and among the films having different thicknesses, the 35 nm‐thick biotinylated, poly(AMA‐co‐OEGMA) film exhibited an optimum performance, such as the lowest nonspecific adsorption and the highest specific binding capability toward proteins.
Prognosis following surgical bypass compared with laparotomy alone in unresectable pancreatic adenocarcinoma
Authors: Insulander J , Sanjeevi S , Haghighi M , Ivanics T , Analatos A , Lundell L , Del Chiaro M , Andrén-Sandberg Å , Ansorge C
Published: June 2016

Background

Resection with curative intent has been shown to prolong survival of patients with locoregional pancreatic ductal adenocarcinoma (PDAC). However, up to 33 per cent of patients are deemed unresectable at exploratory laparotomy owing to unanticipated locally advanced or metastatic disease. In these patients, prophylactic double bypass (PDB) procedures have been considered the standard of care. The aim of this study was to compare PDB with exploratory laparotomy alone in terms of impact on postoperative course, chemotherapy and overall survival.

Methods

This retrospective observational cohort study (2004–2013) was conducted using a prospective institutional database. Patients with histologically confirmed, unresectable PDAC were included. Relationships between PDB procedures, exploratory laparotomy alone, postoperative chemotherapy and best supportive care were investigated by means of Cox regression. Overall survival was compared using Kaplan–Meier estimations and log rank test.

Results

Of 503 patients with PDAC scheduled for resection with curative intent, 104 were deemed unresectable at laparotomy (resection rate 79·3 per cent). Seventy-four patients underwent PDB procedures and 30 had exploratory laparotomy alone. PDB and exploratory laparotomy were similar in terms of perioperative mortality, initiation of chemotherapy and overall survival. Compared with best supportive care, postoperative chemotherapy prolonged survival (8·0 versus 14·4 months in locally advanced PDAC, P = 0·007; 2·3 versus 8·0 months in metastatic PDAC, P < 0·001). Patients undergoing chemotherapy following exploratory laparotomy alone had longer median overall survival than patients undergoing chemotherapy following PDB procedures (16·3 versus 10·3 months; P = 0·040).

Conclusion

Patients with pancreatic cancer deemed unresectable at laparotomy may derive survival benefit from subsequent chemotherapy as opposed to supportive care alone. At laparotomy, proceeding with a bypass procedure for prophylactic symptom control may be prognostically unfavourable.
Biomembranes from slaughterhouse blood erythrocytes as prolonged release systems for dexamethasone sodium phosphate
Authors: Drvenica Ivana T. , Bukara Katarina M. , Ilić Vesna Lj. , Mišić Danijela M. , Vasić Borislav Z. , Gajić Radoš B. , Đorđević Verica B. , Veljović Đorđe N. , Belić Aleksandar , Bugarski Branko M.
Published: June 2016

The present study investigated preparation of bovine and porcine erythrocyte membranes from slaughterhouse blood as bio‐derived materials for delivery of dexamethasone‐sodium phosphate (DexP). The obtained biomembranes, i.e., ghosts were characterized in vitro in terms of morphological properties, loading parameters, and release behavior. For the last two, an UHPLC/–HESI–MS/MS based analytical procedure for absolute drug identification and quantification was developed. The results revealed that loading of DexP into both type of ghosts was directly proportional to the increase of drug concentration in the incubation medium, while incubation at 37°C had statistically significant effect on loaded amount of DexP (P < 0.05). The encapsulation efficiency was about fivefold higher in porcine compared to bovine ghosts. Insight into ghosts’ surface morphology by field emission‐scanning electron microscopy and atomic force microscopy confirmed that besides inevitable effects of osmosis, DexP inclusion itself had no observable additional effect on the morphology of the ghosts carriers. DexP release profiles were dependent on erythrocyte ghost type and amount of residual hemoglobin. However, sustained DexP release was achieved and shown over 3 days from porcine ghosts and 5 days from bovine erythrocyte ghosts. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1046–1055, 2016
Suppression of α‐Amylase inactivation in the presence of ethanol: Application of a two‐step model
Authors: Calabrese Vincent T. , Minns Jason W. , Khan Arshad
Published: June 2016

A number of years ago we reported a two‐step inactivation mechanism for α‐amylase (enzyme) on the basis of theoretical and experimental studies in aqueous solutions. In the first step the metal (Ca2+) ion dissociates reversibly from the enzyme followed by an irreversible thermal inactivation of the apoenzyme. In this study we report inactivation of the enzyme in the presence of ethanol–water solutions. We noticed that as the concentration of ethanol in the aqueous solution is increased, the thermal inactivation of the enzyme is suppressed with almost no inactivation (in 1 h, 30°C) when 50% alcohol is present in the solution. These results are explained by the two‐step inactivation model. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1271–1275, 2016
An extractive membrane biofilm reactor as alternative technology for the treatment of methyl tert‐butyl ether contaminated water
Authors: Guisado I. M. , Purswani J. , González‐López J. , Pozo C.
Published: June 2016

Among the strategies developed for contaminated groundwater bioremediation, those based on the use of bacteria adhering to inert supports and establishing biofilms have gained great importance in this field. Extractive membrane biofilm reactor (EMBFR) technology offers productive solutions for the removal of volatile and semi‐volatile compounds. EMBFR technology is based on the use of extractive semipermeable membranes through which contaminants migrate to the biological compartment in which microorganisms with pollutant biotransformation and/or mineralization capacities can grow, forming an active biofilm on the membrane surface. The objective of this study was to assess the use of three bacterial strains (Paenibacillus sp. SH7 CECT 8558, Agrobacterium sp. MS2 CECT 8557, and Rhodococcus ruber EE6 CECT 8612), as inoculum in a lab‐scale EMBFR running for 28 days under aerobic conditions to eliminate methyl tert‐butyl ether (MTBE) from water samples. Three different hydraulic retention times (1, 6, and 12 h) were employed. MTBE degradation values were determined daily by a gas GC‐MS technique, as well as suspended bacterial growth. The biofilm established by the bacterial strains on the semipermeable membrane was detected by Field‐Emission Scanning Electron Microscopy (FESEM) at the end of each experiment. The acute toxicity of the treated effluents and biomedium was determined by Microtox© assay (EC50).The results achieved from the MTBE degradation, biofilm formation, and toxicity analysis indicated that bacterial strains MS2 and EE6 were the best options as selective inoculum, although further research is needed, particularly with regard to their possible use as a mixed culture. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1238–1245, 2016
Development of a web interface for performing morphological operations on CUDA platform
Authors: Kuşcu Ömer , Çetiner Halit , Çetin Özdemir
Published: June 2016

In order to make use of the performance advantages offered by modern graphics processing units (GPUs), certain image‐processing methods are used on GPU platforms. This study presents a web‐based interface, named cuDO‐Lab, whose capabilities include morphological operations. Different from other similar studies, using this interface, experimental studies can be done on both CPU and GPU platforms. NVIDIA®'s Compute Unified Device Architecture (CUDA®) platform was employed to perform GPU operations. Thanks to cuDO‐Lab, students can perform basic morphological operations without paying for licenses or requiring hardware such as CUDA® enabled GPU and software or driver installations. The cuDO‐Lab also offers a responsive web‐user interface, so the laboratory can be accessed from many devices, such as phones, tablets, laptops, and personal computers, with any screen resolution. This offers time savings, ease of use, and access from anywhere. © 2016 Wiley Periodicals, Inc. Comput Appl Eng Educ 24:787–798, 2016; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21751
Prognostic value of health‐related quality of life for death risk stratification in patients with unresectable glioblastoma
Authors: Paquette Brice , Vernerey Dewi , Chauffert Bruno , Dabakuyo Sandrine , Feuvret Loic , Taillandier Luc , Frappaz Didier , Taillia Hervé , Schott Roland , Ducray François , Fabbro Michel , Tennevet Isabelle , Ghiringhelli François , Guillamo Jean‐Sébastien , Durando Xavier , Castera Daniel , Frenay Marc , Campello Chantal , Dalban Cécile , Skrzypski Jérome , Chinot Olivier , Anota Amélie , Bonnetain Franck
Published: June 2016

Glioblastoma is the most common malignant brain tumor in adults. Baseline health‐related quality of life (HRQoL) is a major subject of concern for these patients. We aimed to assess the independent prognostic value of HRQoL in unresectable glioblastoma (UGB) patients for death risk stratification. One hundred and thirty‐four patients with UGB were enrolled from the TEMAVIR trial. HRQoL was evaluated at baseline using the EORTC QLQ‐C30 and BN20 brain cancer module. Clinical and HRQoL parameters were evaluated in univariable and multivariable Cox analysis as prognostic factors for overall survival (OS). Performance assessment and internal validation of the final model were evaluated with Harrel's C‐index, calibration plot, and bootstrap sample procedure. Two OS independent predictors were identified: future uncertainty and sensitivity deficit. The final model exhibited good calibration and acceptable discrimination (C statistic = 0.63). The internal validity of the model was verified with robust uncertainties around the hazard ratio. The prognostic score identified three groups of patients with distinctly different risk profiles with median OS estimated at 16.2, 9.2, and 4.5 months. We demonstrated the additional prognostic value of HRQoL in UGB for death risk stratification and provided a score that may help to guide clinical management and stratification in future clinical trials.
Brand placement disclosure effects on persuasion: The moderating role of consumer self‐control
Authors: Janssen Loes , Fransen Marieke L. , Wulff Rebecca , van Reijmersdal Eva A.
Published: June 2016

The inclusion of branded products in media entertainment has become a popular marketing strategy, because viewers are less likely to recognize the persuasive intent of sponsored content as compared with traditional advertising. To guarantee fair communication and protect consumers against unobtrusive persuasion attempts, European media policy has obligated broadcasters to disclose the presence of brand placement in their television shows. Recent studies demonstrate that disclosures raise viewers' persuasion knowledge; however, the circumstances under which brand placement disclosures may affect brand evaluations and resistance to the persuasive impact of brand placement are still unclear. In two experiments, we uncovered self‐control depletion as an important moderator of disclosure effects on brand evaluations and resistance to brand placement influence. Whereas disclosures increase resistance and decrease persuasion for viewers not depleted of their self‐control, disclosures do not affect resistance and even result in more favorable brand evaluations when viewers' self‐control is depleted by a previous self‐control task. Because a state of self‐control depletion can be perceived as the “couch‐potato” mindset in which people expose themselves to entertaining television content, our findings imply that instead of protecting consumers from hidden persuasion, disclosures may unintentionally increase the persuasive effects of brand placement. We discuss several possible mechanisms that could explain our findings. Copyright © 2016 John Wiley & Sons, Ltd.
Study of the Vapor Phase Over Fusarium Fungi Cultured on Various Substrates
Authors: Savelieva Elena I. , Gustyleva Liudmila K. , Kessenikh Elizaveta D. , Khlebnikova Natalya S. , Leffingwell John , Gavrilova Olga P. , Gagkaeva Tatiana Yu.
Published: June 2016

The compositions of volatile organic compounds (VOCs) emitted by Fusarium fungi (F. langsethiae, F. sibiricum, F. poae, and F. sporotrichioides) grown on two nutritive substrates: potato sucrose agar (PSA) and autoclaved wheat kernels (WK) were investigated. The culturing of fungi and study of their VOC emissions were performed in chromatographic vials at room temperature (23 – 24 °C) and the VOCs were sampled by a solid‐phase microextraction on a 85 μm carboxen/polydimethylsiloxane fiber. GC/MS was performed using a 60‐m HP‐5 capillary column. Components of the VOC mixture were identified by electron impact mass spectra and chromatographic retention indices (RIs). The most abundant components of the VOC mixture emitted by Fusarium fungi are EtOH, AcOH, iBuOH, 3‐methylbutan‐1‐ol, 2‐methylbutan‐1‐ol, ethyl 3‐methylbutanoate, terpenes with M 136, sesquiterpenes with M 204 (a total of about 25), and trichodiene. It was found that the strains grown on PSA emit a wider spectrum and larger amount of VOCs compared with those grown on wheat kernels. F. langsethiae strain is the most active VOC producer on both substrates. The use of SPME and GC/MS also offers the potential for differentiation of fungal species and strains.