bluuebunny/crossref_metadata_2025 huggingface dataset:
Particulate concentration and seasonal dynamics in the mesopelagic ocean based on the backscattering coefficient measured with Biogeochemical‐Argo floats
Authors: Poteau Antoine , Boss Emmanuel , Claustre Hervé
Published: June 2017

We explore a novel and spatially extensive data set obtained from Biogeochemical‐Argo (or BGC‐Argo) floats, containing 16,796 profiles of the particulate backscattering coefficient at 700 nm (bbp(700)) measured with three different sensors. We focus at the 900–950m depth interval (within the mesopelagic), where we found values to be relatively constant. While we find significant differences between estimates of bbp(700) obtained with different sensors (≈30% disagreement), the median values in most oceanic regions obtained with a single type of sensor are within 50% of each other and are consistent with measurements of suspended mass conducted in the early 1970s. Deviations from the quasi‐constant background value likely indicate times and locations associated with higher particulate export to depth. Indeed, we observe that in productive high‐latitude regions, a deep seasonal signal is observed, with enhanced values recorded a few months after surface spring/summer maximal concentrations. In addition, the deep bbp(700) is highest in regions exhibiting suboxic‐anoxic conditions (e.g., Northern Indian Ocean), which have been associated with local particulate production as well as reduced particle flux attenuation.
Predicting organic matter, nitrogen, and phosphorus concentrations in runoff from peat extraction sites using partial least squares regression
Authors: Tuukkanen T. , Marttila H. , Kløve B.
Published: June 2017

Organic matter and nutrient export from drained peatlands is affected by complex hydrological and biogeochemical interactions. Here partial least squares regression (PLSR) was used to relate various soil and catchment characteristics to variations in chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) concentrations in runoff. Peat core samples and water quality data were collected from 15 peat extraction sites in Finland. PLSR models constructed by cross‐validation and variable selection routines predicted 92, 88, and 95% of the variation in mean COD, TN, and TP concentration in runoff, respectively. The results showed that variations in COD were mainly related to net production (temperature and water‐extractable dissolved organic carbon (DOC)), hydrology (topographical relief), and solubility of dissolved organic matter (peat sulfur (S) and calcium (Ca) concentrations). Negative correlations for peat S and runoff COD indicated that acidity from oxidation of organic S stored in peat may be an important mechanism suppressing organic matter leaching. Moreover, runoff COD was associated with peat aluminum (Al), P, and sodium (Na) concentrations. Hydrological controls on TN and COD were similar (i.e., related to topography), whereas degree of humification, bulk density, and water‐extractable COD and Al provided additional explanations for TN concentration. Variations in runoff TP concentration were attributed to erosion of particulate P, as indicated by a positive correlation with suspended sediment concentration (SSC), and factors associated with metal‐humic complexation and P adsorption (peat Al, water‐extractable P, and water‐extractable iron (Fe)).
Effects of episodic rainfall on a subterranean estuary
Authors: Yu Xiayang , Xin Pei , Lu Chunhui , Robinson Clare , Li Ling , Barry D. A.
Published: June 2017

Numerical simulations were conducted to examine the effect of episodic rainfall on nearshore groundwater dynamics in a tidally influenced unconfined coastal aquifer, with a focus on both long‐term (yearly) and short‐term (daily) behavior of submarine groundwater discharge (SGD) and seawater intrusion (SWI). The results showed nonlinear interactions among the processes driven by rainfall, tides, and density gradients. Rainfall‐induced infiltration increased the yearly averaged fresh groundwater discharge to the ocean but reduced the extents of the saltwater wedge and upper saline plume as well as the total rate of seawater circulation through both zones. Overall, the net effect of the interactions led to an increase of the SGD. The nearshore groundwater responded to individual rainfall events in a delayed and cumulative fashion, as evident in the variations of daily averaged SGD and salt stored in the saltwater wedge (quantifying the extent of SWI). A generalized linear model (GLM) along with a Gamma distribution function was developed to describe the delayed and prolonged effect of rainfall events on short‐term groundwater behavior. This model validated with results of daily averaged SGD and SWI from the simulations of groundwater and solute transport using independent rainfall data sets, performed well in predicting the behavior of the nearshore groundwater system under the combined influence of episodic rainfall, tides, and density gradients. The findings and developed GLM form a basis for evaluating and predicting SGD, SWI, and associated mass fluxes from unconfined coastal aquifers under natural conditions, including episodic rainfall.
Fully‐Inkjet‐Printed Ag‐Coil/NiZn‐Ferrite for Flexible Wireless Power Transfer Module: Rigid Sintered Ceramic Body into Flexible Form
Authors: Bissannagari Murali , Lee Woosung , Lee Woong Yong , Jeong Jun Hwan , Kim Jihoon
Published: June 2017

Despite the material performances being superior to those of organic materials, inorganic materials are typically excluded for use in flexible and deformable electronic systems because of their rigid nature and the requirement for high processing temperature. This work presents a novel method of utilizing rigid NiZn‐ferrite films in a flexible platform and offers an opportunity to realize a flexible wireless power transfer (WPT) module. Inkjet printing is introduced in this study since it can coat NiZn‐ferrite films as well as pattern inductor coils for WPTs. A thermochemically inert buffer layer is selected based on a thermodynamic analysis and is introduced as a buffer layer for the NiZn‐ferrite to prevent chemical reaction between the ferrite film and the substrate and ensure that the ferrite film can be easily separated from the substrate during a high‐temperature sintering process. A Ag‐inductor coil is printed on the NiZn‐ferrite layer, and then the entire layer is embedded into polydimethylsiloxane, which renders the WPT module flexible. The flexibility of the WPT module is characterized by a bending test, and the structural and magnetic properties are also investigated. The performance of the flexible WPT module is demonstrated by transmitting wireless power to a light emitting diode.
Surface Plasmon Enhanced Nitrogen‐Doped Graphene Quantum Dot Emission by Single Bismuth Telluride Nanoplates
Authors: Saleem Umar , Permatasari Fitri A. , Iskandar Ferry , Ogi Takashi , Okuyama Kikuo , Darma Yudi , Zhao Meng , Loh Kian Ping , Rusydi Andrivo , Coquet Philippe , Birowosuto Muhammad Danang , Wang Hong
Published: June 2017

The light–matter interaction between nitrogen‐doped graphene quantum dots (N‐GQDs) and bismuth telluride (Bi2Te3) nanoplates is investigated. A maximum of (2.9 ± 0.3)‐fold emission rate enhancement is observed at room temperature due to the coupling of N‐GQD emission with the breathing mode of surface plasmon of single Bi2Te3 nanoplates. The enhancement varies with different emission wavelengths and nanoplate diameters in accordance with results obtained through the dipole radiation power in the electromagnetic simulations. From experiment, the quantum yield of N‐GQDs is obtained to be almost unity, while Bi2Te3 nanoplates may replace the conventional antenna. Such combination of novel active and plasmonic materials is promising for efficient lighting applications with multiple functionalities, especially tunable plasmonic metamaterial based on topological insulators.
Dehydrogenation kinetic model of heavy paraffins
Authors: Jiang Hongbo , Zhou Yilong , Zhou Liqun , Wang Yu , Cao Jing
Published: June 2017

Based on the dehydrogenation mechanism of heavy paraffins under industrial conditions, the intrinsic reaction kinetic model and catalyst deactivation model were established considering the influence of side reactions with different carbon‐number heavy paraffins. Based on the experimental data of dehydrogenation reactions with different carbon‐number paraffins in an axial continuous‐flow isothermal fixed‐bed microreactor, Powell optimization method was used to estimate the model parameters. The results show that there is a liner relationship between the activation energies and pre‐exponential factors of homologous reactions and carbon number of paraffins. A correlation model about the deactivation rate constants under different conditions was established. The validation of kinetic model showed that the model could be used to predict detailed product distribution with different feedstocks under different reaction conditions. © 2017 American Institute of Chemical Engineers AIChE J, 2017
von Hippel‐Lindau development in children and adolescents
Authors: Launbjerg Karoline , Bache Iben , Galanakis Michael , Bisgaard Marie Luise , Binderup Marie Louise M.
Published: June 2017

The autosomal dominant von Hippel‐Lindau disease (vHL) is associated with a lifelong risk of tumor development, especially retinal and CNS hemangioblastomas, pheochromocytoma, and renal cell carcinoma. Knowledge of paediatric vHL development is limited, and current surveillance guidelines are based on expert opinions. We aimed to describe the course of vHL development in children and adolescents, focusing on age at first manifestation, manifestation frequencies, and types. The prevalence of vHL diagnosis as well as manifestations in childhood were evaluated based on 99 patients, who had started surveillance before 18 years: 37 Danish patients from the national vHL research database and 62 international patients reported in 15 articles. Overall, 70% (69 of 99) developed manifestations before 18 years (median age at first manifestation: 12 years (range: 6–17 years)). Thirty per cent (30 of 99) had developed more than one manifestation type; the most frequent were retinal (34%) and CNS (30%) hemangioblastomas. Among the 37 Danish patients, 85% (97 of 116) of their tumors were asymptomatic. Vision outcome is significantly improved in hemangioblastomas that are treated while still asymptomatic. We agree with current guidelines that retinal surveillance be performed from birth. The patients had their first CNS hemangioblastomas at the median ages of 13–14 years (range: 6–17 years). Further, 11% (4 of 37) of the Danish patients had CNS surgery in their teenage years. Although the cohort is too small to make definite conclusions about specific initiation ages, regular CNS surveillance from vHL patients’ teenage years seems clinically relevant.
Push–Pull Distyryl Boron Dipyrromethenes as Near‐Infrared Sensitizers for Dye‐Sensitized Solar Cells
Authors: Shi Wen‐Jing , Kinoshita Takumi , Ng Dennis K. P.
Published: June 2017

A diiodo distyryl boron dipyrromethene (BODIPY) with an ethyl ester group at the meso position was prepared. This compound underwent palladium‐catalyzed Sonogashira cross‐coupling reactions with 4‐(diphenylamino)phenylethyne and 4‐(dimethylamino)phenylethyne to give the corresponding dialkynyl derivatives. After alkaline hydrolysis and acidic work‐up, all three compounds were converted to the carboxyl analogues, which could bind to the surface of TiO2 for application in dye‐sensitized solar cells (DSSCs). These compounds, in particular the dialkynyl analogues, possessed a push–pull structure and a highly conjugated π system, which shifted the Q band to the near‐infrared region. Electrochemical studies revealed that they had appropriate HOMO and LUMO levels for the construction of DSSCs comprising a TiO2 electrode and an electrolyte containing an I3−/I− redox couple. The optimized structures, frontier molecular orbitals, and absorption spectra of these sensitizers were calculated using density functional theory. The diiodo distyryl BODIPY‐based DSSC showed a photovoltaic conversion efficiency of 2.78 % under AM 1.5G standard sunlight and a maximum incident photon‐to‐current conversion efficiency (IPCE) of >45 % at 780 nm. The DSSCs fabricated with the dialkynyl distyryl BODIPYs could achieve an IPCE value of approximately 20 % at 840 nm and a broader photoresponse over the whole visible range extending up to approximately 950 nm in the near‐infrared region.
Bioorthogonal Labeling of Human Prostate Cancer Tissue Slice Cultures for Glycoproteomics
Authors: Spiciarich David R. , Nolley Rosalie , Maund Sophia L. , Purcell Sean C. , Herschel Jason , Iavarone Anthony T. , Peehl Donna M. , Bertozzi Carolyn R.
Published: June 2017

Sialylated glycans are found at elevated levels in many types of cancer and have been implicated in disease progression. However, the specific glycoproteins that contribute to the cancer cell‐surface sialylation are not well characterized, specifically in bona fide human disease tissue. Metabolic and bioorthogonal labeling methods have previously enabled the enrichment and identification of sialoglycoproteins from cultured cells and model organisms. Herein, we report the first application of this glycoproteomic platform to human tissues cultured ex vivo. Both normal and cancerous prostate tissues were sliced and cultured in the presence of the azide‐functionalized sialic acid biosynthetic precursor Ac4ManNAz. The compound was metabolized to the azidosialic acid and incorporated into cell surface and secreted sialoglycoproteins. Chemical biotinylation followed by enrichment and mass spectrometry led to the identification of glycoproteins that were found at elevated levels or uniquely in cancerous prostate tissue. This work therefore extends the use of bioorthogonal labeling strategies to problems of clinical relevance.
Structure of Amorphous Selenium by 2D 77Se NMR Spectroscopy: An End to the Dilemma of Chain versus Ring
Authors: Marple Maxwell , Badger Jackson , Hung Ivan , Gan Zhehong , Kovnir Kirill , Sen Sabyasachi
Published: June 2017

Amorphous selenium, owing to its tremendous technological importance and perhaps to its chemical simplicity, has been studied for nearly a century and yet an unequivocal structural description of this material remains lacking to date. The primary controversy regarding the structure of amorphous Se relates to the relative fraction of Se atoms residing in
chains versus in Se8 rings. Herein we present the results of a two‐dimensional solid‐state 77Se nuclear magnetic resonance (NMR) spectroscopic study of the chain and ring crystalline allotropes of Se as well as of amorphous Se to unequivocally demonstrate that 1) the Se8 rings and the
chains are characterized by their unique 77Se NMR signatures and 2) the structure of amorphous Se consists exclusively of
chains.
Integrated In Situ Characterization of a Molten Salt Catalyst Surface: Evidence of Sodium Peroxide and Hydroxyl Radical Formation
Authors: Takanabe Kazuhiro , Khan Abdulaziz M. , Tang Yu , Nguyen Luan , Ziani Ahmed , Jacobs Benjamin W. , Elbaz Ayman M. , Sarathy S. Mani , Tao Franklin (Feng)
Published: June 2017

Sodium‐based catalysts (such as Na2WO4) were proposed to selectively catalyze OH radical formation from H2O and O2 at high temperatures. This reaction may proceed on molten salt state surfaces owing to the lower melting point of the used Na salts compared to the reaction temperature. This study provides direct evidence of the molten salt state of Na2WO4, which can form OH radicals, using in situ techniques including X‐ray diffraction (XRD), scanning transmission electron microscopy (STEM), laser induced fluorescence (LIF) spectrometry, and ambient‐pressure X‐ray photoelectron spectroscopy (AP‐XPS). As a result, Na2O2 species, which were hypothesized to be responsible for the formation of OH radicals, have been identified on the outer surfaces at temperatures of ≥800 °C, and these species are useful for various gas‐phase hydrocarbon reactions, including the selective transformation of methane to ethane.
Material‐Efficient Microfluidic Platform for Exploratory Studies of Visible‐Light Photoredox Catalysis
Authors: Coley Connor W. , Abolhasani Milad , Lin Hongkun , Jensen Klavs F.
Published: June 2017

We present an automated microfluidic platform for in‐flow studies of visible‐light photoredox catalysis in liquid or gas–liquid reactions at the 15 μL scale. An oscillatory flow strategy enables a flexible residence time while preserving the mixing and heat transfer advantages of flow systems. The adjustable photon flux made possible with the platform is characterized using actinometry. Case studies of oxidative hydroxylation of phenylboronic acids and dimerization of thiophenol demonstrate the capabilities and advantages of the system. Reaction conditions identified through droplet screening translate directly to continuous synthesis with minor platform modifications.
Unique Spectral Overlap and Resonant Energy Transfer between Europium(II) and Ytterbium(III) Cations: No Quantum Cutting
Authors: Zhou Lei , Tanner Peter A. , Zhou Weijie , Ai Yeye , Ning Lixin , Wu Mingmei M. , Liang Hongbin
Published: June 2017

Samples of the Ca3Sc2Si3O12 (CSS) host singly doped with Eu2+ or Yb3+, doubly doped with Eu2+ and Yb3+, and triply doped with Ce3+, Eu2+ and Yb3+ were synthesized by a sol–gel combustion process under reducing conditions. Unlike previous reports of Eu2+→Yb3+ energy transfer in other systems, the energy transfer is resonant in the CSS host and the transfer efficiency reaches 100 % for lightly doped samples. The transfer mechanism is multipolar rather than electron transfer for the sample compositions employed herein. The emission intensity of Yb3+ is further enhanced by co‐doping with Ce3+ in addition to Eu2+. The quantum efficiencies of the doped materials range between 9 % and 93 %.
Mild Hydrogenation of Amides to Amines over a Platinum‐Vanadium Bimetallic Catalyst
Authors: Mitsudome Takato , Miyagawa Kazuya , Maeno Zen , Mizugaki Tomoo , Jitsukawa Koichiro , Yamasaki Jun , Kitagawa Yasutaka , Kaneda Kiyotomi
Published: June 2017

Hydrogenation of amides to amines is an important reaction, but the need for high temperatures and H2 pressures is a problem. Catalysts that are effective under mild reaction conditions, that is, lower than 30 bar H2 and 70 °C, have not yet been reported. Here, the mild hydrogenation of amides was achieved for the first time by using a Pt‐V bimetallic catalyst. Amide hydrogenation, at either 1 bar H2 at 70 °C or 5 bar H2 at room temperature was achieved using the bimetallic catalyst. The mild reaction conditions enable highly selective hydrogenation of various amides to the corresponding amines, while inhibiting arene hydrogenation. Catalyst characterization showed that the origin of the catalytic activity for the bimetallic catalyst is the oxophilic V‐decorated Pt nanoparticles, which are 2 nm in diameter.
Electrochemical Exfoliation of Layered Black Phosphorus into Phosphorene
Authors: Ambrosi Adriano , Sofer Zdeněk , Pumera Martin
Published: June 2017

Among 2D materials that recently have attracted enormous interest, black phosphorus (BP) is gaining a rising popularity due to its tunable band‐gap structure, which is strongly correlated to the thickness and can enable its use in optoelectronic and electronic applications. It is therefore important to provide a facile and scalable methodology to prepare single or few‐layer BP nanosheets. We propose herein a simple and fast top‐down method to exfoliate a BP crystal into nanosheets of reduced thickness by using electrochemistry. The application of an anodic potential to the crystal in an acidic aqueous solution allows control over the exfoliation efficiency and quality of the nanosheets produced. X‐ray photoelectron spectroscopy (XPS), Raman spectroscopy, and scanning transmission electron microscopy (STEM) have been applied to fully characterize the exfoliated material, which presented significantly reduced layer thickness compared to the starting bulk material.
Copper‐Catalyzed Three‐Component Carboazidation of Alkenes with Acetonitrile and Sodium Azide
Authors: Bunescu Ala , Ha Tu M. , Wang Qian , Zhu Jieping
Published: June 2017

A copper‐catalyzed three‐component reaction of alkenes, acetonitrile, and sodium azide afforded γ‐azido alkyl nitriles by formation of one C(sp3)−C(sp3) bond and one C(sp3)−N bond. The transformation allows concomitant introduction of two highly versatile groups (CN and N3) across the double bond. A sequence involving the copper‐mediated generation of a cyanomethyl radical and its subsequent addition to an alkene, and a C(sp3)−N bond formation accounted for the reaction outcome. The resulting γ‐azido alkyl nitrile can be easily converted into 1,4‐diamines, γ‐amino nitriles, γ‐azido esters, and γ‐lactams of significant synthetic value.
Highly flexible fabric strain sensor based on graphene nanoplatelet–polyaniline nanocomposites for human gesture recognition
Authors: Huang Ying , Gao Le , Zhao Yunong , Guo Xiaohui , Liu Caixia , Liu Ping
Published: June 2017

Flexible and wearable smart fabrics are becoming increasingly popular in healthcare and motion monitoring because of their potential applications in flexible and stretchable electronics. The integration of ordinary fabric with conductive fillers provides the fabric with new and intriguing functions, such as sensation. In this study, a low‐cost and efficient manner was used to fabricate a highly reliable conductive composite on fabric as an effective sensing material for gesture recognition. A strain sensor was fabricated by the incorporation of the highly conductive polyaniline (PANI) polymer, graphene nanoplatelets (GNPs), and a handful of silicon rubber (SR) onto elastic Lycra fabric via a spin‐coating method. We demonstrated that the fabric strain sensor was able to detect and monitor the bending angle of a human finger. By means of the covered structure of the PANI and GNPs, the composite fabric could bear a 40% maximum strain and possess the pleasant characteristic of stretching and bending. The gauge factor of the fabric strain sensor reached 67.3; this was an improvement of approximately four times compared to sensors without PANI microparticles. Finally, the superior performance of our strain sensor through the integration of five strain sensors on a glove for the motion detection of fingers was demonstrated. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2017,134, 45340.
Cellulose/polyaniline derivatives nanocomposites: Synthesis and their performance in removal of anionic dyes from simulated industrial effluents
Authors: Abbasian Mojtaba , Niroomand Pouneh , Jaymand Mehdi
Published: June 2017

A series of cellulose/polyaniline derivatives [polyaniline (PANI), poly(N‐methylaniline) (PNMANI), and poly(N‐ethylaniline) (PNEANI)] nanocomposites were synthesized by in situ chemical oxidation polymerization method and successfully applied for removal of acid red 4 and direct red 23 dyes from simulated industrial effluents. The synthesized nanocomposites were analyzed using Fourier transform infrared and ultraviolet‐visible spectroscopies, thermogravimetric analysis and scanning electron microscope. The effect of some parameters including pH, adsorbent amount, and initial dyes concentrations on adsorption processes were evaluated. The maximum adsorption capacities (Qm) for the synthesized nanocomposites were calculated, and among them the Cell/PANI sample showed the highest Qm for both AR4 (117 mg g–1) and DR23 (56 mg g–1) dyes. The regeneration and reusability tests exhibited that the synthesized nanocomposites had the relatively good reusability after five repetitions of the adsorption–desorption cycles. According to results, we envision that these nanocomposites, especially Cell/PANI, find application for removal of anionic dyes from industrial effluents mainly due to their low production costs, high adsorption effectiveness, and relatively good reusability. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45352.
Modification of absorbent poly(glycerol‐glutaric acid) films by the addition of monoglycerides
Authors: Boakye Prince G. , Jones Kerby C. , Latona Nicholas P. , Liu Cheng‐Kung , Besong Samuel A. , Lumor Stephen E. , Wyatt Victor T.
Published: June 2017

Monoglycerides (MGs) have been incorporated into the matrix of poly(glycerol‐co‐glutaric acid) films to investigate their effect on the thermal, mechanical, and solvent absorption properties of the resultant films. Solvent absorption studies revealed that poly(glycerol‐co‐glutaric acid‐co‐MG) films were able to absorb and resorb solvents better than poly(glycerol‐co‐glutaric acid) films, albeit they had higher erosion levels. Thermogravimetric analysis showed that the incorporated MGs did not affect the thermal stability of the glycerol‐based films. The MG‐incorporated films were observed to be much softer than the poly(glycerol‐co‐glycerol) films which was further proven by a 39‐fold reduction in Young's Modulus and 17‐fold reduction in fracture energy when compared to the poly(glycerol‐co‐glycerol). Mechanical property studies also revealed that the incorporation of MGs increased the elongation % and reduced the tensile strength of poly(glycerol‐co‐glutaric acid) films. Correlation analysis revealed a strong linear relationship between Young's Modulus and fracture energy (R2 = 0.9962), and between Young's Modulus and tensile strength (R2 = 0.9972). Our study proved that MGs can be successfully incorporated in the polymer matrix of poly(glycerol‐co‐glutaric acid) films to produce softer films with increased elongation and increased solvent absorption capacity. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45381.
Parametric optimization of intra‐ and inter‐layer strengths in parts produced by extrusion‐based additive manufacturing of poly(lactic acid)
Authors: Spoerk Martin , Arbeiter Florian , Cajner Hrvoje , Sapkota Janak , Holzer Clemens
Published: June 2017

Parts produced by extrusion‐based additive manufacturing experience the disadvantage of consisting of many weld‐lines, which consequently downgrade their mechanical properties. This work aims at maximizing the strength of printed parts by considering and improving the intra‐ and inter‐layer cohesion between adjacent strands. Therefore, printed poly(lactic acid) specimens were characterized by means of a particular tensile test setup, and the inter‐layer cohesion of printed specimens was evaluated by means of the double cantilever beam test. A detailed parametric statistical evaluation, which included printing temperatures, layer thicknesses, and layer‐designs, was complemented by the material's viscosity data and the analysis of the specimens' fracture surfaces and cross‐sections. An optimal layer‐design was found to be a key parameter in the optimization of strength with regard to different loading directions. Additionally, the maximization of the cohesion leads to a tremendous improvement in the mechanical performance of the printed parts, resulting in strengths of roughly 90% of those of compression‐molded parts. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45401.
Gamma radiation effect of polymethylvinylphenylsiloxane rubbers under different temperatures
Authors: Cao Ke , Ao Yinyong , Chen Jian , Peng Jing , Huang Wei , Li Jiuqiang , Zhai Maolin
Published: June 2017

The gamma radiation effect on polymethylvinylphenylsiloxane (PMVPS) rubbers is investigated by irradiation exposure of PMVPS rubbers to a maximum dose of 200 kGy in the temperature range 28–110 °C. Compared with unirradiated PMVPS rubber, the elongation at break of irradiated PMVPS rubber decreases while its elastic modulus increases with the increase of absorbed dose or radiation temperature. DSC, ATR‐FTIR, XPS, and 1H‐NMR indicate that slight degradation and oxidation reaction occur during the irradiation of PMVPS. Solvent swelling and gel fraction study confirms that the crosslinking density of PMVPS rubbers increases gradually with increasing absorbed dose or radiation temperature. Therefore, radiation‐induced crosslinking of PMVPS is dominant reactions for the chosen dose or temperature range. Furthermore, synergistic effect exists in the high‐temperature radiation process for PMVPS rubbers. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45404.
Solvent‐solubility‐parameter‐dependent homogeneity and sol–gel transitions of concentrated polyacrylonitrile solutions
Authors: Li Weijie , Hao Jian , Zhou Pucha , Liu Yaodong , Lu Chunxiang , Zhang Zhengfang
Published: June 2017

In this study, we systematically explored the dependence of the homogeneity and sol–gel transition temperatures of various polyacrylonitrile (PAN) solutions on the solvent solubility parameters. The Cole–Cole slope was used to characterize the solution homogeneity, and we found that the PAN/dimethyl sulfoxide (DMSO) solution, which had a smaller Hansen solubility parameter distance between the solvent and PAN, showed better solution homogeneity than the PAN/dimethylformamide and PAN/dimethylacetamide solutions. Additionally, we found that both heating and cooling were able to cause the gelation of the PAN solution, although their mechanisms were totally different. The gelation caused by heating was ascribed to the nitrile–nitrile coupling of PAN chains, whereas the gelation caused by cooling was due to the solvent bridge effect. In this case, DMSO, which had the highest polarity and the strongest interactions with nitrile groups, caused the highest gelation temperature of the PAN solution during cooling. The gelation temperature of the PAN solution exhibits dependence on its solvent polarity. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45405.
Functional assessment of plant and microalgal lipid pathway genes in yeast to enhance microbial industrial oil production
Authors: Peng Huadong , Moghaddam Lalehvash , Brinin Anthony , Williams Brett , Mundree Sagadevan , Haritos Victoria S.
Published: June 2017

As promising alternatives to fossil‐derived oils, microbial lipids are important as industrial feedstocks for biofuels and oleochemicals. Our broad aim is to increase lipid content in oleaginous yeast through expression of lipid accumulation genes and use Saccharomyces cerevisiae to functionally assess genes obtained from oil‐producing plants and microalgae. Lipid accumulation genes DGAT (diacylglycerol acyltransferase), PDAT (phospholipid: diacylglycerol acyltransferase), and ROD1 (phosphatidylcholine: diacylglycerol choline‐phosphotransferase) were separately expressed in yeast and lipid production measured by fluorescence, solvent extraction, thin layer chromatography, and gas chromatography (GC) of fatty acid methyl esters. Expression of DGAT1 from Arabidopsis thaliana effectively increased total fatty acids by 1.81‐fold above control, and ROD1 led to increased unsaturated fatty acid content of yeast lipid. The functional assessment approach enabled the fast selection of candidate genes for metabolic engineering of yeast for production of lipid feedstocks.
Transcriptional engineering of the glyceraldehyde‐3‐phosphate dehydrogenase promoter for improved heterologous protein production in Pichia pastoris
Authors: Ata Özge , Prielhofer Roland , Gasser Brigitte , Mattanovich Diethard , Çalık Pınar
Published: June 2017

The constitutive glyceraldehyde‐3‐phosphate dehydrogenase promoter (PGAP), which is one of the benchmark promoters of Pichia pastoris, was analyzed in terms of putative transcription factor binding sites. We constructed a synthetic library with distinct regulatory properties through deletion and duplication of these putative transcription factor binding sites and selected transcription factor (TF) genes were overexpressed or deleted to understand their roles on heterologous protein production. Using enhanced green fluorescent protein, an expression strength in a range between 0.35‐ and 3.10‐fold of the wild‐type PGAP was obtained. Another model protein, recombinant human growth hormone was produced under control of selected promoter variants and 1.6‐ to 2.4‐fold higher product titers were reached compared to wild‐type PGAP. In addition, a GAL4‐like TF was found to be a crucial factor for the regulation of PGAP, and its overexpression enhanced the heterologous protein production considerably (up to 2.2‐fold compared to the parental strain). The synthetic PGAP library generated enabled us to investigate the different putative transcription factors which are responsible for the regulation of PGAP under different growth conditions, ergo recombinant protein production under PGAP. Biotechnol. Bioeng. 2017;114: 2319–2327. © 2017 Wiley Periodicals, Inc.
In vivo synergistic activity of a CAZyme cassette from Acidothermus cellulolyticus significantly improves the cellulolytic activity of the C. bescii exoproteome
Authors: Kim Sun‐Ki , Chung Daehwan , Himmel Michael E. , Bomble Yannick J. , Westpheling Janet
Published: June 2017

The use of microbial cells to convert plant biomass directly to fuels and chemicals is referred to as consolidated bioprocessing (CBP). Members of the bacterial genus, Caldicellulosiruptor (Gram‐positive, anaerobic hyperthermophiles) are capable of deconstructing plant biomass without enzymatic or chemical pretreatment. This is accomplished by the production and secretion of free, multi‐domain enzymes that outperform commercial enzyme cocktails on some substrates. Here, we show that the exoproteome of Caldicellulosiruptor bescii may be enhanced by the heterologous expression of enzymes from Acidothermus cellulolyticus that act synergistically to improve sugar release from complex substrates; as well as improve cell growth. In this work, co‐expression of the A. cellulolyticus Acel_0615 β‐glucanase (GH6 and GH12) and E1 endoglucanase (GH5) enzymes resulted in an increase in the activity of the exoproteome on Avicel; as well as an increase in growth of C. bescii on Avicel compared to the parental strain or the strain expressing the β‐glucanase alone. Our ability to engineer the composition and effectiveness of the exoproteome of these bacteria provides insight into the natural mechanism of plant cell wall deconstruction, as well as future directions for improving CBP. Biotechnol. Bioeng. 2017;114: 2474–2480. © 2017 Wiley Periodicals, Inc.
Coke Slurries with Improved Higher Heating Value and Good Processability via Particle Shape Design
Authors: Jampolski Leon , Jakobs Tobias , Kolb Thomas , Willenbacher Norbert
Published: June 2017

Coke‐water slurries can be used as biogenic intermediates in conversion of residual biomass into high value fuels such as liquefied petroleum gas or synthetic natural gas. The effect of particle size and shape on the flow behavior of slurries including coke particles obtained from fast pyrolysis was investigated. Particles were shaped in a planetary ball mill and equivalent sphere diameter and circularity were used to characterize size and shape. An increased circularity resulted in a strong decrease in slurry viscosity. Accordingly, a higher mass fraction of particles can be mixed into the slurry, thus, increasing the higher heating value while still preserving good processing properties.
Ligand‐ and Solvent‐Tuned Chemoselective Carbonylation of Bromoaryl Triflates
Authors: Shen Chaoren , Wei Zhihong , Jiao Haijun , Wu Xiao‐Feng
Published: June 2017

The palladium‐catalyzed chemoselective carbonylation of bromoaryl triflates is reported. The selective C−Br bond versus C−OTf (OTf=triflate) bond functionalization can be remarkably tuned by the combination of the ligand [4,5‐bis(diphenylphosphino)‐9,9‐dimethylxanthene (Xantphos) vs. 1,1′‐bis(diphenylphosphino)ferrocene (DPPF)] and the solvent (toluene vs. DMSO). The respective ligand and solvent effects are rationalized by DFT calculations. In contrast, the monodentate ligands BuPAd2 and tBu3P prefer the selective C−Br bond activation and are solvent insensitive.
Photochromic Dopamine Receptor Ligands Based on Dithienylethenes and Fulgides
Authors: Lachmann Daniel , Studte Carolin , Männel Barbara , Hübner Harald , Gmeiner Peter , König Burkhard
Published: June 2017

We describe the incorporation of the well‐investigated class of photochromic dithienylethenes (DTEs) and fulgides into known dopamine receptor ligands such as 1,4‐disubstituted aromatic and hydroxybenzoxazinone piperazines as well as aminoindanes. Subtype and functional selective photochromic ligands were obtained and characterized by NMR and UV/VIS spectroscopic measurements. The photophysical properties of the DTE based dopamine ligands revealed a high fatigue resistance for the diarylmaleimides, but the ringclosure could not be accomplished in polar solvents due to a known twisted intramolecular charge transfer (TICT). Several cyclopentene‐DTEs showed high PSS, but a fast degradation by forming an irreversible byproduct. Focusing on the fulgides, high photostationary states and switching in polar solvents were possible. The compounds 43, 45 and 46 containing the isopropyl group showed only isomerization between the open E‐form and the closed C‐form. At a concentration of 1 nm, the cyclopentene‐DTE 29‐open showed a more than 11‐fold higher activation of D2S, a pharmacologically important G protein‐coupled receptor, than its photochromic congener 29‐closed. Interestingly, the fulgimide‐based pair 52‐(E)‐open/52‐closed could be discovered as an alternative photoswitch with inverse activation properties exhibiting four‐fold higher activity in the closed state.
Matched Molecular Pair Analysis on Large Melting Point Datasets: A Big Data Perspective
Authors: Withnall Michael , Chen Hongming , Tetko Igor V.
Published: June 2017

A matched molecular pair (MMP) analysis was used to examine the change in melting point (MP) between pairs of similar molecules in a set of ∼275k compounds. We found many cases in which the change in MP (ΔMP) of compounds correlates with changes in functional groups. In line with the results of a previous study, correlations between ΔMP and simple molecular descriptors, such as the number of hydrogen bond donors, were identified. In using a larger dataset, covering a wider chemical space and range of melting points, we observed that this method remains stable and scales well with larger datasets. This MMP‐based method could find use as a simple privacy‐preserving technique to analyze large proprietary databases and share findings between participating research groups.
Delays in breast cancer diagnosis after a state policy limiting Medicaid enrollment
Authors: Subramanian Sujha , Keating Nancy L.
Published: June 2017

In this issue of Cancer, Tarazi et al investigate the effects of a state policy that substantially limited Medicaid enrollment on the timeliness of breast cancer diagnosis. They observe a statistically significant increase of 3.3 percentage points in the percentage of women diagnosed with late‐stage disease after the policy change among women living in low‐income versus high‐income areas.

See also pages 3312‐9.
Distribution and female reproductive state differences in orexigenic and anorexigenic neurons in the brain of the mouth brooding African cichlid fish, Astatotilapia burtoni
Authors: Porter Danielle T. , Roberts David A. , Maruska Karen P.
Published: June 2017

Integration of reproduction and metabolism is necessary for species survival. While the neural circuits controlling energy homeostasis are well‐characterized, the signals controlling the relay of nutritional information to the reproductive axis are less understood. The cichlid fish Astatotilapia burtoni is ideal for studying the neural regulation of feeding and reproduction because females cycle between a feeding gravid state and a period of forced starvation while they brood developing young inside their mouths. To test the hypothesis that candidate neuropeptide‐containing neurons known to be involved in feeding and energy homeostasis in mammals show conserved distribution patterns, we performed immunohistochemistry and in situ hybridization to localize appetite‐stimulating (neuropeptide Y, NPY; agouti‐related protein, AGRP) and appetite‐inhibiting (cocaine and amphetamine‐regulated transcript, CART; pro‐opiomelanocortin, pomc1a) neurons in the brain. NPY, AGRP, CART, and pomc1a somata showed distribution patterns similar to other teleosts, which included localization to the lateral tuberal nucleus (NLT), the putative homolog of the mammalian arcuate nucleus. Gravid females also had larger NPY and AGRP neurons in the NLT compared to brooding females, but brooding females had larger pomc1a neurons compared to gravid females. Hypothalamic agrp mRNA levels were also higher in gravid compared to brooding females. Thus, larger appetite‐stimulating neurons (NPY, AGRP) likely promote feeding while females are gravid, while larger pomc1a neurons may act as a signal to inhibit food intake during mouth brooding. Collectively, our data suggest a potential role for NPY, AGRP, POMC, and CART in regulating energetic status in A. burtoni females during varying metabolic and reproductive demands.
Socializing problems and low self‐esteem enhance interpersonal models of eating disorders: Evidence from a clinical sample
Authors: Raykos Bronwyn C. , McEvoy Peter M. , Fursland Anthea
Published: June 2017

Objective

The present study evaluated the relative clinical validity of two interpersonal models of the maintenance of eating disorders, IPT‐ED (Rieger et al., ) and the interpersonal model of binge eating (Wilfley, MacKenzie, Welch, Ayres, & Weissman, ; Wilfley, Pike, & Striegel‐Moore, ). While both models propose an indirect relationship between interpersonal problems and eating disorder symptoms via negative affect, IPT‐ED specifies negative social evaluation as the key interpersonal problem, and places greater emphasis on the role of low self‐esteem as an intermediate variable between negative social evaluation and eating pathology.

Method

Treatment‐seeking individuals (N = 306) with a diagnosed eating disorder completed measures of socializing problems, generic interpersonal problems, self‐esteem, eating disorder symptoms, and negative affect (depression and anxiety). Structural equation models were run for both models.

Results

Consistent with IPT‐ED, a significant indirect pathway was found from socializing problems to eating disorder symptoms via low self‐esteem and anxiety symptoms. There was also a direct pathway from low self‐esteem to eating disorder symptoms. Using a socializing problems factor in the model resulted in a significantly better fit than a generic interpersonal problems factor. Inconsistent with both interpersonal models, the direct pathway from socializing problems to eating disorder symptoms was not supported.

Discussion

Interpersonal models that included self‐esteem and focused on socializing problems (rather than generic interpersonal problems) explained more variance in eating disorder symptoms. Future experimental, prospective, and treatment studies are required to strengthen the case that these pathways are causal.
Hidden roles of protected areas in the conservation of biodiversity and ecosystem services
Authors: Viña Andrés , Liu Jianguo
Published: June 2017

Many of the current protected areas worldwide are established for the conservation of particular species of interest, yet their benefits may go beyond these species since they could also contribute to the conservation of entire biodiversity pools. In addition, they may also contribute to the provision of ecosystem services. However, these benefits are seldom evaluated or targeted for improvement. Using field and remotely sensed data, we evaluated how representative of the plant biodiversity pool and of carbon sequestration is a network of nature reserves specifically established for the conservation of a target species, the giant panda (Ailuropoda melanoleuca), an icon of biodiversity conservation. Our results show that forest structure (including tree/bamboo species composition) within the nature reserve network is representative of the forest structure across the entire study region, with the exception of forests located at lower elevations which are not well represented. In addition, of the areas of forest cover gained across the study region between 2000 and 2010 (~10,700 km2) only about 15% occurred within panda reserves. Furthermore, accumulated net primary productivity (NPP) per year between 2000 and 2010 across the study region exhibited a monotonic increase, while the relative contribution of the reserve network to this accumulated NPP remained relatively constant (~25.5%). This suggests that the areas inside nature reserves may be reaching their maximum forest cover and NPP levels. Therefore, despite the significant positive roles of these reserves beyond the conservation of the species of interest, further conservation actions are needed to maintain and improve the conservation of regional biodiversity pools, as well as to improve gains in forest cover and in carbon sequestration. The procedures shown in this study are easily transferable to other study regions for assessing the benefits they provide beyond the conservation of the target(s) species of interest.
Hydroiodination‐Triggered Cascade Reaction with I2/PPh3/H2O: Metal‐Free Access to 3‐Substituted Phthalides from 2‐Alkynylbenzoates
Authors: Kawaguchi Shin‐ichi , Nakamura Kentaro , Yamaguchi Kotaro , Sato Yuki , Gonda Yuhei , Nishioka Masaaki , Sonoda Motohiro , Nomoto Akihiro , Ogawa Akiya
Published: June 2017

Phthalide is an important scaffold found in several biologically active compounds. Therefore, effective methods for the synthesis of phthalides are strongly desired. Herein, we describe the metal‐free synthesis of 3‐substituted phthalides by the reductive hydroiodination of 2‐alkynylbenzoates through an I2/PPh3/H2O‐triggered cascade reaction. A variety of 3‐substituted phthalides were synthesized in excellent yields by a one‐pot reaction involving four processes: desilylation, hydroiodination, cyclization, and reduction.
Pathogenic potential of antibodies to the GABAB receptor
Authors: Nibber Anjan , Mann Edward O. , Pettingill Philippa , Waters Patrick , Irani Sarosh R. , Kullmann Dimitri M. , Vincent Angela , Lang Bethan
Published: June 2017

GABAB receptor (GABABR) autoantibodies have been detected in the serum of immunotherapy‐responsive patients with autoimmune encephalitis. This study aimed to investigate the effect of immunoglobulin G (IgG) from a patient with GABABR antibodies on primary neuronal cultures and acute slices of entorhinal cortex. Primary hippocampal neuronal cultures were incubated with serum immunoglobulin from patients with GABABR or AMPA receptor (AMPAR) antibodies for up to 72 h to investigate their effect on receptor surface expression. Whole‐cell patch‐clamp recordings from layer III pyramidal cells of the medial entorhinal cortex were used to examine the effect on neuronal activity. GABABR surface expression was unaltered by incubation with GABABR antibodies. By contrast, after 24 h application of AMPAR antibodies, AMPARs were undetectable. However, acute application of GABABR IgG decreased both the duration of network UP states and the spike rate of pyramidal cells in the entorhinal cortex. GABABR antibodies do not appear to affect GABABRs by internalization but rather reduce excitability on the medial temporal lobe networks. This unusual mechanism of action may be exploited in rational drug development strategies.