bluuebunny/crossref_metadata_2025 huggingface dataset:
Spontaneous formation of silica–polymer composite particles by simple co-precipitation process
Authors: Yabu Hiroshi , Satoh Hiroki , Kanahara Masaaki , Saito Yuta , Shimomura Masatsugu
Published: March 2014

Organic–inorganic composite microparticle having interior nanostructures is one of the promising materials for creating a novel class of functional materials. In this paper, we show a simple co-precipitation method for silica nanoparticles and polymer composite particles by mixing water with water dispersed silica nanoparticles into tetrahydrofran THF solution of amino-terminated poly(butadiene) (PB) and evaporation of THF. High loading of inorganic nanoparticles into polymer particles was achieved and this high loading of inorganic nanoparticles was also an advantage for creating highly porous polymer particles by removal of inorganic part with HF. Interior structures of composite particles can be controlled by phase-separation of polymers.
Multi layer precursor method for Cu(In,Ga)Se2 solar cells fabricated on flexible substrates
Authors: Chantana Jakapan , Watanabe Taichi , Teraji Seiki , Kawamura Kazunori , Minemoto Takashi
Published: March 2014

Cu(In,Ga)Se2 (CIGS) solar cells are deemed one of the highest conversion efficiency thin-film solar cells, and the utilization of flexible (stainless steel; SUS) substrates offers several advantages in terms of lowering manufacturing costs. In this work, CIGS films on SUS substrates are deposited by the so-called “multi layer precursor method” using multi layer co-evaporation of material sources. The examination concentrates on the influence of growth temperature and Ga/III, Ga/(In + Ga), profiles of CIGS layers on the cell performance. According to the results, CIGS crystallization is primarily manipulated by growth temperature. Ultimately, the deposition of CIGS on a flexible SUS substrate can be readily controlled to obtain a suitable double Ga/III-grading profile with large grains of CIGS for a high cell efficiency of 16.05%.
A survey of quiet auroral arc orientation and the effects of the interplanetary magnetic field
Authors: Gillies D. M. , Knudsen D. J. , Donovan E. F. , Spanswick E. L. , Hansen C. , Keating D. , Erion S.
Published: March 2014

Using data from the THEMIS All‐Sky Imager array, we have carried out an extensive study of the orientation of quiet auroral arcs relative to the magnetic east‐west direction. We used over 7500 images of quiet auroral arcs that were collected during extended solar minimum and at various geomagnetic latitudes and longitudes. For each arc, we determined its “tilt” (the angle the arc makes with the local magnetic east‐west direction) and its “multiplicity” (whether or not the arc was part of a multiple‐arc system). We have found that at more equatorward latitudes, arc tilts are within σSD = ±7.7∘. We determined that both single‐ and multiple‐arc systems tend to tilt a few degrees to the south‐east prior to 23 magnetic local time (MLT) and to the north‐east afterward. This tilt appears to be more prominent at higher latitudes. We compared the auroral arc orientations to the mapping of equatorial contours of constant magnetic field strength into the ionosphere, where we used the T87 and T89 magnetic field models for quiet (Kp = 1,3) conditions for the mappings and to determine the constant equatorial magnetic field strength contours. We found that the MLT trends of the tilts are such that arc alignment appears to follow the constant magnetic field strength contours as projected into the ionosphere. We assert that the systematic dependencies of the orientation of auroral arcs indicate that arc morphology is governed by the large‐scale structure of the magnetosphere as opposed to localized processes within the ionosphere. In addition, we studied the effects of the interplanetary magnetic field (IMF) on the location in MLT of the reversal of the arc tilts. We found that negative IMF Bxand Byconditions cause the reversal location to shift duskward of 23 MLT. Alternately, a positive IMF Bx, coupled with a negative By, results in a shift in reversal location toward magnetic midnight. This behavior is consistent with that found in studies of the MLT distribution of substorm onsets.
Nuclear magnetic resonance characterization of shallow marine sediments from the Nankai Trough, Integrated Ocean Drilling Program Expedition 333
Authors: Daigle Hugh , Thomas Brittney , Rowe Harry , Nieto Michael
Published: March 2014

We measured nuclear magnetic resonance (NMR) relaxation times on samples from Integrated Ocean Drilling Program Expedition 333 Sites C0011, C0012, and C0018. We compared our results to permeability, grain size, and specific surface measurements, pore size distributions from mercury injection capillary pressure, and mineralogy from X‐ray fluorescence. We found that permeability could be predicted from NMR measurements by including grain size and specific surface to quantify pore networks and that grain size is the most important factor in relating NMR response to permeability. Samples within zones of anomalously high porosity from Sites C0011 and C0012 were found to have different NMR‐permeability relationships than samples from outside these zones, suggesting that the porosity anomaly is related to a fundamental difference in pore structure. We additionally estimated the size of paramagnetic sites that cause proton relaxation and found that in most of our samples, paramagnetic material is present mainly as discrete, clay‐sized grains. This distribution of paramagnetic material may cause pronounced heterogeneity in NMR properties at the pore scale that is not accounted for in most NMR interpretation techniques. Our results provide important insight into the microstructure of marine sediments in the Nankai Trough.
On the apparent attenuation in the spatial coherence estimated from seismic arrays
Authors: Menon Ravishankar , Gerstoft Peter , Hodgkiss William S.
Published: March 2014

Several recent studies have used the coherence of seismic noise between stations to retrieve the phase slowness and attenuation. However, there is considerable debate on the feasibility of attenuation retrieval, its interpretation, and its dependence on the noise directionality and has been the subject of several analytical and numerical studies. In this article, we perform a detailed analysis of the various factors that play a role in the estimation of spatial coherence and attenuation from seismic arrays using data from the Southern California Seismic Network. For instance, certain common preprocessing steps such as averaging neighboring frequencies to improve the estimate are sufficient to introduce attenuation‐like effects. The presence of first‐mode surface Rayleigh wave and P waves in addition to the fundamental mode in Southern California (at frequencies 0.05–0.2 Hz) suggests that the underlying spatial coherence is better modeled as a linear combination of the above wave types. Although this describes the observed coherence better than a simple zeroth‐order Bessel function, the resulting phase cancelations due to the multiple seismic waves can be misconstrued as attenuation if not taken into consideration. Using simulations, we show that due to the slowness inhomogeneity, azimuthally averaging the coherence is not equivalent to homogenizing the medium and instead introduces apparent attenuation in the coherence due to interference. Trying to fit an exponential decay model to this apparent attenuation results in an attenuation coefficient which is similar to previously published results.
The climatic effects of modifying cirrus clouds in a climate engineering framework
Authors: Muri H. , Kristjánsson J. E. , Storelvmo T. , Pfeffer M. A.
Published: March 2014

The climatic effects of climate engineering—or geoengineering—via cirrus cloud thinning are examined. Thinner cirrus clouds can allow more outgoing longwave radiation to escape to space, potentially cooling the climate. The cloud properties and climatic effects due to perturbing the ice crystal fall speed are investigated in a set of hemispheric scale sensitivity experiments with the Community Earth System Model. It is found that increasing the ice crystal fall speed, as an analog to cirrus cloud seeding, depletes high‐level clouds and reduces the longwave cloud forcing. Deliberate depletion of cirrus clouds increases outgoing longwave radiation, reduces the upper tropospheric water vapor, and cools the climate. Global cirrus cloud thinning gave a net cloud forcing change of −1.55 W m−2 and a global annual mean temperature change of −0.94 K. Though there is negligible change in the global annual mean precipitation (−0.001 mm/d), the spatially nonhomogeneous forcing induces circulation changes and hence remote climate changes. Climate engineering the Southern Hemisphere only results in a northward shift of the Intertropical Convergence Zone and possible Sahelian drought alleviation, while targeting the Northern Hemisphere alone causes a greater cooling. It was found that targeting cirrus clouds everywhere outside of the tropics results in changes to the circulation and precipitation even in the nonclimate engineered regions, underscoring the risks of remote side effects and indeed the complexity of the climate system.
Ice surface morphology and flow on Malaspina Glacier, Alaska: Implications for regional tectonics in the Saint Elias orogen
Authors: Cotton Michelle M. , Bruhn Ronald L. , Sauber Jeanne , Burgess Evan , Forster Richard R.
Published: March 2014

The Saint Elias Mountains in southern Alaska are located at a structural syntaxis where the coastal thrust and fold belt of the Fairweather plate boundary intersects thrust faults and folds generated by collision of the Yakutat Terrane. The axial trace of this syntaxis extends southeastward out of the Saint Elias Mountains and beneath Malaspina Glacier where it is hidden from view and cannot be mapped using conventional methods. Here we examine the surface morphology and flow patterns of Malaspina Glacier to infer characteristics of the bedrock topography and organization of the syntaxis. Faults and folds beneath the eastern part of the glacier trend northwest and reflect dextral transpression near the terminus of the Fairweather fault system. Those beneath the western part of the glacier trend northeast and accommodate folding and thrust faulting during collision and accretion of the Yakutat Terrane. Mapping the location and geometry of the structural syntaxis provides important constraints on spatial variations in seismicity, fault kinematics, and crustal shortening beneath Malaspina Glacier, as well as the position of the collisional deformation front within the Yakutat Terrane. We also speculate that the geometrical complexity of intersecting faults within the syntaxis formed a barrier to rupture propagation during two regional Mw 8.1 earthquakes in September 1899.
Whistler mode waves at magnetotail dipolarization fronts
Authors: Viberg H. , Khotyaintsev Yu. V. , Vaivads A. , André M. , Fu H. S. , Cornilleau‐Wehrlin N.
Published: March 2014

We report the statistics of whistler mode waves observed in relation to dipolarization fronts (DFs) in Earth's magnetotail using data from the four Cluster spacecraft spanning a period of 9 years, 2001–2009. We show that whistler mode waves are common in a vicinity of DFs: between 30 and 60% of all DFs are associated with whistlers. Whistlers are about 7 times more likely to be observed near a DF than at any random location in the magnetotail. Therefore, whistlers are a characteristic signature of DFs. We find that whistlers are most often detected in the flux pileup region (FPR) following the DF, close to the center of the current sheet (Bx ∼ 0) and in association with anisotropic electron distributions (T⟂>T∥). This suggests that we typically observe emissions in the source region where they are generated by the anisotropic electrons produced by the betatron process inside the FPR.
Smart pH‐Responsive Nanocarriers Based on Nano‐Graphene Oxide for Combined Chemo‐ and Photothermal Therapy Overcoming Drug Resistance
Authors: Feng Liangzhu , Li Kunyang , Shi Xiaoze , Gao Min , Liu Jian , Liu Zhuang
Published: March 2014

A pH‐responsive nanocarrier is developed by coating nanoscale graphene oxide (NGO) with dual types of polymers, polyethylene glycol (PEG) and poly(allylamine hydrochloride) (PAH), the latter of which is then modified with 2,3‐dimethylmaleic anhydride (DA) to acquire pH‐dependent charge reversibility. After loading with doxorubicin (DOX), a chemotherapy drug, the obtained NGO‐PEG‐DA/DOX complex exhibits a dual pH‐responsiveness, showing markedly enhanced cellular uptake under the tumor microenvironmental pH, and accelerated DOX release under a further lowered pH inside cell lysosomes. Combining such a unique behavior with subsequently slow efflux of DOX, NGO‐PEG‐DA/DOX offers remarkably improved cell killing for drug‐resistant cancer cells under the tumor microenvironmental pH in comparison with free DOX. Exploiting its excellent photothermal conversion ability, combined chemo‐ and photothermal therapy is further demonstrated using NGO‐PEG‐DA/DOX, realizing a synergistic therapeutic effect. This work presents a novel design of surface chemistry on NGO for the development of smart drug delivery systems responding to the tumor microenvironment and external physical stimulus, with the potential to overcome drug resistance.
How Photoinduced Crosslinking Under Operating Conditions Can Reduce PCDTBT‐Based Solar Cell Efficiency and then Stabilize It
Authors: Tournebize Aurélien , Rivaton Agnès , Gardette Jean‐Luc , Lombard Christian , Pépin‐Donat Brigitte , Beaupré Serge , Leclerc Mario
Published: March 2014

Bulk heterojunction (BHJ) photovoltaic devices made of PCDTBT (poly[N‐9′‐hepta‐decanyl‐2,7‐carbazole‐alt‐5,5‐(4′,7′‐di‐2‐thienyl‐2′,1′,3′‐benzothiadiazole)]) and PC70BM ([6,6]‐phenyl‐C70‐butyric acid methyl ester) are among the most efficient and stable devices studied so far. However, during a short regime called “burn‐in”, a significant decrease of power conversion efficiency was observed. A study of the photochemical mechanisms involved in the PCDTBT:PCBM active layer exposed to light in encapsulated systems is presented. It is found that the photochemical reactions resulting from the absorption of light by PCDTBT involve crosslinking between the 2,7 carbazole unit of PCDTBT and the fullerene unit of PCBM. Those reactions stabilize the BHJ by avoiding the formation of microsized PCBM crystals known to cause failure of BHJ solar cells. Using classical electron paramagnetic resonance spectroscopy (EPR) (without illumination), paramagnetic defects along the polymer chains have been detected. The kinetics of defects intensity show a burn‐in trend. The evolution of their relaxation times upon aging is in good agreement with a structural change (crosslinking) of the BHJ observed from the nanomechanical properties. Finally, light‐induced electron paramagnetic resonance (LEPR) measurements performed on aged samples revealed that electron transfer is not significantly affected upon aging, confirming thus the stabilization of the BHJ in solar cell operating conditions.
Fe‐N‐C Oxygen Reduction Fuel Cell Catalyst Derived from Carbendazim: Synthesis, Structure, and Reactivity
Authors: Serov Alexey , Artyushkova Kateryna , Atanassov Plamen
Published: March 2014

New non‐PGM catalysts from the family of Fe‐N‐C pyrolyzed materials are reported. They are synthesized using a templating silica powder with iron nitrate and carbendazim (CBDZ) precursors (sacrificial support method). The synthesis involves high temperature pyrolysis, followed by etching of the sacrificial support (silica) and obtaining a “self‐supported” open frame morphology catalyst. Both the temperature of heat treatment and Fe to CBDZ ratio play a crucial role in the final catalytic activity in oxygen reduction reaction (ORR). Prepared materials have extremely high durability in RDE tests, ending up with more than 94% of initial activity (by E1/2 value) after 10 000 cycles in an oxygen atmosphere, which is the result we report for the first time. Evaluation of these new M‐N‐C catalysts in a single membrane electrode assembly (MEA) has shown an exceptionally high open circuit voltage (OCV) of 1 V and the world's second best performance with no IR correction. MEA tests have shown high current density of 700 mA cm‐2 at 0.6 V and 120 mA cm‐2 at 0.8 V. In‐depth structure‐to‐property correlation presents an evidence that Fe‐Nx centers are the active sites playing a key role in oxygen reduction reaction.
Cobalt‐Embedded Nitrogen‐Rich Carbon Nanotubes Efficiently Catalyze Hydrogen Evolution Reaction at All pH Values
Authors: Zou Xiaoxin , Huang Xiaoxi , Goswami Anandarup , Silva Rafael , Sathe Bhaskar R. , Mikmeková Eliška , Asefa Tewodros
Published: March 2014

Despite being technically possible, splitting water to generate hydrogen is still practically unfeasible due mainly to the lack of sustainable and efficient catalysts for the half reactions involved. Herein we report the synthesis of cobalt‐embedded nitrogen‐rich carbon nanotubes (NRCNTs) that 1) can efficiently electrocatalyze the hydrogen evolution reaction (HER) with activities close to that of Pt and 2) function well under acidic, neutral or basic media alike, allowing them to be coupled with the best available oxygen‐evolving catalysts—which also play crucial roles in the overall water‐splitting reaction. The materials are synthesized by a simple, easily scalable synthetic route involving thermal treatment of Co2+‐embedded graphitic carbon nitride derived from inexpensive starting materials (dicyandiamide and CoCl2). The materials’ efficient catalytic activity is mainly attributed to their nitrogen dopants and concomitant structural defects.
Application of Fundamental Organometallic Chemistry to the Development of a Gold‐Catalyzed Synthesis of Sulfinate Derivatives
Authors: Johnson Miles W. , Bagley Scott W. , Mankad Neal P. , Bergman Robert G. , Mascitti Vincent , Toste F. Dean
Published: March 2014

The development of a gold(I)‐catalyzed sulfination of aryl boronic acids is described. This transformation proceeds through an unprecedented mechanism which exploits the reactivity of gold(I)–heteroatom bonds to form sulfinate anions. Further in situ elaboration of the sulfinate intermediates leads to the corresponding sulfones and sulfonamides, two pharmacophores routinely encountered in drug discovery.
A Coumarin‐Labeled Vinyl Sulfone as Tripeptidomimetic Activity‐Based Probe for Cysteine Cathepsins
Authors: Mertens Matthias D. , Schmitz Janina , Horn Martin , Furtmann Norbert , Bajorath Jürgen , Mareš Michael , Gütschow Michael
Published: March 2014

A coumarin‐tetrahydroquinoline hydride 8 was synthesized as a chemical tool for fluorescent labeling. The rigidified tricyclic coumarin structure was chosen for its suitable fluorescence properties. The connection of 8 with a vinyl sulfone building block was accomplished by convergent synthesis thereby leading to the coumarin‐based, tripeptidomimetic activity‐based probe 10, containing a Gly‐Phe‐Gly motif. Probe 10 was evaluated as inactivator of the therapeutically relevant human cysteine cathepsins S, L, K, and B: it showed particularly strong inactivation of cathepsin S. The detection of recombinant and native cathepsin S was demonstrated by applying 10 to in‐gel fluorescence imaging.
An Independent 1D Single‐Walled Metal–Organic Nanotube Transformed from a 2D Layer Exhibits Highly Selective and Reversible Sensing of Nitroaromatic Compounds
Authors: Zhang Qingfu , Geng Aijing , Zhang Haina , Hu Falu , Lu Zhang‐Hui , Sun Dezhi , Wei Xilian , Ma Chunlin
Published: March 2014

The syntheses and structures of two new ZnII complexes, a 2D graphite‐like layer {[Zn(PIA)H2O]⋅H2O}n (1) and an independent 1D single‐walled metal–organic nanotube (SWMONT) {[Zn2(PIA)2(bpy)2]⋅2.5 H2O⋅DMA}n (2), have been reported based on a “Y”‐shaped 5‐(pyridine‐4‐yl)isophthalic acid ligand (H2PIA). Interestingly, the 2D graphite‐like layer in 1 can transform into the independent 1D SWMONT in 2 with addition of 2,2′‐bipyridine (bpy), which represents the first successfully experimental example of an independent 1D metal–organic nanotube generated from a 2D layer by a “rolling‐up” mechanism.
Substrate‐Oriented Nanorod Scaffolds in Polymer–Fullerene Bulk Heterojunction Solar Cells
Authors: Ogawa Yuta , White Matthew S. , Sun Lina , Scharber Markus C. , Sariciftci Niyazi Serdar , Yoshida Tsukasa
Published: March 2014

The use of a p‐type inorganic semiconductor to form a nanorod scaffold within a polymer‐fullerene bulk heterojunction solar cell is reported. The performance of this cell is compared to those made of the commonly used n‐type scaffold of ZnO, which has been reported many times in the literature. The scaffold is designed to improve charge‐carrier collection by increased mobility in thicker samples. Observations show that generally the device performance shows a negative correlation to nanorod length. By using CuSCN as a p‐type inorganic scaffold, a very similar trend is observed.
Probing Mass Transfer in Mesoporous Faujasite‐Type Zeolite Nanosheet Assemblies
Authors: Mehlhorn Dirk , Inayat Alexandra , Schwieger Wilhelm , Valiullin Rustem , Kärger Jörg
Published: March 2014

Pulsed field gradient nuclear magnetic resonance (NMR) diffusion studies are performed by using cyclohexane to probe transport properties in a NaX‐type zeolite with a hierarchical pore structure (house‐of‐cards‐like assemblies of mesoporous nanosheets), which is compared with a purely microporous sample. With guest loadings chosen to ensure saturation of the micropores, and the meso‐ and macropores left essentially unoccupied, guest diffusion is shown to be enhanced by almost one order of magnitude, even at room temperature. Diffusivity enhancement is further increased with increasing temperature, which may, therefore, be unambiguously attributed to the contribution of mass transfer in the meso‐ and macropores.
High Extinction Coefficient Ru‐Sensitizers that Promote Hole Transfer on Nanocrystalline TiO2
Authors: Abrahamsson Maria , Hedberg Joachim H. J. , Becker Hans‐Christian , Staniszewski Aaron , Pearson Wayne H. , Heuer William B. , Meyer Gerald J.
Published: March 2014

Two series of RuII polypyridyl compounds with formulas [(bpy)2RuL](PF6)2 and [(deeb)2RuL](PF6)2, where bpy is 2,2′‐bipyridine, deeb is 4,4′‐diethylester‐2,2′‐bpy, and L is one of several substituted 9′‐(1,3‐dithiole‐2‐ylidene)‐4′,5′‐diazafluorene ligands, were studied as potential photosensitizers for TiO2. These compounds possess notably high extinction coefficients (≥40 000 M−1 cm−1 @470 nm) which are shown by time‐dependent density functional theory (TD‐DFT) calculations to result from overlapping metal‐to‐ligand charge transfer (MLCT) and ligand‐localized transitions. Low‐temperature absorption and photoluminescence measurements were suggestive of a short‐lived MLCT excited state. When adsorbed onto TiO2 thin films, both the free ligands (L) and their corresponding [(deeb)2RuL]2+ complexes exhibited rapid excited‐state electron injection into TiO2; in the case of the complexes, this was followed by rapid (k>108 s−1) hole transfer from RuIII to the 1,3‐dithiole ring of the L ligand. Observation of diffusion‐limited reductive quenching of the [Ru(bpz)3]2+* (bpz is 2,2′‐bipyrazine) excited state by the L ligands in solution supported the occurrence of intramolecular hole transfer following electron injection by the TiO2‐anchored complexes.
Modeling social‐ecological problems in coastal ecosystems: A case study
Authors: Forrester John , Greaves Richard , Noble Howard , Taylor Richard
Published: March 2014

Complex social‐ecological systems (SES) are not amenable to simple mathematical modeling. However, to address critical issues in SES (e.g., understanding ecological resilience/amelioration of poverty) it is necessary to describe such systems in their entirety. Based on empirical knowledge of local stakeholders and experts, we mapped their conceptions of one SES. Modelers codified what actors told us into two models: a local‐level model and an overarching multiple‐entity description of the system. Looking at these two representations together helps us understand links between the locally specific and other levels of decision taking and vice‐versa. This “bimodeling” approach is investigated in one SES in coastal Kenya. © 2014 Wiley Periodicals, Inc. Complexity 19: 73–82, 2014
Entrepreneurship and the emergence of industrial clusters
Authors: Dilaver Özge , Bleda Mercedes , Uyarra Elvira
Published: March 2014

Innovation and entrepreneurship are the most important catalysts of dynamism in market economies. While it is known that entrepreneurial activities are locally embedded, mutual effects of entrepreneurs and their local regional environment have not been adequately addressed in the existing literature. In this article, we use agent‐based simulation experiments to investigate the role of entrepreneurship in the emergence of regional industrial clusters. We present fundamental extensions to the Simulating Knowledge Dynamics in Innovation Networks model (Ahrweiler et al., Industry and Labor Dynamics: The Agent‐based Computational Economics Approach; World Scientific: Singapore, 2004; pp 284–96) by using a multilevel modeling approach. We analyze the effects of changing entrepreneurial character of regions on the development industrial clusters in two simultaneously simulated regions. We find that an increase in the entrepreneurship of one region has a negative effect on the other region due to competition for factors of production and innovative outputs. The major policy implication of this finding is the limitation it posits on regional innovation and development policies that aspire to support clusters in similar areas of industrial specialization. © 2014 Wiley Periodicals, Inc. Complexity 19: 14–29, 2014
Pt Nanocatalysts Supported on Reduced Graphene Oxide for Selective Conversion of Cellulose or Cellobiose to Sorbitol
Authors: Wang Ding , Niu Wenqi , Tan Minghui , Wu Mingbo , Zheng Xuejun , Li Yanpeng , Tsubaki Noritatsu
Published: March 2014

Pt nanocatalysts loaded on reduced graphene oxide (Pt/RGO) were prepared by means of a convenient microwave‐assisted reduction approach with ethylene glycol as reductant. The conversion of cellulose or cellobiose into sorbitol was used as an application reaction to investigate their catalytic performance. Various metal nanocatalysts loaded on RGO were compared and RGO‐supported Pt exhibited the highest catalytic activity with 91.5 % of sorbitol yield from cellobiose. The catalytic performances of Pt nanocatalysts supported on different carbon materials or on silica support were also compared. The results showed that RGO was the best catalyst support, and the yield of sorbitol was as high as 91.5 % from cellobiose and 58.9 % from cellulose, respectively. The improvement of catalytic activity was attributed to the appropriate Pt particle size and hydrogen spillover effect of Pt/RGO catalyst. Interestingly, the size and dispersion of supported Pt particles could be easily regulated by convenient adjustment of the microwave heating temperature. The catalytic performance was found to initially increase and then decrease with increasing particle size. The optimum Pt particle size was 3.6 nm. These findings may offer useful guidelines for designing novel catalysts with beneficial catalytic performance for biomass conversion.
Fundamentals of the frying process*
Authors: Gertz Christian
Published: March 2014

Considerable interest has been developed over the years in optimizing the frying process. This approach has resulted in a better understanding of the process as a system: oil, food, fryer, and the operation in general. The frying‐process is a complex system depending on the extent of chemical reactions like oxidation, polymerisation, and hydrolysis where the physical and chemical properties of the heated fat are altering. It is difficult to estimate the extent of influence of each factor and to keep the frying conditions at an optimum level. The practical and theoretical aspects of deep‐frying such as oil‐uptake, mechanism of heat and mass‐transfer, and some analytical aspects to monitor the fat degradation are discussed.

Practical applications: Deep‐frying involves close contact between the oil used and the food to be fried. The used oil becomes part of the food and contributes to the flavor, appearance, texture, shelf life, and nutritional value of the final product. A better understanding of the frying process is needed to produce fried products in a more economical way with an optimum flavor and a better shelf‐life.
Improving electrokinetic microdevice stability by controlling electrolysis bubbles
Authors: Lee Hwi Yong , Barber Cedrick , Minerick Adrienne R.
Published: March 2014

The voltage‐operating window for many electrokinetic microdevices is limited by electrolysis gas bubbles that destabilize microfluidic system causing noise and irreproducible responses above ∼3 V DC and less than ∼1 kHz AC at 3 Vpp. Surfactant additives, SDS and Triton X‐100, and an integrated semipermeable SnakeSkin® membrane were employed to control and assess electrolysis bubbles from platinum electrodes in a 180 by 70 μm, 10 mm long microchannel. Stabilized current responses at 100 V DC were observed with surfactant additives or SnakeSkin® barriers. Electrolysis bubble behaviors, visualized via video microscopy at the electrode surface and in the microchannels, were found to be influenced by surfactant function and SnakeSkin® barriers. Both SDS and Triton X‐100 surfactants promoted smaller bubble diameters and faster bubble detachment from electrode surfaces via increasing gas solubility. In contrast, SnakeSkin® membranes enhanced natural convection and blocked bubbles from entering the microchannels and thus reduced current disturbances in the electric field. This data illustrated that electrode surface behaviors had substantially greater impacts on current stability than microbubbles within microchannels. Thus, physically blocking bubbles from microchannels is less effective than electrode functionalization approaches to stabilize electrokinetic microfluidic systems.
Comparison of Arkray/ELITech ADAMS HA‐8180V® with Bio‐Rad Variant,TMII Turbo2.0® and Tosoh Bioscience HLC®‐723G8 for HbA1c Determination
Authors: Badiou Stéphanie , Guillot Julie , Kuster Nils , Bargnoux Anne‐Sophie , Aguilar‐Martinez Patricia , Boissier Elodie , Cristol Jean‐Paul , Dupuy Anne‐Marie
Published: March 2014

Objective

This study aimed to evaluate a new ion‐exchange HPLC system to measure hemoglobin A1c (HbA1c) in comparison to two other widely used HPLC systems.

Methods

Analytical performance and hemoglobin variants detection was assessed on the new Arkray/ELITech ADAMS HA‐8180V®, in parallel to Bio‐Rad VariantTMII Turbo2.0® and Tosoh Bioscience HLC®‐723G8. A method comparison and concordance for the classification of patients according to the American Diabetes Association (ADA) categories was performed using kappa test.

Results

ADAMS HA‐8180V® demonstrated excellent within‐run imprecision (0%) and between‐run imprecision: ≤1.21% using blood sample and ≤0.94% using quality controls. Method comparison of ADAMS HA‐8180V® with the two other systems yielded very high coefficient correlation (r > 0.995). A very good agreement (kappa value ≥0.81) was observed between methods for the classification of patients according to the ADA categories. In addition, all systems were able to detect the presence of most classical variants such as HbC, HbS, HbD, and HbE.

Conclusion

The Arkray/ELITech ADAMS HA‐8180V® demonstrated high analytical performance similar to previous systems such as BioradTMVariant II Turbo 2.0® and Tosoh Bioscience HLC®‐723G8. The three systems allow a high‐quality HbA1c measurement and appeared interchangeable for diabetes diagnosis or for the therapeutic monitoring of patients without hemoglobin variants.
Association Between SRC‐1 Gene Polymorphisms and Coronary Artery Aneurysms Formation in Taiwanese Children With Kawasaki Disease
Authors: Chen Yng‐Tay , Liao Wen‐Lin , Lin Ying‐Ju , Chen Shih‐Yin , Tsai Fuu‐Jen
Published: March 2014

Background

Kawasaki disease (KD) patients who experience a cardiovascular complication known as a coronary artery aneurysm (CAA) are at high risk of developing ischemic heart disease, which may lead to sudden death. The etiology of CAA in KD patients is unclear, and this study aims to clarify the relationship between steroid receptor coactivator‐1 (SRC‐1) gene polymorphisms and CAA pathogenesis.

Methods

We investigated four SRC‐1 gene polymorphisms (rs11894248, rs17791703, rs7572475, and rs9309308) and their correlation with KD with CAA susceptibility in 327 Taiwanese people (279 KD patients without CAA and 48 KD patients with CAA).

Results

The results indicated a statistically significant difference in genotype and allele frequency distributions at the SRC‐1 four single nucleotide polymorphisms (SNPs) between KD patients with and without CAA (P < 0.01). Additionally, Smad3 gene polymorphism (rs12901071) is well known to be associated with KD patients. In our results, Smad3 SNP did not provide a statistically significant difference between KD patients with and without CAA.

Conclusion

Our data show that SRC‐1 polymorphisms may be the underlying cause of CAA; therefore, the polymorphisms examined in this study warrant further investigation.
CORRUPTION AND THE EFFICIENCY OF CAPITAL INVESTMENT IN DEVELOPING COUNTRIES
Authors: O'Toole Conor M. , Tarp Finn
Published: March 2014

This paper tests the effect of corruption on the efficiency of capital investment. Using firm‐level data from the World Bank Enterprise Surveys, covering 90 developing and transition economies, we consider whether the cost of informal bribe payments distorts the efficient allocation of capital by reducing the marginal return per unit investment. Controlling for censoring and endogeneity, we find that bribery decreases investment efficiency. The negative effect is strongest for domestic small‐sized and medium‐sized enterprises. We conclude that reducing the level and incidence of bribery by public officials would facilitate a more efficient allocation of capital. © 2014 The Authors. Journal of International Development published by John Wiley & Sons Ltd.
Synthesis of thinned concentric ring array antenna in predefined phi‐planes using binary firefly and binary particle swarm optimization algorithm
Authors: Chatterjee Anirban , Mahanti G. K. , Mahanti Ananya
Published: March 2014

A binary firefly algorithm inspired by the behavior of artificial fireflies has been applied to thin a planar concentric ring array antenna to minimize the peak sidelobe level in a number of predefined ϕ‐planes. Two different cases comprising two different design specifications for the optimized thinned array have been considered. In the first case, the array is thinned to reduce the peak sidelobe level while keeping the first null beamwidth and half power beamwidth of the array below their specified values in all the defined ϕ‐planes. In the second case, peak sidelobe level of the array is reduced regardless of any pre‐specified values of first null beamwidth and half power beamwidth. To illustrate the superiority of binary firefly algorithm, the thinning of the array for the two different cases has been compared with binary particle swarm optimization algorithm. Results clearly show the superiority of binary firefly algorithm in finding optimum solutions for both cases. Copyright © 2014 John Wiley & Sons, Ltd.
Identification of blood serum micro‐RNAs associated with idiopathic and LRRK2 Parkinson's disease
Authors: Botta‐Orfila Teresa , Morató Xavier , Compta Yaroslau , Lozano Juan José , Falgàs Neus , Valldeoriola Francesc , Pont‐Sunyer Claustre , Vilas Dolores , Mengual Lourdes , Fernández Manel , Molinuevo José Luis , Antonell Anna , Martí Maria José , Fernández‐Santiago Rubén , Ezquerra Mario
Published: March 2014

Blood‐cell‐free circulating micro‐RNAs (miRNAs) have been proposed as potential accessible biomarkers for neurodegenerative diseases such as Parkinson's disease (PD). Here we analyzed the serum levels of 377 miRNAs in a discovery set of 10 idiopathic Parkinson's disease (IPD) patients, 10 PD patients carriers of the LRRK2 G2019S mutation (LRRK2 PD), and 10 controls by using real‐time quantitative PCR‐based TaqMan MicroRNA arrays. We detected candidate differentially expressed miRNAs, which were further tested in a first validation set consisting of 20 IPD, 20 LRRK2 PD, and 20 control samples. We found four statistically significant miRNAs that were downregulated in either LRRK2 or IPD (miR‐29a, miR‐29c, miR‐19a, and miR‐19b). Subsequently, we validated these findings in a third set of samples consisting of 65 IPD and 65 controls and confirmed the association of downregulated levels of miR‐29c, miR‐29a, and miR‐19b in IPD. Differentially expressed miRNAs are predicted to target genes belonging to pathways related to ECM–receptor interaction, focal adhesion, MAPK, Wnt, mTOR, adipocytokine, and neuron projection. Results from our exploratory study indicate that downregulated levels of specific circulating serum miRNAs are associated with PD and suggest their potential use as noninvasive biomarkers for PD. Future studies should further confirm the association of these miRNAs with PD. © 2014 Wiley Periodicals, Inc.
Functional analysis of serine acetyltransferase from Mycobacterium smegmatis
Authors: Qiu Juanjuan , Ma Yufang , Owusu Lawrence , Jiang Tao , Xin Yi
Published: March 2014

Serine acetyltransferase (CysE) is involved in L‐cysteine biosynthesis in Mycobacterium, and it is important for the self‐defense mechanism of the bacteria. Mycobacterium tuberculosis CysE (Rv2335) has been identified as a serine acetyltransferase, and it is orthologous to Mycobacterium smegmatis MSMEG_5947. In this study, the MSMEG_5947 gene was cloned, expressed, and identified as a serine acetyltransferase. To investigate the function of M. smegmatis CysE, a MSMEG_5947 knockout mutant strain (M. sm‐ΔM_5947) was generated through homologous recombination. The growth and morphological characteristics of this strain were studied using growth curves and electron microscopy, respectively. M. sm‐ΔM_5947 grew slower than M. smegmatis mc2155. Electron microscopy revealed that the lack of the M. smegmatis CysE protein caused drastic morphological changes. Therefore, deletion of the serine acetyltransferase retards the growth of the Mycobacterium, but serine acetyltransferase expression is not essential for the survival of the bacteria.
Antiproliferative and immunostimulatory activity of a protein from Pleurotus eryngii
Authors: Mariga Alfred Mugambi , Yang Wen‐jian , Mugambi Dorothy Kemuma , Pei Fei , Zhao Li‐yan , Shao Ya‐ni , Hu Qiuhui
Published: March 2014

BACKGROUND

Currently, the use of mushrooms as functional foods, nutraceuticals or phytopharmaceuticals source has risen. In contrast, the possible cellular cytotoxicity and immunostimulatory activity of Pleurotus eryngii (DC. ex Fr.) Quel protein (PEQP) is unknown. Here we report extraction, anti‐tumorigenic and immunostimulatory activity of PEQP in vitro.

RESULTS

PEQP was extracted from the dried fruiting bodies of P. eryngii, purified and characterised. Its in vitro antiproliferative activity was then evaluated in human non‐small cell lung cancer A549 (NSCLC), stomach adenocarcinoma BGC‐823, hepatocellular carcinoma HepG2 and gastric carcinoma HGC‐27 cell lines using conventional cancer drugs (paclitaxel, doxorubicin and mitomycin C) as positive controls. The protein fractions (PEQP 1, 2, 3 and 4) obtained inhibited tumour cell proliferation dose‐dependently with fraction PEQP 2 having significant (P < 0.05) toxicity in all tumour cells. PEQP had no significant toxicity on normal liver Chang cells but their proliferation was significantly inhibited by mitomycin C. Moreover, PEQP stimulated the proliferation, lysosomal enzyme activity, pinocytosis, nitric oxide and hydrogen peroxide production of RAW 264.7 cell lines dose‐dependently.

CONCLUSION

Based on these results, P. eryngii protein has a potential application in functional foods as a natural anti‐tumour agent with immunostimulatory activity. © 2014 Society of Chemical Industry
Effects of fermentation on antioxidant properties and phytochemical composition of soy germ
Authors: Sheih I‐Chuan , Fang Tony J , Wu Tung‐Kung , Chen Ru‐Yin
Published: March 2014

BACKGROUND

Traditional soy‐fermented foods, such as miso, douche, natto, and tempeh have been widely used as a dietary supplement in Asian countries, and numerous reports on their phenolics and antioxidant activities have been published. Soy germ contains 10‐fold higher phenolics than whole soybean, hence using soy germ as fermentation substrate will be more efficient than whole soybean.

RESULTS

Soy germ fermented with Aspergillus niger M46 resulted in a high‐efficiency bio‐transformation of phenolics and flavonoids to their metabolites, and a diverse secondary metabolic product was also found to response oxidation stress of fungal colonisation. Its antioxidant activity against hydroxyl radicals and superoxide radicals (IC50 = 0.8 and 6.15 µg mL−1, respectively) was about 205‐fold and 47‐fold higher than those of unfermented soy germ (IC50 = 164.0 and 290.48 µg mL−1), respectively. These results were similar to those observed for Trolox, and more active than those of BHT and hesperidin. The β‐glucosidase and α‐amylase produced during fermentation were mainly responsible for mobilisation of the phenolics.

CONCLUSION

Our results demonstrate that fermented soy germ has the potential to be a good dietary supplement for prevention of oxidative stress‐related diseases, and the solid‐state bioprocessing strategy could be an innovative approach to enhance the antioxidant activity of soy germ. © 2014 Society of Chemical Industry
Study of the retention behavior of small polar molecules on different types of stationary phases used in hydrophilic interaction liquid chromatography
Authors: Vlčková Hana , Ježková Kateřina , Štětková Kateřina , Tomšíková Helena , Solich Petr , Nováková Lucie
Published: March 2014

The retention behavior of a large group of analytes (35) with varied properties (pKa and logP) was studied on eight hydrophilic interaction LC columns with different surfaces, stationary phase chemistries, and types of particles. The acetonitrile content (5–95%), buffer concentration (0.5–200 mM), and pH of the mobile phase (3.8 and 6.8) were evaluated for their effects on the retention behavior. The type of stationary phase had a significant impact on the selectivity and retention time of the tested analytes. Completely different selectivity was observed on the aminopropyl stationary phase. In this study, the influence of the buffer concentration was similar for all tested columns, except for the aminopropyl stationary phase. Increasing the buffer concentration led to decreased retention times for the basic compounds and increased retention times for the acidic compounds, while the inverse behavior was observed on the aminopropyl stationary phase. The selectivity of the individual stationary phases was evaluated at pH 3.8 and 6.8. Much lower selectivity differences between the stationary phases were observed at pH 6.8 than pH 3.8. Bare silica stationary phases were used in the comparison of the particles (fused‐core and fully porous particles of 3 and 1.7 μm) and the columns provided by different manufacturers.
Polymers Based on Stable Phenoxyl Radicals for the Use in Organic Radical Batteries
Authors: Jähnert Thomas , Häupler Bernhard , Janoschka Tobias , Hager Martin D. , Schubert Ulrich S.
Published: March 2014

Polymers with pendant phenoxyl radicals are synthesized and the electrochemical properties are investigated in detail. The monomers are polymerized using ring‐opening metathesis polymerization (ROMP) or free‐radical polymerization methods. The monomers and polymers, respectively, are oxidized to the radical either before or after the polymerization. These phenoxyl radicals containing polymers reveal a reversible redox behavior at a potential of −0.6 V (vs Ag/AgCl). Such materials can be used as anode‐active material in organic radical batteries (ORBs).

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A genetically engineered ovarian cancer mouse model based on fallopian tube transformation mimics human high‐grade serous carcinoma development
Authors: Sherman‐Baust Cheryl A , Kuhn Elisabetta , Valle Blanca L , Shih Ie‐Ming , Kurman Robert J , Wang Tian‐Li , Amano Tomokazu , Ko Minoru SH , Miyoshi Ichiro , Araki Yoshihiko , Lehrmann Elin , Zhang Yongqing , Becker Kevin G , Morin Patrice J
Published: March 2014

Recent evidence suggests that ovarian high‐grade serous carcinoma (HGSC) originates from the epithelium of the fallopian tube. However, most mouse models are based on the previous prevailing view that ovarian cancer develops from the transformation of the ovarian surface epithelium. Here, we report the extensive histological and molecular characterization of the mogp–TAg transgenic mouse, which expresses the SV40 large T‐antigen (TAg) under the control of the mouse müllerian‐specific Ovgp‐1 promoter. Histological analysis of the fallopian tubes of mogp–TAg mice identified a variety of neoplastic lesions analogous to those described as precursors to ovarian HGSC. We identified areas of normal‐appearing p53‐positive epithelium that are similar to ‘p53 signatures’ in the human fallopian tube. More advanced proliferative lesions with nuclear atypia and epithelial stratification were also identified that were morphologically and immunohistochemically reminiscent of human serous tubal intraepithelial carcinoma (STIC), a potential precursor of ovarian HGSC. Beside these non‐invasive precursor lesions, we also identified invasive adenocarcinoma in the ovaries of 56% of the mice. Microarray analysis revealed several genes differentially expressed between the fallopian tube of mogp–TAg and wild‐type (WT) C57BL/6. One of these genes, Top2a, which encodes topoisomerase IIα, was shown by immunohistochemistry to be concurrently expressed with elevated p53 and was specifically elevated in mouse STICs but not in the surrounding tissues. TOP2A protein was also found elevated in human STICs, low‐grade and high‐grade serous carcinoma. The mouse model reported here displays a progression from normal tubal epithelium to invasive HGSC in the ovary, and therefore closely simulates the current emerging model of human ovarian HGSC pathogenesis. This mouse therefore has the potential to be a very useful new model for elucidating the mechanisms of serous ovarian tumourigenesis, as well as for developing novel approaches for the prevention, diagnosis and therapy of this disease. Published 2014. This article has been contributed to by US Government employees and their work is in the public domain in the USA.
Temperature‐dependent Kelvin probe studies on GaN from 80 to 600 K
Authors: McNamara J. D. , Baski A. A. , Reshchikov M. A.
Published: March 2014

In this work, we report on the effect of temperature on near‐surface band bending and surface photovoltage (SPV) in GaN. Band bending and SPV during illumination and after switching the illumination off are calculated for n ‐type and p ‐type GaN by using a thermionic model. The temperature and temporal dependencies are compared with experimental data. We find that the thermionic model describes adequately the SPV values and its dynamics only at high temperatures. At temperatures below room temperature the observed SPV is much higher than predicted from the thermionic model, especially in the case of p ‐type GaN. This fact is explained by a significant shift of the quasi‐Fermi level in p ‐type GaN under illumination. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)