bluuebunny/crossref_metadata_2025 huggingface dataset:
A synthetic O2‐tolerant butanol pathway exploiting native fatty acid biosynthesis in Escherichia coli
Authors: Pásztor András , Kallio Pauli , Malatinszky Dávid , Akhtar M. Kalim , Jones Patrik R.
Published: July 2014

Several synthetic metabolic pathways for butanol synthesis have been reported in Escherichia coli by modification of the native CoA‐dependent pathway from selected Clostridium species. These pathways are all dependent on the O2‐sensitive AdhE2 enzyme from Clostridium acetobutylicum that catalyzes the sequential reduction of both butyryl‐CoA and butyraldehyde. We constructed an O2‐tolerant butanol pathway based on the activities of an ACP‐thioesterase, acting on butyryl‐ACP in the native fatty acid biosynthesis pathway, and a promiscuous carboxylic acid reductase. The pathway was genetically optimized by screening a series of bacterial acyl‐ACP thioesterases and also by modification of the physical growth parameters. In order to evaluate the potential of the pathway for butanol production, the ACP‐dependent butanol pathway was compared with a previously established CoA‐dependent pathway. The effect of (1) O2‐availability, (2) media, and (3) co‐expression of aldehyde reductases was evaluated systematically demonstrating varying and contrasting functionality between the ACP‐ and CoA‐dependent pathways. The yield of butanol from the ACP‐dependent pathway was stimulated by enhanced O2‐availability, in contrast to the CoA‐dependent pathway, which did not function well under aerobic conditions. Similarly, whilst the CoA‐dependent pathway only performed well in complex media, the ACP‐dependent pathway was not influenced by the choice of media except in the absence of O2. A combination of a thioesterase from Bacteroides fragilis and the aldehyde reductase, ahr, from E. coli resulted in the greatest yield of butanol. A product titer of ∼300 mg/L was obtained in 24 h under optimal batch growth conditions, in most cases exceeding the performance of the reference CoA‐pathway when evaluated under equivalent conditions. Biotechnol. Bioeng. 2015;112: 120–128. © 2014 Wiley Periodicals, Inc.
In Vivo Incorporation of Non‐canonical Amino Acids by Using the Chemical Aminoacylation Strategy: A Broadly Applicable Mechanistic Tool
Authors: Dougherty Dennis A. , Van Arnam Ethan B.
Published: July 2014

We describe a strategy for incorporating non‐canonical amino acids site‐specifically into proteins expressed in living cells, involving organic synthesis to chemically aminoacylate a suppressor tRNA, protein expression in Xenopus oocytes, and monitoring protein function, primarily by electrophysiology. With this protocol, a very wide range of non‐canonical amino acids can be employed, allowing both systematic structure–function studies and the incorporation of reactive functionalities. Here, we present an overview of the methodology and examples meant to illustrate the versatility and power of the method as a tool for investigating protein structure and function.
SiW11Fe@MIL‐101(Cr) Composite: A Novel and Versatile Electrocatalyst
Authors: Fernandes Diana M. , Granadeiro Carlos M. , Paes de Sousa Patrícia M. , Grazina Raquel , Moura José J. G. , Silva Patrícia , Almeida Paz Filipe A. , Cunha‐Silva Luís , Balula Salete S. , Freire Cristina
Published: July 2014

A novel composite is prepared by the incorporation of the iron‐substituted silicotungstate [SiW11FeIII(H2O)O39]5− (SiW11Fe) into the 3D structure of MIL‐101(Cr). Pyrolytic graphite electrodes are modified with SiW11Fe and the composite material SiW11Fe@MIL‐101, and the electrochemical behavior of the electrodes is studied by cyclic voltammetry. The SiW11Fe‐modified electrode shows three reduction processes: the peak at more positive potentials is assigned to FeIII→FeII and the other two peaks to WVI→WV processes. The SiW11Fe@MIL‐101‐modified electrode shows, besides the redox processes assigned to SiW11Fe, an additional peak from the MIL‐101(Cr) matrix, which corresponds to CrIII→CrII reduction. The SiW11Fe@MIL‐101‐modified electrode shows excellent tungsten‐based electrocatalytic activity towards nitrite and iodate reduction, and chromium‐based electrocatalytic properties towards ascorbic acid oxidation. It, thus, ultimately proves to be a modified electrode with multi‐electrocatalytic properties.
Enhancement of Neighbouring‐Group Participation in Cu0‐Promoted Cross‐Coupling gem‐Difluoromethylenation of Aryl/Alkenyl Halides with 1,3‐Azolic Difluoromethyl Bromides
Authors: Jiang Haizhen , Lu Wenjun , Yang Kun , Ma Guobin , Xu Minjun , Li Jian , Yao Jianhua , Wan Wen , Deng Hongmei , Wu Shaoxiong , Zhu Shizheng , Hao Jian
Published: July 2014

A copper(0)‐promoted direct reductive gem‐difluoromethylenation of unactivated aryl or alkenyl halides with benzo‐1,3‐azolic (oxa‐, thia‐ or aza‐) difluoromethyl bromides or 2‐bromodifluoromethyl‐1,3‐oxazoline has been developed for the construction of pharmaceutically important gem‐difluoromethylene‐linked twin molecules. The unique π‐conjugated aryl‐fused 1,3‐azolic moiety in difluoromethyl bromide substrates could stabilise the reaction intermediates, which promotes the reactivities, providing facile access to the cross‐coupling products in good to excellent yields, and allowing significant functional group tolerance. The reaction exhibits an enhanced neighbouring‐group‐participation effect. This method could provide a new strategy for the construction of gem‐difluoromethylene‐linked identical or nonidentical twin drugs through further functionalisation of 1,3‐azolic skeletons.
Unprecedented Second‐Timescale Blue/Green Emissions and Iodine‐Uptake‐Induced Single‐Crystal‐to‐Single‐Crystal Transformation in ZnII/CdII Metal–Organic Frameworks
Authors: Yuan Shuai , Deng Yong‐Kai , Sun Di
Published: July 2014

The long‐persistent phosphorescent metal–organic framework (MOF) is a kind of highly desirable but rare material. Here, two new molecular MOF materials, {[Zn(tipa)Cl]⋅NO3⋅2 DMF}n (1) and {[Cd2(tipa)2Cl4]⋅6 DMF}n (2) (tipa=tri(4‐imidazolylphenyl)amine), which have 3D twofold interpenetrated (utp) and 2D noninterpenetrated (kgd) topologies, respectively, are reported. They exhibit unexpected long‐persistent emissions yet reported: At 77 K, they persist in glowing after stopping the UV irradiation on a timescale up to seconds at 77 K, which can be detected by the naked eye (ca. 2 s). Compounds 1 and 2 also undergo single‐crystal‐to‐single‐crystal (SC‐SC) transformations through different routes; a simple anion‐exchange route for 1 and a complicated replacement of μ1‐Cl− ions by DMF molecules accompanying I3− captured in the void for 2.
Ultrathin Silica Films: The Atomic Structure of Two‐Dimensional Crystals and Glasses
Authors: Büchner Christin , Lichtenstein Leonid , Yu Xin , Boscoboinik J. Anibal , Yang Bing , Kaden William E. , Heyde Markus , Shaikhutdinov Shamil K. , Włodarczyk Radosław , Sierka Marek , Sauer Joachim , Freund Hans‐Joachim
Published: July 2014

For the last 15 years, we have been studying the preparation and characterization of ordered silica films on metal supports. We review the efforts so far, and then discuss the specific case of a silica bilayer, which exists in a crystalline and a vitreous variety, and puts us into a position to investigate, for the first time, the real space structure (AFM/STM) of a two‐dimensional glass and its properties. We show that pair correlation functions determined from the images of this two‐dimensional glass are similar to those determined by X‐ray and neutron scattering from three‐dimensional glasses, if the appropriate sensitivity factors are taken into account. We are in a position, to verify, for the first time, a model of the vitreous silica structure proposed by William Zachariasen in 1932. Beyond this, the possibility to prepare the crystalline and the glassy structure on the same support allows us to study the crystal‐glass phase transition in real space. We, finally, discuss possibilities to use silica films to start investigating related systems such as zeolites and clay films. We also mention hydroxylation of the silica films in order to adsorb metal atoms modeling heterogenized homogeneous catalysts.
Nanotechnology‐Based Strategies for the Detection and Quantification of MicroRNA
Authors: Degliangeli Federica , Pompa Pier Paolo , Fiammengo Roberto
Published: July 2014

MicroRNAs (miRNAs) are important regulators of gene expression, and many pathological conditions, including cancer, are characterized by altered miRNA expression levels. Therefore, accurate and sensitive quantification of miRNAs may result in correct disease diagnosis establishing these small noncoding RNA transcripts as valuable biomarkers. Aiming at overcoming some limitations of conventional quantification strategies, nanotechnology is currently providing numerous significant alternatives to miRNA sensing. In this review an up‐to‐date account of nanotechnology‐based strategies for miRNA detection and quantification is given. The topics covered are: nanoparticle‐based approaches in solution, sensing based on nanostructured surfaces, combined nanoparticle/surface sensing approaches, and single‐molecule approaches.
Isolable 2,3‐Disila‐1,3‐butadiene from a Double Sila‐Peterson Reaction
Authors: Motomatsu Daiki , Ishida Shintaro , Ohno Koichi , Iwamoto Takeaki
Published: July 2014

A new 2,3‐disila‐1,3‐butadiene (3) was synthesized as pale yellow crystals by a double sila‐Peterson reaction of 1,1,2,2‐tetrasilyl‐1,2‐dilithiodisilane with two equivalents of 2‐adamantanone at 0 °C. In the solid state, the two SiC bonds adopt a synclinal conformation with a dihedral angle of 76.8(1)°. UV/Vis spectra show two distinct absorption bands, assignable to the π(SiC)→π*(SiC) transition, at 371 and 322 nm and the former is considerably redshifted compared with that of structurally similar silenes. The 2,3‐disilabutadiene isomerizes to the corresponding 1,3‐disilabicyclo[1.1.0]butane with the activation parameters of ΔH≠=74.5±5.4 kJ mol−1 and ΔS≠=−71.1±17.1 J mol−1 K−1. DFT studies suggest that the isomerization proceeds through a conrotatory route rather than a disrotatory route. H2O and 9,10‐phenanthrenequinone added across each SiC bond in the 2,3‐disila‐1,3‐butadiene. The UV/Vis spectrum and reactivity of 3 suggest that the interaction between the two SiC bonds in 3 would be significant but rather small compared with that between SiSi bonds in a synclinal tetrasilabutadiene.
Silicone Boronates Reversibly Crosslink Using Lewis Acid– Lewis Base Amine Complexes
Authors: Dodge Laura , Chen Yunqing , Brook Michael A.
Published: July 2014

Silicone elastomers are normally thermosets, which are not readily recycled or repurposed. The few examples of thermoplastic silicone elastomers depend on reversible covalent and non‐covalent molecular interactions. It is demonstrated that amine–boronate complex formation provides a simple and flexible route to reversible crosslinked silicones. A variety of network structures were prepared by use of terminal and pendantly functionalised silicone boronates and amines. The crosslink density was quantified using a combination of Shore‐hardness measurements, swelling, and rheological analyses. Stress induced by compressive force could be relieved through dynamic BN bond reformation at 60 °C. Materials could be fully disassembled through introduction of n‐butylamine and successfully reformed upon removal of the monofunctional amine by evaporation.
Experimental Setup for Incrased Formation of Fouling from Skim Milk Concentrate
Authors: Sprunk Matthias , Nöbel Stefan , Hinrichs Jörg
Published: July 2014

Gasblasen an Erhitzeroberflächen haben entscheidenden Einfluss auf das Fouling proteinhaltiger Medien. Mithilfe von Magermilchkonzentrat wurde die Foulingbildung in einer Versuchsanlage bei standardisierten Bedingungen untersucht. Die gebildeten Foulingschichten wurden in Bezug auf Masse, Schichtdicke und Zusammensetzung analysiert. Die Adsorption von Gasblasen an der Erhitzeroberfläche, eine hohe Wandtemperaturdifferenz und eine niedrige Strömungsgeschwindigkeit beschleunigte das Fouling. Das Wachstum der Gasblasen innerhalb der Foulingschicht erhöhte sich mit fortlaufender Versuchsdauer.
A local moment type estimator for the extreme value index in regression with random covariates
Authors: Goegebeur Yuri , Guillou Armelle , Osmann Michael
Published: July 2014

This article deals with the nonparametric estimation of the conditional extreme value index of a response in the presence of random covariates. In particular, it is assumed that the conditional response distribution belongs to the max‐domain of attraction of the extreme value distribution, and its index is estimated locally within a narrow neighbourhood of the point of interest in the covariate space. The moment estimator, originally introduced in Dekkers, Einmahl, & de Haan (1989), is adjusted to the local estimation context, and its asymptotic properties are investigated under some mild conditions on the response distribution, the density function of the covariates, the kernel function and for appropriately chosen sequences of bandwidth and threshold parameters. The finite sample performance of the proposed estimator is evaluated by means of an extensive simulation study where a comparison with alternatives from the recent literature is provided. We also illustrate the practical applicability of the estimator on the world catalogue of earthquake magnitudes. The Canadian Journal of Statistics 42: 487–507; 2014 © 2014 Statistical Society of Canada
Predicted Ligands for the Human Urotensin‐II G Protein‐Coupled Receptor with Some Experimental Validation
Authors: Kim Soo‐Kyung , Goddard William A. , Yi Kyu Yang , Lee Byung Ho , Lim Chae Jo , Trzaskowski Bartosz
Published: July 2014

Human Urotensin‐II (U‐II) is the most potent mammalian vasoconstrictor known.1 Thus, a U‐II antagonist would be of therapeutic value in a number of cardiovascular disorders.2 Here, we describe our work on the prediction of the structure of the human U‐II receptor (hUT2R) using GEnSeMBLE (GPCR Ensemble of Structures in Membrane BiLayer Environment) complete sampling Monte Carlo method. With the validation of our predicted structures, we designed a series of new potential antagonists predicted to bind more strongly than known ligands. Next, we carried out R‐group screening to suggest a new ligand predicted to bind with 7 kcal mol−1 better energy than 1‐{2‐[4‐(2‐bromobenzyl)‐4‐hydroxypiperidin‐1‐yl]ethyl}‐3‐(thieno[3,2‐b]pyridin‐7‐yl)urea, the designed antagonist predicted to have the highest affinity for the receptor. Some of these predictions were tested experimentally, validating the computational results. Using the pharmacophore generated from the predicted structure for hUT2R bound to ACT‐058362, we carried out virtual screening based on this binding site. The most potent hit compounds identified contained 2‐(phenoxymethyl)‐1,3,4‐thiadiazole core, with the best derivative exhibiting an IC50 value of 0.581 μM against hUT2R when tested in vitro. Our efforts identified a new scaffold as a potential new lead structure for the development of novel hUT2R antagonists, and the computational methods used could find more general applicability to other GPCRs.
Phase 1 study of the antimesothelin immunotoxin SS1P in combination with pemetrexed and cisplatin for front‐line therapy of pleural mesothelioma and correlation of tumor response with serum mesothelin, megakaryocyte potentiating factor, and cancer antigen 125
Authors: Hassan Raffit , Sharon Elad , Thomas Anish , Zhang Jingli , Ling Alexander , Miettinen Markku , Kreitman Robert J. , Steinberg Seth M. , Hollevoet Kevin , Pastan Ira
Published: July 2014

BACKGROUND

The primary objective of this study was to determine the safety and maximum tolerated dose (MTD) of the antimesothelin immunotoxin SS1(dsFv)PE38 (SS1P) (a recombinant antimesothelin immunotoxin consisting of a murine antimesothelin variable antibody fragment [Fv] linked to PE38, a truncated portion of Pseudomonas exotoxin A) in combination with pemetrexed and cisplatin in chemotherapy‐naive patients with advanced malignant pleural mesothelioma (MPM). Secondary objectives included tumor response, SS1P pharmacokinetics, and serum biomarkers of response.

METHODS

Chemotherapy‐naive patients with stage III or IV, unresectable, epithelial or biphasic MPM and normal organ functions were eligible. Pemetrexed (500 mg/m2 on day 1) and cisplatin (75 mg/m2 on day 1) were administered every 3 weeks for up to 6 cycles with escalating doses of SS1P administered intravenously on days 1, 3, and 5 during cycles 1 and 2. Tumor response was evaluated every 6 weeks.

RESULTS

Twenty‐four patients received SS1P at 4 dose levels from 25 to 55 mcg/kg. Grade 3 fatigue was dose‐limiting in 1 patient at 55 mcg/kg. The MTD of SS1P was established as 45 mcg/kg. Other grade 3 toxicities associated with SS1P included hypoalbuminemia (21%), back pain (13%), and hypotension (8%). Of 20 evaluable patients, 12 (60%) had a partial response, 3 had stable disease, and 5 had progressive disease. Of 13 patients who received the MTD, 10 (77%) had a partial response, 1 had stable disease, and 2 had progressive disease. Objective radiologic responses were associated with significant decreases in serum mesothelin (P=.0030), megakaryocyte potentiating factor (P=.0005), and cancer antigen 125 (P < .0001).

CONCLUSIONS

SS1P given with pemetrexed and cisplatin is safe and well tolerated and exhibits significant antitumor activity in patients with unresectable, advanced pleural mesothelioma. Serum mesothelin, megakaryocyte potentiating factor, and cancer antigen 125 levels correlated with objective tumor responses. Cancer 2014;120:3311–3319. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
Translational immunotherapeutics: Chemoimmunotherapy for malignant pleural mesothelioma
Authors: Adusumilli Prasad S.
Published: July 2014

Recent data indicate that chemotherapy treats cancer, at least in part, by facilitating an immune response to the tumor. The study results outlined in this issue highlight the potential benefits in devising an optimal strategy for integrating new immune‐based therapies into the standard of care for various cancers.
Density approach: a new model for BigData analysis and visualization
Authors: Zhang Jinson , Huang Mao Lin
Published: July 2014

In this paper, we extended our density model to BigData analysis and visualization. BigData, which contains images, videos, texts, audio files and other forms of data collected from multiple datasets, is difficult to process and visualize using traditional database management and visualization tools. The challenges are in representing multiple datasets and illustrating and visualizing data patterns to meet business, government and organization needs. We have established the 5Ws density model which uses the 5Ws dimensions for BigData analysis and visualization. The 5Ws dimensions are what the data contain, why the data were transferred, where the data came from, when the data occurred, who received the data and how the data were transferred. According to the network log dataset, an example of BigData, each data incident can be classified into these 5Ws dimensions. The network log dataset ISCX2012 is tested throughout our model. This new model not only classifies network attributes and patterns but also establishes density patterns that provide more analytical features for BigData analysis and visualization. The experimental result shows that this new model with clustered visualization can be efficiently used for BigData analysis and network intrusion detection. Concurrency and Computation: Practice and Experience, 2014.© 2014 Wiley Periodicals, Inc.
Single and Multiple Doping Effects on Charge Transport in Zigzag Silicene Nanoribbons
Authors: Chen Jie , Wang Xue‐Feng , Vasilopoulos Panagiotis , Chen An‐Bang , Wu Jian‐Chun
Published: July 2014

A non‐equilibrium Green’s function technique combined with density functional theory is used to study the spin‐dependent electronic band structure and transport properties of zigzag silicene nanoribbons (ZSiNRs) doped with aluminum (Al) or phosphorus (P) atoms. The presence of a single Al or P atom induces quasibound states in ZSiNRs that can be observed as new dips in the electron conductance. The Al atom acts as an acceptor whereas the P atom acts as a donor if it is placed at the center of the ribbon. This behavior is reversed if the dopant is placed on the edges. Accordingly, an acceptor–donor transition is observed in ZSiNRs upon changing the dopant’s position. Similar results are obtained if two silicon atoms are replaced by two impurities (Al or P atoms) but the conductance is generally modified due to the impurity–impurity interaction. If the doping breaks the twofold rotational symmetry about the central line, the transport becomes spin‐dependent.
Electrocatalytic Oxidation and Adsorption Rate of Methanol at Pt Stepped Single‐Crystal Electrodes and Effect of Ru Step Decoration: A DEMS Study
Authors: Mostafa Ehab , Abd‐El‐Latif Abd‐El‐Aziz A. , Baltruschat Helmut
Published: July 2014

The adsorption and oxidation of methanol at Pt(331) and Ru‐step‐decorated Pt(331) electrodes are studied recording currents and ion currents by online differential electrochemical mass spectrometry. The CO2 current efficiencies and the degree of surface poisoning with COad formed during methanol oxidation are independent of the flow rate, confirming the parallel pathway mechanism. The CO2 current efficiencies decrease with increasing methanol concentration and increase with increasing potential, whereas those of methyl formate show a reverse trend. At potentials higher than 0.6 V, neither the CO2 current efficiencies nor the methanol oxidation currents increase with increasing Ru coverage. Instead, methanol oxidation is inhibited due to blocking of the most active platinum step sites. At potentials lower than 0.6 V, however, not only the onset of methanol oxidation shifts negatively, by about 0.1 V, but also the methanol oxidation current and the CO2 current efficiencies increase. Crucial for the use in fuel cells is the complete oxidation to CO2, which can be achieved if the reactants first adsorb at the electrode surface along the reaction path with adsorbed CO as an intermediate. Therefore, we directly determine the methanol adsorption rates at Pt(331) as well as at Ru‐step‐decorated Pt(331), Pt(332), Pt(100), and Pt(11,1,1) electrodes. The methanol adsorption rate is doubled by a double step density in the case of the Pt(331) and Pt(332) electrodes, higher at higher Ru coverages, and increases by a factor of three upon increasing the potential by 0.1 V (corresponding to a Tafel slope of approximately 200 mV dec−1). At Pt(331) electrodes with partial step decoration, stripping of adsorbed CO (from CO gas) reveals two adsorbate states, which are also discernable when the adsorbate formed from methanol dehydrogenation is stripped.
Temperature Effects on the Capacitance of an Imidazolium‐based Ionic Liquid on a Graphite Electrode: A Molecular Dynamics Simulation
Authors: Liu Xiaohong , Han Yining , Yan Tianying
Published: July 2014

Temperature‐dependent electric double layer (EDL) and differential capacitance–potential (Cd–U) curves of the ionic liquid 1‐butyl‐3‐methylimidazolium hexafluorophosphate (BMIM+/PF6−) were studied on a graphite electrode by molecular dynamics simulations. It was found that all Cd–U curves were asymmetric camel‐shaped with higher Cd at negative polarization, attributed to the specific adsorption of BMIM+. In addition, the maxima of Cd at the negative polarization decrease monotonically with temperature due to the thicker EDL, whereas at the positive polarization they gradually increase from 450 to 550 K and decrease at 600 K. Such temperature effects at positive polarization may be understood in terms of the competition between two aspects: the weakening specific adsorption of BMIM+ allows more effective screening to the positive charge and overall increasing EDL thickness. Although the former dominates from 450 to 550 K, the latter becomes dominant at 600 K.
Surface‐Charge Differentiation of Streptavidin and Avidin by Atomic Force Microscopy–Force Spectroscopy
Authors: Almonte Lisa , Lopez‐Elvira Elena , Baró Arturo M.
Published: July 2014

Chemical information can be obtained by using atomic force microscopy (AFM) and force spectroscopy (FS) with atomic or molecular resolution, even in liquid media. The aim of this paper is to demonstrate that single molecules of avidin and streptavidin anchored to a biotinylated bilayer can be differentiated by using AFM, even though AFM topographical images of the two proteins are remarkably alike. At physiological pH, the basic glycoprotein avidin is positively charged, whereas streptavidin is a neutral protein. This charge difference can be determined with AFM, which can probe electrostatic double‐layer forces by using FS. The force curves, owing to the electrostatic interaction, show major differences when measured on top of each protein as well as on the lipid substrate. FS data show that the two proteins are negatively charged. Nevertheless, avidin and streptavidin can be clearly distinguished, thus demonstrating the sensitivity of AFM to detect small changes in the charge state of macromolecules.
Reduced Graphene Oxide as a Metal‐Free Carbocatalyst for Polymerization of 1‐Naphthylamine
Authors: Tan Lin , Zhang Yong‐Chen , Wang Bin , Luo He‐Ming , Feng Hui‐Xia
Published: July 2014

Invited for this month’s cover is the group of Prof. Huixia Feng from Lanzhou University of Technology, P. R. China. The cover picture shows the catalytic effect of reduced graphene oxide for radical oxidative polymerization of 1‐naphthylamine. Read the full text of the article at 10.1002/cplu.201402020
Centrifugal separation of primary silicon crystal in solvent refining of silicon using Al‐30% Si alloy
Authors: Kim Ki Young , Jeon Je Beom , Shin Jong Sik
Published: July 2014

This study describes the formation of a primary silicon network during separation of an Al‐30% Si melt and the process conditions to make bigger primary silicon crystals. As the crucible rotates in the centrifugal separation, the unfrozen aluminum‐rich phase and small silicon particles are pushed outside through the openings in the silicon network. As a result, primary silicon crystals are separated in the form of a foam after centrifugation. The recovery of the silicon ranged from 13 to 18% depending on the location in the crucible. The size of the primary silicon achieved by changing the cooling rate and quenching temperature during solidification is also measured using a quenching furnace. Primary silicon particles exhibit a coarse, plate‐like morphology, although small star‐like silicon particles are also found in the aluminum‐rich matrix. The fraction of plate silicon decreases, while the fraction of small globular silicon increases with an increasing cooling rate. The thickness of the primary silicon plate also decreases with an increasing cooling rate in the samples quenched at various temperatures during solidification.
Carbon‐Coated Ceramic Membrane Reactor for the Production of Hydrogen by Aqueous‐Phase Reforming of Sorbitol
Authors: D'Angelo M. F. Neira , Ordomsky V. , Schouten J. C. , van der Schaaf J. , Nijhuis T. A.
Published: July 2014

Hydrogen was produced by aqueous‐phase reforming (APR) of sorbitol in a carbon‐on‐alumina tubular membrane reactor (4 nm pore size, 7 cm long, 3 mm internal diameter) that allows the hydrogen gas to permeate to the shell side, whereas the liquid remains in the tube side. The hydrophobic nature of the membrane serves to avoid water loss and to minimize the interaction between the ceramic support and water, thus reducing the risks of membrane degradation upon operation. The permeation of hydrogen is dominated by the diffusivity of the hydrogen in water. Thus, higher operation temperatures result in an increase of the flux of hydrogen. The differential pressure has a negative effect on the flux of hydrogen due to the presence of liquid in the larger pores. The membrane was suitable for use in APR, and yielded 2.5 times more hydrogen than a reference reactor (with no membrane). Removal of hydrogen through the membrane assists in the reaction by preventing its consumption in undesired reactions.
Photoreduction of Iron(III) to Iron(0) Nanoparticles for Simultaneous Hydrogen Evolution in Aqueous Solution
Authors: Wang Chuan‐Jun , Cao Shuang , Qin Biao , Zhang Chen , Li Ting‐Ting , Fu Wen‐Fu
Published: July 2014

Crystalline Fe nanoparticles were obtained with fluorescein (Fl) as the photosensitizer in triethylamine (TEA) or triethanolamine (TEOA) aqueous solution with FeCl3 as the Fe precursor under bright visible‐light light‐emitting diode (LED) irradiation. Photoinduced electron transfer from excited state Fl* and Fl− to Fe3+ produced the Fe nanoparticles, which served as the active catalyst for in situ photocatalytic hydrogen production with Fl and TEA or TEOA as the photosensitizer and electron donors, respectively, in the same system. Robust hydrogen production activities were observed under the Fe nanoparticle photoreduction conditions in basic solution, and tens of milliliters of hydrogen were obtained over prolonged LED irradiation. If inorganic support materials such as NH2‐MCM‐41 or reduced graphene oxide were introduced, dispersed nanoparticles with different sizes and shapes were deposited on the supports, which led to variously enhanced hydrogen production activities. The relationships between the morphologies of the Fe/H2N‐MCM‐41 or Fe/graphene composites generated in situ and the hydrogen production activities were investigated systematically.
Metal–Organic Frameworks at Interfaces in Dye‐Sensitized Solar Cells
Authors: Li Yafeng , Chen Caiyun , Sun Xun , Dou Jie , Wei Mingdeng
Published: July 2014

ZIF‐8, a kind of widely studied metal‐organic frameworks, was used for the interfacial modification of dye‐sensitized solar cells by a facile post‐treatment strategy for the first time, which solved the problem of severely decreased short‐circuit photocurrent in previous report. After the surface treatment, the performance of cells was obviously improved. The conditions for the deposition of ZIF‐8 were optimized. The best photovoltaic property was obtained when the growth time of ZIF‐8 was 7 min and the TiO2 photoanode was post‐treated for 2 times. Besides the energy barrier effect of ZIF‐8 that improved the open‐circuit photovoltage and electron lifetime, the dyes adsorbed tightly on TiO2 surface was found to be a key point for the efficient electron injection and improved performance.
Impact of the Electron‐Transport Layer on the Performance of Solution‐Processed Small‐Molecule Organic Solar Cells
Authors: Long Guankui , Wan Xiangjian , Kan Bin , Hu Zhicheng , Yang Xuan , Zhang Yi , Zhang Mingtao , Wu Hongbing , Huang Fei , Su Shijian , Cao Yong , Chen Yongsheng
Published: July 2014

Although the performance of polymer solar cells has been improved significantly recently through careful optimization with different interlayers for the same materials, more improvement is needed in this respect for small‐molecule‐based solar cells, particularly for the electron‐transport layers (ETLs). In this work, three different solution‐processed ETLs, PFN, ZnO nanoparticles, and LiF, were investigated and compared in the performance of small‐molecule‐based devices, and power conversion efficiencies (PCEs) of 8.32, 7.30, and 7.38 % were achieved, respectively. The mechanism for the ETL‐induced enhancement has been studied, and different ETLs have a significantly different impact on the device performance. The clearly improved performance of PFN is attributed to the combination of reduced bimolecular recombination and increased effective photon absorption in the active layer.
Neonatal amygdala lesions alter mother–infant interactions in rhesus monkeys living in a species‐typical social environment
Authors: Raper Jessica , Stephens Shannon B.Z. , Sanchez Mar , Bachevalier Jocelyne , Wallen Kim
Published: July 2014

The current study examined the effects of neonatal amygdala lesions on mother–infant interactions in rhesus monkeys reared in large species‐typical social groups. Focal observations of mother–infant interactions were collected in their social group for the first 12 months postpartum on infants that had received amygdala lesions (Neo‐A) at 24–25 days of age and control infants. Early amygdala lesions resulted in subtle behavioral alterations. Neo‐A females exhibited earlier emergence of independence from the mother than did control females, spending more time away from their mother, whereas Neo‐A males did not. Also, a set of behaviors, including coo vocalizations, time in contact, and time away from the mother, accurately discriminated Neo‐A females from control females, but not Neo‐A and control males. Data suggest that neonatal amygdalectomy either reduced fear, therefore increasing exploration in females, or reduced the positive reward value of maternal contact. Unlike females, neonatal amygdala lesions had little measurable effects on male mother–infant interactions. The source of this sex difference is unknown. © 2014Wiley Periodicals, Inc. Dev Psychobiol 56: 1711–1722, 2014.
Graphitic Carbon Nitride Nanorods for Photoelectrochemical Sensing of Trace Copper(II) Ions
Authors: Xu Li , Xia Jiexiang , Wang Leigang , Ji Haiyan , Qian Jing , Xu Hui , Wang Kun , Li Huaming
Published: July 2014

A metal‐free polymeric material, graphitic carbon nitride (g‐C3N4) nanorods, has been designed for photoelectrochemical detection of copper(II) ions. The g‐C3N4 nanorods have been fabricated by means of hydrothermally treated bulk g‐C3N4 using NH4Cl. The crystalline structure and the core chemical skeleton of g‐C3N4 do not alter after hydrothermal treatment using NH4Cl. The morphology of g‐C3N4 is changed from nanosheet to nanorod after hydrothermal treatment. The g‐C3N4 nanorods possess significant advantages of enhanced light absorption and charge separation, thereby resulting in an improvement in the photocurrent intensity. A photoelectrochemical sensor has been developed based on the g‐C3N4 nanorods. The results show that the designed sensor has high sensitivity as well as good selectivity for Cu2+ detection. The photoelectrochemical sensor provides a promising method for monitoring metal ions and opens a new avenue for the applications of g‐C3N4 nanorods.
EDTA and α‐tocopherol improve the chemical stability of astaxanthin loaded into nanostructured lipid carriers
Authors: Tamjidi Fardin , Shahedi Mohammad , Varshosaz Jaleh , Nasirpour Ali
Published: July 2014

Nanostructured lipid carriers (NLC) as a promising delivery system have specific advantages over other nanocarriers for food applications. This study was aimed to evaluate the effect of different antioxidants on physical and chemical stability of NLC containing astaxanthin, a hydrophobic nutraceutical. Antioxidants (EDTA, ascorbic acid, α‐tocopherol, coenzyme Q10) were added to aqueous and/or lipid phases. Tween 80 and lecithin were utilized as stabilizers; NLC formulations were produced by melt emulsification‐sonication technique, and then stored at 35°C for 15 days. Except formulations with high levels of EDTA or ascorbic acid, others yielded small nanoparticles (Z‐average ≈ 94 nm) which were stable to growth during storage. Of these antioxidants, only EDTA and α‐tocopherol increased the stability of astaxanthin without causing physical instability, and EDTA was more efficient. The utilization of α‐tocopherol and EDTA in combination was more effective than using them individually. Storage temperature and artificial light had significant effects on the stability of astaxanthin in NLC. These results provide useful information for choosing antioxidants and storage conditions to further protection of nutraceuticals within NLC.

Practical applications: Fortification of aqueous‐based foods with carotenoids is greatly restricted owing to their poor water‐solubility, chemical instability, and low bioavailability. NLC immobilize the encapsulated compounds effectively, and can improve their stability and bioavailability in aqueous‐based foods. However, pro‐oxidants can still decrease the chemical stability of NLC. Different antioxidants were employed to further increase the chemical stability of astaxanthin‐loaded NLC. It was found that degradation of astaxanthin in NLC could be significantly reduced by utilizing proper chelators and free radical scavengers. But, higher temperatures and light could still decrease the stability of astaxanthin. These results provide strong evidences for utilizing metal chelators and free radical scavengers in carotenoids‐loaded NLC, and for storing commercial foods and beverages fortified with these nanoparticles at low temperature and darkness.

Degradation profiles of astaxanthin in astaxanthin‐NLC containing 100 ppm EDTA in aqueous phase and/or different concentrations of α‐tocopherol (in lipid phase) after production (on 0th day) and during storage at 35°C (n = 3).
Pain reduces discrimination in helping
Authors: van Leeuwen Esther , Ashton‐James Claire , Hamaker Ruben J.
Published: July 2014

Because of their shared neurobiological underpinnings, factors increasing physical pain can also increase feelings of social disconnection (“social pain”). Feelings of connection with a social group are reflected in the term social identification, and social identity is commonly associated with intergroup discrimination. In two experiments, we examined the notion that physical pain would reduce social identification and subsequently inhibit intergroup discrimination in helping. By using a pain memory manipulation and a support measure of helping in Study 1 (N = 173), and an actual pain manipulation combined with a behavioural measure of helping in Study 2 (N = 72), results from both studies confirmed the predictions. As expected, physical pain eliminated ingroup favouritism in helping, and identification mediated this effect in the ingroup condition but not in the outgroup condition. We discuss these findings in light of the apparently paradoxical relationship between social support and pain. Copyright © 2014 John Wiley & Sons, Ltd.
All‐Solution‐Processed, Ambient Method for ITO‐Free, Roll‐Coated Tandem Polymer Solar Cells using Solution‐Processed Metal Films
Authors: Angmo Dechan , Dam Henrik F. , Andersen Thomas R. , Zawacka Natalia K. , Madsen Morten V. , Stubager Jørgen , Livi Francesco , Gupta Ritu , Helgesen Martin , Carlé Jon E. , Larsen‐Olsen Thue T. , Kulkarni Giridhar U. , Bundgaard Eva , Krebs Frederik C.
Published: July 2014

A solution‐processed silver film is employed in the processing of top‐illuminated indium‐tin‐oxide (ITO)‐free polymer solar cells in single‐ and double‐junction (tandem) structures. The nontransparent silver film fully covers the substrate and serves as the bottom electrode whereas a PEDOT:PSS/Ag grid forms the semitransparent top electrode. All layers are roll‐coated/printed on a flexible substrate by using only two techniques: slot–die coating for up to 11 consecutive layers and flexo‐printing for the last Ag grid layer. The slot–die coated Ag film is compared to an evaporated Ag film in terms of surface morphological and topographical properties and to ITO in terms of flexibility. The slot–die coated Ag film demonstrates extremely low roughness (a root‐mean‐square roughness of 3 nm was measured over 240×320 μm2 area), is highly conductive (<1 Ω/□), highly flexible, and cost‐effective in comparison to other reported metal films applied in polymer solar cells. Such properties result in high fill factors exceeding 50 % in both single and tandem structures on large‐area devices (1 cm2) and the corresponding efficiencies exceed 2 %.
Differential sensitivity of nitrifying bacteria to silver nanoparticles in activated sludge
Authors: Yang Yu , Li Mengyan , Michels Camila , Moreira-Soares Hugo , Alvarez Pedro J.J.
Published: July 2014

Nitrification is known as one of the most sensitive processes affected when activated sludge is exposed to antimicrobial silver nanoparticles (AgNPs). The impact of AgNPs and their released silver ions (Ag+) on the abundance, activity, and diversity of different nitrifying bacteria in wastewater treatment plants (WWTPs), however, is poorly understood. The present study investigated the impacts of 2 sizes of AgNPs (5 nm and 35 nm) and Ag+ ions on the nitrifier community in activated sludge, including both ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB). Ammonia-oxidizing bacteria were more sensitive to AgNPs than the NOB; a 5-d and 7-d exposure of activated sludge to 35 nm AgNPs (40 ppm) significantly reduced AOB abundance to 24% and 19%, respectively. This finding was confirmed further by a decrease in activated sludge ammonia oxidation activity measured by 14C-labeled bicarbonate uptake. In contrast, neither AgNPs (up to 40 ppm) nor Ag+ (1 ppm) affected the abundance of NOB. Both 5 nm and 35 nm AgNPs decreased the diversity of AOB, as indicated by denaturing gradient gel electrophoresis with ammonia monooxygenase gene (amoA) primers, although some unknown Nitrosomonas species were relatively resistant to AgNPs. The generally greater resistance of NOB than AOB to AgNPs suggests that the accumulation of bacteriostatic nitrite in WWTPs is unlikely to be exacerbated due to the accidental or incidental release of AgNPs. Environ Toxicol Chem 2014;33:2234–2239. © 2014 SETAC
Schwann cells transduced with a lentiviral vector encoding Fgf‐2 promote motor neuron regeneration following sciatic nerve injury
Authors: Allodi Ilary , Mecollari Vasil , González‐Pérez Francisco , Eggers Ruben , Hoyng Stefan , Verhaagen Joost , Navarro Xavier , Udina Esther
Published: July 2014

Fibroblast growth factor 2 (FGF‐2) is a trophic factor expressed by glial cells and different neuronal populations. Addition of FGF‐2 to spinal cord and dorsal root ganglia (DRG) explants demonstrated that FGF‐2 specifically increases motor neuron axonal growth. To further explore the potential capability of FGF‐2 to promote axon regeneration, we produced a lentiviral vector (LV) to overexpress FGF‐2 (LV‐FGF2) in the injured rat peripheral nerve. Cultured Schwann cells transduced with FGF‐2 and added to collagen matrix embedding spinal cord or DRG explants significantly increased motor but not sensory neurite outgrowth. LV‐FGF2 was as effective as direct addition of the trophic factor to promote motor axon growth in vitro. Direct injection of LV‐FGF2 into the rat sciatic nerve resulted in increased expression of FGF‐2, which was localized in the basal lamina of Schwann cells. To investigate the in vivo effect of FGF‐2 overexpression on axonal regeneration after nerve injury, Schwann cells transduced with LV‐FGF2 were grafted in a silicone tube used to repair the resected rat sciatic nerve. Electrophysiological tests conducted for up to 2 months after injury revealed accelerated and more marked reinnervation of hindlimb muscles in the animals treated with LV‐FGF2, with an increase in the number of motor and sensory neurons that reached the distal tibial nerve at the end of follow‐up. GLIA 2014;62:1736–1746
The default mode network is disrupted in parkinson's disease with visual hallucinations
Authors: Yao Nailin , Shek‐Kwan Chang Richard , Cheung Charlton , Pang Shirley , Lau Kui Kai , Suckling John , Rowe James B. , Yu Kevin , Ka‐Fung Mak Henry , Chua Siew‐Eng , Ho Shu Leong. , McAlonan Grainne M.
Published: July 2014

Background: Visual hallucinations (VH) are one of the most striking nonmotor symptoms in Parkinson's disease (PD), and predict dementia and mortality. Aberrant default mode network (DMN) is associated with other psychoses. Here, we tested the hypothesis that DMN dysfunction contributes to VH in PD. Methods: Resting state functional data was acquired from individuals with PD with VH (PDVH) and without VH (PDnonVH), matched for levodopa drug equivalent dose, and a healthy control group (HC). Independent component analysis was used to investigate group differences in functional connectivity within the DMN. In addition, we investigated whether the functional changes associated with hallucinations were accompanied by differences in cortical thickness. Results: There were no group differences in cortical thickness but functional coactivation within components of the DMN was significantly lower in both PDVH and PDnonVH groups compared to HC. Functional coactivation within the DMN was found to be greater in PDVH group relative to PDnonVH group. Conclusion: Our study demonstrates, for the first time that, within a functionally abnormal DMN in PD, relatively higher “connectivity” is associated with VH. We postulate that aberrant connectivity in a large scale network affects sensory information processing and perception, and contributes to “positive” symptom generation in PD. Hum Brain Mapp 35:5658–5666, 2014. © 2014 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.
CORRECTION OF MISCLASSIFICATION ERROR IN DISABILITY RATES
Authors: Gosling Amanda , Saloniki Eirini‐Christina
Published: July 2014

This paper examines misclassification error in survey estimates of disability. The results suggest that a significant number of those with a disability fail to be recorded as such in the British Household Panel Survey. In addition, the probability of a false positive is estimated as being very close to zero in all socio‐demographic groups. There is a strong bias in estimates of differences in rates of disability across groups but only a small effect on estimates of the difference in employment rates by disability status. Copyright © 2014 John Wiley & Sons, Ltd.
Regulation of tumor progression via the Snail‐RKIP signaling pathway by nicotine exposure in head and neck squamous cell carcinoma
Authors: Nieh Shin , Jao Shu‐Wen , Yang Chin‐Yuh , Lin Yaoh‐Shiang , Tseng Yi‐Han , Liu Chia‐Lin , Lee Tsai‐Yu , Liu Tsung‐Yun , Chu Yueng‐Hsiang , Chen Su‐Feng
Published: July 2014

Background

Recent studies suggest that long‐term exposure of the carcinogen 4‐methylnitrosamino‐1–3‐pyridyl‐1‐butanone (NNK) found in tobacco smoke is involved in the progression of head and neck squamous cell carcinoma (HNSCC). The underlying nicotine‐mediated mechanism remains unclear.

Methods

An analysis of SCC‐25 and Fadu cells with or without NNK exposure focusing on the evaluation of migration and invasion abilities, the expression of epithelial–mesenchymal transition, drug‐resistance‐related genes, properties of cancer stem cells (CSCs), and anti‐apoptosis was performed.

Results

Long‐term NNK exposure enhances migration and invasion with morphological alterations in a dose‐dependently manner. Furthermore, NNK exposure also upregulates Snail, promotes sphere‐forming ability, and overexpresses aldehyde dehydrogenase 1 (ALDH1), Nanog, OCT4, ABCG2, and MDR1.

Conclusion

The current study confirmed that long‐term NNK exposure plays a role in HNSCC by increasing anti‐apoptosis and therapeutic resistance via the Snail‐RKIP signaling pathway. Our data also suggest that α7 nicotinic acetylcholine receptor (α7‐nAChR) inhibition or targeting Snail may provide a feasible rationale for preventing the progression of HNSCC. © 2015 Wiley Periodicals, Inc. Head Neck 37: 1712–1721, 2015