bluuebunny/crossref_metadata_2025 huggingface dataset:
Indikatorverdrängungsassays in lebenden Zellen
Authors: Norouzy Amir , Azizi Zahra , Nau Werner M.
Published: November 2014

Der Makrocyclus p‐Sulfonatocalix[4]aren (CX4) und der Fluoreszenzfarbstoff Lucigenin (LCG) bilden einen stabilen Wirt/Gast‐Komplex, in dem die Fluoreszenz des Farbstoffs gelöscht wird. Die Inkubation von lebenden V79‐ und CHO‐Zellen mit dem chemosensorischen Ensemble CX4/LCG führt zu dessen spontaner Aufnahme. Die nachfolgende Zugabe von Cholin, Acetylcholin oder Protamin, die alle eine hohe Affinität für CX4 haben und in der Lage sind, in die Zellen einzudringen, führte zu einer positiven Fluoreszenzantwort der Zellen. Dies kann auf die Verdrängung des LCG aus CX4 durch die Analyten zurückgeführt werden. Die Ergebnisse zeigen die grundsätzliche Funktionsfähigkeit von Indikatorverdrängungsassays mit synthetisch hergestellten Rezeptoren zur Detektion der Aufnahme bioorganischer Analyten in lebenden Zellen.
Combining Organometallic Reagents, the Sulfur Dioxide Surrogate DABSO, and Amines: A One‐Pot Preparation of Sulfonamides, Amenable to Array Synthesis
Authors: Deeming Alex S. , Russell Claire J. , Willis Michael C.
Published: November 2014

We describe a method for the synthesis of sulfonamides through the combination of an organometallic reagent, a sulfur dioxide equivalent, and an aqueous solution of an amine under oxidative conditions (bleach). This simple reaction protocol avoids the need to employ sulfonyl chloride substrates, thus removing the limitation imposed by the commercial availability of these reagents. The resultant method allows access to new chemical space, and is also tolerant of the polar functional groups needed to impart favorable physiochemical properties required for medicinal chemistry and agrochemistry. The developed chemistry is employed in the synthesis of a targeted 70 compound array, prepared using automated methods. The array achieved a 93 % success rate for compounds prepared. Calculated molecular weights, lipophilicities, and polar surface areas are presented, demonstrating the utility of the method for delivering sulfonamides with drug‐like properties.
Molekülchiralität in Meteoriten und interstellarem Eis und das Chiralitätsexperiment an Bord der Kometenmission Rosetta der ESA
Authors: Myrgorodska Iuliia , Meinert Cornelia , Martins Zita , Le Sergeant d'Hendecourt Louis , Meierhenrich Uwe J.
Published: November 2014

Das uns bekannte Leben kontrolliert den ausschließlichen Gebrauch von L‐Aminosäure‐ und D‐Zucker‐Enantiomeren zum molekularen Aufbau von Proteinen und Nukleinsäuren. In diesem Kurzaufsatz wird aktuellen Modellen zum Symmetriebruch in Biomolekülen nachgegangen, die den Transport erdäußerer präbiotischer Moleküle umfassen. Der Kurzaufsatz stellt Enantiomerenüberschüsse dar, wie sie in extraterrestrischen Körpern wie Meteoriten und simuliertem interstellarem Eis nachgewiesen wurden. Die Daten werden aus verschiedenen Blickwinkeln, wie der Photochirogenese, der Paritätsverletzung durch die Schwache Wechselwirkung sowie durch Enantiomerenanreicherungen durch Phasenübergänge interpretiert. Im aktuellen Kontext des Chiralitätsmoduls an Bord der Kometensonde Rosetta der ESA, die erstmals enantioselektive In‐situ‐Messungen an Proben eines Kometenkerns durchführt, wird die photochemisch induzierte “chirale Asymmetrie” genauer diskutiert werden.
Redox‐Active Ligand‐Induced Homolytic Bond Activation
Authors: Broere Daniël L. J. , Metz Lotte L. , de Bruin Bas , Reek Joost N. H. , Siegler Maxime A. , van der Vlugt Jarl Ivar
Published: November 2014

Coordination of the novel redox‐active phosphine‐appended aminophenol pincer ligand (PNOH2) to PdII generates a paramagnetic complex with a persistent ligand‐centered radical. The complex undergoes fully reversible single‐electron oxidation and reduction. Homolytic bond activation of diphenyldisulfide by the single‐electron reduced species leads to a ligand‐based mixed‐valent dinuclear palladium complex with a single bridging thiolate ligand. Mechanistic investigations support an unprecedented intramolecular ligand‐to‐disulfide single‐electron transfer process to induce homolytic SS cleavage, thereby releasing a thiyl (sulfanyl) radical. This could be a new strategy for small‐molecule bond activation.
Cofactor‐Free Light‐Driven Whole‐Cell Cytochrome P450 Catalysis
Authors: Park Jong Hyun , Lee Sahng Ha , Cha Gun Su , Choi Da Som , Nam Dong Heon , Lee Jae Hyung , Lee Jung‐Kul , Yun Chul‐Ho , Jeong Ki Jun , Park Chan Beum
Published: November 2014

Cytochromes P450 can catalyze various regioselective and stereospecific oxidation reactions of non‐functionalized hydrocarbons. Here, we have designed a novel light‐driven platform for cofactor‐free, whole‐cell P450 photo‐biocatalysis using eosin Y (EY) as a photosensitizer. EY can easily enter into the cytoplasm of Escherichia coli and bind specifically to the heme domain of P450. The catalytic turnover of P450 was mediated through the direct transfer of photoinduced electrons from the photosensitized EY to the P450 heme domain under visible light illumination. The photoactivation of the P450 catalytic cycle in the absence of cofactors and redox partners is successfully conducted using many bacterial P450s (variants of P450 BM3) and human P450s (CYPs 1A1, 1A2, 1B1, 2A6, 2E1, and 3A4) for the bioconversion of different substrates, including marketed drugs (simvastatin, lovastatin, and omeprazole) and a steroid (17β‐estradiol), to demonstrate the general applicability of the light‐driven, cofactor‐free system.
Organic Donor–Acceptor Assemblies form Coaxial p–n Heterojunctions with High Photoconductivity
Authors: Prasanthkumar Seelam , Ghosh Samrat , Nair Vijayakumar C. , Saeki Akinori , Seki Shu , Ajayaghosh Ayyappanpillai
Published: November 2014

The formation of coaxial p–n heterojunctions by mesoscale alignment of self‐sorted donor and acceptor molecules, important to achieve high photocurrent generation in organic semiconductor‐based assemblies, remains a challenging topic. Herein, we show that mixing a p‐type π gelator (TTV) with an n‐type semiconductor (PBI) results in the formation of self‐sorted fibers which are coaxially aligned to form interfacial p–n heterojunctions. UV/Vis absorption spectroscopy, powder X‐ray diffraction studies, atomic force microscopy, and Kelvin‐probe force microscopy revealed an initial self‐sorting at the molecular level and a subsequent mesoscale self‐assembly of the resulted supramolecular fibers leading to coaxially aligned p–n heterojunctions. A flash photolysis time‐resolved microwave conductivity (FP‐TRMC) study revealed a 12‐fold enhancement in the anisotropic photoconductivity of TTV/PBI coaxial fibers when compared to the individual assemblies of the donor/acceptor molecules.
Bayesian gamma processes for optimizing condition‐based maintenance under uncertainty
Authors: Bousquet N. , Fouladirad M. , Grall A. , Paroissin C.
Published: November 2014

The aim of this article is twofold: (i) modeling partially observed crack growth of industrial components using gamma processes and (ii) providing estimators of the best maintenance time in a statistical Bayesian framework. The choice of a Bayesian framework is motivated by the small size of data, the availability of expert knowledge about the crack propagation, and more generally, the concern about the integration of parametrical uncertainties when optimizing a maintenance action. The article answers to the methodological question of Bayesian prior elicitation by adopting a strategy based on virtual data information and defines optimal replacement times as posterior Bayes estimators minimizing appropriate cost functions. More precisely, the industrial data are described, and two different levels of available information are considered. Then, the Bayesian parameter estimation procedure in each case is thoroughly explained, by conducting MCMC runs. Different criteria for maintenance optimization, taking account all uncertainties, are considered and discussed. The overall procedure is tested on simulated data and applied over a real dataset. Copyright © 2014 John Wiley & Sons, Ltd.
Giving and sharing in the computer‐mediated economy
Authors: Harvey John , Smith Andrew , Golightly David
Published: November 2014

The paper examines how digital technology mediates the behaviour of consumers in three online systems that facilitate offline gift giving and sharing (Freecycle, Couchsurfing, and Landshare). Findings derived from a netnography and depth interviews reveal how technology is used to enact and influence the management of identity, partner selection, ritual normalisation, and negotiation of property rights. The findings have significant implications for the design and management of systems that encourage non‐monetary forms of collaborative consumption. Copyright © 2014 John Wiley & Sons, Ltd.
Rosiglitazone, a PPARγ agonist, ameliorates palmitate‐induced insulin resistance and apoptosis in skeletal muscle cells
Authors: Meshkani Reza , Sadeghi Asie , Taheripak Gholamreza , Zarghooni Maryam , Gerayesh‐Nejad Siavash , Bakhtiyari Salar
Published: November 2014

Palmitate induces insulin resistance and apoptosis in insulin target tissues. Rosiglitazone (RSG), a peroxisome proliferator‐activated receptor γ (PPARγ) agonist, can activate both pro‐apoptotic and anti‐apoptotic pathways in different cells; however, its effect on palmitate‐induced apoptosis in skeletal muscle cells remains to be elucidated. After differentiation of C2C12 cells, myotubes were treated with palmitate, RSG and GW9662 (PPARγ antagonist). MTT and terminal deoxynucleotide transferase dUTP nick end labelling (TUNEL) assays and caspase‐3 activity were used to investigate the apoptosis. To study the underlying mechanism, glucose uptake, gene expression and protein levels were evaluated. A total of 0.75 mM palmitate reduced cell viability by 43% and increased TUNEL‐positive cells and caspase‐3 activity by 15‐fold and 6.6‐fold, respectively. RSG (10 μM) could markedly decrease the level of TUNEL‐positive cells and caspase‐3 activity in palmitate‐treated cells. The protective effect of RSG on apoptosis was abrogated by GW9662. To investigate the molecular mechanism of this effect, gene expression and protein level of protein tyrosine phosphatase 1B (PTP1B) were evaluated. Palmitate and RSG individually increased the expression and protein level of PTP1B, whereas combined treatment (palmitate and RSG) were able to further increase the expression of PTP1B in C2C12 cells. We also evaluated the effect of RSG on palmitate‐induced insulin resistance in muscle cells. RSG could significantly improve glucose uptake by 0.4‐fold in myotubes treated with palmitate. Moreover, RSG could restore the phosphorylation of Akt in palmitate‐treated cells. These data suggest that RSG protects skeletal muscle cells against palmitate‐induced apoptosis and this effect appears to be mediated via the PPARγ‐dependent and PTP1B‐independent mechanisms. Copyright © 2014 John Wiley & Sons, Ltd.

SIGNIFICANCE OF THE STUDY

Saturated free fatty acids (FFAs), such as palmitate, have been shown to induce cellular apoptosis. Strategies for preventing the cytotoxic effect of palmitate are useful in reduction of diabetes complications. In this study, we introduced RSG as an agent that protects skeletal muscle cells against palmitate‐induced apoptosis and insulin resistance. It appears that RSG protects skeletal muscle cells against palmitate‐induced apoptosis via the PPARγ‐dependent and PTP1B‐independent mechanisms. Given the role of FFAs in skeletal muscle apoptosis, these findings support the idea that RSG can ameliorate diabetes complications such as skeletal muscle loss.
Enhanced Oxidative Desulfurization of Dibenzothiophene by Functional Mo‐Containing Mesoporous Silica
Authors: Zhang Ming , Zhu Wenshuai , Xun Suhang , Xiong Jun , Ding Wenjing , Li Meng , Wang Qian , Li Huaming
Published: November 2014

Functional mesoporous Mo–SiO2 materials were synthesized by a one‐pot and facile room‐temperature procedure, and characterized by X‐ray diffraction, TEM, Raman spectroscopy, FT‐IR, diffuse reflectance spectra, and BET analysis. The experimental results demonstrated that the mesoporous materials presented a high dispersion of molybdenum species and excellent catalytic activity for the removal of dibenzothiophene (DBT) without organic solvents as extractants. The catalytic performance on different sulfur‐containing compounds was also investigated in detail. After recycling for eight times, the removal of the oxidation desulfurization system could still reach high values. GC‐MS analysis detected the oxidation product of DBT. A mechanism was proposed for the absorptive oxidation process of sulfur compounds.
Modeling, Characteristic Analysis and Optimization of an Improved Heat‐Integrated Air Separation Column
Authors: Chang Liang , Liu Xinggao
Published: November 2014

Cryogenic air separation as the most important part of an integrated gasification combined cycle is a widely used operation unit for producing large quantities of high‐purity oxygen and nitrogen. However, cryogenic distillation requires a large amount of energy due to the work needed to compress the air feed. An improved heat‐integrated air separation column (HIASC) is proposed. The requirements of high‐purity separation in the industrial cryogenic air separation process are achieved. An optimization model of the heat transfer coefficient (UA), a key parameter in column structure design and operation, is presented. The optimized UA value is obtained within the accepted value range reported in the international open literature, which ensures the practicability of the improved HIASC.
Sorption of Acetaldehyde and Hexanal in Trace Concentrations on Carbon‐Based Adsorbents
Authors: Ortmann Roman , Pasel Christoph , Luckas Michael , Kraas Sebastian , Fröba Michael , Bathen Dieter
Published: November 2014

Adsorption processes are frequently applied to separate traces of hazardous and toxic substances from gas streams. Hence, knowledge of sorption characteristics of these substances on standard adsorbents is essential. Sorption of hexanal and acetaldehyde from a nitrogen gas stream in trace concentrations on activated carbon and ordered mesoporous carbon‐based adsorbents (CMK) is studied. A magnetic suspension balance and an attached gaschromatograph‐mass spectrometer were used to analyze the sorption process both gravimetrically and spectrometrically. Both types of adsorbents show a higher capacity for hexanal than acetaldehyde. The activated carbon exhibits considerable differences in regard to desorption of hexanal compared to the mesoporous CMK.
Superior Lithium‐Ion Storage Properties of Si‐Based Composite Powders with Unique Si@Carbon@Void@Graphene Configuration
Authors: Choi Seung Ho , Jung Dae Soo , Choi Jang Wook , Kang Yun Chan
Published: November 2014

Composite powders of the configuration Si@carbon@void@graphene were prepared by a one‐step spray pyrolysis process, by adding polyvinylpyrrolidone (PVP) to a precursor solution containing graphene oxide (GO) sheets and silicon nanoparticles (NPs). Morphological analysis indicates that the individual Si NPs are coated with amorphous carbon and encapsulated in a micrometer‐sized graphene ball structure that offers a large amount of buffer space. The addition of PVP improves the stability of the colloidal spray solution containing the GO sheets and the Si NPs. Consequently, the prepared Si@C@void@graphene composite powders have a relatively more uniform morphology than the Si@void@graphene composite powders prepared from the spray solution without PVP. The first charge and discharge capacities of the Si@C@void@graphene electrode measured at 0.1 A g−1 are as high as 3102 and 2215 mA h g−1, respectively. With an increase in the current rate from 0.5 to 11 A g−1, 46 % of the original capacity (i.e., 2134 mA h g−1) is maintained. After 500 cycles at a high rate of 7 A g−1, the Si@C@void@graphene electrode shows 84 % capacity retention and 99.8 % of the average Coulombic efficiency. The superior cycling and rate capabilities of the prepared Si@C@void@graphene electrode could be attributed to the uniform carbon coating of the Si NPs and the graphene ball structure, which facilitates efficient diffusion of Li ions and prevents the penetration of electrolyte into graphene ball during cycling.
Chemically and Electrochemically Triggered Assembly of Viologen Radicals: Towards Multiaddressable Molecular Switches
Authors: Kahlfuss Christophe , Métay Estelle , Duclos Marie‐Christine , Lemaire Marc , Milet Anne , Saint‐Aman Eric , Bucher Christophe
Published: November 2014

We have established that bipyridinium radicals can be reversibly π‐dimerized under the combined effects of chemical (proton transfer) and electrochemical (electron transfer) stimuli. Our investigations also led to the discovery that a bis‐pyridinyl appended calixarene intermediate is involved in a fully reversible redox‐triggered σ‐dimerization process. The structure of the most stable intramolecular σ‐dimer was provided by computational chemistry and its complete conversion into a noncovalent π‐dimer could be triggered chemically by addition of protons, leading to the formation of protonated cation radicals. Theoretical data collected with the N‐methylated and N‐protonated π‐dimers also support the existence of multivariant orientations in π‐bonded dimers of viologen cation‐radicals.
Enhancing Effects of Salt Formation on Catalytic Activity and Enantioselectivity for Asymmetric Hydrogenation of Isoquinolinium Salts by Dinuclear Halide‐Bridged Iridium Complexes Bearing Chiral Diphosphine Ligands
Authors: Kita Yusuke , Yamaji Kenta , Higashida Kosuke , Sathaiah Kandula , Iimuro Atuhiro , Mashima Kazushi
Published: November 2014

Asymmetric hydrogenation of 1‐ and 3‐substituted and 1,3‐disubstituted isoquinolinium chlorides using triply halide‐bridged dinuclear iridium complexes [{Ir(H)(diphosphine)}2(μ‐Cl)3]Cl has been achieved by the strategy of HCl salt formation of isoquinolines to afford the corresponding chiral 1,2,3,4‐tetrahydroisoquinolines (THIQs) in high yields and with excellent enantioselectivities after simple basic work‐up. The effects of salt formation have been investigated by time‐course experiments, which revealed that the generation of isoquinolinium chlorides clearly prevented formation of the catalytically inactive dinuclear trihydride complex, which was readily generated in the catalytic reduction of salt‐free isoquinoline substrates. Based on mechanistic investigations, including by 1H and 31P{1H} NMR studies and the isolation and characterization of several intermediates, the function of the chloride anion of the isoquinolinium chlorides has been elucidated, allowing us to propose a new outer‐sphere mechanism involving coordination of the chloride anion of the substrates to an iridium dihydride species along with a hydrogen bond between the chloride ligand and the N‐H proton of the substrate salt.
Optical, Electrochemical, and Magnetic Properties of Pyrrole‐ and Thiophene‐Bridged 5,15‐Diazaporphyrin Dimers
Authors: Omomo Satoshi , Maruyama Yasuhisa , Furukawa Ko , Furuyama Taniyuki , Nakano Haruyuki , Kobayashi Nagao , Matano Yoshihiro
Published: November 2014

The first examples of pyrrole‐ and thiophene‐bridged 5,15‐diazaporphyrin (DAP) dimers are prepared through Stille coupling reactions of nickel(II) and copper(II) complexes of 3‐bromo‐10,20‐dimesityl‐5,15‐diazaporphyrin (mesityl=2,4,6‐trimethylphenyl) with the respective 2,5‐bis(tributylstannyl)heteroles. The effects of the heterole spacers and meso nitrogen atoms on the optical, electrochemical, and magnetic properties of the DAP dimers are investigated by UV/Vis absorption spectroscopy, density functional theory calculations, magnetic circular dichroism spectroscopy, cyclic voltammetry, and EPR spectroscopy. The heterole spacers are found to have a significant impact on the electronic transitions over the entire π‐system. In particular, the pyrrole‐bridged DAP dimers exhibit high light‐harvesting potential in the low‐energy visible/near‐infrared region owing to the intrinsic charge‐transfer character of the lowest excitation.
Thienoacene‐Fused Pentalenes: Syntheses, Structures, Physical Properties and Applications for Organic Field‐Effect Transistors
Authors: Dai Gaole , Chang Jingjing , Shi Xueliang , Zhang Wenhua , Zheng Bin , Huang Kuo‐Wei , Chi Chunyan
Published: November 2014

Three soluble and stable thienoacene‐fused pentalene derivatives (1–3) with different π‐conjugation lengths were synthesized. X‐ray crystallographic analysis and density functional theory (DFT) calculations revealed their unique geometric and electronic structures due to the interaction between the aromatic thienoacene units and antiaromatic pentalene moiety. As a result, they all possess a small energy gap and show amphoteric redox behaviour. Time dependent (TD) DFT calculations were used to explain their unique electronic absorption spectra. These new compounds exhibited good thermal stability and ordered packing in solid state and thus their applications in organic field‐effect transistors (OFETs) were also investigated. The highest field‐effect hole mobility of 0.016, 0.036 and 0.001 cm2 V−1 s−1 was achieved for solution‐processed thin films of 1–3, respectively.
Nanoscaled Copper Metal–Organic Framework (MOF) Based on Carboxylate Ligands as an Efficient Heterogeneous Catalyst for Aerobic Epoxidation of Olefins and Oxidation of Benzylic and Allylic Alcohols
Authors: Qi Yue , Luan Yi , Yu Jie , Peng Xiong , Wang Ge
Published: November 2014

Aerobic epoxidation of olefins at a mild reaction temperature has been carried out by using nanomorphology of [Cu3(BTC)2] (BTC=1,3,5‐benzenetricarboxylate) as a high‐performance catalyst through a simple synthetic strategy. An aromatic carboxylate ligand was employed to furnish a heterogeneous copper catalyst and also serves as the ligand for enhanced catalytic activities in the catalytic reaction. The utilization of a copper metal–organic framework catalyst was further extended to the aerobic oxidation of aromatic alcohols. The shape and size selectivity of the catalyst in olefin epoxidation and alcohol oxidation was investigated. Furthermore, the as‐synthesized copper catalyst can be easily recovered and reused several times without leaching of active species or significant loss of activity.
Effect of modification and regulation on physicochemical properties of clinoptilolite, as well as nitrogen and phosphates removal performance
Authors: Lin Hai , Zheng Qianqian , Dong Yingbo , Jin Xin , Zhang Xiaopei , Liu Quanli
Published: November 2014

Natural clinoptilolite was modified by NaCl‐firing to produce modified clinoptilolite. Afterwards, the modified clinoptilolite was regulated by LaCl3 to produce composite clinoptilolite. Modified clinoptilolite and composite clinoptilolite were used to adsorb ammonia‐nitrogen and phosphates from wastewater. The modified clinoptilolite and composite clinoptilolite had high sorption efficiency and removal performance. The ammonia‐nitrogen and phosphate removal rate of the modified clinoptilolite reached 96.46 % and the phosphate removal rate of the composite clinoptilolite reached 86.26 %. Furthermore, the structure was characterized by SEM, EDS, XRD, IR, and N2‐porosimetry analyses. Results showed that the surface of modified clinoptilolite became loose and some pores appeared, which increased the specific surface area. In addition, total pore volume, micropore area and average pore width increased after modification by NaCl firing and LaCl3 regulation, where in the micropore area exhibited the highest increase. The modification process did not change the overall skeletal structure and structural holes for both the modified clinoptilolite and the composite clinoptilolite. The main components were Si, Al, and O. The Na ion content of the modified clinoptilolite increased from 0.77 % to 2.45 % and the La ion content of composite clinoptilolite increased from 0 % to 2.52 %. The modification and regulation mechanisms were based on the Na+ replace Ca2+ and Mg2+ of clinoptilolite. Hydrous lanthanum oxide could be loaded only to the surface of clinoptilolites. In addition, the ion‐exchange capacity of both the modified clinoptilolite and the composite clinoptilolite improved compared with natural clinoptilolite.
Integration of grid, cluster and cloud resources to semantically annotate a large‐sized repository of learning objects
Authors: Fabra Javier , Hernández Sergio , Otero Estefanía , Vidal Juan C. , Lama Manuel , Álvarez Pedro
Published: November 2014

The Universia repository is composed of more than 15 million of educational resources. The lack of metadata describing these resources complicates their classification, search and recovery. To overcome this drawback, it was decided to semantically annotate the available educational resources using the ADEGA algorithm. For this objective, we selected the DBpedia, a cross‐domain linked data composed of more than 3.77 million ‘things’ with 400 million ‘facts’, in order to make sure that the wide range of Universia topics are covered by the ontology. However, this kind of process is extremely expensive from a computational point of view: more than 1600 years of CPU time was estimated to achieve it. In this paper, parallel programming techniques and distributed computing paradigms are combined in order to achieve this semantic annotation in a reasonable time. The cornerstone of this proposal is a resource management and execution framework able to integrate heterogeneous computing resources at our disposal (grid, cluster and cloud resources). As a result, the problem was solved in less than 180 days, demonstrating that it is perfectly feasible to exploit the advantages of these computing models in the field of linked data. Copyright © 2014 John Wiley & Sons, Ltd.
Distributed wikis: a survey
Authors: Davoust Alan , Skaf‐Molli Hala , Molli Pascal , Esfandiari Babak , Aslan Khaled
Published: November 2014

‘Distributed wiki’ is a generic term covering various systems, including ‘peer‐to‐peer wiki’, ‘mobile wiki’, ‘offline wiki’, ‘federated wiki’ and others. Distributed wikis distribute their pages among the sites of autonomous participants to address various motivations, including high availability of data, new collaboration models and different viewpoints of subjects. Although existing systems share some common basic concepts, it is often difficult to understand the specificity of each one, the underlying complexities or the best context in which to use it. In this paper, we define, classify and characterize distributed wikis. We identify three classes of distributed wiki systems, each using a different collaboration model and distribution scheme for its pages: highly available wikis, decentralized social wikis and federated wikis. We classify existing distributed wikis according to these classes. We detail their underlying complexities and social and technical motivations. We also highlight some directions for research and opportunities for new systems with original social and technical motivations. Copyright © 2014 John Wiley & Sons, Ltd.
Detection of repackaged mobile applications through a collaborative approach
Authors: Aldini Alessandro , Martinelli Fabio , Saracino Andrea , Sgandurra Daniele
Published: November 2014

Repackaged applications are based on genuine applications, but they subtlety include some modifications. In particular, trojanized applications are one of the most dangerous threats for smartphones. Malware code may be hidden inside applications to access private data or to leak user credit. In this paper, we propose a contract‐based approach to detect such repackaged applications, where a contract specifies the set of legal actions that can be performed by an application. Current methods to generate contracts lack information from real usage scenarios, thus being inaccurate and too coarse‐grained. This may result either in generating too many false positives or in missing misbehaviors when verifying the compliance between the application and the contract. In the proposed framework, application contracts are generated dynamically by a central server merging execution traces collected and shared continuously by collaborative users executing the application. More precisely, quantitative information extracted from execution traces is used to define a contract describing the expected application behavior, which is deployed to the cooperating users. Then, every user can use the received contract to check whether the related application is either genuine or repackaged. Such a verification is based on an enforcement mechanism that monitors the application execution at run‐time and compares it against the contract through statistical tests. Copyright © 2014 John Wiley & Sons, Ltd.
Pitfalls of fine‐needle aspiration cytology of parotid membranous basal cell adenoma—A review of pitfalls in FNA cytology of salivary gland neoplasms with basaloid cell features
Authors: Jurczyk Matthew , Peevey Joseph F. , Vande Haar Mark A. , Lin Xiaoqi
Published: November 2014

Membranous basal cell adenoma (MBCA) is a rare benign salivary gland neoplasm. It is difficult to diagnose MBCA based on fine‐needle aspiration (FNA) cytology due to rare reporting of its FNA cytology and overlapping of its FNA cytologic features with some benign and malignant entities. We present a case of MBCA in a 67‐year‐old female that was originally misinterpreted as adenoid cystic carcinoma (ACC) on FNA cytology. The FNA smears showed numerous uniform small basaloid epithelial cells with round or oval nuclei and inconspicuous nucleoli, and scant cytoplasm. The basaloid cells surround acellular, dense, homogenous material or are surrounded by acellular or paucicellular dense homogeneous material possibly containing bland spindle cells. The basaloid cells are present in variably sized three‐dimensional clusters, acini, or sheets with variable cohesion. The dense homogenous material surrounded by basaloid cells may be interconnected. High power magnification reveals the homogeneous material to have a fibrillar texture. The edges of dense homogenous materials were well‐demarcated. We describe the diagnostic pitfalls of FNA for MBCA, particularly versus ACC, basal cell adenoma, cellular pleomorphic adenoma, myoepithelioma, basal cell adenocarcinoma, and basaloid squamous cell carcinoma in hope of improving clinical management and patient treatment. Diagn. Cytopathol. 2015;43:432–437. © 2014 Wiley Periodicals, Inc.
Nurr1 blocks the mitogenic effect of FGF‐2 and EGF, inducing olfactory bulb neural stem cells to adopt dopaminergic and dopaminergic‐GABAergic neuronal phenotypes
Authors: Vergaño‐Vera Eva , Díaz‐Guerra Eva , Rodríguez‐Traver Eva , Méndez‐Gómez Héctor R. , Solís Óscar , Pignatelli Jaime , Pickel James , Lee Sang‐Hun , Moratalla Rosario , Vicario‐Abejón Carlos
Published: November 2014

The transcription factor Nurr1 is expressed in the mouse olfactory bulb (OB), although it remains unknown whether it influences the generation of dopaminergic neurons (DA) (DA neurons) in cells isolated from this brain region. We found that expressing Nurr1 in proliferating olfactory bulb stem cells (OBSCs) produces a marked inhibition of cell proliferation and the generation of immature neurons immunoreactive for tyrosine hydroxylase (TH) concomitant with marked upregulations of Th, Dat, Gad, and Fgfr2 transcripts. In long‐term cultures, these cells develop neurochemical and synaptic markers of mature‐like mesencephalic DA neurons, expressing GIRK2, VMAT2, DAT, calretinin, calbindin, synapsin‐I, and SV2. Concurring with the increase in both Th and Gad expression, a subpopulation of induced cells was both TH‐ and GAD‐immunoreactive indicating that they are dopaminergic‐GABAergic neurons. Indeed, these cells could mature to express VGAT, suggesting they can uptake and store GABA in vesicles. Remarkably, the dopamine D1 receptor agonist SKF‐38393 induced c‐Fos in TH+ cells and dopamine release was detected in these cultures under basal and KCl‐evoked conditions. By contrast, cotransducing the Neurogenin2 and Nurr1 transcription factors produced a significant decrease in the number of TH‐positive neurons. Our results indicate that Nurr1 overexpression in OBSCs induces the formation of two populations of mature dopaminergic neurons with features of the ventral mesencephalon or of the OB, capable of responding to functional dopaminergic stimuli and of releasing dopamine. They also suggest that the accumulation of Fgfr2 by Nurr1 in OBSCs may be involved in the generation of DA neurons. © 2014 Wiley Periodicals, Inc. Develop Neurobiol 75: 823–841, 2015
The balance between stress resilience and vulnerability is regulated by corticotropin‐releasing hormone during the critical postnatal period for sensory development
Authors: Cramer Tomer , Kisliouk Tatiana , Yeshurun Shlomo , Meiri Noam
Published: November 2014

Determining whether a stressful event will lead to stress‐resilience or vulnerability depends probably on an adjustable stress response set point, which is most likely effective during postnatal sensory development and involves the regulation of corticotrophin‐releasing hormone (CRH) expression. During the critical period of thermal‐control establishment in 3‐day‐old chicks, heat stress was found to render resilient or sensitized response, depending on the ambient temperature. These two different responses were correlated with the amount of activation of the hypothalamic–pituitary–adrenal (HPA) axis. The expression of CRH mRNA in the hypothalamic paraventricular nucleus was augmented during heat challenge a week after heat conditioning in chicks which were trained to be vulnerable to heat, while it declined in chicks that were trained to be resilient. To study the role of CRH in HPA‐axis plasticity, CRH or Crh‐antisense were intracranially injected into the third ventricle. CRH caused an elevation of both body temperature and plasma corticosterone level, while Crh‐antisense caused an opposite response. Moreover, these effects had long term implications by reversing a week later, heat resilience into vulnerability and vice versa. Chicks that had been injected with CRH followed by exposure to mild heat stress, normally inducing resilience, demonstrated, a week later, an elevation in body temperature, and Crh mRNA level similar to heat vulnerability, while Crh‐antisense injected chicks, which were exposed to harsh temperature, responded in heat resilience. These results demonstrate a potential role for CRH in determining the stress resilience/vulnerability balance. © 2014 Wiley Periodicals, Inc. Develop Neurobiol 75: 842–853, 2015
Regulation of microglial migration, phagocytosis, and neurite outgrowth by HO‐1/CO signaling
Authors: Scheiblich Hannah , Bicker Gerd
Published: November 2014

Clearance of infected and apoptotic neuronal corpses during inflammatory conditions is a fundamental process to create a favorable environment for neuronal recovery. Microglia are the resident immune cells and the predominant phagocytic cells of the CNS, showing a multitude of cellular responses upon activation. Here, we investigated in functional assays how the CO generating enzyme heme oxygenase 1 (HO‐1) influences BV‐2 microglial migration, clearance of debris, and neurite outgrowth of human NT2 neurons. Stimulation of HO‐1 activity attenuated microglial migration in a scratch wound assay, and phagocytosis in a cell culture model of acute inflammation comprising lipopolysaccharide (LPS)‐activated microglia and apoptosis‐induced neurons. Application of a CO donor prevented the production of NO during LPS stimulation, and reduced microglial migration and engulfment of neuronal debris. LPS‐activated microglia inhibited neurite elongation of human neurons without requiring direct cell–cell surface contact. The inhibition of neurite outgrowth was totally reversed by application of exogenous CO or increased internal CO production through supply of the substrate hemin to HO. Our results point towards a vital cytoprotective role of HO‐1/CO signaling after microglial activation. In addition, they support a therapeutic potential of CO releasing chemical agents in the treatment of excessive inflammatory conditions in the CNS. © 2014 Wiley Periodicals, Inc. Develop Neurobiol 75: 854–876, 2015
Epitope‐specific CD4+, but not CD8+, T‐cell responses induced by recombinant influenza A viruses protect against Mycobacterium tuberculosis infection
Authors: Flórido Manuela , Pillay Roman , Gillis Caitlin M. , Xia Yingju , Turner Stephen J. , Triccas James A. , Stambas John , Britton Warwick J.
Published: November 2014

Tuberculosis remains a global health problem, in part due to failure of the currently available vaccine, BCG, to protect adults against pulmonary forms of the disease. We explored the impact of pulmonary delivery of recombinant influenza A viruses (rIAVs) on the induction of Mycobacterium tuberculosis (M. tuberculosis)‐specific CD4+ and CD8+ T‐cell responses and the resultant protection against M. tuberculosis infection in C57BL/6 mice. Intranasal infection with rIAVs expressing a CD4+ T‐cell epitope from the Ag85B protein (PR8.p25) or CD8+ T‐cell epitope from the TB10.4 protein (PR8.TB10.4) generated strong T‐cell responses to the M. tuberculosis‐specific epitopes in the lung that persisted long after the rIAVs were cleared. Infection with PR8.p25 conferred protection against subsequent M. tuberculosis challenge in the lung, and this was associated with increased levels of poly‐functional CD4+ T cells at the time of challenge. By contrast, infection with PR8.TB10.4 did not induce protection despite the presence of IFN‐γ‐producing M. tuberculosis‐specific CD8+ T cells in the lung at the time of challenge and during infection. Therefore, the induction of pulmonary M. tuberculosis epitope‐specific CD4+, but not CD8+ T cells, is essential for protection against acute M. tuberculosis infection in the lung.
The effect of genotype and ripening index on the phenolic profile and fatty acids composition of virgin olive oils from olive breeding programs
Authors: Sánchez de Medina Verónica , Priego‐Capote Feliciano , Luque de Castro María Dolores
Published: November 2014

The combined influence of the genotype and the ripening process on the concentration of phenolic compounds and fatty acids (FAs, both esterified and non‐esterified forms) in virgin olive oils (VOOs) from Arbequina × Picual, Picual × Arbequina and Frantoio × Picual genotypes as well as their genitors has been studied through their profiles obtained by LC–QqTOF and GC–FID, respectively. Statistical multivariate analysis tools allowed finding discrimination of VOOs according to the genotype and the standardized parameter ripening index (RI). Significant phenols and FAs with the highest discrimination capability (p‐value < 0.01) between pairs of genotypes and RI stages were identified to elucidate the main differences in the composition of these two critical families influencing the quality of VOO. Discrimination patterns associated to the two factors with high incidence on the quality of VOO (genotype and RI) were found and quantitative relationship was also found between the RI with the profile of phenols and FAs, and the total phenolic content with the phenol profile, which proves the utility of monitoring both families in VOO as a criterion for selection in plant breeding programs. No correlation was found between the total phenolic content and FAs composition.

Practical applications: Olive breeding programs are based on the monitoring of agronomical and/or quality parameters of the VOO. Phenols and FAs are two of the main families with influence on the quality of VOOs.

“The combined influence of the genotype and the ripening process on the concentration of phenolic compounds and fatty acids in virgin olive oils has been studied. Phenolic profiles were obtained by LC–QTOF MS/MS while fatty acids were analyzed by GC–FID. Statistical multivariate analysis tools were applied to identify the main variability sources”.
The Frondosins: An Unusual Synthetic and Stereochemical Journey
Authors: VanHeyst Michael D. , Wright Dennis L.
Published: November 2014

Isolated from the marine sponge Dysidea frondosa, the frondosin family of meroterpenoid natural products were shown to be antagonists of the binding of the cytokine interleukin‐8 to its receptor. With implications of interleukin‐8 management being associated with a wide range of acute and chronic inflammatory disorders, as well as tumor progression and/or metathesis, there have been a multitude of syntheses of these natural products in the hopes of developinging new pharmacological agents. However, assignment of the absolute configurations of these natural products became unclear, because the first two syntheses of frondosin B, by Danishefsky and by Trauner, produced conflicting assignments for the single stereogenic center at C8. Here we describe the initial stereochemical mystery surrounding the Danishefsky and Trauner syntheses and provide evidence through ensuing syntheses of frondosins B and A that resolve this issue. These subsequent asymmetric syntheses have established that (1) the natural product occurs as the R enantiomer, and (2) a late‐stage stereochemical inversion occurred during the Trauner and Wright syntheses of frondosin B.
Environmental and Economic Assessment of Leak and Loss Audits at Natural Gas Compressor and Storage Facilities
Authors: Johnson Derek , Covington April , Clark Nigel
Published: November 2014

According to the United States (US) Energy Information Administration (EIA), the annual US natural gas consumption is forecast to grow from 25.6 trillion cubic feet (TCF) in 2012 to 31.6 TCF in 2040 (1 CF≈28.3 L). The main component of natural gas is methane, a potent greenhouse gas (GHG). As the natural gas supply chain grows, there is increased scrutiny over leaks and losses that occur during the multiple stages from development to end users. West Virginia University′s (WVU) Center for Alternative Fuels, Engines, and Emissions conducted leak and loss audits at five natural gas compressor and storage facilities in the Barnett Shale region of Texas. We have reported elsewhere on the site‐specific total leak and loss rates.11–13 This article provides an environmental and economic assessment of the total methane (natural gas) losses at these facilities. Other studies report the methane emissions in terms of tons per year, whereas this paper examines the environmental impact of these emissions through an equivalent CO2 emissions rate using multiple global warming potentials. This paper also examines the lost revenue from these leaks and the overall social cost of carbon (SCC) that could be assessed to these facilities under a proposed carbon tax. The methane leaks and losses from these sites result in CO2 equivalent emissions of over 70 000 and 24 000 metric tons annually, using a 20‐year and 100‐year global warming potentials (GWPs), respectively. Using a SCC of $ 37 per metric ton, this would result in annual costs of $ 2.6 million and $ 915 000 for these sites based on the respective GWPs.
Dynamic Latent Class Model Averaging for Online Prediction
Authors: Yang Hongxia , Hosking Jonathan R. M. , Amemiya Yasuo
Published: November 2014

We consider the problem of online prediction when it is uncertain what the best prediction model to use is. We develop a method called dynamic latent class model averaging, which combines a state‐space model for the parameters of each of the candidate models of the system with a Markov chain model for the best model. We propose a polychotomous regression model for the transition weights to assume that the probability of a change in time depends on the past through the values of the most recent time periods and spatial correlation among the regions. The evolution of the parameters in each submodel is defined by exponential forgetting. This structure allows the ‘correct’ model to vary over both time and regions. In contrast to existing methods, the proposed model naturally incorporates clustering and prediction analysis in a single unified framework. We develop an efficient Gibbs algorithm for computation, and we demonstrate the value of our framework on simulated experiments and on a real‐world problem: forecasting IBM's corporate revenue. Copyright © 2014 John Wiley & Sons, Ltd.
Realized Volatility Forecast of Stock Index Under Structural Breaks
Authors: Yang Ke , Chen Langnan , Tian Fengping
Published: November 2014

We investigate the realized volatility forecast of stock indices under the structural breaks. We utilize a pure multiple mean break model to identify the possibility of structural breaks in the daily realized volatility series by employing the intraday high‐frequency data of the Shanghai Stock Exchange Composite Index and the five sectoral stock indices in Chinese stock markets for the period 4 January 2000 to 30 December 2011. We then conduct both in‐sample tests and out‐of‐sample forecasts to examine the effects of structural breaks on the performance of ARFIMAX‐FIGARCH models for the realized volatility forecast by utilizing a variety of estimation window sizes designed to accommodate potential structural breaks. The results of the in‐sample tests show that there are multiple breaks in all realized volatility series. The results of the out‐of‐sample point forecasts indicate that the combination forecasts with time‐varying weights across individual forecast models estimated with different estimation windows perform well. In particular, nonlinear combination forecasts with the weights chosen based on a non‐parametric kernel regression and linear combination forecasts with the weights chosen based on the non‐negative restricted least squares and Schwarz information criterion appear to be the most accurate methods in point forecasting for realized volatility under structural breaks. We also conduct an interval forecast of the realized volatility for the combination approaches, and find that the interval forecast for nonlinear combination approaches with the weights chosen according to a non‐parametric kernel regression performs best among the competing models. Copyright © 2014 John Wiley & Sons, Ltd.
Fabrication and Power Densities of Anode‐Supported Solid Oxide Fuel Cells with Different Ni‐YSZ Anode Functional Layer Thicknesses
Authors: Kagomiya I. , Kaneko S. , Kakimoto K. , Park K. , Cho K.H.
Published: November 2014

We investigated an appropriate preparation condition for anode‐supported SOFCs: (La,Sr)MnO3/cathode functional layer/YSZ/Ni‐YSZ were fabricated with and without a Ni‐YSZ anode functional layer (AFL) via the tape‐casting method, where the AFL thicknesses were controlled from approximately 20 to 80 μm. The warpage depended on the co‐sintering temperature of the electrolyte/AFL/anode‐support half‐cells, indicating that similar shrinkage of the electrolyte/AFL/anode support is significant for lower warpages. The electrical properties of SOFCs with AFLs were compared to those of SOFCs without AFLs. In this regard, the use of an AFL decreased the ohmic and activation polarization resistances due to both the decrease in contact resistance between the electrolyte and the AFL and the increase in three‐phase boundaries. However, the polarization diffusion increased when an AFL was employed, because AFL layers are denser than the anode support. The maximum power densities of samples with AFL were higher than those of SOFCs without AFLs, indicating that the decrease in both ohmic and activation‐polarization resistances is more significant for improving the power densities, as compared to the concentration polarization resistance.