bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flow Manifold Optimization for a Uniform Velocity Distribution in a Laminated Microreactor with Micro‐Pin‐Fin Arrays
Authors: Qian Miao , Mei Deqing , Yao Zhehe , Liu Binhong , Lou Xinyang , Chen Zichen 
Published: June 2014

AbstractVelocity uniformity in reaction channels has a significant effect on the performance of laminated microreactors with micro‐pin‐fin arrays (MPFAR) for hydrogen production. The hydrogen production efficiency can be improved by optimizing the structure of flow manifolds. The relationship between the flow manifold structure and the velocity distribution in the reaction channel with MPFAR is established by an equivalent electrical resistance network model validated via simulation. The effects of the flow manifold structure on the velocity distribution are investigated. The results show that the velocity distribution can be improved by increasing the y‐direction coordinate Ypi of the flow manifold inlet tube. The flow manifold structure is optimized for better velocity distribution in reaction channels with different MPFAR widths.
A Model to Characterize and Predict Fugitive Emissions from Flange Joints
Authors: Pansegrau Lukas , Schembecker Gerhard , Bramsiepe Christian 
Published: June 2014

AbstractThe new model describing the gaseous transport through graphite gaskets is based on the assumption of a flow in the transition regime through nano‐scale capillaries, using the Maxwellian wall‐slip boundary condition for rarefied gases. Together with an earlier published model describing the liquid transport in graphite gaskets, it enables the characterization of fugitive emissions of volatile organic compounds from fluid‐charged flange joints in chemical and petrochemical plants as a function of medium properties, pipe pressure, and gasket stress. Additionally, combination of the models allows predicting the emission rates of gases by experiments with liquids as the emitting fluid. Finally, recommendations are made to improve the gaskets with respect to their sealing performance towards gases.
Increasing the Equilibrium Yield of Oxidative Dehydrogenation with CO2 by Secondary Reactions
Authors: Müller Karsten , Baumgärtner Andrea , Mokrushina Liudmila , Arlt Wolfgang 
Published: June 2014

AbstractOxidative dehydrogenation with carbon dioxide as an oxidant at low temperatures is strongly limited by its thermodynamic equilibrium. It is be shown that the equilibrium yield of the desired olefin can significantly be increased utilizing side reactions. This does not necessarily require the addition of another reactant, since this reactant can be formed in situ from the starting alkane. This effect allows for a decrease of the reaction temperature as well as the overall heat demand of the reaction. As a consequence, the exergy demand of the reaction system is reduced substantially.
Influence of Flow Conditions in High‐Pressure Orifices on Droplet Disruption of Oil‐in‐Water Emulsions
Authors: Kelemen Katharina , Schuch Anna C. , Schuchmann Heike P. 
Published: June 2014

AbstractFlow conditions in and behind high‐pressure orifices are described by a characteristic correlation between discharge coefficient and Reynolds number. The use of a pressure vessel and variations in viscosity allowed for non‐pulsating flow conditions from laminar to turbulent flow. Emulsions were homogenized under each condition. A considerable difference was observed in the final droplet size distribution depending on laminar, transitional, and turbulent flow. When the flow was pulsating as found when applying a plungers pump, transition of the flow from laminar to turbulence was more difficult to detect. Emulsions homogenized under these conditions indicated broader droplet size distributions. The Sauter mean diameter, however, was not affected by the pulsating flow.
A Domino Approach to the Enantioselective Total Syntheses of Blennolide C and Gonytolide C
Authors: Tietze Lutz F. , Jackenkroll Stefan , Hierold Judith , Ma Ling , Waldecker Bernd 
Published: June 2014

AbstractThe first enantioselective total syntheses of the tetrahydroxanthenone (−)‐blennolide C (ent‐4) and related γ‐lactonyl chromanone (−)‐gonytolide C (ent‐3) are reported. Key to the syntheses is an enantioselective domino‐Wacker/carbonylation/methoxylation reaction to set up the stereocentre at C‐4a. Various chiral BOXAX ligands were investigated, including novel (S,S)‐iBu‐BOXAX, and allowed access to chromane 8 in an excellent enantioselectivity of 99 %. The second stereocentre at C‐4 was established employing a diastereoselective Sharpless dihydroxylation. An extensive survey of (DHQ)‐ and (DHQD)‐based ligands enabled the preparation of both the anti‐isomer 14 a and the syn‐isomer 14 b in very good to reasonable selectivities of 13.7:1 and 1:3.7, respectively. While 14 a was further converted to ent‐3 and ent‐4, 14 b was elaborated to syn‐acid 25 and 2′‐epi‐gonytolide C 28.
Dynamic Complexation of Copper(I) Chloride by Carbene‐Stabilized Disilicon
Authors: Chen Mingwei , Wang Yuzhong , Xie Yaoming , Wei Pingrong , Gilliard Robert J. , Schwartz Nichole A. , Schaefer Henry F. , Schleyer Paul von R. , Robinson Gregory H. 
Published: June 2014

AbstractReaction of N‐heterocyclic‐carbene (NHC)‐stabilized disilicon (1) with CuCl gave a carbene‐stabilized disilicon–copper(I) chloride complex (2). The nature of the structure and bonding in 2 has been investigated by crystallographic, spectroscopic, and computational methods. The dynamic complexation behavior of 2 was experimentally explored by variable‐temperature NMR analysis.
Persistent homology analysis of protein structure, flexibility, and folding
Authors: Xia Kelin , Wei Guo‐Wei 
Published: June 2014

SUMMARYProteins are the most important biomolecules for living organisms. The understanding of protein structure, function, dynamics, and transport is one of the most challenging tasks in biological science. In the present work, persistent homology is, for the first time, introduced for extracting molecular topological fingerprints (MTFs) based on the persistence of molecular topological invariants. MTFs are utilized for protein characterization, identification, and classification. The method of slicing is proposed to track the geometric origin of protein topological invariants. Both all‐atom and coarse‐grained representations of MTFs are constructed. A new cutoff‐like filtration is proposed to shed light on the optimal cutoff distance in elastic network models. On the basis of the correlation between protein compactness, rigidity, and connectivity, we propose an accumulated bar length generated from persistent topological invariants for the quantitative modeling of protein flexibility. To this end, a correlation matrix‐based filtration is developed. This approach gives rise to an accurate prediction of the optimal characteristic distance used in protein B‐factor analysis. Finally, MTFs are employed to characterize protein topological evolution during protein folding and quantitatively predict the protein folding stability. An excellent consistence between our persistent homology prediction and molecular dynamics simulation is found. This work reveals the topology–function relationship of proteins. Copyright © 2014 John Wiley & Sons, Ltd.
Secure random number generation in wireless sensor networks
Authors: Lo Re Giuseppe , Milazzo Fabrizio , Ortolani Marco 
Published: June 2014

SummaryThe increasing adoption of wireless sensor networks as a flexible and inexpensive tool for the most diverse applications, ranging from environmental monitoring to home automation, has raised more and more attention to the issues related to the design of specifically customized security mechanisms. The scarcity of computational, storage, and bandwidth resources cannot definitely be disregarded in such context, and this makes the implementation of security algorithms particularly challenging. This paper proposes a security framework for the generation of true random numbers, which are paramount as the core building block for many security algorithms; the intrinsic nature of wireless sensor nodes and their capability of reliably providing measurements of environmental quantities make them natural candidates as true random number generators. In order to provide robustness to common attacks, we additionally devised a protocol aimed at obscuring the actual source of data, by making nodes cooperate with their neighbors. Furthermore, we describe an enhanced version of our framework consisting in an optimization for use in the context of resource‐constrained systems. Copyright © 2014 John Wiley & Sons, Ltd.
Rules of Boron–Nitrogen Doping in Defect Graphene Sheets: A First‐Principles Investigation of Band‐Gap Tuning and Oxygen Reduction Reaction Catalysis Capabilities
Authors: Sen Dipayan , Thapa Ranjit , Chattopadhyay Kalyan Kumar 
Published: June 2014

AbstractIntroduction of defects and nitrogen doping are two of the most pursued methods to tailor the properties of graphene for better suitability to applications such as catalysis and energy conversion. Doping nitrogen atoms at defect sites of graphene and codoping them along with boron atoms can further increase the efficiency of such systems due to better stability of nitrogen at defect sites and stabilization provided by BN bonding. Systematic exploration of the possible doping/codoping configurations reflecting defect regions of graphene presents a prevalent doping site for nitrogen‐rich BN clusters and they are also highly suitable for modulating (0.2–0.9 eV) the band gap of defect graphene. Such codoped systems perform significantly better than the platinum surface, undoped defect graphene, and the single nitrogen or boron atom doped defect graphene system for dioxygen adsorption. Significant stretching of the OO bond indicates a lowering of the bond breakage barrier, which is advantageous for applications in the oxygen reduction reaction.
In Vivo Processing of Ceria Nanoparticles inside Liver: Impact on Free‐Radical Scavenging Activity and Oxidative Stress
Authors: Graham Uschi M. , Tseng Michael T. , Jasinski Jacek B. , Yokel Robert A. , Unrine Jason M. , Davis Burtron H. , Dozier Alan K. , Hardas Sarita S. , Sultana Rukhsana , Grulke Eric A. , Butterfield D. Allan 
Published: June 2014

AbstractThe cytotoxicity of ceria ultimately lies in its electronic structure, which is defined by the crystal structure, composition, and size. Despite previous studies focused on ceria uptake, distribution, biopersistance, and cellular effects, little is known about its chemical and structural stability and solubility once sequestered inside the liver. Mechanisms will be presented that elucidate the in vivo transformation in the liver. In vivo processed ceria reveals a particle‐size effect towards the formation of ultrafines, which represent a second generation of ceria. A measurable change in the valence reduction of the second‐generation ceria can be linked to an increased free‐radical scavenging potential. The in vivo processing of the ceria nanoparticles in the liver occurs in temporal relation to the brain cellular and protein clearance responses that stem from the ceria uptake. This information is critical to establish a possible link between cellular processes and the observed in vivo transformation of ceria. The temporal linkage between the reversal of the pro‐oxidant effect (brain) and ceria transformation (liver) suggests a cause–effect relationship.
Electrocatalytic Oxidation of Cellulose at a Gold Electrode
Authors: Sugano Yasuhito , Latonen Rose‐Marie , Akieh‐Pirkanniemi Marceline , Bobacka Johan , Ivaska Ari 
Published: June 2014

AbstractThe electrochemical properties of cellulose dissolved in NaOH solution at a Au surface were investigated by cyclic voltammetry, FTIR spectroscopy, the electrochemical quartz crystal microbalance technique, and electrochemical impedance spectroscopy. The reaction products were characterized by SEM, TEM, and FTIR and NMR spectroscopy. The results imply that cellulose is irreversibly oxidized. Adsorption and desorption of hydroxide ions at the Au surface during potential cycling have an important catalytic role in the reaction (e.g., approach of cellulose to the electrode surface, electron transfer, adsorption/desorption of the reaction species at the electrode surface). Moreover, two types of cellulose derivatives were obtained as products. One is a water‐soluble cellulose derivative in which some hydroxyl groups are oxidized to carboxylic groups. The other derivative is a water‐insoluble hybrid material composed of cellulose and Au nanoparticles (≈4 nm). Furthermore, a reaction scheme of the electrocatalytic oxidation of cellulose at a gold electrode in a basic medium is proposed.
Characterizing peatland carbon balance estimates using freely available Landsat ETM+ data
Authors: Crichton K. A. , Anderson K. , Bennie J. J. , Milton E. J. 
Published: June 2014

AbstractWe demonstrate the potential of using freely available satellite data from the Landsat ETM+ sensor for generating carbon balance estimates for lowland peatlands. We used a lowland ombrotrophic peatland in the UK as our test site representing a range of peatland conditions. A literature survey was undertaken to identify the simplest classification schema that could be used to distinguish ecohydrological classes for carbon sequestration on the peatland surface. These were defined as: active raised bog, Eriophorum‐dominated bog, milled unvegetated peat and drained or degraded bog, with bracken and Carr woodland to define the bog edges. A maximum likelihood classifier (MLC) was used to map the spatial distribution of the six classes on the peatland surface. A Landsat ETM+ band‐5 derived brightness‐texture layer created using geostatistical methods greatly improved classification accuracies. The results showed the best accuracy of the MLC, when compared to finer scale methods, with Landsat ETM+ bands alone was 74%, which increased to 93% when including the brightness‐texture layer. An estimate of carbon sequestration status of the site was performed that showed good agreement with the results of a finer‐scale‐based estimate. The coarse‐scale map estimating −12 000 kg carbon and fine scale map estimating +23 000 kg carbon per annum. We conclude that with further development of our tool, if textural measures are used alongside optical data in MLC, it is possible to achieve good quality estimates of carbon balance status for peatland landscapes. This represents a potentially powerful operational toolkit for land managers and policy makers who require spatially distributed information on carbon storage and release for carbon pricing and effective land management. Copyright © 2014 John Wiley & Sons, Ltd.
Palladium‐Catalyzed α‐Arylation of Carboxylic Acid Derivatives with Grignard Reagent
Authors: Tanaka Daiki , Tanaka Shota , Mori Atsunori 
Published: June 2014

AbstractThe reaction of arylacetic acid with aryl halides in the presence of a palladium(0) catalyst proceeds with a Grignard reagent (2 equiv.) to afford diarylated acetic acids. Deprotonation was confirmed by treatment with allyl bromide, which revealed that the use of EtMgCl or tBuMgCl at room temperature to 60 °C resulted in complete deprotonation. After deprotonation of (4‐methoxyphenyl)acetic acid under such conditions, the resulting mixture was treated with 4‐methoxybromobenzene in the presence of Pd(tBu3P)2 (2 mol‐%) as a catalyst to give bis(4‐methoxyphenyl)acetic acid in 86 % yield. The reaction with several aryl halides under similar conditions gave the corresponding diarylacetic acids.
In situ and laboratory toxicity of coalbed natural gas produced waters with elevated sodium bicarbonate
Authors: Farag Aïda M. , Harper David D. , Skaar Don 
Published: June 2014

Abstract

Some tributaries in the Powder River Structural Basin, USA, were historically ephemeral, but now contain water year round as a result of discharge of coalbed natural gas (CBNG)-produced waters. This presented the opportunity to study field sites with 100% effluent water with elevated concentrations of sodium bicarbonate. In situ experiments, static renewal experiments performed simultaneously with in situ experiments, and static renewal experiments performed with site water in the laboratory demonstrated that CBNG-produced water reduces survival of fathead minnow (Pimephales promelas) and pallid sturgeon (Scaphirhynchus albus). Age affected survival of fathead minnow, where fish 2 d posthatch (dph) were more sensitive than 6 dph fish, but pallid sturgeon survival was adversely affected at both 4 and 6 dph. This may have implications for acute assays that allow for the use of fish up to 14 dph. The survival of early lifestage fish is reduced significantly in the field when concentrations of NaHCO3 rise to more than 1500 mg/L (also expressed as &gt;1245 mg HCO3−/L). Treatment with the Higgin's Loop technology and dilution of untreated water increased survival in the laboratory. The mixing zones of the 3 outfalls studied ranged from approximately 800 m to 1200 m below the confluence. These experiments addressed the acute toxicity of effluent waters but did not address issues related to the volumes of water that may be added to the watershed. Environ Toxicol Chem 2014; 33:2086–2093. Published 2014 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.
Study of Photoluminescence Excitation Spectra of Tris(8‐hydroxyquinoline)aluminum(III) (Alq3) in Solutions and Films
Authors: Wang Zhoulu , Tsuboi Taiju , Liu Xiang , Huang Wei 
Published: June 2014

AbstractAbsorption, photoluminescence, and photoluminescence excitation (PLE) spectra have been investigated for tris(8‐hydroxyquinoline)aluminum(III) (Alq3) in solution at various Alq3 concentrations and in doped and neat films. The redshifted PLE spectra, with respect to the absorption spectra, are obtained, together with a dip located near the absorption band peak. The dip becomes deeper with increasing concentration. It is found that the unusual PLE spectra are caused by the penetration depth effect, not by previously suggested microcrystallites of Alq3.
Change of Luminescence Properties of Europium Ions Captured by Mixed‐Ligand Silver Nanoparticles
Authors: Cho Eun Seon , Yokoyama Takahiro , Ertem Elif , Stellacci Francesco 
Published: June 2014

AbstractWe present herein silver nanoparticles about 4 nm in diameter coated with a binary mixture of 1‐octanethiol and 2‐(2‐{2‐[(6‐mercaptohexyl)oxy]ethoxy}ethoxy)ethanol. These particles show an affinity towards optically active Eu3+ ions. The effect of the nanoparticle on the characteristic emission peaks of Eu3+ is investigated. We use the variation in emission spectra of the ion to establish its binding to the nanoparticles.
MCP‐1 as a Potential Target to Inhibit the Bone Invasion by Oral Squamous Cell Carcinoma
Authors: Quan Jingjing , Morrison Nigel A. , Johnson Newell W. , Gao Jin 
Published: June 2014

AbstractBone invasion is a common complication of oral squamous cell carcinoma (OSCC), and this study sought to explore whether suppressed expression of monocyte chemotactic protein‐1 (MCP‐1) can be used to inhibit the bone invasion by OSCC. Strong staining of MCP‐1 protein was observed from 10 archival blocks of OSCC by immunohistochemistry (IHC). Real‐time PCR showed MCP‐1 mRNA was highly expressed by OSCC cell lines (SCC25, HN5, and Tca8113), and SCC25 cells had the highest expression. An expression construct of a dominant negative variant of MCP‐1 with 7 amino acids truncated (7ND), in the vector pcDNA was used to transfect SCC25 cells, and resultant stabilized SCC25 cells (SCC25‐7ND) were generated by antibiotic selection. 10% conditioned media (CM, supernatant) of SCC25‐7ND cells efficiently inhibited the formation of human osteoclasts grown from CD14+ monocyte subpopulation, comparing with 10% CM of SCC25 cells. Further, cells of SCC25 or SCC25‐7ND were injected onto the surface of calvariae of nude mice to establish an animal model of bone invasion by OSCC. H&E staining showed well‐differentiated OSCC was formed in both groups, tumour cells invading the bone while osteoclasts locating in typical resorption lacunae. TRAP staining indicated significantly fewer osteoclasts were found in calvariae with cells of SCC25‐7ND in comparison to cells of SCC25. These data demonstrate the relevance of MCP‐1 with research on bone invasion by OSCC, and suggest the potential value of MCP‐1 as a target to inhibit this common complication. J. Cell. Biochem. 115: 1787–1798, 2014. © 2014 Wiley Periodicals, Inc.
Movement Disorders in Autosomal Dominant Cerebellar Ataxias: A Systematic Review
Authors: Rossi Malco , Perez‐Lloret Santiago , Cerquetti Daniel , Merello Marcelo 
Published: June 2014

AbstractAutosomal dominant cerebellar ataxias (ADCAs) are clinically heterogeneous disorders classified according to genetic subtype and collectively known as SCAs. In a few SCAs, movement disorders can be the most frequent extracerebellar sign. The aim of this article is to perform a systematic review of movement disorders frequency and characteristics in ADCAs. This work consisted of a structured search of electronic databases up to January 2013. Publications containing descriptions of ADCA clinical features written in several languages were selected initially based on title and abstract screening, followed by full‐text reading of potentially relevant publications. Clinical findings and demographic data on genetically confirmed patients were extracted. Analysis of individual patient data from subjects with movement disorders was performed using the chi‐square test and logistic regression. One thousand and sixty‐six publications reviewing 12,151 patients from 30 different SCAs were analyzed. Individual data were available from 755 patients with at least one type of movement disorder during overall disease course. Of 422 patients in whom onset symptom data were available, one third referred a movement disorder as the initial symptom. During overall disease course, parkinsonism was common in many SCA subtypes, frequently described in the absence of ataxia and characterized as responding to dopaminergic medications. Motor complications developed occasionally in some patients as did nigrostriatal imaging alterations. Other frequent features were dystonia, chorea, and myoclonus. Rare conditions, such as akathisia, paroxysmal nonkinesigenic dyskinesia, or stiff person‐like syndrome, were also reported. ADCA descriptions included a full range of movement disorders. Aside from postural or intention tremor, dopamine‐responsive parkinsonism and dystonia were the most common.