bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Annealing and Interfacial Roughness on the Performance of Bilayer Donor/Acceptor Polymer Photovoltaic Devices
Authors: Yan Hongping , Swaraj Sufal , Wang Cheng , Hwang Inchan , Greenham Neil C. , Groves Chris , Ade Harald , McNeill Christopher R.
Published: September 2010

Through controlled annealing of planar heterojunction (bilayer) devices based on the polyfluorene copolymers poly(9,9‐dioctylfluorene‐co‐bis(N,N′‐(4,butylphenyl))bis(N,N′‐phenyl‐1,4‐phenylene)diamine) (PFB) and poly(9,9‐dioctylfluorene‐co‐benzothiadiazole) (F8BT) we study the influence of interface roughness on the generation and separation of electron–hole pairs at the donor/acceptor interface. Interface structure is independently characterized by resonant soft X‐ray reflectivity with the interfacial width of the PFB/F8BT heterojunction observed to systematically increase with annealing temperature from 1.6 nm for unannealed films to 16 nm with annealing at 200 °C for ten minutes. Photoluminescence quenching measurements confirm the increase in interface area by the three‐fold increase in the number of excitons dissociated. Under short‐circuit conditions, however, unannealed devices with the sharpest interface are found to give the best device performance, despite the increase in interfacial area (and hence the number of excitons dissociated) in annealed devices. The decrease in device efficiency with annealing is attributed to decreased interfacial charge separation efficiency, partly due to a decrease in the bulk mobility of the constituent materials upon annealing but also (and significantly) due to the increased interface roughness. We present results of Monte Carlo simulations that demonstrate that increased interface roughness leads to lower charge separation efficiency, and are able to reproduce the experimental current‐voltage curves taking both increased interfacial roughness and decreased carrier mobility into account. Our results show that organic photovoltaic performance can be sensitive to interfacial order, and heterojunction sharpness should be considered a requirement for high performance devices.
Stability and optimum polymerized condition of polysiloxane–polyacrylate core/shell polymer
Authors: Ge Chengyue , Wu Yumin , Xu Jun
Published: September 2010

The stable emulsion of core/shell latex with little coagulum (no more than 0.5% in quality relative to total monomers) has been prepared at low temperature with potassium‐persulfate (KPS), sodium formaldehyde sulfoxylate (SFS), and 2,2′‐azobis(2‐(2‐imidazolin‐2‐yl)propane)dihydrochloride (VA‐044) as composite initiators by staged emulsion polymerization. Reactive surfactants were used to significantly improve the stability of emulsion. More interestingly, reverse core/shell structure was investigated when the organic silicon was added in the late period of polymerization. The effects of the emulsifier, initiators, dosage of organic silicon, and monomer's content on conversion and graft efficiency were studied in detail. Moreover, the stability of emulsion was investigated by the values of zeta potential (ζ) and coagulum. More importantly, the thermal performance and stability of PSI/PA composite latex was studied by the glass transition temperature (Tg). The results showed that there are appropriate values for all factors to obtain high conversion, graft efficiency, and excellent stability: The dosage of surfactant was about 0.44 g, the dosage of VA‐044 was about 1000 mg kg−1, the dosage of organic silicon was about 15%, and the monomer's content was about 30%. In addition, the introduction of organic silicon improved the Tg. © 2010 Wiley Periodicals, Inc. Adv Polym Techn 29:161–172, 2010; View this article online at wileyonlinelibrary. DOI 10.1002/adv.20182
On the peel behavior of polymer coating–steel system: Effect of hygrothermal aging
Authors: Guermazi N. , Haddar N. , Elleuch K. , Ayedi H. F.
Published: September 2010

This paper describes the development and application of a new peel protocols for the evaluation of adhesion of a flexible‐to‐rigid assembly. The developed apparatus allows simulating and predicting the delamination of the polymer coating from the steel substrate. The effect of certain test parameters such as a peel angle and peel speed was discussed. The durability of the retained assembly was equally investigated by considering an accelerated hygrothermal aging. The interfacial damages after conditioning and peel tests were characterized. Using two peeling angles of 90° and 180°, no significant difference was observed in terms of peel responses. The interface behavior seems to be not sensitive to the peel angle. However, an increase in the peel rate induces an increase in the peel strength. The characterization of the interface exhibits two mechanisms: The delamination process of the polymer coating is characterized by cohesive and mixed rupture, respectively, at low and high peel rates. Studying the effects of aging and coating defects on the interface behavior displays a continuous loss of adhesion of the polymer coating especially when it presents physical defects. © 2010 Wiley Periodicals, Inc. Adv Polym Techn 29:185–196, 2010; View this article online at wileyonlinelibrary. DOI 10.1002/adv.20188
An experimental study of single‐screw extrusion of HDPE–wood composites
Authors: Xiao Karen , Tzoganakis Costas
Published: September 2010

Single‐screw extrusion experiments were carried out to study the extrusion characteristics of HDPE–wood composites. Three screw geometries (A, B, and C) were used, and the effects of screw speed on output, melting, and pressure profile were studied. Screw A had a much higher compression ratio than screws B and C, which directly affected the melting behavior of the polymers. Screws B and C had the same compression ratio; however, screw C had the same metering capacity as screw A. Therefore, by comparing screws B and C, the effect of feed depth on the solid conveying capacity was investigated. It was found that while screw B had higher outputs than both screws A and C as expected, screw C had a much lower output than screw A for highly filled resins even though they had the same metering capacity. For HDPE, screws A and C showed the same output as expected. Further examinations of the pressure profiles and melting profiles from screw extraction experiments confirmed that screw C showed a severely starved solids conveying capacity for wood‐filled resins, which limited the total outputs. Comparing the outputs and pressure generations between theoretical predictions and actual experimental results, it was evident that due to the inaccurate assumption of fully filled channels common in single screw extrusion, both outputs and pressure generations in the extruders were overpredicted. © 2010 Wiley Periodicals, Inc. Adv Polym Techn 29:197–218, 2010; View this article online at wileyonlinelibrary. DOI 10.1002/adv.20190
ADIPOQ SNP45 associated with lean body mass in physically active normal weight adolescent girls
Authors: Passariello Catherine L. , Gruodytė Rita , Hiio Kelli , Mäestu Jarek , Jürimäe Jaak , Saar Melli , Cicchella Antonio , Stefanelli Claudio , Jürimäe Toivo
Published: September 2010

Recently, two single nucleotide polymorphisms at position 45 and 276 on the adiponectin gene (ADIPOQ) have been recognized as determinants of total adiponectin levels, insulin resistance, and risk for diabetes in various obese populations.

Objectives

The aim of this study was to determine whether these two polymorphisms are indeed determinants in the development of metabolic disorders or whether they are secondary to other confounding factors.

Methods

To do so, we have selected 170 physically active adolescent girls (mean age, 14.03 ± 1.5 years and mean body mass index, 19.98 ± 2.5 kg/m2) devoid of any metabolic diseases or confounding factors, to better attribute any findings to genotype effects. Concentration of adiponectin, insulin, and glucose were determined from blood samples with appropriate kits. Body fat parameters were evaluated with dual‐energy X‐ray absorptiometry, and genotype was analyzed with DNA extracted from whole blood samples followed by polymerase chain reaction and electrophoresis to separate alleles.

Results

Neither single nucleotide polymorphism +45T/G nor +276G/T was related to homeostasis model assessment index or adiponectin levels; however, the presence of the G allele on site 45 favored a significant decrease in lean body mass compared with those who were T homozygous (TG:36.90/TT:41.07 kg, P < 0.05).

Conclusions

Results suggest that the reported increase in the risk of diabetes in subjects that were G allele carriers at site 45 in obese populations compared with normal‐weight populations can be linked instead to a change in muscle mass or the muscle itself present in this genotype group. Am. J. Hum. Biol., 2010. © 2010 Wiley‐Liss, Inc.
Poly(ether ether ketone) composites reinforced by short carbon fibers and zirconium dioxide nanoparticles: Mechanical properties and sliding wear behavior with water lubrication
Authors: Zhong Y. J. , Xie G. Y. , Sui G. X. , Yang R.
Published: September 2010

Poly(ether ether ketone) (PEEK) composites reinforced by short carbon fibers (SCFs) and nanoscale zirconium dioxide (ZrO2) particles were prepared by twin‐screw extrusion compounding and subsequently injection molding. The effects of SCFs and ZrO2 nanoparticles on the mechanical properties and wear behavior of PEEK composites with water lubrication were investigated. The mechanical properties of the composites were dramatically enhanced by the incorporation of SCFs. The addition of nano‐ZrO2 also promoted efficient improvements in the stiffness and hardness but degraded the impact strength. The compounding of the two fillers remarkably improved the wear resistance of the composites under aqueous conditions and especially under high pressures. The excellent wear resistance of the PEEK/carbon fiber (CF)/ZrO2 composites under aqueous conditions was revealed to be due to a synergy effect between the ZrO2 nanoparticles and CFs. The SCFs carried the majority of the load during a sliding process and prevented severe wear of the matrix. The incorporation of nano‐ZrO2 efficiently inhibited CF failure by reducing the stress concentration on the CF interface and the shear stress between two sliding surfaces via a positive rolling effect of the nanoparticles. Furthermore, a linear correlation was found between the wear rate and some mechanical properties of the composites. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Rapid homogeneous esterification of cellulose extracted from Posidonia induced by microwave irradiation
Authors: Chadlia Aguir , Farouk M'Henni Mohamed
Published: September 2010

In this article, we report on the synthesis of cellulose esters by the reaction of cellulose and some cyclic anhydrides, such as succinic, maleic, and phthalic anhydrides. For this, an esterification method was finalized. Indeed, cellulose extracted from Posidonia biomass was first solubilized in the solvent system lithium chloride (LiCl)/N,N‐dimethylacetamide and then esterified by cyclic anhydride in the presence of catalysts such as N,N‐dimethyl‐4‐aminopyridine, tripropylamine, tributylamine, and calcium carbonate. This method was fast and reproducible with the LiCl system as a solvent and with an efficient activation by controlled microwave power. In this way, the reaction time was reduced from several hours to just a few minutes. The reaction products were characterized by IR and solid‐state cross‐polarization/magic angle spinning 13C‐NMR spectroscopy. The degree of substitution (DS) and the grafted ester group content of the different products were obtained by alkali saponification followed by titration of the excess alkali. Two activation methods were compared, and the results show that the application of classical heating gave less successful results than those obtained by microwave activation. Indeed, with microwave activation, a higher DS (2.25) was obtained after 10 min. However, with classical heating, a value of DS equal to 1.2 was obtained after 12 h. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Separation of ethanol from ethanol/water mixtures by pervaporation with silicone rubber membranes: Effect of silicone rubbers
Authors: Han Xiaolong , Wang Lei , Li Jiding , Zhan Xia , Chen Jian , Yang Jichu
Published: September 2010

In this study, poly(dimethyl siloxane) (PDMS)/poly(vinylidene fluoride) (PVDF), poly(phenyl methyl siloxane) (PPMS)/PVDF, poly(ethoxy methyl siloxane) (PEOMS)/PVDF, and poly(trifluropropyl methyl siloxane) (PTFMS)/PVDF composite membranes were prepared. The different functional compositions of these membranes were characterized by Fourier transform infrared spectroscopy. The surfaces and sections of these membranes were investigated by scanning electron microscopy. The hydrophobicity at the membrane surface was assessed with contact angle measurement. Swelling experiments were carried out to investigate the swelling behavior of these membranes. The composite membranes prepared in this study were used in the pervaporation separation of ethanol/water mixtures, and their separation performances were compared. The results show that the separation performances of these membranes were strongly related to the silicone rubber components and composition, the total fluxes decreased in the following order: PDMS > PPMS > PEOMS > PTFMS. The separation factor followed the following order: PPMS > PEOMS > PDMS > PTFMS (5 wt % ethanol at 40°C). In addition, the effects of the feed temperature (40–70°C) and feed composition (5–20 wt %) on the separation efficiency were investigated experimentally. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Oxidation of alcohols mediated by a polymer supported potassium ferrate as an effective mild oxidant
Authors: Karimi Zarchi Mohammad Ali , Taefi Mohammad
Published: September 2010

The use of polymeric oxidizing agents simplifies routine oxidation of reactions because it eliminates the traditional purification. In this article, the use of the cross‐linked poly (4‐vinylpyridine)‐supported potassium ferrate as an effective mild polymeric oxidizing agent is described. This reagent is capable of oxidizing organic compounds and can be used as a versatile reagent in organic synthesis. Primary and secondary benzylic and allylic alcohols are converted selectively to their carbonyl compounds, and hydroquinone to the 1, 4‐benzoquinone. This polymeric reagent seems to be nontoxic and nonpollutant. Based on our observation during the study, the polymeric reagent is stable and can be stored for months without losing its activity. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Autoimmune‐mediated reduction of high‐density lipoprotein–cholesterol and paraoxonase 1 activity in systemic lupus erythematosus–prone gld mice
Authors: Srivastava Roshni , Yu Shaohua , Parks Brian W. , Black Leland L. , Kabarowski Janusz H.
Published: September 2010

Objective

To characterize modifications of high‐density lipoprotein (HDL) in autoimmune gld mice that may be relevant to premature atherosclerosis in systemic lupus erythematosus, and to assess their relationship to specific aspects of autoimmune disease.

Methods

HDL cholesterol (HDL‐C), apolipoprotein A‐I (Apo A‐I), paraoxonase 1 (PON1) activity, hepatic gene expression, and HDL biogenesis were measured in aging female gld and wild‐type congenic mice. Autoantibodies, lymphoid organs, and cytokines were analyzed by enzyme‐linked immunosorbent assay, flow cytometry, and multiplex assay, respectively.

Results

Plasma HDL‐C, HDL Apo A‐I, and HDL‐associated PON1 activity were reduced in aging gld mice in association with the development of autoimmunity, independent of changes in hepatic Apo A‐I and PON1 expression or HDL biogenesis. Hepatic induction of the acute‐phase reactant serum amyloid A1 resulted in its incorporation into HDL in gld mice. Deletion of the lipid‐sensitive receptor G2A in gld mice (G2A−/− gld) attenuated reductions in HDL‐C and PON1 activity without altering hepatic Apo A‐I and PON1 expression, HDL biogenesis, or levels of acute‐phase proinflammatory cytokines. Plasma anti–Apo A‐I autoantibodies were elevated in aging gld mice commensurate with detectable increases in Apo A‐I immune complexes. Autoantibody levels were lower in aging G2A−/− gld mice compared with gld mice, and anti–Apo A‐I autoantibody levels were significantly related to HDL‐C concentrations (r = −0.645, P < 0.00004) and PON1 activity (r = −0.555, P < 0.0007) among autoimmune gld and G2A−/− gld mice.

Conclusion

Autoantibodies against Apo A‐I contribute to reducing HDL‐C and PON1 activity in autoimmune gld mice independently of hepatic HDL biogenesis, suggesting that functional impairment and premature clearance of HDL immune complexes may be principal mechanisms involved.
Cluster-randomized, crossover trial of the efficacy of plain soap and water versus alcohol-based rub for surgical hand preparation in a rural hospital in Kenya
Authors: Nthumba P M , Stepita-Poenaru E , Poenaru D , Bird P , Allegranzi B , Pittet D , Harbarth S
Published: September 2010

Background

The aim of this cluster-randomized, crossover trial was to compare the efficacy of plain soap and water with an alcohol-based handrub for surgical hand preparation and prevention of surgical-site infection (SSI) in a Kenyan rural hospital.

Methods

A total of 3317 patients undergoing clean and clean-contaminated surgery were included. Follow-up data 30 days after discharge were available for 3133 patients (94·5 per cent).

Results

SSI occurred in 255 patients (8·1 per cent), with similar rates for both study arms: 8·3 per cent for alcohol-based handrub versus 8·0 per cent for plain soap and water (odds ratio 1·03, 95 per cent confidence interval 0·80 to 1·33). After adjustment for imbalances between study arms and clustering effects, the main outcome measure remained unchanged (adjusted odds ratio 1·06, 0·81 to 1·38). The duration of surgery and wound contamination class independently predicted SSI. The cost difference between the methods was small (€4·60 per week for alcohol-based handrub compared with €3·30 for soap and water).

Conclusion

There was no statistically or clinically significant difference in SSI rates, probably because more important factors contribute to SSI development. However, this study demonstrated the feasibility and affordability of alcohol-based handrubs for hand preparation before surgery in settings without continuous, clean water. Registration number: NCT00987402 (http://www.clinicaltrials.gov).
Systematic review and meta-analysis of preoperative antisepsis with chlorhexidine versus povidone–iodine in clean-contaminated surgery
Authors: Noorani A , Rabey N , Walsh S R , Davies R J
Published: September 2010

Background

Surgical-site infection increases morbidity, mortality and financial burden. The preferred topical antiseptic agent (chlorhexidine or povidone–iodine) for preoperative skin cleansing is unclear.

Methods

A meta-analysis of clinical trials was conducted to determine whether preoperative antisepsis with chlorhexidine or povidone–iodine reduced surgical-site infection in clean-contaminated surgery.

Results

The systematic review identified six eligible studies, containing 5031 patients. Chlorhexidine reduced postoperative surgical-site infection compared with povidone–iodine (pooled odds ratio 0·68, 95 per cent confidence interval 0·50 to 0·94; P = 0·019).

Conclusion

Chlorhexidine should be used preferentially for preoperative antisepsis in clean-contaminated surgery.
Role of platelets in experimental acute pancreatitis
Authors: Abdulla A , Awla D , Hartman H , Rahman M , Jeppsson B , Regnér S , Thorlacius H
Published: September 2010

Background

Platelets not only control thrombosis and haemostasis but may also regulate inflammatory processes. Acute pancreatitis (AP) is characterized by changes in both coagulation and proinflammatory activities. The role of platelets in AP is not yet known.

Methods

AP was induced in C57BL/6 mice by repeated caerulein administration (50 µg/kg intraperitoneally). Mice received a platelet-depleting or control antibody before caerulein challenge. Neutrophil infiltration, myeloperoxidase (MPO) and macrophage inflammatory protein (MIP) 2 levels, acinar cell necrosis and haemorrhage in the pancreas, as well as serum amylase activity, were determined 24 h after caerulein injection. In an alternative model of pancreatitis, L-arginine (4 g/kg intraperitoneally) was given twice with an interval of 1 h and tissue samples were taken after 72 h [Correction added after online publication 29 September 2010: in the preceding sentence, 4 mg/kg was corrected to 4 g/kg].

Results

Caerulein administration increased acinar cell necrosis, neutrophil infiltration, focal haemorrhage and serum amylase levels. Platelet depletion reduced acinar cell necrosis, haemorrhage and serum amylase levels in AP. Depletion of platelets decreased caerulein-induced MPO levels and neutrophil recruitment in the pancreas. Platelet depletion abolished caerulein-induced MIP-2 generation in the pancreas and circulation. The effects of platelet depletion on necrosis, neutrophils and MPO levels were confirmed in L-arginine-induced pancreatitis.

Conclusion

Platelets play a crucial role in AP by regulating neutrophil infiltration, most likely mediated by MIP-2 production in the pancreas.
Efficient Extraction of Lycopene from Rhodopseudomonas palustris with n‐Hexane and Methanol after Alkaline Wash
Authors: Bao Y. , Yan H. , Liu L. , Xu Q.
Published: September 2010

Extraction of lycopene from Rhodopseudomonas palustris with various solvents and alkaline wash was investigated. Dichloromethane or benzene as single polar or nonpolar solvent were the most effective solvents. The maximum extraction efficiency was achieved with a combination of n‐hexane and methanol (1:1 v/v). which was approximately one time higher than that obtained with a single solvent. The partitioning behavior of lycopene in n‐hexane/methanol indicated that almost all extracted lycopene from R. palustris cells was dissolved in the n‐hexane phase. Further studies showed that lycopene extraction was much improved after an alkaline wash of R. palustris cells. The measured lycopene content was much higher than that in tomatoes which indicates that R. palustris will become an important biological resource of lycopene.
Effect of Emulsification Conditions on the Properties of Microspheres Prepared by a Solvent Extraction Process
Authors: Heiskanen H. , Denifl P. , Hurme M. , Pitkänen P.
Published: September 2010

Microspheres can be prepared using a hydrocarbon‐perfluorocarbon‐based solvent extraction process. The effect of changing the surfactant amount, emulsification temperature, and stirring speed on the size of microspheres was investigated. The surfactant concentration was found to greatly affect the microsphere size and size distribution. The Sauter mean diameter of the microspheres decreased exponentially as a function of surfactant concentration. The microsphere size distribution became narrower with increasing surfactant concentration. A clear correlation between the Sauter mean diameter of the microspheres and the Weber number was found. A surfactant concentration was identified at which the size of microspheres remained constant although the Weber number was changed. Finally, a lower emulsification temperature decreased the coalescence of the droplets and microspheres with smaller Sauter mean diameter were produced when using a low surfactant concentration.
Crystallization of Hen Egg White Lysozyme by Solvent Freeze‐Out: Effect of Cooling Rate on Protein Inclusion in the Ice Layer
Authors: Ryu B.‐H. , Jones M. J. , Ulrich J.
Published: September 2010

A new technique for crystallizing proteins is introduced. Solvent removal by freezing‐out is employed to crystallize hen egg white lysozyme from aqueous salt solutions. The crystallization is carried out at moderate salt concentrations (1–10 wt % NaCl) and at pH 4.4–5.2. The required supersaturation for nucleation and crystal growth is achieved by removal of the solvent resulting in a concentration increase with respect to salt, buffer, and protein. A simple tube and shell heat exchanger is used to generate the driving force for crystallization of the ice. The enzymatic activity of the resulting crystals is measured after their dissolution and shows large variations with respect to the crystallization conditions, though no systematic behavior is observed. The effect of the cooling rate applied to the cold finger upon the protein concentration in the ice is investigated.
Enhanced Adsorption Affinity of Anionic Perylene‐Based Surfactants towards Smaller‐Diameter SWCNTs
Authors: Backes Claudia , Mundloch Udo , Schmidt Cordula D. , Coleman Jonathan N. , Wohlleben Wendel , Hauke Frank , Hirsch Andreas
Published: September 2010

We present evidence from multiple characterization methods, such as emission spectroscopy, zeta potential, and analytical ultracentrifugation, to shed light on the adsorption behavior of synthesized perylene surfactants on single‐walled carbon nanotubes (SWCNTs). On comparing dispersions of smaller‐diameter SWCNTs prepared by using cobalt–molybdenum catalysis (CoMoCAT) with the larger‐diameter SWCNTs prepared by high‐pressure carbon monoxide decomposition (HiPco), we find that the CoMoCAT–perylene surfactant dispersions are characterized by more negative zeta potentials, and higher anhydrous specific volumes (the latter determined from the sedimentation coefficients by analytical ultracentrifugation), which indicates an increased packing density of the perylene surfactants on nanotubes of smaller diameter. This conclusion is further supported by the subsequent replacement of the perylene derivatives from the nanotube sidewall by sodium dodecyl benzene sulfonate (SDBS), which first occurs on the larger‐diameter nanotubes. The enhanced adsorption affinity of the perylene surfactants towards smaller‐diameter SWCNTs can be understood in terms of a change in the supramolecular arrangement of the perylene derivatives on the scaffold of the SWCNTs. These findings represent a significant step forward in understanding the noncovalent interaction of π‐surfactants with carbon nanotubes, which will enable the design of novel surfactants with enhanced selectivity for certain nanotube species.
Metal‐Catalyzed Cycloetherification Reactions of β,γ‐ and γ,δ‐Allendiols: Chemo‐, Regio‐, and Stereocontrol in the Synthesis of Oxacycles
Authors: Alcaide Benito , Almendros Pedro , Carrascosa Rocío , Martínez del Campo Teresa
Published: September 2010

Versatile routes that lead to a variety of functionalized enantiopure tetrahydrofurans, dihydropyrans, and tetrahydrooxepines are based on chemo‐, regio‐, and stereocontrolled metal‐catalyzed oxycyclization reactions of β,γ‐ and γ,δ‐allendiols, which were readily prepared from (R)‐2,3‐O‐isopropylideneglyceraldehyde. The application of PdII, PtII, AuIII, or LaIII salts as the catalysts gives controlled access to differently sized oxacycles in enantiopure form. Usually, chemoselective cyclization reactions occurred exclusively by attack of the secondary hydroxy group (except for the oxybromination of phenyl β,γ‐allenic diols 3 b and 3 d) to an allenic carbon atom. Regio‐ and stereocontrol issues are mainly influenced by the nature of the metal catalysts and substituents.
Tunable Hydrophobicity in DNA Micelles: Design, Synthesis, and Characterization of a New Family of DNA Amphiphiles
Authors: Anaya Milena , Kwak Minseok , Musser Andrew J. , Müllen Klaus , Herrmann Andreas
Published: September 2010

This work describes the synthesis and characterization of a new family of DNA amphiphiles containing modified nucleobases. The hydrophobicity was imparted by the introduction of a dodec‐1‐yne chain at the 5‐position of the uracil base, which allowed precise and simple tuning of the hydrophobic properties through solid‐phase DNA synthesis. The micelles formed from these modified DNA sequences were characterized by atomic force microscopy, dynamic light scattering, and polyacrylamide gel electrophoresis. These experiments revealed the role of the quantity and location of the hydrophobic units in determining the morphology and stability of the micelles. The effects of hybridization on the physical characteristics of the DNA micelles were also studied; these results showed potential for the sequence‐specific noncovalent functionalization of the self‐assembled aggregates.
Automatically constructing semantic link network on documents
Authors: Zhuge Hai , Zhang Junsheng
Published: September 2010

Knowing semantic links among resources is the basis of realizing machine intelligence over large‐scale resources. Discovering semantic links among resources with limited human interference is a challenge issue. This paper proposes an approach to automatically discovering and predicting semantic links in a document set based on a model of document semantic link network (SLN). The approach has the following advantages: it supports probabilistic relational reasoning; SLNs and the relevant rules automatically evolve; and, it can adapt to the update of the adopted techniques. The approach can support cyber space applications, such as documentation recommendation and relational queries, on large documents. Copyright © 2010 John Wiley & Sons, Ltd.
Dynamic software updates for parallel high‐performance applications
Authors: Kim Dong Kwan , Tilevich Eli , Ribbens Calvin J.
Published: September 2010

Despite using multiple concurrent processors, a typical high‐performance parallel application is long‐running, taking hours, even days to arrive at a solution. To modify a running high‐performance parallel application, the programmer has to stop the computation, change the code, redeploy, and enqueue the updated version to be scheduled to run, thus wasting not only the programmer's time, but also expensive computing resources. To address these inefficiencies, this article describes how dynamic software updates (DSU) can be used to modify a parallel application on the fly, thus saving the programmer's time and using expensive computing resources more productively. The net effect of updating parallel applications dynamically can reduce the total time that elapses between posing a problem and arriving at a solution, otherwise known as time‐to‐discovery. To explore the benefits of dynamic updates for high performance applications, this article takes a two‐pronged approach. First, we describe our experiences of building and evaluating a system for dynamically updating applications running on a parallel cluster. We then review a large body of literature describing the existing state of the art in DSU and point out how this research can be applied to high‐performance applications. Our experimental results indicate that DSU have the potential to become a powerful tool in reducing time‐to‐discovery for high‐performance parallel applications. Copyright © 2010 John Wiley & Sons, Ltd.
Observation of Filamentary Structures on the Boundary Region of the LHD Stellarator
Authors: Carralero D. , Shoji M. , de la Cal E. , van Milligen B. Ph. , de Pablos J. L. , Hidalgo C. , Yamada H.
Published: September 2010

Large Helical Device (LHD) high β regime discharges are observed with a fast camera, with 〈β 〉 values up to almost 5%. High frequency sequences (20 µs between shots) of the density fluctuations in the edge region are obtained. Macroscopic coherent scructures, in the shape of “comet”‐like filaments can be seen in these sequences, propagating from the external ergodic region to the wall. These structures are analyzed and their radial and parallel transport is discussed. Strong relation between the generation of low frequency particle ejections and m/n= 2/3 edge mode is found. In the strike point region, “reflected” structures are observed as a response to ejected filaments. These are discussed in terms of plasma wall interaction phenomena (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Collisionless Drift Waves Ranging from Current‐Driven, Shear‐Modified, and Electron‐Temperature‐Gradient Modes
Authors: Hatakeyama R. , Moon C. , Tamura S. , Kaneko T.
Published: September 2010

The specific history of collisionless drift waves is marked by focusing upon current‐driven, shear‐modified, and electron‐temperature‐gradient modes. Studies of current‐driven collisionless drift waves started in 1977 using the Innsbruck Q machine and was continued over 30 years until 2009 with topics such as plasma heating by drift waves in fusion‐oriented confinement and space/astrophysical plasmas. Superposition of perpendicular flow velocity shear on parallel shear intensively modifies the drift wave characteristics through the variation of its azimuthal structure, where the parallel‐shear driven instability is suppressed for strong perpendicular shears, while hybrid‐ion velocity shear cause unexpected stabilization of the parallel‐shear‐modified drift wave. An electron temperature gradient can be formed easily by control of thermionic electron superimposed on ECR plasma, and is found to excite low‐frequency fluctuation in the range of drift waves (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Positively Biased Probes in Magnetized Plasmas
Authors: Stenzel R. L. , Urrutia J. M. , Ionita C. , Schrittwieser R.
Published: September 2010

Positively biased probes in magnetized plasmas can create several phenomena which are not described by standard probe theories. These include transient currents for pulsed electrodes in the regime of Electron MHD, relaxation oscillations induced by large probes and high frequency instabilities at the sheath‐plasma frequency. Although they may limit the use of probes for diagnostic purposes they also offer new applications and belong to the general knowledge of probes in plasmas (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear Effects Related to the Simultaneous Excitation of Three Instabiities in Magnetized Plasma
Authors: Dimitriu D. G. , Ionita C. , Schrittwieser R.
Published: September 2010

Experimental results are presented on the nonlinear effects related to the simultaneous excitation of three low‐frequency instabilities in the magnetized plasma column of a Q‐machine, namely the potential relaxation instability, the electrostatic ion‐cyclotron instability and the Kelvin‐Helmholtz instability. The influence of electron drift and magnetic field intensity on appearance, dynamics and mutual interaction of these instabilities was investigated (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Detection and confirmation of 60 anabolic and androgenic steroids in equine plasma by liquid chromatography‐tandem mass spectrometry with instant library searching
Authors: Liu Ying , Uboh Cornelius E. , Soma Lawrence R. , Li Xiaoqing , Guan Fuyu , You Youwen , Rudy Jeffrey A. , Chen Jin‐Wen
Published: September 2010

In 2008, Pennsylvania (PA) became the first State in the USA to ban and enforce the ban on the use of anabolic and androgenic steroids (AAS) in equine athletes by using plasma for analysis. To enforce the ban, a rapid and high‐throughput method for analysis of 60 AAS in equine plasma was developed by liquid chromatography‐tandem mass spectrometry (LC‐MS/MS). Analytes were recovered from plasma by liquid‐liquid extraction (LLE) using methyl tert‐butyl ether, separated on a reversed‐phase C18 column and analyzed by electrospray ionization mass spectrometry. Multiple‐reaction monitoring (MRM) scan was employed for screening. When the MRM signal of an analyte exceeded 1000 counts per second (cps), information‐dependent acquisition (IDA) triggered generation of an enhanced product ion (EPI) scan of the analyte. A library for the analytes was simultaneously established using the EPI spectrum. Unambiguous identification of any of the 60 AAS in a test sample was based on both the presence of MRM response within the correct retention time (tR) window and a qualitative match between EPI spectrum of the test sample and that of the reference drug standard stored in the library. Total analysis time was 7 min. The limit of detection (LOD) and limit of confirmation (LOC) for most of the analytes were 0.01–2 ng/mL and 0.1–10 ng/mL, respectively. Recovery of the analytes from plasma by LLE was 74–138%. The method was successfully verified and is routinely used in the screening of post‐race equine plasma samples for the presence of these 60 AAS. The method is rapid, sensitive, reproducible, and reliable. Copyright © 2010 John Wiley & Sons, Ltd.
Characterization of zebrafish intestinal smooth muscle development using a novel sm22α‐b promoter
Authors: Seiler Christoph , Abrams Joshua , Pack Michael
Published: September 2010

Smooth muscle cells provide structural support for many tissues and control essential physiological processes, such as blood pressure and gastrointestinal motility. Relatively little is known about the early stages of intestinal smooth muscle development and its relationship to the development of the enteric nervous system, which regulates intestinal motility. Here, we report an evolutionarily conserved 523 base pair regulatory element within the promoter of the zebrafish sm22α‐b (transgelin1) gene that directs transgene expression in smooth muscle cells of the intestine and other tissues. Comparative genomic analysis identified a conserved motif within this element consisting of two Serum Response Factor binding sites that is also present in the promoters of many mammalian smooth muscle genes. We established a stable line expressing GFP in smooth muscle cell and used this line to describe lineage relationships among cells within different intestinal smooth muscle layers and their co‐development with the enteric nervous system (ENS). Developmental Dynamics 239:2806–2812, 2010. © 2010 Wiley‐Liss, Inc.
Molecular cloning and embryonic expression of zebrafish PCSK5 co‐orthologues: Functional assessment during lateral line development
Authors: Chitramuthu Babykumari P. , Baranowski David C. , Cadieux Benoît , Rousselet Estelle , Seidah Nabil G. , Bennett Hugh P.J.
Published: September 2010

Pro‐protein convertase subtilisin/kexin 5 (PC5, also known as PC6) is a member of the subtilisin‐like superfamily of serine proteases implicated in the maturation of latent precursor proteins into their functionally active derivatives. To investigate the functional roles, we have cloned the cDNA sequences encoding two candidate zebrafish PC5 convertases (designated as PCSK5.1 and PCSK5.2) co‐orthologous to the single PC5 encoding gene (PCSK5) found in mammals. Both display syntenic correspondence to the human PCSK5 gene. Overall gene architecture has been conserved across species. While PC5.1 mRNA expression is very discrete within the otic vesicle and lateral line neuromasts, PC5.2 transcripts are more ubiquitously expressed within the central nervous system together with specific localization in various organs including liver, intestine, and otic vesicle. Zebrafish PC5.1‐deficient embryos display abnormal neuromast deposition within the lateral line system and lack a normal touch response, consistent with the known sensory role that the lateral line plays in spatial awareness and sensing the environment. Developmental Dynamics 239:2933–2946, 2010. © 2010 Wiley‐Liss, Inc.
Measurement of leak current generation distribution in PEFC and its application to load fluctuation testing under low humidification
Authors: Nakamura Soshin , Kashiwa Eiichi , Sasou Hidetoshi , Hariyama Suguru , Aoki Tsutomu , Ogami Yasuji , Nishikawa Hisao
Published: September 2010

A study was performed to establish a method for measuring the position and amount of leak current increase during operation of a fuel cell. This measurement method was applied to load fluctuation testing at low humidification and the increase in the leak current was observed in the downstream zone of the cell. The tested cell was disassembled and cross sections were observed under the SEM. The SEM images revealed the formation of a Pt band near the cathode catalyst in the downstream zone of the cell. This may be the cause of the degradation of the membrane at the downstream. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 174(1): 1–9, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21038
Mesoporous Nickel–Aluminum Mixed Oxide: A Promising Catalyst in Hydride‐Transfer Reactions
Authors: Paul Manidipa , Pal Nabanita , Bhaumik Asim
Published: September 2010

The design and synthesis of a new nanostructured material that can efficiently catalyze selective reduction reactions in an eco‐friendly way is an active area of research today. Here a mesoporous Ni–Al mixed oxide material has been synthesized hydrothermally by using lauric acid as capping agent. The mesoporosity observed in the material is mainly originated from the interparticle voids created due to the self‐assembly of the nanoparticles (NPs) in the presence of capping agent used during the synthesis. The material has been characterized by powder XRD, N2 sorption, high‐resolution transmission electron microscopy (HRTEM), scanning electron microscopy/energy‐dispersive spectroscopy (SEM‐EDS), FTIR, and thermogravimetric/differential thermal analysis (TG‐DTA) tools. The mesoporous Ni–Al mixed‐oxide material showed a very high Brunauer–Emmett–Teller (BET) surface area (337 m2 g–1) and excellent catalytic activity in a selective liquid‐phase hydride‐transfer reduction reaction of nitroarenes to their corresponding anilines in the presence of 2‐propanol as hydride source.
Nitrogen stripping to remove dissolved oxygen from extra virgin olive oil
Authors: Masella Piernicola , Parenti Alessandro , Spugnoli Paolo , Calamai Luca
Published: September 2010

The stripping treatment of extra virgin olive oil (EVOO) by nitrogen gas to remove dissolved oxygen (DO) was tested immediately after the oil production. Dissolved oxygen was measured before and after stripping, as well as one week later along with chemical analyses with the aim to assess the effects of the stripping treatment on EVOO quality. Stripping gave a great reduction of DO, of ca 50%. Both stripped (SO) and non‐stripped (non‐SO) oil samples showed a fast DO consumption up to zero in seven days. At this time, the non‐SO samples showed significant higher peroxide value probably as a consequence of the initial higher DO concentration that gives a greater formation of free radicals. A slightly lower concentration of total phenols was recorded for SO samples. A slight but significant decrease was recorded for only (E)‐hex‐2‐enal concentration within the volatile compounds.
Cross‐metathesis of methyl 10‐undecenoate with diethyl maleate: Formation of an α,ω‐diester via a metathesis reaction network
Authors: Behr Arno , Gomes Jessica Pérez , Bayrak Zeynep
Published: September 2010

The cross‐metathesis of methyl 10‐undecenoate 1 derived from castor oil as a renewable raw material with diethyl maleate 2 was investigated. These reactions were carried out with several phosphine and N‐heterocyclic carbene ruthenium catalysts. The reaction conditions were optimised for high conversions in combination with high cross‐metathesis selectivity. This single‐step and atom‐economic synthetic method illustrates an efficient and selective preparation procedure of linear α,ω‐dicarboxylic acid esters starting from renewable resources and comparatively inexpensive base chemicals. Further by‐products are hardly obtained due to their consumption in secondary metathesis reactions. Hence, a sustainable alternative for polyamide and polyester monomers is presented.
InIII‐Catalysed Tandem C–C and C–O Bond Formation between Phenols and Allylic Acetates
Authors: Vece Vito , Ricci Jérémy , Poulain‐Martini Sophie , Nava Paola , Carissan Yannick , Humbel Stéphane , Duñach Elisabet
Published: September 2010

Indium triflate catalysed tandem allylation–intramolecular hydroalkoxylation was efficiently carried out by using 1 mol‐% of the catalyst under mild conditions to afford the dihydrobenzopyran ring system (chroman‐type structure) in good yields. Kinetic, mechanistic and theoretical studies are also presented.
Dual CD system‐modified MEEKC method for the determination of clemastine and its impurities
Authors: Orlandini Serena , Giannini Iacopo , Navarro Mercedes Villar , Pinzauti Sergio , Furlanetto Sandra
Published: September 2010

A dual system of CDs was used for the first time in MEEKC with the aim of determining clemastine and its three main related impurities in both drug substances and tablets. The addition of methyl‐β‐cyclodextrin and heptakis(2,6‐di‐O‐methyl)‐β‐cyclodextrin to the microemulsion pseudo‐stationary phase was essential to increase the resolving power of the system to obtain a baseline separation among the compounds. The best microemulsion composition was identified by mixture design and the effects of the factors concentrations of CDs and voltage were investigated by a response surface study applying a Central Composite Design. In both cases, Derringer's desirability function made it possible to find the global optimum, which corresponded to the following combination: microemulsion, 89.8% 10 mM borate buffer pH 9.2, 1.5% n‐heptane and 8.7% of SDS/n‐butanol in 1:2 ratio; 18 mM methyl‐β‐cyclodextrin, 38 mM heptakis(2,6‐di‐O‐methyl)‐β‐cyclodextrin, 17 kV. By applying these conditions, the separation was completed in about 5.5 min. The method was validated following International Conference on Harmonisation guidelines and was applied to a real sample of clemastine tablets.
Simultaneous determination of nine endogenous steroids in human urine by polymeric‐mixed micelle capillary electrophoresis
Authors: Flor Sabrina , Lucangioli Silvia , Contin Mario , Tripodi Valeria
Published: September 2010

A new CE system based on the use of polymeric‐mixed micelles (cholic acid, SDS and the poloxamine Tetronic® 1107) was developed for the simultaneous determination of nine steroids in human urine. This method allows the baseline separation and quantitation of cortisol, androstenedione, estriol, dehydroepiandrosterone sulfate, testosterone, dehydroepiandrosterone, estrone, progesterone and estradiol in less than 25 min showing to be sensitive enough to detect low concentrations of these steroids in urine samples (5–45 ng/mL). The optimized electrophoretic conditions were performed using a 50 cm×75 μm capillary, 18 kV, 25°C, with 44 mM cholic acid, 10 mM SDS, 0.05% w/v tetronic® 1107, 2.5% v/v methanol, 2.5% v/v tetrahydrofuran in 5 mM borate – 5 mM phosphate buffer (pH=8.0) as a background electrolyte and a dual 210/254 UV‐detection. The method can simultaneously determine 0.1–120 μg/mL, which corresponds to 5–6000 ng/mL of steroids in 2 mL urine. The recoveries ranged between 82.4 and 101.5%. Due to its simplicity, speed, accuracy and reliability, the proposed method could be a potential alternative to the traditional methodologies used with clinical purposes.
Detrapping particles in gel electrophoresis: A numerical study of different pulsed field sequences
Authors: Dubé Antoine , Slater Gary W.
Published: September 2010

Large particles tend to get trapped in dead‐ends more often than small particles when electrophoresed in random cross‐linked gels. It is known that pulsed electric fields can be used to free particles from these traps, leading to an increase in velocity and improved size separation. Although numerical and theoretical models have been proposed for the mobility of smaller particles in the so‐called Ogston sieving limit, the effect of pulsed fields on trapping has not been previously modeled. We present a numerical study of detrapping and we compare our results with those of To and Boyde (To, K.‐Y., Boyde, T. R., Electrophoresis 1993, 14, 597). We use an exact numerical method to examine detrapping in various two‐dimensional systems of obstacles. We also propose and investigate new ways to optimize the pulse sequence in order to separate particles of different sizes.