bluuebunny/crossref_metadata_2025 huggingface dataset:
Developing Polypyrrole-Based Oligonucleotide Biosensors
Authors: Booth Marsilea Adela , Harbison Sally Ann , Travas-Sejdic Jadranka
Published: September 2011

Many medical, forensic science, environmental and general scientific difficulties may be aided by the existence of suitable biosensors such as gene sensors, body fluid detection DNA sensors, disease detection DNA sensors etc. The sensor technology described here uses the conducting polymer polypyrrole (PPy) as both sensing element and transducer of sensing events. Stability and reproducibility are necessary characteristics of practical biosensors. The stability of polymers can be investigated using electrical impedance spectroscopy (EIS). This work discusses research focused towards creating a stable, reproducible sensor surface for oligonucleotide detection. The effect of electropolymerisation conditions (electropolymerisation method, solvent and electrolyte used), post-growth treatment (cycling and EIS experiments), and the sensing-environment conditions on sensor stability and applicability will be discussed.
Observation of Diatom Settling and Photocatalytic Antifouling on TiO2 Using ATR-IR Spectroscopy
Authors: Kemmitt Tim , Young Aidan G. , Depree Craig
Published: September 2011

The settling of marine diatoms Amphora coffeaeformis onto a photocatalytic titanium dioxide surface was monitored by ATR-IR. Attachment of the diatoms via their mucilaginous secretions was monitored via observation of protein amide I and II linkages, carboxylate linkages from a uronic acid polysaccharide, and sulfate ester groups. Exposure to UV-A light resulted in the rapid removal of the groups attached to the photocatalyst surface, demonstrating the potential antifouling capability of a TiO2 anatase surface.
Ferromagnetism in MgTiO3-Ti2O3 Solid Solutions
Authors: Fujioka Yukari , Frantti Johannes , Nieminen Risto M.
Published: September 2011

Ti-rich Mg1ЎxTi1+xO3 samples were synthesized by solid-state reaction. Sampleswere characterized by room temperature x-ray powder di®raction, scanning electron microscopyand energy dispersive spectroscopy of x-rays. Hexagonal lattice parameters a and c increasedwith increasing Ti content. Time-of-Flight-Secondary-Ion-Mass-Spectroscopy (ToF-SIMS, de-tection limit 10Ў6) measurements revealed that no magnetic impurities were present. Sampleswith x = 0:10; 0:12 and 0:32 showed ferromagnetic hysteresis loops. The result demonstratesthat excess Ti at the Mg-O cation layer controls the magnetic properties. This is a technologicaladvantage especially for thin Їlm applications.
Improvement of BTEX Adsorption Using Silylated RH-MCM-41 Synthesized from Rice Husk Silica
Authors: Areerob Thanita , Grisdanurak Nurak , Chiarakorn Siriluk
Published: September 2011

RH-MCM-41, a mesoporous molecular sieve, was successfully synthesized from silica extracted from rice husk. The presence of silanol functional group (Si-OH) on its surface causes adverse effects on the adsorption of some non-polar compounds, especially benzene, toluene, ethylbenzene and xylene (BTEX). Thus, this work aims to enhance the adsorbability of RH-MCM-41 on BTEX adsorption by in-situ and ex-situ silylation. Trimethylchlorosilane (TMCS) was used as a silylating reagent to reduce silanol groups. The ex-situ silylation was carried out by adding as-synthesized RH-MCM-41 into 5% v/v of TMCS solution at 30°C and stirring for 24 h. While the in-situ silylated sample was prepared by mixing 5% v/v of TMCS solution and RH-MCM-41 precursor solution at 80°C and stirring for 120 h. The adsorption capacity of gaseous BTEX using the silylated RH-MCM-41 was determined by gas chromatography equipped with a flame ionization detector (GC-FID) with a thermal desorption unit (TDU). The adsorption capacities of the ex-situ samples were 0.617 mg g-1 for benzene, 1.271 mg g-1 for toluene, 1.902 mg g-1 for ethylbenzene and 0.036 mg g-1 of xylene, higher than that of the in-situ and the unsilylated samples. Thus, the ex-situ silylation is suitable for enhancement of hydrophobicity of RH-MCM-41. The ex-situ silylated RH-MCM-41 has the potential to be applied in gaseous BTEX treatment.
Effects of Implanted Fe+ Fluences on the Growth and Magnetic Properties of Surface Nanoclusters
Authors: Leveneur Jérôme , Kennedy John , Williams Grant V. M. , Fang Fang , Metson James B. , Markwitz Andreas
Published: September 2011

We have fabricated surface magnetic iron nanoclusters using low energy Fe+ implantation and electron beam annealing. We find that changing the fluence has a significant effect on the nanocluster growth, structural and magnetic properties. Low fluences lead to small nanoclusters and superparamagnetism, while high fluences result in larger chain-like nanoclusters that have high remnant magnetizations and a significantly reduced saturation field. Our results show that the nanostructure and the magnetic properties can be tuned by varying the Fe+ fluence, which means that a reliable method can be used to make surface nanoclusters for a variety of applications (e.g. large magnetoresistance sensors with no hysteresis).
Design Parameters for a Two-State Nanomemory Device
Authors: Lee Richard K. F. , Hill James M.
Published: September 2011

In this study, we investigate the internal mechanics for a two-state memory device,comprising a charged metallofullerene which is located inside a closed carbon nanotube.Assuming the Lennard-Jones interaction energy and the continuum approximation, the metallofullerenehas two symmetrically placed equal minimum energy positions. On one side theencapsulated metallofullerene represents the zero information state and by applying an externalelectrical field, the metallofullerene can be made to overcome the energy barrier of thenanotube, and pass from one end of the tube to the other, where the metallofullerene thenrepresents the one information state.
Overlapping-Gate Architecture for Silicon Hall Bar MOSFET Devices in the Low Electron Density and High Magnetic Field Regime
Authors: Van Beveren Laurens H. Willems , Tan Kuan Yen , Lai Nai Shyan , Klochan Oleh , Dzurak Andrew S. , Hamilton Alex R.
Published: September 2011

A common issue in low temperature measurements of enhancement-mode metal-oxide-semiconductor (MOS) field-effect transistors (FETs) in the low electron density regime is the high contact resistance dominating the device impedance. In that case a voltage bias applied across the source and drain contact of a Hall bar MOSFET will mostly fall across the contacts (and not across the channel) and therefore magneto-transport measurements become challenging. However, from a physical point of view, the study of MOSFET nanostructures in the low electron density regime is very interesting (impurity limited mobility [1], carrier interactions [2,3] and spin-dependent transport [4]) and it is therefore important to come up with solutions [5,6] that work around the problem of a high contact resistance in such devices (c.f. Fig. 1 (a)).
The Link between the PDL1 Costimulatory Pathway and Th17 in Fetomaternal Tolerance
Authors: D’Addio Francesca , Riella Leonardo V. , Mfarrej Bechara G. , Chabtini Lola , Adams La Tonya , Yeung Melissa , Yagita Hideo , Azuma Miyuki , Sayegh Mohamed H. , Guleria Indira
Published: September 2011

Fetomaternal tolerance has been shown to depend both on regulatory T cells (Tregs) and negative signals from the PD1–PDL1 costimulatory pathway. More recently, IL-17–producing T cells (Th17) have been recognized as a barrier in inducing tolerance in transplantation. In this study, we investigate the mechanisms of PDL1-mediated regulation of fetomaternal tolerance using an alloantigen-specific CD4+ TCR transgenic mouse model system (ABM-tg mouse). PDL1 blockade led to an increase in embryo resorption and a reduction in litter size. This was associated with a decrease in Tregs, leading to a lower Treg/effector T cell ratio. Moreover, PDL1 blockade inhibited Ag-specific alloreactive T cell apoptosis and induced apoptosis of Tregs and a shift toward higher frequency of Th17 cells, breaking fetomaternal tolerance. These Th17 cells arose predominantly from CD4+Foxp3− cells, rather than from conversion of Tregs. Locally in the placenta, similar decrease in regulatory and apoptotic markers was observed by real-time PCR. Neutralization of IL-17 abrogated the anti-PDL1 effect on fetal survival rate and restored Treg numbers. Finally, the adoptive transfer of Tregs was also able to improve fetal survival in the setting of PDL1 blockade. This is to our knowledge the first report using an alloantigen-specific model that establishes a link between PDL1, Th17 cells, and fetomaternal tolerance.
Blockade of Notch Ligand Delta1 Promotes Allograft Survival by Inhibiting Alloreactive Th1 Cells and Cytotoxic T Cell Generation
Authors: Riella Leonardo V. , Ueno Takuya , Batal Ibrahim , De Serres Sacha A. , Bassil Ribal , Elyaman Wassim , Yagita Hideo , Medina-Pestana José O. , Chandraker Anil , Najafian Nader
Published: September 2011

The Notch signaling pathway has been recently shown to contribute to T cell differentiation in vitro. However, the in vivo function of Notch signaling in transplantation remains unknown. In this study, we investigated the importance of Delta1 in regulating the alloimmune response in vivo. Delta1 expression was upregulated on dendritic cells and monocytes/macrophages upon transplantation in a BALB/c into B6 vascularized cardiac transplant model. Whereas administration of anti-Delta1 mAb only slightly delayed survival of cardiac allografts in this fully MHC-mismatched model, it significantly prolonged graft survival in combination with single-dose CTLA4-Ig or in CD28 knockout recipients. The prolongation of allograft survival was associated with Th2 polarization and a decrease in Th1 and granzyme B-producing cytotoxic T cells. The survival benefit of Delta1 blockade was abrogated after IL-4 neutralization and in STAT6KO recipients, but was maintained in STAT4KO recipients, reinforcing the key role of Th2 cell development in its graft-prolonging effects. To our knowledge, these data demonstrate for the first time an important role of Delta1 in alloimmunity, identifying Delta1 ligand as a potential novel target for immunomodulation in transplantation.
On the role of dust storms in triggering atmospheric gravity waves observed in the middle atmosphere
Authors: Das S. K. , Taori A. , Jayaraman A.
Published: September 2011

Abstract. Lower atmospheric perturbations often produce measurable effects in the middle and upper atmosphere. The present study demonstrates the response of the middle atmospheric thermal structure to the significant enhancement of the lower atmospheric heating effect caused by dust storms observed over the Thar Desert, India. Our study from multi-satellite observations of two dust storm events that occurred on 3 and 8 May 2007 suggests that dust storm events produce substantial changes in the lower atmospheric temperatures as hot spots which can become sources for gravity waves observed in the middle atmosphere.
Recent trends in daily temperature extremes over northeastern Spain (1960–2006)
Authors: El Kenawy A. , López-Moreno J. I. , Vicente-Serrano S. M.
Published: September 2011

Abstract. Spatial and temporal characteristics of extreme temperature events in northeastern Spain have been investigated. The analysis is based on long-term, high-quality, and homogenous daily maximum and minimum temperature of 128 observatories spanning the period from 1960 to 2006. A total of 21 indices were used to assess changes in both the cold and hot tails of the daily temperature distributions. The presence of trends in temperature extremes was assessed by means of the Mann-Kendall test. However, the autocorrelation function (ACF) and a bootstrap methodology were used to account for the influence of serial correlation and cross-correlation on the trend assessment. In general, the observed changes are more prevalent in hot extremes than in cold extremes. This finding can largely be linked to the increase found in the mean maximum temperature during the last few decades. The results indicate a significant increase in the frequency and intensity of most of the hot temperature extremes. An increase in warm nights (TN90p: 3.3 days decade−1), warm days (TX90p: 2.7 days decade−1), tropical nights (TR20: 0.6 days decade−1) and the annual high maximum temperature (TXx: 0.27 °C decade−1) was detected in the 47-yr period. In contrast, most of the indices related to cold temperature extremes (e.g. cold days (TX10p), cold nights (TN10p), very cold days (TN1p), and frost days (FD0)) demonstrated a decreasing but statistically insignificant trend. Although there is no evidence of a long-term trend in cold extremes, significant interdecadal variations were noted. Almost no significant trends in temperature variability indices (e.g. diurnal temperature range (DTR) and growing season length (GSL)) are detected. Spatially, the coastal areas along the Mediterranean Sea and the Cantabrian Sea experienced stronger warming compared with mainland areas. Given that only few earlier studies analyzed observed changes in temperature extremes at fine spatial resolution across the Iberian Peninsula, the results of this work can improve our understanding of climatology of temperature extremes. Also, these findings can have different hydrological, ecological and agricultural implications (e.g. crop yields, energy consumption, land use planning and water resources management).
Synchronization and desynchronization in the Olami-Feder-Christensen earthquake model and potential implications for real seismicity
Authors: Hergarten S. , Krenn R.
Published: September 2011

Abstract. The Olami-Feder-Christensen model is probably the most studied model in the context of self-organized criticality and reproduces several statistical properties of real earthquakes. We investigate and explain synchronization and desynchronization of earthquakes in this model in the nonconservative regime and its relevance for the power-law distribution of the event sizes (Gutenberg-Richter law) and for temporal clustering of earthquakes. The power-law distribution emerges from synchronization, and its scaling exponent can be derived as τ = 1.775 from the scaling properties of the rupture areas' perimeter. In contrast, the occurrence of foreshocks and aftershocks according to Omori's law is closely related to desynchronization. This mechanism of foreshock and aftershock generation differs strongly from the widespread idea of spontaneous triggering and gives an idea why some even large earthquakes are not preceded by any foreshocks in nature.
Effect on Anxiety of Education Programme about Care of Arteriovenous Fistula in Patients Undergoing Hemodialysis
Authors: Mollaoğlu Mukadder , Tuncay Fatma Özkan , Fertelli Tülay Kars , Yürügen Birsen
Published: September 2011

Purpose

This study investigated the impact of education, provided to individuals, in whom AV fistula was preferred as a vascular access, regarding information and anxiety.

Methods

This experimental study was performed on 32 patients undergoing hemodialysis between November 2009 and February 2010 in the Nephrology Clinic of Sivas Cumhuriyet University Hospital. Patients' data was collected by means of Personal Information Form (PIF), AV Fistula Information Form (AV-FIF), and Beck Anxiety Inventory (BAI); education brochures were used in order to inform the individuals. Collected data were assessed with SPSS. Statistical analyses were used in order to assess the data: percentage account, paired samples t test.

Results

When comparing information and anxiety score of individuals prior to and following education about AV fistula care, it was seen that information and anxiety scores were low and high respectively, prior to the education. Following education, patients' information and anxiety scores became higher and lower respectively. All these results were statistically significant (P< 0.001).

Conclusions

Education about fistula increased the information level about fistula care and decreased anxiety in patients undergoing hemodialysis. It is important to perform patient education regularly, because it increases the level of orientation towards illness and interventions in patients.
Nanolaminates Utilizing Size‐Dependent Homogeneous Plasticity of Metallic Glasses
Authors: Kim Ju‐Young , Jang Dongchan , Greer Julia R.
Published: September 2011

Homogeneous plasticity in metallic glasses is generally only observed at high temperatures or in very small structures (less than ≈100 nm), so their applications for structural performance have been very limited. Here, nanolaminates with alternating layers of Cu50Zr50 metallic glass and nanocrystalline Cu are synthesized and it is found that samples with an optimal composition of 112‐nm‐thick metallic‐glass layers and 16‐nm‐thick Cu layers demonstrate a maximum strength of 2.513 GPa, a value 33% greater than that predicted by the rule‐of‐mixtures and 25% better than that of pure Cu50Zr50 metallic glass. Furthermore, ≈4% strain at fracture is achieved, suppressing the instantaneous catastrophic failure often associated with metallic glasses. It is postulated that this favorable combination of high strength and deformability is caused by the size‐dependent deformation‐mode transition in metallic glasses, from highly localized plasticity, leading to immediate failure in larger samples to homogeneous extension in the smaller ones.
In Situ crystallization to zinc aluminate films with controlled surface microstructure and anticorrosion performance
Authors: Fan Guoli , Li Feng
Published: September 2011

Spinel‐type zinc aluminate (ZnAl2O4) thin films with controlled surface microstructure on aluminum substrates were fabricated via a facile and effective in situ crystallization method without using any templates or surfactants. The surface microstructure of ZnAl2O4 films could be significantly controlled by varying the experimental conditions including concentration of reactants, crystallization temperature, and crystallization time. After surface modification, the specific topography of ZnAl2O4 films was beneficial to obtain surface hydrophobic or superhydrophobic properties. More importantly, compared to nanoparticle‐ and nanosword‐assembled ZnAl2O4 films, nanorod‐assembled ZnAl2O4 film provided a more effective barrier to aggressive species for aluminum substrates in a wide range of pH values; very low corrosion current density of the order of ∼10−19 A cm−12 could be achieved. A new contribution to the development of advanced coating system with ZnAl2O4 film materials that can be used in practical application for corrosion protection of aluminum materials is provided. © 2011 American Institute of Chemical Engineers AIChE J, 2012
Derivation of critical and optimal operating conditions for a semibatch reactor under parametric uncertainty based on failure probability indices
Authors: Maria Gheorghe , Dan Anca
Published: September 2011

Derivation of optimal operating policies and runaway boundaries for a semibatch reactor (SBR), when highly exothermic reactions are conducted and hazardous side reactions may occur, is a difficult task because of multiple sources of process uncertainty to be considered (variability in raw materials, catalyst, impurities, model inaccuracies, measurement errors, technological, economic and safety constraints). The present work introduces a new criterion based on failure probability indices related to uncertainty in the runaway boundaries and disturbances of the operating parameters. Such a criterion is used not only to derive more prudent SBR optimal operating policies but also to appreciate rapprochement to critical conditions. An example is provided for an SBR used for conducting the hazardous acetoacetylation of pyrrole with diketene in homogeneous liquid phase catalysis. Both uncertainties in evaluating the runaway boundaries, with a generalized sensitivity criterion, and of the running conditions are used to generate optimal operating strategies, making a satisfactory compromise between the productivity goal and safety requirements. © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.
Preparation and properties of polytetrafluorethylene filled ethylene–propylene–diene monomer composites
Authors: Zhao Guozhang , Shi Liyi , Fu Jifang , Feng Xin , Ding Peng , Zhuo Jing
Published: September 2011

Ethylene–propylene–diene monomer/polytetrafluorethylene (EPDM/PTFE) composites based on EPDM and electron beam irradiated PTFE powders (MS‐II, MS‐III, and MS‐V, with mean diameter 5 μm, 1 μm, and 0.1 μm, respectively) were prepared by a mechanical compounding technique. The curing characteristics, morphologies, mechanical properties, and abrasion behaviors of these composites were investigated. The curing measurements indicated that the addition of lower loading of MS‐III or MS‐V enhanced the lubrication of EPDM compounds and delayed the curing process. The morphological structure of the composites demonstrated that the MS‐III and MS‐V were uniformly dispersed in EPDM matrix and the efficient polymer–filler interfacial interactions were constructed. In comparison with EPDM/MS‐II and EPDM/MS‐III, EPDM/MS‐V exhibited outstanding tensile strength, tear strength, elongation at break, and abrasion resistance due to the nanometer particle dimension and good dispersion of MS‐V as well as the stronger interfacial interactions between MS‐V and the EPDM matrix. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Properties of osmanthus fragrance‐loaded chitosan–sodium tripolyphosphate nanoparticles delivered through cotton fabrics
Authors: Hu Jing , Xiao Zuo‐bing , Ma Shuang‐shuang , Zhou Ru‐jun , Wang Ming‐xi , Li Zhen
Published: September 2011

Osmanthus fragrance‐loaded chitosan nanoparticles (OF‐NPs) were prepared via complex coacervation successfully. Then, the OF‐NPs were applied in the cotton fabrics directly. The microstructures of OF‐NPs were characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), Fourier transformation infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The sustained property of the cotton fabrics treated with OF‐NPs was investigated with scanning electron microscopy (SEM) and gas chromatography‐mass spectrometry (GC‐MS). The common OF was also treated on fabrics for the parallel comparison. TEM and DLS displayed that the spherical OF‐NPs kept about 130 nm and dispersed evenly. FTIR confirmed that OF had been interacted with chitosan via the hydrogen bonds. TGA demonstrated that the thermal stability of OF‐NPs had been improved in contrast to OF and the loading content of OF was as high as 12.05%. SEM and GC‐MS displayed that the cotton fabrics treated by OF‐NPs had an excellent washing resistance. Overall, nanoencapsulation with CS‐TPP will provide an excellent method for releasing fragrance. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Preparation and characterization of thermoplastic polyurethane–urea and carboxylated acrylonitrile butadiene rubber blend nanocomposites
Authors: Mahmood Nasir , Ullah Khan Asad , Ali Zulfiqar , Sohail Khan Mohammad , Haq Anwar‐Ul , Werner Stöckelhuber Klaus , Gohs Uwe , Heinrich Gert
Published: September 2011

This study deals with the preparation and characterization of novel thermoplastic polyurethane–urea (TPUU) and carboxylated acrylonitrile butadiene rubber (XNBR) blends. Blends of different compositions were prepared in tetrahydrofuran using a solution technique, following an ultra‐sonication. The chemical reaction between the two inherently immiscible blend phases was determined with the help of Fourier transform infrared‐attenuated total reflectance (FTIR‐ATR) spectroscopy and 1H‐nuclear magnetic resonance (1H‐NMR) spectroscopy. The identification of the new peaks in the FTIR‐ATR spectra corroborates the existence of chemical reaction between the carboxylic functional group of XNBR and the amide group of the TPUU. In addition, an increase in the network crosslink density of the blend investigated using 1H‐NMR spectroscopy further supports the occurrence of the chemical reaction between the XNBR and the TPUU. The scanning and transmission electron micrographs of the blend morphology show a uniform dispersion of the minor TPUU phase in the XNBR. Furthermore, the existence of a single glass transition peak also confirms the enhancement in the interfacial miscibility. Additionally, the incorporation of 5 wt % of organomodified montmorillonite nanoclay improves the mechanical properties to a considerable extent in comparison with the unfilled blend elastomeric material. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Free‐standing hybrid anion‐exchange membranes for application in fuel cells
Authors: Lin Xiaocheng , Wu Cuiming , Wu Yonghui , Xu Tongwen
Published: September 2011

A series of free‐standing hybrid anion‐exchange membranes were prepared by blending brominated poly(2,6‐dimethyl‐1,4‐phenylene oxide) (BPPO) with poly(vinylbenzyl chloride‐co‐γ‐methacryloxypropyl trimethoxy silane) (poly(VBC‐co‐γ‐MPS)). Apart from a good compatibility between organic and inorganic phases, the hybrid membranes had a water uptake of 32.4–51.8%, tensile strength around 30 MPa, and Td temperature at 5% weight loss around 243–261°C. As compared with the membrane prepared from poly (VBC‐co‐γ‐MPS), the hybrid membranes exhibited much better flexibility, and larger ion‐exchange capacity (2.19–2.27 mmol g−1) and hydroxyl (OH−) conductivity (0.0067–0.012 S cm−1). In particular, the hybrid membranes with 60–75 wt % BPPO had the optimum water uptake, miscibility between components, and OH− conductivity, and were promising for application in fuel cells. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis and Antioxidant Evaluation of Some New 3‐Substituted Coumarins
Authors: Hamama Wafaa S. , Berghot Moged A. , Baz Eman A. , Gouda Moustafa A.
Published: September 2011

3‐Acetylcoumarin (1) was utilized as a key intermediate for the synthesis of 2‐aminothiazole derivative 3 via bromination of 1 to afford acetylbromide 2 followed by treatment with thiourea or via Biginelli reaction of 1. Treatment of 3 with 5‐chloro‐3‐methyl‐1‐phenyl‐1H‐pyrazole‐4‐carbaldehyde, 2‐methyl‐4H‐benzo[d][1,3]oxazin‐4‐one, furo[3,4‐b]pyrazine‐5,7‐dione or 2‐methyl‐5,6,7,8‐tetrahydro‐4H‐benzothieno[2,3‐d][1,3]oxazin‐4‐one afforded diazine derivatives 4–7. Also, pyridopyrimidine 8 was obtained via a one pot reaction of 6‐aminothiouracil, p‐chlorobenzaldehyde and 3‐acetylcoumarin. Moreover, refluxing of 6‐aminothiouracil with one equivalent amount of 2 afforded the thiazolopyrimidine 9, while the pyrrolothiazolopyrimidine 10 was revealed when two equivalent amounts of 2 was used. Furthermore, treatment of enamine 11 with 2‐aminobenzothiazole or 6‐aminothiouracil afforded the pyrimidine derivatives 12 and 13, respectively. Transamination of enamine 11 with m‐anisidine followed by cyclization of the resulting enaminone 14 gave the desired quinoline 15. Also, treatment of 11 with thiophenol in dioxane gave the mercapto derivative 16. Moreover, coupling of 11 with 4,6‐dimethyl‐1H‐pyrazolo[3,4‐b]pyridin‐3‐yl‐diazonium chloride, followed by complete cyclization of the resulting product afforded the pyridopyrazolothiazine 19 via the intermediate 18. Furthermore, the pyrazolopyrimidine 20 was revealed via a one pot condensation of 11, 3‐methyl‐1‐phenyl‐1H‐pyrazol‐5(4H)‐one and ammonium acetate. The thiadiazine derivatives 21–23 were obtained via treatment of 2 with the corresponding o‐aminothiols. Desulphonation of 23 afforded the pyrazolotriazine 24. Finally, reaction of 2 with 2‐hydroxybenzaldehyde gave benzofuran derivative 25. Representative compounds of the synthesized products were evaluated as antioxidant agents.
Synthesis and Cytotoxicity Studies of Novel 2‐Hydrazonylpyrido[2,3‐b]pyrazin‐3(4H)‐ones
Authors: Zhang Guogang , Liu Yajing , Wang Shuobing , Zhou Chuan , Huang Qingchang , Gong Ping
Published: September 2011

In an attempt to develop potent antitumor agents, a series of novel 2‐hydrazonylpyrido[2,3‐b]pyrazin‐3(4H)‐one derivatives were designed and synthesized. All the prepared compounds were screened for their cytotoxic activities against A549, MDA‐MB‐231 and HT‐29 cell lines in vitro. Pharmacological data indicated that five of the target compounds showed cytotoxicity against A549 cell line below a concentration of 1 µM. Compound 15g was the most potent one with IC50 values of 0.19, 2.11 and 2.15 µM against A549, MDA‐MB‐231 and HT29 cell lines, respectively.
A phase II, multicenter, open‐label study evaluating dosing and preliminary safety and efficacy of canakinumab in systemic juvenile idiopathic arthritis with active systemic features
Authors: Ruperto Nicolino , Quartier Pierre , Wulffraat Nico , Woo Patricia , Ravelli Angelo , Mouy Richard , Bader‐Meunier Brigitte , Vastert Sebastiaan J. , Noseda Emanuele , D'Ambrosio Daniele , Lecot Jean , Chakraborty Abhijit , Martini Alberto , Chioato Andrea ,   Paediatric Rheumatology International Clinical Trials Organisation
Published: September 2011

Objective

To assess dosing, preliminary safety, and efficacy of canakinumab, a fully human anti–interleukin‐1β (anti–IL‐1β) antibody, in children with systemic juvenile idiopathic arthritis (JIA) and active systemic features.

Methods

In this phase II, multicenter, open‐label, dosage‐escalation study, children with systemic JIA who were ≥4 years of age, had fever, and were receiving ≤0.4 mg/kg/day of corticosteroids were administered a single subcutaneous dose of canakinumab, 0.5–9 mg/kg of body weight, and were redosed upon relapse. Response to treatment was assessed according to an adaptation of the American College of Rheumatology (ACR) pediatric criteria for improvement.

Results

A total of 23 children ages 4–19 years with active disease were enrolled. Of these, 1 patient was excluded from analysis, and 3 of the reenrolled patients were included twice in the efficacy analysis. By day 15 of the first treatment cycle, 15 of 25 patients (60%) had achieved an adapted ACR Pediatric 50 response, with 4 of them achieving inactive disease status. Response was sustained over time, with 11 of 13 patients able to maintain their response throughout the study. In 8 of the 11 responders who had been receiving steroids at baseline, the steroid dosage was decreased from a mean of 0.38 mg/kg/day to 0.13 mg/kg/day over the first 5 months, and 4 of them were able to discontinue steroids. At a dose of 4 mg/kg of canakinumab given subcutaneously every 4 weeks, the median percentage of patients predicted to relapse within 4 weeks was estimated to be 6% (95% confidence interval 1–21). Therapy was generally well tolerated and few patients experienced injection‐site reactions.

Conclusion

Canakinumab has a promising preliminary safety and efficacy profile in this limited cohort. Based on the findings of this trial, further studies in a larger population of children with systemic JIA are warranted.
Silk tape nanostructure and silk gland anatomy of trichoptera
Authors: Ashton Nicholas N. , Taggart Daniel S. , Stewart Russell J.
Published: September 2011

Caddisflys (order Trichoptera) construct elaborate protective shelters and food harvesting nets with underwater adhesive silk. The silk fiber resembles a nanostructured tape composed of thousands of nanofibrils (∼ 120 nm) oriented with the major axis of the fiber, which in turn are composed of spherical subunits. Weaker lateral interactions between nanofibrils allow the fiber to conform to surface topography and increase contact area. Highly phosphorylated (pSX)4 motifs in H‐fibroin blocks of positively charged basic residues are conserved across all three suborders of Trichoptera. Electrostatic interactions between the oppositely charged motifs could drive liquid–liquid phase separation of silk fiber precursors into a complex coacervates mesophase. Accessibility of phosphoserine to an anti‐phosphoserine antibody is lower in the lumen of the silk gland storage region compared to the nascent fiber formed in the anterior conducting channel. The phosphorylated motifs may serve as a marker for the structural reorganization of the silk precursor mesophase into strongly refringent fibers. The structural change occurring at the transition into the conducting channel makes this region of special interest. Fiber formation from polyampholytic silk proteins in Trichoptera may suggest a new approach to create synthetic silk analogs from water‐soluble precursors. © 2011 Wiley Periodicals, Inc. Biopolymers 97: 432–445, 2012.
Determination of enalapril and enalaprilat in small human serum quantities for pediatric trials by HPLC–tandem mass spectrometry
Authors: Ramusovic Sergej , Thielking Gabriele , Läer Stephanie
Published: September 2011

The angiotensin converting enzyme‐inhibitor enalapril is the prodrug of enalaprilat and used in the treatment pediatric hypertension and chronic heart failure. Pharmacokinetic data are lacking to provide adequate dosing and for pediatric pharmacotherapeutical trials it is imperative to minimize sample volume. Therefore an HPLC‐tandem mass spectrometry (MS) method for the determination of enalapril and enalaprilat in 100 μL of human serum was developed and validated with benazepril as internal standard (IS). After solid‐phase extraction, chromatography was performed on a Luna® RP‐C18(2) column with methanol–water–formic acid (65:35:1, v/v/v) as mobile phase and a flow rate of 0.4 mL/min. The MS was set to positive‐mode electrospray ionization and multiple reaction monitoring, analyzing the m/z transitions channels 377.3 → 234.2, 349.3 → 206.1 and 425.3 → 351.2 for enalapril, enalaprilat and IS. Calibration curves were linear in the range of 1.61–206 ng/mL (enalapril) and 1.84–236 ng/mL (enalaprilat) with coefficients of determination >0.99. Relative standard deviations of intra‐ and inter‐run precisions were below 7% and relative errors were below 6 ± 7% for both analytes. Also stabilities were acceptable for both analytes. As an application example, concentrations of enalapril and enalaprilat in serum after oral administration of 20 mg enalapril maleat in a healthy volunteer were determined. Copyright © 2011 John Wiley & Sons, Ltd.
Simultaneous Carbonation and Sulfation of CaO in Oxy‐Fuel CFB Combustion
Authors: Wang C. , Jia L. , Tan Y.
Published: September 2011

For anthracites and petroleum cokes, the typical combustion temperature in a circulating fluidized bed (CFB) is > 900 °C. At CO2 concentrations of 80–85 % (typical of oxy‐fuel CFBC conditions), limestone still calcines. When the ash which includes unreacted CaO cools to the calcination temperature, carbonation of fly ash deposited on cool surfaces may occur. At the same time, indirect and direct sulfation of limestone also will occur, possibly leading to more deposition. In this study, CaO was carbonated and sulfated simultaneously in a thermogravimetric analyzer (TGA) under conditions expected in an oxy‐fuel CFBC. It was found that temperature, and concentrations of CO2, SO2, and especially H2O are important factors in determining the carbonation/sulfation reactions of CaO.
Experimental and Numerical Studies of the Flow Field in a Stirred Tank Equipped with Multiple Side‐Entering Agitators
Authors: Fang J. , Ling X. , Sang Z.‐F.
Published: September 2011

The flow field and the macro‐mixing process in a stirred tank equipped with four side‐entering agitators were investigated experimentally and numerically. Experiments were conducted using two‐dimensional particle image velocimetry (PIV) measurements to characterize the flow field at different positions in the vessel. The computational fluid dynamics (CFD) simulation was performed by the software Fluent 6.3, using the standard k‐ϵ turbulent model and the multiple reference frame together with the sliding mesh technique. The macro‐mixing process was also discussed using CFD and decolorization experiments. The effects of the tracer detection positions and some mounting parameters in the mixing system were discussed. The results show that the mixing process was dominated by the flow field pattern in the stirred tank. According to the mixing times under different conditions using CFD simulation, the mounting parameters including inclination angle, plunging length and mounting height of the shaft were optimized.
Combining Different Frequencies for Electrical Heating of Saturated and Unsaturated Soil Zones
Authors: Roland U. , Holzer F. , Kopinke F.‐D.
Published: September 2011

In situ electrical heating of soil was studied applying different frequencies: low‐frequency energy for resistive heating and radio‐frequency energy for dielectric heating. Steep temperature gradients were observed for each heating mode under the condition of the coexistence of saturated and unsaturated soil zones. By combining the two heating modes, this undesired effect can be avoided, thus allowing efficient soil remediation especially when organic phases are accumulated at the capillary fringe. A parallel application of both frequencies was demonstrated as the most suitable method to reduce temperature gradients. By using electronic filters, both electric fields can be established by only one electrode array. This innovative concept is especially applicable for optimizing thermal remediation of light non‐aqueous phase liquid contaminations or realizing thermally‐enhanced electrokinetic removal of heavy metals.
Self‐Report Reasons for Alcohol Use in Bipolar Disorders: Why Drink Despite the Potential Risks?
Authors: McDonald Jennifer L. , Meyer Thomas D.
Published: September 2011

High rates of alcohol use and misuse are commonly reported for bipolar disorder (BD) and in many cases, these impact detrimentally on the course and treatment of the disorder. Therefore, knowing the reasons individuals with a diagnosis of BD give for drinking alcohol is essential for understanding this association and for treatment. This paper aimed to systematically review the literature relating to self‐reported reasons and motives for alcohol use in BD. By using internet‐based search engines such as PsycINFO and Medline, six relevant studies were identified and then quality‐assessed using a set of criteria specifically developed for this review. Overall, the findings supported the intuitive notion that individuals with a diagnosis of BD use alcohol to relieve distressing mood states. However, there was evidence of other mood‐related and mood‐unrelated reasons—e.g., drinking to enhance euphoric mood or to be sociable. These findings are discussed in relation to the self‐medication hypothesis and cognitive motivational models of alcohol use developed in the general population. The quality assessment also revealed several limitations including diagnostically heterogeneous samples and inconsistencies in measurement between studies, and recommendations for addressing these limitations are given. Copyright © 2011 John Wiley & Sons, Ltd.

Key Practitioner Message

Although implicitly alcohol use in patients with bipolar disorders is often been interpreted as evidence of a co‐morbid alcohol use disorder or an inadequate coping pattern, it is essential to test this belief as a clinician.

An adequate formulation has to consider that the motives to drink alcohol vary between patients with bipolar disorders and might also vary between mood states.
Effect of Mesoporous TiO2 Bead Diameter in Working Electrodes on the Efficiency of Dye‐Sensitized Solar Cells
Authors: Chen Yang , Huang Fuzhi , Chen Dehong , Cao Lu , Zhang Xiao Li , Caruso Rachel A. , Cheng Yi‐Bing
Published: September 2011

Mesoporous TiO2 beads with diameters of 320±50, 550±50, and 830±40 nm, comprising interconnected and densely packed TiO2 nanocrystals, were used as working electrodes for dye‐sensitized solar cells (DSCs). These electrodes possess high surface areas and superior light‐scattering properties, which are ideal for DSC applications. Although the electrode prepared by using 320±50 nm beads demonstrated the highest dye loading and the electrode prepared by using 550±50 nm beads showed the best light‐scattering properties in the wavelength region λ=400–800 nm, DSC devices with working electrodes composed of 830±40 nm beads achieved the highest power conversion efficiencies of 9.0 % after treatment with TiCl4. A higher electron diffusion rate (4.35×10−4 cm2 s−1) and an extended electron lifetime (58 ms) were observed in DSCs composed of the largest beads, 830±40 nm, attributable to a reduced amount of inter‐bead barriers and a relatively small percentage of TiO2 nanocrystals on the surface of the beads, compared to cells containing 550±50 and 320±50 nm beads.
Optimized transgenesis in Xenopus laevis/gilli isogenetic clones for immunological studies
Authors: Nedelkovska Hristina , Robert Jacques
Published: September 2011

Xenopus laevis provides a unique animal model, alternative to mouse, to study immunology. Even though, several methodologies have been developed for the generation of transgenic Xenopus, to date none have been adapted for the X. laevis/gilli (LG) isogenetic clones that are essential for immunological studies. Since LG clones are generated via gynogenesis, transgenic methods using transgene integration into the sperm nuclei are not suited. Therefore, we have tested three alternative methods for LG transgenesis: the phiC31 integrase, the Sleeping Beauty transposase, and the I‐SceI meganuclease. All three techniques produced transgenic LG clones; however, the I‐SceI meganuclease was most effective. It resulted in high transgenesis efficiency (35–50%), bright nonmosaic GFP expression as well as stable germline transmission with 100% of the progeny carrying the transgene. Production of transgenic LG clones will allow us to modulate immune gene expression and further strengthen X. laevis as a biomedical model. genesis 50:300–306, 2012. © 2011 Wiley Periodicals, Inc.
Planar Chirality of Imidazole‐Containing Macrocycles – Understanding and Tuning Atropisomerism
Authors: Van Den Berge Emilie , Pospíšil Jiří , Trieu‐Van Tran , Collard Laurent , Robiette Raphaël
Published: September 2011

The synthesis and characterization of imidazole‐containing macrocycles displaying planar chirality has been achieved. HLPC and NMR studies revealed the crucial role of the alicyclic chain length in determining the rate of stereoisomerisation: 15‐ and 16‐membered cyclic compounds are chiral whereas their larger‐ringed analogues equilibrate rapidly at room temperature. Computational calculations are in good agreement with experimental observations and allow us to understand the mechanism and the interactions involved in the conformational equilibrium between the two atropisomers. Separation of the two enantiomers of the 15‐membered macrocycle by semipreparative chiral HPLC allowed us to investigate the influence of chirality on its biological activity.
A Rapid and Efficient Synthesis of D‐erythro‐Sphingosine from D‐ribo‐Phytosphingosine
Authors: van den Berg Richard J. B. H. N. , van den Elst Hans , Korevaar Cornelius G. N. , Aerts Johannes M. F. G. , van der Marel Gijsbert A. , Overkleeft Herman S.
Published: September 2011

In this paper we describe the concise synthesis of D‐erythro‐sphingosine starting from the readily available chiral building block D‐ribo‐phytosphingosine. The title compound is the ubiquitous sphingolipid from which most mammalian ceramides are derived. Our work is based on the existing literature in which the same sphingoid base is used as a starting point and culminates in what we believe is the most efficient synthesis of D‐erythro‐sphingosine reported to date.
Fast preparation of monolithic immobilized pH gradient column by photopolymerization and photografting techniques for isoelectric focusing separation of proteins
Authors: Liang Yu , Zhu Guijie , Wang Tingting , Zhang Xiaodan , Liang Zhen , Zhang Lihua , Zhang Yukui
Published: September 2011

A new method was developed to prepare monolithic immobilized pH gradient (M‐IPG) columns in UV‐transparent fused‐silica capillaries by the 5‐min photopolymerization of acrylamide and N,N′‐methylenebisacrylamide, followed by the 20‐min photografting of the focused ampholine‐derived glycidylmethacrylate monomer on the monolithic matrix, by which the preparation time was reduced, and the stability of the formed pH gradient was improved, compared with our previous methods. Using the prepared M‐IPG column, the baseline separation of proteins was achieved according to their pIs. Without carrier ampholytes added in the running buffer, the separated components could be detected with high sensitivity by UV at low wavelength.
Oncogene addiction as a foundational rationale for targeted anti‐cancer therapy: promises and perils
Authors: Torti Davide , Trusolino Livio
Published: September 2011

A decade has elapsed since the concept of oncogene addiction was first proposed. It postulates that – despite the diverse array of genetic lesions typical of cancer – some tumours rely on one single dominant oncogene for growth and survival, so that inhibition of this specific oncogene is sufficient to halt the neoplastic phenotype. A large amount of evidence has proven the pervasive power of this notion, both in basic research and in therapeutic applications. However, in the face of such a considerable body of knowledge, the intimate molecular mechanisms mediating this phenomenon remain elusive. At the clinical level, successful translation of the oncogene addiction model into the rational and effective design of targeted therapeutics against individual oncoproteins still faces major obstacles, mainly due to the emergence of escape mechanisms and drug resistance. Here, we offer an overview of the relevant literature, encompassing both biological aspects and recent clinical insights. We discuss the key advantages and pitfalls of this concept and reconsider it as an illustrative principle to guide post‐genomic cancer research and drug development.
Fire performance and mechanical properties of acrylonitrile‐butadiene‐styrene copolymer/modified expandable graphite composites
Authors: Hong Shinn‐Gwo , Chang Su‐Yao
Published: September 2011

The fire performance and mechanical properties of an acrylonitrile‐butadiene‐styrene (ABS) copolymer compounded with different expandable graphites (EG) and fire retardants were studied by using the limiting oxygen index test, the UL‐94 test, a mechanical test, and a thermogravimetric analysis. The ground EG treated with phosphoric acid and silane could have the great increase of the volume expansion ratio. The addition of the treated EG in ABS significantly enhances the fire performance but decreases the impact strength of ABS. ABS with the treated EG has a much higher impact strength than with the as‐received EG because of the smaller particle size of the treated EG and the better adhesion between the ABS and the treated EG. The addition of modified ammonium polyphosphate or decabromodiphenyl oxide/antimony trioxide can considerably improve the fire performance of ABS/treated EG composites because of a synergistic effect. The V‐0 grade (UL‐94) ABS composite with the limiting oxygen index of 32.5 can be obtained by adding small amounts of the treated EG and modified ammonium polyphosphate into ABS. Thermogravimetric analysis results indicate that the initial vapor release temperatures and the weight loss rates of ABS/EG composites are closely related to their fire performance and affected by the fire retardant used. Copyright © 2011 John Wiley & Sons, Ltd.