bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluorine‐Directed β‐Galactosylation: Chemical Glycosylation Development by Molecular Editing
Authors: Durantie Estelle , Bucher Christoph , Gilmour Ryan
Published: May 2012

Validation of the 2‐fluoro substituent as an inert steering group to control chemical glycosylation is presented. A molecular editing study has revealed that the exceptional levels of diastereocontrol in glycosylation processes by using 2‐fluoro‐3,4,6‐tri‐O‐benzyl glucopyranosyl trichloroacetimidate (TCA) scaffolds are a consequence of the 2R,3S,4S stereotriad. This study has also revealed that epimerization at C4, results in a substantial enhancement in β‐selectivity (up to β/α 300:1).
Effect of serum lipoproteins on stereoselective halofantrine metabolism by rat hepatocytes
Authors: Patel Jigar P. , Hamdy Dalia A. , El‐kadi A. O. , Brocks Dion R.
Published: May 2012

Experimental hyperlipidemia has shown to decrease cytochrome P450 3A4 and 2C11 expression and to increase liver concentrations and the plasma protein binding of halofantrine (HF) enantiomers. The present study examined the effect of hyperlipidemic (HL) serum on the metabolism of HF enantiomers by primary rat hepatocytes. Hepatocytes from normolipidemic (NL) and HL (poloxamer 407 treated) rats were incubated with rac‐HF in cell media with or without additional rat serum (5%). In those incubations with rat serum, the hepatocytes were preincubated or coincubated with serum from NL or HL rats. Rat serum‐free hepatocyte incubations served as controls. Stereospecific assays were used to measure HF and desbutylhalofantrine (its major metabolite) enantiomer concentrations in whole well contents (cells + media). Concentrations of desbutylhalofantrine were not measurable. The disappearance (apparent metabolism) of (−)‐HF exceeded that of antipode, but HF metabolism did not differ between hepatocytes from NL and HL rats. Coincubation of HL rat serum with NL hepatocytes caused a significant decrease in the disappearance of (−)‐HF, whereas in HL hepatocytes, a substantially decreased apparent metabolism was noted for both enantiomers. Compared with NL serum, (−)‐HF disappearance was significantly lowered upon preincubation of NL hepatocytes with HL serum. A combination of factors including diminished drug metabolizing or lipoprotein receptor expression, and increased plasma protein binding in the wells, may have contributed to a decrease in apparent metabolism of the HF enantiomers in the presence of lipoproteins from HL rat serum. Chirality 24:558–565, 2012. © 2012 Wiley Periodicals, Inc.
A study on semiflows generated by cooperative full‐range CNNs
Authors: Di Marco Mauro , Forti Mauro , Grazzini Massimo , Nistri Paolo , Pancioni Luca
Published: May 2012

The paper considers the full‐range (FR) model of cellular neural networks (CNNs) characterized by ideal hard‐limiter nonlinearities with two vertical segments in the current–voltage characteristic. It is shown that when the FRCNNs are cooperative, i.e., there are excitatory interconnections between distinct neurons, the generated solution semiflow is monotone and that monotonicity implies some fundamental restrictions on the geometry of omega‐limit sets. The result on monotonicity is a generalization to the class of differential inclusions describing the dynamics of FRCNNs of a classic result due to Kamke for cooperative ordinary differential equations. The paper also points out difficulties to use the standard theory of eventually strongly monotone (ESM) semiflows for addressing convergence of FRCNNs. By means of counterexamples, it is shown that, even assuming the irreducibility of the interconnections, the semiflow generated by a cooperative FRCNN is not ESM; furthermore, also the limit set dichotomy can be violated. Copyright © 2012 John Wiley & Sons, Ltd.
Photocatalytic and Photoelectrocatalytic Degradation of the Explosive RDX by TiO2 Thin Films Prepared by CVD and Anodic Oxidation of Ti
Authors: Tian Fang , Hitchman Michael L. , Shamlian Sarkis H.
Published: May 2012

Two kinds of TiO2 films prepared by CVD and by anodization of titanium mesh are compared for the photocatalytic (PC) and photoelectrocatalytic (PEC) degradation of RDX aqueous solutions illuminated under a 200 W UV light. The PC activity of anodically formed TiO2 is lower than that with CVD‐produced TiO2. The PC efficiencies of degradation of RDX with both anodized and CVD films are improved by applying a potential of 1 V versus saturated calomel electrode (SCE), with up to 95% of RDX being destroyed in two hours by a CVD‐produced TiO2 film, and 81% by anodized TiO2. Chemical analysis shows that during RDX degradation, nitrite is the first mineralized product which is further oxidized to nitrate.
New sources of retinoic acid synthesis revealed by live imaging of an Aldh1a2‐GFP reporter fusion protein throughout zebrafish development
Authors: Pittlik Silke , Begemann Gerrit
Published: May 2012

Background: Regulation of synthesis and turnover of retinoic acid (RA) is an important mechanism that controls the activity of RA signaling during vertebrate development. During embryonic patterning, the dynamic expression patterns of the aldh1a2 gene, which encodes a retinaldehyde dehydrogenase, provide the major source of RA, whereas the only other retinaldehyde dehydrogenase in teleosts, aldh1a3, is expressed later and locally restricted. Aldh1a2‐mediated RA synthesis has been shown to also regulate adult cell fates, such as during heart and fin regeneration. However, only very few other sites of postembryonic RA synthesis in vertebrates are known. We generated transgenic lines in zebrafish by BAC recombineering that express a fusion protein of Aldh1a2 and green fluorescent protein (GFP) under the control of endogenous aldh1a2 regulatory sequences (aldh1a2:gfp). Results:
aldh1a2:gfp reports the complete endogenous expression pattern in embryos and rescues embryonic lethality in aldh1a2 mutants. We identify novel postembryonic sources of RA synthesis, including lateral line support cells, in kidney‐derived organs that regulate calcium homeostasis, and in perichordal cells during vertebral development. Conclusions: The novel aldh1a2 reporter line is driven by the complete set of regulatory sequences required for zebrafish development, reports novel sources of RA synthesis, and identifies the source of RA that promotes vertebral ossification. Developmental Dynamics 241:1205–1216, 2012. © 2012 Wiley Periodicals, Inc.
Highly Oxidized Semiconducting Coordination Polymers – Coupled Oxidation and Coordination of Guanidine Electron Donors
Authors: Trumm Christine , Stang Simone , Eberle Benjamin , Kaifer Elisabeth , Wagner Norbert , Beck Johannes , Bredow Thomas , Meyerbröker Nikolaus , Zharnikov Michael , Hübner Olaf , Himmel Hans‐Jörg
Published: May 2012

Redox and coordination processes are coupled in the course of reactions of the organic electron donors 1,2,4,5‐tetrakis(tetramethylguanidino)benzene (1) and 1,2,4,5‐tetrakis(N,N′‐dimethyl‐N,N′‐ethyleneguanidino)benzene (2) with silver salts. Experiments with several different silver salts show that the product structure is significantly affected by the properties of the anion in these salts. Chain polymers are the products of reactions with AgPF6 or AgBF4, in which dicationic organic building blocks are connected by silver ions. Experiments with AgNO3 yielded either dinuclear complexes (with 1) or 2D networks (with 2). If the salt Ag[Al{OC(CF3)3}4], featuring a weakly coordinating anion, was used, simple silver‐free salts of the guanidine dication were obtained. The thermal stability, optical properties, and electrical conductivity were studied in detail for the product polymer {[(1)Ag](PF6)3}n. From the temperature dependence of the electric conductivity, this compound was found to be a semiconductor with a band gap of approximately 3 eV. The experiments were complemented by quantum chemical calculations at density‐functional‐theory level on the band structure of this and a related polymer. The electronic situation was further analyzed with the aid of molecular model complexes, which were either synthesized or calculated.
Multifunctional TiO2‐Coated Ag Nanowire Arrays as Recyclable SERS Substrates for the Detection of Organic Pollutants
Authors: Zhou Ying , Chen Jin , Zhang Li , Yang Liangbao
Published: May 2012

A novel method to prepare TiO2‐coated Ag nanowire arrays for use as multifunctional surface enhanced Raman scattering (SERS) active substrates is introduced. Such an array is made by the synthesis of an Ag nanowire array utilizing an anodic aluminum oxide (AAO) template, followed by coating of the Ag wires with a layer of titania that is several nanometers thick. Employing these TiO2‐coated Ag nanowire substrates in the detection of organic contaminants allows high SERS enhancement to be achieved. Moreover, owing to the high photocatalytic activity of titania, the substrate can degrade target molecules into small inorganic molecules under UV irradiation, and in this manner the arrays are able to self‐clean. The unique properties of this integrated substrate enable it to exhibit its feasibility as an analytical tool for the assessment of environmental pollution and thus to assist in the detection and disposal of contaminants.
A Vanadium‐Based Chemical Oscillator: Identification of Chemical Species Responsible for the Redox Reaction and Construction of a Simplified Model
Authors: Kanamori Kan , Kataoka Hiroshi , Matsugo Seiichi
Published: May 2012

To identify the chemical species involved in a unique, vanadium‐based chemical oscillator reaction, products derived from indole in the oscillation solution were isolated and characterized. NMR and mass spectra showed that 3,3‐dichloro‐2‐oxoindole and isatin were formed during the oscillation process. The formation of these two compounds suggests that peroxo species such as CHCl2OO· and CHCl2OOH play a key role in the construction of the oscillation system. A skeletal model for the system is proposed based on these findings.
Influence of Structure and Organic‐Inorganic Phase Interactions on Coating Mechanical Properties in the Ternary Goethite:Poly(HEMA):Silica System (Eur. J. Inorg. Chem. 16/2012)
Authors: Chemin Nicolas , Rozes Laurence , Chanéac Corinne , Cassaignon Sophie , Le Bourhis Eric , Jolivet Jean‐Pierre , Barthel Etienne , Sanchez Clément
Published: May 2012

The back cover picture highlights the mechanical and optical properties of a hybrid silica‐PHEMA coating on glass reinforced by using goethite nanorods in relation with the local structure at the interface. We demonstrate the possibility to finely tune the final mechanical properties by adjusting the coating silica content. In this hybrid nanocomposite, goethite particles exhibit interesting stress relaxation functions, which prevent crack formation in the films whilst reaching high silica content in the hybrid matrix. Details are discussed in the article by N. Chemin, C. Chanéac et al. on p. 2675 ff.

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Three‐Component Coupling of Aldehydes, Amines, and Alkynes Catalyzed by Oxidized Copper Nanoparticles on Titania (Eur. J. Org. Chem. 16/2012)
Authors: Albaladejo María José , Alonso Francisco , Moglie Yanina , Yus Miguel
Published: May 2012

The cover picture shows an example of diastereoselective aldehyde/amine/alkyne coupling catalyzed by copper nanoparticles supported on titania under solvent‐free conditions. The background picture depicts a panoramic view from Cerro Campanario (1052 m) in Bariloche (Río Negro, Argentina). This is one of the most beautiful and fascinating views in the region including: the East Perito Moreno's lake (aldehyde), West Perito Moreno's lake (amine), Trebol's pool (alkyne), Nahuel Huapi's lake (background), Llao Llao's peninsula and hotel, and the surrounding hills (López and Capilla in the foreground). Details are discussed in the article by F. Alonso et al. on p. 3093 ff.

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Electrochemistry and Simultaneous Detection of Metabolites of Purine Nucleotide Based on Large Mesoporous Carbon Modified Electrode
Authors: Liu Lina , Wang Huan , Bo Xiangjie , Yang Li , Guo Liping
Published: May 2012

A large mesoporous carbon modified glassy carbon electrode (LMC/GCE) was prepared. The morphology and structure of the LMC were characterized. The LMC/GCE was used to investigate the electrochemical behaviors of metabolites of purine nucleotide, uric acid (UA), xanthine (XA) and hypoxanthine (HX). The LMC/GCE exhibited high electrocatalytic activity towards the three compounds when compared with those obtained at the GCE. Furthermore, the LMC/GCE realized simultaneous determination of UA, XA and HX at a physiological pH of 7.0 with wide linear range and low detection limit. The electrocatalytic activity of the LMC/GCE towards guanine (G) and adenine (A) was also investigated.
Effects of Redox Couple on the Response of Polypyrrole‐Based Electrochemical DNA Sensors
Authors: Booth Marsilea Adela , Harbison SallyAnn , Travas‐Sejdic Jadranka
Published: May 2012

Much research‐to‐date exists to create sensitive and selective DNA sensors. A variety of approaches are adopted, including those involving polypyrrole and electrical impedance spectroscopy. Combined these are able to sense as well as aptly transduce signals. Many such sensors employ ferri/ferrocyanide to exhibit surface hybridization. This redox reporter, though with merits, can prove disadvantageous. To this end, a comparative study was performed with the redox reporter hydroquinone. For comparison purposes ferri/ferrocyanide indicated greater sensitivity, suggested to arise from inherent charge. Conversely, with hydroquinone steric hindrance is the main influencing factor. Such a study aims to guide design of analogous sensors.
Energy and the environment: How will EPA's newest regulations affect electric markets?
Authors: Lesser Jonathan A.
Published: May 2012

Last December, the US Environmental Protection Agency (EPA) put the finishing touches on new regulations to reduce emissions of mercury and other air toxics, primarily from coal‐fired power plants.1 Regulations targeting coal‐fired power plants are nothing new, really, as coal has been Public Enemy No. 1 for many environmentalists and environmental regulators for many years. The air toxics rule joins several others, including rules governing movements of air pollutants between states, disposal of coal ash, and discharges of cooling water.
Secular changes in personality: study on 75‐year‐olds examined in 1976–1977 and 2005–2006
Authors: Billstedt E. , Waern M. , Duberstein P. , Marlow T. , Hellström T. , Östling S. , Skoog I.
Published: May 2012

Objective

In order to study secular changes in personality factors neuroticism and extroversion, representative population samples of non‐demented 75‐year‐olds underwent psychiatric examinations in 1976–1977 (total n = 223, 138 women, 85 men) and 2005–2006 (total n = 556, 322 women and 234 men).

Methods

Eysenck Personality Inventory was used at both occasions. Demographic factors (educational level, marital status, having children) were registered.

Results

Seventy‐five‐year‐olds examined in 2005–2006 had higher values on extroversion and lower values on the Lie scale compared with those examined in 1976–1977. Neuroticism did not differ between the two birth cohorts. Neuroticism scores were higher in women than in men both in 1976–1977 and 2005–2006, and Lie score was higher in women than in men in 2005–2006.

Conclusions

Our findings suggest that present cohorts of 75‐year‐olds are more extroverted and less prone to respond in a socially desirable manner than those born three decades earlier. Neuroticism levels remained unchanged, suggesting this trait may be less influenced by environmental factors than the other traits studied. Copyright © 2012 John Wiley & Sons, Ltd.
Glycerol catalytic cyclocondensation with ethanediamine to pyrazinyl compounds over the modified SiO2‐Al2O3
Authors: Liu Chuanqi , Xu Chenghua , Xia Tongwei , Guo Yan , Liu Jianying
Published: May 2012

The Fe, Zn, and Mn‐modified SiO2‐Al2O3 catalysts for the glycerol vapor‐phase cyclocondensation with ethanediamine (ED) to 2‐pyrazinemethanol (2‐PMol) and 2‐methylpyrazine (2‐MP) in a fixed‐bed system were prepared by coprecipitation and characterized by N2 adsorption–desorption, X‐ray powder diffraction, and NH3 temperature‐programmed desorption (NH3‐TPD) in the present work. The results showed that the Mn‐modified SiO2‐Al2O3 catalyst with a SiO2/Al2O3 molar ratio 15.84 and 6% Mn gave the highest catalytic activity for formation of 2‐PMol (53.1%) and 2‐MP (42.9%). Mn species could cause the modulation of the acidic species of catalysts, improving the glycerol cyclocondensation with ED to 2‐PMol, and also acted as the catalytic centers for the hydrodehydration of 2‐PMol to 2‐MP. However, too many strong acidic sites could lead to ED self‐cyclocondensation to form a by‐product pyrazine. The optimum temperature was tested to be 380°C for the cyclocondensation over a 6%Mn‐SiO2‐Al2O3 catalyst. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:377–382, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21026
A Novel Asymmetric Synthesis of 3‐(1H‐Pyrrol‐1‐yl)‐Substituted β‐Lactams via a Bismuth Nitrate‐Catalyzed Reaction
Authors: Shaikh Aarif L. , Banik Bimal K.
Published: May 2012

The reaction of racemic α‐keto β‐lactams 5a–5c with the commercially available chiral compound trans‐4‐hydroxy‐L‐proline (6) in the presence of a catalytic amount of Bi(NO3)3⋅5 H2O in EtOH gave a diastereoisomer mixture of β‐lactams with a pyrrole ring at C(3) (7 to 12). This is the first enantioselective synthesis of optically active β‐lactams (=azetidin‐2‐ones) that possess a pyrrolyl residue at C(3), in a single step.
Radical Cyclization Reactions via Manganese(III) Acetate Leading to 2‐Thienyl‐Substituted Dihydrofuran Compounds
Authors: Biçer Emre , Yılmaz Mehmet , Karataş Melih , Pekel Ahmet Tarık
Published: May 2012

The 2‐thienyl‐substituted 4,5‐dihydrofuran derivatives 3–8 were obtained by the radical cyclization reaction of 1,3‐dicarbonyl compounds 1a–1f with 2‐thienyl‐substituted conjugated alkenes 2a–2e by using [Mn(OAc)3] (Tables 1–5). In this study, reactions of 1,3‐dicarbonyl compounds 1a–1e with alkenes 2a–2c gave 4,5‐dihydrofuran derivatives 3–5 in high yields (Tables 1–3). Also the cyclic alkenes 2d and 2e gave the dihydrobenzofuran compounds, i.e., 6 and 7 in good yields (Table 4). Interestingly, the reaction of benzoylacetone (=1‐phenylbutane‐1,3‐dione; 1f) with some alkenes gave two products due to generation of two stable carbocation intermediates (Table 5).
Synthesis of a Novel C2‐Symmetric Bis‐oxazoline (=Bis[4,5‐dihydrooxazole]) and Its Application as Chiral Ligand in Asymmetric Transition Metal Catalysis
Authors: Gök Yaşar , Van der Eycken Johan
Published: May 2012

The new C2‐symmetric bis‐oxazoline (=bis[4,5‐dihydrooxazole]) 2 with a chiral trans‐(2R,3R)‐2,3‐bis(3,5‐diphenylphenyl)cyclopropylidene (=trans‐(2R,3R)‐2,3‐bis([1,1′: 3′,1″‐terphenyl]‐5′‐yl)cyclopropylidene) backbone was efficiently synthesized (Scheme). All synthetic steps were easy to perform and led to the desired product in good overall yields. Compound 2 was tested and compared as ligand in several enantioselective catalytic reactions such as palladium(0)‐catalyzed enantioselective allylic alkylations and copper(I)‐catalyzed enantioselective cyclopropanations and aziridinations.
Femtosecond laser microstructuring for polymeric lab‐on‐chips
Authors: Eaton Shane M. , De Marco Carmela , Martinez‐Vazquez Rebeca , Ramponi Roberta , Turri Stefano , Cerullo Giulio , Osellame Roberto
Published: May 2012

This paper provides an overview of femtosecond laser microfabrication in polymeric materials, with emphasis on lab‐on‐chip applications. Due to the nonlinear interaction of femtosecond laser pulses with polymers, laser‐induced modifications are localized to the focal volume, enabling high resolution patterning in 3D. Femtosecond laser microfabrication offers unmatched versatility in fabricating surface microchannels and diffractive optics by means of laser ablation, buried optical waveguides and micro‐optics through refractive index modification and complex 3D microstructures in photoresists by two‐photon polymerization. Femtosecond laser microfabrication technology opens the door to fabricating integrated lab‐on‐chip devices with a single tool. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Tailoring the spectral response of liquid waveguide diagnostic platforms
Authors: Zhao Yue , Phillips Brian , Ozcelik Damla , Parks Joshua , Measor Philip , Gulbransen David , Schmidt Holger , Hawkins Aaron R.
Published: May 2012

Liquid filled waveguides that form the basis for on‐chip biophotonics diagnostic platforms have primarily found application in fluorescence and Raman spectroscopy experiments that require sensitive discrimination between weak analyte signals and a variety of background signals. Primary sources of background signal can include light from excitation sources (strong, narrow frequency band) and photoluminescence generated in waveguide cladding layers (weak, wide frequency band). Here we review both solid and liquid core filtering structures which are based on anti‐resonant reflection that can be integrated with waveguides for attenuating undesirable optical bands. Important criteria to consider for an optimized biosensor include cladding layer materials that minimize broad‐spectrum photoluminescence and optimize layer thicknesses for creating a desired spectral response in both solid and liquid guiding layers, and a microfabrication process capable of producing regions with variable spectral response. New results describing how spurious fluorescence can be minimized by optimized thermal growth conditions and how liquid‐core filter discrimination can be tuned with liquid core waveguide length are presented. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
11α hydroxylation of 16α, 17‐epoxyprogesterone in biphasic ionic liquid/water system by Aspergillus ochraceus
Authors: Mao Shuhong , Hua Boyuan , Wang Na , HU Xiaojie , Ge Zhijiang , Li Yanqing , Liu Sha , Lu Fuping
Published: May 2012

BACKGROUND: The improved efficiency of steroid biotransformation using the biphasic system is generally attributed to the positive effect on the solubility of substrate in aqueous media. A promising alternative for the application of organic solvents in biphasic systems is the use of ionic liquids (ILs). This study aims to investigate the applicability of the biphasic ILs/water system for 11α hydroxylation of 16α, 17‐epoxyprogesterone (HEP) by Aspergillus ochraceus.

RESULTS: Of the seven ILs tested, [C3mim][PF6] exhibited the best biocompatibility, with markedly improved biotransformation efficiency. In the [C3mim][PF6]‐based biphasic system, substrate conversion reached 90% under the condition in which buffer pH, volume ratio of buffer to ILs, cell concentration, and substrate concentration were 4.8, 10/1, 165 g L−1 and 20 g L−1, respectively. This is more efficient than that of the monophasic aqueous system. The effects of the cations and anions of these ILs on the 11α hydroxylation of 16α, 17‐epoxyprogesterone (HEP) by A. ochraceus is also discussed.

CONCLUSION: The above results showed that IL/water biphasic system improved the efficiency of 11α hydroxylation of 16α, 17‐epoxyprogesterone (HEP) by A. ochraceus, thus suggesting the potential industrial application of ILs‐based biphasic systems for steroid biotransformation. © 2012 Society of Chemical Industry
Pilot‐scale anaerobic/anoxic/oxic/oxic biofilm process treating coking wastewater
Authors: Zhou Xin , Li Yaxin , Zhao Yi , Yue Xiuping
Published: May 2012

BACKGROUND: Biological treatment efficiency of coking wastewater is rather poor, especially for chemical oxygen demand (COD) and ammonia‐nitrogen (NH$_{4}^{+}$‐N) removal due to its complex composition and high toxicity.

RESULTS: A pilot‐scale anaerobic/anoxic/oxic/oxic (A2/O2) biofilm system has been developed to treat coking wastewater, focusing attention on the COD and NH$_{4}^{+}$‐N removal efficiencies. Operational results over 239 days showed that hydraulic retention time (HRT) of the system had a great impact on simultaneous removals of COD and NH$_{4}^{+}$‐N. At HRT of 116 h, total removal efficiencies of COD and NH$_{4}^{+}$‐N were 92.3% and 97.8%, respectively, reaching the First Grade discharge standard for coking wastewater in China. Adequate HRT, anoxic removal of refractory organics and two‐step aerobic bioreactors were considered to be effective measures to obtain satisfactory coking effluent quality using the A2/O2 biofilm system. The correlation between removal characteristics of pollutants and spatial distributions of biomass along the height of upflow bioreactors was also revealed.

CONCLUSION: The study suggests that it is feasible to apply the A2/O2 biofilm process for coking wastewater treatment, achieving desirable effluent quality and steady process performance. © 2012 Society of Chemical Industry
Famotidine suppresses osteogenic differentiation of tendon cells in vitro and pathological calcification of tendon in vivo
Authors: Yamamoto Kenichi , Hojo Hironori , Koshima Isao , Chung Ung‐il , Ohba Shinsuke
Published: May 2012

Heterotopic ossification or calcification follows any type of musculoskeletal trauma and is known to occur after arthroplasties of hip, knee, shoulder, or elbow; fractures; joint dislocations; or tendon ruptures. Histamine receptor H2 (Hrh2) has been shown to be effective for reducing pain and decreasing calcification in patients with calcifying tendinitis, which suggested that H2 blockers were effective for the treatment of tendon ossification or calcification. However, the detailed mechanisms of its action on tendon remain to be clarified. We investigated the mechanisms underlying H2 blocker‐mediated suppression of tendon calcification, with a focus on the direct action of the drug on tendon cells. Famotidine treatment suppressed the mRNA expressions of Col10a1 and osteocalcin, ossification markers, in a tendon‐derived cell line TT‐D6, as well as a preosteoblastic one MC3T3‐E1. Both of the cell lines expressed Hrh2; histamine treatment induced osteocalcin expression in these cells. Famotidine administration suppressed calcification in the Achilles tendon of ttw mice, a mouse model of ectopic ossification. These data suggest that famotidine inhibits osteogenic differentiation of tendon cells in vitro, and this inhibition may underlie the anti‐calcification effects of the drug in vivo. This study points to the use of H2 blockers as a promising strategy for treating heterotopic ossification or calcification in tendon, and provides evidence in support of the clinical use of famotidine. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1958–1962, 2012
Evaluation of Citrus aurantifolia peel and leaves extracts for their chemical composition, antioxidant and anti‐cholinesterase activities
Authors: Loizzo Monica Rosa , Tundis Rosa , Bonesi Marco , Menichini Federica , De Luca Damiano , Colica Carmela , Menichini Francesco
Published: May 2012

BACKGROUND: The replacement of synthetic antioxidants by safe natural antioxidants fosters research on the screening of vegetables and food as sources of new antioxidants. Moreover, oxidative degeneration of cells is associated with neurodegenerative diseases such as Alzheimer's disease. On the basis of these considerations this work aimed to investigate the antioxidant properties [by using the diphenyl picryl hydrazyl, 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) and ferric reducing ability of plasma assays, and the β‐carotene bleaching test] and the anti‐cholinesterase activity of Citrus aurantifolia peel and leaves from different areas of growth.

RESULTS: Methanol extracts of the peel and leaves demonstrated the strongest radical scavenging activity. A similar trend was observed with the reducing ability, with values from 112.1 to 146.0 µmol L−1 Fe(II) g−1. The relationship between phenol and flavonoid contents and antioxidant activity was statistically investigated. Based on analysis by high‐performance liquid chromatography, the most abundant flavonoids found in C. aurantifolia extracts were apigenin, rutin, quercetin, kaempferol and nobiletin. n‐Hexane fractions of both peel and leaves showed a good acetylcholinesterase inhibitory activity with IC50 values in the range 91.4‐107.4 µg mL−1. Gas chromatography‐mass spectrometry analysis revealed the presence of monoterpenes and sesquiterpenes as most common components.

CONCLUSION: The findings of this study suggest a potential use of C. aurantifolia peel and leaves for supplements for human health. Copyright © 2012 Society of Chemical Industry
The incidence of metastasis from cutaneous squamous cell carcinoma and the impact of its risk factors
Authors: Brougham Nicholas D.L.S. , Dennett Elizabeth R. , Cameron Rujuta , Tan Swee T.
Published: May 2012

Background

Cutaneous squamous cell carcinoma (cSCC), the most common cancer capable of metastasis, has variable reported metastatic rates and the impact of individual risk factors for metastasis is unknown.

Methods

This study examined pathology records of excised cSCC over a 10‐year period. Uni‐variate and multi‐variate analyses including patient demographics, maximum clinical diameter (MCD), anatomical sub‐site, histological differentiation, perineural invasion (PNI), and lymphovascular invasion (LVI) of the lesion were performed. The primary endpoint was time to metastasis.

Results

Six thousand one hundred sixty four patients (median age 74 years) underwent excision of 8,997 primary cSCC. During the median follow‐up of 70 months, the metastatic rate of cSCC was 1.9–2.6%. Multi‐variate analysis showed that MCD (hazards ratio 1.41 [95% CI 1.25–1.60] P < 0.001), PNI (5.29; P < 0.0001), poor histological differentiation (4.26; P < 0.0001), location in the ear and retro‐auricular area (3.31 [1.17–9.33]; P = 0.0024), cheek (3.18 [1.15–8.81]; P = 0.026), and lip (4.84; P = 0.009) increased the risk of metastasis.

Conclusions

We show a 1.9–2.6% metastatic rate for cSCC with MCD, histologic differentiation, PNI, and certain anatomical sub‐sites being independent risk factors for metastasis. A prospective study on our proposed risk stratification scheme based on these parameters may lead to identification of high‐risk lesions that would benefit from more intensive treatment and/or routine post‐operative follow‐up. J. Surg. Oncol. 2012; 106:811–815. © 2012 Wiley Periodicals, Inc.
A methodology to investigate the wear of blast furnace hearth carbon refractory lining
Authors: Silva S. N. , Vernilli F. , Justus S. M. , Longo E. , Baldo J. B. , Varela J. A. , Lopes J. M. G.
Published: May 2012

In this work it is presented a methodology applied by Companhia Siderúrgica Nacional (CSN, Brazil) in order to assess its blast furnace 3 carbon refractory hearth lining conditions. The aim of the investigation was the gathering of critical data base for blast furnace refractories life cycle follow up and eventual repair decision taking.

The sample drilling locations were chosen around the tap holes and hearth bottom areas. The advancing drilling depths were based on local temperature profiles. The isotherm limit of 500 °C was elected as a control parameter to assess the critical carbon refractory condition. The guidelines for sampling and testing as well as the results obtained through the physical and chemical characterizations of the cored samples are presented. The condition of the refractory lining is discussed under the light of the different known wear mechanisms of blast furnace hearth carbon refractories.
Drug resistance associates with activation of Nrf2 in MCF‐7/DOX cells, and wogonin reverses it by down‐regulating Nrf2‐mediated cellular defense response
Authors: Zhong Yan , Zhang Fengyi , Sun Zhongying , Zhou Wei , Li Zhi‐Yu , You Qi‐Dong , Guo Qing‐Long , Hu Rong
Published: May 2012

Acquired resistance to doxorubicin (DOX) is a serious therapeutic problem in breast cancer patients. In this study, we investigated whether nuclear factor erythroid 2‐related factor 2 (Nrf2) was associated with drug resistant in DOX resistant MCF‐7 (MCF‐7/DOX) cells, and if wogonin, a flavonoid isolated from the root of Scutellaria baicalensis Georgi, could reverse drug resistance in MCF‐7/DOX cells. We found that the endogenous expression of Nrf2 as well as its target proteins heme oxygenase‐1 (HO‐1), NADP(H):quinone oxidoreductase (NQO) in MCF‐7/DOX cells was higher than that in MCF‐7 cells. Tert‐butylhydroquinone treatment increased the expression Nrf2, HO‐1, and NQO‐1, and enhanced resistance of MCF‐7 cells to DOX. Similarly, intracellular Nrf2 protein level was significantly decreased in MCF‐7/DOX cells and DOX resistance was partially reversed by Nrf2 siRNA. Wogonin downregulated the Nrf2‐dependent response and partly reversed DOX resistance in MCF‐7/DOX cells. These results suggested that activation of Nrf2 was associated with drug resistance in MCF‐7/DOX cells. Wogonin reversed drug resistance and its reversal mechanism might be due to the suppression of Nrf2 signaling pathway, indicating the feasibility of using Nrf2 inhibitors to increase efficacy of chemotherapeutic drugs. © 2012 Wiley Periodicals, Inc.
On the diffusion algorithm for density‐equalizing maps with piecewise constant initial data
Authors: Avinyó A. , Solà‐Morales J. , València M.
Published: May 2012

We mathematically analyze the diffusion‐based algorithm to produce maps with a given Jacobian, introduced independently by M. T. Gastner and M. E. J. Newman (2004) and ourselves (2003), but in particular cases where the initial density has line or angle discontinuities in the plane. In this situation, the conclusion reinforces the conjecture that the algorithm is always well‐posed, in accordance with its extensive numerical use in some areas of applied sciences (cartograms, sensor networks, computational grids, or image registration). Copyright © 2012 John Wiley & Sons, Ltd.
Antipodal linearly tapered slot antenna using unequal half‐circular defected sides for gain improvements
Authors: In Dae‐Myoung , Lee Min‐Jae , Kim Donghyun , Oh Chang‐Yul , Kim Young‐Sik
Published: May 2012

In this Letter, a new antipodal linearly tapered slot antenna (ALTSA) with unequal half‐circular slots (UHCS) embedded on both edge‐sides is proposed to improve an antenna gain. The proposed antenna operates over the frequency band from 3.1 GHz to more than 10.6 GHz, which is assigned to Ultra‐Wideband wireless communications. The proposed antenna has been improved in a gain and reduced to backward radiation due to the unequal half‐circular slots on the ALTSA. The measured antenna gains are improved by up to 3.5 dB. The side lobe levels are lowered by about −14.8 and −7.2 dB in the E‐ and H‐planes at 7 GHz, respectively. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1963–1965, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26942
Simplified approach to low‐cost multiparameter monitoring based on low frequency polarization modulation
Authors: Floridia C. , Simões G.C. C. P. , Bezerra E. W. , Feres M. M. , Romero M. A.
Published: May 2012

We experimentally revisit a technique of low‐cost multiparameter monitor for optical performance monitoring based on low frequency polarization modulation. A simplified calibration procedure, which significantly reduces the mathematical complexity and processing effort is proposed. Validation is achieved by carrying out relative optical power, wavelength, and differential group delay measurements. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1820–1824, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26956
Compact monopole antenna design for WLAN/WiMAX triple‐band operations
Authors: Yoon Joong Han , Rhee Young Chul , Jang Yeon Kil
Published: May 2012

A novel design of a simple microstrip‐fed monopole antenna well suited to wireless local area network (WLAN)/worldwide interoperability for microwave access (WiMAX) application for triple‐band operation is proposed in this article. The proposed antenna consists of one branch strip, two hook‐shaped strips, an asymmetrical ground plane, and a rectangular slit in the ground plane. Through the proper selection of the dimensions as well as arrangement of the strips, desired resonant modes excited at 2.35/3.65/5.375 GHz with a less than −10‐dB input impedance frequency response can be achieved. Prototypes of the proposed antenna were fabricated and experimentally measured, and an acceptable agreement between the measurement and simulation results was achieved. The numerical and experimental results demonstrate that the proposed antenna satisfies the −10‐dB impedance bandwidth requirement while covering the WLAN and WiMAX bands simultaneously. Meanwhile, the 2D radiation patterns and 3D gain performance of the antenna in the operation bands were also observed and discussed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1838–1846, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26963
A fully integrated rf front end for DVB‐SH
Authors: García‐Vázquez Hugo , Khemchandani Sunil L. , Ramos‐Valido Dailos , Juanicorena Aitor , Luján‐Martínez Carmen , del Pino Javier
Published: May 2012

This article describes a RF front end for DVB‐SH (2.17–2.2 GHz) implemented in UMC CMOS 90 nm process. This receiver includes a low noise amplifier (LNA), a single‐to‐differential converter, and a mixer. The LNA is based on cascode topology combined with a narrow band impedance matching and LC tank load. The single‐to‐differential converter generates a pair of differential output signals from a single input, which have balanced amplitude and phase. This converter is followed by a Gilbert cell based quadrature mixer. The measurements show a conversion gain of 15.7–15.5 dB, an input return loss (S11) of −12 dB, and an output compression point of 1.92 dBm. This receiver has a simulated noise figure of 2.2 dB. This combination draws 22 mW from a 1.2‐V supply. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1944–1949, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26974
Proximity study of a conformal UWB directional antenna on water pipe
Authors: Gaetano Domenico , Ammann Max J. , McEvoy Patrick , John Matthias , Keating Louise , Horgan Frances
Published: May 2012

A preliminary study on the conformal properties of an antipodal exponentially tapered antenna placed on the surface of a flow meter system in the UWB range is presented. It was observed that the water effect can be mitigated by shifting the antenna away from the pipe surface. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1982–1986, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26979
High‐resolution human diffusion tensor imaging using 2‐D navigated multishot SENSE EPI at 7 T
Authors: Jeong Ha‐Kyu , Gore John C. , Anderson Adam W.
Published: May 2012

The combination of parallel imaging with partial Fourier acquisition has greatly improved the performance of diffusion‐weighted single‐shot EPI and is the preferred method for acquisitions at low to medium magnetic field strength such as 1.5 or 3 T. Increased off‐resonance effects and reduced transverse relaxation times at 7 T, however, generate more significant artifacts than at lower magnetic field strength and limit data acquisition. Additional acceleration of k‐space traversal using a multishot approach, which acquires a subset of k‐space data after each excitation, reduces these artifacts relative to conventional single‐shot acquisitions. However, corrections for motion‐induced phase errors are not straightforward in accelerated, diffusion‐weighted multishot EPI because of phase aliasing. In this study, we introduce a simple acquisition and corresponding reconstruction method for diffusion‐weighted multishot EPI with parallel imaging suitable for use at high field. The reconstruction uses a simple modification of the standard sensitivity‐encoding (SENSE) algorithm to account for shot‐to‐shot phase errors; the method is called image reconstruction using image‐space sampling function (IRIS). Using this approach, reconstruction from highly aliased in vivo image data using 2‐D navigator phase information is demonstrated for human diffusion‐weighted imaging studies at 7 T. The final reconstructed images show submillimeter in‐plane resolution with no ghosts and much reduced blurring and off‐resonance artifacts. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
A staggered nonlocal multiscale model for a heterogeneous medium
Authors: Fish Jacob , Jiang Tao , Yuan Zheng
Published: May 2012

A staggered nonlocal multiscale model for a heterogeneous medium is developed and validated. The model is termed as staggered nonlocal in the sense that it employs current information for the point under consideration and past information from its local neighborhood. For heterogeneous materials, the concept of phase nonlocality is introduced by which nonlocal phase eigenstrains are computed using different nonlocal phase kernels. The staggered nonlocal multiscale model has been found to be insensitive to finite element mesh size and load increment size. Furthermore, the computational overhead in dealing with nonlocal information is mitigated by superior convergence of the Newton method. Copyright © 2012 John Wiley & Sons, Ltd.
Modification of epoxy–anhydride thermosets using a hyperbranched poly(ester‐amide): I. Kinetic study
Authors: Fernández‐Francos Xavier , Rybak Andrzej , Sekula Robert , Ramis Xavier , Serra Angels
Published: May 2012

An epoxy‐anhydride formulation used for the coating of electrical devices was modified with a commercially available hyperbranched poly(ester‐amide), Hybrane™ S2200, in order to improve the thermal degradability of the resulting thermoset and thus facilitate the recovery of substrate materials after use of the component. The curing kinetics of the unmodified and modified formulations were studied in detail with differential scanning calorimetry, Fourier transform infrared spectroscopy and rheology. The results suggest that S2200 gets incorporated into the network structure and the curing kinetics are accelerated by the presence of hydroxyl groups from S2200. Copyright © 2012 Society of Chemical Industry
MALDI‐TOF‐MS analysis of sialylated glycans and glycopeptides using 4‐chloro‐α‐cyanocinnamic acid matrix
Authors: Selman Maurice H. J. , Hoffmann Marcus , Zauner Gerhild , McDonnell Liam A. , Balog Crina I. A. , Rapp Erdmann , Deelder André M. , Wuhrer Manfred
Published: May 2012

For MALDI analysis of glycans and glycopeptides, the choice of matrix is crucial in minimizing desialylation by mass spectrometric in‐source and metastable decay. Here, we evaluated the potential of 4‐chloro‐α‐cyanocinnamic acid (Cl‐CCA) for MALDI‐TOF‐MS analysis of labile sialylated tryptic N‐glycopeptides and released N‐ and O‐glycans. Similar to DHB, but in contrast to CHCA, the Cl‐CCA matrix allowed the analysis of sialylated N‐glycans and glycopeptides in negative ion mode MALDI‐TOF‐MS. Dried droplet preparations of Cl‐CCA provided microcrystals with a homogeneous spatial distribution and high shot‐to‐shot repeatability similar to CHCA, which simplified the automatic measurement and improved the resolution and mass accuracy. Interestingly, reflectron‐positive ion mode analysis of 1‐phenyl‐3‐methyl‐5‐pyrazolone (PMP)‐labeled O‐glycans with Cl‐CCA revealed more complete profiles than with DHB and CHCA. In conclusion, we clearly demonstrate the high potential of this rationally designed matrix for glycomics and glycoproteomics.
Close proximity of phosphorylation sites to ligand in the phosphoproteome of the extreme thermophile Thermus thermophilusHB8
Authors: Takahata Yoshio , Inoue Masao , Kim Kwang , Iio Yota , Miyamoto Masaaki , Masui Ryoji , Ishihama Yasushi , Kuramitsu Seiki
Published: May 2012

We performed phosphoproteome analysis of proteins from the extremely thermophilic Gram‐negative eubacterium Thermus thermophilus HB8 using gel‐free mass spectrometric method. We identified 52 phosphopeptides from 48 proteins and determined 46 phosphorylation sites: 30 on serine, 12 on threonine, and 4 on tyrosine. The identified phosphoproteins are known to be involved in a wide variety of cellular processes. To help elucidate the functional roles of these phosphorylation events, we mapped the phosphorylation sites on the known tertiary structures of the respective proteins. In all, we succeeded in mapping 46 sites (approximately 88%) on the corresponding structures. Most of the phosphorylation sites were found to be located on loops and terminal regions of the secondary structures. Surprisingly, 28 of these sites were situated at or near the active site of the enzyme. In particular, 18 sites were within 4 Å of the ligand, including substrate or cofactor. Such structural locations suggest direct effects of the phosphorylation on the binding of ligand in addition to inducing a conformational change. Interestingly, 19 of these 28 phosphorylation sites were situated near the phosphate moiety of a substrate or cofactor. In oligomeric proteins, 5 phosphorylation sites were found at the subunit interface. Based on these results, we propose a regulatory mechanism that involves Ser/Thr/Tyr phosphorylation in T. thermophilus HB8.
Digital microfluidic hydrogel microreactors for proteomics
Authors: Luk Vivienne N. , Fiddes Lindsey K. , Luk Victoria M. , Kumacheva Eugenia , Wheeler Aaron R.
Published: May 2012

Proteolytic digestion is an essential step in proteomic sample processing. While this step has traditionally been implemented in homogeneous (solution) format, there is a growing trend to use heterogeneous systems in which the enzyme is immobilized on hydrogels or other solid supports. Here, we introduce the use of immobilized enzymes in hydrogels for proteomic sample processing in digital microfluidic (DMF) systems. In this technique, preformed cylindrical agarose discs bearing immobilized trypsin or pepsin were integrated into DMF devices. A fluorogenic assay was used to optimize the covalent modification procedure for enzymatic digestion efficiency, with maximum efficiency observed at 31 μg trypsin in 2‐mm diameter agarose gel discs. Gel discs prepared in this manner were used in an integrated method in which proteomic samples were sequentially reduced, alkylated, and digested, with all sample and reagent handling controlled by DMF droplet operation. Mass spectrometry analysis of the products revealed that digestion using the trypsin gel discs resulted in higher sequence coverage in model analytes relative to conventional homogenous processing. Proof‐of‐principle was demonstrated for a parallel digestion system in which a single sample was simultaneously digested on multiple gel discs bearing different enzymes. We propose that these methods represent a useful new tool for the growing trend toward miniaturization and automation in proteomic sample processing.
Calculation of Particle Size Distributions from Ultrasonic Measurements: A Mineral Slurry Case Study
Authors: Coghill Peter John , Millen Michael
Published: May 2012

Ultrasonic transmission measurements have been used extensively to determine the particle size of solids in slurries. This case study examines the application of mathematical inversion techniques to the determination of the particle size distribution of a mineral slurry from data collected at a minerals processing plant. A new mathematical inversion technique, based on an extension of modified Chahine iteration combined with the principle of maximum entropy has been developed. Four algorithms were constructed and used to calculate particle size distributions from synthetic and raw plant data. These incorporated modified Chahine iteration and its extension, together with two different approaches to applying a density measurement constraint on the particle size distribution. In general the algorithms performed well with regression errors below 3 %. The correlation coefficients and slopes for this technique were 0.86 and 1.35 for the weight fraction of particles less than 75 microns when compared with the laser diffraction analysis. A better match was obtained for the plant data by using the new inversion technique, into which the principle of maximum entropy has been incorporated whereas this was not the case with the synthetic data, illustrating the need to match the inversion technique to the problem.