bluuebunny/crossref_metadata_2025 huggingface dataset:
Acrylonitrile/vinyl acetate copolymer nanofibers with different vinylacetate content
Authors: Cetiner Suat , Sen Selda , Arman Burcu , Sarac A. Sezai
Published: May 2012

In this study, free radical copolymerization of acrylonitrile (AN)–vinyl acetate (VAc) was performed for five different feed ratio of VAc (wt %) by using ammonium persulfate (APS) in the aqueous medium. The effect of VAc content on the spectrophotometric and thermal properties of AN–VAc copolymers was investigated by Fourier Transform Infrared–Attenuated Total Reflectance spectrophotometer (FTIR–ATR), differential scanning calorimeter (DSC), and thermal gravimetric analyzer (TGA). Thermal stability of homopolymer of AN is improved after being copolymerized. The electrospun P(AN‐co‐VAc) nanofibers were fabricated and the effect of VAc content on the morphologic properties of nanofibers was studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The viscosity of the solution had a significant effect on P(AN‐co‐VAc) electrospinning and the nanofiber morphology. The average diameters of P(AN‐co‐VAc) nanofibers decreased 3.4 times with increasing feed ratio of VAc wt %. The P(AN‐co‐VAc) electrospun nanofiber mats, with the feed ratio of 30 wt % VAc, can be used as a nanofiber membrane in filtration and as a carbon nanofiber precursor for energy storage applications due to high surface to volume ratio, high thermal stability, homogeneous, and thinner nanofiber distribution. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Similarity and grouping of perlite and zeolite abrasive fillers: A replacement test
Authors: Strzemiecka Beata , Héberger Károly , Voelkel Adam
Published: May 2012

Inverse gas chromatography was used to estimate surface activity expressed by the dispersive component of the surface free energy, γ, as well as parameters KA and KD describing surface ability to act as electron acceptor and donor, respectively. These parameters characterize the ability of the surface to specific interactions. The method was also applied to describe the magnitude of filler‐phenolic resin interaction by Flory‐Huggins parameter, χ′23. Granulation, surface area and porosity were also determined. The minimum number of parameters required to complete characterization of filler properties has been selected by principal component analysis. The usefulness of the selection for the abrasive industry has been proven. Moreover, the similarities and deviations from “an average” filler was determined by chemometric methods. Principal component analysis (PCA) and a novel procedure based on sum of ranking differences (SRD) were successfully applied for selection of the best fillers, and of advantageous parameters for characterization of the fillers. Similar and diverse fillers have been chosen based on clustering pattern by PCA and SRD. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation and characterization of poly(vinyl alcohol)‐poly(vinyl pyrrolidone) blend: A biomaterial with latent medical applications
Authors: Bernal Andres , Kuritka Ivo , Saha Petr
Published: May 2012

Aqueous solutions of poly(vinyl alcohol) and poly(vinyl pyrrolidone) are blended and films are produced by casting method with the further intention of being used as bio‐materials with latent medical application. Glutaraldehyde, 4,4′‐diazido‐2,2′‐stilbenedisulfonic acid disodium salt tetra‐hydrate are used as crosslinker agents, whereas lactic acid is the plasticizer in the blend. The obtained films are characterized by differential scanning calorimetry (DSC), mechanical properties, swelling and solubility behavior. DSC measurements show that the blends exhibit a single glass transition temperature indicating that they are miscible, even in the presence of the plasticizer and crosslinker agents. By the combination of all mentioned additives, a relevant enhancement of the swelling is observed, accompanied by a stabilization of the solubility during the tested time. Finally, mechanical properties show an appropriate performance in the studied parameters. As a consequence, the obtained films could be suitable for use as medium or long‐term implants. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
The formation of asymmetric polystyrene/saponite composite nanoparticles via miniemulsion polymerization
Authors: Tong Zhaohui , Deng Yulin
Published: May 2012

The synthesis of asymmetric spherical nanoparticles has attracted great interest because their anisotropic structure can be used as unique building blocks for constructing advanced materials. In this article, we report the formation of hemispherical or truncated polystyrene/nanosaponite composite particles via one‐pot miniemulsion polymerization. It was found that the morphology of final composite latex particles strongly depends on the size of the nanoclay and its surface properties. Hemisphere or truncated sphere is the dominant morphology if the size of the nanoclay is larger than 100 nm. With the increase of the nanoclay content (up to 30 wt %), the fraction of hemispherical or truncated polystyrene/nanosaponite composite latex particles increased accordingly. The formation of hemispherical particles is possibly attributed to either the asymmetric growth of polymer chains on one side of the hydrophobically modified clay or the mechanical peeling‐off of large spherical particles between polymer and saponite. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Mechanical and thermal properties of graphite nanoplatelets reinforced polyarylene ether nitriles/bisphthalonitrile IPN system
Authors: Lei Yajie , Zhao Rui , Yang Xulin , Liu Xiaobo
Published: May 2012

A new type of graphite nanoplatelets (GN) reinforced polyarylene ether nitriles (PEN)/bisphthalonitrile (BPh) interpenetrating polymer network with high strength and high toughness was synthesized and characterized. The results showed that GN and PEN had obvious synergistic effect on its properties of resulted BPh composites. Compared to pure BPh, with a loading of 10 wt % PEN and 10 wt % GN, the obtained composites exhibited excellent mechanical properties. In these systems, the flexural toughness and strength of BPh resin could be enhanced with the incorporation of PEN; meanwhile, GN could further improve the flexural modulus and thermal stability lowered by PEN. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis and characterization of the new cellulose derivative films based on the hydroxyethyl cellulose prepared from esparto “stipa tenacissima” cellulose of Eastern Morocco. II. Esterification with acyl chlorides in a homogeneous medium
Authors: El idrissi Abderahmane , El barkany Soufian , Amhamdi Hassan , Maaroufi Abdel‐Karim
Published: May 2012

Esparto “Stipa tenacissima” cellulose esters derivatives: HECA‐COOC4H8COOC2H5, HECA‐COOC8H16COOC2H5, and HECA‐COOC6H4COOC2H5 were successfully prepared in Tetrahydrofuran (THF)/triethylamine system with a degree of substitution (DS), respectively, DSAD‐Et=0.32, DSSB‐Et=0.22, and DSTRP‐Et=0.50 using hydroxyethyl cellulose acetate (HECA; DSAC=0.50) as intermediate product, and we avoided the drawbacks of cellulose solubility. The structural modifications were investigated using Fourier transform infrared spectroscopy (FTIR), Proton nuclear magnetic resonance (1H‐NMR), Carbon‐13 nuclear magnetic resonance (13C‐NMR), and Distortionless Enhancement by Polarization Transfer 135° (DEPT‐135). The results from these analyses revealed the presence of the characteristic groups indicating that the grafting reaction was successful. The crystallinity and the structure order changes during the esterification reactions were recorded by X‐ray diffraction (XRD), it is found that the crystallinity degree decrease from 63.1% for Esparto “Stipa tenacissima” cellulose to 27.74% for HECA. The thermal stability of the esterified and unmodified cellulose samples was studied by thermogravimetric analysis (TGA)‐differential thermal analysis (DTA); the modified HECA exhibits a decrease in thermal stability relatively to the unmodified HECA, and this may be related to the groups grafted. The resulted cellulose esters HECA‐Px (x = 1, 2, or 3) were soluble in THF and present an amorphous structure justified by XRD spectra. It was noted by TGA‐DTA analysis that the cellulose esters with low melting range were proved as thermoplastic polymers. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
EICOSANOIDS MEDIATE CELLULAR IMMUNE RESPONSE AND PHENOLOXIDASE REACTION TO VIRAL INFECTION IN ADULT Pimpla turionellae
Authors: Büyükgüzel Ender
Published: May 2012

Nodulation is the predominant insect cellular immune response to microbial infections. We posed the hypothesis that parasitoid insects in their adulthood express melanotic nodulation reactions to viral challenge and that eicosanoids mediate nodulation reactions and phenoloxidase (PO) activation in response to viral challenge. To test this idea, we injected Pimpla turionellae adults with indomethacin, a nonsteroidal anti‐inflammatory drug, immediately prior to intrahemocoelic injection of Bovine herpes simplex virus‐1 (BHSV‐1). Treating newly emerged adults of P. turionellae with BHSV‐1 induced nodulation reactions, and decreased PO activity at high viral doses. Relative to vehicle‐treated controls, indomethacin‐treated adults produced significantly reduced numbers of nodules following viral infection (down from approximately 21 nodules per adult to less than six nodules per adult). In addition to injection treatments, increasing dietary indomethacin dosages (from 0.01% to 0.1%) were associated with decreasing nodulation (by six‐fold) and PO (by about three‐fold) reactions to BHSV‐1 injection. Wasp adults orally fed with the lowest dietary indomethacin concentration (0.001%) expressed significantly increased PO activity (1.45 unit/min/mg protein) while nodulation reaction was not affected in response to viral challenge compared to control adults. We infer from these findings that cyclooxygenase (COX) products, at least prostaglandins, mediate nodulation response and PO action to viral infection in adults of these highly specialized insects.
Selective Cycloaddition of Tetracyanoethene (TCNE) and 7,7,8,8‐Tetracyano‐p‐quinodimethane (TCNQ) to Afford meso‐Substituted Phenylethynyl Porphyrins
Authors: Koszelewski Dominik , Nowak‐Król Agnieszka , Gryko Daniel T.
Published: May 2012

π‐Extended TCBD‐porphyrins that contained a 1,1,4,4‐tetracyanobuta‐1,3‐diene unit were prepared by a highly efficient [2+2] cycloaddition of tetracyanoethene (TCNE) or 7,7,8,8‐tetracyano‐p‐quinodimethane (TCNQ) with meso‐substituted trans‐A2B2‐porphyrins that contained two phenylethynyl groups, followed by a retro‐electrocyclization reaction. Depending on the electronic properties of the arylethynyl groups, the cycloaddition reaction took place exclusively on either one or two ethynyl moieties with high yield. The addition of TCNQ proceeded with complete regioselectivity. The resulting π‐expanded TCBD‐porphyrins had a hypsochromically shifted Soret band and showed unique, broad absorption in the visible region.
Connectivity Preserving Flocking without Velocity Measurement
Authors: Wang Lin , Wang Xiaofan , Hu Xiaoming
Published: May 2012

In this paper, we address the design of a decentralized controller for connectivity‐preserving flocking, where each agent only can access to the position information of the agents within its sensing zone. An output vector, based on the position information alone, is constructed to replace the role of velocity, and some bounded attractive and repulsive forces are integrated together to design the controller. We prove that the controller not only synchronizes all agents in a stable formation, but also enables collision avoidance and connectivity preserving all of the time, when the initial condition meets certain requirements. Moreover, a leader‐follower method is used to guide the group to a desired direction, where the followers can sense the leader only if the distance between them is less than the communication radius.
Notes on interval estimation of the gamma correlation under stratified random sampling
Authors: Lui Kung‐Jong , Chang Kuang‐Chao
Published: May 2012

We have developed four asymptotic interval estimators in closed forms for the gamma correlation under stratified random sampling, including the confidence interval based on the most commonly used weighted‐least‐squares (WLS) approach (CIWLS), the confidence interval calculated from the Mantel‐Haenszel (MH) type estimator with the Fisher‐type transformation (CIMHT), the confidence interval using the fundamental idea of Fieller's Theorem (CIFT) and the confidence interval derived from a monotonic function of the WLS estimator of Agresti's α with the logarithmic transformation (MWLSLR). To evaluate the finite‐sample performance of these four interval estimators and note the possible loss of accuracy in application of both Wald's confidence interval and MWLSLR using pooled data without accounting for stratification, we employ Monte Carlo simulation. We use the data taken from a general social survey studying the association between the income level and job satisfaction with strata formed by genders in black Americans published elsewhere to illustrate the practical use of these interval estimators.
Application of a 22L scale membrane bioreactor and cross‐flow ultrafiltration to obtain purified chondroitin
Authors: Schiraldi Chiara , Alfano Alberto , Cimini Donatella , Rosa Mario De , Panariello Andrea , Restaino Odile F. , Rosa Mario De
Published: May 2012

Recently, the possibility of producing fructosylated chondroitin from the capsular polysaccharide of Escherichia coli O5:K4:H4, in fed‐batch and microfiltration experiments was assessed on a 2 L bioreactor. In this work, a first scale‐up step was set on a 22 L membrane reactor with modified baffles to insert ad hoc designed microfiltration modules permanently inside the bioreactor vessel. Moreover, the downstream polysaccharide purification process, recently established on the A¨︁KTA cross‐flow instrument, was translated to a UNIFLUX‐10, a tangential flow filtration system suitable for prepilot scale. In particular, the microfiltered permeates obtained throughout the fermentation, and the supernatant recovered from the centrifuged broth at the end of the process, were treated as two separate samples in the following ultrafiltration procedure, and the differences in the two streams and how these affected the ultrafiltration/diafiltration process performance were analysed. The total amount of K4 capsular polysaccharide was about 85% in the broth and 15% in the microfiltered permeates. However, the downstream treatment was more efficient when applied to the latter. The major contaminant, the lipopolysaccharide, could easily be separated by a mild hydrolysis that also results in the elimination of the unwanted fructosyl residue, which is linked to the C‐3 of glucuronic acid residues. The tangential ultrafiltration/diafiltration protocols developed in a previous work were effectively scaled‐up, and therefore in this research proof of principle was established for the biotechnological production of chondroitin from the wild‐type strain E. coli O5:K4:H4. The complete downstream procedure yielded about 80% chondroitin with 90% purity. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 28: 1012–1018, 2012
Satisfaction strength and intention to purchase a new product
Authors: Tudoran Ana Alina , Olsen Svein Ottar , Dopico Domingo C.
Published: May 2012

This study examines the role of satisfaction strength on the correspondence between reported satisfaction and intention to purchase a new product. The market testing underlying this study analyzes the market opportunities for a novel prototype. The research was conducted at a central location with 239 randomly selected consumers. Results indicate that (un)certainty, ambivalence, and importance cognitions and feelings significantly moderate the relationship between reported satisfaction and individuals' intention to purchase. For example, the association between consumers' reported satisfaction level and purchasing intention of the new product is weaker as uncertainty increases. Significant moderated‐mediation and mediated‐moderation effects were also found with Structural Equation Modelling. Judgments of ambivalence moderate the satisfaction–purchasing intention relationship through the mediating effect of importance. (Un)certainty fully mediates the moderating effect of importance on the satisfaction–purchasing intention link. The research validates the usefulness of assessing the satisfaction strength concept and illustrates its potential as a better predictor of intentions than satisfaction level alone. The study argues on the nomological validity of the satisfaction construct and reveals that assessment of satisfaction strength should support the management goal of identifying truly satisfied customers. Copyright © 2012 John Wiley & Sons, Ltd.
Does an iPod make you happy? An exploration of the effects of iPod ownership on life satisfaction
Authors: Cockrill Antje
Published: May 2012

The Apple iPod is currently the undisputed leading product in the global MP3 player market. This competitive advantage is due to the design, high functionality, and perhaps most importantly, the ‘cool factor’ which Apple has managed to obtain with its products. This study explores if owning an iPod (as opposed to another brand of MP3 player) makes a difference in the perception of general life satisfaction. Using Diener et al.'s generic satisfaction with life scale (SWLS) to measure the dependent variable life satisfaction, a model with the key concepts usage, benefits, peer influence, design, iPod phenomenon, and iPod bubble has been developed and tested in a variety of ways, including regression analysis. The sample consisted of a multinational sample of 240+ young adults, aged 18–35 years. The demographic profiles of iPod and non‐iPod owners were very similar, but for iPod owners, 23 per cent of the variance in overall life satisfaction is explained by the key concepts used in this research. Key influencing variables for iPod owners are peer influence and design. For non‐iPod owners, the amount of variance explained by the independent variables was negligible. iPod owners also considered their MP3 players to be much ‘cooler’ than did non‐iPod owners. This article considers the managerial implications of these findings for Apple and for competing brands. The social implications of these findings and their significance are also discussed, and several potential areas for further research are highlighted. Copyright © 2012 John Wiley & Sons, Ltd.
Plasmonic Trapping with a Gold Nanopillar
Authors: Wang Kai , Crozier Kenneth B.
Published: May 2012

An improved ability to manipulate nanoscale objects could spur the field of nanotechnology. Optical tweezers offer the compelling advantage that manipulation is performed in a non‐invasive manner. However, traditional optical tweezers based on laser beams focused with microscope lenses face limitations due to the diffraction limit, which states that conventional lenses can focus light to spots no smaller than roughly half the wavelength. This has motivated recent work on optical trapping based on the sub‐wavelength field distributions of surface plasmon nanostructures. This approach offers the benefits of higher precision and resolution, and the possibility of large‐scale parallelization. Herein, we discuss the fundamentals of optical manipulation using surface plasmon resonance structures. We describe two important issues in plasmonic trapping: optical design and thermal management strategies. Finally, we describe a surface plasmon nanostructure, consisting of a gold nanopillar that takes these issues into consideration. It is shown to enable the trapping and rotation (manual and passive) of nanoparticles. Methods by which this concept can be extended are discussed.
Controllable synthesis of well‐aligned CuO nanotube arrays using porous alumina templates
Authors: Zhu Y. F. , Zhou G. H. , Lin Y. B. , Liu L.
Published: May 2012

In order to further enhance the performance of CuO in currently existing applications, well‐aligned CuO nanotube arrays with different diameters were fabricated. During the synthesis process, porous anodic alumina films were fabricated, and then the synthesis of CuO nanotube arrays was realized by using the obtained porous anodic alumina films as templates. The morphology and structure of the obtained products has been confirmed by field‐emission scanning electron microscopy, transmission electron microscopy and X‐ray diffraction measurements. Due to the large surface area of the synthesized products, the prepared CuO nanotube arrays may have potential applications in catalyzing and gas sensing area.
Effect of anisotropic incidence and atomic arrangement of CoFe system magnetic thin films for the gigahertz frequency in the carousel sputtering method
Authors: Imaizumi Ryoichi , Munakata Makoto , Ohkoshi Masatoshi , Maki Kouichirou
Published: May 2012

To increase the uniaxial magnetic anisotropy in thin‐film materials is a key issue for micro‐magnetic devices driven at gigahertz frequencies. It is known that an especially large uniaxial magnetic anisotropy is induced only by the carousel sputtering method. In this paper, the atomic deposition process of CoFeB and CoFe films was analyzed by using a simulation of kinetic theory of gases. The results showed that the sputtered particles had markedly anisotropic incidence on the substrate, leading to different atomic distances with respect to the direction of incidence, resulting in a magnetioelastic effect. These sputtered particles with anisotropic incidence are a main cause of the higher uniaxial magnetic anisotropy of the films. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(6): 58–65, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10426
TLR‐mediated distinct IFN‐γ/IL‐10 pattern induces protective immunity against murine visceral leishmaniasis
Authors: Paul Joydeep , Karmakar Subir , De Tripti
Published: May 2012

Resistance to murine visceral leishmaniasis (VL) correlates with the development of an IFN‐γ predominant immune response. Beta1,4‐galactose terminal glycans are potent inducers of IFN‐γ. Here, we demonstrate the efficacy of a 29 kDa β1,4‐galactose terminal glycoprotein (GP29) of Leishmania donovani (LD) in an in vitro macrophage model and an in vivo mouse model of VL. GP29 induced splenic macrophages to release NO and ROS in appreciable amounts that resulted in effective parasite clearance from macrophages. This was associated with the toll‐like receptor (TLR)‐4 mediated IL‐12 induction and inhibition of TLR2‐mediated IL‐10 production. Two subcutaneous injections of GP29 at fortnightly intervals resulted in dominant IL‐12‐mediated IFN‐γ production and 100% animals were protected against a subsequent challenge with virulent LD parasites. Vaccinated mice showed a reversal of T‐cell anergy, significantly elevated expression of iNOS and a type‐1 IgG subclass response. Moreover, vaccinated mice downregulated arginase1 and IL‐10 expression but did not alter IL‐4 expression. The IFN‐γ/IL‐10 ratio regulated the intensity of the protective immune response. Experiments with IFN‐γ and IL‐10 knockout mice reiterated the role IL‐10 and IFN‐γ play in disease progression or resolution in the murine model of VL.
Perylenequinones: Isolation, Synthesis, and Biological Activity
Authors: Mulrooney Carol A. , O'Brien Erin M. , Morgan Barbara J. , Kozlowski Marisa C.
Published: May 2012

The perylenequinones are a class of natural products characterized by a pentacyclic conjugated chromophore giving rise to photoactivity. Potentially useful light‐activated biological activity, targeting protein kinase C (PKC), has been identified for several of the natural products. Recently discovered new members of this compound class, as well as several related phenanthro‐perylenequinones, are reviewed. Natural product modifications that improve biological profiles are outlined, as well as avenues for the total synthesis of analogs not available from the natural product series. An overview of structure/function relationships is provided.
Oxidative Ring Opening of 1,3‐Diarylbenzo[c]heterocycles Using m‐CPBA: Preparation of 1,2‐Diaroylbenzenes
Authors: Nandakumar Meganathan , Sivasakthikumaran Ramakrishnan , Mohanakrishnan Arasambattu K.
Published: May 2012

An unprecedented oxidative cleavage of benzo[c]heterocycles using m‐CPBA is reported. The reaction of 1,3‐diaryl benzo[c]heterocycles with m‐CPBA (meta‐chloroperoxybenzoic acid) at room temperature for 5 min led to the formation of 1,2‐diaroylbenzenes in good to excellent yields.
Determination of peimine and peiminine in Bulbus Fritillariae Thunbergii by capillary electrophoresis by indirect UV detection using N‐(1‐naphthyl)ethylenediamine dihydrochloride as probe
Authors: Liu Lihong , You Wenwei , Zheng Liujuan , Chen Feiyu , Jia Zhimin
Published: May 2012

A simple and inexpensive CE method was developed for the determination of peimine and peiminine. Because of the lack of an UV chromophore of peimine and peiminine, the detection method chosen was indirect UV detection, with N‐(1‐naphthyl)ethylenediamine dihydrochloride (NED) as the UV absorbing probe. It was thought that NED, a chromophoric ion, may form hydrogen bonding pairs with the analytes to cause significant changes in separation selectivity. Additionally, the hydrophobic interactions between analytes and the probe also play a crucial role in achieving a resolution between the two analytes. The analyses were carried out with a background electrolyte composed of 66% MeOH–ACN (1:1, v/v), 34% aqueous buffer containing 15 mM NaH2PO4, 2.5 mM NED, 4 mM H3PO4. MeOH–ACN mixtures used as organic modifiers can not only reduce the adsorption of NED to the capillary wall, but also decrease the baseline noise and drift. The method provided a linear response ranging from 5 to 200 μg/mL. The limits of detection (LODs) for peimine and peiminine were 3.9 and 4.1 μg/mL, respectively. The repeatabilities (n = 3) reached relative standard deviation values (RSDs) of 3.4 and 4.1% for the peak areas, 4.0 and 4.4% for the peak heights, and 0.29 and 0.30% for the migration time of peimine and peiminine, respectively. Regression equations revealed linear relationships (r = 0.9995–0.9996) between the peak area of each analyte and the concentration. The method developed was successfully applied to quantify peimine and peiminine in chloroform extracts of the ground Bulbus Fritillariae Thunbergii.
A rapid and simplified method for protein silver staining in polyacrylamide gels
Authors: Zhao Lijing , Liu Cong , Sun Yinpeng , Ban Liping
Published: May 2012

Silver staining is widely used to detect protein in polyacrylamide gels when high sensitivity is required. A simple and rapid protocol for silver staining of proteins following PAGE was developed in the present study. The number of steps was reduced compared to conventional protocol by combining fixing, rinsing, and soaking into a single impregnating step, thus achieving detection of proteins in 20 min. The present method is as sensitive as current protocols with the advantage of saving time and costs.
Quantitative investigation of resolution increase of free‐flow electrophoresis via simple interval sample injection and separation
Authors: Shao Jing , Fan Liu‐Yin , Cao Cheng‐Xi , Huang Xian‐Qing , Xu Yu‐Quan
Published: May 2012

Interval free‐flow zone electrophoresis (FFZE) has been used to suppress sample band broadening greatly hindering the development of free‐flow electrophoresis (FFE). However, there has been still no quantitative study on the resolution increase of interval FFZE. Herein, we tried to make a comparison between bandwidths in interval FFZE and continuous one. A commercial dye with methyl green and crystal violet was well chosen to show the bandwidth. The comparative experiments were conducted under the same sample loading of the model dye (viz. 3.49, 1.75, 1.17, and 0.88 mg/h), the same running time (viz. 5, 10, 15, and 20 min), and the same flux ratio between sample and background buffer (= 10.64 × 10−3). Under the given conditions, the experiments demonstrated that (i) the band broadening was evidently caused by hydrodynamic factor in continuous mode, and (ii) the interval mode could clearly eliminate the hydrodynamic broadening existing in continuous mode, greatly increasing the resolution of dye separation. Finally, the interval FFZE was successfully used for the complete separation of two‐model antibiotics (herein pyoluteorin and phenazine‐1‐carboxylic acid coexisting in fermentation broth of a new strain Pseudomonas aeruginosa M18), demonstrating the feasibility of interval FFZE mode for separation of biomolecules.
Several mechanisms lead to the inactivation of the CDKN2A (P16), P14ARF, or CDKN2B (P15) genes in the GCB and ABC molecular DLBCL subtypes
Authors: Guney Suzan , Jardin Fabrice , Bertrand Philippe , Mareschal Sylvain , Parmentier Françoise , Picquenot Jean‐Michel , Tilly Hervé , Bastard Christian
Published: May 2012

Diffuse large B‐cell lymphoma (DLBCL) represents the most frequent type of aggressive lymphoma. Deletions of the CDKN2A locus, encoding the proteins CDKN2A (P16), P14ARF, and of the CDKN2B locus, encoding the protein CDKN2B (P15), affect one‐third of DLBCL patients. Although other mechanisms that decrease gene expression have been reported, such as promoter methylation, the prognostic value of these mechanisms is still unclear. We studied the deletion and methylation status of these genes in 171 patients and correlated the genomic results with their mRNA expression level and clinical outcome. CDKN2A, P14ARF, and CDKN2B deletions were significantly correlated with decreased mRNA expression (P < 0.0001, P < 0.0001, and P = 0.0148, respectively). P14ARF was methylated in only two patients (1.3%), whereas CDKN2A and CDKN2B were methylated in 36.7 and 31.4% of patients, respectively. Methylation levels greater than 25% were associated with decreased expression of CDKN2A (P = 0.0169). CDKN2A and CDKN2B inactivation by deletion or methylation was observed in 42.7 and 37.4% of cases, respectively. Including P14ARF deletions, we identified an inactivating mechanism for at least one of these genes in 47% of patients. Although gene inactivation was not correlated with the international prognostic index, P14ARF and CDKN2B inactivation was significantly associated with shorter survival (P = 0.0048 and P = 0.0413, respectively), whereas CDKN2A was not (P = 0.085). Low mRNA expression levels of these genes were correlated with the ABC phenotype. Furthermore, our results show that an inactivating methylation was more frequent in the GCB phenotype. © 2012 Wiley Periodicals, Inc.
Different distribution of NOTCH1 mutations in chronic lymphocytic leukemia with isolated trisomy 12 or associated with other chromosomal alterations
Authors: López Cristina , Delgado Julio , Costa Dolors , Conde Laura , Ghita Gabriela , Villamor Neus , Navarro Alba , Cazorla Maite , Gómez Cándida , Arias Amparo , Muñoz Concha , Baumann Tycho , Rozman María , Aymerich Marta , Colomer Dolors , Cobo Francesc , Campo Elías , López‐Guillermo Armando , Montserrat Emili , Carrió Ana
Published: May 2012

Chronic lymphocytic leukemia (CLL) is the most common leukemia among adults in Western countries. Chromosomal abnormalities commonly found using conventional cytogenetics and FISH are del(11)(q22‐23), trisomy 12, del(13)(q14), and del(17)(p13). Trisomy 12 is the most frequent numerical abnormality in CLL. It can appear isolated or associated with other chromosomal aberrations, including t(14;18)(q32;q21) and trisomy 18. The aim of this study was to determine whether CLL patients with isolated trisomy 12 or associated with other chromosomal alterations have different clinico‐pathological features, including a different distribution NOTCH1 mutation. Patients were classified into four groups: Group 1, isolated trisomy 12 (n = 14); Group 2, trisomy 12 plus trisomy 18 (n = 4); Group 3, trisomy 12 plus t(14;18) (n = 8); and Group 4: patients with trisomy 12 plus other abnormalities not involving BCL2 (n = 28). The Binet stage and expression of ZAP70 were significantly different among cytogenetic groups. NOTCH1 mutations were detected in 6/12 (50%) patients from Group 1, 4/25 (16%) patients from Group 4, and in no patient from groups 2 and 3 (P = 0.020). Patients in Group 2 had a more rapid disease progression (median Treatment‐free Survival 2 months) as against patients from Groups 1 (50 months), 3 (69 months), or 4 (68 months; P = 0.001). These findings indicate that the distribution of NOTCH1 mutations in CLL with trisomy 12 is heterogeneous and that the presence of additional chromosomal abnormalities such as trisomy 18 could change the prognosis of these patients. © 2012 Wiley Periodicals, Inc.
CIGARETTE QUITLINES, TAXES, AND OTHER TOBACCO CONTROL POLICIES: A STATE‐LEVEL ANALYSIS
Authors: Brown Henry Shelton , Karson Steve
Published: May 2012

This paper estimates monthly quitline calls using panel data at the state level from January 2005 to June 2010. Calls to state quitline numbers (or 1‐800‐QUITNOW) were measured per million adult smokers in each state. The policies considered include excise taxes, workplace and public smoking bans, and a Peter Jennings television‐based program warning of the health risks of smoking. We found that people anticipating increases in prices begin attempting to quit by calling quitlines. Finally, the Peter Jennings media campaign was highly correlated with quitline calls. Copyright © 2012 John Wiley & Sons, Ltd.
Evaluation of data quality at the Gambia national cancer registry
Authors: Shimakawa Yusuke , Bah Ebrima , Wild Christopher P. , Hall Andrew J.
Published: May 2012

The Gambia National Cancer Registry (GNCR) is one of the few nationwide population‐based cancer registries in sub‐Saharan Africa. Most registries in sub‐Saharan Africa are limited to cities; therefore, the GNCR is important in providing estimates of cancer incidence in rural Africa. Our study assesses the quality of its data. The methods proposed by Bray and Parkin, and Parkin and Bray (Eur J Cancer 2009;45:747–64) were applied to the registry data from 1990 to 2009 to assess comparability, validity and completeness. The system used for classification and coding of neoplasms followed international standards. The percentage of cases morphologically verified was 18.1% for men and 33.1% for women, and that of death certificate only cases was 6.6 and 3.6%, respectively. Incidence rates in rural regions were lower than in the urban part of the country, except amongst young male adults. Comparison with other West African registries showed that the incidences of liver and uterine cervical cancer were comparable, but those of prostate and breast in The Gambia were relatively low. The overall completeness was estimated at 50.3% using the capture–recapture method. The GNCR applies international standard practices to data collection and handling, providing valuable data on cancer incidence in sub‐Saharan Africa. However, the data are incomplete in the rural and elderly populations probably because of health care access and use.
Dexamethasone‐incorporated nanofibrous meshes for antiproliferation of smooth muscle cells: Thermally induced drug‐loading strategy
Authors: Son Young Ju , Yoo Hyuk Sang
Published: May 2012

Pluronic‐immobilized nanofibrous meshes were tailored for thermally induced incorporation of dexamethasone. A diblock copolymer composed of poly(e‐caprolactone)‐poly (ethyleneglycol) (NH2) (PCL‐PEG (NH2)) was electrospun to a nanofibrous mesh, and Pluronic was subsequently surface‐immobilized on the mesh in aqueous phase. Surface‐wettability analysis and 1H NMR spectroscopy confirmed surface‐decoration of nanofibrous meshes with Pluronic moieties depending on the blend ratios of PCL‐PEG(NH2). Fluorescently‐labeled micelles were incorporated in the nanofibrous meshes by temperature modulation and showed attenuated release profiles of the micelles were for 1 month. The suppression degree of drug‐loaded micelle releases was proportional to the blend ratio of PCL‐PEG(NH2). Dexamethasone was formulated into micellar nanoaggregates, and the dexamethasone micelles‐loaded nanofibrous meshes were used for antiproliferation studies of smooth muscle cells. Flow cytometric analysis of the arrested cells at a G0–G1 phase revealed that the dexamethasone micelles‐loaded nanofibrous meshes effectively controlled proliferation of the smooth muscle cells when cells were cultivated with the nanofibrous meshes. The antiproliferation effects of the nanofibrous meshes were closely correlated to the release profiles of the micelles from the nanofibrous meshes with different blend ratios. Thus, dexamethasone‐incorporated nanofibrous meshes can be potentially used for treatments of restenosis after percutaneous transluminal coronary angioplasty. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:2678–2685, 2012.
Sustained delivery of paclitaxel using thermogelling poly(PEG/PPG/PCL urethane)s for enhanced toxicity against cancer cells
Authors: Loh Xian Jun , Yee Benjamin Jia Han , Chia Fu Siong
Published: May 2012

A multiblock poly(ether ester urethane)s comprising poly(ε‐caprolactone), poly(ethylene glycol), and poly(propylene glycol) segments was synthesized. The aqueous copolymer solution exhibited thermogelling behavior at a critical gelation concentration of 3 wt %. The chemical structure and molecular characteristic of the copolymers were studied by gel permeation chromatography, NMR, and fourier transform infrared spectroscopy (FTIR). Rheological characterizations on the thermogel were carried out. Drug release studies using paclitaxel showed that sustained drug release of more than 2 weeks can be achieved with this system. The paclitaxel‐loaded gels showed efficiency in the control of the growth of HeLa cells when compared with the paclitaxel dissolved in solution or paclitaxel encapsulated in Pluronics F127. The results demonstrated that the copolymers could be potentially used in chemotherapeutic applications. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:2686–2694, 2012.
Titania‐polymeric powder coatings with nano‐topography support enhanced human mesenchymal cell responses
Authors: Mozumder Mohammad Sayem , Zhu Jesse , Perinpanayagam Hiran
Published: May 2012

Titanium implant osseointegration is dependent on the cellular response to surface modifications and coatings. Titania‐enriched nanocomposite polymeric resin coatings were prepared through the application of advanced ultrafine powder coating technology. Their surfaces were readily modified to create nano‐rough (<100 nm) surface nano‐topographies that supported human embryonic palatal mesenchymal cell responses. Energy dispersive x‐ray spectroscopy confirmed continuous and homogenous coatings with a similar composition and even distribution of titanium. Scanning electron microscopy (SEM) showed complex micro‐topographies, and atomic force microscopy revealed intricate nanofeatures and surface roughness. Cell counts, mitochondrial enzyme activity reduction of yellow 3‐(4,5‐dimethythiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide (MTT) to dark purple, SEM, and inverted fluorescence microscopy showed a marked increase in cell attachment, spreading, proliferation, and metabolic activity on the nanostructured surfaces. Reverse Transcription‐ Polymerase Chain Reaction (RT‐PCR) analysis showed that type I collagen and Runx2 expression were induced, and Alizarin red staining showed that mineral deposits were abundant in the cell cultures grown on nanosurfaces. This enhancement in human mesenchymal cell attachment, growth, and osteogenesis were attributed to the nanosized surface topographies, roughness, and moderate wetting characteristics of the coatings. Their dimensional similarity to naturally occurring matrix proteins and crystals, coupled with their increased surface area for protein adsorption, may have facilitated the response. Therefore, this application of ultrafine powder coating technology affords highly biocompatible surfaces that can be readily modified to accentuate the cellular response. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:2695–2709, 2012.
A multinational study to develop universal standardization of whole-body bone density and composition using GE Healthcare Lunar and Hologic DXA systems
Authors: Shepherd John A , Fan Bo , Lu Ying , Wu Xiao P , Wacker Wynn K , Ergun David L , Levine Michael A
Published: May 2012

Dual-energy x-ray absorptiometry (DXA) is used to assess bone mineral density (BMD) and body composition, but measurements vary among instruments from different manufacturers. We sought to develop cross-calibration equations for whole-body bone density and composition derived using GE Healthcare Lunar and Hologic DXA systems.

This multinational study recruited 199 adult and pediatric participants from a site in the US (n = 40, ages 6 through 16 years) and one in China (n = 159, ages 5 through 81 years). The mean age of the participants was 44.2 years. Each participant was scanned on both GE Healthcare Lunar and Hologic Discovery or Delphi DXA systems on the same day (US) or within 1 week (China) and all scans were centrally analyzed by a single technologist using GE Healthcare Lunar Encore version 14.0 and Hologic Apex version 3.0. Paired t-tests were used to test the results differences between the systems. Multiple regression and Deming regressions were used to derive the cross-conversion equations between the GE Healthcare Lunar and Hologic whole-body scans.

Bone and soft tissue measures were highly correlated between the GE Healthcare Lunar and Hologic and systems, with r ranging from 0.96 percent fat [PFAT] to 0.98 (BMC). Significant differences were found between the two systems, with average absolute differences for PFAT, BMC, and BMD of 1.4%, 176.8 g and 0.013 g/cm2, respectively. After cross-calibration, no significant differences remained between GE Healthcare Lunar measured results and the results converted from Hologic.

The equations we derived reduce differences between BMD and body composition as determined by GE Healthcare Lunar and Hologic systems and will facilitate combining study results in clinical or epidemiological studies. © 2012 American Society for Bone and Mineral Research.
Skeletal muscle mass is associated with bone geometry and microstructure and serum insulin-like growth factor binding protein-2 levels in adult women and men
Authors: LeBrasseur Nathan K , Achenbach Sara J , Melton L Joseph , Amin Shreyasee , Khosla Sundeep
Published: May 2012

Skeletal muscle and bone form highly-integrated systems that undergo significant age-related changes, but the relationships between muscle mass and trabecular versus cortical bone or trabecular microarchitecture have not been systematically investigated. Thus, we examined the association between appendicular skeletal muscle mass (ASM) relative to height squared (relative ASM) and bone parameters at several sites assessed by conventional as well as high-resolution peripheral QCT in a cohort of 272 women and 317 men aged 20 to 97 years. In women, relative ASM was associated with cortical thickness (CtTh) at the femoral neck, lumbar spine, radius, and tibia (age-and physical activity adjusted r = 0.19–0.32; all p < 0.01). Relative ASM was also associated with trabecular volumetric bone mineral density (vBMD) at the femoral neck and spine (all p < 0.05), and trabecular bone volume to tissue volume (BV/TV), number (TbN), thickness (TbTh), and separation (TbSp) at the radius (all p ≤ 0.05). In all men, relative ASM was associated with CtTh at all sites (age- and physical activity–adjusted r = 0.17–0.28; all p < 0.01). Associations between relative ASM and trabecular vBMD at the spine in men were lost after adjusting for age; however, relative ASM was associated with trabecular vBMD at the femoral neck and TbN and TbSp at the radius (all p < 0.01). We also investigated circulating factors associated with bone health that may be indicative of relative ASM and found that serum insulin-like growth factor (IGF) binding protein-2 (IGFBP-2) levels were the most robust negative predictors of relative ASM in both sexes. Collectively, these data add to the growing body of evidence supporting the highly-integrated nature of skeletal muscle and bone, and provide new insights into potential biomarkers that reflect the health of the musculoskeletal system. © 2012 American Society for Bone and Mineral Research.
Oncologic doses of zoledronic acid induce osteonecrosis of the jaw-like lesions in rice rats (Oryzomys palustris) with periodontitis
Authors: Aguirre J Ignacio , Akhter Mohammed P , Kimmel Donald B , Pingel Jennifer E , Williams Alyssa , Jorgensen Marda , Kesavalu Lakshmyya , Wronski Thomas J
Published: May 2012

Though osteonecrosis of the jaw (ONJ) is temporally-associated with the use of nitrogen-containing bisphosphonates (N-BPs), a cause-and-effect relationship has not yet been established. We hypothesize that ONJ is a two-stage process in which: (1) risk factors initiate pathologic processes in the oral cavity that lead to a supranormal rate of hard tissue necrosis; and (2) powerful antiresorptives reduce the rate of removal of necrotic bone sufficiently to allow its net accumulation in the jaw. To test this hypothesis, we used the rice rat model of periodontitis. At age 28 days, rats (n = 15/group) were placed on a high-sucrose and casein diet to exacerbate the development of periodontitis. Animals were injected subcutaneously (SC) biweekly with vehicle or alendronate (ALN, 15 µg/kg), or IV once monthly with vehicle, a low dose (LD) of zoledronic acid (ZOL), or a high dose (HD) of ZOL and sacrificed after 6, 12, 18, and 24 weeks. Mandibles and maxillae were analyzed to determine the effects on the: (1) progression of periodontitis; (2) integrity of alveolar bone; (3) status of bone resorption and formation; (4) vascularity; and (5) osteocyte viability. We found that only HD-ZOL induced ONJ-like lesions in mandibles of rice rats after 18 and 24 weeks of treatment. These lesions were characterized by areas of exposed necrotic alveolar bone, osteolysis, a honeycomb-like appearance of the alveolar bone, presence of bacterial colonies, and periodontal tissue destruction. In addition, inhibition of bone formation, a paradoxical abolition of the antiresorptive effect of only HD-ZOL, increased osteocyte necrosis/apoptosis, and decreased blood vessel number were found after 18 and/or 24 weeks. Our study suggests that only HD-ZOL exacerbates the inflammatory response and periodontal tissue damage in rice rats, inducing bone lesions that resemble ONJ. © 2012 American Society for Bone and Mineral Research.
Prediction of the properties and thermodynamics of formation for energetic nitrogen‐rich salts composed of triaminoguanidinium cation and 5‐nitroiminotetrazolate‐based anions
Authors: Zhu Weihua , Yan Qingli , Li Jinshan , Cheng Bibo , Shao Yuling , Xia Xuelan , Xiao Heming
Published: May 2012

Density functional theory and volume‐based thermodynamics calculations were performed to study the effects of different substituents and linkages on the densities, heats of formation (HOFs), energetic properties, and thermodynamics of formation for a series of energetic nitrogen‐rich salts composed of triaminoguanidinium cation and 5‐nitroiminotetrazolate anions. The results show that the NO2, NF2, or N3 group is an effective substituent for increasing the densities of the 5‐nitroiminotetrazolate salts, whereas the effects of the bridge groups on the density are coupled with those of the substituents. The substitution of the group NH2, NO2, NF2, N3, or the nitrogen bridge is helpful for increasing the HOFs of the salts. The calculated energetic properties indicate that the NO2, NF2, N3, or NN group is an effective structural unit for improving the detonation performance for salts. The thermodynamics of formation of the salts show that all the salts may be synthesized easily by the proposed reactions. The structure‐property relationships provide basic information for the molecular design of novel high‐energy salts. © 2012 Wiley Periodicals, Inc.