bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal portfolio choice and stochastic volatility
Authors: Gron Anne , Jørgensen Bjørn N. , Polson Nicholas G.
Published: May 2011

In this paper we examine the effect of stochastic volatility on optimal portfolio choice in both partial and general equilibrium settings. In a partial equilibrium setting we derive an analog of the classic Samuelson–Merton optimal portfolio result and define volatility‐adjusted risk aversion as the effective risk aversion of an individual investing in an asset with stochastic volatility. We extend prior research which shows that effective risk aversion is greater with stochastic volatility than without for investors without wealth effects by providing further comparative static results on changes in effective risk aversion due to changes in the distribution of volatility. We demonstrate that effective risk aversion is increasing in the constant absolute risk aversion and the variance of the volatility distribution for investors without wealth effects. We further show that for these investors a first‐order stochastic dominant shift in the volatility distribution does not necessarily increase effective risk aversion, whereas a second‐order stochastic dominant shift in the volatility does increase effective risk aversion. Finally, we examine the effect of stochastic volatility on equilibrium asset prices. We derive an explicit capital asset pricing relationship that illustrates how stochastic volatility alters equilibrium asset prices in a setting with multiple risky assets, where returns have a market factor and asset‐specific random components and multiple investor types. Copyright © 2011 John Wiley & Sons, Ltd.
Nanosized Vanadium, Tungsten and Molybdenum Oxide Clusters Grown in Porous Chitosan Microspheres as Promising Hybrid Materials for Selective Alcohol Oxidation
Authors: El Kadib Abdelkrim , Primo Ana , Molvinger Karine , Bousmina Mosto , Brunel Daniel
Published: May 2011

The ability of chitosan biopolymer to coordinate vanadium, tungsten and molybdenum metallic species and to control their mineralisation growth provides a new family of surface‐reactive organic–inorganic hybrid microspheres. Drying the resulting materials under supercritical conditions allowed the gel network dispersion to be retained, thereby leading to a macroporous catalyst with surface areas ranging from 253 to 278 m2 g−1. On account of the open framework structure of these microspheres, the redox species entangled within the fibrillar network of the polysaccharide aerogels were found to be active, selective and reusable catalysts for cinamylalcohol oxidations.
The Truth about False Unicorn (Chamaelirium luteum): Total Synthesis of 23R,24S‐Chiograsterol B Defines the Structure and Stereochemistry of the Major Saponins from this Medicinal Herb
Authors: Matovic Nicholas J. , Stuthe Julia M. U. , Challinor Victoria L. , Bernhardt Paul V. , Lehmann Reginald P. , Kitching William , De Voss James J.
Published: May 2011

Chamaelirium luteum is used in traditional medicine systems and commercial botanical dietary supplements for the treatment of female reproductive health problems. Despite the wide use of this herb, only very limited phytochemical characterisation is available. Our investigation of C. luteum roots led to the isolation of two new steroidal saponins 1 and 2 that contain an unusual aglycone 3. The absolute configurations of these molecules were unable to be determined spectroscopically and thus the total synthesis of 3 was undertaken and achieved in 16 steps and 1.6 % overall yield from pregnenolone. The key step in the synthesis was the stereoselective installation of the side chain at C‐17 and C‐20, which employed anion‐accelerated oxy‐Cope methodology. The relative configuration of aglycone 3 was determined by X‐ray crystallography of an advanced synthetic intermediate. The absolute configuration was based upon that of the pregnenolone‐derived steroidal skeleton and determined to be 23R,24S.
Flow of viscous fluids over weirs
Authors: Slocum E. W.
Published: May 2011

Flow profiles have been determined experimentally for Newtonian fluids ranging in viscosity from 2,000 to 500,000 cp., flowing over knife‐edged weirs with heights varying from 0.1 to 4.6 in.

It has been demonstrated that within the ranges of the variables studied the condition of a flowing system can be defined by specification of four dimensionless groups,

These groups correspond, respectively, to generalized fluid height, distance upstream, flow rate, and viscosity.

The results have been fitted by an empirical equation with a standard error of ± 10%.
Spouting of mixed particle‐size beds
Authors: Smith J. W. , Reddy K. V. S.
Published: May 2011

A systematic experimental study of the minimum spouting velocity of materials with wide and narrow size ranges, mean particle diameters from 0.0134 to 0.104 inches and solids density from 65.8 to 246.3 lb.m/ft.3has been carried out in a 6‐in. column with four inlet sizes at different bed heights. A new correlation is presented in which the standard deviation of experimental from calculated minimum spouting velocity is 6.87%. Some qualitative conclusions on spoutability, segregation, attrition and electrostatic effects have been presented.
Residence time distribution in multi‐stage systems with recycle
Authors: Haddad A. , Wolf D. , Resnick W.
Published: May 2011

Equations are presented for the residence time distribution in multi‐stage systems in which part of the effluent stream is recycled to the inlet of the system. The cases considered include perfect mixing, piston flow and real systems defined by attenuation and time delay factors. Time delay in the recycle stream is also considered. Graphical solutions for several systems are presented. Recycle of part of the effluent stream results in broadening of the residence time distribution and, in addition, produces a discontinuity in the distribution when a time delay is present.
A Multi‐Element Ion‐Pair Extraction for Trace Metals Determination in Environmental Samples
Authors: Saçmacı Şerife , Kartal Şenol
Published: May 2011

A multi‐element ion‐pair extraction method was described for the preconcentration of Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Ni(II), Pb(II), and Zn(II) ions in environmental samples prior to their determinations by flame atomic absorption spectrometry (FAAS). As an ion‐pair ligand 2‐(4‐methoxybenzoyl)‐N′‐benzylidene‐3‐(4‐methoxyphenyl)‐3‐oxo‐N‐phenyl‐propono hydrazide (MBMP) was used. Some analytical parameters such as pH of sample solution, amount of MBMP, shaking time, sample volume, and type of counter ion were investigated to establish optimum experimental conditions. No interferences due to major components and some metal ions of the samples were observed. The detection limits of the proposed method were found in the range of 0.33–0.9 µg L−1 for the analyte ions. Recoveries were found to be higher than 95% and the relative standard deviation (RSD) was less than 4%. The accuracy of the procedure was estimated by analyzing the two certified reference materials, LGC6019 river water and RTC‐CRM044 soil. The developed method was applied to several matrices such as water, hair, and food samples.
Selective Separation and Preconcentration of Fe(III) and Zn(II) Ions by Solvent Extraction Using a New Triketone Reagent
Authors: Saçmacı Şerife , Kartal Şenol , Saçmacı Mustafa
Published: May 2011

A simple, rapid, and accurate method was developed for separation and preconcentration of trace levels of iron(III) and zinc(II) ions in environmental samples. Methyl‐2‐(4‐methoxy‐benzoyl)‐3‐(4‐methoxyphenyl)‐3‐oxopropanoylcarbamate (MMPC) has been proposed as a new complexing agent for Fe(III) and Zn(II) ions using solvent extraction prior to their determination by flame atomic absorption spectrometry (FAAS). Fe(III) and Zn(II) ions can be selectively separated from Fe(II), Pb(II), Co(II), Cu(II), Mn(II), Cr(III), Ni(II), Cd(II), Ag(I), Au(III), Pd(II), Cr(VI), and Al(III) ions in the solution by using the MMPC reagent. The analytical parameters such as pH, sample volume, shaking time, amount of MMPC reagent, volume of methyl isobutyl ketone (MIBK), effect of ionic strength, and type of back extractant were investigated. The recovery values for Fe(III) and Zn(II) ions were greater than 95% and the detection limits for Fe(III) and Zn(II) ions were 0.26 and 0.32 µg L−1, respectively. The precision of the method as the relative standard deviation changed between 1.8 and 2.1%. Calibration curves have a determination coefficient (r2) of at least 0.997 or higher. The preconcentration factor was found to be 100. Accuracy of the method was checked by analyzing of a certified reference material and spiked samples. The developed method was applied to several matrices such as water, hair, and food samples.
A note on Prandtl boundary layers
Authors: Guo Yan , Nguyen Toan
Published: May 2011

This note concerns nonlinear ill‐posedness of the Prandtl equation and an invalidity of asymptotic boundary layer expansions of incompressible fluid flows near a solid boundary. Our analysis is built upon recent remarkable linear illposedness results established by Gérard‐Varet and Dormy and an analysis by Guo and Tice. We show that the asymptotic boundary layer expansion is not valid for nonmonotonic shear layer flows in Sobolev spaces. We also introduce a notion of weak well‐posedness and prove that the nonlinear Prandtl equation is not well‐posed in this sense near nonstationary and nonmonotonic shear flows. On the other hand, we are able to verify that Oleinik's monotonic solutions are well‐posed. © 2011 Wiley Periodicals, Inc.
eMap and eSlice: a software package for crystallographic computing
Authors: Oleynikov P.
Published: May 2011

eMap is an easy‐to‐use suite of computer programs devoted for crystallographic calculations in X‐ray diffraction and electron crystallography. It is used in several key activities: (1) Kinematical structure factors calculation for electrons and X‐rays. (2) Calculation and visualization of 3D electron density/potential maps and peak search in the generated maps. (3) Visualization of reciprocal space in different modes (X‐rays, selected area electron diffraction, Kikuchi lines and bands, electron diffraction precession, etc.). (4) Simulation of HRTEM images and dynamical electron diffraction patterns by multislice method and convergent beam electron diffraction patterns by Bloch‐wave method. (5) Crystal structure refinement from the electron diffraction patterns taking dynamical effects into account. The user‐friendly graphical user interface facilitates the loading or manual data input, and visualization of intermediate and final results in form of 3D graphics or 2D images, plots, and diagrams. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural and morphological studies on Mn substituted ZnO nanometer‐sized crystals
Authors: Mote V. D. , Purushotham Y. , Dole B. N.
Published: May 2011

Mn substituted ZnO nanocrystals synthesized by a co‐precipitation method. X‐ray diffraction (XRD) studies confirms the presence of wurtzite (hexagonal) crystal structure similar to un doped ZnO, suggesting that doped Mn ions go at the regular Zn sites. The lattice parameters a and c are increasing with increasing Mn content. The unit cell volume increases with increasing Mn concentration, indicating the homogeneous substitution of Mn2+ for the Zn2+. The lattice distortion parameter (εv) is evaluated from XRD data and found that it enhances as Mn content increases. Transmission electron microscopy photographs show that the size of the ZnO crystals is in the range of 20‐50 nm. The SAED pattern confirms the hexagonal and crystalline nature of the samples which are in agreement with X‐ray analysis. The chemical groups of the samples have been identified by FTIR studies (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A critical review of orientation microscopy in SEM and TEM
Authors: Zaefferer S.
Published: May 2011

Orientation microscopy (OM) refers to techniques for reconstruction of microstructures based on the spatially resolved measurement of individual crystallographic phases and orientations. This review gives an overview on different techniques of OM in the scanning and transmission electron mi‐croscope. All rely on the automated evaluation of electron diffraction patterns. The most popular technique is based on electron backscatter diffraction (EBSD) in the SEM. In the TEM several techniques are available which are based on either Kikuchi diffraction patterns, spot diffraction patterns with and without electron precession, or reconstructed spot diffraction patterns. Each technique is introduced in detail. Subsequently the techniques are critically compared with respect to their spatial and angular resolution, their robustness in terms of orientation determination and questions of practical applicability for materials science. One point discussed in detail is the spatial resolution. It is shown that the spatial resolution, i.e. the volume from which the diffraction information is generated, is not very different for the SEM and TEM techniques. For this and other reasons we argue that the EBSD technique is in many cases the best suited method for OM. In those cases where it is not (e.g. investigations on truly nanocrystal‐line materials, beam sensitive samples) it is the spot diffraction method combined with electron precession and template matching for orientation determination which offers the best resolution and robustness. The Kikuchi pattern technique in the TEM is only reasonably used when highest angular resolution is to be achieved, e.g. for lattice constant determination. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Self‐template hydrothermal synthesis ZnS microspheres
Authors: Zhang Yidong , Pan Chuncai , Zhang Yange , He Weiwei
Published: May 2011

Zinc sulfide (ZnS) microspheres were synthesized by a self‐template hydrothermal route using thiourea as sulphur source. The formation of these hollow spheres was mainly attributed to the oriented aggregation of ZnS nanocystals around the gas‐liquid interface between gas (H2S, NH3, or CO2) and water followed by an Ostwald ripening process. The gas bubbles of H2S, NH3, or CO2 produced during the reaction might play a soft‐template to form ZnS hollow microspheres. The products were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), electron diffraction (ED), and photoluminescence (PL). The crystal structure of prepared ZnS microspheres is hexagonal phase polycrystalline. The average microspheres diameter is 1.5 ‐ 6 µm. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Metal Phosphonate Hybrid Mesostructures: Environmentally Friendly Multifunctional Materials for Clean Energy and Other Applications
Authors: Ma Tian‐Yi , Yuan Zhong‐Yong
Published: May 2011

The synthesis of porous hybrid materials has been extended to mesoporous non‐silica‐based organic‐inorganic hybrid materials, in which mesoporous metal phosphonates represent an important family. By using organically bridged polyphosphonic acids as coupling molecules, the homogeneous incorporation of a considerable number of organic functional groups into the metal phosphonate hybrid framework has been realized. Small amounts of organic additives and the pH value of the reaction solution have a large impact on the morphology and textural properties of the resultant hybrid mesoporous metal phosphonate solids. Cationic and nonionic surfactants can be used as templates for the synthesis of ordered mesoporous metal phosphonates. The materials are used as efficient adsorbents for heavy metal ions, CO2, and aldehydes, as well as in the separation of polycyclic aromatic hydrocarbons. They are also useful photocatalysts under UV and simulated solar light irradiation for organic dye degradation. Further functionalization of the synthesized mesoporous hybrids makes them oxidation and acid catalysts, both with impressive performances in the fields of sustainable energy and environment.
Acetylene‐Enhanced Growth of Carbon Nanotubes on Ceramic Microparticles for Multi‐Scale Hybrid Structures
Authors: He Delong , Bai Jinbo
Published: May 2011

A mixture of acetylene and xylene is used as the carbon source to directly synthesize carbon nanotube (CNT)/alumina (Al2O3) microsphere hybrid structures by CVD. The hybrid structures are modulated by varying the acetylene ratio and reactor temperature. The addition of acetylene can significantly improve the CNT growth rate on Al2O3 at temperatures lower than 600 °C. A tenfold improvement in CNT growth rate is obtained at 550 °C when only 2 vol.‐% acetylene is added. Meanwhile, acetylene favors the formation of bundles containing high‐density CNTs. The increase in the temperature promotes the formation of CNTs with large diameters and low number density. Mass spectrometry (MS) is used to investigate the decomposition of a mixture of acetylene/xylene at temperatures ranging from 450 to 700 °C, under the experimental conditions used. Acetylene decomposes with an increasing rate with temperature from 450 °C, however notable decomposition of xylene is not detected below 700 °C, which corresponds to the formation of the CNTs of varied diameters. This study demonstrates the possibility of large‐scale production of desired nano/micrometer multifunctional CNT/Al2O3 hybrid fillers using a gas/liquid mixed carbon source.
The Atomic Layer Deposition of SrB2O4 Films Using the Thermally Stable Precursor Bis(tris(pyrazolyl)borate)strontium
Authors: Saly Mark J. , Munnik Frans , Winter Charles H.
Published: May 2011

The atomic layer deposition (ALD) of strontium borate films is carried out using bis(tris(pyrazolyl)borate)strontium (SrTp2) and water as precursors. Self‐limiting ALD growth is established at 350 °C with SrTp2 and water pulse lengths of ≥ 2.0 s and ≥ 0.3 s, respectively. An ALD window is observed from 300 to 375 °C, in which the growth rate is 0.47 Å per cycle. The thin film compositions are assessed by elastic recoil detection analysis (ERDA) and X‐ray photoelectron spectroscopy (XPS). ERDA suggests compositions of SrB2O4 at growth temperatures of < 350 °C, but the boron/strontium and oxygen/strontium ratios are lower than those of SrB2O4 at 350 and 400 °C. Within the ALD window, hydrogen concentrations range from 0.37(42) to 0.87(7) at.‐%, and the carbon and nitrogen concentrations are below the detection limits. XPS analyses on representative strontium borate thin films show all expected ionizations. X‐ray diffraction (XRD) experiments reveal that the as‐deposited films are amorphous. The surface morphology is assessed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The rms surface roughness of typical 2 µm × 2 µm areas for films deposited at 325 and 350 °C are 0.3 and 0.2 nm, respectively. SEM images of these films show no cracks or pinholes.
A new technique for spectrophotometric determination of Pseudoephedrine and Guaifenesin in syrup and synthetic mixture
Authors: Riahi Siavash , Hadiloo Farshad , Milani Seyed Mohammad R. , Davarkhah Nazila , Ganjali Mohammad R. , Norouzi Parviz , Seyfi Payam
Published: May 2011

The accuracy in predicting different chemometric methods was compared when applied on ordinary UV spectra and first order derivative spectra. Principal component regression (PCR) and partial least squares with one dependent variable (PLS1) and two dependent variables (PLS2) were applied on spectral data of pharmaceutical formula containing Pseudoephedrine (PDP) and Guaifenesin (GFN). The ability to derivitize in resolved overlapping spectra chloropheniramine maleate was evaluated when multivariate methods are adopted for analysis of two component mixtures without using any chemical pretreatment. The chemometrics models were tested on an external validation dataset and finally applied to the analysis of pharmaceuticals. Significant advantages were found in analysis of the real samples when the calibration models from derivative spectra were used. It should also be mentioned that the proposed method is a simple and rapid way requiring no preliminary separation steps and can be used easily for the analysis of these compounds, especially in quality control laboratories. Copyright © 2011 John Wiley & Sons, Ltd.
Tgfβ/Alk5 signaling is required for shear stress induced klf2 expression in embryonic endothelial cells
Authors: Egorova Anastasia D. , Van der Heiden Kim , Van de Pas Simone , Vennemann Peter , Poelma Christian , DeRuiter Marco C. , Goumans Marie‐José T. H. , Gittenberger‐de Groot Adriana C. , ten Dijke Peter , Poelmann Robert E. , Hierck Beerend P.
Published: May 2011

Endothelial cells (EC) translate biomechanical forces into functional and phenotypic responses that play important roles in cardiac development. Specifically, EC in areas of high shear stress, i.e., in the cardiac outflow tract and atrioventricular canal, are characterized by high expression of Krüppel‐like factor 2 (Klf2) and by transforming growth factor‐beta (Tgfβ)‐driven endothelial‐to‐mesenchymal transition. Extraembryonic venous obstruction (venous clip model) results in congenital heart malformations, and venous clip‐induced alterations in shear stress‐related gene expression are suggestive for an increase in cardiac shear stress. Here, we study the effects of shear stress on Klf2 expression and Tgfβ‐associated signaling in embryonic EC in vivo using the venous clip model and in vitro by subjecting cultured EC to fluid flow. Cellular responses were assessed by analysis of Klf2, Tgfβ ligands, and their downstream signaling targets. Results show that, in embryonic EC, shear stress activates Tgfβ/Alk5 signaling and that induction of Klf2 is an Alk5 dependent process. Developmental Dynamics 240:1670–1680, 2011. © 2011 Wiley‐Liss, Inc.
Asymmetric Synthesis of New β‐Lactam Lipopeptides as Bacterial Signal Peptidase I Inhibitors
Authors: Crauste Céline , Froeyen Matheus , Anné Jozef , Herdewijn Piet
Published: May 2011

The transmembrane bacterial enzyme, signal peptidase I, is recognized as being a promising target for reducing the emergence of drug resistance. The asymmetric synthesis and the biological evaluation of original β‐lactam lipopeptides have been performed to discover potent signal peptidase inhibitors. The importance of the azetidinone motif of these lipopeptides has been demonstrated and can serve as a starting point to exploit and improve the reactivity of the β‐lactam in peptidomimetics.
Minimally invasive endoscopic‐assisted resection of benign tumors in the accessory parotid gland: 5 case studies
Authors: Xie Lei , Zhang Deguang , Lu M. M. Xiaoxiao , Gao B. M. Li
Published: May 2011

Background

A modified Blair's incision or standard facelift incision is recommended to remove tumors in the accessory parotid gland. These incisions frequently result in long and visible scars. Therefore, the authors have introduced an endoscopic approach via a small preauricular incision to achieve excision of benign tumors in the accessory parotid gland.

Methods

The endoscopic surgical technique was performed on 5 patients with benign tumors in the accessory parotid gland.

Results

Endoscopic‐assisted resection of the benign tumors in the accessory parotid gland was feasible in all 5 patients. This procedure lasted 105 minutes on average. Facial paralysis, salivary fistula, and ear‐lobular numbness were not found postoperatively. The follow‐up period was 1 year, during which no Frey's syndrome and recurrence were found. All preauricular scars were aesthetically satisfactory.

Conclusions

The minimally invasive endoscopic approach via a small preauricular incision is an optional method of the accessory parotid gland benign tumor resection. © 2011 Wiley Periodicals, Inc. Head Neck, 2012
Early tongue carcinoma: Analysis of failure
Authors: Preis Michal , Hadar Tuvia , Soudry Ethan , Shpitzer Thomas , Strenov Yulia , Hod Roy , Nageris Ben I. , Feinmesser Raphael
Published: May 2011

Background

Failure rate of surgery for early tongue carcinoma remains high. We sought to identify patterns of failure and recurrence risk factors.

Methods

Data review was carried out on 50 patients treated for early tongue carcinoma (T1/2N0M0); surgery was unsuccessful in 11 of these patients. All patients underwent transoral resection of the tongue tumor and prophylactic neck dissection (supraomohyoid).

Results

Tumor recurred within 3 to 18 months. Nine died of disease. Four had failure in neck level 4, 6 in level 1, and 1 simultaneously in level 1 and locally. Most tumors were moderately differentiated. Average depth was 6.64 mm.

Conclusions

We report 11 patients with early tongue carcinoma who failed local excision with neck dissection. Failures occurred in level 4 (4 patients) and level 1 (7 patients). This group may benefit from extended neck surgery. Sex, age, stage, and depth of tumor were not significantly different in the group with treatment failure. Tumors in the group with treatment failure were more poorly differentiated. © 2011 Wiley Periodicals, Inc. Head Neck, 2012
Synthesis, self‐assembly, and cytotoxicity of well‐defined trimethylated chitosan‐O‐poly(ε‐caprolactone): Effect of chitosan molecular weight
Authors: Zhang Haiwen , Cai Guoqiang , Tang Guping , Wang Liqun , Jiang Hongliang
Published: May 2011

Structurally well‐defined trimethylated chitosan‐O‐poly(ε‐caprolactone) (TMC‐O‐PCL) was synthesized under mild homogeneous conditions, using sodium dodecyl sulfate‐dimethylated chitosan complex (SDC) as an organosoluble intermediate. The effect of chitosan molecular weight (MW) on the preparation, organosolubility, self‐assembly, and cytotoxicity of the copolymers was investigated. The copolymers with low‐MW chitosan backbone had improved solubility in common organic solvents. Spherical micelles with average diameter of 25–55 nm and uniform morphology were formed through self‐assembly of TMC‐O‐PCL in pH 7.4 PBS. When trimethylation degree of the copolymers was above 44%, the micelles could remain stable in neutral aqueous media. The critical aggregation concentration of TMC‐O‐PCL slightly increased with a decrease in the MW of chitosan backbone. The cytotoxicity of the cationic micelles could be suppressed by increasing PCL grafting levels, reducing trimethylation degree, and MW of the chitosan backbone. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Effects of N‐acetylcysteine on TEGDMA‐ and HEMA‐induced suppression of osteogenic differentiation of human osteosarcoma MG63 cells
Authors: Kim Na Ryoung , Lim Bum‐Soon , Park Hee Chul , Son Kyung Mi , Yang Hyeong‐Cheol
Published: May 2011

Triethyleneglycol dimethacrylate (TEGDMA) and 2‐hydroxyethyl methacrylate (HEMA) are major resinous components of dental restorative materials and dentin bonding adhesives. Resin monomers are known to cause cytotoxicity in mammalian cells via oxidative stress and inhibit differentiation of dental pulp cells and osteoblasts. This study was aimed to investigate whether oxidative stress was involved in the inhibition of TEGDMA‐ and HEMA‐induced differentiation. TEGDMA and HEMA reduced alkaline phosphatase (ALP) activity and the mRNA expression of the osteopontin (OPN) gene in MG63 cells at noncytotoxic concentrations. On the other hand, N‐acetylcysteine (NAC) did not affect ALP activity at concentrations below 10 mM. Reduced ALP activity and OPN mRNA expression by TEGDMA were partially recovered via cotreatment with NAC. However, NAC did not exhibit significant effects in HEMA‐treated cells. Glutathione (GSH) levels were also down‐regulated by both TEGDMA and HEMA. The addition of NAC induced the partial recovery of GSH in cells treated with 0.5 mM TEGDMA. On the other hand, the levels of GSH in HEMA‐treated cells were not affected by NAC. These results suggest that oxidative stress is involved in the suppression of differentiation by TEGDMA. Translocation of Nrf2 from the cytoplasm to the nucleus has been known to play a role in the suppression of osteogenic differentiation by oxidative stress. However, Nrf2 did not move into the nucleus in resin monomer‐treated MG63 cells, suggesting the contribution of other signaling pathways to the suppressive effects of resin monomers. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Suppressor of cytokine signaling 4 (SOCS4): Moderator of ovarian primordial follicle activation
Authors: Sutherland J.M. , Keightley R.A. , Nixon B. , Roman S.D. , Robker R.L. , Russell D.L. , McLaughlin E.A.
Published: May 2011

Mammalian ovarian primordial follicle activation and regulation is considered as one of the most important stages of folliculogenesis and as such requires exquisite control. Selection of quiescent follicles to enter the growing pool determines the rate of supply of maturing follicles over the female reproductive lifespan. To coordinate this process a range of positive and negative input signals contribute to determine follicle fate. This study demonstrates that the cytokine Leukemia Inhibitory Factor (LIF) activates the Janus Kinase 1/Signal Transducers and Activators of Transcription 3 (JAK1/STAT3) signaling pathway in pre‐granulosa cells and positively regulates primordial follicle activation. Negative regulation of the JAK/STAT pathway is controlled by the suppressor of cytokine signaling 4 (SOCS4) protein, which target members of negative feedback loops, Cardiotrophin like Cytokine (CLC), Poly (rC) Binding Protein 1 (PCBP1), and Cytosolic Malate Dehydrogenase (MDH1) to suppress follicle growth and development. J. Cell. Physiol. 227: 1188–1198, 2012. © 2011 Wiley Periodicals, Inc.
Transcriptomic profiling of astrocytes treated with the Rho kinase inhibitor Fasudil reveals cytoskeletal and pro‐survival responses
Authors: Lau Chew L. , Perreau Victoria M. , Chen Minghui J. , Cate Holly S. , Merlo Daniel , Cheung Nam S. , O'Shea Ross D. , Beart Philip M.
Published: May 2011

Inhibitors of Rho kinase (ROCK) have potential for management of neurological disorders by inhibition of glial scarring. Since astrocytes play key roles in brain physiology and pathology, we determined changes in the astrocytic transcriptome produced by the ROCK inhibitor Fasudil to obtain mechanistic insights into its beneficial action during brain injury. Cultured murine astrocytes were treated with Fasudil (100 µM) and morphological analyses revealed rapid stellation by 1 h and time‐dependent (2–24 h) dissipation of F‐actin‐labelled stress fibres. Microarray analyses were performed on RNA and the time‐course of global gene profiling (2, 6, 12 and 24 h) provided a comprehensive description of transcriptomic changes. Hierarchical clustering of differentially expressed genes and analysis for over‐represented gene ontology groups using the DAVID database focused attention on Fasudil‐induced changes to major biological processes regulating cellular shape and motility (actin cytoskeleton, axon guidance, transforming growth factor‐β (TGFβ) signalling and tight junctions). Bioinformatic analyses of transcriptomic changes revealed how these biological processes contributed to changes in astrocytic motility and cytoskeletal reorganisation. Here genes associated with extracellular matrix were also involved, but unexpected was a subset of alterations (EAAT2, BDNF, anti‐oxidant species, metabolic and signalling genes) indicative of adoption by astrocytes of a pro‐survival phenotype. Expression profiles of key changes with Fasudil and another ROCK inhibitor Y27632 were validated by real‐time PCR. Although effects of ROCK inhibition have been considered to be primarily cytoskeletal via reduction of glial scarring, we demonstrate additional advantageous actions likely to contribute to their ameliorative actions in brain injury. J. Cell. Physiol. 227: 1199–1211, 2012. © 2011 Wiley Periodicals, Inc.
Age‐related differences in cellular and molecular profiles of inflammatory responses after spinal cord injury
Authors: Kumamaru Hiromi , Saiwai Hirokazu , Ohkawa Yasuyuki , Yamada Hisakata , Iwamoto Yukihide , Okada Seiji
Published: May 2011

Previous experimental and clinical studies have suggested that the behavioral and pathological outcomes of spinal cord injury (SCI) are affected by the individual's age at the time of injury. However, the underlying mechanism responsible for these differences remains elusive because it is difficult to match injuries of similar severities between young and adult animals due to differences in the sizes of their respective spinal cords. In this study, the spinal cord size‐matched young (4‐week‐old) and adult (10‐week‐old) mice were compared to evaluate their locomotor functions and inflammatory cellular/molecular responses after standardized contusion SCI. During the acute phase of SCI, young mice showed better functional recovery and lower pro‐inflammatory cytokines/chemokines compared to adult mice. Flow‐cytometric analysis revealed that the time courses of leukocyte infiltration were comparable between both groups, while the number of infiltrating neutrophils significantly decreased from 6 h after SCI in young mice. By combining flow‐cytometric isolation and gene expression analysis of each inflammatory cell fraction, we found that microglial cells immediately initiate the production of several cytokines in response to SCI, which serve as major sources of IL‐6, TNFa, and CXCL1 in injured spinal cord. Interestingly, the secretion of pro‐inflammatory cytokines/chemokines but not anti‐inflammatory cytokines by microglia was significantly lower in young mice compared to that in adult mice at 3 h after SCI, which will be attributed to the attenuation of the subsequent neutrophil infiltration. These results highlight age‐related differences in pro‐inflammatory properties of microglial cells that contribute to the amplification of detrimental inflammatory responses after SCI. J. Cell. Physiol. 227: 1335–1346, 2012. © 2011 Wiley Periodicals, Inc.
Bradykinin‐mediated cell proliferation depends on transactivation of EGF receptor in corneal fibroblasts
Authors: Cheng Ching‐Yi , Tseng Hui‐Ching , Yang Chuen‐Mao
Published: May 2011

In previous studies, bradykinin (BK) has been shown to induce cell proliferation through BK B2 receptor (B2R) via p42/p44 MAPK in Statens Seruminstitut Rabbit Corneal Cells (SIRCs). In addition to this pathway, EGFR transactivation pathway has been implicated in linking a variety of G‐protein coupled receptors to MAPK cascades. Here, we further investigate whether these transactivation mechanisms participating in BK‐induced cell proliferation in SIRCs. Using an immunofluorescence staining and RT‐PCR, we initially characterize that SIRCs were corneal fibroblasts and predominantly expressed B2R by BK. Inhibition of p42/p44 MAPK by the inhibitors of Src, EGFR, and Akt or transfection with respective siRNAs prevents BK‐induced DNA synthesis in SIRCs. The mechanisms underlying these responses were mediated through phosphorylation of Src and EGFR via the formation of Src/EGFR complex which was attenuated by PP1 and AG1478. Moreover, BK‐induced p42/p44 MAPK and Akt activation was mediated through EGFR transactivation, which was diminished by the inhibitors of MMP‐2/9 and heparin‐binding EGF‐like factor (HB‐EGF). Finally, increased nuclear translocation of Akt and p42/p44 MAPK turns on early gene expression leading to cell proliferation. These results suggest that BK‐induced cell proliferation is mediated through c‐Src‐dependent transactivation of EGFR via MMP2/9‐dependent pro‐HB‐EGF shedding linking to activation of Akt and p42/p44 MAPK in corneal fibroblasts. J. Cell. Physiol. 227: 1367–1381, 2012. © 2011 Wiley Periodicals, Inc.
Fluorescence derivatization of single‐walled carbon nanotubes for analysis by means of conventional CE‐LIF
Authors: Yamamoto Tatsuhiro , Murayama Shuhei , Kato Masaru
Published: May 2011

Single‐walled carbon nanotubes (SWNTs) are now widely used in many fields, and while many analytical methods for SWNTs have been reported, there are few practical analytical methods that combine the necessary levels of selectivity and sensitivity. We have developed a highly sensitive separation method for fluorescence‐derivatized SWNTs by means of conventional CE with laser‐induced fluorescence. First, SWNTs were dispersed using a triphenylene derivative into the water, and the excess dispersant was removed by nitric acid treatment. The dispersed SWNTs were then derivatized with a fluorescence reagent, 4‐aminofluorescein. Finally, the derivatized SWNTs were analyzed using a conventional apparatus CE‐LIF detection. The SWNTs migrated within 20 min. The detection sensitivity of SWNTs was improved by about 170 times with LIF detection as compared with UV detection. We anticipate that the derivatized SWNTs can also be detected with high sensitivity using LC.
VARIATIONS IN ECOSYSTEM SERVICE VALUES AND LOCAL ECONOMY IN RESPONSE TO LAND USE: A CASE STUDY OF WU'AN, CHINA
Authors: Zhang J. J. , Fu M. C. , Zeng H. , Geng Y. H. , Hassani F. P.
Published: May 2011

In an industrial/mining city, land use, ecosystem service values (ESVs) and local economy have a close relation. The study reported in this paper is conducive to optimising land use and to balancing ecosystem services and local economy. The aim is to provide useful information and advice for industrial/mining cities concerned with sustainable development. Wu'an, which is rich in mineral resources and an important energy supplier in Hebei Province, is selected as the study area. The ecosystem service value coefficients of industrial ecosystem and urban ecosystem are estimated adopting the cost method and applied to the city from 1996 to 2005. The temporal and spatial changes of the ESVs estimated within the entire ecosystem, sub‐ecosystems and individual ecosystem services are analysed and discussed based on land use. The results show that land use in Wu'an had a great influence on the ESVs and especially the project of converting farmland into forests determined the entire ecosystem structure and functions. Additionally, the study shows the comparing relationships between ecosystem service values and local economy through various mathematical expressions. One significant relationship can be abstracted into an inverse curve (zone) under restrained conditions. The conclusions suggest that the rapid local economy development should build on a reasonable land use with emphasis on the high ecosystem services. Copyright © 2011 John Wiley & Sons, Ltd.
Ambivalence in living liver donors
Authors: Simpson Mary Ann , Kendrick Julia , Verbesey Jennifer E. , Morin Denise S. , Dew Mary Amanda , Trabucco Agnes , Pomposelli James J. , Pomfret Elizabeth A.
Published: May 2011

All right hepatic lobe (RHL) donors in our program are asked to participate in a longitudinal quality-of-life study that begins at their evaluation and continues throughout the first postdonation year. Here we report the characteristics of donor candidates who completed the donation process despite ambivalence. In all, 183 RHL candidates consented, and 133 became donors. Ambivalent donors (ADs; n = 45) identified themselves through verbal statements or written comments, or they were identified by staff during the evaluation. ADs were predominantly male (73.3%), were older than unambivalent donors (UADs; >35 years: 76% of ADs versus 53% of UADs, P = 0.008), and were well educated (college graduate: 60% of ADs versus 17% of UADs, P = 0.01). Brother-to-brother and son-to-father combinations were most common among ADs. Alcohol (22% versus 11%, P = 0.04) and hepatitis C virus (51% versus 27%, P = 0.008) were more common as disease etiologies for recipients with ADs versus recipients with UADs. More ADs than UADs considered themselves to be religious (68.9% versus 43.2%, P = 0.007). Ambivalence about RHL donation was present in 33.8% of the candidates who completed the donation process. These results suggest that ambivalence should not be the sole reason for disqualifying a potential donor who otherwise satisfies program requirements. Liver Transpl 17:1226–1233, 2011. © 2011 AASLD.
From Polyesters to Polyamides Via ON Acyl Migration: An Original Multi‐Transfer Reaction
Authors: Tailhades Julien , Blanquer Sébastien , Nottelet Benjamin , Coudane Jean , Subra Gilles , Verdié Pascal , Schacht Etienne , Martinez Jean , Amblard Muriel
Published: May 2011

A new strategy for the synthesis of polyamides from polyesters of hydroxyl‐containing amino acids using a multi ON acyl transfer reaction was developed. This original approach allowed the synthesis of three generations of polymers from the same starting monomer. The polymerization of N‐benzyloxycarbonyl‐serine and its γ‐homologated derivative provided the Z‐protected polyesters; then the water‐soluble polycationic polyesters were obtained by removal of the Z‐protecting group; and finally the polyamides were obtained by a base‐induced multi ON acyl transfer, both in aqueous or organic medium. The key step transfer reaction was monitored by the disappearance and appearance of characteristic NMR proton signals and IR bands of polyesters and polyamides.

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Botulinum toxin modulates basal ganglia but not deficient somatosensory activation in orofacial dystonia
Authors: Dresel Christian , Bayer Ferdinand , Castrop Florian , Rimpau Christoph , Zimmer Claus , Haslinger Bernhard
Published: May 2011

The etiology of idiopathic orofacial dystonia is incompletely understood. Neurophysiological studies indicated that a sensory dysfunction could play a key role in the pathophysiology of focal dystonia. To explore if central sensory processing is abnormal in patients with blepharospasm and Meige's syndrome and to study the effects of botulinum toxin (BTX) treatment, we systematically mapped the somatotopic representations of punctate tactile stimuli in these patients before and after therapy.

Methods:

Standardized tactile stimuli were pseudorandomly applied to the forehead, upper lip, and hand by a MR‐compatible stimulation device during event‐related fMRI.

Results:

Patients showed a deficient activation in primary and secondary somatosensory representations of affected and unaffected (right hand) body regions compared to healthy controls. Although clinically effective BTX treatment did not modulate this impaired cortical activation, it reduced the activation of the thalamus and contralateral putamen during forehead stimulation.

Conclusions:

This study reveals a more generalized dysfunction of the somatosensory cortex including asymptomatic body representations in orofacial dystonia. Deficient cortical sensory activation may be due to a dedifferentiation of somatosensory representations and could represent a critical functional change within the basal ganglia‐thalamocortical loops facilitating dystonic movements. Modulation of basal ganglia activation might reflect an indirect remote effect of BTX treatment on these sensorimotor circuits. © 2010 Movement Disorder Society
Simultaneous T2 and lipid quantitation using IDEAL‐CPMG
Authors: Janiczek Robert L. , Gambarota Giulio , Sinclair Christopher D. J. , Yousry Tarek A. , Thornton John S. , Golay Xavier , Newbould Rexford D.
Published: May 2011

Muscle damage, edema, and fat infiltration are hallmarks of a range of neuromuscular diseases. The T2 of water, T2,w, in muscle lengthens with both myocellular damage and inflammation and is typically measured using multiple spin‐echo or Carr–Purcell–Meiboom–Gill acquisitions. However, microscopic fat infiltration in neuromuscular diseases prevents accurate T2,w quantitation as the longer T2 of fat, T2,f, masks underlying changes in the water component. Fat saturation can be inconsistent across the imaging volume and removes valuable physiological fat information. A new method is presented that combines iterative decomposition of water and fat with echo asymmetry and least squares estimation with a Carr–Purcell–Meiboom–Gill–sequence. The sequence results in water and fat separated images at each echo time for use in T2,w and T2,f quantification. With knowledge of the T2,w and T2,f, a T2‐corrected fat fraction map can also be calculated. Monte‐Carlo simulations and measurements in phantoms, volunteers, and a patient with inclusion body myositis are demonstrated. In healthy volunteers, uniform T2,w and T2‐corrected fat fraction maps are present within all muscle groups. However, muscle‐specific patterns of fat infiltration and edema are evident in inclusion body myositis, which demonstrates the power of separating and quantifying the fat and water components. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
Reducing peripheral nerve stimulation due to gradient switching using an additional uniform field coil
Authors: Hidalgo‐Tobon Silvia S. , Bencsik Martin , Bowtell Richard
Published: May 2011

This study shows that larger rates of change of gradient with time (dG/dt) can be achieved at the threshold for peripheral nerve stimulation by applying a uniform concomitant field varying synchronously with a transverse field gradient and that this increase may be achieved without significant reduction of the spatial extent of the region over which imaging can be carried out. Realization of similar benefits through application of a uniform, z‐directed field varying synchronously with an axial gradient is also demonstrated. The design and construction of transverse and axial coil arrangements is described, along with the results of volunteer studies that were carried out on 20 subjects, with the subjects positioned with four different regions (head, heart, hips, and knees) centered in the coils. These experiments were carried out at zero‐field on a prototype system in which the coils were not actively shielded. The uniform concomitant field coil was not torque balanced. The increase in the rate of change of gradient at the threshold for peripheral nerve stimulation that could be achieved by the addition of the uniform field depends on body position and was larger for the transverse coils (head = × 1.9 ± 0.6; heart = × 0.9 ± 0.3; hips = × 1.4 ± 0.4; knees = × 1.5 ± 0.4) than for the axial coils (head = × 1.5 ± 0.6; heart = × 0.8 ± 0.3; hips = × 1.3 ± 0.4; knees = × 1.1 ± 0.3). Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
In vivo molecular MRI of cell survival and teratoma formation following embryonic stem cell transplantation into the injured murine myocardium
Authors: Chung Jaehoon , Kee Kehkooi , Barral Joëlle K. , Dash Rajesh , Kosuge Hisanori , Wang Xi , Weissman Irving , Robbins Robert C. , Nishimura Dwight , Quertermous Thomas , Reijo‐Pera Renee A. , Yang Phillip C.
Published: May 2011

Embryonic stem cells (ESCs) have shown the potential to restore cardiac function after myocardial injury. Superparamagnetic iron oxide nanoparticles (SPIO) have been widely employed to label ESCs for cellular MRI. However, nonspecific intracellular accumulation of SPIO limits long‐term in vivo assessment of the transplanted cells. To overcome this limitation, a novel reporter gene (RG) has been developed to express antigens on the ESC surface. By employing SPIO‐conjugated monoclonal antibody against these antigens (SPIO‐MAb), the viability of transplanted ESCs can be detected in vivo. This study aims to develop a new molecular MRI method to assess in vivo ESC viability, proliferation, and teratoma formation. The RG is designed to express 2 antigens (hemagglutinin A and myc) and luciferase on the ESC surface. The two antigens serve as the molecular targets for SPIO‐MAb. The human and mouse ESCs were transduced with the RG (ESC‐RGs) and transplanted into the peri‐infarct area using the murine myocardial injury model. In vivo MRI was performed following serial intravenous administration of SPIO‐MAb. Significant hypointense signal was generated from the viable and proliferating ESCs and subsequent teratoma. This novel molecular MRI technique enabled in vivo detection of early ESC‐derived teratoma formation in the injured murine myocardium. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.