bluuebunny/crossref_metadata_2025 huggingface dataset:
Trace bensulfuron‐methyl analysis in tap water, soil, and soybean samples by a combination of molecularly imprinted stir bar sorption extraction and HPLC‐UV
Authors: Chen Changbao , Yang Lieqing , Zhou Jie
Published: May 2011

A molecularly imprinted stir bar was prepared using bensulfuron‐methyl as the template molecule and methacrylic acid as the functional monomer. The imprinted and nonimprinted stir bars were characterized by scanning electron microscopy, nitrogen sorption porosimetry, thermogravimetric analysis, and differential scanning calorimetry. Extraction time, desorption time and pH value affecting extraction efficiency of the stir bar have been evaluated to achieve the selectively direct preconcentration of the template from aqueous samples. Competitive sorption experiments demonstrated that the imprinted stir bar gave high selectivity and imprinted effect on the template bensulfuron‐methyl compared to the nonimprinted stir bar. Based on S/N of 3, LOD was 0.83 nM. The method showed good recoveries and precision, 92.4% (RSD 1.5%, n = 3) for tap water spiked with 126 ng (100 mL sample), 84.6% (RSD 2.2%, n = 3) for soil spiked with 210 ng (100 g sample) and 73.7% (RSD 2.1%, n = 3) for soybean spiked with 250 ng (5 g sample), suggesting that the imprinted stir bar sorption extraction can be successfully applied to the preconcentration of bensulfuron‐methyl in real samples. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Processing‐improved properties and morphology of PP/COC blends
Authors: Vacková Tat'ana , Šlouf Miroslav , Nevoralová Martina , Kaprálková Ludmila
Published: May 2011

The aim of this study was to improve mechanical properties of polypropylene/cycloolefin copolymer (PP/COC) blends by processing‐induced formation of long COC fibers. According to the available literature, the fibrous morphology in PP/COC blends was observed just once by coincidence. For this reason, we focused our attention on finding processing conditions yielding PP/COC fibrous morphology in a well‐defined, reproducible way. A number of PP/COC blends were prepared by both compression molding and injection molding (IM). Neat polymers were characterized by rheological measurements, whereas phase morphology of the resulting PP/COC blends was characterized by means of scanning electron microscopy (SEM). The longest COC fibers were achieved in the injection molded PP/COC blends with compositions 75/25 and 70/30 wt %. Elastic modulus and yield strength of all blends were measured as functions of the blend composition using an Instron tensile tester; statistically significant improvement of the yield strength due to fibrous morphology was proved. Moreover, two different models were applied in the analysis of mechanical properties: (i) the equivalent box model for isotropic blends and (ii) the Halpin‐Tsai model for long fiber composites. In all PP/COC blends prepared by IM, the COC fibers were oriented in the processing direction, as documented by SEM micrographs, and acted as a reinforcing component, as evidenced by stress–strain measurements. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis and swelling properties of crosslinked poly(orthosilicate)s from cyclohexanedimethanols
Authors: Sonmez Hayal Bulbul , Karadag Koksal , Onaran Gulsah
Published: May 2011

Condensations of cyclohexanedimethanol derivatives with tetraethyl orthosilicate in the proper stoichiometric ratio produce crosslinked poly(orthosilicate)s. Synthesized crosslinked polymers have swelling abilities in common organic solvents such as tetrahydrofuran (THF), dichloromethane, benzene and acetone. All these polymers are moderately thermally stable and possess solvent uptake abilities that are not only good and fast but are also regenerable. FTIR, solid‐state 13C, 29Si‐NMR and thermal methods were used to characterize these synthesized polymers. The effects of different cyclohexanedimethanol derivatives on the properties of polymers were also examined. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122:1182–1189, 2011
Microporous carbon membranes from sulfonated poly(phthalazinone ether sulfone ketone): Preparation, characterization, and gas permeation
Authors: Zhang Bing , Wu Yonghong , Wang Tonghua , Qiu Jieshan , Zhang Shouhai
Published: May 2011

Microporous carbon membranes (MCM) were prepared from sulfonated poly(phthalazinone ether sulfone ketone) (SPPESK) through stabilization and pyrolysis processes. The effects of sulfonation degree (SD) of SPPESK and the stabilization temperature on the structure and gas permeation of MCM were investigated. The thermal decomposition behavior of SPPESK was studied by thermogravimetric analysis‐mass spectrometry. The evolution of functional groups on membrane surface was detected by Fourier transform infrared spectroscopy during heat treatment. The resultant MCM was characterized by X‐ray diffraction, Raman spectroscopy, nitrogen adsorption technique and pure gas permeation test (including the gases of H2, CO2, O2, and N2), respectively. The results have shown that the removal of sulfonic acid groups in SPPESK leads to a weight loss stage in the temperature range of 250–450°C. The surface area, maximum pore volume, and gas permeability of MCM increase with the SD increasing from 59 to 75%, together with the reduction of selectivity. Similarly, the gas permeability of MCM also increases with elevating the stabilization temperature from 350 to 400°C at the loss of selectivity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Cytotoxic Property of Surfactant–Cobalt(III) Complexes on a Human Breast Cancer Cell Line
Authors: Kumar Rajendran Senthil , Riyasdeen Anvarbatcha , Dinesh Mohanakrishnan , Paul Christo Preethy , Srinag Suresh , Krishnamurthy Hanumanthappa , Arunachalam Sankaralingam , Akbarsha Mohammad Abdulkadher
Published: May 2011

The cancer chemotherapeutic potential of surfactant–cobalt(III) complexes, cis‐[Co(bpy)2(C14H29NH2)Cl](ClO4)2 · 3 H2O (1) and cis‐[Co(phen)2(C14H29NH2)Cl](ClO4)2 · 3 H2O (2) (bpy = 2,2′‐bipyridine, phen = 1,10‐phenanthroline) on MCF‐7 breast cancer cell was determined adopting MTT assay and specific staining techniques. The complexes affected the viability of the cells significantly and the cells succumbed to apoptosis as seen in the changes in the nuclear morphology and cytoplasmic features. Since the complex 2 appeared to be more potent, further assays were carried out on the complex 2. Single‐cell electrophoresis indicated DNA damage. The translocation of phosphatidyl serine and loss of mitochondrial potential was revealed by annexin V‐Cy3 staining and JC‐1 staining respectively. Western blot analysis revealed up‐regulation of pro‐apoptotic p53 and down‐regulation of anti‐apoptotic Bcl‐2 protein. Taken together, the surfactant–cobalt(III) complex 2 would be a potential candidate for further investigation for application as a chemotherapeutic for cancers in general and estrogen receptor‐positive breast cancer in particular.
Synthesis and Pharmacological Evaluation of a Potent and Selective σ1 Receptor Antagonist with High Antiallodynic Activity
Authors: Utech Tina , Köhler Jens , Buschmann Helmut , Holenz Jörg , Vela Jose Miguel , Wünsch Bernhard
Published: May 2011

Based on the pharmacophore model of Glennon the conformationally restricted σ1 receptor ligand 2 with a 1,3‐dioxane moiety has been designed and synthesized. The three step synthesis (transacetalization with pentane‐1,3,5‐triol, tosylation, and nucleophilic substitution with benzylamine) provided diastereoselectively the cis‐configured 1,3‐dioxane 2 in good yields. The 1,3‐dioxane 2 represents a potent σ1 receptor ligand (Ki = 19 nM) with moderate selectivity over the σ2 subtype (Ki = 92 nM) and excellent selectivity against more than 60 other targets. Additionally the hERG K+ channel is not affected by 2. In the capsaicin assay 2 showed extraordinarily high analgesic activity with more than 70% analgesia at the very low dose of 0.25 mg/kg body weight, which indicates σ1 antagonistic activity. Since 2 does only interact with σ1 receptors, the in‐vivo antiallodynic activity of 2 must be attributed to the σ1 antagonistic activity.
Extending consumer categorization based on innovativeness: Intentions and technology clusters in consumer electronics
Authors: van Rijnsoever Frank J. , Castaldi Carolina
Published: May 2011

Consumer categorizations based on innovativeness were originally proposed by E.M. Rogers (2003) and remain of relevance for predicting purchasing behavior in high‐tech domains such as consumer electronics. We extend such innovativeness‐based categorizations in two directions: We first take into account the existence of technology clusters within product domains and then enrich the definition of consumer innovativeness by considering not only past adoption behavior but also future purchase intentions. We derive a novel consumer categorization based on data from a sample of 2,094 Dutch consumers for the case of consumer electronics. In so doing, we apply endogenous categorization techniques that represent a methodological improvement with respect to previously applied techniques.
Determining the impact of climate and soil variability on switchgrass (Panicum virgatum L.) production in the south‐eastern USA; a simulation study
Authors: Persson Tomas , Ortiz Brenda V. , Bransby David I. , Wu Wei , Hoogenboom Gerrit
Published: May 2011

Switchgrass (Panicum virgatum L.) is a perennial warm‐season grass native to North America. The species is currently being evaluated as a potential feedstock for bioenergy. Growth and yield of switchgrass vary substantially due to weather and soil conditions. The objective of this study was to determine the impact and implications of weather, climate, and soil variability on switchgrass production in the south‐eastern USA using a crop simulation model. We simulated switchgrass growth and yield as a function of weather, soil, and crop management with the Agricultural Land Management Alternative with Numerical Assessment Criteria (ALMANAC) model. The model was first evaluated with switchgrass data from five field experiments conducted throughout Alabama. Subsequently, switchgrass growth and yield were simulated for climate and soil conditions representing the Tennessee River Valley region of northern Alabama and Georgia. Based on the simulations, we evaluated switchgrass production potential in this region under different climate and land‐use scenarios. Weather data from the 1950s, 1960s, and 1980s were included to account for the climate variability during the twentieth century. The average annual simulated switchgrass yield across the region was significantly (P < 0.05) higher for the 1950s (13 740 kg d.m. ha−1) and the 1980s' climate (14 162 kg d.m. ha−1) than for the 1960s' climate (12 492 kg d.m. ha−1). The annual production potential for the region ranged from 64 977 and 83 915 metric t due to spatial variability in climate and soil conditions. Using results and implementing the approach from this study can help plan switchgrass‐based bioenergy systems. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd
Sustainability Governance Across Time and Space: Connecting Environmental Stewardship in the Firm with the Global Community
Authors: Heuer Mark
Published: May 2011

To differentiate ecosystem management, three models of firm‐level environmental stewardship are paired with three types of trust, which serve as informal governance mechanisms. The interconnectedness of organizational fields and the influence of intertemporality and interspatiality (time and space) are key dynamics in developing decentralized networks as an approach for linking firms, organizational fields, and global sustainability efforts. Interviews with 18 firms, government agencies, and nonprofit‐making organizations from Japan and the USA are utilized to discuss the key concepts in the paper. Copyright © 2011 John Wiley & Sons, Ltd and ERP Environment.
Influences on Sustainable Innovation Adoption: Evidence from Leadership in Energy and Environmental Design
Authors: Gauthier Jeffrey , Wooldridge Bill
Published: May 2011

The adoption of innovations associated with environmental sustainability has been a topic of growing interest among scholars. The research presented in this paper draws on Abrahamson's theoretical framework of fads and fashions to argue that dimensions of uncertainty and degree of external versus internal influence provide significant insights into firms' decisions to adopt sustainable building innovations. We develop three hypotheses, reflecting three views of adoption influence: fad, fashion, and efficient‐choice. We find that adoption of Leadership in Energy and Environmental Design (LEED) green building certification in the United States was more likely among firms similarly oriented toward end‐consumers and among firms strategically positioned as environmental leaders. These results provide support for the fad and efficient‐choice views of adoption, respectively. Contrary to expectations suggested by the fashion perspective, adoption was not more likely among firms located in states whose political leaders are more committed to environmental protection. Our findings offer important implications for practitioners and policy makers seeking to encourage sustainable building design. Copyright © 2011 John Wiley & Sons, Ltd and ERP Environment.
Photoreactor design and CFD modelling of a UV/H2O2 process for distillery wastewater treatment
Authors: Mohajerani Masroor , Mehrvar Mehrab , Ein‐Mozaffari Farhad
Published: May 2011

A pseudo‐kinetic model for the treatment of a distillery wastewater by the ultraviolet irradiation and hydrogen peroxide process in a continuous tubular photoreactor is developed. There is a scarcity of information on modelling of organic degradation rates based on chemical oxygen demand (COD) and total organic carbon (TOC) in advanced oxidation technologies (AOTs). In this study, the COD and TOC are used as surrogate parameters to design a photoreactor instead of individual concentrations of species. The rate constants for the reaction between COD and TOC with hydroxyl radicals were determined to be 4.9 × 109 and 5.0 × 106 M−1 s−1, respectively. A laminar flow model was simulated to estimate the velocity and residence time of the medium in a cylindrical photoreactor. The model was validated by the experimental data published in the open literature for different concentrations of H2O2 (1, 10, and 100 mM), COD (589, 709, and 850 mg O2 L−1), and TOC (190, 200, and 192 mg C L−1). The optimal value of the inlet hydrogen peroxide concentration was predicted to be 400 mg L−1. Axial and radial concentration distributions of species in the photoreactor were also obtained. At different photoreactor radii (from 50 to 200 mm), the values of radial local volumetric rate of energy absorption (LVREA) were estimated. It was found that a higher LVREA was achieved in the photoreactor space at smaller radii. © 2011 Canadian Society for Chemical Engineering
Vapor‐liquid equilibria at high temperatures: The selenium‐tellurium system
Authors: Yannopoulos J. C. , Themelis N. J.
Published: May 2011

The vapor‐liquid phase equilibria for the system selenium‐tellurium were determined in the composition range of 40% to 99.999% by weight. Measurements were made by means of a dynamic distillation apparatus at atmospheric pressure and boiling temperatures from 688° to 773°C.

Under the above experimental conditions, selenium and tellurium are known to exist in a number of molecular forms, such as Se2, Se4, etc. It was, therefore, necessary to estimate the average molecular weights of the two elements on the basis of published data. An attempt was made to test the thermodynamic consistency of the equilibrium data. The activity coefficient plots were used to extend the experimental x‐y data over most of the composition range.
Laminar heat transfer to non‐Newtonian fluids in the entrance region of a circular conduit
Authors: Pawlek Richard A. , Tien Chi
Published: May 2011

An analytical study of the laminar heat transfer to a power‐law non‐Newtonian fluid in the entrance region of a circular conduit was made. Numerical values of local Nusselt number as well as average Nusselt number were evaluated and shown to be dependent upon Reynolds number, Prandtl number, the parameter z/R and the flow behavior index, n.
Distribution Study of U, V, Mo, and Zr in Different Sites of Lakes Van and Hazar, River and Seawater Samples by ICP‐MS
Authors: Yaman Mehmet , Ince Muharrem , Erel Ensar , Cengiz Emine , Bal Tulin , Er Cigdem , Kilicel Fevzi
Published: May 2011

The aim of this study is to investigate the concentrations of U, Th, V, Mo, and Zr in natural waters taken from Turkey. Among these water species, Lake Van is the largest soda lake and the fourth largest closed basin on Earth. The water samples were collected from 51 locations between 2008 and 2009. The inductively coupled plasma‐MS was used for determinations. The obtained U and Zr concentrations are in the range of 37–110 µg L−1 and 17–78 µg L−1 in Lake Van and 0.53–0.81 µg L−1 and 0.15–0.19 µg L−1 in Lake Hazar, respectively. The concentration of uranium in other studied waters varies from the lowest 0.09 µg L−1 in Tigris (Dicle) river to the highest 4.0 µg L−1 in Mediterranean Sea water. Mean Mo and V concentrations in the studied water samples were found to be in ranges of 0.1–17 and 2.7–113 µg L−1, respectively. The obtained highest U concentration in Lake Van correlates with the highest Mo and Zr levels compared to the Lake Hazar and river waters. These results imply that there is a young occurrence of uranium minerals around Lake Van. It is concluded that there is about 50.000 ton of uranium in Lake Van water.
Kinetic Magnetic‐Field Effect Involving the Small Biologically Relevant Inorganic Radicals NO and O2.−
Authors: Karogodina Tatiana Y. , Dranov Igor G. , Sergeeva Svetlana V. , Stass Dmitry V. , Steiner Ulrich E.
Published: May 2011

Oxidation of dihydrorhodamine 123 (DHR) to rhodamine 123 (RH) by oxoperoxonitrite (ONOO−), formed through recombination of NO and O2.− radicals resulting from thermal decomposition of 3‐morpholinosydnonimine (SIN‐1) in buffered aerated aqueous solution at pH 7.6, represents a kinetic model system of the reactivity of NO and O2.− in biochemical systems. A magnetic‐field effect (MFE) on the yield of RH detected in this system is explored in the full range of fields between 0 and 18 T. It is found to increase in a nearly linear fashion up to a value of 5.5±1.6 % at 18 T and 23 °C (3.1±0.7 % at 40 °C). A theoretical framework to analyze the MFE in terms of the magnetic‐field‐enhanced recombination rate constant krec of NO and O2.− due to magnetic mixing of T0 and S spin states of the radical pair by the Δg mechanism is developed, including estimation of magnetic properties (g tensor and spin relaxation times) of NO and O2.− in aqueous solution, and calculation of the MFE on krec using the theoretical formalism of Gorelik at al. The factor with which the MFE on krec is translated to the MFE on the yield of ONOO− and RH is derived for various kinetic scenarios representing possible sink channels for NO and O2.−. With reasonable assumptions for the values of some unknown kinetic parameters, the theoretical predictions account well for the observed MFE.
Electroless deposition of Cu dendrites decorated with ZnO rods
Authors: Wang L. , Liu G. , Xue D.
Published: May 2011

In this paper, copper dendrites decorated with ZnO rods have been electrolessly deposited on brass substrate by a simple galvanic replacement method. SEM images show that these copper dendrites possess a pronounced trunk and highly ordered branches distributed on both sides of the trunk. Meanwhile, both the trunk and branches are decorated with ZnO rods. The diffusion‐limited aggregation (DLA) model has been used to explain the fractal growth of Cu dendritic structures. This method provides a facile route to the synthesis of copper dendrites with ZnO, which can be extended to the preparation of other forms three‐dimensional (3‐D) metal structures or metal/ZnO composites by modifying electrolyte parameters such as composition, concentration, pH and temperature. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study of ammonium fluoride passivation time on CdZnTe bulk crystal wafers
Authors: Bensalah H. , Crocco J. , Carcélen V. , Plaza J. L. , Zheng Q. , Marchini L. , Zanichelli M. , Domínguez G. , Soriano L. , Diéguez E.
Published: May 2011

The chemical etching and the passivation processes of CdZnTe wafers were studied. The treatment effects were tested through an X‐Ray Photoelectron Spectroscopy (XPS) analysis and I–V measurement. The chemical etching in 2%Br–MeOH solution may effectively remove the damaged layer and improve the ohmic contact between CdZnTe wafer and Au electrodes making rich the surface with Te. After different etching times, the CdZnTe wafers were passivated with NH4F/H2O2.CdZnTe wafer passivated immediately after etching showed the best passivation efficiency because the enriched Te on the surface was fully oxidized to TeO2, which results in the thickest oxide layer, and the most stoichiometric surface. Also the surface leakage current was reduced in comparison with the sample passivated 24 h after etching. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Catalytic Conversion of Dihydroxyacetone to Lactic Acid Using Metal Salts in Water
Authors: Rasrendra Carolus B. , Fachri Boy A. , Makertihartha I. Gusti B. N. , Adisasmito Sanggono , Heeres Hero J.
Published: May 2011

We herein present a study on the application of homogeneous catalysts in the form of metal salts on the conversion of trioses, such as dihydroxyacetone (DHA), and glyceraldehyde (GLY) to lactic acid (LA) in water. A wide range of metal salts (26 in total) were examined. AlIII salts were identified as the most promising and essentially quantitative LA yields (>90 mol %) were obtained at 140 °C and a reaction time of 90 min. A reaction pathway is proposed and a kinetic model using the power law approach was developed for the conversion of DHA to LA with pyruvaldehyde (PRV) as the intermediate. Good agreement between experimental data and the model was obtained. Model predictions, supported by experiments, indicate that a high yield of LA is favoured in dilute solutions of DHA (0.1 M) at elevated temperatures (180 °C) and reaction times less than 10 min.
A Non‐Aqueous Synthesis of TiO2/SiO2 Composites in Supercritical CO2 for the Photodegradation of Pollutants
Authors: Jammaer Jasper , Aprile Carmela , Verbruggen Sammy W. , Lenaerts Silvia , Pescarmona Paolo P. , Martens Johan A.
Published: May 2011

Titania/silica composites with different Ti/Si ratios are synthesized via a nonconventional synthesis route. The synthesis involves non‐aqueous reaction of metal alkoxides and formic acid at 75 °C in supercritical carbon dioxide. The as‐prepared composite materials contain nanometer‐sized anatase crystallites and amorphous silica. Large specific surface areas are obtained. The composites are evaluated in the photocatalytic degradation of phenol in aqueous medium, and in the elimination of acetaldehyde from air. The highest photocatalytic activity in both processes is achieved with a composite containing 40 wt % TiO2.
Thin Films of Cobalt Oxide Deposited on High Aspect Ratio Supports by Atomic Layer Deposition
Authors: Diskus Madeleine , Nilsen Ola , Fjellvåg Helmer
Published: May 2011

Thin films of cobalt oxide are obtained by atomic layer deposition (ALD) using cobaltocene (CoCp2) and ozone as precursors. A window for ALD growth exists in the temperature range 137 to 331 °C. Self‐limiting growth is verified at a deposition temperature of 167 °C. X‐ray diffraction (XRD) analysis indicates that the films consist of polycrystalline Co3O4 up to a deposition temperature of some 285 °C with CoO being identified as a secondary phase at 331 °C. Atomic force microscopy (AFM) proves increased roughness and grain size with increasing deposition temperature, apart from films deposited at 235 °C where the roughness is very low due to a change in preferred orientation of the growth. Scanning electron microscopy (SEM) and energy dispersive X‐ray (EDX) mapping measurements on coated anodiscs show a homogeneous deposition of cobalt oxide on the 5 µm upper part of the pores structure. The content of cobalt decreases inside the pores, however, still proving the existence of cobalt inside all pores.
Monomer Crystallization During Vapor‐Deposition Polymerization
Authors: Papastrat Alexander G. , Chu Thach , Anthamatten Mitchell
Published: May 2011

Establishing control of molecular order, orientation, and the size of crystalline domains within thin films is crucial to engineering physical and charge‐transport properties. Vapor‐deposition polymerization of polyimides is accomplished by controlling incident molecular flux of sublimed dianhydrides and diamines. Crystallites containing unreacted monomer are observed when monomer fluxes are unbalanced. Diamine crystallites nucleate at early stages of deposition, grow radially during film growth, and are smaller at high deposition rates. Diamine crystallites protrude above the film, suggesting that monomer surface diffusion is significant. This high surface mobility likely promotes polymerization and explains other phenomena observed in vapor deposited films.
A new authenticated key agreement for session initiation protocol
Authors: Xie Qi
Published: May 2011

The session initiation protocol (SIP) is an authentication protocol used in 3G mobile networks. In 2009, Tsai proposed an authenticated key agreement scheme as an enhancement to SIP. Yoon et al. later pointed out that the scheme of Tsai is vulnerable to off‐line password guessing attack, Denning–Sacco attack, and stolen‐verifier attack and does not support perfect forward secrecy (PFS). Yoon et al. further proposed a new scheme with PFS. In this paper, we show that the scheme of Yoon et al. is still vulnerable to stolen‐verifier attack and may also suffer from off‐line password guessing attack. We then propose several countermeasures for solving these problems. In addition, we propose a new security‐enhanced authentication scheme for SIP. Our scheme also maintains low computational complexity. Copyright © 2011 John Wiley & Sons, Ltd.
My what big eyes you have: How the Drosophila retina grows
Authors: Kumar Justin P.
Published: May 2011

The compound eye of the fruit fly, Drosophila melanogaster, has for decades been used extensively to study a number of critical developmental processes including tissue development, pattern formation, cell fate specification, and planar cell polarity. To a lesser degree it has been used to examine the cell cycle and tissue proliferation. Discovering the mechanisms that balance tissue growth and cell death in developing epithelia has traditionally been the realm of those using the wing disc. However, over the last decade a series of observations has demonstrated that the eye is a suitable and maybe even preferable tissue for studying tissue growth. This review will focus on how growth of the retina is controlled by the genes and pathways that govern the specification of tissue fate, the division of the epithelium into dorsal‐ventral compartments, the initiation, and progression of the morphogenetic furrow and the second mitotic wave. © 2011 Wiley Periodicals, Inc. Develop Neurobiol 71: 1133–1152, 2011
Ongoing Dll4‐Notch signaling is required for T‐cell homeostasis in the adult thymus
Authors: Billiard Fabienne , Kirshner Jessica R. , Tait Michelle , Danave Amanda , Taheri Sean , Zhang Wen , Waite Janelle C. , Olson Kara , Chen Guoying , Coetzee Sandra , Hylton Donna , Murphy Andrew J. , Yancopoulos George D. , Thurston Gavin , Skokos Dimitris
Published: May 2011

The essential role of the Delta‐like ligand 4 (Dll4)‐Notch signaling pathway in T‐lymphocyte development is well established. It has been shown that specific inactivation of Dll4 on thymic stromal cells during early post‐natal development leads to a deregulation in T‐cell differentiation. However, whether ongoing Dll4‐Notch signaling is required for T‐cell development in the adult thymus is unknown. The use of anti‐Dll4 Abs allowed us to confirm and expand previous studies by examining the kinetics and the reversibility of Dll4‐Notch signaling blockade in T‐cell development in adult mice. We found that anti‐Dll4 treatment reduced thymic cellularity after 7 days, as a consequence of a developmental delay in T‐cell maturation at the pro‐T‐cell double negative 1 (CD4−CD8−c‐kit+CD44+CD25−) stage, leading to decreased numbers of immature double‐positive (CD4+CD8+) T cells without affecting the frequency of mature single positive CD4+ and CD8+ thymocytes, while promoting alternative thymic B‐cell expansion. This cellular phenotype was similarly observed in both young adult and aged mice (>1.5 years), extending our understanding of the ongoing role for Dll4‐Notch signaling during T‐cell development in the adult thymus. Finally, after cessation of Dll4 Ab treatment, thymic cellularity and thymocyte subset ratios returned to normal levels, indicating reversibility of this phenotype in both adult and aged mice, which has important implications for potential clinical use of Dll4‐Notch inhibitors.
A Protecting‐Group‐Free Route to Chiral BINOL–Phosphoric Acids
Authors: Li Baojian , Chiu Pauline
Published: May 2011

A two‐step, protecting group‐free route for the synthesis of 3,3′‐disubstituted and 6,6′‐disubstituted chiral BINOL–phosphoric acids has been realized starting from commercially available brominated BINOLs. This synthesis relies on the direct Suzuki coupling of brominated BINOL phosphoric acids. This synthetic strategy is more efficient compared to previous circuitous strategies involving protections and deprotections, and the process is higher yielding relative to the alternative two‐step synthesis involving Suzuki coupling of the BINOL.
Pedicled mandible myo‐osseous flaps combined with free skin flaps for reconstruction of complex lateral mandibular defects
Authors: Chen Yen‐Chou , Valerio Ian L. , Chien Chih‐Yen , Jeng Seng‐Feng
Published: May 2011

Background

This study presents an alternative in reconstruction, using free skin flaps in combination with pedicled mandible bone flaps for complex lateral mandibular defects.

Methods

In all, 13 patients were included in this prospective study. Pedicled mandible myo‐osseous flaps were used for reconstruction of bone defects of the lateral mandible in combination with free skin flaps, including radial forearm flaps (n = 3), anterolateral thigh (ALT) flaps (n = 9), and local tongue flap (n = 1). Postoperatively, a 99mTc‐methyl diphosphonate bone scan was performed to assess bone flap viability.

Results

All patients had acceptably contoured mandibles. The major complications consisted of 1 failed ALT flap and 2 nonviable bone flaps. The bone scan confirmed viable bone flaps in 11 cases. Ten patients (77%) were able to resume soft to full diets.

Conclusions

For complex lateral mandibular defects (≤6 cm), a combination of the pedicled mandible myo‐osseous flaps and free skin flaps is an alternative in reconstruction. © 2011 Wiley Periodicals, Inc. Head Neck, 2012
Depression in patients with head and neck cancer and a functional genetic polymorphism of the serotonin transporter gene
Authors: Gilbert Jill , Haman Kirsten L. , Dietrich Mary S. , Blakely Randy D. , Shelton Richard C. , Murphy Barbara A.
Published: May 2011

Background

Polymorphism of the serotonin transporter gene, 5‐HTTLPR (short allele) has been associated with depression. The purpose of this study was to show the evaluated depression in patients with head and neck cancer and a possible association with the 5‐HTTLPR.

Methods

The Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders (SCID for DSM‐IV) was administered to 94 patients with head and neck cancer, of which 33 patients were genotyped for 5‐HTTLPR. We also evaluated the prevalence of 5‐HTTLPR polymorphism in 121 patients with head and neck cancer and 97 controls.

Results

Forty‐three percent of the patients met the criteria for a depressive diagnosis, 19% of which was new onset. In depressed patients, 85.7% (n = 12 of 14) had at least 1 short allele versus 68.4% (n = 13 of 19) of the patients without depressive diagnosis (p < .04). No difference was noted in the prevalence of the short allele in head and neck cancer cases versus controls (odds ratio = 0.8; p = .490).

Conclusion

Despite the high rate of depressive diagnosis, patients with head and neck cancer did not demonstrate a higher prevalence of this short allele of the 5‐HTTLPR compared with a control population.© 2011 Wiley Periodicals, Inc. Head Neck, 2012
Initial staging of the neck in head and neck squamous cell carcinoma: A comparison of CT, PET/CT, and ultrasound‐guided fine‐needle aspiration cytology
Authors: Stoeckli Sandro J. , Haerle Stephan K. , Strobel Klaus , Haile Sarah R. , Hany Thomas F. , Schuknecht Bernhard
Published: May 2011

Background

The aim of this study was to compare imaging modalities for staging the neck in a prospective cohort of patients evaluated by CT, ultrasound with fine‐needle aspiration cytology (FNAC), and [18F]fluoro‐2‐deoxy‐D‐glucose (FDG) positron emission tomography (PET)/CT with the histologic evaluation of the neck dissection as the standard of reference.

Methods

In all, 76 consecutive patients were prospectively enrolled.

Results

Ultrasound‐guided FNAC showed the highest level of agreement with histology for exact N classification. Ultrasound‐guided FNAC showed the smallest percentage of overstaged patients, 7%, versus 16% with PET/CT, 13% with CT, and 13% with ultrasound. The rate of understaged patients was comparable between the imaging modalities. With regard to the endpoint N0 versus N+ there were no statistically significant differences to be found.

Conclusions

Ultrasound‐guided FNAC seems to correlate best with histologic staging compared with PET/CT and CT. None of the modality is reliable enough to replace elective neck treatment in cN0 necks. © 2011 Wiley Periodicals, Inc. Head Neck, 2012
Prognostic value of fluorine‐18 fluorodeoxyglucose positron‐emission tomography imaging in patients with head and neck squamous cell carcinoma
Authors: Querellou Solène , Abgral Ronan , Le Roux Pierre‐Yves , Nowak Emmanuel , Valette Gérald , Potard Gaël , Le Duc‐Pennec Alexandra , Cavarec Marie‐Béatrice , Marianovski Rémi , Salaün Pierre‐Yves
Published: May 2011

Background

High tumor uptake of fluorodeoxyglucose (FDG) is associated with an unfavorable outcome in patients with cancer. We evaluated FDG uptake as a prognostic factor in patients with head and neck squamous cell carcinoma.

Methods

Maximum standardized uptake values (SUVmax) of tumor, liver, and pulmonary artery were recorded. Ratios of SUVmax from tumor to liver (T/L) and from tumor to pulmonary artery (T/PA) were calculated for each patient. Clinical data, tumor, and SUVmax ratios were compared with disease‐free survival (DFS) and overall survival (OS).

Results

Eighty‐nine patients were included: 48 presented a local recurrent disease or distant metastases and 42 died. For both DFS and OS, tumor SUVmax value of 7 was the best cutoff value and 4 and 5 for T/L and T/PA ratios. Multivariate analysis confirmed the independent prognostic value of these 3 thresholds for DFS and OS.

Conclusions

FDG uptake has a significant and independent relationship with recurrence and survival. © 2011 Wiley Periodicals, Inc. Head Neck, 2012
A pathway from JNK through decreased ERK and Akt activities for FOXO3a nuclear translocation in response to UV irradiation
Authors: Wang Xianwang , Chen Wei R. , Xing Da
Published: May 2011

Forkhead box O (FOXO) transcription factors play an important role in physiological and pathological processes. Extracellular signal‐regulated kinase (ERK) and protein kinase B (Akt) can phosphorylate FOXO and cause its degradation or cytoplasmic retention, respectively, leading to tumorigenesis. In addition, C‐Jun N‐terminal protein kinase (JNK) can promote FOXO nuclear localization, leading to apoptosis. Using confocal imaging of cells transfected with GFP‐FOXO3a, we visualized the dynamic translocation of GFP‐FOXO3a from the cytoplasm to the nucleus after UV irradiation in a time‐ and dose‐dependent manner. We also found that UV irradiation caused activation of JNK, which in turn inactivated ERK and Akt, leading to FOXO3a translocation and Bim expression. Our results indicate that nuclear translocation of FOXO3a can be regulated by UV irradiation through the JNK‐ERK/Akt pathway. J. Cell. Physiol. 227: 1168–1178, 2012. © 2011 Wiley Periodicals, Inc.
Differential response of nucleus pulposus intervertebral disc cells to high salt, sorbitol, and urea
Authors: Mavrogonatou Eleni , Kletsas Dimitris
Published: May 2011

Nucleus pulposus intervertebral disc cells are routinely confronted with high osmolality in their microenvironment and respond to this stress in vitro by regulating cell cycle progression and by activating a DNA repair machinery in order to counteract its genotoxic effect. In the present study, we attempted to identify the origin of this osmo‐regulatory response, by using an ionic NaCl/KCl solution, the compatible osmolyte sorbitol, and the readily permeant urea. High salt and sorbitol were found to activate similar molecular pathways, including the p38 MAPK and the p53‐p21WAF1‐pRb axis, that were not stimulated by high urea. On the other hand, only high urea led to the phosphorylation of ERKs and JNKs. Furthermore, salt‐ and sorbitol‐treated cells were able to phosphorylate histone H2A.X on Ser139, in contrast to cells exposed to urea, indicating a common mechanism for DNA repair, which was achieved by a p53‐dependent activation of the G1 checkpoint by both solutes. DNA repair, as directly measured by a host cell reactivation assay, occurred under conditions of hyperosmolar salt and sorbitol, although to a lesser extent in sorbitol‐treated cells than in cells exposed to high salinity. Taken as a whole, our findings suggest that the hyperosmolality‐provoked DNA damage and the responses of nucleus pulposus cells induced by this genotoxic stress most probably originate from cell volume alterations mediated by hypertonicity and not from increased intracellular ionic concentration. J. Cell. Physiol. 227: 1179–1187, 2012. © 2011 Wiley Periodicals, Inc.
Sorafenib sensitizes hepatocellular carcinoma cells to physiological apoptotic stimuli
Authors: Fernando Joan , Sancho Patricia , Fernández‐Rodriguez Conrado M. , Lledó José L. , Caja Laia , Campbell Jean S. , Fausto Nelson , Fabregat Isabel
Published: May 2011

Sorafenib increases survival rate of patients with advanced hepatocellular carcinoma (HCC). The mechanism underlying this effect is not completely understood. In this work we have analyzed the effects of sorafenib on autocrine proliferation and survival of different human HCC cell lines. Our results indicate that sorafenib in vitro counteracts autocrine growth of different tumor cells (Hep3B, HepG2, PLC‐PRF‐5, SK‐Hep1). Arrest in S/G2/M cell cycle phases were observed coincident with cyclin D1 down‐regulation. However, sorafenib's main anti‐tumor activity seems to occur through cell death induction which correlated with caspase activation, increase in the percentage of hypodiploid cells, activation of BAX and BAK and cytochrome c release from mitochondria to cytosol. In addition, we observed a rise in mRNA and protein levels of the pro‐apoptotic “BH3‐domain only” PUMA and BIM, as well as decreased protein levels of the anti‐apoptotic MCL1 and survivin. PUMA targeting knock‐down, by using specific siRNAs, inhibited sorafenib‐induced apoptotic features. Moreover, we obtained evidence suggesting that sorafenib also sensitizes HCC cells to the apoptotic activity of transforming growth factor‐β (TGF‐β) through the intrinsic pathway and to tumor necrosis factor‐α (TNF) through the extrinsic pathway. Interestingly, sensitization to sorafenib‐induced apoptosis is characteristic of liver tumor cells, since untransformed hepatocytes did not respond to sorafenib inducing apoptosis, either alone or in combination with TGF‐β or TNF. Indeed, sorafenib effectiveness in delaying HCC late progression might be partly related to a selectively sensitization of HCC cells to apoptosis by disrupting autocrine signals that protect them from adverse conditions and pro‐apoptotic physiological cytokines. J. Cell. Physiol. 227: 1319–1325, 2012. © 2011 Wiley Periodicals, Inc.
Targeting of substance P induces cancer cell death and decreases the steady state of EGFR and Her2
Authors: Mayordomo Cristina , García‐Recio Susana , Ametller Elisabet , Fernández‐Nogueira Patricia , Pastor‐Arroyo Eva María , Vinyals Laia , Casas Ignasi , Gascón Pedro , Almendro Vanessa
Published: May 2011

NK1 is a tachykinin receptor highly relevant to tumorigenesis and metastasis development in breast cancer and other carcinomas. Despite the substantial efforts done to develop potent NK1 receptor antagonists, none of these antagonists had shown good antitumor activity in clinical trials. Now, we have tested the effect of inhibition of the neuropeptide Substance P (SP), a NK1 ligand, as a potential therapeutic approach in cancer. We found that the inhibition of SP with antibodies strongly inhibit cell growth and induce apoptosis in breast, colon, and prostate cancer cell lines. These effects were accompained by a decrease in the mitogen‐activated kinase singaling pathway. Interestingly, in some cell lines SP abrogation decreased the steady state of Her2 and EGFR, suggesting that SP‐mediated signaling is important for the basal activity of these ErbB receptors. In consequence, we observed a blockade of the cell cycle progression and the inhibition of several cell cycle‐related proteins including mTOR. SP inhibition also induced cell death in cell lines resistant to Lapatinib and Trastuzumab that have increased levels of active Her2, suggesting that this therapeutic approach could be also effective for those cancers resistant to current anti‐ErbB therapies. Thus, we propose a new therapeutic strategy for those cancers that express NK1 receptor and/or other tachykinin receptors, based in the immuno‐blockade of the neuropeptide SP. J. Cell. Physiol. 227: 1358–1366, 2012. © 2011 Wiley Periodicals, Inc.
Effect of indigenous mycorrhizal colonization on phosphorus‐acquisition efficiency in soybean and sunflower
Authors: Cecilia Fernández Mariana , Hernán Gutiérrez Boem Flavio , Rubio Gerardo
Published: May 2011

Despite a general consent about the beneficial contribution of arbuscular mycorrhizal fungi (AMF) on natural ecosystems, there is an intense debate about their role in agricultural systems. In this work, soybean (Glycine max L.) and sunflower (Helianthus annuus L.) field plots with different P availabilities were sampled across the Pampean Region of Argentina (> 150 samples from Mollisols) to characterize the relationship between available soil P and indigenous mycorrhizal colonization. A subsequent pot experiment with soybean and sunflower was carried out to evaluate the effect of P supply (0, 12, and 52 mg P kg–1) and AMF inoculation on AMF colonization and crop responsiveness to P in a Mollisol. Both crops showed high AMF colonization in the field (average: 55% for soybean and 44% for sunflower). While mycorrhizal colonization in soybean was significantly and negatively related to available soil P, no such trends were apparent in sunflower. Also, total biomass was 3.5 and 2.0 times higher in mycorrhizal than in nonmycorrhizal pot‐grown soybean under low‐ and medium‐P conditions, respectively. Sunflower, on the other hand, did not benefit from AMF symbiosis under medium and high P supply. While mycorrhization stimulated P‐uptake efficiency in soybean, the generally high P efficiency in sunflower was not associated with AMF symbiosis.
Effects of residue location on soil organic matter turnover: results from an incubation experiment with 15N‐maize
Authors: Jacobs Anna , Helfrich Mirjam , Dyckmans Jens , Rauber Rolf , Ludwig Bernard
Published: May 2011

Differences in the mechanisms of storage and decomposition of organic matter (OM) between minimum tillage (MT) and conventional tillage (CT) are generally attributed to differences in the physical impact through tillage, but less is known about the effects of residue location. We conducted an incubation experiment at a water content of 60% of the maximum water‐holding capacity and 15°C with soils from CT (0–25 cm tillage depth) and MT fields (0–5 cm tillage depth) with 15N‐labeled maize straw incorporated to different depths (CT simulations: 0–15 cm; MT simulations: 0–5 cm) for 28 d in order to determine the effects of the tillage simulation on (1) mineralization of recently added residues, (2) the dynamics of macroaggregate formation and physical protection of OM, and (3) the partitioning of maize‐derived C and N within soil OM fractions. The MT simulations showed lower relative C losses, and the amount of maize‐C mineralized after 28 d of incubation was slightly but significantly lower in the MT simulations with maize added (MTmaize) than in the respective CT (CTmaize) simulations. The formation of new water‐stable macroaggregates occurred during the phase of the highest microbial activity, with a maximum peak 8 d after the start of incubation. The newly formed macroaggregates were an important location for the short‐term stabilization of C and N with a higher importance for MTmaize than for CTmaize simulations. In conclusion, our results suggest that a higher amount of OM in MT surface soils compared with CT surface soils may not only result from decreased macroaggregate destruction under reduced tillage but also from a higher efficiency of C retention due to a more concentrated residue input.
Risk factors for long-term mortality in a large cohort of patients wait-listed for liver transplantation in Brazil
Authors: Basto Samanta T. , Villela-Nogueira Cristiane A. , Tura Bernardo R. , Coelho Henrique Sergio M. , Ribeiro Joaquim , Fernandes Eduardo S. M. , Schmal Alice F. , Victor Livia , Luiz Ronir R. , Perez Renata M.
Published: May 2011

Liver donor shortage and long waiting times are observed in many liver transplant programs worldwide. The aim of this study was to evaluate the wait list in a developing country, before and after the introduction of the MELD scoring system. In addition, the MELD score ability to predict mortality in this setting was assessed. A single-center retrospective study of patients wait-listed for liver transplantation between 1997 and 2010 was undertaken. There were 1339 and 762 patients on the list in pre-MELD and MELD era, respectively. A competitive risk analysis was performed to assess age, gender, disease diagnosis, serum sodium, MELD, Child-Pugh, ABO type, and body mass index. Also, MELD score predictive ability at 3, 6, 12, and 24 months after list enrollment was evaluated. The overall mortality rates on waiting list were 31.0% and 28.1% (P = 0.16), and the median waiting times were 412 and 952 days (P < 0.001), in pre and MELD eras, respectively. The competitive risk analysis yielded the following significant P values for both eras: HCC (0.03 and <0.001), MELD (<0.001 and 0.002), sodium level (0.002 and <0.001), and Child-Pugh (0.02 and <0.001). The MELD mortality predictions at 3, 6, 12, and 24 months were similar. In conclusion, in a liver transplant program with long waiting times, the MELD system introduction did not improve mortality rate. In either pre and MELD eras, HCC diagnosis, serum sodium, Child-Pugh, and MELD were significant predictors of prognosis. Short- and long-term MELD based mortality predictions were similarly accurate. Strategies for increasing the liver donor pool should be implemented to improve mortality. Liver Transpl 17:1013–1020, 2011. © 2011 AASLD.