bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Spirocyclic C‐Arylglycosides and ‐Ribosides by Ruthenium‐Catalyzed Cycloaddition
Authors: Yamamoto Yoshihiko , Yamashita Ken , Hotta Tomitaka , Hashimoto Toru , Kikuchi Makoto , Nishiyama Hisao
Published: September 2007

Spirocyclic C‐arylglycosides were synthesized from the appropriately protected δ‐gluconolactones. Addition of lithium acetylide followed by glycosylation with 3‐(trimethylsilyl)propargyl alcohol converted the δ‐gluconolactones into silylated diynes. After desilylation, subsequent ruthenium‐catalyzed cycloaddition of the resultant diynes with alkynes or chloroacetonitrile gave spirocyclic C‐arylglycosides in good yields and selectivity. This strategy was also extended to the synthesis of spirocyclic C‐arylribosides from the known γ‐ribonolactone derivative. Moreover, silver‐catalyzed iodination of the sugar diynes followed by ruthenium‐catalyzed cycloaddition with acetylene delivered spirocyclic C‐iodophenylglycosides and ‐ribosides, which were subjected to palladium‐catalyzed CC bond‐forming reactions and copper‐catalyzed coupling with nitrogen heterocycles to lead to various derivatives.
A Cyclobutanone Analogue Mimics Penicillin in Binding to Isopenicillin N Synthase
Authors: Stewart Amanda C. , Clifton Ian J. , Adlington Robert M. , Baldwin Jack E. , Rutledge Peter J.
Published: September 2007

A carbocyclic analogue of the β‐lactam antibiotic isopenicillin N (IPN) has been synthesised and cocrystallised with isopenicillin N synthase (IPNS), the central enzyme in the biosynthesis of penicillin antibiotics. The crystal structure of the IPNS‐cyclobutanone complex reveals an active site environment similar to that seen in the enzyme–product complex generated by turnover of the natural substrate within the crystalline protein. The IPNS–cyclobutanone structure demonstrates that the product analogue is tethered to the protein by hydrogen bonding and salt bridge interactions with its carboxylate groups, as seen previously for the natural substrate and product. Furthermore, the successful cocrystallisation of this analogue with IPNS provides firm structural evidence for the utility of such cyclobutanone derivatives as hydrolytically stable analogues of bicyclic β‐lactams.
Comparison of Two Kinds of Bed Materials During CFB Combustion of Cotton Stalk
Authors: Liu R.‐P. , Jin B.‐S. , Zhong Z.‐P.
Published: September 2007

Silica and aluminous soil were used as bed materials for the combustion of cotton stalk in a Circulating Fluidized Bed (CFB) combustion pilot plant (0.2 MW). After a long period of operation, the silica bed material was found to have sintered and the aluminous soil bed material was found to have resisted sintering. The particles of both types of bed materials were sampled. Two instrumental approaches (XRF and SEM/EDS) were employed in order to identify structural reasons for the observed differences in sintering behavior between the two bed materials when they were used in the same experimental conditions. From these experiments it was proven that the aluminous soil particles eliminate the bed agglomeration. Although the aluminous soil particles were enriched with alkali metals and alkaline‐earth metals after burning for 38 h, they still did not form any agglomerates. Therefore, these particles should provide a good bed material to substitute for the traditional silica bed materials in the CFB combustion of biomass with alkali ashes.
Numerical Simulation of Forced Convection in a Porous Circular Tube with Constant Wall Heat Flux: An Extended Graetz Problem with Viscous Dissipation
Authors: Tada S. , Ichimiya K.
Published: September 2007

Thermal development of forced convection in a circular tube filled with a saturated porous medium, subjected to the constant wall heat flux with a step change including the effect of viscous dissipation and the longitudinal heat conduction, has been studied numerically. Numerical computations for various values of the governing independent parameters, the Peclet number, Pe, the Darcy number, Da, the Brinkman number, Br, and the thermal conductivity ratio, Γ, were performed to disclose the influence of these parameters on the thermal behavior of flow through the corresponding porous circular tube. Results show that the presence of the viscous dissipation significantly elevates the level of the wall temperature, especially in the downstream region where the wall heat flux is uniformly applied. The local Nusselt number exhibits a monotonically increasing characteristic with the increase in the value of Γ. Results also show that the effect of the thermal conductivity ratio, Γ, alters the rate of the wall temperature evolution along the flow direction as well as the transversal profile of the temperature. This implies that the heat transfer is strongly controlled by conduction, and this is significant when the value of the Peclet number, Pe, is small.
Reduction of Nitrogen Oxides by Ammonia Over Iron‐Containing Catalysts
Authors: Jan M. T. , Kureti S. , Hizbullah K. , Jan N.
Published: September 2007

Selective catalytic reduction (SCR) of NOx by NH3 is an efficient technology for the removal of nitrogen oxides from diesel exhaust. It is a disadvantage that the active component in commercial catalysts, V2O5, is toxic and melts at ∼650 °C. An alternative catalyst system, based on iron as the active component, was developed in this work. For this purpose, a number of supports were taken and impregnated with Fe2O3 and Fe2O3/WO3 by an incipient wetness technique. The synthesized catalysts were tested in a diesel model exhaust using temperature programmed reaction. The screening accomplished to date, resulted in a 5.8 mol.‐% Fe2O3/Al2O3 catalyst that exhibited outstanding activity in the temperature range between 150–375 °C with selective formation of N2. However, this catalyst was significantly deactivated by thermal aging at 600 °C. In contrast, the activity of the sample with 1.4 mol.‐% Fe2O3 and 0.8 mol.‐% WOx showed very high thermal stability as well as selective N2 production over the whole temperature regime, but it had lower SCR activity.
Numerical Investigations of Fluid Flow and Lateral Fluid Dispersion in Bounded Granular Beds in a Cylindrical Coordinates System
Authors: Soleymani A. , Turunen I. , Yousefi H. , Bastani D.
Published: September 2007

Results are presented from a numerical study examining the flow of a viscous, incompressible fluid through a random packing of non‐overlapping spheres at moderate Reynolds numbers, spanning a wide range of flow conditions for porous media. By using a laminar model including inertial terms and assuming rough walls, numerical solutions of the Navier‐Stokes equations in three‐dimensional porous packed beds resulted in dimensionless pressure drops in excellent agreement with those reported in a previous study. This observation suggests that no transition to turbulence could occur in the range of the Reynolds number studied. For flows in the Forchheimer regime, numerical results are presented of the lateral dispersivity of solute continuously injected into a three‐dimensional bounded granular bed at moderate Peclet numbers. In addition to numerical calculations, to describe the concentration profile of solute, an approximate solution for the mass transport equation in a bounded granular bed in a cylindrical coordinates system is proposed. Lateral fluid dispersion coefficients are then calculated by fitting the concentration profiles obtained from numerical and analytical methods. Comparing the present numerical results with data available in the literature, no evidence has been found to support the speculations by others for a transition from laminar to turbulent regimes in porous media at a critical Reynolds number.
Intensification of Rate of Diffusion Controlled Reactions in a Parallel Plate Electrochemical Reactor Stirred by a Curtain of Electrochemically Generated Gas Bubbles
Authors: Sedahmed G. H. , Nirdosh I.
Published: September 2007

Rates of mass transfer were measured at a vertical plate stirred by a rising curtain of oxygen bubbles generated electrochemically at an upstream plate by measuring the limiting current of the cathodic reduction of K3Fe(CN)6 in alkaline solution. The rate of mass transfer was found to increase over the natural convection value by a factor ranging from 2.4 to 25 compared to the previously reported range of 2–5 in the case of copper deposition from acidified solutions. The high tendency of oxygen bubbles to coalesce in alkaline solutions is believed to be responsible for the high rates of mass transfer in alkaline solutions. The rate of mass transfer at a plate stirred by a curtain of oxygen bubbles was found to decrease with increasing plate height and electrolyte concentration. Curtains of H2 bubbles were found to be less effective in enhancing the rate of mass transfer compared to that of oxygen. Practical application of the results in designing a modified parallel plate electrochemical reactor stirred by a counterelectrode gas curtain was highlighted. The suggested design has the potential of saving part or all of the mechanical stirring energy as well as floor space since it extends vertically.
Inline Concentration Monitoring of Binary Liquid Mixtures in the Presence of a Dispersed Gas Phase with a Modified Speed of Sound Immersion Probe
Authors: Machefer S. , Schnitzlein K.
Published: September 2007

A commercial speed of sound (SOS) immersion probe has been modified in order to permit concentration measurements of liquid mixtures in the presence of dispersed gas phases. Experiments were performed in which water was removed from a polymer/water mixture via evaporation and stripping in mixed vessels of different flow patterns. The original and modified SOS immersion probe was used to monitor the water concentration. In the stripping stage, where a persistent gas phase of high volume fraction is generated, the original SOS immersion probe fails to measure the water concentration. This drawback has been successfully eliminated by means of a special SOS probe housing. The modified SOS immersion probe showed reliable inline water concentration monitoring for directed (draft tube reactor) and undirected flow pattern (ordinary stirred reactor) under boiling and stripping conditions.
Environmental Factors Differently Affect Human and Rat IAPP: Conformational Preferences and Membrane Interactions of IAPP17–29 Peptide Derivatives
Authors: Pappalardo Giuseppe , Milardi Danilo , Magrì Antonio , Attanasio Francesco , Impellizzeri Giuseppe , La Rosa Carmelo , Grasso Domenico , Rizzarelli Enrico
Published: September 2007

Interest in the 37‐residue human islet amyloid polypeptide (hIAPP) is related to its ability to form amyloid deposits in patients affected by type II diabetes. Attempts to unravel the molecular features of this disease have indicated several regions of this polypeptide to be responsible for either the ability to form insoluble fibrils or the abnormal interaction with membranes. To extend these studies to peptides that enclose His18, whose ionization state is believed to play a key role in the aggregation of hIAPP, we report on the synthesis of two peptides, hIAPP17–29 and rIAPP17–29, encompassing the 17–29 sequences of human and rat IAPP, respectively, as well as on their conformational features in water and in several membrane‐mimicking environments as revealed by circular dichroism (CD) and 2D‐NMR studies. hIAPP17–29 adopts a β‐sheet structure in water and its solubility increases at low pH. Anionic sodium dodecyl sulfate (SDS) micelles promoted the formation of an α‐helical structure in the peptide chain, which was poorly influenced by pH variations. rIAPP17–29 was soluble and unstructured in all the environments investigated, with a negligible effect of pH. The membrane interactions of hIAPP17–29 and rIAPP17–29 were assessed by recording differential scanning calorimetry (DSC) measurements aimed at elucidating the peptide‐induced changes in the thermotropic behaviour of zwitterionic (DPPC) and negatively charged (DPPC/DPPS 3:1) model membranes (DPPC=1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine, DPPS=1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphoserine). Results of DSC experiments demonstrated the high potential of hIAPP17–29 to interact with DPPC membranes. hIAPP17–29 exhibited a negligible affinity for negatively charged DPPC/DPPS model membranes at neutral pH. On the other hand, rIAPP17–29 did not interact with neutral or negatively charged membranes. The role played by His18 in the modulation of the biophysical properties of this hIAPP region was assessed by synthesising and studying the R18HrIAPP17–29 peptide; the replacement of a single Arg with a His residue is not sufficient to induce either amyloidogenic propensity or membrane interaction in this region. The results show that the 17–29 domain of hIAPP has many properties of the full‐length protein “in vitro” and this opens up new perspectives for both research and eventually therapy.
General Synthesis Route to Benanomicin‐Pradimicin Antibiotics
Authors: Tamiya Minoru , Ohmori Ken , Kitamura Mitsuru , Kato Hirohisa , Arai Tadamasa , Oorui Mami , Suzuki Keisuke
Published: September 2007

A general approach to the regio‐ and stereoselective total synthesis of the benanomicin‐pradimicin antibiotics (BpAs) is described. Construction of the aglycon has been achieved by 1) the diastereoselective ring‐opening of a biaryl lactone by using (R)‐valinol as a chiral nucleophile and 2) the stereocontrolled semi‐pinacol cyclization of the aldehyde acetal by using SmI2 in the presence of BF3⋅OEt2 and a proton source to afford the ABCD tetracyclic monoprotected diol. This strategy enabled us to control the two stereogenic sites in the B ring (C‐5 and C‐6) and the regioselective introduction of the carbohydrate moiety. The ABCD tetracycle could serve as an ideal platform for the divergent access to various BpAs. The amino acid (D‐alanine) was introduced onto the ABCD tetracycle. Glycosylation was promoted by the combination of Cp2HfCl2 and AgOTf (1:2 ratio). Construction of the E ring followed by deprotection completed the first total synthesis of benanomicin A (2 a), benanomicin B (2 b), and pradimicin A (1 a). The route is flexible enough to allow the synthesis of other congeners differing in their amino acid and carbohydrate moieties.
Concise Asymmetric Total Synthesis of Scyphostatin, a Potent Inhibitor of Neutral Sphingomyelinase
Authors: Fujioka Hiromichi , Sawama Yoshinari , Kotoku Naoyuki , Ohnaka Takuya , Okitsu Takashi , Murata Nobutaka , Kubo Ozora , Li Ruichuan , Kita Yasuyuki
Published: September 2007

The concise asymmetric total synthesis of scyphostatin has been achieved by condensation of the optically active cyclohexane unit, prepared from the commercially available 1,4‐cyclohexadiene by our own method, and the side chain, prepared by the method developed by Hoye and Tennakoon (T. R. Hoye, M. A. Tennakoon, Org. Lett. 2000, 2, 1481–1483). The modification of the epoxy cyclohexenone unit was achieved in a late stage of the total synthesis, and deprotection of the primary alcohol was conducted in the final step. During the synthesis several key reactions were attained: 1) intramolecular bromoetherification of the cyclohexadiene acetal; 2) stereoselective introduction of the tertiary alcohol, 3) deprotection of the acetal function to the aldehyde by combination with silyl triflate/2,4,6‐collidine and the one‐pot synthesis of the disilyl aldehyde compounds, with different types of silyl groups, from the dihydroxy acetal compounds; and 4) facile deprotection of the 2,4‐dimethoxyphenylmethyl (2,4DMPM) protecting group of the primary alcohol.
ETS‐family genes in pancreatic development
Authors: Kobberup Sune , Nyeng Pia , Juhl Kirstine , Hutton John , Jensen Jan
Published: September 2007

ETS‐family factors play major roles in development and cancer, notably as critical targets for extra‐cellular signaling pathways, including MAPK‐signaling. Given the presently limited knowledge on the role of ETS‐factors in pancreatic development, we here sought to characterize all 26 individual members of the ETS‐family in relation to pancreatic development using a combination of genomics, RT‐PCR, and histological techniques. This analysis uncovers 22 ETS family genes displaying select spatial and temporal expression patterns in the developing pancreas. Highly specific expression of ETS‐family components is observed in pancreatic progenitor cells or the associated embryonic mesenchyme. Other members are linked to the differentiation of more mature pancreatic cells, including exocrine and endocrine cell types. We find that two members of the Etv subfamily, Etv4 and Etv5, are expressed in cells proximal to pancreatic mesenchyme, and, furthermore, induced in FGF10‐arrested pancreatic progenitors suggesting that these factors mediate mesenchymal‐to‐epithelial signaling. Developmental Dynamics 236:3100–3110, 2007. © 2007 Wiley‐Liss, Inc.
Focal gene misexpression in zebrafish embryos induced by local heat shock using a modified soldering iron
Authors: Hardy Melissa E. , Ross Louis V. , Chien Chi‐Bin
Published: September 2007

Misexpression of genes in a temporally and spatially controlled fashion is an important tool for assessing gene function during development. Because few tissue‐specific promoters have been identified in zebrafish, inducible systems such as the Cre/LoxP and Tet repressor systems are of limited utility. Here we describe a new method of misexpression: local heat shock using a modified soldering iron. Zebrafish carrying transgenes under the control of a heat shock promoter (hsp70) are focally heated with the soldering iron to induce gene expression in a small area of the embryo. We have validated this method in three stable transgenic lines and at three developmental timepoints. Local heat shock is a fast, easy, and inexpensive method for gene misexpression. Developmental Dynamics 236:3071–3076, 2007. © 2007 Wiley‐Liss, Inc.
The Spectroscopic, Electrochemical and Structural Characterization of a Family of Ru Complexes Containing the C2‐Symmetric Didentate Chiral 1,3‐Oxazoline Ligand and Their Catalytic Activity
Authors: Sala Xavier , Santana Naiara , Serrano Isabel , Plantalech Elena , Romero Isabel , Rodríguez Montserrat , Llobet Antoni , Jansat Susanna , Gómez Montserrat , Fontrodona Xavier
Published: September 2007

The structural, spectroscopic, and electrochemical characterization and a preliminary catalytic investigation of a family of RuII complexes with general formula [Ru(Y)(terpy)(phbox‐R)]n+ [where terpy is 2,2′:6′,2″‐terpyridine, phbox‐R is a C2‐symmetric bidentate oxazoline ligand (R = Et or iPr), and Y is a monodentate ligand], are discussed. The X‐ray structure of [RuCl(terpy)(phbox‐iPr)]2+ has been solved and confirms, as we described recently, the predicted generation of the less hindered atropisomer, which is determined by the conformation of the stereogenic centers in the bidentate ligand. The catalytic properties of the aquo complexes have been tested in epoxidation reactions, and moderate selectivity for the epoxides is obtained for styrene and trans‐stilbene when using PhI(OAc)2 as co‐oxidant. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Turbostratic Boron Nitride Coated on High‐Surface Area Metal Oxide Templates
Authors: Klitgaard Søren K. , Egeblad Kresten , Brorson Michael , Herbst Konrad , Christensen Claus H.
Published: September 2007

Boron nitride coatings on high‐surface area MgAl2O4 and Al2O3 have been synthesized and characterized by transmission electron microscopy and by X‐ray powder diffraction. The metal oxide templates were coated with boron nitride using a simple nitridation in a flow of ammonia starting from ammonium borate adsorbed on MgAl2O4 or γ‐Al2O3. This procedure resulted in the formation of a turbostraticboron nitride film with a thickness of a few individual BN layers.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Double Group Transfer Reactions as Indicators of Aromatic Stabilization
Authors: Frenking Gernot , Cossío Fernando P. , Sierra Miguel A. , Fernández Israel
Published: September 2007

The main features of double hydrogen atom transfer reactions insyn‐sesquinorbornanes, which involve the concomitant formation of an aromatic ring, have been studied computationally within the framework of Density Functional Theory. The very good linear correlations, which exhibit high correlation coefficients between the recently available Aromatic Stabilization Energies (ASE) from the Energy Decomposition Analysis (EDA) method and the activation and reaction energies, as well as geometric features (C–C bond lengths) of the corresponding transition states of the transformations, suggest that the calculated values are useful in estimating the aromatic character of a molecule. The studied process may be used for benchmarking of energetic aromatic indices. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
In vivo resorption of a biodegradable polyurethane foam, based on 1,4‐butanediisocyanate: A three‐year subcutaneous implantation study
Authors: van Minnen B. , van Leeuwen M.B.M. , Kors G. , Zuidema J. , van Kooten T.G. , Bos R.R.M.
Published: September 2007

Degradable polyurethanes (PUs), based on aliphatic diisocyanates, can be very useful in tissue regeneration applications. Their long‐term in vivo degradation has not been extensively investigated. In this study a biodegradable PU with copolyester soft segments of DL‐lactide/ϵ‐caprolactone and hard segments synthesized from 1,4‐butanediisocyanate was evaluated with regard to tissue response during degradation and, ultimately, the resorption of the material. Highly porous PU foam discs were subcutaneously implanted in rats and rabbits for intervals up to 3 years. A copolymer foam of DL‐lactide and ϵ‐caprolactone served as a control. The foams, the surrounding tissues and the draining lymph nodes were evaluated with light and electron microscopy. In the first stages of degradation the number of macrophages and giant cells increased. As the resorption stage set in their numbers gradually decreased. Electron microscopy showed macrophages containing pieces of PU. The size of the intracellular PU particles diminished and cells containing these remnants gradually disappeared after periods from 1 to 3 years. After 3 years an occasional, isolated macrophage with biomaterial remnants could be traced in both PU and copolymer explants. Single macrophages with biomaterial remnants were observed in the lymph nodes between 39 weeks and 1.5 years following implantation. It is concluded that the PU foam is biocompatible during degradation. After 3 years PU samples had been resorbed almost completely. These results indicate that the PU foam can be safely used as a biodegradable implant. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Improvement of survival of skin flaps by combined gene transfer of hepatocyte growth factor and prostacyclin synthase
Authors: Nakagawa Aya , Makino Hirofumi , Aoki Motokuni , Miyake Takashi , Shiraya Suguru , Nakamura Toshikazu , Ogihara Toshio , Kimata Yoshihiro , Morishita Ryuichi
Published: September 2007

Background

Increasing the local blood flow is a critical factor for long‐term survival of skin flaps. Thus, a molecular therapy to increase the blood flow by means of an angiogenic factor is considered to be a useful strategy to improve skin flap survival. We focused on a combined strategy to stimulate not only angiogenesis, but also vasodilation of local microvessels, using co‐transfection of the hepatocyte growth factor (HGF) and prostacyclin synthase (PGIS) genes to enhance the survival of random‐pattern skin flaps.

Methods and results

A 2 × 8 cm full thickness cranial pedicled random‐pattern flap was made on the back of each 12‐week‐old male rat. At 3 days before operation, 400 µg of human HGF and PGIS naked plasmid DNA or control plasmid was transfected into the flaps by needle‐less injection using a Shima Jet, resulting in successful expression of human HGF and PGIS in the skin flaps. Transfection of both genes into the distal half of skin flaps at 3 days prior to operation significantly increased the survival rate of skin flaps, while transfection all over the flaps did not. In addition, transfection prior to operation was more effective than simultaneous treatment. Moreover, co‐transfection of these genes improved the survival area of skin flaps, accompanied by an increase in blood flow of skin flaps, even in a diabetic model.

Conclusions

Overall, these results indicate that combination treatment with HGF and PGIS genes by Shima Jet could be an effective strategy to improve skin flap survival. Copyright © 2007 John Wiley & Sons, Ltd.
Targeting malignant gliomas with a glial fibrillary acidic protein (GFAP)‐selective oncolytic adenovirus
Authors: Horst Maarten ter , Brouwer Eric , Verwijnen Suzanne , Rodijk Mark , de Jong Marion , Hoeben Rob , de Leeuw Bertie , Smitt Peter Sillevis
Published: September 2007

Glial fibrillary acidic protein (GFAP) is an intermediate filament protein abundantly expressed in malignant gliomas. We have constructed a novel oncolytic adenovirus, Ad5‐gfa2(B)3‐E1, for treatment of these tumors. In this construct, the E1 region is under control of the tissue‐specific GFAP promoter (gfa2) with three additional copies of the glial specific ‘B’ enhancer. Infection of a GFAP‐positive cell line with Ad5‐gfa2(B)3‐E1 resulted in E1A and E1B expression at 75% and 30% of the levels obtained after wtAd5 infection. Q‐PCR showed that Ad5‐gfa2(B)3‐E1 replicated 4.5 times more efficiently in the GFAP‐positive than in the GFAP‐negative cell lines. Cell viability assays showed efficient elimination of GFAP‐positive cells by Ad5‐gfa2(B)3‐E1, in some cell lines as efficiently as wtAd5, while the elimination was attenuated in GFAP‐negative cell lines. When tested in human tumor xenografts in nude mice, Ad5‐gfa2(B)3‐E1 effectively suppressed the growth of GFAP‐positive SNB‐19 glial tumors but not of GFAP‐negative A549 lung tumors. In Ad5‐gfa2(B)3‐E1, the E3 region was deleted to create space for future insertion of heterologous therapeutic genes. Experiments with dl7001, an E3‐deleted variant of wtAd5, confirmed that the specificity of Ad5‐gfa2(B)3‐E1 replication was based on the promoter driving E1 and not on the E3 deletion. Strategies to further improve the efficacy of Ad5‐gfa2(B)3‐E1 for the treatment of malignant gliomas include the insertion of therapeutic genes in E3 or retargeting to receptors that are more abundantly expressed on primary glioma cells than CAR. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of temperature and water availability during late maturation of the soybean seed on germ and cotyledon isoflavone content and composition
Authors: Rasolohery Claudine A , Berger Monique , Lygin Anatoliy V , Lozovaya Vera V , Nelson Randall L , Daydé Jean
Published: September 2007

BACKGROUND:Isoflavone content in soybean seeds is strongly influenced by both environment and genotype. However, little is known about the effect of environment and genotype on isoflavones in germ versus cotyledons. To determine the effect of temperature and soil moisture status during soybean seed development on seed isoflavone concentration and composition, a set of two French and three US cultivars of similar maturity were grown in the greenhouse. At the R6 growth stage, plants were subjected to one of three night/day temperature regimes (13/23°, 18/28° or 23/33 °C) in either optimal or sub‐optimal soil water conditions.

RESULTS:In cotyledons, a three‐ to six‐fold variation in total isoflavone content was observed between the high and low temperature treatments, whereas the germ contents had less than a two‐fold variation. Soil water supply had less effect than temperature on the isoflavone contents and compositions. In both seed parts, the isoflavone concentrations were highly dependent on the cultivar.

CONCLUSION:These results show that isoflavone content and composition in cotyledon and germ are unrelated and it should be possible to independently manipulate these seed traits through plant breeding and crop management systems. Copyright © 2007 Society of Chemical Industry
Encapsulation of Inorganic Particles with Nanostructured Cellulose
Authors: Nelson Kimberly , Deng Yulin
Published: September 2007

Inorganic‐cellulose core‐shell and hollow cellulose nanoparticles were prepared by self‐encapsulation with regenerated cellulose in a poly(acrylic acid) hydrogel layer surrounding inorganic particle templates in N‐methylmorpholine oxide (NMMO) (4‐methylmorpholine N‐oxide) monohydrate solution. The hydrogel layer surrounding the inorganic particle surface plays a decisive role in the core‐shell formation. The core‐shell nanostructures were characterized using TEM, SEM, and X‐ray diffraction (XRD). The cellulose shell was found to be composed of cellulose spheres or nodules with dimensions of approximately 30 nm. Individual, regenerated cellulose nanoparticles were also synthesized by addition of nonsolvent under agitation to dilute solutions of cellulose dissolved in NMMO. The effects of the rate of addition of water (the nonsolvent) on the nanostructure, morphology and crystallinity of the regenerated cellulose nanoparticles were studied. The results indicate that the faster the water‐addition rate, the smaller the cellulose nanoparticles formed.

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Chain Walking Ethylene Copolymerization with an ATRP Inimer for One‐Pot Synthesis of Hyperbranched Polyethylenes Tethered with ATRP Initiating Sites
Authors: Zhang Kejian , Wang Jianli , Subramanian Ramesh , Ye Zhibin , Lu Jianmei , Yu Qiang
Published: September 2007

A one‐pot procedure for the synthesis of hyperbranched polyethylenes tethered with ATRP initiating sites by chain walking ethylene copolymerization with an acrylate‐type ATRP inimer, 2‐(2‐bromoisobutyryloxy) ethyl acrylate (BIEA) is reported. Because of its ability to incorporate acrylate‐type comonomers and tolerance toward the α‐bromoester group, the chain walking Pd‐diimine catalyst, [(ArNC(Me)(Me)CNAr)Pd(CH3)(NCMe)]SbF6 (Ar = 2,6‐(iPr)2C6H3), allowed the successful synthesis of a series of hyperbranched copolymers tethered with 2‐bromoisobutyryl groups at different densities. These copolymers may serve as polyfunctional macroinitiators for the ATRP of functional monomers to further synthesize core‐shell structured functionalized copolymers with a hyperbranched polyethylene core grafted with side chains of the functional monomers.

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Synergistic effects of expandable graphite with magnesium hydroxide on the flame retardancy and thermal properties of polypropylene
Authors: Chen Xiaolang , Wu Hong , Luo Zhu , Yang Bo , Guo Shaoyun , Yu Jie
Published: September 2007

In this study, the flammability characterization and synergistic effects of different particle size of expandable graphite (EG) with modified magnesium hydroxide (MH) in flame‐retardant polypropylene (PP) composites were studied by limiting oxygen index (LOI), UL‐94 test, thermogravimetric analysis (TGA), and fourier transform infrared (FTIR) spectroscopy. The results showed that the particle size of EG had a great effect on the flammability of the PP/MH/EG composites. The EG2 with smaller particle size could apparently increase the LOI value and improved the UL‐94 flammability properties rating of the PP composites. The data obtained from the TGA and FTIR curves indicated that the thermo‐oxidative stability of PP/MH/EG composites increased with decreasing particle size of EG. And the smaller the particle size of EG, the higher the residues of the composite. POLYM. ENG. SCI., 47:1756–1760, 2007. © 2007 Society of Plastics Engineers
Flexural and tensile moduli of polypropylene nanocomposites and comparison of experimental data to Halpin‐Tsai and Tandon‐Weng models
Authors: Kalaitzidou Kyriaki , Fukushima Hiroyuki , Miyagawa Hiroaki , Drzal Lawrence T.
Published: September 2007

This research focuses on the reinforcing efficiency of nanomateterials and the role of the reinforcement's dispersion and orientation on the nanocomposite's flexural and tensile moduli. Polypropylene‐based composites reinforced with (i) exfoliated graphite nanoplatelets, xGnP™, (ii) vapor grown carbon fibers, (iii) PAN‐based carbon fibers, (iv) highly structured carbon black and (v) montmorillonite clay were fabricated by extrusion and injection molding. It was found that graphite platelets are the best reinforcement in terms of flexural modulus whereas PAN‐based carbon fibers cause the largest improvement in the tensile modulus. The difference in the reinforcing efficiency during the flexural and tensile testing is attributed to (i) the degree of fiber alignment along the flow direction during injection molding, which is higher in the thinner tensile specimens than in the flex specimens; and (ii) the different deformation modes of the two tests. The importance of good dispersion of the reinforcements within the polymer matrix and of perfect contact between the two phases is emphasized comparing the experimental modulus data to theoretical predictions made using the Halpin‐Tsai and the Tandon‐Weng models. POLYM. ENG. SCI., 47:1796–1803, 2007. © 2007 Society of Plastics Engineers
Poly(ethylene terephthalate) nanocomposite fibers with new organomica via in situ intercalation
Authors: Jung Min‐Hye , Chang Jin‐Hae , Kim Jeong‐Cheol
Published: September 2007

Poly(ethylene terephthalate) (PET) nanocomposites with a newly synthesized organomica (C16BIMD‐Mica) were obtained by using the in situ interlayer polycondensation of ethylene glycol with dimethylterephthalic acid. The PET hybrids were melt‐spun to produce monofilaments with various organoclay contents and draw ratios. The thermomechanical properties and morphologies of the PET hybrid fibers were determined using differential scanning calorimetry, thermogravimetric analysis, wide angle X‐ray diffraction, electron microscopy (SEM and TEM), and a universal tensile machine. The XRD analyses and TEM micrographs showed that the levels of exfoliation and intercalation could be controlled by varying the clay content. The thermomechanical properties of the PET hybrid fibers were found to be better than those of pure PET fibers. POLYM. ENG. SCI., 47:1820–1826, 2007. © 2007 Society of Plastics Engineers
The effect of nanoclays on the nucleation, crystallization, and melting mechanisms of isotactic polypropylene
Authors: Medellín‐Rodríguez F.J. , Mata‐Padilla J.M. , Hsiao B.S. , Waldo‐Mendoza M.A. , Ramírez‐Vargas E. , Sánchez‐Valdes S.
Published: September 2007

The influence of organomodified nanoclay (montmorillonite) on the crystallization and melting mechanisms of isotactic polypropylene (iPP) was studied. Films of both neat polymer and clay nanocomposites were prepared after molecular weight optimization through melt extrusion. Products exhibited the tactoidlike morphology since no compatibilizers were used. The effect of introduction of nanoclay within the polymer was studied through isothermal crystallization and linear heating. The results indicated that low nanoclay concentrations induce the formation of the β‐crystalline structure, its formation being inhibited with high nanoclay contents. Dynamic nonisothermal bulk crystallization experiments indicated that nanoclays act as nucleating agents of iPP. Isothermal, bulk crystallization studies indicated that the crystallization process (induction time and crystallization kinetics) is proportionally accelerated by the nanoclay presence. There was also an accelerated formation of secondary crystallization when nanoclays were present in high concentrations. POLYM. ENG. SCI., 47:1889–1897, 2007. © 2007 Society of Plastics Engineers
Rheological, mechanical and thermal properties of propylene‐ethylene block copolymer/polyalphaolefins blends
Authors: Ha H.S. , Kang M.C. , Cho H.H. , Kim B.K.
Published: September 2007

The rheological, thermal, and mechanical properties of propylene–ethylene block copolymer (PPB) blends with predominantly atactic molecular structure of low molecular weight polypropylene and propylene copolymers with either ethylene or 1‐butene (APAO) have been studied. It has been found that blend properties depend on comonomer type, content, and molecular weight of APAO as well as blend composition. APAO having ethylene comonomer showed better miscibility with PPB than the other ones, and high comonomer content of APAOs gave dramatic increase in impact strength over 30 wt%. It has been concluded that APAO can be used as an effective modifier of PPB. POLYM. ENG. SCI., 47:1905–1911, 2007. © 2007 Society of Plastics Engineers
Excitonic transition energies in single‐walled carbon nanotubes: Dependence on environmental dielectric constant
Authors: Ohno Yutaka , Iwasaki Shinya , Murakami Yoichi , Kishimoto Shigeru , Maruyama Shigeo , Mizutani Takashi
Published: September 2007

The dependence of optical transition energies in single‐walled carbon nanotubes (SWNTs) on environmental dielectric constant (εenv) have been investigated in the range of εenv from 1.0 to 37, by immersing SWNTs bridged overtrenches in various organic solvents by means of photoluminescence (PL) and the excitation spectroscopies. With increasing εenv, both E11 and E22 exhibited a redshift by several tens meV and a tendency to saturate at a εenv ∼ 5 without an indication of significant (n,m) dependence. The redshifts can be explained by dielectric screening of the repulsive electron–electron interaction. We have also investigated the time‐resolved PL in air and in solvent, respectively, utilizing the excitation intensity correlation technique. When the sample was immersed in solvent, the correlation signal collapsed, and the decay time decrease as compared to in air. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic state of carbon in carbonaceous chondrite meteorites
Authors: Okotrub A. V. , Bulusheva L. G. , Guselnikov A. V. , Kolesov B. A. , Dikov Yu. P. , Molodtsov S. L.
Published: September 2007

Electronic state of carbon occurred in the carbonaceous chondrite meteorites has been probed using X‐ray emission (XES), X‐ray absorption (XAS), and X‐ray photoelectron (XPS) spectroscopy. The XES and XAS spectra of seven meteorites Orgueil, Mighei, Murchison, Murray, Staroe Boriskino, Isna, and Kainsaz were compared to the graphite and detonation nanodiamonds spectra. The carbon in the meteorites was found to be presented by the graphite‐like component mainly, which ratio to the diamond‐like component decreases with the meteorite age. The strong charging effect was found in the XPS C 1s‐spectra of the youngest meteorites Kainsaz and Isna that can be due to encapsulation of nanocarbon granules within the dielectric silicate matrix. The presence of the letter species in the chondrites was supported by Raman spectroscopy. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Progress in carbon nanotube based nanoelectromechanical systems synthesis
Authors: Jungen Alain , Durrer Lukas , Stampfer Christoph , Roman Cosmin , Hierold Christofer
Published: September 2007

We present a revised process flow for the integration of individual single‐walled carbon nanotubes into microelectromechanical systems. The revision consists in a re‐ordered process sequence which consider‐ably increases the device yield. Thermal catalytic chemical vapor deposition of single‐walled carbon nanotubes is performed conjunctly with annealing as the very last process step. Maskless catalyst deposition is demonstrated to produce individual single‐walled carbon nanotubes with good location and orientation control by shaping the catalyst support. Straining experiments showed that the mechanical anchoring between the tube and the support can be sufficient. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
New principle of hydrogen adsorption inside nanotubes
Authors: Fedorov A. S. , Kuzubov A. A.
Published: September 2007

A new principle of hydrogen (or other gases) adsorption inside single‐wall nanotubes is proposed. This principle is based on the mixing of hydrogen with a small quantity of special additive molecules. The diameter of these molecules is chosen to be 2.5–4 Å smaller than the nanotube diameter, so these molecules can move along the tube axis. Due to interaction of the molecules and the nanotube walls this molecular movement has potential barriers which should be ∼0.5–1 eV for the best effect. At those values the mobility of these molecules would be very low at ambient conditions. At high pressures and temperatures (600–900 K) the additive molecules have high mobility, so they can penetrate through open ends into nanotubes quite easily together with molecular hydrogen. These molecules divide the whole volume of the nanotube in separate parts in which the hydrogen molecular gas is locked under high pressure. The main part of the hydrogen is physically adsorbed on the inner walls of the nanotube. After decreasing the temperature the mobility of additive molecules is strongly decreased and hydrogen becomes accumulated inside all parts of the nanotube. As an example, hydrogen adsorption inside boron nitride nanotubes (8,8) is investigated. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermoelectric properties of CoSb3 with maize‐like structure
Authors: Li Shanghua , He Zeming , Toprak Muhammet S. , Stiewe Christian , Müller Eckhard , Muhammed Mamoun
Published: September 2007

Maize‐like CoSb3 powders were obtained via the chemical alloying method. After the consolidation of the nanopowder using hot press, the CoSb3 compact shows a higher Seebeck coefficient and lower thermal conductivity. For the investigated CoSb3, a ZT of 0.15 at 673 K is shown. Though the achieved ZT does not reach the optimal value (0.17 to 0.18) for pure CoSb3, due to its lower electrical conductivity, the novel structure fabrication provides an interesting and promising approach to enhancing the thermoelectric performance. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Strengthening emergency obstetric care in Thanh Hoa and Quang Tri provinces in Vietnam
Authors: Otchere S.A. , Binh H.T.
Published: September 2007

Objective

Save the Children/USA and the Ministry of Health of Vietnam undertook a project between 2001 and 2004 to improve the availability of, access to, quality and utilization of emergency obstetric care (EmOC) services at district and provincial hospitals in two provinces in Vietnam.

Methods

The project improved the functional capacity of 3 provincial and 1 district hospitals providing comprehensive EmOC services, and upgraded 1 district hospital providing basic EmOC into a comprehensive EmOC facility through training, infrastructure and quality improvement.

Results

Data presented in this paper focus on only the 2 district hospitals even though the UN process indicators showed increases in utilization of EmOC in all 5 hospitals. In the case of Hai Lang, the proportion of births increased from 13% at baseline to 31% at the end of 2004, and met need increased significantly from 16% to 87% largely due to increased capacity of the hospital and staff. Met need in Hoang Hoa hospital more than doubled (17% at baseline versus 54% in 2004) and the proportion of births increased slightly from 19% in 2001 to 22% in 2004. Case fatality rates for the two hospitals remarkably remained at zero. Lessons from this project have been incorporated into national policy and guidelines.

Conclusion

Improvements in the capacity of existing health facilities to treat complications in pregnancy and childbirth can be realized in a relatively short period of time and is an essential element in reducing maternal mortality.
Ensuring financial access to emergency obstetric care: Three years of experience with Obstetric Risk Insurance in Nouakchott, Mauritania
Authors: Renaudin P. , Prual A. , Vangeenderhuysen C. , Ould Abdelkader M. , Ould Mohamed Vall M. , Ould El Joud D.
Published: September 2007

Introduction: The high cost of emergency obstetric care (EmOC) is a catastrophic health expenditure for households, causing delay in seeking and providing care in poor countries. Methods: In Nouakchott, the Ministry of Health instituted Obstetric Risk Insurance to allow obstetric risk sharing among all pregnant women on a voluntary basis. The fixed premium (US$21.60) entitles women to an obstetric package including EmOC and hospital care as well as post‐natal care. The poorest are enrolled at no charge, addressing the problem of equity. Results: 95% of pregnant women in the catchment area (48.3% of the city's deliveries) enrolled. Utilization rates increased over the 3‐year period of implementation causing quality of care to decline. Basic and comprehensive EmOC are now provided 24/7. The program has generated US$382,320 in revenues, more than twice as much as current user fees. All recurrent costs other than salaries are covered. Conclusion: This innovative sustainable financing scheme guarantees access to obstetric care to all women at an affordable cost.
RETRACTED: Dexamethasone for reduction of nausea, vomiting and analgesic use after gynecological laparoscopic surgery
Authors: Fujii Y. , Nakayama M.
Published: September 2007

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).

This article has been retracted at the request of the Editor‐in‐Chief.

This article has been retracted as a result of evidence that the distributions of many variables reported by Dr Fujii in these studies could not have occurred by chance [1,2]; and the inability of Dr Fujii's institution, following investigation, to attest to the scientific propriety of the study and/or its data conducted under its auspices [3], as set out in the Joint Editor's‐in‐Chief Request for Determination of April 9, 2012 [4]:
China and the International Legal System: Challenges of Participation
Authors: Potter Pitman B.
Published: September 2007

During the past decade, the Chinese government has pursued greater engagement with a range of international legal regimes. China's expanded participation in international regimes for trade and human rights, for example, can provide deeper understanding of the factors influencing China's international behaviour. Building upon scholarly perspectives about institutional compliance with treaty texts and the influence of local conditions on China's policies and practice, this article examines China's participation in international legal regimes for trade and human rights in light of dynamics of normative engagement and the paradigm of selective adaptation. Normative tensions help explain China's policies and practices on compliance with the WTO trade regime, while the imperative of normative engagement helps explain much about China's international human rights diplomacy.