bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and properties of hydrophilic polymers, part 11: Synthesis, biodegradability, and metal complexation of copolymers of ethylenediaminetetraacetic acid dianhydride and lactose
Authors: Choi S. J. , Geckeler K. E. 
Published: December 2006

AbstractThe synthesis and characterization of poly(ethylenediaminetetraacetic acid‐co‐lactose) of high molar mass (132 kg mol−1) is described. The polycondensate with pendant carboxylic groups was shown to be hydrolytically and microbiologically degradable by using conventional microbiological methods. The metal complexing properties of the polyester were studied for Cr(III), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Sr(II), Cd(II), Pb(II), and Al(III) ions in aqueous solution using the liquid‐phase polymer‐based retention (LPR) method. In addition, the complexing capacity of the Cu(II)‐saturated copolymer was determined by TGA to be 182 mg g−1 polymer. According to the retention profiles determined as a function of filtration factor by using LPR in conjunction with inductively coupled plasma spectrometry, Cr(III) and Fe(III) showed a strong interaction with this polymer under these conditions, indicated by retention values of 100% at pH 5. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2932–2939, 2007
Enantioselective Synthesis of 3,4‐Dihydropyran‐2‐ones by Domino Michael Addition and Lactonization with New Asymmetric Organocatalysts: Cinchona‐Alkaloid‐Derived Chiral Quaternary Ammonium Phenoxides
Authors: Tozawa Takashi , Nagao Hitoshi , Yamane Yoshinobu , Mukaiyama Teruaki 
Published: December 2006

AbstractChiral quaternary ammonium phenoxides were readily prepared from commercially available cinchona alkaloids and proved to be useful new asymmetric organocatalysts. Among various chiral quaternary ammonium phenoxides, a cinchonidine‐derived catalyst that bears both a sterically hindered N1‐9‐anthracenylmethyl group and a strongly electron withdrawing 9‐O‐3,5‐bis(trifluoromethyl)benzyl group were found to be highly effective for the Michael addition of ketene silyl acetals (derived from phenyl carboxylates) and α,β‐unsaturated ketones followed by lactonization. Optically active 3,4‐dihydropyran‐2‐one derivatives were obtained in high yields with excellent control of enantio‐ and diastereoselectivity. This catalyst can be handled in air and stored at room temperature in a sealed bottle without decomposition for at least one month.
Neural network prediction of thermophilic (65°C) sulfidogenic fluidized‐bed reactor performance for the treatment of metal‐containing wastewater
Authors: Sahinkaya Erkan , Özkaya Bestamin , Kaksonen Anna H. , Puhakka Jaakko A. 
Published: December 2006

AbstractThe performance of a fluidized‐bed reactor (FBR) based sulfate reducing bioprocess was predicted using artificial neural network (ANN). The FBR was operated at high (65°C) temperature and it was fed with iron (40–90 mg/L) and sulfate (1,000–1,500 mg/L) containing acidic (pH = 3.5–6) synthetic wastewater. Ethanol was supplemented as carbon and electron source for sulfate reducing bacteria (SRB). The wastewater pH of 4.3–4.4 was neutralized by the alkalinity produced in acetate oxidation and the average effluent pH was 7.8 ± 0.8. The oxidation of acetate is the rate‐limiting step in the sulfidogenic ethanol oxidation by thermophilic SRB, which resulted in acetate accumulation. Sulfate reduction and acetate oxidation rates showed variation depending on the operational conditions with the maximum rates of 1 g/L/d (0.2 g/g volatile solids (VS)/d) and 0.3 g/L/d (0.06 g/g VS/d), respectively. This study presents an ANN model predicting the performance of the reactor and determining the optimal architecture of this model; such as best back‐propagation (BP) algorithm and neuron numbers. The Levenberg–Marquardt algorithm was selected as the best of 12 BP algorithms and optimal neuron number was determined as 20. The developed ANN model predicted acetate (R = 0.91), sulfate (R = 0.95), sulfide (R = 0.97), and alkalinity (R = 0.94) in the FBR effluent. Hence, the ANN based model can be used to predict the FBR performance, to control the operational conditions for improved process performance. Biotechnol. Bioeng. 2007;97: 780–787. © 2006 Wiley Periodicals, Inc.
Performance of a down‐flow fluidized bed reactor under sulfate reduction conditions using volatile fatty acids as electron donors
Authors: Celis‐García Lourdes B. , Razo‐Flores Elías , Monroy Oscar 
Published: December 2006

AbstractThe use of a down‐flow fluidized bed (DFFB) reactor for the treatment of a sulfate‐rich synthetic wastewater was investigated to obtain insight into the outcome of sulfate reduction in a biofilm attached to a plastic support under a down‐flow regime. Fine low‐density polyethylene particles were used as support for developing a biofilm within the reactor. The reactor treated a volatile fatty acids mixture of acetate or lactate, propionate, and butyrate at different chemical oxygen demand (COD) to sulfate ratios ranging from 1.67 to 0.67 (g/g). Organic loading rate changed from 2.5 to 5 g COD/L · day and sulfate loading rate increased from 1.5 to 7.3 g SO/L · day. At the beginning of continuous operation, methanogenesis was the predominant process; however, after 187 days, sulfate reduction became the main ongoing biological process. After 369 days, a COD removal of 93% and a sulfate removal of 75% were reached. Total sulfide concentrations in the reactor ranged from 105, when the reactor was mainly methanogenic, to around 1,215 mg/L at the end of the experiment. The high sulfide concentrations did not affect the performance of the reactor. Results demonstrated that the configuration of the DFFB reactor was suitable for the anaerobic treatment of sulfate‐rich wastewater. Biotechnol. Bioeng. 2007;97: 771–779. © 2006 Wiley Periodicals, Inc.
Use of a straight, side‐hole delivery sheath for improved delivery of amplatzer ASD occluder
Authors: Kutty Shelby , Asnes Jeremy D. , Srinath Gowdagere , Preminger Tamar J. , Prieto Lourdes R. , Latson Larry A. 
Published: December 2006

AbstractThe Amplatzer ASD occluder may be difficult to position in some patients with a large atrial septal defect (ASD) or deficiency of one or more atrial septal rims. We developed a method to modify a Mullins transseptal sheath to enhance delivery. The resulting sheath is straight and has an exit orifice essential in the side of the distal portion of the sheath‐a straight, side‐hole (SSH) delivery sheath. We have used this modified delivery sheath in 140 successive patients with excellent results. The techniques of sheath modification and delivery of the device using the modified sheath are described. © 2006 Wiley‐Liss, Inc.
Oxidativer Abbau von C1‐C3‐Carbonsäuren an einem technischen VOx‐TiO2‐Katalysator
Authors: Suprun W. , Kießling D. , Machold T. , Papp H. 
Published: December 2006

AbstractDer oxidative Abbau von Ameisen‐, Essig‐ und Propionsäure wurde an einem VOx‐TiO2‐Katalysator in An‐ und Abwesenheit von Wasser im Bereich von 120 – 280 °C untersucht. Essigsäure ist die gegenüber dem oxidativen Abbau stabilste Carbonsäure. Reaktionsprodukte waren die C‐Zahl niedrigeren Carbonsäuren, COx und Wasser sowie Ethylen im Fall von Propionsäure. Wasser im Eduktgasstrom führte zur Blockierung katalytisch aktiver Zentren und somit zur Verringerung des Umsatzes sowie zur Selektivitätserhöhung der niedrigeren Carbonsäuren. Die Ergebnisse können für die Produktsteuerung bei katalytischen Selektivoxidationen und der oxidativen Dehydrierung niederer Kohlenwasserstoffe genutzt werden.
Plasma Deposition of Thiophene Derivatives Under Atmospheric Pressure
Authors: Dams R. , Vangeneugden D. , Vanderzande D. 
Published: December 2006

AbstractPlasma deposition of conjugated polymer films under atmospheric pressure is described. Three thiophene derivatives (thiophene, 3‐methylthiophene, and 3,4‐ethylenedioxythiophene) are used as monomers. The plasma depositions with the various precursors are compared using analytical techniques such as X‐ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, UV‐vis spectroscopy, and resistance measurements. Good results are obtained with pulsed plasma depositions of poly(3,4‐ethylenedioxythiophene). Conductivities of up to 1 × 10—2 S cm–1 are measured.
Effects of Processing Parameters in the MOCVD Growth of Nanostructured Lanthanum Trifluoride and Oxyfluoride Thin Films
Authors: Malandrino G. , Perdicaro L. M. S. , Fragalà I. L. 
Published: December 2006

AbstractUsing metal–organic (MO)CVD, lanthanum trifluoride (LaF3) and oxyfluoride (LaOF) films are deposited on Si(100), glass, and quartz from a La(hfa)3diglyme single‐source precursor. The films are characterized using X‐ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). They are found to be crystalline with a high degree of fiber texture even when deposited on glass or quartz substrates. The SEM indicates very homogeneous surfaces with grain dimensions decreasing upon increasing the deposition temperature and the oxygen flow. The AFM data indicate a very smooth surface with a root mean square (rms) roughness of 0.96 nm for films deposited at high temperature/high oxygen flow.
Ferroelectric Poly(vinylidene fluoride) Thin Films Grown by Low‐Pressure Chemical Vapor Polymerization
Authors: Rastogi A. C. , Desu S. B. 
Published: December 2006

AbstractFerroelectric poly(vinylidene fluoride) polymer (VDF2)n thin‐film formation by a low‐pressure chemical vapor polymerization (CVP) process is described. The process involves polymerization of an isotropic vinylidene fluoride monomer condensate layer by cleavage of C double bonds using :CF2 initiators derived from hot‐filament, thermochemical decomposition of the hexafluoropropylene oxide C3F6O. Two different growth modes on the film surface and in the bulk are identified by Fourier transform infrared (FTIR) and X‐ray photoelectron spectroscopy (XPS) studies. Surface impingement of :CF2 induces lateral growth of molecular chains in trans conformation. Due to the initiation of polymerization at random surface sites, amorphous β‐phase growth is also observed. Bulk growth of polymer film involves chain formation dominated by gauche conformations having a predominance of the α‐phase. Ferroelectric investigations of (VDF2)n films show spontaneous polarization and hysteresis effects, which improves on crystallization. Typical polarization values of 3.5 and 1.5 μC cm–2 in the planar and normal directions, respectively, are observed after crystallization. Structural defects in the molecular chains give rise to space charge conduction which affects polarization switching properties. The low‐pressure CVP technique is compatible with sub‐micrometer semiconductor device fabrication and also provides a novel method for incorporating additional functional units into the molecular chains to control the film properties.
Vanin‐1 controls granuloma formation and macrophage polarization in Coxiella burnetii infection
Authors: Meghari Soraya , Berruyer Carole , Lepidi Hubert , Galland Franck , Naquet Philippe , Mege Jean‐Louis 
Published: December 2006

AbstractQ fever is caused by Coxiella burnetii, a bacterium that survives in MΦ. Vanin‐1 is a membrane‐anchored pantetheinase that controls tissue inflammation. Consequently, Vanin‐1‐deficient mice represent a unique mouse model in which stress‐induced inflammation is limited by the reaction of resident tissue cells. To investigate the contribution of host tissues in the control of a bacterial infection, we infected Vanin‐1‐deficient mice with C. burnetii. Mortality and morbidity of mice were not affected. The lack of Vanin‐1 had no effect on C. burnetii clearance but decreased the formation of granulomas in spleen and liver. Granuloma formation depends upon MΦ recruitment and activation in these tissues. Whereas the former was slightly impaired in mutant mice, the lack of Vanin‐1 significantly affected the activation pattern of BM‐derived MΦ stimulated by C. burnetii. While their microbicidal activity against C. burnetii was moderately impaired, they exhibited decreased inducible nitric oxide synthase (iNOS) and MCP‐1 gene expression, and increased IL‐10 and arginase expression. In liver from mutant mice, increased arginase expression and decreased expression of MCP‐1 and iNOS were reminiscent of MΦ data. These results suggest a role of Vanin‐1 in granuloma formation in response to C. burnetii by skewing MΦ activation toward an M2 program.See accompanying commentary http://dx.doi.org/10.1002/eji.200636910
Genetic analysis of the innate immune responses in wild‐derived inbred strains of mice
Authors: Stephan Kristin , Smirnova Irina , Jacque Berri , Poltorak Alexander 
Published: December 2006

AbstractThe vertebrate immune system has evolved to recognize nucleic acids of bacterial and viral origin. Microbial DNA, as well as synthetic oligonucleotides based on these motifs, activates innate immune pathways mediated by the family of Toll‐like receptors (TLR) initiating a cascade of signals in immune cells necessary for responses to pathogens. However, not all of the proteins that participate in TLR‐mediated responses have been identified. In studies described herein, we observed significant variation in innate immune responses among selected wild‐derived strains of mice. Specifically, we show that mice of MOLF/Ei, Czech/Ei, and MSM/Ms strains are hypo‐responsive to polyinosinic‐polycytidylic acid (poly(I:C)) because of a mutation in Tlr3. In addition, we discovered a hypo‐response to cytosine guanine dinuleotide in MOLF/Ei mice and established that it is not linked to Tlr9, but to another locus. Further inquiry revealed that this hypo‐response is transmitted as a monogenic dominant trait that can be mapped and cloned through positional cloning methods. These results suggest the existence of a novel molecule that can alter pro‐inflammatory signals or activate additional signal transduction pathways. In addition, they support the wild‐derived mouse strain as a forward genetic tool for the identification of novel immunological phenotypes.
Dynamics and magnitude of virus‐induced polyclonal B cell activation mediated by BCR‐independent presentation of viral antigen
Authors: Jellison Evan R. , Guay Heath M. , Szomolanyi‐Tsuda Eva , Welsh Raymond M. 
Published: December 2006

AbstractHypergammaglobulinemia and production of autoantibodies occur during many viral infections, and studies have suggested that viral antigen‐presenting B cells may become polyclonally activated by CD4 T cells in vivo in the absence of viral engagement of the BCR. However, we have reported that CD4 cells in lymphocytic choriomengitis virus (LCMV)‐infected mice kill adoptively transferred B cells coated with LCMV class II peptides. We report here that most of the surviving naïve B cells presenting class II MHC peptides undergo an extensive differentiation process involving both proliferation and secretion of antibodies. Both events require CD4 cells and CD40/CD40L interactions but not MyD88‐dependent signaling within the B cells. B cells taken from immunologically tolerant donor LCMV‐carrier mice with high LCMV antigen load became activated following adoptive transfer into LCMV‐infected hosts, suggesting that B cells present sufficient antigen for this process during a viral infection. No division or activation of B cells was detected at all in virus‐infected hosts in the absence of cognate CD4 T cells and class II antigen. This approach, therefore, formally demonstrates and quantifies a virus‐induced polyclonal proliferation and differentiation of B cells, which, due to their high proportion, would mostly have BCR not specific for the virus.
The Ig‐α ITAM is required for efficient differentiation but not proliferation of pre‐B cells
Authors: Storch Bettina , Meixlsperger Sonja , Jumaa Hassan 
Published: December 2006

AbstractSignals from the pre‐B cell receptor (pre‐BCR) mediated by the cytoplasmic tails of Ig‐α/Ig‐β are essential for developing B cells. To analyze the role of Ig‐α ITAM and non‐ITAM tyrosines in pre‐BCR signaling, we reconstituted individual tyrosine mutants of Ig‐α in src homology 2 domain‐containing leukocyte protein of 65 kDa (SLP‐65)/Ig‐α double‐deficient pre‐B cells. We show that the Ig‐α mutants led to comparable pre‐BCR expression on the cell surface, while the pre‐BCR‐induced tyrosine phosphorylation was different. We further show that the reconstitution of Ig‐α and the resulting pre‐BCR expression led to enrichment of the pre‐BCR‐expressing cells in vitro irrespective of the introduced Ig‐α mutation. We show that, even though the enrichment rate increased by lowering the IL‐7 concentration, residual amounts of IL‐7 were required for optimal enrichment. Our results indicate that surface IL‐7 receptor expression is modulated by the pre‐BCR, thereby increasing the IL‐7 sensitivity of the respective cells. In contrast to the comparable pre‐B cell proliferation, however, the Ig‐α mutants differed in their capacity to induce calcium flux and activate efficient pre‐B cell differentiation. Together, our data suggest that ITAM tyrosines and Y204 are required for efficient pre‐B cell differentiation but not proliferation.Supporting information for this article is available at http://www.wiley‐vch.de/contents/jc_2040/2007/36667_s.pdf
Formation of a Ruthenium μ‐Carbide Complex with Acetylene as the Carbon Source
Authors: Solari Euro , Antonijevic Sasa , Gauthier Sébastien , Scopelliti Rosario , Severin Kay 
Published: December 2006

AbstractReactions of the dinuclear ruthenium complex [(p‐cymene)Ru(μ‐Cl)3RuCl(C2H4)(PCy3)] with phenylacetylene or tert‐butylacetylene gave the vinylidene complexes [(p‐cymene)Ru(μ‐Cl)3RuCl(=C=CHR)(PCy3)] (R = tBu, Ph), which were characterized crystallographically. With acetylene, however, a tetranuclear μ‐carbide complex was obtained as evidenced by single‐crystal X‐ray analysis as well as by solid‐state NMR spectroscopy. Experiments with fully 13C‐labelled acetylene showed that acetylene was the carbon source for the carbide ligand. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Novel Synthetic Cycloketo‐Tetraphenylporphyrins
Authors: Jasinski Stefan , Ermilov Eugeny A. , Jux Norbert , Röder Beate 
Published: December 2006

AbstractNew tetraphenylporphyrins 2a and 2b have been synthesized and characterized. Both compounds possess an ethanone bridge that connects the porphyrin ring with one of the phenyl groups at the periphery. Tetraphenylporphyrin 2a also has a methyl group on the same phenyl ring, whereas tetraphenylporphyrin 2b lacks this substituent. This small difference results in 2a and 2b having markedly different photophysical properties. In particular, 2a proved to be a highly efficient sensitizer for singlet oxygen generation with a quantum yield of 0.85. A reference compound 2c has also been synthesized in which the porphyrin ring is connected to one of the peripheral phenyl groups through just a keto function. Thus, the effect of the size of the exocyclic ring on conjugation and photophysical properties has been studied. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Active Site Protonation of 1‐Azafagomine in Glucosidases Studied by Solid‐State NMR Spectroscopy
Authors: Sivertsen Astrid C. , Gasior Magdalena , Bjerring Morten , Hansen Steen U. , Lopez Lopez Oscar , Nielsen Niels C. , Bols Mikael 
Published: December 2006

AbstractProtonation of an azasugar inhibitor inside the active site of a glycosidase has been studied by solid‐state NMR spectroscopy. By measuring 13C chemical shifts of azafagomine bound to yeast α‐glucosidase, almond β‐glucosidase, andAspergillus niger glucoamylase, and 15N chemical shift ofazafagomine bound to β‐glucosidase, we find evidence for an N1‐protonation of azafagomine inside β‐glucosidase. For α‐glucosidase and glucoamylase the corresponding chemical shifts are similar to those of the non‐protonated inhibitor, which shows that charge stabilization at anomeric position is not occurring in these enzymes.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Seismic control of smart base isolated buildings with new semiactive variable damper
Authors: Nagarajaiah S. , Narasimhan S. 
Published: December 2006

AbstractA new semiactive independently variable damper, SAIVD, is developed and shown to be effective in achieving response reductions in smart base isolated buildings in near fault earthquakes. The semiactive device consists of four linear visco‐elastic elements, commonly known as Kelvin–Voigt elements, arranged in a rhombus configuration. The magnitude of force in the semiactive device can be adjusted smoothly in real‐time by varying the angle of the visco‐elastic elements of the device or the aspect ratio of the rhombus configuration. Such a device is essentially linear, simple to construct, and does not present the difficulties commonly associated with modelling and analysing nonlinear devices (e.g. friction devices). The smooth semiactive force variation eliminates the disadvantages associated with rapid switching devices. Experimental results are presented to verify the proposed analytical model of the device. A H∞ control algorithm is implemented in order to reduce the response of base isolated buildings with variable damping semiactive control systems in near fault earthquakes. The central idea of the control algorithm is to design a H∞ controller for the structural system that serves as an aid in the determination of the optimum control force in the semiactive device. The relative performance of the SAIVD device is compared to a variable friction device, recently developed by the authors in a separate study, and several key aspects of performance are discussed regarding the use of the two devices for reducing the responses of smart base isolated buildings in near fault earthquakes. Copyright © 2006 John Wiley & Sons, Ltd.
Plant communities of the Mongolian Transaltay Gobi
Authors: von Wehrden H. , Hilbig W. , Wesche K. 
Published: December 2006

AbstractHere we present the first detailed phytosociological description of the plant communities of the Transaltay Gobi, the driest region within Outer Mongolia. It was originally gazetted as a national park by the Mongolian parliament in 1976, which included also the Dzungarian basin in south‐western Mongolia. The status of the Great Gobi A National Park in the Transaltay Gobi, and the Great Gobi B National Park in the Dzungarian Gobi was later raised to the level of Strictly Protected Area. Since the area hosts many endangered wildlife species, we offer an initial vegetation description, which is necessary to understand the habitats of this arid ecosystem. Based on a modified Braun‐Blanquet approach we designated eight zonal vegetation units, most of which are impoverished regional variants of vegetation types previously described from adjacent regions; most units contain several sub‐units. The altitudinal gradient reflects the climatic regime in the study area; therefore the vegetation distribution follows the precipitation gradient regarding both vegetation cover and diversity. The most important diagnostic species are typical drought–adapted central Asian ele‐ments, namelyHaloxylon ammodendron, Ephedra przewalskii, Reaumuria songaricaandAnabasis brevifolia. Three new associations were designated based on our vegetation data.The main determinant for the riparian vegetation types is apparently groundwater availability, leading to locally high soil salt contents due to the high evaporation in the region. Poplar stands, reed beds andTamarixstands are the characteristic vegetation types of the oases in the working area. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)