bluuebunny/crossref_metadata_2025_split huggingface dataset:
Silica‐Supported Zirconium Complexes and their Polyoligosilsesquioxane Analogues in the Transesterification of Acrylates: Part 1. Synthesis and Characterization
Authors: Salinier Valérie , Corker J. M. , Lefebvre Frédéric , Bayard François , Dufaud Véronique , Basset Jean‐Marie 
Published: September 2009

AbstractVarious silica‐supported acetylacetonate and alkoxy zirconium(IV) complexes have been prepared and characterized by quantitative chemical measurements of the surface reaction products, quantitative surface microanalysis of the surface complexes, in situ infrared spectroscopy, CP‐MAS 13C NMR spectroscopy and EXAFS. The complex (SiO)Zr(acac)3 (acac=acetylacetonate ligand) (1) can be obtained by reaction of zirconium tetraacetylacetonate [Zr(acac)4] with a silica surface previously dehydroxylated at 500 °C. The complexes (SiO)3Zr(acac) (2) and (SiO)3Zr(O‐n‐Bu) (n‐Bu=butyl ligand) (3) can be synthesized by reaction of (SiO)3ZrH with, respectively, acetylacetone and n‐butanol at room temperature. The spectroscopic data, including EXAFS spectroscopy, confirm that in compound 1 the zirconium is linked to the surface by only one SiOZr bond whereas in the case of compounds 2 and 3 the zirconium is linked to 3 surface oxygen atoms which are sigma bonded. EXAFS data indicate also that the acetylacetonate ligands behave as chelating ligands leading to a hepta‐coordination around the zirconium atom in 1 and a penta‐coordination in 2. In order to provide a molecular analogue of 1, the synthesis of the following polyoligosilsesquioxane derivative (c‐C5H9)7Si8O12(CH3)2Zr(acac)3 (1′) was achieved. The compound 1′ is obtained by reacting (c‐C5H9)7Si8O11(CH3)2(OH), 4, with an equimolecular amount of Zr(acac)4. In the same manner, syntheses of complexes (c‐C5H9)7Si7O12Zr(acac) (2′) and of (c‐C5H9)7Si7O12Zr(O‐n‐Bu) (3′) were achieved by reaction of the unmodified trisilanol, (c‐C5H9)7Si7O9(OH)3, with respectively Zr(acac)4 and Zr(O‐n‐Bu)4 at 60 °C in tetrahydrofuran. Compounds 1′, 2′ and 3′ can be considered as good models of 1, 2 and 3 since their spectroscopic properties are comparable with those of the surface complexes. The synthetic results obtained will permit us to study the catalytic properties of these surface complexes and of their molecular analogues with the ultimate goal of delineating clear structure‐activity relationships.
Development of Molecular Sieves‐Supported Palladium Catalyst and Chemoselective Hydrogenation of Unsaturated Bonds in the Presence of Nitro Groups
Authors: Maegawa Tomohiro , Takahashi Tohru , Yoshimura Masatoshi , Suzuka Hiroyasu , Monguchi Yasunari , Sajiki Hironao 
Published: September 2009

AbstractThe chemoselective hydrogenation of unsaturated bonds and azide functionalities is achieved in the presence of nitro groups by a heterogeneous palladium catalyst supported on molecular sieves (MS3A). The present method shows a wide‐range of applicability with regard to substrates and the catalyst can be easily prepared and reused at least three times without any loss of activity.
Doubly Stereocontrolled Asymmetric Aza‐Henry Reaction with in situ Generation of N‐Boc‐Imines Catalyzed by Novel Rosin‐Derived Amine Thiourea Catalysts
Authors: Jiang Xianxing , Zhang Yifu , Wu Lipeng , Zhang Gen , Liu Xing , Zhang Hailong , Fu Dan , Wang Rui 
Published: September 2009

AbstractThe doubly stereocontrolled organocatalytic aza‐Henry reaction of nitroalkanes to N‐Boc‐imines generated in situ from a variety of substituted α‐amido sulfones was investigated for the first time, in general, affording the corresponding products with high to excellent yields (up to 93% yield) and enantioselectivities (up to 98% ee), and satisfactory diastereoselectivies (anti/syn up to 98:2). Furthermore, these organocatalysts based on rosin have been proved to be the very effective promoters for this catalytic asymmetric process along side the Cinchona alkaloid‐derived catalysts.
The ischial callosities of Sulawesi macaques
Authors: Juliandi Berry , Suryobroto Bambang , Perwitasari‐Farajallah Dyah 
Published: September 2009

AbstractSulawesi island has a high level of endemism, including the seven species of monkey from the genus Macaca (macaques). These monkeys have a pair of sitting pads, termed ischial callosities that have diverse shapes and previously were described verbally only. Although useful, these verbal descriptions cannot fully describe shape variation and are somewhat subjective, and cannot directly be used to analyze relationships among species. Here, we report a quantitative analysis of shape of Sulawesi macaque ischial callosities using geometric morphometric tools to optimally describe shape variation and objectively reconstruct general pattern of callosity shapes. By quantification of shape variation, we compare the relationships of each Sulawesi macaque species with each other and with the two geographically neighboring macaque species, M. nemestrina and M. fascicularis, by consensus coordinates of the callosity outlines. The Sulawesi macaques have a wider degree of variation compared with M. fascicularis and M. nemestrina; variation exists in the dorsal part and in the bending of the callosity. There are three general types of callosity shape in Sulawesi macaques: oval without bending (M. tonkeana and M. maurus), oval with outward bending (M. ochreata and M. brunnescens), and oval or reniform with inward bending (M. hecki, M. nigrescens, and M. nigra). These types are congruent with their geographical distribution. The pathway of shape change may have started from oval without bending in the center and the southern peninsula, to outward bending in the southeastern species, and to oval or reniform with inward bending in the northern species. Am. J. Primatol. 71:1021–1031, 2009. © 2009 Wiley‐Liss, Inc.
Membrane bioreactors for regenerative medicine: an example of the bioartificial liver
Authors: Morelli Sabrina , Salerno Simona , Piscioneri Antonella , Campana Carla , Drioli Enrico , Bartolo Loredana De 
Published: September 2009

AbstractLiver transplantation is the only established treatment for liver failure. Because of the organ scarsity, liver support strategies are being developed with the aim of either supporting patients with the borderline functional liver cell mass until the organ transplantation or liver regeneration. A bioartificial liver (BAL) consisting of functional liver cells supported by an artificial cell culture material could provide a vital temporary support to patients with liver failure, and could serve as a bridge to transplantation while awaiting a suitable donor. In this paper, we discuss the critical issues for the development of BAL such as bioreactor configuration, mass transfer, cell source and culture technique. The characteristics of membrane BAL systems in clinical, preclinical and in vitro tests are reviewed. Membrane bioreactors used for the generation of in vitro physiological model systems for studying biological mechanisms and testing the efficacy of potential therapies are also discussed. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Remarks on studies for direct production of phenol in conventional and membrane reactors
Authors: Molinari Raffaele , Poerio Teresa 
Published: September 2009

AbstractThe great interest in the oxidation reaction of benzene to phenol is linked to some disadvantages of the cumene process, such as environmental impact, production of an explosive intermediate, a multi‐step process (which involves (1) difficulty to achieve high phenol yield, in relation to the benzene used and (2) high capital investment), and a high acetone production as a co‐product which results in an over supply in the market.In this paper, we discuss various studies concerning a new approach based on a one‐step and acetone‐free method for phenol production. Particular attention is devoted to phenol production processes using various configurations of membrane reactors (MRs) and a photocatalytic membrane reactor (PMR). In particular, the biphasic MR allowed to achieving high selectivity values (97–98%).The described studies have been classified according to oxidant type such as N2O, O2, and H2O2. Each of them shows that direct oxidation of benzene to phenol is a difficult task and further efforts are needed to search and replace the three step traditional process of converting benzene into phenol with a process of direct oxidation. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
A simplified method for limit conversion calculation in membrane reactors
Authors: Gallucci Fausto , De Falco Marcello , Basile Angelo 
Published: September 2009

AbstractMembrane reactors (MRs) are often used to carry out equilibrium limited reactions. This is because the thermodynamic equilibrium is a strong constrain for traditional systems. Even with very active catalysts, traditional reactors (TRs) cannot give conversions higher than those allowed by the thermodynamic equilibrium. On the contrary, MRs are able to shift the equilibrium of a traditional system owing to the removal of at least one reaction product that takes place simultaneously to the reaction. In this work, a simplified method for the calculation of limit conversion in MR is discussed and compared with literature methods. The typical method for calculating equilibrium conversions in TR is also discussed. It has been demonstrated that the simplified method applied to two reaction systems gives fast predictions of the limit conversion for MR. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Syntheses of esters through poly(styrene sulfonic acid)/poly(vinyl alcohol) membrane reactor
Authors: Uragami Tadashi , Nishikawa Masanaga 
Published: September 2009

AbstractCation exchange membranes prepared from poly(styrene sulfonic acid) (PSA) and poly(vinyl alcohol) (PVA) were cross‐linked by both glyoxal and gultaraledehyde and cross‐linked membranes furthermore were annealed. The ion exchange capacity of the resulting PSA/PVA membranes increased, and the water content and degree of swelling of PSA/PVA membrane decreased with increasing annealing time. The syntheses of esters from alcohol and acetic acid through various PSA/PVA membranes have been carried out in a diaphragm type cell consisting of two detachable parts in which the membrane was set in the middle of the two parts of cell. When an aqueous solution of alcohol and acetic acid on one part of cell and p‐chloro benzene (Cl‐Bz) on another part were set, esters formed by the catalytic action of PSA/PVA membrane increased on the Cl‐Bz phase with time. These results support that the PSA/PVA membrane could perform both the reaction and separation. The formation of esters in this membrane reactor was a secondary reaction as well as general the esterification between alcohols and acids. The catalytic action in the esterification of the PSA/PVA membranes prepared by changing the ratio of PSA/PVA and the amount of casting solution was also investigated. The rate of esterification reaction was significantly dependent on the number of sulfonic acid group in the effective membrane volume. The rate of reaction per mEq SO3H increased with an increase of the degree of swelling of the membrane and decreasing membrane thickness. In the esterifications of methanol, ethanol and n‐propanol with acetic acid, the reactivity through the PSA/PVA membrane was higher than that with HCl as catalyst. In that of n‐butanol with acetic acid, however, it was vice versa. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Chemical cleaning of reverse osmosis membrane fouled by sugar solution
Authors: Madaeni S. S. , Sasanihoma A. , Zereshki S. 
Published: September 2009

AbstractMembrane fouling is a complex phenomenon and typically results from several reasons. Chemical cleaning is a strategy for regeneration of the fouled membranes. In this work, BW30 reverse osmosis membranes were fouled with sugar solution. The effect of different cleaning agents on the revival of the fouled membrane was studied. The role of chemical and physical interactions on chemical cleaning of organic‐fouled RO membranes using a wide variety of cleaning agents including acids (HCl and HNO3), bases (NH3 and NaOH), complexing agents [ethylene diamine tetra acetic acid (EDTA)], surfactants [cetyle three methyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS)], and water have been systematically investigated. Resistance removal (RR) and flux recovery (FR) were used for demonstration of the cleaning efficiency. Membrane fouling is customarily indicated and measured by permeate decline at constant operating conditions. It has been shown that the cleaning efficiency changes with increasing the concentration of the cleaning agent. NH3 was the best cleaning agent for removing sucrose from membrane surface. EDTA and SDS were quite effective in reacting with organic foulants in the fouling layer. Moreover, pure water was used as cleaning agent with acceptable results. Water is safe, cheap, and broadly available in most plants and could be considered as a good recommendation. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Effects of recycled fiber addition on high‐density fiberboard for laminated flooring bonded with phenol‐formaldehyde resin adhesive
Authors: Oh Yong‐Sung 
Published: September 2009

AbstractThe effects of old corrugated cardboard (OCC) fiber addition on high‐density fiberboard (HDF) were investigated in this study. A phenol‐formaldehyde (PF) resin was synthesized in the laboratory with resin solids at 50% content as an HDF binder. The physical characteristics and molecular weight of the PF resin are described herein. The laboratory HDFs were made using the OCC fiber based on 0, 20, 40, and 60% oven‐dry weight addition with the laboratory‐synthesized PF resin. The HDFs were tested for physical strength and dimensional stability properties according to the procedure of ASTM D 1037‐99. Evaluation of the HDFs manufactured using the PF resin showed that the internal bond and bending strength properties were decreased gradually with increasing OCC fiber content. Overall, the OCC fiber can be used at a content of 40% in the substitution of raw materials for HDF manufacture. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Investigation of water vapor permeability and antimicrobial property of zinc oxide nanoparticles‐loaded chitosan‐based edible film
Authors: Bajpai S. K. , Chand Navin , Chaurasia Varsha 
Published: September 2009

AbstractThis study is focused on the investigation of moisture uptake properties of chitosan films. The GAB isotherm model is found to fit well to the experimental moisture uptake data obtained at 10, 25, and 37°C. The water vapor permeability is found to increase with temperature. The use of plasticizer enhances the water vapor permeability. Finally, the films have been loaded with ZnO nanoparticles and characterized by X‐ray diffraction, differential scanning calorimetry, surface plasma resonance, and scanning electron microscopic analyses. The crystal size as determined using Scherrer's equation is found to be around 15 nm. The films have shown excellent antibacterial action against the model bacteriumEscherichia coli. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Recent progress in the preparation, characterization, and applications of nanofibers and nanofiber membranes via electrospinning/interfacial polymerization
Authors: Feng C. , Khulbe K. C. , Matsuura T. 
Published: September 2009

AbstractSignificant progress has been made recently in the fabrication of polymeric nanofibers, their characterization and applications, new polymeric materials, theoretical analysis, and so forth. Hence, in this brief review, we report the progress made in these subjects during the last 5 years. Most of the work concerns nanofibers related to the field of medicine. On the other hand, negligibly few reports have been found on nanofibers related to membrane separation processes. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation and electrical characterization of poly(vinyl amine) hydrogels, crosslinked with Cu(II) ions, and evaluation of their potentiality as water sensor material
Authors: Mendoza‐Payan Jesus G. , Flores‐Gallardo Sergio , Marquez‐Lucero Alfredo 
Published: September 2009

AbstractA method to prepare water sensitive composites employing crosslinked poly(vinyl amine) (PVAm) and Cu(II) ions as reticulation agent is disclosed in this work. This article presents in detail, the reticulation reaction and its pH dependence, as well as its electrical, rheological, and thermal properties of the PVAm‐Cu(II) composites obtained. The complex bonds formed between the Cu(II) ions and the amine groups of PVAm produce an interesting network of crosslinked structures that generate a microporous morphology when the material is extruded. This characteristic favors fast absorption of water when it is wetted, and a concomitant decrease in its apparent resistivity in a very short period of time. Furthermore, they present an excellent thermal stability and suitable processability. These characteristics make them interesting candidates to design ultra fast water sensors. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Degradation of biomedical polydimethylsiloxanes during exposure to in vivo biofilm environment monitored by FE‐SEM, ATR‐FTIR, and MALDI‐TOF MS
Authors: Kaali Peter , Momcilovic Dane , Markström Agneta , Aune Ragnhild , Czel Gyorgy , Karlsson Sigbritt 
Published: September 2009

AbstractPolymers used for biomedical purposes in medical devices are usually requested to be inert to degradation. This article describes that slow irreversible changes were observed in silicone surfaces exposed to in vivo biofilms even if silicone, in general, is supposed to have excellent long‐term properties. Tracheostomy tubes made of silicone rubber were exposed to in vivo biofilm environments in clinical tests for periods of 1, 3, and 6 months. The chemical degradation was monitored by MALDI‐TOF MS, ATR‐FTIR, and FE‐SEM. In addition, the physical changes were monitored by contact angle and hardness measurements. Cyclic polydimethylsiloxane (PDMS) was detected on the surfaces of new (unaged) silicones. On the surfaces of the in vivo samples new compounds, presumably linear methyl‐hydroxyl‐terminated PDMS, were detected in addition to cyclic PDMS. These compounds may be formed as a result of the hydrolysis of linear dimethyl terminated PDMS, which is also present in the silicone rubber. ATR‐FTIR spectroscopy confirmed that hydrolysis had indeed occurred during the in vivo exposure, since SiOH groups were detected. Furthermore, significant changes in the topography were detected by FE‐SEM, indicating the initiation of degradation. No significant changes in the contact angle of the in vivo used samples were observed, but this information may be shielded by the fact that biofilm may remain on the surface, despite the thorough cleaning before the analysis. It is also possible that the surface hydrophobicity was recovered by the diffusion of linear low‐molecular‐weight compounds from the bulk. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Formulation and release of doxycycline HCL from an ion activated in situ gelling delivery system for the treatment of periodontal disease
Authors: Obaidat Aiman A. , Altamimi Riham M. , Hammad Mohammad M. 
Published: September 2009

AbstractThis study reports on the formulation of doxycycline HCL in an ion activated in situ gelling delivery system and its implications for the treatment of periodontal disease. The system is based on the use of alginate as the gelling agent and hydroxypropyl methylcellulose (HPMC) as a viscosity enhancing agent. The ion activated gelling mechanism in this system is based on the concept of interaction with the divalent calcium ions present in the gingival crevicular fluid (GCF). The gelling capacity of the prepared formulations was assessed visually and by investigating their rheological behavior upon mixing with human blood serum since it has the same composition as the GCF. The rheological behavior of all formulations was not affected by incorporation of the drug. In vitro release studies showed that the alginate/HPMC mixture, upon gelling after mixing with serum, can sustain the release of doxycycline HCL for an extended period of time which was more than 12 days. These results indicated that this system can be used as an in situ gelling local delivery system for the treatment of periodontal disease. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
High dose methotrexate population pharmacokinetics and Bayesian estimation in patients with lymphoid malignancy
Authors: Min Ye , Qiang Fu , Peng Li , Zhu Zhu 
Published: September 2009

AbstractThe purpose of present study was to develop a population pharmacokinetic model of high dose methotrexate (HD‐MTX) infusion in patients with lymphoid malignancy, to investigate the biological and clinical covariates related to the drug distribution and elimination. It is also the purpose to propose a limited sampling strategy (LSS) for the estimation of the time above the threshold (0.2 µmol·L−1). A total 82 patients with lymphoid malignancy were involved in the study. A pharmacokinetic model was developed using nonlinear mixed‐effect model. The influence of demographic characteristics, biological factors, and concurrent administration were investigated. The final predictive performance was validated by bootstrap and cross‐validation. Bayesian estimation was evaluated. The pharmacokinetics of HD‐MTX was described by a two‐compartment model. The pharmacokinetic parameters and the inter‐individual variability were as follows: the clearance CL, 7.45 L·h−1 (inter‐individual variability 50.6%), the volume of the central and peripheral compartment V1, 25.9 L (22.5%), V2, 9.23 L (97.8%), respectively, and the intercompartmental clearance Q, 0.333 L·h−1 (70.4%). The influence of serum creatinine on CL and weight on V1 was retained in the final model. The protocol involved one sampling time at 44 h after the start of the infusion, allowing one to predict the time at which the MTX concentration reached the expected threshold (0.2 µmol·L−1). Serum creatinine and weight showed significant influence on methotrexate CL and V1, respectively. Furthermore, a Bayesian estimation based on the covariates and 44 h sample was developed, allowing prediction of the individual methotrexate pharmacokinetic parameters and the time to 0.2 µmol·L−1. Copyright © 2009 John Wiley & Sons, Ltd.
Sensitive determination of gentiopicroside in medicine and bio‐fluids using luminol‐myoglobin chemiluminescence combined with flow injection technique
Authors: He Xili , Xie Xiaofeng , Shao Xiaodong , Song Zhenghua 
Published: September 2009

AbstractA novel chemiluminescence method for the determination of gentiopicroside is presented, which was based on the inhibitory effect of gentiopicroside on the chemiluminescence reaction between luminol and myoglobin in a flow‐injection system. The decrement of chemiluminescence intensity was linear with the logarithm of gentiopicroside concentration over the range from 10.0 pg mL−1 to 500.0 ng mL−1 (r2 = 0.9992), with a detection limit of 3.0 pg mL−1 (3σ). At a flow rate of 2.0 mL min−1, a complete analytical process could be performed within 0.5 min, including sampling and washing, with a relative standard deviation of less than 3.0% (n = 5). The proposed procedure was applied successfully in the determination of gentiopicroside in pharmaceutical preparations, human urine and serum without any pretreatment procedure. The possible mechanism of the reaction was also discussed. Copyright © 2009 John Wiley & Sons, Ltd.