bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interaction of polydiallyldimethylammonium salts with iodine
Authors: Bendoraitiene Joana , Mazoniene Edita , Zemaitaitiene Rima Jule , Zemaitaitis Algirdas 
Published: February 2006

AbstractThe interaction between polydiallyldimethylammonium chloride (PDADMAC) and KI or KBr, followed by changes in conformation of macromolecules, coil compaction, and counterion exchange, was detected by means of turbidimetry and viscometry. In aqueous solutions at presence of KI, PDADMAC rapidly binds iodine by the formation of polymer–iodine complexes PDADMA I− Im (m ≤ 4). Spectrophotometric investigations of the interaction in water without KI prove the formation of complexes of polyquaternary ammonium chloride or bromide with iodine only via iodide. These ions can be generated in the polymer‐catalyzed hydrolysis reaction of iodine. By inducing hydrolysis of iodine and binding the eventually formed iodide, PDADMAC acts as an iodine acceptor with self‐strengthening capacity. For the sorption of gaseous iodine, the possibility of direct interaction of its dipoles with the charged groups of the polyelectrolyte is also reasoned. Polydiallyldimethylammonium halides were used to modify activated carbon and employed in a nuclear power station for treatment of outlet gases containing radioactive iodine. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2710–2716, 2006
Preparation and characterization of low‐density polyethylene/banana starch films containing compatibilizer and photosensitizer
Authors: Ratanakamnuan Usarat , Aht‐Ong Duangdao 
Published: February 2006

AbstractComposite films containing various percentages of banana starch and low‐density polyethylene (LDPE) were prepared. The effects of the compatibilizer, banana starch content, and photosensitizer content on the thermal and tensile properties of these films were investigated. The banana starch content was varied from 5 to 20 wt % of LDPE, whereas benzophenone was added as a photosensitizer in three different amounts (0.25, 0.5, and 1 wt %) based on LDPE. In these films PE‐graft‐maleic anhydride (PE‐g‐MA) was used as a compatibilizer at 10 wt % banana starch. It was found that the thermal stability of the composite films remained unchanged with respect to the amount of banana starch and benzophenone content. The addition of banana starch had no effect on the melting temperature and degree of crystallinity of the films. Similarly, PE‐g‐MA had no effect on the melting temperature but decreased the degree of crystallinity of the LDPE phase. Benzophenone caused an increase in the melting temperature but decreased the degree of crystallinity of LDPE in the films. Increasing the amount of banana starch decreased the tensile properties of the composite films. The addition of PE‐g‐MA as a compatibilizer increased the tensile properties compared with the uncompatibilized films. However, benzophenone had no effect on the tensile properties of the blend films. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2717–2724, 2006
Photobiodegradation of low‐density polyethylene/banana starch films
Authors: Ratanakamnuan Usarat , Aht‐Ong Duangdao 
Published: February 2006

AbstractThe effects of the starch content, photosensitizer content, and compatibilizer on the photobiodegradability of low‐density polyethylene (LDPE) and banana starch polymer blend films were investigated. The compatibilizer and photosensitizer used in the films were PE‐graft‐maleic anhydride (PE‐g‐MA) and benzophenone, respectively. Dried banana starch at 0–20% (w/w) of LDPE, benzophenone at 0–1% (w/w) of LDPE, and PE‐g‐MA at 10% (w/w) of banana starch were added to LDPE. The photodegradation of the blend films was performed with outdoor exposure. The progress of the photodegradation was followed by determining the carbonyl index derived from Fourier transform IR measurements and the changes in tensile properties. Biodegradation of the blend films was investigated by a soil burial test. The biodegradation process was followed by measuring the changes in the physical appearance, weight loss, and tensile properties of the films. The results showed that both photo‐ and biodegradation rates increased with increasing amounts of banana starch, whereas the tensile properties of the films decreased. The blends with higher amounts of benzophenone showed higher rates of photodegradation, although their biodegradation rates were reduced with an increase in benzophenone content. The addition of PE‐g‐MA into polymer blends led to an increase in the tensile properties whereas the photobiodegradation was slightly decreased compared to the films without PE‐g‐MA. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2725–2736, 2006
Kinetics and simulation of the imidization of poly(styrene‐co‐maleic anhydride) with amines
Authors: Liu He‐Yang , Cao Kun , Huang Yuan , Yao Zhen , Li Bo‐Geng , Hu Guo‐Hua 
Published: February 2006

AbstractThe imidization of poly(styrene‐co‐maleic anhydride) with amines may improve some of its end‐use properties. The objective of this study was to examine the mechanism and kinetics with aniline (ANL) as an amine of the preparation of poly(styrene‐co‐N‐phenyl maleimide). The reaction was carried out in a tetrahydrofuran solution at 25–55°C and in an ethylbenzene solution at 85–120°C. The extent of the reaction was determined by conductance titration, a new and simple method. Two consecutive reactions were involved in the imidization: ring opening to produce an acido‐amide group and ring closing to form a corresponding imide group. The imidization rate was greatly influenced by the reaction temperature and the molar ratio of ANL to the anhydride. A model for the imidization kinetics over a wide range of reaction temperatures and concentration ranges was developed and validated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2744–2749, 2006
Preparation and properties of new polyurethane gels with a stress‐distributing function for medical applications
Authors: Cha Gook Chan , Lee Sukmin , Song Jeom Sik , Kim Jong Kwon , Kim Kyung Hoon , Mun Mu Seong , Youn Hyoung Soon , Pyun Do Gi , Choi Yoon So 
Published: February 2006

AbstractThe purpose of this study is to prepare new polyurethane gels that can be used as stress‐ or pressure‐distributing materials, particularly by being combined with selective plasticizers for medical or clinical applications. Because low‐molecular‐weight plasticizer molecules in polymer gels intrinsically tend to migrate to the surface of the gels by the so‐called entropy effect in polymer miscibility, the stress‐distributing function may decrease gradually after a certain amount of time. Correspondingly, both the chemical nature of the plasticizer and polymer gels and the compatibility between the polymer segments and plasticizer should be deliberately considered as important factors in determining the thermophysical properties and stress‐distributing performance of polymer gels. New polyurethane gels comprising separated phases of soft and hard segments, the glass‐transition temperature of which was around the ambient temperature, were prepared, and selective plasticizers were combined to obtain an optimized formulation of gels for stress‐relieving properties. The glassy‐to‐rubbery transition of semicrystalline hard segments occurring around the ambient temperature caused the rearrangement of chain conformations, leading to the reduction of the pressure applied to the surface; this indicated that the pressure buildup or loss was somewhat related to the heat regulation by thermal absorption and release in the phase‐transition range. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2750–2758, 2006
Characterization of electron beam irradiated polypropylene: Influence of irradiation temperature on molecular and rheological properties
Authors: Krause Beate , Voigt Dieter , Häuβler Liane , Auhl Dietmar , Münstedt Helmut 
Published: February 2006

AbstractThe aim of the investigations was to analyze the influence of the temperature during the irradiation process of polypropylene on the molar mass, the formation of long chain branching and the final branching topology. A linear isotactic polypropylene homopolymer was modified by electron beam irradiation at different temperatures, with two irradiation doses to insert long chain branching. The samples were analyzed by size exclusion chromatography coupled with a multiangle laser light scattering detector, by differential scanning calorimetry, and by shear and elongational rheology. The shear and elongational flow behavior is discussed in terms of the influence of molecular parameters and used to analyze the topology of the irradiated samples. With increasing temperature, a slight reduction of the molar mass, an increase of long chain branching and an increase of crystallization temperature were found. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2770–2780, 2006
Effect of spinning conditions on the structure and properties of PAN fibers containing nano‐hydroxyapatite
Authors: Mikołajczyk Teresa , Boguń Maciej , Błażewicz Marta , Piekarczyk Izabella 
Published: February 2006

AbstractSpinning conditions for nano‐hydroxyapatite‐containing precursor polyacrylonitrile (PAN) fibers have been developed and their effects on the structure and properties of nanocomposite PAN fibers have been assessed. The precursor PAN fibers prepared under the developed conditions are characterized by high strength, with their total pore content being at a level of 0.25 cm3/g. After carbonization, these fibers are designed for use as implants that support and stimulate the process of bone reconstruction. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2881–2888, 2006
Synergistic effect of halide ions on the corrosion inhibition of aluminum in acidic medium by some polymers
Authors: Ebenso E. E. , Ekpe U. J. , Umoren S. A. , Jackson Ekerete , Abiola O. K. , Oforka N. C. 
Published: February 2006

AbstractThe corrosion inhibition of aluminum in H2SO4 in the presence of polyvinyl alcohol (PVA) and polyethylene glycol (PEG) and the effect of addition of halides (KCl, KBr, KI) was studied using the hydrogen evolution technique at 30 and 40°C. Inhibition efficiency (%I) increases with concentration of PVA and PEG—‐but with PEG having higher %I. The %I decrease with increase in temperature from 30 to 40°C in the absence and presence of inhibitor and halides. PVA and PEG were found to obey Freundlish adsorption isotherm. Phenomenon of physical adsorption is proposed from the obtained Ea, ΔGads, and Qads values obtained. The synergism parameters (SI) obtained were found to be greater than unity for both PVA and PEG, which indicates that the enhanced inhibition efficiency caused by the addition of halides is only due to synergism. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2889–2894, 2006
TGA analysis of γ‐irradiated linear low‐density polyethylene
Authors: Tidjani Adams , Wilkie Charles A. 
Published: February 2006

AbstractLinear low‐density polyethylene (LLDPE), based on butene‐1 or hexene‐1, was irradiated with γ‐rays under vacuum or in the presence of air. The study focused on the influence of the dose rate and the γ‐dose on the thermal properties of LLDPE. Differential scanning calorimetry, thermogravimetric analysis (TGA), and TGA/FTIR techniques were used to address the thermal behavior as a result of γ‐irradiation. During this irradiation, competition between crosslinking and scission reactions, subsequent to oxidation reactions, occurred in the polymeric material, which strongly depends on the experimental conditions. A decrease of the crystallinity for γ‐irradiated samples was observed in particular for samples irradiated under vacuum. This observation may be explained by increased hindrance of segment mobility due to crosslinking reactions that prevent crystal growth. TGA investigations revealed an enhancement of the thermal stability for samples irradiated under vacuum but not for those irradiated in air. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2790–2795, 2006
A study on the solution behavior of IPBC‐hydrophobically‐modified hydroxyethyl cellulose
Authors: Dai Shanshan , Ye Lin , Huang Ronghua 
Published: February 2006

AbstractThrough the macromolecule reaction method, a series of 4‐isopropylbenzyl chloride (IPBC) hydrophobically‐modified hydroxyethyl cellulose (HAHEC) were synthesized. The use of suitable amount of hydrophobic monomer can ensure both the strong intermolecular association and good water‐solubility of HAHEC. Effects of polymer concentration, shear rates, temperature, and electrolytes on the solution behavior of HAHEC were comprehensively studied, which indicated that the polymers show high viscosification property, excellent viscosity retention in brine water, and surface activity. FTIR, DSC, and UV measurements were applied to characterize the molecular structure and composition of HAHEC to confirm the incorporation of hydrophobic group into the polymer chain. Atomic force microscope (AFM) and fluorescence spectrum measurements were applied to study the formation of the molecule aggregation and hydrophobic microdomain of HAHEC, and revealed the close relationship between the rheological behaviors and the hydrophobic viscosification effect. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2824–2831, 2006
Principal component analysis and artificial neural network analysis of oral tissue fluorescence spectra: Classification of normal premalignant and malignant pathological conditions
Authors: Nayak G. S. , Kamath Sudha , Pai Keerthilatha M. , Sarkar Arindam , Ray Satadru , Kurien Jacob , D'Almeida Lawrence , Krishnanand B. R. , Santhosh C. , Kartha V. B. , Mahato K. K. 
Published: February 2006

AbstractPulsed laser‐induced autofluorescence spectroscopic studies of pathologically certified normal, premalignant, and malignant oral tissues were carried out at 325 nm excitation. The spectral analysis and classification for discrimination among normal, premalignant, and malignant conditions were performed using principal component analysis (PCA) and artificial neural network (ANN) separately on the same set of spectral data. In case of PCA, spectral residuals, Mahalanobis distance, and scores of factors were used for discrimination among normal, premalignant, and malignant cases. In ANN, parameters like mean, spectral residual, standard deviation, and total energy were used to train the network. The ANN used in this study is a classical multiplayer feed‐forward type with a back‐propagation algorithm for the training of the network. The specificity and sensitivity were determined in both classification schemes. In the case of PCA, they are 100 and 92.9%, respectively, whereas for ANN they are 100 and 96.5% for the data set considered. © 2006 Wiley Periodicals, Inc. Biopolymers 82: 152–166, 2006This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Antibody‐based surface plasmon resonance detection of intact viral pathogen
Authors: Baac Hyoungwon , Hajós József P. , Lee Jennifer , Kim Donghyun , Kim Sung June , Shuler Michael L. 
Published: February 2006

AbstractSurface plasmon resonance (SPR) technique was used to directly detect an intact form of insect pathogen: the baculovirus, Autographa californica multiple nuclear polyhedrosis virus (AcMNPV). An SPR sensor chip with three bio‐functional layers was used to detect the intact AcMNPV: amine‐reactive crosslinker with a disulfide bond that chemisorbs to gold film, Protein A, and a mouse IgG monoclonal antibody raised against a surface protein of the target viral pathogen. A two‐channel (reference & test) micro‐fluidic SPR system is used for reliable measurement. Bio‐specific response to the AcMNPV is compared with the response for tobacco mosaic virus (TMV) as control. Successive exposure of the sensor chip to both viruses verifies a specific response to AcMNPV. This serves as a prerequisite to the development of a new type of viral pathogen detection sensors. © 2006 Wiley Periodicals, Inc.
Salmonella typhimurium specifically chemotax and proliferate in heterogeneous tumor tissue in vitro
Authors: Kasinskas Rachel W. , Forbes Neil S. 
Published: February 2006

AbstractMulti‐drug resistance greatly limits the efficacy of conventional blood‐born chemotherapeutics, which have limited ability to penetrate tumor tissue and are ineffective at killing quiescent cells far from tumor vasculature. Nonpathogenic, motile bacteria can overcome both of theses limitations. We hypothesize that the accumulation of S. typhimurium in tumors is controlled by two mechanisms: (1) chemotaxis towards compounds produced by quiescent cancer cells and (2) preferential growth within tumor tissue. We tested this hypothesis by quantifying the relative contributions of these mechanisms using the tumor cylindroid model, which mimics the microenvironments of in vivo tumors. Time‐lapse fluorescence microscopy was used to measure the accumulation of GFP‐labeled S. typhimurium into cylindroids of different size. Cylindroids larger than 500 µm in diameter contain quiescent cells, whereas cylindroids smaller than 500 µm do not. Spatio‐temporal profiles of bacterial concentration were fit to a mathematical model to calculate two parameters that describe bacterial interaction with tumors: intratumoral bacterial growth, M, and intratumoral bacterial chemoattraction, K. It was observed that S. typhimurium is attracted to cylindroids and accumulate at long time points in the central region of large cylindroids. Both intratumoral bacterial growth and chemotaxis were significantly greater in large cylindroids, suggesting that quiescent cells secrete bacterial chemoattractants and the presence of necrotic and quiescent cells enable S. typhimurium to replicate in tumor tissue. In this study, several mechanisms of S. typhimurium accumulation in solid tumors have been quantified, which we believe is an important step in the development of bacterial‐based therapeutics to target tumor quiescence. © 2006 Wiley Periodicals, Inc.
Simultaneous control of turbidity and dilution rate through adjustment of medium composition in semi‐continuous Chlamydomonas cultures
Authors: Maeda Isamu , Seto Yoshiaki , Ueda Shunsaku , Cheng Yukoh , Hari Junko , Kawase Masaya , Miyasaka Hitoshi , Yagi Kiyohito 
Published: February 2006

AbstractFor production of starch in algal cultures, a growth rate limited by a nutrient is an important factor. Under phototrophic conditions, turbidity must be also paid attention, as the shading effect may affect its productivity. Semi‐continuous cultivation methods, which enable control of turbidity and dilution rate (D) at the same time, have been developed for evaluation of those factors on starch production in Chlamydomonas sp. A specific feature of the methods is in a process of alternately feeding medium adjusted at two different nitrogen (N) concentrations. In the turbidostat‐based method, a turbidostat culture was operated repeating three steps of determining D within a preset interval, alternating media by comparing the D with a preset value, and adjusting D in the next interval by feeding the selected medium. In the chemostat‐based method, turbidity of a chemostat culture was controlled by repeating two steps of alternating media by comparing transmitted photon flux intensity (I) with a preset value and adjusting I by feeding the selected medium. D controlled by the turbidostat‐based method reached quickly a preset value as low as 0.010/h, and then it was dispersed around but above the preset value. On the other hand, mean N concentrations of fed media formed a plateau. In the chemostat‐based method, I was well controlled to a preset value while the mean N concentrations were a bit fluctuated. Starch concentration varied from 0.052 to 0.41 g/L with turbidity and D defined by these methods. © 2006 Wiley Periodicals, Inc.
Simultaneous quantification of atorvastatin and active metabolites in human plasma by liquid chromatography–tandem mass spectrometry using rosuvastatin as internal standard
Authors: Nirogi Ramakrishna V. S. , Kandikere Vishwottam N. , Shukla Manoj , Mudigonda Koteshwara , Maurya Santosh , Boosi Ravikumar , Anjaneyulu Yerramilli 
Published: February 2006

AbstractA simple, sensitive, selective and rapid liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method was developed and validated for the quantification of atorvastatin and its active metabolitesortho‐hydroxyatorvastatin andpara‐hydroxyatorvastatin in human plasma using rosuvastatin as internal standard (IS). Following simple liquid–liquid extraction, the analytes were separated using an isocratic mobile phase on a reversed‐phase C18column and analyzed by MS in the multiple reaction monitoring mode using the respective [M+H]+ions,m/z559/440 for atorvastatin,m/z575/466 forortho‐hydroxyatorvastatin,m/z575/440 for para‐hydroxyatorvastatin andm/z482/258 for the IS. The assay exhibited a linear dynamic range of 0.1–20 ng/mL for atorvastatin and its two metabolites in human plasma. The lower limit of quantification was 100 pg/mL with a relative standard deviation of less than 8%. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. The average absolute recoveries of atorvastatin,ortho‐hydroxyatorvastatin, para‐hydroxyatorvastatin and the IS from spiked plasma samples were 54.2 ± 3.2, 50.1 ± 3.8, 65.2 ± 3.6 and 71.7 ± 2.7%, respectively. A run time of 2.5 min for each sample made it possible to analyze more than 300 human plasma samples per day. The validated method has been successfully used to analyze human plasma samples for application in pharmacokinetic, bioavailability or bioequivalence studies. Copyright © 2006 John Wiley & Sons, Ltd.
Purification of a crystallin domain of Yersinia crystallin from inclusion bodies and its comparison to native protein from the soluble fraction
Authors: Jobby M. K. , Sharma Yogendra 
Published: February 2006

AbstractIt has been established that many heterologously produced proteins in E. coli accumulate as insoluble inclusion bodies. Methods for protein recovery from inclusion bodies involve solubilization using chemical denaturants such as urea and guanidine hydrochloride, followed by removal of denaturant from the solution to allow the protein to refold. In this work, we applied on‐column refolding and purification to the second crystallin domain D2 of Yersinia crystallin isolated from inclusion bodies. We also purified the protein from the soluble fraction (without using any denaturant) to compare the biophysical properties and conformation, although the yield was poor. On‐column refolding method allows rapid removal of denaturant and refolding at high protein concentration, which is a limitation in traditionally used methods of dialysis or dilution. We were also able to develop methods to remove the co‐eluting nucleic acids during chromatography from the protein preparation. Using this protocol, we were able to rapidly refold and purify the crystallin domain using a two‐step process with high yield. We used biophysical techniques to compare the conformation and calcium‐binding properties of the protein isolated from the soluble fraction and inclusion bodies. Copyright © 2006 John Wiley & Sons, Ltd.
Fast display of large‐scale forest with fidelity
Authors: Zhang Huaisheng , Hua Wei , Wang Qing , Bao Hujun 
Published: February 2006

AbstractWe propose a new hierarchical representation for a forest model, namely hierarchical layered depth mosaics (HLDM). Each node in the HLDM comprises a number of discrete textured quadrilaterals, called depth mosaics (DMs). The DMs are generated from the sampled depth images of the polygonal tree models. Meanwhile, their textures are compressed by a new approach accounting for occlusion. Our rendering procedure traverses the HLDM and renders the appropriate nodes according to a view‐dependent selection criterion. A blending scheme is adopted to mitigate the visual ‘popping’ caused by the transition of levels of detail. The experiment demonstrates that the viewer could interactively walk or fly above the forest with fidelity. Copyright © 2006 John Wiley & Sons, Ltd.