bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of the Addition of Lauric Acid to Films Made from Gelatin, Triacetin and a Blend of Stearic and Palmitic Acids
Authors: Canhadas Bertan Larissa , Matta Fakhouri Farayde , Siani Antonio Carlos , Ferreira Grosso Carlos Raimundo 
Published: November 2005

AbstractSummary:The objective of this research was to verify the influence of adding increasing amounts of lauric acid on the functional properties of homogenized films made from gelatin, triacetin and a blend of palmitic and stearic acids. The films were characterised with respect to their visual aspect, water vapour permeability (WVP), water solubility, mechanical properties (tensile strength and percent elongation), oxygen permeability (O2P), opacity (OP) and melting and glass transitions temperatures. The films produced were malleable and macroscopically homogeneous. The addition of 1% of lauric acid to the film of gelatin, triacetin and blend of palmitic and stearic acids (5.84 ± 0.31 gmm · m−2dkPa) caused a slight decrease in WVP. The additions of 2.5% (5.70 ± 0.76 gmm · m−2dkPa), 5% (5.38 ± 0.64 gmm · m−2dkPa) and 10% (4.50 ± 0.55 gmm · m−2dkPa) of lauric acid were sufficient to make a significant difference in the WVP at the higher levels used. As compared to the gelatin and triacetin film, the addition of lauric acid at all the concentrations studied resulted in a slight increase in the film solubility. The addition of hydrophobic substances to gelatin/triacetin films (15.26 ± 0.28 cm3 · µm · m−2dkPa) favoured an increase in O2P permeability, this effect being greater in the films made from gelatin, triacetin, blend of palmitic and stearic acids and 10% lauric acid (24.48 ± 0.07 cm3 · µm · m−2dkPa). The increasing addition of lauric acid significantly reduced the tensile strength and increased elongation of the films composed of gelatin, triacetin and blend that being more evident at the concentrations of 5% (67.58 ± 1.23 MPa and 11.45 ± 0.57%) and 10% (63.50 ± 1.56 MPa and 12.90 ± 0.57%). The addition of 1% (OP, 27%) and 10% (OP, 28%) of lauric acid induced no visible effect on the opacity of the films. The thermogrammes showed three transitions for the gelatin/triacetin/stearic‐palmitic blend/1% lauric acid films (−57.42 °C, 23.74 °C and 44.11 °C) and two for the gelatin/triacetin/stearic‐palmitic acids blend/10% lauric acid films (−56.22 °C and 17.35 °C). As observed by DSC, the addition of fatty acids resulted in the appearance of more than one melting peak for all films in relation to the gelatin and triacetin film.
Rheological Behavior and Scattering Studies of Acrylamide‐Based Copolymer Solutions
Authors: Maia Ana M. S. , Costa Marta , Borsali Redouane , Garcia Rosangela B. 
Published: November 2005

AbstractSummary:In this paper the chemical structure of an acrylamide‐N,N‐dihexylacrylamide copolymer was established by IR and NMR. Static and dynamic light scattering in formamide were used in order to evaluate the polymer structural parameters, such as weight‐average molecular weight (Mw), second virial coefficient (A2), radius of gyration (RG), the form factorP(q) and the hydrodynamic radius (RH). Additionally to the classical characterization, those results indicated the presence of aggregation, showing that formamide is not a very good solvent, as stated in earlier investigations. The rheological behavior in aqueous solutions was evaluated as a function of the salt concentration. The solutions presented an important viscosity increase in the presence of NaCl and did not show any sensitivity to the presence of CaCl2. This result is in favor of the oil recovery especially in high salinity reservoirs.
Preparation and Characterization of Poly(D,L‐Lactide) (PLA) and Poly(D,L‐Lactide)‐Poly(Ethylene Glycol) (PLA‐PEG) Nanocapsules Containing Antitumoral Agent Methotrexate
Authors: de Faria Tatiany J. , Machado de Campos Angela , Lemos Senna Elenara 
Published: November 2005

AbstractSummary: The aims of the present work were to prepare and characterize nanocapsules containing antitumoral agent methotrexate (MTX) from poly(D,L‐lactide) (PLA) and poly(D,L‐lactide)‐poly(ethylene glycol) diblock copolymer (PLA‐PEG) with the purpose of administrating this drug by topical ocular route for primary ocular lymphoma treatment. Nanocapsules were prepared by the interfacial deposition of preformed polymer. The influences of the initial amount of MTX on the encapsulation efficiency, drug recovery and drug content, as well as the physicochemical properties of the particles were evaluated. The particle mean diameters were 246 and 146 nm, and zeta potential values were −38.8 and −33.6 mV, for the MTX‐loaded nanocapsules prepared from PLA and PLA‐PEG, respectively. The methotrexate content in the particles increased with the increasing in the drug amount added to the formulations, but the drug recovery decreased significantly. After 4 h of in vitro release, 28 and 86% of MTX was released from PLA and PLA‐PEG nanocapsules, respectively.
Use of Natural Monomer in the Synthesis of Nano‐ and Microparticles of Polyurethane by Suspension‐Polyaddition Technique
Authors: Zanetti‐Ramos Betina , Soldi Valdir , Lemos‐Senna Elenara , Borsali Redouane 
Published: November 2005

AbstractSummary: Polyurethane nano‐ and microparticles were synthesized by suspension‐polyaddition technique, using aqueous polymerization medium. Castor oil, a vegetable triglyceride possessing hydroxyl groups was used as natural polyol and methylene diphenyl diisocyanate (MDI) as isocyanate. The levofloxacin, an antibacterial drug was used as model drug to measure the particles encapsulation efficiency. The effect of the addition of a second polyol, the poly(ethylene glycol) (PEG), and the stirring rate on the mean diameter and morphology of particles was also investigated. The poly(ethylene glycol) has an important effect in the reduction of particles size and their porosity. On the other hand, the poly(ethylene glycol) reduced the yield of encapsulation from 70% for the formulation without PEG to 20% for formulations with PEG. FTIR analysis confirmed the polyurethane formation. Dynamic light scattering study, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to determine the nanoparticles size and shape. Spectrofluorimetric analysis was used to detect the levofloxacin.
Malonylchitosan Microspheres as a Matrix for Oral Enrofloxacin Delivery
Authors: Valgas Saléte , Gonçalves Vanessa Lima , Laranjeira Mauro C. M. , Fávere Valfredo T. , Pedrosa Rozangela Curi 
Published: November 2005

AbstractSummary: The purpose of this study was to produce malonylchitosan microspheres to be used as a pH sensitive matrix for the controlled delivery of drugs. Chitosan microspheres were obtained by the coacervation–phase separation method. The microspheres were then treated with malonic acid to obtain amidified chitosan microspheres. The resulting malonylchitosan microspheres were characterized by means of elemental analysis (CHN), infrared spectroscopy, conductometric titration and scanning electron microscopy (SEM). The data obtained from infrared spectroscopy, elemental analysis and conductometric titration of amino groups were consistent with the N‐substitution of malonyl groups in the chitosan microspheres. In vivo studies for controlled delivery of enrofloxacin were performed in male Wistar rats and the results indicated increase and prolonged blood levels with delayed peak and improved bioavailability for malonylchitosan microspheres compared to commercial tablets.
Effects of Neutralization Process on Preparation and Characterization of Chitosan Membranes for Wound Dressing
Authors: Nogueira Campos Maria Gabriela , Ferreira Grosso Carlos Raimundo , Cárdenas Galo , Inocentinni Mei Lucia Helena 
Published: November 2005

AbstractSummary: Neutralization process effects on preparation and characterization of chitosan membranes were evaluated by differencial scanning calorimetry and scanning electron microscopy. Water solubility and humidity of chitosan membranes were also studied. Swelling behavior in different pH media was evaluated and mechanical properties such as tensile strength and elongation at break were measured. Neutralization process increased glass transition temperature of chitosan membranes and decreased their water solubility, humidity and water sorption. An improvement in mechanical properties of chitosan membranes was also observed after neutralization process.
Preparation and Characterisation of Thermoplastic Starches from Cassava Starch, Cassava Root and Cassava Bagasse
Authors: de Morais Teixeira Eliangela , Da Róz Alessandra Luzia , de Carvalho Antonio José Felix , da Silva Curvelo Antonio Aprigio 
Published: November 2005

AbstractSummary: Thermoplastic starches (TPS) based on cassava starch have been produced by extrusion at 120 °C, using glycerol as plasticizer. Three forms of cassava starch were employed, viz: cassava root (CR), cassava bagasse (CB) and purified cassava starch (PCS). The main differences between these are the presence of sugars and a few fibres in CR and high fibre concentration in CB. Conditions of processing and characteristics such as amylose and fibre content, crystallinity, water absorption and mechanical behaviour in the tension x deformation test were evaluated. The results demonstrated that the PCS and CR had amylose contents consistent with literature values (14–18%) and that CB is a material constituted mainly by amylopectin. It was found that fibres in high proportions (as in the bagasse) can confer reinforcement properties and are thus able to generate natural composites of TPS with cellulose fibre. The sugars naturally found in the root reduce the elongation of the TPS under tension. The PCS and CR TPS were stable with respect to indices of crystallinity after processing; and during a period of 90 d in a relative humidity of 53%, while the CB TPS tended to vary its crystallinity, probably because its amylose chain had low degree of polymerization.
Miscibility and Mechanical Behavior of SAN/NBR Blends
Authors: Ziquinatti Francine , Hugen Roberson G. , Oliveira César M. , Coelho Luiz A. F. , Pezzin Sérgio H. 
Published: November 2005

AbstractSummary: Aiming the development of high toughness polymer materials, blends of poly(styrene‐co‐acrylonitrile) (SAN) and poly(butadiene‐co‐acrylonitrile) (NBR) rubbers, with contents of acrylonitrile (AN) varying from 21 to 45%, were prepared by casting, coprecipitation and monoscrew extrusion followed by injection molding. SAN/NBR blends, prepared in the compositions (w/w) 90/10, 80/20, 70/30, 60/40, and 50/50, were characterized by differential scanning calorimetry (DSC) and Izod impact tests. DSC analyses showed that blends with 33% AN NBR prepared by casting, and with 39% AN NBR prepared by coprecipitation, are partially miscible at 60/40, 70/30 and 80/20 (SAN/NBR) compositions and immiscible for 50/50 compositions. On the other hand, 90/10 SAN/NBR systems were totally miscible. The blends with 45% AN NBR prepared by coprecipitation showed partial miscibility to 50/50, 60/40, 70/30 and 90/10 compositions and total miscibility to 80/20 composition. The NBR addition results in a significant increase in the impact resistance, strongly dependent on the blend composition and the NBR AN content. The best result of impact resistance — 75.2 ± 8.6 (kJ · m−2) — was obtained for SAN/NBR 50/50, using 45% AN NBR. This value is 15.7 times bigger than that for pure SAN ‐4.8 ± 0.7 (kJ · m−2).
Development of a Kinetic Model for Thermal Crosslinking of Rubbery Polymers
Authors: Vivaldo‐Lima Eduardo , Roa‐Luna Martha , Saldívar‐Guerra Enrique 
Published: November 2005

AbstractSummary: A kinetic model for the thermal crosslinking of rubbery polymers is presented. The reaction mechanism used to develop the model includes thermal radical generation producing a polymeric radical and a primary radical, crosslinking from attack of a polymer radical to any inactive polymer molecule, bimolecular radical termination among chains of any degree of branching, and radical termination between a polymer radical and a primary radical from the thermal radical generation. The overall polymer population is divided into “generations”, which are defined in terms of the number of primary (linear) chains of original rubbery polymer attached to the polymer molecule. Mass balances for each generation are written down, and expressions to calculate fraction of branched molecules, gel fraction, and number and weight average chain lengths are derived. Model simulations, parameter sensitivity analyses and preliminary parameter estimation studies are presented, taking the thermal crosslinking of linear polybutadiene as a case study.Development of a kinetic model for thermal crosslinking of rubbery polymers: reaction mechanism, model equations and parameter sensitivity analyses.magnified imageDevelopment of a kinetic model for thermal crosslinking of rubbery polymers: reaction mechanism, model equations and parameter sensitivity analyses.
A New Simulation Algorithm with Revised “Association Criteria” for Studying the Association of Heteroarm Star Copolymers
Authors: Havránková Jitka , Limpouchová Zuzana , Procházka Karel 
Published: November 2005

AbstractSummary: A new computational algorithm for dynamic lattice Monte Carlo simulations of the associative behavior of heteroarm copolymers in selective solvents was developed and optimized for efficient and relatively fast simulation studies. The algorithm is based on the Siepmann and Frenkel variant of the bias self‐avoiding walk procedure. Simultaneously, a new criterion for recognition of an associate was proposed. The first results on the micellization of heteroarm star copolymers are presented.
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Prolonged limb allograft survival with CD40 costimulation blockade, T‐cell depletion, and megadose donor bone‐marrow transfusion
Authors: Tung Thomas H. , Mackinnon Susan E. , Mohanakumar T. 
Published: November 2005

AbstractThe purpose of this study was to determine the efficacy of a treatment regimen consisting of CD40 costimulation blockade, T‐cell depletion, and megadose donor bone marrow transfusion in the limb allograft model. C57Bl/6 mice underwent limb transplantation from Balb/c mice and received MR1 (anti‐CD40 ligand monoclonal antibody), and CD4+ and CD8+ T cell‐depleting antibodies with and without 120 × 106 donor bone‐marrow transfusion. Recipients treated only with antibodies showed rejection at 51.4 ± 17 (mean ± SEM) days, while those who also received donor bone marrow had allograft survival of 67 ± 16.4 days, with a range up to 91 days. Treated specimens with rejection had less lymphocytic infiltration than untreated controls. Recipients of donor bone marrow also demonstrated early mixed chimerism, which disappeared after 1 month. While allograft survival was prolonged, tolerance was not achieved, and the mechanism of rejection was more consistent with a chronic process. © 2005 Wiley‐Liss, Inc. Microsurgery 25:624–631, 2005.
Gradual graft‐cell repopulation with recipient cells following vasularized bone and limb allotransplantation
Authors: Muramatsu Keiichi , Kurokawa Yoko , Kuriyama Ryutaro , Taguchi Toshihiko , Bishop Allen T. 
Published: November 2005

AbstractLittle is known about the fate of graft cells following vascularized bone allografting. This study was conducted to define the process of graft‐cell repopulation with recipient cells. Sixty‐five vascularized tibial bone and 50 limb allotransplantations were performed in rat sex‐mismatched pairs. FK506 was used for immunosuppression. The ratio of donor and recipient cells in the graft was evaluated by semiquantitative polymerase chain reaction, using the Y‐chromosome primers. Allografted bones had no rejection episodes. In the vascularized bone allograft model, donor‐derived cells were gradually replaced by cells of recipient origin, such that by 24 weeks, they comprised only 10% of total cells. In the limb allograft model, male recipient cells were detected in female grafts not at 1 week but at 48 weeks posttransplantation. The ratio of recipient cells was more than 10% in the femur and tibia. Recipient‐derived cells gradually migrated into the grafted bone cells with the passage of time. © 2005 Wiley‐Liss, Inc. Microsurgery 25:599–605, 2005.
Inhibition of iNOS attenuates skeletal muscle reperfusion injury in extracellular superoxide dismutase knockout mice
Authors: Park Jong Woong , Qi Wen‐Ning , Liu John Q. , Urbaniak James R. , Folz Rodney J. , Chen Long‐En 
Published: November 2005

AbstractReactive oxygen species (ROS) and reactive nitrogen species (RNS) are closely involved in the mechanism of skeletal muscle ischemia/reperfusion (I/R) injury. This study was designed to determine the effects of inducible nitric oxide synthase (iNOS) inhibitor 1400W on the reperfused cremaster muscle in extracellular superoxide dismutase knockout (EC‐SOD−/−) mice. The muscle was exposed to 4.5 h of ischemia, followed by 90 min of reperfusion. Mice received either 3 mg/kg of 1400W or the same amount of phosphate‐buffered saline (PBS, as a control) subcutaneously at 10 min before the start of reperfusion. 1400W treatment markedly improved the recovery speed of vessel diameter and blood flow in the reperfused cremaster muscle of EC‐SOD−/− mice compared to controls. Histological examination showed reduced edema in the interstitial space and muscle fiber, and reduced density of nitrotyrosine (a marker of total peroxinitrite (ONOO−) level) in 1400W‐treated muscles compared to controls. Our results suggest that iNOS and ONOO− products are involved in skeletal muscle I/R injury. Reduced I/R injury by using selective inhibition of iNOS perhaps works by limiting cytotoxic ONOO− generation, a reaction product of nitric oxide (NO) and superoxide anion (O2−). Thus, inhibition of iNOS appears to be a treatment strategy for reducing clinical I/R injury. © 2005 Wiley‐Liss, Inc. Microsurgery 25:606–613, 2005.
Blow up, decay bounds and continuous dependence inequalities for a class of quasilinear parabolic problems
Authors: Payne L. E. , Philippin G. A. , Vernier‐Piro S. 
Published: November 2005

AbstractThis paper deals with a class of semilinear parabolic problems. In particular, we establish conditions on the data sufficient to guarantee blow up of solution at some finite time, as well as conditions which will insure that the solution exists for all time with exponential decay of the solution and its spatial derivatives. In the case of global existence, we also investigate the continuous dependence of the solution with respect to some data of the problem. Copyright © 2005 John Wiley & Sons, Ltd.
Long‐range JCH heteronuclear coupling constants in cyclopentane derivatives
Authors: Lacerda Valdemar , da Silva Gil V. J. , Constantino Mauricio G. , Tormena Cláudio F. , Williamson R. Thomas , Marquez Brian L. 
Published: November 2005

AbstractDetailed measurements of long‐range heteronuclear spin–spin coupling constants, especially 2, 3JCH spin–spin couplings for various cyclopentane derivatives, are reported. The measurements are based on a 2D heteronuclear correlation experiment named G‐BIRDR, X‐CPMG‐HSQMBC. Copyright © 2005 John Wiley & Sons, Ltd.
Simultaneous phase correction and SENSE reconstruction for navigated multi‐shot DWI with non‐cartesian k‐space sampling
Authors: Liu Chunlei , Moseley Michael E. , Bammer Roland 
Published: November 2005

AbstractPhase‐navigated multi‐shot acquisition and parallel imaging are two techniques that have been applied to diffusion‐weighted imaging (DWI) to diminish distortions and to enhance spatial resolution. Specifically, sensitivity encoding (SENSE) has been combined with single‐shot echo planar imaging (EPI). Thus far, it has been difficult to apply parallel imaging methods, like SENSE, to multi‐shot DWI because motion‐induced phase error varies from shot to shot and interferes with sensitivity encoding. Although direct phase subtraction methods have been introduced to correct this phase error, they generally are not suitable for SENSE reconstruction, and they cannot remove all the motion artifacts even if the phase error is fully known. Here, an effective algorithm is proposed to correct the motion‐induced phase error using an iterative reconstruction. In this proposed conjugate‐gradient (CG) algorithm, the phase error is treated as an image encoding function. Given the complex perturbation terms, diffusion‐weighted images can be reconstructed using an augmented sensitivity map. The mathematical formulation and image reconstruction procedures of this algorithm are similar to the SENSE reconstruction. By defining a dynamic composite sensitivity, the CG phase correction method can be conveniently incorporated with SENSE reconstruction for the application of multi‐shot SENSE DWI. Effective phase correction and multi‐shot SENSE DWI (R = 1 to 3) are demonstrated on both simulated and in vivo data acquired with PROPELLER and SNAILS. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
In vivo carbon‐13 magnetization transfer effect. Detection of aspartate aminotransferase reaction
Authors: Shen Jun 
Published: November 2005

AbstractOne of the most remarkable achievements of in vivo NMR spectroscopy has been the detection of rapid enzyme‐catalyzed exchange reactions using phosphorus‐31 magnetic resonance spectroscopy‐based magnetization transfer experiments. In this paper, we report, for the first time, the in vivo carbon magnetization transfer (CMT) effect and in vivo detection of the CMT effects of the α‐ketoglutarate ↔ glutamate and the oxaloacetate ↔ aspartate reactions, both of which are catalyzed by aspartate aminotransferase. By saturating the carbonyl carbon of α‐ketoglutarate at 206 ppm in α‐chloralose anesthetized adult rat brain, the unidirectional glutamate → α‐ketoglutarate flux was determined to be 78 ± 9 μmol/g/min (mean ± SD, n = 11) following i.v. infusion of [1,6‐13C2]D‐glucose. Contribution from aspartate aminotransferase‐catalyzed partial reactions to the observed CMT effects was emphasized. Because of the large chemical shift separation between the α‐carbons of the amino acids and the carbonyl carbons of the corresponding cognate keto acids, the spillover of the saturation radiofrequency pulses to the α‐carbon resonances was negligible. The results indicate that the magnetization transfer effects of aspartate aminotransferase‐catalyzed reactions can be used as new biomarkers accessible to non‐invasive in vivo magnetic resonance spectroscopy techniques. Magn Reson Med, 2005. Published 2005 Wiley‐Liss, Inc.
Quantifying the spatial resolution of the gradient echo and spin echo BOLD response at 3 Tesla
Authors: Parkes Laura M. , Schwarzbach Jens V. , Bouts Annemieke A. , Deckers Roel h R. , Pullens Pim , Kerskens Christian M. , Norris David G. 
Published: November 2005

AbstractThe blood oxygen level dependent (BOLD) response, as measured with fMRI, offers good spatial resolution compared to other non‐invasive neuroimaging methods. The use of a spin echo technique rather than the conventional gradient echo technique may further improve the resolution by refocusing static dephasing effects around the larger vessels, so sensitizing the signal to the microvasculature. In this work the width of the point spread function (PSF) of the BOLD response at a field strength of 3 Tesla is compared for these two approaches. A double echo EPI pulse sequence with simultaneous collection of gradient echo and spin echo signal allows a direct comparison of the techniques. Rotating multiple‐wedge stimuli of different spatial frequencies are used to estimate the width of the BOLD response. Waves of activation are created on the surface of the visual cortex, which begin to overlap as the wedge separation decreases. The modulation of the BOLD response decreases with increasing spatial frequency in a manner dependent on its width. The spin echo response shows a 13% reduction in the width of the PSF, but at a cost of at least 3‐fold reduction in contrast to noise ratio. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.