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Stabilizers
Kinds of Stabilizers Terms modified by Stabilizers Selected AbstractsA Simple Atraumatic Clamp Technique Without a Stabilizer in Off-Pump CABG: How to Do ItJOURNAL OF CARDIAC SURGERY, Issue 5 2005Nezihi Kucukarslan M.D. The technique exposes and immobilizes the coronary artery, allowing a precise anastomosis on the beating heart. In addition, it is simple, safe, and inexpensive. [source] Gold Nanoparticles Embedded in a Mesoporous Carbon Nitride Stabilizer for Highly Efficient Three-Component Coupling Reaction,ANGEWANDTE CHEMIE, Issue 34 2010Träger mit Dreifachfunktion: Au-Nanopartikel mit Größen unter 7,nm wurden in den Kanälen eines mesoporösen Kohlenstoffnitrid(MCN)-Trägers hergestellt, der als Stabilisator, zur Größenkontrolle und als Reduktionsmittel fungiert (siehe Bild; Au-NPs grün). Die eingebetteten, gut dispergierten Au-Nanopartikel sind hoch aktive, selektive und wiederverwendbare Katalysatoren in der Dreikomponentenkupplung von Benzaldehyd, Piperidin und Phenylacetylen zur Synthese von Propargylamin. [source] Synthesis of Gold Microplates Using Bovine Serum Albumin as a Reductant and a StabilizerCHEMISTRY - AN ASIAN JOURNAL, Issue 1 2010Leslie Au Abstract Gold microplates were synthesized in aqueous solutions by reducing HAuCl4 with the hydroxyl groups in both serine and threonine of bovine serum albumin (BSA), which is a globular protein in its native state. In this article, we systematically investigated the effects of temperature, pH value, the concentration of BSA, and ionic species on the reduction kinetics and thus the size and morphology of the final product. The optimal experimental conditions for producing uniform Au microplates include the following: an elevated temperature in the range of 55,65,°C, an acidic solution with pH,3, and the presence of NaCl (0.14,M). We found that if any one of these parameters was deviated from the optimal condition, Au microplates would not be formed in high yields. We also found that the surfaces of the as-synthesized Au microplates were covered by a dense array of BSA bumps. [source] Are antidepressants safe in the treatment of bipolar depression?ACTA PSYCHIATRICA SCANDINAVICA, Issue 5 2008A critical evaluation of their potential risk to induce switch into mania or cycle acceleration Objective:, To address whether switch of depression into hypomania or mania or cycle acceleration in patients with bipolar disorder is caused by antidepressants or whether this phenomenon is attributable to the natural history of bipolar disorder itself. Method:, A critical review of the literature, pointing at sources of bias that have been previously overlooked. For examining the causation in question, the Bradford,Hill criteria were applied, i.e. specificity of the potential causative agent, strength of effect, consistency in findings, dose,response relation, temporal relation with exposure to agent preceding effect and biological plausibility. Results:, There is a scarcity of randomized studies addressing the question, and the available studies all suffer from various forms of bias. However, there is some evidence suggesting that antidepressants given in addition to a mood stabilizer are not associated with an increased rate of switch when compared with the rate associated with the mood stabilizer alone. Conclusion:, When combined with a mood stabilizer, antidepressants given for acute bipolar depression seemingly do not induce a switch into hypomania or mania. Whether antidepressants may accelerate episode frequency and/or may cause other forms of destabilization in patients with bipolar disorder remain to be properly studied. [source] A design for robust power system stabilizer by means of H, control and particle swarm optimization methodELECTRONICS & COMMUNICATIONS IN JAPAN, Issue 8 2008Yoshifumi Zoka Abstract This paper proposes two types of PSS design methods that take into account robustness for comparably large power systems. The first one is a design method based on , control theory and the second one is a parameter determination method for a standard PSS by using Particle Swarm Optimization (PSO). In order to deal with large-scale systems, a reduced model is developed to get the target system which preserves major oscillation modes only. The major oscillation modes are selected by using the residue concept, and the PSS is designed based on the target system. In order to verify effectiveness, the proposed methods are compared with the other previously proposed method based on a Genetic Algorithm (GA) through many numerical simulations. © 2008 Wiley Periodicals, Inc. Electron Comm Jpn, 91(8): 34,43, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10132 [source] Plasma Concentrations of Risperidone and Olanzapine during Coadministration with OxcarbazepineEPILEPSIA, Issue 5 2005Maria Rosaria Muscatello Summary:,Purpose: Oxcarbazepine (OZC) is a second-generation antiepileptic drug (AED) that also may be used as a mood stabilizer. Unlike carbamazepine (CBZ), which is an inducer of the cytochrome P-450 isoforms and may accelerate the elimination of several therapeutic agents, OXC seems to have only a modest inducing action. The aim of this investigation was to evaluate the effect of a treatment with OXC on plasma concentrations of the new antipsychotics risperidone and olanzapine. Methods: OXC, at a dosage of 900,1,200 mg/day, was administered for 5 consecutive weeks to 25 outpatients, 10 men and 15 women, aged 25 to 64 years, with bipolar or schizoaffective disorder. Twelve patients were stabilized on risperidone therapy (2,6 mg/day) and 13 on olanzapine (5,20 mg/day). Steady-state plasma concentrations of risperidone and its active metabolite 9-hydroxyrisperidone (9-OH-risperidone) and olanzapine were measured by high-pressure liquid chromatography (HPLC) before addition of OXC and after 5 weeks from the start of adjunctive treatment. Results: OXC caused only minimal and no significant changes in the mean plasma levels of risperidone (from 5.6 ± 3.6 ng/ml at baseline to 4.8 ± 2.6 ng/ml at week 5), 9-OH-risperidone (from 23.6 ± 7.5 to 24.7 ± 7.4 ng/ml), and olanzapine (from 26.5 ± 5.7 ng/ml at baseline to 27.8 ± 5.1 ng/ml). OXC coadministration with either risperidone or olanzapine was well tolerated. Conclusions: Our findings indicate that OXC does not affect the elimination of risperidone and olanzapine, thus confirming its weak inducing effect on hepatic drug-metabolizing enzymes. [source] Screening of the Interactions Between Mg-PSZ and TRIP-Steel and Its Alloys During Sintering,ADVANCED ENGINEERING MATERIALS, Issue 6 2010Christian Weigelt Ceramic,steel compound materials are used in a wide range of applications up to date. Major advantages are the mechanical properties due to the combination of brittle ceramic with tough steel. This study deals with effects of the sintering process on austenitic TRIP-steel/Mg-PSZ composite materials for mechanical load applications. Both, the FeCrNisteel and partially stabilized zirconia offer their special mechanical behavior only in a metastable state. The ability of phase transformation depends mainly on the chemical composition. Mutual interactions of the alloying metals (Cr, Ni, Mn, and Fe) and the ceramic stabilizer (MgO) during sintering may prevent the martensitic phase transformation. This may cause disadvantageous mechanical behavior on mechanical load in use. [source] Plant fructans stabilize phosphatidylcholine liposomes during freeze-dryingFEBS JOURNAL, Issue 2 2000Dirk K. Hincha Fructans have been implicated as protective agents in the drought and freezing tolerance of many plant species. A direct proof of their ability to stabilize biological structures under stress conditions, however, is still lacking. Here we show that inulins (linear fructose polymers) isolated from chicory roots and dahlia tubers stabilize egg phosphatidylcholine large unilamellar vesicles during freeze-drying, while another polysaccharide, hydroxyethyl starch, was completely ineffective. Liposome stability was assessed after rehydration by measuring retention of the soluble fluorescent dye carboxyfluorescein and bilayer fusion. Inulin was an especially effective stabilizer in combination with glucose. Analysis by HPLC showed that the commercial inulin preparations used in our study contained no low molecular mass sugars that could be responsible for the observed stabilizing effect of the fructans. Fourier transform infrared spectroscopy showed a reduction of the gel to liquid-crystalline phase transition temperature of dry egg PtdCho by more than 20 °C in the presence of inulin. A direct interaction of inulin with the phospholipid in the dry state was also indicated by dramatic differences in the phosphate asymmetric stretch region of the infrared spectrum between samples with and without the polysaccharide. [source] [Ru(0)]@SiO2 and [RuO2]@SiO2 Hybrid Nanomaterials: From Their Synthesis to Their Application as Catalytic Filters for Gas SensorsADVANCED FUNCTIONAL MATERIALS, Issue 23 2009Victor Matsura Abstract [Ru(0)]@SiO2 and [RuO2]@SiO2 hybrid nanomaterials are produced following a facile method consisting of the synthesis of size-controlled ruthenium nanoparticles as elemental bricks. This route takes advantage of the organometallic approach and the use of a bifunctional ligand for the synthesis of ruthenium nanoparticles from [Ru(COD)(COT)](COD,=,1,3-cyclooctadiene, COT,=,1,3,5-cyclooctatriene) as metal precursor and (PhCH2)2N(CH2)11O(CH2)3Si(OEt)3 (benzenemethanamine) as stabilizer. Hydrolysis and polycondensation steps via a sol,gel approach lead to the formation of the silica materials containing the metal nanoparticles. A final calcination step in air at 400,°C yields the [RuO2]@SiO2 nanocomposites. Such hybrid nanomaterials display a good dispersion of the nanoparticles inside the silica matrix and interesting porosity properties making them attractive materials for catalytic applications. This is shown by using [RuO2]@SiO2 hybrid nanomaterials as catalytic filters for gas sensors. [source] REVIEW ARTICLE: An improved manufacturing process for Xyntha/ReFacto AFHAEMOPHILIA, Issue 5 2010B. KELLEY Summary., ReFacto® Antihemophilic Factor is a second-generation antihaemophilia A product manufactured using a process that includes therapeutic grade human serum albumin (HSA) in the cell culture medium, but is formulated without HSA as a stabilizer. Even though this second-generation antihaemophilia product has a good safety profile, a programme was implemented to eliminate all animal- and human-derived raw materials from the production process, thus producing a third-generation product. To that end, HSA has been removed from the master and working cell banks and from the culture medium. The hybridoma-derived monoclonal antibody formerly used in the purification process has been replaced by a chemically synthesized affinity peptide, and a virus-retaining filtration step has been added to enhance the clearance of large viruses, such as retroviruses. The purification process has been validated for the removal of a panel of model viruses and provides significant clearance of all viruses tested. Host cell- and process-derived impurity removal validations also were conducted, including host cell DNA and protein, in addition to the affinity peptide. Compared with the product manufactured according to the original process, these changes had no detectable effect on the structural integrity, stability or clinical efficacy of this antihaemophilia A product. The product produced by the improved manufacturing process is named XynthaÔ/ReFacto AF. [source] European data of a clinical trial with a sucrose formulated recombinant factor VIII in previously treated haemophilia A patientsHAEMOPHILIA, Issue 2002C. Rothschild Summary., To increase the safety of antihaemophilic treatment, the production process of full-length recombinant factor VIII (FVIII) KOGENATE® Bayer (Kogenate®FS)has been modified. Human albumin is no longer added as stabilizer during purification and in final formulation. Instead, the new KOGENATE® Bayer production process uses sucrose as a stabilizer in the formulation and adds solvent/detergent virus inactivation step. An European clinical trial was carried out in Germany and France in previously treated patients with severe haemophilia A who had more than 100 exposure days to exogenous FVIII. Pharmacokinetic data was analysed according to one-stage and chromogenic assays. Efficacy and safety during home therapy and in surgical procedures were evaluated; inhibitor formation was carefully monitored. Safety and efficacy were evaluated in 33 European patients for 24 months. Patients received more than 13 million IU KOGENATE® Bayer. Over 75% of patients accrued more than 100 exposure days with the new product. Of 875 bleeding episodes, 90.7% were treated with 1 or 2 infusions and 75.8% of responses to treatment were rated as ,excellent' or ,good'. Prophylactic treatment was the most common mode of therapy (60.7% of infusions). The product was well-tolerated and FVIII recovery studies were consistent throughout the study period. Only 0.26% of adverse events were reported to be drug related. No evidence of de novo inhibitor formation was observed. Overall, KOGENATE® Bayer was efficacious, safe and well-tolerated for the treatment of haemophilia A in multitransfused patients. [source] Celecoxib as an adjunct in the treatment of depressive or mixed episodes of bipolar disorder: a double-blind, randomized, placebo-controlled study,,HUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 2 2008Fabiano G. Nery Abstract Objective To investigate whether the cox-2 inhibitor celecoxib has antidepressant effects in bipolar disorder (BD) patients during depressive or mixed phases. Methods We studied 28 DSM-IV BD patients who were experiencing a depressive or mixed episode and were on a stable dose of a mood stabilizer or atypical antipsychotic medication. Subjects were randomized to receive 6 weeks of double-blind placebo or celecoxib (400,mg/day) treatment. Current mood stabilizer or antipsychotic medication remained at the same doses during the trial. Results Intention-to-treat analysis showed that the patients receiving celecoxib had lower Hamilton Depression Rating Scale (HamD) scores after 1 week of treatment compared to the patients receiving placebo, but this difference was not statistically significant (p,=,0.09). The improvement in the first week of treatment was statistically significant when the analysis included only the subjects who completed the full 6-week trial (p,=,0.03). The two groups did not differ significantly on depressive or manic symptoms from the second week until the end of the trial. Celecoxib was well tolerated with the exception of two subjects who dropped out of the study due to rash. Conclusions Our findings suggest that adjunctive treatment with celecoxib may produce a rapid-onset antidepressant effect in BD patients experiencing depressive or mixed episodes. Copyright © 2008 John Wiley & Sons, Ltd. [source] Effect of risperidone on plasma catecholamine metabolites and brain-derived neurotrophic factor in patients with bipolar disordersHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 7 2006Reiji Yoshimura Abstract A combination treatment with a mood stabilizer and an antipsychotic drug is often used in as many as 90% of subjects with acute mania. Recently, augmentation therapy with atypical antipsychotics has been investigated in both the acute and long-term treatment of bipolar disorder with or without psychosis. In the present study, the authors investigated the efficacy of risperidone treatment for both acute manic and depressive episodes in bipolar disorder. Eighteen patients (M/F: 8/10, age: 34,±,15,yr) who met the DSM-IV criteria for bipolar I disorder (12 cases of manic episodes, 6 cases of depressive episodes) with risperidone treatment were evaluated regarding their clinical improvement using the Young Mania rating Scale (YMRS) and the Hamilton rating Scale for Depression (Ham-D). Plasma concentrations of HVA and MHPG were analyzed by HPLC-ECD and plasma brain-derived neurotrophic factor (BDNF) levels were detected by sandwich ELISA. The mean scores of the YMRS were 22, 18, 12, 8, and 5 at time points before and 1, 2, 3, and 4 weeks after the risperidone administration, respectively. The mean scores of the Ham-D were 24, 25, 21, 21, and 19 at time points before and 1, 2, 3, and 4 weeks after the risperidone administration, respectively. The plasma levels of HVA and 3-methoxy-4-hydroxyphenylglycol (MHPG) were observed to have decreased 4 weeks after risperidone administration in manic patients. The levels did not change in depressive patients. The plasma levels of BDNF were decreased in depressive patients compared with manic patients or healthy controls. However, the administration of risperidone did not alter plasma BDNF levels. Copyright © 2006 John Wiley & Sons, Ltd. [source] Robust stabilization of a class of non-minimum-phase nonlinear systems in a generalized output feedback canonical formINTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 3 2009Jun Fu Abstract In this paper, a globally robust stabilizer for a class of uncertain non-minimum-phase nonlinear systems in generalized output feedback canonical form is designed. The system contains unknown parameters multiplied by output-dependent nonlinearities and output-dependent nonlinearities enter such a system both additively and multiplicatively. The proposed method relies on a recently developed novel parameter estimator and state observer design methodology together with a combination of backstepping and small-gain approach. Our design has three distinct features. First, the parameter estimator and state observer do not necessarily follow the classical certainty-equivalent principle any more. Second, the design treats unknown parameters and unmeasured states in a unified way. Third, the technique by combining standard backstepping and small-gain theorem ensures robustness with respect to dynamic uncertainties. Finally, two numerical examples are given to show that the proposed method is effective, and that it can be applied to more general systems that do not satisfy the cascading upper diagonal dominance conditions developed in recent papers, respectively. Copyright © 2008 John Wiley & Sons, Ltd. [source] On parameter estimation for excitation control of synchronous generatorsINTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 5 2004Martha Galaz Abstract This paper deals with the problem of identification of the network parameters and the desired equilibrium in applications of excitation control for synchronous generators. Our main contribution is the construction of a new non-linear identifier that provides asymptotically consistent estimates (with guaranteed transient bounds) of the line impedance and the equilibrium for the classical three-dimensional flux-decay model of a single generator connected to an infinite bus. This model is non-linear, and non-linearly parameterized, and the equilibria depend also non-linearly on the unknown parameters. The proposed estimator can be used, adopting a certainty equivalent approach, to make adaptive any power system stabilizer that relies on the knowledge of these parameters. The behaviour of the scheme is illustrated in two simulated case studies with the interconnection and damping assignment passivity-based controller recently proposed by the authors. Copyright © 2004 John Wiley & Sons, Ltd. [source] Air-Stable and Highly Active Dendritic Phosphine Oxide- Stabilized Palladium Nanoparticles: Preparation, Characterization and Applications in the Carbon-Carbon Bond Formation and Hydrogenation ReactionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2008Lei Wu Abstract Dendrimer-stabilized palladium nanoparticles were formed in the reduction of palldium bis(acetylacetonate) [Pd(acac)2] in the presence of phosphine dendrimer ligands using hydrogen in tetrahydrofuran. The resulting Pd nanoparticles were characterized by TEM, 31P,NMR and 31P MAS NMR. The results indicated that the dendritic phosphine ligands were oxidized to phosphine oxides. These dendrimer-stabilized Pd nanoparticles were demonstrated to be efficient catalysts for Suzuki and Stille coupling reactions and hydrogenations. The dendritic wedges served as a stabilizer for keeping the nanoparticles from aggregating, and as a vehicle for facilitating the separation and/or the recycling of the Pd catalyst. In the case of the Suzuki coupling reaction, these Pd nanoparticles exhibited high catalytic efficiency (TON up to 65,000) and air stability as compared with the commonly used homogeneous catalyst tetrakis(triphenylphosphine)palladium [Pd(PPh3)4]. In addition, the results obtained from the bulky dendritic substrate suggest that the Pd nanoparticles might act as reservoir of catalytically active species, and that the reaction is actually catalyzed by the soluble Pd(0) and/or Pd(II) species leached from the nanoparticle surface. [source] Fibre type composition of the human psoas major muscle with regard to the level of its originJOURNAL OF ANATOMY, Issue 6 2009Juraj Arbanas Abstract The aim of our study was to explore the fibre type composition of the human psoas major muscle at different levels of its origin, from the first lumbar to the fourth lumbar vertebra, and to compare the muscle fibre size and distribution of different fibre types between levels with respect to its complex postural and dynamic function. Muscle samples were collected from 15 young males (younger than 35 years). Serial transverse sections (5 ,m) of the samples were cut by cryomicrotome. Type I, IIA and IIX muscle fibres were typed using myosin heavy chain identification. The serial sections were analysed using a light microscope with a magnitude of 100×. The differences between measurements were evaluated using a repeated-measures anova and Scheffé test for post-hoc analysis. Our study showed that the human psoas major muscle was composed of type I, IIA and IIX muscle fibres. It had a predominance of type IIA muscle fibres, whereas type I muscle fibres had the largest cross-sectional area. Type IIX muscle fibres were present as a far smaller percentage and had the smallest cross-sectional area. Moreover, the fibre type composition of the psoas major muscle was different between levels of its origin starting from the first lumbar to the fourth lumbar vertebra. We conclude that the fibre type composition of the psoas major muscle indicated its dynamic and postural functions, which supports the fact that it is the main flexor of the hip joint (dynamic function) and stabilizer of the lumbar spine, sacroiliac and hip joints (postural function). The cranial part of the psoas major muscle has a primarily postural role, whereas the caudal part of the muscle has a dynamic role. [source] Mechanochemical preparation of a novel polymeric photostabilizer for poly(vinyl chloride)JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010Xiaofei Zhang Abstract The preparation of a novel polymeric photostabilizer was carried out via the vibromilling of poly(vinyl chloride) (PVC) powder, a reactive light stabilizer (r-LS), and a peroxide initiator in ball-containing jars with a planetary ball mill for a certain time. The effects of the initiator content, milling time, and temperature on the grafting ratio were studied with gravimetric analysis and intrinsic viscosity measurements. Fourier transform infrared and ultraviolet,visible spectra were used to investigate the structural development of the mixture of the r-LS and PVC during vibromilling. The results showed that the r-LS was grafted onto PVC chains successfully, and the aforementioned factors had a significant effect on the grafting ratio. The optimum preparation conditions were 0.5 wt % initiator, 8 h, and 20°C. A grafting mechanism is proposed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Thermal degradation behavior of poly(vinyl chloride) in the presence of poly(glycidyl methacrylate)JOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2008Magdy W. Sabaa Abstract The thermal degradation behavior of poly(vinyl chloride) (PVC) in presence of poly(glycidyl methacrylate) (PGMA) has been studied using continuous potentiometric determination of the evolved HCl gas from the degradation process from one hand and by evaluating the extent of discoloration of the degraded samples from the other. The efficiency of blending PGMA with dibasic lead carbonate (DBLC) conventional thermal stabilizer has also been investigated. A probable radical mechanism for the effect of PGMA on the thermal stabilization of PVC has been suggested based on data reported by FTIR and elemental analyses. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Studying and increasing light stability of rotomolding grade of polyethyleneJOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2008E. Feyz Abstract This article covers the state-of-the-art light stabilizer for rotational molding and the influence of synergistic effects between light and thermal stabilizers, which improve physical and mechanical properties. Different formulations of polyethylene (PE) with light stabilizer, thermal stabilizer, and acid scavenger have been produced in twin-screw extruder. To study the light stability, sheets that produced by injection-molding machine have been put in weather-ometer instrument for 1000 h. After and before that, physical and mechanical properties have been evaluated. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Effects of epoxidized sunflower oil on the mechanical and dynamical analysis of the plasticized poly(vinyl chloride)JOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2008Badra Bouchareb Abstract Epoxidized soybean oil (ESBO), is one of the most commonly used epoxides because of its typical combined roles as a plasticizer and heat stabilizer. In this study, a novel plasticizer of poly(vinyl chloride) (PVC) resins, epoxidized sunflower oil (ESO), was synthesized, and its performance was evaluated. ESO was designed to act as a coplasticizer and a heat stabilizer like ESBO. ESO is used as organic coplasticizer for plasticized PVC containing Ca and Zn stearates as primary stabilizers and stearic acid as lubricant. Di-(2-ethylhexyl) phthalate (DEHP), a conventional plasticizer for PVC, was partially replaced by ESO. Mechanical properties (tensile and shore D hardness) were investigated. The performance of ESO to ESB0 (20 g) for comparison, indicated that ESO could be used as secondary plasticizer for PVC in combination with DEHP. All mechanical and dynamical properties of plasticized PVC sheets varied with the oxirane oxygen of the ESO. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Dispersion polymerization of methyl methacrylate: Effect of stabilizer concentrationJOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2008Sheng Jiang Abstract In dispersion polymerizations of methyl methacrylate (MMA), little difference was found in the polymerization kinetics with varying stabilizer (PVP K-30) concentration, indicating that in contrast to emulsion polymerization, the kinetics of these dispersion polymerizations are independent of the number of particles. Comparing MMA precipitation and dispersion polymerizations revealed that nuclei formation in the latter results from precipitation polymerization occurring in the continuous phase, which can contribute significantly to the kinetics, and especially to the molecular weight distributions. No change was found in the molecular weight distribution of the PVP during a dispersion polymerization, nor was there any measurable difference between using fresh and recycled stabilizer. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Water-dispersible conducting polyaniline/nano-SiO2 composites without any stabilizerJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008Xingwei Li Abstract A water-dispersible conducting polyaniline/ nano-SiO2 composite, with a conductivity of 0.071 S cm,1 at 25°C, was prepared by the oxidative polymerization of aniline in the presence of amorphous nano-SiO2 particles. And the structure, morphology, thermal stability, conductivity, and electroactivity of this composite were also investigated. This composite has been steadily dispersed in the aqueous solution for about 10,36 h without the need for any stabilizer. It would significantly impulse the commercial applications of conducting polyaniline/nano-SiO2 composite as fillers for antistatic and anticorrosion coatings. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Thyroid hormone-mediated growth and differentiation of growth plate chondrocytes involves IGF-1 modulation of ,-catenin signalingJOURNAL OF BONE AND MINERAL RESEARCH, Issue 5 2010Lai Wang Abstract Thyroid hormone regulates terminal differentiation of growth plate chondrocytes in part through modulation of the Wnt/,-catenin signaling pathway. Insulin-like growth factor 1 (IGF-1) has been described as a stabilizer of ,-catenin, and thyroid hormone is a known stimulator of IGF-1 receptor expression. The purpose of this study was to test the hypothesis that IGF-1 signaling is involved in the interaction between the thyroid hormone and the Wnt/,-catenin signaling pathways in regulating growth plate chondrocyte proliferation and differentiation. The results show that IGF-1 and the IGF- receptor (IGF1R) stimulate Wnt-4 expression and ,-catenin activation in growth plate chondrocytes. The positive effects of IGF-1/IGF1R on chondrocyte proliferation and terminal differentiation are partially inhibited by the Wnt antagonists sFRP3 and Dkk1. T3 activates IGF-1/IGF1R signaling and IGF-1-dependent PI3K/Akt/GSK-3, signaling in growth plate chondrocytes undergoing proliferation and differentiation to prehypertrophy. T3 -mediated Wnt-4 expression, ,-catenin activation, cell proliferation, and terminal differentiation of growth plate chondrocytes are partially prevented by the IGF1R inhibitor picropodophyllin as well as by the PI3K/Akt signaling inhibitors LY294002 and Akti1/2. These data indicate that the interactions between thyroid hormone and ,-catenin signaling in regulating growth plate chondrocyte proliferation and terminal differentiation are modulated by IGF-1/IGF1R signaling through both the Wnt and PI3K/Akt signaling pathways. While chondrocyte proliferation may be triggered by the IGF-1/IGF1R-mediated PI3K/Akt/GSK3, pathway, cell hypertrophy is likely due to activation of Wnt/,-catenin signaling, which is at least in part initiated by IGF-1 signaling or the IGF-1-activated PI3K/Akt signaling pathway. © 2010 American Society for Bone and Mineral Research [source] Cepharanthine activates caspases and induces apoptosis in Jurkat and K562 human leukemia cell linesJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2001Jianghong Wu Abstract Cepharanthine (CEP) is a known membrane stabilizer that has been widely used in Japan for the treatment of several disorders such as anticancer therapy-provoked leukopenia. We here report that apoptosis was induced by low concentrations (1,5 ,M) of CEP in a human leukemia T cell line, Jurkat, and by slightly higher concentrations (5,10 ,M) in a human chronic myelogenous leukemia (CML) cell line K562, which expresses a p210 antiapoptotic Bcr-Abl fusion protein. Induction of apoptosis was confirmed in both Jurkat and K562 cells by DNA fragmentation and typical apoptotic nuclear change, which were preceded by disruption of mitochondrial membrane potential and were induced through a Fas-independent pathway. CEP treatment induced activation of caspase-9 and -3 accompanied by cleavage of PARP, Bid, lamin B1, and DFF45/ICAD in both Jurkat and K562 cells, whereas caspase-8 activation and Akt cleavage were observed only in Jurkat cells. The CEP-induced apoptosis was completely blocked by zVAD-fmk, a broad caspase inhibitor. Interestingly, CEP treatment induced remarkable degradation of the Bcr-Abl protein in K562 cells, and this degradation was prevented partially by zVAD-fmk. When used in combination with a nontoxic concentration of herbimycin A, lower concentrations (2,5 ,M) of CEP induced obvious apoptosis in K562 cells with rapid degradation or decrease in the amount of Bcr-Abl and Akt proteins. Our results suggest that CEP, which does not have bone marrow toxicity, may possess therapeutic potential against human leukemias, including CML, which is resistant to anticancer drugs and radiotherapy. J. Cell. Biochem. 82: 200,214, 2001. © 2001 Wiley-Liss, Inc. [source] Magnebike: A magnetic wheeled robot with high mobility for inspecting complex-shaped structuresJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 5 2009Fabien Tâche This paper describes the Magnebike robot, a compact robot with two magnetic wheels in a motorbike arrangement, which is intended for inspecting the inner casing of ferromagnetic pipes with complex-shaped structures. The locomotion concept is based on an adapted magnetic wheel unit integrating two lateral lever arms. These arms allow for slight lifting off the wheel in order to locally decrease the magnetic attraction force when passing concave edges, as well as laterally stabilizing the wheel unit. The robot has the main advantage of being compact (180 × 130 × 220 mm) and mechanically simple: it features only five active degrees of freedom (two driven wheels each equipped with an active lifter stabilizer and one steering unit). The paper presents in detail design and implementation issues that are specific to magnetic wheeled robots. Low-level control functionalities are addressed because they are necessary to control the active system. The paper also focuses on characterizing and analyzing the implemented robot. The high mobility is shown through experimental results: the robot not only can climb vertical walls and follow circumferential paths inside pipe structures but it is also able to pass complex combinations of 90-deg convex and concave ferromagnetic obstacles with almost any inclination regarding gravity. It requires only limited space to maneuver because turning on the spot around the rear wheel is possible. This high mobility enables the robot to access any location in the specified environment. Finally the paper analyzes the maximum payload for different types of environment complexities because this is a key feature for climbing robots and provides a security factor about the risk of falling and slipping. © 2009 Wiley Periodicals, Inc. [source] IMPROVING THE QUALITY AND SHELF LIFE OF TURKISH ALMOND PASTEJOURNAL OF FOOD QUALITY, Issue 4 2008ESRA CAPANOGLU ABSTRACT Almond paste is an economically valuable product produced from almonds, sugar and a small amount of water. Oxidative rancidity and oil separation are the major problems that are encountered in the paste products affecting the shelf life. Another problem appears to be drying on the surface of the product resulting in poor consumer acceptability. In this study, the formulation of product was altered by adding a commercial stabilizer, antioxidant mixture and maltose syrup to prevent undesirable quality changes during storage at 4C and 30C. Peroxide value, free fatty acid and Rancimat analysis showed that the addition of antioxidant mixture prevented oxidation effectively and improved sensory scores significantly (P , 0.05). Although stabilizer addition had a detrimental effect on the textural properties, samples that have maltose had high sensory scores. The results showed that incorporation of maltose syrup and antioxidant may improve the texture and shelf life of almond paste. PRACTICAL APPLICATIONS The available literature on almond paste is mainly focused on the microbiological quality of the product and the prevention of spoilage reactions by modifying packaging materials. However, there is no report on the optimization of the composition to extend the shelf life of almond paste. Turkish almond paste, a healthy and expensive dessert, is a specialty product that is manufactured by using traditional grinding equipment. However, the limited shelf life of this product decreases its export potential resulting in economical losses. Therefore, improved shelf life and quality of the product is of importance from the economical point of view. In our study, we aimed to improve the quality and shelf life of Turkish almond paste by modifying its formulation in order to minimize the undesirable changes that occur during storage. [source] EFFECT OF FLAXSEED GUM ON QUALITY AND STABILITY OF A MODEL SALAD DRESSING,JOURNAL OF FOOD QUALITY, Issue 4 2000S. STEWART ABSTRACT Flaxseed gum was evaluated for its application as a stabilizer for salad dressing. It was found that for stabilization to occur the concentration of gum had to be higher than 0.45% (w/w). Solvent quality affected the stability of model oil-in-water emulsions. Flaxseed gum stabilized emulsions were stable at pHs greater than 2.8. Lower values caused the polysaccharide to have a compact configuration or caused cleavage of the polymer creating instability. Larger mean droplet size and creaming were observed when the pH was too low or the gum concentration was not sufficient for coverage. Salt addition greatly affected the rheological properties of the polysaccharide; however, the electrolyte improved the emulsifying capabilities of the egg yolk protein. Aging weakened the polymer network structure as shown by a decrease in Newtonian viscosity with a corresponding increase in phase angle confirming the transformation to a more fluid system. [source] Frozen Wild Blueberry-Tofu-Soymilk DessertsJOURNAL OF FOOD SCIENCE, Issue 2 2006Mary Ellen Camire ABSTRACT Both wild (lowbush) blueberries (Vaccinium angustifolium Ait.) and soybeans (Glycine max L.) possess a variety of antioxidants, and both foods appear to have multiple health benefits. Our objectives were to identify whether wild blueberry juice concentrate was more acceptable than puree in frozen desserts with a soy milk-tofu base; to determine whether fat-free products were as acceptable as those with 10% added fat; and to compare several levels of blueberry juice concentrate. Four frozen dessert formulations were prepared in duplicate from soy milk, silken tofu, sucrose, stabilizer, BJC or puree, soybean oil or polydextrose, sweetened dried blueberries, salt, and lemon juice. Samples were assayed for total anthocyanins, antioxidant activity using the DPPH method, color, overrun, and solids. Fifty-five persons evaluated the samples using a 9-point hedonic scale for color, flavor, texture, and overall acceptability. Samples containing blueberry juice concentrate were darker and less blue. Anthocyanin levels were highest in the puree sample and the fat-free product with 7.8% blueberry juice concentrate. However, antioxidant activity was highest (28 Trolox equivalents per gram) in the samples made with soybean oil and 7.4% blueberry juice concentrate. The puree formulation received higher hedonic scores than did the low-fat blueberry juice concentrate formulations. The puree formulation received overall acceptability scores of like very much or like extremely by 45% of the consumers. These findings may aid processors in defining potential formulations that combine 2 healthful food ingredients. [source] Improved Correlation Between Sensory and Instrumental Measurement of Peanut Butter TextureJOURNAL OF FOOD SCIENCE, Issue 5 2002C.M. Lee And Two commercial peanut butters and 3 laboratory-prepared peanut butters containing 0.5, 1.5 and 2.5% stabilizer were evaluated by sensory and instrumental texture profile analysis (TPA) using an Instron. A 2×3 factorial design consisting of crosshead speeds of 5 and 50 mm/min, and amount and type of fluid added was used. A descriptive panel (n= 11) was used to evaluate 14 sensory TPA attributes. Twelve sensory TPA attributes, compared with only 2 found by other researchers, were highly correlated ( 0.88) with 1 or more instrumental TPA parameters. Prediction models (R 0.71) developed successfully predicted 12 sensory texture attributes from instrumental TPA results. Eleven models, excluding surface roughness, were successfully verified with 0.74 to 7.21% error. [source] | |||||||||||||||||||||||||||||||||||||||||||