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Paste
Kinds of Paste Terms modified by Paste Selected AbstractsPHYSICO-CHEMICAL AND STORAGE CHARACTERISTICS OF GARLIC PASTEJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2001JASIM AHMED A processed paste with a total solids and pH value of 33% and 4.1, respectively was prepared from fresh garlic by addition of 10% sodium chloride (w/w) and citric acid. Appearance of green pigment (in terms of the Hunter color -a* value) was noticed in the product during preparation. Paste was thermally processed at 70, 80 or 90C, respectively for 15 min. Greening of paste decreased with increase in temperature. Rheological data revealed that garlic paste behaved as a psuedo-plastic fluid with a flow behavior and consistency index of 0.14 and 279 Pa.sn, respectively. The paste was analyzed periodically for color and microbiological counts. The product was found to be shelf stable at 25C for a period of at least 6 months. The green coloration decreased significantly (p<0.05) during storage. [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] QUALITY AND CONSUMER ACCEPTANCE OF AKARA (FRIED COWPEA PASTE) PROCESSED FROM WET- AND DRY-MILLED COWPEA (VIGNA UNGUICULATA) MEAL WITH SPECIFIED PARTICLE SIZE DISTRIBUTIONJOURNAL OF FOOD QUALITY, Issue 3 2007MELISSA A. VANCHINA ABSTRACT Direct quality indicators of cowpea paste and akara produced from traditionally wet-milled peas, and hammer-milled (dry-milled) and freeze-dried (wet-milled) meals were examined in this study. Both meal samples studied were formulated to consist of 65% medium-sized particles and 35% large particles by weight. Particle volume mean diameters (µm) of the three paste samples were not significantly different from one another at the various stages during akara production. Scanning electron micrographs of akara crumb were converted to threshold images and analyzed. There was no significant difference in the amount of air found in the akara samples. Akara produced from both meals was found acceptable by sensory panelists with no significant difference in any of the attributes or overall liking among the three samples. [source] INFLUENCE OF HAZELNUT PASTE ON THE SENSORY PROPERTIES AND SHELF-LIFE OF DARK CHOCOLATEJOURNAL OF SENSORY STUDIES, Issue 2 2004L.A. NATTRESS ABSTRACT The addition of hazelnut paste to dark chocolate formulations altered the sensory profile. The flavors chocolate, burnt, rancid, hazelnut, green and metallic, and the texture attributes hardness, graininess, consistency of melt, viscosity and onset of melt determined by descriptive analysis were significantly (P < 0.05) influenced by the addition of up to 10% hazelnut paste. The shelf-life of dark chocolates containing hazelnut exceeded 10 months. The textural attributes of hardness, consistency of melt and onset of melt were highly correlated to instrumental measurements. [source] CHANGES IN TOMATO PASTE DURING STORAGE AND THE EFFECTS OF HEATING ON CONSISTENCY OF RECONSTITUTED TOMATO PASTEJOURNAL OF TEXTURE STUDIES, Issue 3 2010GORDON E. ANTHON ABSTRACT Bostwick consistencies of reconstituted tomato pastes were measured both immediately after paste production and after storage times of up to 9 months. Bostwick values measured after storage were more than twice those measured on the day of paste production. This increase in Bostwick developed over the first month of paste storage at room temperature and could be slowed down but not prevented if the paste was stored at 4C. Heating the reconstituted paste for 30 min at 90C or 15 min at 100C restored the original consistency. Serum viscosities also decreased during paste storage, but the change in serum viscosity was smaller than the changes in Bostwick. As with the Bostwick, heating the reconstituted juice restored the serum viscosity. For a reproducible evaluation of the consistency of stored tomato paste, it is essential that the reconstituted paste be heated to 90C or above. PRACTICAL APPLICATIONS Consistency is an important quality consideration in products prepared from reconstituted tomato paste. During storage, changes occur in tomato paste, which affect the consistency after reconstitution. The results presented here show that for stored tomato paste, heating after reconstitution restores consistency to the same level as measured before storage. This knowledge will help in the formulation of products made from stored tomato paste. [source] RHEOLOGICAL PROPERTIES OF HOT PEPPER-SOYBEAN PASTEJOURNAL OF TEXTURE STUDIES, Issue 4 2001B. YOO Rheological properties of fermented hot pepper-soybean paste (HPSP) were evaluated at different total solid contents (TS, 43.6-54.7%) and temperatures (10-40C). HPSP samples at 20C are highly shear thinning fluids (n=0.25-0.33) with large magnitudes of Casson yield stresses (106-573 Pa). Consistency index (K) and apparent viscosity (,a,20) increased with increase in TS. Apparent viscosity of HPSP obeyed the Arrhenius temperature relationship. The magnitudes of activation energy (7.6-20.4 kJ/mole) for HPSP increased with increase in TS. A single equation, combining the effects of temperature and concentration on ,a,20, was used to describe flow behavior of HPSP. The time-dependent model of Weltman was found to be most applicable (R2= 0.97-0.99) for HPSP. Storage (G') and loss (G") moduli increased with increase in TS, while complex viscosity (,*) decreased. Magnitudes of G'were higher than those of G" over the entire range of frequencies (,). [source] A New Type of Bismuth Electrode for Electrochemical Stripping Analysis Based on the Ammonium Tetrafluorobismuthate Bulk-Modified Carbon PasteELECTROANALYSIS, Issue 13 2010Hanna Sopha Abstract A carbon paste electrode bulk-modified with ammonium tetrafluorobismuthate (BiF4 -CPE) was developed and examined in the anodic stripping voltammetric mode for measurement of selected trace heavy metals. The BiF4 -CPE has revealed a favorable performance in more acidic solutions (pH,0.5,2.5) in the presence of dissolved oxygen for Cd(II) and Pb(II) as model metal ions at the low ,g L,1 concentration level. In comparison with the bismuth-oxide bulk-modified carbon paste electrode and the other two bismuth film-plated carbonaceous substrate electrodes examined, the BiF4 -CPE proved to be another attractive variant of the environmentally friendly bismuth-based electrodes, particularly convenient for analysis of acidified water samples. [source] Working Electrodes from Amalgam Paste for Electrochemical MeasurementsELECTROANALYSIS, Issue 4 2008Bogdan Yosypchuk Abstract Paste electrode with paste amalgam as an active electrode material is described here for the first time. Designed electrode from silver paste amalgam (AgA-PE) is solely metallic and does not contain any organic binder. Mechanical surface regeneration of AgA-PE is performed in the same way as for classical carbon paste electrodes and reproducibility of such regeneration is about 10%. Electrochemical surface regeneration appeared very efficient for most measurements. In dependence on paste metal content, the electrode surface can be liquid (resembling a film) or rather solid. The hydrogen overvoltage on AgA-PE is high, and the electrode allows measurements at highly negative potentials. AgA-PE is well suited for study of reduction or oxidation processes without an accumulation step. Anodic stripping voltammetry of some metals tested on the electrode is influenced by formation of intermetallic compounds. The measurement based on cathodic stripping voltammetry (adenine, cysteine) and on catalytic processes from adsorbed state (complex of osmium tetroxide with 2,2,-bipyridine) can be performed on AgA-PE practically under the same conditions as found earlier for HMDE and for silver solid amalgam electrode. The working electrode from paste amalgam combines the advantages of paste and metal electrodes. [source] Near Zero Shrinkage of an Low-Temperature Co-Fired Ceramic Package by Constrained Sintering Using Screen Printed Alumina PasteINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 2010Sang Myoung Lee Conventional free sintering of low-temperature co-firing ceramic (LTCC) technology has several merits such as sintering temperature below 1000°C that enables co-firing with electrode materials of silver or copper metal and multilayer structure formation. But due to the free sintering process, large shrinkage occurs. To fabricate electronic devices and components with near zero shrinkage within x, y directions constrained sintering (CS) technology is required. In this study a constrained sintering paste (CSP) utilizing alumina powder, which has a higher sintering temperature than LTCC powders, was fabricated for CS technology. The effect of CSP formulated using alumina powder on shrinkage was studied according to variation in paste composition. As a result ceramic package structure with a cavity was fabricated with shrinkage control of 0.028%, which is far smaller than the current CS technology shrinkage of approximately 0.1%. [source] PHYSICO-CHEMICAL AND STORAGE CHARACTERISTICS OF GARLIC PASTEJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2001JASIM AHMED A processed paste with a total solids and pH value of 33% and 4.1, respectively was prepared from fresh garlic by addition of 10% sodium chloride (w/w) and citric acid. Appearance of green pigment (in terms of the Hunter color -a* value) was noticed in the product during preparation. Paste was thermally processed at 70, 80 or 90C, respectively for 15 min. Greening of paste decreased with increase in temperature. Rheological data revealed that garlic paste behaved as a psuedo-plastic fluid with a flow behavior and consistency index of 0.14 and 279 Pa.sn, respectively. The paste was analyzed periodically for color and microbiological counts. The product was found to be shelf stable at 25C for a period of at least 6 months. The green coloration decreased significantly (p<0.05) during storage. [source] Evaluation of Antioxidant Effects of Raisin Paste in Cooked Ground Beef, Pork, and ChickenJOURNAL OF FOOD SCIENCE, Issue 4 2006M.N. Vasavada ABSTRACT:, The objective of this study was to evaluate the possible antioxidant activity of raisin paste added to raw ground beef, pork, or chicken before cooking to 163 °C. Samples were held at 2 °C for up to 14 d. TBA values were measured using a distillation method, to avoid yellow color interference found in "wet" TBA methods. Sample meat flavor intensity, rancid flavor intensity, and raisin flavor intensity were evaluated by a trained panel (n = 6). Addition of raisin paste lowered (p < 0.05) TBA values and decreased panel scores for rancid flavor scores of all meat samples in a concentration-dependent manner. Highest antioxidant effects were obtained with a minimum of 1.5%, 2.0%, or 2.0% raisin paste in cooked ground beef, pork, or chicken, respectively. There was a high correlation (0.93, 0.94, 0.94) between TBA values and sensory rancid flavor scores in beef, pork, and chicken samples respectively. Addition of a reducing sugar (glucose) was nearly as effective as raisins for maintenance of low TBA values and rancid flavor scores, probably due to antioxidant effects of Maillard browning products. There was no detectable raisin flavor in cooked ground beef samples with added raisins. However, all meats with added glucose had a higher raisin flavor intensity score than controls, indicating that panelists associated sweetness with raisin flavor. Maillard browning (sample darkening) was evident after cooking of ground chicken with either raisins or glucose. [source] Irradiation Effects on Biogenic Amines in Korean Fermented Soybean Paste During FermentationJOURNAL OF FOOD SCIENCE, Issue 1 2003J.-H. Kim ABSTRACT: Irradiation effects on biogenic amines (BAs) and microbiological populations of Korean fermented soybean paste were investigated during fermentation. Soybean paste was prepared and irradiated with doses of 5,10, and 15 kGy, and then fermented at 25 °C for 12 wk. Bacillus spp. and lactic-acid bacteria decreased by irradiation but increased during fermentation. Biogenic amines detected were putrescine, cadaverine, ,-phenylethylamine, spermidine, spermine, tryptamine, histamine, tyramine, and agmatine. A significant difference was not observed in BA content between control and irradiated samples immediately after gamma irradiation. However, 4 kinds of BAs, putrescine, tryptamine, spermidine, and histamine, showed significant reduction by irradiation during fermentation (P < 0.05). [source] Constrained Sintering of Silver Circuit PasteJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 2 2004Yun-Chiang Lin Densification kinetics and stress development during constrained sintering of a silver film on a rigid silicon substrate have been studied. Compared with free sintering, the sintering of constrained silver film exhibits a much lower densification and slower densification kinetics. The densification-controlled mechanism changes from fast grain-boundary diffusion kinetics for free sintering to slow lattice diffusion kinetics for constrained sintering. The in-plane tensile stress developed during constrained sintering of silver film, measured using a noncontact laser-scanning optical system, increases rapidly to a maximum level of 1.0,1.5 MPa initially, gradually decreases, and then becomes constant at 0.8,1.0 MPa. The maximum stress observed increases with increasing sintering temperature as a result of the faster densification rate. It is believed that the retardation of densification kinetics of constrained silver film is caused by a change in densification mechanism and the existence of in-plane tensile stress. [source] Effect of Heat Treatment on the Pore Structure and Drying Shrinkage Behavior of Hydrated Cement PasteJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 9 2002Jeffrey J. Thomas The effect of a short heat treatment on hydrated cement paste has been investigated by measuring the weight and length changes of specimens as they undergo various combinations of heating, drying, and resaturation. Heating a cement paste to 60°C coarsens the capillary pore system, decreases the volume of mesopores, and increases the degree of polymerization of the silicates. In addition, the saturated weight of the paste is permanently decreased by a heat treatment. This weight loss can be explained by conversion of bound hydroxyl groups into liquid water during polymerization of the C-S-H gel phase. These experiments help reconcile and interpret published results describing the properties of cement cured at various temperatures, the effects of a short heat treatment on cement paste, and the thermal expansion behavior of saturated and dry cement paste. [source] Modelling of paste flows subject to liquid phase migrationINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 10 2007M. J. Patel Abstract Particulate pastes undergoing extrusion can exhibit differential velocities between the solid and liquid phases, termed liquid phase migration (LPM). This is observed experimentally but understanding and predictive capacity for paste and extruder design is limited. Most models for LPM feature one-dimensional analyses. Here, a two-dimensional finite element model based on soil mechanics approaches (modified Cam-Clay) was developed where the liquid and the solids skeleton are treated separately. Adaptive remeshing routines were developed to overcome the significant mesh distortion arising from the large strains inherent in extrusion. Material data to evaluate the model's behaviour were taken from the literature. The predictive capacity of the model is evaluated for different ram velocities and die entry angles (smooth walls). Results are compared with experimental findings in the literature and good qualitative agreement is found. Key results are plots of pressure contributions and extrudate liquid fraction against ram displacement, and maps of permeability, liquid velocity and voids ratio. Pore liquid pressure always dominates extrusion pressure. The relationship between extrusion geometry, ram speed and LPM is complex. Overall, for a given geometry, higher ram speeds give less migration. Pastes flowing into conical entry dies give different voids ratio distributions and do not feature static zones. Copyright © 2007 John Wiley & Sons, Ltd. [source] Drying and Rewetting of Mature Cement Pastes Studied through Positron Annihilation Lifetime SpectroscopyJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2001Giovanni Consolati Positron annihilation lifetime measurements have been conducted on mature cement pastes, subjected to drying and rewetting treatments that remove and restore the free water from the pastes, to study possible changes of the microstructure. Analysis of the results suggests that repeated drying followed by rewetting does not induce irreversible modifications in the configuration of the finest gel pores. [source] Screen-print selective diffusions for high-efficiency industrial silicon solar cellsPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 1 2008Matthew Edwards Abstract Screen-print diffusion pastes present an industrially applicable alternative to conventional techniques of dopant deposition. Several commercially available screen-print dopant pastes are assessed for their suitability in forming heavy selective diffusions for use under metal contacts in silicon solar cells. Pastes are assessed in terms of their ease of application, their ability to form heavy diffusions with low sheet resistances, and their ability to maintain high post-diffusion wafer lifetimes. Potential for the use of dopant pastes in high-efficiency solar cell devices is investigated using photoconductance (PC) measurements and photoluminescence (PL) images. It is found that under certain conditions, screen-print dopant pastes, particularly phosphorus paste, have potential to form effective selective diffusions without significantly compromising performance in high-efficiency solar cells. Copyright © 2007 John Wiley & Sons, Ltd. [source] Buchbesprechung: Rheometry of Pastes, Suspensions, and Granular Materials.CHEMIE-INGENIEUR-TECHNIK (CIT), Issue 6 2007Von P. Coussot. No abstract is available for this article. [source] Biocompatibility evaluation of alendronate paste in rat's subcutaneous tissueDENTAL TRAUMATOLOGY, Issue 2 2009Graziela Garrido Mori Therefore, this study aimed to investigate the biocompatibility of experimental alendronate paste in subcutaneous tissue of rats, for utilization in teeth susceptible to root resorption. The study was conducted on 15 male rats, weighing ,180,200 grams. The rats' dorsal regions were submitted to one incision on the median region and, laterally to the incision, the subcutaneous tissue was raised and gently dissected for introduction of two tubes, in each rat. The tubes were sealed at one end with gutta-percha and taken as control. The tubes were filled with experimental alendronate paste. The animals were killed at 7, 15 and 45 days after surgery and the specimens were processed in laboratory. The histological sections were stained with hematoxylin-eosin and analyzed by light microscopy. Scores were assigned to the inflammatory process and statistically compared by the Tukey test (P < 0.05). Alendronate paste promoted severe inflammation process at 7 days, with statistically significant difference compared to the control (P < 0.05%). However, at 15 days, there was a regression of inflammation and the presence of connective tissue with collagen fibers, fibroblasts and blood vessels was observed. After 45 days, it was observed the presence of well-organized connective tissue, with collagen fibers and fibroblasts, and few inflammatory cells. No statistical difference was observed between the control and experimental paste at 15 and 45 days. The experimental alendronate paste was considered biocompatible with subcutaneous tissue of rat. [source] Effect of root surface treatment with propolis and fluoride in delayed tooth replantation in ratsDENTAL TRAUMATOLOGY, Issue 6 2008Jéssica Lemos Gulinelli Nevertheless, an extended extraoral period damages the periodontal ligament and results in external root resorption. The purpose of this study was to assess by histologic and histometric analysis, the influence of propolis 15% (natural resinous substance collected by Apis mellifera bees from various plants) and the fluoride solution used as root surface treatment on the healing process after delayed tooth replantation. Thirty Wistar (Rattus norvegicus albinus) rats were submitted to extraction of their upper right incisor. The teeth were maintained in a dry environment for 60 min. After this, the pulp was extirpated and the papilla, enamel organ and periodontal ligament were removed with scalpel. The teeth were divided into three experimental groups: Group I , teeth immersed in 20 ml of physiologic saline; Group II , teeth immersed in 20 ml of 2% acidulated phosphate sodium fluoride; Group III , teeth immersed in 20 ml of 15% propolis. After 10 min of immersion in the solutions, the root canals were dried and filled with calcium hydroxide paste and the teeth were replanted. The animals were euthanized 60 days after replantation. The results showed that similar external root resorption was seen in the propolis and fluoride groups. Teeth treated with physiologic saline tended to have more inflammatory root resorption compared with those treated with fluoride or propolis. However, the comparative analysis did not reveal statistically significant differences (P > 0.05) between the treatment modalities when used for delayed tooth replantation. [source] Comparison of acidic fibroblast growth factor on collagen carrier with calcium hydroxide as pulp capping agents in monkeysDENTAL TRAUMATOLOGY, Issue 5 2007Zhimei Li Abstract,,, Acidic fibroblast growth factor (aFGF) has been shown to facilitate wound healing by stimulating fibroblast proliferation and angiogenesis. It has also been reported to possess a powerful anti-apoptotic function This study compared the histological pulp responses to aFGF on collagen carrier and Ca(OH)2 placed on the mechanically exposed dental pulp in monkeys at two observation periods. Thirty-six teeth with pulp exposures were distributed into three groups according to the capping agents used prior to application of the coronal seal: collagen-based matrix carrier (group 1), aFGF on the collagen-based matrix carrier (group 2) and aqueous calcium hydroxide [Ca(OH)2] paste (group 3). Specimens were harvested at 6 and 13 weeks postoperatively and prepared for hematoxylin and eosin, and Gram staining. Histological qualitative evaluation of pulp responses were performed under the light microscope following criteria modified from Cox et al. (17) and Hu et al. (18). Semi-quantitative analysis was also carried out using Kruskal,Wallis and Mann,Whitney U -tests. There was neither negligible inflammatory infiltrates with no bacteria present in the three groups at both timings, nor was there any significant difference in the soft tissue organization among the three groups at or between the 6- and 13-week observation periods. At 6 weeks, the hard tissue barrier produced by Ca(OH)2 group (1.040 ± 0.089) was significantly more superior than aFGF/collagen carrier group (1.930 ± 0.825) (P = 0.030) as well as collagen carrier group (3.142 ± 1.069, P = 0.018). At 13 weeks, both aFGF/collagen carrier group (1.214 ± 0.485) and the collagen carrier group (1.457 ± 0.814) produced significantly better hard tissue barrier (P = 0.040 and P = 0.017, respectively) than earlier timing. However, these two groups did not induce significantly improved hard tissue barrier compared to that produced by aqueous Ca(OH)2 paste which stimulated matrix secretion in a polar tubular dentin-like pattern. [source] Reattachment of subgingivally fractured central incisor with an open apexDENTAL TRAUMATOLOGY, Issue 3 2007Ece Eden Abstract,,, A case report of a 6-year-old girl with a fractured maxillary left central incisor with an open apex is presented. The procedure used to repair the fracture included flap surgery with an intrasulcular incision and endodontic treatment. The patient was called for 3 months regular follow-up to check the root formation. At the end of 32 months just before the root was obturated by guttaperka, she fractured the same tooth. Flap surgery was repeated and the tooth was restored. The root canal was obturated with a root filling paste and guttaperka as the apex was closed. Examination 10 months after treatment revealed good periodontal health, aesthetics and normal function. [source] Sealing evaluation of the cervical base in intracoronal bleachingDENTAL TRAUMATOLOGY, Issue 6 2003Luciane Dias De Oliveira Abstract,,, Discoloration of non-vital teeth is an esthetic deficiency frequently requiring bleaching treatment. The purpose of this study was to evaluate in vitro the cervical base efficacy in order to prevent or to minimize the leakage along the root canal filling and into the dentinal tubules. Thirty-eight extracted single-root human teeth were used, which were biomechanically prepared, filled, and divided into three experimental groups: G1, a cervical base was applied (3 mm of thickness) below the cemento-enamel junction, with resin-modified glass-ionomer cement (Vitremer); G2, the base was done with glass-ionomer cement (Vidrion R); and G3 (Control), did not receive any material as base. A mixture of sodium perborate and hydrogen peroxide 30% was placed inside the pulp chamber for 3 days, and the access opening was sealed with Cimpat. This procedure was repeated thrice. Soon after this, a paste of calcium hydroxide was inserted into the pulp chamber for 14 days. All teeth were covered with two layers of sticky wax, except the access opening, and immersed in blue India Ink for 5 days. The results did not show statistically significant differences between the three groups concerning the leakage inside the dentinal tubules. Regarding the apical direction, a statistical difference (anovaP < 0.05) was observed among the experimental group G1 and control group G3. No statistically significant difference was observed between G2 and G3 groups. Therefore, the placement of a cervical base before internal bleaching procedures is still recommended. [source] Periodontal response to two intracanal medicaments in replanted monkey incisorsDENTAL TRAUMATOLOGY, Issue 6 2001Y. L. Thong Abstract , Intracanal medicaments are recommended for use in replanted teeth to inhibit inflammatory root resorption. This study compared the effect of calcium hydroxide (Pulpdent®) and a corticosteroid-antibiotic paste (Ledermix®) on periodontal healing and root resorption following replantation. Incisors of eight Macaca fascicularis monkeys were extracted, stored dry for 15 min and replanted. After 11 days, root canals in two adjacent maxillary incisors were treated with one medicament and contralateral incisors with the other medicament, or left as untreated controls. Animals were sacrificed 8 weeks later and the teeth prepared for histomorphometric evaluation of periodontal ligament inflammation and root resorption. Periodontal ligament inflammation and inflammatory root resorption were markedly inhibited by both calcium hydroxide and corticosteroid-antibiotic relative to untreated controls. Replacement resorption was lowest in the corticosteroid-antibiotic group, and significantly (P<0.05) more normal periodontal ligament was present in this group (79.6%) than in calcium hydroxide and control groups (64.6% and 62.7%, respectively). Treatment with the corticosteroid-antibiotic inhibited inflammatory resorption and was slightly more effective than calcium hydroxide in producing a periodontal healing response. [source] Differential Pulse Anodic Stripping Voltammetric Simultaneous Determination of Copper(II) and Silver(I) with Bis(2-hydroxyacetophenone) Butane-2,3-dihydrazone Modified Carbon Paste ElectrodesELECTROANALYSIS, Issue 19 2010M. B. Gholivand Abstract The behavior of a modified carbon paste electrode (CPE) for simultaneous determination of copper(II) and silver(I) by anodic adsorptive stripping voltammetry (ASV) was studied. The electrode was built incorporating the bis(2-hydroxyacetophenone) butane-2,3-dihydrazone (BHAB) as a complexing agent to a Nujol-graphite base paste. The resulting electrode demonstrated linear responses over the range of Cu(II) and Ag(I) concentrations 0.1,20 and 0.01,2.0,µM respectively. The relative standard deviation (RSD) for the determination of 5.0,µM of both metal ions were 2.9 and 3.1,% for Cu(II) and Ag(I), respectively. The method has been applied to the analysis of copper in wheat and barley seed samples and silver in developed radiological film. [source] Glassy Carbon Paste Electrodes for the Determination of Fructosyl ValineELECTROANALYSIS, Issue 6 2010Hui-Ching Chien Abstract Nearly 200,million people worldwide have type-2 diabetes. Glucose sensors are routinely used for diagnosis; however, the relative amount of glycosylated hemoglobin (HbA1c) may be a better marker. A working electrode made from bare glassy carbon paste was used for sensing fructosyl valine (Fru-Val), a component of HbA1c. Amperometric measurements revealed a linear relationship between Fru-Val concentration and the sensing current. The square correlation coefficient and the sensitivity were 0.999 and 5.26,,A mM,1, respectively. The minimum detection limit was less than 0.05,mM. [source] Working Electrodes from Amalgam Paste for Electrochemical MeasurementsELECTROANALYSIS, Issue 4 2008Bogdan Yosypchuk Abstract Paste electrode with paste amalgam as an active electrode material is described here for the first time. Designed electrode from silver paste amalgam (AgA-PE) is solely metallic and does not contain any organic binder. Mechanical surface regeneration of AgA-PE is performed in the same way as for classical carbon paste electrodes and reproducibility of such regeneration is about 10%. Electrochemical surface regeneration appeared very efficient for most measurements. In dependence on paste metal content, the electrode surface can be liquid (resembling a film) or rather solid. The hydrogen overvoltage on AgA-PE is high, and the electrode allows measurements at highly negative potentials. AgA-PE is well suited for study of reduction or oxidation processes without an accumulation step. Anodic stripping voltammetry of some metals tested on the electrode is influenced by formation of intermetallic compounds. The measurement based on cathodic stripping voltammetry (adenine, cysteine) and on catalytic processes from adsorbed state (complex of osmium tetroxide with 2,2,-bipyridine) can be performed on AgA-PE practically under the same conditions as found earlier for HMDE and for silver solid amalgam electrode. The working electrode from paste amalgam combines the advantages of paste and metal electrodes. [source] Stripping Voltammetry of Cerium(IIl) with a Chemically Modified Carbon Paste Electrode Containing Functionalized Nanoporous Silica GelELECTROANALYSIS, Issue 2 2008Mehran Javanbakht Abstract This research introduces the design of an adsorptive stripping voltammetric method for the cerium(III) determination at a carbon paste electrode, chemically modified with dipyridyl-functionalized nanoporous silica gel (DPNSG-CPE). The electroanalytical procedure comprised two steps: the Ce(III) chemical accumulation at ,200,mV followed by the electrochemical detection of the Ce(III)/dipyridyl complex, using anodic stripping voltammetry. The factors, influencing the adsorptive stripping performance, were optimized including the modifier quantity in the paste, the electrolyte concentrations, the solution pH and the accumulation potential or time. The resulting electrode demonstrated a linear response over a wide range of Ce(III) concentration (1.0,28,ng mL,1). The precision for seven determinations of 4 and 10,ng mL,1 Ce(III) was 3.2% and 2.5% (relative standard deviation), respectively. The prepared electrode was used for the cerium determination in real samples and very good recovery results were obtained. [source] Determination of Trace Amounts of Copper in Tap Water Samples with a Calix[4]arene Modified Carbon Paste Electrode by Differential Pulse Anodic Stripping VoltammetryELECTROANALYSIS, Issue 10 2007Çelik Canpolat Abstract A calix[4]arene modified carbon paste electrode was used for trace determination of copper. The study of the preconcentration of copper as well as the other heavy metal ions at the modified electrode, with subsequent measurement by differential pulse anodic stripping voltammetry (DPASV), indicates the efficient open-circuit accumulation of the analytes onto the electrode. Many parameters such as the composition of the paste, pH, preconcentration time and stirring rate influence the response of the measurement. The procedure was optimized for copper determination. For a 10-minute preconcentration time at pH,6.5,7.5, the detection limit (LOD) was 1.1,,g L,1. The optimized method was successfully applied to the determination of copper in tap water sample by means of standard addition procedure. The copper content of the sample was comparable with the result obtained with AAS method. [source] Electrocatalytic Oxidation and Voltammetric Determination of Hydrazine on the Tetrabromo- p -Benzoquinone Modified Carbon Paste ElectrodeELECTROANALYSIS, Issue 5 2007Jahan-Bakhsh Raoof Abstract The electrochemical properties of hydrazine studied at the surface of a carbon paste electrode spiked with p -bromanil (tetrabromo- p -benzoquinone) using cyclic voltammetry (CV), double potential-step chronoamperometry and differential pulse voltammetry (DPV) in aqueous media. The results show this quinone derivative modified carbon paste electrode, can catalyze the hydrazine oxidation in an aqueous buffered solution. It has been found that under the optimum conditions (pH,10.00), the oxidation of hydrazine at the surface of this carbon paste modified electrode occurs at a potential of about 550,mV less positive than that of a bar carbon paste electrode. The electrocatalytic oxidation peak current of hydrazine showed a linear dependent on the hydrazine concentrations and linear analytical curves were obtained in the ranges of 6.00×10,5 M,8.00×10,3 M and 7.00×10,6 M,8.00×10,4 M of hydrazine concentration with CV and differential pulse voltammetry (DPV) methods, respectively. The detection limits (3,) were determined as 3.6×10,5 M and 5.2×10,6 M by CV and DPV methods. This method was also used for the determination of hydrazine in the real sample (waste water of the Mazandaran wood and paper factory) by standard addition method. [source] | ||||||||||||||||||||||||||||