Sample records for ionomics information management

  1. Purdue ionomics information management system. An integrated functional genomics platform.

    PubMed

    Baxter, Ivan; Ouzzani, Mourad; Orcun, Seza; Kennedy, Brad; Jandhyala, Shrinivas S; Salt, David E

    2007-02-01

    The advent of high-throughput phenotyping technologies has created a deluge of information that is difficult to deal with without the appropriate data management tools. These data management tools should integrate defined workflow controls for genomic-scale data acquisition and validation, data storage and retrieval, and data analysis, indexed around the genomic information of the organism of interest. To maximize the impact of these large datasets, it is critical that they are rapidly disseminated to the broader research community, allowing open access for data mining and discovery. We describe here a system that incorporates such functionalities developed around the Purdue University high-throughput ionomics phenotyping platform. The Purdue Ionomics Information Management System (PiiMS) provides integrated workflow control, data storage, and analysis to facilitate high-throughput data acquisition, along with integrated tools for data search, retrieval, and visualization for hypothesis development. PiiMS is deployed as a World Wide Web-enabled system, allowing for integration of distributed workflow processes and open access to raw data for analysis by numerous laboratories. PiiMS currently contains data on shoot concentrations of P, Ca, K, Mg, Cu, Fe, Zn, Mn, Co, Ni, B, Se, Mo, Na, As, and Cd in over 60,000 shoot tissue samples of Arabidopsis (Arabidopsis thaliana), including ethyl methanesulfonate, fast-neutron and defined T-DNA mutants, and natural accession and populations of recombinant inbred lines from over 800 separate experiments, representing over 1,000,000 fully quantitative elemental concentrations. PiiMS is accessible at www.purdue.edu/dp/ionomics.

  2. Purdue Ionomics Information Management System. An Integrated Functional Genomics Platform1[C][W][OA

    PubMed Central

    Baxter, Ivan; Ouzzani, Mourad; Orcun, Seza; Kennedy, Brad; Jandhyala, Shrinivas S.; Salt, David E.

    2007-01-01

    The advent of high-throughput phenotyping technologies has created a deluge of information that is difficult to deal with without the appropriate data management tools. These data management tools should integrate defined workflow controls for genomic-scale data acquisition and validation, data storage and retrieval, and data analysis, indexed around the genomic information of the organism of interest. To maximize the impact of these large datasets, it is critical that they are rapidly disseminated to the broader research community, allowing open access for data mining and discovery. We describe here a system that incorporates such functionalities developed around the Purdue University high-throughput ionomics phenotyping platform. The Purdue Ionomics Information Management System (PiiMS) provides integrated workflow control, data storage, and analysis to facilitate high-throughput data acquisition, along with integrated tools for data search, retrieval, and visualization for hypothesis development. PiiMS is deployed as a World Wide Web-enabled system, allowing for integration of distributed workflow processes and open access to raw data for analysis by numerous laboratories. PiiMS currently contains data on shoot concentrations of P, Ca, K, Mg, Cu, Fe, Zn, Mn, Co, Ni, B, Se, Mo, Na, As, and Cd in over 60,000 shoot tissue samples of Arabidopsis (Arabidopsis thaliana), including ethyl methanesulfonate, fast-neutron and defined T-DNA mutants, and natural accession and populations of recombinant inbred lines from over 800 separate experiments, representing over 1,000,000 fully quantitative elemental concentrations. PiiMS is accessible at www.purdue.edu/dp/ionomics. PMID:17189337

  3. A Review of Glass-Ionomer Cements for Clinical Dentistry

    PubMed Central

    Sidhu, Sharanbir K.; Nicholson, John W.

    2016-01-01

    This article is an updated review of the published literature on glass-ionomer cements and covers their structure, properties and clinical uses within dentistry, with an emphasis on findings from the last five years or so. Glass-ionomers are shown to set by an acid-base reaction within 2–3 min and to form hard, reasonably strong materials with acceptable appearance. They release fluoride and are bioactive, so that they gradually develop a strong, durable interfacial ion-exchange layer at the interface with the tooth, which is responsible for their adhesion. Modified forms of glass-ionomers, namely resin-modified glass-ionomers and glass carbomer, are also described and their properties and applications covered. Physical properties of the resin-modified glass-ionomers are shown to be good, and comparable with those of conventional glass-ionomers, but biocompatibility is somewhat compromised by the presence of the resin component, 2 hydroxyethyl methacrylate. Properties of glass carbomer appear to be slightly inferior to those of the best modern conventional glass-ionomers, and there is not yet sufficient information to determine how their bioactivity compares, although they have been formulated to enhance this particular feature. PMID:27367737

  4. Nonequilibrium Simulations of Ion Dynamics in Ionomer Melts

    NASA Astrophysics Data System (ADS)

    Frischknecht, Amalie

    Ionomers, polymers containing a small fraction of covalently bound ionic groups, are of interest as possible electrolytes in batteries. However, to date ionomers do not have sufficiently high conductivities for practical application, most likely because the ions tend to form aggregates, leading to slow ion transport. To build a better understanding of the relationships among ionomer chemistry, morphology, and ion transport, we have performed a series of molecular dynamics simulations and connected aspects of these simulations with experiment. In previous work using both atomistic and coarse-grained models, we showed that precise ionomers (with a fixed spacing between ionic groups along the polymer backbone) exhibit a range of ionic aggregate morphologies, from discrete clusters to percolated aggregates. In this talk I will describe recent simulations of our coarse-grained ionomer melts in an applied electric field. From a constant applied field, we are able to extract the ion mobilities and hence conductivities. We find that ionomers with percolated ionic aggregate morphologies have higher ion mobilities and hence higher conductivities. Application of an oscillating electric field enables us to calculate the frequency-dependent conductivity of the model ionomer melts. The real part of the conductivity has a high frequency peak associated with plasma oscillations, and a very broad low frequency peak associated with ion motions in ionic aggregates. I will end with comments on the connections to atomistic simulations and to experimental probes of ion dynamics. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  5. Self-repairing systems based on ionomers and epoxidized natural rubber blends.

    PubMed

    Rahman, Md Arifur; Penco, Maurizio; Peroni, Isabella; Ramorino, Giorgio; Grande, Antonio Mattia; Di Landro, Luca

    2011-12-01

    The development of materials with the ability of intrinsic self-repairing after damage in a fashion resembling that of living tissues has important scientific and technological implications, particularly in relation to cost-effective approaches toward damage management of materials. Natural rubbers with epoxy functional groups in the macromolecular chain (ENR) and ethylene-methacrylic acid ionomers having acid groups partially neutralized with metal ions possess self-repairing behavior following high energy impacts. This research investigates the self-repairing behavior of both ENR and ionomers during ballistic puncture test on the basis of their thermal and mechanical properties. Heterogeneous blending of ionomers and ENR have also been used here as a strategy to tune the thermal and mechanical properties of the materials. Interestingly, blends of sodium ion containing ionomer exhibit complete self-repairing behavior, whereas blends of zinc ion containing ionomer show limited mending. The chemical structure studied by FTIR and thermal analysis shows that both ion content of ionomer and functionality of ENR have significant influence on the self-repairing behavior of blends. The mobility of rubbery phases along with its interaction to ionomer phase in the blends significantly changes the mending capability of materials. The healing behavior of the materials has been discussed on the basis of their thermal, mechanical, and rheological tests for each materials. © 2011 American Chemical Society

  6. Ionomics: The functional genomics of elements.

    PubMed

    Baxter, Ivan

    2010-03-01

    Ionomics is the study of elemental accumulation in living systems using high-throughput elemental profiling. This approach has been applied extensively in plants for forward and reverse genetics, screening diversity panels, and modeling of physiological states. In this review, I will discuss some of the advantages and limitations of the ionomics approach as well as the important parameters to consider when designing ionomics experiments, and how to evaluate ionomics data.

  7. [Resin-modified glass-ionomers in dentistry].

    PubMed

    Gladys, S; Van Meerbeek, B; Braem, M; Lambrechts, P; Vanherle, G

    1996-11-01

    The resin-modified glass-ionomers contain the essential components of both a conventional glass-ionomer and a visible light-cured resin. They have several advantages like longer working time, shorter setting time, bonding to tooth structure, fluoride-release, better aesthetics than conventional glass-ionomers and ease in use. As disadvantages can be mentioned the polymerisation shrinkage, trapping of air-bubbles, difficulties in colour choice and contouring. A physical and mechanical characterisation was necessary to define the possibilities and limits of these materials. It can be stated that the strength and aesthetic appearance of resin-modified glass-ionomers are less than that of composites, but better than that of conventional glass-ionomers. Clinically, this is expressed in a rough and dull surface compared to a composite restoration. They are not indicated in stress bearing areas. Consequently, they are mainly indicated in cervical class V-restorations in the postcanine region, and probably restorations in pedodontics, geriatric dentistry and for patients with a high caries activity.

  8. Self-Healing Behavior of Ethylene-Based Ionomers

    NASA Technical Reports Server (NTRS)

    Kalista, Stephen J., Jr.; Ward, Thomas C.; Oyetunji, Zainab

    2004-01-01

    The self-healing behavior of poly(ethylene-co-methacrylic acid) (EMAA)-based ionomers holds tremendous potential for use in a wide variety of unique applications. However, to effectively utilize this self-healing behavior and to design novel materials which possess this ability, the mechanism by which they heal must first be understood ionomers are a class of polymers that can be described as copolymers containing less than 15 mol% ionic content whereby the bulk properties are governed by ionic interactions within the polymer. These ionic groups aggregate into discrete regions known as multiplets which overlap forming clusters that act as physical cross-links profoundly influencing the bulk physical properties. These clusters possess an order-disorder transition (T(sub i)) where the clustered regions may rearrange themselves given time and stimuli. Recognizing the strong influence of these ionic regions on other well understood ionomer properties, their role in self-heating behavior will be assessed. The self-healing behavior is observed following projectile puncture. It has been suggested that during impact energy is passed to the ionomer material, heating it to the melt state. After penetration, it is proposed that the ionic regions maintain their attractions and flow together patching the hole. Thus, the importance of this ionic character and is unique interaction must be established. This will be accomplished through examination of materials with varying ionic content and through the analysis of the T(sub i). The specific ionomer systems examined include a number of ethylene-based materials. Materials of varying ionic content, including the non-ionic base copolymers, will be examined by peel tests, projectile impact and DSC analysis. The information will also be compared with some basic data on LDPE material.

  9. Dispersions of polymer ionomers: I.

    PubMed

    Capek, Ignác

    2004-12-31

    The principal subject discussed in the current paper is the effect of ionic functional groups in polymers on the formation of nontraditional polymer materials, polymer blends or polymer dispersions. Ionomers are polymers that have a small amount of ionic groups distributed along a nonionic hydrocarbon chain. Specific interactions between components in a polymer blend can induce miscibility of two or more otherwise immiscible polymers. Such interactions include hydrogen bonding, ion-dipole interactions, acid-base interactions or transition metal complexation. Ion-containing polymers provide a means of modifying properties of polymer dispersions by controlling molecular structure through the utilization of ionic interactions. Ionomers having a relatively small number of ionic groups distributed usually along nonionic organic backbone chains can agglomerate into the following structures: (1) multiplets, consisting of a small number of tightly packed ion pairs; and (2) ionic clusters, larger aggregates than multiplets. Ionomers exhibit unique solid-state properties as a result of strong associations among ionic groups attached to the polymer chains. An important potential application of ionomers is in the area of thermoplastic elastomers, where the associations constitute thermally reversible cross-links. The ionic (anionic, cationic or polar) groups are spaced more or less randomly along the polymer chain. Because in this type of ionomer an anionic group falls along the interior of the chain, it trails two hydrocarbon chain segments, and these must be accommodated sterically within any domain structure into which the ionic group enters. The primary effects of ionic functionalization of a polymer are to increase the glass transition temperature, the melt viscosity and the characteristic relaxation times. The polymer microstructure is also affected, and it is generally agreed that in most ionomers, microphase-separated, ion-rich aggregates form as a result of strong ion

  10. Nature and properties of ionomer assemblies. II.

    PubMed

    Capek, Ignác

    2005-12-30

    The principle subject in the current paper is to summarize and characterize the ionomers based on polymers and copolymers such as polystyrene (PSt), polyisoprene (PIP), polybutadiene (PB), poly(styrene-b-isobutylene-b-styrene) (PSt-PIB-PSt), poly(butadiene-styrene) (PB-PSt), poly(ethylene terephthalate) (PET), poly(butylene adipate) (PBA), poly(butylene succinate) (PBSi), poly(dimethylcarbosiloxanes), polyurethane, etc. The self-assembly of ionomers, models concerning ionomer morphologies, physical and rheological properties of ionomer phase and percolation behavior of ionomers were discussed. The ionomer phase materials and dispersions have been characterized by differential scanning calorimetry (DSC), small-angle X-ray catering (SAXS), small-angle neutron scattering (SANS), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), etc. The wide range of compositions, molecular architectures, and morphologies present in ionomeric disperse systems are of great interest. The research is particularly devoted to the potential application of these materials and an understanding of the fundamental principles of the ionomers. They are extremely complex systems, sensitive to changes in structure and composition, and therefore not easily amenable to modeling and to the derivation of general patterns of behavior. The reviewed data indicate that a large number of parameters are important in influencing multiplet formation and clustering in random ionomers. Among these are the ion content, size of the polyion and counterion, dielectric constant of the host, T(g) of the polymer, rigidity or persistence length of the backbone, position of the ion pair relative to the backbone, steric constraints, amount and nature of added additive (plasticizer), thermal history, etc.

  11. Ionomers and methods of making same and uses thereof

    DOEpatents

    Coates, Geoffrey W.; Kostalik, IV, Henry A.; Clark, Timothy J.; Robertson, Nicholas J.

    2016-11-15

    Ionomers comprising ionic groups such as, for example, tetraalkylammonium groups and methods of making such ionomers. For example, the ionomers can be produced by ring opening metathesis polymerization of alkene-containing monomers with tetraalkylammonium groups and, optionally, alkene-containing monomers without tetraalkylammonium groups. The ionomers can be used in applications such as, for example, fuel cell applications.

  12. Glass-ionomer cements as restorative and preventive materials.

    PubMed

    Ngo, Hien

    2010-07-01

    This article focuses on glass-ionomer cement (GIC) and its role in the clinical management of caries. It begins with a brief description of GIC, the mechanism of fluoride release and ion exchange, the interaction between GIC and the external environment, and finally the ion exchange between GIC and the tooth at the internal interface. The importance of GIC, as a tool, in caries management, in minimal intervention dentistry (MI), and Caries Management by Risk Assessment (CAMBRA) also will be highlighted. Copyright 2010. Published by Elsevier Inc.

  13. ICP-MS/MS-Based Ionomics: A Validated Methodology to Investigate the Biological Variability of the Human Ionome.

    PubMed

    Konz, Tobias; Migliavacca, Eugenia; Dayon, Loïc; Bowman, Gene; Oikonomidi, Aikaterini; Popp, Julius; Rezzi, Serge

    2017-05-05

    We here describe the development, validation and application of a quantitative methodology for the simultaneous determination of 29 elements in human serum using state-of-the-art inductively coupled plasma triple quadrupole mass spectrometry (ICP-MS/MS). This new methodology offers high-throughput elemental profiling using simple dilution of minimal quantity of serum samples. We report the outcomes of the validation procedure including limits of detection/quantification, linearity of calibration curves, precision, recovery and measurement uncertainty. ICP-MS/MS-based ionomics was used to analyze human serum of 120 older adults. Following a metabolomic data mining approach, the generated ionome profiles were subjected to principal component analysis revealing gender and age-specific differences. The ionome of female individuals was marked by higher levels of calcium, phosphorus, copper and copper to zinc ratio, while iron concentration was lower with respect to male subjects. Age was associated with lower concentrations of zinc. These findings were complemented with additional readouts to interpret micronutrient status including ceruloplasmin, ferritin and inorganic phosphate. Our data supports a gender-specific compartmentalization of the ionome that may reflect different bone remodelling in female individuals. Our ICP-MS/MS methodology enriches the panel of validated "Omics" approaches to study molecular relationships between the exposome and the ionome in relation with nutrition and health.

  14. Simulation of Ionic Aggregation and Ion Dynamics in Model Ionomers

    NASA Astrophysics Data System (ADS)

    Frischknecht, Amalie L.

    2012-02-01

    Ionomers, polymers containing a small fraction of covalently bound ionic groups, are of interest as possible electrolytes in batteries. A single-ion conducting polymer electrolyte would be safer and have higher efficiency than the currently-used liquid electrolytes. However, to date ionomeric materials do not have sufficiently high conductivities for practical application. This is most likely because the ions tend to form aggregates, leading to slow ion transport. A key question is therefore how molecular structure affects the ionic aggregation and ion dynamics. To probe these structure-property relationships, we have performed molecular simulations of a set of recently synthesized poly(ethylene-co-acrylic acid) copolymers and ionomers, with a focus on the morphology of the ionic aggregates. The ionomers have a precise, constant spacing of charged groups, making them ideal for direct comparisons with simulations. Ab initio calculations give insight into the expected coordination of cations with fragments of the ionomers. All-atom molecular dynamics (MD) simulations of the ionomer melt show aggregation of the ionic groups into extended string-like clusters. An extensive set of coarse-grained molecular dynamics simulations extend the results to longer times and larger length scales. The structure factors calculated from the MD simulations compare favorably with x-ray scattering data. Furthermore, the simulations give a detailed picture of the sizes, shapes, and composition of the ionic aggregates, and how they depend on polymer architecture. Implications for ion transport will be discussed. [Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  15. Structure-property relationships in semicrystalline copolymers and ionomers

    NASA Astrophysics Data System (ADS)

    Wakabayashi, Katsuyuki

    Many outstanding physical properties of ethylene/(meth)acrylic acid (E/(M)AA) copolymers and ionomers are associated with their nanometer-scale morphology, which consists of ethylene crystallites, amorphous segments, and acid/ionic functional groups. The goal of this dissertation is a fundamental understanding of the interplay between these structural motifs and the consequent effects on the material properties. We identify small-strain modulus as a key mechanical property and investigate its dependence upon material structure through X-ray scattering, calorimetry, and mechanical property measurements. We first treat E/(M)AA copolymers as composites of polyethylene crystallites and amorphous regions, and establish a quantitative combining rule to describe the copolymer modulus. At temperatures above the Tg of the copolymers, a monotonic increase in modulus with crystallinity is quantitatively described by the Davies equation for two-phase composites, which serves as the basis for separating the effects of amorphous and crystalline phases throughout this dissertation. The room-temperature modulus of E/(M)AA copolymers is concurrently affected by ethylene crystallinity and proximity to the amorphous phase Tg, which rises through room temperature with increasing comonomer content. In E/(M)AA ionomers, phase separation and aggregation of ionic groups provide additional stiffness and toughness. Ionomers are modeled as composites of crystallites and ionically crosslinked rubber, whose amorphous phase modulus far above the ionomer Tg is satisfactorily described by simple rubber elasticity theory. Thermomechanical analyses probe the multi-step relaxation behavior of E/(M)AA ionomers and lead to the development of a new semicrystalline ionomer morphological model, wherein secondary crystallites and ionic aggregates together form rigid percolated pathways throughout the amorphous phase. Metal soaps are oligomeric analogs of E/(M)AA ionomers, which can be blended into

  16. Blends of polyester ionomers with polar polymers: Interactions, reactions, and compatibilization

    NASA Astrophysics Data System (ADS)

    Boykin, Timothy Lamar

    The compatibility of amorphous and semicrystalline polyester ionomers with various polar polymers (i.e., polyesters and polyamides) has been investigated for their potential use as minor component compatibilizers. The degree of compatibility (i.e., ranging from incompatible to miscible) between the polyester ionomers and the polar polymers was determined by evaluating the effect of blend composition on the melting behavior and phase behavior of binary blends. In addition, the origin of compatibility and/or incompatibility for each of the binary blends (i.e., polyamide/ionomer and polyester/ionomer) was determined by evaluating blends prepared by both solution and melt mixed methods. Subsequent to investigation of the binary blends, the effect of polyester ionomer addition on the compatibility of polyamide/polyester blends was investigated by evaluating the mechanical properties and phase morphology of ionomer compatibilized polyamide/polyester blends. Polyester ionomers (amorphous and semicrystalline) were shown to exhibit a high degree of compatibility (even miscibility) with polyamides, such as nylon 6,6 (N66). Compatibility was attributed to specific interactions between the metal counterion of the polyester ionomer and the amide groups of N66. The degree of compatibility (or miscibility) was shown to be dependent on the counterion type of the ionomer, with the highest degree exhibited by blends containing the divalent form of the polyester ionomers. Although polyester ionomers were shown to exhibit incompatibility with both poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT), increasing the time of melt processing significantly enhanced the compatibility of the polyester ionomers with both PET and PBT. The observed enhancement in compatibility was attributed to ester-ester interchange between the polyester blend components, which was confirmed by NMR spectroscopy. The addition of polyester ionomers as a minor component compatibilizer (i

  17. Comparative Evaluation of Microleakage Between Nano-Ionomer, Giomer and Resin Modified Glass Ionomer Cement in Class V Cavities- CLSM Study.

    PubMed

    Bollu, Indira Priyadarshini; Hari, Archana; Thumu, Jayaprakash; Velagula, Lakshmi Deepa; Bolla, Nagesh; Varri, Sujana; Kasaraneni, Srikanth; Nalli, Siva Venkata Malathi

    2016-05-01

    Marginal integrity of adhesive restorative materials provides better sealing ability for enamel and dentin and plays an important role in success of restoration in Class V cavities. Restorative material with good marginal adaptation improves the longevity of restorations. Aim of this study was to evaluate microleakage in Class V cavities which were restored with Resin Modified Glass Ionomer Cement (RMGIC), Giomer and Nano-Ionomer. This in-vitro study was performed on 60 human maxillary and mandibular premolars which were extracted for orthodontic reasons. A standard wedge shaped defect was prepared on the buccal surfaces of teeth with the gingival margin placed near Cemento Enamel Junction (CEJ). Teeth were divided into three groups of 20 each and restored with RMGIC, Giomer and Nano-Ionomer and were subjected to thermocycling. Teeth were then immersed in 0.5% Rhodamine B dye for 48 hours. They were sectioned longitudinally from the middle of cavity into mesial and distal parts. The sections were observed under Confocal Laser Scanning Microscope (CLSM) to evaluate microleakage. Depth of dye penetration was measured in millimeters. The data was analysed using the Kruskal Wallis test. Pair wise comparison was done with Mann Whitney U Test. A p-value<0.05 is taken as statistically significant. Nano-Ionomer showed less microleakage which was statistically significant when compared to Giomer (p=0.0050). Statistically no significant difference was found between Nano Ionomer and RMGIC (p=0.3550). There was statistically significant difference between RMGIC and Giomer (p=0.0450). Nano-Ionomer and RMGIC showed significantly less leakage and better adaptation than Giomer and there was no statistically significant difference between Nano-Ionomer and RMGIC.

  18. Comparative Evaluation of Microleakage Between Nano-Ionomer, Giomer and Resin Modified Glass Ionomer Cement in Class V Cavities- CLSM Study

    PubMed Central

    Hari, Archana; Thumu, Jayaprakash; Velagula, Lakshmi Deepa; Bolla, Nagesh; Varri, Sujana; Kasaraneni, Srikanth; Nalli, Siva Venkata Malathi

    2016-01-01

    Introduction Marginal integrity of adhesive restorative materials provides better sealing ability for enamel and dentin and plays an important role in success of restoration in Class V cavities. Restorative material with good marginal adaptation improves the longevity of restorations. Aim Aim of this study was to evaluate microleakage in Class V cavities which were restored with Resin Modified Glass Ionomer Cement (RMGIC), Giomer and Nano-Ionomer. Materials and Methods This in-vitro study was performed on 60 human maxillary and mandibular premolars which were extracted for orthodontic reasons. A standard wedge shaped defect was prepared on the buccal surfaces of teeth with the gingival margin placed near Cemento Enamel Junction (CEJ). Teeth were divided into three groups of 20 each and restored with RMGIC, Giomer and Nano-Ionomer and were subjected to thermocycling. Teeth were then immersed in 0.5% Rhodamine B dye for 48 hours. They were sectioned longitudinally from the middle of cavity into mesial and distal parts. The sections were observed under Confocal Laser Scanning Microscope (CLSM) to evaluate microleakage. Depth of dye penetration was measured in millimeters. Statistical Analysis The data was analysed using the Kruskal Wallis test. Pair wise comparison was done with Mann Whitney U Test. A p-value<0.05 is taken as statistically significant. Results Nano-Ionomer showed less microleakage which was statistically significant when compared to Giomer (p=0.0050). Statistically no significant difference was found between Nano Ionomer and RMGIC (p=0.3550). There was statistically significant difference between RMGIC and Giomer (p=0.0450). Conclusion Nano-Ionomer and RMGIC showed significantly less leakage and better adaptation than Giomer and there was no statistically significant difference between Nano-Ionomer and RMGIC. PMID:27437363

  19. In vitro fatigue behavior of restorative composites and glass ionomers.

    PubMed

    Braem, M J; Lambrechts, P; Gladys, S; Vanherle, G

    1995-03-01

    This in vitro study was conducted to investigate the fatigue behavior of several dental restoratives, including composites, glass ionomers and a resin-reinforced glass ionomer. Fatigue was imposed under a reverse stress-controlled regimen, following a staircase approach. Samples were stored and tested under both dry and wet conditions. The following parameters were measured and analyzed: Young's modulus, restrained fracture strength, and flexural fatigue limit. As a general trend, all products showed a decrease in Young's modulus following water sorption. For all products except the resin-reinforced glass ionomer, the same trend was seen in the restrained fracture strength. This is, however, no longer valid for the flexural fatigue limit: the trend is steady-state for the glass ionomers, status quo for the resin-reinforced glass ionomer, and all composites tested show a decrease. The diversity in structure of both composites and glass ionomers does not allow findings for one product to be extrapolated to other similar products.

  20. Exploring substrate/ionomer interaction under oxidizing and reducing environments

    DOE PAGES

    Tesfaye, Meron; MacDonald, Andrew N.; Dudenas, Peter J.; ...

    2018-02-09

    Local gas transport limitation attributed to the ionomer thin-film in the catalyst layer is a major deterrent to widespread commercialization of polymer-electrolyte fuel cells. So far functionality and limitations of these thin-films have been assumed identical in the anode and cathode. In this study, Nafion ionomer thin-films on platinum(Pt) support were exposed to H 2 and air as model schemes, mimicking anode and cathode catalyst layers. Findings indicate decreased swelling, increased densification of ionomer matrix, and increased humidity-induced aging rates in reducing environment, compared to oxidizing and inert environments. Observed phenomenon could be related to underlying Pt-gas interaction dictating Pt-ionomermore » behavior. Presented results could have significant implications about the disparate behavior of ionomer thin-film in anode and cathode catalyst layers.« less

  1. Water dynamics in glass ionomer cements

    NASA Astrophysics Data System (ADS)

    Berg, M. C.; Jacobsen, J.; Momsen, N. C. R.; Benetti, A. R.; Telling, M. T. F.; Seydel, T.; Bordallo, H. N.

    2016-07-01

    Glass ionomer cements (GIC) are an alternative for preventive dentistry. However, these dental cements are complex systems where important motions related to the different states of the hydrogen atoms evolve in a confined porous structure. In this paper, we studied the water dynamics of two different liquids used to prepare either conventional or resin-modified glass ionomer cement. By combining thermal analysis with neutron scattering data we were able to relate the water structure in the liquids to the materials properties.

  2. The surface pH of glass ionomer cavity lining agents.

    PubMed

    Woolford, M J

    1989-12-01

    It is considered that acid release from the surface of glass ionomer (polyalkenoate) cements may be associated with early pulpal sensitivity following the use of these materials. This study was carried out to examine the surface pH of different types of glass ionomer lining cements using a flat-ended pH electrode. It was found that the surface pH remains low for this group of materials during the first hour of setting. Different types of glass ionomer lining cement were also shown to behave differently when considering acid release from the surface. Conclusions regarding the behaviour of glass ionomers should only be made with reference to the specific material tested.

  3. A water-responsive shape memory ionomer with permanent shape reconfiguration ability

    NASA Astrophysics Data System (ADS)

    Bai, Yongkang; Zhang, Jiwen; Tian, Ran; Chen, Xin

    2018-04-01

    In this work, a water-responsive shape memory ionomer with high toughness was fabricated by cross-linking hyaluronic acid sodium (HAS) and polyvinyl alcohol (PVA) through coordination interactions. The strong Fe3+-carboxyl (from HAS) coordination interactions served as main physical cross-linking points for the performance of water-responsive shape memory, which associated with the flexibility of PVA chain producing excellent mechanical properties of this ionomer. The optimized ionomer was not only able to recover to its original shape within just 22 s by exposing to water, but exhibited high tensile strength up to 35.4 MPa and 4 times higher tractility than the ionomer without PVA. Moreover, the ionomers can be repeatedly programed to various new permanent shapes on demand due to the reversible physical interactions, which still performed complete and fast geometric recovery under stimuli even after 4 cycles of reprograming with 3 different shapes. The excellent shape memory and strong mechanical behaviors make our ionomers significant and promising smart materials for variety of applications.

  4. Properties of a proline-containing glass ionomer dental cement.

    PubMed

    Ansari, Sahar; Moshaverinia, Maryam; Roohpour, Nima; Chee, Winston W L; Schricker, Scott R; Moshaverinia, Alireza

    2013-11-01

    Proline-containing glass ionomers are promising fast-set dental restorative materials with superior mechanical properties; however, little information is available on other physical properties of this type of glass ionomer. The objectives of this study were to synthesize and characterize a polyacrylic acid terpolymer containing proline derivative (PD) and to investigate the physical properties of this glass ionomer cement (GIC) and its cytotoxicity in vitro. A terpolymer of AA (acrylic acid), IA (itaconic acid), and proline derivative (MP) with an 8:1:1 molar ratio was synthesized and characterized. Experimental GIC specimens were made from the synthetized terpolymer with Fuji IX (GC America, Alsip, Ill) commercial glass ionomer powder as recommended by the manufacturer. Specimens were mixed and fabricated at room temperature and were conditioned in distilled water at 37°C for 1 day and 1 week. Vickers hardness was determined with a microhardness tester. The water sorption characteristics and fluoride releasing properties of the specimens were investigated. The in vitro cytotoxicity of the experimental glass ionomer was assessed by evaluating the C2C12 cell metabolism with methyltetrazolium (MTT) assay. Commercial Fuji IX was used as a control for comparison. The data obtained for the experimental GIC (PD) were compared with the control group by using 1- and 2-way ANOVA and the Tukey multiple range test at α=.05. Proline-modified GIC (PD) exhibited significantly higher surface hardness values (Vickers hardness number [VHN] 58 ±6.1) in comparison to Fuji IX GIC (VHN 47 ±5.3) after 1 week of maturation. Statistical analysis of data showed that the water sorption properties of the experimental cement (PD) were significantly greater than those of the control group (P<.05). The experimental GIC showed a significant increase in the amounts of initial fluoride release (P<.05) with continued fluoride release from the bulk of the material. The experimental group

  5. Piezoelectric and mechanical properties of fatigue resistant, self-healing PZT-ionomer composites

    NASA Astrophysics Data System (ADS)

    James, N. K.; Lafont, U.; van der Zwaag, S.; Groen, W. A.

    2014-05-01

    Piezoelectric ceramic-polymer composites with 0-3 connectivity were fabricated using lead zirconium titanate (PZT) powder dispersed in an ionomer (Zn ionomer) and its reference ethylene methacrylic acid copolymer (EMAA) polymer matrix. The PZT-Zn ionomer and PZT-EMAA composites were prepared by melt extrusion followed by hot pressing. The effects of poling conditions such as temperature, time and electric field on the piezoelectric properties of the composites were investigated. The experimentally observed piezoelectric charge coefficient and dielectric constant of the composites were compared with theoretical models. The results show that PZT-Zn ionomer composites have better piezoelectric properties compared to PZT-EMAA composites. The static and fatigue properties of the composites were investigated. The PZT-Zn ionomer composites were found to have excellent fatigue resistance even at strain levels of 4%. Due to the self-healing capabilities of the ionomer matrix, the loss of piezoelectric properties after high strain tensile cyclic loading could be partially recovered by thermal healing.

  6. Estimation of electrode ionomer oxygen permeability and ionomer-phase oxygen transport resistance in polymer electrolyte fuel cells.

    PubMed

    Sambandam, Satheesh; Parrondo, Javier; Ramani, Vijay

    2013-09-28

    The oxygen permeability of perfluorinated and hydrocarbon polymer electrolyte membranes (PEMs; Nafion®, SPEEK and SPSU), which are used as electrolytes and electrode ionomers in polymer electrolyte fuel cells (PEFCs), was estimated using chronoamperometry using a modified fuel cell set-up. A thin, cylindrical microelectrode was embedded into the PEM and used as the working electrode. The PEM was sandwiched between 2 gas diffusion electrodes, one of which was catalyzed and served as the counter and pseudo-reference electrode. Independently, from fuel cell experiments, the oxygen transport resistance arising due to transport through the ionomer film covering the catalyst active sites was estimated at the limiting current and decoupled from the overall mass transport resistance. The in situ oxygen permeability measured at 80 °C and 75% RH of perfluorinated ionomers such as Nafion® (3.85 × 10(12) mol cm(-1) s(-1)) was observed to be an order of magnitude higher than that of hydrocarbon-based PEMs such as SPEEK (0.27 × 10(12) mol cm(-1) s(-1)) and SPSU (0.15 × 10(12) mol cm(-1) s(-1)). The obtained oxygen transport (through ionomer film) resistance values (Nafion® - 1.6 s cm(-1), SPEEK - 2.2 s cm(-1) and SPSU - 3.0 s cm(-1); at 80 °C and 75% RH) correlated well with the measured oxygen permeabilities in these ion-containing polymers.

  7. Molecular mobility, morphology, and ion conduction in ionomers for electroactive devices

    NASA Astrophysics Data System (ADS)

    Tudryn, Gregory J.

    aggregation process in Na ionomers as ionic dipoles thermally randomize and lower the measured dielectric constant of the medium, leading to further aggregation. We observe amplified microphase-separation through ionic groups preferentially solvated by PEO chains, as seen in block copolymers with added salt. Even at 25%PEO / 75%PTMO the ionomers have VFT temperature dependence of conducting ion mobility, meaning that the 25% PEO/ion microphase is still continuous A model is developed to describe the frequency dependent storage and loss modulus and the delay in Rouse motion due to ion association lifetime, as functions of ion content and molecular weight for our low molecular weight ionomers. The ion rearrangement relaxation in dielectric spectroscopy is clearly the ion association lifetime that controls terminal dynamics in linear viscoelasticity, allowing a simple sticky Rouse model, using the most-probable distribution based on NMR Mn, to fully describe master curves of the frequency dependent storage and loss modulus. Using insight from ionic interaction strength, ionic liquids are used as counterions, effectively plasticizing the ionomers without added solvent. Ionic interactions were weakened with increasing counterion size, and with modification of cations using ether-oxygen, promoting self-solvation, which increases conducting ion density by an order of magnitude. Room temperature ionic liquids were subsequently used in combination with NafionRTM membranes as electroactive substrates to correlate ion transport to morphology as a function of volume fraction of ionic liquid. This study illuminated the critical volume uptake of ionic liquid in Nafion, identifying percolation of ionic pathways and a significant increase in dielectric constant at low frequencies, indicating an increase in the number density of ions capable of polarizing at the electrode surface. Consequently, the fundamental information obtained about the structure-property relations of ionomers can be used

  8. Evaluation of a Glass Ionomer Restoration to Treat Hypersensitive Cervical Anatomic Deficiencies.

    DTIC Science & Technology

    1983-03-01

    glass ionomer cement to existing dental cements such as...that the milder pulp reaction to a glass ionomer cement as opposed to a phosphoric acid cement may be explained by the weaker acid makeup of the ASPA...7 Sensitivity Evaluation ........................... 9 Treatment of Dentinal Sensitivity................. 12 Glass Ionomer Cements

  9. Effects of ionomer morphology on oxygen reduction on Pt

    DOE PAGES

    Chlistunoff, Jerzy; Pivovar, Bryan

    2015-05-21

    In this paper, the oxygen reduction reaction (ORR) at the interface between platinum and Nafion 1100 equivalent weight was studied as a function of temperature (20–80 °C), humidity (10–100%), scan rate, the manner in which Nafion film was deposited, and the state of the Pt surface using ultramicroelectrodes employing cyclic voltammetry and chronoamperometry. ORR on smooth electrodes was strongly inhibited under specific conditions dependent on temperature, humidity, and scan rate. From the data presented, we postulate that dynamic changes in the molecular structure of the ionomer at the platinum interface result in differences in ORR voltammetry for films prepared andmore » equilibrated under different conditions. The lack of similar changes for rough, platinized electrodes has been attributed to differences in initial ionomer structure and a higher energy barrier for ionomer restructuring. Finally, these model system studies yield insight into the ionomer-catalyst interface of particular interest for polymer electrolyte fuel cells.« less

  10. A review of glass-ionomers: From conventional glass-ionomer to bioactive glass-ionomer

    PubMed Central

    Khoroushi, Maryam; Keshani, Fateme

    2013-01-01

    Materials used in the body, especially the materials used in various oral cavity regions should be stable and passive without any interactions with the body tissues or fluids. Dental amalgam, composite resins and dental cements are the materials of choice with such properties. The first attempts to produce active materials, which could interact with the human body tissues and fluids were prompted by the concept that fluoride-releasing materials exert useful effects in the body. The concept of using the “smart” materials in dentistry has attracted a lot of attention in recent years. Conventional glass-ionomer (GI) cements have a large number of applications in dentistry. They are biocompatible with the dental pulp to some extent. GI is predominantly used as cements in dentistry; however, they have some disadvantages, the most important of which is lack of adequate strength and toughness. In an attempt to improve the mechanical properties of the conventional GI, resin-modified glass-ionomers have been marketed, with hydrophilic monomers, such as hydroxyethyl methacrylated (HEMA). Some recent studies have evaluated GI with bioactive glass in its structure to validate the claims that such a combination will improve tooth bioactivity, regeneration capacity and restoration. There is ever-increasing interest in the application of bioactive materials in the dental field in an attempt to remineralize affected dentin. The aim of this review article is to evaluate these materials and their characteristics and applications. PMID:24130573

  11. Morphological studies of sulfonated polystyrene and sulfonated EPDM ionomers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jackson, D.A.

    1992-12-31

    Two ionomer systems have been investigated in this research. Sulfonated polystyrene (SPS) is a typical random ionomer and is a good material for studies into the nature of phase separation in ionomers. A series of narrow molecular weight distribution (MWD) zinc neutralized SPS samples of varying sulfonation levels were prepared and analyzed through small angle x-ray scattering (SAXS). Results indicated that the correlation distance varied with both molecular weight and sulfonation level. Increases in the position of the scattering maximum with sulfonation level is the result of a greater number of ionic groups. Increasing molecular weight led to the movementmore » of the scattering maximum to smaller scattering vectors, an indication of larger distances. It was also observed that ionomer peak occurred at smaller scattering vectors for the narrow MWD samples than in corresponding materials of greater dispersity. SAXS was also used to examine the morphology of zinc stearate (ZnSt) filled sulfonated EPDM (S-EPDM) ionomers and the nature of the interaction between the plasticizer and the ionomer. S-EPDM is a material that may find use as a thermoplastic elastomer, although its melt viscosity is too high to allow for convenient processing. The addition of of ZnSt as a plasticizer greatly reduces the melt viscosity of S-EPDM. ZnSt exists in this system as very small crystallites which are associated with ionic groups. As the temperature is increased, the crystallites anneal briefly into larger crystals before melting and diffusing into the S-EPDM matrix. Above the melting temperature of the ZnSt, it solvates the ionic groups of the ionomer, decreasing their self-association and the viscosity of the system. Increasing ZnSt loading is seen in the SAXS as an increase in scattering in the low angle region. However, this increase in intensity is not linear with concentration, showing that ZnSt exists in different environments at higher concentrations.« less

  12. Catalyst-layer ionomer imaging of fuel cells

    DOE PAGES

    Guetaz, Laure; Lopez-Haro, M.; Escribano, S.; ...

    2015-09-14

    Investigation of membrane/electrode assembly (MEA) microstructure has become an essential step to optimize the MEA components and manufacturing processes or to study the MEA degradation. For these investigations, transmission electron microscopy (TEM) is a tool of choice as it provides direct imaging of the different components. TEM is then widely used for analyzing the catalyst nanoparticles and their carbon support. However, the ionomer inside the electrode is more difficult to be imaged. The difficulties come from the fact that the ionomer forms an ultrathin layer surrounding the carbon particles and in addition, these two components, having similar density, present nomore » difference in contrast. In this paper, we show how the recent progresses in TEM techniques as spherical aberration (Cs) corrected HRTEM, electron tomography and X-EDS elemental mapping provide new possibilities for imaging this ionomer network and consequently to study its degradation.« less

  13. Enamel remineralization on teeth adjacent to Class II glass ionomer restorations.

    PubMed

    Segura, A; Donly, K J; Stratmann, R G

    1997-10-01

    To examine the in vitro remineralization of incipient carious lesions on teeth adjacent interproximally to teeth with Class II glass ionomer cement restorations. Artificial carious lesions were created at the contact area of 30 teeth. Ten teeth had Class II glass ionomer cement/resin composite restorations placed, 10 teeth had Class II glass ionomer silver cermet restorations placed and 10 teeth had Class II amalgam restorations placed. Sections 100 microns thick were obtained longitudinally through the caries sites and polarized photomicrographs were taken in imbibition media of water and Thoulet's (R.I. 1.41 and 1.47) solutions, representing 5%, 10% and 25% pore volume respectively. Varnish was placed on the section, leaving only the external section site exposed, then sections were situated back into the original tooth. The restored teeth were abutted to the carious tooth so that the restorations came into contact with the adjacent restoration. The specimens were placed into closed environments of artificial saliva for 14 days, then were photographed again under polarized light and areas of the carious lesions were quantitated. An ANOVA indicated significant variance in adjacent tooth remineralization, when comparing the experimental groups, in imbibition media of water (P < 0.05), Thoulet's 1.41 solution (P < 0.008) and Thoulet's 1.47 solution (P < 0.006). Duncan's multiple range test demonstrated the glass ionomer cement/resin composite group to have significantly greater decrease in pore volume (P < 0.05) than the amalgam control group in water imbibition media and Thoulet's 1.47 media. There was no statistically significant difference between the glass ionomer cement/resin composite and glass ionomer silver cermet groups in these two imbibition media. The glass ionomer cement/resin composite group demonstrated significantly more (P < 0.05) decrease in pore volume than both the glass ionomer silver cermet group and amalgam control group in Thoulet's 1

  14. Damage initiated self-healing in ionomer blends

    NASA Astrophysics Data System (ADS)

    Rahman, Md. Arifur; Penco, Maurizio; Spagnoli, Gloria; Peroni, Isabella; Ramorino, Giorgio; Sartore, Luciana; Bignotti, Fabio; Landro, Luca Di

    2012-07-01

    The development and understanding of self-healing mechanisms have been investigated in blends of ionomers (Poly(ethyelene-co-methacrylic acid), sodium & zinc ions) (EMNa & EMZn) containing both elastomers (Epoxidized natural rubbers (ENR) and cis-1,4-Polyisoprene (PISP)) and crystalline component (Poly(vinly alcohol-co-ethylene) [PVAcE]) as secondary phases. All the blends were prepared by melt-blending and self-healing behavior was studied in ballistic puncture tests. Self-healing behavior of each material was evaluated by observing the impact zones under a stereo-optical microscope and the micrographic results were further supported by the fluid flow test in the punctured zones. Interestingly, ENR50 blends of sodium ion containing ionomers exhibited complete self-repairing behavior while zinc ion containing ionomer showed limited mending but EMNa/ENR25 and EMNa/PISP blends did not show any self-healing behavior following the damage. On the other hand, a composition dependent healing behavior was observed in the EMNa/PVAcE blends where healing was observed up to 30wt% PVAcE containing blends. The chemical structure studied by FTIR analysis showed that both ion content of ionomer and functionality of ENR have significant influence on the self-repairing behavior of blends. TEM analysis revealed that self-healing occurs in the blends when the dispersed phase has a dimension of 100 to 400 nm.

  15. Control and characterization of textured, hydrophobic ionomer surfaces

    NASA Astrophysics Data System (ADS)

    Wang, Xueyuan

    Polymer thin films are of increasing interest in many industrial and technological applications. Superhydrophobic, self-cleaning surfaces have attracted a lot of attention for their application in self-cleaning, anti-sticking coatings, stain resistance, or anti-contamination surfaces in diverse technologies, including medical, transportation, textiles, electronics and paints. This thesis focuses on the preparation of nanometer to micrometer-size particle textured surfaces which are desirable for super water repellency. Textured surfaces consisting of nanometer to micrometer-sized lightly sulfonated polystyrene ionomer (SPS) particles were prepared by rapid evaporation of the solvent from a dilute polymer solution cast onto silica. The effect of the solvent used to spin coat the film, the molecular weight of the ionomer, and the rate of solvent evaporation were investigated. The nano-particle or micron-particle textured ionomer surfaces were prepared by either spin coating or solution casting ionomer solutions at controlled evaporation rates. The surface morphologies were consistent with a spinodal decomposition mechanism where the surface first existed as a percolated-like structure and then ripened into droplets if molecular mobility was retained for sufficient time. The SPS particles or particle aggregates were robust and resisted deformation even after annealing at 120°C for one week. The water contact angles on as-prepared surfaces were relatively low, ~ 90° since the polar groups in ionomer reduce the surface hydrophobicity. After chemical vapor deposition of 1H,1H,2H,2H-perfluorooctyltrichlorosilane, the surface contact angles increased to ~ 109° on smooth surfaces and ~140° on the textured surfaces. Water droplets stuck to these surfaces even when tilted 90 degrees. Superhydrophobic surfaces were prepared by spraying coating ionomer solutions and Chemical Vapor Deposition (CVD) of 1H,1H,2H,2H-perfluorooctyltrichlorosilane onto textured surfaces. The

  16. Bond strength of Bis-GMA and glass ionomer pit and fissure sealants using cyclic fatigue.

    PubMed

    Dewji, H R; Drummond, J L; Fadavi, S; Punwani, I

    1998-02-01

    The aim of the study was to determine the bond strength of glass ionomer and resin-modified glass ionomer sealants compared to Bis-GMA sealants using both static and cyclic fatigue shear testing. Four materials were evaluated: D, a Bis-GMA sealant with 10% phosphoric acid etchant; FC, a resin-modified glass ionomer sealant with 20% polyacrylic acid etchant; FD, a resin-modified glass ionomer sealant with 10% polyacrylic acid etchant; and FSC, a self-cured glass ionomer sealant with no etchant. Gelatin capsules filled with the sealant material were bonded to the enamel surfaces of bovine teeth after appropriate surface conditioning and then tested in shear static and cyclic fatigue. Static and cyclic shear bond strengths, respectively, for each group were (MPa): FC: 21.1+/-2.8 and 17.1+/-3.1; FD: 14.6+/-5.9 and 8.5+/-3.1; D: 10.8+/-4.9 and 4.7+/-2.6; FSC: 8.7 (1.0 and 2.9+/-0.6. The resin-modified glass ionomer sealants had better fatigue bond strength than both Bis-GMA and self-cured glass ionomer sealants with the surface conditioning affecting the bond strength of the resin-modified glass ionomer sealants.

  17. Clinical behaviour of glass ionomer restorations in primary teeth.

    PubMed

    Espelid, I; Tveit, A B; Tornes, K H; Alvheim, H

    1999-08-01

    To compare a silver-reinforced glass ionomer material (cermet) with a resin-modified glass ionomer in minimal Class II preparations in primary teeth. Matched pairs of primary molars with approximal caries that required operative treatment were used. Each cavity was filled with either Vitremer or Ketac-Silver. The restorations were followed for at least 36 months and examined annually using bitewing radiographs and clinical inspections. Impressions were taken at each recall and models were examined microscopically. After 36 months, one of the resin-modified glass ionomer (RMGI) restorations and 13 (26.5%) of the silver cermet restorations had failed. The RMGI failed because of secondary caries, while most of the failures of the silver cermet fillings were marginal defects alone or in combination with secondary caries. The median survival time (MST) for the silver cermet restorations was 37 months. The RMGI restorations had a MST exceeding 42 months, but MST could not be calculated exactly because of the low failure rate during the study period. The resin-modified glass ionomer had the overall best performance of the two materials under comparison. The silver cermet material cannot be recommended for Class II restorations in primary teeth.

  18. Ionomer-Membrane Water Processing Methods

    NASA Technical Reports Server (NTRS)

    MacCallum, Taber K. (Inventor); Kelsey, Laura (Inventor)

    2016-01-01

    This disclosure provides water processing apparatuses, systems, and methods for recovering water from wastewater such as urine. The water processing apparatuses, systems, and methods can utilize membrane technology for extracting purified water in a single step. A containment unit can include an ionomer membrane, such as Nafion(TradeMark) over a hydrophobic microporous membrane, such as polytetrafluoroethylene (PTFE). The containment unit can be filled with wastewater, and the hydrophobic microporous membrane can be impermeable to liquids and solids of the wastewater but permeable to gases and vapors of the wastewater, and the ionomer membrane can be permeable to water vapor but impermeable to one or more contaminants of the gases and vapors. The containment unit can be exposed to a dry purge gas to maintain a water vapor partial pressure differential to drive permeation of the water vapor, and the water vapor can be collected and processed into potable water.

  19. Ionomer-Membrane Water Processing Apparatus

    NASA Technical Reports Server (NTRS)

    MacCallum, Taber K. (Inventor); Kelsey, Laura (Inventor)

    2016-01-01

    This disclosure provides water processing apparatuses, systems, and methods for recovering water from wastewater such as urine. The water processing apparatuses, systems, and methods can utilize membrane technology for extracting purified water in a single step. A containment unit can include an ionomer membrane, such as Nafion(Registered Trademark), over a hydrophobic microporous membrane, such as polytetrafluoroethylene (PTFE). The containment unit can be filled with wastewater, and the hydrophobic microporous membrane can be impermeable to liquids and solids of the wastewater but permeable to gases and vapors of the wastewater, and the ionomer membrane can be permeable to water vapor but impermeable to one or more contaminants of the gases and vapors. The containment unit can be exposed to a dry purge gas to maintain a water vapor partial pressure differential to drive permeation of the water vapor, and the water vapor can be collected and processed into potable water.

  20. Ionomer-Membrane Water Processing Apparatus

    NASA Technical Reports Server (NTRS)

    MacCallum, Taber K. (Inventor); Kelsey, Laura Katrina (Inventor)

    2017-01-01

    This disclosure provides water processing apparatuses, systems, and methods for recovering water from wastewater such as urine. The water processing apparatuses, systems, and methods can utilize membrane technology for extracting purified water in a single step. A containment unit can include an ionomer membrane, such as Nafion.RTM., over a hydrophobic microporous membrane, such as polytetrafluoroethylene (PTFE). The containment unit can be filled with wastewater, and the hydrophobic microporous membrane can be impermeable to liquids and solids of the wastewater but permeable to gases and vapors of the wastewater, and the ionomer membrane can be permeable to water vapor but impermeable to one or more contaminants of the gases and vapors. The containment unit can be exposed to a dry purge gas to maintain a water vapor partial pressure differential to drive permeation of the water vapor, and the water vapor can be collected and processed into potable water.

  1. Nonequilibrium simulations of model ionomers in an oscillating electric field

    DOE PAGES

    Ting, Christina L.; Sorensen-Unruh, Karen E.; Stevens, Mark J.; ...

    2016-07-25

    Here, we perform molecular dynamics simulations of a coarse-grained model of ionomer melts in an applied oscillating electric field. The frequency-dependent conductivity and susceptibility are calculated directly from the current density and polarization density, respectively. At high frequencies, we find a peak in the real part of the conductivity due to plasma oscillations of the ions. At lower frequencies, the dynamic response of the ionomers depends on the ionic aggregate morphology in the system, which consists of either percolated or isolated aggregates. We show that the dynamic response of the model ionomers to the applied oscillating field can be understoodmore » by comparison with relevant time scales in the systems, obtained from independent calculations.« less

  2. Nonequilibrium simulations of model ionomers in an oscillating electric field

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ting, Christina L.; Sorensen-Unruh, Karen E.; Stevens, Mark J.

    Here, we perform molecular dynamics simulations of a coarse-grained model of ionomer melts in an applied oscillating electric field. The frequency-dependent conductivity and susceptibility are calculated directly from the current density and polarization density, respectively. At high frequencies, we find a peak in the real part of the conductivity due to plasma oscillations of the ions. At lower frequencies, the dynamic response of the ionomers depends on the ionic aggregate morphology in the system, which consists of either percolated or isolated aggregates. We show that the dynamic response of the model ionomers to the applied oscillating field can be understoodmore » by comparison with relevant time scales in the systems, obtained from independent calculations.« less

  3. Electrostatic effects on clustering and ion dynamics in ionomer melts

    NASA Astrophysics Data System (ADS)

    Ma, Boran; Nguyen, Trung; Pryamitsyn, Victor; Olvera de La Cruz, Monica

    An understanding of the relationships between ionomer chain morphology, dynamics and counter-ion mobility is a key factor in the design of ion conducting membranes for battery applications. In this study, we investigate the influence of electrostatic coupling between randomly charged copolymers (ionomers) and counter ions on the structural and dynamic features of a model system of ionomer melts. Using coarse-grained molecular dynamics (CGMD) simulations, we found that variations in electrostatic coupling strength (Γ) remarkably affect the formation of ion-counter ion clusters, ion mobility, and polymer dynamics for a range of charged monomer fractions. Specifically, an increase in Γ leads to larger ionic cluster sizes and reduced polymer and ion mobility. Analysis of the distribution of the radius of gyration of the clusters further reveals that the fractal dimension of the ion clusters is nearly independent from Γ for all the cases studied. Finally, at sufficiently high values of Γ, we observed arrested heterogeneous ions mobility, which is correlated with an increase in ion cluster size. These findings provide insight into the role of electrostatics in governing the nanostructures formed by ionomers.

  4. Surface properties and bond strength measurements of N-vinylcaprolactam (NVC)-containing glass-ionomer cements.

    PubMed

    Moshaverinia, Alireza; Chee, Winston W; Brantley, William A; Schricker, Scott R

    2011-03-01

    N-vinylcaprolactam (NVC)-containing glass ionomers are promising dental restorative materials with improved mechanical properties; however, little information is available on other physical characteristics of these types of modified glass ionomers, especially their surface properties. Understanding the surface characteristics and behavior of glass ionomers is important for understanding their clinical behavior and predictability as dental restorative materials. The purpose of this study was to investigate the effect of NVC-containing terpolymers on the surface properties and bond strength to dentin of GIC (glass-ionomer cement), and to evaluate the effect of NVC-containing terpolymer as a dentin conditioner. The terpolymer of acrylic acid (AA)-itaconic acid (IA)-N-vinylcaprolactam (NVC) with a molar ratio of 8:1:1 (AA:IA:NVC) was synthesized by free radical polymerization and characterized using nuclear magnetic resonance ((1)H-NMR) and Fourier transform infrared spectroscopy (FTIR). The synthesized terpolymer was used in glass-ionomer cement formulations (Fuji IX GP). Ten disc-shaped specimens (12 × 1 mm) were mixed and fabricated at room temperature. Surface properties (wettability) of modified cements were studied by contact angle measurements as a function of time. Work of adhesion values of different surfaces were also determined. The effect of NVC-modified polyacid on the bond strength of glass-ionomer cement to dentin was investigated. The mean data obtained from contact angle and bonding strength measurements were subjected to t test and 2-way ANOVA (α=.05). NVC-modified glass-ionomer cements showed significantly (P<.05) lower contact angles (46 degrees) and higher work of adhesion (W(A)=60.33 erg/cm(2)) in comparison to commercially available Fuji IX GP (57 degrees and W(A)=53.01 erg/cm(2)). The wettability of dentin surfaces conditioned with NVC-containing terpolymer was significantly higher (P<.05) (22 degrees, WA=73.77 erg/cm(2)) than dentin

  5. The effects of boric acid and phosphoric acid on the compressive strength of glass-ionomer cements.

    PubMed

    Prentice, Leon H; Tyas, Martin J; Burrow, Michael F

    2006-01-01

    Both boric acid (H3BO3) and phosphoric acid (H3PO4) are components of dental cements, commonly incorporated into glass (as ingredients in the melt) and occasionally added to the powder or liquid components. This study investigated the effect of boric acid addition to an experimental glass-ionomer powder and the effect of phosphoric acid addition to a glass-ionomer liquid on the 24-h compressive strength. Boric acid powder was added in various concentrations to an experimental glass-ionomer powder and, separately, phosphoric acid was added to an experimental glass-ionomer liquid. Powders and liquids were dosed into capsules at various powder:liquid ratios and cements thus formed were assessed for 24-h compressive strength. Incorporation of boric acid in glass-ionomer powder resulted in a pronounced decrease (p < 0.05 at 1% boric acid) in compressive strength. Addition of phosphoric acid produced initially stronger cements (up to 13% increase at 1% phosphoric acid) before also declining. The incorporation of less than 2% w/w phosphoric acid in glass-ionomer liquids may improve cement strengths without compromising clinical usefulness. The incorporation of boric acid in glass-ionomer cements is contraindicated.

  6. The Plant Ionome Revisited by the Nutrient Balance Concept

    PubMed Central

    Parent, Serge-Étienne; Parent, Léon Etienne; Egozcue, Juan José; Rozane, Danilo-Eduardo; Hernandes, Amanda; Lapointe, Line; Hébert-Gentile, Valérie; Naess, Kristine; Marchand, Sébastien; Lafond, Jean; Mattos, Dirceu; Barlow, Philip; Natale, William

    2013-01-01

    Tissue analysis is commonly used in ecology and agronomy to portray plant nutrient signatures. Nutrient concentration data, or ionomes, belong to the compositional data class, i.e., multivariate data that are proportions of some whole, hence carrying important numerical properties. Statistics computed across raw or ordinary log-transformed nutrient data are intrinsically biased, hence possibly leading to wrong inferences. Our objective was to present a sound and robust approach based on a novel nutrient balance concept to classify plant ionomes. We analyzed leaf N, P, K, Ca, and Mg of two wild and six domesticated fruit species from Canada, Brazil, and New Zealand sampled during reproductive stages. Nutrient concentrations were (1) analyzed without transformation, (2) ordinary log-transformed as commonly but incorrectly applied in practice, (3) additive log-ratio (alr) transformed as surrogate to stoichiometric rules, and (4) converted to isometric log-ratios (ilr) arranged as sound nutrient balance variables. Raw concentration and ordinary log transformation both led to biased multivariate analysis due to redundancy between interacting nutrients. The alr- and ilr-transformed data provided unbiased discriminant analyses of plant ionomes, where wild and domesticated species formed distinct groups and the ionomes of species and cultivars were differentiated without numerical bias. The ilr nutrient balance concept is preferable to alr, because the ilr technique projects the most important interactions between nutrients into a convenient Euclidean space. This novel numerical approach allows rectifying historical biases and supervising phenotypic plasticity in plant nutrition studies. PMID:23526060

  7. The preparation and investigation into properties of ionomer fiber

    NASA Astrophysics Data System (ADS)

    Ejigiri, Everest Emmanuel

    The purpose of this study was to demonstrate the preparation and characterization of ionomer fiber. Two outstanding features of oriented-fiber composites are their high strength-to- weight ratio and controlled anisotropy which is because fibers are formed when polymer chains (in case of polymeric materials) are all lined up in the same direction. And the chains can pack together tightly. Materials can be made into fiber for the purpose of getting better properties and to make the application flexible. In this study, ionomer fiber was prepared. The physical and mechanical properties were examined through a variety of tests- including tensile test, dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), free shape recovery test, and constrained stress recovery test. The ionomer fibers were made into muscles fiber, and the tensile actuation behavior of the muscle was studied. From the DMA, Storage modulus, loss modulus, tan delta and glass transition temperature were obtained. DSC was also used to obtain the glass transition temperature which also closely aligned with glass transition obtained from DMA. Also according to the test results, ionomer fiber (filament) demonstrated considerable stress recovery, high ductility and however, the filament did not produce high recovery ratio. The fiber was made into artificial muscle and actuation test was also carried out, which indicated that because the fiber being too much elastic - the fiber was not able to expand and contract when heat was applied to it. Instead it showed continuous expansion.

  8. Lateral-access Class II restoration using resin-modified glass-ionomer or silver-cermet cement.

    PubMed

    Croll, T P

    1995-02-01

    Direct-access preparation of a carious proximal surface is perhaps the most conservative approach to restoration. Physical properties and handling characteristics of silver amalgam and of resin composite and lack of fluoride ion release make these materials unsuitable for direct buccal- or lingual-access proximal restoration. Insufficient strengths and radiolucency of self-hardening glass-ionomer cements preclude their use for Class II restorations. However, glass-ionomer silver-cermet cement and some resin-modified glass-ionomer materials are proving useful for non-stress-bearing Class II restorations and may have applications in preventive dentistry. This article describes lateral-access Class II restoration with modified glass-ionomer cements. Emphasis is placed on careful handling of materials, maintenance of an ideal operative field, and conservation of tooth structure.

  9. Ionomic screening of field-grown soybeans identifies mutants with altered seed elemental composition

    USDA-ARS?s Scientific Manuscript database

    Soybean seeds contain high levels of mineral nutrients essential for human and animal nutrition. High throughput elemental profiling (ionomics) has identified mutants in model plant species grown in controlled environments. Here, we describe a method for identifying potential soybean ionomics mutant...

  10. Morphologies of precise polyethylene-based acid copolymers and ionomers

    NASA Astrophysics Data System (ADS)

    Buitrago, C. Francisco

    Acid copolymers and ionomers are polymers that contain a small fraction of covalently bound acidic or ionic groups, respectively. For the specific case of polyethylene (PE), acid and ionic pendants enhance many of the physical properties such as toughness, adhesion and rheological properties. These improved properties result from microphase separated aggregates of the polar pendants in the non-polar PE matrix. Despite the widespread industrial use of these materials, rigorous chemical structure---morphology---property relationships remain elusive due to the inevitable structural heterogeneities in the historically-available acid copolymers and ionomers. Recently, precise acid copolymers and ionomers were successfully synthesized by acyclic diene metathesis (ADMET) polymerization. These precise materials are linear, high molecular weight PEs with pendant acid or ionic functional groups separated by a precisely controlled number of carbon atoms. The morphologies of nine precise acid copolymers and eleven precise ionomers were investigated by X-ray scattering, solid-state 13C nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC). For comparison, the morphologies of linear PEs with pseudo-random placement of the pendant groups were also studied. Previous studies of precise copolymers with acrylic acid (AA) found that the microstructural precision produces a new morphology in which PE crystals drive the acid aggregates into layers perpendicular to the chain axes and presumably at the interface between crystalline and amorphous phases. In this dissertation, a second new morphology for acid copolymers is identified in which the aggregates arrange on cubic lattices. The fist report of a cubic morphology was observed at room and elevated temperatures for a copolymer functionalized with two phosphonic acid (PA) groups on every 21st carbon atom. The cubic lattice has been identified as face-centered cubic (FCC). Overall, three morphology types have been

  11. In vitro wear of Ionofil Molar AC quick glass-ionomer cement.

    PubMed

    Abesi, Farida; Safarcherati, Hengameh; Sadati, Javad; Kheirollahi, Hossein

    2011-01-01

    The aim of this study was to evaluate the three-body wear-resistance of one type of restorative glass-ionomer cement (GIC). Specimen including conventional GIC (Ionofil Molar AC Quick: IMACQ), hybrid ionomer (Fuji II LC), and composite resin (Heliomolar) were tested in a wearing machine. In this machine, a 6 kg load was applied via pressable chromium-cobalt bar at 5,000, 10,000, 20,000, 40,000, 80,000, 120,000 cycles. Specimen weight was measured by an electronical weight balance before and after each cycle. Data were analyzed using one-way analysis of variance (ANOVA) followed by a t-test, and a paired t-test at P≤0.05. The highest weight loss has been found in Fuji II LC, then in GIC IMACQ and the least wear rate has been reported in heliomolar composite in all cycles except 120,000 cycles. In 120,000 cycles, the highest weight loss was seen in GIC IMACQ, then Fuji II LC, and finally heliomolar composite. There was a statistically significant difference in weight loss between GIC IMACQ and heliomolar composite (P=0/001). The wear rate of GIC IMACQ was between those of heliomolar composite and Fuji II LC glass ionomer in all cycles except 120,000 cycles. The most important advantage of this new-generation glass ionomer is its good manipulability and also high wear-resistance compared to the hybrid ionomer. Therefore, it is suggested that it can be used as restorative material in class I restorations in primary teeth.

  12. Setting kinetics and mechanical properties of flax fibre reinforced glass ionomer restorative materials

    PubMed Central

    Abou Neel, Ensanya Ali; Young, Anne M.

    2017-01-01

    Regardless of the excellent properties of glass ionomer cements, their poor mechanical properties limit their applications to non-load bearing areas. This study aimed to investigate the effect of incorporated short, chopped and randomly distributed flax fibers (0, 0.5, 1, 2.5, 5 and 25 wt%) on setting reaction kinetics, and mechanical and morphological properties of glass ionomer cements. Addition of flax fibers did not significantly affect the setting reaction extent. According to their content, flax fibers increased the compressive (from 148 to 250 MPa) and flexure strength (from 20 to 42 MPa). They also changed the brittle behavior of glass ionomer cements to a plastic one. They significantly reduced the compressive (from 3 to 1.3 GPa) and flexure modulus (from 19 to 14 GPa). Accordingly, flax fiber-modified glass ionomer cements could be potentially used in high-stress bearing areas. PMID:28808218

  13. In vitro fluoride release from a different kind of conventional and resin modified glass-ionomer cements.

    PubMed

    Selimović-Dragaš, Mediha; Hasić-Branković, Lajla; Korać, Fehim; Đapo, Nermin; Huseinbegović, Amina; Kobašlija, Sedin; Lekić, Meliha; Hatibović-Kofman, Šahza

    2013-08-01

    Fluoride release is important characteristic of glass-ionomer cements. Quantity of fluoride ions released from the glass-ionomer cements has major importance in definition of their biological activity. The objectives of this study were to define the quantity of fluoride ions released from the experimental glass-ionomer cements and to define the effect of fluoride ions released from the experimental glass-ionomer cements on their cytotoxicity. Concentrations of the fluoride ions released in the evaluated glass-ionomer cements were measured indirectly, by the fluoride-selective WTW, F500 electrode potential, combined with reference R503/D electrode. Statistical analyses of F-ion concentrations released by all glass-ionomers evaluated at two time points, after 8 and after 24 hours, show statistically higher fluoride releases from RMGICs: Vitrebond, Fuji II LC and Fuji Plus, when compared to conventional glass-ionomer cements: Fuji Triage, Fuji IX GP Fast and Ketac Silver, both after 8 and after 24 hours. Correlation coefficient between concentrations of fluoride ion released by evaluated glass-ionomer cements and cytotoxic response of UMR-106 osteoblast cell-line are relatively high, but do not reach levels of biological significance. Correlation between concentrations of fluoride ion released and cytotoxic response of NIH3T3 mouse fibroblast cell line after 8 hours is high, positive and statistically significant for conventional GICs, Fuji Triage and Fuji IX GP Fast, and RMGIC, Fuji II LC. Statistically significant Correlation coefficient between concentrations of fluoride ion released and cytotoxic response of NIH3T3 cell line after 24 hours is defined for RMGIC Fuji II LC only.

  14. Controlling ion aggregation and conduction in PEO-based ionomers.

    NASA Astrophysics Data System (ADS)

    Caldwell, David, II; Maranas, Janna

    2015-03-01

    PEO-based ionomers are ideal for reducing concentration polarization found in typical solid polymer electrolytes. This is achieved by binding the anion to the polymer backbone, significantly reducing the anions mobility. Ion aggregation is prevalent in these systems, but their influence on SPE performance is difficult to study experimentally. We present results of molecular dynamics simulations that explore the relationship between ion content and temperature on ion aggregation, polymer motion, and ion conduction. An unforeseen result of ionomers is the creation of string like aggregates that form conduction pathways in the amorphous region. These conduction pathways allow for a partial decoupling of ion conduction with polymer dynamics. The improvement in conductivity through the use of ion aggregates can be quantified by calculating the inverse of the Haven Ratio, dubbed f-value. Typical SPEs have an f-value less than 0.2, while the ionomers of study exhibit f-values near unity or higher. Understanding what properties influence the development and use of these conduction pathways will provide insight for further development of solid polymer electrolytes.

  15. Effect of incorporation of zinc oxide nanoparticles on mechanical properties of conventional glass ionomer cements.

    PubMed

    Panahandeh, Narges; Torabzadeh, Hassan; Aghaee, Mohammadamin; Hasani, Elham; Safa, Saeed

    2018-01-01

    The aim of this study is to investigate the physical properties of conventional and resin-modified glass ionomer cements (GICs) compared to GICs supplemented with zinc oxide (ZnO) nanofiller particles at 5% (w/w). In this in vitro study, ZnO nanoparticles of different morphologies (nanospherical, nanorod, and nanoflower) were incorporated to glass ionomer powder. The samples were subjected to the flexural strength ( n = 20) and surface hardness test ( n = 12) using a universal testing machine and a Vickers hardness machine, respectively. Surface analysis and crystal structure of samples were performed with scanning electron microscope and X-radiation diffraction, respectively. The data were analyzed using one-way ANOVA, Shapiro-Wilk, and Tukey's tests ( P < 0.05). Flexural strength of glass ionomer containing nanoparticles was not significantly different from the control group ( P > 0.05). The surface hardness of the glass ionomer containing nanospherical or nanoflower ZnO was significantly lower than the control group ( P < 0.05). However, the surface hardness of glass ionomer containing nanorod ZnO was not significantly different from the control group ( P = 0.868). Incorporation of nanospherical and nanoflower ZnO to glass ionomer decreased their surface hardness, without any changes on their flexural strength. Incorporation of nanorod ZnO particles caused no effect on the mechanical properties.

  16. In vitro fatigue resistance of glass ionomer cements used in post-and-core applications.

    PubMed

    Gateau, P; Sabek, M; Dailey, B

    2001-08-01

    New glass ionomer cements exhibit better mechanical properties than their older counterparts. However, there is concern about their use as a core material in post-and-core applications. This in vitro study evaluated the fatigue resistance of 2 new glass ionomer cements, Shofu Hi-Dense and Fuji IX GP, and compared their mechanical behavior as a core material under masticatory load with a silver-reinforced glass ionomer (ESPE Ketac-Silver) and a silver amalgam (Cavex Avaloy LC). A total of 100 commercial plastic teeth were divided into 4 groups of 25 specimens each. Titanium posts were placed in the prepared root canals, and cores were built up in amalgam, silver-reinforced glass ionomer cement, and the 2 new glass ionomer cements. The post-and-core specimens were prepared for full cast metal crowns, which were fabricated and cemented with glass ionomer cement. Twenty specimens from each group were placed in a mastication simulator and cyclically loaded with a 400 N force for 1.5 million cycles. The 5 remaining specimens were used as controls. The specimens were sectioned and observed macroscopically and microscopically to determine the number of defects (alterations) in each material. Observed defects were verified with the Kruskal-Wallis test, and the 4 core materials were ranked with the Tukey multiple comparisons test. The mean rank sum values of the defects were as follows: Cavex Avaloy LC Amalgam (16.75), Fuji IX GP (38.50), Shofu Hi-Dense (39.53), and ESPE Ketac-Silver (67.22). The amalgam alloy was significantly different (P< .05) from the others. Under the conditions of this study, the 2 new glass ionomer cements used as core materials showed a higher number of defects than amalgam. These results suggest that their fatigue resistance may be inadequate for post-and-core applications.

  17. Comparative evaluation of microleakage of a carbomer/fluoroapatite-enhanced glass-ionomer cement on primary teeth restorations.

    PubMed

    Tolidis, K; Boutsiouki, C; Gerasimou, P

    2016-09-01

    Carbomer cement represents a novel glass-ionomer which gradually mineralises into fluoroapatite. Purpose of this study was to evaluate microleakage around restorations in deciduous teeth made with composite resin, conventional glass-ionomer cement, resin-modified glass-ionomer cement and carbomer/fluoroapatite-enhanced glass-ionomer cement. A group of 40 primary upper canines, primary upper and lower molars was divided into 4 groups (n=10). Class I cavities were prepared by diamond cylindrical bur at high speed and were restored with a composite resin (Group 1), with a glass- ionomer cement (Group 2), with a resin-modified glass-ionomer cement (Group 3) and with a carbomer/fluoroapatite-enhanced glass- ionomer cement (Group 4). Hard tissue's bonding involved, in the case of composite resin a total etch bonding procedure, and in glass ionomers the use of their respective primers. Restorations were finished and polished. A 24-hour water storage was followed by thermocycling (1500 cycles, 5°C - 36°C - 55°C - 36°C with a dwell time of 15 seconds) and dye penetration test with immersion in 5% methylene blue for 24 hours. In order to assess the degree of microleakage longitudinal cuts were produced by means of a microtome at 0.5 mm and at 1 mm from the restoration margin, and photographs were taken with a stereomicroscope at 100X. Microleakage was classified according to the number of surfaces and the depth at which dye penetration was observed. Data were analysed with ANOVA and post-hoc analysis was performed with Bonferonni test (p<0.05). Statistical analysis exhibited no significant statistical difference between Group 2 and Group 3 (p>0.05). Statistical difference was exhibited between Group 3 and Group 4 (p<0.01), with Group 4 exhibiting lower microleakage values. Group 1 exhibited the lowest mean microleakage values and statistical difference in comparison with all groups (p<0.001). Group 4 exhibited the lowest microleakage values among the cements. Superior

  18. In vitro fluoride release from a different kind of conventional and resin modified glass-ionomer cements

    PubMed Central

    Selimović-Dragaš, Mediha; Hasić-Branković, Lajla; Korać, Fehim; Đapo, Nermin; Huseinbegović, Amina; Kobašlija, Sedin; Lekić, Meliha; Hatibović-Kofman, Šahza

    2013-01-01

    Fluoride release is important characteristic of glass-ionomer cements. Quantity of fluoride ions released from the glass-ionomer cements has major importance in definition of their biological activity. The objectives of this study were to define the quantity of fluoride ions released from the experimental glass-ionomer cements and to define the effect of fluoride ions released from the experimental glass-ionomer cements on their cytotoxicity. Concentrations of the fluoride ions released in the evaluated glass-ionomer cements were measured indirectly, by the fluoride-selective WTW, F500 electrode potential, combined with reference R503/D electrode. Statistical analyses of F-ion concentrations released by all glass-ionomers evaluated at two time points, after 8 and after 24 hours, show statistically higher fluoride releases from RMGICs: Vitrebond, Fuji II LC and Fuji Plus, when compared to conventional glass-ionomer cements: Fuji Triage, Fuji IX GP Fast and Ketac Silver, both after 8 and after 24 hours. Correlation coefficient between concentrations of fluoride ion released by evaluated glass-ionomer cements and cytotoxic response of UMR-106 osteoblast cell-line are relatively high, but do not reach levels of biological significance. Correlation between concentrations of fluoride ion released and cytotoxic response of NIH3T3 mouse fibroblast cell line after 8 hours is high, positive and statistically significant for conventional GICs, Fuji Triage and Fuji IX GP Fast, and RMGIC, Fuji II LC. Statistically significant Correlation coefficient between concentrations of fluoride ion released and cytotoxic response of NIH3T3 cell line after 24 hours is defined for RMGIC Fuji II LC only. PMID:23988173

  19. Effect of Zirconia and Alumina Fillers on the Microstructure and Mechanical Strength of Dental Glass Ionomer Cements

    PubMed Central

    Souza, Júlio C. M.; Silva, Joel B.; Aladim, Andrea; Carvalho, Oscar; Nascimento, Rubens M.; Silva, Filipe S.; Martinelli, Antonio E.; Henriques, Bruno

    2016-01-01

    Background: Glass-ionomer cements perform a protective effect on the dentin-pulp complex considering the F ions release and chemical bonding to the dental structures. On the other hand, those materials have poor physic-mechanical properties in comparison with the restorative resin composite. The main aim of this work was to evaluate the influence of zirconia and/or alumina fillers on the microstructure and strength of a resin modified glass-ionomer cement after thermal cycling. Methods: An in vitro experimental study was carried out on 9 groups (n = 10) of cylindrical samples (6 x 4 mm) made from resin modified glass-ionomer (Vitremer, 3M, USA) with different contents of alumina and/or zirconia fillers. A nano-hybrid resin composite was tested as a control group. Samples were mechanically characterized by axial compressive tests and electron scanning microscopy (SEM) coupled to energy dispersive X-ray spectrophotometry (EDS), before and after thermal cycling. Thermal cycling procedures were performed at 3000, 6000 and 10000 cycles in Fusayama´s artificial saliva at 5 and 60 oC. Results: An improvement of compressive strength was noticed on glass-ionomer reinforced with alumina fillers in comparison with the commercial glass ionomer. SEM images revealed the morphology and distribution of alumina or zirconia in the microstructure of glass-ionomers. Also, defects such as cracks and pores were detected on the glass-ionomer cements. The materials tested were not affected by thermal cycling in artificial saliva. Conclusion: Addition of inorganic particles at nano-scale such as alumina can increase the mechanical properties of glass-ionomer cements. However, the presence of cracks and pores present in glass-ionomer can negatively affect the mechanical properties of the material because they are areas of stress concentration. PMID:27053969

  20. Glass-ionomer-silver-cermet interim Class I restorations for permanent teeth.

    PubMed

    Croll, T P; Killian, C M

    1992-11-01

    Glass-ionomer-silver-cermet cement has proved to be a worthy alternative to silver amalgam for restoring certain Class I lesions in primary teeth. Such restorations are now known to last up to 8 years without need for repair or replacement. Cermet cement has also been used for interim restoration of permanent teeth in special cases, with ideal results. The procedure for placing a glass-ionomer-silver-cermet cement Class I restoration is described.

  1. Comparative evaluation of microleakage of nano-filled resin-modified glass ionomer: An in vitro study

    PubMed Central

    Eronat, Nesrin; Yilmaz, Emir; Kara, Nazan; Topaloglu, Ak Asli

    2014-01-01

    Objective: This in vitro study evaluated the microleakage of a nano-filled resin-modified glass ionomer and a high viscosity glass-ionomer restorations in class V cavities. Materials and Methods: Thirty-two class V cavities prepared on the buccal and lingual surfaces of 16 sound, third molar teeth were randomly assigned into two groups and restored by one of the glass ionomer material; Group A: A high viscosity (Ketac Molar, 3M ESPE) Group B: A nano-filled resin-modified (Ketac N100, 3M ESPE) glass ionomer. One clinician prepared all the cavities. The materials were used according to the manufacturers’ recommendations. The restored teeth were then stored in distilled water at 37°C for 24 h, thermocycled at 5-55°C for 1000 cycles. The specimens were immersed in aqueous solution of Indian ink dye for 48 h at room temperature. They were embedded in resin polyester and sectioned longitudinally in a buccolingual direction. Microleakage was assessed according to the depth of dye penetration along the restoration. The extent of dye penetration at the occlusal and gingival margins was assessed using a stereo microscope. Randomly selected samples from each group were prepared for scanning electron microscope evaluation. The data were statistically analyzed with Friedman and Wilcoxon signed ranks tests. Results: There were statistically significant differences between the microleakage scores of the two groups for both occlusal and gingival scores (P = 0.001). Occlusal and gingival scores for high viscosity glass ionomer (P = 0.024) and nanoionomer (P = 0.021) using Wilcoxon signed ranks tests showed statistically significant differences. High viscosity glass ionomer showed significantly less microleakage compared to the nano-filled resin-modified glass-ionomer (RMGIs) at occlusal margin (P = 0.001). No significant differences were found between the groups at gingival margin (P = 0.0317). Conclusion: Within the limitations of this in vitro study, nano-filled RMGIs

  2. Role of Surface Chemistry on Catalyst/Ionomer Interactions for Transition Metal–Nitrogen–Carbon Electrocatalysts

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Artyushkova, Kateryna; Workman, Michael J.; Matanovic, Ivana

    The role of the interaction between doped carbon-based materials and ionic conductors is essential in multiple technologies, from fuel cells and energy storage devices to conductive polymer composites. In this paper, we report how the surface chemistry of transition metal–nitrogen–carbon (MNC) electrocatalysts affects catalyst–ionomer interaction and the resulting structure of cathodes. The cathode structure resulting from these interactions is directly related to the performance in membrane electrode assembly (MEA) fuel cells. To advance the development of platinum group metal (PGM)-free electrodes for the oxygen reduction reaction it is necessary to understand the structure of the catalyst layers with focus onmore » chemistry and distribution of active sites and ionomer morphology. To assess catalyst interaction with an ionomer, X-ray photoelectron spectroscopy is applied to study the chemistry of catalyst layers while density functional theory (DFT) is used to calculate adsorption energies of the ionomer side chain on different nitrogen species. We report that a high surface concentration of hydrogenated nitrogen at the surface of MNC catalysts causes inefficient ionomer morphology, while an abundance of surface oxides promotes both an efficient distribution of active sites and an optimal ionomer–catalyst interface. The critical role of protonation of nitrogen within catalytic layers in inhibiting proton transport during fuel cell operation is also suggested. As a result, this is the first report of the effect the surface chemistry of MNC catalysts, in the presence of the ionomer, has on the structure and performance of MEA electrodes.« less

  3. Role of Surface Chemistry on Catalyst/Ionomer Interactions for Transition Metal–Nitrogen–Carbon Electrocatalysts

    DOE PAGES

    Artyushkova, Kateryna; Workman, Michael J.; Matanovic, Ivana; ...

    2017-12-18

    The role of the interaction between doped carbon-based materials and ionic conductors is essential in multiple technologies, from fuel cells and energy storage devices to conductive polymer composites. In this paper, we report how the surface chemistry of transition metal–nitrogen–carbon (MNC) electrocatalysts affects catalyst–ionomer interaction and the resulting structure of cathodes. The cathode structure resulting from these interactions is directly related to the performance in membrane electrode assembly (MEA) fuel cells. To advance the development of platinum group metal (PGM)-free electrodes for the oxygen reduction reaction it is necessary to understand the structure of the catalyst layers with focus onmore » chemistry and distribution of active sites and ionomer morphology. To assess catalyst interaction with an ionomer, X-ray photoelectron spectroscopy is applied to study the chemistry of catalyst layers while density functional theory (DFT) is used to calculate adsorption energies of the ionomer side chain on different nitrogen species. We report that a high surface concentration of hydrogenated nitrogen at the surface of MNC catalysts causes inefficient ionomer morphology, while an abundance of surface oxides promotes both an efficient distribution of active sites and an optimal ionomer–catalyst interface. The critical role of protonation of nitrogen within catalytic layers in inhibiting proton transport during fuel cell operation is also suggested. As a result, this is the first report of the effect the surface chemistry of MNC catalysts, in the presence of the ionomer, has on the structure and performance of MEA electrodes.« less

  4. A Comparative Evaluation of Sorption, Solubility, and Compressive Strength of Three Different Glass Ionomer Cements in Artificial Saliva: An in vitro Study

    PubMed Central

    Bhatia, Hind P; Sood, Shveta; Sharma, Naresh

    2017-01-01

    Aim To evaluate and compare the sorption, solubility, and compressive strength of three different glass ionomer cements in artificial saliva - type IX glass ionomer cement, silver-reinforced glass ionomer cement, and zirconia-reinforced glass ionomer cement, so as to determine the material of choice for stress-bearing areas. Materials and methods A total of 90 cylindrical specimens (4 mm diameter and 6 mm height) were prepared for each material following the manufacturer’s instructions. After subjecting the specimens to thermocycling, 45 specimens were immersed in artificial saliva for 24 hours for compressive strength testing under a universal testing machine, and the other 45 were evaluated for sorption and solubility, by first weighing them by a precision weighing scale (W1), then immersing them in artificial saliva for 28 days and weighing them (W2), and finally dehydrating in an oven for 24 hours and weighing them (W3). Results Group III (zirconomer) shows the highest compressive strength followed by group II (Miracle Mix) and least compressive strength is seen in group I (glass ionomer cement type IX-Extra) with statistically significant differences between the groups. The sorption and solubility values in artificial saliva were highest for glass ionomer cement type IX - Extra-GC (group I) followed by zirconomer-Shofu (group III), and the least value was seen for Miracle Mix-GC (group II). Conclusion Zirconia-reinforced glass ionomer cement is a promising dental material and can be used as a restoration in stress-bearing areas due to its high strength and low solubility and sorption rate. It may be a substitute for silver-reinforced glass ionomer cement due to the added advantage of esthetics. Clinical significance This study provides vital information to pediatric dental surgeons on relatively new restorative materials as physical and mechanical properties of the new material are compared with conventional materials to determine the best suited material in

  5. Durability of cermet ionomer cement conditioned in different media.

    PubMed

    el-Din, I M

    1992-01-01

    The glass ionomer cement has exhibited significant adhesion to hard tooth structures, and good cariostatic properties. The sintering of the silver alloy powder and glass ionomer cement "cermet cement" has provided additional improvement in the physical properties of the restorative material. These were flexural resistance, wear resistance, increased radio-opacity, hardness and porosity. The improvement in the physical properties of the cermet glass cements has provided an extension in their clinical use as core build up, lining for inlays, amalgam and composite restoratives, fissure filling, restoration of primary teeth, class II tunnel preparation, treatment of root caries and repair of defective metal margins in crown and inlays.

  6. Sealing ability of cermet ionomer cement as a retrograde filling material.

    PubMed

    Aktener, B O; Pehlivan, Y

    1993-03-01

    An in vitro dye leakage study was performed to compare the sealing ability of high copper amalgam with cavity varnish and cermet ionomer cement with and without varnish when used as retrofilling materials. The root canals of 54 maxillary anterior teeth were instrumented and obturated with gutta-percha and sealer. The apical 3 mm of the roots were resected and apical class I cavity preparations were made. The roots were then randomly divided into three groups and retrofilled with one of the experimental materials. After 72 h of immersion in India ink, the roots were cleared and evaluated for leakage with a stereomicroscope. Statistical analysis indicated that the cermet ionomer cement with varnish group had significantly less leakage than the amalgam group (P < 0.0014) and the cermet ionomer cement without varnish group (P < 0.001). There was no significant difference between the other two groups (P > 0.05).

  7. Heat transfer properties and thermal cure of glass-ionomer dental cements.

    PubMed

    Gavic, Lidia; Gorseta, Kristina; Glavina, Domagoj; Czarnecka, Beata; Nicholson, John W

    2015-10-01

    Under clinical conditions, conventional glass-ionomer dental cements can be cured by application of heat from dental cure lamps, which causes acceleration in the setting. In order for this to be successful, such heat must be able to spread sufficiently through the cement to enhance cure, but not transmit heat so effectively that the underlying dental pulp of the tooth is damaged. The current study was aimed at measuring heat transfer properties of modern restorative glass-ionomers to determine the extent to which they meet these twin requirements. Three commercial glass ionomer cements (Ionofil Molar, Ketac Molar and Equia™ Fill) were used in association with three different light emitting diode cure lamps designed for clinical use. In addition, for each cement, one set of specimens was allowed to cure without application of a lamp. Temperature changes were measured at three different depths (2, 3 and 4 mm) after cure times of 20, 40 and 60 s. The difference among the tested groups was evaluated by ANOVA (P < 0.05) and post hoc Newman-Keuls test. All brands of glass-ionomer showed a small inherent setting exotherm in the absence of heat irradiation, but much greater temperature increases when exposed to the cure lamp. However, temperature rises did not exceed 12.9 °C. Application of the cure lamp led to the establishment of a temperature gradient throughout each specimen. Differences were typically significant (P < 0.05) and did not reflect the nominal power of the lamps, because those lamps have variable cooling systems, and are designed to optimize light output, not heating effect. Because the thermal conductivity of glass-ionomers is low, temperature rises at 4 mm depths were much lower than at 2 mm. At no time did the temperature rise sufficiently to cause concern about potential damage to the pulp.

  8. Are nano-composites and nano-ionomers suitable for orthodontic bracket bonding?

    PubMed

    Uysal, Tancan; Yagci, Ahmet; Uysal, Banu; Akdogan, Gülsen

    2010-02-01

    The aim of this study was to test nano-composite (Filtek Supreme Plus Universal) and a newly introduced nano-ionomer (Ketac N100 Light Curing Nano-Ionomer) restorative to determine their shear bond strength (SBS) and failure site locations in comparison with a conventional light-cure orthodontic bonding adhesive (Transbond XT). Sixty freshly extracted human maxillary premolar teeth were arbitrarily divided into three equal groups. The brackets were bonded to the teeth in each group with different composites, according to the manufacturers' instructions. The SBS values of the brackets were recorded in Megapascals (MPa) using a universal testing machine. Adhesive remnant index scores were determined after failure of the brackets. The data were analysed using analysis of variance, Tukey honestly significant difference, and chi-square tests. The results demonstrated that group 1 (Transbond XT, mean: 12.60 +/- 4.48 MPa) had a higher SBS than that of group 2 (nano-composite, mean: 8.33 +/- 5.16 MPa; P < 0.05) and group 3 (nano-ionomer, mean: 6.14 +/- 2.12 MPa; P < 0.001). No significant differences in debond locations were found among the three groups. Nano-composites and nano-ionomers may be suitable for bonding since they fulfil the previously suggested SBS ranges for clinical acceptability, but they are inferior to a conventional orthodontic composite.

  9. Properties of New Glass Ionomer Restorative Materials Marketed for Stress Bearing Areas

    DTIC Science & Technology

    2018-03-22

    REPORT TYPE 22/03/2018 Poster 4. TITLE AND SUBTITLE Prope1iies of New Glass-Ionomer Restorative Materials Marketed for Stress -Bearing Areas 6...Adobe Professional 7 .0 INTRODUCTION Equia Forte is a new GIC which is marketed for posterior stress bearing restorations due to its newer...research on this and other newer glass ionomer systems being indicated for use in class II posterior stress - bearing preparations. OBJECTIVE The

  10. Improved natural rubber composites reinforced with a complex filler network of biobased nanoparticles and ionomer

    USDA-ARS?s Scientific Manuscript database

    Biobased rubber composites are renewable and sustainable. Significant improvement in modulus of rubber composite reinforced with hydrophilic filler was achieved with the inclusion of ionomers. Soy particles aided with ionomer, carboxylated styrene-butadiene (CSB), formed a strong complex filler netw...

  11. Clinical evaluation of glass ionomer-silver cermet restorations in primary molars: one year results.

    PubMed

    Hung, T W; Richardson, A S

    1990-03-01

    Using the half mouth technique, 33 silver amalgam (Dispersalloy) and 40 glass ionomer (Ketec silver) restorations were placed in the primary molars of children aged five to seven years. After one year, 73 restorations were evaluated. The amalgam restorations rated 90-100 per cent alpha for anatomic form and margins with no recurrent caries or fractures. The glass ionomer restorations rated 35 to 55 per cent alpha for anatomic form and margins with 40 per cent being replaced due to fracture of the material. Within the guidelines of this study, glass ionomer silver cermet was not a suitable material for the restoration of interproximal cavities in primary molars.

  12. The effect of short polyethylene fiber with different weight percentages on diametral tensile strength of conventional and resin modified glass ionomer cements

    PubMed Central

    Sharafeddin, Farahnaz; Ghaboos, Seyed-Ali

    2017-01-01

    Background The aim of this study was to investigate the effect of polyethylene fiber on diametral tensile strength of conventional and resin modified glass ionomer cements. Material and Methods 60 specimens in 6 groups (n=10) were prepared. In group 1 conventional glass ionomer (Fuji GC) and in group 2 resin modified glass ionomer (Fuji LC) were as control groups. In group 3 and 4 conventional glass ionomers mixed with short polyethylene fibers in proportion of 1 wt% and 3 wt%, respectively. In fifth and sixth groups, resin modified glass ionomer and short polyethylene fibers were mixed in 1 and 3% wt, respectively. Samples were prepared in a round brass mold (6.5×2.5 mm). After thermo-cycling, the diametral tensile strength of the specimens were tested and data were analyzed with ANOVA and post-hoc tests (p<0.05). Results Diametral tensile strength of both conventional and resin modified glass ionomer cements increased after mixing with polyethylene fiber (p<0.001). Also, reinforcement occurred as the mixing percentage increased from 1% wt to 3% wt in either conventional and resin modified glass ionomer (p<0.001). Conclusions The polyethylene fiber was shown to have a significant positive influence on diametral tensile strength of two types of glass ionomers. Key words:Conventional glass ionomer, diametral tensile strength, polyethylene fiber, resin modified glass ionomer. PMID:28298993

  13. Ionome changes in Xylella fastidiosa-infected Nicotiana tabacum correlate with virulence and discriminate between subspecies of bacterial isolates.

    PubMed

    Oliver, J E; Sefick, S A; Parker, J K; Arnold, T; Cobine, P A; De La Fuente, L

    2014-10-01

    Characterization of ionomes has been used to uncover the basis of nutrient utilization and environmental adaptation of plants. Here, ionomic profiles were used to understand the phenotypic response of a plant to infection by genetically diverse isolates of Xylella fastidiosa, a gram-negative, xylem-limited bacterial plant pathogen. In this study, X. fastidiosa isolates were used to infect a common model host (Nicotiana tabacum 'SR1'), and leaf and sap concentrations of eleven elements together with plant colonization and symptoms were assessed. Multivariate statistical analysis revealed that changes in the ionome were significantly correlated with symptom severity and bacterial populations in host petioles. Moreover, plant ionome modification by infection could be used to differentiate the X. fastidiosa subspecies with which the plant was infected. This report establishes host ionome modification as a phenotypic response to infection.

  14. Antibacterial activity of resin adhesives, glass ionomer and resin-modified glass ionomer cements and a compomer in contact with dentin caries samples.

    PubMed

    Herrera, M; Castillo, A; Bravo, M; Liébana, J; Carrión, P

    2000-01-01

    A total of 103 clinical samples of carious dentin were used to study the antibacterial action of different dental resin adhesive materials (Gluma 2000, Syntac, Prisma Universal Bond 3, Scotchbond Multi-Purpose and Prime&Bond 2.0) glass ionomer cements (Ketac-Cem, Ketac-Bond, Ketac-Silver, Ketac-Fil) resin-modified glass ionomer cements (Fuji II LC, Vitremer and Vitrebond) and a compomer (Dyract). The agar plate diffusion method was used for the microbial cultures and a chlorhexidine control. The growth of the caries-producing microorganisms was effectively inhibited by the Vitremer and Vitrebond cements, and to a lesser extent by the Scotchbond Multi-Purpose adhesive system. Overall, there were statistically significant differences in the antibacterial activity of the products tested.

  15. Should we treat the ionome as a combination of individual elements, or should we be deriving novel combined traits?

    PubMed Central

    Baxter, Ivan

    2015-01-01

    It has been more than 10 years since the concept of the ionome, all of the mineral nutrients in a cell tissue or organism, was introduced. In the intervening years, ionomics, high throughput elemental profiling, has been used to analyse over 400 000 samples from at least 10 different organisms. There are now multiple published examples where an ionomics approach has been used to find genes of novel function, find lines or environments that produce foods with altered nutritional profiles, or define gene by environmental effects on elemental accumulation. In almost all of these studies, the ionome has been treated as a collection of independent elements, with the analysis repeated on each measured element. However, many elements share chemical properties, are known to interact with each other, or have been shown to have similar interactions with biological molecules. Accordingly, there is strong evidence from ionomic studies that the elements of the ionome do not behave independently and that combinations of elements should be treated as the phenotypes of interest. In this review, I will consider the evidence that we have for the interdependence of the ionome, some of its causes, methods for incorporating this interdependence into analyses and the benefits, drawbacks, and challenges of taking these approaches. PMID:25711709

  16. Tunnel restorations using glass ionomer or glass cermet: in vitro marginal ridge fracture and microleakage.

    PubMed

    Shetty, R; Munshi, A K

    1996-01-01

    The purpose of this in vitro study was to compare the marginal ridge fracture resistance and microleakage following restorations of partial tunnel preparations using glass ionomer and glass cermet cements. Sixty eight sound premolars were selected for this study and were divided randomly into six groups. A standardized partial tunnel preparation was done on all the teeth except specimens belonging to Group I. The partial tunnel preparations of Groups III & V were restored with glass ionomer and that of Groups IV & VI were restored with glass cermet. The teeth belonging to Groups I, II, III & IV were subjected to marginal ridge fracture resistance testing. The teeth of Groups V & VI were tested for microleakage after immersing them in 5% methylene blue solution for 4 hours. The results indicated that the teeth restored with glass cermet were marginally better than that with glass ionomer in terms of marginal ridge fracture resistance. Both the materials failed to reinforce the marginal ridge to the level of an intact tooth. The microleakage which occurred around both the materials were statistically insignificant, but on comparison glass ionomer showed better results. Hence, glass ionomer is preferred as a restorative material for partial tunnel preparations because of additional inherent advantages like superior esthetics and fluoride leachability.

  17. Influence of citric acid on the surface texture of glass ionomer restorative materials

    PubMed Central

    Reddy, Dappili Swami Ranga; Kumar, Ramachandran Anil; Venkatesan, Sokkalingam Mothilal; Narayan, Gopal Shankar; Duraivel, Dasarathan; Indra, Rajamani

    2014-01-01

    Aim: This study determined the effectiveness of G-coat plus surface protective agent over petroleum jelly on the surface texture of conventional Glass ionomer restorative materials. Materials and Methods: Three chemically cured conventional glass ionomer restorative materials type II, type IX and ketac molar were evaluated in this study. Sixty specimens were made for each restorative material. They were divided into two groups of thirty specimens each. Of the sixty specimens, thirty were coated with G-coat plus (a nano-filler coating) and the rest with petroleum jelly. Thirty samples of both protective coating agents were randomly divided into six groups of five specimens and conditioned in citric acid solutions of differing pH (pH 2, 3, 4, 5, 6 & 7). Each specimen was kept in citric acid for three hours a day, and the rest of time stored in salivary substitute. This procedure was repeated for 8 days. After conditioning, the surface roughness (Ra, μm) of each specimen was measured using a surface profilometer (Taylor & Habson, UK). Data was analyzed using one-way analysis of variance (ANOVA) and Tukey's HSD test at a significance level of 0.05. Results: The surface textures of all the tested glass ionomer restorative materials protected with G-coat plus were not significantly affected by acids at low pH. The surface textures of all the tested glass ionomer restorative materials protected with petroleum jelly coating were significantly affected by acids at low pH. Conclusion: The effects of pH on the surface texture of glass ionomer restoratives are material dependent. Among all the materials tested the surface texture of Type II GIC (Group I) revealed marked deterioration when conditioned in solutions of low pH and was statistically significant. Hence, a protective coating either with G-coat plus or with light polymerized low viscosity unfilled resin adhesives is mandatory for all the glass ionomer restorations to increase the wear resistance of the restorative

  18. Influence of citric acid on the surface texture of glass ionomer restorative materials.

    PubMed

    Reddy, Dappili Swami Ranga; Kumar, Ramachandran Anil; Venkatesan, Sokkalingam Mothilal; Narayan, Gopal Shankar; Duraivel, Dasarathan; Indra, Rajamani

    2014-09-01

    This study determined the effectiveness of G-coat plus surface protective agent over petroleum jelly on the surface texture of conventional Glass ionomer restorative materials. Three chemically cured conventional glass ionomer restorative materials type II, type IX and ketac molar were evaluated in this study. Sixty specimens were made for each restorative material. They were divided into two groups of thirty specimens each. Of the sixty specimens, thirty were coated with G-coat plus (a nano-filler coating) and the rest with petroleum jelly. Thirty samples of both protective coating agents were randomly divided into six groups of five specimens and conditioned in citric acid solutions of differing pH (pH 2, 3, 4, 5, 6 & 7). Each specimen was kept in citric acid for three hours a day, and the rest of time stored in salivary substitute. This procedure was repeated for 8 days. After conditioning, the surface roughness (Ra, μm) of each specimen was measured using a surface profilometer (Taylor & Habson, UK). Data was analyzed using one-way analysis of variance (ANOVA) and Tukey's HSD test at a significance level of 0.05. The surface textures of all the tested glass ionomer restorative materials protected with G-coat plus were not significantly affected by acids at low pH. The surface textures of all the tested glass ionomer restorative materials protected with petroleum jelly coating were significantly affected by acids at low pH. The effects of pH on the surface texture of glass ionomer restoratives are material dependent. Among all the materials tested the surface texture of Type II GIC (Group I) revealed marked deterioration when conditioned in solutions of low pH and was statistically significant. Hence, a protective coating either with G-coat plus or with light polymerized low viscosity unfilled resin adhesives is mandatory for all the glass ionomer restorations to increase the wear resistance of the restorative materials.

  19. Highly water-dispersible, mixed ionic-electronic conducting, polymer acid-doped polyanilines as ionomers for direct methanol fuel cells.

    PubMed

    Murthy, Arun; Manthiram, Arumugam

    2011-06-28

    Highly water-dispersible polymer acid-doped polyanilines have been synthesized and evaluated as an alternative for expensive Nafion ionomers in the anode of direct methanol fuel cells (DMFC). These polymers as ionomers lead to higher performance in single cell DMFC compared to Nafion ionomers due to mixed ionic-electronic conduction, water dispersibility, and co-catalytic activity. This journal is © The Royal Society of Chemistry 2011

  20. Predicted electric-field-induced hexatic structure in an ionomer membrane

    NASA Astrophysics Data System (ADS)

    Allahyarov, Elshad; Taylor, Philip L.

    2009-08-01

    Coarse-grained molecular-dynamics simulations were used to study the morphological changes induced in a Nafion®-like ionomer by the imposition of a strong electric field. We observe the formation of structures aligned along the direction of the applied field. The polar head groups of the ionomer sidechains aggregate into clusters, which then form rodlike formations which assemble into a hexatic array aligned with the direction of the field. Occasionally these lines of sulfonates and protons form a helical structure. Upon removal of the electric field, the hexatic array of rodlike structures persists and has a lower calculated free energy than the original isotropic morphology.

  1. Multivariate Analysis of the Cotton Seed Ionome Reveals a Shared Genetic Architecture

    PubMed Central

    Pauli, Duke; Ziegler, Greg; Ren, Min; Jenks, Matthew A.; Hunsaker, Douglas J.; Zhang, Min; Baxter, Ivan; Gore, Michael A.

    2018-01-01

    To mitigate the effects of heat and drought stress, a better understanding of the genetic control of physiological responses to these environmental conditions is needed. To this end, we evaluated an upland cotton (Gossypium hirsutum L.) mapping population under water-limited and well-watered conditions in a hot, arid environment. The elemental concentrations (ionome) of seed samples from the population were profiled in addition to those of soil samples taken from throughout the field site to better model environmental variation. The elements profiled in seeds exhibited moderate to high heritabilities, as well as strong phenotypic and genotypic correlations between elements that were not altered by the imposed irrigation regimes. Quantitative trait loci (QTL) mapping results from a Bayesian classification method identified multiple genomic regions where QTL for individual elements colocalized, suggesting that genetic control of the ionome is highly interrelated. To more fully explore this genetic architecture, multivariate QTL mapping was implemented among groups of biochemically related elements. This analysis revealed both additional and pleiotropic QTL responsible for coordinated control of phenotypic variation for elemental accumulation. Machine learning algorithms that utilized only ionomic data predicted the irrigation regime under which genotypes were evaluated with very high accuracy. Taken together, these results demonstrate the extent to which the seed ionome is genetically interrelated and predictive of plant physiological responses to adverse environmental conditions. PMID:29437829

  2. Review paper: Role of aluminum in glass-ionomer dental cements and its biological effects.

    PubMed

    Nicholson, John W; Czarnecka, Beata

    2009-11-01

    The role of aluminum in glass-ionomers and resin-modified glass-ionomers for dentistry is reviewed. Aluminum is included in the glass component of these materials in the form of Al(2)O(3) to confer basicity on the glass and enable the glass to take part in the acid-base setting reactions. Results of studies of these reactions by FTIR and magic-angle spinning (MAS)-NMR spectroscopy are reported and the role of aluminum is discussed in detail. Aluminum has been shown to be present in the glasses in predominantly 4-coordination, as well as 5- and 6-coordination, and during setting a proportion of this is converted to 6-coordinate species within the matrix of the cement. Despite this, mature cements may contain detectable amounts of both 4- and 5-coordinate aluminum. Aluminum has been found to be leached from glass-ionomer cements, with greater amounts being released under acidic conditions. It may be associated with fluoride, with which it is known to complex strongly. Aluminum that enters the body via the gastro-intestinal tract is mainly excreted, and only about 1% ingested aluminum crosses the gut wall. Calculation shows that, if a glass-ionomer filling dissolved completely over 5 years, it would add only an extra 0.5% of the recommended maximum intake of aluminum to an adult patient. This leads to the conclusion that the release of aluminum from either type of glass-ionomer cement in the mouth poses a negligible health hazard.

  3. Understanding the Thermal Properties of Precursor-Ionomers to Optimize Fabrication Processes for Ionic Polymer-Metal Composites (IPMCs)

    PubMed Central

    Choi, Kisuk; Olsen, Zakai; Hwang, Taeseon; Nam, Jae-Do

    2018-01-01

    Ionic polymer-metal composites (IPMCs) are one of many smart materials and have ionomer bases with a noble metal plated on the surface. The ionomer is usually Nafion, but recently Aquivion has been shown to be a promising alternative. Ionomers are available in the form of precursor pellets. This is an un-activated form that is able to melt, unlike the activated form. However, there is little study on the thermal characteristics of these precursor ionomers. This lack of knowledge causes issues when trying to fabricate ionomer shapes using methods such as extrusion, hot-pressing, and more recently, injection molding and 3D printing. To understand the two precursor-ionomers, a set of tests were conducted to measure the thermal degradation temperature, viscosity, melting temperature, and glass transition. The results have shown that the precursor Aquivion has a higher melting temperature (240 °C) than precursor Nafion (200 °C) and a larger glass transition range (32–65 °C compared with 21–45 °C). The two have the same thermal degradation temperature (~400 °C). Precursor Aquivion is more viscous than precursor Nafion as temperature increases. Based on the results gathered, it seems that the precursor Aquivion is more stable as temperature increases, facilitating the manufacturing processes. This paper presents the data collected to assist researchers in thermal-based fabrication processes. PMID:29693584

  4. Early reaction kinetics of contemporary glass-ionomer restorative materials.

    PubMed

    Roberts, Howard W; Berzins, David W

    2015-02-01

    To investigate polyalkenoate reaction rates in conventional glass-ionomer cement (GIC) and resin-modified glass ionomer (RMGI) restorative materials using infrared spectroscopy. Nine conventional GIC and six RMGI restorative materials were prepared according to manufacturer's directions and placed on a FTIR (Fourier transform infrared spectroscopy) diamond ATR (attenuated total reflectance) surface. FTIR spectra (700 to 1800 cm-1) were obtained each minute for 3 h. VLC specimens were light polymerized after 1 min; at 5 min, all samples were covered with gauze saturated with deionized water. Polyalkenoate reaction was determined by measuring area growth (Å/cm-1) between 1375 and 1500 cm-1. Mean peak areas were determined at 5, 15, 30, 90, and 180 min and compared using ANOVA (p = 0.05) RESULTS: For all RMGI materials, VLC polymerization inhibited the polyalkenoate reaction rate. Compared to conventional GIC, RMGI materials demonstrated less polyalkenoate reaction. Compared to dark curing, RMGI light polymerization significantly inhibited the polyalkenoate reaction rate. The addition of resin components to glass-ionomer products significantly retards and impedes the polyalkenoate reaction. The polyalkenoate reaction rate of RMGI products was significantly lower than that of self-curing GIC restorative materials. Furthermore, light activation of RMGI products further retards the polyalkenoate rate. When clinicians require the therapeutic benefit of a polyalkenoate product, perhaps a conventional GIC restorative product should be the first material of choice.

  5. Mechanical performance of encapsulated restorative glass-ionomer cements for use with Atraumatic Restorative Treatment (ART).

    PubMed

    Molina, Gustavo Fabián; Cabral, Ricardo Juan; Mazzola, Ignacio; Lascano, Laura Brain; Frencken, Jo E

    2013-01-01

    The Atraumatic Restorative Treatment (ART) approach was suggested to be a suitable method to treat enamel and dentine carious lesions in patients with disabilities. The use of a restorative glass-ionomer with optimal mechanical properties is, therefore, very important. To test the null-hypotheses that no difference in diametral tensile, compressive and flexural strengths exists between: (1) The EQUIA system and (2) The Chemfil Rock (encapsulated glass-ionomers; test materials) and the Fuji 9 Gold Label and the Ketac Molar Easymix (hand-mixed conventional glass-ionomers; control materials); (3) The EQUIA system and Chemfil Rock. Specimens for testing flexural (n = 240) and diametral tensile (n=80) strengths were prepared according to standardized specifications; the compressive strength (n=80) was measured using a tooth-model of a class II ART restoration. ANOVA and Tukey B tests were used to test for significant differences between dependent and independent variables. The EQUIA system and Chemfil Rock had significantly higher mean scores for all the three strength variables than the Fuji 9 Gold Label and Ketac Molar Easymix (α=0.05). The EQUIA system had significant higher mean scores for diametral tensile and flexural strengths than the Chemfil Rock (α=0.05). The two encapsulated high-viscosity glass-ionomers had significantly higher test values for diametral tensile, flexural and compressive strengths than the commonly used hand-mixed high-viscosity glass-ionomers.

  6. A new route to prepare multiresponsive organogels from a block ionomer via charge-driven assembly.

    PubMed

    Zhang, Tao; Guo, Qipeng

    2013-06-04

    We report a novel route to prepare multiresponsive organogels through charge-driven assembly between a block ionomer and a diblock copolymer. The ionic complex aggregates to form spherical cores, which are connected by the middle block of the block ionomer to form gels. The organogels are responsive to acids, amines and salts.

  7. Evaluation of stainless steel crowns cemented with glass-ionomer and resin-modified glass-ionomer luting cements.

    PubMed

    Yilmaz, Yucel; Simsek, Sera; Dalmis, Anya; Gurbuz, Taskin; Kocogullari, M Elcin

    2006-04-01

    To evaluate in vitro and in vivo conditions of stainless steel crowns (SSC) cemented using one luting glass-ionomer cement (Aqua Meron) and one luting resin-modified glass-ionomer cement (Vitremer). In the in vitro part of this study, retentive properties of SSCs cemented using Aqua Meron and Vitremer on extracted primary first molars were tested. In addition, two specimens of each group were used to evaluate the tooth hard tissue-cement, within the cement itself, cement-SSC, and tooth hard tissue-cement-SSC under scanning electron microscope (SEM). In the in vivo part of this study, 152 SSCs were placed on the first or second primary molars of 86 children, and cemented using either Aqua Meron or Vitremer. The crowns were examined for retention. In addition, the clinical views of the crowns were recorded with an intraoral camera. No significant difference was found between the mean retentive forces of Aqua Meron and Vitremer (P> 0.05). SSCs cemented with Aqua Meron and Vitremer had an average lifespan of 26.44 and 24.07 months respectively. Only one (0.66%) of 152 SSCs was lost from the Aqua Meron group during post-cementation periods. Nineteen of the 152 SSCs (12.5%) had dents or perforations.

  8. Conjugated ionomers for photovoltaic applications: electric field driven charge separation in organic photovoltaics. Final Technical report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lonergan, Mark

    Final technical report for Conjugated ionomers for photovoltaic applications, electric field driven charge separation in organic photovoltaics. The central goal of the work we completed was been to understand the photochemical and photovoltaic properties of ionically functionalized conjugated polymers (conjugated ionomers or polyelectrolytes) and energy conversion systems based on them. We primarily studied two classes of conjugated polymer interfaces that we developed based either upon undoped conjugated polymers with an asymmetry in ionic composition (the ionic junction) or doped conjugated polymers with an asymmetry in doping type (the p-n junction). The materials used for these studies have primarily been themore » polyacetylene ionomers. We completed a detailed study of p-n junctions with systematically varying dopant density, photochemical creation of doped junctions, and experimental and theoretical work on charge transport and injection in polyacetylene ionomers. We have also completed related work on the use of conjugated ionomers as interlayers that improve the efficiency or organic photovoltaic systems and studied several important aspects of the chemistry of ionically functionalized semiconductors, including mechanisms of so-called "anion-doping", the formation of charge transfer complexes with oxygen, and the synthesis of new polyfluorene polyelectrolytes. We also worked worked with the Haley group at the University of Oregon on new indenofluorene-based organic acceptors.« less

  9. Self-assembly and structural relaxation in a model ionomer melt

    DOE PAGES

    Goswami, Monojoy; Borreguero, Jose M.; Sumpter, Bobby G.

    2015-02-26

    Molecular dynamics simulations are used to understand the self-assembly and structural relaxation in ionomer melts containing less than 10% degree of ionization on the backbone. We study the self-assembly of charged sites and counterions that show structural ordering and agglomeration with a range of structures that can be achieved by changing the dielectric constant of the medium. The intermediate scattering function shows a decoupling of charge and counterion relaxation at longer length scales for only high dielectric constant and at shorter length scales for all dielectric constants. Finally, the slow structural decay of counterions in the strongly correlated ionomer systemmore » closely resembles transport properties of semi-flexible polymers.« less

  10. Should we treat the ionome as a combination of individual elements, or should we be deriving novel combined traits?

    PubMed

    Baxter, Ivan

    2015-04-01

    It has been more than 10 years since the concept of the ionome, all of the mineral nutrients in a cell tissue or organism, was introduced. In the intervening years, ionomics, high throughput elemental profiling, has been used to analyse over 400,000 samples from at least 10 different organisms. There are now multiple published examples where an ionomics approach has been used to find genes of novel function, find lines or environments that produce foods with altered nutritional profiles, or define gene by environmental effects on elemental accumulation. In almost all of these studies, the ionome has been treated as a collection of independent elements, with the analysis repeated on each measured element. However, many elements share chemical properties, are known to interact with each other, or have been shown to have similar interactions with biological molecules. Accordingly, there is strong evidence from ionomic studies that the elements of the ionome do not behave independently and that combinations of elements should be treated as the phenotypes of interest. In this review, I will consider the evidence that we have for the interdependence of the ionome, some of its causes, methods for incorporating this interdependence into analyses and the benefits, drawbacks, and challenges of taking these approaches. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  11. The effect of brushing with nano calcium carbonate and calcium carbonate toothpaste on the surface roughness of nano-ionomer

    NASA Astrophysics Data System (ADS)

    Anisja, D. H.; Indrani, D. J.; Herda, E.

    2017-08-01

    Nanotechnology developments in dentistry have resulted in the development of nano-ionomer, a new restorative material. The surface roughness of restorative materials can increase bacteria adhesion and lead to poor oral hygiene. Abrasive agents in toothpaste can alter tooth and restorative material surfaces. The aim of this study is to identify the effect of brushing with nano calcium carbonate, and calcium carbonate toothpaste on surface roughness of nano-ionomer. Eighteen nano-ionomer specimens were brushed with Aquabidest (doubledistilled water), nano calcium carbonate and calcium carbonate toothpaste. Brushing lasted 30 minutes, and the roughness value (Ra) was measured after each 10 minute segment using a surface roughness tester. The data was analyzed using repeated ANOVA and one-way ANOVA test. The value of nano-ionomer surface roughness increased significantly (p<0.05) after 20 minutes of brushing with the nano calcium carbonate toothpaste. Brushing with calcium carbonate toothpaste leaves nano-ionomer surfaces more rugged than brushing with nano calcium carbonate toothpaste.

  12. Effects of N-vinylcaprolactam containing polyelectrolytes on hardness, fluoride release and water sorption of conventional glass ionomers.

    PubMed

    Moshaverinia, Alireza; Ansari, Sahar; Roohpour, Nima; Reshad, Mamaly; Schricker, Scott R; Chee, Winston Wl

    2011-05-01

    N-vinylcaprolactam (NVC) containing glass ionomers are promising dental restorative materials with improved mechanical properties; however, little information is available on other physical properties of this type of modified glass ionomer, especially their water sorption, fluoride releasing properties and microhardness. The purpose of this study was to investigate the effects of NVC-containing polyelectrolytes on microhardness, fluoride release and water sorption of conventional glass ionomer cements (GIC). The terpolymer of acrylic acid (AA), itaconic acid (IA) and N-vinylcaprolactam (NVC) with 8:1:1 and 7:1:2 (AA: IA: NVC) molar ratios was synthesized by free radical polymerization and characterized using 1H-NMR and FTIR. Experimental GIC specimens were made from a 50% solution of the synthesized terpolymer with Fuji IX powder in a 3.6:1 P/L ratio. Specimens were mixed and fabricated at room temperature. Vickers hardness was determined using a microhardness tester. Water sorption and fluoride releasing properties were also investigated. Commercial Fuji IX was used as the control group. All specimens were first conditioned in distilled water at 37°C for 1 day up to 1 month. Results for the experimental GIC were compared with the control group, using 1-way and 2-way ANOVA and the Tukey multiple range test (α=.05). The NVC-modified GIC exhibited higher mean values of Vickers hardness numbers (VHN). However, the data exhibited no statistically significant differences between the experimental and control groups. The experimental cement (TP2) absorbed significantly more water than the control group (P<.034). Additionally, NVC-containing specimens showed comparable fluoride releasing properties with almost the same fluoride burst and continued fluoride release from the bulk of the material. It was concluded that a hydrophilic monomer such as NVC might be able to increase the water sorption and decrease the amount of initial fluoride release of the glass ionomers

  13. Effects of Pt and ionomer ratios on the structure of catalyst layer: A theoretical model for polymer electrolyte fuel cells

    NASA Astrophysics Data System (ADS)

    Ishikawa, H.; Sugawara, Y.; Inoue, G.; Kawase, M.

    2018-01-01

    The 3D structure of the catalyst layer (CL) in the polymer electrolyte fuel cell (PEFC) is modeled with a Pt/carbon (Pt/C) ratio of 0.4-2.3 and ionomer/carbon (i/C) ratio of 0.5-1.5, and the structural properties are evaluated by numerical simulation. The models are constructed by mimicking the actual shapes of Pt particles and carbon aggregates, as well as the ionomer adhesion in real CLs. CLs with different compositions are characterized by structural properties such as Pt inter-particle distance, ionomer coating thickness, pore size distribution, tortuosity, and ionomer coverage on Pt. The results for Pt/C = 1.0, i/C = 1.0 with Pt loading of 0.3 mg cm-2 and 50% porosity are validated against measured data for CLs with the same composition. With increasing i/C ratio, the smaller pores disappear and the number of isolated pores increases; while the ionomer connection and its coverage on Pt are significantly enhanced at i/C ∼1.0. With increasing Pt/C ratio, the Pt inter-particle distance decreases as the particles connect with each other. The tortuosity of the pores and the ionomer exhibits a trade-off relation depending on the ionomer volume. Further CL design concepts to optimize both O2 diffusion and H+ conduction are discussed.

  14. Mechanical performance of encapsulated restorative glass-ionomer cements for use with Atraumatic Restorative Treatment (ART)

    PubMed Central

    MOLINA, Gustavo Fabián; CABRAL, Ricardo Juan; MAZZOLA, Ignacio; BRAIN LASCANO, Laura; FRENCKEN, Jo. E.

    2013-01-01

    The Atraumatic Restorative Treatment (ART) approach was suggested to be a suitable method to treat enamel and dentine carious lesions in patients with disabilities. The use of a restorative glass-ionomer with optimal mechanical properties is, therefore, very important. Objective: To test the null-hypotheses that no difference in diametral tensile, compressive and flexural strengths exists between: (1) The EQUIA system and (2) The Chemfil Rock (encapsulated glass-ionomers; test materials) and the Fuji 9 Gold Label and the Ketac Molar Easymix (hand-mixed conventional glass-ionomers; control materials); (3) The EQUIA system and Chemfil Rock. Material and Methods: Specimens for testing flexural (n=240) and diametral tensile (n=80) strengths were prepared according to standardized specifications; the compressive strength (n=80) was measured using a tooth-model of a class II ART restoration. ANOVA and Tukey B tests were used to test for significant differences between dependent and independent variables. Results: The EQUIA system and Chemfil Rock had significantly higher mean scores for all the three strength variables than the Fuji 9 Gold Label and Ketac Molar Easymix (α=0.05). The EQUIA system had significant higher mean scores for diametral tensile and flexural strengths than the Chemfil Rock (α=0.05). Conclusion: The two encapsulated high-viscosity glass-ionomers had significantly higher test values for diametral tensile, flexural and compressive strengths than the commonly used hand-mixed high-viscosity glass-ionomers. PMID:23857657

  15. Spheroidization of glass powders for glass ionomer cements.

    PubMed

    Gu, Y W; Yap, A U J; Cheang, P; Kumar, R

    2004-08-01

    Commercial angular glass powders were spheroidized using both the flame spraying and inductively coupled radio frequency plasma spraying techniques. Spherical powders with different particle size distributions were obtained after spheroidization. The effects of spherical glass powders on the mechanical properties of glass ionomer cements (GICs) were investigated. Results showed that the particle size distribution of the glass powders had a significant influence on the mechanical properties of GICs. Powders with a bimodal particle size distribution ensured a high packing density of glass ionomer cements, giving relatively high mechanical properties of GICs. GICs prepared by flame-spheroidized powders showed low strength values due to the loss of fine particles during flame spraying, leading to a low packing density and few metal ions reacting with polyacrylic acid to form cross-linking. GICs prepared by the nano-sized powders showed low strength because of the low bulk density of the nano-sized powders and hence low powder/liquid ratio of GICs.

  16. Size-exclusion chromatography of perfluorosulfonated ionomers.

    PubMed

    Mourey, T H; Slater, L A; Galipo, R C; Koestner, R J

    2011-08-26

    A size-exclusion chromatography (SEC) method in N,N-dimethylformamide containing 0.1 M LiNO(3) is shown to be suitable for the determination of molar mass distributions of three classes of perfluorosulfonated ionomers, including Nafion(®). Autoclaving sample preparation is optimized to prepare molecular solutions free of aggregates, and a solvent exchange method concentrates the autoclaved samples to enable the use of molar-mass-sensitive detection. Calibration curves obtained from light scattering and viscometry detection suggest minor variation in the specific refractive index increment across the molecular size distributions, which introduces inaccuracies in the calculation of local absolute molar masses and intrinsic viscosities. Conformation plots that combine apparent molar masses from light scattering detection with apparent intrinsic viscosities from viscometry detection partially compensate for the variations in refractive index increment. The conformation plots are consistent with compact polymer conformations, and they provide Mark-Houwink-Sakurada constants that can be used to calculate molar mass distributions without molar-mass-sensitive detection. Unperturbed dimensions and characteristic ratios calculated from viscosity-molar mass relationships indicate unusually free rotation of the perfluoroalkane backbones and may suggest limitations to applying two-parameter excluded volume theories for these ionomers. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Fuel cell catalyst layers containing short-side-chain perfluorosulfonic acid ionomers

    NASA Astrophysics Data System (ADS)

    Peron, Jennifer; Edwards, Dave; Haldane, Mark; Luo, Xiaoyan; Zhang, Yongming; Holdcroft, Steven; Shi, Zhiqing

    Porous catalyst layers (CLs) containing short-side-chain (SSC) perfluorosulfonic acid (PFSA) ionomers of different ion exchange capacity (IEC: 1.3, 1.4 and 1.5 meq g -1) were deposited onto Nafion 211 to form catalyst-coated membranes. The porosity of SSC-PFSA-based CLs is larger than Nafion-CL analogues. CLs incorporating SSC ionomer extend the current density of fuel cell polarization curves at elevated temperature and lower relative humidity compared to those based on long-side chain PFSA (e.g., Nafion)-based CLs. Fuel cell polarization performance was greatly improved at 110 °C and 30% relative humidity (RH) when SSC PFSI was incorporated into the catalyst layer.

  18. Class II glass ionomer/silver cermet restorations and their effect on interproximal growth of mutans streptococci.

    PubMed

    Berg, J H; Farrell, J E; Brown, L R

    1990-02-01

    The release of fluoride from glass ionomer materials is one of the most important features of this newly implemented material, and the remineralization effects of this phenomenon have been documented (Hicks and Silverstone 1986). This paper examines the effects of glass ionomer/silver cermet restorations on the plaque levels of interproximal mutans streptococci. Fifteen patients with Class II lesions in primary molars were selected for study. Interproximal plaque samples were obtained from each of the lesion sites and from one caries-free site approximal to a primary molar. One lesion was restored with composite resin to serve as a treated control to the glass ionomer/silver cermet (Ketac Silver, ESPE/Premier Sales Corp., Norristown, Pennsylvania) test site. A sound (unaltered) interproximal site served as the untreated control site. Plaque samples were collected before and at one week, one month, and three months post-treatment. Samples were serially diluted to enable colony counts of mutans streptococci. One week post-treatment counts showed that the glass ionomer/silver cermet restorations significantly reduced (P less than 0.05) the approximal plaque levels of mutans streptococci. Conversely, the untreated and treated control sites did not exhibit reductions in approximal plaque levels of mutans streptococci. These results indicate that glass ionomer restorations may be inhibitory to the growth of mutans streptococci in dental plaque approximal to this restorative material in the primary dentition.

  19. Does Addition of Propolis to Glass Ionomer Cement Alter its Physicomechanical Properties? An in Vitro Study.

    PubMed

    Subramaniam, P; Girish Babu, K L; Neeraja, G; Pillai, S

    Propolis is a natural resinous substance produced by honey bees. The antimicrobial effects of glass ionomer cement have been shown to improve with the addition of propolis; however its effect on the physicomechanical properties of the cement is not known. The purpose of this study was to evaluate the compressive strength and solubility of conventional restorative glass ionomer cement following the addition of propolis. Twenty half cylindrical samples were prepared with conventional restorative glass ionomer cement formed the control group. Another twenty samples were prepared with propolis added to conventional restorative glass ionomer cement formed the experimental group. The compressive strength was assessed using universal testing machine. To assess solubility, the samples were immersed in deionised water at room temperature, for 7 days. The solubility was measured as a difference in the weight of the sample; prior to immersion and following immersion at the end of each day. The control group had a significantly higher mean compressive strength of 146.26 Mpa as compared to the experimental group (135.06 Mpa). The solubility between the groups was significant. In comparison to the control group, incorporation of propolis to conventional restorative glass ionomer cement decreased the compressive strength significantly. The solubility of the cement in the experimental group increased significantly over 7day period as compared to the control group.

  20. Does Addition of Propolis to Glass Ionomer Cement Alter its Physicomechanical Properties? An In Vitro Study.

    PubMed

    Subramaniam, P; Girish Babu, K L; Neeraja, G; Pillai, S

    Propolis is a natural resinous substance produced by honey bees. The antimicrobial effects of glass ionomer cement have been shown to improve with the addition of propolis; however its effect on the physicomechanical properties of the cement is not known. The purpose of this study was to evaluate the compressive strength and solubility of conventional restorative glass ionomer cement following the addition of propolis. Twenty half cylindrical samples were prepared with conventional restorative glass ionomer cement formed the control group. Another twenty samples were prepared with propolis added to conventional restorative glass ionomer cement formed the experimental group. The compressive strength was assessed using universal testing machine. To assess solubility, the samples were immersed in deionised water at room temperature, for 7 days. The solubility was measured as a difference in the weight of the sample; prior to immersion and following immersion at the end of each day. The control group had a significantly higher mean compressive strength of 146.26 Mpa as compared to the experimental group (135.06 Mpa). The solubility between the groups was significant. In comparison to the control group, incorporation of propolis to conventional restorative glass ionomer cement decreased the compressive strength significantly. The solubility of the cement in the experimental group increased significantly over 7day period as compared to the control group.

  1. Autonomous healing materials based on epoxidized natural rubber and ethylene methacrylic acid ionomers

    NASA Astrophysics Data System (ADS)

    Arifur Rahman, Md; Penco, Maurizio; Peroni, Isabella; Ramorino, Giorgio; Janszen, Gerardus; Di Landro, Luca

    2012-03-01

    The development of autonomous healing material has an enormous scientific and technological interest. In this context, this research work deals with the investigation of autonomous healing behavior of epoxidized natural rubber (ENR) and its blends with ethylene methacrylic acid ionomers. The autonomous healing behavior of ENR and its blends containing two different ionomers [poly(ethylene-co-methacrylic acid sodium salt) (EMNa) and poly(ethylene-co-methacrylic acid zinc salt) (EMZn)] has been studied by ballistic puncture tests. Interestingly, EMNa/ENR blends exhibit complete healing just after the ballistic test but EMZn/ENR blends do not show full self-repairing. The healing efficiency has been evaluated by optical microscopy and a depressurized air-flow test. The healing mechanism has been investigated by characterizing thermal and mechanical properties of the blends. The chemical structure studied by FTIR and thermal analysis show that the ion content of ionomers and functionality of ENR has a significant influence on the self-healing behavior.

  2. The diffusion and conduction of lithium in poly(ethylene oxide)-based sulfonate ionomers

    NASA Astrophysics Data System (ADS)

    LaFemina, Nikki H.; Chen, Quan; Colby, Ralph H.; Mueller, Karl T.

    2016-09-01

    Pulsed field gradient nuclear magnetic resonance spectroscopy and dielectric relaxation spectroscopy have been utilized to investigate lithium dynamics within poly(ethylene oxide) (PEO)-based lithium sulfonate ionomers of varying ion content. The ion content is set by the fraction of sulfonated phthalates and the molecular weight of the PEO spacer, both of which can be varied independently. The molecular level dynamics of the ionomers are dominated by either Vogel-Fulcher-Tammann or Arrhenius behavior depending on ion content, spacer length, temperature, and degree of ionic aggregation. In these ionomers the main determinants of the self-diffusion of lithium and the observed conductivities are the ion content and ionic states of the lithium ion, which are profoundly affected by the interactions of the lithium ions with the ether oxygens of the polymer. Since many lithium ions move by segmental polymer motion in the ion pair state, their diffusion is significantly larger than that estimated from conductivity using the Nernst-Einstein equation.

  3. In-plane structuring of proton exchange membrane fuel cell cathodes: Effect of ionomer equivalent weight structuring on performance and current density distribution

    NASA Astrophysics Data System (ADS)

    Herden, Susanne; Riewald, Felix; Hirschfeld, Julian A.; Perchthaler, Markus

    2017-07-01

    Within the active area of a fuel cell inhomogeneous operating conditions occur, however, state of the art electrodes are homogenous over the complete active area. This study uses current density distribution measurements to analyze which ionomer equivalent weight (EW) shows locally the highest current densities. With this information a segmented cathode electrode is manufactured by decal transfer. The segmented electrode shows better performance especially at high current densities compared to homogenous electrodes. Furthermore this segmented catalyst coated membrane (CCM) performs optimal in wet as well as dry conditions, both operating conditions arise in automotive fuel cell applications. Thus, cathode electrodes with an optimized ionomer EW distribution might have a significant impact on future automotive fuel cell development.

  4. Interfacial Shear Strength and Adhesive Behavior of Silk Ionomer Surfaces.

    PubMed

    Kim, Sunghan; Geryak, Ren D; Zhang, Shuaidi; Ma, Ruilong; Calabrese, Rossella; Kaplan, David L; Tsukruk, Vladimir V

    2017-09-11

    The interfacial shear strength between different layers in multilayered structures of layer-by-layer (LbL) microcapsules is a crucial mechanical property to ensure their robustness. In this work, we investigated the interfacial shear strength of modified silk fibroin ionomers utilized in LbL shells, an ionic-cationic pair with complementary ionic pairing, (SF)-poly-l-glutamic acid (Glu) and SF-poly-l-lysine (Lys), and a complementary pair with partially screened Coulombic interactions due to the presence of poly(ethylene glycol) (PEG) segments and SF-Glu/SF-Lys[PEG] pair. Shearing and adhesive behavior between these silk ionomer surfaces in the swollen state were probed at different spatial scales and pressure ranges by using functionalized atomic force microscopy (AFM) tips as well as functionalized colloidal probes. The results show that both approaches were consistent in analyzing the interfacial shear strength of LbL silk ionomers at different spatial scales from a nanoscale to a fraction of a micron. Surprisingly, the interfacial shear strength between SF-Glu and SF-Lys[PEG] pair with partially screened ionic pairing was greater than the interfacial shear strength of the SF-Glu and SF-Lys pair with a high density of complementary ionic groups. The difference in interfacial shear strength and adhesive strength is suggested to be predominantly facilitated by the interlayer hydrogen bonding of complementary amino acids and overlap of highly swollen PEG segments.

  5. Morphological and physical behavior of styrenic, phosphonium-containing ionomers

    NASA Astrophysics Data System (ADS)

    Beyer, Rick; Stokes, Kristoffer

    2010-03-01

    Despite many years of effort, a clear understanding of the factors controlling morphology in Nafion and other ionomers has not been achieved. The increasing need for fuel cell technology continues to drive efforts to develop materials having better performance characteristics even though fundamental structure-property relationships remain unclarified. Alkaline fuel cells (AFCs) present several benefits over proton exchange membrane (PEM) fuel cells, including cost of manufacture (less expensive catalysts) and a significantly shorter path to commercialization. Here we present the most recent findings from our efforts to examine structure-morphology-property relationships for a series of model cationic ionomers. A series of statistical copolymers of styrene and p-vinylbenzyl-trimethyl-phosphonium chloride have been prepared via RAFT polymerization, allowing us to investigate the effect of ion content on physical behavior. Chemical, physical, and morphological characterization has been undertaken using NMR, TGA, DSC, SAXS, and TEM.

  6. Effects of dentin surface treatments on shear bond strength of glass-ionomer cements

    PubMed Central

    Poggio, Claudio; Beltrami, Riccardo; Scribante, Andrea; Colombo, Marco; Lombardini, Marco

    2014-01-01

    Summary Aim The aim of this in vitro study was to evaluate the effect of different surface treatments on shear bond strength of a conventional glass-ionomer cement (GIC) and a resin-modified glass-ionomer cement (RMGIC) to dentin. Materials and methods 80 bovine permanent incisors were used. 40 cylindrical specimens of a GIC (Fuji IX GP Extra) and 40 cylindrical specimens of a RMGIC (Fuji II LC) were attached to the dentin. The teeth were then randomly assigned to 8 groups of equal size (n=10), 4 for every type of glass-ionomer cement, corresponding to type of dentin surface treatments. Group 1: GC Cavity Conditioner; Group 2: 37% phosphoric acid gel; Group 3: Clearfil SE Bond; Group 4: no dentin conditioning (control). The specimens were placed in a universal testing machine (Model 3343, Instron Corp., Canton, Mass., USA) and subsequently tested for shear bond strength (MPa). Results ANOVA showed the presence of significant differences among the various groups. Post hoc Tukey test showed different values of shear bond strength for Fuji IX GP Extra and for Fuji II LC. The different conditioners variably influence the adhesion of the glass-ionomer cements tested. Conclusions. RMGIC shear bond to dentin was higher than GIC. The use of a Self-etch adhesive system improved the shear bond strength values of RMGIC and lowered the shear bond strength values of GIC significantly. PMID:24753797

  7. In vitro microleakage of glass-ionomer composite resin hybrid materials.

    PubMed

    Rodrigues, J A; De Magalhães, C S; Serra, M C; Rodrigues Júnior, A L

    1999-01-01

    The purpose of this study was to evaluate the microleakage of six glass-ionomer composite resin hybrid materials compared with a glass-ionomer cement and a composite resin. Standardized class 5 dentin cavities were prepared on root surfaces of 240 extracted human teeth that were randomly assigned to eight groups and restored using the following restorative systems: (I) Vitremer, (II) Compoglass, (III) Photac-Fil Aplicap, (IV) Variglass, (V) Dyract, (VI) Fuji II LC, (VII) Ketac-Fil Aplicap, and (VIII) Z100. The teeth were thermocycled, placed in a 2% methylene blue solution, and sectioned with diamond disks. Dye penetration was scored on a scale of 0-3. Results showed no significant differences among groups VIII, IV, I, V, VI, III, and II. There were also no significant differences among groups VI, III, II, and VII.

  8. A comparative study of plaque mutans streptococci levels in children receiving glass ionomer cement and amalgam restorations.

    PubMed

    Ertuğrul, Fahinur; Eltem, Rengin; Eronat, Cemal

    2003-01-01

    The restorative materials amalgam (Standalloy F) and glass ionomer cements (Chelon Silver) were comparatively investigated to determine the number of mutans streptococci Saliva and plaque were collected from patients before and 40 days after the insertion of their restorations. Total bateria and mutans streptococci counts were found to be statistically significantly reduced when compared with the prerestoration counts in the saliva samples (P<0.001). Microbiological analysis of the dental plaque showed that the number of mutans streptococci in the glass ionomer cements was significantly lower than in the amalgam restorations (P<0.001). This study showed that silver glass ionomer cements inhibited the growth of mutans streptococci.

  9. Antimicrobial Effects of Dental Luting Glass Ionomer Cements on Streptococcus mutans

    PubMed Central

    Altenburger, Markus; Spitzmüller, Bettina; Anderson, Annette; Hellwig, Elmar

    2014-01-01

    Objective. To reduce secondary caries, glass ionomer luting cements are often used for cementing of indirect restorations. This is because of their well-known antimicrobial potential through the release of fluoride ions. The aim of this in vitro study was to investigate the antimicrobial effect of five dental luting cements which were based on glass ionomer cement technology. Methods. Five different glass ionomer based luting cements were tested for their antimicrobial effects on Streptococcus mutans in two different experimental setups: (i) determination of colony-forming units (CFUs) in a plate-counting assay; (ii) live/dead staining (LDS) and fluorescence microscopy. All experiments were conducted with or without prior treatment of the materials using sterilized human saliva. Antimicrobial effects were evaluated for adherent and planktonic bacteria. Bovine enamel slabs (BES) were used as negative control. BES covered with 0.2% chlorhexidine (CHX) served as positive control. Results. Each of the tested materials significantly reduced the number of initially adhered CFUs; this reduction was even more pronounced after prior incubation in saliva. Antimicrobial effects on adherent bacteria were confirmed by live-dead staining. Conclusion. All five luting cements showed an antimicrobial potential which was increased by prior incubation with human saliva, suggesting an enhanced effect in vivo. PMID:24795539

  10. A Solvent-Vapor Approach toward the Control of Block Ionomer Morphologies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mineart, Kenneth P.; Lee, Byeongdu; Spontak, Richard J.

    Sulfonated block ionomers possess advantageous properties for a wide range of diverse applications such as desalination membranes, fuel cells, electroactive media, and photovoltaic devices. Unfortunately, their inherently high incompatibilities and glass transition temperatures e ff ectively prevent the use of thermal annealing, routinely employed to re fi ne the morphologies of nonionic block copolymers. An alternative approach is therefore required to promote morphological equilibration in block ionomers. The present study explores the morphological characteristics of midblock- sulfonated pentablock ionomers (SBIs) di ff ering in their degree of sulfonation (DOS) and cast from solution followed by solvent-vapor annealing (SVA). Transmission electronmore » microscopy con fi rms that fi lms deposited from di ff erent solvent systems form nonequilibrium morphologies due to solvent-regulated self-assembly and drying. A series of SVA tests performed with solvents varying in polarity reveals that exposing cast fi lms to tetrahydrofuran (THF) vapor for at least 2 h constitutes the most e ff ective SVA protocol, yielding the anticipated equilibrium morphology. That is, three SBI grades subjected to THF-SVA self-assemble into well-ordered lamellae wherein the increase in DOS is accompanied by an increase in lamellar periodicity, as measured by small-angle X-ray scattering.« less

  11. Synthesis and characterization of ionomers as polymer electrolytes for energy conversion devices

    NASA Astrophysics Data System (ADS)

    Oh, Hyukkeun

    Single-ion conducting electrolytes present a unique alternative to traditional binary salt conductors used in lithium-ion batteries. Secondary lithium batteries are considered as one of the leading candidates to replace the combustible engines in automotive technology, however several roadblocks are present which prevent their widespread commercialization. Power density, energy density and safety properties must be improved in order to enable the current secondary lithium battery technology to compete with existing energy technologies. It has been shown theoretically that single-ion electrolytes can eliminate the salt concentration gradient and polarization loss in the cell that develops in a binary salt system, resulting in substantial improvements in materials utilization for high power and energy densities. While attempts to utilize single-ion conducting electrolytes in lithium-ion battery systems have been made, the low ionic conductivities prevented the successful operation of the battery cells in ambient conditions. This work focuses on designing single-ion conducting electrolytes with high ionic conductivities and electrochemical and mechanical stability which enables the stable charge-discharge performance of battery cells. Perfluorosulfonate ionomers are known to possess exceptionally high ionic conductivities due to the electron-withdrawing effect caused by the C-F bonds which stabilizes the negative charge of the anion, leading to a large number of free mobile cations. The effect of perfluorinated sulfonic acid side chains on transport properties of proton exchange membrane polymers was examinated via a comparison of three ionomers, having different side chain structures and a similar polymer backbone. The three different side chain structures were aryl-, pefluoro alkyl-, and alkyl-sulfonic acid groups, respectively. All ionomers were synthesized and characterized by 1H and 19F NMR. A novel ionomer synthesized with a pendant perfluorinated sulfonic acid

  12. Ionomers for Ion-Conducting Energy Materials

    NASA Astrophysics Data System (ADS)

    Colby, Ralph

    For ionic actuators and battery separators, it is vital to utilize single-ion conducting ionomers that avoid the detrimental polarization of other ions. Single-ion conducting ionomers are synthesized based on DFT calculations, with low glass transition temperatures (facile dynamics) to prepare ion-conducting membranes for battery separators that conduct Li+ or Na+. Characterization by X-ray scattering, dielectric spectroscopy, FTIR, NMR and linear viscoelasticity collectively develop a coherent picture of ionic aggregation and both counterion and polymer dynamics. 7Li NMR diffusion measurements find that diffusion is faster than expected by conductivity using the Nernst-Einstein equation, which means that the majority of Li diffusion occurs by ion pairs moving with the polymer segmental motion. Segmental motion only contributes to ionic conduction in the rare event that one of these ion pairs has an extra Li (a positive triple ion). This leads us to a new metric for ion-conducting soft materials, the product of the cation number density p0 and their diffusion coefficient D; p0D is the diffusive flux of lithium ions. This new metric has a maximum at intermediate ion content that corresponds to the overlap of ion pair polarizability volumes. At higher ion contents, the ion pairs interact strongly and form larger aggregation states that retard segmental motion of both mobile ion pairs and triple ions.

  13. Proliferation and morphological transformation of RMK cells exposed to hydroquinine containing ionomers.

    PubMed

    Harvey, Veronica; Benghuzzi, Hamed; Tucci, Michell; Puckett, Aaron; Cason, Zelma

    2002-01-01

    Recent research in our laboratories has been directed towards the development of ionomeric polymers and monomers for use in biomedical applications such as adhesives, drug delivery matrices and tissue scaffolds. The chemical Hydroquinone (HQ) aids as a stabilizer and represents a major component in the development of the ionomers. However, hydroquinone in high concentration has the potential to initiate carcinogenic effects on cells. The curing reactions are based on free radical chemistry that require a radical scavenger, ascorbic acid (Asc) to adjust working and setting times and shelf-life stability. The few studies published on HQ have suggested that high dosages of HQ may stimulate apoptosis as well as an increased cellular leakage, however the effect of HQ on the biocompatability is unknown. Therefore the objectives of this study were to measure the functional capacity, cell proliferation and structural integrity of Rhesus monkey kidney epithelial (RMK) cells exposed to ionomer formulations containing 4 different levels of HQ. A total of 90 tubes of RMK (40,000 cells per tube) cells were divided equally into five equal groups. Group I served as a control and group II-V were subjected to ionomers containing 0, 500, 1000, and 2000 ppm HQ. Cell numbers, morphology, cellular and supermatant MDA levels, and total protein analysis were performed. The results suggest: (I) All ionomer groups increased cellular proliferation except for the 2000 ppm HQ group, (II) MDA levels were increased in cells containing 2000 ppm HQ at 24 hours; and 0 ppm at 48 hours. It may be concluded that HQ concentrations over 1000 ppm may adversely affect biocompatability.

  14. Invitro Evaluation of Fluoride Release from Hydroxyapatite Reinforced Glass Ionomer with or without Protective Coating.

    PubMed

    Tiwari, Shilpi; Nandlal, Bhojraj

    2016-04-01

    Glass Ionomer Cement (GIC) is well known for its fluoride releasing property but has its own drawbacks of poor mechanical properties, sensitivity to initial desiccation and moisture contamination. To overcome these, search led to the reinforcement of hydroxyapatite and application of surface coating agent but their effect on fluoride release is still not clear. To evaluate and compare the release of fluoride from Hydroxyapatite Reinforced Glass Ionomer (HA-GIC) with and without protective coating. Specimens were prepared as follows- Eight percent by weight conventional glass ionomer was replaced by hydroxyapatite powder (HA) and an indigenous product was prepared (HA-GIC). This powder was mixed with liquid of conventional GIC and allowed to set, then G coat plus coating agent was applied in surface coated group and light cured. Fluoride release of the sample was measured every 24 hrs for seven days and weekly from 7(th) to 21(st) day using combination ion selective electrode. Mean values clearly reveal a significant decrease in the fluoride release from day 1 to day 21 for both the groups. Results of repeated measure ANOVA revealed statistically significant difference between two groups (p <0.001). Coating the hydroxyapatite reinforced glass ionomer will allow for slow and steady release of fluoride for a long period of time into oral environment.

  15. Antibacterial activity of glass-ionomer restorative cements exposed to cavity-producing microorganisms.

    PubMed

    Herrera, M; Castillo, A; Baca, P; Carrión, P

    1999-01-01

    The antibacterial activity of the glass-ionomer restorative cements Ketac-Fil, Ketac-Silver, Fuji II LC, and Vitremer was studied in vitro, in conjunction with a total of 32 strains of five bacterial genera that may be associated with dental caries: Streptococcus spp, Lactobacillus spp, Actinomyces spp, Porphyromonas spp, and Clostridium spp. Agar plate diffusion was the method used for the bacterial cultures, which included a chlorhexidine control. All four glass-ionomer cements were found to inhibit bacterial growth, though with noteworthy differences in their spheres of action. Vitremer was the cement determined to have the greatest antibacterial effects, whereas Ketac-Silver presented the least inhibitory action.

  16. Comparative physico-mechanical characterization of new hybrid restorative materials with conventional glass-ionomer and resin composite restorative materials.

    PubMed

    Gladys, S; Van Meerbeek, B; Braem, M; Lambrechts, P; Vanherle, G

    1997-04-01

    The recently developed hybrid restorative materials contain the essential components of conventional glass ionomers and light-cured resins. The objective of this study was to determine several physical and mechanical properties of eight such materials in comparison with two conventional glass ionomers, one micro-filled, and one ultrafine compact-filled resin composite. The two resin composites and two of the three polyacid-modified resin composites could be polished to a higher gloss than the conventional as well as the resin-modified glass ionomers. After abrasion, surface roughness increased for all materials, but not at the same extent, being the least for the conventional resin composites and one polyacid-modified resin composite, Dyract. In contrast to the later resin composites, of which the surface roughness is principally determined by the presence of protruding filler particles above the resin matrix, roughness of conventional and resin-modified glass ionomers results from both protruding filler particles and intruding porosities. The mean particle size of the hybrid restorative materials fell between the smaller mean particle size of the resin composites and the larger one of the conventional glass ionomers. The micro-hardness and Young's modulus values varied substantially among all eight hybrid restorative materials. For all the resin-modified glass-ionomer restorative materials, the Young's modulus reached a maximum value one month after mixing and remained relatively stable thereafter. The Young's modulus of the conventional and the polyacid-modified resin composites decreased slightly after one month. The conventional glass-ionomer materials undoubtedly set the slowest, since their Young's modulus took six months to reach its maximum. The flexural fatigue limit of the hybrid restorative materials is comparable with that of the micro-filled composite. From this investigation, it can be concluded that the physico-mechanical properties vary widely among

  17. Cytotoxicity of dental glass ionomers evaluated using dimethylthiazol diphenyltetrazolium and neutral red tests.

    PubMed

    Lönnroth, E C; Dahl, J E

    2001-02-01

    The purpose of this study was to assess the cytotoxicity of some commonly used glass ionomers. Three chemically cured glass ionomers (Fuji II, Lining cement, and Ketac Silver) and one light-cured (Fuji II LC) were tested. Extracts of mixed non-polymerized materials and polymerized specimens were prepared in accordance with ISO standard 10993-12. The polymerized specimens were cured and placed either directly in the medium (freshly cured), left for 24 h (aged), or aged plus ground before being placed in the medium. The cytotoxicity of extracts was evaluated on mouse fibroblasts (L, 929), using dimethylthiazol diphenyltetrazolium (MTT) and neutral red (NR) assays. Further, the concentrations of aluminum, arsenic and lead were analyzed in aqueous extracts from freshly cured and aged samples, and the fluoride levels analyzed in aqueous extracts from freshly cured samples. All extracts except that of non-polymerized Ketac Silver were rated as severely cytotoxic in both assays. Extracts of polymerized material were significantly more cytotoxic than extracts of non-polymerized material. All freshly cured glass ionomers released aluminum and fluoride concentrations far above what is considered cytotoxic (aluminum >0.2 ppm and fluoride >20 ppm). Extracts from freshly cured Lining Cement contained the highest concentrations of aluminum and fluoride (215 ppm and 112 ppm). Extracts from freshly cured Ketac Silver had the lowest concentrations of aluminum and fluoride but the highest of lead (100 ppm). It can be concluded that all extracts from non-cured, freshly cured, and aged glass ionomers contained cytotoxic levels of substances. Curing did not reduce the toxicity significantly.

  18. Information management

    NASA Technical Reports Server (NTRS)

    Ricks, Wendell; Corker, Kevin

    1990-01-01

    Primary Flight Display (PFD) information management and cockpit display of information management research is presented in viewgraph form. The information management problem in the cockpit, information management burdens, the key characteristics of an information manager, the interface management system handling the flow of information and the dialogs between the system and the pilot, and overall system architecture are covered.

  19. Comparative wear resistance of reinforced glass ionomer restorative materials.

    PubMed

    Yap, A U; Teo, J C; Teoh, S H

    2001-01-01

    This study investigated the wear resistance of three restorative reinforced glass ionomer cements (Fuji IX GP FAST [FJ], Miracle Mix [MM] and Ketac Silver [KS]). Microfilled (Silux [SX]) and mini-filled (Z100 [ZO]) composites were used for comparison. Six specimens were made for each material. The specimens were conditioned for one week in distilled water at 37 degrees C and subjected to wear testing at 20 MPa contact stress against SS304 counterbodies using a reciprocal compression-sliding wear instrumentation. Distilled water was used as lubricant. Wear depth (microm) was measured using profilometry every 2,000 cycles up to 10,000 cycles. Results were analyzed using ANOVA/Scheffe's test (p<0.05). After 10,000 cycles of wear testing, ranking was as follows: KS>ZO>MM>FJ>SX. Wear ranged from 26.1 microm for SX to 71.5 microm for KS. The wear resistance of KS was significantly lower than FJ, MM and SX at all wear intervals. Although KS had significantly more wear than ZO at 2,000 to 6,000 cycles, no significant difference in wear was observed between these two materials at 8,000 and 10,000 cycles. Sintering of silver particles to glass ionomer cement (KS) did not appear to improve wear resistance. The simple addition of amalgam alloy to glass ionomer may improve wear resistance but results in poor aesthetics (silver-black color). FJ, which relies on improved chemistry instead of metal fillers, showed comparable wear resistance to the composites evaluated and is tooth-colored. It may serve as a potential substitute for composites in low-stress situations where fluoride release is desirable and aesthetic requirements are not high.

  20. Evaluation of esthetic parameters of resin-modified glass-ionomer materials and a polyacid-modified resin composite in Class V cervical lesions.

    PubMed

    Gladys, S; Van Meerbeek, B; Lambrechts, P; Vanherle, G

    1999-09-01

    The purpose of this study was to compare the esthetics of 3 resin-modified glass-ionomer materials and 1 polyacid-modified resin composite to the esthetics of a conventional glass-ionomer control material. One hundred eighty-seven Class V cervical restorations were observed clinically over 18 months. The esthetic index system that was used evaluated color match, translucency or opacity, and surface roughness. The tested materials behaved very dissimilarly and inconsistently. In general, the esthetic results of the resin-modified glass-ionomer materials and the polyacid-modified resin composite were far from optimal. The esthetic appearance of restorations seriously deteriorated during clinical service, mainly because of discoloration of margins, changes in translucency and opacity, and rapidly appearing roughness or dullness on the surface. Both the resin-modified glass-ionomer materials and the polyacid-modified resin composite evaluated in this study performed better esthetically than did the conventional glass-ionomer material. Indications for these combination materials are limited to areas where esthetics is not a primary concern but where their ease of application may guarantee a more durable functional result.

  1. Invitro Evaluation of Fluoride Release from Hydroxyapatite Reinforced Glass Ionomer with or without Protective Coating

    PubMed Central

    Nandlal, Bhojraj

    2016-01-01

    Introduction Glass Ionomer Cement (GIC) is well known for its fluoride releasing property but has its own drawbacks of poor mechanical properties, sensitivity to initial desiccation and moisture contamination. To overcome these, search led to the reinforcement of hydroxyapatite and application of surface coating agent but their effect on fluoride release is still not clear. Aim To evaluate and compare the release of fluoride from Hydroxyapatite Reinforced Glass Ionomer (HA-GIC) with and without protective coating. Materials and Methods Specimens were prepared as follows- Eight percent by weight conventional glass ionomer was replaced by hydroxyapatite powder (HA) and an indigenous product was prepared (HA-GIC). This powder was mixed with liquid of conventional GIC and allowed to set, then G coat plus coating agent was applied in surface coated group and light cured. Fluoride release of the sample was measured every 24 hrs for seven days and weekly from 7th to 21st day using combination ion selective electrode. Results Mean values clearly reveal a significant decrease in the fluoride release from day 1 to day 21 for both the groups. Results of repeated measure ANOVA revealed statistically significant difference between two groups (p <0.001). Conclusion Coating the hydroxyapatite reinforced glass ionomer will allow for slow and steady release of fluoride for a long period of time into oral environment. PMID:27190957

  2. Study of the effect of common infusions on glass ionomers using the PIXE and RBS techniques

    NASA Astrophysics Data System (ADS)

    Verón, María Gisela; Pérez, Pablo Daniel; Suárez, Sergio Gabriel; Prado, Miguel Oscar

    2017-12-01

    The effect of four commonly consumed beverages as mineral water, coffee, tea and mate tea on the elemental composition of a commercial glass ionomer was studied using Particle Induced X-ray Emission (PIXE) and Rutherford backscattering (RBS) techniques. We found that after immersion in acidic media, some elements as Al, Si and Na are lost from the glass-ionomer whereas others heavier, as K, Ca and La, increase their concentration at the surface. Although the concentration profiles of Al and Si are different in different media, in all of them the Al:Si ratio was close to unity and remained constant for different periods of immersion in all media. The incorporation of K, Mg and Fe to the surface is found for common infusions while for mineral water the glass-ionomer mainly loses F and Na.The RBS technique showed that immersion in different media produced a modification of the density of the glass ionomer surface layer due to the increment of the concentration of heavier elements at the surface. The thickness of the modified surface layer extends up to 3 μm when the immersion time is seven days and more than 6 μm after 33 days of immersion.

  3. A study of the interactions between glass-ionomer cement and S. sanguis biofilms

    NASA Astrophysics Data System (ADS)

    Hengtrakool, Chanotai

    Glass-ionomer cements (GIC) have been used for dental procedures for many years and more recently in other medical applications such as bone cements, for bone reconstruction and also as drug release agents. The postulated caries-preventive activities of GIC are thought to result from their sealing ability, remineralization potential and antibacterial effects. Extensive 'in vitro' investigations have attempted to quantify these effects. In this study, an artificial mouth model, simulating 'in vivo' conditions at the tooth surface, was used to achieve a better understanding of the interaction of oral bacteria with the cements. This study investigated the interaction of Streptococcus sanguis, a common mouth commensal, with two glass-ionomer formulations (one containing fluoride and the other without fluoride ion) with particular reference to bacterial growth, changes in surface roughness and hardness of the glass-ionomer cement with respect to time. Restorative materials with rough surfaces will promote bacterial accumulation 'in vivo' and plaque formation is one factor in surface degradation. The constant depth film fermenter (CDFF) permits the examination of these phenomena and was used to investigate glass-ionomer/S. sanguis biofilm interaction over periods up to 14 days. In conjunction with these studies, surface roughness was measured using a 3-dimension laser profilometer and the surface hardness evaluated using a micro-indenter. Fluoride release from the cement was measured over 84 days. The results showed that autoclaving the CDFF prior to bacterial innoculate did not appear to affect the long-term fluoride release of the GIC. Laser profilometry revealed that the initial roughness and surface area of the GICs was significantly greater than the hydroxyapatite control. S. sanguis viable counts were significantly reduced for both glass-ionomer formulations in the shortterm, the greater reduction being with fluoride-GIC. S. sanguis biofilms produced similar

  4. Crack closure on rehydration of glass-ionomer materials.

    PubMed

    Sidhu, Sharanbir K; Pilecki, Peter; Sherriff, Martyn; Watson, Timothy F

    2004-10-01

    Moisture-sensitivity of immature glass-ionomer cements suggests that hydration-induced volumetric expansion might close and potentially heal established cracks. Crack closure in glass-ionomer cements (GICs) was observed following rehydration. Circular cavities were prepared in 15 teeth: 10 were restored with resin-modified GICs (5 with Fuji II LC and 5 with Photac-Fil) and 5 were restored with a conventional GIC (Fuji IX); all were dehydrated for 1 min with air and imaged immediately by confocal microscopy. Crack formation in each was located, after which water was placed on the surface and observed for 15 min via a CCD camera. Dehydration caused cracks with measurable gaps, while rehydration resulted in varying degrees of closure: closure was limited in the conventional GIC, and complete or near complete along part/s of the crack in the resin-modified GICs. In all, closure movement became imperceptible after the first 10 min. Statistical analysis indicated no significant difference between the closure behavior of all materials. However, the resin-modified GICs appeared to show a greater potential for closure of established cracks than the conventional GIC upon rehydration.

  5. Ionomer Design, Synthesis and Characterization for Ion-Conducting Energy Materials

    NASA Astrophysics Data System (ADS)

    Colby, Ralph H.

    2013-03-01

    For ionic actuators and battery separators, it is vital to utilize single-ion conductors that avoid the detrimental polarization of other ions; the commonly studied dual-ion conductors simply will not be used in the next generation of materials for these applications. Ab initio quantum chemistry calculations at 0 K in vacuum characterize ion interactions and ion solvation by various functional groups, allowing identification of constituents with weak interactions to be incorporated in ionomers for facile ion transport. Simple ideas for estimating the ion interactions and solvation at practical temperatures and dielectric constants are presented that indicate the rank ordering observed at 0 K in vacuum should be preserved. Hence, such ab initio calculations are useful for screening the plethora of combinations of polymer-ion, counterion and polar functional groups, to decide which are worthy of synthesis for new ionomers. Single-ion conducting ionomers are synthesized based on these calculations, with low glass transition temperatures (facile dynamics) to prepare ion-conducting membranes for ionic actuators and battery separators. Characterization by X-ray scattering, dielectric spectroscopy, NMR and linear viscoelasticity collectively develop a coherent picture of ionic aggregation and both counterion and polymer dynamics. Examples are shown of how ab initio calculations can be used to understand experimental observations of dielectric constant, glass transition temperature and conductivity of polymerized ionic liquids with counterions being either lithium, sodium, fluoride, hydroxide (for batteries) or bulky ionic liquids (for ionic actuators). This work was supported by the Department of Energy under Grant BES-DE-FG02-07ER46409.

  6. Genome-Wide RNAi Ionomics Screen Reveals New Genes and Regulation of Human Trace Element Metabolism

    PubMed Central

    Malinouski, Mikalai; Hasan, Nesrin M.; Zhang, Yan; Seravalli, Javier; Lin, Jie; Avanesov, Andrei; Lutsenko, Svetlana; Gladyshev, Vadim N.

    2017-01-01

    Trace elements are essential for human metabolism and dysregulation of their homeostasis is associated with numerous disorders. Here we characterize mechanisms that regulate trace elements in human cells by designing and performing a genome-wide high-throughput siRNA/ionomics screen, and examining top hits in cellular and biochemical assays. The screen reveals high stability of the ionomes, especially the zinc ionome, and yields known regulators and novel candidates. We further uncover fundamental differences in the regulation of different trace elements. Specifically, selenium levels are controlled through the selenocysteine machinery and expression of abundant selenoproteins; copper balance is affected by lipid metabolism and requires machinery involved in protein trafficking and posttranslational modifications; and the iron levels are influenced by iron import and expression of the iron/heme-containing enzymes. Our approach can be applied to a variety of disease models and/or nutritional conditions, and the generated dataset opens new directions for studies of human trace element metabolism. PMID:24522796

  7. Modification of conventional glass-ionomer cements with N-vinylpyrrolidone containing polyacids, nano-hydroxy and fluoroapatite to improve mechanical properties.

    PubMed

    Moshaverinia, Alireza; Ansari, Sahar; Movasaghi, Zanyar; Billington, Richard W; Darr, Jawwad A; Rehman, Ihtesham U

    2008-10-01

    The objective of this study was to enhance the mechanical strength of glass-ionomer cements, while preserving their unique clinical properties. Copolymers incorporating several different segments including N-vinylpyrrolidone (NVP) in different molar ratios were synthesized. The synthesized polymers were copolymers of acrylic acid and NVP with side chains containing itaconic acid. In addition, nano-hydroxyapatite and fluoroapatite were synthesized using an ethanol-based sol-gel technique. The synthesized polymers were used in glass-ionomer cement formulations (Fuji II commercial GIC) and the synthesized nanoceramic particles (nano-hydroxy or fluoroapatite) were also incorporated into commercial glass-ionomer powder, respectively. The synthesized materials were characterized using FTIR and Raman spectroscopy and scanning electron microscopy. Compressive, diametral tensile and biaxial flexural strengths of the modified glass-ionomer cements were evaluated. After 24h setting, the NVP modified glass-ionomer cements exhibited higher compressive strength (163-167 MPa), higher diametral tensile strength (DTS) (13-17 MPa) and much higher biaxial flexural strength (23-26 MPa) in comparison to Fuji II GIC (160 MPa in CS, 12MPa in DTS and 15 MPa in biaxial flexural strength). The nano-hydroxyapatite/fluoroapatite added cements also exhibited higher CS (177-179 MPa), higher DTS (19-20 MPa) and much higher biaxial flexural strength (28-30 MPa) as compared to the control group. The highest values for CS, DTS and BFS were found for NVP-nanoceramic powder modified cements (184 MPa for CS, 22 MPa for DTS and 33 MPa for BFS) which were statistically higher than control group. It was concluded that, both NVP modified and nano-HA/FA added glass-ionomer cements are promising restorative dental materials with improved mechanical properties.

  8. Laboratory strength of glass ionomer and zinc phosphate cements.

    PubMed

    Piwowarczyk, A; Ottl, P; Lauer, H C

    2001-09-01

    The present in vitro study examined 3 mechanical properties, namely compressive, flexural, and diametral tensile strength, of various commercially available cements and core materials as a function of time after mixing. The examined materials were 2 cermet cements (Ketac Silver [ESPE, Seefeld, Germany] and Chelon Silver [ESPE]), 1 metal-reinforced glass ionomer cement (Miracle Mix [GC Dental Industrial Corp, Tokyo, Japan]), 2 conventional glass ionomer cements (Ketac Bond [ESPE] and Ketac Cem [ESPE]), 1 standard cure zinc phosphate cement (Harvard Cement [Richter and Hoffmann, Berlin, Germany]), and 1 zinc phosphate cement with the addition of 30% silver amalgam alloy powder (Harvard Cement 70% with Dispersalloy 30% [Richter and Hoffmann/Johnson and Johnson, East Windsor, NJ]). Properties were measured using a universal testing machine at 15 minutes, 1 hour, and 24 hours after first mixing. Compressive strengths varied widely between the 3 times of measurement from 5.8 +/- 6.6 MPa for Ketac Cem to 144.3 +/- 10.2 MPa for Ketac Silver. Twenty-four hours after mixing, the Bonferroni test showed significant (p ionomer cement reinforced with sintered glass-silver particles, showed the highest mechanical properties of the examined materials. Copyright 2001 by The American College of Prosthodontists.

  9. Should we treat the ionome as a combination of individual elements, or should we be deriving novel combined traits?

    USDA-ARS?s Scientific Manuscript database

    It has been more than 10 years since the concept of the ionome, all of the mineral nutrients in a cell tissue or organism, was introduced. In the intervening years, ionomics, high throughput elemental profiling, has been used to analyze over 400,000 samples from at least 7 different organisms. There...

  10. Comparison of the push-out shear bond strength of four types of glass ionomers when used to bond amalgam: An in vitro study

    PubMed Central

    Mathew, Vinod Babu; Ramachandran, S; Indira, R; Shankar, P

    2011-01-01

    Background: Dental amalgam is the primary direct posterior restorative material used worldwide, but it have certain shortcomings due to the lack of adhesiveness to the cavity. The introduction of the concept of bonded amalgam helped improve the use of amalgam as a restorative material. Aim: Evaluation of the comparative push-out shear bond strength of four types of conventional glass ionomers used to bond amalgam to tooth in simulated class I situations. Materials and Methods: Four chemical cure glass ionomers are used: GC Fuji I, GC Fuji II, GC Fuji III and GC Fuji VII, and are compared with unbonded amalgam. The push-out bond strength was tested using the Instron Universal Testing Machine at a crosshead speed of 0.5 mm/min. Statistical Analysis: One-way ANOVA and post hoc Bonferroni tests were used to analyze the data. Results: The results showed that the use of glass ionomer to bond amalgam resulted in an increase in the bond strength of amalgam. The Type VII glass ionomer showed the highest bond strength in comparison with the other glass ionomers. Conclusions: Conventional glass ionomer bonds to amalgam and shows a beneficial increase in the bond strength of the restoration in comparison with unbonded amalgam. PMID:22144798

  11. [The effects of topical fluoridation of Ketac Molar Aplicap glass-ionomer material on the growth of cariogenic bacteria contained in the dental plaque].

    PubMed

    Płuciennik-Stronias, Małgorzata; Zarzycka, Beata; Bołtacz-Rzepkowska, Elzbieta

    2013-01-01

    Dental caries is a bacterial disease. The most important element used in caries prevention is fluoride, which is derived from the air, diet or fluoride-containing preparations and materials, e.g. glass-ionomer restorations. Modern fluoride-containing restorative materials are capable of releasing fluoride to the environment. Fluoride can be also accumulated in glass-ionomer cements, thus an attempt was made to saturate these materials with fluoride. The aim of the study was to evaluate the effect of topical fluoridation of Ketac Molar Aplicap glass-ionomer cement on the growth of Lactobacillus spp. in the dental plaque. The study was carried out in 15 patients with good oral hygiene, in whom 35 fillings with conventional glass-ionomer material, Ketac Molar Aplicap, were performed. After 6 months, three-day dental plaque from these fillings was examined. Next, fluoride was rubbed on the glass-ionomer surface and the examination of three-day dental plaque was repeated. No statistically significant differences (p = 0.143) in the amounts of Lactobacillus spp. in the plaque collected prior to and after topical fluoridation were revealed. Fluoride rubbed in the conventional glass-ionomer cement, Ketac Molar Aplicap, did not affect the amount of Lactobacillus spp. in the dental plaque growing on this material.

  12. In vitro biocompatibility tests of glass ionomer cements impregnated with collagen or bioactive glass to fibroblasts.

    PubMed

    Subbarao, C; Neelakantan, P; Subbarao, C V

    2012-01-01

    To evaluate the biocompatibility of glass ionomer cement (GIC) impregnated with collagen or bioactive glass to BHK-21 fibroblasts in vitro. Mineral Trioxide Aggregate was used as the standard for comparison. Human maxillary central incisors (n = 70) were instrumented with a rotary NiTi system and filled. Following resection of the apical 3mm, root end cavities were prepared and restored with conventional GIC (group 1) or GIC with 0.01%, 0.1% or 1% collagen (groups 2, 3, 4 respectively) or, 10%, 30% or 50% bioactive glass (groups 5, 6, 7 respectively), or Mineral Trioxide Aggregate (group 8). The root slices were incubated in tissue culture plates with BHK-21 fibroblast cell line. Phase contrast and scanning electron microscopes were used to score cell quantity, morphology and cell attachment. The data were statistically analyzed by one way ANOVA with Post Hoc Tukey HSD test (p = 0.05). Group 5 showed the highest scores which was significantly higher than all other groups (p < 0.05) except group 8, with which there was no significant difference (p > 0.05). Glass ionomer cement with 10% bioactive glass showed better adhesion and spreading of cells than glass ionomer cement with 0.01% collagen. The biocompatibility of collagen and bioactive glass was concentration dependent. The addition of bioactive glass improved the biocompatibility of glass ionomer cement to fibroblasts better than addition of collagen.

  13. [The effects of Ketac Molar Aplicap glass-ionomer material on growth of cariogenic bacteria contained in the dental plaque].

    PubMed

    Płuciennik-Stronias, Małgorzata; Sakowska, Danuta; Paul-Stalmaszczyk, Małgorzata; Bołtacz-Rzepkowska, Elzbieta

    2012-01-01

    In the aging population, the prevalence of root caries has been observed, which is a characteristic feature of the elderly people. The most important element used in caries prevention is fluoride, which is derived from the air, diet or fluoride-containing preparations and materials, e.g. glass-ionomer restorations. The aim of the study was to evaluate the effect of Ketac Molar Aplicap glass-ionomer on the growth of Lactobacillus sp. bacteria, one of the species most frequently found in the carietic focus of the tooth root. The study was carried out in 15 patients with good oral hygiene, in whom 35 fillings from Ketac Molar Aplicap conventional glass-ionomer material were performed. After 6 months, three-day dental plaque from these fillings and from the tooth enamel of the control group was examined. No statistically significant differences (p = 0.554) in the amounts of Lactobacillus sp. between the study and control group were revealed. Lack of inhibiting effect of glass-ionomer material on the growth of the dental plaque with Lactobacillus sp. after the time of observation is implied.

  14. Synthesis, morphology and dynamics of polyureas and their lithium ionomers

    NASA Astrophysics Data System (ADS)

    Chuayprakong, Sunanta

    Electrolytes currently used in commercial lithium ion batteries have led to leakage and safety issues. Solvent-free solid polymer electrolytes (SPEs) offering high energy density are promising materials for lithium battery applications. SPEs require high modulus to separate the electrodes and suppress lithium dendrite growth. Microphase separation of the hard segments in amorphous polyureas (PUs) yields materials with higher moduli than typical low glass transition temperature (Tg) polymers. In this dissertation, several families of solution polymerized polyether-based PU ionomers were synthesized and their thermal, morphology and dynamic properties characterized as a function of chemical composition. In the initial phase of this investigation, polyethylene oxide (PEO) diamines (with molecular weights = 200, 600, 1050, 2000, 3000 and 6000 g/mol) were polymerized with 4,4' methylene diphenyl diisocyanate (MDI). PUs with 200 and 600 g/mol PEO soft segments are amorphous and single phase. The amorphous PU having 1050 g/mol PEO segments exhibits a small degree of phase separation, as demonstrated by X-ray scattering. PUs with 2000, 3000 and 6000 g/mol PEO soft segments are semicrystalline and their melting points and degrees of crystallinity are lower than those of the precursor PEO diamines due to their attachment to rigid hard segments. Even though polypropylene oxide (PPO) does not dissolve cations as efficiently as PEO, PPO is not crystallizable and was chosen to create a second family of amorphous PUs. PPO-containing diamines ((Jeff400 (MW = 400 g/mol) and Jeff2000 (MW = 2000 g/mol)) and MDI were chosen as the neutral soft segment and the hard segment, respectively. 2,5-diaminobenzene sulfonate was successfully synthesized and used for preparing ionomers. The amount of ionic species in these ionomers was varied and quantified using 1H-NMR. Single Tgs were observed and they increased with increasing ionic content. No X-ray scattering peaks corresponding to

  15. Modifications in Glass Ionomer Cements: Nano-Sized Fillers and Bioactive Nanoceramics

    PubMed Central

    Najeeb, Shariq; Khurshid, Zohaib; Zafar, Muhammad Sohail; Khan, Abdul Samad; Zohaib, Sana; Martí, Juan Manuel Nuñez; Sauro, Salvatore; Matinlinna, Jukka Pekka; Rehman, Ihtesham Ur

    2016-01-01

    Glass ionomer cements (GICs) are being used for a wide range of applications in dentistry. In order to overcome the poor mechanical properties of glass ionomers, several modifications have been introduced to the conventional GICs. Nanotechnology involves the use of systems, modifications or materials the size of which is in the range of 1–100 nm. Nano-modification of conventional GICs and resin modified GICs (RMGICs) can be achieved by incorporation of nano-sized fillers to RMGICs, reducing the size of the glass particles, and introducing nano-sized bioceramics to the glass powder. Studies suggest that the commercially available nano-filled RMGIC does not hold any significant advantage over conventional RMGICs as far as the mechanical and bonding properties are concerned. Conversely, incorporation of nano-sized apatite crystals not only increases the mechanical properties of conventional GICs, but also can enhance fluoride release and bioactivity. By increasing the crystallinity of the set matrix, apatites can make the set cement chemically more stable, insoluble, and improve the bond strength with tooth structure. Increased fluoride release can also reduce and arrest secondary caries. However, due to a lack of long-term clinical studies, the use of nano-modified glass ionomers is still limited in daily clinical dentistry. In addition to the in vitro and in vivo studies, more randomized clinical trials are required to justify the use of these promising materials. The aim of this paper is to review the modification performed in GIC-based materials to improve their physicochemical properties. PMID:27428956

  16. Silk ionomers for encapsulation and differentiation of human MSCs

    PubMed Central

    Calabrese, Rossella; Kaplan, David L.

    2012-01-01

    The response of human bone marrow derived human mesenchymal stem cells (hMSCs) encapsulated in silk ionomer hydrogels was studied. Silk aqueous solutions with silk-poly-L-lysine or silk-poly-L-glutamate were formed into hydrogels via ultrasonication in situ with different net charges. hMSCs were encapsulated within the hydrogels and the impact of matrix charge was assessed over weeks in osteogenic, adipogenic and maintenance growth media. These modified silk charged polymers supported cell viability and proliferative potential, and the hMSCs were able to differentiate toward osteogenic or adipogenic lineages in the corresponding differentiation media. The silk/silk-poly-L-lysine hydrogels exhibited a positive effect on selective osteogenesis of hMSCs, inducing differentiation toward an osteogenic lineage even in the absence of osteogenic supplements, while also inhibiting adipogenesis. In contrast, silk/silk fibroin-poly-L-glutamate hydrogels supported both osteogenic and adipogenic differentiation of hMSCs when cultured under induction conditions. The results demonstrate the potential utility of silk-based ionomers in gel formats for hMSCs encapsulation and for directing hMSCs long term functional differentiation toward specific lineages. PMID:22824008

  17. The effect of a nanofilled resin-based coating on water absorption by teeth restored with glass ionomer.

    PubMed

    Hankins, Amanda D; Hatch, Robert H; Benson, Jarred H; Blen, Bernard J; Tantbirojn, Daranee; Versluis, Antheunis

    2014-04-01

    A nanofilled, resin-based light-cured coating (G-Coat Plus, GC America, Alsip, Ill.) may reduce water absorption by glass ionomers. The authors investigated this possibility by measuring cuspal flexure caused by swelling of glass ionomer-restored teeth. The authors cut large mesio-occlusodistal slots (4-millimeter wide, 4-mm deep) in 12 extracted premolars and restored them with a glass ionomer cement (Fuji IX GP Extra, GC America). Six teeth were coated, and the other six were uncoated controls. The authors digitized the teeth in three dimensions by using an optical scanner after preparation and restoration and during an eight-week storage in water. They calculated cuspal flexure and analyzed the results by using an analysis of variance and Student-Newman-Keuls post hoc tests (significance level .05). They used dye penetration along the interface to verify bonding. Inward cuspal flexure indicated restoration shrinkage. Coated restorations had significantly higher flexure (mean [standard deviation], -11.9 [3.5] micrometers) than did restorations without coating (-7.3 [1.5] μm). Flexure in both groups decreased significantly (P < .05) during water storage and, after eight weeks, it changed to expansion for uncoated control restorations. Dye penetration along the interfaces was not significant, which ruled out debonding as the cause of cuspal relaxation. Teeth restored with glass ionomer cement exhibited shrinkage, as seen by inward cuspal flexure. The effect of the protective coating on water absorption was evident in the slower shrinkage compensation. The study results show that teeth restored with glass ionomers exhibited setting shrinkage that deformed tooth cusps. Water absorption compensated for the shrinkage. Although the coating may be beneficial for reducing water absorption, it also slows the shrinkage compensation rate (that is, the rate that hygroscopic expansion compensates for cuspal flexure from shrinkage).

  18. Morphological and physical characterization of poly(styrene-isobutylene-styrene) block copolymers and ionomers thereof

    NASA Astrophysics Data System (ADS)

    Baugh, Daniel Webster, III

    Poly(styrene-isobutylene-styrene) block copolymers made by living cationic polymerization using a difunctional initiator and the sequential monomer addition technique were analyzed using curve-resolution software in conjunction with high-resolution GPC. Fractional precipitation and selective solvent extraction were applied to a representative sample in order to confirm the identity of contaminating species. The latter were found to be low molecular weight polystyrene homopolymer, diblock copolymer, and higher molecular weight segmented block copolymers formed by intermolecular electrophilic aromatic substitution linking reactions occurring late in the polymerization of the styrene outer blocks. Solvent-cast films of poly(styrene-isobutylene-styrene) (PS-PIB-PS) block copolymers and block ionomers were analyzed using small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). Four block copolymer samples with center block molecular weights of 52,000 g/mol and PS volume fractions (o sbPS) ranging from 0.17 to 0.31 were studied. All samples exhibited hexagonally packed cylinders of PS within the PIB matrix. Cylinder spacing was in the range 32 to 36 nm for most samples, while cylinder diameters varied from 14 to 21 nm. Porod analysis of the scattering data indicated the presence of isolated phase mixing and sharp phase boundaries. PS-PIB-PS block copolymers and ionomers therefrom were analyzed using dynamic mechanical analysis (DMA) and tensile testing. The study encompassed five block copolymer samples with similar PIB center blocks with molecular weights of approx52,000 g/mol and PS weight fractions ranging from 0.127 to 0.337. Ionomers were prepared from two of these materials by lightly sulfonating the PS outer blocks. Sulfonation levels varied from 1.7 to 4.7 mol % and the sodium and potassium neutralized forms were compared to the parent block copolymers. Dynamic mechanical analysis (DMA) of the block copolymer films indicated the existence

  19. Dental Glass Ionomer Cements as Permanent Filling Materials? —Properties, Limitations Future Trends

    PubMed Central

    Lohbauer, Ulrich

    2009-01-01

    Glass ionomer cements (GICs) are clinically attractive dental materials that have certain unique properties that make them useful as restorative and luting materials. This includes adhesion to moist tooth structures and base metals, anticariogenic properties due to release of fluoride, thermal compatibility with tooth enamel, biocompatibility and low toxicity. The use of GICs in a mechanically loaded situation, however, has been hampered by their low mechanical performance. Poor mechanical properties, such as low fracture strength, toughness and wear, limit their extensive use in dentistry as a filling material in stress-bearing applications. In the posterior dental region, glass ionomer cements are mostly used as a temporary filling material. The requirement to strengthen those cements has lead to an ever increasing research effort into reinforcement or strengthening concepts.

  20. Single kernel ionomic profiles are highly heritable indicators of genetic and environmental influences on elemental accumulation in maize grain (Zea mays)

    USDA-ARS?s Scientific Manuscript database

    The ionome, or elemental profile, of a maize kernel represents at least two distinct ideas. First, the collection of elements within the kernel are food, feed and feedstocks for people, animals and industrial processes. Second, the ionome of the kernel represents a developmental end point that can s...

  1. Semicrystalline Ionomer-Metal Carboxylate Composite: Phase Behavior and Mechanical Properties

    NASA Astrophysics Data System (ADS)

    Wakabayashi, Katsuyuki

    2005-03-01

    We have shown previously that the thermal and mechanical behavior of ethylene-methacrylic acid (E-MAA) ionomers can be tuned by the addition of certain magnesium carboxylates, such as magnesium stearate (MgSt). The property modifications result from coassembly of the two components, both co-aggregation of the ionic groups and co-crystallization of the methylene sequences, as revealed by X-ray scattering. When MgSt is replaced by sodium stearate (NaSt), a different suite of mechanical properties is obtained. NaSt, with its high melting and clearing (288 ^oC) points, readily crystallizes out of solution in the molten polymer and forms an effective composite upon cooling from a single-phase melt. The NaSt crystals in the composite resemble the rectangular polymorph in pure NaSt, though with some differences in lattice parameters and transition temperatures due to interaction with the acid groups of the copolymer. The different physical properties of the NaSt vs. MgSt modified ionomers are traced to these microstructural differences, elucidated through a combination of X-ray scattering and microscopy.

  2. Microleakage under orthodontic bands cemented with nano-hydroxyapatite-modified glass ionomer.

    PubMed

    Enan, Enas T; Hammad, Shaza M

    2013-11-01

    To estimate the in vivo effect of nano-hydroxyapatite (HA) modification of banding glass-ionomer cement on microleakage under orthodontic bands. Eighty noncarious premolars scheduled for extraction in 20 orthodontic patients were randomly divided into four groups. Grouping was based on the ratio of nano-HA (0%, 5%, 10%, 15% by weight) added to the luting glass-ionomer cement (GIC) Ketac-Cem, which was used for cementation of prefabricated micro-etched orthodontic bands. Dye penetration method was used for microleakage evaluation at the cement-band and cement-enamel interfaces. Statistical evaluation was performed with a Kruskal-Wallis test and a Mann-Whitney U-test, and a Bonferroni-adjusted significance level was calculated. Bands cemented with conventional GIC showed the highest microleakage scores in comparison to those cemented with nano-HA-modified GIC. No significant difference was found between teeth banded with 10% and 15% modified GIC. Modification of the banding GIC with 15% nano-HA revealed a positive effect on reducing microleakage around orthodontic bands.

  3. Effect of G-Coat Plus on the mechanical properties of glass-ionomer cements.

    PubMed

    Bagheri, R; Taha, N A; Azar, M R; Burrow, M F

    2013-12-01

    Although various mechanical properties of tooth-coloured materials have been described, little data have been published on the effect of ageing and G-Coat Plus on the hardness and strength of the glass-ionomer cements (GICs). Specimens were prepared from one polyacid-modified resin composite (PAMRC; Freedom, SDI), one resin-modified glass-ionomer cement; (RM-GIC; Fuji II LC, GC), and one conventional glass-ionomer cement; (GIC; Fuji IX, GC). GIC and RM-GIC were tested both with and without applying G-Coat Plus (GC). Specimens were conditioned in 37 °C distilled water for either 24 hours, four and eight weeks. Half the specimens were subjected to a shear punch test using a universal testing machine; the remaining half was subjected to Vickers Hardness test. Data analysis showed that the hardness and shear punch values were material dependent. The hardness and shear punch of the PAMRC was the highest and GIC the lowest. Applying the G-Coat Plus was associated with a significant decrease in the hardness of the materials but increase in the shear punch strength after four and eight weeks. The mechanical properties of the restorative materials were affected by applying G-Coat Plus and distilled water immersion over time. The PAMRC was significantly stronger and harder than the RM-GIC or GIC. © 2013 Australian Dental Association.

  4. Marginal adaptation and retention of a glass-ionomer, resin-modified glass-ionomers and a polyacid-modified resin composite in cervical Class-V lesions.

    PubMed

    Gladys, S; Van Meerbeek, B; Lambrechts, P; Vanherle, G

    1998-07-01

    An 18-month follow-up clinical trial of one conventional glass-ionomer (HIFI Master Palette), three resin-modified glass-ionomers (Fuji II LC, Vitremer, 3M Exp. 155) and one polyacid-modified resin composite (Dyract) was conducted to evaluate their clinical effectiveness in Class-V cervical lesions. In addition, the interface between dentin and two resin-modified glass-ionomers and one polyacid-modified resin composite was examined by scanning electron microscopy (SEM). After evaluation of the restorations immediately following placement (baseline), all patients were subjected to a strict recall schedule with controls at 6, 12 and 18 months. The clinical effectiveness was recorded in terms of retention and marginal integrity, clinical microleakage, caries recurrence, and tooth vitality. A chi 2-test (p < 0.05) was used to test for significant differences between materials. In case of restoration loss or special defects, a replica was made to examine the surface texture and restoration margins by SEM. In vitro, the interface was examined by SEM after an argon-ion-beam etching technique was used to enhance surface relief and disclose interfacial substructures. Retention appeared to be good for all the materials tested. Marginal discrepancies were localized at the incisal enamel and/or the cervical dentin margin, except for the polyacid-modified resin composite that showed most of the defects at the incisal enamel margin. None of the systems could guarantee margins free of microleakage for a long time. In vitro, the type of dentin pre-treatment defines to a great extent the morphology of the resultant interface between dentin and the restorative material tested. In this clinical study, the retention rate of the tested materials was good and even excellent for some products. Perfect marginal adaptation deteriorated too fast. The marginal adaptation of the polyacid-modified resin composite at the enamel site would probably have been better by the use of selective enamel

  5. In vitro Characteristics of a Glass Ionomer Cement.

    PubMed

    Driscoll, C L; Green, J D; Beatty, C W; McCaffrey, T V; Marrs, C D

    1998-01-01

    Glass ionomer cements were first described by Wilson and Kent and have been used in dentistry since 1969. It has been recommended for bridging ossicular chain defects, fixation of ossicular chain prosthesis, anchoring of cochlear implants, mastoid obliteration, and repair of tegmen and posterior canal wall defects. The biocompatability and stability of this material over time is vital to its usefulness in neurotologic surgery. The purpose of this study was to assess the stability of a glass ionomer cement in the presence of bacteria and in different pH environments. We demonstrated that bacteria readily adhere to the surface and their presence is associated with accelerated loss of matrix. We found the cement to be susceptible to low pH and to release a visible cloud of debris upon contact with fluid. Calcium concentration in the solution was elevated at all pH levels. Although we are able to demonstrate these findings in vitro the clinical relevance is unclear. There have been several cases of aseptic meningitis possibly due to intracranial release of components of the cement. Until further studies are done use of the cement in contact with cerebral spinal fluid should be avoided. This cement, or a similar material, would be useful in neurotologic surgery but prior to widespread use further testing should be done to assess safety.

  6. Reducing composite restoration polymerization shrinkage stress through resin modified glass-ionomer based adhesives.

    PubMed

    Naoum, S J; Mutzelburg, P R; Shumack, T G; Thode, Djg; Martin, F E; Ellakwa, A E

    2015-12-01

    The aim of this study was to determine whether employing resin modified glass-ionomer based adhesives can reduce polymerization contraction stress generated at the interface of restorative composite adhesive systems. Five resin based adhesives (G Bond, Optibond-All-in-One, Optibond-Solo, Optibond-XTR and Scotchbond-Universal) and two resin modified glass-ionomer based adhesives (Riva Bond-LC, Fuji Bond-LC) were analysed. Each adhesive was applied to bond restorative composite Filtek-Z250 to opposing acrylic rods secured within a universal testing machine. Stress developed at the interface of each adhesive-restorative composite system (n = 5) was calculated at 5-minute intervals over 6 hours. The resin based adhesive-restorative composite systems (RBA-RCS) demonstrated similar interface stress profiles over 6 hours; initial rapid contraction stress development (0-300 seconds) followed by continued contraction stress development ≤0.02MPa/s (300 seconds - 6 hours). The interface stress profile of the resin modified glass-ionomer based adhesive-restorative composite systems (RMGIBA-RCS) differed substantially to the RBA-RCS in several ways. Firstly, during 0-300 seconds the rate of contraction stress development at the interface of the RMGIBA-RCS was significantly (p < 0.05) lower than at the interface of the RBA-RCS. Secondly, at 300 seconds and 6 hours the interface contraction stress magnitude of the RMGIBA-RCS was significantly (p < 0.05) lower than the stress of all assessed RBA-RCS. Thirdly, from 300 seconds to 6 hours both the magnitude and rate of interface stress of the RMGIBA-RCS continued to decline over the 6 hours from the 300 seconds peak. The use of resin modified glass-ionomer based adhesives can significantly reduce the magnitude and rate of polymerization contraction stress developed at the interface of adhesive-restorative composite systems. © 2015 Australian Dental Association.

  7. Heterogeneous Coordination Environments in Lithium-Neutralized Ionomers Identified Using 1H and 7Li MAS NMR

    PubMed Central

    Alam, Todd M.; Jenkins, Janelle E.; Bolintineanu, Dan S.; Stevens, Mark J.; Frischknecht, Amalie L.; Buitrago, C. Francisco; Winey, Karen I.; Opper, Kathleen L.; Wagener, Kenneth B.

    2012-01-01

    The carboxylic acid proton and the lithium coordination environments for precise and random Li-neutralized polyethylene acrylic acid P(E-AA) ionomers were explored using high speed solid-state 1H and 7Li MAS NMR. While the 7Li NMR revealed only a single Li coordination environment, the chemical shift temperature variation was dependent on the precise or random nature of the P(E-AA) ionomer. The 1H MAS NMR revealed two different carboxylic acid proton environments in these materials. By utilizing 1H-7Li rotational echo double resonance (REDOR) MAS NMR experiments, it was demonstrated that the proton environments correspond to different average 1H-7Li distances, with the majority of the protonated carboxylic acids having a close through space contact with the Li. Molecular dynamics simulations suggest that the shortest 1H-7Li distance corresponds to un-neutralized carboxylic acids directly involved in the coordination environment of Li clusters. These solid-state NMR results show that heterogeneous structural motifs need to be included when developing descriptions of these ionomer materials.

  8. A highly aromatic and sulfonated ionomer for high elastic modulus ionic polymer membrane micro-actuators

    NASA Astrophysics Data System (ADS)

    Hatipoglu, Gokhan; Liu, Yang; Zhao, Ran; Yoonessi, Mitra; Tigelaar, Dean M.; Tadigadapa, Srinivas; Zhang, Q. M.

    2012-05-01

    A high modulus, sulfonated ionomer synthesized from 4,6-bis(4-hydroxyphenyl)-N,N-diphenyl-1,3,5-triazin-2-amine and 4,4‧-biphenol with bis(4-fluorophenyl)sulfone (DPA-PS:BP) is investigated for ionic polymer actuators. The uniqueness of DPA-PS:BP is that it can have a high ionic liquid (IL) uptake and consequently generates a high intrinsic strain response, which is >1.1% under 1.6 V while maintaining a high elastic modulus (i.e. 600 MPa for 65 vol% IL uptake). Moreover, such a high modulus of the active ionomer, originating from the highly aromatic backbone and side-chain-free structure, allows for the fabrication of free-standing thin film micro-actuators (down to 5 µm thickness) via the solution cast method and focused-ion-beam milling, which exhibits a much higher bending actuation, i.e. 43 µm tip displacement and 180 kPa blocking stress for a 200 µm long and 5 µm thick cantilever actuator, compared with the ionic actuators based on traditional ionomers such as Nafion, which has a much lower elastic modulus (50 MPa) and actuation strain.

  9. Fluoride release and recharge behavior of a nano-filled resin-modified glass ionomer compared with that of other fluoride releasing materials.

    PubMed

    Mitra, Sumita B; Oxman, Joe D; Falsafi, Afshin; Ton, Tiffany T

    2011-12-01

    To compare the long-term fluoride release kinetics of a novel nano-filled two-paste resin-modified glass-ionomer (RMGI), Ketac Nano (KN) with that of two powder-liquid resin-modified glass-ionomers, Fuji II LC (FLC) and Vitremer (VT) and one conventional glass-ionomer, Fuji IX (FIX). Fluoride release was measured in vitro using ion-selective electrodes. Kinetic analysis was done using regression analysis and compared with existing models for GIs and compomers. In a separate experiment the samples of KN and two conventional glass-ionomers, FIX and Ketac Molar (KM) were subjected to a treatment with external fluoride source (Oral-B Neutra-Foam) after 3 months of fluoride release and the recharge behavior studied for an additional 7-day period. The cumulative amount of fluoride released from KN, VT and FLC and the release profiles were statistically similar but greater than that for FIX at P < 0.05. All four materials, including KN, showed a burst of fluoride ions at shorter times (t) and an overall rate dependence on t1/2 typical for glass-ionomers. The coating of KN with its primer and of DY with its adhesive did not significantly alter the fluoride release behavior of the respective materials. The overall rate for KN was significantly higher than for the compomer DY. DY showed a linear rate of release vs. t and no burst effect as expected for compomers. The nanoionomer KN showed fluoride recharge behavior similar to the conventional glass ionomers FIX and KM. Thus, it was concluded that the new RMGI KN exhibits fluoride ion release behavior similar to typical conventional and RMGIs and that the primer does not impede the release of fluoride.

  10. How mobile are protons in the structure of dental glass ionomer cements?

    NASA Astrophysics Data System (ADS)

    Benetti, Ana R.; Jacobsen, Johan; Lehnhoff, Benedict; Momsen, Niels C. R.; Okhrimenko, Denis V.; Telling, Mark T. F.; Kardjilov, Nikolay; Strobl, Markus; Seydel, Tilo; Manke, Ingo; Bordallo, Heloisa N.

    2015-03-01

    The development of dental materials with improved properties and increased longevity can save costs and minimize discomfort for patients. Due to their good biocompatibility, glass ionomer cements are an interesting restorative option. However, these cements have limited mechanical strength to survive in the challenging oral environment. Therefore, a better understanding of the structure and hydration process of these cements can bring the necessary understanding to further developments. Neutrons and X-rays have been used to investigate the highly complex pore structure, as well as to assess the hydrogen mobility within these cements. Our findings suggest that the lower mechanical strength in glass ionomer cements results not only from the presence of pores, but also from the increased hydrogen mobility within the material. The relationship between microstructure, hydrogen mobility and strength brings insights into the material's durability, also demonstrating the need and opening the possibility for further research in these dental cements.

  11. Influence of glass-ionomer cement on the interface and setting reaction of mineral trioxide aggregate when used as a furcal repair material using laser Raman spectroscopic analysis.

    PubMed

    Nandini, Suresh; Ballal, Suma; Kandaswamy, Deivanayagam

    2007-02-01

    The prolonged setting time of mineral trioxide aggregate (MTA) is the main disadvantage of this material. This study analyzes the influence of glass-ionomer cement on the setting of MTA using laser Raman spectroscopy (LRS). Forty hollow glass molds were taken in which MTA was placed. In Group I specimens, MTA was layered with glass-ionomer cement after 45 minutes. Similar procedures were done for Groups II and III at 4 hours and 3 days, respectively. No glass ionomer was added in Group IV, which were then considered as control samples. Each sample was scanned at various time intervals. At each time interval, the interface between MTA and glass-ionomer cement was also scanned (excluding Group IV). The spectral analysis proved that placement of glass-ionomer cement over MTA after 45 minutes did not affect its setting reaction and calcium salts may be formed in the interface of these two materials.

  12. Push-out bond strength of fiber posts to root dentin using glass ionomer and resin modified glass ionomer cements.

    PubMed

    Pereira, Jefferson Ricardo; Rosa, Ricardo Abreu da; Só, Marcus Vinícius Reis; Afonso, Daniele; Kuga, Milton Carlos; Honório, Heitor Marques; Valle, Accácio Lins do; Vidotti, Hugo Alberto

    2014-01-01

    The purpose of this study was to assess the push-out bond strength of glass fiber posts to root dentin after cementation with glass ionomer (GICs) and resinmodified glass ionomer cements (RMGICs). Fifty human maxillary canines were transversally sectioned at 15 mm from the apex. Canals were prepared with a step back technique until the application of a #55 K-file and filled. Post spaces were prepared and specimens were divided into five groups according to the cement used for post cementation: Luting & Lining Cement; Fuji II LC Improved; RelyX Luting; Ketac Cem; and Ionoseal. After cementation of the glass fiber posts, all roots were stored at 100% humidity until testing. For push-out test, 1-mm thick slices were produced. The push-out test was performed in a universal testing machine at a crosshead speed of 0.5 mm/minute and the values (MPa) were analyzed by Kolmogorov-Smirnov and Levene's tests and by two-way ANOVA and Tukey's post hoc test at a significance level of 5%. Fiber posts cemented using Luting & Lining Cement, Fuji II LC Improved, and Ketac Cem presented the highest bond strength to root dentin, followed by RelyX Luting. Ionoseal presented the lowest bond strength values (P>0.05). The post level did not influence the bond strength of fiber posts to root dentin (P=0.148). The major cause of failure was cohesive at the cement for all GICs and RMGICs. Except for Ionoseal, all cements provided satisfactory bond strength values.

  13. Push-out bond strength of fiber posts to root dentin using glass ionomer and resin modified glass ionomer cements

    PubMed Central

    PEREIRA, Jefferson Ricardo; da ROSA, Ricardo Abreu; SÓ, Marcus Vinícius Reis; AFONSO, Daniele; KUGA, Milton Carlos; HONÓRIO, Heitor Marques; do VALLE, Accácio Lins; VIDOTTI, Hugo Alberto

    2014-01-01

    Objective The purpose of this study was to assess the push-out bond strength of glass fiber posts to root dentin after cementation with glass ionomer (GICs) and resin-modified glass ionomer cements (RMGICs). Material and Methods Fifty human maxillary canines were transversally sectioned at 15 mm from the apex. Canals were prepared with a step back technique until the application of a #55 K-file and filled. Post spaces were prepared and specimens were divided into five groups according to the cement used for post cementation: Luting & Lining Cement; Fuji II LC Improved; RelyX Luting; Ketac Cem; and Ionoseal. After cementation of the glass fiber posts, all roots were stored at 100% humidity until testing. For push-out test, 1-mm thick slices were produced. The push-out test was performed in a universal testing machine at a crosshead speed of 0.5 mm/minute and the values (MPa) were analyzed by Kolmogorov-Smirnov and Levene's tests and by two-way ANOVA and Tukey's post hoc test at a significance level of 5%. Results Fiber posts cemented using Luting & Lining Cement, Fuji II LC Improved, and Ketac Cem presented the highest bond strength to root dentin, followed by RelyX Luting. Ionoseal presented the lowest bond strength values (P>0.05). The post level did not influence the bond strength of fiber posts to root dentin (P=0.148). The major cause of failure was cohesive at the cement for all GICs and RMGICs. Conclusions Except for Ionoseal, all cements provided satisfactory bond strength values. PMID:25004052

  14. A Comparative Evaluation of the Influence of Command Set Methods on Microleakage of Glass Ionomer Cement: An In Vitro Study.

    PubMed

    Punnathara, Sairaj; Krishnakumar, Ramalingam; Govindarajan, Mohan; Kanaran, Momeka; Philip, Sunil Thomas; Nair, Aswin Saseendran; Peter, Joby

    2017-06-01

    A major challenge when using glass ionomer cement in clinical situation particularly in paediatric dentistry is to overcome the problem of microleakage. Fast or command setting of Type IX glass ionomer cement using external energy source enhances the setting reaction and results in improved initial physical and mechanical properties. To compare and evaluate the influence of ultrasonic activation, halogen light irradiation and combined effect of both on microleakage of enamel adjacent to Type IX glass ionomer restorations. For forty premolar teeth, standard Class V cavities prepared were restored with GC Gold Label Type IX glass ionomer cement in vitro. The specimens were randomly divided into four groups: 1) Control group; 2) halogen group; 3) ultrasonic group; 4) ultrasonic with halogen group. The teeth were kept in distilled water for 24 hours. Teeth were exposed to 1500 thermocycles at temperature of 12°C ±2 and 60°C ±2 with alternate immersion in hot and cold water for one minute. First teeth were immersed in dye solution for four hours and then in developing solution for four hours. The samples were sectioned buccolingually through centre of the restorations and degree of dye penetration was assessed under stereomicroscope and scored. One-Way ANOVA model was constructed followed by post-hoc Tukey's test for multiple pair wise comparison of mean values. Statistically significant differences were found in microleakage among the four groups (p<0.001) with respect to dye penetration. Halogen group showed least microleakage followed by control but differences between them were statistically not significant (p>0.05). Similarly the differences between Ultrasonic plus halogen group and ultrasonic group were not significant (p>0.05). The differences between ultrasonic and halogen group were statistically significant (p<0.05). Halogen light decreases the microleakage of enamel adjacent to GC Type IX glass ionomer restorations, when used to accelerate the setting

  15. Microleakage of Glass Ionomer-based Provisional Cement in CAD/CAM-Fabricated Interim Crowns: An in vitro Study.

    PubMed

    Farah, Ra'fat I; Al-Harethi, Naji

    2016-10-01

    The aim of this study was to compare in vitro the marginal microleakage of glass ionomer-based provisional cement with resin-based provisional cement and zinc oxide non-eugenol (ZONE) provisional cement in computer-aided design and computer-aided manufacturing (CAD/CAM)-fabricated interim restorations. Fifteen intact human premolars were prepared in a standardized manner for complete coverage of crown restorations. Interim crowns for the prepared teeth were then fabricated using CAD/CAM, and the specimens were randomized into three groups of provisional cementing agents (n = 5 each): Glass ionomer-based provisional cement (GC Fuji TEMP LT™), bisphenol-A-glycidyldimethacrylate (Bis-GMA)/ triethylene glycol dimethacrylate (TEGDMA) resin-based cement (UltraTemp® REZ), and ZONE cement (TempBond NE). After 24 hours of storage in distilled water at 37°C, the specimens were thermocycled and then stored again for 24 hours in distilled water at room temperature. Next, the specimens were placed in freshly prepared 2% aqueous methylene blue dye for 24 hours and then embedded in autopolymerizing acrylic resin blocks and sectioned in buccolingual and mesiodistal directions to assess dye penetration using a stereomicroscope. The results were statistically analyzed using a nonparametric Kruskal-Wallis test. Dunn's post hoc test with a Bonferroni correction test was used to compute multiple pairwise comparisons that identified differences among groups; the level of significance was set at p < 0.05. All groups exhibited marginal microleakage; the Bis-GMA/TEGDMA resin-based provisional cement demonstrated the lowest microleakage scores, which were statistically different from those of the glass ionomer-based provisional cement and the ZONE cement. The provisional cementing agents exhibited different sealing abilities. The Bis-GMA/TEGDMA resin-based provisional cement exhibited the most effective favorable sealing properties against dye penetration compared with the glass ionomer

  16. Ionomer-Liquid Electrolyte Hybrid Ionic Conductor for High Cycling Stability of Lithium Metal Electrodes

    PubMed Central

    Song, Jongchan; Lee, Hongkyung; Choo, Min-Ju; Park, Jung-Ki; Kim, Hee-Tak

    2015-01-01

    The inhomogeneous Li electrodeposition of lithium metal electrode has been a major impediment to the realization of rechargeable lithium metal batteries. Although single ion conducting ionomers can induce more homogeneous Li electrodeposition by preventing Li+ depletion at Li surface, currently available materials do not allow room-temperature operation due to their low room temperature conductivities. In the paper, we report that a highly conductive ionomer/liquid electrolyte hybrid layer tightly laminated on Li metal electrode can realize stable Li electrodeposition at high current densities up to 10 mA cm−2 and permit room-temperature operation of corresponding Li metal batteries with low polarizations. The hybrid layer is fabricated by laminating few micron-thick Nafion layer on Li metal electrode followed by soaking 1 M LiPF6 EC/DEC (1/1) electrolyte. The Li/Li symmetric cell with the hybrid layer stably operates at a high current density of 10 mA cm−2 for more than 2000 h, which corresponds to more than five-fold enhancement compared with bare Li metal electrode. Also, the prototype Li/LiCoO2 battery with the hybrid layer offers cycling stability more than 350 cycles. These results demonstrate that the hybrid strategy successfully combines the advantages of bi-ionic liquid electrolyte (fast Li+ transport) and single ionic ionomer (prevention of Li+ depletion). PMID:26411701

  17. The Bacterial Pathogen Xylella fastidiosa Affects the Leaf Ionome of Plant Hosts during Infection

    PubMed Central

    De La Fuente, Leonardo; Parker, Jennifer K.; Oliver, Jonathan E.; Granger, Shea; Brannen, Phillip M.; van Santen, Edzard; Cobine, Paul A.

    2013-01-01

    Xylella fastidiosa is a plant pathogenic bacterium that lives inside the host xylem vessels, where it forms biofilm believed to be responsible for disrupting the passage of water and nutrients. Here, Nicotiana tabacum was infected with X. fastidiosa, and the spatial and temporal changes in the whole-leaf ionome (i.e. the mineral and trace element composition) were measured as the host plant transitioned from healthy to diseased physiological status. The elemental composition of leaves was used as an indicator of the physiological changes in the host at a specific time and relative position during plant development. Bacterial infection was found to cause significant increases in concentrations of calcium prior to the appearance of symptoms and decreases in concentrations of phosphorous after symptoms appeared. Field-collected leaves from multiple varieties of grape, blueberry, and pecan plants grown in different locations over a four-year period in the Southeastern US showed the same alterations in Ca and P. This descriptive ionomics approach characterizes the existence of a mineral element-based response to X. fastidiosa using a model system suitable for further manipulation to uncover additional details of the role of mineral elements during plant-pathogen interactions. This is the first report on the dynamics of changes in the ionome of the host plant throughout the process of infection by a pathogen. PMID:23667547

  18. Ionomer-Liquid Electrolyte Hybrid Ionic Conductor for High Cycling Stability of Lithium Metal Electrodes

    NASA Astrophysics Data System (ADS)

    Song, Jongchan; Lee, Hongkyung; Choo, Min-Ju; Park, Jung-Ki; Kim, Hee-Tak

    2015-09-01

    The inhomogeneous Li electrodeposition of lithium metal electrode has been a major impediment to the realization of rechargeable lithium metal batteries. Although single ion conducting ionomers can induce more homogeneous Li electrodeposition by preventing Li+ depletion at Li surface, currently available materials do not allow room-temperature operation due to their low room temperature conductivities. In the paper, we report that a highly conductive ionomer/liquid electrolyte hybrid layer tightly laminated on Li metal electrode can realize stable Li electrodeposition at high current densities up to 10 mA cm-2 and permit room-temperature operation of corresponding Li metal batteries with low polarizations. The hybrid layer is fabricated by laminating few micron-thick Nafion layer on Li metal electrode followed by soaking 1 M LiPF6 EC/DEC (1/1) electrolyte. The Li/Li symmetric cell with the hybrid layer stably operates at a high current density of 10 mA cm-2 for more than 2000 h, which corresponds to more than five-fold enhancement compared with bare Li metal electrode. Also, the prototype Li/LiCoO2 battery with the hybrid layer offers cycling stability more than 350 cycles. These results demonstrate that the hybrid strategy successfully combines the advantages of bi-ionic liquid electrolyte (fast Li+ transport) and single ionic ionomer (prevention of Li+ depletion).

  19. Information Management: Army Information Management

    DTIC Science & Technology

    2002-05-31

    user’s Internet needs in one location. Portals commonly provide services such as e -mail, online chat forums, searching, content, newsfeeds and others. Web...The revision dated 31 May 2002-- o Includes new policy on Army knowledge management, Army Knowledge Online, e - mail, Web site management, the use of...Web portals , and Web site. o The revision dated 15 February 2000-- o Replaces the title ’The Army Information Resources Management Program’ with the

  20. How mobile are protons in the structure of dental glass ionomer cements?

    PubMed Central

    Benetti, Ana R.; Jacobsen, Johan; Lehnhoff, Benedict; Momsen, Niels C. R.; Okhrimenko, Denis V.; Telling, Mark T. F.; Kardjilov, Nikolay; Strobl, Markus; Seydel, Tilo; Manke, Ingo; Bordallo, Heloisa N.

    2015-01-01

    The development of dental materials with improved properties and increased longevity can save costs and minimize discomfort for patients. Due to their good biocompatibility, glass ionomer cements are an interesting restorative option. However, these cements have limited mechanical strength to survive in the challenging oral environment. Therefore, a better understanding of the structure and hydration process of these cements can bring the necessary understanding to further developments. Neutrons and X-rays have been used to investigate the highly complex pore structure, as well as to assess the hydrogen mobility within these cements. Our findings suggest that the lower mechanical strength in glass ionomer cements results not only from the presence of pores, but also from the increased hydrogen mobility within the material. The relationship between microstructure, hydrogen mobility and strength brings insights into the material's durability, also demonstrating the need and opening the possibility for further research in these dental cements. PMID:25754555

  1. In vitro Characteristics of a Glass Ionomer Cement

    PubMed Central

    Driscoll, Colin L. W.; Green, J. Douglas; Beatty, Charles W.; McCaffrey, Thomas V.; Marrs, Christopher D.

    1998-01-01

    Glass ionomer cements were first described by Wilson and Kent and have been used in dentistry since 1969. It has been recommended for bridging ossicular chain defects, fixation of ossicular chain prosthesis, anchoring of cochlear implants, mastoid obliteration, and repair of tegmen and posterior canal wall defects. The biocompatability and stability of this material over time is vital to its usefulness in neurotologic surgery. The purpose of this study was to assess the stability of a glass ionomer cement in the presence of bacteria and in different pH environments. We demonstrated that bacteria readily adhere to the surface and their presence is associated with accelerated loss of matrix. We found the cement to be susceptible to low pH and to release a visible cloud of debris upon contact with fluid. Calcium concentration in the solution was elevated at all pH levels. Although we are able to demonstrate these findings in vitro the clinical relevance is unclear. There have been several cases of aseptic meningitis possibly due to intracranial release of components of the cement. Until further studies are done use of the cement in contact with cerebral spinal fluid should be avoided. This cement, or a similar material, would be useful in neurotologic surgery but prior to widespread use further testing should be done to assess safety. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 9Figure 10Figure 11 PMID:17171062

  2. Buonocore Memorial Lecture. Glass-ionomer cements: past, present and future.

    PubMed

    Mount, G J

    1994-01-01

    It was Michael Buonocore who focused the attention of the profession on adhesion in the oral cavity. He expanded the concept of adhesion of resins to enamel and investigated adhesion to dentin. The problem has been solved through the glass-ionomer cements rather than with resins, but sadly, he did not live to see them achieve maturity. The glass-ionomer cements were introduced to the profession in 1976, and they provide adhesion to both enamel and dentin through an ion exchange with the additional benefit of a continuing fluoride release throughout the life of the restoration. Solubility is low, abrasion resistance is high, and biocompatability is excellent. As a water-based material, they have an excellent chance of survival in the hostile environment of the oral cavity. Acceptance of the early versions was slow because of perceived problems with water exchange, a poor color range, and a lack of translucency. Considerable research has been carried out over the last 20 years by members of the profession and the manufacturers; at this point, the glass-ionomer cements make a very valuable contribution to everyday practice. They are now available as both an autocure and a dual-cure cement, and the color range and translucency are excellent. Problems of clinical placement have been overcome, and it is now a simple matter to take advantage of the adhesion and the fluoride release and place a restoration that is esthetic, resistant to microleakage, long lasting, and a deterent to recurrent caries. Their only limitation lies in the fact that they lack the fracture strength to rebuild marginal ridges and incisal corners. In spite of this limitation, they have opened the way for the introduction of a new range of microcavity designs that allow for conservation of remaining tooth structure to an extent never before available. In the near future physical properties will be improved still further, and the use of these cements will expand considerably.

  3. Shoot ionome to predict the synergism and antagonism between nutrients as affected by substrate and physiological status.

    PubMed

    Pii, Youry; Cesco, Stefano; Mimmo, Tanja

    2015-09-01

    The elemental composition of a tissue or organism is defined as ionome. However, the combined effects on the shoot ionome determined by the taxonomic character, the nutrient status and different substrates have not been investigated. This study tests the hypothesis that phylogenetic variation of monocots and dicots grown in iron deficiency can be distinguished by the shoot ionome. We analyzed 18 elements in barley, cucumber and tomato and in two substrates (hydroponic vs soil) with different nutritional regimes. Multivariate analysis evidenced a clear separation between the species. In hydroponic conditions the main drivers separating the species are non essential-nutrients as Ti, Al, Na and Li, which were positively correlated with macro- (P, K) and micronutrients (Fe, Zn, Mo, B). The separation between species is confirmed when plants are grown on soil, but the distribution is determined especially by macronutrients (S, P, K, Ca, Mg) and micronutrients (B). A number of macro (Mg, Ca, S, P, K) and micronutrients (Fe, Mn, Zn, Cu, Mo, B) contribute to plant growth and several other important physiological and metabolic plant activities. The results reported here confirmed that the synergism and antagonism between them and other non-essential elements (Ti, Al, Si, Na) define the plant taxonomic character. The ionome profile might thus be exploited as a tool for the diagnosis of plants physiological/nutritional status but also in defining biofortification strategies to optimize both mineral enrichment of staple food crops and the nutrient input as fertilizers. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  4. Present and future of glass-ionomers and calcium-silicate cements as bioactive materials in dentistry: Biophotonics-based interfacial analyses in health and disease

    PubMed Central

    Watson, Timothy F.; Atmeh, Amre R.; Sajini, Shara; Cook, Richard J.; Festy, Frederic

    2014-01-01

    Objective Since their introduction, calcium silicate cements have primarily found use as endodontic sealers, due to long setting times. While similar in chemistry, recent variations such as constituent proportions, purities and manufacturing processes mandate a critical understanding of service behavior differences of the new coronal restorative material variants. Of particular relevance to minimally invasive philosophies is the potential for ion supply, from initial hydration to mature set in dental cements. They may be capable of supporting repair and remineralization of dentin left after decay and cavity preparation, following the concepts of ion exchange from glass ionomers. Methods This paper reviews the underlying chemistry and interactions of glass ionomer and calcium silicate cements, with dental tissues, concentrating on dentin–restoration interface reactions. We additionally demonstrate a new optical technique, based around high resolution deep tissue, two-photon fluorescence and lifetime imaging, which allows monitoring of undisturbed cement–dentin interface samples behavior over time. Results The local bioactivity of the calcium-silicate based materials has been shown to produce mineralization within the subjacent dentin substrate, extending deep within the tissues. This suggests that the local ion-rich alkaline environment may be more favorable to mineral repair and re-construction, compared with the acidic environs of comparable glass ionomer based materials. Significance The advantages of this potential re-mineralization phenomenon for minimally invasive management of carious dentin are self-evident. There is a clear need to improve the bioactivity of restorative dental materials and these calcium silicate cement systems offer exciting possibilities in realizing this goal. PMID:24113131

  5. Present and future of glass-ionomers and calcium-silicate cements as bioactive materials in dentistry: biophotonics-based interfacial analyses in health and disease.

    PubMed

    Watson, Timothy F; Atmeh, Amre R; Sajini, Shara; Cook, Richard J; Festy, Frederic

    2014-01-01

    Since their introduction, calcium silicate cements have primarily found use as endodontic sealers, due to long setting times. While similar in chemistry, recent variations such as constituent proportions, purities and manufacturing processes mandate a critical understanding of service behavior differences of the new coronal restorative material variants. Of particular relevance to minimally invasive philosophies is the potential for ion supply, from initial hydration to mature set in dental cements. They may be capable of supporting repair and remineralization of dentin left after decay and cavity preparation, following the concepts of ion exchange from glass ionomers. This paper reviews the underlying chemistry and interactions of glass ionomer and calcium silicate cements, with dental tissues, concentrating on dentin-restoration interface reactions. We additionally demonstrate a new optical technique, based around high resolution deep tissue, two-photon fluorescence and lifetime imaging, which allows monitoring of undisturbed cement-dentin interface samples behavior over time. The local bioactivity of the calcium-silicate based materials has been shown to produce mineralization within the subjacent dentin substrate, extending deep within the tissues. This suggests that the local ion-rich alkaline environment may be more favorable to mineral repair and re-construction, compared with the acidic environs of comparable glass ionomer based materials. The advantages of this potential re-mineralization phenomenon for minimally invasive management of carious dentin are self-evident. There is a clear need to improve the bioactivity of restorative dental materials and these calcium silicate cement systems offer exciting possibilities in realizing this goal. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  6. Fluoride release from glass ionomer restorative materials and the effects of surface coating.

    PubMed

    Hattab, F N; Amin, W M

    2001-06-01

    This in vitro study on fluoride (F) release from conventional and metal-reinforced glass ionomer investigated the following: (1) the release of F in deionized water compared to artificial saliva, (2) the effect of various surface coatings on F release, (3) the uptake of released F by hydroxyapatite, (4) the expression of the release data in a mathematical model, (5) F content in the powders and set materials, and (6) surface morphology of varnished and resin-coated specimens. Glass ionomer Ketac-Fil (KF), Fuji II (FJ), and Ketac-Silver (KS) were mixed according to the manufacturers' instructions, and prepared into specimens of 137.8 mm2 surface area. All three specimens were suspended in 50 ml of deionized water, artificial saliva, or aqueous solution of hydroxyapatite and submitted to constant agitation at 37 degrees C. In a separate experiment, the specimens were coated with varnish or light-cured bonding resin and tested for F release in solutions similar to those for uncoated specimens. The release of F occurred for 28 days. The concentration of F was measured with F-ion-specific electrode. All tested products showed a strong initial rate of F release which decreased with time until it reached a relatively steady rate after two weeks. The F released from KF and FJ was comparable in both pattern and magnitude. They released approximately four times more F than KS. In all cases, the release of F in artificial saliva was significantly (p < 0.001) less than in deionized water. Surface coating the specimens significantly reduced the F release ( p < 0.05 top < 0.001, depending on the product and type of coating). The inhibitory effect of coating markedly decreased with time. Resin coating reduced F release more than varnish in KF and KS, but not for FJ. Essentially, all F released in aqueous solution was taken up by the hydroxyapatite, with FJ ranking the highest in increasing hydroxyapatite F concentration. Over the 28 days, the quantities of F released from FJ, KF

  7. Phenotypic and ionome profiling of Triticum aestivum x Aegilops tauschii introgression lines

    USDA-ARS?s Scientific Manuscript database

    Eighty-four single homozygous introgressions of the Aegilops tauschii D-genome in the ‘Chinese Spring’ genetic background were used to study phenotypic and ionome profiles during two years of field experiments. An augmented design was used with a repeated check of a local bread wheat cultivar was im...

  8. The effect of silver fluoride and potassium iodide on the bond strength of auto cure glass ionomer cement to dentine.

    PubMed

    Knight, G M; McIntyre, J M; Mulyani

    2006-03-01

    Diamine silver fluoride (Ag(NH3)2F), referred to as AgF, has been shown to reduce the incidence of caries in primary dentitions. The clinical application of this material has been limited by staining associated with both teeth and restorative materials. The application of potassium iodide (KI) after AgF eliminates stain formation. There is a lack of information as to how the addition of AgF followed by KI may affect the bond strength to dentine. The purpose of this study was to compare the bond strengths of auto cure glass ionomer cement to dentine surfaces that had been treated with AgF and KI and without treatment. Ten recently extracted human third molars were embedded into methyl methacrylate resin and sliced to form a square block of exposed dentine surfaces. Each of the four surfaces were treated by one of the following procedures: (a) etching with 37 per cent phosphoric acid; (b) applying GC dentine conditioner; (c) etching, followed by application of AgF/KI then washing off the precipitate and air drying; and (d) etching, applying AgF/KI and air drying the reaction products on the surface. Fuji VII auto cure glass ionomer cement was bonded onto each sample and fracture tested. The dentine samples treated with AgF/KI followed by washing away the precipitate and air drying had bond strengths (2.83 MPa) not significantly different from samples that had been conditioned (2.40 MPa). Samples where the AgF/KI precipitate had been air dried onto the dentine surface had significantly lower bond strengths (1.49 MPa) than the washed samples. Samples that were etched had significantly lower bond strengths (1.91MPa) than the conditioned samples. This study found that the application of AgF/KI to etched dentine samples followed by washing off the precipitate, created bond strengths that were not significantly different to conditioned samples. Leaving the AgF/KI precipitate on the dentine surface significantly reduced the bond strength of auto cured glass ionomer cement

  9. Confocal microscopic observation of structural changes in glass-ionomer cements and tooth interfaces.

    PubMed

    Watson, T F; Pagliari, D; Sidhu, S K; Naasan, M A

    1998-03-01

    This study aimed to develop techniques to allow dynamic imaging of a cavity before, during and after placement of glass-ionomer restorative materials. Cavities were cut in recently extracted third molars and the teeth longitudinally sectioned. Each hemisected tooth surface was placed in green modelling compound at 90 to the optical axis of the microscope. The cavity surface was imaged using a video rate confocal microscope in conjunction with an internally focusable microscope objective. The sample on the stage was pushed up to the objective lens which 'clamped' the cover glass onto it. Water, glycerine or oil was placed below the coverglass, with oil above. Internal tooth structures were imaged by changing the internal focus of the objective. The restorative material was then placed into the cavity. Video images were stored either onto video tape or digitally, using a frame grabber, computer and mass memory storage. Software controls produced time-lapse recordings of the interface over time. Preliminary experiments have examined the placement and early maturation of conventional glass-ionomer cements and a syringeable resin-modified glass-ionomer cement. Initial contact of the cement matrix and glass particles was visible as the plastic material rolled past the enamel and dentine, before making a bond. Evidence for water movement from the dentine into the cement has also been seen. After curing, the early dimensional changes in the cements due to water flux were apparent using the time-lapse facility. This new technique enables examination of developing tooth/restoration interfaces and the tracking of movement in materials.

  10. Direct comparisons of X-ray scattering and atomistic molecular dynamics simulations for precise acid copolymers and ionomers

    DOE PAGES

    Buitrago, C. Francisco; Bolintineanu, Dan; Seitz, Michelle E.; ...

    2015-02-09

    Designing acid- and ion-containing polymers for optimal proton, ion, or water transport would benefit profoundly from predictive models or theories that relate polymer structures with ionomer morphologies. Recently, atomistic molecular dynamics (MD) simulations were performed to study the morphologies of precise poly(ethylene-co-acrylic acid) copolymer and ionomer melts. Here, we present the first direct comparisons between scattering profiles, I(q), calculated from these atomistic MD simulations and experimental X-ray data for 11 materials. This set of precise polymers has spacers of exactly 9, 15, or 21 carbons between acid groups and has been partially neutralized with Li, Na, Cs, or Zn. Inmore » these polymers, the simulations at 120 °C reveal ionic aggregates with a range of morphologies, from compact, isolated aggregates (type 1) to branched, stringy aggregates (type 2) to branched, stringy aggregates that percolate through the simulation box (type 3). Excellent agreement is found between the simulated and experimental scattering peak positions across all polymer types and aggregate morphologies. The shape of the amorphous halo in the simulated I(q) profile is in excellent agreement with experimental I(q). We found that the modified hard-sphere scattering model fits both the simulation and experimental I(q) data for type 1 aggregate morphologies, and the aggregate sizes and separations are in agreement. Given the stringy structure in types 2 and 3, we develop a scattering model based on cylindrical aggregates. Both the spherical and cylindrical scattering models fit I(q) data from the polymers with type 2 and 3 aggregates equally well, and the extracted aggregate radii and inter- and intra-aggregate spacings are in agreement between simulation and experiment. Furthermore, these dimensions are consistent with real-space analyses of the atomistic MD simulations. By combining simulations and experiments, the ionomer scattering peak can be associated with the

  11. Synthesis of a proline-modified acrylic acid copolymer in supercritical CO2 for glass-ionomer dental cement applications.

    PubMed

    Moshaverinia, Alireza; Roohpour, Nima; Darr, Jawwad A; Rehman, Ihtesham U

    2009-06-01

    Supercritical (sc-) fluids (such as sc-CO(2)) represent interesting media for the synthesis of polymers in dental and biomedical applications. Sc-CO(2) has several advantages for polymerization reactions in comparison to conventional organic solvents. It has several advantages in comparison to conventional polymerization solvents, such as enhanced kinetics, being less harmful to the environment and simplified solvent removal process. In our previous work, we synthesized poly(acrylic acid-co-itaconic acid-co-N-vinylpyrrolidone) (PAA-IA-NVP) terpolymers in a supercritical CO(2)/methanol mixture for applications in glass-ionomer dental cements. In this study, proline-containing acrylic acid copolymers were synthesized, in a supercritical CO(2) mixture or in water. Subsequently, the synthesized polymers were used in commercially available glass-ionomer cement formulations (Fuji IX commercial GIC). Mechanical strength (compressive strength (CS), diametral tensile strength (DTS) and biaxial flexural strength (BFS)) and handling properties (working and setting time) of the resulting modified cements were evaluated. It was found that the polymerization reaction in an sc-CO(2)/methanol mixture was significantly faster than the corresponding polymerization reaction in water and the purification procedures were simpler for the former. Furthermore, glass-ionomer cement samples made from the terpolymer prepared in sc-CO(2)/methanol exhibited higher CS and DTS and comparable BFS compared to the same polymer synthesized in water. The working properties of glass-ionomer formulations made in sc-CO(2)/methanol were comparable and better than the values of those for polymers synthesized in water.

  12. Synthesis of N-vinylpyrrolidone modified acrylic acid copolymer in supercritical fluids and its application in dental glass-ionomer cements.

    PubMed

    Moshaverinia, Alireza; Roohpour, Nima; Billington, Richard W; Darr, Jawwad A; Rehman, Ihtesham U

    2008-07-01

    Compressed fluids such as supercritical CO(2) offer marvellous opportunities for the synthesis of polymers, particularly in applications in medicine and dentistry. It has several advantages in comparison to conventional polymerisation solvents, such as enhanced kinetics and simplified solvent removal process. In this study, poly(acrylic acid-co-itaconic acid-co-N-vinylpyrrolidone) (PAA-IA-NVP), a modified glass-ionomer polymer, was synthesised in supercritical CO(2) (sc-CO(2)) and methanol as a co-solvent. The synthesised polymer was characterized by (1)H-NMR, Raman and FT-IR spectroscopy and viscometry. The molecular weight of the final product was also measured using static light scattering method. The synthesised polymers were subsequently used in several glass ionomer cement formulations (Fuji II commercial GIC) in which mechanical strength (compressive strength (CS), diametral tensile strength (DTS) and biaxial flexural strength (BFS)) and handling properties (working and setting time) of the resulting cements were evaluated. The polymerisation reaction in sc-CO(2)/methanol was significantly faster than the corresponding polymerisation reaction in water and the purification procedures were simpler for the former. Furthermore, glass ionomer cement samples made from the terpolymer prepared in sc-CO(2)/methanol exhibited higher CS and DTS and comparable BFS compared to the same polymer synthesised in water. The working properties of glass ionomer formulations made in sc-CO(2)/methanol were comparable and in selected cases better than the values of those made from polymers synthesised in water.

  13. Comparative metabolomic and ionomic approach for abundant fishes in estuarine environments of Japan

    PubMed Central

    Yoshida, Seiji; Date, Yasuhiro; Akama, Makiko; Kikuchi, Jun

    2014-01-01

    Environmental metabolomics or ionomics is widely used to characterize the effects of environmental stressors on the health of aquatic organisms. However, most studies have focused on liver and muscle tissues of fish, and little is known about how the other organs are affected by environmental perturbations and effects such as metal pollutants or eutrophication. We examined the metabolic and mineral profiles of three kinds of abundant fishes in estuarine ecosystem, yellowfin goby, urohaze-goby, and juvenile Japanese seabass sampled from Tsurumi River estuary, Japan. Multivariate analyses, including nuclear magnetic resonance-based metabolomics and inductively coupled plasma optical emission spectrometry-based ionomics approaches, revealed that the profiles were clustered according to differences among body tissues rather than differences in body size, sex, and species. The metabolic and mineral profiles of the muscle and fin tissues, respectively, suggest that these tissues are most appropriate for evaluating environmental perturbations. Such analyses will be highly useful in evaluating the environmental variation and diversity in aquatic ecosystems. PMID:25387575

  14. Clustering Effects on Dynamics in Ionomer Solutions: A Neutron Spin Echo Insight

    NASA Astrophysics Data System (ADS)

    Perahia, Dvora; Wijesinghe, Sidath; Senanayake, Manjula; Wickramasinghe, Anuradhi; Mohottalalage, Supun S.; Ohl, Michael

    Ionizable blocks in ionomers associate into aggregates serving as physical cross-links and concurrently form transport pathways. The dynamics of ionomers underline their functionality. Incorporating small numbers of ionic groups into polymers significantly constraint their dynamics. Recent computational studies demonstrated a direct correlation between ionic cluster morphology and polymer dynamics. Here using neutron spin echo, we probe the segmental dynamics of polystyrene sulfonate (PSS) as the degree of sulfonation of the PSS and the solution dielectrics are varied. Specifically, 20Wt% PSS of 11,000 g/mol with polydispersity of 1.02 with 3% and 9% sulfonation were studies in toluene (dielectric constant ɛ = 2.8), a good solvent for polystyrene, and with 5Wt% of ethanol (ɛ = 24.3l) added. The dynamic structure factor S(q,t) was analyzed with a single exponential except for a limited q range where two time constants associated with constraint and mobile segments were detected. S(q,t) exhibits several distinctive time and length scales for the dynamics with a crossover appearing at the length scale of the ionic clusters. NSF DMR 1611136.

  15. Property Control of (Perfluorinated Ionomer)/(Inorganic Oxide) Composites by Tailoring the Nanoscale Morphology

    DTIC Science & Technology

    1994-06-10

    RPeport PROPERTY CONTROL OF ( PERFLUORINATED IONOMER)/(INORGANIC OXIDE) COMPOSITES BY TAILORING THE NANOSCALE MORPHOLOGY Kenneth A. Mauritz and Robert...Concept ......................................... 45 B. [Si0 2 -TiO2 (mixed)]/Nafion Nanocomposites: Sorption of Pre-Mixed Alkoxides...Nanocomposites: Sorption of Pre- Mixed Alkoxides ......................................... 49 A. Experimental Procedure ............................. 49 B

  16. One year comparative clinical evaluation of EQUIA with resin-modified glass ionomer and a nanohybrid composite in noncarious cervical lesions

    PubMed Central

    Vaid, Deepa Sunil; Shah, Nimisha Chinmay; Bilgi, Priyanka Shripad

    2015-01-01

    Aims: Comparative evaluation of EQUIA with a resin-modified glass ionomer cement (RMGIC; GC Gold Label glass ionomer light cured universal restorative cement) and a nanohybrid composite (Tetric N-Ceram) in noncarious cervical lesions (NCCLs). Background: To establish the most suitable material for the restoration of NCCLs. Settings and Design: In vivo study. Materials and Methods: Eighty-seven NCCLs were randomly restored with EQUIA, a RMGIC, and a nanohybrid composite. Clinical evaluation of the restorations was done following the Unites States Public Health criteria by a single-blinded investigator. Data were formulated, and statistical analysis was done by Chi-square test. Statistical Analysis Used: Chi-square test. Results: No significant difference was found between EQUIA, RMGIC, and nanohybrid composite at 1-month, at 6 months, and at 1-year (P > 0.05). Conclusions: EQUIA, resin-modified glass ionomer, and nanohybrid composite performed equally at 1-month, 6 months, and 1-year follow-up periods. PMID:26752837

  17. Homogeneous coating of ionomer on electrocatalyst assisted by polybenzimidazole as an adhesive layer and its effect on fuel cell performance

    NASA Astrophysics Data System (ADS)

    Yang, Zehui; Fujigaya, Tsuyohiko; Nakashima, Naotoshi

    2015-12-01

    The fabrication of homogeneous ionomer distribution in fuel cell catalyst layers is necessary and important to improve the platinum utilization as well as the power density. Here, we focus on the effect of poly[2,2‧-(2,6-pyridine)-5,5‧-bibenzimidazole] (PyPBI) wrapped on multi-walled carbon nanotubes (MWNTs) for anchoring Nafion ionomer to the electrocatalyst, in which PyPBI functions as the binding sites for platinum nanoparticles (Pt-NPs) used as a catalyst. Based on the result using a control composite without having PyPBI, a strong interaction of the Nafion onto the PyPBI layer is recognized. Importantly, we find that the membrane-electrode assembly (MEA) shows a much higher maximum power density than that of the MEA without PyPBI. A homogeneous coating of Nafion on the electrocatalyst using the PyPBI forms a long-range network of the ionomer, leading to an improved Pt-NP utilization efficiency as well as an enhanced power density of the MEA.

  18. Effect of calcium chloride solution immersion on surface hardness of restorative glass ionomer cements.

    PubMed

    Shiozawa, Maho; Takahashi, Hidekazu; Iwasaki, Naohiko; Uo, Motohiro

    2013-01-01

    The objective of this study was to evaluate the effect of the concentration of calcium chloride (CaCl2) solution on the surface hardness of restorative glass ionomer cements (GICs). Two high-viscosity GICs, Fuji IX GP and GlasIonomer FX-II, were immersed in several concentrations of CaCl2 solution for 1 day and 1 week. The immersed specimen surfaces were evaluated using microhardness testing, grazing incidence X-ray diffraction, and energy-dispersive X-ray spectroscopy. Immersion in a higher concentration of CaCl2 solution produced a greater increase in the surface hardness. No crystalline substance was observed on the immersed surface. Calcium ions were selectively absorbed in the matrix of the GIC surface after immersion. They reacted with the non-reacted carboxylic acid groups remaining in the cement matrix. These reactions were considered to cause an increase in the surface hardness of the GICs.

  19. Water-induced nanochannel networks in self-assembled block ionomers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mineart, Kenneth P.; Al-Mohsin, Heba A.; Lee, Byeongdu

    2016-03-07

    Block ionomers cast from solution exhibit solvent-templated morphologies that can be altered by solvent-vapor annealing. When cast from a mixed solvent, a midblock-sulfonated pentablock ion- omer self-assembles into spherical ionic microdomains that are loosely connected. Upon exposure to liquid water, nanoscale channels irreversibly develop between the microdomains due to swelling and form a continuous mesoscale network. We use electron tomography and real-time X-ray scat- tering to follow this transformation and show that the resultant morphology provides a highly effec- tive diffusive pathway.

  20. Information Requirements for a Procurement Management Information System.

    DTIC Science & Technology

    1975-08-01

    Management Information System is...described and some justification for this type of procurement management information system is presented. A literature search was made to determine...information systems. If information requirements are correctly identified and satisfied by a procurement management information system , contract administration and procurement management can be

  1. Mapping of Ionomic Traits in Mimulus guttatus Reveals Mo and Cd QTLs That Colocalize with MOT1 Homologues

    PubMed Central

    Lowry, David B.; Sheng, Calvin C.; Zhu, Zhirui; Juenger, Thomas E.; Lahner, Brett; Salt, David E.; Willis, John H.

    2012-01-01

    Natural variation in the regulation of the accumulation of mineral nutrients and trace elements in plant tissues is crucial to plant metabolism, development, and survival across different habitats. Studies of the genetic basis of natural variation in nutrient metabolism have been facilitated by the development of ionomics. Ionomics is a functional genomic approach for the identification of the genes and gene networks that regulate the elemental composition, or ionome, of an organism. In this study, we evaluated the genetic basis of divergence in elemental composition between an inland annual and a coastal perennial accession of Mimulus guttatus using a recombinant inbred line (RIL) mapping population. Out of 20 elements evaluated, Mo and Cd were the most divergent in accumulation between the two accessions and were highly genetically correlated in the RILs across two replicated experiments. We discovered two major quantitative trait loci (QTL) for Mo accumulation, the largest of which consistently colocalized with a QTL for Cd accumulation. Interestingly, both Mo QTLs also colocalized with the two M. guttatus homologues of MOT1, the only known plant transporter to be involved in natural variation in molybdate uptake. PMID:22292026

  2. Synthesis of Ag doped calcium phosphate particles and their antibacterial effect as additives in dental glass ionomer cements.

    PubMed

    Chen, Song; Gururaj, Satwik; Xia, Wei; Engqvist, Håkan

    2016-11-01

    Developing dental restorations with enhanced antibacterial properties has been a constant quest for materials scientists. The aim of this study was to synthesize silver doped calcium phosphate particles and use them to improve antibacterial properties of conventional glass ionomer cement. The Ag doped monetite (Ag-DCPA) and hydroxyapatite (Ag-HA) were synthesized by precipitation method and characterized using X-ray diffraction, scanning electron microscope and X-ray fluorescence spectroscopy. The antibacterial properties of the cements aged for 1 day and 7 days were evaluated by direct contact measurement using staphylococcus epidermis Xen 43. Ion concentrations (F - and Ag + ) and pH were measured to correlate to the results of the antibacterial study. The compressive strength of the cements was evaluated with a crosshead speed of 1 mm/min. The glass ionomer cements containing silver doped hydroxyapatite or monetite showed improved antibacterial properties. Addition of silver doped hydroxyapatite or monetite did not change the pH and ion release of F - . Concentration of Ag + was under the detection limit (0.001 mg/L) for all samples. Silver doped hydroxyapatite or monetite had no effect on the compressive strength of glass ionomer cement.

  3. Changes in compressive strength on ageing in glass polyalkenoate (glass-ionomer) cements prepared from acrylic/maleic acid copolymers.

    PubMed

    Nicholson, J W; Abiden, F

    1997-01-01

    Previous studies have shown that glass-ionomers made from acrylic/maleic copolymers stored in water reach a maximum strength at about 1 week, and after 4 months have become significantly weaker. This finding, which contrasts with the behaviour of glass-ionomers based on poly(acrylic acid), was originally attributed to hydrolytic instability. This interpretation has been tested in the current work. Specimens of glass-ionomer prepared from acrylic/maleic acid copolymer have been stored for up to 4 months in different media, namely deionized water, dry air and vegetable oil, then tested for compressive strength. Specimens were in the form of cylinders of dimensions 6 mm high x 4 mm diameter, and storage temperature was 37 degrees C. Data were analysed using two-way analysis of variance (ANOVA) and in all three media specimens became weaker at 4 months than they had been at 1 week (P < 0.05). However, for the specimens stored in dry air and in water, the 1-week values were not the maximum. The fact that there was a loss of strength under all conditions led to the conclusion that it is not, after all, due to hydrolysis.

  4. In Silico Ionomics Segregates Parasitic from Free-Living Eukaryotes

    PubMed Central

    Greganova, Eva; Steinmann, Michael; Mäser, Pascal; Fankhauser, Niklaus

    2013-01-01

    Ion transporters are fundamental to life. Due to their ancient origin and conservation in sequence, ion transporters are also particularly well suited for comparative genomics of distantly related species. Here, we perform genome-wide ion transporter profiling as a basis for comparative genomics of eukaryotes. From a given predicted proteome, we identify all bona fide ion channels, ion porters, and ion pumps. Concentrating on unicellular eukaryotes (n = 37), we demonstrate that clustering of species according to their repertoire of ion transporters segregates obligate endoparasites (n = 23) on the one hand, from free-living species and facultative parasites (n = 14) on the other hand. This surprising finding indicates strong convergent evolution of the parasites regarding the acquisition and homeostasis of inorganic ions. Random forest classification identifies transporters of ammonia, plus transporters of iron and other transition metals, as the most informative for distinguishing the obligate parasites. Thus, in silico ionomics further underscores the importance of iron in infection biology and suggests access to host sources of nitrogen and transition metals to be selective forces in the evolution of parasitism. This finding is in agreement with the phenomenon of iron withholding as a primordial antimicrobial strategy of infected mammals. PMID:24048281

  5. In silico ionomics segregates parasitic from free-living eukaryotes.

    PubMed

    Greganova, Eva; Steinmann, Michael; Mäser, Pascal; Fankhauser, Niklaus

    2013-01-01

    Ion transporters are fundamental to life. Due to their ancient origin and conservation in sequence, ion transporters are also particularly well suited for comparative genomics of distantly related species. Here, we perform genome-wide ion transporter profiling as a basis for comparative genomics of eukaryotes. From a given predicted proteome, we identify all bona fide ion channels, ion porters, and ion pumps. Concentrating on unicellular eukaryotes (n = 37), we demonstrate that clustering of species according to their repertoire of ion transporters segregates obligate endoparasites (n = 23) on the one hand, from free-living species and facultative parasites (n = 14) on the other hand. This surprising finding indicates strong convergent evolution of the parasites regarding the acquisition and homeostasis of inorganic ions. Random forest classification identifies transporters of ammonia, plus transporters of iron and other transition metals, as the most informative for distinguishing the obligate parasites. Thus, in silico ionomics further underscores the importance of iron in infection biology and suggests access to host sources of nitrogen and transition metals to be selective forces in the evolution of parasitism. This finding is in agreement with the phenomenon of iron withholding as a primordial antimicrobial strategy of infected mammals.

  6. Determination of O₂ Mass Transport at the Pt | PFSA Ionomer Interface under Reduced Relative Humidity.

    PubMed

    Novitski, David; Holdcroft, Steven

    2015-12-16

    Oxygen mass transport resistance through the ionomer component in the cathode catalyst layer is considered to contribute overpotential losses in polymer electrolyte membrane fuel cells. Whereas it is known that water uptake, water transport, and proton conductivity are reduced upon reducing relative humidity, the effect on oxygen mass transport remains unknown. We report a two-electrode approach to determine mass transport coefficients for the oxygen reduction reaction in air at the Pt/perfluorosulfonic acid ionomer membrane interface between 90 and 30% RH at 70 °C using a Pt microdisk in a solid state electrochemical cell. Potential-step chronoamperometry was performed at specific mass-transport limiting potentials to allow for the elucidation of the oxygen diffusion coefficient (D(bO2)) and oxygen concentration (c(bO2)). In our efforts, novel approaches in data acquisition, as well as analysis, were examined because of the dynamic nature of the membrane under lowered hydration conditions. Linear regression analysis reveals a decrease in oxygen permeability (D(bO2c(bO2)) by a factor of 1.7 and 3.4 from 90 to 30% RH for Nafion 211 membrane and membranes cast from Nafion DE2020 ionomer solutions, respectively. Additionally, nonlinear curve fitting by way of the Shoup-Szabo equation is employed to analyze the entire current transient during potential step controlled ORR. We also report on the presence of an RH dependence of our previously reported time-dependency measurements for O2 mass transport coefficients.

  7. Total Quality Management in Information Services. Information Services Management Series.

    ERIC Educational Resources Information Center

    St. Clair, Guy

    Information services managers have a responsibility to provide the best information delivery possible. The basic principles of total quality management can be used by information professionals to help justify library funding through the creation of an environment where customer-patron satisfaction is paramount. This book reveals how to apply the…

  8. INFLUENCE OF HEMA CONTENT ON THE MECHANICAL AND BONDING PROPERTIES OF EXPERIMENTAL HEMA-ADDED GLASS IONOMER CEMENTS

    PubMed Central

    Lim, Ho-Nam; Kim, Seong-Hwan; Yu, Bin; Lee, Yong-Keun

    2009-01-01

    The purpose of this study was to determine the influence of incrementally added uncured HEMA in experimental HEMA-added glass ionomer cement (HAGICs) on the mechanical and shear bond strength (SBS) of these materials. Increasing contents of uncured HEMA (10-50 wt.%) were added to a commercial glass ionomer cement liquid (Fuji II, GC, Japan), and the compressive and diametral tensile strengths of the resulting HAGICs were measured. The SBS to non-precious alloy, precious alloy, enamel and dentin was also determined after these surfaces were subjected to either airborne-particle abrasion (Aa) or SiC abrasive paper grinding (Sp). Both strength properties of the HAGICs first increased and then decreased as the HEMA content increased, with a maximum value obtained when the HEMA content was 20% for the compressive strength and 40% for the tensile strength. The SBS was influenced by the HEMA content, the surface treatment, and the type of bonding surface (p<0.05). These results suggest that addition of an appropriate amount of HEMA to glass ionomer cement would increase diametral tensile strength as well as bond strength to alloys and teeth. These results also confirm that the optimal HEMA content ranged from 20 to 40% within the limitations of this experimental condition. PMID:19668995

  9. Bond Strength of Silorane- and Methacrylate-Based Composites to Resin-Modified Glass Ionomers

    DTIC Science & Technology

    2012-01-13

    genre was given the name of resin-modified glass ionomers (RMGI) (Antonucci et al., 1988). The addition of resin improved many of the drawbacks of...entire surface for 15 seconds then gentle air was used to create an even film over the sample. This layer was cured for 10 seconds using the Bluephase

  10. Effects of N-vinylpyrrolidone (NVP) containing polyelectrolytes on surface properties of conventional glass-ionomer cements (GIC).

    PubMed

    Moshaverinia, Alireza; Roohpour, Nima; Ansari, Sahar; Moshaverinia, Maryam; Schricker, Scott; Darr, Jawwad A; Rehman, Ihtesham U

    2009-10-01

    It has been found that polyacids containing an N-vinylpyrrolidinone (NVP) comonomer produces a glass inomer cement with improved mechanical and handling properties. The objective of this study was to investigate the effect of NVP modified polyelectrolytes on the surface properties and shear bond strength to dentin of glass ionomer cements. Poly(acrylic acid (AA)-co-itaconic acid (IA)-co-N-vinylpyrrolidone) was synthesized by free radical polymerization. The terpolymer was characterized using (1)H NMR, FTIR spectroscopy and viscometry for solution properties. The synthesized polymers were used in glass ionomer cement formulations (Fuji II commercial GIC). Surface properties (wettability) of modified cements were studied by water contact angle measurements as a function of time. Work of adhesion values of different surfaces was also determined. The effect of NVP modified polyacid, on bond strength of glass-ionomer cement to dentin was also investigated. The mean data obtained from contact angle and bonding strength measurements were subjected to one- and two-way analysis of variance (ANOVA) at alpha=0.05. Results showed that NVP modified glass ionomer cements showed significantly lower contact angles (theta=47 degrees) and higher work of adhesion (WA=59.4 erg/cm(2)) in comparison to commercially available Fuji II GIC (theta=60 degrees and WA=50.3 erg/cm(2), respectively). The wettability of dentin surfaces conditioned with NVP containing terpolymer was higher (theta=21 degrees, WA=74.2 erg/cm(2)) than dentin conditioned with Fuji conditioner (theta=30 degrees, WA=69 erg/cm(2)). The experimental cement also showed higher but not statistically significant values for shear bond strength to dentin (7.8 MPa), when compared to control group (7.3 MPa). It was concluded that NVP containing polyelectrolytes are better dentin conditioners than the commercially available dentin conditioner (Fuji Cavity Conditioner, GC). NVP containing terpolymers can enhance the surface

  11. Exploring the Parameters Controlling the Crystallinity-Conductivity Correlation of PFSA Ionomers

    NASA Astrophysics Data System (ADS)

    Kusoglu, Ahmet; Shi, Shouwen; Weber, Adam

    Perfluorosulfonic-acid (PFSA) ionomers are the most commonly used solid-electrolyte in electrochemical energy devices because of their remarkable conductivity and chemical/mechanical stability, with the latter imparted by their semi-crystalline fluorocarbon backbone. PFSAs owe this unique combination of transport/stability functionalities to their phase-separated morphology of conductive hydrophilic ionic domains and the non-conductive hydrophobic backbone, which are connected via pendant chains. Thus, phase-separation is governed by fractions of backbone and ionic groups, which is controlled by the equivalent weight (EW). Therefore, EW, along with the pendant chain chemistry, directly impact the conductive vs non-conductive regions, and consequently the interrelation between transport and stability. Driven by the need to achieve higher conductivities without disrupting the crystallinity, various pendant-chain chemistries have been developed. In this talk, we will report the results of a systematic investigation on hydration, conductivity, mechanical properties and crystallinity of various types and EWs of PFSA ionomers to (i) develop a structure/property map, and (ii) identify the key parameters controlling morphology and properties. It will be discussed how the pendant-chain and backbone lengths affect the conductivity and crystallinity, respectively. Lastly, the data set will be analyzed to explore universal structure/property relationships for PFSAs.

  12. Mechanical and bond strength properties of light-cured and chemically cured glass ionomer cements.

    PubMed

    McCarthy, M F; Hondrum, S O

    1994-02-01

    The purpose of this study was to evaluate the mechanical and bond strength properties of a commercially available light-cured glass ionomer cement and of a chemically cured glass ionomer cement. Sixty recently extracted human molars were randomly divided into six equal groups, and the bond strengths of the two cement types were evaluated at 1 hour, 24 hours, and 7 days. Stainless steel lingual buttons were bonded to prepared enamel surfaces, and the samples were placed in a water bath at 37 degrees C until testing. The shear bond strength of each sample was determined with a universal testing instrument. The mechanical strength properties of the two cements were then evaluated. The transverse flexural strength, compressive strength, rigidity, and diametral tensile strength were tested for each cement at 1 hour, 24 hours, and 7 days. The results of the mechanical property strength tests were then compared with the results of the bond strength tests.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Information Resources Management.

    ERIC Educational Resources Information Center

    Bergeron, Pierrette

    1996-01-01

    Information, like other organizational resources, needs to be managed to help organizations improve productivity, competitiveness, and overall performance. Reviews developments (1986-96) in Information Resources Management (IRM). Examines the concept of IRM; IRM from information technology and integrative perspectives; IRM practices; IRM in the…

  14. Management Information Task Group

    DTIC Science & Technology

    2002-12-18

    Defense Business Practice Implementation Board Management Information Task Group Report...Std Z39-18 Defense Business Practice Implementation Board Management Information Task Group... Business Practice Implementation Board Management Information Task Group Report FY02-2 3

  15. Effect of two prophylaxis methods on marginal gap of Cl Vresin-modified glass-ionomer restorations.

    PubMed

    Kimyai, Soodabeh; Pournaghi-Azar, Fatemeh; Daneshpooy, Mehdi; Abed Kahnamoii, Mehdi; Davoodi, Farnaz

    2016-01-01

    Background. This study evaluated the effect of two prophylaxis techniques on the marginal gap of CI V resin-modified glass-ionomer restorations. Methods. Standard Cl V cavities were prepared on the buccal surfaces of 48 sound bovine mandibular incisors in this in vitro study. After restoration of the cavities with GC Fuji II LC resin-modified glass-ionomer, the samples were randomly assigned to 3 groups of 16. In group 1, the prophylactic procedures were carried out with rubber cup and pumice powder and in group 2 with air-powder polishing device (APD). In group 3 (control), the samples did not undergo any prophylactic procedures. Then the marginal gaps were measured. Two-way ANOVA was used to compare marginal gaps at the occlusal and gingival margins between the groups. Post hoc Tukey test was used for two-by-two comparisons. Statistical significance was set at P < 0.05. Results. There were significant differences in the means of marginal gaps in terms of prophylactic techniques (P < 0.001), with significantly larger marginal gaps in the APD group compared to the pumice and rubber cup group, which in turn exhibited significantly larger marginal gaps compared to the control group (P < 0.0005). In addition, the means of marginal gaps were significant in terms of the margin type (P < 0.001), with significantly larger gaps at gingival margins compared to the occlusal margins (P < 0.0005). Conclusion. The prophylactic techniques used in this study had a negative effect on the marginal gaps of Cl V resin-modified glass-ionomer restorations.

  16. Hearing Outcome With the Use of Glass Ionomer Cement as an Alternative to Crimping in Stapedotomy.

    PubMed

    Elzayat, Saad; Younes, Ahmed; Fouad, Ayman; Erfan, Fatthe; Mahrous, Ali

    2017-10-01

    To evaluate early hearing outcomes using glass ionomer cement to fix the Teflon piston prosthesis onto the long process of incus to minimize residual conductive hearing loss after stapedotomy. Original report of prospective randomized control study. Tertiary referral center. A total of 80 consecutive patients with otosclerosis were randomized into two groups. Group A is a control group in which 40 patients underwent small fenestra stapedotomy using the classic technique. Group B included 40 patients who were subjected to small fenestra stapedotomy with fixation of the incus-prosthesis junction with glass ionomer bone cement. Stapedotomy with the classical technique in group A and the alternative technique in group B. The audiometric results before and after surgery. Analysis of the results was performed using the paired t test to compare between pre and postoperative results. χ test was used to compare the results of the two groups. A p value less than 0.05 was considered significant from the statistical standpoint. Significant postoperative improvement of both pure-tone air conduction thresholds and air-bone gaps were reported in the two studied groups. The postoperative average residual air-bone gap and hearing gain were statistically significant in group B (p < 0.05) compared with group A. The use of glass ionomer bone cement in primary otosclerosis surgery using the aforementioned prosthesis and the surgical technique is of significant value in producing maximal closure of the air-bone gap and better audiological outcomes.

  17. Fluorescence changes in remineralized and nonremineralized enamel adjacent to glass ionomer ART restorations: an in vitro study.

    PubMed

    Gaskin, Elizabeth B; Harless, Jeffrey D; Wefel, James S; Guzmán-Armstrong, Sandra; Armstrong, Steven R; Vargas, Marcos A; Hernández, Maria Marcela; Qian, Fang

    2007-01-01

    The purpose of this study was to evaluate fluorescence changes of remineralized and nonremineralized enamel margins adjacent to glass ionomer restorations during a pH cycling sequence. One hundred permanent molar and premolar teeth were placed in a demineralizing solution for 3 days and restored with a glass ionomer restoration (simulating Atraumatic Restorative Treatment [ART]). Half were placed in a remin solution for 7 days to create a remineralization (remin) group. Specimens were randomly divided into 4 groups (N=25): (a) 2 remin groups; and (b) 2 nonremin groups. One half of the remin and nonremin group specimens were treated with a 5,000-ppm sodium fluoride solution during pH cycling with remin fluid and an acidic beverage over 20 days. Fluorescence changes were recorded with quantitative light fluorescence (QLF). Higher fluorescence values indicated less lesion porosity. Statistical comparisons between the groups over the 5 measurement sessions of cycling were performed using repeated measures of analysis of variance with a post-hoc test, paired-sample t test and 2-sample t tests (alpha=0.05). The remin groups experienced significantly less lesion porosity than the nonremin groups. Fluoride groups experienced less lesion porosity than the nonfluoride groups. A brief period of remineralization and use of a prescription strength fluoridated rinse improved the enamel substrate surrounding glass ionomer restorations, resulting in less lesion porosity.

  18. A Twofold Comparison between Dual Cure Resin Modified Cement and Glass Ionomer Cement for Orthodontic Band Cementation.

    PubMed

    Attar, Hanaa El; Elhiny, Omnia; Salem, Ghada; Abdelrahman, Ahmed; Attia, Mazen

    2016-12-15

    To test the solubility of dual cure resin modified resin cement in a food simulating solution and the shear bond strength compared to conventional Glass ionomer cement. The materials tested were self-adhesive dual cure resin modified cement and Glass Ionomer (GIC). Twenty Teflon moulds were divided into two groups of tens. The first group was injected and packed with the modified resin cement, the second group was packed with GIC. To test the solubility, each mould was weighed before and after being placed in an analytical reagent for 30 days. The solubility was measured as the difference between the initial and final drying mass. To measure the Shear bond strength, 20 freshly extracted wisdom teeth were equally divided into two groups and embedded in self-cure acrylic resin. Four mm sections of stainless steel bands were cemented to the exposed buccal surfaces of teeth under a constant load of 500 g. Shear bond strength was measured using a computer controlled materials testing machine and the load required to deband the samples was recorded in Newtons. GIC showed significantly higher mean weight loss and an insignificant lower Shear bond strength, compared to dual cure resin Cement. It was found that dual cure resin modified cement was less soluble than glass ionomer cement and of comparable bond strength rendering it more useful clinically for orthodontic band cementation.

  19. Comparison of antibacterial activity of glass-ionomer cement and amalgam in class two restorations by Streptococcus mutans count analysis at fixed intervals: an in vivo study.

    PubMed

    Tegginmani, Veeresh S; Goel, Beenarani; Uppin, Virendra; Horatti, Priya; Kumar, L S Vijay; Nainani, Abhinav

    2013-05-01

    The purpose of the present study was to determine the influence of glass ionomer cement and amalgam restoration on the level of Streptococcus mutans in the interproximal plaque at periodic intervals and also to compare these values. Seventeen adult patients having two proximal carious lesions on any quadrant of the jaw (either opposing or contralateral) were selected for this study. Carious lesions were diagnosed clinically and from bitewing radiographs. Of the two carious lesions, one was restored with glass ionomer cermet cement and another with amalgam. Plaque samples were collected from interproximal areas before and at 1 month and 3 months post-treatment in a test tube containing 5 ml of modified Stuart's liquid transport fluid. Identification of organisms in the colony was done after Gram staining. Comparison of values before restoration and after restoration at 1 month interval showed a statistically significant decrease (p<0.001). Similarly, comparison of values before and after restorations at 3 months also showed statistically significant decrease (p<0.02). But comparison of restorations of 1 and 3 months intervals showed no statistical significant difference (p>0.05). Glass ionomer restorations have definite advantage over the amalgam, as the tunnel preparation is more conservative and fluoride release from the glass ionomer inhibits the growth of S. mutans in the plaque. Glass ionomer cement should be preferred over amalgam in conservatively prepared restorations as it reduces the microbial activities due to fluoride release.

  20. Universal Payload Information Management

    NASA Technical Reports Server (NTRS)

    Elmore, Ralph B.

    2003-01-01

    As the overall manager and integrator of International Space Station (ISS) science payloads, the Payload Operations Integration Center (POIC) at Marshall Space Flight Center has a critical need to provide an information management system for exchange and control of ISS payload files as well as to coordinate ISS payload related operational changes. The POIC's information management system has a fundamental requirement to provide secure operational access not only to users physically located at the POIC, but also to remote experimenters and International Partners physically located in different parts of the world. The Payload Information Management System (PIMS) is a ground-based electronic document configuration management and collaborative workflow system that was built to service the POIC's information management needs. This paper discusses the application components that comprise the PIMS system, the challenges that influenced its design and architecture, and the selected technologies it employs. This paper will also touch on the advantages of the architecture, details of the user interface, and lessons learned along the way to a successful deployment. With PIMS, a sophisticated software solution has been built that is not only universally accessible for POIC customer s information management needs, but also universally adaptable in implementation and application as a generalized information management system.

  1. Failure Rate of Direct High-Viscosity Glass-Ionomer Versus Hybrid Resin Composite Restorations in Posterior Permanent Teeth - a Systematic Review

    PubMed Central

    Mickenautsch, Steffen; Yengopal, Veerasamy

    2015-01-01

    Purpose Traditionally, resin composite restorations are claimed by reviews of the dental literature as being superior to glass-ionomer fillings in terms of restoration failures in posterior permanent teeth. The aim of this systematic review is to answer the clinical question, whether conventional high-viscosity glass-ionomer restorations, in patients with single and/or multi-surface cavities in posterior permanent teeth, have indeed a higher failure rate than direct hybrid resin composite restorations. Methods Eight databases were searched until December 02, 2013. Trials were assessed for bias risks, in-between datasets heterogeneity and statistical sample size power. Effects sizes were computed and statistically compared. A total of 55 citations were identified through systematic literature search. From these, 46 were excluded. No trials related to high-viscosity glass-ionomers versus resin composite restorations for direct head-to-head comparison were found. Three trials related to high-viscosity glass-ionomers versus amalgam and three trials related to resin composite versus amalgam restorations could be included for adjusted indirect comparison, only. Results The available evidence suggests no difference in the failure rates between both types of restoration beyond the play of chance, is limited by lack of head-to-head comparisons and an insufficient number of trials, as well as by high bias and in-between-dataset heterogeneity risk. The current clinical evidence needs to be regarded as too poor in order to justify superiority claims regarding the failure rates of both restoration types. Sufficiently large-sized, parallel-group, randomised control trials with high internal validity are needed, in order to justify any clinically meaningful judgment to this topic. PMID:26962372

  2. Information Risk Management and Resilience

    NASA Astrophysics Data System (ADS)

    Dynes, Scott

    Are the levels of information risk management efforts within and between firms correlated with the resilience of the firms to information disruptions? This paper examines the question by considering the results of field studies of information risk management practices at organizations and in supply chains. The organizations investigated differ greatly in the degree of coupling from a general and information risk management standpoint, as well as in the levels of internal awareness and activity regarding information risk management. The comparison of the levels of information risk management in the firms and their actual or inferred resilience indicates that a formal information risk management approach is not necessary for resilience in certain sectors.

  3. Ion conduction in high ion content PEO-based ionomers

    NASA Astrophysics Data System (ADS)

    Caldwell, David, II; Maranas, Janna

    Solid Polymer Electrolytes (SPEs) can enable the design of batteries that are safer and have higher capacity than batteries with traditional volatile organic electrolytes. The current limitation for SPEs is their low conductivity, resulting from a conduction mechanism strongly coupled to the dynamics of the polymer host matrix. Our previous work indicated the possibility of a conduction mechanism through the use of ion aggregates. In order to investigate this mechanism, we performed a series of molecular dynamics simulations of PEO-based ionomers at high ion content. Our results indicate that conduction through ion aggregates are partially decoupled from polymer dynamics and could enable the development of higher conductive SPEs.

  4. Mechanocatalytic depolymerization of cellulose with perfluorinated sulfonic acid ionomers

    NASA Astrophysics Data System (ADS)

    Karam, Ayman; Amaniampong, Prince N.; García Fernández, José M.; Oldani, Claudio; Marinkovic, Sinisa; Estrine, Boris; De Oliveira Vigier, Karine; Jérôme, François

    2018-03-01

    Here, we investigated that the mechanocatalytic depolymerization of cellulose in the presence of Aquivion, a sulfonated perfluorinated ionomer. Under optimized conditions, yields of water soluble sugars of 90-97 % were obtained using Aquivion PW98 and PW66, respectively, as a solid acid catalyst. The detailed characterization of the water soluble fraction revealed (i) the selective formation of oligosaccharides with a DP up to 11 and (ii) that depolymerization and reversion reactions concomitantly occurred during the mechanocatalytic process, although the first largely predominated. More importantly, we discussed on the critical role of water contained in Aquivion and cellulose on the efficiency of the mechanocatalytic process.

  5. Mechanocatalytic Depolymerization of Cellulose With Perfluorinated Sulfonic Acid Ionomers

    PubMed Central

    Karam, Ayman; Amaniampong, Prince N.; García Fernández, José M.; Oldani, Claudio; Marinkovic, Sinisa; Estrine, Boris; De Oliveira Vigier, Karine; Jérôme, François

    2018-01-01

    Here, we investigated that the mechanocatalytic depolymerization of cellulose in the presence of Aquivion, a sulfonated perfluorinated ionomer. Under optimized conditions, yields of water soluble sugars of 90–97% were obtained using Aquivion PW98 and PW66, respectively, as a solid acid catalyst. The detailed characterization of the water soluble fraction revealed (i) the selective formation of oligosaccharides with a DP up to 11 and (ii) that depolymerization and reversion reactions concomitantly occurred during the mechanocatalytic process, although the first largely predominated. More importantly, we discussed on the critical role of water contained in Aquivion and cellulose on the efficiency of the mechanocatalytic process. PMID:29623273

  6. Mechanocatalytic Depolymerization of Cellulose With Perfluorinated Sulfonic Acid Ionomers.

    PubMed

    Karam, Ayman; Amaniampong, Prince N; García Fernández, José M; Oldani, Claudio; Marinkovic, Sinisa; Estrine, Boris; De Oliveira Vigier, Karine; Jérôme, François

    2018-01-01

    Here, we investigated that the mechanocatalytic depolymerization of cellulose in the presence of Aquivion, a sulfonated perfluorinated ionomer. Under optimized conditions, yields of water soluble sugars of 90-97% were obtained using Aquivion PW98 and PW66, respectively, as a solid acid catalyst. The detailed characterization of the water soluble fraction revealed (i) the selective formation of oligosaccharides with a DP up to 11 and (ii) that depolymerization and reversion reactions concomitantly occurred during the mechanocatalytic process, although the first largely predominated. More importantly, we discussed on the critical role of water contained in Aquivion and cellulose on the efficiency of the mechanocatalytic process.

  7. Soil ionomic and enzymatic responses and correlations to fertilizations amended with and without organic fertilizer in long-term experiments.

    PubMed

    Feng, Xumeng; Ling, Ning; Chen, Huan; Zhu, Chen; Duan, Yinghua; Peng, Chang; Yu, Guanghui; Ran, Wei; Shen, Qirong; Guo, Shiwei

    2016-04-15

    To investigate potential interactions between the soil ionome and enzyme activities affected by fertilization with or without organic fertilizer, soil samples were collected from four long-term experiments over China. Irrespective of variable interactions, fertilization type was the major factor impacting soil ionomic behavior and accounted for 15.14% of the overall impact. Sampling site was the major factor affecting soil enzymatic profile and accounted for 34.25% of the overall impact. The availabilities of Pb, La, Ni, Co, Fe and Al were significantly higher in soil with only chemical fertilizer than the soil with organic amendment. Most of the soil enzyme activities, including α-glucosidase activity, were significantly activated by organic amendment. Network analysis between the soil ionome and the soil enzyme activities was more complex in the organic-amended soils than in the chemical fertilized soils, whereas the network analysis among the soil ions was less complex with organic amendment. Moreover, α-glucosidase was revealed to generally harbor more corrections with the soil ionic availabilities in network. We concluded that some of the soil enzymes activated by organic input can make the soil more vigorous and stable and that the α-glucosidase revealed by this analysis might help stabilize the soil ion availability.

  8. Soil ionomic and enzymatic responses and correlations to fertilizations amended with and without organic fertilizer in long-term experiments

    PubMed Central

    Feng, Xumeng; Ling, Ning; Chen, Huan; Zhu, Chen; Duan, Yinghua; Peng, Chang; Yu, Guanghui; Ran, Wei; Shen, Qirong; Guo, Shiwei

    2016-01-01

    To investigate potential interactions between the soil ionome and enzyme activities affected by fertilization with or without organic fertilizer, soil samples were collected from four long-term experiments over China. Irrespective of variable interactions, fertilization type was the major factor impacting soil ionomic behavior and accounted for 15.14% of the overall impact. Sampling site was the major factor affecting soil enzymatic profile and accounted for 34.25% of the overall impact. The availabilities of Pb, La, Ni, Co, Fe and Al were significantly higher in soil with only chemical fertilizer than the soil with organic amendment. Most of the soil enzyme activities, including α-glucosidase activity, were significantly activated by organic amendment. Network analysis between the soil ionome and the soil enzyme activities was more complex in the organic-amended soils than in the chemical fertilized soils, whereas the network analysis among the soil ions was less complex with organic amendment. Moreover, α-glucosidase was revealed to generally harbor more corrections with the soil ionic availabilities in network. We concluded that some of the soil enzymes activated by organic input can make the soil more vigorous and stable and that the α-glucosidase revealed by this analysis might help stabilize the soil ion availability. PMID:27079657

  9. Bovine serum albumin release from novel chitosan-fluoro-aluminosilicate glass ionomer cement: stability and cytotoxicity studies.

    PubMed

    Limapornvanich, Araya; Jitpukdeebodintra, Suwanna; Hengtrakool, Chanothai; Kedjarune-Leggat, Ureporn

    2009-09-01

    This study aimed to evaluate the effect of adding chitosan (CS) to conventional glass ionomer cement (GIC) on protein release and its cytotoxicity. Bovine serum albumin (BSA) was used as the released protein from two glass ionomer formulations. One (GIC+BSA) contained fluoro-aluminosilicate glass mixed with BSA, and another (GIC:CS+BSA) used a similar glass and BSA with 20% chitosan. Six disc specimens per group (10mm in diameter, 2mm in height) were prepared and placed in phosphate buffer saline, which was replaced at various times over 2 weeks. The released protein was determined by a BCA assay. Cytotoxicity of the extracts from these materials for 1, 2 and 7 days to dental pulp cells was evaluated using MTT assay. The GIC:CS+BSA released a burst of BSA in the first 6h, and slowly released at different rates over the 2 weeks. GIC+BSA showed a similar result, but protein could not be detected at the 12h. The protein release rate of GIC:CS+BSA was significantly greater than GIC+BSA (P<0.01); nearly three times higher. The released BSA had the same molecular weight as evaluated by SDS-PAGE. From the MTT assay, the percentages of viable cells were significantly different and can be arranged as: GIC:CS+BSA>GIC:CS>GI+BSA>GI and the cytotoxicity was increased by time of extraction. Chitosan added in glass ionomer cement can prolong release of BSA as well as not increasing the toxicity to pulp cells. This material may be useful for protein delivery.

  10. Apical and root canal space sealing abilities of resin and glass ionomer-based root canal obturation systems.

    PubMed

    Royer, Kinga; Liu, Xue Jun; Zhu, Qiang; Malmstrom, Hans; Ren, Yan-Fang

    2013-01-01

    To investigate the apical sealing ability of glass ionomer and resin-based root canal obturation systems in comparison to a conventional vertical compaction of warm guttapercha. Forty-five extracted human teeth were randomly assigned into 3 groups of 15 each: a resin-based (EndoRez), a glass ionomer-based (Activ GP), and a conventional gutta-percha plus pulp sealer obturation system (GP/EWT). Apical and root canal space sealing abilities were assessed on five cross-sections 1.0 mm apart starting from the apex. Cross-section images were analysed using a focus-variation 3D scanning microscope and unsealed space was calculated as the percentage of total root canal space occupied by voids and debris. EndoRez had significantly higher rate of apical leakage and deeper dye penetration as compared to GP/EWT and Activ GP. EndoRez group had also more voids and debris (22.5%) in the root canal spaces as compared to GP/EWT (10.5%) and Activ GP (10.8%). Apical leakages occurred not only along the root canal walls, but also along the gutta-percha cones with EndoRez as a result of significant polymerisation shrinkage of the resin sealer. Resin-based EndoRez did not form an adequate apical seal of filled root canals. Glass ionomer-based Activ GP was comparable to a vertical compaction of warm guttapercha plus EWT sealer in sealing root canal spaces.

  11. Biaxial Flexural Strength of High-Viscosity Glass-Ionomer Cements Heat-Cured with an LED Lamp during Setting

    PubMed Central

    Fabián Molina, Gustavo; Cabral, Ricardo Juan; Mazzola, Ignacio; Brain Lascano, Laura; Frencken, Jo E.

    2013-01-01

    Adding heat to glass ionomers during setting might improve mechanical properties. The aim was to compare the biaxial flexural strength (BFS) between and within four glass ionomers, by time of exposure to a high-intensity LED light-curing unit. Materials and methods. Samples of Fuji 9 Gold Label, Ketac Molar Easymix, ChemFil Rock, and the EQUIA system were divided into three treatment groups (n = 30): without heating (Group 1), heated with LED lamp of 1400 mW/cm2 for 30 s while setting (Group 2), and heated with LED lamp of 1400 mW/cm2 for 60 s while setting (Group 3). Samples were stored for 48 hours in distilled water at 37°C until tested. BFS was tested, using a universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed, using ANOVA test with the Bonferroni correction (α = 0.05). Heating the glass-ionomer cements with an LED curing light of 1400 mW/cm2 during setting for 30 s increased the BFS value of all GICs. No statistically significant difference in mean BFS scores was found between the EQUIA system and ChemFil Rock at 30 s and 60 s. The mean BFS value was statistically significantly higher for the EQUIA system and ChemFil Rock than for Fuji 9 Gold Label and Ketac Molar Easymix at all exposure times. PMID:23841095

  12. A Twofold Comparison between Dual Cure Resin Modified Cement and Glass Ionomer Cement for Orthodontic Band Cementation

    PubMed Central

    Attar, Hanaa El; Elhiny, Omnia; Salem, Ghada; Abdelrahman, Ahmed; Attia, Mazen

    2016-01-01

    AIM: To test the solubility of dual cure resin modified resin cement in a food simulating solution and the shear bond strength compared to conventional Glass ionomer cement. MATERIALS AND METHOD: The materials tested were self-adhesive dual cure resin modified cement and Glass Ionomer (GIC). Twenty Teflon moulds were divided into two groups of tens. The first group was injected and packed with the modified resin cement, the second group was packed with GIC. To test the solubility, each mould was weighed before and after being placed in an analytical reagent for 30 days. The solubility was measured as the difference between the initial and final drying mass. To measure the Shear bond strength, 20 freshly extracted wisdom teeth were equally divided into two groups and embedded in self-cure acrylic resin. Four mm sections of stainless steel bands were cemented to the exposed buccal surfaces of teeth under a constant load of 500 g. Shear bond strength was measured using a computer controlled materials testing machine and the load required to deband the samples was recorded in Newtons. RESULTS: GIC showed significantly higher mean weight loss and an insignificant lower Shear bond strength, compared to dual cure resin Cement. CONCLUSION: It was found that dual cure resin modified cement was less soluble than glass ionomer cement and of comparable bond strength rendering it more useful clinically for orthodontic band cementation. PMID:28028417

  13. Biaxial flexural strength of high-viscosity glass-ionomer cements heat-cured with an LED lamp during setting.

    PubMed

    Fabián Molina, Gustavo; Cabral, Ricardo Juan; Mazzola, Ignacio; Brain Lascano, Laura; Frencken, Jo E

    2013-01-01

    Adding heat to glass ionomers during setting might improve mechanical properties. The aim was to compare the biaxial flexural strength (BFS) between and within four glass ionomers, by time of exposure to a high-intensity LED light-curing unit. Materials and methods. Samples of Fuji 9 Gold Label, Ketac Molar Easymix, ChemFil Rock, and the EQUIA system were divided into three treatment groups (n = 30): without heating (Group 1), heated with LED lamp of 1400 mW/cm(2) for 30 s while setting (Group 2), and heated with LED lamp of 1400 mW/cm(2) for 60 s while setting (Group 3). Samples were stored for 48 hours in distilled water at 37°C until tested. BFS was tested, using a universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed, using ANOVA test with the Bonferroni correction (α = 0.05). Heating the glass-ionomer cements with an LED curing light of 1400 mW/cm(2) during setting for 30 s increased the BFS value of all GICs. No statistically significant difference in mean BFS scores was found between the EQUIA system and ChemFil Rock at 30 s and 60 s. The mean BFS value was statistically significantly higher for the EQUIA system and ChemFil Rock than for Fuji 9 Gold Label and Ketac Molar Easymix at all exposure times.

  14. The effect of Coca-Cola and fruit juices on the surface hardness of glass-ionomers and 'compomers'.

    PubMed

    Aliping-McKenzie, M; Linden, R W A; Nicholson, J W

    2004-11-01

    The interaction of tooth-coloured dental restorative materials (a conventional glass-ionomer, two resin-modified glass-ionomers and two compomers) with acidic beverages has been studied with the aim of investigating how long-term contact affects solution pH and specimen surface hardness. For each material (ChemFil Superior, ChemFlex, Vitremer Core Build-Up/Restorative, Fuji II LC, Dyract AP and F2000) disc-shaped specimens were prepared and stored in sets of six in the following storage media: 0.9% NaCl (control), Coca-Cola, apple juice and orange juice. After time intervals of 1 day, 1 week, 1 month, 3 months, 4 months, 6 months and 1 year, solution pH and Vickers Hardness Number were determined for each individual specimen. Differences were analysed by anova followed by Student-Newman-Keuls post hoc analysis. All materials were found to reduce the pH of the 0.9% NaCl, but to increase the pH of the acidic beverages. The conventional glass-ionomers dissolved completely in apple juice and orange juice, but survived in Coca-Cola, albeit with a significantly reduced hardness after 1 year. The other materials survived in apple juice and orange juice, but showed greater reductions in surface hardness in these beverages than in Coca-Cola. Fruit juices were thus shown to pose a greater erosive threat to tooth coloured materials than Coca-Cola, a finding which is similar to those concerning dentine and enamel towards these drinks.

  15. A comparative study of retentive strengths of zinc phosphate, polycarboxylate and glass ionomer cements with stainless steel crowns--an in vitro study.

    PubMed

    Reddy, R; Basappa, N; Reddy, V V

    1998-03-01

    This study was conducted on 30 extracted human primary molars to assess the retentive strengths of zinc phosphate, polycarboxylate and glass ionomer cements. The teeth were embedded in resin blocks and were randomly divided into 3 groups of 10 each. The occlusal surfaces of all teeth were reduced uniformly by 1.0 to 1.5 mm. All mesial, distal undercuts were removed and sharp angles rounded. This was followed by cementing pretrimmed and precontoured stainless steel crowns on each tooth with hand pressure and storing in artificial saliva at 37 degrees C for 24 hours. Retentive strength was tested using Instron Universal Testing Machine. The load was applied starting from a zero reading and gradually increased until the cemented stainless steel crowns showed signs of movement and then the readings were recorded. It was found that retentive strengths of zinc phosphate and glass ionomer cements were statistically better (P < 0.05) when compared to the polycarboxylate cement. Negligible difference (0. 59 kg/cm2) was however observed between zinc phosphate and glass ionomer cements.

  16. Educating Librarians and Information Resource Managers: Differing Management Perspectives?

    ERIC Educational Resources Information Center

    Bouthillier, France

    1993-01-01

    Examines differences between library management and information resource management (IRM). Highlights include a historical perspective of library management education and IRM; the organizational perspective of library management and the emphasis of information as a resource in IRM; library management and advances in information technology; and…

  17. The Eighth Stage of Information Management: Information Resources Management (IRM) vs. Knowledge Management (KM), and the Chief Information Officer (CIO) vs. the Chief Knowledge Officer (CKO).

    ERIC Educational Resources Information Center

    Chen, Rui

    1998-01-01

    Describes the characteristics of the transfer point of information management to knowledge management (KM), what information resources management (IRM) does, and compares information and knowledge management and the roles of chief information officer (CIO) and chief knowledge officer (CKO). (PEN)

  18. Information Technology Management: DoD Organization Information Assurance Management of Information Technology Goods and Services Acquired Through Interagency Agreements

    DTIC Science & Technology

    2006-02-23

    Information Technology Management Department of Defense Office of Inspector General February 23, 2006 AccountabilityIntegrityQuality DoD...Organization Information Assurance Management of Information Technology Goods and Services Acquired Through Interagency Agreements (D-2006-052) Report...REPORT TYPE 3. DATES COVERED 00-00-2006 to 00-00-2006 4. TITLE AND SUBTITLE Information Technology Management: DoD Organization Information

  19. Management Information Systems Research.

    DTIC Science & Technology

    Research on management information systems is illusive in many respects. Part of the basic research problem in MIS stems from the absence of standard...decision making. But the transition from these results to the realization of ’satisfactory’ management information systems remains difficult indeed. The...paper discusses several aspects of research on management information systems and reviews a selection of efforts that appear significant for future progress. (Author)

  20. A comparative study of retentive strengths of zinc phosphate, polycarboxylate and glass ionomer cements with stainless steel crowns - an in vitro study.

    PubMed

    Raghunath Reddy, M H; Subba Reddy, V V; Basappa, N

    2010-01-01

    An in vitro study was conducted to compare the retentive strengths of zinc phosphate, polycarboxylate and glass ionomer cements using Instron universal testing machine. Thirty preformed and pretrimmed stainless steel crowns were used for cementation on 30 extracted human primary molars which were divided into three groups of 10 teeth in each group. Then the teeth were stored in artificial saliva and incubated at 37°C for 24 h. A load was applied on to the crown and was gradually increased till the crown showed dislodgement, and then the readings were recorded using Instron recorder and analyzed for statistical significance. The surface area of crown was measured by graphical method. The retentive strength was expressed in terms of kg/cm 2 , which was calculated by the equation load divided by area. Retentive strengths of zinc phosphate (ranged from a minimum of 16.93 to amaximum of 28.13 kg/cm 2 with mean of 21.28 kg/cm 2 ) and glass ionomer cement (minimum of 13.69 - 28.15 kg/cm 2 with mean of 20.69 kg/cm 2 ) were greater than that of polycarboxylate cement (minimum of 13.26 - 22.69 kg/cm 2 with mean of 16.79 kg/cm 2 ). Negligible difference (0.59 kg/cm 2 ) of retentive strength was observed between zinc phosphate (21.28 kg/cm 2 ) and glass ionomer cements (20.69 kg/cm 2 ). Glass ionomer cements can be recommended for cementation of stainless steel crowns because of its advantages and the retentive strength was almost similar to that of zinc phosphate cement.

  1. Investigation of the Interaction between Nafion Ionomer and Surface Functionalized Carbon Black Using Both Ultrasmall Angle X-ray Scattering and Cryo-TEM

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yang, Fan; Xin, Le; Uzunoglu, Aytekin

    In making a catalyst ink, the interaction between Nafion ionomer and catalyst support are the key factors that directly affect both ionic conductivity and electronic conductivity of the catalyst layer in a membrane electrode assembly (MEA). One of the major aims of this investigation is to understand the behavior of the catalyst support, Vulcan XC-72 (XC-72) aggregates, in the existence of the Nafion ionomer in a catalyst ink to fill the knowledge gap of the interaction of these components. The dispersion of catalyst ink not only depends on the solvent, but also depends on the interaction of Nafion and carbonmore » particles in the ink. The interaction of Nafion ionomer particles and XC-72 catalyst aggregates in liquid media was studied using ultra small angle x-ray scattering (USAXS) and cryogenic TEM techniques. Carbon black XC-72) and functionalized carbon black systems were introduced to study the interaction behaviors. A multiple curve fitting was used to extract the particle size and size distribution from scattering data. The results suggest that the particle size and size distribution of each system changed significantly in Nafion + XC-72 system, Nafion + NH2-XC72 system, and Nafion + SO3H-XC-72 system, which indicates that an interaction among these components (i.e. ionomer particles and XC-72 aggregates) exists. The cryogenic TEM, which allows for the observation the size of particles in a liquid, was used to validate the scattering results and shows excellent agreement.« less

  2. Effect of acid and laser etching on shear bond strength of conventional and resin-modified glass-ionomer cements to composite resin.

    PubMed

    Navimipour, Elmira Jafari; Oskoee, Siavash Savadi; Oskoee, Parnian Alizadeh; Bahari, Mahmoud; Rikhtegaran, Sahand; Ghojazadeh, Morteza

    2012-03-01

    Success in sandwich technique procedures can be achieved through an acceptable bond between the materials. The aim of this study was to compare the effect of 35% phosphoric acid and Er,Cr:YSGG laser on shear bond strength of conventional glass-ionomer cement (GIC) and resin-modified glass-ionomer cement (RMGIC) to composite resin in sandwich technique. Sixty-six specimens were prepared from each type of glass-ionomer cements and divided into three treatment groups as follows: without pretreatment, acid etching by 35% phosphoric acid for 15 s, and 1-W Er,Cr:YSGG laser treatment for 15 s with a 600-μm-diameter tip aligned perpendicular to the target area at a distance of 1 mm from the surface. Energy density of laser irradiation was 17.7 J/cm(2). Two specimens in each group were prepared for evaluation under a scanning electron microscope (SEM) after surface treatment and the remainder underwent bonding procedure with a bonding agent and composite resin. Then the shear bond strength was measured at a crosshead speed of 0.5 mm/min. Two-factor analysis of variance and post-hoc Tukey test showed that the cement type, surface treatment method, and the interaction of these two factors significantly affect the shear bond strength between glass-ionomer cements and composite resin (p < 0.05). Surface treatment with phosphoric acid or Er,Cr:YSGG laser increased the shear bond strength of GIC to composite resin; however, in RMGIC only laser etching resulted in significantly higher bond strength. These findings were supported by SEM results. The fracture mode was evaluated under a stereomicroscope at ×20.

  3. Information Security Management (ISM)

    NASA Astrophysics Data System (ADS)

    Šalgovičová, Jarmila; Prajová, Vanessa

    2012-12-01

    Currently, all organizations have to tackle the issue of information security. The paper deals with various aspects of Information Security Management (ISM), including procedures, processes, organizational structures, policies and control processes. Introduction of Information Security Management should be a strategic decision. The concept and implementation of Information Security Management in an organization are determined by the corporate needs and objectives, security requirements, the processes deployed as well as the size and structure of the organization. The implementation of ISM should be carried out to the extent consistent with the needs of the organization.

  4. Methodological approaches for using synchrotron X-ray fluorescence (SXRF) imaging as a tool in ionomics: Examples from Arabidopsis thaliana

    PubMed Central

    Hindt, Maria; Socha, Amanda L.; Zuber, Hélène

    2013-01-01

    Here we present approaches for using multi-elemental imaging (specifically synchrotron X-ray fluorescence microscopy, SXRF) in ionomics, with examples using the model plant Arabidopsis thaliana. The complexity of each approach depends on the amount of a priori information available for the gene and/or phenotype being studied. Three approaches are outlined, which apply to experimental situations where a gene of interest has been identified but has an unknown phenotype (Phenotyping), an unidentified gene is associated with a known phenotype (Gene Cloning) and finally, a Screening approach, where both gene and phenotype are unknown. These approaches make use of open-access, online databases with which plant molecular genetics researchers working in the model plant Arabidopsis will be familiar, in particular the Ionomics Hub and online transcriptomic databases such as the Arabidopsis eFP browser. The approaches and examples we describe are based on the assumption that altering the expression of ion transporters can result in changes in elemental distribution. We provide methodological details on using elemental imaging to aid or accelerate gene functional characterization by narrowing down the search for candidate genes to the tissues in which elemental distributions are altered. We use synchrotron X-ray microprobes as a technique of choice, which can now be used to image all parts of an Arabidopsis plant in a hydrated state. We present elemental images of leaves, stem, root, siliques and germinating hypocotyls. PMID:23912758

  5. A comparison of the in vitro cytotoxicity of conventional and resin modified glass ionomer cements

    PubMed Central

    Selimović-Dragaš, Mediha; Huseinbegović, Amina; Kobašlija, Sedin; Hatibović-Kofman, Šahza

    2012-01-01

    To evaluate cytotoxicity of experimental conventional and resin modified glass-ionomer cements on UMR-106 osteoblast cell cultures and cell cultures of NIH3T3 mouse fibroblasts specimens were prepared for every experimental material and divided into: group 1. Conventional glass-ionomer cements: GC Fuji IX GP Fast, GC Fuji Triage and Ketac Silver; group 2. Resin modified glass-ionomer cements: GC Fuji II LC, GC Fuji Plus and Vitrebond; group 3. Positive control was presented by specimens of composite Vit-l-ecence® and negative control-group 4. was presented by α-minimum essential medium for UMR-106 – osteoblast-like cells and Dulbecco’s Modified Eagle’s Medium for NIH3T3 mouse fibroblast cells. Both cell cultures were exposed to 10% of eluate of each single specimen of each experimental material. Experimental dishes were incubated for 24 h. Cell metabolism was evaluated using methyltetrazolium assay. Kruskal-Wallis test and Tukey-Kramer post hoc test for the materials evaluated on NIH3T3 mouse fibroblast cells, as well as UMR-106 osteoblast-like cells showed significantly more cytotoxicity of RMGICs, predominantly Vitrebond to both GICs and composite-Vit-l-ecence®. The lowest influence on cell’s metabolism on UMR-106 osteoblas-like cells was shown by Ketac Silver and the lowest influence on cell’s metabolism on NIH3T3 mouse fibroblast cells was shown by Fuji IX GP Fast. Statistical evaluation of sensitivity of cell lines UMR-106 osteoblast-like cells and NIH3T3 mouse fibroblast cells, using Mann-Whitney test, showed that NIH3T3 mouse fibroblast cells were more sensitive for the evaluation of cytotoxicity of dental materials. PMID:23198945

  6. Puncture-Healing Properties of Carbon Nanotube-Filled Ionomers

    NASA Technical Reports Server (NTRS)

    Ward, Thomas C.

    2003-01-01

    Ionomers are polymers that contain ionic groups in relatively low concentrations along the polymer backbone. These ionic groups, in the presence of oppositely charged ions, form aggregates that lead to novel physical properties of the polymer. React-A-Seal(trademark) and Surlyn(trademark) are poly(ethylene-co-methacrylic acid) (EMAA) ionomer-based materials and Nucrel(trademark) is the EMAA acid copolymer neutralized to produce Surlyn(trademark). React-A-Seal(trademark), Surlyn(trademark), and Nucrel(trademark) recover into their original shapes following a high impact puncture at velocities ranging from 300 to 1200 ft/s ('self-healing'). This self-healing process may be of great benefit in space applications where structures are exposed to matter impacts. A thermal IR camera indicated a temperature increase to 98 C for Nucrel(trademark) 925, Surlyn(trademark) 8940, React-A-Seal(trademark), and Surlyn(trademark) 8920 after initial penetration. To understand and generalize the observed phenomena, questions concerning the mechanism of the puncture resealing must be answered. One suggestion is that the elastic character of the melt created by the puncture drives the self-healing. This inference is based on the observed temperature rise of approx. 3 C above the melting temperature of the samples (approx. 95 C) during the impact. With the expectation of gaining additional insight into the self-healing phenomenon, a thermodynamic and viscoelastic investigation was conducted using primarily DSC and DMA. Surlyn(trademark) and React-A-Seal(trademark) showed the characteristic order-disorder transition at approx. 52 C that has been reported in literature. Master curves were constructed from the creep isotherms for the four EMAA samples. An aging study was performed to investigate the irreproducibility and "tailing effect" observed in the creep data. The aging study indicated that, with increased aging time and temperature, changes in the polyethylene matrix lead to

  7. An evaluation of microleakage of various glass ionomer based restorative materials in deciduous and permanent teeth: An in vitro study

    PubMed Central

    Singla, Teena; Pandit, I.K.; Srivastava, Nikhil; Gugnani, Neeraj; Gupta, Monika

    2011-01-01

    Aim To evaluate the microleakage of recently available glass ionomer based restorative materials (GC Fuji IX GP, GC Fuji VII, and Dyract) and compare their microleakage with the previously existing glass ionomer restorative materials (GC Fuji II LC) in primary and permanent teeth. Method One hundred and fifty (75 + 75) non-carious deciduous and permanent teeth were restored with glass ionomer based restorative materials after making class I cavities. Samples were subjected to thermocycling after storing in distilled water for 24 h. Two coats of nail polish were applied 1 mm short of restorative margins and samples sectioned buccolingually after storing in methylene blue dye for 24 h. Microleakage was assessed using stereomicroscope. Result Significant differences (P < 0.05) were found when inter group comparisons were done. Except when GC Fuji VII (Group III) was compared with GC Fuji II LC (Group II) and Dyract (Group IV), non-significant differences (P > 0.05) were observed. It was found that there was no statistically significant difference when the means of microleakage of primary teeth were compared with those of permanent teeth. Conclusions GC Fuji IX GP showed maximum microleakage and GC Fuji VII showed least microleakage. PMID:23960526

  8. Toward Reconciliation of STEM and SAXS Data from Ionomers by Investigating Gold Nanoparticles

    NASA Astrophysics Data System (ADS)

    Benetatos, Nicholas; Smith, Brian; Heiney, Paul; Winey, Karen

    2005-03-01

    We have recently pioneered the use of scanning transmission electron microscopy (STEM) for direct, model independent imaging of the nano-scale morphology of ionomers. To date, the sizes of ionic aggregates determined in STEM experiments are inconsistent with SAXS data interpreted by the Yarusso-Cooper model. To address this discrepancy we have investigated a pair of model nanoparticles (11 and 55 atom Au clusters) with both STEM and SAXS. Using this model system we have improved our method of measuring nanometer scale objects and evaluated the importance of STEM probe size and specimen thickness. While the size of the STEM probe was inconsequential, specimen thicker than 50 nm showed significant depreciation of image quality, which limits our ability to accurately measure particle size. SAXS was performed on dilute suspensions of nanoparticles and fit using a monodisperse, hard-sphere form factor model. For Au11, STEM finds a diameter of 1.3 nm + .14 and SAXS finds a diameter of 1.4 nm. Similarly, both STEM and SAXS determine a diameter of 1.7 nm for Au55. Analysis of these model systems have allowed us to evaluate several factors of potential importance in reconciling STEM and SAXS data from ionomers.

  9. Pulpal response to a new light-cured composite placed in etched glass-ionomer lined cavities.

    PubMed

    Hosoda, H; Inokoshi, S; Shimada, Y; Harnirattisai, C; Otsuki, M

    1991-01-01

    This study evaluated the pulp biocompatability of a new light-cured composite resin which was placed in etched glass-ionomer-lined cavities of monkey teeth. The pulpal response to this material was less than that to zinc-oxide eugenol cement in each observation period. Therefore this material seems to meet acceptable biocompatability standards in nonhuman primates.

  10. Research gaps identified during systematic reviews of clinical trials: glass-ionomer cements.

    PubMed

    Mickenautsch, Steffen

    2012-06-29

    To report the results of an audit concerning research gaps in clinical trials that were accepted for appraisal in authored and published systematic reviews regarding the application of glass-ionomer cements (GIC) in dental practice Information concerning research gaps in trial precision was extracted, following a framework that included classification of the research gap reasons: 'imprecision of information (results)', 'biased information', 'inconsistency or unknown consistency' and 'not the right information', as well as research gap characterization using PICOS elements: population (P), intervention (I), comparison (C), outcomes (O) and setting (S). Internal trial validity assessment was based on the understanding that successful control for systematic error cannot be assured on the basis of inclusion of adequate methods alone, but also requires empirical evidence about whether such attempt was successful. A comprehensive and interconnected coverage of GIC-related clinical topics was established. The most common reasons found for gaps in trial precision were lack of sufficient trials and lack of sufficient large sample size. Only a few research gaps were ascribed to 'Lack of information' caused by focus on mainly surrogate trial outcomes. According to the chosen assessment criteria, a lack of adequate randomisation, allocation concealment and blinding/masking in trials covering all reviewed GIC topics was noted (selection- and detection/performance bias risk). Trial results appear to be less affected by loss-to-follow-up (attrition bias risk). This audit represents an adjunct of the systematic review articles it has covered. Its results do not change the systematic review's conclusions but highlight existing research gaps concerning the precision and internal validity of reviewed trials in detail. These gaps should be addressed in future GIC-related clinical research.

  11. Two-body and three-body wear of glass ionomer cements.

    PubMed

    Kunzelmann, K H; Bürkle, V; Bauer, C

    2003-11-01

    Glass ionomer cements (GIC) have been modified in an attempt to improve their mechanical properties. The objective of the present paper was to compare the two-body and three-body wear of four modified GIC. The tested materials were Fuji IX (GC Corporation), Hi-Fi (Shofu) and Ketac Molar Aplicap (3M/ESPE). The cermet cement Ketac Silver Maxicap (3M/ESPE) was used as reference material. Two-body wear tests were carried out in the computer controlled 'artificial mouth' of the Munich Dental School, three-body wear was tested with the ACTA wear machine. The resulting average two-body wear rates (in microm) were: Fuji IX 327 (SD +/- 82) < Ketac Molar 379 (SD +/- 94) < Hi-Fi 376 (SD +/- 90) < Ketac silver 449 (SD +/- 127). The differences between the materials were significant (P < 0.05, ANOVA, modified LSD-test) with the exception of Ketac Molar and Hi-Fi. The average three-body wear rates (in microm) were: Hi-Fi 30 (SD +/- 10) < Ketac Molar +/- 42 (SD +/- 12) < Fuji IX 49 (SD +/- 14) < Ketac silver 73 (SD +/- 23). The difference between Ketac silver and the three other materials was significant (P < 0.05, ANOVA, modified LSD-test). No significant difference was calculated between Hi-Fi, Ketac Molar and Fuji IX. As Ketac Molar, Hi-Fi and Fuji IX show better wear resistance compared to Ketac silver both in occlusal-contact and contact-free areas, it may be assumed that the wear resistance of a glass ionomer cement may be improved more by changing the powder: liquid ratio than by incorporating silver particles into the glass powder.

  12. Investigation into the Depth of Cure of Resin-Modified Glass-Ionomer Restorative Materials

    DTIC Science & Technology

    2006-08-01

    al?2 studied the acid/base reaction of glass ionomer cements using Raman spectroscopy and confirmed the necessity of water availability for the acid...exchange layer." In the ion-exchange layer, Wilson et al.48 postulated the formation of an ionic bond between the polyacrylic acid and the hydroxyapatite ...investigators further detailed the interaction between the polyalkenoic acids and hydroxyapatite in a later report?’ The bonding of RMGI to dentin was

  13. Materials management information systems.

    PubMed

    1996-01-01

    The hospital materials management function--ensuring that goods and services get from a source to an end user--encompasses many areas of the hospital and can significantly affect hospital costs. Performing this function in a manner that will keep costs down and ensure adequate cash flow requires effective management of a large amount of information from a variety of sources. To effectively coordinate such information, most hospitals have implemented some form of materials management information system (MMIS). These systems can be used to automate or facilitate functions such as purchasing, accounting, inventory management, and patient supply charges. In this study, we evaluated seven MMISs from seven vendors, focusing on the functional capabilities of each system and the quality of the service and support provided by the vendor. This Evaluation is intended to (1) assist hospitals purchasing an MMIS by educating materials managers about the capabilities, benefits, and limitations of MMISs and (2) educate clinical engineers and information system managers about the scope of materials management within a healthcare facility. Because software products cannot be evaluated in the same manner as most devices typically included in Health Devices Evaluations, our standard Evaluation protocol was not applicable for this technology. Instead, we based our ratings on our observations (e.g., during site visits), interviews we conducted with current users of each system, and information provided by the vendor (e.g., in response to a request for information [RFI]). We divided the Evaluation into the following sections: Section 1. Responsibilities and Information Requirements of Materials Management: Provides an overview of typical materials management functions and describes the capabilities, benefits, and limitations of MMISs. Also includes the supplementary article, "Inventory Cost and Reimbursement Issues" and the glossary, "Materials Management Terminology." Section 2. The

  14. In vitro quantitative comparison of erosive potential of infant mouthwashes on glass ionomer cement

    PubMed Central

    da Silva, Aline-Bastos; Rapôso, Nayre-Maria-Lauande; Gomes, Isabella-Azevedo; Gonçalves, Letícia-Machado

    2018-01-01

    Background The widespread use of mouthwashes, specially in children, is a concern, since the long-term use may modify the topography of dental materials. However, this process still unclear regarding the wear related to infant mouthwashes on glass ionomer cement. Thus, the purpose of this investigation was evaluate the erosive potential of infant mouthwashes on glass ionomer cement specimens. Material and Methods Forty round-shaped specimens were divided into 4 groups (N=10) and submitted to erosive cycling for 15 days, being exposed 2X/day in the following children’s active agents mouthwash solutions: G1- cetylpyridinium chloride, G2- xylitol and triclosan and G3 - Malva sylvestris and xylitol. Prior to cycling, the specimens were submitted to the surface roughness measurement. After erosive cycling, the specimens were reanalyzed, and calculated the increase of roughness (∆Ra). Additionally, it was adopted distilled water as a negative control (G4). As an extra analysis, the mouthwashes had their pH values measured. The results were submitted to T-test and ANOVA followed by Tukey test at 5%. Results In relation to pH values, G2 presented the most acidic pH value (pH = 6.83) in comparison to other substances. Regarding the comparison of the final roughness values (R) among the groups, it was verified that the mouthwashes showed significant roughness increase in comparison to control group, especially to G3 group (Rf = 1.67 ± 0.14) as well the ΔRa values with statistical difference in comparison to distilled water. Still, with exception of control group outcome, an increase of roughness of each mouthwash was verified after the studied period. Conclusions Active agents present in infant mouthwashes were capable of roughness increased of glass ionomer cement surface, demonstrating an erosive potential of this material largely used in pediatric dentistry. Key words:Dental erosion, dental cements, mouthwash. PMID:29721219

  15. Influence of an alloy addition on the physical and clinical behaviour of glass ionomer cement

    NASA Astrophysics Data System (ADS)

    Abour, Mohamed Abour Bashir

    These in vitro studies compared the various properties of an experimental high powder liquid content glass ionomer cement (EXPT) with those of a metal addition GIC (Hi-Dense) and disperse phase amalgam (Dispersalloy). Bi-axial, four point flexural and compressive tests were used to evaluate strength. Six groups of ten specimens were constructed for each test for each material and allowed to set in an oven at 37°C for 60 minutes. Specimens were stored in distilled water at 37°C until testing at one day, one week, one, three, six months and year. It was found that the strength of Hi-Dense increased and then maintained over extended time, whereas the strength of EXPT showed a declined at 3 months. The bond strengths of the materials to both enamel and dentine were also evaluated. Ten groups of ten teeth, five for each surface for each glass ionomer materials, were prepared. Teeth were aligned leaving the enamel and dentine surfaces exposed. The mixed material was condensed into a cylinder placed on the appropriate surface. These specimens were also stored in distilled water at 37°C. It was found that Hi-Dense had a higher bond strength to enamel that increased with time. The bond strength to dentine was maintained over the test period. The erosion rate of the materials was evaluated using the lactic acid erosion test. Three groups of six specimens for each material were constructed and tested after one hour, one day and at six months. Each specimen was subjected to an impinging jet of lactic acid solution. The erosion rate was determined by weight loss and dimensional change. It was found that Hi-Dense had a high erosion resistance which was slightly better than the experimental material. The microleakage, around restorations prepared, using the glass ionomer materials, was evaluated after cyclical loading the restoration-tooth complex. It was found that there was less leakage around Hi-Dense than EXPT at both the cervical and occlusal margins. In a clinical

  16. Contaminant Permeation in the Ionomer-Membrane Water Processor (IWP) System

    NASA Technical Reports Server (NTRS)

    Kelsey, Laura K.; Finger, Barry W.; Pasadilla, Patrick; Perry, Jay

    2016-01-01

    The Ionomer-membrane Water Processor (IWP) is a patented membrane-distillation based urine brine water recovery system. The unique properties of the IWP membrane pair limit contaminant permeation from the brine to the recovered water and purge gas. A paper study was conducted to predict volatile trace contaminant permeation in the IWP system. Testing of a large-scale IWP Engineering Development Unit (EDU) with urine brine pretreated with the International Space Station (ISS) pretreatment formulation was then conducted to collect air and water samples for quality analysis. Distillate water quality and purge air GC-MS results are presented and compared to predictions, along with implications for the IWP brine processing system.

  17. Simulation study of poled low-water ionomers with different architectures

    NASA Astrophysics Data System (ADS)

    Allahyarov, Elshad; Taylor, Philip L.; Löwen, Hartmut

    2011-11-01

    The role of the ionomer architecture in the formation of ordered structures in poled membranes is investigated by molecular dynamics computer simulations. It is shown that the length of the sidechain Ls controls both the areal density of cylindrical aggregates Nc and the diameter of these cylinders in the poled membrane. The backbone segment length Lb tunes the average diameter Ds of cylindrical clusters and the average number of sulfonates Ns in each cluster. A simple empirical formula is noted for the dependence of the number density of induced rod-like aggregates on the sidechain length Ls within the parameter range considered in this study.

  18. Management Information System

    NASA Technical Reports Server (NTRS)

    1984-01-01

    New Automated Management Information Center (AMIC) employs innovative microcomputer techniques to create color charts, viewgraphs, or other data displays in a fraction of the time formerly required. Developed under Kennedy Space Center's contract by Boeing Services International Inc., Seattle, WA, AMIC can produce an entirely new informational chart in 30 minutes, or an updated chart in only five minutes. AMIC also has considerable potential as a management system for business firms.

  19. Medical-Information-Management System

    NASA Technical Reports Server (NTRS)

    Alterescu, Sidney; Friedman, Carl A.; Frankowski, James W.

    1989-01-01

    Medical Information Management System (MIMS) computer program interactive, general-purpose software system for storage and retrieval of information. Offers immediate assistance where manipulation of large data bases required. User quickly and efficiently extracts, displays, and analyzes data. Used in management of medical data and handling all aspects of data related to care of patients. Other applications include management of data on occupational safety in public and private sectors, handling judicial information, systemizing purchasing and procurement systems, and analyses of cost structures of organizations. Written in Microsoft FORTRAN 77.

  20. Ionomic profiling of Nicotiana langsdorffii wild-type and mutant genotypes exposed to abiotic stresses.

    PubMed

    Ardini, Francisco; Soggia, Francesco; Abelmoschi, Maria Luisa; Magi, Emanuele; Grotti, Marco

    2013-01-01

    To provide a new insight into the response of plants to abiotic stresses, the ionomic profiles of Nicotiana langsdorffii specimens have been determined before and after exposure to toxic metals (chromium) or drought conditions. The plants were genetically transformed with the rat glucocorticoid receptor (GR) or the gene for Agrobacterium rhizogenes rolC, because these modifications are known to produce an imbalance in phytohormone equilibria and a significant change in the defence response of the plant. Elemental profiles were obtained by developing and applying analytical procedures based on inductively coupled plasma atomic emission and mass spectrometry (ICP-AES/MS). In particular, the removal of isobaric interferences affecting the determination of Cr and V by ICP-MS was accomplished by use of a dynamic reaction cell, after optimization of the relevant conditions. The combined use of ICP atomic emission and mass spectrometry enabled the determination of 29 major and trace elements (Ba, Bi, Ca, Cd, Co, Cr, Cu, Eu, Fe, Ga, K, Li, Mg, Mn, Mo, Na, P, Pb, Pt, Rb, S, Sb, Sn, Sr, Te, V, W, Y, and Zn) in different parts of the plants (roots, stems, and leaves), with high accuracy and precision. Multivariate data processing and study of element distribution patterns provided new information about the ionomic response of the target organism to chemical treatment or water stress. Genetic modification mainly affected the distribution of Bi, Cr, Mo, Na, and S, indicating that these elements were involved in biochemical processes controlled by the GR or rolC genes. Chemical stress strongly affected accumulation of several elements (Ba, Ca, Fe, Ga, K, Li, Mn, Mo, Na, P, Pb, Rb, S, Sn, Te, V, and Zn) in different ways; for Ca, Fe, K, Mn, Na, and P the effect was quite similar to that observed in other studies after treatment with other transition elements, for example Cu and Cd. The effect of water deficit was less evident, mainly consisting in a decrease of Ba, Cr, Na, and Sr

  1. Thermo-cured glass ionomer cements in restorative dentistry.

    PubMed

    Gorseta, Kristina; Glavina, Domagoj

    2017-01-01

    Numerous positive properties of glass ionomer cements including biocompatibility, bioactivity, releasing of fluoride and good adhesion to hard dental tissue even under wet conditions and easy of handling are reasons for their wide use in paediatric and restorative dentistry. Their biggest drawbacks are the weaker mechanical properties. An important step forward in improving GIC's features is thermo-curing with the dental polymerization unit during setting of the material. Due to their slow setting characteristics the GIC is vulnerable to early exposure to moisture. After thermo curing, cements retain all the benefits of GIC with developed better mechanical properties, improved marginal adaptation, increased microhardness and shear bond strength. Adding external energy through thermocuring or ultrasound during the setting of conventional GIC is crucial to achieve faster and better initial mechanical properties. Further clinical studies are needed to confirm these findings.

  2. Simulation study of sulfonate cluster swelling in ionomers

    NASA Astrophysics Data System (ADS)

    Allahyarov, Elshad; Taylor, Philip L.; Löwen, Hartmut

    2009-12-01

    We have performed simulations to study how increasing humidity affects the structure of Nafion-like ionomers under conditions of low sulfonate concentration and low humidity. At the onset of membrane hydration, the clusters split into smaller parts. These subsequently swell, but then maintain constant the number of sulfonates per cluster. We find that the distribution of water in low-sulfonate membranes depends strongly on the sulfonate concentration. For a relatively low sulfonate concentration, nearly all the side-chain terminal groups are within cluster formations, and the average water loading per cluster matches the water content of membrane. However, for a relatively higher sulfonate concentration the water-to-sulfonate ratio becomes nonuniform. The clusters become wetter, while the intercluster bridges become drier. We note the formation of unusual shells of water-rich material that surround the sulfonate clusters.

  3. Archival Information Management System.

    DTIC Science & Technology

    1995-02-01

    management system named Archival Information Management System (AIMS), designed to meet the audit trail requirement for studies completed under the...are to be archived to the extent that future reproducibility and interrogation of results will exist. This report presents a prototype information

  4. Nuclear magnetic resonance investigation of dynamics in poly(ethylene oxide) based polyether-ester-sulfonate ionomers

    NASA Astrophysics Data System (ADS)

    Roach, David J.

    Nuclear magnetic resonance (NMR) spectroscopy has been utilized to investigate the dynamics of poly(ethylene oxide)-based lithium sulfonate ionomer samples that have low glass transition temperatures. 1H and 7Li spin-lattice relaxation times (T1) of the bulk polymer and lithium ions, respectively, were measured and analyzed in samples with a range of ion contents. The temperature dependence of T1 values along with the presence of minima in T1 as a function of temperature enabled correlation times and activation energies to be obtained for both the segmental motion of the polymer backbone and the hopping motion of lithium cations. Similar activation energies for motion of both the polymer and lithium ions in the samples with lower ion content indicate that the polymer segmental motion and lithium ion hopping motion are correlated in these samples, even though lithium hopping is about ten times slower than the segmental motion. A divergent trend is observed for correlation times and activation energies of the highest ion content sample with 100% lithium sulfonation due to the presence of ionic aggregation. Details of the polymer and cation dynamics on the nanosecond timescale are discussed and complement the findings of X-ray scattering and Quasi Elastic Neutron Scattering experiments. Polymer backbone dynamics of single ion conducting poly(ethylene oxide) (PEO)-based ionomer samples with low glass transition temperatures (T g) have been investigated using solid-state nuclear magnetic resonance (NMR). Experiments detecting 13C with 1H decoupling under magic angle spinning (MAS) conditions identified the different components and relative mobilities of the polymer backbone of a suite of. lithium- and sodium-containing ionomer samples with varying cation contents. Variable temperature (203-373 K) 1H-13C cross-polarization MAS (CP-MAS) experiments also provided qualitative assessment of the differences in the motions of the polymer backbone components as a function of

  5. Information Security Management - Part Of The Integrated Management System

    NASA Astrophysics Data System (ADS)

    Manea, Constantin Adrian

    2015-07-01

    The international management standards allow their integrated approach, thereby combining aspects of particular importance to the activity of any organization, from the quality management systems or the environmental management of the information security systems or the business continuity management systems. Although there is no national or international regulation, nor a defined standard for the Integrated Management System, the need to implement an integrated system occurs within the organization, which feels the opportunity to integrate the management components into a cohesive system, in agreement with the purpose and mission publicly stated. The issues relating to information security in the organization, from the perspective of the management system, raise serious questions to any organization in the current context of electronic information, reason for which we consider not only appropriate but necessary to promote and implement an Integrated Management System Quality - Environment - Health and Operational Security - Information Security

  6. Strategic management of health care information systems: nurse managers' perceptions.

    PubMed

    Lammintakanen, Johanna; Kivinen, Tuula; Saranto, Kaija; Kinnunen, Juha

    2009-01-01

    The aim of this study is to describe nurse managers' perceptions of the strategic management of information systems in health care. Lack of strategic thinking is a typical feature in health care and this may also concern information systems. The data for this study was collected by eight focus group interviews including altogether 48 nurse managers from primary and specialised health care. Five main categories described the strategic management of information systems in health care; IT as an emphasis of strategy; lack of strategic management of information systems; the importance of management; problems in privacy protection; and costs of IT. Although IT was emphasised in the strategies of many health care organisations, a typical feature was a lack of strategic management of information systems. This was seen both as an underutilisation of IT opportunities in health care organisations and as increased workload from nurse managers' perspective. Furthermore, the nurse managers reported that implementation of IT strengthened their managerial roles but also required stronger management. In conclusion, strategic management of information systems needs to be strengthened in health care and nurse managers should be more involved in this process.

  7. Medical Information Management System

    NASA Technical Reports Server (NTRS)

    Alterescu, S.; Hipkins, K. R.; Friedman, C. A.

    1979-01-01

    On-line interactive information processing system easily and rapidly handles all aspects of data management related to patient care. General purpose system is flexible enough to be applied to other data management situations found in areas such as occupational safety data, judicial information, or personnel records.

  8. Morphological Changes Of The Root Surface And Fracture Resistance After Treatment Of Root Fracture By CO2 Laser And Glass Ionomer Or Mineral Trioxide Aggregates

    NASA Astrophysics Data System (ADS)

    Badr, Y. A.; Abd El-Gawad, L. M.; Ghaith, M. E.

    2009-09-01

    This in vitro study evaluates the morphological changes of the root surface and fracture resistance after treatment of root cracks by CO2 laser and glass Ionomer or mineral trioxide aggregates (MTA). Fifty freshly extracted human maxillary central incisor teeth with similar dimension were selected. Crowns were sectioned at the cemento-enamel junction, and the lengths of the roots were adjusted to 13 mm. A longitudinal groove with a dimension of 1×5 mm2 and a depth of 1.5 mm was prepared by a high speed fissure bur on the labial surface of the root. The roots were divided into 5 groups: the 10 root grooves in group 1 were remained unfilled and were used as a control group. The 10 root grooves in group 2 were filled with glass Ionomer, 10 root grooves in group 3 were filled with MTA, the 10 root grooves in group 4 were filled with glass Ionomer and irradiated by CO2 laser and the 10 root grooves in group 5 were filled with MTA and irradiated with CO2 laser. Scanning electron microscopy was performed for two samples in each group. Tests for fracture strength were performed using a universal testing machine and a round tip of a diameter of 4 mm. The force was applied vertically with a constant speed of 1 mm min 1. For each root, the force at the time of fracture was recorded in Newtons. Results were evaluated statistically with ANOVA and Turkey's Honestly Significant Difference (HSD) tests. SEM micrographs revealed that the melted masses and the plate-like crystals formed a tight Chemical bond between the cementum and glass Ionomer and melted masses and globular like structure between cementum and MTA. The mean fracture resistance was the maximum fracture resistance in group 5 (810.8 N). Glass Ionomer and MTA with the help of CO2 laser can be an alternative to the treatment of tooth crack or fracture. CO2 laser increase the resistance of the teeth to fracture.

  9. Graphene-supported platinum catalyst prepared with ionomer as surfactant for anion exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Zeng, L.; Zhao, T. S.; An, L.; Zhao, G.; Yan, X. H.; Jung, C. Y.

    2015-02-01

    In this work, we have synthesized an ionomer-coated graphene-supported platinum catalyst for anion exchange membrane fuel cells. Unlike the common surfactant stabilized colloidal method, we employ a home-made anion exchange ionomer (AEI), namely quaternary ammonia poly (2, 6-dimethyl-1, 4-phenylene oxide) (QAPPO), as the surfactant. The AEI coated on reduced graphene oxide (rGO) surfaces serves as a stabilizer to anchor the platinum precursor on rGO surfaces due to electrostatic interactions. As a result, platinum nanoparticles (Pt NPs) can be easily deposited onto rGO surfaces with a uniform distribution. The remarkable feature of the present synthesis method is that the surfactant, the coated AEI, does not need to be removed from the catalyst, but serves as hydroxide-conductive paths in the catalyst layer, leading to enhanced triple phase boundaries. It is demonstrated that the use of the catalyst obtained with the present method enables a H2/O2 AEMFC to yield a peak power density of 264.8 mW cm-2 at 60 °C, which is 30% higher than that produced from the same fuel cell but with the use of the catalyst synthesized by the conventional synthesis method.

  10. Resin-modified glass ionomer cements: fluoride release and influence on Streptococcus mutans growth.

    PubMed

    Friedl, K H; Schmalz, G; Hiller, K A; Shams, M

    1997-02-01

    The aims of the present study were to measure the fluoride release of 1 glass ionomer cement, 1 cermet, 3 resin-modified glass ionomer cements and 1 compomer, and to determine the influence of each material on bacterial growth. Test specimens were eluted in saline for 180 days. Every 2 days, the specimens were transferred into fresh saline and the fluoride content of the solution was measured. Furthermore, 48-h, 14-d, 90-d, and 180-d eluates were inoculated with Streptococcus mutans and bacterial growth was recorded nephelometrically. Fluoride release dropped significantly over time for each material with values between 6.2 (Ketac-Silver) and 29.3 (Photac-Fil) ppm after 48 h to values between 0.6 (Ketac-Silver) and 1.7 (Ketac-Fil, Vitremer) ppm after 180 days. Each material reduced bacterial growth at each time of examination, but the effect decreased significantly over time with a maximum growth of 71.7% (Ketac-Fil) to 85.6% (Ketac-Silver) after 48 h and 94.7 (Vitremer) to 99.0% (Ketac-Silver) after 180 days (growth control = 100%). Both Ketac-Silver and Dyract showed a significantly lower inhibiting effect on bacterial growth than the other materials. The tested materials showed a good correlation between fluoride release and influence on bacterial growth. However, both effects dropped dramatically over the 180-days period.

  11. [Bonding of visible light cured composite resins to glass ionomer and Cermet cements].

    PubMed

    Kakaboura, A; Vougiouklakis, G

    1990-04-01

    The "sandwich" technique involves combination of composite resins to etched glassionomer cements, is used today in restorative dentistry. The purpose of this study is to evaluate the bond strength between several composite resins and glass ionomer or cerment cements. Cylindrical specimens of the cements Ketac-Silver, Ionobond and GC-Lining Ce-ment were inserted in a mold and their flat free surfaces were etched for 30". Cylindrical plastic tubes were set upon each one of these surfaces and filled with the Composite resins Durafill, Brilliant Lux, Estilux posterior, Estilux posterior CVS and Herculite XR. Half of the specimens transferred in tap water for 24 hours and the others after thermocycling in the first month, kept for 4 months. Shear bond strengths were determined in Monsanto Testing Machine and some fractured surfaces were examined under SEM. The results of this investigation indicate that this technique produces bond strengths between composite resins and glassioners and the combination type of resin and type of cement, affects the values of the strength. Glass cermeet--small particle resin provides the most effective strength and glass ionomer--microfill resins the least. Storage time and thermocycling don't significantly effect the bond strength. SEM examination showed that all fracture failures were obtained in the cement while the opposite resin surfaces were covered with particles of the cements.

  12. Bond Strength of Composite to Dentin using Resin-Modified Glass Ionomers as Bonding Agents

    DTIC Science & Technology

    2016-03-02

    59 MDW/SGVU SUBJECT: Professional Presentation Approval 2 MAR 20 16 l. Your paper, entitl ed Bond Strength of Composite to Dentin using Resin...Modified G lass Ionomers as Bonding Agents presented at Journal of Dental Research with MDWI 41- 108, and has been assigned local fi le #16086. 2...Vandewalle /Civ/SGDTG (59th CSPG/SGVU) DECS I 5-009 PROTOCOL TITLE Bond Strength of Composite to Dentin using Resin-modified Glass lonomers as

  13. [Wound information management system: a standardized scheme for acquisition, storage and management of wound information].

    PubMed

    Liu, Hu; Su, Rong-jia; Wu, Min-jie; Zhang, Yi; Qiu, Xiang-jun; Feng, Jian-gang; Xie, Ting; Lu, Shu-liang

    2012-06-01

    To form a wound information management scheme with objectivity, standardization, and convenience by means of wound information management system. A wound information management system was set up with the acquisition terminal, the defined wound description, the data bank, and related softwares. The efficacy of this system was evaluated in clinical practice. The acquisition terminal was composed of the third generation mobile phone and the software. It was feasible to get access to the wound information, including description, image, and therapeutic plan from the data bank by mobile phone. During 4 months, a collection of a total of 232 wound treatment information was entered, and accordingly standardized data of 38 patients were formed automatically. This system can provide standardized wound information management by standardized techniques of acquisition, transmission, and storage of wound information. It can be used widely in hospitals, especially primary medical institutions. Data resource of the system makes it possible for epidemiological study with large sample size in future.

  14. The Next-Generation Information Manager.

    ERIC Educational Resources Information Center

    Varian, Hal R.

    1997-01-01

    Describes the Master's program at the University of California at Berkeley's new School of Information Management and Systems, highlighting courses in information organization and retrieval, communication and networking, users and society, and management of information organization and systems; and the school's continuing education for information…

  15. Information support for health information management in regional Sri Lanka: health managers' perspectives.

    PubMed

    Ranasinghe, Kaduruwane Indika; Chan, Taizan; Yaralagadda, Prasad

    Good management, supported by accurate, timely and reliable health information, is vital for increasing the effectiveness of Health Information Systems (HIS). When it comes to managing the under-resourced health systems of developing countries, information-based decision making is particularly important. This paper reports findings of a self-report survey that investigated perceptions of local health managers (HMs) of their own regional HIS in Sri Lanka. Data were collected through a validated, pre-tested postal questionnaire, and distributed among a selected group of HMs to elicit their perceptions of the current HIS in relation to information generation, acquisition and use, required reforms to the information system and application of information and communication technology (ICT). Results based on descriptive statistics indicated that the regional HIS was poorly organised and in need of reform; that management support for the system was unsatisfactory in terms of relevance, accuracy, timeliness and accessibility; that political pressure and community and donor requests took precedence over vital health information when management decisions were made; and use of ICT was unsatisfactory. HIS strengths included user-friendly paper formats, a centralised planning system and an efficient disease notification system; weaknesses were lack of comprehensiveness, inaccuracy, and lack of a feedback system. Responses of participants indicated that HIS would be improved by adopting an internationally accepted framework and introducing ICT applications. Perceived barriers to such improvements were high initial cost of educating staff to improve computer literacy, introduction of ICTs, and HIS restructure. We concluded that the regional HIS of Central Province, Sri Lanka had failed to provide much-needed information support to HMs. These findings are consistent with similar research in other developing countries and reinforce the need for further research to verify causes of

  16. Influence of electrostatic interactions on the morphology and properties of blends containing perfluorinated ionomers

    NASA Astrophysics Data System (ADS)

    Taylor, Eric Paul

    2002-01-01

    The first goal of this research project was to investigate the influence of the electrostatic interactions within the ion-containing domains of Nafion RTM perfluorosulfonate ionomer (PFSI) on the morphology and resultant properties of blend systems with poly(propylene imine) dendrimers of a variety of generational sizes and poly(vinylidene fluoride) (PVDF). Perfluorosulfonate ionomers (PFSIs) are a commercially successful class of semi-crystalline, ion-containing polymers whose most extensive application is in use as a polymer electrolytic membrane in fuel cell applications. NafionRTM was blended and high temperature solution processed with poly(propylene imine) dendrimer as the minor component in order to increase the efficiency of direct methanol fuel cells by decreasing methanol crossover without significant loss of protonic conductivity. The preferential insertion of the dendrimer into the ionic cluster due to proton transfer reactions and the creation of ammonium-sulfonate ion pairs served to alter the transport properties through the ionic network of the membrane. In the second major system investigated, blends of poly(vinylidene fluoride) (PVDF) with NafionRTM, a perfluorosulfonate ionomer, have been prepared and examined in terms of the crystallization kinetics and crystal morphology of the PVDF component in the blend. DSC analysis showed faster rates of bulk crystallization when PVDF was crystallized in the presence of Na+-form NafionRTM suggesting a high degree of phaseseparation in this blend system and an increase in the nucleation density. NafionRTM neutralized with alkylammonium-form counterions display an increase in blend compatibility with PVDF with an increase in the alkylammonium counterion size. As the alkylammonium counterion size increases, the strength of the electrostatic network within the ionic domains of Nafion RTM decrease resulting in a reduction in the driving force for ionic aggregation. Thus, a decrease is observed in the crystal

  17. Challenges to managing natural resource information

    Treesearch

    William L. Halvorson

    2005-01-01

    One of the most important issues facing resource managers today is that of information. In order to handle the numerous and diverse requirements for information, landscape-scale information management systems are needed that allow individual land management units to view their resource information in a regional context. The characteristics of such a system are: (1) the...

  18. The room temperature annealing peak in ionomers: Ionic crystallites or water absorption

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Goddard, R.J.; Grady, B.P.; Cooper, S.L.

    1994-03-28

    A quaternized diol, 3-(trimethylammonio)-1,2-propanediol neutralized with either bromine or iodine, was used to produce a polyurethane cationomer with a poly(tetramethylene oxide) soft segment and a 4,4[prime]-diphenylmethane diisocyanate hard segment. If those cationomers were annealed at room temperature for a period of approximately 1 month in a desiccator filled with dry CaSO[sub 4], differential scanning calorimetry (DSC) studies showed an endotherm centered near 70 C which was not present in the unannealed polymer and did not reappear upon subsequent cooling and heating cycles in the DSC. Some authors have suggested that a very similar endotherm found in other ionomers, most notablymore » ethylene-methacrylic acid (E-MAA) copolymer ionomers, was due to an order-disorder transition within the ionic aggregates, i.e. ionic crystallite melting. In order to isolate the origin of this endotherm, the local environment around the anion in compression molded bromine neutralized samples was measured using the extended X-ray absorption fine-structure (EXAFS) technique. By measuring the change in the local environment over the temperature range corresponding to the DSC endotherm, it has been shown that this endotherm corresponds to water leaving the bromine coordination shell, rather than ionic crystallite melting. Other studies which include thoroughly drying the material in a vacuum oven below the transition temperature to remove the water suggest that the endotherm is due to the energetic change associated with water leaving the coordination environment of the anion in combination with water vaporization.« less

  19. Information management, today and tomorrow. [acquisition, manipulation, transfer, and display of information

    NASA Technical Reports Server (NTRS)

    Pryor, H. E.

    1975-01-01

    Current problems and future trends in information management are briefly summarized in relation to scientific and technical information management systems and management of management information (planning, marketing, and operations).

  20. Toward information management in corporations (2)

    NASA Astrophysics Data System (ADS)

    Shibata, Mitsuru

    If construction of inhouse information management systems in an advanced information society should be positioned along with the social information management, its base making begins with reviewing current paper filing systems. Since the problems which inhere in inhouse information management systems utilizing OA equipments also inhere in paper filing systems, the first step toward full scale inhouse information management should be to grasp and solve the fundamental problems in current filing systems. This paper describes analysis of fundamental problems in filing systems, making new type of offices and analysis of improvement needs in filing systems, and some points in improving filing systems.

  1. Toward information management in corporations (11)

    NASA Astrophysics Data System (ADS)

    Yamanaka, Yoshiaki

    PC/WS's proleferation on to the despk top of endusers result in high level of computer literacies to them, networking between host/departmental/personal equipments also prevails entire organizations. In these circumstance, information architecture and environments will rapidly change in 1990's. Information manager's roles would change in these informated organization. Their roles and responsibilities will shifts to similer ones as other managers roles like human/asset/purchase/financial resources management. Sprit responsibilities between Cief Information Officer and MIS manager also will be seen in 1990's.

  2. Effect of flowable composite liner and glass ionomer liner on class II gingival marginal adaptation of direct composite restorations with different bonding strategies.

    PubMed

    Aggarwal, Vivek; Singla, Mamta; Yadav, Suman; Yadav, Harish

    2014-05-01

    The purpose of the present study was to comparatively evaluate the effect of flowable composite resin liner and resin modified glass ionomer liner on gingival marginal adaptation of class II cavities restored using three bonding agents (Single Bond 3M ESPE, One Coat Self Etching Bond Coltene Whaledent; Adper Easy Bond Self-Etch Adhesive 3M ESPE) and respective composite resins, under cyclic loading. The marginal adaptation was evaluated in terms of 'continuous margin' (CM) at the gingival margin. Ninety class II cavities with margins extending 1mm below the cement-enamel junction were prepared in extracted mandibular third molars. The samples were divided into three groups: no liner placement; 0.5-1mm thick flowable resin liner placement (Filtek Z350 XT flowable resin) on gingival floor and; light cure glass ionomer (Ketac N100) liner. The groups were further subdivided into three sub-groups on the basis of the bonding agents used. Cavities were restored with composite resins (Z350 for Single Bond and Adper Easy Bond; and Synergy D6 Universal, for One Coat Self Etching Bond) in 2mm increments and the samples were mechanically loaded (60N, 1,50,000 cycles). Marginal adaptation was evaluated using a low vacuum scanning electron microscope. Statistical analysis was done with two way ANOVA with Holm-Sidak's correction for multiple comparisons. Placement of flowable composite liner significantly improved the CM values of Single Bond (78±11%) and One Coat Self Etching Bond (77±9%) compared with no liner group, but the values of CM of Adper Easy Bond were not improved (61±12%). Placement of glass ionomer liner significantly improved the values of CM in all the sub-groups (78±9%, 72±10% and 77±10% for Single Bond, One Coat Self Etching Bond & Adper Easy Bond respectively) compared with no liner group. Placement of liners improved the values of 'continuous margin' in the gingival floor of the proximal cavities restored with composite resins using different bonding

  3. Research review for information management

    NASA Technical Reports Server (NTRS)

    Bishop, Peter C.

    1988-01-01

    The goal of RICIS research in information management is to apply currently available technology to existing problems in information management. Research projects include the following: the Space Business Research Center (SBRC), the Management Information and Decision Support Environment (MIDSE), and the investigation of visual interface technology. Several additional projects issued reports. New projects include the following: (1) the AdaNET project to develop a technology transfer network for software engineering and the Ada programming language; and (2) work on designing a communication system for the Space Station Project Office at JSC. The central aim of all projects is to use information technology to help people work more productively.

  4. Information management challenges of the EOS Data and Information System

    NASA Technical Reports Server (NTRS)

    Mcdonald, Kenneth R.; Blake, Deborah J.

    1991-01-01

    An overview of the current information management concepts that are embodied in the plans for the Earth Observing System Data and Information System (EOSDIS) is presented, and some of the technology development and application areas that are envisioned to be particularly challenging are introduced. The Information Management System (IMS) is the EOSDIS element that provides the primary interface between the science users and the data products and services of EOSDIS. The goals of IMS are to define a clear and complete set of functional requirements and to apply innovative methods and technologies to satisfy them. The information management functions are described in detail, and some applicable technolgies are discussed. Some of the general issues affecting the successful development and operation of the information management element are addressed.

  5. Clinical attachment level gain and bone regeneration around a glass ionomer restoration on root surface wall of periodontal pocket

    PubMed Central

    Biniraj, K. R.; Sagir, Mohammed; Sunil, M. M.; Janardhanan, Mahija

    2012-01-01

    A case describing perio-restorative management of an accidental trauma in the mid portion of root on an upper left canine tooth following an ostectomy surgery is presented here. The traumatized root area was undergoing fast resorption and a chronic periodontal abscess had developed in relation to the lesion. The article illustrates the clinical and radiographic photo series of a periodontal flap surgery done to gain access into a subgingival region for the placement of Glass ionomer restoration on the root and its periodic follow up. The clinical condition of the area suggests 8 mm clinical attachment gain over the restoration and the review radiographs at definite intervals up to 18 months revealed evidence of consistent bone regeneration around the restoration. The article also highlights the various other possibilities, where this restorative material can be effectively used in conjunction with periodontal surgical procedures. PMID:23162344

  6. NICA project management information system

    NASA Astrophysics Data System (ADS)

    Bashashin, M. V.; Kekelidze, D. V.; Kostromin, S. A.; Korenkov, V. V.; Kuniaev, S. V.; Morozov, V. V.; Potrebenikov, Yu. K.; Trubnikov, G. V.; Philippov, A. V.

    2016-09-01

    The science projects growth, changing of the efficiency criteria during the project implementation require not only increasing of the management specialization level but also pose the problem of selecting the effective planning methods, monitoring of deadlines and interaction of participants involved in research projects. This paper is devoted to choosing the project management information system for the new heavy-ion collider NICA (Nuclotron based Ion Collider fAcility). We formulate the requirements for the project management information system with taking into account the specifics of the Joint Institute for Nuclear Research (JINR, Dubna, Russia) as an international intergovernmental research organization, which is developed on the basis of a flexible and effective information system for the NICA project management.

  7. Glass ionomer ART sealants in Chinese school children-6-year results.

    PubMed

    Holmgren, Christopher J; Lo, Edward C M; Hu, Deyu

    2013-09-01

    To evaluate longitudinally ART sealants placed in Chinese school children under field conditions. 191 ART sealants were placed in 140 children, aged 11-14 years, by five assistant dentists in four secondary schools in Deyang, Sichuan Province, China. Teeth selected for sealing were those with pits and fissures that were deep or showing early enamel caries. Teeth were excluded if there was obvious cavitation extending into dentine. Standard instruments and procedures for ART sealants were used. The material used was a high-viscosity glass-ionomer (Ketac-Molar, 3MESPE) that was inserted into the pits and fissures with the "press-finger" technique. The status of the sealants was evaluated annually over 6 years after placement by the same examiner who was not involved in the placement of the sealants using explorers, mouth-mirrors and an intra-oral fibre-optic light. No missing sealants were replaced during the study. 107 sealants (56% of the original) were examined after 6 years. The cumulative survival rates of the sealants (partially or fully retained) after 2, 4 and 6 years were 79%, 68% and 59%, respectively. Caries prevention lagged the fall in sealant survival but remained high throughout the study period, being over 90% in the first 4 years and 85% after 6 years. ART sealants placed under field conditions in Chinese schoolchildren have a high retention rate. Missing sealants should be replaced to maintain their preventive efficacy. The sealing of pits and fissures can be an effective caries preventive approach. Resin-based sealants have the disadvantage in that they require an optimal level of moisture control during placement. In children and in outreach situations glass ionomer ART sealants, which are more moisture tolerant, can offer a viable alternative. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Information flow in the DAMA project beyond database managers: information flow managers

    NASA Astrophysics Data System (ADS)

    Russell, Lucian; Wolfson, Ouri; Yu, Clement

    1996-12-01

    To meet the demands of commercial data traffic on the information highway, a new look at managing data is necessary. One projected activity, sharing of point of sale information, is being considered in the Demand Activated Manufacturing Project (DAMA) of the American Textile Partnership (AMTEX) project. A scenario is examined in which 100 000 retail outlets communicate over a period of days. They provide the latest estimate of demand for sewn products across a chain of 26 000 suppliers through the use of bill of materials explosions at four levels of detail. Enabling this communication requires an approach that shares common features with both workflows and database management. A new paradigm, the information flow manager, is developed to handle this situation, including the case where members of the supply chain fail to communicate and go out of business. Techniques for approximation are introduced so as to keep estimates of demand as current as possible.

  9. Ionomer equivalent weight structuring in the cathode catalyst layer of automotive fuel cells: Effect on performance, current density distribution and electrochemical impedance spectra

    NASA Astrophysics Data System (ADS)

    Herden, Susanne; Hirschfeld, Julian A.; Lohri, Cyrill; Perchthaler, Markus; Haase, Stefan

    2017-10-01

    To improve the performance of proton exchange membrane fuel cells, membrane electrode assemblies (MEAs) with segmented cathode electrodes have been manufactured. Electrodes with a higher and lower ionomer equivalent weight (EW) were used and analyzed using current density and temperature distribution, polarization curve, temperature sweep and electrochemical impedance spectroscopy measurements. These were performed using automotive metallic bipolar plates and operating conditions. Measurement data were used to manufacture an optimized segmented cathode electrode. We were able to show that our results are transferable from a small scale hardware to automotive application and that an ionomer EW segmentation of the cathode leads to performance improvement in a broad spectrum of operating conditions. Furthermore, we confirmed our results by using in-situ electrochemical impedance spectroscopy.

  10. In vitro mechanical stimulation facilitates stress dissipation and sealing ability at the conventional glass ionomer cement-dentin interface.

    PubMed

    Toledano, Manuel; Osorio, Raquel; Osorio, Estrella; Cabello, Inmaculada; Toledano-Osorio, Manuel; Aguilera, Fátima S

    2018-06-01

    The aim of this study was to evaluate the induced changes in the chemical and mechanical performance at the glass-ionomer cement-dentin interface after mechanical load application. A conventional glass-ionomer cement (GIC) (Ketac Bond), and a resin-modified glass-ionomer cement (RMGIC) (Vitrebond Plus) were used. Bonded interfaces were stored in simulated body fluid, and then tested or submitted to the mechanical loading challenge. Different loading waveforms were applied: No cycling, 24 h cycled in sine or loaded in sustained hold waveforms. The cement-dentin interface was evaluated using a nano-dynamic mechanical analysis, estimating the complex modulus and tan δ. Atomic Force Microscopy (AFM) imaging, Raman analysis and dye assisted confocal microscopy evaluation (CLSM) were also performed. The complex modulus was lower and tan delta was higher at interfaces promoted with the GIC if compared to the RMGIC unloaded. The conventional GIC attained evident reduction of nanoleakage. Mechanical loading favored remineralization and promoted higher complex modulus and lower tan delta values at interfaces with RMGIC, where porosity, micropermeability and nanoleakage were more abundant. Mechanical stimuli diminished the resistance to deformation and increased the stored energy at the GIC-dentin interface. The conventional GIC induced less porosity and nanoleakage than RMGIC. The RMGIC increased nanoleakage at the porous interface, and dye sorption appeared within the cement. Both cements created amorphous and crystalline apatites at the interface depending on the type of mechanical loading. Remineralization, lower stress concentration and resistance to deformation after mechanical loading improved the sealing of the GIC-dentin interface. In vitro oral function will favor high levels of accumulated energy and permits micropermeability at the RMGIC-dentin interface which will become remineralized. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. 7 CFR 2903.16 - Organizational management information.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Organizational management information. 2903.16... § 2903.16 Organizational management information. Specific management information relating to an applicant... a grant identified under this program, if such information has not been provided previously. Copies...

  12. Air System Information Management

    NASA Technical Reports Server (NTRS)

    Filman, Robert E.

    2004-01-01

    I flew to Washington last week, a trip rich in distributed information management. Buying tickets, at the gate, in flight, landing and at the baggage claim, myriad messages about my reservation, the weather, our flight plans, gates, bags and so forth flew among a variety of travel agency, airline and Federal Aviation Administration (FAA) computers and personnel. By and large, each kind of information ran on a particular application, often specialized to own data formats and communications network. I went to Washington to attend an FAA meeting on System-Wide Information Management (SWIM) for the National Airspace System (NAS) (http://www.nasarchitecture.faa.gov/Tutorials/NAS101.cfm). NAS (and its information infrastructure, SWIM) is an attempt to bring greater regularity, efficiency and uniformity to the collection of stovepipe applications now used to manage air traffic. Current systems hold information about flight plans, flight trajectories, weather, air turbulence, current and forecast weather, radar summaries, hazardous condition warnings, airport and airspace capacity constraints, temporary flight restrictions, and so forth. Information moving among these stovepipe systems is usually mediated by people (for example, air traffic controllers) or single-purpose applications. People, whose intelligence is critical for difficult tasks and unusual circumstances, are not as efficient as computers for tasks that can be automated. Better information sharing can lead to higher system capacity, more efficient utilization and safer operations. Better information sharing through greater automation is possible though not necessarily easy.

  13. Antibacterial and physical properties of EGCG-containing glass ionomer cements.

    PubMed

    Hu, Jieqiong; Du, Xijin; Huang, Cui; Fu, Dongjie; Ouyang, Xiaobai; Wang, Yake

    2013-10-01

    To evaluate the effect of the addition of epigallocatechin-3-gallate (EGCG) on the antibacterial and physical properties of glass ionomer cement (GIC). A conventional GIC, Fuji IX, was used as a control. EGCG was incorporated into GIC at 0.1% (w/w) and used as the experimental group. Chlorhexidine (CHX) was added into GIC at 1% (w/w) as a positive control. The anti-biofilm effect of the materials was assessed by a colorimetric technique (MTT assay) and scanning electron microscopy (SEM). The leaching antibacterial activity of the materials on Streptococcus mutans was evaluated by an agar-diffusion test. The flexural strength of the materials was evaluated using a universal testing machine and the surface microhardness was measured using a microhardness tester. The fluoride-releasing property of the materials was tested by ion chromatography. The optical density (OD) values of the GIC-EGCG group were significantly decreased at 4h compared with the GIC group, but only a slightly decreased tendency was observed at 24h (P>0.05). No inhibition zones were detected in the GIC group during the study period. Significant differences were found between each group (P<0.05). Compared with the control group, there was a significant increase in the flexural strength and surface microhardness for the GIC-EGCG group (P<0.05). The fluoride ion release was not influenced by EGCG-incorporation (P>0.05). These findings suggested that GIC-containing 0.1% (w/w) EGCG is a promising restorative material with improved mechanical properties and a tendency towards preferable antibacterial properties. Modification of the glass ionomer cements with EGCG to improve the antibacterial and physical properties showed some encouraging results. This suggested that the modification of GIC with EGCG might be an effective strategy to be used in the dental clinic. However, this was only an in vitro study and clinical trials would need to verify true outcomes. Copyright © 2013 Elsevier Ltd. All rights

  14. 75 FR 29572 - Information Collection; Grazing Management

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-26

    ... Control Number 1004-0019] Information Collection; Grazing Management AGENCY: Bureau of Land Management... submitted an information collection request to the Office of Management and Budget (OMB) for a 3-year... INFORMATION: Title: Grazing Management (43 CFR 4120). OMB Number: 1004-0019. Forms: 4120-6 (Cooperative Range...

  15. 42 CFR 486.330 - Condition: Information management.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 5 2012-10-01 2012-10-01 false Condition: Information management. 486.330 Section...: Information management. An OPO must establish and use an electronic information management system to maintain the required medical, social and identifying information for every donor and transplant beneficiary...

  16. 42 CFR 486.330 - Condition: Information management.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 5 2013-10-01 2013-10-01 false Condition: Information management. 486.330 Section...: Information management. An OPO must establish and use an electronic information management system to maintain the required medical, social and identifying information for every donor and transplant beneficiary...

  17. 42 CFR 486.330 - Condition: Information management.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 5 2014-10-01 2014-10-01 false Condition: Information management. 486.330 Section...: Information management. An OPO must establish and use an electronic information management system to maintain the required medical, social and identifying information for every donor and transplant beneficiary...

  18. Biological information systems: Evolution as cognition-based information management.

    PubMed

    Miller, William B

    2018-05-01

    An alternative biological synthesis is presented that conceptualizes evolutionary biology as an epiphenomenon of integrated self-referential information management. Since all biological information has inherent ambiguity, the systematic assessment of information is required by living organisms to maintain self-identity and homeostatic equipoise in confrontation with environmental challenges. Through their self-referential attachment to information space, cells are the cornerstone of biological action. That individualized assessment of information space permits self-referential, self-organizing niche construction. That deployment of information and its subsequent selection enacted the dominant stable unicellular informational architectures whose biological expressions are the prokaryotic, archaeal, and eukaryotic unicellular forms. Multicellularity represents the collective appraisal of equivocal environmental information through a shared information space. This concerted action can be viewed as systematized information management to improve information quality for the maintenance of preferred homeostatic boundaries among the varied participants. When reiterated in successive scales, this same collaborative exchange of information yields macroscopic organisms as obligatory multicellular holobionts. Cognition-Based Evolution (CBE) upholds that assessment of information precedes biological action, and the deployment of information through integrative self-referential niche construction and natural cellular engineering antecedes selection. Therefore, evolutionary biology can be framed as a complex reciprocating interactome that consists of the assessment, communication, deployment and management of information by self-referential organisms at multiple scales in continuous confrontation with environmental stresses. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Developing an Information and Records Management Program.

    ERIC Educational Resources Information Center

    Rutledge, Juli G.; Kartis, Alexia M.

    1984-01-01

    The need for information controls for college records management programs and the elements of program organization, planning, and management are discussed. Conditions at institutions that indicate a flaw in information control are identified, along with the benefits of a sound records management program. The management of an information and…

  20. 42 CFR 486.330 - Condition: Information management.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Condition: Information management. 486.330 Section...: Information management. An OPO must establish and use an electronic information management system to maintain the required medical, social and identifying information for every donor and transplant recipient and...

  1. 42 CFR 486.330 - Condition: Information management.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 5 2011-10-01 2011-10-01 false Condition: Information management. 486.330 Section...: Information management. An OPO must establish and use an electronic information management system to maintain the required medical, social and identifying information for every donor and transplant recipient and...

  2. Management of Information Technology Access Controls

    DTIC Science & Technology

    1991-01-01

    Management Information Systems , (New York: American Elsevier Publishing Company, 1968), 8. 2. Webster’s Third New International Dictionary, Unabridged... Management Information Systems (New York: American Elsevier Publishing company, 1968), 37. 5. Ibid. 6. Ibid. 7. Gerald M. Ward and Jonathan D. Harris, "Data...Controls: A Visual Approach Through Integrated Management Information Systems . New York: American Elsevier Publishing Company, 1968. Brancheau, James C

  3. Enterprise Information Lifecycle Management

    DTIC Science & Technology

    2011-01-01

    Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing...regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Washington...Need for Information Lifecycle Management .......................................................... 6 3.3 Challenges of Information Lifecycle

  4. Thin graphite bipolar plate with associated gaskets and carbon cloth flow-field for use in an ionomer membrane fuel cell

    DOEpatents

    Marchetti, George A.

    2003-01-03

    The present invention comprises a thin graphite plate with associated gaskets and pieces of carbon cloth that comprise a flow-field. The plate, gaskets and flow-field comprise a "plate and gasket assembly" for use in an ionomer membrane fuel cell, fuel cell stack or battery.

  5. A guide to performance management for the Health Information Manager.

    PubMed

    Leggat, Sandra G

    This paper provides a summary of human resource management practices that have been identified as being associated with better outcomes in performance management. In general, essential practices include transformational leadership and a coherent program of goal setting, performance monitoring and feedback. Some Health Information Managers may feel they require training assistance to develop the necessary skills in the establishment of meaningful work performance goals for staff and the provision of useful and timely feedback. This paper provides useful information to assist Health Information Managers enhance the performance of their staff.

  6. Department of Defense Corporate Information Management

    DTIC Science & Technology

    1991-04-01

    of the Congress on the status and progress of the Corporate Information Management (CIM) initiative. The enclosed report is forwarded in response to... responsibility for implementing the corporate information management program across the Department. This includes the development and implementation of...AD-A251 456//l//lllt//l//l/m//l/.DTIC t ELECTE RjlhSJUNi 1 1992 Department of Defense E Corporate Information Management Prepared by the Assistant

  7. Rationalizing Management Information System Costs.

    ERIC Educational Resources Information Center

    Parden, Robert J.

    This paper examines the proposition that management information systems (MIS) for colleges and universities are not achieving their original objectives of supporting better management decisions by providing more and better information in a more timely manner. As a consequence, the MIS activity should be reduced in scope, and standardized to…

  8. An Extensible Information Grid for Risk Management

    NASA Technical Reports Server (NTRS)

    Maluf, David A.; Bell, David G.

    2003-01-01

    This paper describes recent work on developing an extensible information grid for risk management at NASA - a RISK INFORMATION GRID. This grid is being developed by integrating information grid technology with risk management processes for a variety of risk related applications. To date, RISK GRID applications are being developed for three main NASA processes: risk management - a closed-loop iterative process for explicit risk management, program/project management - a proactive process that includes risk management, and mishap management - a feedback loop for learning from historical risks that escaped other processes. This is enabled through an architecture involving an extensible database, structuring information with XML, schemaless mapping of XML, and secure server-mediated communication using standard protocols.

  9. Inhibition of early biofilm formation by glass-ionomer incorporated with chlorhexidine in vivo: a pilot study.

    PubMed

    Du, X; Huang, X; Huang, C; Frencken, J E; Yang, T

    2012-03-01

    This pilot study investigated the antibiofilm effects of glass-ionomer cements (GICs) and resin-modified glass-ionomer cements (RMGICs) incorporated with chlorhexidine (CHX) in vivo. Experimental GICs and RMGICs containing 2% CHX were obtained by mixing CHX with the powder of GICs (CHXGIC) and RMGICs (CHXRMGIC). Four groups of specimens were prepared in a standardized size. After polishing and sterilization, they were bonded to the buccal surface of the molars in the first and second quadrant of volunteers and left untouched for 4 hours and 24 hours, respectively. The bacterial vitality of plaque was then analysed by confocal laser scanning microscopy (CLSM). The bacterial morphology and biofilm accumulation were determined by scanning electron microscopy (SEM). The pH value of biofilm was assessed by Plaque Indicator Kits. CLSM analysis revealed that bacterial vitality of the biofilm on CHXGIC and CHXRMGIC was significantly lower than that on GIC and RMGIC. SEM analysis indicated that the morphology of bacteria on CHXGIC and CHXRMGIC was irregular. The pH value of biofilm on the experimental materials presented no statistically significant difference. Twenty-four hour bacterial vitality on GICs and RMGICs with CHX are lower in micro-organisms than on conventional GICs and RMGICs. © 2012 Australian Dental Association.

  10. Managing geometric information with a data base management system

    NASA Technical Reports Server (NTRS)

    Dube, R. P.

    1984-01-01

    The strategies for managing computer based geometry are described. The computer model of geometry is the basis for communication, manipulation, and analysis of shape information. The research on integrated programs for aerospace-vehicle design (IPAD) focuses on the use of data base management system (DBMS) technology to manage engineering/manufacturing data. The objectives of IPAD is to develop a computer based engineering complex which automates the storage, management, protection, and retrieval of engineering data. In particular, this facility must manage geometry information as well as associated data. The approach taken on the IPAD project to achieve this objective is discussed. Geometry management in current systems and the approach taken in the early IPAD prototypes are examined.

  11. Educational Management and Information

    ERIC Educational Resources Information Center

    Schaulis, Robert E.; Gripp, Thomas H.

    1974-01-01

    Improvement of information systems to support management and planning in education is dependent on a change to a rational management style. It can be argued that this same prerequisite exists for the return of public confidence and support. (Author)

  12. School Management Information Systems in Primary Schools

    ERIC Educational Resources Information Center

    Demir, Kamile

    2006-01-01

    Developments in information technologies have been impacting upon educational organizations. Principals have been using management information systems to improve the efficiency of administrative services. The aim of this research is to explore principals' perceptions about management information systems and how school management information…

  13. Educational Management Information Systems: Progress and Prospectives.

    ERIC Educational Resources Information Center

    Evans, John A.

    An educational management information system is a network of communication channels, information sources, computer storage and retrieval devices, and processing routines that provide data to educational managers at different levels, places, and times to facilitate decisionmaking. Management information systems should be differentiated from…

  14. Information Seeking in Uncertainty Management Theory: Exposure to Information About Medical Uncertainty and Information-Processing Orientation as Predictors of Uncertainty Management Success.

    PubMed

    Rains, Stephen A; Tukachinsky, Riva

    2015-01-01

    Uncertainty management theory outlines the processes through which individuals cope with health-related uncertainty. Information seeking has been frequently documented as an important uncertainty management strategy. The reported study investigates exposure to specific types of medical information during a search, and one's information-processing orientation as predictors of successful uncertainty management (i.e., a reduction in the discrepancy between the level of uncertainty one feels and the level one desires). A lab study was conducted in which participants were primed to feel more or less certain about skin cancer and then were allowed to search the World Wide Web for skin cancer information. Participants' search behavior was recorded and content analyzed. The results indicate that exposure to two health communication constructs that pervade medical forms of uncertainty (i.e., severity and susceptibility) and information-processing orientation predicted uncertainty management success.

  15. Use of electronic information systems in nursing management.

    PubMed

    Lammintakanen, Johanna; Saranto, Kaija; Kivinen, Tuula

    2010-05-01

    The purpose of this study is to describe nurse managers' perceptions of the use of electronic information systems in their daily work. Several kinds of software are used for administrative and information management purposes in health care organizations, but the issue has been studied less from nurse managers' perspective. The material for this qualitative study was acquired according to the principles of focus group interview. Altogether eight focus groups were held with 48 nurse managers from both primary and specialized health care organizations. The nurse managers were asked in focus groups to describe the use of information systems in their daily work in addition to some other themes. The material was analyzed by inductive content analysis using ATLAS.ti computer program. The main category "pros and cons of using information systems in nursing management" summarized the nurse managers' perceptions of using electronic information systems. The main category consisted of three sub-categories: (1) nurse managers' perceptions of the use of information technology; (2) usability of management information systems; (3) development of personnel competencies and work processes. The nurse managers made several comments on the implementation of immature electronic information systems which caused inefficiencies in working processes. However, they considered electronic information systems to be essential elements of their daily work. Furthermore, the nurse managers' descriptions of the pros and cons of using information systems reflected partly the shortcomings of strategic management and lack of coordination in health care organizations. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  16. Using climate information for fuels management

    USGS Publications Warehouse

    Kolden, Crystal A.; Brown, Timothy J.

    2008-01-01

    Climate has come to the forefront of wildfire discussions in recent years as research contributes to the general understanding of how climate influences fuels availability to burn, the occurrence of severe fire weather conditions and other wildfire parameters. This understanding has crossed over into wildfire management applications through the creation of tools like climate forecasts for wildfire and drought indices, which are now widely used in wildfire suppression and mitigation planning. The overall question is how can climate information help fire managers meet management objectives? Climate underlies weather. For example, a number of days could be generally wet, but that may occur in the context of a two-year overall drought. Knowing the baseline climate is not only critical to preventing escaped prescribed fires, but also how it may affect fire behavior, fire effects and whether or not fire managers will meet their fuels management objectives. Thus, for fire managers to use prescribed and WFU fire safely and effectively, and to minimize the number of escaped fires and conversions to suppression, they need to understand how current climate conditions will impact the use of fire. One example is the need to use prescribed fire under set “burn windows”. Since meteorological conditions vary considerably from year to year for a given day, fire managers will be more successful in utilizing burn windows effectively if they understand those climate thresholds conducive to an increased number of safe burn windows, and are able to predict and take advantage of those burn windows. While climate and wildfire has been studied extensively, climate and fire use has not. The initial goal of this project was to assess how climate impacts prescribed fire use in a more general sense. After a preliminary informal survey in the spring of 2003, we determined that 1) there is insufficient data (less than 10 years) to conduct empirical correlative studies similar to those of

  17. Preparation and evaluation of a novel glass-ionomer cement with antibacterial functions.

    PubMed

    Xie, Dong; Weng, Yiming; Guo, Xia; Zhao, Jun; Gregory, Richard L; Zheng, Cunge

    2011-05-01

    The objective of this study was to use the newly synthesized poly(quaternary ammonium salt) (PQAS)-containing polyacid to formulate the light-curable glass-ionomer cements and study the effect of the PQAS on the compressive strength and antibacterial activity of the formed cements. The functional QAS and their constructed PQAS were synthesized, characterized and formulated into the experimental high-strength cements. Compressive strength (CS) and Streptococcus mutans viability were used to evaluate the mechanical strength and antibacterial activity of the cements. Fuji II LC cement was used as control. The specimens were conditioned in distilled water at 37°C for 24 h prior to testing. The effects of the substitute chain length, loading as well as grafting ratio of the QAS and aging on CS and S. mutans viability were investigated. All the PQAS-containing cements showed a significant antibacterial activity, accompanying with an initial CS reduction. The effects of the chain length, loading and grafting ratio of the QAS were significant. Increasing chain length, loading, grafting ratio significantly enhanced antibacterial activity but reduced the initial CS. Under the same substitute chain length, the cements containing QAS bromide were found to be more antibacterial than those containing QAS chloride although the CS values of the cements were not statistically different from each other, suggesting that we can use QAS bromide directly without converting bromide to chloride. The experimental cement showed less CS reduction and higher antibacterial activity than Fuji II LC. The long-term aging study suggests that the cements may have a long-lasting antibacterial function. This study developed a novel antibacterial glass-ionomer cement. Within the limitations of this study, it appears that the experimental cement is a clinically attractive dental restorative due to its high mechanical strength and antibacterial function. Published by Elsevier Ltd.

  18. Information Resource Management for Industrial Information Officers.

    ERIC Educational Resources Information Center

    Dosa, Marta

    This paper argues that the function of educational programs is to convey a sense of reality and an understanding of the open-endedness of information needs and situations; only such a reality orientation can instill the necessary flexibility in information professionals for effectively managing change. There is a growing consensus among…

  19. Disabilities Information Flow: A Disabilities Information Management System

    ERIC Educational Resources Information Center

    Ling, Bin; Allison, Colin; Nicholl, J. Ross; Moodley, Luke; Roberts, Dave

    2006-01-01

    The Disabilities Information Flow (DIF) project at the University of St Andrews has sought to provide a means of efficiently managing all student disabilities information within the institution and provide appropriate role-based service interfaces for all staff who need to routinely interact with this information. This paper describes the software…

  20. Biological and mechanical properties of an experimental glass-ionomer cement modified by partial replacement of CaO with MgO or ZnO.

    PubMed

    Kim, Dong-Ae; Abo-Mosallam, Hany; Lee, Hye-Young; Lee, Jung-Hwan; Kim, Hae-Won; Lee, Hae-Hyoung

    2015-01-01

    Some weaknesses of conventional glass ionomer cement (GIC) as dental materials, for instance the lack of bioactive potential and poor mechanical properties, remain unsolved.Objective The purpose of this study was to investigate the effects of the partial replacement of CaO with MgO or ZnO on the mechanical and biological properties of the experimental glass ionomer cements.Material and Methods Calcium fluoro-alumino-silicate glass was prepared for an experimental glass ionomer cement by melt quenching technique. The glass composition was modified by partial replacement (10 mol%) of CaO with MgO or ZnO. Net setting time, compressive and flexural properties, and in vitrorat dental pulp stem cells (rDPSCs) viability were examined for the prepared GICs and compared to a commercial GIC.Results The experimental GICs set more slowly than the commercial product, but their extended setting times are still within the maximum limit (8 min) specified in ISO 9917-1. Compressive strength of the experimental GIC was not increased by the partial substitution of CaO with either MgO or ZnO, but was comparable to the commercial control. For flexural properties, although there was no significance between the base and the modified glass, all prepared GICs marked a statistically higher flexural strength (p<0.05) and comparable modulus to control. The modified cements showed increased cell viability for rDPSCs.Conclusions The experimental GICs modified with MgO or ZnO can be considered bioactive dental materials.

  1. Insider Threat and Information Security Management

    NASA Astrophysics Data System (ADS)

    Coles-Kemp, Lizzie; Theoharidou, Marianthi

    The notion of insider has multiple facets. An organization needs to identify which ones to respond to. The selection, implementetion and maintenance of information security countermeasures requires a complex combination of organisational policies, functions and processes, which form Information Security Management. This chapter examines the role of current information security management practices in addressing the insider threat. Most approaches focus on frameworks for regulating insider behaviour and do not allow for the various cultural responses to the regulatory and compliance framework. Such responses are not only determined by enforcement of policies and awareness programs, but also by various psychological and organisational factors at an individual or group level. Crime theories offer techniques that focus on such cultural responses and can be used to enhance the information security management design. The chapter examines the applicability of several crime theories and concludes that they can contribute in providing additional controls and redesign of information security management processes better suited to responding to the insider threat.

  2. Hospital managers need management information systems.

    PubMed

    Davis, S; Freeman, J R

    1976-01-01

    A new hospital director seeking to bring his institution to the brink of solvency found himself with ten pounds of data but no "information"--at least, not the kind of information he could use as a basis for management decisions. What he needed was a system that would not only present data, but the meaning of the data. Such a system is the integrated MIS.

  3. Computer Aided Management for Information Processing Projects.

    ERIC Educational Resources Information Center

    Akman, Ibrahim; Kocamustafaogullari, Kemal

    1995-01-01

    Outlines the nature of information processing projects and discusses some project management programming packages. Describes an in-house interface program developed to utilize a selected project management package (TIMELINE) by using Oracle Data Base Management System tools and Pascal programming language for the management of information system…

  4. N-vinylpyrrolidone modified glass-ionomer resins for improved dental restoratives

    NASA Astrophysics Data System (ADS)

    Xie, Dong

    The studies described in this dissertation focus on improvement of mechanical properties of current glass-ionomer cements. Thermal properties and microstructures of the cements were correlated with their mechanical strengths. The first study evaluated mechanical properties of selected commercial glass-ionomer cements and examined their microstructures. The results showed that resin-modified glass-ionomer cements (RM GICs) exhibited much higher flexural (FS) and diametral tensile strengths (DTS), compared to conventional GICs (C GICs). In addition, they exhibited comparable compressive strength (CS), relatively low microhardness and less wear resistance than C GICs. The C GICs exhibited brittle behavior, whereas the RM GICs underwent substantial plastic deformation in compression. The mechanical properties of the GICs were closely related to their microstructures. Factors such as the density of the microstructure, the integrity of the interface between the glass particles and polymer matrix, particle size and the number and size of voids have important roles in determining the mechanical properties. The second study evaluated thermal properties of these GICs. The results showed that the RM GICs exhibited higher thermal transition temperatures than those of the C GICs, thermal expansion coefficients of these cements were close to those of human teeth, and the indentation creep of the RM GICs were higher than the C GICs. The third study explored and evaluated the effect of a water-soluble monomer, N-vinylpyrrolidone (NVP), on the performance of current C GICs, indicating a significant improvement in both mechanical and working properties. The fourth study demonstrated the process of determining the optimal molar ratio of the NVP-containing copolymers, using design of experiment. The results showed that the optimal molar ratio for these copolymers was 7:1:3 for poly(acrylic acid-co-itaconic acid-co-N-vinylpyrrolidone), based on the FS test. The molar ratio of 8:2:1 (AA

  5. Proteomics, metabolomics, and ionomics perspectives of salinity tolerance in halophytes

    PubMed Central

    Kumari, Asha; Das, Paromita; Parida, Asish Kumar; Agarwal, Pradeep K.

    2015-01-01

    Halophytes are plants which naturally survive in saline environment. They account for ∼1% of the total flora of the world. They include both dicots and monocots and are distributed mainly in arid, semi-arid inlands and saline wet lands along the tropical and sub-tropical coasts. Salinity tolerance in halophytes depends on a set of ecological and physiological characteristics that allow them to grow and flourish in high saline conditions. The ability of halophytes to tolerate high salt is determined by the effective coordination between various physiological processes, metabolic pathways and protein or gene networks responsible for delivering salinity tolerance. The salinity responsive proteins belong to diverse functional classes such as photosynthesis, redox homeostasis; stress/defense, carbohydrate and energy metabolism, protein metabolism, signal transduction and membrane transport. The important metabolites which are involved in salt tolerance of halophytes are proline and proline analog (4-hydroxy-N-methyl proline), glycine betaine, pinitol, myo-inositol, mannitol, sorbitol, O-methylmucoinositol, and polyamines. In halophytes, the synthesis of specific proteins and osmotically active metabolites control ion and water flux and support scavenging of oxygen radicals under salt stress condition. The present review summarizes the salt tolerance mechanisms of halophytes by elucidating the recent studies that have focused on proteomic, metabolomic, and ionomic aspects of various halophytes in response to salinity. By integrating the information from halophytes and its comparison with glycophytes could give an overview of salt tolerance mechanisms in halophytes, thus laying down the pavement for development of salt tolerant crop plants through genetic modification and effective breeding strategies. PMID:26284080

  6. The Air Program Information Management System (APIMS)

    DTIC Science & Technology

    2011-11-02

    Technology November 2, 2011 The Air Program Information Management System (APIMS) Frank Castaneda, III, P.E. APIMS Program Manager AFCEE/TDNQ APIMS...NOV 2011 2. REPORT TYPE 3. DATES COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE The Air Program Information Management System (APIMS... Information   Management   System : Sustainability of  Enterprise air quality management system • Aspects and Impacts to Process • Auditing and Measurement

  7. Influence of Porous Spherical-Shaped Hydroxyapatite on Mechanical Strength and Bioactive Function of Conventional Glass Ionomer Cement.

    PubMed

    Chiu, Szu-Yu; Shinonaga, Yukari; Abe, Yoko; Harada, Kyoko; Arita, Kenji

    2017-01-03

    Glass-ionomer-cement (GIC) is helpful in Minimal Intervention Dentistry because it releases fluoride ions and is highly biocompatible. The aim of this study is to investigate the mechanisms by which hydroxyapatite (HAp) improves the mechanical strength and bioactive functioning of GIC when these materials are combined to make apatite ionomer cement (AIC). A conventional GIC powder was mixed with porous, spherical-HAp particles (HApS), crystalline HAp (HAp200) or one of two types of cellulose. The micro-compressive strengths of the additive particles were measured, and various specimens were evaluated with regard to their compressive strengths (CS), fluoride release concentrations (fluoride electrode) and multi-element release concentrations. The AIC was found to release higher concentrations of fluoride (1.2 times) and strontium ions (1.5 times) compared to the control GIC. It was detected the more release of calcium originated from HApS than HAp200 in AIC. The CS of the AIC incorporating an optimum level of HAp was also significantly higher than that of the GIC. These results suggest that adding HAp can increase the release concentration of ions required for remineralization while maintaining the CS of the GIC. This effect does not result from a physical phenomenon, but rather from chemical reactions between the HAp and polyacrylic acid of GIC.

  8. Zinc Detoxification Is Required for Full Virulence and Modification of the Host Leaf Ionome by Xylella fastidiosa.

    PubMed

    Navarrete, Fernando; De La Fuente, Leonardo

    2015-04-01

    Zinc (Zn) is an essential element for all forms of life because it is a structural or catalytic cofactor of many proteins, but it can have toxic effects at high concentrations; thus, microorganisms must tightly regulate its levels. Here, we evaluated the role of Zn homeostasis proteins in the virulence of the xylem-limited bacterium Xylella fastidiosa, causal agent of Pierce's disease of grapevine, among other diseases. Two mutants of X. fastidiosa 'Temecula' affected in genes which regulate Zn homeostasis (zur) and Zn detoxification (czcD) were constructed. Both knockouts showed increased sensitivity to Zn at physiologically relevant concentrations and increased intracellular accumulation of this metal compared with the wild type. Increased Zn sensitivity was correlated with decreased growth in grapevine xylem sap, reduced twitching motility, and downregulation of exopolysaccharide biosynthetic genes. Tobacco plants inoculated with either knockout mutant showed reduced foliar symptoms and a much reduced (czcD) or absent (zur) modification of the leaf ionome (i.e., the mineral nutrient and trace element composition), as well as reduced bacterial populations. The results show that detoxification of Zn is crucial for the virulence of X. fastidiosa and verifies our previous findings that modification of the host leaf ionome correlates with bacterial virulence.

  9. 76 FR 66327 - Iron Mountain Information Management, Inc., Corporate Service Group, Information Technology (IT...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-26

    ... Management, Inc., Corporate Service Group, Information Technology (IT) Division, Including On-Site Leased... Information Management, Inc., Corporate Service Group, Information Technology (IT) Division, including on-site... location of Iron Mountain Information Management, Inc., Corporate Service Group, Information Technology (IT...

  10. On Management "Myth"-Information Systems.

    ERIC Educational Resources Information Center

    Mitroff, Ian I.; And Others

    Management Myth-Information Systems (MMIS) are information systems which present information to a decision maker by means of stories. In MMIS a scientific datum by itself is not information, but is information if and only if it is tied to an appropriate story or myth that has meaning to the individual who needs the information, the organization in…

  11. Effect of Different Concentrations of Chlorhexidine in Glass-ionomer Cements on In Vivo Biocompatibility.

    PubMed

    Lacerda-Santos, Rogério; Sampaio, Gêisa Aiane de Morais; Moura, Mirella de Fátima Liberato; Carvalho, Fabiola Galbiatti de; Santos, Antonielson Dos; Pithon, Matheus Melo; Alves, Polliana Muniz

    To examine whether a difference exists between the in vivo biocompatibility of glass-ionomer cements (GICs) containing chlorhexidine (CHX) in different concentrations. Eighty-four male Wistar rats were distributed into 7 groups (n = 12) and received subcutaneous implants of small tubes containing different materials, as follows: Ketac control (K), Ketac-CHX 10% (K10), Ketac-CHX 18% (K18), Resilience control (R), Resilience-CHX 10% (R10), Resilience-CHX 18% (R18), Control (polyethylene). The animals were then sacrificed on post-insertion days 7, 15 and 30, and tissues were examined under an optical microscope for inflammatory infiltrate, edema, necrosis, granulation tissue, multinucleated giant cells, and collagen fibers. The results were statistically analyzed using Kruskal-Wallis and Dunn's tests (p < 0.05). Groups K18 and R18 showed larger areas of intense inflammatory infiltrate, with significant differences between group C and groups K18 and R18 (p = 0.007) at 7 days, and between groups C and K18 (p = 0.017) at 15 days. In terms of tissue repair, groups K18 and R18 demonstrated a lower quantity of collagen fibers with significant differences from group C (p = 0.019) at 7 days, and between group K18 and group C (p = 0.021) at 15 days. The 18% concentration of CHX was shown to have a toxic effect. The 10% concentration of CHX was shown to be suitable for tissue contact. The addition of CHX to the glass-ionomer cements is a highly promising method for obtaining of an antibacterial GIC for use in clinical practice.

  12. Entrepreneurial Librarianship: The Key to Effective Information Services Management. Information Services Management Series.

    ERIC Educational Resources Information Center

    St. Clair, Guy

    The need to approach library management from an entrepreneurial business perspective is vital, whether the information facility is in a corporate, academic, public or school setting. Although librarianship is not a business, library management must be driven by the same characteristics-- responsibility, performance, and control--as any other…

  13. Information management and information technologies: keys to professional and business success.

    PubMed

    Otten, K W

    1984-01-01

    Personal computers, spreadsheets, decision support software, electronic mail and video disks are just a few of the innovations of information technology which attract the attention of information professionals and managers alike: they are all concerned with the rapidly changing face of information technology and how to cope with a changing competitive environment, personally, and for the benefit of their companies. This paper is the first in a monthly series which tries to illuminate some of the factors and changes which shape our future as professionals and managers. In so doing, it guides and motivates the reader to become "information literate," a prerequisite for personal advancement in an information-based economy. This first paper outlines the relationship between technological innovations, use of information tools and information management and what to consider in order to benefit from the information revolution. It explains the risks of becoming professionally obsolete and alerts the reader to get personally involved to remain or become "information and computer literate."

  14. PIMS-Universal Payload Information Management

    NASA Technical Reports Server (NTRS)

    Elmore, Ralph; McNair, Ann R. (Technical Monitor)

    2002-01-01

    As the overall manager and integrator of International Space Station (ISS) science payloads and experiments, the Payload Operations Integration Center (POIC) at Marshall Space Flight Center had a critical need to provide an information management system for exchange and management of ISS payload files as well as to coordinate ISS payload related operational changes. The POIC's information management system has a fundamental requirement to provide secure operational access not only to users physically located at the POIC, but also to provide collaborative access to remote experimenters and International Partners. The Payload Information Management System (PIMS) is a ground based electronic document configuration management and workflow system that was built to service that need. Functionally, PIMS provides the following document management related capabilities: 1. File access control, storage and retrieval from a central repository vault. 2. Collect supplemental data about files in the vault. 3. File exchange with a PMS GUI client, or any FTP connection. 4. Files placement into an FTP accessible dropbox for pickup by interfacing facilities, included files transmitted for spacecraft uplink. 5. Transmission of email messages to users notifying them of new version availability. 6. Polling of intermediate facility dropboxes for files that will automatically be processed by PIMS. 7. Provide an API that allows other POIC applications to access PIMS information. Functionally, PIMS provides the following Change Request processing capabilities: 1. Ability to create, view, manipulate, and query information about Operations Change Requests (OCRs). 2. Provides an adaptable workflow approval of OCRs with routing through developers, facility leads, POIC leads, reviewers, and implementers. Email messages can be sent to users either involving them in the workflow process or simply notifying them of OCR approval progress. All PIMS document management and OCR workflow controls are

  15. Two-year survival rates of proximal atraumatic restorative treatment restorations in relation to glass ionomer cements and Postrestoration meals consumed.

    PubMed

    Kemoli, Arthur Musakulu; Opinya, Gladys N; van Amerongen, Willem Evert; Mwalili, Samuel M

    2011-01-01

    The purpose of this study was to investigate the influence of 3 glass ionomer cement (GIC) brands and the postrestoration meal consumed on the survival rate of proximal atraumatic restorative treatment (ART) restorations. A total of 804 proximal restorations were placed in primary molars by trained operators and assistants using 3 GIC brands. The materials' mixing/placement times, the room temperature and the postrestoration meal consumed by the subjects were documented. The restorations were evaluated soon after placement and after 2 years by trained and calibrated evaluators. After 2 years, approximately 31% of the restorations had survived. There were no statistically significant differences in the survival rate of the restorations in relation to the GIC brands. The postrestoration meal consumed, which was of "hard consistency," was associated with significantly lower survival rate of the restorations. The survival rate of the proximal restorations was not significantly affected by the glass ionomer cement brands used, but was significantly influenced by the consistency of the next meal consumed by each child.

  16. Training for Information Management in a Company.

    ERIC Educational Resources Information Center

    Karivalo, Merja

    1989-01-01

    Argues that information resource management is an established philosophy that needs to be linked to human resources management and strategic planning in industrial companies. A training program for information management is presented, including training objectives, participants, contents, and structure. (CLB)

  17. Phoenix: SOA based information management services

    NASA Astrophysics Data System (ADS)

    Grant, Rob; Combs, Vaughn; Hanna, Jim; Lipa, Brian; Reilly, Jim

    2009-05-01

    The Air Force Research Laboratory (AFRL) has developed a reference set of Information Management (IM) Services that will provide an essential piece of the envisioned final Net-Centric IM solution for the Department of Defense (DoD). These IM Services will provide mission critical functionality to enable seamless interoperability between existing and future DoD systems and services while maintaining a highly available IM capability across the wide spectrum of differing scalability and performance requirements. AFRL designed this set of IM Services for integration with other DoD and commercial SOA environments. The services developed will provide capabilities for information submission, information brokering and discovery, repository, query, type management, dissemination, session management, authorization, service brokering and event notification. In addition, the IM services support common information models that facilitate the management and dissemination of information consistent with client needs and established policy. The services support flexible and extensible definitions of session, service, and channel contexts that enable the application of Quality of Service (QoS) and security policies at many levels within the SOA.

  18. Management Information System Project.

    ERIC Educational Resources Information Center

    Foley, Walter J.; Harr, Gordon G.

    The Management Information System (MIS) described in this report represents a plan to utilize modern management techniques to facilitate the goal of a learner-responsive school system. The MIS component is being developed to meet the need for the coordination of the resources of staff, facilities, and time with the long range planning and…

  19. Strategic Planning for Information Resources Management.

    ERIC Educational Resources Information Center

    Penrod, James; Dolence, Michael

    1987-01-01

    In 1985, California State University/Los Angeles changed the management of its information resources by hiring a vice president for information resources management; reorganizing existing units into an IRM organization; engaging in a detailed, integrated, participative strategic planning process; and initiating several significant projects.…

  20. Internet and Electronic Information Management

    DTIC Science & Technology

    2003-04-01

    technologies ) and information markets (buying and selling information ), and the competitors’ success or failures. Such factors are beyond the control of... technology , and 1-19 market pressures. They have to cooperate with other entities within their organizations to develop more innovative information ...UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP014048 TITLE: Internet and Electronic Information Management

  1. Information therapy: The strategic role of prescribed information in disease self-management.

    PubMed

    Mettler, Molly; Kemper, Donald W

    2006-01-01

    Imagine this: evidence-based medical information specifically written for and prescribed to a patient with chronic illness, targeted to that patient's specific "moment in care" and designed to help that patient manage his or her illness. Imagine "information therapy" built into every clinical encounter that a patient has with a physician or other health care service. Information therapy is defined as the timely prescription and availability of evidence-based health information to meet individuals' specific needs and support sound decision making. Information therapy is a new disease management tool that provides cost-effective disease management support to a much larger portion of the chronically ill population than is generally reached. This paper is a practical presentation of information therapy, its role in predictive modeling and disease self-management, and its potential for improving the outcomes of chronic care.

  2. 76 FR 76917 - Homeless Management Information Systems Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-09

    ...-P-01] Homeless Management Information Systems Requirements AGENCY: Office of the Assistant Secretary... for the establishment of regulations for Homeless Management Information Systems (HMIS), which are the... community development, Homeless, Information technology system, Management system, Nonprofit organizations...

  3. Performance Information Management System (PIMS) Communication

    DTIC Science & Technology

    1993-12-31

    34AD-A284 851 AD MIPR NO. MIPR 92MM2501 TITLE: Performance Information Management System (PIMS) Communication PRINCIPAL INVESTIGATOR: Kathryn P...93 . . ..- F •nal,. 12/1/91 - 12/31/93- ...... . ..... PIMS-Performance Information Management System Communications 92MM2501 Kathryn P. Winter Navy

  4. RIMS: Resource Information Management System

    NASA Technical Reports Server (NTRS)

    Symes, J.

    1983-01-01

    An overview is given of the capabilities and functions of the resource management system (RIMS). It is a simple interactive DMS tool which allows users to build, modify, and maintain data management applications. The RIMS minimizes programmer support required to develop/maintain small data base applications. The RIMS also assists in bringing the United Information Services (UIS) budget system work inhouse. Information is also given on the relationship between the RIMS and the user community.

  5. The importance of management information systems in a managed care environment.

    PubMed

    Porro, M R; Brill, K R

    1995-06-01

    Keys to successful information systems for home care providers are planning and control. With managed care's emphasis on data, agencies need to have information systems that can handle the demands managed care puts on agencies today--planning before hurrying to install a system will ensure control as the managed care contracts add up.

  6. 20 CFR 633.311 - Management information systems.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Management information systems. 633.311... AND SEASONAL FARMWORKER PROGRAMS Program Design and Administrative Procedures § 633.311 Management information systems. All grantees shall establish and maintain a program and financial management system which...

  7. 20 CFR 633.311 - Management information systems.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Management information systems. 633.311... AND SEASONAL FARMWORKER PROGRAMS Program Design and Administrative Procedures § 633.311 Management information systems. All grantees shall establish and maintain a program and financial management system which...

  8. 20 CFR 633.311 - Management information systems.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 3 2012-04-01 2012-04-01 false Management information systems. 633.311... AND SEASONAL FARMWORKER PROGRAMS Program Design and Administrative Procedures § 633.311 Management information systems. All grantees shall establish and maintain a program and financial management system which...

  9. Information Management. Myths and Realities.

    ERIC Educational Resources Information Center

    Kerka, Sandra

    A number of misconceptions or "myths" about information management have arisen since the beginning of the Information Age. One misconception is that the problem of information overload stems from too much information. In reality, the greater problem may be an explosion of noninformation. Many people believe that they must try to stay on…

  10. An Information-Processing Model of Crisis Management.

    ERIC Educational Resources Information Center

    Egelhoff, William G.; Sen, Falguni

    1992-01-01

    Develops a contingency model for managing a variety of corporate crises. Views crisis management as an information-processing situation and organizations that must cope with crisis as information-processing systems. Attempts to fit appropriate information-processing mechanisms to different categories of crises. (PRA)

  11. Internet and Electronic Information Management

    DTIC Science & Technology

    2004-12-01

    centers to form consortia and share electronic information sources. Although traditional resource sharing arrangements encouraged competition rather...outside world, through public relations and through marketing information products or services, to its own competitive advantage (Davenport 1997: 193-217... electronic information sources are a challenge for electronic information managers. Libraries and information centers are no longer “the only game in town

  12. Technical Literature Review Concerning Management Information Systems.

    DTIC Science & Technology

    interrelationships of the many aspects of management information systems (MIS); that is, with how analysis, design, operation, evaluation, and user considerations affect management information systems . (Author)

  13. Brave New World: The Information Management Revolution.

    ERIC Educational Resources Information Center

    McIntyre, Jim

    1995-01-01

    Indiana University and the University of Delaware have begun to expand the notion of financial information management by the innovative use of computer and Internet applications. Widespread access to institutional information has advantages and disadvantages. At both institutions, information managers addressed administrative resistance but…

  14. Knowledge Management and Global Information Dissemination

    ERIC Educational Resources Information Center

    Umunadi, Ejiwoke Kennedy

    2014-01-01

    The paper looked at knowledge management and global information dissemination. Knowledge is a very powerful tool for survival, growth and development. It can be seen as the information, understanding and skills that you gain through education or experience. The paper was addressed under the following sub-headings: Knowledge management knowledge…

  15. Performance Information Management System (PIMS) Communication

    DTIC Science & Technology

    1992-10-15

    AD-A267 040 AD 14IPR NO: 92M•2501 TITLE: PERFORMANCE INFORMATION MANAGEMENT SYSTEM (PIMS) COMMUNICATION V G ,c¶• PRINCIPAL INVESTIGATOR: Kathryn P...Performance Information Management System (PIMS) MIPR No. Communication 92MM2501 6. AUTHOR(S) Kathryn P. Winter 7. PERFORMING ORGANIZATION NAME(S) AND

  16. Mosquito Information Management Project (MIMP): Application of a Computerized General Purpose Information Management System (SELGEM) to Medically Important Arthropods (Diptera: culicidae).

    DTIC Science & Technology

    1984-08-01

    4 MOSQUITO INFORMATION MANAGEMENT PROJECT (MIMP): *APPLICATION OF A COMPUTERIZED GENERAL PURPOSE I INFORMATION MANAGEMENT SYSTEM (SELGEM) TO...1983 to August 1984 INFORMATION MANAGEMENT SYSTEM (SELGEM) TO MEDI- 6 EFRIGOG EOTNME * CALLY IMPORTANT ARTHROPODS (DIPTERA: CULICIDAE) .v PEnRMN OG

  17. Real-time information management environment (RIME)

    NASA Astrophysics Data System (ADS)

    DeCleene, Brian T.; Griffin, Sean; Matchett, Garry; Niejadlik, Richard

    2000-08-01

    Whereas data mining and exploitation improve the quality and quantity of information available to the user, there remains a mission requirement to assist the end-user in managing the access to this information and ensuring that the appropriate information is delivered to the right user in time to make decisions and take action. This paper discusses TASC's federated architecture to next- generation information management, contrasts the approach against emerging technologies, and quantifies the performance gains. This architecture and implementation, known as Real-time Information Management Environment (RIME), is based on two key concepts: information utility and content-based channelization. The introduction of utility allows users to express the importance and delivery requirements of their information needs in the context of their mission. Rather than competing for resources on a first-come/first-served basis, the infrastructure employs these utility functions to dynamically react to unanticipated loading by optimizing the delivered information utility. Furthermore, commander's resource policies shape these functions to ensure that resources are allocated according to military doctrine. Using information about the desired content, channelization identifies opportunities to aggregate users onto shared channels reducing redundant transmissions. Hence, channelization increases the information throughput of the system and balances sender/receiver processing load.

  18. 46 CFR 16.500 - Management Information System requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Management Information System requirements. 16.500 Section 16.500 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN CHEMICAL TESTING Management Information System § 16.500 Management Information System requirements. (a...

  19. 46 CFR 16.500 - Management Information System requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Management Information System requirements. 16.500 Section 16.500 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN CHEMICAL TESTING Management Information System § 16.500 Management Information System requirements. (a...

  20. 46 CFR 16.500 - Management Information System requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Management Information System requirements. 16.500 Section 16.500 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN CHEMICAL TESTING Management Information System § 16.500 Management Information System requirements. (a...

  1. 46 CFR 16.500 - Management Information System requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Management Information System requirements. 16.500 Section 16.500 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN CHEMICAL TESTING Management Information System § 16.500 Management Information System requirements. (a...

  2. 46 CFR 16.500 - Management Information System requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Management Information System requirements. 16.500 Section 16.500 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN CHEMICAL TESTING Management Information System § 16.500 Management Information System requirements. (a...

  3. Management Information Systems.

    ERIC Educational Resources Information Center

    Finlayson, Jean, Ed.

    1989-01-01

    This collection of papers addresses key questions facing college managers and others choosing, introducing, and living with big, complex computer-based systems. "What Use the User Requirement?" (Tony Coles) stresses the importance of an information strategy driven by corporate objectives, not technology. "Process of Selecting a…

  4. Knowledge and information management for integrated water resource management

    USDA-ARS?s Scientific Manuscript database

    Watershed information systems that integrate data and analytical tools are critical enabling technologies to support Integrated Water Resource Management (IWRM) by converting data into information, and information into knowledge. Many factors bring people to the table to participate in an IWRM fra...

  5. Preparation and evaluation of a novel star-shaped polyacid-constructed dental glass-ionomer system.

    PubMed

    Howard, Leah; Weng, Yiming; Xie, Dong

    2014-06-01

    The objective of this study was to synthesize and characterize novel star-shaped poly(acrylic acid-co-itaconic acid)s via chain-transfer radical polymerization technique, use these polyacids to formulate the resin-modified glass-ionomer cements, and evaluate the mechanical strengths of the formed cements The star-shaped poly(acrylic acid-co-itaconic acid)s were synthesized via a chain-transfer radical polymerization reaction using a newly synthesized star-shaped chain-transfer agent. The effects of MW, GM-tethering ratio, P/L ratio and aging on the compressive properties of the formed experimental cements were studied. Compressive, diametral tensile as well as flexural strengths were evaluated and compared to those of Fuji II and Fuji II LC cements. The star-shaped polyacids showed significantly lower viscosities in water as compared to their linear counterparts. The cements formulated with these novel polyacids showed significantly improved mechanical strengths i.e., 49% in yield strength, 41% in modulus, 25% in CS, 20% in DTS and 36% in FS, higher than commercial Fuji II LC. After aging in water for 30 days, the compressive strengths of the experimental cements were significantly changed with an increase of 29% in YS, 19% in modulus as well as 23% in CS and a decrease of 5% in toughness, indicating that aging in water enhances the salt-bridge formation and increases brittleness. A novel light-cured glass-ionomer cement system composed of the star-shaped poly(carboxylic acid)s has been developed via a cost-effective and time-efficient chain-transfer radical polymerization. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  6. Clipped Random Wave Morphologies and the Analysis of the SAXS of an Ionomer Formed by Copolymerization of Tetrafluoroethylene and CF[subscript 2]=CFO(CF[subscript 2])[subscript 4]SO[subscript 3]H

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Aieta, Niccolo V.; Stanis, Ronald J.; Horan, James L.

    Using SAXS data, the microstructure of the ionomer formed by copolymerization of tetrafluoroethylene and CF{sub 2}=CFO(CF{sub 2}){sub 4}SO{sub 3}H films has been approached by two methods: a numerical method (the unified fit approach) utilizing a simple model of spherical scattering objects to determine the radius of gyration of different scattering features of the ionomer films and by a graphical method, the clipped random wave approach (CRW), using the scattering data and a porosity parameter to generate a random wave which is clipped to produce a real-space image of the microstructure. We studied films with EW of 733, 825, 900, andmore » 1082 in both the as-cast and annealed 'dry' and boiled 'wet' states. The results of the two data analysis techniques are in good size agreement with each other. In addition, the CRW model show striking similarities to the structure proposed in a recent dissipative particle dynamic models. This has been the first time to our knowledge that the CRW technique has been applied to a PFSA type ionomer.« less

  7. 76 FR 28034 - Labor-Management Relations Information Collection Requests

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-13

    ... FEDERAL MEDIATION AND CONCILIATION SERVICE Labor-Management Relations Information Collection... of Subjects Labor-management relations, employee management relations, and Information collection... opportunity to comment on the following information collection requests. The information collection requests...

  8. The dissolution mechanisms of silicate and glass-ionomer dental cements.

    PubMed

    Kuhn, A T; Wilson, A D

    1985-11-01

    The mechanism of dissolution of two dental cements of the acid-base setting types (silicate and glass-ionomer) is considered. Dissolution is incongruent, probably because most of the leached species can derive both from the matrix (polysalt gel) and the partly reacted glass particles. The release occurs by means of three discrete mechanisms, surface wash-off, diffusion through pores and cracks or diffusion through the bulk. Such behaviour is shown to be capable of being modelled with extremely high goodness-of-fit values, using equations such as y = const + at1/2 + bt. Analogies with research from the fields of geochemistry and nuclear fuel storage are made and these systems obey similar relationships. The dental cement systems differ, however, in that their dissolution is to some extent reversible. This is explained in terms of formation of insoluble complexes, either by reaction of the constituent ions, or by replacement of OH-, for example, with F-.

  9. Quality Management and Information Brokerage.

    ERIC Educational Resources Information Center

    van Halm, Johan

    1995-01-01

    To compete effectively, information brokers need to adopt management and marketing tools; Total Quality Management can upgrade an organization's performance by using customer feedback of its services. SERVQUAL identifies gaps in service by assessing quality expectations versus quality experiences. (AEF)

  10. A long term study of fluoride release from metal-containing conventional and resin-modified glass-ionomer cements.

    PubMed

    Williams, J A; Billington, R W; Pearson, G J

    2001-01-01

    The objective of this study was to determine long term release of fluoride from a resin-modified glass-ionomer cement (RMGIC) (Fuji II LC (FLC)) compared with that from two conventional acid-base setting cements (HiDense (HD) and KetacSilver (KS)) marketed for similar restorative purposes. Fluoride release from discs of cement immersed in water or artificial saliva was measured for 2.7 years using an ion selective electrode technique. The RMGIC was affected by water if immersed immediately after setting. This is similar to conventional acid-base cements and the experimental method was designed to allow for this. Over the 2.7-year period, the RMGIC and HD released similar amounts of fluoride into both water and artificial saliva. In water, the RMGIC released the most fluoride, while in artificial saliva the highest release was from HD. KS released the least amount of fluoride in both immersing liquids. In artificial saliva, release was reduced to 17-25% of that found in water, with the RMGIC showing the greatest reduction. Both acid-base cured cements showed changes in colour over the 2.7-year span, while the colour of the RMGIC was stable. It was concluded that the RMGIC released equivalent or greater amounts of fluoride than the two acid-base cure glass-ionomers over a period of 2.7 years.

  11. Influence of Porous Spherical-Shaped Hydroxyapatite on Mechanical Strength and Bioactive Function of Conventional Glass Ionomer Cement

    PubMed Central

    Chiu, Szu-Yu; Shinonaga, Yukari; Abe, Yoko; Harada, Kyoko; Arita, Kenji

    2017-01-01

    Glass-ionomer-cement (GIC) is helpful in Minimal Intervention Dentistry because it releases fluoride ions and is highly biocompatible. The aim of this study is to investigate the mechanisms by which hydroxyapatite (HAp) improves the mechanical strength and bioactive functioning of GIC when these materials are combined to make apatite ionomer cement (AIC). A conventional GIC powder was mixed with porous, spherical-HAp particles (HApS), crystalline HAp (HAp200) or one of two types of cellulose. The micro-compressive strengths of the additive particles were measured, and various specimens were evaluated with regard to their compressive strengths (CS), fluoride release concentrations (fluoride electrode) and multi-element release concentrations. The AIC was found to release higher concentrations of fluoride (1.2 times) and strontium ions (1.5 times) compared to the control GIC. It was detected the more release of calcium originated from HApS than HAp200 in AIC. The CS of the AIC incorporating an optimum level of HAp was also significantly higher than that of the GIC. These results suggest that adding HAp can increase the release concentration of ions required for remineralization while maintaining the CS of the GIC. This effect does not result from a physical phenomenon, but rather from chemical reactions between the HAp and polyacrylic acid of GIC. PMID:28772386

  12. Nanoclay-Reinforced Glass-Ionomer Cements: In Vitro Wear Evaluation and Comparison by Two Wear-Test Methods

    PubMed Central

    Fareed, Muhammad A.; Stamboulis, Artemis

    2017-01-01

    Glass ionomer cement (GIC) represents a major transformation in restorative dentistry. Wear of dental restoratives is a common phenomenon and the determination of the wear resistance of direct-restorative materials is a challenging task. The aim of this paper was to evaluate the wear resistance of novel glass ionomer cement by two wear-test methods and to compare the two wear methods.The wear resistance of a conventional glass ionomer cement (HiFi Advanced Health Care Kent, UK) and cements modified by including various percentages of nanoclays (1, 2 and 4 wt %) was measured by a reciprocating wear test (ball-on-flat) and Oregon Health and Sciences University’s (OHSU) wear simulator. The OHSU wear simulation subjected the cement specimens to three wear mechanisms, namely abrasion, three-body abrasion and attrition using a steatite antagonist. The abrasion wear resulted in material loss from GIC specimen as the steatite antagonist forced through the exposed glass particles when it travelled along the sliding path.The hardness of specimens was measured by the Vickers hardness test. The results of reciprocation wear test showed that HiFi-1 resulted in the lowest wear volume 4.90 (0.60) mm3 (p < 0.05), but there was no significant difference (p > 0.05) in the wear volume in comparison to HiFi, HiFi-2 and HiFi-4. Similarly, the results of OHSU wear simulator showed that the total wear volume of HiFi-4 1.49 (0.24) was higher than HiFi-1 and HiFi-2. However, no significant difference (p > 0.05) was found in the OHSU total wear volume in GICs after nanoclay incorporation. The Vickers hardness (HV) of the nanoclay-reinforced cements was measured between 62 and 89 HV. Nanoclay addition at a higher concentration (4%) resulted in higher wear volume and wear depth. The total wear volumes were less dependent upon abrasion volume and attrition volume. The total wear depths were strongly influenced by attrition depth and to some extent by abrasion depth. The addition of nanoclay

  13. Improving Information Security Risk Management

    ERIC Educational Resources Information Center

    Singh, Anand

    2009-01-01

    manaOptimizing risk to information to protect the enterprise as well as to satisfy government and industry mandates is a core function of most information security departments. Risk management is the discipline that is focused on assessing, mitigating, monitoring and optimizing risks to information. Risk assessments and analyses are critical…

  14. Influence of powder/liquid ratio on the radiodensity and diametral tensile strength of glass ionomer cements

    PubMed Central

    FONSECA, Rodrigo Borges; BRANCO, Carolina Assaf; QUAGLIATTO, Paulo Sérgio; GONÇALVES, Luciano de Souza; SOARES, Carlos José; CARLO, Hugo Lemes; CORRER-SOBRINHO, Lourenço

    2010-01-01

    Objective To determine the influence of P/L ratio on the radiodensity and diametral tensile strength (DTS) of glass ionomer cements. Material and Methods There were 2 factors under study: P/L ratio (manufacturer's recommended P/L ratio and a 50% reduced P/L ratio), and materials (Vitro Molar, Vitro Fil, Vitro Cem conventional GICs and Vitro Fil LC, Ortho Glass LC RMGICs). Five 1-mm-thick samples of each material-P/L ratio were produced for radiodensity evaluation. Samples were x-ray exposed onto Digora phosphor plate and radiodensity was obtained using the software Digora for Windows 2.5 Rev 0. For DTS, five (4.0x8.0 mm) cylinder samples of each material were tested (0.5 mm/min). Data were subjected to one- and two-way ANOVA (5x2) followed by Tukey's HSD test, or Kruskal-Wallis and Dunn's method. For paired comparisons, t-test or Mann-Whitney test were used (a=0.05). Results There was a significant interaction (P=0.001) for the studied factors (materials vs. P/L ratio). Reduced P/L ratio resulted in significantly lower DTS for the RMGICs, but radiodensity was affected for all materials (P<0.05). Conclusions Reduced P/L ratio affected properties of the tested glass ionomer cements. RMGICs were more susceptible to lower values of DTS, but radiodensity decreased for all materials following P/L ratio reduction. PMID:21308288

  15. The role of glass ionomer cement on the remineralization of infected dentin: an in vivo study.

    PubMed

    Kuhn, Eunice; Chibinski, Ana Claudia Rodrigues; Reis, Alessandra; Wambier, Denise Stadler

    2014-01-01

    This study's purpose was to investigate the effect of a glass ionomer cement as a liner over infected unexcavated dentin after 60 days and at 10 to 15 months. Forty-five permanent molars with deep carious lesions were selected. Fragments of carious dentin were removed prior to lining the cavity (baseline sample) with glass ionomer cement (G1) or an inert wax material (G2). Cavities were restored with composite resin and reopened 60 days later, when other fragments were removed (60-day sample). The dentin morphology (scanning electron microscopy) and mineral content of calcium, phosphorus, and fluorine were assessed. During the follow-up periods (60 days and 10 to 15 months), restorations were evaluated and standardized radiographs were taken. A postprocessing routine was used to identify changes in the radiographic density between periods. After 60 days, the dentin exhibited a better organization, fewer bacteria, and signs of remineralization. The weight percents of calcium and phosphorus were higher 60 days after the cavity sealing, regardless of the group. Higher gray levels of carious and sound dentin were seen on the 10- to 15-month radiographs, irrespective of the group. The success rates of G1 and G2 were 89 percent and 88 percent, respectively. The lining material isn't fundamental for caries arrestment. Early (60-day) and late (10 to 15 months) dentin changes occurred, indicating the remineralization of dentin carious tissue.

  16. Atraumatic restorative treatment with resin-modified glass ionomer material: short-term results of a pilot study.

    PubMed

    Dülgergil, Coruh Türksel; Soyman, Mübin; Civelek, Arzu

    2005-01-01

    The aim of this study was to assess the feasibility of the resin-modified glass ionomer (RMGI) material in atraumatic restorative treatment (ART) approach and compare RMGI with the high-strength traditional glass ionomer cement (GIC) in permanent teeth with one or more surface-carious cavities. This study was conducted in a village school in rural southeastern Anatolia, Turkey. The RMGI and GIC restorations with the ART technique were placed randomly employing a split mouth design. In addition, the ART approach was used when necessary for both primary and/or permanent teeth with no pulpal involvement and no perceived pain before treatment. Ninety-one fillings were placed on contralateral molar pairs of 37 children. Baseline and 6-month evaluation of the fillings were made with the classic ART, modified Ryge and USPHS criteria. Based on the ART criteria, 100% of RMGI and 92.4% of GIC restorations were classified as successful after 6 months, and the difference between the 2 groups was statistically significant (p=0.009). While marginal discoloration was the commonest failure in the RMGI group according to both the modified Ryge and USPHS criteria, unsatisfactory surface texture and low anatomic form were the commonly seen failures in the ART technique. Generally, for each rating system, RMGI exhibited better clinical performance than GIC in all categories, except for marginal discoloration. Results based on the 6-month evaluation show that RMGI can be an alternative material to the GIC. Copyright (c) 2005 S. Karger AG, Basel.

  17. Applying management information systems to staffing.

    PubMed

    Hanson, R L

    1982-10-01

    A management information system (MIS) is a tool for managing resources effectively. After reviewing some concepts and principles for effective data management, Hanson clearly applies the concepts to nurse staffing systems, which manage human resources. He defines a seven-step process for establishing an MIS, from defining the management objective to implementing the system. Pointing out that an MIS need not be computerized to be effective, Hanson presents a positive perspective and clarifies some often-misconceived notions about management information systems and the paper printouts they generate. In the next issue of JONA, a second article by Hanson will take a more detailed look at the variety, use, and usefulness of staffing statistics available from an MIS for staffing. These articles are based on material in a forthcoming book, Management Systems for Nursing Service Staffing, to be published by Aspen Systems Corporation, Rockville, Maryland.

  18. ENVIRONMENTAL INFORMATION MANAGEMENT SYSTEM (EIMS)

    EPA Science Inventory

    The Environmental Information Management System (EIMS) organizes descriptive information (metadata) for data sets, databases, documents, models, projects, and spatial data. The EIMS design provides a repository for scientific documentation that can be easily accessed with standar...

  19. Technology Requirements for Information Management

    NASA Technical Reports Server (NTRS)

    Graves, Sara; Knoblock, Craig A.; Lannom, Larry

    2002-01-01

    This report provides the results of a panel study conducted into the technology requirements for information management in support of application domains of particular government interest, including digital libraries, mission operations, and scientific research. The panel concluded that it was desirable to have a coordinated program of R&D that pursues a science of information management focused on an environment typified by applications of government interest - highly distributed with very large amounts of data and a high degree of heterogeneity of sources, data, and users.

  20. IN VITRO INTERACTIONS BETWEEN LACTIC ACID SOLUTION AND ART GLASS-IONOMER CEMENTS

    PubMed Central

    Wang, Linda; Cefaly, Daniela Francisca Gigo; dos Santos, Janaína Lima; dos Santos, Jean Rodrigo; Lauris, José Roberto Pereira; Mondelli, Rafael Francisco Lia; Atta, Maria Teresa

    2009-01-01

    Objectives: Production of acids such as lactic acid contributes to establish a cariogenic environment that leads to dental substrate demineralization. Fluoride plays an important role in this case and, as fluoride-releasing materials, glass-ionomer cements are expected to contribute to minimize deleterious reactions. This study evaluated interactions of glass-ionomer cements used in atraumatic restorative treatment (ART-GICs) with an aqueous lactic acid solution, testing the null hypotheses that no changes occur in the pH of the solution or on the surface roughness and mass of the ART-GICs when exposed to lactic acid solution over a 6-week period. Material and Methods: Ketac Molar, Fuji IX, Vitro Molar and Magic Glass were tested, and compared to Filtek Z250 and Ketac Fil Plus as control groups. Six specimens of each material were made according to manufacturers' instructions. The pH of the solution and roughness and mass changes of each specimen were determined over 6 weeks. Each specimen was individually stored in 2 mL of 0.02 M lactic acid solution for 1 week, renewing the solution every week. pH of solution and mass of the specimens were monitored weekly, and surface roughness of the specimens was assessed before and at the end of the 6-week acid challenge. pH and mass data were analyzed statistically by repeated measures using one-way ANOVA and Tukey's post-hoc tests for each material. Paired t-tests were used for roughness analysis. Tukey's post-hoc tests were applied to verify differences of final roughness among the materials. Significance level was set at 5%. Results: The null hypotheses were partially rejected. All materials were able to increase the pH of the lactic acid solution and presented rougher surfaces after immersion, while mass change was minimal and generally not statistically significant. Conclusions: These findings can be helpful to predict the performance of these materials under clinical conditions. A protective action against the carious

  1. Knowledge-based system for flight information management. Thesis

    NASA Technical Reports Server (NTRS)

    Ricks, Wendell R.

    1990-01-01

    The use of knowledge-based system (KBS) architectures to manage information on the primary flight display (PFD) of commercial aircraft is described. The PFD information management strategy used tailored the information on the PFD to the tasks the pilot performed. The KBS design and implementation of the task-tailored PFD information management application is described. The knowledge acquisition and subsequent system design of a flight-phase-detection KBS is also described. The flight-phase output of this KBS was used as input to the task-tailored PFD information management KBS. The implementation and integration of this KBS with existing aircraft systems and the other KBS is described. The flight tests are examined of both KBS's, collectively called the Task-Tailored Flight Information Manager (TTFIM), which verified their implementation and integration, and validated the software engineering advantages of the KBS approach in an operational environment.

  2. Strategic Information Resources Management: Fundamental Practices.

    ERIC Educational Resources Information Center

    Caudle, Sharon L.

    1996-01-01

    Discusses six fundamental information resources management (IRM) practices in successful organizations that can improve government service delivery performance. Highlights include directing changes, integrating IRM decision making into a strategic management process, performance management, maintaining an investment philosophy, using business…

  3. Marginal ridge fracture resistance, microleakage and pulpal response to glass ionomer/glass cermet partial tunnel restorations.

    PubMed

    Prabhu, N T; Munshi, A K; Shetty, T R

    1997-01-01

    Sixty sound premolars which were to be extracted for orthodontic treatment purposes were restored either with glass ionomer cement or glass cermet cements after partial tunnel preparation, and prior to the extraction after a time interval of 30 and 60 days respectively. The teeth were then subjected to marginal ridge fracture resistance, microleakage study using dye penetration and histological evaluation of the pulpal response to these materials. Both the materials exhibited increase in marginal ridge fracture resistance at 60 days, with minimal degree of microleakage and were biologically compatible with the dental pulp.

  4. 32 CFR 806b.54 - Information collections, records, and forms or information management tools (IMT).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... information management tools (IMT). 806b.54 Section 806b.54 National Defense Department of Defense (Continued..., records, and forms or information management tools (IMT). (a) Information Collections. No information.../pubfiles/af/37/afman37-139/afman37-139.pdf. (c) Forms or Information Management Tools (Adopted and...

  5. 32 CFR 806b.54 - Information collections, records, and forms or information management tools (IMT).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... information management tools (IMT). 806b.54 Section 806b.54 National Defense Department of Defense (Continued..., records, and forms or information management tools (IMT). (a) Information Collections. No information.../pubfiles/af/37/afman37-139/afman37-139.pdf. (c) Forms or Information Management Tools (Adopted and...

  6. 32 CFR 806b.54 - Information collections, records, and forms or information management tools (IMT).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... information management tools (IMT). 806b.54 Section 806b.54 National Defense Department of Defense (Continued..., records, and forms or information management tools (IMT). (a) Information Collections. No information.../pubfiles/af/37/afman37-139/afman37-139.pdf. (c) Forms or Information Management Tools (Adopted and...

  7. 32 CFR 806b.54 - Information collections, records, and forms or information management tools (IMT).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... information management tools (IMT). 806b.54 Section 806b.54 National Defense Department of Defense (Continued..., records, and forms or information management tools (IMT). (a) Information Collections. No information.../pubfiles/af/37/afman37-139/afman37-139.pdf. (c) Forms or Information Management Tools (Adopted and...

  8. 32 CFR 806b.54 - Information collections, records, and forms or information management tools (IMT).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... information management tools (IMT). 806b.54 Section 806b.54 National Defense Department of Defense (Continued..., records, and forms or information management tools (IMT). (a) Information Collections. No information.../pubfiles/af/37/afman37-139/afman37-139.pdf. (c) Forms or Information Management Tools (Adopted and...

  9. Hospital information management system: an evolutionary knowledge management perspective.

    PubMed

    Wadhwa, S; Saxena, Avneet; Wadhwa, Bharat

    2007-01-01

    The evolving paradigm shift resulting from IT, social and technological changes has created a need for developing an innovative knowledge-based healthcare system, which can effectively meet global healthcare system demands and also cater to future trends. The Hospital Information Management System (HIMS) is developed with this sole aim in mind, which helps in processing and management of hospital information not only inside the boundary, but also beyond the hospital boundary, e.g., telemedicine or e-healthcare. The purpose of this paper is to present such kind of functional HIMS, which can efficiently satisfy the current and future system requirements by using Knowledge Management (KM) and data management systems. The HIMS is developed in a KM context, wherein users can share and use the knowledge more effectively. The proposed system is fully compatible with future technical, social, managerial and economical requirements.

  10. Management of information in a research and development agency

    NASA Technical Reports Server (NTRS)

    Keene, Wallace O.

    1990-01-01

    The NASA program for managing scientific and technical information (STI) is examined, noting the technological, managerial, educational, and legal aspects of transferring and disseminating information. A definition of STI is introduced and NASA's STI-related management programs are outlined. Consideration is given to the role of STI management in NASA mission programs, research efforts supporting the management and use of STI, STI program interfaces, and the Automated Information Management Program to eliminate redundant automation efforts in common administrative functions. The infrastructure needed to manage the broad base of NASA information and the interfaces between NASA's STI management and external organizations are described.

  11. Incorporation of casein phosphopeptide-amorphous calcium phosphate into a glass-ionomer cement.

    PubMed

    Mazzaoui, S A; Burrow, M F; Tyas, M J; Dashper, S G; Eakins, D; Reynolds, E C

    2003-11-01

    Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) nanocomplexes have been shown to prevent demineralization and promote remineralization of enamel subsurface lesions in animal and in situ caries models. The aim of this study was to determine the effect of incorporating CPP-ACP into a self-cured glass-ionomer cement (GIC). Incorporation of 1.56% w/w CPP-ACP into the GIC significantly increased microtensile bond strength (33%) and compressive strength (23%) and significantly enhanced the release of calcium, phosphate, and fluoride ions at neutral and acidic pH. MALDI mass spectrometry also showed casein phosphopeptides from the CPP-ACP nanocomplexes to be released. The release of CPP-ACP and fluoride from the CPP-ACP-containing GIC was associated with enhanced protection of the adjacent dentin during acid challenge in vitro.

  12. An ``Alternating-Curvature'' Model for the Nanometer-scale Structure of the Nafion Ionomer, Based on Backbone Properties Detected by NMR

    NASA Astrophysics Data System (ADS)

    Schmidt-Rohr, Klaus; Chen, Q.

    2006-03-01

    The perfluorinated ionomer, Nafion, which consists of a (-CF2-)n backbone and charged side branches, is useful as a proton exchange membrane in H2/O2 fuel cells. A modified model of the nanometer-scale structure of hydrated Nafion will be presented. It features hydrated ionic clusters familiar from some previous models, but is based most prominently on pronounced backbone rigidity between branch points and limited orientational correlation of local chain axes. These features have been revealed by solid-state NMR measurements, which take advantage of fast rotations of the backbones around their local axes. The resulting alternating curvature of the backbones towards the hydrated clusters also better satisfies the requirement of dense space filling in solids. Simulations based on this ``alternating curvature'' model reproduce orientational correlation data from NMR, as well as scattering features such as the ionomer peak and the I(q) ˜ 1/q power law at small q values, which can be attributed to modulated cylinders resulting from the chain stiffness. The shortcomings of previous models, including Gierke's cluster model and more recent lamellar or bundle models, in matching all requirements imposed by the experimental data will be discussed.

  13. 75 FR 68418 - Real-Time System Management Information Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-08

    ...-Time System Management Information Program AGENCY: Federal Highway Administration (FHWA), DOT. ACTION...) to establish a Real-Time System Management Information Program that provides, in all States, the... traveler information. The purposes of the Real-Time System Management Information Program are to: (1...

  14. 76 FR 42536 - Real-Time System Management Information Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-19

    ...-Time System Management Information Program AGENCY: Federal Highway Administration (FHWA), DOT. ACTION... Real-Time System Management Information Program and general information about current and planned... establishing requirements for the Real-Time System Management Information Program on November 8, 2010, at 75 FR...

  15. 41 CFR 105-53.143 - Information Resources Management Service.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Information Resources... FUNCTIONS Central Offices § 105-53.143 Information Resources Management Service. (a) Creation and authority. The Information Resources Management Service (IRMS), headed by the Commissioner, Information Resources...

  16. 41 CFR 105-53.143 - Information Resources Management Service.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false Information Resources... FUNCTIONS Central Offices § 105-53.143 Information Resources Management Service. (a) Creation and authority. The Information Resources Management Service (IRMS), headed by the Commissioner, Information Resources...

  17. 41 CFR 105-53.143 - Information Resources Management Service.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false Information Resources... FUNCTIONS Central Offices § 105-53.143 Information Resources Management Service. (a) Creation and authority. The Information Resources Management Service (IRMS), headed by the Commissioner, Information Resources...

  18. 41 CFR 105-53.143 - Information Resources Management Service.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false Information Resources... FUNCTIONS Central Offices § 105-53.143 Information Resources Management Service. (a) Creation and authority. The Information Resources Management Service (IRMS), headed by the Commissioner, Information Resources...

  19. 41 CFR 105-53.143 - Information Resources Management Service.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false Information Resources... FUNCTIONS Central Offices § 105-53.143 Information Resources Management Service. (a) Creation and authority. The Information Resources Management Service (IRMS), headed by the Commissioner, Information Resources...

  20. DOD Acquisition Information Management

    DTIC Science & Technology

    1994-09-30

    instead of on a real- time management information flow. The process of identifying risks and implementing corrective actions is lengthened by using the current system; performance measurement and reporting are impeded.

  1. Management Information System Based on the Balanced Scorecard

    ERIC Educational Resources Information Center

    Kettunen, Juha; Kantola, Ismo

    2005-01-01

    Purpose: This study seeks to describe the planning and implementation in Finland of a campus-wide management information system using a rigorous planning methodology. Design/methodology/approach: The structure of the management information system is planned on the basis of the management process, where strategic management and the balanced…

  2. Master's Degree in Management Information Systems with a Supply Chain Management Focus

    ERIC Educational Resources Information Center

    Ramaswamy, Kizhanatham V.; Boyd, Joseph L.; Desai, Mayur

    2007-01-01

    A graduate curriculum in Management Information Systems with a Supply Chain Management focus is presented. The motivation for this endeavor stems from the fact that the global scope of modern business organizations and the competitive environment in which they operate, requires an information system leveraged supply chain management system (SCM)…

  3. NASA information resources management handbook

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This National Aeronautics and Space Administration (NASA) Handbook (NHB) implements recent changes to Federal laws and regulations involving the acquisition, management, and use of Federal Information Processing (FIP) resources. This document defines NASA's Information Resources Management (IRM) practices and procedures and is applicable to all NASA personnel. The dynamic nature of the IRM environment requires that the controlling management practices and procedures for an Agency at the leading edge of technology, such as NASA, must be periodically updated to reflect the changes in this environment. This revision has been undertaken to accommodate changes in the technology and the impact of new laws and regulations dealing with IRM. The contents of this document will be subject to a complete review annually to determine its continued applicability to the acquisition, management, and use of FIP resources by NASA. Updates to this document will be accomplished by page changes. This revision cancels NHB 2410.1D, dated April 1985.

  4. Research on Design Information Management System for Leather Goods

    NASA Astrophysics Data System (ADS)

    Lu, Lei; Peng, Wen-li

    The idea of setting up a design information management system of leather goods was put forward to solve the problems existed in current information management of leather goods. Working principles of the design information management system for leather goods were analyzed in detail. Firstly, the acquiring approach of design information of leather goods was introduced. Secondly, the processing methods of design information were introduced. Thirdly, the management of design information in database was studied. Finally, the application of the system was discussed by taking the shoes products as an example.

  5. 32 CFR 903.10 - Information collections, records, and forms or information management tools (IMTS).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Information collections, records, and forms or information management tools (IMTS). 903.10 Section 903.10 National Defense Department of Defense (Continued... Information collections, records, and forms or information management tools (IMTS). (a) Information...

  6. 32 CFR 903.10 - Information collections, records, and forms or information management tools (IMTS).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Information collections, records, and forms or information management tools (IMTS). 903.10 Section 903.10 National Defense Department of Defense (Continued... Information collections, records, and forms or information management tools (IMTS). (a) Information...

  7. 32 CFR 903.10 - Information collections, records, and forms or information management tools (IMTS).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Information collections, records, and forms or information management tools (IMTS). 903.10 Section 903.10 National Defense Department of Defense (Continued... Information collections, records, and forms or information management tools (IMTS). (a) Information...

  8. 32 CFR 903.10 - Information collections, records, and forms or information management tools (IMTS).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Information collections, records, and forms or information management tools (IMTS). 903.10 Section 903.10 National Defense Department of Defense (Continued... Information collections, records, and forms or information management tools (IMTS). (a) Information...

  9. 32 CFR 903.10 - Information collections, records, and forms or information management tools (IMTS).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Information collections, records, and forms or information management tools (IMTS). 903.10 Section 903.10 National Defense Department of Defense (Continued... Information collections, records, and forms or information management tools (IMTS). (a) Information...

  10. Management Information Specialist.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Center on Education and Training for Employment.

    This publication contains 19 subjects appropriate for use in a competency list for the occupation of management information specialist, 1 of 12 occupations within the business/computer technologies cluster. Each unit consists of a number of competencies; a list of competency builders is provided for each competency. Titles of the 19 units are as…

  11. Corporate Information Management: A Case Study

    DTIC Science & Technology

    1991-03-01

    SUBJECT TERMS ( FIELD GROUP SUB-GROUP ICorporate Information Management (CIM), Case study, Strategic level decision making, Department Of Defense. 19...ABSTRACT ( This thesis documents in a case format the events, environment and decisions in the genesis and evolution of the Department of Defense’s...case format the events, environment and decisions in the genesis and evolution of the Department of Defense’s Corporate Information Management

  12. Management information systems in the HMO environment.

    PubMed

    Neal, P A

    1982-01-01

    Realization of the unique potential of a health maintenance organization is dependent on the availability of adequate, accurate, and timely information. The particular data needed are determined by the structure of the organization; the physician compensation plans; requirements for state, federal, or other reporting; and many other factors. The author introduces the concept and objectives of the HMO, and presents the management information systems necessary for planning and monitoring HMO performance: patient information, utilization information, and management information for the staff and nonstaff HMO.

  13. Silk-ionomer and silk-tropoelastin hydrogels as charged three-dimensional culture platforms for the regulation of hMSC response.

    PubMed

    Calabrese, Rossella; Raia, Nicole; Huang, Wenwen; Ghezzi, Chiara E; Simon, Marc; Staii, Cristian; Weiss, Anthony S; Kaplan, David L

    2017-09-01

    The response of human bone marrow-derived mesenchymal stem cells (hMSCs) encapsulated in three-dimensional (3D) charged protein hydrogels was studied. Combining silk fibroin (S) with recombinant human tropoelastin (E) or silk ionomers (I) provided protein composite alloys with tunable physicochemical and biological features for regulating the bioactivity of encapsulated hMSCs. The effects of the biomaterial charges on hMSC viability, proliferation and chondrogenic or osteogenic differentiation were assessed. The silk-tropoelastin or silk-ionomers hydrogels supported hMSC viability, proliferation and differentiation. Gene expression of markers for chondrogenesis and osteogenesis, as well as biochemical and histological analysis, showed that hydrogels with different S/E and S/I ratios had different effects on cell fate. The negatively charged hydrogels upregulated hMSC chondrogenesis or osteogenesis, with or without specific differentiation media, and hydrogels with higher tropoelastin content inhibited the differentiation potential even in the presence of the differentiation media. The results provide insight on charge-tunable features of protein-based biomaterials to control hMSC differentiation in 3D hydrogels, as well as providing a new set of hydrogels for the compatible encapsulation and utility for cell functions. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  14. A fully spray-coated fuel cell membrane electrode assembly using Aquivion ionomer with a graphene oxide/cerium oxide interlayer

    NASA Astrophysics Data System (ADS)

    Breitwieser, Matthias; Bayer, Thomas; Büchler, Andreas; Zengerle, Roland; Lyth, Stephen M.; Thiele, Simon

    2017-05-01

    A novel multilayer membrane electrode assembly (MEA) for polymer electrolyte membrane fuel cells (PEMFCs) is fabricated in this work, within a single spray-coating device. For the first time, direct membrane deposition is used to fabricate a PEMFC by spraying the short-side-chain ionomer Aquivion directly onto the gas diffusion electrodes. The fully sprayed MEA, with an Aquivion membrane 10 μm in thickness, achieved a high power density of 1.6 W/cm2 for H2/air operation at 300 kPaabs. This is one of the highest reported values for thin composite membranes operated in H2/air atmosphere. By the means of confocal laser scanning microscopy, individual carbon fibers from the gas diffusion layer are identified to penetrate through the micro porous layer (MPL), likely causing a low electrical cell resistance in the range of 150 Ω cm2 through the thin sprayed membranes. By spraying a 200 nm graphene oxide/cerium oxide (GO/CeO2) interlayer between two layers of Aquivion ionomer, the impact of the electrical short is eliminated and the hydrogen crossover current density is reduced to about 1 mA/cm2. The peak power density of the interlayer-containing MEA drops only by 10% compared to a pure Aquivion membrane of similar thickness.

  15. Why (just) information is not enough: The contributions of information services in the management of healthcare information

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kostagiolas, P., E-mail: pkostagiolas@ionio.gr; Lappa, E., E-mail: evlappa@med.uoa.gr

    Information is at the centre of every hospital activity including clinical decisions and healthcare service delivery systems. Although information is an important hospital asset, several issues related to its management and organization needs to be addressed within the hospitals. The management of healthcare information is a strategic goal related to the reduction of healthcare service provision costs, and to the improvement of quality and safety of healthcare services. By discussing the rather obvious necessity for information organization and management in the healthcare domain, this work aims at the role of healthcare information services, i.e. hospital libraries and patient medical records.more » Finally, a typology of information services’ contributions to hospital environment is presented.« less

  16. Why (just) information is not enough: The contributions of information services in the management of healthcare information

    NASA Astrophysics Data System (ADS)

    Kostagiolas, P.; Lappa, E.

    2015-02-01

    Information is at the centre of every hospital activity including clinical decisions and healthcare service delivery systems. Although information is an important hospital asset, several issues related to its management and organization needs to be addressed within the hospitals. The management of healthcare information is a strategic goal related to the reduction of healthcare service provision costs, and to the improvement of quality and safety of healthcare services. By discussing the rather obvious necessity for information organization and management in the healthcare domain, this work aims at the role of healthcare information services, i.e. hospital libraries and patient medical records. Finally, a typology of information services' contributions to hospital environment is presented.

  17. MIMS - MEDICAL INFORMATION MANAGEMENT SYSTEM

    NASA Technical Reports Server (NTRS)

    Frankowski, J. W.

    1994-01-01

    MIMS, Medical Information Management System is an interactive, general purpose information storage and retrieval system. It was first designed to be used in medical data management, and can be used to handle all aspects of data related to patient care. Other areas of application for MIMS include: managing occupational safety data in the public and private sectors; handling judicial information where speed and accuracy are high priorities; systemizing purchasing and procurement systems; and analyzing organizational cost structures. Because of its free format design, MIMS can offer immediate assistance where manipulation of large data bases is required. File structures, data categories, field lengths and formats, including alphabetic and/or numeric, are all user defined. The user can quickly and efficiently extract, display, and analyze the data. Three means of extracting data are provided: certain short items of information, such as social security numbers, can be used to uniquely identify each record for quick access; records can be selected which match conditions defined by the user; and specific categories of data can be selected. Data may be displayed and analyzed in several ways which include: generating tabular information assembled from comparison of all the records on the system; generating statistical information on numeric data such as means, standard deviations and standard errors; and displaying formatted listings of output data. The MIMS program is written in Microsoft FORTRAN-77. It was designed to operate on IBM Personal Computers and compatibles running under PC or MS DOS 2.00 or higher. MIMS was developed in 1987.

  18. Information Resource Management Strategic Plan, FY 2007-2011

    ERIC Educational Resources Information Center

    US Department of Education, 2006

    2006-01-01

    The Chief Information Officer (CIO) at the U.S. Department of Education (ED) has primary responsibility to ensure that Information Technology (IT) is acquired and information resources are managed in a manner consistent with statutory, regulatory, and Departmental requirements and priorities. This Department Information Resource Management (IRM)…

  19. Waste Information Management System v. 1.0

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bustamante, David G.; Schade, A. Carl

    WIMS is a functional interface to an Oracle database for managing the required regulatory information about the handling of Hazardous Waste. WIMS does not have a component to track Radiological Waste data. And it does not have the ability to manage sensitive information.

  20. An Approach for Implementation of Project Management Information Systems

    NASA Astrophysics Data System (ADS)

    Běrziša, Solvita; Grabis, Jānis

    Project management is governed by project management methodologies, standards, and other regulatory requirements. This chapter proposes an approach for implementing and configuring project management information systems according to requirements defined by these methodologies. The approach uses a project management specification framework to describe project management methodologies in a standardized manner. This specification is used to automatically configure the project management information system by applying appropriate transformation mechanisms. Development of the standardized framework is based on analysis of typical project management concepts and process and existing XML-based representations of project management. A demonstration example of project management information system's configuration is provided.

  1. Respiratory care management information systems.

    PubMed

    Ford, Richard M

    2004-04-01

    Hospital-wide computerized information systems evolved from the need to capture patient information and perform billing and other financial functions. These systems, however, have fallen short of meeting the needs of respiratory care departments regarding work load assessment, productivity management, and the level of outcome reporting required to support programs such as patient-driven protocols. The respiratory care management information systems (RCMIS) of today offer many advantages over paper-based systems and hospital-wide computer systems. RCMIS are designed to facilitate functions specific to respiratory care, including assessing work demand, assigning and tracking resources, charting, billing, and reporting results. RCMIS incorporate mobile, point-of-care charting and are highly configurable to meet the specific needs of individual respiratory care departments. Important and substantial benefits can be realized with an RCMIS and mobile, wireless charting devices. The initial and ongoing costs of an RCMIS are justified by increased charge capture and reduced costs, by way of improved productivity and efficiency. It is not unusual to recover the total cost of an RCMIS within the first year of its operation. In addition, such systems can facilitate and monitor patient-care protocols and help to efficiently manage the vast amounts of information encountered during the practitioner's workday. Respiratory care departments that invest in RCMIS have an advantage in the provision of quality care and in reducing expenses. A centralized respiratory therapy department with an RCMIS is the most efficient and cost-effective way to monitor work demand and manage the hospital-wide allocation of respiratory care services.

  2. Coating glass-ionomer cements with a nanofilled resin.

    PubMed

    Bonifácio, Clarissa Calil; Werner, Arie; Kleverlaan, Cornelis Johanes

    2012-12-01

    The objective of this study was to investigate the effect of a nanofilled resin coat on the flexural strength (FS) and the early wear (after 50,000 and 200,000 cycles) of the glass-ionomer cements Fuji IX GP Extra (FIXE) and Ketac Molar Aplicap (KM). Specimens were prepared and half of them were coated with G-Coat plus. The uncoated specimens were used as controls. Flexural strength (n = 10) was evaluated after 24 h using a 3-point bending test on a universal testing machine (ISO 9917-2). Wear (n = 20) was evaluated after 50,000 and 200,000 cycles using the ACTA wear machine. One-way, two-way ANOVA and Tukey post-hoc tests were used to analyze differences in FS and wear. For FIXE the coat significantly increased the FS and the wear along the two time spans. KM did not show a significant difference in FS with the coat. Improvements in wear were observed only after 50,000 cycles. Based on these laboratory results, it is concluded that G-coat Plus is indicated in association with GP IX Extra with the aim to improve the mechanical properties of the former. However, this study is limited to a short-term observation.

  3. Hospital information management: the need for clinical leadership.

    PubMed Central

    Wyatt, J. C.

    1995-01-01

    On 12 July the Audit Commission published For Your Information, a well researched report about information and its management in acute hospitals in Britain, how and why it is failing, and steps that clinicians, managers, and the NHS should take to correct this. This article discusses why information management matters to clinicians and considers the problems identified by the Audit Commission--most of which will strike chords with doctors--and possible remedies. Finally, it describes possible routes to administer these remedies and the proposal, recently supported by the BMA Council, for a national centre for health informatics with the goals of educating and enthusing clinicians about informatics, empowering them to participate in local and national information management decisions; exploring how information can be used to improve patient care and outcomes; and evaluating clinical information systems and helping to realise their benefits. PMID:7613433

  4. 75 FR 23218 - Information Collection; Inventory Property Management

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-03

    ... supports Inventory Property Management. The information is used to evaluate applicant requests to purchase... Affairs, Office of Management and Budget, Washington, DC 20503. Copies of the information collection may... DEPARTMENT OF AGRICULTURE Farm Service Agency Information Collection; Inventory Property...

  5. Adaptive resource management and the value of information

    USGS Publications Warehouse

    Williams, Byron K.; Eaton, Mitchell J.; Breininger, David R.

    2011-01-01

    The value of information is a general and broadly applicable concept that has been used for several decades to aid in making decisions in the face of uncertainty. Yet there are relatively few examples of its use in ecology and natural resources management, and almost none that are framed in terms of the future impacts of management decisions. In this paper we discuss the value of information in a context of adaptive management, in which actions are taken sequentially over a timeframe and both future resource conditions and residual uncertainties about resource responses are taken into account. Our objective is to derive the value of reducing or eliminating uncertainty in adaptive decision making. We describe several measures of the value of information, with each based on management objectives that are appropriate for adaptive management. We highlight some mathematical properties of these measures, discuss their geometries, and illustrate them with an example in natural resources management. Accounting for the value of information can help to inform decisions about whether and how much to monitor resource conditions through time.

  6. Adaptive resource management and the value of information

    USGS Publications Warehouse

    Williams, B.K.; Eaton, M.J.; Breininger, D.R.

    2011-01-01

    The value of information is a general and broadly applicable concept that has been used for several decades to aid in making decisions in the face of uncertainty. Yet there are relatively few examples of its use in ecology and natural resources management, and almost none that are framed in terms of the future impacts of management decisions. In this paper we discuss the value of information in a context of adaptive management, in which actions are taken sequentially over a timeframe and both future resource conditions and residual uncertainties about resource responses are taken into account. Our objective is to derive the value of reducing or eliminating uncertainty in adaptive decision making. We describe several measures of the value of information, with each based on management objectives that are appropriate for adaptive management. We highlight some mathematical properties of these measures, discuss their geometries, and illustrate them with an example in natural resources management. Accounting for the value of information can help to inform decisions about whether and how much to monitor resource conditions through time. ?? 2011.

  7. Information Security Assessment of SMEs as Coursework -- Learning Information Security Management by Doing

    ERIC Educational Resources Information Center

    Ilvonen, Ilona

    2013-01-01

    Information security management is an area with a lot of theoretical models. The models are designed to guide practitioners in prioritizing management resources in companies. Information security management education should address the gap between the academic ideals and practice. This paper introduces a teaching method that has been in use as…

  8. Effect of different cavity conditioners on microleakage of glass ionomer cement with a high viscosity in primary teeth

    PubMed Central

    Mazaheri, Romina; Pishevar, Leila; Shichani, Ava Vali; Geravandi, Sanas

    2015-01-01

    Background: Glass ionomer cement is a common material used in pediatric dentistry. The aim of this study was to evaluate the microleakage of high-viscosity glass ionomer restorations in deciduous teeth after conditioning with four different conditioners. Materials and Methods: Fifty intact primary canines were collected. Standard Class V cavities (2 mm × 1.5 mm × 3 mm) were prepared by one operator on all buccal tooth surfaces, including both enamel and dentin. The samples were divided into five groups with different conditioners (no conditioner, 20% acrylic acid, 35% phosphoric acid, 12% citric acid, and 17% ethylenediaminetetraacetic acid [EDTA]). Two-way — ANOVA, Kruskal–Wallis and Mann–Whitney tests were used to compare the means of microleakage between the five groups. The significance level was set at P < 0.05. Results: There was no significant difference between the means of microleakage in incisal (enamel) and gingival (dentin) margins (P = 0.34). Furthermore, there was no significant difference between the means of microleakage in enamel and dentin margins (P = 0.4). There was a significant difference between the means of microleakage in different groups (P = 0.03). Conclusion: Within the limitations of this study, it is suggested that 20% acrylic acid and 17% EDTA be used for cavity conditioning which can result in better chemical and micromechanical adhesion. PMID:26288623

  9. Effect of Two Traditional Polyacrylic Acid Conditioners and 2% Chlorhexidine Digluconate on Cavosurface Microleakage of Glass Ionomer Restorations.

    PubMed

    Lugassy, Diva; Segal, Pnina; Blumer, Sigalit; Eger, Michal; Shely, Asaf; Matalon, Shlomo

    2018-05-11

    A lack of appropriate adhesiveness is one of the biggest problems in restorative dentistry today and the main cause of microleakage. This is especially true in pediatric dentistry where moisture control is more difficult to achieve. Glass ionomer restorative materials increase adhesion and decrease microleakage given their chemical adhesion to the remaining tooth substance. Pretreatment improves the adhesion quality. The aim of this study was to assess the microleakage of Glass ionomer restorative materials following application of 20% polyacrylic acid, 10% polyacrylic acid or 2% chlorhexidine digluconate in Class V cavities. Two Class V preparations were prepared on the buccal and lingual surfaces of 24 extracted human molars. The gingival wall was set below or above the CEJ. The teeth were divided into 2 groups. Group 1 was treated with 20% polyacrylic acid or 10% polyacrylic acid. Group 2 was treated with 10% polyacrylic acid or 2% chlorhexidine digluconate. Microleakage was evaluated using a light-reflecting stereomicroscope and stain penetration test. Two percent chlorhexidine digluconate was as efficient as the other conditioners. No statistically significant differences were found among the three types of conditioners. Dye penetration was significantly greater into dentin than into enamel among all three conditioners in both groups (P<0.001). Two percent chlorhexidine digluconate, with its known added advantages, can be used as a pretreatment conditioner in GI restorations.

  10. Innovations in information management and access for assessments

    PubMed Central

    Champion, Sarah M.; Kunkel, Kenneth E.; Tilmes, Curt

    2017-01-01

    The third National Climate Assessment (NCA3) included goals for becoming a more timely, inclusive, rigorous, and sustained process, and for serving a wider variety of decision makers. In order to accomplish these goals, it was necessary to deliberately design an information management strategy that could serve multiple stakeholders and manage different types of information - from highly mature government-supported climate science data, to isolated practitioner-generated case study information - and to do so in ways that are consistent and appropriate for a highly influential assessment. Meeting the information management challenge for NCA3 meant balancing relevance and authority, complexity and accessibility, inclusivity and rigor. Increasing traceability of data behind figures and graphics, designing a public-facing website, managing hundreds of technical inputs to the NCA, and producing guidance for over 300 participants on meeting the Information Quality Act were all aspects of a deliberate, multi-faceted, and strategic information management approach that nonetheless attempted to be practical and usable for a variety of participants and stakeholders. PMID:29081560

  11. Managing Information Resources for Accessibility.

    ERIC Educational Resources Information Center

    General Services Administration, Washington, DC. Clearinghouse on Computer Accommodation.

    This handbook presents guidance for federal managers and other personnel who are unfamiliar with the policy and practice of information accessibility to accommodate users with disabilities and to provide for their effective access to information resources. It addresses federal requirements for accessibility, adopting accessibility as a sound…

  12. Managing Information Resources: New Directions in State Government.

    ERIC Educational Resources Information Center

    Caudle, Sharon L.; Marchand, Donald A.

    1990-01-01

    Describes a national survey of management policies and practices applied to information and information technology in state government. Management approaches and trends are discussed in the areas of data processing, telecommunications, office automation, records management, state library services, policy formation, budgeting and accounting,…

  13. Information Literacy and the Introductory Management Classroom

    ERIC Educational Resources Information Center

    Leigh, Jennifer S. A.; Gibbon, Cynthia A.

    2008-01-01

    This article proposes that the integration of information literacy standards into the management classroom can address underdeveloped student research strategies and promote effective use of print, digital, and free Web resources. Incorporating information literacy can support management educators in their need to balance disciplinary content,…

  14. Information Management in Business, Libraries and British Military Intelligence: Towards a History of Information Management.

    ERIC Educational Resources Information Center

    Black, Alistair; Brunt, Rodney

    1999-01-01

    This historical study explores a definition of information management that centers on the ordering and channeling of non-publicly available information within organizations. Highlights three types of organizations: the business corporation; the library; and the state agency, specifically British military intelligence. (Contains 44…

  15. Surface finish of resin-modified and highly viscous glass ionomer cements produced by new one-step systems.

    PubMed

    Yap, Adrian U J; Ng, J J; Yap, S H; Teo, C K

    2004-01-01

    This study investigated the surface finish of resin-modified (Fuji II LC, GC) and highly viscous (Fuji IX GP Fast, GC) glass ionomer cements after treatment with three one-step finishing/polishing systems (One-Gloss [OG], Shofu; Pogo [PG], Dentsply; Sof-Lex Brush [SB], 3M-ESPE). The surface roughness obtained was compared to that using a matrix strip [MS], a two-step rubber abrasive (CompoSite [CS], Shofu) and a graded abrasive disk (Super Snap [SS], Shofu) system. Eight specimens (3-mm long x 3-mm wide x 2-mm deep) of each material were made for the various treatment groups. With the exception of the MS group, all groups were roughened with 320 grit grinding paper using a lapping device prior to finishing/polishing with the different systems. The mean surface roughness (microm) was measured with a profilometer. Data was subjected to ANOVA/Scheffe's tests at significance level 0.05. Mean Ra ranged from 0.13 to 1.04 microm for Fuji II LC and 0.14 to 0.81 for Fuji IX GP. For both materials, the smoothest surface was obtained with MS and the roughest with OG. Depending on the materials, the surface finish produced by PG and SB was superior or comparable to that obtained with CS and SS. The effectiveness of one-step systems, when used to finish/polish resin-modified and highly viscous glass ionomer cements, is product dependent.

  16. The use of a reinforced glass-ionomer cermet for the restoration of primary molars: a clinical trial.

    PubMed

    Kilpatrick, N M; Murray, J J; McCabe, J F

    1995-09-09

    The development of adhesive restorative materials has led to more conservative cavity design with greater reliance being placed upon the bond of a material with tooth tissue for retention of the restoration. Glass-ionomer cements may offer particular advantages but have yet to achieve the durability reported for amalgam. This study reports on the results of a 2.5-year prospective clinical trial comparing the durability of two glass-ionomer cements, a conventional material (Ketac Fil) and a metal reinforced cermet (Ketac Silver) in the restoration of Class II lesions in primary molars. Forty-six pairs of restorations were assessed in 37 children. The failure rate of Ketac Fil, 23%, was significantly lower than that of Ketac Silver, 41% (P < 0.05). The median survival time of the Ketac Fil restorations was significantly greater, 25.3 months, than that of the Ketac Silver restorations, 20.3 months (P < 0.05). These values may be an underestimate of the true longevity of both restoration types as many of the restorations survived intact at the censor date. Neither the age of the child nor the tooth restored influenced the durability of the restoration. The deterioration in both marginal integrity and anatomic form of the Ketac Silver restorations was significantly greater than the Ketac Fil restorations (P < 0.05). The durability of Ketac Silver was such that it cannot be recommended for use in restoring carious primary molars.

  17. 75 FR 30857 - Justice Management Division; Office of Attorney Recruitment and Management; Agency Information...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-02

    ... Recruitment and Management; Agency Information Collection Activities: Proposed Collection; Comments Requested... Recruitment and Management (OARM), will be submitting the following information collection request to the... Recruitment and Management, Justice Management Division, U.S. Department of Justice. (4) Affected public who...

  18. Effects of incorporation of nano-fluorapatite or nano-fluorohydroxyapatite on a resin-modified glass ionomer cement.

    PubMed

    Lin, Jun; Zhu, Jiajun; Gu, Xiaoxia; Wen, Wenjian; Li, Qingshan; Fischer-Brandies, Helge; Wang, Huiming; Mehl, Christian

    2011-03-01

    This study aimed to investigate the fluoride release properties and the effect on bond strength of two experimental adhesive cements. Synthesized particles of nano-fluorapatite (nano-FA) or nano-fluorohydroxyapatite (nano-FHA) were incorporated into a resin-modified glass ionomer cement (Fuji Ortho LC) and characterized using X-ray diffraction and scanning electron microscopy. Blocks with six different concentrations of nano-FA or nano-FHA were manufactured and their fluoride release properties evaluated by ultraviolet spectrophotometry. The unaltered glass ionomer cement Fuji Ortho LC (GC, control) and the two experimental cements with the highest fluoride release capacities (nano-FA+Fuji Ortho LC (GFA) and nano-FHA+Fuji Ortho LC (GFHA)) were used to bond composite blocks and orthodontic brackets to human enamel. After 24 h water storage all specimens were debonded, measuring the micro-tensile bond strength (μTBS) and the shear bond strength (SBS), respectively. The optimal concentration of added nano-FA and nano-FHA for maximum fluoride release was 25 wt.%, which nearly tripled fluoride release after 70 days compared with the control group. GC exhibited a significantly higher SBS than GFHA/GFA, with GFHA and GFA not differing significantly (P>0.05). The μTBS of GC and GFA were significantly higher than that of GFHA (P≤0.05). The results seem to indicate that the fluoride release properties of Fuji Ortho LC are improved by incorporating nano-FA or nano-FHA, simultaneously maintaining a clinically sufficient bond strength when nano-FA was added. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  19. Management Information Systems, Planning, and Public Community Colleges.

    ERIC Educational Resources Information Center

    Ritch, Stephen W.; Munro, Robert J.

    Management Information Systems (MIS), originally developed in the areas of accounting, management science, and computer processing, are now being applied to decision-making in educational settings. Definitions of MIS are numerous and often vague, but management systems (as distinguished from other information systems) should promote real-time…

  20. 78 FR 21630 - Comment Request for Information Collection for a Youthful Offender Grants Management Information...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-11

    ... Collection for a Youthful Offender Grants Management Information System, New Collection AGENCY: Employment... is soliciting comments concerning the collection of data for a proposed management information system... permit the Department of Labor to implement a management information system for these various sets of...

  1. Effect of anti-biofilm glass-ionomer cement on Streptococcus mutans biofilms.

    PubMed

    Wang, Su-Ping; Ge, Yang; Zhou, Xue-Dong; Xu, Hockin Hk; Weir, Michael D; Zhang, Ke-Ke; Wang, Hao-Hao; Hannig, Matthias; Rupf, Stefan; Li, Qian; Cheng, Lei

    2016-06-30

    Dental restorative materials with antimicrobial properties can inhibit bacterial colonization, which may result in a reduction of caries at tooth-filling interaction zones. This study aimed to develop antibacterial glass-ionomer cements (GIC) containing a quaternary ammonium monomer (dimethylaminododecyl methacrylate, DMADDM), and to investigate their effect on material performance and antibacterial properties. Different mass fractions (0, 1.1% and 2.2%) of DMADDM were incorporated into the GIC. The flexure strength, surface charge density, surface roughness and fluoride release were tested. A Streptococcus mutans biofilm model was used. Exopolysaccharides (EPS) staining was used to analyze the inhibitory effect of DMADDM on the biofilm matrix. In addition, biofilm metabolic activity, lactic acid metabolism and the expression of glucosyltransferase genes gtfB, gtfC and gtfD were measured. GIC containing 1.1% and 2.2% DMADDM had flexural strengths matching those of the commercial control (P>0.1). DMADDM was able to increase the surface charge density but reduced surface roughness (P<0.05). The incorporation of 1.1% and 2.2% DMADDM elevated the release of fluoride by the GIC in the first 2 days (P<0.05). The novel DMADDM-modified GIC significantly reduced biofilm metabolic activity (P<0.05) and decreased lactic acid production (P<0.05). The quantitative polymerase chain reaction (qPCR) results showed that the expression of gtfB, gtfC and gtfD decreased when mass fractions of DMADDM increased (P<0.05). EPS staining showed that both the bacteria and EPS in biofilm decreased in the DMADDM groups. The incorporation of DMADDM could modify the properties of GIC to influence the development of S. mutans biofilms. In this study, we investigated the interface properties of antibacterial materials for the first time. GIC containing DMADDM can improve material performance and antibacterial properties and may contribute to the better management of secondary caries.

  2. 48 CFR 1852.245-80 - Government property management information.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... management information. 1852.245-80 Section 1852.245-80 Federal Acquisition Regulations System NATIONAL... Provisions and Clauses 1852.245-80 Government property management information. As prescribed in 1845.107-70(k)(1), insert the following provision. Government Property Management Information (JAN 2011) (a) The...

  3. 48 CFR 1852.245-80 - Government property management information.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... management information. 1852.245-80 Section 1852.245-80 Federal Acquisition Regulations System NATIONAL... Provisions and Clauses 1852.245-80 Government property management information. As prescribed in 1845.107-70(k)(1), insert the following provision. Government Property Management Information (JAN 2011) (a) The...

  4. Public Management Information Systems: Theory and Prescription.

    ERIC Educational Resources Information Center

    Bozeman, Barry; Bretschneider, Stuart

    1986-01-01

    The existing theoretical framework for research in management information systems (MIS) is criticized for its lack of attention to the external environment of organizations, and a new framework is developed which better accommodates MIS in public organizations: public management information systems. Four models of publicness that reflect external…

  5. Information management systems for pharmacogenomics.

    PubMed

    Thallinger, Gerhard G; Trajanoski, Slave; Stocker, Gernot; Trajanoski, Zlatko

    2002-09-01

    The value of high-throughput genomic research is dramatically enhanced by association with key patient data. These data are generally available but of disparate quality and not typically directly associated. A system that could bring these disparate data sources into a common resource connected with functional genomic data would be tremendously advantageous. However, the integration of clinical and accurate interpretation of the generated functional genomic data requires the development of information management systems capable of effectively capturing the data as well as tools to make that data accessible to the laboratory scientist or to the clinician. In this review these challenges and current information technology solutions associated with the management, storage and analysis of high-throughput data are highlighted. It is suggested that the development of a pharmacogenomic data management system which integrates public and proprietary databases, clinical datasets, and data mining tools embedded in a high-performance computing environment should include the following components: parallel processing systems, storage technologies, network technologies, databases and database management systems (DBMS), and application services.

  6. Information Resources Management (IRM): A Revolution in Progress.

    ERIC Educational Resources Information Center

    Becker, Louise Giovane

    1980-01-01

    Discusses the emergence of information resources management (IRM) as a focus for managing information activities, particularly those related to federal administration. The IRM office and its manager are described within the context of an organization. Impact of the Paperwork Reduction Act of 1980 on IRM is discussed. (SW)

  7. Data and Information Management: Essential Basis for Sustainable Urban Management and Development

    NASA Astrophysics Data System (ADS)

    Geerders, P.; Kokke, E.

    2011-08-01

    Management of the urban environment and urban development require well organized data and information as a basis for decision making, planning and policy development. Such data and information needs to be up-to-date, reliable and complete, and moreover be available at the time of need. The latter is especially relevant in the case of disasters such as fires, flooding, earthquakes and volcanic eruptions. Current and future impacts of the on-going climate changes increase the need for geo-referenced data and information on environment, biodiversity and public health, in support of preparation, protection, mitigation and reconstruction. It is important that urban authorities devote more attention and resources to data and information management in order to be able to cope with the present and future challenges of ever growing cities with increasing impacts on their surroundings, and moreover to deal with the impacts of environment and biodiversity on the cities, their population and economies. SOD, Woerden has a long and successful track record of certified training and education in the field of data and information management for authorities, including urban government. The courses provided by SOD cover a wide range of subjects from metadata and digitizing, to enterprise content management and geo-information management. While focused on the Netherlands, SOD also has initiated similar training opportunities in Belgium and Surinam, and efforts are under way in other countries. P. Geerders Consultancy has considerable experience as a consultant and trainer in the field of methods and technologies for the provision of information in support of decision-making, planning and policy development related to integrated management and sustainable development of natural resources. Besides in various countries of Europe, he has worked in Latin America and the Caribbean region. Since several years, P. Geerders works as a freelance teacher with SOD. The paper presents a vision on

  8. Academic Information Management--A New Synthesis.

    ERIC Educational Resources Information Center

    Drummond, Marshall Edward

    The design concept and initial development phases of academic information management (AIM) are discussed. The AIM concept is an attempt to serve three segments of academic management with data and models to support decision making. AIM is concerned with management and evaluation of instructional computing in areas other than direct computing (data…

  9. Management/Technical Interaction in Integrated Information System Development.

    ERIC Educational Resources Information Center

    Bagley, Clarence H.; Gardner, Don E.

    The integrated information system element of the management information system concept has practical applications for management in the areas of both information analysis and decision-model building. Four basic options for achieving integration in operational data systems are: a default option, the coordinated file option, the distributed…

  10. Information and Knowledge Management: Dimensions and Approaches

    ERIC Educational Resources Information Center

    Schlögl, Christian

    2005-01-01

    Introduction: Though literature on information and knowledge management is vast, there is much confusion concerning the meaning of these terms. Hence, this article should give some orientation and work out the main aspects of information and knowledge management. Method: An author co-citation analysis, which identified the main dimensions of…

  11. 75 FR 45600 - Information Collection; Customer Data Worksheet Request for Service Center Information Management...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-03

    ... DEPARTMENT OF AGRICULTURE Farm Service Agency Information Collection; Customer Data Worksheet Request for Service Center Information Management System (SCIMS) Record Changes AGENCY: Farm Service... Customer Data Worksheet Request for Service Center Information Management System (SCIMS) that contains the...

  12. 10 CFR 2.1011 - Management of electronic information.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Management of electronic information. 2.1011 Section 2... High-Level Radioactive Waste at a Geologic Repository § 2.1011 Management of electronic information. (a... Language)-compliant (ANSI IX3.135-1992/ISO 9075-1992) database management system (DBMS). Alternatively, the...

  13. Supporting Information Governance through Records and Information Management. Research Bulletin

    ERIC Educational Resources Information Center

    Kaczmarek, Joanne

    2014-01-01

    The expanding scope of IT initiatives in higher education institutions now goes well beyond basic desktop and enterprise applications. IT is often asked to focus on efforts to establish good information-governance practices. The many aspects of information governance are often found in a records and information management (RIM) program, but not…

  14. Security in the management of information systems.

    PubMed

    Huston, T L; Huston, J L

    1998-06-01

    Although security technology exists in abundance in health information management systems, the implementation of that technology is often lacking. This lack of implementation can be heavily affected by the attitudes and perceptions of users and management, the "people part" of systems. Particular operational, organizational, and economic factors must be addressed along with employment of security objectives and accountability. Unique threats, as well as controls, pervade the use of microcomputer-based systems as these systems permeate health care information management.

  15. Managing information technology security risk

    NASA Technical Reports Server (NTRS)

    Gilliam, David

    2003-01-01

    Information Technology (IT) Security Risk Management is a critical task for the organization to protect against the loss of confidentiality, integrity and availability of IT resources. As systems bgecome more complex and diverse and and attacks from intrusions and malicious content increase, it is becoming increasingly difficult to manage IT security risk. This paper describes a two-pronged approach in addressing IT security risk and risk management in the organization: 1) an institutional enterprise appraoch, and 2) a project life cycle approach.

  16. New Information Management Opportunities in a Changing World.

    ERIC Educational Resources Information Center

    Breen, Charlotte; Farragher, Ailish; McQuaid, Mairead; Callanan, Michelle; Burke, Mary A.

    2002-01-01

    Evaluates the gap between traditional library and information studies (LIS) skills and the evolving needs of the information technology workplace. Discusses whether graduates with LIS training are perceived as having the requisite skills and personalities to perform as knowledge managers and information managers in the private sector based on…

  17. 78 FR 59911 - Generic Information Collection for Land Management Planning

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-30

    ... DEPARTMENT OF AGRICULTURE Forest Service Generic Information Collection for Land Management... organizations on the proposed information collection, Generic Information Collection for Land Management... related to forest management. The intent of this generic information collection request (ICR) is to...

  18. Infrastructure of electronic information management

    USGS Publications Warehouse

    Twitchell, G.D.

    2004-01-01

    The information technology infrastructure of an organization, whether it is a private, non-profit, federal, or academic institution, is key to delivering timely and high-quality products and services to its customers and stakeholders. With the evolution of the Internet and the World Wide Web, resources that were once "centralized" in nature are now distributed across the organization in various locations and often remote regions of the country. This presents tremendous challenges to the information technology managers, users, and CEOs of large world-wide corporations who wish to exchange information or get access to resources in today's global marketplace. Several tools and technologies have been developed over recent years that play critical roles in ensuring that the proper information infrastructure exists within the organization to facilitate this global information marketplace Such tools and technologies as JAVA, Proxy Servers, Virtual Private Networks (VPN), multi-platform database management solutions, high-speed telecommunication technologies (ATM, ISDN, etc.), mass storage devices, and firewall technologies most often determine the organization's success through effective and efficient information infrastructure practices. This session will address several of these technologies and provide options related to those that may exist and can be readily applied within Eastern Europe. ?? 2004 - IOS Press and the authors. All rights reserved.

  19. Physician Information Needs in Managing Delirium

    PubMed Central

    Taft, Teresa; Nelsen, Scott D; Slager, Stacey; Weir, Charlene

    2017-01-01

    Delirium has the highest occurrence rate of any complication in hospitalized adults over the age of 65. The study objective was to determine physician information needs for use in the development of electronic clinical decision support for physicians managing the care of patients with delirium. Critical incident interviews were conducted with 8 experienced internal medicine physicians and 1 cardiologist. Thematic analysis revealed the following 6 themes: 1) Clinician’s experience an impoverished information field for mental status, 2) Uncertainty is pervasive, 3) Extensive information foraging effort is required for cohesive story building, 4) Goal Conflict leads to missed diagnosis and early closure, 5) Diffusion of Responsibility for treating delirium is common, and 6) Use of structured delirium resources is minimal. Elicited information needs were identified and physician recommendations for improving access to information needed in managing the care of patient’s with delirium are reported. Information elicited in this study is useful for designing delirium clinical decision support that supports physician cognition.

  20. Engineering Information Infrastructure for Product Lifecycle Managment

    NASA Astrophysics Data System (ADS)

    Kimura, Fumihiko

    For proper management of total product life cycle, it is fundamentally important to systematize design and engineering information about product systems. For example, maintenance operation could be more efficiently performed, if appropriate parts design information is available at the maintenance site. Such information shall be available as an information infrastructure for various kinds of engineering operations, and it should be easily accessible during the whole product life cycle, such as transportation, marketing, usage, repair/upgrade, take-back and recycling/disposal. Different from the traditional engineering database, life cycle support information has several characteristic requirements, such as flexible extensibility, distributed architecture, multiple viewpoints, long-time archiving, and product usage information, etc. Basic approaches for managing engineering information infrastructure are investigated, and various information contents and associated life cycle applications are discussed.

  1. Suppression of oxygen reduction reaction activity on Pt-based electrocatalysts from ionomer incorporation

    NASA Astrophysics Data System (ADS)

    Shinozaki, Kazuma; Morimoto, Yu; Pivovar, Bryan S.; Kocha, Shyam S.

    2016-09-01

    The impact of Nafion on the oxygen reduction reaction (ORR) activity is studied for Pt/C and Pt-alloy/C catalysts using thin-film rotating disk electrode (TF-RDE) methods in 0.1 M HClO4. Ultrathin uniform catalyst layers and standardized activity measurement protocols are employed to obtain accurate and reproducible ORR activity. Nafion lowers the ORR activity which plateaus with increasing loading on Pt catalysts. Pt particle size is found not to have significant influence on the extent of the SA decrease upon Nafion incorporation. Catalysts using high surface area carbon (HSC) support exhibit attenuated activity loss resulting from lower ionomer coverage on catalyst particles located within the deep pores. The impact of metallic composition on the activity loss due to Nafion incorporation is also discussed.

  2. Suppression of oxygen reduction reaction activity on Pt-based electrocatalysts from ionomer incorporation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shinozaki, Kazuma; Morimoto, Yu; Pivovar, Bryan S.

    The impact of Nafion on the oxygen reduction reaction (ORR) activity is studied for Pt/C and Pt-alloy/C catalysts using thin-film rotating disk electrode (TF-RDE) methods in 0.1 M HClO4. Ultrathin uniform catalyst layers and standardized activity measurement protocols are employed to obtain accurate and reproducible ORR activity. Nafion lowers the ORR activity which plateaus with increasing loading on Pt catalysts. Pt particle size is found not to have significant influence on the extent of the SA decrease upon Nafion incorporation. Catalysts using high surface area carbon (HSC) support exhibit attenuated activity loss resulting from lower ionomer coverage on catalyst particlesmore » located within the deep pores. The impact of metallic composition on the activity loss due to Nafion incorporation is also discussed.« less

  3. Infrastructure Management Information System User Manual

    DOT National Transportation Integrated Search

    1998-10-01

    This publication describes and explains the user interface for the Infrastructure Management Information System (IMIS). The IMIS is designed to answer questions regarding public water supply, wastewater treatment, and census information. This publica...

  4. Managing Personal and Group Collections of Information

    NASA Technical Reports Server (NTRS)

    Wolfe, Shawn R.; Wragg, Stephen D.; Chen, James R.; Koga, Dennis (Technical Monitor)

    1999-01-01

    The internet revolution has dramatically increased the amount of information available to users. Various tools such as search engines have been developed to help users find the information they need from this vast repository. Users often also need tools to help manipulate the growing amount of useful information they have discovered. Current tools available for this purpose are typically local components of web browsers designed to manage URL bookmarks. They provide limited functionalities to handle high information complexities. To tackle this have created DIAMS, an agent-based tool to help users or groups manage their information collections and share their collections with other. the main features of DIAMS are described here.

  5. Laboratory Information Systems Management and Operations.

    PubMed

    Cucoranu, Ioan C

    2015-06-01

    The main mission of a laboratory information system (LIS) is to manage workflow and deliver accurate results for clinical management. Successful selection and implementation of an anatomic pathology LIS is not complete unless it is complemented by specialized information technology support and maintenance. LIS is required to remain continuously operational with minimal or no downtime and the LIS team has to ensure that all operations are compliant with the mandated rules and regulations. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Policy, Procedures and Standards for Enterprise Information Management

    EPA Pesticide Factsheets

    This policy establishes a standard approach for managing information produced by, funded by, or received per regulated reporting and/or federal-wide requirements and subsequently held or cataloged in information management systems by EPA.

  7. Information Management of Web Application Based Environmental Performance Management in Concentrating Division of PTFI

    NASA Astrophysics Data System (ADS)

    Susanto, Arif; Mulyono, Nur Budi

    2018-02-01

    The changes of environmental management system standards into the latest version, i.e. ISO 14001:2015, may cause a change on a data and information need in decision making and achieving the objectives in the organization coverage. Information management is the organization's responsibility to ensure that effectiveness and efficiency start from its creating, storing, processing and distribution processes to support operations and effective decision making activity in environmental performance management. The objective of this research was to set up an information management program and to adopt the technology as the supporting component of the program which was done by PTFI Concentrating Division so that it could be in line with the desirable organization objective in environmental management based on ISO 14001:2015 environmental management system standards. Materials and methods used covered technical aspects in information management, i.e. with web-based application development by using usage centered design. The result of this research showed that the use of Single Sign On gave ease to its user to interact further on the use of the environmental management system. Developing a web-based through creating entity relationship diagram (ERD) and information extraction by conducting information extraction which focuses on attributes, keys, determination of constraints. While creating ERD is obtained from relational database scheme from a number of database from environmental performances in Concentrating Division.

  8. Information Architecture for Quality Management Support in Hospitals.

    PubMed

    Rocha, Álvaro; Freixo, Jorge

    2015-10-01

    Quality Management occupies a strategic role in organizations, and the adoption of computer tools within an aligned information architecture facilitates the challenge of making more with less, promoting the development of a competitive edge and sustainability. A formal Information Architecture (IA) lends organizations an enhanced knowledge but, above all, favours management. This simplifies the reinvention of processes, the reformulation of procedures, bridging and the cooperation amongst the multiple actors of an organization. In the present investigation work we planned the IA for the Quality Management System (QMS) of a Hospital, which allowed us to develop and implement the QUALITUS (QUALITUS, name of the computer application developed to support Quality Management in a Hospital Unit) computer application. This solution translated itself in significant gains for the Hospital Unit under study, accelerating the quality management process and reducing the tasks, the number of documents, the information to be filled in and information errors, amongst others.

  9. One-Way Multishape-Memory Effect and Tunable Two-Way Shape Memory Effect of Ionomer Poly(ethylene-co-methacrylic acid).

    PubMed

    Lu, Lu; Li, Guoqiang

    2016-06-15

    Reversible elongation by cooling and contraction by heating, without the need for repeated programming, is well-known as the two-way shape-memory effect (2W-SME). This behavior is contrary to the common physics-contraction when cooling and expansion when heating. Materials with such behavior may find many applications in real life, such as self-sufficient grippers, fastening devices, optical gratings, soft actuators, and sealant. Here, it is shown that ionomer Surlyn 8940, a 50-year old polymer, exhibits both one-way multishape-memory effects and tunable two-way reversible actuation. The required external tensile stress to trigger the tunable 2W-SME is very low when randomly jumping the temperatures within the melting transition window. With a proper one-time programming, "true" 2W-SME (i.e., 2W-SME without the need for an external tensile load) is also achieved. A long training process is not needed to trigger the tunable 2W-SME. Instead, a proper one-time tensile programming is sufficient to trigger repeated and tunable 2W-SME. Because the 2W-SME of the ionomer Surlyn is driven by the thermally reversible network, here crystallization and melting transitions of the semicrystalline poly(ethylene-co-methacrylic acid), it is believed that a class of thermally reversible polymers should also exhibit tunable 2W-SMEs.

  10. Incident Management in Academic Information System using ITIL Framework

    NASA Astrophysics Data System (ADS)

    Palilingan, V. R.; Batmetan, J. R.

    2018-02-01

    Incident management is very important in order to ensure the continuity of a system. Information systems require incident management to ensure information systems can provide maximum service according to the service provided. Many of the problems that arise in academic information systems come from incidents that are not properly handled. The objective of this study aims to find the appropriate way of incident management. The incident can be managed so it will not be a big problem. This research uses the ITIL framework to solve incident problems. The technique used in this study is a technique adopted and developed from the service operations section of the ITIL framework. The results of this research found that 84.5% of incidents appearing in academic information systems can be handled quickly and appropriately. 15.5% incidents can be escalated so as to not cause any new problems. The model of incident management applied to make academic information system can run quickly in providing academic service in a good and efficient. The incident management model implemented in this research is able to manage resources appropriately so as to quickly and easily manage incidents.

  11. Comparison of Micro-Leakage from Resin-Modified Glass Ionomer Restorations in Cavities Prepared by Er:YAG (Erbium-Doped Yttrium Aluminum Garnet) Laser and Conventional Method in Primary Teeth

    PubMed Central

    Bahrololoomi, Zahra; Razavi, Forooghosadat; Soleymani, Ali Asghar

    2014-01-01

    Introduction: In recent years, significant developments have been taking place in caries removal and cavity preparation using laser in dentistry. As laser use is considered for cavity preparation, it is necessary to determine the quality of restoration margins. Glass ionomer cements have great applications for conservative restoration in the pediatric field. The purpose of this in vitro study was to compare resin-modified glass ionomer restorations micro-leakage in cavities prepared by Er:YAG (Erbium-Doped Yttrium Aluminum Garnet) laser irradiation and conventional method in primary teeth. Methods: This was an in vitro experimental study. Forty primary canine teeth were divided into 2 groups: group 1 represented cavities prepared by the no. 008 diamond bur, group 2 represented cavities prepared by Er:YAG laser. After cavity preparation, samples were restored by resin-modified glass ionomer. The teeth were thermocycled for 700 cycles, placed in 2% methylene blue for 24h and sectioned in the buccolingual direction. The degree of dye penetration was scored by 3 examiners. Data was analyzed using Mann-Whitney Test. Results: There was no statistical difference in micro-leakage between the two modes of cavity preparation (P=0.862) Conclusion: Since preparing conservative cavities is very important in pediatric dentistry, it is possible to use Er:YAG laser because of its novel and portable technology. However, further investigations of other restorative materials and other laser powers are required. PMID:25653819

  12. Information Landscaping: Information Mapping, Charting, Querying and Reporting Techniques for Total Quality Knowledge Management.

    ERIC Educational Resources Information Center

    Tsai, Bor-sheng

    2003-01-01

    Total quality management and knowledge management are merged and used as a conceptual model to direct and develop information landscaping techniques through the coordination of information mapping, charting, querying, and reporting. Goals included: merge citation analysis and data mining, and apply data visualization and information architecture…

  13. The effect of CO2 laser irradiation plus fluoride dentifrice on the inhibition of secondary caries on root surfaces adjacent to glass ionomer cement or composite resin restorations

    NASA Astrophysics Data System (ADS)

    Rodrigues, S. R.; Moraes, M.; Hanashiro, F. S.; Youssef, M. N.; Brugnera Junior, A.; Nobre-dos-Santos, M.; de Souza-Zaroni, W. C.

    2016-02-01

    Although the cariostatic effects of CO2 laser on the root surface have been shown, there is scarce information regarding its effects on root secondary caries. The objective of this research was to investigate the effect of the association of CO2 laser and a fluoride dentifrice on the inhibition of secondary caries on root surfaces adjacent to composite-resin or glass-ionomer-cement restorations. Dental blocks of human roots were divided into two groups: composite resin (CR) or glass ionomer cement (GIC). Subsequently, the blocks were divided into four subgroups (n  =  10): C, non-fluoride dentifrice; FD, fluoride dentifrice; L, CO2 laser with an energy density of 6.0 J cm-2  +  non-fluoride dentifrice; and L  +  FD, CO2 laser  +  fluoride dentifrice. The blocks were subjected to pH cycling to simulate a high cariogenic challenge. Dental demineralization around the restorations was quantified by microhardness analysis. The results were subjected to analysis of variance (ANOVA) and the Tukey-Kramer test (p  ⩽  0.05). As for mineral loss, it can be observed that all the groups that were treated with a fluoride dentifrice and laser, used alone or not, were statistically similar and superior to the RC-C group. It was concluded that CO2 laser irradiation and a fluoride dentifrice used alone or combined with each other are efficient surface treatments for preventing secondary root caries, regardless of the restorative material used.

  14. 78 FR 47273 - Information Collection; Inventory Property Management

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-05

    ... collection that supports Inventory Property Management. The information is used to evaluate applicant... DEPARTMENT OF AGRICULTURE Farm Service Agency Information Collection; Inventory Property Management AGENCY: Farm Service Agency, USDA. ACTION: Notice; request for comments. SUMMARY: In accordance...

  15. Geographic Information System (GIS) capabilities in traffic accident information management: a qualitative approach.

    PubMed

    Ahmadi, Maryam; Valinejadi, Ali; Goodarzi, Afshin; Safari, Ameneh; Hemmat, Morteza; Majdabadi, Hesamedin Askari; Mohammadi, Ali

    2017-06-01

    Traffic accidents are one of the more important national and international issues, and their consequences are important for the political, economical, and social level in a country. Management of traffic accident information requires information systems with analytical and accessibility capabilities to spatial and descriptive data. The aim of this study was to determine the capabilities of a Geographic Information System (GIS) in management of traffic accident information. This qualitative cross-sectional study was performed in 2016. In the first step, GIS capabilities were identified via literature retrieved from the Internet and based on the included criteria. Review of the literature was performed until data saturation was reached; a form was used to extract the capabilities. In the second step, study population were hospital managers, police, emergency, statisticians, and IT experts in trauma, emergency and police centers. Sampling was purposive. Data was collected using a questionnaire based on the first step data; validity and reliability were determined by content validity and Cronbach's alpha of 75%. Data was analyzed using the decision Delphi technique. GIS capabilities were identified in ten categories and 64 sub-categories. Import and process of spatial and descriptive data and so, analysis of this data were the most important capabilities of GIS in traffic accident information management. Storing and retrieving of descriptive and spatial data, providing statistical analysis in table, chart and zoning format, management of bad structure issues, determining the cost effectiveness of the decisions and prioritizing their implementation were the most important capabilities of GIS which can be efficient in the management of traffic accident information.

  16. Distributed Information System Development: Review of Some Management Issues

    NASA Astrophysics Data System (ADS)

    Mishra, Deepti; Mishra, Alok

    Due to the proliferation of the Internet and globalization, distributed information system development is becoming popular. In this paper we have reviewed some significant management issues like process management, project management, requirements management and knowledge management issues which have received much attention in distributed development perspective. In this literature review we found that areas like quality and risk management issues could get only scant attention in distributed information system development.

  17. Thermally Cross-Linked Anion Exchange Membranes from Solvent Processable Isoprene Containing Ionomers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tsai, Tsung-Han; Ertem, S. Piril; Maes, Ashley M.

    2015-01-28

    Random copolymers of isoprene and 4-vinylbenzyl chloride (VBCl) with varying compositions were synthesized via nitroxide-mediated polymerization. Subsequent quaternization afforded solvent processable and cross-linkable ionomers with a wide range of ion exchange capacities (IECs). Solution cast membranes were thermally cross-linked to form anion exchange membranes. Cross-linking was achieved by taking advantage of the unsaturations on the polyisoprene backbone, without added cross-linkers. A strong correlation was found between water uptake and ion conductivity of the membranes: conductivities of the membranes with IECs beyond a critical value were found to be constant related to their high water absorption. Environmentally controlled small-angle X-ray scatteringmore » experiments revealed a correlation between the average distance between ionic clusters and the ion conductivity, indicating that a well-connected network of ion clusters is necessary for efficient ion conduction and high ion conductivity.« less

  18. Managing Knowledge And Information In The Sustainable Organization

    NASA Astrophysics Data System (ADS)

    Grecu, Valentin

    2015-09-01

    Knowledge and information management are essential for the success of organizations and bring significant competitive advantages. There has been significant investments in setting up technological platforms that support business processes and increase the efficiency of operational structure in many organizations through an efficient management of knowledge and information. This research highlights the importance of using knowledge and information management in order to increase the competitiveness of organizations and to foster the transition towards the sustainable organization, as nowadays an organization that wants to be competitive needs to be sustainable.

  19. [The development of hospital medical supplies information management system].

    PubMed

    Cao, Shaoping; Gu, Hongqing; Zhang, Peng; Wang, Qiang

    2010-05-01

    The information management of medical materials by using high-tech computer, in order to improve the efficiency of the consumption of medical supplies, hospital supplies and develop a new technology way to manage the hospital and material support. Using C # NET, JAVA techniques to develop procedures for the establishment of hospital material management information system, set the various management modules, production of various statistical reports, standard operating procedures. The system is convenient, functional and strong, fluent statistical functions. It can always fully grasp and understand the whole hospital supplies run dynamic information, as a modern and effective tool for hospital materials management.

  20. Using rangeland health assessment to inform successional management

    USDA-ARS?s Scientific Manuscript database

    Rangeland health assessment provides qualitative information on ecosystem attributes. Successional management is a conceptual framework that allows managers to link information gathered in rangeland health assessment to ecological processes that need to be repaired to allow vegetation to change in ...

  1. Effective Utilization and Management of Emerging Information Technologies. Information Resources Management Association International Conference (Boston, Massachusetts, May 17-20, 1998).

    ERIC Educational Resources Information Center

    Khosrowpour, Mehdi, Ed.

    This proceeding of the 1998 Information Resources Management Association International Conference contains 80 full papers, 87 research in progress papers, 33 abstracts, and 15 panel, workshop, and tutorial summaries. The papers focus on issues of managing information technology (IT) in organizations around the world. Issues covered include:…

  2. Student Perceptions in Teaching Principles of Management Information Systems

    ERIC Educational Resources Information Center

    Rob, Mohammad A.; Etnyre, Vance

    2015-01-01

    Teaching concepts of information systems to general business students through a course such as management information systems (MIS) can be challenging in today's fast-changing environment of information technology (IT). Such a course must provide not only an understanding of the development, applications, and management of information systems, but…

  3. Enabling information management systems in tactical network environments

    NASA Astrophysics Data System (ADS)

    Carvalho, Marco; Uszok, Andrzej; Suri, Niranjan; Bradshaw, Jeffrey M.; Ceccio, Philip J.; Hanna, James P.; Sinclair, Asher

    2009-05-01

    Net-Centric Information Management (IM) and sharing in tactical environments promises to revolutionize forward command and control capabilities by providing ubiquitous shared situational awareness to the warfighter. This vision can be realized by leveraging the tactical and Mobile Ad hoc Networks (MANET) which provide the underlying communications infrastructure, but, significant technical challenges remain. Enabling information management in these highly dynamic environments will require multiple support services and protocols which are affected by, and highly dependent on, the underlying capabilities and dynamics of the tactical network infrastructure. In this paper we investigate, discuss, and evaluate the effects of realistic tactical and mobile communications network environments on mission-critical information management systems. We motivate our discussion by introducing the Advanced Information Management System (AIMS) which is targeted for deployment in tactical sensor systems. We present some operational requirements for AIMS and highlight how critical IM support services such as discovery, transport, federation, and Quality of Service (QoS) management are necessary to meet these requirements. Our goal is to provide a qualitative analysis of the impact of underlying assumptions of availability and performance of some of the critical services supporting tactical information management. We will also propose and describe a number of technologies and capabilities that have been developed to address these challenges, providing alternative approaches for transport, service discovery, and federation services for tactical networks.

  4. Solid state nuclear magnetic resonance investigation of polymer backbone dynamics in poly(ethylene oxide) based lithium and sodium polyether-ester-sulfonate ionomers.

    PubMed

    Roach, David J; Dou, Shichen; Colby, Ralph H; Mueller, Karl T

    2013-05-21

    Polymer backbone dynamics of single ion conducting poly(ethylene oxide) (PEO)-based ionomer samples with low glass transition temperatures (T(g)) have been investigated using solid-state nuclear magnetic resonance. Experiments detecting (13)C with (1)H decoupling under magic angle spinning (MAS) conditions identified the different components of the polymer backbone (PEO spacer and isophthalate groups) and their relative mobilities for a suite of lithium- and sodium-containing ionomer samples with varying cation contents. Variable temperature (203-373 K) (1)H-(13)C cross-polarization MAS (CP-MAS) experiments also provided qualitative assessment of the differences in the motions of the polymer backbone components as a function of cation content and identity. Each of the main backbone components exhibit distinct motions, following the trends expected for motional characteristics based on earlier Quasi Elastic Neutron Scattering and (1)H spin-lattice relaxation rate measurements. Previous (1)H and (7)Li spin-lattice relaxation measurements focused on both the polymer backbone and cation motion on the nanosecond timescale. The studies presented here assess the slower timescale motion of the polymer backbone allowing for a more comprehensive understanding of the polymer dynamics. The temperature dependences of (13)C linewidths were used to both qualitatively and quantitatively examine the effects of cation content and identity on PEO spacer mobility. Variable contact time (1)H-(13)C CP-MAS experiments were used to further assess the motions of the polymer backbone on the microsecond timescale. The motion of the PEO spacer, reported via the rate of magnetization transfer from (1)H to (13)C nuclei, becomes similar for T≳1.1 T(g) in all ionic samples, indicating that at similar elevated reduced temperatures the motions of the polymer backbones on the microsecond timescale become insensitive to ion interactions. These results present an improved picture, beyond those of

  5. The Research on Safety Management Information System of Railway Passenger Based on Risk Management Theory

    NASA Astrophysics Data System (ADS)

    Zhu, Wenmin; Jia, Yuanhua

    2018-01-01

    Based on the risk management theory and the PDCA cycle model, requirements of the railway passenger transport safety production is analyzed, and the establishment of the security risk assessment team is proposed to manage risk by FTA with Delphi from both qualitative and quantitative aspects. The safety production committee is also established to accomplish performance appraisal, which is for further ensuring the correctness of risk management results, optimizing the safety management business processes and improving risk management capabilities. The basic framework and risk information database of risk management information system of railway passenger transport safety are designed by Ajax, Web Services and SQL technologies. The system realizes functions about risk management, performance appraisal and data management, and provides an efficient and convenient information management platform for railway passenger safety manager.

  6. Effect of chlorhexidine disinfectant on bond strength of glass ionomer cement to dentin using atraumatic restorative treatment.

    PubMed

    Wadenya, Rose; Menon, Sandhya; Mante, Francis

    2011-01-01

    This study investigated the effect of 2% chlorhexidine gluconate (CHX) disinfectant on bond strength (BS) of high-density glass ionomer cement (HDGIC) to dentin following atraumatic restorative treatment (ART) and conventional preparations. Specimens were divided into four groups: Group 1--ART (control); Group 2--ART with CHX disinfection; Group 3--Conventional (control); Group 4--Conventional with CHX disinfection. HDGIC was packed in cylindrical molds placed over flat dentin surfaces; BS was measured after seven days. ART-prepared dentin surfaces disinfected with CHX provided bonding to HDGIC that was comparable to untreated dentin and to conventionally prepared dentin.

  7. 48 CFR 1511.011-79 - Information resources management.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Information resources management. 1511.011-79 Section 1511.011-79 Federal Acquisition Regulations System ENVIRONMENTAL PROTECTION AGENCY ACQUISITION PLANNING DESCRIBING AGENCY NEEDS 1511.011-79 Information resources management. The...

  8. 48 CFR 1511.011-79 - Information resources management.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false Information resources management. 1511.011-79 Section 1511.011-79 Federal Acquisition Regulations System ENVIRONMENTAL PROTECTION AGENCY ACQUISITION PLANNING DESCRIBING AGENCY NEEDS 1511.011-79 Information resources management. The...

  9. 48 CFR 1511.011-79 - Information resources management.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 6 2013-10-01 2013-10-01 false Information resources management. 1511.011-79 Section 1511.011-79 Federal Acquisition Regulations System ENVIRONMENTAL PROTECTION AGENCY ACQUISITION PLANNING DESCRIBING AGENCY NEEDS 1511.011-79 Information resources management. The...

  10. 48 CFR 1511.011-79 - Information resources management.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false Information resources management. 1511.011-79 Section 1511.011-79 Federal Acquisition Regulations System ENVIRONMENTAL PROTECTION AGENCY ACQUISITION PLANNING DESCRIBING AGENCY NEEDS 1511.011-79 Information resources management. The...

  11. 48 CFR 1511.011-79 - Information resources management.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Information resources management. 1511.011-79 Section 1511.011-79 Federal Acquisition Regulations System ENVIRONMENTAL PROTECTION AGENCY ACQUISITION PLANNING DESCRIBING AGENCY NEEDS 1511.011-79 Information resources management. The...

  12. 75 FR 56501 - Information Collection; Land Management Agency Volunteer Surveys

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-16

    ... Information Collection; Land Management Agency Volunteer Surveys AGENCY: Forest Service, USDA. ACTION: Notice... and test models of volunteer management; supply information to LMA program managers and other... is seeking comments from all interested individuals and organizations on the new information...

  13. Geographic Information System (GIS) capabilities in traffic accident information management: a qualitative approach

    PubMed Central

    Ahmadi, Maryam; Valinejadi, Ali; Goodarzi, Afshin; Safari, Ameneh; Hemmat, Morteza; Majdabadi, Hesamedin Askari; Mohammadi, Ali

    2017-01-01

    Background Traffic accidents are one of the more important national and international issues, and their consequences are important for the political, economical, and social level in a country. Management of traffic accident information requires information systems with analytical and accessibility capabilities to spatial and descriptive data. Objective The aim of this study was to determine the capabilities of a Geographic Information System (GIS) in management of traffic accident information. Methods This qualitative cross-sectional study was performed in 2016. In the first step, GIS capabilities were identified via literature retrieved from the Internet and based on the included criteria. Review of the literature was performed until data saturation was reached; a form was used to extract the capabilities. In the second step, study population were hospital managers, police, emergency, statisticians, and IT experts in trauma, emergency and police centers. Sampling was purposive. Data was collected using a questionnaire based on the first step data; validity and reliability were determined by content validity and Cronbach’s alpha of 75%. Data was analyzed using the decision Delphi technique. Results GIS capabilities were identified in ten categories and 64 sub-categories. Import and process of spatial and descriptive data and so, analysis of this data were the most important capabilities of GIS in traffic accident information management. Conclusion Storing and retrieving of descriptive and spatial data, providing statistical analysis in table, chart and zoning format, management of bad structure issues, determining the cost effectiveness of the decisions and prioritizing their implementation were the most important capabilities of GIS which can be efficient in the management of traffic accident information. PMID:28848627

  14. 76 FR 43331 - Labor-Management Relations Information Collection Requests

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-20

    ... FEDERAL MEDIATION AND CONCILIATION SERVICE Labor-Management Relations Information Collection... the following public information collection requests (ICR) to the Office of Management and Budget (OMB... information collection requests are FMCS forms: Arbitrator's Report and Fee Statement (Agency Form R-19...

  15. Reactions in glass-ionomer cements: IV. Effect of chelating comonomers on setting behavior.

    PubMed

    Wilson, A D; Crisp, S; Ferner, A J

    1976-01-01

    The oscillating rheometer is a valuable instrument for studying the effects of additives on the setting behavior of a cement system. Using this instrument, it was found that certain chelating comonomers, the hydroxycarboxylic acids, could improve the setting characteristics of the glass-ionomer cement system when added to the PAA solution. The acid chelates probably assign the extraction of metal ions from the glass and also tend to hold them in solution, preventing premature ion binding of the polyanion chains. The effect is to increase the rate of hardening without reducing the working time, which may indeed by slightly increased. Tartaric acid, the most effective of the comonomers, can form a chelate bridge between aluminum atoms, and this metal complex probably acts as a flexible bridge structure linking polyanion chains. This mechanism offers some steric advantages over a simple salt bridge.

  16. Phosphate stresses affect ionome and metabolome in tea plants.

    PubMed

    Ding, Zhaotang; Jia, Sisi; Wang, Yu; Xiao, Jun; Zhang, Yinfei

    2017-11-01

    In order to study the response of tea plants to P stress, we conducted the ionomic and metabolomic analysis by ICP-OES, GC-MS and LC-MS. The results demonstrated that P was antagonistic with S, and was cooperative with Cu, Zn, Mn and Fe under P-deficiency. However, P was antagonistic with Mn, Fe and S, and was cooperative with Cu and Zn under P-excess. Moreover, P-deficiency or excess reduced the syntheses of flavonoids and phosphorylated metabolites. P-deficiency decreased the amount of glutamate and increased the content of glutamine, while P-excess decreased the content of glutamine. Besides, P-deficiency increased three organic acids and decreased three organic acids. P-excess increased the contents of malic acid, oxalic acid, ribonic acid and etc. involved in primary metabolism, but decreased the contents of p-coumaric acid, indoleacrylic acid, related to secondary metabolism. Furthermore, the contents of Mn and Zn were found to be positively related to the amounts of myricetin and quercetin, and the content of Mn to be positively related to the amount of arabinose. The results implied that the P stresses severely disturbed the metabolism of minerals and metabolites in tea plants, which influenced the yield and quality of tea. Copyright © 2017. Published by Elsevier Masson SAS.

  17. System Wide Information Management (SWIM)

    NASA Technical Reports Server (NTRS)

    Hritz, Mike; McGowan, Shirley; Ramos, Cal

    2004-01-01

    This viewgraph presentation lists questions regarding the implementation of System Wide Information Management (SWIM). Some of the questions concern policy issues and strategies, technology issues and strategies, or transition issues and strategies.

  18. Air Force Geophysics Laboratory Management Information System Study.

    DTIC Science & Technology

    1985-11-01

    management information system (MIS) at AFGL. The study summarizes current management and administrative practices at AFGL. Requirements have been identified for automating several currently manual functions to compile accurate and timely information to better manage and plan AFGL programs. This document describes the functions and relative priorities of five MIS subsystems and provides suggestions for implementation solutions. Creation of a detailed Development Plan is recommended as the follow-on task.

  19. INCEPTION, DESIGN AND IMPLEMENTATION OF A MANAGEMENT INFORMATION SYSTEM.

    DTIC Science & Technology

    The purpose of this paper is to develop a uniform systematic approach to the design and implementation of a management information system . In recent...directed towards the design of a management information system . To this end - the creaction of such a document - is this paper dedicated. The...inception to successful implementation of a management information system . Many factors must be considered while applying this procedure, e.g., complexity

  20. Developing a Management Information System for the Chief of Supply.

    DTIC Science & Technology

    1985-09-01

    This study examined the information needs of the Chief of Supply in order to facilitate the development of a Management Information System (MIS...information items found to be available within the SBSS program, it was determined feasible to continue the development of this Management Information System . The...results of this study led to two recommendations. The first was to immediately implement a Management Information System for the Chief of

  1. 77 FR 56842 - Labor-Management Relations Information Collection Requests

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-14

    ... FEDERAL MEDIATION AND CONCILIATION SERVICE Labor-Management Relations Information Collection... the following public information collection request (ICR) to the Office of Management and Budget (OMB... information collection request is the Notice to Mediation Agencies (Agency Form F-7), OMB control number 3076...

  2. Case Studies of Ecological Integrative Information Systems: The Luquillo and Sevilleta Information Management Systems

    NASA Astrophysics Data System (ADS)

    San Gil, Inigo; White, Marshall; Melendez, Eda; Vanderbilt, Kristin

    The thirty-year-old United States Long Term Ecological Research Network has developed extensive metadata to document their scientific data. Standard and interoperable metadata is a core component of the data-driven analytical solutions developed by this research network Content management systems offer an affordable solution for rapid deployment of metadata centered information management systems. We developed a customized integrative metadata management system based on the Drupal content management system technology. Building on knowledge and experience with the Sevilleta and Luquillo Long Term Ecological Research sites, we successfully deployed the first two medium-scale customized prototypes. In this paper, we describe the vision behind our Drupal based information management instances, and list the features offered through these Drupal based systems. We also outline the plans to expand the information services offered through these metadata centered management systems. We will conclude with the growing list of participants deploying similar instances.

  3. Implementation of Hepatitis Information Management System in Iran.

    PubMed

    Reza, Safdari; Jebraeil, Farzi; Akbar, Nasiri Ali; Marjan, Ghazisaeedi; Reza, Taghavi Mohammad; Mehdi, Afshari; Mahlagha, Sargolzaee; Farhad, Taji

    2015-11-17

    Nowadays, hepatitis is of the most important health priorities around the world, where information plays a very significant role in specialized diseases prevention planning, and policy- and decision-making processes. Thus, this study addressed challenges of hepatitis information management and investigated the outcomes of establishing a hepatitis information management system to overcome such challenges. To this end, this research intended to study the implementation of an Electronic hepatitis information management system. This is an applied-developmental study with following specifications and procedures: preparation of study proposal and design, justification of the design's stakeholders, approval of the design by the Postgraduate Education Council of Faculty, determination of pilot hepatitis control center, software development, deciding on control, prevention, and treatment centers, and finally development of a network-based system for collecting and managing hepatitis information. Results indicated that the inconsistency and lack of integrity of data, as well as the lack of communication between related units prevented timely information register of viral hepatic patients and services that are provided to them. This inhibited the possibility of considering a follow-up process. However, the implementation of this system and involvement of relevant units greatly solved these problems. Results show that the implementation of an electronic system for the management of hepatitis control, prevention, and treatment is a regional and national requirement; since, this system with its empowered infrastructure is capable in providing desired services to all laboratories, counseling and health centers, specialized clinics, and physicians connected to the hepatitis network. This enables them to follow up and monitor patients' conditions. That mentioned system paves the way for the analysis of gathered information, managers' and specialists' access in different regions to

  4. Integrated information management and hospital libraries.

    PubMed Central

    Buchanan, H S; Fazzone, N

    1985-01-01

    It is demonstrated that hospitals are information-dependent and that there is need for integration of information generated and gathered through their subsystems. This paper discusses recommendations of the Matheson Report for an integrated information management system which would link these subsystems. The library's statement of mission, means for self-assessment, and analysis of information needs and uses are explored. Future directions with examples of new roles for the library are outlined. PMID:3978295

  5. Incentive Issues in Information Security Management

    ERIC Educational Resources Information Center

    Lee, Chul Ho

    2012-01-01

    This dissertation studies three incentive issues in information security management. The first essay studies contract issues between a firm that outsources security functions and a managed security service provider (MSSP) that provides security functions to the firm. Since MSSP and firms cannot observe each other's actions, both can suffer…

  6. Degree of conversion and hardness of two different systems of the Vitrebond™ glass ionomer cement light cured with blue LED.

    PubMed

    Calixto, Luiz Rafael; Tonetto, Mateus Rodrigues; Pinto, Shelon Cristina Souza; Barros, Erico Damasceno; Borges, Alvaro Henrique; Lima, Fabricio Viana Pereira; de Andrade, Marcelo Ferrarezi; Bandéca, Matheus Coelho

    2013-03-01

    This study investigated the physicochemical properties of the new formulation of the glass ionomer cements through hardness test and degree of conversion by infrared spectroscopy (FTIR). Forty specimens (n = 40) were made in a metallic mold (4 mm diameter x 2 mm thickness) with two resin-modified glass ionomer cements, Vitrebond™ and Vitrebond™ Plus (3M/ ESPE). Each specimen was light cured with blue LED with power density of 500 mW/cm(2) during 30 s. Immediately after light curing, 24h, 48h and 7 days the hardness and degree of conversion was determined. The Vickers hardness was performed by the MMT-3 microhardness tester using load of 50 gm force for 30 seconds. For degree of conversion, the specimens were pulverized, pressed with KBr and analyzed with FT-IR (Nexus 470). The statistical analysis of the data by ANOVA showed that the Vitrebond™ and Vitrebond™ Plus were no difference significant between the same storage times (p > 0.05). For degree of conversion, the Vitrebond™ and Vitrebond™ Plus were statistically different in all storage times after light curing. The Vitrebond™ showed higher values than Vitrebond™ Plus (p < 0.05). The performance of Vitrebond™ had greater results for degree of conversion than Vitrebond™ Plus. The correlation between hardness and degree of conversion was no evidence in this study.

  7. An architecture model for multiple disease management information systems.

    PubMed

    Chen, Lichin; Yu, Hui-Chu; Li, Hao-Chun; Wang, Yi-Van; Chen, Huang-Jen; Wang, I-Ching; Wang, Chiou-Shiang; Peng, Hui-Yu; Hsu, Yu-Ling; Chen, Chi-Huang; Chuang, Lee-Ming; Lee, Hung-Chang; Chung, Yufang; Lai, Feipei

    2013-04-01

    Disease management is a program which attempts to overcome the fragmentation of healthcare system and improve the quality of care. Many studies have proven the effectiveness of disease management. However, the case managers were spending the majority of time in documentation, coordinating the members of the care team. They need a tool to support them with daily practice and optimizing the inefficient workflow. Several discussions have indicated that information technology plays an important role in the era of disease management. Whereas applications have been developed, it is inefficient to develop information system for each disease management program individually. The aim of this research is to support the work of disease management, reform the inefficient workflow, and propose an architecture model that enhance on the reusability and time saving of information system development. The proposed architecture model had been successfully implemented into two disease management information system, and the result was evaluated through reusability analysis, time consumed analysis, pre- and post-implement workflow analysis, and user questionnaire survey. The reusability of the proposed model was high, less than half of the time was consumed, and the workflow had been improved. The overall user aspect is positive. The supportiveness during daily workflow is high. The system empowers the case managers with better information and leads to better decision making.

  8. Information systems in food safety management.

    PubMed

    McMeekin, T A; Baranyi, J; Bowman, J; Dalgaard, P; Kirk, M; Ross, T; Schmid, S; Zwietering, M H

    2006-12-01

    Information systems are concerned with data capture, storage, analysis and retrieval. In the context of food safety management they are vital to assist decision making in a short time frame, potentially allowing decisions to be made and practices to be actioned in real time. Databases with information on microorganisms pertinent to the identification of foodborne pathogens, response of microbial populations to the environment and characteristics of foods and processing conditions are the cornerstone of food safety management systems. Such databases find application in: Identifying pathogens in food at the genus or species level using applied systematics in automated ways. Identifying pathogens below the species level by molecular subtyping, an approach successfully applied in epidemiological investigations of foodborne disease and the basis for national surveillance programs. Predictive modelling software, such as the Pathogen Modeling Program and Growth Predictor (that took over the main functions of Food Micromodel) the raw data of which were combined as the genesis of an international web based searchable database (ComBase). Expert systems combining databases on microbial characteristics, food composition and processing information with the resulting "pattern match" indicating problems that may arise from changes in product formulation or processing conditions. Computer software packages to aid the practical application of HACCP and risk assessment and decision trees to bring logical sequences to establishing and modifying food safety management practices. In addition there are many other uses of information systems that benefit food safety more globally, including: Rapid dissemination of information on foodborne disease outbreaks via websites or list servers carrying commentary from many sources, including the press and interest groups, on the reasons for and consequences of foodborne disease incidents. Active surveillance networks allowing rapid dissemination

  9. Business Management in the advanced information society

    NASA Astrophysics Data System (ADS)

    Saeki, Akio

    This is a record of the commemorative lecture at the fifth anniversary of the establishment of the JICST Tohoku Branch Office. Lecturer explains about business management in the information age. "Management" originally means sensing and coping with changes. Thus, the business has to get information as quickly as possible and take the best possible measure for the new issues. As it is definitely important for the business to make an appropriate prediction, information including unknown facts is very valuable. Technological prediction is particulary indispensable for the business. It is available, to some extent, by looking back the steps of technological development in the past. As the characteristics of information age, lecturer explains that there will be less information gap in the world, due to the development of telecommunication technology.

  10. Science information for informing forest fuel management in dry forests of the western United States

    Treesearch

    Sarah McCaffrey; Russell Graham

    2007-01-01

    Land managers need timely and straightforward access to the best scientific information available for informing decisions on how to treat forest fuels in the dry forests of the western United States. However, although there is a tremendous amount of information available for informing fuels management decisions, often, it is in a form that is difficult to use or of...

  11. 76 FR 18220 - Labor-Management Cooperation Grant Program Information Collection Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-01

    ... FEDERAL MEDIATION AND CONCILIATION SERVICE Labor-Management Cooperation Grant Program Information... submission of the following public information collection request (ICR) to the Office of Management and...-13). This information collection, ``Labor-Management Cooperation Grant Program Information Collection...

  12. Smart Information Management in Health Big Data.

    PubMed

    Muteba A, Eustache

    2017-01-01

    The smart information management system (SIMS) is concerned with the organization of anonymous patient records in a big data and their extraction in order to provide needful real-time intelligence. The purpose of the present study is to highlight the design and the implementation of the smart information management system. We emphasis, in one hand, the organization of a big data in flat file in simulation of nosql database, and in the other hand, the extraction of information based on lookup table and cache mechanism. The SIMS in the health big data aims the identification of new therapies and approaches to delivering care.

  13. Environmental Scanning: Acquisition and Use of Information by Managers.

    ERIC Educational Resources Information Center

    Choo, Chun Wei; Auster, Ethel

    1993-01-01

    Defines environmental scanning as the acquisition and use of information about an organization's external environment to assist managers in planning. Highlights include a historical review; organizational theories; information needs and uses; managers as information users; and a review of research on environmental scanning. (Contains 124…

  14. Records & Information Management Services | Alaska State Archives

    Science.gov Websites

    Search Search in: Archives State of Alaska Home About Records Management (RIMS) For Researchers Collections Imaging (IMS) ASHRAB Libraries, Archives, & Museums Archives Records Management (RIMS) Records records and information management for the State of Alaska. Frequently Asked Questions Submit Records

  15. Information gathering, management and transfering for geospacial intelligence

    NASA Astrophysics Data System (ADS)

    Nunes, Paulo; Correia, Anacleto; Teodoro, M. Filomena

    2017-07-01

    Information is a key subject in modern organization operations. The success of joint and combined operations with organizations partners depends on the accurate information and knowledge flow concerning the operations theatre: provision of resources, environment evolution, markets location, where and when an event occurred. As in the past and nowadays we cannot conceive modern operations without maps and geo-spatial information (GI). Information and knowledge management is fundamental to the success of organizational decisions in an uncertainty environment. The georeferenced information management is a process of knowledge management, it begins in the raw data and ends on generating knowledge. GI and intelligence systems allow us to integrate all other forms of intelligence and can be a main platform to process and display geo-spatial-time referenced events. Combining explicit knowledge with peoples know-how to generate a continuous learning cycle that supports real time decisions mitigates the influences of fog of everyday competition and provides the knowledge supremacy. Extending the preliminary analysis done in [1], this work applies the exploratory factor analysis to a questionnaire about the GI and intelligence management in an organization company allowing to identify future lines of action to improve information process sharing and exploration of all the potential of this important resource.

  16. Waste Management Information System (WMIS) User Guide

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    R. E. Broz

    2008-12-22

    This document provides the user of the Waste Management Information System (WMIS) instructions on how to use the WMIS software. WMIS allows users to initiate, track, and close waste packages. The modular design supports integration and utilization of data throuh the various stages of waste management. The phases of the waste management work process include generation, designation, packaging, container management, procurement, storage, treatment, transportation, and disposal.

  17. "Effect of nano-filled surface coating agent on fluoride release from conventional glass ionomer cement: an in vitro trial".

    PubMed

    Tiwari, S; Nandlal, B

    2013-01-01

    To overcome the drawbacks of glass ionomer cement of sensitivity to initial desiccation and moisture contamination the use of surface coating agent is recommended. The search in this area led to invent of use of nanofillers in surface coating agent, but its effect on fluoride release is not clear. The aim of this study is to evaluate and compare the fluoride release from conventional glass ionomer cement with and without surface coating agent. This in vitro study comprised of total 80 samples (40 samples of each with and without surface coating). Specimens were prepared, G coat plus was applied and light cured. Fluoride release of the sample was measured every 24 h for 7 days and weekly from 7th to 21 st day using Sension4 pH/ISE/MV Meter. Descriptive Statistics, Repeated Measure ANOVA, Paired Sample t-test, Independent Sample t-test, Scheffe post hoc test. Mean values clearly reveal a significant decrease in the fluoride release from day 1 to day 21 for both groups. Non-coated group released significantly more fluoride than surface coated group (P<0.001). It can be concluded that nanofilled surface coating agent will reduce the amount of fluoride released into oral environment as compared to non-coated group and at the same time releasing fluoride into surrounding cavity walls to create zones of inhibition into the cavity floor to help internal remineralization.

  18. USAREUR LOGISTIC MANAGEMENT INFORMATION SYSTEM - 360 DAY BRIEFING.

    DTIC Science & Technology

    Information System . This report is the 360 Day Briefing presented to the DCSLOG and his Logistic Management Information System Committee at the conclusion of the study. (Author)...objective of the study was to provide for the Deputy Chief of Staff for Logistics, Headquarters USAREUR and Seventh Army, a Logistic Management

  19. [How management teams use information and control systems to manage hospitals].

    PubMed

    Naranjo-Gil, David

    2016-01-01

    To analyze the relationship between the characteristics of top management teams and the different use of management information and control systems (MICS) to implement policies that encourage cooperation and activity coordination in public hospitals. Data were collected through a questionnaire sent to each member of the top management teams of 231 Spanish public hospitals (chief executive director, medical director, nursing director and director for financial and social issues). A total of 457 valid questionnaires were returned, composing 86 full top management teams (37.23%). Top management team diversity was positively related to the interactive use of MICS. Management teams composed of younger members and members with longer service used MICS interactively. Top management teams with a predominantly clinical education and experience used MICS interactively, while top teams with a predominantly administrative education and experience used MICS diagnostically. The results also showed that cooperation and coordination in hospitals were positively related to the interactive use of MICS and were negatively related to the diagnostic use of MICS. The interactive use of MICS is an important mediator in the relationship between top team diversity and policies focused on hospital decentralization. Top management teams with diverse characteristics (e.g. age, length of service, education and experience) use management information interactively to enhance activity coordination and resource allocation in hospitals. Copyright © 2016 SESPAS. Published by Elsevier Espana. All rights reserved.

  20. Region 7 Laboratory Information Management System

    EPA Pesticide Factsheets

    This is metadata documentation for the Region 7 Laboratory Information Management System (R7LIMS) which maintains records for the Regional Laboratory. Any Laboratory analytical work performed is stored in this system which replaces LIMS-Lite, and before that LAST. The EPA and its contractors may use this database. The Office of Policy & Management (PLMG) Division at EPA Region 7 is the primary managing entity; contractors can access this database but it is not accessible to the public.