27 research outputs found

    Direct Pulp Capping Effect with Experimentally Developed Adhesive Resin Systems Containing Reparative Dentin Promoting Agents on Rat Pulp -Mixed Amounts of Additives and Their Effect on Wound Healing-

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    This study examined the wound healing process of exposed rat pulp when treated with experimental adhesive resin systems. The experimental direct pulp capping adhesive resin systems were composed of primer-I, primer-II and an experimental bonding agent. Primer-I was Clearfil SE Bond (CSE) primer containing 1.0 or 5.0wt% CaCl2, and primer-II was CSE primer containing 0.1, 1.0 or 5.0wt% compound of equal mole of pA and pB with synthetic peptides derived from dentin-matrix-protein 1 (DMP1). Primer-I containing 1.0wt% and 5.0wt% CaCl2 were assigned to the experimental groups 1 to 3, and 4 to 6, respectively. Primer-II containing 0.1, 1.0 or 5.0wt% compound of pA and pB were assigned to the experimental groups 1 and 4, 2 and 5, and 3 and 6, respectively. In all experimental groups, CSE bond containing 10wt% hydroxyapatite powder was used as the experimental bonding agent. The positive control teeth were capped with calcium hydroxide preparation (Dycal), and the negative control teeth were capped with CSE. The specimens were alternately stained with Mayer's H&E and the enhanced polymer one-step staining method. Experimental groups 1, 4, 5 and 6 showed a higher level of reparative dentin formation compared to the negative control 14 days postoperatively. At 28 days postoperatively, all experimental groups showed the formation of extensive reparative dentin, and experimental groups 4, 5 and 6 demonstrated similar dentin bridge formation as that of the positive control. How quickly reparative dentin formation occurs might depend on the concentration of CaCl2 and pA and pB in the experimental primer

    An eccentric calpain, CAPN3/p94/calpain-3

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    AbstractCalpains are Ca2+-regulated proteolytic enzymes that are involved in a variety of biological phenomena. Calpains process substrates by limited proteolysis to modulate various protein functions in the cell, and are thus called “modulator proteases.” CAPN3, previously called p94 or calpain-3, has unique features that are not found in any of the other 14 human calpains, or even in other proteases.For instance, CAPN3 undergoes extremely rapid and exhaustive autodegradation. CAPN3 is also the first (and so far, the only) intracellular enzyme found to depend on Na+ for its activation. CAPN3 has both proteolytic and non-proteolytic functions. It has the interesting distinction of being the only protease, other than a few virus proteases, with the ability to regain protease function after its autolytic dissociation; this occurs through a process known as intermolecular complementation (iMOC). Gene mutations causing CAPN3 defects are responsible for limb-girdle muscular dystrophy type 2A (LGMD2A).Unusual characteristics of CAPN3 have fascinated researchers, but have also hampered conventional biochemical analysis. In this review, we describe significant findings about CAPN3 from its discovery to the present, and suggest promising avenues for future CAPN3 research

    Shear bond strength of rebonded brackets after removal of adhesives with Er,Cr:YSGG laser

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    This study was conducted to examine the bond strength of rebonded orthodontic brackets after adhesive residuals on the surface of the bracket bases were removed by Er,Cr:YSGG lasers. Seventy-six brackets bonded to premolars with a self-etching primer adhesive system were equally divided into four groups after the first debonding with the bracket bases (Group 1) untreated, and treated by (Group 2) Er,Cr:YSGG laser, (Group 3) sandblaster, and (Group 4) Er,Cr:YSGG laser/sandblaster. The treated brackets were rebonded to the new premolars in the same manner as the first-stage experiment. The shear bond strengths were measured, with the bonding/debonding procedures repeated once after the first debonding, and the bracket/adhesive failure modes were evaluated after each debonding. The treated bracket base surfaces were observed under a scanning electron microscopy (SEM). The mean rebond strengths were significantly lower in group 1 than in other groups, and that there were no significant differences between the other groups. The mean initial bond strength was significantly higher than the mean rebond strength in group 1 but there was no significant difference between the two in the other three groups. Failures at the bracket-adhesive interface occurred frequently at second debonding in group 1. Under the SEM, residual adhesive was removed from the bracket bases by Er,Cr:YSGG laser, while adhesive remnant was seen underneath the meshwork of the bracket bases and microroughness appeared on the meshwork after sandblasting. Er,Cr:YSGG laser certainly could serve the purpose of promoting the use of recycled orthodontic brackets

    Results of the search for inspiraling compact star binaries from TAMA300's observation in 2000-2004

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    We analyze the data of TAMA300 detector to search for gravitational waves from inspiraling compact star binaries with masses of the component stars in the range 1-3Msolar. In this analysis, 2705 hours of data, taken during the years 2000-2004, are used for the event search. We combine the results of different observation runs, and obtained a single upper limit on the rate of the coalescence of compact binaries in our Galaxy of 20 per year at a 90% confidence level. In this upper limit, the effect of various systematic errors such like the uncertainty of the background estimation and the calibration of the detector's sensitivity are included.Comment: 8 pages, 4 Postscript figures, uses revtex4.sty The author list was correcte

    Observation results by the TAMA300 detector on gravitational wave bursts from stellar-core collapses

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    We present data-analysis schemes and results of observations with the TAMA300 gravitational-wave detector, targeting burst signals from stellar-core collapse events. In analyses for burst gravitational waves, the detection and fake-reduction schemes are different from well-investigated ones for a chirp-wave analysis, because precise waveform templates are not available. We used an excess-power filter for the extraction of gravitational-wave candidates, and developed two methods for the reduction of fake events caused by non-stationary noises of the detector. These analysis schemes were applied to real data from the TAMA300 interferometric gravitational wave detector. As a result, fake events were reduced by a factor of about 1000 in the best cases. The resultant event candidates were interpreted from an astronomical viewpoint. We set an upper limit of 2.2x10^3 events/sec on the burst gravitational-wave event rate in our Galaxy with a confidence level of 90%. This work sets a milestone and prospects on the search for burst gravitational waves, by establishing an analysis scheme for the observation data from an interferometric gravitational wave detector

    Evaluation of Restorative Techniques for Vertically Fractured Roots

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    The purpose of this study was to examine the effects of combining specific adhesive materials and various surface treatments on bonding durability and microleakage of vertically fractured roots. Adhesive models were prepared using bovine lower incisors. The experiment included the following five groups: SB-G group (control) (10% citric acid with 3% ferric chloride solution (10-3 solution) + an adhesive resin cement (4-META/MMA-TBB; Super-Bond®)), EC group (self-cure bonding agent (UB) + core composite resin (EC)), EC-G group (10-3 solution + UB + EC), EC-P group (40% phosphate solution + UB + EC), and EC-E group (18% ethylenediaminetetraacetic acid (EDTA) solution + UB + EC). After applying a load of 50,000 cycles, microleakage, microtensile bond strength (μTBS), and failure modes were examined. Microleakage of the EC, EC-G, and EC-E groups was significantly lower than that of the EC-P group. The μTBS of the EC-G group was significantly higher than that of the other groups. All EC groups showed that mixed (cohesive and adhesive) and adhesive failures were the most prevalent types of failure modes. The EC-G group showed the highest bonding durability and the lowest microleakage results, which indicates a possible alternative to current adhesive and tooth surface treatments

    Corrosion of an aluminum alloy chilled in flowing seawater and the effect of cathodic prevention

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    A new type of jet-in-slit testing apparatus for a specimen, chilled with a peltier element, was developed to investigate corrosion on the heat transfer surface of an aluminum alloy heat exchanger, in contact with a liquefaction gas at cryogenic temperature and in flowing seawater. The specimen can be chilled, even under flowing conditions, using this apparatus. Corrosion tests and polarization measurements of a specimen chilled by a peltier element were carried out in flowing seawater at various temperatures. The effect of chilling a specimen was equivalent to the effect achieved for a test in solution at a lower temperature. The process was dependent on a passive film, formed on the surface of the aluminum alloy specimen, as evidenced by polarization measurements. The extent of corrosion damage increased with increasing temperature of the solution, and showed maximum damage at high temperature. At high temperatures, erosion-corrosion was found at the central part of the specimen, but the effect of flow was negligible at low temperature. Corrosion tests for a cathodically polarized specimen were conducted under flowing conditions. Corrosion damage was accelerated by cathodic polarization at lower temperatures
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