30 research outputs found
Multi-digit tactile perception I: motion integration benefits for tactile trajectories presented bimanually
Interactions with objects involve simultaneous contact with multiple, not necessarily adjacent, skin regions. While advances have been made in understanding the capacity to selectively attend to a single tactile element among distracting stimulations, here, we examine how multiple stimulus elements are explicitly integrated into an overall tactile percept. Across four experiments, participants averaged the direction of two simultaneous tactile motion trajectories of varying discrepancy delivered to different fingerpads. Averaging performance differed between within- and between-hands conditions in terms of sensitivity and precision but was unaffected by somatotopic proximity between stimulated fingers. First, precision was greater in between-hand compared to within-hand conditions, demonstrating a bimanual perceptual advantage in multi-touch integration. Second, sensitivity to the average direction was influenced by the discrepancy between individual motion signals, but only for within-hand conditions. Overall, our experiments identify key factors that influence perception of simultaneous tactile events. In particular, we show that multi-touch integration is constrained by hand-specific rather than digit-specific mechanisms
Inhibitory Effect of Polypodium Leucotomos Extract on Cytochrome P450 3A-mediated Midazolam Metabolism
Polypodium leucotomos(PL)is a fern native to Latin America, and its extract is used as an oral sunscreen; however, its safety during use has not been adequately investigated. Therefore, the aim of this study was to evaluate food-drug interactions associated with PL extract mediated by cytochrome P450 3A(CYP3A)inhibition and induction. Inhibition of CYP3A-mediated midazolam(MDZ)1’-hydroxylation activity by PL extract and its major phenolic components was evaluated in vitro using pooled human liver microsomes. In addition, MDZ pharmacokinetics were investigated in rats after a single dose, as well as after 1 week treatment with PL extract(30mg/kg)in order to evaluate the inhibitory and inducible effects of PL on CYP3A in vivo, respectively. Serum MDZ concentrations were analyzed and pharmacokinetic parameters were compared between PL- and water(control)-treated groups. In vitro, PL extract decreased MDZ 1’-hydroxylation activity in a concentration-dependent manner. However, the major phenolic compounds in PL extracts, namely caffeic, chlorogenic, p-coumaric, ferulic, and vanillic acids, did not exhibit any marked inhibitory effects on MDZ 1’-hydroxylation activity. In vivo, administration of a single dose of PL extract to rats significantly increased the area under the serum concentration-time curve from time 0 to infinity(AUC0–∞)and the maximum serum concentration(Cmax)of MDZ(by 57% and 88%, respectively; P<0.05). In contrast, there were no significant changes in MDZ pharmacokinetic parameters after 1 week of treatment with PL extract. These results suggest that PL extract can cause a food-drug interaction by inhibiting CYP3A
Long-term color stability of light-polymerized resin luting agents in different beverages
PurposeThe purpose of this study was to evaluate the long-term color stability of light-polymerized resin luting agents stored in different beverages.MethodsEleven shades of two light-polymerized resin luting agents, Choice2 (A1, A2, B1, TRANSLUCENT, MILKY OPAQUE, and MILKY BRIGHT) and BeautiCem Veneer (H-Value, M-Value, L-Value, Ivory-D, Ivory-L) were selected in this study. Disk-shaped specimens were fabricated with 1.3 mm thickness and 15.0 mm diameter. A total of 198 specimens, 18 for each shade, were prepared and randomly divided into six storage conditions (purified water, coffee, cola, tea, red wine, and air). All shades of specimens were three times measured at three random locations (n = 9) at 24 h storage in air after specimen preparation and then measured after immersion at 1, 3, 6, 9, and 12 mos. using a colorimeter. Then, the color difference (ΔE) between the specimens at 24 h after preparation and after storage in each liquid for 12 mos. was calculated. Statistical analysis was performed using Steele–Dwass multiple comparison test of the ΔE values or one-way ANOVA and Tukey's honest significant difference test.ResultsFor all immersion conditions, ΔE was significantly higher than air (control). The ΔE of the shades in the various storage conditions showed no significant difference between Purified Water-Cola and Coffee-Tea. Comparisons of the color components L*, a*, and b* for each shade showed different behaviors among the shades.ConclusionsThe results suggest that the color stability of light-polymerized resin luting agents may differ between different shades and beverages.</p
Rab27a mediates the tight docking of insulin granules onto the plasma membrane during glucose stimulation
Effect of Interpenetrating Polymer Network (IPN) Thermoplastic Resin on Flexural Strength of Fibre-Reinforced Composite and the Penetration of Bonding Resin into Semi-IPN FRC Post
The purpose of this study was to evaluate the effects of interpenetrating polymer network (IPN) thermoplastic resin on the flexural strength of fibre-reinforced composite (FRC) with different IPN polymer compositions. The penetration of bonding resin into semi-IPN FRC posts was also evaluated. The IPN thermoplastic resin used was UDMA-MMA monomer with either PMMA (0.5%, 2%, 5%) or PMMA-copolymer (0.5%, 2%). A no added IPN polymer resin was also made. Mixed resin was impregnated to S- and E-glass fibre rovings. These resins and resin impregnated fibres were used for flexural strength (FS) test. To evaluate the penetration of bonding resin into semi-IPN post, SEM observation was done with various impregnation time and polymerization mehods (hand-light- and oven-cure). The result of FS was recorded from 111.7 MPa (no-IPN polymer/no-fibre-reinforcement) to 543.0 MPa (5% PMMA/S-glass FRC). ANOVA showed that there were significant differences between fibre-reinforcement and no-fibre-reinforcement (p < 0.01) both in S- and E-glass fibre groups, and between 0.5% PMMA and 5% PMMA in the S-glass FRC group. SEM micrographs showed that the penetration layers of bonding resin into hand-light cured semi-IPN posts were different according to impregnation time. Fibre reinforcement is effective to improve flexural strength. The depth of penetration layer of bonding resin into semi-IPN matrix resin was improved when a hand-light cure was used
New diagnostic criteria and severity assessment of acute cholangitis in revised Tokyo guidelines
Background: The Tokyo Guidelines for the management of acute cholangitis and cholecystitis were published in 2007 (TG07) and have been widely cited in the world literature. Because of new information that has been published since 2007, we organized the Tokyo Guidelines Revision Committee to conduct a multicenter analysis to develop the updated Tokyo Guidelines (TG13). Methods/materials : We retrospectively analyzed 1,432 biliary disease cases where acute cholangitis was suspected. The cases were collected from multiple tertiary care centers in Japan. The 'gold standard' for acute cholangitis in this study was that one of the three following conditions was present: (1) purulent bile was observed; (2) clinical remission following bile duct drainage; or (3) remission was achieved by antibacterial therapy alone, in patients in whom the only site of infection was the biliary tree. Comparisons were made for the validity of each diagnostic criterion among TG13, TG07 and Charcot's triad. Results: The major changes in diagnostic criteria of TG07 were re-arrangement of the diagnostic items and exclusion of abdominal pain from the diagnostic list. The sensitivity improved from 82.8 % (TG07) to 91.8 % (TG13). While the specificity was similar to TG07, the false positive rate in cases of acute cholecystitis was reduced from 15.5 to 5.9 %. The sensitivity of Charcot's triad was only 26.4 % but the specificity was 95.6 %. However, the false positive rate in cases of acute cholecystitis was 11.9 % and not negligible. As for severity grading, Grade II (moderate) acute cholangitis is defined as being associated with any two of the significant prognostic factors which were derived from evidence presented recently in the literature. The factors chosen allow severity assessment to be performed soon after diagnosis of acute cholangitis. Conclusion: TG13 present a new standard for the diagnosis, severity grading, and management of acute cholangitis. © 2012 The Author(s).link_to_subscribed_fulltex
New diagnostic criteria and severity assessment of acute cholecystitis in revised Tokyo guidelines
Background: The Tokyo Guidelines for the management of acute cholangitis and cholecystitis (TG07) were published in 2007 as the world's first guidelines for acute cholangitis and cholecystitis. The diagnostic criteria and severity assessment of acute cholecystitis have since been widely used all over the world. A validation study of TG07 has shown that the diagnostic criteria for acute cholecystitis are highly reliable but that the definition of definite diagnosis is ambiguous. In addition, considerable new evidence referring to acute cholecystitis as well as evaluations of TG07 have been published. Consequently, we organized the Tokyo Guidelines Revision Committee to evaluate TG07, recognize new evidence, and conduct a multi-center analysis to revise the guidelines (TG13). Methods and materials: We retrospectively analyzed 451 patients with acute cholecystitis from multiple tertiary care centers in Japan. All 451 patients were first evaluated using the criteria in TG07. The "gold standard" for acute cholecystitis in this study was a diagnosis by pathology. The validity of TG07 diagnostic criteria was investigated by comparing clinical with pathological diagnosis. Results: Of 451 patients evaluated, a total of 227 patients were given a diagnosis of acute cholecystitis by pathological examination (prevalence 50.3 %). TG07 criteria provided a definite diagnosis of acute cholecystitis in 224 patients. The sensitivity of TG07 diagnostic criteria for acute cholecystitis was 92.1 %, and the specificity was 93.3 %. Based on the preliminary results, new diagnostic criteria for acute cholecystitis were proposed. Using the new criteria, the sensitivity of definite diagnosis was 91.2 %, and the specificity was 96.9 %. The accuracy rate was improved from 92.7 to 94.0 %. In regard to severity grading among 227 patients, 111 patients were classified as Mild (Grade I), 104 as Moderate (Grade II), and 12 as Severe (Grade III). Conclusion: The proposed new diagnostic criteria achieved better performance than the diagnostic criteria in TG07. Therefore, the proposed criteria have been adopted as new diagnostic criteria for acute cholecystitis and are referred to as the 2013 Tokyo Guidelines (TG13). Regarding severity assessment, no new evidence was found to suggest that the criteria in TG07 needed major adjustment. As a result, TG07 severity assessment criteria have been adopted in TG13 with minor changes. © 2012 The Author(s).link_to_subscribed_fulltex
Effect of frame design on the fracture strength of a zirconia crown and porcelainfaced crown
In this study, we investigated the effect of frame design on the fracture strength of a zirconia crown and porcelain-faced crown, with the aim of clinically applying a zirconia crown fabricated using computer-aided design and manufacturing. The results showed that the fracture strengths were 645.9 MPa with Frame Design 1, 759.5 MPa with Frame Design 2, and 989.7 MPa with Frame Design 3, suggesting that the fracture strength improved depending upon the frame design. The above information suggests that it is necessary for the zirconia crown frame form to have an occlusal surface table where the crown design has a reduced outer diameter, instead of using the conventional form of covering the abutment tooth with a thickness of 0.5 mm. © 2019, Japanese Society for Dental Materials and Devices. All rights reserved.</p
Effect of Self‐adhesive Resin Cement and Tribochemical Treatment on Bond Strength to Zirconia
In vitro evaluation of the bonding durability of self-adhesive resin cement to titanium using highly accelerated life test
The purpose of this in vitro study was to evaluate the bonding durability of three self-adhesive resin cements to titanium using the Highly Accelerated Life Test (HALT). The following self-adhesive resin cements were used to bond pairs of titanium blocks together according to manufacturers' instructions: RelyX Unicem, Breeze, and Clearfl SA Luting. After storage in water at 37°C for 24 h, bonded specimens (n=15) immersed in 37°C water were subjected to cyclic shear load testing regimes of 20, 30, or 40 kg using a fatigue testing machine. Cyclic loading continued until failure occurred, and the number of cycles taken to reach failure was recorded. The bonding durability of a self-adhesive resin cement to titanium was largely infuenced by the weight of impact load. HALT showed that Clearfl SA Luting, which contained MDP monomer, yielded the highest median bonding lifetime to titanium.link_to_OA_fulltex