Result of the Threshold Test for Saltiness Perception of 35 People who Participated in the Saltiness Test using Test-Disk at the University Festival

Hypertension is one of the causes of many lifestyle-related diseases. In Japan, too, we are raising awareness about dietary salt reduction for hypertensive patients. Therefore, the purpose of this study was to understand the results of the salty cognitive threshold test in a wide range of age. This result can be useful data for future salt reduction instruction. Thirty-five people participated in the saltiness cognition threshold test at the university festival. The participants this time had a wide range of ages from the teens to the eighties. Participants answered that they eat out 2-3 times a week. Also, they said that the seasoning they like to eat is a little salty. Most participants (88.6%) perceived saltiness below 1.25%. Four participants (one male and three females) recognized saltiness in 5.0%. There was no participant didn’t recognize the saltiness of all. In the future, it will be better to conduct a questionnaire survey on dietary habits and compare it with the saltiness cognitive threshold test results.

Formulation and characterization of antibacterial orthodontic adhesive

ABSTRACT Objective: The objective of this study was to formulate experimental orthodontic bracket adhesives and test their mechanical properties, fluoride release and antibacterial activity. Methods: Four experimental antibacterial orthodontic bracket adhesives were prepared with different compositions of synthesized antibacterial monomers replacing total 5% of dental monomers in the control Transbond XT (3M): 5%C11, 3.5%C11+1.5%C2, 5%C16, and 3.5%C16+1.5%C2. Transbond XT alone was used as control. These groups were used to bond premolar brackets to extracted premolars. Shear bond strength (SBS) was tested using an Instron machine. For antibacterial test, disk specimens (10mm diameter, 1mm thick, n=4) were fabricated and incubated with cultures of cariogenic Streptococcus mutans for 48h, and following gentle sonication, S. mutans biofilms in colony-forming-units (CFU) on the disks were enumerated by plating on agar medium. The data were analyzed using ANOVA and Tukey test (α=0.05). Results: All experimental groups had similar shear bond strength (no significant difference) to the control. All experimental groups showed significant inhibitory effect against S. mutans biofilm formation, when compared to the control, but there was no significant difference between experimental groups. Conclusion: Antibacterial orthodontic adhesive can be fabricated to have similar mechanical properties but better caries-inhibitory effect than current adhesive.

Pengaruh Temperatur dan Waktu Etching Terhadap Karakeristik Fisik dan Mekanik Pelapisan Nikel pada Plastik ABS dengan Metode Elektrolessplating

ABS Plastic (Acrylonitrile Butadiene Stiren) is one type of plastic that is often used because of the many properties that are beneficial to humans. ABS plastic is widely used in engineering, for example in the electronics and automotive fields. But there are still disadvantages of ABS plastic, including low hardness, no friction resistance, and no heat resistance, so surface treatment is needed. Electrolessplating is a coating process that does not use electricity in the coating process. This study aims to determine the effect of temperature and time variation of nickel electrolessplating etching on roughness, wear, hardness, and thickness. The variation in etching temperature is 30; 40; 50; 60; and 70oC and the etching time is 15, 20, 25, 30 and 35 minutes followed by electrolesplating using nickel for 10 minutes. The tests carried out were surface roughness test, disk on block method wear test, hardness using Shore Durometer tool, and layer thickness using micro photos and scanning electron microscopy (SEM). The results showed that the etching process from electrolyplating affected the specimen surface to be coated with nickel metal. The longer the etching time causes the surface to become coarser from 0.435 μm at 15 minutes to 0.949 μm in 35 minutes. The temperature addition of the etching process will increase the surface surface to a temperature of 50oC at 0.499 μm and then drop. Increasing etching time from 15 minutes to 35 minutes will reduce specific wear, from 1.268 x 10-4 mm2 / kg to 0.465 x 10-4 mm2 / kg. Likewise, the etching temperature from 30oC to 70oC decreases the specific wear from 2.10 x 10-4 mm2 / kg to 0.255 x 10-4 mm2 / kg. The addition of etching and temperature etching time does not significantly increase the hardness value of electrolessplating results. Hardness of raw material is 83.5 shore D after coating the hardness value to 84.7 shore D. The electrolessplating process for 10 minutes produces a layer thickness of 1 μm to 2 μm.

Strain-Life Assessment of Grainex Mar-M 247 for NASA’s Turbine Seal Test Facility

NASA’s turbine seal facility tests air-to-air seals for advanced jet engines. High temperature, speed, and pressure combinations limit test disk life, due to crack initiation in the Grainex Mar-M 247 disk bolt holes. An inspection interval is determined to ensure safe operation. Fatigue strain-life data is presented for test specimens from a test disk. Strain-life models (Manson-Hirschberg method of universal slopes, Halford-Nachtigall mean stress method, and modified Morrow method) were compared to experiment. Using experimental data at −99.95% prediction levels, accounting for six bolt holes at 0.5% total strain and 649°C, the test disk should be inspected after 665 cycles.

In Vitro Susceptibility Testing of Geotrichum capitatum: Comparison of the E-Test, Disk Diffusion, and Sensititre Colorimetric Methods with the NCCLS M27-A2 Broth Microdilution Reference Method

ABSTRACT The in vitro activities of amphotericin B, flucytosine, fluconazole, itraconazole, and voriconazole against 23 isolates of Geotrichum capitatum were determined by the National Committee for Clinical Laboratory Standards (NCCLS) M27-A2 microdilution method and the Sensititre and agar diffusion methods. Amphotericin B and voriconazole appeared to be the more active drugs. Sensititre showed the highest rates of agreement with the NCCLS M27-A2 method.

Infant Lightness Perception

When adults view a test disk embedded in a higher-luminance surround, the perceived lightness of the disk is largely determined by the surround-to-disk (S/D) luminance ratio (Wallach's ratio rule). Performance of 4-month-old infants tested with a forced-choice novelty-preference technique was consistent with predictions based on Wallach's ratio rule. This result suggests that the ability to extract and maintain information about local luminance ratios is present early in infancy. This ability is likely to contribute to the development of lightness constancy.