We investigated the current status of institutional review boards (IRBs) that oversee research in dental hospitals. Eight hospitals, all of which had IRB, responded to our e-mail. The questions comprised two topics: IRBs and the clinical trials approved by them. The results showed that the average number of staff on IRBs of the 8 hospitals was 12.5. Furthermore, the proportion of dentists was the highest among the science committee members, with an average of 7.75, and the average number of non-dentists among the non-scientific members was 1.8. Regular IRBs convened meetings more than once a month, over the past year, or only if necessary.According to the approval status of clinical trials from 2016 to 2019, less than 50 studies accounted for 75%. The materials related to dental-implant procedures accounted for the highest quantity of materials used during clinical trials at 33.3%. The duration of 50% of the clinical trials ranged from more than 1 year to less than 2 years.Thus, based on the hypothesis that institutional reviews are currently conducted at dental hospitals and have raised issues and suggested improvements, we believe that IRBs will play an important role in dental hospitals, with more research conducted in dentistry in the future.

This study examines the relationship between R&D intensity and disclosure. R&D activities are essential in bringing innovation to companies. However, R&D activities are naturally uncertain and increase information asymmetry. Thus, firms with high R&D activities are more likely to have the incentive to communicate the potential of R&D investment to the market through voluntary disclosure and, concurrently, resolve information asymmetry. Meanwhile, incentives to less voluntary disclosure exist because of the proprietary cost and the risk of competitiveness loss. Furthermore, the uncertainties inherent in R&D activities caused the possible decrease in the information accuracy. For the two opposing views, this study investigates the relationship between R&D intensity and disclosure frequency using the Regulation Fair Disclosure data in Korea. Moreover, the relationship between R&D intensity and usefulness of the information disclosed is also examined. Using firm sample listed in the 2011–2016 Korea Stock Market, results show that firms with high R&D intensity make disclosures more frequent. Subsequently, the analysis using forecast sample shows that management forecast error is higher in firms with high R&D intensity. This research contributes to the existing literature by presenting evidence that R&D intensity is a significant factor affecting manager's disclosure behavior and information usefulness.

This study was performed to investigate the nutritional conditions controlling keratinase activity in Bacillus megaterium F7-1. B. megaterium F7-1 produced keratinase using chicken feather as a sole source of carbon, nitrogen and sulfur. Addition of the feather medium with glucose enhanced keratinase production (68.9 U/ml), compared to control without glucose (63.2 U/ml). The synthesis of keratinase was repressed by addition of NH4Cl in B. megaterium F7-1. The highest keratinase production (70.9 U/ml) was obtained with the feather medium containing glucose and MgSO4·7H2O. Keratinase was produced in the absence of feather (4.9 U/ml), indicating its constitutive synthesis. Feather degradation resulted in free SH group formation. B. megaterium F7-1 effectively degraded chicken feather meal (86%), whereas duck feather, human nail, human hair and sheep wool displayed relatively low degradation rates (8-34%).