최근 국내외 화장품과 식품산업에서 다양하게 사용되어 지고 있는 콜라겐 단백질 제품은 점차 그 용도와 특성에 따라 보다 고도화, 기능화 되어 가고 있다. 피부 건강의 지표인 콜라겐은 다양한 용도로 개발되어 사용되고 있으 며, 콜라겐의 소비가 증가함에 따라 용도에 적합한 최적 화된 콜라겐 제품의 개발이 중요한 연구 분야이다. 특히 여러 기업과 연구기관들에 의해서 콜라겐의 흡수율을 높 이기 위한 다양한 노력이 이루어지고 있다. 따라서 본 연 구에서는 프란즈(Franz) 세포 시스템을 이용하여 국내에서 판매되는 다양한 분자량별 콜라겐 제품의 경피 및 구강 상피세포 투과성을 비교하였다. 그 결과, 피부 표피/진피 조직과 비교하여 구강점막 조직의 콜라겐 흡수율이 분자 량 500달톤과 1,000달톤의 경우 모두 통계적으로 유의하 게(각각 약 10배, 2배) 높은 것으로 확인되었다. 또한, 분 자량별 구강점막 조직 흡수율을 비교한 결과, 분자량 500 달톤의 콜라겐이 분자량 1,000달톤 제품에 비해 흡수율이 2-3배 증가함을 확인하였다. 분자량 500달톤의 경우 Cmax 와 AUCt 값이 가장 높게 나타났으며, 피부 표피/진피 세 포에 비해 구강점막세포 시험군의 모든 지표가 높은 것으 로 나타났다. 본 연구 결과는 피부 흡수보다는 구강 점막 세포를 통한 콜라겐의 흡수방법이 콜라겐 체내 흡수증가 에 유효한 수단임을 시사하며, 분자량 1,000달톤 이하에서 도 보다 더 작은 500달톤의 저분자 콜라겐의 흡수율이 증 가되는 것으로 보아 콜라겐의 분자량이 흡수율 증가의 주 요한 요소임을 확인할 수 있었다.

In this study, crystallization was effectively suppressed in Al-based metallic glasses (Al-MGs) during pulverization by cryo-milling by applying an extremely low processing temperature and using a surfactant. Before Al-MGs can be used as an additive in Ag paste for solar cells, the particle sizes of the Al-MGs must be reduced by milling. However, during the ball milling process crystallization of the Al-MG is a problem. Once the Al-MG is crystallized, they no longer exhibit glass-like behavior, such as thermoplastic deformation, which is critical to decrease the electrical resistance of the Ag electrode. The main reason for crystallization during the ball milling process is the heat generated by collisions between the particles and the balls, or between the particles. Once the heat reaches the crystallization temperature of the Al-MGs, they start crystallization. Another reason for the crystallization is agglomeration of the particles. If the initially fed particles become severely agglomerated, they coalesce instead of being pulverized during the milling. The coalesced particles experience more collisions and finally crystallize. In this study, the heat generated during milling was suppressed by using cryo-milling with liquid-nitrogen, which was regularly fed into the milling jar. Also, the MG powders were dispersed using a surfactant before milling, so that the problem of agglomeration was resolved. Cryo-milling with the surfactant led to D50 = 10 um after 6 h milling, and we finally achieved a specific contact resistance of 0.22 mΩcm2 and electrical resistivity of 2.81 μΩcm using the milled MG particles.

PURPOSES :This study deals with traffic accidents involving trucks. The objective of this study is to develop a traffic accident model for trucks at roundabouts.METHODS :To achieve its objective, this study gives particular attention to develop appropriate models using Poisson and negative binomial regression models. Traffic accident data from 2007 to 2014 were collected from TAAS data set of road traffic authority. Thirteen explanatory variables such as geometry and traffic volume were used.RESULTS :The main results can be summarized as follows: (1) two statistically significant Poisson models (ρ2 = 0.398 and 0.435) were developed, and (2) the analysis revealed the common variables to be traffic volume, number of exit lanes, speed breakers, and truck apron width.CONCLUSIONS :Our modeling reveals that increasing the number of speed breakers and speed limit signs, and widening the truck apron width are important for reducing the number of truck accidents at roundabouts.

A new standard rose cultivar ‘Pink Stone’ was bred from the cross between red standard cultivar ‘Red Queen’ and pink standard cultivar ‘Vivaldi’ at the National Horticulture Research Institute. The cross was made in 2001 and ‘Pink Stone’ was finally selected in 2006 after investigating characteristics for three years from 2003 to 2006. ‘Pink Stone’, a deep pink standard cultivar grows vigorously and has powder mildew resistant. The major characteristics of this cultivar are 115.1 stems/m2/year in yield, 77.7 cm in length of cut flower, 10.5 cm in flower diameter, 67.0 in petal number, and 12.0 days in vase life. This cultivar can be propagated by both cutting and grafting. The consumer’s preference of this cultivar is relatively higher than that of control cultivar, ‘Noblesse’.