PURPOSES : Almost every design method for airport concrete pavements considers only traffic loading and not environmental loading. This study proposes a mechanistic design method for airport concrete pavements, that considers both environmental and traffic loading simultaneously. METHODS: First, the environmental loading of concrete pavements in Korean airports was quantified. FEAFAA, a finite element analysis program for airport pavements, was used to calculate the maximum tensile stress (MTS) of the slab, caused by both environmental and traffic loadings. The factors that influence the MTS were identified via sensitivity analysis, and an MTS prediction model was developed using the statistical analysis program SPSS. The ratio of MTS to the tensile strength of slab was calculated using the prediction model. The fatigue model under the AC 150/5320-6E and AC 150/5320-6F standards of the FAA was corrected to make it suitable for the predicted stress-strength ratio. RESULTS : The MTS prediction model and corrected fatigue model were used to redesign the slab thickness and joint spacing of airport concrete pavements originally designed using the AC 150/5320-6D standard, which empirically considers traffic loading only. As a result, different slab thicknesses and joint spacings were redesigned with consideration for environmental loading, specifically the weather conditions of airports. . CONCLUSIONS: The slab thickness and joint spacing can be mechanistically designed at the same time, whereas previously, only the slab thickness was designed, and the joint spacing was determined empirically.

The elderly suffer from an impaired immune function being obvious in a higher susceptibility to infections. Although the inflammatory cells are the major immunomodulatory cells, fibroblasts also secrete a variety of inflammatory cytokines and chemokines. Therefore periodontal tissue aging might playa role in development and progress of periodontitis. In this study, we investigated the effect of in vitro periodontal ligament cellular aging on the inflammatory cytokines, chemokines, and matrix metalloprotease(MMP)-2 expression induced by lipopolysaccharide(LPS) treatment. Three different cell populations were used; passages 4-5, 14-15, and 24-25 (at passage 27, more than 90% cells were replicative senescent). LPS increased the expression of interleukin(IL)-1β, IL-6, and tumor necrosis factor-α, IL-8, RANTES, and MMP-2. However, the order of induction folds were passages 14-15 > 4-5 > 24-25. While the expression level of Toll-like receptor(TLR) 4 decreased according to the increase in passage number, the level of TLR2 was highest at passages 14-15 and then decreased at passages 24-25. While the spontaneous expression of IL-8 decreased according to the increase in passage number, that of RANTES and proMMP-2 increased according to the increase in passage number. These results suggest that the aging of periodontal ligament fibroblasts differentially affect the role as immunomodulatory cells in response to periodontopathic bacteria and therefore might be another risk factor of periodontitis progression.

골반저근은 골반기관을 지지하는 기능을 가지고 있으며 요자제를 유지하는 여성의 주요 하부조직이다. 골반저근의 약화는 복압성 요실금의 원인이 되는데, 이러한 골반저근의 기능 정도는 복압성 요실금의 병증정도를 평가하는 지표로 사용될 수 있다. 이에 본 연구에서는 골반저근의 수축 압력을 측정하여 복압성 요실금의 병적 진행정도를 정량적으로 진단할 수 있는 요실금 진단 알고리즘을 제안하였다. 이를 위하여 골반저근의 수축압력 정보를 측정할 수 있는 시스템을 제작하였으며, 측정된 데이터의 특징 분석을 위한 측정 프로토콜을 제안하였다. 복압성 요실금 환자로부터 획득한 데이터를 이용하여 5개의 진단 파라미터를 추출하였으며, 이를 이용한 진단 알고리즘을 구현하였다. 임상시험을 통하여 진단 알고리즘의 정확성을 평가한 결과 80%의 정확성을 보였으며, 20%의 위양성 진단 결과를 보였다. 반면에 위음성 진단 결과는 확인되지 않았다. 본 연구에서 제안한 요실금 진단 알고리즘은 복압성 요실금의 병적 진행 정도를 정량적으로 진단할 수 있으며, 요실금 진단 시스템 개발에 활용될 수 있을 것으로 판단된다.