Caliber persistent artery (CPA) is a vascular anomaly presenting as a bluish and pulsatile artery in the subepithelial tissue. Although the incidence of CPA was debated, many CPAs occurred in the perioral and facial tissues at which the embryonal strapedial artery networks were distributed. The present study demonstrated a case of CPA occurred in the retromolar buccal mucosa in a 37 years old male. The lesion showed many pinkish granular spots, but was asymptomatic except biting irritation during mastication. It had slowly increased in size up to 20 × 25 mm for 3 years, and recently became hemorrhagic due to the biting injury between left upper and lower second molars. With the fear of oral cancer an incisional biopsy was performed, and followed by histological and immunohistochemical study. Histologically the lesion showed many tortuous artery localized at the submucosa area, and the arterial wall was thick and its lumen was narrowed and shrunken. In the immunochemistry α-SMA was positive for thick smooth muscle layer of artery and arterioles, TGase 2 was weakly positive for the luminal surface of arterial intima, and bFGF was consistently positive for the perivascular fibrous tissue. But PCNA, VEGF, CD31, CMG2, TGF-β1, HSP-70, and 14-3-3 were almost negative for the vascular tissue. Therefore, it was presumed that the lesion was not actively proliferative nor degenerative but still retained its cellular stability and slow growing potential. It was finally diagnosed as CPA differentially from arterio-venous malformation, hemangioma, lymphangioma, and squamous cell carcinoma. The retromolar buccal mucosa CPA is first reported in this study and may present usual clinical findings depending on its size and location. This asymptomatic lesion could be severely hemorrhagic by minor biting injury, therefore, precise differential diagnosis should be made through biopsy, and careful therapy be followed.

본 연구에서는 pH 변화에 따른 카올리나이트-휴믹산, 카올리나이트-아메리슘 및 휴믹산-아메리슘 등의 이성분계 흡착반응을 조사하였다. 카올리나이트의 물리화학적 특성을 조사한 후, 휴믹산농도, 이온강도 및 pH 변화에 따른 카올리나이트에 휴믹산의 흡착실험을 하였다. pH 및 HA 농도가 증가함에 따라 KA에 대한 HA의 흡착율이 감소하였으나, 이온강도가 증가함에 따라 HA의 흡착율이 증가하였다. 또한 pH 변화에 따른 카올리나이트와 아메리슘과 흡착반응 및 아메리슘과 휴믹산과의 흡착반응도 연구하였다. 산성 및 중성영역에서는 Am이 HA에 쉽게 흡착되었으나, 염기성 영역에서는 정전기적 반발력으로 HA에 대한 Am 흡착이 감소되었다. 본 연구 결과는 수환경에서 휴믹산에 의한 아메리슘 흡착거동 특성을 이해하는데 활용이 가능하다

산지하천 만곡부의 홍수피해를 줄이고자 사다리꼴 단면의 돌출줄눈을 하천옹벽에 설치하였다. 본 연구에서는 사다리꼴 형상에 의한 흐름저항 효과를 파악하고자 개수로 측벽에 사다리꼴 돌출줄눈을 설치하여 수리실험을 수행하였다. 벽면조도가 κ형에 해당하는 λnυ가 6, 9, 12인 경우에 대해 유량에 따른 흐름특성을 파악하였다. 흐름저항은 돌줄줄눈의 설치간격이 멀어짐에 따라 전반적으로 증가하였다. 고유량 조건에서 최대마찰계수는 λnυ가 9일 때 발생하였다. 사다리꼴 돌출줄눈은 정사각형 돌출줄눈과 비교해 흐름저항은 상대적으로 작았지만, 사다리꼴의 형상저항은 전체흐름저항의 평균 62%를 차지했다. 벽면조도 증가에 따른 흐름저항 효과를 극대화하기 위한 사다리꼴 돌출줄눈의 최적 설치간격은 돌출줄눈 높이의 9∼12배 범위임을 확인하였다.

Influences of different seeding dates on growth, seed yield, fatty acid composition and oil content were investigated in flax plants for two years. The results indicated that plant height in early seeding date was higher than that of delayed seeding dates during first season. Furthermore, seeding date also significantly affected the ripened seed rate and the rate increased with the delay in seeding date in first season. Seed yield in the first crop season was significantly higher than the second crop season. Palmitic acid showed variation in different seeding dates. Contrarily, stearic acid was stable and did not changed by different seeding dates. Linolenic acid was found in highest amount in all seeding dates consecutively in two cropping years. Highest oil content was recovered from the seeds of flax sown at 29 Apr. and May 9 in first and second cropping year respectively.