New therapeutic measure are needed to improve the outcome for patients with oral squamous cell carcinoma(OSCC) because OSCC continues to portend a relatively unfavorable prognosis. Recently RNA interference(RNAi) has emerged as an effective method to target specific genes for silencing. Although overexpression of urokinase-type plasminogen activator receptor(uPAR) has been implicated in progression and metastasis of OSCC, the transfection effect of RNAi- uPAR on OSCC has been rarely reported. The purpose of this study were to examine the efficient and specific inhibition of uPAR mRNA and protein expression by siRNA targeting of uPAR through RT-PCR and immunoslot blotting, and to study cell proliferation activity, adhesion, invasion and migration in vitro compared to the controls. In MTT assay, siRNA-uPAR transfected cells showed about 70-80% cell proliferation compared to OSCC cell lines after 2 days. In adhesion assay, siRNA-uPAR transfected cells showed about 20-30% adhesion activity compared to OSCC cell lines, but similar features to those of BSA coated wells. In migration assay, siRNA-uPAR transfected cells showed about 60% migration activity compared to OSCC cell lines, but higher 3.5 folds to those of BSA coated wells. In invasion assay, siRNA-uPAR transfected cells showed about 55% invasive activity compared to parental cell lines. mRNA expression of siRNA-uPAR transfected cells showed about 10-15 % compared to parental cell lines by RT-PCR. Protein expression of siRNA-uPAR transfected cells showed about 25% compared to parental cell lines by ELISA assay. It suggested that RNAi-uPAR tranfection might be used as a potent and specific therapeutic tool for the treatment of oral squamous cell carcinoma, especially in inhibiting invasion and metastasis.

To examine the fluctuations of aerosol number concentration with different size in the boundary layer of marine area during summer season, aerosol particles were assayed in the Ieodo Ocean Research Station, which is located 419 km southwest of Marado, the southernmost island of Korea, from 24 June to 4 July, 2008. The Laser Particle Counter (LPC) was used to measure the size of aerosol particles and NCEP/NCAR reanalysis data and sounding data were used to analyze the synoptic condition. The distribution of aerosol number concentration had a large variation from bigger particles more than 3 μm in diameter to smaller particles more than 1 μm in diameter with wind direction during precipitation. The aerosol number concentration decreased with increasing temperature. An increase (decrease) of small size of aerosol (0.3∼0.5 μm in diameter) number concentration was induced by convergence (divergence) of the wind fields. The aerosol number concentration of bigger size more than 3 μm in diameter after precipitation was removed as much as 89∼94% compared with aerosol number concentration before precipitation. It is considered that the larger aerosol particles would be more efficient for scavenging at marine boundary layer. In addition, the aerosol number concentration with divergence and convergence could be related with the occurrence and mechanism of aerosol in marine boundary layer.

To understand the development mechanism of the aerosols in the surface boundary layer, the variation in the aerosol number concentration due to the divergence and convergence of the wind fields was investigated. The aerosol number concentration was measured in the size ranges of 0.3∼10.0 ㎛ using a laser particle counter(LPC) from 0000 LST on 03 Feb. to 0600 LST on 07 Feb. 2004 at Mokpo in Korea during snowfall. The Velocity Azimuth Display(VAD) technique was used to retrieve the radar wind fields such as the horizontal wind field, divergence, and deformations including the vertical air velocity from a single Doppler radar. As a result, the distribution of the aerosol number concentration is apparently different for particles larger than 1 ㎛ during snowfall, and it has a tendency to increase at the beginning of the snowfall. The increase and decrease in the aerosol concentration due to the convergence and divergence of the wind fields corresponded to the particles with diameters greater than 1 ㎛. It is found that the fluctuations in the aerosol number concentration are well correlated with the development and dissipation of snowfall radar echoes due to the convergence and divergence of horizontal wind fields near the surface boundary layer in the inland during the snowfall.

1998년 여름철, 기상레이더와 레이더 주위의 고밀도 우량계 관측자료를 이용하여 관계식을 산출하기 위하여 관악산 레이더 자료와 강우강도 자료의 확률밀도함수를 구해 확률이 같은 지점을 매치시키는 Window Probability Matching Method(WPMM)라는 통계적 방법을 사용하였다. 레이더 반사도의 확률 분포는 약 15dBZ에서 가장 많은 빈도 분포를 보였고 강우강도의 확률분포는 대부분의 영역에서 시간당 10mm 이하의 비가 내리는 것으로

To investigate the physio-chemical components and properties of aerosol particles in urban area sampling of aerosol particles was carried out in the campus of Hokkaido University, Sapporo, Japan, during snowfall. Aerosol particles were collected on millipore filter papers using a low volume air sampler. Their shapes, sizes and chemical components were analyzed by a SEM (Scanning Electron Microscope) and an EDX (Energy Dispersive X-ray). As a results, ice crystals of dendrite and column types were predominantly shown at mature and developing stage of snowfall intensity. The denerite and sector plate types of ice crystals were mainly originated from the sea but column types were come from soil. Scavenging effect by snowfall was greatly also shown at dendrite type ice crystals that embryo was fully developd. Al, Si elements were shown at high frequencies as compared with others. Na, Cl components were especially shown at high frequencies under the sea-breeze wind during snowfall. Anthropogenic aerosol particles had shown with irregular shapes and sizes, relatively. Mainly 3-7㎛ aerosol particles were abundant and coarse particles also could be seen during snowfall. Ca, Zn, Fe components mainly caused by spike tires from vehicles in winter season were dominant before snowfall, however the element S mainly caused by human activity was rich after snowfall. The pH values of snow in Sapporo city were higher than those at coastal area. The concentration of chemical components in aerosol particles was also affected by surface winds. Aerosol particles in urban area, Sapporo were mainly affected by human activities like vehicles and combustion with wind system. And their types were related with snowfall intensity.

The traffic accidents in large cities such as Pusan metropolitan city have been increased every year due to increasing of vehicles numbers as well as the gravitation of the population. In addition to the carelessness of drivers, many meteorological factors have a great influence on the traffic accidents. Especially, the number of traffic accidents is governed by precipitation, visibility, humidity, cloud amounts and temperature, etc. In this study, we have analyzed various data of meteorological factors from 1992 to 1997 and determined the standardized values for contributing to each traffic accident. Using the relationship between meteorological factors(visibility, precipitation, relative humidity and cloud amounts) and the total automobile mishaps, an experimental prediction formula for their traffic accident rates was seasonally obtained at Pusan city in 1997. Therefore, these prediction formulas at each meteorological factor may be used to predict the seasonal traffic accident numbers and contributed to estimate the variation of its value according to the weather condition in Pusan city.