http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
허영철,조재환,한동균 대한의학회 2017 Journal of Korean medical science Vol.32 No.7
This is a study on the dose-decreasing effect of the first reversed laser beam collimator (RLBC) for C-arm type angiographic equipment. A laser beam was located at the center of each plane at an oblique angle to the angiographic equipment detector. A field of view, which could be seen with the naked eye, was made by focusing the laser beam in the direction of the X-ray source. The height of the table was fixed at 75 cm and the iron balls were located within 2 mm of the top, bottom, left, and right edges of the output image. The time needed for location fixing, fluoroscopy, and measurement of dose area product (DAP) were compared by having 30 radiologists perform location fixing by looking at the fluoroscopic image while performing location fixing (no radiation) and while the RLBC was turned on. In the next test, the time needed for location fixing, fluoroscopy, and DAP were compared when varying the location of the iron balls from 2 to 10 mm from the edges of the output image. The results showed that the time needed for location fixing, the time needed for fluoroscopy, and DAP decreased, both in the first test and the second test. This study confirmed that the use of a RLBC for C-arm type angiographic equipment decreases both the time needed to perform the procedure and the radiation dose received. It is expected that continuous advancement of RLBC technology will contribute greatly to decreasing the dose of radiation needed and improving convenience during angiography.
허영철,방홍순,김옥규 대한건축학회지회연합회 2021 대한건축학회연합논문집 Vol.23 No.5
In this study, the cause of secondary defects is analyzed to improve the construction process and resolve conflicts between construction companies and residents. This study is based on data collected from January 2017 to December 2019 prior to the revision of the current Enforcement Decree of the Apartment Management Act. After analyzing the secondary defect data, we obtain results that certain processes are more affected by primary defects than others. Wood flooring accounts for the largest portion with 13.77% of the total number of defect reports, but stone works account for the largest portion with 18.04% of the total defect repair costs. Depending on what criteria it is analyzed, the ranking of construction works that are greatly affected by primary defects varies.
허영철,김명수,여환호 朝鮮大學校 口腔生物學硏究所 1997 Oral Biology Research (Oral Biol Res) Vol.21 No.1
To study the effect of 3'.5'-cyclic adenosine monophosphate (cAMP) analogs on the growth of cancer cells. 6 cAMP analogs were applied to 3 cancer cell lines (KB, HeLa, CaSki) for 72 hours. Cells were labelled with ^3[H]-thymidine to measure the DNA synthesis which reflects cell growth rate. The growth of cancer cell lines were suppressed by cyclic AMP analogs and the magnitude of the inhibitory effect was different among cancer cell lines. N^6-benzoyl cAMP, 8-bromo cAMP and 8-methylamino cAMP suppressed the growth of KB at the highest concentration used. N^6-benzoyl cAMP, 8-bromo cAMP, 8-methylamino cAMP and 8-(aminohexyl)amino cAMP suppressed the growth of HeLa cell line. 8-bromo cAMP and 8-(aminohexyl)amino cAMP were more effective than other agents. N^6-benzoyl cAMP and 8-bromo cAMP suppressed the growth of CaSki cell line very effectively at concentrations which have very limited suppressive effect on KB and HeLa cell lines. 8-methylamino cAMP and 8-(aminohexyl)amino cAMP also effectively suppressed the growth of CaSki cells. However, 8-chlorophenylthio cAMP suppressed the growth of cancer cell lines at relatively high concentrations. And N^6, O^2-dibutyryl cAMP exerted only limited suppressive effect on the growth of cancer cell lines. In summary, the growth of cancer cells can be suppressed by cAMP analogs and some cAMP analogs can selectively inhibit certain types of cancer cells. The susceptibility of cancer cells to cAMP analogs could be dependent on the activity of intracellular cAMP-dependent protein kinase. Our results prompt the necessity for the development of cAMP analogs which have selective growth inhibitor effect on specific cancer cells for the effective treatment of cancers with minimal toxic effect on normal cells.
Comparison of Subtracted Venography and Phase Contrast in Cerebral Regions by Utilizing 3DT1TFE
허영철,조재환,장현철,이창희,김정수,이해각 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.11
In this study, we evaluated the 3D venography images and the phase contrast images that were subtracted by using the images that had been obtained before and after utilizing the contrast medium with a 3D, segmented, T1-weighted gradient echo sequence (3DT1TFE) when performing a cerebral magnetic resonance imaging (MRI) examination with contrast medium. The study was carried out in 10 patients who under went a brain examination with a contrast medium by using the 3.0T MR System and 8-channel sensitivity encoding (SENSE) head coil. The 3DT1TFE images after the contrast medium had been used was subtracted from the 3DT1TFE images before the utilization. The subtracted images were re-formed to venography images by using maximum intensity projection (MIP) techniques; then, the re-formed images and 3D phase contrast (PC)venography were evaluated qualitative analysis. The qualitative analysis was done to confirm the reliability of the ratings of the observers via the ICC (intraclass correlation coefficient) and then to evaluate of the statistical significance via an independent T-test. The ICC test showed that 3D PC venography images and subtracted venography images had reliabilities of 0.677 and 0.734on average, respectively, indicating good reliability of the ratings by the observers. Because the proximal superior sagittal sinus (SSS), the middle SSS, the confluence SSS, the vein of labbe, the internal cerebral vein, and the Vein of Galen represented p > 0.05 a the independent T-test, no statistically significant difference was observed between the two images. However, a significant difference was observed between the images regarding the straight sinus (p < 0.05). As such, the venography images subtracted from the straight sinus would be better, because the average of the straight sinus was higher in subtracted venography.