• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.209-209
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• 1994

천연자원으로부터 얻어진 항암 또는 세포독성물질로는 주로 alkaloid, lignan, terpenoid, macrolide 등에 속하는 물질들이고 그 중 sesquiterpene lactone계열 화합물에서 세포독성 및 항종양 활성이 있는 물질이 다수 얻어졌으며 그 대부분은 국화과의 식물에서 분리 보고되고 있다. Achillea 속 식물은 국화과에 속하는 다년생초본으로 남한에는 톱풀과 산톱풀 2종만이 자생한다. screening 결과 이 두 식물에는 segquiterpene lactone 화합물과 Peroxide등 다수의 활성성분이 함유되어 있을 것으로 기대되어 본 연구에 착수하였다. 두 식물의 각 분획에 대하여 SNU-1(위암세포주)과 SNU-354(간암세포주)를 이용해 검색한 결과 두 식물 모두 MC ext.와 MeOH ext.에서 현저한 세포독성을 보였으며 현재 MC ext. 로부터 세포독성물질의 분리를 수행하고 있다. EtOAc ext.는 세포독성은 거의 나타내지 않았으나 flavonoid 성분이 다수 존재함을 확인하였으며 면역활성 및 enzyme inhibition등의 활성을 검토하고자 화합물을 분리하였다. 그 결과 톱풀로 부터는 luteolin-7-0-glucoside와 apigenin-7-0-glucoside를 그리고 산톱풀로부터는 luteolin-7-0-glucoside, apigenin-7-0-glucoside, luteolin, apigenin을 분리 확인 동정하였다.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
• /
• pp.210-210
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• 1994

천연자원으로부터 얻어진 항암 또는 세포독성물질로는 주로 alkaloid, lignan, terpenoid, macrolide 등에 속하는 물질들이고 그 중 sesquiterpene lactone계열 화합물에서 세포독성 및 항종양 활성이 있는 물질이 다수 얻어졌으며 그 대부분은 국화과의 식물에서 분리 보고되고 있다. Achillea 속 식물은 국화과에 속하는 다년생초본으로 남한에는 톱풀과 산톱풀 2종만이 자생한다. screening 결과 이 두 식물에는 segquiterpene lactone 화합물과 Peroxide등 다수의 활성성분이 함유되어 있을 것으로 기대되어 본 연구에 착수하였다. 두 식물의 각 분획에 대하여 SNU-1(위암세포주)과 SNU-354(간암세포주)를 이용해 검색한 결과 두 식물 모두 MC ext.와 MeOH ext.에서 현저한 세포독성을 보였으며 현재 MC ext. 로부터 세포독성물질의 분리를 수행하고 있다. EtOAc ext.는 세포독성은 거의 나타내지 않았으나 flavonoid 성분이 다수 존재함을 확인하였으며 면역활성 및 enzyme inhibition등의 활성을 검토하고자 화합물을 분리하였다. 그 결과 톱풀로 부터는 luteolin-7-0-glucoside와 apigenin-7-0-glucoside를 그리고 산톱풀로부터는 luteolin-7-0-glucoside, apigenin-7-0-glucoside, luteolin, apigenin을 분리 확인 동정하였다.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.5
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• pp.18-26
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• 1993

This paper presents the design method for two-dimensional FIR digital filter using optimization scheme. The proposed design method is to extend the optimal one-dimensional filter design algorithm proposed by Parks and McClellan to two-dimensional case. When extending one-dimensional design scheme to two-dimensional one, some problems occur. In this paper we solved the problems by using the least square error model, the two-dimensional Lagrange interpolation, and the modified alternation theory. As a result, the equi-ripple FIR filter is obtained that is more optimal and more specific than the conventional methods.

• Bulletin of the Korean Chemical Society
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• v.23 no.6
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• pp.851-856
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• 2002

The Reaction of S-methyl-S-cysteine(L-Smc) with racemic $s-cis-[Co(demba)Cl_2]-1$ (Hydmedba = $NN'-dimethylethylenediamine-NN'-di-\alpha-butyric$, acid) yields ${\Delta}$-s-cis-[Co(dmedba)(L-Smc)] 2 with N, O-chelation. Oxidation of sulfur of 2 with $H_2O_2$ in a 1 : 1 mole ratio gives ${\Delta}$-s-cis[Co(dmedba)(L-S(O)mc)] 3 having an uncoordinated sulfenate group. Oxidation of sulfur of L-Sm with $H_2O_2in$ a 1: 1 mole ratio produces S-methyl-L-cysteinesulfenate (L-S(O)me) 5. Direct reaction of 1 with 5 in basic medium gives an N.O-chelated ${\Delta}$s-cis[Co(dmedba)(L-S(O)mc)-N.O], which turmed out be same as obtained by oxidation of 2, while an N, S-chelated ${\Delta}$-s-cis-[Co(dmedba)(S-S(O)mc)-N,O] complex 4 is obtained in acidic medium from the reaction of 1 with 5. This is one of the rare $[$Co^{III}$(N_2O_2-type$ ligand)(amino acid)] type complex preparations, where the reaction conditions determine which mode of N, O and N, S caelation modes is favored.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.3
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• pp.629-632
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• 2003

Scutellaria barbata has been used as a traditional Chinese Herb for treating liver, lung and rectal tumors. In the present study, cytotoxic effect of Scutellaria barbata MC fradtion was investigated and it was found to inhibit proliferation of human leukemic U937 cells with an IC50 of approximately 10 μg/ml in a dose-dependent manner. We also demonstrated that Scutellaria barbata MC fraction caused apoptosis in U937 cells. In the flow cytometric assay, the MC fraction-treated U937 cells showed an increase in hypo-diplold Sub G1 DNA contents. DNA fragmentation was observed by TUNEL assay. An increase of Bax:Bcl-2 ratio, activation of caspase-9, caspase-3, and cleavage of poly (ADP-ribose) polymerase (PARP) were demonstrated by western blot analysis. Taken together, these results exerted that the MC fraction suppressed human leukemic U937 cell proliferation by inducing apoptosis via the mitochondrial pathway.

• New Physics: Sae Mulli
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• v.68 no.12
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• pp.1331-1337
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• 2018

We present a three-parameter phase shift model whose form is the same as that of Coulombmodified Glauber model obtained from Gaussian nuclear densities. This model is applied to the $^6Li+^{12}C$ and the $^6Li+^{28}Si$ elastic scatterings at $E_{lab}=318MeV$. The calculated differential cross sections provide quite a satisfactory account of the experimental data. The diffractive oscillatory structures observed at forward angles can be explained as being due to the strong interference between the near-side and the far-side scattering amplitudes. The optical potentials for two systems are predicted by using the method of inversion. The calculated inversion potentials are found to be in fairly good agreements with the results determined from the optical model analysis in the surface regions around the strong absorption radius. We also investigate the effects of parameters in the three-parameter phase shift model on the elastic scattering cross sections.

• Broadcasting and Media Magazine
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• v.15 no.4
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• pp.123-134
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• 2010

차세대 비디오 코덱인 HEVC (High Efficiency Video Coding)는 높은 코딩 성능과 상대적으로 낮은 처리 복잡도를 제공하기 위해 표준화 과정을 통해 여러 가지 코딩 툴들을 검증하고 있다. 이 중 메모리압축기술은IBDI 적용에 따른 참조 메모리 크기 및 메모리 대역폭 증가를 줄이거나 또는 8 비트 연산일지라도 초고해상도를 다루는 HEVC 특성상 ME, MC 과정에서 발생하는 메모리 대역폭을 줄이기 위해 고안된 기술이다. 본 기고는 다양한 메모리 압축 기술들을 소개하고 코딩 성능 측면, 계산 복잡도 측면, 그리고 메모리 대역폭 감소 측면에서 각 기술들을 비교하고 향후 메모리 압축 기술의 전개방향에 대해 설명하고자 한다.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.5
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• pp.25-32
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• 1998

In this paper, SA (shape adaptive)-DCT is implemented using a datapath with 4 MACs (multiplication & accumulator). DCT is a well-known bottleneck of real-time video compression using MPEG-like schemes. High-speed pipelined MACs presented here implement real-time DCT. A datapath in this paper executes DCT/IDCT algorithms for QCIF 15fps(frame per second), maximum rate of VLBV(very low bitrte video) in MPEG-4. A 32bit accumulator in a MAC prevents distortion caused by fixed-point process. It can be applied to various operations such as ME (motion estimation) and MC(motion compensation) with a absolutor and a halfer.

• Journal of Astronomy and Space Sciences
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• v.22 no.4
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• pp.441-450
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• 2005

The organic material is one of the most popular material for the satellites and the spacecrafts in order to perform the thermal management, and to protect direct exposure from the space environment. The present paper observes material property changes of organic material under the space environment by using ground facilities. One of the representative organic thermal management material of satellites, 2 mil ITO(Indium Tin Oxide) coated aluminized KAPTON was selected for experiments. In order to investigate the single parametric effect of protons in space environment, MC-50 cyclotron system in KIRAMS(Korea Institute of Radiological and Medical Science) was utilized for the ion beam irradiation of protons and ion beam dose was set to the Very Large August 1972 EVENT model, the highest protons occurrence near the earth orbit in history. The energy of ion beam is fixed to 30MeV(mesa electron volt), observed average energy, and the equivalent irradiance time conditions were set to 1-year, 3-year, 5-year and 10-year exposure in space. The procedure of analyses includes the measurement of the ultimate tensile strength for the assessment of quantitative degradation in material properties, and the imaging analyses of crystalline transformation and damages on the exposed surface by FE-SEM(Field Emission Scanning Electron Spectroscopy) etc.

• Radiation Oncology Journal
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• v.24 no.4
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• pp.280-284
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• 2006

$\underline{Purpose}$: To evaluate biological characteristics of neutron beam generated by MC50 cyclotron located in the Korea Institute of Radiological and Medical Sciences (KIRAMS). $\underline{Materials\;and\;Methods}$: The neutron beams generated with 15 mm Beryllium target hit by 35 MeV proton beam was used and dosimetry data was measured before in-vitro study. We irradiated 0, 1, 2, 3, 4 and 5 Gy of neutron beam to EMT-6 cell line and surviving fraction (SF) was measured. The SF curve was also examined at the same dose when applying lead shielding to avoid gamma ray component. In the X-ray experiment, SF curve was obtained after irradiation of 0, 2, 5, 10, and 15 Gy. $\underline{Results}$: The neutron beams have 84% of neutron and 16% of gamma component at the depth of 2 cm with the field size of $26{\times}26\;cm^2$, beam current $20\;{\mu}A$, and dose rate of 9.25 cGy/min. The SF curve from X-ray, when fitted to linear-quadratic (LQ) model, had 0.611 as ${\alpha}/{\beta}$ ratio (${\alpha}=0.0204,\;{\beta}=0.0334,\;R^2=0.999$, respectively). The SF curve from neutron beam had shoulders at low dose area and fitted well to LQ model with the value of $R^2$ exceeding 0.99 in all experiments. The mean value of alpha and beta were -0.315 (range, $-0.254{\sim}-0.360$) and 0.247 ($0.220{\sim}0.262$), respectively. The addition of lead shielding resulted in no straightening of SF curve and shoulders in low dose area still existed. The RBE of neutron beam was in range of $2.07{\sim}2.19$ with SF=0.1 and $2.21{\sim}2.35$ with SF=0.01, respectively. $\underline{Conclusion}$: The neutron beam from MC50 cyclotron has significant amount of gamma component and this may have contributed to form the shoulder of survival curve. The RBE of neutron beam generated by MC50 was about 2.2.