• Nuclear Engineering and Technology
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• 제52권7호
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• pp.1471-1480
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• 2020

This research presents a case study on the remediation of a radioactive waste (uranium: U) utilizing a multi-objective fuzzy optimization in an electrocoagulation process for the iron-stainless steel and aluminum-stainless steel anode/cathode systems. The incorporation of the cumulative uncertainty of result, operational cost and energy consumption are essential key elements in determining the feasibility of the developed model equations in satisfying specific maximum contaminant level (MCL) required by stringent environmental regulations worldwide. Pareto-optimal solutions showed that the iron system (0 ㎍/L U: 492 USD/g-U) outperformed the aluminum system (96 ㎍/L U: 747 USD/g-U) in terms of the retained uranium concentration and energy consumption. Thus, the iron system was further carried out in a multi-objective analysis due to its feasibility in satisfying various uranium standard regulatory limits. Based on the 30 ㎍/L MCL, the decision-making process via fuzzy logic showed an overall satisfaction of 6.1% at a treatment time and current density of 101.6 min and 59.9 mA/㎠, respectively. The fuzzy optimal solution reveals the following: uranium concentration - 5 ㎍/L, cumulative uncertainty - 25 ㎍/L, energy consumption - 461.7 kWh/g-U and operational cost based on electricity cost in the United States - 60.0 USD/g-U, South Korea - 55.4 USD/g-U and Finland - 78.5 USD/g-U.

• Macromolecular Research
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• 제13권1호
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• pp.2-7
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• 2005

A series of ethylene polymerization catalysts based on tridentate bis-imine ligands coordinated to iron and cobalt was reported. The ligands were prepared through the condensation of sterically bulky anilines with allyloxy-and benzyloxy-substituted 2,6-acetylpyridines. The pre-catalyst complexes were penta-coordinate species of the general formula $\{[(ArN=C(Me))_2(4-RO-C_5H_3N)]MCl_2\}$ (Ar=ortho dialkyl-substituted aryl ring; R=allyl, benzyl; M=Fe, Co). In the presence of ethylene and methyl alumoxane cocatalysts, these complexes were active for the polymerization of ethylene, with activities lower than those of metal complexes of the general formula $\{[(2-ArN=C(Me)_2C_5H_3N]MCl_2\}$ (Ar=ortho dialkyl-substituted aryl ring; M=Co, Fe), containing no substituents in 2,6-acetylpyridine ring. The effects of the catalyst structure and temperature on the polymerization activity, thermal properties, and molecular weight were discussed.

• 지질공학
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• 제13권4호
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• pp.389-404
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• 2003

광주광역시의 하남산업단지 주변 및 도심지 광주천 일대의 37개 조사관정 중 21개 관정의 지하수에서 VOCs가 검출되었다. 염소계지방족 탄화수소는 37개 조사관정 중 18개 관정의 지하수에서 검출되었으며, 그 중 총트리할로메탄(TTHM)은 $0.1~36.2{\;}\mu\textrm{g}/L$의 분포를 보이고, CFC는 42.3~190{\;}\mu\textrm{g}/L$의 범위를 보이며, PCE, TCE 및 그 분해물들은 $0.1~124.2{\;}\mu\textrm{g}/L$의 농도를 보인다. 방향족탄화수소는 5개 관정의 지하수에서 10가지 성분이 검출되었으나, $0.2{\;}\mu\textrm{g}/L$ 미만의 낮은 농도로 나타났다. 하남산업단지 주변에서는 염소계지방족 탄화수소 성분이 광주천 인근 지하수 보다 검출빈도와 농도가 높게 나타나며, 지하수 시료중의 VOCs 성분은 TCE를 제외하고는 미국 음용수 기준치를 초과하지 않는다. TCE의 경우 하남산업단지에 소재하는 2개 지점의 지하수에서 먹는물 기준치($5{\;}\mu\textrm{g}/L$)를 각각 5배, 25배를 초과하는 것으로 나타났다 하남산업단지 지하수 시료중의 TCE 오염은 H8과 H10 관정에서, CFCs는 H8과 H11관정 부근의 지하수에서 검출되었다. 하남산업단지 주변 및 광주천 일대에서 검출된 TTHM은 상수도 및 하수도의 누출로부터 기원하는 것으로 판단된다. 연구 대상지역은 일부지역을 제외하고는 호기성지대로 구성되어 대부분의 방향족탄화수소는 분해가 잘되는 환경이나 염소계지방족 탄화수소는 대부분 생분해 반응이 서서히 일어나는 환경에 해당한다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권11호
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• pp.4475-4482
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• 2014

Background: Cisplatin, a DNA damaging agent, induces apoptosis through increasing DNA fragmentation. However, identification of intrinsic resistance molecules against Cisplatin is vital to estimate the success of therapy. Bag-1 (Bcl-2-associated anthanogene) is one anti-apoptotic protein involved in drug resistance impacting on therapeutic efficiency. Elevated levels of this protein are related with increase cell proliferation rates, motility and also cancer development. For this reason, we aimed to understand the role of Bag-1 expression in Cisplatin-induced apoptosis in HeLa cervix cancer cells. Cisplatin decreased cell viability in time- and dose-dependent manner in wt and Bag-1L+HeLa cells. Although, $10{\mu}M$ Cisplatin treatment induced cell death within 24h by activating caspases in wt cells, Bag-1L stable transfection protected cells against Cisplatin treatment. To assess the potential protective role of Bag-1, we first checked the expression profile of interacting anti-apoptotic partners of Bag-1. We found that forced Bag-1L expression prevented Cisplatin-induced apoptosis through acting on Mcl-1 expression, which was reduced after Cisplatin treatment in wt HeLa cells. This mechanism was also supported by the regulation of heat shock protein (Hsp) family members, Hsp90 and Hsp40, which were involved in the regulation Bag-1 interactome including several anti-apoptotic Bcl-2 family members and c-Raf.

• 한국식품위생안전성학회지
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• 제26권2호
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• pp.150-153
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• 2011

흰자작나무의 껍질에서 발견된 자연적으로 발생한 triterpene 인 betulinic acid (BA)가 다양한 종류의 암세포와 동물 모델에서 세포사멸을 유도하는 것으로 알려져 있다. 하지만 자궁경부암세포에서 BA의 화학적 암예방 효과는 연구되지 않은 상태이다. 따라서 이 연구에서는 사람 자궁경부암세포주인 KB세포를 이용하여, BA가 세포증식을 감소시키고 세포사멸을 유도하는 것을 확인하였다. KB 세포에서 BA에 의해 유도되는 세포증식의 억제는 specificity protein 1 (Sp1)과 Sp1의 표적단백질인 myeloid cell leukemia-1 (Mcl-1) 그리고 survivin의 감소 때문인 것으로 확인되었다. 따라서 BA는 자궁경부암에서 과다 발현되는 Sp1을 조절하는 새로운 화학적 암예방 물질로서 작용할 수 있을 것으로 생각된다.

• 한국식품위생안전성학회지
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• 제28권3호
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• pp.202-206
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• 2013

악성도가 높은 점액표피양 암종은 치료가 어렵고 5년 생존률이 매우 낮다. 따라서, 새로운 치료 물질과 분자표적을 찾는 것이 필요하다. Betulinic acid (BA)는 세계적으로 쉽게 얻을 수 있는 물질인 동시에 여러 종류의 종양에서 항암효과를 보인다. 또한 여러 정상 조직은 BA에 저항성을 보인다. 이 연구에서는 BA의 증식억제 효능과 MC-3 세포주에서의 분자 표적을 확인하고자 하였다. BA는 MC-3 세포주에서 세포 생존을 저해하였고 세포사멸을 유도하였다. BA는 Sp 1과 그의 하향 분자 표적인 survivin에 영향을 주었으나, 다른 하향 분자 표적인 Mcl-1에서는 유의한 변화를 일으키지 못하였다. 따라서, BA는 Sp1과 survivin을 조절하여 세포사멸을 일으키는 잠재적인 항암제 후보가 될 수 있을 것이라 사료된다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권3호
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• pp.82-92
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• 2013

This study has investigated naturally occurring radioactive materials (N.O.R.M; $^{238}U$, $^{222}Rn$) for 353 drinking groundwater wells in metamorphic rock areas in Korea. Uranium concentrations ranged from N.D (not detected) to 563.56 ${\mu}g/L$ (median value, 0.68 ${\mu}g/L$) and radon concentrations ranged from 108 to 11,612 pCi/L (median value, 1,400 pCi/L). Uranium and radon concentrations in the groundwater generally are similar to USA with similar geological setting. Uranium concentrations in 9 wells (2.6%) exceeded 30 ${\mu}g/L$, which is the maximum contaminant level (MCL) by the US environmental protection agency (EPA), radon concentrations in 46 wells (13%) exceeded 4,000 pCi/L, which is the Alternative MCL (AMCL) by the US.EPA. The log-log correlation coefficient between uranium and radon was 0.32. The correlation coefficient between uranium and pH was 0.12 and the correlation coefficient between radon and temperature was -0.01. The correlation coefficient between uranium and $HCO_3$ was 0.09 and the correlation coefficient between uranium and Ca was 0.11. The median value of uranium was high Chung-Buk (1.78 ${\mu}g/L$), Gyeong-Buk (1.37 ${\mu}g/L$), In-Cheon (1.06 ${\mu}g/L$) for each province. On the other hand, the median value of radon was high In-Cheon (2,962 pCi/L), Chung-Buk (2,339 pCi/L), Jeon-Buk (2,165 pCi/L) for each province. Jeon-Buk for log-log correlation coefficient is the highest (0.63) among provinces.

• 통합자연과학논문집
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• 제3권1호
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• pp.1-6
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• 2010

Bis(silyl)alkylbenzenes such as bis(1-sila-sec-butyl)benzene (1) and 2-phenyl-1,3-disilapropane (2) were synthesized in high yields by the reduction of the corresponding chlorosilanes with $LiAlH_4$ in diethyl ether. The dehydrocoupling of 1 and 2 was performed using group IV metallocene complexes generated in situ from $Cp_2MCl_2$/Red-Al and $Cp_2MCl_2$/n-BuLi (M = Ti, Hf), producing two phases of polymers. The TGA residue yields of the insoluble polymers were in the range of 64-74%. The molecular weights of the soluble polymers produced ranged from 700 to 5000 ($M_w$ vs polystyrene using GPC) and from 500 to 900 ($M_w$ vs polystyrene using GPC). The dehydropolymerization of 1 and 2 seemed to initially produce a low-molecular-weight polymer, which then underwent an extensive cross-linking reaction of backbone Si-H bonds, leading to an insoluble network polymer.

• 대한한의학회지
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• 제40권2호
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• pp.35-50
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• 2019

Objectives: Orostachys japonicas (O. japonicus) has been known for its anti-tumor effect. In the present study, it was investigated whether O. japonicus EtOH extracts could induce apoptosis and autophagy which are part of the main mechanism related to anti-tumor effect in THP-1 cells. Methods: Cells were treated with various concentrations of O. japonicus EtOH extracts ($0-300{\mu}g/ml$) for 24, 48, and 72h. Cell viability was evaluated by MTS/PMS assay and apoptosis rate was examined by flow cytometry and ELISA assay. The mRNA expression of apoptosis-related genes (Bcl-2, Mcl-1, Survivin, Bax) and autophagy-related gene (mTOR) was evaluated using real-time PCR. The protein expression of Caspase-3, Akt, LC3 II, Beclin-1, Atg5, $NF-{\kappa}B$, p38, ERK was evaluated using western blot analysis. Results: O. japonicus EtOH extracts inhibited cell proliferation and apoptosis rate was increased in both flow cytometry and ELISA assay. Bcl-2, Mcl-1, Survivin (anti-apoptosis factors) mRNA expressions were decreased and Bax (pro-apoptosis factor) mRNA level was increased. mTOR mRNA expressions was decreased and LC3 II protein expressions was increased. Activation of $NF-{\kappa}B$ was decreased and phosphorylation of p38 was increased. Conclusion: O. japonicus is regarded to inhibit cell proliferation, to induce apoptosis and to regulate autophagy-related genes in THP-1 cells via $NF-{\kappa}B$ and p38 MAPK signaling pathway. This suggests O. japonicus could be an effective herb in treating acute myeloid leukemia.

• Asian Pacific Journal of Cancer Prevention
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• 제15권16호
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• pp.6791-6798
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• 2014

Background: To investigate the effect of silibinin on proliferation and apoptosis in human gastric cancer cell line MGC803 and its possible mechanisms. Materials and Methods: Human gastric cancer cell line MGC803 cells were treated with various concentration of silibinin. Cellular viability was assessed by CCK-8 assay andapoptosis and cell cycle distribution by flow cytometry. Protein expression and mRNA of STAT3, and cell cycle and apoptosis regulated genes were detected by Western blotting and real-time polymerase chain reaction, respectively. Results: Silibinin inhibits growth of MGC803 cells in a dose- and time-dependent manner. Silibinin effectively induces apoptosis of MGC803 cells and arrests MGC803 cells in the G2/M phase of the cell cycle, while decreasing the protein expression of p-STAT3, and of STAT3 downstream target genes including Mcl-1, Bcl-xL, survivin at both protein and mRNA levels. In addition, silibinin caused an increase in caspase 3 and caspase 9 protein as well as mRNA levels. Silibinin caused G2/M phage arrest accompanied by a decrease in CDK1 and Cyclin B1 at protein and mRNA levels.. Conclusions: These results suggest that silibinin inhibits the proliferation of MGC803 cells, and it induces apoptosis and causes cell cycle arrest by down-regulating CDK1, cyclinB1, survivin, Bcl-xl, Mcl-1 and activating caspase 3 and caspase 9, potentially via the STAT3 pathway.