• 한국안광학회지
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• 제7권2호
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• pp.189-195
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• 2002

점안액 보존제 성분으로 이용되는 Benzalkonium Chloride(BAC)가 배양 각막 상피세포에 미치는 영향을 조사하기 위해 본 연구를 시행하였다. BAC를 세포에 0.0001%~0.01%로 15분 동안 처리하여 24시간 후 회복 효과를 조사하였다. MTT assay를 이용하여 세포 생존율을 산정하고 Hoechst 33342로 염색질 응축을 조사하였다. Fas 발현 여부를 조사하기 위해 western blot과 immunocytochemistry를 이용하였으며 DNA fragmentation은 agarose gel을 이용한 전기영동을 시행하였다. BAC를 0.005% 이상 처리하면 세포괴사가 일어나는 반면에 저농도의 BAC는 세포고사를 유도하는 것으로 나타났으며 BAC로 Fas 발현이 유도될 수 있다는 것을 보여주고 있다. 본 연구를 통해 점안액의 대표적인 보존제인 BAC의 부작용에 대한 각막세포 차원의 연구가 필요하며 세포독성이 없는 새로운 보존제의 개발이 필요한 것으로 나타났다.

• 한국어류학회지
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• 제12권2호
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• pp.111-117
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• 2000

양어장에서 염분농도가 각각 $5^{\circ}/_{\circ\circ}$, $10^{\circ}/_{\circ\circ}$, $15^{\circ}/_{\circ\circ}$의 $1.5m^3$인 사육조에서 순치 적응된 평균 체중이 130g인 smolt 단계의 치어와 870g인 성어의 무지개송어 (Oncorhynchus mykiss) 총 150마리를 공시어로 이용하여 아가미 및 신장의 미세구조의 변화를 알기 위해서 광학 및 전자현미경으로 관찰하여 얻어진 결과는 다음과 같다. 해수에 순치 적응된 무지개송어에서 아가미엽의 비대와 아가미엽 상피세포의 분리 그리고 신사구체의 수축, 신장의 응혈 등의 조직학적 변화가 나타났다. 해수에 순치 적응된 개체의 삼투압은 당수에 서식하는 개체의 삼투압보다 높게 나타나서 평균 300 m Osmol 이상으로 나타났다. 삼투압의 증가는 염분과 무기질의 배출효율을 높이기 위해서 혹은 체내의 삼투압의 균형을 맞추기 위해서 삼투압이 증가하는 것으로 사료된다. 아가미엽의 염세포가 증가하는 발생정도는 염분농도의 증가와 더불어 높게 나타났고, 아가미엽 표면은 염분농도가 높아질수록 요철상태가 심한 구조로 나타났으며, 길게 변형된 미토콘드리아가 관찰되었다. 무지개송어는 조직병리학적 변화에도 불구하고 해수에 순치 적응하는 것으로 나타났다.

• BMB Reports
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• 제36권5호
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• pp.468-474
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• 2003

The molecular mechanism of hypoxia-induced apoptosis has not been clearly elucidated. In this study, we investigated the involvement of extracellular signal-regulated protein kinase (ERK 1/2) in hypoxia-induced apoptosis using cobalt chloride in HeLa human cervical cancer cells. The cobalt chloride was used for the induction of hypoxia, and its $IC_{50}$ was $471.4\;{\mu}M$. We demonstrated the DNA fragmentation after incubation with concentrations more than $50\;{\mu}M$ cobalt chloride for 24 h, and also evidenced the morphological changes of the cells undergoing apoptosis with electron microscopy. Next, we examined the signaling pathway of cobalt chloride-induced apoptosis in HeLa cells. ERK1/2 activation occurred 6 and 9 h after treatment with $600\;{\mu}M$ cobalt chloride. Meanwhile, the pretreatment of the MEK 1 inhibitor (PD98059) completely blocked the cobalt chloride-induced ERK 1/2 activation. At the same time, the activated ERK 1/2 translocated into the nucleus and phosphorylated its transcriptional factor, c-Jun. In addition, the pretreatment of PD98059 inhibited the cobalt chloride-induced DNA fragmentation and apoptotic cell death. These results suggest that cobalt chloride is able to induce apoptotic activity in HeLa cells, and its apoptotic mechanism may be associated with signal transduction via ERK 1/2.

• 한국식품과학회지
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• 제28권4호
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• pp.707-713
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• 1996

김치제조의 산업화로 현장에서 도움이 될 수 있는 배추의 절임조건의 영향을 보고자 절임수의 온도 및 절임 시간, 절임시 적재높이, 세척조건, 탈수조건 등을 달리하여 실험하였다. 절임시간이 길수록 그리고 절임수의 온도가 높을수록 절인 배추의 소금농도가 높아짐을 관찰할 수 있었다. 적재 높이를 고려한 배추의 염도 측정에서는 하단의 염도가 상단보다 더 높게 나타났다. 세척과 탈수를 할수록 염도가 떨어지는 경향을 나타냈다. 높이에 따른 배추의 미세구조 변화에서 절인 배추의 세포조직은 높이에 따라 서로 차이를 나타냈다. 염절임을 한 배추는 세척을 할수록 원래의 상태로 회복되는 경향을 나타내었다.

• KSBB Journal
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• 제23권5호
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• pp.381-386
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• 2008

본 연구에서는 암모니아에 의해 손상된 사람의 간세포주 Hep G2 cell과 rat의 hepatocyte에 대하여 metronidazole이 간 세포 손상을 억제하는 효과가 있음을 밝혔다. Metronidazole은 암모니아에 의한 세포 생존율 감소, 배지내의 암모니아 수준 및 지질과산화 증가 및 항산화 효소 발현 감소 그리고 세포 내 DNA 손상과 세포사멸을 억제하였다. 따라서 metronidazole은 암모니아로부터 기인하는 세포손상을 감소시켜 간세포 기능을 보호함으로써 간 기능의 저하로 발생한 과암모니아혈증에 효과적인 치료제로서의 가능성을 시사한다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.801-804
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• 2004

It should be noted that the critical chloride threshold level is not considered to be a unique value for all conditions. This value is dependent on concrete mixture proportions, cement type and constituents, presence of admixtures, environmental factors, steel reinforcement surface conditions, and other factors. In this study, the accelerated corrosion test for reinforcing steel was conducted by electrochemical and sea water-circulated method, respectively and during the test, corrosion monitoring by half cell potential method was carried out to estimate the critical chloride threshold value when corrosion for reinforcing steel in concrete was perceived. For this purpose, lollypop and beam test specimens were made for $31.4\%,\;41.5\%\;and\;49.7\%$ of w/c. respectively and then the accelerated corrosion test for reinforcing steel was executed. It was observed from the test that the time to initiation of corrosion was found to be different with water-cement ratio and the critical chloride threshold value was found to range from 0.91 to $1.27kg/m^3$.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 추계 학술논문 발표대회
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• pp.61-62
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• 2017

In this study, the initiation of steel corrosion was monitored due to chloride attack using embedded sensor. In general, Steel bars embedded in concrete are protected from corrosion by being forming a passive film on the surface. However, the passive film is destroyed by chemical erosion such as concrete carbonation and chloride penetration, and the rebar is exposed to the deteriorating factor and corrosion proceeds. In order to realize the initiation of steel corrosion, OCP and change of Impedance parameter were observed by using Half-cell and EIS method depending on cover depth. As result, 10mm cover showed the impedence increased in 6weeks.

• Mycobiology
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• 제35권3호
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• pp.124-128
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• 2007

Ganoderma resinaceum tolerated sodium chloride salt stress within a range of 0 mM till 300 mM. It responded to salt stress with fluctuation in proline formation at different NaCl concentrations. However, the mycelial dry weight, total protein contents and exopolysaccharides did not changed considerably. Increasing sodium chloride concentration led to morphological alteration in fungal mycelia with disappearance of fungal cell wall, plasmolysis, and vacuolation as indicated with electron microscopic examination of the fungal growth.

• Bulletin of the Korean Chemical Society
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• 제16권3호
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• pp.205-210
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• 1995

Catalytic effects of various Schiff base metal(II) complexes on the reduction of thionyl chloride at glassy carbon electrode are evaluated by determining the kinetic parameters from cyclic voltammetry technique. The charge transfer process is affected strongly by the concentration of catalysts during the reduction of thionyl chloride. The catalytic effects are shown by both a shift of the reduction potential for thionyl chloride toward more positive direction and an increase in peak current. The diffusion coefficient value, Do, of the 8.17 ${\times}$ 10-9 $cm^2/s$ was observed at the bare glassy carbon electrode, whereas larger values (0.9-1.09 ${\times}$ 10-8 $cm^2/s$) were observed at the catalyst supported glassy carbon electrode. Significant improvements in the cell performance have been noted in terms of both exchange rate constants and current densities at glassy carbon electrode.

• Journal of Preventive Medicine and Public Health
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• 제39권3호
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• pp.199-204
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• 2006

Objectives: Mercury is a hazardous organ-specific environmental contaminant. It exists in a wide variety of physical and chemical states, each of which has unique characteristics for the target organ specificity. Exposure to mercury vapor and to organic mercury compounds specifically affects the CNS, while the kidney is the target organ for inorganic Hg compounds. Methods: In this study, mercury chloride $(HgCl_2)$ was studied in a renal derived cell system, i.e., the tubular epithelial Madin-Darby canine kidney (MDCK) cell line, which has specific sensitivity to the toxic effect of mercury. MDCK cells were cultured for 6-24 hr in vitro in various concentrations (0.1-100 M) of $HgCl_2$, and the markers of apoptosis or cell death were assayed, including DNA fragmentation, caspase-3 activity andwestern blotting of cytochrome c. The influence of the metal on cell proliferation and viability were evaluated by the conventional MTT test. Results: The cell viability was decreased in a time and concentration dependent fashion: decreases were noted at 6, 12 and 24 hr after $HgCl_2$, exposure. The increases of DNA fragmentation were also observed in the concentrations from 0.1 to 10 M of $HgCl_2$ at 6 hr after exposure. However, we could not observe DNA fragmentation in the concentrations more than 25 M because the cells rapidly proceeded to necrotic cell death. The activation of caspase-3 was also observed at 6 hr exposure in the $HgCl_2$ concentrations from 0.1 to 10 M. The release of cytochrome c from the mitochondria into the cytosol, which is an initiator of the activation of the caspase cascade, was also observed in the $HgCl_2-treated$ MDCK cells. Conclusions: These results suggest that the activation of caspase-3 was involved in $HgCl_2-induced$ apoptosis. The release of cytochrome c from the mitochondria into the cytosol was also observed in the $HgCl_2-treated$ MDCK cells. These findings indicate that in MDCK cells, $HgCl_2$ is a potent inducer of apoptosis via cytochrome c release from the mitochondria.