• Corrosion Science and Technology
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• 제9권6호
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• pp.247-253
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• 2010

The characteristics of selective oxidation prior to hot-dip galvanizing with the annealing atmosphere dew point and chemical composition in dual-phase steels and their effect on the inhibition layer formation relevant to coating adhesion have been studied using a combination of electron microscopic and surface analytical techniques. The annealed and also galvanized samples of 3 kinds of Si/Mn ratios with varied amounts of Si addition were prepared by galvanizing simulator. The dew point was controlled at soaking temperature $800^{\circ}C$ in 15%$H_2$ -85%$N_2$ atmosphere. It was shown that good adhesion factors were mainly uniformity of oxide particle distribution of low number density and low Si/Mn ratio prior to hot-dip galvanizing. Their effect was the greatly reduced coating bare spots and the formation of uniform inhibition layer leading to good adhesion of Zn overlay. The mechanism of good adhesion is suggested by two processes: the formation of inhibition layer on the oxide free surface uncovered with no $SiO_2$-containing particles in particular, and the inhibition layer bridging of oxide particles. The growth of inhibition layer was enhanced markedly by the delayed reaction of Fe and Al with the increase of Si/Mn ratio.

• 환경생물
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• 제39권4호
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• pp.479-485
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• 2021

고추에서 Colletotrichum scovillei를 검출하고 계수하기 위한 반선택배지가 개발되었다. 기본배지로서 Potato-dextrose-agar (PDA)가 사용되었다. 반선택배지의 최종 조성은 부생성곰팡이와 세균을 저해하고, C. scovillei의 생장에 양호할 수 있도록 확립되었다. 반선택배지는 pyribencarb와 pydiflumetofen 각각 40 ㎍ mL^-1와 세균을 방지하기 위한 streptomycin 100 ㎍ mL^-1를 포함한다. 배지의 pH는 85% lactic acid로 4.8로 조절했다. 반선택배지에 배양할 때 C. scovillei의 균사생육 저해율은 Fusarium속과 다른 부생균보다 뚜렷이 낮았다. 반선택배지에 과실과 줄기조직 현탁액을 평판배양하여 탄저병균이 자연 감염된 식물체로부터 C. scovillei가 검출되었고, 신뢰할 수 있고 정량할 수 있었다. 이것은 자연 감염된 고추조직에서 C. scovillei의 존재를 검출하기 위한 반선택성배지에 대한 처음 보고이다.

• 혜화의학회지
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• 제3권2호
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• pp.315-321
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• 1995

An extensive anticancer drug screening from natural resources has been carried out primarily using murine tumor model for past fourty years. Recently a new screening program from NCI, so called disease-oriented screening system. has been estabished to detect anticancer drugs that show selective growth inhibition toward variety of tissue specific human solid tumors originated from leukemia, lung, colon, CNS, melanoma, ovarian, renal, prostate amd breast. To develope the anticancer drugs from oriental medicinal herbs, we investigated the cytotoxic effects against human tumor cell panels with 23 kinds of MeOH extract of medicinal herbs. Evodiae Fructus, Meliae Toosendan Fructus, Saussureae Radix and Pharbitidis Semen showed strong activities against several tumor cell lines.

• Radiation Oncology Journal
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• 제23권1호
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• pp.51-60
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• 2005

목적 : 분자 표적의 선택적 억제가 방사선 세포 살상 효과를 증진시키는 것으로 알려져 있으므로 선택적 COX-2 억제제와 EGF 수용체 차단제를 HeLa 세포주에 처리한 후 방사선 효과의 상승작용을 알아보고자 하였다. 대상 및 방법 : 자궁경부암 세포주인 HeLa세포에서 EGF 수용체 차단제 AG 1478, 선택적 COX-2 억제제 NS 398과 방사선을 복합 투여하여 세포성장 억제 분석(cell graph inhibition assay)과 세포사멸 분석(apoptosis assay)을 시행하였고, 방사선 감수성 변화를 살펴보기 위해 세포생존 분석(clonogenic survival assay)을 시행하였다. 방사선 감수성 인자로는 2 Gy에서의 세포생존분획($SF_2$)과 linear-quadratic model을 이용한 dose enhancement ratio (DER)를 사용하였다. 방사선 감수성에 대한 작용기전 분석을 위해 flow cytometry로 세포주기 분석(cell cycle analysls)을 시행하였고, western blot 분석을 통하여 bcl-2와 bax 단백질의 발현 변화를 살펴보았다. 결과 : HeLa세포에 NS 398과 AG 1478을 방사선과 함께 복합 투여한 실험 군에서 세포사멸 정도가 가장 높게 나타났다($8.49\%$ vs. $22.70\%$). 세포주기 분석 결과, 방사선과 복합 약물 처리군에서 $G_0/G_l$ 세포주기 정체와 5 세포 분획 소실이 나타났으며 이러한 변화는 72시간 이후까지 지속되었다 세포생존 분석 결과로는 방사선과 AG 1478군에서 $SF_{2}0.68{\pm}0.07$, DER 1.12를 보인 반면, 방사선과 복합약물처리군에서는 $SF_{2}0.12{\pm}0.01,\;DER\;3.00$으로 나타났다. Western blot분석에서는 방사선과 복합약물처리군에서 bcl-2와 bax 단백질 발현이 모두 감소하는 양상을 보였다. 결론 : 신호전달 체계를 억제하는 분자 표적 약제인 선택적 COX-2 억제제와 EGF 수용체 차단제를 방사선과 복합투여함으로써 HeLa세포의 방사선 감수성이 증가됨을 확인하였다.

• The Plant Pathology Journal
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• 제38권1호
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• pp.25-32
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• 2022

Plant pathogens pose major threats on agriculture and horticulture, causing significant economic loss worldwide. Due to the continuous and excessive use of synthetic pesticides, emergence of pesticide resistant pathogens has become more frequent. Thus, there is a growing needs for environmentally-friendly and selective antimicrobial agents with a novel mode of action, which may be used in combination with conventional pesticides to delay development of pesticide resistance. In this study, we evaluated the potentials of lichen substances as novel biopesticides against eight bacterial and twelve fungal plant pathogens that have historically caused significant phytopathological problems in South Korea. Eight lichen substances of diverse chemical origins were extracted from axenic culture or dried specimen, and further purified for comparative analysis of their antimicrobial properties. Usnic acid and vulpinic acid exhibited strong antibacterial activities against Clavibacter michiganensis subsp. michiganensis. In addition, usnic acid and vulpinic acid were highly effective in the growth inhibition of fungal pathogens, such as Diaporthe eres, D. actinidiae, and Sclerotinia sclerotiorum. Intriguingly, the growth of Rhizoctonia solani was specifically inhibited by lecanoric acid, indicating that lichen substances exhibit some degrees of selectivity to plant pathogens. These results suggested that lichen substance can be used as a selective biopesticide for controlling plant disease of agricultural and horticultural significance, minimizing possible emergence of pesticide resistant pathogens in fields.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.52.2-52.2
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• 2011

Flat form technology for constructing anticancer loaded multi-walled carbon nanotubes (mwCNTs) was introduced in this study. Conventional anticancer drugs, such as MTX (Methotrexate), cisplatin, DOX (Doxorubicin hydrochloride), DAU (Daunorubicin) and EPI (epirubicin) were bio-conjugated with folic acid (FA) for selective targeting tumor cells. Loading efficiencies of the used anticancer drugs on mwCNTs have shown different order of bindings depending on the molecular bind affinity of NH (amine) formation on mwCNTs. MTT assays have shown increased selective target efficiency of FA conjugated mwCNTs on breast cancer cell growth inhibition. All results collectively indicated promising application of mwCNTs as a smart inorganic nanomaterial for selective targeting drug delivery vehicle at tumor tissues.

• 한국미생물·생명공학회지
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• 제37권3호
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• pp.238-242
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• 2009

분자생물학적 방법에 의한 김치유산균 연구의 진행으로 Leuconostoc, Lactobacillus, Weissella 속 유산균의 김치발효 과정 중 생육에 대한 새로운 결과들이 도출되었지만, Pediococcus속의 생육에 대한 새로운 결과는 거의 보고되지 않았다. 본 연구에서는 김치에 존재하는 Pediococcus 속 유산균의 존재에 대한 재조명을 위하여 ampicillin (A)의 첨가로 pediococci의 선발 유효성이 향상된 것으로 보고된 pediococci selective medium(PSM)+A를 이용하여 pediococci 선택적 검출의 유효성을 검토한 결과, 기존에 보고된 결과와는 달리 Pediococcus pentosaceus 외에도 leuconostocs, Lactobacillus casei, Lactobacillus curvatus, Oenococcus oeni, Streptococcus thermophilus에 대한 생육저해가 발생하지 않았다. PSM+A 한천배지를 이용하여 김치에 생육하는 미생물을 검출한 경우, leuconostocs, P. pentosaceus, Weissella koreensis, Lb. curvatus, Lactobacillus brevis, Lactobacillus sakei가 생육하여 김치와 같은 발효침채류의 발효에 관여하는 pediococci의 선택적 선발에는 PSM+A가 유효하지 않은 것으로 확인되었다.

• 한국식품영양과학회지
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• 제32권5호
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• pp.758-763
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• 2003

구강 편평 세포암종 KB 세포를 이용하여 아미노산 수송계 L억제제인 BCH의 세포 성장억제에 미치는 효과를 밝히기 위해, KB세포에서 uptake실험, MTT분석 및 DNA frag-mentation분석 등을 시행하여 다음과 같은 결과를 얻었다. KB 세포에서는 아미노산 수송계 L 중에서 LAT1과 그 보조인자 4F2hc를 통해 BCH및 중성 아미노산들이 수송되었다. BCH는 시간과 농도에 의존적으로 KB세포의 성장을 억제시켰다. BCH를 처리한 실험군에서 DNA fragmentation 현상은 볼 수 없었다. 본 연구의 결과로서 구강암 세포주인 구강 편평세포암종 KB 세포에서 LAT1과 그 보조인자 4F2hc를 통해 BCH및 중성 아미노산의 수송이 이루어지고 있다는 것을 확인할 수 있었으며 BCH는 이 LAT1을 차단하여 중성 아미노산들의 세포 내 고갈을 유도함으로서 KB 세포 성장의 억제를 유도하는 것으로 사료된다.

• Archives of Pharmacal Research
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• 제25권6호
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• pp.759-769
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• 2002

Mutated forms of ras are found in many human tumors and the rate of incidence is significantly higher in colon and pancreatic cancers. The protein product from the ras oncogene is a small G-protein, $p21^{ras}{\;}(Ras)$ that is known to playa key role in the signal transduction cascade and cell differentiation and proliferation. Mutated Ras is unable to regulate itself and remains constantly activated, leading to uncontrolled cell growth. The function of Ras in signal transduction requires its location near the growth factor receptor at the cell membrane. However, Ras does not have a transmembrane domain. Ras requires farnesylation to increase its hydrophobicity and subsequent plasma membrane association for its transforming activity. This key post-translational modification is catalyzed by the enzyme Ras farnesyltransferase (FTase), which transfers a farnesyl group from farnesylpyrophosphate to the C-terminal cysteine of the Ras protein. The requirement has focused attention on FTase as a target for therapeutic intervention. Selective inhibition of FTase will prevent Ras protein from association with the plasma membrane, leading to a disruption of oncogenic Ras function.

• 약학회지
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• 제43권1호
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• pp.104-110
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• 1999

We investigated effects of methanol extract of Aloe vera on anticancer drugs(cisplatin, mitomycin C, 5-fluorouracil)-induced growth inhibition in p388, L1210, HCT-15, SK-HepG-1 as cancer cell lines and mouse splenocytes as a normal cell by MTT assay, respectively. We also examined the effects of aloe extract and mitomycin C on the mitogen(Con, A, LPS)-induced splenocyte proliferation. Aloe extract(0.25 mg/m , 1.25 mg/m , 2.5 mg/m , 5.0 mg/m ) showed dose-dependently selective cytotoxicity against the cancer cell lines. In contrast, Aloe extract increased the growth and proliferation of the normal mouse splenocytes. The combination of aloe extract with anticancer drugs showed an additive effect for the cytotoxicity against cancer cell lines. However, that combination reduced clealy the anticancer drugs-induced toxicity against the normal mouse splenocytes.