• The Korean Journal of Physiology and Pharmacology
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• 제7권1호
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• pp.9-14
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• 2003

Recent studies indicated that cancer cells become resistant to ionizing radiation (IR) and chemotherapy drugs by enhanced DNA repair of the lesions. Therefore, it is expected to increase the killing of cancer cells and reduce drug resistance by inhibiting DNA repair pathways that tumor cells rely on to escape chemotherapy. There are a number of key human DNA repair pathways which depend on multimeric polypeptide activities. For example, Ku heterodimer regulatory DNA binding subunits (Ku70/Ku80) on binding to double strand DNA breaks (DSBs) are able to interact with 470-kDa DNA-dependent protein kinase catalytic subunit (DNA-PKcs), and are essential for DNA-dependent protein kinase (DNA-PK) activity. It has been known that DNA-PK is an important factor for DNA repair and also is a sensor-transmitting damage signal to downstream targets, leading to cell cycles arrest. Our ultimate goal is to develop a treatment of breast tumors by targeting proteins involved in damage-signaling pathway and/or DNA repair. This would greatly facilitate tumor cell cytotoxic activity and programmed cell death through DNA damaging drug treatment. Therefore, we designed a domain of Ku80 mutants that binds to Ku70 but not DNA end binding activity and used the peptide in co-therapy strategy to see whether the targeted inhibition of DNA-PK activity sensitized breast cancer cells to irradiation or chemotherapy drug. We observed that the synthesized peptide (HNI-38) prevented DNA-PKcs from binding to Ku70/Ku80, thus resulting in inactivation of DNA-PK activity. Consequently, the peptide treated cells exhibited poor to no DNA repair, and became highly sensitive to IR or chemotherapy drugs, and the growth of breast cancer cells was inhibited. Additionally, the results obtained in the present study also support the physiological role of resistance of cancer cells to IR or chemotherapy.

• 멤브레인
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• 제13권3호
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• pp.162-173
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• 2003

폴리아닐린(polyaniline, PANI)과 도판트인 camphorsulfonic acid(CSA), dodecyl benzene sulfonic acid(DBSA)와 의몰비 변화에 따라 가상 n형 PANI을 제조하였다. FT-IR측정으로부터 도핑유무를 확인하였고, indium thin oxide(ITO)에 코팅하여 제조한 전극에 대해, 순환전압전류법과 교류임피던스법을 이용하여 도판트의 영향을 조사하였다. FT-IR과 순환전압전류법으로부터, 제조된 전극이 양이온의 도핑-탈도핑이 일어나는 가상 n형의 특성을 가짐을 확인하였다. 순환전압전류법에서 산화-환원 피크전류값은 PANI/DBSA에 비하여 PANI/CSA가 약 5 배정도 더 큰 결과를 보였다. 교류임피던스법으로부터, 두 전극 모두 이상적인 Randles의 등가회로와 유사한 거동을 보였다. 전하이동저항은 PANI/CSA에서 $1.14~1.09 k{\Omega}$으로 거의 일정한 값을 보였고, PANI/DBSA는 DBSA 몰 비에 증가에 따라 $27.73{\sim}8.37K{\Omega}$으로 감소하여 나타났다. 이중층용량 또한 PANI/CSA는 $13.47{\sim}14.59 {\mu}F$으로 거의 일정하였으나, PANI/DBSA는 DBSA 몰 비 증가에 따라 $0.49{\sim}l.20 {\mu}F$으로 증가를 보였다. 결과적으로 PANI/CSA의 전기적 특성이 더 좋았으나, 도판트의 몰 비 증가에 따른 특성은 PANI/CSA 전극은 거의 일정하였고, PANI/DBSA 전극은 전기적 활성이 좋아짐을 알 수 있었다.

• 한국육종학회지
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• 제40권4호
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• pp.479-483
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• 2008

"호서"는 마늘 후작에 적합한 조숙 소립을 목표로 농촌진흥청 국립식량과학원에서 육성한 나물콩 품종으로 주요특성을 요약하면 다음과 같다. 1. "호서"는 유한형으로 꽂색은 자색, 엽형은 타원형, 모용색은 회색이며, 성숙협색은 담갈색, 종피색은 황색, 배꼽색은 담갈색으로 입형은 구형이다. 2. 성숙기는 9월 27일로 풍산나물콩보다 12일 빠르며, 100립중이 7.4 g으로 소립종이다. 3. "호서"는 도복에 강하고, 콩 모자이크병 중 괴저병에 강하며 세균성불마름병과 검은뿌리 썩음병에 강한 품종이다. 4. "호서"의 종실 조단백질 함량은 대비품종인 풍산나물콩에 비해 높으며, 콩나물의 기능 성분인 아이소플라본, 총 아미노산 함량은 비슷하나 숙취해소에 효과가 있는 아스파라진 함량은 높은 양질의 나물용 콩이다. 5. "호서"의 콩나물 생육은 풍산나물콩에 비해 경실종자가 없으며, 배축신장성이 우수하여 콩나물 수율이 6%증수되는 양질의 나물용콩이다. 6. "호서"의 ha당 수량성은 2005~2007년까지 3년간 실시한 지역적응시험 결과 평균 수량이 2.51톤으로 풍산나물콩 대비 89% 수준으로 비교적 수량은 낮은 품종이다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2672-2678
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• 2011

철도차량의 차체 구조는 초기의 전(全) 목제에서 강제 후레임과 목제 차체의 조합, 리벳으로 결합한 전(全)강제차체, 전(全) 용접결합의 모노코크(monocoque)차체로 변천해 왔다. 구체의 재료 또한 Mild Steel이 많이 사용되어 왔으나, 가볍고 내식성이 우수한 경량 스테인레스 구체와 알루미늄 구체의 적용 비율이 급격히 높아지고 있다. 구조적으로는 종래의 골조와 외판으로 구성된 싱글 스킨 구조인 SSD (Sheet_Stringer Design)에서, 알루미늄 구체와 같이 대형 중공압출형재로 구성된 전(全)더블스킨 구조인 AED(All Extrusion Design)가 실용화되고 있다. 종래의 알루미늄 차체는 소형 압출재로 제작되어 용접에 의한 열영향을 받는 범위가 매우 크고 매우 취약한 특성 때문에 나타나는 용접결합 부분의 강성 저하가 많은 문제점을 일으켰다. 본 연구에서는 확장형 알루미늄 압출형재를 사용하여 부재 수를 감소시킴으로서 용접 공수를 줄이고 결합부의 용접 집중을 최소화 하여 품질 및 차체 강성을 향상 시킬 수 있는 방안을 제시하였다.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.492-498
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• 2012

A hyper branched 10-butylphenothiazine with in-situ thermally curable methacrylate (1,3,5-tris-[$\{$10-Butyl-3-(4-(2-methyl-acryloyloxy)-phenyl)-7-yl-10H-phenothiazine$\}$]-benzene, (tris-PTMA)) was synthesized successfully. From the TGA thermogram of tris-PTMA was thermally stable up to $336^{\circ}C$. In the first heating scan of DSC thermogram, tris-PTMA showed glass transition temperature (Tg) at $140^{\circ}C$ and broad endothermic process in the region of $144-179^{\circ}C$, which is thermally curing temperature. In the second heating process, $T_g$ exhibited at $158.7^{\circ}C$ and endothermic process was not observed. Thermally cured tris-PTMA showed no big change in the UV-visible spectrum after washing with organic solvent such as methylene chloride, chloroform, toluene, indicating that thermally cured film was very good solvent resistance. Thermally cured tris-PTMA was electrochemically stable and the HOMO energy level of tris-PTMA was -5.54 eV. The maximum luminance efficiency of double layer structured polymer light-emitting diode based on in-situ thermally cured tris-PTMA was 0.685 cd/A at 16.0 V, which was higher than that of the device without thermally cured tris-PTMA (0.348 cd/A at 15.0 V).

• 대한심미치과학회지
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• 제24권2호
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• pp.101-121
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• 2015

지르코니아 폴리크리스탈은 (Y-TZP) 다른 치과용 세라믹에 비해 기계적 강도와 파절저항성이 우수하다. 지르코니아 기반 세라믹은 캐드캠 시스템을 바탕으로 고정식 수복물 제작에 성공적으로 소개되어 왔다. 이는 고정식 수복물을 위한 금속 구조물의 임상적 대안으로 제시되었다. 지르코니아 수복물의 가장 흔한 합병증은 상부 도재의 파절이다. 다른 옵션은 고도로 반투명한 지르코니아를 전부지르코니아 고정식 수복물로 사용하는 것이다. 본 논문에서는 전부지르코니아 수복물의 장점, 지르코니아 수복물의 임상적용, 지대치 삭제, 대합치 마모, 지르코니아와 레진시멘트와의 접착, 그리고 기공소와의 의사소통에 관하여 보고하였다.

• Corrosion Science and Technology
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• 제14권3호
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• pp.120-126
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• 2015

The usage of bending products recently have increased since many industries such as automobile, aerospace, shipbuilding, and chemical plants need the application of pipings. Bending process is one of the inevitable steps to fabricate the facilities. Induction heat bending is composed of compressive bending process by local heating and cooling. This work focused on the effect of induction heat bending process on the properties of ASME SA312 Gr. TP304 stainless steel pipes. Tests were performed for base metal and bended area including extrados, intrados, crown up, and down parts. Microstructure was analyzed using an optical microscope and SEM. In order to determine intergranular corrosion resistance, Double Loop Electrochemical Potentiokinetic Reactivation (DL-EPR) test and ASTM A262 practice A and C tests were done. Every specimen revealed non-metallic inclusion free under the criteria of 1.5i of the standard and the induction heat bending process did not affect the non-metallic inclusion in the alloys. Also, all the bended specimens had finer grain size than ASTM grain size number 5 corresponding to the grain sizes of the base metal and thus the grain size of the pipe bended by induction heat bending process is acceptable. Hardness of transition start, bend, and transition end areas of ASME SA312 TP304 stainless steel was a little higher than that of base metal. Intergranular corrosion behavior was determined by ASTM A262 practice A and C and DL-EPR test, and respectively step structure, corrosion rate under 0.3 mm/y, and Degree of Sensitization (DOS) of 0.001~0.075% were obtained. That is, the induction heat bending process didn't affect the intergranular corrosion behavior of ASME SA312 TP304 stainless steel.

• The Plant Pathology Journal
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• 제33권1호
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• pp.95-100
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• 2017

Fungicide-resistant Alternaria alternata impede the practical control of the Alternaria diseases in crop fields. This study aimed to investigate cytological fungicide resistance mechanisms of A. alternata against dicarboximide fungicide iprodione. A. alternata isolated from cactus brown spot was cultured on potato-dextrose agar (PDA) with or without iprodione, and the fungal cultures with different growth characteristics from no, initial and full growth were observed by light and electron microscopy. Mycelia began to grow from one day after incubation (DAI) and continued to be in full growth (control-growth, Con-G) on PDA without fungicide, while on PDA with iprodione, no fungal growth (iprodione-no growth, Ipr-N) occurred for the first 3 DAI, but once the initial growth (iprodione-initial growth, Ipr-I) began at 4-5 DAI, the colonies grew and expanded continuously to be in full growth (iprodione-growth, Ipr-G), suggesting Ipr-I may be a turning moment of the morphogenetic changes resisting fungicidal toxicity. Con-G formed multicellular conidia with cell walls and septa and intact dense cytoplasm. In Ipr-N, fungal sporulation was inhibited by forming mostly undeveloped unicellular conidia with degraded and necrotic cytoplasm. However, in Ipr-I, conspicuous cellular changes occurred during sporulation by forming multicellular conidia with double layered (thickened) cell walls and accumulation of proliferated lipid bodies in the conidial cytoplasm, which may inhibit the penetration of the fungicide into conidial cells, reducing fungicide-associated toxicity, and may be utilized as energy and nutritional sources, respectively, for the further fungal growth to form mature colonies as in Ipr-G that formed multicellular conidia with cell walls and intact cytoplasm with lipid bodies as in Con-G.

• 대한수의학회지
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• 제29권3호
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• pp.315-324
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• 1989

In order to establish the extent of Streptococcal arthritis piglets, isolation of Streptococci from arthritic lesions of 34 piglets were undertaken from November 1987 to October 1988 in Korea. Also determined were isolation frequency of Streptococci in nasal cavity of 250 healthy sows and antibiotic susceptibilities of the isolates. Streptococci were isolated from 52.9% of 34 arthritic piglets and 20 strains isolated belonged to 4 S suis type I, 8 S suis type II, 2 Lancefield group C and 6 group E. From 28.8% of 250 healthy sows, 72 strains of Streptococci were isolated and these consisted of 9 S suis type I, 51 S suis type II and 12 group C. Streptococcal arthritis seemed to occur prominently in piglets aged 2 to 4 weeks and in male than female. No significant difference were recognized in tarsal and carpal joints as affecting site. All of 92 isolates were sensitive to ampicillin and penicillin, and all strains of S suis type I and group E Streptococcus were also sensitive to chloramphenicol and cephalothin. To cephalothin all strains of group C Streptococcus were sensitive. The 1. 7 to 100% of 92 isolates were resistant with different prevalence to colistin, erythromycin, kanamycin, tetracycline, gentamicin, chloramphenicol and cephalothin. The 92.5% of these resistant Streptococci were multiply drug-resistant strains. The drug resistant patterns most frequently encountered were Tc Cl Em Km Gm(16.3%) in quintuple pattern, Tc Cl Em Km(16.3%) in quadruple pattern, Tc Cl Em(10.9%) in triple pattern and Cl Em(14.1%) in double pattern.

• 한국정보통신학회논문지
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• 제4권3호
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• pp.705-711
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• 2000

반도체 제조공정과 미세가공 기술을 이용하여 $300^{\circ}C$의 동작온도에서 약 60 mW의 전력소모를 갖는 산화물 반도체 박막 가스센서 어레이를 제조하였다. 멤브레인의 우수한 열적 절연은 $0.1\mum\; 두께의\; Si_3N_4와\; 1\mum$ 두께의 PSG의 이중 층에 의한 것으로, 각각 LPCVD(저압화학 기상증착)와 APCVD(대기압 화학 기상증착)에 의해 제조되었다. 센서 어레이의 4가지 산화물 반도체 박막 감지물질로는 1 wt.% Pd가 도핑된 $SnO_2,\; 6 we.% A1_2O_3$가 도핑된 ZnO, $WO_3$, ZnO를 이용하였으며,4가지 감지물질의 베이스라인 저항은 $300^{\circ}C$ 에서 3일 동안의 에이징을 거친 후 안정됨을 보였다. 제조된 초소형 산화물 반도체 박막 가스센서 어레이는 여러 가지 가스의 노출 시 유용한 저항 변화를 나타내었으며 감도는 감지 물질에 강하게 의존함을 알 수 있었다.