담배나방과 파밤나방의 유충사망률과 cytochrome P-450 monooxygenases의 활성에 미치는 니코틴과 다이아지논의 영향

J.H. Lee,K.S. Boo 한국응용곤충학회 1993 한국응용곤충학회지 Vol.32 No.2

담배나방(Heliocoverpa assulta)와 파밤나방(Spodoptera exigua)유충에 대한 유기인계 살충제인 다이아지논과 담배의 산물인 니코틴의 영향을 조사하기 위하여 본 실험을 시행하였다. 다이아지논이 처리된 담배나방유충의 사망률은 파밤나방유충의 경우보다 훨씬 높았으며 니코틴 처리구에서는 이와 반대양상을 나타내었다. 담배나방유충 중장의 cytochrome P-450 monooxygenases (MFO) 활성은 다이아지논 처리구에 비해서 니코틴 처리구에서 더욱 높게 나타났다. 담배나방유충을 기주식물인 담배잎으로 사육하였을 때 다른 화합물과는 달리 대부분의 니코틴은 변화 없이 배설되었다. This study was carried out to investigate effects of diazinon, an organophosphate, and nicotine, a plant~originated toxic chemical, on larval mortality and activity of cytochrome P-45D monooxygenases, a major detoxifwation enzyme system, in Helicoverpa assulta and Spodoptera exigua. Diazinon treatment gave a higher mortaliLy to H. assulta larvae than S. exigua larvae. In contrast to the case of diazinon, nicotine caused a higher mortahty to S. exigua than to H. assulla larvae. It was partly due to the fact that nicotine induced the actiVIty of midgut cytochrome P-450 monooxygenases (MFO) more than diazinon did in If assulta larvae. When If. aSSlllta larvae were reared on their host p\am. NicotwlIa tuoocum leaves, other componentS were mostly metabolized with the exception of dietary nicotine.

먹이종류에 따른 몇가지 곤충의 MFO활성 비교

J. H. Lee,K. S. Boo 한국응용곤충학회 1993 한국응용곤충학회지 Vol.32 No.3

네가지 종류의 곤충 중장에 있는 주요 해독효소인 cytochrome P-450 monooxygenases의 활성을 그들의 먹이종류 및 섭식여부와 연관시켜 분석하였다. 담배나방유충을 인공사료로 사육하였을 때 전반적으로 중장의 cytochrome P-450 monooxygtenases(MFO)활성이 지방체의 경우보다 3배가량 높게 나타났다. 고추열매나 인공사료를 공급하여 사육하였을 때보다 담배잎으로 사육하였을 때 담배나방유충의 중장 MFO는 훨씬 높게 나타났으며, 흰불나방의 경우염주나무잎이 MFO활성을 가장 높게 유기했다. 담배나방, 파밤나방, 희불나방, 담배거세미나방 등의 유충들을 각각의 인공사료로 사육하였을 때 광식성이며 동시에 살충제저항성을 보유하고 있는 파밤나방의 MFO활성이 가장 높게 나타났다. Midgut tissues from 4 insect specIes were exammed for the activity of cytochrome P-450 monooxygenases, a major enzyme involved in chemical detoxification. When Helicoverpa assulta larvae were reared on an artificial d, et, the specific activity of the midgut cytochrome P-450 monooxygenases (MFO) was :3 times higher than that of the fat body, The specific activity of the midgut cytochrome P-450 monooxygenases was higher in H. assul/a larvae when reared on Nicotiana tabacum leaves than when on CapsIcum annuum fruits or an artificial diet. In the case of Hyphantria cunea larvae, Tilia megaphyllo leaves were the best in inducing midgut cytochrome P-450 monooxygenases activity. When larvae of H. assulta, Spodoptera exigua, H. cunea and Spodoptera litura were reared on their own artificial diet, the highest activity was seen in S. exigua larvae which is a polyphagous and insecticide-resistant strain.

W(110) 표면에 CO와 O_2의 공동흡착

이경희,한현석,윤효근,부진효,이순보,곽현태 성균관대학교 기초과학연구소 1998 論文集 Vol.49 No.-

The coadsorption of CO and O₂ on W(110) surface was studied by LEED, TDS, and photoelectron spectroscopy. In the TDS for the coadsorption of CO at RT on O₂ precovered W(110) surface, two CO desorption states were observed at about 400 and 1150 K, called α and β , respectively. The β-CO spectra with second order desorption kinetics were shifted to lower desorption temperature as increasing the amount of preadsorbed atomic oxygen on the W(110). Moreover, the β-CO spectra were gradually increased with increasing the amount of preadsorbed oxygen to 0.5 ML. Even though a (2 x 1) LEED pattern appeared during oxygen adsorption at RT and 1-3 L oxygen exposures, we didn't observe any new pattern induced by CO in this study. Only the structure of c(11 x 5) was obtained at temperature in the range of 800-1100 K. These results indicated that there were interaction between CO and O and thereby the β-CO might riot be dissociated even at the higher temperature than 800 K. By using the XPS and UPS, it was also confirmed that the coadsorbed β-CO at 900 K doesn't dissociate as the experimental results of the adsorption of pure CO on W(110) surface at the same temperature. According to the valence band spectra, two CO peaks at near -10.7 eV (4σ) and -7.0 eV (5σ+1π) were observed, indicating molecular CO adsorption on the oxygen preadsorbed surface at RT. Even heating the coadsorbed surface to 900 K, we could also detect the CO 4σ peak which can be an important factor for identifying a contribution of the CO 4σ molecular orbital to the CO-metal bond. To our best knowledge, this is the first report and quite contradictory result to that reported previously.

Effects of annealing on ion-implanted Si for interdigitated back contact solar cell

Kang, M.G.,Lee, J.H.,Boo, H.,Tark, S.J.,Hwang, H.C.,Hwang, W.J.,Kang, H.O.,Kim, D. Elsevier 2012 CURRENT APPLIED PHYSICS Vol.12 No.6

Effects of annealing on the properties of P- and B-implanted Si for interdigitated back contact (IBC) solar cells were investigated with annealing temperature of from 950 to 1050 <SUP>o</SUP>C. P-implanted samples annealed at 950 <SUP>o</SUP>C were enough to activate dopants and recover the damage by implantation. As the annealing temperature was increased, the diode properties of P-implanted samples were degraded, while that of B-implanted samples were improved. However, in order to activate an implanted B ion, B-implanted samples needed an annealing of above 1000 <SUP>o</SUP>C. The implied V<SUB>oc</SUB> of lifetime samples by quasi-steady-state photoconductance decay followed the trend of diode properties on annealing temperature. Finally, IBC cell was fabricated with a two-step annealing at 1050 <SUP>o</SUP>C for B of the emitter and 950 <SUP>o</SUP>C for P of the front and back surface fields. The IBC cell had V<SUB>oc</SUB> of 618 mV, J<SUB>sc</SUB> of 35.1 mA/cm<SUP>2</SUP>, FF of 78.8%, and the efficiency of 17.1% without surface texturing.

태양열 집열기용 히트파이프의 열전달 성능

부준홍,정원복,곽희열 한국 항공대학교 항공산업기술연구소 2001 航空宇宙産業技術硏究所 硏究誌 Vol.11 No.-

A slab-wick heat pipe was fabricated and tested for applications where the condenser temperature in the range of 80 to 120℃. The pipe material in the evaporator section and adiabatic section was 9.53 mm O.D. copper tube and 25.4 mm O.D. copper tube was adapted in condenser section. The working fluids were ethanol and distilled water. The total length of the heat pipe was 1.6 m in which evaporator section was 1500 mm and the condenser was 50 mm. The slab was a composite wick structure fabricated with stainless steel wire screens. The temperature of coolant and inclination angle were varied with applied thermal load. The result of experiment was compared with a heat pipe having same diameters through the whole length. The maximum thermal load was 160 W in and 480 W the case of ethanol and water, respectively. This was 2.4 times of ordinary 9.53 mm O.D heat pipe. The thermal performance of the slab-wick heat pipe was analysed and discussed in terms of maximum thermal load and thermal resistance against coolant temperature and thermal load.

Twisted Wire를 사용한 미소 히트파이프의 성능

부준홍,김동근 한국 항공대학교 항공산업기술연구소 1999 航空宇宙産業技術硏究所 硏究誌 Vol.9 No.-

전자부품 냉각용 미소 히트파이프의 열적 성능을 조사하기 위해 내부 삽입물로 꼬은 와이어를 갖는 구리 히트파이프에 대한 실험을 수행하였다. 미소 히트파이프의 작동 유체로는 물과 아세톤을 이용하였으며, 이 파이프들의 직경은 3mm이고 전체 파이프 길이는 300mm이다. 작동유체 충전량, 열부하, 와이어 피치, 삽입된 와이어의 개수, 경사각 등을 성능에 대한 중요한 요인으로 고려하였다. 온도 특성을 분석하였으며, 실험 자료들로부터 최적의 충전량을 확인하였다. 본 논문에서 미소 히트파이프가 감당하는 최대 열부하는 물과 아세톤을 작동유체로 하는 경우에 대해 각각 10W와 8W로 나타났다. A series of experiments was conducted with a copper heat pipe having twisted-wire inserts to investigate the thermal performance of miniature heat pipes for electronics cooling. Acetone and water were used as working fluids for the miniature heat pipes, of which the diameter was 3 mm and the total length was 300 mm. Fluid charge, thermal load, pitch of wire twist, number of inserted wires and inclined angle were considered as important performance factors. Temperature characteristics was analysed and the optimal limquid charge values were found from the experimental data. The maximum thermal load of the miniature heat pipe were 10 W and 8 W for acetone and water, respectively.

터보팬 엔진의 성능해석과 예비설계를 위한 사용자 편의 프로그램 개발

김도형,부준홍 한국항공대학교 1998 論文集 Vol.36 No.-

터보팬 엔진은 현재까지 실용화된 항공기용 엔진 중에서는 가장 진보된 형태로서 많은 장점이 있는 반면, 구조와 메카니즘이 여타의 엔진 형태보다 복잡하므로 성능예측과 설계 및 제작에 있어 상대적으로 난이도가 높은 과정들을 포함하고 있다. 적절한 엔진을 선정하여 항공기에 채용하는 입장이나 개발하는 입장을 막론하고 이러한 엔진의 성능에 대한 정량적 이해는 기본해석과 엔지니어링 및 설계에 필수적이다. 터보팬 엔진의 성능해석을 다루기 위해 개발된 기존의 전산 프로그램들은 일반 사용자들이 편리하게 이용할 수 있는 환경과 절차가 미흡한 실정이다. 더구나, 반복계산이 많이 필요한 경우에는 보다 간편한 규모로 이용하기 용이한 프로그램이 필요하다. 본 연구에서는 대학과정 관련 과목의 전문 지식을 바탕으로 학생, 연구자 또는 현장의 기술자가 필요로 하는 계산을 용이하게 수행할 수 있도록 사용자 편의를 위주로 개인용 컴퓨터에서 사용할 수 있는 프로그램의 개발을 수행하였다. 개발된 전산 프로그램에는 설계점 성능해석과 탈설계점의 성능해석 과정이 포함되었다. While turbofan engines have many advantages as the most advanced type of aircraft engines developed thus far, they include relatively difficult procedures in performance prediction, design, and manufacturing due to complex structures and mechanisms. Either in the case of selecting a proper engine for a pre-defined aircraft or in the case of developing an engine itself, a quantitative understanding of the engine is required for basic analysis, engineering and design. A convenient environment and procedure are not provided in existing computer programs previously developed for the performance calculation of turbofan engines. Moreover, when a calculation involves lots of iteration procedure, a handy and user-friendly program is much desired. A user-friendly program was developed through this study, based on college-level engineering knowledges so that students, researchers, or engineers can conduct necessary calculations with ease on personal computers. The computer program developed in this study includes design-point and off-design performance analyses.

CD82/KAI1 Maintains the Dormancy of Long-Term Hematopoietic Stem Cells through Interaction with DARC-Expressing Macrophages

Hur, J.,Choi, J.I.,Lee, H.,Nham, P.,Kim, T.W.,Chae, C.W.,Yun, J.Y.,Kang, J.A.,Kang, J.,Lee, S.,Yoon, C.H.,Boo, K.,Ham, S.,Roh, T.Y.,Jun, J.,Lee, H.,Baek, S.,Kim, H.S. Cell Press 2016 Cell stem cell Vol.18 No.4

<P>Hematopoiesis is regulated by crosstalk between long-term repopulating hematopoietic stem cells (LT-HSCs) and supporting niche cells in the bone marrow (BM). Here, we examine the role of CD82/ KAI1 in niche-mediated LT-HSC maintenance. We found that CD82/ KAI1 is expressed predominantly on LT-HSCs and rarely on other hematopoietic stem-progenitor cells (HSPCs). In Cd82 +/-/+/- mice, LTHSCs were selectively lost as they exited from quiescence and differentiated. Mechanistically, CD82based TGF-b1/ Smad3 signaling leads to induction of CDK inhibitors and cell-cycle inhibition. The CD82 binding partner DARC/ CD234 is expressed on macrophages and stabilizes CD82 on LT-HSCs, promoting their quiescence. When DARC + BMmacrophages were ablated, the level of surface CD82 on LT-HSCs decreased, leading to cell-cycle entry, proliferation, and differentiation. A similar interaction appears to be relevant for human HSPCs. Thus, CD82 is a functional surface marker of LT-HSCs that maintains quiescence through interaction with DARC-expressing macrophages in the BM stem cell niche.</P>

Effects of dihydrotestosterone on rat dermal papilla cells in vitro

Kang, J.I.,Kim, S.C.,Kim, M.K.,Boo, H.J.,Kim, E.J.,Im, G.J.,Kim, Y.H.,Hyun, J.W.,Kang, J.H.,Koh, Y.S.,Park, D.B.,Yoo, E.S.,Kang, H.K. North-Holland ; Elsevier Science Ltd 2015 european journal of pharmacology Vol.757 No.-

Androgenetic alopecia involves the action of dihydrotestosterone (DHT) on dermal papilla cells (DPCs) that line the base of the hair follicle. However, the mechanism of DHT action is not completely understood. The effects of DHT on DPCs, regulatory cells that function in follicle growth and the hair cycle, were examined in immortalized cells derived from rat vibrissa follicles. DHT did not affect the proliferation of immortalized DPCs. However, flow cytometry analysis revealed that DHT increased cell-cycle arrest in these cells, which was accompanied by an increase in the p27<SUP>kip1</SUP> level and by decreases in cyclin E, cyclin D1, and cyclin-dependent kinase 2 levels. DHT treatment resulted in the phosphorylation and nuclear translocation of Smad2/3, a mediator of the transforming growth factor-β (TGF-β) signaling pathway, which leads to the catagen phase of the hair cycle. DHT also induced the phosphorylation and nuclear translocation of heat shock protein 27 (HSP27). Moreover, DHT decreased the levels of total and nuclear β-catenin, an important regulator of hair growth and proliferation, while lithium chloride, a glycogen synthase kinase-3β inhibitor, attenuated the DHT-induced downregulation of the β-catenin level. On the other hand, DHT increased the phosphorylation of mammalian target of rapamycin (mTOR), a regulator of proliferation, in immortalized DPCs. These results illustrate that DHT could shorten the duration of the hair growth cycle by initiating cell-cycle arrest, downregulating the β-catenin level, and upregulating the TGF-β/Smad and HSP27 level, whereas activation of mTOR by DHT could attenuate the inhibition of hair growth cycle in immortalized DPCs.

A novel antitumor activity of deguelin targeting the insulin-like growth factor (IGF) receptor pathway via up-regulation of IGF-binding protein-3 expression in breast cancer

Suh, Y.A.,Kim, J.H.,Sung, M.A.,Boo, H.J.,Yun, H.J.,Lee, S.H.,Lee, H.J.,Min, H.Y.,Suh, Y.G.,Kim, K.W.,Lee, H.Y. Elsevier Science Ireland 2013 Cancer letters Vol.332 No.1

In this study, we investigated the antitumor effects of deguelin in several human breast cancer cells in vitro and in vivo. Deguelin inhibited cell viability and the anchorage-dependent and anchorage-independent colony formation of triple-negative (MDA-MB-231 and MDA-MB-468) and triple-positive (MCF-7) breast cancer cells, and it significantly reduced the growth of MCF-7 cell xenograft tumors. The induction of apoptosis, inhibition of insulin-like growth factor-1 receptor (IGF-1R) signaling activation, and up-regulation of IGF-binding protein-3 (IGFBP-3) expression may be associated with deguelin-mediated antitumor effects. Our findings suggest a potential therapeutic use for deguelin in patients with triple-negative breast cancer and for those with breast cancers who are sensitive to endocrine- and HER2-targeted therapies.