• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.301-301
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• 1994

〔$^3$H〕Ouabain binding parameters(K$\_$D/ and B$\_$max/,) in homogenates prepared fpom control rat ventricular strip and Langendorff preparations which were not previously exposed to ouabain were compared to those in homogenates from ventricular strip and Langendorff preparations that had been first exposed to a complete ouabain dose-response curve(10$\^$-7/M to 10$\^$-4/ M). In rat ventricular strips and Langendorff perfused rat heart preparations, cumulative dose-response cruves of ouabain revealed biphasic positive inotropic effects, a "low-dose" and a "high-dose" effect with ED$\_$50/ values of 0.5${\mu}$M and 35${\mu}$M ouabain, respectively- The "low-dose" effect in rat ventricular strips disappeared or was diminished significantly when the ouabain dose-response curve wag repeated after the washout of the effects of the first curve, whereas the maximal "high-dose" effect was identical in both exposures to oubain. However, there was no change in the "low-dose" effects in both sets of the Langendorff perfused hearts. The contractile activity of the pre-exposed strips did not indicate the presence of residual ouabain since their basal contractile force was decreased 10% compared to initial control. 〔$^3$H〕Ouabain binding parameters, K$\_$D/ and B$\_$max/, were not changed comparing homogenate of control ventricular strips with that of strips pre-exposed to ouabain. These results suggest that digitalis receptor desensitization in the rat ventricular strip may due to the change of post-receptor events induced by ouabain binding to a high affinity site(${\alpha}$$_2$ isoform).

• Journal of Microbiology and Biotechnology
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• v.15 no.4
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• pp.734-739
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• 2005

Myxobacterium sp. HK1, isolated from Korean soil, degrades cellulose, differentiates to fruiting body, and its 16s rDNA has $95\%$ similarity to Polyangium sp. An anticancer molecule, CDMHK, was identified from culture broth of Myxobacterium sp. HK1, and purified by Diaion HP20, Silica gel, Sephadex LH-20 chromatography, and preparative HPLC using an YMC OSD-A C18 column. The molecular structure and formula were determined to be $C_{l2}H_{l9}N_3O_2$ (M.W 237) by MS spectrometry, 300 MHz $^{1}H\;and\;^{13}C$ NMR. The CDMHK was not active against Escherichia coli, Staphylococcus aureus, and Candida albicans. However, this molecule inhibited the growth of various cancer cell lines. The $ED_{50}$ values of CDMHK were determined to be 0.147, 0.086, 0.18, 0.166, and 0.142 $\mu$g/ml against A549, SK-OV-3, SK-MEL-2, VF498, and HCTl5 cancer cell lines, respectively. In addition, the CDMHK was able to induce apoptosis of the CCRF-CEM cancer cell line, evidenced by DNA fragmentation assay and DAPI staining.

• Journal of the Korean Society for information Management
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• v.5 no.1
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• pp.31-52
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• 1988

The information policy in Japan have bccir growing rapldlr 111 recent vttars. \'arioi~s level of govc~riimerital organrzatlons, ir~bt~tution arid agrircics have undt~rtak~~rr iriforrnatiori polrcy 111 order to i r l - crease information flow toward tlie society in Japan. At tlie same trme, computerized library systems also h a w uridergoirc rapid expansion. NACSIS(National Ceriter for- Science Informat~on System) wl~icl~ was cstablisl~ed bv Mirristr> of Etlr~c~arion, Sc~ence arid Culture haw witnessed dramatic adv;rnces i r i promoting for corrstructiori of database so as to provide their 11rf'3r.mat1orr nu nationwide scale. T l r i h articlr inrroduccs tlie actr\rtle> and ~mplcmeritat~o~~ of it format in^^ pol~cy wl~i(~li taktas a place hy goverrirnrlit of Japar~ aid arraly~c,.; thi~ ~ I . O I . P S I of deciiioii maltiiig iri polit~cal procedures. So far as b:ast-A\~ari riatioris art, ~ . n r i v t ~ r ~ ~ , e.;pc,ciall\. Kr,rc.an a~rd Japair !rave ,imilar cultural and liistorical backjir. ourii1, ard could t)t. tliif most a p p r o p r i a t ~ ~ caac stlldh for political ~nq~lerncritat~orr. Thus the topic of this artrclc will be useful to r t ~ a l l ~ t . Ore, trail ur~d c r r o r prorex, iri iiiior.matior~ pnlic\ulcorner.

• Journal of the Korean Magnetics Society
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• v.1 no.2
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• pp.31-36
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• 1991

Structural and compositional heterogeneities of sputter deposited, amorphous $Co_{87}Zr_{4}NB_{9}$ thin films were investigated using TEM and EDS with windowless detector. The films deposited with substrate bias and annealed in rotating magnetc field showed two amorphous phases of Co-rich region and (ZrNb)oxide-rich region, and revealed 'ultra-soft' magnetic properties. Revesible bias-responses and overdamped frequency responses, along with small Hc, Hk and Mr/Ms ratio, give the possibility of ultra-soft magnetic behavior fo CoZrNb thin films. We proposed the vortex type magnetization distribution in remanent state which was correlated with the thin film heterogeneity. Then, the ultra-soft characteristics of the compositionally heterogeneous films were explained by the spin vortices that minimized the total magnetostatic and exchange coupling energies.

• Korean Journal of Agricultural Science
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• v.3 no.2
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• pp.244-250
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• 1976

Candida brumptii was one of the best isolates which could grow on alcohol distillation slops (reported in the previous paper). Attempts were made to investigate the cultural conditions for cell mass production by this strain, and the results obtained were as follow. The supernatant of the alcohol distillation slops without dilution support ed better growth of the strain than diluted ones. The addition of ammonium sulfate (0.2%), ammonium phosphate (0.1-0.2%), potassium phosphate (0.2%) to the supernatant resulted in positive effects for the growth, among the various inorganic nitrogen and other salts supplements. BOD and COD of the supernatant were reduced approximately 30% and 20%, respectively in 3 days culture. Cell production was maximized when grown at $35^{\circ}C$ and pH 5.0. The yield of cell mass was 1.03% by dry weight and its crude protein content was about 52.65%

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.2
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• pp.87-90
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• 2008

Co-Pt alloy thin films were galvanostatically electrodeposited on Ru (30 nm)/Ta (5 nm)/Si (100) substrates from a amino-citrate based electrolyte. We used Ru(0002)-oriented buffer layers to control the crystallinity and orientation of the Co-Pt alloy thin films. The effect of solution temperature on the microstructure and magnetic properties of the Co-Pt alloy thin film was investigated. The samples were characterized by EDS, FESEM, XRD diffractometer using Cu $K{\alpha}$ radiation. The magnetic properties of these films were analyzed by a VSM and torque magnetometer. The Co-Pt alloy thin films were exhibited very high out-of-plane coercivity and squareness of the multilayer were 6527 Oe and 0.93, respectively, without heat treatment.

• Analytical Science and Technology
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• v.8 no.2
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• pp.195-203
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• 1995

Carbon and small amounts of alloying elements were added in Fe-5.7% Al ferromagnetic damping alloy. The specific damping capacities(SDC) of these alloys were investigated in relation to the grain size and the magnetic hysteresis loops. The behavior of carbon was analysed by XRD and EDS. These alloys showed characteristic damping nature of ferromagnetic damping materials. The alloying elements decreased SDC and especially the carbon was remarkable. The SDC was observed to be not related with the grain size but with the magnetic hysteresis loop area. The remarkable decrease of SDC by carbon addition was attributed to the locking migration of $90^{\circ}$ magnetic domain wall by the interstitial carbon in Fe-Al solid solution. However, the carbides also seems to decrease the SDC.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.346-346
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• 2011

실리콘 나노와이어는 높은 표면적으로 인해 뛰어난 감지 능력을 가지는 재료 중 하나로 다양한 센서 응용 분야에 사용되고 있다. 이를 제작하는 방법에는 Micro Electro Mechanical Systems (MEMS) 공정을 이용한 Top-down 방식과 Vapor-Liquid-Solid (VLS) 공정을 이용한 Bottom-up 방식이 널리 사용되고 있다. 특히 Plasma-Enhanced Chemical Vapor Deposition(PECVD)와 Au 촉매를 이용한 Bottom-up 방식은 수십 나노미터 이하의 실리콘 나노와이어를 간단한 변수 조절을 통해 성장시킬 수 있다. 또한 Au/Si의 공융점인 363$^{\circ}C$보다 낮은 온도에서 $SiH_4$를 분해시킬 수 있어 열적 효과로 인한 손실을 줄일 수 있는 장점을 지니고 있다. 하지만 PECVD를 이용한 실리콘 나노와이어 성장은 VLS 공정을 통해 표면으로부터 수직으로 성장하게 되는데 이는 센서 응용을 위한 전극 사이의 수평 연결 어려움을 지니고 있다. 따라서 이를 피하기 위한 표면 성장된 실리콘 나노와이어가 요구된다. 본 연구에서는 PECVD VLS 공정을 이용하여 $HAuCl_4$를 촉매로 이용한 표면 성장된 Tree-like 실리콘 나노와이어를 성장시켰다. 공정가스로는 $SiH_4$와 이를 분해시키기 위해 Ar 플라즈마를 사용 하였고 웨이퍼 표면에 HAuCl4를 분사하고 고진공 상태에서 챔버 기판을 370$^{\circ}C$까지 가열한 후 플라즈마 파워(W) 및 공정 압력(mTorr)을 변수로 두어 실험을 진행하였다. 기존의 보고된 연구와 달리 환원된 금 입자 대신 $HAuCl_4$용액을 그대로 사용하였는데 이는 표면 조도(Surface roughness)를 가지는 Au 박막 상태로 존재하게 된다. 이 중 마루(Asperite) 부분에 PECVD로부터 발생된 실리콘 나노 입자가 상대적으로 높은 확률로 흡착하게 되어 실리콘 나노와이어의 표면성장을 유도하게 된다. 성장된 실리콘 나노와이어는 SEM과 EDS를 이용하여 직경, 길이 및 화학적 성분을 측정하였다. 직경은 약 100 nm, 길이는 약 10 ${\mu}m$ 정도로 나타났으며 Tree-like 실리콘 나노와이어가 성장되었다. 향후 전극이 형성된 기판위에 이를 직접 성장시킴으로써 이 물질의 I-V 특성을 파악 할 것이며 이는 센서 응용 분야에 도움이 될 것으로 기대된다.

• YAKHAK HOEJI
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• v.51 no.1
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• pp.56-62
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• 2007

Twelve epoxy and hydroxydiosgenin derivatives (DI-1${\sim}$DI-12) were synthesized from diosgenin (25(R)-5-spirosten-3${\beta}$-ol). Diosgenin was epoxidized with m-chloroperoxybenzoic acid (mCPBA) to oxidize 25(R)-4${\alpha}$,5${\alpha}$-epoxyspirostane (DI-1). Diosgenin was reacted with DDQ to form 25(R)-1,4,6-spirostatrien-3-one (DI-2), which was treated with 30% H$_2$O$_2$ to give 25(R)-1${\alpha}$,2${\alpha}$-epoxy-4,6-spirostadien-3-one (DI-3) and treated with mCPBA to form 25(R)-6${\alpha}$,7${\alpha}$-epoxy-1,4-spirostadien-3-one (DI-7), respectively. DI-3 was reduced with NaBH$_4$ to afford 25(R) -1${\alpha}$,2 ${\alpha}$-epoxy-4,6-spirostadien-3${\beta}$-ol(DI-4) and reacted with Li metal in absolute ethanol to form 25(R)-2-ethoxy-1,4,6-spirostatrien-3-one (DI-5). DI-7 was reduced with NaBH$_4$ to produce 25(R)-3${\beta}$,7${\alpha}$-dihydroxy-4-spirostene (DI-8) and treated with Li metal in liquid ammonia to produce 25(R)-7${\alpha}$-hydroxy-4-spirosten-3-one (DI-9). DI-2 was reduced with NaBH$_4$ to form 25(R) -4,6-spirestadien-3${\beta}$-ol(DI-10), which was stirred with 30% H$_2$O$_2$ to synthesize 25(R)-4,6-spirostadien-3-one (DI-11) and reacted with mCPBA to give 25(R)-4${\beta}$,5${\beta}$ -epoxy-6-spirosten-3${\beta}$-ol (DI-12), respectively. The antinociceptive effects of synthesiz ed compounds were measured by hot plate method and compound DI-7 signifcantly exhibited antinociceptive effect. DI-2 decreased the serum triglyceride and total cholesterol levels in poloxamer P-407 injected rat.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.5
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• pp.243-248
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• 2010

Si-substituted biphasic calcium phosphates (Si-BCP) were prepared by co-precipitation method. X-ray diffraction and fourier transform infrared spectroscopy were used to characterize the structure of Si-BCP powders. The Si-BCP powders with various Ca/(P+Si) molar ratio were carried out on structural change of hydroxyapatite (HAp) and ${\beta}$-tricalcium phosphate ($\ss$-TCP). The in-vitro bioactivity of the Si-BCP powders was determined by immersing the powders in SBF solution, after that observing the chemical composition and morphology change by X-ray diffraction, scanning electron microscope and energy dispersive spectroscopy.