• Title/Summary/Keyword: $\alpha$-${Si_3}{N_4

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Isolation and Identification of Triterpenoids from the Mulberry (Morus alba) Root Bark (상백피(Morus alba root bark)로부터 triterpenoid의 분리 및 동정)

  • Jung, Jae-Woo;Park, Ji-Hae;Jung, Ye-Jin;Lee, Chang-Ho;Han, Daeseok;Baek, Nam-In
    • Journal of Applied Biological Chemistry
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    • v.57 no.4
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    • pp.295-299
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    • 2014
  • The mulberry (Morus alba L.) root barks were extracted with 80% aqueous methanol at room temperature. The concentrated extract was partitioned as ethyl acetate (EtOAc), n-BuOH, and $H_2O$ fractions. From the EtOAc fraction, five triterpenoids were isolated through the repeated silica gel and octadecyl $SiO_2$ column chromatographies. According to the results of physico-chemical and spectroscopic data including nuclear magnetic resonance, mass spectrometry, and infrared, the chemical structures of the triterpenoids were respectively determined as ${\alpha}$-amyrin (1), ${\alpha}$-acetyl amyrin (2), lupeol (3), betulinic acid (4), and glutinol (5). Compounds 1, 3, and 5 were isolated for the first time from the mulberry root bark.

Development of Mathematical Model for the Hydrolysis Fish Oil (물고기 기름의 가수분해에 대한 수학적 모형개발)

  • Kim Won-Ho;Lee Yong-Hoon;Park Ji-Suk;Hur Byung-Ki
    • KSBB Journal
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    • v.20 no.2 s.91
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    • pp.106-111
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    • 2005
  • The functional relationship between the number of mole of an i-fatty acid (Si) included in fish oil and the hydrolysis time(t) was expressed as a mathematical model, $S_i=-{\alpha_i}1n(t)+\beta_i$. The average errors of calculated values on the basis of the measured values were distributed in the range of less than $5\%$ for all the 15 fatty aids composing of fish oil. The equation of hydrolysis rate of each fatty acid was deduced as $v_i={\gamma_i}exp(\frac{S_i}{\alpha_i})$ from the above-mentioned $S_i=-{\alpha_i}ln(t)+{\beta_i}$. Therefore the hydrolysis yields of fatty acids were analyzed using the equation of $S_i\;Vs.\;t.$. The 15 fatty acids were categorized into 4groups from the view point of hydrolysis yield. The hydrolysis yields of the first group, including C14:0, C16:0, C16:1, C18:0, C18:1 (n-7) and 1l8:1 (n-9), were higher than $70\%$ at 48 hr of hydrolysis. Those of the second group, C20:1, C22:1, C18:3, C20:4 and C20:5, were distributed from $40\%,\;to\;60\%$, and third group were around $30\%$. The final group containing only C22:6 was very hard to be hydrolyzed and the yield was less than $20\%$ at the same time.

Optical, Mechanical and Tribological Properties of $Y_2O_3$ $Er_2O_3$ and $Nd_2O_3$ Doped Polycrystalline Silicon Nitride Ceramics

  • Joshi, Bhupendra;Lee, Su-Wan
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2010.05a
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    • pp.51.1-51.1
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    • 2010
  • $Y_2O_3$ $Er_2O_3$ and $Nd_2O_3$ doped polycrystalline silicon nitride were prepared by hot pressed sintering at $1850^{\circ}C$ and their optical transmittance were investigated in visible and in infrared region. Mechanical and tribological properties were also investigated. Grain growth in silicon nitride was reduced with addition of $Y_2O_3$ and $Nd_2O_3$. 1 wt.% of each rare earth metal were sintered with 3 wt.% MgO, 9wt.% AlN and 87 wt.% of ${\alpha}-Si_3N_4$. Adding these rare earth metal oxides shows good mechanical properties as high strength and toughness and also shows low friction coefficient.

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Low-temperature synthesis of nc-Si/a-SiNx: H quantum dot thin films using RF/UHF high density PECVD plasmas

  • Yin, Yongyi;Sahu, B.B.;Lee, J.S.;Kim, H.R.;Han, Jeon G.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.341-341
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    • 2016
  • The discovery of light emission in nanostructured silicon has opened up new avenues of research in nano-silicon based devices. One such pathway is the application of silicon quantum dots in advanced photovoltaic and light emitting devices. Recently, there is increasing interest on the silicon quantum dots (c-Si QDs) films embedded in amorphous hydrogenated silicon-nitride dielectric matrix (a-SiNx: H), which are familiar as c-Si/a-SiNx:H QDs thin films. However, due to the limitation of the requirement of a very high deposition temperature along with post annealing and a low growth rate, extensive research are being undertaken to elevate these issues, for the point of view of applications, using plasma assisted deposition methods by using different plasma concepts. This work addresses about rapid growth and single step development of c-Si/a-SiNx:H QDs thin films deposited by RF (13.56 MHz) and ultra-high frequency (UHF ~ 320 MHz) low-pressure plasma processing of a mixture of silane (SiH4) and ammonia (NH3) gases diluted in hydrogen (H2) at a low growth temperature ($230^{\circ}C$). In the films the c-Si QDs of varying size, with an overall crystallinity of 60-80 %, are embedded in an a-SiNx: H matrix. The important result includes the formation of the tunable QD size of ~ 5-20 nm, having a thermodynamically favorable <220> crystallographic orientation, along with distinct signatures of the growth of ${\alpha}$-Si3N4 and ${\beta}$-Si3N4 components. Also, the roles of different plasma characteristics on the film properties are investigated using various plasma diagnostics and film analysis tools.

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Crystalline Properties of Carbon Nitride films According to Substrates and Growth Conditions (기판과 성장조건에 따른 질화탄소막의 결정성장 특성)

  • 이지공;이성필
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.12
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    • pp.1103-1109
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    • 2003
  • Crystalline carbon nitride films have been deposited by RF reactive magnetron sputtering system with negative DC bias. The carbon nitride films deposited on various substrates showed ${\alpha}$- C$_3$N$_4$,${\beta}$-C$_3$N$_4$ and lonsdaleite structures through XRD and FTIR We can find the grain growth of hexagonal structure from SEMI photographs, which is coincident with the theoretical carbon nitride unit cell. When nitrogen gas ratio is 70 % and RF power is 200 W, the growth rate of carbon nitride film on quartz substrate is about 2.1 $\mu\textrm{m}$/hr.

Type 3 muscarinic acetylcholine receptor stimulation is a determinant of endothelial barrier function and adherens junctions integrity: role of protein-tyrosine phosphatase 1B

  • Jiao, Zhou-Yang;Wu, Jing;Liu, Chao;Wen, Bing;Zhao, Wen-Zeng;Du, Xin-Ling
    • BMB Reports
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    • v.47 no.10
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    • pp.552-557
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    • 2014
  • The main purpose of this study was to investigate whether type 3 muscarinic acetylcholine receptor (M3R) dysfunction induced vascular hyperpermeability. Transwell system analysis showed that M3R inhibition by selective antagonist 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP) and small interfering RNA both increased endothelial permeability. Using coimmunoprecipitation and Western blot assay, we found that M3R inhibition increased VE-cadherin and ${\beta}$-catenin tyrosine phosphorylation without affecting their expression. Using PTP1B siRNA, we found that PTP1B was required for maintaining VE-cadherin and ${\beta}$-catenin protein dephosphorylation. In addition, 4-DAMP suppressed PTP1B activity by reducing cyclic adenosine monophosphate (cAMP), but not protein kinase $C{\alpha}$ ($PKC{\alpha}$). These data indicate that M3R preserves the endothelial barrier function through a mechanism potentially maintaining PTP1B activity, keeping the adherens junction proteins (AJPs) dephosphorylation.

Electrical Properties of MIM and MIS Structure using Carbon Nitride Films

  • Lee, Hyo-Ung;Lee, Sung-Pil
    • Transactions on Electrical and Electronic Materials
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    • v.7 no.5
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    • pp.257-261
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    • 2006
  • Nano-structured carbon nitride $(CN_x)$ films were prepared by reactive RF magnetron sputtering with a DC bias at various deposition conditions, and the physical and electrical properties were investigated. FTIR spectrum indicated an ${alpha}C_3N_4$ peak in the films. The carbon nitride film deposited on Si substrate had a nano-structured surface morphology. The grain size was about 20 nm and the deposition rate was $1.7{\mu}m/hr$. When the $N_2/Ar$ ratio was 3/7, the level of nitrogen incorporation was 34.3 at%. The film had a low dielectric constant. The metal-insulator-semiconductor (MIS) capacitors that the carbon nitride was deposited as insulators, exhibited a typical C-V characteristics.

UHV Materials (초고진공계재료)

  • 박동수
    • Proceedings of the Korean Vacuum Society Conference
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    • 1998.02a
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    • pp.24-24
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    • 1998
  • 반도체장비를 포함하는 초고진공장비의 園훌化가 급속히 그리고 절실히 요구되고 있는 것이 현실정이다. 當面해서 실현할 국산진공장비의 대상은 廣範圍하다. 즉, 각종 진공 pump ( (rotary, dry, diffusion, cryo, ion, turbo melecular pump), 진공 chamber, 진공 line, gate valve 를 위 시 한 진공 V머ve, flange, gasket, fl않d야lU, mainpulater 퉁 진공 部品이 다. 진공계 의 핵심 은 適切하고 優良한 진공재료의 선태파 사용이다. 진공장비는 사용자가 원하는 진공도를 원하 는 시간 동안 륨空度를 유지해 주어야 한다. 진공재료 선태의 기준사항은:(1) 기체의 透過성 (2) 薰했훌 (3) 혔體放出특성 - -outgassing과 degassing- (4) 機械的 량훌度 (5) 온도 의존성 (6) 化學톡성 (7) 加I성 및 鎔接 성 (8) 課電특성 (9) 磁氣특성 (10) 高速함子 및 放射線 특성 (11) 經濟성 및 調達생 둥이 다. 우량한 초고진공계재료는 풍부하게 개발되어 왔고, 또 新材料들이 개발되고 있다. 여기에서는 주로 초고진공 내지는 극고진공계의 構造材料, 機能材料, 部品材料 일반파 몇가지 신재료의 특 성에 관해서 記述한다. M Mild SteeHSAE, 1112, 1010, 1020, 1022, etc)., S Stainless SteeHAlSI, 304, 304L, 310, 316, 321, 347): 구조재료, chamber, fl하1ges A Aluminum과 Alloys (1060, 1100, 2014, 4032, 6(뻐1): 구조재료, chamber, flanges, gaskets A AI, Al 떠loy는 SS에 代替하는 역 할올 시 작하고 있다. C Copper, Copper Alloys(C11$\alpha$)0, C26800, C61400, Cl7200): 내장인자, gasket, cryopanel, tubing T Titanium, Ziriconium, Haf띠um 및 Alloys: 특히 Ti은 10n pump 용 getter material 이 외 에 U UHV,XHV용 chamber계로서 관심올 끌고 있다. N Nickel, Nickel Alloys (200, 204, 211, monel, nichrome): 부식 방지 , 전자장치 , 자기 장치 귀 금속(Ag, Au, Pt, Pd, Rh, Ir, Os, Ru): 보조부품, gasket, filament, coating, thermocouple, 접 합부위 T TiC, SiC, zrC, HfC, TaC 둥의 탄화물과, BN, TiN, AlN 동의 질화물, 붕화물이 둥장하고 었 다. 유리: Soda Lime, Borosilicate, Potash Soda Lead: View Port, Chamber envelope C Ceramics: AlZ03, BeO, MgO, zrOz, SiOz, MgOzSiOz, 3Alz032SiOz, Z$textsc{k}$hSiOz S상N4: e electrical, thermal insulators, crucibles, boats, single crystals, sepctr려 windows 저자는 최근 저자들이 발견한 Zr-Ti-Cu-Ni-Be amorphous alloys coated cham뾰r가 radiation p proof로 이용될 수 있는 사실을 점검하고 었다 .. Z.Y. Hua 들은 Cs3Sb를 새로운 photocathode 재료로 보고하고 있다.

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Automatic Notification System for Nuclear Medicine Blood Test (핵의학 혈액 검사의 경고치 자동통보 시스템)

  • Sim, Seong-Jae;Yoon, Pil-Young;Lim, Soo-Yeon;Cheon, Jun-Hong;Shin, Young-Kyoon;Yu, Seon-Hui;Cho, Si-Man
    • The Korean Journal of Nuclear Medicine Technology
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    • v.13 no.3
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    • pp.159-164
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    • 2009
  • Purpose: The automatic notification system for alarm values on blood tests conducted by this hospital is designed to immediately inform the attending physician of the result of a blood test, to help the relevant patient to promptly receive proper treatment, and furthermore, to reduce the likelihood of a fatal influence to the patient. From 2004, the clinical pathology department of this hospital has been operating an automatic notification system for blood tests, in relation to the items of WBC, Hb, Plt, PB cell morphology, Malaria, PT, aPTT, BT, fibrinogen, Ca, K, Na, Cl, Mg, Glucose, Ketone, Digoxin, PKU, Homocystinuria, 17-OHP, Neonatal TSH, and Galactosemia. Recently, the blood test room of the nuclear medicine department has been operating an automatic notification system for the alarm values of a blood test, in relation to three items of TSH, FT4, and 17-${\alpha}$-OH-PGR, and the details of its operation will be described here. Materials and Methods: The subjects were newborn babies that were receiving TSH, FT4, and $17{\alpha}$-OH-PGR prescriptions from February $19^{th}$ to May $11^{st}$, 2009, and who met with the following criteria: N2340 Thyroid-Stimulating Hormone: >$10{\mu}IU/mL$ (Reference value: 0.4~5.0). N2360 Free-Thyroxine: <$0.8{\mu}g/dL$ (Reference value: 0.8~1.9), N2444 $17{\alpha}$-OH-Progesterone: >$30\;{\mu}g/mL$ (Reference value: Male (0.6~3.42), Female follicular phase (0.19~1.8). The automatic notification system was operated by entering test items, relevant treatment departments, and standard values for reporting alarm values into the OCS program, and then transmitting results that met with the input conditions to the PDAs of the prescription and the attending physician by SMS. Results: Reporting an alarm value of the nuclear medicine blood test, which can have a fatal influence on the lives of patients, will help cure patients, improve the quality of the test, and furthermore, will increase the patient's satisfaction with the prescription and treatment of the test.

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The search and development for antitumor compounds from the marine algae (해조류 유래의 항종양성 물질의 탐색과 개발)

  • 손병화
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1994.04a
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    • pp.211-211
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    • 1994
  • 항종양성 화합물의 개발을 지향한 해양생물 유래의 생물활성 물질의 화학적 연구의 일환으로써 다양한 종류의 생물활성 (즉, 항균작용, 혈중콜레스테롤 저하작용)등을 나타내며, 구입수가 용이한 홍조 꼬시래기 (Gracilaria verrucosa) 및 갈조 지충이 (Sargassum thunbergii)의 아세톤 및 메탄올 엑스를 EtOAc 및 n-BuOH로 분획한후 각 분획을 SiO$_2$ column, TSK gel(Toyo pearl HW-40F), $\mu$-Bondapak column 및 HPLC등으로 분리 정제하여, 새로운 glyceroglycolipid(GV-5, -6, ST-6) 및 glycerylglycoside(GV-12)를 얻었다. 이렇게 분리된 화합물의 물리화학적 성질, 화학반응 및 분광학적 data를 종합 검토한 결과 GV-5, -6, -12, 및 ST-6은 각각 1,2-diacyl-3-0-($\alpha$-D-galactopyranosyl) glycerol (acyl : palmitate-oleate-arachidonate 4: 1 : 9) (1), 1,2-diacyl -3-0-〔$\alpha$-D-galactopyranosyl -(1 "$\longrightarrow$6')-0-$\beta$-D-galactopyranosyl〕 glycerol (acyl : palmitate-oleate-arachidonate(5:1:4)(3), 2-0-($\alpha$-D-galactopyranosyl) glycerol (5), 및 sodium salt of 1-acyl-3-0-(6'-sulfo-$\alpha$-D-quinovopyranosyl) glycerol(acyl:palmitate-oleate 96:4)(8) 이라는 것이 판명되었다. 그리고 GV-5 및 -6은 마우스 백혈병세포 (L1210)에 대한 세포독성 ($IC_{50}$/ of GV-5, and -6:8.0$\mu\textrm{g}$/ml and 10.8$\mu\textrm{g}$/ml )외에, 사람의 상피암세포에 대한 성장억제효과 [growth inhibitor(%) in 20$\mu\textrm{g}$/m1 :GV-5(39.9%), GV-6(16.7%)를 나타내었으며, 한편, GV-5, GV-6, -12 및 ST-6은 각각 쥐의 F9 기형암종 세포의 분화유도 활성을 나타내어 항종양제로의 개발에 많은 흥미가 기대된다.기대된다.

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