• 제목/요약/키워드: Mass varying

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팔미틴산덱사메타손이 봉입된 지질나노입자의 제조: 지질종류와 함량에 따른 물리적 특성 (Preparation of Dexamethasone-21-palmitate Incorporated Lipid Nanosphere: Physical Properties by Varying Components and Ratio of Lipid)

  • 정석현;이정은;성하수;신병철
    • Journal of Pharmaceutical Investigation
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    • 제36권6호
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    • pp.355-361
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    • 2006
  • Intraarticular corticosteroid injections for therapy of rheumatic arthritis are administered with the aim of optimal local anti-inflammatory effect at the injection site. Since the side effects of corticosteroidal drug, dexamethasone(DEX), administered at hish dose limited the therapeutic efficacy, there was a need to design a new drug delivery system for controlled release of dexamethasone. As a prodrug for continuous therapeutic efficacy, dexamethasone-21-palmitate(DEX-PAL) was prepared via esterification of palmitoyl chloride and dexamethasone. DEX-PAL was identified by NMR and MASS analysis. DEX-PAL or DEX was entrapped in lipid nanosphere which could be prepared by using a self emulsification-solvent evaporation method. Physicochemical characteristics such as mean particle diameter, zeta potential and drug loading efficiency of the lipid nanospheres were investigated with variation of either the kind of lipid or the lipid composition. The lipid nanospheres had a mean diameter $83{\sim}95$ nm and DEX-PAL loading efficiency of up to 95%. The drug loading efficiency increased with the increase of aliphatic chain length attached to the phospholipid. The incorporation of cationic lipid was very efficient for both reducing particle size of lipid nanospheres and enhancing drug loading efficiency. The lipid nanospheres containing DEX-PAL may be a promising novel drug carrier for the controlled release of the poorly water-soluble drugs.

Testosterone이 암컷 쥐의 체구성분 및 근육단백질 합성율에 미치는 영향 (Effects of Testosterone on Body Composition and Muscle Protein Synthesis in Female Rats)

  • Choo Jong Jae
    • Journal of Nutrition and Health
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    • 제25권6호
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    • pp.485-491
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    • 1992
  • 남성호르몬인 testosterone 투여가 정상 암컷쥐의 체중, 체구성성분(체단백질, 체지방), 에너지 대사 및 근육단백질 대사에 미치는 영향을 조사하였다. Testosterone propionate를 체중 1kg당 1mg(1mg/kg)으로 10일간 투여했을 때 식이섭취량은 변화하지 않았음에도 체중 및 체단백질, 체지방은 유의적으로 증가하였다. 반면 testosterone propionate를 4번 또는 10mg/kg으로 투여 시에는 체단백질만 유의적으로 증가하였고 체지방은 영향을 받지 않았다. Testosterone propionate에 의한 체내 에너지축적(energy gain) 및 에너지 이용율(gross energetic effciency) 증가는 1mg/kg의 투여량에서만 관찰되었다. 근육조직(gastrocnemius muscle)의 무게, 단백질 및 RNA함량은 모든 투여량에서 유의적으로 증가하였으나 단백질 합성율은 어느 투여량에서도 영향을 받지 않았다. 이러한 결과를 통해 testosterone이 체중 및 체단백질, 체지방에 미치는 영향은 투여량에 크게 의존하며 testosterone의 근육단백질 증진 효과는 단백질 합성율에는 영향을 미치지 않고 단백질 분해율을 저하시킴으로써 발휘된다는 것을 알 수 있다.

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Streptomyces hygroscopicus MJM1004가 생산하는 항진균성 항생 물질의 분리 및 구조 결정 (Isolation and Structural Determination of Antifungal Antibiotic from Streptomyces hygroscopicus MJM1004)

  • 배주윤;권형진;서주원
    • Applied Biological Chemistry
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    • 제42권4호
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    • pp.271-276
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    • 1999
  • 새로운 천연물 농약 또는 생산군주를 개발하기 위하여 Streptomyces 속의 여러 균주를 대상으로 항진균 물질을 탐색하여 항진균 물질 생산 균주 Streptomyces hygroscopicus MJM1004를 선발하였다. 항진균 물질의 생산을 위한 발효 배지를 선정하기 위하여 여러 탄소원, 질소원과 무기원을 대상으로 균체 생장 정도와 항진균 물질의 생산성을 조사하였으며, 생산 배지는 2% soybean meal, 1% glucose, 2% starch, 0.3% $CaCO_3$, 0.05% $MgSO_4{\cdot}7H_2O$, 0.05% $K_2HPO_4$를 조성으로 하였다. S. hygroscopicus MJM1004 균주의 균체에서 추출된 항진균 물질은 Candida albicans와 여러 식물 병원성 곰팡이들에 대하여 광범위한 저해 효과를 나타내었다. S. hygroscopicus MJM1004 균체로부터 분리된 항진균 물질, SH-1004를 핵자기공명법($^1H,\;^{13}C$, DQF COSY, HMQC 및 HMBC)을 통하여 분석한 결과 azalomycin F complex 임을 확인할 수 있었다. Positive FAB mass spectrum을 통하여 SH-1004는 azalomycin F4a와 F5a가 1.8 : 1의 비율로 혼합된 물질임을 확인하였다.

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활성탄전극을 이용한 분진제거에서 전극의 적정 간격에 관한 연구 (Optimal Distance between Positive and Negative Electrode-Plates Coated with Activated Carbon in Dust Removal Chamber)

  • 김광수;박현철;전태환;이주행;남상철
    • 대한환경공학회지
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    • 제35권11호
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    • pp.821-826
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    • 2013
  • 본 연구의 목적은 분진제거 장치에서 전극간의 적정간격을 알아보기 위한 것이다. 실험은 전극간격을 3 cm, 2 cm, 1 cm로 직렬로 놓고 유입유량을 변화시켜 수행하였다. 실험결과로부터 분진제거를 위한 적정 선속도는 6 cm/sec였고 전극표면에 부착되는 분진 총량은 전극의 간격이 가까울수록 증가하였다. 그러나 1 cm 정도로 매우 가까울 경우는 전극판에 부착된 분진은 탈착되었으며 이는 분착된 분진의 역이온화 즉 전하의 변화 때문인 것으로 사료되었다. 결과적으로 전극판에서 양전극과 음전극 간의 간격은 2 cm가 적당하고 이때의 분진부하율은 $24mg/min{\cdot}m^2$였다.

조피볼락(Sebastes schlegelii) Interferon Regulatory Factor 8 (IRF8)의 분자유전학적 특성 및 발현 분석 (Molecular Characterization and Expression Analysis of Interferon Regulatory Factor 8 (IRF8) in the Black Rockfish Sebastes schlegelii)

  • 양혜림;권혁재;이성도;;김명진;이제희
    • 한국수산과학회지
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    • 제50권3호
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    • pp.302-310
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    • 2017
  • Interferon regulatory factor 8 (IRF8) is essential for the development of B and T cells, as well as for the activity of dendritic cells and macrophages. We performed molecular characterization of IRF8 from rock fish, Sebastes schlegelii (Ss), and investigated the spatial and temporal profile of mRNA expression after challenge with lipopolysaccharide (LPS), polyinosinic:polycytidylic acid (poly I:C), or Streptococcus iniae. The full-length cDNA sequence of SsIRF8 was 1,657 bp, containing an ORF of 1,266 bp. The gene had a predicted molecular mass of 47.7 kDa and an isoelectric point of 5.99. The amino acid sequence coded by this gene showed the highest degree of identity (90.8%) and similarity (96.2%) with IRF8 from Oplegnathus fasciatus. The SsIRF8 mRNA was expressed ubiquitously, at varying levels, with the highest level of expression observed in the spleen. To confirm the role of SsIRF8 in mediating the immune response, we measured SsIRF8 mRNA expression in the splenic tissue at different time points after injection with LPS, poly I:C, or S. iniae. The qRT-PCR results showed that SsIRF8 mRNA expression in the poly I:C-injected group was highly upregulated 6 hr after exposure (P<0.05). Expression of SsIRF8 mRNA in the S. iniae-injected group peaked at 24 hr. These results suggest that SsIRF8 might be important in regulating the strength of the rockfish immune response to immunostimulatory agents.

동북아시아 대기오염물질의 이동 패턴에 따른 장거리 수송 특성 연구 (Characteristics of Long-Range Transport of Air Pollutants due to Different Transport Patterns over Northeast Asia)

  • 박신영;김연종;김철희
    • 한국대기환경학회지
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    • 제28권2호
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    • pp.142-158
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    • 2012
  • This paper investigates the physical and chemical characteristics of long-range transport (LRT) process of air pollutants by employing the MM5-CMAQ and its comparison with local emission dominant (LED) case over northeast Asia. We first classified high air pollution days into LRT and LED cases based on the synoptic meteorological variables of vorticity and geostrophic wind speed/direction at a geopotential level of over 850hPa. LRT cases are further categorized into three types of transport patterns (LRT-I-III) according to the air mass pathways from source regions. LRT-I-III are originated from northern, central, and southern China, respectively, identified by back trajectory analysis. Three LRT-I-III groups have different and unique locations of high pressure and transport pathways. The chemical characteristics showed that the simulated spatial distributions varied in terms of locations of maximum concentrations and the temporal variation of surface concentrations. The primary air pollutants such as $NO_x$, $PM_{10}$ and $SO_2$ of all of three LRT cases are well transported into Korea peninsula with different concentration levels. Of LRT cases, LRT-II has the greatest effect on air quality of Korea peninsula, followed by LRT-I and LRT-III. In comparison with LRT, the LED case shows relatively higher air pollution concentrations in general, but showed a variety of different air quality levels following the emission strength pattern. These widely varying patterns are impling the case dependent multi-directional approach for the development of indicators of long-range transport process over northeast Asia.

사각 빙해수조에서의 Pack Ice 모형시험 기법 개발 (Development of Model Test Methodology of Pack Ice in Square Type Ice Tank)

  • 조성락;유창수;정성엽
    • 대한조선학회논문집
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    • 제48권5호
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    • pp.390-395
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    • 2011
  • The main purpose of ice model basin is to assess and evaluate the performance of the Arctic ships and offshore structures because the full-scale tests in ice covered sea are usually very expensive and difficult. There are various ice conditions, such as level ice, brash ice, pack ice and ice ridge, in the real sea. To estimate their capacities in ice tank accurately, an appropriate model ice sheet and prepared ice conditions copied from actual sea ice conditions are needed. Pack ice is a floating ice that has been driven together into a single mass and a mixture of ice fragments of varying size and age that are squeezed together and cover the sea surface with little or no open water. So Ice-class vessels and Icebreaker are usually operated in pack ice conditions for the long time of her voyage. The most ice model tests include the pack ice test with the change of pack ice concentration. In this paper, the effect of pack ice size and channel breadth in pack ice model test is conducted and analyzed. Also we presented some techniques for the calculation of pack ice concentration in the model test. Finally, we developed a new model test methodology of pack ice condition in square type ice tank.

Deflection of Ultra-high Energy Cosmic Rays by the Galactic Magnetic Field

  • Kim, Jihyun;Kim, Hang Bae;Ryu, Dongsu
    • 천문학회보
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    • 제39권2호
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    • pp.73.1-73.1
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    • 2014
  • We investigate the influence of the galactic magnetic field (GMF) on the arrival direction (AD) of ultra-high energy cosmic rays (UHECRs) by searching the correlation with the large-scale structure (LSS) of the universe. The deflection angle of UHECRs from sources by the GMF is reflected in a source model by introducing the Gaussian smearing angle as a free parameter. Assuming the deflections by the GMF are mainly dependent on the galactic latitude, b, we divide the regions of sky by b and analyze the correlation between the AD of UHECRs and the LSS of the universe in each region varying the smearing angle. We find the deflection is strongly dependent on the galactic latitude by the maximum likelihood estimation. Specifically, the best-fit smearing angles are $9^{\circ}$ and $84^{\circ}$ in the high galactic latitude (HGL), $-90^{\circ}$ < b < $-60^{\circ}$, and in the low galactic latitude (LGL), $-30^{\circ}$ < b < $30^{\circ}$, respectively. The strength of GMF becomes stronger from the HGL to the LGL. From the results, we can estimate the strength of GMF in each region. In the LGL, for example, if we assume UHECRs are protons, we have the order of $100{\mu}G$ GMF, which is much stronger than the expected value of conventional GMF model. However, if the primaries are heavy nuclei, which is consistent with the observational result of mass composition analysis, the order of GMF strength is a few ${\mu}G$. More data from the future experiments make it possible to study the GMF between the source of UHECRs and Earth more accurately.

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A MONTE CARLO STUDY OF FLUX RATIOS OF RAMAN SCATTERED O VI FEATURES AT 6825 Å AND 7082 Å IN SYMBIOTIC STARS

  • Lee, Young-Min;Chang, Seok-Jun;Heo, Jeong-Eun;Hong, Chae-Lin;Lee, Hee-won
    • 천문학회보
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    • 제41권2호
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    • pp.57.3-58
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    • 2016
  • A symbiotic star is a wide binary system consisting of a hot white dwarf and a mass losing giant, where the giant loses its material in the form of a slow stellar wind resulting in accretion onto the white dwarf through gravitational capture. Symbiotic stars are known to exhibit unique spectral features at 6825 and 7082, which are formed from O VI 1032 and 1038 through Raman scattering with atomic hydrogen. In this Monte Carlo study we investigate the flux ratio of 6825 and 7082 in a neutral region with a geometric shape of a slab, cylinder and sphere. By varying the amount of neutral hydrogen parametrized by the column density along a specified direction, we compute and compare the flux ratio of Raman scattered O VI 6825 and 7082. In the column density around 1020 cm-2, flux ratio changes in a complicated way, rapidly decreasing from the optically thin limit to unity the optically thick limit as the column density increases. It is also notable that when the neutral region is of a slab shape with the O VI source outside the slab, the optically thick limit is less than unity, implying a significant fraction of O VI photons escape through Rayleigh scattering near the boundary. We compare our high resolution CFHT data of HM Sge and AG Dra with the data simulated with finite cylinder models confirming that 'S' type symbiotic tend to be characterized by thicker HI region that 'D' type counterparts. It is expected that this study will be useful in interpretation of the clear disparity of Raman O VI 6825 and 7082 profiles, which will shed much light on the kinematics and the asymmetric distribution of O VI material around the hot white dwarf.

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유도결합 플라즈마에 의한(Ba, Sr)TiO$_3$ 박막의 식각 특성 연구 (The Study on the Etching Characteristics of (Ba, Sr)TiO$_3$ Film by Inductively Coupled Plasma)

  • 김승범;이영준;염근영;김창일
    • 전자공학회논문지D
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    • 제36D권4호
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    • pp.56-62
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    • 1999
  • 본 연구에서, (Ba,Sr)TiO\sub 3\ 박막이 rf 전력, dc 바이어스 전압 및 반응로 압력과 같은 식각 공정 변수를 변화하여 ICP에서 Cl\sub 2\Ar 가스 혼합비에 따라 식각되었다. 0.2의 Cl\sub 2\/(Cl\sub 2\+Ar) 가스 혼합비, 600 W의 rf 전력,250 V의 dc 바이어스 전압 및 5 mTorr의 반응로 압력의 공정 조건하에서 식각율은 56nm/min이었다. 이때 Pt, SiO\sub 2\ 막에 대한 BST 박막의 식각 선택비는 각각 0.52, 0.43이었다. 식각된 BST 박막의 표면반응은 XPS로 분석하였다. Ba는 BaCl\sub 2\ 와 같은 화학적인 반응과 물리적인 스퍼터링에 의해 제거되었다. Sr의 제거는 Sr과 Cl의 화확적인 반응보다 Ar 이온 충격이 더 효과적이었다. Ti는 TiCl\sub 4\ 와 같은 화학반응에 의해 용이하게 제거되었다. XPS 분석 결과를 비교하기 위하여 SIMS의 분석을 수행하여 비교한 결과 동일한 결론을 도출하였다.

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