• 제목/요약/키워드: $H_{\alpha}$

검색결과 5,029건 처리시간 0.033초

Outflow Kinematics manifested by the Hα line : Gas outflows in Type 2 AGNs

  • Kang, Daeun;Woo, Jong-Hak;Bae, Hyun-jin
    • 천문학회보
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    • 제42권2호
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    • pp.72.1-72.1
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    • 2017
  • Energetic ionized gas outflows driven by active galactic nuclei (AGN) have been studied as a key phenomenon related to AGN feedback. To probe the kinematics of the gas in the narrow line region, [O III] ${\lambda}5007$ has been utilized in a number of studies, showing non-virial kinematic properties due to AGN outflows. We statistically investigate whether the $H{\alpha}$ emission line is influenced by AGN driven outflows, by measuring the kinematic properties based on the $H{\alpha}$ line profile, and by comparing them with those of [O III]. Using the spatially integrated spectra of ~37,000 Type 2 AGNs at z < 0.3 selected from the SDSS DR7, we find a non-linear correlation between $H{\alpha}$ velocity dispersion and stellar velocity dispersion, which reveals the presence of the non-gravitational component, especially for AGNs with a wing component in $H{\alpha}$. The large $H{\alpha}$ velocity dispersion and velocity shift of luminous AGNs are clear evidence of AGN outflow impacts on $H{\alpha}$ emitting gas, while relatively smaller kinematic properties compared to those of [O III] imply that the observed outflow effect on the $H{\alpha}$ line is weaker than the case of [O III].

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Cyclodextrin의 사용과 pH의 변화를 이용한 Levofloxacin 생산 증대 연구

  • 문지숙;노윤숙;오선영;장성재;임상민;김동일
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2001년도 추계학술발표대회
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    • pp.662-665
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    • 2001
  • PLE를 이용한 levofloxacin의 생산에서 기질 150 mM 사용의 경우 두배의 몰농도 로 ${\alpha}-CD$를 사용하여 산물의 생산량을 3.7 배까지 증가시킬 수 있었다. 그러나 이 경우 ${\alpha}-CD$의 사용량이 많아 경제성이 떨어지는 단점이 있다. 이에 같은 몰농도로 ${\alpha}-CD$를 사용하고 pH에 변화를 주어 용해도를 향상시켜 보았다. 기질 100 mM의 경우 pH 5.6에서 같은 몰농도의 ${\alpha}-CD$를 사용한 경우 ${\alpha}-CD$를 사용하지 않은 것에 비해 4.4배의 수율의 증대가 있었다.

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자외선 조사에 의한 수용액 중에 함유되어 있는 엔도설판 alpha, beta, sulfate의 광분해 (Photodegradation of Endosulfan alpha, beta, and sulfate in Aqueous Solution by UV Irradiation Only)

  • 유건상;김미향;이화성;황현직
    • 한국환경과학회지
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    • 제15권11호
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    • pp.1061-1067
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    • 2006
  • Photodegradation of endosulfan alpha, beta, and sulfate known as the most toxic substance among organochlorine pesticides by UV irradiation was studied at experimental conditions such as different pH aqueous solution and reaction time. The initial concentration of endosulfan alpha, beta, and sulfate in aqueous solution was 500 ppb, respectively. The experiment of photodegradation was conducted in a quartz reactor equipped with a low pressure mercury lamp (100 W, 240 nm). The samples were withdrawn from the photo reactor at intervals of 0, 10 min, 30 min, 1 hr, 2 hr, and 4 hr. Endosulfan sulfate was never hydrolyzed and photodegraded in wide range of pH. At pH 5 and reaction time (240 min), endosulfan alpha was photodegraded up to 67%. Both endosulfan alpha and beta were started to photodegrade at pH 6.5 with the lapse of time, resulting in approximately 99.9% and 87.2% of photodegradation efficiency, respectively. Furthermore, at pH 9, endosulfan alpha and beta was partially hydrolyzed and photodegraded to 99.5% at 120 min of reaction time. During the photolysis, any photo-products of endosulfan alpha, beta, and sulfate were not observed.

$IO_4$-산화전분 변형에 의한 밀 $\beta$-Amylase의 안정성 증가 (Stabilization of Wheat $\beta$-Amylase by Modification with $IO_4$-Oxidized Starch)

  • 안용근
    • 한국식품영양학회지
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    • 제13권4호
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    • pp.348-352
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    • 2000
  • 과요오드산-산화전분으로 밀 $\beta$-amylase(Himaltosin GL. 일본한큐바이오사)를 변형시켜서 인공당단백질을 만들었다. pH 8.0에서 변형한 효소는 비변형효소의 96%. pH 9.7에서 변형한 효소는 17%의 활성이 남았다. 6$0^{\circ}C$에서의 열 안정성은 $\alpha$-cyclodextrin ( $\alpha$-CD) 존재 시에 변형하여 $\alpha$-CD 존재시에 분석한 효소는 10분 뒤에 비활성의 8%가 남은 반면 변형하지 않은 효소는 5% 밖에 남지 않았다. pH안정성은 변형시켜서 $\alpha$-CD존재 하에 분석한 효소가 가장 높아서 pH 2~5와 6~12에서 안정성이 매우 증가하였다. HPLC분석 결과 효소는 하나의 피크를 나타냈으며 변형시킨 것은 당결합으로 분자량이 커져서 유출시간이 약간 빨라졌다.

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ON THE EXTRACTION OF OPTICAL ROTATION CURVES FOR SPIRAL GALAXIES

  • Sohn, Young-Jonh;Rhee, Myung-Hyun;Chun, Mun-Suk
    • Journal of Astronomy and Space Sciences
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    • 제15권1호
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    • pp.27-38
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    • 1998
  • We discussed four different methods - the single, double and triple Gaussian fits, and the intensity weighted centroid fit - which extract rotation curves from several emis-sion lines(i.e. [OII], $H{\beta}$, [OIII], and $H{\alpha}$) of spiral galaxies. Spatial extents and the shapes of rotation curves derived through various methods applying to each emission lines of a sample galaxy UGC 11635 are all in a good agreement with one another. Linewidths of $H{\beta}$ and $H{\alpha}$ measure from rotation profiles are in a good agreement with $H{\alpha}$ linewidth of Courteau (1992). however, linewidths of [OII] seems to be much broader than $H{\alpha}$, and the profile of [OIII] does not follow the profile of $H{\alpha}$.

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耐熱性 ${\alpha}$-Amylase 高 生産性 Bacillus sp. No. 32H417의 分離 및 酵素 特性 (Isolation of Thermostable ${\alpha}$-Amylase Hyperproducing Bacillus sp. No. 32H417 and Some Properties of the Enzyme)

  • 김무성;오평수
    • 한국미생물·생명공학회지
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    • 제19권2호
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    • pp.122-127
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    • 1991
  • A bacterial strain NO. 32 which produced thermostable ${\alpha}$-amylase was isolated from soil and identified to genus of Bacillus. To enhance ${\alpha}$-amylase productivity, a successive mutation of Bacillus sp. No. 32 was attempted with treatment of N-methyl-N'-nitro-N-nitrosoguanidine (NTG). The resulting mutant, Bacillus sp. No. 32H417, which is risistant to refampicin and deficient in spore formation, produced about 90-fold high level of ${\alpha}$-amylase when compared with parental strain. The properties of the enzyme for thermostability were investigated. The optimal temperature and pH for enzyme reaction were 95$^{\circ}C$ and pH6.5, respectively, in the presence of 0.3mM $Ca^{2+}$ as an effective stabilizer.

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Kinetics of HMGB1 level changes in a canine endotoxemia model

  • Yu, Do-Hyeon;Park, Jinho
    • 대한수의학회지
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    • 제51권3호
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    • pp.239-241
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    • 2011
  • In this study, we investigated the kinetics of tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-6 and high mobility group box 1 (HMGB1) concentrations in a 48-h model of canine endotoxemia by lipopolysaccharide (LPS) injection. Four healthy beagles were slowly administered 1 mg/kg of LPS diluted in normal saline, while two others were administered normal saline as controls. Blood collection was performed at 0 h (baseline), 1 h and 3 h (for TNF-${\alpha}$), 6 h, 12 h, 24 h and 48 h of the experiment, and cytokine levels were determined using the sandwich ELISA method. Early increments of TNF-${\alpha}$ and IL-6 were observed (< 3 h), but HMGB1 levels increased the most at 12 h of the experiment and gradually decreased until 48 h. During the whole experiment, IL-6 and HMGB1 were sustained over 12 h of LPS injection, whereas TNF-${\alpha}$ decreased within 6 h of LPS injection. Taken together, canine HMGB1 levels increase relatively late (< 12 h) and sustained longer than TNF-${\alpha}$ and IL-6 in response to endotoxin. This is the first study to evaluate canine HMGB1 cytokine from endotoxemia in dogs.

NMR structural studies on Human CD99 Type I

  • Kim, Hai-Young;Kim, Young-Mee;Joon Shin;Shin, Young-Kee;Park, Seong-Hoe;Lee, Weontae
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 2003년도 정기총회 및 학술발표회
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    • pp.69-69
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    • 2003
  • Human CD99 is a ubiquitous 32-kDa transmembrane protein encoded by the mic2 gene. The major cellular functions of CD99 protein are related to homotypic cell adhension, apoptosis, vesicular protein transport, and differentiation of thymocytes or T cells. Recently it has been reported that expression of a splice variant of CD99 transmembrane protein (Type I and Type II) increases invasive ability of human breast cancer cells. To understand structural basis for cellular functions of CD99 (Type I), we have initiated studies on hCD99$^{TMcytoI}$ and hCD99$^{cytoI}$ using circular dichroism (CD) and multi-dimensional NMR spectroscopy. CD spectrum of hCD99$^{TMcytoI}$ in the presence of 200mM DPC and CHAPS displayed an existence $\alpha$-helical conformation. The solution structure of hCD99$^{cytoI}$ determined by NMR is composed of one N-terminal $\alpha$-helix, $\alpha$A, two C-terminal short $\alpha$-helix segments, $\alpha$B and $\alpha$C. While $\alpha$A and $\alpha$B are connected by the long flexible loop, $\alpha$B and $\alpha$C connected by type III$\beta$-turn. Although it has been rarely figured out the correlation between structure and functional mechanism of hCD99$^{TMcytoI}$ and hCD99$^{cytoI}$, there is possibility of dimerization or oligomerization. In addition, the feasible mechanism of hCD99$^{cytoI}$ is that it could have intramolecular interaction between the N- and C- terminal domain through large flexible AB loop.

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점망둑(Chasmichthys dolichognathus)의 성숙기 난모세포에서의 $C_{21}$-스테로이드 생성 (Production of $C_{21}$-Steroids in Longchin Goby, Chasmichthys dolichognathus during Oocyte Maturation)

  • 백혜자
    • 한국발생생물학회지:발생과생식
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    • 제12권1호
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    • pp.107-112
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    • 2008
  • 점망둑의 난모세포 성숙과정에서 생성되는 주요 성 스테로이드 호르몬, $C_{21}$-스테로이드를 분석하고자 전구물질 $^3H-17{\alpha}hydroxyprogesterone$ ($^3H-17{\alpha}OHP$)를 성숙기 난모세포(난경 $0.74{\sim}0.97\;mm$) 배양초기에 첨가하여 24시간 배양하였다. 스테로이드 대사물질 분석과 동정은 thin layer chromatography와 gaschromatography-mass spectrometry로 이루어졌다. $^3H-17{\alpha}20{\alpha}P$로부터 생성된 주요 성 스테로이드 대사물질은 $17{\alpha}$-hydroxy, $20{\alpha}$-dihydroprogesterone ($17{\alpha}20{\alpha}P$)와 $17{\alpha}$-hydroxy, $20{\beta}$-dihydroprogesterone ($17{\alpha}20{\beta}P$)로 확인되었다. 이들 대사물질은 난경 0.80 mm 이상에서 관찰되었으며, GVBD (germinal vesicle breakdown) 유도 효능 테스트에서 점망둑의 난모세포는 $17{\alpha}20{\beta}P$에 더 민감하게 반응하였다. 이러한 결과는 점망둑의 난소성숙 과정에 $17{\alpha}20{\alpha}P$$17{\alpha}20{\beta}P$이 모두 관여하나, MIS (maturation inducing steroid)로서의 가능성은 $17{\alpha}20{\beta}P$이 더 큰 것으로 관찰되었다.

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Protective Effects of $\alpha$-Tocopherol and Ischemic Preconditioning on Hepatic Reperfusion Injury

  • Lee Woo-Yang;Lee Sun-Mee
    • Archives of Pharmacal Research
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    • 제28권12호
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    • pp.1392-1399
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    • 2005
  • This study evaluated the effect of $\alpha$-tocopherol ($\alpha$-TC), ischemic preconditioning (IPC) or a combination on the extent of mitochondrial injury caused by hepatic ischemia/reperfusion (I/R). Rats were pretreated with $\alpha$-TC (20 mg/kg per day, i.p.) for 3 days before sustained ischemia. A rat liver was preconditioned with 10 min of ischemia and 10 min of reperfusion, and was then subjected to 90 min of ischemia followed by 5 h or 24 h of reperfusion. I/R increased the aminotransferase activity and mitochondrial lipid peroxidation, whereas it decreased the mitochondrial glutamate dehydrogenase activity. $\alpha$-TC and IPC individually attenuated these changes. $\alpha$-TC combined with IPC ($\alpha$-TC+IPC) did not further attenuate the changes. The mitochondrial glutathione content decreased after 5 h reperfusion. This decrease was attenuated by $\alpha$-TC, IPC, and $\alpha$-TC+IPC. The significant production of peroxides observed after 10 min reperfusion subsequent to sustained ischemia was attenuated by $\alpha$-TC, IPC, and $\alpha$-TC+IPC. The mitochondria isolated after I/R were rapidly swollen. However, this swelling rate was reduced by $\alpha$­TC, IPC, and $\alpha$-TC+IPC. These results suggest that either $\alpha$-TC or IPC reduces the level of mitochondrial damage associated with oxidative stress caused by hepatic I/R, but $\alpha$- TC combined with IPC offers no significant additional protection.