http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
The H <small>i</small> environment of counter‐rotating gas hosts: gas accretion from cold gas blobs
Chung, Aeree,Bureau, Martin,van Gorkom, J. H.,Koribalski, Bä,rbel Blackwell Publishing Ltd 2012 Monthly notices of the Royal Astronomical Society Vol.422 No.2
<P><B>ABSTRACT</B></P><P>We probe the H <SMALL>i</SMALL> properties and the gas environments of three early‐type barred galaxies harbouring counter‐rotating ionized gas: NGC 128, NGC 3203 and NGC 7332. Each system has one or more optically identified galaxy at a similar or as yet unknown redshift within a 50‐kpc projected radius. Using H <SMALL>i</SMALL> synthesis imaging data, we investigate the hypothesis that the counter‐rotating gas in these galaxies has been accreted from their neighbours. In NGC 128 and NGC 3203, we find 9.6 × 10<SUP>7</SUP> and 2.3 × 10<SUP>8</SUP> M<SUB>⊙</SUB> of H <SMALL>i</SMALL>, respectively, covering almost the entire stellar bodies of dwarf companions that appear physically connected. Both the H <SMALL>i</SMALL> morphology and kinematics are suggestive of tidal interactions. In NGC 7332, we do not find any directly associated H <SMALL>i</SMALL>. Instead, NGC 7339, a neighbour of a comparable size at about 10 kpc, is found with 8.9 × 10<SUP>8</SUP> M<SUB>⊙</SUB> of H <SMALL>i</SMALL> gas. More recently in a single dish observation, however, another group discovered a large H <SMALL>i</SMALL> structure which seems to be an extension of NGC 7339’s H <SMALL>i</SMALL> disc and also covers NGC 7332. All these observations thus suggest that H <SMALL>i</SMALL> gas is being accreted in these three galaxies from their companions, which is likely responsible for the kinematically decoupled gas component present in their central region. In particular, the dynamical friction time‐scales of the nearest neighbours with H <SMALL>i</SMALL> gas of NGC 128 and NGC 3203 are comparable to their orbital time‐scales around the counter‐rotators, several ∼10<SUP>8</SUP> yr, implying that those neighbours will likely soon merge with the primary galaxies, fuelling them with gas. NGC 7332 also appears to be in the merging process with its neighbour through the common H <SMALL>i</SMALL> envelope. Besides, we find some other potential gas donors around NGC 128 and NGC 7332: two H <SMALL>i</SMALL>‐rich galaxies with <IMG src='/wiley-blackwell_img/equation/MNR_20679_mu1.gif' alt ='inline image'/> and 2.5 × 10<SUP>9</SUP> M<SUB>⊙</SUB> at a distance of ≈67 kpc from NGC 128 and two dwarf systems with <I>M</I><SUB>HI</SUB>= 3.9 × 10<SUP>7</SUP> and 7.4 × 10<SUP>7</SUP> M<SUB>⊙</SUB> at ≲100 kpc from NGC 7332. Among the seven H <SMALL>i</SMALL> features identified in this study, three of them are associated with dwarf galaxies, two of which have only been recently identified in a blind survey, while the third one is still not catalogued at optical wavelengths. Considering the incompleteness of existing studies of the faint dwarf galaxy population both in the optical and in H <SMALL>i</SMALL>, accretion from cold gas blobs, presumably gas‐rich dwarfs, is expected to occur even more frequently than what is inferred from such cases that have been observed to date.</P>
Aggravation of post-ischemic liver injury by overexpression of A20, an NF-κB suppressor
Yu, J.,Lee, H.S.,Lee, S.M.,Yu, H.C.,Moon, W.S.,Chung, M.J.,Park, J.W.,Park, B.H. Elsevier Science Publishers 2011 Journal of hepatology Vol.55 No.2
Backgroud & Aims: A20 is an intracellular ubiquitin-editing enzyme that plays an important role in the negative feedback regulation of NF-κB activation in response to a diverse range of stimuli. Liver ischemia/reperfusion injury is associated with rapid activation of NF-κB signaling, but the role of NF-κB in hepatic ischemia/reperfusion injury remains controversial. The NF-κB signaling pathway mediates both protective and deleterious effects in the liver. Here, we examined whether A20 inhibited or aggravated hepatic ischemia/reperfusion injury. Methods: We used IκBα super-repressor as a positive control and overexpressed A20 and IκBα super-repressor in the liver of C57BL/6 mice. Mice underwent 45min of partial hepatic ischemia and were then reperfused. Results: Protein level of A20 was increased after reperfusion. Mice subjected to ischemia/reperfusion injury showed increased NF-κB activation, as evidenced by phosphorylation of IκBα and nuclear translocation of NF-κB. Prior transfection with Ad-A20 or Ad-IκBα super-repressor attenuated NF-κB activation and aggravated liver injury. Serum aminotransferases and proinflammatory cytokines, hepatocellular necrosis, and hepatic neutrophil infiltration were markedly increased compared to those of uninfected or control virus infected mice. In addition, A20 abolished the beneficial effect of ischemic preconditioning. Conclusions: Our results suggest that inhibition of NF-κB activation by A20 aggravated partial hepatic ischemia/reperfusion injury. Understanding how the NF-κB pathway plays a role in directing a clinical outcome may lead to better prospects of more rational approaches to reduce post-ischemic liver injury.
Chung, D.B.,Kim, H.Y.,Jeon, M.,Lee, D.H.,Park, H.S.,Choi, S.H.,Nam, S.W.,Jang, S.C.,Park, J.H.,Lee, K.Y.,Yoon, C.W. Pergamon Press ; Elsevier Science Ltd 2017 International journal of hydrogen energy Vol.42 No.3
<P>Ru (1.0 wt% loaded)-based catalysts supported on La(x)-Al2O3 (x = 0,1, 5,10, and 50 mol%) were synthesized and characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) measurement, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), and temperature programmed reduction (TPR). The as-prepared La(x)-Al2O3 materials were found to have increased amounts of the LaAlO3 phase as the La doping level (x) increased from 0 to 50 mol%. In addition to metal-to support interactions between Ru and Al2O3, the newly formed LaAlO3 phase in the Ru catalysts was proposed to interact strongly with Ru active sites based on the XRD, H-2-TPR and XPS results. The Ru/La(x)-Al2O3 catalysts were active for the dehydrogenation of ammonia, and among them, the Ru/La(10)-Al2O3 and Ru/La(50)-Al2O3 (or Ru/LaAlO3) catalysts exhibited superior performance with >96% conversions of ammonia at 550 degrees C. When an increased Ru content (2.0 wt%) was impregnated onto La(10)-Al2O3, the dehydrogenation activity was significantly improved with nearly 100% conversion (>95%) of ammonia at 500 degrees C. This catalyst further displayed an enhanced thermal stability towards ammonia decomposition with the GHSV(NH3) of 10,000 mL/g(cat)h at 550 degrees C for >120 h. The incorporated element La is thought to play an important role in enhancing metal-support interaction, ultimately facilitating ammonia dehydrogenation even at low temperatures. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.</P>
H-Y 에 대한 단일클론 항체의 생산 및 그 이용에 관한 연구 1 . H-Y 에 대한 단일클론항체의 생산
심호섭(H . S . Shim),김재화(J . H . Kim),이병철(B . C . Lee),김종배(J . B . Kim),박홍양(H . Y . Park),정길생(K . S . Chung) 한국축산학회 1988 한국축산학회지 Vol.30 No.7
Testis supernatant, a source of H-Y, obtained from BALB/c mice was used to immunize females of same strain. B lymphocytes of mouse producing antibodies to H-Y were fused with SP2/0-Ag 14 myeloma cells and distributed to 384 wells of 96-well microtiter plates. Eighty hybridoma colonies were formed, resulting in 20.8 percent of fusion efficiency. Three strong positive wells from hybridoma colonies were selected for cloning by ELISA and two of them were also found to be positive by indirect immunofluorescence test. Twelve wells of ELISA-positive were selected after cloning and 2D45D4 clones from them were confirmed to produce monoclonal antibodies to H-Y by indirect immunofluorescence test.
최재혁,B. C. Choi,S. M. Lee,S. H. CHUNG,K. S. Jung,W. L. Jeong,S. K. Choi,S. K. Park 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.5
In order to investigate the effect of DME mixing on the number density and size of soot particles, DME was mixed in a counter flownon-premixed ethylene flame with mixture ratios of 5%, 14% and 30%. A laser extinction/scattering technique has been adopted tomeasure the volume fraction, number density, and mean size of soot particles. The experimental results showed that the highest soot concentrationswere observed for flames with mixture ratios of 5% and 14%; however, for a mixture ratio of 30% the soot concentrationdecreased. Numerical results showed that the concentrations of propargyl radicals (C3H3) at the 5% and 14% ratios were higher thanthose measured in the ethylene-based flame, and the production of benzene (C6H6) in the 5% and 14% DME mixture flames was alsoincreased. This indicates the crucial role of propargyl in benzene ring formation. These reactions generally become stronger with increasedDME mixing, except for A1 + H2 → A1 + H (-R554) and n-C4H5 + C2H2 → A1 + H (R542). Therefore, it is indicated that addingDME to ethylene flames promotes benzene ring formation. Note that although the maximum C6H6 concentration is largest in the 30%DME mixing flame, the soot volume fraction is smaller than those for the 5% and 14% mixture ratios. This is because the local C6H6concentration decreases in the relatively low temperature region in the fuel side where soot growth occurs.
Kim, B.M.,Choi, J.Y.,Kim, Y.J.,Woo, H.D.,Chung, H.W. North-Holland Pub ; Elsevier Science Ltd 2007 FEBS letters Vol.581 No.16
Cellular responses to DNA damage after hypoxia and reoxygenation (H/R) were examined in human lymphocytes. Cultured lymphocytes exposed to H/R showed a lower cytokinesis block proliferation index and a higher frequency of micronuclei in comparison to control cells. Western blots showed that H/R exposure induced p53 expression; however, p21 and Bax expression did not increase, indicating that H/R did not affect p53 transactivational activity. Phosphorylation of p53 (Ser15), Chk1 (Ser345), and Chk2 (Thr68) was also observed, suggesting that H/R activates p53 through checkpoint signals. In addition, H/R exposure caused the phosphorylation and negative regulation of Cdc2 and Cdc25C, proteins that are involved in cell-cycle arrest at the G2/M checkpoint. The S-phase checkpoint, regulated by the ATM-p95/NBS1-SMC1 pathway, was also triggered in H/R-exposed lymphocytes. These results demonstrate that H/R exposure triggers checkpoint signaling and induces cell-cycle arrest in cultured human lymphocytes.