Regulation of Expression of the Bacillus caldolyticus Pyrimidine Biosynthetic Operon by pyrR Gene, an Autogenous Regulator

Ghim, Sa-Youl Korean Society of Life Science 2001 Journal of Life Science Vol.11 No.2

The pyrR gene of the pyrimidine biosynthesis (pyr) operon of the thermophile Bacillus caldolyticus, encoding a uracil phosphoribosyltransferase (UPRTase), turned to rely as a pyr operon regulator. It has been proposed that PyrR mediates transcriptional termination-antitermination at three intercistronic regions of the par operon (S.-Y Ghim and J. Neuhard, J. Bacteriol.,176, 3698-3707, 1994). In this research, a plasmid carrying the pyrR region of B. caldolyticus could restore a pyrimidine regulation in a pyrR mutant of B. subtilis. Expression of pyrR was found to increase 6-7 fold during pyrimidine starvation. Additionally, a highly conserved nucleotide sequence which may constitute the binding site for a PyrR protein (PyrR-binding loop) in transcript was staggested. Alternative antiterminator and terminator structures involving three conserved motifs in front of the pyrR, pyrP and pyrB genes, respectively, are proposed to account for the observed regulation pattern.

Dry Deposition of Reactive Nitrogen and Sulfur Compounds in the Greater Seoul Area

Ghim, Young Sung,Kim, Jin Young 한국화학공학회 2002 Korean Journal of Chemical Engineering Vol.19 No.1

While deposition is a removal process of pollutants from the atmosphere, it is an intake process of such pollutants into the ground. It is suggested that surface waters in the Greater Seoul Area, used as a source of drinking water, have been affected by severe air pollution. In this work, the dry deposition of reactive nitrogen and sulfur species was estimated for three typical days in each season for the year of 1997. The CIT (California Institute of Technology) photochemical model incorporated with a gaseous oxidation reaction of SO_2 was used. The study revealed that reactive nitrogen deposition was the largest in summer and sulfur deposition was the largest in winter. Most of the reactive nitrogen was deposited in the form of HNO_3 and NO_2, but HNO_3 deposition is highly dependent on the season according to the extent of photochemical production. On the other hand, the contribution of sulfate to the total deposition of sulfur was minimal partly because of low deposition velocity and of the neglect of possible inflow from the boundaries. Approximately 53% of the reactive nitrogen and 30% of the sulfur emitted in the study area was deposited in the ground in the dry form on an annual basis.

ADVANCED TREATMENT OF LEACHATE BY MEMBRANE PROCESSES

GHIM, Shijun,OZAKI, Hiroaki,TERASHIMA, Yutaka 嶺南大學校 環境問題硏究所 1996 環境硏究 Vol.16 No.1

AbstractIn this research, we present the treatment results ofleachates from landfill sites of municipal solid wastes or artificial incineration ash leachate by the process of ASMF (activated sludge process with microfiltiation membrane) combined with LPRO (low pressure reverse osmosis membrane). The LPRO showed a high removal of recaldttant substances and inorganic salts. However, this process is not appropriate fer the direct leachate treatment. Thus, the ASMF using ceramic membrane of the pore size of 0.1 fim was applied as a pretreatment process.As the result of experiments, it was found that these processes could effectively remove both recalcitrant substances and inorganic salts of leachates. For example, the treatment efficiencies of artificial. incineration ash leachate by ASMF combined with LPRO were 99 % ofCODcr, 55 %ofT-N, 70 % of calcium, and 53 % of sodium. Therefere, it was confirmed that the process of ASMF combined with LPRO can become an alternative to the physico-chemical process in conventional leachate treatment plant. In this research, we present the treatment results of leachates from landfill sites of municipal solid wastes or artificial incineration ash leachate by the process of ASMF (activated sludge process with microfiltration membrane) combined with LPRO (low pressure reverse osmosis membrane). The LPRO showed a high removal of recalcitrant substances and inorganic salts. However, this process is not appropriate for the direct leachate treatment. Thus, the ASMF using ceramic membrane of the pore size of 0.1㎛ was applied as a pretreatment process. As the result of experiments, it was found that these processes could effectively remove both recalcitrant substances and inorganic salts of leachates. For example, the treatment efficiencies of artificial incineration ash leachate by ASMF combined with LPRO were 99% of COD_cr, 55% of T-N, 70% of calcium, and 53% of sodium. Therefore, it was confirmed that the process of ASMF combined with LPRO can become an alternative to the physico-chemical process in conventional leachate treatment plant.

RAPID PURIFICATION AND MOLECULAR CHARACTERIZATION OF HUMAN NEUTROPHIL ELASTASE

Ghim, Sa-Youl,Bae, Sung Jun,Kang, Kooil 고신대학교 의학부 1989 高神大學校 醫學部 論文集 Vol.5 No.1

Elastase에 의해 야기되는 질병의 예방 및 치료 응용을 위하여는, 먼저 이 효소가 고순도로 분리되고 그 근본적인 성질의 해명이 이루어져야 한다. 고순도의 elastase를 얻기위해, 사람의 전혈로부터 Hypaque-Ficoll step gradient에 의해 순수한 neutrophil을 얻은 다음 이것을 extract로 만들어 액체크로마토그래피를 실시하였다. Ultrogel AcA54 gel filtration을 거친 후 CM-sephadex 이온교환 크로마토그래피를 적용하였는데, 이때 유출 완충액 속에 0.1% Brij 35를 첨가하여 elastase의 순도를 더욱 높일 수 있었다. 이 정제된 elastase는 SDS-PAGE를 통해 MW 28,000, 29,000, 30,000의 서로 다른 3개 의 밴드로 확인되었으며, 그간 수많은 연구자들간에 elastase의 분자량에 대해 심한 견해 차이를 보여온 것은 그 분자적 성질이나 분자량이 유사한 cathepsin G가 혼재하거나 elastase분자내 혹은 분자간 S-S결합의 차이에 의함을 알 수 있었다.

Spectrally resolved white-light interferometry for 3D inspection of a thin-film layer structure

Ghim, Young-Sik,Kim, Seung-Woo The Optical Society 2009 Applied Optics Vol.48 No.4

<P>We describe an improved scheme of spectrally resolved white-light interferometry, which provides 3D visual inspection of a thin-film layer structure with nanometer level resolutions. Compared to the authors' previous method [Appl. Phys. Lett.91, 091903 (2007)APPLAB0003-695110.1063/1.2776015], 3D tomographic information of thin films can be obtained by decoupling the film thickness and top surface profile, which is embodied by inducing spectral carrier frequency to the reference arm and applying a low-pass filter to the interferogram instead of two troublesome measurement steps of activating and deactivating a mechanical shutter. We test and verify our proposed method by measuring a patterned thin-film layer structure as well as standard specimens of thin films with various thicknesses.</P>

INHIBITION OF HUMAN NEUTROPHIL ELASTASE BY DIFFERENT CLASSES OF ANTIBIOTICS

Ghim, Sa-Youl,Kang, Kooil 고신대학교 의학부 1988 高神大學校 醫學部 論文集 Vol.4 No.1

사람의 혈액에 있는 호중구 엘라스테이즈에 관한 연구의 진척은, 약물로 사용가능한 생체내 혹은 인공합성의 저해제 개발을 동반해 오고 있다. 정제된 호중구 엘라스테이즈에 12종의 항생제를 처리하였더니 20mM 미만의 lC_(50)을 보인 것은 oxytetracycline, cefamandole, gentamicin, amikacin, cloxacillin, methicillin, chloramphenicol 등이었고, 10mM 농도에서 50% 이상의 저해율을 나타낸 것은 methicillin, cefamandole, oxytetracycline 등이었다. 그 결과는 세포벽 합성이나 단백질 합성을 저해하는 일반적 항생제의 약리학적 기전과는 다른 차원에서 항생제가 숙주의 조직을 보호할 수 있는 가능성을 보여준 모델이 존재한다는 것을 in vitro 실험에서 확인할 수 있었다.

Bias Correction for Forecasting PM2.5 Concentrations Using Measurement Data from Monitoring Stations by Region

Ghim, Young Sung,Choi, Yongjoo,Kim, Soontae,Bae, Chang Han,Park, Jinsoo,Shin, Hye Jung Korean Society for Atmospheric Environment 2018 Asian Journal of Atmospheric Environment (AJAE) Vol.12 No.4

Endothelial Deletion of Phospholipase D2 Reduces Hypoxic Response and Pathological Angiogenesis

Ghim, Jaewang,Moon, Jin-Sook,Lee, Chang Sup,Lee, Junyeop,Song, Parkyong,Lee, Areum,Jang, Jin-Hyeok,Kim, Dayea,Yoon, Jong Hyuk,Koh, Young Jun,Chelakkot, Chaithanya,Kang, Byung Jun,Kim, Jung-Min,Kim, Ky American Heart Association, Inc. 2014 Arteriosclerosis, thrombosis, and vascular biology Vol.34 No.8

<P><B>Objective—</B></P><P>Aberrant regulation of the proliferation, survival, and migration of endothelial cells (ECs) is closely related to the abnormal angiogenesis that occurs in hypoxia-induced pathological situations, such as cancer and vascular retinopathy. Hypoxic conditions and the subsequent upregulation of hypoxia-inducible factor-1α and target genes are important for the angiogenic functions of ECs. Phospholipase D2 (PLD2) is a crucial signaling mediator that stimulates the production of the second messenger phosphatidic acid. PLD2 is involved in various cellular functions; however, its specific roles in ECs under hypoxia and in vivo angiogenesis remain unclear. In the present study, we investigated the potential roles of PLD2 in ECs under hypoxia and in hypoxia-induced pathological angiogenesis in vivo.</P><P><B>Approach and Results—</B></P><P><I>Pld2</I> knockout ECs exhibited decreased hypoxia-induced cellular responses in survival, migration, and thus vessel sprouting. Analysis of hypoxia-induced gene expression revealed that PLD2 deficiency disrupted the upregulation of hypoxia-inducible factor-1α target genes, including <I>VEGF</I>, <I>PFKFB3</I>, <I>HMOX-1</I>, and <I>NTRK2</I>. Consistent with this, PLD2 contributed to hypoxia-induced hypoxia-inducible factor-1α expression at the translational level. The roles of PLD2 in hypoxia-induced in vivo pathological angiogenesis were assessed using oxygen-induced retinopathy and tumor implantation models in endothelial-specific <I>Pld2</I> knockout mice. <I>Pld2</I> endothelial-specific knockout retinae showed decreased neovascular tuft formation, despite a larger avascular region. Tumor growth and tumor blood vessel formation were also reduced in <I>Pld2</I> endothelial-specific knockout mice.</P><P><B>Conclusions—</B></P><P>Our findings demonstrate a novel role for endothelial PLD2 in the survival and migration of ECs under hypoxia via the expression of hypoxia-inducible factor-1α and in pathological retinal angiogenesis and tumor angiogenesis in vivo.</P>

Evaluation of Model Performance for Forecasting Fine Particle Concentrations in Korea

Ghim, Young Sung,Choi, Yongjoo,Kim, Soontae,Bae, Chang Han,Park, Jinsoo,Shin, Hye Jung Taiwan Association for Aerosol Research 2017 Aerosol and air quality research Vol.17 No.7

Experimental evaluation of the in-tube condensation heat transfer of pure n-pentane/R245fa and their non-azeotropic mixture as an ORC working fluid

Ghim, G.,Lee, J. Pergamon ; Elsevier Science Ltd 2016 Applied thermal engineering Vol.106 No.-

The existence of temperature gliding in non-azeotropic mixture working fluids provides a promising opportunity for greatly improved resource utilization in organic Rankine cycle (ORC) systems for geothermal applications. The condensation heat transfer degradation associated with working fluid mixtures is an unavoidable penalty that may reduce the utilization and system benefits by necessitating larger heat exchangers. The objective of the current study is an experimental investigation of condensation heat transfer for R245fa, n-pentane, and a composition of their mixture. Quasi-local condensation heat transfer coefficients are measured in a straight horizontal smooth tube with flow conditions at mass flux G=100 and 150kg(m<SUP>2</SUP>s)<SUP>-1</SUP>, local equilibrium quality x=0.05-0.80, and reduced pressures P<SUB>r</SUB>=0.05-0.15. The reduced condensation heat transfer coefficients from the test are compared with the predictions from already established mixture correction methods in the literature. Pure components R245fa and n-pentane condensation heat transfer data are well predicted by Shah (1979) correlations for all test conditions. However, their non-azeotropic mixture condensation heat transfer data require additional correction parameter to account for the heat transfer degradation. This correction parameter is correlated by the temperature gliding gradient of mixture fluids. Test data with mixture working fluids from current study are reasonably well predicted by the corrected in-tube correlation.