• Title/Summary/Keyword: RV

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Design Verification of APR1400 Reactor Vessel Through Re-engineering Approach

  • Mutembei, Mutegi Peter;Namgung, Ihn
    • Journal of the Korean Society of Systems Engineering
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    • v.13 no.1
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    • pp.15-23
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    • 2017
  • This paper describes verification of APR1400 reactor vessel by applying the system engineering approach, in which the design re-engineering method is used to check the design parameters of APR1400 RV (reactor vessel). The RV is classified as safety class 1 and therefore must adhere strictly to the rules of ASME BPVC section III, subsection NB and seismic category I. This study explores designing the RV by following the ASME guidelines and making a comparative study with the current design. To meet this objective we apply system engineering methodologies to structure the process and allow for verification and validation of the major RV design parameters such as thickness of RV. The structural thicknesses of various part of RV are determined as well as reinforcements on the RV major nozzles. A 3D virtual reality model was created based on the design parameters using CATIA V5 and animation using Dassault Composer V2016. A comparison of re-engineered ARP1400 RV and standard APR1400 RV was done to show which design parameters were taken more conservative approach.

Rv3168 Phosphotransferase Activity Mediates Kanamycin Resistance in Mycobacterium tuberculosis

  • Ahn, Jae-Woo;Kim, Kyung-Jin
    • Journal of Microbiology and Biotechnology
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    • v.23 no.11
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    • pp.1529-1535
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    • 2013
  • Tuberculosis is a worldwide epidemic disease caused by Mycobacterium tuberculosis, with an estimated one-third of the human population currently affected. Treatment of this disease with aminoglycoside antibiotics has become less effective owing to antibiotic resistance. Recent determination of the crystal structure of the M. tuberculosis Rv3168 protein suggests a structure similar to that of Enterococcus faecalis APH(3')-IIIa, and that this protein may be an aminoglycoside phosphotransferase. To determine whether Rv3168 confers antibiotic resistance against kanamycin, we performed dose-response antibiotic resistance experiments using kanamycin. Expression of the Rv3168 protein in Escherichia coli conferred antibiotic resistance against $100{\mu}M$ kanamycin, a concentration that effected cell growth arrest in the parental E. coli strain and an E. coli strain expressing the $Rv3168^{D249A}$ mutant, in which the catalytic Asp249 residue was mutated to alanine. Furthermore, we detected phosphotransferase activity of Rv3168 against kanamycin as a substrate. Moreover, docking simulation of kanamycin into the Rv3168 structure suggests that kanamycin fits well into the substrate binding pocket of the protein, and that the phosphorylation-hydroxyl-group of kanamycin was located at a position similar to that in E. faecalis APH(3')-IIIa. On the basis of these results, we suggest that the Rv3168 mediates kanamycin resistance in M. tuberculosis, likely through phosphotransferase targeting of kanamycin.

Integration of a target gene into chromosomal genome of BF-2 cells using UV-inactivated snakehead retrovirus (SnRV)

  • Kwon, Se-Ryun;Nishizawa, Toyohiko;Yoshimizu, Mamoru
    • Journal of fish pathology
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    • v.22 no.3
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    • pp.375-382
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    • 2009
  • Integration and expression of a target gene into chromosomal genomes of host cell by retrovirus mediated gene transfer system usually require complicate and laborious procedures. In the present study, we investigate a simple method to integrate a target gene into genome of BF-2 cells using ultraviolet (UV)-inactivated snakehead retrovirus (SnRV), a fish retrovirus. First of all, an optimization of transfection condition was determined with BF-2 cells using Lipofectamine 2000 and Transome. Using 0.5 $\mu\ell$ Lipofectamine 2000 resulted in 33.8, 40.6 and 40.2% of transfection efficacy with high survival rate (minimum 80%) in 0.5, 1 and 2 $\mu{g}$ DNA, respectively, and those of Transome were all less than 5%. It was confirmed that UV-treatment for 5 min was enough to inactivate infectivity of SnRV. Next, a cassette composed of GFP (green fluorescent protein) gene flanked by LTR (long terminal repeats) sequences derived from SnRV was constructed and transfected into BF-2 cells followed by treatment with UV-inactivated SnRV for optimization of integration and expression of the cassette gene. As the results, the fluorescence was expressed in BF-2 cells treated with UV-inactivated SnRV 3 and 5 times, while there was no expression in BF-2 cells with once and non treatment. Accordingly, it was confirmed that GFP gene was integrated into chromosomal genome of BF-2 cells with UV-inactivated SnRV.

Right-sided heart failure in congenital heart diseases (선천성 심질환에서 우심부전)

  • Jung, Jo Won
    • Clinical and Experimental Pediatrics
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    • v.50 no.11
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    • pp.1055-1060
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    • 2007
  • Right-sided heart failure is a major problem among patients with congenital heart diseases, due to the prevalence of congenital heart defects and the association of pulmonary hypertension. More attention is focused on the structure of the right heart particularly in association with congenital heart defects and chronic lung disease. The right ventricle (RV) may support the pulmonary circulation, and sometimes the systemic circulation (systemic RV) in congenital heart defects. Despite major progress being made, assessing the RV remains challenging, often requiring a multi-imaging approach and expertise (echocardiography, magnetic resonance imaging, nuclear and cineangiography). Evidence is accumulating that RV dysfunction develops in many of these patients and leads to considerable morbidity and mortality. While there is extensive literature on the pathophysiology and treatment of left heart failure, the data for right-sided heart failure is scarce. Therefore RV function in certain groups of congenital heart disease patients needs close surveillance and timely and appropriate intervention to optimise outcomes. An understanding of RV physiology and hemodynamics will lead to a better understanding of current and future treatment strategies for right heart failure. This will review right-sided heart failure with the implications of volume and pressure loading of the RV in congenital heart diseases.

Cumulus Oocyte Complex Expansion Inhibiting Ingredient in Porcine Follicular Fluid (돼지 난포액내 난구세포 난자복합체 팽창 억제 성분)

  • 오현주;김은희;손채은;이은주;박영식
    • Journal of Embryo Transfer
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    • v.15 no.3
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    • pp.203-210
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    • 2000
  • The objective of this study was to identify a follicular fluid ingredient inhibiting the cumulus oocyte complex (COC) expansion. Thus, follicular fluid or liquid chromatographic fractions of follicular fluid was supplemented in COC culture medium. And COCs were incubated for 48 hours to investigate about cumulus expansion and also the first polar body extrusion. The results obtained were as follows; 1. The fluid of medium follicle significantly inhibited the COC expansion. 2. The fluid of large follicle inhibited the COC expansion. 3. Follicular fluid showed six major fractions at retention volumes (RVs) 1.83, 1.91, 2.15, 2.34, 2.53 and 2.74 ml after separation with Superose 12 column. Of the major fractions, fractions RV2.15, RV2.34, RV2.53 and RV2.74 inhibited both COC expansion and polar body extrusion. Especially, fractions of RV2.15 and RV2.53 significantly inhibited COC expansion, oocyte denudation and polar body extrusion. In conclusion, porcine follicular fluid contained a COC expansion inhibiting ingredient (CEI) that may be contained largely in fractions RV2.15 and RV2.53. And CEI may inhibit oocyte maturation by inhibition of oocyte denudation and extrusion of the first polar body.

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Nucleotide sequence analysis and expression of NSP4 gene of avian rotavirus (조류 로타바이러스의 NSP4 유전자 염기서열분석 및 발현)

  • Shin, In-ho;Lee, Seung-chul;Kim, Won-yong;Kang, Shien-young
    • Korean Journal of Veterinary Research
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    • v.45 no.2
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    • pp.207-214
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    • 2005
  • The nonstructural protein 4 (NSP4) of rotavirus encoded by gene 10, plays an important role in rotavirus pathogenicity. In this study, NSP4 gene of avian rotavirus (AvRV-1, AvRV-2) was analyzed and expressed using baculovirus expression system. The sequence data indicated that the NSP4 gene of AvRV-1 and AvRV-2 were 727 bases in length, encoded one open reading frame of 169 amino acids beginning at base 41 and terminating at base 550, and had two glycosylation sites. Nucleotide sequences of NSP4 gene of AvRV-1 and AvRV-2 exhibited a high degree of homology ($88.1{\pm}7.6%$) with avian rotaviruses, namely Ty1, Ty3 and PO-13. Phylogenetic analysis showed that AvRV-1 and AvRV-2 belonged to genotype NSP4[E], which is widely found in group A avian rotaviruses. The baculovirus-expressed NSP4 migrated at 20-28 kDa and reacted with NSP4-specific antiserum by FA and Western blot. Furthermore, it was found to be a glycoprotein by using tunicamycin, which is a specific inhibitor of N-linked glycosylation.

Pulmonary stenosis and pulmonary regurgitation: both ends of the spectrum in residual hemodynamic impairment after tetralogy of Fallot repair

  • Yoo, Byung Won;Park, Han Ki
    • Clinical and Experimental Pediatrics
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    • v.56 no.6
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    • pp.235-241
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    • 2013
  • Repair of tetralogy of Fallot (TOF) has shown excellent outcomes. However it leaves varying degrees of residual hemodynamic impairment, with severe pulmonary stenosis (PS) and free pulmonary regurgitation (PR) at both ends of the spectrum. Since the 1980s, studies evaluating late outcomes after TOF repair revealed the adverse impacts of residual chronic PR on RV volume and function; thus, a turnaround of operational strategies has occurred from aggressive RV outflow tract (RVOT) reconstruction for complete relief of RVOT obstruction to conservative RVOT reconstruction for limiting PR. This transformation has raised the question of how much residual PS after conservative RVOT reconstruction is acceptable. Besides, as pulmonary valve replacement (PVR) increases in patients with RV deterioration from residual PR, there is concern regarding when it should be performed. Regarding residual PS, several studies revealed that PS in addition to PR was associated with less PR and a small RV volume. This suggests that PS combined with PR makes RV diastolic property to protect against dilatation through RV hypertrophy and supports conservative RVOT enlargement despite residual PS. Also, several studies have revealed the pre-PVR threshold of RV parameters for the normalization of RV volume and function after PVR, and based on these results, the indications for PVR have been revised. Although there is no established strategy, better understanding of RV mechanics, development of new surgical and interventional techniques, and evidence for the effect of PVR on RV reverse remodeling and its late outcome will aid us to optimize the management of TOF.

Altered Functions of Adrenoceptors in Splanchnic Vascular Beds in Portal Hypertensive Rat Model: Effect of Propranolol (문맥 고혈압 흰쥐에 있어서 내장혈관의 아드레나린성 수용체의 기능변동과 이에 대한 Propranolol의 효과)

  • Kim, Chi-Dae;Hong, Ki-Whan
    • The Korean Journal of Pharmacology
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    • v.24 no.1
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    • pp.63-70
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    • 1988
  • Alterations in splanchnic circulatory hemodynamics along with reactivities to the alpha adrenoceptor agonists were assessed in association with the preventive effects of propranolol 10 days after portal ligation. Decreases in precapillary resistance (Ra) and postcapillary resistance (Rv) along with increases in mesenteric blood flow (MBF) and capillary pressure (CP) were observed in conjunction with an increment of splenic pulp pressure (SPP). Dose-dependent increase in Rv in response to noradrenaline, increases in Ra and RV to adrenaline, and increases in superior mesenteric arterial pressure (SMAP), Ra and Rv to phenylephrine observed in sham group were significantly attenuated by portal vein stenosis. In PPL-3 group (propranolol 3 mg/kg, i.p. three times daily for 10 days), MBF was significantly decreased in association with decrease in mesenteric venous pressure (MVP) when compared with those of protal ligated (PL) group, and decreased Ra and Rv in PL group were recovered toward the values of sham group. Likewise, in PPL-1 group (propranolol 5 mg/kg, i.p. once daily for 10 days), the pressor response of Rv to adrenaline was recovered up to the level of sham group. Thus, it is suggested that decreases in Ra and Rv in association with increases in MBF and CP may have a close relevance to the increased SPP, and the changes in circulatory hemodynamics and vascular reactivities were effectively reversed by longterm propranolol treatment. Based on these results, it is concluded that these changes observed in portal hypertension are closely related with the altered functions of the adrenoceptors in the splanchnic vascular beds.

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Rotavirus-associated neonatal necrotizing enterocolitis (로타바이러스 감염이 관련된 신생아 괴사성 장염)

  • Seo, Hyun Joo;Jung, Yu Jin;Park, Soo Kyung;Choi, Seo Hui;Lee, Ji Hyuk;Kim, Myo Jing;Chang, Yun Sil;Park, Won Soon
    • Clinical and Experimental Pediatrics
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    • v.52 no.1
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    • pp.56-60
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    • 2009
  • Purpose : This study aimed to test whether rotavirus-associated necrotizing enterocolitis (RV+NEC) produced different clinical findings or outcomes from those of non-rotavirus necrotizing enterocolitis (RV-NEC). Methods : Eight patients from the RV+NEC group and 22 patients from the RV-NEC group diagnosed with modified Bell stage II or higher NEC were selected for this study. Fecal specimens from all infants were tested for rotavirus infection using a monoclonal antibody-based enzyme immunoassay (EIA). Clinical, radiographic, and clinical outcome data were analyzed retrospectively. Results : RV+NEC infants had a significantly higher birth weight and were born at a significantly higher gestational age ($33.5{\pm}3.3$ weeks vs. $29.3{\pm}4.4$ weeks; P=0.01). There were no differences in the occurrence of thrombocytopenia, mural gas, and pneumoperitoneum between the 2 groups. However, portal vein gas was more common in the RV+NEC group (88% vs. 9%; P<0.01). Neither the incidence of Bell stage III (or higher) NEC nor surgical intervention differed between the two groups. The number of complications and mortality rates were also similar. Conclusion : Rotavirus-associated NEC occurs in infants with a higher birth weight and those born at a greater gestational age. However, the severity of the condition and the resulting outcomes did not differ from those for infants affected by non-rotavirus NEC.

A threshold-asymmetric realized volatility for high frequency financial time series (비대칭형 분계점 실현변동성의 제안 및 응용)

  • Kim, J.Y.;Hwang, S.Y.
    • The Korean Journal of Applied Statistics
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    • v.31 no.2
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    • pp.205-216
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    • 2018
  • This paper is concerned with volatility computations for high frequency time series. A threshold-asymmetric realized volatility (T-RV) is suggested to capture a leverage effect. The T-RV is compared with various conventional volatility computations including standard realized volatility, GARCH-type volatilities, historical volatility and exponentially weighted moving average volatility. High frequency KOSPI data are analyzed for illustration.