• Nuclear Engineering and Technology
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• 제53권8호
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• pp.2534-2546
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• 2021

Nuclear emergency preparedness and response is an essential part to ensure the safety of nuclear power plant (NPP). Key support technologies of nuclear emergency decision-making usually consist of accident diagnosis, source term estimation, accident consequence assessment, and protective action recommendation. Source term estimation is almost the most difficult part among them. For example, bad communication, incomplete information, as well as complicated accident scenario make it hard to determine the reactor status and estimate the source term timely in the Fukushima accident. Subsequently, it leads to the hard decision on how to take appropriate emergency response actions. Hence, this paper aims to develop a method for rapid source term estimation to support nuclear emergency decision making in pressurized water reactor NPP. The method aims to make our knowledge on NPP provide better support nuclear emergency. Firstly, this paper studies how to build a Bayesian network model for the NPP based on professional knowledge and engineering knowledge. This paper presents a method transforming the PRA model (event trees and fault trees) into a corresponding Bayesian network model. To solve the problem that some physical phenomena which are modeled as pivotal events in level 2 PRA, cannot find sensors associated directly with their occurrence, a weighted assignment approach based on expert assessment is proposed in this paper. Secondly, the monitoring data of NPP are provided to the Bayesian network model, the real-time status of pivotal events and initiating events can be determined based on the junction tree algorithm. Thirdly, since PRA knowledge can link the accident sequences to the possible release categories, the proposed method is capable to find the most likely release category for the candidate accidents scenarios, namely the source term. The probabilities of possible accident sequences and the source term are calculated. Finally, the prototype software is checked against several sets of accident scenario data which are generated by the simulator of AP1000-NPP, including large loss of coolant accident, loss of main feedwater, main steam line break, and steam generator tube rupture. The results show that the proposed method for rapid source term estimation under nuclear emergency decision making is promising.

• 한국압력기기공학회 논문집
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• 제9권1호
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• pp.15-19
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• 2013

The auxiliary feedwater is an important to remove the heat from the reactor core when the main feedwater system is unavailable. In most initiating events in Probabilistic Safety Assessment(PSA), the operaton of this system is required to mitigate the accidents. For one of domestic nuclear power plants, a design change of a turbine-driven auxiliary feedwater pump(TD-AFWP), pipe, and valves in the auxiliary system is implemented due to the aging related deterioration by long time operation. This change includes the replacement of the TD-AFWP, the relocation of some valves for improving the system availability, a new cross-tie line, and the installation of manual valves for maintenance. The design modification affects the PSA because the system is critical to mitigate the accidents. In this paper, the safety effect of the change of the auxiliary feedwater system is assessed with regard to the PSA view point. The results demonstrate that this change can supply the auxiliary feedwater from the TD-AFWP in the accident with the motor-driven auxiliary feedwater pump(MD-AFWP) unavailable due to test or maintenance. In addition, the change of MOV's normal position from "close" to "open" can deliver the water to steam generator in the loss of offsite power(LOOP) event. Therefore, it is confirmed that the design change of the auxiliary feedwater system reduces the total core damage frequency(CDF).

• 한국발생생물학회지:발생과생식
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• 제24권4호
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• pp.297-306
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• 2020

Repetitive changes in the intracellular calcium concentration ([Ca²⁺]i) triggers egg activation, including cortical granule exocytosis, resumption of second meiosis, block to polyspermy, and initiating embryonic development. [Ca²⁺]i oscillations that continue for several hours, are required for the early events of egg activation and possibly connected to further development to the blastocyst stage. The sources of Ca²⁺ ion elevation during [Ca²⁺]i oscillations are Ca²⁺ release from endoplasmic reticulum through inositol 1,4,5 tri-phosphate receptor and Ca²⁺ ion influx through Ca²⁺ channel on the plasma membrane. Ca²⁺ channels have been characterized into voltage-dependent Ca²⁺ channels (VDCCs), ligand-gated Ca²⁺ channel, and leak-channel. VDCCs expressed on muscle cell or neuron is specified into L, T, N, P, Q, and R type VDCs by their activation threshold or their sensitivity to peptide toxins isolated from cone snails and spiders. The present study was aimed to investigate the localization pattern of N and P/Q type voltage-dependent calcium channels in mouse eggs and the role in fertilization. [Ca²⁺]i oscillation was observed in a Ca²⁺ contained medium with sperm factor or adenophostin A injection but disappeared in Ca²⁺ free medium. Ca²⁺ influx was decreased by Lat A. N-VDCC specific inhibitor, ω-Conotoxin CVIIA induced abnormal [Ca²⁺]i oscillation profiles in SrCl₂ treatment. N or P/Q type VDC were distributed on the plasma membrane in cortical cluster form, not in the cytoplasm. Ca²⁺ influx is essential for [Ca²⁺]i oscillation during mammalian fertilization. This Ca²⁺ influx might be controlled through the N or P/Q type VDCCs. Abnormal VDCCs expression of eggs could be tested in fertilization failure or low fertilization eggs in subfertility women.

• Journal of Ginseng Research
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• 제43권3호
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• pp.452-459
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• 2019

Background: Ginsenoside compound K(C-K), a major metabolite of ginsenoside, exhibits anticancer activity in various cancer cells and animal models. A cell signaling study has shown that C-K inhibited nuclear factor-kappa B ($NF-{\kappa}B$) pathway in human astroglial cells and liver cancer cells. However, the molecular targets of C-K and the initiating events were not elucidated. Methods: Interaction between C-K and Annexin A2 was determined by molecular docking and thermal shift assay. HepG2 cells were treated with C-K, followed by a luciferase reporter assay for $NF-{\kappa}B$, immunofluorescence imaging for the subcellular localization of Annexin A2 and $NF-{\kappa}B$ p50 subunit, coimmunoprecipitation of Annexin A2 and $NF-{\kappa}B$ p50 subunit, and both cell viability assay and plate clone formation assay to determine the cell viability. Results: Both molecular docking and thermal shift assay positively confirmed the interaction between Annexin A2 and C-K. This interaction prevented the interaction between Annexin A2 and $NF-{\kappa}B$ p50 subunit and their nuclear colocalization, which attenuated the activation of $NF-{\kappa}B$ and the expression of its downstream genes, followed by the activation of caspase 9 and 3. In addition, the overexpression of Annexin A2-K320A, a C-K binding-deficient mutant of Annexin A2, rendered cells to resist C-K treatment, indicating that C-K exerts its cytotoxic activity mainly by targeting Annexin A2. Conclusion: This study for the first time revealed a cellular target of C-K and the molecular mechanism for its anticancer activity.

• Nuclear Engineering and Technology
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• 제56권3호
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• pp.993-1001
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• 2024

The TANDEM project is a European initiative funded under the EURATOM program. The project started on September 2022 and has a duration of 36 months. TANDEM stands for Small Modular ReacTor for a European sAfe aNd Decarbonized Energy Mix. Small Modular Reactors (SMRs) can be hybridized with other energy sources, storage systems and energy conversion applications to provide electricity, heat and hydrogen. Hybrid energy systems have the potential to strongly contribute to the energy decarbonization targeting carbon-neutrality in Europe by 2050. However, the integration of nuclear reactors, particularly SMRs, in hybrid energy systems, is a new R&D topic to be investigated. In this context, the TANDEM project aims to develop assessments and tools to facilitate the safe and efficient integration of SMRs into low-carbon hybrid energy systems. An open-source "TANDEM" model library of hybrid system components will be developed in Modelica language which, by coupling, will extend the capabilities of existing tools implemented in the project. The project proposes to specifically address the safety issues of SMRs related to their integration into hybrid energy systems, involving specific interactions between SMRs and the rest of the hybrid systems; new initiating events may have to be considered in the safety approach. TANDEM will study two hybrid systems covering the main trends of the European energy policy and market evolution at 2035's horizon: a district heating network and power supply in a large urban area, and an energy hub serving energy conversion systems, including hydrogen production; the energy hub is inspired from a harbor-like infrastructure. TANDEM will provide assessments on SMR safety, hybrid system operationality and techno-economics. Societal considerations will also be encased by analyzing European citizen engagement in SMR technology safety.

• Clinical and Experimental Pediatrics
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• 제52권4호
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• pp.441-445
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• 2009

목 적 : 아미노필린을 낮은 농도(5 mg/kg/day)에서부터 점진적으로 증량할 때와 일상 용량(10 mg/kg/day)으로 시작할 때 나타나는 부작용을 비교하고자 하였다. 방 법 : 2007년 3월부터 2008년 1월까지 인하대병원 소아과에 호흡기질환으로 입원한 환아들을 대상으로 정주 아미노필린의 투여 용량을 달리하여, 투여 후 3일간의 활력 징후, 부작용 및 혈중 농도를 조사하였다. 결 과 : 저용량군 37명, 일반용량군 21명, 대조군 9명이었다. 저용량군과 보통용량군 간의 입원 시 연령, 신체활력징후, 혈액검사의 차이는 없었다. 경련과 같은 심각한 부작용은 없었다. 저용량군에서는 9명(24.3%)이 보챔, 수면장애로 아미노필린 사용을 중단하였으며, 일반용량군에서는 6명(28.6%)이 아미노필린 투여를 중단하였고, 투여를 중단한 경우의 혈중 농도($(3.68{\pm}1.93{\mu}g$/mL)와 중단 없이 사용한 군의 혈중농도($(4.47{\pm}2.45{\mu}g$/mL)의 차이는 없었다. 투여를 중단하게 된 경우는 대부분 2세 미만의 환자에서 발생하였다. 결 론 : 저자들은 급성 천식환자에서 정주 아미노필린의 부작용은 초기 투여용량과는 관계가 없다고 생각하며, 본 연구에서 사용한 용량보다 고용량 투약에 따른 연구 및 연령에 따른 연구가 필요할 것으로 생각한다.

• Toxicological Research
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• 제22권3호
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• pp.283-291
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• 2006

The survival and growth of epithelial cells depends on adhesion to the extracellular matrix. An adhesion signal may regulate the initiation of differentiation, since epidermal keratinocytes differentiate as they leave the basement membrane. A metabolically dead cornified cell envelope is the end point of epidermal differentiation so that this process may be viewed as a specialized form of programmed cell death. In order to investigate the precise cellular signaling events loading to terminal differentiation of keratinocytes, we have utilized HaCaT cells to monitor the biological consequences of $Ca^{2+}$ stimulation and numerous downstream signaling pathways, including activation of the extracellular signal-regulated protein kinase(ERK) pathway and activation of phosphatidylinositol 3-kinase(PI3K). The results presented in this study show that $Ca^{2+}$ function as potent agents for the differentiation of HaCaT keratinocytes, and this differentiation depends or the activation of ERK, Protein kinase B(PKB) and p70 ribosomal protein S6 kinase(p70S6K). Finally, the results show that the expression of Activator protein 1(AP-1; c-Jun and c-Fos) increased following $Ca^{2+}$-mediated differentiation of HaCaT cells, suggesting that ERK-mediated AP-1 expression is critical for initiating the terminal differentiation of keratinocytes.

• 한국임상약학회지
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• 제19권1호
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• pp.18-22
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• 2009

Oxaliplatin is a tolerable and effective drug of choice in the treatment of advanced or metastatic gastric cancer. However, it has many dose-limiting neurotoxicities. This study was performed to assess the incidence and types of oxaliplatin-related neurotoxicities. Sixty-four patients receiving oxaliplatin-involved regimen as salvage therapy on metastatic gastric cancer or as the first-line therapy on advanced gastric cancer were evaluated during the period between September 1, 2006 and February 29, 2008. The patients were treated with oxaliplatin 100 $mg/m^2$ and leucovorin 100 $mg/m^2$ simultaneously as 2-hour-lasting infusion on Day-1 followed by 5-FU 1200 $mg/m^2$ as a 22-hour-lasting continuous infusion both on Day-1 and Day-2 by every other week. We developed questionnaires to evaluate patient-recognized neurotoxic symptoms rather than the observer-described events. Surveys were completed at bedside or via telephone interview. Acute and chronic neurotoxicities were graded according to the National Cancer Institute Common Toxicity Criteria (NCI-CTC, version 3) as well as the Oxaliplatin-specific Neurotoxicity Scale. The Grade-3 neuropathy was reported in 19% of the patients (n=12) and grade-1/2 neuropathy occurred in 70% (n=45). The most common symptom was cold-related dysesthesia (83%) regarded as nociperception by the patients. Some patients (19%) experienced functional impairment affecting activities of daily living such as writing, buttoning, and walking. Even though 74% of the patients (42/57) were prescribed with gabapentin to reduce these peripheral symptoms, it did not appear to derive any benefit from this medication. It is suggested that notify the patients about their oxaliplatin-associated, debilitating symptoms, and educate them any self-care strategy at the initiating phase of the chemotherapy. Moreover, it needs to design the intervention studies regarding the prevention and management of the peripheral neuropathy.

• 대한한방내과학회지
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• 제27권3호
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• pp.639-652
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• 2006

Objective : The etiology of chronic prostatitis is likely multifactorial, resulting from either a cascade of events after an initiating factor or from a variety of etiologic mechanisms. There is substantiating evidence to support the role of the inflammatory responses in its pathogenesis, and the clinical value in the evaluation of therapeutic efficacy. Forsythiae Frucus has been traditionally used in treatment of inflammatory diseases, including of prostatitis and urinary tract inflammation. In this study, we investigated the effects of Forsythiae Frucus on inflammatory cytokines and cyto-pathological alternation in the rat model of chronic non-bacterial prostatitis induced by castration and $17{\beta}$-estradiol treatment. Methods : Two-month-old rats were treated with $17{\beta}$-estradiol after castration for induction of experimental non-bacterial prostatitis. which is similar to human chronic prostatitis in histopathological profiles. Forsythiae Frucus as an experimental specimen, and testosterone as a positive control, were administered orally. The prostates were evaluated by histopathologlcal parameters including the epithelial score and epithelio-stromal ratio for glandular damage. and the expression of inflammatory cytokine genes including interleukin (IL)-$1{\beta}$, IL-5, IL-12, tumor necrosis factor (TNF)-$\alpha$. eotaxin, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2(cox-2). Results : While prostates of control rats revealed severe acinar gland atrophy and stromal proliferation. the rats treated with Forsythiae Frucus showed a diminished range of tissue damage. Epithelial score was improved in the Forsythiae Frucus group over that of the control (P<0.05). The epithelia-stromal ratio was lower in the Forsythiae Frucus group when compared to that of the control (P<0.05). In the reverse transcription-polymerase chain reaction (RT-PCR) of inflammatory cytosine genes. Forsythiae Frucus inhibited the expression of IL-$1{\beta}$, TNF-$\alpha$, iNOS, cox-2 genes, while it modulated the expression of IL-5, which is an anti-inflammatory cytokine. Conclusions : These findings suggest that Forsythiae Frucus may protect the glandular epithelial cells and also inhibit stromal proliferation in association with the immune modulation including the suppression of inflammatory cytokines and increase of anti-inflammatory cytokines. From theses results. we suggest that Forsythiae Frucus could be a useful remedy agents for treating chronic non-bacterial prostatitis.

• Clinical and Experimental Pediatrics
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• 제49권9호
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• pp.966-971
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• 2006

목 적 : 성인의 심혈관질환은 태아발달 동안이나 이른 어린이 시기부터 시작된다는 태아프로그래밍 개념과 출생시 작게 태어난 경우에 성인기에 혈압이 상승된다는 연구들을 고려하여 볼 때, 출생시기부터의 혈압 변화에 대한 연구가 필요함을 느꼈다. 본 연구에서는 신생아의 여러 자궁내 발육 지표와 신생아의 혈압 관련성에 대해 살펴보고자 하였다. 방 법 : 이화여자대학교 목동병원에 내원한 임산부 중 연구참여에 동의한 산모를 대상으로 코호트를 구축하고 이들의 127명의 출생아에 대한 의무기록에 근거하여 자료를 추적, 수집하였고, 생후 24시간 이내에 신생아의 혈압을 측정하였다. 결 과 : 신생아 수축기 혈압과 태내 성장지표는 유의한 양의 상관관계를 보였다; 출생체중(r=0.4), 머리둘레(r=0.4), 출생신장(r=0.3). 그러나 체중대비 머리둘레 비는 신생아 혈압과 유의한 음의 상관관계를 보였다(r=-0.4). 아기의 성과 엄마의 혈압수준, 재태연령을 보정한 상태에서도 신생아 수축기 혈압은 태내 성장지표와 연관성을 보였다. 수축기 혈압은 출생체중이 가장 높은 군에서(90 백분위수 이상) 낮은 군과 비교하여(10 백분위수 미만) 7 mmHg 높았다, 한편 출생체중 대비 머리둘레의 비가 가장 높은 군(90 백분위수 이상)에서 낮은 군(10 백분위수 미만)에 비해 17 mmHg 낮게 나타났다. 결 론 : 우리 연구 결과 자궁내 성장 지연이 신생아의 혈압을 높이는데 영향을 미치는 것을 관찰할 수 없었다. 혈압 프로그래밍은 출생 이후에 성장기간에 시작되는 것으로 생각된다. 자궁내 성장지연으로 인해 혈압이 상승하는 주요 시작 지점이 언제인지 알아보기 위해서 출생 이후부터 따라잡기 성장과 함께 아동기시기 혈압 변화에 대한 지속적인 연구가 필요하다.