• Nuclear Engineering and Technology
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• 제51권6호
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• pp.1540-1553
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• 2019

A nuclear power plant (NPP) is a highly complex system-of-systems as manifested through its internal systems interdependence. The negative impact of such interdependence was demonstrated through the 2011 Fukushima Daiichi nuclear disaster. As such, there is a critical need for new strategies to overcome the limitations of current risk assessment techniques (e.g. the use of static event and fault tree schemes), particularly through simulation of the nonlinear dynamic feedback mechanisms between the different NPP systems/components. As the first and key step towards developing an integrated NPP dynamic probabilistic risk assessment platform that can account for such feedback mechanisms, the current study adopts a system dynamics simulation approach to model the thermal dynamic processes in: the reactor core; the secondary coolant system; and the pressurized water reactor. The reactor core and secondary coolant system parameters used to develop system dynamics models are based on those of the Palo Verde Nuclear Generating Station. These three system dynamics models are subsequently validated, using results from published work, under different system perturbations including the change in reactivity, the steam valve coefficient, the primary coolant flow, and others. Moving forward, the developed system dynamics models can be integrated with other interacting processes within a NPP to form the basis of a dynamic system-level (systemic) risk assessment tool.

• Journal of Korean Neurosurgical Society
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• 제66권5호
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• pp.503-510
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• 2023

Objective : The present study aimed to determine the topical and systemic efficacy of tranexamic acid (TXA) on epidural fibrosis in a rat laminectomy model. Methods : Thirty-two 12-month-old adult Sprague-Dawley rats were used in this study. Each rat underwent bilateral laminectomy at the L1 and L2 vertebral levels. Rats were divided into four groups : in group I (control group, n=8), a laminectomy was performed and saline solution was applied into the surgical space. In group II (topical group, n=8), laminectomy was performed and 30 mg/kg TXA was applied to the surgical site before skin closure. In group III (systemic group, n=8), 30 mg/kg TXA was administered intravenously via the tail vein in the same session as the surgical procedure. In group IV (topical and systemic group, n=8), TXA was administered 30 mg/kg both topical and intravenous. The rats were sacrificed at 4 weeks postoperatively. Masson's trichrome and hematoxylin and eosin were used to assess acute inflammatory cells, chronic inflammatory cells, vascular proliferation, and epidural fibrosis. Results : Epidural fibrosis, acute inflammation, chronic inflammation, and sum histologic score value were significantly lower in the systemic TXA group, systemic and topical TXA groups than in the control group (p<0.05). In addion, the sum histologic score was significantly lower in the topical TXA group than in the control group (p<0.05). Conclusion : In this study, epidural fibrosis formation was prevented more by systemic application, but the topical application was found to be effective when compared to the control group. As a result, we recommend the systemic and topical use of TXA to prevent epidural fibrosis during spinal surgery.

• Pediatric Infection and Vaccine
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• 제24권2호
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• pp.102-107
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• 2017

목적: 가와사키병의 환아뿐만 아니라, 다른 전신 염증 질병의 환아들에 관상동맥 병변(coronary arterial lesion [CAL])의 발생이 보고되었다. 본 연구에서는 전형적인 전신염증반응증후군(systemic inflammatory response syndrome [SIRS])의 소견을 보이는 패혈증 마우스 모델에서 가와사키병 환아에게 관찰되는 CAL이 발생하는지 확인하고자 하였다. 방법: 생후 6주 C57BL/6 마우스에 내독소를 복강내주사하여 SIRS를 보이는 패혈증 모델을 유도하였다. 대조군과 패혈증군의 주요 장기의 조직학적 소견을 비교하였고 패혈증 마우스에서 CAL을 찾기 위한 시도를 하였다. 결과: 대조군과 비교하여, 염증세포의 침윤이 패혈증 마우스의 심장, 간, 신장에 상대적으로 증가하였다. 패혈증 마우스의 심장에서 심근(심근염)과 심장 주위 연조직에 림프구 침윤을 확인하였다. 또한, 패혈증 마우스의 관상동맥을 관찰하였지만, CAL을 확인할 수는 없었다. 결론: 본 연구에서 패혈증 마우스 모델에서 CAL의 존재를 확인하는 것은 실패하였다. 하지만, SIRS를 유발하는 많은 종류의 원인 질병에서 CAL이 발생한다는 것은 잘 알려져 있다. 가와사키병을 포함한 다양한 전신 염증 질병에 나타나는 CAL의 임상적 의미에 대한 연구가 필요할 것이다.

• 영어어문교육
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• 제8권1호
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• pp.223-239
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• 2002

This paper aims to describe the theme of English clause in terms of systemic grammar. For this I analyze the three subaereas of subject theme and the four subareas of nonsubject theme in the form of features. Each of the seven feature sets of the seven thematic subareas is described in the systemic model. Finally All of the subsystems are described in the framework of the system network in order to show the potential of options of thematic English clause available in a certain situation.

• 대한간호학회지
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• 제31권2호
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• pp.328-339
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• 2001

The purpose of this study was to describe decision making model of 180 public health nurses in Korea and their knowledge structure for decision making. The differences of decision making models by nurse's knowledge structure were also tested. Research concepts were measured using the instrument based on systemic and interpretive decision making approaches that were developed by Lauri & Salantera (1995). The results were as follows. 1. The public health nurses turned to, most commonly, a mixed practical-theoretical knowledge structure (45.9%), followed by practical knowledge (32%) and theoretical knowledge (22.1%). 2. The six different decision making models were identified. These were named for decision making theories and nursing process. These were client-oriented decision making, rule-oriented systemic decision making, wholistic and intuitive decision making, decision making depending on subjective view and experience, systemic decision making for defining problems. 3. The public nurses who had practical and practical-theoretical knowledge structure and community health practitioner (CHP) retold that decision making depends on subjective view and experience. Also the public health nurses who had 5~19 years clinical experience represented hypothetico-deductive decision making for defining problems.

• Clinical and Experimental Pediatrics
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• 제64권1호
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• pp.37-43
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• 2021

Background: Animal studies have shown that a leukocyte influx precedes the development of bronchopulmonary dysplasia (BPD) in premature sheep. The CXC chemokine receptor 2 (CXCR2) pathway has been implicated in the pathogenesis of BPD because of the predominance of CXCR2 ligands in tracheal aspirates of preterm infants who later developed BPD. Purpose: To test the effect of CXCR2 antagonist on postnatal systemic and pulmonary inflammation and alveolarization in a newborn Sprague-Dawley rat model of BPD. Methods: Lipopolysaccharide (LPS) was injected intraperitoneally (i.p.) into the newborn rats on postnatal day 1 (P1), P3, and P5 to induce systemic inflammation and inhibit alveolarization. In the same time with LPS administration, CXCR2 antagonist (SB-265610) or vehicle was injected i.p. to investigate whether CXCR2 antagonist can alleviate the detrimental effect of LPS on alveolarization by attenuating inflammation. On P7 and P14, bronchoalveolar lavage fluid (BALF) and peripheral blood (PB) were collected from the pups. To assess alveolarization, mean cord length and alveolar surface area were measured on 4 random nonoverlapping fields per animal in 2 distal lung sections at ×100 magnification. Results: Early postnatal LPS administration significantly increased neutrophil counts in BALF and PB and inhibited alveolarization, which was indicated by a greater mean cord length and lesser alveolar surface area. CXCR2 antagonist significantly attenuated the increase of neutrophil counts in BALF and PB and restored alveolarization as indicated by a decreased mean cord length and increased alveolar surface area in rat pups exposed to early postnatal systemic LPS. Conclusion: CXCR2 antagonist preserved alveolarization by alleviating pulmonary and systemic inflammation induced by early postnatal systemic LPS administration. These results suggest that CXCR2 antagonist can be considered a potential therapeutic agent for BPD that results from disrupted alveolarization induced by inflammation.

• Journal of Korean Neurosurgical Society
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• 제67권2호
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• pp.177-185
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• 2024

Objective : Delayed cerebral ischemia (DCI) is a major cause of disability in patients who survive aneurysmal subarachnoid hemorrhage (aSAH). Systemic inflammatory markers, such as peripheral leukocyte count and systemic immune-inflammatory index (SII) score, have been considered predictors of DCI in previous studies. This study aims to investigate which systemic biomarkers are significant predictors of DCI. Methods : We conducted a retrospective, observational, single-center study of 170 patients with SAH admitted between May 2018 and March 2022. We analyzed the patients' clinical and laboratory parameters within 1 hour and 3-4 and 5-7 days after admission. The DCI and non-DCI groups were compared. Variables showing statistical significance in the univariate logistic analysis (p<0.05) were entered into a multivariate regression model. Results : Hunt-Hess grade "4-5" at admission, modified Fisher scale grade "3-4" at admission, hydrocephalus, intraventricular hemorrhage, and infection showed statistical significance (p<0.05) on a univariate logistic regression. Lymphocyte and monocyte count at admission, SII scores and C-reactive protein levels on days 3-4, and leukocyte and neutrophil counts on days 5-7 exhibited statistical significance on the univariate logistic regression. Multivariate logistic regression analysis revealed that monocyte count at admission (odds ratio [OR], 1.64; 95% confidence interval [CI], 1.04-2.65; p=0.036) and SII score at days 3-4 (OR, 1.55; 95% CI, 1.02-2.47; p=0.049) were independent predictors of DCI. Conclusion : Monocyte count at admission and SII score 3-4 days after rupture are independent predictors of clinical deterioration caused by DCI after aSAH. Peripheral monocytosis may be the primer for the innate immune reaction, and the SII score at days 3-4 can promptly represent the propagated systemic immune reaction toward DCI.

• Advances in Traditional Medicine
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• 제3권1호
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• pp.46-50
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• 2003

We studied the inhibitory effect of Green Life Enzyme (GLE) on compound 48/80-induced anaphylactic response in a murine model. GLE inhibited compound 48/80-induced systemic anaphylactic shock at the dose of 10 g/kg by 87.5%. When GLE was given as pre-treatment at concentrations ranging from 0.01 to 1.0 g/kg, it inhibited passive cutaneous anaphylaxis activated by anti-dinitrophenyl (DNP) IgE. In addition, GLE (0.1 mg/ml) inhibited anti-DNP IgE-induced tumor necrosis $factor-{\alpha}$ production from mast cells by 69% compared to saline value. These results indicate that GLE may possess anti-anaphylactic and anti-inflammatory activity.

• The Plant Pathology Journal
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• 제22권4호
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• pp.360-363
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• 2006

Efficacy of plant growth promoting rhizobacteria(PGPR) Bacillus vallismortis strain EXTN-1 has been proved in eliciting induced systemic resistance(ISR) in several crops. The present paper described the beneficial effects of EXTN-1 in potato as increase in yield and chlorophyll content, and plant protection against Potato Virus Y and X(PVY & PVX). EXTN-1 induced systemic resistance to the plants resulting in significant disease suppression in the field. Also the plants under treatment with EXTN-1 had higher chlorophyll content. The bacterized plants had significantly higher yields over the untreated control plants. The strain induced activation of defense genes, PR-1a and PDF 1.2 in transgenic tobacco model, which indicated the possible role of both SA, and JA pathways in EXTN-1 mediated plant protection against crop diseases.

• 한국병원경영학회지
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• 제25권1호
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• pp.32-45
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• 2020

Purpose: The purpose of this research is to develop two medical tourism system models which explain medical tourism phenomenon with a systemic approach. Methodology/Approach: This research was conducted using a qualitative data analysis which mainly refer previous references in relation to medical tourism in the areas of tourism and medicine. Leiper's tourism system model was utilized as a conceptual framework. In-depth interviews with experts in the area were attempted in order to pretest the models. Findings: This research suggests a medical tourism system framework and a medical service provision framework. The first model presents medical tourism components and their relationships within a framework presented in a diagram. The second model shows the relationships among medical services required by medical tourists, the service providers, and service human resources along with movements of medical tourists. Practical Implications: The first model presents a spatial composition of medical tourism components and their relationships, whereas the second model shows the linkage among medical services, the service providers, and relevant service human resources along with time sequential steps of medical tourists. These two models are complementary and may be used as useful tools to observe medical tourism phenomenon with a systemic and holistic approach. These two models may enable stake holders avoid unnecessary confusions and conflicts that result in duplication of government policies and a waste of budget and human resources.