• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1191-1205
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• 2022

Particulate matter(PM) among air pollutants with complex and widespread causes is classified according to particle size. Among them, PM_2.5 is very small in size and can cause diseases in the human respiratory tract or cardiovascular system if inhaled by humans. In order to prepare for these risks, state-centered management and preventable monitoring and forecasting are important. This study tried to predict PM_2.5 in Seoul, where high concentrations of fine dust occur frequently, using two ensemble models, random forest (RF) and extreme gradient boosting (XGB) using 15 local data assimilation and prediction system (LDAPS) weather-related factors, aerosol optical depth (AOD) and 4 chemical factors as independent variables. Performance evaluation and factor importance evaluation of the two models used for prediction were performed, and seasonal model analysis was also performed. As a result of prediction accuracy, RF showed high prediction accuracy of R² = 0.85 and XGB R² = 0.91, and it was confirmed that XGB was a more suitable model for PM_2.5 prediction than RF. As a result of the seasonal model analysis, it can be said that the prediction performance was good compared to the observed values with high concentrations in spring. In this study, PM_2.5 of Seoul was predicted using various factors, and an ensemble-based PM_2.5 prediction model showing good performance was constructed.

• Journal of Conservation Science
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• v.38 no.2
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• pp.80-86
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• 2022

Termites cause massive damage to wooden architectural heritage structures. Chemical treatments have been commonly used to control them. In foreign countries, physical barriers made of sheet and particles impenetrable to termite are being used as an alternative to the chemical method. To study the efficacy of physical barriers, we investigated the appropriate sand particle size that can prevent the penetration of R. speratus kyushuensis. Upon evaluating the barrier properties of sand with particle sizes ranging from 0.85 to 4.00 mm, the penetration of termites was found to be effectively blocked at a particle size range of 1.00 to 2.80 mm. At smaller particle sizes, termites managed to move the sand particles and build an almost linear mud tube to penetrate the sand layer. At larger particle sizes, the termites could penetrate the sand layer by passing through the sand gaps.

• Journal of the Korean Society of Radiology
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• v.16 no.7
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• pp.961-968
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• 2022

Rotator cuff tears are a leading cause of shoulder pain in adults. Due to the increase in social activities, the number of patients complaining of shoulder pain is increasing, and interest in shoulder diseases is also increasing. With the development of ultrasound equipment, the sensitivity and specificity of diagnosis are high, and it is used to diagnose rotator cuff tears in musculoskeletal disease. Ultrasound is recognized as a complementary method to MRI examination in rotator cuff tears. Therefore, this study aimed to find out the diagnostic usefulness of ultrasound and MRI examinations in the diagnosis of shoulder rotator cuff tears.A retrospective analysis was performed on 262 patients who were diagnosed with final rotator cuff damage by arthroscopy after completing ultrasound and MRI examinations. Sensitivity, feature, positive predictive value, image predictive value, and touch were disassembled for the test results. In addition, the degree of clavicular tear was scored and recorded in 5 stages. Ultrasound examination was similar to MRI examination results for both full-thickness and partial tears, and there was no statistically significant difference. Partial tear test results showed higher positive predictive value and accuracy than MRI test. In conclusion, ultrasound can be fully utilized as a screening test for rotator cuff disease, and it is thought that it will be selected and used clinically according to the patient's constitution and situation.

• Journal of Life Science
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• v.32 no.6
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• pp.482-490
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• 2022

Sarcopenia, a geriatric and multifactorial syndrome characterized by progressive systemic skeletal muscle disorder, may be associated with many comorbidities. Sarcopenia caused by a decrease in muscle mass and muscle strength is accompanied by the aggravation of various pathological conditions, and as life expectancy increases, its prevalence will continue to increase in the future. During the aging process, chronic oxidative stress and increased inflammatory responses act as major contributors to skeletal muscle loss. In addition, disruption of autophagy and apoptosis signals associated with dysfunction of mitochondria, which are essential for energy metabolism, accelerates the loss of muscle proteins. The pharmacological effect of cordycepin, a major physiologically active substance in the genus Cordyceps, which has been widely used for the prevention and treatment of various diseases for a long time, is directly related to its antioxidant and anti-inflammatory actions. In this review, we present the correlation between apoptosis, autophagy, protein catabolism, and satellite cell activity important for muscle regeneration using cordycepin for the prevention and treatment of sarcopenia. Although there have been few studies so far on the use of cordycepin for sarcopenia, previous studies suggest that cordycepin may contribute to inhibiting the age-related weakening of mitochondrial function and blocking the breakdown of muscle proteins. In addition, the protective effect of cordycepin on muscle cell damage is considered to be closely related to its antioxidant and anti-inflammatory activities. Therefore, it is considered that more continuous basic research is needed, focusing on the molecular biological mechanism of cordycepin, which is involved in the anti-aging of muscle cells.

• Journal of Applied Biological Chemistry
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• v.65 no.4
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• pp.313-319
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• 2022

Consumption of high fat diet (HFD) induces obesity by accumulating triglycerides and inflammation in the body. In the present study, we investigated the effects of black onion vinegar (BV) on HFD-induced C57BL/6 obese mice model. The HFD-fed obese mice were administered black onion juice (BJ) and BV, respectively, for 6 weeks. The HFD-fed group increased body and organ weights compared with normal control diet-induced group. However, administration of BV significantly reduced body and organ weights compared with HFD-fed group. The BJ- and BV-administered groups improved the serum lipid profiles such as total cholesterol and triglyceride, compared with HFD-fed group. In addition, BV-administered group significantly improved serum high-density lipoprotein cholesterol and low-density lipoprotein cholesterol. The BV-administered mice had increased the number and size of adipose cells in the liver and adipose tissues. The administrations of BJ and BV significantly down-regulated adipogenesis transcription factors and proinflammatory proteins in the liver compared with HFD-fed group. In particular, BV-administered group showed stronger attenuation of adipogenesis-related proteins than the BJ-administered group. Therefore, this study demonstrated that administration of BV attenuated HFD-induced obesity, in particular down-regulation of adipogenesis, and it could be developed as a functional vinegar for anti-obesity.

• Korean Journal of Environmental Biology
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• v.39 no.4
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• pp.452-462
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• 2021

Pretilachlor (PRE) is a common acetanilide herbicide used worldwide. However, its effects on aquatic organisms, particularly marine photosynthetic life, are not sufficiently known. Herein, we evaluated the toxic effects of PRE by physiological and molecular parameters in the photosynthetic dinoflagellate Prorocentrum minimum. The cell density, pigment content, and photosynthetic parameters (F_v/F_m and PI_ABS) were considerably decreased with increased PRE exposure time and doses. In addition, photosynthesis-related genes, PmpsbA, PmpsaA, and PmatpB, were significantly upregulated when exposed to 1.0 mg L^-1 of PRE for 24 h (p<0.001). In 72 h treatment, the relative gene expression was significantly increased (0.1 and 0.5 mg L^-1; p<0.01). In contrast, PmrbcL was decreased or little changed compared to the controls. Reactive oxygen species (ROS) increased after 24 h exposure (p<0.001). However, the transcriptional fold-changes in glutathione S-transferase (GST) were significantly increased (0.5 and 1.0 mg L^-1; p<0.001) at 72 h. These findings suggested that the PmGST might be involved in PRE detoxification in P. minimum. In addition, PRE may affect the photosystem function in phytoplankton similar to other acetanilides, causing severe damage or cell death.

• Journal of Applied Biological Chemistry
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• v.65 no.1
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• pp.57-62
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• 2022

Excessive activation and aggregation of platelets is a major cause of cardiovascular disease. Therefore, inhibition of platelet activation and aggregation is considered an attractive therapeutic target in preventing and treating cardiovascular diseases. In particular, strong platelet activation and aggregation by collagen secreted from the vascular endothelium are characteristic of vascular diseases. Artesunate is a compound extracted from the plant roots of Artemisia or Scopolia species, and has been reported to be effective in anticancer and Alzheimer's disease fields. However, the effect and mechanism of artesunate on collagen-induced platelet activation and aggregation have not been elucidated. In this study, the effect of artesunate on collagen-induced human platelet aggregation was confirmed and the mechanism of action of artesunate was clarified. Artesunate inhibited the phosphorylation of PI3K/Akt and Mitogen-activated protein kinases, which are phosphoproteins that are known to act in the signal transduction process when platelets are activated. In addition, artesunate decreased TXA₂ production and decreased granule secretion in platelets such as ATP and serotonin release. As a result, artesunate strongly inhibited platelet aggregation induced by collagen, a strong aggregation inducer secreted from vascular endothelial cells, with an IC₅₀ of 106.41 µM. These results suggest that artesunate has value as an effective antithrombotic agent for inhibiting the activation and aggregation of human platelets through vascular injury.

• Journal of the Korean Institute of Gas
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• v.27 no.2
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• pp.7-15
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• 2023

The electric submersible pump (ESP) has been operating in production wells around the world because of its high applicability and operational efficiency among artificial lift techniques. When operating an ESP in a reservoir, variables such as temperature, pressure, gas/oil ratio, and flow rate are factors that affect ESP performance. In particular, free gas in the production fluid is a major factor that reduces the life and operational efficiency of ESP. This study presents the flow loop system which can implement the performance and damage tests of ESP considering field operating conditions to quantitatively analyze the variables that affect ESP performance. The developed apparatus in an integrated system that can diagnose the failure and causes of ESP, and detect leak of tubing by linking ESP and tubing as one system. In this study, the flow conditions for stable operation of ESP were identified through single phase and two phase flow experiments related to evaluation for the performance of ESP. The results provide the basic data to develop the failure prediction and diagnosis program of ESP, and are expected to be used for real-time monitoring for optimal operating conditions and failure diagnosis for ESP operation.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.327-327
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• 2021

하수재이용에서 전처리 막여과 공정은 완벽한 고액분리로 인해 후단 역삼투막 손상을 줄일 수 있는 공정으로 각광을 받고 있다. 일반적으로 막여과 공정은 여과->물리세정->충진->여과 와 같은 제막사에서 제공하는 운전 사이클에 맞춰 적용하고 있으며 유지세정 역시 1회/일 또는 1회/주 단위로 정해진 범위에서 수행되고 있다. 이러한 운전 방식은 시시각각 변화하는 막 유입수질에 적절하게 대응하지 못해 장기적으로 막오염 발생에 따른 생산수량 감소는 물론 막오염 제거를 위한 화학세정 주기가 짧아져 전체적인 생산수량이 감소하는 원인이 되고 있다. Raffine(2012)에 따르면 가역적 막오염의 경우 Flux 증가에 큰 영향이 없으나 비가역적 막오염은 Flux 증가에 따라 급격히 증가한다고 보고하고 있으며 이는 제한된 분리막 면적당 처리수 생산량을 증가시키기 위해 비가역적 막오염의 발생량을 줄이는 것이 필요하며 이를 위해 주기적인 강화역세(Chemical Enhanced Backwashing, CEB)가 도입되고 효율적인 유지세정 방법에 대한 연구가 진행되고 있다. 당사에서는 일산에 있는 I 수질복원센터내에 25 m³/일 규모의 막여과 하수재이용 파일롯 플랜트를 설치하고 막여과 하수재이용 공정의 운영 효율을 높이기 위하여 W사에서 개발한 IntelliFluxControl(IFCr) 소프트웨어를 이용하여 하수재이용 막여과 성능을 확인 하였다. IFCr은 실시간으로 변화하는 수질에 따른 막오염 정도에 따라 역세 강도 및 빈도와 CEB 적용 정도를 변화시켜 분리막 운전의 효율을 높일 수 있는 운영 소프트웨어이다. I 수질복원센터의 하수 방류수를 막여과 유입수로 적용하여 40 LMH를 기준으로 IFCr을 적용하지 않은 경우 23.7일 운전 가능하였으나 IFCr을 적용한 경우 50일 연속 운전이 가능하였다. 또한 역세척수를 운전 기간 동안 약 50 m³을 사용한 반면 IFCr을 적용한 경우 이에 절반 수준인 24.1 m³ 만 사용하여 회수율이 91%에서 95%로 증가한 것을 확인 할 수 있었다. 본 연구의 결과는 기존의 제막사에서 제시하는 막 공정 운영방법을 탈피하여 분리막이 갖고 있는 성능을 최대한 끌어 올릴 수 있는 연구 결과라고 판단되며 향후 스케일 업 연구를 통해 실제 플랜트에 적용 가능성이 확인 될 경우 시설의 설치 막모듈 개수와 유지관리비를 동시에 절감할 수 있는 기술이 될 수 있을 것이다

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.83-83
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• 2020

염증은 물리화학적 자극이나 세균 감염과 같은 외부 자극에 대응하기 위한 생체조직의 방어 반응의 하 나이며 조직이나 장기의 손상을 회복시키는 기전으로서 매우 중요한 역할을 하지만 염증반응이 과도해 질 경우 궤양성 대장염, 기관지염, 천식, 대장암 등을 유발하는 원인으로 작용하기 때문에 염증반응을 조 절하는 항염증제 개발은 매우 중요시되고 있다. 국내 염증개선 관련 시장은 현재 약 3조원 규모이며 지속 적인 성장세에 있지만 천연소재의 기능성 중심으로 출시된 제품 중 다수의 제품에서 주로 수입 원료를 사용하고 있어 국내 자생 및 재배하는 천연 소재들의 효능에 대한 검증을 통해 수입 원료 의존도를 낮추 기 위한 연구가 요구되고 있다. 따라서 본 연구에서는 순창에서 재배되는 참두릅 (Aralia elata Seem)과 도라지 (Platycodon grandiflorum)를 이용하여 천연 염증개선 소재화를 목적으로 기능성 증진을 위한 추 출조건 선정과정과 대식세포에 대한 세포독성 및 항염증 효능을 확인하여 천연소재를 이용한 염증개선 소재화를 시도하고자 한다. 본 연구는 전북 순창에서 재배되는 참두릅과 도라지의 추출조건을 선정하기 위해 용매, 온도 및 시간별 추출물의 total polyphenol 함량 평가를 통하여 최적 추출조건 선정을 진행하 였으며, 선정된 추출조건에서 추출된 추출물의 항산화 활성을 측정하기 위하여 DPPH & ABTS radical scavenging activity 및 total flavonoids 함량을 확인하여 항산화 효능을 평가하였다. 또한 대식세포인 Raw 264.7을 사용하여 MTT assay, Nitric oxide (NO) 생성 억제 효능을 확인하여 세포독성 및 항염증 활 성을 평가하였다. 실험결과, Total polyphenol 함량 분석을 통해 최적 추출조건이 선정된 두릅 (주정 40%, 25℃, 3 h), 도라지 (주정 60%, 25℃, 1 h)의 추출물을 이용하여 DPPH & ABTS radical scavenging activity 및 total flavonoids 함량을 분석한 결과, 도라지보다 두릅에서 더 높은 항산화 활성을 나타내었다. 대식세포를 활용한 두릅과 도라지의 세포독성을 측정한 결과, 100 ug/mL 이내의 농도에서 독성활성이 나타내지 않음을 확인되었으며, 항염증 활성을 측정한 결과 100 ug/mL에서 두릅 추출물이 도라지 추출 물보다 약 33% 이상 NO 생성억제 활성이 높게 나타내었다.