• 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

• Journal of the Computational Structural Engineering Institute of Korea
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• v.37 no.3
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• pp.205-216
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• 2024

Recently, seismic Probabilistic Safety Assessment (PSA) methods have been developed for process plants, such as gas plants, oil refineries, and chemical plants. The framework originated from the PSA of nuclear power plants, which aims to assess the risk of reactor core damage. The original PSA method was modified to adopt the characteristics of a process plant whose purpose is continuous operation without shutdown. Therefore, a fault tree, whose top event is shut down, was constructed and transformed into a Bayesian Network (BN), a probabilistic graph model, for efficient risk-informed decision-making. In this research, the fault tree-based BN from the previous research is further developed to consider the multi-hazard of earthquake-induced fire and explosion (EQ-induced F&E). For this purpose, an event tree describing the occurrence of fire and explosion from a release is first constructed and transformed into a BN. And then, this BN is connected to the previous BN model developed for seismic PSA. A virtual plot plan of a gas plant is introduced as a basis for the construction of the specific EQ-induced F&E BN to test the proposed BN framework. The paper demonstrates the method through two examples of risk-informed decision-making. In particular, the second example verifies how the proposed method can establish a repair and retrofit strategy when a shutdown occurs in a process plant.

• Journal of the Korean Society of Radiology
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• v.83 no.3
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• pp.538-558
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• 2022

The perivascular space (PVS) of the brain, also known as Virchow-Robin space, consists of cerebrospinal fluid and connective tissues bordered by astrocyte endfeet. The PVS, in a word, is the route over the arterioles, capillaries, and venules where the substances can move. Although the PVS was identified and described first in the literature approximately over 150 years ago, its importance has been highlighted recently after the function of the waste clearing system of the interstitial fluid and wastes was revealed. The PVS is known to be a microscopic structure detected using T2-weighted brain MRI as dot-like hyperintensity lesions when enlarged. Although until recently regarded as normal with no clinical consequence and ignored in many circumstances, several studies have argued the association of an enlarged PVS with neurodegenerative or other diseases. Many questions and unknown facts about this structure still exist; we can only assume that the normal PVS functions are crucial in keeping the brain healthy. In this review, we covered the history, anatomy, pathophysiology, and MRI findings of the PVS; finally, we briefly touched upon the recent trials to better visualize the PVS by providing a glimpse of the brain fluid dynamics and clinical importance of the PVS.

• Korean Chemical Engineering Research
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• v.62 no.3
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• pp.274-280
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• 2024

Machine learning techniques utilizing neural networks have been employed in various fields such as disease gene discovery and diagnosis, drug development, and prediction of drug-induced liver injury. Disease features can be investigated by molecular information of DNA. In this study, we developed a neural network to predict the length of DNA and the number of DNA species in mixture solution which are representative molecular information of DNA. In order to address the time-consuming limitations of gel electrophoresis as conventional analysis, we analyzed the dynamic data of a microfluidic concentrating device. The dynamic data were reconstructed into a spatiotemporal map, which reduced the computational cost required for training and prediction. We employed a convolutional neural network to enhance the accuracy to analyze the spatiotemporal map. As a result, we successfully performed single DNA length prediction as single-variable regression, simultaneous prediction of multiple DNA lengths as multivariable regression, and prediction of the number of DNA species in mixture as binary classification. Additionally, based on the composition of training data, we proposed a solution to resolve the problem of prediction bias. By utilizing this study, it would be effectively performed that medical diagnosis using optical measurement such as liquid biopsy of cell-free DNA, cancer diagnosis, etc.

• Radiation Oncology Journal
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• v.10 no.1
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• pp.7-14
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• 1992

Between August 1988 and December 1991, 24 patients with intracranial tumors were treated with stereotactic radiosurgery(RS) using a 10 MV linear accelerator at Severance Hospital, Yonsei University College of Medicine. There were 5 meningiomas, 3 craniopharyngiomas, 9 glial tumors, 2 solitary metastases, 2 acoustic neurinomas, 2 pineal tumors, and 1 non-Hodgkin's lymphoma. Ten patients were treated as primary treatment after diagnosis with stereotactic biopsy or neuroimaging study. Nine patients underwent RS for post-op. residual tumors and three patients as a salvage treatment for recurrence after external irradiation. Two patients received RS as a boost followed by fractionated conventional radiotherapy. Among sixteen patients who were followed more than 6 months with neuroimage, seven patients (2 meningiomas, 4 benign glial tumors, one non-Hodgkin's lymphoma) showed complete response on neuroimage after RS and nine patients showed decreased tumor size. There was no acute treatment related side reaction. Late complications include three patients with symptomatic peritumoral brain edema and one craniopharyngioma with optic chiasmal injury. Through this early experience, we conclude that stereotactically directed single high doses of irradiation to the small intracranial tumors is effective for tumor control. However, in order to define the role of radiosurgery in the management of intracraniai tumors, we should get the long-term results available to demonstrate the benefits versus potential complications of this therapeutic modality.

• Journal of the Korean Arthroscopy Society
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• v.16 no.1
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• pp.1-8
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• 2012

Purpose: To evaluate clinical and radiologic outcomes of transphyseal anterior cruciate ligament (ACL) reconstruction in patients with open physes who were selected with authors' new operative indications. Materials and Methods: We evaluated 15 patients with open physes who underwent a transtibial ACL reconstruction and were followed up for 4~6 years after surgery. Our operative indications involved 1) choronologic age of ${\geq}$ 16 in male and ${\geq}$ 14 in female, 2) open physes of ${\leq}$ 2 mm width, and 3) Risser sign and Tanner stage of ${\geq}$ 3. Tibialis anterior tendon allograft was used in all patients, and endobutton and bioscrew were used for femoral and tibial fixations, respectively. Functional outcomes were evaluated using Lysholm Knee Scoring scale, Tegner activity scale, and International Knee Documentation Committee (IKDC) 2000 subjective score. Physical examinations to evaluate stability involved Lachman and pivot shift tests. For radiographic results, we evaluated side to side differences of anterior displacement in stress views. In addition, with use of scannograms taken at last follow-up, we examined side to side differences of femorotibial angles, anatomical and mechanical lateral distal femoral angles, mechanical medial proximal tibial angles and leg lengths. Results: The mean Lysholm Knee score was 51(40-61) points preoperatively and 97(94-100) points at last follow up. The mean Tegner activity score was 2.6 points preoperatively and 7.1 points at last follow up. The mean IKDC score was 32.6 points preoperatively and 88.3 points at last follow up. The mean anterior displacement of the tibia was improved from 6.7(${\pm}1.0$) mm to 1.9(${\pm}0.9$) mm. There were no leg length discrepancies over 5 mm and no statistically significant differences in all the radiographic variables representing growth disturbance. Conclusion: This study suggests that patients with open physes who selected by authors' new indication would safely undergo transphyseal ACL reconstruction with successful outcomes.

• Journal of Chest Surgery
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• v.36 no.5
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• pp.343-347
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• 2003

Background: The femoral artery is the most common site of canuulation for cardiopulmonary bypass in surgery for type A aortic dissection. Recently, many surgeons prefer the axillary artery to the femoral artery as the arterial cannulation site for several benefits. We evaluated the safety and usefulness of axillary artery cannulation in surgery for acute type A aortic dissection. Material and Method: Between Oct. 1995 and Sep. 2001, 71 patients underwent operations for acute type A aortic dissection. The arterial cannula was inserted into the axillary artery in 31 patients (AXILLARY group, mean age=56), and into the femoral artery in 40 patients (FEMORAL group, mean age=57). We retrospectively compared the incidence of mortality, morbidities, and hospital course. Result: The mean duration of cardiopulmonary bypass and circulatory arrest were significantly shorier in the AXILLARY group (207 min and 39min, respectively) than in the FEMORAL group (263min and 49 min, respectively; P<0.05). Postoperative hospital stay was significantly shorter in the AXILLARY group than in the FEMORAL group (mean 15 days vs. 35 days, p<0.05). Although there was no difference in the incidence of new-onset permanent neurological dysfunction (3.2%, in the AXILLARY group, 2.5% in the FEMORAL group), the incidence of transient neurological dysfunction was significantly lower in the AXILLARY group (12.9% vs. 25%, p<0.05). In the FEMORAL group, two patients needed urgent conversion to cannulation site due to arch vessel malperfusion. In the AXILLARY group, there was only one patient who had a complication related to the cannulation, i.e., median nerve injury. Conclusion: Axillary artery cannulation was safe and helpful in decreasing the cerebral ischemic time and incidence of transient neuroligcal dysfunction in surgery for acute type A aortic dissection, It enabled us to approach the patients with aortic arch pathology more aggressively.

• Tuberculosis and Respiratory Diseases
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• v.63 no.6
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• pp.497-506
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• 2007

Background: The present investigation was performed in rats and isolated human neutrophils in order to confirm the presumptive role of the positive feedback loop of cytosolic phospholipase $A_2$ ($cPLA_2$) activation by plateletactivating factor (PAF). Methods: The possible formation of the positive feedback loop of the $cPLA_2$ activation and neutrophilic respiratory burst was investigated in vivo and in vitro by measurement of the parameters denoting acute lung injury. In addition, morphological examinations and electron microscopic cytochemistry were performed for the detection of free radicals in the lung. Results: Five hours after intratracheal instillation of PAF ($5{\mu}g/rat$), the lung leak index, lung myeloperoxidase (MPO) activity, the number of neutrophils and the concentration of cytokine-induced neutrophil chemoattractant (CINC) in bronchoalveolar lavage fluid were increased by PAF as compared with those of control rats. The NBT assay and cytochrome-c reduction assay revealed an increased neutrophilic respiratory burst in isolated human neutrophils following exposure to PAF. Lung and neutrophilic $cPLA_2$ activity were increased following PAF exposure and exposure to hydrogen peroxide increased $cPLA_2$ activity in the lung. Histologically, inflammatory findings of the lung were observed after PAF treatment. Remarkably, as determined by $CeCl_3$ cytochemical electron microscopy, increased production of hydrogen peroxide was identified in the lung after PAF treatment. Conclusion: PAF mediates acute oxidative lung injury by the activation of $cPLA_2$, which may provoke the generation of free radicals in neutrophils.

• Journal of Haehwa Medicine
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• v.4 no.2
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• pp.255-272
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• 1996

소적백출산(消積白朮散)은 ${\ll}$화제국방(和劑局方)${\gg}$에 삼령백출산(蔘笭白朮散)에 정열해독약(淸熱解毒藥)인 와송(瓦松) 금은화(金銀花) 포공영(蒲公英)을 가미(加味)한 처방(處方)으로, 본방(本方)인 삼령백출산(蔘笭白朮散)은 비위허약(脾胃虛弱), 음식부진(飮食不振), 다곤소력(多困少力) 중만비대(中滿痺臺), 심정기천(心柾氣喘), 구토(嘔吐), 설사(泄瀉), 상한해수(傷寒咳嗽)를 치료목적(治療目的)으로 쓰여 온 이래(以來) 임상에서는 대편부실(大便不實), 구설(久泄), 옹달궤후(癰疸潰後) 불사식자(不思食者)를 치료(治療)하는데 다용(多用)되어 왔다. 종양(腫瘍)(Neoplasia)은 새로운 성장(成長)(New+ Glowth) 이라는 세포학적(細胞學的)으로 비정상세포(非正常細胞)의 과다증식(過多增殖)으로 인해 실질장기(實質臟器), 유강장기(有腔腸器), 및 골격(骨格), 피부조직(皮膚組織)에 비정상조직(非正常組織)을 형성(形成)하는 질환(疾患)이다. 현대적(現代的) 종양(腫瘍)과 유사(類似)한 한의학적(韓醫學的)인 병증(病症)은 ${\ll}$소문(素問)${\gg}$에서는 "궐산(厥疝), 복량(伏梁), 식적(息積)"으로 ${\ll}$영추(靈樞)${\gg}$에서는 "장담(腸覃), 석가"로 표시(表示)된 이후(以後)로 소원방(巢元方)은 징가, 식일, 석옹(石癰), 완저(緩疽), 석저(石疽) 등으로 표현(表現)하였다. 원인(原因)에 대(對)해서는 ${\ll}$내경(內經)${\gg}$에서는 허(虛)와 한기(寒氣), 한(寒) 열(熱)로 보았고, 그 외(外)의 학자(學者)들은 내허(內虛)와 기혈불순(氣血不順), 화(火), 한(寒), 기울(氣鬱), 음양불화(陰陽不和)등으로 보았다. 치료(治療)는 ${\ll}$내경(內經) 자법론(刺法論)${\gg}$에서 "정기재내(正氣在內) 사불가우(邪不可于)" 이라 하여 생명활동(生命活動)의 원동력(原動力)인 정기(正氣)의 역할(役割)을 강조(强調)하였고, ${\ll}$육원정기대론(六元正氣大論)${\gg}$에서는 "대적대취(大積大聚) 불가범야(不可犯也) 쇠기태반이지(衰其太半而止)"라 하여 공벌약(攻伐藥)을 과용(過用)하여 정기(正氣)를 손상(損傷)시켜서는 안된다고 하는 등 부정위주(扶正爲主), 거사위주(祛邪爲主) 혹은 부정거사(扶正祛邪) 겸용(兼用)의 방법(方法)이 혼용(混用)되고 있다. 현대(現代) 서양의학(西洋醫學)의 항암제(抗癌劑)는 치료효과(治療效果)는 우수(優秀)하지만 악심(惡心), 구토(嘔吐)를 비롯하여 골수억제효과(骨髓抑制效果)와 간(肝), 심(心), 신(腎), 폐(肺)의 손상(損傷)을 초래(招來)하는 등(等)의 부작용(副作用)을 나타내며, 빈번(頻繁)한 화학요법제(化學療法劑)의 투여(投與)로 인(因)한 암세포(癌細胞)의 약제저항성(藥劑抵抗性) 출현(出現)등이 항암제(抗癌劑)의 문제점(問題點)으로 제시(提示)되고 있다. 이에 저자(著者)는 비위기능(脾胃機能)을 강화(强化)시켜 정기형성(正氣形成)에 깊이 관여(關與)하는 삼령백출산(蔘笭白朮散)에 청열해독(淸熱解毒), 소종산결지제(消腫散結之劑)인 금은화(金銀花), 포공영(浦公英), 와송(瓦松)을 가미(加味)하여 암발생(癌發生) 백서(白鼠)에 투약(投藥)한 후(後) sarcoma 180암세포(癌細胞)에 대(對)한 생명연장효과(生命延長效果)와 항암제(劑)의 일종(一種)인 cis-platin을 이용(利用)하여 양방항암제(洋方抗癌劑)의 부작용(副作用)에 대(對)한 본(本) 방(方)의 효과(效果)를 실험(實驗)하여 관찰(觀察)하였던 바 다음과 같은 결론(結論)을 얻었다. 1. 소적백출산(消積白朮散)은 sarcoma 180 암세포(癌細胞) 이식종양(移植腫瘍)에 대(對)해 생명연장효과(生命延長效果)가 인정(認定)되었다. 2. 소적백출산(消積白朮散)은 치암제(治癌劑)인 cis-platin 치사독성(致死毒性)에 대(對)해 생존연장효과(生存延長效果)가 인정(認定)되었다. 3. 소적백출산(消積白朮散)은 cis-platin 현독성(腎毒性) 생쥐 및 흰쥐에 있어서 유의성(有意性) 있는 체중감소억제효과(體重減少抑制效果) 및 serum BUN 상승억제효과(上昇抑制效果)가 인정(認定)되었다. 4. 소적백출산(消積白朮散)은 cis-platin 현독성(賢毒性) 흰쥐에 대(對)해 유의성(有意性) 있는 serum creatinine 상승억제효과(上昇抑制效果)가 나타났으며, cis-platin의 혈액학적(血液學的) 부작용(副作用)인 RBC, WBC 감소(減少)에 대(對)해 감소억제효과(減少抑制效果)가 인정(認定)되었다. 5. 소적백출산(消積白朮散)은 cis-platin 현독성(腎毒性) 흰쥐에 대(對)해 뇨량감소억제(尿量減少抑制) 효과(效果) 및 ureanitrogen과 creatinine 배수감소억제효과가 관찰(觀察)되었다. 이상(以上)의 결과(結果)로부터 소적백출산(消積白朮散)은 악성종양치료(惡性腫瘍治療) 및 항암제(劑)의 부작용(副作用)을 경감(輕減)시키는 데 응용(應用)할 수 있을 것으로 사료(思料)된다.

• Korean Journal of Microbiology
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• v.38 no.3
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• pp.153-161
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• 2002

Sox4, a transcription factor, consists of three functional domains: an HMG-box domain as a DNA binding domain, serine rich region as a transactivation domain and glycine rich region (GRR), an unknown functional domain. Although Sox4 is known to be functionally involved in heart, B-cell and reproductive system development, its physiological function remains to be elucidated. We used pGEX expression system to develop a simple and rapid method for purifying Sox4 protein in suitable forms for biochemical studies of their functions. Unexpectedly, we observed that full-length Sox4 appears to be protease-sensitive during expression and purification in E. coli. To map the protease-sensitive site in Sox4, we generated various constructs with each of functional domains of Sox4 and purified as the GST-Sox4 fusion proteins using glutathione beads. We found that the specific cleavage site for the proteolytic enzyme, which exists in E. coli, is localized within the novel GRR of Sox4. Our study suggest that the GRR of Sox4 may a target for the cellular protease action and this cleavage in the GRR may be involved in regulating physiological function of Sox4. Additionally, our study may provide a useful method for investigating the proteolytic cleavage of the target molecule in E. coli.