Dependence of synchronized bursting activity on medium stirring and the perfusion rate in a cultured network of neurons

Heo, Ryoun,Kim, Hyun,Lee, Kyoung J. 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol. No.

<P>A cultured network of neurons coupled with a multi-electrode-array (MEA) recording system has been a useful platform for investigating various issues in neuroscience and engineering. The neural activity supported by the system can be sensitive to environmental fluctuations, for example, in the medium's nutrient composition, ph, and temperature, and to mechanical disturbances, yet this issue has not been the subject. Especially, a normal practice in maintaining neuronal cell cultures involves an intermittent sequence of medium exchanges, typically at a time interval of a few days, and one such sudden medium exchange is unavoidably accompanied by many unintended disturbances. Here, based on a quantitative time-series analysis of synchronized bursting events, we explicitly demonstrate that such a medium exchange can, indeed, bring a huge change in the existing neural activity. Subsequently, we develop a medium perfusion-stirring system and an ideal protocol that can be used in conjunction with a MEA recording system, providing long-term stability. Specifically, we systematically evaluate the effects of medium stirring and perfusion rates. Unexpectedly, even some vigorous mechanical agitations do not have any impacts on neural activity. On the other hand, too much replenishment (e.g., 1.8 ml/day for a 1.8-ml dish) of neurobasal medium results in an excitotoxicity.</P>

Dependence of Synchronized Bursting Activity on Medium Stirring and the Perfusion Rate in a Cultured Network of Neurons

Ryoun Heo,Hyun Kim,Kyoung J. Lee 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.68 No.9

A cultured network of neurons coupled with a multi-electrode-array (MEA) recording system has been a useful platform for investigating various issues in neuroscience and engineering. The neural activity supported by the system can be sensitive to environmental fluctuations, for example, in the medium’s nutrient composition, ph, and temperature, and to mechanical disturbances, yet this issue has not been the subject. Especially, a normal practice in maintaining neuronal cell cultures involves an intermittent sequence of medium exchanges, typically at a time interval of a few days, and one such sudden medium exchange is unavoidably accompanied by many unintended disturbances. Here, based on a quantitative time-series analysis of synchronized bursting events, we explicitly demonstrate that such a medium exchange can, indeed, bring a huge change in the existing neural activity. Subsequently, we develop a medium perfusion-stirring system and an ideal protocol that can be used in conjunction with a MEA recording system, providing long-term stability. Specifically, we systematically evaluate the effects of medium stirring and perfusion rates. Unexpectedly, even some vigorous mechanical agitations do not have any impacts on neural activity. On the other hand, too much replenishment (e.g., 1.8 ml/day for a 1.8-ml dish) of neurobasal medium results in an excitotoxicity.

Molecular Observations in DC303.8-14.2

Hye-Ryoun Heo,Jeong-Eun Lee 한국천문학회 2009 天文學會報 Vol.34 No.1

개성공단 개발사업의 성과와 함의

허련(Ryoun Heo) 대한지리학회 2011 대한지리학회지 Vol.46 No.4

개성공단은 북한에서 남한이 시행한 최초의 공단이다. 정치, 경제, 사회, 문화적으로 남한과 다른 환경속에서 개발사업자로서 공단개발구상과 후보지 선정, 토지 취득, 조성공사 시행, 기반시설 설치, 분양, 기업유치, 유지관리 등 일련의 사업프로세스를 추진하는 과정에서 겪은 실무적 경험과 개발사업 중심의 시사점을 공유함으로써 향후, 개성공단 2단계, 3단계 뿐만아니라, 제2의 개성공단과 같은 남북경협사업에 도움이 되고자 한다. The purpose of this study is addressing the process of developing industrial complex in North Korea, especially in Gaeseong. The Gaeseong Industrial Complex(GIC) is the first project which is completed in North Korea by South Korean company. LH, the main developer of the project successfully made the various procedures, master planning, land acquiring, developing, attracting investment, managing SOC, for making the industrial complex competitive using its own know-how and experiences in South Korea. The New development experience of LH in Gaeseong Industrial Complex case would indicate various implications to us for making another developing project in North Korea.

Development of virtual reality visualization model (VRVM) with relative spatiotemporality for visual contents in molecular toxicology education

김승현,Heo Ryoun,Chung Yeonji,Park Sunghyo,Kim Jung Min,Kwon Michelle P.,Park Gil-Hong,Kim Meyoung-Kon 대한독성 유전단백체 학회 2021 Molecular & cellular toxicology Vol.17 No.1

Background Visualizing educational contents makes learning more efficient and effective especially in the area such as molecular toxicology, which is time consuming and intellectually taxing to learn. Objective A design principle based on cognitive neuroscience was developed for spatiotemporality of information and optimized virtual reality (VR) for molecular toxicology. We modeled VR with the tricarboxylic acid (TCA) cycle, a major working mechanism of several toxic poisons such as fluoroacetate, malonate, arsenite, etc. to improve the effectiveness of education in molecular toxicology for better recall compared to traditional education methods. Results We devised an educational system and theoretical basis for virtual reality visualization model (VRVM), as integrated research in this area had been insufficient thus far. We found that VRVM has positive effects on learning and memory when teaching complex topics such as molecular toxicology in our previous study. Conclusions This study has three main components: (1) construction of VR hardware/software (HW/SW) system; (2) creation of VR space design guide; and (3) verification of VRVM spatiotemporality. Consequently, we developed VRVM for the TCA cycle of toxicological mechanism to improve the study habits of medical students in the context of molecular toxicology studies. To continuously expand this approach for future educational applications, up-to-date findings in areas such as cognitive neuroscience and psychology for studying molecular toxicology should be incorporated to strengthen concepts, logic, and physical models of visualization.

사물인터넷 기반 실버대상의 심박측정용 웨어러블 디바이스 개발

서희륜(Hee Ryoun Seo),박준호(Joon Ho Park),허성필(Sung-Phil Heo) 한국통신학회 2017 한국통신학회 학술대회논문집 Vol.2017 No.6

Gitelman 증후군 환자에서 면역조직화학법으로 확인한 원위세관 sodium-chloride cotransporter (NCCT)의 결손

장혜련 ( Hye Ryoun Jang ),허남주 ( Nam Ju Heo ),손민정 ( Min Jung Son ),이재욱 ( Jay Wook Lee ),이정환 ( Jeong Hwan Lee ),전은실 ( Un Sil Jeon ),신성준 ( Sung Jun Shin ),나기영 ( Ki Young Na ),주권욱 ( Kwon Wook Joo ),이정상 ( Jun 대한내과학회 2005 대한내과학회지 Vol.69 No.6

목적 : Gitelman 증후군은 저포타시움혈증, 대사성 알칼리증, 고레닌혈증, 고알도스테론혈증, 요 중 칼슘 배설의 저하 및 저마그네슘혈증을 특징으로 하는 유전성 질환이다. 이는 원위세관 sodium-chloride cotransporter (NCCT)의 유전자 돌연변이에 의하여 발생하는 것으로 알려져 있으나 사람의 신조직에서 NCCT 결손이 증명된 바는 없었다. 방법 : 저자들은 임상적으로 Gitelman 증후군이 의심되는 환자에서 이뇨제를 이용한 신청소율 검사와 유전자 검사를 시행하였고, 이를 통하여 감별진단한 Gitelman 증후군 환자의 신조직에서 인간 NCCT에 대한 토끼 다클론 항체를 이용한 면역조직화학법을 시행하였다. 신세포암으로 신적출술을 시행 받은 환자의 정상 신조직과 전해질 이상이 없었던 사구체신염 환자의 신조직을 각각 정상 대조군과 질환 대조군으로 하였다. 결과 : 대상 환자는 저포타시움혈증과 대사성 알칼리증, 저마그네슘혈증 및 요 중 칼슘 배설의 저하를 보였다. Bartter 증후군과 감별을 위하여 furosemide 및 hydrochlorothiazide를 이용한 신청소율 검사를 시행하였다. 수분 부하를 시행한 기저치(86.1%)에 비해서 furosemide를 투여한 후 distal fractional chloride reabsorption이 감소하였으나(9.7%) hydrochlorothiazide 투여 후에는 변화가 없었다(81.4%). 유전자 검사 결과 SLC12A3 유전자의 돌연변이(S967F)가 발견되었다. 신조직에서 면역조직화학법을 시행한 결과 정상 및 질환 대조군에서는 원위세관 세포의 내강 막 쪽에 NCCT가 뚜렷이 염색되었으나, Gitelman 증후군에서는 원위세관 세포의 NCCT에 대한 면역 반응성이 관찰되지 않았다. 반면에 Na/K-ATPase, Na-K-2Cl cotransporter, calbindin-D28K는 대조군과 대상 환자의 신조직에서 모두 관찰되었다. 결론 : 기능적 검사로 진단된 Gitelman 증후군 환자의 신조직에서 NCCT의 결함을 면역조직화학법으로 확인하였다. Background : Gitelman`s syndrome is an autosomal recessive renal tubular disorder characterized by hypokalemic metabolic alkalosis, hypomagnesemia, and hypocalciuria. It is known to be caused by a mutation of SLC12A3 gene coding the sodium-chloride cotransporter (NCCT) in the distal tubule. The defect of NCCT in human renal tissues has not been investigated, and we tested whether the defect of NCCT can be detected in renal tissue of a patient with Gitelman`s syndrome by using immunohistochemistry. Methods : In an adult patient with Gitelman`s syndrome, blood and urine samples were collected for measurement of biochemical parameters. Renal clearance study and gene analysis were performed. Immunohistochemistry was performed on the renal tissue of the patient using a rabbit polyclonal antibody directed against a synthetic peptide corresponding to a portion in the amino terminal tail for human NCCT. Normal human renal tissues from surgical nephrectomy due to renal cell carcinoma and renal biopsy tissues from patients with glomerulonephritis but without any electrolyte disturbance were used as controls. Results : The patient had hypokalemic metabolic alkalosis, hypocalciuria and hypomagnesemia. Renal clearance study revealed a decrease in distal fractional chloride reabsorption after the administration of furosemide. SLC12A3 gene mutation (S967F) was found by direct sequencing method. Immunohistochemistry showed the absence of NCCT staining in the renal tissue of the patient. On the other hand, the immunostaining of other transporters was all positive in renal tissues from both Gitelman`s syndrome patients and controls. Conclusions : We report the absence of intact NCCT in the renal tissue of a Gitelman`s syndrome patient.(Korean J Med 69:642-650, 2005)

증례 : 호흡기 ; 면역억제제 치료 중인 류마티스 관절염 환자에서 발생한 Streptococcus salivarius 및 Nocardia 폐렴 1예

정인아 ( In A Jeong ),허은영 ( Eun Young Heo ),이재석 ( Jae Seok Lee ),김혜련 ( Hye Ryoun Kim ),이은영 ( Eun Young Lee ),김영환 ( Young Whan Kim ),양석철 ( Seok Chul Yang ) 대한내과학회 2009 대한내과학회지 Vol.77 No.1

Streptococcus salivarius는 상재균으로 감염의 원인으로는 간과되는 경우가 많았으나 최근 이 균에 의한 심각한 감염이 일부 환자에서 드물게 보고되어 왔다. Nocardia 감염 또한 드문 기회감염으로 스테로이드 치료, 악성종양, 장기 및 동종골수이식, 후천성면역결핍증 등 면역억제 환자에서 위험이 높은 질환이다. 본 증례에서는 스테로이드와 methtraxate, leflunomide를 투여 중인 류마티스 관절염 환자에서 발생한 다발성 종괴양 폐침윤에 대해서 기관지폐포세척액과 경기관지폐생검, 경피적미세침흡인 폐생검 조직의 배양검사를 통하여 Streptococcus salivarius 폐렴과 동반된 폐 Nocardia 감염을 진단하였으며, 항생제 치료로 증상과 방사선 소견이 모두 호전되어 이를 문헌고찰과 함께 보고한다. Streptococcus salivarius is a Gram-positive organism that belongs to the viridians group of streptococci. It is a relatively non-virulent bacterium that is part of the normal flora. It is rarely isolated from blood and is usually considered a contaminant. Nevertheless, S. salivarius may cause life-threatening infections, especially in immunocompromised hosts. There have been relatively few reports of S. salivarius pneumonia. Nocardiosis is also a rare opportunistic infection. Pulmonary nocardiosis is difficult to diagnose and, consequently, the diagnosis is often delayed. We report an unusual presentation with multiple pulmonary mass-like consolidations caused by a mixed infection of S. salivarius and Nocardia sp. in a 58-year-old man with rheumatoid arthritis who was taking oral corticosteroid, methotrexate, and leflunomide. The patient`s symptoms and radiographic findings improved after six weeks of antibiotic therapy. (Korean J Med 77:128-132, 2009)

서울시 오피스 임대료 결정요인 분석

노영학(Young Hak Noh),허련(Ryoun Heo) 한국전자통신학회 2009 한국전자통신학회 학회지 Vol.3 No.1

본 연구는 서울시를 중심으로 오피스의 주 수입원인 임대료에 대한 결정요인을 분석하여 어떤 요인에 의하여 임대료가 결정되어 지는가를 다중회귀모형을 이용하여 분석하고자 하였다. 그 결과 서울지역 오피스 임대료를 결정하는 요인은 연면적이 넓을수록, 전용율과 지상층수는 높을수록, 승강기는 많을수록, 관리방식은 전문 관리를 선택할 수록 임대료에 (+)영향을 미치고, 환산율과 공실률은 높을수록 (-)영향을 미치고 있다는 것을 확인할 수 있었다. By analyzing the factors of rent fee determination from economic perspective, I tried to find out how to improve the rate of return, which will lead to the rise of property valuein the end. To summarize the contents, the main factors affecting positive effects on rent fee of office building in Seoul are : bigger size higher building efficiency ratio, higher floor, more numbers of elevators , professional management system. On the other hand, as the deposit basis leasing exchange rate and vacancy rate are higher, the fee of office rent will go down. As office building market is gaining greater visibility and interest as the potential investment market from investors, researching on the factors that contribute to gain higher profit will be utilized for investors when they determine the investmenton the office building.

예비고령자의 유비쿼터스 주거시설 선호도 분석

노영학(Young hak Noh),허련(Heo Ryoun) 한국전자통신학회 2011 한국전자통신학회 학회지 Vol.5 No.1

예비고령층은 자녀와 가까운 도시의 독립된 공간에서 경제적 주도권을 가지고 고령자를 위한 전용주택에서 신변상의 안전과 건강을 위해 계획된 유비쿼터스 주거환경 안에서 활동적이고 적극적인 고령인 공동교류 공간을 선호하고 있으며, 고령친화주택과 융합된 다양한 라이프스타일의 유비쿼터스 주택유형의 주거공간개발이 필요하다. This study is Preliminary older the child, and near the city's independent space and economic leadership has for the elderly-only housing on the personal safety and health for the planned ubiquitous housing environment in the active and aggressive goryeongin common exchange space preferences, and elderly-friendly housing and Fused a variety of lifestyle ubiquitous housing type is necessary to develop the residential space.