흰쥐의 감각신경절세포에 대한 Methylmercuric chloride의 독성효과

鄭榮吉,白承和,韓斗錫,柳道坤,朴承澤 한국전통의학연구소 1998 한국전통의학지 Vol.8 No.1

흰쥐의 배양 척수감각신경절세포에 대한 methylmercuric chloride(MMC)의 세포독성을 조사하기 위하여 여러 농도의 MMC가 포함된 배앙액에서 24시간 동안 배양한 후 MTI assay법에 의하여 세포의 생존율을 조사하였다. MMC는 농도에 비례하여 세포의 생존율을 감소시켰다. 또한 여러 농도의 MMC가 포함된 배앙액에서 흰쥐의 척수 감각신경절(dorsal root ganglion, DRG) 세포를 24시간 동안 처리한 결과 MTI_(50) 값이 25μM MMC에서 나타났다. MMC는 Borenfreund등(1988)의 독성판정기준에 의하여 흰쥐의 배앙 DRG 세포에 고독성인 것으로 나타났다. 이상의 결과는 MMC가 흰쥐의 배양 척수감각신경절세포에 강한 신경독성 효과가 있음을 제시하였으며 또한 배양신경세포는 약제의 효과를 검색하는데 효과적이었다. To examine the cytotoxic effect of methyl mercuric chloride(MMC) on the cultured rat spinal dorsal root ganglion(ORG) neurons, cell viability was measured by MTT assay after rat spinal ORG neurons were incubated with media containing various concentrations of MMC for 24 hours The results were as follows ; 1. MMC decresed cell viability of rat spinal ORG neurons in a dose-dependent manner. 2. MIT_(950) value was a 25uM MMC after spinal ORG neurons were cultured for 24 hours at various concentrations of MMC. 3. MMC was heighly toxic on the cultured ORG neurons by the toxic criteria of Borenfreund et al.(1988). From above the results, it is suggested that methylmercury involves in neurotoxicity by the decrease of cell viability in cultured rat spinal DRG neurons, and cultured neurons are effective in screening the putative agents.

Study on Erosion Rate of CFRP

Gil-do Jeong(정길도),Mynul(마이눌),Amkee Kim(김엄기) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.11

The solid particle erosion behaviour of unidirectional carbon fiber reinforced plastic (CFRP) composites was investigated. The erosive wear of these composites was evaluated at different impact angles (30°,45°,60°,90°), different impact velocities (40, 55, 60,70㎧) and at three different fiber orientations (0°,45°,90°). The erodent used was silica sand with the size range 50-100㎛ of irregular shapes. The result showed ductile erosion behaviour with maximum erosion rate at 30° impingement angle. The Fiber orientations had a significant influence on erosion. The erosion rate displayed a strong dependence on impact velocity which followed the power law E∝V<SUP>n</SUP> for all materials. Based on three factors impact velocity(V), impact angle(α) and fiber orientation angle(β) a general method was proposed to predict the erosion rate of unidirectional fiber reinforced composites.

Immunohistochemistry on Dopaminergic Neuron Groups A9 and A10 in the Common Marmoset (Callithrix jacchus) Midbrain

Young-Gil Jeong,Nam-Seob Lee,Manbok Kim,Seon-Gil Do,Jun-Gyo Suh,Byung-Hwa Hyun,Moo Ho Won,Yang-Seok Oh 한국실험동물학회 2000 Laboratory Animal Research Vol.16 No.3

계절별 강수 패턴에 따른 하천 식생 변화 양상 연구

정희정 ( Hee-jeong Jeong ),유승연 ( Seung-yeon Yu ),조은지 ( Eun-ji Cho ),지용주 ( Yong-joo Ji ),김용석 ( Yong-suk Kim ),오현경 ( Hyun-kyung Oh ),이종성 ( Jong-sung Lee ),장현도 ( Hyun-do Jang ),조동길 ( Dong-gil Cho ) 한국지리정보학회 2023 한국지리정보학회지 Vol.26 No.2

국내에서는 모래와 자갈로 구성된 하천에서 식생이 과도하게 번성하는 현상이 전국적인 문제로 대두되고 있으며 그 요인을 봄철 강수량 감소와 연강수량 , 증가로 지적하고 있다. 본 연구는 경주시 소재 남천을 대상으로 강수 패턴 변화가 하천 식생에 미치는 영향을 파악하고 출현 식생의 면적변화, 그리고 생태적 특성 분석을 목적으로 수행되었다. 연구 결과, 남천의 여름철 월강수량은 2007년 이후로 감소하는 양상을 보였으며 사주면적 대비 식생면적은 지속적으로 증가하였다. 범람이 발생하지 않는 수준의 강수가 지속될 때 귀화식물 비율은 꾸준히 증가했으나, 귀화식물이 차지하는 면적은 적었다. 또한 일정 수위가 유지될 때, 단일종의 우점으로 인해 종다양성이 낮았으며 우점하는 종은 주로 자생식물이었다. 자생식물의 우점은 귀화식물의 생육을 억제하였으나, 식생면적은 더 크게 증가하였다. 따라서 하천식생의 활착과 번성을 해소하기 위해서는 자생식물과 귀화식물의 구분보다 식생확산 자체에 대한 관리가 필요하다. 여름철 집중 호우로 인한 고수위와 범람지속은 식물군락을 교란시켰고 이후 형성된 식생은 주로 자생식물이었다. 하천생태계에서 이와 같은 범람은 자생식물의 출현과 과도하게 형성된 식생군락에 긍정적인 요소로 작용하므로 식생 관리계획 수립 시 고려해야 할 것이다. In Korea, excessive vegetation in rivers made up of sand and gravel is emerging as a nationwide problem, which is attributed to increased spring precipitation and decreased annual precipitation. Therefore, this study was conducted for the purpose of identifying the effect of changes in precipitation patterns on river vegetation in Namcheon, Gyeongju, and analyzing the area of vegetation and ecological characteristics. As a result of the study, the amount of monthly precipitation in the summer of Namcheon decreased after 2007, and the area of vegetation increased continuously compared to the area of the sandbank. The proportion of naturalized plants increased steadily when precipitation continued to a level that did not cause flooding, but the area occupied by naturalized plants was small. Also, when the water level is maintained, the species diversity is low due to the dominance of a single species, and the dominant species was mainly native plants. Dominance of native plants inhibited the growth of naturalized plants, but the vegetation area increased even more. Therefore, it is necessary to manage the spread of vegetation itself rather than the division of native plants and naturalized plants in order to eliminate the active growth and prosperity of river vegetation. High water levels and continuous flooding caused by torrential rains in summer disturbed the plant communities, and vegetation formed afterwards was mainly native plants. Such flooding in river ecosystems is a positive factor for the emergence of native plants and over-formed vegetation communities, so it should be considered when establishing a vegetation management plan.

농업용 저수지와 논 경작을 고려한 HSPF-MASA-CREAMS-PADDY 연계 시스템 개발

이도길 ( Lee Do Gil ),송정헌 ( Song Jung-hun ),류정훈 ( Ryu Jeong Hoon ),이재남 ( Lee Jaenam ),최순군 ( Choi Soon-kun ),강문성 ( Kang Moon Seong ) 한국농공학회 2018 한국농공학회논문집 Vol.60 No.6

The objectives of this study were to develop a system linking hydrologic and water quality models considering the mechanisms of agricultural reservoir and paddy cultivation and to evaluate whether the developed system simulates hydrologic and water quality processes better than a hydrologic model that do not consider the mechanisms. The system consisted of Hydrological Simulation Program-Fortran (HSPF) as a watershed model, Module-based hydrologic Analysis System for Agricultural watersheds (MASA) as reservoir water balance model, and Chemical, Runoff and Erosion from Agricultural Management System-Paddy (CREAMS-PADDY) as a hydrologic and water quality model for paddy fields. This study carried out on the Seolseong-Cheon watershed in Icheon, and the water level and water quality had been monitored for two years at the outlet of the watershed. According to the results of this study, the performance of the simulation using HSPF-MASA-CREAMS-PADDY system was better than others, but they did not show a statistically significant difference. This seemed to be due to the uncertainty of the farming data and the water quality data of the reservoir. Therefore, if accurate input data for the system is obtained, HSPF-MASA-CREAMS-PADDY system could be used to model an agricultural watershed to obtain more realistic results. The results of this study could be utilized to the modeling of agricultural watersheds in Korea where paddy rice cultivation is dominant.

Rhus verniciflua Stokes attenuates cholestatic liver cirrhosis-induced interstitial fibrosis via Smad3 down-regulation and Smad7 up-regulation

Mi Na Gil,Du Ri Choi,Kwang Sik Yu,Ji Heun Jeong,Dong Ho Bak,Do Kyung Kim,Nam Seob Lee,Je Hun Lee,Young Gil Jeong,Chun Soo Na,Dae Seung Na,Ki Hyun Ryu,Seung Yun Han 대한해부학회 2016 Anatomy & Cell Biology Vol.49 No.3

Cholestatic liver cirrhosis (CLC) eventually proceeds to end-stage liver failure by mediating overwhelming deposition of collagen, which is produced by activated interstitial myofibroblasts. Although the beneficial effects of Rhus verniciflua Stokes (RVS) on various diseases are well-known, its therapeutic effect and possible underlying mechanism on interstitial fibrosis associated with CLC are not elucidated. This study was designed to assess the protective effects of RVS and its possible underlying mechanisms in rat models of CLC established by bile duct ligation (BDL). We demonstrated that BDL markedly elevated the serological parameters such as aspartate aminotransferase, alanine transaminase, total bilirubin, and direct bilirubin, all of which were significantly attenuated by the daily uptake of RVS (2 mg/kg/day) for 28 days (14 days before and after operation) via intragastric route. We observed that BDL drastically induced the deterioration of liver histoarchitecture and excessive deposition of extracellular matrix (ECM), both of which were significantly attenuated by RVS. In addition, we revealed that RVS inhibited BDL-induced proliferation and activation of interstitial myofibroblasts, a highly suggestive cell type for ECM production, as shown by immunohistochemical and semi-quantitative detection of a-smooth muscle actin and vimentin. Finally, we demonstrated that the anti-fibrotic effect of RVS was associated with the inactivation of Smad3, the key downstream target of a major fibrogenic cytokine, i.e., transforming growth factor b (TGF-b). Simultaneously, we also found that RVS reciprocally increased the expression of Smad7, a negative regulatory protein of the TGF-b/Smad3 pathway. Taken together, these results suggested that RVS has a therapeutic effect on CLC, and these effects are, at least partly, due to the inhibition of liver fibrosis by the downregulation of Smad3 and upregulation of Smad7.

Topical film prepared with <i>Rhus verniciflua</i> extract‐loaded pullulan hydrogel for atopic dermatitis treatment

Jeong, Ji Heun,Back, Seung Keun,An, Jong Hun,Lee, Nam‐,Seob,Kim, Do‐,Kyung,Na, Chun Soo,Jeong, Young‐,Gil,Han, Seung Yun John Wiley Sons, Inc. 2019 JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B Vol.107 No.7

<P><B>Abstract</B></P><P>Atopic dermatitis (AD) is characterized by relapsing pruritus and skin dryness. Due to the pathogenic multiplicity and the adverse effects associated with the current therapeutics, development of transdermal drug delivery system is becoming an area of interest. Here, a novel topical film prepared with <I>Rhus verniciflua</I> extract (RVE)‐loaded pullulan hydrogel (RVE@PH) was synthesized and tested its therapeutic efficacy on the AD rats modeled by neonatal capsaicin injection method. The RVE@PH was characterized by a Fourier‐transform infrared spectroscopy and an <I>in vitro</I> release assay. Rat pups were randomly divided into two groups: vehicle‐treated (VEH; <I>n</I> = 5) and capsaicin‐treated (<I>n</I> = 15). The latter were given capsaicin subcutaneously at 24 h after birth for AD induction and further divided into three groups (<I>n</I> = 5 per each): not treated (CAP), pullulan hydrogel‐applied (PH), and RVE@PH‐applied (RVE‐PH). The pullulan hydrogel and RVE@PH were topically applied on shoulder lesions for 14 days (from 42 to 56 days after birth). Their phenotypes were compared based on the dermatitis score, epidermal thickness, mast cell infiltration, and serum myeloperoxidase (MPO) activities. The PH group showed significant attenuation in all the aforementioned values compared to the CAP group, suggesting that pullulan hydrogel itself has therapeutic activity against AD. Notably, the attenuations were more potent in the RVE‐PH group than the PH group, indicating that the therapeutic efficacy against AD is augmented by the presence of RVE, a loaded pharmaceutic. Collectively, these results indicate that RVE@PH inhibits AD through exerting the dual roles, that is, the pullulan hydrogel‐mediated physical and RVE‐mediated pharmaceutical actions. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2325–2334, 2019.</P>

Ceria Nanoparticles Synthesized With Aminocaproic Acid for the Treatment of Subarachnoid Hemorrhage

Jeong, Han-Gil,Cha, Bong Geun,Kang, Dong-Wan,Kim, Do Yeon,Ki, Seul Ki,Kim, Song I.,Han, Ju hee,Yang, Wookjin,Kim, Chi Kyung,Kim, Jaeyun,Lee, Seung-Hoon Ovid Technologies Wolters Kluwer -American Heart A 2018 Stroke Vol.49 No.12

Growth of AlN/GaN HEMT structure Using Indium-surfactant

Jeong-Gil Kim,Chul-Ho Won,Do-Kywn Kim,Young-Woo Jo,Jun-Hyeok Lee,Yong-Tae Kim,Sorin Cristoloveanu,Jung-Hee Lee 대한전자공학회 2015 Journal of semiconductor technology and science Vol.15 No.5

We have grown AlN/GaN heterostructure which is a promising candidate for mm-wave applications. For the growth of the high quality very thin AlN barrier, indium was introduced as a surfactant at the growth temperature varied from 750 to 1070 ℃, which results in improving electrical properties of two-dimensional electron gas (2DEG). The heterostructure with barrier thickness of 7 ㎚ grown at of 800 ℃ exhibited best Hall measurement results; such as sheet resistance of 215 Ω/□, electron mobility of 1430 ㎠/V·s, and two-dimensional electron gas (2DEG) density of 2.04 x 10<SUP>13</SUP> /㎠. The high electron mobility transistor (HEMT) was fabricated on the grown heterostructure. The device with gate length of 0.2 ㎛ exhibited excellent DC and RF performances; such as maximum drain current of 937 ㎃/㎜, maximum transconductance of 269 mS/㎜, current gain cut-off frequency of 40 ㎓, and maximum oscillation frequency of 80 ㎓.

폐유리를 골재로 사용한 불포화 폴리에스테르 모르타르의 강도와 내산성에 관한 연구

도정윤,최길섭,김완기,조영국,소양섭 대한건축학회 2000 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.20 No.1